Doxycycline-mediated inhibition of matrix metalloproteinases improves healing after rotator cuff repair.
Am J Sports Med
; 38(2): 308-17, 2010 Feb.
Article
em En
| MEDLINE
| ID: mdl-19826139
ABSTRACT
BACKGROUND:
Recent studies demonstrate a potentially critical role of matrix metalloproteinases (MMPs) and their inhibitors in the pathophysiology of rotator cuff tears.HYPOTHESIS:
Doxycycline-mediated MMP inhibition after rotator cuff repair will improve tendon-to-bone healing. STUDYDESIGN:
Controlled laboratory study.METHODS:
Rats (n = 183) underwent acute detachment and repair of the supraspinatus tendon and the animals were divided into 4 groups In controls (n = 66), the supraspinatus was repaired to its anatomical footprint. In experimental groups, an identical surgery was performed with doxycycline (130 mg/kg/d) administered orally at (1) preoperative day 1 (n = 66), (2) postoperative day (POD) 5 (n = 28), or (3) POD 14 (n = 23). Animals were sacrificed at 5 days, 8 days, 2 weeks, and 4 weeks. Tendon-bone interface was evaluated with histomorphometry. Enzyme-linked immunosorbent assay for local MMP-13 activity was performed at 8 days and 4 weeks. Biomechanical testing of the healing enthesis was performed at 8 days, 2 weeks, and 4 weeks. Serum doxycycline levels were measured at sacrifice. Statistical analysis was performed using unpaired t tests and 2-way analysis of variance (P < .05).RESULTS:
Serum doxycycline levels were significantly higher in all treated groups compared with controls (1830 +/- 835 vs 3 +/- 3 ng/mL, respectively; P < .001). Doxycycline-treated animals demonstrated greater metachromasia and improved collagen organization at the healing enthesis at POD 5 (P < .06), POD 8 (P < .03), and 2 weeks (P < .04). The MMP-13 activity was significantly reduced in doxycycline-treated compared with control animals at POD 8 (6740 +/- 2770 vs 10400 +/- 2930 relative fluorescent units [RFU], respectively; P < .02) but not at 4 weeks (3600 +/- 3280 vs 4530 +/- 2720 RFU, respectively). The healing enthesis of animals started on doxycycline preoperatively or at POD 5 had an increased load to failure compared to controls at 2 weeks (13.6 +/- 1.8 and 13.2 +/- 1.94 N vs 9.1 +/- 2.5 N, respectively; P < .01). CONCLUSION/CLINICAL RELEVANCE Modulation of MMP-13 activity after rotator cuff repair may offer a novel biological pathway to augment tendon-to-bone healing.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Manguito Rotador
/
Doxiciclina
/
Inibidores de Metaloproteinases de Matriz
/
Antibacterianos
Limite:
Animals
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article