Matrix metalloproteinase-1 (MMP-1) and (MMP-8) gene polymorphisms promote increase and remodeling of the collagen III and V in posterior tibial tendinopathy.

Posterior tibial tendinopathy (PTT) can lead to acquired flatfoot in adults. Many patients develop PTT without any identifiable risk factors. Molecular changes in extracellular matrix (ECM) and matrix metalloproteinase (MMP) polymorphism may influence the risk of developing PTT. We aim to investigate the association between matrix metalloproteinase-1 (MMP-1) and (MMP-8) gene polymorphisms with changes in collagen I, III and V in PTT. A case-control study with 22 patients and 5 controls was performed. The MMP-1 (2G/2G) and MMP-8 (T/T) genotypes were determined by PCR-restriction fragment length polymorphism. Tendon specimens were evaluated by a histologic semiquantitative score, immunofluorescence and histomorphometry for collagen I, III and V. Tendon specimens from PTT demonstrated marked distortion of the architecture with necrosis, large basophilic areas with disruption of the normal linear orientation of collagen bundles, infiltration of inflammatory cells, dystrophic calcification and ossification. Under immunofluorescence, PTT tendon specimens showed weak green fluorescence and diffuse distribution of collagen I fibers, but strong fluorescence of collagen III and V. The collagen I fibers were significantly decreased whereas an increase of collagen III and V were found in PTT compared to control groups. In addition, PTT group presented a significant association with MMP-1 and MMP-8 gene polymorphisms. Patients with PTT matrix metalloproteinase-1 (MMP-1) and (MMP-8) gene polymorphisms presented an increase of the collagen III and V ratio, suggesting that the higher proportion in degenerated tendons could contribute to a decrease in the mechanical resistance of the tissue. Still, functional and association studies are needed to elucidate evident roles of MMPs in PTT.

MMP-1 promoter genotype and haplotype association with posterior tibial tendinopathy.

PURPOSE: Posterior tibial tendon (PTT) is particularly vulnerable and its insufficiency is recognized as the main cause of adult acquired flatfoot. Some patients have a predisposition without clinically recognized cause, suggesting that individual characteristics play an important role in tendinopathy. The objective of the present study is to investigate the association of -519 (rs1144393) matrix metalloproteinase-1 (MMP-1) polymorphism and the -1607 (rs1799750) and -519 MMP-1 haplotypes and risk of PTT dysfunction. METHODS: The test group included 50 females who presented PTT dysfunction Grade 2 or 3, and who were submitted to surgical treatment, with histopathological examination of the tendon and magnetic resonance image (MRI) confirming tendinopathy, while the control group was 100 asymptomatic women who present intact PTT at MRI. We analyzed functional polymorphisms MMP-1 and their haplotypes using polymerase chain reaction and restriction fragment length analysis. RESULTS: There was a significant difference in the presence of the different alleles and genotypes between the control group and test group for the MMP-1 gene (p≤0.01). The G allele of the -519 MMP-1 polymorphism increased susceptibility to degeneration in the PTT tendon and seems to be a genetic risk factor. Global haplotype analysis indicated a significant difference between both groups (p<0.0001). Haplotypes G-2G and A-2G had statistically significant risk effect on PTT insufficiency. G-2G, p<0.001; OR=5.72 (CI, 2.84-11.52) and A-2G p=0.002, OR=3.95 (CI, 1.65-9.44). CONCLUSION: According to our results, -519 MMP-1 isolated and -1607/-519 MMP-1 haplotypes are associated to tendinopathy in posterior tibial tendon.

Effectiveness of the dorsal thermoplastic locking orthosis to prevent floating toes in postoperative follow-up of Weil osteotomies: pilot study.

BACKGROUND: The Weil oblique distal metatarsal osteotomy is regularly used in the treatment of primary metatarsalgia. The most frequent complication is the floating toe, which occurs in up to 36% of postoperative follow-up. The theory of reducing the plantar flexor mechanism tension associated with the retraction of the dorsal structures during the healing process of the surgical procedure may explain this negative evolution. OBJECTIVE: This study aimed at assessing the effectiveness of the Tucade dorsal thermoplastic locking orthosis in the prevention of floating toe after Weil osteotomy. METHODS: In all, 30 patients with metatarsalgia diagnosis submitted to Weil osteotomy were treated in the postoperative period with the Tucade dorsal thermoplastic locking orthosis. RESULTS: The floating toe was not observed in this case series. There was 1 case of superficial wound irritation at the dorsal surgical incision and 1 case that evolved with transfer metatarsalgia. Statistical analyses were performed-American Orthopaedic Foot and Ankle Society Scale for lateral toes and extension of the lateral toes-using the t test, and P < .0001 was obtained for comparison of the preoperative and postoperative periods in the population studied. CONCLUSION: The Tucade dorsal thermoplastic locking orthosis during the postoperative period of Weil osteotomy proved to be effective in the prevention of floating toes. LEVEL OF EVIDENCE: Therapeutic Level IV: Case Series.