Risk factors for revision after anterior cruciate ligament reconstruction

The overall aim of this thesis was to investigate risk factors for revision anterior cruciate ligament (ACL) reconstruction with a special attention to surgical technique (graft choice and choice of graft fixation) and patients’ age and sex. Specific aims were to describe the usage of the most common grafts and fixations for ACLR in Norway and Scandinavia respectively. To answer these questions we used register data for patients with isolated ACL tear who had undergone ACL reconstruction (ACLR), with revision as the endpoint. We used data from the Norwegian National Knee Ligament Register (NNKLR) for all papers, and in addition, data from the Swedish and Danish National Knee Ligament Registries for paper III. In study I, 12,643 patients were included to evaluate the revision rate and risk factors for revision ACLR, primarily the influence of graft choice (patellar tendon [BPTB] or hamstring tendon [HT] graft). The patients’ age and sex were included in the overall analysis. The revision rate was higher for HT compared with BPTB grafts at all follow-up times, and the adjusted revision risk were twice as high for HT compared with BPTB. Young age was the strongest predictor for revision of the investigated factors. In study II, we described the usage of fixation implants for 14,034 patients with BPTB and HT in Norway and investigated the revision risk for the most common combinations of fixations for BPTB and HT. We found combinations of fixation implants with a higher risk of revision when using HT, especially when suspensory fixation in the femur was used. In study III, we described the most common fixation methods for HT grafts used in 38,666 patients in Scandinavia, and investigated the influence of fixation method on the risk of revision. We found that similar graft fixation methods influenced the risk of revision as in study II. In conclusion, we found both surgical techniques and patient-specific factors that affect the revision rate and revision-risk after ACLR. Young age was the strongest predictor for further revision surgery. Patients reconstructed with HT had twice the risk of revision compared with BPTB, and certain fixation methods for HT had an increased risk of early and overall revision

Epidemiology of injuries in high-level youth sport in Luxembourg [Abstract]

peer reviewe

Studies on meniscus surgery with focus on preservation and meniscus function

The aim of this thesis was to investigate the effect of surgical preservation and restoration of the meniscus on knee function and outcomes. In Study I, 4497 patients with primary hamstring ACLR were evaluated regarding knee laxity preoperatively and at 6-months follow-up using KT-1000. The primary aim was to evaluate the ATT depending on type of treatment of meniscus injuries in conjunction to primary ACLR. A significant reduction in laxity was found for all patients. Medial meniscus resection resulted in significantly increased laxity compared to isolated ACLR. Medial meniscus repair resulted in laxity comparable to isolated ACLR. In Study II, all ACLRs from the SNKLR were evaluated. The primary aim was to compare KOOS and EQ-5D at 2-year follow-up after isolated ACLR to ACLR with associated meniscus injury treated with either repair or resection in the Swedish National Knee Ligament Register. Meniscus resection resulted in worse outcome, whereas meniscus repair resulted in comparable outcome to isolated ACLR. In Study III, 918 meniscus repairs were analysed. The primary aim was to assess failure within three years. Repair with arrows and medial repairs resulted in significantly more failures than repair with anchors and lateral repairs. Concomitant ACLR resulted in less failure of meniscus repair than isolated meniscus repairs. In Study IV, 316 consecutive meniscus repairs were followed up with radiology, KOOS and Lysholm. The primary aim was to determine the effect of meniscus repair on OA and secondly its effect on subjective knee function. Failed meniscus repair resulted in significantly higher risk for OA and worse patient reported outcome. In Study V, seven cases of meniscus transplantation using the semitendinosus tendon are described. The surgical technique is described in detail. Four patients had completed the 12- month follow-up and report significantly improved outcome in IKDC Global Score, KOOS pain subscale and Lysholm. In conclusion, meniscus repair result in less OA and better subjective knee function than meniscus resection. Medial meniscus repair provides less knee laxity than meniscus resection. Failure after meniscus repair are more common for medial and isolated repairs. In cases of post meniscectomy symptoms, the semitendinosus tendon could possibly function as a meniscus transplant with improved knee function for the patients