Validation of a High-Fidelity Fracture Fixation Model for Skill Acquisition in Orthopedic Surgery Residents.

OBJECTIVE: Simulation has become a widely accepted part of training and credentialing processes due to its ability to supplement technical skill acquisition outside of the operating room (OR). This project explores implementation of a bench-top simulation of open reduction with internal fixation (ORIF) as a cost-effective method for practicing and evaluating surgical skill. DESIGN, SETTING, AND PARTICIPANTS: Participants ranging from intern to attending surgeon performed ORIF using a standard fixation set and a bovine or porcine tibia/radius model. Performance was recorded and scored by blinded reviewers based on a modified global rating scale (GRS), objective structured assessment of technical skills (OSATS) procedure-specific checklist, and critical-mistakes (CM) model. We calculated Fleiss' kappa for inter-rater reliability, Cronbach's alpha for internal consistency of scoring systems, and used univariate analysis to determine the ability of this model to discriminate between training levels. We also performed a normalized performance-versus-cost analysis to characterize perceived value of this simulation compared to other modalities. RESULTS: Twenty subjects completed the fracture fixation exercise. Fleiss' kappa for all scoring systems indicated substantial inter-rater agreement (k = 0.81, 0.80, and 0.74 for GRS, OSATS, and CM, respectively). Internal consistency reliability for GRS and OSATS were high with Cronbach's alpha 0.96(95%CI 0.94-0.97) and 0.94(95%CI 0.91-0.96), respectively. Using a Kuskal-Wallis rank sum test, GRS, OSATS, and CM were found effective for measuring differences between resident levels (p < 0.001, p < 0.001, and p = 0.002, respectively). Qualitative valuation of the exercise indicated similar value for education compared to time spent in the OR and surgical skills labs. CONCLUSIONS: This benchtop surgical simulation provides quantitative measurement of operative skills progression, increases trainee familiarity with ORIF principles, and permits targeted education by senior surgeons with the goal of training safe graduates. Procedure-specific checklist grading tools reliably differentiated between training levels with high internal validity. Implementing this model may decrease training costs and accelerate skill acquisition.

Radial Nerve Injury in Humeral Shaft Fracture.

Radial nerve injury with humeral shaft fracture is common. Treatment options include expectant management, early exploration and repair, delayed reconstruction, nerve transfers, and tendon transfers. Knowledge of the appropriate application of these treatments will assist orthopedic surgeons and nerve surgeons in coordinating care for these patients.

Factors Associated with Primary and Secondary Amputation following Limb-Threatening Upper Extremity Trauma.

BACKGROUND: The aim of this study was to assess the factors associated with primary and secondary amputation in patients with limb-threatening trauma to the upper extremity, describe the incidence of these injuries, and describe the procedures involved in the treatment of these difficult injuries. METHODS: A retrospective study of 49 cases (in 47 patients) with acute limb-threatening trauma of the upper extremity proximal to the carpometacarpal joint level treated with either amputation or limb salvage was performed in two urban level I trauma centers between January of 2001 and January of 2018. RESULTS: Bivariate analysis demonstrated that cases of primary amputation more frequently had a higher Injury Severity Score, higher Abbreviated Injury Scale score, more proximal fractures, more severe muscle injuries, and a larger number of major nerve injuries. Secondary amputation, compared with limb salvage, was more frequently performed in patients who were younger, in cases with a higher Injury Severity Score, where there was more proximal soft-tissue injury, in case of nonsharp mechanism of injury, and in cases that required local flap procedures for wound closure. The authors found a yearly incidence of 62 cases of acute limb-threatening upper extremity trauma per 100,000 trauma admissions. CONCLUSIONS: Multiple factors influence the surgical decision to perform primary amputation or to attempt a salvage procedure following limb-threatening upper extremity trauma. Knowing which patients will have the most favorable outcomes of a salvage procedure is important, because salvage procedures impose a greater burden on the health care system and the patient, even more so in the case of secondary amputation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

The Flexor Pollicis Longus Tendon Does Not Lie Parallel to the Thumb Metacarpal.

BACKGROUND: Repair of the flexor pollicis longus (FPL) tendon by tendon retriever can be challenging because of uncertainty of the optimal direction. This study aims to describe the FPL tendon path in the thenar eminence. METHODS: In 18 hands of 9 cadavers, the angle of the FPL tendon was, after dissection, measured in relation to the axis formed between the metacarpophalangeal (MCP) joint of the thumb and the dorsal carpometacarpal joint (MC1-axis) and the axis formed between the second MCP joint and the distal edge of the trapezium (MC2-axis). RESULTS: The FPL does not follow the angle of the thumb metacarpal. The FPL runs ulnarly from the MC1-axis at a median of 32.5° in abduction and 30.6° in adduction. In relation to the MC2-axis, it runs at a median of 47.5° in abduction and 25° in adduction. CONCLUSIONS: The FPL tendon path can be preoperatively marked using: (1) the MC1-axis from which it runs ulnarly approximately at an angle of 30° in both abduction and adduction; or (2) the MC2-axis from which it runs radially at an angle of 47.5° in abduction and at an angle of 25° in adduction. We conclude that the FPL tendon path can be preoperatively marked using these axes and does not parallel the metacarpal axes of the thumb.

Semiautomated analysis of dendrite morphology in cell culture.

Quantifying dendrite morphology is a method for determining the effect of biochemical pathways and extracellular agents on neuronal development and differentiation. Quantification can be performed using Sholl analysis, dendrite counting, and length quantification. These procedures can be performed on dendrite-forming cell lines or primary neurons grown in culture. In this protocol, we describe the use of a set of computer programs to assist in quantifying many aspects of dendrite morphology, including changes in total and localized arbor complexity.