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 (β = 38 N per limb; 95% CI, 28 to 49 N) and less gap formation (β = −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.

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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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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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A “Comma Sign”–Directed Subscapularis Repair in Anterosuperior Rotator Cuff Tears Yields Biomechanical Advantages in a Cadaveric Model

The American Journal of Sports Medicine ◽

10.1177/03635465211031506 ◽

2021 ◽

pp. 036354652110315

Author(s):

Michael Hackl ◽

Eduard Buess ◽

Sandra Kammerlohr ◽

Julia Nacov ◽

Manfred Staat ◽

...

Keyword(s):

Rotator Cuff ◽

Failure Load ◽

Primary Stability ◽

Rotator Cuff Tears ◽

Subscapularis Tendon ◽

Gap Formation ◽

Single Row ◽

Ultimate Failure Load ◽

Ultimate Failure ◽

Comma Sign

Background: Additional stabilization of the “comma sign” in anterosuperior rotator cuff repair has been proposed to provide biomechanical benefits regarding stability of the repair. Purpose: This in vitro investigation aimed to investigate the influence of a comma sign–directed reconstruction technique for anterosuperior rotator cuff tears on the primary stability of the subscapularis tendon repair. Study Design: Controlled laboratory study. Methods: A total of 18 fresh-frozen cadaveric shoulders were used in this study. Anterosuperior rotator cuff tears (complete full-thickness tear of the supraspinatus and subscapularis tendons) were created, and supraspinatus repair was performed with a standard suture bridge technique. The subscapularis was repaired with either a (1) single-row or (2) comma sign technique. A high-resolution 3D camera system was used to analyze 3-mm and 5-mm gap formation at the subscapularis tendon-bone interface upon incremental cyclic loading. Moreover, the ultimate failure load of the repair was recorded. A Mann-Whitney test was used to assess significant differences between the 2 groups. Results: The comma sign repair withstood significantly more loading cycles than the single-row repair until 3-mm and 5-mm gap formation occurred ( P≤ .047). The ultimate failure load did not reveal any significant differences when the 2 techniques were compared ( P = .596). Conclusion: The results of this study show that additional stabilization of the comma sign enhanced the primary stability of subscapularis tendon repair in anterosuperior rotator cuff tears. Although this stabilization did not seem to influence the ultimate failure load, it effectively decreased the micromotion at the tendon-bone interface during cyclic loading. Clinical Relevance: The proposed technique for stabilization of the comma sign has shown superior biomechanical properties in comparison with a single-row repair and might thus improve tendon healing. Further clinical research will be necessary to determine its influence on the functional outcome.

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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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Biomechanical testing of small versus large lesser tuberosity osteotomies: effect on gap formation and ultimate failure load

Journal of Shoulder and Elbow Surgery ◽

10.1016/j.jse.2013.06.024 ◽

2014 ◽

Vol 23 (4) ◽

pp. 470-476 ◽

Cited By ~ 15

Author(s):

Matthew P. Fishman ◽

Matthew D. Budge ◽

James E. Moravek ◽

Mark Mayer ◽

Michael D. Kurdziel ◽

...

Keyword(s):

Failure Load ◽

Biomechanical Testing ◽

Gap Formation ◽

Lesser Tuberosity ◽

Ultimate Failure Load ◽

Ultimate Failure

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Biomechanical comparison between single-row with triple-loaded suture anchor and suture-bridge double-row rotator cuff repair

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-03654-y ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

He-Bei He ◽

Yong Hu ◽

Chuan Li ◽

Cheng-Guo Li ◽

Min-Cong Wang ◽

...

Keyword(s):

Rotator Cuff ◽

Rotator Cuff Repair ◽

Suture Anchor ◽

Biomechanical Properties ◽

Gap Formation ◽

Double Row ◽

Single Row ◽

Dr Method ◽

Ultimate Failure ◽

Cuff Repair

Abstract Background Numerous biomechanical and clinical studies comparing different techniques for rotator cuff repair have been reported, yet universal consensus regarding the superior technique has not achieved. A medially-based single-row with triple-loaded suture anchor (also referred to as the Southern California Orthopedic Institute [SCOI] row) and a suture-bridge double-row (SB-DR) with Push-Locks have been shown to result in comparable improvement in treating rotator cuff tear, yet the biomechanical difference is unknown. The purpose of the current study was to determine whether a SCOI row repair had comparable initial biomechanical properties to a SB-DR repair. Methods Six matched pairs of fresh-frozen cadaveric shoulders with full-thickness supraspinatus tendon tears we created were included. Two different repairs were performed for each pair (SCOI row and SB-DR methods). Specimens were mounted on a material testing machine to undergo cyclic loading, which was cycled from 10 to 100 N at 1 Hz for 500 cycles. Construct gap formation was recorded at an interval of 50 cycles. Samples were then loaded to failure and modes of failure were recorded. Repeated-measures analysis of variance and pair-t test were used for statistical analyses. Results The construct gap formation did not differ between SCOI row and SB-DR repairs (P = 0.056). The last gap displacement was 1.93 ± 0.37 mm for SCOI row repair, and 1.49 ± 0.55 mm for SB-DR repair. The tensile load for 5 mm of elongation and ultimate failure were higher for SCOI row repair compared to SB-DR repair (P = 0.011 and 0.028, respectively). The ultimate failure load was 326.34 ± 11.52 N in the SCOI row group, and 299.82 ± 27.27 N in the SB-DR group. Rotator cuff repair with the SCOI row method failed primarily at the suture- tendon interface, whereas pullout of the lateral row anchors was the primary mechanism of failure for repair with the SB-DR method. Conclusion Rotator cuff repair with the SCOI row method has superior biomechanical properties when compared with the SB-DR method. Therefore, SCOI row repair using a medially-based single-row technique with triple-loaded suture anchor is recommended to improve the initial strength in treating full-thickness rotator cuff tears.

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