Edward J. Goldberg

Is autograft the gold standard in achieving radiographic fusion in one-level anterior cervical discectomy and fusion with rigid anterior plate fixation?

Study Design. A review of 66 consecutive patients at a single institution who underwent one-level anterior cervical discectomy and fusion (ACDF) with rigid anterior plate fixation with allograft or autograft. Objectives. To address the efficacy of allograft to autograft with primary respect to fusion rate and secondary attention to risk factors and clinical outcome in patients undergoing one-level ACDF with rigid anterior plate fixation. Summary of Background Data. Although autograft is considered the gold standard in achieving optimal fusion, when compared with allograft in noninstrumented one-level ACDF and in plated and nonplated multilevel ACDF, the efficacy of allograft to autograft in one-level ACDF with rigid anterior plate fixation is not thoroughly understood. Methods. Sixty-six consecutive patients (mean age, 45 years) at a single institution who underwent one-level ACDF with rigid anterior plate fixation with allograft (n = 35) or autograft (n = 31) were reviewed for radiographic fusion (mean, 12 months), risk factors, and clinical outcome (mean, 17 months). Smokers entailed 33.3% of the patients, and 45.5% of all patients presented with a work-related injury. An independent blinded observer reviewed at last follow-up lateral neutral and flexion/extension plain radiographs for radiographic fusion and instrumentation integrity. Clinical outcome was assessed on last follow-up and rated according to the Odom criteria. The threshold for statistical significance was established at P < 0.05. Results. Solid fusion was achieved in 63 patients (95.5%). Fusion was noted in 100% of the allograft patients, whereas 90.3% of the autograft cases achieved fusion. No statistically significant difference was noted between allograft to autograft with regard to fusion rate (P > 0.05). Three patients developed nonunions (1 smoker; 2 nonsmokers) and entailed Orion instrumentation. In the one patient who was a nonsmoker with a nonunion, slight screw penetration into the involved and uninvolved interbody spaces was noted. No other intraoperative, postoperative, or radiographic complication was noted. All of the nonunions occurred early in the series. Postoperatively, excellent results were reported in 19.7%, good results in 71.2%, and fair results in 9.1% of the patients. Satisfactory clinical outcome was noted in all nonunion patients. A nonstatistically significant difference was noted with regard to clinical outcome of fused and nonfused patients, demographics, and the presence of a work-related injury (P > 0.05). The impact of smoking was not a factor influencing fusion or clinical outcome in this series (P > 0.05). A statistically significant difference was noted in plate-type on fusion rate (P < 0.05). Conclusion. A 100% and 90.3% radiographic fusion rate was obtained for allograft and autograft in one-level ACDF procedures with rigid anterior plate fixation, respectively. Although autograft achieved a higher incidence of nonunion than allograft, this may be attributed to the use of autograft early in the experience of plate application and fixation in this series. The effects of smoking were not found to be a significant factor influencing fusion in these plated patients. In 90.9% of the patients, excellent and good clinical outcome results were reported. The use of allograft in one-level ACDF with rigid plate fixation yields similar and high fusion rates as autograft. The use of allograft bone eliminates complications and pitfalls associated with autologous donor site harvesting. However, the use of autograft is a viable alternative to avoid the risk of infection, disease transmission, and histocompatibility differences associated with allograft. The use of allograft or autograft bone in properly selected patients for one-level ACDF with rigid anterior plate fixation can result in high fusion rates with excellent and good clinical outcomes.

Comparison of allograft to autograft in multilevelanterior cervical discectomy and fusion with rigid plate fixation

BACKGROUND CONTEXT A relatively high pseudarthrosis rate is associated with multilevel anterior cervical discectomy and fusion (ACDF). Anterior plate fixation increases fusion rate in multilevel ACDF. A debate still exists between the effectiveness of allograft versus autograft in plated multilevel ACDF. PURPOSE To determine the efficacy of allograft versus autograft in fusion rate and clinical outcome in patients undergoing two- and three-level ACDFs with rigid anterior plate fixation. STUDY DESIGN A retrospective radiographic and clinical review to assess fusion, risk factors and clinical outcome of 80 consecutive patients who underwent ACDF with rigid anterior plate fixation involving two and three levels with either allograft or autograft. PATIENT SAMPLE There were 45 patients (56%) who had autogenous iliac crest tricortical grafts and 35 patients (44%) who received tricortical allograft with an average age of 49 years who were treated by multilevel ACDF with rigid anterior plate fixation at a single institution. Thirty-three Peak polyaxial (Depuy-Acromed, Rayham, MA), 26 Orion (Sofamor-Danek, Memphis, TN), 16 Atlantis (Sofamor-Danek, Memphis, TN) and 5 Synthes (Paoli, PA) anterior cervical plating systems were used. All patients underwent ACDF (61 two-level, 19 three-level) by a Smith Robinson technique. All patients had burring of the end plates, 2-mm distraction of the motion segment and graft countersunk 2 mm from the anterior vertebral border. Anterior cervical plate with unicortical screw purchase was used in all cases. Segmental screw fixation was performed in 46 patients. Soft collars were worn postoperatively for 3 to 4 weeks. OUTCOME MEASURES Follow-up lateral neutral, flexion and extension radiographs were used to assess fusion. The radiographs were reviewed by an independent blinded observer in assessing fusion grades between autograft versus allograft. Clinical outcomes were rated excellent, good, fair and poor based on Odoms criteria. METHODS Fusion rate and postoperative clinical outcome were assessed in 80 patients who underwent two- or three-level ACDF with rigid anterior plate fixation. Additional risk factors were also analyzed. RESULTS Radiographic fusion was assessed in all patients (mean, 16 months). Seventy-eight patients (97.5%) achieved solid arthrodesis. Pseudarthrosis occurred in two patients who had allograft for two-level and three-level fusions. Nonsegmental screws were used in the two-level nonunion case. Postoperative dysphagia developed in one two-level nonunion patient, and revision surgery was performed in the other nonunion three-level patient. Twenty-three patients were smokers, and 26 patients had work-related injuries. Clinical outcome (mean, 20 months) was excellent in 23, good in 48 and fair in 9 patients. No statistical significance was noted between demographics, history of tobacco use, graft-type, end plate preparation technique, intermediate segmental screws, plate-type, clinical outcome of fused and nonfused patients and presence of work-related injuries (p>.05). CONCLUSIONS A high fusion rate of 97.5% was obtained for multilevel ACDF with rigid plating with either autograft or allograft. In this study, nonunion occurred in patients with allograft but this difference was not statistically significant. Fusion was obtained in 97.8% of patients with segmental screw fixation and 97.1% with nonsegmental screw fixation. Nonsegmental screw fixation may contribute to less than adequate stability and contribute to a higher rate of nonunion, but such effects could not be discerned from this study. Excellent and good clinical outcome was noted in 88.8% of the patients. Proper patient selection and meticulous operative technique is essential to obtain high fusion rates and optimal clinical outcome, which is more important than graft type.

Comparing outcomes of anterior cervical discectomy and fusion in workman's versus non–workman's compensation population

BACKGROUND CONTEXT Anterior cervical discectomy and fusion (ACDF) is an accepted surgical procedure to treat degenerative conditions, including disc herniations and spinal stenosis. The literature on lumbar spine surgery reports that patients with a workmans compensation claim have less successful clinical results. Regarding the cervical spine, however, different conclusions have been drawn. PURPOSE The purpose of this study was to directly compare the functional outcomes of ACDF in patients with and without a workmans compensation claim and to determine whether a compensation claim adversely affected the clinical outcome. STUDY DESIGN This is a retrospective study examining the long-term results of ACDF in the workmans and non-workmans compensation populations. PATIENT SAMPLE Eighty consecutive patients undergoing ACDF were retrospectively analyzed. The patients were divided into two groups: 30 patients in Group 1 (workmans compensation) and 50 patients in Group 2 (non-workmans compensation). The average age of Group 1 was 45 years (range, 31 to 57) and Group 2 was 45 years (range, 30 to 79). The patients were followed for an average length of 4 years (range, 2 to 7 years). OUTCOME MEASURES We evaluated the surgical results using a functional outcome scoring system (Odoms Criteria), visual analog scale and a radiographic grading scale. The questionnaire was independently administered in a standard question-answer format at the 1-year follow-up. Statistical analyses was performed using a Levenes test. METHODS All surgeries were performed by the same attending physician. A left-sided approach and Smith-Robinson fusion technique with autograft or allograft without instrumentation was used in all cases. A hard cervical orthosis was used postoperatively for 8 weeks. Radiographic examination including lateral flexion and extension views were obtained at a minimum of 12 months postoperatively. Furthermore, radiographic analysis was performed each subsequent postoperative year. The radiographs were analyzed by two independent physicians in a blind fashion for evidence of radiographic fusion. RESULTS At follow-up no discernible difference was noted for functional outcomes. Eighty-three percent of patients in Group 1 and 90% of patients in Group 2 noted excellent or good results. This was not statistically significant (p=.280). In Group 1, 97% of patients returned to work at an average of 18 weeks, whereas 98% of patients in Group 2 returned to work at an average of 10 weeks postoperatively. Upon radiographic evaluation, 64% of patients in Group 1 were determined to have a solid fusion (Grade 3). The fusion rate in Group 2 was 72%. This was not statistically significant. However, the fusion rate among smokers was 50%, and among nonsmokers it was 80%. This was statistically significant (p=.001). CONCLUSIONS Workmans compensation claims did not adversely affect the functional outcome of ACDF. It should be noted that a significant increase in pseudarthroses was noted with the smoking population. Patient selection is a critical factor in determining functional outcome, with 83% good to excellent results if the pathology, clinical presentation and radiographic findings correlate

Factors affecting reoperations after anterior cervical discectomy and fusion within and outside of a Federal Drug Administration investigational device exemption cervical disc replacement trial

BACKGROUND CONTEXT The excellent clinical results of five US Federal Drug Administration (FDA) trials approved for cervical total disc replacement (TDR) (Prestige [Medtronic Sofamor Danek, Memphis, TN, USA], Bryan [Medtronic Sofamor Danek], ProDisc-C [Synthes, West Chester, PA, USA], Kineflex|C [SpinalMotion, Mountain View, CA, USA], and Mobi-C [LDR Spine, Austin, TX, USA]) have recently been published. In these prospective randomized studies, superiority or equivalency of TDR was claimed, citing an 8.7% (23/265), 9.5% (21/221), 8.5% (9/106), 12.2% (14/115), and 6.2% (5/81) (mean = 9.02%) rate of additional related cervical surgical procedures within 2 years in control anterior cervical discectomy and fusion (ACDF) patients, respectively, compared with 1.8% (5/276), 5.8% (14/242), 1.9% (2/103), 11% (15/136), and 1.2% (2/164) (mean = 4.34%) in patients receiving the cervical TDR. The rate of reoperation within 2 years after ACDF seems unusually high. PURPOSE To assess the rate of and specific indications for early reoperation after ACDF in a cohort of patients receiving the ACDF as part of their customary care. These results are contrasted with similar patients receiving ACDF as the control arm of five FDA investigational device exemption (IDE) studies. STUDY DESIGN Multisurgeon retrospective clinical series from a single institution. PATIENT SAMPLE One hundred seventy-six patients with spondylotic radiculopathy or myelopathy underwent ACDF by three surgeons between 2001 and 2005 as part of their clinical practices. All patients had at least 2 years of follow-up with final follow-up within 6 months of completion of this study. OUTCOME MEASURES Cervical reoperation rates at 2-year follow-up and at 3.5-year follow-up. METHODS Review of medical records and telephone conversations were completed to determine the number of patients who had undergone a revision cervical procedure. RESULTS At final follow-up, complete data were available for 159 ACDF patients. Of the 48 patients who underwent single-level ACDF and met criteria for inclusion in the IDE studies, one patient (2.1%) required additional surgery (adjacent-segment degeneration) within 2 years, the duration of follow-up of the five published IDE studies. Of the 159 patients who received single or multilevel ACDF at a mean follow-up of 3.5 years, 12 patients (7.6%) had undergone revision cervical surgery, with three patients (1.9%) undergoing same-level revisions (posterior fusion) and nine patients (5.7%) undergoing adjacent anterior level fusions. Patients who underwent revision same-level surgery typically had the intervention within the first year (mean, 11 months), whereas those requiring adjacent-level fusions typically had surgery later (mean, 29 months). CONCLUSIONS The present study identifies a 2.1% rate of repeat surgery within 2 years of a single-level ACDF performed during routine clinical practice, which is lower than that reported in the control arm of the Prestige, ProDisc-C, Bryan, Kineflex|C, and Mobi-C FDA trials (mean=9%). Even with longer follow-up including multilevel cases, our reoperation rate (7.6%) compared favorably with the IDE rates. This discrepancy may reflect different thresholds for reoperation in the control arm of a device IDE study compared with routine clinical practice. Additionally, patients enrolled in the single-level-only IDE trial may have received multilevel procedures outside of the study. This factor could result in a higher rate of subsequent surgeries at adjacent levels not addressed at the index procedure. These data suggest that we need to better understand factors driving treatment and, in particular, decisions to reoperate both in and outside of a device trial.

Friday, September 28, 2018 3:00 PM–4:00 PM abstracts: optimizing lumbar disc surgery

BACKGROUND CONTEXT Application of nerve root block mainly for the diagnosis but less application in intraoperative treatment. PURPOSE To observe the effect of application of gelatin sponge impregnated a mixture of three drugs (GSIAM) to intraoperative nerve root block to promote early postoperative recovery of lumbar disc herniation (LDH). STUDY DESIGN/SETTING A total of 265 patients with single-level LDH were retrospectively analyzed from January 2013 to October 2017. Patients were divided into intervention group and control group according to whether intraoperative GSIAM. PATIENT SAMPLE A total of 265 patients with single-level LDH were retrospectively analyzed from January 2013 to October 2017. Patients were divided into intervention group and control group according to whether intraoperative GSIAM. OUTCOME MEASURES All patients underwent unilateral MIS-TLIF surgery. Clinical data such as bedbound period, postoperative hospital stays, VAS score of low back pain and leg pain, JOA score, postoperative satisfaction questionnaire results, and therapeutic effect were collected. METHODS A total of 265 patients with single-level LDH were retrospectively analyzed from January 2013 to October 2017. Patients were divided into intervention group and control group according to whether intraoperative application of GSIAM. All patients underwent unilateral MIS-TLIF surgery. Clinical data such as bedbound period, postoperative hospital stays, VAS score of low back pain and leg pain, JOA score, postoperative satisfaction questionnaire results, and therapeutic effect were collected. RESULTS A total of 136 cases were included in the intervention group. A total of 129 cases were included in the control group. The intervention group had significantly shorter bedbound period and postoperative hospital stays than the control group (P CONCLUSIONS Application of GSIAM to intraoperative nerve root block can significantly promote the early postoperative recovery of LDH, and has great short-term clinical efficacy.