Biomechanical properties of suprapectoral biceps tenodesis: double knotless screw fixation is superior to single knotless screw fixation

A Systematic Review and Meta-analysis of Biceps Tenodesis Fixation Strengths: Fixation Type and Location Are Biomechanically Equivalent

PURPOSE

The purpose of this meta-analysis and systematic review was to critically evaluate the biomechanical outcomes of different fixation constructs for a variety of biceps tenodesis techniques in cadaveric models based on both type of fixation and location.

METHODS

A PROSPERO-registered systematic review (CCRD42018109243) of the current literature was conducted with the terms "long head of biceps" AND "tenodesis" AND "biomechanics" and numerous variations thereof in the PubMed, Embase, and Cochrane databases, yielding 1,460 abstracts. After screening by eligibility criteria, 18 full-text articles were included. The individual biomechanical factors evaluated included ultimate load to failure (in newtons), stiffness (in newtons per millimeter), and cyclic displacement (in millimeters). After reviewing the included literature, we performed a quality analysis of the studies (Quality Appraisal for Cadaveric Studies scale score) and a meta-analysis comparing raw mean differences in data between the suprapectoral and subpectoral fixation location groups, as well as between the fixation construct groups.

RESULTS

Among the 18 included studies, 347 cadaveric specimens were evaluated for ultimate load to failure, stiffness, and cyclic displacement when comparing both location (suprapectoral vs subpectoral) and tenodesis fixation type (interference screw vs cortical button, suture anchor, or all-soft-tissue techniques). Interference screw fixation showed significantly greater mean stiffness by 8.0 N/mm (P = .013) compared with the other grouped techniques but did not show significant differences when evaluated for ultimate load to failure and cyclic displacement (P = .28 and P = .18, respectively). Additionally, no difference in construct strength was seen when comparing the fixation strength of suprapectoral versus subpectoral techniques for stiffness, ultimate load to failure, and cyclic loading (P = .47, P = .053, and P = .13, respectively).

CONCLUSIONS

In this meta-analysis, no significant biomechanical differences were found when the results were stratified by specific surgical technique (interference screw vs other tenodesis techniques) and location (suprapectoral vs subpectoral biceps tenodesis).

CLINICAL RELEVANCE

As a result of this study, when biomechanically evaluating specific tenodesis constructs, the individual clinician has the liberty of choosing the fixation technique based on his or her preference and knowledge of shortcomings of each type of fixation construct.

High-Tensile Strength Tapes Show Greater Ultimate Failure Load and Less Stiffness Than High-Tensile Strength Sutures in a Subpectoral Biceps Tenodesis Porcine Model

Purpose

To compare the biomechanical properties of high-tensile strength tape and a high-tensile strength suture in subpectoral biceps tenodesis using a suture anchor in a porcine tendon model.

Methods

A total of 24 artificial composite (polymer and glass fiber) humeri and porcine flexor profundus tendons were used. Two types of suture materials, high-tensile strength sutures (group S) and high-tensile strength tapes (group T), were evaluated. After we inserted metallic suture anchors with either 2 sutures or tapes 5 cm from the superomedial corner of the greater tuberosity, a Krackow suture technique was used to secure the tendons. After a preload of 5 N for 2 minutes, a cyclic loading test from 5 to 70 N was conducted for 500 cycles. Finally, the specimen was loaded to failure at a rate of 1 mm/s.

Results

There were no significant between-group differences in elongation after cyclic loading and elongation at failure load for group S and group T (P = .977 and .630, respectively). The ultimate failure loads in group T (278.2 ± 54 N) were significantly greater than those in group S (249.4 ± 32 N) (P = .028). In contrast, the stiffness values in group T (28.5 ± 4.0 N/mm) were significantly lower than those in group S (32.3 ± 4.5 N) (P = .028). Ten specimens in group S and 8 specimens in group T failed, with tendons being cut through by the sutures, whereas the other 2 specimens in group S and 4 specimens in group T failed due to suture breakage.

Conclusions

Using high-tensile strength tapes in subpectoral biceps tenodesis using a suture anchor leads to significantly greater ultimate failure load as compared with using high-tensile strength sutures in a porcine model. Although lower levels of stiffness were found in high-tensile strength tape group, the difference in the means were not large between 2 groups.

Clinical Relevance

A strong suture–tendon structure may prevent clinical failure of a subpectoral biceps tenodesis using a suture anchor.

Using Interconnected Knotless Anchor for Suprapectoral Biceps Tenodesis Could Offer Improved Biomechanical Properties in a Cadaveric Model

PURPOSE

To compare the biomechanical characteristics of the interconnected knotless anchor (IKA) fixation with the double knotless anchor (DKA) and interference screw (IS) fixation in the suprapectoral biceps tenodesis.

METHODS

In total, 24 fresh-frozen human cadaveric shoulders (mean age, 67.3 ± 6 years) were used for the study. All the specimens were randomly divided into 3 experimental biceps tenodesis groups (n = 8): IKA, DKA, and IS. After tenodesis, each specimen was preloaded at 5 N for 2 minutes, followed by a cyclic loading test from 5 to 70 N for 500 load cycles. Finally, a destructive axial load to failure test (1 mm/s) was performed. All the values, including ultimate failure load, stiffness, cyclic displacement, and mode of failure were evaluated.

RESULTS

The IKA provided the highest construct stiffness (38.9 ± 7.7 N/mm) and ultimate failure load (288.3 ± 47.6 N), the results for which were statistically better than the corresponding results in the IS and DKA groups. In terms of cyclic displacement, there were no statistical differences among the 3 fixation constructs. The most common failure mode was biceps tendon tearing in IS group (7/8) and IKA group (8/8). In the contrast, suture slippage accounted for the most common failure mode in DKA.

CONCLUSIONS

In suprapectoral bicep tenodesis, IKA fixation appears to offer improved construct stiffness and ultimate failure load while maintaining comparable suture slippage as compared with IS fixation or DKA fixation in the current biomechanical study.

CLINICAL RELEVANCE

The IKA fixation compares favorably with other techniques and could be an alternative clinical option for suprapectoral biceps tenodesis.

Are Implant Choice and Surgical Approach Associated With Biceps Tenodesis Construct Strength? A Systematic Review and Meta-regression

BACKGROUND

Despite the increasing use of biceps tenodesis, there is a lack of consensus regarding optimal implant choice (suture anchor vs interference screw) and implant placement (suprapectoral vs subpectoral).

PURPOSE/HYPOTHESIS

The purpose was to determine the associations of procedural parameters with the biomechanical performance of biceps tenodesis constructs. The authors hypothesized that ultimate failure load (UFL) would not differ between sub- and suprapectoral repairs or between interference screw and suture anchor constructs and that the number of implants and number of sutures would be positively associated with construct strength.

STUDY DESIGN

Meta-analysis.

METHODS

The authors conducted a systematic literature search for studies that measured the biomechanical performance of biceps tenodesis repairs in human cadaveric specimens. Two independent reviewers extracted data from studies that met the inclusion criteria. Meta-regression was then performed on the pooled data set. Outcome variables were UFL and mode of failure. Procedural parameters (fixation type, fixation site, implant diameter, and numbers of implants and sutures used) were included as covariates. Twenty-five biomechanical studies, representing 494 cadaveric specimens, met the inclusion criteria.

RESULTS

The use of interference screws (vs suture anchors) was associated with a mean 86 N-greater UFL (95% CI, 34-138 N; P = .002). Each additional suture used to attach the tendon to the implant was associated with a mean 53 N-greater UFL (95% CI, 24-81 N; P = .001). Multivariate analysis found no significant association between fixation site and UFL. Finally, the use of suture anchors and fewer number of sutures were both independently associated with lower odds of native tissue failure as opposed to implant pullout.

CONCLUSION

These findings suggest that fixation with interference screws, rather than suture anchors, and the use of more sutures are associated with greater biceps tenodesis strength, as well as higher odds of native tissue failure versus implant pullout. Although constructs with suture anchors show inferior UFL compared with those with interference screws, incorporation of additional sutures may increase the strength of suture anchor constructs. Supra- and subpectoral repairs provide equivalent biomechanical strength when controlling for potential confounders.

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.].

Biceps tenodesis versus tenotomy in isolated LHB lesions: a prospective randomized clinical trial

INTRODUCTION

Currently there exists no clear evidence concerning the surgical treatment of LHB lesions with either tenotomy or tenodesis. The aim of the study is therefore to evaluate elbow flexion and forearm supination force as well as the biceps muscle distalization according to both techniques in isolated LHB lesions.

METHODS

Consecutive patients aged 40-70 years with shoulder arthroscopies for isolated SLAP or biceps pulley lesions were prospectively randomized to arthroscopic suprapectoral intraosseous LHB tenodesis or tenotomy. Pre-, 6 and 12 months postoperatively, the SST, ASES, Constant-Murley and LHB scores were recorded. The elbow flexion force was measured in 10°/90° flexion, the supination force in neutral/pronation position. In addition, the maximum upper-arm circumference and its position relative to the radial epicondyle of the humerus were evaluated preoperatively and in follow-up.

RESULTS

20/22 patients (mean age 52.0 ± 8.5; range 36-63 years, 11 male) completed the follow-up. 9/20 were treated with LHB tenodesis (mean age 51.5 ± 9.5; range 37-63 years, 7 male) and 11/20 with tenotomy (mean age 52.8 ± 8.0; range 36-62 years, 4 male). The force measurements and scores showed no significant difference after 12 months. Tenodesis achieved a significant increase in force 6 months postoperatively compared to preoperatively. One tenodesis patient and three tenotomy patients showed a postoperative popeye-sign deformity.

CONCLUSION

This prospective randomized study comparing LHB tenodesis and tenotomy in isolated LHB lesions has shown no significant difference in elbow flexion and forearm supination force and clinical scores after 12 months. After LHB tenotomy, there was a non-significant trend for a higher rate of popeye-sign deformities of the upper arm and biceps muscle cramps.