Introduction to Pilates-Based work in rehabilitation

Origins of Pilates-based work in rehabilitation

 

As a child, German-born Joseph H. Pilates (fig1) suffered from a multitude of illnesses resulting in muscular weakness. Determined to overcome his frailties, he dedicated his life to becoming physically stronger. He studied yoga, martial arts, Zen Meditation, and Greek and Roman exercises. He worked with medical professionals, including physicians and his wife Clara, a nurse. His experiences led to the development of his unique method of physical and mental conditioning, which he brought to the United States in 1923. In the early 1930s and 1940s, popular dance instructors and choreographers, such as Martha Graham, George Balanchine, and Jerome Robbins, embraced Pilates’ exercise method. As elite performers, dancers often suffered from injuries resulting in a long recovery period and an inability for peak performance. Unique at the time, Pilates’ method allowed and encouraged movement early in the rehabilitation process, by providing needed assistance. It was found that reintroducing movement with nondestructive forces early in the rehabilitation process hastened the healing process. As a result, it was not long before the dance community at large adopted Pilates’ work.

More than 70 years later, Pilates’ techniques began to gain popularity in the rehabilitation setting. In the 1990s, many rehabilitation practitioners were using the method in multiple fields of rehabilitation, including general orthopaedic, geriatric, chronic pain, neurologic rehabilitation, and more. Within the rehabilitation setting, most Pilates exercises are performed on several types of apparatus (fig 2).

The apparatus work evolved from Pilates’ original mat work, which was difficult as a result of the relationship of gravity on the body (fig 3). On the apparatus, springs and gravity are used to assist an injured individual to be able to complete movements successfully, aiding in a safe recovery (fig 4). Ultimately, by altering the spring tension or increasing the challenge of gravity, an individual may be progressed toward achieving functional movement.

 

 

 

Today, despite an increased number of health care practitioners using the Pilates-based approach in rehabilitation, there is still a lack of supportive literature examining the phenomena associated with Pilates-based techniques within the field of rehabilitation.

This article discusses theoretic foundations of the results experienced by Pilates-based practitioners in the field of rehabilitation. Current scientific theories in motor learning and biomechanics are examined to explain the principles of this old method of movement reeducation.

Motor learning and trunk control associated with the Pilates-based environment

The Pilates-based environment is conductive to designing task-oriented interventions. Within this environment, a faulty movement can be broken down into components using springs and changing the bodies
orientation to gravity. By successfully evaluating a patient’s needs and accessing the desired movement outcome, be it jumping, sitting, reaching, rotating, or walking, one can easily design a similar movement but with the appropriate level of load to the limb or trunk to support it while it heals. Adapting environmental constraints, such as gravity and base of support, reduces the degrees of freedom that must be controlled by the nervous system (5). The manipulation of the environment can hasten the reeducation process. As the movements are successfully completed, the patient can be progressed by decreasing the assistance or changing the orientation to gravity until the desired outcome is achieved. Commonly, trunk control is a desired outcome for functional movement and requires successful integration of all its components to maintain a normal orientation to gravity.

Research has looked at the importance of trunk control, led by Richardson and Hodges in Australia (14, 16, 21). Their research focused on defining the activity of trunk musculature among healthy subjects and subjects experiencing chronic low back pain during upper extremity movement. The results support the importance of core stiffening of the trunk muscles in preparation for movement of the extremities. For the purpose of this article, the word core is synonymous with trunk. Core stiffening is not thought to restrict movement of the spine but instead to facilitate controlled movement. Such a phenomenon is at the root of Pilates-based work. It was Pilates’ belief that core control was the essence of controlling human movement (12). Richardson and Hodges (14, 16) also identified the transversus abdominus muscle as being a primary postural control muscle. It is hypothesized that the transversus abdominus is activated at a subconscious and submaximal
contraction, as part of the motor plan, to provide trunk stiffness during dynamic movement. This approach to core control supports the theory of movement advocated by Pilates evolved practitioners, more so than
traditional methods. Pilates-evolved is a term used to differentiate practitioners who are continuing to define and expand on Pilates’ work from the traditional Pilates practitioners.

The goal of achieving efficient movement and returning to functional movement and enhanced performance is the foundation of Pilates-evolved work. Pilates-evolved exercises are thought to facilitate such movement behavior by allowing the patient to be in a position that minimizes unwanted muscle activity, often responsible for inefficient movement patterns and early fatigue, which can lead to injury. When a desired movement is challenged by a decrease in proprioception, individuals often overrecruit muscles in an attempt to stabilize. Although it has not been proved, it remains plausible that overstabilization or faulty stabilization inhibits efficiency and often acts as a hindrance to efficient movement. For example, a patient may be able to demonstrate a 90-degree straight leg passively, but when asked to lay on his or her side, with a decreased base of support, the available range of motion on the hipdrastically decreases (fig 5). the base of support and balance are challenged, the degree of efficiency and range of a movement often suffer. The Pilates-evolved environment allows the therapist to decrease the proprioceptive challenge by increasing the base of support and providing adequate assistance and feedback for an optimal motor learning environment.



The movement sequence can then be progressed by decreasing the assistance and amount of support, ensuring that the quality of the movement does not suffer. A therapist could then continue the progression toward a more functional task and familiar orientation with gravity. Traditional motor learning theory would teach that a cognitive level of learning take place first with internal and external feedback. Once association takes place and the patient continues to practice, the new movement sequence may become automatic. It is this automatic execution of new movements that reduces the risk of reinjury and increases efficiency.
Another important factor for attaining automatic movement is neurologic feedback from the deep muscles of the trunk, or the multifidi. The multifidi muscles have six times the number of muscle spindles of any other muscle in the trunk (9-11). This great source of kinetic feedback plays a large role in trunk awareness. Richardson et al (14) showed that patients with chronic low back pain recruited their multifidi with different timing and magnitude of contraction compared with normal subjects. The healthy subjects showed symmetric recruitment bilaterally of the multifidi muscles, whereas the subjects experiencing low back pain showed asymmetry of the multifidi on the affected side. Another study using ultrasonography showed a discrepancy at segmental levels in multifidus girth, correlating to the site of the lumbar lesion (14). Theoretically, if the multifidi and other deep paraspinal muscles are inhibited secondary to pain and pain inhibition, one could hypothesize that the same process would inhibit the proprioceptive feedback mechanism of that muscle (i.e., muscle spindle fiber). The loss of proprioceptive feedback leads to a decrease in trunk awareness and control. Inhibition of core proprioception may be responsible for faulty compensatory patterns that can result in destructive forces that prolong the healing process. Working to overcome faulty compensatory movement patterns is a fundamental goal in the Pilates-evolved method. Treatment and intervention goals are to improve the proprioception of the trunk and to minimize the destructive forces as described by Porterfield and DeRosa (13) in their phase II of rehabilitation biomechanical counseling. Once the patient has shown successful movement without pain, the exercise is progressed by decreasing the assistance and challenging the base of support.

This process is consistent with Porterfield and DeRosa’s phase III dynamic stabilization (13). The ability to challenge proprioception through a movement phase in the Pilatesevolved environment is endless. The three variables-base of support, length of levers, and degree of assistance-can be manipulated independent of each other, providing greater variety in the precision of the therapist’s modification of selected movements. Polestar Education Another example of an optimal environment for motor learning is found in Polestar Education, a Pilatesevolved education company focusing on rehabilitation (1). Polestar Education has defined the process of motor reeducation to the spine by breaking it down into three phases.

Phase I: Assistive movement Assisting movement with the use of springs can allow for a decrease of unwanted muscle activity or guarding often associated with pain or weakness. Phase I, according to Polestar, can be broken down into three stages.
These three stages can exist simultaneously.

Disassociation

Disassociation entails isolating movement at the hip or shouldervgirdle, independent of pelvis or spine movement. This isolation can begin by creating an environment with avlarge base of support (i.e. in supinevand offering assistance into the desired movement of the extremity (fig 6).

Disassociation combined with stabilization provides a favorable environment for protecting further trauma to spine lesions. The large muscles that are often guilty of the unwanted splinting (i.e. quadratus lumborum, gluteus maximus, and superficial erector spinae) can be taught to lengthen eccentrically, allowing the hip to absorb and distribute efficiently potentially harmful flexion forces to the spine.

Stabilization

In the early phase, the interest is in recruitment of deep stabilizers (i.e. transversus abdominus, internal and external abdominal obliques, and multifidi muscles). The stabilizers consist largely of type I fibers and are thought to contract at a submaximal level, which is less than 30% to 40% of a maximal voluntary contraction.

This submaximal contraction happens simultaneously while disassociating the extremities or segments above or below the lesion. As the extremity disassociates from the trunk and the pelvis remains in neutral, the deep stabilizers work efficiently to maintain control (fig 7).

This efficient use of the deep stabilizers and the decreased guarding is consistent with Porterfield and DeRosa’s phase I of rehabilitation, to control pain and to encourage biomechanical counseling.

Mobilization

Mobilization is the restoration of mobility to affected joints and muscles. A therapist can contribute to the pathology if mobilization is too aggressive or premature. Conversely a lesion may be traumatized further if mobility is not restored. This is why the use of assistance is so crucial to restore the desired movement properly.

The Pilates-evolved environment allows the therapist to use appropriate feedback and assistance to facilitate successful movement. As the therapist restores mobility to a target joint and surrounding joints, the force can be distributed equally, minimizing destructive forces (fig 8).

Phase II: Dynamic Stabilization Dynamic stabilization involves challenging the newly acquired mobility or stability in a more functional and gravity dependent environment. This phase is a continuation of disassociation, stabilization, and mobilization is phase I. By decreasing the assistance and base of support or increasing the length of the levers, a movement or exercise difficulty increases. Once the desired movement is restored, the newly acquired movement can be challenged at a level appropriate for goals and expected outcomes. Elite movers often require greater challenges against gravity and resistance than a more sedentary patient (fig 9).

 Efficiency of movement is the goal. By incorporating breathing and movement principles early in phase I activities, the ability of the patient to recruit secondary stabilizers (i.e., erector spinae, external and internal abdominal obliques, latissimus dorsi, and deep pelvis musculature) improves.
The rectus abdominus should be trained for more ballistic movements because it is primarily a type II fiber muscle (fast twitch). The focus in this phase is still control.

Phase III: Functional Reeducation

Specificity training and functional reeducation are popular concepts in the field of rehabilitation. The Polestar approach divides functional reeducation into two stages: (1) foreign environment and (2) familiar environment.

Foreign environment

Task Specificity is a major focus of attention for those researching motor learning. Most research shows that neuromusculature reeducation has carryover only from task-specific movements. To teach a patient how to jump off one leg, practice should consist of jumping off of one leg. It has been experienced clinically, however, that putting a patient back in familiar environments too soon can lead to the patient seeking the path of least resistance, returning to old habits. To continue with the example, if the patient does not tolerate jumping against gravity, the patient can be placed supine and asked to jump with gravity eliminated (fig 10). In a foreign environment, the desired movement can be replicated with less proprioceptive challenges and destructive forces, while providing necessary verbal and tactile clues, facilitating the motor learning process and allowing the patient to perform the movement correctly.

Familiar environment

In the familiar environment stage, the patient is returned to the specific task in their day- to-day environment. The movement task learned within the foreign environment is progressed to a familiar environment with a normalorientation to gravity. The patient is then challenged and encouraged to build adequate endurance and efficiency of movement in the familiar environment. Tactile and verbal clues used in the foreign environment are repeated to help associate each correct movement with the desired task (fig 11).

The final goal is to become autonomous with the movement. In summary of motor learning applications to trunk control, this section has addressed motor learning principles and current research that helps support Pilates-evolved work as a viable mechanism of neuromuscular intervention for rehabilitation. Biological and Physiologic Principles Associated With the Pilates- Based Approach Pilates-evolved work identifies various biomechanical and physiologic properties that can help support the Pilates-evolved approach in rehabilitation.

Current research associated with connective and neurologic tissue and the muscoskeletal system is considered in this section. Anthropometry is also discussed as a contributing factor toward seeking efficient interventions.

Connective tissue

Connective tissues provide support, transmit forces, and maintain the integrity structurally. All connective tissue is made up of cells and extracellular matrix composed of fibers and ground substance. The elasticity of the connective tissue is based largely on the ratio of collagen fibers to elastic fibers found in the tissue (7, 19). A large portion of connective tissue is avascular or hypovascular. This lack if vasculature would imply that nutrients are received through changes in pressure gradients, osmosis, and chemical and electric concentration (7). The Pilates-based exercises provide a closed-chain environment that facilitates compressive and decompressive forces on the connective tissues.
It can be hypothesized, based on animal research, that the degeneration often experienced by immobilization or lack of compressive and decompressive sources can be as destructive to cartilage as overuse to the cartilage (6). Many connective tissue lesions, such as osteoarthritis, osteoporosis, degenerative disk disease, chronic system arthritis, fascial pain syndromes, and cartilage and ligamentous tears and repairs, can benefit from closedchain movement when the load is modified.

Nervous tissue

Malfunctions of the peripheral and central nervous system continue to be investigated as a source of orthopaedic pathologies (2). The nervous system can be temporarily compromised; become ischemic; and provoke symp-toms of pain, paresthesia, weakness, and decreased motor control (17).
Often these signs and symptoms take on the appearance of a traditional orthopaedic diagnosis but symptoms do not respond to traditional treatments, such as injections, transverse tissue massage, ice, and muscle stretching. Practitioners often experience success in decreasing symptoms through mobilization of the nervous system and its connective tissue. It might be hypothesized, as described by Butler (3), that the cases that fail the more traditional pathways (i.e., joint and soft tissue mobilization, static rest, bracing or stabilization exercises) would do well with movement, or better stated, mobilization of the nervous system and its connective tissues. Pilates-based exercise can serve sd s technique to mobilize the nervous system and its surrounding connective tissues, as described by the practitioner.

Skeletal muscle

Skeletal muscle can be influenced greatly by Pilates-evolved exercises. In contrast to traditional modes of muscle conditioning that seek maximal voluntary contractions, Pilatesevolved muscle conditioning focuses on recruitment of the most effective motor units. This form of recruitment allows for an emphasis to be placed on energy efficiency and quality of performance. Physiologically, most muscle recruitment during day-to-day activities occurs in postural muscles, which contain predominately type I fibers. By facilitating postural muscles in the right sequence, a therapist can assist a patient in improving the efficiency of static and dynamic posture and decreasing significantly the likelihood of self-induced destructive forces. Richardson et al (15) found that the traditional method of eliciting an isolated volitional contraction is not the most efficacious way to teach a patient movement or to facilitate postural changes. Pilates-evolved practitioners have experienced that movement performance and efficiency are facilitated best by using imagery and feedback mechanisms instead of eliciting maximal voluntary contractions or isolated muscle contractions for gross strength. The movement sequences on various Pilates apparatus allow the practitioner to modify the load to facilitate efficient movement accurately. This approach can be supported with other basic principles of biomechanics and muscle physiology, such as muscle-length-tension curve and velocity training. The variation of strength and mechanics of the joints and levers through an arc of motion can be explained by the muscle-lengthtension curve and movement velocity.

For example, the greatest assistance can be applied at the beginning and end of the arc, where the strength is least, and the least assistance can be applied through the middle of the arc, where the strength is greatest.

In the case of dynamic stabilization the greatest resistance is applied in the middle of the arc of movement, where available torque is greatest. This is also the range that is least vulnerable to insult. Changing the velocity can also vary the muscle physiologic responses, allowing custom tailoring of the movement sequence to mirror the desired functional task of the patient (8, 9).

Anthropometry

Anthropometry deals with the measure of size, mass, shape, and internal properties of the human body (4) In the Pilates-evolved environment, the equipment adapts to many human body variations. For example, the springs, ropes, and footbar of the clinical reformer can be adjusted such that similar properties of movement sequencing can be applied to a variety of body types. The adaptability of the clinical reformer allows the practitioner to consider variations of an individuals weight and height. A good example is an exercise referred to as the hamstring arcs on the clinical reformer (fig 4). The objective of the movement sequence is to teach the patient to disassociate movement at the hip, while maintaining the pelvis and lumbar spine quiet or neutral.

The foot straps, as an extension of the ropes, are attached to the feet. The springs are set so as to hold the legs effortlessly at approximately 45 degrees flexion. If the legs are long, the ropes can be lengthened to provide the same level of assistance as can be done for a person with much shorter limbs. If the limb is heavy because of muscle mass or fat, the springs can be increased to balance out the weight of the lower limbs can move with control through space without losing control of the pelvis and spine. The flexibility of this environment can take into account multiple anthropometric configurations.

Conclusion

In comprehending current motor learning theories, biomechanical principles, neuromusculoskeletal physiology, and anthropometry, the Pilates-evolved work can be perceived as a viable and effective method of movement reeducation. It is now necessary to subject this method to the rigors of research to investigate its validity as a cost-effective and efficient intervention for rehabilitation, postrehabilitation, and fitness. The use of Pilates-evolved methods in the various fields of rehabilitation, including neurologically involved, chronic pain, orthopaedic, performance based, and pediatric rehabilitation, merits investigation.

Autor:  Brent D. Anderson, PT, OCS and Aaron Spector, MSPT

References


1 Anderson B, Larkam E: Polestar Education, Approach to rehabilitation in the Pilates Environment. Miami, Polestar’s Rehab Course manual for Continuing Education, 1977

2 ButlerDS: Functional anatomy and physiology of the nervous system. In: Mobilization of the Nervous System. New York, Churchill Livingstone, 1991

3 ButlerDS: The clinical consequences of injury to the nervous system. In: Mobilization of the Nervous System. New York, Churchill Livingstone, 1991

4 Chaffin D: Anthropology in occupational biomechanics. In: Occupational Biomechanics. New York, John Wiley, 1990

5 Horak FB: Assumptions underlying motor control for neurologic rehabilitation: Contemporary management of motor control problems. Presented at II Step Conference APTA, Norman, OK, 1991

6 Jurvelin J, Kiviranta I, Tammi M, et al: Softening of canine articular cartilage after immobilization of the knee joint. Clin Orthrop 207:246-252, 1986

7 Nordin M, Frankel VH: Biomechanics of tendons and ligaments. In: Basic Biomechanics of the Muscoskeletal System. Philadelphia, Lea & Febiger, 1989

8 Nordin M, Frankel VH: Biomechanics of skeletal muscle. In: Basic Biomechanics of the Muscoskeletal System. Philadelphia, Lea & Febiger, 1989

9 Norris CM: Spinal stabilisation limiting factors to end-range motion in the lumbar spine. Physiotherapy 81:64-72, 1995

10 Norris CM: Spinal stabilisation active lumbar stabilisation-concepts. Physiotherapy 81:61-64, 1995

11 Norris CM: Spinal stabilisation: Stabilisation mechanism of the lumbar spine. Physiotherapy 81:72-79, 1995

12 Pilates JH, Miller WJ: Result of contrology. In: Return to Life Through Contrology. New York, JJ Augustin, 1945

13 Porterfield JA, DeRosa C: Treatment of lumbopelvic disorders. In: Mechanical Low Back Pain: Perspectives in Functional Anatomy. Philadelphia, WB Saunders, 1991

14 Richardson C, Jull G, Hodges P, et al: Local muscle dysfunction in low back pain. In: Therapeutic Exercise for Spinal Segmental Stabilisation in Low Back Pain. London, Churchill Livingstone, 1999

15 Richardson C, Jull G, Hodges P, et al: Overview of the principles of clinical management of the deep muscle system for segmental stabilization. In: Therapeutic Exercise for Spinal Segmental Stabilisation in Low Back Pain. London, Churchill Livingstone, 1999

16 Richardson C, Jull G, Toppenberg R, et al: Techniques for active lumbar stabilisation fo spinal protection: A pilot study. Australian Physiotherapy 38:2, 1992

17 Sunderland S: The pathology of nerve injury. In: Nerve Injuries and Their Repairs. London, Churchill Livingstone, 1991

18 Van Wingerden BAM: Ligaments and capsule. In: Connective Tissue in Rehabilitation. Lichtenstein, Scipro Verlag-Valduz, 1995

19 Van Wingerden BAM: Muscle. In: Connective Tissue in Rehabilitation. Lichtenstein, Scipro Verlag- Valduz, 1995

20 Van Wingerden BAM: Principles of athletic training. In: Connective Tissue in Rehabilitation. Lichtenstein, Scipro Verlag- Valduz, 1995

21 Wolhfahrt D, Jull G, Richardson C: The relationship between the dynamic and static function of abdominal muscles. Australian Physiotherapy 39:1,1993

Tipos de fixação de Ligamentoplastias LCA / Graft Selection in ACL reconstruction

Graft Selection in ACL reconstruction



History

The type of graft that the surgeon chooses for ACL reconstruction has evolved over the past few decades. In the 1970s, Erickson popularized the patellar tendon graft autograft that Jones had originally described in 1960. This became the most popular graft choice for the next three decades. In fact, in a survey of American Academy of Orthopaedic Surgeon members done in 2000, 80% still favored the use of the patellar tendon graft.

In the light of harvest site morbidity and postoperative stiffness associated with the patellar tendon graft, many surgeons began to look at other choices, such as semitendinosus grafts, allografts, and synthetic grafts. Fowler and then Rosenberg popularized the use of the semitendinosus. However, even Fowler was not convinced of the strength of the graft. Then, Kennedy and Fowler developed the ligament augmentation device (LAD) to supplement the semitendinosus graft. Gore-Tex (Flagstaff,AZ), Leeds-Keio, and Dacron (Stryker, Kalamazoo, MI) were choices for an alternative synthetic graft to try to avoid the morbidity of the patellar tendon graft. The initial experience was usually satisfactory, but the results gradually deteriorated with longer follow-up.

Allograft was another choice that avoided the problem of harvest site morbidity. The initial allograft that was sterilized with ethylene oxide had very poor results. Today the freeze-dried, fresh-frozen, and cryopreserved are the most popular methods of preservation of allografts.

The allograft has become a popular alternative to the autograft because it reduces the harvest site morbidity and operative time. However, Noyes has reported a 33% failure with the use of allografts for revision ACL reconstruction.

The aggressive postoperative rehabilitation program advocated by Shelbourne in the 1990s greatly diminished the problems associated with the patellar tendon graft. Before that, the patient had to be an athlete just to survive the operation and rehabilitation program. Theaggressive program emphasized no immobilization, early weight bearing, and extension exercises.

There was renewed interest in the semitendinosus during the mid-1990s. Biomechanical testing on the multiple-bundle semitendinosus and gracilis grafts demonstrated them to be stronger and stiffer than other options. This knowledge combined with improved fixation devices such as the Endo-button gave surgeons more confidence with no-bone, soft tissue grafts. The Endo-button made the procedure endoscopic, thereby eliminating the need for the second incision. Fulkerson, Staubli, and others popularized the use of the quadriceps tendon graft. This again reduced the harvest morbidity, especially when only the tendon portion was harvested.

Shelbourne has described the use of the patellar tendon autograft from the opposite knee. He claims that this divides the rehabilitation between two knees and reduces the recovery time. With the contralateral harvest technique, the average return to sports for his patients was four months. With both the patellar tendon and the semitendinosus added to the list of graft choices, the need for the use of an allograft is minimized.

The latest evolution is to use an interference fit screw to fixate the graft at the tunnel entrance. This produces a graft construct that is strong, short, and stiff. It means that the surgeon now has to learn just one technique for drilling the tunnels and can chose whatever graft he or she wishes: hamstring, patellar tendon, quadriceps tendon, or allograft.

Successful ACL reconstruction depends on a number of factors, including patient selection, surgical technique, postoperative rehabilitation, and associated secondary restraint ligamentous instability. Errors in graft selection, tunnel placement, tensioning, or fixation methods may also lead to graft failure. Comparative studies in the literature show that the outcome is almost the same regardless of the graft choice. The only significant fact from the metaanalysis, as confirmed by Yunes, is that the patellar tendon group had an 18% higher rate of return to sports at the same level. The most important aspect of the operation is to place the tunnels in the correct position. The choice of graft is really incidental. Studies by Aligetti, Marder, and O’Neill show that the only significant differences among the grafts is that the patellar tendon graft has more postoperative kneeling pain.

Evolution in Graft Choice at Carleton Sports


Medicine Clinic

The most popular graft in the early 1990s was the patellar tendon graft

(Fig. 1). With the evolution of the 4-bundle graft and improved fixation in the mid-1990s, the hamstring graft became more popular. The swing to hamstring grafts then became largely patient driven.When the patients went to therapy after the initial ACL injury, they saw how easy the rehabilitation was for the hamstring tendon and opted for that graft.

The main choices of graft for ACL reconstruction are the patellar tendon autograft, the semitendinosus autograft, and the central quadriceps tendon, allograft of patellar tendon, Achilles tendon, or tibialis anterior tendon, and the synthetic graft.

Figure 1. The evolution of the graft choice. The white bar is the hamstring graft.


Patellar Tendon Graft

The patellar tendon graft was originally described as the gold-standard graft. It is still the most widely used ACL replacement graft (i.e., it is used in approximately 80% of cases), but it is not without problems. Shelbourne has pushed the envelope further with the patellar tendon graft. He has recently reported on the harvest of the patellar tendon graft from the opposite knee, with an average return to play of four months postoperative.

The advantages of the patellar tendon graft are early bone-to-bone healing at six weeks, consistent size and shape of the graft, and ease of Patellar Tendon Graft harvest. The disadvantages are the harvest site morbidity of patellar tendonitis, anterior knee pain, patellofemoral joint tightness with late chondromalacia, late patella fracture, late patellar tendon rupture, loss of range of motion, and injury to the infrapatellar branch of the saphenous nerve. Most of the complications are the result of the harvest of the patellar tendon.This is still the main drawback to the use of the graft.

Patellar Tendon Graft Indications

The ideal patient for an ACL reconstruction is the young, elite, competitive, pivotal athlete. This is the young athlete who wants to return to sports quickly and is going to be more aggressive in contact sports for a longer period of time. There is no upper age limit for patellar tendon reconstruction, but the younger athlete has more time to commit to knee rehabilitation. If the patellar tendon is the gold standard of grafts, then this is the graft of choice for the professional, or elite, athlete. Finally, the competitive athlete understands the value of the rehabilitation program and will not hesitate to spend three hours a day in the gym. The author’s assessment is that 50% of the success is the operation, and 50% is the rehabilitation program.

Pivoting Activities

The ACL is only required for pivotal athletics. Most nonpivotal athletes can usually cope without an ACL. Cyclists, runners, swimmers, canoeists, and kayakers, for example, can function well in their chosen sport without an intact ACL.

Athletic Lifestyle

This operation should be reserved for the athletic individual. In most activities of daily living the ACL is not essential. If the nonathlete has giving way symptoms, it is probably the result of a torn meniscus and not a torn ACL.The meniscal pathology can be treated arthroscopically, and the patient can continue with the use of a brace as necessary.

Patellar Autograft Disadvantages

Harvest Site Morbidity

The main disadvantage of the patellar tendon graft is the harvest site morbidity. The problems produced by the harvest are patellar tendonitis, quadriceps weakness, persistent tendon defect, patellar fracture, patellar tendon rupture, patellofemoral pain syndrome, patellar entrap-ment, and arthrofibrosis. The common long-term problem is kneeling pain.

Kneeling Pain

The most common complaint after patellar tendon harvest is kneeling pain. This can be reduced by harvesting through two transverse incisions. This reduces the injury to the infrapatellar branch of the saphenous nerve.

Patellar Tendonitis

Pain at the harvest site will interfere with the rehabilitation program. The strength program may have to be delayed until this settles. The problem is usually resolved in the first year, but it can prevent some high performance athletes from resuming their sport in that first year.

Quadriceps Weakness

The quads weakness may be the result of pain and the inability to participate in a strength program. If significant patellofemoral symptoms develop, the athlete may be unable to exercise the quads.

Persistent Tendon Defect

If the defect is not closed, there may be a persistent defect in the patellar tendon. This results in a weaker tendon.

Patella Entrapment

If the defect is closed too tight, the patella may be entrapped, and patellar infera may result. This will certainly result in patellofemoral pain, because of an increase in patellofemoral joint compression.

Patella Fracture

The fracture may occur during the operation or in the early postoperative period. Intraoperative patella fracture may be the result of the use of osteotomes. If the saw cuts are only 8-mm deep and 25-mm long, and the base is flat to avoid the deep V cut, an intraoperative fracture is rare. The late fractures are produced by the overruns of the saw cuts. The overruns may be prevented by cutting the proximal end in a boat shape.

The left X-ray shows a displaced transverse patellar fracture, at three months postoperative. The right X-ray shows the postoperative internal fixation with cannulated AO screws and figureof-eight wire.

 

Figure 2. X-ray of displaced transverse patellar fracture at three months postoperative.

Figure 3. X-ray of postoperative internal fixation with cannulated AO screws and figure-of-eight wire

Tendon Rupture

This may occur if a very large graft is taken from a small tendon. The standard is a 10-mm graft, measured with a double-bladed knife. The bone blocks are trimmed to 9 mm to make the graft passage easier.

Patellofemoral Pain

This topic is controversial in the literature. The older literature reported a high incidence of patellofemoral pain associated with ACL reconstruction. However, most of the disability could be blamed on rehabilitation programs that consisted of immobilization.There is no doubt that some patients will develop pain, some will develop crepitus, and some will have tendonitis, but results have improved with more aggressive rehabilitation programs with early motion and weight bearing. To prevent the patella from being bound down, the patella should be mobilized daily by the physiotherapist.

Arthrofibrosis

This severe problem is rarely seen now in ACL reconstructions.The true condition is idiopathic and is probably the result of fibroblastic proliferation. As a result, very little can be done to prevent it. It may be more common in the patient who forms keloid. The more common condition of loss of range of motion may be the result of incorrect tunnel placement or postoperative immobilization. In the mid-1980s, a limited range of motion hinge cast (preventing 30° of extension) was used for six weeks postoperatively, thereby causing problems in regaining extension. Many of these cases required arthroscopic debridement (10–18%, in the first year). The loss of extension was almost completely eliminated by changing to an extension splint. The acceptance of aggressive physiotherapy to regain extension eliminated the problem. This problem of postoperative stiffness made the use of a synthetic ligament, with no immobilization, very attractive. The reoperation for loss of range of motion is now very uncommon.
 
Tendon Rupture


This may occur if a very large graft is taken from a small tendon. The standard is a 10-mm graft, measured with a double-bladed knife. The bone blocks are trimmed to 9 mm to make the graft passage easier.

Patellofemoral Pain

This topic is controversial in the literature. The older literature reported a high incidence of patellofemoral pain associated with ACL reconstruction. However, most of the disability could be blamed on rehabilitation programs that consisted of immobilization.There is no doubt that some patients will develop pain, some will develop crepitus, and some will have tendonitis, but results have improved with more aggressive rehabilitation programs with early motion and weight bearing. To prevent the patella from being bound down, the patella should be mobilized daily by the physiotherapist.

Arthrofibrosis

This severe problem is rarely seen now in ACL reconstructions.The true condition is idiopathic and is probably the result of fibroblastic proliferation. As a result, very little can be done to prevent it. It may be more common in the patient who forms keloid. The more common condition of loss of range of motion may be the result of incorrect tunnel placement or postoperative immobilization. In the mid-1980s, a limited range of motion hinge cast (preventing 30° of extension) was used for six weeks postoperatively, thereby causing problems in regaining extension. Many of these cases required arthroscopic debridement (10–18%, in the first year). The loss of extension was almost completely eliminated by changing to an extension splint. The acceptance of aggressive physiotherapy to regain extension eliminated the problem. This problem of postoperative stiffness made the use of a synthetic ligament, with no immobilization, very attractive. The reoperation for loss of range of motion is now very uncommon..

Contraindications to Harvest of the Patellar Tendon

Preexisting Patellofemoral Pain

Is preexisting patellofemoral pain a contraindication to harvesting the patellar tendon? The conventional wisdom is yes; it would not be a wise procedure in this situation. Rather, it is like hitting a sore thumb with a hammer! In the past, when chondromalacia was seen at the time of arthroscopy, the graft choice would be changed to hamstrings.

The Small Patellar Tendon


The harvesting of the central third of the patellar tendon in a small tendon is more theoretical than practical. The advice in a small patient with a tendon width of only 25 mm would be to take a narrower graft of 8 to 9 mm or use another graft source.


Preexisting Osgoode-Schlatters Disease Shelbourne has reported that a bony ossicle from Osgoode-Schlatters disease is not a contraindication to harvest of the patellar tendon.

Because the fragment usually lies within the bony tunnel, this bone may be incorporated into the tendon graft.

Hamstring Grafts

Advantages of Hamstring Grafts

The main advantage of the hamstring graft is the low incidence of harvest site morbidity. After the harvest, the tendon has been shown by MRI to regenerate. The 4-bundle graft is usually 8mm in diameter, which is a larger cross-sectional area than the patellar tendon.

Disadvantages of Hamstring Grafts

The disadvantage of any autograft is the removal of a normal tissue to reconstruct the ACL. The harvest of the semitendinosus seems to leave the patient with minimal flexion weakness. One study did show some weakness of internal rotation of the tibia after hamstring harvest.

Injury to the saphenous nerve is rare and can be avoided with careful technique. The fixation of the graft remains one of the controversial issues.




Issues in Hamstring Grafts



The major issues with the use of hamstring grafts are:

Graft strength.

Graft fixation.

Graft healing.

Donor site morbidity.

Early rehabilitation.

Graft strength and stiffness.



In one of the earlier studies, Noyes reported that one strand of the semi-t was only 70% the strength of the ACL. However, hecompared this to a 15-mm-wide patellar tendon graft that was 125% the strength of the native ACL. This was widely quoted as a reason to use the patellar tendon graft rather than the hamstring.With the advent of the multiple bundles of hamstrings, this graft now has twice the strength of the native ACL (Fig. 7). Sepaga later reported that the semitendinosus and gracilis composite graft is equal to an 11-mm patellar tendon graft. Marder and Larson felt that if all the bundles are equally tensioned, the double-looped semi-t and gracilis is 250% the strength of the normal ACL. Hamner, however, emphasized that the strength is only additive if the bundles are equally tensioned.



Soft Tissue Fixation Techniques

There are various techniques for securing the soft tissue to the bony tunnel in ACL reconstruction. Each one has strengths and weaknesses. Pinczewski pioneered the use of the RCI interference fit metal screw for soft tissue fixation. The use of a similar type of bioabsorbable screw that was used in bone tendon bone fixation was a natural evolution. To overcome the weak fixation in poor quality bone, the use of a round pearl, made of PLLA or bone, was developed.This improved the pullout strength by 50%.The Endo-button, popularized by Tom Rosenberg, was improved with the use of a continuous polyester tape. This made the fixation stronger and avoided the problems of tying a secure knot in the tape. The cross-pin fixation has proven to be the strongest, but has a significant fiddle factor to loop the tendons around the post. The Arthrex technique is the easiest to use.Weiler, Caborn, and colleagues have summarized the current concepts of soft tissue fixation. The estimates of the force on the normal ACL during activities of daily living are as follows:



Level walking: 169N

Ascending stairs: 67N

Descending stairs: 445N

Ascending ramp: 27N

Descending ramp: 93N



It is commonly quoted that a person needs more than 445N pullout strength of the device just to handle the activities of daily living. However, Shelbourne has reported good results with the patellar tendon graft fixed by tying the leader sutures over periosteal buttons (Ethicon, J&J, Boston, MA). This form of fixation has a low failure strength, but is clinically successful. The gold standard of the interference fit screw fixation of the bone tendon bone, 350 to 750N, has been used to compare the soft tissue fixation.

The pullout strengths also vary from tibia to the femur. The femoral pullout is higher because the tunnel is angled to the graft and the pull is against the screw that is placed endoscopically. In the tibial tunnel, the graft pulls away from the screw in the direct line of the tunnel.

The initial fixation points were at a distance from the normal anatomical fixation of the ACL. The trend has been to move the fixation closer to the internal aperture of the tunnel. This shortening of the intraarticular length has improved the stiffness of the graft.

The pullout strength of bioabsorbable screw can vary widely depending on its composition. The screw fixation has also been shown to be bone quality dependent. These considerations should be taken into account when choosing a femoral fixation device for soft tissue grafts.

Disadvantages

The disadvantages of the hamstring graft are the various methods used to fix the graft to bone, including staples, Endo-button, and interference fit screws. Furthermore, the graft harvest can be difficult, the tendons can be cut off short, and there is a longer time for graft healing to bone, approximately 10 to 12 weeks.


Pullout Strengths of Soft Tissue Devices

The fixation of the graft depends on both the tibial and femoral fixation. The rehabilitation protocol should reflect the type of fixation used. All the femoral fixation devices provide reasonable fixation. The cyclic load is more important than the ultimate load to failure. The interference screw fares worst with cyclic loads.



Interference Fit Screws

The interference fit screw is shown is Figure 4.

Figure 4. The interference screw fixation of the soft tissue graft in a cadaver model

.

Advantages

The advantages are as follows:

Quick, familiar, and easy to use.
Direct bone to tendon healing, with Sharpey’s fibers at the tunnel aperture.
Less tunnel enlargement.

Disadvantages

The disadvantages are as follows:

Longer graft preparation time.
Bone quality dependent.
Damage to the graft with the screw.
Divergent screw has poor fixation.
Removal of metal screw makes revision difficult.

Several refinements have been made to the interference screw technique to increase the pullout strength and cyclic load performance. The end of the graft may be backed up with a round ball of PLLA, the Endo- Pearl (Linvatec, Largo, FL) or bone to abut against the screw and prevent the slippage of the graft under the screw. The tunnels may be dilated or compacted when the bone is osteopenic.A longer screw with a heavy whipstitch in the graft improves pullout strength. The leader sutures from the graft may be tied over a button or post on the tibial side to back up the screw fixation.




Cross-Pin Fixation

The cross-pin fixation is shown in Figure 5

Figure.5. The Arthrex transfix pin fixation of soft tissues.

Advantages

The advantages are as follows:

Strongest tested fixation.

May individually tension all bundles of graft.
 
Disadvantages


The disadvantages are as follows:

Pin may tilt in soft bone and lose fixation.

Steep learning curve of fiddle factor.

Special guides are required.



Buttons

Buttons are shown in Figure 6 and Figure 7.

Figure 6. The Endo-button periosteal cortical femoral fixation of hamstring grafts.



Figure 7 The periosteal button fixation of soft tissue grafts.

Advantages

The advantages are as follows:

The Endo-button with closed loop tape is strong, if expensive.
The plastic button is cheap, available and easy to do.
 
Disadvantages


The disadvantages are as follows:

Fixation site is distant with increase in laxity, with the bungee cord effect.

Increased in tunnel widening.

Plastic button has low pullout strength, dependent on the sutures.



Tibial Fixation

The tibial fixation remains a problem with soft tissue graft fixation. Patients generally do not tolerate metal devices in the subcutaneous area on the front of the tibia. The interference screw gets away from that problem, but has poor performance in cyclic load. The graft tends to slip out from under the screw as the knee is cycled. A backup fixation must be used it the interference screw is used. The Intrafix (Mitek) device uses the interference screw fixation principle, but increases both the ultimate load to failure and the cyclic load performance.

Considerations

The most important consideration in ACL reconstruction is that the tunnels are put in the correct position. After this, the fixation of the graft is the next most important factor in a satisfactory clinical outcome. The physician should become proficient at one of these techniques. For revi-sions, physicians may need to have available another type of fixation to deal with hardware and tunnel expansion.
 
Tendon-to-Bone Healing




Studies have shown that it takes at least 8 to 12 weeks for soft tissue to heal to bone, as compared to 6 weeks for bone-to-bone healing with the patellar tendon graft. Recent studies have shown that the compression of the tendon in the tunnel with a screw speeds the time of healing, similar to internal compression in bone healing.



Donor Site Morbidity

In 1982, Lipscomb found that after harvest of the semitendinosus only the strength of the hamstrings was 102% and after harvest of both the strength was 98%. Recently, it has been shown that the internal rotation strength is decreased after the harvest of the semitendinosus. The patellofemoral pain incidence has been reported by Aligetti to be 3 to 21% after semitendinosus reconstruction. There are rare reported cases of saphenous nerve injury.



Early Rehabilitation

Prospective randomized studies by Aligetti and Marder have shown that with early and aggressive rehabilitation, there was no difference between the semitendinosus and patellar tendon grafts in stability or final knee rating. This puts to rest the argument as to whether the hamstring graft can withstand early aggressive rehabilitation protocols.



Central Quadriceps Tendon

This graft has been largely ignored in North America over the past decade. An assistant can harvest the graft while the surgeon is doing the notchplasty. It is a large diameter graft, 10 ¥ 10mm (Fig. 5.12). The tendon graft is fixed with interference screws for the bone plug and sutures tied over buttons for the tendon end. A bioabsorbable interference screw may be used at the internal aperture of the tunnel to reduce the tendon motion in the tunnel. The quadriceps tendon graft should reduce the need for the allograft or synthetic in revision cases.
 

Figure. 8 The quadriceps tendon graft.

Allografts


Advantages

The allograft has no harvest site morbidity. With no harvest required, the time of the operative procedure is reduced.



Disadvantages



The main objection to the use of the allograft is the risk of disease transmission. Jackson has shown that it takes longer for the graft to incorporate and mature, meaning a longer time until the patient can return to sports. In addition, there is a limited availability of allograft materials. In the literature, Noyes has shown that in long-term follow-up, failure rates increase. In the 1997 survey of the ACL study group by Campell, none of the members used allografts for primary reconstructions.

Synthetic Grafts

The best scenario for the use of the LARS synthetic graft is when the graft can be buried in soft tissue, such as in extra-articular reconstruction. This allows for collagen ingrowth and ensures the long-term viability of the synthetic graft. It will be sure to fail early if it is laid into a joint bare, especially going around tunnel edges, and is unprotected by soft tissue.
Advantages


There is no harvest site morbidity with the use of the synthetic graft. The graft is strong from the time of initial implant. There is no risk of disease transmission.

Disadvantages

The main disadvantage is that all the long-term studies have shown high failure rate. There is the potential for reaction to the graft material with synovitis, as seen with the use of the Gore-Tex graft.With the Gore-Tex graft, there was also the increased risk of late hematogenous joint infection. The results that have been reported with the use of the Gore-Tex graft suggest that it should not be used for ACL reconstruction. Unacceptable failure rates have also been reported with the use of the Stryker Dacron ligament and the Leeds-Keio ligament. The ligament augmentation device was also found to be unnecessary.

 

Figure 9 The insertion of the BioScrew through the anteromedial portal

Figure 10. The insertion of the BioScrew into the femoral tunnel

WORK-RELATED BACK PAIN

Back pain, like tooth decay and the common cold, is an affliction that affects a substantial proportion, if not the entire population, at some point in their lives. Nobody is immune to this condition nor its potential disability which does not discriminate by gender, age, race or culture. It has become one of the leading causes of disability in our society and the cost of treatment has been increasing progressively each year, without any obvious effect on the frequency and severity of the condition. The search for a cure and the elimination of back pain does not appear to be a viable option at this point in our understanding of back pain. A reasonable goal, however, is to improve the ability of clinicians to determine the cause of back pain in a substantial proportion of patients, to identify conditions likely to lead to serious disability if not treated promptly, to reduce the symptoms of back pain, to increase functional capacity and to reduce the likelihood of recurrences.

EPIDEMIOLOGY

The prevalence of back pain in the adult population varies with age. There are a number of surveys in multiple countries that reveal a point-prevalence of 17–30%, a 1-month prevalence of 19–43% and a lifetime prevalence of 60–80%. The likelihood that an individual will recall on survey that they have experienced back pain in their lifetime reaches 80% by the age of 60 years, and there is some evidence that the remaining 20% have simply forgotten prior episodes of back pain or considered such episodes as a natural part of life and not worth reporting. At the age of 40 years, the prevalence is slightly higher in women, while, after the age of 50, it is slightly higher in men. The majority of these episodes of back pain are mild and short-lived and have very little impact on daily life. Recurrences are common and one survey found that up to 14% of the adult population had an episode of back pain each year that lasted 30 days or longer and at some point interfered with sleep, routine activities or work. Approximately 1% of the population is permanently disabled by back pain at any given point, with another 1–2% temporarily disabled from their normal occupation.

Children and adolescents are not immune from back pain. Surveys reveal that approximately 5% of all children have a history of back pain that interferes with activity, with 27% reporting back pain at some time.Normal spinal anatomy and physiology The spine is one of the most complex structures in the body. It is a structure that includes bones, muscles, ligaments, nerves and blood vessels as well as diarthrodial joints. In addition, the structures that make up the spine include the intervertebral discs, the nerve roots and dorsal root ganglia, the spinal cord and the dura mater with its spaces filled with cerebrospinal fluid. Each of these structures has unique responses to trauma, aging and activity.

WORK-RELATED BACK PAIN

Back injuries make up one-third of all work-related injuries or almost one million claims in the United States each year. Approximately 150 million workdays are lost each year, affecting 17% of all American workers. Half of the lost workdays are taken by 15% of this population, usually with prolonged periods of time loss, while the other 50% of lost work days are for periods of less than 1 week. The incidence rates for work-related back injuries vary, depending on the type of work performed. The factors that increase the likelihood of back injury are repetitive heavy lifting, prolonged bending and twisting, repetitive heavy pushing and pulling activities and long periods of vibration exposure. Work that requires minimal physically strenuous activity, such as the finance, insurance and service industries, has the lowest back injury rates, whereas work requiring repetitive and strenuous activity such as construction, mining and forestry has the highest injury rates.

PATHOLOGY AND BACK PAIN

There is a strong inclination on the part of clinicians and patients suffering from back pain, especially if it is associated with disability, to relate the symptoms of pain to pathological changes in spinal tissues. For this reason, there is a tendency to look for anatomical abnormalities to explain the presence of pain, by ordering X-rays, computerized tomography (CT) or magnetic resonance imaging (MRI) studies. It is tempting to point to changes in anatomical structure seen on these studies as the cause of the symptoms. Unfortunately, the assumption that the lesion seen on these studies is the cause of the pain is not always valid. Degenerative changes occur in virtually all patients as part of the normal aging process. At age 20, degenerative changes are noted on X-ray and MRI in less than 10% of the population. By age 40, such changes are seen in 50% of the asymptomatic population and, by age 60, this number reaches over 90%. Disc and joint pathology is noted in 100% of autopsies of persons over the age of 50. These changes can affect multiple levels of the spine and can be severe in the absence of symptoms. Pathology in the intervertebral disc can also exist in the absence of symptoms. Disc protrusion or herniation can be found in 30–50% of the population in the absence of symptoms. Even large and dramatic disc herniations and extrusions can be found in asymptomatic individuals. Changes in the intervertebral disc seen on discography, including fissures and radial tears, have recently been found to exist in patients without back pain. It is, therefore, not possible to interpret pathology seen on imaging studies as the origin of a person’s back pain without looking for other contributing factors or clinical findings.

PHYSIOLOGY OF BACK PAIN

There are a number of factors that have been implicated in the genesis of back pain and disability that can be used to determine whether a pathological process seen on imaging studies is associated with symptoms experienced by a patient. Certain of these factors are based on epidemiological studies, while others are based on clinical findings and physiological tests. Pain in any structure requires the release of inflammatory agents that stimulate pain receptors and generate a nociceptive response in the tissue. The spine is unique in that it has multiple structures that are innervated by pain fibers. Inflammation of the posterior joints of the spine, the intervertebral disc, the ligaments and muscles, meninges and nerve roots have all been associated with back pain. These tissues respond to injury by releasing a number of chemical agents that include bradykinin, prostaglandins and leukotrienes. These chemical agents activate nerve endings and generate nerve impulses that travel to the spinal cord. The nociceptive nerves, in turn, release neuropeptides, the most prominent of which is substance P. These neuropeptides act on blood vessels, causing extravasation, and stimulate mast cells to release histamine and dilate blood vessels. The mast cells also release leukotrienes and other inflammatory chemicals that attract polymorphonuclear leukocytes and monocytes.

These processes result in the classic findings of inflammation with tissue swelling, vascular congestion and further stimulation of painful nerve endings. The pain impulses generated from injured and inflamed spinal tissues are transmitted via nerve fibers that travel through the anterior (from nerves innervating the extremities) and posterior (from the dorsal musculature) primary divisions of the spinal nerves and through the posterior nerve roots and the dorsal root ganglia to the spinal cord, where they make connections with ascending fibers that transmit the pain sensation to the brain. The spinal cord and brain have developed a mechanism of modifying the pain impulses coming from spinal tissues. At the level of the spinal cord , the pain impulses converge on neurons that also receive input from other sensory receptors. This results in changes in the degree of pain sensation that is transmitted to the brain through a process commonly referred to as the ‘gate control’ system. The pain impulses are modified further through a complex process that occurs at multiple levels of the central nervous system. The brain releases chemical agents in response to pain known as endorphins. These function as natural analgesics. The brain can also block or enhance the pain response by means of descending serotonergic modulating pathways that impact with pain sensations both centrally and at the spinal cord level. The latter mechanism is felt to be responsible for the strong impact of psychosocial factors on the response to pain and the disability associated with back pain.

The pain centers in the spinal cord and brain can also change through a process known as plasticity which may explain the observation that many patients develop chronic pain that is more widespread than the pathological lesion and continues after the resolution of the peripheral inflammatory process.

APPROACHING THE PATIENT WITH BACK PAIN

The factors that determine the degree of back pain, and especially the amount of disability associated with the pain, are therefore the result of multiple factors. Structural pathology sets the stage and is the origin of the painful stimulus. The natural healing process, in most situations, results in the resolution of back pain within relatively short periods. Physical stress placed on the back through work and leisure activities may slow the healing process or irritate spinal pathology such as degenerative changes or disc protrusion. It is, however, the psychosocial situation of the patient that determines the level of discomfort and the response of a patient to the painful stimulus.

The patient’s psychological state, level of satisfaction with work and personal life as well as his/her social and spiritual life may impact upon the central modulation system in the brain and modify the response to pain. In this volume, a great deal of emphasis is placed on visualization of spinal lesions that can result in spinal pain. To rely on anatomical changes to determine the cause of back pain can, however, be very misleading to the clinician through the mechanisms described above. There are other examples in science that can be used as a model for looking at spinal pain. The Danish pioneer of quantum physics, Niels Bohr, claimed that science does not adequately explain the way the world is but rather only the way we, as observers, interact with this world. Early in the last century, it was discovered that light could be explained in terms of either waves or particles, depending on the type of experiment that was set up by the observer. Bohr postulated that it was the interaction between the scientist, as the observer, and the phenomenon being studied, in this case light, that was important. The same thing can be said forthe clinician approaching a patient with back pain.The conclusions reached by the clinician regarding the etiology of back pain in a specific case are often dependent on the interaction between the patient and the clinician and the training and experience brought to the decision-making process by both individuals.

There are other ways of looking at back pain. Chaos theory postulates that there is a delicate balance between disorder and order. The origin of the universe is generally explained by the ‘Big Bang’ theory which states that, in the beginning, there was total disorder which was followed by the gradual imposition of order through the creation of galaxies, stars and planets. This process is perceived as occurringthrough a delicate balance between the forces of gravity and the effects of the initial explosion. This process emphasizes that small changes at the beginning of a process or reaction can result in large changes over time. If one applies this analogy to the interaction between patients with back pain and their physicians, the outcome of treatment can be perceived as being impacted upon by a number of beneficial influences or ‘little nudges’ and harmful attitudes or ‘little ripples’ (Table 1). The patient’s symptoms can be positively impacted through such processes as listening, caring, laughter, explanation, encouragement, attention to detail and even prayer and negatively impacted by fear, anxiety, anger, uncertainty, boredom and haste. The manner in which a physician uses these nudges and helps the patient avoid the ripples can have a large effect on the impact of back pain on the patient’s life. The most accurate diagnosis possible is dependent on accurately observing and listening to the patient, the physical examination and the results of all testing in combination with the intuition that is gained from experience from treating multiple similar patients.

The fine balance between different factors impacting on back pain can be illustrated by a few simple examples.

Example 1

A 50-year-old woman presented to her doctor with symptoms and signs of a disc herniation confirmed by CT scan. She was the owner of a small cattle range and was worried about the condition of her animals. She underwent surgery to correct the disc herniation but her convalescence was prolonged for no apparent reason. After several months, the condition of her cattle herd improved and, at the same time, the patient’s symptoms improved. This raises the question as to the link between the patient’s symptoms, the disc herniation and the condition of her cattle.

Example 2

A 45-year-old gentleman in a position with a responsible insurance company presented to his doctor with symptoms and signs of severe L4–5 instability confirmed by stress X-rays. The patient underwent a posterolateral fusion. At 3 months, the fusion was solid but the patient’s symptoms did not improve. Further questioning revealed that he felt stressed and was unhappy in his work. At 6 months, he became symptom-free without further treatment. The only evident change in his status was the resolution of his difficulties at work.

Example 3

A 35-year-old gentleman with a wife and two small children was admitted to the hospital on an emergency basis with suspected cauda equina syndrome. A psychotherapist assigned to the case discovered that the patient found the presence of his mother-inlaw intolerable. Arrangements were made for the mother-in-law to live elsewhere and the patient made an uneventful recovery without the necessity of surgery.

Table 1 Beneficial influences (nudges) and harmful influences (ripples) which impact on the outcome of treament for back pain

Harmful influences                        Beneficial influences

Fear                                            Listening and caring
Anxiety                                       Laughter
Anger                                         Explanation
Uncertainty                                 Encouragement
Boredom                                    Attention
Haste                                         Prayer

 
THE BONY VERTEBRAE

Each of the bony elements of the back consist of a heavy kidney-shaped bony structure known as the vertebral body, a horseshoe-shaped vertebral arch made up of a lamina, pedicles and seven protruding processes. The pedicle attaches to the superior half of the vertebral body and extends backwards to the articular pillar. The articular pillar extends rostrally and caudally to form the superior and inferior facet joints. The transverse processes extend laterally from the posterior aspect of the articular pillar where it connects to a flat broad bony lamina. The laminae extend posteriorly from the left and right articular pillars and join to form the spinous process. Two adjacent vertebrae connect with each other by means of the facet joints on either side. This leaves a space between the bodies of the vertebrae which is filled with the intervertebral disc. The intervertebral foramen for the exiting nerve root is formed by the space between the adjacent pedicles, facet joints and the vertebral body and disc. The integrity of the nerve root canal is therefore dependent on the integrity of the facet joints, the articular pillars, the vertebral body endplates and the intervertebral disc. The bony vertebrae can be visualized on standard radiographs and on CT scan using X-radiation. The bones can also be visualized on MRI, although with not quite the same definition. The metabolism of the bony vertebra can be visualized by means of a technetium bone scan.

Figure 1.1 Superior view of an isolated lumbar vertebra

This view demonstrates the two posterior facets and the vertebral body endplate where the disc attaches. The facets and the disc make up the ‘three-joint complex’ of the spinal motion segment. The body of the vertebra is connected to the articular pillars by the pedicles. The superior and inferior articular facets extend from the articular pillars to connect with the corresponding facets of the vertebrae above and below, to make up the posterior facets. The lateral transverse processes and the posterior spinous process form the attachments for paraspinal ligaments and muscles.

THE INTERVERTEBRAL DISC
The intervertebral disc is made up of an outer annulus fibrosis and a central nucleus pulposus. It is attached to the vertebral bodies above and below the disc by the superior and inferior endplates. The nucleus pulposus  a gel-like substance made up of a meshwork of collagen fibrils suspended in a mucopolysaccharide base. It has a high water content in young individuals, which gradually diminishes with degenerative changes and wit the natural aging process. The annulus fibrosis is made up of a series of concentric fibrocartilaginous lamellae which run at an oblique angle of about 30º orientation to the plane of the disc. The fibers of adjacent lamella have similar arrangements, but run in opposite directions. The fibers of the outer annulus lamella attach to the vertebral body and mingle with the periosteal fibers. The fibrocartilaginous endplates are made up of hyaline cartilage and attach to the subchondral bone plate of the vertebral bodies. There are multiple small vascular perforations in the endplate,which allow nutrition to pass to the disc.
The intervertebral disc is not seen on standard Xray, but can be visualized by means of MRI scan and

CT scan. The integrity of the inner aspects of the disc is best visualized by injecting a radio-opaque agent into the disc. This material disperses within the nucleus and can be visualized radiologically as a discogram.

THE POSTERIOR FACETS

The facet joints connect the superior facet of a vertebra to the inferior facet of the adjacent vertebra on each side and are typical synovial joints. The articular surfaces are made of hyaline cartilage which is thicker in the center of the facet and thinner at the edges. A circumferential fibrous capsule, which is continuous with the ligamentum flavum ventrally, joins the two facet surfaces. Fibroadipose vascular tissue extends into the joint space from the capsule, particularly at the proximal and distal poles. This tissue has been referred to as a meniscoid which can become entrapped between the facets.
The posterior facets can be seen on X-ray but only to a limited extent. Degenerative changes and hypertrophy of the facets can be visualized to a greater extent on CT and MRI. Radio-opaque dye can also be injected into the joint and the distribution of the dye measured.

Figure 1.2 Lateral view of the L3 and L4 vertebrae

This projection demonstrates the manner in which the facets join. The space between the vertebral bodies is the location of the cartilaginous intervertebral disc. Courtesy Churchill-Livingstone (Saunders) Press

Figure 1.3 Transverse view of L2 showing normal intervertebral disc morphology

Figure 1.4 Longitudinal view of the lumbar spine showing normal disc size and morphology

Courtesy Churchill-Livingstone (Saunders) Press

Figure 1.5 Normal discogram