[Prevalence and clinicopathological characteristics of giant cell tumors]. / Prevalencia y características clínico-patológicas del tumor de células gigantes.

The frequency of giant cell tumors reported in the literature is very variable. Considering that our population has its own features, which distinguish it from the Anglo-Saxon and Asian populations, we think that both the frequency and the clinical characteristics of giant cell tumors in our population are different. The major aim of this paper was to determine the frequency and clinicopathological characteristics of giant cell tumors of the bone. A cross-sectional descriptive study was conducted of the cases diagnosed at our service as giant cell tumors of the bone from January to December 2013. The electronic clinical records, radiologic records and histologic slides from each case were reviewed. Giant cell tumors represented 17% of total bone tumors and 28% of benign tumors. Patients included 13 females and 18 males. The most frequent locations of giant cell tumors were: the proximal tibia, 9 cases (29%), and the distal femur, 6 cases (19%). Forty-five percent of giant cell tumors were associated with aneurysmal bone cyst (ABC) (14 cases) and one case (3%) was malignant. The frequency of giant cell tumors in this case series was intermediate, that is, higher than the one reported in Anglo-Saxon countries (usually low), but without reaching the frequency rates reported in Asian countries (high).

La frecuencia del tumor de células gigantes reportada en la literatura es muy variable. Tomando en cuenta que nuestra población presenta características propias, diferentes a las poblaciones anglosajona y asiática, consideramos que tanto la frecuencia como las cualidades clínicas del tumor de células gigantes en nuestro país son distintas. El objetivo principal de este trabajo fue determinar la frecuencia y las características clínico-patológicas del tumor de células gigantes de hueso. Se realizó un estudio transversal y descriptivo de los casos diagnosticados en el servicio como tumor de células gigantes de hueso durante el período comprendido de Enero a Diciembre de 2013. En cada caso seleccionado, se revisó el expediente clínico electrónico, el expediente radiológico, así como también las laminillas. Los tumores de células gigantes comprendieron 17% de los tumores óseos en general y 28% de los tumores óseos benignos. Hubo 13 mujeres y 18 hombres. Los lugares de presentación más frecuentes del tumor de células gigantes fueron: tibia proximal, nueve casos (29%) y fémur distal, seis casos (19%). Cuarenta y cinco por ciento de los tumores de células gigantes se encontraron asociados con quiste óseo aneurismático (14 casos) y un caso (3%) fue maligno. En esta serie, el tumor de células gigantes presentó una frecuencia intermedia; es decir, una frecuencia mayor a la reportada en países anglosajones (con frecuencia baja), aunque sin llegar a ser igual a la de los países asiáticos (frecuencia alta).

[Treatment and reconstruction of bone tumors of the with a RIMAG unconventional prosthesis]. / Tratamiento y reconstrucción en tumores óseos del húmero con prótesis no convencional tipo RIMAG.

INTRODUCTION: Conservative surgery and reconstruction with an unconventional prosthesis are indicated for tumors of the humerus without neurovascular compromise, as they help preserve shoulder, elbow and hand function. The humerus is the third most frequent site of benign, aggressive, malignant and metastatic tumors that cause functional limitation or limb loss. MATERIAL: Patients with a bone tumor of the humerus without neurovascular involvement that met the inclusion criteria. Unconventional, uncemented RIMAG prosthesis with diaphyseal fit and locking bolts. METHODS: 39 patients with intraarticular type I tumors according to the Malawer and Enneking classification were treated with tumor resection and reconstruction with an unconventional prosthesis and soft tissues. RESULTS: Patients enrolled included 18 females and 21 males ages 12-72 years with tumors such as: giant cell tumors (14), osteosarcomas (7), metastasis (7), chondrosarcomas (6), Ewing's sarcomas (2), chondroblastoma (2) and aneurysmatic bone cyst (1). Twelve patients died due to systemic disease and the remaining patients survived. Surgical margins were broad, with humeral resection between 100 and 230 mm. Functional results were assessed according to the Muscoloskeletal Tumor Society score as 13 excellent, 16 good, 5 failures and 5 poor. DISCUSSION: The resection level does not restrict the placement of this prosthesis, which permits future revisions. An appropriate result depends on the resection size and the preserved shoulder musculature and it is not limited by the size of resection, thus improving patients' disability.

[Efficacy of the RIMAG unconventional hip prosthesis in patients with primary bone tumors, metastasis and non-tumor osteoarticular losses]. / Eficacia de la prótesis no convencional para la cadera tipo RIMAG en pacientes con tumores óseos primarios, metástasis y pérdidas osteoarticulares no tumorales.

OBJECTIVE: To assess the functional efficacy of the RIMAG unconventional hip prosthesis in cancer and non-cancer patients. MATERIAL AND METHODS: Functional analysis of 38 patients with RIMAG arthroplasty, using the Musculoskeletal Tumor Society Scoring System and including the following: functionality versus histologic diagnosis (5 malignancies, 3 metastases, 14 giant cell tumors (GCT), 8 with other benign tumors, and 8 had no tumor), age (40.4 +/- 19.1 years), sex (24 females, 14 males), postoperative follow-up (34.7 +/- 31.3 months). Analysis of intraoperative, immediate and late complications, time to weight bearing, gait and work or social reintegration were also assessed. RESULTS: Global mean of ideal functionality was 65.6 +/- 23.2%. Age was negatively correlated with the functionality rate (r = -0.507, p = 0.001); significant difference with the histologic diagnosis: malignant tumors 54.8, metastasis 58.6, giant cell tumor 25.6, other benign tumors 34.2, non-tumor causes 56.6 (p = 0.001). When functionality means were adjusted for age with a covariance analysis, better percentages were found for benign tumors (79.2 +/- 6.8%) and giant cell tumors (76.4 +/- 6.3%), less functionality for non-tumor causes (45.7 +/- 7.6%), and intermediate percentages for malignant tumors and metastasis (p = 0.03). Intraoperative complications occurred in 4 cases (28.6%), immediate in 3 (7.8%), late in 15 (39.4%); 62.5% of patients started immediate weight bearing, 92.1% resumed their usual activities after surgery. CONCLUSIONS: The reconstruction of the proximal femur with RIMAG is a safe and reliable treatment option, with complication rates below the ones reported in the literature. Satisfactory results were obtained, with high functional rates for benign tumors, and low rates in older patients, malignant tumors and metastasis.

[Long-term results of the treatment of a giant cell tumor with en-bloc resection and unconventional hip arthroplasty with ipsilateral knee arthrodesis. Clinical case report and literature review]. / Resultados a largo plazo del tratamiento del tumor de células gigantes mediante resección en bloque y artroplastía no convencional de cadera con artrodesis de rodilla ipsilateral. presentación de caso clínico y revisión de la literatura.

Giant cell tumor (GCT) is an aggressive benign neoplasia that accounts for 5% of primary bone tumors and 20% of all benign bone tumors. It appears almost exclusively after skeletal maturation, between 20 and 40 years of age, and is predominant among females. We report the case of a 39 year-old male patient who in 1988 sustained a left hip fracture in a pathological area. On July 20, 1988 he underwent excisional biopsy and curettage; on January 13, 1989 broad resection and arthrodesis of the left hip were performed with a cobra plate. The histopathologic diagnosis was GCT. On October 2, 1990 the cobra plate was removed due to fatigue. The patient was referred to our service with a floating hip joint and left knee anchylosis. On February 11, 1991 he underwent unconventional hip arthroplasty with a long stem up to the femoral supracondylar area. On February 2, 1995 the implant was removed due to fatigue. On February 16, 1995 an unconventional prosthesis with a long stem was re-implanted for knee arthrodesis. Final shortening was 10 cm. On November 17, 2010 he had radiographic signs of acetabular loosening and fatigue of the arthrodesis stem. On March 17, 2011 the unconventional prosthesis was removed, en-bloc resection of the distal femur was performed, and acetabular and femoral components were put in place. He is currently painless, walks with crutches and has 5.5 cm of shortening. The proximal femur is an infrequent site for GCT. Controlling the neoplasia and limb preservation are the major challenges that orthopedic surgeons and patients face. There are only a few published papers on revision of unconventional arthroplasty. There are no cases published on unconventional hip arthroplasty with ipsilateral knee arthrodesis.

[Periacetabular pelvic reconstruction for chondrosarcoma with autograft of the proximal femur]. / Reconstrucción periacetabular de la pelvis por condrosarcoma con autoinjerto de tercio proximal de fémur.

INTRODUCTION: Chondrosarcoma is a malignant tumor of chondroid matrix-producing cells; based on its frequency, it is the second most common malignant bone tumor (10-20%) and responds poorly to chemo- and radiotherapy. It is infrequent in the pelvis. It has a rapid growth potential. The indicated treatment is broad resection with tumor-free margins. Pelvic reconstruction after resection is controversial. The current management of musculoskeletal neoplasias has a two-fold purpose. First of all, controlling the neoplasia by means of surgeries with cancer-free margins and, second, performing procedures for the reconstruction of the involved segment achieving limb preservation with maximum functionality. OBJECTIVE: Intrapelvic reconstruction with the proximal third of the ipsilateral femur in a patient with a chondrosarcoma in Enneking-Dunham's zone II. And placement of an unconventional femur prosthesis. CLINICAL CASE: We present herein the case of a 58 year-old male, with a lytic lesion of the right acetabulum. The patient completed the diagnostic protocol, and the biopsy result was dedifferentiated chondrosarcoma. CONCLUSION: The purpose of the surgical technique is to use the proximal third of the femur as a novel reconstruction alternative with massive autograft for tumor lesions located in Enneking-Dunham zone II.

[Unconventional hip arthroplasty for a 15-year-old benign bone fibrous histiocytoma in a pediatric patient]. / Artroplastía no convencional de cadera por histiocitoma fibroso benigno óseo en un paciente pediátrico con 15 años de evolución.

INTRODUCTION: Benign fibrous histiocytoma is a rare tumor with very stringent radiologic and histopathologic criteria. It accounts for approximately 1% of all the benign bone tumors. It may be located in both the soft tissues and bone. Its usual location is the shaft, the epiphyseal end of the long bones, the pelvis and the ribs. The age range of presentation is very broad, from 5 to 75 years; it occurs more frequently in young adults. It is rare in children. CASE: Female, 27 year-old patient who presented at 10 years of age with a tumor in the right proximal femur, which was diagnosed as benign fibrous histiocytoma. She underwent surgical en bloc resection and unconventional arthroplasty with a RIMAG prosthesis. She did fine, had no alterations of implant instability and bone quality. She is developing properly, with symmetry of the extremities and appropriate mobility. DISCUSSION: There are only a few articles addressing subtotal and total hip arthroplasty in pediatric ages. There are reports in adolescents ranging from infection to loosening, periprosthetic fracture, revision and, generally speaking, implant failure. However, we did not see this type of complications in this case, and the patient received appropriate management.

Prótesis tumoral no convencional bloqueada para cadera / Interlocking non-conventional tumoral prosthesis for the hip

Se revisan 10 pacientes operados de la articulación de la cadera y reconstruidos con una prótesis no convensional bloqueada para cadera. Se evalúan con revisión de expediente clínico y radiológico en el periodo comprendido de enero de 1991 a enero de 1996. Etapificados con la clasificiación de Enneking, se les realizó abordaje lateral y resección amplia. Se realizó miodesis del glúteo medio al tensor de la fascia lata preservando la abducción. Se obtuvieron 4 tumores de células gigantes, 2 metástasis, 1 histicitoma fibroso maligno de bajo grado, 1 condrosarcoma, 1 fibroma no osificante atípico, 1 fractura subtrocantérica en pseudoartrosis. La magnitud de la resección promedio fue de 15 cm. La reconstrucción se realizó con la prótesis no convencional con espaciador y sistema bloqueante con pernos. Ha existido una complicación por elongación del nervio ciático mayor y una ruptura del tallo endomedular por palanca. Hasta el momento no existen complicaciones clínicas, radiológicas o de estabilidad debidas al implante. Dos pacientes han fallecido por su evolución neoplásica y uno por infarto cardiaco