Mild acetabular dysplasia and risk of osteoarthritis of the hip : a case-control study

Objective To determine whether mild variation in acetabular depth (AD) and shape is a risk factor for osteoarthritis (OA) of the hip. Methods The unaffected contralateral hip of patients with unilateral hip OA was compared with hips of asymptomatic controls without hip OA, derived from the Nottingham Genetics Osteoarthritis and Lifestyle case–control study. Standardised anteroposterior x-rays of the pelvis were used to measure centre edge (CE) angle and AD. Cut-off points for narrow CE angle and shallow AD were calculated from the control group (mean −1.96×SD). The relative risk of hip OA associated with each feature was estimated using OR and 95% CI and adjusted risks were calculated by logistic regression. Results In controls, both the CE angle and the AD were lower in the left hip than in the right hip. The CE angle related to age in both hips, and AD of the right hip was lower in men than in women. The contralateral unaffected hip in patients with unilateral hip OA had a decreased CE angle and AD compared with controls, irrespective of side. The lowest tertile of the CE angle in contralateral hips was associated with an eightfold risk of OA (aOR 8.06, 95% CI 4.87 to 13.35) and the lowest tertile of AD was associated with a 2.5-fold risk of OA (aOR 2.53, 95% CI 1.28 to 5.00). Significant increases in the risk of OA were also found as the CE angle and AD decreased

Prevalence and radiological definitions of acetabular dysplasia after the age of 2 years:a systematic review

Acetabular dysplasia is one of the most common causes of early hip osteoarthritis and hip replacement surgery. Recent literature suggests that acetabular dysplasia does not always originate at infancy, but can also develop later during childhood. This systematic review aims to appraise the literature on prevalence numbers of acetabular dysplasia in children after the age of 2 years. A systematic search was performed in several scientific databases. Publications were considered eligible for inclusion if they presented prevalence numbers on acetabular dysplasia in a general population of healthy children aged 2–18 years with description of the radiological examination. Quality assessment was done using the Newcastle-Ottawa score. Acetabular dysplasia was defined mild when: the center-edge angle of Wiberg (CEA-W) measured 15–20°, the CEA-W ranged between -1 to -2SD for age, or based on the acetabular index using thresholds from the Tönnis table. Severe dysplasia was defined by a CEA-W < 15°, <-2SD for age, or acetabular index according to Tönnis. Of the 1837 screened articles, four were included for review. Depending on radiological measurement, age and reference values used, prevalence numbers for mild acetabular dysplasia vary from 13.4 to 25.6% and for severe acetabular dysplasia from 2.2 to 10.9%. Limited literature is available on prevalence of acetabular dysplasia in children after the age of 2 years. Prevalence numbers suggest that acetabular dysplasia is not only a condition in infants but also highly prevalent later in childhood

Radiographic Prediction of the Results of Long-term Treatment with the Pavlik Harness for Developmental Dislocation of the Hip

In 1957, Pavlik introduced the Pavlik harness as a useful treatment for developmental dislocation of the hip (DDH), and subsequent studies have documented favorable outcomes among patients treated with this device. However, there are only a few articles reporting how early radiographic measurements can be used to determine the prognosis after treatment with the Pavlik harness. In this study, 217 hips from 192 patients whose DDH treatment with the Pavlik harness was initiated before they were 6 months old and whose follow-up lasted at least 14 years (rate, 63.8%) were analyzed using measurements from radiographs taken immediately before and after harness treatment, and at 1, 2, and 3 years of age. Severin's classification at the final follow-up was I or II in 71.9% and III or IV in 28.1% of the hips, respectively. Avascular necrosis of the femoral head (AVN) was seen in 10% of the hips. Stepwise multiple regression analysis was performed to retrospectively determine whether any radiographic factors were related to the final classification as Severin I/II or III/IV. Receiver opera-ting characteristic (ROC) curves were drawn for these factors, and a Wiberg OE angle (Point O was the middle point of the proximal metaphyseal border of the femur) of 2 degrees on the 3-year radiographs was found to be the most useful screening value for judging the acetabular development of DDH cases after treatment with a Pavlik harness, with a sensitivity of 71% a specificity of 93%, and a likelihood ratio of 10.1.</p

Patient-reported outcomes of periacetabular osteotomy from the prospective ANCHOR cohort study

BACKGROUND: Current literature describing the periacetabular osteotomy (PAO) is mostly limited to retrospective case series. Larger, prospective cohort studies are needed to provide better clinical evidence regarding this procedure. The goals of the current study were to (1) report minimum 2-year patient-reported outcomes (pain, hip function, activity, overall health, and quality of life), (2) investigate preoperative clinical and disease characteristics as predictors of clinical outcomes, and (3) report the rate of early failures and reoperations in patients undergoing contemporary PAO surgery. METHODS: A large, prospective, multicenter cohort of PAO procedures was established, and outcomes at a minimum of 2 years were analyzed. A total of 391 hips were included for analysis (79% of the patients were female, and the average patient age was 25.4 years). Patient-reported outcomes, conversion to total hip replacement, reoperations, and major complications were documented. Variables with a p value of ≤0.10 in the univariate linear regressions were included in the multivariate linear regression. The backward stepwise selection method was used to determine the final risk factors of clinical outcomes. RESULTS: Clinical outcome analysis demonstrated major clinically important improvements in pain, function, quality of life, overall health, and activity level. Increasing age and a body mass index status of overweight or obese were predictive of improved results for certain outcome metrics. Male sex and mild acetabular dysplasia were predictive of lesser improvements in certain outcome measures. Three (0.8%) of the hips underwent early conversion to total hip arthroplasty, 12 (3%) required reoperation, and 26 (7%) experienced a major complication. CONCLUSIONS: This large, prospective cohort study demonstrated the clinical success of contemporary PAO surgery for the treatment of symptomatic acetabular dysplasia. Patient and disease characteristics demonstrated predictive value that should be considered in surgical decision-making. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence

Prediction of time to prosthesis implantation as a function of joint anatomy in patients with developmental dysplasia of the hip

BACKGROUND: Developmental dysplasia of the hip (DDH) can lead to pain and premature secondary osteoarthritis at an early stage. Joint-preserving osteotomy is an established solution to this problem. In contrast, a conservative approach would result in pain persistence, ultimately raising the patients question for a possible date of expected prosthesis implantation. The aim of the study was to identify the relationship between the dysplastic hip anatomy and the time of prosthesis implantation in order to enable prognostic predictions in younger patients with symptomatic DDH. MATERIALS AND METHODS: Data from 129 hips who received THA due to secondary DDH osteoarthritis were evaluated. The preoperative hip anatomy was evaluated for AI and LCE angle. Multiple linear regression analyses were then used to correlate the influence of these parameters with the patient's age at the time of surgery. In addition, a graphical relationship was derived by the method of power least squares curve fitting with second-degree polynomials. RESULTS: The mean age for THA was 54.3 ± 11 years. The time of surgery correlated significantly with LCE (0.37) and AI (- 0.3) (p < 0.001). The mean age of patients with LCE angle ≤ 10° was 41.9 ± 14.0 years, for LCE 11-20° 52.7 ± 9.5 years, and for LCE 21-30° 57.0 ± 10.3 years. The following formula could then be determined for the calculation of the potential patient age at the time of THA as a function of LCE angle: age pTHA = 40.2 + 0.8 × LCE angle - 0.01 × (LCE angle)2. CONCLUSION: A significant correlation between the extent of dysplasia and the time of prosthesis implantation was identified. In particular, the LCE and the AI correlated strongly with the time of implantation. The more dysplastic the angles were, the sooner the THA was necessary. Using the calculations presented in this study, the probable age of prosthesis implantation can be prognosticated and included in a counseling session about treatment options for DD

Infant Hip Joint Diagnostic Support System Based on Clinical Manifestations in X-ray Images

Plain X-ray radiography is frequently used for the diagnosis of developmental dislocation of the hip (DDH). The aim of this study was to construct a diagnostic support system for DDH based on clinical findings obtained from the X-ray images of 154 female infants with confirmed diagnoses made by orthopedists. The data for these subjects were divided into 2 groups. The Min-Max method of nonlinear analysis was applied to the data from Group 1 to construct the diagnostic support system based on the measurement of 4 items in X-ray images:the outward displacement rate, upward displacement rate, OE angle, and alpha angle. This system was then applied to the data from Group 2, and the results were compared between the 2 groups to verify the reliability of the system. We obtained good results that matched the confirmed diagnoses of orthopedists with an accuracy of 85.9%

Prevalence of borderline acetabular dysplasia in symptomatic and asymptomatic populations: A systematic review and meta-analysis

Background: Patients with borderline acetabular dysplasia are a controversial patient population in hip preservation, as some have primarily impingement-based symptoms and others have instability-based symptoms. Borderline dysplasia is most commonly defined as a lateral center-edge angle (LCEA) of 20° to 25°. However, its prevalence has not been well established in the literature. Purpose: To (1) define the prevalence of borderline hip dysplasia in the general population as well as in populations presenting with hip pain using a systematic review and meta-analysis of the literature and (2) describe differences between male and female patients as well as differences in prevalence from that of classic acetabular dysplasia. Study Design: Systematic review; Level of evidence, 3. Methods: A systematic review of the literature was performed using search terms to capture borderline dysplasia, or studies reporting prevalence by LCEA. The search yielded 1932 results, of which 11 articles met inclusion criteria and were included in the final systematic review. Studies were grouped by patient cohort as (1) asymptomatic general population, (2) asymptomatic targeted population (eg, athletes in a specific sport), and (3) symptomatic hip pain population. The reporting of prevalence rates by subject or by hip was recorded. In a study, the rates of borderline dysplasia were compared with those of classic acetabular dysplasia (LCEA, \u3c20°). Results: The 11 studies included 19,648 hips (11,754 patients). In the asymptomatic general population, the pooled estimate of the prevalence of borderline dysplasia was 19.8% by subject and 23.3% by hip (range, 16.7%-46.0%). The targeted subpopulation group included 236 athletes with subgroups in ballet, football, hockey, volleyball, soccer, and track and field with prevalence ranging from 17.8% to 51.1%. The prevalence of borderline dysplasia in groups presenting with hip pain was 12.8% (range, 12.6%-16.0%). Borderline acetabular dysplasia was 3.5 times more common than classic acetabular dysplasia in the asymptomatic general population. Conclusion: This study demonstrated a prevalence of borderline dysplasia of 19.8% to 23.3% in the asymptomatic general population. Additionally, an estimated prevalence of 12.8% of hips in symptomatic patients highlights the common decision-making challenges in this population

Radiographic markers of hip dysplasia in young adults: predictive effect of factors in early life

Background and objectives Acetabular dysplasia in young adults occurs, despite screening for developmental hip dysplasia (DDH) in the neonatal period. We aimed to examine how early life factors predict radiographic measurements of acetabular dysplasia at 18–19 years of age. Methods From a previous randomized trial (n=12,014; 1988–90) evaluating the role of hip ultrasound in newborn screening of DDH, 4469 participants (2193 males) were invited to a follow-up 18 years later (2007–09), of which 2370 (53% attendance; 932 males) met. We examined associations between early life factors and four radiographic measurements for acetabular dysplasia at skeletal maturity. Hierarchical regressions, with addition of variables observed/ measured consecutively in time, were analyzed using mixed efects models considering hip as the unit in the analyses. The study is approved by the Regional Ethics Committee. Results In total, 2340 participants (921 boys), mean age 18.7 years, (SD 0.6) had hip radiographs performed at followup and were included. Early life factors signifcantly predicting radiographic acetabular dysplasia at age 18–19-years included female gender, breech, low acetabular inclination (alpha) angle and sonographic instability, abduction treatment, as well as the velocity of growth during childhood. A positive family history of DDH was not associated with acetabular dysplasia at skeletal maturity. Conclusion The acetabular inclination (alpha) angle as measured on ultrasound at birth turned out to be a signifcant predictor of dysplasia at 18–19 years of age. The discordant role of a positive family history in early versus adult hip dysplasia is intriguing, warranting further studies on the genetic mechanisms of DDH

Sex dimorphism of postural parameters of the human acetabulum

The aim of this investigation was to examine normal acetabular morphometry, its sex dimorphism and the acetabular dysplasia rate in Serbian adults. For each hip, the centre-edge angle of Wiberg, the acetabular angle of Sharp, acetabular depth and acetabular roof obliquity were measured. The center-edge angle of Wiberg correlated negatively with the acetabular angle of Sharp and acetabular roof obliquity, but positively correlated with acetabular depth. Our results suggest that the prevalence of acetabular dysplasia in the Serbian population is lower than in Western countries. We confirmed the existence of significant gender differences in acetabular morphology among the subjects of our study. These sex-related differences in acetabular morphology were the cause for more dysplastic female acetabula compared with male acetabula