Takashige Umeyama

Rotational acetabular osteotomy using biodegradable internal fixation

Abstract We used biodegradable poly-l-lactide screws in rotational acetabular osteotomy in 41 hips of 41 patients, and studied the complications after an average follow-up of 4.9 years (range 1.0–7.7 years). There were 39 females and 2 males, their average age at the time of the operation was 32 years (range 12–55 years). A small subcutaneous abscess appeared around the non-absorbable sutures in 2 patients after surgery. There was 1 case of thrombophlebitis and 1 of local dermatitis. The small subcutaneous abscess resolved after the removal of the suture material in the 2 cases, and the thrombophlebitis resolved with aspirin. The local dermatitis persisted but was cured by local steroid therapy over 5.8 years. The incidence of local dermatitis after the use of biodegradable implants should be further investigated.Résumé Nous avons utilisé des vis biodégradables en poly L lactide pour les ostétomies acétabulaires rotatoires des 41 hanches de 41 patients et nous avons étudié les complications possibles sur un suivi moyen de 4.9 ans (de 1 à 7.7 ans). L’échantillon comportait 39 femmes et 2 hommes. L’âge moyen au moment de l’opération était de 32 ans (12 à 55 ans). Nous avons noté 2 cas de complication post-opératoire sous la forme d’un petit abcès sous-cutané autour des sutures irrésorbables, 1 cas de thrombophlébite et 1 cas d’eczéma local. Le petit abcès souscutané s’est résorbé après enlèvement du matériau de suture dans les 2 cas, la thrombophlébite a été traiteé l’aspirine et l’eczéma local a été soigné par une thérapie locale aux stéroides en 5.8 ans. La fréquence des dermatites locales après l’utilisation des implants biodégradables devrait être étudiée sur un plus grand nombre de cas.

Rotational acetabular osteotomy for the treatment of dysplastic hips with end-stage osteoarthrosis ; a biological alternative to total hip arthroplasty?

Abstract We evaluated the results of rotational acetabular osteotomy (RAO) for the treatment of dysplastic hips with end-stage osteoarthrosis. Sixteen patients, aged 15–¶45 years at the time of surgery, were reviewed at a mean follow-up of 8 years (range 3–17 years). Remodeling of the hip joint occurred in half of the patients, with significant clinical improvement. A subsequent total hip arthroplasty, however, was done within 2 years after RAO in two other patients who had had large bone cysts in the femoral head and acetabulum. We suggest that RAO may be the procedure of choice for selected young patients, especially teenage patients, to postpone total hip arthroplasty.

The 72-kDa Microtubule-Associated Protein from Porcine Brain

Abstract: A microtubule‐associated protein (MAP) with a molecular mass of 72‐kDa that was purified from porcine brain by using its property of heat stability in a low pH buffer was characterized. Low‐angle rotary shadowing revealed that the 72‐kDa protein was a rodlike protein ∼55–75 nm long. The 72‐kDa protein bound to microtubules polymerized from phosphocellulose column‐purified tubulin (PC‐tubulin) with taxol and promoted the polymerization of PC‐tubulin in the absence of taxol. Microtubules polymerized by the 72‐kDa protein showed a tendency to form bundles of several microtubules. Quick‐freeze, deep‐etch electron microscopy revealed that the 72‐kDa protein formed short crossbridges between microtubules. We performed peptide mapping to analyze the relationship of the 72‐kDa protein to other heat‐stable MAPs, and the results showed some resemblance of the 72‐kDa protein to MAP2. Cross‐reactivity with a monoclonal anti‐MAP2 antibody further suggested that the 72‐kDa protein and MAP2 are immunologically related. To study the relationship between the 72‐kDa protein and MAP2C, a smaller molecular form of MAP2 identified in juvenile rat brain, we prepared the 72‐kDa protein from rat brain by the same method as that used for porcine brain. The fact that the 72‐kDa protein from juvenile rat brain was also stained with our monoclonal anti‐MAP2 antibody also suggested that the 72‐kDa protein is an MAP2C homologue of the porcine brain.

Early radiological changes and biological reaction of primary osteoarthrosis in the hip

We followed the natural course of primary osteoarthrosis in the hip radiologically for more than 3 years, and analyzed the biological reaction (osteoblastic and osteoclastic response) to the condition with reference to the early radiological changes. Twenty hips in 14 patients were involved in this study. The average age of the patients was 62 years, and the average follow-up period was 5.9 years. Early changes at first presentation were classified according to the site of the joint space narrowing, as upper (11 hips), lateral (6 hips), or medial type (3 hips). The biological reaction at final review was classified according to the extent of osteophytosis, as hypertrophic (7 hips), intermediate (11 hips), or atrophic type (2 hips). All but one of the 11 hips with upper-type early change showed intermediate reaction. All 6 hips with lateral-type early change showed hypertrophic reaction. Of the 3 hips with medial-type early change, 2 showed atrophic reaction. We conclude that the site of joint space narrowing in the early stage is a factor that affects the ensuing biological reaction to primary osteoarthrosis in the hip.