A Mouse Distraction Osteogenesis Model

Distraction osteogenesis (DO) is a surgical procedure that involves skeletal tissue regeneration without cell transplantation. A DO model consists of the ...

Nagoya University Graduate School of Medicine

Periacetabular osteotomy (PAO) is an effective treatment for preosteoarthritis and early osteoarthritis in young and active patients with hip dysplasia. However, conversion to total hip arthroplasty (THA) for failed PAO is difficult owing to morphologic changes. The objective of the present study was to investigate outcomes of patients who underwent THA for failed PAO.

Significantly Poor Outcomes of Total Hip Arthroplasty After Failed Periacetabular Osteotomy.

The purpose of this study was to examine the 10-year survivorship and clinical outcome after curved intertrochanteric varus osteotomy (CVO) for the osteonecrosis of the femoral head (ONFH), and to determine what factors predict the failure of this procedure.

What factors predict the failure of curved intertrochanteric varus osteotomy for the osteonecrosis of the femoral head?

We performed periacetabular osteotomy (PAO) combined with intertrochanteric valgus osteotomy (TVO) to obtain better congruity for patients with acetabular dysplasia and nonspherical femoral head. These patients with PAO-combined TVO demonstrate long-term progression of osteoarthritis, thereby, needing conversion to total hip arthroplasty (THA) and is difficult due to morphological changes. The objective of the present study was to investigate outcomes of patients who underwent THA after PAO-combined TVO.

Total Hip Arthroplasty After Periacetabular and Intertrochanteric Valgus Osteotomy.

The objective of the present study was to investigate clinical, quality of life, and radiographic outcomes of patients who underwent total hip arthroplasty (THA) after transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH).

Total Hip Arthroplasty After Transtrochanteric Rotational Osteotomy for Osteonecrosis of the Femoral Head: A Mean 10-Year Follow-Up.

Achondroplasia (ACH) is one of the most common short-limbed skeletal dysplasias caused by gain-of-function mutations in the fibroblast growth factor receptors 3 (FGFR3) gene. Distraction osteogenesis (DO) is a treatment option for short stature in ACH in some countries. Although the patients with ACH usually show faster healing in DO, details of the newly formed bone have not been examined. We have developed a mouse model of DO and analyzed new bone regenerates of the transgenic mice with ACH (Fgfr3 mice) histologically and morphologically. We established two kinds of DO protocols, the short-DO consisted of 5days of latency period followed by 5days of distraction with a rate of 0.4mm per 24h, and the long-DO consisted of the same latency period followed by 7days of distraction with a rate of 0.3mm per 12h. The callus formation was evaluated radiologically by bone fill score and quantified by micro-CT scan in both protocols. The histomorphometric analysis was performed in the short-DO protocol by various stainings, including Villanueva Goldner, Safranin-O/Fast green, tartrate-resistant acid phosphatase, and type X collagen. Bone fill scores were significantly higher in Fgfr3 mice than in wild-type mice in both protocols. The individual bone parameters, including bone volume and bone volume/tissue volume, were also significantly higher in Fgfr3 mice than in wild-type mice in both protocols. The numbers of osteoblasts, as well as osteoclasts, around the trabecular bone were increased in Fgfr3 mice. Cartilaginous tissues of the distraction region rapidly disappeared in Fgfr3 mice compared to wild-type mice during the consolidation phase. Similarly, type X collagen-positive cells were markedly decreased in Fgfr3 mice during the same period. Fgfr3 mice exhibited accelerated bone regeneration after DO. Accelerated endochondral ossification could contribute to faster healing in Fgfr3 mice.

Activated FGFR3 promotes bone formation via accelerating endochondral ossification in mouse model of distraction osteogenesis.

There has been constant discussion about whether the clinical outcome of THA after periacetabular osteotomy (PAO) is equivalent to that after primary total hip arthroplasty (THA). However, there have been few reports about patient-reported outcomes (PRO) for those who undergo THA after PAO. We compared the pre- and postoperative PRO of patients who underwent THA after PAO and those who underwent primary THA alone.

Patient-reported outcomes in patients who undergo total hip arthroplasty after periacetabular osteotomy.

Few studies have reported risk factors for stress shielding. We sought to evaluate clinical and radiographic outcomes of a proximally hydroxyapatite-coated straight tapered titanium femoral component stem during a minimum 5-year follow-up and identify factors associated with high-degree stress shielding.

Preoperative Canal Bone Ratio is Related to High-Degree Stress Shielding: A Minimum 5-Year Follow-Up Study of a Proximally Hydroxyapatite-Coated Straight Tapered Titanium Femoral Component.

The objectives of this study were to investigate patient-reported outcomes and referral pain at the first visit in patients with osteonecrosis of the femoral head (ONFH) and to clarify the influence of collapse of the femoral head and the contralateral condition.

Do femoral head collapse and the contralateral condition affect patient-reported quality of life and referral pain in patients with osteonecrosis of the femoral head?

The aim of this study was to compare the clinical outcomes of cementless total hip arthroplasty (THA) used for the treatment of osteonecrosis of the femoral head (ONFH) and for osteoarthritis (OA) at a mean ten years follow-up.

Yusuke Osawa

Department of Orthopaedic Surgery

Nagoya University Graduate School of Medicine

A Mouse Distraction Osteogenesis Model