Survival Outcomes and Factors Associated with Revision Surgery for Metastatic Disease of the Spine.

STUDY DESIGN: Retrospective review of a prospective database. OBJECTIVE: Certain subset of patients undergoing surgical treatment for spinal metastasis will require a revision surgery in their disease course; however, factors predictive of revision surgery and survival outcomes are largely unknown. The goal of this study is to report on survival outcomes as well as factors predictive of revision surgery in this unique patient population. METHODS: A total of 55 patients who met the inclusion criteria were included from January 2010 to December 2015. Twelve (22%) of these patients underwent a revision surgery. Patient and tumor characteristics were summarized and survival outcomes were evaluated using Kaplan-Meier methods and Cox proportional hazards regression. RESULTS: Both the revision and the nonrevision groups were similarly matched with respect to spine disease burden, neurological status at time of initial presentation, primary malignancy types, and the use of adjuvant treatment modalities. Tumor progression (66.7%) was the most common reason for necessitating a revision followed by nonunion (16.7%), wound dehiscence (8.3%), and construct failure (8.3%). Following multivariate model selection procedures, smokers were found to have 3.5 times increased odds of undergoing revision compared to nonsmokers (p = 0.05). Analysis of survival curves showed that the median survival in the revision group was 3.0 years (95% CI: 1.5, 4.1), while the median survival in the nonrevision group was 1.5 years (95% CI: 1.1, 2.3; log-rank test, p = 0.105). CONCLUSION: Despite aggressive treatment, tumor progression is the most common reason for revision surgery. Smoking is an independent risk factor for revision. Revision surgery should be considered in patients when indicated as it does not appear to detrimentally affect survival.

Is there value in retrospective 90-day bundle payment models for shoulder arthroplasty procedures?

BACKGROUND: The Centers for Medicare & Medicaid Services Bundled Payments for Care Improvement (BPCI) initiative was implemented as part of the Affordable Care Act. We implemented a retrospective payment model 2 for a 90-day total shoulder arthroplasty (TSA) episode to assess the value of TSA BPCI at our private practice. METHODS: Expenditures and postacute event rates of 132 fee-for-service (FFS) patients who underwent a TSA operation between 2009 and 2012 were compared with 333 BPCI patients who had a TSA operation in 2015. The 90-day postacute events included an inpatient rehabilitation facility (IRF), skilled nursing facility (SNF), and home health (HH) admissions and readmissions. Expenditures were converted to 2016 dollars using the Consumer Price Index. Wilcoxon tests and multivariate generalized estimating equation were used to assess independent cost-drivers. RESULTS: The median FFS expenditure was $21,157 (interquartile range, $16,894-$30,748) compared with $17,894 (interquartile range, $15,796-$20,894) for BPCI (P < .0001). The BPCI patients had significantly lower rates of SNF admissions (34% FFS vs. 16% BPCI; P < .001), IRF admissions (3% FFS vs. 0.6% BPCI; P = .05), HH utilization (49% FFS vs. 41% BPCI; P = .05), and readmissions (14% FFS vs. 7% BPCI; P = .01). After controlling for postacute events in the multivariate regression model, we found BPCI had a 4% decrease in expenditures (P = .08). All postacute events were independently associated with higher expenditures. CONCLUSIONS: Our private practice implemented cost-containment practices, including clinical guidelines, patient navigators, and a BPCI management team. IRF and SNF utilization and the 90-day readmission rate significantly decreased. As a result, we were able to control the postacute spending, which resulted in decreased costs of performing TSA surgery.

Adjacent segment degeneration following ProDisc-C total disc replacement (TDR) and anterior cervical discectomy and fusion (ACDF): does surgeon bias effect radiographic interpretation?

PURPOSE: Many investigators have reported the financial conflicts of interest (COI), which could result in potential bias in the reporting of outcomes for patients undergoing total disc replacement (TDR) rather than anterior cervical discectomy and fusion (ACDF). This bias may be subconsciously introduced by the investigator in a non-blinded radiographic review. The purpose of this study was to determine if bias was present when a group of spine specialists rated adjacent segment degeneration (ASD) following cervical TDR or ACDF. METHODS: Potential bias in the assessment of ASD was evaluated through the reviews of cervical radiographs (pre- and 6 years post-operative) from patients participating in the ProDisc-C FDA trial (ProDisc-C IDE #G030059). The index level was blinded on all radiographs during the first review, but unblinded in the second. Five reviewers (a radiologist, two non-TDR surgeons, and two TDR surgeons), two of whom had a COI with the ProDisc-C trial sponsor, assessed ASD on a three point scale: yes, no, or unable to assess. Intra- and inter-rater reliabilities between all raters were assessed by the Kappa statistic. RESULTS: The intra-rater reliability between reviews was substantial, indicating little to no bias in assessing ASD development/progression. The Kappa statistics were 0.580 and 0.644 for the TDR surgeons (p < 0.0001), 0.718 and 0.572 for the non-TDR surgeons (p < 0.0001), and 0.642 for the radiologist (p < 0.0001). Inter-rater reliability for the blinded review ranged from 0.316 to 0.607 (p < 0.0001) and from 0.221 to 0.644 (p < 0.0001) for the unblinded review. CONCLUSIONS: The knowledge of the surgical procedure performed did not bias the assessment of ASD.

Management of symptomatic lumbar degenerative disk disease.

Symptomatic lumbar degenerative disk disease, or discogenic back pain, is difficult to treat. Patients often report transverse low back pain that radiates into the sacroiliac joints. Radicular or claudicatory symptoms are generally absent unless there is concomitant nerve compression. Physical examination findings are often unremarkable. Radiographic examination may reveal disk space narrowing, end-plate sclerosis, or vacuum phenomenon in the disk; magnetic resonance imaging is useful for revealing hydration of the disk, annular bulging, or lumbar spine end-plate (Modic) changes in the adjacent vertebral bodies. The use of diskography as a confirmatory study remains controversial. Recent prospective, randomized trials and meta-analyses of the literature have helped expand what is known about degenerative disk disease. In most patients with low back pain, symptoms resolve without surgical intervention; physical therapy and nonsteroidal anti-inflammatory drugs are the cornerstones of nonsurgical treatment. Intradiskal electrothermal treatment has not been shown to be effective, and arthrodesis remains controversial for the treatment of discogenic back pain. Nucleus replacement and motion-sparing technology are too new to have demonstrated long-term data regarding their efficacy.

Cauda equina syndrome.

Cauda equina syndrome is a relatively uncommon condition typically associated with a large, space-occupying lesion within the canal of the lumbosacral spine. The syndrome is characterized by varying patterns of low back pain, sciatica, lower extremity sensorimotor loss, and bowel and bladder dysfunction. The pathophysiology remains unclear but may be related to damage to the nerve roots composing the cauda equina from direct mechanical compression and venous congestion or ischemia. Early diagnosis is often challenging because the initial signs and symptoms frequently are subtle. Classically, the full-blown syndrome includes urinary retention, saddle anesthesia of the perineum, bilateral lower extremity pain, numbness, and weakness. Decreased rectal tone may be a relatively late finding. Early signs and symptoms of a developing postoperative cauda equina syndrome are often attributed to common postoperative findings. Therefore, a high index of suspicion is necessary in the postoperative spine patient with back and/or leg pain refractory to analgesia, especially in the setting of urinary retention. Regardless of the setting, when cauda equina syndrome is diagnosed, the treatment is urgent surgical decompression of the spinal canal.

Two-Year Results of a Randomized Controlled Clinical Trial Comparing ProDisc-C and Anterior Cervical Discectomy and Fusion.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is a well-accepted procedure for the treatment of cervical radiculopathy. Hilibrand et al. reported that adjacent segment disease is known to occur at a rate of 2.9% per year after cervical fusion. Developers of cervical disc replacements postulate that maintaining more normal motion may reduce the rate of adjacent segment disease. The purpose of this study was to compare the 2-year efficacy and safety of ACDF and cervical total disc replacement surgery. METHODS: Eighty-seven patients from 2 sites of this 13 multicenter trial were randomized to treatment with either ACDF or cervical disc replacement surgery with the ProDisc-C (Synthes, Inc., West Chester, Pennsylvania) implant. Patient outcomes were assessed via neck disability index (NDI), visual analog pain scale (VAS), and health survey SF-36 (QualityMetric, Lincoln, Rhode Island). Forty-three patients were treated with ACDF using allograft and plating, and 44 were treated with cervical disc replacement. The average age was 44 (23 to 61) years. All surgical procedures were single level. RESULTS: At all measured time points, both groups showed statistically significant improvement over their preoperative baseline with regard to NDI, VAS arm and neck pain levels, SF-36 mental composite score (MCS), and physical composite score (PCS) (P < .05). At 24 months, the disc replacement group showed results equivalent to the ACDF group with regard to NDI, VAS arm and neck pain, and SF-36 MCS. At 24 months, the disc replacement group showed significantly greater improvement in SF- 36 PCS as compared to the ACDF group (P = .0359). Of note, there was a trend toward greater patient satisfaction in the disc replacement group as compared to the ACDF group (83% versus 71%, P = .144). CONCLUSIONS: This study indicates that the tested disc replacement device achieves 2-year results ranging from equivalent to superior in comparison to ACDF in the treatment of symptomatic cervical disc disease. Long-term maintenance of these results has not yet been determined.

Anatomic mapping and evaluation of the esophagus in relation to the cervical vertebral body.

The relationship of the esophagus to the cervical vertebral body (CVB), disc space and longus colli (LC) muscles, to our knowledge, has not been previously studied. The purpose of this study was to quantify the relationship of the esophagus to the CVB, disc space and LC. 30 patients were selected for a retrospective review of computed tomography (CT) scans. Measurements between the esophagus and the C5, C6, and C7 vertebral bodies as well as the C5/6 and C6/7 disc spaces were performed in the midline, 3 mm right and left of midline, and at the edge of the LC on both sides. The closest distance of the esophagus to the CVB and disc space occurs at the midline (range 1.02-1.31 mm at each level). The furthest distance occurred at the edge of the right LC (range 2.67-3.30 mm at each level). The mean distance from the edge of the right LC to the midline was significantly greater (P < 0.01) than mean distance from the edge of the left LC to the midline. No statistical significant differences were observed when comparing measurements at the individual vertebral bodies and disc spaces. The results of the study demonstrate that the esophagus lies in closest proximity to the CVB and disc space in the midline. A larger potential space exists between the esophagus and the CVB and disc space at the edge of the LC. These results may provide insight into a potential cause of post-operative dysphagia. Furthermore, it may help guide the future design of cervical plates to better utilize the potential space between the esophagus and the CVB and disc space at the edge of the LC.

Use of computed tomography to predict failure of nonoperative treatment of unilateral facet fractures of the cervical spine.

STUDY DESIGN: Retrospective review. OBJECTIVES: To determine whether radiographic measurements derived from standard computed tomography (CT) evaluation can be used to predict failure of nonoperative treatment in patients with unilateral facet fractures. SUMMARY OF BACKGROUND DATA: There is no consensus regarding treatment of unilateral cervical spine facet fractures. Management of this injury is based primarily on the presence of neurologic deficits and the degree of perceived spinal instability. CT-based criteria for predicting failure of nonoperative treatment in this patient population have not been examined. METHODS: Initial CT scans of all patients with unilateral cervical facet fractures were reviewed. Direct measurements included height and width of the facet fracture fragment, fracture displacement, and angulation. Calculated data included percent height and width of the fracture fragment based on the height and width of the contralateral intact facet. RESULTS: A total of 24 patients with 26 unilateral facet fractures were identified. Five patients with 5 facet fractures failed nonoperative management and required delayed surgical stabilization. Comparing patients successfully treated nonoperatively to those failing nonoperative management, a significant difference was found in absolute height of the fracture fragment (P = 0.0002), articular fracture height (P = 0.008), and height of the fracture fragment expressed as a percentage of the contralateral intact lateral mass (P = 0.026). CONCLUSION: The only significant risk factors identified for failure of nonoperative treatment were craniocaudal height of the fracture fragment and relative height of the fracture fragment expressed as a percentage of the intact lateral mass. This study suggests that patients with unilateral cervical facet fractures involving >40% of the absolute height of the intact lateral mass or an absolute height >1 cm are at increased risk for failure of nonoperative treatment. Failure of nonoperative treatment was not observed in any patient with a fracture involving less than 40% of the height of the lateral mass or an absolute height <1 cm.

Computed tomography evaluation of superior-segment facet-joint violation after pedicle instrumentation of the lumbar spine with a midline surgical approach.

STUDY DESIGN: Retrospective study. OBJECTIVES: To determine the frequency of pedicle screw violation of superior nonfused facet joints adjacent to the most cephalad pedicle screws after a midline approach for lumbar fusion. SUMMARY OF BACKGROUND DATA: Facet-joint violations have been evaluated in patients undergoing lumbar pedicle screw instrumentation and fusion with a Wiltse muscle-splitting approach, but not via the more common midline approach. METHODS: Between 1995 and 2003, 204 patients underwent this procedure. Computed tomography scans (within 1 year postsurgery) were evaluated independently for superior facet-joint violation. chi tests were used to examine bivariate associations of superior level facet-joint violation, patient age, construct level, diagnosis, and revision status for significance (P < or = 0.05). RESULTS: Superior-level facet-joint violation occurred in 24% of patients and 15% of screws, twice as often on the left side (P = 0.0396) than on the right, more frequently in single than in multiple-level procedures (P < 0.0001), and most frequently with the most cephalad screws at L5 (48%). We found no significant associations between violation rates and other designated parameters. CONCLUSION: The left side, single-level fusion, and most cephalad pedicle screws at L5 are targets for interventions to reduce pedicle violations in this procedure.