Papers by Motoko Miyawaki
International Journal of Orthopedics and Rehabilitation, 2016
Objective: The purpose of this study was to determine whether Magnetic resonance imaging (MRI) ca... more Objective: The purpose of this study was to determine whether Magnetic resonance imaging (MRI) can distinguish between a partial anterior cruciate ligament (ACL) tear and a normal ACL. Materials and Methods: MR images of 20 patients with an arthroscopically confirmed partial ACL tear were retrospectively interpreted by the author, comparing with normal ACLs. Results and Discussion: All knees with a partial ACL tear had a continuous band of low signal, of which 15 had no increased signal intensity on proton density-weighted images. MRI could not distinguish between a partial ACL tear and a normal ACL. Orthopedic surgeons had better consider an ACL tear when a patient has traumatic hemarthrosis or anxiety provoked by the sensation of the knee ‘going out’ or ‘giving way’ during the pivot shift test, even if the ACL has a continuous band of low signal on the oblique sagittal view on MRI.
results of isolated reconstruction of the medial patellofemoral ligament for recurrent dislocatio... more results of isolated reconstruction of the medial patellofemoral ligament for recurrent dislocation and subluxation of the patella
Knee Surgery, Sports Traumatology, Arthroscopy, 2014
Graft healing following anterior cruciate ligament (ACL) reconstruction is a complex process char... more Graft healing following anterior cruciate ligament (ACL) reconstruction is a complex process characterized by phases of healing that lead to ACL remodelling. Our hypothesis is that fibrin clot addition to ACL reconstruction will result in advanced graft remodelling and healing when compared to a control group at 12 weeks as observed by histology, immunohistochemistry and magnetic resonance imaging (MRI). Eleven Spanish Boar goats underwent double-bundle ACL reconstruction: 8 were analysed and 3 were excluded. Group 1 was treated with DB ACL reconstruction utilizing autologous fibrin clots (n = 4), and group 2 was treated with standard DB ACL-R (n = 4). Histological and radiographic analysis was performed at 12 weeks. Each animal underwent 3-T MRI immediately after euthanization for evaluation of graft signal intensity utilizing the signal noise quotient (SNQ). Specimens were then sectioned and stored for standard histological and immunohistochemistry testing. The mean ligament tissue maturity index score was significantly higher for group 1 (15 ± 2.3) compared with group 2 (7.7 ± 5.2) (p < 0.05). The mean vascularity (cell/mm(2)) for group 1 was 7.1 ± 1.3 and 9.3 ± 3.1 for group 2 (n.s.). The mean collagen type 1 (% 50× field) for group 1 was 35.8 ± 22.1 and 19.9 ± 20.5 for group 2 (n.s.). The mean SNQ for the AM bundle was 1.1 ± 0.7 for group 1 and 3.1 ± 1.8 for group 2 (n.s.). The mean SNQ for the total PL bundle was significantly lower for group 1 (1.1 ± 0.7) compared with group 2 (3.7 ± 1.3) (p < 0.05). There was a significant correlation between the vascularity and the ligament tissue maturity index score as well as between collagen type 1 and SNQ, both AM and PL bundles (p < 0.05). The use of fibrin clot in ACL reconstruction in a caprine model demonstrated improved healing with respect to histological analysis of the intra-articular ACL reconstruction segment and decreased signal intensity on MRI. It may lead to improved graft healing and maturation. By accelerating the intra-articular healing and ligamentization, the outcome of patients after ACL-R can be improved with faster return to sports and daily activity.
Modern Rheumatology, 2008
We present the case of a 63-year-old woman with a six-year history of rheumatoid arthritis (RA) a... more We present the case of a 63-year-old woman with a six-year history of rheumatoid arthritis (RA) and a left iliopsoas bursitis. Radiography had detected destructive changes in her hip joint associated with her bursitis, and she had reported some paresthesia along the left anterior distal thigh. Her pain and numbness remained tolerable, and her disease activity was well controlled until she accidentally fell on the floor, which resulted in an unstable intertrochanteric fracture of left femur with displacement of the proximal portion. The fracture was successfully treated with open reduction and internal fixation, but after the surgery, her femoral nerve palsy worsened. She subsequently underwent bursa excision after the failure of conservative treatment. Accordingly, after bursa excision, the postoperative course was uneventful, and her neurological symptoms gradually disappeared. We would recommend that bursa excision be considered even in cases of iliopsoas bursitis associated with mild femoral neuropathy when destructive changes in the hip joint are also present.
Modern Rheumatology, 2007
We conducted a study to assess the predictive factors for total knee arthroplasty (TKA) in a coho... more We conducted a study to assess the predictive factors for total knee arthroplasty (TKA) in a cohort of rheumatoid arthritis (RA) patients recruited and followed prospectively for 5 years. A linked registry study using information from a large observational cohort of RA patients followed at the Institute of Rheumatology, Tokyo Women's Medical University (IORRA) was done. Baseline routine clinical and laboratory assessments were recorded. The data were analyzed using the multivariate piecewise-linear Cox (PL-Cox) regression model; the model initially included variables such as gender, age, duration of the disease, visual analog scale (VAS) generated by physicians (VAS-physician), patient-reported VAS for pain (VAS-pain), VAS for general health (VAS-GH), disability level using the Japanese version of the Health Assessment Questionnaire (J-HAQ), C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor (RF), and hemoglobin. Of the 3945 patients registered at baseline, 955 (24.2%) had pain or tenderness in their knee joints, and 114 (11.9%) had TKA surgery in one or both knee joints. On PL-Cox regression, the variables with positive coefficients were J-HAQ, VAS-pain, VAS-physician, and RF positive; advanced age was associated with a reduced risk of TKA. The hazard ratios were: 0.920 for age >60 years; 2.64 for J-HAQ <1.5; 1.01 for J-HAQ >1.5; 1.47 for VAS-pain >6 (cm); 1.20 for VAS-physician >4 (cm); and 2.08 for RF positive. The consistently predictive factors for TKA in RA were age, J-HAQ, VAS-pain, VAS-physician, and RF positive. Age greater than 60 years was associated with a decreased risk of TKA, while J-HAQ from 0 to 1.5, VAS-pain >6 (cm), and VAS-physician >4 (cm) were associated with an increased risk for TKA surgery. These results suggest that, when treating RA patients, physicians should pay particular attention to pain complaints, the patient's daily activity level, and the RF factor status.
JCR: Journal of Clinical Rheumatology, 2010
Spontaneous Achilles tendon rupture associated with rheumatoid arthritis (RA) is a very rare comp... more Spontaneous Achilles tendon rupture associated with rheumatoid arthritis (RA) is a very rare complication. In this report, we have experienced neglected spontaneous rupture of the Achilles tendon in 5 elderly RA patients, and report its clinical features and management. These patients had taken corticosteroids for a long time for RA control. Moreover, they did not show any signs, such as click or impact on the rear foot at the moment of the rupture, and had few complaints or obvious symptoms around their ankles or the rear of the foot after the rupture. This suggests that the lack of severe symptoms prevented the early diagnosis of the Achilles tendon rupture, and that this injury had been neglected during treatment for RA. Therefore, careful diagnosis of the Achilles tendon rupture is needed in elderly patients with RA, even if they have little or no history of trauma.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2013
Knee Surgery, Sports Traumatology, Arthroscopy, 2014
Purpose To evaluate magnetic resonance imaging (MRI) graft signal intensity after allograft doubl... more Purpose To evaluate magnetic resonance imaging (MRI) graft signal intensity after allograft double-bundle (DB) anterior cruciate ligament (ACL) reconstruction and determine the relationship between signal intensity and time from surgery. Methods Twenty-six patients with an intact graft on MRI after anatomic allograft DB ACL reconstruction up to 1 year post-operatively were included. All subjects underwent post-operative MRI using a 1.5-T magnet. Sagittal proton density-weighted images (PDWI) and sagittal T2-weighted images (T2WI) were analysed. Using the region-of-interest (ROI) function on imaging software, the anteromedial (AM) and posterolateral (PL) bundles of the graft and the posterior cruciate ligament (PCL) were outlined. Mean signal intensity of the three ROIs were recorded as absolute signal intensity. Signal intensity (SI ratio) was calculated based on the signal intensity of the PCL. Correlation coefficients were calculated to determine the relationship between signal intensity and time from surgery. Results SI ratio of the PL bundle was higher than that of the AM bundle for both the PDWI (1.7 ± 1.5 vs. 2.5 ± 1.7, p \ 0.05) and T2WI (1.3 ± 0.4 vs 1.6 ± 0.6, p \ 0.05). There were weak correlations between AM SI ratio and time from surgery (r = 0.38, p \ 0.05 on PDWI), and moderate correlations between PL SI ratio and time from surgery (r = 0.43, p \ 0.05 on PDWI) (r = 0.44, p \ 0.05 on T2WI). Conclusions The PL bundle displayed increased signal intensity compared to the AM bundle and based on previous studies may indicate a longer healing process. Plain MRI may be useful to assess graft healing after ACL reconstruction. Level of evidence Retrospective case series, Level IV.
Knee Surgery, Sports Traumatology, Arthroscopy, 2013
The native anterior cruciate ligament (ACL) is composed of two distinct bundles, the anteromedial... more The native anterior cruciate ligament (ACL) is composed of two distinct bundles, the anteromedial (AM) and posterolateral (PL), and both have been shown to be reliably measured on magnetic resonance imaging (MRI). The purpose of this study was to measure the size of the AM and PL bundles after ACL double-bundle reconstructions on MRI and compare this to the relative graft size at the time of surgery. Between January 2007 and April 2010, 85 knees were identified after allograft double-bundle ACL reconstruction with post-operative MRI (1.5 T) and met inclusion criteria. On standard sagittal, coronal and oblique coronal MRIs, the AM and PL bundles were delineated and the midsubstance width of the ACL graft was measured. The images were independently measured in a blinded fashion by two observers. Linear and curvilinear regression analysis was used to analyse the relationship between graft size and time after reconstruction. The mean age of the patients was 24.6 years (SD 10.4). Mean time from surgery to post-operative MRI was 271.5 days (SD 183.4). The mean percentage of the original size of the AM bundle was 86.9% (SD 9.9) and of the PL bundle was 88.6% (SD 9.9). There was no correlation between the relative size of the AM graft and the time from surgery (r = 0.3, n.s.) and no significant relationship for the PL graft (r = 0.1, n.s). On average, there was no graft enlargement of the AM and PL grafts 275.1 days after allograft ACL double-bundle reconstruction, as the mean relative graft size was less than 100 % on MRI. This study suggests that surgeons, who use allografts, should measure the ACL and replace it with a similar size, as there is a low risk of hypertrophy of the graft within one year post-operative. IV.
Accurate three-dimensional (3D) models of bone and cartilage are required to estimate joint surfa... more Accurate three-dimensional (3D) models of bone and cartilage are required to estimate joint surface interactions, such as cartilage-to-cartilage contact patterns and to evaluate tissue response to load, intervertebral disc strain or cartilage strain, during in vivo movement. Information obtained from these highly accurate 3D models can be used to evaluate the efficacy of different surgical techniques and to track disease progression, for example cartilage thinning in osteoarthritis.
Acta orthopaedica Belgica, 2006
Complications and results of medial patellofemoral ligament (MPFL) reconstruction, performed betw... more Complications and results of medial patellofemoral ligament (MPFL) reconstruction, performed between 2000 and 2003, were studied retrospectively in 24 randomised patients (24 knees). All procedures were performed for recurrent dislocation or subluxation of the patella, using an autogenous semitendinosus tendon. Two different methods of anchoring of the transplant were compared. After a 2-year follow-up, patellar stability was found to be similar, when the transplant was sutured to the fibrous tissue and periosteum overlying the patella or when it was fixed in a bone tunnel through the patella. The majority of the patients who had undergone MPFL reconstruction have returned to their previous level of sports activities. We had two cases of patella fracture and one case of persisting patella apprehension after surgery. Further studies must determine which measures are necessary to prevent these complications.
Acta orthopaedica Belgica
Complications and results of medial patellofemoral ligament (MPFL) reconstruction, performed betw... more Complications and results of medial patellofemoral ligament (MPFL) reconstruction, performed between 2000 and 2003, were studied retrospectively in 24 randomised patients (24 knees). All procedures were performed for recurrent dislocation or subluxation of the patella, using an autogenous semitendinosus tendon. Two different methods of anchoring of the transplant were compared. After a 2-year follow-up, patellar stability was found to be similar, when the transplant was sutured to the fibrous tissue and periosteum overlying the patella or when it was fixed in a bone tunnel through the patella. The majority of the patients who had undergone MPFL reconstruction have returned to their previous level of sports activities. We had two cases of patella fracture and one case of persisting patella apprehension after surgery. Further studies must determine which measures are necessary to prevent these complications.
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2013
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Papers by Motoko Miyawaki