José Cañadell

Distraction osteogenesis of the lower extremity with use of monolateral external fixation : A study of two hundred and sixty-one femora and tibiae

We reviewed the results of distraction osteogenesis of 114 femora and 147 tibiae that had been lengthened to treat a variety of diagnoses. The femora had been lengthened an average of eleven centimeters (range, 3.5 to 17.0 centimeters), or 48 per cent (range, 8 to 86 per cent) of the original femoral length. The average total time for the treatment of the femora (use of the fixator and any subsequent immobilization) was 257 days (range, 105 to 420 days). There were 114 complications related to the femoral lengthenings, which led to eighty-seven additional operations. The tibiae were lengthened an average of nine centimeters (range, 3.0 to 15.6 centimeters), or 41 per cent (range, 9 to 100 per cent) of the original tibial length. The average total time for the treatment of the tibiae was 268 days (range, 110 to 497 days). There were 196 complications related to the tibial lengthenings, which led to 219 additional operations. The Achilles tendon was lengthened during or after seventy-three (50 per cent) of the tibial lengthenings. The femoral lengthenings that were performed to treat a limb-length discrepancy were associated with significantly higher rates of complications overall (p = 0.010) and additional operations (p = 0.023) for each percentage of length gained than those that were performed to treat achondroplasia or another skeletal dysplasia. The femoral lengthenings that were performed to treat short stature (of an endocrine or idiopathic etiology) were also associated with higher rates of complications overall and additional operations than those performed to treat skeletal dysplasias, but the rates were lower than those for lengthenings performed to treat limb-length discrepancy. The rate of complications overall associated with femoral lengthening in patients who were fourteen years old or more was significantly higher than that associated with lengthening in patients who were less than fourteen years old (p = 0.047). Femoral lengthening through the metaphysis was associated with significantly higher rates of complications overall (p = 0.031) and additional operations (p = 0.042) for each percentage of length gained than femoral lengthening through the diaphysis. The tibial lengthenings that were performed to treat Turner syndrome and idiopathic short stature were associated with significantly higher rates of complications overall (p = 0.026) and additional operations (p = 0.003) for each percentage of length gained than those performed to treat skeletal dysplasias. The rate of joint-related problems (p = 0.044) and that of additional operations (p = 0.053) after tibial lengthening in patients who were fourteen years old or more were significantly higher than those rates after tibial lengthening in patients who were less than fourteen years old. The site of the tibial osteotomy did not affect the rate of complications or additional operations. The femoral healing indices (in terms of both days per centimeter [p = 0.002] and days for each percentage of length gained [p = 0.019]) were significantly higher in the patients who were fourteen years old or more than in those who were less the fourteen years old. These values could not be used to predict an increase in the complications because of poor bone formation. The results of the present review suggest that the use of healing indices to gauge the final outcome of distraction osteogenesis is questionable; we were unable to discern significance or clinical importance from appropriately adjusted values.

Removal of metaphyseal bone tumours with preservation of the epiphysis. Physeal distraction before excision

In immature long bones, radical excision of malignant tumours of the metaphysis may necessitate sacrifice of the adjacent epiphysis. To preserve the adjacent joint while allowing a safe margin of excision, we used physeal distraction before removing the tumour. From July 1984 to August 1992, we operated on 20 patients by this method. After a mean follow-up of 54 months there was no local recurrence in the epiphyseal region. Three patients had developed pulmonary metastases.

Scoliosis Induced by Medullary Damage: An Experimental Study in Rabbits

To date, there have been no reports of experiments designed to induce scoliosis by direct damage of different areas of the spinal cord. In a series of rabbits with medullary damage, the authors attempted selectively to interrupt the pathways that mediate proprioceptive input. Unilateral lesion of th

Indications for epiphyseal preservation in metaphyseal malignant bone tumors of children : Relationship between image methods and histological findings

We compared several image methods in the evaluation of the possible physeal effect in 47 osteosarcomas and 18 Ewings sarcomas in children. The minimal follow-up was 3 years (range, 3-17). In the histological study, the physis was affected in 53% of the cases. We correlated the histological findings and the findings from the different image methods. There were more false-positive than false-negative results, and in the computed tomography and magnetic resonance imaging (MRI) studies, there were no false negatives. The accuracy of MRI (predictive positive value plus predictive negative value) was the best (90.3%), and it is the technique that we prefer. According to these findings, we can safely preserve the epiphysis in cases of metaphyseal tumors showing no contact between the tumor and the growth plate in the MRI images. If the tumor shows contact with part of the physis, it is also possible to preserve the epiphysis.

Lymphocyte response to polymethylmethacrylate in loose total hip prostheses

We investigated the lymphocyte-mediated immune response to polymethylmethacrylate bone cement in 26 patients who had revision surgery for aseptic loosening of cemented total hip arthroplasties, at a mean time of seven years after the first replacement. We studied eight patients with cemented total hip arthroplasties which were not loose as controls. Patch tests to polymethylmethacrylate bone cement were positive in 13 patients with loosening, and these patients had higher lymphoblast transformation values against polymethylmethacrylate bone cement patients with a negative skin reaction (p < 0.01) or those in the control group (p < 0.001). Specific monoclonal antibodies were used to assess the percentage of certain cells of the immune system according to their cluster of differentiation (CD). There was a higher number of total T and B lymphocytes (CD2 and CD22) and interleukin-2 receptor-positive lymphocytes (activated cells, CD25) in patients with loose prostheses. More CD25 lymphocytes were found in patients with positive patch tests. The activation of the lymphocyte-mediated immune response was not related to the presence or absence of aggressive granulomatous lesions at the cement-bone interface.

Intercalary bone allografts 23 tumor cases followed for 3 years

From 1987 to 1991, 26 patients with malignant bone tumors (osteosarcoma, Ewings sarcoma, chondrosarcoma and malignant fibrous histiocytoma) in the diaphysis or metaphysis of long bones have been treated by chemotherapy, radiotherapy and intercalary bone allograft replacement after resection. The mean follow-up was 3 years in 23 patients, 2 died from tumors, and 1 had an amputation because of local recurrence. Allograft incorporation in 11 metaphyseal anastomoses was excellent in all cases. In the 23 diaphyseal anastomoses there were 6 non-unions. Other complications were deep infection in 3 cases, leg length discrepancy in 2 and allograft fracture in 2. Function became satisfactory in 14 cases.

Fractures of allografts used in limb preserving operations

Summary. One hundred and thirty-seven allografts used since 1986 in limb preserving operations for malignant bone tumours were reviewed. The follow up was longer than two years. There were fourteen fractures (10.2%) in twelve patients at a mean time of 22 months from the operation. Most of them were in the metaphyseal area and were related to perforations of the allograft made for stabilisation with plates, for tendon and ligament reattachment, or any other hole in the allograft. Fractures occurred always after the allograft-host junction was united. Healing was achieved in 7 cases by internal fixation with autologous bone grafting in a mean of 5 months. In cases of multiple fractures of the allograft, the graft was exchanged. We recommend using intramedullary fixation in order to reduce the incidence of allograft fracture, and the use of internal fixation, with intramedullary whenever possible, and autologous bone grafting to achieve consolidation of the fractures.Résumé. Nous présentons notre expérience 137 allogreffes avec un recul moyen supérieur à deux ans, utilisées depuis 1986 dans la chirugie reconstrutive des sarcomes osseux. Nous avons eu quatorze fractures chez douze patients (10.2%) après un délai moyen Post operative de 22 mois. La plupart étaient métaphysaires en relation avec les perforationś nécessaries pour l’ostéosynthése, pour attaches tendinouses ou d’autres trous sur l’allogreffe. La fracture de l’allogreffe s’est toujours produit nécessaires pour e après a consolidation avec l’os receveur. La consolidation fut obtenue chez sept patients, après ostéosynthése avec autogreffe, en cinq mois de moyenne. En cas de fractures multiples de l’allogreffe, celle-ci fut remplacée. Les auteurs recommandent l’utilisation des clous endomédullaires afin de réduire la fréquence des fractures, ainsi que l’ostésynthese interne (endomédullaire si possible) associée a une autogreffe afin d’obtenir la consolidation des fractures.

Experimental physeal distraction in immature sheep

An experimental study on physeal distraction was carried out in the distal femur of 45 two-month-old lambs for the purpose of identifying the basic mechanism of lengthening as well as assessing growth cartilage viability after lengthening. The animals were divided into three groups, each with three subgroups, according to the distraction rate employed (2 mm/day, 1 mm/day, 0.5 mm/day) and the time at which the animals were killed (end of lengthening, 1.5 months postlengthening, and at six months of age). Another group of three animals whose femurs were lengthened at a rate of 0.5 mm/day was killed ten days postoperatively. Roentgenologic, specimen measurements, and histologic studies were performed on all animals. The results obtained showed that the basic mechanism for lengthening is the production of a physeal fracture between degenerative and calcified layers; this finding was consistent. It was also observed that the lower the rate of distraction employed, the greater was the short- and long-term viability of the growth cartilage. More specifically, optimal viability was observed when a distraction rate of 0.5 mm/day was employed.

Large Experimental Segmental Bone Defects Treated By Bone Transportation With Monolateral External Distractors

Monolateral frames were applied to five dogs and ten lambs for treatment of large segmental bone defects (LSBD) surgically induced in one of their femoral diaphyses. Reconstruction was attempted by bone transport, as developed by Ilizarov. Monolateral frames were used to minimize the draw-backs of Ilizarovs circular device. Radiographic, computed tomographic, and histologic studies were performed. The skin and soft tissues were not a major obstacle for the longitudinal migration of the screws during bone transport. Four months after the operations, healing and remodeling of the bone defect was always satisfactory. Histologically, the repair of the lengthened segment followed an intramembranous ossification pattern in its central areas and in the periphery as well. At the end of the experiment, the new induced bone had a virtually normal diaphyseal bone appearance. Bone transport for the treatment of experimental LSBD can be completed in monolateral frames.

Delayed distraction in bone lengthening improved healing in lambs.

We compared delayed distraction (DD) with immediate distraction (ID) in bone-lengthening. Open femoral diaphyseal osteotomy was performed on 24 three-month-old lambs, and external distractor fixators were applied. In the ID group (n 12), distraction commenced on the first postoperative day; in the DD group (n 12), distraction was delayed until the tenth day after surgery. In all the animals, the femur was lengthened by 2 cm at the rate of 1 mm/day. The animals were killed 1, 2, and 3 months postoperatively. Radiography and densitometry of the lengthened callus showed that DD, compared with ID, improved the quality of the callus with quicker, denser, and more homogeneous bone formation.