Small hamstring autograft is defined by a cut-off diameter of 7 mm and not recommended with allograft augmentation in single-bundle ACL reconstruction

  • Huijun Kang
  • Conglei Dong
  • Fei WangEmail author



The present study was to analyze graft failure rates of hamstring tendon (HT) autografts with a cut-off graft diameter of 8 mm or 7 mm, and compare clinical outcomes between augmented small HT with an allograft and non-augmented relatively large HT in single-bundle anterior cruciate ligament reconstruction (ACLR).


A literature search of PubMed, EMBASE, and the Cochrane Library was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines. Studies to assess graft failure of autologous HT ACLR were reviewed, and graft failure rates with a cut-off graft diameter of 8 mm or 7 mm were further extracted. Clinical comparative studies of ACLR between augmented small HT with an allograft and non-augmented relatively large HT autografts were also included. Results are presented as risk ratio (RR) for binary data and weighted mean difference for continuous data with 95% confidence intervals (CI).


Nine studies with 2243 knees were included. Four studies examined the effect of HT autograft diameter on graft failure and five studies assessed clinical outcomes of allograft augmentation to small HT autografts. No significant difference was noted in graft failure with a cut-off diameter of 8 mm. No significant difference was found between diameters > 7 and ≤ 7 mm, but a significant difference was observed between diameters ≥ 7 and < 7 mm (RR = 0.49; 95% CI 0.26–0.92, I2 = 0%, P = 0.03). A trend towards increased risk of graft failure was noted for allograft-augmented HT compared with non-augmented HT autografts (RR = 0.43; 95% CI 0.18–1.02, I2 = 0%), but no significant differences were noted in IKDC, Lysholm, and Tegner scores between these groups.


The present study did support the use of 7 mm as a reference for cut-off diameter for small HT autografts, but not allograft augmentation to small HT autografts. These findings would guide clinical application of small HT autografts in single-bundle ACLR.

Level of evidence



ACL reconstruction Small hamstring Graft diameter Hybrid graft Augmentation 



We thank Peter Mittwede, MD, PhD, from Liwen Bianji, Edanz Editing China (, for editing the English text of a draft of this manuscript.


There is no funding source.

Compliance with ethical standards

Conflict of interest

All authors declare that they have no conflict of interest.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Supplementary material

167_2019_5475_MOESM1_ESM.doc (30 kb)
Supplementary material 1 (DOC 29 KB)


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Copyright information

© European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2019

Authors and Affiliations

  1. 1.Department of Joint SurgeryThird Hospital of Hebei Medical UniversityShijiazhuangChina

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