Orthopaedic surgeons are increasingly performing arthroscopic surgeries of the hip in hospitals and surgery centers in the United States. Like many arthroscopic procedures, the complication rates of these minimally invasive surgeries have been thought to be very low. But do arthroscopic hip surgeries have higher risks than we previously believed?

A study presented recently at the American Orthopaedic Society for Sports Medicine’s Specialty Day in Chicago shows that these surgeries do in fact have notable complications and risks.

Cam impingement of the hipChristopher Larson, M.D. and others collected data from hip arthroscopies performed at three centers between January 2011 and April 2012. In all, 532 primary hip arthroscopies and 41 revision surgeries were performed and analyzed. All of the surgeries were done by surgeons who perform a high volume of hip arthroscopies.

Overall, the authors found a complication rate of 7.2%. By far the most common adverse finding was a sensory disturbance of the lateral femoral cutaneous nerve, which was noted in 22.7% of patients. Interestingly the sensory deficits around the portal or along the anterolateral thigh were usually observed by the surgeons but not noticed by the patients themselves. They resolved spontaneously in all but 0.7% of patients.

Due to the high incidence, the authors argue that this should be considered a sequelae, and not a complication, of arthroscopic hip surgeries.

Other complications observed by the surgeons included four thromboembolic events, two superficial wound infections, and five pudendal nerve neurapraxias.

Using a grading system designed and validated for hip surgery, the authors noted that 5.8% of patients had a grade 1 complication that required no change of postoperative management. 0.7% of patients experienced grade 2 complications requiring a change in postoperative treatment. 0.35% each had either grade 3 (requiring surgical or radiologic intervention) or grade 4 (long-term morbidity) complications.

Larson summarized his groups findings. “The overall complication rate after hip arthroscopy was 7.2 percent which is higher than what has been previously reported in the literature at 1.5 percent. These procedures were performed by relatively high volume, experienced hip arthroscopists, and we feel this rate represents a reasonable comprehensive complication rate with the current techniques and indications for hip arthroscopy.”

MRI of a hip labral tearWhile the rates of adverse events from hip arthroscopies in this study – both complications and sequelae – are higher than those reported in earlier papers, they probably reflect a true rate. Surgeons currently perform more complex procedures, such as labral repairs, and not simply labral debridements. In addition, these procedures were performed by experienced arthroscopists who would be expected to have some of the lowest rates of complications performing them.

Fortunately most of these events resolved quickly. The sensory disturbance around the portals or on the front and outside of the thigh occurred frequently enough that surgeons might consider advising patients of that occurrence routinely. Much like the numbness patients feel around the incisions to harvest the graft during ACL reconstructions, the nerve issues here might not be serious, but patients might benefit from the explanation.

While the sex, body mass index, and primary versus revision nature of the surgery did not correlate with the occurrence of complications, surgical time and the operative time with the hip in traction did. Lengthy traction on the hip would seem to make a stretch injury to the nerves in the area more likely. On the other hand, increased surgical times and traction times might indicate more complicated procedures, possibly involving stiffer joints or more advanced damage. Higher complications in these more difficult cases shouldn’t be surprising.

In summary, newer hip arthroscopic surgeries have given orthopaedic surgeons the ability to treat more complex pathology with less surgical trauma than ever before. This study offers patients and health care professionals a framework of expected risks with these surgeries.

Note: The following post is modified from an article I wrote for Becker’s Orthopedic Review.