Are pre-operative anthropometric parameters helpful in predicting length and thickness of quadrupled hamstring graft for ACL reconstruction in adults? A prospective study and literature review

Tendon cross-sectional area on magnetic resonance imaging and anthropometric characteristics can be used to predict insufficient four-strand hamstring autograft diameter in anterior cruciate ligament reconstruction: A systematic review

PURPOSE

To evaluate the utility of semitendinosus tendon (ST) and gracilis tendon (GT) cross-sectional area (CSA) on magnetic resonance imaging (MRI) and anthropometric characteristics in preoperative estimation of graft diameter in patients undergoing anterior cruciate ligament reconstruction (ACLR) with four-strand hamstring autografts.

METHODS

Three databases were searched on 29 August 2023. The authors adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and R-AMSTAR (Revised Assessment of Multiple Systematic Review) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, anthropometric characteristics, imaging techniques, tendon CSA, correlation coefficients, sensitivities, specificities, regression models and cutoffs for predicting intraoperative graft diameters above 8 mm were recorded.

RESULTS

Forty-six studies comprising 4140 patients were included. Twelve of 19 (63.2%) studies reporting on ST + GT CSA found a moderate to very high correlation with intraoperative graft diameter. Five of 10 (50%) and one of seven (14.3%) studies reporting on ST CSA and GT CSA, respectively, found a moderate to high correlation with intraoperative graft diameter. Cutoffs of ST + GT CSA for predicting graft diameters above 8 mm ranged from 15.8 to 31.2 mm2. Nine of 35 (25.7%) studies that reported on height found a moderate to very high correlation with graft diameter. Seven of 33 (21.2%) studies reporting on weight found a moderate correlation with graft diameter.

CONCLUSION

Of the MRI parameters assessed, ST + GT CSA was the most reliable predictor of graft diameter. However, cutoffs, sensitivities, and specificities for predicting diameters above 8 mm were highly variable. Anthropometric characteristics in general were less predictive of graft diameter than MRI parameters. This information can be used by clinicians to predict patients at risk for ACLR failure due to insufficient graft size.

LEVEL OF EVIDENCE

Level IV.

A novel practical method to predict anterior cruciate ligament hamstring graft size using preoperative MRI

BACKGROUND

Predicting hamstring graft size preoperatively for anterior cruciate ligament (ACL) reconstruction is important for preempting an insufficient diameter in graft size intraoperatively, possibly leading to graft failure. While there are multiple published methods using magnetic resonance imaging (MRI) picture archiving and communication systems (PACS), most are not feasible and practical. Our study aims to (1) practically predict the ACL hamstring graft size in a numerically continuous manner using the preoperative MRI from any native MRI PACS system, (2) determine the degree of correlation between the predicted and actual graft size, and (3) determine the performance of our prediction method if we define an adequate actual graft size as ≥ 8 mm.

METHODS

A retrospective review of 112 patients who underwent primary ACL reconstruction with quadrupled hamstring semitendinosus-gracilis grafts at a tertiary institution was conducted between January 2018 and December 2018. Graft diameter can be predicted in a numerically continuous manner as √[2*(AB + CD)], where A and B are the semitendinosus cross-sectional length and breath, respectively, and C and D are the gracilis cross-sectional length and breath, respectively.

RESULTS

A moderately positive correlation exists between the predicted and actual graft diameter (r = 0.661 and p < .001). Our method yields a high specificity of 92.6% and a moderate sensitivity of 67.2% if we define an adequate actual graft size as ≥ 8 mm. An area under receiver-operating characteristic curve shows good discrimination (AUC = 0.856).

CONCLUSIONS

We present a practical method to predict the ACL hamstring graft size with high specificity using preoperative MRI measurements.

Estimation Failure Risk by 0.5-mm Differences in Autologous Hamstring Graft Diameter in Anterior Cruciate Ligament Reconstruction: A Meta-analysis

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.

Correlation between anthropometric measurements and graft size in anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to investigate the correlation between anthropometric measurements and graft size in anterior cruciate ligament (ACL) reconstruction.

METHODS

A systematic search of Ovid MEDLINE, Embase, and Cochrane Library databases was conducted for observational studies published until March 2023 that reported the relationship between anthropometric data [height, weight, body mass index (BMI), age, gender, thigh length, and circumference] and ACL graft size. Correlation coefficients (COR) and their associated 95% confidence intervals were used as the primary effect size. This review was conducted in line with PRISMA guidelines.

RESULTS

A total of 42 observational studies involving 7110 patients were included, with a mean age of 29.8 years. Statistically significant, moderately positive correlations were found between graft size and height (COR: 0.49; 95% CI: 0.41-0.57; p-value: < 0.001), weight (COR: 0.38; 95% CI: 0.31-0.44; p-value: < 0.001), thigh circumference (COR: 0.40; 95% CI: 0.19-0.58; p-value: < 0.001), and thigh length (COR: 0.35; 95% CI: 0.18-0.50; p-value: < 0.001). However, age and gender were insignificantly correlated with graft size (p-value: NS). A subanalysis based on graft type showed a significant positive correlation between height and graft diameter, which was more significant in the peroneus tendon than in hamstring grafts (COR: 0.76 vs. 0.45; p-value: 0.020).

CONCLUSION

This study demonstrated a moderate positive correlation between anthropometric measurements (height, weight, thigh circumference, and length) and ACL graft size, along with a weak positive correlation with BMI. Age and gender showed no significant correlation. These findings support the predictability and selection of ACL graft size based on pre-operative patient anthropometric data.

LEVEL OF EVIDENCE

Level of Evidence: IV. PROSPERO registration number: CRD42023416044.

Estimated diameter increase from a 4S to a 6S hamstring graft configuration - A cadaveric study

PURPOSE

Graft diameter in anterior cruciate ligament reconstructions has been shown to influence the risk of failure. It is therefore important to be able to adjust the graft configuration to modify the diameter. To measure the impact of a 6-strand (6S) hamstring autograft configuration on graft diameter compared to the standard 4-strand (4S) configuration.

METHODS

Cadaveric study on 33 knees, using the usual hamstring graft harvesting technique. Semitendinosus and gracilis tendons were harvested and their length, width, and diameter were measured in 4S and 6S configurations separately by three evaluators.

RESULTS

6S configuration leads to a median increase of 1.5 (range: 0.0-2.0) mm in diameter compared to 4S (p < 0.001). A graft diameter of more than 8 mm is attained in less than a third of 4S grafts within this population in comparison to 84% when the 6S configuration is used.

DISCUSSION

The 6S hamstring graft configuration increases the graft diameter by a median of 1.5 millimeters compared to the traditional 4S configuration. It can reliably be used to obtain an 8.5 mm graft diameter or more in cases where the semitendinosus measures at least 270.5 mm and the 4S configuration has a diameter of 7.5 mm or 8 mm. This information helps to better delineate the impact of a 6S configuration in a pre-operative or intra-operative setting to optimize the decisional process and surgical flow and to easily adapt the graft diameter.

LEVEL OF EVIDENCE

V (cadaveric study).

A Web-Based Prediction Tool to Improve Identification of Patients With Undersized Hamstring Tendon Autograft in Anterior Cruciate Ligament Reconstruction

BACKGROUND

An undersized hamstring tendon (HT) autograft is significantly associated with a higher graft failure rate in anterior cruciate ligament reconstruction (ACLR) surgery. The ability to accurately predict inadequate HT graft diameter is critical, as it could assist surgeons in making better graft choices and surgical plans.

PURPOSE

To develop a web-based prediction tool to better assess the size of HT autograft and to help clinicians accurately identify patients with potentially undersized HT grafts in order to make appropriate clinical decisions.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 588 patients who received primary arthroscopic single-bundle ACLR surgery with gracilis tendon (GT) and semitendinosus tendon (ST) autograft were retrospectively reviewed. According to the size of 4-strand HT graft, patients were divided into diameter ≥8 mm and <8 mm groups. The least absolute shrinkage and selection operator method and logistic regression were used to identify the independent factors associated with HT graft diameter and establish the models. The prediction performance of the model was evaluated by concordance index and calibration combined with external validation. The diagnostic performance of the prediction model was assessed by sensitivity, specificity, predictive values, and likelihood ratios. Decision curve analysis was used to evaluate the clinical utility of the model.

RESULTS

Among the numerous indicators, sex, weight, height, thigh length, and ST-GT diameter (measured on plane 1 of a magnetic resonance imaging scan) were identified to be highly correlated predictors that could provide satisfactory prediction performance in determining the HT graft diameter. Based on these predictors, a prediction model named the HTD model was developed with satisfactory discrimination (concordance index, 0.932) and calibration (mean absolute error, 0.039). When the probability calculated by the HTD model was >65%, the sensitivity and specificity of predicting 4-strand HT graft diameter ≥8 mm were 86.7% and 90.2%, respectively.

CONCLUSION

As a useful supplementary prediction tool, the HTD model could accurately predict the diameter of HT autograft during preoperative planning.

Anthropometry in predicting Semitendinosus and Gracilis graft diameter for arthroscopic ACL reconstruction among the Bengali population

Semitendinosus and Gracilis autografts are commonly used for anterior cruciate ligament (ACL) reconstruction. However, its main drawback is individual variation in the tendon diameter. This study aimed to evaluate the usefulness of the anthropometric measurements for the prediction of Semitendinosus and Gracilis combined (quadrupled) strands graft diameter in arthroscopic ACL reconstruction among the Bengali population. Sixty consecutive patients who underwent ACL reconstruction between July 2019 to June 2020 were observed in this cross-sectional study. In all cases, the doubled (2 strands) Gracilis and Semitendinosus tendons were combined to get the final quadrupled (combined 4 strands) graft for use. Anthropometries such as body mass index (BMI), body weight, and height were recorded preoperatively and quadrupled combined tendon diameter was measured at the operating theater. The relationship between these parameters was statistically determined using the Pearson correlation coefficient, and scatter diagrams were plotted. Among the study subjects, most (54) were male, and the mean age of all subjects was 24 ± 6.92 years. The average graft diameter was 7.20 ± 0.76 mm. Correlations between the mean graft diameter with BMI (r = 0.018, and P = .891), body height (r = 0.011 and P = .933), and weight (r = 0.028 and P = .832) were not significant. Scatter diagrams also showed that the variables were not correlated. Anthropometries like BMI, body weight, or body height cannot be used in predicting Semitendinosus and Gracilis tendon graft diameter for arthroscopic ACL reconstruction among the Bengali population.

A fast, easy and reliable method for hamstrings graft size prediction in anterior cruciate ligament reconstruction

PURPOSE

The aim of this study is to describe and validate a simple and reliable method to pre-operatively predict the size of the ACL graft in the double strand technique with autologous semitendinosus-gracilis tendons on the same MRI used for ACL rupture diagnosis.

METHODS

The study included 92 patients, with a median age of 31 years (IQR 26-41 years), 73/92 (79%) of whom were males. All patients that underwent an ACL reconstruction with doubled ST + GT between 2017 and 2022 were counted in the study.

RESULTS

Overall, the median predicted graft diameter from MR imaging was similar to the actual graft diameter with no significant differences (n.s.). Regarding the comparison between predicted and actual graft size, concordance was 78/92 (85%, 95% CI 76-91%), with κ = 0.797 which corresponds to a level of agreement defined as "Strong". Tendon sizes calculated on pre-operative MRI were evaluated both with intra-observer and inter-observer reliability demonstrating a statistically reproducible method. The predicted graft was then compared to the reported one with a statistically significant reliability found.

CONCLUSION

This study can help the surgeons to perform a fast pre-operative planning of an ACL reconstruction for graft selection. If the planned graft with ST and GT is smaller than 8 mm, the clinician can decide to switch to a different type of graft or plan a different graft preparing technique and, therefore, reduce the risk of post-operative ligament re-rupture. The method proposed is reliable and reproducible. The major strength of the planning technique proposed is that it relies on data that are already available for the clinician before surgery, without the need of further analysis.

LEVEL OF EVIDENCE

IV.

Correlation of anthropometric parameters with semitendinosus tendon length in anterior cruciate ligament injured patients

Anterior cruciate ligament reconstruction (ACLR) surgery is now a common procedure performed following a tear of the anterior cruciate ligament. The length of the harvested hamstring tendon is critical to the outcome of the surgery as it may influence the final length and thickness of the graft. The goal of this study was to attempt to establish a relation- ship between the height, weight and body mass index and the harvested length of the semitendinosus tendon of patients having ACLR surgery. This was a retrospective study. The weight, height, and body mass index (BMI) of patients for primary anterior cruciate ligament reconstruction were noted. The average length of the tendon was noted. The correla- tion between each of these anthropometric parameters and the tendon length was estimated. The range of values for the semitendinosus length, height and weight in males and females respectively were 24-39cm (31.26 +/- 2.93) and 26-35cm (29.26 +/- 2.08); 1.6-1.96 m and 1.65-1.8m; and 52-110kg and 60-106kg. Only the height revealed a moderate correlation with the length of the harvested tendon among the male patients. Linear regression analyses yielded the equation Sem- itendinosus tendon length = 23.25xheight-10.28 at a p-value of 0.002. Patient height could be predictive of the length of the harvested semitendinosus tendon.

Anthropometric Measurements of Hamstring Tendon Graft and Its Predictors in Ligament Reconstruction Surgeries of Knee: An Observational Study

Introduction Hamstring graft use has been in the forefront of ligament reconstruction around the knee. With the increasing number of surgeries, the complications are equally on the rise. One of the detrimental factors for predicting the outcome is the diameter and length of the graft. We did an observational study to find out the relationship of patient factors with the morphometry of the graft.

Materials and Methods Total 484 patients were included in the study. Preoperatively, the age, sex, height, weight, and activity levels of the patients were noted. They were categorized into two major groups: physically active and inactive. The intraoperative measurements of the grafts were recorded. Analysis of variance for comparing the means of multiple groups was used for statistical analysis.

Results Among the total 484 patients, 407 were male and 77 were female. The semitendinosus graft diameter did not show any statistical significance to the age and weight of the patient. The mean graft diameter was highest in the 45 to 49-year age group. The average graft diameter in physically active group was 3.704 mm, and 3.503 mm in the inactive group. This and the height of the patient proved to have statistically significant relation with graft diameter.

Conclusion Physical activity along with the height of the patient must be taken into due consideration before embarking upon ligament reconstruction with hamstring graft in mind, as these two are found to determine the diameter and length of the hamstring graft.

No Difference Could Be Detected in Clinical Outcomes of 5-Strand and Quadruple Hamstring Autografts of Similar Diameter in Anterior Cruciate Ligament Reconstruction: A Retrospective Cohort Study

Background: There are few studies examining the clinical outcomes of 5-strand autografts in anterior cruciate ligament reconstruction (ACL-R). Purpose: We aimed to compare the clinical outcomes of ACL-R using 5-strand (5HS) and 4-strand (4HS) hamstring autografts of similar graft diameter to study the potential effects of autograft strand number on clinical outcomes. Methods: Patients who underwent ACL-R from 2013 to 2018 at a single academic institution and received a 4HS or 5HS autograft were included. Exclusion criteria were less than 2-year follow-up and any additional ligamentous reconstruction. Revision ACL-R and cyclops lesions were assessed at a minimum 2 years of postoperative follow-up. Objective measures of ability to return to sport were assessed at 6 months. Results: The mean graft diameters for 4HS (n = 51) and 5HS (n = 23) autografts were 8.3 ± 0.7 mm and 8.4 ± 0.7 mm, respectively. The mean follow-up for the 4HS and 5HS cohorts was 3.0 ± 1.5 years and 3.3 ± 1.3 years, respectively. The 4HS and 5HS cohorts had revision ACL-R rates of 15.7% (8/51) and 8.7% (2/23), respectively. Cyclops lesions occurred in 5.9% of 4HS patients and 13.0% of 5HS patients. We found no statistically significant differences between groups on objective measures of ability to return to sport. Conclusion: This retrospective cohort study detected no difference in revision ACL-R rates, frequency of cyclops lesions, or objective measures of ability to return to sport in patients who received 4HS or 5HS autografts of similar diameter for ACL-R. Further comparative study with larger sample sizes is warranted.

Prediction of hamstring tendon autograft diameter using preoperative measurements with different cut-offs between genders

PURPOSE

Studies have suggested some predictors for hamstring tendon (HT) autograft diameter based on anthropometric factors and preoperative magnetic resonance imaging (MRI) with variable results. Some authors have attributed the variability to gender differences. This prospective cohort reports the sensitivity and specificity of anthropometric and MRI predictors in males and females separately to determine the difference.

METHODS

Forty-two eligible patients who underwent anterior cruciate ligament reconstruction (ACLR) and MRI in our center were included. ACLR was performed by the senior surgeon using a 4-stranded HT autograft for all patients. A blinded musculoskeletal radiologist measured the cross-sectional area (CSA) of gracilis and semitendinosus tendons using the free-hand region of interest tool for all patients. An orthopaedic resident (PGY4) collected anthropometric factors and measured intraoperative autograft diameter.

RESULTS

Mean intraoperative autograft diameter was 8.0 mm. Females had a significantly lower autograft diameter (7.4 vs. 8.2, P < 0.001), smaller gracilis (6.9 vs. 7.9, P = 0.003) and semitendinosus CSA (11.5 vs. 12.8, P = 0.014) compared to males. ROC curve analysis resulted different cut-off values with high sensitivity and specificity for semitendinosus and combined CSA regarding gender.

CONCLUSION

Based on the results of this study, CSA of either isolated or combined HTs on preoperative axial MRI, height, and weight are the strongest predictors of intraoperative autograft diameter. It is suggested to consider different cut-offs for males and females to have a better clinical guide for surgeons.

LEVEL OF EVIDENCE

Level II.

Prediction of individual graft for anterior cruciate ligament reconstruction using anthropometric data

INTRODUCTION

Multiple options for individual anterior cruciate ligament (ACL) reconstruction exist; still, there are no guidelines for the preoperative preparation. The aim of this study was to assess the correlation between patients' anthropometric data (height, weight, and age) and measurements of potential tendons (quadriceps-, patella, hamstrings tendon) for an anterior cruciate ligament reconstruction.

MATERIAL AND METHODS

MR images of 102 patients have been analyzed. Measurements of the ACL were performed with respect to its length and angle. The diameter and length as well as width of the quadriceps and patella tendon, the cross-sectional area (CSA) and diameter of the hamstring tendons have been assessed. Patients' height, weight, BMI, sex and age have been recorded. The correlations of these measurements with the patients' anthropometric data have been calculated. Inter-rater and intra-rater reliability based on intra-class correlation (ICC) was evaluated.

RESULTS

The mean lengths of the ACL were 29.8 ± 3.5 mm, tibial insertion sites 15.8 ± 2.5 mm and femoral insertion sites 15.2 ± 3.0 mm. Thickness of the quadriceps tendons was 4.7 ± 1.1 mm and patella tendon 3.2 ± 0.7 mm. The patients' height showed significant positive correlations with the CSA of the hamstring tendon measurements, the length of the ACL, and the insertion sites of the ACL. Patients' weight showed significant positive correlations with patella tendon thickness, the CSA of the hamstring tendons, the length of the ACL, and the tibial and femoral insertion sites. Patients' age showed a significant positive correlation with patella tendon thickness. The ICCs for intra- and inter-rater reliability were 0.98 (95% CI 0.95-0.99, p < 0.001) and 0.94 (95% CI 0.88-0.99, p < 0.001).

CONCLUSION

Anthropometric data with respect to height, weight, and sex can help to predict the dimension of tendons for ACL reconstruction and do correlate with ACL tendon. Patients at risk for small graft dimensions and failure are younger than 20 years and physically active. MRIs of patients at risk for small graft dimensions should be analyzed on tendon length and cross section areas preoperatively to determine the appropriate tendon harvest and fixation technique.

Performance of 5-Strand Hamstring Autograft Anterior Cruciate Ligament Reconstruction in the STABILITY Study: A Subgroup Analysis

BACKGROUND

Anterior cruciate ligament (ACL) reconstructions (ACLRs) with graft diameters <8mm have been shown to have higher revision rates. The 5-strand (5S) hamstring autograft configuration is a proposed option to increase graft diameter.

PURPOSE

To investigate the differences in clinical outcomes between 4-strand (4S) and 5S hamstring autografts for ACLR in patients who underwent ACLR alone or concomitantly with a lateral extra-articular tenodesis (LET) procedure.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Data from the STABILITY study were analyzed to compare a subgroup of patients undergoing ACLR alone or with a concomitant LET procedure (ACLR + LET) with a minimum graft diameter of 8mm that had either a 4S or 5S hamstring autograft configuration. The primary outcome was clinical failure, a composite of rotatory laxity and/or graft failure. The secondary outcome measures consisted of 2 patient-reported outcome scores (PROs)-namely, the ACL Quality of Life Questionnaire (ACL-QoL) and the International Knee Documentation Committee (IKDC) score at 24 months postoperatively.

RESULTS

Of the 618 patients randomized in the STABILITY study, 399 (228 male; 57%) fit the inclusion criteria for this study. Of these, 191 and 208 patients underwent 4S and 5S configurations of hamstring ACLR, respectively, with a minimum graft diameter of 8mm. Both groups had similar characteristics other than differences in anthropometric factors-namely, sex, height, and weight, and Beighton scores. The primary outcomes revealed no difference between the 2 groups in rotatory stability (odds ratio [OR], 1.19; 95% CI, 0.77-1.84; P = .42) or graft failure (OR, 1.13; 95% CI, 0.51-2.50; P = .76). There was no significant difference between the groups in Lachman (P = .46) and pivot-shift (P = .53) test results at 24 months postoperatively. The secondary outcomes revealed no differences in the ACL-QoL (P = .67) and IKDC (P = .83) scores between the 2 subgroups.

CONCLUSION

At the 24-month follow-up, there were no significant differences in clinical failure rates and PROs in an analysis of patients with 4S and 5S hamstring autografts of ≥8mm diameter for ACLR or ACLR + LET. The 5S hamstring graft configuration is a viable option to produce larger-diameter ACL grafts.

Transepicondylar distance measured on MRI can predict the length of the graft required for different anterior cruciate ligament reconstruction (ACLR) techniques useful for revision surgery

Background

The aim of this study is to find a correlation between linear measurements and the graft length required for different anterior cruciate ligament (ACL) revision techniques, to extract formulas to predict required graft length during the preoperative planning.

Methods

At time 0 and 30 days later, two observers measured eight linear distances on standard 2D knee magnetic resonance imaging (MRI), and nine curved distances on 3D MRI sequences, corresponding to different techniques for ACL revision, anatomic anterolateral ligament (ALL) reconstruction, and lateral extrarticular tenodesis (LET). Intra- and interobserver reliability was tested for 2D and 3D measurements. The correlation between 2D and 3D measurements was tested. The 2D measurements with highest repeatability and reproducibility, and with strongest correlation with 3D measurements were used to extract formulas to calculate the graft length from 2D values.

Results

Fifty MRIs acquired with both 2D and 3D sequences were used. The intra- and interobserver reliability of linear 2D measurement was high, with the transepicondylar distance (TD) showing the highest reproducibility and repeatability. The intra- and interobserver reliability of 3D measurements was lower than 2D, but acceptable for all measurements except for ALL reconstruction. The TD showed the strongest correlation with 3D measurements. The formulas extracted to calculate the graft length from the TD proved to be accurate.

Conclusion

Accurate formulas were created to calculate the graft length needed for different ACL revision techniques and ALL reconstruction/LET techniques from TD. These formulas can be used during preoperative planning of ACL revision cases.

Combined Assessments of Patellar Tendon and Hamstring Tendon Parameters on Preoperative Magnetic Resonance Imaging Can Improve Predictability of Hamstring Tendon Autograft Diameter in the Setting of Anterior Cruciate Ligament Reconstruction

Purpose

To evaluate whether preoperative magnetic resonance imaging (MRI) measurements of multiple tendon autograft sources could be used to improve estimates of intraoperative hamstring tendon autograft (HTA) diameter.

Methods

Patients who underwent anterior cruciate ligament reconstruction with HTA at our institution were identified through electronic health records. Preoperative MRI tendon measurements of the patellar tendon (PT) length, PT width, PT thickness, quadriceps tendon thickness, semitendinosus tendon (ST) cross-sectional area (CSA), and gracilis tendon (GT) CSA were conducted by 2 independent evaluators using digital imaging measurement tools.

Results

A total of 53 patients met the inclusion criteria, with a mean HTA diameter of 7.98 ± 0.7 mm. Height greater than 1.63 m, weight greater than 63.4 kg, PT length greater than 4.2 cm, PT thickness greater than 0.33 cm, ST CSA greater than 10.8 mm², and GT CSA greater than 6.3 mm² were associated with an HTA of 8 mm or greater (P < .005). Female sex was associated with an HTA of less than 8 mm (P < .05). PT length, PT thickness, and GT CSA were the strongest predictors of an HTA of 8 mm or greater and were combined into an additive logistic regression model: Score = -23.24 + (1.68 × PT length) + (20.104 × PT thickness) + (1.48 × GT CSA). If the score was greater than 0.237, the HTA graft diameter was predicted to be 8 mm or greater with 83% specificity, 91% sensitivity, and 87% accuracy.

Conclusions

By combining PT length and PT thickness measurements with GT CSA measurements in a logit function model, we were able to show improved overall specificity, sensitivity, and accuracy of estimated HTA diameters in our data set when compared with assessments of anthropometric, ST CSA, GT CSA, or combined ST-GT CSA measurements in isolation.

Clinical Relevance

Preoperative MRI measurements may be used to screen whether a patient is likely to have an 8-mm graft in the setting of anterior cruciate ligament reconstruction with HTA and thus may help guide graft choice.

Correlation between height and semitendinosus tendon length, prediction of minimum semitendinosus tendon length based on height-an easy and accurate method

PURPOSE

To find out an easy method to predict tendon length on the basis of patient height.

METHODS

A prospective study which included 256 patients. All patients underwent ligament reconstruction using semitendinosus graft. Pre-operatively age, gender, height and weight were noted. Harvested semitendinosus graft's length and diameter was measured.

RESULTS

Both the patient height as well as weight correlated with tendon diameter and tendon length (p-value < 0.05). A simple equation was also derived to pre-operatively predict tendon length.

CONCLUSION

To predict graft size, surgeon should consider anthropometric variables. If we divide height of the patient with six, we get the approximate length of the tendon and by subtracting three from the obtained value we are more than 90% sure that ST would not be shorter than this.

LEVEL OF EVIDENCE

level 4.

Central femoral tunnel placement can reduce stress and strain around bone tunnels and graft more than anteromedial femoral tunnel in anterior cruciate ligament reconstruction

The present study investigated the effects of anteromedial (AM) and central femoral footprint placement on stress and strain distribution around the femoral and tibial tunnel and graft following anterior cruciate ligament reconstruction (ACLR). A three-dimensional (3D) reconstructed knee model was validated and used for simulating ACLR by finite element analysis. A combined loading during normal human walking was applied to the knee models using different anatomic femoral tunnel placement at 20° knee flexion. The results of von Mises stress and principal strain at the entrances of the femoral and tibial tunnel and ACL graft was determined. The peak von Mises stress and the maximum principal strain in the AM footprint group were 8.78 MPa and 8850.89 μ-strain at the entrance of femoral tunnel, and 5.29 MPa and 5553.27 μ-strain at the entrance of tibial tunnel. The results in the AM footprint group were higher than that in the central footprint group. The peak von Mises stress around the ACL graft following AM footprint ACLR was 28.63 MPa, higher than that following the central footprint ACLR. The AM footprint ACLR generated more significant peak von Mises stress and maximum principal strain around the entrances of femoral and tibial tunnel and the graft than the central footprint. The present results are of clinical relevance as they can provide a better understanding of tunnel enlargement and graft failure.

Predicting Quadruple Semitendinosus Graft Size for Anterior Cruciate Ligament Reconstruction by Patient Anthropometric Variables: A Cohort Study of 280 Cases

Introduction:

Pre-operative identification of patients with inadequate hamstring graft for anterior cruciate ligament reconstruction is still a subject of interest. The purpose of this study is to correlate dimension of a harvested dimensions graft with patient physical anthropometric variables.

Materials and methods:

This cohort study included 280 patients (male = 226, female = 54) scheduled for primary anterior cruciate ligament (ACL) reconstruction. Interrelationships between quadruple semitendinosus (ST) graft and anthropometric parameters (age, sex, height, weight, and BMI) were assessed using Pearson Correlation test and regression analysis. Difference among gender was analysed using Mann Whitney and t test. The observed graft diameter was also compared with the literature using Bland – Altman plot.

Results:

Mean age of cohort was 29 years (range, 17-50 years), mean height was 1.69m (range, 1.6-1.9m), mean weight was 75 kg (range, 50-116kg) and mean BMI was 26kg/m2 (range 16.65-40.40kg/m2). Mean quadruple length of harvested ST graft was 7cm (7.1±0.6 cm, range, 5.6-8.8cm) and mean diameter was 8mm (8.2±0.8mm, range, 6.5-10mm). Only height and weight were significantly correlated with graft length and diameter in both sex (p value <0.05). Female, compared to male, had significantly smaller (p<0.0001) and thinner graft (p<0.0001). There was a strong agreement between the literature and our observed graft diameter, but with an overestimated graft diameter in 18.5% of the cases.

Conclusion:

Among anthropometric parameter, only height and weight had moderate positive correlation with graft diameter. Males had longer and wider ST graft in contrast to age-matched female group.

The Femoral Tunnel Drilling Angle at 45° Coronal and 45° Sagittal Provided the Lowest Peak Stress and Strain on the Bone Tunnels and Anterior Cruciate Ligament Graft

Purpose: The aims of this study were to 1) investigate the effects of femoral drilling angle in coronal and sagittal planes on the stress and strain distribution around the femoral and tibial tunnel entrance and the stress distribution on the graft, following anterior cruciate ligament reconstruction (ACLR), 2) identify the optimal femoral drilling angle to reduce the risk of the tunnel enlargement and graft failure.

Methods: A validated three-dimensional (3D) finite element model of a healthy right cadaveric knee was used to simulate an anatomic ACLR with the anteromedial (AM) portal technique. Combined loading of 103.0 N anterior tibial load, 7.5 Nm internal rotation moment, and 6.9 Nm valgus moment during normal human walking at joint flexion of 20° was applied to the ACLR knee models using different tunnel angles (30°/45°/60° and 45°/60° in the coronal and sagittal planes, respectively). The distribution of von Mises stress and strain around the tunnel entrances and the graft was calculated and compared among the different finite element ACLR models with varying femoral drilling angles.

Results: With an increasing coronal obliquity drilling angle (30° to 60°), the peak stress and maximum strain on the femoral and tibial tunnel decreased from 30° to 45° and increased from 45° to 60°, respectively. With an increasing sagittal obliquity drilling angle (45° to 60°), the peak stress and the maximum strain on the bone tunnels increased. The lowest peak stress and maximum strain at the ACL tunnels were observed at 45° coronal/45° sagittal drilling angle (7.5 MPa and 7,568.3 μ-strain at the femoral tunnel entrance, and 4.0 MPa and 4,128.7 μ-strain at the tibial tunnel entrance). The lowest peak stress on the ACL graft occurred at 45° coronal/45° sagittal (27.8 MPa) drilling angle.

Conclusions: The femoral tunnel drilling angle could affect both the stress and strain distribution on the femoral tunnel, tibial tunnel, and graft. A femoral tunnel drilling angle of 45° coronal/ 45° sagittal demonstrated the lowest peak stress, maximum strain on the femoral and tibial tunnel entrance, and the lowest peak stress on the ACL graft.

Local variations in mechanical properties of human hamstring tendon autografts for anterior cruciate ligament reconstruction do not translate to a mechanically inferior strand

A ruptured anterior cruciate ligament (ACL) is often reconstructed with a multiple-strand autograft of a semitendinosus tendon alone or combined with a gracilis tendon. Up to 10% of patients experience graft rupture. This potentially results from excessive local tissue strains under physiological loading which could either result in direct mechanical failure of the graft or induce mechanobiological weakening. Since the original location in the hamstring tendon cannot be traced back from an autograft rupture site, this study explored whether clinical outcome could be further improved by avoiding specific locations or regions of human semitendinosus and/or gracilis tendons in ACL grafts due to potential mechanical or biochemical inferiority. Additionally, it examined numerically which clinically relevant graft configurations experience the lowest strains - and therefore the lowest rupture risk - when loaded with equal force. Remnant full-length gracilis tendons from human ACL reconstructions and full-length semitendinosus- and ipsilateral gracilis tendons of human cadaveric specimens were subjected to a stress-relaxation test. Locations at high risk of mechanical failure were identified using particle tracking to calculate local axial strains. As biochemical properties, the water-, collagen-, glycosaminoglycan- and DNA content per tissue region (representing graft strands) were determined. A viscoelastic lumped parameter model per tendon region was calculated. These models were applied in clinically relevant virtual graft configurations, which were exposed to physiological loading. Configurations that provided lower stiffness - i.e., experiencing higher strains under equal force - were assumed to be at higher risk of failure. Suitability of the gracilis tendon proper to replace semitendinosus muscle-tendon junction strands was examined. Deviations in local axial strains from the globally applied strain were of similar magnitude as the applied strain. Locations of maximum strains were uniformly distributed over tendon lengths. Biochemical compositions varied between tissue regions, but no trends were detected. Viscoelastic parameters were not significantly different between regions within a tendon, although semitendinosus tendons were stiffer than gracilis tendons. Virtual grafts with a full-length semitendinosus tendon alone or combined with a gracilis tendon displayed the lowest strains, whereas strains increased when gracilis tendon strands were tested for their suitability to replace semitendinosus muscle-tendon junction strands. Locations experiencing high local axial strains - which could increase risk of rupture - were present, but no specific region within any of the investigated graft configurations was found to be mechanically or biochemically deviant. Consequently, no specific tendon region could be indicated to provide a higher risk of rupture for mechanical or biochemical reasons. The semitendinosus tendon provided superior stiffness to a graft compared to the gracilis tendon. Therefore, based on our results it would be recommended to use the semitendinosus tendon, and use the gracilis tendon in cases where further reinforcement of the graft is needed to attain the desired length and cross-sectional area. All these data support current clinical standards.

Five- and six-strand hamstring grafts consistently produce appropriate graft diameters for anterior cruciate ligament reconstruction

PURPOSE

Hamstring tendon graft diameter less than 8 mm has been correlated with an increased risk of anterior cruciate ligament reconstruction (ACLR) graft failure. The purpose of this study was to measure and compare the diameter of 3-, 4-, 5-, and 6-strand gracilis and semitendinosus (ST) hamstring tendon (HT) ACLR grafts, and to determine if there is a correlation between anthropometric data, HT length, and diameter of the HT ACLR graft.

METHODS

Male patients (n = 78) undergoing primary or revision ACLR with a HT autograft between July 2018 and March 2020 were recruited. Pre-operative anthropometric data was collected. Gracilis and ST tendons were harvested and the length and diameter measured. The following HT graft configurations were prepared in each patient: triple ST; double gracilis + double ST; double gracilis + triple ST; triple gracilis + triple ST. Paired t-tests and Pearson's correlation coefficients were used to assess demographics, anthropometrics, graft diameter, and tendon length. A non-parametric test was used to compare femoral and tibial ACL graft diameters of the 3-, 4-, 5-, and 6-strand HT graft configurations.

RESULTS

For the femoral end, 10%, 19%, 69% and 86% of the patients achieved graft diameters of equal to or greater than 8 mm in 3-, 4-, 5- and 6-strand HT graft configurations respectively. For the tibial end, 27%, 10%, 83%, and 92% of the patients achieved graft diameters of equal to or greater than 8 mm in 3-, 4-, 5-, and 6-strand HT graft configurations respectively. The largest increases in HT graft diameters were noted between the femoral end of 6- vs. 3-strand grafts (mean difference 1.7 ± 0.5 mm; p < 0.001) and between the tibial end of 6- vs. 4-strand grafts (mean difference 2.0 ± 0.5 mm; p < 0.001). Height and leg length were moderately positively correlated with ST tendon length (r = 0.54-0.51) and gracilis tendon length (r = 0.52-0.45), and thigh and shank lengths were moderately positively correlated with ST tendon length (r = 0.43 and 0.40, respectively).

CONCLUSION

Traditional 4-strand HT ACL autografts in male patients undergoing ACLR in the United Arab Emirates result in graft diameters less than 8 mm in the majority of patients.

LEVEL OF EVIDENCE

III.

Quadrupled Hamstring Graft Diameter Adequacy in Anterior Cruciate Ligament Reconstruction Using Patient Anthropometry: A Prospective Cohort Study in Indian Males

Background and aim The diameter of the graft used for the reconstruction of the anterior cruciate ligament (ACL) is an important determinant for the overall strength and future outcome of the operative procedure. Preoperative prediction of quadrupled hamstrings autograft (QHAG) diameter can prove to be of help in forecasting the need for augmentation or alternative grafts like quadriceps, bone-patellar tendon-bone autograft, and synthetic grafts. The relationship between the preoperatively assessed anthropometric parameters and the obtained quadrupled hamstrings graft diameter has not been extensively studied, especially in the population of Indian origin. This study aimed at investigating whether a correlation exists between the measured anthropometric parameters like age, weight, height, thigh circumference, and body mass index (BMI) and the intraoperatively obtained diameter of hamstring graft for ACL reconstruction in the study population of Indian male subjects. Study design A prospective cohort study conducted in a tertiary care center and teaching hospital in a district in central Uttar Pradesh, India. Methods The preoperative anthropometric data (age, height, weight, BMI, and thigh circumference of the injured side) of 73 Indian male subjects undergoing primary ACL reconstructive surgeries between May 2018 and August 2020 were prospectively collected, and their respective intraoperative QHAG diameters measured and recorded. Pearson's correlation test was employed to determine the correlation between the preoperative demographic and anthropometric data and the obtained corresponding graft diameters. Simple linear regression was performed to obtain the graphical plots and determine the relationship between the dependent and independent variables. Of these, the variables showing significant association were subjected to stepwise linear regression to identify and exclude the confounder(s) and obtain the predicted equation. Results The study comprised 73 male participants. The study participants' mean age was found to be 33.7 years, mean height was 173.1 cm, mean weight was 71.2 kg, mean BMI was 23.7 kg/m², mean thigh circumference was 50.4 cm, and the obtained mean graft diameter was 8.0 mm. A strongly positive correlation was observed between height and the graft diameter (r=0.940, P=0.000) and thigh circumference and the graft diameter (r=0.769, P=0.000). In contrast, weight showed a moderately positive correlation with the graft diameter (r=0.514, P=0.000). A very weakly positive correlation was observed between the BMI of the subjects and the obtained graft diameters (r=0.236, P=0.045). However, no correlation was observed between the age and the final graft diameters (r=0.140, P=0.238). Subsequent linear regression analysis indicates that only height (R²=0.883, P=0.000; strong) and the thigh circumference (R²=0.591, P=0.000; moderate) share a significant predictive value for the obtained QHAG. Both height and thigh circumference together were good predictors for graft diameter as determined by multiple regression (F (2,70)=272.372, P<0.001), with an R² of 0.886. Conclusion Certain anthropometric parameters depict a positive correlation with the QHAG diameter and can assist in preoperative planning, predicting the possible harvested graft diameter and the need for alternative grafts or augmentation during ACL reconstructive surgeries.

Predictive Factors for Hamstring Autograft Diameter in Anterior Cruciate Ligament Reconstruction

Multiple studies found hamstring tendon (HT) autograft diameter to be a risk factor for anterior cruciate ligament (ACL) reconstruction failure. This study aimed to determine which preoperative measurements are associated with HT autograft diameter in ACL reconstruction by directly comparing patient characteristics and cross-sectional area (CSA) measurement of the semitendinosus and gracilis tendon on magnetic resonance imaging (MRI). Fifty-three patients with a primary ACL reconstruction with a four-stranded HT autograft were included in this study. Preoperatively we recorded length, weight, thigh circumference, gender, age, preinjury Tegner activity score, and CSA of the semitendinosus and gracilis tendon on MRI. Total CSA on MRI, weight, height, gender, and thigh circumference were all significantly correlated with HT autograft diameter (p < 0.05). A multiple linear regression model with CSA measurement of the HTs on MRI, weight, and height showed the most explained variance of HT autograft diameter (adjusted R ² = 44%). A regression equation was derived for an estimation of the expected intraoperative HT autograft diameter: 1.2508 + 0.0400 × total CSA (mm²) + 0.0100 × weight (kg) + 0.0296 × length (cm). The Bland and Altman analysis indicated a 95% limit of agreement of ± 1.14 mm and an error correlation of r = 0.47. Smaller CSA of the semitendinosus and gracilis tendon on MRI, shorter stature, lower weight, smaller thigh circumference, and female gender are associated with a smaller four-stranded HT autograft diameter in ACL reconstruction. Multiple linear regression analysis indicated that the combination of MRI CSA measurement, weight, and height is the strongest predictor.

Assessment of thickness of in vivo autograft tendons around the knee and its correlation with anthropometric data, thickness of patella and anterior cruciate ligament tibial foot print diameter

Inadequate diameters of the autograft tendons are known to be a major cause of graft failure in ligament reconstruction. The purpose of the study was to measure the in-vivo thickness of the available autograft options around the knee and to seek a correlation between the thickness of the tendons and the anthropometric data, patellar thickness and anterior cruciate ligament (ACL) footprint sagittal diameter. Magnetic resonance imaging of 104 consecutive patients with suspected knee injuries were utilized for measurement of the in vivo thickness of pes anserinus tendon (diameter and cross-sectional area [CSA]), patellar tendon (PT) and quadriceps tendon (QT). Pearson’s coefficient was used to find out the relationship between the tendon thickness and anthropometric data, thickness of patella and ACL tibial foot print sagittal diameter. The mean diameters and CSA of the semitendinosus tendon (ST) and gracilis tendon (GT) were 3.77±0.49 mm, 11.62±1.62 mm² and 2.87±0.27 mm, 6.64±1.18 mm² respectively. QT and PT thicknesses were 7.36±0.87 mm and 4.50±0.62 mm respectively. Height and the patellar thickness were seen to have moderate correlation with ST and PT thickness. Weak correlation was seen between the other anthropometric variables and tendon thickness. Magnetic resonance imaging (MRI) assessment of tendon sizes is a reliable method with good inter and intra-rater agreement. Assessment of these anatomical structures with help of MRI would be helpful in preoperative planning and can help in identifying those patients at risk of having smaller tendons.

Remnant Muscle Preservation on Hamstring Tendon Autograft During ACL Reconstruction Promotes Volumetric Increase With Biological and Regenerative Potential

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.

Editorial Commentary: Multiple-Strand Hamstring Autografts for Anterior Cruciate Ligament Reconstruction: If Graft Diameter Is at Least 8 Millimeters, Bigger May Not Be Better

Anterior cruciate ligament graft diameter is of concern to every orthopaedic surgeon who's ever performed an anterior cruciate ligament reconstruction. The current standard is to obtain a graft of at least 8 mm in diameter. The 5-bundle construct is an option to increase the graft diameter in the situation in which a smaller diameter 4-strand hamstring autograft is encountered. The question is whether bigger is better once one obtains an 8-mm diameter graft.

Relation of peroneus longus autograft dimensions with anthropometric parameters in anterior cruciate ligament reconstruction: Importance of the distal leg diameter

Objectives

This study aims to investigate the relationship between various anthropometric parameters and the diameter and length of the peroneus longus tendon (PLT) graft in the anterior cruciate ligament (ACL) reconstruction.

Patients and methods

A total of 52 patients (38 males, 14 females; mean age: 29.2±7.7 years; range, 17 to 51 years) who received PLT autograft for ACL reconstruction in our center between July 2018 and June 2020 were retrospectively analyzed. Demographic characteristics of the patients and leg length, and proximal and distal leg diameters were recorded before the operation. The PLT autograft diameter and length were measured during surgery.

Results

A statistically significant correlation was found between the graft diameter and length and weight, height, body mass index (BMI), leg length, and proximal and distal leg diameters (p<0.01). There was no statistically significant correlation between the graft diameter and length and age (p>0.05). Distal leg diameter had the highest correlation coefficient for the PLT autograft diameter (r=0.956), while the height had the highest correlation coefficient for the PLT autograft length (r=0.982).

Conclusion

Anthropometric parameters of height, weight, BMI, leg length, and proximal and distal leg diameters may be helpful for surgeons to predict the diameter and length of the PLT autograft before surgery. Distal leg diameter is a particularly important parameter in predicting PLT autograft diameter.

Revision ACL Reconstruction in Adolescent Patients

Background:

High failure rates have been documented after anterior cruciate ligament reconstruction (ACLR) in pediatric patients, and revision surgery is indicated due to high activity levels of children and adolescents.

Purpose:

To define trends in revision ACLR in patients who underwent initial ACLR at younger than 18 years.

Study Design:

Case series; Level of evidence, 4.

Methods:

An electronic medical record was used to retrospectively identify revision ACLR procedures performed by 2 surgeons between the years 2010 and 2016 in patients younger than 18 years at initial reconstruction. Descriptive information, intraoperative findings, surgical techniques, and rehabilitation data were recorded from initial and revision surgeries. Descriptive statistics were used.

Results:

A total of 32 patients (17 girls, 15 boys) met the inclusion criteria, with a mean age of 15.8 years at initial reconstruction. For initial reconstructions, 15 patients underwent transphyseal procedures, 3 patients underwent adult-type procedures using an anatomic reconstruction technique that did not take into account the physis, and 2 patients underwent partial intraepiphyseal procedures. Graft types included hamstring autograft (n = 17), allograft (n = 5), hybrid (n = 4), and bone–patellar tendon–bone autograft (BTB; n = 3). Average primary reconstruction graft diameter was 8.0 mm (girls, 7.72 mm; boys, 8.36 mm; P = .045). After initial reconstruction, 10 patients had postoperative protocol noncompliance, and 8 patients reported delayed recovery. Mean time to retear was 565 days (range, 25-1539 days). At revision, BTB autograft was used in 50% (n = 16), followed by hamstring autograph (31.3%; n = 10) and allograft (12.5%; n = 4); mean graft diameter was 9.05 mm. Chondral surgery was more common during revision (25% for revision vs 0% for index; P = .031). There were 4 patients who required staged reconstruction with bone grafting. At mean final follow-up of 29.5 months (SD, 22.2 months), there were 3 graft failures (9.4%) and 5 contralateral ACL ruptures (15.6%).

Conclusion:

Most patients with ACL graft failure were adequately treated with a single revision. Conversion from a soft tissue graft to a BTB autograft was the most common procedure. Infrequently, patients required staged reconstructions. Providers should have a high index of suspicion for associated intra-articular injuries resulting from graft failure in adolescent patients.

Failure Rates of 5-Strand and 6-Strand vs Quadrupled Hamstring Autograft ACL Reconstruction: A Comparative Study of 413 Patients With a Minimum 2-Year Follow-up

Background:

Anterior cruciate ligament reconstruction (ACLR) with hamstring autograft has gained popularity. However, an unpredictably small graft diameter has been a drawback of this technique. Smaller graft diameter has been associated with increased risk of revision, and increasing the number of strands has been reported as a successful technique to increase the graft diameter.

Purpose:

To compare failure rates of 5-strand (5HS) and 6-strand (6HS) hamstring autograft compared with conventional 4-strand (4HS) hamstring autograft. We describe the technique in detail, supplemented by photographs and illustrations, to provide a reproducible technique to avoid the variable and often insufficient 4HS graft diameter reported in the literature.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively reviewed prospectively collected data of all primary hamstring autograft ACLRs performed at our institution with a minimum 2-year follow-up and 8.0-mm graft diameter. A total of 413 consecutive knees met the study inclusion and exclusion criteria. The study population was divided into 5HS and 6HS groups as well as a 4HS control group. The primary outcome was failure of ACLR, defined as persistent or recurrent instability and/or revision ACLR.

Results:

The analysis included 224, 156, and 33 knees in the 5HS, 6HS, and 4HS groups, respectively. The overall ACLR failure rate in this study was 11 cases (8%): 5 cases for 5HS, 3 cases for 6HS, and 3 cases for 4HS. No statistically significant differences were found among groups (P = .06). The mean graft diameter was 9 mm, and the mean follow-up was 44.27 months.

Conclusion:

The 5HS and 6HS constructs have similar failure rates to the conventional 4HS construct of 8.0-mm diameter and are therefore safe and reliable to increase the diameter of relatively smaller hamstring autografts. We strongly recommend using this technique when the length of the tendons permits to avoid failures reportedly associated with inadequate graft size.

Developmental changes in ACLs and semitendinosus tendons dimensions according to age in children

PURPOSE

Managing anterior cruciate ligament (ACL) injuries in skeletally immature patients remains difficult. The main aim of this study was to retrospectively compile normative data on the cross-sectional area (CSA) of the semitendinosus tendon (ST) and the diameter of the ACL in children and young adults.

METHODS

Knee magnetic resonance imaging (MRI) examinations were performed for a 2-year period in 132 patients (83 female and 49 male patients). The mean age was 14.9 years (8-18 years). Measurements of the ST CSA were performed on axial views in greyscale by two independent researchers. The ACL diameter was measured as well.

RESULTS

The results show the CSA of the ST was related to age, and its growth was not linear. The highest growth rate of the CSA of the ST occurred at age 12-13 at the level of the femoral growth plate and at the level of the tibial plateau. The growth of the ACL diameter was linear until 18 years of age.

CONCLUSIONS

ST growth (measured in CSA increments) is almost complete at the age of 13, even though the growth is not linear. ACL growth measured in diameter increments proceeds linearly from 8 to 18 years of age. MRI is a clinically useful tool for assessing hamstring tendon grafts preoperatively.

LEVEL OF EVIDENCE

Level III, diagnostic studies.

Correlation between anthropometric measurements and activity level on length and diameter of semitendinosus tendon autograft in knee ligament surgery: A prospective observational study

Introduction: Preoperative estimation of graft parameters can be useful while using hamstring grafts in knee ligament surgeries. Anthropometric parameters may be an easy way to predict the length and diameter of hamstring tendons. A prospective study was conducted to find the correlation between different anthropometric parameters and activity level of the patient on the length and diameter of the graft. Separate regression equations for males and females were also derived for easy prediction. Methods: Data were obtained from 95 patients who underwent arthroscopic anterior cruciate ligament reconstruction with autologous hamstring tendon graft. Variables studied were age, sex, height, weight, body mass index (BMI), thigh circumference, thigh length, Tegner activity level, diameter (double and quadruple) and length of semitendinosus tendon graft. Results: Height of the patient had strong correlation with graft length (r = 0.41, p < 0.001), double diameter (r = 0.29, p = 0.008) and quadruple diameter (r = 0.3, p = 0.006). Weight of the patients had strong positive correlation with graft length (r = 0.34, p = 0.002) and quadruple diameter (r = 0.34, p = 0.002). Thigh length was found to be positively correlating with graft length (r = 0.43, p < 0.001), double diameter (r = 0.29, p = 0.007) and quadruple diameter of graft (r = 0.34, p = 0.002). BMI and thigh circumference of the patients were not found to correlate with graft size. Male patients were found to have longer semitendinosus graft and larger double and quadruple diameter of the graft. There was no association between the Tegner activity scale and graft size. Regression equations between graft length and quadruple diameter and the anthropometric parameters are also derived. Conclusion: Height, weight and thigh length are useful anthropometric parameters in the prediction of hamstring tendon size. However, the patient’s Tegner activity level was not found to be associated with size of the hamstring tendon.

Preoperative prediction of autologous hamstring graft diameter in anterior cruciate ligament reconstruction

BACKGROUND AND OBJECTIVE

Currently, there is no stablished pre-operative model that helps the orthopaedic surgeon predict the final graft diameter in anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to determine whether there is a correlation between semitendinosus (ST) and gracilis (GT) cross-sectional area (CSA) evaluated pre-operatively in mm² using magnetic resonance imaging (MRI) and the final intra-operative ST-GT autograft diameter in mm².

METHODS

A retrospective study was designed, 89 patients undergoing ACLR with hamstring autograft participated. We analysed ST-CSA (mm²) and GT-CSA (mm²) using pre-operative MRI, intra-operative autograft diameter, age, sex, side of the injury, weight, height and body mass index (BMI).

RESULTS

A moderate-strong correlation was identified between final autograft diameter and ST-GT CSA in MRI (Pearson correlation coefficient .6911 P<.001). We observed that, if the combination of ST-CSA and GT-STA is at least 19mm², the probability of obtaining an autograft with a diameter greater than or equal to 8mm is 91.8% or more. The ROC curve analysis demonstrated, in this model, that this predictive method on MRI correctly discriminates in over 95.6% of cases between achieving or otherwise an autograft greater than or equal to 8mm during surgery. Intra and interobserver concordance of the MRI measurements were excellent, as shown in the intraobserver intraclass correlation coefficient (CCI) of .79 and the interobserver CCI of .84 and .77 for the ST and GT respectively.

CONCLUSIONS

Preoperative determinations of ST-CSA and GT-CSA (mm²) using MRI correlate with the final autograft diameter. This method represents a reliable and reproducible model to predict the hamstring autograft diameter in ACLR.

LEVEL OF EVIDENCE

Retrospective cohort study, level IV.

CLINICAL RELEVANCE

A review of the available literature reveals a higher risk of ACL failure or re-rupture if the graft is smaller than 8mm in diameter. Despite being an important factor there is no established pre-operative model that predicts the final graft diameter. Knowing beforehand the possibilities of obtaining a hamstring autograft with a diameter greater than or equal to 8mm would help the orthopaedic surgeon to better plan the surgery and to anticipate the need for other graft options (such as bone-patellar-tendon-bone autograft or allografts, amongst other alternatives).

Anthropometric correlation with hamstring graft size in anterior cruciate ligament reconstruction among males

PURPOSE

Pre-operative knowledge of hamstring graft size for anterior cruciate ligament reconstruction (ACL) is of clinical importance and useful in making appropriate decisions about graft choice. This study investigated if there is any correlation between anthropometric measurements such as height, weight, body mass index, thigh length, and circumference with the size of hamstring tendon graft in anterior cruciate ligament reconstruction.

METHODS

The anthropometric data of 50 consecutive adult males, who underwent primary ACL reconstruction using quadruple hamstring autograft, were collected prospectively. Data analysis using Pearson's correlation test was performed and multiple logistic regression analysis was used to investigate any correlation not detected by Pearson's test and to eliminate confounders.

RESULTS

Patient's height and thigh length demonstrated a positive correlation with gracilis graft length (r = .464, P = .001, r = .456, P = .001, respectively) and semitendinosus graft length (r = .541, P = 000, r = .578, P = .000, respectively). While the patient's age was the only independent factor which had a positive correlation with the quadrupled hamstring graft diameter (r = .412, P = .004), multiple regression analysis showed abdominal girth had a significant negative correlation with gracilis (P = .04) and semitendinosus (P = .006) graft thickness.

CONCLUSION

This study demonstrated that some anthropometric measurements had a positive correlation with the hamstring graft length and diameter in male patients. Hence, these results provide preliminary support for the use of some anthropometric measurements in the preoperative planning and prediction of the hamstring graft length and diameter in anterior cruciate ligament reconstruction.

Anthropometric correlation with hamstring graft size in anterior cruciate ligament reconstruction among males

PURPOSE

Pre-operative knowledge of hamstring graft size for anterior cruciate ligament reconstruction (ACL) is of clinical importance and useful in making appropriate decisions about graft choice. This study investigated if there is any correlation between anthropometric measurements such as height, weight, body mass index, thigh length, and circumference with the size of hamstring tendon graft in anterior cruciate ligament reconstruction.

METHODS

The anthropometric data of 50 consecutive adult males, who underwent primary ACL reconstruction using quadruple hamstring autograft, were collected prospectively. Data analysis using Pearson's correlation test was performed and multiple logistic regression analysis was used to investigate any correlation not detected by Pearson's test and to eliminate confounders.

RESULTS

Patient's height and thigh length demonstrated a positive correlation with gracilis graft length (r = .464, P = .001, r = .456, P = .001, respectively) and semitendinosus graft length (r = .541, P = 000, r = .578, P = .000, respectively). While the patient's age was the only independent factor which had a positive correlation with the quadrupled hamstring graft diameter (r = .412, P = .004), multiple regression analysis showed abdominal girth had a significant negative correlation with gracilis (P = .04) and semitendinosus (P = .006) graft thickness.

CONCLUSION

This study demonstrated that some anthropometric measurements had a positive correlation with the hamstring graft length and diameter in male patients. Hence, these results provide preliminary support for the use of some anthropometric measurements in the preoperative planning and prediction of the hamstring graft length and diameter in anterior cruciate ligament reconstruction.

Reliability of Magnetic Resonance Imaging Prediction of Anterior Cruciate Ligament Autograft Size and Comparison of Radiologist and Orthopaedic Surgeon Predictions

Background:

In anterior cruciate ligament (ACL) reconstruction, hamstring tendon autografts <8 mm have been associated with increased failure rates. There has been no established modality by which orthopaedic surgeons can preoperatively predict graft sizes.

Purpose/Hypothesis:

The purposes of this study were to (1) determine whether routine magnetic resonance imaging (MRI) measurement of hamstring tendon cross-sectional area (CSA) can reliably be used by sports medicine fellowship–trained orthopaedic surgeons to predict graft size and (2) determine whether radiologists and sports medicine surgeons are able to discriminate grafts below a predetermined cutoff value. We hypothesized that radiologists will find a correlation between MRI measurement and intraoperative graft size. Similarly, orthopaedic surgeons will be able to correctly estimate the graft size based on MRI measurement.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

Included in this study were 30 consecutive patients (15 women and 15 men) (mean age, 23 years [range, 13-43 years]) for whom MRI-determined hamstring tendon CSA and graft size measurements could be compared. Patients were included if they had a preoperative MRI demonstrating acute ACL rupture and were scheduled with 1 of 3 surgeons for a reconstruction performed using the ST and GR tendons. Operative data were collected over 1 year. Sectra imaging software was used to measure the CSA of the semitendinosus (ST) and gracilis (GR) tendons on the preoperative MRIs. Control measurements were performed intraoperatively using a graft sizing block with 0.5-mm increments. Simple linear regression analysis was used to evaluate the ability of MRI measurements to predict autograft size. Logistic regression was used to determine the minimum CSA for a graft of 8 mm. The intraclass correlation coefficient (ICC) was used to evaluate interrater reliability.

Results:

MRI CSA measurement of the average STGR (ST CSA added to the GR CSA) was a significant predictor of graft size (adjusted R² = 0.186; P < .001). The 3 measurements with the strongest correlations with graft size were the ST at the medial femoral condyle (MFC), the STGR at the MFC, and the average STGR. The minimum CSA for the average STGR on MRI to achieve a graft size of 8 mm was 17.168 mm² (P < .001). The area under the receiver operating characteristic curve was 0.765. The overall ICC was 0.977.

Conclusion:

Routine preoperative MRI can be used by both radiologists and orthopaedic surgeons to predict the expected ACL autograft size and identify those below a cutoff of 8 mm. This will help in preoperative planning and graft selection.

Prediction of Autograft Hamstring Size for Anterior Cruciate Ligament Reconstruction Using MRI

BACKGROUND

Hamstring autografts with a diameter of less than 8 mm for ACL reconstruction have an increased risk of failure, but there is no consensus regarding the best method to predict autograft size in ACL reconstruction.

QUESTIONS/PURPOSES

(1) What is the relationship between hamstring cross-section on preoperative MRI and intraoperative autograft size? (2) What is the minimum hamstring tendon cross-sectional area on MRI needed to produce an autograft of at least 8 mm at its thickest point?

METHODS

This was a retrospective cohort study of 68 patients. We collectively reviewed patients who underwent ACL reconstruction by three separate fellowship-trained surgeons at the Carilion Clinic between April 2010 and July 2013. We searched the patient records database of each surgeon using the keyword "ACL". A total of 293 ACL reconstructions were performed during that time period. Of those, 23% (68 patients) had their preoperative MRI (1.5 T or 3 T magnet) performed at the Carilion Clinic with MRI confirmation of acute total ACL rupture. Exclusion criteria included previous ACL reconstructions, multiligamentous injuries, and history of acute hamstring injuries.After applying the exclusion criteria, there were 29 patients in the 1.5 T magnet group and 39 in the 3 T group. Median age (range) was 29 years (12 to 50) for the 1.5 T group and 19 years (9 to 43) for the 3 T group. The patients were 41% female in the 1.5 T group and 23% female in the 3 T group. Use of 1.5 T or 3 T magnets was based on clinical availability and scheduling. The graft's preoperative cross-sectional area was compared with the intraoperative graft's diameter. The MRI measurements were performed by a single musculoskeletal radiologist at the widest point of the medial femoral condyle and at the joint line. Intraoperative measurements were performed by recording the smallest hole the graft could fit through at its widest point. Pearson's correlation coefficients were calculated to determine the relationship between graft size and tendon cross-sectional area. A simple logistic regression analysis was used to calculate the cutoff cross-sectional areas needed for a graft measuring at least 8 mm at its thickest point. Intrarater reliability was evaluated based on re-measurement of 19 tendons, which produced an overall intraclass correlation coefficient (ICC) of 0.96 95% (CI 0.93 to 0.98). A p value < 0.05 was considered significant.

RESULTS

In general, the correlation between MRI-measured hamstring thickness and hamstring graft thickness as measured in the operating room were good but not excellent. The three measurements that demonstrated the strongest correlation with graft size in the 1.5 T group were the semitendinosus at the medial femoral condyle (r = 0.69; p < 0.001), the semitendinosus and gracilis at the medial femoral condyle (r = 0.70; p < 0.001), and the mean semitendinosus and gracilis (r = 0.64; p < 0.001). These three measurements had correlation values of 0.53, 0.56, and 0.56, respectively, in the 3 T MRI group (all p values < 0.001). To create an 8-mm hamstring autograft, the mean semitendinosus plus gracilis cutoff values areas were 18.8 mm and 17.5 mm for the 1.5 T and 3.0 T MRI groups, respectively.

CONCLUSIONS

Imaging performed according to routine knee injury protocol can be used to preoperatively predict the size of hamstring autografts for ACL reconstructions. In clinical practice, this can assist orthopaedic surgeons in graft selection and surgical planning.

LEVEL OF EVIDENCE

Level II, diagnostic study.

The medial epicondyle of the distal femur is the optimal location for MRI measurement of semitendinosus and gracilis tendon cross-sectional area

PURPOSE

Graft diameter ≥ 8 mm reduces the risk of failure after anterior cruciate ligament reconstruction (ALCR) with hamstring tendon autograft. Pre-operative measurement of gracilis (GT) and semitendinosus (ST) cross-sectional area using MRI has been utilized but the optimal location for measurement is unknown. The main purpose of this study was to examine the cross-sectional areas of GT + ST at different locations and develop a model to predict whether a doubled hamstring graft of GT + ST will be of sufficient cross-sectional area for ACLR.

METHODS

A retrospective review was performed of 154 patients who underwent primary ACLR using doubled hamstring autograft. Cross-sectional area measurements of GT + ST on pre-operative MRI axial images were made at three locations: medial epicondyle (ME), tibiofemoral joint line (TJL), and tibial physeal scar (TPS) and calculated the correlation of intra-operative graft size for each location using the Pearson's correlation coefficient. A receiver operating characteristic (ROC) established a threshold that would predict graft diameter ≥ 8 mm.

RESULTS

Measurement of GT + ST at the ME had a stronger correlation (r = 0.389) to intra-operative graft diameter than measurements at the TJL (r = 0.256) or TPS (r = 0.240). The ROC indicated good predictive value for hamstring graft diameter ≥ 8 mm based on MRI measurement at the ME with the optimal threshold with the highest sensitivity and specificity as 18 mm².

CONCLUSION

Cross-sectional area measurement of GT + ST at the ME correlated most closely to intra-operative diameter of a doubled hamstring autograft compared to measurements at the TJL or the TPS. As graft diameter < 8 mm is correlated with higher failure rates of ACL surgery, the ability to pre-operatively predict graft diameter is clinically useful.

LEVEL OF EVIDENCE

Level III, prognostic study.

Superior knee flexor strength at 2 years with all-inside short-graft anterior cruciate ligament reconstruction vs a conventional hamstring technique

PURPOSE

To compare the "all-inside technique" for anterior cruciate ligament (ACL) reconstruction using a short, quadrupled semitendinosus tendon (ST4) autograft and suspensory cortical fixation on both the femoral and tibial side vs the "conventional technique" using a semitendinosus/gracilis (ST/G) autograft fixed with a suspensory device on the femoral side and with an interference screw on the tibial side, in terms of clinical and functional outcomes.

METHODS

A total of 90 patients were enrolled, randomised into two groups, and prospectively followed. Group A comprised 45 patients treated with the all-inside technique and Group B included 45 patients treated with the conventional ACL technique (55 males, 35 females; mean age 28.7 ± 11.3 years). Patients completed the Lysholm knee score, the International Knee Documentation Committee (IKDC) score, the Knee Injury and Osteoarthritis Score (KOOS), and the Knee Society Score (KSS) preoperatively and at 2 years postoperatively. Anterior tibial translation measurement (KT-1000 arthrometer) and isokinetic testing of the operative vs non-operative limb were also conducted and the limb symmetry index (LSI) was determined.

RESULTS

At 24 months, the Lysholm, IKDC, KOOS, and KSS scores between the two groups were similar (n.s.). Anterior tibial translation between the operative and non-operative knee was also similar among the two groups (n.s.). Patients of Group A had significantly higher mean LSIs in terms of flexor peak torque (1.0 ± 0.1 vs 0.9 ± 0.1; p < 0.001), time-to-peak (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) and total work (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) at 180°/s, and significantly better mean LSI for isometric flexor/extensor ratio at 90° (1.1 ± 0.3 vs 0.8 ± 0.2; p < 0.001).

CONCLUSION

The all-inside ACL reconstruction with an ST4 autograft and cortical button fixation on both ends is a viable alternative to the conventional technique. It affords preservation of knee flexor strength, which is of advantage, especially when treating athletes with ACL injury.

LEVEL OF EVIDENCE

I.

Influence of anthropometric features on peroneus longus graft diameter in Anterior Cruciate Ligament reconstruction: A cohort study

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.

•

Gender.

•

Height.

•

Weight.

•

Body Mass Index.

•

Peroneus longus tendon diameter.

•

Patients' characteristics in preoperative measurements can predict graft diameter intraoperatively.

Preoperative Ultrasound Evaluation of the Semitendinosus Tendon for Anterior Cruciate Ligament Reconstruction

BACKGROUND

Adequate graft size and length are crucial factors that correlate with improved outcomes after anterior cruciate ligament reconstruction with a semitendinosus (ST) tendon autograft alone. Anthropometric parameters could be used as predictors of graft measurements but they have shown imprecise correlation in some patients.

PURPOSE

To evaluate the accuracy of ultrasound (US) for the preoperative evaluation of ST graft size and length.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

A total of 40 patients were included in this study. Patient sex, age, anthropometric parameters, and preoperative US measurements were recorded. After the ST tendons were harvested, their lengths as well as the diameters of the 4-strand ST grafts were recorded. Correlations between patient US measurements were analyzed. Inadequate ST graft length was defined at <28 cm, and inadequate 4-strand ST graft diameter was defined at <8 mm.

RESULTS

The prevalence of patients with an ST graft length <28 cm was 47.5%, and the prevalence of patients with a 4-strand ST graft diameter <8 mm was 42.5%. US measurements had a strong, significant correlation with the ST graft length (P < .001) and a moderate correlation with the 4-strand ST graft diameter (P < .001). Absolute agreement between the preoperative US measurement of ST graft length and the intraoperative ST graft length showed good reliability (ICC_2,1 = 0.825). The cross-sectional area (CSA) of the ST tendon at the knee joint level by US showed a weak correlation (r = 0.207) with the 4-strand ST graft diameter (P = .200). A CSA of 16 mm² measured by US could be used to predict a 4-strand ST graft diameter ≥8 mm, with a sensitivity of 73.9% and specificity of 76.5%.

CONCLUSION

Preoperative US measurements of ST tendons had a strong correlation with intraoperative ST graft length and provided good sensitivity to detect a 4-strand ST graft diameter ≥8 mm. All other anthropometric parameters showed a weak to moderate correlation with ST graft length and size.

Predicting the graft diameter of the peroneus longus tendon for anterior cruciate ligament reconstruction

The aim of this study was to evaluate the correlation between various anthropometric parameters and the graft diameter of the peroneus longus tendon (PLT).We retrospectively analyzed the data of 156 patients who underwent anterior cruciate ligament reconstruction (ACLR) with the PLT graft at our institution. Anthropometric parameters, including height, weight, gender, age, duration of injury, and preinjury activity levels, were recorded. t tests, correlation coefficients (Pearson r), and a multiple linear regression analysis were used to evaluate the influence of these anthropometric variables on the diameter of the graft obtained.The mean PLT graft diameter was 8.3 mm, and 21 patients (13.5%) had a diameter less than 8 mm; 85 patients (54.5%) had a diameter between 8 and 9 mm, and 50 patients (32.0%) had a diameter greater than or equal to 9 mm. The correlation analysis showed that height (P < .001), weight (P < .001), and duration of injury (P = .012) were significantly related to graft diameter. On the basis of these 3 predictors, the following regression equation was obtained: Diameter = 2.28 + 0.028*height (cm) + 0.013*weight (kg) + 0.289*duration of injury (0 or 1). Patients who were short and shin were more likely to own smaller graft diameters (<8 mm), especially the one ruptured his or her anterior cruciate ligament (ACL) over 3 months.Height, weight, and duration of injury were associated with the diameter of PLT. They are important preoperative information for surgeon about the size of PLT and can be used for alternative graft source planning and patient counseling.Level of evidence: IV.

Use of the 5-Strand Hamstring Autograft Technique in Increasing Graft Size in Anterior Cruciate Ligament Reconstruction

BACKGROUND

To determine the extent to which a strategy of routinely preparing a 5-strand hamstring autograft would increase graft size in anterior cruciate ligament (ACL) reconstruction.

METHODS

A total of 64 patients were enrolled in a prospective randomized controlled study comparing 5-strand and quadrupled semitendinosus-gracilis autografts in single-bundle ACL reconstruction (5-strand group, n = 32; 4-strand group, n = 32). In the 5-strand group, the diameter of the 4-strand construct and the subsequent 5-strand graft used were measured, whereas in the 4-strand group, the diameter of the quadrupled graft used was measured. Quadrupled graft diameter and hamstring tendon lengths were correlated with patient gender, height, weight, and body mass index (BMI).

RESULTS

The mean diameter of the final graft used in the 5-strand group was 8.8 ± 0.8 mm, whereas that in the 4-strand group was 7.8 ± 0.7 mm (P < .001). The mean increase in graft size achieved with the use of the 5-strand technique was 1.4 ± 0.3 mm. In the 5-strand group, 24 of 32 (75%) patients had graft diameters exceeding 8 mm compared with 9 of 32 (28%) patients in the 4-strand group (P < .001). Quadrupled graft diameter was significantly correlated with patient height and BMI, whereas the gracilis and semitendinosus lengths were significantly correlated with patient height.

CONCLUSIONS

The 5-strand hamstring autograft provides a significantly larger diameter graft compared with the quadrupled hamstring autograft in ACL reconstruction. Graft sizes exceeding 8 mm are achievable in 75% of patients with the routine application of this technique. This is significantly more than that obtained with the standard quadrupled hamstring graft. Hamstring tendon length and quadrupled hamstring graft diameter are also significantly correlated with patient height.

LEVEL OF EVIDENCE

Level 1, prospective randomized controlled trial.

A 5-Strand Hamstring Autograft Achieves Outcomes Comparable to Those of a 4-Strand Hamstring Autograft With a Graft Diameter of 8 mm or More in Anterior Cruciate Ligament Reconstruction

Background:

Quadrupled (4-strand) hamstring tendon autografts are commonly used in anterior cruciate ligament (ACL) reconstruction, but there is significant variability in their diameter. The 5-strand hamstring autograft has been used as a means of increasing the graft diameter in patients with undersized hamstring grafts.

Purpose:

To report the outcomes of primary ACL reconstruction using 5-strand hamstring autografts in patients in whom the 4-strand configuration produced a graft diameter of <8 mm and to compare these outcomes with those of ACL reconstruction using 4-strand semitendinosus-gracilis autografts with a graft diameter of ≥8 mm.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

The primary study group comprised 25 patients who underwent ACL reconstruction using a 5-strand hamstring autograft. The comparison group comprised 20 patients who underwent ACL reconstruction using a 4-strand hamstring autograft with a graft diameter of ≥8 mm. Interference screw fixation was used at the tibial and femoral ends for both groups of patients. Subjective questionnaires, including the Knee injury and Osteoarthritis Outcome Score (KOOS), the Lysholm score, and the Physical Component Summary and Mental Component Summary of the Short Form–36 (SF-36), were administered preoperatively as well as at 1- and 2-year follow-up visits.

Results:

There were no significant differences in the patient demographics and preoperative scores between the 2 groups. The mean graft diameter was 9.06 ± 0.60 mm in the 5-strand group and 8.13 ± 0.32 mm in the 4-strand group (P < .05). There was no statistically significant difference between groups on postoperative Lysholm, KOOS Pain, KOOS Symptoms, KOOS Activities of Daily Living, KOOS Sports, KOOS Quality of Life, and SF-36 Physical Component Summary scores.

Conclusion:

In primary ACL reconstruction, the 5-strand hamstring autograft achieves clinical outcomes that are comparable to those of the 4-strand hamstring autograft with a graft diameter of ≥8 mm. The 5-strand graft technique is therefore a useful means of increasing the graft diameter when faced with an undersized hamstring graft.

Anthropometric and Skeletal Parameters Predict 2-Strand Semitendinosus Tendon Size in Double-Bundle Anterior Cruciate Ligament Reconstruction

Background:

Few studies have examined whether skeletal parameters predict hamstring graft size during anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis:

The purpose of this study was to examine whether preoperative anthropometric and radiographic skeletal parameters could predict hamstring graft size during ACLR. We hypothesized that both anthropometric and skeletal parameters can be used to predict graft size in our double-bundle procedure and that the use of skeletal parameters will improve the accuracy of graft size prediction.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 200 patients were recruited and underwent double-bundle ACLR using a semitendinosus (ST) graft. The harvested tendon was measured to determine graft length (GL) and then split at its midpoint. The graft diameters of the anteromedial (GD_AM) and posterolateral bundles (GD_PL) were measured at the femoral aspect of the 2-stranded graft. The mean diameters of both bundles were included in the analysis. On the coronal radiograph, femorotibial angle (FTA), femoral interepicondylar distance (IED), and tibial plateau width (coronal tibial width [CTW]) were measured. Blumensaat line length (BLL) and the lateral tibial width (LTW) were measured on the lateral radiograph. A linear regression analysis was conducted using graft size as the dependent variable and age, sex, height, weight, Tegner activity score, and skeletal parameters as the independent variables.

Results:

Mean GL was 258.9 ± 21.9 mm, GD_AM was 5.9 ± 0.5 mm, and GD_PL was 5.7 ± 0.6 mm. Single regression analysis showed that GL was significantly predicted by sex, height, weight, Tegner activity score, IED, CTW, BLL, and LTW (R² range, 0.033-0.342). GD was predicted by sex, height, weight, IED, CTW, BLL, and LTW (R² range, 0.094-0.207). Stepwise multiple linear regression analysis significantly confirmed sex, height, and age as the variables to comprehensively predict GL (R² = 0.384). With regard to GD, stepwise multiple regression confirmed height and IED as significant variables (R² = 0.224).

Conclusion:

Both preoperative anthropometric and radiographic parameters on plain radiographs were able to predict harvested GL and 2-strand GD. Multivariate regression slightly improved the prediction of graft dimensions compared with univariate regression.

Use of Magnetic Resonance Imaging to Predict Quadrupled Semitendinosus Graft Diameter in All-Inside Anterior Cruciate Ligament Reconstruction

This study was conducted to evaluate whether preoperative magnetic resonance imaging (MRI) measurements of the cross-sectional area and length of the semitendinosus tendon correlated with graft diameter. The goal of the study was to identify tendons at risk for requiring graft augmentation. The records of 140 consecutive patients undergoing anterior cruciate ligament (ACL) reconstruction between 2013 and 2016 were examined retrospectively. The study included 39 patients who underwent all-inside ACL reconstruction with a semitendinosus autograft. A single researcher used preoperative MRI scans to measure the cross-sectional area and length of the semitendinosus tendon. Graft cross-sectional area was correlated with semitendinosus tendon cross-sectional area with Pear-son's coefficients of 0.50 (95% confidence interval [CI], 0.21-0.70; P=.0013) and 0.59 (95% CI, 0.34-0.76; P=.0001) when measured under 2× and 4× magnification, respectively. In addition, MRI measurements of semitendinosus tendon length were correlated with both intraoperatively measured tendon length (r=0.75; 95% CI, 0.40-0.91; P=.0008) and graft diameter (r=0.43; 95% CI, 0.14-0.66; P=.0058). Average semitendinosus tendon cross-sectional area was 3.10 mm² (95% CI, 0.53-5.67; P=.024) greater and semitendinosus tendon length was 14.05 mm (95% CI, 1.25-26.85; P=.035) greater in cases that did not require graft augmentation. Semitendinosus tendons with cross-sectional area of less than 13.2 mm² or length of less than 81 mm are most likely to require graft augmentation. In addition, MRI measurements of the length and cross-sectional area of the semitendinosus tendon are significantly correlated with ACL graft diameter and could help to identify patients who may require graft augmentation. [Orthopedics. 2017; 40(4):e617-e622.].

Anterior cruciate ligament reconstruction: principles of treatment

Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures in sports medicine. Several areas of controversy exist in ACL tear management which have engaged surgeons and researchers in debates towards identifying an ideal approach for these patients.

This instructional review discusses the principles of ACL reconstruction in an attempt to provide guidelines and initiate a critical thinking approach on the most common areas of controversy regarding ACL reconstruction.

Using high-level evidence from the literature, as presented in randomised controlled trials, systematic reviews, and meta-analyses, operative versus conservative treatment, timing of surgery, and rehabilitation are discussed. Also, the advantages and disadvantages of the most common types of autografts, such as patellar tendon and hamstrings as well as allografts are presented.

Key considerations for the anatomical, histological, biomechanical and clinical data (‘IDEAL’) graft positioning are reviewed.

Cite this article: Paschos NK, Howell SM. Anterior cruciate ligament reconstruction: principles of treatment. EFORT Open Rev 2016;398-408. DOI: 10.1302/2058-5241.1.160032.

Equation-based precise prediction of length of hamstring tendons and quadrupled graft diameter by various anthropometric variables for knee ligament reconstruction in Indian population

Preoperative prediction of hamstring tendon lengths and graft diameter for anterior cruciate ligament (ACL) reconstruction enables better preoperative planning. Presently, no study exists for Indian population where both derivation and verification of a mathematical equation for accurate prediction of hamstring graft dimensions have been done. This study was conducted in two phases: First phase ( derivation cohort): devoted to the study of correlation of length of hamstring tendons and graft diameter with various anthropometric measurements in 123 patients undergoing ACL reconstruction. Length of semitendinosus (ST) was observed to have a strong correlation with leg length ( r = 0.719), whereas that of gracilis (G) had a strong correlation with patient height ( r = 0.768). Quadrupled diameter (QD) had a strong correlation with patient height and thigh length ( r = 0.685 and 0.680, respectively). Using Pearson correlation coefficient, multiple stepwise linear regressions, and analysis of variance test, predictive equations were developed to predict the length of ST and G and QD. Second phase ( verification cohort): This was a blinded prospective study done on 300 patients to further authenticate and test the accuracy of equations developed. Here, a steady correlation was found between the observed and predicted values of length of ST, G and QD, with correlation coefficients being 0.838, 0.847, and 0.767, respectively. Thus, we can safely conclude that clinically measurable anthropometric variables can reliably predict hamstring graft dimensions. This is likely to prove useful in better preoperative planning of ligament reconstructions.