Precision Anterior Cruciate Ligament Reconstruction.

Precision anterior cruciate ligament reconstruction (ACLR) refers to the individualized approach to prerehabilitation, surgery (including anatomy, bony morphology, and repair/reconstruction of concomitant injuries), postrehabilitation, and functional recovery. This individualized approach is poised to revolutionize orthopedic sports medicine, aiming to improve patient outcomes. The purpose of this article is to provide a summary of precision ACLR, from the time of diagnosis to the time of return to play, with additional insight into the future of ACLR.

Quantitative Magnetic Resonance Imaging of Lateral Compartment Articular Cartilage After Lateral Extra-articular Tenodesis.

BACKGROUND: Concerns have arisen that anterior cruciate ligament reconstruction (ACLR) with lateral extra-articular tenodesis (LET) may accelerate the development of posttraumatic osteoarthritis in the lateral compartment of the knee. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate whether the augmentation of ACLR with LET affects the quality of lateral compartment articular cartilage on magnetic resonance imaging (MRI) at 2 years postoperatively. We hypothesized that there would be no difference in T1rho and T2 relaxation times when comparing ACLR alone with ACLR + LET. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A consecutive subgroup of patients at the Fowler Kennedy Sport Medicine Clinic participating in the STABILITY 1 Study underwent bilateral 3-T MRI at 2 years after surgery. The primary outcome was T1rho and T2 relaxation times. Articular cartilage in the lateral compartment was manually segmented into 3 regions of the tibia (lateral tibia [LT]-1 to LT-3) and 5 regions of the femur (lateral femoral condyle [LFC]-1 to LFC-5). Analysis of covariance was used to compare relaxation times between groups, adjusted for lateral meniscal tears and treatment, cartilage and bone marrow lesions, contralateral relaxation times, and time since surgery. Semiquantitative MRI scores according to the Anterior Cruciate Ligament OsteoArthritis Score were compared between groups. Correlations were used to determine the association between secondary outcomes (including results of the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Lower Extremity Functional Scale, 4-Item Pain Intensity Measure, hop tests, and isokinetic quadriceps and hamstring strength tests) and cartilage relaxation. RESULTS: A total of 95 participants (44 ACLR alone, 51 ACLR + LET) with a mean age of 18.8 years (61.1% female [58/95]) underwent 2-year MRI (range, 20-36 months). T1rho relaxation times were significantly elevated for the ACLR + LET group in LT-1 (37.3 ± 0.7 ms vs 34.1 ± 0.8 ms, respectively; P = .005) and LFC-2 (43.9 ± 0.9 ms vs 40.2 ± 1.0 ms, respectively; P = .008) compared with the ACLR alone group. T2 relaxation times were significantly elevated for the ACLR + LET group in LFC-1 (51.2 ± 0.7 ms vs 49.1 ± 0.7 ms, respectively; P = .03) and LFC-4 (45.9 ± 0.5 ms vs 44.2 ± 0.6 ms, respectively; P = .04) compared with the ACLR alone group. All effect sizes were small to medium. There was no difference in Anterior Cruciate Ligament OsteoArthritis Scores between groups (P = .99). Weak negative associations (rs = -0.27 to -0.22; P < .05) were found between relaxation times and quadriceps and hamstring strength in the anterolateral knee, while all other correlations were nonsignificant (P > .05). CONCLUSION: Increased relaxation times demonstrating small to medium effect sizes suggested early biochemical changes in articular cartilage of the anterolateral compartment in the ACLR + LET group compared with the ACLR alone group. Further evidence and long-term follow-up are needed to better understand the association between these results and the potential risk of the development of osteoarthritis in our patient cohort.

Editorial Commentary: Locking Plate Removal Is Safe and May Improve Function 1 Year After Medial Opening Wedge High Tibial Osteotomy.

The development of angular stable locking late fixation in realignment osteotomy has resulted in the ability to be more aggressive with weight bearing and rehabilitation after high tibial osteotomy. One of the downsides of some of these plate fixators is the degree of soft-tissue irritation and discomfort that can be experienced by many patients, resulting in the need for hardware removal. Studies have shown greater than 50% of patients requiring hardware removal with no resulting loss of correction, although there may be cultural reasons for the higher number, not solely attributable to the symptom profile. It is encouraging to see that after 1 year postoperatively, hardware removal after high tibial osteotomy not only is safe but also results in a clinically important improvement in pain and function, with progressive bone healing out to 2 years.

Anterior Cruciate Ligament Reconstruction Plus Lateral Extra-articular Tenodesis Has a Similar Return-to-Sport Rate to Anterior Cruciate Ligament Reconstruction Alone but a Lower Failure Rate.

PURPOSE: To determine whether the addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament reconstruction (ACLR) would improve return-to-sport (RTS) rates in young, active patients who play high-risk sports. METHODS: This multicenter randomized controlled trial compared standard hamstring tendon ACLR with combined ACLR and LET using a strip of the iliotibial band (modified Lemaire technique). Patients aged 25 years or younger with an anterior cruciate ligament-deficient knee were included. Patients also had to meet 2 of the following criteria: (1) pivot-shift grade 2 or greater, (2) participation in a high-risk or pivoting sport, and (3) generalized ligamentous laxity. Time to return and level of RTS were determined via administration of a questionnaire at 24 months postoperatively. RESULTS: We randomized 618 patients in this study, 553 of whom played high-risk sports preoperatively. The proportion of patients who did not RTS was similar between the ACLR (11%) and ACLR-LET (14%) groups; however, the graft rupture rate was significantly different (11.2% in ACLR group vs 4.1% in ACLR-LET group, P = .004). The most cited reason for no RTS was lack of confidence and/or fear of reinjury. A stable knee was associated with nearly 2 times greater odds of returning to a high-level high-risk sport postoperatively (odds ratio, 1.92; 95% confidence interval, 1.11-3.35; P = .02). There were no significant differences in patient-reported functional outcomes or hop test results between groups (P > .05). Patients who returned to high-risk sports had better hamstring symmetry than those who did not RTS (P = .001). CONCLUSIONS: At 24 months postoperatively, patients who underwent ACLR plus LET had a similar RTS rate to those who underwent ACLR alone. Although the subgroup analysis did not show a statistically significant increase in RTS with the addition of LET, on returning, the addition of LET kept subjects playing longer by reducing graft failure rates. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

A bifactor model supports unidimensionality of the International Knee Documentation Committee Subjective Knee Form in young active patients with anterior cruciate ligament tears: a retrospective analysis of a randomized controlled trial.

BACKGROUND: The International Knee Documentation Committee Subjective Knee Form (IKDC) is the most highly recommended patient reported outcome measure for assessing patients with anterior cruciate ligament (ACL) injuries and those undergoing ACL reconstruction (ACLR) surgery. The IKDC was developed as a unidimensional instrument for a variety of knee conditions. Structural validity, which determines how an instrument is scored, has not been definitively confirmed for the IKDC in respondents with ACL injuries, and in fact an alternative two-factor/subscale structure has been proposed in this population. The purpose of this study was to determine the most appropriate structure and scoring system for the IKDC in young active patients following ACL injury. METHODS: In total, 618 young patients deemed at high risk of graft rupture were randomized into the Stability 1 trial. Of the trial participants, 606 patients (98%) completed a baseline IKDC questionnaire used for this analysis. A cross sectional retrospective secondary data analysis of the Stability 1 baseline IKDC data was completed to assess the structural validity of the IKDC using exploratory and confirmatory factor analyses. Factor analyses were used to test model fit of the intended one-factor structure, a two-factor structure, and alternative four-factor and bifactor structures (i.e., a combination of a unidimensional factor with additional specific factors) of the IKDC, in a dataset of young active ACL patients. RESULTS: The simple one-factor and two-factor structures of the IKDC displayed inadequate fit in our dataset of young ACL patients. A bifactor model provided the best fit. This model contains one general factor that is substantially associated with all items, plus four secondary, more specific content factors (symptoms, activity level, activities of daily living, and sport) with generally weaker associations to subsets of items. Although the single-factor model did not provide unambiguous support to unidimensionality of the IKDC based on fit indices, the bifactor model supports unidimensionality of the IKDC when covariance between items with similar linguistic structure, response options, or content are acknowledged. CONCLUSIONS: Overall, findings of a bifactor model with evidence of a reliable general factor well defined by all items lends support to continue interpreting and scoring this instrument as unidimensional. This should be confirmed in other samples. Clinically, based on these findings, the IKDC can be represented by a single score for young active patients with ACL tears. A more nuanced interpretation would also consider secondary factors such as sport and activity level. TRIAL REGISTRATION: The Stability 1 trial for which these data were collected was registered on ClinicalTrial.gov (NCT02018354).

Meniscal repair at the time of primary ACLR does not negatively influence short term knee stability, graft rupture rates, or patient-reported outcome measures: the STABILITY experience.

PURPOSE: To assess how meniscal repair and excision impact short term patient-reported outcome measures (PROMs), knee stability, and early graft rupture rates following primary hamstring anterior cruciate ligament reconstruction (ACLR) with or without lateral extra-articular tenodesis (LET) in a group of young active patients where meniscal repair is commonly advocated. METHODS: Six hundred and eighteen patients under 25 years of age at high-risk of graft failure following ACLR were recruited to the Stability 1 study. Multivariable regression models were developed to identify statistically and clinically significant surgical and demographic predictors of Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee Subjective Knee Form (IKDC), ACL Quality of Life Questionnaire (ACL-QOL) and Marx Activity Rating Scale (MARS) scores. Chi-Square tests of independence were used to explore the association between meniscal status (torn, not torn), meniscal treatment (excision or repair), graft rupture, and rotatory knee laxity. RESULTS: Medial meniscus repair was associated with worse outcomes on the KOOS (ß = -1.32, 95% CI: -1.57 to -1.10, p = 0.003), IKDC (ß = -1.66, 95% CI: -1.53 to -1.02, p = 0.031) and ACL-QOL (ß = -1.25, 95% CI: -1.61 to 1.02, p = n.s.). However, these associations indicated small, clinically insignificant changes based on reported measures of clinical relevance. Other important predictors of post-operative PROMs included age, sex, and baseline scores. Medial meniscus excision and lateral meniscus treatment (repair or excision) did not have an important influence on PROMs. There was no significant association between meniscal treatment and graft rupture or rotatory knee laxity. CONCLUSION: While repairing the medial meniscus may result in a small reduction in PROM scores at two-year follow-up, these differences are not likely to be important to patients or clinicians. Any surgical morbidity associated with meniscal repair appears negligible in terms of PROMs. Meniscal repair does not affect rotatory laxity or graft failure rates in the short term. Therefore, meniscal repair should likely be maintained as the standard of care for concomitant meniscal tears with ACLR. LEVEL OF EVIDENCE: III.

Predicting Patient Loss to Follow-up in the STABILITY 1 Study: A Multicenter, International, Randomized Controlled Trial of Young, Active Patients Undergoing ACL Reconstruction.

BACKGROUND: Patients lost to follow-up (LTF) impact even the most meticulously planned randomized controlled trials. Identifying patients at high risk for becoming LTF and employing strategies to retain these patients may reduce attrition bias. METHODS: A cohort of 618 young, active patients undergoing anterior cruciate ligament reconstruction in the STABILITY 1 study was analyzed. Patients completed clinical testing and 9 questionnaires at 3, 6, 12, and 24 months. Multivariable logistic regression was performed for 5 different definitions of LTF. Patient characteristics and study site were included as predictors. RESULTS: The LTF rate was 8.3%. Current or previous smokers (odds ratio [OR] = 2.77; 95% confidence interval [CI]: 1.20 to 5.96), those employed part-time (OR = 2.31; 95% CI: 1.04 to 5.14), and those with body mass index (BMI) of ≥25 kg/m2 had significantly greater odds of becoming LTF compared with nonsmokers, students, and those with BMI of <25 kg/m2, respectively. Those employed part-time were >8 times more likely (95% CI: 2.66 to 26.28) to become LTF compared with students within the first year. Postoperative BMI of ≥25 kg/m2 was significantly associated with 2 times greater odds of missing the in-person clinical examination at any visit or becoming LTF after the first postoperative year. The clinical site was the single largest predictor of missing data at any visit. CONCLUSIONS: Current or previous smoking, part-time employment, and BMI of ≥25 kg/m2 were significant predictors of becoming LTF, and part-time employment was significantly associated with early LTF. BMI of ≥25 kg/m2 was also associated with late LTF and clinical LTF. The clinical site was significantly associated with missing data at any visit. While we cannot accurately predict who will become LTF, investigators should be aware of these factors to identify high-risk patients and focus retention strategies accordingly. CLINICAL RELEVANCE: Understanding factors related to becoming LTF in young, active patients undergoing anterior cruciate ligament reconstruction can help investigators target retention strategies to reduce LTF in studies requiring clinical follow-up in similar populations.

Quadriceps tendon autograft is becoming increasingly popular in revision ACL reconstruction.

PURPOSE: To evaluate trends in revision anterior cruciate ligament reconstruction (ACL-R), with emphasis on intra-articular findings, grafts, and concurrent procedures. It was hypothesized that revision ACL-Rs over time show a trend toward increased complexity with increased use of autografts over allografts. METHODS: This was a two-center retrospective study including patients undergoing revision ACL-R between 2010 and 2020. Demographic and surgical data including intra-articular findings and concurrent procedures were collected and compared for the time periods 2010-2014 and 2015-2020. All collected variables were compared between three pre-defined age groups (< 20 years, 20-30 years, > 30 years), right and left knees, and males and females. A time series analysis was performed to assess trends in revision ACL-R. RESULTS: This study included 260 patients with a mean age of 26.2 ± 9.4 years at the time of the most recent revision ACL-R, representing the first, second, third, and fourth revision ACL-R for 214 (82%), 35 (14%), 10 (4%), and 1 (< 1%) patients, respectively. Patients age > 30 years showed a significantly longer mean time from primary ACL-R to most recent revision ACL-R (11.1 years), compared to patients age < 20 years (2.2 years, p < 0.001) and age 20-30 years (5.5 years, p < 0.05). Quadriceps tendon autograft was used significantly more often in 2015-2020 compared to 2010-2014 (49% vs. 18%, p < 0.001). A high rate of concurrently performed procedures including meniscal repairs (45%), lateral extra-articular tenodesis (LET; 31%), osteotomies (13%), and meniscal allograft transplantations (11%) was shown. Concurrent LET was associated with intact cartilage and severely abnormal preoperative knee laxity and showed a statistically significant and linear increase over time (p < 0.05). Intact cartilage (41%, p < 0.05), concurrent medial meniscal repairs (39%, p < 0.05), and LET (35%, non-significant) were most frequently observed in patients aged < 20 years. CONCLUSION: Quadriceps tendon autograft and concurrent LET are becoming increasingly popular in revision ACL-R. Intact cartilage and severely abnormal preoperative knee laxity represent indications for LET in revision ACL-R. The high rate of concurrent procedures observed demonstrates the high surgical demands of revision ACL-R. LEVEL OF EVIDENCE: Level III.

Same knee, different goals: patients and surgeons have different priorities related to ACL reconstruction.

PURPOSE: The priorities of patients should be shared by those treating them. Patients and surgeons are likely to have different priorities surrounding anterior cruciate ligament reconstruction (ACLR), with implications for shared decision-making and patient education. The optimal surgical approach for ACLR is constantly evolving, and the magnitude of treatment effect necessary for evidence to change surgical practice is unknown. The aim of this study was to determine (1) the priorities of surgeons and patients when making decisions regarding ACLR and (2) the magnitude of reduction in ACLR graft failure risk that orthopaedic surgeons require before changing practice. METHODS: This study followed a cross-sectional survey design. Three distinct electronic surveys were administered to pre-operative ACLR patients, post-operative ACLR patients, and orthopaedic surgeons. Patients and surgeons were asked about the importance of various outcomes and considerations pertaining to ACLR. Surgeons were asked scenario-based questions regarding changing practice for ACLR based on new research. RESULTS: Surgeons were more likely to prioritize outcomes related to the surgical knee itself, whereas patients were more likely to prioritize outcomes related to their daily lifestyle and activities. Knee instability and risk of re-injury were unanimous top priorities among all three groups. A mean relative risk reduction in ACLR graft failure of about 50% was required by orthopaedic surgeons to change practice regardless of the type of change, or patient risk profile. CONCLUSION: There are discrepancies between the priorities of surgeons and patients, and orthopaedic surgeons appear resistant to changing practice for ACLR. LEVEL OF EVIDENCE: IV.

The Medial structures of the knee have a significant contribution to posteromedial rotational laxity control in the PCL-deficient knee.

PURPOSE: Various reconstruction techniques have been employed to restore normal kinematics to PCL-deficient knees; however, studies show that failure rates are still high. Damage to secondary ligamentous stabilizers of the joint, which commonly occurs concurrently with PCL injuries, may contribute to these failures. The main objective of this study was to quantify the biomechanical contributions of the deep medial collateral ligament (dMCL) and posterior oblique ligament (POL) in stabilizing the PCL-deficient knee, using a joint motion simulator. METHODS: Eight cadaveric knees underwent biomechanical analysis of posteromedial stability and rotatory laxity using an AMTI VIVO joint motion simulator. Combined posterior force (100 N) and internal torque (5 Nm) loads, followed by pure internal/external torques (± 5 Nm), were applied at 0, 30, 60 and 90° of flexion. The specimens were tested in the intact state, followed by sequential sectioning of the PCL, dMCL, POL and sMCL. The order of sectioning of the dMCL and POL was randomized, providing n = 4 for each cutting sequence. Changes in posteromedial displacements and rotatory laxities were measured, as were the biomechanical contributions of the dMCL, POL and sMCL in resisting these loads in a PCL-deficient knee. RESULTS: Overall, it was observed that POL transection caused increased posteromedial displacements and internal rotations in extension, whereas dMCL transection had less of an effect in extension and more of an effect in flexion. Although statistically significant differences were identified during most loading scenarios, the increases in posteromedial displacements and rotatory laxity due to transection of the POL or dMCL were usually small. However, when internal torque was applied to the PCL-deficient knee, the combined torque contributions of the dMCL and POL towards resisting rotation was similar to that of the sMCL. CONCLUSION: The dMCL and POL are both important secondary stabilizers to posteromedial translation in the PCL-deficient knee, with alternating roles depending on flexion angle. Thus, in a PCL-deficient knee, concomitant injuries to either the POL or dMCL should be addressed with the aim of reducing the risk of PCL reconstruction failure.

Lateral Extra-articular Tenodesis Reduces Failure of Hamstring Tendon Autograft Anterior Cruciate Ligament Reconstruction: 2-Year Outcomes From the STABILITY Study Randomized Clinical Trial.

BACKGROUND: Persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR) has been correlated with poor clinical outcomes and graft failure. HYPOTHESIS: We hypothesized that a single-bundle, hamstring ACLR in combination with a lateral extra-articular tenodesis (LET) would reduce the risk of ACLR failure in young, active individuals. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: This is a multicenter, prospective, randomized clinical trial comparing a single-bundle, hamstring tendon ACLR with or without LET performed using a strip of iliotibial band. Patients 25 years or younger with an ACL-deficient knee were included and also had to meet at least 2 of the following 3 criteria: (1) grade 2 pivot shift or greater, (2) a desire to return to high-risk/pivoting sports, (3) and generalized ligamentous laxity (GLL). The primary outcome was ACLR clinical failure, a composite measure of rotatory laxity or a graft rupture. Secondary outcome measures included the P4 pain scale, Marx Activity Rating Scale, Knee injury Osteoarthritis and Outcome Score (KOOS), International Knee Documentation Committee score, and ACL Quality of Life Questionnaire. Patients were reviewed at 3, 6, 12, and 24 months postoperatively. RESULTS: A total of 618 patients (297 males; 48%) with a mean age of 18.9 years (range, 14-25 years) were randomized. A total of 436 (87.9%) patients presented preoperatively with high-grade rotatory laxity (grade 2 pivot shift or greater), and 215 (42.1%) were diagnosed as having GLL. There were 18 patients lost to follow-up and 11 who withdrew (~5%). In the ACLR group, 120/298 (40%) patients sustained the primary outcome of clinical failure, compared with 72/291 (25%) in the ACLR+LET group (relative risk reduction [RRR], 0.38; 95% CI, 0.21-0.52; P < .0001). A total of 45 patients experienced graft rupture, 34/298 (11%) in the ACLR group compared with 11/291 (4%) in the ACL+LET group (RRR, 0.67; 95% CI, 0.36-0.83; P < .001). The number needed to treat with LET to prevent 1 patient from graft rupture was 14.3 over the first 2 postoperative years. At 3 months, patients in the ACLR group had less pain as measured by the P4 (P = .003) and KOOS (P = .007), with KOOS pain persisting in favor of the ACLR group to 6 months (P = .02). No clinically important differences in patient-reported outcome measures were found between groups at other time points. The level of sports activity was similar between groups at 2 years after surgery, as measured by the Marx Activity Rating Scale (P = .11). CONCLUSION: The addition of LET to a single-bundle hamstring tendon autograft ACLR in young patients at high risk of failure results in a statistically significant, clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after surgery. REGISTRATION: NCT02018354 ( ClinicalTrials.gov identifier).

Trends in knee arthroscopy utilization: a gap in knowledge translation.

PURPOSE: To evaluate the longitudinal trends in knee arthroscopy utilization in relation to published negative randomized controlled trials, focusing on annual rates, patient demographics and associated 30-day post-operative complications. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried using Current Procedural Terminology billing codes to identify arthroscopy cases between 2006 and 2016. 30-day post-operative complications were identified, and potential risk factors analysed using univariate and multivariate analyses. RESULTS: 68,346 patients underwent knee arthroscopy, of which 47,446 (69.5%) represented partial meniscectomies. The annual procedural rate, as a proportion of all reported cases, increased significantly from 2006 (0.3%) to 2016 (1.6%; p < 0.001), along with a significant increase in average patient age (44.3 ± 15.5 to 48.4 ± 14.5; p < 0.001). Specifically focusing on the meniscectomy cohort, average patient age significantly increased from 47.9 ± 15.1 to 50.7 ± 13.5 (p = 0.001). The overall incidence of complications was 2.0% (n = 1333), with major complications in 0.9% (n = 639) and minor complications in 1.0% (n = 701). Common complications included a return to the operating room (0.5%), deep vein thrombosis/thrombophlebitis (0.4%), and superficial infection (0.2%). Operating time > 90 min, diabetes, steroid use, ASA class 2+, and dialysis-dependency were the predictors of overall complication rates. CONCLUSION: Despite the publication of negative trials and new clinical practice guidelines, knee arthroscopy utilization and average patient age continue to increase. Given the high utilization, even low adverse event rates equate to substantial numbers of patients with minor and major complications. The NSQIP data show a gap in knowledge translation to clinical practice and highlight the need for improved clinical guidelines. LEVEL OF EVIDENCE: Cohort study; Level III.

Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis.

BACKGROUND: Persistent clinical instability after anterior cruciate ligament (ACL) reconstruction may be associated with injury to the anterolateral structures and has led to renewed interest in anterolateral extra-articular procedures. The influence of these procedures on knee kinematics is controversial. Purpose/Hypothesis: The purpose was to investigate the biomechanical properties of anatomic anterolateral ligament (ALL) reconstruction and a modified Lemaire procedure (lateral extra-articular tenodesis [LET]) in combination with ACL reconstruction as compared with isolated ACL reconstruction in the setting of deficient anterolateral structures (ALL and Kaplan fibers). It was hypothesized that both techniques would reduce tibial internal rotation when combined with ACL reconstruction in the setting of anterolateral structure deficiency. STUDY DESIGN: Controlled laboratory study. METHODS: A 6 degrees of freedom robotic system was used to assess tibial internal rotation, a simulated pivot-shift test, and anterior tibial translation in 10 paired fresh-frozen cadaveric knees. The following states were tested: intact; sectioned ACL, ALL, and Kaplan fibers; ACL reconstruction; and an anterolateral extra-articular procedure (various configurations of ALL reconstruction and LET). Knees within a pair were randomly assigned to either ALL reconstruction or LET with a graft tension of 20 N and a randomly assigned fixation angle (30° or 70°). ALL reconstruction was then repeated and secured with a graft tension of 40 N. RESULTS: In the setting of deficient anterolateral structures, ACL reconstruction was associated with significantly increased residual laxity for tibial internal rotation (up to 4°) and anterior translation (up to 2 mm) laxity as compared with the intact state. The addition of ALL reconstruction or LET after ACL reconstruction significantly reduced tibial internal rotation in most testing scenarios to values lower than the intact state (ie, overconstraint). Significantly greater reduction in laxity with internal rotation and pivot-shift testing was found with the LET procedure than ALL reconstruction when compared with the intact state. Combined with ACL reconstruction alone, both extra-articular procedures restored anterior tibial translation to values not significantly different from the intact state with most testing scenarios (usually within 1 mm). CONCLUSION: Residual laxity was identified after isolated ACL reconstruction in the setting of ALL and Kaplan fiber deficiency, and the combination of ACL reconstruction in this setting with either ALL reconstruction or the modified Lemaire LET procedure resulted in significant reductions in tibiofemoral motion at most knee flexion angles, although overconstraint was also identified. ALL reconstruction and LET restored anterior tibial translation to intact values with most testing states. CLINICAL RELEVANCE: ALL reconstruction and lateral extra-articular tenodesis have been described in combination with intra-articular ACL reconstruction to address rotational laxity. This study demonstrated that both procedures resulted in significant reductions of tibial internal rotation versus the intact state independent of graft tension or fixation angle, although anterior tibial translation was generally restored to intact values. The influence of overconstraint with anterolateral knee reconstruction procedures has not been fully evaluated in the clinical setting and warrants continued evaluation based on the findings of this biomechanical study.

Lateral Extra-articular Tenodesis Reduces Rotational Laxity When Combined With Anterior Cruciate Ligament Reconstruction: A Systematic Review of the Literature.

PURPOSE: To determine whether the addition of lateral extra-articular tenodesis (LET) to anterior cruciate ligament (ACL) reconstruction would provide greater control of rotational laxity and improved clinical outcomes compared with ACL reconstruction alone. METHODS: Two independent reviewers searched 9 databases for randomized and nonrandomized clinical studies comparing ACL reconstruction plus LET versus ACL reconstruction alone in a human adult population. All years and 5 languages were included. Animal and cadaveric studies, revision or repair surgical techniques, and studies focused on biomechanical outcomes were excluded. Quality assessment of the included studies was performed with the Cochrane Collaboration tool. Outcomes of interest included the pivot-shift test, KT-1000/-2000 measurements (MEDmetric, San Diego, CA), and International Knee Documentation Committee scores. RESULTS: The literature search yielded 3,612 articles. After titles and abstracts were reviewed, 106 articles were selected for full-text review, of which 29 studies met the inclusion criteria (8 randomized and 21 nonrandomized studies). Of the 8 randomized studies, 3 concluded that the results were nonsignificant between treatment groups, 4 were in favor of the extra-articular tenodesis, and 1 was in favor of the ACL reconstruction alone. The Cochrane Collaboration tool showed an unclear to high risk of bias for most articles. A meta-analysis showed a statistically significant difference for the pivot-shift test (P = .002, I2 = 34%) in favor of ACL reconstruction with LET. No difference was found between the groups for International Knee Documentation Committee scores (P = .75, I2 = 19%) and KT-1000/-2000 measurements (P = .84, I2 = 34%). CONCLUSIONS: Meta-analysis showed a statistically significant reduction in pivot shift in favor of the combined procedure. Studies lacked sufficient internal validity, sample size, methodologic consistency, and standardization of protocols and outcomes. LEVEL OF EVIDENCE: Level III, systematic review of Level I, II, and III studies.

Radiographic landmarks for surgical reconstruction of the anterolateral ligament of the knee.

PURPOSE: To determine the radiographic landmarks of the anterolateral ligament (ALL) on the femur and tibia to assist in intraoperative graft placement during ALL reconstruction. METHODS: The footprints of the ALL, fibular collateral ligament (FCL), popliteus insertion, lateral gastrocnemius insertion, and Gerdy's tubercle were isolated and centrally marked with tantalum beads in thirteen fresh-frozen cadaveric knees. Measurements were taken from the true lateral fluoroscopic images. On the femur, the mean distances from the ALL origin to the FCL origin and from the ALL origin to the popliteus insertion were measured. On the tibia, the mean distances from the ALL insertion to Gerdy's tubercle and from the ALL insertion to the lateral tibial plateau were measured. Furthermore, radiographic descriptions of the ALL origin and insertion were developed. RESULTS: The ALL origin on the femur averaged 3.3 ± 1.5 mm anterior-distal to the FCL origin in one anatomical variant and 5.4 ± 1.4 mm posterior-proximal to the FCL origin in a second variant. The ALL origin was 9.9 ± 2.7 mm from the popliteus insertion. The ALL origin is described as overlying the posterior femoral cortical line, between Blumensaat's line and a line from the posterior condylar articular edge parallel to Blumensaat's line. The ALL insertion on the tibia averaged 24.7 ± 4.5 mm posterior to Gerdy's tubercle and 11.5 ± 2.9 mm distal to the lateral tibial plateau. The tibial ALL insertion is described between the posterior tibial cortical line and a parallel line drawn down from the apex of the tibial spine, and overlying a line drawn perpendicular to the posterior tibial cortical line starting from the apex of the posterior tibial condyles. CONCLUSIONS: Using direct lateral fluoroscopy, radiographic landmarks of the ALL origin and insertion have been described.

Evaluation of early-stage osteochondral defect repair using a biphasic scaffold based on a collagen-glycosaminoglycan biopolymer in a caprine model.

The aim of this study was to evaluate a new collagen-GAG-calcium phosphate biphasic scaffold for the repair of surgically created osteochondral defects in goats. Comparison of morphological, histological and mechanical performance of the repair tissue was made with defects repaired using a synthetic polymer scaffold. Defects were created in the medial femoral condyle (MFC) and lateral trochlear sulcus (LTS) of Boer Cross goats and evaluated at 12 and 26 weeks. It was found that the total histology score of the collagen-GAG based biomaterial (23.8; SD 1.7) provided a significant improvement (p<0.05) over the biphasic PLGA material (19;3) and the empty control defect (17.3;1.2) in the LTS. The overall trajectory of histological and morphological improvement between 12 and 26 weeks was found to be higher for the collagen-GAG scaffold compared to the PLGA material. The occurrence of sub-chondral bone cysts was lower for the collagen-GAG scaffold with an incidence of 17% of defects, compared to 67% for the PLGA material at 26 weeks. The cartilage repair tissue for both materials evaluated was superior after 26 weeks implantation than the empty control with 75% of the collagen-GAG-treated defects showing markedly more hyaline-like cartilage and 50% of the PLGA sites exhibiting hyaline-like appearances, compared to 17% for the empty control. These early stage data indicate biphasic scaffolds based on collagen-GAG and PLGA both provide indications of satisfactory development of a structural repair to surgically prepared osteochondral defects. Furthermore, the biomaterial composition of the collagen-GAG may provide a more favourable environment for osteochondral repair.