Atsushi Narita

Effect of Platelet-Rich Plasma With Fibrin Matrix on Healing of Intrasynovial Flexor Tendons

PURPOSE To investigate the effects of platelet-rich plasma (PRP) with fibrin matrix on the healing of intrasynovial flexor tendons in a rabbit model in vivo. METHODS We transected and repaired 156 toe flexors of 73 rabbits using the technique of Tsuge et al and a simple running epitendinous suture. We randomly assigned Repaired tendons to groups that recieved no additional treatment (control) or to which we applied PRP, fibrin (F), or PRP with fibrin matrix (PRP-F) at the repair site. We scored edema and adhesion at 2, 3, and 6 weeks after surgery, and linearly tested repaired tendons for load to failure. We also histologically evaluated tendons at 2 and 3 weeks. RESULTS Edema scores and adhesion scores did not significantly differ among the 4 groups at any time point. Mean load to failure in the PRP-F group (14.7 N) was the highest among the 4 groups at 2 weeks after surgery, and was significantly higher than in the control group (10.0 N). Median histological scores in the PRP-F group (3.3 points) were significantly higher than in the control group (1.0 point). Mean load to failure in the PRP-F group (16.1 N) was highest, and median histological scores in the PRP-F group (3.5 points) were higher than in the control group (2.4 points) at 3 weeks, although there were no significant differences at 3 or 6 weeks. CONCLUSIONS In a rabbit model of cut flexor tendons, PRP with fibrin matrix significantly increased healing strength within 2 weeks after surgery. Side effects such as increases in toe edema or adhesions around the tendons did not arise. CLINICAL RELEVANCE Platelet-rich plasma with fibrin matrix might help reduce the risk of repeated rupture after flexor tendon surgery, and lead to early rehabilitation.

Effect of gelatin hydrogel incorporating fibroblast growth factor 2 on human meniscal cells in an organ culture model

Efforts to use growth factors to enhance the healing potential of the meniscus have been impeded because their half-lives are too short to maintain the biological activity. The thread was coated with gelatin hydrogel and fibroblast growth factor 2 (FGF 2) was biologically stabilized by incorporating in a gelatin hydrogel-coated thread. The purpose of this study is to investigate the effect of gelatin hydrogel-coated thread incorporating FGF 2 on human meniscal cells in an organ culture. Twenty-five menisci were cut into small pieces, and selected pieces were sutured with gelatin hydrogel-coated thread incorporating FGF 2 (FGF(+) group) or physiologic saline (FGF(-) group), followed by organ culture. The meniscal samples histologically evaluated 4, 7, and 14 days later. The cell density and the number of PCNA-positive cells for the FGF(+) group were higher than those of the FGF(-) group, while the number of TUNEL-positive cells was lower. These results suggest that FGF 2 stimulates the proliferation of meniscal cells and inhibits meniscal cell death. Gelatin hydrogel-coated threads releasable FGF 2 may be useful to promote repairing of human meniscus.

Biodegradable Gelatin Hydrogels Incorporating Fibroblast Growth Factor 2 Promote Healing of Horizontal Tears in Rabbit Meniscus

PURPOSE The purpose of this study was to investigate the in vivo effects of gelatin hydrogels (GHs) incorporating fibroblast growth factor 2 (FGF-2) on meniscus repair in a rabbit model. METHODS FGF-2 was biologically stabilized by incorporation into GHs. This system enables FGF-2 to be released with its biologic activity intact. A total of 64 skeletally mature female Japanese white rabbits were used. A horizontal tear was made in the medial meniscus, and these tears were divided into 4 groups: GH-FGF, GH-no FGF, FGF (FGF-2 alone), and no treatment. The meniscus was evaluated histologically at 2, 4, 8, and 12 weeks after surgery. Cell density and the percentages of proliferating cell nuclear antigen-positive cells and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells were measured, and a scoring system ranging from 5 points (complete healing) to 0 points (no evidence of healing) was used. RESULTS Cell density was significantly higher in the GH-FGF group than in the other 3 groups at 2, 4, 8, and 12 weeks (P < .01). The percentage of proliferating cell nuclear antigen-positive cells was significantly higher whereas the percentage of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells was significantly lower in the GH-FGF group at 2 and 4 weeks after surgery (P < .05). At 4, 8, and 12 weeks after surgery, healing scores were significantly higher in the GH-FGF group (2.5 points, 2.7 points, and 3.0 points, respectively) than in the GH-no FGF group (1.3 points, 1.4 points, and 2.0 points, respectively) (P < .05). CONCLUSIONS GHs incorporating FGF-2 significantly stimulated proliferation and inhibited the death of meniscal cells until 4 weeks, thereby increasing meniscal cell density and enhancing meniscal repair in a rabbit model. CLINICAL RELEVANCE GHs incorporating FGF-2 are able to enhance the healing of meniscal injury.

THU0118 Trend of Atypical Femoral Fractures in Rheumatic Patients in The Highly Super Aging Area of North Japan

Background A number of recent case reports and series have identified atypical fractures of the femoral shaft. Atypical femoral fractures (AFFs) with lack of trauma or less-energy have been reported to relate using of the bisphosphonates (BPs) and glucocorticoids (GCs) for a long time, affecting collagen diseases1,2. Objectives We have analyzed the AFFs in rheumatic patients in the highly super aging area of North Japan, in which the rate more than 65 year-old people in the population was 28%. Methods We investigated retrospectively all cases of AFF summarized by the American Society for Bone and Mineral Research (ASBMR) Task Force 20131 including affected rheumatic disease patients in all hospitals of our prefectural area from 2009 to 2014. Two independent orthpaedic surgeons have diagnosed blindly AFF and estimated proximal femoral geometry by using radiographic analyses. Observation end of this study was settled on Feb 2016. Results We have 86 cases 99 AFFs in our prefectural area from 2009 to 2014 (1.43 cases/100,000 person/year). The rheumatic patients with AFFs were eleven femurs in eight women in that periods and increased year by year (Fig. 1). Three cases have bilateral AFFs (six femurs, 55%). The mean age of them was 54.9 year-old (33–80). As comorbid conditions, five patients have systematic lupus erythematosus, two dermatomyositis and rheumatoid arthritis, one polyarteritis nodosa and systemic sclerosis. Fracture types were seven subtrochanteric and four diaphyseal femoral fractures. Mean femoral neck angle was 133 degrees (120–141) and femoral shaft angle was 6.1 degree (3–10). Six patients with AFF had prodromal pain (55%). All patients received BPs and all but one prednisolone (PSL). Mean duration of receiving those drugs was 52 months (24–120) and 109 months (36–120), respectively. Mean dosage of PSL was 14 mg/day (0–30). In addition, bilateral AFF group has more PSL dose and duration of PSL, more varus deformity of their femur compared to unilateral AFF group (p<0.05). After affecting the fractures, BPs were quitted in seven femurs except four. The surgery using intramedullary nail fixation were performed in all cases excluding one femur using a locking plate. Teriparatide and therapy of low-intensity pulsed ultrasound was induced for five cases after healing their operated wounds. Mean duration of post-operative observation was 28 months (12–70). At the latest follow-up, ten femurs were observed the sign of union at fracture site on X-ray or computed tomography of their femurs, but not one femur. Mean duration of union of the fracture site was 12.6 months (6–24) in ten femurs. Conclusions Eleven AFFs were observed in 2009–14 in rheumatic patients and the numbers were increased year by year in the highly super aging area of North Japan. The careful management and treatment for the AFFs in rheumatic patients are required even after the surgery, because our all cases have been observed the delayed union or non-union of fracture site at their latest follow-up3. In addition, AFF patients who show varus deformity of their femurs and receive much dose of PSL have highly risk of contralateral AFF. References Shane E, et al. JMBR, 2014, Blacks DM, et al. NEJM, 2010, Thompson RN, et al. JBJS, 2012. Acknowledgement We really appreciate all members of Yamagata Prefectural Committee of Atypical Femoral Fractures Study group. Disclosure of Interest None declared

AB0408 Are Atypical Femoral Fractures in Rheumatic Patients Increasing

Background Atypical femoral fractures with low-energy or lack of trauma have been reported to relate using of the bisphosphonates (BPs) and glucocorticoids for a long time, affecting collagen diseases1,2. Objectives The aim of this study was to analyze the atypical femoral fractures in rheumatic patients in our four institutes retrospectively. Methods We investigated the cases of atypical femoral fractures summarized by the American Society for Bone and Mineral Research (ASBMR) Task Force 20101 among our out-rheumatic patients from 2009 to 2014. Results We have 1,091 out-rheumatic patients/year in our four institutes from 2009 to 2014. The patients with atypical femoral fractures were 8 limbs in six women (0.12%) in six years. Three limbs were injured at 2013, and five at 2014, including two cases has both side atypical femoral fractures (Fig. 1). The mean age of them was 51 year-old (38-73). As comorbid conditions, two patients has dermatomyositis, systematic lupus erythematosus, one rheumatoid arthritis and one polyarteritis nodosa. Fracture types were seven subtrochanteric fractures and one diaphyseal femoral fracture. All patients received BPs and prednisolone (PSL). Mean duration of receiving the drugs was 75 months (36-120) and 114 months (60-180), respectively. Mean dosage of PSL was 15 mg/day (5-30). After affecting the fractures, BPs were quitted and the surgery using intramedullary nail fixation were performed in all cases. One case had the surgical-site infection. Teriparatide was induced excepted one case and therapy of low-intensity pulsed ultrasound was started for all cases after healing their operated wounds. Mean duration of post-operative observation was 12 months (5-23). At the latest follow-up, five femurs were observed the sign of union at fracture site on X-ray or computed tomography of their femurs, but not other three femurs. Mean duration of union of the fracture site was 10 months (6-13) in five femurs. Conclusions Eight atypical femoral fractures were observed in 2013-14, but not in 2009-2012. Atypical femoral fracture may increase year by year. The careful management and treatment for the atypical femoral fractures in rheumatic patients were required even after the surgery, because our all cases have been observed the delayed union or non-union of fracture site at their latest follow-up3. References Shane E, et al. JMBR, 2010. Blacks DM, et al. NEJM, 2010. Thompson RN, et al. JBJS 2012. Disclosure of Interest None declared