Lower Extremity Limb Salvage: Lessons Learned From 14 Years at War

Can Repetition-based Training in a High-fidelity Model Enhance Critical Trauma Surgical Skills Among Trainees and Attending Surgeons Equally?

BACKGROUND

The evolution of warfare has resulted in a surge of high-energy blast injuries predominantly involving the lower extremities. Once thought to impact only forward-deployed military, such mechanisms of injury are becoming a harsh reality even in civilian territory. Proficiency in surgical techniques for extremity damage control is vital for surgeons, regardless of specialty. To evaluate and train surgical residents and attending surgeons in critical limb-salvage techniques, Theater Hospital Operations Replication (THOR) has been proposed as a high-fidelity training platform to enhance extremity surgery teaching practices and assess proficiency in fasciotomy, vascular shunting, and knee-spanning external fixation in a simulated, resource-limited environment.

QUESTIONS/PURPOSES

Given the importance of proficiency and efficiency in surgeon ability to perform fasciotomies, vascular shunting, and placement of external fixators, in this study, we proposed two research questions: (1) Does repetition-based training within the THOR model improve surgeon knowledge and technical skill? (2) Are there differences in skill outcome when utilizing the THOR model based on surgical specialty (orthopaedic versus general) and/or level in training (attending versus resident)?

METHODS

This was an observational learning outcome study performed in the bioskills lab at a single institution, the Naval Medical Center Portsmouth, in which 26 surgeons completed a same-day course consisting of pretraining assessment, cadaver training on three damage-control surgery techniques in a high-fidelity THOR environment, and post-training assessment. The surgeons were either general surgeons or orthopaedic surgeons and consisted of both residents and attending surgeons. Subjects underwent a pretraining knowledge assessment, followed by two rounds of performing simulated surgery. The first round of surgery included guidance and instruction from board-certified orthopaedic surgeons. After a short break for the subjects to review the material, the second round was completed without instruction. To answer our first question of how repetition-based training impacts surgical skill, our metrics included: Objective Structured Assessment of Technical Skills (OSATS) scores (range 1 to 5, scored lowest to highest, where higher scores represent optimal skill performance), procedural accuracy, a 10-question knowledge assessment administered before and after training (scored 0 to 10, where higher scores represent competency of the anatomy and procedure steps), and total procedure time. To address our second question, data on demographic characteristics were collected on all participants, which included surgical specialty, year in training, and gender.

RESULTS

The general surgery residents' cohort demonstrated improvement in both mean ± SD OSATS scores (2.4 ± 0.7 before training versus 3.6 ± 0.6 after training, mean difference 1.2 [95% CI 0.4 to 2.0]; p = 0.01) and procedure duration (23 ± 7 minutes before training versus 16 ± 5 minutes after training, mean difference 6 minutes [95% CI 4 to 9]; p = 0.001) for external fixator procedures after THOR. Similar results were seen in fasciotomies after THOR. The orthopaedic surgery residents' cohort showed similar improvements in reducing procedure duration when performing knee-spanning external fixator surgery, as well as exhibited improvements during vascular shunting procedures in both mean ± SD OSATS scores (previously 3.3 ± 0.9 versus 4.0 ± 0.9, mean difference 0.7 [95% CI 0.2 to 1.2]; p = 0.01) and procedure duration (23 ± 5 minutes versus 14 ± 8 minutes, mean difference 10 minutes [95% CI 4 to 15]; p = 0.003) after THOR. When we compared the cohorts, general surgery attending surgeons demonstrated an improvement in vascular shunting procedure duration after instruction with the THOR model (19 ± 3 minutes versus 12 ± 4 minutes, mean difference 7 minutes [95% CI 1 to 13]; p = 0.03) and in overall knowledge scores (4.3 + 0.5 versus 8.0 ± 1.6, mean difference 3.8 [95% CI 0.5 to 7.0]; p = 0.04). The orthopaedic surgery attending surgeons yielded no improvement for any metric, pretraining and post-training. Using the prescores as a covariate, for almost all metrics analyzed, there were no differences between surgeon groups based on specialty after completing the repeated training.

CONCLUSION

Use of the high-fidelity THOR training model improved proficiency in the examined sample of extremity damage-control procedures, thus demonstrating its efficacy in enhancing surgical skills and short-interval knowledge retention while simultaneously highlighting the importance of cadaver simulation training in enhancing surgical preparedness for complex trauma.

CLINICAL RELEVANCE

The high-fidelity THOR training model represents a promising modality for preparing surgeons for extremity combat trauma management in resource-limited, high-stress environments. Whether in a wartime environment or in the civilian sector, efficient and skilled intervention are crucial in managing patient morbidity. Differences of a few minutes per procedure can mean all the difference in damage control, especially when compounded in situations where vascular shunting, knee-spanning external fixation, and lower leg four-compartment fasciotomy have to be performed together by both orthopaedic and general surgeons. The observational period in this study spanned 1 day and thus does not provide information on retention of long-term skills or knowledge. A follow-on study can assess how time from initial training to final evaluation impacts overall skill competency and knowledge.

What is the Case Volume of Orthopaedic Trauma Surgeons in the Military Health System? An Assessment of Wartime Readiness and Skills Sustainment

INTRODUCTION

Complex, high-energy extremity trauma secondary to explosive mechanisms has been increasingly common in modern warfare, accounting for a majority of combat wounds throughout the conflicts in Iraq and Afghanistan. Fellowship-trained orthopaedic trauma surgeons treated many of these complex injuries; however, as the number of casualties continue to decrease during a period of relative peace, a growing concern over maintaining military trauma readiness exists.

METHODS

The Military Health System Data Repository was queried for all Common Procedural Terminology (CPT) codes associated with 18 fellowship-trained orthopaedic trauma surgeons from 2013 to 2019. The codes were further analyzed and categorized based on common trauma subspecialty procedures such as fracture fixation of the pelvic ring, acetabulum, upper and lower extremity, peri-articular, and nonunion/malunion surgery. We used descriptive statistics to quantify both the average number of cases per surgeon per year in each of the subcategories and case volume among Military Treatment Facilities (MTFs) during the study period.

RESULTS

We identified 7,769 CPT codes for surgical procedures throughout the study period. The most common surgical procedures performed were: removal of implant (n = 836, 11%), knee arthroscopy (n = 507, 7%), and debridement of devitalized tissue (n = 345, 4%). The total trauma subspecialty procedural codes and average cases per surgeon per year were as follows: pelvic ring (n = 54, <1 case/year), acetabulum (n = 90, 1 case/year), upper extremity (n = 1,314, 15 cases/year), lower extremity (n = 2,286, 25 cases/year), peri-articular (n = 675, 8 cases/year), and nonunion/malunion (n = 288, 3 cases/year). San Antonio Military Medical Center (SAMMC) accounted for the most fracture-related CPT codes overall (35%), while all other MTFs contributed approximately 10% or less of all fracture-related codes.

CONCLUSIONS

These results highlight the lack of orthopaedic trauma volume at other MTFs outside of SAMMC, raising concern for maintaining military readiness during an inter-war period of relative peace. The DoD continues to make concerted efforts to maintain readiness through civilian partnerships and subsequently increase surgical case volume for military trauma surgeons. Future efforts should include an in-depth analysis of caseloads of military trauma surgeons providing care at both MTFs and civilian institutions to optimize preparedness in future conflicts.

A Longitudinal Perspective on Conversion to Amputation for Combat-Related Extremity Injuries Treated With Flap-Based Limb Salvage

OBJECTIVES

To define the rate and primary drivers behind early and late amputation after flap-based limb salvage in the setting of combat extremity trauma.

DESIGN

Retrospective review.

SETTING

Level II trauma center.

PATIENTS

307 (303 men, 4 women) patients who underwent flap-based limb salvage treatment between 2003 and 2014.

INTERVENTION

We reviewed patient medical records, radiographs, and clinical photographs.

MAIN OUTCOME MEASUREMENTS

Early and late amputation rates, time to amputation, reason for amputation.

RESULTS

307 patients accounted for 323 limbs that underwent flap-based limb salvage treatment (187 lower extremities, 136 upper extremities). A total of 58 extremities (18%) initially treated with flap-based limb salvage ultimately underwent amputation at a median of 480 days (IQR, 285-715 days) from injury. Periarticular fractures and lower extremity injuries were risk factors for early and late amputation. Other independent risk factors for early amputation were flap complications and vascular injuries, whereas risk factors for late amputation were fractures that went on to nonunion.

CONCLUSIONS

This study highlights that a subset of patients ultimately require major limb amputation despite having achieved what is initially considered "successful" limb salvage. Flap-related complications, vascular injury, and lower extremity site of injury were associated with early amputation after successful expeditionary efforts at limb preservation. Conversion to late amputation was associated with lower extremity periarticular fractures and fracture nonunion. Chronic pain and persistent limb dysfunction were the most common reasons for late amputation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical evaluation of a tool-less external fixator

INTRODUCTION

Current external fixator systems used by the US and UK military for stabilising extremity fractures require specialised tools to build a construct. The goal of obtaining and maintaining limb length and alignment is not achieved if these tools are misplaced. An alternative, tool-less system is currently available, namely the Dolphix Temporary Fixation System. The aim of this study was to compare the stiffness of the Dolphix system with the existing Hoffmann III system.

METHODS

Three Hoffmann III and three Dolphix constructs were assembled on a bone (tibia) surrogate. A 30 mm fracture gap was created to simulate a comminuted proximal tibia or distal femur fracture. The constructs were then tested in cyclic axial compression once daily for 3 consecutive days.

RESULTS

The length and alignment of the surrogate limb was restored following each testing cycle with both external fixation systems. The stiffness of the constructs was maintained throughout each sequential test, with the Dolphix exhibiting 54% the stiffness of the Hoffmann III construct.

CONCLUSION

Given the Dolphix's performance in mechanical testing and the unique advantage of having a tool-less manual locking clamp mechanism, this tool-less system should be considered for use in the mobile austere environment.

Blood Flow Restriction Therapy: From Development to Applications

Blood flow restriction (BFR) has been shown to produce beneficial adaptations to skeletal muscle. These adaptations have been documented in the civilian and military populations. BFR therapy may provide patients a safe method to begin strength training at earlier stages of rehabilitation to allow for earlier and more effective return to activity and improved military readiness. The purpose was to review BFR therapy physiology, complications, side effects, standardized treatment algorithms, and long-term patient outcomes.