Osteopathic Manipulative Treatment for the Management of Adjacent Segment Pathology

Report of Case

A 50-year-old woman presented to the osteopathic manipulative medicine clinic with a 12-month history of low back pain (LBP), which she described as a burning, sharp pain that radiated down her right lower limb to the anterior and lateral distal calf, stopping just above her ankle. The patient underwent a posterior spinal fusion to stabilize a T4-L4 S-shaped scoliotic curve 35 years previously. Cobb angle measures taken after the spinal fusion were 26° with a convex right curve from T4 to T11 and 25° with a convex left curve from T12 to L4.

One year earlier, 34 years after the spinal fusion, the patient presented to a physiatrist after a series of migraines and neck, back, and lower limb pain. At that time, an MR image of the thoracolumbar spine measured a thoracic curve at 35° convex right and a thoracolumbar curve at 31° convex left. An MR image of the lumbar spine taken at the same time demonstrated significant degenerative changes at L5-S1 and upward migration of disk fragment in the right lateral recess at L4-L5. Physical therapy was recommended, and the patient attended 1 to 2 sessions per week for approximately 12 months, but it did not improve her symptoms.

At the current presentation, the patient reported that her pain was a 6 out of 10 on a 10-point scale (1 being the least pain and 10 being the most) at worst and that it could bring her to tears while exercising. She denied weakness, numbness, or tingling in the lower limb. Her symptoms improved when she was resting in the supine position or in a swimming pool. She took nonsteroidal anti-inflammatory drugs for pain relief, as needed. She reported that her symptoms interfered with her ability to complete daily activities. She described an overall goal of decreasing her daily LBP and right sciatica pain, as well as improving her level of function without medication.

Physical examination of the musculoskeletal system while standing revealed somatic dysfunction in the right superior iliac crest and greater trochanter. Lumbar range of motion was decreased in flexion, extension, rotation, and sidebending. Oblique rotation to the right provoked pain near the right posterior superior iliac spine. A neurologic examination showed intact sensation to light touch and pinprick in the bilateral L2-S2 dermatomes. Manual motor examination revealed weakness on the right side, with 4 out of 5 strength on a 5-point motor examination scale (0 being no response and 5 being full strength against resistance) in the hip flexors, hip abductors, extensor hallucis longus, and ankle everters. The right patella deep tendon reflex was diminished. Straight leg raise test results were negative bilaterally for dural tension in seated and supine positions. The patient's symptoms and examination findings were clinically consistent with a right L4 radiculopathy, likely a consequence of ASP, and repeated lumbar MR imaging was recommended to confirm the diagnosis. In addition, a repeated postural test for Cobb angle measurements was recommended because of the potential of scoliotic curvature progression and possible fusion failure. Comparison with previous radiographic images was advised.

At the patient's first follow-up appointment, 7 days after initial presentation, she had not undergone the recommended MR imaging of the lumbar spine or postural study. During the appointment, OMT techniques (ie, counterstrain, myofascial release, muscle energy, and Still technique) were performed to address the somatic dysfunctions found in the patient's head and cervical, thoracic, lumbar, sacral, pelvic, and lower-limb regions. Considering the patient's likely lumbar ASP, indirect and passive techniques were used when addressing the lumbar spine and pelvic regions. The OMT was well tolerated, and somatic dysfunctions improved in all regions immediately after treatment.

At the second follow-up appointment, 15 days after initial presentation, the MR image of the lumbar spine and postural study had still not been performed. The patient reported that her pain was significantly reduced and intermittent, and that the pain in her lower back and right thigh were 1 out of 10. Using a similar approach as the previous appointment, OMT was performed to address the somatic dysfunctions in the head and cervical, thoracic, lumbar, sacral, pelvic, and lower-limb regions. Again, considering the patient's likely lumbar ASP, indirect and passive techniques were used when addressing the lumbar spine and pelvic regions.

Sixteen days after initial presentation, the postural study was performed, and results revealed stable scoliotic curves, including scoliosis of the thoracic spine convex to the right at 23° and scoliosis of the lumbar spine convex to the left at 24°. An MR image of the lumbar spine was obtained 17 days after initial presentation and confirmed the right L4 radiculopathy with an L4-5 disk protrusion impinging on the right L4 nerve root in the neural foramen.

At the third follow-up appointment, 24 days after initial presentation, the patient reported intermittent pain in her lower back and upper-right buttock, which, at worst, was a 1 on a 10-point pain scale. She denied lower-limb weakness, numbness, tingling, or radiation of pain distally in the right thigh or calf. She reported that the OMT helped reduce her pain and improve her range of motion and that her symptoms were much less frequent, which enabled her to better tolerate her daily activities. It was recommended that further evaluation be done if symptoms returned in the future.

In a follow-up telephone interview 12 months after her initial presentation, the patient reported lasting resolution of her LBP and sciatica symptoms. Her LBP was intermittent, between 0 and 2 on a 10-point pain scale. Her sciatica symptoms were infrequent and did not interfere with her daily activities. She was able to work 3 days per week, complete her daily activities, and volunteer regularly. She had been able to manage her LBP and sciatica symptoms with mindfulness, a daily yoga-stretching regimen, swimming pool exercise, and rest. Overall, she described an improved quality of life and high level of function.

Discussion

Adjacent segment pathology is a well-described adverse outcome of spinal fusion.^6-8 Lumbosacral radiculopathy is one of the potential outcomes of the degenerative spinal conditions caused by ASP. An in vitro study⁹ showed increased intradiskal pressure during flexion in vertebral levels above a simulated spinal fusion, and that pressure increased as the number of spinal levels fused increased.⁹ Nachemson and Morris¹⁰ showed that pressure on the nucleus of disks was directly related to the magnitude of the axial pressure. In addition, Bydon et al¹¹ demonstrated a higher incidence of ASP in patients with fusions that did not extend to the sacrum, referred to as floating fusions. These findings show that conditions that increase pressure in fused spines predispose the adjacent vertebral units to significantly increase degenerative changes associated with ASP, such as radiculopathy.

The patient in the current case had a posterior spinal fusion from T4-L4 and, subsequently, a L4-L5 disk herniation developed with a concurrent right-sided radiculopathy as a consequence of ASP. She met numerous criteria predisposing her to ASP-derived radiculopathy, including her age, fusion length, increased axial pressure, and presence of a floating fusion.^11,12 A conservative approach of OMT decreased her symptoms. The relationship between pathologic conditions of the lower back and the severity of somatic dysfunctions is established in osteopathic literature.¹³ DiStefano¹⁴ noted a correlation between lumbar nonneutral segmental somatic dysfunctions and herniated intervertebral disk. When radiculopathy is caused by a herniated disk, such as in the current case, a management approach that includes OMT can target the improvement of segmental motion and reduction of myofascial tension on the affected vertebral units.¹⁵ Osteopathic manipulative treatment provides a means of reducing pressure and forces acting on disks by addressing the vertebral joint and soft tissue (muscle, tendon, ligament, fascia) restrictions above and below the affected vertebral unit.¹⁶ For example, using OMT to address myofascial strains in soft tissue attached to or crossing the lumbar spine, such as the iliopsoas and quadratus lumborum, can help reduce tension on the vertebrae. This approach reduces the mechanical strain surrounding the injured disk by focusing on the restoration of normal joint motion and balancing myofascial tension to manage discogenic radiculopathy.¹⁴

The common compensatory pattern described by Zink and Lawson¹⁷ could also be used when treating patients with radiculopathy, as it provides a means of efficiently managing areas of significant dysfunction. Addressing the transition zones of the spine (cervicothoracic, thoracolumbar, lumbopelvic) reduces the restrictions of these regions and allows for more slack within a patient's neuromusculoskeletal system. Even in patients with a surgically fused scoliotic curve, such as in the current case, treatment of the fascial patterns at the transition zones can still be performed with significant benefit. Additionally, this approach could help to improve respiration and circulation throughout the body.¹⁷ We propose that this improvement in circulation may serve to decongest the focal edema surrounding the nerve root, thus decreasing pressure and reducing radicular symptoms. In the current case, the common compensatory pattern was used as an osteopathic screening examination to identify the areas of greatest myofascial tension, and the segmental approach was used to help restore normal motion of the thoracic, lumbar, sacral, and innominate joints.

The exact mechanism by which OMT improves radiculopathy caused by disk herniation is unknown.¹⁸ The effect is unlikely related to a reduction in size of the herniation, because the appearance of the herniated disk is unchanged in most cases.^14,18 Further research is warranted to examine the role of OMT in managing ASP-related radiculopathy and to identify any potential adverse effects.

Conclusion

Management of ASP-associated radiculopathy using OMT led to a lasting subjective improvement in pain, sciatica symptoms, and daily function. Furthermore, our brief trial of OMT was more beneficial than a year of conventional conservative approaches (physical therapy and nonsteroidal anti-inflammatory drugs) and extinguished the need for an additional surgical procedure. Extensive biomechanical research is warranted to clarify the exact mechanisms by which OMT reduces symptoms in cases of radiculopathy.