Related Experiment Video
Updated: May 26, 2026
Development of a Rabbit Chronic-Like Rotator Cuff Injury Model for Study of Fibrosis and Muscular Fatty Degeneration
Published on: March 31, 2023
Anabolic steroids reduce muscle damage caused by rotator cuff tendon release in an experimental study in rabbits
C Gerber1, D C Meyer, K M Nuss
1Department of Orthopedics, University of Zürich, Balgrist University Hospital, Forchstrasse 340, Zürich, Switzerland.
Background:
Muscles of the rotator cuff undergo retraction, atrophy, and fatty infiltration after a chronic tear, and a rabbit model has been used to investigate these changes. The purpose of this study was to test the hypothesis that the administration of anabolic steroids can diminish these muscular changes following experimental supraspinatus tendon release in the rabbit.
Methods:
The supraspinatus tendon was released in twenty New Zealand White rabbits. Musculotendinous retraction was monitored over a period of six weeks. The seven animals in group I had no additional intervention, the six animals in group II had local and systemic administration of nandrolone decanoate, and the seven animals in group III had systemic administration of nandrolone decanoate during the six weeks. Two animals (group III) developed a postoperative infection and were excluded from the analysis. At the time that the animals were killed, in vivo muscle performance as well as imaging and histological muscle changes were investigated.
Results:
The mean supraspinatus retraction was higher in group I (1.8 cm; 95% confidence interval: 1.64, 2.02 cm) than in group II (1.5 cm; 95% confidence interval: 1.29, 1.81 cm) or III (1.2 cm; 95% confidence interval: 0.86, 1.54 cm). Histologically, no fatty infiltration was measured in either treated group II (mean, 2.2%; range, 0% to 8%) or III (mean, 1%; range, 0% to 3.4%), but it was measured in the untreated group I (mean, 5.9%; range, 0% to 14.1%; p = 0.031). The radiographic cross-sectional area indicating atrophy and the work of the respective muscle during one standardized contraction with supramaximal stimulation decreased in all groups, but the work of the muscle was ultimately highest in group III.
Conclusions:
To our knowledge, this is the first documentation of partial prevention of important muscle alterations after retraction of the supraspinatus musculotendinous unit caused by tendon disruption. Nandrolone decanoate administration in the phase after tendon release prevented fatty infiltration of the supraspinatus muscle and reduced functional muscle impairment caused by myotendinous retraction in this rabbit rotator cuff model, but two of seven rabbits that received the drug developed infections.
Insights
Anabolic steroids like nandrolone decanoate partially prevented muscle changes, including fatty infiltration and functional impairment, after rotator cuff tendon release in a rabbit model. However, infections were noted in some treated rabbits.
Area of Science:
- Orthopedics
- Regenerative Medicine
- Pharmacology
Background:
- Rotator cuff tears lead to muscle retraction, atrophy, and fatty infiltration.
- A rabbit model is utilized to study these post-injury muscular changes.
- Investigating interventions to mitigate these degenerative processes is crucial.
Purpose of the Study:
- To test if anabolic steroid administration can reduce muscle changes after experimental supraspinatus tendon release in rabbits.
- To evaluate the efficacy of nandrolone decanoate in preventing muscle retraction, atrophy, and fatty infiltration.
- To assess the impact of nandrolone decanoate on muscle performance post-tendon injury.
Main Methods:
- Supraspinatus tendon release was performed on 20 New Zealand White rabbits.
- Rabbits were divided into groups receiving no intervention, local/systemic nandrolone decanoate, or systemic nandrolone decanoate.
- Muscle retraction, in vivo muscle performance, and histological changes were assessed over six weeks.
Main Results:
- Nandrolone decanoate administration reduced supraspinatus muscle retraction compared to the control group.
- Fatty infiltration was significantly lower in rabbits treated with nandrolone decanoate.
- While muscle work decreased in all groups, it was highest in the systemically treated group.
Conclusions:
- Nandrolone decanoate partially prevented muscle alterations, including fatty infiltration, following supraspinatus tendon disruption in a rabbit model.
- The anabolic steroid reduced functional muscle impairment associated with myotendinous retraction.
- Post-tendon release administration of nandrolone decanoate showed promise but was associated with a risk of infection.
