Abstract
Objective:
Anterior cruciate ligament (ACL) deficiency is frequently associated with muscle weakness. It is not clear whether this potential reduction in muscle strength is progressive and related to the duration from the injury to ACL reconstruction. The aim of this study was to evaluate a possible effect of the period from the injury to surgery on pre and postoperative outcomes of isokinetic muscle performance and laxity of knee in patients with anterior ACL deficiency.
Patients and methods:
Clinical and isokinetic assessments of 98 patients with ACL injury were evaluated preoperatively. Patients had appropriate surgical intervention with allograft achilles tendon, autograft quadriceps tendon and auto or allograft bone patellar tendon bone reconstructions. After surgery a standard rehabilitation program, accelerated rehabilitation protocol of Shelbourne, was programmed for patients. The time from the initial injury to surgery was determined and the patients were divided into groups according to the period from the injury to surgical intervention; group 1: surgery within 12 months and group 2: surgery more than 12 months. Group 2 was also subdivided into two groups group 2A: surgery within 12–36 months and group 2B: surgery more than 36 months from the injury. Also the postoperative outcomes of patients were assessed prospectively in the main groups as group 1 and 2. Isokinetic performance and KT- 1000 assessments were evaluated 1 week before and 2, 4, 6, 12 months after ACL reconstruction. All measurements were evaluated both in injured and uninjured legs and healthy legs were considered as controls. These differences between preoperative three groups were analyzed by performing one-way ANOVA and independent samples t test was used to compare the data between postoperative two groups.
Results:
98 patients were included in our study. In arthrometer measurements, no significant difference was determined between groups except in KT 1000 tests between group 1 and group 2B preoperatively (p< 0.05). Also there was no significant difference between groups in flexion isokinetic performance. Preoperatively, in group 1, the difference between healthy and injured leg in extension measurements of peak torque, total work and endurance ratio was significantly lower than both group 2A and group B (p< 0.05). However preoperative analysis of group 2A and group 2B showed that these parameters did not differ significantly when surgery was performed within 12–36 months or more than 36 months from the injury. In the comparisons of groups postoperatively, lower values in these parameters on 2nd month and in endurance on 4th month remained significant after reconstruction in group 1 (p< 0.05). After 6 and 12 months, statistical significance did not remained between groups in spite of some higher deficits in lately operated patients.
Conclusion:
Reconstruction of ACL carried out within 12 months from the injury can minimize the strength deficit in isokinetic evaluations. Satisfactory results in isokinetic muscle performance can be achieved even with late reconstruction with appropriate rehabilitation involving especially quadriceps strengthening exercises.