Effect of Intertrochanteric Femoral Derotational Osteotomy on Sagittal Plane Kinematic and Kinetic Study of the Hip and Pelvis in Spastic Cerebral Palsy: A Preliminary Report / 대한정형외과학회잡지

To evaluate the effect of intertrochanteric femoral derotational osteotomy(IFDO) on the sagittal plane kinematics and kinetics of the hip and pelvis in spastic cerebral palsy, we compared the preoperative and post-operative results of 3 dimensional gait analysis. Intertrochanteric femoral derotational osteotomy alone without psoas procedure was performed in 34 hips of cerebral palsy patients with increased femoral anterversion regardless of preoperative dynamic or static hip flexion contracture. Those who had other concomitant hip procedures were excluded. There were 24 diplegics and 10 hemiplegics. Mean age of the patients at the time of operation was 9.1 years (range, 4.9 to 22). They were divided into three subgroups according to the degree of dynamic hip flexion contracture; 13 patients with normal hip extension in terminal stance (group I), 13 patients with maximum hip extension in terminal stance between 0 and 15 degrees (group II), and 8 patients with maximum hip extension in terminal stance of more than 15 degrees (group III). The gait analysis included clinical assessment, video-taping, 3D-kinematics and kinetics, and dynamic EMG. Linear parameters of gait, kinematic parameters, sagittal plane hip moment parameters, and total hip energy parameters were compared. Postoperatively, cadence and double support time decreased, whereas walking velocity and stride length increased in all groups. Maximum and minimum pelvic tilt were improved in all groups. The range of pelvic tilt improved in all groups except group I. Hip flexion-extension curve shifted into extension in all groups. Marked improvement in maximum hip extension in stance and the range of hip motion were observed in all groups. The sum of extensor moment decreased, whereas that of flexor moment increased significantly in all groups. The conversion timing from extensor to flexor moment significantly improved in group I and II. The decrease of power generations of Hl and the increase of power absorptions of H2 were significant in all groups. However, there were no significant changes in power generation of H3 in all groups. The changes of peak power generation timing of H3 was not consistent among the groups. Femoral derotational osteotomy at the intertrochanteric level brings the lesser trochanter forward resulting in iliopsoas lengthening effect. We found significant improvement of the sagittal plane kinematics and kinetics of the hip and pelvis when IFDO alone was performed without psoas tenotomy. The psoas lengthening procedure may be considered secondarily at the time of hardware removal after full evaluation of the psoas lengthening effect.

The Effect of Distraction - Compression on the Fracture Healing in Rats with Osteoporosis / 대한정형외과학회잡지

This study is verifying the hypothesis that distraction followed by recompression may promote fracture healing of the osteoporotic bone on the assumption that distraction induces increased callus formation at the distracted gap and recompression results in fusiform callus, having biomechanically stronger fracture stiffness. Sixty-six Sprague-Dawley rats, in which osteoporosis were induced 6-8 weeks after oophorectomy, were separated into two groups. Group I was control group that had fracture healing by simple external fixation. Group II was experimental group that had fracture healing by monofocal distraction-compression. Radiomorphometric study revealed that there was significantly increased amount of callus and ensuing bone formation, which becehe obvious from 20 days after osteotomy in group II compared with group I. Biomechanical study also showed that tensile break strength was significantly higher in group II compared with group I with time. It is concluded that monofocal distraction-compression method may be one of the useful method to promote fracture healing of the estrogen deficient osteoporotic bone.

Developmental Coxa Vara / 대한정형외과학회잡지

Deveolopmental coax vara represents coax vara not present at birth but rather developing in early childhood, showing a progressive deterioration in the proximal femoral neck-shaft angle during growth. In order to determine the factors that could affect the results of corrective osteotomy, we evaluated the results of 15 developmental coax vara in 12 patients who had been treated with the femoral osteotomy at the Department of Pediatric Orthopedic Surgery, Seoul National University Children's Hospital, from February 1983 to March 1993. Of the 12 patients, there were 6 boys and 6 girls. Three patients had bilateral operations, 5 patients on the right, and the remaining 4 patients on the left. Average at the onset of symptoms was 4 years plus 5 months(range; from 1 year to 7 years plus 2 months), and average age at the tome of operation was 6 years plus 3 months(range; from 2 years plus 4 months to 10 years). We could obtain the following results: 1. Average post-operative loss of neck-shaft angle was 5% in the cases in which post-operative neck-shaft angle was converted more than 130 degrees, and was 8% in the cases in which post-operative neck-shaft angle was converted less than 130 degrees. 2. Loss of neck-shaft angle was higher during the first post-operative period, and was higher in cases in which the triangular osseous defect was persistent post-operatively. There was no correlation between the post-operative neck-shaft angle and disappearance of triangular osseous defect. 3. The femoral anteversion was converted 8.7 degrees to 27.2 postoperatively. 4. The premature arrest of the capital femoral physis was higher in cases in which the neck-shaft angle was less than 130 degrees postoperatively. 5. Leg length discrepancy, which was 2.1 cm preoperatively, did not change in cases in which the neck-shaft angle was more than 130 degrees postoperatively. However, it was converted to 3.3 cm in cases in which the neck-shaft angle was less than 130 postoperatively. 6. we could observe the femoral head deformity in 6 out of 7 cases in which the operation was performed after 7 years of age. We could draw the following conclusion based on our results: 1. We must correct the neck-shaft angle more than 130 degrees. 2. We could not equalize the leg length discrepancy by corrective osteotomy alone. 3. It may be reasonable to perform the corrective osteotomy before 7 years of age.

Steel's Gluteus Medius and Minimus Advancement for In-toeing in Spastic Cerebral Palsy / 대한정형외과학회잡지

In order to investigate the validity of the Steel's gluteus medius and minimus advancement, we reviewed 21 hips in 14 spastic cerebral palsy patients, who had advancement of the gluteus medius and minimus insertion for the correction of in-toeing gait between November 1985 and February 1992. The procedure was limited to those patients who had moderate to severe in-toeing gait with positive Steel's stretch reflex. There were eight boys and six girls. The average age at the time of surgery was 6.7 years(2.9 years-11.9 years). The procedure was performed on both hips in seven patients. Of the 14 patients, nine had diplegia, three hemiplegia, and two paraplegia. The average follow-up time was 4.3 years(1 year-8.5 years). In-toeing gait was converted to neutral or physiologic out-toeing gait in 17 hips(81%), excessive out-toeing in 2 cases(9.5%), and mild residual in-toeing in 2 cases(9.5%), Steel's stretch reflex, which was present in all cases preoperatively, disappered in 19 hips(90.5%) postoperatively, Abductor power, however, decreased from 4+ to 4− in average postoperatively, Among the 16 hips, which had no Trendelenburg sign or gait preoperatively, 8 hips(50%) showed positive Trendelenburg sign and gait postoperatively. In conclusion, Steel's gluteus medius and minimus advancement appears to be effective in the correction of in-toeing gait, but there is high risk of weakening the abductor power.