Acetabular Head Index Research Articles

Correlation of postoperative magnetic resonance image measurements with persisting acetabular dysplasia in open reduction of developmental hip dysplasia.

Objectives The aim of this study was to evaluate correlation of post-reduction magnetic resonance imaging (MRI)-based parameters with residual acetabular dysplasia in developmental dysplasia of the hip (DDH) patients who underwent open reduction.Patients and methods A total of 62 hips of 54 children (5 males, 57 females; mean age: 8.5±3.5 months; range, 0 to 24 months) with a diagnosis of DDH who underwent open reduction between January 2012 and January 2017 were retrospectively analyzed. The acetabular head index (AHI), head coverage index (HCI), sphericity, bony acetabular index (BAI), cartilage acetabular index (CAI), anterior acetabular index (AAI), posterior acetabular index (PAI), abduction angle (AA), and acetabular medial wall thickness were measured by MRI. The correlation between MRI measurements and residual acetabular dysplasia was evaluated.Results The mean follow-up was 23.7±10.1 (range, 12 to 56) months. The mean age at the final examination was 47.6±10.4 months. The age at the time of operation (r=0.250, p=0.049), medial wall thickness (r=0.304, p=0.016), AAI (r=0.729, p<0.001), PAI (r=0.590, p<0.001), and early postoperative AI (r=0.900, p<0.001) at the third postoperative month were positively correlated with the last follow-up AI. The AHI (r=-0.512, p<0.001), sphericity (r=-0,661, p<0.001), and HCI (r=-0.554, p <0.001) were negatively correlated with the last follow-up AI.Conclusion Post-reduction MRI parameters can be used to evaluate correlation with persistent acetabular dysplasia in DDH patients.

Prevalence of radiographic hip dysplasia in japanese population-based study

Objectives The purpose of this study was to measure the indices of radiographic developmental dysplasia of the hip (DDH) in a cross-sectional study of an elderly Japanese population. Methods Hip radiographs of 427 informed, voluntary Japanese community-dwelling individuals (279 female and 148 male) aged 50 to 96 years-old were obtained from Miyagawa village in Japan through a health screening. The hip radiographs were measured by a custom-written, semi-automated MATLAB program. The center edge (CE) angle, acetabular roof obliquity (ARO), acetabular head index (AHI), and minimum joint space width (mJSW) were measured. We examined the associations between gender, side-of-hip, and age group on radiographic DDH and hip osteoarthritis (OA). Results The mean CE angle was 31.0°. The mean ARO was 5.8°. The mean AHI was 88.2%. The mean mJSW was 4.0 mm. Of the total population, 29.9% had DDH and 4.0% had hip OA. Of those who had hip OA, 41.2% were secondary OA, and 58.8% were primary OA. The relationship between DDH and OA was not significant. Conclusion DDH is unlikely to be an important cause of hip OA in the present population-based study.

Magnetic resonance imaging follow-up can screen for soft tissue changes and evaluate the short-term prognosis of patients with developmental dysplasia of the hip after closed reduction

BackgroundMagnetic resonance imaging (MRI) can show the architecture of the hip joint clearly and has been increasingly used in developmental dysplasia of the hip (DDH) confirmation and follow-up. In this study, MRI was used to observe changes in the hip joints before and after closed reduction (CR) and to explore risk factors of residual acetabular dysplasia (RAD).MethodsThis is a prospective analysis of unilateral DDH patients with CR and spica cast in our hospital from October 2012 to July 2018. MRI and pelvic plain radiography were performed before and after CR. The labro-chondral complex (LCC) of the hip was divided into four types on MRI images. The variation in the thickening rate of the ligamentum teres, transverse ligaments, and pulvinar during MRI follow-up was analyzed, and the difference in cartilaginous acetabular head index was evaluated. The “complete relocation” rate of the femoral head was analyzed when the cast was changed for the last time, and the necrotic rate of the femoral head was evaluated after 18 months or more after CR. Lastly, the risk factors of RAD were analyzed.ResultsA total of 63 patients with DDH and CR were included. The LCC was everted before CR and inverted after CR, and the ligamentum teres, transverse ligaments, and pulvinar were hypertrophic before and after CR, and then gradually returned to normal shape. The cartilaginous acetabular head index gradually increased to normal values. Complete relocation was observed in 58.7% of femoral heads, while 8.6% had necrosis. The abnormalities in LCC was related to RAD (OR: 4.35, P = 0.03), and the rate of type 3 LCC in the RAD group was higher. However, the IHDI classification (P = 0.09); the “complete relocation” of femoral heads (P = 0.61); and hypertrophy of the ligamentum teres (P = 1.00), transverse ligaments (P = 1.00), and pulvinar (P = 1.00) were not related to RAD.ConclusionsIn this study, MRI can observe the variations of the abnormal soft tissue structures of the diseased hips after CR and spica casting, and can evaluate which hips will have RAD after CR. Therefore, we can utilize MRI in DDH patients appropriately.

Preoperative Rather Than Postoperative Intra-Articular Cartilage Degeneration Affects Long-Term Survivorship of Periacetabular Osteotomy

To determine whether intra-articular lesions changed in short-term follow-up after periacetabular osteotomy (PAO) and whether the intra-articular lesion changes impacted the long-term survivorship of PAO. We reviewed patients with hip dysplasia who underwent PAO with arthroscopic observation between 1990 and 2001. Patients who underwent second-look arthroscopy were included. The correlations between the intra-articular lesion changes and the long-term outcome of PAO were analyzed for patients with >10 years of follow-up. The possible risk factors included demographic factors (age, sex, and body mass index), radiographic factors (Tönnis grade, lateral center-edge angle, Tönnis angle, acetabular head index, crossover sign, posterior wall sign, and joint congruity), and arthroscopic findings (full-thickness lesions at the time of PAO and lesions changes at the time of second-look arthroscopy). A total of 64 patients (72 hips) were studied. Second-look arthroscopy was performed at a median of 1.4 years after PAO. Intra-articular lesions were observed in 93% in the acetabulum, 81% in the femoral head, and 97% in the labrum, respectively. These lesions unchanged in 74% in the acetabulum, 76% in the femoral head, and 79% in the labrum, respectively. Cartilage repair was observed in the acetabulum and the femoral head in 24% and 17% of hips, respectively. Labral repair occurred in 10%. Intra-articular lesion changes were not a predictor of failure. Multivariate analysis identified International Cartilage Repair Society grade 4 lesion in the femoral head as an independent risk factor for failure. Our results suggest that PAO prevents further deterioration in mild cartilage lesions and results in cartilage repair in some cases with advanced cartilage degenerations in the short term. However, these postoperative changes were not associated with long-term survivorship. Thus, appropriate surgical indications based on the preoperative intra-articular cartilage degeneration is paramount to achieving long-term success in PAO. Level IV, therapeutic study.

Clinico-radiological correlation during the course and healing of Legg-Calve-Perthes’ disease treated by a non-intensive conservative method

Introduction. The purpose of this study is to signify any clinical and radiological correlation, if present, in patients of Legg-Calve-Perthes’ disease (LCPD) who underwent an ambulatory conservative method of containment and their final outcome. Material and methods. Retrospective study over an 8-year period including patients of LCPD who were treated by an ambulatory conservative method showing signs of healing in the last radiological assessment was done. Clinically, gait, limb length discrepancy, range of motion of the hip, and Harris hip score were noted. The radiological parameters assessed in this study were epiphyseal index, epiphyseal quotient, acetabular head index, and epiphyseal extrusion index. Stulberg criteria was used to assess final outcome. Results. A total of 24 patients (17 males, 7 females) with a mean age of 7.9±3 years (5–9 years) who had a clinic-radiological diagnosis of LCPD were included in the study. There was a significant improvement of range of motion of the hip joint along with Harris hip score (t(18)= -16.77, p&lt;0.001) but no significant changes in the radiological parameters during the course of the disease. There was no correlation between radiological parameters and Harris hip score. 79.1% (19/24) had a good outcome at final follow up. Conclusion. The function and clinical outcome during the course and healing of LCPD does not correlate with the radiographic changes and ambulatory conservative management leads to satisfactory improvement in functional activity. Age at onset and lateral pillar classification are important factors influencing final outcome in LCPD.

A longitudinal study for the prediction of the mature acetabular morphology using childhood magnetic resonance imaging

BackgroundAlthough acetabular dysplasia is a common etiology of osteoarthritis of the hip regardless of the history of developmental dysplasia of the hip (DDH), whether or not corrective surgeries are beneficial for the childhood asymptomatic acetabular dysplasia remains controversial due to a lack of evidence. We conducted a longitudinal study to compare the cartilaginous morphology on childhood magnetic resonance imaging (MRI) and the mature hip morphology of the same patient and to assess the predictive indicators for future acetabular dysplasia. MethodsA total of 92 unaffected hips (47 unilateral DDH and 45 unilateral Legg-Calvé-Perthes disease) were reviewed for X-ray and MRI findings on childhood (mean age: 6.0 years) and X-ray findings from a skeletally mature age with a mean follow-up period of 15.1 years. The following parameters were measured and compared: the immature-acetabular index (AI) and center edge angle (CE) on immature X-ray; the cartilage- and bone- AI, CE, Sharp and acetabular head index (AHI) on childhood MRI; and the mature-acetabular roof obliquity (ARO), CE, Sharp and AHI on skeletally mature X-ray. The prognostic factors on childhood MRI for acetabular dysplasia, defined by a CE of <20° on skeletally mature X-ray were also assessed. ResultsPositive correlations were shown between the cartilage-AI and mature-ARO (7.6°/6.3°; r = 0.44), the cartilage-CE and mature-CE (27.8°/28.0°; r = 0.62), the cartilage-Sharp and mature-Sharp (44.4°/41.8°; r = 0.52) and the cartilage-AHI and mature-AHI (78.7%/80.3%; r = 0.46). A multivariate analysis indicated cartilage-CE to be an independent predictor for acetabular dysplasia with a cut-off value of 22°. Children with a cartilage-CE <22° developed more frequently acetabular dysplasia compared to the others (52.4% vs. 1.4%). ConclusionsChildhood MRI findings are useful for the prediction of acetabular dysplasia without a DDH history. Children with a cartilage-CE ≥23° are likely to achieve a non-dysplastic hip without the need for surgical intervention.

Acetabular reaming and sartorius muscle pedicle iliac bone grafting in the treatment of developmental dysplasia of the hip in older children: a retrospective study of 15 patients with more than two years follow-up.

PurposeDespite the early diagnosis and treatment of developmental dysplasia of the hip (DDH), some older children still need open reduction. It is usually difficult to get a satisfactory reduction particularly in patients with acetabular defect. The purpose of this study was to evaluate the short-term outcomes of acetabulum reaming and sartorius muscle pedicle iliac bone grafting in the treatment of older children with DDH and acetabular defect.MethodsThe records of 15 patients with DDH (mean age 113.9 months (sd 29); 17 hips) who were treated with the reported technique between February 2015 and January 2017 were retrospectively reviewed. All patients acquired regular clinical and radiographic follow-ups, and alterations in the acetabular index, centre-edge angle and acetabular head index were measured. Joint function and radiographic results were evaluated with McKay and Severin modified criteria, respectively.ResultsA total of 15 patients were followed up for mean 32.4 months (sd 6.9). The percentages of excellent and good conditions were 94.1% (16/17) according to the Severin modified criteria and 88.2% (15/17) according to the McKay modified criteria. Avascular necrosis of the femoral head and redislocation only occurred in one hip. No cases of ankylosis or bone graft absorption occurred during the follow-up.ConclusionReaming the acetabulum and sartorius muscle pedicle iliac bone grafting for repairing the acetabular defect can recover the arcuate structure by increasing the volume of the acetabulum, which is beneficial for achieving a concentric reduction. The short-term outcome was satisfactory, while the long-term results need to be further observed.Level of EvidenceIV – retrospective study

Long-Term Results of Periacetabular Rotational Osteotomy Concomitantly With Arthroscopy in Adult Acetabular Dysplasia

BackgroundAlthough the long-term results of periacetabular osteotomy in acetabular dysplasia have been well documented, there is paucity in reports on the long-term outcomes of periacetabular osteotomy with simultaneous hip arthroscopy. This study aimed to assess the cumulative 10-year outcomes of periacetabular rotational osteotomy with concomitant hip arthroscopy. MethodsThrough an arthroscopic procedure, the status of the labrum was assessed, and torn labrum was debrided. Evaluations on survival from conversion to total hip arthroplasty and success in radiographic and clinical long-term results were completed in 39 hips (36 patients). Acetabular parameters (center-edge angle, Sharp angle, acetabular-head index, and head lateralization index), Tönnis grades on radiograph, Harris Hip Score, and range of motion of the hip were evaluated. Survivorship analyses were evaluated with the Kaplan-Meier method. ResultsThirty-eight hips (97.4%, 95% confidence interval 0.832-0.996) were preserved for 12.8 ± 1.7 years on average, and only 1 hip was converted to total hip arthroplasty at 7.8 years. All the acetabular parameters were improved (P < .001). Twenty-eight hips (71.8%) showed unchanged or improved Tönnis grades at the latest follow-up. The average Harris Hip Score was significantly better than the preoperative value (P < .001), and range of motion was not significantly different until the latest follow-up. ConclusionSufficient acetabular reorientation, such as periacetabular rotational osteotomy, with concomitant arthroscopic debridement showed successful long-term outcomes for acetabular dysplasia in adults.

Investigation of the priority among the roentgenogram measurements in acetabular dysplasia.

There are many radiographic parameters to evaluate developmental dysplasia of the hip joint (DDH); however, the priority between the parameters is unclear. We evaluated the priority of radiographic parameters in DDH. We retrospectively reviewed the radiographs of 82 consecutive patients aged above 85 years without hip osteoarthritis (OA; no osteoarthritis (NO) group), and 28 patients with early stage hip OA were set as the control group (OA group). We used the linear discriminant analysis (LDA) to consider the priority of the following parameters: acetabular roof obliquity (ARO), center-edge (CE) angle, Sharp angle, acetabular head index (AHI), and acetabular depth ratio (ADR). The LDA of five different parameters revealed that the NO and OA groups could be almost distinguished with 83.6% accuracy (p < 0.0001, Wilks' lambda test). The standardized scoring coefficients were as follows: ARO, -0.23; CE, -0.43; Sharp, -0.29; AHI, 0.97; and ADR, 0.11. The AHI was particularly noticeable in the NO group. Dissociation of the AHI in the OA group was significantly higher than that of the other parameters in the OA group compared to the parameters in the NO group. A small AHI may be a risk parameter for hip OA due to DDH.

Radiological results of Shelf acetabuloplasty in adolescent hip dysplasia with aspherical femoral head: how to get an ideal placement of the Shelf graft.

Shelf acetabuloplasty continues to be effective in the prevention or delay of osteoarthritis in adolescent dysplastic hips. We aimed to evaluate the efficacy and to determine the correct level of the bone graft objectively. We retrospectively analyzed 16 hips underwent Shelf acetabuloplasty originated by Spitzy. The mean age at surgery was 15.3 years old with the mean caput index at 39.7%. The average follow-up was 11 years. The radiological evaluation was based on acetabular-head index (AHI) at preoperative and latest radiographs, acetabular-Shelf distance (ASD) and Shelf-head ratio at immediate postoperative and latest radiographs. The cutoff value for the ideal ASD was determined by receiver operating characteristic (ROC) and the Pearson correlation test used in statistical analysis to assess the relationship between ASD and Shelf graft resorption. Clinical evaluation was performed using Harris Hip Score (HHS) at the latest follow-up. The AHI was improved in all cases, from mean 56.9 to 91.0% (P < 0.001). The mean of ASD was 7 mm. In nine of the 16 cases, the Shelf graft was well united at the same level of the existing acetabulum with good continuity. The ROC curve showed the cutoff value for the ideal ASD was 6 mm. The Pearson correlation test also showed a positive relationship between ASD and Shelf graft resorption (P = 0.001). The average of HHS scores was 98.1 points. Both radiological and clinical results were acceptable. The ideal placement that keeps the shelf sufficient to bear the mechanical stress without bone resorption over time was at the level of 6 mm from the joint space. Level III - therapeutic study.

Long-term outcomes of the hip shelf arthroplasty in adolescents and adults with residual hip dysplasia: a systematic review

Background and purpose — The shelf arthroplasty was the regular treatment for residual hip dysplasia before it was substituted by the peri-acetabular osteotomy. Yet, evidence regarding the survival of shelf arthroplasty surgery has never been systematically documented. Hence, we investigated the survival time of the shelf procedure until revision to THA in patients with primary hip dysplasia. Factors that influenced survival and complications were also examined, along with the accuracy of correcting radiographic parameters to characterize dysplasia.Material and methods — The inclusion criteria were studies of human adolescents and adults (> 16 years) with primary or congenital hip dysplasia who were treated with a shelf arthroplasty procedure. Data were extracted concerning patient characteristics, survival time, complications, operative techniques, and accuracy of correcting radiographic parameters.Results — Our inclusion criteria were applicable to 9 studies. The average postoperative Center-Edge Angle and Acetabular Head Index were mostly within target range, but large variations were common. Kaplan–Meier curves (endpoint: conversion to THA) varied between 37% at 20 years’ follow-up and 72% at 35 years’ follow-up. Clinical failures were commonly associated with pain and radiographic osteoarthritis. Only minor complications were reported with incidences between 17% and 32%.Interpretation — The shelf arthroplasty is capable of restoring normal radiographic hip parameters and is not associated with major complications. When carefully selected on minimal osteoarthritic changes, hip dysplasia patients with a closed triradiate cartilage may benefit from the shelf procedure with satisfactory survival rates. The importance of the shelf arthroplasty in relation to peri-acetabular osteotomies needs to be further (re)explored.

Closed Reduction as Therapeutic Gold Standard for Treatment of Congenital Hip Dislocation

Congenital hip dislocation (luxation) has an incidence of 0.4 - 0.7% and is regarded as a prearthrotic deformity. Thus, if not being diagnosed and treated at a very early age, extensive surgical measures are inevitable in childhood and early adulthood. In the time between 01/2013 and 02/2019 we performed 28 600 hips sonographies in babies as part of general screening measures at U2 or U3. There were 71 instable, dysplastic or dislocated hips diagnosed that were treated by arthrographic, closed reduction. After a hip spica cast was applied, reposition was controlled by MRI, estimating the acetabular head index (ACI), the head coverage index (HCI) as well as the femoral head's sphericity or by sonography using the Graf method. Overall success rate was 91.6% for primary closed reduction. Patients with primarily irreducible hips were significantly older (p < 0.003) than patients with primarily successful reducible hips. Congenital dislocated hips had significantly higher ACIs (p < 0.001) and HCIs (p = 0.03) as well as significantly less well rounded femoral heads (sphericity; p < 0.001) compared to stable hips. Early diagnosis and treatment of congenital dislocated hips by closed reduction is essential for a sufficient and regular maturation of the hips without further surgical interventions.

Acetabular Anatomical Parameters in Patients With Idiopathic Osteonecrosis of the Femoral Head

BackgroundOsteonecrosis of the femoral head (ONFH) is an increasing worldwide health problem. However, about 30% of the patients are diagnosed with idiopathic ONFH, which means no underlying etiology is identified. We hypothesized that acetabular anatomical abnormalities might be related to idiopathic ONFH. MethodsThis retrospective, 1:2 matched, case-control study included 101 patients (136 hips) with idiopathic ONFH and 202 control subjects (404 hips) matched for age, gender, and body mass index who had no apparent radiographic hip pathologies. The anteroposterior pelvic X-rays of the patients and control subjects were used to measure the anatomical parameters including the center-edge angle, the sharp angle, the acetabular depth ratio (ADR), and the acetabular head index (AHI). ResultsWe found that hips with idiopathic osteonecrosis had less acetabular coverage, lower center-edge angle (28.3° vs 32.3°, P < .001), acetabular depth ratio (298.0 vs 306.4, P = .006), and acetabular head index (82.2 vs 85.8, P < .001), and higher sharp angle (39.7° vs 38.0°, P < .001), compared with the control subjects. The incidence of acetabular dysplasia was also higher in the idiopathic ONFH group than the control group. ConclusionLess acetabular coverage was found in hips with idiopathic osteonecrosis than the control subjects. Less acetabular coverage may be associated with the development of ONFH in East Asian population.

Long-Term Outcomes of Eccentric Rotational Acetabular Osteotomy Combined With Femoral Osteotomy for Hip Dysplasia

BackgroundThis study aimed at investigating the clinical outcomes of eccentric rotational acetabular osteotomy (ERAO) combined with intertrochanteric valgus osteotomy (ITVO) over a period of more than 10 years. MethodsThis is a case-control study of 39 patients (40 hips) who underwent ERAO combined with ITVO for hip dysplasia (ITVO group). Patients were matched for age, sex, follow-up period, and preoperative joint stage to 78 patients (80 hips) who underwent ERAO alone (ERAO group). We compared the clinical and radiographic outcomes and the survival rates between the groups. ResultsThe Harris Hip Score at the final follow-up was significantly lower in the ITVO group than in the ERAO group. The postoperative center edge angle, acetabular head index, and minimum joint space were significantly smaller in the ITVO group than in the ERAO group. The survival rates for the conversion to total hip arthroplasty end point were not significantly different between groups. However, survival rates for the Harris Hip Score < 80 end point were significantly poorer in the ITVO group than in the ERAO group. ConclusionThe long-term results of ERAO combined with ITVO were not satisfactory from a hip function perspective. ERAO combined with ITVO should be indicated in only young active patients with pre-osteoarthritis and initial stages of osteoarthritis.

Cross-Sectional Survey of Childhood Acetabular Development in Japan.

Introduction: We aimed to clarify childhood acetabular development and to identify the incidence of children’s hip dysplasia in Japan using radiographs of the contralateral hip. Methods: We performed radiological cross-sectional evaluation of hip development in 211 patients (106 boys, 211 hips) in different age groups (age range: 3–9 years). We excluded patients who complained of bilateral coxalgia at the first visit or had received a diagnosis of acetabular dysplasia. We measured the acetabular index (AI), center-edge angle (CEA), and acetabular head index (AHI) in plain radiographs taken at the first visit. Results: A significant correlation was found between age and CEA in boys, but other parameters had no significant correlation. The mean AI values in boys and girls were 18 ± 3° and 20 ± 4° (p < 0.01), respectively, and the mean CEA values were 25 ± 5° and 24 ± 5° (p = 0.43), respectively. The mean AHI values in boys and girls were 83 ± 6% and 81 ± 7%, respectively (p < 0.01). Two of the 120 children (66 boys and 54 girls) aged ≥6 years old had a hip CEA < 15°; both were girls. Conclusions: We found decreased acetabular development in girls, and 4% (2/54) of girls without any history of dislocation belonged to Severin’s group III. Acetabular dysplasia was observed more frequently in children from Japanese than in those from other countries. Girls with less than two standard deviations in hip dysplasia indices had an AI of 28°, an AHI of 67%, and a CEA of 14°. These reference values may be useful as prognostic indicators for hip dysplasia and OA in adulthood.

Proposal of a New Type of Innominate Osteotomy without the Use of Bone Graft in Children: A Preliminary Study.

Background:Good long-term outcomes have been reported for the Salter innominate osteotomy (SIO), which is widely used to correct developmental dysplasia of the hip (DDH) in children. In this study, we describe the procedure and early outcomes of a new pelvic osteotomy termed “angulated innominate osteotomy” (AIO).Methods:Twenty-one patients (22 hips) underwent AIO. We evaluated age at the time of surgery, operative time, blood loss, and time to bone union. Several radiographic parameters were assessed preoperatively, immediately postoperatively, and at the time of the latest examination. Measurements were compared with those of 20 previous patients who underwent SIO. The AIO is made to form an isosceles triangle. This enables 2 points of contact between the proximal and distal bone fragments, eliminating the need for a bone graft.Results:Mean age at the time of surgery was 5.9 years, and the mean duration of follow-up was 30.8 months. The mean operative time was 103 minutes, mean blood loss was 33 mL, and mean time to bone union was 9.8 weeks. Immediately postoperatively, the mean “distance d” (lateral displacement of the distal fragment), mean ratio of the obturator heights (ROH), and mean lateral rotation angle (LRA) were 7.2 mm, 70.4%, and 19.3°, respectively. At the latest examination, the mean acetabular index (AI), center-edge angle (CEA), and acetabular head index (AHI) were 16.4°, 23.7°, and 85.5%, respectively, each of which were significantly improved compared with the preoperative values. Moreover, the mean postoperative iliac length difference (ILD) between the operative and contralateral sides was only 0.1 mm. Those treated with AIO had a significantly shorter operative time and time to bone union, and less blood loss, than those treated with SIO. The mean distance d, ROH, and LRA did not differ significantly from SIO results, while the mean ILD was significantly less.Conclusions:AIO is a less-invasive procedure that does not require a bone graft, and the short-term outcomes were favorable. Sufficient coverage of the acetabulum with displacement of the distal bone fragment to an extent similar to SIO can be achieved; we consider AIO a worthy surgical procedure that has the potential to provide good long-term outcomes similar to those seen with SIO.Level of Evidence:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Single Versus Combined Procedures for Severely Involved Legg-Calvé-Perthes Disease.

The concept of containment as an effective approach to reduce the risk of femoral head deformity has been questioned because modest results have been achieved after nonoperative and operative treatments for severely involved Legg-Calvé-Perthes disease. Several reports have shown the limited effectiveness of some conventional single procedures. However, there is limited data on the effectiveness of combined procedures. The surgical group comprised 77 patients (mean age 8.3 y) and involved 79 hips. The average follow-up term was 9.5 years. Sixty-five patients were unilaterally involved and 12 patients were bilaterally involved (although 10 of the latter patients only received surgery on 1 hip). Among patients, 28 hips were classified as Herring class B/C border (>8 y old) and 51 hips were Herring class C. The 79 hips were divided into 2 treatment groups for further analysis: group 1, single procedures (femoral varus osteotomy) (n=47); group 2, combined procedures [femoral varus osteotomy+Dega (Pemberton) osteotomy] (n=32). Using Stulberg classification I and II (acceptable outcome), the final outcome was statistically significant for group 2 (21 hips, 65.6%) compared with group 1 (18 hips, 38.3%) (P=0.031). The average remodeling efficacy, defined as the change in caput index between preoperation and postoperation, was better in group 2 (12.7%) than in group 1 (3.9%) (P=0.005). The acetabulum-head index and α-angle were also statistically significant in group 2 than in group 1 at the last follow-up. Clinical evaluations were statistically significant in group 2 compared with group 1. Both clinically and radiologically, the combined procedure group demonstrated significantly better outcomes with accelerated remodeling in both the severely affected femoral heads and the acetabula compared with the single procedure group. With this procedure, we anticipate the increased likelihood of preventing or delaying coxarthroses in adulthood. Level III-therapeutic study.

How does iliosacral bone tumor resection without reconstruction affect the ipsilateral hip joint?

BackgroundWhether reconstruction is more beneficial after iliosacral bone tumor resection remains controversial. Because of high rates of complications and recurrence, few patients benefit from reconstruction. The aim of this study is to assess functional outcomes and to reveal changes in the ipsilateral hip joint after partial iliosacral resection.MethodsFrom 1998 to 2016, 21 patients aged 20–66 years underwent iliosacral resection, 18 without reconstruction (group 1) and 3 with reconstruction (group 2). Function was evaluated using the Musculoskeletal Tumor Society 1993 rating scale (MSTS 1993), and disability was measured using the Toronto Extremity Salvage Score (TESS). I-A distance was defined as the distance from the iliosacral joint to the upper line of the acetabulum along the curved line. Group 1 were subdivided into two groups: group 1A included the patients with a defect less than one-third of the I-A distance and group 1B the remainder. Acetabulum-head index (AHI) and center-edge angle (CE angle) were measured. The relationship between defect length and femoral head coverage was analyzed.ResultsThe mean follow-up was 67.3 months. Eighteen patients were included in group 1 and three in group 2. Preoperative data of the 3 groups were statistically equivalent. In addition, no difference of postoperative functional outcome has been highlighted. The final average MSTS 1993 score was 93.6% in group 1 and 93.3% in group 2. The mean TESS was 98 in group 1 and 98.5 in group 2. AHI and CE angle between groups 1 and 2 were not different. The AHI was 80 ± 5.4% in group 1A and 67 ± 9.0% in group 1B (t = − 3.740, P = 0.002), while the CE angle was 29 ± 5.9° in group 1A and 20 ± 6.3° in group 1B (t = − 3.172, P = 0.006) at the last follow-up. Regarding the limb-length discrepancy, group 1 and 2 were similar whereas group 1A and 1B were statistically different (group 1A: 0.7 ± 0.7 cm; group 2: 2.6 ± 1.0 cm; t = − 4.324, P = 0.001).ConclusionsIlio-sacral resection without reconstruction removing more than one- third of the I-A distance leads to an impairement of the limb-length discrepancy and an increase of the defect of the acetabular coverage without altering the functional outcome. Nevertheless, iliosacral resection without reconstruction could serve as a viable treatment option for pelvic type I-IV tumors.

Treatment outcome of dome osteotomy of the pelvis combined with trochanteric advancement for sequelae of Perthes' disease

ObjectiveDisparity in size between femoral head and acetabulum could promote premature degeneration of the hip joint. The purpose of this study was to report the results of Kawamura's dome osteotomy for acetabular dysplasia due to sequelae of Perthes' disease. Patients and MethodsFourteen patients (14 hips) operated between 1999 and 2012 were retrospectively reviewed. There were 9 males and 5 females with a mean age of 29 years (range, 15–54 years). Functional and radiological results were reviewed at mean follow-up of 9 years (range, 4–12 years). ResultsPain relief was obtained in 13 of 14 (92.8%) patients postoperatively. Good to excellent functional outcome was obtained in 10 of 14 (71.4%) patients. Mean Harris hip score was improved from 63 to 84 (p < 0.05) at the final follow-up. Improvement of limping gait was observed in 10 of 14 (71.4%) patients. Center edge angle improved from mean 24° (11–36°) preoperatively to mean 35° (27–46°) postoperatively (p < 0.05), acetabular angle improved from mean 43° (36–49°) preoperatively to mean 37° (32–44°) postoperatively (p < 0.05), acetabular head index improved from mean 69% (50–83%) preoperatively to mean 85% (73–100%) postoperatively (p < 0.05). Progression of arthrosis stage occurred in 3 of 14 (21%) patients. None of the hip with preoperative Stulberg III, 2 of 9 hips with Stulberg IV and 2 of 2 hips with Stulberg V needed conversion to total hip arthroplasty during the follow-up. ConclusionDome osteotomy of the pelvis combined with trochanteric advancement could give a reasonable treatment outcome for acetabular dysplasia due to Perthes' disease at mid to long-term follow-up. Advanced stage of arthrosis, preoperative Stulberg V and no improvement of limping gait after the surgery possibly associated with poor outcome. Level of evidenceLevel IV, therapeutic study.

Three different radiological indicators for diagnosis of adult acetabular dysplasia: study protocol for a diagnostic trial and preliminary results

Background and objectives: Acetabular dysplasia is often characterized by acetabular bone hyperplasia and osteonecrosis of the femoral head. These pathological changes can alter the position of the center of the femoral head, causing abnormal values on anteroposterior radiographs of the adult pelvis involving the Wiberg anterior center-edge (CE) angle, acetabular angle (Sharp angle), and acetabular head index, eventually resulting in the inaccurate diagnosis of acetabular dysplasia. Herein, we introduce and verify three X-ray indicators, offshoring index (OFI), moving up index (MUI) and teardrop baseline offshoring index (TBOI). All data will be expressed as relative ratios, as we expect to make an accurate diagnosis by avoiding the generation of errors resulting from measurement angles. Design: A single-center, diagnostic trial. Methods: Two hundred adult patients (100 female and 100 male) will be scheduled to undergo pelvic X-ray examinations at the Third Hospital of Hebei Medical University in China. The affected and healthy sides will be measured and analyzed using commercial software. Outcome measures and preliminary results: The primary outcome measure is the sensitivity of OFI of the femoral head for diagnosing adult acetabular dysplasia. Secondary outcome measures include the specificity, positive and negative predictive values, and positive and negative likelihood ratios of OFI, and sensitivity specificity, positive and negative predictive values, and positive and negative likelihood ratios of MUI and TBOI of the femoral head for diagnosing adult acetabular dysplasia as well as the rate of correct diagnosis; correlation of OFI, MUI and TBOI to CE angle, Sharp angle and acetabular head index; and risk factors for hip dysfunction as analyzed by logistic regression analysis. In our pre-tests, pelvic X-ray data from 241 male patients showed that the OFI, MUI and TBOI were 86.8 ± 0.6%, 75.8 ± 2.0% and 76.2 ± 0.5%, which closely correlated with CE angle, Sharp angle, and acetabular head index (AHI). Discussion: This study is designed to verify that three new X-ray indicators, OFI, MUI and TBOI, as diagnostic indicators for adult acetabular dysplasia, can increase diagnostic accuracy and effectively avoid diagnostic errors in comparison with the CE angle, Sharp angle, and AHI. Ethics and dissemination: The study was approved by the Ethics Committee of the Third Hospital of Hebei Medical University in China (approval No. KE2016-011-1). The study will be performed in accordance with the relevant laws and regulations of the Declaration of Helsinki. All the participatns will be fully informed of the study protocol and experimental process, and provide written informed consent with the premise of fully understanding the treatment plan. The results of this study will be disseminated in peer-reviewed journals or presented at scientific meetings. Trial registrations: This trial was registered in the Chinese Clinical Trial Registry with registration number: ChiCTR1800016375 (protocol version: 1.0).