Expression of matrix metalloproteinases 1, 3, and 9 in degenerated long head biceps tendon in the presence of rotator cuff tears: an immunohistological study.
BACKGROUND
Long head biceps (LHB) degeneration, in combination with rotator cuff tears, can be a source of chronic shoulder pain. LHB tenotomy reduces pain and improves joint function although the pathophysiological context is not well understood. Tendon integrity depends on the extracellular matrix (ECM), which is regulated by matrix metalloproteinases (MMP). It is unclear which of these enzymes contribute to LHB but we chose to study MMP 1, 3, and 9 and hypothesized that one or more of them may be altered in LHB, whether diagnosed preoperatively or intraoperatively. We compared expression of these MMPs in both LHB and healthy tendon samples.


METHODS
LHB samples of 116 patients with degenerative rotator cuff tears were harvested during arthroscopic tenotomy. Patients were assigned to 4 groups (partial thickness tear, full thickness tear, cuff arthropathy, or control) based upon intraoperative findings. Partial and full thickness tears were graded according to Ellman and Bateman's classifications, respectively. MMP expression was determined by immunohistochemistry.


RESULTS
MMP 1 and 9 expression was significantly higher in the presence of rotator cuff tears than in controls whereas MMP 3 expression was significantly decreased. MMP 1 and 9 expression was significantly higher in articular-sided than bursal-sided partial thickness tears. No significant association was found between MMP 1 and 9 expression and full thickness tears, and the extent of the cuff tear by Bateman's classification.


CONCLUSIONS
Increased MMP 1 and 9 expression, and decreased MMP 3 expression are found in LHB degeneration. There is a significant association between the size and location of a rotator cuff tear and MMP expression.
Department of Orthopedics and Rheumatology, University Hospital Marburg, Marburg, Germany. lakemeie@med.uni-marburg.de
Stefan
S
Lakemeier
Soeren A
SA
Schwuchow
Christian D
CD
Peterlein
Christian
C
Foelsch
Susanne
S
Fuchs-Winkelmann
Eleni
E
Archontidou-Aprin
Juergen R J
JR
Paletta
Markus D
MD
Schofer
D000368:Aged; D000369:Aged, 80 and over; D001182:Arthroscopy; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000601:surgery; D009140:Musculoskeletal Diseases; D017006:Rotator Cuff / Q000601:surgery; D000070636:Rotator Cuff Injuries; D013710:Tendons / Q000378:metabolism* / Q000601:surgery; D058971:Tenotomy
D019278:Matrix Metalloproteinase 3; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1