Factors influencing the success of anterior cruciate ligament repair with dynamic intraligamentary stabilisation.

PURPOSE: Primary repair of the anterior cruciate ligament (ACL) has regained interest of clinicians with recent development of novel repair techniques. Dynamic intraligamentary stabilisation was introduced in an attempt to promote healing by shielding cyclic loads acting upon the ACL during the healing phase. The aim of this study was to identify negative factors likely to influence success of this procedure. METHODS: Between 2009 and 2014, 264 patients with an acute ACL rupture undergoing dynamic intraligamentary stabilisation were included in this study. Patients were evaluated for anterior/posterior laxity; range of motion and patient reported outcome measures. Adverse events and re-operations were noted. Failure was defined as AP Translation >3 mm, re-rupture or conversion to ACL reconstruction. Minimum follow-up was 24 months. Univariate and multivariate regression models were utilized to determine predictors of failure. RESULTS: An overall complication rate of 15.1% was noted comprising 9.5% (n = 25) re-ruptures, 4.1% (n = 11) persistent instability, and 1.5% (n = 4) > 10° fixed flexion deformity. Two factors were identified as negative predictors of failure: (1) pursuit of competitive sport activities with a Tegner pre-injury score >7 (Odds Ratio (OR) 4.4, CI 1.2-15.9, p = 0.02) and (2) mid-substance ACL rupture location (OR 2.5, 1.1-5.7, p = 0.02). When neither of those risk factors occurred the failure rate was limited to 3.9%. CONCLUSIONS: Correct patient selection and narrowing of indications are necessary to maintain high success rates of the procedure. Mid-substance ACL ruptures and a high pre-injury sports activity level are two predictors of inferior outcome. LEVEL OF EVIDENCE: II.

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.

Periprosthetic Infection: Major Cause of Early Failure of Primary and Revision Total Knee Arthroplasty.

Revision total knee arthroplasty (RTKA) represents an effective treatment for failed TKA, but with less favorable outcomes. Considering the technical complexity and economic burden of RTKA procedures, it is mandatory to investigate current mechanisms and predictors for RTKA failure. The objective of this study is to evaluate the survivorship and determine the predominant causes of failure of RTKA. A total of 146 patients undergoing RTKA between 2003 and 2013 were identified from the institutional database. Revision was defined as surgery in which the whole prostheses (inlay and both femoral and tibial components) required exchange. Median follow-up was 6.3 ± 2.7 years (range: 2.2-10). Patient demographics, year of primary implantation, reasons for revision surgery, implant type, pain, knee mobility, systemic or local postoperative complications, and treatment of the complications were recorded and evaluated. Infection was a major cause of failure followed by aseptic loosening, instability, pain, malalignment, and inlay wear. Following RTKA, Knee Society Score (KSS) (knee score and functional score) demonstrated a significant improvement (p < 0.05). No significant difference in flexion, extension deficit, and KSS was detected between aseptic and septic primary TKAs preoperatively and following first RTKA. Reinfection rate of the septic primary TKAs was 5%. Infection was the major cause of a second revision, reaching as high as 50% in all cases. The results of this study support that septic failure of a primary TKA is likely to occur within the first 2 years following implantation. Septic failure of primary TKA does not influence survival of the revision prosthesis.

Biologic response of human anterior cruciate ligamentocytes on collagen-patches to platelet-rich plasma formulations with and without leucocytes.

Due to the poor self-healing capacities of the anterior cruciate ligament, previous primary repair attempts have failed. To enhance biologic healing, platelet rich plasma and collagen scaffold have shown promise in animal models. Platelet rich plasma (PRP) is already used in several clinical applications although outcomes are quite debated. The purpose of this study was to examine the effects of different PRP formulations during 21 days: With leucocytes and pure PRP on human anterior cruciate ligament-derived ligamentocytes grown on collagen patches in 3D cell cultures in vitro. Three experimental groups were formed: 2.5% leucocyte rich PRP, 2.5% pure PRP, 20% leucocyte rich PRP, a negative control, and a positive control. Cell proliferation, cell phenotype on mRNA transcript level, and extracellular matrix production (total collagen and glycosaminoglycan content) were evaluated. DNA content and metabolic cell activity increased significantly in all groups on day 21 compared to day 7, except in the negative control. No changes in extracellular matrix production were detected. Different catabolic genes were induced depending on the concentration of leucocyte rich PRP. PRP with and without leucocytes treated anterior cruciate ligamentocytes significantly increased cell proliferation but not extracellular matrix production. However, the specific activation of different catabolic genes was dependent on the relative content of leucocytes. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2733-2739, 2017.