Does the type of surgical approach affect the clinical outcome of total knee arthroplasty?

BACKGROUND: The aim of the study was to investigate the issue of medial midvastus (MMV) vs. medial parapatellar (MPP) approaches in total knee arthroplasty (TKA). It was hypothesized that the two surgical approaches would produce significantly different results with respect to patient-reported knee score outcome (hypothesis 1), short-term postoperative range of motion (ROM) (hypothesis 2), long-term postoperative ROM (hypothesis 3) and prosthesis survival (hypothesis 4). METHODS: A retrospective comparative study design was applied. Data sets were obtained from the state arthroplasty registry. The Western Ontario and McMaster Universities osteoarthritis index (WOMAC) data were analyzed from preoperative and 1 year postoperatively. The ROM data were analyzed for the time points preoperative, postoperative days 4 and 10 and 1 year. RESULTS: Available were 627 cases (407 MMV vs. 220 MPP) and 1 year postoperatively there were no significant differences between groups regarding the WOMAC scores (hypothesis 1). Early postoperatively on days 4 and 10 after TKA there were no differences between groups (p = 0.305 and p = 0.383, respectively, hypothesis 2). Likewise, ROM did not significantly differ between the groups 1 year after TKA (p = 0.338, hypothesis 3). The 5­year prosthesis survival did not differ between the groups and showed 94.46% (95% confidence interval, CI 90.69-96.73%) in the MMV group and 94.33% (95% CI 89.96-96.83%) in the MPP group (p = 0.664, hypothesis 4). CONCLUSION: Both surgical approaches produce equivalent clinical results in terms of early postoperative ROM, late postoperative ROM and 1­year WOMAC. The same prosthesis survival rates can be expected.

Kinematic predictors of wrist shot success in floorball/unihockey from two different feet positions.

The objective of this study was to identify biomechanical predictors for accuracy and speed of the wrist shot in floorball, comparing two different starting feet positions. Ten floorball players performed 2 series of 10 stationary wrist shots, in 2 different positions (feet at a right angle to the end of the stick, oriented towards a target and feet parallel to the end of the stick and to the target). A 12-camera motion capture system, tracking reflective markers on key landmarks, was used to record participant and stick kinematics. Accuracy of the shot was quantified by distance of impact from target centre. Player gaze was approximated from head position. Shot accuracy was significantly better (P = 0.007) when feet were at right angle (0.22 [0.14] m) than when they were parallel (0.27 [0.20] m). Ball speed was no significantly different (P = 0.485) between the right angle position (23.50 [17.52] m · s(-1)) and the parallel position (23.50 [17.95] m · s(-1)). Between self-selected position and imposed position, there was no significant difference. Players looking at the target during shooting had greater accuracy. Regression models suggested that ball speed was mainly influenced, in both positions, by the flexion of the supporting leg (ankle, knee and hip), by the rotation of the hip and of the trunk, especially for the spine angles, and by the rotation and abduction-adduction movements of the wrist of the hand on the top of the stick. The comparison between players showed important differences in these technical skills.