Gait oscillation analysis during gait and stair-stepping in elder patients with knee osteoarthritis.

BACKGROUND: Evaluation of knee and lower limb function alone is not sufficient to assess gait. For accurate assessment of gait abnormality, gait oscillation should also be measured. The goal of this analysis was to assess the influence of the knee joint on gait oscillation during gait and stair-stepping in patients with osteoarthritis of the knee. METHODS: In 33 patients diagnosed with knee osteoarthritis and 33 healthy adults as the control group, we examined acceleration (anterior and lateral directions) and gait barycentric factors (single-support phase and ratio of center of gravity maximum values) during gait and stair-stepping. RESULTS: Acceleration in the anterior direction in the sacral region was greater in healthy adults than in osteoarthritis (OA) patients during gait and stair-down. Acceleration in the anterior direction in the dorsal vertebral region was greater in OA patients than in healthy adults during (up and down) stair-stepping. Acceleration in the lateral direction in the sacral region was greater in healthy adults than in OA patients during stair-up. Acceleration in the lateral direction in the dorsal vertebral region was greater in OA patients than in healthy adults during stair-stepping. The single-support phase was close to 1 for gait and stair-stepping in healthy adults and OA patients. The single-support time was largely the same for gait and stair-stepping in healthy adults. On the other hand, the single-support time was longer for stair-stepping than for gait in OA patients. The ratio of the center of gravity maximum values was greater for the sacral region than for the dorsal vertebral region. There was a significant difference in the stair-stepping ratio of the center of gravity maximum values between healthy adults and OA patients for the sacral region. CONCLUSION: We considered that knee OA influenced acceleration in the anterior and lateral direction in the dorsal vertebral and the ratio of the center of gravity maximum values on gait oscillation.

Kinematic analysis of posterior-stabilized total knee arthroplasty during standing up from and sitting down on a chair.

BACKGROUND: Total knee arthroplasty is effective to regain quality of life. Standing up from and sitting down on a chair and stair stepping motion are important in daily living. We previously reported in vivo kinematics of this implant during a stepping exercise. The purpose of this analysis was to assess in vivo knee motion during standing up from and sitting down on a chair and determine the motion pattern in patients with the unique knee prosthesis. METHODS: A total of 15 patients implanted with Bi-Surface PS were assessed during standing up from and sitting down on a chair. The Bi-Surface PS knee is a posterior-cruciate substitute prosthesis with a unique ball-and-socket joint in the mid-posterior portion of the femoral and tibial components. Patients were examined during standing up from and sitting down on a chair using a two-dimensional to three-dimensional registration technique. RESULTS: During standing up from and sitting down on a chair from minimum to 30° knee flexion, anterior femoral translation was slight. From 30° knee flexion to maximum flexion, the kinematic pattern was a medial pivot and rollback. CONCLUSIONS: This study demonstrated that the knee motion kinematic patterns observed in this study were not similar to normal knee kinematics and derived from the unique design of the Bi-Surface PS.

In vivo kinematics of a unique posterior-stabilized knee implant during a stepping exercise.

BACKGROUND: Stair-stepping motion is important in daily living, similar to gait. Knee prostheses need to have even more superior performance and stability in stair-stepping motion than in gait. The purpose of this analysis was to estimate in vivo knee motion in stair stepping and determine if this unique knee prosthesis function as designed. METHODS: A total of 20 patients with Bi-Surface posterior-stabilizing (PS) implants were assessed. The Bi-Surface PS knee is a posterior-cruciate substitute prosthesis with a unique ball-and-socket joint in the mid-posterior portion of the femoral and tibial components. Patients were examined during stair-stepping motion using a 2-dimensional to 3-dimensional registration technique. RESULTS: The kinematic pattern in step up was a medial pivot, in which the level of anteroposterior translation was very small. In step down, the kinematic pattern was neither a pivot shift nor a rollback. From minimum to maximum flexion, anterior femoral translation occurred slightly. CONCLUSIONS: In this study, this unique implant had good joint stability during stair stepping. The joint's stability during stair stepping was affected by the design of the femorotibial joint rather than post/cam engagement or the ball-and-socket joint.

Gait parameters in women with bilateral osteoarthritis after unilateral versus sequential bilateral total knee arthroplasty.

PURPOSE: To compare gait parameters in women after unilateral total knee arthroplasty (TKA) versus sequential bilateral TKA to determine the need for sequential TKA. METHODS: 35 women aged 60 to 74 (mean, 70) years with bilateral varus knee osteoarthritis (OA) underwent unilateral (n=23) or sequential bilateral (n=12) TKA by a single surgeon. All patients underwent unilateral TKA; 12 patients then underwent sequential TKA after 3 to 6 months of the first TKA. Gait parameters (step length, step width, gait velocity, single support phase value, and the maximum centre of gravity ratio) were compared before and after TKA, and between patients with unilateral versus bilateral TKA. RESULTS: Patients with sequential bilateral TKA had more severe OA in their contralateral knee than patients with unilateral TKA. In patients with unilateral and sequential bilateral TKA respectively, the mean step width differed at postoperative one month (12.9 vs. 19.1, p<0.01) and 3 months (11.9 vs. 16, p=0.03), and the mean maximum centre of gravity ratio differed at postoperative 3 months (2.43 vs. 1.75, p=0.02), whereas the mean step length, mean gait velocity, and mean single support phase values did not differ significantly between groups. CONCLUSION: After unilateral TKA, contralateral TKA may not be necessary in some patients whose gait has improved.

Collagen expression in various degenerative meniscal changes: an immunohistological study.

PURPOSE. To examine changes in acid mucopolysaccharides and collagen expression during meniscal degeneration, tearing, and repair, using menisci excised from knee joint surgeries. METHODS. Menisci excised from 23 patients aged 15 to 80 years who underwent meniscal surgery for flap and bucket handle tears (n=11) and total knee arthroplasty (TKA) for osteoarthritis (n=12) were examined histologically. Staining images were converted to greyscale images to measure the mean grey levels, which indicated densitometry. Comparisons were made between acutely injured menisci and menisci with and without degeneration (from patients with osteoarthritis) in terms of acid mucopolysaccharides, collagen types I, II, and III expression. RESULTS. In menisci with no degeneration, acid mucopolysaccharides, collagen types I and II were expressed throughout the entire meniscus except for the circulating area. Collagen type III was intensely expressed at the exterior peripheral border and on the surface. During progression of meniscal degeneration, the expression of acid mucopolysaccharides increased, and the expression of collagen types I, II, and III decreased. In acutely injured menisci, collagen types II and III disappeared first, followed by collagen type I, resulting in the abrogation of fibre construction. CONCLUSION. In normal menisci, acid mucopolysaccharides and collagen types I, II, and III were well-balanced, and meniscal function was maintained. When the limits of repair were exceeded, the meniscus tissue deteriorated owing to the disappearance of collagen types II and III and a decrease in collagen type I, resulting in the abrogation of meniscus fabric construction.

Shelf syndrome of the knee in elderly people: a report of three cases.

Shelf syndrome occurs mainly in younger people (particularly athletes) and rarely in elderly people. We report on 3 elderly patients with a medial synovial plica causing severe pain and locked knees. They had had no symptoms in their early or middle life. After removal of the shelf, the symptoms improved considerably. Although shelf syndrome is rare in the elderly, it should be suspected whenever severe pain and a locked knee are present.

Intra-articular synovial cyst of the knee joint: a case report.

Synovial cysts occur secondary to injury, mucinous degeneration or tumours. We report a patient with snapping of the knee joint caused by a synovial cyst located near the patellofemoral joint which developed as a result of minor trauma.

Production of rice protein by alkaline extraction improves its digestibility.

Rice seed endosperm has two types of protein bodies (PB). Type I protein body (PB-I) accumulates prolamin and is hard to digest, while type II protein body (PB-II) mainly consists of glutelin, an easily digestible protein. A simple method to process rice protein and improve its digestibility was tested from the viewpoint of its application to food manufacturing. Rice protein prepared by alkaline extraction followed by neutralization sedimentation (AE-RP) was compared with that prepared by starch degradation by alpha-amylase (SD-RP). The crude protein content of AE-RP and SD-RP was 84.7% and 78.2%, respectively. There were no major differences in protein composition among AE-RP, SD-RP and rice flour by SDS-PAGE, except 16 kDa polypeptide. With respect to amino acids, all the groups showed quite similar compositions, although cysteine and methionine were lower in AE-RP. In an in vitro digestion study with pepsin and pancreatin, both the SDS-PAGE analysis of protein pattern and the crude protein content of undigested residue clearly demonstrated that AE-RP has a higher digestibility than SD-RP. To find the cause of the difference in digestibility, the structural property of protein bodies by two production methods was compared using electron microscopy. PB-II of AE-RP was transformed into small, amorphous granules, while that of SD-RP was still kept partial protein body structures. PB-I of AE-RP kept its protein body structure, but produced double layers. From the finding that glutelin-gold was detected by immunochemistry not only in small, amorphous granules but also in PB-I, mainly the cortex layer, in AE-RP, it became clear that PB-I was swollen and fragile as a result of alkali treatment. These results strongly indicate that the improvement in digestibility of AE-RP is a result of the structural change of PB-I and -II caused by alkaline extraction.