POSTERIOR CERVICAL SPINE FIXATION UTILIZING SEGMENTAL SCREW–ROD FIXATION

Abstract

Posterior segmental fixation of the cervical spine facilitates fixation in sub-optimal bone, abnormal anatomy, and complex deformity. Compared to lateral mass plates a screw rod construct provides a stable construct in osteoporotic bone or in cases where the lateral masses are fractured or missing.

To investigate whether a posterior cervical screw- rod construct is an effective, stable and safe means of posterior cervical fixation.

Retrospective evaluation of consecutive patients undergoing a posterior cervical stabilization with a screw- rod construct with clinical and radiographic evaluation.

Clinical variables included age, gender, neurologic status, surgical indication, number of levels stabilized, and number of screws. Note was made as to whether a laminectomy was performed and concomitant anterior surgery. Clinical and radiographic assessments were carried out immediately after surgery and at six weeks, three, six, twelve months and annually after surgery.

Eighty-three patients had five hundred and seventy-three screws placed from October 1998 to December 2003. Mean patient age was fifty-seven. Mean follow-up was twenty-three months, (one to sixty months). The underlying diagnoses were inflammatory arthritis thirty-three, spondylotic myelopathy twenty-nine and trauma in twenty-one patients. Forty-four patients (53% had motor deficit, forty-seven patients (57%) had sensory deficit. Fixation was carried out over an average of five levels (range – two to eight). Mean number of screws per construct was seven (range – four to fourteen). The instrumentation was successfully implanted in all despite lateral mass deficiencies (fracture, poor bone) and coronal and sagittal plane deformities. Late occipital fixation failure was encountered in one patient. There was no loss of alignment or surgical correction on follow-up radiographs.

A posterior screw-rod system allows for treatment of traumatic and degenerative and inflammatory conditions. Crossing the occipitocervical or cervicothoracic junctions is easily afforded. We have had excellent success without complications from screw placement or pseudoarthrosis.