Biomedical subjects

Nobuhiro Tsumura

Publications and source records attributed to Nobuhiro Tsumura.

7 recordsLinked to original sources

PubMed2006

Joint gap kinematics in posterior-stabilized total knee arthroplasty measured by a new tensor with the navigation system.

BACKGROUND: The management of soft tissue balance during surgery is essential for the success of total knee arthroplasty (TKA) but remains difficult, leaving it much to the surgeon's feel. Previous assessments for soft tissue balance have been performed under unphysiological joint conditions, with patellar eversion and without the prosthesis only at extension and 90 deg of flexion. We therefore developed a new tensor for TKA procedures, enabling soft tissue balance assessment throughout the range of motion while reproducing postoperative joint alignment with the patellofemoral (PF) joint reduced and the tibiofemoral joint aligned. Our purpose in the present study was to clarify joint gap kinematics using the tensor with the CT-free computer assisted navigation system. METHOD OF APPROACH: Joint gap kinematics, defined as joint gap change during knee motion, was evaluated during 30 consecutive, primary posterior-stabilized (PS) TKA with the navigation system in 30 osteoarthritic patients. Measurements were performed using a newly developed tensor, which enabled the measurement of the joint gap throughout the range of motion, including the joint conditions relevant after TKA with PF joint reduced and trial femoral component in place. Joint gap was assessed by the tensor at full extension, 5 deg, 10 deg, 15 deg, 30 deg, 45 deg, 60 deg, 90 deg, and 135 deg of flexion with the patella both everted and reduced. The navigation system was used to obtain the accuracy of implantations and to measure an accurate flexion angle of the knee during the intraoperative joint gap measurement. RESULTS: Results showed that the joint gap varied depending on the knee flexion angle. Joint gap showed an accelerated decrease during full knee extension. With the PF joint everted, the joint gap increased throughout knee flexion. In contrast, the joint gap with the PF joint reduced increased with knee flexion but decreased after 60 deg of flexion. CONCLUSIONS: We clarified the characteristics of joint gap kinematics in PS TKA under physiological and reproducible joint conditions. Our findings can provide useful information for prosthetic design and selection and allow evaluation of surgical technique throughout the range of knee motion that may lead to consistent clinical outcomes after TKA.

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PubMed2006

Clinical values in computer-assisted total knee arthroplasty.

Thirty posterior stabilized total knee prostheses implanted using a computed tomography-free navigation system were compared to a control group of 30 matched total knee prostheses of the same type implanted via a classical, surgeon-controlled technique. The accuracy of the implantations in relation to the mechanical axis in the navigation group was superior to that of the manual group. Early two-year clinical results including range of motion and Knee Society Clinical Rating Score were equally good compared to the manual group. However, potential long-term outcome and functional improvement require further investigation.

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PubMed2005

Bilateral painful snapping elbows triggered by daily dumbbell exercises: a case report.

We treated a 64-year-old female with bilateral painful snapping elbows due to synovial folds. Resection of the bilateral synovial folds resulted in relief from pain and snapping, and resulted in patient satisfaction. Daily dumbbell exercises of the bilateral elbows starting at an elderly age may have led to the bilateral snapping. Painful snapping elbow is a relatively rare condition, which usually occurs in a unilateral elbow of a younger patient. To our knowledge, bilateral painful snapping elbows triggered by daily dumbbell exercises in older patients have not been previously reported.

Arthralgia↗

PubMed2005

Influence of hip position on knee flexion angle in patients undergoing total knee arthroplasty.

The influence of hip position on knee flexion angle before total knee arthroplasty (TKA) and that after TKA were investigated and compared. Sixty-six patients (70 knees) with osteoarthritis who were undergoing TKA were examined using lateral radiographs of maximum knee flexion angle with the hip joint at 0 degrees extension and 90 degrees flexion. The postoperative rate of decrease in knee flexion angle caused by hip extension was significantly larger compared with the value before surgery. The preoperative rate of decrease in knee flexion angle caused by hip extension showed strong inverse correlation with the preoperative and postoperative knee flexion angle ratio. In conclusion, tightness of the extensor mechanism is present in all knees undergoing TKA and especially has a strong influence on the postoperative flexion angle of the knee.

Arthroplasty, Replacement, Knee↗

PubMed2004

Prosthetic alignment and sizing in computer-assisted total knee arthroplasty.

We implanted 60 posterior stabilized total knee prostheses (P.F.C. Sigma, DePuy, Warsaw, USA). In 30 cases, we used a CT-free navigation system (Vector Vision, Brain LAB, Heimstetten, Germany), and in 30 matched-paired controls, we used a conventional manual implantation. We compared postoperative long-leg radiographs in the two groups. The results revealed a significant difference in favor of navigation. In addition, we compared the preoperative anteroposterior dimension of the femoral condyle with the postoperative value. While there were no significant differences in the preoperative anteroposterior dimension of the femoral condyle between the two groups, the postoperative value in the navigation group was significantly larger than that of the preoperative value. Therefore, surgeons using navigation systems should guard against the possibility of oversizing when determining the size of the femoral component.

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PubMed2003

Bone marrow edema syndrome associated with uterine myoma: a case report.

A patient with bone marrow edema syndrome of the hip associated with a uterine myoma is presented. A 51-year-old woman could not walk because of severe pain in both hips and had been referred to the authors' institute. Magnetic resonance imaging scans showed abnormal intensity on T1- and T2-weighted images in both femoral heads and a large mass arising from the uterus which was diagnosed as a uterine myoma. A 99mTc-methylene diphosphonate scintigraph showed diffuse uptake in both femoral heads. The pain in both hips decreased shortly after a hysterectomy and the patient could walk without crutches within 2 weeks after the gynecologic surgery. Magnetic resonance imaging scans taken 8 months after surgery showed high signal intensity on T1- and T2-weighted images, indicating normal bone marrow in the femoral heads. To the authors' knowledge, this is the first case report showing a bone marrow edema syndrome of the hip associated with uterine myoma. The pathophysiologic mechanisms for bone marrow edema syndrome of the hip in the current patient and in pregnancy may be identical. More specifically, a large intrapelvic mass may cause an increase of intrapelvic pressure and subsequent blood stasis in both conditions. The current case suggests the possible factors of bone marrow edema syndrome of the hip which need to be investigated.

Bone Marrow Diseases↗

PubMedDate not supplied

Enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty in the presence of kyphosis.

BACKGROUND CONTEXT: In cranio-vertebral junction, retro-odontoid pseudotumor without evidence of rheumatoid arthritis is a rare condition. PURPOSE: To discuss the mechanism of enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty as a predictable complication. STUDY DESIGN: We report a rare case of an elderly man with non-inflammatory retro-odontoid pseudotumor after cervical expanding laminoplasty. PATIENT SAMPLE: A 76-year-old man presented with progressive quadriparesis of two week's duration caused by enlarging retro-odontoid soft tissue mass after cervical laminoplasty. OUTCOME MEASURES: Pre- and postoperative image, including X-ray and MRI, and the Japanese Orthopaedic Association scores for cervical myelopathy were assessed. METHODS: The patient subsequently underwent resection of the posterior arch of the atlas and posterior fusion from the occiput to C6 using Olerud system without removal of the retro-odontoid soft tissue mass. RESULTS: One year after surgery, the Japanese Orthopaedic Association scores for cervical myelopathy improved from 1 to 10 points, and postoperative MRI showed a mild reduction in the size of the retro-odontoid soft tissue mass. CONCLUSIONS: The kyphotic stability from C3 to C7 after laminoplasty, leading to a compensatory hyperlordosis at the occipitocervical junction, may cause the development of a degenerative osteoarthritic change, resulting in the production of an enlarging mass. Not only posterior compression of spinal cord due to posterior arch of the hyperextended atlas but also anterior compression of spinal cord due to retro-odontoid pseudotumor probably triggered the severe myelopathy. Laminoplasty may be inappropriate in cervical myelopathy with kyphosis.

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