Kang, Louis

Abstract Purpose Acetabular overcoverage (pincer morphology) has been suggested to be both a source of pain and dysfunction as well as potentially protective against osteoarthritic change. The purpose of this study was to compare minimum 5-year clinical outcomes of patients undergoing primary hip arthroscopic labral repair with a lateral center edge angle (LCEA) of ≥ 40° as compared to non-dysplastic controls with an LCEA of 25-40°. Methods We identified all patients that underwent primary hip arthroscopy with labral repair between 2009-2019 at a single academic institution. Patients with LCEA ≥ 40° (pincer) were propensity matched to non-dysplastic controls with LCEA 25-40° on a 1:2 basis by sex, age, body mass index (BMI), and year of surgery. Patient-reported outcome measures (PROMs) including Visual Analog Scale (VAS) for pain, Tegner activity score, modified Harris Hip Score (mHHS), International Hip Outcome Tool (iHOT-12), and Hip Outcome Score (HOS) were analyzed, as were reoperations and conversions to total hip arthroplasty (THA). Results Fifty-five patients with pincer morphology (mean preoperative LCEA: 41.9°, Tonnis angle: -7.3°, alpha angle: 58.8°) were matched to 110 non-dysplastic controls (LCEA: 31.2°, Tonnis angle: 2.2°, alpha angle: 58.9°), resulting in a total of 165 hips in 163 patients (67% females, mean age: 37.7 years, BMI: 26.8 kg/m2). Pincer patients were corrected to a mean postoperative LCEA of 38.7° (p<0.0001), with 22 pincer patients having residual overcoverage, namely a postoperative LCEA ≥ 40° (range: 40.0-45.8°). At mean 7.8 years follow-up (range: 5.1-13.2), there was no difference in any postoperative PROMs between pincers and controls (p>0.15) and no difference in PROMs between patients with residual overcoverage and pincer patients with a postoperatively normalized LCEA (p>0.25). At final follow-up, 4 patients in the pincer cohort (7%) and 21 controls (19%) had converted to THA (p=0.046). Conclusion Patients with lateral acetabular overcoverage demonstrated similar and satisfactory postoperative PROMs at a minimum of 5-year follow-up compared to propensity-matched non-dysplastic controls, regardless of if the LCEA was corrected to <40°. Of note, non-dysplastic controls demonstrated an increased rate of conversion to THA, supporting the potentially chondroprotective role of acetabular overcoverage.

Abstract Purpose Patients presenting for iliopsoas tendinitis consultation after total hip arthroplasty (THA) often describe a prolonged time to diagnosis and subsequent surgical management. The purpose of this study was to quantify time from symptom onset to diagnosis and subsequent arthroscopic iliopsoas fractional lengthening, including number of providers seen. Methods Patients undergoing arthroscopic iliopsoas fractional lengthening after THA were prospectively identified between 2023-2025 at a single institution. Time from symptom onset to iliopsoas tendinitis diagnosis as well as arthroscopic lengthening were determined. Number of providers seen, diagnostic relief from preoperative iliopsoas bursal injections, and postoperative satisfaction after fractional lengthening were also evaluated to better quantify indications and outcomes of arthroscopic intervention in this population. Results A total of 44 hips in 41 patients (23 females and 18 males) were included (mean age: 64.7 ± 10.2, mean BMI: 29.9 ± 5.9 kg/m2). Of note, 7 patients (16%) had undergone revision THA prior to iliopsoas symptom onset. Patients had on average 2.2 ± 2.1 years of symptoms and saw 2.5 ± 1.7 [range: 1-8] providers prior to being diagnosed with iliopsoas tendinitis and referred for consideration of arthroscopic fractional lengthening. Preoperatively, 93% of patients underwent at least 1 iliopsoas bursal corticosteroid injection, with an average of 81.1% symptom relief during the diagnostic (anesthetic) phase. The mean time between THA and iliopsoas fractional lengthening was 4.8 ± 3.4 years, whereas the mean time between initial iliopsoas tendinitis symptoms to fractional lengthening was 3.1 ± 2.5 years. At a mean of 11.3 ± 6.8 months postoperatively, mean surgery satisfaction was 8.1 ± 2.6 on a scale of 1 to 10, with the vast majority of patients (89.5%) stating that they would undergo fractional lengthening again. Conclusion Patients often experience a protracted period of symptoms and see multiple clinicians prior to being diagnosed with iliopsoas tendinitis and undergoing arthroscopic management. In patients refractory to conservative management, arthroscopic fractional lengthening can provide high surgery satisfaction, with most patients stating they would undergo the procedure again. These findings highlight the importance of increased recognition and appropriate referral of patients with iliopsoas tendinitis following THA.

Abstract Introduction Understanding factors that impact outcomes of total hip arthroplasty (THA) can aid clinical decision-making and patient counselling. The purpose of this study was to investigate functional outcomes, complications, and reoperation rates among patients undergoing primary THA after hip arthroscopy (HA-THA) compared to a matched cohort of primary THA patients without prior arthroscopy (THA-only). Methods A retrospective review was performed to identify all patients who underwent primary THA after prior hip arthroscopy from 2009-2022 at a single institution. Patients with a history of revision arthroscopy were excluded. Cases were propensity-matched with primary THA controls in a 1:4 ratio by age at time of THA, sex, body mass index, surgical approach, and year of surgery. At minimum 2-year follow-up, patient-reported outcomes (PROs) including Forgotten Joint Score (FJS), Modified Harris Hip Score (mHHS), Hip Disability and Osteoarthritis Outcome Score Pain (HOOS pain), and Visual Analog Pain Scale (VAS) were analyzed. Results Sixty-three hips in 60 patients (age: 47.3±9.4 years, BMI: 29.8±6.2 kg/m2) were matched to 252 THA-only hips, with patients converting to THA at a mean 3.1 years (range 0.3-10.3) following hip arthroscopy. While both HA-THA and THA patients demonstrated significant (p<0.001) postoperative improvements in PROs, HA-THA patients reported significantly lower postoperative FJS, mHHS, HOOS pain, and VAS pain scores (p<0.001) as compared to THA-only controls. At mean 6.6±3.2 years follow-up, HA-THA patients with preoperative Tönnis grades 2-3 reported significantly increased FJS, mHHS, and HOOS pain compared to those with preoperative Tönnis grades of 0-1 (p≤0.03). Additionally, HA-THA patients with preoperative Tönnis grades 0-1 exhibited worse PROs (p<0.001) as compared to THA-only controls. While there were no differences in complication rates between HA-THA patients and THA-only controls (8% vs. 5%, p=0.49), all-cause reoperation was greater amongst HA-THA patients compared to THA-only (10% vs. 2%, p=0.01). Conclusion While improved compared to preoperatively, patients undergoing THA after prior hip arthroscopy demonstrated inferior outcomes at mid-term follow up as compared to a demographically age-matched cohort without prior arthroscopy. When considering conversion to THA following arthroscopy, clinicians should consider counseling patients regarding improved outcomes in the setting of advanced radiographic osteoarthritis, and potentially increased all-cause reoperation.

Objective The incidence of hip osteoarthritis (OA) is increasing with the aging population, leading to interest in intra-articular orthobiologic injections to alleviate symptoms and potentially slow disease progression. This systematic review aims to evaluate the clinical outcomes associated with six orthobiologic therapies for hip OA: hyaluronic acid (HA), platelet-rich plasma (PRP), autologous cells therapy (ACT), microfragmented adipose tissue (MFAT), and bone marrow aspirate (BMA) and its concentration (BMAC). Methods We conducted a literature search according to the PRISMA guidelines. Studies were included in our review if they used at least one of the four orthobiologic therapies and reported on the clinical outcome using patient reported outcome measures (PROMs). Since there is a large variability among clinical outcomes, we focused on the three most utilized PROMs (VAS, WOMAC, and HHS) and the latest follow-up time point. Results Of the 716 studies reviewed, thirty-six studies (n=36) fit inclusion criteria. There were 21 studies examining HA, 11 on PRP, 3 for MFAT, 2 for ACT, and 3 on BMA/BMAC. Eight studies were randomized controlled trials and 28 were cohort studies. The mean age of the patient population ranged from 45 ± 17.0 to 74 ± 8.0. The baseline grade of osteoarthritis ranged from 1-4 but was most reported as moderate (2-3). Overall, there was an improvement in PROMs at the latest follow-up after receiving orthobiologic interventions. Discussion Orthobiologic injections have shown promise for improving PROMs in patients with hip OA. Future studies should evaluate long-term efficacy and include randomized trials to establish efficacy.

Background: Injury to the medial ulnar collateral ligament (MUCL) is a common setback for throwing athletes, often requiring reconstruction with 12 to 18 months of rehabilitation. The authors previously described a more anatomic technique with improved mechanical strength as compared with the docking technique, which may allow for an accelerated return to sport. Purpose: To evaluate return-to-sport rates, time to return to sport, and the effect on the functional performance of amateur and professional throwing athletes who underwent anatomic MUCL reconstruction with suture tape augmentation. Study Design: Case series; Level of evidence, 4. Methods: A retrospective case series was performed including baseball players who underwent anatomic MUCL reconstruction with suture tape augmentation by a single surgeon from 2018 to 2022. Inclusion criteria consisted of a minimum 2-year follow-up, participation in baseball, and utilization of autograft (palmaris longus or gracilis). Patients who underwent previous MUCL reconstruction were excluded from the study. All patients initially followed an accelerated rehabilitation protocol. Outcome measures were collected, including Kerlan-Jobe Orthopaedic Clinic (KJOC), Single Assessment Numeric Evaluation (SANE), and Conway-Jobe scores, as well as throwing metrics such as ball velocity and spin rate. Results: Thirty-four baseball players (mean ± SD age, 21 ± 3 years) underwent primary MUCL reconstruction. Time of final follow-up was 36.1 ± 10.3 months. Of these, 16 were professional athletes and 18 were amateur. All throwers returned to live gameplay at a mean 10.1 ± 2.0 months after reconstruction (professional, 10.6 ± 2.3; amateur, 9.7 ± 1.8). Furthermore, 97% (94% professional, 100% amateur) advanced through the accelerated postoperative protocol without issues, and 91% (88% professional, 94% amateur) returned to the same role and 85% (75% professional, 94% amateur) to the same level of play. Professional postinjury KJOC scores improved from 42.6 ± 16 to 87.5 ± 8.3 and SANE scores from 25.0 ± 11.2 to 95.6 ± 4.2. Amateur postinjury KJOC scores improved from 35.6 ± 10.7 to 90.9 ± 8.6 and SANE scores from 57.5 ± 16.9 to 95.2 ± 7.2. No significant difference was identified in preinjury versus postreconstruction throwing velocity, ball spin rate, or horizontal/vertical ball movement. The overall failure rate was 2.9%, with 1 professional pitcher requiring revision for graft rupture at 3 years postoperatively. Conclusion: Anatomic reconstruction of the MUCL with suture tape is a viable option for MUCL injuries, allowing an expedited return to sport at 10.1 ± 2.0 months (professional, 10.6 ± 2.3; amateur, 9.7 ± 1.8) in baseball players, with a low failure rate.

Background: Femoroacetabular impingement (FAI) is a common cause of hip pain in female athletes. There are limited data on midterm outcomes for female athletes undergoing hip arthroscopic surgery. Purpose: To evaluate return-to-sport rates and clinical outcomes in female athletes with FAI after primary hip arthroscopic surgery with labral repair and femoral osteochondroplasty. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis of a single institution’s database was performed to identify female athletes who underwent primary hip arthroscopic surgery with labral repair and femoral osteochondroplasty from July 2011 to October 2019 with a minimum 5-year follow-up. Preoperative radiographs were evaluated for the lateral center-edge angle, Tonnis angle, Tonnis grade, and alpha angle. Patient-reported outcome measure (PROM) scores, including those for the modified Harris Hip Score, Hip Outcome Score, Tegner Activity Scale, and visual analog scale for pain, as well as patient satisfaction with surgery were analyzed postoperatively. Results: A total of 63 hips (27 left, 36 right) in 56 female patients (mean age, 21.6 ± 8.0 years; mean body mass index, 24.7 ± 4.8 kg/m 2 ) were included and followed for a mean of 8.4 ± 2.1 years (range, 5.0-13.2 years). Preoperatively, patients participated in basketball (n = 18), dance (n = 21), hockey (n = 8), and soccer (n = 12). Of the 56 patients, 41 attempted to return to sport. There were 28 (68%) female athletes who successfully returned to their preoperative sport. Of the total cohort, 21 (38%) patients cited non–hip-related factors for discontinuing their sport. All postoperative PROM scores improved significantly compared with preoperatively ( P ≤ .002) for patients with available preoperative data. Those who returned to sport had significantly improved Hip Outcome Score values compared with those who did not return to sport ( P ≤ .010). Conclusion: Female athletes who underwent primary hip arthroscopic surgery for FAI had significant improvements in PROM scores and moderate return-to-sport rates at a minimum 5-year follow-up. Most athletes discontinued sports because of non–hip-related factors, although hip-related issues were also cited. Our analysis highlights the need for thorough perioperative counseling and establishing appropriate patient expectations for female athletes before hip arthroscopic surgery.

Abstract The acetabular labrum is a fibrocartilaginous structure that deepens the acetabular socket and helps maintain a suction seal. In patients with hip dysplasia, a distinct labral tear pattern called an inside‐out labral tear is often seen. This tear pattern is particularly challenging to correct via conventional techniques since the labrum can potentially remain everted and insufficiently restore the native hip labral suction seal after repair. An inverted hip labral repair technique is performed for this pathology at our institution and focuses on achieving optimal labral orientation to enhance the suction seal and joint stability, particularly in dysplastic hips. This Technical Note aims to describe the key surgical principles and clinical considerations of inverted hip labral repair. Technique Video video See video under supplementary data.

Objectives: To evaluate return-to-sport (RTS) rates and patient reported outcome measures (PROMs) following hip arthroscopy for femoroacetabular impingement (FAI) in active football players with a minimum of 5-years follow-up. Methods: All active football players who underwent hip arthroscopy for FAI from 2010-2019 were identified. Preoperative radiographic measures including lateral center edge angle, Tönnis angle, alpha angle, and acetabular depth were obtained. Patients were evaluated for post-operative RTS and revision surgery data at final follow-up. Modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), HOS Activities of Daily Living (HOS-ADL), HOS Sports Specific Subscale (HOS-Sports), Tegner Activity Scores, Visual Analogue Scale (VAS) for pain, and surgery satisfaction were collected at a minimum 5-year follow-up. Descriptive and comparative statistical analysis was performed using R software (version 4.4.1). Results: Sixty-six hips from 53 male patients were included. The mean age was 20.4 ± 6.4 years and mean BMI was 27.3 ± 6.6 kg/m² (Table 1). Mean follow-up was 8.7 ± 2.8 years. The majority (60%) were high school players and 19% were college players. Figure 1 displays the most commonly affected positions which included wide receiver (32%), defensive lineman (26%), and tight end or offensive lineman (16%). There were 11 bilateral cases and 2 revisions. The mean lateral center edge angle was 31.6º ± 6.4, the mean Tönnis angle was 5.0º ± 5, and the mean alpha angle was 63.2º ± 12.7. There was significant improvement in all PROMs from baseline to a minimum 5-year follow-up (p<0.04). Fifty-four percent of athletes returned to football postoperatively and the average overall surgery satisfaction rating was 8.1/10. Among those who didn’t return, 14% cited hip-related reasons, while 67% cited non-hip related reasons such as priorities changing or graduating (Figure 2). Athletes who returned to football had significantly higher mean HOS-ADL (p=0.049), HOS-Sport (p=0.042), and Tegner level before surgery (p=0.023) compared to those who did not return (Table 2). Conclusions: Football players undergoing hip arthroscopy for FAI demonstrate significant improvements in outcome scores at a minimum 5-year follow-up with a moderate return-to-sport rate. Athletes who are able to return to football report higher patient reported outcomes compared to those who do not. Player position may also influence incidence and outcomes. Although football players demonstrate significant improvements following hip arthroscopy, the moderate RTS rates highlights the demanding nature of the sport and need for improved perioperative counseling.

Objectives: Periacetabular osteotomy (PAO) is utilized for the treatment of hip dysplasia, with a growing trend towards hip arthroscopy at the time of PAO or in a planned, staged manner prior to PAO in order to address intra-articular pathology such as labral tears. For patients with persistent or new pain following isolated PAO, a subset undergo unplanned, primary hip arthroscopy. To date, there is a paucity of available evidence regarding the risk factors for and outcomes of unplanned hip arthroscopy for persistent or new pain after PAO. The purpose of this study was to determine demographic and radiographic characteristics of patients undergoing hip arthroscopy for persistent pain after PAO and also to compare radiographic parameters, surgical characteristics, and postoperative PROMs between patients that underwent hip arthroscopy following PAO and a demographically similar group of controls without acetabular dysplasia that underwent primary hip arthroscopy. Methods: An institutional database of 3014 hip arthroscopies performed between 1988 and 2022 was reviewed for patients having undergone unplanned (i.e. non-staged) first-time hip arthroscopy after PAO. These patients were propensity-matched on a 1:2 ratio with demographically similar, non-dysplastic patients undergoing primary hip arthroscopy with labral repair. All patients were contacted at final-follow-up to collect outcomes including subsequent procedures, progression to THA, and patient-reported outcome measures (PROMs), including modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT), Tegner Activity Scores, Visual Analogue Scale (VAS) for pain, and surgery satisfaction. Demographics, radiographic characteristics, and postoperative outcomes were compared. All statistical analysis and Kaplan-Meier survival curve analysis was performed using R software (version 4.4.1). Results: We identified 22 hips in 21 patients (17 female, 4 male; age: 24.6 ± 8.5 years; BMI: 29.3 ± 7.4 kg/m²) who underwent first-time arthroscopy after ipsilateral PAO and were followed for a mean of 7.2 ± 2.8 years (Table 1). The median post-PAO LCEA was 28° (IQR: 24.6 – 31.7) and the mean Tönnis angle was 4.2° ± 5.9. The median time from the date of PAO to date of subsequent hip arthroscopy was 1.6 years (IQR: 1.1 - 3.4). Compared to the control group, there was a significantly lower rate of femoral osteochondroplasty (50% vs, 86%, p < 0.01), as well as trends towards lower rate of labral repair (77% vs. 95% p = 0.11), and higher rate of capsular repair (64% vs. 75%, p = 0.34). No differences were found between the PAO and control groups in any of the postoperative PROMs (Table 2). Among the PAO patients, 3 (20%) progressed to total hip arthroplasty (THA) compared to 1 (9%) in the control group (p=0.62). Conclusions: Hip arthroscopy after prior PAO was associated with postoperative improvements in pain and moderate rates of conversion to THA. When patients undergoing hip arthroscopy following PAO were compared to a demographically similar matched cohort of nondysplastic hips who underwent primary hip arthroscopy without a prior PAO, similar postoperative outcome scores were observed. This data provides valuable counselling information for clinicians discussing hip arthroscopy in the setting of patients with persistent pain following PAO.

Background: Treatment decisions in patients with anterior cruciate ligament (ACL) injuries are influenced by multiple factors, such as the desire to return to sports or symptomatic instability. Identifying the differential treatment effect of ACL reconstruction (ACLR) compared with nonoperative management on a patient-specific level can inform surgical decision-making. Hypothesis: Unsupervised machine learning can identify distinct patient subgroups based on outcome achievement after ACL injury, and ACLR will exert a protective effect on the development of posttraumatic osteoarthritis (PTOA) over nonoperative management. Study Design: Cohort study; Level of evidence, 3. Methods: A longitudinal populational registry identified patients with ACL injuries from 1990 to 2016 with a minimum 7.5-year follow-up. An unsupervised random forest algorithm was utilized to develop and validate patient subgroups. Treatment effects of ACLR on outcomes were analyzed using a machine learning causal inference estimator. Patient subgroup membership was incorporated into a multivariable logistic regression to identify factors predictive of optimal outcomes. Results: A total of 923 patients (785 primary ACLR, 138 nonoperative) were included. The random forest algorithm arrived at an optimal partition of 2 subgroups, with 653 patients in the optimal outcome subgroup (368 male [56.4%]; mean age, 26.0 ± 10.2 years; mean body mass index [BMI], 26.5 ± 4.30) and 270 patients in the suboptimal outcome subgroup (152 male [56.3%]; mean age, 35.0 ± 10.1 years; mean BMI, 30.5 ± 5.54). The latter group demonstrated significantly increased rates of secondary meniscal injury, development of symptomatic PTOA, and progression to total knee arthroplasty (TKA) at the final follow-up (all P < .01). In the optimal outcome subgroup, ACLR had significantly protective treatment effects on the risk of secondary meniscal injury (average treatment effect [ATE], 61%), contralateral ACL injury (ATE, 8%), symptomatic PTOA (ATE, 16%), and progression to TKA (ATE, 6%) (all P < .01). Conversely, in the suboptimal outcome subgroup, ACLR only protected against symptomatic PTOA (ATE, 11%) and progression to TKA (ATE, 8%) (both P < .01). Conclusion: Two clinically meaningful subgroups were identified from retrospectively collected data and found to experience differential treatment responses after ACL injuries. ACLR decreased the rate of development of PTOA and TKA in both subgroups but was not as effective in preventing secondary meniscal injuries or contralateral ACL injuries in patients who were older, heavier, or had concomitant medial meniscus injuries.