Strength performance of the pectoralis major muscle after subpectoral breast augmentation surgery

Abstract

Background: Although subpectoral placement of breast implants is a commonly used technique in breast augmentation surgery, the ultimate effects of this procedure on the strength or function of the pectoralis major muscle (PMM) remain undetermined. Objective: In this study, we investigated whether subpectoral placement of mammary implants negatively affects the strength performance (SP) of the PMM. Methods: Twenty women underwent isokinetic testing with the Biodex 3 System (Biodex Medical Systems, Inc, Shirley, NY) before surgery and 2 and 6 weeks after subpectoral placement of breast implants. Nine patients returned for long-term testing. To isolate the PMM, we tested two motions: internal rotation and extension/adduction. The results were evaluated in two ways. We compared postoperative SP to baseline (preoperative) SP using paired Student t tests. P values of less than 0.05 were considered statistically significant. SP was also evaluated with the Biodex 3 System Standards, which consider a postoperative SP of less than 75% of baseline significantly impaired and one more than 75% to be within normal limits. Results: Paired comparisons indicated statistically significant reductions in SP 2 weeks after surgery, followed by increases in SP by 6 weeks. When applying the Biodex 3 System Standards, we found that in both internal rotation and extension/adduction, nearly half of the patients had recovered to 75% of baseline SP 2 weeks after surgery and that more than three- quarters of the patients were fully recovered 6 weeks after surgery. Long-term follow-up in 9 patients revealed retention of SP or further improvement. Conclusions: Subpectoral placement of mammary implants did not produce statistically significant long-term loss of upper-extremity SP. It appears that no permanent loss of strength of the PMM results from subpectoral placement of breast implants.