Lateral meniscal posterior root tears experience acceptable healing status after transtibial repair technique.

PURPOSE: To evaluate patient MRI results, demography and clinical outcome following transtibial repair of lateral and medial meniscal posterior root tears. METHODS: Patients treated with transtibial repairs of posterior meniscal root tears from 2015 through 2018 performed pre- and postoperative MRI scans. Outcome measures were continuity/discontinuity of the meniscal root and change in meniscal extrusion on MRI. Other outcomes were KOOS, Lysholm score, Tegner activity scale and the Global Rate of Change (GRoC) score for function and pain at follow-up. STUDY DESIGN: Retrospective case-series. RESULTS: Of 41 patients, 36 attended follow-up at mean 26 (12-38) months postoperatively. At follow-up, 11 out of 18 lateral meniscus posterior root tear (LMPRT) versus 5 out of 18 medial meniscus posterior root tear (MMPRT) repairs were classified as healed. Meniscal extrusion decreased in LMPRTs from of 2.3 ± 1.5 mm to 1.4 ± 1.09 mm (p = 0.080) and increased in MMPRTs from 3.1 ± 1.6 mm to 4.8 ± 1.9 mm (p = 0.005) at FU (between-group difference, p < 0.001). LMPRT repairs were associated with ACL injury and additional meniscal injury and were younger and with lower BMI. No between-group differences were found for KOOS, Lysholm or GRoC Function scores. Tegner scale was higher and GRoC Pain score lower in the LMPRT group compared to the MMPRTs. CONCLUSION: Following transtibial repair for meniscal posterior root repairs, the LMPRTs had a higher frequency of healing, whereas most MMPRTs continued to extrude, despite surgical intervention. The study confirmed that LMPRTs and MMPRTs differ in demography and associated injuries.

Complex Tears, Extrusion, and Larger Excision Are Prognostic Factors for Worse Outcomes 1 and 2 Years After Arthroscopic Partial Meniscectomy for Degenerative Meniscal Tears: A Secondary Explorative Study of the Surgically Treated Group From the Odense-Oslo Meniscectomy Versus Exercise (OMEX) Trial.

BACKGROUND: Few studies have examined morphological findings from preoperative magnetic resonance imaging (MRI) and arthroscopic findings as prognostic factors for outcomes 1 and 2 years after arthroscopic partial meniscectomy (APM). PURPOSE/HYPOTHESIS: The purpose was to evaluate prognostic factors of preoperative findings from MRI and arthroscopic evaluation on lower extremity performance at 1 year and patient-reported outcomes at 1 to 2 years after APM. The hypothesis was that medial compartment abnormalities would be prognostic for 1- and 2-year functional outcomes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: This secondary analysis from the OMEX (Odense-Oslo Meniscectomy Versus Exercise) trial included 40 patients treated surgically. Regression analyses with adjustments for age, sex, and body mass index explored associations between MRI findings (tear complexity and extrusion), arthroscopic findings (tear length, cartilage injury, and amount of excised meniscal tissue), and the following: lower extremity performance tests and thigh muscle strength at 1 year and the 5 Knee injury and Osteoarthritis Outcome Score (KOOS) subscales at 1 and 2 years. RESULTS: A complex meniscal tear was a significant and clinically relevant prognostic factor for worse KOOS Symptoms subscores at 2 years (mean, 14.1 points [95% CI, 6.1-22.2]). Meniscal extrusion of at least 11%, 25%, and 20% were significant and clinically relevant prognostic factors for worse KOOS Activities of Daily Living (ADL) subscores at 1 year and worse KOOS Sports and Recreation (Sports/Rec) subscores at 1 and 2 years, respectively. Tear lengths of at least 7.0 mm, 6.7 mm, and 6.5 mm were significant and clinically relevant prognostic factors for better KOOS Symptoms subscores at 1 year and better KOOS Sports/Rec subscores at 1 and 2 years, respectively. A cartilage injury in the medial compartment was a significant and clinically relevant prognostic factor for worse KOOS ADL and Quality of Life (QoL) subscores at 2 years (mean, 10.4 and 19.4 points, respectively [95% CI, 3.4-17.4 and 7.7-31.1, respectively]). More than 20% meniscal tissue excised was a significant and clinically relevant prognostic factor for worse KOOS Pain, Symptoms, ADL, and Sports/Rec subscores at 1 and 2 years (mean, 8.9-41.5 points [95% CI, 2.2-15.5 to 21.0-62.0]) and worse KOOS QoL subscores at 2 years (mean, 25.3 points [95% CI, 13.6-37.0]). CONCLUSION: Complex meniscal tears, larger extrusion, cartilage injuries, and larger meniscal excision were significant and clinically relevant prognostic factors for worse outcomes 1 and 2 years after APM. REGISTRATION: NCT01002794 (ClinicalTrials.gov identifier).

No Difference in the KOOS Quality of Life Subscore Between Anatomic Double-Bundle and Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction of the Knee: A Prospective Randomized Controlled Trial With 2 Years' Follow-up.

BACKGROUND: The double-bundle reconstruction technique was developed to resemble the properties of the native anterior cruciate ligament (ACL) more closely than the conventional single-bundle technique. The clinical benefit of the operative procedure is controversial, and there is a need for studies with a focus on patient-reported outcomes (PROs). STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. HYPOTHESIS: Anatomic double-bundle ACL reconstruction would be superior to anatomic single-bundle reconstruction regarding the change in the Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) subscore from baseline to 2-year follow-up. METHODS: According to sample size calculations, 120 patients aged 18 to 40 years with a primary ACL injury of their knee were randomized to the anatomic double-bundle or anatomic single-bundle reconstruction groups. Patients with posterior cruciate ligament, posterolateral corner, or lateral collateral ligament injuries or with established osteoarthritis were excluded. Patients with residual laxity from a coexistent medial collateral ligament injury were excluded. Data were registered at baseline, 1 year, and 2 years. In 24 patients, postoperative 3-dimensional computed tomography was performed to verify the positioning of the bundles. The outcome measures were the change in KOOS subscores and the International Knee Documentation Committee 2000 subjective score, pivot-shift test result, Lachman test finding, KT-1000 arthrometer measurement, activity level, return-to-sports rate, and osteoarthritic changes on radiographs. A linear mixed model was used for the analysis of all the PROs, including the primary outcome. RESULTS: The change in the KOOS QoL subscore from baseline to 2-year follow-up was not different between the double- and single-bundle groups (mean change, 29.2 points vs 28.7 points, respectively; -0.5-point difference; 95% CI, -8.4 to 7.4 points; P = .91). Neither were there any differences between the 2 groups in the remaining PROs, knee laxity measurements, or activity levels of the patients. Radiological signs of osteoarthritis were found in 2 patients. Eleven patients had a graft rupture: 8 in the single-bundle group and 3 in the double-bundle group ( P = .16). Three-dimensional computed tomography of the knees verified the positioning of the anteromedial bundle, posterolateral bundle, and single-bundle grafts to be within acceptable limits. CONCLUSION: There was no difference in the KOOS QoL subscore, the remaining PROs, knee laxity measurements, or activity levels comparing the double- and single-bundle ACL reconstruction techniques. The number of bundles does not seem to influence clinical and subjective outcomes, as long as the tunnels are adequately positioned. Registration: NCT01033188 ( ClinicalTrials.gov identifier).

Risk of Revision Was Not Reduced by a Double-bundle ACL Reconstruction Technique: Results From the Scandinavian Registers.

BACKGROUND: Double-bundle anterior cruciate ligament (ACL) reconstruction has demonstrated improved biomechanical properties and moderately better objective outcomes compared with single-bundle reconstructions. This could make an impact on the rerupture rate and reduce the risk of revisions in patients undergoing double-bundle ACL reconstruction compared with patients reconstructed with a traditional single-bundle technique. The National Knee Ligament Registers in Scandinavia provide information that can be used to evaluate the revision outcome after ACL reconstructions. QUESTIONS/PURPOSES: The purposes of the study were (1) to compare the risk of revision between double-bundle and single-bundle reconstructions, reconstructed with autologous hamstring tendon grafts; (2) to compare the risk of revision between double-bundle hamstring tendon and single-bundle bone-patellar tendon-bone autografts; and (3) to compare the hazard ratios for the same two research questions after Cox regression analysis was performed. METHODS: Data collection of primary ACL reconstructions from the National Knee Ligament Registers in Denmark, Norway, and Sweden from July 1, 2005, to December 31, 2014, was retrospectively analyzed. A total of 60,775 patients were included in the study; 994 patients were reconstructed with double-bundle hamstring tendon grafts, 51,991 with single-bundle hamstring tendon grafts, and 7790 with single-bundle bone-patellar tendon-bone grafts. The double-bundle ACL-reconstructed patients were compared with the two other groups. The risk of revision for each research question was detected by the risk ratio, hazard ratio, and the corresponding 95% confidence intervals. Kaplan-Meier analysis was used to estimate survival at 1, 2, and 5 years for the three different groups. Furthermore, a Cox proportional hazard regression model was applied and the hazard ratios were adjusted for country, age, sex, meniscal or chondral injury, and utilized fixation devices on the femoral and tibial sides. RESULTS: There were no differences in the crude risk of revision between the patients undergoing the double-bundle technique and the two other groups. A total of 3.7% patients were revised in the double-bundle group (37 of 994 patients) versus 3.8% in the single-bundle hamstring tendon group (1952 of 51,991; risk ratio, 1.01; 95% confidence interval (CI), 0.73-1.39; p = 0.96), and 2.8% of the patients were revised in the bone-patellar tendon-bone group (219 of the 7790 bone-patellar tendon-bone patients; risk ratio, 0.76; 95% CI, 0.54-1.06; p = 0.11). Cox regression analysis with adjustment for country, age, sex, menisci or cartilage injury, and utilized fixation device on the femoral and tibial sides, did not reveal any further difference in the risk of revision between the single-bundle hamstring tendon and double-bundle hamstring tendon groups (hazard ratio, 1.18; 95% CI, 0.85-1.62; p = 0.33), but the adjusted hazard ratio showed a lower risk of revision in the single-bundle bone-patellar tendon-bone group compared with the double-bundle group (hazard ratio, 0.62; 95% CI, 0.43-0.90; p = 0.01). Comparisons of the graft revision rates reported separately for each country revealed that double-bundle hamstring tendon reconstructions in Sweden had a lower hazard ratio compared with the single-bundle hamstring tendon reconstructions (hazard ratio, 1.00 versus 1.89; 95% CI, 1.09-3.29; p = 0.02). Survival at 5 years after index surgery was 96.0% for the double-bundle group, 95.4% for the single-bundle hamstring tendon group, and 97.0% for the single-bundle bone-patellar tendon-bone group. CONCLUSIONS: Based on the data from all three national registers, the risk of revision was not influenced by the reconstruction technique in terms of using single- or double-bundle hamstring tendons, although national differences in survival existed. Using bone-patellar tendon-bone grafts lowered the risk of revision compared with double-bundle hamstring tendon grafts. These findings should be considered when deciding what reconstruction technique to use in ACL-deficient knees. Future studies identifying the reasons for graft rerupture in single- and double-bundle reconstructions would be of interest to understand the findings of the present study. LEVEL OF EVIDENCE: Level III, therapeutic study.

Tunnel widening in single- versus double-bundle anterior cruciate ligament reconstructed knees.

PURPOSE: The consequence of tunnel widening after ACL reconstructions is foremost of importance in case of revision surgery. Tunnel expansion leads to bone loss close to the joint, and additional surgery with bone grafting prior to revision surgery might be necessary. The purpose of the study was to measure widening of the tunnels in single-bundle (SB) and double-bundle (DB) ACL reconstructed knees during the first year after surgery, detected by a novel, semi-automated 3D CT imaging modality. Our hypothesis was that there would be a difference between the initial tunnel size and the size measured one year post-operatively due to the tunnel widening process. Further, the purpose was to evaluate whether there were any differences in the amount of tunnel widening between the two surgical techniques. METHODS: Twenty patients who underwent DB ACL reconstruction, and 22 patients who underwent SB ACL reconstruction, performed a CT scan of the bony tunnels, during their first days after surgery and one year post-operatively. The CT scans were transformed into 3D CT reconstructions, and the tunnels were measured with the "best-fit cylinder" method, measurements at the level of tunnel aperture and 10.0 mm from the joint line. RESULTS: All tunnels in the DB and SB ACL reconstructed knees exhibited widening during the first year after the operation (p < 0.001). The SB femoral tunnels showed more widening compared to the DB femoral AM tunnels (1.4 ± 0.9 vs. 0.5 ± 0.6 mm) (p < 0.001), and the SB tibial tunnels widened more compared to the DB tibial PL tunnels (1.0 ± 1.0 vs. 0.5 ± 0.6) (p < 0.043). CONCLUSION: All tunnels widened during the first year after the ACL reconstruction with a larger amount of widening in the SB tunnels compared to the DB femoral AM tunnels and the DB tibial PL tunnels. This is the first study to detect tunnel widening in DB reconstructed knees through a semi-automated 3D CT imaging modality. LEVEL OF EVIDENCE: Prospective cohort study, Level III.

Measurements of bone tunnel size in anterior cruciate ligament reconstruction: 2D versus 3D computed tomography model.

BACKGROUND: Revision anterior cruciate ligament (ACL) reconstruction requires a precise evaluation of previous tunnel locations and diameters. Enlargement of the tunnels, despite not usually affecting primary reconstruction outcomes, plays an important role in revision ACL management. Three dimensional (3D) computed tomography (CT) models are reported to be the most accurate method for identifying the tunnel position and possible conflicts with a revision tunnel placement. However, the ability of 3D CT to measure the tunnel size is still not proven. The goal of this study was to evaluate the ability of measuring the size of the bone tunnels in ACL reconstructed knees with 3D CT compared to the traditional two dimensional (2D) CT method. METHODS: Twenty-four patients had CT scans performed immediately following ACL reconstruction surgery. Their femoral tunnels size were measured by a standard 2D CT measurement and then compared with three novel 3D CT measuring methods: the best transverse section method, the best fit cylinder method and the wall thickness method. The drill size used during surgery was used as a control measure for the tunnel width. Intra-class correlation coefficients were obtained. RESULTS: The intra-class correlation coefficient and respective 95% confidence interval range (ICC [95%CI]) for the three methods compared with the drill sizes were 0.899 [0.811-0.947] for the best transverse section method, 0.745 [0.553-0.862] for the best fit cylinder method, -0.004 [-0.081 to -0.12] for the wall thickness method and 0.922 [0.713-0.97] for the 2D CT method. The mean differences compared to the drill size were 0.02 mm for the best fit transverse section method, 0.01 mm for the best fit cylinder diameter method, 3.34 mm for the wall thickness method and 0.29 mm for the 2D CT method. The intra-rater agreement (ICC [95%CI]) was excellent for the best transverse section method 0.999 [0.998-0.999] and the 2D CT method 0.969 [0.941-0.984]. CONCLUSIONS: The 3D best transverse section method presented a high correlation to the drill sizes and high intra-rater agreement, and was the best method for ACL tunnel evaluation in a 3D CT based model.

Biomechanical comparison of interference screws and combination screw and sheath devices for soft tissue anterior cruciate ligament reconstruction on the tibial side.

BACKGROUND: The tibial fixation site has been reported to be the weakest point in anterior cruciate ligament (ACL) reconstructions. Numerous interference screws and combination screw and sheath devices are available for soft tissue fixation, and a biomechanical comparison of these devices is necessary. HYPOTHESIS: Combination screw and sheath devices would provide superior soft tissue fixation properties compared with interference screws in a porcine model. STUDY DESIGN: Controlled laboratory study. METHODS: Eight different intratunnel tibial soft tissue fixation devices were biomechanically tested in a porcine model with bovine tendons, with 10 specimens per group. The soft tissue fixation devices included 3 interference screws-the Bio-Interference Screw, BIOSURE PK, and RCI Screw-and 5 combination screw and sheath devices (combination devices)-the AperFix II, BIOSURE SYNC, ExoShape, GraftBolt, and INTRAFIX. The specimens were subjected to cyclic (1000 cycles, 50-250 N, 0.5 Hz) and pull-to-failure loading (50 mm/min) with a dynamic tensile testing machine. Ultimate failure load (N), cyclic displacement (mm), pull-out stiffness (N/mm), displacement at failure (mm), load at 3 mm displacement (N), and mechanism of failure were recorded. RESULTS: The ultimate failure loads were highest for the GraftBolt (1136 ± 115.6 N), followed by the INTRAFIX (1127 ± 155.0 N), AperFix II (1122 ± 182.9 N), BIOSURE PK (990.8 ± 182.1 N), Bio-Interference Screw (973.3 ± 95.82 N), BIOSURE SYNC (829.5 ± 172.4 N), RCI Screw (817.7 ± 113.9 N), and ExoShape (814.7 ± 178.8 N). The AperFix II, GraftBolt, and INTRAFIX devices were significantly stronger than the BIOSURE SYNC, RCI Screw, and ExoShape. Although the 3 strongest devices were combination screw and sheath devices, no significant differences were observed between the ultimate failure strengths of the screw and combination devices when compared as groups. The least amount of cyclic displacement after 1000 cycles was observed for the GraftBolt (1.38 ± 0.27 mm), followed by the AperFix II (1.58 ± 0.21 mm), Bio-Interference Screw (1.61 ± 0.22 mm), INTRAFIX (1.63 ± 0.15 mm), ExoShape (1.68 ± 0.30 mm), BIOSURE PK (1.72 ± 0.29 mm), BIOSURE SYNC (1.92 ± 0.59 mm), and RCI Screw (1.97 ± 0.39 mm). The GraftBolt allowed significantly less displacement than did the BIOSURE SYNC and RCI Screw. Similarly, no significant differences were observed between the cyclic displacements of the screws and combination devices when compared as groups. CONCLUSION: The combination screw and sheath devices did not provide superior soft tissue fixation properties compared with the interference screws alone in a porcine model. Although the highest ultimate failure loads and least amounts of cyclic displacement were observed for combination devices, group comparisons of screw and combination devices did not result in any significant differences for ultimate failure load and cyclic displacement. CLINICAL RELEVANCE: It is important to consider that these results represent device performance in an in vitro animal model and are not directly transferrable to an in vivo clinical situation. The combination of a sheath and screw did not consistently result in improved fixation characteristics compared with interference screw fixation.