Editorial Commentary: Early Outcomes of Suture Tape Augmentation in Quadriceps Tendon Autograft Anterior Cruciate Ligament Reconstruction Are Promising but Require Long-term Proof.

The management of anterior cruciate ligament (ACL) injuries continually evolves, with new interest in all-soft tissue quadriceps tendon autograft, as well as new interest in suture tape augmentation of the graft, particularly in high-risk patients with young age; female sex; lower-limb alignment, tibial, or femoral abnormalities; hyperlaxity; concomitant meniscal and/or additional ligamentous injuries; or participation in high-risk sports. Load-sharing suture tape enhances the biomechanical stability of the reconstructed ACL, especially during the initial ingrowth and ligamentization phase, and biomechanical evidence highlights a reduced risk of graft elongation and failure under the loads encountered during daily physical activities and sport. Optimal tape tensioning could be achieved in knee hyperextension, when the ACL is at maximal length, to avoid overconstraint. The published 2-year outcomes of this technique are excellent. Current comparative studies, however, have not shown superiority. Additional controlled studies and studies with longer-term follow-up are needed, as well as comparison to extra-articular tenodesis augmentation.

Bilateral juvenile osteochondrosis dissecans in monozygotic twins: a case report.

INTRODUCTION: The etiology of osteochondrosis dissecans (OCD), a chondropathy associated with detachment of the subchondral bone and the overlaying cartilage, is not yet fully understood. While repetitive physical exercise-related stress is usually assumed to be the main risk factor for the occurrence of OCD, genetic predisposition could have an underestimated influence on the development of the disease. CASE REPORT: We report a case of monozygotic twins with almost identical stages of bilateral osteochondrosis dissecans of the knee joint. In both patients, initially, a unilateral lesion occurred; despite restricted physical exercise, in the further course of the disease a lesion also developed on the contralateral side. While the lesion found most recently demonstrated an ongoing healing process at a 6-month follow-up, the other three lesions showed a natural course of healing under conservative treatment with significant clinical as well as radiological improvements after one year and complete consolidation in magnetic resonance imaging (MRI) after 2 years. CONCLUSION: There could be a genetic component to the development of OCD, although this has not yet been proven. Based on a two-year MRI follow-up, we were able to show the self-limiting characteristics of juvenile osteochondrosis dissecans.

Tibiofemoral Subluxation on Radiograph as a Predictor of Location and Size of Osteochondritis Dissecans Lesions of the Knee.

Background: Lower limb malalignment has been associated with osteochondritis dissecans (OCD). However, the location of the OCD lesion often is not concordant with the mechanical leg axis. Other potentially modifiable alignment parameters may influence the propensity for impingement of the femoral condyles. Purpose: To assess differences in lower limb alignment (LLA) and relative tibiofemoral position between patients with medial (MFC-OCD) or lateral OCD (LFC-OCD) of the femoral condyle. Study Design: Cohort study; Level of evidence, 3. Methods: Patients ≤30 years old who were diagnosed with unicondylar OCD between January 2010 and January 2020 were eligible for this study. Included were 55 patients (age, 20.8 ± 4.5 years)-46 with MFC-OCD and 9 with LFC-OCD. Preoperative standing long-leg radiographs were studied to obtain primary outcomes-including LLA and mechanical alignment analyses-and secondary outcomes-including knee joint obliquity angle; rotation angle; medial, central (c-subluxation), and lateral subluxation (L-subluxation) of the tibia relative to the femur in the coronal plane; and tibiofemoral joint line center distance (TFJCD). Results: With regard to primary outcomes, LLA was significantly different between MFC-OCD (1.7°± 3.1° varus) and LFC-OCD (2.7 ± 3.1° valgus) (P < .001), and 78% (36/46) of patients with MFC-OCD had varus alignment, whereas 78% (7/9) of patients with LFC-OCD had valgus alignment (P < 0.002). With regard to secondary outcomes, patients with MFC-OCD had a more medial tibial position in relation to the femur, with a significantly smaller rotation angle (5.6°± 2.4° vs 9.6°± 3.6°; P < .001), a smaller C-subluxation (7.2 ± 6.6 vs 14.9 ± 8.8 mm; P < .01), a smaller L-subluxation (2.3 ± 2.6 vs 4.4 ± 2.7 mm; P < .05), and reduced TFJCD (3.5 ± 1.7 vs 6.6 ± 1.8 mm; P < .001) compared with the LFC-OCD group. For patients with MFC-OCD, the size of the OCD was significantly correlated with C-subluxation (r = 0.412; P = .006). Conclusion: LLA was significantly different according to OCD location. In patients with MFC-OCD, the tibia was subluxated medially, resulting in a change of joint geometry by approximation of the medial tibial eminence toward the medial femoral condyle, potentially causing excessive pressure overload and microtrauma of the cartilage. Interestingly, the extent of subluxation was correlated with OCD size.

Noninvasive and Reliable Quantification of Anteromedial Rotatory Knee Laxity: A Pilot Study on Healthy Individuals.

BACKGROUND: Anteromedial rotatory instability (AMRI) of the knee is a complex and severe condition caused by injury to the anterior cruciate ligament and/or the medial collateral ligament. Clinical studies dealing with AMRI are rare, and objective measurements are nonexistent. PURPOSE/HYPOTHESIS: The objectives of this study were, first, to quantify anteromedial rotatory knee laxity in healthy individuals using a noninvasive image analysis software and, second, to assess intra- and interrater reliability and equivalence in measuring anteromedial knee translation (AMT). It was hypothesized that AMT could be reliably quantified using a noninvasive image analysis software. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This prospective proof-of-concept study included healthy individuals aged 16 to 40 years with no history of knee injury or surgery. Three adhesive surface markers were placed on predefined landmarks on the medial side of the knee. Three independent investigators examined anteromedial rotatory knee laxity with an anterior drawer test in different tibial rotations (neutral tibial rotation, 15° of external tibial rotation, and 15° of internal tibial rotation). The entire examination of each knee was recorded, and AMT including the side-to-side difference (SSD) was assessed using a freely available and validated image analysis software (PIVOT iPad application). Group comparisons were performed using a 1-way analysis of variance with Bonferroni-adjusted post hoc analysis. Intraclass correlation coefficients (ICCs) were calculated to assess inter- and intrarater reliability of AMT measurements. Equivalence of measurements was evaluated using the 2 one-sided t-test procedure. RESULTS: Anteromedial rotatory knee laxity was assessed in 30 knees of 15 participants (53% male) with a mean age of 26.2 ± 3.5 years. In all 3 raters, the highest AMT was observed in neutral tibial rotation (range of means, 2.2-3.0 mm), followed by external tibial rotation (range of means, 2.0-2.4 mm) and internal tibial rotation (range of means, 1.8-2.2 mm; P < .05). Intrarater reliability of AMT (ICC, 0.88-0.96) and SSD (ICC, 0.61-0.96) measurements was good to excellent and moderate to excellent, respectively. However, interrater reliability was poor to moderate for AMT (ICC, 0.44-0.73) and SSD (ICC, 0.12-0.69) measurements. Statistically significant equivalence of AMT and SSD measurements was observed between and within raters for almost all testing conditions. CONCLUSION: Anteromedial rotatory knee laxity could be quantified using a noninvasive image analysis software, with the highest AMT observed during neutral tibial rotation in uninjured individuals. Reliability and equivalence of measurements were good to excellent within raters and moderate between raters.

Use of Distal Tibial Cortical Bone Thickness and FRAX Score for Further Treatment Planning in Patients with Trimalleolar Ankle Fractures.

Trimalleolar ankle fractures show a bimodal age distribution, affecting younger men and older women. Postmenopausal women often exhibit low bone mineral density, which contributes to a higher prevalence of osteoporotic-related fractures. The primary goal of this study was to analyse the association of patient characteristics with the cortical bone thickness of the distal tibia (CBTT) in trimalleolar ankle fractures. METHODS: A total of 193 patients with a trimalleolar ankle fracture treated between 2011 and 2020 were included. Patient registries were reviewed regarding demographics, mechanism, and type of injury. The CBTT was assessed in radiographs and CT images. The FRAX score was calculated to estimate the probability for an osteoporotic fracture. A multivariable regression model was calculated to identify independent variables affecting the cortical bone thickness of the distal tibia. RESULTS: Patients older than 55 years were 4.22 (95% CI: 2.12; 8.38) times more likely to be female. In the multivariable regression analysis, female sex (ß -0.508, 95% CI: -0.739; -0.278, p < 0.001) and a higher age (ß -0.009, 95% CI: -0.149; -0.003, p = 0.002) were independent variables associated with a lower CBTT. Patients with a CBTT < 3.5 mm had a higher 10-year probability for a major osteoporotic fracture (12% vs. 7.75%; p = 0.001). CONCLUSIONS: The assessment of the peripheral bone quality in routine computed tomography demonstrated that higher age and female sex are significantly associated with reduced cortical bone thickness of the distal tibia. Patients with a lower CBTT showed a higher probability for a subsequent osteoporotic fracture. In female patients with reduced distal tibial bone quality and associated risk factors, an osteoporosis assessment should be evaluated.

Intact revision rotator cuff repair stabilizes muscle atrophy and fatty infiltration after minimum follow up of two years.

BACKGROUND: The extent of fatty infiltration and rotator cuff (RC) atrophy is crucial for the clinical results after rotator cuff repair (RCR). The purpose of this study was to evaluate changes in fatty infiltration and RC atrophy after revision RCR and to correlate them with functional outcome parameters. METHODS: Patients who underwent arthroscopic revision RCR for symptomatic recurrent full-thickness tear of the supraspinatus tendon between 2008 and 2014 and were retrospectively reviewed with a minimum follow up of 2 years. Magnetic resonance imaging (MRI) was performed pre- and postoperatively to assess 1) tendon integrity after revision RCR according to Sugaya classification, (2) RC atrophy according to Thomazeau classification, and (3) fatty infiltration according to Fuchs MRI classification. Constant score (CS) and the American Shoulder and Elbow Surgeon (ASES) score were used to correlate functional outcome, tendon integrity, and muscle degeneration. RESULTS: 19 patients (17 males and 2 females) with a mean age of 57.5 years (range, 34 to 72) were included into the study at a mean follow-up of 50.3 months (range, 24 - 101). At final evaluation, 9 patients (47%) presented with intact RCR and 10 patients (53%) suffered a re-tear after revision repair. No progress of fatty infiltration was observed postoperatively in the group with intact RC, atrophy progressed in only 1 out of 9 patient (11%). Fatty infiltration progressed in 5/10 patients (50%) and RC atrophy increased in 2/10 patients (20%) within the re-tear group. CS (42.7 ± 17.7 preop, 65.2 ± 20.1 postop) and ASES (47.7 ± 17.2 preop, 75.4 ± 23.7 postop) improved significantly from pre- to postoperatively (p < 0.001). A positive correlation between fatty infiltration and RC integrity was detected (r = 0.77, p < 0.01). No correlation between clinical outcome and tendon integrity or RC atrophy was observed. CONCLUSION: Arthroscopic revision RCR leads to reliable functional outcomes even in case of a recurrent RC retear. An intact RCR maintains the preoperative state of fatty infiltration and muscle atrophy but does not lead to muscle regeneration. LEVEL OF EVIDENCE: Level IV; Therapeutic study.

Role of the Anterior Cruciate Ligament, Anterolateral Complex, and Lateral Meniscus Posterior Root in Anterolateral Rotatory Knee Instability: A Biomechanical Study.

BACKGROUND: Injuries to the anterior cruciate ligament (ACL), Kaplan fibers (KFs), anterolateral capsule/ligament (C/ALL), and lateral meniscus posterior root (LMPR) have been separately linked to anterolateral instability. PURPOSE: To investigate the contributions of the ACL, KFs, C/ALL, and LMPR to knee stability and to measure instabilities resulting from their injury. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen human knees were tested robotically to determine restraints of knee laxity at 0° to 90° of flexion. An 88-N anterior-posterior force (anterior and posterior tibial translation), 5-N·m internal-external rotation, and 8-N·m valgus-varus torque were imposed and intact kinematics recorded. The kinematics were replayed after sequentially cutting the structures (order varied) to calculate their contributions to stability. Another 10 knees were tested in a kinematics rig with optical tracking to measure instabilities after sequentially cutting the structures across 0° to 100° of flexion. One- and 2-way repeated-measures analyses of variance with Bonferroni correction were used to find significance (P < .05) for the robotic and kinematics tests. RESULTS: The ACL was the primary restraint for anterior tibial translation; other structures were insignificant (<10% contribution). The KFs and C/ALL resisted internal rotation, reaching 44% ± 23% (mean ± SD; P < .01) and 14% ± 13% (P < .05) at 90°. The LMPR resisted valgus but not internal rotation. Anterior tibial translation increased after ACL transection (P < .001) and after cutting the lateral structures from 70° to 100° (P < .05). Pivot-shift loading increased anterolateral rotational instability after ACL transection from 0° to 40° (P < .05) and further after cutting the lateral structures from 0° to 100° (P < .01). CONCLUSION: The anterolateral complex acts as a functional unit to provide rotatory stability. The ACL is the primary stabilizer for anterior tibial translation. The KFs are the most important internal rotation restraint >30° of flexion. Combined KFs + C/ALL injury substantially increased anterolateral rotational instability while isolated injury of either did not. LMPR deficiency did not cause significant instability with the ACL intact. CLINICAL RELEVANCE: This study is a comprehensive biomechanical sectioning investigation of the knee stability contributions of the ACL, anterolateral complex, and LMPR and the instability after their transection. The ACL is significant in controlling internal rotation only in extension. In flexion, the KFs are dominant, synergistic with the C/ALL. LMPR tear has an insignificant effect with the ACL intact.

Patient satisfaction, joint stability and return to sports following simple elbow dislocations: surgical versus non-surgical treatment.

PURPOSE: While conservative management is commonly promoted for simple elbow dislocations, the importance of primary surgical treatment in these injuries is still undetermined. The objective of this study was to report patient-reported outcome measures (PROMs), return to sports (RTS) and joint stability using ultrasound in patients following conservative or surgical treatment after simple elbow dislocation. METHODS: Patients with a minimum follow-up of 24 months after conservative (CT) or surgical treatment (ST) following simple elbow dislocation were included in this retrospective study. To evaluate patients' postoperative outcome and satisfaction, the Elbow Self-Assessment Score (ESAS) was used, and validated scores such as the Mayo elbow performance score (MEPS), the Quick Disability of Arm and Shoulder Score (Quick-DASH) and RTS were assessed. For objective assessment of residual joint instability, a standardized clinical examination as well as a dynamic ultrasound evaluation of the affected and the contralateral elbow was performed. RESULTS: Forty-four patients (26 women, 18 men) with an average age of 41.5 ± 15.3 years were available for follow-up survey (65.5 ± 30.4 months; range 26-123). 21 patients were treated conservatively and twenty-three patients received surgical treatment. CT and ST resulted in similar outcome with regard to ROM, ESAS (CT: 99.4 ± 1.5; ST: 99.8 ± 0.3), MEPS (CT: 97.3 ± 6.8 points; ST: 98.7 ± 3.3) and Quick-DASH (CT: 7.8 ± 10.4; ST: 6.3 ± 7.9) (n.s.). There was no difference in elbow stability and laxity measured by ultrasound between the study groups and compared to the healthy elbow (n.s.). Two patients of the CT group (10%) complained about persistent subjective elbow instability. RTS was faster after surgical compared to conservative treatment (p = 0.036). CONCLUSION: Both, conservative and surgical treatment results in high patient satisfaction and good-to-excellent functional outcome after simple elbow dislocation. Even though ultrasound evaluation showed no significant differences in joint gapping between groups, 10% of conservatively treated patients complained about severe subjective instability. Surgically treated patients returned faster to their preoperatively performed sports. Thus, primary surgical treatment may be beneficial for high demanding patients. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Clinical outcome and healing rate after meniscal bucket handle tear repair.

BACKGROUND: Reports combining patient-reported outcome measures, clinical evaluation, and radiographic assessment of postoperative healing after arthroscopic repair of bucket-handle meniscal tears (BHMT) are scarce. METHODS: Patients who underwent arthroscopic repair for acute traumatic BHMTs between October 2011 and March 2016 with a minimum follow-up of two years were included. Postoperative outcome scores comprised the International Knee Documentation Society Score (IKDC), Lysholm score, Tegner activity score (TAS), and visual analog scale (VAS) for pain. Clinical meniscal healing failure was assessed according to Barrett's criteria. Side-to-side difference in knee laxity was measured using KT-2000. Radiographic healing was assessed by 3-Tesla magnetic resonance imaging (MRI) and classified according to Henning's criteria at final follow-up. RESULTS: Forty patients with a mean age of 32.0 ± 11.5 years were available for follow-up after 51.8 ± 14.3 months. Revision surgery by means of arthroscopic partial meniscectomy was performed in four patients (10%) prior to the follow-up visit. The clinical healing rate was 83.3% at final follow-up. Mean IKDC score was 82.8 ± 13.8 and Lysholm score was 77.4 ± 24.8. Of all patients, 87.5% reached or exceeded the patient-acceptable symptomatic state (PASS) criteria for the IKDC score at final follow-up. The median TAS was 6 and VAS for pain was 0.46 ± 0.9. Side-to-side difference in knee laxity was higher in patients with concomitant ACL reconstruction (2.1 ± 2.7 mm) compared to isolated BHMTs (1.0 ± 2.0 mm). MR examination showed 69.4% healed, 25.0% partially healed, and 5.6% unhealed menisci. CONCLUSION: Patients who underwent repair for acute traumatic BHMTs achieved good to excellent clinical outcome along with a high rate of meniscal healing at a minimum follow-up of two years. Clinical and radiological healing rates were similarly satisfactory and most patients exceeded the PASS criteria for the IKDC score. Patients were able to reach a high postoperative activity level. LEVEL OF EVIDENCE: Case Series; IV.

Effect of Lateral Extra-articular Tenodesis on the Rate of Revision Anterior Cruciate Ligament Reconstruction in Elite Athletes.

BACKGROUND: There is growing evidence that anterolateral procedures can reduce the risk of rerupture in high-risk recreational athletes undergoing primary anterior cruciate ligament (ACL) reconstruction (ACLR). However, this effectiveness has never been evaluated in elite athletes. PURPOSE: The purpose of this study was to evaluate the effectiveness of lateral extra-articular tenodesis (LET) in reducing revision rates in primary ACLR in elite athletes. Additionally, this study evaluated whether LET had a greater effect when combined with ACLR utilizing a hamstring or patellar tendon graft. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A consecutive cohort of elite athletes with an isolated ACL tear undergoing autograft patellar or hamstring tendon reconstruction with or without Lemaire LET were analyzed between 2005 and 2018. A minimum 2-year follow-up was required. The association between the use of LET and ACL graft failure as defined by revision ACLR was evaluated with univariate and multivariate logistic regression models. RESULTS: A total of 455 elite athletes (83% men and overall age 22.5 ± 4.7 years) underwent primary ACLR with (n = 117) or without (n = 338) a LET procedure. Overall, 36 athletes (7.9%) experienced ACL graft failure, including 32 (9.5%) reconstructions without a LET and 4 (3.4%) with a LET. Utilization of LET during primary ACLR reduced the risk of graft failure by 2.8 times, with 16.5 athletes needing LET to prevent a single ACL graft failure. Multivariate models showed that LET significantly reduced the risk of graft rupture (relative risk = 0.325; P = .029) as compared with ACLR alone after controlling for sex and age at ACLR. Including graft type in the model did not significantly change the risk profile, and although a patellar tendon graft had a slightly lower risk of failure, this was not statistically significant (P = .466). CONCLUSION: The addition of LET reduced the risk of undergoing revision by 2.8 times in elite athletes undergoing primary ACLR. This risk reduction did not differ significantly between the patellar tendon and hamstring tendon autografts. With these results, status as an elite athlete should be included in the indications for a LET, as they are at increased risk for ACL graft failure.

High return to play rate following treatment of multiple-ligament knee injuries in 136 elite athletes.

PURPOSE: The purpose of the study is to assess return to play rate and timing of elite athletes treated for multi-ligament knee injuries with modern surgical techniques. METHODS: A retrospective review was performed of all professional or national/international level athletes treated for a multi-ligament knee injury by the senior author in the period from February 2001 to October 2019, with a minimum of 2-year follow-up. The study cohort consisted of 136 elite athletes who underwent surgery of two or more knee ligaments. Outcomes measures were return to play (RTP), defined as return to elite level sport, return to play time, and further surgical procedures. RESULTS: One hundred and twenty (88.2%) athletes returned to elite level sport at an average of 12.8 months from operation. In unicruciate injuries, ACL and PCL-based injuries had similar return to play rates (89.1% vs. 87.5% respectfully, n.s.) although mean RTP time was longer in those with PCL-based injuries (15.2 vs. 11.9 months, p < 0.01). Bicruciate injuries had longer RTP times compared to unicruciate injuries (mean RTP 16.0vs. 12.4 months, p < 0.05) but were able to return at a similar rate (83.3% vs. 88.9%, n.s.). Medial and lateral sided injuries had similar RTP rates (89.3% vs. 87.9%, n.s.) though lateral sided injuries took longer before returning to play (13.4 vs. 11.6 months, p < 0.05). Further surgery was required in 54 (39.9%) patients including 25 (18.4%) manipulations under anaesthesia. Four (2.9%) of the athletes underwent revision ligament surgery. CONCLUSION: Modern surgical techniques used in the treatment of multi-ligament knee injuries can lead to high return to play rates in elite athletes. LEVEL OF EVIDENCE: IV.

High incidence of superficial and deep medial collateral ligament injuries in 'isolated' anterior cruciate ligament ruptures: a long overlooked injury.

PURPOSE: In anterior cruciate ligament (ACL) injuries, concomitant damage to peripheral soft tissues is associated with increased rotatory instability of the knee. The purpose of this study was to investigate the incidence and patterns of medial collateral ligament complex injuries in patients with clinically 'isolated' ACL ruptures. METHODS: Patients who underwent ACL reconstruction for complete 'presumed isolated' ACL rupture between 2015 and 2019 were retrospectively included in this study. Patient's characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the grade and location of injuries to the superficial MCL (sMCL), dMCL and the posterior oblique ligament (POL) recorded. All patients were clinically assessed under anaesthesia with standard ligament laxity tests. RESULTS: Hundred patients with a mean age of 22.3 ± 4.9 years were included. The incidence of concomitant MCL complex injuries was 67%. sMCL injuries occurred in 62%, dMCL in 31% and POL in 11% with various injury patterns. A dMCL injury was significantly associated with MRI grade II sMCL injuries, medial meniscus 'ramp' lesions seen at surgery and bone oedema at the medial femoral condyle (MFC) adjacent to the dMCL attachment site (p < 0.01). Logistic regression analysis identified younger age (OR 1.2, p < 0.05), simultaneous sMCL injury (OR 6.75, p < 0.01) and the presence of bone oedema at the MFC adjacent to the dMCL attachment site (OR 5.54, p < 0.01) as predictive factors for a dMCL injury. CONCLUSION: The incidence of combined ACL and medial ligament complex injuries is high. Lesions of the dMCL were associated with ramp lesions, MFC bone oedema close to the dMCL attachment, and sMCL injury. Missed AMRI is a risk factor for ACL graft failure from overload and, hence, oedema in the MCL (especially dMCL) demands careful assessment for AMRI, even in the knee lacking excess valgus laxity. This study provides information about specific MCL injury patterns including the dMCL in ACL ruptures and will allow surgeons to initiate individualised treatment. LEVEL OF EVIDENCE: III.

Anterolateral complex injuries occur in the majority of 'isolated' anterior cruciate ligament ruptures.

PURPOSE: The anterolateral soft tissue envelope of the knee is frequently injured at the time of ACL rupture. This study aims to investigate the MRI injury patterns to the Anterolateral complex and their associations in patients with acute 'isolated ligament' ACL ruptures. METHODS: Professional athletes who underwent ACL reconstruction for complete ACL rupture between 2015 and 2019 were included in this study. Patients' characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the injuries to respective structures of the Anterolateral complex and their associations were recorded. RESULTS: Anterolateral complex injuries were noted in 63% of cases. The majority of injuries were to Kaplan Fibre (39% isolated injury and 19% combined with Anterolateral ligament injury). There was a very low incidence of isolated Anterolateral ligament injuries (2%). Kaplan Fibre injuries are associated with the presence of lateral femoral condyle bone oedema, and injuries to the superficial MCL, deep MCL, and ramp lesions. High grade pivot shift test was not associated with the presence of Kaplan Fibre or Anterolateral ligament injuries. Patients with an intact Anterolateral complex sustained injury to other knee structures (13% to medial ligament complex, 14% to medial meniscus, and 16% to lateral meniscus). CONCLUSION: There is a high incidence of concomitant Anterolateral complex injuries in combination with ACL ruptures, with Kaplan Fibre (and therefore the deep capsulo-osseous layer of the iliotibial band) being the most commonly injured structure. Anterolateral ligament injuries occur much less frequently. These findings reinforce the importance of considering the presence of, and if necessary, treating injuries to structures other than the ACL, as a truly isolated ACL injury is rare.

Medial meniscal ramp lesions in ACL-injured elite athletes are strongly associated with medial collateral ligament injuries and medial tibial bone bruising on MRI.

PURPOSE: Medial menisco-capsular separations (ramp lesions) are typically found in association with anterior cruciate ligament (ACL) deficiency. They are frequently missed preoperatively due to low MRI sensitivity. The purpose of this article was to describe demographic and anatomical risk factors for ramp lesions, and to identify concomitant lesions and define their characteristics to improve diagnosis of ramp lesions on MRI. METHODS: Patients who underwent anterior cruciate ligament (ACL) reconstruction between September 2015 and April 2019 were included in this study. The presence/absence of ramp lesions was recorded in preoperative MRIs and at surgery. Patients' characteristics and clinical findings, concomitant injuries on MRI and the posterior tibial slope were evaluated. RESULTS: One hundred patients (80 male, 20 female) with a mean age of 22.3 ± 4.9 years met the inclusion criteria. The incidence of ramp lesions diagnosed at surgery was 16%. Ramp lesions were strongly associated with injuries to the deep MCL (dMCL, p < 0.01), the superficial medial collateral ligament (sMCL, p < 0.01), and a small medial-lateral tibial slope asymmetry (p < 0.05). There was also good correlation between ramp lesions and bone oedema in the posterior medial tibia plateau (MTP, p < 0.05) and medial femoral condyle (MFC, p < 0.05). A dMCL injury, a smaller differential medial-lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. MRI sensitivity was 62.5% and the specificity was 84.5%. CONCLUSION: The presence on MRI of sMCL and/or dMCL lesions, bone oedema in the posterior MTP and MFC, and a smaller differential medial-lateral tibial slope than usual are highly associated with ramp lesions visible on MRI. Additionally, a dMCL injury, a flatter lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. Knowledge of the risk factors and secondary injury signs associated with ramp lesions facilitate the diagnosis of a ramp lesion preoperatively and should raise surgeons' suspicion of this important lesion. LEVEL OF EVIDENCE: Diagnostic study, Level III.

Anterior cruciate ligament autograft maturation on sequential postoperative MRI is not correlated with clinical outcome and anterior knee stability.

PURPOSE: Magnetic resonance imaging (MRI) signal intensity is correlated to structural postoperative changes of the anterior cruciate ligament (ACL) autograft. The purpose of this study was to investigate the ACL autograft maturation process via MRI over 2 years postoperatively, compare it to a native ACL signal and correlate the results with clinical outcome, return to preinjury sports levels, and knee laxity measurements. METHODS: ACL autograft signal intensity was measured in 17 male patients (age, 28.3 ± 7.0 years) who underwent ACL reconstruction with hamstring autograft at 6 weeks, 3-, 6-, 12-, and 24 months postoperatively by 3 Tesla MRI. Controls with an intact ACL served as control group (22 males, 8 females; age, 26.7 ± 6.8 years). An ACL/PCL ratio (APR) and ACL/muscle ratio (AMR) was calculated to normalize signals to soft tissue signal. APR and AMR were compared across time and to native ACL signal. Clinical outcome scores (IKDC, Lysholm), return to preinjury sports levels (Tegner activity scale), and knee laxity measurement (KT-1000) were obtained and correlated to APR and AMR at the respective time points. RESULTS: The APR and AMR of the ACL graft changed significantly from the lowest values at 6 weeks to reach the highest intensity after 6 months (p < 0.001). Then, the APR and AMR were significantly different from a native ACL 6 months after surgery (p < 0.01) but approached the APR and AMR of the native ACL at 1- and 2 years after surgery (p < 0.05). The APR changed significantly during the first 2 years postoperatively in the proximal (p < 0.001), mid-substance (p < 0.001), and distal (p < 0.01) intraarticular portion of the ACL autograft. A hypo-intense ACL MRI signal was associated with return to the preinjury sports level (p < 0.05). No correlation was found between ACL MRI graft signal and clinical outcome scores or KT-1000 measurements. CONCLUSION: ACL grafts undergo a continuous maturation process in the first 2 years after surgery. The ACL graft signals became hyper-intense 6 months postoperatively and approximated the signal of a native intact ACL at 12- and 24 months. Patients with a hypo-intense ACL graft signal at 2 years follow-up were more likely to return to preinjury sports levels. The results of the present study provide a template for monitoring the normal ACL maturation process via MRI in case of prolonged clinical symptoms. However, subjective outcome and clinical examination of knee laxity remain important to assess the treatment success and to allow to return to sports. LEVEL OF EVIDENCE: III.

Factors affecting return to play and graft re-rupture after primary ACL reconstruction in professional footballers.

PURPOSE: Modern ACL reconstruction (ACL-R) techniques have led to improved outcomes in professional footballers. The aim of this study was to identify and assess patient, surgical and post-operative factors that affected rates and time to return to play (RTP) as well as ACL re-rupture rates. METHODS: A retrospective review of consecutive ACL-R undertaken in professional footballers between 2005 and 2018. RESULTS: Two-hundred and thirty-two knees in 215 professional footballers (17 bilateral) were included. 205 (88.9%) were male and average age at surgery was 23.3 ± 4.4 years. Two-hundred and twenty-two (96.1%) returned to professional football, with 209 (90.1%) returning to the same or higher Tegner level. Subgroup analysis revealed three factors that independently affected RTP rate: (1) Players under 25 years had a higher rate of RTP (99.3% vs 90.2%. p = 0.001); (2) a subsequent operation prior to RTP decreased RTP rate from 98.2 to 89.7% (p = 0.009).; (3) undergoing meniscal surgery at ACL-R decreased RTP rate (p = 0.002). The mean time to RTP from surgery was 10.5 ± 3.6 months. Factors found to increase RTP time included age under 25 (11.0 vs 9.7 months, p = 0.005), recurrent effusions (11.4 vs 10.2 months, p = 0.035), and medial meniscal repair at ACL-R compared to meniscectomy (12.5 vs 9.6 months, p = 0.022). The surgical technique varied over the study period in relation to graft type, femoral tunnel position and addition of lateral extra-articular tenodesis (LET). Overall, the re-rupture rate was 8.2% at 2 years. Patella tendon autograft in an anteromedial bundle femoral tunnel position with addition of LET has the lowest re-rupture rate (2.0%). CONCLUSION: Primary ACL-R in professional footballers yields high rates of RTP (96.1%), with 90.1% at the same level or higher, at a mean 10.5 months. Patients under 25 years not only had a significantly higher RTP rate, but also had a lengthier period of rehabilitation. LEVEL OF EVIDENCE: Level IV.

High Rate of Initially Overlooked Kaplan Fiber Complex Injuries in Patients With Isolated Anterior Cruciate Ligament Injury.

BACKGROUND: Injuries to the Kaplan fiber complex (KFC) are not routinely assessed for in the anterior cruciate ligament (ACL)-deficient knee during preoperative magnetic resonance imaging (MRI). As injuries to the KFC lead to anterolateral rotatory instability (ALRI) in the ACL-deficient knee, preoperative detection of these injuries on MRI scans may help surgeons to individualize treatment and improve outcomes, as well as to reduce failure rates. PURPOSE: To retrospectively determine the rate of initially overlooked KFC injuries on routine MRI in knees with isolated primary ACL deficiency. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent isolated ACL reconstruction between August 2013 and December 2019 were identified. No patient had had Kaplan fiber (KF) injury identified on the initial reading of the MRI scan or at the time of surgery. Preoperative knee MRI scans (minimum 1.5 T) were reviewed and injuries to the proximal and distal KFs were recorded by 3 independent reviewers. KF length and distance to nearby anatomic landmarks (the lateral joint line and the lateral femoral epicondyle) were measured. Additional radiological findings, including bleeding, lateral femoral notch sign, and bone marrow edema (BME), were identified to detect correlations with KFC injury. RESULTS: The intact KFC could reliably be identified by all 3 reviewers (85.9% agreement; Kappa, 0.716). Also, 53% to 56% of the patients with initially diagnosed isolated ACL ruptures showed initially overlooked injuries to the KFC. Injuries to the distal KFs were more frequent (48.1%, 53.8%, and 43.3% by the first, second, and third reviewers, respectively) than injuries to the proximal KFs (35.6%, 47.1%, and 45.2% by the first, second, and third reviewers, respectively). Bleeding in the lateral supracondylar region was associated with KFC injuries (P = .023). Additionally, there was a positive correlation between distal KF injuries and lateral tibial plateau BME (P = .035), but no associations were found with the lateral femoral notch sign or other patterns of BME, including pivot-shift BME. CONCLUSION: KF integrity and injury can be reliably detected on routine knee MRI scans. Also, 53% to 56% of the patients presenting with initially diagnosed isolated ACL ruptures had concomitant injuries to the KFC. This is of clinical relevance, as ACL injuries diagnosed by current routine MRI examination protocols may come with a high number of occult or hidden KFC injuries. As injuries to the KFC contribute to persistent ALRI, which may influence ACL graft failure or reoperation rates, significant improvements in preoperative diagnostic imaging are required to determine the exact injury pattern and to assist in surgical decision making.

Knee Joint Line Obliquity Causes Tibiofemoral Subluxation That Alters Contact Areas and Meniscal Loading.

BACKGROUND: Little scientific evidence is available regarding the effect of knee joint line obliquity (JLO) before and after coronal realignment osteotomy. HYPOTHESES: Higher JLO would lead to abnormal relative position of the femur on the tibia, a shift of the joint contact areas, and elevated joint contact pressures. STUDY DESIGN: Descriptive laboratory study. METHODS: 10 fresh-frozen human cadaveric knees (age, 59 ± 5 years) were axially loaded to 1500 N in a materials testing machine with the joint line tilted 0°, 4°, 8°, and 12° varus ("downhill" medially) and valgus, at 0° and 20° of knee flexion. The mechanical compression axis was aligned to the center of the tibial plateau. Contact pressure and contact area were recorded by pressure sensors inserted between the tibia and femur below the menisci. Changes in relative femoral and tibial position in the coronal plane were obtained by an optical tracking system. RESULTS: Both medial and lateral JLO caused significant tibiofemoral subluxation and pressure distribution changes. Medial (varus) JLO caused the femur to subluxate medially down the coronal slope of the tibial plateau, and vice versa for lateral (valgus) downslopes (P < .01), giving a 6-mm range of subluxation. The areas of peak pressure moved 12 mm and 8 mm across the medial and lateral condyles, onto the downhill meniscus and the "uphill" tibial spine. Changes in JLO had only small effects on maximum contact pressures. CONCLUSION: A 4° change of JLO during load bearing caused significant mediolateral tibiofemoral subluxation. The femur slid down the slope of the tibial plateau to abut the tibial eminence and also to rest on the downhill meniscus. This caused large movements of the tibiofemoral contact pressures across each compartment. CLINICAL RELEVANCE: These results provide important information for understanding the consequences of creating coronal JLO and for clinical practice in terms of osteotomy planning regarding the effect on JLO. This information provides guidance regarding the choice of single- or double-level osteotomy. Excessive JLO alteration may cause abnormal tibiofemoral joint articulation and chondral or meniscal loading.

An Anterior Cruciate Ligament In Vitro Rupture Model Based on Clinical Imaging.

BACKGROUND: Biomechanical studies on anterior cruciate ligament (ACL) injuries and reconstructions are based on ACL transection instead of realistic injury trauma. PURPOSE: To replicate an ACL injury in vitro and compare the laxity that occurs with that after an isolated ACL transection injury before and after ACL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Nine paired knees were ACL injured or ACL transected. For ACL injury, knees were mounted in a rig that imposed tibial anterior translation at 1000 mm/min to rupture the ACL at 22.5° of flexion, 5° of internal rotation, and 710 N of joint compressive force, replicating data published on clinical bone bruise locations. In contralateral knees, the ACL was transected arthroscopically at midsubstance. Both groups had ACL reconstruction with bone-patellar tendon-bone graft. Native, ACL-deficient, and reconstructed knee laxities were measured in a kinematics rig from 0° to 100° of flexion with optical tracking: anterior tibial translation (ATT), internal rotation (IR), anterolateral (ATT + IR), and pivot shift (IR + valgus). RESULTS: The ACL ruptured at 26 ± 5 mm of ATT and 1550 ± 620 N of force (mean ± SD) with an audible spring-back tibiofemoral impact with 5o of valgus. ACL injury and transection increased ATT (P < .001). ACL injury caused greater ATT than ACL transection by 1.4 mm (range, 0.4-2.2 mm; P = .033). IR increased significantly in ACL-injured knees between 0° and 30° of flexion and in ACL transection knees from 0° to 20° of flexion. ATT during the ATT + IR maneuver was increased by ACL injury between 0° and 80° and after ACL transection between 0° and 60°. Residual laxity persisted after ACL reconstruction from 0° to 40° after ACL injury and from 0° to 20° in the ACL transection knees. ACL deficiency increased ATT and IR in the pivot-shift test (P < .001). The ATT in the pivot-shift increased significantly at 0° to 20° after ACL transection and 0° to 50° after ACL injury, and this persisted across 0° to 20° and 0° to 40° after ACL reconstruction. CONCLUSION: This study developed an ACL injury model in vitro that replicated clinical ACL injury as evidenced by bone bruise patterns. ACL injury caused larger increases of laxity than ACL transection, likely because of damage to adjacent tissues; these differences often persisted after ACL reconstruction. CLINICAL RELEVANCE: This in vitro model created more realistic ACL injuries than surgical transection, facilitating future evaluation of ACL reconstruction techniques.