Tomonori Yagi

Tibial torsion in patients with medial-type osteoarthrotic knees.

Computed tomography (CT) measurements of torsion of the lower extremities were evaluated in 85 knees of 68 patients with medial-type osteoarthrotic knees and in 24 normal knees of 13 adults. In addition, segmental tibial torsion and CT density of the third lumbar vertebra, reflecting general osteoporosis, were measured. Although there were no differences in the degrees of femoral torsion or knee joint rotation, external tibial torsion in the 68 patients was observed to have a mean value of 11.3 degrees, significantly smaller than the 23.5 degrees observed in the 13 normal adults (p < 0.01). Lateral torsion was 14.1 degrees in mild, 11.9 degrees in moderate, and 7.5 degrees in severe stages of osteoarthrosis. The rate of decrease in lateral tibial torsion was 59.6% in the proximal tibia, 4.2% in the tibial shaft, and 36.2% in the distal tibia. The decrease of lateral tibial torsion was correlated with decrease of CT density of the third lumbar vertebra. There is a correlation between reduction of lateral torsion with the radiographic stage of osteoarthrosis of the knee and general osteoporosity.

Transepiphyseal plate osteotomy for severe tibia vara in children: follow-up study of four cases

Transepiphyseal plate osteotomy of the medial tibial condyle was performed in three children (four knees) with severe progressive tibia vara and excessive ligamentous laxity. Two knees with Blount disease underwent tibial valgus osteotomy and epiphysiodesis associated with transepiphyseal plate osteotomy, and two knees with pseudoachondroplasia underwent tibial valgus osteotomy. Follow-up study at the time of skeletal maturity revealed satisfactory alignment of the leg, favorable congruity of the joint, and good ligamentous stability in all cases. Our experience indicates that the present procedures are excellent, although there are very few documented cases and almost no description of the postoperative clinical courses.

Spindle-cell sarcoma in patients who have osteochondromatosis. A report of two cases.

Spindle-cell sarcoma in patients who have osteochondromatosis. A report of two cases. T Matsuno;Y Ichioka;T Yagi;S Ishii; The Journal of Bone & Joint Surgery

Tunnel Enlargement and Coalition After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autografts A Computed Tomography Study

Background: Tunnel enlargement and coalition following double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring tendon autografts has not yet been sufficiently studied. Hypothesis: The incidence and the degree of femoral tunnel enlargement will be significantly greater than those for tibial tunnel enlargement after anatomic double-bundle ACL reconstruction using hamstring tendon autografts. There will be no significant correlation between tunnel enlargement and coalition and the postoperative knee laxity. Study Design: Case series; Level of evidence, 4. Methods: Thirty-nine patients who underwent anatomic double-bundle ACL reconstruction using semitendinosus and gracilis tendon autografts were followed up for 1 year after surgery. The grafts were simultaneously fixed at 10° of knee flexion with EndoButtons and spiked staples. All patients were examined with computed tomography and the standard clinical evaluation methods at 2 weeks and 1 year after surgery. Results: The degree of tunnel enlargement of the femoral anteromedial and posterolateral tunnels averaged 10% to 11% and 7% to 9%, respectively, while that of the tibial anteromedial and posterolateral tunnels averaged 3% to 7% and 1% to 6%. The degree and incidence of the anteromedial and posterolateral tunnel enlargement were significantly greater in the femur than in the tibia (P < .0335 and P < .0405, respectively). On the femoral and tibial intra-articular surface, tunnel outlet coalition was found in 5% and 77% of the knees, respectively, at 1 year after surgery. There was no significant correlation between tunnel enlargement and coalition and the clinical outcome. Conclusion: The incidence and the degree of each tunnel enlargement in the femur were significantly greater than that in the tibia. However, the incidence of tunnel coalition in the femur was significantly less than that in the tibia after double-bundle ACL reconstruction with a transtibial technique. There was no significant correlation between tunnel enlargement and coalition and the clinical outcome. Clinical Relevance: The present study provides orthopaedic surgeons with important information on double-bundle ACL reconstruction with hamstring tendons.

Characteristics of human soft tissue sarcomas in xenografts and in vitro.

Two permanent, transplantable strains of rhabdomyosarcoma (SAS) and synovial sarcoma (KUSHI) were established by transplanting them serially into nude mice. The original SAS tumor and its transplant were histologically identical and gave an appearance of so-called embryonal rhabdomyosarcoma. The KUSHI tumor changed after the second passage, showing the biphasic pattern of synovial sarcoma, while undifferentiated myoblast-like cells were observed throughout the original tumor. Three in vitro cell lines from the SAS and one from the KUSHI tumor were successfully established. The human origin of the SAS and KUSHI transplanted tumors could be verified by the presence of human chromosomes. The cells cultured from the SAS tumor were more sensitive to anticancer drugs than those of the KUSHI tumor. However, as the number of serial passages on nude mice increased, the sensitivities of the SAS cells decreased, while those of the KUSHI cells increased. The modal chromosome number of the SAS tumor changed from 51 to 49 to 46 during serial passages on nude mice. These observations suggest that the sensitivities to anticancer drugs not only differ among soft tissue sarcomas of different histologic types, but also change continuously during the growth of the tumor itself.

HIGH-GRADE SURFACE OSTEOSARCOMA OF THE LEFT ILIUM A Case Report and Review of the Literature

A rare case of high‐grade surface osteosarcoma of the left ilum is reported. Trephine biopsy performed on a 31‐year‐old woman suffering from a huge tumor of the left buttock revealed high‐grade osteosarcoma, and hemipel‐vectomy was undertaken. The surgical specimen showed that the tumor was present on the surface of the left ilium. Ten months after the operation, the patient died of brain metastasis. From these results, we considered this case to be one of high‐grade surface osteosarcoma. ACTA PATHOL JPN 38: 235 ‐240, 1988.

Clinical Results of Kinematic Total Knee Replacement

The kinematic knee prostheses are intended as a “graduating system” and consist of four different types. We can choose a favorable type of prosthesis at the time of surgery depending on the severity of the pathological condition of the knee joint. We performed 225 kinematic knee replacements and followed up 201 knees (101 rheumatoid, l00 osteoarthritic).

Double-Bundle Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Hybrid Grafts in Patients Over 40 Years of Age : Comparisons Between Different Age Groups

Background: Several recent studies have reported that favorable clinical results and a high level of patient satisfaction can generally be obtained with no increased risk of complications after single-bundle anterior cruciate ligament (ACL) reconstruction performed in patients >40 years of age. However, no studies have yet clarified the age-based differences in clinical outcomes after double-bundle reconstruction. Purpose: To compare clinical outcomes after double-bundle ACL reconstruction using hamstring tendon hybrid grafts between patients in 2 different age groups: ≥40 years and <40 years. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective study was conducted using 96 patients (48 men, 48 women ; mean age, 37 years) who underwent unilateral ACL reconstruction between 2008 and 2011. These patients were divided into 2 groups: group M included patients ≥40 years of age (n = 40 patients), and group Y included patients <40 years of age (n = 56 patients). All patients underwent the same anatomic double-bundle ACL reconstruction procedure. Clinical outcomes were evaluated at 2 years after surgery. Tunnel enlargement was also evaluated by computed digital radiography at 1 week and 2 years after surgery. Results: Mean postoperative side-to-side differences in anterior laxity were 0.5 ± 1.9 mm and 1.2 ± 1.5 mm in groups M and Y, respectively; there was a significant difference between the 2 groups (P = .039). There were no significant differences between the groups in Lysholm knee scores, International Knee Documentation Committee (IKDC) scores, or peak muscle torque of the hamstring. On the other hand, peak muscle torque of the quadriceps was significantly lower in group M (81%) than in group Y (89%) (P = .025). With respect to femoral tunnel enlargement, the posterolateral tunnel in group M was significantly larger than that in group Y on anteroposterior and lateral radiographs (P = .015 and P = .002, respectively). Conclusion: Equivalent clinical outcomes were seen between the 2 age groups after double-bundle ACL reconstruction. Postoperative anterior laxity was significantly less in older patients than in younger patients, however, older patients had significantly less quadriceps muscle strength than younger patients. Surgeons should be aware of residual muscle weakness and tunnel enlargement when performing double-bundle ACL reconstruction in older patients.

Inverted V–Shaped High Tibial Osteotomy for Medial Osteoarthritic Knees With Severe Varus Deformity

A hemi–closing-wedge and hemi–opening-wedge, inverted V–shaped high tibial osteotomy with local bone graft has been reported to be an effective surgical procedure for medial osteoarthritis of the knee. In this procedure, an inverted V–shaped osteotomy is made and a thin wedged bone block is resected from the lateral side and implanted in the medial opening space created after valgus correction. This procedure can provide sufficient valgus correction of the knee with severe varus deformity more easily than can closing-wedge high tibial osteotomy. The inverted V–shaped osteotomy does not change the posterior tibial slope, the patellar height, or the length of the lower limb at all because the center of tibial alignment correction by the inverted V–shaped osteotomy is located near the center of rotation of angulation of the lower-limb deformity. We recently modified this procedure by performing biplanar osteotomy, developing useful cutting guides, and fixing the tibia with a lateral locking compression plate. The surgical technique is described to enable the reproducible creation of the hemi–closing-wedge and hemi–opening-wedge, inverted V–shaped osteotomy with the locking plate for medial osteoarthritic knees with moderate or severe varus deformity.

Is the Grafted Tendon Shifted Anteriorly in the Femoral Tunnel at the Postremodeling Phase After Anterior Cruciate Ligament Reconstruction? A Clinical MRI Study:

Background: Based on previous in vitro studies, it has been commonly believed that during anterior cruciate ligament (ACL) reconstruction with hamstring tendon, the grafted tendon is shifted anteriorly in the tunnel permanently after the graft is anchored to the tunnel wall. However, this has not been proven by in vivo studies. Hypothesis: At 1 year after anatomic double-bundle ACL reconstruction, the grafted tendons may not be shifted anteriorly in the femoral tunnel but anchored to the bony wall at the center of the tunnel. Study Design: Case series; Level of evidence, 4. Methods: Participants consisted of 40 patients who underwent anatomic double-bundle ACL reconstruction. The grafted tendons located in the femoral tunnel were examined 1 year after surgery using 2 different magnetic resonance imaging (MRI) protocols. In the first substudy, with 20 patients, the grafted tendon location was evaluated on an inclined sagittal multiplanar reconstruction (MPR) image taken using a standard T2-weighted protocol. In the second substudy with the remaining 20 patients, tendon location was evaluated on a pure axial MPR image taken using a VISTA (volume isotropic turbo spin echo acquisition) protocol. Results: On the inclined sagittal T2-weighted images of the anteromedial (AM) graft, the anterior width of the newly formed fibrous tissue, which surrounded the tendon graft, was significantly greater than the posterior width (P = .001). The center of the grafted tendon was slightly (mean, 2.5% of the tunnel diameter) but significantly (P = .0310) shifted posteriorly from the tunnel center. On the axial T2-VISTA images, the center of the AM graft was slightly but significantly shifted posteriorly (3.9%; P = .022) and medially (5.5%; P = .002) from the tunnel center. The center of the posterolateral (PL) graft was not significantly shifted to any direction from the center of the tunnel. Conclusion: The grafted tendons were not shifted anteriorly in the femoral tunnel 1 year after anatomic double-bundle ACL reconstruction. The PL graft was located approximately at the center of the tunnel outlet, while the AM graft was slightly but significantly shifted posteriorly and proximally.