Journal of Musculoskeletal Research

The result of 27 Chiari pelvic osteotomy were analyzed to determine the efficacy of the operation in the treatment of subluxated and/or painful dysplastic hips. The length of follow-up ranged from 2 to 14 years. Eighteen patients had had developmental dysplasia of the hip; four sequelae of the septic hip; two, cerebral palsy and one had had poliomyelitis. The osteotomy can be done by power saw and osteotome. A large threaded K-wire was used for internal fixation. Bone graft was necessary even with the displacement of more than 50%. The overall result were: 12, excellent; 8, good; 5, fair; and 2 poor. In 11 patients, the osteotomy had to be displaced more than 50% to provide good coverage of the femoral head. There were no major complications such as sciatic nerve injury or delayed union. This procedure is most suited for the patient with painful hip dysplasia in whom a concentric reduction is not possible.

Eighty cases of early DDH treated with Pavlik harness over a 10-year period in one centre was followed up for a minimum of 2 years with a mean of 6.5 years. Sixty-five percent of the patients presented to the clinic before the age of 4 weeks, and 10% after 12 weeks. Sixty percent presented clinically as dislocated reducible hip, 25% as dislocated non-reducible hip, and 15% as dislocatable hip. Static and dynamic ultrasonographic grading revealed 65% as pathological hip and 35% as normal. Clinical and ultrasonographic assessment revealed that 2 weeks after commencement of the Pavlik Harness treatment, 78% of the hips were reduced and this increased after 4 weeks, to 91.2%. The most significant factors affecting the outcome were the age at the start of treatment and the clinical type of hip. A 95% success reduction rate was achieved for those treated before the age of 8 weeks and only 50% for those after this age. Ninety-five percent of the dislocated reducible hips and 100% of the dislocatable hips were successfully reduced. Of the initial dislocated irreducible hips, only 50% were successfully reduced. At the final follow-up, the clinical and radiological assessment showed an overall success rate of 84%. Avascular necrosis was only found in 1 case (1.25%).

Developmental dislocation of the hip is an important orthopedic condition whose early diagnosis and treatment greatly improves the life of a patient with the condition. Despite a worldwide focus on early diagnosis and treatment, many children and adolescents present with residual hip dysplasia. This group includes those that have not had prior diagnosis or treatment and often present in adolescence, as well as those who have been treated nonoperatively and yet continue to have residual dysplasia.

Decisions determining when hip dysplasia should be surgically corrected have traditionally been dependent upon two-dimensional images (plain radiographs) to analyze the nature and degree of residual deformity. To better understand residual hip dysplasia in children, we have utilized three-dimensional computerized tomographic (3-D CT) methods to evaluate the pathoanatomy of hip dysplasia in children. Careful analysis of these images has allowed us to more fully understand the nature of residual hip dysplasia and to better plan corrective hip osteotomies designed to improve the longevity and function of the hip joint.

Developmental dysplasia of the hip can result in significant morbidity both in childhood and later in adult life. Early diagnosis enables better results to be obtained with fewer complications, while delayed diagnosis can lead to prolonged treatment with less satisfactory outcome.

A Neonatal Hip Screening program for DDH has been in place in the National University Hospital, Singapore since December 1989. Our program is run by consultant neonatologists and consultant paediatric orthopaedic surgeons. All neonates seen with DDH are followed up for a minimum of 1 year with ultrasonography and X-rays.

Our results show an incidence of dislocated hips of 4.7 per 1000 live births. The incidence of neonates with acetabular dysplasia as defined by an Acetabular Index of > 30° is 16.8 per 1000 live births.

The early diagnosis and treatment of hip dislocation is important for the development of a normal acetabulum. Neonatal Hip Screening programs have been shown to be effective in the early diagnosis, resulting in successful outcome of treatment and reduction of economic costs in the management of DDH.

The finding of a significant incidence of DDH in our population and the successful management after early diagnosis in our study have vindicated the establishment of our hip screening program.

An extractable bone-inducing agent has recently been identified in freeze-dried preparations of Saos-2 cultured human osteosarcoma cells. Although not all osteoinductive components of Saos-2 cell extracts have been identified, we have shown that Saos-2 cells express high levels of mRNA for bone morphogenetic proteins (BMPs)-1,2,3,4 and 6. Any or all of these BMPs (plus possible unknown factors) may be involved in ectopic bone induction, and may act as paracrine agents, conveying morphogenetic information to juxtaposed osteoprogenitor cells. Our objectives in this study were: 1) to determine whether Saos-2 cells secrete BIA into their culture medium; and 2) if secreted, to determine whether released bone-inducing agent is soluble and/or particulate and contains BMPs. Saos-2 cells were grown to confluence, and then overlaid with serum-free DMEM culture medium for 48 hours. The serum-free conditioned medium was then decanted and filtered through 0.45μ pore-size filters to retain any vesicles or other particulates released by the cells. Particulate protein retained on the 0.45μ filter (designated "retentate") was extracted into 6M urea and bioassayed for bone-inducing activity in Nu/Nu mice, along with soluble media protein that had passed through the 0.45μ filter (designated "filtrate") plus freeze-dried Saos-2 cells from which conditioned the culture medium was obtained. Results indicate that the bone-inducing agent of Saos-2 cells is not only retained by the cells, but is also secreted in both soluble and particulate forms into serum-free conditioned medium. Bone-inducing activity (per mg protein) is more concentrated in the particulate fraction, which is shown by electron microscopy to contain a mixture of vesicles (similar to matrix vesicles) plus electron dense granules (resembling ribosomes) and 10 mM microfilaments (of possible collagenous or cytoskeletal origin). BMP-1,2,3,4,6 and 7 were detected by western blots in both the soluble and particulate fractions of conditioned medium. Thus, it is indicated that Saos-2 cells secrete an osteoinductive factor which may function in vivo as a paracrine morphogenetic agent.

This study focused mainly on the long-lasting effectiveness of Graf band stabilization system on the stabilized lumbar motion segment together with the band fate and the final outcome. Graf soft stabilization operation was carried out to suppress the forward flexion and rotatory instability. Fifty-one patients were subjected to this study. Forty-five had pure forward flexion instability preoperatively. Among the 51 patients, 20 were irreducible mild spondylolisthesis and 8 reducible mild spondylolisthesis; 17 excessive flexion angular motion; one disc disease with mild stenotic symptoms; and 5 post-laminectomy instability.

In this series, good or excellent results were obtained in 40 cases (78.7%); fair in 4; no improvement in 4; and poor in 3. JOA lumbar score increased from 16 at preoperative exam to 26.5 on average at the final examination. In 3 cases screws were malpositioned. In 2 cases, mild transient drop foot developed, and spontaneous fusion occurred in one disc surgery patient. There was no implant loosening or breakage, and no overstretch and tear of bands or disengagement. There was no recurrence of segmental instability at the immobilized segment. Also, there were no adjacent joint problems.

In summary, the Graf procedure appears to be a good alternative to spinal fusion for the stabilization of the unstable segment with forward flexion instability.

We report our experience using the acetabulum-impacting total hip arthroplasty technique and describe the results of short-term follow up. This technique is new method of acetabular plasty for the patients with severe dysplastic hip.

In this study, we simplified the analysis of kinetic gait data using pattern recognition. Gait patterns were studied in 42 spastic children with cerebral palsy (age range: 3 to 17 years old), and 24 age- and sex-matched children. Gait analysis was performed using the DynoGraphy (CDG) system (Infortronic, Holland). The foot enrollment and the role of the heel or forefoot were assessed to form the gaitline. The bipedal phase was examined using a cyclogram, which is a cyclic characteristic formed by the changing position of the application point of the resultant normal force on a vertical supporting horizontal plane during motion. Based on the pattern recognition, the gait patterns of the subjects could be classified into 4 different patterns in both the gaitline and the cyclogram. The classification of the gait was parallel to the clinical evaluation of cerebral palsy obtained based on Minear's classification of daily activity (p<0.05). The correlation between the gaitline and cyclogram was also highly significant (p<0.05). The results of this study suggest that an automated pattern recognition program might provide an additional method for comprehensive gait evaluation in children with cerebral palsy.