Search

Introduction: In Germany most surgical procedures of the ligaments of the knee and correcting osteotomies of the knees are performed within an inpatient setting. The purpose of this study was to analyze the available data to assess epidemiological trends and incidences in inpatient knee joint surgery., Materials and Methods: Approximately 154 million anonymized DRG inpatient records were collected by the German Federal Statistical Office between 2005 and 2013. These data were screened and analyzed for knee joint surgical ligamental procedures and osteotomies., Results: Anterior cruciate ligament reconstruction (ACLR) or repair had a high incidence (46 per 100,000 persons/year). In addition, the most frequent grafts included hamstring tendon (90%) and the patellar tendon (6.3%) autografts (2013). Peak age group for ACLR was 15-20 years (14.5%) for female and 20-25 years (23.6%) for male patients, while there was a second peak in the age group 45-50 years (13.8%) for female patients. Male patients had a higher risk for receiving ACLR (RR 1.96; 95% CI 1.92-2.00) and for receiving valgizing high tibial osteotomy (RR 2.43; 95% CI 2.27-2.61). Females had a higher risk for receiving varizing distal femur osteotomy (RR 1.89; 95% CI 1.58-2.26)., Conclusion: There are growing trends for joint- and activity-preserving procedure in the middle-aged patients. The knowledge of the trends and incidences related to these procedures may help to validate and discuss the results of clinical and register studies.

Introduction: Porcine flexor tendons, bovine extensor tendons, and human (semitendinosus) tendons are frequently used as substitutes for human ACL grafts in biomechanical in vitro studies. This study compares the biomechanical properties and structural differences of these tendons., Materials and Methods: In this biomechanical study, fresh-frozen porcine flexor tendons, bovine extensor tendons, and human semitendinosus tendons were used (n = 36). The tendons were mounted in a uniaxial testing machine (Zwick/Roell) with cryo-clamps, leaving a 60 mm tendon part free between the two clamps. Specimens have been loaded to failure to evaluate the biomechanical parameters stiffness, yield load, and maximum load. A Total Collagen Assay Kit was used to detect differences in the total collagen type I concentration (n = 30). A one-way ANOVA was performed to detect differences in the means. The significance level was set at p < 0.05., Results: There were no significant differences in the stiffness between the groups (bovine 194 ± 43 N/mm, porcine 211 ± 63 N/mm, and human cadaveric 208 ± 58 N/mm). The yield and maximum loads were high (>1000 N) in all groups, but they were significantly increased in both animal specimens (means of 1681-1795 N) compared with human cadaveric specimen (means of 1289-1406 N; p < 0.01). No difference in the collagen type I concentration was detected (N.S.)., Conclusion: Porcine flexor and bovine extensor tendons are eligible substitutes with similar stiffness and high failure loads compared with human cadaveric semitendinosus tendons in in vitro studies.

Introduction: Aim of this study was to investigate the accuracy of a conventional over-the-top-guide (OTG) with a typically short offset to hit the center of the native femoral ACL footprint through the anteromedial portal in comparison to a specific medial-portal-aimer (MPA) with larger offset., Materials and Methods: In 20 matched human cadaveric knees, insertion sites of the ACL were marked in medial arthrotomy. An OTG with an offset of 5.5 mm, respectively, the MPA with 9 mm offset was used in a medial portal approach to locate the center of a single bundle ACL reconstruction tunnel with k-wires. Distances from the footprint center, the OTG drilling and the MPA drilling to the roof of the intercondylar notch and to the deep cartilage margin were determined. After positioning of radiological markers, radiographic analysis was performed according to the quadrant technique as described by Bernard and Hertel., Results: The distance from ACL origin to the roof of the notch was 10.3 (±2.1) mm, in the OTG group 6.7 (±1.5) mm and in the MPA group 9.6 (±1.9) mm. The distance to the deep cartilage margin was 9.5 (±1.7) mm from ACL origin, 4.8 (±1.3) mm with OTG and 8.7 (±1.4) mm with MPA. There were statistically significant differences between the distances of the footprint center and the OTG group after measuring and also after radiographic analysis (p < 0.0001). Using the MPA, no significant different distances in comparison to the anatomical ACL center were found (p > 0.0001). There was an increased risk for femoral blow (9/10 vs. 0/10) in the OTG group after overdrilling with a 9 mm drill., Conclusion: Short (5.5 mm) offset femoral aiming devices fail to locate the native ACL footprint center in medial portal approach with an increased risk for femoral blowout when overdrilling. The special medial-portal-aiming device with 9 mm offset hit the center reliably.