Relationship of common variants in MPP7, TIMP2 and CASP8 genes with the risk of chronic achilles tendinopathy.

Previous etiologic studies have indicated that both environmental and genetic factors play important roles in the occurrence and development of chronic Achilles tendinopathy (AT). A recent study documented the results of the largest genome-wide association study for chronic AT to date, indicating that MPP7, TIMP2 and CASP8 may be involved in the occurrence and development of chronic AT. In this study, we aimed to investigate whether MPP7, TIMP2 and CASP8 were associated with susceptibility to chronic AP in a Han Chinese population. A total of 3,680 study subjects comprised 1,288 chronic AT cases, and 2,392 healthy controls were recruited. Forty-four tag SNPs (7 from CASP8, 20 from MPP7, and 17 from TIMP2) were genotyped in the study. Genetic association analyses were performed at both single marker and haplotype levels. Functional consequences of significant SNPs were examined in the RegulomeDB and GTEx databases. Two SNPs, SNP rs1937810 (OR [95%CI] = 1.20 [1.09-1.32], χ2 = 13.50, P = 0.0002) in MPP7 and rs4789932 (OR [95%CI] = 1.24 [1.12-1.37], χ2 = 17.98, P = 2.23 × 10-5) in TIMP2, were significantly associated with chronic AT. Significant eQTL signals for SNP rs4789932 on TIMP2 were identified in human heart and artery tissues. Our results provide further supportive evidence for the association of the TIMP2 and MPP7 genes with chronic AT, which supports important roles for TIMP2 and MPP7 in the etiology of chronic AT, adding to the current understanding of the susceptibility of chronic AT.

Cross-cultural adaptation of the VISA-P questionnaire for Greek-speaking patients with patellar tendinopathy.

OBJECTIVES: To cross-culturally adapt the VISA-P questionnaire for Greek-speaking patients and evaluate its psychometric properties. BACKGROUND: The VISA-P was developed in the English language to evaluate patients with patellar tendinopathy. The validity and use of self-administered questionnaires in different language and cultural populations require a specific procedure in order to maintain their content validity. METHODS: The VISA-P questionnaire was translated and cross-culturally adapted according to specific guidelines. The validity and reliability were tested in 61 healthy recreational athletes, 64 athletes at risk from different sports, 32 patellar tendinopathy patients and 30 patients with other knee injuries. Participants completed the questionnaire at baseline and after 15-17 days. RESULTS: The questionnaire's face and content validity were judged as good by the expert committee, and the participants. Concurrent validity was almost perfect (ρ=-0.839, p<0.001). Also, factorial validity testing revealed a two-factor solution, which explained 85.6% of the total variance. A one-factor solution explained 80.8% of the variance when the other knee injury group was excluded. Known group validity was demonstrated by significant differences between patients compared with the asymptomatic groups (p<0.001). The VISA-P-GR exhibited very good test-retest reliability (ICC=0.818, p<0.001; 95% CI 0.758 to 0.864) and internal consistency since Cronbach's α analysis ranged from α=0.785 to 0.784 following a 15-17 days interval. CONCLUSIONS: The translated VISA-P-GR is a valid and reliable questionnaire and its psychometric properties are comparable with the original and adapted versions.

Association of type XI collagen genes with chronic Achilles tendinopathy in independent populations from South Africa and Australia.

BACKGROUND: Type XI collagen, which is expressed in developing tendons and is encoded by the COL11A1, COL11A2 and COL2A1 genes, shares structural and functional homology with type V collagen, which plays an important role in collagen fibril assembly. We investigated the association of these three polymorphisms with Achilles tendinopathy (AT) and whether these polymorphisms interact with COL5A1 to modulate the risk of AT. METHODS: 184 participants diagnosed with chronic AT (TEN) and 338 appropriately matched asymptomatic controls (CON) were genotyped for the three polymorphisms. RESULTS: Although there were no independent associations with AT, the TCT pseudohaplotype constructed from rs3753841 (T/C), rs1676486 (C/T) and rs1799907 (T/A) was significantly over-represented (p=0.006) in the TEN (25.9%) compared with the CON (17.1%) group. The TCT(AGGG) pseudohaplotypes constructed using these type XI collagen polymorphisms and the functional COL5A1 rs71746744 (-/AGGG) polymorphism were also significantly over-represented (p<0.001) in the TEN (25.2%) compared with the CON (9.1%) group. DISCUSSION: The genes encoding structural and functionally related type XI (COL11A1 and COL11A2) and type V (COL5A1) collagens interact with one another to collectively modulate the risk for AT. Although there are no immediate clinical applications, the results of this study provide additional evidence that interindividual variations in collagen fibril assembly might be an important molecular mechanism in the aetiology of chronic AT.

The beneficial effects of adding low level laser to ultrasound and exercise in Iranian women with shoulder tendonitis: a randomized clinical trial.

OBJECTIVES: A randomized, double-blind, clinical trial study was conducted with the aim of determining the efficacy of adding laser (830 nm) to ultrasound (US) and exercise for the management of shoulder tendonitis. METHODS: 42 subjects (n=21, in adding laser group and n=21, in US and exercise group) received a course of 10 sessions treatment over one month in the shoulder region. Outcome measures such as Visual Analogue Scale (VAS), Tenderness Severity Scale (TSS), Constant Murley Score (CMS) and Manual Muscle Testing (MMT) were performed before treatment and at the end of 4 weeks treatment. In addition, follow up were performed 2 months after the end of treatment based on the degree of pain improvement. RESULTS: VAS, TSS and CMS improved significantly (P=0.001) in both groups, however the muscle strengths only improved significantly in adding laser group (P< 0.01). CONCLUSION: It seems that both protocols of physical therapy interventions were effective in relieving the signs and symptoms of shoulder tendonitis. Furthermore, adding low level laser therapy (LLLT) to the US and exercise was more efficient in improving the muscle strength in patients with shoulder tendonitis over a period of three months. However, it should be emphasized that, the current results might be due to the effects of laser and exercise instead of laser, us and exercise (as we had no independent group for US).

Cross-cultural adaptation and validation of the VISA-A questionnaire for German-speaking achilles tendinopathy patients.

BACKGROUND: Achilles tendinopathy is the predominant overuse injury in runners. To further investigate this overload injury in transverse and longitudinal studies a valid, responsive and reliable outcome measure is demanded. Most questionnaires have been developed for English-speaking populations. This is also true for the VISA-A score, so far representing the only valid, reliable, and disease specific questionnaire for Achilles tendinopathy. To internationally compare research results, to perform multinational studies or to exclude bias originating from subpopulations speaking different languages within one country an equivalent instrument is demanded in different languages. The aim of this study was therefore to cross-cultural adapt and validate the VISA-A questionnaire for German-speaking Achilles tendinopathy patients. METHODS: According to the "guidelines for the process of cross-cultural adaptation of self-report measures" the VISA-A score was cross-culturally adapted into German (VISA-A-G) using six steps: Translation, synthesis, back translation, expert committee review, pretesting (n = 77), and appraisal of the adaptation process by an advisory committee determining the adequacy of the cross-cultural adaptation. The resulting VISA-A-G was then subjected to an analysis of reliability, validity, and internal consistency in 30 Achilles tendinopathy patients and 79 asymptomatic people. Concurrent validity was tested against a generic tendon grading system (Percy and Conochie) and against a classification system for the effect of pain on athletic performance (Curwin and Stanish). RESULTS: The "advisory committee" determined the VISA-A-G questionnaire as been translated "acceptable". The VISA-A-G questionnaire showed moderate to excellent test-retest reliability (ICC = 0.60 to 0.97). Concurrent validity showed good coherence when correlated with the grading system of Curwin and Stanish (rho = -0.95) and for the Percy and Conochie grade of severity (rho 0.95). Internal consistency (Cronbach's alpha) for the total VISA-A-G scores of the patients was calculated to be 0.737. CONCLUSION: The VISA-A questionnaire was successfully cross-cultural adapted and validated for use in German speaking populations. The psychometric properties of the VISA-A-G questionnaire are similar to those of the original English version. It therefore can be recommended as a sufficiently robust tool for future measuring clinical severity of Achilles tendinopathy in German speaking patients.

Variants within the COL5A1 gene are associated with Achilles tendinopathy in two populations.

OBJECTIVES: A COL5A1 gene variant was shown to be associated with chronic Achilles tendinopathy in a South African population. The aim of this case-control genetic association study was to investigate the BstUI and DpnII restriction fragment length polymorphisms (RFLP) in a second population from Australia and to identify a predisposing haplotype for Achilles tendinopathy in both populations. METHODS: 85 Australian and 93 South African patients with tendinopathy, as well as 210 Australian and 132 white South African control subjects were genotyped for the BstUI (rs12722) and DpnII (rs13946) RFLP, as well as markers rs10858286, rs3196378, rs11103544, rs4504708 and rs3128575. RESULTS: The BstUI RFLP (p<0.001) and marker rs3196378 (p = 0.016) were associated with chronic Achilles tendinopathy in Australian subjects. Individuals within both populations with a CC genotype for the BstUI RFLP had a significantly decreased risk of developing tendinopathy versus any other genotypes (Australian odds ratio 0.42, 95% CI 0.20 to 0.86, p = 0.017). The TC inferred haplotype (rs12722, rs3196378) was found to be overrepresented (global p = 0.008) in the South African tendinopathy group compared with all other haplotypes. CONCLUSION: The BstUI RFLP is associated with chronic Achilles tendinopathy in a second population and a region within the COL5A1 3' untranslated region may predispose individuals to an increased risk of developing chronic Achilles tendinopathy.

Iliotibial band Z-lengthening.

Iliotibial band friction syndrome (ITBFS) is a common overuse injury reported to afflict 1.6% to 12% of runners. It results from an inflammatory response secondary to excessive friction that occurs between the lateral femoral epicondyle and the iliotibial band. Initial treatments include rest, anti-inflammatory medication, modalities (ice or heat), stretching, physical therapy, and possibly a cortisone injection. In recalcitrant cases of ITBFS, surgery has been advocated. This report describes a surgical technique of Z-lengthening of the iliotibial band in patients presenting with lateral knee pain localized to the iliotibial band at the lateral femoral epicondyle and Gerdy's tubercle who failed all nonoperative efforts.