Hip Arthroscopy Versus Conservative Treatment for Borderline Hip Dysplasia

Arthroscopic Hip Surgery Versus Individualized Conservative Treatment for Borderline Hip Dysplasia: A Multicenter Prospective Randomized Controlled Trial

The goal of this clinical trial is to compare the efficacy of hip arthroscopy versus individualized conservative treatment in patients with borderline developmental dysplasia of the hip (BDDH), defined by a lateral center-edge angle (LCEA) of 18-25°. The main question it aims to answer is: which treatment approach, surgical or conservative, provides superior pain relief, functional recovery, and quality of life improvement at 12 and 24 months post randomization? Participants will be randomly assigned (1:1) to either standardized hip arthroscopy, comprising capsular management, acetabular rim limited trimming, labral repair, and Cam deformity correction when indicated; or a 3-month individualized conservative protocol including patient education, nonsteroidal anti-inflammatory drugs (NSAIDs) for 2-4 weeks, chondroprotective supplementation for 8 weeks, and supervised progressive exercise training. All participants will undergo follow-up assessments at baseline, 12, and 24 months. The primary outcome is the modified Harris Hip Score (mHHS). Secondary outcomes include patient-reported outcome measures (VAS pain, iHOT-12, SF-12, and patient satisfaction), clinical assessments, and safety monitoring.

Study Overview

• Status: Not yet recruiting
• Conditions: Developmental Dysplasia of the Hip
• Intervention / Treatment: Procedure: Hip arthroscopy; Combination product: Individualized conservative treatment

Detailed Description

This multicenter, prospective, randomized controlled trial aims to compare the efficacy of hip arthroscopy versus individualized conservative treatment in patients with borderline developmental dysplasia of the hip (BDDH). BDDH, defined by a lateral center-edge angle (LCEA) of 18-25°, represents a distinct condition between normal hips and developmental dysplasia of the hip, and its optimal management remains controversial. A total of 248 eligible patients aged 18-42 years will be recruited from 23 qualified clinical centers across China and randomly assigned (1:1) to either hip arthroscopy surgery or individualized conservative therapy using minimization dynamic randomization stratified by age and LCEA. The conservative treatment protocol includes patient education, NSAIDs for 2-4 weeks, chondroprotective supplementation for 8 weeks, and supervised progressive exercise training for 3 months. The surgical group will undergo standardized hip arthroscopy with capsular management, acetabular rim limited trimming, labral repair, and Cam deformity correction when indicated. The primary outcome is the modified Harris Hip Score (mHHS) , with a minimal clinically important difference (MCID) of 9 points and patient-acceptable symptom state (PASS) threshold of 78 points. Secondary outcomes include patient-reported outcome measures (pain VAS, iHOT-12, SF-12, and patient satisfaction), clinical assessments (hip range of motion and impingement tests), and safety monitoring (adverse events recorded up to 24 months).

• Study Type: Interventional
• Enrollment (Estimated): 248
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age 18-42 years (studies have reported age ≥42 years as a risk factor for hip arthroscopy in BDDH: HR=11.6, 95% CI: 2.5-53.9), either sex;
2. Symptoms (anterior-lateral groin, lateral, or posterolateral hip pain or discomfort), physical examination findings (limp, clicking, locking, and limited range of motion), and imaging findings consistent with BDDH diagnosis (standing anteroposterior pelvic radiograph with Wiberg lateral center-edge angle [LCEA] 18-25°);
3. Surgeon's assessment that the patient with BDDH will benefit from hip arthroscopy or conservative treatment;
4. Full understanding of trial benefits and risks, willingness to participate in the intervention and complete follow-up, and signed informed consent.

Exclusion Criteria:

1. Standing anteroposterior pelvic radiograph showing Tönnis grade ≥2 and/or joint space <2 mm;
2. Standing anteroposterior pelvic radiograph showing FEAR index >5°;
3. Positive physical examination for joint instability: anterior apprehension test (HEER test), abduction-extension-external rotation test in lateral decubitus position (AB-HEER test), or prone external rotation test;
4. History of high-energy hip trauma, previous ipsilateral or contralateral hip surgery, avascular necrosis of the femoral head, slipped capital femoral epiphysis, Perthes disease, severe osteoporosis, tumor, acetabular stress fracture, or hypertrophic or inflammatory hip disease;
5. Concomitant consciousness disorder, psychiatric illness, or neuromuscular dysfunction affecting lower limb function;
6. Contraindications to hip arthroscopy (such as systemic or local infection).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Hip arthroscopy	Procedure: Hip arthroscopy; The surgical group will undergo standardized hip arthroscopy with capsular management, acetabular rim limited trimming, labral repair, and Cam deformity correction when indicated.
Active Comparator: Individualized conservative treatment	Combination product: Individualized conservative treatment; The conservative treatment protocol includes patient education, NSAIDs for 2-4 weeks, chondroprotective supplementation for 8 weeks, and supervised progressive exercise training for 3 months.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The modified Harris Hip Score	The primary outcome was the modified Harris Hip Score (mHHS), assessed at pre-intervention, and at 12 and 24 months post-randomization. It is a clinician-reported instrument designed to evaluate hip function, commonly used to assess functional recovery before and after conservative treatment or hip arthroscopy. The scale encompasses domains such as pain, function, joint range of motion, and deformity, providing a total score ranging from 0 to 100, with higher scores indicating better hip function (typically, 90-100 points represent excellent, 80-89 good, 70-79 fair, and <70 poor). The instrument has been validated in a relevant population for this trial, with a minimum clinically important difference of 9 points and a patient-acceptable symptom state threshold of 78 points.	Pre-intervention, and at 12 and 24 months post-randomization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Analogue Scale	The pain Visual Analogue Scale (VAS) score is a patient-reported instrument designed to quantify pain intensity. It uses a 100-mm line anchored by "no pain" and "worst imaginable pain," with a total score ranging from 0 to 100, where higher scores indicate more severe pain. This instrument has been validated in a relevant population for this trial.	Pre-intervention, and at 12 and 24 months post-randomization
International Hip Outcome Tool-12	The iHOT-12 (international Hip Outcome Tool-12) score is a patient-reported instrument designed to assess hip-related quality of life. Derived from the full iHOT-33 scale, this 12-item instrument covers domains such as symptoms, functional limitations, sports and recreational activities, and work-related concerns. It provides a total score ranging from 0 to 100, with higher scores indicating better hip function and quality of life.	Pre-intervention, and at 12 and 24 months post-randomization
General health: Short Form questionnaire-12 items	The 12-Item Short Form Survey (SF-12) is a validated and widely used health-related quality of life measure, commonly applied to assess hip conditions and treatment outcomes. The SF-12 generates the physical and mental component summary scores originally derived from the 36-Item Short Form Survey (SF-36) with considerable accuracy, while significantly reducing respondent burden. This 12-item scale comprises two dimensions: positive mental state and psychological distress symptoms. Scores from all items are summed to obtain a total score, with higher scores indicating more severe psychological distress.	Pre-intervention, and at 12 and 24 months post-randomization
Patient satisfaction	Patient satisfaction was measured using questions that our team had used in previous trials involving patients undergoing hip arthroscopy for BDDH. During follow-up, we assessed satisfaction in all participants by asking: "Overall, how satisfied are you with the treatment you received?" Responses were rated on a scale from 1 to 10, where 1 indicated dissatisfied and 10 indicated very satisfied.	12 and 24 months post-randomization
Clinical assessment	Clinical assessment performed at baseline and follow up visits consisted of range of passive hip movement, measured using a goniometer, and recording whether a participant experienced pain on each movement. Impingement tests determined whether a participant experienced pain on hip flexion, adduction, and internal rotation (FADIR) or flexion, abduction, and external rotation (FABER).	Pre-intervention, and at 12 and 24 months post-randomization
Adverse events	We recorded the number and type of adverse events up to 24 months. Any adverse events were recorded on the appropriate case report forms and returned to the clinical trial unit, where the chief investigator determined causality and expectedness. Serious adverse events deemed unexpected and related to the trial were reported to the Research Ethics Committee within 10 days.	post-randomization

Collaborators and Investigators

• Sponsor: ChunBao Li

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): December 12, 2028
• Study Completion (Estimated): June 30, 2029

Study Registration Dates

• First Submitted: March 16, 2026
• First Submitted That Met QC Criteria: March 20, 2026
• First Posted (Actual): March 25, 2026

Study Record Updates

• Last Update Posted (Actual): March 25, 2026
• Last Update Submitted That Met QC Criteria: March 20, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Borderline hip dysplasia; Arthroscopy; Conservative treatment
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases; Musculoskeletal Abnormalities; Congenital Abnormalities; Joint Dislocations; Hip Dislocation; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Developmental Dysplasia of the Hip
• Other Study ID Numbers: 2026KY001-HS001

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No