Biomechanical Comparison of Screw Fixation Versus a Cortical Button and Self-tensioning Suture for the Latarjet Procedure

Background: Metal screws are traditionally used to fix the coracoid process to the glenoid. Despite stable fixation, metal screws have been associated with hardware complications. Therefore, some studies have advocated for suture button fixation during the Latarjet procedure to reduce the complications associated with screw fixation. Purpose: To biomechanically evaluate the ultimate failure load of a cortical button and self-tensioning suture versus metal screws for coracoid graft fixation during the Latarjet procedure. Study Design: Controlled laboratory study. Methods: Eight matched pairs of fresh-frozen, male cadaveric shoulders (N = 16) underwent the Latarjet procedure. The shoulders of each pair were randomly assigned to 1 of 2 groups: fixation using two 3.75-mm cannulated, fully threaded metal screws or fixation using a double suture button construct. Specimens were secured in a dynamic testing machine and cyclically preconditioned from 2 to 10 N at 0.1 Hz for 10 cycles. After preconditioning, specimens were pulled to failure at a normalized displacement rate of 400% of the measured gauge length per minute. The ultimate failure load and mechanism of failure were recorded for each specimen. Results: The mean ultimate load to failure for screw fixation (226 ± 114 N; 95% CI, 147-305 N) was not significantly different from that for suture button fixation (266 ± 73 N; 95% CI, 216-317 N) ( P = .257). The mean strain at failure for screw fixation (63% ± 21%; 95% CI, 48%-77%) was not significantly different from that for suture button fixation (86% ± 26%; 95% CI, 69%-104%) ( P = .060). The most common mechanism of failure for the screw fixation method was at the bone block drill holes, while an intramuscular rupture at the clamp-muscle interface occurred for the suture button construct. Conclusion: The screw and suture button fixation techniques exhibited comparable biomechanical strength for coracoid bone block fixation of the Latarjet procedure. Clinical Relevance: Metal screws have been reported to be a large contributor to intraoperative and postoperative complications. Therefore, given the results of the current study, a suture button construct may be an alternative to metal screw fixation during the Latarjet procedure. However, further clinical studies are warranted.

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Factors affecting biomechanical strength of Latarjet constructs: A systematic review and meta-regression

Shoulder & Elbow ◽

10.1177/1758573220960462 ◽

2020 ◽

pp. 175857322096046

Author(s):

Eric G Huish Jr ◽

Shayne R Kelly ◽

Brenden M Cutter

Keyword(s):

Systematic Review ◽

Failure Load ◽

Screw Fixation ◽

Shear Stresses ◽

Glenohumeral Instability ◽

Ultimate Failure Load ◽

Tensile Forces ◽

Drill Diameter ◽

Ultimate Failure ◽

Meta Regression

Background The Latarjet procedure reduces recurrent glenohumeral instability but has potential hardware and graft complications. The procedure has been modified to use various screw types as well as suture buttons. Biomechanical studies have evaluated the effect of these implants on construct strength. With varying results it is unclear whether there is an optimal implant to use. Methods We conducted a systematic review of human cadaveric biomechanical studies evaluating Latarjet ultimate failure load. Two independent reviewers screened articles and included them after full text review. Additional factors including implants used, graft orientation, cortices engaged, drill diameter, and screw characteristics were recorded. Meta-regression was performed on the 145 specimens from eight studies that met inclusion criteria. Results Screw fixation resulted in a 396.8 N (95% CI, 149.8–643.7) N higher ultimate failure load against shear stresses than suture buttons (p = 0.002). There were no differences between implants for ultimate failure load against tensile forces. Tensile strength was significantly affected by drill diameter with each millimeter of increase reducing the mean ultimate failure load by 127.4 N (95% CI, 41.2–213.6) N (p = 0.004). Conclusions These results suggest that using screw fixation and minimizing drill diameter can obtain the maximum ultimate failure load against both shear and tensile forces in a Latarjet construct.

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Suture versus screw fixation technique for tibial eminence fracture: A meta-analysis of laboratory studies

Journal of Orthopaedic Surgery ◽

10.1177/2309499020907977 ◽

2020 ◽

Vol 28 (1) ◽

pp. 230949902090797

Author(s):

Mao Ye ◽

Jun Chen ◽

Feng Hu ◽

Yanxi Liu ◽

Yang Tan

Keyword(s):

Failure Load ◽

Screw Fixation ◽

Laboratory Studies ◽

Cyclic Testing ◽

Fixation Technique ◽

Ultimate Failure Load ◽

Significant Difference ◽

Suture Group ◽

Ultimate Failure ◽

Screw Group

Purpose: The aim of this study was to compare the biomechanical properties between the suture fixation technique and the screw fixation technique for tibial eminence fracture (TEF). Methods: The current study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Embase, and the Cochrane were searched from inception to January 2019 comparing the suture and the screw fixation technique for TEF. The results of the eligible studies were analyzed in terms of stiffness, ultimate failure load, and displacement after the cyclic testing. Results: Six laboratory studies were included with a total of 114 knees: 57 knees were in the FiberWire suture group and 57 knees were in the single-screw group. The suture group had higher stiffness than the screw group, but there was no statistical difference between these two groups. Ultimate failure load in the suture group was statistically higher than that in the screw group. No statistically significant difference existed in displacement after the cyclic testing between the suture group and the screw group. Conclusion: The FiberWire suture fixation may be biomechanically superior to a single screw fixation in TEF treatment in mature knees regarding ultimate failure load, while no significant difference was found between the two fixations in terms of stiffness and displacement after the cyclic testing.

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Biomechanical Testing of Three Alternative Quadrupled Tendon Graft Constructs With Adjustable Loop Suspensory Fixation for Anterior Cruciate Ligament Reconstruction Compared With Four-Strand Grafts Fixed With Screws and Femoral Fixed Loop Devices

The American Journal of Sports Medicine ◽

10.1177/0363546518825256 ◽

2019 ◽

Vol 47 (4) ◽

pp. 828-836 ◽

Cited By ~ 5

Author(s):

Christopher J. Vertullo ◽

Marina Piepenbrink ◽

Patrick A. Smith ◽

Adrian J. Wilson ◽

Coen A. Wijdicks

Keyword(s):

Failure Load ◽

Screw Fixation ◽

Cruciate Ligament ◽

Total Elongation ◽

Tendon Graft ◽

Ultimate Failure Load ◽

Suspensory Fixation ◽

Ultimate Failure ◽

Anterior Cruciate ◽

Preparation Techniques

Background: Quadrupled semitendinosus (ST) grafts for anterior cruciate ligament (ACL) reconstruction have advantages of greater graft diameter and gracilis (G) preservation compared with doubled ST-G grafts. However, a paucity of biomechanical data are available regarding different preparation techniques for these constructs. Purpose: To biomechanically analyze 3 alternative tendon constructs fixed with adjustable suspensory fixation devices on the femur and tibia compared with a matched 4-strand construct fixed with a tibial screw and femoral fixed loop device. Study Design: Controlled laboratory study. Methods: Three alternative quadrupled tendon preparation techniques with suspensory fixation (grafts constructs A, B, and C) were compared with a 4-strand screw-fixed loop device construct (graft construct D) in matched diameter bovine tendon graft and porcine tibia models. Graft constructs were tested with a 3-stage cyclic loading protocol (1000 cycles in position control and 1000 cycles each from 10 to 250 N and from 10 to 400 N), followed by a pull to failure. In graft construct A, the graft ends were whipstitched and tied over the tibial button; in graft construct B, the graft ends functioned as pulleys; and in graft construct C, a continuous loop was created. Initial, dynamic, and total elongation, stiffness, and ultimate failure load were recorded. Results: Graft construct D had the highest initial (0.51 ± 0.29 mm) and total (3.53 ± 0.98 mm) elongation compared with the 3 quadrupled constructs ( P < .001 each). Graft construct B had lower total elongation (2.13 ± 0.31 mm) compared with graft construct A (2.40 ± 0.30 mm) ( P = .004) and graft construct C (2.53 ± 0.21 mm) ( P = .007). Graft construct C had a higher ultimate failure load (1097 ± 79 N) compared with graft construct A (988 ± 112 N) ( P = .001), graft construct B (973 ± 137 N) ( P = .022), and graft construct D, which had the lowest failure load (767 ± 182 N) ( P < .001). Conclusion: The 3 quadrupled tendon suspensory fixation constructs exhibited small yet statistically significant biomechanical differences among each other. Constructs that used tibial screw fixation had lower ultimate failure load and higher total elongation compared with the quadrupled tendon constructs. Clinical Relevance: Total elongation for the screw fixation group was higher than the threshold of clinical failure, which may allow for graft construct elongation during the postoperative rehabilitation phase. Biomechanical properties of the 3 quadrupled tendon suspensory graft constructs may be clinically comparable, albeit statistically different.

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Different Suture Materials for Arthroscopic Transtibial Pull-out Repair of Medial Meniscal Posterior Root Tears: A Human Biomechanical Study

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967119873274 ◽

2019 ◽

Vol 7 (9) ◽

pp. 232596711987327

Author(s):

Gilberto Y. Nakama ◽

Zachary S. Aman ◽

Hunter W. Storaci ◽

Alexander S. Kuczmarski ◽

Joseph J. Krob ◽

...

Keyword(s):

Medial Meniscus ◽

Failure Load ◽

Clinical Care ◽

Posterior Root ◽

Clinical Failure ◽

Postoperative Rehabilitation ◽

Pull Out ◽

Ultimate Failure Load ◽

Ultimate Failure ◽

Suture Tape

Background: Transtibial pull-out repair of the medial meniscal posterior root (MMPR) has been largely assessed through biomechanical studies. Biomechanically comparing different suture types would further optimize MMPR fixation and affect clinical care. Purpose/Hypothesis: The purpose of this study was to determine the optimal suture material for MMPR fixation. It was hypothesized that ultra high–molecular weight polyethylene (UHMWPE) suture tape would be biomechanically superior to UHMWPE suture and standard suture. Study Design: Controlled laboratory study. Methods: The MMPR attachment was divided in 24 human cadaveric knees and randomly assigned to 3 repair groups: UHMWPE suture tape, UHMWPE suture, and standard suture. Specimens were dissected down to the medial meniscus, and the posterior root attachments were sectioned off the tibia. Two-tunnel transtibial pull-out repair with 2 sutures, as determined by the testing group, was performed. The repair constructs were cyclically loaded between 10 and 30 N at 0.5 Hz for 1000 cycles to mimic the forces experienced on the medial meniscus during postoperative rehabilitation. Displacement was recorded at 1, 50, 100, 500, and 1000 cycles. Ultimate failure load, displacement at failure, and load at 3 mm of displacement (clinical failure) were also recorded. Results: UHMWPE suture tape had significantly less displacement of the medial meniscus when compared with standard suture at 1 (–0.22 mm [95% CI, –0.41 to –0.02]; P = .025) and 50 (–0.35 mm [95% CI, –0.67 to –0.03]; P = .029) cycles. There were no other significant differences observed in displacement between groups at any number of cycles. UHMWPE suture tape had significantly less displacement at the time of failure than standard suture (–3.71 mm [95% CI, –7.17 to –0.24]; P = .034). UHMWPE suture tape had a significantly higher load to reach the clinical failure displacement of 3 mm than UHMWPE suture (15.64 N [95% CI, 0.02 to 31.26]; P = .05). There were no significant differences in ultimate failure load between groups. Conclusion: The meniscal root repair construct with UHMWPE suture tape may be stronger and less prone to displacement than that with standard suture or UHMWPE suture. Clinical Relevance: UHMWPE suture tape may provide better clinical results compared with UHMWPE suture and standard suture.

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Biomechanical evaluation of a novel double rip-stop technique with medial row knots for rotator cuff repair

Bone and Joint Research ◽

10.1302/2046-3758.96.bjr-2019-0196.r1 ◽

2020 ◽

Vol 9 (6) ◽

pp. 285-292

Author(s):

Zhanwen Wang ◽

Hong Li ◽

Zeling Long ◽

Subin Lin ◽

Andrew R. Thoreson ◽

...

Keyword(s):

Rotator Cuff ◽

Rotator Cuff Repair ◽

Failure Modes ◽

Failure Load ◽

Biomechanical Properties ◽

Gap Formation ◽

Ultimate Failure Load ◽

Fresh Frozen ◽

Ultimate Failure ◽

Cuff Repair

Aims Many biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots. Methods A total of 24 fresh-frozen porcine shoulders were used. The infraspinatus tendons were sharply dissected and randomly repaired by one of three techniques: SB repair (SB group), DRS repair (DRS group), and DRS with medial row knots repair (DRSK group). Specimens were tested to failure. In addition, 3 mm gap formation was measured and ultimate failure load, stiffness, and failure modes were recorded. Results The mean load to create a 3 mm gap formation in the DRSK and DRS groups was significantly higher than in the SB group. The DRSK group had the highest load to failure with a mean ultimate failure load of 395.0 N (SD 56.8) compared to the SB and DRS groups, which recorded 147.1 N (SD 34.3) and 285.9 N (SD 89.8), respectively (p < 0.001 for both). The DRS group showed a significantly higher mean failure load than the SB group (p = 0.006). Both the DRS and DRSK groups showed significantly higher mean stiffness than the SB group. Conclusion The biomechanical properties of the DRS technique were significantly improved compared to the SB technique. The DRS technique with medial row knots showed superior biomechanical performance than the DRS technique alone.

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Osseous Healing With Nonrigid Suture Fixation in the Arthroscopic Latarjet Procedure

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120964489 ◽

2020 ◽

Vol 8 (11) ◽

pp. 232596712096448

Author(s):

Jack W. Weick ◽

Vivek Kalia ◽

Emily Pacheco ◽

Jon A. Jacobson ◽

Michael T. Freehill

Keyword(s):

Ct Scan ◽

Case Series ◽

Ct Scans ◽

Suture Fixation ◽

Latarjet Procedure ◽

Average Percentage ◽

Cortical Button ◽

The Mean ◽

Graft Migration

Background: The Latarjet procedure is a popular means to surgically address anterior glenohumeral joint instability. Although the Latarjet procedure is becoming increasingly common, challenges persist and include postoperative complications secondary to use of the conventional 2 bicortical fixation screws. Recently, a novel surgical technique using a guided surgical approach for graft positioning with nonrigid fixation via a suture suspensory system has been described. Purpose: To evaluate healing rates and stability of the grafts in patients who underwent this new Latarjet technique. Study Design: Case series; Level of evidence, 4. Methods: We retrospectively gathered anonymized computed tomography (CT) data sets from a total of 107 patients who underwent nonrigid suture fixation using a cortical button fixation for anterior glenohumeral instability. Of the 107 patients, 45 had CT scans performed at 2 different time periods. The CT scans of each patient were compared by 2 fellowship-trained musculoskeletal radiologists. Data recorded included age, sex, date of scan, initial graft position on the glenoid, presence and degree of graft migration relative to the equator on follow-up scan, and percentage of osseous healing (as assessed by osseous bridging) on the follow-up scan. Descriptive statistics were calculated to evaluate the average migration and average percentage of healing at both time points. Results: Our population (n = 45) consisted of 38 men (84.4%) and 7 women (15.6%). The mean age was 27.1 ± 1.1 years. The mean time between initial CT scan (2 weeks postoperatively) and follow-up CT scan was 26 ± 2 weeks. On follow-up scan, reviewer 1 found 75.6% of patients had greater than 75% healing, and reviewer 2 found 70.2% of patients had greater than 75% healing. The center of the graft was measured at or below the equator on follow-up examination in 43 of 45 (95.6%) patients by reviewer 1 and 44 of 45 (97.8%) patients by reviewer 2. Conclusion: Based on these findings, nonrigid suture fixation using a cortical button device offers an effective alternative to traditional screw fixation for the Latarjet procedure with a high level of osseous healing and minimal graft migration.

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Modified Arthroscopic Latarjet Procedure: Suture-Button Fixation Achieves Excellent Remodeling at 3-Year Follow-up

The American Journal of Sports Medicine ◽

10.1177/0363546519887959 ◽

2019 ◽

Vol 48 (1) ◽

pp. 39-47 ◽

Cited By ~ 3

Author(s):

Jian Xu ◽

Haifeng Liu ◽

Wei Lu ◽

Zhenhan Deng ◽

Weimin Zhu ◽

...

Keyword(s):

Humeral Head ◽

Case Series ◽

Concentric Circle ◽

Vertical Position ◽

Latarjet Procedure ◽

Level Of Evidence ◽

Suture Button ◽

The Mean ◽

Best Fit

Background: Some studies have advocated the use of suture-button fixation during the Latarjet procedure to reduce complications associated with screw fixation. However, the sample size of these studies is relatively small, and their follow-up period is short. Purpose: To investigate the efficacy of the suture-button Latarjet procedure with at least 3 years of follow-up and remodeling of the coracoid graft. Study Design: Case series; Level of evidence, 4. Methods: A total of 152 patients who underwent the suture-button Latarjet procedure between February 2013 and February 2016 were selected, and 128 patients who met the inclusion criteria were enrolled in this study. Preoperative and postoperative clinical results were assessed. The position and healing condition of the coracoid graft and arthropathy of the glenoid and humeral head were also assessed using radiography and 3-dimensional computed tomography (CT). Results: The mean follow-up time was 40.3 ± 5.8 months. There were 102 patients included in this study. The mean visual analog scale score for pain during motion, the American Shoulder and Elbow Surgeons score, the Rowe score, and the Walch-Duplay score were improved considerably. A total of 100 grafts achieved bone union. The overall absorption rate was 12.6% ± 4.3%. Graft absorption mostly occurred on the edge and outside the “best-fit” circle of the glenoid. A vertical position was achieved in 98 grafts (96% of all cases) immediately postoperatively, with the mean graft midline center at the 4 o’clock position. In the axial view, CT showed that 89 grafts were flush to the glenoid, whereas 2 and 11 grafts were fixed medially and laterally, respectively. In all cases, the bone graft and glenoid tended to extend toward each other to form concentric circles during the remodeling process. During follow-up observations, the height of the 11 grafts that were positioned laterally (ie, above the glenoid level) exhibited a wave-curved change. No arthropathy was observed in any patient. Conclusion: Patient outcomes were satisfactory after the modified arthroscopic suture-button Latarjet technique. Graft absorption mostly occurred on the edge and outside the “best-fit” circle of the glenoid. The graft exhibited the phenomenon of ectatic growing when it fused with the glenoid and finally remodeled to a new concentric circle with the humeral head analogous to the original glenoid. Grafts positioned laterally did not cause arthropathy of the joints within the period of the study.

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Prestressed concrete masonry walls subjected to uniform out-of-plane loading

Canadian Journal of Civil Engineering ◽

10.1139/l93-128 ◽

1993 ◽

Vol 20 (6) ◽

pp. 969-979

Author(s):

J. L. Dawe ◽

G. G. Aridru

Keyword(s):

Prestressed Concrete ◽

Failure Load ◽

Masonry Walls ◽

Prestressing Force ◽

Concrete Masonry ◽

Ultimate Failure Load ◽

Wall Stiffness ◽

Out Of Plane ◽

Ultimate Failure ◽

Concrete Masonry Walls

Two series of post-tensioned concrete masonry walls subjected to uniform lateral loading were tested to investigate their flexural strength behaviour. Each series of walls consisted of four full-scale prestressed specimens, with varying levels of prestressing force, and one reinforced specimen. Of particular interest were the load–deflection curves, initial cracking loads, wall stiffness, crack patterns, and ultimate failure loads. An air bag test apparatus was used for applying lateral uniform pressures to the specimens. Results of this experimental investigation showed that, for a given wall thickness, increased prestressing force increases the cracking load, initial wall stiffness, and ultimate failure load. The results have established a linear relationship between increased prestressing force and initial cracking load, initial wall stiffness, and ultimate failure load. The proposed model, which takes into account changes in wall stiffness after initial cracking of the wall, accurately predicts wall behaviour. Key words: masonry, prestressed, walls, strength, behaviour, uniform, pressure, experimental, analytical.

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Evaluation of Reduction Accuracy of Suture-Button and Screw Fixation Techniques for Syndesmotic Injuries

Foot & Ankle International ◽

10.1177/1071100716661221 ◽

2016 ◽

Vol 37 (12) ◽

pp. 1317-1325 ◽

Cited By ~ 32

Author(s):

Onur Kocadal ◽

Mehmet Yucel ◽

Murad Pepe ◽

Ertugrul Aksahin ◽

Cem Nuri Aktekin

Keyword(s):

Screw Fixation ◽

Ct Scans ◽

Functional Evaluation ◽

Level Of Evidence ◽

Cross Sectional ◽

Suture Button ◽

Fixation Group ◽

Significant Difference ◽

The Mean

Background: Among the most important predictors of functional results of treatment of syndesmotic injuries is the accurate restoration of the syndesmotic space. The purpose of this study was to investigate the reduction performance of screw fixation and suture-button techniques using images obtained from computed tomography (CT) scans. Methods: Patients at or below 65 years who were treated with screw or suture-button fixation for syndesmotic injuries accompanying ankle fractures between January 2012 and March 2015 were retrospectively reviewed in our regional trauma unit. A total of 52 patients were included in the present study. Fixation was performed with syndesmotic screws in 26 patients and suture-button fixation in 26 patients. The patients were divided into 2 groups according to the fixation methods. Postoperative CT scans were used for radiologic evaluation. Four parameters (anteroposterior reduction, rotational reduction, the cross-sectional syndesmotic area, and the distal tibiofibular volumes) were taken into consideration for the radiologic assessment. Functional evaluation of patients was done using the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale at the final follow-up. The mean follow-up period was 16.7 ± 11.0 months, and the mean age was 44.1 ± 13.2. Results: There was a statistically significant decrease in the degree of fibular rotation ( P = .03) and an increase in the upper syndesmotic area ( P = .006) compared with the contralateral limb in the screw fixation group. In the suture-button fixation group, there was a statistically significant increase in the lower syndesmotic area ( P = .02) and distal tibiofibular volumes ( P = .04) compared with the contralateral limbs. The mean AOFAS scores were 88.4 ± 9.2 and 86.1 ± 14.0 in the suture-button fixation and screw fixation group, respectively. There was no statistically significant difference in the functional ankle joint scores between the groups. Conclusion: Although the functional outcomes were similar, the restoration of the fibular rotation in the treatment of syndesmotic injuries by screw fixation was troublesome and the volume of the distal tibiofibular space increased with the suture-button fixation technique. Level of Evidence: Level III, retrospective comparative study.

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Efficacy of Bone Marrow-Stimulating Technique in Rotator Cuff Repair

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117s00080 ◽

2017 ◽

Vol 5 (2_suppl2) ◽

pp. 2325967117S0008

Author(s):

İsmail Kerem Bilsel ◽

Fatih Yıldız ◽

Mehmet Kapıcıoglu ◽

Gokcer Uzer ◽

Mehmet Elmadag ◽

...

Keyword(s):

Bone Marrow ◽

Rotator Cuff ◽

Failure Load ◽

Tendon Healing ◽

Histological Evaluation ◽

Control Group ◽

Time Interval ◽

Lesser Tuberosity ◽

Ultimate Failure Load ◽

Ultimate Failure

Background: This study investigates the effect of microfracture as a bone marrow-stimulating(BMS) technique on rotatory cuff(RC) healing using a chronic RC tear model. Methods: Chronic retracted RC tendon tear model was created in the subscapularis(SSC) tendons of 20 New Zealand rabbits, bilaterally. The tendons were repaired after eight weeks using a single-row configuration with suture anchors. In right shoulders, tendons were repaired in a standard fashion(control group). In left shoulders, microfractures were performed on the SSC footprint before repair(microfracture group). The animals were sacrificed 8 and 16 weeks after repair. The repaired tendons were tested biomechanically for their ultimate failure load, linear stiffness and elongation at failure. Gross and histological evaluation of the tendon-to-bone healing was evaluated. Results: In every sample, the SSC tendon was attached to its footprint on the lesser tuberosity. In microfracture group, collagen fibers were organized in relatively ticker bundles at both time intervals. The mean ultimate failure load of microfracture was significantly greater than that of control group at 8 (148.4+31 N vs. 101.4+26 N; p=0.011) and 16 (155+30 N vs. 114.9+25 N; p=0.017) weeks after repair, respectively. There were no significant differences between the two groups at each time interval for linear stiffness (15.9+2.7N/mm vs. 15.8+1.3N/mm, p=0.798 and 16.9+4.3N/mm vs. 17.1+3.6N/mm, p=0.848, respectively) and elongation at failure (4.7+1.1 mm vs. 4.7+1.3 mm, p=0.848 and 4.8+1.5 mm vs. 4.9+0.9 mm, p=0.749, respectively). Conclusions: The BMS technique of microfracture on the tuberosity of the repaired chronic rotator cuff tear promotes the dynamic tendon healing with significant ultimate force to failure and apparent microscopic findings.

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