Functional Outcomes, Complications, and Failure Rates in Workers’ Compensation Patients Following Hip Arthroscopic Repair: A Systematic Review

Abstract

Background:

Studies on the feasibility of hip arthroscopy in workers’ compensation (WC) patients have been largely inconsistent or limited by study design, necessitating the need for a systematic review.

Purpose:

We sought to systematically compare clinically significant differences between WC patients and their counterparts in relation to (1) functional outcomes, (2) complications, and (3) failure rates after hip arthroscopy.

Methods:

We searched MEDLINE, EMBASE, and PubMed databases for studies published between January 1996 and February 2021. In combination with “AND” or “OR” Boolean operators, the following keywords were implemented: “hip arthroscopy,” “workers’ compensation,” “outcomes,” “complications,” “revision,” and “failure rates.” Two reviewers screened eligible studies, evaluated methodological quality, and abstracted data.

Results:

In the 13 studies pooled, comprising 1874 patients, 276 (14.7%) patients received WC benefits. Twelve studies utilized functional outcomes, 2 studies assessed pain, and 3 studies evaluated satisfaction. Despite scoring lower in these measures preoperatively, WC patients demonstrated significant improvements after hip arthroscopy. Three studies linked compensation with marginally inferior functional scores, but this association was not significant at longer follow-up. Seven studies examined complication incidence, and 6 studies addressed failure rates, with all reporting no significant differences in rates of complications, secondary arthroscopies, or conversion to total hip arthroplasty.

Conclusions:

The findings of this systematic review suggest that hip arthroscopy offers clinically significant benefits, regardless of WC status. Postoperative results in WC patients, including functional scores, pain, satisfaction, complications, and failure rates, were favorable, and the degree of improvement was at least comparable with their counterparts. Further studies should consider prospective study designs with larger cohorts and extended follow-up.

Introduction

Initially introduced in the 1930s by Burman [5], hip arthroscopy has experienced exponential growth over the past few decades as a minimally invasive diagnostic and therapeutic tool [4]. The reasons for its recent surge in popularity include technological advancements in surgical instrumentation and traction devices, increased exposure during the training period, and growing recognition of intra-articular hip pathologies [17]. Operative indications and surgical techniques have evolved considerably since its inception, and hip arthroscopy is now well-recognized as an attractive option to manage an expanding range of hip conditions that fail to respond to adequate non-operative therapy. The most common indications are femoroacetabular impingement, labral lesions, and loose body removal in the hip joint [20,40]. In the literature, hip arthroscopy has demonstrated substantial improvement of patient-reported outcome measures and quality of life, shorter recovery times and complication rates when compared with open surgery, and potential delays in osteoarthritis progression and need for total hip arthroplasty (THA) [15,24,32].

Identification of patient-related risk factors and appropriate patient selection are essential considerations before performing hip arthroscopy. For instance, the most favorable outcomes tend to occur in young, active patients with acute symptom onset and minimal associated chondral damage; older age, obesity, and preoperative diagnoses of chronic degenerative conditions, such as osteoarthritis and femoral head osteonecrosis, are frequently associated with poorer outcomes [23,2,25,29]. Recent studies have investigated the relationship between insurance status and patient outcomes following medical interventions. Workers’ compensation (WC) is a form of insurance providing financial and medical benefits to employees injured during employment or military duty, existing as various types in several Western countries [30]. The subset of patients with WC claims and pending litigation may be more susceptible to significantly inferior outcomes after surgery than their non-WC counterparts. For instance, Harris et al performed a meta-analysis on 211 studies assessing the role of surgical interventions in patients with active WC claims, concluding that they are 4 times more likely to experience unsatisfactory results than patients not on compensation [16]. Another meta-analysis of 20 prospective studies evaluating WC status and orthopedic surgery outcomes discovered a 2-fold greater risk of negative outcomes in compensation patients [11]. WC status has been associated with inferior outcomes after various orthopedic procedures, including total knee arthroplasty [28], rotator cuff repair [26], anterior cruciate ligament reconstruction [1], and anterior cervical discectomy and fusion [41]. Previous literature on hip arthroscopy patients receiving WC has been largely inconsistent or limited by study design, and, to the authors’ knowledge, no systematic review of studies currently exists.

Although hip arthroscopy is an effective approach to treat a wide variety of intra-articular hip pathologies, its role in the WC population remains unclear. As its utilization continues to rapidly increase, more information about the association between compensation status and hip arthroscopy outcomes is needed to facilitate appropriate patient expectations, avoid interventions with marginal or no benefit, and reduce economic burden in this subset of patients. The purpose of this review is to compare clinically significant differences between WC patients and their non-WC counterparts in relation to (1) functional outcomes, (2) complication incidences, and (3) failure rates.

This study investigates the null hypothesis that there are no differences between WC patients and their counterparts undergoing hip arthroscopic repair. The authors hypothesized that WC patients would report inferior functional outcome scores, but no clinically significant differences would be observed in complication and failure rates, suggesting that hip arthroscopy nonetheless offers benefit regardless of compensation status.

Methods

This systematic review was conducted according to the methodology described in the Cochrane Handbook for Systemic Reviews of Interventions, and findings are reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement [9,27] (Fig. 1).

Fig. 1.

Preferred reporting items for systematic reviews and meta-analyses flow diagram.

Studies eligible for inclusion were assessed for the following criteria: (1) full-text English manuscript was accessible, (2) studies utilized controlled prospective or retrospective designs, and (3) studies reported on outcomes, complications, and failure rates in WC patients following hip arthroscopy. In addition, studies were excluded if they were not objective (eg, surveys), evaluated only non-operative treatment, involved orthopedic procedures other than hip arthroscopy, were cadaveric studies, or did not investigate the role of compensation status on the clinical results of hip arthroscopy.

An electronic search of 3 online databases (EMBASE, MEDLINE, and PubMed) was conducted beginning from database inception until the search date of February 1, 2021. Related references and cited articles were manually retrieved to increase sensitivity and capture any additional relevant studies for inclusion that may have been missed by the initial search strategy. The following key terms were used in the search, in combination with “AND” or “OR” Boolean operators: “hip arthroscopy,” “workers’ compensation,” “outcomes,” “complications,” “revision,” and “failure rates.”

After the literature search and duplicate removal, 2 researchers independently queried all titles and abstracts to identify eligible studies based on predefined criteria. Potentially eligible studies were reviewed in full text by both researchers for final inclusion. Any disagreements about study inclusion were resolved by consensus between the 2 reviewers. If consensus could not be met, a senior author was consulted to resolve any discrepancies and determine if the study met inclusion-exclusion criteria.

Two reviewers completed a quality assessment of all the included studies using the Methodological Index for Non-Randomized Studies (MINORS) criteria [38]. Methodological Index for Non-Randomized Studies is a validated scoring tool for non-randomized surgical studies (eg, case reports, case series, cohort studies, etc.). Each of the 12 items in the MINORS criteria is given a score of 0, 1, or 2; maximum scores of 16 and 24 can be achieved for non-comparative and comparative studies, respectively. The level of evidence was also documented.

Two reviewers independently abstracted relevant study data from the final pool of included articles. An electronic spreadsheet was created and populated with the descriptive and outcome variables under investigation as headings (eg, author, year of publication, sample size, patient demographics, study design, etc.) Any data on patient-reported outcome measures, complication incidence, and failure rates were tabulated. Data were pooled from each study, and any discrepancies were resolved by consensus between the 2 reviewers.

Statistical Analysis

A weighted kappa coefficient was calculated for inter-rater agreement between reviewers after assessment of study eligibility. The interpretation is as follows: kappa values ≤ 0 interpreted as no agreement, 0.01 to 0.20 as none to slight agreement, 0.21 to 0.40 as fair agreement, 0.41 to 0.60 as moderate agreement, 0.61 to 0.80 as substantial agreement, and 0.81 to 1.00 as near perfect agreement. Inter-rater agreement the reviewers’ assessment of study methodological quality was calculated using the intraclass correlation coefficient. Forest plots were created using the OpenMetaAnalyst statistical software and were utilized to aid in the visualization of patient-reported outcome scores for both WC and non-WC cohorts.

Results

All included studies were either case series or case-control studies, with the majority level IV evidence (n = 8, 62%) and the remainder level III evidence (n = 5, 38%). The final mean MINORS score was 16 (range: 12-21), indicating a high quality of evidence. There was excellent agreement among quality assessment scores of included studies, with an intraclass correlation coefficient = 0.97 (95% confidence interval [CI] 0.95-0.99).

The initial search yielded a total of 353 potentially relevant studies, of which 13 studies met the inclusion and exclusion criteria for this review (Fig. 1). All included studies were conducted between 1999 and 2020. This included a total of 1874 patients, of whom 276 (14.7%) patients received WC. The mean sample size in the included studies was 144 (range: 28 -935) patients. Of the patients treated across the studies, 58% were male, with a mean age of 34.3 (14-84) years and mean follow-up time of 38.7 (24-120) months; 4.3% of patients were reported as being lost to follow-up across all studies. Study characteristics are presented in Table 1.

Table 1.

Characteristics of included studies.

Author	Workers’ compensation patient cohort size (total patients studied)	Age at surgery, mean (range) or mean ± SD	Study design	Mean follow-up (months)	Surgical side	Variable measured	Summary of findings	MINORS score	LOE
Byrd and Jones [7]	8 (35)	38 (15–84)	Prospective case series	24	20L/18R	mHHS	WC cohort exhibited better trends in clinical outcomes at 2-year follow-up, although without statistical significance	14	IV
Byrd and Jones [6]	16 (50)	38 (15–84)	Prospective case series	120	28L/24R	mHHS	At 10-year follow-up, no significant difference was found in functional outcomes between the WC and non-WC cohorts	15	IV
Cvetanovich et al [10]	14 (386)	33.3 ± 12.1	Prospective case-control study	31	Not reported	HOS-ADL HOS-SSS mHHS	Within a 2-year follow-up period, WC patients exhibited statistically significant improvements in but lower functional scores compared with patients without WC status	17	III
Domb et al [12]	12 hips (of 47 hips total)	37.1 (16–70)	Case series	29	28R/19L	VAS mHHS NAHS HOS-ADL HOS-SS	At 3-year follow-up, Workers’ Compensation status was shown to be a negative predictive factor with poorer functional outcomes, although not statistically significant	15	IV
Farjo et al [13]	8 (28)	41 (14–70)	Case series	34	17L/11R	Pain ADLs	No statistically significant correlation was observed between patient-reported outcomes and WC status, at 3-year follow-up	16	III
Gigi et al [14]	33 (106)	32.0 ± 1.9	Retrospective comparative study	33	Not reported	mHHS HOS	At minimum 1-year follow-up, WC patients reported the lowest extent of improvement in functional outcomes (statistically significant for mHHS, but not for HOS)	16	III
Kamath et al [18]	8 (52)	42 (25–76)	Prospective case series	58	33R/19L	mHHS	At minimum 2-year follow-up, WC status had a negative effect on patient-reported outcome, although not statistically significant. WC patients were significantly less likely than their counterparts to return to prior activity levels	17	IV
Lee et al [22]	29 (vs age-gender-matched controls)	39.1 ± 9.94	Retrospective case-control study	25	Not reported	HOS-ADL HOS-SS mHHS Return to work status	At 1-year follow-up, WC patients exhibited significantly lower patient-reported outcomes (HOS-ADL and HOS-SS) as compared with age-gender-matched controls	18	IV
Nho et al [31]	46 (935)	33.3 ± 12.3	Prospective case-control study	28	Not reported	VAS pain HOS-ADL HOS-SS mHHS iHOT-12	At minimum 2-year follow-up, WC status was demonstrated to be a statistically significant predictor for inferior clinical outcomes	18	III
Perets et al [33]	42 hips (vs age-gender-BMI-matched controls)	40.6 ± 10.6	Prospective case-control study	60	Not reported	mHHS NAHS HOS-SS iHOT-12	At minimum 5-year follow-up, no significant difference was found in patient-reported outcomes and satisfaction rates when comparing WC patients with their counterparts. In fact, magnitude of postoperative improvement was significantly higher in the WC cohort	21	IV
Potter et al [34]	14 (33)	32.9 (21–56)	Case series	25	Not reported	SF-36 mHHS Patient satisfaction	At 2-year follow-up, significantly inferior patient-reported outcomes (mHHS, SF-36, and satisfaction rates) were reported in patients with disability status	12	IV
Salvo et al [35]	26 (56)	43 (25–58)	Prospective case-control study	18	Not reported	mHHS HOS	Postoperative functional outcomes as measured by Hip Outcome Score were significantly inferior in the WC cohort at mid-term follow-up. No statistically significant difference in modified Harris Hip Score was observed	18	IV
Stake et al [39]	21 hips (vs age-gender-diagnosis-matched controls)	39 (24–55)	Prospective case-control study	24	Not reported	mHHS NAHS HOS-ADL HOS-SSS VAS pain	At 2-year follow-up, both WC and control cohorts demonstrated statistically significant postoperative improvement in all functional outcomes. The control group exhibited significantly superior extent of improvement only for HOS-ADL. No significant difference between cohorts for mHHS, NAHS, HOS-SSS, and pain	20	III

SD standard deviation, MINORS Methodological Index for Non-Randomized Studies, LOE level of evidence, mHHS modified Harris Hip Score, WC workers’ compensation, HOS Hip Outcome Score, HOS-ADL Hip Outcome Score—Activities of Daily Living, HOS-SS Hip Outcome Score—Sport-Specific Subscale, VAS Visual Analog Scale, NAHS Non-Arthritic Hip Score, iHOT-12 International Hip Outcome Tool, SF-36 Short Form-36.

The most common patient outcome tool was the modified Harris Hip Score (mHHS), with all studies except for Farjo et al [13] using it in their analysis. All studies reported postoperative mHHS, although there was some inconsistency across studies regarding the reporting of preoperative mHHS. Nine studies directly compared mHHS between WC and non-WC cohorts, as presented in Table 2. To assess the clinical significance of these scores, we used thresholds established by the Minimal Clinically Important Difference (MCID) and the Patient Acceptable Symptomatic State (PASS) values available in the hip preservation literature. Notably, for hip arthroscopic repair, MCID was defined to by 8 by Kemp et al [19] and PASS was defined to be 74 by Chahal et al [8].

Table 2.

Mean modified Harris Hip Score in workers’ compensation and non-workers’ compensation cohorts.

Study	Measurement	Workers’ compensation (range if available)	Non-workers’ compensation (range if available)	Significance
Nho et al [30]	Preoperative	57.4	57.7	P = .863
	Postoperative	67.4	81.4	P < .0001
	Patients reporting good/excellent outcomes	0%	68%	Not provided
Perets et al [33]	Preoperative	46.1	67.7	P < .001
	Postoperative	80.2	82.0	P = .416
	Improvement	+34.1 (P < .001)	+14.2 (P < .001)	P = .001
Lee et al [22]	Preoperative	43.0	61.2	P < .001
	Postoperative	69.3	78.6	P = .011
	Improvement	+26.3 (P < .001)	+17.4 (P < .001)	Not provided
Salvo et al [35]	Postoperative	72.5	75.6	P = .9
Gigi et al [14]	Preoperative	59.6 (52–67)	64.6 (59–69)	P < .001
	Postoperative	64.9 (52–73)	73.9 (67–81)	P = .125
	Improvement	+5.3 (P < .001)	+9.3 (P < .001)	P = .563
Stake et al [39]	Improvement	+21.7 (P < .001)	+17.9 (P < .001)	P = .534
Byrd and Jones [7]	Postoperative	89	81	P > .05

<70 = poor result; 70–80 = fair; 80–90 = good; 90–100 = excellent. Significant outcomes bolded within table.

A total of 5 studies reported no significant difference in mHHS between WC patients and their counterparts not receiving compensation. In their analysis, Gigi et al [14] showed that WC patients tended to score significantly lower preoperatively on the mHHS compared with their counterparts (59.6 vs 64.6, P < .001). However, scores between the 2 groups after hip arthroscopy did not show a significant difference (64.9 vs 73.9, P = .125). Hip arthroscopy offered significant improvements in the postoperative mHHS for both groups (P = .042 in WC group and P = .01 in non-WC group). Moreover, the authors demonstrated that there was no significant difference in the magnitude of improvement between WC and non-WC patients (+5.3 vs +9.3, P = .563). Comparatively, hip arthroscopy achieved MCID in the WC cohort but failed to do so in the non-WC cohort; neither cohort seemed to achieve a favorable PASS score. In a similar vein, Perets et al [33] showed that although WC patients scored lower at preoperative baseline (46.1 vs 67.7, P < .001), results after surgery were not significantly different between the 2 groups (80.2 vs 82.0, P = .416). In this study, both cohorts achieved a favorable PASS score after hip arthroscopy. In fact, the WC cohort exhibited a significantly greater magnitude of improvement following hip arthroscopy (34.1 vs 14.2, P = .001), far surpassing the MCID. Byrd and Jones [7] also demonstrated no significant differences in mHHS based on compensation status. Interestingly, WC patients scored higher postoperatively than their non-WC counterparts (89 vs 81), although this metric did not reach statistical significance. In their extended 10-year follow-up, the authors again demonstrated no significant difference between the 2 groups (73 vs 81, no P value reported) [6]. The magnitude of improvement was slightly lower in patients receiving compensation (+20 vs +25) thereby achieving MCID, although this difference was insignificant. Similarly, Salvo et al [35] found no significant difference in mHHS between WC and non-WC cohorts at 2-year follow-up (72.5 vs 75.6, P = .9). Finally, Stake et al [39] found that surgery offered significant improvements in mHHS in both groups: +21.7 (P < .001) in WC patients and +17.9 (P < .001) in non-WC patients. The magnitude of improvement was not found to be significantly different between the 2 cohorts (P = .534), and both cohorts achieved MCID.

A total of 3 studies found a significant difference in mHHS when comparing compensated and non-compensated patients. Lee et al [22] showed that although WC patients improved significantly following hip arthroscopy and achieved MCID (+26.3, P < .0001), they scored lower than their counterparts (69.3 vs 78.6, P = .011) and failed to achieve PASS. Nho et al [30] also reported significantly higher postoperative mHHS in patients not receiving compensation; although both cohorts scored similarly before surgery (57.7 vs 57.4, P = .863), WC patients tended to perform more poorly after surgery (67.4 vs 81.4, P < .001). Likewise, Potter et al [34] reinforced these findings by showing that military personnel undergoing evaluation boards (the military’s equivalent to WC or disability claim) performed significantly lower than their counterparts after hip arthroscopy (61.1 vs 92.4, P < .0001) with failure to achieve PASS. The authors additionally reported that 0% of compensated patients reported good/excellent outcomes, compared with 68% of their non-compensated counterparts. Fig. 2 demonstrates a forest plot of overall postoperative mHHS for each cohort, (I² = 95.3%, P < .001 and I² = 82.6%, P < .001 for WC and non-WC patients, respectively)––suggesting significant heterogeneity in reporting of this outcome measure.

Fig. 2.

Forest plot illustrating overall postoperative mHHS patient-reported outcomes in WC and non-WC patients. mHHS modified Harris Hip Score, WC workers’ compensation, CI confidence interval.

A total of 8 studies reported the Hip Outcome Score, some using both instruments: Hip Outcome Score—Activities of Daily Living (HOS-ADL) and Hip Outcome Score—Sport-specific subscale (HOS-SS) [14,22,33,35,39]. For HOS, published thresholds for MCID and PASS are 9 and 77, respectively, as established by Nwachukwu et al [31]. Five studies documented and directly contrasted HOS scores between WC and non-WC cohorts (Table 3).

Table 3.

Mean Hip Outcome Score (HOS) in workers’ compensation and non-workers’ compensation cohorts.

Study	Subscale, if used	Measurement	Workers’ compensation (range if available)	Non-workers’ compensation (range if available)	Significance
Gigi et al [14]	HOS	Preoperative	59.3 [52–67]	67.2 [60–74]	P = .176
		Postoperative	69.4 [60–78]	77.9 [71–85]	P = .24
		Improvement	+10.1 (P = .001)	+10.7 (P = .007)	Not significant
Salvo et al [35]	HOS	Postoperative	66.5	89.4	P = .003
Perets et al [33]	HOS-SS	Preoperative	18.1	51.2	P < .001
		Postoperative	66.5	69.7	P = .71
		Improvement	+48.3 (P < .001)	+18.4 (P < .001)	P = .002
Lee et al [22]	HOS-ADL	Preoperative	46.5	69.2	P < .0001
		Postoperative	76.8	89.9	P < .0001
	HOS-SS	Preoperative	25.4	43.6	P = .025
		Postoperative	64.7	79.2	P = .001
Stake et al [39]	HOS-ADL	Preoperative	39.7	69.8	P < .001
		Postoperative	69.5	80.9	P < .001
		Improvement	+29.8 (P < .001)	+11.1 (P < .001)	P = .0429
	HOS-SS	Preoperative	15.3	41.9	P < .001
		Postoperative	49.8	73.8	P < .001
		Improvement	+34.5 (P < .001)	+31.9 (P < .001)	P = .0642

HOS Hip Outcome Score, HOS-ADL Hip Outcome Score—Activities of Daily Living, HOS-SS Hip Outcome Score—Sport-specific Subscale. Significant outcomes bolded within table.

Four studies included in this analysis demonstrated a significant difference in HOS when comparing compensated and non-compensated patients. Lee et al [22] found that HOS-ADL was significantly different in the 2 groups, both before (46.5 vs 69.2, P < .0001) and after surgery (76.8 vs 89.9, P < .0001). Similar trends were also observed in HOS-SS, with patients receiving compensation scoring significantly worse both preoperatively (25.4 vs 43.6, P = .025) and postoperatively (64.7 vs 79.2, P = .001). Salvo et al [35] identified a similar pattern at 6-month follow-up: WC patients scored significantly lower on HOS after surgery when compared with their counterparts (66.5 vs 89.4, P = .003). Stake et al [39] also confirmed these findings at 2-year follow-up. Although both cohorts improved significantly in HOS-ADL after hip arthroscopy (+29.8 in WC patients, P < .001; +11.1 in non-WC patients, P < .001) and thereby achieved MCID, WC patients still lagged their counterparts postoperatively (69.5 vs 80.9, P < .001) and failed to surpass PASS. Nevertheless, patients on compensation exhibited a greater magnitude of improvement (P = .0429), which the authors used to justify the beneficial role of hip arthroscopy in the WC cohort. Interestingly, although HOS-SS improved significantly in both groups after surgery (+34.5 in WC patients, P < .001; +31.9 in non-WC patients, P < .001), the magnitude of improvement was not significant between both groups (P = .642), unlike with HOS-ADL. However, the postoperative difference in HOS-SS between the 2 cohorts (49.8 in WC patients vs 73.8 in non-WC patients, P < .001) was found to be significant, like with HOS-ADL.

In contradiction to the previous studies, Perets et al [33] showed that patients receiving compensation performed significantly better than their counterparts after hip arthroscopy in terms of HOS-SS. Although WC patients tended to perform significantly more poorly before surgery (18.1 vs 51.2, P < .001), both groups exhibited no significant differences after surgery (66.5 in WC patients vs 69.7 in non-WC patients, P = .71). In addition, the magnitude of improvement was significantly higher in the WC cohort (+48.3 vs +18.4, P = .002), far surpassing the MCID and suggesting that hip arthroscopy offered greater benefit in this cohort.

Conversely, one study found no significant difference in HOS after hip arthroscopy between compensated and non-compensated patients. In their analysis, Gigi et al [14] showed that although the magnitude of improvement in HOS was significant for both respective groups (+10.1 in WC patients, P = .001; +10.7 in non-WC patients, P = .007), the extent of improvement was not significantly different between patients receiving compensation and those not. Moreover, no significant differences in HOS between the 2 groups were observed postoperatively (69.4 vs 77.9, P = .24). All 5 studies reporting HOS as a patient-reported outcome measure demonstrated significant inter-study heterogeneity, which may be appreciated by Fig. 3 (I² = 96.0%, P < .001 and I² = 94.0%, P < .001, for WC and non-WC cohorts, respectively).

Fig. 3.

Forest plot demonstrating overall postoperative HOS by workers’ compensation status. HOS Hip Outcome Score, CI confidence interval, WC workers’ compensation.

Two studies assessed the Non-Arthritic Hip Score (NAHS) both before and after surgery, with mixed evidence (Table 4). Stake et al [39] demonstrated that although the NAHS in both groups was significantly different at baseline (39.3 in WC patients vs 62.6 in non-WC patients, P < .001), the difference in clinical outcomes persisted at 2-year follow-up (66 in WC patients vs 84.4 in non-WC patients, P < .001). The authors additionally showed that both groups improved significantly (+26.7 in WC patients, P < .001; +21.8 in non-WC patients, P < .001), yet the magnitude of improvement was not significantly different between the 2 groups (P = .41). On the other hand, at 5-year follow-up, Perets et al [33] reported that patients on compensation in fact exhibited a significantly higher extent of improvement after hip arthroscopy (+39.2 vs +17.0 in non-WC patients, P < .001). Like Stake et al [39], these authors also found that the preoperative NAHS was significantly lower in WC patients compared with their matched counterparts (39.0 vs 65.0, P < .001). However, unlike Stake et al [39], these authors showed that, over a longer follow-up period, there was no significant difference in NAHS between the 2 cohorts (78.2 in WC patients vs 82.0 in non-WC patients, P = .376).

Table 4.

Mean Non-Arthritic Hip Score (NAHS) in workers’ compensation and non-workers’ compensation cohorts.

Study	Measurement	Workers’ compensation	Non-workers’ compensation	Significance
Perets et al [33]	Preoperative	39.0	65.0	P < .001
	Postoperative	78.2	82.0	P = .376
	Improvement	+39.2 (P < .001)	+17.0 (P < .001)	P = .001
Stake et al [39]	Preoperative	39.3	62.6	P < .001
	Postoperative	66.0	84.4	P < .001
	Improvement	+26.7 (P < .001)	+21.8 (P < .001)	P = .41

Significant outcomes bolded within table.

Two studies assessed preoperative and postoperative levels of pain on the Visual Analog Scale (VAS) in patients undergoing hip arthroscopy. Both studies demonstrated that there was no significant difference in reported pain outcomes after surgery between patients on compensation and those not. Perets et al [33] showed that although WC patients reported a significantly higher level of pain before surgery (6.8 vs 5.2 in non-WC patients, P = .004), both cohorts reported no significant difference in pain at 5-year follow-up (2.9 in WC patients vs 2.4 in non-WC patients, P = .299). The magnitude of pain improvement was comparable in both groups. Stake et al [39] confirmed these findings. Before hip arthroscopy, WC patients tended to report significantly higher levels of pain than their matched counterparts (7.0 vs 5.8, P < .001); however, at 2-year follow-up pain outcomes were comparable in both cohorts (3.9 vs 3.2, P = .57). The magnitude of pain improvement did not differ between the 2 groups.

Three studies documented patient satisfaction rates after hip arthroscopy. Two studies reported no significant difference in satisfaction levels between WC patients and their counterparts. At 2-year follow-up, Stake et al [39] measured satisfaction on a scale from 0 to 10, with 10 being the highest level of satisfaction. Mean patient satisfaction scores were 6.8 in WC patients and 7.7 in their matched pairs, with no significant difference between groups. Likewise, Perets et al [33] reported that mean patient satisfaction scores were not significantly different at 5-year follow-up (7.7 in WC patients vs 7.6 in non-WC patients, P = .952). Only Potter et al [33] demonstrated a significant difference in patient satisfaction rates between the 2 groups. The authors reported that of all patients undergoing hip arthroscopy, overall satisfaction rate was 70%. However, when stratified based on compensation status, patient satisfaction rate was 50% in patients with disability status compared with 84% in patients not on disability (P < .04).

Seven studies examined the incidence of complications following hip arthroscopy. Three studies directly compared the occurrence of complications between patients receiving and not receiving WC. Overall, the number of complications reported was low in both cohorts: across all studies, mean complication rate was 6.4% (range: 1.8%-10.7%) [7,10,13,18,33,35,39]. All studies agreed there was no significant difference in rate of complications between the 2 groups.

The most common complication was minor transient nerve palsy, likely related to traction on the operative extremity and portal placement [18]. The most injured nerve was the pudendal nerve. At 2-year follow-up, Cvetanovich et al [10] reported 9 cases (2.2%) of pudendal nerve paresthesia that resolved 6 to 8 weeks postoperatively. Stake et al [39] reported 2 cases of temporary pudendal neurapraxia in WC patients that resolved without further intervention; no complications were reported in non-WC patients. In addition, Farjo et al [13] reported 1 case (3.6%) of pudendal nerve palsy that completely resolved without any residual functional deficits at 3-year follow-up. The authors also documented 2 cases (7.2%) of sciatic nerve injuries that were not permanent. Finally, Byrd and Jones [7] reported partial neurapraxia of the lateral femoral cutaneous nerve in 1 patient.

Several other complications were also reported but in far lesser frequency. Postoperative deep vein thrombosis (DVT) occurred as a complication in 2 studies. Salvo et al [35] reported 1 patient on compensation who was diagnosed with DVT 1 week after surgery and subsequently treated with oral anticoagulation; the study reported no complications in non-WC cohort. Cvetanovich et al [10] also reported 1 case (0.2%) of DVT, which was appropriately managed. The authors additionally documented 4 cases (1.0%) of superficial infections but these complications resolved with oral antibiotics and did not require return to the operating room. Finally, Stake et al [39] reported 1 case (2.5%) of heterotopic ossification in a patient not receiving compensation, requiring removal via revision surgery. Overall, the difference in the incidence of complications between compensated and non-compensated patients was insignificant. In the longest follow-up study reporting complication incidence, Perets et al [33] found an equal number of total complications (n = 4) both in WC patients and in their matched controls within a 5-year follow-up period (P > .999), suggesting that WC status does not significantly impact complication rate after hip arthroscopy.

There was inconsistency across studies regarding the classification of failure rates; some studies categorized any case requiring secondary hip arthroscopy or THA as a failure, whereas other studies used that designation exclusively for cases requiring revision arthroscopy. In total, 6 studies reported on rates of both arthroscopy revision and conversion to THA because of failure of the index procedure. Overall, the differences in both revision and conversion rates were not significantly different.

The studies included in this review reported a mean revision rate of 7.5% (range: 1.2%-13.1%). The most common indications for revision surgery were failure of the index procedure in the form of persistent pain, capsular adhesions, and tears of the ligamentum teres [12]. Over a 5-year follow-up period, Perets et al [33] reported a 16.7% rate of revision surgery in their WC cohort and a 9.5% rate of revision surgery in their non-compensation-matched control cohort. The difference between these 2 groups was insignificant (P = .516). The authors reported that the mean time to secondary arthroscopy was 24.4 months in WC patients and 31.3 in non-WC patients; both groups exhibited comparable times to revision surgery (P = .786). Stake et al [39] reinforced these findings: 2 patients (10%) receiving WC underwent secondary arthroscopy, whereas 1 patient (5%) not receiving WC underwent secondary arthroscopy. Again, the difference between the 2 groups was not shown to be significant.

Across the studies included in this review, the mean rate of conversion to THA was 10.2% (range: 1.2%-28%). Studies from Byrd and Jones [6,7] were conducted over a decade ago as the learning curve for hip arthroplasty was still being established, hence they reported significantly higher rates of conversion (20%-28%). However, as case load and surgeon experience grew over the years, more recent studies, such as Nho et al [30] have reported significantly lower rates of conversion (1.2%). Perets et al [33] reported a 9.5% rate of conversion to THA in WC patients, compared with a 21.4% rate of conversion to THA in non-compensation-matched counterparts. Although WC patients exhibited a lower rate of conversion, the difference between the 2 groups was insignificant (P = .227). The authors also demonstrated that mean time to conversion was also comparable in both groups (25.2 months in WC patients vs 42.5 months in non-WC patients, P = .68).

Discussion

The feasibility of hip arthroscopy in WC patients has sparked interest in recent literature. Several studies examining various other orthopedic procedures have shown that WC patients with active claims generally experience poorer results after treatment; thus, understanding the influence of WC status on hip arthroscopy outcomes has become increasingly important. The key finding in this systematic review was that WC patients exhibited significant improvements after hip arthroscopy in several standardized hip outcome scores, pain, and satisfaction levels, corroborating that WC status is not a contraindication to this procedure. Although significant baseline functional differences existed between the groups––likely since WC patients tended to be older with more comorbidities––most studies established that patient-reported outcomes after surgery were comparable with those in patients not receiving compensation in most cases, and nearly, all studies demonstrated achievement of MCID, thereby justifying the therapeutic role of hip arthroscopy in the WC cohort. Some studies reported poorer absolute postoperative scores in WC patients and failure to achieve PASS, but these differences rarely reached statistical significance and scores remained clinically reasonable. Furthermore, complication and failure rates proved to be comparable despite WC status. Consequently, this emphasizes that patient selection is key and preoperative counseling is necessary to guide suitable treatment expectations. Most of the included studies demonstrated a significantly greater improvement in WC patients and a greater likelihood to achieve MCID, which ultimately may be the more meaningful measure of hip arthroscopy success in this patient population.

Our findings suggest that functional outcomes, although mostly comparable in both cohorts, may not be the only determinant of hip arthroscopy effectiveness in WC patients. Rather, consideration of complications leading to revision hip arthroscopies and conversions to THA may offer a stronger understanding of the effect of compensation status, as these adverse events are typically associated with greater economic burden and patient dissatisfaction [21]. Overall, reported complication and surgical failure rates were low in patients with active claims, comparable with the results reported in their counterparts, according to all the studies included. In fact, the presence of osteoarthritic changes and obesity were the best indicators of future revision or conversion, as opposed to compensation status [22,36]. Specifically, Perets et al [33], with a 5-year follow-up that was the longest among the included comparative studies, demonstrated no significant differences in the rates of complications, revision arthroscopies, or conversions to THA between patients with and without active claims. These studies suggest that clinical failure rate was not tied to compensation status. Future studies with even longer follow-up periods would be useful to fortify these conclusions further adequately since secondary surgery may not occur until years after the index procedures [3].

This study displays numerous strengths, starting with a methodological search strategy designed to capture all relevant literature. In addition, multiple databases were consulted to ensure as many articles as relevantly possible were considered. Broad inclusion criteria allowed many studies to be analyzed with careful consideration of reviewer bias. Ultimately, while the studies available in the literature were limited to either level III or level IV evidence, we included studies implementing both prospective and retrospective study designs and reporting a wide range of outcome measures. A variety of follow-up periods enabled the authors to identify short-term, mid-term, and long-term results of hip arthroscopy in patients with active claims. Finally, the number of patients included in this review is quite substantial.

This review has some limitations, primarily related to the available literature. Our analysis may be affected by selection bias, as the heterogeneity of patient populations, non-standardized collection of outcome measures in the study pool, and variation in follow-up duration created significant disparities between included studies. Ultimately, this made performing a meta-analysis difficult. Our study may also be weakened by biases in measurement of exposures and outcomes [37]. Although most studies included universal patient-reported outcome measures, there was a lack of standardization across studies as certain scoring tools were utilized by some authors but not others, reducing the quality of inter-study comparisons. In addition, since the scoring instruments used in this study were originally designed to evaluate outcomes for THA, it is unclear if they are appropriately validated to assess outcomes after hip arthroscopy. While all studies reported postoperative outcomes, only a handful documented preoperative baseline data. Furthermore, data pertaining to complications and revisions varied across the literature and reported infrequently, often with differing follow-up periods. Many studies failed to separate outcomes based on the indication for hip arthroscopy. As the popularity of hip arthroscopy has exploded dramatically over the past decade, most of the included studies report short- to mid-term follow-up. Therefore, it is likely that the lifetime risk of complications and secondary surgeries is underestimated in this review and may be subject to unknown baseline confounding variables. Further investigations with longer follow-up would extend outcomes assessment and elucidate the lifetime risk of surgical failure, thereby empowering patients and their providers to decide when surgery is beneficial.

In conclusion, the recent expansion of hip arthroscopic repair has motivated the study of its impact in certain at-risk patient populations. This systematic review found that hip arthroscopy offers clinically significant benefits, regardless of WC status. Although WC patients tended to present with inferior functional scores, improvements after surgery achieved clinical significance and degree of improvement was at least comparable with if not significantly greater than that in the non-WC cohort. Surgery in WC patients offered significant improvements in pain and satisfaction levels. Likewise, complication risk and secondary interventions did not differ between the groups. Further studies should consider more randomized controlled trials with larger cohorts and extended follow-up. Additional factors that may impact surgical outcomes, such as injury severity and disability duration, should also be studied.