Keiji Haraguchi

Phase transformation of a zirconia ceramic head after total hip arthroplasty

We report two cases of surface deterioration of a zirconia ceramic femoral head associated with phase transformation after total hip arthroplasty. One head was retrieved at revision due to recurrent dislocation after six years and the other because of failure of the locking mechanism of the polyethylene liner after three years. The monoclinic content of the zirconia ceramics rose from 1% to about 30% on the surface of the heads. SEM revealed numerous craters indicating extraction of the zirconia ceramics at the surface. Surface roughness increased from an initial value of 0.006 microm up to 0.12 microm. This is the first report to show that phase transformation of zirconia ceramics causes deterioration of the surface roughness of the head in vivo after total hip arthroplasty.

Computed-Tomography-Based Computer Preoperative Planning for Total Hip Arthroplasty

For precise preoperative planning in total hip arthroplasty (THA), we developed a technique of computed tomography (CT)-based computer preoperative planning and compared this technique with the single X-ray and template method generally used. The subjects of this study were 42 hips in 38 patients who underwent THA using a cementless total hip system. Preoperatively, a standard anteroposterior X-ray of the hip was taken, and conventional preoperative planning was done with a template of the total hip system. Transverse images were obtained using a helical CT scanner, and a CT-based computer preoperative plan was performed on true coronal slice images of the proximal femur reconstructed from CT data. Postoperatively, 29 hips (69%) showed good proximal fit of the femoral component to the medial endosteal line. Of the 20 hips with good proximal fit on preoperative X-ray planning, 12 hips had good proximal fit on postoperative X rays. Sensitivity and specificity of the proximal fit on X-ray templating were 41 and 23%, respectively. In 27 of 28 hips with good proximal fit on reconstructed CT images preoperatively, the postoperative X ray revealed good proximal fit. Sensitivity and specificity of the proximal fit on computer planning were 93 and 86%, respectively. Twelve hips with good proximal fit on preoperative templating, the reconstructed images, and the postoperative X ray had 20 degrees or less of combined femoral neck anteversion and external rotational contracture of the hip on the X-ray table. Eight hips with good proximal fit on preoperative templating and proximal poor fit on the reconstructed images had 17-65 degrees of combined version and rotational contracture. In 16 hips with poor proximal fit on preoperative templating and good proximal fit on the reconstructed images, the combined version and rotational contracture ranged from 17 to 69 degrees. When combined femoral neck anteversion and external rotational contracture of the hip is less than 15 degrees, the simple X-ray and template method might be sufficient for THA planning. Otherwise, the CT-based method of preoperative planning is recommended.

Progression and cessation of collapse in osteonecrosis of the femoral head.

Thirty-five patients (54 hips) with osteonecrosis of the femoral head without collapse or only with a crescent sign were followed up for at least 5 years to clarify the natural course of osteonecrosis. During the followup, 28 hips (52%) in 21 patients collapsed including nine hips in nine patients with small necrotic lesions occupying less than the medial ⅔ of the weightbearing area. Cessation of collapse then was observed in 15 (14 patients) of the 28 hips (54%), especially in eight of the nine hips (89%) with small necrotic lesions. Of the 15 hips in 14 patients with cessation of collapse, 11 hips (73%) in 11 patients had less than 2 mm collapse and 10 hips in nine patients became asymptomatic. The analysis indicated that collapse of the femoral head does not necessarily determine a poor prognosis, and even after collapse occurs, subsequent cessation of collapse can be expected in a certain percentage of hips. Hips with less than 2 mm collapse and necrotic lesions occupying less than the medial ⅔ of the weightbearing area have a high chance of cessation of collapse and improvement of symptoms with no surgical intervention.

MR findings of necrotic lesions and the extralesional area of osteonecrosis of the femoral head.

Abstract Objective. To investigate the MR findings of necrotic lesions and the extralesional area of osteonecrosis of the femoral head (ONFH) for each of the radiological stages. Design and patients. Forty-nine hips in 29 patients (15 female, 14 male; mean age 38 years, range 17–59 years) were imaged using a 1.0-T superconducting magnet. T2-weighted spin echo pulse sequences (T2WI), spoiled gradient recalled echo pulse sequences (SPGR) and fat suppression SPGR (FS-SPGR), followed by Gd-DTPA enhanced fat suppression SPGR (Gd-FS-SPGR), were all obtained with the aid of a TORSO surface coil. Results and conclusions. While a normal fat intensity area with a low-intensity band on SPGR (band pattern) was seen in 16 of 16 stage 1 (100%), nine of 11 stage 2 (82%), four of 17 stage 3 (24%), and none of five stage 4 hips, all hips showed peripheral rim enhancement on Gd-FS-SPGR (100%). This enhancement band on Gd-FS-SPGR corresponded to histological findings of necrotic trabecular bone, repaired marrow, and fibrous reparative tissue. Bone marrow edema was also clearly demonstrated as a diffuse, high-intensity area outside this enhancement band on Gd-FS-SPGR in two stage 2 (18%), 12 stage 3 (71%), and one stage 4 hip (20%). In cases at stage 2 or more advanced stages with homogeneous or inhomogeneous low intensity on nonenhanced MRI, the reparative process both inside and outside the necrotic lesion, including bone marrow edema, was detected clearly on contrast- enhanced MRI.

Early MRI findings of rapidly destructive coxopathy

To diagnose rapidly destructive coxopathy (RDC) in its early stages and understand the pathomechanism of associated joint destruction, ten cases of RDC were followed by periodic MRI from onset of the disease. In the initial stage (stage 1) of RDC, when radiographs revealed slight narrowing of the joint space, a small subchondral area of low signal intensity was observed on T(1)-weighted images (T1WI) and inhomogeneous high intensity was observed on T(2)-weighted images (T2WI) in the antero-lateral portion of the femoral head. When radiographs showed obliteration of the joint space (stage 2), MRI revealed a diffuse area of low intensity on TIWI and high intensity on T2WI in the proximal femur, including the femoral neck and head, suggesting extensive bone marrow edema. The femoral head and acetabulum were aggressively destroyed (stage 3) in all cases 3 to 6 months after the diffuse abnormal pattern was observed on MRI. MRI in stage 3 cases showed low intensity areas on both T1WI and T2WI. RDC did not show the band-like pattern of low intensity on T1WI and high intensity on T2WI that typify MRI findings in cases of osteonecrosis. When joint space narrowing is observed radiographically, the diffuse abnormal pattern of low intensity on T1WI and high intensity on T2WI induced by a subchondral small lesion might be an early sign of RDC.

Bone scintigraphy for osteonecrosis of the knee in patients with non-traumatic osteonecrosis of the femoral head: comparison with magnetic resonance imaging

OBJECTIVE To determine whether technetium bone scintigraphy (BS) is useful for screening of non-traumatic osteonecrosis of the knee (ONK), which was a major affected site, secondary to the femoral head, among multiple osteonecrosis, in patients with non-traumatic osteonecrosis of the femoral head (ONFH). METHODS A total of 214 knee joints in 107 patients with ONFH were evaluated by BS and a comparison made with magnetic resonance imaging (MRI). ONK was classified into five sites, including the femoral condyles (ONFC), distal femoral metaphysis (ONFM), tibial plateau (ONTP), proximal tibial metaphysis (ONTM), and patella (ONP). RESULTS Based on the diagnosis by MRI, ONK was detected in 103 knees of 62 patients (48%). ONFC was most common (86 knees, 40%), ONFM (15%), followed by ONTM (10%), ONP (3%), and ONTP (0.9%). Sensitivity, specificity, and accuracy of BS for ONFC detection were 63%, 71%, and 68%, respectively. When the ONFC lesions on the coronal views of MRI were large or medium sized and occupied two thirds, or the entire anteroposterior joint surface on the sagittal views, the sensitivity of BS for ONFC detection increased to 89% (34/38 knees). The sensitivity of BS for ONFM, ONTM, and ONP detection was 3%, 0%, and 0%, respectively, but these lesions showed a low likelihood of collapse. CONCLUSION BS is useful for screening large ONK in patients with ONFH given that 89% of patients with ONFC who had a high risk of collapse of the knee were identified.

Dome (modified Chiari) pelvic osteotomy. 10- to 18-Year Followup Study

Ninety-six dome (modified Chiari) pelvic osteotomies in 87 patients with pain and disability because of osteoarthrosis secondary to hip dysplasia were reviewed. The mean age of the patients at the time of surgery was 29 years (range, 16–55 years). The mean followup was 13 years (range, 10–18 years). Forty-one hips were classified into a hip dysplasia stage, 32 hips into an early stage of osteoarthrosis, and 23 hips into an advanced stage of osteoarthrosis according to the radiographic grading of the Japanese Orthopaedic Association. The average preoperative Merle d’Aubigné and Postel hip score was 13.8, and the average score at final followup was 16.6. Excellent or good results with a score greater than 14 were achieved in 96% of the hips at final followup. Radiographically, signs of progression of osteoarthrosis were not seen in 87% of the hips. Osteoarthrosis progressed during the postoperative course in 13% of the hips. Four patients (four hips) eventually had a total hip arthroplasty at 13.8 years (range, 12.5–15.3 years) after surgery. The survival rate of dome pelvic osteotomy, using clinical failure as an end point, was 82% at 15 years. Using radiologic failure as an end point, 61 hips in 54 patients (survival rate, 78%) survived at 15 years. Using hip replacement as an end point, 92 hips in 83 patients (survival rate, 82%) survived at 15 years. Dome pelvic osteotomy is an excellent and effective operation for pain relief and functional maintenance of the hip.

Stem length and canal filling in uncemented custom-made total hip arthroplasty

Abstract We reviewed 60 custom-made femoral components of two different lengths : 125 mm (group A) and 100 mm (group B), in order to investigate the relationship between stem length and canal filling in uncemented custom-made total hip arthroplasty. There were no statistical differences between the two groups in age, gender, height, body weight, canal flare index, or bowing angle of the femur. Postoperatively there was no statistical difference between the two groups in the proximal canal filling, but significant difference in the distal canal filling (75.5% vs 85.8% on the anteroposterior view and 76.0% vs 82.5% in the lateral view, P<0.001). The distal canal filling inversely correlated with the ratio of the proximal portion and the distal portion of the stem curvature on the lateral view (lateral curve ratio of the stem, P=0.002). We conclude that superior filling at both the proximal and the distal levels can be obtained by using 100-mm custom made components with a small lateral curve ratio.Résumé. Pour étudier la relation existant entre la longueur de la tige et le remplissage du canal dans une arthroplastie totale de la hanche effectuée sur mesure, nous avons réexaminé 60 éléments fémoraux de deux longueurs différentes: 125 mm (groupe A) et 100 mm (groupe B). Que ce soit l’áge, le genre, la hauteur, le poids du corps, l’indice d’érasement du canal ou l’angle de courbure du fémur, il n’existait pas de différences statistiques entre les deux groupes. Alors qu’il n’y avait pas de différences statistiques post-opératoires entre les deux groupes dans le remplissage du canal proximal, il y avait par contre une différence significative dans le remplissage du canal distal (75.5% par rapport á 85.8% sur une vue antéropostérieure et 76.0% par rapport á 82.5% sur une vue latérale, P<0.001). Le remplissage du canal distal se rattachait inversement avec le rapport de la portion proximale et de la portion distale de la courbure de la tige sur la vue latérale (rapport de la courbure latérale, P=0.002). On en conclut que le remplissage supérieur aux niveaux proximaux et distaux peut étre obtenu en utilisant des éléments sur mesure de 100 mm avec un faible rapport de la courbure latérale.

Analysis of survivorship after total hip arthroplasty using a ceramic head.

To determine the clinical efficacy of an alumina ceramic head, 119 cemented total hip arthroplasties in 97 patients using an alumina head coupled with ethylene oxide gas sterilized polyethylene were reviewed. Eighty-two patients (101 hips) with greater than 10 years followup were evaluated clinically and radiographically (range, 10–17.6 years), and 97 patients (119 hips) were evaluated for survivorship analysis (range, 0.6–17.6 years). The average functional hip scores according to Merle d’Aubigné and Postel improved from 8.6 preoperatively to 15.0 at the final followup, and 57 patients (64 hips) had no pain. The average polyethylene wear rate was 0.15 mm/year (range, 0.04–0.34 mm/year). Patients with polyethylene wear greater than 3 mm showed significantly higher rates of acetabular loosening. Fifteen-year survival rates (with 95% confidence intervals) with radiographic evidence of aseptic loosening as the end point were 46.8% ± 13.4% in acetabular components and 91.9% ± 6.6% in femoral components. Fifteen-year survival rates of hip arthroplasties with revision because of aseptic loosening as the end point were 75.3% ± 10.2% and 97.9% ± 3.0%, respectively. Results of the current study suggest that using an alumina head instead of a metal head may not be beneficial when coupled with ethylene oxide gas sterilized polyethylene.

Scintigraphic image patterns in dysplastic coxarthrosis: Evaluation with reference to radiographic findings in 210 hips

Little is known about scintigraphic image patterns in the various stages of coxarthrosis. We assessed bone scintigraphy in 159 patients (210 hips) with dysplastic arthrosis of the hip. Scintigraphic images were divided into 5 types related to the radiographic stages of the disease. The scintigraphic images showed little, if any, uptake in the stage of prearthrosis. In the early stage, we found an increase in uptake in the weight bearing area in 30% of cases. In the advanced stage, more than half of the cases had an increase in uptake in the medial side of the joint and in the weight bearing area. In the terminal stage, a marked increase in uptake in the weight bearing area was commonest. Since the osteoblastic reaction intensified, a marked increase in uptake was seen not only in the weight bearing area, but also throughout the entire joint. These types of scintigraphic patterns, which change with the stage of coxarthrosis, seem to reflect the natural course of the disease. All hips with rapid progression of the disease showed a marked increase in uptake of radionuclide the entire joint at earlier stages.