Early Functional Outcomes of Periacetabular Osteotomy After Failed Hip Arthroscopic Surgery for Symptomatic Acetabular Dysplasia

Periacetabular osteotomy with and without concomitant arthroscopy: a systematic review of evidence on post-operative activity levels and return to sport

The purpose of this systematic review is to (i) compare post-operative activity levels after periacetabular osteotomy (PAO) versus PAO + HA (concomitant PAO and hip arthroscopy) using patient-reported outcomes that specifically assess activity and sports participation [Hip Disability and Osteoarthritis Outcome Score-Sport and Recreation subscale (HOOS-SR), University of California Los Angeles (UCLA) activity score, Hip Outcome Score-Sport-Specific Subscale (HOS-SSS)] and (ii) compare post-operative return to sport (RTS) data between PAO and PAO + HA groups. A systematic review of literature was conducted on 1 June 2023, utilizing PubMed, Cochrane and Embase (OVID). Articles were screened for inclusion using specific inclusion and exclusion criteria. Twenty-six out of 1610 articles met all inclusion criteria, without meeting any exclusion criteria. In the 12 studies containing only subjects who underwent PAO alone, 11 demonstrated an average score improvement in UCLA, HOOS-SR or HOS-SSS post-operatively (P < 0.05). In the three studies containing subjects who underwent PAO with concomitant HA, significant improvements were seen in the HOS-SS and UCLA scores (P < 0.05). In the five studies that directly compared UCLA, HOS-SSS and HOOS-SSS scores between PAO groups and PAO + HA groups, all demonstrated statistically significant improvement post-operatively (P < 0.05). The rate of RTS ranged from 63% to 90.8% among PAO studies and was found to be 81% in the single PAO + HA study that assessed RTS. When performed in patients with intra-articular pathology, concomitant PAO + HA may provide similar sport-related outcomes to PAO alone in patients without intra-articular pathology.

A Modified Approach to Measuring Femoro-Epiphyseal Acetabular Roof Index Has Better Intraobserver and Interobserver Reliability Compared With the Original Femoro-Epiphyseal Acetabular Roof Index

PURPOSE

To propose a modified approach to measuring the femoro-epiphyseal acetabular roof (FEAR) index while still abiding by its definition and biomechanical basis, and to compare the intra- and interobserver reliabilities of the original and the modified FEAR index. To propose a classification for medial sourcil edges.

METHODS

We retrospectively reviewed a consecutive series of patients treated with periacetabular osteotomy and/or hip arthroscopy at a single institute. Patients with unilateral or bilateral symptomatic borderline hip(s) were included. Hips with remarkable osteoarthritis, deformities, history of previous surgery, or without symptoms were excluded. A modified FEAR index was defined using a best-fit circle to determine the sourcil line and 2 ancillary lines connecting femoral head and sourcil edges to determine epiphyseal line. Lateral center-edge angle, Sharp angle, Tönnis angle on all hips, as well as FEAR index with original and modified approaches, were measured. Intra- and interobserver reliability were calculated as intraclass correlation coefficients (ICCs) for the FEAR index with both approaches and other alignments. A classification was proposed to categorize medial sourcil edges. ICCs for the 2 approaches across different sourcil groups also were calculated.

RESULTS

After we reviewed 411 patients, 49 were finally included. Thirty-two patients (40 hips) were identified as having borderline dysplasia defined by a lateral center-edge angle of 18 to 25°. Intraobserver ICCs for the modified method were good to excellent for borderline hips; poor to excellent for developmental dysplasia of the hip; and moderate to excellent for normal hips. As for interobserver reliability, the modified approach outperformed original approach with moderate-to-good interobserver reliability (developmental dysplasia of the hip group, ICC = 0.650; borderline dysplasia group, ICC = 0.813; normal hip group, ICC = 0.709). The medial sourcil edge was classified to 3 groups upon its morphology. Type II (39.0%) and III (43.9%) sourcil were the dominant patterns. The sourcil classification had substantial intraobserver agreement (observer 4, kappa = 0.68; observer 1, kappa = 0.799) and moderate interobserver agreement (kappa = 0.465). The modified approach to FEAR index possessed greater interobserver reliability in all medial sourcil edge patterns.

CONCLUSIONS

The modified FEAR index has better intra- and interobserver reliability compared with the original approach in all hip groups and sourcil groups. Type II and III sourcil types account for the majority, to which the modified approach is better.

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria (consecutive patients with consistently applied reference standard and blinding).

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.

Pain, function and quality of life are impaired in adults undergoing periacetabular osteotomy (PAO) for hip dysplasia: a systematic review and meta-analysis

BACKGROUND

Hip dysplasia is a common condition in active adults with hip pain that can lead to joint degeneration. Periacetabular osteotomy (PAO) is a common surgical treatment for hip dysplasia. The effect of this surgery on pain, function and quality of life (QOL) has not been systematically analysed.

PURPOSE

In adults with hip dysplasia: (1) evaluate differences in pain, function and QOL in those undergoing PAO and healthy controls; (2) evaluate pre- to post-PAO changes in pain, function and QOL; (3) evaluate differences in pain, function and QOL in those with mild versus severe dysplasia, undergoing PAO; and (4) evaluate differences in pain, function and QOL in those having primary PAO versus those with previous hip arthroscopy.

METHODS

A comprehensive, reproducible search strategy was performed on 5 different databases. We included studies that assessed pain, function and QOL in adults undergoing PAO for hip dysplasia, using hip-specific patient reported outcomes measures.

RESULTS

From 5017 titles and abstracts screened, 62 studies were included. Meta-analysis showed PAO patients had worse outcomes pre- and post-PAO compared to healthy participants. Specifically, pain (standardised mean difference [SMD] 95% confidence interval [CI]): -4.05; -4.78 to -3.32), function (-2.81; -3.89 to -1.74), and QOL (-4.10; -4.43 to -3.77) were significantly poorer preoperatively.Meta-analysis found patients experienced improvements following PAO. Pain improved from pre-surgery to 1-year (standardised paired difference [SPD] 1.35; 95% CI, 1.02-1.67) and 2 years postoperatively (1.35; 1.16-1.54). For function, the activities of daily living scores at 1 year (1.22; 1.09-1.35) and 2 years (1.06; 0.9-1.22) and QOL at 1 year (1.36; 1.22-1.5) and 2 years (1.3; 1.1-1.5) all improved. No difference was found between patients undergoing PAO with mild versus severe dysplasia.

CONCLUSIONS

Before undergoing PAO surgery, adults with hip dysplasia have worse levels of pain, function and QOL compared to healthy participants. These levels improve following PAO, but do not reach the same level as their healthy participants.

REGISTRATION

PROSPERO (CRD42020144748).

Evaluating the Use of PROMs in Paediatric Orthopaedic Registries

Patient-reported outcome measures (PROMs) provide structured information on the patient's health experience and facilitate shared clinical decision-making. Registries that collect PROMs generate essential information about the clinical course and efficacy of interventions. Whilst PROMs are increasingly being used in adult orthopaedic registries, their use in paediatric orthopaedic registries is not well known. The purpose of this systematic review was to identify the frequency and scope of registries that collect PROMs in paediatric orthopaedic patient groups. In July 2023, six databases were systematically searched to identify studies that collected PROMs using a registry amongst patients aged under 18 years with orthopaedic diagnoses. Of 3190 identified articles, 128 unique registries were identified. Three were exclusively paediatric, 27 were majority paediatric, and the remainder included a minority of paediatric patients. One hundred and twenty-eight registries collected 72 different PROMs, and 58% of these PROMs were not validated for a paediatric population. The largest group of orthopaedic registries collected PROMs on knee ligament injuries (21%). There are few reported dedicated orthopaedic registries collecting PROMs in paediatric populations. The majority of PROMs collected amongst paediatric populations by orthopaedic registries are not validated for patients under the age of 18 years. The use of non-validated PROMs by registries greatly impedes their utility and impact. Dedicated orthopaedic registries collecting paediatric-validated PROMs are needed to increase health knowledge, improve decision-making between patients and healthcare providers, and optimise orthopaedic management.

[Hip dysplasia: What influence do age, arthrosis and concomitant diseases have on the treatment result?]

Pelvic osteotomies are an established treatment for symptomatic adult hip dysplasia with a promising long-term outcome. Results depend not only on the achieved acetabular reorientation but also on patient-factors like preoperative joint condition (degree of osteoarthritis and joint congruency) and age. Additionally, the diagnosis and appropriate therapy of impingement-associated hip deformities is essential in order to achieve good mid- and long-term outcomes. The influence of chondrolabral pathology on the outcome of pelvic osteotomies is not yet defined. Symptomatic patients with residual dysplasia after previous pelvic or acetabular osteotomies can benefit from an additional osteotomy, although results can be worse in comparison to prior unoperated joints. Obesity can make surgery more demanding and increases the complication profile of PAO, although it has no influence on the postoperative outcome. Regarding the overall prognosis after an osteotomy, the consideration of combined risk factors is superior to the concentration on individual factors alone.

Use of Anatomic Radiographic Horizons for the Lateral Center-Edge Angle in the Classification of Hip Dysplasia

BACKGROUND

The lateral center-edge angle of Wiberg (LCEA) and Tönnis angle (TA) rely on a "horizon" that functions as a reference point for measurements of hip dysplasia on weightbearing anteroposterior pelvis radiographs. There are 3 different horizons that are currently utilized depending on surgeon preference: (1) a line parallel to the radiographic floor (F), (2) a line that connects the inferior portions of the acetabular teardrops (ATs), or (3) a line that connects the ischial tuberosities (ITs). It is imperative to accurately assess the degree of hip dysplasia on initial workup to select the appropriate surgical intervention.

PURPOSE

To assess how the choice of a radiographic horizon affects the measurements of the LCEA and TA. The secondary purpose was to assess how the horizon affected the classification of hips as either normal, borderline dysplastic, or dysplastic.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

The LCEA and TA were measured on all preoperative weightbearing anteroposterior pelvis radiographs for 186 consecutive patients who underwent hip preservation surgery between February 2016 and November 2020 (140 hip arthroscopic procedures, 46 combined hip arthroscopic procedures with periacetabular osteotomy), 3 times per hip, each time using an F, AT, and IT horizon. The Student t test was used to analyze the differences in the measurements of the LCEA and TA, and discordance rates in the dysplasia classification between horizons were quantified.

RESULTS

For the entire study population, the mean LCEA_F (23.4°± 7.4°) was significantly greater than the mean LCEA_IT (23.1°± 7.2°) (95% CI, -0.634 to -0.003; P = .047) and mean LCEA_AT (23.0°± 7.1°) (95% CI, -0.723 to -0.139; P = .004). There was no difference between the LCEA_IT and LCEA_AT (95% CI, -0.305 to 0.080; P = .251). When stratified by hip arthroscopic surgery, the mean LCEA_F (26.3°± 5.6°) was significantly greater than the mean LCEA_AT (25.8°± 5.3°) (95% CI, -0.845 to -0.162; P = .004). Overall, there was a 17.7% and 18.3% discordance rate in the dysplasia classification using the LCEA_IT and LCEA_AT compared with the LCEA_F, respectively. There were no statistically significant differences between the mean TA_IT, TA_AT, and TA_F for the entire study population, the arthroscopic surgery group, and the combined arthroscopic surgery and periacetabular osteotomy group.

CONCLUSION

There was no statistical difference between the AT and IT horizons for LCEA measurements. The dysplasia classification was in better agreement between the 2 anatomic horizons compared with the F horizon. The TA was not affected by changes in the horizon.

Periacetabular osteotomy to treat hip dysplasia: a systematic review of harms and benefits

INTRODUCTION

Periacetabular osteotomy (PAO) is often performed in patients with hip dysplasia. The aim of this systematic review and meta-analysis was to evaluate the harms and benefits of PAO in patients with hip dysplasia in studies reporting both adverse events and patient-reported hip pain and function.

MATERIALS AND METHODS

A systematic search combing PAO and patient-reported outcomes was performed in the databases MEDLINE, CINAHL, EMBASE, Sports Discuss and PsychINFO. Studies including both harms and benefits defined as adverse events and patient-reported hip pain and function were included. Risk of bias was assessed using The Cochrane Risk of Bias In Non-Randomized Studies - of Interventions.

RESULTS

Twenty-nine cohort studies were included, of which six studies included a comparison group. The majority of studies had serious risk of bias and the certainty of evidence was very low. The proportion of adverse events was 4.3 (95% CI 3.7; 4.9) for major adverse events and 14.0 (95% CI 13.0; 15.1) for minor adverse events. Peroneal nerve dysfunction was the most frequent adverse event among the major adverse events, followed by acetabular necrosis and delayed union or non-union. All patient-reported hip pain and function scores improved and exceeded the minimal clinically important differences after PAO. After 5 years, scores were still higher than the preoperative scores.

CONCLUSION

PAO surgery has a 4% risk of major, and 14% risk of minor adverse events and a positive effect on patient-reported hip pain and function among patients with hip dysplasia.

Periacetabular osteotomy after failed hip arthroscopy demonstrates improved outcomes in a heterogenous patient population: a systematic review

PURPOSE

To evaluate the literature on patients undergoing periacetabular osteotomy after failed hip arthroscopy (PAO-FHA) for (1) patient demographics and hip morphology, (2) changes in preoperative to postoperative patient-reported outcomes (PROs), and (3) PROs in comparison to primary periacetabular osteotomy (PAO) patients.

METHODS

A systematic literature search of Pubmed, CINAHL/Medline, and cochrane databases was performed in accordance with PRISMA guidelines. The search phrase was "(periacetabular osteotomy or PAO or rotational osteotomy) and (hip arthroscopy or arthroscopic)". The titles, abstracts, and full texts were screened for studies on PAO-FHA. Study quality was assessed, and relevant data were collected. A meta-analysis was not performed due to study heterogeneity.

RESULTS

The search identified 7 studies, including 151 hips (148 patients, 93.9% female) undergoing PAO-FHA, out of an initial 593 studies, with three Level IV and four Level III studies. Mean time from hip arthroscopy to PAO ranged from 17.0 to 29.6 months. Heterogenous hip morphologies and radiologic findings prior to PAO were observed, though patients most frequently demonstrated moderate-to-severe dysplasia (mean or median lateral center edge angle < 20°) and minimal osteoarthritis (Tönnis grade 0 or 1). In all 5 studies that reported concomitant procedures with PAO, femoral and/or acetabular osteoplasty was performed via arthroscopy or arthrotomy. Following PAO-FHA, radiographic acetabular coverage and PROs improved in all 6 studies that reported postoperative outcomes. All four comparative studies of primary PAO vs. PAO-FHA included patients with mean or median LCEAs < 20°, reporting mixed outcomes for the optimal treatment approach.

CONCLUSION

PAO-FHA is reported in a heterogenous patient population that frequently includes hips with moderate-to-severe dysplasia and minimal osteoarthritis. Regardless of hip morphology or concomitant procedures, all studies that reported postoperative outcomes demonstrated improved PROs following PAO-FHA.

LEVEL OF EVIDENCE

Level IV.

A comparison of 6-month outcomes between periacetabular osteotomy with concomitant hip arthroscopy to isolated hip arthroscopy for femoroacetabular impingement

PURPOSE

To compare early outcomes of periacetabular osteotomy (PAO) with concomitant hip arthroscopy to isolated hip arthroscopy for femoroacetabular impingement (FAI) and chondrolabral pathology using patient-reported outcomes measurement information system (PROMIS).

MATERIALS AND METHODS

Consecutive patients scheduled for PAO with concomitant hip arthroscopy (PAO + HA) or isolated hip arthroscopy (HA) between the ages of 15 and 30 years old were prospectively included in the study. Based on power analysis, subjects were recruited until there were 22 subjects in the PAO + HA group. These subjects were then gender matched to the HA group. The PROMIS, with six subscales and two global health measures, were completed during preoperative and 6-month follow-up visits. One-way ANOVA was performed to compare intake information of age, symptom duration, body mass index, and Beighton scores as well as preoperative and 6-month postoperative PROMIS scores between the PAO + HA and HA.

RESULTS

22 consecutive subjects undergoing PAO + HA were all females (average age 20.0 years) and matched to 22 consecutive females (average age 22.6) in the HA group. ANOVA did not find a significant difference between the two groups when comparing intact information, with exception of age (p = 0.04). A significant difference was also not identified (p ≥ 0.05) between the two groups on preoperative or 6-month postoperative PROMIS scores. The largest difference in 6-month postoperative scores between the two groups was 4.4 points on physical function subscale.

CONCLUSION

Outcomes at 6 months were not significantly different when comparing PAO + HA to HA for FAI and chondrolabral pathology in females under 30 years of age. The more extensive surgery with a prolonged protective period associated with PAO do not seem to negatively impact outcomes at 6 months when compared to HA. These finding support the use of PAO + HA, particularly if the patient and/or surgeon were concerned about prolonged disability, metal health issues, and/or higher pain levels that might be associated with the PAO procedure.

Return to Sport in Athletes With Borderline Hip Dysplasia After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

BACKGROUND

Data on outcomes in patients with borderline hip dysplasia (BHD) who undergo hip arthroscopy remain limited, particularly in regard to return to sport (RTS).

PURPOSE

To evaluate outcomes in patients with BHD and their ability to RTS after hip arthroscopy for treatment of femoroacetabular impingement syndrome (FAIS).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Consecutive patients with self-reported athletic activity and radiographic evidence of BHD, characterized by a lateral femoral center-edge angle (LCEA) between 18° and 25° and a Tönnis angle >10°, who underwent hip arthroscopy for FAIS between November 2014 and March 2017 were identified. Patient characteristics and clinical outcomes including the Hip Outcome Score-Activities of Daily Living (HOS-ADL), Hip Outcome Score-Sports Subscale (HOS-SS), modified Harris Hip Score (mHHS), international Hip Outcome Tool (iHOT-12), and visual analog scale (VAS) for pain and satisfaction were analyzed at minimum 2-year follow-up. In addition, all patients completed an RTS survey.

RESULTS

A total of 41 patients with a mean age and body mass index (BMI) of 29.6 ± 13.4 years and 25.3 ± 5.6, respectively, were included. Mean LCEA and Tönnis angle for the study population were 22.7°± 1.8° and 13.3°± 2.9°, respectively. A total of 31 (75.6%) patients were able to RTS after hip arthroscopy at a mean of 8.3 ± 3.2 months. A total of 14 patients (45.2%) were able to RTS at the same level of activity, 16 patients (51.6%) returned to a lower level of activity, and only 1 (3.2%) patient returned to a higher level of activity. Of the 11 high school and collegiate athletes, 10 (90.9%) were able to RTS. All patients demonstrated significant improvements in all patient-reported outcome measures (PROMs) as well as in pain scores at a mean of 26.1 ± 5.4 months after surgery. Patients who were able to RTS had a lower preoperative BMI than patients who did not RTS. Analysis of minimum 2-year PROMs demonstrated better HOS-ADL, HOS-SS, mHHS, iHOT-12, and VAS outcomes for pain in patients able to RTS versus those who did not RTS (P < .05).

CONCLUSION

Of the patients with BHD studied here, 75.6% of patients successfully returned to sport at a mean of 8.3 ± 3.2 months after hip arthroscopy for FAIS. Of the patients who successfully returned to sport, 45.2% returned at the same level, and 3.2% returned at a higher activity level.

Predicting the Risk of Subsequent Hip Surgery Before Primary Hip Arthroscopy for Femoroacetabular Impingement Syndrome: A Machine Learning Analysis of Preoperative Risk Factors in Hip Preservation

BACKGROUND

The number of patients requiring reoperation has increased as the volume of hip arthroscopy for femoroacetabular impingement syndrome (FAIS) has increased. The factors most important in determining patients who are likely to require reoperation remain elusive.

PURPOSE

To leverage machine learning to better characterize the complex relationship across various preoperative factors (patient characteristics, radiographic parameters, patient-reported outcome measures [PROMs]) for patients undergoing primary hip arthroscopy for FAIS to determine which features predict the need for future ipsilateral hip reoperation, namely, revision hip arthroscopy, total hip arthroplasty (THA), hip resurfacing arthroplasty (HRA), or periacetabular osteotomy (PAO).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A cohort of 3147 patients undergoing 3748 primary hip arthroscopy procedures were included from an institutional hip preservation registry. Preoperative computed tomography of the hip was obtained for each patient, from which the following parameters were calculated: the alpha angle; the coronal center-edge angle; the neck-shaft angle; the acetabular version angle at 1, 2, and 3 o'clock; and the femoral version angle. Preoperative PROMs included the modified Harris Hip Score (mHHS), the Hip Outcome Score (HOS)-Activities of Daily Living subscale (HOS-ADL) and the Sport Specific subscale, and the international Hip Outcome Tool (iHOT-33). Random forest models were created for revision hip arthroscopy, the THA, the HRA, and the PAO. Area under the curve (AUC) for the receiver operating characteristic curve and accuracy were calculated to evaluate each model.

RESULTS

A total of 171 patients (4.6%) underwent subsequent hip surgery after primary hip arthroscopy for FAIS. The AUC and accuracy, respectively, were 0.77 (fair) and 76% for revision hip arthroscopy (mean, 26.4-month follow-up); 0.80 (good) and 81% for THA (mean, 32.5-month follow-up); 0.62 (poor) and 69% for HRA (mean, 45.4-month follow-up); and 0.76 (fair) and 74% for PAO (mean, 30.4-month follow-up). The most important factors in predicting reoperation after primary hip arthroscopy were higher body mass index (BMI) and lower preoperative HOS-ADL for revision hip arthroscopy, greater age and lower preoperative iHOT-33 for THA, increased BMI for HRA, and larger neck-shaft angle and lower preoperative mHHS for PAO.

CONCLUSION

Despite the low failure rate of hip arthroscopy for FAIS, our study demonstrated that machine learning has the capability to identify key preoperative risk factors that may predict subsequent ipsilateral hip surgery before the index hip arthroscopy. Knowledge of these demographic, radiographic, and patient-reported outcome data may aid in preoperative counseling and expectation management to better optimize hip preservation.

Arthroscopic treatment for femoroacetabular impingement syndrome (FAIS) in adolescents—5-year follow-up

To report the minimum 5-year outcome after hip arthroscopy with labral repair in adolescents. From 2011 to 2014, 29 consecutive patients with a mean age 16.3 years (range 12.7–19.8 years) underwent hip arthroscopy treatment for femoroacetabular impingement syndrome. Patient-related outcome measures (PROMs) including modified Harris Hip Score (mHHS), Visual Analog Scale (VAS) for pain and Copenhagen Hip and Groin Outcome Score (HAGOS) were used preoperatively and at follow-up (FU). Percentage of patients achieving minimum clinically important difference (MCID) and substantial clinical benefit (SCB) for mHHS and HAGOS were determined. Mean FU was 6.7 years (range 5–9.6 years), and a 100% FU was accomplished. Significant improvements were seen for all PROMs at FU in patients not having a periacetabular osteotomy (PAO) with VAS pain score improving from mean 62 to 9, mHHS from 58 to 94 and HAGOS improved in all subgroups. For mHHS, SCB changes were achieved by 76% and MCID by 76% of the patients. Percentage of patients achieving MCID for HAGOS subgroups were 81% for pain, 67% for symptoms, 76% for physical function in daily living, 76% for physical function in sport and recreation, 81% for participation in physical activities and 81% for hip-related quality of life. Two patients had revision hip arthroscopy. PAO was later performed in three patients. The risk of further surgery with center edge (CE) bony edge (CEB) <30° was 42% and 0% with CEB ≥30°. Adolescents having hip arthroscopy with labral repair and resection of cam and pincer morphology achieve significant improvements at mean 6.7 years of FU. CEB < 30° increases the risk of further surgery.

Standardizing the Diagnostic Evaluation of Nonarthritic Hip Pain Through the Delphi Method

Background:

Femoroacetabular impingement and acetabular dysplasia have gained increased attention as nonarthritic sources of pain and dysfunction in young, active patients. To date, no standardized approach to the diagnostic evaluation of nonarthritic hip pain has been identified, as previous work has focused on the diagnostic evaluation and management of patients with femoroacetabular impingement undergoing hip arthroscopy.

Purpose:

To explore the standard diagnostic evaluation practice of experts in the field of hip preservation surgery and combine their expertise through the Delphi method to form a standardized approach to the diagnostic evaluation of patients with nonarthritic hip pain.

Study Design:

Consensus statement.

Methods:

An expert panel made up of 18 orthopaedic surgeons with extensive experience in the treatment of nonarthritic hip disorders participated in this Delphi study. The Delphi panelists were presented with 4 clinical vignettes representing a spectrum of patients with nonarthritic hip pain. Three iterative survey rounds were presented to the panelists based on these clinical vignettes, and a 3-step classic Delphi method was used to establish consensus techniques in the diagnostic evaluation of nonarthritic hip pain.

Results:

Total (100%) participation was gained, with all 18 experts completing all 3 Delphi survey rounds. Consensus (≥75% support) was achieved for some, if not all, vignettes for each of the following diagnostic domains: historical features, physical examination, radiographic sequences, radiographic interpretation, cross-sectional imaging, and ancillary diagnostics.

Conclusion:

In this Delphi study, we identified standardized diagnostic treatment approaches as derived from expert opinion for patients with nonarthritic hip pathomorphologies.

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

PURPOSE

We measured the width of the acetabular labra in, and the clinical outcomes of, patients with borderline hip dysplasia (HD) who underwent arthroscopy.

METHODS

A total of 1436 patients who underwent hip arthroscopy to treat symptomatic, acetabular labral tears were enrolled. From this cohort, we extracted a borderline HD group (162 cases). Lateral labral widths were evaluated using preoperative magnetic resonance imaging scans. Clinical data including the modified Harris hip score (mHHS), non-arthritic hip score (NAHS), hip outcome score-activity of daily living (HOS-ADL) score, visual analog scale (VAS) pain score, and Tönnis grade were collected. In addition, patient satisfaction with arthroscopy outcomes was rated. All complications and reoperations were noted.

RESULTS

The mean follow-up time was 87.4 months. The lateral labral width was 7.64 mm in those with normal hips and 7.73 mm in borderline HD patients, respectively (p = 0.870). The Tönnis grade progressed mildly from 0.46 to 0.76 (p = 0.227). At the last follow-up, clinical outcome scores (mHHS, NAHS, and HOS-ADL scores) and the VAS score were improved (p < 0.001). The mean patient satisfaction was scored at 8.2. The reoperation rate was higher in those who underwent labral debridement (25.6%) than labral repair (4.1%).

CONCLUSIONS

The lateral labral width did not differ significantly between the borderline HD group and the nondysplastic control group. Arthroscopy relieved the symptoms of painful borderline HD and did not accelerate osteoarthritis. Therefore, if such patients do not respond to conservative treatment, hip arthroscopy can be considered for further treatment.

Hip Dysplasia

Acetabular dysplasia represents a structural pathomorphology associated with hip pain, instability, and osteoarthritis. The wide spectrum of dysplasia anatomically refers to a 3-dimensional volumetric- and surface area-based insufficiency in coverage and is classified based on the magnitude and location of undercoverage. Borderline dysplasia has been variably defined and leads to management challenges. In symptomatic dysplasia, treatment addresses coverage with periacetabular osteotomy. Concomitant simultaneous or staged hip arthroscopy has significant advantages to address intra-articular pathology. In nonarthritic individuals, there is evidence PAO alters the natural history of dysplasia and decreases the risk of hip arthritis and total hip arthroplasty.

Periacetabular Osteotomy as a Salvage Procedure: Early Outcomes in Patients Treated for Iatrogenic Hip Instability

BACKGROUND

A periacetabular osteotomy (PAO) can reduce pain and improve quality of life in patients with hip dysplasia. While its utility for patients without traditional radiographic parameters for hip dysplasia has not been previously established, the PAO may help treat patients with hip instability that does not improve following single or multiple hip arthroscopic procedures, or when such procedures lead to hip instability.

METHODS

A single-surgeon registry of patients at a single institution was queried to identify patients with a lateral center-edge angle (LCEA) of ≥24° and a Tönnis angle of <10° who underwent PAO because of hip pain and/or instability that failed treatment with hip arthroscopy. Descriptive summary statistics were reported on patient demographics, mean change in LCEA, and patient-reported outcome measures, including the modified Harris hip score (mHHS) and the International Hip Outcome Tool-33 (iHOT-33), at a minimum of 6 months of follow-up.

RESULTS

Among 25 patients (mean age, 27.3 ± 6.9 years; 100% women), the mean LCEA increased from 27.2° (range, 24° to 37°) preoperatively to 39.0° ± 5.1° postoperatively (net increase, 11.8° ± 4.5°). Overall, the mean improvement in the mHHS was 11.5 ± 16.9 (preoperative, 59.4 ± 11.6; postoperative, 70.9 ± 20.6) and the mean improvement in the iHOT-33 was 23.8 ± 23.6 (preoperative, 32.2 ± 17.2; postoperative, 56.0 ± 30.0). Eighteen patients (72%) achieved a minimal clinically important improvement in mHHS (mean improvement, 17.4 ± 12.9) and iHOT-33 (mean improvement, 32.4 ± 19.1) scores. In comparison with 7 patients who did not show improvement, the 18 patients who showed improvement had significantly greater mean baseline patient-reported outcome scores.

CONCLUSIONS

To our knowledge, these findings provide the first report on outcomes of PAO in patients with hip pain following arthroscopy who do not meet the traditional criteria for acetabular dysplasia. Early benefits in clinical outcomes suggest a novel surgical indication for PAO as a potential salvage option for selected patients; however, longer-term studies are needed.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Indications and Outcomes of Secondary Hip Procedures After Failed Hip Arthroscopy: A Systematic Review

PURPOSE

(1) To identify present indications for secondary procedures in patients with failed hip arthroscopy and (2) to assess patient-reported outcomes (PROs) of the secondary procedures, including revision arthroscopy, periacetabular osteotomy (PAO), and total hip arthroplasty (THA).

METHODS

Study groups included patients who had a secondary procedure after failed previous hip arthroscopy whereas the control groups were patients who had a primary procedure but did not require a secondary procedure. Indications and procedures at the time of the secondary operation were documented for each study. Average PROs were recorded, and standardized mean difference was calculated to estimate effect size.

RESULTS

Eighteen studies reporting on patients undergoing a secondary procedure after a previous hip arthroscopy were included. The 3 main secondary procedure groups were revision hip arthroscopy, secondary PAO, and secondary THA. Regarding the revision arthroscopy group, the most common indications were labral tears, cam deformity, and pincer deformity. In addition, the most common procedures were femoroplasty, acetabuloplasty, capsular release, and labral reconstruction. The most common indications for the secondary PAO and THA groups were dysplasia and osteoarthritis respectively. Five of the revision arthroscopy studies found that revision patients had worse outcomes than the primary arthroscopy group. One PAO study found that the previous arthroscopy group had slightly worse outcomes, and 2 studies found no differences in PROs. Two THA studies reported worse outcomes for the prior arthroscopy group, and 2 studies reported no differences in outcomes.

CONCLUSIONS

The most common indications for revision hip arthroscopy were labral tears and femoroacetabular impingement. Patients undergoing a revision hip arthroscopy demonstrated good postoperative outcomes but to an overall lesser extent than their primary counterparts. The secondary PAO and THA groups also had favorable PROs, but the studies were inconclusive in determining superior outcomes between the primary and secondary groups.

LEVEL OF EVIDENCE

IV, Systematic review of Level II-IV investigations.

Radiographic and clinical characteristics associated with a positive PART (Prone Apprehension Relocation Test): a new provocative exam to elicit hip instability

Hip instability due to mild dysplasia can be a diagnostic challenge. The physical exam is an important adjunct to radiographic evaluation for the clinical diagnosis of hip instability. Herein, we describe a new maneuver to replicate hip instability pain, called the PART (Prone Apprehension Relocation Test). We retrospectively identified patients in our institution’s hip preservation registry who presented for evaluation of hip pain. We divided patients into ‘positive’ or ‘negative’ PART and analyzed associated clinical and radiographic findings. Ninety patients (159 hips) were included, 83 female and 7 male, average age 27.3 ± 9.1 years. Thirty-four hips (21.4%) had a positive PART. There were no significant differences in hip range of motion, lateral center edge angle, or in acetabular depth. There was, however, a significant difference in acetabular version at 3 o’clock between the two test groups (18.5 ± 6.9° in negative, 21.2 ± 4.9° in positive, P = 0.045). There was no association between PART and previously described anterior apprehension testing. Historical methods of diagnosing hip dysplasia may not adequately identify patients with clinical hip instability. We describe a new provocative exam, the PART, which may be helpful in replicating hip instability symptoms in patients with anterior acetabular undercoverage. PART positive patients had significantly more acetabular anteversion at the 3 o’clock position, which is measured on computed tomography and is not visible on standard anteroposterior (AP) pelvis or false profile radiographs. We believe that the PART is a valuable supplement to clinical examination and radiographic measurements to identify patients with symptomatic hip instability.

Is Hip Arthroscopy an Adequate Therapy for the Borderline Dysplastic Hip? Correlation Between Radiologic Findings and Clinical Outcomes

Background

Recent studies have shown that assessment of the lateral center-edge angle (LCEA) between 18° and 25° is not sufficient to adequately classify mildly dysplastic hips and that further radiological features should be considered. However, no correlation between different morphologic features and clinical outcomes has been investigated so far.

Purpose

To analyze the clinical outcomes of patients with different subtypes of borderline dysplastic hips who underwent arthroscopic surgery.

Study Design

Cohort study; Level of evidence, 3.

Methods

We examined patients with an LCEA between 18° and 25° who underwent arthroscopic treatment for femoroacetabular impingement syndrome between January 2015 and December 2016. A hierarchical cluster analysis was performed to identify hip morphologic subtypes according to radiographic parameters, including the LCEA, femoro-epiphyseal acetabular roof (FEAR) index, anterior and posterior wall indices (AWI and PWI), Tönnis angle, alpha angle, and femoral neck-shaft angle. In addition, the International Hip Outcome Tool 12 (iHOT-12) and a visual analog scale (VAS) for pain were applied preoperatively and at follow-up, and the results were compared among the different clusters. Previously reported minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) values were used to determine clinically significant improvements.

Results

A total of 40 patients were identified. Of these, 36 patients were available for evaluation at a mean follow-up of 43.8 months. In total, 4 sex-independent clusters with different morphologic patterns of the hip were identified: cluster 1, unstable anterolateral deficiency (FEAR index >2°, AWI <0.35); cluster 2, stable anterolateral deficiency (FEAR index <2°, AWI <0.35); cluster 3, stable lateral deficiency (FEAR index >2°, normal AWI and PWI); and cluster 4, stable posterolateral deficiency (FEAR index <2°, PWI <0.85). At follow-up, clusters 1, 2, and 3 showed significantly improved iHOT-12 (P < .0001) and VAS pain (P < .0001) scores, and cluster 4 showed no significant improvements. The MCID of 15.2 points was achieved by all patients in clusters 2 and 3, by 63% of patients in cluster 1, and by 23% of patients in cluster 4. Clusters 2 and 3 differed significantly from clusters 1 and 4 (P = .02). A postoperative PASS score of 60 was achieved by all patients in cluster 3, by 86% of patients in cluster 2, by 63% of patients in cluster 1, and by 20% of patients in cluster 4. The differences between the groups were statistically significant (P = .01).

Conclusion

Arthroscopic surgery yielded good results in the treatment of stable borderline hip dysplasia with anterolateral and lateral deficiency. In contrast, borderline hip dysplasia with acetabular retroversion showed no improvements after arthroscopic therapy. This study underlines the need for an accurate analysis of all possible radiological signs to adequately classify borderline dysplastic hips.

Clinical and radiographic predictors of failed hip arthroscopy in the management of dysplasia: a systematic review and proposal for classification

PURPOSE

As indications for hip arthroscopy continue to expand, its efficacy in patients with more complex deformities of the hip, such as those with acetabular dysplasia, remains controversial. The purpose of this systematic review is to identify the predictors of failed hip arthroscopy in dysplastic hips and to propose a standardize prognostic sub-classification of dysplasia.

METHODS

This systematic review was performed in accordance with the (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) PRISMA guidelines. Three databases [EMBASE, PubMed, and Ovid (MEDLINE)] were searched using terms including "hip arthroscopy" and "dysplasia". Studies were screened and data extracted in duplicate. Study quality was assessed using the Methodological Index for Non-Randomized Studies criteria. Due to the non-uniform nature of study data, findings were presented in descriptive summary form.

RESULTS

Thirteen studies were included in this systematic review, comprising 712 dysplastic patients (773 hips) with mean age 34.2 years and 74.1% females. Most studies defined hip dysplasia by a lateral centre-edge angle (LCEA) of 20°-25° (borderline) or 15°-20° (moderate). Failure was defined as progression to revision arthroscopy, peri-acetabular osteotomy, or total hip arthroplasty. Overall, failure rate was 192/743 (25.8%) at an average of 28.1 months following index arthroscopy. Smaller LCEA, larger Tönnis angle, broken Shenton line, and decreased joint space (≤ 2 mm) were radiographic predictors of failure. Severe cartilage lesions to the femoral head or acetabulum were associated with failure in five studies. Labral debridement led to more failures than labral repair.

CONCLUSION

Overall, hip arthroscopy yielded good outcomes in mildly dysplastic hips without severe chondral damage. Hip arthroscopy is expected to result in a failed outcome in individuals with moderate-to-severe hip dysplasia (LCEA < 15°), severe cartilage lesions, larger Tönnis angle (> 20°), broken Shenton line, and decreased joint space (≤ 2 mm). Arthroscopic surgery may be more effective in individuals with borderline-to-mild (LCEA 15°-25°) acetabular dysplasia in the absence of severe cartilaginous lesions (7-year survival: 89.6%). A standardized prognostic classification of hip dysplasia based on the LCEA and Tönnis angle is proposed.

LEVEL OF EVIDENCE

Systematic review of non-randomized studies, Level IV.

Evaluation and Treatment of Borderline Dysplasia: Moving Beyond the Lateral Center Edge Angle

PURPOSE OF REVIEW

The purpose of this manuscript is to 1 define the features associated with borderline acetabular dysplasia and 2 review current status of diagnostic algorithms and treatment options for borderline dysplasia.

RECENT FINDINGS

Acetabular dysplasia is a common cause of hip pain secondary to insufficient coverage of the femoral head by the bony acetabulum. Historical classification of acetabular dysplasia has utilized the lateral center edge angle (LCEA); values above 25° are normal and below 20° are considered pathologic. Borderline dysplasia describes hips with LCEA between 20 and 25^o; treatment of these patients is controversial. While many studies utilize LCEA in classification of borderline dysplasia, isolated reliance on measurement of lateral femoral head coverage to define severity of undercoverage will continue to mislabel morphology. Thorough assessment of the characteristics of mild acetabular undercoverage is necessary for future studies, which will allow effective comparisons of results between hip arthroscopy and periacetabular osteotomy.

Functional and Clinical Outcomes of Patients Undergoing Revision Hip Arthroscopy With Borderline Hip Dysplasia at 2-Year Follow-up

PURPOSE

To compare outcomes of borderline hip dysplasia (BHD) patients undergoing revision hip arthroscopy with 1) patients with BHD undergoing primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and 2) patients without BHD undergoing revision hip arthroscopy for FAIS.

METHODS

A retrospective cohort study was performed to identify patients who underwent arthroscopy from January 2012 to January 2016 by a single fellowship-trained surgeon, including a 2-year follow-up. Patient demographics, comorbid medical conditions, and preoperative outcome scores were compared between patients with BHD (lateral center-edge angle 18° to 25°) who had revision hip arthroscopy to patients with BHD undergoing primary arthroscopy and patients without BHD (lateral center-edge angle >25°) undergoing revision arthroscopy. Cohorts were matched 2:1 by age and body mass index. Multivariate regressions were used to compare Hip Outcome Score, Activities of Daily Living subscale (HOS-ADL) and Sports subscale (HOS-SS) scores and modified Harris Hip Score (mHHS) between the cohorts at 2-year follow-up. Binomial regression analysis was used to determine predictors of achieving minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS).

RESULTS

There was no statistical difference in age and BMI between the BHD revision (29.1 ± 8.8 years; 25.5 ± 3.58 kg/m²), BHD nonrevision (28.9 ± 8.5 years; 24.6 ± 3.1 kg/m²), and non-BHD revision (29.15 ± 8.6 years; 25.01 ± 3.2 kg/m²) cohorts. There were no statistically significant differences in 2-year clinical outcomes between BHD revision patients and either BHD primary or non-BHD revision patient groups, but BHD revision patients were significantly less likely to achieve PASS for HOS-SS compared with BHD primary and non-BHD revision groups (P = .047 and P = .031, respectively).

CONCLUSION

Surgeons should exercise caution when indicating patients for revision hip arthroscopy with BHD. Although the current study lacks statistical power, the available data suggest that patients undergoing revision surgery with BHD may still experience clinical improvement but be less likely to achieve PASS metrics for several patient-reported outcomes at 2-year follow up.

LEVEL OF EVIDENCE

III, case-control study.

Hip Arthroscopic Surgery in Borderline Developmental Dysplastic Hips: A Systematic Review

BACKGROUND

It remains controversial whether hip arthroscopic surgery should be applied to patients with a borderline developmental dysplastic hip (BDDH).

PURPOSE

To review the outcomes of hip arthroscopic surgery for a BDDH and which factors influence these outcomes.

STUDY DESIGN

Systematic review.

METHODS

PubMed, Embase, and the Cochrane Library were searched through March 2018 for studies reporting the outcomes of primary hip arthroscopic surgery in patients with a BDDH. Inclusion in the review was based on the definition of a BDDH, patient-reported outcomes, and duration of follow-up. The primary outcome was the modified Harris Hip Score (mHHS). The failure rate, visual analog scale, satisfaction score, and patient-reported outcomes such as the Hip disability and Osteoarthritis Outcome Score were defined as secondary outcomes.

RESULTS

Nine studies with 425 patients who underwent hip arthroscopic surgery were included in this review. The mean follow-up times ranged from 25.4 to 28.8 months across the studies. A significant improvement was obtained in the mHHS, with a mean score of 61.8 preoperatively to 82.8 postoperatively; all other patient-reported outcomes also improved significantly, except the 12-Item Short Form Health Survey mental component summary. The overall failure rate was 14.1%, and the mean reoperation rate was 8.5%. The rate of conversion to total hip arthroplasty ranged from 4.4% to 26.0%, and the rate of conversion to periacetabular osteotomy was 4.0%. Combined defects such as cartilage damage, hip osteoarthritis, ligamentum teres tears, and femoroacetabular impingement could influence the outcomes after arthroscopic surgery in BDDHs.

CONCLUSION

Hip arthroscopic surgery was demonstrated to be a promising approach for BDDHs, but the outcomes could be influenced by multiple risk factors. A higher level of evidence is still needed to support current findings.

Periacetabular Osteotomy Improves Pain and Function in Patients With Lateral Center-edge Angle Between 18° and 25°, but Are These Hips Really Borderline Dysplastic?

BACKGROUND

The treatment of mild or borderline acetabular dysplasia is controversial with surgical options including both arthroscopic labral repair with capsular closure or plication and periacetabular osteotomy (PAO). The degree to which improvements in pain and function might be achieved using these approaches may be a function of acetabular morphology and the severity of the dysplasia, but detailed radiographic assessments of acetabular morphology in patients with a lateral center-edge angle (LCEA) of 18° to 25° who have undergone PAO have not, to our knowledge, been performed.

QUESTIONS/PURPOSES

(1) Do patients with an LCEA of 18° to 25° undergoing PAO have other radiographic features of dysplasia suggestive of abnormal femoral head coverage by the acetabulum? (2) What is the survivorship free from revision surgery, THA, or severe pain (modified Harris hip score [mHHS] < 70) and proportion of complications as defined by the modified Dindo-Clavien severity scale at minimum 2-year followup? (3) What are the functional patient-reported outcome measures in this cohort at minimum 2 years after surgery as assessed by the UCLA Activity Score, the mHHS, the Hip disability and Osteoarthritis Outcome Score (HOOS), and the SF-12 mental and physical domain scores?

METHODS

Between January 2010 and December 2014, a total of 91 patients with hip pain and LCEA of 18° to 25° underwent a hip preservation surgical procedure at our institution. Thirty-six (40%) of the 91 patients underwent hip arthroscopy, and 56 hips (60%) were treated by PAO. In general, patients were considered for hip arthroscopy when symptoms were predominantly associated with femoroacetabular impingement (that is, pain aggravated by sitting and hip flexion activities) and physical examination showed a positive anterior impingement test with negative signs of instability (negative anterior apprehension test). In general, patients were considered for PAO when symptoms suggested instability (that is, pain with upright activities, abductor fatigue now aggravated by sitting) and clinical examinations demonstrated a positive anterior apprehension test. Bilateral surgery was performed in six patients and only the first hip was included in the study. One patient was excluded because PAO was performed to address dysplasia caused by surgical excision of a proximal femoral tumor associated with multiple epiphyseal dysplasia during childhood yielding a total of 49 patients (49 hips). There were 46 of 49 females (94%), the mean age was 26.5 years (± 8), and the mean body mass index was 24 kg/m (± 4.5). Radiographic analysis of preoperative films included the LCEA, Tönnis acetabular roof angle, the anterior center-edge angle, the anterior and posterior wall indices, and the Femoral Epiphyseal Acetabular Roof index. Thirty-nine of the 49 patients (80%) were followed for a minimum 2-year followup (mean, 2.2 years; range, 2-4 years) and were included in the analysis of survivorship after PAO, complications, and functional outcomes. Kaplan-Meier modeling was used to calculate survivorship defined as free from revision surgery, THA, or severe pain (mHHS < 70) at minimum 2 years after surgery. Complications were graded according to the modified Dindo-Clavien severity. Patient-reported outcomes were collected preoperatively and at minimum 2 years after surgery and included the UCLA Activity Score, the mHHS, the HOOS, and the SF-12 mental and physical domain scores.

RESULTS

Forty-six of 49 hips (94%) had at least one other radiographic feature of dysplasia suggestive of abnormal femoral head coverage by the acetabulum. Seventy-three percent of the hips (36 of 49) had two or more radiographic features of hip dysplasia aside from a LCEA of 18° to 25°. The survivorship of PAO at minimum 2 years for the 39 of 49 (80%) patients available was 94% (95% confidence interval, 80%-90%). Three of 39 patients (8%) developed a complication. At a mean of 2.2 years of followup, there was improvement in level of activity (preoperative UCLA score 7 ± 2 versus postoperative UCLA score 6 ± 2; p = 0.02). Hip symptoms and function improved postoperatively, as reflected by a higher mean mHHS (86 ± 13 versus 64 ± 19; p < 0.001) and mean HOOS (386 ± 128 versus 261 ± 117; p < 0.001). Quality of life and overall health assessed by the physical domain of the SF-12 improved (47 ± 11 versus 39 ± 12; p < 0.001). However, with the numbers available, no improvement was observed for the mental domain of the SF-12 (52 ± 8 versus 51 ± 11; p = 0.881).

CONCLUSIONS

Hips with LCEA of 18° to 25° frequently have other radiographic features of dysplasia suggestive of abnormal femoral head coverage by the acetabulum. These hips may be inappropriately labeled as "borderline" or "mild" dysplasia on consideration of LCEA alone. A more comprehensive imaging analysis in these hips by the radiographic features of dysplasia included in this study is recommended to identify hips with abnormal coverage of the femoral head by the acetabulum and to plan treatment accordingly. Patients with LCEA of 18° to 25° showed improvement in hip pain and function after PAO with minimal complications and low proportions of persistent pain or reoperations at short-term followup. Future studies are recommended to investigate whether the benefits of symptomatic and functional improvement are sustained long term.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Psychometric Properties of Patient-Reported Outcome Measures for Periacetabular Osteotomy

BACKGROUND

Appropriate patient-reported outcome measures are paramount to determine the clinical relevance of change experienced by patients after a surgical procedure. The purpose of this study was to evaluate the psychometric properties of 3 patient-reported outcome measures (Hip disability and Osteoarthritis Outcome Score [HOOS], modified Harris hip score, and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) in a large population of patients treated with periacetabular osteotomy for symptomatic developmental dysplasia of the hip.

METHODS

Patients who underwent a periacetabular osteotomy for acetabular dysplasia between October 2011 and October 2016 completed multiple questionnaires preoperatively and at the 1-year follow-up. Internal consistency for subscores was evaluated with the Cronbach alpha. Validity was assessed against the Short Form-12. Interpretability included the calculation of the distribution of scores, floor and ceiling effects, and the minimal clinically important difference. Responsiveness was assessed by correlating the score changes with the Global Perceived Effect score.

RESULTS

Of 294 patients, 246 (84%) were female. The median age was 21 years (interquartile range, 17 to 29 years). All WOMAC and HOOS subscores demonstrated adequate internal consistency, and none of the modified Harris hip score components did. All scores except the WOMAC stiffness score exhibited adequate validity and interpretability, with no floor and ceiling effects over 15%. For the HOOS subscores, the minimal clinically important difference was 10.3 for pain, 10.2 for symptoms, 12.6 for sports and recreation, 11.2 for quality of life, and 10.8 for activities of daily living. The minimal clinically important difference for the modified Harris hip score was 7.4. For the WOMAC subscores, the minimal clinically important difference was 10.8 for pain, 12.9 for stiffness, 10.8 for physical, and 10.4 for total. All scores demonstrated adequate responsiveness.

CONCLUSIONS

The HOOS, WOMAC, and modified Harris hip score have adequate psychometric properties for use in patients undergoing periacetabular osteotomy, with minor shortcomings. Among the scores analyzed, the HOOS appears to be the most appropriate measure of patient-reported outcome in patients undergoing periacetabular osteotomy.

CLINICAL RELEVANCE

By establishing the psychometric properties of patient-reported outcome measures for periacetabular osteotomy, this study enables a more informed choice of measures for clinical practice and research. The estimated minimal clinically important difference values will facilitate understanding the importance of change in patient-reported outcomes after a surgical procedure in a clinical setting and sample size calculation for further studies.

Mild or Borderline Hip Dysplasia: Are We Characterizing Hips With a Lateral Center-Edge Angle Between 18° and 25° Appropriately?

BACKGROUND

Controversy surrounds the classification and treatment of hips with a lateral center-edge angle (LCEA) between 18° and 25°. It remains undetermined as to whether periacetabular osteotomy (PAO) or arthroscopic surgery is best used to treat this patient population.

HYPOTHESIS

Patients with hip pain and mild or borderline acetabular dysplasia defined by an LCEA between 18° and 25° have different features of acetabular and femoral morphology, as determined by other relevant radiographic measures assessing the anterior and posterior acetabular walls, anterior coverage of the femoral head by the acetabulum, and femoral head and neck junction sphericity.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A retrospective review of patients who had an LCEA between 18° and 25° undergoing hip preservation between January 2010 and December 2015 with either PAO or hip arthroscopic surgery was performed. Anteroposterior, Dunn lateral, and false profile radiographs were used to measure the LCEA, Tönnis angle, anterior center-edge angle (ACEA), anterior wall index (AWI) and posterior wall index (PWI), femoral epiphyseal acetabular roof (FEAR) index and posterior to anterior wall index, and alpha angle and femoral neck-shaft angle. An agglomerative hierarchical clustering analysis was then performed on the continuous radiographic variables to identify different subtypes of hip pathomorphology among the study cohort. There were sex-specific trends in hip morphology. Therefore, we proceeded to perform separate cluster analyses for each sex. Multivariate logistic regression was used to identify radiographic parameters for distinguishing between female patients who underwent hip arthroscopic surgery versus PAO.

RESULTS

Ninety-eight patients with hip pain and an LCEA between 18° and 25° underwent surgery in the study period, 77 (78%) were female, and 81 (82%) had complete radiographs for cluster analyses. The mean age was 22.6 years. Hip arthroscopic surgery was performed in 40 (41%) patients, and PAO was performed in 58 (59%) patients. The ACEA (45%), FEAR index (34%), and AWI (30%) were the most commonly abnormal radiographic parameters among all patients. In female patients, the ACEA (55%), FEAR index (42%), and AWI (34%) were the most commonly abnormal radiographic parameters. In male patients, the PWI (48%) was the most common radiographic abnormality. For female patients, 3 clusters representing different patterns of hip morphology were identified: acetabular deficiency with cam morphology, lateral acetabular deficiency, and anterolateral acetabular deficiency. For male patients, 3 clusters were also identified: posterolateral acetabular deficiency with global cam morphology, posterolateral acetabular deficiency with focal cam morphology, and lateral acetabular deficiency without cam morphology. The ACEA (odds ratio [OR], 47.7 [95% CI, 9.6-237.6]; P < .001) and AWI (OR, 3.9 [95% CI, 1.0-15.0]; P = .049) were identified as independent factors predicting which procedure was performed in female patients.

CONCLUSION

A comprehensive evaluation of radiographic parameters in patients with an LCEA between 18° and 25° identified sex-specific trends in hip morphology and showed a large proportion of dysplastic features among these patients. An isolated assessment of the LCEA is an oversimplistic approach that may jeopardize appropriate classification and may provide insufficient data to guide the treatment of hips with additional features of dysplasia and instability.

Is Hip Arthroscopy Effective in Patients With Combined Excessive Femoral Anteversion and Borderline Dysplasia? A Match-Controlled Study

BACKGROUND

Appropriate patient selection is critical when hip arthroscopy is considered in the setting of borderline dysplasia (BD). It is presumable that excessive femoral anteversion (EFA) and BD may contraindicate arthroscopy.

HYPOTHESIS

Patients with combined EFA and BD (EFABD) demonstrate significantly inferior short-term outcomes after arthroscopic labral preservation and capsular closure when compared with a similar control group with normal lateral coverage and femoral anteversion.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data were prospectively collected and retrospectively reviewed on patients undergoing hip arthroscopy between April 2010 and November 2014. The EFABD group's inclusion criteria were BD (lateral center-edge angle, 18°-25°), labral tear, capsular closure, and femoral version ≥20°, as well as preoperative modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score-Sports Specific Subscale, and visual analog scale. Exclusion criteria were workers' compensation, preoperative Tönnis grade >1, microfracture, abductor pathology, or previous ipsilateral hip surgery or conditions. Patients in the EFABD group were matched 1:2 to a similar control group with normal coverage and femoral anteversion by age at surgery ± 6 years, sex, body mass index ± 5, acetabular Outerbridge grade (0, 1 vs 2, 3, 4), and iliopsoas fractional lengthening.

RESULTS

Sixteen EFABD cases were eligible for inclusion, and 100% follow-up was obtained at ≥2 years postoperatively. Twelve EFABD cases were matched to 24 control cases. Mean femoral version was 22.4° in the EFABD group and 10.2° in the control group ( P = .01). Mean lateral center-edge angle was 22.1° in the EFABD group and 31.5° in the control group ( P < .0001). Acetabuloplasty was performed significantly more frequently in the control group ( P = .0006). No other significant differences were found regarding demographics, findings, procedures, or preoperative scores. At latest follow-up, the EFABD group demonstrated significantly lower mean modified Harris Hip Score (76.1 vs 85.9; P = .005), Nonarthritic Hip Score (74.8 vs 88.5; P < .0001), Hip Outcome Score-Sports Specific Subscale (58.3 vs 78.4; P = .02), and patient satisfaction (7.1 vs 8.3; P = .005). There were 4 secondary surgical procedures (33.3%) in the EFABD group and 1 (4.2%) in the control group ( P = .03). One patient in each group required arthroplasty.

CONCLUSION

Patients treated with arthroscopic labral preservation and capsular closure in the setting of EFABD demonstrated significant improvements from presurgery to latest follow-up. However, their results are significantly inferior when compared with a matched-controlled group. Consideration of periacetabular osteotomy or femoral osteotomy may be warranted in the setting of EFABD to achieve optimal benefit.

The management of the painful borderline dysplastic hip

Improved imaging and the evolution of surgical techniques have permitted a rapid growth in hip preservation surgery over the last few decades. The management of the painful borderline dysplastic hip however remains controversial. In this review, we will identify the pertinent issues and describe the patient assessment and treatment options. We will provide our own recommendations and also identify future areas for research.