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Fig. 1 This radiograph shows cam-type femoroacetabular impingement in an airborne soldier.
Courtesy of Lt. Col. Sean P. Kearney, MD, MPH

AAOS Now

Published 9/3/2021
|
Ariel DeMaio

Study Highlights How Residual Hip Dysfunction Can Challenge Servicemembers’ Return to Duty

Only one-third of active-duty servicemembers treated arthroscopically for hip pathology had a full return to duty, according to a prospective cohort study. Patient-reported outcomes improved postoperatively; however, half of the study participants were medically discharged, said study author Lt. Col. Sean P. Kearney, MD, MPH. Dr. Kearny, orthopaedic surgeon at Womack Army Medical Center, will present the findings today.

The results contrast with previous studies and suggest that active-duty servicemembers and general athletes should be counseled that hip arthroscopy can improve overall function but that return to duty and sports can be challenging.

Fig. 1 This radiograph shows cam-type femoroacetabular impingement in an airborne soldier.
Courtesy of Lt. Col. Sean P. Kearney, MD, MPH
Table 1 Average pre- and postoperative patient-reported outcome measures
Courtesy of Lt. Col. Sean P. Kearney, MD, MPH

“At Fort Bragg, N.C., home of the 82nd Airborne and Special Operations Forces, hip pain, particularly femoroacetabular impingement, is rampant among the young, active-duty troop population,” Dr. Kearney told AAOS Now Daily Edition, when asked about the rationale for this study. “Hip arthroscopy became a large part of my practice, but the postoperative results were discouraging. I certainly was not seeing the 80 to 90 percent return-to-duty rates reported by retrospective hip arthroscopy studies in the military population.” Anecdotally, he said, fewer than half of his patients were returning to duty, “although most seemed subjectively happy with the surgery results,” he added.

Dr. Kearney designed the prospective cohort study to better understand the postoperative outcomes in his active-duty patients, including duty status over time and nonarthritic hip outcome measures.

The study cohort included 108 consecutive active-duty servicemembers (73 men and 35 women) who underwent hip arthroscopy for femoroacetabular impingement or repairable labrum by a single surgeon at a single military medical center from April 2016 through June 2020 (Fig. 1).

All patients completed the Non-arthritic Hip Score (NAHS), the Hip Outcome Score Activity of Daily Living Scale (HOS-ADL), and the Hip Outcome Score Sports Scale (HOS-S) preoperatively and then at standard intervals postoperatively. Duty status was recorded throughout the follow-up period.

Although there were no major surgical complications among the study population, only 36 servicemembers (33 percent) returned to active-duty status after an average follow-up of 2.1 years. Of the remaining 72 servicemembers, 15 (14 percent) returned or left the military after contract completion and two (2 percent) were discharged for improper conduct. More than half of the remaining servicemembers (51 percent) were medically discharged for inability to perform their duties in whole or in part due to postoperative hip dysfunction.

As seen in Table 1, all outcome scores improved pre- to postoperatively across the cohort.

However, the scores did not improve to levels reflecting normal hip function, Dr. Kearney noted. “For instance, the mean HOS-S only improved to 50 percent of normal, perhaps explaining the low return-to-duty rate,” he said.

In a subanalysis, Dr. Kearney found that medically discharged servicemembers were significantly younger and more likely to have a psychiatric diagnosis compared to those who returned to duty. Also, although NAHS and HOS-ADL significantly improved among medically discharged servicemembers, HOS-S remained unimproved, at only 36 percent of normal.

“This study suggests that, although patient-reported outcome scores do improve, residual postoperative hip dysfunction still prohibits most servicemembers from returning to duty,” Dr. Kearney concluded. “More broadly, the findings suggest that athletes in general may experience postoperative hip dysfunction that could impact return to play. It is recommended that active-
duty servicemembers and athletes alike be counseled that hip arthroscopy can improve overall function, but return to duty and sports can be challenging.”

Asked about potential limitations of this analysis, Dr. Kearney noted that it provides an “imperfect understanding of the true reasons why servicemembers decide to discontinue military service,” which may lead to a more negative perception of hip arthroscopy outcomes in this study. “While there are likely secondary factors that influence the decision to discontinue military service, this study assumes that the decision was due, at least in part, to residual postoperative hip dysfunction.”

The observed high prevalence of psychiatric disorders among servicemembers undergoing hip arthroscopy, particularly those who were medically discharged, also prompted Dr. Kearney to investigate the effects of psychiatric disorders in this population, which is currently ongoing.

The study will be presented today as Paper 650 at 9:25 a.m. in Ballroom 6E.

Dr. Kearney’s abstract is titled “Low Return to Active Duty after Hip Arthroscopy.”

Ariel DeMaio is the managing editor of AAOS Now. She can be reached at ademaio@aaos.org.