[Design of an unconventional interlocked hip arthroplasty system (RIMAG) from Mexican femoral measurement]. / Diseño de una prótesis no convencional bloqueada para cadera (RIMAG) a partir de mediciones de fémures mexicanos.

The need in resolving massive bone losses in hip region caused by tumors, infections, trauma or failed arthroplasties in 17 years of the Bone Tumors Department of the National Rehabilitation Institute, Mexico City, and data obtained from different studies: 1) Biomechanic study of an unconventional hip arthroplasty system, 2) Tridimensional model of a human femur by the finite element method, 3) Biomechanical analysis of a system bone-implant for reconstruction of the proximal third of the femur by the finite element method, 4) Incidence of tumor and pseudotumor bone and soft tissue lesions of the hip, generated the project of designing an unconventional interlocked hip arthroplasty system for femur reconstruction. Two processes were done for adequate manufacturing and dimensioning: Anthropomorphometric study of Mexican femora; 2) Design of an unconventional hip arthroplasty system with the following characteristics: first, the arthroplasty system is constituted by an intramedullar stem, is fixated to femur with interlocking screws, this fixation method was inspired from the design of intramedullar nails of Dr. Fernando Colchero Rosas. The system has a second fixation system in the femur cut region, resolved by a fenestrated support introduced in the cortical wall. Once data was processed, the need for manufacturing 2 models was determined: 1) One for the proximal 11 cm of the femur and 2) other for the 12 distal cm. The height of interlocking screws, 2 models of intracortical proximal support (one fixated and one fixable with an expansible screw), were designed. Diameter, length of the stems, size of spacers and supports were determined for adequate interlocking fixation. We designed the instruments for assembling, impaction and orientation of the arthroplasty system. The system was presented to the Mexican Institute of Industrial Property, at March 15, 1996 and the patent was conceded April 19, 2007 (#245717).

[Muscle-aponeurotic aggressive fibromatosis management. 10 years of experience]. / Manejo de la fibromatosis musculoaponeurótica agresiva. 10 años de experiencia.

INTRODUCTION: This work presents clinical evolution and functional outcome of patients with histologic diagnosis of Muscle-aponeurotic aggressive fibromatosis in 10 years of follow up in the National Rehabilitation Institute. MATERIAL AND METHODS: We performed a descriptive, retrospective, cross sectioned clinical trial in the Bone Tumour Department. We reviewed the clinical and radiological files from 1996 to 2006. INCLUSION CRITERIA: both genres, any age, clinical and histological diagnosis. EXCLUSION CRITERIA: incomplete file, lost to follow up, other diagnosis. Elimination criteria: Death during trial period. Analyzed variables. Age, genre, occupation, birth place, school degree, anatomic situation, signs and symptoms, time of follow up, treatment, relapses. We used statistical computed system Excel 2007, with central trend descriptive variables. RESULTS: Eleven patients (mean age 24.36; SD 18.32, 1-61 years), 9 female (81.8%) 2 male; birth place: Mexico City 7 (63.63%), Puebla 1, Toluca 1, South Baja California 1 and Chiapas 1. Anatomic situation: Pelvis 6 (54.54%), thoracic and gluteus 3. Pain and presence of a mass 10 (90.9%), range of motion limitation 5, edema and erithema 1. Relapses 6 (55%). TREATMENT: broad resection 3 patients, marginal resection 6 patients, radical resection 2 patients. CONCLUSIONS: If clinical suspicion of Muscle-aponeurotic fibromatosis appears, one should start protocol work up: laboratory, radiographic assessment, nuclear medicine, biopsy and histologic and immune-histochemistry. One should perform broad resections aiming to preserve the most possible extremity tissue disease free.