Synthetic coracoclavicular ligament vs. coracoclavicular suspensory construct for treatment of acromioclavicular dislocation: a biomechanical study.
Synthetic coracoclavicular ligament vs. coracoclavicular suspensory construct for treatment of acromioclavicular dislocation: a biomechanical study.
- 2020
BACKGROUND: A synthetic ligament (LockDown, Worcestershire, England) has become available to treat complete acromioclavicular dislocation with promising clinical results and potential benefit to avoid postoperative loss of reduction. We investigated the biomechanics of this synthetic ligament in a simulated immediate postoperative rehabilitation setting, hypothesizing that the synthetic ligament would demonstrate less superior coracoclavicular displacement to cyclic loading and higher ultimate load-to-failure values than a coracoclavicular suspensory construct. CONCLUSION: In a simulated immediate postoperative cadaveric model, the synthetic ligament demonstrated poorer biomechanics than the coracoclavicular suspensory construct. These findings suggest that a coracoclavicular suspensory construct may be preferable to a synthetic ligament if early rehabilitation is intended. Copyright (c) 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved. METHODS: Seven matched-pair cadaveric shoulders (mean age at time of death, 79 years) were loaded cyclically and to failure. One specimen in each pair was randomly assigned to the synthetic ligament or coracoclavicular suspensory construct. Superiorly directed 70-N cyclic loading for 3000 cycles at 1.0 Hz was applied through the clavicle in a fixed scapula simulating physiologic states during immediate postoperative rehabilitation, followed by a load-to-failure test at 120 mm/min. RESULTS: After 3000 cycles, the superior displacement of the clavicle in the synthetic ligament (9.2 +/- 1.1 mm) was 225% greater than in the coracoclavicular suspensory construct (2.8 +/- 0.4 mm, 95% confidence interval [CI] 3.4, 8.3; P < .001). Average stiffness of the synthetic ligament (32.8 N/mm) was 60% lower than that of the coracoclavicular suspensory construct (81.9 N/mm, 95% CI 43.3, 54.9; P < .001). Ultimate load-to-failure of the synthetic ligament was 23% (95% CI 37.9, 301.5; P = .016) lower than the coracoclavicular suspensory construct (580.5 +/- 85.1 N and 750.2 +/- 135.5 N, respectively).
English
1058-2746
10.1016/j.jse.2019.11.017 [doi] S1058-2746(19)30796-7 [pii]
*Acromioclavicular Joint/in [Injuries]
*Acromioclavicular Joint/su [Surgery]
*Joint Dislocations/su [Surgery]
*Ligaments, Articular/in [Injuries]
*Ligaments, Articular/su [Surgery]
*Reconstructive Surgical Procedures
Aged
Biomechanical Phenomena
Cadaver
Clavicle/su [Surgery]
Female
Humans
Male
Range of Motion, Articular
Scapula/su [Surgery]
Shoulder/su [Surgery]
Weight-Bearing
Curtis National Hand Center
MedStar Union Memorial Hospital
Orthopaedic Surgery
Journal Article
BACKGROUND: A synthetic ligament (LockDown, Worcestershire, England) has become available to treat complete acromioclavicular dislocation with promising clinical results and potential benefit to avoid postoperative loss of reduction. We investigated the biomechanics of this synthetic ligament in a simulated immediate postoperative rehabilitation setting, hypothesizing that the synthetic ligament would demonstrate less superior coracoclavicular displacement to cyclic loading and higher ultimate load-to-failure values than a coracoclavicular suspensory construct. CONCLUSION: In a simulated immediate postoperative cadaveric model, the synthetic ligament demonstrated poorer biomechanics than the coracoclavicular suspensory construct. These findings suggest that a coracoclavicular suspensory construct may be preferable to a synthetic ligament if early rehabilitation is intended. Copyright (c) 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved. METHODS: Seven matched-pair cadaveric shoulders (mean age at time of death, 79 years) were loaded cyclically and to failure. One specimen in each pair was randomly assigned to the synthetic ligament or coracoclavicular suspensory construct. Superiorly directed 70-N cyclic loading for 3000 cycles at 1.0 Hz was applied through the clavicle in a fixed scapula simulating physiologic states during immediate postoperative rehabilitation, followed by a load-to-failure test at 120 mm/min. RESULTS: After 3000 cycles, the superior displacement of the clavicle in the synthetic ligament (9.2 +/- 1.1 mm) was 225% greater than in the coracoclavicular suspensory construct (2.8 +/- 0.4 mm, 95% confidence interval [CI] 3.4, 8.3; P < .001). Average stiffness of the synthetic ligament (32.8 N/mm) was 60% lower than that of the coracoclavicular suspensory construct (81.9 N/mm, 95% CI 43.3, 54.9; P < .001). Ultimate load-to-failure of the synthetic ligament was 23% (95% CI 37.9, 301.5; P = .016) lower than the coracoclavicular suspensory construct (580.5 +/- 85.1 N and 750.2 +/- 135.5 N, respectively).
English
1058-2746
10.1016/j.jse.2019.11.017 [doi] S1058-2746(19)30796-7 [pii]
*Acromioclavicular Joint/in [Injuries]
*Acromioclavicular Joint/su [Surgery]
*Joint Dislocations/su [Surgery]
*Ligaments, Articular/in [Injuries]
*Ligaments, Articular/su [Surgery]
*Reconstructive Surgical Procedures
Aged
Biomechanical Phenomena
Cadaver
Clavicle/su [Surgery]
Female
Humans
Male
Range of Motion, Articular
Scapula/su [Surgery]
Shoulder/su [Surgery]
Weight-Bearing
Curtis National Hand Center
MedStar Union Memorial Hospital
Orthopaedic Surgery
Journal Article