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Biomedical subjects

Y Matsusue

Publications and source records attributed to Y Matsusue.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effect of rotational alignment on patellar tracking in total knee arthroplasty.

Forty-four consecutive patients (65 knees) who underwent identical condylar type total knee arthroplasty were evaluated retrospectively. In 22 of the patients (32 knees), the femoral component was set parallel to the posterior condylar axis (neutrally aligned group). In the remaining 22 patients (33 knees), it was set in an external rotation position of 3 degrees to 5 degrees relative to the axis (externally aligned group). Of the total knee arthroplasties in the neutrally aligned group, 34% required lateral release, compared with only 6% in the externally aligned group; patellar tracking in the externally aligned group was significantly better than that in the neutrally aligned group. Postoperative measurements performed using computed tomography scans showed that the mean angle between the prosthetic posterior condylar axis and the transepicondylar axis was 7.9 degrees in the neutrally aligned group and 3.2 degrees in the externally aligned group. The external rotation setting of the femoral component diminished the need for lateral retinacular release and may decrease the rate of patellofemoral complications that occur after total knee arthroplasty.

Adult↗
PubMed1999

Osteonecrosis of the resurfaced patella following bilateral total knee arthroplasty. A case report and review of the literature.

A 77-year-old woman with severe varus and flexion deformity of both knee joints, hypertension, and arteriosclerosis underwent bilateral total knee arthroplasty. Six weeks after the operation on the right knee and four months after the operation on the left knee, osteolysis of the patellas was seen on the radiographs. Three years after the operations, the lateral and inferior poles of both patellas were sclerotic and displaced. There was no knee pain and no extension lag throughout the follow-up period. This case suggests that the prognosis of patellar osteonecrosis after total knee arthroplasty is good if the continuity of the retinaculum and the extensor mechanism are preserved, and if instability of the knee does not occur.

Aged↗
PubMed1998

Treatment of osteomyelitis with antibiotic-soaked porous glass ceramic.

We have developed a new drug delivery system using porous apatite-wollastonite glass ceramic (A-W GC) to treat osteomyelitis. A-W GC (porosity, 70% and 20% to 30%), or porous hydroxyapatite (HA) blocks (porosity 35% to 48%) used as controls, were soaked in mixtures of two antibiotics, isepamicin sulphate (ISP) and cefmetazole (CMZ) under high vacuum. We evaluated the release concentrations of the antibiotics from the blocks. The bactericidal concentration of ISP from A-W GC was maintained for more than 42 days, but that from HA decreased to below the detection limit after 28 days. The concentrations of CMZ from both materials were lower than those of ISP. An in vivo study using rabbit femora showed that an osseous concentration of ISP was maintained at eight weeks after implantation. Osteoconduction of the A-W GC block was good. Four patients with infected hip arthroplasties and one with osteomyelitis of the tibia have been treated with the new delivery system with excellent results.

Adult↗
PubMed1998

A-W glass ceramic as a bone substitute in cemented hip arthroplasty: 15 hips followed 2-10 years.

We retrospectively reviewed hip arthroplasties in 13 patients (15 hips), in whom we had used apatite-wollastonite (A-W) glass ceramic together with auto- or allograft for augmentation of severe bone deficiency. 11 cemented sockets and 4 stem revisions were included and followed for 2-9.6 years. There were no radiolucent lines between A-W glass ceramic and surrounding bone, and remodeling of the bone graft containing A-W glass ceramic was observed. No migration of cemented sockets was seen except in 1 case, which was revised. In this case, direct bonding between bone and A-W glass ceramic granules was present histologically. In 4 stem revisions, 5 mm subsidence occurred in 1 case. However, the stem became stable and remodeling of the grafted bone occurred. An artificial bone material, such as A-W glass ceramic, can be used under high-load conditions, because of its good mechanical properties.

Adult↗
PubMed1998

Ganglia of the posterior cruciate ligament. A report of three cases and a review of the literature.

Two cases of isolated symptomatic ganglia and one case of a combined asymptomatic ganglion arising from the posterior cruciate ligament (PCL) are reported. One patient was a 29-year-old male who complained of posteromedial radiating knee pain. The medial McMurray test was positive. A cystic mass, 1.5 cm in diameter, arising from the femoral insertion of the PCL was removed piece-by-piece. The second case involved a 29-year-old female who complained of medial knee pain and limitation of flexion. MR scans detected a soft mass around the PCL. This was found to be a ganglion cyst surrounding the PCL, measuring 30 mm by 25 mm; it was excised using a power shaver. The third patient was a 17-year-old male who had knee pain due to a large medial synovial plica. Two small cystic masses were present on the intermediate portion of the PCL, but they seemed to be asymptomatic because of their small size. Whether or not a ganglion produces symptoms is determined by its size and location. Intra-articular ganglia can be cured by piecemeal resection and do not recur.

Adolescent↗
PubMed1997

Septum-like structures in lipoma and liposarcoma: MR imaging and pathologic correlation.

OBJECTIVE: To investigate the septum-like structures in predominantly lipomatous tumors, by correlating fat-suppressed MR images with histopathologic findings. DESIGN AND PATIENTS: The MR findings of three cases of well-differentiated liposarcoma (atypical lipoma), one case of lipoma-like component of dedifferentiated liposarcoma, and nine cases of lipoma were analyzed. T1-, T2-, and fat-suppressed T1-weighted images after Gd-DTPA administration were obtained. Surgical specimens from five patients (four with liposarcoma and one with lipoma) were also scanned with a MR unit, and compared with the pathologic findings. RESULTS AND CONCLUSIONS: Enhancement features of lipoma and liposarcoma were well visualized on fat-suppressed T1-weighted images after Gd-DTPA administration. The septum-like structures of liposarcoma are thick and enhanced considerably, while septa of lipoma are thin and enhanced only slightly. Pathologically, the septum-like structures of liposarcoma contained muscle fibers and the septa of lipoma represented fibrous capsule. Identification of well-enhanced septa in a predominantly lipomatous tumor helps to differentiate malignant tumors from lipomas. As the septum-like structures of liposarcoma contain a skeletal muscle component the tumor might need more extensive surgical procedures including resection of adjacent muscles.

Aged↗
PubMed1997

A long-term clinical study on drawn poly-L-lactide implants in orthopaedic surgery.

We have developed an ultra-high-strength drawn poly (L-lactide) (PLLA) with a bending strength of 240 MPa. Seventy-four patients (80 cases) who were treated with this PLLA implant were enrolled in this study. Their ages ranged from 14 to 78 years, and the follow-up period ranged from 4 to 9 years (mean: 5.3 years). Bony union was obtained in all cases. Osteolytic changes were observed in 12 cases (15%) but no late aseptic swelling was noted. Both MRI and roentgenographic findings indicated that the spaces where the PLLA implants were located had not been replaced with bony tissue.

Adolescent↗
PubMed1997

Improved range of flexion after total knee arthroplasty. The total condylar knee versus the KU knee.

One objective of the modification of the total condylar knee is to increase the range of flexion without compromising the durability of the prosthesis. The KU knee prosthesis was designed to improve postoperative range of motion. This prosthesis has a unique ball-and-socket joint in the center of the posterior portion of the femorotibial articulation. A retrospective comparative study was undertaken to determine whether the KU knee prosthesis had achieved its design objectives. The study was based on the clinical observation of two populations: one (the TC group: 31 joints) with total condylar prostheses and the other (the KU group; 31 joints) with KU knee prostheses. At two years postoperatively, the mean postoperative range of flexion was 94 degrees (range: 60 degrees to 120 degrees) in the TC group and 120 degrees (range: 95 degrees to 150 degrees) in the KU group. The mean postoperative range of flexion was 24 degrees better in the KU group than in the TC group (p < 0.01). The mean functional score was 76 points (range: 61 to 86) in the TC group and 81 points (range: 56 to 92) in the KU group. There were no statistically significant difference in pain, walking ability, deformity, extension lag, and activities of daily living (ADL) score between the two groups. However, a statistically significant difference was detected in the range of motion (ROM) score (p < 0.01). No major complications occurred in either of the two groups. Although the follow-up period was not long enough, the KU knee was thought to be a promising modification of the total condylar knee prosthesis.

Activities of Daily Living↗
PubMed1996

Arthroscopic partial medial meniscectomy in patients over 40 years old: a 5- to 11-year follow-up study.

A retrospective analysis of 68 knees from 65 patients older than 40 years, who had undergone a partial medial meniscectomy, was carried out. The average age of the patients was 49.7 years (range, 40 to 74), and the mean follow-up period was 7.8 years (range, 5 to 11). The patients were divided into two groups based on the degree of articular cartilage degeneration. Group I consisted of 53 knees that did not have any significant articular cartilage damage beyond grade I or II. Group II consisted of 15 knees that had grade III or IV cartilage damage. Overall, excellent results were obtained in 44 patients (47 knees), good results in 10 patients, fair results in six patients, and poor results in five patients. In group I, 46 knees (87%) had an excellent outcome, and only one patient had a poor result. In contrast, patients in group II had significantly worse results, with only one knee (7%) having excellent outcome, and four knees had a poor result. A specific history of trauma did not affect the clinical outcome. Forty-two patients (64%) were able to resume normal athletic activities without any restrictions. Arthroscopic partial medial meniscectomy in patients older than 40 years is an acceptable and effective long-term treatment, particularly in patients without significant articular cartilage damage.

Adult↗
PubMed1996

Biodegradable pin fixation of osteochondral fragments of the knee.

The authors present 3 cases of osteochondritis and 2 cases of osteochondral fracture of the knee. These cases were treated with a bioabsorbable ultra high strength poly (L-lactide) pin, which has the highest mechanical strength value of any nonfiber reinforced poly (L-lactide) reported previously. Three of the patients were male, and 2 were females; their ages ranged from 12 to 21 years. The followup period ranged from 2 years to 7 years 9 months (mean, 4.1 years). Two to 4 poly (L-lactide) pins with a diameter of 2 mm were used to fix the osteochondral fragments or the transplanted autogenous osteochondral grafts. In all cases, satisfactory bone union was obtained, and no inflammatory reaction was observed during the entire followup periods. The ranges of motion were normal, and there was no pain in any of the cases. It is concluded that the poly (L-lactide) pin is safe and useful in the repair of osteochondral fractures of the knee and in fixing grafted osteochondral fragments.

Adolescent↗
PubMed1995

Biodegradable plate fixation of rabbit femoral shaft osteotomies. A comparative study.

Femoral shaft transverse osteotomies in 58 rabbits were fixed with ultrahigh strength poly-L-lactic acid plates made by a drawing technique. Similar osteotomies in another 35 rabbits were fixed using stainless steel plates. The union rate, the mechanical strength of the united bones, bone mineral content and density in the area beneath the plate using dual energy x-ray absorptiometry, and the cortical thickness beneath and opposite the plate using a digitizer was compared between the poly-L-lactic acid and stainless steel groups after postoperative periods of 8, 25, and 40 weeks. The poly-L-lactic acid and stainless steel groups showed union rates of 67% (39 of 58) and 80% (28 of 35) without displacement, respectively. In the poly-L-lactic acid group, plate failure occurred in 14% (8 of 58). The mechanical strength of the specimen was restored to a level equal to that on the untreated side by 25 weeks, and cortical thickness and bone mineral content and density were maintained almost normal for 40 weeks in the poly-L-lactic acid group. The stainless steel group showed significantly lower mechanical strength and led to osteopenia because of stress shielding after 25 weeks.

Animals↗
PubMed1995

Tissue reaction of bioabsorbable ultra high strength poly (L-lactide) rod. A long-term study in rabbits.

Bioabsorbable ultra high strength poly (L-lactide) rods, which were developed for internal fixation of fractures, were fabricated using a drawing technique. These rods were implanted in the subcutaneous tissue and in the medullary cavity of rabbits to investigate tissue reactions to poly (L-lactide) and to study their degradation process. After 18 months, histiocytes were found, and their phagocytic activity continued for as long as 42 months, with maximum activity observed between 24 and 36 months after implantation. At 62 months after intramedullary implantation, the materials had been absorbed almost completely and were replaced by bone marrow cells, with only a small amount of residual tissue reaction. At 69 months after subcutaneous implantation, the materials had been absorbed completely without any scar formation. During degradation, no foreign body giant cells were found and osteolytic expansion caused by liquid degradable materials was not seen.

Animals↗
PubMed1994

Bioabsorbable osteosynthetic implants of ultra high strength poly-L-lactide. A clinical study.

We have developed reasonably strong but bioabsorbable osteosynthetic screws, pins and nails made of ultra high strength poly-L-lactide (PLLA) and evaluated their use in 143 patients. The PLLA implants have the highest strength among those reported to date. They lose about 10% of their initial strength within 8 weeks, about 40% within 4 weeks and nearly 100% within 20 weeks in vivo. The patients were aged from 9 to 78 years, and the follow up was from 2 to 6 years. The implants were used for fixation of bone grafts in 84 patients, peri- and intra-articular fractures in 49, after osteotomy in 8, and in 2 others. Bony union was not achieved in only one case. In the early stages of the study, breakage of screws occurred in 12 cases (8%), mostly because of an inappropriate size of tap; these problems have not occurred after improvement of the tapping system. There were no cases with abnormal blood tests, infection or foreign body reaction.

Adolescent↗
PubMed1994

Symptomatic type D (separated) medial plica: clinical features and surgical results.

The clinical presentation and results of surgery in 20 cases of symptomatic type D (separated) medial plica were reviewed. The group was composed of cases with a fenestration (14 knees), reduplication (two knees), and tear (four knees). Based on preoperative symptoms and clinical presentation, the patients were divided into two groups: the first group had symptoms localized to the medial compartment (11 knees), and the second group had symptoms and/or signs in the patellofemoral joint and/or lateral compartment (nine knees). The symptoms of the second group mimicked those of lateral meniscal tear or patella subluxation, and no definite preoperative diagnosis was possible. Two patients showed difficulty of full extension "active extension test." Excellent or good results were obtained with surgery in all patients after an average follow-up of 39 months. Although resection of the type D medial plica resulted in a favorable outcome, special attention should be made in preoperative diagnosis of this type of plicae.

Adolescent↗
PubMed1993

The application of titanium alloy wires for the reattachment of the greater trochanter in total hip arthroplasty.

We developed a new fixing method using titanium alloy wires in order to facilitate the attachment of the greater trochanter in total hip arthroplasty. This wire is composed of Ti-3Al-2.5V by weight. According to the fatigue test in vitro, the titanium alloy wire had better fatigue properties than Ortron 90 wire of the same diameter. In experiments in vivo, both titanium alloy wires and SUS-316L wires were used for the reattachment of the greater trochanter of dogs, and the titanium alloy wires showed better biocompatibility than the latter. Thus, titanium alloy wires seem applicable for the reattachment of the greater trochanter in human total hip arthroplasty.

Alloys↗
PubMed1993

Arthroscopic multiple osteochondral transplantation to the chondral defect in the knee associated with anterior cruciate ligament disruption.

Treatment of a chondral lesion in the knee, associated with anterior cruciate ligament disruption, is known to be difficult and controversial. This article presents an arthroscopic technique for transplantation of multiple osteochondral fragments, harvested from the same knee, to this chondral lesion. A 3-year follow-up shows excellent results with good cartilage repair confirmed by second-look arthroscopy.

Adult↗