OBJECTIVEA common cause of peroneal neuropathy is compression near the fibular head. Studies demonstrate excellent outcomes after decompression but include few cases (range 15–60 patients). Consequently, attempts to define predictors of good outcomes are limited. Here, the authors combine their institutional outcomes with those in the literature to identify predictors of good outcomes after peroneal nerve decompression.METHODSThe authors searched their institutional electronic medical records to identify all peroneal nerve decompressions performed in the period between December 1, 2012, and September 30, 2016, and created an IRB-approved database. They also conducted a MEDLINE and literature search to identify articles discussing surgical decompression. All data were combined by meta-analysis to identify the factors associated with a favorable outcome, which was defined as improvement in preoperative symptoms. Patients were analyzed in the aggregate and by presentation (pain, paresthesias, weakness, foot drop). The factors evaluated included age, sex, body mass index, diabetes, smoking status, previous knee or lumbar spine surgery, preoperative symptom duration, and etiology. A meta-analysis was completed for any factor evaluated in at least three data sets.RESULTSTwenty-one institutional cases had sufficient data for review. The follow-up among this group was long: median 29 months, range 12–52 months. On aggregate analysis of the data, only diabetes was significantly associated with unfavorable outcomes after decompression (p = 0.05). A trend toward worse outcomes was seen in smokers presenting with pain (p = 0.06). Outcomes were not affected by presentation.An additional 115 cases in the literature had extractable data for meta-analysis, and other associations were seen. Preoperative symptom duration longer than 12 months was associated with unfavorable outcomes (OR 0.23, 95% CI 0.08–0.65). Patients presenting with paresthesias or hypesthesia demonstrated a trend toward more unfavorable outcomes when operated on more than 6 months after symptom onset (OR 0.37, 95% CI 0.13–1.06). Even after the meta-analysis, outcomes did not vary with an advanced age (OR 0.70, 95% CI 0.24–1.98) or with patient sex (OR 1.13, 95% CI 0.42–3.06).CONCLUSIONSThe authors provide their institutional data in combination with published data regarding outcomes after peroneal nerve decompression. Outcomes are typically favorable and generally unaffected by the type of symptoms preoperatively, especially if the patient is nondiabetic and preoperative symptom duration is less than 12 months. Patients with paresthesias may benefit from surgery within 6 months after onset. Smoking may adversely affect surgical outcomes. Finally, an advanced age does not adversely affect outcomes, and older patients should be considered for surgery.

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BACKGROUND Although advances in implant materials, such as polyetheretherketone (PEEK), have been developed aimed to improve outcome after anterior cervical discectomy and fusion (ACDF), it is essential to confirm whether these changes translate into clinically important sustained benefits. OBJECTIVE To compare the radiographic and clinical outcomes of patients undergoing up to 3-level ACDF with PEEK vs structural allograft implants. METHODS In this cohort study, radiographic and symptomatic nonunion rates were compared in consecutive patients who underwent 1 to 3 level ACDF with allograft or PEEK implant. Prospectively collected clinical data and patient-reported outcome (PRO) scores were compared between the allograft and PEEK groups. Regression analysis was performed to determine the predictors of nonunion. RESULTS In total, 194 of 404 patients met the inclusion criteria (79% allograft vs 21% PEEK). Preoperative demographic variables were comparable between the 2 groups except for age. The rate of radiographic nonunion was higher with PEEK implants (39% vs 27%, P = .0035). However, a higher proportion of nonunion in the allograft cohort required posterior instrumentation (14% vs 3%, P = .039). Patients with multilevel procedures and PEEK implants had up to 5.8 times the risk of radiographic nonunion, whereas younger patients, active smokers, and multilevel procedures were at higher risk of symptomatic nonunion. CONCLUSION Along with implant material, factors such as younger age, active smoking status, and the number of operated levels were independent predictors of fusion failure. Given the impact of nonunion on PRO, perioperative optimization of modifiable factors and surgical planning are essential to ensure a successful outcome.

Background: Lateral lumbar interbody fusion (LLIF) affords a wide operative corridor to allow for a large interbody cage implantation for segmental reconstruction. There is a paucity of data describing segmental lordosis (SL) achieved with lordotic implants of varying angles. Here we compare changes in SL and lumbar lordosis (LL) after implantation of 68, 108, and 128 cages.Methods: We retrospectively reviewed LLIF cases over a 5.5-year period. We derived SL and LL using the standard cobb angle measurement from a standing lateral radiograph. We analyzed mean changes in SL and LL over time using the linear mixed effect model to estimate these longitudinal changes.Results: The most frequently treated level was L3-4, followed by L4-5. Significant increases in mean SL were found at each follow-up time point for all the cohorts. In an intercohort comparison, the mean changes in SL at immediate postoperative and last follow-up were significantly greater in the 108 cohort than 68 ([7.48 versus 3.18, P ¼ .004], [6.18 versus 2.38, P ¼ .025] respectively). The 128 cohort had higher mean change in SL at last follow-up than the 68 cohort (5.98 versus 2.38, P ¼ .022). There was no difference in mean change in SL between the 108 and 128 cohorts. No difference in overall mean LL over time was found. In terms of mean change in LL, no difference was observed except at immediate and 6month postoperative in the 108 cohort ([9.68, P ¼ .001], [8.5, P ¼ .003] respectively). By comparing mean change in LL, no difference existed except between the 108 and 68 immediately after surgery (9.68 versus 0.28, P ¼ .006).Conclusions: LLIF cages significantly improve SL at the index level. However, this increase in SL is greater for 108 and 128 cages than the standard 68 cage. Use of 108 cages also resulted in overall improved LL than 68 cages.Level of Evidence: 3. Clinical Relevance: Lateral lumbar interbody fusion.

Mouse models are unique for studying molecular mechanisms of neurotrauma because of the availability of various genetic modified mouse lines. For spinal cord injury (SCI) research, producing an accurate injury is essential, but it is challenging because of the small size of the mouse cord and the inconsistency of injury production. The Louisville Injury System Apparatus (LISA) impactor has been shown to produce precise contusive SCI in adult rats. Here, we examined whether the LISA impactor could be used to create accurate and graded contusive SCIs in mice. Adult C57BL/6 mice received a T10 laminectomy followed by 0.2, 0.5, and 0.8 mm displacement injuries, guided by a laser, from the dorsal surface of the spinal cord using the LISA impactor. Basso Mouse Scale (BMS), grid-walking, TreadScan, and Hargreaves analyses were performed for up to 6 weeks post-injury. All mice were euthanized at the 7th week, and the spinal cords were collected for histological analysis. Our results showed that the LISA impactor produced accurate and consistent contusive SCIs corresponding to mild, moderate, and severe injuries to the cord. The degree of injury severities could be readily determined by the BMS locomotor, grid-walking, and TreadScan gait assessments. The cutaneous hyperalgesia threshold was also significantly increased as the injury severity increased. The terminal lesion area and the spared white matter of the injury epicenter were strongly correlated with the injury severities. We conclude that the LISA device, guided by a laser, can produce reliable graded contusive SCIs in mice, resulting in severity-dependent behavioral and histopathological deficits.

BACKGROUND:Nonunion remains a concern in multilevel anterior cervical discectomy and fusion (ACDF), yet there are limited data on nonunion after 4 to 5-level ACDF. In fact, the largest series on 4-level or 5-level ACDF focused specifically on the swallowing outcomes.OBJECTIVE:To assess nonunion after 4 to 5-level ACDF.METHODS:Forty-one patients treated with 4 to 5-level ACDF with minimum of 12-month radiographic follow-up were retrospectively reviewed. Nonunion was found in 25 patients (61%) and 42 levels (25%) and complete fusion in 16 (39%) patients and 126 levels (75%). The 2 groups were further compared.RESULTS:One-level nonunion was by far the most common pattern compared with multilevel nonunion. Nonunion occurred more frequently at the caudal than the cranial or middle segments (P < .0001). There were significantly more subsidence (P < .0001) and screw fractures/pullouts (P < .0001) in the nonunion compared with the fusion group. The symptomatic patients were significantly younger than the asymptomatic patients (P = .044). The symptomatic levels were significantly more than asymptomatic levels (P = .048). Equal proportion of patients implanted with allograft and polyetheretherketone had nonunion. However, there were markedly more nonunion than fused levels with allograft and more fused than nonunion levels with polyetheretherketone (P = .023). The reoperation rate was 24.4% and mostly due to nonunion. There were no reoperations within 90 days of the primary surgery.CONCLUSION:The nonunion rate for 4-level and 5-level ACDF may be higher than previously reported. Symptomatic nonunion remains a major reason for reoperation after multilevel ACDF. Baseline characteristics that negatively affect fusion may be obviated by careful patient selection.

After undergoing multilevel thoracic and lumbar laminectomies with subarachnoid-to-subarachnoid spinal shunt, the patient's spasticity was finally brought under control with adequate daily baclofen infusion. This case demonstrates a creative way to address ITB catheter failure before considering other measures, such as neuroablative procedures (e.g., rhizotomy, myelotomy). This case reinforces the recommendation that ablative procedures, which have far greater complications, should be reserved for patients who have failed medical or other nonablative therapies.

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