Tendon-bone interface motion in transosseous suture and suture anchor rotator cuff repair techniques

BACKGROUND: Although many studies involving rotator cuff repair fixation have focused on ultimate fixation strength and ability to restore the tendon's native footprint, no studies have characterized the stability of the repair with regard to motion between the tendon and repair site footprint. HYPOTHESIS: Suture anchor fixation for rotator cuff repair has greater interface motion between tendon and bone than does transosseous suture fixation. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve fresh-frozen human cadaveric shoulders were tested in a custom device to position the shoulder in internal and external rotations with simulated supraspinatus muscle loading. Tendon motion relative to the insertional footprint on the greater tuberosity was determined optically using a digital camera rigidly connected to the humerus, with the humerus positioned at 60 degrees of internal rotation and 60 degrees of external rotation. Testing was performed for the intact tendon, a complete supraspinatus tear, a suture anchor repair, and a transosseous tunnel repair. RESULTS: Difference in tendon-bone interface motion when compared with the intact tendon was 7.14 +/- 3.72 mm for the torn rotator cuff condition, 2.35 +/- 1.26 mm for the suture anchor repair, and 0.02 +/- 1.18 mm for the transosseous suture repair. The transosseous suture repair demonstrated significantly less motion when compared with the torn rotator cuff and suture anchor repair conditions (P < .05). CONCLUSION: Transosseous suture repair compared with suture anchor repair demonstrated superior tendon fixation with reduced motion at the tendon-to-tuberosity interface. CLINICAL RELEVANCE: Development of new fixation techniques for arthroscopic and open rotator cuff repairs should attempt to minimize interface motion of the tendon relative to the tuberosity.     

Arthroscopic single-row versus double-row suture anchor rotator cuff repair

BACKGROUND: Recurrent defects after open and arthroscopic rotator cuff repair are common. Double-row repair techniques may improve initial fixation and quality of rotator cuff repair. PURPOSE: To evaluate the load to failure, cyclic displacement, and anatomical footprint of 4 arthroscopic rotator cuff repair techniques. HYPOTHESIS: Double-row suture anchor repair would have superior structural properties and would create a larger footprint compared to single-row repair. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty fresh-frozen cadaveric shoulders were randomly assigned to 4 arthroscopic repair techniques. The repair was performed as either a single-row technique or 1 of 3 double-row techniques: diamond, mattress double anchor, or modified mattress double anchor. Angle of loading, anchor type, bone mineral density, anchor distribution, angle of anchor insertion, arthroscopic technique, and suture type and size were all controlled. Footprint length and width were quantified before and after repair. Displacement with cyclic loading and load to failure were determined. RESULTS: There were no differences in load to failure and displacement with cyclic loading between the single-row repair and each double-row repair. All repair groups demonstrated load to failure greater than 250 N. A significantly greater supraspinatus footprint width was seen with double-row techniques compared to single-row repair. CONCLUSIONS: The single-row repair technique was similar to the double-row techniques in load to failure, cyclic displacement, and gap formation. The double-row anchor repairs consistently restored a larger footprint than did the single-row method. CLINICAL RELEVANCE: The arthroscopic techniques studied have strong structural properties that approached the reported performance of open repair techniques. Double-row techniques provide a larger footprint width; although not addressed by this study, such a factor may improve the biological quality of repair.     

异体骨锚钉双排固定法修复肩袖损伤

目的 探讨异体皮质骨锚钉双排固定法修复肩袖损伤的价值.方法 关节镜监视下,采用同种异体皮质骨锚钉双排同定法修复肩袖损伤16例.其中男10例,女6例;年龄32～58岁,平均44岁.按Bigliani肩袖损伤分类法,小撕裂6例,中度撕裂8例,大撕裂2例.关节镜下肩袖清理和肩峰成形后,采用带线异体骨锚钉植入肱骨大结节肩袖附着处,双根缝线垂直褥式缝合冈上肌腱,分别打结固定后,将缝线交叉牵引到在肱骨大结节预制的骨道处,将缝线穿入另一个骨锚钉孔内并击入骨道内.4根缝线交叉呈网状覆盖撕裂的冈上肌腱由骨锚钉固定.根据撕裂创面大小决定骨锚钉植入数量.结果 所有患者术后得到随访,时间6～23个月,平均14个月.术后疼痛症状均消失,肩关节功能采用美国加州洛杉矶大学(UCLA)功能评分标准评估,术前(20.5±5.6)分,术后(33.4±5.8)分.优10例,良5例,可1例.术后肩关节稳定性良好,无锚钉拔出和损伤复发.结论 异体骨锚钉双排同定法修复肩袖损伤,镜下手术操作方便,骨锚钉嵌入固定牢靠,增加肩袖组织与骨创面的接触面积,有利于肩袖愈合.骨锚钉生物固定,无异物存留,价格低廉.     

Pullout strength of suture anchors in comparison with transosseous sutures for rotator cuff repair

Suture anchors are increasingly gaining importance in rotator cuff surgery. This means they will be gradually replacing transosseous sutures. The purpose of this study was to compare the stability of transosseous sutures with different suture anchors with regard to their pullout strength depending on bone density. By means of bone densitometry (CT scans), two groups of human humeral head specimens were determined: a healthy and a osteopenic bone group. Following anchor systems were being tested: SPIRALOK™ 5.0 mm (resorbable, DePuy Mitek), Super Revo 5 mm (titanium, Linvatec), UltraSorb (resorbable, Linvatec) and the double U-sutures with Orthocord™ USP 2 (partly resorbable, DePuy Mitek) and Ethibond Excel 2 (non-resorbable, Ethicon). The suture anchors/double U-sutures were inserted in the greater tuberosity 12 times. An electromechanical testing machine was used for cyclic loading with power increasing in stages. We recorded the ultimate failure loads, the system displacements and the modes of failure. The suture anchors tended to bring about higher ultimate failure loads than the transosseous double U-sutures. This difference was significant in the comparison of the Ethibond suture and the SPIRALOK 5.0 mm—both in healthy and osteopenic bone. Both the suture materials and the SPIRALOK 5.0 mm showed a significant difference in pullout strength on either healthy or osteopenic bone; the titanium anchor SuperRevo 5 mm and the tilting anchor UltraSorb did not show any significant difference in healthy or osteopenic bone. There was no significant difference concerning system displacement (healthy and osteopenic bone) between the five anchor systems tested. The pullout strength of transosseous sutures is neither on healthy nor on osteopenic bone higher than that of suture anchors. Therefore, even osteopenic bone does not constitute a valid reason for the surgeon to perform open surgery by means of transosseous sutures. The choice of sutures in osteopenic bone is of little consequence anyway since it is mostly the bone itself which is the limiting factor.     

Evaluation of BioCorkscrew and Bioknotless RC suture anchor rotator cuff repair fixation: an in vitro biomechanical study

This in vitro biomechanical study used cadaveric specimens to compare the rotator cuff repair fixation provided by BioCorkscrew and Bioknotless RC suture anchors. Three cm wide by 1-cm long full-thickness supraspinatus defects were repaired using either two BioCorkscrew suture anchors with combined vertical and horizontal mattress sutures (n = 7) or three Bioknotless RC suture anchors with simple sutures (n = 7). Therefore, the BioCorkscrew suture anchor group had two sutures per anchor (four total sutures), while the Bioknotless RC suture anchor group had one suture per anchor (three total sutures). Two-phase cyclic (5–100 N, 1,000 cycles and 5–180 N, 2,000 cycles) and load to failure tests (31 mm/s) were performed. Non-parametric statistics were used to compare group differences (P < 0.05). All of the BioCorkscrew group specimens (seven of seven) completed the two phase cyclic test regimen without failure or gapping ≥ 5 mm, compared to only three of seven of the Bioknotless RC group (Fisher’s Exact test = 0.03). Groups did not differ for repair site gapping during the 5–100 N cyclic test phase (Fisher’s Exact test = 0.77), however more of the Bioknotless RC group displayed gapping ≥ 5 mm during the 5–180 N cyclic test phase than the BioCorkscrew group (P = 0.02). The BioCorkscrew group also displayed greater yield load during load to failure testing (492.2 ± 204 N vs. 296.4 ± 155 N, P = 0.03). In this in vitro biomechanical study, the BioCorkscrew group with combined vertical and horizontal mattress sutures displayed greater cyclic test survival, less repair site gapping, and superior yield load compared to the Bioknotless RC group with simple sutures. These results in human cadaveric rotator cuff-humerus specimens suggest better immediate post-operative repair site strength and a reduced need for post-operative restrictions. Clinical studies are needed to determine how these rotator cuff repair modes withstand the forces of early rehabilitation and activities of daily living that potentially influence patient outcomes.     

Hamstring graft fixation in MPFL reconstruction at the patella using a transosseous suture technique

Controversy still exists about fixation methods of a hamstring graft to the patella in case of medial patellofemoral ligament (MPFL) reconstruction. This article presents a surgical technique of hamstring tendon graft fixation to the anatomical MPFL insertion on the patella using transosseous sutures. A superficial bony sulcus is created at the anatomical MPFL insertion site on the medial patellar rim with a bur. A looped hamstring tendon graft is fixed to this superficial sulcus by a pair of nonresorbable transosseous sutures passed across the patella. The retinaculum is sutured on top of the hamstring tendon graft at the level of the patella for additional fixation. The technique avoids bone tunnels as well as hardware at the patella. It reduces the risk of intraoperative or postoperative patella fracture or implant-related complications. The stable transosseous fixation technique allows for early rehabilitation.     

Biomechanical comparison of a single-row versus double-row suture anchor technique for rotator cuff repair

BACKGROUND: Reestablishment of the native footprint during rotator cuff repair has been suggested as an important criterion for optimizing healing potential and fixation strength. HYPOTHESIS: A double-row rotator cuff footprint repair will demonstrate superior biomechanical properties compared with a single-row repair. STUDY DESIGN: Controlled laboratory study. METHODS: In 9 matched pairs of fresh-frozen cadaveric shoulders, the supraspinatus tendon from 1 shoulder was repaired with a double-row suture anchor technique: 2 medial anchors with horizontal mattress sutures and 2 lateral anchors with simple sutures. The tendon from the contralateral shoulder was repaired using a single lateral row of 2 anchors with simple sutures. Each specimen underwent cyclic loading from 10 to 180 N for 200 cycles, followed by tensile testing to failure. Gap formation and strain over the footprint area were measured using a video digitizing system; stiffness and failure load were determined from testing machine data. RESULTS: Gap formation for the double-row repair was significantly smaller (P < .05) when compared with the single-row repair for the first cycle (1.67 +/- 0.75 mm vs 3.10 +/- 1.67 mm, respectively) and the last cycle (3.58 +/- 2.59 mm vs 7.64 +/- 3.74 mm, respectively). The initial strain over the footprint area for the double-row repair was nearly one third (P < .05) the strain of the single-row repair. Adding a medial row of anchors increased the stiffness of the repair by 46% and the ultimate failure load by 48% (P < .05). CONCLUSION: Footprint reconstruction of the rotator cuff using a double-row repair improved initial strength and stiffness and decreased gap formation and strain over the footprint when compared with a single-row repair. CLINICAL RELEVANCE: To achieve maximal initial fixation strength and minimal gap formation for rotator cuff repair, reconstructing the footprint attachment with 2 rows of suture anchors should be considered.     

Contact area and pressure in suture bridge rotator cuff repair using knotless lateral anchors

Purpose

To evaluate whether the use of knotless lateral anchors in a suture bridge construct produces better contact area and pressure parameters than a suture bridge construct with standard lateral anchors that require knots or a double-row repair. The hypothesis was that knotless lateral anchors would produce better contact area and pressure parameters than the other two constructs.

Methods

A total of fifteen matched pairs of cadaveric shoulders were divided into three groups. In Group 1, a suture bridge using knotless anchors for the lateral row was performed on five shoulders. A suture bridge using standard lateral row anchors that require knots was performed on the contralateral shoulders. In Group 2, suture bridge with knotless lateral row anchors was compared with double-row repair. In Group 3, suture bridge using standard lateral row anchors was compared with double-row repair. The contact conditions of the rotator cuff footprint were measured using pressure-sensitive film.

Results

There were no statistically significant differences between any of the techniques regarding contact area F(2, 15.7) = 3.09, P = 0.07 or mean contact pressure F(2, 15.1) = 2.35, P = 0.12. A post hoc power analysis suggests differences between techniques are likely less than 91–113 mm² for area and 0.071-0.089 N for pressure.

Conclusions

The use of knotless anchors in the lateral row of a suture bridge repair did not increase the footprint contact area or contact pressure when compared to a suture bridge repair requiring knots laterally or to a double-row repair.     

Arthroscopic footprint reconstruction of a bone cyst-associated rotator cuff tear

Arthroscopic treatment of a symptomatic rotator cuff tear is problematic when the tear is associated with a large bone cyst. We describe procedure of arthroscopic bone grafting in the bone cyst and footprint reconstruction of the rotator cuff tear using a suture–bridge technique.     

Arthroscopic footprint reconstruction of bursal-side delaminated rotator cuff tears using the suture-bridge technique

For a bursal-side retracted laminated rotator cuff tear, simple repair of the retracted bursal-side rotator cuff might be insufficient because the repaired tendon could remain as an intratendinous tear of the rotator cuff. We present a repair method for intratendinous rotator cuff tears using the suture-bridge technique. We believe that this method helps to preserve the remnant rotator cuff tendon without tissue damage and restores the normal rotator cuff footprint in bursal-side delaminated rotator cuff tears.     

Equivalent clinical results of arthroscopic single-row and double-row suture anchor repair for rotator cuff tears: a randomized controlled trial

BACKGROUND: Restoring the anatomical footprint may improve the healing and mechanical strength of repaired tendons. A double row of suture anchors increases the tendon-bone contact area, reconstituting a more anatomical configuration of the rotator cuff footprint. HYPOTHESIS: There is no difference in clinical and imaging outcome between single-row and double-row suture anchor technique repairs of rotator cuff tears. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: The authors recruited 60 patients. In 30 patients, rotator cuff repair was performed with a single-row suture anchor technique (group 1). In the other 30 patients, rotator cuff repair was performed with a double-row suture anchor technique (group 2). RESULTS: Eight patients (4 in the single-row anchor repair group and 4 in the double-row anchor repair group) did not return at the final follow-up. At the 2-year follow-up, no statistically significant differences were seen with respect to the University of California, Los Angeles score and range of motion values. At 2-year follow-up, postoperative magnetic resonance arthrography in group 1 showed intact tendons in 14 patients, partial-thickness defects in 10 patients, and full-thickness defects in 2 patients. In group 2, magnetic resonance arthrography showed an intact rotator cuff in 18 patients, partial-thickness defects in 7 patients, and full-thickness defects in 1 patient. CONCLUSION: Single- and double-row techniques provide comparable clinical outcome at 2 years. A double-row technique produces a mechanically superior construct compared with the single-row method in restoring the anatomical footprint of the rotator cuff, but these mechanical advantages do not translate into superior clinical performance.     

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.