Biomechanical Evaluation of Humerus Fracture After Subpectoral Biceps Tenodesis With Interference Screw Versus Unicortical Button

Unicortical button fixation provides higher strength compared with transosseous repair for subscapularis tendon in total shoulder arthroplasty

BACKGROUND

Subscapularis tendon (SSc) dysfunction after total shoulder arthroplasty (TSA) results in poor functional outcomes. There have been numerous SSc repair constructs tested biomechanically and clinically; however, none has been demonstrated as superior. Newer techniques and implants have emerged but have not been fully tested.

HYPOTHESIS

We hypothesized that the unicortical button (UB) fixation would provide significantly improved restoration of the anatomic footprint and biomechanical properties compared with transosseous (TO) repair of the SSc.

METHODS

A digital footprint of SSc humeral insertion was obtained in 6 pairs of fresh-frozen cadaveric shoulders using a 3-dimensional digitizer. A complete SSc tear was created, and each pair of shoulders was randomized to either SSc repair with UB or TO repair. Each specimen underwent a cyclic loading protocol, followed by pull to failure. The failure load, elongation at failure, gapping failure, number of cycles until failure, the load at key gapping points (1 mm, 3 mm, 5 mm, and 10 mm), and the failure mode were recorded using high-resolution video recording. Three-dimensional surfaces of the insertion footprint and repair site were obtained, and surface areas were calculated using a custom MATLAB script and laser scanner. Paired t tests were conducted to compare differences between the 2 repair groups.

RESULTS

Failure load was significantly higher in the UB group (382.4 N ± 56.5 N) than in the TO group (253.6 N ± 103.4 N, P = .005). TO repair provided higher gapping at failure (28.8 mm ± 8.2 mm) than UB repair (10.4 mm ± 6.8 mm, P = .0017). UB repair had significantly higher load at the 1-mm, 5-mm, and 10-mm gapping than TO repair, with P = .042, P = .033, and P = .0076, respectively. There were no significant differences in elongation failure, the difference in footprint area from native to repair states, or the percentage of the restored footprint area between the groups (P = .26, P = .18, and P = .21, respectively).

CONCLUSIONS

The UB fixation showed a significantly lower gap at failure, higher failure load and number of cycles until failure, and higher gap loads than the traditional TO repair for SSc. Although more clinical research is necessary, the UB fixation that uses cortical bone presents promising results.

Arthroscopic Inlay Biceps Tenodesis Using a Tendon-Docking Anchor

Pathology of the long head of the biceps tendon can be treated surgically with a multitude of tenodesis techniques; however, there is a lack of consensus on which technique provides the most optimal outcomes. Commonly used methods include inlay tenodesis with a bone tunnel and interference screw construct and onlay tenodesis with anchors or unicortical buttons. Although current methods typically provide satisfactory outcomes, many surgeons believe complications and failure rates remain suboptimal across techniques. In this article, we present an arthroscopic suprapectoral biceps tenodesis technique using an anchor device that was developed to address the shortcomings of current techniques, optimize outcomes, and minimize risk.

Biomechanical comparisons of all--suture suspensory button vs. interference screw for inlay subpectoral bicep tenodesis

BACKGROUND

All-suture buttons (ASBs) and interference screw (IS) are commonly utilized in the inlay subpectoral biceps tendon tenodesis. However, the biomechanical characteristics of these two methods have not been compared directly. The aim of present study was to compare the biomechanical properties of ASB vs. IS for inlay subpectoral biceps tendon tenodesis in a human cadaveric model.

METHODS

Sixteen fresh-frozen human cadaveric shoulders were randomly divided into two experimental inlay biceps tenodesis groups: ASB or IS. After tenodesis, every specimen was preloaded at 5 N for 2 minutes, followed with a cyclic loading test from 5 to 70 N for 500 load cycles. Then the load-to-failure test was performed. Afterward, the humerus was placed in a cylinder tube and secured with anchoring cement. Lastly, a two-point bending test was performed to determine the strength of the humerus. Destructive axial force was applied, and the failure strength and displacement were recorded.

RESULTS

No difference in stiffness was observed between the two groups (ASB = 27.4 ± 3.5 N/mm vs. IS = 29.7 ± 3.0 N/mm; P = .270). Cyclic displacement was significantly greater in the ASB group (6.8 ± 2.6 mm) than the IS group (3.8 ± 1.1 mm; P = .021). In terms of failure load, there were no statistical differences among the two groups (P = .234). The ASB group was able to withstand significantly greater displacement (11.9 ± 1.6 mm) before failure than the IS group (7.8 ± 1.5 mm; P = .001). During the humeral bending test, the ASB group exhibited significantly greater maximal load (2354.8 ± 285.1 N vs. 2086.4 ± 296.1 N; P = .046) and larger displacement (17.8 ± 2.8 mm vs. 14.1 ± 2.8 mm; P = .027) before fracture.

CONCLUSIONS

In inlay subpectoral bicep tenodesis, ASB fixation appears to offer comparable stiffness and failure load to that of IS fixation. Additionally, the ASB group exhibited greater resistance to load and displacement before humeral fracture. However, the ASB group did demonstrate increased cyclic displacement compared to IS group.

Comparison of clinical outcomes and return to sport between unicortical versus bicortical button fixation techniques for subpectoral biceps tenodesis

PURPOSE

There is limited clinical outcome data comparing fixation methods for tenodesis of the long head of the biceps tendon (LHBT), particularly button fixation. The purpose of this study was to compare clinical outcomes, patient-reported outcomes, and return to sport (RTS) between patients undergoing LHBT with bicortical versus unicortical button technique. The authors hypothesized these fixation methods would be similar for all outcomes.

METHODS

Patients who underwent LHBT using unicortical or bicortical button fixation with minimum 2-year follow-up were identified. Postoperative outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) questionnaire and visual analogue scale (VAS) pain score. A sports activity survey was collected to assess baseline sport participation and ability to return to pre-injury activities. Continuous variables were analyzed using the Mann-Whitney-U test. Categorical variables were analyzed using Chi-squared tests. Multivariable logistic and linear regression were performed to determine predictors of RTS and time to RTS.

RESULTS

Sixty-four subjects (19 unicortical and 45 bicortical button fixation) were included (average follow-up 3.5 (range: 2.0-7.8) years). There were no significant differences found between button groups for VAS pain score (1.5 vs. 1.2; p = 0.876), VAS pain during sport score (1.6 vs. 1.1, p = 0.398), and ASES score (66 vs. 71; p = 0.294). There were no significant differences in rate of RTS (75.0 vs. 77.4%; p = 0.885) or average time to return to sport (11.7 ± 7.3 vs. 7.0 ± 4.0 months; p = 0.081) between groups.

CONCLUSION

There were no significant differences in clinical outcomes, pain, or return to sport between patients who underwent LHBT with unicortical or bicortical button fixation.

Proximal Biceps Tenodesis - Biomechanical Analysis in Sheep: Comparison between Metallic Anchor, Onlay Bioabsorbable Knotless Anchor, and Interference Screw

Objective  To biomechanically evaluate different fixation devices for the proximal biceps in the humerus of sheep, comparing their fixation strength to failure, tendon displacement, and failure site in each technique. Methods  A total of 27 humerus tests were performed on sheep, separating them into 3 groups: group A with tenodesis with metallic anchors ( n  = 11), group B with biocomposite knotless devices ( n  = 8) and group C with metallic interference screws ( n  = 8), performing tenodesis with the sheep's own biceps, maintaining its native distal insertion. The three methods were submitted to a universal tensile testing machine. Results  There was no statistically significant difference in the strength of fixation until failure and displacement between the tendons fixed by the different techniques. Regarding the pattern of ruptures, it was observed that most ruptures of the metallic anchors occurred at the level of the myotendinous junction, most of the bioabsorbable knotless anchors failed due to slippage of the wire-screw interface, and all interference screws failed via tendon slip. Conclusion  The three techniques with metal anchor, onlay bioabsorbable knotless anchors, and interference screws are largely resistant to tensile loads for long head of the biceps tenodesis in sheep. There was no statistical difference between the three groups. Cyclic load resistance studies can provide more valuable data for comparing groups.

Long-term patient-reported outcomes of open subpectoral biceps tenodesis with cortical button fixation

BACKGROUND

Open subpectoral biceps tenodesis (OSBT) with cortical button fixation has been shown to deliver acceptable results in the short and intermediate term for long head of the biceps (LHB) pathology with the benefit of smaller bone tunnel diameter and a reduced risk of postoperative humeral shaft fracture. The primary purpose of this study was to determine whether OSBT with cortical button fixation results in significant improvements in patient reported outcomes (PROs) from pre-operative to long-term final follow-up.

METHODS

A retrospective analysis of patients who underwent OSBT with cortical button fixation at a single institution between the years of 2012 and 2014 was conducted and PROs were collected in the intermediate (> 2 years follow-up) and long term (> 9 years follow-up). PROs were measured pre-operatively, at intermediate follow-up, and at long-term follow-up using three validated questionnaires: American Shoulder and Elbow Surgeons (ASES) score, Disabilities of the Arm, Shoulder, and Hand (DASH) score, and Oxford Shoulder Score (OSS). Patients were additionally asked at final follow-up if they would undergo the same procedure again if they needed it.

RESULTS

Twenty-nine (29) patients with a mean age of 51.16 ± 9.06 years at the time of surgery were included in the study at final follow-up. Mean final follow-up time was 10.2 ± 0.5 years (range: 9.2-11.1 years). All PROs (ASES, OSS, and DASH) demonstrated statistically significant improvements from pre-operative to final follow-up with p < 0.01 for each. The proportions of patients exceeding established values for minimum clinically important difference (MCID) were 96.55%, 93.10%, and 75.86% for ASES, OSS, and DASH respectively. Only one patient had required re-operation as of final follow-up. None experienced humeral fractures post-operatively. A significant majority (89.66%; p < 0.01) of patients reported that they would undergo the same procedure again if they needed it. Fifty-three (53) patients were included in the study at intermediate follow-up with a mean follow-up time of 3.5 ± 1.4 years (range: 2-5.3 years). There were no statistically significant differences in any of the PRO measures from intermediate to long-term follow-up.

CONCLUSION

This study reported a minimum 9-year follow-up of patients undergoing OSBT with cortical button fixation for the management of LHBT pathology in the setting of concomitant shoulder procedures. All patients had significantly improved functional outcomes assessed with ASES, OSS, and DASH and no obvious differences in median group scores were found between patients assessed at intermediate (mean 3.5 years) and final (mean 10.2 years) follow-up. No infections, fractures, or fixation failures were reported.

Onlay Versus Inlay Biceps Tenodesis for Long Head of Biceps Tendinopathy: A Systematic Review and Meta-analysis

INTRODUCTION

Proximal biceps tenodesis is a common surgical treatment of tendinosis of the long head of the biceps tendon. Two of the most common techniques incorporate onlay and inlay fixation methods, which can be done arthroscopically or open and in a variety of anatomic locations. The purpose of this meta-analysis was to compare the clinical outcomes between onlay versus inlay humeral fixation for biceps tenodesis for long head of the biceps tendon pathology.

METHODS

A literature search was conducted using PubMed, EMBASE, and Cochrane Library. Only studies reporting outcomes and complications after onlay and inlay biceps tenodeses were included.

RESULTS

Six studies with a total of 418 patients (252 onlay, 166 inlay) with a mean age of 56.84 years were included. Visual analog pain scale scores, Constant score, and American Shoulder and Elbow Surgeons shoulder score did not differ. "Popeye" deformity was found in 17 patients (7.80%) in the onlay group and in 15 patients (11.28%) in the inlay group (odds ratio, 0.28; P = 0.07). No difference in postoperative cramping or failure rates was found.

CONCLUSION

Both onlay and inlay biceps tenodeses result in improved clinical outcomes and are at low risk of Popeye deformities, with no statistically significant differences between either method. Additional studies are required to assess the clinical significance of these differences.

Management of proximal biceps tendon pathology

The long head of the biceps tendon is widely recognized as an important pain generator, especially in anterior shoulder pain and dysfunction with athletes and working individuals. The purpose of this review is to provide a current understanding of the long head of the biceps tendon anatomy and its surrounding structures, function, and relevant clinical information such as evaluation, treatment options, and complications in hopes of helping orthopaedic surgeons counsel their patients. An understanding of the long head of the biceps tendon anatomy and its surrounding structures is helpful to determine normal function as well as pathologic injuries that stem proximally. The biceps-labral complex has been identified and broken down into different regions that can further enhance a physician’s knowledge of common anterior shoulder pain etiologies. Although various physical examination maneuvers exist meant to localize the anterior shoulder pain, the lack of specificity requires orthopaedic surgeons to rely on patient history, advanced imaging, and diagnostic injections in order to determine the patient’s next steps. Nonsurgical treatment options such as anti-inflammatory medications, physical therapy, and ultrasound-guided corticosteroid injections should be utilized before entertaining surgical treatment options. If surgery is needed, the three options include biceps tenotomy, biceps tenodesis, or superior labrum anterior to posterior repair. Specifically for biceps tenodesis, recent studies have analyzed open vs arthroscopic techniques, the ideal location of tenodesis with intra-articular, suprapectoral, subpectoral, extra-articular top of groove, and extra-articular bottom of groove approaches, and the best method of fixation using interference screws, suture anchors, or cortical buttons. Orthopaedic surgeons should be aware of the complications of each procedure and respond accordingly for each patient. Once treated, patients often have good to excellent clinical outcomes and low rates of complications.

The rate and reporting of fracture after biceps tenodesis: A systematic review

BACKGROUND

The purpose of this systematic review was to (1) define the cumulative humerus fracture rate after BT and (2) compare how often fracture rate was reported compared to other complications.

METHODS

A systematic review was performed using the PRISMA guidelines.

RESULTS

39 studies reported complications and 30 reported no complications. Of the 39 studies that reported complications, 5 studies reported fracture after BT (n = 669, cumulative incidence of 0.53%). The overall non-fracture complication rate was 12.9%.

DISCUSSION

Due to the relatively high incidence of fracture, surgeons should ensure that this complication is disclosed to patients undergoing BT.

All-Arthroscopic Anatomic Length-Tension Biceps Tenodesis With Unicortical Button

The long head of the biceps tendon is a frequent cause of persistent anterior shoulder pain. Biceps tenodesis is a popular choice for surgical management of this pathology, with myriad approach and fixation variations described. We describe an all-arthroscopic suprapectoral biceps tenodesis in the anatomic length-tension relation using a unicortical button. This technique offers an alternative method that provides proper tendon fixation at anatomic length with minimized additional surgical morbidity and postoperative complications.

Arthroscopic Proximal Subpectoral Tenodesis of the Long Head of the Biceps

Biceps tenodesis is a common treatment method for biceps pathology. When tenodesis is located in intra-articular or suprapectoral areas, the biceps is fixed proximally to the zone of degeneration and inflammation, which can cause residual pain as a possible postsurgical complication. The main advantage of this method is that this technique is comparatively easy and can be performed arthroscopically. Typically, in terms of professional athletes, the best post-biceps tenodesis results are observed after undergoing subpectoral tenodesis because of the solid fixation and localization distally to any kind of biceps tendon degeneration and inflammation zone. However, subpectoral tenodesis has several disadvantages, as it is an open procedure that can lead to possible scar and hematoma formation, infection, bioabsorbable screw reaction, neurovascular injury, and fractures. Soft-tissue tenodesis to the proximal part of pectoralis major tendon is a well-known step in shoulder arthroplasty surgery and shows acceptable results. We suggest a technique of proximal subpectoral arthroscopic tenodesis, which combines the advantages of the location in the subpectoral zone with an all-suture anchor and that of soft-tissue tenodesis to the pectoralis major tendon, which can be performed fully arthroscopically, improving results in terms of healing by increasing the contact area.

Editorial Commentary: Biceps Tenodesis Fixation: Screw, Button, or None of the Above?

Clinical outcomes following shoulder subpectoral biceps tenodesis are generally favorable, with a very low complication rate (2%). One of the most devastating complications following this procedure is the occurrence of a proximal humerus fracture. Although all constructs have their unique advantages and disadvantages, creating a smaller bone hole while achieving good biomechanical outcomes is worth considering. This may be most advantageous in overhead-throwing athletes, tennis players, and/or volleyball athletes, who subject their shoulders to more torsional load due to the requirements of their sport. Thus, in addition to screws and buttons, smaller-diameter suture anchors could also be thoughtfully considered as a biceps tenodesis fixation option.