What Is the Association Between Articular Cartilage Damage and Subsequent THA 20 Years After Hip Arthroscopy for Labral Tears?

Abstract

Background

Few studies have examined long-term outcomes for patients after arthroscopic treatment for intraarticular hip conditions, and none have done so beyond 10 years postarthroscopy. Examining outcomes beyond 10 years is necessary to determine factors that contribute to conversion to THA in patients undergoing hip arthroscopy for labrochondral damage.

Questions/purposes

(1) What is hip survivorship free from THA in patients who underwent arthroscopic labral débridement, with or without chondroplasty at least 15 years before? (2) What factors are associated with conversion to THA after arthroscopic labral débridement, with or without chondroplasty? (3) Can these data be used to estimate the risk of conversion to THA based on patient- and hip-related factors?

Methods

Between 1989 and 2000, one surgeon performed 552 arthroscopic hip procedures for symptomatic labral tears, with or without associated articular cartilage damage. Of these, the hip status was known in 404 hips (73%) at a minimum of 15 years after the index procedure, with 20 of those patients having died during the followup period. During the study period, patients were offered hip arthroscopy for labral tears with mechanical symptoms, with or without underlying articular cartilage damage. Patient age, sex, acetabular and femoral head Outerbridge grade at surgery, and presence of labral tear were recorded. We determined survivorship free from THA using a Kaplan-Meier survivorship estimator. A stepwise multivariable logistic regression analysis was conducted to determine factors associated with the eventual conversion to THA after hip arthroscopy for labrochondral injuries. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated for all significant independent factors. Odds ratios for combinations of significant factors were used to create a risk assessment.

Results

The survivorship free from conversion to THA at 20 years was 59% (95% CI, 53–64. Factors that affected survival included age ≥ 40 years and the presence of combined femoral head and acetabular chondral damage. After controlling for confounding factors, we found that age ≥ 40 years (OR, 2.0; 95% CI, 1.2–3.4; p = 0.011), the absence of all chondral damage (OR, 0.1; 95% CI, 0.03–0.32; p < 0.001), the presence of acetabular damage with severe femoral head damage (OR, 5.0; 95% CI, 2.4–10.3; p < 0.001), and the presence of severe acetabular damage with femoral head damage (OR, 3.7; 95% CI, 2.0–6.8; p < 0.001) were associated with conversion to THA at long-term followup. Based on the calculated ORs, the probability of conversion to THA by 20 years postarthroscopic treatment for labrochondral injuries ranged from 12% (95% CI, 8–17) for a patient younger than 40 years with a Grade 0-II femoral and acetabular Outerbridge grade to 92% (95% CI, 86–95) for a patient older than 40 years with a Grade III-IV femoral and acetabular Outerbridge grade.

Conclusions

Our study revealed that survivorship free from THA at 20 years after arthroscopic labral débridement was associated with both patient age at time of index procedure and, more importantly, the presence of combined femoral head and acetabular chondral damage. Patients should be counseled as to the increased probability of conversion to THA, depending on the health of their articular cartilage after surgery. Future studies should examine survivorship free from THA or clinical symptoms in patients undergoing hip arthroscopy with bone reshaping procedures or with labral repair or reconstruction up to and exceeding 20 years.

Level of Evidence

Level III, therapeutic study.

Introduction

Arthroscopic treatment of both intra- and extraarticular hip conditions continues to expand through advancements in both our understanding of the pathogenesis of these conditions and emerging surgical techniques. As the complexity of arthroscopic procedures for the treatment of labrochondral injuries continues to increase, assessing the long-term success of these procedures is of utmost importance to determine the appropriate treatment plans for patients. Identifying which patients will benefit from surgical treatment of labral tears with or without underlying chondral surface damage continues to be a challenge, and the knowledge provided by studies that examine long-term outcomes can serve as the foundation on which future advancements are made. Given that many recent advances in hip preservation focus on techniques to extend the life of the native joint, identifying factors associated with long-term survivorship of arthroscopic treatment of labral tears is essential for identifying the most effective treatments.

Few studies have examined long-term outcomes for patients after arthroscopic treatment for intraarticular hip conditions, and none have done so beyond 10 years postarthroscopy. Clinical improvements in pain and function have been reported for patients up to 10 years postarthroscopic treatment of labrochondral injuries, with or without bone reshaping [1, 3, 4, 6, 8-10]; however, as many as 44% of patients underwent revision procedures at 10-year followup [1, 4, 6, 10]. Higher rates of conversion to THA were reported for patients who were older than 40 years at time of surgery [6, 10] and who had radiographic presence of arthritis before surgery [3, 4, 6, 10]. Overall 10-year survivorship rates ranged from 63% to 75% [6, 10], with one study reporting lower survival rates for patients who did not undergo labral reattachment during surgical correction of femoroacetabular impingement (FAI) compared with those who did [1]. The presence of grade III or IV articular cartilage lesions was also shown to increase a patient’s odds of undergoing a THA within 10 years by up to 58 times compared with patients with mild grades of chondral damage [10]. Although the knowledge gained from these previous studies provided pivotal information regarding factors that contribute to conversion to THA in patients undergoing hip arthroscopic procedures for the treatment of labrochondral damage, with or without bone reshaping, examining outcomes beyond 10 years is necessary, given that many patients are younger than 30 years of age at time of surgery.

Therefore, we asked: (1) What is hip survivorship free from THA in patients who underwent arthroscopic labral débridement, with or without chondroplasty at least 15 years before? (2) What factors are associated with conversion to THA after arthroscopic labral débridement, with or without chondroplasty? (3) Can these data be used to estimate the risk of conversion to THA based on patient- and hip-related factors?

Patients and Methods

Using our institutionally approved longitudinally-maintained database, we retrospectively identified 534 patients (552 hips) who underwent arthroscopic evaluation of their hip to treat a symptomatic labral tear, with or without associated articular cartilage damage, between 1989 and 2000. In the entire cohort, there were 318 women (60%) and 216 men (40%) with a mean age of 37 ± 12 years at the time of surgery. Hip status was ascertained for 392 patients (404 hips) at a mean of 19 ± 3 years (range, 16–27 years). Of those, 20 patients (5%) had died. An additional four patients (1%) had not been seen clinically within 5 years, but they did have followup greater than 15 years and were included in the analysis. Hip status was unknown in 142 patients (148 hips) (27%), and we considered these patients lost to followup (Fig. 1). The final study cohort consisted of 221 women (59%) and 151 men (41%) with a mean age of 38 ± 12 years at the time of arthroscopy. The study cohort was older than the cohort lost to followup (38 ± 12 versus 33 ± 10; p < 0.001), but not different in sex distribution (59% versus 59%; p = 1.000, Θ = 0.001). The two cohorts also did not differ in the prevalence of patients without chondral damage for the anterior (52% vs. 60%; p = 0.122, Cramer’s V = 0.089) or posterior (80% versus 88%; p = 0.086, Cramer’s V = 0.096) femoral head or the superior acetabulum (69% versus 77%; p = 0.200, Cramer’s V = 0.078). However, the followup cohort exhibited a higher prevalence of severe damage on the superior femoral head (15% versus 8%; p = 0.013, Cramer’s V = 0.128) and anterior acetabulum (42% v versus s. 27%; p = 0.005, Cramer’s V = 0.142), along with a higher prevalence of mild damage on the posterior acetabulum (23% versus 13%; p = 0.030, Cramer’s V = 0.15) compared with patients lost to followup.

Fig 1.

Shown here is the flow diagram that documents the study participants.

Indications for arthroscopic partial labral débridement, with or without chondroplasty, included intractable anterior or inguinal pain with mechanical symptoms, along with confirmation of intraarticular pathology via MRI or contrast MRI. Additional indications included age older than 18 years and the presence of residual pain and functional limitations, which did not respond to at least 3 months of activity modification, nonsteroidal antiinflammatories or physical therapy. These indications did not change during the study period. Patients were not candidates for arthroscopic treatment of labral tears, with or without chondral damage, if they had a BMI greater than 30, had a joint space width less than 2 mm on plain radiographs, or had other confirmed sources of hip pain, including previously unidentified fracture, tumor, severe dysplasia (center-edge angle < 20°), and/or avascular necrosis.

All patients underwent arthroscopic labral débridement, with or without chondroplasty, in the lateral decubitus position with a dedicated hip distractor set at 7 to 10 mm of distraction [11]. Arthroscopic intervention for labrochondral injuries was performed in the central compartment only, as the study time points occurred before the recognition of peripheral compartment morphological abnormalities. All arthroscopic labral débridements were performed as outpatient procedures. Labral tears were treated with débridement of the damaged tissue using a low-frequency thermal tool or curved shaver, and minimal resection of white zone lesions was performed, leaving the capsular attachment. Full-thickness chondral lesions were treated with microfracture and partial-thickness lesions were minimally resected to a stable base. At the time of surgery, the senior author (JCM) identified and graded for severity the morphologic features and location of all labral and articular cartilage lesions. Findings from each surgical procedure were recorded and entered into the database. Labral abnormalities were described by location (posterior, lateral, anterior). The number of regions that exhibited labral damage was calculated and classified as single (0-1 regions) or multiple (2-3 regions).

The severity of the femoral and acetabular articular cartilage lesions were graded for each region (anterior, superior, posterior) of both the femoral head and acetabulum according to the Outerbridge classification system [6], where Grade I refers to softening and/or swelling of the cartilage; Grade II refers to fragmentation and fissuring extending less than 10 mm in diameter; Grade III consists of fragmentation and fissuring extending greater than 10 mm in diameter; and Grade IV refers to full-thickness cartilage erosion with exposed subchondral bone. The degree of damage was classified as absent, mild (Grades I/ II), or severe (Grades III/ IV) for analysis purposes.

Initial contact was attempted for all patients using their last known phone number and mailing address. For those patients whose information was outdated, we then attempted to locate them using their electronic medical record, detailed online search methods, public death records, or contact through any known family members. For the study cohort, followup data were obtained through recent office visits (n = 177), phone calls from a research assistant (CMT or AB) (n = 104), and mailed surveys that were completed and returned (n = 103). Information collected from patients included whether they had undergone a subsequent THA on their surgical hip, and, if so, the date of the THA. If the patient had not undergone a THA, the date of contact was used as the followup date. At followup, 153 patients (158 hips) reported having undergone a THA on their surgical hip (41%). The mean time to THA for this group was 7 ± 5 years (range, 0–21 years), with 29% of hips lasting at least 10 years before undergoing reconstruction. At the time of THA, 50% of patients were older than 50 years of age. For the 219 patients (226 hips) who did not undergo THA, the mean time to followup was 19 ± 3 years (range, 16-27 years), and 65% of patients were older than 50 years of age at time of contact. The nonTHA patients were younger than the THA patients at time of arthroscopic labral débridement (34 ± 11 versus 44 ± 11; p < 0.001), but did not differ in sex distribution (65% versus 54%; p = 0.121, Θ = 0.105). The nonTHA group also had fewer patients who were 40 years or older at the time of arthroscopic labral débridement (30% versus 63%; p < 0.001, Θ = 0.334) and who presented with labral damage in multiple regions (21% versus 54%; p < 0.001, Θ = 0.342) compared with the THA group.

We summarized continuous variables with a mean and SD and compared the two groups (THA, no THA) using independent samples t-tests. To better delineate the role of chondral damage on the likelihood of conversion to THA, we created binary variables that assessed different combinations of location and degree of chondral damage (femoral head, acetabulum). The combinations included the presence of any degree of acetabular damage with any degree of femoral head damage; the presence of any degree of acetabular damage with mild femoral head damage; the presence of any degree of acetabular damage with severe femoral head damage; the presence of severe acetabular damage with any degree of femoral head damage; the presence of severe acetabular damage with mild femoral head damage; and the presence of severe acetabular damage with severe femoral head damage. The absence of all chondral damage was also considered for the analysis. In addition, we grouped patients based on age at arthroscopy, and we chose a cutoff of 40 years to define the groups. The age variable was dichotomized because discrete groups are needed to calculate odds ratios of increased risk and a table of risk factors for eventual THA. We selected 40 years of age as the cutoff based on the results of a ROC analysis and the proximity to the population median age. To determine the presence of correlations between patient and surgical factors and eventual conversion to THA, we conducted separate univariate crosstabulations with THA or no THA as the binary outcome for age at arthroscopy (< 40 years, ≥ 40 years), sex, each individual chondral binary variable, and regions with labral damage. All factors found to be significant in the univariate model, determined by a threshold of p < 0.05, were incorporated into our multivariate model. Collinearity diagnostics were run on the full model, and factors which were found to exhibit multicollinearity, as defined as a variance inflation factor > 3, were removed. We then conducted a stepwise multivariable logistic regression analysis to determine factors associated with the eventual conversion to THA after hip arthroscopy for treatment of labrochondral injuries, using the dichotomized variables of age at arthroscopy, absence of all chondral damage, presence of any degree of acetabular damage with only severe femoral head damage, and the presence of severe acetabular damage with any degree of femoral head damage. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for all significant independent factors. Using the ORs for combinations of significant predictors, we generated a table to be used for risk assessment of the probability of conversion to THA. A Kaplan-Meier survivorship curve was created to determine survivorship free from conversion to THA. The influence of all significant independent factors and their interactions on survivorship was then assessed using the log-rank test. All statistical analyses were performed using IBM SPSS v.21.0 (IBM Corp, Armonk, NY, USA). The level of statistical significance was set at p < 0.05.

Results

The Kaplan-Meier estimated survivorship free from THA at 20 years was 59% (95% CI, 53–64), with 80% (95% CI, 76–84) survival at 5 years, 70% (95% CI, 65–74) at 10 years, and 63% (95% CI, 58–68) at 15 years (Fig. 2). Kaplan-Meier estimated survivorship was associated with patient age and chondral damage severity and location (Table 1). When stratified by age at arthroscopic labral débridement, mean survivorship was reduced for patients 40 years or older compared with patients who were younger than 40 years (22 years; 95% CI, 21–23 years versus 14 years, 95% CI, 13–16 years; p < 0.001). Mean survivorship was also reduced for patients with any degree of acetabular damage and severe femoral head damage compared with patients without this combination of damage (8 years, 95% CI, 6–10 years versus 22 years; 95% CI, 21–23 years; p < 0.001) and patients with severe acetabular damage plus any degree of femoral head damage compared with patients without this combination of damage (9 years; 95% CI, 8–11 years versus 23 years; 95% CI, 22–24 years; p < 0.001). The influence of age on survivorship was examined further by stratifying age groups by the presence of combined acetabular and femoral head damage. When examining the interaction between age and the presence of any degree of acetabular damage with severe head damage (Fig. 3), mean survivorship was not different for patients aged 40 years and older compared with patients younger than 40 when that combination of damage was present (6 years; 95% CI: 5–8 versus 11 years; 95% CI, 7–14 years) or when that combination of damage was absent (19 years; 95% CI, 17–21 years versus 24 years; 95% CI, 23–25 years; Table 2). Similarly, when examining the interaction of age and the presence of severe acetabular damage plus any degree of femoral head damage (Fig. 4), mean survivorship did not differ between patients older than 40 years compared with patients younger than 40 years in the absence of this combination of damage (7 years; 95% CI, 5–9 years versus 13 years; 95% CI, 9–16 years) or when that combination of damage was present (20 years; 95% CI, 18–22 years versus 24 years; 95% CI, 23–25 years; Table 3).

Fig. 2.

The Kaplan-Meier estimated survivorship for the study cohort (n = 283) using THA as an endpoint was 80% at year 5, 70% at year 10, 63% at year 15, and 59% at year 20.

Table 1.

The Kaplan-Meier estimated survivorship based on age and the presence of combinations of chondral damage

Fig. 3.

The Kaplan-Meier estimated survivorship based on age at arthroscopy and stratified for the absence and presence of any degree of acetabular damage with severe femoral head damage is presented; < 40 years, no damage = patients who were younger than 40 years at time of arthroscopy and had no chondral at surgery; < 40 years, damage = patients who were younger than 40 years at time of arthroscopy and had the combination of any degree of acetabular damage with severe femoral head damage; > 40 years, no damage = patients who were older than 40 years at time of arthroscopy and had no chondral at surgery; < 40 years, damage = patients who were older than 40 years at time of arthroscopy and had the combination of any degree of acetabular damage with severe femoral head damage.

Table 2.

The Kaplan-Meier estimated survivorship based on age and stratified by the presence or absence of any degree of acetabular damage with severe femoral head damage

Fig. 4.

The Kaplan-Meier estimated survivorship based on age at arthroscopy and stratified for the absence and presence of severe acetabular damage with any degree of femoral head damage is presented; < 40 years, no damage = patients who were younger than 40 years at time of arthroscopy and had no chondral at surgery; < 40 years, damage = patients who were younger than 40 years at time of arthroscopy and had the combination of any degree of acetabular damage with severe femoral head damage; > 40 years, no damage = patients who were older than 40 years at time of arthroscopy and had no chondral at surgery; < 40 years, damage = patients who were older than 40 years at time of arthroscopy and had the combination of any degree of acetabular damage with severe femoral head damage.

Table 3.

The Kaplan-Meier estimated survivorship based on age and stratified by the presence or absence of severe acetabular damage with any degree of femoral head damage

After controlling for confounding variables, we found that age older than 40 years (OR, 2.0; 95% CI, 1.2–3.4; p = 0.011), absence of all chondral damage (OR, 0.10; 95% CI, 0.03–0.32; p < 0.001), any degree of acetabular damage with severe femoral head damage (OR, 5.0; 95% CI, 2.4–10.3; p < 0.001), and severe acetabular damage with any degree of femoral head damage (OR, 3.7; 95% CI, 2.0–6.8; p < 0.001) were associated with conversion to THA at long-term followup (Table 4). Patients who were 40 years or older at time of arthroscopic labral débridement were 2.0 times more likely to convert to THA. Patients with any degree of acetabular damage plus severe head damage were 5.0 times more likely, while patients with severe acetabular damage plus any degree of head damage were 3.7 times more likely to convert to THA. Conversely, patients without any chondral damage at the time of arthroscopic labral débridement were 90% less likely to undergo a THA.

Table 4.

Multivariable logistic regression analysis with odds of undergoing a THA

A probability risk assessment based on ORs from the regression model revealed that a patient who was younger than 40 years of age at time of arthroscopic treatment of labral injuries with no chondral damage had only a 2% (95% CI, 1–7) probability of undergoing conversion to THA within 20 years, and there was only a 7% (95% CI, 2–21) probability for patients who were older than 40 years without damage. For patients younger than 40 years of age at arthroscopy for the treatment of labral injuries with any degree of chondral damage, there was a 38% (95% CI, 3–46) probability of undergoing THA within 20 years, while those patients older than 40 years of age with any degree of chondral damage had a 66% (95% CI, 58–73) probability of conversion to THA. The probability of undergoing THA based on different combinations of age and damage ranged from 12% for a patient younger than 40 years at the time of arthroscopy with no severe damage in either the acetabulum or femoral head to 92% for a patient older than 40 years at the time of arthroscopy with the presence of severe damage in both the acetabulum and femoral head (Table 5).

Table 5.

Probability of THA based on combinations of predictors from multivariate analysis

Discussion

As we continue to advance our understanding of and treatment strategies for acetabular labrochondral injuries, identifying factors associated with long-term survivorship after arthroscopic treatment of these injuries is essential to identify the most effective interventions. Few studies have reported long-term outcomes after hip arthroscopy for labrochondral damage, and, to date, none have done so beyond 10 years after surgery. For our cohort of patients at 20 years after arthroscopic labral débridement, with or without chondroplasty, survivorship free from THA was 59% (95% CI, 53–64), with less than half of our patients undergoing THA during the followup period. Factors that contributed to conversion to THA included older age and the presence of combined acetabular and femoral head damage, with one region classified as severe. All factors were associated with overall survivorship; however, when stratified by age, the presence of combined chondral damage mitigated the influence of age; survival curves did not differ between the two age groups depending on the absence or presence of joint damage.

Our study is not without limitations. First, ours was a retrospective case series without a control group. Without a control group, we are unable to make any determinations about whether the outcomes of our long-term survival analysis would differ from patients who did not undergo surgical intervention for labrochondral injuries. We were also unable to obtain pre- and postsurgical patient-reported outcome measures for our cohort, so we cannot state whether the arthroscopic labral débridement our patients underwent improved symptoms or provided any greater benefit compared with not undergoing surgery. As such, the results of our study should not be used to determine whether surgical intervention is the most appropriate treatment strategy for patients with symptomatic labrochondral lesions, but they could provide a general guideline for patients who choose to undergo surgery. Second, we had trouble locating a substantial proportion of our patients, given that many relocated or changed contact information in the 15 to 20 years since surgery. We recognize that our attrition rate of 30% could affect our results and introduce transfer bias. Thus, the survivorship from THA that we report could underestimate conversion to THA rates for this population of patients. However, we compared surgical and clinical data between our study cohort and those patients who were lost to followup, and we observed that the patients lost to followup were younger and had reduced rates of severe chondral damage at the time of surgery compared with our study cohort. Therefore, the patients lost to followup may not be at a greater risk for THA compared with the study patients, but we caution that our results should only be considered as a “best-case” scenario without further evidence. Third, our results may be affected by selection bias. The study spans a large period, during which arthroscopic treatment of intraarticular hip conditions was evolving. The participating surgeon’s (JCM) indications for recommending arthroscopic intervention to patients with symptomatic labrochondral injuries did not change during the study period; however, we cannot state with certainty that surgical intervention was performed for all patients who were eligible during the timeframe. In addition, given the advancements in understanding the patient factors that contribute to surgical outcomes and in imaging techniques that have enhanced our ability to detect articular cartilage damage which have occurred since 2000, our study cohort may have included patients who would not be identified as surgical candidates by today’s standards. However, this is most likely applicable to the patients for whom more severe chondral damage was observed during surgery; the removal of these patients would have inflated our survival statistics.

Given that all patients included in our study underwent hip arthroscopic labral débridement before digital x-rays and the initial description of femoroacetabular impingement syndrome by Ganz et al. [7], we cannot speculate as to the potential influence of altered bony morphology on outcomes for our patients. Our study also preceded recent advancements in repairing and reconstructing damaged labra. We recognize that this may limit the applicability of our findings to patients undergoing these procedures; however, selective labrum débridement is still considered an appropriate treatment for certain patients [2, 5], and a recent comparative study demonstrated similar midterm outcomes between this procedure and labral repair [5]. Fifth, our selection of THA as our endpoint for survival analysis could introduce assessment bias and influence our results. Without knowledge of whether the surgical intervention improved patients’ symptoms, there is the potential that a subset of patients who chose not to undergo THA still experience hip symptoms and would not be considered a clinical success. In fact, out of the 219 hips who did not undergo THA, 8% stated that they are considering conversion. As such, the results of our study should only be used to counsel patients as to their risk of conversion to THA and not resolution of symptoms after surgery. Sixth, this is a single, high-volume surgeon series at a tertiary care hospital. As such, our results may not apply well to the practices of low-volume surgeons. Finally, we were unable to obtain comprehensive demographic data for our patients, such as body mass index. Without this, the applicability of our results is limited to broad patient categories (age, sex).

For our cohort of patients after arthroscopic labral débridement, with or without chondroplasty, survivorship free from THA at 20 years after surgery was 59%. No previous study has reported survival rates for patients undergoing hip arthroscopic procedures out to 20 years; however, studies have reported 10-year survival rates free from revision arthroscopic procedures or THA ranging from 63% to 75% for patients undergoing treatment for labrochondral injuries, which is in accordance with our 10-year survivorship free from THA of 70%. Overall estimated survivorship was highly associated with age and the presence of combined femoral head and acetabular damage. These results are similar to a previous study which demonstrated that the presence of severe chondral damage greatly reduced 10-year survivorship free from THA for patients undergoing arthroscopic treatment of labral tears and that the probability of THA was increased for patients older than 40 years at the time of surgery [10]. However, our results show that although older age can be associated with conversion to THA in patients undergoing arthroscopic labral débridement, the influence of age on survivorship is mitigated when cartilage status is considered. Overall survivorship free from THA was comparable between age groups (< 40 years, ≥ 40 years) when stratified by the absence or presence of combined femoral head and acetabular damage (Table 2 and Table 3). However, comparing overall survivorship based on cartilage status revealed drastic reductions when patients presented with combined femoral head and acetabular damage, regardless of age. Thus, for most patients undergoing hip arthroscopic labral débridement, the status of the articular cartilage surfaces is better associated with conversion to THA than chronological age.

Factors that were associated with conversion to THA after arthroscopic labral débridement were age, the absence of all chondral damage, the combination of any degree of acetabular chondral damage with severe femoral head damage, and the combination of severe acetabular damage with any degree of femoral head damage. Our results are in accordance with previous studies that identified an association between increasing severity of chondral damage and conversion to THA in patients who underwent hip arthroscopic treatment for labrochondral injuries [6, 10, 12, 13]. Combinations of severe damage on the acetabular and femoral head were highly associated with conversion to THA in our patients, with the presence of this type of damage resulting in an increase in the risk of conversion to THA. Interestingly, the presence of severe damage isolated to either the acetabulum or femoral head was not associated with undergoing THA and was a more prevalent finding in our nonTHA study patients. Overall, isolated acetabular chondral damage was observed more frequently than isolated chondral damage on the femoral head, and isolated acetabular damage most often located in the same region as the observed labral damage. These findings suggest that the presence of severe damage alone is not as important for survivorship from arthroscopic labral débridement as the distribution of damage throughout the articular cartilage surfaces.

Using the data from the factors associated with conversion to THA, we were able to create a risk assessment showing the probability of a patient converting to THA by 20 years after arthroscopic labral débridement. Overall, the probability of undergoing THA at 20 years in patients who have no chondral damage at the time of surgery is less than 10%, regardless of age. For patients who present with any degree of chondral damage on any surface, the risk of undergoing THA at 20 years for patients older than 40 years of age is almost twice that of patients younger than 40 years at time of surgery. Stratifying the risk of conversion to THA based on different combinations and locations of chondral damage revealed that risk is increased as the severity and dispersion of damage increases, regardless of age. Our results are similar to a previous study that reported the probability of conversion to THA at 10 years after arthroscopic labral débridement based on age and chondral damage [10]. The risk of conversion to THA increased as the level of chondral damage progressed in their cohort of patients, as well. These results suggest that patients who undergo arthroscopic intervention for labrochondral injuries before developing widespread chondral damage may have a reduced risk of converting to THA at 20 years. This information could be used as a guide for clinicians to counsel patients undergoing arthroscopic labral débridement regarding their long-term risk of undergoing THA, and it may serve as a benchmark to compare survivorship from hip arthroscopy for other indications in the future.

Our study revealed that less than half of patients undergo conversion to THA up to 20 years after arthroscopic labral débridement. Factors that contributed to conversion to THA included older age and chondral damage present on both the femoral head and acetabulum, with damage on one surface being severe. Importantly, when chondral damage was considered, the influence of age on undergoing THA was mitigated, suggesting that the status of the hip articular cartilage at the time of surgery ultimately decides the fate of the joint, not a patient’s age. The results of our study can be used to counsel patients after arthroscopic labral débridement about realistic expectations regarding the probability of conversion to THA, depending on the health of their articular cartilage. Future studies should examine survivorship free from THA or clinical symptoms in patients undergoing hip arthroscopy with bone reshaping procedures or with labral repair or reconstruction up to and exceeding 20 years.