Takuma Yamasaki

Transplantation of Meniscus Regenerated by Tissue Engineering With a Scaffold Derived From a Rat Meniscus and Mesenchymal Stromal Cells Derived From Rat Bone Marrow

The purpose of this study was to assess transplantation of regenerated menisci using scaffolds from normal allogeneic menisci and bone-marrow-derived mesenchymal stromal cells (BM-MSCs) of rats. We reported that scaffolds derived from normal menisci seeded with BM-MSCs in vitro could form meniscal tissues within 4 weeks. Then, we hypothesized that our tissues could be more beneficial than allogeneic menisci regarding early maturation and chondroprotective effect. Bone marrow was aspirated from enhanced green fluorescent protein transgenic rats. BM-MSCs were isolated and seeded onto scaffolds which were prepared from Sprague-Dawley rat menisci. After 4 weeks in coculture, the tissues were transplanted to the defect of menisci. Repopulation of BM-MSCs and expression of extracellular matrices were observed in the transplanted tissues at 4 weeks after surgery. At 8 weeks, articular cartilage in the cell-free group was more damaged compared to that in the cell-seeded group or the meniscectomy group.

Bone-marrow-derived mononuclear cells with a porous hydroxyapatite scaffold for the treatment of osteonecrosis of the femoral head: A preliminary study

We have investigated the effectiveness of the transplantation of bone-marrow-derived mononuclear cells (BMMNCs) with interconnected porous calcium hydroxyapatite (IP-CHA) on early bone repair for osteonecrosis of the femoral head. We studied 22 patients (30 hips) who had osteonecrosis with a minimum follow-up of one year after implantation of BMMNCs. The mean age at surgery was 41 years (18 to 64) and the mean period of follow-up was 29 months (19 to 48). In a control group, cell-free IP-CHA was implanted into a further eight patients (9 hips) with osteonecrosis of the femoral head and the outcomes were compared. A reduction in the size of the osteonecrotic lesion was observed subsequent to hypertrophy of the bone in the transition zone in the BMMNC group. In three patients in the treatment group progression to extensive collapse was detected. In the control group subtle bone hypertrophy was observed, but severe collapse of the femoral head occurred in six of eight hips. In this limited study the implantation of BMMNCs and IP-CHA appears to confer benefit in the repair of osteonecrosis and in the prevention of collapse.

Angiogenic microRNA-210 is present in cells surrounding osteonecrosis.

A role of microRNAs (miRNAs), which are ∼22‐nucleotide non‐coding RNAs, has recently been recognized in human diseases. The objective of this study was to identify the expression pattern of miRNA (miR)‐210, known to be associated with angiogenesis, in bone from patients with osteonecrosis (ON) of the femoral head. The expression of miR‐210 in bone from 10 patients with osteoarthritis (OA) of the hip and ten with ON was analyzed by quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) and by in situ hybridization. In addition, immunohistochemical staining for von Willebrand factor (vWF) and vascular endothelial growth factor (VEGF) was performed to identify the miR‐210 expressing cells. We found that in ON samples, the expression of mature, primary miR‐210, VEGF, matrix metalloproteinase (MMP)‐2, and MMP‐7 was significantly higher than that of OA samples. Section in situ hybridization of mature miR‐210 revealed that mature miR‐210 is expressed around the necrotic area. vWF and VEGF were also strongly expressed in the miR‐210 expressing cells. This study shows that miR‐210 is intensely expressed in ON, and might play a role in ON pathogenesis. The present study provides a solid basis for further functional analyses of miRNAs in ON.

Crossover sign after rotational acetabular osteotomy for dysplasia of the hip

BackgroundThis study was performed to evaluate whether the radiographic crossover sign influences the painful femoroacetabular impingement or the radiographic progression of osteoarthritis after rotational acetabular osteotomy (RAO).MethodsA total of 104 patients (115 hips) with preosteoarthritis (pre-OA) or early-stage OA of the hip due to dysplasia underwent RAO. Their mean age at the time of surgery was 34.7 years. The mean follow-up period was 13 years. Clinical follow-up was performed with the system of Merle d’Aubigne, and the impingement sign was evaluated. Radiographic analyses included the center-edge angle, acetabular roof angle, head lateralization index (HLI), joint congruency, crossover sign, posterior wall sign, acetabular index of depth to width, pistol grip deformity, and femoral head/femoral neck ratio.ResultsThe mean clinical score improved significantly from 14.6 preoperatively to 17.0 at follow-up. The impingement sign at follow-up was observed in 14 hips (12.2%). The center-edge angle, acetabular roof angle, and head lateralization index (HLI) improved significantly after surgery. The crossover sign was observed in 8 hips (7.0%) preoperatively and in 49 hips (42.6%) postoperatively. The posterior wall sign was observed in 70 hips (60.9%) preoperatively and in 73 hips (63.5%) postoperatively. The impingement sign after RAO was positive significantly in the postoperative crossover sign-positive hips. Radiographic progression of OA was observed in 11 hips (crossover sign was positive in 7 hips and negative in 4 hips). The only factors significantly associated with radiographic progression after RAO were fair postoperative joint congruency and age at surgery.ConclusionsAlthough there was no significant radiographic progression of OA despite significant retroversion, anterior impingement and radiographic crossover sign after RAO are should be checked during the procedure. The goal of RAO should be correct alignment of the acetabulum including a correct version with a negative crossover sign.

Are cam and pincer deformities as common as dysplasia in Japanese patients with hip pain

In Japan, osteoarthritis (OA) of the hip secondary to acetabular dysplasia is very common, and there are few data concerning the pathogeneses and incidence of femoroacetabular impingement (FAI). We have attempted to clarify the radiological prevalence of painful FAI in a cohort of Japanese patients and to investigate the radiological findings. We identified 176 symptomatic patients (202 hips) with Tönnis grade 0 or 1 osteoarthritis, whom we prospectively studied between August 2011 and July 2012. There were 61 men (65 hips) and 115 women (137 hips) with a mean age of 51.8 years (11 to 83). Radiological analyses included the α-angle, centre-edge angle, cross-over sign, pistol grip deformity and femoral head neck ratio. Of the 202 hips, 79 (39.1%) had acetabular dysplasia, while 80 hips (39.6%) had no known aetiology. We found evidence of FAI in 60 hips (29.7%). Radiological FAI findings associated with cam deformity were the most common. There was a significant relationship between the pistol grip deformity and both the α-angle (p < 0.001) and femoral head-neck ratio (p = 0.024). Radiological evidence of symptomatic FAI was not uncommon in these Japanese patients.

Mid-term results of acetabular reconstruction using a Kerboull-type acetabular reinforcement device

PurposeThe purpose of this study was to investigate the mid-term results of 32 acetabular reconstructions performed using a Kerboull-type acetabular reinforcement device and bone graft between June 1997 and January 2009.MethodsThe mean age of the patients at the time of surgery was 71.4 years (range 55–85). Patients were followed-up for a mean of 7.5 years (range 2.1–13.7). The acetabular bone defects according to the American Academy of Orthopaedic Surgeons system was type III for 29 hips and type IV for three hips. Bulk allografts were performed in 30 hips and morselised autografts (iliac bone) were performed in two hips. Clinical evaluations were made according to the criteria of Postel/Merle d’Aubigné.ResultsThe mean pre-operative Postel/Merle d’Aubigné hip score was 7.0±2.9, and the final follow-up hip score was 12.6±2.8. Six hips showed radiographic loosening, and two hips required further revision. A Kaplan-Meier analysis showed that the five-year and ten-year survival rates were 96.9% and 92.3%, respectively, using further revision of the acetabular device as an end point.ConclusionAcetabular reconstruction using a Kerboull-type acetabular reinforcement device and bone graft gives satisfactory mid-term results.

Rotational Acetabular Osteotomy for Pre- and Early Osteoarthritis Secondary to Dysplasia Provides Durable Results at 20 Years

BackgroundHip dysplasia is a common cause of secondary osteoarthritis (OA). Periacetabular osteotomy or rotational acetabular osteotomy has been used as joint-preserving procedures. However, only a few reports of long-term results with these operations have been reported.Questions/purposes(1) Would satisfactory clinical and radiographic outcomes be maintained at a mean duration of 20 years after rotational acetabular osteotomy for pre- and early-stage OA; and (2) could we identify risk factors for radiographic progression of OA?MethodsBetween 1987 and 2001, we treated 159 patients (173 hips) with rotational acetabular osteotomies for the diagnosis of pre-OA or early-stage OA according to the technique of Ninomiya and Tagawa. During that period, our general indications for this approach were age younger than 60 years, center-edge angle less than 20°, and improved femoral head coverage and joint congruency on preoperative AP plain radiographs of the hip in abduction; we did not use this approach when joint congruency was not improved or no widening of the joint space was noted on preoperative AP plain radiographs of the hip in abduction. Of those patients, 21 patients with pre-OA (followup rate: 84% [27 hips]) and 110 patients in the early-stage group (followup rate: 82% [118 hips]) were available at a minimum of 15 years for a total patient group of 131 (followup rate: 82% [145 hips]). The mean age at the time of surgery was 22 years in the pre-OA group and 38 years in the early-stage group. The mean followup was 21 years in the pre-OA group and 20 years in the early-stage group. Clinical evaluation was performed with the Merle d’Aubigne and Postel rating scale, and radiographic analyses included measurements of the center-edge angle, acetabular roof angle, and head lateralization index on preoperative and postoperative AP radiographs of the pelvis. Postoperative joint congruency was also evaluated. The cumulative probabilities of radiographic signs of OA progression were estimated with use of the Kaplan-Meier product-limited method and parametric survivorship analysis using the Cox proportional-hazards model was used to determine risk factors for radiographic OA progression.ResultsThe mean clinical score improved very slightly, from 15 (SD, 0.8) to 18 (SD, 1.1) (95% confidence interval [CI], −2.9 to −2.0; p < 0.001) in the pre-OA group and from 15 (SD, 1.0) to 16 (SD, 2.1) (95% CI, −2.0 to −1.2; p < 0.001) in the early-stage group at followup. Fourteen patients (15 hips) including one pre-OA patient (one hip) and 13 early-stage patients (14 hips) experienced worsening of their Merle d’Aubigne and Postel score, from a mean of 15 (SD, 0.9) to 12 (SD, 1.6) (95% CI, 1.8–3.3; p < 0.001). Eight patients (nine hips) with early-stage OA preoperatively underwent total hip arthroplasty at a mean duration after rotational acetabular osteotomy of 20 (SD, 2.5) years. Radiographic indices were improved after surgery in both groups. Radiographic progression of OA occurred in 24 patients (25 hips). Kaplan-Meier survivorship analysis, with radiographic signs of progression of OA as the endpoint, predicted survival of 96% (95% CI, 89%–100%) at 10 years and 20 years in the pre-OA group. For the early-stage group, we found survivorship of 89% (95% CI, 83%–95%) at 10 years and 78% (95% CI, 69%–87%) at 20 years. We identified two factors associated with poor outcome: fair (rather than excellent and good) postoperative joint congruency (hazard ratio, 12.1; 95% CI, 3.8–39; p < 0.001) and age older than 46 years at the time of surgery (hazard ratio, 4.6; 95% CI, 1.9–11; p < 0.01).ConclusionsRotational acetabular osteotomy is an effective surgical procedure for symptomatic dysplastic hips in pre- and early-stage OA, and it prevented radiographic OA progression and maintained hip function at a mean 20 years after surgery.Level of EvidenceLevel IV, therapeutic study.

Inclusion and Exclusion Criteria in the Diagnosis of Femoroacetabular Impingement

PURPOSE The purpose of this study was to clarify the criteria for femoroacetabular impingement (FAI) by way of a systematic review of FAI-related articles, as well as to define more appropriate inclusion or exclusion criteria in the diagnosis of FAI. METHODS A systematic review of FAI-related articles was performed using Web of Science. Thirty-two articles met the inclusion and exclusion criteria. In these articles we investigated radiographic findings for the diagnosis of FAI and the prevalence of each FAI-related finding. RESULTS The crossover sign was used in 22 articles (69%); acetabular index, 9 articles (28%); posterior wall sign, 7 articles (22%); and prominence of the ischial spine sign, 3 articles (7%). Regarding acetabular coverage, the lateral center-edge (LCE) angle was described in 13 articles (41%), in which an LCE angle either of more than 40° or of more than 30° combined with an acetabular index of less than 0° was considered an inclusion criterion for pincer impingement. Meanwhile, the alpha angle was used in 28 articles (88%), in which 50° or 55° was recommended as a positive finding of cam impingement. CONCLUSIONS Common findings of pincer or cam deformity were used to select FAI patients with sufficient coverage of the acetabulum with an LCE angle of more than 25°. Patients with an LCE angle of less than 25° or those with local acetabular deficiency regardless of having a normal LCE angle should be excluded from the FAI criteria, even if the FAI-related findings are positive. LEVEL OF EVIDENCE Level IV, systematic review of Level I through IV studies.

The influence of stem offset and neck shaft angles on the range of motion in total hip arthroplasty

PurposeTo evaluate the influence of stem offset and neck shaft angles on the range of motion before component impingement (ROMCI) and bony impingement (ROMBI), and the types of impingement in total hip arthroplasty (THA).MethodsUsing the computed tomography data of 101 patients who underwent THA, three-dimensional dynamic motion analysis was performed using a modular implant (Kinectiv® stem) that enabled adjustment of offset and leg length independently. We defined offset as horizontal offset (HO) and leg length as vertical offset (VO), and measured the ROMCI and ROMBI in flexion (Flex), internal rotation (Int-R) and external rotation (Ext-R) with the configuration of each horizontal/vertical offset.ResultsWe found that HO lengthening increased the ROMCI and ROMBI in Flex and Int-R by delaying bony impingement, although excessive lengthening had minimal effect. On the contrary, VO lengthening decreased the ROMCI and ROMBI in Flex and ROMCI in Int-R. As for Ext-R, VO lengthening had positive effects on the ROMCI and ROMBI, whereas lengthening of HO had negative effects on the ROMCI and ROMBI.ConclusionsWe demonstrated that the appropriate long offset with a low shaft angle increased the ROM in Flex and Int-R, and a high neck shaft angle increased the ROM in Ext-R. We should use implants properly in accordance with the types of impingement for avoiding dislocations in THA.

Prevention of osteonecrosis by intravenous administration of human peripheral blood-derived CD34-positive cells in a rat osteonecrosis model.

Aseptic idiopathic osteonecrosis of the femoral head is a painful disorder of the hip that can lead to collapse of the femoral head and the need for total hip replacement following joint destruction. Treatment of this disease still remains a clinical challenge. Adult human circulating CD34+ cells have been demonstrated to contribute to vasculogenesis and osteogenesis in immunodeficient rat non‐union models in vivo. We hypothesized and proved that the transplantation of CD34+ cells could have a role for improvement of osteonecrosis by promoting vasculogenesis and osteogenesis. Vascular deprivation‐induced femoral head necrosis was developed in immunodeficient rats and we then administered human G‐CSF mobilized CD34+ cells intravenously. At 4 weeks after administration, the structure of the femoral head and neck were evaluated histologically and morphometrically with haematoxylin and eosin (H&E) staining and micro‐CT imaging. Microangiography was carried out for macroscopic evaluation of neovascularization, and the contribution of human cells to vasculogenesis and osteogenesis was evaluated by immunofluorescent staining with human‐specific antibodies. Our treatment resulted in an obvious improvement of osteonecrosis after CD34+ cell administration and demonstrated the differentiation potential of CD34+ cells into endothelial cells and osteoblasts. In conclusion, this new therapeutic approach using circulating cell fraction could be a promising cell‐based therapy for early‐stage osteonecrosis of the hip. Copyright