Proximal humerus osteolysis after revision rotator cuff repair with bioabsorbable suture anchors

Biodegradable anchors were designed to provide secure fixation while allowing for later resorption and replacement by host tissue. First-generation implants degraded relatively rapidly and caused foreign-body reactions, synovitis, fragmentation, and osteolysis. Newer implants have similar complications. It is not known if the primary cause of the osteolysis is biological (precipitated by breakdown products of the polymer) or mechanical (caused by initial loss of implant stability). Case reports have described glenoid osteolysis around biodegradable suture anchor placement for shoulder stabilization, but up until now, to our knowledge, only 1 case of proximal humerus osteolysis has been reported for these implants. Here we describe a semicrystalline, poly-L-lactic acid bioabsorbable suture anchor failure after revision rotator cuff repair with subsequent humeral tuberosity osteolysis.     

A modified Mason-Allen technique for rotator cuff repair using suture anchors

An adequate restoration of the muscle-tendon-bone unit is essential for a successful outcome after rotator cuff reconstruction. We describe a suture grasping technique for rotator cuff repair using suture anchors that can be performed either arthroscopically or during open rotator cuff refixation. The technique we use is a combination of a mattress and a single suture, thus representing the principles of a Mason-Allen suture technique. The modified Mason-Allen technique for suture anchor repair is easy to perform and provides excellent initial fixation strength allowing durable osteofibroblastic integration of the reinserted cuff.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 19, No 3 (March), 2003: pp 330–333     

Pullout strength of suture anchors used in rotator cuff repair

BACKGROUND: Surgical treatment of rotator cuff tears may be complicated by osteoporosis of the proximal part of the humerus. The purpose of this study was to determine whether pullout strength of suture anchors is affected by the location of the anchor placement and by bone mineral density. We hypothesized that higher bone mineral density is associated with higher pullout strength of suture anchors. METHODS: Peripheral quantitative computed tomography was used to measure total, trabecular, and cortical bone mineral density in different regions of the lesser and greater tuberosities in seventeen cadaveric humeri. Suture anchors were inserted into individual regions and subjected to cyclic loading. Repeated-measures analysis of variance was used to assess differences in bone mineral density and load to failure between regions of interest. Pearson correlation was used to determine the association between bone mineral density and pullout strength of suture anchors. RESULTS: Total, trabecular, and cortical bone mineral densities were an average of 50%, 50%, and 10% higher, respectively, in the proximal part of the tuberosities compared with the distal part (p < 0.01). Within the proximal part of the greater tuberosity, trabecular bone mineral density of the posterior region and cortical bone mineral density of the middle region were, on the average, 25% and 16% higher, respectively, than the densities in the other regions (p < 0.01). Load to failure in the proximal part of the tuberosities was an average of 53% higher than that in the distal part (p < 0.01). The lesser tuberosity showed, on the average, a 32% higher load to failure than did the greater tuberosity (p < 0.01). Within the proximal part of the greater tuberosity, loads to failure in the anterior and middle regions were, on the average, 62% higher than the load to failure in the posterior region (p < 0.01). Overall positive correlations were found between bone mineral density and load to failure (0.65 相似文献   

Arthroscopic biceps tenodesis incorporated into rotator cuff repair using suture anchors

A simple and effective technique is described for incorporating arthroscopic biceps tenodesis into arthroscopic suture anchor rotator cuff repair.     

Arthroscopic rotator cuff repair using a single-row of triple-loaded suture anchors with a modified suture configuration

Achieving an adequate restoration of the muscle–tendon–bone unit and the anatomical footprint is essential for a successful outcome in open and arthroscopic rotator cuff repair. The described suture grasping technique using triple-loaded suture anchors might combine high initial fixation strength with good footprint coverage. It describes two mattress’ stitches medial at the articular margin of the tendon. Additionally, a third mattress stitch is performed laterally to increase footprint contact and avoid dog-ear deformity. The triple-mattress repair is easy to perform and might be a good alternative in either arthroscopic or open rotator cuff repair.     

Osteolysis after rotator cuff repair with bioabsorbable anchors

Purpose  

The current study was designed to evaluate the rate of osteolysis and the clinical and functional outcomes in patients who underwent mini-open rotator cuff repairs using first generation bioabsorbable suture anchors. Our hypothesis was that patients with osteolysis noted on post-repair MRI would have an accompanying decrease in functional and clinical patient outcomes when compared with patients who did not have osteolysis evident on post-repair MRI.     

Arthroscopic revision rotator cuff repair

Rotator cuff repair leads to good and excellent outcomes in most patients. However, structural failure of the repair occurs in a substantial number of cases and can lead to an unsatisfactory result. Several factors have been implicated, including patient-related factors (eg, patient age, tear size) and extrinsic factors (eg, surgeon surgical volume, biomechanical failure). Structural failure requires a detailed patient evaluation to elucidate the cause of persistent symptoms. Function can be maintained despite a recurrent tear; therefore, a recurrent tear alone is not an indication for revision repair. The major indication for revision rotator cuff repair is the persistence of clinical symptoms, despite nonsurgical management, in the absence of substantial risk factors for failure. Although the outcome is poorer than after primary repair, satisfactory results have been reported following revision repair of recurrent rotator cuff tears, particularly with arthroscopic techniques.     

Initial fixation and cyclic loading stability of knotless suture anchors for rotator cuff repair

This study evaluated the resistance to gapping and the mode of failure for 2 knotless suture anchor systems used for rotator cuff repair compared with the performance of a conventional titanium anchor system. Eight matched pairs of fresh-frozen humeri were dissected free of all soft tissues and scanned to measure bone mineral density (BMD). The suture anchor systems tested were the TwinFix 5.0 Titanium (Smith & Nephew, Andover, MA), Bioknotless RC (DePuy Mitek, Norwood, MA), and Magnum (Opus Medical, San Juan Capistrano, CA), and each was inserted into each humerus. Cyclic, tensile loading was applied through the suture loop for 5000 cycles, or until failure, by using a servohydraulic testing machine. Gapping distances, defined as increasing elongation of the bone/anchor/suture system, were continuously measured. Total cycles to failure and mechanism of failure were documented. Mean initial (first cycle) and final (last cycle) gapping distances were 3.81 mm and 5.36 mm for the TwinFix 5.0, 4.02 mm and 5.34 mm for the Bioknotless RC, and 3.56 mm and 4.98 mm for the Magnum anchors. No significant difference was detected among mean gap openings (P > .05). However, the Bioknotless RC had more early failures (5) than the other 2 implants (1 each), approaching significance (P = .07). Trials of the Bioknotless RC that did not fail early were found to have significantly less gap opening than the other 2 systems for both initial (1.89 mm vs 3.82 mm for the TwinFix 5.0 and 3.56 mm for the Magnum) and final (2.00 mm vs 4.68 mm for the TwinFix 5.0 and 4.24 mm for the Magnum) gap opening. BMD was a significant predictor of initial (P = .029) and final (P = .008) gap opening, whereas the site of anchor insertion was a significant predictor of final displacement. The Opus Magnum was comparable with a conventional suture anchor, but the Mitek Bioknotless RC showed a trend toward early failure. Biomechanical analysis of knotless suture anchor systems can demonstrate trends among implants in an experimental setting. Knowledge of these trends could influence implant selection.     

Biomechanical testing of a new knotless suture anchor compared with established anchors for rotator cuff repair

Various suture anchors are available for rotator cuff repair. For arthroscopic application, a knotless anchor was developed to simplify the intra-operative handling. We compared the new knotless anchor (BIOKNOTLESStrade mark RC; DePuy Mitek, Raynham, MA) with established absorbable and titanium suture anchors (UltraSorbtrade mark and Super Revo 5mmtrade mark; ConMed Linvatec, Utica, NY). Each anchor was tested on 6 human cadaveric shoulders. The anchors were inserted into the greater tuberosity. An incremental cyclic loading was performed. Ultimate failure loads, anchor displacement, and mode of failure were recorded. The anchor displacement of the BIOKNOTLESStrade mark RC (15.3 +/- 5.3 mm) after the first cycle with 75 N was significantly higher than with the two other anchors (Super Revo 2.1 +/- 1.6 mm, UltraSorb: 2.7 +/- 1.1 mm). There was no significant difference in the ultimate failure loads of the 3 anchors. Although the Bioknotlesstrade mark RC indicated comparable maximal pullout strength, it bares the risk of losing contact between the tendon-bone-interface due to a significantly higher system displacement. Therefore, gap formation between the bone and the soft tissue fixation jeopardizes the repair. Bioknotlesstrade mark RC should be used in the lateral row only when a double row technique for rotator cuff repair is performed, and is not appropriate for rotator cuff repair if used on its own.     

Increasing the insertion depth of suture anchors for rotator cuff repair does not improve biomechanical stability

The purpose of this study was to evaluate whether deeper-than-recommended insertion of a suture anchor within the rotator cuff footprint of human cadaveric humeri affects fixation characteristics. Metallic 5-mm screw-in anchors loaded with a single No. 2 suture were placed in the infraspinatus footprint of 8 human cadaveric humeri at standard and deep depths. Specimens were cyclically loaded from 10 to 45 N for 500 cycles and then loaded to failure. Cylic displacement, failure load, and failure mode were compared. All deep anchors became flush within a few cycles, and both anchor depths displaced and rotated at the bone surface. Displacement of the deep anchors was significantly greater than that of standard anchors. There was no difference in failure load. Cyclic testing showed significant displacement, regardless of anchor position, possibly leading to gap formation of the repair. Deep placement of suture anchors for increased purchase caused greater displacement and is not recommended.     

Biomechanical analysis of bioabsorbable suture anchors for rotator cuff repair using osteoporotic and normal bone models

BackgroundThis study aimed to compare the failure load of suture anchors used in rotator cuff repair between normal and osteoporotic bone models.MethodsA total of 16 anchors made from metal (TwinFix Ti 5.0 or 6.5 mm, Corkscrew FT 4.5, 5.5, or 6.5 mm), polyether ether ketone (HEALICOIL PK [HC-PK] 4.5 or 5.5 mm, SwiveLock PK 4.75 or 5.5 mm), or bioabsorbable material (HEALICOIL RG [HC-RG] 4.75 or 5.5 mm, Corkscrew Bio 4.75, 5.5, or 6.5 mm, SwiveLock BC 4.75 or 5.5 mm) were included. Moreover, 10- and 5-pounds per cubic foot (pcf) Sawbone® models were set as normal and osteoporotic cancellous bone models, respectively. Pullout testing was performed in parallel to the insertion axis at a displacement rate of 12.5 mm/s using a universal testing machine. To evaluate the change in failure load between the two Sawbone® models with different densities, the remaining failure load ratio (RFLR) was defined as the ratio of the failure load in 10 pcf to that in 5 pcf.ResultsIn the 10-pcf Sawbone®, TwinFix Ti 6.5 mm showed the highest mean failure load (304.0 ± 15.2 N). In the 5-pcf Sawbone® model, HC-PK 5.5 mm showed the highest failure load (146.3 ± 5.8 N). Among anchors with the same diameter, HC-PK and HC-RG showed a significantly higher failure load than other anchors in the 10- and 5-pcf Sawbone® models. HC-PK 5.5 mm (62.1%) and HC-PK 4.5 mm (51.1%) have the highest RFLR among anchors with the same diameter.ConclusionsHC-PK and HC-RG showed higher failure load than the other anchors in both normal and osteoporotic bone models, except for TwinFix Ti 6.5 mm in the 10-pcf Sawbone® model. Based on our results, bioabsorbable anchors had sufficient failure load for rotator cuff repair in addition to bioabsorbability.     

Use of direct introduction of allograft anchors for rotator cuff repair

Allograft anchors that can be inserted directly through the greater tuberosity were developed, tested, and used clinically for rotator cuff repair. Mechanical strength testing was performed, and allograft anchors were used in 63 consecutive procedures by a single surgeon. The insertion technique involved directly impacting the allograft anchor through the greater tuberosity without drilling a hole in the bone. Results of mechanical testing showed strengths comparable with those of other anchors (155.8 N), and the anchors locked consistently. This direct insertion technique saves time and procedural steps over traditional anchor insertion techniques while using an allograft anchor that reincorporates into host bone.     

Current concepts review: revision rotator cuff repair

Failed rotator cuff repair may be caused by surgical complications, diagnostic errors, technical errors, failure to heal, and traumatic failure. Revision rotator cuff repair is made technically more difficult by poor tissue quality, tissue adhesions, and retained suture and suture anchor material. Historically, open revision rotator cuff repair yields inferior results compared with primary rotator cuff repair; however, more recent studies show 52% to 69% satisfactory results in small-sized or medium-sized tears. Arthroscopic revision rotator cuff repair yields greater than 60% good or excellent results. Poor tissue quality, detachment of the deltoid origin, and multiple previous surgeries are risk factors for poor results in revision rotator cuff repair.     

Pullout strength of all suture anchors in the repair of rotator cuff tears: a biomechanical study

Purpose

We evaluated the biomechanical strength of two all suture anchors (ASA) of reduced diameter (1.4 mm) and compared them with the standard screw anchor (SA) with larger diameter (5.5 mm) used in rotator cuff tears.

Methods

We conducted 30 uniaxial vertical pullout tests using Material Testing System Instron 5566A until failure of the anchorage defined as rupture of the threads or anchor or detachment of the anchor. Anchor fixation was on tuberosities of fresh bovine humerus bone. ASAs were spaced four millimetres apart and were compared with a control SA implanted on the same greater tubercle at two centimetres. The tests were all performed at room temperature in a dry environment. Tensile loads (10 mm/min) were applied parallel to the axis of insertion. A preloading of 10 N was used to overcome loading artifacts of the test sample at the beginning of the test.

Results

Student’s t test showed no statistically significant difference between anchors in terms of load to failure (ASA: force 265.06 ± 87.25 N versus SA : 325.35 ± 113.46 N; p = 0.09) and mean elongation at rupture (ASA : 23 ± 7 mm versus SA : 21 ± 6 mm; p = 0.46).

Conclusions

In vitro, this experimental study showed no statistically significant difference in pullout strength and displacement between ASA and SA at a chosen level of significance (p < 0.05).     

Mid-term clinical outcome following rotator cuff repair using all-suture anchors

BackgroundSymptomatic rotator cuff tears can cause significant pain and functional disturbance, with associated financial ramifications. Non-surgical management should always be considered initially, however if recalcitrant to these measures surgical intervention may involve open, arthroscopic-assisted mini-open or arthroscopic rotator cuff repairs. The use of trans-osseous sutures and suture anchors has been reported with good results, with no significant differences if the repair remains intact or recurrent tears occur. The role of traditional suture anchors has been assessed clinically and biomechanically, however there have been reports of pull out, anchor material found within joint and concerns with the amount of bone loss. The all suture anchor (ASA) is proposed to address these concerns with encouraging cadaveric, biomechanical results to date.MethodsThe two senior authors performed 31 arthroscopic rotator cuff repairs using ASA with a double row technique at the two study centres’. The patients were reviewed in clinic at one month, three months, 6 months and a year postoperatively. The patients were assessed with the Constant score and clinical range of motion of the shoulder in abduction, forward flexion, external rotation and internal rotation. The surgical technique and rehabilitation was the same for both surgeons.ResultsAt a mean follow up of 10.2 months (range 3–12 months) the mean constant score was 77.1 (range 35–90), with a mean abduction of 139.6° (range 30–180°), external rotation of 43.4° (range 20–80°), and internal rotation to lumbar vertebrae 3–4 (range buttock to lumbar vertebra 1). There has been one re-rupture to date.ConclusionsThe functional and clinical results in our study are comparable to those reported in literature using standard anchors.     

关节镜下缝合锚钉加骨隧道缝合方法修复肩袖损伤

目的 探讨肩关节镜下缝合锚钉加骨隧道缝合方法治疗肩袖损伤的手术方法、技巧和疗效.方法 2007年2月-2009年2月,对32例不同类型的肩袖损伤患者,采用关节镜下缝合锚钉加肱骨大结节骨隧道缝合的方法修复肩袖.其中25例全层撕裂,5例滑囊侧部分撕裂,2例关节侧部分撕裂.16例发生于优势侧.术前均拍摄肩关节正位、肩袖出口位X线片,其中11例行MRI检查,21例行MRA检查.全部患者均行肩峰成形与肩峰下滑囊切除,肩袖修复采用单排锚钉固定加经骨隧道穿线缝合18例、双排锚钉加经骨隧道穿线固定14例.按照UCLA肩关节评分标准进行术前和术后功能评估.结果 32例患者获得3～23个月的随访,平均13.4个月.按照UCLA肩关节评分:术前平均为13.3分,术后为33.1分;其中优23例,良9例.术后21例疼痛完全消失,5例偶感轻微疼痛或不适,6例剧烈运动或特殊动作疼痛.24例肩关节活动完全正常.主动前屈及外展角度>150°26例,90°～120°6例.术后前屈及外展肌力M_5 25例,M_47例.所有患者最终对手术效果满意.结论 缝合锚钉加骨隧道穿线缝合是修复肩袖撕裂较好的方法,该技术固定牢靠、保证了肩袖-骨的正常愈合,特别适用于骨质疏松或翻修的病例,值得推广.