Time elapsed from definitive diagnosis to surgery for osteonecrosis of the femoral head: a nationwide observational study in Japan.

OBJECTIVES: This study documents the time elapsed from the diagnosis of osteonecrosis of the femoral head (ONFH) to surgery, exploring the factors that influence ONFH severity. DESIGN: Retrospective observational study of a nationwide database. SETTING: The Kaplan-Meier method with log-rank tests was applied to examine the period from definitive diagnosis of ONFH to surgery using any surgery as the end point. For bilateral cases, the date of the first surgery was the endpoint. PARTICIPANTS: This study included 2074 ONFH cases registered in 34 university hospitals and highly specialised hospitals of the multicentre sentinel monitoring system of the Japanese Investigation Committee between 1997 and 2018. MAIN OUTCOME MEASURE: The primary outcome was the time from diagnosis to surgery. The secondary outcome was the proportion of subjects remaining without surgery at 3, 6 and 9 months, and at 1, 2 and 5 years after diagnosis. RESULTS: The median time to surgery was 9 months (IQR 4-22 months) after diagnosis of ONFH. The time to surgery was significantly shorter in the alcohol alone group and the combined corticosteroid and alcohol group than in the corticosteroid alone group (p=0.018 and p<0.001, respectively), in early stage ONFH with no or mild joint destruction (stages II and III, p<0.001), and with joint preserving surgery (p<0.001). The proportion without surgery was 75.8% at 3 months, 59.6% at 6 months, 48.2% at 9 months, 40.5% at 1 year, 22.2% at 2 years and 8.3% at 5 years. CONCLUSION: ONFH has been considered to be an intractable disease that often requires surgical treatment, but the fact that surgery was performed in more than half of the patients within 9 months from diagnosis suggests severe disease with a significant clinical impact. TRIAL REGISTRATION NUMBER: Chiba University ID1049.

Total hip arthroplasty after failed transtrochanteric rotational osteotomy for osteonecrosis of the femoral head: analysis of three-dimensional morphological features.

BACKGROUND: In total hip arthroplasty (THA) after failed transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH), deformity of the proximal femur has been reported to affect stem placement. The aims of this study were to evaluate the morphological changes in the proximal femur, muscle atrophy, and soft tissue thickening in THA after TRO and the clinical outcomes. METHODS: The TRO group included 17 patients (18 hips) who underwent THA after failed TRO. The control group included 21 patients (28 hips) who underwent primary THA for ONFH. To evaluate the deformity of the proximal femur before THA, we measured the anteroposterior and mediolateral diameters of the femur on computed tomographic slices 5 mm proximal to the lesser trochanter. To evaluate muscle atrophy and soft tissue thickening, we measured the thicknesses of the psoas major, iliac, and gluteus medius muscles and the anterior capsule of the hip joint. RESULTS: The ratio of the anteroposterior to mediolateral diameters of the proximal femur was significantly greater in the TRO group (p < 0.01). The thicknesses of the muscles did not differ between the two groups, whereas the anterior capsule was significantly thicker in the TRO group (p < 0.05). Varus or valgus stem alignment (> 3°) was frequent in the TRO group (p < 0.01). CONCLUSIONS: The round shape of the proximal femur was deformed after TRO compared with primary THA for ONFH, which may have caused malposition of the stem. In addition, we should pay attention to anterior protrusion of the proximal femur and thickening of the anterior capsule.

Significant removal of bacterial biofilm induced by multiple-Short ranges of electric interventions.

BACKGROUND: Biofilm-related infections are serious problems in the Orthopedics field, and Staphylococcus aureus are the most popular causative agents of bacterial infections associated with arthroplasty. Several studies demonstrated a synergistic effect of the electric intervention (EI) and the antibiotic administration in killing bacteria in biofilm; however, a constant, long-time EI was needed. In the present study, the effective removal of biofilm formed with S. aureus on a titanium ring by multiple times of one minute-EI was observed and described. METHODS: A methicillin-sensitive S. aureus clinical isolate was used to form biofilm on a titanium ring. After applying a series of EI with various combinations of the frequencies and timings, the amount and principal components of biofilms were assessed with crystal violet staining, live bacterial cell count, and fluorescence staining with confocal laser scanning microscopy. RESULTS: More than 60% biofilm removal was observed in the 2-time EI applied at 24 (1) and 72 (3) h (days) post bacterial exposure (PBE) and in the 3-time EI at 0 (0), 24 (1), and 72 (3) h (days) PBE, or at 24 (1), 48 (2), and 72 (3) h (days) PBE. The live bacterial cell numbers, the proportion of live and dead cells, and the amount of extracellular polysaccharide substances (EPS) of biofilm were similar with or without EI. It was assumed that an excess amount of the biofilm removal shown in the several EI was not attributed to the effect of the electrolysis. CONCLUSIONS: The effective removal of biofilm was observed when multiple times 1 min EI was applied without any changes in the proportion of live and dead bacteria or the amount of EPS. The mechanisms to explain extra biofilm removal remain to be elucidated.

Secure paediatric pelvic fracture external fixation using an intraoperative support device.

Secure fixation by inserting a half-pin into the iliac crest as a pelvic external fixator is important. However, the thickness of the iliac bone depends on its location and this makes it difficult to insert a half-pin accurately. The iliac crest is especially narrow in the paediatric pelvis, making it difficult to insert the half-pin accurately compared with an adult pelvis. A case of pelvic external fixation is described for a paediatric pelvic fracture in this report, in which preoperative planning for half-pin insertion was performed accurately using a preoperative three-dimensional CT based on an intraoperative support device that uses the functional pelvic plane as a reference.

Visualization of acetabular coverage with radar chart before and after curved periacetabular osteotomy in dysplastic hips.

BACKGROUND: Curved periacetabular osteotomy (CPO) is indicated for patients with developmental dysplasia of hip (DDH) to prevent progressive osteoarthritis. Patients with DDH have not only lateral acetabulum dysplasia but also anterior and posterior dysplasia. The full circumference acetabular coverage angle (ACA) of the femoral head should be evaluated preoperatively. This study aimed to determine the full circumference ACA in the patients with DDH before and after CPO compared with the coverage in normal patients. METHODS: Twenty-three patients (a total of 24 hips) with DDH undergoing CPO between February 2006 and March 2014 were included in this study. The normal group was defined as the normal side in patients with unilateral osteonecrosis of the femoral head (ONFH) and the non-collapsed femoral head side in patients with bilateral ONFH. Pre- and postoperative hip functions were evaluated using the Japanese Orthopedic Association (JOA) hip score. ACA was measured using pre- and postoperative three-dimensional computed tomography (3DCT) and described as a clock using a radar chart. The ACA of the normal group was evaluated in the same manner as that for patients who underwent CPO. The ACA before CPO was compared with the ACA after CPO, the ACA before CPO was compared with that of the normal group and the ACA after CPO was compared with that of the normal group at each location. RESULTS: The mean JOA hip scores improved significantly from 69 preoperatively to 88 postoperatively. The superior, posterior, and anterior ACA after CPO significantly increased and the inferior ACA decreased compared with ACA before CPO. The superior, posterior, and anterior ACA before CPO were significantly smaller than ACA in the normal group. The ACA after CPO were similar to the normal group. CONCLUSIONS: CPO improved the anterosuperior coverage of the femoral head but reduced its inferior coverage. The radar chart could visualize acetabulum full circumference and was useful for three-dimensional pre-postoperative evaluation.

Real-time three-dimensional fluoroscopy-navigated percutaneous pelvic screw placement for fragility fractures of the pelvis in the hybrid operating room.

BACKGROUND: The prognosis of conservative treatment for fragility fracture of the pelvis (FFP) in the older patients remains poor. Percutaneous pelvic screw placement (PPSP), which aids in the treatment of FFP, can be challenging to perform using fluoroscopy alone because of the proximity of blood vessels and neuroforamina. Hence, this study aimed to investigate the accuracy and clinical outcomes of PPSP using real-time 3D fluoroscopic navigation for FFP in the hybrid operating room. METHODS: This study included 41 patients with FFP who underwent PPSP in a hybrid operating room between April 2016 and December 2020. Intraoperative C-arm cone-beam CT was performed under general anesthesia. Guidewire trajectory was planned using a needle guidance system. The guidewire was inserted along the overlaid trajectory using 3D fluoroscopic navigation, and a 6.5 mm cannulated cancellous screw (CCS) was placed. The clinical outcomes and accuracy of the screw placement were then investigated. RESULTS: A total of 121 screws were placed. The mean operative time was 84 ± 38.7 minutes, and the mean blood loss was 7.6 ± 3.8 g. The mean time to wheelchair transfer was 2 days postoperatively. Pain was relieved in 35 patients. Gait ability from preoperative and latest follow-up after surgery was maintained in 30 (73%) patients. All 41 patients achieved bone union. Of the 121 screws, 119 were grade 0 with no misplacement; only 2 patients had grade 1 perforations. CONCLUSION: PPSP using real-time 3D fluoroscopic navigation in a hybrid operating room was accurate and useful for early mobilization and pain relief among older patients with FFP with an already-installed needle biopsy application.

Embolization followed by resection of the heterotopic hip joint ossification with spinal cord injury.

BACKGROUND: Heterotopic ossification of large joints, such as knees and hips, has been reported after spinal cord injury, possibly leading to decreased activity of daily living due to a limited range of motion of the affected joint. Therefore, heterotopic ossification resection is performed to improve the range of motion, but it might cause massive bleeding as a complication. METHODS: In this case, the patient had a history of spinal cord injury and developed heterotopic ossification after the left hip injury. He had left hip ankylosis and could not transfer to a wheelchair by himself; therefore, heterotopic ossification resection was planned. On conducting contrast-enhanced computed tomography, the supplying arteries extending to the heterotopic ossification could be identified. A day before the surgery, embolization of the branches by interventional radiology was performed. RESULTS: Heterotopic ossification resection was performed with an 820-ml blood loss. Postoperative rehabilitation was continued, and range of motion continued to improve without heterotopic ossification recurrence 2 years post-surgery. CONCLUSIONS: The combination of preoperative contrast-enhanced computed tomography and embolization was useful in treating heterotopic ossification.

Accuracy of Acetabular Cup Placement During Total Hip Arthroplasty in Supine Position Using a Pelvic Rotation Correction Device.

Background: Accurate cup placement during total hip arthroplasty (THA) is difficult because the intraoperative pelvic position changes even in supine patient position. We developed a device known as HipPointer; it corrects pelvic rotation and creates a functional pelvic plane as a reference. The aim of this study was to determine the device placement accuracy and investigate causes of error. Material and methods: HipPointer was used for cup placement in 353 hips of 308 patients who underwent direct-anterior-approach THA in supine position. The mean age at surgery and body mass index were 63.9 (17-90) years and 24.9 (16.6-42.0) kg/m2, respectively. The mean observation period was 40.5 (12-73) months. To investigate the accuracy of HipPointer, preoperative planning and postoperative cup placement angles relative to the functional pelvic plane were evaluated using a three-dimensional analysis software, and absolute errors were determined. Results: The means ± standard deviations of radiographic inclination (RI) and radiographic anteversion (RA) were 40.2 ± 3.0° and 15.8 ± 3.6°, respectively. The absolute errors of RI and RA were 2.2 ± 2.0° and 2.7 ± 2.3°, respectively. The ratio of the cup placement angle for which both RI and RA are ≤10° in the target zone was 99% (350/353 hips), and the ratio of the absolute errors for which both RI and RA are ≤5° was 80.4% (284/353 hips). Conclusions: HipPointer is simple in structure, easy to use, and useful for direct-anterior-approach THA in supine position. It provides good cup placement accuracy.

MPC-grafted highly cross-linked polyethylene liners retrieved from short-term total hip arthroplasty: Further evidences for the unsuitability of the MPC method.

An analysis is presented of four short-term retrieved highly crosslinked polyethylene (HXLPE) hip liners grafted with 2-methacryloyloxyethyl phosphorylcholine (MPC) on their bearing surfaces, which were recently commercialized as a new generation of artificial hip joints. Straightforward evidences by X-ray photoelectron spectroscopy (XPS) confirmed that the MPC layer peeled off on the bearing surface of all short-term liners in both main wear and nonwear zones. Analyses by Fourier-transform infrared spectroscopy with attenuated total reflection assessed the extent of surface oxidation and revealed the type of oxidative species. Electron spin resonance analyses, which compared retrievals and as-received samples, revealed the presence of different species of alkoxyl CO• radicals. This study suggests that MPC grafts on polyethylene do not offer any additional protection from oxidation and can delaminate prematurely after short-term in vivo exposure.

Quality of life of patients with osteonecrosis of the femoral head: a multicentre study.

PURPOSE: Quality-of-life (QOL) assessments in patients with osteonecrosis of the femoral head (ONFH) have rarely been reported. This multicentre study aimed to elucidate the relationship between disease severity, including necrotic lesion type and radiological staging, and QOL, as well as between patients' characteristics and QOL. METHODS: Two hundred seventy-four patients with ONFH (108 females, 166 males; median age, 46 years) were asked to complete self-assessment QOL questionnaires including the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire, Oxford Hip Score, and SF-12v2. RESULTS: Patients with large necrotic lesion type or collapsed ONFH had low QOL scores. Among patients with non-collapsed lesions, patients with alcohol-associated ONFH had lower QOL scores than those with steroid-associated ONFH, those with bilateral ONFH had lower mental scores, and male patients had worse social condition scores. Among patients with collapsed lesions, middle-aged patients exhibited lower mental QOL, and a strong correlation was observed between social activity and mental health. CONCLUSION: Collapsed ONFH was associated with low QOL scores. Among patients with non-collapsed lesions, alcohol-associated ONFH, bilateral disease, and male sex were linked to low QOL scores.

Three-dimensional analysis of deformities of the radius and ulna in congenital proximal radioulnar synostosis.

We reconstructed three-dimensional images of radius and ulna in 38 forearms of 25 patients with congenital proximal radioulnar synostosis from their computed tomographic studies. We also analysed correlations between the deformities of radius and ulna and degrees of fixed pronation of these forearms. The average ulnar deviation, flexion and internal rotation deformities of the radius were 6°, 3° and 18°, respectively. The average radial deviation, extension and internal rotation deformities of the ulna were 3°, 4° and 30°, respectively. The flexion deformity of the radius and the internal rotation deformity of the radius and ulna were correlated significantly with degree of fixed pronation. We conclude that the patients with congenital proximal radioulnar synostosis have remarkable flexion deformity of the radius and internal rotation deformity of the radius and ulna, which might impede forearm rotation after corrective surgery in the proximal part of the forearm.

Does the extent of osteonecrosis affect the survival of hip resurfacing?

BACKGROUND: The effect of the extent of osteonecrosis on the survival of hip resurfacing for osteonecrosis of the femoral head (ONFH) has not been well documented, but is a potentially important variable in the decision to perform resurfacing. QUESTIONS/PURPOSES: We examined (1) the relationship between the volume of osteonecrosis in the femoral head before surgery and the extent of the residual necrotic bone after femoral head machining, (2) how the extent of the residual necrotic bone relative to the resurfaced femoral head (after femoral head machining) affected the survival of total hip resurfacing for patients with ONFH, and (3) how the extent of the necrotic bone relative to the entire femoral head (before femoral head machining) affected the survival and clinical outcome scores of patients who underwent total hip resurfacing. METHODS: Thirty-three patients (39 hips) who underwent hip resurfacing were reviewed after a mean followup of 8 years. The extent of osteonecrosis in the femoral head and residual osteonecrosis in the implant bony bed after femoral head machining were estimated using a three-dimensional MRI-based templating system. RESULTS: There was a statistically significant difference in the extent of osteonecrosis before and after femoral head machining, although the two were well correlated (r = 0.97). The mean percentage of osteonecrosis in the implant bony bed after femoral head machining was 5% smaller than that relative to the entire femoral head (range, -9% to 15%). There were no significant differences in implant survival between groups with small and large osteonecrosis classified by either the total amount of osteonecrosis before surgery or residual osteonecrosis after femoral head machining. CONCLUSION: The extent of osteonecrosis in the femoral head significantly decreased after femoral head machining. Neither the residual osteonecrosis volume in the implant bony bed after femoral head machining nor the total amount of osteonecrosis before femoral head machining had significant influence on the survival of hip resurfacing.

Incidence and natural course of initial polar gaps in Birmingham Hip Resurfacing cups.

The purpose of this study was to retrospectively investigate the incidence of initial polar gaps and their effect on clinical results in Birmingham Hip Resurfacing cups. A total of 151 hips in 134 patients who underwent hip resurfacing at a mean age of 50 years were examined. The mean follow-up period was 7 years. A polar gap was identified in 47 hips (31%) with a mean width of 2.1 mm. Gaps of 2 mm or more were identified in 21 hips, 6 of which showed reductions in cup inclination during the initial 3 months. After 3 months, no progressive cup migration was observed. There was no cup revision. All gaps were filled with bone within 2 years of surgery. The initial polar gaps had no significant influence on the stability of hydroxyapatite-coated Porocast cobalt-chromium hemispherical monoblock cups (Midland Medical Technologies Ltd, Birmingham, UK), although gaps of 2 mm or more had a higher risk of early migration.

Osteoarthritis hip joints in Japan: involvement of acetabular dysplasia.

BACKGROUND: We conducted a nationwide epidemiologic study regarding hip osteoarthritis (OA) in Japan, and a previous report found these patients to be unique in comparison to Caucasians. This report focused on the data regarding each hip joint, and the involvement of acetabular dysplasia with hip OA was analyzed. METHODS: Seven hundred twenty OA hips were examined. Sixty-five joints with osteonecrosis of the femoral head and 215 non-OA contralateral joints of the unilateral patients were examined as controls. The revised system of stage classification for hip OA of the Japanese Orthopedic Association (JOA) was used according to the reproducibility in order to ensure reliable data from the multiple institutions. The acetabular dysplasia indexes were also chosen according to the reproducibility and measured in the radiograph of bilateral hip joints. The clinical score was assessed using the JOA scoring system. The relative risk of the grade of acetabular dysplasia indexes for hip OA was calculated as the odds ratio and the 95% confidence interval. RESULTS: The stage of the OA joints deteriorated with increasing age. The clinical scores also decreased. The grade of the acetabular dysplasia indexes of the OA joints was significantly higher than that of the control joints. Each index of acetabular dysplasia demonstrated significantly increased odds ratios for hip OA. Among the OA joints, the deterioration of the OA stage was found to be significantly associated with an increasing grade of acetabular dysplasia. The odds ratio for OA deterioration in the acetabular dysplasia index was also obtained. The joints of females tended to have a higher grade and prevalence of acetabular dysplasia than those of males. CONCLUSIONS: These findings confirmed a high prevalence of acetabular dysplasia in hip OA joints in Japan. Acetabular dysplasia was one of the most important factors associated with hip OA.