Trends in Spinal Surgery Performed by American Board of Orthopaedic Surgery Part II Candidates (2008 to 2017)

Comparative Analysis of the 3 Cervical Vertebral Bone Quality (C-VBQ) Score Methodologies and Their Correlations to the Lumbar Vertebral Bone Quality (VBQ) Score

OBJECTIVE

Common complications after spinal fusion, such as pseudoarthrosis, cage subsidence, or instrumentation failure, are affected by patients' bone quality. The cervical-vertebral bone quality (C-VBQ) score, a magnetic resonance imaging (MRI)-based adaption of the lumbar vertebral bone quality (VBQ) score, was developed by 3 separate research groups simultaneously to evaluate bone quality in cervical spinal fusion patients. We present the first analysis comparing these scoring methods to the well-validated VBQ score.

METHODS

A retrospective analysis of data for consecutive patients who underwent spine surgery at a single institution was completed. The VBQ score was calculated using the Ehresman et al.

METHOD

The C-VBQ scores, named according to placement of the region of interest within the cerebral spinal fluid, were calculated separately using the methods of Soliman et al. (C2-VBQ), Razzouk et al. (C5-VBQ), and Huang et al. (T1-VBQ). Linear regression models were utilized to evaluate correlations to the VBQ score.

RESULTS

A total of 105 patients were identified (mean age, 57.0 ± 11.9 years; women, 50.5%). Mean scores were C2-VBQ, 2.37 ± 0.55; C5-VBQ, 2.36 ± 0.61; and T1-VBQ, 2.64 ± 0.68. The C-VBQ scores for the C2 level were significantly higher than those for the C3-C6 levels (3.18 ± 0.96 vs. 2.63 ± 0.77, P < 0.001), whereas the C7 level was found to have significantly lower C-VBQ scores (2.42 ± 0.78 vs. 2.63 ± 0.77, P = 0.04). The C2-VBQ (r = 0.63) score had the strongest correlation to the VBQ score, compared to C5-VBQ (r = 0.41) and T1-VBQ (r = 0.43) (P < 0.001).

CONCLUSIONS

This study demonstrates that the C2-VBQ had the strongest correlation to the lumbar VBQ score among all C-VBQ scores.

The Surgical Learning Curve for Cervical Disk Replacement

STUDY DESIGN

Retrospective study.

OBJECTIVE

To characterize an experienced single surgeon learning curve for cervical disk replacement (CDR).

SUMMARY OF BACKGROUND DATA

A single surgeon learning curve has not been established for CDR.

METHODS

Patients undergoing CDR were included. The cumulative sum of operative time was utilized to separate cases into 3 phases: learning, practicing, and mastery. Demographics, perioperative characteristics, complications, patient-reported outcomes (PROs), and radiographic outcomes were collected preoperatively and up to 1 year postoperatively. PROs included Patient-reported Outcomes Measurement Information System Physical Function, 12-item Short Form-12 Physical Component Score, 12-item Short Form-12 Mental Component Score, visual analog scale (VAS) arm, VAS neck, Neck Disability Index. Radiographic outcomes included segmental angle/segmental range of motion/C2-C7 range of motion. Minimum clinically important difference achievement was determined through a comparison of previously established values.

RESULTS

A total of 173 patients were identified, with 14 patients in the learning phase, 42 patients in the practicing phase, and 117 patients in the mastery phase. Mean operative time and mean postoperative day 0 narcotic consumption were significantly higher in the learning phase. The preoperative segmental angle was significantly lower for the learning phase, though these differences were eliminated at the final postoperative time point. Patients in the learning phase reported worse improvement to 6-week postoperative, final postoperative, and worse overall final postoperative VAS Arm scores compared with practicing and mastery phases.

CONCLUSIONS

For an experienced spine surgeon, the learning phase for CDR was estimated to span 14 patients. During this phase, patients demonstrated longer operative times, higher postoperative narcotic consumption, and worse postoperative VAS Arm scores. Radiographically, no postoperative differences were noted between different phases of mastery. This single surgeon learning curve demonstrates that CDR may be performed safely and with comparable outcomes by experienced spine surgeons despite decreased operative efficiency in the learning phase.

Calculating ex-ante Utilities From the Neck Disability Index Score: Quantifying the Value of Care For Cervical Spine Pathology

STUDY DESIGN

General population utility valuation study.

OBJECTIVE

To develop a technique for calculating utilities from the Neck Disability Index (NDI) score.

METHODS

We recruited a sample of 1200 adults from a market research panel. Using an online discrete choice experiment (DCE), participants rated 10 choice sets based on NDI health states. A multi-attribute utility function was estimated using a mixed multinomial-logit regression model (MIXL). The sample was partitioned into a training set used for model fitting and validation set used for model evaluation.

RESULTS

The regression model demonstrated good predictive performance on the validation set with an AUC of .77 (95% CI: .76-.78). The regression model was used to develop a utility scoring rubric for the NDI. Regression results also revealed that participants did not regard all NDI items as equally important. The rank order of importance was (in decreasing order): pain intensity = work; personal care = headache; concentration = sleeping; driving; recreation; lifting; and lastly reading.

CONCLUSIONS

This study provides a simple technique for converting the NDI score to utilities and quantify the relative importance of individual NDI items. The ability to evaluate quality-adjusted life-years using these utilities for cervical spine pain and disability could facilitate economic analysis and aid in allocation of healthcare resources.

Facet Distraction and Dysphagia: A Prospective Evaluation of This Common Postoperative Issue Following Anterior Cervical Spine Surgery

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Our primary study was to investigate whether the degree of postoperative facet and disk space distraction following anterior cervical discectomy and fusion (ACDF) affects the rate of postoperative dysphagia.

SUMMARY OF BACKGROUND DATA

Although ACDF is safe and well tolerated, postoperative dysphagia remains a common complication. Intervertebral disk space distraction is necessary in ACDF to visualize the operative field, prepare the endplates for fusion, and facilitate graft insertion. However, the degree of distraction tolerated, before onset of dysphagia, is not well characterized ACDF.

MATERIALS AND METHODS

A prospective cohort study was conducted of 70 patients who underwent ACDF between June 2018 and January 2019. Two independent reviewers measured all preoperative and postoperative radiographs measured for interfacet distraction distance and intervertebral distraction distance, with intrareviewer reproducibility measurements after one month. For multilevel surgery, the level with the greatest distraction was measured. Primary outcomes were numerical dysphagia (0-10), Eating Assessment Tool 10, and Dysphagia Symptom Questionnaire score collected at initial visit and two, six, 12, and 24 weeks postoperatively.

RESULTS

A total of 70 patients were prospectively enrolled, 59 of whom had adequate radiographs. An average of 1.71 (SD: 0.70) levels were included in the ACDF construct. Preoperatively, 13.4% of patients reported symptoms of dysphagia, which subsequently increased in the postoperative period at through 12 weeks postoperatively, before returning to baseline at 24 weeks. Intrareviewer and interreviewer reliability analysis demonstrated strong agreement. There was no relationship between interfacet distraction distance/intervertebral distraction distance and dysphagia prevalence, numerical rating, Eating Assessment Tool 10, or Dysphagia Symptom Questionnaire.

CONCLUSIONS

Patients who had an ACDF have an increased risk of dysphagia in the short term, however, this resolved without intervention by six months. Our data suggests increased facet and intervertebral disk distraction does not influence postoperative dysphagia rates.

LEVEL OF EVIDENCE

3.

Factors influencing the long-term outcomes of instrumentation surgery for degenerative lumbar spondylolisthesis: a post-hoc analysis of a prospective randomized study

BACKGROUND CONTEXT

Lumbar spinal canal stenosis caused by degenerative lumbar spondylolisthesis is one of the most common indications for spinal surgery. However, the factors that influence its long-term (>10 years) outcomes remain unknown.

DESIGN

This is a post-hoc analysis of a prospective randomized study.

PURPOSE

This study aimed to determine factors that influence the long-term outcomes of instrumentation surgery for lumbar spinal canal stenosis due to degenerative lumbar spondylolisthesis.

PATIENT SAMPLE

Patients aged ≤75 years with single L4/5 level lumbar canal stenosis caused by degenerative lumbar spondylolisthesis prospectively underwent instrumentation surgery at two hospitals between May 1, 2003, and April 30, 2012; the final follow-up examination was on May 20, 2021.

OUTCOME MEASURES

The following data were collected: modified Japanese Orthopedic Association (JOA) score, JOA score recovery rate, visual analog scale (VAS) score for lower back and leg pain, and scores from eight short-form 36 (SF-36) subscales preoperatively and at the final follow-up examination.

METHODS

Spearman's correlation analysis and univariate and multivariate regression analyses were used to examine preoperative factors that affect the JOA score recovery rate in patients who underwent instrumentation surgery for lumbar spinal canal stenosis at the L4/5 level due to degenerative lumbar spondylolisthesis.

RESULTS

A total of 42 patients who underwent instrumentation surgery for degenerative lumbar spondylolisthesis and had a long-term follow-up period were included. Of these, 25 and 17 underwent posterolateral fusion and Graf stabilization, respectively. The mean postoperative follow-up duration was 12.5 years. Spearman's correlation analysis revealed that the long-term recovery rate was correlated with the preoperative VAS score for low back pain. In the univariate regression analysis, sex, preoperative VAS score for low back pain, and the SF-36 general health score were significantly associated with the long-term recovery rate. Meanwhile, the multiple stepwise regression analysis identified the preoperative VAS score for low back pain as an independent predictor of the long-term recovery rate.

CONCLUSIONS

This study identified the preoperative VAS score for low back pain as an independent predictor of the long-term recovery rate following instrumentation surgery for degenerative lumbar spondylolisthesis. Therefore, when performing posterolateral fusion or Graf stabilization for degenerative lumbar spondylolisthesis, attention should be paid to the intensity of preoperative low back pain and considerations should be given to whether these procedures can improve the patient's symptoms in the long term.

Pearls and Pitfalls of Oblique Lateral Interbody Fusion: A Comprehensive Narrative Review

Lumbar degenerative disease is a common problem in an aging society. Oblique lateral interbody fusion (OLIF) is a minimally invasive surgical (MIS) technique that utilizes a retroperitoneal antepsoas corridor to treat lumbar degenerative disease. OLIF has theoretical advantages over other lumbar fusion techniques, such as a lower risk of lumbar plexus injury than direct lateral interbody fusion (DLIF). Previous studies have reported favorable clinical and radiological outcomes of OLIF in various lumbar degenerative diseases. The use of OLIF is increasing, and evidence on OLIF is growing in the literature. The indications for OLIF are also expanding with the help of recent technical developments, including stereotactic navigation systems and robotics. In this review, we present current evidence on OLIF for the treatment of lumbar degenerative disease, focusing on the expansion of surgical indications and recent advancements in the OLIF procedure.