• Thomas Schmalz
  • Siegmar Blumentritt
Keywords: biomechanics, gait analysis, knee ligament injuries


INTRODUCTION: The disruption of the anterior cruciate ligament (ACL) is treated by different techniques. Besides augmented repairs or non-surgical treatments, patellar tendon autograft reconstruction is the most important treatment. Different results have been published on the effects of the different treatments on the rehabilitation process (Daniel et al., 1994, Minnich et al., 1997). The purpose of the present study was to evaluate, by means of gait analysis data, the rehabilitation of various groups of patients treated with the different techniques after disruption of the anterior cruciate ligament (ACL). METHODS: One year post-surgically, gait analysis was performed during level walking on 35 patients with a patellar tendon autograft reconstructed knee and on 15 patients with an augmented repair. These groups were compared with a nonsurgically treated group of 18 patients and a group of 30 normal controls. The measurements of the non-surgically treated patients were performed 52 weeks after the occurrence of the rupture. An optoelectronic system for recording the kinematics of gait (Primas, NL) and two force plates concealed under a 12m-walkway for measuring the ground reaction forces (Kistler, CH) were used as technical equipment. For the purpose of evaluation, quantitative parameters were derived from knee joint kinematics, the horizontal ground reaction force and the moment acting on the knee joint (Schmalz et al., 1998). RESULTS: Differences in important gait parameters between the two groups of surgically treated patients and the controls persisted up to 52 weeks after the operation. Deficiencies clearly appeared during knee extension in the midstance phase of the surgically treated patients. Only a minority of these subjects (33%) showed results comparable to the controls. Differences were not found between the groups of patients with patellar tendon autograft reconstructed knees and with augmented repaired knees. However, at the time of investigation, the nonsurgically treated patients showed no deficiencies in gait parameters compared to the controls. CONCLUSIONS: The gait parameters of the non-surgically treated patients are indications that the deficient knee stabilisation function of the ACL is compensated by neuromuscular control. The deficiencies of the surgically treated groups are attributed to biomechanical problems like ligament graft positioning, fixation, or pre-tensioning appearing during the operation. From a therapeutic standpoint, good training with special exercises in midstance are recommended as soon as possible after surgery.