Chinese expert consensus on the diagnosis and treatment of borderline developmental dysplasia of the hip (2022 Edition)

A retrospective study of arthroscopic treatment for patients with bordline developmental dysplasia of the hip

PURPOSE

Hip arthroscopy is effective in treating bordline developmental dysplasia of the hip (BDDH), but there are only a few clinical reports in China, and its postoperative failure rate is still a problem that cannot be ignored. The aim of this study was to analyze the clinical effect of hip arthroscopy in BDDH treatment in China and to explore the risk factors influencing the efficacy of hip arthroscopy in BDDH treatment.

METHODS

All of 22 cases of BDDH treated with arthroscopy in our hospital from November March 2017 to February 2022 were analyzed retrospectively, including ten males and 12 females, with an average age of 34.7 ± 9.5 years (19-53 years). All patients underwent arthroscopic treatment with acetabular plasty, labral repair, femoral osteoplasty, and capsular plication. Visual Analogue Scale (VAS), modified Harris Hip Scores (mHHS), Hip Outcome Score-activities of Daily Living (HOS-ADL) and International Hip Outcome Tool-12 (iHOT-12) were measured before operation and at the follow-up, and statistical analysis was performed. The Minimum clinically significant difference (MCID) and Patient Acceptable Symptom State (PASS) were also obtained.

RESULTS

22 patients were followed up, and the follow-up time was ≥ one year, with an average of 21.4 ± 8.2 months. The VAS score decreased from 5.27 ± 1.58 points before surgery to 1.96 ± 0.92 points at the follow-up, and the difference was statistically significant (t = 9.05,P < 0.001). The mHHS score increased from 64.84 ± 13.58 points before surgery to 90.4 ± 10.11 points at the follow-up, and the difference was statistically significant (t=-7.07, P < 0.001). The HOS-ADL score increased from 68.92 ± 11.76 points before surgery to 88.91 ± 9.51 points at the follow-up, and the difference was statistically significant (t=-8.15,P < 0.001). The iHOT-12 score increased from 49.32 ± 12.01 points before surgery to 79.61 ± 15.89 points at the follow-up, and the difference was statistically significant (t=-7.66,P < 0.001). The MCID (mHHS) and MCID (HOS-ADL) were 81.8% and 77.3% respectively, and the PASS (mHHS) and PASS (HOS-ADL) were 86.4% and 72.7% respectively at the follow-up.

CONCLUSION

Hip arthroscopy can achieve good short-term outcomes in the treatment of BDDH.

LEVEL OF EVIDENCE

IV Therapeutic Study.

Editorial Commentary: Arthroscopy With Labral Preservation or Reconstruction Plus Capsular Closure Shows Excellent Outcome in Patients With Borderline Hip Dysplasia and is Less Invasive Than Periacetabular Osteotomy

Borderline developmental dysplasia of the hip (BDDH), or borderline hip dysplasia (BHD), traditionally characterized by a relatively low lateral center-edge angle (LCEA), presents a complex challenge in treatment due to its multifaceted etiology involving instability, femoroacetabular impingement (FAI), or a combination thereof. The optimal approach to managing adult BDDH remains a subject of significant debate. Periacetabular osteotomy (PAO) is considered the preferred treatment for addressing severe acetabular under-coverage, as it rectifies the underlying bony deficiency and promotes stability. However, the treatment of BDDH is less straightforward, particularly with the advancement of hip arthroscopy techniques, specifically labral preservation and capsular management. Given the minimally invasive and rapid postoperative rehabilitation advantage for arthroscopic procedures over open surgeries, numerous attempts have been undertaken in this context. Research has revealed favorable patient-reported outcomes (PROs), low failure rates, and a significant proportion of returning to sports (RTS) after arthroscopic management for patients with BDDH. Although we might in the right direction, Level I evidence studies are needed to comprehensively compare long-term PROs, failure rates, and rates of RTS between arthroscopy and PAO in the treatment of BDDH.

Lateral Center-edge Angle of 18° (Bone-Edge): Threshold for Hip Arthroscopy Treatment in Patients with Borderline Developmental Dysplasia of the Hip?

OBJECTIVE

Hip arthroscopy for the treatment of symptomatic borderline developmental dysplasia of the hip (BDDH) has been controversial. The purpose of this study was to retrospectively analyze minimum 2-year outcomes of BDDH after arthroscopic surgery and explore the criteria and thresholds of the lateral center-edge angle (LCEA) in arthroscopic surgery for BDDH.

METHODS

Data were retrospectively collected from patients aged 18-50 who underwent arthroscopic surgery for BDDH and had an LCEA 18-25° between September 2016 and June 2020. The consistency of interobserver and intraobserver measurements of bone-edge LCEA was analyzed. Patients were divided into two groups based on LCEA (18-20°and 20-25°) and the results of arthroscopy compared between groups. Patient-reported outcome (PRO) scores, consisting of the modified Harris hip score (mHHS), the visual analogue scale (VAS) and the international hip outcome tool-12 (IHOT-12), the minimal clinically important difference (MCID) and patient acceptable symptom status (PASS) were calculated.

RESULTS

In 52 patients with ≥2-year follow-up, female patients accounted for 71.2% and the mean age was 30.8 ± 8.4 years (range: 18 to 49 years). There was a high level of agreement when measuring the bone-edge LCEA definition of BDDH (Kappa = 0.921). Interobserver repeatability (ICC = 0.909, 95%CI: 0.847-0.947) and intraobserver repeatability (ICC = 0.944, 95%CI: 0.905-0.968) were excellent for bone-edge LCEA measurements. In addition to LCEA and Tönnis angle, there were no significant differences in α angle, neck stem angle, femoral anteversion angle, medial joint space, Tönnis grade of osteoarthritis, acetabular retroversion (8 sign), Cam deformity and anterior inferior iliac spine (AIIS) morphology between the two groups (p > 0.05). Intraoperative findings and procedures showed no statistical difference between groups (p > 0.05). The mean follow-up time was 44.4 ± 11.0 months (range: 25 to 64 months). Postoperative VAS, mHHS and IHOT-12 scores in the LCEA 18-20° group and the LCEA 20-25° group were significantly improved compared with those before surgery, and there was no statistically significant difference in the percentage of MCID and PASS (mHHS and iHOT-12) between the groups (p > 0.05).

CONCLUSION

Patients in the LCEA 18-20° group and the LCEA 20-25° group achieved favorable outcomes after arthroscopic surgery. LCEA 18° (bone-edge) should be the threshold for hip arthroscopic surgery in BDDH patients without obvious hip instability.