Incidence of Nerve Injury After Hip Arthroscopy

Michael J. Kern, MD; Ryan S. Murray, MD; Thomas I. Sherman, MD; William F. Postma, MD


J Am Acad Orthop Surg. 2018;26(21):773-778. 

In This Article

Abstract and Introduction


Introduction: Hip arthroscopy is a commonly performed procedure that carries a notable risk of nerve injury secondary to port placement and the use of axial traction. Sensory neurapraxia of the pudendal nerve and the lateral femoral cutaneous nerve is most common; however, sexual dysfunction and sciatic nerve injury has also been reported. Reported incidence of nerve injury ranges between 1.4% and 5% in the literature, but much of these data are based on unsolicited patient concerns. This study aimed to determine the true rate of nerve injury among this patient population through administration of a validated survey at multiple time points.

Methods: A prospective study of all patients undergoing hip arthroscopy requiring traction by a single surgeon at our institution was performed. These cases were the first 100 hip arthroscopies performed in practice by the surgeon. Before surgery, all patients were asked about the presence of neuropathic symptoms including sexual dysfunction through administration of a validated questionnaire. The same questionnaire was then administered at several time points postoperatively: on the day of surgery, on postoperative day 2, at the first follow-up visit, and if symptoms persisted, then at each follow-up appointment until resolution of the symptoms. Overall incidence of nerve injury was then calculated. Subgroup analyses were performed to investigate whether traction time, sex, body mass index (BMI), or technically demanding surgical skills affected the incidence.

Results: This study included a total of 100 patients with an average age of 29 (13 to 62) years and an average BMI of 25. Nerve injury was seen in 13 patients with an incidence of 13%. Specific nerves injured included the pudendal (9), lateral femoral cutaneous (2), sciatic (1), and superficial peroneal nerves (1). Subgroup analysis did not demonstrate a notable association between the risk of nerve injury and increased traction time, sex, or increased BMI. The technically demanding surgical skills was associated with a notable decrease in the traction time, but no notable difference in the risk of nerve injury was observed. Most nerve injuries resolved within 2 weeks (8 of 13), and all cases of nerve injury resolved within 9 months.

Discussion and Conclusions: The incidence of nerve injury after hip arthroscopy may be markedly higher than previously reported; however, resolution seems to occur as previously found in the literature. Patients should be educated regarding the risk of nerve injury during this procedure.


In the last several decades, hip arthroscopy has emerged as an increasingly popular treatment option for a variety of hip disorders.[1] Intra-articular loose bodies, labral or chondral pathology, and femoroacetabular impingement are some of the most common pathologies addressed with arthroscopic treatment. Multiple outcome studies have reported generally good results with low complication rates for these indications.[2] Consequently, the number of hip arthroscopy procedures performed in the United States has tremendously increased in the past several decades, and most studies report upward of a 500% increase over a 5- to 10-year period.[3–5] Nonetheless, hip arthroscopy remains a technically challenging procedure. Access to the hip joint is difficult and routinely requires lower extremity traction against a perineal post. The large muscles that cross the hip joint resist distraction and limit access with typical arthroscopic instruments. Six reported complication rates for hip arthroscopy vary tremendously. Most studies report rates between 0.5% and 6%,[6–8] but others have reported rates as high as 27%.[9]

Nerve injury is the most commonly reported complication in most studies, comprising 52.8% of reported complications.[10] Neurapraxia commonly occurs in the sciatic, pudendal, and lateral femoral cutaneous nerve distributions. In the cases of sciatic and pudendal nerve injury, the injury is attributed to longitudinal traction. Lateral femoral cutaneous nerve injury is attributed to direct injury by portal placement or stretch from fluid extravasation. Fortunately, most cases are transient; however, permanent injury has been reported.[11] Because most cases of nerve injury are transient, the inclusion of neurapraxia as a complication is inconsistent in many series. Historically, limiting traction time to <2 hours has been advocated to reduce the risk of nerve injury, although this precaution is extrapolated from studies involving tourniquet usage in the lower extremity, not specifically traction.[12,13] Limiting the weight of total traction to <23 kg has also been recommended.[14] Patient positioning may also have an effect, as some authors have observed a higher rate of sciatic nerve injuries in the lateral position, versus a higher rate of pudendal nerve injury in the supine position.[15]

This study sought to accomplish two primary goals: first, to determine the true incidence of nerve injury in a single surgeon learning hip arthroscopy and, second, to identify factors that contribute to the risk of nerve injury, including surgeon experience/surgical skills, patient factors, and technical details such as traction time.