Biomechanical evaluation of rotator cuff repairs in a sheep model: suture anchors using arthroscopic Mason-Allen stitches compared with transosseous sutures using traditional modified Mason-Allen stitches.
ABSTRACT The optimal method for rotator cuff repair of the shoulder is not yet known. The aim of this study was to compare the time-dependent biomechanical properties of the traditional open transosseous suture technique and modified Mason-Allen stitches (group 1) versus the double-loaded suture anchors technique and so-called arthroscopic Mason-Allen stitches (group 2) in rotator cuff repair.
Eighteen adult female sheep were randomized into two groups: in an open approach in which the released infraspinatus tendon was repaired with group 1, and with group 2. Animals were sacrificed at 6, 12, or 26 weeks; shoulders were harvested and magnetic resonance imaging was performed. Eight untreated contralateral shoulders served as controls. Tendons of 16 additional unpaired cadaver shoulder joints of adult female sheep were identically treated for analysis at time zero. In a biomechanical evaluation all specimens were loaded to failure at a constant displacement rate using a standard universal testing machine. The load-to-failure and stiffness of the healed bone-tendon interface were calculated.
Magnetic resonance imaging analysis showed cuff integrity in all cases, and no evidence of foreign body reaction to the anchors. Load-to-failure and stiffness data did not indicate any significant difference between the two treatment groups, neither at 6 weeks nor at 12 or 26 weeks. However, at time zero the group 2 had a higher load-to-failure in comparison to the group 1 (P<0.010), but there was no difference for the stiffness (P<0.121).
This in vivo study showed that, postoperatively, the group 2 technique provides superior stability and after healing would gain strength comparable to the group 1 technique.
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ABSTRACT: Neben vielfältigen Faktoren wie Lebensalter, Durchblutung, Größe sowie Alter der Rotatorenmanschettenruptur und fettiger Infiltration der Muskulatur ist die Refixationstechnik der Sehne ein wichtiger Faktor für eine erfolgreiche Behandlung. In den letzten Jahren hat sich eine breite Hinwendung zu arthroskopischen Operationstechniken vollzogen. Die schnelle Ausbreitung dieser Verfahren war nur durch komplette Neuentwicklungen der Refixationstechnik möglich.Wir stellen die wichtigsten Faktoren der aktuellen arthroskopischen Fixationstechnik der Rotatorenmanschette zusammen. Neben den verwendbaren Fäden und der Art der Nahtanker werden verschiedene Anordnungen der Nahtanker diskutiert. Biomechanisch bieten doppelreihige Nahtankeranordnungen bessere Voraussetzungen als einreihige, jedoch ist aus klinischer Sicht bisher kein klarer Vorteil nachgewiesen. Falls technisch möglich, bietet eine Doppelreihenrekonstruktion mit lateraler Verspannung der Fäden heute gute biomechanische Voraussetzungen, um eine verbesserte Einheilung der Sehne zu erreichen.Der Orthopäde 01/2011; 40(1). · 0.67 Impact Factor
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ABSTRACT: In rotator cuff repair, strong and long-lasting suturing techniques that do not require additional implants are needed. This study examines the ultimate load to failure and the Young's modulus at the suture-tendon interface for a novel single-loop knot stitch and double-loop knot stitch. These values are compared to those of the modified Mason-Allen stitch. Twenty-four infraspinatus muscles with tendons were dissected from porcine shoulders (twelve Goettingen minipigs). The preparations were randomly allocated to three groups of eight samples. Load-to-failure testing of the single-loop knot stitch, the double-loop knot stitch and the mMAS were performed using a Zwick 1446 universal testing machine (Zwick-Roell AG, Ulm, Germany). The highest ultimate load to failure for the three techniques occurred with the double-loop knot stitch with a median value of 382.2 N (range 291.8-454.2 N). These values were significantly higher than those of the single-loop knot stitch, which had a median value of 259.5 N (range 139.6-366.3 N) and the modified Mason-Allen stitch, which had a median value of 309.3 N (range 84.55-382.9 N). The values of the single-loop knot stitch and the modified Mason-Allen stitch did not differ significantly. Regarding the Young's modulus, no significant differences were found between the double-loop knot stitch with a median value of 496.02 N/mm² (range 400.4-572.6 N/mm²) and the modified Mason-Allen stitch with 498.5 N/mm² (range 375.5-749.2 N/mm²) with respect to the stiffness of the suture-tendon complex. The median value for the Young's modulus of the single-loop knot stitch of 392.1 N/mm² (range 285.7-510.6 N/mm²) was significantly lower than those of the double-loop knot stitch and modified Mason-Allen stitch. This in vitro animal study demonstrated that both the single-loop knot stitch and the double-loop knot stitch have excellent ultimate load-to-failure properties when used for rotator cuff repair. The introduced single-loop knot stitch and double-loop knot stitch offer an alternative to other common used stitch techniques in rotator cuff repair.Knee Surgery Sports Traumatology Arthroscopy 04/2014; 23(5). DOI:10.1007/s00167-014-2976-7 · 2.84 Impact Factor
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ABSTRACT: Tendon disorders are common and lead to significant disability, pain, healthcare cost, and lost productivity. A wide range of injury mechanisms exist leading to tendinopathy or tendon rupture. Tears can occur in healthy tendons that are acutely overloaded (e.g., during a high speed or high impact event) or lacerated (e.g., a knife injury). Tendinitis or tendinosis can occur in tendons exposed to overuse conditions (e.g., an elite swimmer's training regimen) or intrinsic tissue degeneration (e.g., age-related degeneration). The healing potential of a torn or pathologic tendon varies depending on anatomic location (e.g., Achilles vs. rotator cuff) and local environment (e.g., intrasynovial vs. extrasynovial). Although healing occurs to varying degrees, in general healing of repaired tendons follows the typical wound healing course, including an early inflammatory phase, followed by proliferative and remodeling phases. Numerous treatment approaches have been attempted to improve tendon healing, including growth factor- and cell-based therapies and rehabilitation protocols. This review will describe the current state of knowledge of injury and repair of the three most common tendinopathies– flexor tendon lacerations, Achilles tendon rupture, and rotator cuff disorders– with a particular focus on the use of animal models for understanding tendon healing.. This article is protected by copyright. All rights reservedJournal of Orthopaedic Research 01/2015; 33(6). DOI:10.1002/jor.22806 · 2.97 Impact Factor