Wednesday, September 26, 2018 3:35 PM – 5:05 PM Preserving Spinal Motion: 87. Posterior cervical foraminotomy for cervical radiculopathy: should cervical sagittal alignment be considered?

Abstract

BACKGROUND CONTEXT Despite an increasing trend for anterior approach, microsurgical and endoscopic advances have enabled excellent outcomes by minimally invasive posterior cervical foraminotomy with motion preservation, for managing cervical radiculopathy. On the other hand, the poserior approach inherently compromises posterior column integrity, where roughly two-thirds of cervical load is transmitted. Hence, surgeons often avoid posterior cervical foraminotomy in patients presenting with imaging evidence of kyphosis or straightening to prevent postoperative kyphotic deformity. PURPOSE To determine interval changes in cervical segmental angles after postrior cervical foraminotomy and analyzing factors affecting cervical sagittal re-alignment in the postoperative period. STUDY DESIGN/SETTING In this retrospective study, we reviewed interval change in cervical segmental angles after posterior cervical foraminotomy. analyzing factors affecting cervical sagittal re-alignment in the immediate postoperative period and at 6-months follow-up. PATIENT SAMPLE Between January, 2007 and January, 2013, a total of 289 consecutive patients underwent key-hole post cervical foraminotomy at single center for unilateral radiculopathy due to degenerative cervical disease. Patients with myelopathy, neoplasm, congenital deformity, fracture, or history of previous cervical spine surgery were excluded, as were patients with focal instability at affected levels. Pathology predisposing to radiculopathy was softened disc (n=157), foraminal stenosis (n=116), or both (n=16). OUTCOME MEASURES On admission, prior to postoperative radiographs and 6 months after operation follow-up in outpatient, patients were routinely asked to gauge levels of pain they feeling at that point in time by VAS and it was recorded in medical chart. METHODS Within 2 days and 6 months after posterior cervical foraminotomy, postoperative plain radiographs were obtained to compare the cervical sagittal alignment with preoperative alignment in 289 consecutive patients. Sagittal alignment was evaluated using Cobb's angle between C2 and C7 formed by lines drawn at the base of axis and the superior endplate of the C7 vertebral body on the lateral radiograph. To evaluate the clinical outcomes, patients were routinely asked to gauge levels of pain they experienced by VAS on admission, prior to postoperative radiographs and 6 months after operation follow-up in outpatient. RESULTS More than two-third of the patients presenting with kyphotic or straight curvature improved short-term following operation. On follow-up plain radiographs after 6 months, the improvement of sagittal alignment was well maintained, but rather more prominent. Improvement in sagittal alignment was dominant when radiculopathy was due to softened discs, rather than stenosis, and with shorter symptom duration. Patient age had no significant impact on outcomes. In patients with higher preoperative VAS score, Cobb's angle was significantly lower, and as perioperative VAS score declined, sagittal alignment improved significantly. CONCLUSIONS Overall, our data suggest that loss of preoperative cervical lordotic curvature may be a distorted reflection due to pain. Particularly in acute-onset radiculopathies from softened discs, posterior cervical foraminotomy is thus a valid surgical option, despite preoperative loss of normal lordotic sagittal alignment. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.