We measured the driver reaction times of 40 patients before total knee replacement (TKR) and 4, 6, 8 and 10 weeks after operation. The ability to perform an emergency stop was assessed as the time taken to achieve a brake pressure of 100 N after a visual stimulus. There were 18 drivers and 11 non-drivers; the latter had longer reaction times. In drivers, the ability to transfer the right foot from accelerator to brake pedal did not recover to preoperative levels for eight weeks after right TKR and was unchanged after left TKR. Patients should be advised that they should not drive for at least eight weeks after right TKR.

No abstract

No abstract

Background: The anatomy of the anterior cruciate ligament (ACL) has become the subject of much debate. There has been extensive study into attachment points of the native ligament, especially regarding the femoral attachment. Some of these studies have suggested that fibers in the ACL are of differing functional importance. Fibers with higher functional importance would be expected to exert larger mechanical stress on the bone. According to Wolff’s law, cortical thickening would be expected in these areas. Purpose: To examine cortical thickening in the region of the ACL footprint (ie, the functional footprint of the ACL). Study Design: Descriptive laboratory study. Methods: Using micro–computed tomography with resolutions ranging from 71 to 91 μm, the cortical thickness of the lateral wall of the intercondylar notch in 17 cadaveric knees was examined, along with surface topography. After image processing, the relationship between the cortical thickening and surface topology was visually compared. Results: A pattern of cortical thickening consistent with the functional footprint of the ACL was found. On average, this area was 3 times thicker than the surrounding bone and significantly thicker than the remaining lateral wall ( P < .0001). This thickening was roughly elliptical in shape (with a mean centroid at 23.5 h:31 t on a Bernard and Hertel grid) and had areas higher on the wall where greater thickness was present. The relationship to previously reported osseous landmarks was variable, although the patterns were broadly consistent with those reported in previous studies describing direct and indirect fibers of the ACL. Conclusion: The findings of this study are consistent with those of recent studies describing fibers in the ACL of differing functional importance. The area in which the thickening was found has been defined and is likely to represent the functional footprint of the ACL. Clinical Relevance: This information is of value to surgeons when determining the optimal place to position the femoral attachment site of the reconstructed ACL.

No abstract