Domagoj Coric

Analysis of the three United States Food and Drug Administration investigational device exemption cervical arthroplasty trials.

OBJECTnThere are now 3 randomized, multicenter, US FDA investigational device exemption, industry-sponsored studies comparing arthroplasty with anterior cervical discectomy and fusion (ACDF) for single-level cervical disease with 2 years of follow-up. These 3 studies evaluated the Prestige ST, Bryan, and ProDisc-C artificial discs. The authors analyzed the combined results of these trials.nnnMETHODSnA total of 1213 patients with symptomatic, single-level cervical disc disease were randomized into 2 treatment arms in the 3 randomized trials. Six hundred twenty-one patients received an artificial cervical disc, and 592 patients were treated with ACDF. In the three trials, 94% of the arthroplasty group and 87% of the ACDF group have completed 2 years of follow-up. The authors analyzed the 2-year data from these 3 trials including previously unpublished source data. Statistical analysis was performed with fixed and random effects models.nnnRESULTSnThe authors analysis revealed that segmental sagittal motion was preserved with arthroplasty (preoperatively 7.26° and postoperatively 8.14°) at the 2-year time point. The fusion rate for ACDF at 2 years was 95%. The Neck Disability Index, 36-Item Short Form Health Survey Mental, and Physical Component Summaries, neck pain, and arm pain scores were not statistically different between the groups at the 24-month follow-up. The arthroplasty group demonstrated superior results at 24 months in neurological success (RR 0.595, I(2) = 0%, p = 0.006). The arthroplasty group had a lower rate of secondary surgeries at the 2-year time point (RR 0.44, I(2) = 0%, p = 0.004). At the 2-year time point, the reoperation rate for adjacent-level disease was lower for the arthroplasty group when the authors analyzed the combined data set using a fixed effects model (RR 0.460, I(2) = 2.9%, p = 0.030), but this finding was not significant using a random effects model. Adverse event reporting was too heterogeneous between the 3 trials to combine for analysis.nnnCONCLUSIONSnBoth anterior cervical discectomy and fusion as well as arthroplasty demonstrate excellent 2-year surgical results for the treatment of 1-level cervical disc disease with radiculopathy. Arthroplasty is associated with a lower rate of secondary surgery and a higher rate of neurological success at 2 years. Arthroplasty may be associated with a lower rate of adjacent-level disease at 2 years, but further follow-up and analysis are needed to confirm this finding.

Treatment of lumbar spinal stenosis with a total posterior arthroplasty prosthesis: implant description, surgical technique, and a prospective report on 29 patients

OBJECTnTotal disc replacement is an alternative to lumbar fusion, but patients with spinal stenosis, spondylolisthesis, and facet arthropathy are often excluded from this procedure because increased adjacent-segment motion can exacerbate dorsal spondylotic changes. In such cases of degenerative spondylolisthesis with stenosis, decompression and fusion remain the gold standard of treatment. To avoid attendant loss of motion at the treated segment, the TOPS system is a novel total posterior arthroplasty prosthesis that allows for an alternative dynamic, multiaxial, three-column stabilization and motion preservation. The purpose of this study is to report preliminary surgical data and clinical outcomes in patients treated with the TOPS lumbar total posterior arthroplasty system.nnnMETHODSnTwenty-nine patients were enrolled in a nonrandomized, multicenter, prospective pilot study outside the US. All patients had spinal stenosis and/or spondylolisthesis at L4-5 due to facet arthropathy. Radiographs and scores on outcome measures including the visual analog scale (VAS) for pain, Oswestry Disability Index (ODI), Short Form-36, and Zurich Claudication Questionnaire were prospectively recorded before surgery and at 6-week, 3-month, 6-month, and 1-year intervals after surgery. Prior to instrumentation, a bilateral total facetectomy and laminectomy at L4-5 or L3-4 was performed via a standard midline posterior approach. After decompression, the TOPS screws were inserted into four pedicles to achieve maximal purchase with triangulating bicortical trajectories. An appropriately sized TOPS arthroplasty implant was then applied. The mean surgical time was 3.1 hours, and patients clinical status improved significantly following treatment with the TOPS device. The mean ODI score decreased compared with baseline by 41% at 1 year, and the 100-mm VAS score declined by 76 mm over the same time period. Radiographic analysis showed that lumbar motion was maintained, disc height was preserved, and no evidence of screw loosening was found. No device malfunctions or migrations and no device-related adverse events were reported during the study.nnnCONCLUSIONSnThe TOPS total posterior arthroplasty system represents a novel, dynamic, posterior arthroplasty device that provides multiaxial stability in flexion, extension, rotation, and lateral bending after total facetectomy and neural decompression. The surgical data indicate that it can be safely applied via a traditional approach with low surgical morbidity and excellent 1-year functional and radiographic outcomes in patients with degenerative spondylolisthesis accompanied by stenosis and back pain.

Minimally invasive cervical microendoscopic laminoforaminotomy

Spine surgery has seen parallel interest and development in the areas of motion preservation and minimally invasive surgery. Posterior microendoscopic laminoforaminotomy (MELF) allows for neural decompression while maintaining motion via a minimally invasive approach. This technique shares the advantage of maintenance of motion with arthroplasty, but without the need for instrumentation. Therefore, the procedure is motion preserving, minimally invasive and cost-effective. The ideal indications for posterior MELF include unilateral radiculopathy secondary to hard disc or spondylosis, as well as soft disc herniations. The authors present a modified surgical technique for posterior MELF as well as a case study illustrating its synergy with anterior arthroplasty.

Minimally invasive versus open fusion for Grade I degenerative lumbar spondylolisthesis: analysis of the Quality Outcomes Database

OBJECTIVE Lumbar spondylolisthesis is a degenerative condition that can be surgically treated with either open or minimally invasive decompression and instrumented fusion. Minimally invasive surgery (MIS) approaches may shorten recovery, reduce blood loss, and minimize soft-tissue damage with resultant reduced postoperative pain and disability. METHODS The authors queried the national, multicenter Quality Outcomes Database (QOD) registry for patients undergoing posterior lumbar fusion between July 2014 and December 2015 for Grade I degenerative spondylolisthesis. The authors recorded baseline and 12-month patient-reported outcomes (PROs), including Oswestry Disability Index (ODI), EQ-5D, numeric rating scale (NRS)-back pain (NRS-BP), NRS-leg pain (NRS-LP), and satisfaction (North American Spine Society satisfaction questionnaire). Multivariable regression models were fitted for hospital length of stay (LOS), 12-month PROs, and 90-day return to work, after adjusting for an array of preoperative and surgical variables. RESULTS A total of 345 patients (open surgery, n = 254; MIS, n = 91) from 11 participating sites were identified in the QOD. The follow-up rate at 12 months was 84% (83.5% [open surgery]; 85% [MIS]). Overall, baseline patient demographics, comorbidities, and clinical characteristics were similarly distributed between the cohorts. Two hundred fifty seven patients underwent 1-level fusion (open surgery, n = 181; MIS, n = 76), and 88 patients underwent 2-level fusion (open surgery, n = 73; MIS, n = 15). Patients in both groups reported significant improvement in all primary outcomes (all p < 0.001). MIS was associated with a significantly lower mean intraoperative estimated blood loss and slightly longer operative times in both 1- and 2-level fusion subgroups. Although the LOS was shorter for MIS 1-level cases, this was not significantly different. No difference was detected with regard to the 12-month PROs between the 1-level MIS versus the 1-level open surgical groups. However, change in functional outcome scores for patients undergoing 2-level fusion was notably larger in the MIS cohort for ODI (-27 vs -16, p = 0.1), EQ-5D (0.27 vs 0.15, p = 0.08), and NRS-BP (-3.5 vs -2.7, p = 0.41); statistical significance was shown only for changes in NRS-LP scores (-4.9 vs -2.8, p = 0.02). On risk-adjusted analysis for 1-level fusion, open versus minimally invasive approach was not significant for 12-month PROs, LOS, and 90-day return to work. CONCLUSIONS Significant improvement was found in terms of all functional outcomes in patients undergoing open or MIS fusion for lumbar spondylolisthesis. No difference was detected between the 2 techniques for 1-level fusion in terms of patient-reported outcomes, LOS, and 90-day return to work. However, patients undergoing 2-level MIS fusion reported significantly better improvement in NRS-LP at 12 months than patients undergoing 2-level open surgery. Longer follow-up is needed to provide further insight into the comparative effectiveness of the 2 procedures.

Women fare best following surgery for degenerative lumbar spondylolisthesis: A comparison of the most and least satisfied patients utilizing data from the Quality Outcomes Database

OBJECTIVE The American Association of Neurological Surgeons launched the Quality Outcomes Database (QOD), a prospective longitudinal registry that includes demographic, clinical, and patient-reported outcome (PRO) data, to measure the safety and quality of neurosurgical procedures, including spinal surgery. Differing results from recent randomized controlled trials have established a need to clarify the groups that would most benefit from surgery for degenerative lumbar spondylolisthesis. In the present study, the authors compared patients who were the most and the least satisfied following surgery for degenerative lumbar spondylolisthesis. METHODS This was a retrospective analysis of a prospective, national longitudinal registry including patients who had undergone surgery for grade 1 degenerative lumbar spondylolisthesis. The most and least satisfied patients were identified based on an answer of 1 and 4, respectively, on the North American Spine Society (NASS) Satisfaction Questionnaire 12 months postoperatively. Baseline demographics, clinical variables, surgical parameters, and outcomes were collected. Patient-reported outcome measures, including the Numeric Rating Scale (NRS) for back pain, NRS for leg pain, Oswestry Disability Index (ODI), and EQ-5D (the EuroQol health survey), were administered at baseline and 3 and 12 months after treatment. RESULTS Four hundred seventy-seven patients underwent surgery for grade 1 degenerative lumbar spondylolisthesis in the period from July 2014 through December 2015. Two hundred fifty-five patients (53.5%) were the most satisfied and 26 (5.5%) were the least satisfied. Compared with the most satisfied patients, the least satisfied ones more often had coronary artery disease (CAD; 26.9% vs 12.2%, p = 0.04) and had higher body mass indices (32.9 ± 6.5 vs 30.0 ± 6.0 kg/m2, p = 0.02). In the multivariate analysis, female sex (OR 2.9, p = 0.02) was associated with the most satisfaction. Notably, the American Society of Anesthesiologists (ASA) class, smoking, psychiatric comorbidity, and employment status were not significantly associated with satisfaction. Although there were no significant differences at baseline, the most satisfied patients had significantly lower NRS back and leg pain and ODI scores and a greater EQ-5D score at 3 and 12 months postoperatively (p < 0.001 for all). CONCLUSIONS This study revealed that some patient factors differ between those who report the most and those who report the least satisfaction after surgery for degenerative lumbar spondylolisthesis. Patients reporting the least satisfaction tended to have CAD or were obese. Female sex was associated with the most satisfaction when adjusting for potential covariates. These findings highlight several key factors that could aid in setting expectations for outcomes following surgery for degenerative lumbar spondylolisthesis.