C. Edward Hoffler

Risk Factors for Ulnar Nerve Instability Resulting in Transposition in Patients With Cubital Tunnel Syndrome

PURPOSE To assess the incidence of ulnar nerve instability in patients undergoing in situ decompression and to identify preoperative risk factors to predict the need for transposition. METHODS Using our surgical database, we retrospectively identified 363 patients who were candidates for in situ ulnar nerve decompression for the treatment of cubital tunnel syndrome over a 5-year period. During this time, the 3 participating surgeons considered ulnar nerve instability to be a contraindication for in situ ulnar nerve decompression. We collected demographic data including sex, age, weight, height, and body mass index. We recorded the number of patients who underwent ulnar nerve transposition owing to ulnar nerve instability and evaluated whether ulnar nerve instability was diagnosed before, during, or after surgery. RESULTS Of the 363 patients who were considered for in situ ulnar nerve decompression, 76 patients (21%) underwent ulnar nerve transposition secondary to ulnar nerve instability. Twenty-nine patients (8%) were identified with instability before surgery, and 44 patients (12%) were identified with instability during surgery following in situ decompression. Three patients (1%) were not diagnosed with instability until after surgery and subsequently underwent secondary transposition. Patients who underwent transposition owing to instability were more likely to be male and to be younger. CONCLUSIONS A notable percentage of patients with a stable nerve before surgery will have ulnar nerve instability following decompression. Identification of factors correlating to instability and the potential need for transposition can aid surgeons and patients in preoperative planning.

Hand Surgery and Fluoroscopic Eye Radiation Dosage A Prospective Pilot Comparison of Large Versus Mini C-Arm Fluoroscopy Use

Background: The purpose of this study is to (1) perform a prospective pilot comparison of the impact of large versus mini C-arm fluoroscopy on resultant eye radiation exposure and (2) test the hypothesis that the use of either modality during routine hand surgery does not exceed the current recommended limits to critical eye radiation dosage. Methods: Over a 12-month period, eye radiation exposure was prospectively measured by a board-certified hand surgeon using both large and mini C-arm fluoroscopy. For each modality, accumulated eye radiation dosage was measured monthly, while fluoroscopic radiation output was recorded, including total exposure time and dose rate. Results: A total of 58 cases were recorded using large C-arm and 25 cases using mini C-arm. Between the 2 groups, there was not a significant difference with total exposure time (P = .88) and average dose rate per case (P = .10). With the use of either modality, average monthly eye radiation exposure fell within the undetectable range (<30 mrem), significantly less than the current recommended limit of critical eye radiation (167 mrem/month). Conclusions: The impact of various fluoroscopic sources on eye radiation exposure remains relatively unexplored. In this study, the minimal detectable eye radiation dosages observed in both groups were reliably consistent. Our findings suggest that accumulated eye radiation dosage, from the use of either fluoroscopic modality, does not approach previously reported levels of critical radiation loads.

Technique for Intramedullary Stabilization of Ulnar Neck Fractures

Background: Distal ulna fractures at the ulnar neck can be seen in association with distal radius fractures, and multiple techniques have been described to address the ulnar neck component of these injuries. We have found that treatment of ulnar neck fractures can be challenging in terms of anatomy and fracture fixation. We present a new percutaneous fixation technique for ulnar neck fractures commonly seen with distal radius fractures. Technique: Fixation of the ulnar neck fracture is performed after fixation of the distal radius fracture. Our technique uses anterograde intramedullary fixation to stabilize the fracture with a 1.6-mm (0.062 inch) Kirschner wire or a commercially available metacarpal fixation intramedullary nail. The fixation is introduced into the intramedullary space of the ulnar shaft 4 to 6 cm proximal to the fracture at a separate surgical site along the subcutaneous border of the ulna. The fixation is also supported with a sugar-tong splint for the first few weeks after surgery and requires removal of the ulnar implant approximately 10 weeks after implantation. Conclusion: Our technique utilizes a percutaneous approach with minimal fracture exposure. It provides a relatively simple and reproducible method to address ulnar neck fractures commonly seen in association with distal radial fractures.