IN VITRO AND IN VIVO DETERMINATION OF ANKLE JOINT AND SUBTALAR JOINT AXES USING THE HELICAL AXIS METHOD

INTRODUCTION: In the kinematic analysis of most human joints continuous motion can be simulated by a sequence of finite motion steps of one part of the joint relative to the other part. In previous studies different experimental setups were used in vitro to determine the subtalar joint axis (talo- alcaneo-navicularaxis), and great variability could be shown for both orientation and position. The orientation of the axis can be described as a projection to anatomical planes in terms of deviation – that is, the projection to the transversal plane and as an inclination that is the projection to the sagittal plane. The study objective was to verify the application of the helical axis method to the ankle and subtalar joint in vitro and to transform the method for in vivo investigations. METHODS: In vitro: one fresh frozen ankle specimen was thawed preexperimentally and then fixed in a laboratory frame. The lower leg was fixed about 15 cm proximal to the ankle joint. In the first series we used stereo photogrammetry to determine optimal marker positions. In a second series with ankle, 2 specimen’s stress x-rays were used to compare talar tilt and the helical axis. In vivo: the marker system was fixed to the tibia using adhesive double- sided tape and with a special shoe construction to fix it to the calcaneus. 3D calculation of marker coordinates in finite positions were performed from a four-camera setup using the Peak Performance® system. Twelve subjects were tested in sitting position without foot-ground contact. They moved their feet from a neutral position into dorsiflexion and (while maintaining dorsiflexion) to eversion and inversion position. RESULTS: The in vitro investigation revealed a mean deviation from repeated measurements of 10.6 degrees (± 4.6) and an inclination of 45.7 (± 5.6). The correlation of x-ray talar tilt with the helical axis method was r = 0.86 for the intact joint and 0.9 with ankle joint ligaments cut. From 12 subjects a mean deviation of 23 (± 13) and an inclination of 46 (± 10) were calculated. The correlation of deviation and inclination was r = 0.8. DISCUSSION: This method is applicable to determine subtalar joint axis in vivo. However, the parameters are highly susceptible to measurement errors and noise. The mean results were in accord with previous studies, but the differences among subjects were remarkable. From the correlation of the angles and the relationship of the axis to the other ankle joint stabilizing structures (muscles, tendons) one could conclude that this complex may play an important role with respect to sudden inversion injuries CONCLUSION:. If the axis of the subtalar joint could be identified as risk factor to ankle sprains then in vivo determination of the axis could be used for prevention

Higher frequency of hamstring injuries in elite track and field athletes who had a previous injury to the ankle - a 17 years observational cohort study

Inversion injury to the ankle and hamstring injuries are common problems in most sports. It is not known whether these injuries constitute a predisposing factor or a precursor of injury or re-injury of these anatomical locations. Therefore, we wished to test the hypothesis that a previous inversion ankle injury exerted a significant effect on the chance of an athlete suffering from a subsequent ipsilateral hamstring injury and vice versa. In an observational cohort study over 17 years (1998-2015), 367 elite track and field athletes, were grouped according to their first traumatic isolated ankle or hamstring injury. Fifty athletes experienced both injuries. The Mann-Whitney U and Chi-square tests (p < 0.05) were performed to test possible associations of ankle and hamstring injury with age, gender, athletics discipline, grade, and type of antecedent injury. Athletes with a preceding ankle injury had a statistically significantly higher chance of experiencing a subsequent hamstring injury compared with athletes who had experienced a hamstring injury as their first traumatic event (x 2 = 4.245, p = 0.039). The proportion of both ankle and hamstring injury events was not statistically different between female (18%) and male (11%) athletes. Age and grade of injury did not influence the proportion of ankle and/or hamstring injury events. There is a statistically significantly higher frequency of hamstring injuries in elite track and field athletes having experienced a previous ankle ligament injury

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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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).</p> <p>Results</p> <p>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.</p> <p>Conclusion</p> <p>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.</p

Successful reconstruction of distal peroneus longus tendon dislocation associated with a split lesion – a case report

Background!#!Peroneal tendon injuries are one of the differential diagnoses in lateral ankle and rearfoot pain. While partial tears are not uncommon, peroneal tendon dislocation at the peroneal tubercle is very rare. Until now, only three papers have been published, presenting five cases of peroneus longus tendon dislocation over the peroneal tubercle. This report adds a previously undescribed case of a peroneus longus tendon split tear that was partially dislocated and entrapped over the peroneal tubercle. The respective operative approach and the outcome are described.!##!Case presentation!#!A 25-year-old international top-level speed skater developed a painful mass over the lateral calcaneal wall. There was no specific inducing injury in his medical history. In contrast to previous reports, according to the patient's history, a snapping phenomenon was not present. Conservative treatment was not effective. By inspection and palpation an enlarged peroneal tubercle was assumed. During operative exploration, we found an incomplete longitudinal split tear of the peroneus longus tendon, which was partially dislocated and entrapped over the peroneal tubercle. This mimicked an enlarged peroneal tubercle. A portion of the split tendon was resected. A deepening procedure of the flat groove of the peroneus longus tendon below the peroneal tubercle and a transosseous reconstruction of the avulsed inferior peroneal retinaculum were performed. After six months, the patient had completely reintegrated into his elite sport and has been free of symptoms since then.!##!Conclusions!#!From the presented case it can be speculated that the inferior peroneal retinaculum was overused, worn out, detached, or ruptured due to overpronation and friction the lateral edge of the low-cut speed skating shoe. Then the peroneus longus tendon experienced substantial friction with the peroneal tubercle with possible dislocation during ankle motion. This frictional contact may have finally led to further degeneration and a longitudinal tear of the tendon. Obviously, dislocations can develop insidiously resulting in lesions of the peroneus longus tendon at the peroneal tubercle, ultimately leading to a tendon entrapment. This mimics an enlarged tubercle. The pathology is very rare and can be successfully addressed surgically