Vascular Supply to the Femoral Head in Patients With Healed Slipped Capital Femoral Epiphysis.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is one of the most common hip disorders. The vascularity of the lateral epiphyseal vessels supplying the femoral head in patients with healed SCFE has not been well defined. The purpose of this study was to characterize the location and number of lateral epiphyseal vessels in young adults with healed SCFE. METHODS: This was a retrospective study of 17 patients (18 hips) with a diagnosis of SCFE and a matched control group of 17 patients (17 hips) with developmental dysplasia of the hip. All patients underwent high-resolution contrast-enhanced magnetic resonance imaging to visualize the path of the medial femoral circumflex artery and the lateral epiphyseal arterial branches supplying the femoral head. RESULTS: There were 5 unstable SCFEs and 13 stable SCFEs with an average slip angle of 31 degrees. (All patients had been treated with in situ pinning and screw removal). Average age at time of magnetic resonance imaging was 24.5 years (range, 15 to 34 y). The lateral epiphyseal vessels reliably inserted on the posterior-superior aspect of the femoral neck from the superior-anterior to the superior-posterior position in both the SCFE and control groups. An average of 2 (±0.8) retinacular vessels were identified in the SCFE group compared with 5.2 (±0.7) retinacular vessels in the control group (P<0.001). CONCLUSIONS: In healed SCFE, the lateral epiphyseal vessels reliably insert in the same anatomic region as patients with hip dysplasia; however, the overall number of vessels is significantly lower.

Training femoral neck screw insertion skills to surgical trainees: computer-assisted surgery versus conventional fluoroscopic technique.

BACKGROUND: : Femoral neck fractures are among the most common orthopaedic injuries impacting the health care system. Surgical management of such fractures with cannulated screws is a commonly performed procedure. The acquisition of surgical skills necessary to perform this procedure typically involves learning on real patients with fluoroscopic guidance. This study attempts to determine if a novel computer-navigated training model improves the learning of this basic surgical skill. METHODS: A multicenter, prospective, randomized, and controlled study was conducted using surgical trainees with no prior experience in surgically managing femoral neck fractures. After a training session, participants underwent a pretest by performing the surgical task (screw placement) on a simulated hip fracture using fluoroscopic guidance. Immediately after, participants were randomized into either undergoing a training session using conventional fluoroscopy or computer-based navigation. Immediate posttest, retention (4 weeks later), and transfer tests were performed. Performance during the tests was determined by radiographic analysis of hardware placement. RESULTS: Screw placement by trainees was ultimately equal to the level of an expert surgeon with either training technique. Participants who trained with computer navigation took fewer attempts to position hardware and used less fluoroscopy time than those trained with fluoroscopy. When those trained with fluoroscopy used computer navigation at the transfer test, less fluoroscopy time and dosage was used. The concurrent augmented feedback provided by computer navigation did not affect the learning of this basic surgical skill in surgical novices. No compromise in learning occurred if the surgical novice trained with one type of technology and transferred to using the other. CONCLUSIONS: The findings of this study suggest that computer navigation may be safely used to train surgical novices in a basic procedure. This model avoids using both live patients and harmful radiation without a compromise in the acquisition of a 3-dimensional technical skill.

Synchronous occurrence of metastatic Wilms tumor and ganglioneuroma.

We describe a 4-year-old female patient with a persistent paraspinal mass following chemotherapy for Wilms tumor. A discordant response to chemotherapy prompted biopsy of the persistent mass, which revealed a ganglioneuroma. This report highlights the synchronous occurrence of different tumors in the same patient, and suggests that repeat biopsies should be considered when contiguous tumor masses do not respond as expected.