Long-term effects of non-weight bearing and immobilization after anterior cruciate ligament reconstruction on joint contracture formation in rats.

PURPOSE: Non-weight bearing improves and immobilization worsens contracture induced by anterior cruciate ligament reconstruction (ACLR), but effect persistence after reloading and remobilization remains unclear, and the combined effects of these factors on ACLR-induced contracture are unknown. We aimed to determine 1) whether the effects of short-term (2-week) non-weight bearing or immobilization after ACLR on contracture would be sustained by reloading or remobilization during a 10-week observation period, and 2) how the combination of both interventions compared to the outcome of either alone. METHODS: We divided 88 ACL-reconstructed male rats into four groups: non-intervention, non-weight bearing, joint immobilization, and both interventions. Interventions were performed for 2 weeks, followed by rearing without intervention. Twelve untreated rats were used as controls. At 2, 4, and 12 weeks post-surgery, we assessed range of motion (ROM) and histological changes. RESULTS: ACLR resulted in persistent loss of ROM, accompanied by synovial shortening, capsule thickening, and osteophyte formation. Two weeks of non-weight bearing increased ROM and reduced osteophyte size, but the beneficial effects disappeared within 10 weeks after reloading. Two-week immobilization decreased ROM and facilitated synovial shortening. After remobilization, ROM partially recovered but remained below non-intervention levels at 12 weeks. When both interventions were combined, ROM was similar to immobilization alone. CONCLUSIONS: The beneficial effects of 2-week non-weight bearing on contracture diminished within 10 weeks after reloading. The adverse effects of 2-week immobilization on contracture persisted after 10 weeks of remobilization. The effects of the combined use of both interventions on contracture were primarily determined by immobilization.

Comparison of knee flexor strength recovery between semitendinosus alone versus semitendinosus with gracilis autograft for ACL reconstruction: a systematic review and meta-analysis.

BACKGROUND: Whether there is a difference in harvesting the semitendinosus tendon alone (S) or in combination with the gracilis tendon (SG) for the recovery of knee flexor strength after anterior cruciate ligament (ACL) reconstruction remains inconclusive. Therefore, this study aimed to assess the recovery of knee flexor strength based on the autograft composition, S or SG autograft at 6, 12, and ≥ 24 months after ACL reconstruction. METHODS: A systematic review and meta-analysis was conducted following the PRISMA guidelines. A comprehensive search was performed encompassing the Cochrane Library, Embase, Medline, PEDRo and AMED databases from inception to January 2023. Inclusion criteria were human clinical trials published in English, comprised of randomized controlled trials (RCTs), longitudinal cohort-, cross-sectional and case-control studies that compared knee flexor strength recovery between S and SG autografts in patients undergoing primary ACL reconstruction. Isokinetic peak torques were summarized for angular velocities of 60°/s, 180°/s, and across all angular velocities, assessed at 6, 12, and ≥ 24 months after ACL reconstruction. A random-effects model was used with standardized mean differences and 95% confidence intervals. Risk of bias was assessed with the RoBANS for non-randomized studies and the Cochrane RoB 2 tool for RCTs. Certainty of evidence was appraised using the GRADE working group methodology. RESULTS: Among the 1,227 patients from the 15 included studies, 604 patients received treatment with S autograft (49%), and 623 received SG autograft (51%). Patients treated with S autograft displayed lesser strength deficits at 6 months across all angular velocities d = -0.25, (95% CI -0.40; -0.10, p = 0.001). Beyond 6 months after ACL reconstruction, no significant difference was observed between autograft compositions. CONCLUSION: The harvest of S autograft for ACL reconstruction yields superior knee flexor strength recovery compared to SG autograft 6 months after ACL reconstruction, irrespective of angular velocity at isokinetic testing. However, the clinical significance of the observed difference in knee flexor strength between autograft compositions at 6 months is questionable, given the very low certainty of evidence and small effect size. There was no significant difference in knee flexor strength recovery between autograft compositions beyond 6 months after ACL reconstruction. TRIAL REGISTRATION: CRD42022286773.

Anterior Cruciate Ligament (ACL) Reconstruction Augmentation With Bone Marrow Aspirate, Demineralized Bone Matrix, and Suture Tape Demonstrates No Difference In Outcomes, But Faster Functional Recovery, Versus Non-augmented ACL Reconstruction.

PURPOSE: To compare outcomes after anterior cruciate ligament reconstruction (ACLR) with bone marrow aspirate concentrate (BMAC), demineralized bone matrix (DBM), and suture tape augmentation (STA) vs. ACLR without biologic augmentation or STA. METHODS: A prospective randomized controlled trial at a single institution was performed to compare ACLR with BMAC, DBM, and STA (Group A) vs. ACLR without biologic or STA (Group NA). One hundred patients were required. Skeletally mature patients <25 years old received quadriceps tendon autografts, while patients ≥25 years old received allograft ACLR with an all-inside technique. Concomitant meniscal pathologies were included. Primary outcomes compared were range-of-motion (ROM), limb symmetry, and patient-reported outcomes (PROs). Secondary outcomes included radiographic outcomes and surgical complications. Univariate and mixed-model regression analysis were used to compare outcomes. RESULTS: Fifty-nine patients were included (Group A: 29 patients, 11 females, 38%; Group NA: 30 patients, 15 females, 50%). Early range-of-motion at 6 weeks (125° vs 109° flexion, p<0.0001) and limb symmetry testing at 12 weeks (80.6 % vs. 36.7% [Delta 43.9%], p<0.001) were significantly improved in Group A. At two years, International Knee Documentation (IKDC) scores were similar (91.1 ± 12.7 vs. 85.3 ± 10.8, p=0.109). Knee Injury and Osteoarthritis and Outcome Score (KOOS) Quality of Life (QOL) scores were significantly enhanced in Group A (85.2 ± 20.9 vs. 72.1 ± 20.4, p=0.042). Twenty-two patients (12 Group A, 10 Group NA) underwent CT scans at 6-months to compare bone tunnel healing. Overall, the mean increase in bone tunnel diameter was significantly smaller in Group A vs. NA. No difference in graft re-ruptures or re-operations was observed. Seven of 59 patients (11.9%) underwent re-operation for stiffness (A: 3 (10%) vs. NA: 4 (13%), p=1.0). CONCLUSION: There were no differences in IKDC scores between groups at 2-year follow-up. Functional outcomes including early range-of-motion and limb symmetry were significantly improved in patients who received ACLR with BMAC, DBM, and STA. ACLRACLR.ACLR.

Presoaking hamstring autograft with vancomycin does not jeopardize its biomechanical properties, including graft elongation, after cyclic loading.

PURPOSE: Presoaking the graft with vancomycin before implantation has been shown to reduce the risk of postoperative infection after anterior cruciate ligament reconstruction (ACLR). However, the effects of presoaking on the graft biomechanical properties remain unclear. This study aimed to determine whether presoaking the graft with vancomycin affects the graft biomechanical properties and length after cyclic loading. METHODS: Ten paired (20 specimens) gracilis and semitendinous tendons were harvested from fresh-frozen human cadaveric specimens. Two tendons were folded in half to make four strands, and the grafts were randomized into the vancomycin and control groups. The graft was exposed to the antibiotic solution for 15 min (5 mg/mL) and prepared by mixing 1 g of vancomycin with 200 mL of normal saline (NaCl 0.9%). The control group was soaked in normal saline for 15 min. The prepared grafts were attached to the actuator of a dynamic tensile-testing machine. All grafts were tested with 3000 cycles of cyclic loading followed by a pull-to-failure. The cyclic loading protocol consisted of position and load control blocks to simulate the graft in vivo in the postoperative phase after ACLR. RESULTS: Presoaking in vancomycin did not jeopardize the biomechanical properties of the graft. In addition, presoaking with vancomycin did not elongate the grafts. No significant differences were found in the mean Young's modulus and the mean total elongation of the graft of the specimen between the vancomycin group and the control group. CONCLUSION: Presoaking the graft with vancomycin jeopardized neither its biomechanical properties nor elongation even after cyclic loading in this in vitro study. It is suggested that vancomycin presoaking could be considered a safe and effective preventive measure for postoperative infections after ACLR. LEVEL OF EVIDENCE: Not applicable.

Revision ACL reconstruction, but not bilateral ACL reconstruction, is associated with clinically relevant inferior subjective knee function compared with primary ACL reconstruction: A comparative analysis of 6831 patients.

PURPOSE: To evaluate and compare the subjective knee function in patients undergoing revision and bilateral anterior cruciate ligament (ACL) reconstruction (ACLR) with those undergoing primary ACLR in a large cohort. METHODS: Patients without concomitant ligament injuries who underwent primary, revision or bilateral ACLR at the Capio Artro Clinic, Stockholm, Sweden, between 2005 and 2018 were identified. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1, 2 and 5 years postoperatively from the Swedish National Knee Ligament Registry. Patients who underwent revision and bilateral ACLR were compared with those who underwent primary ACLR (control group) using Student's t test. RESULTS: A total of 6831 patients (6102 with primary ACLRs, 343 with revision ACLRs and 386 with bilateral ACLRs) were included. Preoperatively, there were significant but nonclinically relevant differences in favour of the revision ACLR group for KOOS Symptoms, Pain, Activities of Daily Living (ADL) and Sport/Rec subscale scores compared with the primary ACLR group. Postoperatively, except for the 1-year Symptoms and ADL subscales, the revision ACLR group reported significantly lower scores on all KOOS subscales than the primary ACLR group, with clinically relevant differences (>8-10 points) for the 1-, 2- and 5-year Sport/Rec and Quality of Life (QOL) subscales. The bilateral ACLR group reported significantly, but not clinically relevant, inferior scores on the 1-year Symptoms and QOL subscales and the 5-year Sport/Rec and QOL subscales compared with the primary ACLR group. CONCLUSIONS: Revision ACLR, but not bilateral ACLR, was associated with clinically relevant inferior subjective knee function compared with primary ACLR. It is important to counsel patients regarding their future subjective knee function after repeated ACLR. Compared to primary ACLR, inferior subjective results should be expected after revision ACLR, but not after bilateral ACLR. LEVEL OF EVIDENCE: Level III.

A new neural network model that detects graft ruptures and contralateral anterior cruciate ligament injuries.

PURPOSE: The purpose of this study was to develop a neural network model for predicting second anterior cruciate ligament (ACL) injury risk following ACL reconstruction using patient features from medical records. METHODS: Of 486 consecutive patients who underwent primary unilateral ACL reconstruction, 386 patients (198 women, 188 men) with a mean age of 25.1 ± 11.6 years were included in this study. Fifty-eight features, including demographic data, surgical, preoperative and postoperative data, were retrospectively collected from medical records, and features with an incidence of less than 5% were excluded. Finally, 14 features were used for the analysis. The multilayer perceptron was composed of four hidden layers with a rectified linear unit as activation and was trained to maximise the area under the receiver-operating characteristic curve (auROC). Subsequently, validation was carried out through a rigorous threefold cross-validation process. To ascertain the most efficacious combination of features with the highest auROC, a single feature with the least impact on auROC maximisation was systematically eliminated from the comprehensive variable set, ultimately resulting in the retention of a mere two variables. RESULTS: The median follow-up period was 50.5 (24-142) months. Fifty-seven knees had a second ACL injury, with a graft rupture rate of 7.7% and a contralateral injury rate of 6.9%. The maximum auROC for predicting graft rupture was 0.81 with two features: young age and hamstring graft. Meanwhile, the maximum auROC for predicting contralateral ACL injury was 0.74 with seven features, including young age, presence of medial meniscus tear, small body mass index, hamstring graft, female sex and medial meniscus repair or treatment. CONCLUSION: A neural network model with patient features from medical records detected graft ruptures and contralateral ACL injuries with acceptable accuracy. This model can serve as a new, useful tool in clinical practice to inform decisions about ACL reconstruction and retuning to sports postoperatively. LEVEL OF EVIDENCE: Level IV.

Risk factors for reoperation for arthrofibrosis following primary anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study is to identify the rate and risk factors for a reoperation for arthrofibrosis following primary anterior cruciate ligament (ACL) reconstruction. METHODS: Prospective data recorded in the New Zealand ACL Registry were cross-referenced with data from the Accident Compensation Corporation (ACC). Primary ACL reconstructions performed between April 2014 and May 2021 were analysed. The ACC database was used to identify patients who underwent a reoperation for a diagnosis of arthrofibrosis. Multivariable survival analysis was performed to compute adjusted hazard ratios (aHR) and 95% confidence intervals. RESULTS: A total of 12,296 primary ACL reconstructions were analysed, of which 230 underwent a reoperation for arthrofibrosis (1.9%) at a mean follow-up of 3.6 years. A higher risk of arthrofibrosis was observed in females (aHR = 1.76, p = 0.001), patients with a history of previous knee surgery (aHR = 1.82, p = 0.04) and when a transtibial drilling technique was used (aHR = 1.53, p = 0.03). ACL reconstruction >6 months after injury had the lowest rate of arthrofibrosis (1.3%, aHR = 0.45, p = 0.01). There was no difference in risk between early surgery within 6 weeks versus delayed surgery between 6 weeks and 6 months after injury (2.9% versus 2.1%, aHR = 0.78, not significant). CONCLUSION: Female sex, previous knee surgery and a transtibial drilling technique increased the risk of reoperation for arthrofibrosis. Early surgery within 6 weeks of injury was not associated with an increased risk when compared with surgery between 6 weeks and 6 months after injury. LEVEL OF EVIDENCE: Level III.

Patellar bone defect grafting does not reduce anterior knee pain after bone-patellar tendon-bone anterior cruciate ligament reconstruction.

PURPOSE: Donor site morbidity is the main drawback to using bone-patellar tendon-bone (BPTB) as a graft in anterior cruciate ligament (ACL) reconstruction. The objective of the study was to determine whether refilling the patellar bone defect after BPTB harvesting with autograft bone decreased kneeling pain to a greater degree when compared with a group in which bone defect is left unaddressed. METHODS: This is a randomised single-blinded controlled study. Forty patients were randomised into two groups; group 1: Patellar bone defect filled with autologous bone; group 2: Bone defect left undressed. Pain was measured by means of pressure algometry (PA). Functional outcomes were measured with the Kujala and Victorian Institute of Sport Assessment-Patella (VISA-P) score. Magnetic resonance imaging (MRI) was done to measure bone buildup between groups at the 1-year follow-up. RESULTS: No differences were observed in the different algometry measurements and the scores were assessed at 3, 6 and 12 months postoperatively. The ratio of void filled remained consistently higher (p = 0.003) in group 1 when compared to group 2. CONCLUSIONS: Although refilling the lower pole of the patella with autologous bone from the harvested BPTB autograft loads the bone defect, it does not reduce pain at the donor site 1 year after surgery. LEVEL OF EVIDENCE: Therapeutic study level 1.

Validating the capture rate of revisions by the New Zealand ACL Registry: An analysis of all-cause reoperation following primary ACL reconstruction.

PURPOSE: To validate the New Zealand Anterior Cruciate Ligament (ACL) Registry's capture rate of revisions by cross-referencing Registry data with reoperations data recorded by the Accident Compensation Corporation (ACC) and identify risk factors for all-cause reoperation. METHODS: Primary ACL reconstructions performed between April 2014 and September 2019 were individually matched on a record-by-record basis between the two databases. The ACC database was used to identify patients who underwent a reoperation with manual review of operation notes to identify whether a revision or other procedure was performed. This was combined with the number of revisions separately recorded in the New Zealand ACL Registry, which was used as the denominator value to calculate the Registry's capture rate of revisions. Patient and surgical data recorded in the Registry were analysed to identify independent predictors for all-cause reoperation. RESULTS: A total of 8046 primary ACL reconstructions were matched between the New Zealand ACL Registry and the ACC databases. The reoperation rate was 8.9% (n = 715) at a mean follow-up of 2.5 years. Meniscal-related procedures were the most common reoperation (n = 299, 3.7%), followed by revision ACL reconstruction (n = 219, 2.7%), arthrofibrosis (n = 185, 2.3%), cartilage (n = 56, 0.7%) and implants (n = 32, 0.4%). The New Zealand ACL Registry captured 96% of revisions. Younger age (hazard ratio [HR] > 1.4, p < 0.001), earlier surgery (HR > 1.3, p = 0.05), concurrent meniscal repair (medial meniscus HR = 1.9, p < 0.001 and lateral meniscus HR = 1.3, p = 0.022) and hamstring tendon autografts (HR = 1.4, p = 0.001) were associated with a higher risk of reoperation. CONCLUSION: The New Zealand ACL Registry captured 96% of revisions. Risk factors for all-cause reoperation included younger age, earlier surgery, meniscal repair and hamstring tendon autografts. LEVEL OF EVIDENCE: Level III.

Identifying iliotibial band graft length and incision site may minimise the potential risk of harming adjacent structures: A novel approach for surgeon guidance.

PURPOSE: The Iliotibial band (ITB) is a fibrous thickening of the fascia lata originating at the iliac crest and inserting at Gerdy's tubercle on the lateral tibia. The ITB significantly contributes to lateral knee stabilisation. Due to its size, tensile strength and easy access, it is widely used in orthopaedic surgery as an autograft during reconstruction procedures. Although ITB harvesting may result in complications, such as reduced knee extension or hip flexion, no safety margins or guidelines have been proposed for the procedure. Our aim was to determine the maximal safe length of an ITB graft, that is, that does not harm the lateral collateral ligament (LCL), tensor fasciae latae (TFL), gluteus maximus (GM) or adjacent structures, and reduce the complication rate. METHODS: The study included 50 lower limbs of 25 human cadavers, previously fixed in 10% formalin solution. The inclusion criterion was the lack of visible signs of surgical interventions in the study region. Forty lower limbs were included in the study: 16 female (mean age 83.1 ± 3.4 years) and 24 male (mean age 84.2 ± 6.8 years). Dissection was performed with a previously established protocol. Morphometric measurements were then obtained twice by two researchers. RESULTS: The mean femur length was 404.8 mm [female (F) = 397.3 mm, male (M) = 409.9 mm, standard deviation (SD): F = 23.8 mm, M = 24.1 mm]. The mean ITB length was 318.9 mm (F = 309.4 mm, M = 325.2 mm, SD: F = 25.7 mm, M = 33.7 mm). Longer femurs were associated with longer ITB (p < 0.05). The mean distance from the insertion of the GM to the myofascial junction of TFL and ITB was 34.6 mm (F = 34.5 mm, M = 34.6 mm, SD: F = 3.2 mm, M = 3.3 mm). The longer femurs or ITBs demonstrated a greater distance from GM insertion to the myofascial junction of the TFL and ITB (p < 0.05). CONCLUSION: ITB grafts longer than 21 cm may contribute to the greater risk of TFL rupture. Based on simple measurements of the femur length, the surgeon may assess approximate ITB length, and thus assess the length of the maximal graft length. Moreover, to avoid harming the LCL, the incision should be performed 5 cm proximal to the articular surface of the lateral femoral condyle or 13 mm proximal to the lateral femoral epicondyle. Such preparation and preoperative planning may greatly reduce the risk of complications during ITB harvesting, while performing, for instance, the over-the-top technique for anterior cruciate ligament reconstruction in skeletally immature patients. LEVEL OF THE STUDY: Basic I.

Lateral extra-articular tenodesis does not enhance ACL graft healing, however, does reduce graft tunnel widening.

PURPOSE: The study hypothesized that the addition of lateral extra-articular tenodesis (LEAT) in anterior cruciate ligament reconstruction (ACLR) had a significant effect on ACL graft healing. METHODS: A total of 80 patients were divided into two cohorts matched for gender, age, body mass index, time from surgery to post-operative MRI and graft diameter. Forty patients underwent ACL reconstruction alone, while 40 underwent ACLR in addition to LEAT. Patients underwent a magnetic resonance imaging scan at 12 months post-surgery; tunnel apertures were measured using multiplanar reformation, graft healing was assessed using signal-to-noise quotient (SNQ) in three regions of interest and finally graft maturity and integration were classified using the Howell and Ge scale, respectively. In addition, clinical evaluation and patient-reported outcome measures were collected. RESULTS: The mean femoral tunnel widening at 12 months post-surgery was 39.8 ± 14.0% in the ACLR + LEAT group and 55.2 ± 12.7% in the ACLR alone group (p < 0.05). The mean tibial tunnel widening was 29.3 ± 12.7% in the ACLR + LEAT group and 44.4 ± 12.1% in the ACLR group (p < 0.05). The mean adjusted graft SNQ was 9.0 ± 14.9 in the ACLR + LEAT group and 9.5 ± 11.4 in the ACLR group (n.s.). CONCLUSION: At 1 year post-operatively, we noted significantly less femoral and tibial tunnel widening in the ACLR + LEAT group. LEAT did not result in a statistically significant effect on graft healing. LEVEL OF EVIDENCE: Level III.

Management after acute injury of the anterior cruciate ligament (ACL). Part 3: Recommendation on surgical treatment.

PURPOSE: The aim of this consensus project was to give recommendations regarding surgical treatment of the anterior cruciate ligament (ACL) injured patient. METHODS: For this consensus process, an expert, steering and rating group was formed. In an initial online meeting, the steering group, together with the expert group, formed various key topic complexes for which multiple questions were formulated. For each key topic, a structured literature search was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Sufficient consensus was defined as 80% agreement. RESULTS: During this consensus process, 30 topics regarding the surgical management and technique of ACL reconstruction were identified. The literature search for each key question resulted in 30 final statements. Of these 30 final statements, all achieved consensus. CONCLUSIONS: This consensus process has shown that surgical treatment of ACL injury is a complex process. Various surgical factors influence patient outcomes. The proposed treatment algorithm can be used as a decision aid for the surgeon. LEVEL OF EVIDENCE: Level V.

Ten-year results from the UK National Ligament Registry: Patient characteristics and factors predicting nonresponders for completion of outcome scores.

PURPOSE: The aim of this study was to report the demographic and mechanism of injury data in the UK National Ligament Registry (NLR) at 10 years and determine factors leading to poor compliance with completion of Patient-Reported Outcome Scores (PROMs). METHODS: A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary anterior cruciate ligament reconstruction (ACLR) were included. Patient demographics, mechanism of injury and patient compliance with completing PROMs were analysed. Patient characteristics were further analysed in relation to compliance with completing the different PROMs at the predefined time points. Patients were identified as nonresponders if they had not completed either 1- or 2-year postoperative Knee injury and Osteoarthritis Outcome Score (KOOS). RESULTS: A total of 17,492 patients were included in this study. The average age for patients undergoing ACLR between 2013 and 2022 was 29.4 (SD, 10.3). Seventy percent were men and 30% women. Football was the most common activity associated with an ACL injury. Patient compliance with recording PROMs was 55% preoperatively and 37%, 32% and 24% at 1-, 2- and 5-year postoperative follow-up, respectively. Nonresponders represented 54% of eligible patients. Multivariate analyses showed that sex, age, smoking, time interval between injury and surgery and low socioeconomic status were associated with low compliance with postoperative PROM completion (p < 0.001). CONCLUSION: This study reports the demographic characteristics for patients on the NLR since 2013. Male sex, young age, increased waiting time between injury and surgery, smoking and lower socioeconomic class were predictors of low compliance with completion of postoperative PROMs on the UK NLR. Understanding the factors that affect patient compliance with PROMs improves our ability to provide targeted interventions and information to specific patient populations with the aim of enhancing inclusiveness and representation of population in the registry. LEVEL OF EVIDENCE: Level III.

Increased risk for early revision with quadriceps graft compared with patellar tendon graft in primary ACL reconstructions.

PURPOSE: Bone patella-tendon bone (BPTB) and hamstring tendon (HT) autografts are the most used grafts in primary anterior cruciate ligament (ACL) reconstructions (ACLR) in Norway. Quadriceps tendon (QT) autograft has gained more popularity during the past years. The purpose of this study is to compare revision rates and patient-reported outcomes of primary QT with BPTB and HT autograft ACL reconstructions in Norway at 2-year follow-up. It was hypothesized that there would be no difference in 2-year revision rates between all three autografts. METHODS: Data included primary ACLR without concomitant ligament surgeries, registered in the Norwegian Knee Ligament Register from 2004 through 2021. Revision rates at 2 years were calculated using Kaplan-Meier analysis. Hazard ratios (HR) for revision were estimated using multivariable Cox regression analysis with revision within 2 years as endpoint. Mean change in patient-reported outcome was recorded preoperatively and at 2 years through the Knee Injury and Osteoarthritis Outcome Score (KOOS) subcategories 'Sport' and 'Quality of Life' was measured for patients that were not revised and analysed with multiple linear regression. RESULTS: A total of 24,790 primary ACLRs were identified, 10,924 with BPTB, 13,263 with HT and 603 with a QT graft. Patients in the QT group were younger (23.5 years), more of them were women (58.2%) and over 50% had surgery <3 months after injury. The QT group had the highest prevalence of meniscal injuries (61.9%). Revision estimates at 2-years were 3.6%, 2.5% and 1.2% for QT, HT and BPTB, respectively (p < 0.001). In a Cox regression analysis with QT as reference, BPTB had a lower risk of revision (HR 0.4, 95% Cl 0.2-0.7, p < 0.001). No significant difference was observed in the revision risk between QT and HT (HR 1.1, 95% Cl 0.7-1.8, n.s.). The two most common reported reasons for revision were: traumatic graft rupture and nontraumatic graft failure. There were no differences between the groups in change of KOOS in subcategories 'Sport' and 'Quality of Life' at 2-years follow-up. CONCLUSION: The 2-year risk of revision after ACLR with QT was higher than BPTB and similar to HT. No difference was found between the groups in patient-reported outcomes. This study provides valuable insights for both surgeons and patients when making decisions about the choice of autografts in primary ACL reconstructions. LEVEL OF EVIDENCE: Level II.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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 OF EVIDENCE: Level III, Therapeutic III, retrospective cohort study.

No difference in clinical outcome between quadriceps tendon anterior cruciate ligament reconstruction with and without bone block: Results from the Danish Knee Ligament Registry.

PURPOSE: The quadriceps tendon (QT) has recently gained increasing interest as an anterior cruciate ligament reconstruction (ACLR) graft due to minimally invasive harvesting techniques and low donor site morbidity. QT grafts can be used both with a patella bone block and as complete soft tissue grafts. However, it is unknown whether the QT graft type affects clinical outcomes. This study used data from the Danish Knee Ligament Reconstruction Registry (DKRR) to compare revision rates, knee stability and subjective clinical outcomes in patients who underwent ACLR with QT graft with bone block (QT-B) or soft tissue only (QT-S). METHODS: Patients who underwent primary ACL reconstruction with QT autografts documented in the DKRR were included and divided into the QT-B (n = 925) and QT-S (n = 659) groups. The clinical outcome was evaluated using objective-instrumented knee stability, pivot shift test, knee injury osteoarthritis outcome score (KOOS) and Tegner activity scores for the two cohorts performed at the 1-year follow-up. The overall revision rates were determined as well. RESULTS: Revision rates at 2 years were equally low in both graft groups at 2.8%. Similarly, post-operative knee laxity was equal at 1.5 (1.4) and 1.6 (1.4) mm side-to-side laxity, respectively. However, QT-B exhibited a reduced post-operative positive pivot shift of 22% compared with 31% for QT-S. Although the subjective outcomes were equal for the KOOS and Tegner activity scale scores at the 1-year follow-up, reduced improvements in KOOS were observed for QT-B compared to QT-S. CONCLUSION: ACL with a QT autograft harvested either with a bone block or as a soft tissue graft exhibited comparable revision rates and sagittal knee stability. Furthermore, ACL reconstruction using a QT graft with a bone block achieved better rotational stability with less pivot shift than ACL reconstruction using complete soft tissue QT grafts. LEVEL OF EVIDENCE: Level III.

Similar two-year improvement in patient-reported outcomes in patients 40 years and older with outerbridge grade III and IV lesions following ACL reconstruction.

PURPOSE: This study aims to evaluate clinical and patient-reported outcome measures (PROMs) of patients 40 years and older that underwent anterior cruciate ligament reconstruction (ACLR) and determine the influence of preexisting arthritis and chondral wear on ACLR outcomes. We hypothesized that patients aged 40+ with ACLR would have excellent clinical outcomes and PROMs regardless of preexisting arthritic changes. METHODS: A total of 118 patients were included. Patients aged 40 years and older who underwent ACLR in a single healthcare system between 2009 and 2016 were eligible. Outcomes assessed include Knee Injury and Osteoarthritis Outcome Scores (KOOS), Single Assessment Numeric Evaluation (SANE) scores, intraoperative Outerbridge grading, preoperative Kellgren-Lawrence (KL) grading and postoperative complication rates over a 2-year period. RESULTS: Average increase in KOOS and SANE scores were 21.2 ± $\pm $ 19.9 and 23.5 ± $\pm $ 31.3, respectively. Patients with Outerbridge grade III and IV lesions in weight-bearing compartments had lower baseline SANE and KOOS scores than those without (47.1 ± 22.0 vs. 64.5 ± 23.6 baseline SANE and 43.1 ± 18.1 vs. 63.5 ± 15.9 baseline KOOS; p = 0.002 and p < 0.001, respectively) with no significant difference in the amount of change in SANE or KOOS scores (p = 0.111 and p = 0.165 respectively). Patients with KL-grade 2+ osteoarthritis experienced similar changes in KOOS and SANE over the 2-year period to their counterparts (p = 0.598 and p = 0.643, respectively). CONCLUSION: There is no correlation between preexisting osteoarthritic changes or chondral defects and PROs. KOOS and SANE scores both increased postoperatively. When treating older patients with an ACL tear, surgeons should consider the activity level and desires of the patient as they determine appropriate treatment. Preexisting osteoarthritis does not correlate with patient-reported outcomes for ACLR. LEVEL OF EVIDENCE: Level IV.

No significant difference in skin contamination during anterior cruciate ligament reconstruction with and without preoperative skin cleaning.

PURPOSE: This prospective study aimed to assess whether preoperative antiseptic skin cleansing reduces bacterial contamination and surgical site infections (SSI) following anterior cruciate ligament reconstruction (ACLR). We hypothesized that antiseptic cleaning would lower bacterial load, reducing contamination and early infections. METHODS: One hundred and nineteen patients scheduled for ACLR were included in this prospective, nonrandomized study. Individuals were divided into two groups. Patients in the intervention group applied octenisan® wash lotion daily for three days before surgery and used the wash solution instead of their usual shower gel. Additionally, they swiped their leg with octenisan® soaked gloves on the morning of the operation. The control group followed their usual wash routine with no specific instructions. Fluid samples were taken before surgery from the irrigation bag and at 15-min intervals from the reservoir of the sterile surgical drape during the procedure. Suture material used for the ACL graft and meniscus repair were also collected for testing. The samples were subjected to a 14-day incubation period. Follow-up included outpatient visits at 6 weeks, 12 weeks and 6 months with a final evaluation at 12 months. RESULTS: Contamination rates showed no significant difference between the control and intervention groups. The mean contamination rate in the control group was 6.4% (n = 22) and 6.6% (n = 24) in the intervention group (p = 0.28). At 12-month follow-up, 110 out of 119 participants were included (52 control, 58 intervention). T tests for age (p = 0.19), BMI (p = 0.66), and surgery duration (p = 0.38) showed no significant differences. No early SSI were observed in either group postoperatively. CONCLUSION: Our results indicate that the use of antiseptic wash lotion and gloves does not influence the risk of bacterial contamination during surgery. LEVEL OF EVIDENCE: Level III.

All-soft tissue quadriceps tendon autograft and bone-patellar tendon-bone autograft demonstrate no significant ACL tunnel widening: An MRI comparison.

PURPOSE: This study sought to quantify the tunnel widening associated with quadriceps tendon (QT) autograft after anterior cruciate ligament reconstruction (ACLR) and compare it to bone-patellar tendon-bone (BTB) autografts. METHODS: A retrospective review of each ACLR performed at a single academic institution from 2011 to 2021 were reviewed. Subjects with repeat ipsilateral knee magnetic resonance imaging (MRI) studies performed after ACLR were included. Two reviewers independently measured the maximum diameter of the femoral and tibial tunnels 1 cm from the aperture. Tunnel widening was calculated as the difference between the initial drilled diameter and the measured diameters. RESULTS: Seventy-five patients (38 BTB and 37 QT autografts) were identified including 42 females and 33 males. With respect to graft type (QT vs. BTB), there was no statistically significant difference in median patient age (19.0 (16.0-31.5) years vs. 20.0 (16.8-30.0) years respectively; p = n.s.) or median time to MRI (12.0 [9.0-19.5] months vs. 13.0 [7.0-43.3] months respectively, p = n.s.). Mean tunnel diameter changes or widening was statistically significantly greater for QT autografts than BTB autografts at the tibial tunnel: (0.4 [±0.6] mm] vs. -0.4 [±1.1 mm; p < 0.001). Similarly, the mean tunnel diameter change was also significantly greater at the femoral tunnel for QT compared to BTB. (0.2 [±0.6] mm vs. -0.4 [±0.8] mm; p < 0.001) However, no patients with QT grafts demonstrated tibial or femoral tunnel diameters >12 mm. CONCLUSION: Although QT autografts had a statistically significant greater amount of tunnel widening compared to BTB autografts; the mean tibial and femoral net widening of 0.4 mm and 0.2 mm, respectively, does not meet previously reported clinically significant values. Thus, the tunnel widening presented in this study is unlikely to affect clinical outcomes and should not preclude the use of either graft. LEVEL OF EVIDENCE: Level III (Retrospective comparative study).

Donor age has no relevant role in biomechanical properties of allografts used in anterior cruciate ligament (ACL) reconstruction: A systematic review.

PURPOSE: Surgeons generally consider the donor age as a factor that negatively influences the quality of allograft used in anterior cruciate ligament (ACL) reconstruction, however, the available evidence does not clearly support this statement. The purpose of the study was to investigate if donor age influences the biomechanical properties of allografts used in ACL reconstruction. METHODS: A comprehensive literature search was conducted for all relevant articles using MEDLINE (PubMed), Scopus, and Cochrane Collaboration Library, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Studies including the analysis of the correlation between biomechanical properties of the allografts and donor age were selected. The role of donor age was labelled as 'none' if absent, 'higher' or 'lower' if the properties were higher or lower in older specimens with respect to younger. The correlation was defined as 'weak' or 'strong' according to each study definition. RESULTS: No conflicting role of donor age was reported for modulus of elasticity, load to failure, strain, stiffness and displacement. The only parameters where the significant results were consistent were the tensile strength and the stress (low or moderate correlations). When considering the tested samples with a donor's age <65 years, a significant role of age was reported in only four out of 13 groups of graft tested (patellar tendon, fascia lata, anterior tibialis tendon and posterior tibialis tendon). CONCLUSION: The current literature did not allow to state that the donor age negatively influences the biomechanical properties of allografts, making it impossible to identify a clear age cut-off value to exclude them from ACL reconstruction procedures. LEVEL OF EVIDENCE: Level IV, systematic review.