ACL graft compression: a method to allow reduced tunnel sizes in ACL reconstruction
File(s)
Accepted version
Author(s)
Lord, Breck R
Colaco, Henry B
Gupte, Chinmay M
Wilson, Adrian J
Amis, Andrew A
Type
Journal Article
Abstract
PURPOSE: A common problem during ACL reconstruction is asymmetry of proximal-distal graft diameter leading to tunnel upsizing and graft-tunnel mismatch. Compression downsizing provides a graft of uniform size, allowing easy passage into a smaller tunnel. The purpose of this study was to quantify the graft compression technique and its effects on graft biomechanics and stability. It was hypothesised that compression downsizing would significantly reduce cross-sectional area (CSA); that no significant changes in graft biomechanics would occur; graft fixation stability would be improved. METHOD: Sixty-eight non-irradiated peroneus longus (PL) tendons were investigated. Twenty were halved and paired into ten four-strand grafts, 20 strands were compressed by 0.5-1 mm diameter and changes in CSA recorded using an alginate mould technique. The following properties were compared with 20 control strands: cyclic strain when loaded 70-220 N for 1000 cycles; stiffness; ultimate tensile load and stress; Young's modulus. 24 PL tendons were quadrupled into grafts, 12 were compressed and all 24 were submerged in Ringer's solution at 37 °C and the CSA recorded over 12 h. Twelve compressed and 12 control quadrupled grafts were mounted in porcine femurs, placed in Ringer's solution for 12 h at 37 °C and graft displacement at the bone tunnel aperture recorded under cyclic loading. RESULTS: Mean decreases in CSA of 31% under a stress of 471 kPa and 21% under a stress of 447 kPa were observed for doubled and quadrupled grafts, respectively. Compressed grafts re-expanded by 19% over 12 h compared to 2% for controls. No significant differences were observed between compressed and control grafts in the biomechanical properties and graft stability; mean cyclic displacements were 0.3 mm for both groups. CONCLUSIONS: No detrimental biomechanical effects of graft compression on allograft PL tendons were observed. Following compression, the grafts significantly increased in size during in vitro joint simulation. No significant difference was observed in graft stability between groups. Graft compression did not cause adverse mechanical effects in vitro. Smaller tunnels for compressed grafts reduce bone loss and ease anatomical placement.
Date Issued
2018-08-01
Date Acceptance
2018-03-26
Citation
Knee Surgery, Sports Traumatology, Arthroscopy, 2018, 26 (8), pp.2430-2437
ISSN
0942-2056
Publisher
Springer Verlag
Start Page
2430
End Page
2437
Journal / Book Title
Knee Surgery, Sports Traumatology, Arthroscopy
Volume
26
Issue
8
Copyright Statement
© European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2018. The final publication is available at Springer via https://link.springer.com/article/10.1007%2Fs00167-018-4932-4
Sponsor
Imperial College Healthcare NHS Trust
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/29623378
PII: 10.1007/s00167-018-4932-4
Grant Number
None
Subjects
ACL reconstruction
Anterior cruciate ligament
Compression downsizing
Tendon graft biomechanics
Publication Status
Published
Coverage Spatial
Germany
Date Publish Online
2018-04-05