Takahiko Kitakoji

Distraction Osteogenesis of the Lower Extremity in Patients With Achondroplasia/hypochondroplasia Treated With Transplantation of Culture-expanded Bone Marrow Cells and Platelet-rich Plasma

Background: Longer treatment period in distraction osteogenesis (DO) of the lower extremity leads to more frequent complications. We have developed a new technique of transplantation of culture-expanded bone marrow cells (BMCs) and platelet-rich plasma (PRP) during DO to accelerate new bone formation. To assess the efficacy of this cell therapy, retrospective comparative study was conducted between the bones treated with BMC and PRP and the bones treated without BMC and PRP during DO in patients with achondroplasia (ACH) and hypochondroplasia (HCH). Methods: Fifty-six bones in 20 patients (ACH, 16; HCH, 4) that were lengthened in our hospital were divided into 2 groups. Twenty-four bones (femora, 12; tibiae, 12) in 11 patients (boys, 7; girls, 4) were treated with BMC and PRP transplantation (BMC-PRP group), whereas 32 bones (femora, 14; tibiae, 18) in 9 patients (boys, 3; girls, 6) did not undergo additional cell therapy (control group). The parameters, including the age at operation, the increase in length, and the healing index, were compared between the 2 groups. The clinical outcome was also compared between the femoral and tibial lengthenings. Results: Bone marrow cells (average number, ± SD, 3.2 ± 1.37 × 107 cells) and PRP (average platelet concentration ± SD, 2.36 ± 0.57 × 106 cells/&mgr;L) were transplanted. Although there were no significant differences in the age at operation and the length gained between the 2 groups, the average healing index of the BMC-PRP group (27.1 ± 6.89 d/cm) was significantly lower than that of the control group (36.2 ± 10.4 d/cm) (P = 0.0005). The femoral lengthening showed significantly faster healing than did the tibial lengthening in the BMC-PRP group (P = 0.0092). Conclusions: Transplantation of BMC and PRP shortened the treatment period by accelerating new bone regeneration during DO of the lower extremity in patients with ACH and HCH, especially in the femoral lengthening. Level of Evidence: Therapeutic studies, level III (retrospective comparative study).

Distraction osteogenesis enhanced by osteoblastlike cells and collagen gel

Femoral distraction was done in rats to determine whether the injection of osteoblastlike cells with collagen gel into the distracted callus was useful for new bone formation. The cells were obtained from the femoral marrow of Sprague-Dawley rats and cultured for approximately 3 weeks. These rats were divided into four groups. The rats in Group A received injections of physiologic saline, those in Group B received injections of collagen gel, those in Group C received injections of cells, and those in Group D received injections containing a mixture of cells and collagen gel. The distracted areas were harvested and evaluated by histologic analysis, radiography, three-point bending testing, and the weight of femoral ash. Histologic evaluation did not show an immunoreaction between the donor and recipient. Radiographs showed that Group D had the most callus, and the fracture strength in this group as determined by the three-point bending test was higher than in Group A at 2, 4, and 6 weeks after elongation was completed. Group D showed a significant difference in the ash weight of the distracted femurs at 2 weeks. The current study showed that osteoblastlike cells with collagen gel promoted new bone formation in the distracted gap, and shortened the consolidation period.

Which is a better method for perthes' disease : Femoral varus or salter osteotomy?

The optimum surgical treatment of patients with Perthes’ disease has not been decided. We compared the clinical and radiographic results at skeletal maturity of the femoral varus osteotomy and the Salter innominate osteotomy for treatment of patients with Perthes’ disease. Treatment in 46 patients was by femoral varus osteotomy and in 30 patients by Salter innominate osteotomy. There were no significant differences between the two groups. The clinical results were similar in the two groups except for scarring after surgery, which was more prominent in the femoral varus osteotomy group. There was no significant difference in the sphericity of the femoral head and congruity of the hip between the two groups. However, coverage of the femoral head by the acetabulum, the neck-shaft angle, and the articular-trochanteric distance were closer to normal in the Salter innominate osteotomy group. We think that the Salter innominate osteotomy is the better treatment for patients with Perthes’ disease to decrease residual problems such as coxa vara, trochanteric prominence, poor acetabular coverage, and the surgical scar. Level of Evidence: Therapeutic study, Level IV (case series-no, or historical control group)

Femoral varus osteotomy in Legg-Calvé-Perthes disease: points at operation to prevent residual problems.

We analyzed at skeletal maturity the radiographic results of 46 patients with unilateral Legg-Calvé-Perthes disease (LCPD) who were treated with femoral varus osteotomy (FVO) with special attention to proximal femoral growth. In 30 patients, leg-length discrepancy (LLD) and alignment change in the leg also were examined. The postoperative femoral neck shaft angle (FNSA) was not related to the result on Stulbergs criteria, but the postoperative acetabulum head index (AHI) was. Trochanteric prominence remained on the affected side in spite of an improvement in FNSA. LLD did not depend chiefly on FVO itself. The alignment of the leg on the affected side showed a tendency to valgus, which occurred to correct the mechanical axis displaced medially by the FVO. Along with an FVO for LCPD, some additional operative technique should be performed to prevent trochanteric prominence and medial displacement of the distal fragment to prevent genu valgum.

Soft-tissue interposition after closed reduction in developmental dysplasia of the hip: THE LONG-TERM EFFECT ON ACETABULAR DEVELOPMENT AND AVASCULAR NECROSIS

We reviewed 98 children (133 hips) with developmental dysplasia of the hip who underwent arthrography immediately after closed reduction by overhead traction. We followed the patients to skeletal maturity to investigate whether soft-tissue interposition influences acetabular development and avascular necrosis over the long term. The shape of the limbus and the thickness of the soft-tissue interposition at the acetabular floor, as shown on arthrograms at the time of reduction, were not directly related to the final radiological results or to the incidence of avascular necrosis. Even if marked soft-tissue interposition was found on the initial arthrogram, spontaneous disappearance was noted in 71% up to the age of five years. The final radiological results showed no difference between those in which the interposition disappeared and those with none at the time of closed reduction. However, the requirement for secondary surgery at the age of five years was significantly higher in those with more than 3.5 mm of soft-tissue interposition. In the no-disappearance group (group C) further operation was necessary in 100% and the results were significantly worse at maturity according to Severins classification. We suggest that the indications for open reduction should not be based solely on the arthrographic findings at the time of closed reduction.

A histological and ultrastructural study of the iliac crest apophysis in Legg-Calve-Perthes disease.

Background: Legg-Calve-Perthes disease (LCPD) is a common hip disorder in children characterized by avascular necrosis of the proximal capital femoral epiphysis. The underlying etiology of the vascular disturbance is still unknown, but it is suggested that LCPD may be a part of a generalized constitutional disorder associated with growth disturbance of bone and cartilage tissue. In this study, the biopsy specimens of the iliac crest apophysis from LCPD patients were examined histologically and ultrastructurally to determine preexisting generalized abnormalities of endochondral ossification. Methods: Iliac crest apophysis cartilage was taken during Salter innominate osteotomy from 11 children (8 boys and 3 girls) with LCPD at an average age of 7.8 years. As controls, the samples were also obtained from 10 children (2 boys and 8 girls) at an average age of 6.3 years undergoing Salter osteotomy due to residual acetabular dysplasia after reduction of developmental dysplasia of the hip. Each iliac crest apophysis specimen was examined histologically (Toluidine blue staining and Sudan III staining) and ultrastructurally. Results: Although there were no obvious differences in Toluidine blue-stained sections of the iliac crest cartilage between LCPD and control patients, the Sudan III-positive chondrocytes in the resting cartilage were more prominent in the LCPD specimens than in the control specimens. These sudanophilic granules were confirmed to be lipid droplets by electron microscopic examinations. Ultrastructural examinations of the resting chondrocytes from 3 LCPD patients demonstrated numerous cytoplasmic inclusion bodies with electron dense materials, which were similar to those seen in some of the mucopolysaccharidoses. Conclusions: Increased lipid droplets and numerous cytoplasmic inclusions filled with fibrillar materials were suggestive of the initial metabolic changes of the chondrocytes, which may have a pivotal role in degenerating matrix and lead to vulnerability of the cartilage tissue. Our results indicated that generalized insufficiency in growth cartilage metabolism may be related to the onset of the disease in some LCPD patients.

Sagittal spinal alignment in patients with Legg-Calve-Perthes disease.

Background: Legg‐Calve‐Perthes disease (LCPD) is an avascular necrosis of the capital femoral epiphysis in children. Several studies found a pathophysiological relationship between LCPD and juvenile Scheuermann’s kyphosis, suggesting an abnormal spinal condition related to osteochondrogenesis. In the present study sagittal spinal alignment of the patients with LCPD was analyzed to examine associated spinal involvement.

Arthrodiatasis for chondrolysis with hinge abduction: a case report.

&NA; A 13‐year‐old boy with bilateral chronic slipped capital femoral epiphysis was referred to the Nagoya University Hospital. Chondrolysis occurred on the left side 3 months after a subcapital wedge osteotomy and a concavity of the femoral head appeared, which formed hinge abduction. Increase of the joint space and resolution of the hinge were achieved by arthrodiatasis. As arthrodiatasis can resolve hinge abduction by distraction and reduce mechanical stress, it may be taken into consideration as an option for diseases with hinge abduction.

A comparative study of blade plate fixation and external fixation in osteotomies for slipped capital femoral epiphysis.

We have performed corrective osteotomies for moderate or severe slipped capital femoral epiphysis (SCFE) using an original blade plate (BP) until 2006 and using a hybrid external fixator (EF) since 2007. We designed a comparative study of the short-term results between BP and EF devices in the treatment of proximal femoral osteotomies in SCFE. Nineteen SCFE patients (12 BP; seven EF) who underwent corrective osteotomies at our institution were included. Clinical and radiographic valuables including the operative time, intraoperative blood loss, postoperative improvement of head shaft angle, and posterior tilting angle, Harris hip score, limb-length discrepancy, and associated complications were compared between the two groups. Although there were no significant differences between the two groups in postoperative improvement of head shaft angle and posterior tilting angle, Harris hip score, and limb-length discrepancy, the EF group showed significantly shorter operative time and less intraoperative blood loss. Serious complications were observed in two patients of the BP group (deep infection and chondrolysis, respectively) and one of the EF group (chondrolysis). Percutaneous proximal femoral osteotomy using an EF appears to be safe, easy, and effective in correcting multiplanar deformities associated with SCFE. It has potential advantages over commonly used open techniques in terms of simplicity and less invasiveness.

Corrective Osteotomy with an Original Plate for Moderate Slipped Capital Femoral Epiphysis

We investigated, at skeletal maturity, the radiographic and clinical results of 20 patients with slipped capital femoral epiphysis (SCFE) who were treated by corrective osteotomy (CO). Mean age was 13.1 years at the time of operation and 19.8 years at the final examination. CO was performed by the intertrochanteric open-wedge method using an original plate without physeal fixation. The mean posterior tilt angle (PTA) was 47° before CO, 12° after CO, and 9° at the final examination, which indicated that 35° correction was obtained by CO and that this was maintained to skeletal maturity. Physeal closure was recognized in all cases without further slippage. Fifteen of the 20 patients had remodeling of the proximal femur according to the criteria of Jones et al. Six patients had very mild osteoarthritis (OA) changes according to the criteria of Boyer et al. at the final examination. Clinical results were also good with a low incidence of complications. We think that CO using the original plate is a useful method for moderate SCFE because its radiographic and clinical results are good with a simple technique. We emphasize the needlessness of physeal fixation at CO because natural physeal closure occurs without further slippage.