Significant Increase in the Rate of Meniscal and Chondral Injuries Between Primary and Revision Anterior Cruciate Ligament Reconstruction. (188)

Objectives: Anterior cruciate ligament (ACL) injuries are often associated with meniscal and chondral lesions. Meniscal lesions are present in up to 50% of ACL injured knees, and chondral lesions occur with an incidence of 20% to 40% in acute ACL-injured knees. The major importance of this lies in the fact that menisectomy and severe chondral damage are important predictors of poor outcomes including the subsequent development of knee osteoarthritis. Furthermore, patient reported outcomes following revision ACL reconstruction remain inferior to primary ACL reconstruction and this may, at least in part, be due to an increased incidence and severity of meniscal and chondral injuries. Although multiple studies have demonstrated that meniscal and chondral lesions are generally present at a higher rate at the time of revision ACL reconstruction when compared to primary ACL reconstruction, large studies following individual patients through primary and revision ACL reconstruction and tracking the change in the occurence of these injuries are scarce. The primary objective of this study was to determine the proportion of patients with meniscal and chondral injuries at the time of primary ACL reconstruction and determine how this rate changed by the time they underwent revision ACL reconstruction. The hypothesis was that the proportion of patients with meniscal and/or chondral lesions would be significantly greater at revision ACL reconstruction when compared to the primary procedures. Methods: Consecutive patients who underwent primary and then revision ACL reconstruction between March 1999 and February 2018 were identified using a single center registry. Patient characteristics, and intraoperative data from each procedure were collected and analyzed. This specifically included the occurrence and type of meniscal and chondral pathology. Descriptive statistics were used to evaluate the study sample using medians, descriptive data analysis was conducted depending on the nature of the criteria. Comparison between variables were assessed with student’s t test for quantitative variables and Mcnemar test for categorical variables. Statistical significance was set a t p<0.05. Results: 213 consecutive patients underwent both primary ACL reconstruction and then revision surgery during the study period. The average time from primary ACLR to Revision was 46.8 ± 36.6 months (range 5-181).The mean age of patients at primary ACLR was 22.21±7.21 years. The mean age of patients at revision ACLR 26.1 ± 8.3 years. The mean IKDC for the entire population was 85.53 ± 11.59, The mean ACL-RSI score was 71.89 ± 23.95. The mean Lysholm score was 91.77±10.24. The proportion of patients with chondral lesions significantly increased from 7% at primary ACL to 15.5% at revision ACL (p < 0.05). Meniscal lesions also significantly increased from 44.6 % at primary ACLR to 70% at revision ACLR (p < 0.05). There was no significant difference in the rate of lateral meniscal lesions (11.7 vs 13.1, p > 0.05). However, the proportion of patients with a medial meniscus lesion (25.4 vs 36.2, p < 0.05) and bimeniscal lesions (7.5 vs 20.7, p < 0.05) increased significantly at revision ACL reconstruction. Conclusions: The proportion of patients with meniscal and//or chondral injuries at the time of revision ACL reconstruction is significantly higher than at the time of primary ACL reconstruction. Specifically, the rate of medial meniscus and bimeniscal injuries is significantly higher in patients undergoing revision ACL reconstruction

Posterior Slope Reducing Osteotomy With Concomitant Anterior Cruciate Ligament Reconstruction

Background: Modern techniques for graft choice, preparation, and fixation for anterior cruciate ligament (ACL) reconstruction demonstrate excellent longevity and return-to-play rates; however, up to 10% to 18% of cases continue to suffer reruptures, with even higher rates in specific subsets of patients. Indications: Normally, the posterior tibial slope is measured between 7° and 10°, with biomechanical and observational studies showing that posterior slope greater than 12° increases the risk of graft failure by 5× by allowing for increased anterior tibial translation, putting increased stress on the graft. The primary indication for a slope correction osteotomy with a revision ACL reconstruction is a patient with tibial slope greater than 12° who has failed prior ACL reconstruction. Technique Description: In our preferred technique, we illustrate a slope reducing anterior closing wedge proximal tibial osteotomy with concurrent revision ACL reconstruction rather than a staged ACL reconstruction. Results: The primary benefit of this technique is the ability to correct the tibial slope and reconstruct the ACL in one setting, which decreases recovery time, costs, and risks to the patients by eliminating an additional procedure. Discussion/Conclusion: In cases of ACL reconstruction failure, particularly in patients with multiple failures, an increased posterior tibial slope may be a contributing factor. Anterior closing wedge osteotomy has been shown to be an effective treatment, in patients with a native slope greater than 12°. A slope reducing anterior closing wedge proximal tibial osteotomy with concurrent revision ACL reconstruction rather than a staged ACL reconstruction has a wide array of benefits.

Stacked Biocomposite Screws in a Single-Stage Revision Anterior Cruciate Ligament Reconstruction Has Acceptable Fixation Strength in a Porcine Cadaveric Model

Background: Stacked screws is a commonly used technique in single-stage revision anterior cruciate ligament (ACL) reconstruction in the setting of bone loss, but there are limited data to support its use. Hypothesis: Two configurations of a biocomposite stacked screws construct have similar fixation strength and linear stiffness as a primary ACL reconstruction construct in a biomechanical model. Study Design: Controlled laboratory study. Methods: A total of 30 porcine legs were divided into 3 groups. Group 1 underwent primary ACL reconstruction with a patellar tendon graft fixed into the femur, with an 8-mm biocomposite interference screw of beta-tricalcium phosphate and poly lactide-co-glycolide. For a revision ACL reconstruction model, groups 2 and 3 had bone tunnels created and subsequently filled with 12-mm biocomposite screws. New bone tunnels were drilled through the filler screw and the surrounding bone, and the patellar bone plug was inserted. Group 2 was fixed with 8-mm biocomposite screws on the side of the graft opposite the filler screw, while group 3 had the interference screw interposed between the graft and the filler screw. The construct was loaded at 1.5 mm/s in line with the tunnel until failure. Load to failure, linear stiffness, and mode of failure were recorded. Results: The mean pullout strength for groups 1, 2, and 3 was 626 ± 145 N, 653 ± 152 N, and 720 ± 125 N, respectively ( P = .328). The mean linear stiffness of the construct in groups 1, 2, and 3 was 71.4 ± 9.9 N/mm, 84.1 ± 11.1 N/mm, and 82.0 ± 10.8 N/mm, respectively. Group 2 was significantly stiffer than group 1 ( P = .037). Conclusion: Two configurations of a biocomposite stacked screws construct for a single-stage revision ACL reconstruction in the setting of bone loss show a similar fixation strength and linear stiffness to a primary ACL reconstruction at time zero in a porcine model. Clinical Relevance: In the setting of bone loss from tunnel malpositioning, a single-stage revision ACL reconstruction using a stacked screws construct may provide adequate fixation strength and linear stiffness.

Lower Failure Rates and Improved Patient Outcome Due to Reconstruction of the MCL and Revision ACL Reconstruction in Chronic Medial Knee Instability

Background: Concomitant lesion of the medial collateral ligament (MCL) is associated with a greater risk of anterior cruciate ligament (ACL) graft failure. Purpose: The aim of this study was to compare two medial stabilization techniques in patients with revision ACL reconstruction (ACLR) and concomitant chronic medial knee instability. Study Design: Cohort study; Level of evidence, 3. Methods: In a retrospective study, we included 53 patients with revision ACLR and chronic grade 2 medial knee instability to compare medial surgical techniques (MCL reconstruction [n = 17] vs repair [n = 36]). Postoperative failure of the revision ACLR (primary aim) was defined as side-to-side difference in Rolimeter testing ≥5 mm or pivot-shift grade ≥2. Clinical parameters and postoperative functional scores (secondary aim) were evaluated with a mean ± SD follow-up of 28.8 ± 9 months (range, 24-69 months). Results: Revision ACLR was performed in 53 patients with additional grade 2 medial instability (men, n = 33; women, n = 20; mean age, 31.3 ± 12 years). Failure occurred in 5.9% (n = 1) in the MCL reconstruction group, whereas 36.1% (n = 13) of patients with MCL repair showed a failed revision ACLR ( P = .02). In the postoperative assessment, the anterior side-to-side difference in Rolimeter testing was significantly reduced (1.5 ± 1.9 mm vs 2.9 ± 2.3 mm; P = .037), and medial knee instability occurred significantly less (18% vs 50%; P = .025) in the MCL reconstruction group than in the MCL repair group. In the logistic regression, patients showed a 9-times elevated risk of failure when an MCL repair was performed ( P = .043). Patient-reported outcomes were increased in the MCL reconstruction group as compared with MCL repair, but only the Lysholm score showed a significant difference (Tegner, 5.6 ± 1.9 vs 5.3 ± 1.6; International Knee Documentation Committee, 80.3 ± 16.6 vs 73.6 ± 16.4; Lysholm, 82.9 ± 13.6 vs 75.1 ± 21.1 [ P = .047]). Conclusion: MCL reconstruction led to lower failure rates in patients with combined revision ACLR and chronic medial instability as compared with MCL repair. MCL reconstruction was superior to MCL repair, as lower postoperative anterior instability, an increased Lysholm score, and less medial instability were present after revision ACLR. MCL repair was associated with a 9-times greater risk of failure.

A high tibial slope, allograft use, and poor patient-reported outcome scores are associated with multiple ACL graft failures

Purpose To compare clinical outcomes, radiographic characteristics, and surgical factors between patients with single and multiple anterior cruciate ligament (ACL) graft failures. It was hypothesized that patients experiencing multiple ACL graft failures exhibit lower patient-reported outcome scores (PROs) and a higher (steeper) posterior tibial slope (PTS) than patients with single ACL graft failure. Methods Patients undergoing revision ACL reconstruction with a minimum follow-up of 12 months were included in this retrospective cohort study. Based on the number of ACL graft failures, patients were assigned either to the group “single ACL graft failure “or” multiple ACL graft failures “. The PTS was measured on strict lateral radiographs. Validated PROs including the International Knee Documentation Committee (IKDC) subjective knee form, Knee Injury and Osteoarthritis Outcome Score, Lysholm Score, Tegner Activity Scale, ACL-Return to Sport after Injury Scale, and Visual Analogue Scale for pain were collected. Results Overall, 102 patients were included with 58 patients assigned to the single ACL graft failure group and 44 patients to the multiple ACL graft failures group. Quadriceps tendon autograft was used significantly more often (55% vs. 11%, p < 0.001) and allografts were used significantly less often (31% vs. 66%, p < 0.001) as the graft for first revision ACL reconstruction in patients with single versus multiple ACL graft failures. Patients with multiple ACL graft failures were associated with statistically significantly worse PROs (IKDC: 61.7 ± 19.3 vs. 77.4 ± 16.8, p < 0.05; Tegner Activity Scale: 4 (range, 0–7) vs. 6 (range 2–10), p < 0.05), higher PTS (12 ± 3° vs. 9 ± 3°, p < 0.001), and higher rates of subsequent surgery (73% vs. 14%, p < 0.001) and complications (45% vs. 17%, p < 0.05) than patients with single ACL graft failure. Conclusion Compared to single ACL graft failure in this study multiple ACL graft failures were associated with worse PROs, higher PTS, and allograft use. During the first revision ACL reconstruction, it is recommended to avoid the use of allografts and to consider slope-reducing osteotomies to avoid multiple ACL graft failures and improve PROs. Level of evidence Level 3.