Hip arthroscopy has been one of the fastest evolving orthopaedic surgeries of the past few decades, with incidence rates increasing upwards of 600% (Reiman, 2015). Due to higher rates of FAI, labrum tears, and chondrolabral damage, more and more athletes and active individuals are opting for hip arthroscopy (Reiman et al., 2016). Most will undergo surgery due to pain and dysfunction that is affecting their daily activities and/or sport performance, with high hopes of returning to playing afterwards. These procedures have been shown to be effective at restoring function and decreasing pain with high satisfaction (Philippon et al., 2017), but how effective are they at restoring sporting performance to pre-injury levels?
High Return to Sport Rates After Hip Surgery
Overall, the return to sport rate after hip arthroscopy typically ranges from 80-90% (Weber et al., 2017; Casartelli et al., 2015), which is very good. Multiple studies have shown these high rates across a range of athletes including recreational, high school, collegiate, and professionals. However, just because the return to sport rate is high does not mean that all return to the same level of play. A systematic review by Casartelli et al (2015) found that 87% of athletes ranging from recreational to professional returned to sport and 82% of athletes returned to the same caliber of sport. Further, some athletes weren’t completely satisfied with their surgical outcomes. Casartelli (2015) also cited multiple studies that showed high percentages of return to sport in the short term but drop off ranging from 5%-19% within 3 years post-surgery in professional athletes. This could be related to the degree of cartilage damage in the hip prior to surgery, as showed in another study where they found a drop off rate of 30% over 3 years in professional athletes who underwent hip arthroscopy with microfracture (MacDonald et al., 2013). This suggests that although there is a high short term rate of return to sport, the long term return to sport rate may not be as such.
Limited Evidence of Return to Performance After Hip Surgery
Looking deeper into the high rates of athletes returning to sport reveals some discrepancies that could cloud these high rates. Reiman et al (2018) did a systematic review of return to sport participation and return to sport at previous level in patients after FAI surgery. They found that 91% of athletes who underwent hip surgery for FAI returned to sport but only 74% of athletes returned to their preinjury level of sport. Additionally, very few studies they looked at actually measured athlete performance in those who do return to preinjury level of play. In other words, they found that when looking at return to sport there are high rates of return, when looking at return to previous level of sport those rates decrease, and when looking at return to previous level of performance there is minimal evidence to demonstrate whether or not players are successful in this.
Ishoi et al (2018) also looked at rates of return to preinjury level of sport using a nationwide hip arthroscopy database. They found that 57% had returned to their previous level of sport and less than 30% reported feeling that they were performing at an optimal level. Of those who reported optimal performance, one athlete reported reaching optimal performance in less than 1 year. The majority of others who reached this subjective optimal performance levels did so between 1-3 years after surgery. Over 80% of the athletes who were not able to play at their preinjury level attributed the cause to hip and groin pain. As previously mentioned, this was thought to possibly be caused by greater degenerative damage of the cartilage. The authors also discuss the fact that only one athlete reported optimal performance at preinjury level in less than one year, while surgeons will typically recommend return to sport in 3-5 months. This could be because the majority of participants may still have deficits within one-year post-op. In another study, Casartelli et al (2014) found hip flexor strength deficits 2.5 years after surgery in a small sample of FAI patients. As you’ll see below, athletes can show deficits in ROM, strength, and other performance characteristics up to almost one-year post-op.
These two studies (Reiman et al 2018; Ishoi et al 2018) describe findings that differ from those of previous literature (Weber et al., 2017; Casartelli et al., 2015). This is most likely due to more consistent and stricter return to sport criteria, whereas the criteria used in previous research has varied significantly or wasn’t reported (Reiman et al, 2018).
Interestingly, Sochaki et al (2019) and MacDonald et al (2014) looked at player performance after return from hip arthroscopy for FAI in NHL players. They found no difference in performance metrics such as goals, assists, points, etc., when the players returned, however, players who underwent the surgery had shorter careers on average by about 1 season. No reasons for retirement were given, leaving the possibility of the cause of retirement attributable to reasons other than hip health, like player age. It is also arguable that without the surgery, it’s likely that the player would have had to retire sooner and that having the surgery may have added a few years to their career. With an average return to sport time of 6.8 months, it raises the question that if athletes waited a little longer before returning, could their playing career be extended even more?
Ideal Time to Return to Sport After Hip Surgery
Most studies that I’ve read show return to sport between 6-8 months (Weber et al., 2017; Reiman et al., 2018; Sochaki et al., 2019; Worner et al., 2019). One study showed positive correlations between the time from stopping sport to surgery and time to return to sport (Weber et al., 2017). In other words, those who stopped playing their sport 8 months or longer before surgery had longer times for return to sport than those who stopped playing less than 8 months before surgery. Longer preoperative withdrawal from sport also correlated to worse subjective function scores 2 years post-op. There was no indication of the reason why athletes stopped playing when they did, but it seems logical to think that it would be from an increase in pain or decrease in daily function. This would suggest that longer duration of severe symptoms and dysfunction leads to longer rehab, later return to sport and worse overall subjective outcome, which have also been suggested to possibly be related to greater cartilage degeneration (Ishoi et al, 2018).
Worner et al. (2019) looked at hip function 6-10 months after arthroscopic hip surgery in a group of 33 patients compared to 33 controls. The researchers looked at both subjective and objective measures of hip function (i.e. HAGOS, hip strength, ROM, Y-balance test, lateral hop, and Illinois Agility tests). They found that those who underwent surgery had worse post-op subjective hip function scores than the control group, similar to other studies measuring post-op patient satisfaction. This finding suggests that even between 6-10 months post-op, patients are not back to their “normal” function. The objective tests showed minimal differences between the affected and unaffected sides but comparing surgical group to control group showed significantly lower scores in the surgical group for all hip motions, hip flexion strength and posteriomedial portion of the Y-balance test. This suggests that hip ROM, strength, and control may still be limited 6-10 months after hip surgery. Unfortunately, there was no mention of measurements for hip extension and abduction, which play a large part in walking, running, and skating. However, if trends in reported hip function persisted with abduction and extension, this could explain the low subjective function scores. These results demonstrate that although athletes had symmetrical strength, ROM and other performance characteristics, they still had decreased hip performance in the same tests when compared to a control group. To me, this suggests potential issues in relying on limb symmetry index (LSI) for return to sport decisions in hip rehab.
LSI has become a common measure of an athlete’s readiness for return to sport thanks to a lot of the research in post-op ACL athletes. Making sure athletes have symmetrical strength and range of motion is absolutely necessary for return to sport, but it’s only a portion of what is required to return to high levels of performance. Consider that since surgery, the non-surgical limb is not likely being loaded as much as it was before with the majority of the focus during the rehab process on the injured side. It would be naïve to expect the unaffected side to still be in the same condition as it was before surgery. Also, consider that symmetry testing often consists of strength and ROM tests, hop tests, balance tests and sometimes an agility test. The intensities of these tests do not match the intensity of practices and games on the ice. By relying heavily on LSI in determining readiness to return to sport, we may overestimate a player’s ability and readiness to return. Adding further performance tests to measure off-ice performance progress or specific on-ice tests (if possible) will paint a clearer picture of an athlete’s ability and readiness to return. Such tests could include upper body strength and power tests, timed sprints, repeat sprint ability, and aerobic capacity tests. This information would show a broader scope of return to sport readiness through comparison to a pre-surgical baseline score or normative scores if no baseline is available, while bringing out potential compensation strategies during high intensity tasks in a fatigued state.
Based on these findings, it is clear we still have a lot to learn about the effect of hip arthroscopy and post-op rehabilitation on athlete performance and career longevity.
Some concluding thoughts/questions:
- Although surgery is often successful in decreasing pain and improving function, is it improving function enough for players to excel in their sport after surgery? But in the same breath, surgical intervention may be adding years to an athlete’s career albeit not at their optimal performance. Discussing this with the athlete should occur prior to surgery, making it clear that if they want to continue to play it may not be at the same level. But maybe we’re also doing a poor job in rehab at correcting moving compensations from months of pain and dysfunction, increasing athlete confidence in their hip and improving post-op function prior to allowing them to return to sport. Without using a rigorous battery of tests to expose the athlete to high intensity activity that matches the sport, we may be missing some details that could lead to better return to sport.
- Is 6-8 months long enough for rehab? Considering the gradual build-up of pain and dysfunction often for several months prior to surgery—which can lead to compensation patterns—as well as restrictions in activity for several months post-op, perhaps a longer rehab timeline would lead to better return to performance outcomes. Additionally, if between 6-10 months post-op athletes still have limitations in ROM, strength and control as well as lower self-reported hip function, are they mentally and physically prepared to return to sport?
- LSI is important but only a portion of the return to sport decision. It provides information on individual symmetry but not on physical preparation for return to sport. Thus, LSI should be a part of a larger cluster of tests used in the decision making for return to sport of hockey players.
- As practitioners, we have to educate players, parents, maybe even surgeons on the potential benefits of early intervention on return to sport and performance. From my experience both as a player and rehab practitioner, a lot of players will play through hip pain thinking it’s “normal”. When in fact, any kind of pain is not normal: it’s your body telling you there’s something going on that it doesn’t like. Early conservative interventions can help improve strength and optimize movement, manage symptoms and possibly delay severe symptoms and dysfunction. However, early surgical interventions could also be beneficial in slowing the degeneration of the hip joint rather than waiting until the athlete is forced to stop playing from pain and dysfunction. So, there may be a fine line where opting for surgery after conservative interventions may be optimal for post-operative performance.