DISTAL FEMUR HEMIEPIPHYSIODESIS IN KNEE RECURVATUM: A NEW SURGICAL TECHNIQUE.

Introduction: The genu recurvatum is characterized by a hyperextension deformity of the knee in the sagittal plane. Among its causes are conditions such as arthrogryposis, cerebral palsy, poliomyelitis, sequelae of tibial tuberosity fracture and some syndromes with generalized joint hypermobility. Treatment of this deformity can be challenging and, to date, aggressive methods such as femur or tibial osteotomies are the most used for its correction. Objective: This study aimed to describe a new surgical technique for correcting genu recurvatum. Methods: This is a prospective clinical study of children who underwent posterior hemiepiphysiodesis of the distal femur with transphyseal screws. Results: The approach proved to be safe and useful for genu recurvatum deformities, with femoral or articular apex. Conclusion: This approach shows great potential for correcting genu recurvatum in the developing skeleton, being an excellent alternative to the more aggressive methods currently used to treat this deformity. Level of evidence IV, Case Series.

Introdução: O joelho recurvato é caracterizado por uma deformidade em hiperextensão do joelho no plano sagital. Entre suas causas, estão condições como artrogripose, paralisia cerebral, poliomielite, sequelas de fratura da tuberosidade da tíbia e algumas síndromes com hipermobilidade articular generalizada. O tratamento dessa deformidade pode ser desafiador e, até o momento, métodos agressivos como osteotomias do fêmur ou da tíbia são os mais utilizados para sua correção. Objetivo: Descrever uma nova técnica cirúrgica de correção do genu recurvatum. Métodos: Estudo clínico prospectivo de crianças submetidas à hemiepifisiodese posterior do fêmur distal com parafusos transfisários. Resultados: A técnica se mostrou segura e útil para as deformidades em recurvato do joelho, com ápice femoral ou articular. Conclusão: Essa técnica apresenta grande potencial de correção do joelho recurvato no esqueleto imaturo, sendo uma excelente alternativa aos métodos mais agressivos atualmente utilizados para o tratamento dessa deformidade. Nível de Evidência IV, Série de Casos.

An investigation of the value of tridimensional kinematic analysis in functional diagnosis of lumbar spinal stenosis.

Diagnosis of lumbar spinal stenosis (LSS) is based on clinical examination and imaging. The aim of this study was to evaluate the influence of 3D gait analysis as a tool in the differential diagnosis of LSS. Fourteen patients participated in the study that consisted of three phases: (1) capture six gait cycles after rest, (2) walk on a treadmill for a maximum of 20 min, (3) capture six gait cycles after effort. From these data, the kinematic variables were compared with the perception of pain and the cross sectional area of the spinal canal as measured by magnetic resonance. Most of correlations were weak and showed that the most significant results are reported by the Gait Deviation Index (GDI). The Gait Deviation Index demonstrated moderate negative correlation with the perception of pain after effort was made by both limbs. This means that there is a significant decrease in the overall function of the lower limbs according to the increase in pain symptoms. This situation may be reflected in decreased cadence and speed beyond the times of single support for the left limb, and the balance of the right limb, as part of a strategy to protect against pain and imbalance. We found no correlation between gait and pain in the cross-sectional area of the spinal canal. Therefore, we believe that there is no advantage for the patient to make a 3-D gait analysis because the analysis does not add relevant information to clinical diagnosis.

Experimental evaluation of 3-dimensional kinematic behavior of the cruciate ligaments.

PURPOSE: The purpose of this study was to evaluate a low-cost and easily reproducible technique for biomechanical studies in cadavers. In this kind of study, the natural effect of loading of the joint and shear forces are not taken into account. The objective is to describe the plastic deformation of the ligaments into 3-dimensional space. METHOD: For 18 intact human cadaver knees, the cruciate ligaments were divided into 3 fiber bundles, the tibial or femoral fixation points were marked, and 2 perpendicular different x-ray exposures were performed, thus obtaining radiographs of spatial projections of the bundle in 3 anatomic planes (frontal, sagittal, and transversal). From the measurements made on the x-ray films, we obtained the average distance between the 2 fixation points of the cruciate ligaments on the tibia and the femur at 4 different flexion angles. RESULTS: The distance between the fixation points of the medial and lateral fiber bundles of the cruciate ligaments did not change significantly during movement. There were, however, significant variations (P < .05) in the distance between the fixation points of the posterior fiber bundles of the anterior cruciate ligament and the anterior fiber bundles of the posterior cruciate ligament. CONCLUSIONS: This technique was efficient for demonstrating the plastic deformability of the cruciate ligaments. The results proceeding from this type of study can assist in the planning of physical rehabilitation programs.