Human Exposure to Hand-Arm Vibration from a Surgical Drill During Simulated Spine Surgery

OBJECTIVE

During spine surgery, surgeons are exposed to vibrations from surgical drills. Increased exposure to vibration can result in neurologic, vascular, and musculoskeletal impairments. To reduce these risks, occupational health standards have been implemented to limit exposure levels. The purpose of this study was to quantify human exposure to hand-arm vibration from a surgical drill during a simulation of a common spine procedure.

METHODS

Vibration measurements were collected during three 30-second surgical trials on a fresh frozen cadaver torso specimen using a standard surgical drill. The daily vibration exposure A(8) was evaluated on the basis of International Organization for Standardization 5349-1, and the occupational health standards, exposure action value, and exposure limit value were calculated.

RESULTS

On the basis of vibration exposure, surgeons in this study reached their exposure limits in 8 minutes to monitor tool usage and 32 minutes to terminate equipment usage.

CONCLUSIONS

The results demonstrate that a common surgical drill transmits hand-arm vibration levels approaching the exposure action value and exposure limit value over short periods of use. Further investigation is needed to determine the total vibration exposure over an entire workday, specifically in surgeons who perform multiple surgeries within a single day.

An ACGME-based comparison of neurosurgical and orthopedic resident training in adult spine surgery via a case volume and hours-based analysis

OBJECTIVE

In a 2014 analysis of orthopedic and neurological surgical case logs published by the Accreditation Council for Graduate Medical Education (ACGME), it was reported that graduating neurosurgery residents performed more than twice the number of spinal procedures in their training compared with graduating orthopedic residents. There has, however, been no follow-up assessment of this trend. Moreover, whether this gap in case volume equates to a similar gap in procedural hours has remained unstudied. Given the association between surgical volume and outcomes, evaluating the status of this disparity has value. Here, the authors assess trends in case volume and procedural hours in adult spine surgery for graduating orthopedic and neurological surgery residents from 2014 to 2019.

METHODS

A retrospective analysis of ACGME case logs from 2014 to 2019 for graduating orthopedic and neurological surgery residents was conducted for adult spine surgeries. Case volume was converted to operative hours by using periprocedural times from the 2019 Medicare/Medicaid Physician Fee Schedule. Graduating residents' spinal cases and hours, averaged over the study period, were compared between the two specialties by using 2-tailed Welch's unequal variances t-tests (α = 0.05). Longitudinal trends in each metric were assessed by linear regression followed by cross-specialty comparisons via tests for equality of slopes.

RESULTS

From 2014 to 2019, graduating neurosurgical residents logged 6.8 times as many spinal cases as their orthopedic counterparts, accruing 431.6 (95% CI 406.49-456.61) and 63.8 (95% CI 57.08-70.56) cases (p < 0.001), respectively. Accordingly, graduating neurosurgical residents logged 6.1 times as many spinal procedural hours as orthopedic surgery residents, accruing 1020.7 (95% CI 964.70-1076.64) and 166.6 (95% CI 147.76-185.35) hours (p < 0.001), respectively. Over these 5 years, both fields saw a linear increase in graduating residents' adult spinal case volumes and procedural hours, and these growth rates were higher for neurosurgery (+16.2 cases/year vs +4.4 cases/year, p < 0.001; +36.4 hours/year vs +12.4 hours/year, p < 0.001).

CONCLUSIONS

Graduating neurosurgical residents accumulated substantially greater adult spinal case volumes and procedural hours than their orthopedic counterparts from 2014 to 2019. This disparity has been widened by a higher rate of growth in adult spinal cases among neurosurgery residents. Accordingly, targeted efforts to increase spinal exposure for orthopedic surgery residents-such as using cross-specialty collaboration-should be explored.

Resident operative experience in pediatric neurosurgery across the United States

OBJECTIVE

Neurosurgical residents receive exposure to the subspecialty of pediatric neurosurgery during training. The authors sought to determine resident operative experience in pediatric neurosurgery across Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgical programs.

METHODS

During 2018-2019, pediatric neurosurgical case logs for recent graduates or current residents who completed their primary pediatric exposure were collected from US continental ACGME training programs. Using individual resident reports and procedure designations, operative volumes and case diversity were analyzed collectively, according to training site characteristics, and also correlated with the recently described Resident Experience Score (RES).

RESULTS

Of the 114 programs, a total of 316 resident case logs (range 1-19 residents per program) were received from 86 (75%) programs. The median cumulative pediatric case volume per resident was 109 (IQR 75-161). Residents at programs with a pediatric fellowship reported a higher median case volume (143, IQR 96-187) than residents at programs without (91, IQR 66-129; p < 0.0001). Residents at programs that outsource their pediatric rotation had a lower median case volume (84, IQR 52-114) compared with those at programs with an in-house experience (117, IQR 79-170; p < 0.0001). The case diversity index among all programs ranged from 0.61 to 0.80, with no statistically significant differences according to the Accreditation Council for Pediatric Neurosurgery Fellowships designation or pediatric experience site (p > 0.05). The RES correlated moderately (r = 0.44) with median operative volumes per program. A program's annual pediatric operative volume and duration of pediatric experience were identified as significant predictive factors for median resident operative volume.

CONCLUSIONS

Resident experience in pediatric neurosurgery is variable within and between programs. Case volumes are generally higher for residents at programs with in-house exposure and an accredited fellowship, but case diversity is relatively uniform across all programs. RES provides some insight on anticipated case volume, but other unexplained factors remain.

The effect of simulation training on resident proficiency in thoracolumbar pedicle screw placement using computer-assisted navigation

OBJECTIVE

Residency work-hour restrictions necessitate efficient, reproducible training. Simulation training for spinal instrumentation placement shows significant benefit to learners' subjective and objective proficiency. Cadaveric laboratories are most effective but have high cost and low availability. The authors' goal was to create a low-cost, efficient, reproducible spinal instrumentation placement simulation curriculum for neurosurgery and orthopedic surgery residents using synthetic models and 3D computer-assisted navigation, assessing subjective and objective proficiency with placement of thoracolumbar pedicle screws.

METHODS

Fifteen neurosurgery and orthopedic surgery residents participated in a standardized curriculum with lecture followed by two separate sessions of thoracolumbar pedicle screw placement in a synthetic spine model utilizing 3D computer-assisted navigation. Data were collected on premodule experience, time and accuracy of screw placement, and both subjective and objective ratings of proficiency.

RESULTS

Fifteen of 15 residents demonstrated improvement in subjective (Physician Performance Diagnostic Inventory Scale [PPDIS]) and 14 in objective (Objective Structured Assessment of Technical Skills [OSATS]) measures of proficiency in navigated screw placement with utilization of this curriculum (p < 0.001 for both), regardless of the number of cases of previous experience using thoracolumbar spinal instrumentation. Fourteen of 15 residents demonstrated decreased time per screw placement from session 1 to session 2 (p = 0.006). There was no significant difference in pedicle screw accuracy between session 1 and session 2.

CONCLUSIONS

A standardized curriculum using synthetic simulation training for navigated thoracolumbar pedicle screw placement results in significantly improved resident subjective and objective proficiency. Development of a nationwide competency curriculum using simulation training for spinal instrumentation placement should be considered for safe, efficient resident training.