Introduction. The purpose of this study was to demonstrate postoperative improvement and high satisfaction rates after a surgical approach that includes arthroscopic labral repair only, in patients with borderline dysplasia, without instability. Methods. Between September 2009 and December 2011, patients less than 50 years old who underwent hip arthroscopy for symptomatic intra-articular hip disorders, with a lateral center-edge (CE) angle between 20 and 25, were included in this study. Patients with Tönnis grade 2 or greater, hip joint space narrowing, severe hip dysplasia (CE〈20), hip joint instability and Legg-Calve-Perthes disease were excluded. Patient-reported outcome scores, including the modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Arthritis index (WOMAC), and visual analog scale (VAS) for pain were obtained in all patients preoperatively and at 1, 2, and 3 years postoperatively. Results. A total of 36 patients met the criteria to be included in the study. Of these, 32 (88.8%) patients were available for follow-up. There was a significant improvement in mHHS from 67.19±7.66 to 82.69±6.95 (P<0.001), and WOMAC score from 58.90±5.77 to 77.90±6.38 (P<0.001). There was a significant improvement in VAS scores from 5.8 to 2.9 (P<0.001). There was a significant improvement in range of motion, flexion from 108.44±7.77 to 115.31±6.08 (P<0.001) and external rotation from 29.06±5.74 to 33.13±4.88 (P<0.001). Conclusions. The current study demonstrates favorable results in borderline dysplasia hip without instability at minimum 3-year follow-up for an arthroscopic approach that includes labral repair. Labrum is the main key-stone structure, which should be preserved in borderline dysplasia hip for functional and pain improvement. Also the prognosis of treatment is probably forecasted more by the nature of stability and the intra-articular pathology rather than simply the presence or absence of radiographic finding of borderline dysplasia

Purpose. The purpose of this study was to demonstrate postoperative improvement and high satisfaction rates after a surgical approach that includes arthroscopic labral repair only, in patients with borderline dysplasia, without instability. Methods. Between September 2009 and December 2011, patients less than 50 years old who underwent hip arthroscopy for symptomatic intra-articular hip disorders, with a lateral center-edge (CE) angle between 20 and 25, were included in this study. Patients with Tönnis grade 2 or greater, hip joint space narrowing, severe hip dysplasia, hip joint instability and Legg-Calve-Perthes disease were excluded. Patient-reported outcome scores, including the modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Arthritis index (WOMAC), and visual analog scale (VAS) for pain were obtained in all patients preoperatively and at 1, 2, and 3 years postoperatively. Results. A total of 36 patients met the criteria to be included in the study. Of these, 32 (88.8%) patients were available for follow-up. There was a significant improvement in mHHS from 67.19 ± 7.66 to 82.69 ± 6.95 (P<0.05), WOMAC score from 58.90 ± 5.77 to 77.90 ± 6.38 (P<0.05), and VAS scores from 5.8 ± 0.88 to 2.9 ± 0.62 (P<0.05). There was a also improvement in range of motion, flexion from 108.44 ± 7.77 to 115.31 ± 6.08 (P<0.05) and external rotation from 29.06 ± 5.74 to 33.13 ± 4.88 (P<0.05). Conclusions. The current study demonstrates favorable results in borderline dysplasia hip without instability at minimum 3-year follow-up for an arthroscopic approach that includes labral repair. Labrum is the main key-stone structure, which should be preserved in borderline dysplasia hip for functional and pain improvement

The outcomes of hip arthroscopy in the treatment of dysplasia are variable. Historically, arthroscopic treatment of severe dysplasia (lateral center-edge angle [LCEA] < 18°) resulted in poor outcomes and iatrogenic instability. However, in milder forms of dysplasia, favorable outcomes have been reported. The purpose of this study was to compare outcomes following hip arthroscopy for femorocetabular impingement (FAI) in borderline dysplastic (BD) patients compared with a control group of non-dysplastic patients.

Between March 2009 and July 2012, a BD group (LCEA 18°–25°) of 46 patients (55 hips) was identified. An age and sex-matched control group of 131 patients (152 hips) was also identified (LCEA 25°–40°). Patient-reported outcome scores, including the Modified Harris Hip Score (mHHS), the Hip Outcome Score-Activity of Daily Living (HOS-ADL), the Sport-specific Subscale (HOS-SSS), and the International Hip Outcome Tool (iHOT-33), were collected pre-operatively, at 1, and 2 years.

The mean LCEA was 22.4 ± 2.0° (range, 18.4°–24.9°) in the BD group and 31.0 ± 3.1° (range, 25.4°–38.7°) in the control group (p<0.001). The mean preoperative alpha angle was 66.3 ± 9.9° in the BD group and 61.7 ± 13.0° in the control group (p=0.151). Cam decompression was performed in 98.2% and 99.3% of cases in the BD and control groups. Labral repair was performed in 69.1% and 75.3% of the BD and control groups respectively, with 100% of patients having a complete capsular closure performed in both groups. At a mean follow-up of 31.3 ± 7.6 months (range, 23.1–67.3) in unrevised patients and 21.6 ± 13.3 months (range 4.7–40.6) in revised patients, there was significant improvement (p<0.001) in all patient reported outcome scores in both groups. Multiple regression analysis did not identify any significant differences between groups. Importantly, female sex did not appear to be a predictor for inferior outcomes. Two patients (4.3%) in the BD group and six patients (4.6%) in the control group required revision arthroscopy during the study period.

Favorable outcomes can be expected following the treatment of impingement in borderline dysplastics when labral refixation and capsular closure are performed, with comparable outcomes to non-dysplastic patients. Further follow-up in larger cohorts is necessary to prove the durability and safety of hip arthroscopy in this challenging group and to further explore potential gender-related differences in outcome.

Hip dysplasia has traditionally been classified based on the lateral centre edge angle (LCEA). A recent meta-analysis demonstrated no definite consensus and a significant heterogeneity in LCEA values used in various studies to define hip dysplasia and borderline dysplasia. To overcome the shortcomings of classifying hip dysplasia based on just LCEA, a comprehensive classification for adult acetabular dysplasia (CCAD) was proposed to classify symptomatic hips into three discrete prototypical patterns of hip instability, lateral/global, anterior, or posterior. The purpose of this study was to assess the reliability of this recently published CCAD. One thirty four consecutive hips that underwent a PAO were categorized using a validated software (Hip2Norm) into four categories of normal, lateral/global, anterior or psosterior. Based on the prevalence of individual dysplasia and using KappaSize R package version 1.1, seventy four cases were necessary for reliability analysis: 44 dysplastic and 30 normal hips were randomly selected. Six blinded fellowship trained raters were then provided with the classification system and they looked at the x-rays (74 images) at two separate time points (minimum two weeks apart) to classify the hips using standard PACS measurements. Thereafter, a consensus meeting was held where a simplified flow diagram was devised before a third reading by four raters using a separate set of 74 radiographs took place. Intra-rater results per surgeon between Time 1 and Time 2 showed substantial to almost perfect agreement amongst the raters. With respect to inter-rater reliability, at time 1 and time 2, there was substantial agreement overall between all surgeons (kappa of 0.619 for time 1 and 0,623 for time 2). Posterior and anterior rating categories had moderate and fair agreement at time 1 and time 2, respectively. At time 3, overall reliability (kappa of 0.687) and posterior and anterior rating improved from Time 1 and Time 2. The comprehensive classification system provides a reliable way to identify three categories of acetabular dysplasia that are well-aligned with surgical management. The term borderline dysplasia should no longer be used