Survival of the dysplastic hip after periacetabular osteotomy: a meta-analysis

Background: Periacetabular osteotomy (PAO) has become a popular procedure for re-orientation of the acetabulum in patients with a developmental pathomorphology. Since its first description by Reinhold Ganz in 1988, many institutions worldwide have adopted the procedure for the treatment of developmental hip dysplasia (DDH) and have subsequently reported their results. The aim of this study was to provide a meta-analysis of the likelihood of long-term survival of a dysplastic hip after PAO. Methods: A systematic literature review was conducted using Medline, Cochrane and “Web of Science” databases to identify articles reporting survival estimates for PAO in patients with DDH. To be included in the analysis, studies had to include patient cohorts aged <40 years, with Osteoarthritis grade < Tönnis III and no form of neuromuscular dysplasia. Adjustment for cohort overlap was performed. Quality assessment included level of evidence (LOE) according to the oxford center for LOE criteria and the “Methodological index for non-randomized studies (MINORS)”. After data extraction, a random-effects meta-analytical model was applied to provide weighted mean estimates of survival at 5 years, 10 years, 15 years and 20 years. Results: Nine relevant articles included 2268 dysplastic hips that underwent PAO in 9 institutions. Of the included studies, 5 presented level III evidence and 4 presented level IV evidence. The MINORS score was 11 for 3 studies, 12 for 4 studies and 13 for 2 studies. The 5-year survival after PAO was 96.1% (95% CI, 94.9–97.3), the 10-year survival was 91.3% (95% CI, 87.7–94.8), 15-year survival 85.0% (95% CI, 78.9–91.1), 20-year survival 67.6% (95% CI, 53.9–81.3). Conclusions: The results provide a representative survival estimate of a dysplastic hip after PAO based on global evidence. This should provide clinicians and patients with an adequate reflection of prognostic expectations after this kind of surgery.

Prevalence of trochlear dysplasia in infants evaluated for developmental dysplasia of the hip

Purpose The purpose of this study was to define the incidence of trochlear dysplasia in an infant cohort being screened for developmental dysplasia of the hip (DDH). Methods Newborns screened for DDH that were evaluated with ultrasound for the presence of trochlear dysplasia were retrospectively reviewed. The sulcus angle and trochlear depth were measured. Based on previous work, trochlear dysplasia was defined as a sulcus angle of > 159°. Our newborn cohort was then analyzed to identify potential risk factors for trochlear dysplasia. Results A total of 383 knees in 196 infants were studied. In total, 52% were referred for breech intrauterine positioning and 21% were ultimately diagnosed with DDH and had treatment initiated with a Pavlik harness. Of the entire cohort, 8% of knees were deemed to have trochlear dysplasia. Breech patients were found to have a flatter sulcus angle than those that were not breech (149.5° (sd 7.2°) versus 147.9° (sd 7.5°); p = 0.028). Similarly, a shallower trochlear depth was identified in breech patients versus non-breech patients (1.6 mm (sd 0.4) versus 1.8 mm (sd 0.4); p = 0.019). Those with trochlear dysplasia (as defined by sulcus angle > 159°) did show a smaller alpha angle (i.e. more dysplastic hip) as compared with those without trochlear dysplasia (59.2° (sd 10.2°) versus 65.9° (sd 7.5°); p < 0.001). Hips with DDH were 2.4-times more likely to have knees with trochlear dysplasia (95% confidence interval 1.1 to 5.3). Conclusion Ultrasound screening of newborn knees reveals that trochlear dysplasia is relatively common in breech babies with DDH. Level of Evidence III

Dysplastic Hip Joint Configuration After Bernese Periacetabular Osteotomy

Background: Residual hip dysplasia is one of the factors contributing to early hip joint osteoarthritis. The main problems caused by residual dysplasia are pain and instability of the hip joint caused by the lack of sufficient bony covering of the femoral head. The aim of this work was to radiologically assess the configuration change of a dysplastic hip joint after surgical treatment using the Bernese periacetabular osteotomy procedure.Methods: We assessed the radiological parameters of patients with hip dysplasia treated by Bernense periacetabular osteotomy by performing a digital antero-posterior pelvis X-ray: central edge angle and femoral head coverage, medialization, distalization and ilio-ischial angle parameters. For normally distributed parameters, we used Student’s t-test; for parameters without a normal distribution, we used the Wilcoxon signed-rank test. Correlations were assessed according to a normal distribution using the Pearson and Spearman method.Results: For all parameters, we observed statistically significant differences in the measurements of dysplastic hip joints before and after the surgery. We also observed a statistically significant difference between the structure of dysplastic hip joints prior to the surgery and healthy hip joints from the control group based on all radiological parameters. The resulting medialization was 2.68 mm, distalization was 3.65 mm, and the ilio-ischial angle was changed by 2.62°. There was also an improvement in the femoral head bony covering: CEA by 17.61° and FHC by 16.46%.Conclusions: Based on all the radiological parameters, we presented the difference between healthy and dysplastic hip joints. Learning the parameter values that are used to describe dysplastic hip joints will allow us to improve the imaging of the condition and will also allow for better planning and proper qualification of patients for surgical treatment of hip joint dysplasia.Trial registration: Consent of the bioethics commission Medical Centre of Postgraduate Education 83/PB/2015 18.11.2015 Warsaw

Cup Positioning in True or False Acetabulum in Total Hip Arthroplasty: Which one is More Effective: A Randomized Clinical Trial on Patients with Crowe type 3 and 4 Dysplastic Hip

Background and objectives: Hip dysplasia is a common hip disease which could be diagnosed in different ages and Total hip arthroplasty (THA) is a common surgical procedure for dysplastic hip in adults. Cup placement in patients with false acetabulum formation could be performed in true or false acetabulum. The current study aimed at evaluating and comparing the effectiveness of these two procedures in patients with Crowe type 3 or 4 dysplastic hip underwent THA. Methods: In this randomized open label parallel group clinical trial 67 patients/71 hips with crowe type 3 or 4 dysplastic hip undergoing THA were assigned to Group 1: patients with cup placement in true acetabulum or group 2: patients with cup placement in false acetabulum. Severity of pain was assessed using visual analogue scale (VAS), range of motion (ROM), limb discrepancy, gait ability, need for repeated joint replacement and also Harris hip score. Data were collected and analyzed using SPSS software version 20.Results: 67 patients/71hips entered the current study with the mean age of 50.51± 9.94 years. Two study groups were comparable in terms of basic characteristics (P> 0.05). No significant differences were observed between two groups regarding mean values of VAS, ROM, limb discrepancy and Harris hip score (P> 0.05). Conclusion: Cup placements in true or false acetabulum showed comparable effectiveness on all studied main orthopedics outcomes which are clinically important. We recommend more clinical trial studies with larger sample size for confirming our study results.