Open Biceps Tenodesis: A Biomechanical Comparison of 6 Fixation Techniques.

Tenodesis is used to treat pathology of the long head of the biceps tendon. The authors evaluated the biomechanical properties of 6 techniques for biceps tenodesis fixation. The authors dissected 42 fresh-frozen cadaveric shoulders (mean age, 71±9.8 years; 69% male specimens), leaving the proximal humerus, proximal biceps tendon, and pectoralis major insertion. Specimens were randomized to undergo biceps tenodesis with one of the following: (1) an interference screw; (2) a cortical button; (3) a double-loaded 2.9-mm polyetheretherketone anchor (DL-2.9); (4) a double-loaded 1.9-mm all-suture anchor (DL-1.9); (5) a single-loaded 1.7-mm all-suture anchor (SL-1.7); or (6) soft tissue tenodesis. Specimens then underwent load-to-failure axial traction testing. A generalized linear and latent mixed model with a random-effects term was used to account for specimen pairing. Mean failure loads ranged from 136 N (95% confidence interval, 103-169 N) in the cortical button group to 79 N (95% confidence interval, 58-99 N) in the interference screw group. Failure occurred most often when fixation sutures pulled out of the tendon; however, 7 specimens failed elsewhere. No significant differences in ultimate failure load were found by treatment group. The interference screw group showed significantly more weakness than the cortical button and DL-2.9 groups. Tendon quality and suture parameters are likely more important than the fixation technique in determining failure load. [Orthopedics. 2020;43(2):e102-e108.].

Biomechanical Strength of Rotator Cuff Repairs: A Systematic Review and Meta-regression Analysis of Cadaveric Studies.

BACKGROUND: Biomechanical cadaveric studies of rotator cuff repair (RCR) have shown that transosseous equivalent and double-row anchored repairs are stronger than other repair constructs. PURPOSE: To identify technical and procedural parameters that most reliably predict biomechanical performance of RCR constructs. STUDY DESIGN: Systematic review. METHODS: The authors systematically searched the EMBASE and PubMed databases for biomechanical studies that measured RCR performance in cadaveric specimens. The authors performed a meta-regression on the pooled data set with study outcomes (gap formation, failure mode, and ultimate failure load) as dependent variables and procedural parameters (eg, construct type, number of suture limbs) as covariates. Stratification by covariates was performed. An alpha level of .05 was used. RESULTS: Data from 40 eligible studies were included. Higher number of suture limbs correlated with higher ultimate failure load (ß = 38 N per limb; 95% CI, 28 to 49 N) and less gap formation (ß = -0.6 mm per limb; 95% CI, -1 to -0.2 mm). Other positive predictors of ultimate failure load were number of sutures, number of mattress stitches, and use of wide suture versus standard suture. When controlling for number of suture limbs, we found no significant differences among single-row anchored, double-row anchored, transosseous equivalent, and transosseous repairs. Higher number of suture limbs and transosseous equivalent repair both increased the probability of catastrophic construct failure. CONCLUSION: This study suggests that the number of sutures, suture limbs, and mattress stitches in a RCR construct are stronger predictors of overall strength than is construct type. There is a need to balance increased construct strength with higher risk of type 2 failure.