Biomedical subjects

Yasunobu Iwasaki

Publications and source records attributed to Yasunobu Iwasaki.

3 recordsLinked to original sources

PubMed2005

A comparison of bone-patellar tendon-bone and bone-hamstring tendon-bone autografts for anterior cruciate ligament reconstruction.

BACKGROUND: Most of the previous comparative studies between patellar tendon and hamstring tendon anterior cruciate ligament grafts compared grafts of different constructs fixed with different methods. PURPOSE: To compare patellar tendon and hamstring tendon grafts with the same fixation method used to reconstruct the anterior cruciate ligament. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: During the reconstructive procedure, the hamstring tendon graft was prepared as a bone-hamstring-bone graft; both bone-patellar tendon-bone and bone-hamstring-bone grafts were fixed with interference screws. Eighty consecutive patients who underwent anterior cruciate ligament reconstruction were randomly assigned to either bone-patellar tendon-bone or bone-hamstring-bone groups. Follow-up examinations were performed for at least 5 years postoperatively. Seventy-two of the 80 patients (37 patients in the bone-patellar tendon-bone group and 35 in the bone-hamstring-bone group) were evaluated, with a mean follow-up period of 87.0 and 80.8 months, respectively. Follow-up examinations were performed using the International Knee Documentation Committee knee ligament standard and subjective knee forms. RESULTS: The mean KT-1000 arthrometer evaluation results showed no significant difference between the bone-patellar tendon-bone and bone-hamstring-bone groups (1.2 +/- 2.1 mm and 1.7 +/- 1.4 mm, respectively; P = .24). However, symptoms related to graft harvest (anterior kneeling pain) were more frequently observed in the bone-patellar tendon-bone group, and unsatisfactory results were correlated with severe kneeling pain in 3 patients from this group (P = .0056). Significant hamstring muscle weakness without complaint of functional deficit was found in the bone-hamstring-bone group (P = .0045). CONCLUSION: Bone-hamstring-bone grafts were shown to reduce the risk of problems at the graft harvest site compared to bone-patellar tendon-bone grafts, with comparable results in the remaining clinical parameters tested.

Adolescent↗

PubMed2004

Traumatic anterior atlantoaxial subluxation occurring in a professional rugby athlete: case report and review of literature related to atlantoaxial injuries in sports activities.

STUDY DESIGN: This is a case report of traumatic anterior atlantoaxial subluxation occurring in a professional rugby athlete with a literature review. OBJECTIVE: To report a rare case of traumatic anterior atlantoaxial subluxation in a professional rugby athlete. SUMMARY OF BACKGROUND DATA: Atlantoaxial subluxation occurring in a professional athlete is very rare, and only two cases have been reported so far. METHODS: A 26-year-old professional rugby player sustained traumatic anterior atlantoaxial subluxation. The pathomechanism of the injury was hyperflexion. No quadriplegia existed, but severe anterior subluxation was found on functional radiographs and kinematic magnetic resonance imaging. RESULTS: Surgical fixation of C1-C2 was carried out, and no impairment was seen in his daily living, although he did not return to professional rugby. CONCLUSIONS: Anterior atlantoaxial subluxation in sports activities is very rare. The mechanism of this injury is hyperflexion, and the rupture of the transverse ligament is essential. Good prognosis has been reported; however, a return to high-level sports activities is thought to be a contraindication.

Adult↗

PubMed2003

MRI-negative rotator cuff tears.

We report two cases of rotator cuff tear in which the T(2)-weighted MRI signal was negative at the first examination, but positive by the second examination without any changes in symptoms. Many authors have reported on correlations between the MRI and operative findings of rotator cuff tears. However, MRI findings, history of symptoms and operative findings in our patients suggest that there was a discrepancy between symptoms and MRI findings dependent on the period from the injury. Operative findings also indicate that intratendinous tears might have occurred first in these patients then progressed to partial or full thickness tears over time. We concluded that physicians should keep rotator cuff pathology in mind even in patients whose MRI findings are negative but symptoms of rotator cuff tear persist.

Adult↗