The natural course of osteoarthritis of the hip due to subluxation or acetabular dysplasia

Preoperative Sarcopenia Severity and Clinical Outcomes after Total Hip Arthroplasty

The outcome of total hip arthroplasty (THA) in patients with end-stage arthritis of the hip is associated with preoperative physical status. This study was performed to examine the relationship between the preoperative severity of sarcopenia and clinical outcomes after THA. This retrospective cohort study was performed among 306 consecutive patients (mean age: 63.7 ± 12.9 years, 222 women) undergoing THA at a university hospital. The severity of sarcopenia was determined based on the skeletal muscle mass index (SMI), handgrip strength, and gait speed according to the criteria of the Asian Working Group for Sarcopenia 2019. The severe sarcopenia prevalence rate was 10.6%. Severe sarcopenia was significantly associated with the risk of delayed functional recovery (adjusted odds ratio, 2.82; 95% confidence interval, 1.03-7.72; p = 0.043) compared with the non-sarcopenia group after adjusting for pre-existing risk factors, including preoperative hip function and physical activity. The addition of SMI, handgrip strength, and gait speed to the model for risk of functional recovery delay significantly increased the area under the receiver operating characteristic curve (p = 0.038). Severe sarcopenia was significantly associated with poorer hip function and patient-reported outcomes at 6 months after surgery compared with the non-sarcopenia group. Severe sarcopenia was adversely associated with postoperative clinical outcomes in patients undergoing THA.

Long-term course of developmental dysplasia of the hip: follow-up of the non-operated hips of patients undergoing unilateral rotational acetabular osteotomy for twenty-four years

PURPOSE

To follow-up the non-operated hips of patients who underwent unilateral rotational acetabular osteotomy (RAO) for bilateral developmental dysplasia of the hip (DDH) for a minimum of 20 years to clarify (1) the timing of onset of hip osteoarthritis (OA) in DDH, and (2) factors associated with the development of OA.

METHODS

This study included 92 non-operated hips of patients who underwent unilateral RAO for bilateral DDH. We examined the timing of OA onset and total hip arthroplasty (THA) and the joint survival rate in the studied hips. Furthermore, the patients were divided into those with OA onset (progression group) and those without OA onset and compared in terms of lateral center-edge angle (LCEA), sharp angle, acetabular head index (AHI), acetabular roof obliquity (ARO), joint congruity, and the presence or absence of OA progression on the RAO side.

RESULTS

The progression group experienced OA onset 12 years after RAO and underwent THA 6 years after OA onset. The 20-year joint survival rate was 73% with the endpoint of OA onset and 81% with the endpoint of THA. The progression group had significantly smaller LCEA and AHI and larger ARO. The risk of developing OA was 8.2 times greater in patients with LCEA ≤ 7° than in those with LCEA > 7°.

CONCLUSION

The patients with OA progression group experienced OA onset at an average age of 55 years. A small LCEA (≤ 7°) was identified as a risk factor for the development of OA.

Universal Ultrasound Screening for Developmental Dysplasia of the Hip Among Infants in Community Settings in Japan: A Scoping Review

Introduction

Early identification of developmental dysplasia of the hip (DDH) is necessary to minimize its negative effects. Ultrasound screening is useful for detecting DDH in hospitals. Awareness about community-based screening systems is low in Japan. Despite established nationwide home visiting services and child health checkups in the country, more than 10% of DDH patients are diagnosed at the age of ≥1 year. This review aimed to clarify the status of universal ultrasound screening for DDH among infants in community settings in Japan.

Methods

The electronic databases of Igaku Chuo Zasshi, MEDLINE, CHINAL, ERIC, and APA PsycInfo were searched for articles published between 2002 and 2022. Articles were evaluated with the reach, effectiveness, adoption, implementation, and maintenance framework.

Results

In total, 148 articles were identified. Two articles were manually added, and 67 articles were excluded through abstract reviews, of which 20 were duplicates. Finally, 18 articles were included in the analysis. There are two types of universal ultrasound screening in community settings: municipality-led and hospital-led. Since 1992, municipality-led screening has been conducted during public infant health checkups in five municipalities. Six hospitals implemented ultrasound screening. The participation rate was around 90%. The Graf method is typically used for this purpose. The prevalence of abnormal hips was 3.6%-16.6%. Owing to limited human resources and skills in ultrasound, all studies mentioned the necessity of a universal screening system for the early detection of DDH.

Conclusion

Embedding universal ultrasound screening in community health checkup systems enables collaboration between healthcare professionals and caregivers to improve health inequities and ensure early detection of DDH cases.

The outcomes of total hip arthroplasty in developmental dysplasia of hip versus osteoarthritis: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to compare the outcomes of total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH) and those with osteoarthritis (OA).

METHODS

Four databases were searched from inception till February 2023 for original studies that compared the outcomes of THA in DDH and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and failure modes (i.e. aseptic loosening, PJI, instability, and periprosthetic fractures), hospital stay and costs. This review was conducted as per PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 9 observational studies with 575,255 THA (469,224 hips) were included, with a mean age of 50.6 years and 62.1 years for DDH and OA groups, respectively. There was a statistically significant difference in revision rate between DDH and OA patients in favour of OA (OR, 1.66; 95% CI 1.11-2.48; p-value, 0.0251). However, dislocation rate (OR, 1.78, 95% CI 0.58-5.51; p-value, 0.200), aseptic loosening (OR, 1.69; 95% CI 0.26-10.84; p-value, 0.346) and PJI (OR, 0.76; 95% CI 0.56-1.03; p-value, 0.063) were comparable across both groups.

CONCLUSION

A higher revision rate following total hip arthroplasty was associated with DDH compared with osteoarthritis. However, both groups had similar dislocation rates, aseptic loosening and PJI. Consideration of confounding factors, such as patient age and activity level, is crucial when interpreting these findings. LEVEL OF EVIDENCE : III.

TRIAL REGISTRATION

PROSPERO registration: CRD42023396192.

Hydroxyapatite-coated compaction short stem represents a characteristic pattern of peri-prosthetic bone remodelling after total hip arthroplasty

PURPOSE

We aimed to investigate the differences in peri-prosthetic bone remodelling between the full hydroxyapatite (HA)-collared compaction short stem and the short tapered-wedge stem.

METHODS

This retrospective cohort study enrolled 159 consecutive patients (159 joints) undergoing total hip arthroplasty (THA) using the full HA compaction short (n = 64) and short tapered-wedge (n = 95) stems. Body mass index (BMI), peri-prosthetic bone mineral density (BMD), and clinical factors, including the Japanese Orthopaedic Association score and the University of California Los Angeles (UCLA) activity score were assessed and compared.

RESULTS

Stem related complications were seen in three cases. Both groups showed similar peri-prosthetic BMD changes. Peri-prosthetic BMD was almost maintained in the distal femur and Gruen zone 6 with both type of stems, but significant BMD loss was found in zones 1 and 7 in both groups and in zone 2 of the full HA compaction stem group. No significant correlations were found between the proximal femoral BMD changes and the age, BMI, and UCLA score in both the full HA compaction and tapered-wedge stem groups. Femoral bone shape affected the peri-prosthetic BMD changes in the tapered-wedge stem group but not in the full HA compaction group. The stem collar of the full HA compaction stem did not affect peri-prosthetic BMD, but unique bone remodelling in the calcar region was observed in 27.6% cases. A significant difference in the peri-prosthetic BMD changes at Gruen zone 2 was found in patients with or without thigh pain.

CONCLUSION

Peri-prosthetic bone remodelling remained unaffected by clinical and radiographic factors after THA with the new short full HA compaction stem. Therefore, this new stem may be useful in a variety of cases.

"Anterior-shift sign": a novel MRI finding of adult hip dysplasia

INTRODUCTION

In adult hip dysplasia, methods for direct evaluation of hip instability have not been established. The present study aimed to determine findings suggestive of hip instability on magnetic resonance imaging (MRI) and to evaluate their correlations with clinical and radiological factors.

MATERIALS AND METHODS

We retrospectively reviewed 72 hips in 50 patients with hip dysplasia (45 females, 5 males; mean age: 40.0 years; age range: 15-59 years; Kellgren-Lawrence grade: ≤ 2). Hip dysplasia was defined as a lateral center-edge angle < 25°. Among the hips, 50 had pain (symptomatic dysplasia group) and 22 were asymptomatic (asymptomatic dysplasia group). As controls, 12 normal hips in 12 patients who underwent screening for asymptomatic osteonecrosis of the femoral head by MRI were evaluated. Using an oblique axial view on fat-suppressed T2-weighted images, we evaluated the presence of a gap between the posterior part of the femoral head and the corresponding acetabular surface, indicating hip instability (anterior-shift sign). The correlations of anterior-shift sign with clinical and radiographical factors were examined.

RESULTS

Anterior-shift sign was observed in 92.0% in the symptomatic dysplasia group, 9.1% in the asymptomatic dysplasia group, and 0% in the control group. In adult hip dysplasia, cases with anterior-shift sign had significantly more pain and labrum tear occurrence than cases without anterior-shift sign. Anterior-shift sign was correlated with Kellgren-Lawrence grade and degree of acetabular coverage.

CONCLUSIONS

This study suggested that hip instability can be observed as the anterior-shift sign on MRI. This sign is useful when considering indications for periacetabular osteotomy in adult hip dysplasia.

Peri-prosthetic bone remodeling of hydroxyapatite-coated compaction short stem was not affected by stem alignment

Background

To improve implant survival through accelerated early bone remodeling during total hip arthroplasty (THA), hydroxyapatite (HA) is widely used as a bioactive coating, which is believed to enhance initial fixation by osseointegration. We aimed to investigate the relationship between stem insertion alignment and postoperative bone mineral density (BMD) changes in patients with full hydroxyapatite-coated (HA) compaction short stem and short tapered-wedge stem.

Methods

This retrospective cohort study enrolled 115 consecutive patients (115 joints) undergoing THA using the full HA compaction short (n = 59) and short tapered-wedge (n = 56) stems. Stem alignment, including anteversion, valgus, and anterior tilt were measured by a three-dimensional template using computed tomography data. Post-operative peri-prosthetic BMD was measured by dual-energy X-ray absorptiometry. The relationship between stem alignment and BMD changes in the stems was analyzed.

Results

Patterns of peri-prosthetic BMD changes were similar in both groups. Stem insertion alignments of anteversion, valgus, and anterior tilt were different between the two stem types. Stem alignment of valgus and anterior tilt did not affect peri-prosthetic BMD in either of the stem type. An absolute anteversion difference between stem anteversion and original canal anteversion caused significant peri-prosthetic BMD loss in Gruen zones one and seven in the tapered-wedge stem. However, stem alignment of absolute anteversion difference did not affect BMD changes in the HA compaction stem.

Conclusions

Peri-prosthetic bone remodeling remained unaffected by stem alignment after THA with the new short full HA compaction stem.

Robotic-arm assisted THA can achieve precise cup positioning in developmental dysplasia of the hip : a case control study

AIMS

This study aimed to evaluate the accuracy of implant placement with robotic-arm assisted total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH).

METHODS

The study analyzed a consecutive series of 69 patients who underwent robotic-arm assisted THA between September 2018 and December 2019. Of these, 30 patients had DDH and were classified according to the Crowe type. Acetabular component alignment and 3D positions were measured using pre- and postoperative CT data. The absolute differences of cup alignment and 3D position were compared between DDH and non-DDH patients. Moreover, these differences were analyzed in relation to the severity of DDH. The discrepancy of leg length and combined offset compared with contralateral hip were measured.

RESULTS

The mean values of absolute differences (postoperative CT-preoperative plan) were 1.7° (standard deviation (SD) 2.0) (inclination) and 2.5° (SD 2.1°) (anteversion) in DDH patients, and no significant differences were found between non-DDH and DDH patients. The mean absolute differences for 3D cup position were 1.1 mm (SD 1.0) (coronal plane) and 1.2 mm (SD 2.1) (axial plane) in DDH patients, and no significant differences were found between two groups. No significant difference was found either in cup alignment between postoperative CT and navigation record after cup screws or in the severity of DDH. Excellent restoration of leg length and combined offset were achieved in both groups.

CONCLUSION

We demonstrated that robotic-assisted THA may achieve precise cup positioning in DDH patients, and may be useful in those with severe DDH. Cite this article: Bone Joint Res 2021;10(10):629-638.

Postoperative excessive anterior acetabular coverage is associated with decrease in range of motion after periacetabular osteotomy

PURPOSE

The aim of this study was to evaluate the relationship between acetabular 3-dimensional (3D) alignment reorientation and clinical range of motion (ROM) after periacetabular osteotomy (PAO).

METHODS

50 patients (58 hips) with hip dysplasia participated in the study and underwent curved PAO. The pre- and postoperative 3D centre-edge (CE) angles and femoral anteversion were measured and compared with clinical outcomes, including postoperative ROM.

RESULTS

The correlation between pre- and postoperative acetabular coverage and postoperative ROM was evaluated. Postoperative abduction and internal rotation ROM were significantly associated with postoperative lateral CE angles (abduction; p < 0.001, internal rotation; p = 0.028); flexion and internal rotation ROM was significantly associated with postoperative anterior CE angles (flexion; p < 0.001, internal rotation; p = 0.028). Femoral anteversion was negatively correlated with postoperative abduction (p = 0.017) and external rotation (p = 0.047) ROM.

CONCLUSION

Postoperative anterior acetabular coverage may affect internal rotation ROM more than the lateral coverage. Therefore, the direction of acetabular reorientation should be carefully determined according to 3D alignment during PAO.

Total hip arthroplasty using a three-dimensional porous titanium acetabular cup: an examination of micromotion using subject-specific finite element analysis

Background

We investigated the mid-term clinical and radiological results of total hip arthroplasty (THA) using a three-dimensional (3D) porous titanium cup and analyzed the micromotion at the interface of the cup using subject-specific finite element (FE) analysis.

Methods

We evaluated 73 hips of 65 patients (6 men and 59 women; mean age at the time of surgery, 62.2 years; range, 45–86 years) who had undergone THA using a 3D porous titanium cup. Clinical evaluations were performed using the Japanese Orthopaedic Association (JOA) hip score system. We assessed the fixation of the acetabular component based on the presence of radiolucent lines and cup migration using anteroposterior radiographs. Subject-specific FE models were constructed from computed tomography data.

Results

The JOA score improved from a preoperative mean of 52.2 (range, 23–82) to a mean of 87.8 (range, 71–100) at the final follow-up. None of the patients underwent revisions during the follow-up period. Radiolucent lines were observed in 26 cases (35.6%) and frequently appeared at DeLee and Charnley Zone 3. Following the FE analysis, the micromotion at DeLee and Charnley Zone 3 was significantly larger than that at Zone 2. Furthermore, micromotion was large in the groups in which radiolucent lines appeared at Zone 3.

Conclusions

The mid-term clinical outcome of THA using a 3D porous titanium cup was excellent. However, radiolucent lines frequently appeared at DeLee and Charnley Zone 3. FE analysis indicated that micromotion was large at the same site, strongly suggesting that it contributes to the emergence of radiolucent lines. The 3D porous titanium cups are useful in THA, and with improvements focused on micromotion, we anticipate better long-term outcomes.

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

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.

Larger Acetabular Labrum Is Associated With Hip Dysplasia, Joint Incongruence, and Clinical Symptoms

PURPOSE

To evaluate the association of labral length with acetabular morphology and clinical symptoms.

METHODS

Patients treated at our hip joint clinic between January 2015 and December 2018 were retrospectively enrolled in the study. Our sample included patients who received a diagnosis of one or more of the following: hip labral tear, femoroacetabular impingement (FAI), and developmental dysplasia of the hip. Patients with osteoarthritis and/or osteonecrosis were excluded. Bilateral labral length was measured as the distance from the acetabular rim to the edge of the labrum at the level of the central coronal T1-weighted magnetic resonance imaging scan cross-referenced to the axial plane (3- to 9-o'clock position). The lateral center-edge angle (LCEA) and acetabular roof obliquity (ARO) were evaluated with plain radiographs. An LCEA of 25° or less was defined as developmental dysplasia of the hip, whereas a positive crossover sign in the presence of an LCEA of 30° or greater, an LCEA greater than 40°, or acetabular inclination lower 0° was defined as pincer FAI. An alpha angle greater than 50° or head-neck offset lower 8 mm was considered cam FAI. The severity of hip symptoms was evaluated bilaterally using the Japanese Orthopaedic Association pain scale, on which hips scoring full points (i.e., a perfect score) were defined as asymptomatic whereas hips with all other scores were considered symptomatic. We used simple linear regression to examine the correlations of labral length with the LCEA and ARO. Labral length was also compared according to patient hip symptom status using the Mann-Whitney U test.

RESULTS

The study included 102 patients (14 with bilateral symptoms and 88 with unilateral symptoms). Labral length was strongly correlated with the LCEA (r = -0.612, P < .001) and ARO (r = 0.635, P < .001). Additionally, patients with symptomatic hips had significantly larger labra (9.5 ± 3.0 mm) than those with asymptomatic hips (7.9 ± 2.1 mm, P = .004).

CONCLUSIONS

Acetabular labral length is significantly greater in dysplastic, irregularly congruent, symptomatic hips.

LEVEL OF EVIDENCE

Level Ⅳ, retrospective cross-sectional study.

Preoperative anterior coverage of the medial acetabulum can predict postoperative anterior coverage and range of motion after periacetabular osteotomy: a cohort study

BACKGROUND

We hypothesized that preoperative pelvic morphology may affect postoperative anterior coverage and postoperative clinical range of motion (ROM) leading to postoperative pincer type femoroacetabular impingement (FAI). The aim of this study was to evaluate the relationships between preoperative bone morphology and postoperative ROMs to prevent postoperative FAI after periacetabular osteotomy.

METHODS

Sixty-eight patients (71 hips) with hip dysplasia participated in this study and underwent curved PAO. The acetabular fragment was usually moved only by lateral rotation of the acetabulum, without intraoperative anterior or posterior rotation. The pre- and postoperative three-dimensional center-edge (CE) angles were measured and compared to the postoperative ROM.

RESULTS

Preoperative medial anterior CE angle was significantly associated with postoperative anterior CE angle, and the correlation coefficient of medial anterior CE and postoperative anterior CE was higher than the coefficient of preoperative anterior CE and postoperative anterior CE (preoperative anterior CE, rr = 0.27, p = 0.020; preoperative medial anterior CE, rr = 0.54, p < 0.001). Femoral anteversion correlated with postoperative internal rotation angle at 90° flexion (r = 0.32, p = 0.021). In multiple linear regressions, postoperative internal rotation angle at 90° flexion angle was significantly affected by both medial CE angle through the medial one fourth of femoral head and femoral anteversion.

CONCLUSIONS

Preoperative medial anterior acetabular coverage was associated with postoperative anterior acetabular coverage. Further, the combination with preoperative medial anterior acetabular coverage and femoral anteversion can predict postoperative internal rotation at 90° flexion. Therefore, the direction of acetabular reorientation should be carefully considered when the patients have high preoperative medial anterior CE angle and small femoral anteversion.

Predictors of Health-Related Quality of Life After Revision Total Hip Arthroplasty for Aseptic Loosening

BACKGROUND

Few studies have investigated the relationships between preoperative or intraoperative patient factors and postoperative quality of life (QOL) after revision total hip arthroplasty (THA). The aim of our study was to identify the predictors of QOL after revision THA for aseptic loosening.

MATERIALS AND METHODS

Fifty-one patients who underwent revision THA for aseptic loosening were included in the present study. Preoperative hip function was evaluated using the Japanese Orthopaedic Association (JOA) score. The patients' QOL after surgery was evaluated with EuroQol 5D (EQ-5D) assessment at the end of the 2-year follow-up. The patients were then divided into two groups: good QOL (score ≥ 0.6) and poor QOL (score < 0.6). Predictive factors (i.e., age, BMI, preoperative JOA score, and the degree of acetabular bone defect according to the Paprosky classification) were compared between both QOL groups. Furthermore, multiple linear regression was performed to assess independent factors affecting the QOL.

RESULTS

Significant differences between the good and poor QOL groups were identified for BMI, walking ability, and severity of acetabular bone defect (BMI: 21.5 ± 2.9 vs. 24.1 ± 4.3, P = 0.0331; walking ability: 11.5 ± 5.0 vs. 5.5 ± 4.9, P = 0.0058; acetabular bone defect: 44.4% vs. 81.0%, P = 0.0103). The walking ability independently affected the EQ-5D utility score.

CONCLUSIONS

The present study indicates that a higher BMI, lower walking ability, and more severe acetabular bone defect are predictors of lower QOL after revision THA for aseptic loosening. In particular, the walking ability was the only independent factor. Thus, surgeons should pay attention to the postoperative management of patients with these risk factors.

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.

Predicting acetabular growth in developmental dysplasia of the hip following open reduction after walking age

BACKGROUND

Acetabular dysplasia of the hip following open reduction can complicate the treatment of developmental dysplasia of the hip (DDH). The purposes of this retrospective study were to investigate the long-term results of open reduction performed via an extensive anterolateral approach for DDH after walking age and to predict acetabular development using postoperative radiographs and arthrograms.

METHODS

From 1973 to 2001, we performed open reduction for 131 hips in 119 pediatric patients with DDH after failed closed reduction. Of these, 85 hips of 73 patients who underwent arthrography at 5 years old were followed-up radiologically until skeletal maturity. Mean age at the time of surgery was 17 ± 4.6 months (range, 10-33 months), and mean age at final survey was 19 ± 5.7 years (range, 14-33 years). Mean follow-up time was 17.7 ± 5.8 years (range, 13-32 years). Groups with satisfactory outcomes (66 hips) and unsatisfactory outcomes (19 hips) according to the Severin classification were compared. Factors predicting acetabular development were identified using univariate and multiple logistic analyses.

RESULTS

Univariate analysis showed a significant between-group difference in acetabular index (AI) at 2 months postoperatively, and in center-edge (CE) angle, cartilaginous AI (CAI), and cartilaginous CE angle at 5 years old (p < 0.05 each). In multiple logistic regression analysis, CAI at 5 years old represented a predictor of acetabular development after open reduction for DDH (odds ratio, 1.81; 95% confidence interval (CI), 1.04-3.13; p < 0.05). Area under the receiver operating characteristic curve for CAI at 5 years old was 0.93 (95%CI, 0.85-1.0), and the optimal cut-off was 10° (81.8% sensitivity, 92% specificity).

CONCLUSIONS

A CAI ≥10° on hip arthrograms at 5 years old may offer a useful indicator of the need for corrective surgery following open reduction after walking age.

Radiographic Progression of Osteoarthritis after Rotational Acetabular Osteotomy: Minimum 10-Year Follow-up Outcome According to the Tönnis Grade

Background

Although satisfactory mid- to long-term results of rotational acetabular osteotomy for early osteoarthritis secondary to acetabular dysplasia have been reported, there is still controversy about the long-term effects of this surgery in more advanced osteoarthritis. The purpose of this study was to investigate the radiographic progression of osteoarthritic changes after rotational acetabular osteotomy in acetabular dysplasia according to the preoperative Tönnis grade and evaluate its effects after minimum 10-year follow-up.

Methods

We performed 71 consecutive rotational acetabular osteotomies in 64 patients with symptomatic acetabular dysplasia between November 1984 and April 2005. Of these, 46 hips (four hips with Tönnis grade 0, 30 with grade 1, and 12 with grade 2) whose clinical and radiographic findings were available after minimum 10-year follow-up were evaluated in this study. The mean age at the time of surgery was 39.0 years (range, 18 to 62 years) and the average follow-up duration was 17.3 years (range, 10.0 to 27.7 years). Clinical and radiographic evaluations were performed according to the preoperative Tönnis grade.

Results

The average Harris hip score improved from 71.8 (range, 58 to 89) to 85.1 (range, 62 to 98). The radiographic parameters also improved in all Tönnis grades after the index surgery. Although the improvement of radiographic parameters was not different between preoperative Tönnis grades, the incidence of osteoarthritic progression was significantly different between grades (zero in Tönnis grade 0, four in Tönnis grade 1, and 10 in Tönnis grade 2; p < 0.001). The mean age at the time of surgery was also significantly older in osteoarthritic progression patients (p < 0.002). Kaplan-Meier survivorship analysis, with radiographic progression of osteoarthritis as the endpoint, predicted a 10-year survival rate of 100% in Tönnis grade 0, 85.7% in Tönnis grade 1, and 14.3% in Tönnis grade 2 (p < 0.001).

Conclusions

The outcome of rotational acetabular osteotomy in most hips with Tönnis grade 0 and 1 was satisfactory after an average of 17 years of follow-up. The incidence of osteoarthritic progression was higher in Tönnis grade 2 and older age. Our results support that early joint preserving procedure is essential in the case of symptomatic dysplastic hips.

Hemi-pelvic slope is correlated with the acetabular depth in adults-a radiological study

OBJECTIVE

The purpose of this study was to determine if there is an anatomic relationship between pelvic geometry and acetabular depth.

MATERIALS AND METHODS

One hundred and fifty-one anteroposterior pelvic radiographs (157 hip joints) were selected and analyzed in a retrospective fashion. Six parameters, including iliac offset, ischial offset, acetabular offset, pelvic height, center-edge (CE) angle of Wiberg, and acetabular index (AI) angle of Tönnis were measured for each of the hip joints. Based on the defined variables, three formulas (formulas 1, 2, and 3) were calculated to represent the hemi-pelvis slope.

RESULTS

There was a strong relationship between the hemi-pelvis slope and probability of acetabular dysplasia. Wider upper pelvis was associated with deeper acetabulum and wider lower pelvis was associated with dysplastic acetabulum.

CONCLUSIONS

Pelvic anatomic dimensions and the relationship between them are strongly correlated with hip dysplasia indices. Dysplastic hips tend to be found in pelvises with lower slope (low width of the upper pelvis at the level of iliac crest and high width of the lower part at the level of ischium).

Computer-assisted surgery prevents complications during peri-acetabular osteotomy

PURPOSE

The aim of study is to evaluate the accuracy of a navigation system during curved peri-acetabular osteotomy (CPO).

METHODS

Forty-seven patients (53 hips) with hip dysplasia were enrolled and underwent CPO with or without navigation during surgery. Clinical and radiographical evaluations were performed and compared between the navigation group and non-navigation group, post-operatively.

RESULTS

The clinical outcomes were not significantly different between the navigation and non-navigation groups. Furthermore, post-operative reorientation of the acetabular fragment was similar between the navigation and non-navigation groups. However, the discrepancy between the pre-operative planning line and post-operative osteotomy line was significantly improved in the navigation group compared with that in the non-navigation group (p < 0.05). Further, the complication rate was significantly improved in the navigation group (p < 0.001).

CONCLUSION

The accuracy of the osteotomy's position was significantly improved by using the navigation. Therefore, the use of navigation during peri-acetabular osteotomy can avoid complications.

Risk factor analysis for postoperative complications requiring revision surgery after transtrochanteric rotational osteotomy for osteonecrosis of the femoral head

BACKGROUND

This study investigated the risk factors for postoperative complications requiring revision surgery within 3 years after transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH).

METHODS

We reviewed 127 patients (147 hips) who underwent TRO (anterior or posterior rotational osteotomy) for ONFH between January 2002 and December 2014. Two patients were lost to follow-up, and five patients with progression of femoral head collapse requiring a salvage procedure such as total hip arthroplasty within 3 years after TRO were excluded. The better hip in patients treated bilaterally was also excluded (n = 20) to avoid duplication of patient demographics, leaving 120 hips (120 patients) for the analysis. We reviewed the medical records of each patient to screen for postoperative complications that required revision surgery within 3 years after surgery, recording the patient's age, sex, body mass index, surgical side, condition of the contralateral hip, previous alcohol intake, previous alcohol abuse, previous corticosteroid use, perioperative corticosteroid use, smoking status, preoperative stage and type of ONFH, preoperative activity level, and preoperative and final follow-up Japanese Orthopaedic Association scores. Differences between cases with and without complications were analyzed.

RESULTS

Eleven (9.2%) cases showed postoperative complications that required revision surgery. The most common complication was deep infection (n = 5), followed by nonunion of the greater trochanter (n = 3), nonunion of the intertrochanteric osteotomy site (n = 2), and femoral head fracture (n = 1). The multivariate analysis showed an independent association between previous alcohol abuse and postoperative complications (odds ratio, 13.5).

CONCLUSION

A correlation might exist between alcohol abuse and complications following a TRO procedure.

Risk factors for failure of revision total hip arthroplasty using a Kerboull-type acetabular reinforcement device

Background

The present study aimed to identify the risk factors associated with revision total hip arthroplasty (THA) failure using a Kerboull-type (KT) plate.

Methods

We analyzed 77 revision THAs using cemented acetabular components with a KT plate for aseptic loosening between May 2000 and March 2012. We examined the association of bone graft type, acetabular bone defects, age at the time of surgery, preoperative Japanese Orthopaedic Association (JOA) score, postoperative JOA hip score, and body mass index, with radiographic failure as the outcome.

Results

The 7.4-year radiographic failure survival rate was 81.6%. The survival rate was significantly different between the beta-tricalcium phosphate (β-TCP) group and the bulk allograft group (p = 0.019). The survival curves were also significantly different between the β-TCP group and bulk allograft group (p = 0.036). American Academy of Orthopaedic Surgeons type IV was significantly associated with radiographic failure (odds ratio [OR]: 15.5, 95% confidence interval [CI]: 1.4–175.4; p = 0.032).

Conclusions

The midterm outcomes of revision THA indicate that type of bone graft and bone defect size may affect radiographic survival rate when using a KT plate.

Dynamic femoral head translations in dysplastic hips

BACKGROUND

Developmental dysplasia of the hip is an important disease leading to osteoarthritis. Recently, researchers have focused on hip instability as a potentially important dynamic factor for osteoarthritis, but the detailed kinematics of dysplastic hips during weight-bearing gait have not been reported. The purpose of this research is to contrast femoral translation in contralateral healthy hips and dysplastic hips during weight-bearing stepping.

METHODS

Twelve dysplastic hips and eight healthy hips were investigated. Hip joint kinematics were analyzed using 3D-2D model-image registration with dynamic fluoroscopic images of each hip during a stepping-in-place activity. Femoral translation relative to the acetabular center was quantified as instability.

FINDINGS

Total femoral head translations were significantly different between dysplastic and contralateral healthy hips. Mean translation was 1.0mm in dysplastic hips and 0.4mm in contralateral healthy hips during swing-phase, and consisted of inferior translation during early swing phase with a complementary superior translation just before foot strike. Total femoral translation was significantly correlated to several radiographic indices of hip dysplasia.

INTERPRETATION

Superior translations of the femur during the end of swing phase may result in altered articular contact mechanics, abnormal stresses on the labrum and lost lubricant sealing. All of these factors may contribute to joint degeneration and osteoarthritis in dysplastic hips.

Multiple Revision Surgeries and Acetabular Bone Defect Size May Predict Daily Activity After Revision Total Hip Arthroplasty

BACKGROUND

We identified preoperative predictors and size of acetabular bone defects for poor return to daily activity after revision total hip arthroplasty.

METHODS

Our analysis was based on outcomes of 140 cases of revision total hip arthroplasty, performed for any reason between May 2001 and March 2013. The Japanese Orthopaedic Association (JOA) score and body mass index (BMI) measured preoperatively, and the University of California Los Angeles (UCLA) activity score and JOA score measured at the 2-year follow-up were evaluated. Acetabular bone defects were classified according to the American Academy of Orthopaedic Surgeons grading system, with further classification of the location and severity of each acetabular bone defect. We compared preoperative clinical factors and postoperative clinical outcomes statistically.

RESULTS

We found a significant association between the number of revision surgeries and worse postoperative JOA scores and UCLA activity scores. There were significant differences in postoperative JOA scores and UCLA activity scores between patients with partial and global acetabular bone defects.

CONCLUSION

Multiple revision surgeries and the size of the acetabular bone defect were predictors of both poorer clinical outcome and greater restriction in postoperative daily activities. Closer attention to the postoperative management of patients with a lower preoperative status is warranted.

Intraoperative Arthrogram Predicts Residual Dysplasia after Successful Closed Reduction of DDH

OBJECTIVE

To determine the incidence of residual dysplasia after closed reduction (CR) of developmental dysplasia of the hip (DDH) and assess correlations between quality of arthrogram-guided CR and residual dysplasia using a new intraoperative radiographic criterion.

METHODS

Data of a consecutive series of 126 patients with DDH in 139 hips treated at our institution by arthrogram-guided CR from March 2006 to June 2013 were reviewed in this retrospective study. There were 23 boys and 103 girls with 88 affected left hips and 51 right hips. The average age at closed reduction was 14 months (range, 7-19 months) and average duration of follow-up 36 months (range, 24-100 months). Femoral head coverage (FHC) and arthrography type (A/B/C) on best reduced arthrographic images, acetabular index (AI) and Wiberg Center-Edge (CE) angle on anteroposterior (AP) pelvis radiograph at latest follow-up were measured. Residual hip dysplasia was determined according to the Harcke acetabular dysplasia radiographic standard. Patients were divided into non-late acetabular dysplasia (non-LACD) and late acetabular dysplasia (LACD) groups according to final results and age at reduction, sex and side compared between these two groups. Correlations between FHC and arthrography type and residual hip dysplasia were analyzed. Multiple logistic regression analysis was used to analyze sex, AI at CR, arthrography type and FHC with LACD. Receiver operating characteristic (ROC) curve analysis was used to determine the cutoff value for FHC.

RESULTS

Forty-five of 139 hips (32.4%) had residual hip dysplasia. Avascular necrosis of the femoral head occurred in 11 hips (7.9%), nine of which had acetabular dysplasia. There were no significant differences between the two groups in age at reduction, sex or side. FHC differed significantly between the two groups (51.2% ± 15.3% vs . 28.5% ± 15.9%, t = 4.718, P = 0.000). A significantly greater percentage of the arthrography Type C group than Type A and B groups had LACD (χ(2) = 17.170, P = 0.017). According to multiple logistic regression analysis, FHC was the only prognostic factor for LACD. There was a clear cutoff value for FHC (30%), under which 81.8% hips were determined as having LACD according to ROC curve analysis.

CONCLUSIONS

Intraoperative arthrogram-determined FHC is an alternative predictor of residual hip dysplasia after CR of DDH and FHC ≤30% can be considered the criterion for unacceptable reduction.

Factors Associated With Severity of Intra-articular Lesions in Patients With Severe Hip Dysplasia

PURPOSE

To identify demographic and morphologic factors associated with the severity of intra-articular lesions in patients with severe hip dysplasia.

METHODS

One hundred twenty-one patients (134 hips) with symptomatic hip dysplasia were retrospectively reviewed. The cartilage and labral lesions were scored according to the Outerbridge and the original classification systems, respectively. The association of the cartilage and labrum scores with patient demographics (age, gender, body mass index, bilateral hip dysplasia, and treatment history for developmental hip dislocation) and morphologic factors (the lateral center-edge angle, Sharp angle, acetabular index, acetabular head index, acetabular depth ratio, Shenton line disruption, roundness index of the femoral head, and femoral neck shaft angle) were determined using a multiple linear regression analysis.

RESULTS

The cartilage and labral scores were significantly associated with radiographic osteoarthritis; however, these scores showed wide distribution among hips with equivalent degrees of radiographic osteoarthritis. Age (38.4 ± 12.8 years) (P < .001), lateral center-edge angle (0.2 ± 9.0°) (P = .014), acetabular head index (54.4 ± 9.1%) (P = .001), and the roundness index of the femoral head (55.6 ± 4.6%) (P = .022) were identified as independent factors associated with the cartilage score. Age (P < .001), having a medical history of developmental hip dislocation (P = .002), acetabular index (27.8 ± 6.8°) (P = .011), and the roundness index of the femoral head (P = .022) were identified as independent factors associated with the labral score.

CONCLUSIONS

Our findings suggest that the morphologic factors responsible for severe intra-articular lesions differ for cartilage degeneration and labral tears in patients with severe hip dysplasia. Decreased acetabular coverage of the femoral head was responsible for cartilage degeneration severity, whereas an increased acetabular index was responsible for labral tear severity.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Surgical Techniques of Eccentric Rotational Acetabular Osteotomy

Introduction

This report describes the operative indications and essential techniques of eccentric rotational acetabular osteotomy for hip dysplasia in patients with either pre-osteoarthritis, early arthritis, or in some cases even advanced osteoarthritis of the hip.

Step 1: Patient Positioning

An accurate lateral decubitus position of the pelvis is important.

Step 2: Skin Incision

Make a bikini skin incision and elevate the skin flap.

Step 3: Transtrochanteric Approach

Make a Y-shaped incision, retract the innominate fossa, and detach the greater trochanter with an oscillating saw.

Step 4: Deep Dissection to Mark the Osteotomy Lines

Partially release and divide the rectus femoris, detach the iliacus, and retract the iliopsoas.

Step 5: Osteotomy of Ilium and Ischium

It is essential to use an osteotomy guide to perform an accurate spherical osteotomy.

Step 6: Osteotomy of the Pubic Bone

The osteotomy of the pubic bone is technically demanding.

Step 7: Reorientation of the Acetabular Fragment

The acetabular fragment can be rotated to the intended position as determined by the preoperative planning.

Step 8: Reattachment of the Greater Trochanter

Fix the greater trochanter with two AO cancellous screws.

Step 9: Postoperative Care

Walking with a walker and partial weight-bearing begins one day after surgery, and full weight-bearing starts at two months postoperatively.

Results

The clinical and radiographic outcomes in the first 126 consecutive patients (132 hips) who had undergone eccentric rotational acetabular osteotomy at our institution were retrospectively assessed.

Indications

Contraindications

Pitfalls & Challenges

Long term results with the interlocking uncemented long stem in revision hip arthroplasty: a mean 15-year follow-up

Stem fixation is difficult to achieve in severe proximal bone loss in revision hip surgery. In this study, we sought to present the results of distally-locked stem with screws (HUCKESTEP HIP stem) in 21 revision hips with mean follow-up period of 15 years. The preoperative mean Japanese Orthopaedic Association hip score had improved from 54 to 75 points. Further revisions were required for 2 stems, in one because of infection and the other because of screws fracture and subsidence. With removal of the stem for any reason as an end-point, the cumulative survival at 15 years was 90.4%. While this study had small number, the use of this interlocking stem for revision hips with extensive proximal bone defects provided satisfactory 15-year clinical and radiographic results.

Mid-term clinical and radiographic outcomes of porous tantalum modular acetabular components for hip dysplasia

It is still challenging to perform successful cementless cup fixation during total hip arthroplasty for hip dysplasia. In this multicenter study we evaluated the clinical results of porous tantalum modular acetabular cups (TM cups) in 45 dysplastic hips with a mean follow-up period of 9.8 years. The mean Japanese Orthopaedic Association hip score improved from 48.2 preoperatively to 92.1 at the most recent follow-up. All of the cups were radiographically stable with no evidence of progressive radiolucencies or osteolysis regardless of bone grafting. Sixteen hips with bone grafts showed the integration of grafted bone without any radiolucencies. There were no revisions of TM cups. The use of TM cups for dysplastic hips provided satisfactory 10-year clinical and radiographic results.

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.

Eccentric rotational acetabular osteotomy for acetabular dysplasia and osteoarthritis: follow-up at a mean duration of twenty years

BACKGROUND

The aim of the eccentric rotational acetabular osteotomy is to correct the deficient acetabular coverage in the dysplastic hip in order to limit the development of secondary osteoarthritis. The purpose of this study was to investigate the results in patients managed with an eccentric rotational acetabular osteotomy after a mean of twenty years.

METHODS

The clinical and radiographic outcomes for the first 126 consecutive patients (132 hips) who underwent an eccentric rotational acetabular osteotomy at our institution were retrospectively evaluated. One hundred and twenty-four patients (130 hips) were evaluated; 117 were women (123 hips). The mean patient age was thirty-seven years (range, fifteen to fifty-nine years) at the time of surgery, and the average duration of follow-up was twenty years. Twenty-three hips in twenty-two patients were also treated with intertrochanteric valgus osteotomy at the time of the eccentric rotational acetabular osteotomy to further improve joint congruency.

RESULTS

The mean preoperative Harris hip score of 70 points (range, 51 to 90 points) improved to a mean of 88 points (range, 35 to 100 points) at the final follow-up. Thirty hips had a fair clinical outcome (Harris hip score, <80 points). In seventeen hips, the eccentric rotational acetabular osteotomy was converted to a total hip arthroplasty. The cumulative survivorship at fifteen years and at the final follow-up at twenty-three years was 97% and 80%, respectively. Four factors led to a poor outcome: a small (≤2.0-mm) preoperative minimum joint space, joint incongruence, simultaneous intertrochanteric valgus osteotomy, and lateral subluxation of the femoral head postoperatively.

CONCLUSIONS

Eccentric rotational acetabular osteotomy is an effective surgical procedure for treating symptomatic dysplastic hips before, and in the early stages of, osteoarthritis. The majority of patients maintained excellent or good native hip function at a mean of twenty years after surgery.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Surgical implications for residual subluxation after closed reduction for developmental dislocation of the hip: a long-term follow-up

OBJECTIVE

Untreated residual subluxation after early closed reduction for developmental dislocation of the hip (DDH) leads to early degenerative osteoarthritis. The aim of our study was to investigate the role of early surgical timing and its indications.

METHODS

Thirty-six patients (48 hips) with untreated residual subluxation after closed reduction who had serial follow-up radiographs until they had reached skeletal maturity were retrospectively reviewed. The average age at closed reduction was 1.6 years and at the last follow-up 13.8 years. The last radiographs were evaluated according to the Severin classification: Severin grades I and II were defined as satisfactory and Severin grades III and IV as unsatisfactory. Several measurements of the acetabular index (AI), Reimer's index (RI), center edge angle of Wiberg (CE angle) and orientation of the sourcil of the acetabulum were evaluated.

RESULTS

The satisfactory group comprised 18/48 hips (37%), whereas the unsatisfactory group comprised 30/48 hips (63%). The average RI in the unsatisfactory group was significantly worse than that in the satisfactory group at the age of ≥3-4 years, as was the average CE angle at the age of ≥4-5 years and AI at the age of ≥5-6 years. As remodeling occurs over time, some subluxations diagnosed at age of 2-3 years developed into normal hips. At 3-4 years, 42 hips were still subluxed; 71% of these had unsatisfactory final Severin grades. At 4-5 years, 30 hips were still subluxed; 87% of these had unsatisfactory Severin grades (III and IV). Very little remodeling after the age of 5 years. Eighteen/18 hips with (34.4% ± 4.5% vs 43.0% ± 4.6%, P < 0.00) RI >38% at the age of 3-4 years fell into the unsatisfactory (21.0° ± 5.5° vs 10.6° ± 5.2°, P < 0.01) group. In addition, 26/30 hips with RI >33% at the age of 4-5 years were in the unsatisfactory group, as were 26/26 hips with upward sourcil orientation.

CONCLUSION

To avoid early osteoarthritis, surgery correction of residual subluxation is recommended when the RI >38% at the age of 3-4 years or the RI >33% with the sourcil upward at the age of 4-5 years.

The role of experience level in radiographic evaluation of femoroacetabular impingement and acetabular dysplasia

Accurate radiographic interpretation is essential for properly diagnosing the etiology of pre-arthritic hip pain such as femoroacetabular impingement (FAI) and acetabular dysplasia (AD); however, radiographic interpretation can be significantly influenced by the observer’s experience level. This study assesses the accuracy and inter- and intraobserver reliability in the radiographic evaluation of FAI and AD based on experience level. Fifty-five patients diagnosed with FAI, AD or normal hip morphology were identified from the principal investigator’s institutional database. Four observers performed an independent and blinded radiographic review, assessing 14 radiographic parameters and an interpretation of a final diagnosis. A second radiographic evaluation of 20 preselected cases was completed 6 weeks after the initial reading to assess intraobserver reliability. Inter- and intraobserver reliability was determined using Cohen’s Kappa Coefficient (κ) and intraclass correlation coefficient (ICC) for continuous parameters in a four-rater design. Interobserver reliability was highest across experience levels for lateral centre edge angle (ICC = 0.92) and alpha angle (ICC = 0.90) and lowest (κ < 0.3, ICC < 0.3) for joint congruency and detection of herniation pits. Intraobserver reliability was highest for acetabular depth (κ = 0.89) and alpha angle (ICC = 0.80) and lowest for head–neck offset ratio and Tönnis grade. Final diagnosis was consistent with the original blinded clinical diagnosis 75–84% of the time across four experience levels. The attending orthopaedic hip surgeon demonstrated greatest diagnostic sensitivity but lowest specificity for making an accurate radiographic diagnosis. Subjective parameters must be redefined, and objective parameters must be further developed to improve the reliability of accurately diagnosing FAI or AD.

A replication study for the association of rs726252 in PAPPA2 with developmental dysplasia of the hip in Chinese Han population

Developmental dysplasia of the hip (DDH) is a common developmental hip disorder, which ranges from mild acetabulum malformation to irreducible hip dislocation. A previous study suggested a significant association of pregnancy-associated plasma protein-A2 (PAPPA2) with DDH susceptibility in Chinese Han population. But with the consideration of the sample size, the association was still debatable. To confirm the association of the reported single nucleotide polymorphism (SNP) in PAPPA2, rs726252 with DDH, we conducted a case-control study in a larger number of subjects. We genotyped rs726252 in 697 DDH subjects and 707 control subjects by TaqMan assay. The association between this SNP and DDH was evaluated statistically. No significant difference was found in any comparison of genotype distribution nor allele frequency between cases and controls. Our replication study indicated that the association between rs726252 and DDH in Chinese Han population was debatable. The association between PAPPA2 and DDH should be evaluated by additional studies.

Triple pelvic osteotomy: Report of our mid-term results and review of literature

A wide variety of pelvic osteotomies have been developed for the treatment of developmental dysplasia of the hip (DDH). In the present paper, we present a detailed review of previous studies of triple osteotomy as an alternative treatment for DDH. We also report our experience treating 6 adult cases of DDH by triple osteotomy in order to highlight the various aspects of this procedure.The mean age of our patients was 31.2 years with a mean follow-up period of 6 years. We assessed range of motion, center-edge angle, acetabular index angle, Sharp angle, acetabulum head index, head lateralization index, Japanese Orthopedic Association score, Harris hip score, patient satisfaction, and the difference between lower limb lengths before and after the procedure. At final follow-up, clinical scores were significantly improved and radiographic parameters also showed good correction of acetabulum.

Less invasive rotational acetabular osteotomy for hip dysplasia

BACKGROUND

Broad dissection with a long skin incision and detachment of the gluteus medius muscle performed for rotational acetabular osteotomy (RAO) can result in weakness in abduction strength of the hip. We use a surgical procedure for RAO that minimizes operative invasion of soft tissue and reduces incision length compared with conventional procedures.

QUESTIONS/PURPOSES

We evaluated the clinical results of this less-invasive RAO comparing it with the more-invasive prior procedure with respect to improvement in clinical hip scores and radiographic coverage and overall hip survival after the procedure.

METHODS

In this less-invasive exposure, the medial gluteus muscle is retracted to expose the ilium without detachment from the iliac crest. Similarly, the rectus femoris muscle tendon is retracted, not excised. The lateral part of the osteotomized ilium is cut to form the bone graft instead of harvesting it from the outer cortical bone of the ilium. Between 2000 and 2009, 62 patients (71 hips) underwent this procedure. Twenty-eight hips had early-stage osteoarthritis and 43 had advanced-stage osteoarthritis. Mean patient age was 40 years at the time of surgery. We evaluated improvement in hip scores (Merle d'Aubigné-Postel, Japanese Orthopaedic Association) and radiographic appearance (lateral center-edge angle, Sharp's angle, acetabular head index [AHI]). Kaplan-Meier survivorship analysis was performed. Mean followup was 5 years (range, 2.0-10.4 years).

RESULTS

Clinical hip scores improved postoperatively. On average, lateral center-edge angle, Sharp's angle, and AHI improved by 38°, 11°, and 42%, respectively. Predicted 10-year survival rates were 100% and 72% for hips with early- and advanced-stage osteoarthritis, respectively.

CONCLUSIONS

In hips with early-stage osteoarthritis treated by this less-invasive approach, no progression of osteoarthritis was documented and Trendelenburg gait was avoided. However, further investigation is necessary for hips with advanced-stage osteoarthritis.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Primary total hip arthroplasty with a spongy metal surface acetabular component for hip dysplasia

We evaluated the clinical and radiographic results of primary total hip arthroplasty for 81 dysplastic hips (71 patients) using cementless Spongiosa Metal II cups (ESKA Implants, Lübeck, Germany). The mean follow-up period was 6.4 years (minimum 5 years), and the preoperative mean Japanese Orthopaedic Association hip score had improved from 45.2 to 87.4 points at the latest follow-up. The radiographic outcome was no aseptic loosening in all 81 hips. The hip center was located significantly more superior than in the contralateral normal hip in 45 patients, but the difference was less than 10 mm; however, there was no significant difference in the lateral position of the hip center. The use of a Spongiosa Metal II cup for dysplastic hips provided satisfactory 5- to 10-year clinical and radiographic results.

Do fluoroscopy and postoperative radiographs correlate for periacetabular osteotomy corrections?

BACKGROUND

The Bernese periacetabular osteotomy (PAO) can relieve pain and restore function in patients with symptomatic acetabular dysplasia. Accurate acetabular correction is fundamental to achieving these clinical goals and presumably enhancing survivorship of the reconstruction. Fluoroscopy is used by some surgeons to assess intraoperative acetabular correction but it is unclear whether the features observed by fluoroscopy accurately reflect those on postoperative radiographs.

QUESTIONS/PURPOSES

We therefore determined whether the parameters of acetabular correction of PAO correlated on intraoperative fluoroscopic imaging and postoperative radiography.

METHODS

We retrospectively reviewed the imaging of 48 patients (50 hips) who underwent PAO. Intraoperative fluoroscopic AP and false profile images were obtained after final PAO correction. The intraoperative deformity correction as measured on the two fluoroscopy views was compared with the correction determined with postoperative standing plain AP pelvis and false profile radiographs using common measurements of acetabular position.

RESULTS

Of all radiographic parameters, lateral center-edge angle had the highest correlation between intraoperative fluoroscopy and the postoperative radiograph with an intraclass correlation coefficient (ICC) of 0.80 (0.68-0.88). Similarly, acetabular inclination and anterior center-edge angle also correlated with ICCs of 0.76 (0.61-0.85) and 0.71 (0.54-0.82), respectively. Extrusion index and medial offset distance had lower correlations with ICCs of 0.66 (0.46-0.79) and 0.46 (0.21-0.65), respectively.

CONCLUSIONS

Intraoperative fluoroscopic assessment of PAO correction correlated with that from the postoperative radiographic assessment. Measurement of lateral center-edge angle shows the highest correlation with the fewest outliers. Acetabular inclination and anterior center-edge angle also correlated; extrusion index and medial offset distance should be used with more caution.

Hydroxyapatite block for reconstruction of severe dysplasia or acetabular bone defects in total hip arthroplasty: operative technique and clinical outcome

Fourteen hips in 14 patients (all female; average age, 64 years) with severe bone defects due to developmental dysplasia of the hip or migration of the socket were treated with hydroxyapatite block with impacted morselized bone graft in conjunction with a cemented socket. All patients were followed clinically in a prospective fashion, and radiographs were analyzed retrospectively. One initial patient had 17-year follow-up, whereas the remaining 13 patients had follow-up between 4 and 6.5 years. No acetabular components were revised, including the socket of a 17-year postoperative case that remains rigidly fixed and supported by the graft and hydroxyapatite block with only mild polyethylene wear and minor osteolysis. Osteointegration and good clinical outcome were achieved in all cases by reconstruction with this technique in total hip arthroplasty.

Residual hip dysplasia as a risk factor for osteoarthritis in 45 years follow-up of late-detected hip dislocation

PURPOSE

The aim of the study was to assess the role of residual hip dysplasia as a risk factor for osteoarthritis (OA) in developmental dysplasia of the hip (DDH).

METHODS

Fifty-one patients (60 hips) with late-detected DDH were studied. Reduction had been performed at a mean age of 19 months (range 4-65 months). On radiographs at age 8-10 years, at skeletal maturity, and at long-term follow-up, femoral head coverage was assessed using the migration percentage (MP) and centre-edge (CE) angle. OA was diagnosed if the minimum joint space width of the upper part of the joint was <2.0 mm.

RESULTS

The mean age at the last follow-up was 45 years (range 43-49 years) in patients who had not undergone total hip replacement (THR). Ten patients had developed OA and eight of them had undergone THR at a mean age of 40 years (range 32-47 years). There was a clear association between OA and residual hip dysplasia. At the last follow-up, 37 hips had normal CE angles (20° or higher) and OA had developed in only two of them (5%; 95% confidence interval [CI] 1-18%). Hip dysplasia without subluxation (CE angle 10-19°) was seen in 18 hips, of which 14 hips had good outcome and four had OA (22%; 95% CI 6-48%). Subluxation occurred in five hips, of which one had a good long-term outcome and four had OA (80%; 95% CI 28-99%). In patients without late reconstructive surgery, MP increased from the age of 10 years to skeletal maturity; thereafter, no significant change occurred. The CE angle did not change significantly between the age of 10 years and the last follow-up.

CONCLUSION

Hip dysplasia without subluxation has a relatively good long-term prognosis. Subluxation is a risk factor for osteoarthritis. Thus, children with MP above 33% and CE angle under 10° should be evaluated for reconstructive surgery in order to improve the long-term outcome.

The epidemiology and demographics of hip dysplasia

The etiology of developmental dysplasia of the hip (DDH) is unknown. There are many insights, however, from epidemiologic/demographic information. A systematic medical literature review regarding DDH was performed. There is a predominance of left-sided (64.0%) and unilateral disease (63.4%). The incidence per 1000 live births ranges from 0.06 in Africans in Africa to 76.1 in Native Americans. There is significant variability in incidence within each racial group by geographic location. The incidence of clinical neonatal hip instability at birth ranges from 0.4 in Africans to 61.7 in Polish Caucasians. Predictors of DDH are breech presentation, positive family history, and gender (female). Children born premature, with low birth weights, or to multifetal pregnancies are somewhat protected from DDH. Certain HLA A, B, and D types demonstrate an increase in DDH. Chromosome 17q21 is strongly associated with DDH. Ligamentous laxity and abnormalities in collagen metabolism, estrogen metabolism, and pregnancy-associated pelvic instability are well-described associations with DDH. Many studies demonstrate an increase of DDH in the winter, both in the northern and southern hemispheres. Swaddling is strongly associated with DDH. Amniocentesis, premature labor, and massive radiation exposure may increase the risk of DDH. Associated conditions are congenital muscular torticollis and congenital foot deformities. The opposite hip is frequently abnormal when using rigorous radiographic assessments. The role of acetabular dysplasia and adult hip osteoarthritis is complex. Archeological studies demonstrate that the epidemiology of DDH may be changing.

Preliminary application of computer-assisted patient-specific acetabular navigational template for total hip arthroplasty in adult single development dysplasia of the hip

BACKGROUND

The considerable variation in anatomical abnormalities of hip joints associated with different types of developmental dysplasia of hip (DDH) makes reconstruction in total hip arthroplasty (THA) difficult. It is desirable to create patient-specific designs for THA procedures. In the cases of adult single DDH, an accuracy-improved method has been developed for acetabular cup prosthesis implantation of hip arthroplasty.

METHODS

From October 2007 to November 2008, 22 patients with single DDH (according to the Crowe standard, all dysplasia hips were classified as type I) were scanned with spiral CT pre-operatively. These patients scheduled for THA were randomly assigned to undergo either conventional THA (control group, n = 11) or navigation template implantation (NT group, n = 11). In the NT group, three-dimensional (3D) CT pelvis image data were transferred to a computer workstation and 3D models of the hip were reconstructed using the Mimics software. The 3D models were then processed by the Imageware software. In brief, a template that best fitted the location and shape of the acetabular cup was 'reversely' built from the 3D model, the rotation centre of the pathological hip determined by mirroring that of the healthy site, and a guiding hole in the template was then designed. The navigational templates were manufactured using a rapid prototyping machine. These navigation templates guide acetabular component placement.

RESULTS

Based on the predetermined abduction angle 45° and anteversion angle 18°, after 1 year follow-up, the NT group showed significantly smaller differences (1.6° ± 0.4°, 1.9° ± 1.1°) from the predetermined angles than those in the control group (5.8° ± 2.9°, 3.9° ± 2.5°) (P < 0.05).

CONCLUSIONS

The template designs facilitated accurate placement of acetabular components in dysplasia of acetabulum. The hip's center of rotation in DDH could be established using computer-aided design, which provides a useful method for the accurate location of prosthesis with a low cost-performance ratio without excessive technical workload on the surgical team.

Measuring acetabular dysplasia in plain radiographs

BACKGROUND

Several radiologic parameters have been used to qualify an acetabular coverage in studies determining whether an association exists between acetabular dysplasia and osteoarthritis of hip. However, it is not known which parameter is optimum for these epidemiologic studies. We evaluate the reliability, validity, and robustness of the radiologic parameters of acetabular coverage used in these studies.

METHODS

Center-edge angle (CEA), acetabular depth (AD), acetabular angle (AA), acetabular roof obliquity (ARO), and roof angle (RA) were evaluated. The components of intra- and interobserver reliability were tested. The correlations between each parameter were used to depict convergent validity. The robustness of the parameters to different projection (urogram), different definitions of the lateral acetabular margin, and a differing pelvic tilt were evaluated.

RESULTS

The intra- and interobserver reliabilities of CEA, AD and AA ranged from 0.777 to 0.925. The CEA, AD and AA showed acceptable validity in the correlation. The AD on the urograms was 22.0% higher than those on the standing hip radiographs (P < 0.001). When the osteophyte was included in the definition of lateral acetabular margin, the CEA and AD increased significantly (P < 0.001). In simulating pelvic tilting, the AD increased significantly with the anterior pelvic tilt (P < 0.001). The ARO and RA showed poor clinical relevance.

CONCLUSION

When measuring acetabular dysplasia, the AD is unsuitable for use, because it is not robust to different projection of beam and different pelvic tilts. Furthermore, one should consider that the CEA and AA are significantly influenced by different definitions of lateral acetabular margin.

Association of the D repeat polymorphism in the ASPN gene with developmental dysplasia of the hip: a case-control study in Han Chinese

Introduction

Developmental dysplasia of the hip (DDH) is a common skeletal disease, which is characterized by abnormal seating of the femoral head in the acetabulum. Genetic factors play a considerable role in the etiology of DDH. Asporin (ASPN) is an ECM protein which can bind to TGF-β1 and sequentially inhibit TGF-β/Smad signaling. A functional aspartic acid (D) repeat polymorphism of ASPN was first described as an osteoarthritis-associated polymorphism. As TGF-β is well known as an important regulator in the development of skeletal components, ASPN may also be involved in the etiology of DDH. Our objective is to evaluate whether the D repeat polymorphism of ASPN is associated with DDH in Han Chinese.

Methods

The D repeat polymorphism was genotyped in 370 DDH patients and 445 control subjects, and the allelic association of the D repeat was examined.

Results

From D11 to D18, eight alleles were identified. D13 allele is the most common allele both in control and DDH groups, the frequencies are 67.3% and 58.1% respectively. In the DDH group, a significantly higher frequency of the D14 allele and significantly lower frequency of D13 was observed. The association of D14 and D13 was found in both females and males after stratification by gender. There was no significant difference in any other alleles we examined.

Conclusions

Our results show an obvious association between the D repeat polymorphism of ASPN and DDH. It indicates that ASPN is an important regulator in the etiology of DDH.

Acetabular and proximal femoral alignment in patients with osteoarthritis of the dysplastic hip and its influence on the progression of disease

In order to evaluate the relationship between acetabular and proximal femoral alignment in the initiation and evolution of osteoarthritis of the dysplastic hip, the acetabular and femoral angles were calculated geometrically from radiographs of 62 patients with pre-arthrosis and early osteoarthritis. The sum of the lateral opening angle of the acetabulum and the neck-shaft angle was defined as the lateral instability index (LII), and the sum of the anterior opening angle of the acetabulum and the anteversion angle of the femoral neck as the anterior instability index (AII). These two indices were compared in dysplastic and unaffected hips. A total of 22 unilateral hips with pre-arthrosis were followed for at least 15 years to determine whether the two indices were associated with the progression of osteoarthritis. The LII of the affected hips (197.4 (sd 6.0)) was significantly greater than that of the unaffected hips (1830 (sd 6.9)). A follow-up study of 22 hips with pre-arthrosis showed that only the LII was associated with progression of the disease, and an LII of 196 was the threshold value for this progression.