Biomechanical Consequences of Coracoclavicular Reconstruction Techniques on Clavicle Strength

Ulrich J Spiegl; Sean D Smith; Simon A Euler; Grant J Dornan; Peter J Millett; Coen A Wijdicks

doi:10.1177/0363546514524159

Biomechanical Consequences of Coracoclavicular Reconstruction Techniques on Clavicle Strength

Am J Sports Med. 2014 Jul;42(7):1724-30. doi: 10.1177/0363546514524159. Epub 2014 Mar 13.

Authors

Ulrich J Spiegl¹, Sean D Smith², Simon A Euler³, Grant J Dornan², Peter J Millett⁴, Coen A Wijdicks⁵

Affiliations

¹ Steadman Philippon Research Institute, Vail, Colorado, USA Department of Trauma and Reconstructive Surgery, University of Leipzig, Leipzig, Germany.
² Steadman Philippon Research Institute, Vail, Colorado, USA.
³ Steadman Philippon Research Institute, Vail, Colorado, USA Department of Trauma Surgery and Sports Medicine, Medical University Innsbruck, Innsbruck, Austria.
⁴ Steadman Philippon Research Institute, Vail, Colorado, USA The Steadman Clinic, Vail, Colorado, USA.
⁵ Steadman Philippon Research Institute, Vail, Colorado, USA cwijdicks@sprivail.org.

PMID: 24627576
DOI: 10.1177/0363546514524159

Abstract

Background: Lateral clavicle fractures have been reported after coracoclavicular (CC) ligament reconstructions with bone tunnels through the clavicle.

Purpose: To biomechanically compare clavicle strength following 2 common CC reconstruction techniques with different bone tunnel diameters.

Study design: Controlled laboratory study.

Methods: Testing was performed on 2 groups of matched-pair cadaveric clavicles. Clavicles were prepared with either 2.4-mm tunnels and cortical fixation button (CFB) devices or 6.0-mm tunnels with hamstring tendon grafts (TGs) and tenodesis screws; contralateral clavicles were left intact. A 3-point bending load was applied to the distal clavicles at a rate of 15 mm/min until failure. Ultimate failure load and anterior-posterior width of the clavicles 45 mm medial from the lateral border were recorded. Strength reduction was determined as the percentage reduction in ultimate failure load between paired intact and surgically prepared clavicles. Relative tunnel size was determined as the quotient of tunnel diameter and clavicle width, reported as a percentage.

Results: The TG technique significantly reduced clavicle strength relative to intact (P = .011) and caused significantly more strength reduction (mean, -30.7%; range, 8.1% to -62.5%) than the CFB technique (mean, -3.8%; range, 34.2% to -28.1%; P = .031). The CFB technique was not significantly different from intact (P = .314). There was a significant correlation between clavicle width and strength reduction (τ = -0.36, P = .04) and between relative tunnel size and strength reduction (τ = 0.51, P = .005).

Conclusion: The TG reconstruction technique with 6.0-mm tunnels, grafts, and tenodesis screws caused significantly more reduction of clavicle strength compared with the CFB technique with 2.4-mm tunnels and CFB device. Additionally, relative tunnel width correlated highly with the strength reduction.

Clinical relevance: This information can influence intraoperative decision making based on the individual clavicle width and might influence postoperative treatment protocols. Large bone tunnels may predispose patients to clavicle fractures after anatomic CC reconstructions.

Keywords: acromioclavicular dislocation; clavicle strength; clavicle width; coracoclavicular ligament reconstruction; tunnel size.

MeSH terms

Acromioclavicular Joint / surgery*
Arthroplasty / methods
Cadaver
Clavicle / surgery*
Fractures, Bone / surgery*
Humans
Joint Dislocations / surgery*
Ligaments, Articular / surgery*
Plastic Surgery Procedures / methods
Scapula / surgery