[The prevalence of radiological osteoarthritis in relation to age, gender, birth-year cohort, and ethnic origins]. / Die Prävalenz der radiologischen Gonarthrose in Bezug zu Lebensalter, Geschlecht, Jahrgangskohorte und ethnischer Zugehörigkeit. Eine Metaanalyse.

AIM: This metaanalysis was performed to evaluate the prevalence of the radiological assessed knee osteoarthritis in the whole community. MATERIALS AND METHODS: Medical databases (Medline, EMBASE, Cochrane) were searched for the strategy: ["Osteoarthritis" and "Knee" and "Prevalence"]. The deadline for the search was 31.12.2009. Two investigators (first and senior author) independently made the selection from 17 studies (from a total of 1428) according to the inclusion criteria: a cross-sectional study of the whole community, radiological investigation and definition of knee ROA by an established radiological score. Only studies in English or German language were evaluated. Effect sizes (event rate, odds ratio [OR] and confidence interval [CI]) were calculated by the software "Comprehensive Metaanalysis V2". Study heterogeneity (I2) was determined accordingly to Higgins. RESULTS: The kappa index for interobserver validity was k = 0.948. All studies judged the grade of osteoarthritis according to the Kellgren-Lawrence (KL) score. For calculation of knee ROA KL grades 2+ were estimated only. The total prevalence of knee ROA was 24.3 % (CI 23.4-25.2 %). The whole prevalence in male patients was 24.3 % (CI 23.4-25.2 %); I2 = 59.4 (p = 0.002) and in female patients 32.6 % (CI 31.8-33.4 %); I2 = 49,1 (p < 0.001). Younger male patients (age 50-) had a prevalence of 5.6 (CI 4.5-6.8). In older patients (80+) the male prevalence was 44.5 % (CI 39.6-49.5 %). In this age group female patients had a prevalence of 71.6 % (CI 67.6-75.3 %). The higher prevalence of knee ROA in female patients was significant (OR = 1.8 [1.7-1.9]; I2 = 46.0 [p < 0.001]). The prevalence of knee ROA was higher in male Asians compared with male Caucasians (OR = 1.1, CI 0.9-1.2; p = 0.080) in tendency. This difference was significant in female patients (OR = 2.2; CI 2.0-2.4; p < 0.001). Furthermore another trend was evaluated. Female patients (70-79 years) from the birth-year cohort 1920- had a prevalence of 37.8 % (CI 35.9-39.7)%. In contrast female patients from the birth-year cohort 1920 had a prevalence of 62.8 % (CI 60.8-64.8 %) at 70-79 years. This difference was significant (OR = 2.8; CI 2.5-3.1; p < 0.001). CONCLUSIONS: This investigation confirms the high prevalence of knee ROA. The evaluated data may serve as a reference for medical or scientific investigations in the future.

[Normal anatomical variants of the superior labrum biceps tendon anchor complex. Anatomical and magnetic resonance findings]. / Anatomische Normvarianten des superioren Labrum- Bizepssehnenanker-Komplexes. Anatomische und kernspintomographische Befunde.

There are difficulties in diagnosing pathologies of the labrum-biceps tendon complex (LBTC) because of the great individual variability of this structure. Anatomical variations, such as the sublabral recess, are frequently found and can also be misinterpreted as Andrews or SLAP II lesions. The etiology and mechanisms of creating such a sublabral recess are not exactly known. The examination of 31 cadaveric shoulder specimens from an age group between 49.3 and 83.6 years showed a sublabral recess in 63.6-85%. This high frequency of sublabral detachment of the labrum in older patients indicates that according to the high range of motion of the humeral head and therefore the changing angle of the long biceps tendon (LBS) a certain mobility of the superior LBTC is physiological and should not necessarily be seen as a sign of instability. Besides mobility-increasing factors such as overhead professions and sports with high repetitive maximal abduction and external rotation and the individual age, the type of insertion of the LBT at the glenoid influences the development of sublabral recess. Accordingly, posterior oriented insertion types of the LBT determine deeper and more posterior oriented sublabral recesses whereas in cases of anterior directed types of insertions no or less deep recesses can be found. Anamnestic aspects, such as the mechanism of injury and overhead activities, these macroscopic and functional associations in MR arthrography and arthroscopic inspection have to be considered in order to differentiate between physiological and traumatic changes of the labrum-biceps tendon complex.

[Biomechanical investigations for the development of a SLAP-II-lesion]. / Pathogenese der SLAP-II-Läsion am Schultergelenk. Biomechanische Untersuchungen.

The superior labral-biceps-tendon-complex forms an anatomical and functional unit and combines static and dynamic elements of shoulder stability. At present, only theoretical hypotheses exist on the etiology of the microtraumatic SLAP-II-lesion. To gain further insight into this, an instrument was developed to simulate throwing motions such as the late-cocking/early acceleration phase as well as deceleration/follow-through. Sixteen freshly frozen shoulder specimens were tested, varying the loads on the biceps tendon (25 N, 50 N, 100 N) and the compression of the humeral head against the glenoid (25 N, 50 N, 80 N). Each shoulder had to run through a certain number of cycles during the particular phase of throwing. The tests were stopped after a SLAP-II-lesion was observed, or after a limit of 15,000 cycles. Every 1,000 cycles the results of the tests were checked arthroscopically. A SLAP-II-lesion developed in only 10% of the specimens during the acceleration/ late cocking phase whereas in the deceleration/ follow-through phase 83% developed such a lesion. According to our results, the deceleration/follow-through of the throwing motion seems to be responsible for creating microtraumatic SLAP-II-lesions. One reason is the loss of the centering function of the long head of the biceps tendon during total internal rotation, another is the increased posterosuperior translation of the humeral head in this position, which leads to a non-physiological contact, creating lesions in this area due to the large sheering forces.