Impact of Cervical Disc Arthroplasty vs Anterior Cervical Discectomy and Fusion on Driving Disability: Post Hoc Analysis of a Randomized Controlled Trial With 10-Year Follow-Up.

BACKGROUND: Driving an automobile requires the ability to turn the neck laterally. Anecdotally, patients with multilevel fusions often complain about restricted turning motion. The purpose of this study was to compare the effectiveness of cervical disc arthroplasty (CDA) with anterior cervical discectomy and fusion (ACDF) on driving disability improvement at 10-year follow-up after a 2-level procedure. METHODS: In the original randomized controlled trial, patients with cervical radiculopathy or myelopathy at 2 levels underwent CDA or ACDF. The driving disability question from the Neck Disability Index was rated from 0 to 5 years preoperatively and up to 10 years postoperatively. Severity of driving disability was categorized into "none" (score 0), "mild" (1 or 2), and "severe" (3, 4, or 5). Score and severity were compared between groups. RESULTS: Out of 397 patients, 148 CDA and 118 ACDF patients had 10-year follow-up. Driving disability scores were not different between the groups preoperatively (CDA: 2.65; ACDF: 2.71, P = 0.699). Postoperatively, the scores in the CDA group were significantly lower than those in the ACDF group at 5 (0.60 vs 1.08, P ≤ 0.001) and 10 years (0.66 vs 1.07, P = 0.001). Mean score improvement in the CDA group was significantly greater than the ACDF group at 10-year follow-up (-1.94 vs -1.63, P = 0.003). The majority of patients reported severe driving disability (CDA: 56.9%, ACDF: 58.0%, P = 0.968) before surgery. After surgery, a greater proportion of patients in the CDA group had neck pain-free driving compared with the ACDF group at 5 (63.3% vs 41.8%, P < 0.001) and 10 years (61.8% vs 41.2%, P = 0.003). CONCLUSION: In patients with cervical radiculopathy/myelopathy and 2-level disease, CDA provided greater improvements in driving disability as compared with ACDF at 10-year follow-up. This is the first report of its kind. This finding may be attributable to preservation of motion associated with CDA. CLINICAL RELEVENCE: This study provides valuable information regarding the improvement of driving disability after both CDA and ACDF. It demonstrates that both procedures result in significant improvements, with CDA resulting in even better improvements than ACDF, up to 10 year follow-up.

Heterotopic ossification following single-level anterior cervical discectomy and fusion: results from the prospective, multicenter, historically controlled trial comparing allograft to an optimized dose of rhBMP-2.

OBJECTIVE Heterotopic ossification (HO) has been reported following total hip, knee, cervical, and lumbar arthroplasty, as well as following posterolateral lumbar fusion using recombinant human bone morphogenetic protein-2 (rhBMP-2). Data regarding HO following anterior cervical discectomy and fusion (ACDF) with rhBMP-2 are sparse. A subanalysis was done of the prospective, multicenter, investigational device exemption trial that compared rhBMP-2 on an absorbable collagen sponge (ACS) versus allograft in ACDF for patients with symptomatic single-level cervical degenerative disc disease. METHODS To assess differences in types of HO observed in the treatment groups and effects of HO on functional and efficacy outcomes, clinical outcomes from previous disc replacement studies were compared between patients who received rhBMP-2/ACS versus allograft. Rate, location, grade, and size of ossifications were assessed preoperatively and at 24 months, and correlated with clinical outcomes. RESULTS Heterotopic ossification was primarily anterior in both groups. Preoperatively in both groups, and including osteophytes in the target regions, HO rates were high at 40.9% and 36.9% for the rhBMP-2/ACS and allograft groups, respectively (p = 0.350). At 24 months, the rate of HO in the rhBMP-2/ACS group was higher than in the allograft group (78.6% vs 59.2%, respectively; p < 0.001). At 24 months, the rate of superior-anterior adjacent-level Park Grade 3 HO was 4.2% in both groups, whereas the rate of Park Grade 2 HO was 19.0% in the rhBMP-2/ACS group compared with 9.8% in the allograft group. At 24 months, the rate of inferior-anterior adjacent-level Park Grade 2/3 HO was 11.9% in the rhBMP-2/ACS group compared with 5.9% in the allograft group. At 24 months, HO rates at the target implant level were similar (p = 0.963). At 24 months, the mean length and anteroposterior diameter of HO were significantly greater in the rhBMP-2/ACS group compared with the allograft group (p = 0.033 and 0.012, respectively). Regarding clinical correlation, at 24 months in both groups, Park Grade 3 HO at superior adjacent-level disc spaces significantly reduced range of motion, more so in the rhBMP-2/ACS group. At 24 months, HO negatively affected Neck Disability Index scores (excluding neck/arm pain scores), neurological status, and overall success in patients in the rhBMP-2/ACS group, but not in patients in the allograft group. CONCLUSIONS Implantation of rhBMP-2/ACS at 1.5 mg/ml with polyetheretherketone spacer and titanium plate is effective in inducing fusion and improving pain and function in patients undergoing ACDF for symptomatic single-level cervical degenerative disc disease. At 24 months, the rate and dimensions (length and anteroposterior diameter) of HO were higher in the rhBMP-2/ACS group. At 24 months, range of motion was reduced, with Park Grade 3 HO in both treatment groups. The impact of Park Grades 2 and 3 HO on Neck Disability Index success, neurological status, and overall success was not consistent among the treatment groups. The study data may offer a deeper understanding of HO after ACDF and may pave the way for improved device designs. Clinical trial registration no.: IDE# G060021; data compared with pooled data from control arms of IDE# G010188/NCT00642876 and IDE# G000123/NCT00437190 ( www.clinicaltrials.gov ).

Retrograde ejaculation after anterior lumbar interbody fusion: transperitoneal versus retroperitoneal exposure.

STUDY DESIGN: In this multicenter, prospective, 2-year study, 146 male patients underwent a single-level anterior lumbar interbody fusion with a tapered threaded titanium fusion device. All the patients were advised before surgery of the risk for retrograde ejaculation. After surgery, any case of retrograde ejaculation was recorded as an adverse event, and the patient was observed up for the remainder of the study. OBJECTIVE: To determine the incidence of retrograde ejaculation in male patients treated for single-level degenerative lumbar disc disease at L4-L5 or L5-S1 with a stand-alone anterior interbody fusion using tapered, threaded titanium fusion cages. SUMMARY OF BACKGROUND DATA: The incidence of retrograde ejaculation in men after anterior lumbosacral spinal surgery has been reported to range from 0.42% to 5.9%. Various risk factors that increase the chance of retrograde ejaculation have been proposed. METHODS: In this prospective study, 146 male patients underwent an open surgical exposure of the lumbosacral junction and a single-level interbody fusion at either L4-L5 or L5-S1. Assessment of a patient's clinical outcome was based on written questionnaires at 6 weeks and then 3, 6, 12, and 24 months after surgery. Patients were questioned about adverse events at each of these assessments, and any case of retrograde ejaculation was recorded and followed. RESULTS: Retrograde ejaculation developed in 6 of the 146 men after open anterior lumbar interbody fusion surgery. Two cases (1.7%; 2/116) involved patients who underwent a retroperitoneal surgical exposure. Four cases (13.3%; 4/30) involved patients who had a transperitoneal surgical exposure. This difference is statistically significant according to Fisher's exact test (P = 0.017). At 12 months after surgery, 2 patients had resolution of their symptoms: 1 in the retroperitoneal approach group and 1 in the transperitoneal group. At the final 2-year follow-up, no changes in symptoms were reported. One patient in the retroperitoneal approach group (0.86%) and three patients in the transperitoneal group (10%) reported permanent retrograde ejaculation (P = 0.027). CONCLUSIONS: A transperitoneal approach to the lumbar spine at L4-L5 and L5-S1 has a 10 times greater chance of causing retrograde ejaculation in men than a retroperitoneal approach.