Impact of Tunnels and Tenodesis Screws on Clavicle Fracture: A Biomechanical Study of Varying Coracoclavicular Ligament Reconstruction Techniques
ABSTRACT The purpose of this study was to compare the load to fracture of distal clavicles with no tunnels, one tunnel, or 2 tunnels and to evaluate the effect of inserting tenodesis screws in the tunnels on load to fracture of the distal clavicle.
Fifty right sawbone clavicles were obtained and divided into 5 groups (n = 10): group 1, normal clavicle; group 2, one tunnel, no tenodesis screw; group 3, 2 tunnels, no tenodesis screws; group 4, one tunnel with tenodesis screw; and group 5, 2 tunnels with 2 tenodesis screws. Tunnels were created using a 5-mm-diameter reamer, and 5.5 × 10 mm polyethyl ethyl ketone tenodesis screws were used. A 4-point bending load was applied to the distal clavicles. Load to failure was noted for each specimen.
Load to failure in clavicles without tunnels was significantly higher (1,157.18 ± 147.10 N) than in all other groups (P < .0005). No statistical differences were noted between groups 2, 3, 4, and 5. Load to failure was not statistically different in clavicles with one versus 2 tunnels. In addition, the use of tenodesis screws in the tunnels did not affect the load required to fracture.
The use of tunnels in the clavicle for coracoclavicular (CC) ligament reconstruction significantly reduces the load required to fracture the distal clavicle. The addition of tenodesis screws does not appear to significantly increase the strength of the clavicle in this construct.
CC ligament reconstruction techniques commonly use tunnels in the distal clavicle, which may render the clavicle more susceptible to fracture. This study helps quantify the effect of these tunnels on the strength of the distal clavicle.
- [Show abstract] [Hide abstract]
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, 230.7%; range, 8.1% to 262.5%) than the CFB technique (mean, 23.8%; range, 34.2% to 228.1%; P = .031). The CFB technique was not significantly different from intact (P = .314). There was a significant correlation between clavicle width and strength reduction (t = 20.36, P = .04) and between relative tunnel size and strength reduction (t = 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.The American Journal of Sports Medicine 03/2014; 42(7). DOI:10.1177/0363546514524159 · 4.70 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Management strategies for acromioclavicular (AC) joint injuries depend heavily on the severity of the injury. Operative treatment is typically indicated for Rockwood grades IV-VI injuries and selected grade III injuries, especially after failure of nonoperative management. When surgical treatment is indicated, we prefer to reconstruct the unstable AC joint using an anatomic coracoclavicular ligament reconstruction (ACCR) technique with tendon graft looped around both the coracoid and the clavicle. The purpose of this article is to present the biomechanical rationale, our detailed surgical technique and reported clinical outcomes for ACCR with tendon graft.Operative Techniques in Sports Medicine 09/2014; 22(3). DOI:10.1053/j.otsm.2013.10.009 · 0.21 Impact Factor