Underappreciated Factors to Consider in Revision Anterior Cruciate Ligament Reconstruction: A Current Concepts Review

Two-stage revision anterior cruciate ligament reconstruction reduces failure risk but leads to lesser clinical outcomes than single-stage revision after primary anterior cruciate ligament graft failure: a retrospective cohort study

BACKGROUND

There are no studies that compare the outcomes and complications of single-versus two-stage revision anterior cruciate ligament reconstruction (ACLR) after primary ACLR failure. This purpose of this study is to examine clinical and functional outcomes and complications associated with single and two-stage revision ACLR after primary ACLR failure.

METHODS

All patients who underwent single or two-stage revision ACLR after primary ACLR failure between 2012 and 2021 with a minimum of a 2 year follow-up were included. Patients were excluded if they were not treated at our single academic institution, had inadequate follow-up, or had incomplete medical records. Revision intraoperative data, concomitant injuries, and complications were collected by chart review. Return to sport, numerical pain rating scale (NPRS) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Veteran Rands 12-item health survey (VR-12 scores) were collected.

RESULTS

The final analysis included 176 patients. A total of 147 (83.5%) had a single-stage revision ACLR (87 male, 60 female), and 29 (16.5%) had a two-stage revision ACLR (13 male, 16 female). Two-stage revision ACLR was significantly associated with anterior knee pain [odds ratio (OR) 4.36; 95% confidence interval (CI) 1.5 to 12.65; P = 0.007] but with lower failure rates (OR 0.12, 95% CI 0.02 to 0.9; P = 0.04). On multivariate analysis, a two-stage revision ACLR reduced the risk of graft failure by 85% (OR 0.15; 95% CI 0.02 to 1.17; P = 0.07). Two-stage revision ACLR was significantly associated with a lower KOOS pain score (OR -11.7; 95% CI -22.35 to -1.04; P = 0.031), KOOS symptoms score (OR -17.11; 95% CI -28.85 to -5.36; P = 0.004), KOOS Activities of Daily Living (ADL) score (OR -11.15; 95% CI -21.71 to -0.59; P = 0.039) and Veterans RAND 12-Item Health Survey (VR-12) physical component score (OR -9.99; 95% CI -15.77 to -4.22; P = 0.001).

CONCLUSIONS

The clinical outcomes and subjective patient scores significantly differed between the single-stage and two-stage revision ACLR after primary ACLR failure. Patients with a two-stage revision ACLR had a significantly reduced risk of revision graft failure but higher rates of postoperative anterior knee pain, lower pain scores, and lesser knee functional scores than single-stage revision patients.

STUDY DESIGN

Retrospective cohort study; level of evidence, 3.

Revision Anterior Cruciate Ligament Reconstruction in Combination With Meniscal and Osteochondral Allograft Transplantation for Complex Knee Injury

Revision anterior cruciate ligament reconstruction (ACLR) may present a challenge as a result of several factors, including malpositioned bone tunnels, tunnel osteolysis, and the presence of previous hardware. In addition, concomitant pathology, specifically meniscal and cartilaginous injuries, may be present and should be addressed to minimize the risk of re-rupture. Revision ACLR and treatment of accompanying injuries can be performed either as a 1-stage or 2-stage procedure, yet the latter may increase surgical risk for the patient and extend recovery time. The over-the-top technique serves as a good option for revision ACLR and can be performed with careful consideration of patient-specific anatomy and with proper surgical planning. Therefore, this Technical Note aims to present our 1-stage surgical technique for revision ACLR using over-the-top technique with an Achilles tendon allograft, along with concomitant treatment for meniscal deficiency and a medial femoral condyle chondral defect using meniscal and osteochondral allografts, respectively.

A Novel Machine Learning Model to Predict Revision ACL Reconstruction Failure in the MARS Cohort

Background

As machine learning becomes increasingly utilized in orthopaedic clinical research, the application of machine learning methodology to cohort data from the Multicenter ACL Revision Study (MARS) presents a valuable opportunity to translate data into patient-specific insights.

Purpose

To apply novel machine learning methodology to MARS cohort data to determine a predictive model of revision anterior cruciate ligament reconstruction (rACLR) graft failure and features most predictive of failure.

Study Design

Cohort study; Level of evidence, 3.

Methods

The authors prospectively recruited patients undergoing rACLR from the MARS cohort and obtained preoperative radiographs, surgeon-reported intraoperative findings, and 2- and 6-year follow-up data on patient-reported outcomes, additional surgeries, and graft failure. Machine learning models including logistic regression (LR), XGBoost, gradient boosting (GB), random forest (RF), and a validated ensemble algorithm (AutoPrognosis) were built to predict graft failure by 6 years postoperatively. Validated performance metrics and feature importance measures were used to evaluate model performance.

Results

The cohort included 960 patients who completed 6-year follow-up, with 5.7% (n = 55) experiencing graft failure. AutoPrognosis demonstrated the highest discriminative power (model area under the receiver operating characteristic curve: AutoPrognosis, 0.703; RF, 0.618; GB, 0.660; XGBoost, 0.680; LR, 0.592), with well-calibrated scores (model Brier score: AutoPrognosis, 0.053; RF, 0.054; GB, 0.057; XGBoost, 0.058; LR, 0.111). The most important features for AutoPrognosis model performance were prior compromised femoral and tibial tunnels (placement and size) and allograft graft type used in current rACLR.

Conclusion

The present study demonstrated the ability of the novel AutoPrognosis machine learning model to best predict the risk of graft failure in patients undergoing rACLR at 6 years postoperatively with moderate predictive ability. Femoral and tibial tunnel size and position in prior ACLR and allograft use in current rACLR were all risk factors for rACLR failure in the context of the AutoPrognosis model. This study describes a unique model that can be externally validated with larger data sets and contribute toward the creation of a robust rACLR bedside risk calculator in future studies.

Registration

NCT00625885 (ClinicalTrials.gov identifier).

Whipstitch and Locking Stitch Show Equivalent Elongation and Load to Failure Across 3 Suture Systems in a Biomechanical Model of Quadriceps Tendon Grafts for Anterior Cruciate Ligament Reconstruction

Purpose

To compare the biomechanical properties of quadriceps tendon (QT) graft stitch methods using 3 different suture systems for anterior cruciate ligament reconstruction.

Methods

A total of 48 QTs were harvested from cadaveric knee specimens (age: 73 ± 7 years; range, 66-86 years). Samples were randomly divided into 3 groups where different suture needle systems were used to create 2 stitch methods: whipstitch (WS) and locking stitch (LS). Surgeons performed each technique to 5 stitches, each 0.5 cm apart. Stitching time was recorded. Samples were preconditioned and then underwent cyclic loading, followed by load to failure. Stiffness (N/mm), ultimate failure load (N), peak-to-peak displacement (mm), elongation (mm), and failure displacement (mm) were recorded.

Results

WS and LS were equivalent across stiffness, ultimate load, and peak-to-peak displacement within groups 2 and 3. In group 1, the LS was stiffer than the WS, but the WS achieved a higher ultimate load. For all groups, the LS achieved lower elongation and failure displacement than the WS, with significant differences in groups 1 and 2. Within each stitching method, equivalence was determined for total elongation and ultimate failure load for all 3 suture system groups. For WS samples, group 1 all failed from suture breakage, and both groups 2 and 3 had instances of failure from suture pull-through. All LS samples failed from suture breakage.

Conclusions

Both LS and WS provide adequate mechanical properties in each of the 3 suture systems. Differences in performance do exist; however, each method shows equivalent total elongation and ultimate failure load for all 3 suture systems. LS may be preferred over WS due to lower mean elongation and failure displacement.

Clinical Relevance

There is an increased use of QT grafts in for anterior cruciate ligament reconstruction. However, there have been a limited number of studies comparing various stitching methods and optimizing techniques for QT graft fixation. This study may provide important information to surgeons about which suture techniques have better biomechanical profiles.

Medial Meniscectomy at the Time of ACL Reconstruction Is Associated With Postoperative Anterior Tibial Translation: A Retrospective Analysis

Background

Medial meniscal pathology and management have not been associated with postoperative anterior tibial translation (ATT) after anterior cruciate ligament reconstruction (ACLR).

Purpose

The purpose of this study was to evaluate the role of medial meniscal injury and treatment on pre- and postoperative ATT in the setting of primary ACLR. More specifically, the association between repairable medial meniscal tears, medial meniscectomy, and postoperative ATT, along with rates of revision surgery, was examined.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective review was performed for patients who underwent ACLR between January 1, 2010 and December 31, 2015 at a single center. Descriptive data were obtained from an institutional database for a total of 396 patients included in this study and followed for 1 year postoperatively. Statistical analysis was performed to examine associations of meniscal treatment with postoperative ATT measurements made by KT-1000 arthrometer.

Results

A total of 243 patients underwent isolated ACLR with autograft, 72 patients underwent autograft ACLR and partial medial meniscectomy (MMx) (ACLR + MMx), and 81 patients underwent autograft ACLR and medial meniscal repair (MMR) (ACLR + MMR). Patients with ACLR + MMx had higher mean age and body mass index compared with patients in the other groups. Patients who underwent ACLR + MMx had greater postoperative side-to-side ATT compared with patients undergoing ACLR (1.55 mm vs 1.07 mm; P = .04) or patients undergoing ACLR + MMR (1.55 mm vs 1.01 mm; P = .03). The ACLR + MMx group was less likely to have symmetric (<3-mm side-to-side difference) postoperative ATT compared with the ACLR group (85% vs 93%; P = .03). There was no difference in postoperative ATT between ACLR and ACLR + MMR. Postoperative return to the operating room was greater in the ACLR + MRR group compared with the ACLR + MMx group (21.9% vs 8.2%; P = .05).

Conclusion

MMx at the time of ACLR led to higher postoperative ATT compared with isolated ACLR or ACLR + MMR.

Comparison of Side-to-Side Difference in Posterior Tibial Slope in Knees With Acute Versus Chronic Anterior Cruciate Ligament Deficiency

Background

The posterior tibial slope (PTS) is an important feature in knee joint biomechanics and indicates anterior-posterior knee stability. Increased PTS is a known risk factor for both primary anterior cruciate ligament (ACL) rupture and postreconstruction rerupture.

Purpose

To investigate the effect of long-term exposure to ACL deficiency on the PTS and the sagittal anatomy of the proximal tibia.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 44 patients (38 men, 6 women) with a history of knee injury and ACL rupture confirmed by magnetic resonance imaging and physical examination were included in this study. Patients were divided into those with chronic ACL deficiency (group 1: injured ≥5 years prior; n = 22) and acute ACL deficiency (group 2: injured <1 year prior; n = 22). The medial and lateral tibial plateau PTS and anterior tibial translation were measured on monopodal weightbearing knee radiographs at 20° of flexion. The mechanical tibiofemoral angle (MTFA) and the medial proximal tibial angle (MPTA) were measured using an orthoroentgenogram. The side-to-side difference between the affected and unaffected knees was also calculated for all measurements.

Results

The mean duration of exposure to ACL deficiency was 7.6 years (range, 5-15 years) in group 1 and 4.4 months (range, 1-11 months) in group 2. Regarding the side-to-side differences in angular measurements, a higher medial PTS (affected vs unaffected: 12.4° vs 10.1°; P = .007), higher lateral PTS (11° vs 8.9°; P = .011), and increased varus alignment on both the MTFA (4.3° vs 2.4°; P = .036) and the MPTA (84.9° vs 86.3°; P = .033) were found in group 1, while no significant differences in angular measurements were found in group 2. Compared with group 2, patients in group 1 had a significantly higher side-to-side difference in the medial PTS (2.3° vs 0.1°; P = .0001), lateral PTS (2.1° vs 0.4°; P = .0001), and MPTA (1.4° vs 0.1°; P = .002).

Conclusion

This study showed that the affected knees of patients with chronic ACL deficiency (≥5 years) had higher medial and lateral PTS compared with the unaffected contralateral knees. Therefore, when planning ACL reconstruction for patients with a history of long-term ACL deficiency, it is crucial to measure the preoperative PTS accurately.

Evaluation of Failed ACL Reconstruction: An Updated Review

Failure rates among primary Anterior Cruciate Ligament Reconstruction (ACLR) range from 3.2% to 11.1%. Recently, there has been increased focus on surgical and anatomic considerations which predispose patients to failure, including excessive posterior tibial slope (PTS), unaddressed high-grade pivot shift, and improper tunnel placement. The purpose of this review was to provide a current summary and analysis of the literature regarding patient-related and technical factors surrounding revision ACLR, rehabilitation considerations, overall outcomes and return to sport (RTS) for patients who undergo revision ACLR. There is a convincingly higher re-tear and revision rate in patients who undergo ACLR with allograft than autograft, especially amongst the young, athletic population. Unrecognized Posterior Cruciate Ligament (PLC) injury is a common cause of ACLR failure and current literature suggests concurrent operative management of high-grade PLC injuries. Given the high rates of revision surgery in young active patients who return to pivoting sports, the authors recommend strong consideration of a combined ACLR + Anterolateral Ligament (ALL) or Lateral extra-articular tenodesis (LET) procedure in this population. Excessive PTS has been identified as an independent risk factor for ACL graft failure. Careful consideration of patient-specific factors such as age and activity level may influence the success of ACL reconstruction. Additional technical considerations including graft choice and fixation method, tunnel position, evaluation of concomitant posterolateral corner and high-grade pivot shift injuries, and the role of excessive posterior tibial slope may play a significant role in preventing failure.

Sulcus-Deepening Trochleoplasty for High-Grade Trochlear Dysplasia: Demystifying the Procedure-a Review of the Current Literature

PURPOSE OF REVIEW

The most common and biomechanically influential pathoanatomic risk factor for recurrent patellofemoral instability is trochlear dysplasia. Sulcus-deepening trochleoplasty is a procedure developed to address high-grade trochlear dysplasia in the setting of patellofemoral instability. The purpose of this paper is to outline the current classification and surgical management of trochlear dysplasia as well as to review the current literature on the clinical outcomes and complications of sulcus-deepening trochleoplasty.

RECENT FINDINGS

This review outlines the most recent literature reporting evidence behind the decision-making to perform a trochleoplasty in the setting of patellofemoral instability and high-grade trochlear dysplasia. Critical parameters include grade of trochlear dysplasia, severity of symptoms, pertinent physical examination findings, surgical techniques, modifications for skeletally immature patients, and considerations for the revision setting. Historic studies have elicited concerns regarding high reported complication rates for trochleoplasty; however, recent studies consistently report good clinical outcomes and acceptable complication rates, similar to those of other patellar stabilizing procedures. The addition of a trochleoplasty in patients with high-grade dysplasia results in a lower re-dislocation rate, significant improvements in patient-reported outcome measures (PROMs) as well as high levels of patient satisfaction and return to sport. The use of sulcus-deepening trochleoplasty for the treatment of high-grade dysplasia and recurrent patellofemoral instability is a well-established technique with good outcomes and an acceptable complication profile. In patients with high-grade dysplasia, trochleoplasty results in lower re-dislocation rates, high patient satisfaction scores, and good clinical and functional outcomes. An understanding of trochleoplasty and its indications should be in the armamentarium of surgeons treating patellofemoral instability.

Anatomic anterior cruciate ligament reconstruction: Freddie Fu's paradigm

Anterior cruciate ligament (ACL) reconstruction techniques have evolved over the past four decades. There is evidence that non-anatomic reconstruction techniques, such as traditional transtibial drilling, fail to recreate the native anatomy of the ACL, which can lead to increased rotatory knee instability, revision risk, and post-traumatic osteoarthritis. Anatomic ACL reconstruction has emerged as the gold standard, with the goal of restoring the patient's native anatomy and knee kinematics. This review will summarise the relevant anatomy, modern anatomic ACL reconstruction techniques, and literature supporting anatomic ACL reconstruction as the new paradigm. LEVEL OF EVIDENCE: Level V, review article.

Revision Anterior Cruciate Ligament, Lateral Collateral Ligament Reconstruction, and Osteochondral Allograft Transplantation for Complex Knee Instability

Anterior cruciate ligament (ACL) injuries rarely occur as an isolated event and often include associated meniscal, subchondral bone, and collateral ligament injuries. Concomitant pathology frequently complicates primary and revision ACL reconstruction and must be addressed to ensure comprehensive diagnosis and treatment. In this Technical Note, we describe our method for treatment of complex knee instability following multiple failed ACL reconstruction using a multiligament reconstruction technique with an osteochondral allograft transplantation to the lateral femoral condyle. This comprehensive repair technique restores the anatomic load bearing forces of the cruciate and collateral ligaments and promotes biological repair through incorporation of cartilage resurfacing to ultimately achieve optimal kinematics of the knee joint.

Anterior Closing-Wedge High Tibial Slope-Correcting Osteotomy Using Patient-Specific Preoperative Planning Software for Failed Anterior Cruciate Ligament Reconstruction

Failure of anterior cruciate ligament reconstruction (ACLR) remains a challenging problem. Recently, the effect of increased posterior tibial slope has been identified as a risk factor for ACLR failure. In cases with increased posterior tibial slope, an anterior closing wedge, slope-correcting high tibial osteotomy can be used as a robust adjunct to revision ACLR. In this Technical Note, we demonstrate our preferred method for isolated sagittal plane correction following multiple failed ACLRs with an anterior closing-wedge high tibial osteotomy technique using 3-dimensional patient-specific instrumentation. Through correction of the angular deformity and restoration of the defined sagittal slope via the use of advanced 3-dimensional patient-specific instrumentation, this technique fosters an accurate, favorable mechanical environment to prevent recurrent instability of the knee joint.

Steep lateral tibial slope measured on magnetic resonance imaging is the best radiological predictor of anterior cruciate ligament reconstruction failure

PURPOSE

To identify the radiological predictive risk factors for anterior cruciate ligament reconstruction (ACLR) failure, compare the diagnostic accuracies of different parameters of conventional radiographs and magnetic resonance imaging (MRI), and determine the cutoff values for patients at higher risk.

METHODS

Twenty-eight patients who were diagnosed as ACLR failure via MRI or arthroscopic examination were included in the study group. They were matched to 56 patients who underwent primary ACLR with the same surgical technique and without graft failure at the minimum 24-month follow-up by age, sex, and body mass index. On true lateral whole-leg radiographs, the posterior tibial slope (PTS) referenced to the tibial mechanical axis (PTS-mechanical), PTS referenced to the tibial proximal anatomical axis (PTS-anatomical), and anterior tibial translation (ATT) were measured. On the sagittal slices of MRI, the medial tibial slope (MTS), medial tibial plateau (MTP) subluxation (MTPsublx), lateral tibial slope (LTS), and lateral tibial plateau (LTP) subluxation (LTPsublx) were obtained. Receiver operator characteristic (ROC) curves were constructed to compare the diagnostic performance and determine the cutoff values of different radiological parameters.

RESULTS

The study group demonstrated higher values of PTS-mechanical (10.7° ± 2.9° vs 8.7° ± 1.9°, p = 0.003), PTS-anatomical (13.2° ± 2.8° vs 10.5° ± 2.5°, p < 0.001), ATT (10.7 ± 3.3 mm vs 8.9 ± 2.2 mm, p = 0.014), LTS (9.4° ± 2.1° vs 5.5° ± 2.5°, p < 0.001), and LTPsublx (8.2 ± 2.8 mm vs 6.8 ± 1.9 mm, p = 0.009) as compared with the control group. The area under the ROC curve of LTS was significantly larger than that of PTS-mechanical (p = 0.006) and PTS-anatomical (p = 0.020). Based on the maximum Youden indexes, the cutoff values of PTS-mechanical, PTS-anatomical, and LTS were 10.1° (sensitivity, 64.3%; specificity, 78.6%), 12.0° (sensitivity, 71.4%; specificity, 71.4%), and 7.7° (sensitivity, 85.7%; specificity, 80.4%), respectively.

CONCLUSION

Due to the morphological asymmetry of the MTP and LTP, steep LTS measured on MRI is the best radiological predictor of ACLR failure. Detailed measurement of the LTS on MRI is recommended to evaluate the risk of ACLR failure prior to the surgery.

LEVEL OF EVIDENCE

III.

Risk of reoperation after primary anterior cruciate ligament reconstruction in children and adolescents

OBJECTIVE

To examine the incidence and risk factors of any-cause reoperation after primary ACLR in children and adolescents.

DESIGN

Retrospective Cohort.

SETTING

Electronic medical records from a large tertiary care, single institution integrated healthcare delivery system.

PATIENTS

Patients were under the age of 18 years and had anterior cruciate ligament reconstruction. They were excluded if they had a multi-ligamentous knee injury or <1 year follow-up.

INTERVENTIONS

Patients were further identified to have undergone a subsequent knee operation ipsilaterally or contralateral ACLR.

MAIN OUTCOME MEASURES

The rate of any-cause reoperation was our primary outcome measure.

RESULTS

The median age was 16. There were 208 females (53.9%) and 178 males (46.1%) included. The median follow-up was 25 months with a minimum of 12 months (interquartile range: 16.0, 46.0). The rate of any-cause reoperation was 34.7%. There was no statistically significant difference between those who underwent reoperation versus those who did not undergo reoperation relative to age, sex, BMI, graft type, or the presence of concomitant meniscal injury. The rates of ipsilateral ACLR and contralateral ACLR at any time during the study period was 8.0% and 10.9% respectively. There was no statistically significant difference for rate of reoperation between graft types, between various concomitant injuries, between those who underwent meniscus repair or no repair.

CONCLUSIONS

This study reflects a 34.7% rate of a subsequent knee operation after ACLR in patients younger than 18 years. These findings can be used to inform pediatric patients undergoing primary ACLR on their risk of returning to the operating room.

Returning Athletes to Sports Following Anterior Cruciate Ligament Tears

PURPOSE OF REVIEW

The purpose of this review is to discuss treatment options, rehabilitation protocols, return-to-play criteria, and expected outcomes after non-operative and operative treatment of anterior cruciate ligament (ACL) tears among an athletic population.

RECENT FINDINGS

Non-operative treatment may be a viable option for some athletes with an ACL tears but can be difficult to predict "copers," and those that resume to sports return at lower performance level and/or less intense activities. Most studies assessing function after ACL reconstruction demonstrate favorable outcomes using patient-reported outcome studies. However, return-to-play and graft re-rupture rates vary substantially based on patient characteristics and level and type of athletic activity. Grafts used to reconstruct ACL produce similar objective outcomes and favorable patient-reported outcomes but have variable re-rupture rates depending on study and differ largely on morbidity associated with graft harvest. Various treatment methods including non-operative and operative techniques have been demonstrated to be efficacious in returning athletes to athletic activity depending on patient age and level of activity. Adherence to fundamental rehabilitation principles and accepted return-to-play guidelines can optimize outcomes and limit re-injury to the injured or contralateral limb.

An increased posterior tibial slope is associated with a higher risk of graft failure following ACL reconstruction: a systematic review

PURPOSE

The posterior tibial slope (PTS) is considered a risk factor for anterior cruciate ligament (ACL) injury. However, the influence of PTS on graft failure following ACL reconstruction remains relatively unknown. Therefore, this systematic review was conducted to investigate whether PTS could be a potential risk factor for graft failure after ACL reconstruction.

METHODS

PubMed, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure Database, and Wanfang Database were comprehensively searched from inception to March 31, 2021. Observational studies reporting the associations of medial tibial plateau slope (MTPS) or lateral tibial plateau slope (LTPS) with graft failure after ACL reconstruction were evaluated.

RESULTS

Twenty studies involving 12 case-control studies, 4 retrospective studies and 4 cross-sectional studies including 5326 patients met the final inclusion criteria. The high heterogeneity and the characteristics of nonrandomized controlled trials limited data synthesis. Fifteen of the 20 included studies detected a significant association between increased PTS and ACL graft failure, while 5 studies concluded that increased PTS was not associated with ACL graft failure. Ten studies suggested that MTPS is associated with ACL graft failure, and six studies suggested that LTPS is associated with ACL graft failure. The mean MTPS values for nonfailure group ranged from 3.5° ± 2.5° to 14.4° ± 2.8°. For the graft failure group, MTPS ranged from 4.71° ± 2.41° to 17.2° ± 2.2°. The mean LTPS values for nonfailure group ranged from 2.9° ± 2.1° to 11.9° ± 3.0°. For the graft failure group, LTPS ranged from 5.5° ± 3.0° to 13.3° ± 3.0°. The reported PTS values that caused ACL graft failure was greater than 7.4° to 17°.

CONCLUSION

Based on the current clinical evidence, increased PTS is associated with a higher risk of ACL graft failure after ACL reconstruction. Despite various methods of measuring PTS have high reliability, there is still vast disagreement in the actual value of PTS.

LEVEL OF EVIDENCE

IV.

Computed Tomography Imaging under Artificial Intelligence Reconstruction Algorithm Used in Recovery of Sports Injury of the Knee Anterior Cruciate Ligament

This study aimed to analyze the influence of artificial intelligence (AI) reconstruction algorithm on computed tomography (CT) images and the application of CT image analysis in the recovery of knee anterior cruciate ligament (ACL) sports injuries. A total of 90 patients with knee trauma were selected for enhanced CT scanning and randomly divided into three groups. Group A used the filtered back projection (FBP) reconstruction algorithm, and the tube voltage was set to 120 kV during CT scanning. Group B used the iDose4 reconstruction algorithm, and the tube voltage was set to 120 kV during CT scanning. In group C, the iDose4 reconstruction algorithm was used, and the tube voltage was set to 100 kV during CT scanning. The noise, signal-to-noise ratio (SNR), carrier-to-noise ratio (CNR), CT dose index volume (CTDI), dose length product (DLP), and effective radiation dose (ED) of the three groups of CT images were compared. The results showed that the noise of groups B and C was smaller than that of group A (P < 0.05), and the SNR and CNR of groups B and C were higher than those of group A. The images of patients in group A with the FBP reconstruction algorithm were noisy, and the boundaries were not clear. The noise of the images obtained by the iDose4 reconstruction algorithm in groups B and C was improved, and the image resolution was also higher. The agreement between arthroscopy and CT scan results was 96%. Therefore, the iterative reconstruction algorithm of iDose4 can improve the image quality. It was of important value in the diagnosis of knee ACL sports injury.

Biplanar high tibial osteotomy for the combined correction of varus and posterior tibial slope malalignment

Varus malalignment combined with an increased posterior tibial slope (PTS) in the ACL deficient knee is a frequent pathology; yet, treatment for this condition remains challenging. The presented biplanar osteotomy technique allows to simultaneously address both components of malalignment in a single step. A detailed preoperative planning is best achieved by means of a digital planning software and constant intraoperative imaging is performed to verify the correction angle. A bony wedge is resected along with the extension osteotomy according to the preoperative planning and the medial-opening tibial osteotomy site is filled with bone allograft. Two bicortical lag screws are placed in anterior-posterior direction to secure the extension osteotomy, whereas a plate fixation is used for the medial-open osteotomy.

Is Lever Test Superior to Lachman, Pivot Shift, Drawer Tests in Diagnosing Anterior Cruciate Ligament Injuries?

Introduction: The physical examination in anterior cruciate ligament (ACL) injuries is extremely important, and the Lever test is commonly utilized on ACL evaluation. However, the number and scope of studies on the Lever test is limited. In this prospective cross-sectional study, we aimed to evaluate the effectiveness of the diagnostic values of Lachman, Pivot Shift, Lever, and Anterior Drawer tests in terms of quadriceps atrophy and case phase in ACL injuries.

Methods: In this prospective study, diagnostic values of Lachman, Pivot Shift, Lever, and Anterior Drawer tests were examined on 189 patients with positive MRI results as the gold standard.

Results: Lever test positivity was significantly more frequent in the group with quadriceps atrophy preoperative and after sedation (p<0.05). Anterior Drawer test positivity was significantly more frequent in the group with positive quadriceps atrophy preoperatively, after sedation and after spinal anesthesia (p<0.05). Lever and Anterior Drawer tests were positively correlated with quadriceps atrophy preop and after sedation (p<0.05). Lever test before surgery, after sedation and after spinal anesthesia in the chronic patient group was more positive than in the acute and subacute groups (p<0.05). Lever test was positively correlated with phase preoperatively, after sedation and after spinal anesthesia (p<0.01).

Conclusion: The presence or absence of quadriceps atrophy in patients with acute, sub-acute, or chronic ACL injury has a significant effect on the predictive value of the Lever test. We think that univariate analyzes may give incorrect results when demonstrating predictive value, and it would be more correct to perform multivariate analyzes.

Double-Layered Quadriceps Tendon Autografts Provide Lower Failure Rates and Improved Clinical Results Compared With Hamstring Tendon Grafts in Revision ACL Reconstruction

Background:

We developed a quadriceps-tendon graft technique using a double-layered, partial-thickness, soft tissue quadriceps tendon graft (dlQUAD) for anterior cruciate ligament reconstruction (ACLR). This technique allows simple femoral loop button fixation and a limited harvest depth of the quadriceps tendon.

Purpose:

To evaluate the outcome of patients undergoing revision ACLR using the dlQUAD technique compared with a hamstring tendon graft (HT).

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 114 patients who underwent revision ACLR between 2017 and 2018 were included in this retrospective case series. At a mean follow-up of 26.9 ± 3.7 months (range, 24-36), 89 patients (dlQUAD: n = 43, HT: n = 46) were clinically examined. In addition, patients completed the Lysholm score, Tegner activity scale, subjective International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score, and visual analog scale (VAS) for pain. Postoperative failure of the revision ACLR was defined as a side-to-side difference (SSD) in Rolimeter testing ≥5 mm or a pivot-shift grade of 2 or 3.

Results:

Nine patients (10.1%) were identified with a failed revision ACLR. There was a significantly lower failure rate with dlQUAD versus the HT group (2.3% vs 17.4%; P = .031). The mean postoperative SSD was significantly less in the dlQUAD group (1.3 ± 1.3 mm [range, 0-5] vs 1.8 ± 2.2 mm [range, 0-9]; P = .043). At the latest follow-up, Tegner and IKDC scores significantly improved in the dlQUAD group compared with the HT group (Tegner: 5.8 ± 1.8 vs 5.6 ± 1.5; P = .043; IKDC: 83.8 ± 12.2 vs 78.6 ± 16.8; P = .037). The pain VAS score was also significantly reduced in the dlQUAD group compared with the HT group (0.9 ± 1.1 vs 1.6 ± 2.0; P = .014).

Conclusion:

The dlQUAD and HT techniques both demonstrated significant improvement of preoperative knee laxity and satisfactory patient-reported outcome measures after revision ACLR. Compared with the HT grafts, the dlQUAD technique showed lower failure rates and small increases in Tegner and IKDC scores.

Three-in-One Procedure for Revision ACL Reconstruction

Revision anterior cruciate ligament (ACL) reconstruction is a challenge due to the unfavorable condition of the knee and the lack of autogenous graft tissue. Anterolateral structure (ALS) reconstruction of the knee has been proved effective to address the unfavorable condition in revision cases, and lateral extra-articular tenodesis (LET) is a special technique that can enhance anterolateral stability of the knee without graft tissue. We introduce a procedure that combines ACL and ALS reconstruction, as well as LET for failed ACL reconstruction. The critical point of this technique is using the anterior half of the iliotibial band to realize LET and to partially reconstruct the ACL. Our clinical experience indicates this technique is extremely useful in revision ACL reconstruction without enough free graft tissue. This technique will provide a reasonable choice in revision ACL reconstruction.

ACL Study Group presents the global trends in ACL reconstruction: biennial survey of the ACL Study Group

OBJECTIVES

The primary objective of this survey was to gauge the current global trends in anterior cruciate ligament reconstruction (ACLR) as reported by the members of the Anterior Cruciate Ligament (ACL) Study Group (SG).

METHODS

A survey was created and distributed among the members of the ACL SG consisting of 87 questions and 16 categories related to ACLR, including member demographics, preoperative management, primary ACLR techniques and graft choice, use of concomitant procedures and biological augmentation, postoperative rehabilitation, and more.

RESULTS

The survey was completed by the 140 members of the ACL SG. Fifty per cent of members are from Europe, 29% from the USA, 15% from the Asia-Pacific and the remaining 6% are from Latin America, the Middle East, New Zealand and Africa. Most (92%) do not believe there is a role for non-operative management of ACL tears in higher level athletes; conversely, most agree there is a role for non-operative management in lower impact athletes (92%). A single-bundle (90%) technique with hamstring autograft (53%) were most common for primary ACLR. Tunnel position varied among respondents. Sixty-one per cent do not use allograft for primary ACLR. Fifty per cent of respondents use cortical suspensory fixation on the femur, with variable responses on the tibia. Most (79%) do not use biologics in primary ACLR, while 83% think there is a selective role for extra-articular augmentation in primary ACLR. Fifty per cent prefer bone-tendon-bone autograft for revision ACLR and extra-articular augmentation is more commonly used (13% always, 26% often) than in primary ACLR (0% always, 15% often). A majority (53%) use a brace after primary ACLR. The most common responses for minimal time to return to play after primary ACLR were 6-8 months (44%) and 8-12 months (41%).

CONCLUSION

We presented the thoughts and preferences of the ACL SG on the management of ACL injuries. This survey will help to facilitate an ongoing discussion with regard to ACLR by providing global insights into the current surgical trends in ACLR.

LEVEL OF EVIDENCE

Level V, Expert Opinion.

A Quantifiable Risk Factor for ACL Injury: Applied Mathematics to Model the Posterolateral Tibial Plateau Surface Geometry

Background:

The mechanism for traumatic ruptures of the native anterior cruciate ligament (ACL) is frequently a noncontact injury involving a valgus moment with internal rotation of the tibia. The abnormal rotation and translation of the lateral femoral condyle posteroinferiorly relative to the lateral tibial plateau is thought to be related to the geometry of the tibial plateau.

Purpose/Hypothesis:

The purpose of the study was to mathematically model the posterior tibial plateau geometry in patients with ACL injuries and compare it with that of matched controls. The hypothesis was that increased convexity and steepness of the posterior aspect of the lateral plateau would subject knees to higher forces, leading to a potentially higher risk of ACL injury.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We mathematically modeled the posterior curvature of the lateral tibial plateau in 64 patients with ACL injuries and 68 matched controls. Using sagittal magnetic resonance imaging scans of the knee, points on the articular cartilage of the posterolateral tibial plateau were selected and curve-fitted to a power function (y = a × xⁿ). For coefficient a and coefficient n, both variables modulated the shape of the curve, where a larger magnitude represented an increase in slope steepness. Groups were compared using a Mann-Whitney test and α < .05.

Results:

There was a significant difference in surface geometry between the patients with ACL injuries and matched controls. The equation coefficients were significantly larger in the patients with ACL injuries: coefficient a (ACL injury, 0.9 vs control, 0.68; P < .0001) and coefficient n (ACL injury, 0.34 vs control, 0.30; P = .07). For coefficient a, there was a 78.9% sensitivity, 77.5% specificity, and odds ratio of 12.6 (95% CI, 5.5-29.0) for ACL injury using a cutoff coefficient a = .78.

Conclusion:

Patients with ACL injuries had a significantly greater posterolateral plateau slope. The steeper drop off may play a role in higher anterior translation forces, coupled with internal rotation torques on the knee in noncontact injury, which could increase ACL strain and predispose to ACL injury.

One-Stage Anatomical Revision Anterior Cruciate Ligament Reconstruction: Results According to Tunnel Overlaps

PURPOSE

To present clinical results according to tunnel overlap in 1-stage anatomical revision anterior cruciate ligament reconstruction (ACLR).

METHODS

All patients who underwent revision ACLR performed by a single surgeon (J.H.A.) from 2012 to 2017 and were followed up for >24 months were retrospectively evaluated. The exclusion criteria were concomitant ligament injury, including medial collateral ligament injury, modified Outerbridge grade ≥3 cartilage lesion, and severe meniscus defects. Tunnel overlap was measured on 3-dimensionally reconstructed computed tomography images. Patients in the nonoverlapped femoral tunnel group (group NO, n = 52) were treated with new tunnel drilling that completely avoided previous tunnels, and those in the overlapped femoral tunnel group (group O, n = 41) were treated with a new tunnel that overlapped with previous tunnels. Clinical outcomes were evaluated using the subjective International Knee Documentation Committee (IKDC) and Lysholm scores. Knee joint stability was measured using the Lachman and pivot shift tests. Patients with femoral tunnel widening of ≥14 mm underwent 2-stage ACLR.

RESULTS

The mean follow-up duration of 93 patients was 46.9 months (range, 24-97 months). All preoperative subjective and objective IKDC (P<0.001) and Telos stress test scores (P = .016) were significantly improved at the last follow-up. Forty-one patients had overlapping femoral tunnels, whereas 87 had overlapping tibial tunnels. At the last follow-up, subjective IKDC and Lysholm scores (73.6 ± 15.3 vs 74.9 ± 12.1, P = .799 and 80.0 ± 19.2 vs 81.44 ± 13.5, P = .505, respectively) and objective pivot shift (IKDC grade) in the Lachman test (P = .183 and P = .450, respectively) did not differ significantly between groups NO and O, respectively.

CONCLUSIONS

One-stage anatomical revision ACLR significantly improved the clinical results. Most tibial tunnels (94%) and approximately one-half (44%) of the femoral tunnels overlapped. The overlapped femoral tunnel group did not show inferior outcomes or stability.

LEVEL OF EVIDENCE

Level III, cohort study.

A Systematic Review of Risk Factors for Anterior Cruciate Ligament Reconstruction Failure

Although most studies have introduced risk factors related to anterior cruciate ligament reconstruction failure, studies on combinations of high-risk factors are rare. To provide a systematic review of the risk factors of anterior cruciate ligament reconstruction failure to guide surgeons through the decision-making process, an extensive literature search was performed of the Medline, Embase and Cochrane Library databases. Studies published between January 1, 2009, and September 19, 2019, regarding the existing evidence for risk factors of anterior cruciate ligament reconstruction failure or graft failure were included in this review. Study quality was evaluated with the quality index. Ultimately, 66 articles met our criteria. There were 46 cases classified as technical factors, 21 cases as patient-related risk factors, and 14 cases as status of the knee joint. Quality assessment scores ranged from 14 to 24. This systematic review provides a comprehensive summary of the risk factors for anterior cruciate ligament reconstruction failure, including technical factors, patient-related factors, and the factors associated with the status of the knee joint. Emphasis should be placed on avoiding these high-risk combinations or correcting modifiable risk factors during preoperative planning to reduce the rate of graft rupture and anterior cruciate ligament reconstruction failure.

[Effectiveness of double-bundle anterior cruciate ligament reconstruction combined with anterolateral ligament reconstruction for revision]

Objective

To investigate the effectiveness of double-bundle anterior cruciate ligament (ACL) reconstruction combined with anterolateral ligament (ALL) reconstruction in the treatment of revision patients with ACL graft failure.

Methods

Between January 2018 and June 2019, 15 patients underwent ACL revision with double-bundle ACL reconstruction combined with ALL reconstruction. There were 12 males and 3 females with an average age of 30.1 years (range, 17-49 years). The technique of primary ACL reconstruction included single-bundle reconstruction in 13 cases and double-bundle reconstruction in 2 cases. These reconstructions applied autografts in 14 cases and allograft in 1 case. The causes of ACL reconstruction failure were identified as traumatic rupture in 9 cases and non-traumatic failure in 6 cases, including 2 cases of graft absorption and 3 cases of graft laxity. The average time from the primary ACL reconstruction to revision was 28.5 months (range, 8-60 months). The subjective and objective indicators of knee joint function were compared before operation and at last follow-up to evaluate the effectiveness. The subjective indicators included International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner score. The objective indicators included anterior tibial translation (dynamic and static) and side-to-side difference (SSD), pivot-shift test, Lachman test, the difference of single-legged hop test, and the loss ratio of extensor muscle strength on the affected side.

Results

All incisions healed by first intetion, and no complications such as infection, venous thrombosis of lower extremity, or neurovascular injury occurred. All patients were followed up for an average of 19.1 months (range, 12-30 months). At last follow-up, all patients had returned to pre-injury sports level. The IKDC score, Lysholm score, and Tegner score were significantly improved ( P<0.05); anterior tibial translations (dynamic and static) significantly decreased when compared with preoperative one ( P<0.05) and returned to the physiological range. The SSD, Lachman test, pivot-shift test, the difference of single-legged hop test, and the loss ratio of extensor muscle strength on the affected side were significantly better than those before operation ( P<0.05).During the follow-up, there was no re-rupture of the graft, no stiffness of the knee joint and limitation of mobility; 1 case had a protruding femoral end compression screw, which was removed through the original incision under local anesthesia.

Conclusion

Double-bundle ACL reconstruction combined with ALL reconstruction can significantly improve the knee function in revision patients with ACL graft failure. It can reduce the anterior translation of tibia, and effectively prevent postoperative rotational instability of the knee.

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

Background:

Concomitant lesion of the medial collateral ligament (MCL) is associated with a greater risk of anterior cruciate ligament (ACL) graft failure.

Purpose:

The aim of this study was to compare two medial stabilization techniques in patients with revision ACL reconstruction (ACLR) and concomitant chronic medial knee instability.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

In a retrospective study, we included 53 patients with revision ACLR and chronic grade 2 medial knee instability to compare medial surgical techniques (MCL reconstruction [n = 17] vs repair [n = 36]). Postoperative failure of the revision ACLR (primary aim) was defined as side-to-side difference in Rolimeter testing ≥5 mm or pivot-shift grade ≥2. Clinical parameters and postoperative functional scores (secondary aim) were evaluated with a mean ± SD follow-up of 28.8 ± 9 months (range, 24-69 months).

Results:

Revision ACLR was performed in 53 patients with additional grade 2 medial instability (men, n = 33; women, n = 20; mean age, 31.3 ± 12 years). Failure occurred in 5.9% (n = 1) in the MCL reconstruction group, whereas 36.1% (n = 13) of patients with MCL repair showed a failed revision ACLR (P = .02). In the postoperative assessment, the anterior side-to-side difference in Rolimeter testing was significantly reduced (1.5 ± 1.9 mm vs 2.9 ± 2.3 mm; P = .037), and medial knee instability occurred significantly less (18% vs 50%; P = .025) in the MCL reconstruction group than in the MCL repair group. In the logistic regression, patients showed a 9-times elevated risk of failure when an MCL repair was performed (P = .043). Patient-reported outcomes were increased in the MCL reconstruction group as compared with MCL repair, but only the Lysholm score showed a significant difference (Tegner, 5.6 ± 1.9 vs 5.3 ± 1.6; International Knee Documentation Committee, 80.3 ± 16.6 vs 73.6 ± 16.4; Lysholm, 82.9 ± 13.6 vs 75.1 ± 21.1 [P = .047]).

Conclusion:

MCL reconstruction led to lower failure rates in patients with combined revision ACLR and chronic medial instability as compared with MCL repair. MCL reconstruction was superior to MCL repair, as lower postoperative anterior instability, an increased Lysholm score, and less medial instability were present after revision ACLR. MCL repair was associated with a 9-times greater risk of failure.

Slope-Correction Osteotomy with Lateral Extra-articular Tenodesis and Revision Anterior Cruciate Ligament Reconstruction Is Highly Effective in Treating High-Grade Anterior Knee Laxity

BACKGROUND

Both an elevated posterior tibial slope (PTS) and high-grade anterior knee laxity are often present in patients who undergo revision anterior cruciate ligament (ACL) surgery, and these conditions are independent risk factors for ACL graft failure. Clinical data on slope-correction osteotomy combined with lateral extra-articular tenodesis (LET) do not yet exist.

PURPOSE

To evaluate the outcomes of patients undergoing revision ACL reconstruction (ACLR) and slope-correction osteotomy combined with LET.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2016 and 2018, we performed a 2-stage procedure: slope-correction osteotomy was performed first, and then revision ACLR in combination with LET was performed in 22 patients with ACLR failure and high-grade anterior knee laxity. Twenty patients (6 women and 14 men; mean age, 27.8 ± 8.6 years; range, 18-49 years) were evaluated, with a mean follow-up of 30.5 ± 9.3 months (range, 24-56 months), in this retrospective case series. Postoperative failure was defined as a side-to-side difference of ≥5 mm in the Rolimeter test and a pivot-shift grade of 2 or 3.

RESULTS

The PTS decreased from 15.3° to 8.9°, the side-to-side difference decreased from 7.2 to 1.1 mm, and the pivot shift was no longer evident in any of the patients. No patients exhibited revision ACLR failure and all patients showed good to excellent postoperative functional scores (mean ± SD: visual analog scale, 0.5 ± 0.6; Tegner, 6.1 ± 0.9; Lysholm, 90.9 ± 6.4; Knee injury and Osteoarthritis Outcome Score [KOOS] Symptoms, 95.2 ± 8.4; KOOS Pain, 94.7 ± 5.2; KOOS Activities of Daily Living, 98.5 ± 3.2; KOOS Function in Sport and Recreation, 86.8 ± 12.4; and KOOS Quality of Life, 65.4 ± 14.9).

CONCLUSION

Slope-correction osteotomy in combination with LET is a safe and reliable procedure in patients with high-grade anterior knee laxity and a PTS of ≥12°. Normal knee joint stability was restored and good to excellent functional scores were achieved after a follow-up of at least 2 years.

RETURN TO PLAY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

ABSTRACT The anterior cruciate ligament (ACL) tear represents more than half of all knee injuries in sports that involve body rotations and sudden changes of direction. Discharging the athlete for return to play (RTP) post-ACL reconstruction (ACLR) is a difficult task with multidisciplinary responsibility. For many years, a six-month period post-ACLR was adopted as the only criterion for RTP. However, it is now suggested that RTP should not be exclusively time-based, but to clinical data and systematic assessments. Despite the importance of post-ACLR factors for RTP, pre- and peri-ACLR factors must also be considered. Historically, ACLR is performed with the hamstring or autologous patellar tendons, although the choice of graft is still an open and constantly evolving theme. Anterolateral ligament reconstruction and repair of meniscal ramp tear associated with ACLR have recently been suggested as strategies for improving knee joint stability. Subjective questionnaires are easy to apply, and help identify physical or psychological factors that can hamper RTP. Functional tests, such as hop tests and strength assessment by means of isokinetic dynamometers, are fundamental tools for decision making when associated with clinical evaluation and magnetic resonance imaging. Recently, the capacity to generate force explosively has been incorporated into the muscle strength assessment. This is quantified through the rate of torque development (RTD). Due to characteristics inherent to the practice of sport, there is an extremely short time available for produce strength. Thus, RTD seems to better represent athletic demands than the maximum strength assessment alone. This review investigates the pre-, peri- and post-ACLR factors established in the literature, and shares our clinical practice, which we consider to be best practice for RTP. Level of evidence V; Specialist opinion.

Lateral extra-articular tenodesis in patients with revision anterior cruciate ligament (ACL) reconstruction and high-grade anterior knee instability

BACKGROUND

Additional lateral extra-articular procedures can reduce the risk of failure of primary anterior cruciate ligament reconstruction (ACLR). There is limited evidence on the effect of lateral extra-articular procedures in revision ACL surgery. The purpose of this study was to evaluate the clinical outcome of patients with lateral extra-articular tenodesis (LET) in combination with revision ACLR for combined ACL graft failure and high-grade anterior knee instability.

METHODS

Between 2016 and 2018, 75 patients with graft failure after primary ACLR and high-grade anterior knee instability who received revision ACLR were included in the retrospective study. High-grade anterior knee instability was defined as high-grade pivot-shift or side-to-side difference of more than six millimeters in Rolimeter®-testing. An additional modified Lemaire tenodesis was performed in 59 patients during revision ACLR. Seventy-three patients were clinically examined with a minimum of two years after revision surgery.

RESULTS

Failure of the revision ACLR occurred in 8.2% (n = 6) of the cases. LET lead to significant decreased failure rates (five percent vs. 21%, p = .045) and decreased incidence of a positive pivot-shift in patients with revision ACLR and high-grade anterior knee instability in comparison to patients without LET. Also, postoperative functional scores were significantly increased in the group of additional LET.

CONCLUSIONS

Additional LET in patients with revision ACLR and high-grade anterior instability significantly reduces the risk of failure of revision ACLR, the incidence of pivot-shift and increases postoperative functional outcome.

Tibial Slope Correction as an Infratuberosity Closing-Wedge Extension Osteotomy in ACL-Deficient Knees

ACL insufficiency can be caused by different reasons. Elevated posterior tibial slope is a deformity which is discussed to have relevant influence on the outcome of ACL surgery. A increased posterior tibial slope of 12° or more leads to significant more ACL insufficiency. The surgical therapy of this pathology is a high tibial extension osteotomy. Publications ashowing a clinical follow up and results of this surgery are rare. In this video the technique of a closed wedge high tibial extension osteotomy is shown. Osteosynthesis is performed with two screws and an anklestable plate osteosynthesis. An arthroscopy with bone graft filling of the femoral ACL tunnel is performed first, followed by filling of the tibial tunnel in an open approach.

Greater medial tibial slope is associated with increased anterior tibial translation in females with an ACL-deficient knee

PURPOSE

The purpose of the study was to determine the correlation between medial tibial slope (MTS) and anterior tibial translation (ATT) in female patients with an ACL-deficient knee. It was hypothesized that female patients with a greater medial tibial slope had an increased anterior tibial translation compared to males.

METHODS

MTS and ATT were analysed in 276 patients (138 females and 138 males) with a complete ACL rupture from 2012 to 2016. The mean age was 32 ± 12 years. Previous surgery or additional ligament injury was excluded. CT scan was used for measuring MTS. Meniscal findings were reported. Anterior tibial translation and side to side difference (SSD) were measured by bilateral Telos™ stress radiography with knee flexion of 20°.

RESULTS

There was no significant difference in ATT between females (5.4 ± 3.9) and males (5.8 ± 4.2), nor was there a difference in MTS between females (9.8 ± 2.8) and males (9.8 ± 2.7). A positive correlation was found between MTS and ATT absolute (r = 0.35, p < 0.001) and side to side difference (r = 0.12, p = 0.03). MTS greater or equal to 11° significantly increased the ATT (p < 0.05). For each degree of increase of the MTS, increases in ATT absolute of 0.6 mm and SSD of 0.18 mm were observed. Greater MTS was identified as a risk factor for an increase of ATT in females (r = 0.37, p < 0.001) but not in males (r = - 0.1, n.s). Increases of 1° of MTS increased ATT 0.57 mm in female patients (p < 0.001). MTS was influential in ATT despite the presence (r = 0.28 [0.11, 0.44], p = 0.001) or absence (r = 0.48 [0.35, 0.6], p < 0.001) of meniscal lesions.

CONCLUSIONS

Greater medial tibial slope is associated with increased anterior tibial translation in females with ACL-deficient knees compared to males, despite the presence or absence of meniscal lesions. This could be due to a quadriceps/hamstring imbalance in females and the ability of the hamstring muscles to moderate ATT.

LEVEL OF EVIDENCE

III.

Preoperative medial knee instability is an underestimated risk factor for failure of revision ACL reconstruction

PURPOSE

The purpose of this study was to carefully analyse the reasons for revision ACLR failure to optimize the surgical revision technique and minimize the risk of recurrent re-rupture. Large studies with a minimum of 2 years of follow-up that clinically examine patients with revision ACLR are rare.

METHODS

Between 2013 and 2016, 111 patients who underwent revision ACLR were included in the retrospective study. All patients were examined for a minimum of 2 years after revision surgery (35 ± 3.4 months, mean ± STD) and identified as "failed revision ACLR" (side-to-side difference ≥ 5 mm and pivot-shift grade 2/3) or "stable revision ACLR".

RESULTS

Failure after revision ACLR occurred in 14.5% (n = 16) of the cases. Preoperative medial knee instability (n = 36) was associated with failure; thus, patients had a 17 times greater risk of failure when medial knee instability was diagnosed (p = 0.015). The risk of failure was reduced when patients had medial stabilization (n = 24, p = 0.034) and extra-articular lateral tenodesis during revision surgery (n = 51, p = 0.028). Increased posterior tibial slope (n = 11 ≥ 12°, p = 0.046) and high-grade anterior knee laxity (side-to-side difference > 6 mm and pivot-shift grade 3, n = 41, p = 0.034) were associated with increased failure of revision ACLR. Obese patients had a 9 times greater risk of failure (p = 0.008, n = 30).

CONCLUSION

This study demonstrates the largest revision ACLR patient group with pre- and postoperative clinical examination data and a follow-up of 2 years published to date. Preoperative medial knee instability is an underestimated risk factor for revision ACLR failure. Additionally, high-grade anterior knee laxity, increased PTS and high BMI are risk factors for failure of revision ACLR, while additional medial stabilization and lateral extra-articular tenodesis reduce the risk of failure.

LEVEL OF EVIDENCE

III.

Slope-reducing tibial osteotomy decreases ACL-graft forces and anterior tibial translation under axial load

PURPOSE

Posterior tibial slope (PTS) represents an important risk factor for anterior cruciate ligament (ACL) graft failure, as seen in clinical studies. An anterior closing wedge osteotomy for slope reduction was performed to investigate the effect on ACL-graft forces and femoro-tibial kinematics in an ACL-deficient and ACL-reconstructed knee in a biomechanical setup.

METHODS

Ten cadaveric knees with a relatively high native slope (mean ± SD): (slope 10° ± 1.4°, age 48.2 years ± 5.8) were selected based on prior CT measurements. A 10° anterior closing-wedge osteotomy was fixed with an external fixator in the ACL-deficient and ACL-reconstructed knee (quadruple Semi-T/Gracilis-allograft). Each condition was randomly tested with both the native tibial slope and the post-osteotomy reduced slope. Axial loads (200 N, 400 N), anterior tibial draw (134 N), and combined loads were applied to the tibia while mounted on a free moving and rotating X-Y table. Throughout testing, 3D motion tracking captured anterior tibial translation (ATT) and internal tibial rotation (ITR). Change of forces on the reconstructed ACL-graft (via an attached load-cell) were recorded, as well.

RESULTS

ATT was significantly decreased after slope reduction in the ACL-deficient knee by 4.3 mm ± 3.6 (p < 0.001) at 200 N and 6.2 mm ± 4.3 (p < 0.001) at 400N of axial load. An increase of ITR of 2.3° ±2.8 (p < 0.001) at 200 N and by 4.0° ±4.1 (p < 0.001) at 400 N was observed after the osteotomy. In the ACL-reconstructed knee, ACL-graft forces decreased after slope reduction osteotomy by a mean of 14.7 N ± 9.8 (p < 0.001) at 200 N and 33.8 N ± 16.3 (p < 0.001) at 400N axial load, which equaled a relative decrease by a mean of 17.0% (SD ± 9.8%), and 33.1% (SD ± 18.1%), respectively. ATT and ITR were not significantly changed in the ACL-reconstructed knee. Testing of a tibial anterior drawing force in the ACL-deficient knee led to a significantly increased ATT by 2.7 mm ± 3.6 (p < 0.001) after the osteotomy. The ACL-reconstructed knee did not show a significant change (n.s.) in ATT after the osteotomy. However, ACL-graft forces detected a significant increase by 13.0 N ± 8.3 (p < 0.001) after the osteotomy with a tibial anterior drawer force, whereas the additional axial loading reduced this difference due to the osteotomy (5.3 N ± 12.6 (n.s.)).

CONCLUSIONS

Slope-reducing osteotomy decreased anterior tibial translation in the ACL-deficient and ACL-reconstructed knee under axial load, while internal rotation of the tibia increased in the ACL-deficient status after osteotomy. Especially in ACL revision surgery, the osteotomy protects the reconstructed ACL with significantly lower forces on the graft under axial load.

Patients With Failed Anterior Cruciate Ligament Reconstruction Have an Increased Posterior Lateral Tibial Plateau Slope: A Case-Controlled Study

PURPOSE

To compare knee anatomical parameters of patients with failed anterior cruciate ligament reconstruction (ACL-R) with those of a control group of sex-matched patients with successful ACL-R.

METHODS

Forty-three patients (34 male, 9 female) who experienced graft failure after ACL-R were enrolled in the failed group. These patients were matched to a control group of 43 patients who underwent primary ACL-R with a minimum follow-up of 24 months. On magnetic resonance imaging, the following parameters were evaluated: transepicondylar distance, lateral and medial femoral condyle widths, tibial plateau width, notch width index, and the ratio of width and height of the femoral notch, ratio between the height and depth of the lateral and medial femoral condyle, lateral and medial posterior tibial slopes, and anterior subluxation of the lateral and medial tibial plateau. Multivariate regression with backward elimination, including only the previously identified significant variables, defined the independent predictors for revision surgery.

RESULTS

The anatomical variables that were significantly different between the 2 study groups were lateral and medial posterior tibial slopes, anterior subluxation of the lateral and medial tibial plateau, medial tibial plateau width, lateral tibial plateau width, medial femoral condyle width, and transepicondylar distance; however, the multivariate regression analysis identified the lateral posterior tibial slope (LTPs), the anterior subluxation of the medial tibial plateau, and the medial femoral condyle width as significant independent predictors (P < .05). The LPTs had the highest coefficient and the highest sensitivity (88%) and specificity (84%) to identify failures when considering the optimal cutoff value of 7.4°.

CONCLUSIONS

Several anatomical parameters have been identified that differ significantly between patients with failed ACL-R and those without a documented failure. The most accurate predictor of ACL failure was an LTPs >7.4°, with a sensitivity of 88% and specificity of 84%. Surgeons should consider measuring LTPs during preoperative assessment of ACL-injured patients, and patients with values >7.4° should be considered at high risk of ACL-R failure.

LEVEL OF EVIDENCE

Level III retrospective prognostic trial.

Osteotomies in the Multiple Ligament Injured Knee: When Is It Necessary?

The multiple ligament-injured knee is a complex injury requiring a comprehensive and thorough evaluation prior to tailoring an appropriate treatment plan. Surgical repair and reconstruction of the involved ligaments are frequently discussed in the literature; however, osteotomy to correct limb malalignment may be just as important to obtaining a good outcome. Limb realignment must be carefully evaluated and treated. Isolated soft tissue procedures are prone to failure if significant malalignment, deformity, and thrust are ignored. In select cases, osteotomy can lead to restored mechanical stability, optimal joint load distribution, improved survival of simultaneous soft tissue procedures, and better patient outcomes.

Steep Posterior Tibial Slope, Anterior Tibial Subluxation, Deep Posterior Lateral Femoral Condyle, and Meniscal Deficiency Are Common Findings in Multiple Anterior Cruciate Ligament Failures: An MRI Case-Control Study

BACKGROUND

Tibiofemoral anatomic parameters, such as tibial slope, femoral condyle shape, and anterior tibial subluxation, have been suggested to increase the risk of anterior cruciate ligament (ACL) reconstruction failure. However, such features have never been assessed among patients experiencing multiple failures of ACL reconstruction.

PURPOSE

To compare the knee anatomic features of patients experiencing a single failure of ACL reconstruction with those experiencing multiple failures or with intact ACL reconstruction.

STUDY

Case-control study; Level of evidence, 3.

METHODS

Twenty-six patients who experienced failure of revision ACL reconstruction were included in the multiple-failure group. These patients were matched to a group of 25 patients with failure of primary ACL reconstruction and to a control group of 40 patients who underwent primary ACL reconstruction with no failure at a minimum follow-up of 24 months. On magnetic resonance imaging (MRI), the following parameters were evaluated: ratio between the height and depth of the lateral and medial femoral condyles, the lateral and medial tibial plateau slopes, and anterior subluxation of the lateral and medial tibial plateaus with respect to the femoral condyle. The presence of a meniscal lesion during each procedure was evaluated as well. Anatomic, demographic, and surgical characteristics were compared among the 3 groups.

RESULTS

The patients in the multiple-failure group had significantly higher values of lateral tibial plateau slope ( P < .001), medial tibial plateau slope ( P < .001), lateral tibial plateau subluxation ( P < .001), medial tibial plateau subluxation ( P < .001), and lateral femoral condyle height/depth ratio ( P = .038) as compared with the control group and the failed ACL reconstruction group. Moreover, a significant direct correlation was found between posterior tibial slope and anterior tibial subluxation for the lateral ( r = 0.325, P = .017) and medial ( r = 0.421, P < .001) compartments. An increased anterior tibial subluxation of 2 to 3 mm was present in patients with a meniscal defect at the time of the MRI as compared with patients who had an intact meniscus for both the lateral and the medial compartments.

CONCLUSION

A steep posterior tibial slope and an increased depth of the lateral femoral condyle represent a common finding among patients who experience multiple ACL failures. Moreover, higher values of anterior subluxation were found among patients with repeated failure and those with a medial or lateral meniscal defect.

Editorial Commentary: Anteromedial Femoral Socket Drilling in Anterior Cruciate Ligament Reconstruction … Love the Way You Are

The goal of the anterior cruciate ligament reconstruction is to avoid a permanent pivot shift. There are no significant differences in the clinical outcomes between performing anterior cruciate ligament reconstruction using anteromedial or transtibial technique in performing femoral socket. Although most previous studies have shown better results in avoiding pivot shift using the anteromedial technique, its clinical significance still needs to be determined and, in my opinion, the transtibial technique still remains the gold standard.

Anterolateral Ligament Reconstruction Practice Patterns Across the United States

Background:

A proposed mechanism for recurrent instability following anterior cruciate ligament (ACL) reconstruction is failure of the anterolateral ligament (ALL). Presently, there are a number of approaches to treating ALL pathology.

Purpose:

To determine practice patterns among orthopaedic surgeons regarding ALL during ACL reconstruction.

Study Design:

Cross-sectional study.

Methods:

An online 7-question survey was sent to all physicians registered with the American Orthopaedic Society for Sports Medicine between June and July 2017. Results were analyzed with the survey website.

Results:

Overall, 225 of 3467 surgeons responded to the survey, 86 of whom performed ALL reconstruction and completed each question in the survey. Eighty-six (38.2%) surgeons who responded to the questionnaire stated that they perform ALL reconstruction/lateral extra-articular tenodesis in conjunction with ACL reconstruction. The most common indications for ALL reconstruction were grade III pivot-shift test (46.0%) on physical examination and revision ACL reconstruction (46.0%). The most common technique used to perform ALL reconstruction was hamstring autograft (48.2%). The majority of participating surgeons (87.5%) stated that they do not make any alterations to their postoperative rehabilitation protocol after they perform ALL reconstruction. In addition, most surgeons responding to the survey (91.3%) anticipated either an increase in or the same number of ALL procedures performed in the coming year.

Conclusion:

The majority of surgeons who responded to the survey did not routinely reconstruct the ALL. Revision procedures and grade III pivot shift were the most cited indications for performing lateral augmentation. Anatomic reconstruction with hamstring was the most commonly used procedure, although there was no consensus among surgeons responding to the survey. Understanding the ALL and its contribution to knee stability is essential. For a community of physicians, it is useful to discover how fellow sports orthopaedic surgeons address ALL pathology to integrate effective and efficient treatment strategies into practice.