Deficient Knee Research Articles

Fixed-Bearing Medial Unicompartmental Knee Arthroplasty: New Indications and the Anterior Cruciate Ligament-Deficient Knee

The anterior cruciate ligament (ACL)-deficient osteoarthritic knee is a challenging disease entity which requires careful thought to restore function and return to activities. Advancements in technology and surgical techniques have expanded indications for unicompartmental knee arthroplasty (UKA), to include ACL-deficiency in select patients. An improved understanding of the ACL-deficient osteoarthritic knee can aid in clinical and surgeon decision-making to restore knee function. This review will discuss current practice guidelines for the ACL-deficient knee with single-compartment osteoarthritis including pathoanatomy, indications, contraindications, technical considerations, and clinical outcomes.

Approaching ramp lesions from the different world of posterior knee compartment: A review of evidence with a proposal of a new classification and treatment

AbstractRamp lesions (RLs) are peripheral lesions that occur in the posterior part of the medial meniscus or where it attaches to the joint capsule. The classification of the medial meniscus RLs has been the focus of numerous studies and publications. This review provides an overview of RL's current classification and treatment options in anterior cruciate ligament deficient knees. The study also aims to present a more practical classification system for RLs to assist in treatment decision‐making. For the first time, we also presented a new surgical treatment for incomplete inferior and double‐complete RL based on the posterior knee arthroscopy that provides direct access to the posterior meniscal borders, enabling effective treatment and stronger biomechanical repair.Level of EvidenceLevel V.

The Fibular Collateral Ligament Is a More Important Restraint to Varus Laxity Compared to the Anterolateral Complex in the Anterior Cruciate Ligament–Deficient Knee in a Cadaveric Biomechanical Study

PurposeThe purpose of this study was to compare the influence of the fibular collateral ligament (FCL) and the anterolateral complex (ALC) on varus knee laxity in paired anterior cruciate ligament (ACL)-deficient cadaveric knees using varus stress radiographs. MethodsVarus laxity in nine paired (N=18, mean age 73.8 years) human cadaveric knees was assessed using varus stress radiographs with a 12 Nm varus stress applied at 20° of knee flexion. All knees underwent testing in the intact state and following ACL sectioning. One knee of each pair was randomly assigned to undergo FCL sectioning and the contralateral knee was assigned to undergo ALC sectioning (anterolateral ligament [ALL] followed by the Kaplan fibers). ResultsBoth FCL sectioning and ALC (ALL and the Kaplan fibers) sectioning resulted in increased lateral compartment gapping compared to the intact state, 2.44 mm and 1.13 mm, respectively. ALL sectioning with intact Kaplan fibers did not result in increased lateral compartment gapping. Paired knee comparison revealed a significantly greater influence of the FCL than the ALC in restraining lateral compartment gapping under an applied varus stress (p=0.0003). ConclusionsSectioning the FCL resulted in significantly greater lateral compartment gapping under a varus stress than combined sectioning of the ALL and Kaplan fibers in an ACL deficient knee, although both scenarios resulted in significantly increased gapping compared to the intact state. Sectioning of the ALL with intact Kaplan fibers did not result in increased lateral compartment gapping. Clinical RelevanceThe FCL is the most important structure in restraining varus laxity in the ACL deficient knee and the ALC is of secondary importance in restraining varus laxity. In ACL deficient patients with a high-grade pivot shift, mild varus laxity on clinical examination, and an intact FCL on MRI, injury to the anterolateral complex should be considered and may be evaluated with varus stress radiographs. This study validates prior biomechanical studies of FCL deficiency and demonstrates that approximately 1 mm increase in lateral compartment gapping on varus stress radiographs may occur secondary to ALC injury and clinicians should be aware of this when considering treatment for ACL deficient patients with high-grade anterolateral laxity.

Fixed-Bearing Lateral Unicompartment Knee Arthroplasty in Degenerative ACL-Deficient and ACL-Intact Knees: A Matched Pair Analysis

BackgroundAnterior cruciate ligament (ACL)-deficient knees are no longer considered a contra-indication for unicompartment knee arthroplasty (UKA). The purpose of this study was to determine if patients who had an ACL-deficient knee who underwent lateral UKAs had similar mean 10-year outcomes compared to ACL-intact lateral UKA knees. MethodsPatients who underwent a lateral UKA with ACL deficiency by a single surgeon between 2004 and 2016, were identified. Preoperative magnetic resonance images (MRI) were utilized to identify a torn or absent ACL in all knees. The absence of an ACL was confirmed during arthroscopy prior to UKA. Patients were matched 1:2 based on age and sex with patients who underwent lateral UKA where the ACL was intact. The primary patient-reported outcome variable was survival without conversion to total knee arthroplasty. Secondary outcomes included Veterans Rand (VR)-12, the Lysholm score, the Knee Osteoarthritis Outcome Score (KOOS) Activities of Daily Living subscale, and Sport subscale. A power analysis showed that 14 patients were needed to identify differences of 10 points on the KOOS score with a power of 80%(p=0.05). ResultsThe cohort of ACL-deficient lateral UKA patients included 4 men and 12 women (43 to 82 years of age). The matched control group included 32 patients. The mean age of both groups was 67 years (range, 43 to 85). There were two patients in the ACL-deficient group who failed. At 10 years, survivorship in the ACL-deficient group was 85%, while survival in the ACL-intact group was 100% (P = 0.035). At an average follow-up of 11 years (range, 4 to 19.6), there was no difference in outcome scores between ACL-deficient and ACL-intact patients. ConclusionFixed-bearing lateral UKA in the ACL-deficient knee resulted in lower survival compared to patients who had an intact ACL. Patient-reported outcomes were similar in both groups. The ACL-deficient patient who wishes to undergo lateral UKA should be counseled on the lower survival.

Reduced physiological extrusion of the medial meniscus in axial load-bearing condition in anterior cruciate ligament deficiency.

In this study, ultrasonography was used to measure medial meniscus (MM) extrusion under weight-bearing and nonweight-bearing conditions in both anterior cruciate ligament (ACL)-deficient and ACL-intact knee groups. This study aimed to determine the possible differences between these groups with an eventual impact on meniscal tears in ACL-deficient knees. A total of 107 patients who underwent ACL reconstructive surgery between June 2022 and April 2023 were enroled. After applying exclusion criteria, 37 patients met the conditions for inclusion in the study and formed the ACL deficiency group (Group D). Of the 141 patients presenting to an outpatient clinic who agreed to have ultrasonography conducted on their nondiscomforting contralateral knee, 37 patients matched for age, sex, hip-knee-ankleangleand body mass indexwith Group D patients were selected for the ACL intact group (Group I). Ultrasonography was used to measure MM extrusion in weight-bearing and nonweight-bearing conditions for all participants. Seventy-four patients were included in the study (n = 37 per group). The supine position showed an MM extrusion of 1.2 ± 0.7 mm in Group I and 1.2 ± 0.7 mm in Group D (not significant). In the standing position, MM extrusion measured 2.0 ± 0.6 mm in Group I and 1.3 ± 0.8 mm in Group D. The difference in extrusion (Δextrusion) between the two positions was 0.8 ± 0.6 in Group I and 0.1 ± 0.2 in Group D, with statistical significance (p < 0.01). A consistent reduction in MM extrusion during weight-bearing was observed in patients with ACL deficiency, irrespective of the duration of ACL deficiency, age, sexand BMI. ACL deficiency did not significantly impact MM extrusion during nonweight-bearing conditions; however, less MM extrusion was observed in response to axial loading conditions. These findings indicate altered MM biomechanics due to increased anterior-posteriormeniscal motion and rotational instability after ACL injury. Level III.

In Vitro Assessment of Knee Joint Biomechanics Using a Virtual Anterior Cruciate Ligament Reconstruction.

Understanding the biomechanical impact of injuries and reconstruction of the anterior cruciate ligament (ACL) is vital for improving surgical treatments that restore normal knee function. The purpose of this study was to develop a technique that enables parametric analysis of the effect of the ACL reconstruction (ACLR) in cadaver knees, by replacing its contributions with that of a specimen-specific virtual ACLR that can be enabled, disabled, or modified. Twelve ACLR reconstructed knees were mounted onto a motion simulator. In situ ACLR graft forces were measured using superposition, and these data were used to design specimen-specific virtual ACLRs that would yield the same ligament force-elongation behaviors. Tests were then repeated using the virtual ACLR in place of the real ACLR and following that in ACL deficient knee by disabling the virtual ACLR. In comparison to the ACL deficient state, the virtual ACLRs were able to restore knee stability to the same extent as real ACLRs. The average differences between the anterior tibial translation (ATT) of the virtual ACLR versus the real ACLR were +1.6 ± 0.9 mm (p = 0.4), +2.1 ± 0.4 mm (p = 0.4), and +1.0 ± 0.9 mm (p = 0.4) during Anterior drawer, Lachman and Pivot-shift tests, respectively, which is small in comparison to the full ATT range of motion (ROM) of these knees. Therefore, we conclude that a virtual ACLR can be used in place of real ACLR during biomechanical testing of cadaveric knees. This capability opens the door for future studies that can leverage parameterization of the ACLR for surgical design optimization.

Chronic ACLD Knees with Early Developmental Cartilage Lesions Exhibited Increased Posterior Tibial Translation during Level Walking.

Early articular cartilage lesion (CL) is a vital sign in the onset of posttraumatic knee osteoarthritis (PTOA) in patients with anterior cruciate ligament deficiency (ACLD). Researchers have suggested that altered kinematics could accelerate CLs and, therefore, lead to the onset of PTOA. However, little is known about whether specific knee kinematics exist that lead to early CL in chronic ACLD knees. Level walking is the most frequent and relevant in vivo activity, which greatly impacts knee health. We hypothesized that the knee kinematics during level walking in chronic ACLD knees with early tibiofemoral CL would significantly differ from those of chronic ACLD knees without early tibiofemoral CL. Thirty patients with a chronic ACLD history, including 18 subjects with CLs and 12 subjects without CLs, and 35 healthy control subjects were recruited for the study from July 2020 to August 2022. The knee kinematic data during level walking were collected using a three-dimensional motion analysis system. The kinematic differences between groups were compared using statistical parametric mapping with one dimension for One-Way ANOVA. The cartilage statuses of the ACLD knees were assessed via MRI examination. The CLs distribution of subjects was evaluated using a modified Noyes scale and analyzed by chi-square tests. ACLD knees with CLs had significantly greater posterior tibial translation (7.7-8.0mm, 12%-18% gait cycle GC, p = 0.014) compared to ACLD knees without CLs during level walking. ACLD knees with CLs had greater posterior tibial translation (4.6-5.5mm, 0%-23% GC, p < 0.001; 5.8-8.0mm, 86%-100% GC, p < 0.001) than healthy controls during level walking. In the group of ACLD knees with CLs, CL is mainly located in the back of the tibia plateau and front of load bearing area of the medial femoral condyle (p < 0.05). Chronic anterior cruciate ligament deficient knees with cartilage lesions have increased posterior tibial translation compared to anterior cruciate ligament deficient knees without cartilage lesions and healthy subjects. The posterior tibial translation may play an important role in knee cartilage degeneration in ACLD knees. The increased posterior tibial translation and cartilage lesion characteristics may improve our understanding of the role of knee kinematics in cartilage degeneration and could be a helpful potential reference for anterior cruciate ligament deficient therapy, such as physical training to improve abnormal kinematic behavior.

Evaluating the Diagnostic Performance of MRI for Identification of Meniscal Ramp Lesions in ACL-Deficient Knees: A Systematic Review and Meta-Analysis.

Despite vigorous efforts to delineate the efficacy of magnetic resonance imaging (MRI) for the diagnosis of meniscal ramp lesions, there is still a great deal of uncertainty regarding its diagnostic performance. Therefore, we conducted a systematic review and meta-analysis to investigate the diagnostic performance of MRI for detecting ramp lesions in anterior cruciate ligament (ACL)-deficient knees. We performed a systematic search of MEDLINE via PubMed, Scopus, Web of Science, and Embase and included all articles, published before October 20, 2022, comparing the accuracy of MRI with that of arthroscopy as the gold standard for diagnosis of ramp lesions. We performed statistical analysis using Stata and Meta-DiSc software. Quality assessment of the included studies was performed using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) tool. This meta-analysis evaluated 21 diagnostic performance comparisons from 19 original research articles (2,149 patients). The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the summary receiver operating characteristic (SROC) curve for diagnosing a ramp lesion were 0.70 (95% confidence interval [Cl], 0.66 to 0.73), 0.88 (95% Cl, 0.86 to 0.89), 6.49 (95% Cl, 4.12 to 10.24), 0.36 (95% Cl, 0.28 to 0.46), 24.33 (95% Cl, 12.81 to 46.19), and 0.88, respectively. Meta-regression using different variables yielded the same results. MRI exhibited a DOR of 24.33 and moderate sensitivity, specificity, and accuracy for diagnosing ramp lesions in ACL-deficient knees. However, arthroscopy using a standard anterolateral portal with intercondylar viewing is recommended to confirm a diagnosis of a ramp lesion. Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Anterolateral Ligament and Kaplan Fiber Injury Both Occur Frequently in Acute Anterior Cruciate Ligament-Injured Knees.

The association of ALL and KF injuries in anterior cruciate ligament (ACL)-deficient knees remain topics of conflicting research despite improved magnetic resonance imaging (MRI). We aimed to evaluate the rate of the anterolateral ligament (ALL) and Kaplan fibers (KF) injuries in adults with acute ACL injuries using MRI. We retrospectively reviewed 64 patients with clinical and MRI diagnoses of acute ACL tears. Two radiologists analyzed and categorized the status of the ALL and KF in all patients as intact, partially injured, or completely injured. Interobserver agreement was assessed. Injuries to the collateral ligaments, ITB and posterior cruciate ligament (PCL) were also evaluated. The mean age of the patients was 33 years. ALL injuries were observed in 46 (71%) patients, among whom 33 (71%) had partial and 13 (28%) had complete injuries. KF injuries were identified in 32 (50%) patients, with 28 (87.5%) of them having partial and 4 (12.5%) having complete injuries. Combined injuries of both ALL and KF were found in 25 (32.4%) patients (p-value of 0.266). The agreement between the examiners ranged from moderate to substantial (Kappa between 0.55 and 0.75), with the highest agreement observed in cases of KF injuries (Kappa = 0.75). ALL and KF injuries were prevalent in acute ACL-injured knees with rates of injury of 71% and 50%, respectively. ALL injuries were more frequent and more frequently severe compared to KF injuries.

Femoropatellar alterations in knees with chronic anterior cruciate ligament injuries: a radiographic analysis

Background: The objective of this study was to correlate the occurrence of patellofemoral malalignment in a chronic anterior cruciate ligament (ACL) deficient knee using common radiological parameters. Methods: A case-control study was conducted on 35 adult patients with previously diagnosed unilateral chronic ACL injury. The injured knee was considered as the case, while the contralateral normal knee served as the control. Radiological parameters including the Caton-Deschamps patellar height index, Merchant patellar congruence angle, and Laurin lateral patellar tilt angle were measured on X-rays obtained from both normal and ACL injured knees. A comparative analysis was performed between the two groups. Results: The Caton-Deschamps patellar height index had a mean value of 0.95±0.05 in the ACL-deficient knee. The Merchant patellar congruence angle showed mean values of 12.66±0.84 degrees in the ACL injured knee, while the Laurin lateral patellar tilt angle was 8.06±1.41 degrees in knees with ACL failure. These results indicate lower patellar height, greater lateral displacement of the patella, and increased lateral patellar tilt in knees with chronic ACL tears, thereby affecting the patellofemoral joint. Conclusions: Chronic ACL tears are associated with patellofemoral malalignment, characterized by decreased patellar height, increased lateral displacement of the patella, and greater lateral patellar tilt, thus impacting the patellofemoral joint.

COMPARISON AND FUNCTIONAL ANALYSIS OF SINGLE-BUNDLE ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION ALONE WITH LATERAL EXTRA-ARTICULAR TENODESIS AS AN ADJUNCT TO ANTERIOR CRUCIATE LIGAMENTRE CONSTRUCTION IN ANTEROLATERAL INSTABILITY

Objective: The aim of this study is to compare the functional outcome of ACLR alone, with patients who underwent ACLR with LET.ACL injuries rarely occur in isolation, and associated meniscal, chondral, and ligamentous lesions all influence the outcome of treatment Materials and methods: This prospective study conducted in 30 patients with ACL deficient knee with high grade pivot (grade-II &amp;grade-III) Skeletally mature to 56 years of age , 2 or more of: competitive pivoting sport, Chronic ACL insufficiency, Revision ACLR and Generalized ligament laxity - Beighton score of 4 greater. Results: A total of 30 patients were evaluated in this study.15 cases were operated for ACLR and 15 cases for ACLR + LET. Most of the patients were in the age group of 21-30 with all male gender indicating ACL injuries are common in young males with history of road traffic accident (63.33%) at the time of injury. The mean operating time in our study (also the total tourniquet time) was 110 minutes (range 100 - 130 minutes). Instability was controlled well in ACLR + LET group .Two patients in ACLR+LET group have complained of instability episodes. Preoperatively, Grade 2 pivot shift was observed in 80% in control and 33.33% in other group. Grade 3 pivot shift on examination was found in 20% in control group and 66.66% in experimental group. Post-surgery patients who received ACLR alone had Grade 1 pivot in 60% , Grade 2 in 33.33% and Grade 3 in 6.67%. Combined group (ACLR+LET) had grade 1 in 33.33, Grade 2 in 60% and Grade 3 pivot in 66.66%. Regarding preoperative IKDC scores, patients treated with ACLR alone had 26.66% below 45, 40% between 45-55, 6.66% in 60-70,70-80 and in patients treated with both ACLR+LET had 6.66% in 40-50, 20% in 50-60,46.66% in 60-70, 26.66% in 70-80 before surgery. Post-surgery, patients in both groups had excellent scores (90-100 IKDC score). Conclusions: The combination of LET and intra-articular ACLR is effective in eliminating the high-grade pivot-shift phenomenon. Adding a lateral extra-articular tenodesis can improve patient outcome without the need for future revision ACL surgery and its obligatory intense postoperative rehabilitation, in moderately active patients.

Trends in utilization of meniscal allograft transplantation between 2010 and 2019

ABSTRACT Objectives The aim of this study was to observe the trends in (1) utilization of meniscus allograft transplantation (MAT), (2) demographics and comorbidities of patients undergoing transplants and (3) reimbursements for this procedure between the years of 2010 and 2019. Methods Using a national database, patients who underwent MAT were observed. Incidence of MAT, percentage of female patients, average age, and average Charlson comorbidity index (CCI) were analyzed between 2010 and 2019. Average reimbursement during the index and postoperative 90-day bundle period were also calculated from 2010 to 2019. Compound annual growth rate (CAGR) of change in incidence, demographic and reimbursement was calculated, and linear regressionwas conducted for each trends analysis. Results In total, 744 patients underwent a MAT between the years of 2010 and 2019. The incidence of MAT increased from 0.12 per 100,000 to 0.15 per 100,000 during this period but was not statistically significant (p=0.345). There was no significant difference in age (p=0.462) and gender (p=0.831) among the patients, but the average CCI significantly increased from 2010 to 2019 (CAGR: +15.30; p=0.001). The total reimbursement in the index (p=0.451) and 90-day bundle period (p=0.191) did not significantly change from 2010 to 2019. Conclusions Although MAT has been shown to be a safe and reliable surgery for the treatment of meniscus deficient knees, the incidence of MAT as well as the population undergoing MAT has minimally increased from 2010 to 2019. Future studies should seek to identify why the utilization of this efficacious surgery has not increased. Level of Evidence IV; Descriptive Epidemiology Study

The posterior cruciate ligament-posterior femoral cortex angle (PCL-PCA) and the lateral collateral ligament (LCL) sign are useful parameters to indicate the progression of knee decompensation over time after an ACL injury.

The posterior cruciate ligament-posterior cortex angle (angle between the most vertical part of the anterolateral PCL bundle and the posterior diaphyseal cortex of the femur; PCL-PCA) is the most accurate approach to describe the PCL buckling phenomenon observed in anterior cruciate ligament (ACL)-deficient knees. The aim of this study was to determine whether the PCL-PCA is associated with chronicity of the ACL rupture, the meniscal status, preoperative knee laxity or imaging signs such as the lateral collateral ligament (LCL) sign or the posterior tibial slope (PTS) in ACL-injured knees. Patients with a primary ACL reconstruction (ACLR) after physeal closure were selected retrospectively from a hospital-based ACL registry from 2015 to 2021. Exclusion criteria were: previous ipsilateral/contralateral knee surgery, previous ipsilateral ACL or meniscal tear, ipsilateral PCL and/or collateral ligament injuries or tibial plateau fracture. The ACL deficiency was defined as chronic if time from injury to MRI was > 6months. The meniscal status was assessed during ACLR, separately for the medial and lateral meniscus, and classified into no tear, minor or major unstable tear. The MRI analyses included the assessment of the PCL-PCA and the LCL sign. PTS was assessed from the lateral plain radiographs of the injured knee. The side-to-side difference in anterior tibial translation (ATT) at 200N was obtained with the GNRB. Eighty-two patients (forty-eight males/thirty-four females) were included in this study. The median PCL-PCA was 16.2° (Q1-Q3: 10.6-24.7) and differed between acute (18.4°) and chronic (10.7°) injuries (p < 0.01). The median PCL-PCA was significantly lower (- 4.6°) in patients with a positive LCL sign (p = 0.03) No significant association could be found between PCL-PCA and meniscal status, PTS or preoperative anterior knee laxity (Lachman, pivot shift and ATT in millimetres). The PCL-PCA was significantly lower in chronic ACL injuries and in patients with a positive LCL sign, indicating a higher buckling phenomenon of the PCL in these patients. These results support the fact that PCL-PCA and the LCL sign may be useful parameters to indicate the progression of knee decompensation over time after an ACL injury, and therefore may constitute a helpful tool to optimise treatment choice and timing of ACL reconstruction if necessary. III.

Greater Knee Rotatory Instability After Posterior Meniscocapsular Injury Versus Anterolateral Ligament Injury: A Proposed Mechanism of High-Grade Pivot Shift.

For anterolateral rotatory instability as a result of secondary soft tissue injuries in anterior cruciate ligament (ACL)-deficient knees, there is increasing interest in secondary stabilizers to prevent internal rotation (IR) of the tibia. To determine which secondary stabilizer is more important in anterolateral rotatory instability in ACL-deficient knees. Controlled laboratory study. The lower extremities of 10 fresh-frozen cadavers (20 extremities) without anterior-posterior or rotational instability were included. Matched-pair randomization was performed, with each side per specimen assigned to 1 of 2 groups. In group 1, the ACL was sectioned, followed by the anterolateral ligament (ALL); in group 2, the ACL was sectioned, followed by sequential sectioning of the posterolateral meniscocapsular complex (PLMCC) and posteromedial meniscocapsular complex (PMMCC). The primary outcome was the change in relative tibial IR during a simulated pivot-shift test with 5 N·m of IR torque and 8.9 N of valgus force. The secondary outcomes were the International Knee Documentation Committee grade in the pivot-shift test and the incidence of the grade 3 pivot shift. In group 1, compared with baseline, the change in relative tibial IR at 0° of knee flexion was 1.4° (95% CI, -0.1° to 2.9°; P = .052) after ALL release. In group 2, it was 2.5° (95% CI, 0.4° to 4.8°; P = .007) after PLMCC release and 4.1° (95% CI, 0.5° to 7.8°; P = .017) after combined PLMCC and PMMCC release. Combined PLMCC and PMMCC release resulted in greater change of tibial IR with statistical significance at 0°, 15°, and 30° of knee flexion (P = .008, .057, and .004, respectively) compared with ALL release. The incidence of grade 3 pivot shifts was 10% in group 1 and 90% in group 2. Posterior meniscocapsular laxity caused an increase in relative tibial IR as much as ALL injury in ACL-deficient knees in our simulated laboratory test, and greater anterolateral rotatory instability occurred with posterior meniscocapsular injury compared with ALL injury. Repair of the injured posterior meniscocapsular complex may be an important treatment option for reducing anterolateral rotatory instability in the ACL-deficient knee.

Poster 349: Outcomes Following ACL Reconstruction with Concomitant Meniscus Allograft Transplantation Versus Isolated ACL Reconstruction

Objectives: Meniscus allograft transplantation (MAT) is used in the setting of ACL reconstruction to restore proper arthrokinematics and load distribution for the meniscus deficient knee. Objective outcomes following ACL reconstruction with concomitant MAT in athletic populations are scarcely reported and highly variable. Thus, the purpose of this study was to compare patient outcomes using an objective functional performance battery, self-reported outcomes, and return to activity rates between individuals undergoing an ACL reconstruction with concomitant MAT and the outcomes of patients undergoing isolated ACL reconstruction. We hypothesized that patients in the ACL reconstruction with MAT group would exhibit lower performance on objective functional tests, delayed time to release to activity, and lower return to activity rates when compared to those undergoing isolated ACL reconstruction. Methods: A single surgeon ACL database (n = 1,431) was utilized to identify patients undergoing ACL reconstruction with concomitant MAT from 2014-2019. A comparison group undergoing an isolated ACL reconstruction were identified to serve as a known control. Baseline patient and surgical demographics data were collected. Patients completed an objective functional performance battery at the time of return to activity which included range of motion (ROM), single leg squat performance, single leg hop test performance, subjective function (International Knee Documentation Committee score (IKDC)), and psychological readiness (ACL Return to Sports After Injury scale (ACL-RSI). Between limb comparisons were assessed using limb symmetry indices (LSI). Injury surveillance was conducted for two-years and included the Single Assessment Numeric Evaluation (SANE), re-injury rates, complications, and current level of sports participation. Between group comparisons at time of return to activity and two years were analyzed using generalized linear models utilizing an a-priori alpha level of .05. Results: Forty-four patients were included in the ACL reconstruction with concomitant MAT group along with 45 in the isolated ACL reconstruction group (Figure 1). Baseline demographic differences existed between groups with the MAT group being significantly older ( P=.001), having a higher BMI ( P=.001), and a lower MARX score (p=.001) (Table 1). The MAT group had a significantly delayed release to activity timeline (10.8 ±3.2mo vs 7.8 ±1.8mo, P = .001) and reported significantly lower IKDC scores (82.4 ±13.8 vs 93.7 ±10.1, P = .001) and ACL-RSI scores (62.8 ±21.3 vs 80.3 ±9.7, P = .001) at time of release to activity (Table 2). Likewise, the MAT group had significantly greater flexion ROM deficits (6.4 ±5.6 deg. vs 3.0 ±2.6 deg., P = .011) and lower single-leg hop symmetry (90.2 ±12.3% vs 97.1 ±5.3%, P = .001). At two- year follow-up the MAT group also demonstrated a significantly lower return to activity rate (69.7% vs 95%, P=.001), lower rate of participation in Level 1 sports (9.1% vs 63.3%, P=.001), and lower SANE scores (80.9 ±16.1 vs 92.5 ±8.3, P = .001) (Table 3). No significant differences existed between groups for ACL graft re-injury rates. Conclusions: The majority of patients undergoing ACL reconstruction with concomitant MAT are able to return to at least level 3 sports at two years post-surgery with low risk of graft re-injury. Patients receiving a concomitant MAT exhibit lower return to sport rates, delayed time to release to activity, and lower subjective function compared to those undergoing an isolated ACL reconstruction. Clinicians should consider patient expectations, surgical demographics, functional outcomes, extended rehabilitation timelines, and lower return to activity rates when counseling patients return to activity following ACL reconstruction with MAT. [Table: see text][Table: see text][Table: see text]

Poster 313: More Severe Adverse Events are Associated with Worse Patient Reported Outcome Measures following Anterior Cruciate Ligament Reconstruction with and without Lateral Extra- articular Tenodesis Augmentation – Results from the Stability Randomized Trial

Objectives: Investigate how the severity of adverse events encountered during the follow up period of the Stability Study were associated with patient reported outcomes at two years post-operative. Methods: Stability is a pragmatic, multicenter, randomized clinical trial comparing single-bundle hamstring tendon ACLR with combined ACLR + LET. Patients aged 14-25 years with an ACL deficient knee were included (n = 618). Participants completed PROMs (KOOS, IKDC, ACL-QOL), and adverse events were documented pre-operatively and at 3, 6, 12 and 24 months postoperatively. Adverse events were categorized into four groups: none (no adverse event), minor medical (resolved spontaneously or with minimum medical management), minor surgical (event such as meniscus tear or stiffness that required surgical intervention but is not a graft rupture), contralateral ACL rupture, and graft rupture. A generalized linear model was used to compare mean PROM scores with the different levels of adverse events. Results: The rate of minor medical adverse events (11.2%), minor surgical adverse events (7.4%), and ipsilateral (7%) or contralateral (3%) ACL tears at 24 months post-operative were low considering the high-risk patient profile. There was no difference in the proportion of minor medical events, minor surgical events, or contralateral ACL ruptures between the ACLR only and ACLR + LET groups (p&gt;0.05). The ACLR only group had a significantly higher rate of graft rupture (11 vs 4%, p&lt;0.01). Increasing severity of adverse events were associated with lower PROM scores at 24 months post-operative. Patients who experienced any adverse event within the two-year follow up had significantly lower outcome scores than those with no events. When only adverse events in the first year post-operative were included, the influence of minor medical and minor surgical events was largely washed out suggesting the effect on outcomes may be due to recency rather than severity. However, graft tears and contralateral ACL tears within the first year led to significantly lower scores at two-years post-operative in all outcomes (p&lt;0.01). Conclusions: Increasing severity of adverse events were associated with lower patient reported outcome measures at 2 years post-operative. Recent minor medical and minor surgical events worsened PROM scores, but this effect was largely eliminated within a year of the event. Patients who experience a graft rupture or contralateral ACL tear appear to have a significantly lower PROMs at 2 years post- operative, regardless of the time at which the tear occurs. Therefore, the benefit of the LET procedure reducing graft rupture outweighs the potential for less severe events such as hardware irritation/removal which will likely be less detrimental to patient-important outcomes.

Ostéotomie tibiale biplanaire proximale pour la correction combinée du varus et des anomalies de la pente tibiale postérieure

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.

Repair of Ramp Lesions of the Medial Meniscus With ACL Reconstruction Can Better Restore Knee Stability: A Cadaveric Study.

Ramp lesions of the medial meniscus have an impact on joint stability in anterior cruciate ligament (ACL)-deficient knees, but the impact of lesion length and repair is unclear. The purpose of this cadaveric study was to evaluate the effect of medial meniscal ramp lesion repair on the biomechanics of ACL-deficient knee joints. It was hypothesized that (1) ramp lesions will increase the anterior tibial translation (ATT), internal rotation (IR), and external rotation (ER) in ACL-deficient knee joints; (2) increasing the length of the ramp lesion will further increase the ATT, IR, and ER; and (3) repairing the ramp lesion will reduce the ATT, IR, and ER after ACL reconstruction. Controlled laboratory study. Included were 9 fresh-frozen cadaveric specimens (4 left knees, 5 right knees; 6 males and 3 females; mean age, 60 years [range, 40-73 years]). The specimens were tested on a biomechanical rig. Two external loading conditions were applied: a 134-N anterior tibial load and 5-N·m internal/external tibial torque with the knee at full extension and at 15°, 30°, 60°, and 90° of flexion. ATT was tracked via a high-speed video camera. The following knee states were tested: intact; ACL-deficient; ACL-deficient combined with a 5-, 10-, 15-, or 20 mm-long ramp lesion of the medial meniscus; ACL reconstruction; and ACL reconstruction combined with ramp lesion repair. The ATT, IR, and ER at all knee angles were analyzed by 1-way analysis of variance. The ATT, IR, and ER were significantly increased after cutting of the ACL (P < .05). The ATT, IR, and ER continued to increase when ACL deficiency was combined with ramp lesions of 5 to 20 mm in length (P < .05). The ATT, IR, and ER significantly decreased after ACL reconstruction and ACL reconstruction combined with ramp lesion repair (P < .05). The laxity of knees with ACL deficiency combined with a ramp lesion of the medial meniscus increased more obviously as the ramp lesion increased in length. In a cadaveric model, ACL reconstruction combined with ramp repair improved knee joint stability.

A prospective study of joint position sense after anterior cruciate ligament injury, reconstruction with a bone-patella tendon-bone graft, and rehabilitation

BackgroundDisruption of the anterior cruciate ligament (ACL) is associated with significant biomechanical and neuromuscular changes including deficits in joint proprioception. While previous studies have assessed joint position sense (JPS) in ACL deficient knees, methods have varied and few have done so with prospective study designs. The specific aim of this investigation was to determine the effect(s) of ACL reconstruction and recovery time may have on JPS. MethodsIn this prospective study, we assess the effects of ACL reconstruction and rehabilitation on joint position sense in a temporal study. Twelve patients with unilateral ACL injuries were assessed pre-operatively and at 2, 4, 8 months post-op. JPS measurements were performed, while the subject was standing, with passive-active (P-A) and active-active (A-A) tests. Comparisons between the injured/reconstructed and contralateral, uninjured knee were evaluated in terms of real and absolute mean errors. ResultsThere were no statistically significant differences between the injured/reconstructed and contralateral/normal side with P-A or A-A testing at 2, 4, or 8 months. ConclusionWe conclude that there is no difference in joint position sense between the injured and contralateral leg after ACL disruption and reconstruction beginning as early as 2 months post-op. This study provides further evidence that knee proprioception is not altered by ACL injury and reconstruction. Level of evidence: II.

Isolated lateral extra-articular tenodesis in ACL-deficient knees: in vivo knee kinematics and clinical outcomes.

To carry out an in vivo kinematic analysis of isolated modified Lemaire lateral extra-articular tenodesis (LET) to explore its ability to modify the stability of anterior cruciate ligament (ACL) deficient knees. The secondary aim was to look at the clinical outcomes of the isolated LET to analyze whether biomechanical changes have an influence on clinical improvement or not. A total of 52 patients who underwent an isolated modified Lemaire LET were prospectively studied. Twenty-two were over 55-year-old patients with ACL rupture and subjective instability (group 1). They were followed up for 2years postoperatively. Thirty were patients underwent a two-stage ACL revision (group 2). They were followed up for 4months postoperatively (up to the second stage of the ACL revision). Preoperative, intraoperative, and postoperative kinematic analyses were carried out using the KiRA accelerometer and KT1000 arthrometer to look for residual anterolateral rotational instability and residual anteroposterior instability. Functional outcomes were measured with the single-leg vertical jump test (SLVJT) and the single-leg hop test (SLHT). Clinical outcomes were evaluated using the IKDC 2000, Lysholm, and Tegner scores. A significant reduction of both rotational and anteroposterior instability was detected. It was present both with the patient under anesthesia (p < 0.001 and p = 0.007 respectively) as well as with the patient awake (p = 0.008 and p = 0.018 respectively). Postoperative analysis of knee laxity did not show any significant variation from the first to the last follow-up. Both the SLVJT and SLHT improved significantly at the last follow-up (p < 0.001 and p = 0.011 respectively). The mean values of both the IKDC and Lysholm and Tegner scores showed an improvement (p = 0.008; p = 0.012; p < 0.001). The modified Lemaire LET improves the kinematics of ACL-deficient knees. The improvement in the kinematics leads to an improvement in subjective stability as well as in the function of the knee and in the clinical outcomes. At the 2-year follow-up, these improvements were maintained in a cohort of patients over 55years. Following our findings, to reduce knee instability, an isolated LET in ACL-deficient knees may be used when ACL reconstruction in patients over 55years is not indicated. Level IV.