Effects of Hip Arthroscopy Without a Perineal Post on Venous Blood Flow, Muscle Damage, Peripheral Nerve Conduction, and Perineal Injury: A Prospective Study

Abstract

Background: Prior reports of hip arthroscopy using a perineal post have established the risks of groin soft tissue injury, sexual dysfunction, and altered lower extremity neurovascular function. These parameters have not been investigated for hip arthroscopy without the use of a perineal post. Purpose: To evaluate the effects of postless hip arthroscopy on lower extremity venous blood flow, nerve conduction, muscle tissue damage, and perineal injury. Study Design: Case series; Level of evidence, 4. Methods: Patients between the ages of 18 and 50 years undergoing an elective unilateral or simultaneous bilateral hip arthroscopy were enrolled. Creatine phosphokinase (CPK)–MM levels and D-dimer levels were obtained preoperatively, immediately postoperatively, and 7 to 12 days postoperatively. Bilateral Doppler ultrasonography of the common femoral vein (CFV) and popliteal vein were conducted intraoperatively. Somatosensory evoked potentials (SSEPs) and transcranial motor evoked potentials (TcMEPs) were measured intraoperatively for the lower limbs. Perineal injury was assessed at 7 to 12 days postoperatively. Results: 35 patients underwent a total of 40 hip arthroscopies. No significant differences were found in venous blood flow between the operative and nonoperative legs for either the CFV or popliteal vein. SSEP monitoring of the peroneal nerve showed no significant reduction when traction was applied to the operative leg, 90.8%, compared with final measurement just before it was removed, 72.4% (P = .09). For TcMEPs measured in the muscles outside of the traction boots, no significant changes were seen in the percentage of cases with abnormal measurements throughout the procedure. CPK-MM levels preoperatively, immediately postoperatively, and 7 to 12 days after surgery were on average 112, 190, and 102 IU/L, respectively (normal, <156 IU/L). No significant relationship was found between abnormal venous flow and altered D-dimer levels. No clinical evidence of nerve or vascular injury was encountered, and no groin soft tissue complications were observed during the study period. Conclusion: Postless hip arthroscopy is safe, without a notable reduction of venous blood flow or alteration of nerve function in the operative leg. Muscle tissue damage is subclinical, transient, and reduced compared with distraction with a post. No cases of perineal injury were observed during the study period.