Anterior Cruciate Ligament Deficiency Research Articles

Changes in the Elongation Pattern of the Medial Collateral Ligament During a Single-Leg Squat After Anterior Cruciate Ligament Reconstruction.

An anterior cruciate ligament (ACL) tear impairs knee biomechanics in daily activities and potentially breaks the synergy among other knee ligaments. Previous studies have demonstrated that the biomechanics of collateral ligaments is influenced by ACL deficiency. To investigate changes in the elongation patterns of the medial collateral ligament (MCL), lateral collateral ligament (LCL), and posterior cruciate ligament (PCL) during the execution of a single-leg squat before and after ACL reconstruction. Descriptive laboratory study. A total of 16 patients (mean age, 24.9 ± 8.5 years) with ACL deficiency were enrolled in the study. Magnetic resonance imaging scans of the affected knees were used to produce 3-dimensional models of the tibia and femur and identify insertion sites of the MCL, LCL, and PCL. Motion capture of a single-leg squat was performed through a biplanar radiographic system. Data were acquired before ACL reconstruction and at a minimum of 18 months (mean, 22.9 ± 4.1 months) postoperatively. The centroids of the ligaments' insertions were used to calculate the length of the investigated structures during the squat task. Absolute length (L), absolute length increase from the orthostatic resting position (ΔL), and relative length increase (ΔL%) were computed for each ligament, and preoperative and postoperative data were compared using the paired Student t test. The intraclass correlation coefficient was used to determine the reliability of the ligament insertion's identification and kinematics between 2 independent observers. Significant differences were found for the MCL in absolute length increase (P = .047; Cohen d = 0.60) and relative length increase (P = .043; Cohen d = 0.61) from rest between preoperatively and postoperatively (ΔL pre = 1.0 mm; ΔL post = -1.1 mm; difference = 2.1 mm) at 0° to 30° of knee flexion during the descending phase of the single-leg squat. No differences were seen in the elongation patterns of the LCL or PCL from before to after ACL reconstruction. The MCL was significantly longer between 0° and 30° in ACL-deficient knees compared with ACL-reconstructed knees during the descending phase of a single-leg squat. No differences were identified for the LCL or PCL. Early ACL reconstruction could have a protective effect on the MCL in combined ACL and MCL lesions.

Functional Outcomes in ACL Reconstruction: A Randomized Controlled Trial Comparing All-Inside and Transportal Techniques.

The two techniques to fix a torn ACL are the Transportal and All-Inside Techniques. However, the argument about which method is better for functional outcomes keeps going on. The aim was to look at how well these two treatments worked and their effects. We hypothesized that All-Inside and Transportal ACL reconstruction procedures would yield similar functional results. The study included 45 patients with ACL insufficiency from AIIMS, Raipur, India. Half of each ACL approach was represented by 22 AI and 23 TP participants, randomly assigned to each group. Preoperative and post-operative VAS, IKDC, and range of motion were determined at 1, 3, and 6 months. The study used IBM SPSS v20 for Data Analysis, comparing two groups using a t-test. P < 0.05 was fixed for Statistical significance. The study was dominated by young males (86.7%, 18-30 years), mainly students (44.4%). Comparable IKDC scores over time (P = 0.628); significant VAS score difference (P = 0.001). A similar movement range (P = 0.153) was observed. AI group had slightly smaller grafts (non-significant, P = 0.235). Similar Lachmann Grade distributions pre- and post-surgery; no significant post-operative complication in either group. When comparing the methods' functionalities, no statistically significant gaps emerged. All-Inside approach preserves bone and gracilis tendon, reduces post-operative pain, and strengthens knee flexors. Although, early rehabilitation favors all inside, both methods are equally effective over time. In comparison to the traditional Transportal Technique, All Inside has a greater learning curve and costs more.

ANTERIOR CRUCIATE LIGAMENT RUPTURE DISGUISED AS PATELLAR INSTABILITY: A COMMON MISS

Patellar dislocation is a common presentation with a clear management pathway. Sometimes, however, what a patient experiences as the patella dislocating may, in fact, be ACL insufficiency.We reviewed case notes and imaging of 315 consecutive ACL reconstructions, collecting data on the date and mechanism of injury, time to MRI, and reconstruction. We noted cases initially diagnosed as patellar dislocation.25 of 315 (7.9%) patients were initially diagnosed with a patellar dislocation. Subsequently, however, MRI scans revealed no evidence of patellar dislocation and instead showed ACL rupture with pathognomonic pivot-shift bony oedema. The false patella dislocation group were 32% female and had an average age of 25; the rest of the group average age was 27.1 and there were a lower proportion of females; 21%. The false patella instability patients had a median waiting time of 412 days from injury to operation (range: 70-2445 days), compared to 392 days (range: 9 – 4212 days) for rest of the patients. 5 of the remaining 290 had MRIs showing patella oedema with medial patello-femoral ligament injury in addition to their ACL rupture.From our literature search this is a new finding which shows that ACL rupture can present with symptoms suggestive of patellar dislocation. These findings raise the risk that there are a group of people who have been diagnosed with patellar instability who instead have ACL insufficiency and so are at risk of meniscal and chondral damage. Further research should analyse those diagnosed with patellar instability to quantify missed ACL injuries.

Guided Growth for Correction of Elevated Tibial Posterior Slope in Pediatric ACL Deficiency: A Case Report.

Fourteen-year-old boy, history of autism presented with bilateral knee instability. Imaging revealed bilateral anterior cruciate ligament (ACL) insufficiency, 20° of posterior tibial slope (PTS) on the right and 18° on the left. A guided growth technique using anterior placed tension band plates was used to correct the PTS. At 22 months, the PTS corrected to 5.5° on the right and 6° on the left. The patient's knee stability improved, and he resumed activities at 30 months. Pediatric ACL insufficiency in the setting of elevated PTS can be successfully corrected with a guided growth technique.

Factors Associated With a Successful Return to Performance After Anterior Cruciate Ligament Reconstruction: A Multiparametric Evaluation in Soccer Players.

Anterior cruciate ligament reconstruction (ACLR) is highly recommended in patients with ACL deficiency who must perform at a high physical level. A combination of functional and psychological outcome measures is necessary to provide a comprehensive evaluation of functional status after successful return to sport after ACLR. To identify factors associated with higher functional outcomes among soccer players who had returned to full sports participation after ACLR. Cohort study; Level of evidence, 3. A total of 168 out of 231 patients who underwent primary unilateral arthroscopic anatomic single-bundle ACLR were available at follow-up. Postoperatively, knee function, generic health outcomes, and psychological impact were assessed using the International Knee Documentation Committee (IKDC), the Knee injury and Osteoarthritis Outcome Score (KOOS), the Lysholm Knee Scoring Scale, the 12-item Short Form Health Survey (SF-12), and the ACL-Return to Sport after Injury scale. After a mean follow-up of 35.5 ± 22.6 months, 85% of soccer players returned to performance. Midfielder position was associated with a better SF-12 Physical Component Summary (PCS) score (P = .013), IKDC (P = .003), total KOOS (P < .001), KOOS Symptoms (P = .004), KOOS Pain (P = .029), KOOS Activities of Daily Living (ADL) (P = .044), KOOS Sport and Recreation (Sport/Rec) (P = .001), KOOS Quality of Life (QoL) (P < .001), and Lysholm score (P = .008). Playing only on natural grass was associated with lower SF-12 PCS scores (P = .003), total KOOS (P = .001), and KOOS Sport/Rec (P = .011). Playing only on artificial turf was associated with lower Lysholm score (P = .018) and total KOOS (P = .014). The contact mechanism was associated with higher IKDC (P = .044) and KOOS QoL (P = .048), and injury affecting the dominant limb was associated with lower SF-12 Mental Component Summary scores (P = .012). Playing at a nonprofessional level was associated with lower total KOOS (P = .028), KOOS Symptoms (P = .002), KOOS ADL (P = .033), and KOOS Sport/Rec (P = .016). Professional soccer players and the midfielder position are associated with better functional scores upon returning to the sport. A history of noncontact ACL injury and playing on a single type of surface are associated with lower functional outcomes upon returning to the sport. Lower mental health scores can be expected after injury of the dominant limb.

Redistribution Of Inter-joint Sharing Of The Total Support Moment During Uphill Walking In ACL Deficiency

Redistribution Of Inter-joint Sharing Of The Total Support Moment During Uphill Walking In ACL Deficiency

English Translation and Cultural Adaptation of the Knee Numeric-Entity Evaluation Score (KNEES-ACL): A Condition-Specific Patient-Reported Outcome Measure for Anterior Cruciate Ligament Injuries

Background: The Knee Numeric-Entity Evaluation Score (KNEES-ACL) is a 41-item condition-specific patient-reported outcome measure (PROM) that was developed for patients with an anterior cruciate ligament (ACL) deficiency and patients after ACL reconstruction. This measure is intended to be used for longitudinal clinical studies. The KNEES-ACL has demonstrated face and content validity and superior responsiveness compared with other PROMs commonly used in patients with an ACL injury. However, this PROM was developed in Danish and has not been appropriately translated and culturally adapted into North American English. Purpose: To translate and culturally adapt the KNEES-ACL from Danish to North American English. Study Design: Cross-sectional study. Methods: Translation from Danish to English and cultural adaptation to a North American context were performed according to the dual panel method. First, the Danish KNEES-ACL was translated by a bilingual panel, which provided multiple English wording options for each item. Second, an English lay panel focus group was formed to determine the wording for each item that best reflected everyday spoken language. Finally, individual think-aloud cognitive interviews were conducted with patients after an ACL injury to evaluate the relevance, comprehensiveness, and comprehensibility of the PROM content and questions. Repeated modifications and testing were performed until a final English version of the KNEES-ACL was constructed. Results: Participants in the lay panel focus group were able to reach unanimous decisions for each of the 41 items. Further changes to 17 items were made after 8 think-aloud interviews with patients with ACL injuries at various time points to ensure that items were relevant and being interpreted consistently among different types of patients. The final KNEES-ACL consisted of 6 domains: Problems with Daily Activities, Mental Impact, Stability, Strength and Control, Pain, and Sport and Physical Activity. Conclusion: The English KNEES-ACL for patients with ACL injuries has undergone appropriate translation and cultural adaptation using established dual panel and cognitive interviewing methods in the population of interest. The psychometric properties of the English KNEES-ACL will likely mirror those established with the Danish version. However, direct validation of the psychometric properties of the English version would be beneficial before widespread use.

Younger age, longer delay to surgery and meniscal tears are associated with a smaller ACL remnant: An analysis from the registry of the Francophone Arthroscopic Society

AbstractPurposeThis study aimed to evaluate which preoperative patient, injury or clinical factors were associated with the anterior cruciate ligament (ACL) remnant volume in patients undergoing ACL surgery. It was hypothesized that the main factors determining an insufficient ACL remnant volume at the time of surgery were younger age and longer time to surgery.MethodsA retrospective analysis from the Francophone Arthroscopic Society's registry was conducted, including 1565 patients with an ACL lesion underdoing a primary ACL surgery (reconstruction or repair) between June 2020 and June 2023. Patients were excluded in case of revision surgery and incomplete data. Preoperative factors—including patient demographics, delay to surgery, preoperative laxity and the presence of meniscal tears or cartilage lesions—were analysed to determine their influence on ACL remnant volume (estimated by the surgeon as the percentage of residual volume). Univariate, multivariate and receiver operating characteristic curve analyses were performed to explore these relationships.ResultsMultivariate analyses demonstrated that younger age (&lt;20 years and 20–30 years compared to ≥40, p = 0.02), higher time from injury to surgery (≥12 months compared to &lt;3 months, p = 0.01) and the presence of a medial (p = 0.01) or a lateral meniscal tear (p = 0.02) were significant predictors of an ACL remnant volume ≤ 50%.ConclusionsYounger age (under 30 years of age), a time from injury to surgery above 12 months and the presence of medial and lateral meniscal tears are associated with higher odds of observing a smaller ACL remnant volume at the time of the ACL surgery. These factors should be considered when planning ACL remnant preservation techniques.Level of evidenceLevel III.

Anterior Cruciate Ligament Reconstruction Utilizing Double Adjustable-Loop Suspensory Fixation Devices Provides Good Clinical Outcomes in Patients under the Age of 40 Years at Two-Year Follow-Up.

Background: Anterior cruciate ligament reconstruction (ACLR) using double adjustable fixation gained popularity in the last decade due to its minimally invasive technique. However, suspensory fixation devices could be related to recurrent instability, poor clinical outcomes, and patient dissatisfaction. The present study aims to evaluate the clinical outcomes following ACLR using double adjustable-loop suspensory fixation devices in the demanding population of young patients. Methods: Between 2019 and 2022, 95 patients with knee post-traumatic anterior cruciate ligament insufficiency were treated with primary ACLR using semitendinosus quadrupled graft and double adjustable-loop suspensory fixation devices and followed for at least two years. Concomitant lesions were also treated at the same surgical time. The knee examination form of the International Knee Documentation Committee (IKDC) was used to assess clinical evaluation, and the return to physical activities using the Tegner Activity Scale was recorded. Patient-reported objective measures (PROMs) were also evaluated, including the IKDC subjective and Lysholm scores. Results: Sixty-six males and twenty-nine females with a mean age of 23.8 (range 18-37) and a mean BMI of 24.9 (SD ± 2.42) kg/m2 were included in this study. All patients were evaluated clinically as normal or nearly normal at the final follow-up. PROMs also significantly improved postoperatively (p < 0.05) compared to the preoperative values. The Tegner Activity Scale increased from 2 to 7, the IKDC mean score improved from 43.9 (±8.9) to 93.3 (±12.3), and the modified Lysholm from 47.3 (±11.1) to 92.9 (±16.6). No complications or adverse events were recorded. Conclusions: Anterior cruciate ligament reconstruction utilizing double adjustable-loop suspensory fixation devices provides good clinical and functional outcomes in young patients at a two-year follow-up.

Longitudinal assessment of knee joint proprioception using weight-bearing and non-weight-bearing tests throughout rehabilitation after anterior cruciate ligament reconstruction

ObjectiveEvaluate active knee joint position sense (JPS) throughout rehabilitation after anterior cruciate ligament reconstruction (ACLR). DesignLongitudinal. SettingMotion laboratory. ParticipantsTwenty-two individuals post-ACLR and 22 activity-matched non-injured controls performed weight-bearing and non-weight-bearing knee JPS tests. The ACLR participants performed at three functional timepoints: T1, able to perform single-leg sit-to-stand; T2, able to hop maximally; T3, cleared for return to sports. Controls performed on one occasion. Main outcome measuresConstant, absolute, variable errors (CE, AE, VE) and interlimb symmetry estimates (100% signifying perfect symmetry), for 40° and 65° knee flexion target angles. ResultsFor the weight-bearing 40° condition, CE and AE of the ACLR knee significantly increased from T1 to T2 (P = 0.010) and T1 to T3 (P = 0.002). Consequently, interlimb asymmetry for AE significantly increased from T1 (AEsym% = 101.2% ± 55.4%) to T3 (AEsym% = 139.7% ± 54.8%). Compared to controls, AE for the ACLR knee was significantly smaller at T1 (P = 0.016). No other significant differences were observed. ConclusionsSmaller JPS errors at early rehabilitation while weight-bearing may have been due to heightened quadriceps activation and increased γ motor neuron sensitivity, compensating for deficient ACL mechanoreceptors. In contrast, non-weight-bearing testing did not reveal changes over time. Clinicians are advised to consider these distinctions when assessing proprioception at different rehabilitation stages.

Is Visual Reliance Increased in Athletes After ACL Injury? A Scoping Review.

Individuals with anterior cruciate ligament (ACL) injury often exhibit visual cognitive deficits during tasks that require neuromuscular control. In this paper, we present evidence of increased visual reliance after ACL injury during a range of clinically applicable cognitive-motor tasks. This information is essential to strengthen the scientific rationale for therapeutic interventions that target maladaptive neuroplasticity and may translate to improved return-to-sport (RTS) outcomes following ACL injury. The objectives of this study are (1) to determine if visual reliance is present during common rehabilitation-based assessments after ACL deficiency (ACL-D) or ACL reconstruction (ACL-R), (2) to describe how visual reliance is assessed during such tasks, and (3) to provide information to help clinicians and patients understand the clinical relevance of cognitive load in the assessment and intervention of visual reliance. Scoping review. We searched MEDLINE, EMBASE, CINAHL, SCOPUS, and PEDro databases. Only primary studies published in English were included without time limitations. Qualitative analysis of the included studies was performed. We synthesized the results of 23 studies. A total of 7 studies (31%) included patients with ACL-D, 15 studies (65%) included patients with ACL-R, and 1 study (4%) included patients with ACL-D and ACL-R. Evaluation of tasks, task evaluation setting, visual conditions, outcome measures, and presence of increased visual reliance were identified. Most studies investigating patients with ACL-D, contrary to those with ACL-R, exhibited worse postural stability during eyes-closed conditions than uninjured controls. Complete visual obstruction (i.e., eyes closed or blindfolded) was the most frequently reported method to disrupt vision (52%). The addition of a visual-cognitive challenge resulted in significantly worse postural stability in patients with ACL-R compared with controls. Visual reliance was most commonly assessed during single leg stance with complete visual obstruction. The majority of studies on patients with ACL-D indicate that they exhibit poorer postural stability in eyes-closed conditions when compared with uninjured controls, which suggests increased visual reliance. There is less evidence of visual reliance in patients who have undergone ACL-R compared with those with ACL-D. Adding a visual-cognitive load was found to be more effective in inducing postural stability deficits in individuals who have undergone ACL-R. IV. The protocol was a priori registered on Open Science Framework ( https://osf.io/p4j95/ ).

Health-related quality of life for children with anterior cruciate ligament deficiency: Ensuring content validity of the new KIDS-KNEES-ACL questionnaire.

The existing knee-specific pediatric patient-reported outcome measures (PROMs) lack content and construct validity for children with anterior cruciate ligament (ACL) injury. This impairs their accuracy which can lead to false interpretations of data and inaccurate clinical guidelines. The purpose of this study was to develop a content-valid PROM for children with an ACL injury. The process adhered to the COnsensus-based Standards for the selection of health Measurement INstruments guidelines for PROM development. Informants were children with ACL deficiency and sampled based on age, sex, and treatment. Semistructured interviews were conducted exploring themes within the International Classification of Functioning, Disability and Health model. Interviews continued beyond data saturation. By thematic analysis and by probing items from the adult PROM 'KNEES-ACL', new themes and items emerged. Content coverage, relevance and understandability were continuously evaluated. All interviews were recorded and transcribed verbatim. The NVivo 12 software was used for data analysis and coding of items. A PROM of 60 items across nine subscales was formed. From cognitive interviews, 19 new items emerged. Forty-one of 55 items from KNEES-ACL were endorsed as relevant; however, all required rewording to ensure understandability. Substantial differences in the psychosocial impact between adults and children were observed. The children experienced a more considerable negative psychosocial impact caused by a loss of participation in sports, lower self-confidence and loss of social networks. This resulted in four new domains. The physical issues were similar to adults, with few exceptions. The 'KIDS-KNEES-ACL' 1.0 (qualitative version) was developed. This version will be subjected to psychometric analysis, resulting in adequate measurement properties of the final KIDS-KNEES-ACL 2.0. As the only adequate pediatric ACL-specific PROM, its use in clinical trials and databases will enhance PROM data quality, and strengthen clinical guidelines and thus the treatment of children with ACL injury. Not applicable.

The Stabilized Lachman’s Test: A Highly Sensitive, Specific and Accurate Test to Diagnose Acute ACL Tears

Background The Lachman’s Test (LT) is the one of the most relied tests for the clinical diagnosis of a torn Anterior Cruciate Ligament (ACL). The accuracy of the traditional LT is largely dependent on the skill and experience of the observer as well as the timing of the knee was examined in respect to the injury. Wroble &amp; Linderfeld first described the stabilized Lachman’s Test (SLT) in 1988. The examiner’s thigh is placed underneath and supports the thigh while the examiner’s hand (the opposite one to the extremity being examined) is used to stabilize the thigh. Purpose The purpose of this study was to prospectively analyze the sensitivity, specificity, and accuracy of the SLT to diagnose acute ACL tears. The hypothesis is that the SLT is a very sensitive, specific, and accurate test to diagnose ACL deficiency in acutely injured knees. Methods Two hundred patients with acute knee injuries were prospectively studied. All were examined within 30 days of injury (average – 8.3 days). Any patients with a previous ipsilateral or contralateral ligament knee injury were excluded from this study. All knees were examined prior to examining or interviewing the patient. There were 83 (41.5%) females and 117 (58.5%) males with an average age of 27.3 years. The SLT results were not graded but recorded as a positive or negative result. ACL tears were definitively diagnosed with MRI. Results On the initial examination there were 46 (23%) patients that had SLT that was recorded as positive and 154 (77%) that were considered negative. Forty-eight patients (24%) had a torn ACL and in 152 (76%) knees, the ACL was found to be intact by MRI. The SLT produced 44 (22%) true positives and 150 (75%) true negatives as well as 4 (2%) false negatives and 2 (1%) false positives. The resulting sensitivity was 91.7%, specificity was 98.7% and accuracy was 97%. The positive predictive value was 95.7% with the negative predictive value of 97.0%. The positive likelihood ratio was 69.9 and the negative likelihood ration was 0.085 Discussion The SLT is a highly sensitive, specific and accurate test for diagnosing ACL tears in the knee. The advantage of the SLT is that it allows the patient to relax the leg easily because the thigh is resting on a stable object. The examiner will feel the lower extremity relax by increased pressure on their own thigh and as soon as they feel this the SLT is performed. The examiner’s hand can now easily stabilize the thigh and control the leg’s rotation even in patients with large thighs or with clinicians with smaller hands, thus increasing the reliability and reproducibility of the SLT. Conclusion The SLT is highly sensitive, specific and accurate and has advantages over the standard LT. The SLT is a valuable tool in the armament of the clinician’s physical exam and diagnostic testing. It is beneficial for clinicians to at least try and compare it to the standard LT, especially those with less clinical experience.

Modified MacIntosh (Over-the-Top Iliotibial Band Autograft) Technique for Pediatric Anterior Cruciate Ligament Reconstruction Using Knotless All-Suture Anchor Fixation

Anterior cruciate ligament (ACL) injury is a significant cause of injury among pediatric patients with an increasing incidence. ACL insufficiency can lead to lifelong disability as further joint deterioration occurs in the form of meniscal and subsequently chondral pathology. Techniques for pediatric ACL reconstruction can broadly be classified as physeal-sparing and non–physeal-sparing. Bone age is frequently used when deciding which technique to employ. Patients are candidates for physeal-sparing, over-the-top iliotibial band reconstruction (i.e., modified MacIntosh II) when they have >4 years remaining before skeletal maturity. The modified Macintosh procedure provides both intra- and extra-articular rotational and translational constraint. This Technical Note describes the senior author’s modified MacIntosh technique using knotless all-suture anchor fixation in a suture staple technique to mitigate risk of physeal damage.

Altered dynamic joint space in the lateral condyle compartment following medial unicompartmental knee arthroplasty

PurposeThe progression of osteoarthritis in lateral compartment has been identified as a primary complication in medial unicompartmental knee arthroplasty (UKA) revisions, irrespective of whether employing fixed bearing (FB) or mobile bearing (MB) designs. Compared to the previous contact point analyses, the tibiofemoral contacts during knee movements are comprehended by a more comprehensive understanding of joint spaces. This study aims to dynamically map the joint spaces in the lateral compartment during the single-leg lunge following FB and MB UKA procedures, and compare them with the respective contralateral native knees. It is hypothesized that the significant change in joint space for post-UKA compared to their native knees. MethodsTwelve patients with unilateral medial FB UKA and eleven patients with unilateral medial MB UKA were included and underwent computed tomography scans. The exclusion criteria included anterior cruciate ligament deficiency, postoperative knee pain, any postoperative complications, and musculoskeletal illnesses. A dual fluoroscopic imaging system was utilized to capture the single-leg lunge, and 2D-to-3D registration facilitated the visualization of knee motion. According to the knee motions, joint spaces on tibial and femoral surfaces in the lateral compartments of native, FB, and MB UKA knees were calculated and mapped. ResultsIn comparison to the native knees, FB UKA knees exhibited significant increases in medial, lateral, central, and posterior joint spaces in the lateral compartment (p < 0.05), while MB UKA knees showed significant increases only in central and posterior joint spaces (p < 0.05). Moreover, FB UKA demonstrated greater increases in medial, central, and posterior joint spaces compared to MB UKA. Tibial varus and valgus during lunges, as well as the Oxford Knee Score (OKS) and Hip-Knee-Ankle angle (HKA), correlated with joint spaces. ConclusionsDynamic joint space analysis provided a more comprehensive insight into contact dynamics. FB UKA led to an enlargement of joint spaces, whereas MB UKA resulted in joint spaces closer to native knees. These findings contribute to understanding potential postoperative complication in UKAs.

Slope Osteotomies in the Setting of Anterior Cruciate Ligament Deficiency.

➤ Posterior tibial slope (PTS) of ≥12° represents an important risk factor for both anterior cruciate ligament (ACL) injury and ACL reconstruction failure.➤ PTS measurements can significantly differ on the basis of the imaging modality and the measurement technique used. PTS should be measured on strictly lateral radiographs, with a recommended proximal tibial length of 15 cm in the image. The PTS measurement can be made by placing 2 circles to define the proximal tibial axis, 1 just below the tibial tubercle and another 10 cm below it. PTS measurements are underestimated when made on magnetic resonance imaging and computed tomography.➤ Slope-reducing osteotomies can be performed using a (1) supratuberosity, (2) tubercle-reflecting transtuberosity, or (3) infratuberosity method. The correction target remains a topic of debate. Although it is controversial, some authors recommend overcorrecting the tibial slope slightly to a range of 4° to 6°. For instance, if the initial slope is 12°, a correction of 6° to 8° should be performed, given the target tibial slope of 4° to 6°.➤ Clinical outcomes following slope-reducing osteotomies have been favorable. However, potential complications, limited data with regard to the impact of slope-reducing osteotomies on osteoarthritis, and uncertainty with regard to the effects on the patellofemoral joint are notable concerns.➤ Patients with complex deformities may need biplanar osteotomies to comprehensively address the condition.

The 45° and 60°of sagittal femoral tunnel placement in anterior cruciate ligament reconstruction provide similar knee stability.

The aim of the present study was to compare 45° and 60°of sagittal femoral tunnel angles in terms of anterior tibial translation (ATT), valgus angleand graft in situ force following anterior cruciate ligament reconstruction (ACLR). Ten porcine knees were subjected to the following loading conditions: (1) 89 N anterior tibial load at 35° (full extension), 60° and 90° of knee flexionand (2) 5 N m valgus tibial moment at 35° and 45° of knee flexion. ATTand graft in situ force of the intact anterior cruciate ligament (ACL) and ACLR were collected using a robotic universal force/moment sensor (UFS) testing system for (1) ACL intact, (2) ACL-deficient (ACLD) and (3) two different ACLR using different sagittal femoral tunnel angles (coronal 45°/sagittal 45° and coronal 45°/sagittal 60°). During the anterior tibial load, the femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° and 60° had significantly higher ATT than that of the ACL-intact knees at 60° of knee flexion (p < 0.05). The femoral tunnel angle of ACLR knees at coronal 45°/sagittal 60° had significantly lower graft in situ force than that of the ACL-intact knees at 60° and 90° of knee flexion (p < 0.05). During the valgus tibial moment, the femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° and 60° had significantly lower graft in situ force than that of the ACL-intact knees at all knee flexions (p < 0.05). The femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° provided similar ATT, valgus angleand graft in situ force to that of ACLR knees at coronal 45°/sagittal 60°. Therefore, both femoral tunnel angles could be used in ACLR, as the sagittal femoral tunnel angle does not appear to be relevant in post-operative knee stability. Not applicable.

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.

Poster 337: Graft Choice in Adolescents with Anterior Cruciate Ligament Injuries: Are All Grafts Equivalent?

Objectives: The choice of graft for anterior cruciate ligament (ACL) reconstruction (ACLR) plays a crucial role in the outcome of the procedure. Each graft choice has its advantages and disadvantages. Surgeons must consider various factors, including patient age, activity level, and individual anatomy, to make an informed decision on the most suitable graft choice for each patient. The objective of this study was to compare the incidence of retear in patients primary ACLR based upon autograft choice. Secondary objectives of this study were to analyze multivariate trends in retears to identify significant predictors followed by a stratified subanalysis. We hypothesized that hamstring tendon autografts would be associated with an increased number of ACLR graft ruptures. Methods: An institutional review board-approved retrospective cohort study was conducted. Surgical case logs were queried by current procedural terminology code 29888 to identify potential subjects between January 2012 and April 2020. Patients 21 years old and younger underwent primary ACLR within 6 months of injury. Subjects were excluded if they were older than 21 years at the time of injury, had congenital ACL insufficiency, underwent concurrent osteotomy, sustained a multiligamentous injury, or underwent a revision ACLR. Duplicate entries were excluded. Subjects were excluded if records did not have complete data for the purposes of the study. Knee imaging review determined skeletal maturity. Demographic data included age, sex, and body mass index. Each patient’s chart was reviewed to obtain laterality, mechanism of injury, skeletal maturity, and ACLR retear. Intraoperative data such as graft choice, graft size, and concomitant intra-articular pathology was collected. Data was analyzed for incidence of retear, and logistic regression identified predictors of retear. Results: A total of 977 patients were included in final analysis with 50 retears (5.11%). Comparison of graft choice showed significantly increased retears with hamstring tendon (HT) compared to quadriceps tendon (QT) (7.3% vs 3.3% (p = .050)) and patellar tendon (PT) (7.3% vs 2.8% (p = .008)) grafts. Multivariate analysis identified male sex (p &lt; .001), age at injury (p = .016), and smaller graft size (p = .024) as significant variables in cases of ACL rerupture. Analysis stratified by gender did not reveal any significance based upon graft choice, although, HT autograft approached significance (p = .065). During the subanalysis, skeletally immature individuals were significantly more likely to experience a retear (p = .007). Moreover, the incidence of retear based upon graft choice was significant within the skeletally mature cohort (p = .008), with a high incidence of HT retears (6.5%). HT grafts were the smallest grafts on average (8.227 mm). When comparing only QT and HT distributions, the graft size of QT was significantly larger (p &lt; .001); however, the distribution of retears was not significantly different. Conclusions: In patients &lt;22 years of age undergoing primary ACLR, HT autograft was associated with higher incidence of graft rupture compared to PT and QT autografts. There was no difference in retear proportion between QT and PT autografts. Multivariate regression identified male sex, older age at injury, and smaller graft size with increased risk of ACLR retear. There are many variables which portend ACLR graft failure of which sex plays a role; however, in this study, analysis via sex stratification was not significant, likely indicating some amount of variable interaction/confounding where sex as an isolated factor does not significantly influence retears rates. Given the number of variables that affect retears and the low incidence, it will likely take much larger types of meta-analysis studies to identify these traits by using multivariate models with interaction terms. Subanalysis by bone age showed that skeletal maturity does play a role in retears and should be taken into consideration by surgeons. Skeletally mature patients have a comparatively increased risk of graft rupture with HT autograft; moreover, skeletally immature patients incur graft failure not in terms of graft choice, but more so in fixation method as transphyseal and physeal-sparing methods are more technically demanding. Additionally, hamstring tendon grafts were significantly smaller than quadriceps tendon and PT autografts, which may contribute to the higher retear rates seen in this study. To our knowledge, this is the first study with large numbers showing inferiority of HT autograft as compared to both QT and PT autografts, which may be secondary to increased risk with male sex, skeletally mature patients, and smaller graft sizes. [Figure: see text][Figure: see text][Figure: see text][Figure: see text]

ATP-dependent citrate lyase Drives Left Ventricular Dysfunction by Metabolic Remodeling of the Heart.

Metabolic remodeling is a hallmark of the failing heart. Oncometabolic stress during cancer increases the activity and abundance of the ATP-dependent citrate lyase (ACL, Acly ), which promotes histone acetylation and cardiac adaptation. ACL is critical for the de novo synthesis of lipids, but how these metabolic alterations contribute to cardiac structural and functional changes remains unclear. We utilized human heart tissue samples from healthy donor hearts and patients with hypertrophic cardiomyopathy. Further, we used CRISPR/Cas9 gene editing to inactivate Acly in cardiomyocytes of MyH6-Cas9 mice. In vivo, positron emission tomography and ex vivo stable isotope tracer labeling were used to quantify metabolic flux changes in response to the loss of ACL. We conducted a multi-omics analysis using RNA-sequencing and mass spectrometry-based metabolomics and proteomics. Experimental data were integrated into computational modeling using the metabolic network CardioNet to identify significantly dysregulated metabolic processes at a systems level. Here, we show that in mice, ACL drives metabolic adaptation in the heart to sustain contractile function, histone acetylation, and lipid modulation. Notably, we show that loss of ACL increases glucose oxidation while maintaining fatty acid oxidation. Ex vivo isotope tracing experiments revealed a reduced efflux of glucose-derived citrate from the mitochondria into the cytosol, confirming that citrate is required for reductive metabolism in the heart. We demonstrate that YAP inactivation facilitates ACL deficiency. Computational flux analysis and integrative multi-omics analysis indicate that loss of ACL induces alternative isocitrate dehydrogenase 1 flux to compensate. This study mechanistically delineates how cardiac metabolism compensates for suppressed citrate metabolism in response to ACL loss and uncovers metabolic vulnerabilities in the heart.