Comparison of anterior-only versus combined anterior and posterior fusion for unstable subaxial cervical injuries: a meta-analysis of biomechanical and clinical studies

Assessing Neurosurgery Training: Accreditation Council for Graduate Medical Education Case Minimums Versus Surgical Autonomy

BACKGROUND AND OBJECTIVES

The Accreditation Council for Graduate Medical Education (ACGME) requires neurosurgery residents to reach a set number of cases in specified procedure types (case minimums) before graduation and mandates completion of Milestones. We used the Surgical Autonomy Program, a validated method of autonomy-based resident evaluation, to determine the number of cases it took for residents to become competent and compared these with the ACGME case minimums.

METHODS

We collected data from neurosurgery residents at Duke University on 7 procedures (tumor craniotomy, trauma craniotomy, ventriculoperitoneal shunt, anterior cervical discectomy and fusion (ACDF), posterior cervical fusion (PCF), discectomy/laminectomy, and posterior thoracolumbar spinal fusion [PSF]). We defined competency as being graded at the highest autonomy level in the Surgical Autonomy Program by attending neurosurgeons for the first and second time and determined the case volume on the ACGME case log when these were achieved. These results were analyzed with summary statistics.

RESULTS

The median case volume among residents (N = 4-8) for the first and second competency rating (and ACGME minimum) for each procedure type was found to be: tumor: 44.5 and 64.5 (min. 60), trauma: 21 and 30 (min. 60), ventriculoperitoneal shunt: 11.3 and 13 (min. 20), ACDF: 30 and 32.5 (min. 20), PCF: 24 and 40 (min. 30), discectomy/laminectomy: 28 and 36 (min. 30), and PSF: 51 and 54 (min. 30).

CONCLUSION

We found variation in the case numbers to reach competency and that for some procedures (tumor, ACDF, PCF, discectomy/laminectomy, and PSF), most residents required more cases than the ACGME case minimums to achieve competency. The ACGME case minimums may not accurately reflect the number of cases required for neurosurgical residents to reach competency. To promote trainee-centered education, individualized, competency-based evaluation systems may be better determining readiness for graduation, including a system that builds off the established ACGME Milestones.

The correlation between biomechanical experiments and clinical studies in orthopedics: a systematic review

PURPOSE

To evaluate the clinical relevance of biomechanical experiments by conducting a systematic review of orthopedic studies that compared treatments with both a biomechanical experiment and a clinical study.

METHODS

A systematic search of MEDLINE/PUBMED was performed to identify orthopedic studies that included both a biomechanical experiment and a clinical study to compare treatments. The association between a difference in the outcome of the biomechanical experiment and a difference in the outcome of the clinical study was evaluated.

RESULTS

There were 23 studies that were included. The orthopedic specialty of the studies included trauma (n = 17), pediatric trauma (n = 2), sports (n = 2), and hand (n = 1). The anatomic areas of each study included the hip/femur (n = 11), shoulder/humerus (n = 3), elbow/forearm (n = 2), knee/tibia (n = 3), ankle/foot (n = 2), pelvis/acetabulum (n = 1), and hand (n = 1). The biomechanical experiments involved cadavers (n = 14), synthetic bone (n = 5), finite element analysis (n = 3), and animals (n = 1). The biomechanical experiment from each study, compared to the clinical study, was more likely to report a difference in outcomes (82.6% (19/23) vs. 30.4% (7/23), p = 0.0008). The findings of the biomechanical experiment and the clinical study were in agreement in 43.4% (10/23) of the studies. Studies that reported a difference in the biomechanical outcome, compared to those that did not, were not more likely to report a difference in the clinical outcome (31.6% (6/19) vs. 25.0% (1/3), p = 1.0).

CONCLUSIONS

The outcomes of biomechanical experiments did not correlate with clinical study outcomes. Considering these findings, the utility of biomechanical experiments in orthopedics should be reexamined.

LEVEL OF EVIDENCE

Level 3.

Analysis of risk factors affecting postoperative neurological recovery in patients with cervical spine fracture in ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic progressive inflammatory disease that mainly affects the spine and involves the sacroiliac and peripheral joints. Low-energy trauma can often lead to spinal fractures and spinal cord injuries (SCIs), the treatment of AS is challenging. The prognosis of neurological function in patients with AS cervical fracture and SCI is a major problem that must sought clinician attention on urgent basis. A total of 106 patients with AS cervical fractures who underwent surgical treatment at Shanghai Changzheng Hospital between August 2009 and 2021 were included in this study. All the patients were divided into 2 groups (improved group and the control group) based on their neurological function improvement at 1 year mark after the surgery. The baseline characteristics, perioperative factors, and procedural outcomes of all the patients including injury type, AS drug treatment, the injured segment, ossified anterior longitudinal ligament injury, spinal hypersignal, decompression time window, operation duration, blood loss, preoperative and postoperative American Spinal Injury Association (ASIA) score were recorded and analyzed. Among the 106 patients, 79 demonstrated improved neurological function at 1 year mark after the surgery. Binary univariate logistic regression analysis revealed significant differences in injury type (P = .018), ossified anterior longitudinal ligament injury (P = .01), operation duration (P = .002), spinal hypersignal (P = .001), preoperative ASIA score (P < .001), and prior AS drug treatment (P = .012). No significant differences were observed in the other variables (P > .05). Binary multivariate logistic regression analysis identified spinal hypersignal (OR = 37.185, P = .028), preoperative ASIA score (OR = 0.16, P = .012) and previous AS drug treatment (OR = 0.296, P = .049) as factors associated with postoperative neurological function improvement. The preoperative ASIA score and previous drug treatment of AS were identified as protective factors affecting the improvement of neurological functions in patients with AS cervical fracture after surgery. Preoperative T2-weighted spinal hypersignal was identified as an independent risk factor affecting the improvement of neurological function recovery in patients with AS cervical fracture after the surgery.

Outcome and complications of operatively treated subaxial cervical spine injuries: A population-based retrospective cohort study

Objective

The aim was to study the outcome and complications of operative treatment for subaxial cervical spine injuries with respect to injury morphology and surgical strategy.

Methods

A population-based cohort of 271 consecutive patients treated at Kuopio University Hospital from 2003 to 2018 was retrospectively reviewed.

Results

The mean age was 52.4 (range 12-90) years and 78.6% were male. The AOSpine morphological classification was C in 56.5%, B in 24.7% and A in 17.0% of cases. The surgical approach was anterior in 70.8%, posterior in 20.3% and combined in 8.9% of patients. Fixation alignment was maintained in 96.9% of patients. Instrumentation failures were observed only in patients operated anteriorly but no statistical difference was found between the surgical approaches. The American Spinal Injury Association Impairment Scale (AIS) grade improved in 22.1% of patients. Patients with preoperative AIS grade C had significant potential for neurological improvement (OR 10.44; 95% CI 1.77-61.56; p = 0.010). Postoperative, mostly mild, complications manifested in 22.5% of patients. The posterior approach was associated with fewer postoperative complications (OR 0.18; 95% CI 0.06-0.51; p = 0.001). Preoperative AIS grade A was a significant predisposing factor for complications (OR = 4.90; 95% CI = 1.49-16.10; p = 0.009). The perioperative (90-day) mortality rate was 3.3%. The mean follow-up period was 64.7 ± 25.9 (radiological)/136.7 ± 174.8 (clinical) days.

Conclusions

Operative treatment is safe and effective but the surgical approach should be patient- and injury-specific. The prognosis for neurological recovery from spinal cord injury is superior in patients with partially preserved motor function.

Clinical and radiological outcomes of one-level cervical corpectomy with an expandable cage for three-column uncomplicated subaxial type «B» injures: a multicenter retrospective study

PURPOSE

To evaluate the clinical and radiological results of the operative management of three-column uncomplicated type «B» subaxial injures treated with a one-level cervical corpectomy with an expandable cage.

METHODS

This study included 72 patients with a three-column uncomplicated type «B» subaxial injures who met the inclusion criteria, underwent a one-level cervical corpectomy with an expandable cage at one of three neurosurgical departments between 2005 and 2020, and were followed up for clinical and radiological outcomes at a minimum 3-yr follow-up.

RESULTS

There was a decrease in the VAS pain score from an average of 80 mm to 7 mm (p = 0.03); a decrease in the average NDI score from 62 to 14% (p = 0.01); excellent and good outcomes according to Macnab's scale were 93% (n = 67/72). There was an average change in the cervical lordosis (Cobb method) from -9.10 to -15.40 (p = 0.007), without significant loss of lordosis (p = 0.27). There was no significant degeneration of the adjacent levels by 3 years post-op. The fusion rate, using the Cervical Spine Research Society criteria, was poor: it was 62.5% (n = 45/72), and using the CT criteria, it was 65.3% (n = 47/72). 15.4% patients (n = 11/72) suffered complications. Statistical difference between the fusion and pseudoarthrosis (according to X-ray criteria) subgroups showed that there were no statistically significant differences in the smoking status, diabetes, chronic steroid use, cervical injury level, subtypes of AO type B subaxial injuries and types of expandable cage systems.

CONCLUSIONS

One-level cervical corpectomy with an expandable cage, despite a poor fusion rate, can be considered a feasible and relatively safe method for treating three-column uncomplicated subaxial type «B» injures, with the benefit of immediate stability, anatomical reduction, and direct decompression of the spinal cord. While no one in our series had any catastrophic complications, we did note a high complication rate.