Rehabilitation of a Patient with Functional Instability Associated with Failed Back Surgery, The
Objective: A report of a case of a low-tech non-dynamometric functional exercise program in the rehabilitation of a functionally unstable lower back, associated with failed back surgery.
Clinical Features: A 41-year-old female presented to a chiropractic office with severe lower-back pain, with radiation down the left leg to the calf. Seven months prior, she had an L5-S1 discectomy. Two months after the surgery, her pain in the lower back and leg returned. An MRI 6 months after the surgery showed no evidence of a recurrent disc herniation, but revealed a small image enhancement along the, posterior annulus adjacent to the right S1 nerve root, consistent with post-operative change. Plain film radiography was unremarkable.
Intervention and Outcome: The home-based therapeutic techniques used in this case were based on the patient's weaknesses demonstrated on a functional evaluation. This evaluation consisted of 4 functional tests, including the repetitive squat, Sorenson static back endurance, repetitive sit-up, and the repetitive arch-up tests. The exercises were performed over a 6-week period, and resulted in a decrease in both pain and functional disability based on visual analog scale, pain diagrams, and the Oswestry low-back pain questionnaire.
Conclusion: A home-based exercise program proved very effective in decreasing this patient's functional disability level, but was ineffective in reducing pain levels. Further investigation of chiropractic management of such cases is warranted.
Key Words or Phrases: functional instability, rehabilitation, failed back surgery
Failed back surgery syndrome (FBSS) is a complex clinical problem that results from persistent pain following lumbar spinal surgery. The complexity of FBSS derives in part from the multidimensional nature of pain itself. FBSS is addressed with numerous therapies, including epidural corticosteroids, opioids, pedicle screws, spinal cord stimulation, exercise, and acupuncture. Outcomes for these therapies are not conclusive, and no standard treatment has been established.1
Accurate diagnosis is necessary for optimal treatment. An accurate diagnosis of FBSS can be established in more than 90% of cases-through a proper history, selected imaging studies, psychological evaluation, and, possibly, diagnostic injections. Other common problems in patients with FBSS may include foraminal stenosis, discogenic and neurogenic pain, facet and sacroiliac joint pain, residual or recurrent disc herniation, and psychological disorders.2 Medical imaging modalities, including magnetic resonance imaging, may be required to diagnose any clinically relevant abnormality and to determine if further surgical intervention is needed.3
An important factor in the genesis of FBSS can be clinical instability4-a significant decrease in the ability of the spine stabilization system to keep the intervertebral neutral zones within the physiological limits without neurological dysfunction, major deformity, or incapacitating pain. The neutral zone is a region of intervertebral range of motion around the neutral posture, where there is little resistance by the passive spinal column.5
Disc injury may alter overall spinal mechanics, including the behavior of the disc itself, as well as that of other spinal structures.6
According to McGill, "sufficient stability" is a complete concept and desirable objective that seeks the optimal balance between stability and mobility.7 The best stabilizer of the spine is no single muscle, but the "most important muscle" is a transient definition that depends on the task. All muscles virtually work together to create sufficient stability in all degrees of freedom.8
Current research has not elucidated the most optimal exercises for each individual or situation; however, the combination of science and clinical experience can improve low-back health.9 Developing therapeutic strategies based on academic and clinical evidence and utilizing them in the clinical framework are, however, in increased demand. Concurrent local and global retraining of muscles more efficiently helps functional integration than isolated training of one system, or successive training of one after the other.10
In healthy groups, researchers have tried to quantify lower-back muscles' endurance times and the ratios between extensors, flexor, and lateral flexor groups. These "normal" relative ratios are used to guide clinicians and identify any endurance deficits within specific patients." One study, Alaranta, et al.,12 established a normative database for low-tech functional tests, including sit-ups, arch-ups, squatting, and static back endurance. This study evaluated over 500 subjects of various ages and genders with good-to-excellent reliability for each of the functional tests.
A 41-year-old female presented to a chiropractic office suffering with severe lower-back pain, radiating down the left leg to the calf. Seven months prior, she had had an L5-S1 discectomy. Two months after the surgery, her pain in the lower back and leg returned. An MRI 6 months post-surgery showed no evidence of a recurrent disc herniation, but revealed a slight amount of contrast enhancement along the posterior annulus adjacent to the right Sl nerve root, consistent with post-operative change. Plain film radiography of the lumbar spine did not demonstrate any radiological instability of the lumbar spine and was otherwise unremarkable. The radiographs did not include any stress positions, such as compression or flexion/extension views, which might have helped to demonstrate any radiological instability in this case.13
Clinical examination revealed a restricted forward flexion of 60 degrees, as well as extension to 20 degrees, with pain in the L4-5 paraspinal region. Lateral bending was restricted by pain to 15 degrees on the left and 25 degrees to the right. Manual testing for lumbar joint shear stability, however, was positive. During the test, the patient lies prone on the table with legs over the table and feet on the floor. A downward force is applied to each vertebral segment (L5, L4, L3, etc.). An unstable segment is identified by patient-reported pain or actual displacement felt by the clinician. In this case, reported pain at the L4 segment disappeared with the patient slightly raising her legs and activating the lumbar extensors. This test is positive if pain is present in the resting position, but disappears with active contraction of the lumbar extensors.14
There was motion palpation-elicited pain with endrange pressure at the L4-5 vertebral motion segment with point tenderness of the lumbar erector spinae muscles bilaterally.
Sacroiliac joint testing including passive motion palpation, Gaenslen's, Yeoman's, and Mennell's sacroiliac spring tests were negative. Straight-leg raising was limited to 50 degrees on the left with increased pain in the left buttock and posterolateral thigh (in a non-dermatomal distribution). The right straight-leg raise was 80 degrees with no pain referral into the leg. Neurological examination of the lower limbs elicited a +1 left Achilles tendon reflex, 3/5 motor strength on eversion and plantarflexion of the left foot, and a decrease in pinprick sensation over the lateral aspect of the left foot. The remaining examination of the left leg was normal. The right leg deeptendon reflexes were 2+, and muscle strength was 5/5. Pinprick sensation for the L4, L5, and Sl dermatomes was normal.
A clinical diagnosis of an L5-S1 disc herniation with associated L4-5 facet joint dysfunction and functional instability of the lumbar spine was made. Two weeks of spinal manipulation provided only temporary benefit, with the pain returning within 24 hours posttreatment. There was no change in the neurological findings in the left leg. At this point, it was decided that a low-technique functional capacity evaluation should be done to assess the patient's strength and endurance. This evaluation consisted of 4 functional tests:
1. The repetitive squat test. The patient, standing with feet approximately a shoulder width apart (15 cm), is directed to perform a squat until thighs are horizontal to the floor surface, while maintaining a flat back with heels firmly on the ground. The test rate is set at 1 repetition every 2 to 3 seconds, increased to a maximum amount.12
2. The Sorenson static back endurance test. The patient lies prone on the table with hands along the sides. The inguinal region is brought to the edge of the table with the ankles fixed by the examiner. The upper torso is freely suspended. The patient is requested to stay in the horizontal position as long as possible. The examiner records the time the patient is able to do so.12