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Background Multiple studies describe the outcomes of patients undergoing single-level and multilevel posterolateral lumbar fusion (PLF). However, a comparison of outcomes between single-level and two-level PLF is lacking. The aim of this prospective cohort study was to compare outcomes between single-level and two-level instrumented PLF. Methods A total of 42 patients were enrolled at nine US centers between October 2015 and June 2017. Data included radiologic outcomes, visual analog scale (VAS) Back and Leg Pain, disability per the Oswestry Disability Index (ODI), and health-related quality of life (QoL) per 36-Item Short Form Survey version 2.0 (SF-36v2) at six weeks and three, six, 12, and 24 months. Results Twelve-month and 24-month follow-ups were completed by 38 (90.5%) and 32 (76.2%) subjects, respectively. The average age was 67 years, and 54.8% were female. Twenty-six received single-level PLF, and 16 received two-level PLF. In the single-level group, there was one reoperation, two postoperative infections, and one dural tear. In the two-level group, there was one postoperative infection. The surgeon computed tomography (CT)-based evaluation of fusion rate was 67.6% (25/37) at 12-month follow-up and 94.1% (32/34) at 24-month follow-up. The third-party evaluation of fusion rate was 52.8% (19/36) at six months, 81.1% (30/37) at 12 months, and 86.5% (32/37) at 24 months. There was a tendency toward a higher fusion rate in single-level compared with two-level PLF. The ODI, SF-36v2 Mental Component Score (MCS), and VAS Back Pain and Leg Pain outcomes improved by the first follow-up visit in both the single-level and two-level groups. Improvement in the ODI was 5.86 (95% confidence interval (CI): 0.03-11.69) points greater in the single-level group compared with the two-level group. Conclusions Compared with the two-level PLF subjects, single-level PLF subjects had better functional outcomes and reported higher satisfaction with the outcome of surgery but showed similar fusion, pain, and generic health-related quality of life outcomes. Both single-level and two-level PLF subjects demonstrated high fusion rates in association with improvements in pain, functional, and quality of life outcomes, as well as high satisfaction levels.

BACKGROUND CONTEXT Posterolateral fusion (PLF) is a common procedure for spinal fusion, either stand-alone or in combination with interbody fusion. Achieving solid fusion in stand-alone PLF is challenging. OSTEOAMP® is a novel allograft bone graft substitute (BGS) manufactured using a proprietary process that retains high levels of endogenous growth factors, and offers a promise of an effective solution for BGS in PLF. PURPOSE To compare radiologic and patient outcomes following stand-alone PLF that used a novel BGS vs local autologous bone (LAB). STUDY DESIGN/SETTING A propensity score-adjusted nonconcurrent multicenter prospective cohort study. PATIENT SAMPLE Patients undergoing PLF with either the novel BGS or LAB. The OSTEOAMP group underwent a 1- or 2-level procedure and the LAB group underwent a 1-level procedure. OUTCOME MEASURES Fusion, Oswestry Disability Index (ODI), back and leg pain, SF36 PCS and MCS at 12 months. METHODS Clinical and patient outcomes for PLF using OSTEOAMP (N=38 patients) or LAB (control, N=104 patients) from two prospective studies were compared utilizing a propensity score approach to reduce selection bias in baseline characteristics. After application of propensity score region, 38 OSTEOAMP and 82 LAB patients were included in the analysis. The weighted analysis was performed using propensity scores as weights. Fusion was defined as uni- or bilateral bridging bone on CT scans and an absence of angular and translational motion ( RESULTS The fusion rate was 84% and 61% in the OSTEOAMP and LAB groups, respectively (P=0.028, RR = 1.4 (95% C.I. = 1.0 to 1.9)). At 12-month follow-up, both groups showed statistically significant improvements in all outcomes. There was no difference in ODI outcomes between the groups. The average ODI at 12 months was 20.3 and 18.8 in the BGS and LAB subjects, respectively. There was a marked and significant improvement in SF 36 PCS in both groups (15.4 and 13.1 in BGS and LAB groups, respectively, n.s.). SF 36 MCS improved in both groups (7.1 and 7.6 in BGS and LAB groups, respectively). Both groups experienced similar improvements in back pain and leg pain. Safety outcomes were similar between the groups. CONCLUSIONS OSTEOAMP is a viable replacement for LAB and achieves better radiologic fusion rates and similar patient outcomes in stand-alone PLF. FDA DEVICE/DRUG STATUS OSTEOAMP® is compliant to 21 CFR 1271 and is regulated as a 361 HCT/P.

BACKGROUND CONTEXT While there have been several large-scale FDA investigational device exemption (IDE) studies on single-level cervical total disc replacement (TDR) such information is available for only two devices used for two-level disc replacement. One of these devices has metallic endplates and a plastic core, the other is a two-piece device machined from a titanium-ceramic composite. A TDR designed with titanium-coated PEEK endplates and a biconvex zirconia toughened alumina ceramic core is being evaluated in an IDE trial for two-level implantation. PURPOSE The purpose of this study was to investigate preliminary outcomes of the PEEK-on-ceramic TDR based on three sites participating in the two-level trial. STUDY DESIGN/SETTING This was a prospective study based on data from three of 18 centers participating in the TDR arm of a prospective study evaluating two-level cervical TDR using a nonconcurrent historical control. PATIENT SAMPLE These preliminary outcomes were based on 62 patients at 12 months postoperative following two-level cervical TDR. OUTCOME MEASURES Patient reported outcome measures included the neck disability index (NDI) and numerical rating scores (NRS) separately assessing neck and arm pain intensity. Radiographic measures made at the index levels included disc height and flexion/extension range of motion (ROM). METHODS Patients enrolled in the trial received the Simplify® PEEK-on-ceramic TDR. Evaluations were conducted prior to surgery and at 6 weeks, and 3, 6 and 12 months after surgery. All radiographs were analyzed by an independent lab specializing in image assessment. RESULTS The mean NDI score decreased significantly (p CONCLUSIONS Preliminary results of this IDE study found that two-level cervical TDR using the PEEK-on-ceramic implant was associated with significant decreases in pain and function scores, which were maintained during 12-month follow-up. Disc height of the operated segments were increased after surgery and remained increased through 12-month follow-up. ROM was increased, significantly at the superior level and nonsignificantly at the inferior level. These early results suggest that the device may be a future consideration for the treatment of symptoms arising from two-level degenerative conditions of the cervical spine. Patients from all centers continue to be followed annually. FDA DEVICE/DRUG STATUS Simplify disc (Investigational/Not approved)

BACKGROUND CONTEXT Instrumented posterolateral lumbar fusion (PLF) surgery is commonly used to alleviate pain and other symptoms associated with degenerative conditions of the lumbosacral spine. Although autologous iliac crest bone graft (ICBG) remains the gold standard graft material for PLF, surgeons have sought alternatives to avoid morbidities associated with ICBG harvest. OSTEOAMP® is a novel allograft bone graft substitute (BGS) that retains multiple endogenous growth factors. Evidence concerning effectiveness of PLF in multi-level fusion is scarce. PURPOSE The purpose of this study was to compare 2-year clinical and radiographic outcomes of OSTEOAMP and ICBG in single- and 2-level PLF. STUDY DESIGN/SETTING This was a prospective multicenter cohort study (level 2 evidence) involving nine centers in the United States. PATIENT SAMPLE A total of 42 patients with Oswestry Disability Index (ODI) score of at least 30 at baseline were prospectively enrolled and underwent a single- (N=26) or two-level (N=16) PLF utilizing the novel BGS. 38/42 (90.5%) and 32/42 (76.2%) subjects attended 12- and 24-month follow-ups, respectively. OUTCOME MEASURES ODI, SF-36v2 PCS, SF-36v2 MCS, back and leg pain. METHODS Data was obtained preoperatively and at 1.5, 3, 6, 12, and 24 months. Radiographic studies were assessed by an independent core lab for evidence of bridging bone and lack of segmental angular ( RESULTS The two-year fusion rate for the novel BGS was 32/37 (86.5%) compared to the literature average of 76% (range 40%-100%) for ICBG. The fusion rate was 90.9% (20/22) in single- and 80% (12/15) in 2-level PLF (p=0.377). While ODI improved in both groups, the improvement was larger in single- than in 2-level subjects (p=0.058). At 24 months, the improvement in ODI was 33.5 and 25.9 in single- and 2-level subjects, respectively. There was a tendency for greater improvements at 24 months in single-level compared to 2-level PLF in SF36 PCS (15.4 vs 12.5) and SF36MCS (7.9 vs 5.6), but these differences did not reach statistical significance. Improvements in pain at back (4.8 vs 4.6) and pain at leg (4.8 vs 4.3) were similar in single- and 2-level surgeries. One secondary surgery was performed at 3 months postoperatively for a symptomatic screw in single-level subject. No product-related treatment complications were reported. CONCLUSIONS Two-level PLF is associated with poorer ODI but similar pain outcomes compared to single-level PLF. OSTEOAMP is safe and effective for use in posterolateral spinal fusion as evidenced by fusion rates higher than for ICBG, good clinical outcomes, and freedom from serious product-related complications. FDA DEVICE/DRUG STATUS OSTEOAMP® is compliant to 21 CFR 1271 and is regulated as a 361 HCT/P.

BackgroundRigid interspinous process fixation (ISPF) has received consideration as an efficient, minimally disruptive technique in supporting lumbar interbody fusion. However, despite advantageous intraoperative utility, limited evidence exists characterizing midterm to long-term clinical outcomes with ISPF. The objective of this multicenter study was to prospectively assess patients receiving single-level anterior (ALIF) or lateral (LLIF) lumbar interbody fusion with adjunctive ISPF.MethodsThis was a prospective, randomized, multicenter (11 investigators), noninferiority trial. All patients received single-level ALIF or LLIF with supplemental ISPF (n = 66) or pedicle screw fixation (PSF; n = 37) for degenerative disc disease and/or spondylolisthesis (grade ≤2). The randomization patient ratio was 2:1, ISPF/PSF. Perioperative and follow-up outcomes were collected (6 weeks, 3 months, 6 months, and 12 months).ResultsFor ISPF patients, mean posterior intraoperative outcomes were: blood loss, 70.9 mL; operating time, 52.2 minutes; incision length, 5.5 cm; and fluoroscopic imaging time, 10.4 seconds. Statistically significant improvement in patient Oswestry Disability Index scores were achieved by just 6 weeks after operation (P

Background Patients with large defects in the annulus fibrosus following lumbar discectomy have high rates of symptomatic reherniation. The Barricaid annular closure device provides durable occlusion of the annular defect and has been shown to significantly lower the risk of symptomatic reherniation in a large European randomized trial. However, the performance of the Barricaid device in a United States (US) population has not been previously reported. Design and methods This is a historically controlled post-market multicenter study to determine the safety and efficacy of the Barricaid device when used in addition to primary lumbar discectomy in a US population. A total of 75 patients with large annular defects will receive the Barricaid device following lumbar discectomy at up to 25 sites in the US and will return for clinical and imaging follow-up at 4 weeks, 3 months, and 1 year. Trial oversight will be provided by a data safety monitoring board and imaging studies will be read by an independent imaging core laboratory. Patients treated with the Barricaid device in a previous European randomized trial with comparable eligibility criteria, surgical procedures, and outcome measures will serve as historical controls. Main outcomes will include back pain severity, leg pain severity, Oswestry Disability Index, health utility on the EuroQol-5 Dimension questionnaire, complications, symptomatic reherniation, and reoperation. Propensity score adjustment using inverse probability of treatment weighting will be used to adjust for differences in baseline patient characteristics between the US trial participants and European historical controls. Ethics and dissemination This study was approved by a central institutional review board. The study results of this trial will be widely disseminated at conference proceedings and published in peer-reviewed journals. The outcomes of this study will have important clinical and economic implications for all stakeholders involved in treating patients with lumbar discectomy in the US. Study registration ClinicalTrials.gov (https://clinicaltrials.gov): NCT03986580. Level of evidence 3.

Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is an osteoinductive protein. However, soft-tissue edema adjacent to the site of rhBMP-2 implantation has been reported. This animal study was designed to examine soft-tissue edema associated with increasing rhBMP-2 doses with implantation on an absorbable collagen sponge (ACS) and with injection directly into muscle. Methods: Thirty-six Lewis rats received intramuscular implantation of rhBMP-2 on an ACS (Part I) or intramuscular injection of rhBMP-2 solution (Part II). Part-I sites received rhBMP-2/ACS at doses of 0 μg, 30 μg (normal), 129 μg (mid), or 450 μg (high). Part-II sites received rhBMP-2/ACS or rhBMP-2 intramuscular injection at doses of 10 μg (normal) or 150 μg (mid). A previous rat model showed 10 μg to be 100% effective at inducing osseous spinal fusion. In our study, T2-weighted magnetic resonance imaging (MRI) was performed at two and seven days to assess edema volume, and statistical comparisons were carried out with analysis of variance (ANOVA). Cellular response, vascularity, and ossification were examined histologically. Results: Quantitative MRI demonstrated similar peri-implant edema volumes in the control (buffer on an ACS) and normal-dose rhBMP-2 groups. Higher doses resulted in increased edema volume. Edema decreased significantly from two to seven days. Similar capillary densities were observed in all rhBMP-2 groups at two days, and there was dose-dependent increased ossification at seven days. Compared with the rhBMP-2 injection, implantation of the rhBMP-2/ACS resulted in increased edema. This edematous response was transient in all groups. Minimal or no ossification occurred after the rhBMP-2 injections. Conclusions: Transient peri-implant soft-tissue edema occurred in a dose-dependent manner following implantation of rhBMP-2/ACS in this rat model. The normal dose of rhBMP-2/ACS produced edema similar to that in the controls. Finally, rhBMP-2 solutions injected directly into muscle resulted in minimal soft-tissue edema. Clinical Relevance: This animal study demonstrates a dose-dependent effect of rhBMP-2 on peri-implant soft-tissue edema. Even though the response is transient, these data show the importance of using an appropriate rhBMP-2 dose to limit local soft-tissue edema. Controlled studies are needed to examine the appropriate rhBMP-2 dose for various clinical applications.

STUDY DESIGN: A retrospective study measuring postoperative serum titanium levels in patients with titanium alloy spinal instrumentation. OBJECTIVE: To determine serum titanium levels in patients after instrumented spinal arthrodesis with implants composed of titanium alloy and to identify potential factors responsible for any increase in ion levels. SUMMARY OF BACKGROUND DATA: Previous studies have documented localized metal debris in the tissues surrounding spinal instrumentation. Systemic distribution of metal debris has also been demonstrated by measuring elevated serum metal ion levels in patients with titanium spinal implants; however, no studies exist on the impact of instrumentation characteristics on serum ion levels. METHODS: Serum titanium concentrations were measured in 30 patients with titanium spinal instrumentation at a mean 26 months after surgery and compared with a control group without metallic implants. Comparisons were made regarding serum titanium levels with respect to specific instrumentation characteristics such as number of pedicle screws used, and the presence of cross connectors or titanium interbody devices. RESULTS.: Serum titanium levels were significantly higher in patients with titanium spinal implants (mean, 2.6 microg/L) when compared with controls (mean, 0.71 microg/L). Subjects who underwent an instrumented arthrodesis of only one spinal segment had decreased serum titanium levels when compared with those who were fused at 2 or more spinal segments (mean, 2.3 vs. 3.1 microg/L) and patients with 4 or less pedicle screws also had decreased serum titanium levels when compared with constructs of 6 to 8 pedicle screws (mean, 2.3 vs. 3.35 microg/L); however, both of these findings were not statistically significant. Patients without cross connectors had a slightly increased serum titanium level when compared with those with connectors (mean, 2.7 vs. 2.44 microg/L); however, this finding was also not statistically significant. Patients with titanium interbody devices had a statistically significant elevation in serum titanium levels when compared with those without (mean, 3.3 vs. 1.98 microg/L). CONCLUSION: Significantly higher serum titanium concentrations were observed in subjects with titanium spinal instrumentation when compared with controls. Continued research is necessary to examine the relationship between Ti interbody devices and cross connectors with regards to serum ion levels.

Postoperative toxic shock syndrome (PTSS) after orthopedic surgery is rare, but early recognition and prompt intervention are essential to minimize morbidity and potential mortality. The diagnosis should be considered in all postoperative patients presenting with fever, hypotension, and systemic illness. The treating surgeon must have not only knowledge of the clinical entity, but also an extremely high index of suspicion, because the diagnosis can be elusive with surgical wounds appearing deceptively benign. Treatment consists of antibiotics, surgical wound debridement, and, more importantly, aggressive supportive care with intravenous fluids and intensive care surveillance. To date, the literature contains relatively few case reports of PTSS after orthopedic procedures, with even fewer cases encountered after foot and ankle surgery. This report describes a patient who developed the rare complication of PTSS after an elective ganglion cyst excision from the ankle.