Predictive Factors for Hamstring Autograft Diameter in Anterior Cruciate Ligament Reconstruction

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.

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.

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.

Application of human data to predict hamstring tendon autograft diameter in Zhuang population

BACKGROUND

To explore the value of human data from the Zhuang population via predicting the diameter of the hamstring tendon autograft in anterior cruciate ligament (ACL) reconstruction and determining the feasibility of preoperative ultrasound for prediction.

METHODS

In total, 24 Zhuang patients who underwent ACL reconstruction with a 4-strand semitendinosus and gracilis tendon autograft (4 S-STG) were enrolled in this study. Before the operation, the affected semitendinosus tendon (ST) was examined by ultrasonography, and its length, diameter, cross-sectional area, and circumference were measured. The patients' basic information and body data, ie, height, weight, body mass index, lower limb length injured, and thigh circumference injured, were recorded. Their ST and gracilis tendon lengths and diameters and 4 S-STG diameter were measured during the operation. A correlation analysis was conducted between the ultrasound measurement results and human data and intraoperative tendon measurements.

RESULTS

The ST diameter measured by ultrasound was correlated with the ST length and ST diameter measured during operation, and the ST circumference measured by ultrasound was correlated with the ST diameter measured during operation. The patients' body weight can be used to distinguish a 4 S-STG diameter of ≥8 mm (P < .01, mean difference = 11.59). The area under the receiver operating characteristic curve of body weight was 0.829. The final graft diameter ≥8 mm could be predicted with a body weight of 61.5 kg as the cutoff point; the sensitivity and specificity were 72.2% and 83.3%, respectively.

CONCLUSION

In Zhuang patients undergoing ACL reconstruction with 4 S-STG, body weight more accurately predicted graft diameter than preoperative semitendinosus diameter.

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.

Predicting autologous hamstring graft diameter and finding reliable measurement levels in the Zhuang population using preoperative ultrasonography

Purpose: To evaluate the feasibility of using ultrasonography to preoperatively predict the autologous hamstring graft diameter for anterior cruciate ligament (ACL) reconstruction in the Zhuang population and determine a reliable measurement level using ultrasound.

Methods: Twenty-four Zhuang patients who were scheduled for ACL reconstruction using four-strand semitendinosus tendon (ST) and gracilis tendon (G) (4S-STG) autografts were included in this study. Ultrasonographic examinations of the ST and the G on the damaged side were conducted before the operation. We recorded the transverse diameter (TD), anterior–posterior diameter (APD), cross-sectional area (CSA), and perimeter (P) of the tendons. The measurements were obtained from two levels of the tendons: the widest point of the medial femoral epicondyle (level 1) and the myotendinous junction of the sartorius (level 2). We also calculated the combined (ST + G) TD, APD, CSA, and p values. Then, we obtained the intraoperative measurements. The correlation between the ultrasonic and intraoperative measurements was analyzed, and the advantages of the ultrasonic measurements at the two different levels were compared.

Results: When we measured at level 1, we found that part of the ultrasonic measurements were correlated with intraoperative measurements. The preoperative CSA of the G (P-GCSA) can be used to distinguish a 4S-STG autograft diameter of ≥8 mm (p < 0.01, mean difference = 3.7). The area under the P-GCSA curve was 0.801 (p < 0.05). A P-GCSA of 8.5 mm² could be used to predict a 4S-STG autograft diameter of ≥8 mm with a sensitivity of 61.1% and specificity of 83.3%. However, there was no correlation between the ultrasonic and intraoperative measurements at level 2.

Conclusion: Preoperative ultrasound can be used to predict the sufficient diameter of 4S-STG autografts when considering patients from Zhuang who are undergoing ACL reconstruction. The ultrasonic measurement should be obtained at the widest point of the medial femoral epicondyle.

Ultrasound Imaging in Predicting the Autograft Size in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

Anterior cruciate ligament (ACL) reconstruction is widely used to restore knee stability after injury, but the risk of revision surgery increases when the autograft size is inadequate. Ultrasound (US) measurements of preoperative target tendons have been applied to predict the intraoperative autograft size, with various outcomes across different studies. This systematic review and meta-analysis aimed to summarize the evidence and investigate the usefulness of US in predicting autograft size. Electronic databases were searched for relevant studies from inception to 19 January 2022. The primary outcome was the correlation between the preoperative US measurements of donor tendons and intraoperative autograft size. The secondary outcomes encompassed the predictive performance of US for autograft size and the comparison between US and magnetic resonance imaging (MRI) for preoperative tendon measurements. Nine studies, comprising 249 patients, were enrolled. The preoperative US measurements of the donor tendons demonstrated a significant positive correlation with their intraoperative autograft diameter, with a pooled correlation coefficient of 0.443 (95% confidence interval [CI], 0.266−0.591, p < 0.001) for the gracilis and semitendinosus autograft, 0.525 (95% CI, 0.114−0.783, p = 0.015) for the semitendinosus autograft, and 0.475 (95% CI, 0.187−0.687, p = 0.002) for the gracilis autograft. The pooled sensitivity and specificity of US imaging in predicting the autograft diameter were 0.83 (95% CI 0.57−0.95) and 0.70 (95% CI, 0.36−0.91), respectively. Moreover, no significant differences were observed between US and MRI measurements in predicting the sizes of the gracilis and semitendinosus autografts. Preoperative US measurements of the target tendons were moderately correlated with the intraoperative autograft size. US imaging has a discriminative performance similar to that of MRI in predicting the autograft size. A standardized US scanning protocol is needed for future studies to minimize the variations in tendon measurements across different investigators and increase the comparability of US imaging with intraoperative findings.

[Research progress of internal tension relieving technique in assisting anterior cruciate ligament reconstruction]

Objective

To review the research progress of internal tension relieving technique in assisting anterior cruciate ligament (ACL) reconstruction with tendon grafts.

Methods

The in vivo and in vitro biomechanical tests, animal experiments, and clinical studies on the use of internal tensioning relieving technique assisted ACL reconstruction in recent years were extensively reviewed, the impact of this technology on the biomechanics, histological changes of grafts, and the clinical effectiveness were analyzed and summarized.

Results

The internal tensioning relieving technique based on non-absorbable high-strength sutures can reduce the risk of relaxation and rupture by enhancing the biomechanical strength of tendon grafts in vitro and in vivo, it shows good biocompatibility and support for the ligamentation of the tendon grafts and the establishment of the direct tendon-bone interface in terms of histology. This technique improves postoperative initial joint stability, range of motion, and functional scores in clinical practic, when combining with the enhanced recovery after surgery can effectively promote patients to return to pre-injury exercise level without serious complications.

Conclusion

The preliminary research results have confirmed the efficacy and safety of the internal tension relieving technique on assisting ACL reconstruction, then showes some degree of significance and prospect, but more research is needed to further optimize tension-relieving devices and related surgical techniques, and clarify the specific effects of this technique on graft's structure remodeling, biomechanical function, and long-term clinical results.