Background context: The success of arthrodesis for anterior cervical fusion depends on several factors, including the number of surgical levels. Internal fixation putatively improves the arthrodesis rate and outcome.
Purpose: To provide medium-term follow-up data on the surgical success and patient outcome of one- and two-level anterior cervical discectomies and fusions and to determine the effect that plate fixation has on results.
Study design: A prospective study of 40 patients who underwent modified Smith-Robinson anterior cervical discectomy and fusion at one or two operative levels.
Patient sample: Forty patients.
Outcome measures: Odom criteria, Nurick grading system, radiographs.
Methods: Forty patients, with an average age of 44 years (range, 27 to 82), were followed for an average of 51 months (range, 24 to 85). All had an anterior discectomy, burring of the end plates and placement of an autogenous tricortical iliac crest graft at one (20 patients) or two levels (20 patients). Twenty-three were stabilized with the Cervical Spine Locking Plate (Synthes Spine, Paoli, PA), 4 single level, 19 two level. All patients had follow-up office visits with examinations and radiographs. Radiographic union, postoperative pain relief and neurologic recovery were evaluated.
Results: Successful arthrodesis of single-level procedures occurred in 11 of 16 unplated and 2 of 4 plated fusions. Primary bony union in the two-level group was achieved in 15 of 19 plated patients and did not occur in the single unplated procedure. Clinically, there were 12 excellent, 5 good, 3 satisfactory and 0 poor outcomes among the single-level procedures. Among the dual-level procedures, there were 10 excellent, 5 good, 3 satisfactory and 2 poor results. Nine of 16 who developed adjacent-level degeneration had pain. Five of the 9 also had nonunions. Of the 40, 3 had fibrous union at final follow-up, and 10 had revision surgery.
Conclusions: The Cervical Spine Locking Plate improved the outcome of two-level procedures to that of uninstrumented one-level fusions. Adjacent-level degeneration is associated with persistent pain, especially if there is also a nonunion. Primary bony union is paralleled by a better clinical outcome.