Biomechanical and viscoelastic properties of different posterior meniscal root fixation techniques.

PURPOSE: The purpose of the present study was to biomechanically compare three different posterior meniscal root repair techniques. Transtibial fixation of a posterior meniscus root tear (PMRT) combined with an anterior cruciate ligament (ACL) reconstruction via one tunnel only shows similar properties in terms of cyclic loading and load to failure compared with direct anchor fixation. METHODS: Twenty-eight porcine knees were randomly assigned to 4 groups (n = 7 each): (1) native posterior meniscal root, (2) suture anchor repair, (3) refixation via a tibial ACL tunnel in combination with an interference screw fixation of the ACL graft, and (4) refixation via a tibial ACL tunnel in combination with an interference screw fixation of the ACL graft with an additional extracortical button fixation. The four groups underwent cyclic loading followed by a load-to-failure testing. Construct elongation during 1000 cycles, dynamic stiffness, attenuation, maximum force during load-to-failure testing, and failure mode were recorded. RESULTS: All reconstructions showed a significant lower maximum load (p < 0.0001) compared with the native meniscal root. The elongation for the transtibial fixation via the ACL tunnel without an additional extracortical backup fixation was significantly higher compared with the suture anchor technique (p < 0.0001). The additional use of a backup fixation led to similar results compared with the anchor repair technique. CONCLUSION: The transtibial refixation of the meniscal root can be combined with an ACL reconstruction using the same tibial bone tunnel. However, an additional extracortical backup fixation is necessary. This might avoid a slippage of suture material and a failure of meniscus root fixation.

Outcome measures in clinical ACL studies: an analysis of highly cited level I trials.

PURPOSE: Clinical research in the area of anterior cruciate ligament (ACL) injury has shown substantial growth during the last decade. This was accompanied by the establishment of a wide range of outcome measures used to address the demands of clinical studies. The aim of this study was to evaluate outcome measures reported by highly cited level I trials in ACL research and identify factors influencing citation metrics. METHODS: The database of the Institute for Scientific Information (ISI) was utilized to screen journals under the subject categories "Orthopaedics", "Sports Sciences", "Radiology" and "General medicine" for the 50 most cited level I ACL trials based on predefined inclusion criteria. Metadata, citation metrics and outcome measures were extracted for each article. Frequencies of reported outcome measures were calculated, and a multiple linear regression model applied to identify factors influencing citation metrics. RESULTS: Two independent outcome measures demonstrated an influence on acquisition of citations including: 1-report of the pivot-shift test and 2-inclusion of the Knee Injury and Osteoarthritis Outcome (KOOS) score. Furthermore, highly cited ACL trials frequently reported KT-1000 measures of anterior translation, range of motion (ROM), graft failure, Lysholm, Tegner and subjective International Knee Documentation (IKDC) scores. CONCLUSION: This analysis reflects on the outcome measures utilized in highly cited level I trials impacting the field of ACL research. It also identifies factors likely to influence acquisition of citations. This is of both clinical and academic relevance when choosing appropriate measures for post-operative outcome evaluation after ACL surgery. LEVEL OF EVIDENCE: I.