Double-loaded Suture Anchors Research Articles

The Subscapularis Interlocking Stitch for the Arthroscopic Treatment of Subscapularis Tendon Tears at the Shoulder

Restoration of subscapularis function is essential for long-term maintenance of good clinical results for both traumatic and nontraumatic rotator cuff tears. The anatomic repair of partially and completely torn tendons from the footprint at the lesser tuberosity is the goal of surgical repair. The described technique, with a combination of an interlocking stitch and additional mattress sutures using a double-loaded suture anchor, provides reduction of the retracted tendon, sufficient pullout strength, and compression of the tendon to the footprint to facilitate healing.

Reconstruction of 25 and 50% subscapularis tears: a single anchor with a double-mattress suture is sufficient for the reconstruction.

Evaluation of the biomechanical performance of repairs of 25% (Fox/Romeo II) and 50% (Fox/Romeo III) full-thickness subscapularis tears using a single-suture anchor. Six pairs of human cadaver specimens were used for the testing. Artificial subscapularis tears were created in order to simulate a 25% (6) and a 50% (6) full-thickness tear. The reconstructions were made with a double-loaded suture anchor (5.5-mm Bio-Corkscrew with two No. 2 Fiberwire) creating a double-mattress suture repair. Reconstructions were cyclically loaded from 10 to 60N. The load was increased stepwise up to 100 and 180N. Cyclic displacement (means+standard dev.) as well as load-to-failure was determined, and mode of failure was recorded. In the reconstructed shoulders at 60N, a mean cyclic displacement of 3.2±0.7mm was found in the 25% tear, 2.6±0.6mm in the 50% tear. At 100N, 5.1±1.2mm was seen in the 25% tear and 4.3±0.3mm in the 50% tear. At highest load of 180N, 7.6±2.2mm was recorded in the 25% tear, 6.5±0.8mm was found in the 50% tear. Ultimate failure load was 486±167N in the 25% tear and 455±213N in the 50% tear. Statistically significant differences between the tested repairs were seen neither in cyclic displacement nor in ultimate failure loads (p>0.05). Mode of failure revealed bone fractures and anchor pull-out as major cause in the 25% group, whereas failure of the suture-tendon interface was the major cause of failure in the 50% group. Subscapularis repair using a single double-loaded suture anchor revealed similar biomechanical performance in 25% compared to 50% full-thickness subscapularis tears. With increased tear size, however, an optimized suture-tendon interface seems to become more relevant in order to decrease failure rate of the repair. A single double-loaded suture anchor provides sufficient biomechanical strength even in Fox/Romeo grade III tears of the subscapularis tendon. However, a modified suture configuration is recommended, especially in grade III tears as the suture-tendon interface is the weakest point of the construct.

Biomechanical Analysis of Scapholunate Ligament Repair Techniques

To evaluate the biomechanical properties of 3 scapholunate repair techniques. In 51 cadavers, the scapholunate ligament was exposed through a dorsal approach, incised at its scaphoid insertion, and repaired using 1 of 3 techniques: 2 single-loaded suture anchors, 2 double-loaded suture anchors, or 2 transosseous sutures. Twenty-four repaired specimens underwent load to failure (LTF) testing using tensile distraction on a servo-hydraulic machine. Twenty-seven specimens underwent cyclical testing to measure gap formation at the scapholunate joint. The mode of failure was suture pullout through the substance of the ligament in 22specimens, failure at the bone suture interface in 1, and anchor pullout in 1. Double-loaded anchor repairs demonstrated a significantly higher mean ultimate LTF compared with single-loaded anchor (91 N vs 35 N) and transosseous (91 N vs 60 N) repairs. Transosseous repairs demonstrated a higher mean ultimate LTF compared with single-loaded suture repairs (60 N vs 35 N). After 300 cycles, the average gap for the transosseous repair group was double that for the single- and double-loaded repairs, although not statistically significant. Primary scapholunate ligament repairs using double-loaded suture anchors demonstrated significantly higher strength compared with single-loaded anchors and transosseous repairs. On cyclic loading, transosseous repairs demonstrated the greatest gap formation with no measurable difference between single- and double-loaded repairs. In a cadaveric model for primary repairs, double-loaded suture anchors demonstrated the highest LTF and offer a similar but unproven performance invivo.

The biomechanical performance of a new forked knotless biceps tenodesis compared to a knotless and suture anchor tenodesis

Biomechanical comparison of three different fixation techniques for a proximal biceps tenodesis. Eighteen human cadaver specimens were used for the testing. A tenodesis of the proximal biceps tendon was performed using a double-loaded suture anchor (5.5-mm Corkscrew, Arthrex), a knotless anchor (5.5-mm SwiveLock, Arthrex) or a forked knotless anchor (8-mm SwiveLock, Arthrex). Reconstructions were cyclically loaded for 50 cycles from 10-60 to 10-100N. Cyclic displacement and ultimate failure loads were determined, and mode of failure was evaluated. Cyclic displacement at 60N revealed a mean of 3.3±1.1mm for the Corkscrew, 5.4±1.4mm for the 5.5-mm SwiveLock and 2.9±1.6mm for the 8-mm forked SwiveLock. At 100N, 5.1±2.2mm were seen for the Corkscrew anchor, 8.7±2.5mm for the 5.5-mm SwiveLock and 4.8±3.3mm for the 8-mm forked SwiveLock anchor. Significant lower cyclic displacement was seen for the Corkscrew anchor (p<0.020) as well as the 8-mm SwiveLock anchor (p<0.023) compared to the 5.5-mm SwiveLock anchor at 60N. An ultimate load to failure of 109±27N was found for the Corkscrew anchor, 125±25N were measured for the 5.5-mm SwiveLock anchor, and 175±42N were found for the 8-mm forked SwiveLock anchor. Significant differences were seen between the 8-mm SwiveLock compared to the 5.5-mm SwiveLock (p<0.044) as well as the Corkscrew anchor (p<0.009). No significant differences were seen between the Corkscrew and the 5.5-mm SwiveLock anchor. The new 8-mm forked SwiveLock anchor significantly enhances construct stability compared to a 5.5-mm double-loaded Corkscrew anchor as well as the 5.5-mm SwiveLock suture anchor. However, a restrictive postoperative rehabilitation seems to be important in all tested reconstructions in order to avoid early failure of the construct.

Endoscopic Repair of Tears of the Superficial Layer of the Distal Triceps Tendon

The purpose of this study was to evaluate the results after endoscopic repair of partial superficial layer triceps tendon tears. Fourteen patients treated surgically between July 2005 and December 2012 were studied prospectively for 12 months. Indication for surgery was a partial detachment of the triceps tendon from the olecranon that was proved by magnetic resonance imaging (MRI) in all cases. Ten of these patients had chronic olecranon bursitis. All patients were treated with endoscopic surgery including bursectomy and repair of the distal triceps tendon with double-loaded suture anchors. Clinical examination of the patients as well as functional and subjective scores (Mayo Elbow Performance Index [MEPI], Disabilities of the Arm, Shoulder and Hand Score [Quick DASH]) were obtained preoperatively and postoperatively at 6 and 12 months. An isokinetic strength measurement and MRI were performed preoperatively and 12 months after surgery. All 14 patients were completely evaluated. The MEPI and Quick DASH Score improved significantly after the repair at all postoperative examinations. The MEPI gained 29 points, up to 96 points at last follow-up (P < .05), and the Quick DASH Score went down 15.6 points after 12 months to 4.5 points (P < .05). Maximum extension power improved 55.8%, up to 94.7% at last follow-up compared with the contralateral side. UsingMRI, we found one reruptured partial tear of the triceps tendon that did not require revision surgery. Although triceps tendon ruptures are generally uncommon, partial superficial tears might be more common than previously described. Once the diagnosis is made, endoscopic repair is a method leading to good clinical results with improved function of the affected elbow. Endoscopic repair of superficial tears of the triceps tendon is able to restore function and strength and leads to excellent clinical results after 1 year. Strength recovers to nearly that of the contralateral side, and serious complications appear to be infrequent. Level IV, therapeutic case series.

Footprint Contact Restoration Between the Biceps-Labrum Complex and the Glenoid Rim in SLAP Repair: A Comparative Cadaveric Study Using Pressure-Sensitive Film

To compare pressurized footprint contact and interface pressure between the biceps-labrum complex and the superior glenoid rim after SLAP repair using 3 different techniques. Twenty-four fresh-frozen human cadaveric shoulders were divided into 3 groups. SLAP lesions were repaired by (1) 2 single-loaded anchors in a simple suture configuration (group T), (2) a double-loaded anchor in a simple suture configuration in a V shape (group V), or (3) a double-loaded anchor by use of a hybrid simple and mattress suture configuration (group H). Pressure-sensitive film quantified pressurized contact areas and interface pressures between the biceps-labrum complex and the glenoid rim after SLAP repair. Groups T and V showed significantly larger contact areas than group H (P < .0001). However, there was no significant difference between groups T and V. Despite a substantial contact area around the biceps-labrum complex in group T, there was a lack of sufficient contact area just below the biceps anchor. Group V showed a uniform contact area around the entire biceps-labrum complex, but in group H the contact area was concentrated only around the posterior superior labrum, where the simple suture was used. The methods using 2 single-loaded suture anchors and using 1 double-loaded suture anchor with a simple suture configuration showed significantly larger pressurized contact areas than the method using 1 double-loaded suture anchor with both a simple and mattress suture configuration. The interface pressure was not significantly different among groups. Although there have been several kinds of repair techniques and biomechanical studies for the type II SLAP lesion, there has been no study about footprint restoration on the superior glenoid rim. This study analyzed and compared the footprint contact restoration after type II SLAP repair among 3 different techniques.

A Simple Surgical Technique for Subpectoral Biceps Tenodesis Using a Double-Loaded Suture Anchor

Multiple different surgical techniques have previously been described to address long head of the biceps tendinopathy. Subpectoral biceps tenodesis has proven to be an effective procedure to relieve pain and maintain function. We describe a surgical technique for subpectoral biceps tenodesis using a single double-loaded suture anchor implant. Advantages of this procedure include the ease of implant placement and the freedom this technique affords to perform the anchor placement without direct visualization of the docking site.

Two Double-Loaded Suture Anchors Provide Similar Biomechanical Strength When Compared with Three Single-Loaded Suture Anchors in Simulated Bankart Repair

Two Double-Loaded Suture Anchors Provide Similar Biomechanical Strength When Compared with Three Single-Loaded Suture Anchors in Simulated Bankart Repair

The “Double-Pulley” Technique for Arthroscopic Fixation of Partial Articular-Side Bony Avulsion of the Supraspinatus Tendon: A Rare Case of Bony PASTA Lesion

We report the use of the double-pulley technique for arthroscopic fixation of the bony PASTA (partial articular surface tendon avulsion) lesion. Arthroscopic examination documented a 15-mm-long and 8-mm-wide comminuted bony avulsion with 2 main fragments. Two double-loaded suture anchors were placed with a transtendinous technique at the anterior and posterior edges of the lesion respecting the tendon insertion to the avulsed fragment. The medial sutures were retrieved through the intact supraspinatus tendon medially to the fracture. The sutures were initially coupled in a double-pulley configuration generating 2 sutures oriented from anterior to posterior; then a simple suture for each anchor oriented from medial to lateral was obtained. At the end of the procedure, the adequacy of reduction and stability of the fragments were confirmed. At 2 months from surgery, radiographic healing of the fracture was noted and integrity of the supraspinatus tendon insertion to the footprint was confirmed by arthro–magnetic resonance imaging, with full recovery of daily activities and complete active range of motion confirmed at 6 and 12 months. The double-pulley technique allows optimal reduction of bony fragments and reconstruction of normal footprint anatomy even in comminuted fractures. Moreover, it creates a waterproof reduction of the fragments, protecting the fracture site from synovial fluid.

Biomechanical Analysis of a Double-Loaded Glenoid Anchor Configuration

Background: Bankart repair with multiple anchor holes concentrated in the anterior-inferior glenoid may contribute to glenoid weakening and potentially may induce glenoid failure. Purpose: To compare the biomechanical strength of a Bankart repair construct that used 3 single-loaded suture anchors versus a repair construct that used 2 double-loaded suture anchors. Study Design: Comparative laboratory study. Methods: A standard Bankart lesion was created in 18 human cadaveric shoulders (9 matched pairs). Within each matched pair, 1 repair construct used 3 single-loaded anchors, whereas the other used 2 double-loaded suture anchors. Measured outcomes (load, stiffness, and energy absorbed) were recorded at failure and at 2 mm of labral displacement. Constructs were loaded to failure with a materials testing device that had differential variable reluctance transducers for displacement measurements. Results: The double-loaded anchor construct had a significantly higher ultimate tensile load (944 ± 231 vs 784 ± 287 N; P = .03). For the other measures (load at 2 mm of displacement, energy absorbed at failure and at 2 mm of displacement and stiffness), there were no significant differences between tested constructs. Conclusion: A Bankart repair construct that used 2 double-loaded anchors was either superior to or equal to a repair construct that used 3 single-loaded anchors in all measured outcomes. Clinical Relevance: Using 2 double-loaded suture anchors for a Bankart repair may limit anchor holes in the glenoid and reduce the risk of postsurgical glenoid fracture while providing a stable repair construct.

The Use of Double-Loaded Suture Anchors for Labral Repair and Capsular Repair During Hip Arthroscopy

With the development of hip joint preservation procedures, the use of hip arthroscopy has grown dramatically over the past decade. However, recent articles have reported cases of hip instability after hip arthroscopy. Little is known about the role of static and dynamic stabilizers on hip joint stability, but there are concerns that an extensile capsulotomy or capsulectomy, osteoplasty of the acetabulum and proximal femur, and labral detachment or debridement during hip arthroscopy could potentially compromise hip stability. The safety parameters for arthroscopic hip surgery have not yet been fully established, and techniques are being developed for labral refixation and capsular repair after arthroscopic treatment of femoroacetabular impingement in an attempt to decrease the chance of iatrogenic hip instability or microinstability. The surgical technique presented in this article may provide anatomic repair of both the labrum and capsule using a double-loaded suture anchor technique. We believe that this technique increases both operative efficiency and the strength of the overall repair, which may minimize the risk of iatrogenic hip instability after hip arthroscopy.

Arthroscopic Bankart Repair Using Extracapsular Suture Between the Glenohumeral Ligaments and Subscapularis Tendon (BLS Technique)

Arthroscopic Bankart repair has traditionally been performed entirely within the capsule, but this has led to less favorable outcomes than those after open repair, and glenohumeral joint damage may occur in some instances due to the close proximity of suture knots to the articular surface. We describe a modification of standard arthroscopic Bankart repair using double-loaded suture anchors which positions the knots away from outside the shoulder capsule. These extracapsular sutures not only provide excellent anterior stabilization, but also eliminate contact of foreign material with intra-articular structures.

Arthroscopic Revision Bankart Repair: A Preliminary Evaluation

Arthroscopic stabilization of primary, recurrent anterior shoulder instability has become the procedure of choice with infrequent exceptions. Failures of stabilization can and do occur. This is a Level IV retrospective analysis of arthroscopic revision Bankart surgery performed on 15 non-consecutive patients over a 4-year period with an average 22-month follow-up. The average patient age was 27.5 with 12 men and 3 women. Four of the 15 failures were from the senior author's (R.K.N.R.) practice with the remaining 11 referred for treatment. Four of the 15 failures resulted from open surgery while the remaining 11 failed an arthroscopic stabilization procedure. Four contact/collision athletes were included, and significant bone loss was recorded in 5 patients. Operative findings included 10 recurrent Bankart lesions while 9 patients were felt to demonstrate capsular attenuation. Fourteen of the 15 had a Hill-Sachs lesion while chondromalacic change involving the anterior glenoid was noted in 13 of the 15 patients. A suture anchor technique was used with an average of 2.5 double-loaded suture anchors. In this series, 4 failures occurred after revision arthroscopic stabilization (27%) with an average SANE score of 86 (range, 65-100). One of the 5 patients with significant bone loss sustained a recurrence while 1 of 4 contact athletes failed the revision arthroscopic stabilization. Two of the 4 failures in this study subsequently underwent an open bone block procedure. Arthroscopic revision Bankart repair can be an effective alternative, but should only be considered in the properly selected patient.

“Hospital-Corner Repair” for Shoulder Instability

AbstractMost shoulder instability repairs are performed with single-loaded suture anchors. Recent reports have shown that there is increased stress on both the glenoid labrum and suture anchor when sutures from single-loaded anchors are passed through the capsule and labrum. This report describes a novel technique for shoulder instability repair using double-loaded suture anchors in the glenoid. The first primary stitch is passed through the labrum only and then tied, shifting the tissue superiorly. The second stitch is passed inferiorly through the patulous capsule in addition to the labrum with a pinch-tuck technique. This technique distributes the tension on the labral repair and creates a fold to protect and shield the primary labral repair. Just as flat sheets are folded and tucked underneath a mattress to form a “hospital corner,” this procedure applies a similar principle to the labrum and capsule of the shoulder. This technique is applicable for any type of shoulder instability repair, including Bankart lesions, posterior labral tears, and multidirectional instability, that requires the use of suture anchors.

Tendon-grasping strength of various suture configurations for rotator cuff repair

The purpose of the present study is to evaluate the mechanical performance and initial strength of the arthroscopic Mason-Allen, double mattress, inclined Mason-Allen, and lasso loop stitch configurations. Using 36 sheep infraspinatus tendons, tendon widths and thicknesses were measured with a digital caliper to confirm standardization of the tendons. Four different stitch configurations (Mason-Allen, inclined Mason-Allen, double mattress, and lasso loop) were biomechanically tested with cyclic loading followed by load to failure testing. The cyclic elongation, peak-to-peak displacement, ultimate tensile strength, stiffness, and mode of failure were recorded. Mean tendon widths and thicknesses were statistically the same. The lasso loop (0.7±0.1mm) demonstrated a mean cyclic elongation greater than the Mason-Allen (0.5±0.3mm) and double mattress (0.5±0.3mm) groups (P=0.011; P=0.013). No differences were found in ultimate failure load, stiffness, and peak-to-peak displacement for the Mason-Allen (mean 99±42N, 39±9N/mm, 0.6±0,1mm), inclined Mason-Allen (113±52N, 44±14N/mm, 0.5±0.1mm), double mattress stitch (119±68N, 45±10N/mm, 0.5±0.1mm), or lasso loop (100±38N, 42±7N/mm, 0.5±0.1mm) groups (n.s.). Each specimen failed at the suture-tendon interface. Three specimens (two Mason-Allen and one inclined Mason-Allen) failed during cyclic testing. Conventional Mason-Allen configuration can be applied with double-loaded suture anchor safely. Recent modifications of the configurations offer no biomechanical advantage.

Arthroscopic Repair of a Traumatic Massive Posterior Rotator Cuff Tear in a 14-year-old Teenager

Rotator cuff tears in adolescents are extremely rare, with no reported cases of arthroscopic repair being available in the literature thus far. A 14-year-old boy sustained a traumatic tear of his supraspinatus and infraspinatus muscles of the rotator cuff during a fall off his motorcycle during a motocross race. He also sustained a contralateral mid-shaft clavicle fracture. The rotator cuff was repaired arthroscopically with two rows of double loaded suture anchors. The clavicle was fixed with an elastic intramedullary nail. This was followed by intensive physiotherapy, and the patient returned to full pre-injury function in his shoulder by 6 months postoperatively.

A Biomechanical Analysis of Anterior Bankart Repair Using Suture Anchors

Background: Arthroscopic repair of anterior Bankart lesions is typically done with single-loaded suture anchors tied with simple stitch configuration. Hypothesis: The knotless suture anchor will have similar biomechanical properties compared with two types of conventional suture anchors. Study Design: Controlled laboratory study. Methods: Fresh-frozen shoulders were dissected and an anteroinferior Bankart lesion was created. For phase 1, specimens were randomized into either simple stitch (SSA) or knotless suture anchors (KSA) and loaded to failure. For phase 2, specimens were randomized into 1 of 4 repair techniques and cyclically loaded then loaded to failure: (1) SSA, (2) suture anchor with horizontal mattress configuration, (3) double-loaded suture anchor with simple stitch configuration, or (4) KSA. Data recorded included mode of failure, ultimate load to failure, load at 2 mm of displacement, as well as displacement during cyclical loading. Results: For phase 1, the load required to 2 mm displacement of the repair construct was significantly greater in SSA (66.5 ± 21.7 N) than KSA (35.0 ± 12.5 N, P = .02). For phase 2, there was a statistically significant difference in ultimate load to failure among the 4groups, with both the single-loaded suture anchor with simple stitch (184.0 ± 64.5 N), horizontal mattress stitch (189.0 ± 65.3N), and double-loaded suture anchor with simple stitch (216.7 ± 61.7 N) groups having significantly (P < .05) higher loads than the knotless group (103.9 ± 52.8 N). There was no statistically significant difference (P > .05) among the 4 groups in displacement after cyclical loading or load at 2 mm of displacement. Conclusion: Both knotless and simple anchor configurations demonstrated similar single loads to failure (without cycling); however, the knotless device required less single load to displace 2 mm. All repair stitches, including simple, horizontal, and double-loaded performed similarly. Clinical Relevance: The findings may suggest that with cyclical loading up to 25 N there is no difference in gapping greater than 2mm, but a macrotraumatic event may demonstrate a difference in fixation during the initial postoperative period. Additional in vivo studies are needed to determine whether these differences affect the integrity of the repair construct and, ultimately, the clinical outcome.

Biomechanical Advantages of Triple-Loaded Suture Anchors Compared With Double-Row Rotator Cuff Repairs

To evaluate the strength and suture-tendon interface security of various suture anchors triply and doubly loaded with ultrahigh-molecular weight polyethylene-containing sutures and to evaluate the relative effectiveness of placing these anchors in a single-row or double-row arrangement by cyclic loading and then destructive testing. The infraspinatus muscle was reattached to the original humeral footprint by use of 1 of 5 different repair patterns in 40 bovine shoulders. Two single-row repairs and three double-row repairs were tested. High-strength sutures were used for all repairs. Five groups were studied: group 1, 2 triple-loaded screw suture anchors in a single row with simple stitches; group 2, 2 triple-loaded screw anchors in a single row with simple stitches over a fourth suture passed perpendicularly ("rip-stop" stitch); group 3, 2 medial and 2 lateral screw anchors with a single vertical mattress stitch passed from the medial anchors and 2 simple stitches passed from the lateral anchors; group 4, 2 medial double-loaded screw anchors tied in 2 mattress stitches and 2 push-in lateral anchors capturing the medial sutures in a "crisscross" spanning stitch; and group 5, 2 medial double-loaded screw anchors tied in 2 mattress stitches and 2 push-in lateral anchors creating a "suture-bridge" stitch. The specimens were cycled between 10 and 180 N at 1.0 Hz for 3,500 cycles or until failure. Endpoints were cyclic loading displacement (5 and 10 mm), total displacement, and ultimate failure load. A single row of triply loaded anchors was more resistant to stretching to a 5- and 10-mm gap than the double-row repairs with or without the addition of a rip-stop suture (P < .05). The addition of a rip-stop stitch made the repair more resistant to gap formation than a double row repair (P < .05). The crisscross double row created by 2 medial double-loaded suture anchors and 2 lateral push-in anchors stretched more than any other group (P < .05). Double-row repairs with either crossing sutures or 4 separate anchor points were more likely to fail (5- or 10-mm gap) than a single-row repair loaded with 3 simple sutures. The triple-loaded anchors with ultrahigh-molecular weight polyethylene-containing sutures placed in a single row were more resistant to stretching than the double-row groups.

Cell biological and biomechanical evaluation of two different fixation techniques for rotator cuff repair

Our objective was to evaluate the cell biology and biomechanical aspects of the healing process after two different techniques in open rotator cuff surgery - double-loaded bio-absorbable suture anchors combined with so-called arthroscopic Mason-Allen stitches (AAMA) and a trans-osseous suture technique combined with traditional modified Mason-Allen stitches (SMMA). Thirty-six mature sheep were randomized into two repair groups. After 6, 12, or 26 weeks, evaluation of the reinsertion site of the infraspinatus tendon was performed. The mechanical load-to-failure and stiffness results did not indicate a significant difference between the two groups. After 26 weeks, fibrocartilage was sparse in the AAMA group, whereas the SMMA group showed the most pronounced amount of fibrocartilage. We found no ultrastructural differences in collagen fiber organization between the two groups. The relative expression of collagen type II mRNA in the normal group was 1.11. For the AAMA group, 6 weeks after surgery, the relative expression was 55.47, whereas for the SMMA group it was 1.90. This in vivo study showed that the AAMA group exhibited a tendon-to-bone healing process more favorable in its cell biology than that of the traditional SMMA technique. Therefore, the AAMA technique might also be more appropriate for arthroscopic repair.

Interference Screw Versus Suture Anchor Fixation for Subpectoral Tenodesis of the Proximal Biceps Tendon: A Cadaveric Study

The purpose of this study was to compare the biomechanical properties of 2 fixation methods for subpectoral proximal biceps tenodesis. In 9 matched pairs of cadaveric shoulders, an open subpectoral tenodesis was performed 1 cm proximal to the inferior border of the pectoralis major tendon by use of either an 8 x 12-mm Bio-Tenodesis screw (Arthrex, Naples, FL) with No. 2 FiberWire sutures (Arthrex) or a 5.5-mm Bio-Corkscrew double-loaded suture anchor (Arthrex) with No. 2 FiberWire sutures. The specimens were dissected and mounted in a material testing machine. Cyclic loading (20 to 60 N, 100 cycles, 0.5 mm/s, 5-N preload) was performed, followed by an unloaded 30-minute rest, a 5-N preload, and a load-to-failure protocol (1.25 mm/s) with a 100-lb load cell. Ultimate load (in Newtons), stiffness (in Newtons per millimeter), and modes of failure were recorded. Data were analyzed by use of paired t tests and Wilcoxon signed rank tests. Proximal biceps tenodeses with Bio-Tenodesis screws had a significantly higher mean load to failure (169.6 +/- 50.5 N; range, 99.6 to 244.7 N) than those with Bio-Corkscrew suture anchors (68.5 +/- 33.0 N; range, 24.2 to 119.4 N) (P = .002). Bio-Tenodesis screws also had a significantly higher stiffness (34.1 +/- 9.0 N/mm; range, 20.6 to 48.9 N/mm) than Bio-Corkscrews (19.3 +/- 10.5; range, 5.9 to 32.9 N/mm) (P = .038). In this cadaveric study the Bio-Tenodesis screw showed a statistically significantly higher load to failure and significantly higher stiffness than the Bio-Corkscrew anchor when used for tenodesis of the proximal biceps tendon in a subpectoral location. Biomechanical comparison of these 2 fixation techniques provides information on stiffness and load to failure of alternate fixation methods.