The role of epimysium in suturing skeletal muscle lacerations.
BACKGROUND
Direct muscle trauma is a common and disabling clinical problem. Surgical muscle repair is difficult to evaluate because reliable repair techniques have not been established scientifically. The purpose of this study was to assess the biomechanical properties of epimysium, the collagenous tissue sheath that surrounds muscles in the body.


METHODS
We surgically repaired transected porcine muscle bellies with and without epimysium. For both groups, 25 figure-eight stitches in lacerated quadriceps bellies from a euthanatized pig were loaded under tension on a biomechanical machine (model 8521S, Instron Company). Maximum loads and strains were measured and mechanisms of failure recorded.


RESULTS
The mean load for repairs with epimysium (25.1 N) was significantly higher (p = 0.034) than that for repairs without epimysium (21.2 N). The mean strain for repairs with epimysium (10.4%) was significantly higher (p < 0.001) than that for repairs without epimysium (7.3%). The mechanisms of failure were also different. Among epimysium repairs, 15 stitches avulsed muscle transversely, and 10 stitches tore out longitudinally from the muscle. In the nonepimysium group, 1 suture avulsed muscle and 24 sutures tore out. Muscle was the weakest element in each test.


CONCLUSIONS
These data showed that epimysium incorporation into suturing improves the capacity of repairs to bear force. These findings fill a knowledge gap and may improve outcomes of muscle suturing. By focusing the experiment on biomechanical properties of muscle stitching, this study showed the key role epimysium plays in muscle suturing.
Kragh
John F
JF
Orthopaedic Service, Brooke Army Medical Center, and US Army Institute of Surgical Research, Extremity Trauma Study Branch, 3600 Rawley E. Chambers Avenue, Rm. 292-1, Fort Sam Houston, TX 78234, USA.
Svoboda
Steven J
SJ
Wenke
Joseph C
JC
Brooks
Daniel E
DE
Bice
Terry G
TG
Walters
Thomas J
TJ
D000818:Animals; D005206:Fascia Lata / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D022125:Lacerations / Q000601:surgery*; D018482:Muscle, Skeletal / Q000293:injuries / Q000503:physiopathology* / Q000601:surgery*; D013536:Suture Techniques; D013552:Swine; D013718:Tensile Strength / Q000502:physiology; D017211:Treatment Failure; D016474:Weight-Bearing / Q000502:physiology