Delaying anterior cruciate ligament reconstruction for more than 3 or 6 months results in lower risk of revision surgery.

BACKGROUND: The objective of this study is to investigate the risk of revision surgery when delaying anterior cruciate ligament reconstruction (ACLR) past 3 months or 6 months after injury. MATERIALS AND METHODS: A total of 30,280 patients with isolated ACLR were identified in the Danish Knee Ligament Reconstruction Registry and divided into four groups; ACLR < 3 months, > 3 months, < 6 months, or > 6 months after injury. Primary outcome was revision surgery and secondary outcome were objective and subjective clinical outcome. The 2 year relative risk, crude, and adjusted hazard ratio (HR) were calculated. RESULTS: Comparing ACLR < 3 months to ACLR > 3 months of injury the 2 year relative risk of revision surgery was found to be 1.81 (95% CI 1.46-2.23; P < 0.001) with an adjusted hazard ratio (HR) of 1.27 (95% CI 1.12-1.44; P < 0.001). Comparing ACLR < 6 months to ACLR > 6 months of injury the 2 year relative risk of revision surgery was found to be 1.61 (95% CI 1.34-1.92; P < 0.001) with an adjusted HR of 1.27 (95% CI 1.15-1.40; P < 0.001). CONCLUSION: The risk of revision ACLR surgery was found to be increased when ACLR was performed within 3 months or 6 months of injury compared with later surgery. The 1 year postoperative objective knee laxity and the subjective patient-related outcome was found to be without a clinically significant difference; however, those with early ACLR (< 3 months or < 6 months) were found to have a higher activity level 1 year postoperatively. The information about increased risk of revision when having early surgery should be informed to patients when deciding timing of ACLR treatment. LEVEL OF EVIDENCE: II.

Effect of anterior tibial bowing on measurement of posterior tibial slope on conventional X-rays.

PURPOSE: The posterior tibial slope (PTS) has different biomechanical effects on the knee. Especially in revision ACL reconstruction, a precise analysis is essential. Therefore, we investigate the influence of the anterior tibial bowing angle on the posterior slope measurement. Our hypothesis of the present study is that the short tibial X-rays underestimate the PTS in cases with increased anterior bowing of the tibia. METHODS: The PTS was measured on 162 true longitudinal radiographs of the complete tibia (lateral mechanic axis). The average age of the patients was 35.7 years (range 19-59 years) and the most common diagnosis was failed anterior cruciate ligament reconstruction. Using this X-ray, the slope on the short axis and the slope on the entire axis were measured. In addition, the angle of the anterior bowing was determined. RESULTS: The mean PTS for the lateral mechanic axis of the tibia was 10.6° (± 3.5) in contrast to 11.6° (± 3.5) for the short tibial axis. These two measurements differ significantly. (p < 0.001). The mean anterior tibial bowing angle on the lateral X-rays of the whole tibia was 2.3° (± 2.0). There is a significant positive, relationship between tibial bowing angle and PTS as referenced by the lateral mechanic axis (Spearman's correlation, r = 0.273 and p < 0.001). CONCLUSION: With increasing anterior tibial bowing, the posterior tibial slope on the short knee radiograph is underestimated compared to the slope measurement on the lateral mechanic axis.

Measurement technique for posterior tibial slope on radiographs can affect its relationship to the risk of anterior cruciate ligament rupture.

PURPOSE: The purpose of this study was to determine the most reliable radiographic measurement method to evaluate PTS as a risk factor for ACL reconstruction failure. METHODS: Patients who underwent ACL reconstruction or ACL revision reconstruction between January 2009 and December 2014 by a single surgeon were included. Fifty-two consecutive patients who underwent ACL revision reconstruction were compared to a random selection of 52 patients who underwent primary ACL reconstruction and a control group of 52 patients without ACL injury. ACL reconstruction was performed using either ipsilateral (primary) or contralateral (revision) quadrupled hamstring autograft. Lateral knee radiographs were evaluated using three methods: (1) longitudinal axis, (2) anterior tibial cortex axis, and (3) posterior tibial cortex. RESULTS: A significant difference was found between subjects who underwent ACL reconstruction and control knees (6.79° vs. 5.31°, p = 0.046) using the posterior tibial cortex method. No other statistical significance was found between groups. A multiple linear regression analysis found that the PTS as measured by any method was not affected by the patient's age, sex, height, weight, and BMI. All methods of measurement for PTS demonstrated excellent (ICC > 0.90) intra-rater and inter-rater reliability, but only the posterior tibial cortex method maintained excellent intra-rater and inter-rater reliability (ICC > 0.90) when evaluating patients with ACL revision reconstruction. CONCLUSIONS: The posterior tibial cortex measurement is the most reliable method for analyzing the PTS on lateral knee radiographs in patients undergoing ACL revision reconstruction.

High Tibial Osteotomy and Anterior Cruciate Ligament Reconstruction/Revision.

High tibial osteotomy (HTO) may be performed in association with anterior cruciate ligament (ACL) reconstruction/revision in patients with medial osteoarthritis, varus malalignment, and anterior instability. Furthermore, it may be performed in patients with varus alignment and increased posterior tibial slope (exceeding 12°), because it is related to an increased risk for ACL failure. There are different techniques to perform HTO, and consequently, a concomitant HTO and ACL reconstruction/revision. This article describes the indication, surgical techniques, and outcomes of concomitant HTO and ACL reconstruction/revision.

Healing of tibial bone tunnels after bone grafting for staged revision anterior cruciate ligament surgery: A prospective computed tomography analysis.

AIM: To quantify healing of tibial bone tunnels after bone grafting in two-stage ACL reconstruction revision. METHODS: Ten consecutive patients underwent autogenous bone grafting prior to ACL reconstruction revision (four females and six males, average age 28years). The indications for two-stage surgery were as follows: (1) the enlargement of the tibial tunnel aperture was >20mm in diameter or, (2) the existing tunnel was overlapped with the optimal tunnel and positioned more than a half tunnel diameter posterior to the optimal position. An autogenous iliac bone block was driven into a new tunnel. CT examinations were performed at three, 12 and 24weeks after bone grafting. Evaluations were performed on 15 axial planes at one-millimeter intervals from the articular surface perpendicular to the long axis of the tibia using the following three parameters: occupying ratio (OR), union ratio (UR), and bone mineral density (BMD) of grafted bone. RESULTS: The average ORs were 81, 85 and 94%, and the average URs were 49, 75 and 89% at three, 12 and 24weeks, respectively. Each parameter significantly increased over time. The average BMD was 510 and 571mg/cm(3) at 12 and 24weeks, respectively, with a significantly higher value at 24weeks. CONCLUSION: The average ORs, URs and BMD at 24weeks after bone grafting were higher than those at 12weeks, which suggests that at 24weeks after bone grating, the condition of the patients' beds becomes favorable for safe implantation and fixation of ACL graft revision. LEVEL OF EVIDENCE: Case series Level IV.