The epidemiology of developmental dysplasia of the hip in Japan: Findings from a nationwide multi-center survey.

BACKGROUND: It has been reported that the national incidence of developmental dysplasia of the hip (DDH) has decreased in Japan. This is because of prevention activities after birth since around 1970. However, cases of late-diagnosed DDH have still been noted in some children's hospitals. There has been no recent survey of DDH in Japan. The purpose of this study was to investigate the current epidemiology of DDH using a comprehensive nationwide survey. METHODS: A questionnaire was sent to orthopedic surgeons in 1987 facilities nationwide, who were asked to complete and return a survey card on each DDH patient treated between April 2011 and March 2013. RESULTS: A total of 783 (39%) facilities completed and returned the card. Of these, 79% reported no cases of DDH-related dislocation over the 2-year period, while the remaining facilities reported 1295 cases. The characteristics of children diagnosed with DDH-related dislocation were as follows: girls (89%), left side involvement (69%), bilateral involvement (4%), positive family history (27%), first-born (56%), and pelvic position at birth (15%). Seasonal variation showed an increase in DDH incidence among those born in the winter. Overall, 199 cases (15%) were diagnosed at >1 year of age, and these included 36 cases diagnosed very late, at >3 years of age. The majority of the 199 cases of late diagnosis had received earlier routine screening at <1 year of age. CONCLUSION: The characteristics of the children diagnosed with DDH nationwide were similar to past data from local regions. However, many children were diagnosed late (>1 year of age), particularly in the more populous regions. The findings identify a need for improved early routine screening for DDH in Japan.

Is the timing of surgery associated with avascular necrosis after unstable slipped capital femoral epiphysis? A multicenter study.

BACKGROUND: An unstable slipped capital femoral epiphysis (SCFE) is associated with a high rate of avascular necrosis (AVN). The etiology of AVN seems to be multifactorial, although it is not thoroughly known. The aims of our study were to determine the rate of AVN after an unstable SCFE and to investigate the risk factors for AVN, specifically evaluating the notion of an "unsafe window", during which medical interventions would increase the risk for AVN. METHODS: This retrospective multicenter study included 60 patients with an unstable SCFE diagnosed between 1985 and 2014. Timing of surgery was evaluated for three time periods, from acute onset of symptoms to surgery: period I, <24 h; period II, between 24 h and 7 days; and period III, >7 days. Multivariate logistic regression analysis was used to identify risk factors for AVN. RESULTS: Closed reduction and pinning was performed in 43 patients and in situ pinning in 17. Among these cases, 16 patients (27%) developed AVN. The rate of AVN was significantly higher in patients treated by closed reduction and pinning (15/43, 35%) than in those treated by in situ pinning (1/17, 5.9%) (p = 0.022). In patients treated by closed reduction and pinning, the incidence of AVN was 2/11 (18%) in period I, 10/13 (77%) in period II and 3/15 (20%) in period III, showing the significantly higher rate in period II (p = 0.002). The surgery provided in period II was identified as an independent risk factor for the development of AVN. CONCLUSIONS: Our rate of AVN was 27% using two classical treatment methods. Time-to-surgery, between 24 h and 7 days, was independently associated with AVN, supporting the possible existence of an "unsafe window" in patients with unstable SCFE treated by closed reduction and pinning.

Treatment for unstable slipped capital femoral epiphysis: Current status and future challenge in Japan.

BACKGROUND: Treatment for unstable slipped capital femoral epiphysis (SCFE) is challenging and controversial. For many years, the debate centered around closed treatments and especially the pros and cons of manual reduction and its concrete procedure. However, recent studies reported on open treatments such as open reduction through an anterior approach and modified Dunn procedure. Being in a period of such transition, we investigated the current status and future challenge of treatment for unstable SCFE. METHODS: A questionnaire survey of medical institutions specializing in pediatric hip disorders across Japan was conducted. Survey items were the accurate diagnosis of physeal stability, the pre- and intra-operative evaluation of epiphyseal hemodynamics, and current treatment strategy. RESULTS: Survey responses returned from 29 out of 40 participant institutions (response rate: 73%) revealed that 55% of the institutions evaluated physeal stability based on clinical findings of ambulation capability in accordance with the Loder classification. Another 38% diagnosed physeal stability comprehensively by combining the Loder classification and imaging findings. Epiphyseal hemodynamics was assessed preoperatively in 18% of the institutions, effectively using angiography, contrast-enhanced magnetic resonance imaging (MRI), and bone scintigraphy. Intraoperative assessment was performed in 13% based on the bleeding through a drilling hole on the articular surface and observation of the cancellous bone color during open surgeries. As a treatment strategy, 52% of the institutions used in-situ fixation, while another 38% used manual reduction and internal fixation. On the other hand, open reduction was used at 3 institutions (the remaining 10%): the modified Dunn procedure at 2 institutions and arthrotomy at 1 institution. CONCLUSION: Treatment for unstable SCFE remains controversial, but closed treatments without hemodynamic monitoring is no longer the center of the controversy. Today, the topic of the discussion is shifting toward how to correlate hemodynamic findings with treatment procedures and the indications for open treatments.

Subclinical bilateral involvement of the hip in patients with slipped capital femoral epiphysis: a multicentre study.

PURPOSE: This study was conducted to assess the posterior inclination of the contralateral femoral epiphysis in patients with unilateral slipped capital femoral epiphysis (SCFE). METHODS: The posterior sloping angle (PSA) was measured using lateral radiographs in 67 patients with a unilateral SCFE and in 41 age-matched normal controls. A symptomatic epiphyseal slip was defined as the development of SCFE. RESULTS: The contralateral PSA in SCFE patients was more widely distributed and significantly larger compared to controls (15.0° vs. 9.0°, p < 0.0001). Forty-seven hips (70.1%) had a PSA of greater than 12.8°, which was +2SD of the control hips. Of the 65 hips excluding the two cases with prophylactic pinning, 11 hips (16.9%) eventually developed a contralateral SCFE during adolescence and their PSA at the initial visit was significantly larger compared to patients without a contralateral SCFE (18.0° vs. 14.3°, p < 0.005) with a cutoff value of 19°. CONCLUSIONS: These findings suggested the possibility of bilateral hip involvement in SCFE patients. Hips with greater degrees of PSA (> 19°) are likely to become symptomatic.

Remodelling of femoral head-neck junction in slipped capital femoral epiphysis: a multicentre study.

PURPOSE: We examined the remodelling of the femoral head-neck junction in patients with slipped capital femoral epiphysis (SCFE) and the frequency of residual cam deformities. METHODS: We reviewed 69 hips in 56 patients with stable SCFE who had undergone in situ pinning. Mean age at slip was 11.7 years and the follow-up period 63.4 months. Cam deformity was evaluated using the anterior offset alpha (α) angle and head-neck offset ratio (HNOR). RESULTS: The average α angle and HNOR significantly improved from 76.2° to 51.3° and 0.086 to 0.135, respectively; 25 hips (36.2%) still had an α angle greater than 50°, and 32 hips (46.4%) had an HNOR of under 0.145. A multivariate analysis selected age at onset and slip angle as risk factors for cam deformity, with cutoff values 11.1 years and 21.0°, respectively. CONCLUSIONS: Although most hips had remodelling of the head-neck junction, 29.4 % had residual cam deformities that may be susceptible to femoroacetabular impingement.

Diagnostic imaging for elbow TRASH lesions in children and usefulness of ultrasonography using standard planes.

Fractures around the elbow in children should be carefully evaluated because the main portion is cartilaginous, and radiographs are not completely reliable. This study aimed to assess the diagnostic imaging for pediatric elbow fractures that require special attention and consider the usefulness of ultrasonography with seven standard planes for the diagnosis. Patients diagnosed with elbow fractures wherein TRASH (The Radiographic Appearance Seemed Harmless) lesions were evaluated retrospectively. The diagnoses on initial radiographs, final diagnoses, additional imaging excluding radiographs, and the treatments were investigated. The standard planes for ultrasonography to detect elbow fractures included an anterior transverse scan at the level of the capitellum and proximal radioulnar joint, an anterior longitudinal scan at the level of the humeroradial and humeroulnar joints, a longitudinal scan along the lateral and medial border of the distal humerus, and a posterior longitudinal scan at the level of the distal humerus. A total of 107 patients with an average age of 5.8 years (range, 0-12 years) at the time of diagnosis were included. Of 46 (43.0%) patients misdiagnosed at the initial radiograph, 19 (17.8%) needed additional treatments due to inappropriate initial management. Ultrasonography using the standard planes was useful for prompt diagnosis and appropriate treatment. Prompt and appropriate evaluation with ultrasonography can prevent the mismanagement of pediatric elbow injuries. Level of evidence: Level IV-retrospective case series.

Increased psoas tendon running angle in patients with Legg-Calvé-Perthes disease: a new theory for the aetiology of children with avascular femoral head necrosis.

The cause of Legg-Calvé-Perthes disease (LCPD) remains unknown. We propose a new hypothesis that the iliopsoas muscle and/or tendon affects the progression of ischemic necrosis of the femoral head as an anatomical factor. The purpose of this study was to test this hypothesis by measuring the psoas major tendon angle (PMTA) and cross-sectional area (CSA) of the iliopsoas muscle on MRI. We selected three predetermined axial MRI scans at the level of the psoas major tendon origin, the femoral head, and the lesser trochanter. We calculated the proximal, distal, and combined PMTA and compared these angles between the LCPD group and the transient synovitis (TS) group as a control. Our results revealed that the proximal PMTAs of the LCPD-affected sides were significantly greater than in the TS controls (P < 0.05), while there were no significant differences in the proximal PMTA, combined PMTA, and CSA. This result indicates that the psoas major tendon of the patient with LCPD curves sharply on the anterior capsule of the hip joint more than in the control group patients. This sudden curve of the psoas major tendon may be involved in the development of LCPD. We measured PMTAs in patients with LCPD. Our findings suggested that the running curve of the psoas major tendon is an anatomical factor that influences the development of mechanically-induced ischemia in LCPD.

Open-wedge osteotomy for thumb radial angulation in Apert syndrome using a bone-graft substitute.

A short thumb with radial angulation causes loss of hand function in patients with Apert syndrome. Although past reports have described various procedures for the correction of the thumb, there has been no consensus on the best procedure. This study aimed to assess the clinical and radiographic results of a surgical technique for the correction of a thumb radial angulation deformity: open-wedge osteotomy using a bone-graft substitute. Ten patients (18 thumbs) who underwent open-wedge osteotomy on the proximal phalange using a bone-graft substitute were evaluated retrospectively. The open-wedge osteotomies had been performed at the center of the proximal phalanx. Thumb radial angles and thumb lengths were measured on radiographs, and the clinical results were investigated, including bone union and complications. The median patient age at the time of surgery was 5.8 years, and the average follow-up period was 6.7 years. The average thumb radial angle was 57.3° preoperatively, 6.5° immediately postoperatively, and 19.8° at the most recent follow-up. The average thumb length was 12.1 mm preoperatively, 18.1 mm immediately postoperatively, and 22.3 mm at the most recent follow-up, indicating an extension effect of more than 50% immediately postoperatively. In all cases, the artificial bone had been absorbed and developed into autologous bone, and there were no complications such as infection and skin necrosis. These findings suggest that open-wedge osteotomy with an artificial bone substitute is simple and effective for treating radial-angulation deformities in patients with Apert syndrome. Level of evidence: Level IV - retrospective case series.

Costal osteochondral graft for a postoperative cartilage defect in a patient with polydactyly.

We present a case of a postoperative cartilage defect in a patient with polydactyly who was treated with a costal osteochondral graft. Excision of the radial digit and ligamentous periosteal flap with longitudinal osteotomy were performed when the patient was 1 year old. The alignment of the interphalangeal joint was straight after surgery, but the deviation gradually developed. A revision surgery using a costal osteochondral graft was performed when the patient was 3 years old. A satisfactory outcome was obtained at the 3-year follow-up. The authors suggest that a costal osteochondral graft may be a reasonable option for revision surgery for a postoperative cartilage defect.

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.

Clinical experiences of focal periphyseal edema zones in adolescent knees: case reports.

Focal periphyseal edema (FOPE) zones were first described in 2011. The aim of this report was to investigate the clinical course of patients with FOPE zones. Three adolescent patients with a FOPE zone in the knee were treated and observed for a maximum of 2 years. No symptoms or leg-length discrepancy developed at the final follow-up after conservative therapies. This is the first report on the follow-up of FOPE zones with a maximum of 2 years. The results suggest that observation of FOPE zones may be sufficient without invasive examinations and treatment.

Zeta-potentials of alginate-PLL capsules: a predictive measure for biocompatibility?

Alginate-poly-L-lysine (PLL) microencapsulation of cells is a promising approach to prevent rejection in the absence of immunosuppression. Clinical application, however, is hampered by insufficient insight in factors influencing biocompatibility of the capsules. By now, it has been accepted that not only the chemical composition of the materials applied but also other factors contribute to bioincompatibility. The zeta-potential serves as a measure for the electrical charge of the surface and has been shown to be a predictive value for the interfacial reactions between the biomaterial and the surrounding tissue in other applications. In the present study, we have assessed the streaming potential of alginate-PLL capsules composed of either low-, intermediate-, or high-guluronic (G) alginate to calculate the zeta-potential. The zeta-potentials of the capsules were compared to the biological response against the capsules at 4 weeks after implantation in the rat. We show that high-G and low-G alginates provoke a more severe response in the rat than capsules prepared of intermediate-G alginate. This correlates with a higher zeta-potential of the high-G and low-G alginates and by a change in zeta-potential at lower pH. These lower pH-levels are common directly after implantation as the consequence of a host-response associated with mandatory surgery. Our results suggest that we should not only consider the capsule properties under physiological circumstances to explain bioincompatibility but also the capsule features during common pathophysiological situations.

Closed reduction of slipped capital femoral epiphysis: high-risk factor for avascular necrosis.

How should we treat acute/unstable slipped capital femoral epiphysis (SCFE) without the development of avascular necrosis (AVN)? To answer this question, we investigated the risk factors of AVN development after SCFE. Seventy-six hips of 64 patients were classified using two kinds of classification systems, Loder's classification based on instability and the conventional classification based on the duration of symptom, because both classifications are related to AVN development. Of 21 unstable SCFEs, seven hips developed AVN. Of 35 hips defined as acute or acute on chronic, nine hips developed AVN. Two stable SCFEs of Loder's classification developed AVN, one was acute and the other was acute on chronic. No hips of chronic SCFE developed AVN. The factor that had influenced AVN development was only closed reduction, whether purposefully or inadvertently, in an acute or unstable SCFE. On the basis of the findings of this study, one should not embark on any modality of closed reduction for an unstable or acute form of SCFE, as there is a high risk for occurrence of AVN. For the same reason, a traction table should not be used for SCFE fixation, so as to avoid an inadvertent reduction or force that can lead to AVN.

Comparison of clinical outcome after treatment of hip arthritis caused by MRSA with that caused by non-MRSA in infants.

We compared the results of four patients treated for septic arthritis of the hip caused by methicillin-resistant Staphylococcus aureus (MRSA) with those of five non-MRSA cases. All four patients with MRSA were neonates when infection occurred, and all four had preceding sepsis and marked swelling of the thigh. The mean duration of follow-up was 5.6 years. At the time of most recent follow-up, all four exhibited severe discrepancy in leg length, and their femoral heads exhibited high-grade deformation according to the Choi classification. In contrast, in the non-MRSA cases, the mean age at infection was 2.2 years and the mean duration of follow-up was 2.9 years. At the most recent follow-up, they exhibited no remarkable discrepancy in leg length and only low-grade deformation of the femoral head. In this study, patients with MRSA showed more marked deformity of the hip and discrepancy of leg length because of lower age and to the presence of organisms resistant to antibiotics. Possible strategies for early diagnosis to prevent poor results after MRSA-induced hip arthritis include the following: (i) ensuring that pediatricians are familiar with the early signs of infection of the hip joint, (ii) aggressive puncture and drainage of pus from the affected joint, and (iii) initial use of antibiotics effective in treating MRSA, especially for patients suspected to have MRSA in the neonatal nursery.

Calcaneal apophyseal avulsion fracture.

Isolated fracture of the calcaneal apophysis is a rare injury in children and adolescents. In this study, we report on a case of a displaced calcaneal apophyseal avulsion fracture in a child treated with open reduction and internal fixation, as well as a review of the literature. A 9-year-old female child presented to the senior surgeon complaining of acute heel pain after a gymnastic injury. She was diagnosed with a displaced, isolated fracture of the proximal calcaneal apophysis for which she underwent open reduction and internal fixation. On the magnetic resonance imaging (MRI) examination, we could diagnose that her injury was not chronic but acute because there was no change of intensity in the metaphyseal area. A combination of bioabsorbable suture tacks and pins was used to anatomically fix the fragment using the tension band wiring technique. At 2 years and 6 months follow-up, she had full range of motion, complete return of strength. We report here on the successful surgical treatment and the first case evaluated by MRI of an avulsion fracture of the calcaneal apophysis in a child.