Lumbar Pedicle Subtraction Osteotomy (PSO): A Novel Surgical Technique for Correction of Sagittal and Coronal Imbalance Using Laterally Based Satellite Rods.

STUDY DESIGN: Operative video and supplemental manuscript. OBJECTIVE: To present a novel step-by-step approach to performing a lumbar pedicle subtraction osteotomy (PSO) using laterally based satellite rods. SUMMARY OF BACKGROUND DATA: Multi-rod constructs have demonstrated paramount for decreasing rates of pseudarthrosis after PSOs. Multi-rods constructs can be achieved using either "satellite" rods (rods not connected to the primary rods) and/or "accessory rods" (rods connected to the primary rods). METHODS: A step-by-step approach to performing a lumbar PSO using a laterally based satellite rod configuration is provided through a case example and surgical technique video. RESULTS: Lateral satellite rods can be particularly useful from a surgical perspective, as they provide temporary stabilization while the PSO is being performed, facilitate closure of the osteotomy site (symmetric and/or asymmetric), and serve as the final fixation rods across the PSO without needing to be exchanged. CONCLUSIONS: Use of laterally based satellite rods is a useful technique for lumbar PSOs, as they provide temporary stabilization while the PSO is being performed, facilitate closure of the osteotomy site, and serve as the final fixation rods across the PSO without needing to be exchanged.

Cervical Ossification of the Posterior Longitudinal Ligament (OPLL) in Native Hawaiians and/or Polynesians: A 3-year Retrospective Demographic and Descriptive Pilot Study.

Ossification of the posterior longitudinal ligament (OPLL) is a disease characterized by the replacement of the posterior longitudinal ligament with ectopic bone and cartilage. Historically, the disease was described as highly prevalent in Japanese and other Asian populations. However, recent studies suggest OPLL may have a higher prevalence in non-Asian communities than previously believed. To date, there are no demographic or epidemiologic studies examining OPLL in Native Hawaiian or Polynesian communities. The purpose of this study was to review the demographics and comorbidities of a cohort of patients with OPLL from the author's institution, designated as either Native Hawaiian and/or Polynesian (NHP) or Non-Native Hawaiian and/or Polynesian (NNHP). Demographic findings from this study were similar to previous literature demonstrating higher rates of OPLL in men and older patients with an average age of 56 years in the NHP group and 65 years in the NNHP group. There were no statistically significant differences in the rates of type II diabetes mellitus, coronary vascular disease, chronic kidney disease, or hypertension between NHP and NNHP groups. The NHP group exhibited statistically higher rates of obesity when compared to the NNHP group. Obesity's risk in the development or progression of OPLL in the NHP population has not been examined and requires additional investigation. This study serves as a beginning for further demographic and epidemiologic investigations into OPLL in Native Hawaiian and Polynesian communities to facilitate improved identification of those at risk and guide diagnosis and treatment of these patients.

Does the presence of the fibronectin-aggrecan complex predict outcomes from lumbar discectomy for disc herniation?

BACKGROUND CONTEXT: Protein biomarkers associated with lumbar disc disease have been studied as diagnostic indicators and therapeutic targets. Recently, a cartilage degradation product, the fibronectin-aggrecan complex (FAC) identified in the epidural space, has been shown to predict response to lumbar epidural steroid injection in patients with radiculopathy from herniated nucleus pulposus (HNP). PURPOSE: Determine the ability of FAC to predict response to microdiscectomy for patients with radiculopathy due to lumbar disc herniation STUDY DESIGN/SETTING: Single-center prospective consecutive cohort study. PATIENT SAMPLE: Patients with radiculopathy from HNP with concordant symptoms to MRI who underwent microdiscectomy. OUTCOMES MEASURES: Oswestry disability index (ODI) and visual analog scores (VAS) were noted at baseline and at 3-month follow-up. Primary outcome of clinical improvement was defined as patients with both a decrease in VAS of at least 3 points and ODI >20 points. METHODS: Intraoperative sampling was done via lavage of the excised fragment by ELISA for presence of FAC. Funding for the ELISA was provided by Cytonics, Inc. RESULTS: Seventy-five patients had full complement of data and were included in this analysis. At 3-month follow-up, 57 (76%) patents were "better." There was a statistically significant association of the presence of FAC and clinical improvement (p=.017) with an 85% positive predictive value. Receiver-operating-characteristic (ROC) curve plotting association of FAC and clinical improvement demonstrates an area under the curve (AUC) of 0.66±0.08 (p=.037). Subset analysis of those with weakness on physical examination (n=48) plotting the association of FAC and improvement shows AUC on ROC of 0.81±0.067 (p=.002). CONCLUSIONS: Patients who are "FAC+" are more likely to demonstrate clinical improvement following microdiscectomy. The data suggest that the inflammatory milieu plays a significant role regarding improvement in patients undergoing discectomy for radiculopathy in lumbar HNP, even in those with preoperative weakness. The FAC represents a potential target for treatment in HNP.

Retrograde ejaculation after anterior lumbar interbody fusion with and without bone morphogenetic protein-2 augmentation: a 10-year cohort controlled study.

BACKGROUND CONTEXT: Retrograde ejaculation (RE) is a complication of anterior lumbar interbody fusion (ALIF) techniques. Most commonly, this results from mechanical or inflammatory injury to the superior hypogastric plexus near the aortic bifurcation. Bone morphogenetic protein-2 (BMP-2) has been used in spinal fusions and has been associated with inflammatory and neuroinflammatory adverse reactions, which may contribute to RE development after anterior lumbar surgery. PURPOSE: While controlling for anterior approach technique, we compared the incidence of RE with and without rhBMP-2 exposure, in large, matched cohorts of patients after ALIF. STUDY DESIGN: Retrospective analysis of 10 years of prospectively gathered outcomes data on consecutive-patient cohorts having the same anterior exposure technique for ALIF with and without rhBMP-2 use. PATIENT SAMPLE: All male patients without baseline sexual incapacity and having ALIF for lumbar spondylosis or spondylolisthesis of the lowest one or two lumbar levels with and without rhBMP-2, from 2002 through 2011. OUTCOME MEASURES: Diagnosis of RE as a new finding after ALIF compared against BMP-2 exposure, comorbid conditions, and other urological complications after ALIF surgery. METHODS: From the comprehensive surgical database at a high volume, university practice, male subjects having ALIF at one (L5/S1) or two levels (L4/5, L5/S1) from 2002 to 2011 were identified. Baseline comorbid factors, postoperative urinary catheter/retention events, and RE events were recorded and comparative incidence compared. RESULTS: There were four consecutive-patient cohorts identified: one before rhBMP-2 use was adopted (n=174), two cohorts in which BMP-2 use was routine (n=88 and n=151), and one final cohort after BMP-2 use was discontinued from routine use (n=59). The cohorts with and without BMP-2 exposure were closely comparable for age, approach, levels of surgery, comorbid factors affecting RE. Of 239 patients with ALIF and exposure to BMP-2, RE was diagnosed in 15 subjects (6.3%), compared with an RE diagnosis rate of two of 233 control patients without BMP-2 exposure (0.9%; p=.0012). Urinary retention after bladder catheter removal was also more frequently observed in patients exposed to BMP-2 (9.7%) compared with control patients (4.6%; p=.043). Of the baseline comorbid factors, medical or surgical treatment for prostatic hypertrophy disease was associated with an increased risk of RE in the BMP-2 patients (p=.034). CONCLUSIONS: This study confirms previous reports of a higher rate of RE in ALIF procedures using rhBMP-2 and an open anterior approach to the spine. This effect may be associated with an increased risk of postoperative urinary retention after BMP-2 exposure. The magnitude of the RE effect may be increased with concomitant prostatic disease treatments.

Retrograde ejaculation after anterior lumbar interbody fusion using rhBMP-2: a cohort controlled study.

BACKGROUND CONTEXT: The commercially available growth factor recombinant bone morphogenic protein-2 (rhBMP-2) used in spinal fusion has been associated with numerous adverse reactions, including inflammatory reactions in soft tissue, heterotopic bone formation, radiculitis, osteolysis, and cage or graft subsidence. The original Food and Drug Administration Summary of anterior lumbar interbody fusion (ALIF) reported 12 retrograde ejaculation (RE) events (8%) in the rhBMP-2 groups compared with (1.4%) in the control group. It had been debated whether this finding was related to rhBMP-2 use. PURPOSE: To compare the incidence of RE after ALIF in patients with and without rhBMP-2 use. STUDY DESIGN: Retrospective analysis of prospectively gathered outcomes data on consecutive subjects having ALIF with and without rhBMP-2 use. PATIENT SAMPLE: Male patients with lumbar spondylosis or spondylolisthesis having ALIF of the lowest one or two lumbar levels with and without rhBMP-2. OUTCOME MEASURE: Report of RE as a new finding after ALIF. METHODS: From the comprehensive outcome database at a high-volume university practice, male subjects having ALIF for one- (L5/S1) or two-level (L4/L5, L5/S1) lumbar fusion were identified. Retrograde ejaculation events were recorded and comparative incidence compared. RESULTS: The two groups were comparable for age and additional procedures performed. There were 69 L5/S1 ALIFs performed with rhBMP-2 and 174 ALIFs performed without rhBMP-2 during the study period. Of those, 24 and 64 were two-level ALIFs performed with and without rhBMP-2, respectively. There were five RE events (7.2%) reported in the rhBMP-2 group and 1 (0.6%) in the control group. Comparing single-level L5/S1 ALIF, there was a 6.7% and 0% rate of RE in the rhBMP-2 versus control groups, respectively. At 1 year after surgery, three of six affected subjects reported resolution of the RE. CONCLUSION: This study confirms previous reports of a higher rate of RE in ALIF procedures using rhBMP-2. This may be an important consideration in subjects concerned with sterility after surgery.