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Standardized outcome measures are crucial for the evaluation of different treatment and rehabilitation regimes in patients after total knee arthroplasty (TKA). Performance-based measures are necessary to capture different aspects of physical function. High reliability and agreement of five performance-based measures were hypothesized to differentiate between measurement error and change in test performance. Secondary outcomes are the correlation of performance-based measurements to KSS and WOMAC prior to surgery (baseline) and 10 weeks thereafter (t3). Methods The test–retest reliabilities and agreements of the 1-m walk test, the stair-climbing test, the timed-up-and-go test, the weight-balanced-chair-rising test and the isometric maximum knee extension force in patients undergoing total knee replacements were studied. The intraclass correlation coefficient was calculated and a Bland–Altman analysis performed. The weight-balanced-chair-rising test showed a symmetry at baseline = 0.77, 5 ± 1 days after surgery (t1) = 0.50, 9 ± 1 days (t2)= 0.59 and (t3)= 0.80. All performance tests showed high intraclass correlation coefficients (ICC= 0.81–0.99). The 10-m walk test, stair climbing test, and the timed-up-and-go test showed high agreement in the Bland–Altman analysis. The Bland–Altman analysis for the weight-balanced-chair-rising test and isometric knee extension force indicated high
agreement at 5 and 9 days postoperatively, but the relative measurement error increased pre- and 10 weeks postoperatively.
In conclusion, symmetry, as an important outcome after TKA, is a reliable and rather unique item that should unquestionably be added to established measurements like walking tests or survey-based function assessment. The implementation of standardized performance-based measures to assess physical function in rehabilitation procedures will help to improve the more objectively based assessment of different rehabilitation protocols.
Kraftindex deutet bei Judoka 5 Jahre nach Kreuzbandruptur auf Muskelfaserspektrumsänderung hin
(2022)
Due to the high heterogeneity in outcome measures after total hip arthroplasty (THA), the prospective observational study investigated the relationships between symmetry-based (SBMs), performance-based (PBMs), and functional outcome measures in THA patients to determine necessary or redundant categories of tests. The study material consisted of 24 patients with end-stage hip osteoarthritis scheduled for THA. The patients were examined one day before surgery and consecutively on the 4th day, 9th day, and 10th week postoperatively using the SBMs (weight-bearing chair-rising test, measurements of the maximal isometric torque of the quadriceps muscle); the PBMs (10-m walk, timed up-and-go, and stair-climbing tests); and the functional outcome measure (Harris Hip Score). The results obtained in a given category of tests at different time points were compared, and the correlations between the tests were determined. The reliability of the outcome measures was determined. The results of tests in the studied categories statistically significantly (p < 0.05) improved at the 10th week postoperatively compared to preoperative results. No strong correlations were revealed between the three studied types of outcome measures in THA patients. Therefore, none of them can be considered redundant. It also means that the relevance of symmetry for a core measurement set to describe the domain function in THA patients must be further clarified.
A randomized crossover trial was designed to investigate the influence of muscle activation and strength on functional stability/control of the knee joint, to determine whether bilateral imbalances still occur six months after successful anterior cruciate ligament reconstruction (ACLR), and to analyze whether the use of orthotic devices changes the activity onset of these muscles. Furthermore, conclusions on the feedforward and feedback mechanisms are highlighted. Therefore, twenty‑eight patients will take part in a modified Back in Action (BIA) test battery at an average of six months after a primary unilateral ACLR, which used an autologous ipsilateral semitendinosus tendon graft. This includes double‑leg and single‑leg stability tests, double‑leg and single‑leg countermovement jumps, double‑leg and single‑leg drop jumps, a speedy jump test, and a quick feet test. During the tests, gluteus medius and semitendinosus muscle activity are analyzed using surface electromyography (sEMG). Motion analysis is conducted using Microsoft Azure DK and 3D force plates. The tests are performed while wearing knee rigid orthosis, soft brace, and with no aid, in random order. Additionally, the range of hip and knee motion and hip abductor muscle strength under isometric conditions are measured. Furthermore, patient‑rated outcomes will be assessed.
Knee osteoarthritis is the most prevalent joint disease worldwide and total knee arthroplasty (TKA) is often the only evidence-based treatment option left for patients with endstage osteoarthritis. The postoperative outcomes as well as the different rehabilitation procedures are most commonly evaluated by patient-reported outcome measurements (PROMs). However, in acute clinical-stage stages, performance-based measures were shown to yield greater responsiveness than PROMs, which failed to capture functional declines and may overestimate long-term functional improvements. Moreover, these tests represent a variety of daily life activities which helps to estimate whether a patient is functioning adequately prior to discharge from hospital and in the following rehabilitation. The ability to rise from a sitting position is one of those activities which is important for an elderly person to maintain an independent life. Also, it was shown that chair rising test performance is highly correlated with deviations in gait patterns. However, there is no data available yet if this test can be used at perioperative time-points in patients undergoing TKA and how reliable this test is. Therefore, this study investigates the reliability and the minimal detectable change and the development of the performance of the weight-balanced chair rising test in patients before and after TKA. This study was designed as a test-retest reliability study. Participants were recruited in an orthopedic hospital after they were scheduled for total knee arthroplasty. The participants performed two chair rising tests (five-times-sit-to-stand) on a ground reaction force plate at one-day preoperatively (M0), five days- (M1), ten days (M2)- and ten weeks postoperatively (M3). The test-retest reliability of the weight balanced asymmetry measured as ground reaction force in Newton was analyzed for each of the four time-points. Therefore, the minimal detectable change within a confidence interval of 95% (MDC95) and the ICC were calculated. 16 male and 8 female subjects (N=24) with a mean age of age 63,93 (±9,59) were included. The mean side-to-side difference in N was 138(±104) at M0, 319(±125) at M1, 254(±109) at M2 and 116(±74) at M3. The test-retest reliability ranged between ICC=.84-.96 at all four time points, indicating good to excellent reliability. The MDC95 ranges from 79–113 N. No adverse events were recorded after the performance of the test and no participants dropped out because of study-related reasons. The weight-balanced chair rising test shows good- to excellent reliability. After an initial decrease of loading symmetry at M1 and M2 preoperative levels are reached as early as at M3. The weight-balanced chair rising test provides objective data about loading symmetry during an activity of daily living. It is reliable and feasible to use in as well in-patient as out- patient rehabilitation of patients with TKA.
Human serum or FCS: Differentiation of human cartilage-like microtissues depends on serum selection
(2018)
Introduction: Regeneration of articular cartilage defects is limited. Hence, cell-based therapies for the treatment were developed using e.g. chondrocytes isolated from patient biopsies. For cell culture fetal calf serum (FCS) is often used as media supplement to establish engineering processes for transplants in regenerative medicine. However, the usage of xenogeneic serum could mask the intrinsic behavior of human cells in vitro. This could be particularly important for the dedifferentiation process during cell expansion and redifferentiation in 3D-culture. The aim of this study was to compare the development of microtissues derived from chondrocytes cultivated in presence of FCS with those cultivated in human serum (HS).
Material and Methods: Human articular chondrocytes isolated from knee joints were expanded in medium with HS or FCS. Scaffold-free microtissues were generated using the agar overlay technique. After four and eight weeks the macroscopic appearance (reflected-light microscopy) was documented and the size of the microtissues was determined. The differentiation degree was evaluated via histology to visualize typical glycosamino¬glycans (Safranin O, Alcian blue) and immunohisto¬chemistry (IH) to detect cartilage-specific markers (collagen type II, proteoglycans, COMP, Sox9) on cryosections.
Results and Conclusion: Cells from all donors in both medium compositions generated microtissues – but with distinct differences in the differentiation levels. Microtissues cultured in medium with FCS showed a higher differentiation level compared to microtissues in HS. This is evidenced by a higher amount of matrix resulting in bigger microtissues (diameter in FCS is 42% larger compared to HS) and a more cartilage-like composition of the matrix (not any/little colouring in HS versus intense staining in FCS). IH analysis showed the same pattern. Not any/less positivity for collagen type II, proteoglycan, COMP, and Sox9 in HS versus moderate-to-high positivity in FCS-cultured microtissues. Absolute values vary from donor to donor whereas an individualized expression profile only became visible in microtissues cultured in HS medium. HS should be preferred for the engineering of cartilage-like microtissues, as it rather enables a "human-based" situation in vitro.
Supported by „Gesundheitscampus Brandenburg“ and „Ministerium für Wissenschaft, Forschung und Kultur“, state of Brandenburg, Germany.
BACKGROUND: Tissue engineering has become a major field of research in biotechnology and biomedicine. As a consequence, cell-based therapeutic approaches are entering the hospitals, especially for skeletal regeneration. Traumatic injuries of cartilage are treated with autologous cell suspensions or in vitro generated cartilage tissues, but there is actually no therapy available for degenerative cartilage defects. However, Osteoarthritis (OA) is a major public health problem in the world affecting 240 million people globally.
OBJECTIVE: To develop suitable in vitro tissues, the properties of chondrogenic spheroids should be optimized via coculture with cells naturally occurring as joint neighbours.
METHODS: Human chondrocytes were isolated from condyles and propagated in monolayer culture. Scaffold-free spheroids were generated and co-cultured with joint-specific partner cells (osteoblast-like osteosarcoma cells, fibroblasts). Morphology and differentiation was analyzed using histochemistry (Alcian blue, Safranin O) and immunohistochemistry for cartilage markers (collagen type II, Sox9, proteoglycan), proliferation-associated protein (Ki67) and markers of connective tissue (collagen type I and actin).
RESULTS: The provision of a more natural microenvironment in vitro via co-culture of chondrocyte-based aggregates with osteoblast-like Saos-2 cells enhanced the differentiation potential of chondrogenic spheroids towards hyaline cartilage.
CONCLUSIONS: The study showed the positive influence of Saos-2 cells on the differentiation potential of human chondrocytes in co-culture.