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Distal biceps tendon ruptures are thought to be secondary to an acute forceful eccentric load on a degenerative tendon. Nonoperative treatment following rupture leads to significantly decreased forearm supination and elbow flexion strength. There are several techniques described in the literature for repair. This article describes, with video illustration, distal biceps tendon repair using a double tension slide technique with 2 No. 2 high-tension nonabsorbable composite sutures.

Push-out tests are frequently used to evaluate the bone-implant interfacial strength of orthopedic implants, particularly dental and craniomaxillofacial applications. There currently is no standard method for performing push-out tests on calvarial models, leading to a variety of inconsistent approaches. In this study, fixtures and methods were developed to perform push-out tests in accordance with the following design objectives: (i) the system rigidly fixes the explanted calvarial sample, (ii) it minimizes lateral bending, (iii) it positions the defect accurately, and (iv) it permits verification of the coaxial alignment of the defect with the push-out rod. The fixture and method was first validated by completing push-out experiments on 30 explanted murine cranial caps and two explanted leporine cranial caps, all induced with bilateral sub-critical defects (5.0 mm and 8.0 mm nominal diameter for the murine and leporine models, respectively). Defects were treated with an autograft (i.e., excised tissue flap), a shape memory polymer (SMP) scaffold, or a PEEK implant. Additional validation was performed on 24 murine cranial caps induced with a single, unilateral critically-sized defect (8.0 mm nominal diameter) and treated with an autograft or a SMP scaffold. A novel fixture was developed for performing push-out mechanical tests to characterize the strength of a bone-implant interface in calvarial defect repair. The fixture uses a 3D printed vertical clamp with mating alignment component to fix the sample in place without inducing lateral bending and verify coaxial alignment of push-out rod with the defect. The fixture can be scaled to different calvarial defect geometries as validated with 5.0 mm bilateral and 8.0 mm single diameter murine calvarial defect model and 8.0 mm bilateral leporine calvarial defect model.

Background A comparative biomechanical analysis of two distal biceps tendon repair techniques was performed: a single suture tension slide technique (TST) and two suture double tension slide (DTS) technique. Methodology Ten matched pairs of fresh frozen human cadaveric elbows (20 elbows) were randomly separated into two cohorts for distal biceps tendon repair. One cohort underwent the TST, and the other underwent the DTS technique. The tendon was preconditioned with cyclic loading from 0° to 90° at 0.5 Hz for 3,600 cycles with a 50 N load. The specimens were then loaded to failure at a rate of 1 mm/s. The difference in the load to failure between the groups was analyzed using the Student’s t test. The mode of failure was compared between groups using the chi-square test. All p-values were reported with significance set at p < 0.05. Results Overall, 77.8% of the included matched pairs demonstrated greater load to failure in the DTS group. The mean load to failure in the DTS group was 383.3 ± 149.3 N compared to 275.8 ± 98.1 N in the TST group (p = 0.13). The DTS specimens failed at the tendon (5/9), suture (3/9), and bone (1/9). The TST specimens failed at the tendon (4/9) and suture (5/9) only. There was no significant difference in failure type between groups (p = 0.76). Conclusions DTS demonstrates a similar to greater load to failure compared to TST with a trend towards statistical significance. The redundancy provided by the second suture has an inherent advantage without compromising the biomechanical testing.