Anabolic steroids reduce muscle damage caused by rotator cuff tendon release in an experimental study in rabbits

Gerber C, Meyer DC, Nuss KM, Farshad M. J Bone Joint Surg Am. 2011 Dec 7;93(23):2189-95.

Chronic rotator cuff tendon tears cause structural and physiological maladaptations to the muscle (e.g., muscle atrophy and fatty degeneration) and are often irreversible.  Anabolic steroids, although illegal in the United States, have been shown to enhance synthesis of muscle proteins, induce muscle hypertrophy, and improve contractile strength.  However, their effect on treating the degeneration of rotator cuff muscle in shoulders with chronic rotator cuff tears has not been examined.  Therefore Gerber et al. examined if anabolic steroids would lessen the muscular maladaptations caused by chronic rotator cuff tears.  Twenty New Zealand White rabbits underwent a unilateral release of the supraspinatus tendon and bone insertion site.  To measure work of the muscle during the surgical release the cut bone/tendon unit was attached to a force sensor and pretensioned to 10N and stimulated at 20mA and 40Hz for 0.3 seconds to create a supramaximal contraction.  In addition, samples from the distal third of the muscle were harvested for histology.  The incision was then sutured and the bone/tendon unit was allowed to fully retract for 6 weeks.  During this time seven rabbits did not receive any intervention (control), six received weekly injections of nandrolone decanoate (a common anabolic steroid) in the supraspinatus muscle (local injection) and quadriceps muscle (systemic injection), and seven rabbits received a weekly systemic injection only (quadriceps muscle).  Supramaximal stimulation (to assess work); histology; and computed tomographic (CT) measures of retraction, atrophy, and fatty degeneration were evaluated before and after (6 weeks) detachment.  Muscle tissue was sectioned and stained to assess for fat, muscle, and fibrosis.  The amount of retraction was significantly more in the control group compared to both intervention groups.  There was a significant increase in fatty degeneration in the control group with very little change in both intervention groups.  The amount of work the muscle produced decreased in all of the groups but decreased less (not significant) in the systemic injection group.  There was a significant decrease in cross-sectional area among the control group compared to the systemic injection group.  On histology, the amount of fibrotic tissue was similar to baseline in the group receiving local and systemic injections but significantly higher in both the control and systemic injection group.

First, the authors wanted to point out that they do not recommend this treatment be performed on humans without further research.  However, the results provide evidence to support the possible use of anabolic steroids to help prevent the maladaptations that occur to the rotator cuff muscle following a chronic detachment.  Standard repair of the tendon or traditional rehabilitation has yet to reverse these maladaptations in the rotator cuff muscle.  The successful repair and return of function of chronically torn rotator cuff tendons relies in part on the condition of the muscle.  Muscle atrophy, fatty degeneration, and fibrosis are consistent findings in chronically torn tendons and currently do not improve after repair.  The current study indicates that the use of anabolic steroids, in a rabbit model, may prevent these deleterious effects from occurring.  The authors stated that two of the rabbits in the intervention groups developed infections.  This raises the question of the risk versus reward for the use of anabolic steroids in chronically torn rotator cuff tears.  There are many concerns that need to be tested clinically including long-term physiological side effects to other body systems.  Do you have any rehab strategies to combat deleterious muscle degradation on chronic rotator cuff tears?  Are there other pharmacological medicines that may have similar effects as anabolic steroids without the potential side effects? 

Written by: Stephen Thomas
Reviewed by: Jeffrey Driban

Related Posts:

Gerber C, Meyer DC, Nuss KM, & Farshad M (2011). Anabolic steroids reduce muscle damage caused by rotator cuff tendon release in an experimental study in rabbits. The Journal of Bone and Joint Surgery. American volume, 93 (23), 2189-95 PMID: 22159854