The effect of knee arthroplasty on balancing ability in response to sudden unidirectional perturbation in the early postoperative period.

INTRODUCTION AND OBJECTIVE: Total knee arthroplasty (TKA) affects 1-3% of the entire population. The effectiveness of surgery and rehabilitation are of great significance. The goal of this study was to determine how different surgical methods (i.e., conventional and minimally invasive) influence balancing ability in response to sudden unidirectional perturbation during the first 12 weeks of the postoperative period. MATERIALS AND METHODS: The balancing capacity after sudden unidirectional (horizontal) perturbation of 10 patients who had undergone TKA operations via the conventional method and 10 patients who had undergone TKA operations via the minimally invasive method were examined before and six and 12 weeks after TKA. Forty-five health age-matched participants composed the control group. The balancing capacities following unidirectional perturbation were characterised by the Lehr's damping ratio, which was calculated based on the results of the provocation tests that were performed with the patients standing on both the affected and non-affected limbs. RESULTS: In both patient groups, the Lehr's damping ratios increased during the postoperative period. However, in both patient groups, the Lehr's damping ratios calculated from the results of all three of the testing methods decreased compared to values obtained from the controls even at 12 weeks postoperatively. Six and 12 weeks after TKA, the Lehr's damping ratios of the patients who underwent operations utilising the minimally invasive exposure method were significantly higher than the values obtained from the patients who underwent operations by conventional exposure. DISCUSSION AND CONCLUSIONS: In both patient groups, the balancing capacities continuously improved over the first 12 weeks of the postoperative period, but the dynamic balancing capacities while standing on both limbs, on the affected limb and on the non-affected limb significantly differed from those of the controls. The balancing capacities of the patients who underwent the minimally invasive exposure procedures improved more rapidly than did the capacities of the patients who underwent operations utilising the conventional exposure method. This reduced balancing capacity should be considered when developing dynamic balancing abilities and abandoning therapeutic aids, and the difference in dynamic balancing abilities between the two patient groups should also be considered.

Variability of gait in the early postoperative period of total knee arthroplasty with different surgical technique.

PURPOSE: The purpose of this study was to work out an objective and sensitive method for the early postoperative period following total knee arthroplasty (TKA) in which analysis of the gait parameters is possible and also to investigate the influence of different surgical approaches for TKA on the gait during stepping in the first three months of the postoperative period. METHODS: Three groups of patients: age-matched healthy elderly patients as a control group, patients operated upon by the conventional technique and finally by the minimally invasive technique combined with computer-assisted navigation. All three groups included ten patients. The motions of knee, shoulder and pelvis were measured by ZEBRIS ultrasound-based system preoperatively plus six and 12 weeks postoperatively. From the joint motion, the variability of cadence, and the variability of knee joint motion and that of pelvis and shoulder girdle was determined. RESULTS: Osteoarthritis (OA) of the knee joint and TKA using both operation techniques significantly influenced the variability of stepping parameters compared to the controls. In the early postoperative period a significant difference was detected between the two groups of the operated patients in all parameters. CONCLUSION: Our data prove that our method seems appropriate to provide objective measurement of the gait in the early postoperative period. The variability of motion of the patient groups approaches that of the healthy control group steadily, but does not reach them.

Ex vivo soft-laser treatment inhibits the synovial expression of vimentin and α-enolase, potential autoantigens in rheumatoid arthritis.

BACKGROUND: Soft-laser therapy has been used to treat rheumatic diseases for decades. The major effects of laser treatment may be dependent not on thermal mechanisms but rather on cellular, photochemical mechanisms. However, the exact cellular and molecular mechanisms of action have not been elucidated. OBJECTIVE: The aim of this study was to investigate the ex vivo effects of low-level laser treatment (with physical parameters similar to those applied previously) on protein expression in the synovial membrane in rheumatoid arthritis (RA). DESIGN: Synovial tissues were laser irradiated, and protein expression was analyzed. METHODS: Synovial membrane samples obtained from 5 people who had RA and were undergoing knee surgery were irradiated with a near-infrared diode laser at a dose of 25 J/cm(2) (a dose used in clinical practice). Untreated synovial membrane samples obtained from the same people served as controls. Synovial protein expression was assessed with 2-dimensional polyacrylamide gel electrophoresis followed by mass spectrometry. RESULTS: The expression of 12 proteins after laser irradiation was different from that in untreated controls. Laser treatment resulted in the decreased expression of α-enolase in 2 samples and of vimentin and precursors of haptoglobin and complement component 3 in 4 samples. The expression of other proteins, including 70-kDa heat shock protein, 96-kDa heat shock protein, lumican, osteoglycin, and ferritin, increased after laser therapy. LIMITATIONS: The relatively small sample size was a limitation of the study. CONCLUSIONS: Laser irradiation (with physical parameters similar to those used previously) resulted in decreases in both α-enolase and vimentin expression in the synovial membrane in RA. Both proteins have been considered to be important autoantigens that are readily citrullinated and drive autoimmunity in RA. Other proteins that are expressed differently also may be implicated in the pathogenesis of RA. Our results raise the possibility that low-level laser treatment of joints affected with RA may be effective, at least in part, by suppressing the expression of autoantigens. Further studies are needed.