Acetabular Roof Angle Research Articles

A 30-year follow-up study of rotational acetabular osteotomy for pre- and early-stage osteoarthritis secondary to dysplasia of the hip.

The objective of this study was to present the outcomes of rotational acetabular osteotomy (RAO) over a 30-year period for osteoarthritis (OA) secondary to dysplasia of the hip in pre- or early-stage OA. Between September 1987 and December 1994, we provided treatment to 47 patients (55 hips) with RAO for the management of pre- or early-stage OA due to developmental hip dysplasia. Of those, eight patients (11 hips) with pre-OA (follow-up rate 79%) and 27 patients (32 hips) with early-stage OA (follow-up rate 78%), totalling 35 patients (43 hips) (follow-up rate 78%), were available at a minimum of 28 years after surgery. In the pre-OA group, the mean Merle d'Aubigné score improved significantly from 14.5 points (SD 0.7) preoperatively to 17.4 points at final follow-up (SD 1.2; p = 0.004) and in the early-stage group, the mean score did not improve significantly from 14.0 (SD 0.3) to 14.6 (SD 2.4; p = 0.280). Radiologically, the centre-edge angle, acetabular roof angle, and head lateralization index were significantly improved postoperatively in both groups. Radiological progression of OA was observed in two patients (two hips) in the pre-OA group and 17 patients (18 hips) in the early-stage group. Kaplan-Meier survival analysis, with radiological progression of OA as the primary outcome, projected a 30-year survival rate of 81.8% (95% confidence interval (CI) 0.59 to 1.00) for the pre-OA group and 42.2% (95% CI 0.244 to 0.600) for the early-stage group. In all cases, the overall survival rate stood at 51.5% (95% CI 0.365 to 0.674) over a 30-year period, and when the endpoint was conversion to total hip arthroplasty, the survival rate was 74.0% (95% CI 0.608 to 0.873). For younger patients with pre-OA, joint preservation of over 30 years can be expected after RAO.

Impact of acetabular roof's angle on precision of cup center of rotation reproduction and placement in total hip arthroplasty.

Total hip arthroplasty (THA) is nowadays considered as the most effective treatment option for end-stage hip osteoarthritis (OA) and one of the most successful orthopedic procedures. Precise reproduction of the center of rotation (COR) is among the most important aspects of recreating native hip biomechanics after THA as it is strictly related to muscle tension and force distribution within the hip joint. Both vertical and horizontal shift in cup positioning and COR restoration are commonly observed radiological signs corresponding with lesser functional outcome. The aim of this study was to assess whether the superior border of the native acetabulum morphology has an impact on cup positioning and COR restoration in patients undergoing THA as treatment of primary OA of the hip. A cohort of 150 consecutive patients with diagnosis of end-stage primary hip OA who underwent THA via an anterolateral approach with the same implant in 2021 was analyzed retrospectively. Standard standing pelvic X-rays were performed pre- and postoperatively and appropriate measurements were taken. Several radiological parameters on obtained X-rays were assessed. Statistical analysis of all the measurements was performed. There was a statistically significant positive weak correlation between cup offset and acetabular roof angle (rs = 0.25, p = 0.002). There were statistically insignificant positive correlations between acetabular roof angle and COR restoration (rs = 0.14, p = 0.097), acetabular roof angle and total offset (rs = 0.087, p = 0.29) and a negative correlation between acetabular roof angle and femoral offset (rs = 0.071, p = 0.39). The present study revealed that preoperative acetabular roof angle influences the positioning of the prosthetic cup in the transverse axis. There also seems to be a correlation between the acetabular roof angle and COR restoration, but its significance needs further evaluation. Surgeons could use this knowledge to preoperatively assess the risk of cup malposition and adjust their technique during the THA procedure with probable improvement of hip function.

THIRTY-YEAR FOLLOW-UP STUDY OF ROTATIONAL ACETABULAR OSTEOTOMY

Satisfactory intermediate and long-term results of rotational acetabular osteotomy (RAO) for the treatment of early osteoarthritis secondary to developmental dysplasia of the hip have been reported. The purpose of this study is to examine the 30-year results of RAO.Between 1987 and 1994, we treated 49 patients (55 hips) with RAO for diagnosis of pre- OA or early-stage OA. Of those patients, 35 patients (43 hips) were available at a minimum of 28 years. The follow-up rate was 78.2% and the mean follow-up was 30.5 years. The mean age at the time of surgery was 34 years. Clinical evaluation was performed with the Merle d'Aubigne and Postel rating scale, and radiographic analyses included measurements of the center-edge angle, acetabular roof angle, and head lateralization index on preoperative, postoperative AP radiographs of the pelvis. Postoperative joint congruency was classified into four grades. The radiographic evidence of progression of OA was defined as the minimum joint space less than 2.5mm.The mean preoperative clinical score was 14.0, which improved to a mean of 15.3 at the time of the latest follow-up. The mean center-edge angle improved from 0.6° preoperatively to 34° postoperatively, the mean acetabular roof angle improved from 28.4°preoperatively to 1.0°postoperatively, the mean head lateralization index improved from 0.642 preoperatively to 0.59 postoperatively. Postoperative joint congruency was excellent in 11 hips, good in 29 hips, and fair in 3 hips. Nineteen patients (20 hips) had radiographic OA progression, and 10 patients (11 hips) were converted to THA. Kaplan-Meier survivorship analysis, with radiographic OA progression as the end point, predicted survival of 75.6% at 20 years and 48.8% at 30 years, and with THA conversion as the end point, 90.2% at 20 years and 71.2% at 30 years.The RAO is an effective surgical procedure for symptomatic dysplastic hips of pre- and early-stage OA and could change the natural history of the dysplastic hip.

Performance of Tönnis triple osteotomy in older children with developmental dysplasia of the hip (DDH) assisted by a 3D printing navigation template

BackgroundThe objective of this study is to investigate the preparation of a navigation template via a computer-aided design (CAD) and 3D printing (3DP) in order to improve the effectiveness of Tönnis triple osteotomy in older children with developmental dysplasia of the hip (DDH).MethodThirty-eight older children who received Tönnis triple osteotomy were included in this study. Among them, 20 were categorized as the 3DP navigation template group (3DP group), and the remaining 18 were categorized as the conventional surgery group (CS group). Data, including preoperative and postoperative pelvic sharp angle (SA), lateral center-edge angle (LCEA), acetabular roof angle (ARA), acetabular head index (AHI), crossover sign (COS), ischial spine sign (ISS), operation time (OT), intraoperative blood loss (IBL), and number of radiation exposures (NORE) were recorded for both groups. In addition, the therapeutic effect was evaluated at the last follow-up, according to the McKay criteria and Severin’s criteria.ResultsIn the 3DP and CS groups, the mean OT was 126.6 ± 17.6 min and 156.0 ± 18.6 min, respectively; the mean IBL was 115.0 ± 16.9 ml and 135.7 ± 26.5 ml, respectively; the NORE were 3.3 ± 0.8 times and 8.6 ± 1.3 times, respectively. There were significant differences in the OT, IBL, and NORE between the two groups (P = 0.03, 0.05, < 0.001, respectively). At the last follow-up, the 3DP and CS groups displayed SA of 41.8 ± 2.3° and 42.6 ± 3.1°, respectively; LCEA of 35.6 ± 4.2° and 37.1 ± 2.8°, respectively; ARA of 6.9 ± 1.8° and 9.8 ± 2.6°, respectively; and AHI of 86.6 ± 4.1% and 84.3 ± 2.8%, respectively; COS(+) of 5 hips and 4 hips, respectively; ISS(+) of 6 hips and 7 hips. We observed no statistical differences in the SA, LCEA, ARA, AHI, COS and ISS between the two groups (P = 0.918, 0.846, 0.643, 0.891, 0.841, 0.564, respectively). According to the McKay criteria, the 3DP group had 10 excellent, 6 good, and 4 general hips, whereas, the CS group had 12 excellent, 4 good, and 2 general hip. There was no statistical difference between the two groups (P = 0.698). In 3DP group the postoperative Severin’s grading included 13 hips in grade I, 4 in grade II, 3 in grade III. Alternately, in the CS group, the postoperative Severin’s grading included 11 hips in grade I, 5 in grade II, 2 in grade III. The Severin ‘s criteria also showed no statistical difference between the two groups (P = 0.945).ConclusionsBase on our analysis, our CAD-3DP-fabricated navigation template assisted Tönnis triple osteotomy in older DDH children, it reduced operation time and number of radiation exposures. However, no significant differences in radiological assessment and functional outcomes were observed when an experienced surgeon performs the surgery. Therefore, Surgeons who have less experience in triple osteotomy profit more from the application of this technology.

Overcorrection of the acetabular roof angle or anterior center-edge angle may cause decrease of range of motion after curved periacetabular osteotomy.

ABSTRACT The aim of this study was to evaluate the relationship between the correction of radiographic parameters and clinical range of motion (ROM) after periacetabular osteotomy (PAO). Sixty-nine patients with hip dysplasia were enrolled and underwent curved PAO. The pre- and post-operative 3D center–edge (CE) angles, total anteversion (acetabular and femoral anteversion), and radiographic acetabular roof angle were measured and compared with the post-operative ROM. The aim of surgery was to rotate the central acetabular fragment laterally without anterior or posterior rotation. Multiple linear regression analysis demonstrated that post-operative internal rotation at 90° flexion was significantly associated with the post-operative Tönnis sourcil angle (rr = 0.31, P = 0.02) and that the post-operative ROM of flexion and internal rotation at 90° flexion were significantly associated with the anterior CE (flex; rr = −0.44, P = 0.001, internal rotation at 90° flexion; rr = −0.44, P < 0.001). However, we found no association between the lateral CE, femoral anteversion, or total anteversion and the post-operative ROM. We demonstrated that the overcorrection of the acetabular roof angle or anterior CE angle may cause a decrease in the range of motion after curved PAO. Therefore, surgeons need to be careful during surgery to prevent the overcorrection of the weight-bearing area and anterior acetabular coverage of the acetabular fragment to avoid femoroacetabular impingement after PAO.

Rotational acetabular osteotomy for symptomatic hip dysplasia in patients younger than 21 years of age: seven- to 30-year survival outcomes.

The aim of this study was to report the long-term results of rotational acetabular osteotomy (RAO) for symptomatic hip dysplasia in patients aged younger than 21 years at the time of surgery. We evaluated 31 patients (37 hips) aged younger than 21 years at the time of surgery retrospectively. There were 29 female and two male patients. Their mean age at the time of surgery was 17.4 years (12 to 21). The mean follow-up was 17.9 years (7 to 30). The RAO was combined with a varus or valgus femoral osteotomy or a greater trochanteric displacement in eight hips, as instability or congruence of the hip could not be corrected adequately using RAO alone. The mean Merle d'Aubigné clinical score improved significantly from 15.4 to 17.2 (p < 0.0001). The mean centre-edge (CE) angle improved from -2.6° to 26°, the mean acetabular roof angle improved from 3.0° to 5.2°, and the mean head lateralization index improved from 0.68 to 0.62. Progression of radiological osteoarthritis (OA) was seen in seven hips, but no patient underwent total hip arthroplasty. RAO is an effective form of correction for a severely dysplastic hip in adolescent and young adult patients. Cite this article: Bone Joint J 2019;101-B:390-395.

Periacetabular Osteotomy Improves Pain and Function in Patients With Lateral Center-edge Angle Between 18° and 25°, but Are These Hips Really Borderline Dysplastic?

AbstractBackgroundThe treatment of mild or borderline acetabular dysplasia is controversial with surgical options including both arthroscopic labral repair with capsular closure or plication and periacetabular osteotomy (PAO). The degree to which improvements in pain and function might be achieved u

Comparison of acetabular and femoral morphologies on hip, pelvic, and lumbar radiographs

PurposeTo evaluate the reliability of the parameters for acetabular/femoral pathomorphologies in L-spine and hip radiographs compared to pelvic radiographs. MethodsA retrospective review of L-spine, hip, and pelvic radiographs from 101 patients was performed. Three radiologists independently measured five parameters (acetabular roof angle of Tönnis [Tönnis angle], center-edge-angle of Wiberg [CEA], femoral head extrusion index [FHEI], cross-over sign, pistol-grip deformity) in each radiograph. ResultsNo significant differences were identified (p ≥ 0.07) except Tönnis angles and FHEIs from the L-spine radiographs. Inter-radiograph/inter-reader ICCs were excellent or good. ConclusionPathomorphology-related measurements in L-spine radiographs can also be used as alternatives to those in pelvic or hip radiographs. If L-spine radiographs are already available, additional pelvic or hip radiographs may be unnecessary, thus reducing patients' overall radiation exposure.

Values for bony acetabular roof angle and percentage femoral head cover in a selective ultrasound neonatal hip-screening programme: effect of age, sex and side.

Published maturation curves for bony acetabular roof or α angle (AA) and percentage femoral head cover (FHC) with age are sparse. We aimed to determine typical values for AA and FHC in 2236 infants referred to a selective ultrasound screening programme. There was increase in the values of first measurement of AA and FHC related to the logarithm of age. Males had greater values than females (P<0.001) and right hips had greater values than left (P<0.001) for both measurements. Significant side differences have not been reported previously. Treatment decisions should be made on the basis of sex, side and age-specific data.

Percutaneous medial hemi-epiphysiodesis using a transphyseal screw for caput valgum associated with developmental dysplasia of the hip

BackgroundThe purpose of this study was to evaluate the radiologic outcome of percutaneous medial hemi-epiphysiodesis using a transphyseal screw for the management of caput valgum associated with developmental dysplasia of the hip (DDH).MethodsEighteen hips (18 patients) having caput valgum treated with screw hemi-epiphysiodesis were followed for more than 2 years, and were included in this study. The mean age at the time of the index operation was 8.3 years (range, 4.3 to 10.7 years) and age at the latest follow-up was 12.2 years (range, 9.4 to 16.4 years). The screw in 5 hips was changed into a longer one at postoperative 21.8 months (range, 14 to 29 months) because the proximal femur outgrew the screw. The screws in 11 hips were removed at the mean age of 10.9 years (range, 8.0 to 14.5 years). We retrospectively analyzed the change in various radiologic parameters over time.ResultsThe mean Hilgenreiner-epiphyseal angle (HEA) of the operated side was 5.1 ± 11.3° preoperatively, and increased to 20.6 ± 11.3° at the latest follow-up (p = 0.001). The mean difference of the HEA between the operated and contralateral sides was 16.9 ± 15.1° preoperatively, which decreased to 2.4 ± 12.4° at the latest follow-up (p = 0.008). The mean articulo-trochanteric distance of the operated side, which was 3.2 ± 5.5 mm longer than that of the contralateral side preoperatively, became 5.6 ± 9.1 mm shorter at the latest follow-up (p = 0.001). The ratio of femoral neck length of the operated side to that of the contralateral side decreased over the follow-up period. Acetabular shape as measured by the Sharp angle and acetabular roof angle and femoral head coverage as measured by lateral center-edge angle did not change significantly by the index operation. The ratio of medial joint space width of the operated side to that of the contralateral side did not change significantly.ConclusionsScrew medial hemi-epiphysiodesis can effectively correct caput valgum associated with DDH. However, this technique remains coxa brevis and does not seem to significantly affect acetabular morphology or reduce subluxation.

Radiological Evaluation of Hip in Cerebral Palsy: A Randomized Cross-sectional Study

ABSTRACTIntroductionThe incidence of hip abnormalities in cerebral palsy (CP) patients has been reported as low as 2.6% and as high as 28%. Hip displacement is the second most common deformity after equines. The objective of this study is to evaluate the radiological changes of hip in CP for detecting early features of hip instability.Materials and methodsA total of 91 hips of 52 patients with CP who attended for rehabilitation management were randomly selected for the study. Hip surveillance was done in those cases where the clinical evaluation alone could not access stability. All the selected cases were evaluated radiologically with respect to acetabular angle, neck-shaft angles, degree of subluxation (migration percentage) and shape of femoral head.Results38 hips showed grade I, 14 hips grade II, 6 hips grade III, and 2 hips grade IV stage of migration percentage. Flattening of femoral head was laterally seen in 16 cases, both medial and lateral flattening was seen in 8 cases of subluxated hip. Acetabular roof angle was increased in cases with grade III and IV migration percentage. Acetabular angle was within 12 to 75° with mean angle of 32°. The mean true neck-shaft angle was 145.5° ranging from 134° to 170°ConclusionEarly detection of hip instability in Cerebral Palsy helps in timely intervention and that reduces or delays need for reconstructive surgery.How to cite this articleSahoo PK, Sahu MM, Chitapure T, Das SP. Radiological Evaluation of Hip in Cerebral Palsy: A Randomized Cross-sectional Study. Indian J Phy Med Rehab 2017;28(3):95-99.

Rotational Acetabular Osteotomy for Pre- and Early Osteoarthritis Secondary to Dysplasia Provides Durable Results at 20Years.

Hip dysplasia is a common cause of secondary osteoarthritis (OA). Periacetabular osteotomy or rotational acetabular osteotomy has been used as joint-preserving procedures. However, only a few reports of long-term results with these operations have been reported. (1) Would satisfactory clinical and radiographic outcomes be maintained at a mean duration of 20 years after rotational acetabular osteotomy for pre- and early-stage OA; and (2) could we identify risk factors for radiographic progression of OA? Between 1987 and 2001, we treated 159 patients (173 hips) with rotational acetabular osteotomies for the diagnosis of pre-OA or early-stage OA according to the technique of Ninomiya and Tagawa. During that period, our general indications for this approach were age younger than 60 years, center-edge angle less than 20°, and improved femoral head coverage and joint congruency on preoperative AP plain radiographs of the hip in abduction; we did not use this approach when joint congruency was not improved or no widening of the joint space was noted on preoperative AP plain radiographs of the hip in abduction. Of those patients, 21 patients with pre-OA (followup rate: 84% [27 hips]) and 110 patients in the early-stage group (followup rate: 82% [118 hips]) were available at a minimum of 15 years for a total patient group of 131 (followup rate: 82% [145 hips]). The mean age at the time of surgery was 22 years in the pre-OA group and 38 years in the early-stage group. The mean followup was 21 years in the pre-OA group and 20 years in the early-stage group. Clinical evaluation was performed with the Merle d'Aubigne and Postel rating scale, and radiographic analyses included measurements of the center-edge angle, acetabular roof angle, and head lateralization index on preoperative and postoperative AP radiographs of the pelvis. Postoperative joint congruency was also evaluated. The cumulative probabilities of radiographic signs of OA progression were estimated with use of the Kaplan-Meier product-limited method and parametric survivorship analysis using the Cox proportional-hazards model was used to determine risk factors for radiographic OA progression. The mean clinical score improved very slightly, from 15 (SD, 0.8) to 18 (SD, 1.1) (95% confidence interval [CI], -2.9 to -2.0; p < 0.001) in the pre-OA group and from 15 (SD, 1.0) to 16 (SD, 2.1) (95% CI, -2.0 to -1.2; p < 0.001) in the early-stage group at followup. Fourteen patients (15 hips) including one pre-OA patient (one hip) and 13 early-stage patients (14 hips) experienced worsening of their Merle d'Aubigne and Postel score, from a mean of 15 (SD, 0.9) to 12 (SD, 1.6) (95% CI, 1.8-3.3; p < 0.001). Eight patients (nine hips) with early-stage OA preoperatively underwent total hip arthroplasty at a mean duration after rotational acetabular osteotomy of 20 (SD, 2.5) years. Radiographic indices were improved after surgery in both groups. Radiographic progression of OA occurred in 24 patients (25 hips). Kaplan-Meier survivorship analysis, with radiographic signs of progression of OA as the endpoint, predicted survival of 96% (95% CI, 89%-100%) at 10 years and 20 years in the pre-OA group. For the early-stage group, we found survivorship of 89% (95% CI, 83%-95%) at 10 years and 78% (95% CI, 69%-87%) at 20 years. We identified two factors associated with poor outcome: fair (rather than excellent and good) postoperative joint congruency (hazard ratio, 12.1; 95% CI, 3.8-39; p < 0.001) and age older than 46 years at the time of surgery (hazard ratio, 4.6; 95% CI, 1.9-11; p < 0.01). Rotational acetabular osteotomy is an effective surgical procedure for symptomatic dysplastic hips in pre- and early-stage OA, and it prevented radiographic OA progression and maintained hip function at a mean 20 years after surgery. Level IV, therapeutic study.

Decreased Lumbar Lordosis and Deficient Acetabular Coverage Are Risk Factors for Subchondral Insufficiency Fracture.

Subchondral insufficiency fracture (SIF) of the femoral head occurs in the elderly and recipients of organ transplantation. Osteoporosis and deficient lateral coverage of the acetabulum are known risk factors for SIF. There has been no study about relation between spinopelvic alignment and anterior acetabular coverage with SIF. We therefore asked whether a decrease of lumbar lordosis and a deficiency in the anterior acetabular coverage are risk factors. We investigated 37 patients with SIF. There were 33 women and 4 men, and their mean age was 71.5 years (59-85 years). These 37 patients were matched with 37 controls for gender, age, height, weight, body mass index and bone mineral density. We compared the lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, acetabular index, acetabular roof angle, acetabular head index, anterior center-edge angle and lateral center-edge angle. Lumbar lordosis, pelvic tilt, sacral slope, lateral center edge angle, anterior center edge angle, acetabular index and acetabular head index were significantly different between SIF group and control group. Lumbar lordosis (OR = 1.11), lateral center edge angle (OR = 1.30) and anterior center edge angle (OR = 1.27) had significant associations in multivariate analysis. Decreased lumbar lordosis and deficient anterior coverage of the acetabulum are risk factors for SIF as well as decreased lateral coverage of the acetabulum.

Surgical Treatment of Adolescent Acetabular Dysplasia With a Periacetabular Osteotomy: Does Obesity Increase the Risk of Complications?

The Bernese periacetabular osteotomy (PAO) is frequently used to treat symptomatic acetabular dysplasia in the adolescent age group. Despite encouraging results, factors predictive of the development of postoperative complications remain poorly understood. The purpose of this study was to investigate whether obesity is a risk factor for complications following PAO in adolescents. A retrospective cohort study design was used to collect data from 3 different institutions. Children and adolescents (below 19 y of age) who underwent PAO and were followed for minimum of 12 months were included. Obesity was defined as a body mass index ≥95 percentile. The modified Clavien-Dindo classification was used to grade complications. A logistic regression analysis was used to identify factors related to the development of a complication that required treatment outside of routine postoperative care (complication grades II to V). Changes in radiographic parameters including Tönnis acetabular roof angle, anterior center-edge angle, and lateral center-edge angle among obese versus nonobese subjects were also evaluated. The mean age at surgery among the 84 adolescents included in the study was 16.5 years (range, 12 to 19 y). A total of 11% of the population was considered obese. Obesity (P=0.0047) was the only variable significantly associated with the development of a complication. After controlling for study site, the odds of an obese subject developing a complication were 10 [95% confidence interval (CI), 1.89-59.8] times the odds of a nonobese subject developing a complication. There was no difference in the magnitude of change in anterior center-edge angle (P=0.1251), lateral center-edge angle (P=0.9774), or Tönnis (P=0.5770) angular correction that was achieved among the obese versus nonobese subjects following surgery. The Bernese PAO allows for adequate radiographic correction of acetabular dysplasia among obese and nonobese adolescents. However, the hip preservation surgeon should be aware of the higher risk of complications among obese adolescents undergoing PAO for the treatment of symptomatic acetabular dysplasia. Level III-retrospective study.

Hip Arthroscopy: Where We Are, and Where We Are Going.

Hip Arthroscopy: Where We Are, and Where We Are Going.

Effects of rotational acetabular osteotomy on the mechanical stress within the hip joint in patients with developmental dysplasia of the hip: a subject-specific finite element analysis.

In this study we used subject-specific finite element analysis to investigate the mechanical effects of rotational acetabular osteotomy (RAO) on the hip joint and analysed the correlation between various radiological measurements and mechanical stress in the hip joint. We evaluated 13 hips in 12 patients (two men and ten women, mean age at surgery 32.0 years; 19 to 46) with developmental dysplasia of the hip (DDH) who were treated by RAO. Subject-specific finite element models were constructed from CT data. The centre-edge (CE) angle, acetabular head index (AHI), acetabular angle and acetabular roof angle (ARA) were measured on anteroposterior pelvic radiographs taken before and after RAO. The relationship between equivalent stress in the hip joint and radiological measurements was analysed. The equivalent stress in the acetabulum decreased from 4.1 MPa (2.7 to 6.5) pre-operatively to 2.8 MPa (1.8 to 3.6) post-operatively (p < 0.01). There was a moderate correlation between equivalent stress in the acetabulum and the radiological measurements: CE angle (R = -0.645, p < 0.01); AHI (R = -0.603, p < 0.01); acetabular angle (R = 0.484, p = 0.02); and ARA (R = 0.572, p < 0.01). The equivalent stress in the acetabulum of patients with DDH decreased after RAO. Correction of the CE angle, AHI and ARA was considered to be important in reducing the mechanical stress in the hip joint.

Relationship between developmental dislocation of the hip in infant and acetabular dysplasia at skeletal maturity.

Previous reports demonstrated 8–60% patients treated for developmental dislocation of hip (DDH) in infancy have residual acetabular dysplasia (AD) at skeletal maturity. AD patients reportedly exhibit abnormal morphology of the pelvis, high rates of comorbid spinal congenital anomalies and high bone mineral density. These physical findings suggest that AD patients have genetic background. We examined the percentage of AD patients with hip pain at skeletal maturity having a history of DDH in infancy and the correlation between the severity of AD at skeletal maturity and history of DDH treatment to investigate the relationship between AD and DDH.A total of 245 patients were radiographically examined for any history of DDH treatment in infancy. The study included 226 women and 19 men with a mean age at examination of 40.7 years (range 17–59 years).Eighty-eight patients (36%) had a history of DDH treatment (DDH group) and the remaining 157 patients (64%) had no history of DDH treatment (non-DDH group). The average age was lower and acetabular angle was larger in the DDH group. There was a significant increasing trend of the percentage of DDH patients associated with the severity of AD classified with CE, acetabular angle, and acetabular roof angle.Our data suggest that there are several AD patients without a history of DDH in Japan, and AD in patients without a history of DDH has different characteristics from AD in patients with a history of DDH.

Femoral head deformity and severity of acetabular dysplasia of the hip

Patients with acetabular dysplasia commonly undergo peri-acetabular osteotomy after skeletal maturity to reduce the risk of the late development of osteoarthritis. Several studies have suggested that deformity of the femoral head influences the long-term outcome. We radiologically examined 224 hips in 112 patients with acetabular dysplasia and early-stage osteoarthritis. There were 103 women and nine men with a mean age of 37.6 years (18 to 49). A total of 201 hips were placed in the acetabular dysplasia group and 23 in a normal group. The centre-edge angle and acetabular head index were significantly smaller (both p < 0.001), and the acetabular angle, acetabular roof angle and roundness index were significantly greater in the acetabular dysplasia group than those in the normal group (all p < 0.001). There were significant correlations between the roundness index and other parameters. Femoral head shape may be influenced by the severity of the acetabular dysplasia.

Hip Dysplasia Is More Severe in Charcot-Marie-Tooth Disease Than in Developmental Dysplasia of the Hip

Patients with Charcot-Marie-Tooth disease may develop hip dysplasia. Hip geometry in these patients has not been well described in the literature. We compared the hip morphometry in Charcot-Marie-Tooth hip dysplasia (CMTHD) and developmental dysplasia of the hip (DDH) in terms of extent of (1) acetabular dysplasia and subluxation, (2) acetabular anteversion and osseous support, (3) coxa valga and femoral version, and (4) osteoarthritis. Fourteen patients with CMTHD (19 hips; mean age, 23 years) presenting for periacetabular osteotomy were matched to 45 patients with DDH (45 hips; mean age, 21 years) based on age, sex, and BMI. We assessed acetabular dysplasia and subluxation using lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), and acetabular roof angle of Tönnis (TA) on plain pelvic radiographs and acetabular volume, area of femoral head covered by acetabulum, and percentage of femoral head covered by acetabulum on three-dimensional CT reconstruction models. Acetabular version and bony support, femoral version, and neck-shaft angle were measured on two-dimensional axial CT scans. Hip osteoarthritis was graded radiographically according to Tönnis criteria. Acetabular dysplasia was more severe in CMTHD, as measured by smaller LCEA (p < 0.001), ACEA (p < 0.001), and acetabular volume (p = 0.0178) and larger TA (p = 0.025). Hip subluxation was more pronounced in CMTHD, as demonstrated by lower area of femoral head covered by acetabulum (p = 0.034) and percentage of femoral head covered by acetabulum (p = 0.007). CMTHD was associated with higher acetabular anteversion (p < 0.001), lower anterior (p < 0.001) and posterior (p = 0.072) osseous support, and more severe coxa valga (p < 0.001). More (p = 0.006) arthritic hips were found in CMTHD. The extent of acetabular dysplasia, hip subluxation, acetabular anteversion, coxa valga, and hip osteoarthritis was more severe in CMTHD. These findings are important in choosing the appropriate surgical strategy for patients affected by CMTHD.

Radiologic Measurements Associated With the Prognosis and Need for Surgery in Patients With Subchondral Insufficiency Fractures of the Femoral Head

The objective of this study was to identify the risk factors associated with the prognosis and need for surgery of patients with subchondral insufficiency fractures of the femoral head. Twenty-nine consecutively registered patients with subchondral insufficiency fractures of the femoral head were divided into the two groups: a non-progression of collapse group, which included patients who had no collapse or 2 mm or less of collapse of the femoral head and whose symptoms resolved (14 patients), and a progression of collapse group, which included patients who had more than 2 mm of collapse, for which surgery was indicated (15 patients). Both groups received the same conservative therapy. The following radiographic measurements were obtained: Sharp angle, center edge angle, acetabular roof angle, and acetabular head index. On MR images, band length, defined as the length of a low-signal-intensity band in the coronal plane, and band length ratio, defined as the proportion of the band length relative to the weight bearing portion, were assessed for each patient. Bone mineral density measurements (T score) were available for 17 patients. In the univariate analyses, T score, Sharp angle, center edge angle, acetabular roof angle, acetabular head index, band length, and band length ratio were found to be significant prognostic factors. Multivariate analyses of T score, acetabular head index, and band length ratio showed that both acetabular head index and band length ratio were significant predictors. Both acetabular head index and band length ratio are important prognostic factors in the care of patients with subchondral insufficiency fractures of the femoral head.