One of the most common problems facing patients recovering from anterior cruciate ligament (ACL) repair is loss of muscle strength in the quadriceps. This loss occurs because of quadricep inhibition, which then leads to muscle atrophy. Many attempts have been made to reduce this loss of strength, but most have shown only limited success. Some studies have shown that creatine supplementation improves muscle force and output during resistive exercise in healthy persons. Another study demonstrated that creatine increased power and work capacity in short-term, nontraining studies. These studies show that creatine supplementation augments training-induced strength gains. Tyler and associates evaluated the effect of creatine supplementation on the recovery of muscle strength after ACL reconstructive surgery.

The double-blind, prospective, randomized clinical trial involved patients who had undergone ACL reconstructive surgery. Before surgery, the patients had a battery of tests, including a knee outcome score; height, weight, and body fat analysis; knee range of motion; and knee and hip strength testing. These tests were repeated at weeks 6, 12, and 24. At six months, a single leg hop for distance was added to the battery of tests. Patients were assigned randomly to receive placebo or creatine in a dosage of 20 g per day for one week and then reduce their dosage to 5 g per day for 12 weeks after surgery. Compliance was monitored by providing patients with five tablets more than they would actually need between the various assessment times.

Of 60 patients who participated in the study, 51 were available for evaluation six weeks after surgery. The strength of the involved side increased significantly from six to 12 weeks with regard to knee extension, knee flexion, hip flexion, hip abduction, and hip adduction. These improvements were not significantly different in the creatine group when compared with the placebo group. The single leg hop distance and knee outcome scores were similar in the creatine and placebo groups at 24 weeks.

The authors conclude that creatine supplementation does not provide any benefit in the rehabilitation of patients who have undergone ACL reconstruction. They add that creatine use did not affect muscle strength, power changes, or outcome measures.