Anterior Cruciate Ligament Reconstruction In Patients Research Articles

The impact of concomitant meniscal surgery on the clinical outcomes of anterior cruciate ligament reconstruction.

The aim of this study was to compare patient-reported outcomes (PROMs) following isolated anterior cruciate ligament reconstruction (ACLR), with those following ACLR and concomitant meniscal resection or repair. We reviewed prospectively collected data from the UK National Ligament Registry for patients who underwent primary ACLR between January 2013 and December 2022. Patients were categorized into five groups: isolated ACLR, ACLR with medial meniscus (MM) repair, ACLR with MM resection, ACLR with lateral meniscus (LM) repair, and ACLR with LM resection. Linear regression analysis, with isolated ACLR as the reference, was performed after adjusting for confounders. From 14,895 ACLR patients, 4,400 had two- or five-year Knee injury and Osteoarthritis Outcome Scores (KOOS) available. At two years postoperatively, the MM repair group demonstrated inferior scores in KOOS pain (β = -3.63, p < 0.001), symptoms (β = - 4.88, p < 0.001), ADL (β = - 2.43, p = 0.002), sport and recreation (β = - 5.23, p < 0.001), quality of life (QoL) (β = - 5.73, p < 0.001), and International Knee Documentation Committee (β = - 4.1, p < 0.001) compared with the isolated ACLR group. The LM repair group was associated with worse KOOS sports and recreation scores at two years (β = - 4.264, p < 0.001). At five years, PROMs were comparable between the groups. At five years, PROMs were comparable between the groups. Participants undergoing ACLR surgery within 12 weeks from index injury demonstrated superior PROMs at two and five years. Our study showed that MM repair, and to a lesser extent LM repairs in combination with ACLR, were associated with inferior patient-reported outcome measures (PROMs) compared to isolated ACLR at two years postoperatively, while meniscal resection groups exhibited comparable outcomes. However, by five years postoperation, no significant differences in PROMs were evident. Further longer-term, cross-sectional studies are warranted to investigate the outcomes of ACLR and concomitant meniscal surgery.

Complications of total knee arthroplasty in patients with prior anterior cruciate ligament reconstruction compared to a matched cohort

BackgroundCurrent literature reports a 500 % increase in reoperation in total knee arthroplasty (TKA) after anterior cruciate ligament reconstruction (ACLR). The purpose of this study is to determine the effect of ACLR on subsequent TKA. MethodsThis retrospective case control study included 30 patients that underwent TKA following an ACLR who were matched 3:1 to a control cohort at a single tertiary academic center between January 1, 2011 and January 1, 2021. The electronic medical records were queried for demographics, complications, history of ACLR, and range of motion (ROM) preoperatively and postoperatively at 3 months and 1 year. Student's t-tests and Fisher's exact tests were used for analysis (α = 0.05). ResultsThe mean ROM between the ACLR and control groups preoperatively, at 3 months and at 1 year postoperatively were 108.2° v 104.8° (p = 0.42), 114.0° v 111.8° (p = 0.51), and 115.3° v 115.8° (p = 0.88). At 1 year, 9 of 30 (30 %) ACLR patients decreased ROM versus 14 of 90 (15.6 %) control patients (mean loss of 21.4° v 11.9°, p = 0.076). No difference in complication rate was found (10 % v 11.1 %, p = 1). Complications in the ACLR group included open debridement and capsular release for stiffness after 2 failed manipulations under anesthesia (MUA), lysis of adhesions for patellar clunk, and revision surgery for flexion instability. No control patients required MUA. ConclusionThis study demonstrated that TKA following ACLR is without an increased risk of complications. However, ACLR patients should be followed closely since loss of ROM can be large.

The role of anterolateral complex surgery and slope-reducing osteotomies in revision ACL reconstructions: a narrative review.

Anterior cruciate ligament reconstruction (ACLR) failures occur for various reasons including residual laxity, untreated concomitant injuries, poor graft quality, and high tibial slope. Various additional procedures can help to decrease revision ACLR failures including anterolateral complex (ALC) procedures and slope-reducing osteotomies for patients with high tibial slopes. This narrative review aims to review the literature on the roles of ALC augmentation procedures and slope-reducing osteotomies in the setting of patients undergoing revision ACLRs. A narrative review of relevant literature was performed in July 2024. Studies about anterolateral complex reconstructions and slope-reducing osteotomies in revision ACLRs were included. The literature reported that lateral extra-articular tenodesis (LET) and anterolateral ligament reconstructions (ALLR) can be used in revision ACLR cases to significantly reduce clinical knee laxity and the risk of repeated graft failure. There is not currently a strong opinion on which ALC procedure is superior. There are reported slight differences in lateral knee pain and knee stiffness, but both similarly significantly improve clinical and functional outcomes. In revision ACLR cases that also have a high posterior tibial slope (PTS), a slope-reducing tibial osteotomy is warranted. An anterior closing wedge proximal tibial osteotomy (ACW-PTO) significantly reduces anterior tibial translation and graft failure. There is concern about the changes to patellar height, but the literature has found that such changes are either slight or absent by 6 months postoperatively. The risk of ACLR failure is increased by risk factors like high tibial slope, preoperative knee laxity, and prior ACLR rupture. Anterolateral complex procedures and slope-reducing osteotomies may be used to address these specific concerns and reduce the risk of graft rupture. For revision ACLR cases with lower PTS, augmentation with a LET or an ALLR to reduce the risk of graft failure and improve rotational stability may be warranted. In the setting of a revision ACLR in patients with a high PTS of ≥12°, a concomitant ACW-PTO and ALC procedure should be considered to decrease the risk of an ACLR graft failure.

Late (≥60 years old) and middle adulthood (40-59 years old) patients achieve similar improvement in patient-reported outcomes following ACL reconstruction.

This study aimed to compare the range of motion (ROM), surgical outcomes, and patient-reported outcome measures (PROMs) following anterior cruciate ligament (ACL) reconstruction outcomes in patients 60 years or older at the time of surgery to 40- to 59-year-old patients. In this retrospective cohort study from 2015 to 2022, a 3:1 propensity match was performed to match late adulthood patients (≥60 years old) undergoing ACL reconstruction with middle adulthood (40-59 years old) ACL reconstruction patients. Patients were matched based on sex, ACL graft utilized and concomitant procedures performed during ACL reconstruction. Statistical analysis compared demographics, preoperative injury management, surgical outcomes, PROMs, and minimal clinical important difference (MCID) and substantial clinical benefit (SCB) achievement rates for all ACL reconstruction patients included. Twenty late adulthood and 60 middle adulthood patients who underwent ACL reconstruction were included in the final cohort. Patients who were 60 years or older experienced no difference in reoperation rate (n.s.), incidence of retears (n.s.) or ROM (n.s.) at 1 year post-operatively. There were also no differences in International Knee Documentation Committee (ΔIKDC) (31.3 ± 19.1 vs. 34.2 ± 18.2, n.s.) or ΔPCS-12 (12.4 ± 9.8 vs. 12.9 ± 10.8, n.s.) scores at 1 year post-operatively. Furthermore, the younger and older patient cohorts demonstrated similar rates of achieving the MCID (80.0% vs. 83.3%, n.s.) and SCB (50.0% vs. 61.7%, n.s.) scores for IKDC. Patients 60 years or older and 40- to 59-year-old patients demonstrated similar outcomes after undergoing ACL reconstruction with allograft. This study concludes that ACL reconstruction in late adulthood can still be a successful treatment option and should allow surgeons to feel more comfortable when performing indicated surgical intervention for older patients who experience an ACL tear. Level III, Therapeutic III, retrospective cohort study.

Medial Meniscal Extrusion After Anterior Cruciate Ligament Reconstruction (ACLR) Associated With Meniscal Repair and Preoperative Extrusion.

The risk of post-traumatic osteoarthritis remains high even after anterior cruciate ligament reconstruction (ACLR). Medial meniscal extrusion (MME) is a valuable clinical sign as an early morphological change. This study aimed to analyze MME before and after ACLR and investigate the factors affecting postoperative MME. This study included patients who underwent anatomical double-bundle ACLR between January 2016 and July 2021. MME was measured using MRI preoperatively and one year postoperatively. The medial meniscus (MM) treatments were categorized into three groups: no MM injury and no repair (no injury/no repair (N/N)), MM injury but no repair (injury/no repair (I/N)), and MM injury and repair (injury/repair (I/R)). We investigated the factors influencing MME after ACLR using multiple linear regression analysis and compared MME before and after ACLR using paired t-tests. This study included 133 patients, of whom 90 (37 males and 53 females) were analyzed. The mean age of the patients at surgery was 27.5 years, and 41, 27, and 22 patients were assigned into N/N, I/N, and I/R groups, respectively. Preoperative MME (p<0.001) and I/R (p<0.001) had significant effects on postoperative MME in a regression analysis. Postoperative MME had greater effects than the preoperative MME in all cases (1.16 and 1.53 mm (p<0.01)) and in every MM treatment group (N/N: 1.02 and 1.32 mm (p<0.01), I/N: 1.16 and 1.44 mm (p<0.01), and I/R: 1.42 and 2.05 mm (p<0.001)). Larger preoperative MME and receiving MM repair were significantly associated with a larger MME after ACLR. Postoperative MME in ACLR patients was significantly greater than preoperative MME.

Histological Changes in the Blood Vessels of Ruptured Human Anterior Cruciate Ligaments.

Anterior cruciate ligament (ACL) rupture is a commonly encountered sports injury worldwide.ACL rupture is known to have poor healing capacity, hypothesized to be due to low vascularity. ACL reconstruction surgery with ligament removal and tendon graft became essential for the higher grades of ACL tears. However, ACL-reconstructed patients faced post-traumatic osteoarthritis 10-15 years after surgery. In the recent past, the tibial remnant of ACL was shown to have intrinsic healing potential. Blood vessel density and the location of blood vessels of ACL remnants have critical implications in the newly upcoming remnant-preservation ACL reconstruction surgeries that showed better healing response. This study was performed to characterize the histological features of ruptured ACL remnants in terms of blood vessels to assess the healing potential and their utility in novel surgical techniques. This was a descriptive cross-sectional study in which the tibial remnant of 24 ruptured ACL samples was evaluated for blood vessel density (per sq. mm), luminal area (sq. µm), and location of blood vessels using hematoxylin and eosin (H&E) staining with ImageJ software (U. S. National Institutes of Health, Bethesda, Maryland, USA). The blood vessel density and location of blood vessels were compared among various groups based on the duration of injury and number of injuries. Twenty-three male and one female adult patients with a mean duration of injury of 7.54 ± 5.63 months (range: 2-24 months) were included in the study. They were divided into three groups based on duration of injury: group I (2-5 months; n = 10), group II (6-8 months; n = 8), and group III (9-24 months; n = 6). The median blood vessel density (blood vessels per sq. mm) was 5.50 (3.30, 10.23) per sq. mm. There was no correlation of blood vessel density observed with duration of injury. All groups showed similar results statistically.More patients in earlier duration of injury showed very high range (10.1-40 per sq. mm) of blood vessels compared to the patients of later duration. Immature and intermediary blood vessels were identified denoting angiogenesis. Location of blood vessels varied in the groups based on duration of injury. There was no significant difference in blood vessel density and location of blood vessels between patients with single injury and those with multiple injuries. The present study demonstrates the presence of healing potential of ruptured anterior cruciate ligaments in terms of blood vessel density, luminal area, and location of blood vessels. Future studies looking into the functional outcome would enhance the understanding of utility of novel remnant-preservation surgeries in place of standard graft reconstruction surgeries.

Evolving cartilage strain with pain progression and gait: a longitudinal study post-ACL reconstruction at six and twelve months.

Anterior cruciate ligament (ACL) injuries are prevalent musculoskeletal conditions often resulting in long-term degenerative outcomes such as osteoarthritis (OA). Despite surgical advances in ACL reconstruction, a significant number of patients develop OA within ten years post-surgery, providing a patient population that may present early markers of cartilage degeneration detectable using noninvasive imaging. This study aims to investigate the temporal evolution of cartilage strain and relaxometry post-ACL reconstruction using displacement under applied loading MRI and quantitative MRI. Specifically, we examined the correlations between MRI metrics and pain, as well as knee loading patterns during gait, to identify early candidate markers of cartilage degeneration. Twenty-five participants (female/male = 15/10; average age = 25.6 yrs) undergoing ACL reconstruction were enrolled in a prospective longitudinal cohort study between 2022 and 2023. MRI scans were conducted at 6- and 12-months post-surgery, assessing T2, T2*, and T1ρ relaxometry values, and intratissue cartilage strain. Changes in pain were evaluated using standard outcome scores, and gait analysis assessed the knee adduction moment (KAM). Regressions were performed to evaluate relationships between MRI metrics in cartilage contact regions, patient-reported pain, and knee loading metrics. Increases in axial and transverse strains in the tibial cartilage were significantly correlated with increased pain, while decreases in shear strain were associated with increased pain. Changes in strain metrics were also significantly related to KAM at12 months. Changes in cartilage strain and relaxometry are related to heightened pain and altered knee loading patterns, indicating potential early markers of osteoarthritis progression. These findings underscore the importance of using advanced MRI for early monitoring in ACL-reconstructed patients to optimize treatment outcomes, while also highlighting KAM as a modifiable intervention through gait retraining that may positively impact the evolution of cartilage health and patient pain. Increased axial and transverse strains in the tibial cartilage from 6 to 12 months post-ACL reconstruction were significantly correlated with increased pain, suggesting evolving changes in cartilage biomechanical properties over time.Decreases in shear strain in inner femoral and central tibial cartilage regions were linked to increased pain, indicating alterations in joint loading patterns.Decreases in shear strain in the inner femoral cartilage were significantly associated with decreased 12-month knee adduction moment (KAM), a surrogate for medial cartilage knee loading during walking.

Assessing the Impact of Psychological Readiness on Performance and Symmetry in Functional Testing After ACL Reconstruction in Pediatric and Adolescent Patients.

Readiness for return to sports involves both physical and psychological aspects of recovery; however, the relationship between psychological and physical variables after anterior cruciate ligament (ACL) reconstruction (ACLR) is poorly understood. ACLR patients with a higher psychological readiness would demonstrate better functional testing results at 6 months. Cross-sectional study; Level of evidence, 3. Participants were evaluated at 6 months after ACLR with various patient-reported outcome metrics: Hospital for Special Surgery Pediatric Functional Activity Brief Scale, pediatric or adult International Knee Documentation Committee Questionnaire (IKDC), Patient-Reported Outcomes Measurement Information System (PROMIS) - Psychological Stress Experience and ACL - Return to Sport After Injury (ACL-RSI) scale. Functional testing included quadriceps, hamstrings, and gluteal strength testing; Y-balance test; single-leg single hop, crossover hop, and triple hop tests; and timed 6-m hop test. Pearson correlation coefficient and multivariable regression were used to determine associations between the limb symmetry index (LSI) on functional testing and patient-reported outcomes. Those with LSI deficits <20% (better performance) were compared with those with deficits >20% (worse performance). A total of 229 participants (89 male, 140 female) with a median age of 17 years (range, 10.3-30.6 years) were enrolled. IKDC had a moderate negative correlation with PROMIS - Psychological Stress Experience (r = -0.39; 95% CI = -0.49, -0.27; P < .001) and a moderate positive correlation with ACL-RSI (r = 0.55; 95% CI = 0.46, 0.64; P < .001). A total of 151 patients completed functional testing. ACL-RSI demonstrated a positive correlation with single-hop LSI (r = 0.21; 95% CI = 0.05, 0.35; P = .01) and timed 6-m hop (r = 0.28; 95% CI, 0.42; P = .001). When adjusting for sex, age, and graft type, patients who had <20% deficit on the single-hop test scored 16.6 points higher on ACL-RSI (P = .001), and those with <20% deficit on crossover hop testing scored a mean 13.9 points higher on ACL-RSI (P = .04). Higher psychological readiness for return to sport was associated with better performance and greater symmetry on hop testing 6 months after ACLR, suggesting a potential link between physical and psychological recovery.

Countermovement jump and vertical hop demonstrate braking/deceleration and performance alterations after ACL reconstruction with BMA, DBM, and suture tape augmentation

ObjectivesThis study evaluated countermovement jump and Single Leg Jump measures to identify landing measures that best distinguish a novel Anterior Cruciate Ligament reconstruction technique using bone marrow aspirate, demineralized bone matrix, and suture tape augmentation patients from controls. The secondary objective assessed performance differences between operated and non-operated limbs post-reconstruction. The hypothesis was that novel Anterior Cruciate Ligament reconstruction patients at return to sport would not differ from controls during landing and that the operated limb's performance would not differ from the unoperated limb. MethodsThe study included 31 patients with the novel reconstruction technique matched with controls in a 1:10 ratio based on age, sex, weight, and height. Both groups underwent screening and were compared during a Countermovement Jump. Using a Sparta Science Force Platform, each patient's unoperated and operated limbs were also compared for Single Leg Jump post-op (6.5 months). ResultsTest patients showed no difference in center of pressure during landing of both jumps compared to controls (P=0.27) and the uninvolved limb (P=0.26). Test patients exhibited increased braking impulse relative to the uninvolved limb during Single Leg Jump (P<0.001). Deceleration upon landing of Countermovement Jump was also increased compared to controls (P<0.001). Test patients demonstrated slower concentric time during a Countermovement Jump compared to controls (P=0.03) and significantly slower compared to the uninjured leg (P<0.001). Countermovement Jump height was decreased compared to controls (P<0.001). Single-leg jump height was decreased in the injured limb compared to the uninjured limb (P<0.001). ConclusionsTest patients did not show significant differences in landing motion compared to controls or the uninvolved leg. However, power and performance alterations were evident at Return to Sport after reconstruction. Although these results are quite promising, they may be too preliminary to draw definitive conclusions. Double and single-legged assessments should be considered in return-to-sport decision-making.

In the medium term, more than half of males report kinesiophobia after anterior cruciate ligament reconstruction

ObjectivesAnterior cruciate ligament rupture is a serious trauma with long-term consequences for the patient. Psychological and physiological factors may negatively affect patient recovery after anterior cruciate ligament reconstruction (ACLR), and development of kinesiophobia is possible. The aim of this study was to examine the presence of kinesiophobia and lower-leg muscle strength recovery in both sexes after ACLR. Methods140 ACLR patients agreed to participate in the study. Kinesiophobia was assessed using the Tampa Scale of Kinesiophobia (TSK). The Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS) and Tegner Activity Scale (TAS) were used for patient-related outcome measurements. In both legs quadriceps and hamstring muscle strength at 60°/s and 180°/s were measured with an isokinetic dynamometer. For dynamic balance and leg function, the Y-balance test and single-leg hop test were used. Results100 (71%) males and 40 (29%) females—mean age 32.5 (±8.3)—were examined 5.5 (±1.25) years after ACLR. 68/140 patients (48.6%) reported a TSK kinesiophobia score equal to or higher than 37 points: 54/100 (54%) males and 14/40 (35%) females (p ​= ​0.04). Patients with kinesiophobia had significantly lower KOOS values (p ​< ​0.001). In terms of the TAS no significant differences were found between those with or without kinesiophobia. Knee strength deficiency at 180°/sec and 60°/sec was significantly higher in the kinesiophobia group in knee extension in males (p ​= ​0.009) and knee flexion in females (p ​= ​0.001). Normalized body weight isokinetic average peak torque strength tests were significantly better in males compared to females in both groups (p ​< ​0.001). ConclusionBoth sexes reported high rates of kinesiophobia, but males are at higher risk of developing kinesiophobia than females in the medium term after ACLR. Furthermore, patients with kinesiophobia have significantly lower total KOOS scores, and females were significantly weaker than males in knee flexion and extension according to normalized body weight muscle strength tests. Also, a longer time from injury to surgery increases the risk of kinesiophobia in females. Level of evidenceLevel IV. Type of studyRetrospective case series study. Clinical trial registrationTrial registration in ClinicalTrials.gov. Identifier: NCT05762809.

Angle-Specific Analysis of Isokinetic Quadriceps and Hamstring Strength at 6 and 12 Months After Unilateral ACL Reconstruction.

Quadriceps and hamstring strength deficits are related to the increased risk of reinjury after anterior cruciate ligament reconstruction (ACLR). Knee angle-specific quadriceps and hamstring strength differences would be observed in patients with ACLR 6 and 12 months after surgery. Case-series. Level 4. A total of 23 postprimary unilateral ACLR patients followed-up at 6 and 12 months postoperatively and 25 controls were included. Isokinetic knee extension and flexion strength were evaluated at 60 deg/s from 20° to 90°. Statistical parametric mapping were performed to explore the angle-specific strength and the limb symmetry index (LSI). At 6 months postoperatively, the reconstructed leg demonstrated lower knee extension and flexion strength than the contralateral (20°-77°, 24°-90°) (P < 0.01) and control legs (22°-90°, 40°-82°) (P < 0.01). From 6 months to 12 months, knee extension (60°-90°) and flexion (20°-79°) strength improved in the reconstructed leg (P < 0.05), while LSI remained unchanged (P > 0.02). At 12 months, knee extension strength differences persisted in the reconstructed leg compared with the contralateral (20°-81°) and controls (25°-63°) (P < 0.01). ACLR patients had lower LSI of knee extension strength at 6 (20°-59°) and 12 (24°-57°) months postoperatively than the controls (P < 0.02). The reconstructed leg exhibited differences in knee extension strength compared with the contralateral and control legs. Although bilateral knee extension strength increased from 6 to 12 months postoperatively, LSI did not show improvement during this period. Quadriceps restoration was observed only in knee flexion angles greater than 60° compared with controls. Future studies should investigate whether knee extension strength, especially in lower flexion angles, can be enhanced through rehabilitation programs. Furthermore, assessing the impact of this improvement on long-term outcomes and reinjury risk in ACLR patients is warranted.

A Comparison of Machine Learning Algorithms (K-means) Using Data of Anterior Cruciate Ligament Reconstruction (ACLR) Patients

This research provides a comprehensive comparison of different machine learning (k-means clustering) algorithms as applied to datasets derived from Anterior Cruciate Ligament Reconstruction (ACLR) patients. The study aimed to find optimal clustering methodologies for ACLR patients’ data, focusing on knee measurements and their association with demographic factors such as age and physical activities. The researchers gathered data from 20 ACLR patients and 20 normal participants in Saudi Arabia’s eastern region. The researchers used machine learning algorithms (K-means clustering) for MATLAB programs.

Which patients need anterior cruciate ligament reconstruction after initial treatment with rehabilitation? A scoping review.

Some patients with anterior cruciate ligament (ACL) injury initially treated with rehabilitation need ACL reconstruction (ACLR); yet, it is unclear what characterizes these patients. This review aimed to describe predictors for ACLR in patients initially treated with rehabilitation. A systematic literature search was performed in the Cochrane, Embase, Medline, SportsDiscus and Web of Science databases from inception to 21 February 2023. Articles describing characteristics in adult patients with ACL injury undergoing ACLR after a minimum of 5 weeks rehabilitation were included. It was a priori chosen that characteristics described in at least three articles were considered more certain and could be defined as a predictor for ACLR, and those described in less than three articles were considered less certain and therefore defined as possible predictors. Articles were screened by two independent reviewers. The study was originally intended as a systematic review with meta-analysis, but in case of limited data, we would convert it to a scoping review, as was the case for this review. There were 22,836 studies identified, and 181 full texts were screened, of which 10 papers were finally included. Only lower age and higher preinjury activity level were identified as predictors for ACLR. Another 12 possible predictors were identified in single studies. Through an iterative process, potential predictors were categorized into four groups: patient demographics, knee function, patient-reported outcome measures and anatomical structures. Lower age and higher preinjury activity level were the only predictors for ACLR after initial treatment with rehabilitation. While younger and highly active patients show a higher need for ACLR, more studies focussing on predictors and reasons for delayed ACLR are warranted. Level II.

Sequential Comparison of Knee Muscle Strength after Anterior Cruciate Ligament Reconstruction between Hamstring Autograft and Tibialis Anterior Allograft: Propensity Score Matched Pair Analysis.

Among the graft options for anterior cruciate ligament reconstruction (ACLR), hamstring autografts are widely regarded as the preferred choice for primary ACLR among orthopedic surgeons worldwide. However, concerns persist regarding postoperative knee flexor weakness. We aimed to compare knee extensor and flexor strengths between hamstring autograft and tibialis anterior allograft groups in ACLR patients, who were propensity score-matched based on baseline characteristics. A retrospective analysis included 58 matched pairs who underwent isokinetic strength tests at 6 and 12 months post operation. Isokinetic muscle strength tests found no significant difference in knee extensor and flexor strength at 6 months post operation between the hamstring autograft and tibial anterior allograft groups. At 12 months, the hamstring autograft group exhibited significantly greater knee flexor deficit (total work and average power) compared to the allograft group, despite no differences in extensor strength or patient-reported outcomes. This study highlights the impact of hamstring autograft harvesting on muscle strength and recovery following ACLR in short-term period.

Early microRNA and metabolite changes after anterior cruciate ligament reconstruction surgery

ObjectivesAnterior cruciate ligament (ACL) reconstruction after injury does not prevent post-traumatic osteoarthritis (PTOA). Circulating microRNA (miRNA) and metabolite changes emerging shortly after ACL injury and reconstruction remain insufficiently defined, potentially harbouring early cues contributing to PTOA evolution. Moreover, their differential expression between females and males also may influence PTOA’s natural trajectory. This study aims to determine alterations in plasma miRNA and metabolite levels in the early stages following ACL reconstruction and between females and males. MethodsA cohort of 43 ACL reconstruction patients was examined. Plasma was obtained at baseline, 2-weeks, and 6-weeks post-surgery (129 biospecimens in total). High throughput miRNA sequencing and metabolomics were conducted. Differentially expressed miRNAs and metabolites were identified using negative binomial and linear regression models, respectively. Associations between miRNAs and metabolites were explored using time and sex as co-variants, (pre- versus 2- and 6-weeks post-surgery). Using computational biology, miRNA-metabolite-gene interaction and pathway analyses were performed. ResultsLevels of 46 miRNAs were increased at 2-weeks post-surgery compared to pre-surgery (baseline) using miRNA sequencing. Levels of 13 metabolites were significantly increased while levels of 6 metabolites were significantly decreased at 2-weeks compared to baseline using metabolomics. Hsa-miR-145-5p levels were increased in female subjects at both 2-weeks (log2-fold-change 0.71, 95%CI 0.22,1.20) and 6-weeks (log2-fold-change 0.75, 95%CI 0.07,1.43) post-surgery compared to males. In addition, hsa-miR-497-5p showed increased levels in females at 2-weeks (log2-fold-change 0.77, 95%CI 0.06,1.48) and hsa-miR-143-5p at 6-weeks (log2-fold-change 0.83, 95%CI 0.07,1.59). Five metabolites were decreased at 2-weeks post-surgery in females compared to males: L-leucine (-1.44, 95%CI -1.75,-1.13), g-guanidinobutyrate (-1.27, 95%CI 1.54,-0.99), creatinine (-1.17, 95%CI -1.44,-0.90), 2-methylbutyrylcarnitine (-1.76, 95%CI -2.17,-1.35), and leu-pro (-1.13, 95%CI -1.44,-0.83). MiRNA-metabolite-gene interaction analysis revealed key signalling pathways based on post-surgical time-point and in females versus males. ConclusionMiRNA and metabolite profiles were modified by time and by sex early after ACL reconstruction surgery, which could influence surgical response and ultimately risk of developing PTOA.

Limited correlation between physical performance and patient-reported outcomes at 1-year follow-up after anterior cruciate ligament reconstruction.

The majority of anterior cruciate ligament reconstruction (ACLr) patients wish to return to sport. Clinical evaluations after ACLr often do not include physical testing, making it difficult to determine the patient's readiness to return to sport. Thus, it would be helpful to identify easily assessable factors associated with physical function in ACLr patients that could inform planning of patients' return to sport. This study sought to evaluate the associations between physical test performance in ACLr patients and known ACL injury risk factors, knee laxity and patient-reported outcomes at 1-year follow-up. The cohort included isolated primary ACLr patients operated between 2009 and 2014. Patients were invited to a 1-year visit to clarify their readiness to return to sport. A test battery was performed, including clinical evaluation, patient-reported outcomes and three physical tests, from which the Leg Symmetry Index (LSI) was calculated. Multivariate regression analyses were performed for each of the physical tests, including known risk factors, clinical outcomes and patient-reported outcomes. Laxity <3 mm, pivot shift = 0, Knee Injury and Osteoarthritis Outcome Score (KOOS) sport >75, International Knee Documentation Committee (IKDC) >75.9, and Single Assessment Numeric Evaluation (SANE) >92.7 were applied as cut-off values for good versus poor status. A total of 480 ACLr patients were included in the study. Laxity <3 mm had a negative impact on the single-hop LSI, whereas a pivot shift = 0 or IKDC >75.9 had a positive impact on the single-hop LSI. Age <20, a pivot shift grade of 0 and KOOSsport >75 were positively associated with the triple-hop LSI. Finally, age <20 and IKDC >75.9 were positively associated with the leg extension strength LSI. Age, sagittal laxity, pivot shift and patient-reported outcomes were associated with physical test performance 1 year after ACLr. However, the associations were not completely uniform and strong, so information on age, sagittal laxity, pivot shift and patient-reported outcomes cannot replace a return-to-sport functional test battery in determining when it is safe to return to sport after ACLr. Level III.

Poster 321: Predictive Value of Functional Assessments During Perioperative Rehabilitation in Anterior Cruciate Ligament Reconstruction (ACLR)

Objectives: Perioperative rehabilitation is critical to restoring function and preventing reinjury in ACLR patients. Single-leg hop and isokinetic strength testing are commonly utilized by clinicians to assess patient progress. The impact of early stage progress on later stage outcomes is, however, not well understood. This study aimed to identify the effects of early postoperative isokinetic quadriceps strength and single-leg hop performance on functional recovery after primary ACLR, to determine the manner in which changes in these parameters during perioperative rehabilitation relate to fast and successful functional recovery. Methods: Patients having a primary ACLR were consented into a long-term study and were retrospectively reviewed with the following inclusion criteria: ACLR using a contralateral patellar tendon graft with normal extension ROM and stability at 2 months postoperative, per the International Knee Documentation Committee (IKDC) objective form. Patients were excluded with a preoperative modified Tegner level &lt;7. Predictor variables included 180°/second isokinetic quadriceps strength test (preoperative, 2 months, 4 months) and single leg hop for distance (preoperative and 4 months). Strength was assessed using limb symmetry index (LSI) with the ACLR knee strength being divided by the graft donor knee strength, percent of preoperative normal, and percent change over time at each interval, while hop testing was normalized to height. Outcome variables assessed were return to sport (RTS) time in months, return to preoperative modified Tegner level in the first 12 months after surgery (yes/no), and Cincinnati Knee Rating System (CKRS) at 12 months postoperative. Stepwise multiple regression analysis was used to predict RTS time, return to preoperative modified Tegner level, and CKRS based on demographics and objective measures. Results: A total of 1093 patients were eligible for analysis and 607 were used for the RTS model, 724 for the return to preinjury Tegner level model, and 705 for the CKRS model. Mean age for the cohort was 19.6 ± 5.5 years (range, 11.9-39.7) and 52.1% were male. In the model predicting RTS time, the following variables reduced RTS time: female sex, younger age, higher preoperative LSI, higher ACLR knee strength gains from preoperative to 2 month, and higher normalized single leg hop distance. In the model predicting a return to preoperative Tegner level, the following variables increased the likelihood: younger age, lower preoperative Tegner level, lower strength deficits with LSI at 2 months, and higher normalized single leg hop distance. In the model predicting CKRS scores, the following variables increased the score: younger age and higher normalized single leg hop distance. Model statistics can be seen in Table 1. Conclusions: The study found several early rehabilitation performance measures significantly influenced key outcomes. Perioperative rehabilitation should promote early relative gains in quadriceps strength for the ACLR knee, maintaining limb symmTaetry, and maximizing single leg hop distance to encourage faster RTS, higher subjective scores, and improve the likelihood of patients returning to preoperative activity levels. By quantifying the importance and predictiveness of these rehabilitation performance metrics, clinicians may improve their protocols to promote superior outcomes following ACLR.

Poster 354: Tibiofemoral Bone Shape Features Are Associated with Re-Tear after Anterior Cruciate Ligament Reconstruction

Introduction: Knee bony morphology is linked to anterior cruciate ligament (ACL) injury, ACL graft failure, and osteoarthritis (OA) risk, and employing tools such as statistical shape modeling could identify individuals prone to these joint conditions. Re-tear after ACL reconstruction remains a common and devastating complication, and therefore, recognizing patients at high risk of graft failure before primary ACL reconstruction is crucial for potential intervention to reduce failure rates. Magnetic resonance imaging (MRI) is most commonly obtained in the setting of possible ACL injury and before ACL reconstruction surgery, yet currently available MRI-based bone shape assessment methods require high-resolution sequences or manual segmentation, limiting feasibility of large-scale analysis. The development of automated tools for bone shape extraction from clinical MRI could allow for three-dimensional statistical shape modeling across large datasets. We established an automated pipeline for bone segmentation from proton density (PD)-weighted MRI scans, aiming to extract knee bony morphology from preoperative clinical MRIs in patients with ACL injuries. We hypothesized that our segmentation pipeline could uncover specific tibiofemoral joint bone shape features associated with ACL re-tear after reconstruction. Objective: To identify bone shape features prior to initial primary ACL reconstruction in patients with eventual ACL graft re-tear compared to those with a known, intact ACL graft. Methods: Patients who retrospectively experienced a subsequent re-tear after reconstruction within three years of initial injury were compared to those without a re-tear within three years (20 without subsequent re-tear, 22 with subsequent re-tear for distal femur; 22 without subsequent re-tear, 19 with subsequent re-tear for proximal tibia). The control group had MRI scans at 3 years after reconstruction that confirmed an intact ACL graft. An automatic femur and tibia segmentation framework was developed by training two deep convolutional neural networks using clinical, two-dimensional PD-weighted knee MRI sequences (3.5 mm slice thickness) from patients with ACL tears. Using the segmentation pipeline, bone was automatically segmented from preoperative clinical PD-weighted knee MRI sequence (3 mm slice thickness), three-dimensional triangulated meshes were generated, scaled to a reference, and aligned and matched to an atlas using Iterative Closest Point algorithm. Modes of shape variance were extracted from principal component analysis (PCA). The effect of each mode is modeled by three-dimensional surfaces for each specific shape feature. Modes were considered statistically significant if the mean principal component score between groups was p&lt;0.05 using Students T-test. Results: Statistical shape modeling of the femoral condyles using 15 PCA modes reveals significant differences (p &lt; 0.05) in Modes 1 and 4 at the initial injury in patients who subsequently experienced ACL re-tear after reconstruction compared to those without re-tear. Femur Mode 1 is characterized by a narrower intercondylar notch width, a wider medial condylar width, and an increased ratio of femoral condylar offset in patients with ACL re-tear. Femur Mode 4 illustrates a more prominent trochlear sulcus and increased surface area along the lateral femoral condyle relative to the medial condyle in patients with ACL re-tear. The initial 15 PCA modes of the distal femur collectively account for 75.04% of the normalized accumulated total variance. Statistical shape modeling of the tibial plateau with 15 PCA modes reveals that Mode 7 is significantly different (p &lt; 0.05) at the initial injury in patients who experienced subsequent ACL re-tear after reconstruction compared to those without re-tear. Tibia Mode 7 indicates diminished ACL facet prominence, a squared lateral tibial plateau, and a broader, flatter tibial spine in patients with subsequent ACL re-tear. The first 15 PCA modes of the proximal tibia collectively explain 73.60% of the normalized accumulated total variance. Conclusions: Using an automatic bone segmentation pipeline on preoperative clinical MRIs, we identify specific shape features in the tibiofemoral joint associated with ACL re-tear after reconstruction. Patients with subsequent ACL re-tear exhibit a variety of distinct three-dimensional morphology differences, including reduced intercondylar notch width, wider medial condylar width, increased lateral tibial plateau convexity, and broader, lateralized tibial spine, uncovered using statistical shape modeling. Statistical shape modeling identifies three-dimensional morphology patterns, thus capturing differences otherwise unaccounted for by traditional two-dimensional measurements. This approach offers predictive potential for patients at risk of ACL re-tear, improving treatment decisions for those with high-risk morphologic features.

Conditioning of Motor Evoked Responses After Anterior Cruciate Ligament Reconstruction: Effects of Stimulus Intensity.

Operant conditioning of motor evoked torque (MEPTORQUE) can directly target the corticospinal pathway in patients with anterior cruciate ligament (ACL) reconstruction. However, it remains unclear whether operant conditioning can elicit short-term improvements in corticospinal excitability and whether these improvements are influenced by stimulus intensity. Quadriceps MEPTORQUE responses can be upconditioned in a single session and will elicit short-term adaptations in corticospinal excitability, with higher stimulus intensities eliciting greater effects. Randomized controlled laboratory study. Level 2. Thirty-six participants were assessed during a single session of an operant conditioning protocol. Participants were randomized into 1 of 3 groups for stimulus intensity used during operant conditioning based on the participant's active motor threshold (AMT: 100%, 120%, and 140%). Quadriceps MEPTORQUE amplitude was evaluated during a block of control transcranial magnetic stimulation trials (CTRL) to establish baseline corticospinal excitability, and 3 blocks of conditioning trials (COND) during which participants trained to upcondition their MEPTORQUE. MEPTORQUE recruitment curves were collected to evaluate the effect of operant conditioning on acute corticospinal adaptations. Participants with ACL reconstruction could upcondition their MEPTORQUE in a single session (P < 0.01; CTRL, 17.27 ± 1.28; COND, 21.35 ± 1.28 [mean ± standard error [SE] in N·m]), but this ability was not influenced by the stimulus intensity used during training (P = 0.84). Furthermore, significant improvements in corticospinal excitability were observed (P = 0.05; PRE, 687.91 ± 50.15; POST, 761.08 ± 50.15 [mean ± SE in N·m %AMT]), but stimulus intensity did not influence corticospinal adaptations (P = 0.67). Operant conditioning can elicit short-term neural adaptations in ACL-reconstructed patients. Future operant conditioning paradigms may effectively use any of the 3 stimulus intensities studied herein. Operant conditioning may be a feasible approach to improve corticospinal excitability after ACL reconstruction.

Item-reduced Forgotten Joint Score provides adequate psychometric properties in ACLR patients.

The purpose of this study was to evaluate content validity, test-retest reliability, internal consistency, construct validity, responsiveness and floor/ceiling effects of Forgotten Joint Score (FJS) for assessing functions in activities of daily living (ADL) following anterior cruciate ligament reconstruction (ACLR) and perform an item reduction of FJS. Swedish-speaking ACLR patients in one surgical clinic were eligible. Content validity was evaluated through patient responses and patient and expert clinician relevance ratings, omitting items with low relevance. Principal component factor analysis, Cronbach's ⍺, paired t test, correlations between FJS and Knee Injury and Osteoarthritis Outcome Score (KOOS), Cohen's d effect sizes (ESs) andstandardized response mean (SRM) were used to evaluate internal consistency, test-retest reliability, construct validity andresponsiveness. Floor/ceiling effects were calculated. FJS was expected to reveal one dominant factor, a Cronbach's ⍺ between 0.70 and 0.95, correlations >0.50 to all KOOS subscores, highest for ADL, moderate ES and SRM, floor/ceiling effects <15%. One hundred and seventy-six participants (103 for assessing internal consistency, construct validity, responsivenessand floor/ceiling effects; 73 for assessing test-retest reliabilityand content validity) were included. Item reduction yielded a nine-item FJS (FJS-9). FJS-12 and FJS-9 demonstrated sufficient content validity (95% confidence interval [CI], 2.5-3.1, respectively, 2.9-3.3). FJS-9 was found unidimensional, and FJS-12 was multidimensional. Cronbach's ⍺ was 0.94 for FJS, and the intraclass correlation coefficient > 0.90. FJS showed significant correlations >0.65 to all KOOS subscales, moderate ES and SRM > 0.50. No floor/ceiling effects were found. FJS-9 demonstrated adequate validity for the evaluation of joint awareness in ACLR patients and can be a valuable tool to assess ADL and joint awareness. Level III.