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.

Characteristics and diagnostic factors associated with fresh lumbar spondylolysis in elementary school-aged children.

PURPOSE: We often encounter elementary school-aged children with fresh lumbar spondylolysis and non-union of bone. They may have factors that impede healing, and treatment outcomes need improvement. The purpose of this study was to investigate elementary school-aged patients with fresh lumbar spondylolysis and to identify characteristics that can aid in prompt diagnosis and proper therapy. METHODS: We retrospectively compared the characteristics of fresh lumbar spondylolysis in elementary school-aged children with those of older patients. We included patients aged 6-18 years with lower back pain and evidence of bone marrow oedema of lumbar pedicles on magnetic resonance imaging (MRI). The elementary school-aged group (group E) included 100 patients aged 6-12 years, and the senior group (group S) included 251 patients aged 13-18 years. We recorded patient sex, duration of lower back pain, injured site (lumbar level, unilateral/bilateral), presence of contralateral pars defect with evidence of high signal change on MRI (short tau inversion recovery), presence of spina bifida occulta (SBO), and follow-up treatment interruption rate. RESULTS: One-third of the patients in group E were female, and there was an even smaller proportion of females in group S. L5 lumbar spondylolysis was more common in group E. The treatment interruption rate was lower in group E. L5 SBO and contralateral pars defect were more common in group E. CONCLUSION: L5 lumbar spondylolysis, L5 SBO, and contralateral pars defect were important diagnostic factors in elementary school-aged patients. Identification of these characteristics will aid in prompt diagnosis and proper therapy.

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

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

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

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

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

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

New treatment method for developmental dysplasia of the hips after walking age: arthroscopic reduction with limboplasty based on the findings of preoperative imaging.

BACKGROUND: What makes treatment choice for developmental dysplasia of the hips diagnosed after walking age difficult is the poor understanding of prereduction conditions that obstruct the reduction in spatial terms. To evaluate these problems, we employed subtraction three-dimensional imaging to search for the factors involved in intraarticular obstruction. On the basis of the findings of preoperative subtraction threedimensional imaging from computed tomography, we developed a new method, a minimum invasive arthroscopic reduction with limboplasty, for reduction of developmental dysplasia of the hips after walking age. The purposes of this report were to: (1) describe the technique of the arthroscopic procedure, and (2) evaluate our new method using radiographic parameters. METHODS: Ten patients with ten hips with developmental dysplasia after walking age treated by arthroscopic reduction with limboplasty were included in this study. The mean age of the patients at reduction was 22.6 months (range, 18.6-29.7 months); mean age at follow up was 7.2 years (range, 3.9-10.9 years); and mean follow up was 5.4 years (range, 1.7-9.0 years). These ten hips were evaluated using radiographic measurements. RESULTS: Moderate or severe avascular necrosis of the femoral head was not observed. Two hips that had a spherical-shaped head with minimal residual height loss or coxa magna were classified as Kalamchi and MacEwen grade 1. Additional surgery had been performed for two hips classified as Severin group 4 during the course of follow up. These two hips were classified as Severin group 1 at final examination. One more hip was classified as Severin group 4 at final examination, and additional surgery was recommended. The remaining seven hips (70%) therefore obtained good evaluations by arthroscopic reduction with limboplasty alone. CONCLUSIONS: We developed a new reduction method by using an arthroscopic procedure for the reduction of developmental dysplasia of the hips after walking age when this dysplasia failed to be reduced with nonoperative methods. The result of our new method is acceptable because good evaluations were obtained in 70% of hips 5.4 years after reduction by our new method alone.