Autograft Anterior Cruciate Ligament Research Articles

GRAFTS COMPARISON BETWEEN QUADRICEPS TENDON AUTOGRAFT VS. ALLOGRAFT FOR ANTERIOR CRUCIATE LIGAMENT REVISIOON RECONSTRUCTION: A LITERATURE REVIEW

Introduction: Anterior cruciate ligament (ACL) reconstruction is one of the most common orthopaedic surgeries performed on active people in the world. One of the most important surgical decisions is graft type for use in the reconstruction. Recently, the quadriceps tendon has gained popularity for use as a graft source for ACL reconstruction. The graft choice is broadly between an autograft or allograft. This review aims to understand the current concepts in graft comparison between quadriceps tendon autograft vs. allograft for anterior cruciate ligament revision reconstruction. Methods: This literature review study was reported following the preferred reporting items for systematic reviews and adhered to a structured review protocol. The author searched the PubMed, ScienceDirect, and British Medical Journal databases. The authors comparing selected publications reporting patient outcomes with all types of reviews or descriptions of ACL revision reconstruction and its graft being used or other related subjects. Published in English is included. The author then formulates a synthesis to support the previously determined research objectives. Results: ACL reconstruction with partial thickness soft tissue quadriceps tendon graft is a reliable option. Where there are differences in the failure rates of ACL reconstructions between allografts and autografts, these can mostly be explained by irradiated grafts. Giving sufficient radiation to achieve sterility will likely weaken grafts and make them more likely to fail; therefore, irradiating grafts is not recommended. The evidence shows no significant differences in clinical effectiveness between autografts and non-irradiated allografts. Failure rates with both grafts are now low. Discussion: The primary goals of rehabilitation after ACL reconstruction do not vary considerably based on graft type and emphasize: (1) restoration of the full range of motion, (2) normalization of quadriceps strength, (3) improvement of overall lower extremity muscle strength, and (4) re-training of movement patterns to return to pre-injury sports participation while decreasing injury risk. Achieving full motion and quadriceps strength contributes to a rapid return to normal weight bearing, gait, and activities of daily living. In the setting of revision ACL reconstruction, there are various considerations regarding graft choice due to tunnel size or position, previous usage of other grafts, and reconstructions in the other leg, which may mean that allografts would be preferred to autografts. The other population not covered sufficiently in the literature is the elite sprinting athlete, where autograft choices may be influenced by the effect of graft harvesting on their sport. However, in most cases, allograft ACL reconstruction with non-irradiated grafts is as safe but more expensive than autograft ACL reconstruction, which is preferred as it is more cost-effective. Conclusion: There is little difference in the results of ACL reconstruction with autografts or non-irradiated allografts, with any advantage being with autografts. The cost is higher with allografts. So if autografts are available, allografts are not cost-effective.

'Real world' clinical implementation of blood flow restriction therapy does not increase quadriceps strength after quadriceps tendon autograft ACL reconstruction.

To retrospectively compare strength outcomes of individuals undergoing postoperative rehabilitation following quadriceps tendon (QT) autograft anterior cruciate ligament reconstruction (ACLR) with and without blood flow restriction therapy. A retrospective review of consecutive patients undergoing ACLR with QT autograft with a minimum of two quantitative postoperative isometric strength assessments via an electromechanical dynamometer (Biodex) was included. Demographics, surgical variables and strength measurement outcomes were compared between patients undergoing blood flow restriction therapy as part of postoperative rehabilitation versus those who did not. Eighty-one (81) patients met the inclusion criteria. No differences were found in demographic and surgical characteristics between those who received blood flow restriction compared with those who did not. While both groups had improvements in quadriceps peak torque and limb symmetry index (LSI; defined as peak torque of the operative limb divided by the peak torque of the nonoperative limb) over the study period, the blood flow restriction group had significantly lower mean peak torque of the operative limb at first Biodex strength measurement (95.6 vs. 111.2 Nm; p = 0.03). Additionally, the blood flow restriction group had a significantly lower mean LSI than those with no blood flow restriction at the second Biodex measurement timepoint (81% vs. 90%; p = 0.02). No other significant differences were found between the strength outcomes measured. Results of this study show that the 'real world' clinical implementation of blood flow restriction therapy to the postoperative rehabilitation protocol following QT autograft ACLR did not result in an increase in absolute or longitudinal changes in quadriceps strength measurements. A better understanding and standardisation of the use of blood flow restriction therapy in the rehabilitation setting is necessary to delineate the true effects of this modality on strength recovery after QT autograft ACLR. Level III.

Patient Interest in Quadriceps Autograft Anterior Cruciate Ligament Reconstruction Is Increasing Over Other Autograft Options: A 12-Year Google Trends Analysis

PurposeThe purpose of this study was to use Google trends to explore differences in public interest among types of anterior cruciate ligament (ACL) autografts, specifically quadriceps tendon, patellar tendon, and hamstring tendon autografts between 2008 and 2019. MethodsData were obtained by querying Google Trends for key terms and phrases for online search data ranging from January 2008 to December 2019. Relative search volumes were created based on searches related to anterior cruciate ligament reconstruction with comparative analysis generated for search terms related to quadriceps ACL, patellar tendon ACL, and hamstring ACL autografts. Statistical analysis included linear regression analysis, comparison of quarterly search volume trends over time, and comparison of cumulative annual search volumes for 2008 versus 2019. ResultsLinear models for respective search terms terms were statistically significant for the quadriceps (p<0.001) and patellar (p 0.007) tendon autograft groups, but not the hamstring group (p 0.129). The quadriceps autograft group demonstrated a 12-year search volume trend change of 0.56, which was significantly greater than the hamstring (0.07; p <0.001) and patellar tendon (0.168; p<0.001) groups. There was no significant difference in the trend change between hamstring and patellar tendon groups (p 0.20). Percent change in cumulative relative annual search volumes between 2008 and 2019 was 112% for the quadriceps tendon group, 12.9% for the hamstring group, and 18.6% for the patellar tendon group. ConclusionThis study indicates a consistently increasing public interest in quadriceps tendon autograft for ACL reconstruction. The quadriceps autograft group demonstrated a significantly greater 12-year online search volume trend, greater linear correlation, and larger percent change between 2008 and 2019 when compared to patellar tendon or hamstring autograft groups.

Primary All-Soft Tissue Quadriceps Tendon Autograft Anterior Cruciate Ligament Reconstruction With Suture Tape Augmentation Resulted in Satisfactory Patient Outcomes and a Low Graft Failure Rate in High School and Collegiate Athletes

To evaluate ≥2-year patient outcomes after primary all-soft tissue quadriceps tendon autograft (ASTQ) anterior cruciate ligament reconstruction (ACLR) with suture tape augmentation (STA) in skeletally mature high school and collegiate athletes. All high school and collegiate athletes who underwent primary ASTQ ACLR with STA with a minimum of 2-year follow-up were analyzed retrospectively. Patients were administered validated patient-reported outcome measures (PROMs) pre- and postoperatively. The minimal clinically important difference was calculated for each PROM based on this study population and applied to the individual patient. Return to sport, subsequent surgical intervention including contralateral ACLR, and KT-1000 arthrometer measurements for knee laxity were collected. Complications were assessed by physical examination, radiologic studies, or obtained via telephone. In total, 60 patients were included in the final data analysis, with a mean age of 16.8 years (95% confidence interval 13-23) and mean final follow-up of 37.1 months (95% confidence interval 33.1-41.1). Twelve patients (20%) required subsequent surgery on the ipsilateral knee, which included 7 patients having a subsequent meniscal procedure and 3 patients who underwent arthrolysis. None sustained a graft failure, and 6 patients sustained a contralateral ACL injury necessitating surgery. All PROMs improved at the final follow-up (P < .001). In addition, KT-1000 arthrometer measurements significantly improved postoperatively at 1-year clinical follow-up (P < .001). Most patients obtained the minimal clinically important difference thresholds for each PROM at the final follow-up. There were 48 patients (80%) who participated in pivoting sports. The return-to-sport rate at same level was 54 patients (90%), with 6 patients (10%) not returning to the same level because of graduation. ASTQ ACLR with STA in a young athletic patient population may result in a low graft failure rate while maintaining satisfactory patient outcomes at short-term follow-up, including a return to sport at the same level of 90%. Level IV, retrospective case series.

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

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. 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 recordedpreoperatively 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. 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. 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 II.

The Correlation Between Graft Size and Graft Failure in Hamstring Autograft Anterior Cruciate Ligament Reconstruction.

Previous studies have investigated various factors that contribute to graft failure in hamstring anterior cruciate ligament (ACL) reconstruction. However, there is debate about the potential advantages of increasing graft diameters beyond 8 mm. In this retrospective cohort study (level of evidence III), we investigated whether increasing graft sizes beyond 8 mm diameter showed any advantages in reducing the risk ofgraft failure. We utilized univariate Kaplan-Meier analysis and Cox proportional hazard (PH) regression models to compare the risk of failure in the different patient groups. Mutual adjustment was performed for age, gender, body mass index (BMI), and graft strands.Graft sizes ranging between 8 and 10 mm were assessed for their association with graft failure, alongside examining the impact of graft strands, age, and BMI on graft failure. A total of 487 patients underwent hamstring autograft ACL reconstruction at our hospital between January 2016 and December 2020. Our analysis indicated that among patients undergoing hamstring autograft ACL reconstruction, the risk of graft failure was 1.64 times higher for patients with a graft size between 8.5 and 9 mm (95% CI 0.36-7.43, p=0.483) and 2.19 times higher for patients with a graft size between 9.5 and 10.5 mm (95% CI 0.42-11.31, p=0.384) compared to those with an 8 mm graft. However, there was weak evidence against the null hypothesis. Conclusion: These findings suggest that there is no benefit to increasing graft sizes past 8 mm and that other factors, like surgical technique, should be considered when assessing the risk of graft failure in patients undergoing ACL reconstruction.

Low Preoperative Brief Resilience Scale Scores Are Associated With Inferior Preoperative and Short-Term Postoperative Patient Outcomes Following Primary Autograft Anterior Cruciate Ligament Reconstruction

To assess preoperative Brief Resilience Scale (BRS) scores as they relate to postoperative patient outcomes following primary autograft anterior cruciate ligament reconstruction (ACLR). All patients who underwent primary autograft ACLR from 2016 to 2021 and had a patient-reported follow-up of 1 year and a clinical follow-up of 6 months were included in final data analysis. Patients completed validated PROMs pre- and postoperatively. All patients were objectively assessed with range of motion (ROM) and KT-1000 arthrometer testing. Return to sport (RTS) data were obtained for all applicable patients. Patients were divided into 3 groups based on ± ½ the standard deviation for the mean preoperative BRS score. In total, 170 patients who underwent primary autograft ACLR with a mean age of 20.1 years (range, 13-57 years) and a mean final follow-up time of 2.9 years (range, 1.0-5.8 years) were included in the final analysis. The mean preoperative BRS scores for the high-resilience (HR, n= 67), average-resilience (AR, n= 42), and low-resilience (LR, n= 61) groups were 28.1 (95% CI, 27.8-28.9), 24.5 (95% CI, 24.3-24.6), and 21.1 (95% CI, 20.5-21.7), respectively (P < .001). The HR group demonstrated significantly higher preoperative and postoperative patient-reported outcome measures (PROMs) compared to the AR and LR groups, with more differences seen with the LR group. The HR group demonstrated better knee extension in postoperative month 3 compared to the LR group (0.6° [95% CI, -1.2° to 0.1°] vs -2.3° [95% CI, -3.3° to -1.3°], P= .006). The HR group demonstrated a faster RTS time compared to the LR group (6.4 months [95% CI, 6.1-6.7] vs 7.6 months [95% CI, 7.1-8.1], P= .002). No differences were seen in RTS rate, knee flexion, or KT-1000 arthrometer measurements between the 3 groups. Low preoperative BRS scores were associated with inferior PROMs preoperatively and in the short-term postoperative period compared to those with higher preoperative BRS scores. Additionally, patients with lower preoperative BRS scores demonstrated a higher degree of knee extension loss 3 months postoperatively as well as a slower RTS. Level III, retrospective cohort study.

Comparison of Clinical Outcomes Between Modern Augmented ACL Repair and Autograft ACL Reconstruction: A Systematic Review and Meta-analysis of Studies With Minimum 2-Year Follow-up.

Anterior cruciate ligament (ACL) reconstruction has been the gold standard for primary ACL rupture since the 1990s. In the past decade, ACL repair has received renewed attention and increased research. To compare the clinical outcomes of modern augmented ACL repair versus autograft reconstruction for ACL ruptures. Systematic review; Level of evidence, 3. A search of the PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library databases was conducted for prospective or retrospective comparative studies published between January 1, 2010, and January 3, 2023, with a minimum 2-year follow-up. Two independent reviewers performed data extraction and methodological quality assessment. Sensitivity analysis was performed to maintain the stability of results. Nine studies were included (minimum follow-up period, 24-60 months). The total sample size was 833 patients (augmented repair group: 358 patients; autograft ACL reconstruction group: 475 patients). There were 4 randomized controlled trials (level 1), 1 prospective comparative study (level 2), 2 retrospective comparative studies (level 3), and 2 case-control studies (level 3). The augmented ACL repair group attained significantly higher Lysholm score (weighted mean difference [WMD] = 1.57; 95% confidence interval [CI], 0.14-3.01; P = .03) and hamstring strength (WMD = 36.69; 95% CI, 29.07-44.31; P < .01) but had higher rates of hardware removal (odds ratio [OR] = 6.30; 95% CI, 2.44-16.23; P = .0001), reoperation (OR = 1.87; 95% CI, 1.33-2.62; P = .0003), and failure (OR = 1.58; 95% CI, 1.03-2.43; P = .0003) compared with the autograft ACL reconstruction group. No significant differences were observed between the repair and reconstruction groups regarding postoperative International Knee Documentation Committee scores, Tegner scores, knee laxity, satisfaction, ACL revisions, complications, and reoperation rather than revision. Augmented ACL repair was associated with higher rates of reoperation, hardware removal, and failure compared with autograft ACL reconstruction in studies with minimum 2-year follow-up data. However, augmented ACL repair had higher Lysholm scores and hamstring strength versus autograft ACL reconstruction.

An Isolated Midsubstance ACL Tear Repaired With the BEAR System

Background: Anterior cruciate ligament (ACL) repairs, once widely abandoned due to historically high failure rates, have recently regained interest with the development of the bridge-enhanced ACL repair (BEAR) implant, a novel arthroscopic technique that uses a resorbable protein-based implant combined with autologous blood to primarily repair a midsubstance ACL tear. This technical note presents a step-by-step surgical method for performing an isolated midsubstance ACL repair using the BEAR implant. Indications: The BEAR implant is indicated for skeletally mature patients at least 14 years of age with a complete rupture of the ACL, confirmed by magnetic resonance imaging. The complete ACL tear must have an attached stump to the tibia. Technique Description: A diagnostic arthroscopy is used to confirm complete rupture of the ACL and presence of residual tibial stump. A self-retrieving suture passage device is used to whipstitch a total of 6 passes with #2 Vicryl suture from distal to proximal through the residual stump. A notchplasty followed by femoral and tibial tunnels is created in a standard fashion. An Endobutton, soaked in a bacitracin solution, is then loaded with the sutures that were previously passed through the residual ACL stump and then through the femoral tunnel and cinched down to bone. The 4 suture ends that are coming from the Endobutton are then passed through the BEAR implant with the use of a Keith needle and shuttled through the tibial tunnel. The BEAR implant is hydrated with 15 cc of the patient's blood and is shuttled through the anteromedial portal with the knee in full extension. The 4 tibial sutures passed through the graft and tibial tunnel are passed, and tensioned to the proximal tibial with a second Endobutton. Standard closure and dressings are applied. Results: This new surgical implant and technique have shown noninferiority to ACL autograft reconstruction with respect to the International Knee Documentation Committee and anteroposterior laxity, with improved hamstring strength and decreased incidence of contralateral ACL tears at 2 years postoperative. Discussion/Conclusion: While initial data remain promising, future long-term designed studies are needed to determine the clinical efficacy of the BEAR technique, particularly comparing itself with bone-patellar tendon-bone autograft ACL reconstruction. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Anthropometrics Correlation of Peroneus Longus and Hamstring Autograft for Anterior Cruciate Ligament: A Cross-sectional Study

Introduction: The success of anterior cruciate ligament (ACL) reconstruction is highly correlated with the autograft diameter from either peroneus longus or hamstring. However, it is difficult to predict the graft diameter for ACL reconstruction preoperatively. Thus, this study is aimed to investigate the potential of using anthropometric measurements to predict autograft diameter. Methods: A cross-sectional study was conducted using a consecutive sampling from January 2016 until December 2021 in Sanglah General Hospital, Denpasar Bali. We recorded patients’ characteristics including gender, age, body weight, height, and Body Mass Index (BMI) preoperatively. We measured peroneus longus and hamstrings grafts diameter intraoperatively and analyzed data using Pearson correlation. Results: Eighty-nine patients met inclusion criteria with 49 patients in receiving peroneus longus autograft and 40 patients receiving hamstring autograft. The peroneus longus group includes 36 males and 13 females while the hamstring group include 19 males and 21 females. Basic demographic characteristics of peroneus longus and hamstring groups, respectively, are as follows: age was 30.53 ± 10.86 and 32.22 ± 15.66 years; body weight 66.14 ± 10.55 and 63.80 ± 7.14 kg; height 167.31 ± 6.37 and 168.33 ± 2.49 (HT) cm; and BMI 23.59 ± 3.28 and 22.51 ± 2.48 kg/m2. Intraoperative peroneus longus and hamstring diameter measurement were 7.56 ± 1.21 and 6.59 ± 0.45, respectively. Pearson correlation showed significant correlation between intraoperative peroneus longus diameter with BMI with p &lt; 0.05. Conclusions: Anthropometric measurement, especially BMI, has potential to be used as a cheap and reliable method to predict ACL autograft preoperatively. Future studies should focus on developing a mathematical formula to predict ACL autograft using anthropometric measurement in clinical settings. Keywords: anterior cruciate ligament, ACL reconstruction, autograft, anthropometric measurement

Hybrid Press-fit and Adjustable Button Femoral Fixation of Anterior Cruciate Ligament Semitendinosus and Bone-patellar Tendon-bone Autografts—A Technical Note

Introduction: Many fixation methods are available for anterior cruciate ligament (ACL) grafts. Adjustable buttons (ABs) are characterized by their high fixation strength but have the disadvantage of potential stretching of their linking suture material. Press-fit bone plugs provide fixation at the joint line and enhance biological graft healing. Using both is thought to result in a higher fixation strength, enhancing graft biology and transferring the fixation point to the joint line. Materials and Methods: It is the aim of this technical note to describe a certain technique of ACL graft hybrid fixation for hamstrings or bone-tendon-bone grafts, using AB combined with bone grafting of the femoral and tibial tunnels with press-fit bone plugs or bone chips. Discussion: ABs are commonly used fixation devices for ACL grafts. AB also allows the surgeon to tighten the ACL graft in full or near full extension. The ultimate load to failure of AB has the potential disadvantage of rendering the ACL graft progressively slack. AB augmented with press-fitting bone plugs enhances biological potentials, adds to fixation strength, and transfers the fixation level of the graft from the outer femoral cortex to the joint line. Conclusion: Hybrid AB and bone plug fixation of ACL autografts, whether hamstrings or bone-tendon bone, optimizes ACL graft fixation by gaining advantages and omitting the disadvantages of both techniques.

Outcomes of Anterior Cruciate Ligament Reconstruction With Independently Tensioned Suture Tape Augmentation at 5-Year Follow-up

Background: Reconstruction using autograft remains the gold standard surgical treatment for anterior cruciate ligament (ACL) injuries. However, up to 10% to 15% of patients will suffer a graft failure in the future. Cadaveric studies have demonstrated that the addition of suture tape augmentation to ACL autograft constructs can increase graft strength and reduce elongation under cyclical loading. Purpose/Hypothesis: This study aimed to investigate the clinical outcomes and rerupture rates after ACL reconstruction (ACLR) with suture tape augmentation. We hypothesized that augmentation with suture tape would lead to lower rerupture rates. Study Design: Case series; Level of evidence, 4. Methods: Patients undergoing primary ACLR using hamstring or patellar tendon autografts augmented with suture tape between 2015 and 2019 were recruited prospectively. Patients with multiligament injuries or a concomitant lateral extra-articular procedure were excluded. Patients were observed in person for 6 months, and patient-reported outcome measures (PROMs) were collected at 2 and 5 years postoperatively. All patients were contacted, and records were reviewed to determine the incidence of graft failure. PROMs collected were as follows: Knee injury and Osteoarthritis Outcome Score (KOOS), Veterans RAND 12-Item Health Survey (VR-12), Tegner and Marx activity scores, and visual analog scale for pain (VAS). Results: A total of 97 patients, with a mean age of 34.7 (±13.4) years, were included (76% men; 52 hamstring and 45 patellar tendon grafts). The mean graft diameter was 8 (±1) mm. There was 1 rerupture (1.1%) out of the 90 patients who were contactable at a mean of 5 years postoperatively. Median KOOS scores at 2 years were as follows: Pain, 94; Symptoms, 86; Activities of Daily Living, 99; Sport and Recreation, 82; and Quality of Life, 81. The postoperative scores were significantly higher than the preoperative scores (P < .001). The VR-12 Physical score improved from 43 preoperatively to 55 at 2 years and remained at 56 at 5 years. The VAS pain, Tegner, and Marx scores were 0, 6, and 9, respectively, at 2 years postoperatively. There was no difference in PROMs between graft types. Conclusion: This study demonstrates encouraging results of suture tape augmentation of autograft ACLR for both hamstring and patellar tendon grafts. The failure rate of 1.1% at a mean follow-up of 5 years is lower than published rates for reconstruction, and PROMs results are satisfactory. The technique is safe to use and may permit a return to the preinjury sporting level with a lower chance of reinjury.

Strength symmetry after autograft anterior cruciate ligament reconstruction

ObjectiveTo compare postoperative isometric quadriceps strength indices (QI%) and hamstring strength limb symmetry indices (HI%) between partial thickness quadriceps tendon (pQT), full thickness quadriceps tendon (fQT), and bone-patellar-tendon bone (BPTB) autograft anterior cruciate ligament reconstruction (ACLR). MethodsPatients with primary ACLR with pQT, fQT, or BPTB autograft with the documentation of quantitative postoperative strength assessments between 2016 and 2021 were included. Isometric Biodex data, including QI% and HI% (calculated as the percentage of involved to uninvolved limb strength) were collected between 5 and 8 months and between 9 and 15 months postoperatively. ResultsIn total, 124 and 51 patients had 5–8- and 9–15-month follow-up strength data, respectively. No significant difference was detected between groups for sex. However, patients undergoing fQT were found to be older than those undergoing BPTB (24.6±7 vs 20.2±5; ​p = 0.01). There were no significant differences in the number of concomitant meniscus repairs between the groups (pQT vs. fQT vs. BPTB). No significant differences were detected in median (min–max) QI% between pQT, fQT, and BPTB 5–8 months [87 ​% (44%–130 ​%), 84 ​% (44%–110 ​%), 82 ​% (37%–110 ​%) or 9–15 months [89 ​% (50%–110 ​%), 89 ​% (67%–110 ​%), and 90 ​% (74%–140 ​%)] postoperatively. Similarly, no differences were detected in median HI% between the groups 5–8 months or 9–15 months postoperatively. ConclusionThe study was unable to detect differences in the recovery of quadriceps strength between patients undergoing ACLR with pQT, fQT, and BPTB autografts at 5–8 months and 9–15-months postoperatively. Level of evidenceIII.

Clinical and Patient-Reported Functional Outcome of Semitendinosus Autograft Anterior Cruciate Ligament Reconstruction With FiberTape® InternalBrace™ All-Inside Technique: A Prospective Study.

The purpose of this study is to report the early one-year clinical and patient-reported functional outcomes of semitendinosus autograft anterior cruciate ligament reconstruction with the FiberTape® InternalBrace™ all-inside technique. The patient-reported functional outcomes and clinical outcomes were analyzed prospectivelyfollowingthe treatment of 324 unilateral ACL rupture cases with the FiberTape® InternalBrace™ Technique. Patient-reported outcome measures (KOOS scores, WOMAC scores, VAS score, and IKDC score) and clinical examinations like pre-operative and post-operative pivot shift, Lachman test, and range of motion (ROM) were conducted. These tests and examinations were recorded for each patient before surgery and at 3, 6, and 12 months after surgery. Secondary outcomes like re-rupture, infection, synovitis, or limited range of motion were noted. The mean follow-up period was18±4.5 months (range: 12-24 months). Out of a total of 324 cases, 37 cases (11.4%) could not be followed up. 158 patients (55.1%) were male and 129 were female (44.9%). Preoperative mean KOOS pain value, KOOS symptoms, KOOS ADLs, KOOS sport and recreation, and KOOS quality of life were 77.05, 78.69, 84, 21, 89.7, and 57, respectively. All KOOS subsections increased significantly at one-year to 98.37, 99.09, 98.95, 99.02, and 99.30 (p<0.0001), respectively. Mean preoperative WOMAC pain, WOMAC stiffness, and WOMAC function were 76.4, 65.2, and 74.1 and increased significantly at one-year to 94.5, 89.6, and 98.2 (p<0.0001), respectively. There was a significant decrease in VAS for pain from 2.93 before surgery to 0.12 (p<0.0001) at one year. The IKDC score significantly changed from a pre-treatment value of 50.9 to 96.2 (94.5-97.8) at a follow-up of one year. The Lysholm score at 12-months was significant at 95 (93.1-96.9), p<0.05. Post-operative Lachman test values decreased significantly, which meant decreased laxity, from 1.98 (1.89-2.07) pre-operative to 1.60 (1.57-1.62) p<0.05 at one-year post-operative. At one-year follow-up, 276 patients (96%) had fully recovered. It was concluded that the FiberTape® InternalBrace™ technique for ACL reconstruction provides orthopedic surgeons with an effective alternative technique to conventional methods of surgery and also reduces the overall time to recovery for patients, thereby allowing them to return to sports faster. Level 4.

Evidence of Bacterial Metabolism in Synovial Fluid of Patients With Graft Failure After Anterior Cruciate Ligament Reconstruction: A Microbiological Comparison of Primary Anterior Cruciate Ligament and Hamstring Tendon Autograft Ruptures

To investigate whether the bacterial presence in a primary ruptured native anterior cruciate ligament (ACL) differs from that in a ruptured hamstrings ACL autograft and whether low-grade infections cumulatively can be detected in the case of graft failure. In a retrospective case-control study with prospectively collected data, synovial fluid aspirates and tissue samples of failed ACL grafts were examined for evidence of bacterial colonization and compared to samples of the native ACL in primary ACL reconstruction (ACLR) using microbiological culture, 16S rRNA-PCR and histopathological examination. Furthermore, synovial fluid aspiration was investigated for possible future biomarkers for a low-grade infection. A total of 112 consecutive patients undergoing primary ACLR without history of previous surgeries to the affected knee (n= 59) and revision ACLR after reconstruction with a hamstring tendon autograft (n= 53) were recruited from one center. No patient had a history or showed clinical signs of infection. A total of 389 samples were analyzed by culture. Bacteria were detected in 9.4% of patients with a graft rupture (n= 5/53) compared to 3.4% of patients with a primary ACL rupture (n= 2/59) showing no statistical difference (P= .192). One patient with a "true" low-grade infection was found in our study population, resulting in a prevalence of 1.9% (1/53) in the graft group. The percentage of polymorphonuclear leukocytes (PMN%) as a highly sensitive marker for joint infections was significantly higher in aspirated synovial fluid of graft ruptures (27% ± 3% vs 20% ± 4%; P= .032), as well as glucose levels were significantly lower (83 mg/dL ± 2 mg/dL vs 88 mg/dL ± 2 mg/dL; P= .042). Synovial fluid obtained before revision ACLR showed a higher percentage of polymorphonuclear leukocytes and lower glucose levels compared with primary ACLR, suggesting bacterial metabolism and demonstrating that the intra-articular milieu changes significantly after ACLR. Tissue samples of ACL grafts revealed a low-grade infection in one case, although overall cultivable bacterial presence did not differ significantly when compared to samples of a native ACL. Level III, retrospective case-control study.

Anatomy of the anterior cruciate ligament and the common autograft specimens for anterior cruciate ligament reconstruction.

A thorough understanding of the anatomical properties of the native anterior cruciate ligament (ACL), as well as the native specimens that are most commonly considered as viable autograft choices for anterior cruciate ligament reconstruction (ACLR), is warranted for continuing to pursue the best-possible graft choice for patients undergoing ACLR. While a wide variety of graft choices remain available to the operating surgeon, choosing the correct graft choice remains a consideration and discussion with patients on the pros and cons of each option. This article combines a review of the current literature on the quantitative and qualitative anatomy of the native ACL and common autograft specimens with the expert consensus of the senior author on the surgically-pertinent anatomy of these structures. The purpose of this article is to review the anatomy pertaining to the native ACL, along with the distal anatomy of the hamstring tendons, patellar tendon and quadriceps tendon (QT). Multiple tendinous and ligamentous structures exist around the knee that serve as viable candidates for use as autologous grafts for ACLR, and the anatomy of these distal extents of these structures are discussed thoroughly, including bony attachments, quantitative and relational anatomy, cross sectional area, and histological features of these structures.

Poster 332: Return to Sport, Post-Operative Performance Testing, and Re-injury Rates Among Athletes Treated with Hamstring, Quadriceps, and Patellar Tendon Autograft ACL Reconstruction

Objectives: Anterior Cruciate Ligament (ACL) tears are a common sporting injury and optimal graft choice is of concern for both patients and surgeons. Few comparative studies have evaluated return to sport and reinjury rates across graft types. The purpose of the present study was to evaluate return to sport rates and reinjuries among hamstring tendon (HT), quadriceps tendon (QT), and patellar tendon (BPTB) ACL reconstructions. Methods: Recreational and competitive athletes ages 13-24 from 2010-2022 that underwent primary or revision ACL reconstruction were included. There were 837 total athletes comprised of 341 HT, 358 BPTB, and 138 QT autografts, of which 729 were primary and 108 were revision surgeries. Return to sport (RTS) rates, RTS testing results, clearance time, and reinjury rates were collected. RTS testing data included isokinetic testing of quadricep and hamstring strength and functional movement screening. A Kruskal-Wallis test was used to detect differences among continuous variables. A GLIMMIX procedure was completed for multivariate analysis to detect differences between groups after adjusting for age and activity level. Chi-square statistics and Fisher’s exact test were used for categorical variables. Odds ratio, adjusted odds ratio, and 95% confidence intervals were provided by logistic regression. All statistical analyses were performed using SAS 9.4 (Cary, NC). Statistical significance was measured at p&lt;0.05. Results: The median ages were 18 for HT and BPTB and 17 for QT (p= 0.0001). Females comprised 50.73% of HT grafts, 42.86% of BPTB grafts, and 41.30% of QT grafts. Return to previous level of play was observed in 118/130 (90.77%) HT, 124/136 (91.18%) BPTB, and 39/52 (75.00%) of QT grafts (p=0.0045); BPTB remained statistically more likely to return to previous level of play than QT after adjusting for age and activity level. RTS testing was completed in 28/341 (8.21%) HT, 142/358 (39.66%) BPTB, and 80/138 (57.97%) QT grafts (p&lt;0.001); after adjusting for age and activity level, the results remained significant. Median isokinetic quadriceps testing at 300 degrees per second was 92% for 26 HT athletes, 83% for 134 BPTB athletes, and 87% for 77 QT athletes (p= 0.0006); results remained significant following age and activity level adjustment. Median isokinetic hamstring testing at 60 degrees per second was 89% for 24 HT athletes, 101% for 135 BPTB athletes, and 100% for 79 QT athletes (p=0.0007); results remained significant after adjustment for age and activity level. The median single- leg hop ratio was 98% for 5 HT athletes, 85% for 12 BPTB athletes, and 96% for 14 QT athletes (p=0.044); after adjusting for age and activity level, results remained significant. Time to be cleared for RTS was 25.89 weeks for 179 HT athletes, 34.75 weeks for 186 BPTB athletes, and 35.74 weeks for 75 QT athletes (p &lt;0.0001) with the results remaining statistically significant following adjustment for age and activity level. ACL retear rates were 12.02% for HT, 3.07% for BPTB, and 5.07% for QT (p&lt;0.0001) with hamstring grafts remaining significantly more likely to suffer an ACL retear than BPTB grafts after adjusting for age and activity level. Conclusions: After adjusting for age and activity level, BPTB ACL autografts demonstrated a lower reinjury risk when compared to HT autografts. When comparing QT and BPTB, return to sport testing 6-9 months post-op was superior in the QT group; however, BPTB patients were more likely to return to sport. This data can help influence surgeon and patient shared decision-making models in athletes with ACL injuries.

Poster 314: Hamstring Autograft Diameter Effect on Surgical Outcome in a Prospective ACL Reconstruction Patient Cohort

Objectives: The purpose was to investigate the effect of hamstring autograft diameter on risk of graft failure and subsequent either knee surgery following ACLR in a prospective cohort. Background: Optimization of graft selection and incorporation in anterior cruciate ligament (ACL) reconstruction (ACLR) is an evolving science. Recent studies suggest hamstring tendon autograft diameter may influence outcomes in primary ACLR, with a larger diameter acting as a protective factor against ACL graft rupture. Further evidence using a prospective patient database is valuable in corroborating the association between ACL autograft diameter and patient outcomes. Methods: Prospective data was collected for a cohort of patients undergoing primary ACLR from February 2015 to February 2018. Exclusion criteria included non-hamstring graft selection, allograft augmentation, skeletally immature patients, revision ACLR, prior contralateral ACLR, and multiligament injuries. Cases from 10 fellowship-trained surgeons within a single institution were included. Recorded tunnel size was utilized as a surrogate for autograft diameter. The contribution of age, sex, BMI and operating surgeon on autograft diameter was studied via mixed effect modeling. The effect of hamstring tendon autograft diameter on risk of subsequent surgery was measured using multivariable linear regression modeling that controlled for patient and surgery characteristics including age, sex, BMI, Marx activity score, and graft diameter. Two-year outcomes were collected for incidence of subsequent surgery to either knee, including ipsilateral revision ACLR and contralateral primary ACLR. Results: Of the patients undergoing ACLR with hamstring autograft who met inclusion criteria, there was 90.5% follow up for subsequent surgery outcomes at minimum of 2 years, resulting in 381 patients. Female sex and lower BMI was associated with smaller autograft diameter and operating surgeon had a significant effect on autograft diameter. 59 patients (15.5%) had subsequent ipsilateral surgery and 27 patients (7.09%) had revision ACLR within 2 years. 29 patients (7.61%) had contralateral subsequent knee surgery and 20 patients (5.25%) had primary contralateral ACLR within 2 years. After controlling for age, sex, BMI, and baseline Marx activity score, hamstring autograft diameter was not associated with risk of all ipsilateral subsequent knee surgery (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.56 - 1.36, p = 0.536). Baseline Marx score greater than or equal to 12 was associated with risk of all ipsilateral subsequent knee surgery with OR 2.55 (CI 1.41 – 4.59, p = 0.002). After controlling for age, sex and BMI, hamstring autograft diameter was not associated with risk of revision ACLR (OR 0.71, CI 0.38 - 1.33, p = 0.286). Age was associated with risk of ipsilateral revision ACLR with OR 0.16 (CI 0.05 – 0.51, p = 0.002). After controlling for age, sex and BMI, hamstring autograft diameter was not associated with risk of all contralateral subsequent knee surgery (OR 0.89, CI 0.50 - 1.59, p = 0.703) including contralateral ACLR (OR 0.78, CI 0.39 - 1.59, p = 0.501). Age was found to be a significant prognostic variable of contralateral ACLR with OR 0.30 (CI 0.10 – 0.93, p = 0.037). No variables within the model were associated with risk of all contralateral subsequent surgery events. Conclusions: Hamstring autograft diameter greater than 8mm was not associated with risk of revision ACLR or other subsequent surgery in the ipsilateral or contralateral knee in a multivariable logistic regression analysis of a prospective patient cohort. Lower age was associated with risk of ipsilateral revision ACLR and contralateral ACLR. Baseline Marx activity score greater than or equal to 12 was associated with risk of all subsequent ipsilateral knee surgery. [Table: see text][Table: see text][Table: see text][Table: see text]

Autograft-Only and Allograft-Augmented Hamstring Autograft Have Similar Failure Rates After Anterior Cruciate Ligament Reconstruction

PurposeTo compare failure rates and clinical outcomes after hamstring autograft anterior cruciate ligament (ACL) reconstruction with and without allograft augmentation by a single surgeon otherwise using the same surgical technique.MethodsThis was a retrospective analysis with prospectively collected patient-reported outcomes of primary hamstring autograft ACL reconstruction with and without allograft augmentation performed in a military population by a single surgeon. The primary outcome measure was graft failure, defined as graft rupture confirmed by use of magnetic resonance imaging scans and/or revision ACL reconstruction. The secondary outcome measure was the postoperative Knee Injury and Osteoarthritis Outcome Score.ResultsThis study included 112 patients with a mean follow-up period of 65.3 months. In patients with a graft diameter of 8 mm or greater, there was no difference in failure rates (9.4% for autograft only vs 6.3% for hybrid, P = .59). There was a higher failure rate in patients in the autograft-only group with a graft diameter of less than 8 mm (29.4%) when compared with the hybrid graft group (6.3%, P = .008). There were no hybrid grafts less than 8 mm in diameter. There were no differences in the Knee Injury and Osteoarthritis Outcome Score between groups as long as the graft diameter was 8 mm or greater.ConclusionsIn patients undergoing hamstring ACL reconstruction, there was no significant difference in graft failure rates or outcome scores between autograft only and autograft with allograft augmentation as long as grafts were 8 mm or greater. High failure rates were seen when the graft diameter was less than 8 mm.Level of EvidenceLevel III, retrospective cohort study. To compare failure rates and clinical outcomes after hamstring autograft anterior cruciate ligament (ACL) reconstruction with and without allograft augmentation by a single surgeon otherwise using the same surgical technique. This was a retrospective analysis with prospectively collected patient-reported outcomes of primary hamstring autograft ACL reconstruction with and without allograft augmentation performed in a military population by a single surgeon. The primary outcome measure was graft failure, defined as graft rupture confirmed by use of magnetic resonance imaging scans and/or revision ACL reconstruction. The secondary outcome measure was the postoperative Knee Injury and Osteoarthritis Outcome Score. This study included 112 patients with a mean follow-up period of 65.3 months. In patients with a graft diameter of 8 mm or greater, there was no difference in failure rates (9.4% for autograft only vs 6.3% for hybrid, P = .59). There was a higher failure rate in patients in the autograft-only group with a graft diameter of less than 8 mm (29.4%) when compared with the hybrid graft group (6.3%, P = .008). There were no hybrid grafts less than 8 mm in diameter. There were no differences in the Knee Injury and Osteoarthritis Outcome Score between groups as long as the graft diameter was 8 mm or greater. In patients undergoing hamstring ACL reconstruction, there was no significant difference in graft failure rates or outcome scores between autograft only and autograft with allograft augmentation as long as grafts were 8 mm or greater. High failure rates were seen when the graft diameter was less than 8 mm.

Two-Dimensional Magnetic Resonance Imaging in Preparation for Autograft Anterior Cruciate Ligament Reconstruction Demonstrates Quadriceps Tendon Is Thicker Than Patellar Tendon

The purpose of this study was to assess patellar tendon (PT) and quadriceps tendon (QT) thickness on preoperative magnetic resonance imaging (MRI), in both the sagittal and axial planes, at multiple points along each tendon, and to correlate these findings to anthropometric patient data before anterior cruciate ligament (ACL) surgery. Patients who underwent PT or QT autograft ACL reconstruction between 2020 and 2022 and who had preoperative MRIs with adequate visualization of the proximal QT and distal PT were retrospectively identified. Patient demographics were recorded (age, height, weight, sex, injury side). Preoperative MRI measurements were performed by 3 independent examiners using standardized protocol. Preoperative MRI measurements were the QT anterior-posterior (AP) thickness at 1, 2, and 4 cm from the proximal patella on axial and sagittal MRI images at the central aspect of the tendon, as well as PT AP thickness at 1, 2, and 4 cm from the distal patella on axial and sagittal MRI images at the central aspect of the tendon. Forty-one patients (21 females, 20 males) were evaluated, with a mean age of 33.4 years. The quadriceps tendon was significantly thicker than the patellar tendon at all measured locations (P < .0001) with average QT versus PT thickness (in mm) at each level sagittal 1 cm (7.13 vs 4.35), sagittal 2 cm (7.41 vs 4.44), sagittal 4 cm (7.26 vs 4.81), axial 1 cm (7.35 vs 4.50), axial 2 cm (7.63 vs 4.47), axial 4 cm (7.46 vs 4.62), respectively. There were no significant correlations between tendon size and patient body mass index. The quadriceps tendon is significantly thicker than the patellar tendon at 1, 2, and 4 cm from the patella in both males and females based on preoperative MRI before ACL surgery. Investigating the thickness of the tendons available for autograft harvest before surgery will give us a better understanding of tendon anatomy in the setting of ACL reconstruction.