The Effect of Traction Force and Hip Abduction Angle on Pudendal Nerve Compression in Hip Arthroscopy: A Cadaveric Model.

PURPOSE: To investigate the site of pudendal nerve compression and the relation between traction force and abduction angle regarding pressure levels at setup for hip arthroscopy. METHODS: A total of 17 hips from 9 fresh-frozen cadavers (6 male and 3 female cadavers) were used. The pudendal nerves were dissected, and 3 FlexiForce force sensors (Tekscan, Boston, MA) were implanted on the pudendal nerve where the inferior rectal nerve, perineal nerve, and dorsal nerve of the clitoris/penis emerge. A custom-made traction table in a supine position was used with a padded perineal post of 9 cm. Recordings were made at 0, 10, 20, 30, and 40 kg of traction at varying hip abduction angles of 0°, 15°, 30°, and 45°. RESULTS: The tuber ischiadicum (perineal nerve) and genital region (dorsal nerve of penis/clitoris) had statistically higher pressure values when compared with the pudendal canal (inferior rectal nerve) (P < .05). There was a significant increase in forces acting on the pudendal nerve with increasing application of 0 to 40 kg of traction in steps of 10 kg, with the exception of the pudendal canal sensor and reading of the perineal nerve sensor at 45° of hip abduction (P < .004 with Bonferroni correction for significant values). On the contrary, hip abduction angle had no statistically significant effect on pudendal nerve compression. (All specific P values with Bonferroni correction were greater than .003.) CONCLUSIONS: To avoid nerve palsy completely, the etiopathogenesis of compressive neuropathy should be identified. The location for compression and relation between different traction positions and forces are clarified in this study. This information can be used for further research and prevention. CLINICAL RELEVANCE: This study adds objective data on the etiopathogenesis of pudendal nerve compression, which potentially contributes to prevention of pudendal nerve palsy as a common complication of hip arthroscopy.

Hip arthroscopy distraction without the use of a perineal post: prospective study.

Hip arthroscopy is being used with increasing frequency as the understanding of arthroscopic management of groin pain improves. To access the hip joint arthroscopically, traction must be placed on the leg. In most cases, countertraction is provided with a padded post in the groin. Complications of traction are often attributed to the post and include perineal or pudendal neuropraxias and skin complications. The purpose of this study was to investigate the safety of a traction technique that avoids a perineal post. A supine position is used with the foot in a standard traction boot. The patient is moved down the table such that his or her perineum is located 7 to 10 cm proximal to the traction post. The post is also located 5 to 10 cm lateral to midline. The operative table is placed in 15° to 20° of Trendelenburg. With this position, enough friction is generated between the patient's upper body and bed to allow successful hip distraction without the post contacting with the perineum. One hundred seventy patients (111 men and 59 women) were followed prospectively and evaluated for possible side effects of this traction technique immediately postoperatively and 1 and 14 days and 3 and 6 months postoperatively. Patients were examined at each visit. No significant complications related to traction occurred during follow-up. The described technique has been used in more than 2000 hip arthroscopies without a documented groin or perineal complication. It allows easy positioning and access to the central compartment.