No abstract

It is unknown whether the bone bruise that occurs in connection with acute anterior cruciate ligament (ACL) rupture is causing pain and dysfunction. We followed prospectively 17 patients [10 men, seven women, mean age 28 years (range 23-34)] with acute ACL rupture for 2 months. A magnetic resonance imaging (MRI) scan was performed shortly after the injury, and at 2 weeks, 1 month and 2 months. The patients reported the level of pain every day and filled in a Knee injury and Osteoarthritis Outcome Score sheet in connection with MRI. For every MRI of the knee, volume of bone bruise was calculated, and intensity was visually graded. Our study showed a reduction of the pain to 50% approximately 2 weeks after the injury, at which time the bone bruise was at maximum. There was a significant relationship between pain and the volume and intensity of the bone bruise in the medial tibia condyle, as well as pain and the bone bruise volume of the lateral femoral condyle. Patients with bone bruise of the medial tibia and patients with meniscal lesions had more pain. It is suggested that pain and decreased function after acute ACL injury most likely is related to soft tissue and cartilage injury and not to bone bruise.

One of the problems following an anterior cruciate ligament (ACL) injury is to regain strength. We tested 11 patients (5 men, 6 women), mean age 28.4 years, with unilateral ACL insufficiency, with two braces (Donjoy Legend, and Bledsoe Brace Force 111) versus a placebo brace. The patients were tested on a Biodex Dynamometer at 60 and 180 degls in an isokinetic mode. The experiment was designed as a comparative study in a crossover design with the stable knee as the patient's own control. We found no statistically significant effect of the two braces compared to a placebo brace under the test conditions, and no correlation between knee laxitv 1 and the effect of bracing.One of the problems following an anterior cruciate ligament (ACL) injury is to regain strength. The anterior shear force on the tibia, calculated to approximately 1 xBW(700 N) (l), due to the pull of the quadriceps muscle over the patella during knee extension, is, in persons with a stable knee, mainly neutralised by the ACL. Patients with chronical ACL insufficiency lack this stability, and clinical observations indicate that certain patients in this group have problems with anterior subluxation of the tibia and consequently a reduced or a total lack of ability to train, especially the quadriceps muscle, effectively.One hypothesis is that if anterior subluxation is prevented with a knee brace, patients with ACL insufficiency can train more effectively, especially with regard to the quadriceps muscle.Beynnon et al.(2) placed transducers in intact ACLs in patients under local anaesthesia and found that certain knee braces (among these Donjoy) provided some protective strain-shielding effect at an anterior shear load of 100 N, but none when the anterior shear load was increased. Knee braces did not provide any strain-shielding effect in isometric extension. This concurs with other studies, which demonstrate that when using knee braces there is a decreased anterior displacement if the anterior shear load is 90-100 N (3-6), but no effect if the patients have to exercise under physiological loading conditions (4, 5, 7). n strength in