Anabolic steroids after total knee arthroplasty. A double blinded prospective pilot study

BACKGROUND Total knee arthroplasty is reported to improve the patient's quality of life and mobility. However loss of mobility and pain prior to surgery often results in disuse atrophy of muscle. As a consequence the baseline functional state prior to surgery may result in poorer outcome "post surgery" and extended rehabilitation may be required. The use of anabolic steroids for performance enhancement and to influence muscle mass is well established. The positive effects of such treatment on bone and muscle could therefore be beneficial in the rehabilitation of elderly patients. The purpose of this study was to investigate the effects of small doses of Nandrolone decanoate on recovery and muscle strength after total knee replacement and to establish the safety of this drug in multimorbid patients. METHODS This study was designed as a prospective double blind randomized investigation. Five patients (treatment group) with a mean age of 66.2 (58-72), average BMI of 30.76 (24.3-35.3) received 50 mg nandrolone decanoate intramuscular bi-weekly for 6 months. The control group (five patients; mean age 65.2, range 59-72; average BMI 31.7, range 21.2-35.2) was injected with saline solution. "Pre-operatively" and "post-operatively" (6 weeks, 3,6,9 and 12 months) all patients were assessed using the knee society score (KSS), isokinetic strength testing and functional tests (a sit-to-stand and timed walking tests). In addition, a bone density scan was used preoperatively and 6 month postoperatively to assess bone mineral density. RESULTS Whilst the steroid group generally performed better than the placebo group for all of the functional tests, ANOVA failed to reveal any significant differences. The steroid group demonstrated higher levels of quadriceps muscle strength across the postoperative period which reached significance at 3 (p = 0.02), 6 (p = 0.01), and 12 months (p = 0.02). There was a significant difference for the KSS at 6 weeks (p = 0.02), 6 (p = 0.02) and 12 month (p = 0.01). The steroid group demonstrated a reduction in the amount of bone mineral density at both the femur and lumbar spine from "pre-" to "post-surgery", however, these results did not reach significance (p < 0.05) using one-way ANOVA. CONCLUSIONS This project strongly suggests that the use of anabolic steroids result in an improved outcome as assessed by the KSS and significantly increases extensor strength. No side effects were seen in either the study or control group. TRIAL REGISTRATION NUMBER Regional Health District: Register No. 03.05Human Research Ethics Committee University: Clearance Number: 04/03-19.