Biceps tendon properties worsen initially but improve over time following rotator cuff tears in a rat model.
Damage to the biceps tendon is often seen in conjunction with rotator cuff tears. However, controversy exists regarding its role in the shoulder and its optimal treatment. A previous study determined that biceps tendons were detrimentally affected in the presence of rotator cuff tears in the rat model and this damage worsened over time. However, whether this damage progresses at later time points to provide a chronic model is unknown. The objective of this study was to determine the changes in the biceps tendon in the presence of a cuff tear over time. Our hypothesis was that histological, compositional, organizational, and mechanical properties would worsen with time. We detached the supraspinatus and infraspinatus tendons of 48 rats and evaluated these properties at 1, 4, 8, and 16 weeks postdetachment. Properties worsened through 8 weeks, but improved between 8 and 16 weeks. We therefore conclude that biceps tendon changes in this model are not truly chronic. Additionally, it has been shown that infraspinatus properties in this model return to normal by 16 weeks, when biceps properties improve, indicating that earlier repair of one or more of the rotator cuff tendons may lead to resolved pathology of the long head of the biceps tendon.
McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104, USA.
Cathryn D
CD
Peltz
Jason E
JE
Hsu
Miltiadis H
MH
Zgonis
Nicholas A
NA
Trasolini
David L
DL
Glaser
Louis J
LJ
Soslowsky
D000818:Animals; D001696:Biomechanical Phenomena; D023421:Models, Animal; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000070636:Rotator Cuff Injuries; D013708:Tendon Injuries / Q000473:pathology / Q000503:physiopathology*; D013997:Time Factors
J Shoulder Elbow Surg. 2009 Mar-Apr;18(2):296-304
19218053
J Bone Joint Surg Br. 2000 Apr;82(3):416-9
10813181
J Shoulder Elbow Surg. 2009 Jan-Feb;18(1):52-7
19095175
J Anat. 1995 Apr;186 ( Pt 2):429-34
7649844
J Shoulder Elbow Surg. 2005 Jan-Feb;14(1 Suppl S):72S-78S
15726090
Clin Orthop Relat Res. 2010 Jun;468(6):1485-92
20049569
J Orthop Res. 1996 Jul;14(4):518-25
8764859
Clin Orthop Relat Res. 1991 Jun;(267):45-56
2044292
J Shoulder Elbow Surg. 2007 Sep-Oct;16(5 Suppl):S198-203
17903711
J Trauma. 2005 Jun;58(6):1189-93
15995469
J Biomech. 2004 May;37(5):739-49
15047003
J Shoulder Elbow Surg. 2000 Sep-Oct;9(5):382-5
11075320
Clin Orthop Relat Res. 1997 Mar;(336):122-9
9060495
J Orthop Res. 2009 Oct;27(10):1379-85
19340876
Ann Anat. 1994 Jan;176(1):75-80
8304595
J Orthop Res. 2009 Mar;27(3):416-20
18924143