Cervical Spondylotic Myelopathy Anterior Corpectomy and Fusion with Plating - Introduction

INTRODUCTION

In 1911, Bailay and Casamajor first described anterior spinal cord compression from posterior protrusion of the intervertebral disc as a result of cervical spondylosis. (2) Stookey further reported in 1928 the affects of cervical spondylosis on spinal cord compression manifesting as quadraplegia. (38) However, cervical spondylotic myelopathy (CSM) first acquired recognition in 1952 by Brain, Northfield, and Wilkinson. (11) Brain et al described the role of vascular spinal cord supply in producing myelopathic symptoms and its associated neurologic manifestations. (11) In the years to follow, Robinson and Smith, (34) Southwick, (37) Cloward, (15,16) Bailey and Badgley, (3) and Simmons and Bhalla (35) developed techniques to treat cervical degenerative disease, trauma, and myelopathy by anterior cervical discectomy and fusion (ACDF). Bohler later facilitated ACDF by introducing anterior cervical plating as a means to increase internal stability, prevent pseudoarthrosis, facilitate fusion, and decrease morbidity. (6)

Although the spinal canal has a diameter of 17 to 18 mm between C3 and C7 and could accommodate various structures, (10,12,13,19,23,29,30) degenerative changes, such as a posterior protruding disc, an ossified posterior longitudinal ligament (OPLL), vertebral osteophytes, facet joint spurs, overriding joint of Luscka, invagination or ossification of the ligamentum flavum, and trauma could contribute to spinal stenosis which leads to compression of the spinal cord and possible cervical kyphosis. (9,11,31,32) Removal of osteophytes in multilevel spinal stenosis has been advocated to reduce decompression. (7,27) Multilevel involvement has been found in CSM patients who are 60 and older. (24) Furthermore, lumbar spondylosis and spinal stenosis has been associated with CSM. (17,20)

Treatment for multilevel cervical spinal stenosis has consisted of anterior or posterior decompression approaches. In regards to one to three level stenosis, an anterior approach is desired. (40) Multiple discectomies and interbody fusion may be appropriate in patients with spinal cord compression due to disc herniation or osteophytes around the disc margins. Multiple level interbody fusion is associate with an increase the risk of psudoarthrosis, (25) may not adequately eliminate osteophyte cord compression, and may not decrease the kyphotic deformity. (39) The use of a corpectomy is indicated in cases of spinal cord compression due to discs or osteophytes that extend beyond the disc margins. Furthermore, it may reduce the rate of nonunion, and remove osteophytes around the spinal cord more safely. (4,18) In addition, corpectomy is advantageous for CSM individuals who are kyphotic. (41) Hence, the following is a case study which highlights an individual with myelopathy secondary to cervical spondylosis and operative treatment via an anterior corpectomy, fusion, and rigid internal fixation.

CASE HISTORY

The patient is a 76 year–old, right hand dominant, Caucasian female with an array of ailments who presented with several months history of left sided head, neck, torso, upper extremity pain, and chronic one–year left lower extremity, back, and gluteal pain. The patient reported that the pain is severe and worse with standing and walking. The patient also complained of right ring and middle finger numbness and tingling. The patient had difficulty ambulating utilizing a cane for the past twenty years. Difficulty sleeping was also reported as a result of pain from the patient's present condition. Furthermore, the patient does not recall any incidence of injury or trauma. The patient also noted no loss of bladder or bowel control. In addition, the patient is status post 16 years spinal lumbar fusion with instrumentation as well as a multitude of other surgeries. Of further interest, the patient lived alone, didn't drink alcohol, was a non–smoker, and was college educated.

Past Medical History

The patient's past medical history and prior surgeries were noted. Medical history was significant for seizure disorder, hypercholesterolemia, intracranial tumors, asthma, emphysema, hepatitis, jaundice, and urinary tract infections. The patient had also multiple skin cancers of the back, neck, and face. The patient underwent operative intervention which included an appendectomy, cholecystectomy, skin cancer excisions, tonsillectomy, hysterectomy, craniotomy, and a lumbar spinal fusion 16 years ago. In addition, the patient underwent an open reduction with internal fixation for correction of a left hip fracture. The procedure was complicated by deep vein thrombosis. Hip hardware was later removed. Other fractures included bilateral distal radial fractures.

Medication

The patient's drug regimen consisted of Prednisone 5mg one PO every three days, Lasix 20 mg PO q.o.d., Mesatoin 100 mg three times a day, Potassium 500 mg a day, Vitamin C, Fosamax, and Zoloft 25 mg PO every day. The patient is allergic to Penicillin.

Physical Examination

The patient is 5'2'' tall and weighs 120 pounds. The patient's physical examination revealed tenderness in the posterior spinous processes of the lower cervical spine and reduced and painful range of motion. Cervical neck range of motion revealed a 25 degree extension and 25 degree flexion. Right lateral bending revealed 20 degrees and 30 degrees on left lateral flexion. The patient displayed 45 degrees of left and right lateral cervical rotation. All cervical flexion and extension was accompanied with pain. The patient had a positive Hoffman sign, but negative clonus and Babinski signs. The patient demonstrated a bilateral 4+/5 grip, intrinsic, biceps, and tricep strength. However, the patient's biceps' reflex revealed a 3+/5 on the left side and a 2+/5 on the right and a 2+/5 on bilateral brachial radialis reflexes. Lower extremity strength presented normal with intact sensation in both extremities. Moreover, examination of patellar reflexes indicated a 3+/5 on the right and a 1+/5 on the left. The patient also exhibited an Achilles reflex of 2+/5 on the right and a 1+/5 on the left . Hips presented normal range of motion without pain.

Radiographs

Plain radiographs indicated moderately advanced degenerative changes in the cervical spine with intervertebral disc space narrowing of C4 – C5, C5 – C6, and C6 – C7 (Fig. 1: A, B). Hypertrophic changes were noted on all neural foramina from C4 to C7. Cervical MRI scan revealed degenerative disc change, severe spinal and foraminal stenosis, and subsequent spinal cord compression. Mild thecal sac effacement was present anteriorly and posteriorly from C4 through C6 – C7. Disc degenerative changes were noted at C4 – C5 through C6 – C7 (Fig 2). Axial images indicated posterior spur formation resulting in right foraminal stenosis and moderate central spinal stenosis at C4 – C5 (Fig 3: A, B). Moreover, at the level of C5 – C6, presence of severe central spinal stenosis accompanied with bilateral foraminal stenosis was evident as a result of bilateral posterior spurs. Furthermore, posterior spur formation with bilateral foraminal stenosis and mild to moderate central stenosis was also present at C6 – C7 coupled with a posterior disc bulge at C6 – C7.

Radiographs of the lumbar, hip, and both hands were taken. Lumbar AP and lateral plain radiographs projected a previous laminectomy at L3 to S1 with posteriolateral fusion from L3 to S1 with Luque rod instrumentation and sublaminar wires . Severe degenerative changes at the upper lumbar region were also noted. Further degenerative changes were observed in bilateral sacroiliac joints. Moderate osteopenia was also evident. Lumbar CT axial images from L3 to S1 noted bilateral hypertrophic facet degenerative changes and severe stenosis at L2–3 level. No disc herniation or narrowing of the neural foramina existed. Left hip plain radiographs indicated a mild vagus deformity on the left proximal femur. Presence of a previous hip screw from a prior fracture was noted. Good hip fracture healing was evident with no signs of osteonecrosis or posttraumatic arthritis. Moreover, the patient possessed a well–maintained joint space of the hip with no intrinsic disease.

In summary, this patient presented a history of multiple medical ailments, cervical spondylotic myelopathy due to cervical stenosis at C4–5, C5–6 and perhaps at C6–7 levels and concomitant lumbar radiculopathy and neurogenic claudication due to lumbar stenosis at L2–3 level. Because of her progressive symptoms despite conservative treatment and signicant cervical spondylotic myelopathy, surgical treatment of cervical stenosis was recommended. Lumbar stenosis was further treatment with anti–inflammatory medications, epidural steroids, and physical therapy