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Background: Because grafts are made in 0.5-mm increments clinically for anterior cruciate ligament (ACL) reconstruction, it is important to clarify how the failure rate decreases as the diameter increases. Moreover, it is important to know whether even a slight increase in the graft diameter decreases the risk of failure. Hypothesis: The risk of failure decreases significantly with each 0.5-mm increase in hamstring graft diameter. Study Design: Meta-analysis; Level of evidence, 4. Methods: The systematic review and meta-analysis have estimated the diameter-specific failure risk for each 0.5-mm increase in ACL reconstruction using autologous hamstring grafts. We searched for studies describing the relationship between graft diameter and failure rate published before December 1, 2021, in leading databases, such as PubMed, EMBASE, Cochrane Library, and Web of Science, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We included studies using single-bundle autologous hamstring grafts to investigate the relationship between failure rate and graft diameter of 0.5-mm intervals with >1-year follow-up. Then, we calculated the failure risk caused by 0.5-mm differences in autologous hamstring graft diameter. Assuming Poisson distribution for the statistical model, we employed an extended linear mixed-effects model in the meta-analyses. Results: Five studies containing 19,333 cases were eligible. The meta-analysis revealed that the estimated value of the coefficient of diameter in the Poisson model was −0.2357 with a 95% CI of −0.2743 to −0.1971 (P <.0001). With every 1.0-mm increase in diameter, the failure rate decreased by 0.79 (0.76-0.82) times. In contrast, the failure rate increased by 1.27 (1.22-1.32) times for each 1.0-mm decrease in diameter. The failure rate significantly decreased with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm from 3.63% to 1.79%. Conclusion: The risk of failure decreased correspondingly with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm. Failure is multifactorial; however, increasing the graft diameter as much as possible to match each patient's anatomic space without overstuffing is an effective precaution that surgeons can take to reduce failures. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association between hamstring autograft diameter and ACL graft failure rate in athletes who successfully returned to pivoting sports after ACL reconstruction. Methods: Retrospective evaluation of ACL graft failure rates in athletes who underwent ACL reconstruction with all-inside hamstring autograft and successfully returned to pivoting sports following postoperative rehabilitation. Athletes were divided into a ≤ 8 mm group and a > 8 mm group. Data about return to pivoting sports and ACL graft failures after ACL reconstruction were collected via a digital questionnaire. ACL graft failures were in all cases confirmed by an orthopaedic surgeon and/or MRI. The association between hamstring autograft diameter and ACL graft failure rate was investigated using a Fisher's exact test in the subgroup of athletes who completed the digital questionnaire and returned to pivoting sports. Results: Two-hundred and twenty-nine of the 422 athletes who completed the digital questionnaire (54.2%) returned to a pivoting sport and were included for final analyses. Ninety-seven (42.4%) of the athletes who returned to sport were in the ≤ 8 mm group (8 graft failures) and 132 (57.6%) in the > 8 mm group (10 graft failures). There were significantly more women (49.5 and 13.6% respectively; p < 0.001) and significantly smaller (1.75 and 1.81 m respectively; p < 0.001), lighter (72.2 and 79.6 kg respectively; p < 0.001) and younger (23.6 and 26.1 years old respectively; p = 0.015) athletes in the ≤ 8 mm group compared to the > 8 mm group. There was no significant association between hamstring autograft diameter and ACL graft failure rate. Conclusion: A hamstring autograft diameter of ≤ 8 mm is a legitimate option for smaller, lighter and female athletes without increasing the risk for ACL graft failure. Level of evidence: III. [ABSTRACT FROM AUTHOR]

BACKGROUND: The functional rehabilitation of patients after anterior cruciate ligament reconstruction is related to various factors, such as different reconstruction methods, anterior cruciate ligament graft shape and diameter, and different types of anterior cruciate ligament graft. Related clinical studies suggest that the diameter of the graft is 7-10 mm; the larger the diameter, the better the knee joint recovery function and the fewer complications. OBJECTIVE: To study the relationship between graft diameter and knee function in anterior cruciate ligament reconstruction. METHODS: A total of 90 patients with anterior cruciate ligament rupture in Sanshui Hospital of Foshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine from March 2018 to January 2020 were selected. Autogenous tendons were used for anterior cruciate ligament reconstruction. According to the diameter size of the autologous tendon braided in the knee joint, they were divided into 7 mm group (n=26), 8 mm group (n=43) and 9 mm group (n=21). The patients were followed up for 1 year. IKDC and Lysholm were used to assess knee function. The stability of knee joint was evaluated by KT- 1000 and posterior cruciate ligament index. The protocol was approved by the Ethics Committee of Sanshui Hospital of Foshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine. RESULTS AND CONCLUSION: (1) IKDC score and Lysholm score of the 8 mm group were higher than those of the 7 mm group and the 9 mm group (P < 0.05). There was no significant difference between the 7 mm group and the 9 mm group in the IKDC score and Lysholm score (P > 0.05). (2) Tibial anteversion distance in KT-1000 test and the posterior cruciate ligament index of the 7 mm group were greater than those of the 8 mm group and 9 mm group (P < 0.05). The posterior cruciate ligament index of the 8 mm group was less than that of the 9 mm group (P < 0.05). There was no significant difference in tibial anteversion distance in KT-1000 test between the 8 mm group and 9 mm group (P > 0.05). (3) Results suggest that in patients with simple anterior cruciate ligament injury of the knee, the reconstructed diameter of 8 mm and 9 mm has better stability of the knee joint. The reconstructed diameter of 8 mm has better function. Smaller or larger diameter may affect the functional recovery of patients with certain factors. [ABSTRACT FROM AUTHOR]

The size of the anterior cruciate ligament (ACL) often varies between individuals, but such variation is not typically considered during ACL reconstruction (ACLR). This study aimed to explore how the size of the ACL affects the selection of a suitable graft diameter. A finite element model of a human knee was implanted with intact ACLs of different dimensions (0.95, 1 and 1.05 times the size of the original ACL) and with grafts of different diameters, to simulate ACLR (diameter 7.5–12 mm in 0.5 mm increments). The knee models were flexed to 30° and loaded with an anterior tibial load of 103 N, internal tibial moment of 7.5 Nm, and valgus tibial moment of 6.9 Nm. Knee kinematics (anterior tibial translation (ATT), internal tibial rotation (ITR) and valgus tibial rotation (VTR)) and ligament forces were recorded and compared among the different groups. The results showed that, compared with the intact knee, a graft diameter of 7.5 mm was found to increase the ATT and VTR, but reduce the graft force. Increasing the graft diameter reduced knee laxity and increased the graft force. A 10% increase in the size of the ACL corresponded to a 3 mm larger graft diameter required to restore knee stability and graft force after ACLR. It was concluded that the graft diameter should be selected according to the dimensions of the native ACL, for better restoration of knee functionality. This study may help to improve the clinical treatment of ACL ruptures. [ABSTRACT FROM AUTHOR]

Introduction Anterior cruciate ligament (ACL) reconstruction with quadrupled hamstring tendon autograft is a safe and reproducible surgery with good functional outcomes. Currently there is no consensus on capability of graft diameter planning. Objectives To investigate the influence of anthropometric data and cross-sectional area of semitendinosus (ST) and gracilis (GR) tendons according to preoperative magnetic resonance imaging (MRI) on intraoperative graft diameter. Material and methods The study included 111 consecutive patients (69 men and 42 women), who underwent ACL reconstruction with quadrupled hamstring autograft between 2015 to 2018. Height, weight and BMI were recorded in all patients preoperatively. Semitendinosus and gracilis tendons cross sectional areas (CSAst and CSAgr, respectively) were evaluated on preoperative MRI axial images. We also calculated doubled and quadrupled graft diameters (CSAst+gr and CSA4p, respectively) based on obtained MRI data. Collection of intraoperative data included length of each tendon separately, length and diameter of the resulting autograft. We used linear regression and Pearson correlation coefficient were used. The crosssectional areas were correlated to antropometric and intraoperative data. Using logistic regression, we determined the probability of obtaining a graft diameter of ≥ 7.5 mm. A critical level of statistical significance was set as 5 % (p ≤ 0.05). Results The median age accounted 37.4 ± 0.89 (13–58) years, height – 174.6 ± 0.84 (156–200) cm, weight – 78.5 ± 1.52 (45–120) kg, BMI – 25.6 ± 0.37 ( 18.49–41.5). Intraoperatively GR average length was 224.7 ± 3.06 (80–340) mm, ST – 256.3 ± 2.97 (160–340) mm, quadrupled graft – 111.3 ± 1.42 (80–140) mm. The most common graft diameter was 7 mm in females and 7.5 mm in males. We found strong positive correlation between graft diameter and CSA4p, СSAst+gr, CSAst, weight and height. Linear regression showed that graft diameter was influenced by CSA4p, СSAst+gr, CSAst and height. If CSA4p was ≥ 72 mm2, the probability of obtaining a graft of ≥ 7.5 mm at the time of surgery reached 90.6 %. Conclusion CSA4p may be used as a predictive characteristic for graft diameter preoperative planning. Our findings show that graft diameter was mainly influenced by height, СSAst+gr, CSAst and CSA4p.

Purpose: The present study tested and compared the biomechanical properties of four different triplicate graft tendon techniques. Methods: 32 tripled tendons from the common extensor muscle of bovine fingers were tested on a material testing machine, passing the end loop over a metal rod of a clevis connected to the load cell on the upper side, and fixing the lower end to a clamp. The samples were divided into four groups: (A) tripled with a free end sutured only to one of the two fixed bundles (B) tripled with a free end positioned between the two fixed strands and sutured to both (C) tripled with an S-shape and all the three strands sutured together at the upper and lower extremities of the graft (D) partially quadrupled with the free end sutured together with the other three bundles at the upper extremity. Each sample was pretensioned at 50 N for 10 min and then subjected to 1000 load control cycles between 50 and 250 N. Finally, each sample was subjected to a load to failure test. Authors also present some preliminary results on the feasibility of a non-contact and full-field Thermoelastic Stress Analysis technique, based on Infrared Thermography, to evaluate the level of stress on the whole graft, and hence on each strand, during fatigue loading. Results: Eighty five percent of the samples failed at the level of the clamp. The cyclical elongation progressively decreased in all the samples and there was a simultaneous increase in stiffness. An increased stiffness was noted between Group 2 vs Group 3 and Group 2 vs Group 4 at the 500th and 1000th cycle. The failure loads were as follows: (a) 569.10 N, (b) 632.28 N, (c) 571.68 N, (d) 616.95 N. None of the parameters showed a statistically significant difference between the four groups. Conclusion: This study reported similar biomechanical behavior of four different models of tripled grafts suitable for ACL reconstruction. In addition, the biomechanics of overall tripled tendon grafts seems more affected by the viscoelastic property of the tendon itself rather than the preparation method. [ABSTRACT FROM AUTHOR]

Background: The purpose of the study was to find the effect of autologous hamstring tendon graft size on patient reported outcome (PRO) measures following Arthroscopic Anterior cruciate ligament (ACL) reconstruction. Materials and Methods: A review of prospectively collected cohort data of 90 patients who had undergone primary ACL reconstruction using hamstring tendon autograft was evaluated. Patient's age, sex, graft diameter at the time of surgery, and minimum of 2 years postoperative functional outcome were assessed using PRO measures, i.e. Tegner Lysholm Knee (TLK) Scoring Scale, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee score. Mean of the three scores was calculated along with that of graft diameter, and Pearson correlation coefficient was calculated to find the relation between graft diameter and the three-PRO measure scores independently. Two-tailed test was used to compute the statistical significance of parameter inferred from the data sheet. Results: There was a positive linear correlation between the graft diameter and three PRO measures independently; however, two-tailed tests for statistical significance were significant only for TLK Score and KOOS. Conclusion: We conclude that hamstring autograft diameter is one of the important predictor for postoperative functional outcome, and hence, a thicker diameter graft is desirable.

Background: The hamstring tendon is frequently used to reconstruct the anterior cruciate ligament (ACL), but there is a lack of consensus on the optimal method of fixation. Registry studies have shown that the type of femoral fixation device can influence the risk of revision ACL reconstruction (ACLR), but it is unclear whether the type of tibial fixation has an effect. In New Zealand, over 95% of hamstring tendon grafts are fixed with an adjustable loop suspensory device on the femoral side, with variable usage between suspensory and interference devices, with or without a sheath, on the tibial side. Purpose: To investigate the association between the type of tibial fixation device and the risk of revision ACLR. Study Design: Cohort Study; Level of evidence, 2. Methods: Prospective data recorded in the New Zealand ACL Registry were analyzed. Only primary ACLRs performed with a hamstring tendon autograft fixed with a suspensory device on the femoral side were included. A Cox regression survival analysis with adjustment for patient factors was performed to analyze the effects of the type of tibial fixation device, the number of graft strands, and graft diameter on the risk of revision. Results: A total of 6145 primary ACLRs performed between 2014 and 2019 were analyzed. A total of 59.6% of hamstring tendon autografts were fixed with a suspensory device on the tibial side (n = 3662), 17.6% with an interference screw with a sheath (n = 1079), and 22.8% with an interference screw without a sheath (n = 1404). When compared with suspensory devices, a higher revision risk was observed when using an interference screw with a sheath (adjusted hazard ratio [HR], 2.05; P =.009) and without a sheath (adjusted HR, 1.81; P =.044). The number of graft strands and a graft diameter of ≥8 mm were associated with the rate of revision on the univariate analysis; however, after adjusting for confounding variables on the multivariate analysis, they did not significantly influence the risk of revision. Conclusion: In this study of hamstring tendon autografts fixed with an adjustable loop suspensory device on the femoral side during primary ACLR, the use of an interference screw, with or without a sheath, on the tibial side resulted in a higher revision rate when compared with a suspensory device. [ABSTRACT FROM AUTHOR]

Purpose: Multi-stranded hamstring-tendon autografts have been widely used for anterior cruciate ligament reconstruction (ACLR) surgeries. Recently, smaller diameter hamstring autografts have been linked with the risk of failure or graft rupture. However, there is limited evidence concerning the optimal diameter of the hamstring autografts for ACLR. The current systematic review and meta-analysis analysed the association of ACLR failure with the diameter of hamstring autografts. Methods: A systematic search of three major scientific databases (Pubmed, EMBASE, and Cochrane library) was conducted to identify studies that presented ACLR failure-related outcomes with different diameters of hamstring autografts. The pooled data from the included studies were analysed to investigate the association between ACLR failure and the cut-off diameters of 6, 7, 8, and 9 mm. Subgroup analyses based on the level of evidence and follow-up duration were also performed at each cut-off diameter. Results: Of the 2282 studies screened, 16 reported failure rates with hamstring autografts of different diameters, 15 of which were included in the meta-analysis. A graft diameter ≥ 7 mm was associated with significantly lower ACLR failure rates than a graft diameter < 7 mm (p = 0.005), based on pooled data of 19,799 cases. Age < 20 years and higher physical activity were associated with significantly higher ACLR failure rates. Conclusion: The current systematic review suggests that the hamstring graft diameter for ACLR should be more than 7 mm considering the significantly higher failure rates with graft diameters less than 7 mm. Level of evidence: Level IV [ABSTRACT FROM AUTHOR]

Background: Over 130,000 anterior cruciate ligament (ACL) reconstructions (ACLRs) are performed annually in the United States. Previous studies have shown that circumferential preconditioning reduces the diameter of fresh-frozen allografts, but no studies have described the effect in ACL autografts used during ACLR. Purpose: To characterize the changes in the hamstring autograft diameter as a result of preparatory circumferential preconditioning. Study Design: Case series; Level of evidence, 4. Methods: A total of 135 patients with ACLR, with a median age of 15 years (interquartile range, 14-16 years; 50.4% boys), were identified in 2 pediatric hospitals. Three orthopaedic surgeons recorded hamstring autograft diameters at 2 time points during graft preparation. Hamstring tendons were prepared using a standardized procedure, tensioned to 15 to 20 lbs, and measured using cylindrical sizing guides. The graft was left with passive compression in the smallest initial rigid sizing guide for 10 minutes on both the tibial and femoral sides and then measured again immediately before implantation. Tunnels were drilled based on the second measurement of graft size. Comparisons were made between the graft diameter before and after circumferential preconditioning. A random-effects regression model and a linear regression model were performed to capture any unexplained variance on the linear predictor scale and determine correlations between demographics and graft characteristics. Results: The median initial diameter for both femoral and tibial sides was 9.5 mm. After longitudinal tension and circumferential preconditioning, the median autograft diameter of both sides decreased by 1 mm (P <.001) to 8.5 mm. In the random-effects model, decreased patient height was a significant predictor of greater reduction in graft diameter. Increased height was a significant predictor for greater initial graft diameter (average beta coefficient = 3.08; P <.01). No intraoperative complications were noted with implantation of the preconditioned grafts in smaller diameter tunnels. Conclusion: The median diameter of hamstring ACL autografts decreases by 1 mm after circumferential preconditioning within standard cylindrical sizing guides. This allowed for drilling of tunnels that were an average of 1 mm smaller without any noted intraoperative complications with graft insertion. [ABSTRACT FROM AUTHOR]

The size of the anterior cruciate ligament (ACL) often varies between individuals, but such variation is not typically considered during ACL reconstruction (ACLR). This study aimed to explore how the size of the ACL affects the selection of a suitable graft diameter. A finite element model of a human knee was implanted with intact ACLs of different dimensions (0.95, 1 and 1.05 times the size of the original ACL) and with grafts of different diameters, to simulate ACLR (diameter 7.5–12 mm in 0.5 mm increments). The knee models were flexed to 30° and loaded with an anterior tibial load of 103 N, internal tibial moment of 7.5 Nm, and valgus tibial moment of 6.9 Nm. Knee kinematics (anterior tibial translation (ATT), internal tibial rotation (ITR) and valgus tibial rotation (VTR)) and ligament forces were recorded and compared among the different groups. The results showed that, compared with the intact knee, a graft diameter of 7.5 mm was found to increase the ATT and VTR, but reduce the graft force. Increasing the graft diameter reduced knee laxity and increased the graft force. A 10% increase in the size of the ACL corresponded to a 3 mm larger graft diameter required to restore knee stability and graft force after ACLR. It was concluded that the graft diameter should be selected according to the dimensions of the native ACL, for better restoration of knee functionality. This study may help to improve the clinical treatment of ACL ruptures.

The clinical implications of changing the shape of the bone tunnel for Anterior cruciate ligament reconstruction (ACLR) is controversial and few studies have reported on the long-term prevalence for osteoarthritis. As such, this study aims to evaluate the effect of tunnel shape on joint biomechanics. Finite element models of an ACLR were constructed with different shapes (circular, oval, rounded rectangular, rectangular, and gourd-shaped) and diameters (7.5, 8.5, and 9.5 mm) for the bone tunnel. A combined loading of 103 N anterior tibial load, 7.5 Nm internal tibial moment and 6.9 Nm valgus tibial moment was applied at a joint flexion angle of 20°. Joint kinematics and the strain energy density (SED) on the articular cartilage were compared among the different groups. The results showed that conventional ACLR (circular tunnel) lead to an increase in joint kinematics over the intact joint, a lower ligament force and a higher SED on the lateral tibial cartilage. ACLR using the other tunnel shapes resulted in even greater joint kinematics, lower graft force and greater SED on the lateral tibial cartilage. Increasing the tunnel diameter better restored joint kinematics, graft force and articular SED, bringing these values closer to those from the intact knee. In conclusion, increasing the tunnel diameter may be more effective than changing the tunnel shape for restoring joint functionality after ACLR.

Several studies have identified graft diameter as a risk factor for failure following anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to evaluate the effect of graft diameter on patient reported outcome measures (PROMS) following ACLR. We performed a retrospective review of prospectively collected data using a global surgical registry. 153 of 287 patients (53.3%) had complete data for each timepoint. Effect of graft diameter, graft type, femoral tunnel drilling technique, patient age, sex, and body mass index were evaluated. At 1-year post-operatively, a 1-mm increase in graft diameter was found to correlate with a 5.7-point increase in the Knee Injury and Osteoarthritis Outcome Score (KOOS) activity of daily living score (p = 0.01), a 10.3-point increase in the sport score (p=0.003), and a 9.8-point increase in the quality of life score (p=0.013). At 2-years post-operatively, a 1-mm increase in graft size was found to be marginally correlated with KOOS symptoms and sport scores. Patients undergoing hamstring autograft ACLR, increasing graft diameter can result in improved PROMS, specifically improved KOOS subscale scores at 1 and 2-years post-operative.

Purpose: The present study was to analyze graft failure rates of hamstring tendon (HT) autografts with a cut-off graft diameter of 8 mm or 7 mm, and compare clinical outcomes between augmented small HT with an allograft and non-augmented relatively large HT in single-bundle anterior cruciate ligament reconstruction (ACLR).Methods: A literature search of PubMed, EMBASE, and the Cochrane Library was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines. Studies to assess graft failure of autologous HT ACLR were reviewed, and graft failure rates with a cut-off graft diameter of 8 mm or 7 mm were further extracted. Clinical comparative studies of ACLR between augmented small HT with an allograft and non-augmented relatively large HT autografts were also included. Results are presented as risk ratio (RR) for binary data and weighted mean difference for continuous data with 95% confidence intervals (CI).Results: Nine studies with 2243 knees were included. Four studies examined the effect of HT autograft diameter on graft failure and five studies assessed clinical outcomes of allograft augmentation to small HT autografts. No significant difference was noted in graft failure with a cut-off diameter of 8 mm. No significant difference was found between diameters > 7 and ≤ 7 mm, but a significant difference was observed between diameters ≥ 7 and < 7 mm (RR = 0.49; 95% CI 0.26-0.92, I2 = 0%, P = 0.03). A trend towards increased risk of graft failure was noted for allograft-augmented HT compared with non-augmented HT autografts (RR = 0.43; 95% CI 0.18-1.02, I2 = 0%), but no significant differences were noted in IKDC, Lysholm, and Tegner scores between these groups.Conclusion: The present study did support the use of 7 mm as a reference for cut-off diameter for small HT autografts, but not allograft augmentation to small HT autografts. These findings would guide clinical application of small HT autografts in single-bundle ACLR.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Several studies have identified graft diameter as a risk factor for failure following anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to evaluate the effect of graft diameter on patient reported outcome measures (PROMS) following ACLR. We performed a retrospective review of prospectively collected data using a global surgical registry. 153 of 287 patients (53.3%) had complete data for each timepoint. Effect of graft diameter, graft type, femoral tunnel drilling technique, patient age, sex, and body mass index were evaluated. At 1-year post-operatively, a 1-mm increase in graft diameter was found to correlate with a 5.7-point increase in the Knee Injury and Osteoarthritis Outcome Score (KOOS) activity of daily living score (P=0.01), a 10.3-point increase in the sport score (P=0.003), and a 9.8-point increase in the quality of life score (P=0.013). At 2- years post-operatively, a 1-mm increase in graft size was found to be marginally correlated with KOOS symptoms and sport scores. Patients undergoing hamstring autograft ACLR, increasing graft diameter can result in improved PROMS, specifically improved KOOS subscale scores at 1 and 2- years post-operative. [ABSTRACT FROM AUTHOR]

Purpose. This study aimed to compare the biomechanical proprieties of 4 and 5-strandgrafts. Methods. For the present study, fresh-frozen bovine common digital extensor tendons were used. Tendon grafts were prepared and sized to have a length of almost 27 cm and a cylinder 4 strand diameter of 8 mm. In half of all samples (Group A, n=12,), the graft was formed by 2 bundles duplicated around a metallic rod creating a 4-strand-tendon construct. In the other half of samples (Group B, n= 12,) 5-strand-tendon construct was created duplicating a single tendon around the rod, and tripling the other one. The grafts were preconditioned at 50 N for 10 min, followed by 1,000 cyclic loading between 50 and 250 N. Load-to-failure test was then carried out at a rate of 1 mm/s. Results. No statistically significant differences were found between two groups concerning cyclic elongation at the 500th cycle and at the final cycle. An increased stiffness was observed in the Group B during cyclic loads and at pull-out (p<0.05). Significant differences were noted at the ultimate load-to-failure between Group A (1533 ± 454 N) and Group B (1139 ± 276 N) (p< 0.05). Conclusion. This study showed that both graft construct appears to be biomechanically effective in a bovine tendon model. 5-strand-graft showed an increased stiffness and a decreased ultimate load-to-failure comparing to the 4-strand-graft construct. Biomechanically, no real benefit could be observed in the clinical setting increasing the numbers of strands used for the ACL reconstructive surgery. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) using a hamstring tendon (HT) autograft is an effective and widespread method. Recent studies have identified a relationship between the graft diameter and revision ACLR. Purpose: To evaluate the influence of the graft diameter on revision ACLR and patient-reported outcomes in patients undergoing primary ACLR using HT autografts. Study Design: Cohort study; Level of evidence, 2. Methods: A prospective cohort study was conducted using the Swedish National Knee Ligament Register (SNKLR) involving all patients undergoing primary ACLR using HT autografts. Patients with graft failure who needed revision surgery (cases) were compared with patients not undergoing revision surgery (controls). The control group was matched for sex, age, and graft fixation method in a 3:1 ratio. Conditional logistic regression was performed to produce odds ratios and 95% CIs. Univariate linear regression analyses were performed for patient-related outcomes. The Knee injury and Osteoarthritis Outcome Score (KOOS) and EuroQol 5 dimensions questionnaire (EQ-5D) values were obtained. Results: A total of 2240 patients were included in which there were 560 cases and 1680 controls. No significant differences between the cases and controls were found for sex (52.9% male), mean age (21.7 years), and femoral and tibial fixation. The mean graft diameter for the cases was 8.0 ± 0.74 mm and for the controls was 8.1 ± 0.76 mm. In the present cohort, the likelihood of revision surgery for every 0.5-mm increase in the HT autograft diameter between 7.0 and 10.0 mm was 0.86 (95% CI, 0.75-0.99; P = .03). Univariate linear regression analysis found no significant regression coefficient for the change in KOOS or EQ-5D values. Conclusion: In a large cohort of patients after primary ACLR with HT autografts, an increase in the graft diameter between 7.0 and 10.0 mm resulted in a 0.86 times lower likelihood of revision surgery with every 0.5-mm increase. This study provides further evidence of the importance of the HT autograft size in intraoperative decision making. [ABSTRACT FROM AUTHOR]

Purpose: To determine incidence and risk factors for traumatic graft rupture following primary and revision anterior cruciate ligament (ACL) reconstruction.Methods: All cases of isolated ACL reconstructions (primary or revision) performed at our institution between January 2007 and December 2010 were included. From this group of 2467 primary reconstructions (32.4 ± 12.2 years) and 448 revision reconstructions (33.0 ± 10.4 years), we identified all patients who underwent revision ACL reconstruction following traumatic graft rupture in further course and all patients who underwent contralateral primary ACL reconstruction until January 2014. Age, gender, time from index procedure and graft diameter (for hamstring autografts) were analysed in terms of being a potential risk factor for graft rupture.Results: Within a follow-up period of 5.0 ± 1.1 years (3.0-7.0), a total of 82 traumatic graft ruptures were identified, resulting in an incidence of 2.8 %. Seventy-three cases were seen following primary reconstructions (3.0 %), and nine cases following revision reconstructions (2.0 %), respectively (n.s.). Age younger than 25 years was identified as a risk factor for both groups (p = 0.001 and p = 0.008; odds ratio 6.0 and 6.4, respectively). In primary reconstruction, male patients had a higher risk of graft rupture compared with females (3.7 vs. 1.6 %; p = 0.005), and the first year after index procedure was associated with a higher risk of graft rupture compared with the following (p < 0.001). Graft diameter did not influence the risk of graft rupture. Incidence of contralateral ACL rupture was 3.1 %, which was not different to the incidence of graft rupture ipsilaterally (n.s.).Conclusion: No statistically significant differences were seen between graft rupture incidence of primary and revision ACL reconstructions. Young age (<25 years) and short time to the index procedure (especially within the first year) were confirmed as risk factors for graft rupture in both groups. Male gender was a risk factor for primary reconstructions. Graft diameter had no influence on graft rupture rates. No difference in incidence of graft rupture compared to ACL rupture on the contralateral side was apparent.Level Of Evidence: Retrospective case series, Level IV. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) reconstruction with ST autograft is sometimes unsuccessful because of harvested thin graft. Magnetic resonance imaging (MRI) can be a useful tool to evaluate the thickness of the graft. This study is performed to evaluate whether there is any correlation between diameters and cross-sectional area (CSA) of the semitendinosus tendon (ST) on the preoperative magnetic MRI and the diameter of the 4-stranded ST autograft in ACL reconstruction. Materials and Methods: Seventy patients who underwent single-bundle ACL reconstruction with 4-stranded ST for full-thickness ACL ruptures were included in this study. Anteroposterior (AP) and mediolateral (ML) diameters of ST at the levels of the joint line (JL) and femoral physeal line (PL), and also CSA at these levels were measured on T2-weighted fat-suppressed MRI examinations. The data obtained were compared with intraoperatively measured diameters of 4-stranded ST autograft. Correlations between variables were evaluated using Spearman's rho. Receiver operating characteristic and area under the curve statistics were used to evaluate the cut-off value for the correlation between 4-stranded ST graft diameter of 8 mm and CSA (mm²) on MRI. Results: On MRI measurements, no correlation was found between AP diameters at the level of the JL and 4-stranded ST diameter (P = 0.180). However, correlations were found between diameter of 4-stranded ST and ML diameter at the level of JL (P = 0.003) and PL (P = 0.002), AP diameter at the level of the PL (P = 0.009), CSA at the level of the JL (P < 0.001) and at the level of PL(P 0.001). Correlation between the diameter of 4<0.001).-stranded ST and CSA at both levels was more significant than that between AP-ML diameters of ST and diameter of autograft. The cut-off value for the 8 mm diameter CSA of 4-stranded ST was 5.9 mm² at the JL and 8.99 mm² at the PL. Conclusion: Preoperative MRI evaluation of CSA at the JL of the ST is a reliable parameter to predict graft size. Other graft alternatives should better be considered if the CSA of ST is <5.9 mm² at the level of the JL. [ABSTRACT FROM AUTHOR]

Background: Hamstring autografts for anterior cruciate ligament (ACL) reconstruction (ACLR) have become popular in the past 2 decades; however, it is difficult to predict the diameter of the harvested tendons before surgery. Previous biomechanical studies have suggested that a smaller graft diameter leads to a lower load to failure, but clinical studies looking at various predictors for failure, including graft size, have been inconclusive. Purpose: To evaluate the relationship of hamstring graft diameter to ACL revision within a large cohort of patients, while controlling for sex, age, body mass index (BMI), and femoral and tibial fixation type. Study Design: Case-control study; Level of evidence, 3. Methods: A case-control study using patients registered in an ACLR registry was conducted. Revision was used as a marker for graft failure. A case was defined as a patient who underwent primary ACLR with a hamstring autograft that was revised during the study period (April 2006 to September 2012). Three controls, defined as patients who underwent primary ACLR with a hamstring autograft that was not revised, were matched to each of the cases according to age, sex, BMI, and femoral and tibial fixation type. Descriptive characteristics were employed, and conditional logistic regression was conducted to produce estimates of odds ratios and 95% CIs. Results: A total of 124 cases and 367 controls were identified. There were no significant differences between cases and controls in the distribution of sex (52.4% male vs 52.9% male, respectively; P = .932), median age (17.6 years [interquartile range (IQR), 15.9-20.4] vs 17.6 years [IQR, 15.9-20.4], respectively; P = .999), median BMI (23.4 kg/m2 [IQR, 21.5-26.4] vs 23.4 kg/m2 [IQR, 21.6-25.8], respectively; P = .954), femoral fixation (P = .459), and tibial fixation (P = .766). The mean (±SD) graft diameter was 7.9 ± 0.75 mm in the cases and 8.1 ± 0.73 mm in the controls. The likelihood of a patient needing revision ACLR in the study cohort was 0.82 times lower (95% CI, 0.68-0.98) for every 0.5-mm increase in the graft diameter from 7.0 to 9.0 mm. Conclusion: In this study, within the range of 7.0 to 9.0 mm, there was a 0.82 times lower likelihood of being a revision case with every 0.5-mm incremental increase in graft diameter. [ABSTRACT FROM AUTHOR]

Background: The ability to accurately predict the diameter of autograft hamstring tendons has implications for graft choice and fixation devices used in anterior cruciate ligament (ACL) reconstruction. Purpose: To determine whether simple anthropometric measurements such as height, mass, body mass index (BMI), age, and gender can be used to accurately predict the diameter of hamstring tendons for ACL reconstruction surgery. Study Design: Cohort study (prevalence); Level of evidence, 2. Methods: The authors conducted medical record reviews and telephone interviews of 106 consecutive patients with AOL reconstruction using quadrupled semitendinosus-gracilis autograft from 2004 to 2006. Data included anthropometric measurements (height, mass, gender, and age at the time of surgery). Hamstring diameter was obtained using cylindrical sizers in 0.5-mm increments and recorded in the patient's surgical record. Correlation coefficients (Pearson r) and stepwise, multiple linear regression were used to determine the relationship between the outcome variable (hamstring graft diameter) and the predictor variables (age, gender, height, mass, and BMI). Independent sample t tests were used to compare hamstring graft diameter between genders. Results: Hamstring graft diameter was related to height (r = .36, P < .001), mass (r = .25, P = .005), age (r = -.16, P = .05), and gender (r = -.24, P = .006) but was not related to BMI (P > .05). Height was a statistically significant prediction variable (R² = .13, P < .001). From the current data, a regression equation was calculated that suggested that a patient <147 cm (58 in) tall is likely to have a quadrupled hamstring graft diameter <7 mm in diameter (graft size = 2.4 + 0.03 × height in cm). Women had significantly smaller hamstring graft diameters (7.5 ± 0.7 mm) than did men (7.9 ± 0.9 mm, P = .01). Conclusions: Of the parameters studied, height was the best predictor of hamstring tendon diameter, particularly in women. [ABSTRACT FROM AUTHOR]

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Secondary decompensation of corneal endothelium, including transplanted, is a frequent long-term complication of glaucoma drainage surgery. According to literature data, after implantation of a glaucoma drainage device into the anterior chamber, the speed of endothelial cells density (ECD) loss increases significantly., Purpose: To study the possibility of performing modified Descemet membrane endothelial keratoplasty (DMEK) with maximum graft diameter, and to assess its short-term effectiveness in the treatment of bullous keratopathy (BK) in the presence of a glaucoma drainage device in the anterior chamber., Material and Methods: Modified surgery 3 / 4 -DMEK was performed in 9 eyes of 7 patients with BK and Ahmed glaucoma drainage using graft of maximum diameter (11±1 mm). Average follow-up time was 15.3±2.5 months (12 to 18 months)., Results: No intraoperative or postoperative complications were observed. Mean ECD after 12 months amounted to 1664±346 cells/mm 2 , which corresponds to ECD reduction of 34±9.6% (24 to 49%) in comparison to preoperative values. Mean best corrected visual acuity 12 months after surgery increased from 0.04±0.03 (0.01 to 0.1) to 0.3±0.2 (0.04 to 0.7). The last follow-up examination revealed all corneas to have preserved transparency and stable pachymetry measurements (from 488 to 548 µm)., Conclusion: Performing 3 / 4 -DMEK with a mega graft for treatment of BK after drainage surgery is technically possible. Absence of Descemet membrane (DM) donor and preservation of DM recipient in the drainage tube plane eliminates its contact with the endothelium. Maximum graft diameter should in the long term help prolong the effectiveness of the surgery.

Abstract: The use of autologous grafts such as the quadrupled semitendinosus and gracilis tendon is very common in anterior cruciate ligament (ACL) reconstruction. The diameter of such grafts can be variable and thus unpredictable prior to surgery. In this study, we hypothesized that parameters such as gender, height, age, and body mass index (BMI) can be used pre-operatively to reveal the true graft diameter. All hamstring ACL reconstructions from 1994 to 2002 were reviewed. 536 cases (302 females, 234 males) met the inclusion criteria. Quadruple hamstring constructs and femoral tunnel diameters were measured using 1mm increment graft sizers. Pre-operative measures of height, weight, body mass index, gender, and age were obtained. Multiple regression analysis was used to build a predictive model of the quadruple hamstring graft diameter. The results of the study demonstrated that males had significantly larger grafts than females (8.1±0.8 vs. 7.5±0.6mm). Multiple regression analysis on the entire group showed that pre-operative height (p <0.0002) and gender (p <0.0047), but not age (p <0.06) or weight (p <0.019) were significant predictors of graft diameter. Height (p <0.0001) was a specific predictor solely in men. In females, none of the pre-operative measures were predictive of graft diameters. Patient height and gender can be used as pre-operative indicators of in vivo quadrupled hamstring graft diameter. Regardless of other variables, 42% of females will have tunnel diameters of 7mm or less. An alternative graft choice should be discussed pre-operatively if graft sizes may be of concern for the tall and large female patients. [Copyright &y& Elsevier]

Background: The removal of all adherent muscle tissue from the hamstring graft during anterior cruciate ligament reconstruction (ACLR) is common practice. However, there is a paucity of research to justify this removal or evaluate its biological implications., Purpose/hypothesis: The purpose of this study was to (1) evaluate the histological characteristics of the myotendinous muscle tissue harvested from hamstring tendons, (2) compare the final diameter of the prepared graft before and after the removal of the remnant musculature, and (3) evaluate patients who were treated with and without preservation of the graft-adhered muscle. The hypothesis was that the adherent musculature of the graft would have cells that could contribute to graft incorporation and revascularization, assist in the proprioceptive capacity of the neoligament, and increase the graft's diameter., Study Design: Cohort study; Level of evidence, 3., Methods: We divided 84 patients into 2 groups: group 1 underwent ACLR using hamstring tendon autograft with adherent musculature, and group 2 underwent ACLR using hamstring tendon autograft stripped of its remnant muscle. All patients had minimum 2-year follow-up. The muscle harvested from the graft in group 2 was submitted for histological examination, and the graft diameter before and after muscle removal was compared. The Tegner activity scale and Lysholm scores were determined preoperatively and at 12 and 24 months postoperatively., Results: There was a significant difference in graft diameter between groups. The evaluation of the graft diameter in group 2 showed a decrease of 11.52% after removal of muscle tissue from the tendon graft. Patients from group 1 had better Tegner and Lysholm scores (mean ± SD) after 12 months (Tegner, 8.03 vs 7 [ P = .004]; Lysholm, 95.48 ± 1.2 vs 87.54 ± 3.21 [ P = .002]) and better Lysholm scores after 24 months (95.76 ± 2.1 vs 89.32 ± 2.47; P = .002). The muscle tissue of the analyzed fragments presented a pattern with fibrous tissue beams, invaginating regularly and sequentially from the myotendinous junction into the muscles., Conclusion: Preserving the muscle tissue on tendon grafts promoted a volumetric increase in the final autograft diameter and demonstrated biological and regenerative potential. Patients who underwent ACLR using the tendon with the muscle attached had better functional scores at 2-year follow-up as compared with patients treated using the tendon with the muscle removed., Competing Interests: The authors have declared that there are no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2021.)

The clinical implications of changing the shape of the bone tunnel for Anterior cruciate ligament reconstruction (ACLR) is controversial and few studies have reported on the long-term prevalence for osteoarthritis. As such, this study aims to evaluate the effect of tunnel shape on joint biomechanics. Finite element models of an ACLR were constructed with different shapes (circular, oval, rounded rectangular, rectangular, and gourd-shaped) and diameters (7.5, 8.5, and 9.5 mm) for the bone tunnel. A combined loading of 103 N anterior tibial load, 7.5 Nm internal tibial moment and 6.9 Nm valgus tibial moment was applied at a joint flexion angle of 20°. Joint kinematics and the strain energy density (SED) on the articular cartilage were compared among the different groups. The results showed that conventional ACLR (circular tunnel) lead to an increase in joint kinematics over the intact joint, a lower ligament force and a higher SED on the lateral tibial cartilage. ACLR using the other tunnel shapes resulted in even greater joint kinematics, lower graft force and greater SED on the lateral tibial cartilage. Increasing the tunnel diameter better restored joint kinematics, graft force and articular SED, bringing these values closer to those from the intact knee. In conclusion, increasing the tunnel diameter may be more effective than changing the tunnel shape for restoring joint functionality after ACLR., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Wang, Zhang and Cheng.)

The degree and significance of postoperative alteration in the size of Dacron grafts in the infrarenal abdominal aorta was assessed by computed tomography. We studied a total of 41 knitted Dacron fabric grafts, comprising 28 Gelseal triaxial grafts and 13 Hemashield Microvel grafts, and 29 woven Dacron fabric (Veri-Soft Woven) grafts which were used to replace the infrarenal abdominal aneurysms. These three types of Dacron fabric dilated immediately after replacement to 1.4-1.5 times the manufactured size, but did not dilate further after the surgery. [ABSTRACT FROM AUTHOR]

Background: Anterior Cruciate Ligament (ACL) is the most common ligament injury during sports activities that was treated with ACL reconstruction. Nowadays, peroneus longus is used in ACL reconstruction. However, it is difficult to predict the peroneus longus graft diameter for ACL reconstruction. Thus, preoperative measurements are very important to predict peroneus longus autograft for ACL reconstruction., Methods: A cohort retrospective study was conducted using consecutive sampling method from February 2016 until October 2017 in our center. We recorded patients' characteristics include gender, age, body weight, height, and Body Mass Index (BMI) preoperatively. We measured peroneus longus graft diameter intraoperatively, and analysed data using Spearman correlation., Results: Thirty-nine patients met inclusion criteria. There were 28 males and 11 females in the peroneus group. From the patients' mean characteristics, age was 25.10 ± 9.16, body weight 71.23 ± 14.17, height 169.13 ± 8.81, and BMI 20.96 ± 3.44. Intraoperative peroneus longus diameter measurement was 8.56 ± 0.82. Spearman correlation showed significant correlation between intraoperative peroneus longus diameter with patient's height, body weight, and BMI with p  < 0.05., Conclusion: Patients' characteristics including gender, height, weight, and BMI in preoperative measurements can predict peoneus longus graft diameter intraoperatively., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (© 2019 The Author(s).)

Background: Recent studies have described surgical techniques to increase the hamstring graft diameter for anterior cruciate ligament reconstruction (ACLR), particularly for 5-strand hamstring (5HS) autografts., Purpose: To review the literature examining the biomechanical and clinical outcomes of 5HS autografts for ACLR., Study Design: Systematic review; Level of evidence, 3., Methods: A systematic review using PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines was performed by searching PubMed, Embase, and the Cochrane Library for studies reporting the biomechanical and clinical outcomes of 5HS autografts. All English-language literature published from 2012 to 2018 that reported the biomechanical properties of 5HS grafts and/or clinical outcomes after ACLR with 5HS autografts with a minimum 1-year follow-up was reviewed by 2 independent reviewers. Graft diameter, stiffness, displacement, strength, failure rates, anteroposterior knee laxity, and patient-reported outcome scores were collected. The study methodology was evaluated using the modified Coleman Methodology Score., Results: Two biomechanical and 3 clinical studies (1 with level 2 evidence, 2 with level 3 evidence) were included. The biomechanical studies compared the results of fourteen 4-strand hamstring (4HS) and fourteen 5HS graft specimens for ACLR (ovine grafts, n = 12; cadaveric grafts, n = 16) and found no significant differences in ultimate load, stiffness, displacement, and stress relaxation ( P > .05), likely attributed to insufficient incorporation of the fifth strand. The mean 5HS cadaveric graft diameter (8.2 mm) was significantly greater than that of 4HS grafts (6.8 mm) ( P = .002), whereas the mean ovine graft diameters were not significantly different (4HS, 5.2 mm; 5HS, 5.3 mm) ( P > .05). Two clinical studies compared the outcomes after ACLR of 53 patients with a 4HS autograft versus 62 patients with a 5HS autograft, while 1 clinical study reported the outcomes of 25 patients after ACLR with a 5HS autograft (mean age, 28.7 years; mean follow-up, 24.8 months). The overall mean diameter for 4HS and 5HS autografts was 8.4 and 9.1 mm, respectively. There was no significant difference in failure rates between 4HS and 5HS autografts ( P = .82). None of the comparative studies reported significant differences in any clinical outcomes ( P > .05 for all)., Conclusion: The available literature on traditional 4HS and 5HS autografts for ACLR is limited. Of the available data, clinical and biomechanical studies suggest no difference in outcomes after ACLR with either graft construct. Additional research is needed to determine whether creating a 5HS graft is beneficial., Competing Interests: One or more of the authors has declared the following potential conflicts of interest or source of funding: A.F.V. is a consultant for ArthroCare and Stryker, is a paid speaker/presenter for Arthrex and Ceterix, has received educational support from Smith & Nephew, and has received hospitality payments from Steris. R.M.F. has received educational support from Arthrex, Medwest, and Smith & Nephew and hospitality payments from Stryker. J.T.B. is a consultant for DJ Orthopedics, Encore Medical, Smith & Nephew, and Stryker; has received research support from Stryker; has received fellowship funding from Mitek; and receives royalties from Shukla Medical. E.C.M. is a consultant for Biomet and DePuy; has received research support from Biomet, Mitek, Smith & Nephew, and Stryker; and receives royalties from Biomet and Elsevier. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.