The injured anterior cruciate ligament and neuromuscular rehabilitation

Two prospective, short-term and long-term consecutive randomized studies on non-surgical treated patients with an ACL injury were performed. None of the patients were athletes on a professional level. Outcome measures : isometric muscle strength and isokinetic musclefunction, one-leg hop test, single limb balance, Lysholm knee score and Tegner activity level. In study number one 26 patients with non-acute ACL injuries, with a late diagnosis of symptomatic anterior cruciate ligament lesion, were examined and randomized to open-chain or closed-chain training for a 3 month period. Short term effect after training: Knee extensors improved significantly in both groups, with significantly higher value in isometric extension in open-chain training group,the remaining values with minor differences only. At 3 months standing balance was normalized on the uninjured, but not on the injured side, despite restoration of thigh muscle strength. At 12 months, standing balance was normalized in both legs and persisted at 36 month follow-up. Lysholm knee-score increased significantly during initial 3 months. After 36 months the score was excellent (>83) in 21 out of the 22 remaining patients. Isometric muscle strength values persisted at 36 months. Recreational sports were resumed after training by most patients. 100 patients with acute ACL injury revealed associate lesions in 82% of the cases. Need of supervision in training or not was evaluated, the patients were randomized to supervised or self-monitored training. A transferral of 50% of the SM patients to SV was indicated after 6 weeks, the majority were women. At 36 months isometric muscle strengths and isokinetic work capacity were significantly higher in male patients of original SV group, than in men remaining in the SM group.In transferred male patients recovery was seen with delay in time. In females no differences were observed between groups. Further studies on muscle function after ACL injuries in female patients are required. 85 patients completed the follow-up after 36 months. As part of a joint-protection strategy, restriction of hyperextension was preserved in the majority of cases during the period of follow-up and giving-way events occurred in 5-10% only of the patients during the follow-up

Proprioceptive defects after an anterior cruciate ligament rupture -- the relation to associated anatomical lesions and subjective knee function

A disturbed proprioception has been described in patients with an anterior cruciate ligament (ACL) deficient knee. The relation to demographic data and to different commonly associated anatomical lesions, as well as to subjective knee function, was prospectively studied in 16 consecutive patients after an acute knee ligament injury. All patients had a complete rupture of the ACL, but variable associated anatomical lesions. The threshold to detect a passive motion, as a measure of their proprioceptive ability, was registered repeatedly during the first year after injury. Four of the patients had consistently severe and persistent deficits at 1, 2 and 8 months. These four individuals had more chondral lesions and a lower subjective rating of their knee function than the remaining patients. In the whole group there were significant correlations between the recorded thresholds and associated chondral lesions, meniscal lesions and the subjective rating of knee function. We found no significant relation between age, gender, activity level, grade of mechanical laxity increase or a medial collateral ligament rupture, and the proprioceptive recordings. Thus, morphological lesions other than a rupture of the ACL seem to contribute to the proprioceptive deficits after a knee ligament injury, and the patients' ability to detect a passive motion showed a relation to subjective knee function from the time of injury onwards

Evaluation of an external device measuring knee joint rotation: an in vivo study with simultaneous Roentgen stereometric analysis.

An external device ("rottometer") specially designed to measure knee joint rotation was developed and evaluated with respect to its validity. Simultaneous measurements were made with the rottometer and Roentgen stereometric analysis (RSA) in five patients with implanted tantalum markers in the tibia and femur. Measurements of internal and external rotation were made at 90 degrees and 60 degrees of knee flexion using 3, 6 and 9 N m torques. The coefficients of determination (r2) between the results obtained with the rottometer and RSA were around 0.9 for the total rotation. The rottometer consistently overestimated the rotation by about 100% and this systematic error was most constant at 90 degrees flexion for the different torques. The magnitude of this error from soft tissue deformation as well as the rotatory movements in the hip, foot and ankle joints must be considered when using external devices to measure knee rotation in clinical studies. The most accurate registrations were found in 90 degrees flexion with 9 N m force (r2 = 0.94)