The utility of hip arthroscopy for patients with painful borderline hip dysplasia

Outcomes of Painful Hips After Hip Arthroscopy Surgery for Femoroacetabular Impingement

The benefits of hip arthroscopic surgery for femoroacetabular impingement are well-established. Hip arthroscopic surgery rates have risen dramatically over the last decade. Some patients, however, may continue to experience hip symptoms after surgery and are dissatisfied with their inability to return to desired optimal activity levels. The purpose of the study is to understand the long-term outcomes of patients with painful hips after hip arthroscopy for femoroacetabular impingement. This is a retrospective study of the outcomes of painful hips after hip arthroscopy for femoroacetabular impingement, with four to 14-year follow-up from 2008 to 2022. A total of 84 hip arthroscopies were performed. Most of the patients had labral tear debridement and shaving of the aspherical femoral head also known as cam lesion, and five patients had repair for labral tear. There were eight patients who had bilateral hip involvement. There were 27 men and 57 females between the second to fifth decades. The electronic patient's records and radiological images were reviewed, and patient outcomes were graded as pain-free hip (asymptomatic) or painful hip (persistent pain and symptoms of instability). After hip arthroscopy surgery, 55% (46) of hips were graded pain-free in patients who were mostly in their 20s and 30s, while 45% (38) of hips had persistent pain. These patients were in their third or fifth decade. In the painful hip cohort, 33 patients had one hip arthroscopic surgery, while five patients had multiple repeat hip arthroscopies in the same hip over a three to six-year period. Bilateral hip arthroscopies were performed at different times in eight patients of which five individuals experienced painful hip outcomes. There were seven females and one male in their 30s and 40s. The labral tear was repaired in five patients, and two patients had painful hip outcomes. Both were females in their 20s and 30s. Patients with chronic painful hips after hip arthroscopic surgery were investigated to identify the cause of the pain. If no cause was established, then they were finally referred to pain specialist clinicians for pain management. This cohort had seven patients between 28 and 43 years. Six were female and one was male. Total hip replacement (THR) was performed in four patients (4.7%). Conversely, 95.3% of patients did not need THR during the study period of 14 years. Hip arthroscopy can be an effective treatment for femoroacetabular impingement. Careful patient selection and a holistic approach are vital for a good patient outcome. The success rate of the pain-free hip after hip arthroscopy decreases with increasing age of the patient, particularly in the female gender. Patients with grade II and more degenerative chondral changes do not perform well. Patients in their fourth and fifth decade can benefit from hip arthroscopy provided a comprehensive discussion of the expected outcomes is conducted prior to surgery. Overall, hip arthroscopy remains a valuable tool, but it is important to be conscious of its limitations and potential challenges.

Dysplastic Hips Have Decreased Iliofemoral Ligament Thickness on Coronal Sequences in Magnetic Resonance Imaging: A Matched Cohort Analysis

PURPOSE

To characterize hip capsule thickness on advanced imaging in patients with and without hip dysplasia and to also evaluate differences in capsular thickness between patients with borderline and patients with true dysplasia.

METHODS

Patients evaluated by the senior author for concerns of hip pathology from June 2020 to June 2021 were queried and images reviewed to determine dysplasia status by lateral center-edge angle (LCEA) ≤25°. A group of patients without dysplasia was identified and matched for age, sex, and body mass index. Hip capsular thickness was quantified using magnetic resonance imaging. A subanalysis was conducted to compare patients with true dysplasia (LCEA < 20°) with patients with borderline dysplasia (LCEAs between 20° and 25°). The analysis included independent samples t tests, χ2 tests, and multivariable regression.

RESULTS

A total of eighty patients were included, with a mean age of 31.8 ± 11.7 years, a mean body mass index of 26.6 ± 6.5 points, and 70% (56) female patients. Patients with dysplasia had a mean LCEA of 19.8 ± 4.3°. Patients with dysplasia had decreased capsular thickness compared with patients without dysplasia (2.75 ± 0.96 mm vs 3.52 ± 1.22 mm, P = .003). Multivariable regression showed decreased capsular thickness associated with decreased LCEAs (β = 2.804, R = 0.432, P < .001) and dysplasia (β = -0.709, R2 = 0.056, P = .004). Results of a subanalysis of the dysplastic group examining differences between accepted definitions of borderline dysplasia and true dysplasia showed no significant differences in capsular thickness between the 2 groups (P = .379).

CONCLUSIONS

Patients with hip dysplasia were found to have thinner iliofemoral ligaments in the coronal plane on magnetic resonance imaging on magnetic resonance imaging. Further investigation is needed to evaluate any potential implications with hip instability, given the thinner hip capsule demonstrated in this study.

LEVEL OF EVIDENCE

Level III, retrospective comparative prognostic trial.

Primary and Revision Hip Arthroscopy in Borderline Hip Dysplasia Shows Comparable Outcomes at a Minimum 5-Year Follow-Up

PURPOSE

To compare patient-reported outcomes (PROs), achievement of clinically significant outcomes, and reoperation-free survivorship between primary and revision hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS) in propensity-matched borderline hip dysplasia (BHD) patients at a minimum 5-year follow-up.

METHODS

Patients with BHD, characterized by a lateral center-edge angle 18° to 25°, who underwent HA for FAIS with capsular repair by a single surgeon between January 2012 and June 2018 with a minimum 5-year follow-up were identified. Cases of revision HA were propensity-matched 1:2 to cases of primary HA, controlling for age, sex, and body mass index. A 1:2 ratio was chosen to maximize the number of included patients. Collected PROs included Hip Outcome Score-Activities of Daily Living and Sport Subscales, International Hip Outcome Score 12, modified Harris Hip Score, and Visual Analog Scale for Pain. Achievement of minimal clinically important difference, patient acceptable symptom state, and substantial clinical benefit for any measured PRO was compared between groups along with reoperation-free survivorship using Kaplan-Meier analysis.

RESULTS

Thirty-six revision HA hips (34 patients) were propensity-matched to 72 primary HA hips (70 patients). The groups were similar in age (31.5 ± 10.3 years vs 30.5 ± 11.2, P = .669), sex (69.4% female vs 70.8%, P = .656), and body mass index (25.7 ± 4.0 vs 25.5 ± 3.7, P = .849). The revision group showed a greater prevalence of prolonged preoperative pain (50.0% vs 27.8%, P = .032) compared with the primary group. A significant improvement in all PROs was observed for both groups with comparable PROs preoperatively and at the 5-year follow-up between groups (P ≥ .086). The revision and primary groups showed comparable minimal clinically important difference (95.0% vs 95.7%, P ≥ .999), patient acceptable symptom state (80.0% vs 83.6%, P = .757), and substantial clinical benefit (62.5% vs 70.7%, P = .603) achievement for any PRO. Comparable reoperation-free survivorship was observed (P = .151).

CONCLUSIONS

Propensity-matched patients with BHD undergoing primary and revision hip arthroscopy for FAIS achieved similar minimum 5-year PROs, clinically significant outcomes, and reoperation-free survivorship.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.

Borderline Hip Dysplasia Is Not Associated With Significant Differences in Hip Survivorship or Patient-Reported Outcomes Following Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Propensity-Matched Cohort Study

PURPOSE

To compare hip survivorship and patient-reported outcomes after primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) in patients with versus without comorbid borderline hip dysplasia (BHD) at 2-year follow-up.

METHODS

A retrospective matched-cohort study was conducted involving patients who underwent primary hip arthroscopy for FAIS with a single surgeon from 2010 to 2019. BHD was defined as lateral center edge angle (LCEA) of 20 to 25°. Subjects with BHD were matched 1:2 to controls without BHD on age, sex, body mass index, and preoperative modified Harris Hip Score (mHHS). Alpha angle, LCEA, Tönnis angle, and acetabular retroversion signs were measured on preoperative and/or postoperative hip radiographs. Patient-reported outcomes were assessed using the mHHS and the Non-Arthritic Hip Score. Hip survivorship, outcome scores, and achievement of the minimum clinically important difference were compared between groups using the Mann-Whitney U test or Fisher exact test, as appropriate. P values <.05 were considered significant.

RESULTS

Thirty-one BHD subjects (mean age 36.8 years, 71.0% female) and 62 controls (mean age 38.0 years, 71.0% female) were included. There were no significant intergroup differences in demographics or preoperative radiographic measurements besides LCEA and Tönnis angle (all P > .05). Intraoperatively, subjects with BHD were found to have significantly shorter labral tears (mean 2.6 vs 2.8 clock-face hours, P = .048), but there were no significant intergroup differences in acetabular or femoral cartilage status (all P > .05). Postoperatively, there were no significant intergroup differences in rates of revision arthroscopy (BHD 6.5% vs control 11.3%) or conversion to total hip arthroplasty (BHD 9.7% vs control 1.6%), in 2-year improvement of the mHHS and Non-Arthritic Hip Score, or in minimum clinically important difference achievement rates (all P > .05).

CONCLUSIONS

BHD is not associated with a significant difference in hip survivorship or patient-reported outcomes following primary hip arthroscopy for FAIS.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Mid- and Long-Term Outcomes Are Favorable for Patients With Borderline Dysplasia Undergoing Primary Hip Arthroscopy: A Systematic Review

PURPOSE

To evaluate midterm outcomes, long-term outcomes, and survivorship in the borderline dysplastic population after primary hip arthroscopy.

METHODS

A systematic review of current literature was performed with the following key words: "hip, "arthroscopy," "borderline dysplasia," "borderline hip dysplasia," "developmental dysplasia," "ten-year," "survivorship," "10-year," "5-year," "five year," "mid-term," "long-term," "outcomes," "arthroscopic," and "femoroacetabular impingement" in PubMed, Cochrane, and Scopus in March 2022 using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The following information was recorded: title, author, publication date, study design, demographic, number of hips, follow-up time, study period, indications for hip arthroscopy, patient-reported outcomes (PROs), characteristics of patients converting to total hip arthroplasty (THA), and rates of secondary surgeries and conversion to THA were recorded. Survivorship was defined as not converting to THA. Kappa values for the title/abstract and full-text screening were calculated. Forest plots were created for PROs that were included in 3 or more studies.

RESULTS

Six articles comprising 413 hips were included in the study. Three studies were Level III evidence, and 3 studies were Level IV evidence. Average follow-up ranged from 5.7 to 12.2 years. One study defined borderline hip dysplasia as lateral center-edge angle 18-25° and 5 defined it as lateral center-edge angle 20-25°. All studies included PROs and reported significant improvement after surgery in at least one PRO. Three studies reported clinical benefit and across the studies at least 70% of patients achieved minimum clinically important difference in at least one PRO. Rates of undergoing revision hip arthroscopy and THA ranged from 2.1% to 7% and 0% to 24%, respectively. Tönnis grade 2, Tönnis angle >15, and Outerbridge Grade IV cartilage damage were identified as predictors of conversion to THA.

CONCLUSIONS

Patients with borderline hip dysplasia undergoing primary hip arthroscopy demonstrated significant improvement in PROs at midterm and long-term follow-up. Survivorship at midterm follow-up was 98.2% (328/334 hips) and 76.3% (29/38 hips) at long-term follow-up.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and Level IV studies.

Ten-Year Outcomes After Hip Arthroscopy in Patients With Femoroacetabular Impingement and Borderline Dysplasia

BACKGROUND

The role of hip arthroscopy in the treatment of patients with borderline hip dysplasia is controversial and evolving.

PURPOSE

To evaluate outcomes at a minimum 10-year follow-up in patients who underwent hip arthroscopy for femoroacetabular impingement in a hip with borderline dysplasia.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All hips that underwent labral repair between June 2006 and March 2009 for femoroacetabular impingement with borderline dysplasia were included if they had a lateral center-edge angle of 20° to 25°, had primary hip arthroscopy for the diagnosis of femoroacetabular impingement, and were aged 18 to 70 years. Patients were excluded if they had previous hip surgery, avascular necrosis, or fracture. Kaplan-Meier survivorship was performed, with survivorship defined as avoidance of conversion to total hip arthroplasty (THA).

RESULTS

A total of 45 patients met the inclusion criteria, and 38 were contacted at a minimum 10 years postoperatively (84%; mean ± SD, 12 ± 1.3 years). There were 23 women and 15 men with an average age of 41 ± 9.6 years (range, 25-69). Twenty patients were ≥40 years of age. In this patient cohort, survivorship was 87% at 5 years and 79% at 10 years for conversion to THA. Of the 38 patients included, 9 were converted to THA (24%), and 3 required revision hip arthroscopy (7%). Patient age, Tönnis grade, microfracture of cartilage lesions, and Tönnis angle >15° were associated with conversion to THA. No statistically significant differences were found between those who underwent conversion to THA and those who did not regarding lateral center-edge angle, Sharp angle, or alpha angle. Significant improvements were seen at follow-up of 12 years (range, 10-13) for the modified Harris Hip Score (58 to 83; P = .002), Hip Outcome Score-Activities of Daily Living (70 to 87; P = .003), Hip Outcome Score-Sport (47 to 76; P = .004), and Western Ontario and McMaster Universities Osteoarthritis Index (31 to 10; P = .001). At follow-up, >80% maintained the minimal clinically important difference for the Hip Outcome Score (Activities of Daily Living and Sport) with no differences between patients aged <40 and ≥40 years.

CONCLUSION

Risk factors for conversion to THA after hip arthroscopy in the borderline dysplastic hip included older age, higher Tönnis grades, grade 4 chondral lesions that were microfractures, and Tönnis angle >15°. In those patients who did not convert to THA, improvement in outcome measures was seen at 10 years. Careful patient selection is critical to the success of this procedure.