Rotator cuff repair with bioabsorbable screws: An in vivo and ex vivo investigation

Purpose: The purpose of this study was to evaluate in vivo the clinical outcomes of rotator cuff repairs with bioabsorbable screws compared with metal suture anchors, and to compare the ex vivo initial load to failure of rotator cuff repairs using 3 different bioabsorbable screws, suture anchors, and transosseous sutures. Type of Study: In vivo clinical outcomes investigation, and ex vivo biomechanical study. Methods: Three cohorts of patients with rotator cuff tears that measured less than 4 cm², were sequentially repaired with Mitek Rotator Cuff QuickAnchors (Mitek Surgical Products, Norwood, MA) (n = 9), Arthrex Headed Bio-Corkscrews (n = 9) (Arthrex, Naples, FL), and Mitek Rotator Cuff QuickAnchors (n = 9). Patients were systematically assessed with a specific shoulder questionnaire and 23 shoulder tests performed preoperatively and at 1 and 6 weeks, 3 and 6 months, and 1 year postoperatively. A correlative ex vivo biomechanical study was performed on 53 ovine shoulders to evaluate the initial failure load properties of bioabsorbable screws compared with fixation with suture anchors and transosseous sutures. Results: In the in vivo portion of the study, the cohort treated with the Headed Bio-Corkscrew demonstrated no improvement on any measured parameter until 1-year after rotator cuff repair. In contrast, shoulders repaired with Mitek Rotator Cuff QuickAnchors demonstrated improved overall shoulder function as early as 6 weeks postoperatively (P =.002), had a better constant score at 1-year after repair (88 ± 9 v 73 ± 17; P =.016), and a lower rate of revision rotator cuff repair (P =.029). In the ex vivo portion of the study, the bioabsorbable headed screws, Headed Bio-Corkscrew (100 ± 30 N) and BioTwist (76 ± 35 N), had inferior initial failure load properties compared with suture anchors (140 ± 36 N) and transosseous sutures (147 ± 68 N). In contrast, the BioCuff (190 ± 56 N), a bioabsorbable implant that used a screw and serrated washer design, had equivalent initial failure load properties as the suture repairs. Conclusions: This investigation had poorer early outcomes, a lower shoulder functional score 1-year after repair, and a higher rate of repeat surgery in patients who had their rotator cuff repaired with a bioabsorbable screw than in patients who had their shoulders repaired with a standard metal suture anchor. Furthermore, the biomechanical testing demonstrated a lower tensile load to failure in the tendons repaired with a simple screw design compared to suture anchors with a mattress stitch. Of note, the implant that used a screw and washer design demonstrated a greater ability to resist initial tensile load.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 19, No 3 (March), 2003: pp 239–248     

Does an Arthroscopic Suture Bridge Technique Maintain Repair Integrity?: A Serial Evaluation by Ultrasonography

Biomechanical studies suggest a suture bridge technique enhances rotator cuff tendon footprint contact area, holding strength, and mean contact pressure. Based on these studies, we asked whether (1) the suture bridge technique would provide a high rate of cuff integrity after surgery, (2) the status of the repaired cuff would change with time, (3) preoperative factors could predict postoperative cuff integrity, and (4) patients with retears had less favorable pain, functional scores, range of motion (ROM), and muscle strength compared with those with intact repairs. We prospectively followed 78 patients with arthroscopic repairs in whom we used the suture bridge technique. The integrity of the rotator cuff repair was determined using ultrasonographic evaluation at 4.5 and 12 months after surgery. Ultrasonography revealed intact cuffs in 91% at 4.5 months postoperatively, all of which were maintained at the 12-month followup. Failure rates were 17.6% (three of 17) for massive tears, 11.1% (two of 18) for large tears, 6.3% (two of 32) for medium tears, and no failures for small tears. Preoperative fatty degeneration of the supraspinatus muscle was a strong predictor of cuff integrity. We found no correlation between the integrity and clinical outcomes except for a temporary decrease of abduction strength at 6 months. Arthroscopic repair using suture bridge technique can achieve a low retear rate in shoulders treated for rotator cuff tears, but the occurrence of retear did not influence the outcome.     

The outcome and structural integrity of arthroscopic rotator cuff repair with use of the double-row suture anchor technique

BACKGROUND: The reported rate of failure after arthroscopic rotator cuff repair has varied widely. The influence of the repair technique on the failure rates and functional outcomes after open or arthroscopic rotator cuff repair remains controversial. The purpose of the present study was to evaluate the functional and anatomic results of arthroscopic rotator cuff repairs performed with the double-row suture anchor technique on the basis of computed tomography or magnetic resonance imaging arthrography in order to determine the postoperative integrity of the repairs. METHODS: A prospective series of 105 consecutive shoulders undergoing arthroscopic double-row rotator cuff repair of the supraspinatus or a combination of the supraspinatus and infraspinatus were evaluated at a minimum of two years after surgery. The evaluation included a routine history and physical examination as well as determination of the preoperative and postoperative strength, pain, range of motion, and Constant scores. All shoulders had a preoperative and postoperative computed tomography arthrogram (103 shoulders) or magnetic resonance imaging arthrogram (two shoulders). RESULTS: There were thirty-six small rotator cuff tears, forty-seven large isolated supraspinatus or combined supraspinatus and infraspinatus tendon tears, and twenty-two massive rotator cuff tears. The mean Constant score (and standard deviation) was 43.2+/-15.1 points (range, 8 to 83 points) preoperatively and 80.1+/-11.1 points (range, 46 to 100 points) postoperatively. Twelve of the 105 repairs failed. Intact rotator cuff repairs were associated with significantly increased strength and active range of motion. CONCLUSIONS: Arthroscopic repair of a rotator cuff tear with use of the double-row suture anchor technique results in a much lower rate of failure than has previously been reported in association with either open or arthroscopic repair methods. Patients with an intact rotator cuff repair have better pain relief than those with a failed repair. After repair, large and massive rotator cuff tears result in more postoperative weakness than small tears do.     

Rotator cuff repair with a novel mesh suture: An ex vivo assessment of mechanical properties

Surgical repair is a common treatment for rotator cuff tear; however, the retear rate is high. A high degree of suture repair strength is important to ensure rotator cuff integrity for healing. The purpose of this study was to compare the mechanical performance of rotator cuffs repaired with a mesh suture versus traditional polydioxanone suture II and FiberWire sutures in a canine in vitro model. Seventy‐two canine shoulders were harvested. An infraspinatus tendon tear was created in each shoulder. Two suture techniques—simple interrupted sutures and two‐row suture bridge—were used to reconnect the infraspinatus tendon to the greater tuberosity, using three different suture types: Mesh suture, polydioxanone suture II, or FiberWire. Shoulders were loaded to failure under displacement control at a rate of 20 mm/min. Failure load was compared between suture types and techniques. Ultimate failure load was significantly higher in the specimens repaired with mesh suture than with polydioxanone suture II or FiberWire, regardless of suture technique. There was no significant difference in stiffness among the six groups, with the exception that FiberWire repairs were stiffer than polydioxanone suture II repairs with the simple interrupted technique. All specimens failed by suture pull‐out from the tendon. Based on our biomechanical findings, rotator cuff repair with the mesh suture might provide superior initial strength against failure compared with the traditional polydioxanone suture II or FiberWire sutures. Use of the mesh suture may provide increased initial fixation strength and decrease gap formation, which could result in improved healing and lower re‐tear rates following rotator cuff repair. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:987–992, 2018.

     

Experimental rotator cuff repair. A preliminary study.

BACKGROUND: The repair of chronic, massive rotator cuff tears is associated with a high rate of failure. Prospective studies comparing different repair techniques are difficult to design and carry out because of the many factors that influence structural and clinical outcomes. The objective of this study was to develop a suitable animal model for evaluation of the efficacy of different repair techniques for massive rotator cuff tears and to use this model to compare a new repair technique, tested in vitro, with the conventional technique. METHODS: We compared two techniques of rotator cuff repair in vivo using the left shoulders of forty-seven sheep. With the conventional technique, simple stitches were used and both suture ends were passed transosseously and tied over the greater tuberosity of the humerus. With the other technique, the modified Mason-Allen stitch was used and both suture ends were passed transosseously and tied over a cortical-bone-augmentation device. This device consisted of a poly(L/D-lactide) plate that was fifteen millimeters long, ten millimeters wide, and two millimeters thick. Number-3 braided polyester suture material was used in all of the experiments. RESULTS: In pilot studies (without prevention of full weight-bearing), most repairs failed regardless of the technique that was used. The simple stitch always failed by the suture pulling through the tendon or the bone; the suture material did not break or tear. The modified Mason-Allen stitch failed in only two of seventeen shoulders. In ten shoulders, the suture material failed even though the stitches were intact. Thus, we concluded that the modified Mason-Allen stitch is a more secure method of achieving suture purchase in the tendon. In eight of sixteen shoulders, the nonaugmented double transosseous bone-fixation technique failed by the suture pulling through the bone. The cortical-bone-augmentation technique never failed. In definite studies, prevention of full weight-bearing was achieved by fixation of a ten-centimeter-diameter ball under the hoof of the sheep. This led to healing in eight of ten shoulders repaired with the modified Mason-Allen stitch and cortical-bone augmentation. On histological analysis, both the simple-stitch and the modified Mason-Allen technique caused similar degrees of transient localized tissue damage. Mechanical pullout tests of repairs with the new technique showed a failure strength that was approximately 30 percent of that of an intact infraspinatus tendon at six weeks, 52 percent of that of an intact tendon at three months, and 81 percent of that of an intact tendon at six months. CONCLUSIONS: The repair technique with a modified Mason-Allen stitch with number-3 braided polyester suture material and cortical-bone augmentation was superior to the conventional repair technique. Use of the modified Mason-Allen stitch and the cortical-bone-augmentation device transferred the weakest point of the repair to the suture material rather than to the bone or the tendon. Failure to protect the rotator cuff post-operatively was associated with an exceedingly high rate of failure, even if optimum repair technique was used. CLINICAL RELEVANCE: Different techniques for rotator cuff repair substantially influence the rate of failure. A modified Mason-Allen stitch does not cause tendon necrosis, and use of this stitch with cortical-bone augmentation yields a repair that is biologically well tolerated and stronger in vivo than a repair with the conventional technique. Unprotected repairs, however, have an exceedingly high rate of failure even if optimum repair technique is used. Postoperative protection from tension overload, such as with an abduction splint, may be necessary for successful healing of massive rotator cuff tears.     

Association of osteopenia of the humeral head with full-thickness rotator cuff tears

Rotator cuff tendon repair may fail for various reasons. Although the role of repair techniques and of the musculotendinous unit has been studied, there is little information on the quality of the bone to which the tendon is to be repaired. Therefore, 14 cadaveric humeral heads, 7 specimens without and 7 with a full-thickness rotator cuff tendon tear, were quantitatively assessed by use of high-resolution micro-computed tomography. Bone density is higher below the articular surface than in the greater tuberosity (40% vs 10%-20%), and tendon tears are associated with a reduction in cancellous bone density of greater than 50%, leading to a virtually hollow greater tuberosity, with intact cortical bone. The results found suggest that in long-standing rotator cuff tears, creating a deep trough should be avoided to achieve reliable tendon-to-bone contact. For optimal suture fixation to bone, sutures or anchors should be positioned subcortically or medially under the articular surface.     

Part I: Footprint contact characteristics for a transosseous-equivalent rotator cuff repair technique compared with a double-row repair technique

Rotator cuff repair via transosseous tunnels can improve footprint contact area and pressure when compared with suture anchor techniques. A double-row technique has been used clinically to improve footprint coverage by a repaired tendon. We hypothesized that a transosseous-equivalent rotator cuff repair via tendon suture bridges would demonstrate improved pressurized contact between the tendon and tuberosity when compared with a double-row technique. In 6 fresh-frozen human shoulders, a transosseous-equivalent rotator cuff repair was performed: a suture limb from each of 2 medial anchors was bridged over the tendon and fixed laterally with an interference screw (4 suture bridges). In 6 of the contralateral specimens, two types of repair were performed randomly in each specimen: (1) a double-row repair and (2) a transosseous-equivalent repair with a single screw (2 suture bridges). For all repairs, pressure-sensitive film was placed at the tendon-footprint interface, and software was used to obtain measurements. The mean pressurized contact area between the tendon and insertion was significantly greater for the 4-suture bridge technique (124.2 +/- 16.3 mm2, 77.6% footprint) compared with both the double-row (63.3 +/- 28.5 mm2, 39.6% footprint) and 2-suture bridge (99.7 +/- 22.0 mm2, 62.3% footprint) techniques (P < .05). The mean interface pressure exerted over the footprint by the tendon was greater for the 4-suture bridge technique (0.27 +/- 0.04 MPa) than for the double-row technique (0.19 +/- 0.01 MPa) (P = .002). The transosseous-equivalent rotator cuff repair technique can improve pressurized contact area and mean pressure between the tendon and footprint when compared with a double-row technique. A transosseous-equivalent technique, using suture bridges, may help optimize the healing biology at a repaired rotator cuff insertion.     

Mechanical strength of arthroscopic rotator cuff repair techniques: an in vitro study

BACKGROUND: Retears after rotator cuff repairs occur relatively frequently and may compromise the functional result. The goal of this study was to analyze the mechanical properties following arthroscopic techniques for rotator cuff repair and to evaluate possible alternative techniques. METHODS: In the first part, five different bone anchors (the Revo screw; Mitek Rotator Cuff anchor, 5.0-mm Statak, PANALOK RC absorbable anchor, and 5.0-mm Bio-Statak) were tested in vitro under cyclic loading on five pairs of cadaveric shoulders. Then five types of arthroscopic tendon suturing instruments were tested on rotator cuff tendons. Finally, the arthroscopically performed mattress and modified Mason-Allen stitches, fixed with either the Revo screw or the Bio-Statak, were evaluated on ten pairs of human cadaveric shoulders. RESULTS: The holding strengths of the various anchors were similar, ranging from 130 to 180 N, and approximated the holding strength of knotted number-2 suture materials. The fixation of the tested anchors yielded comparable values of stiffness except for one anchor, which showed significantly greater subsidence under cyclic load (p = 0.003). All tested, commercially available arthroscopic suturing devices were unsuitable for performing a modified Mason-Allen stitch on normal supraspinatus tendons. Modification of a commercially available suture punch with a longer needle allowed us to consistently perform a modified Mason-Allen stitch. The modified Mason-Allen stitch, which has shown favorable mechanical properties in open repairs of the rotator cuff, was not found to be stronger than the mattress stitch when performed arthroscopically and used with bone anchors. When the modified Mason-Allen stitch was fixed to one anchor, it was even weaker than a mattress stitch repaired with another anchor (168 versus 228 N). Unequal loading of the two suture branches due to the more rigid modified Mason-Allen stitch may be the reason for this difference. CONCLUSIONS: Arthroscopic techniques for rotator cuff repair with use of the mattress stitch and bone anchors allow for a relatively solid fixation. The holding strength is not improved with use of the modified Mason-Allen stitch. Although a direct comparison with previous in vitro studies is not possible, the holding strength of open fixation techniques seems to be stronger. If rotator cuffs are subjected to high postoperative loading, open repair might be preferred to reduce the risk of a retear, until stronger arthroscopic fixation techniques are developed.     

Tension-free cuff repairs with excision of macroscopic tendon lesions and muscular advancement: results in a prospective series with limited fatty muscular degeneration

Recurrent tears after rotator cuff repairs are frequent. These could be influenced by excessive tension on a degenerated tendinous stump and by fatty degeneration of the cuff muscles. The goal of this study was to evaluate the anatomic and functional results of tension-free cuff repairs with the excision of macroscopic tendon lesions in a series with limited muscular fatty degeneration of the infraspinatus and a global fatty degeneration index of rotator cuff muscles equal to or lower than 2. We studied 27 tears, comprising 13 cases involving both supraspinatus and infraspinatus tears, 13 cases with 3-tendon tears, and 1 case with only a supraspinatus tear. All shoulders were operated on through a transacromial approach easily repaired with 2 titanium screws with washers. To obtain a repair without tension, a single advancement was performed in 20 cases and a double advancement of both the supraspinatus and infraspinatus was done in 7 cases. The shoulders were evaluated clinically preoperatively and postoperatively with the non-weighted Constant score and anatomically with computed arthrotomography scans. The mean age at operation was 59.5 years, and the length of follow-up ranged from 1 to 4 years. Of the cuffs, 23 (85%) were watertight 1 year after surgery. No predictive factor of retear could be found. The functional improvement was statistically significant only for watertight cuffs, with an improvement of the Constant score from 57.8 to 75. The only predictive factor of functional outcome in this watertight group was the preoperative Constant score. Single and double advancements yielded similar functional results regardless of the extent of the initial tear, provided that the cuff was watertight at revision.     

Mattress suture-bridge technique for bursal-side partial-thickness rotator cuff tears

The standard procedure used to repair partial-thickness tears involves initial progression of the lesion to a full-thickness tear prior to tendon repair. However, the option for a bursal-side partial-thickness rotator cuff tear includes the preservation of as much of the remaining intact fibers as possible. Instead of inserting suture anchors in the medial row, as in the conventional suture-bridge technique, two mattress sutures are inserted into the rotator cuff. Full-thickness access is achieved using a percutaneous spinal needle and medial mattress sutures to preserve the articular bone attachment of the remnant fibers and to compress the repaired tendon on the footprint. Our method can help preserve the remnant rotator cuff tendon without tissue damage and can restore the normal rotator cuff footprint.     

Passive tension and gap formation of rotator cuff repairs

The objectives of this study were to quantify the relationship between passive tension of rotator cuff repairs and arm position and to examine the effect of this tension on repair gap formation. Five patients undergoing open surgical rotator cuff repair of the supraspinatus tendon were recruited. Tendon tension was recorded as the supraspinatus was advanced into a bone trough and secured. The relationship between arm position and repair tension was then measured. Standardized rotator cuff tears were created in 3 cadaveric shoulders and repaired by use of the intraoperative technique. The difference in tension measured between 0 degrees and 30 degrees abduction was statically applied for 24 hours and the gap formation measured. Repair tension increased with advancement of the supraspinatus tendon into the bone trough. Abduction reduced the repair load. The mean reduction in load by 30 degrees abduction was 34 N. Twenty-four hours of 34-N loading caused gap formation of 9 mm in cadaveric rotator cuff repairs. Passive tension in surgically repaired rotator cuffs may contribute to repair failure and can be modified by arm positioning.     

Tissue fixation security in transosseous rotator cuff repairs: A mechanical comparison of simple versus mattress sutures

The primary purpose of this investigation was to compare tissue fixation security by simple sutures versus mattress sutures in transosseous rotator cuff repair. These two repair techniques were each performed in 17 human cadaver shoulders, with two bone tunnels being used for the repair by two simple sutures and two other bone tunnels being used for the repair by one mattress suture. The repairs were loaded to failure in a servohydraulic materials test system. Rotator cuff repair by simple sutures was found to be significantly stronger than repair by mattress sutures (P = .0007). The average ultimate load to failure for the simple suture construct (189.62 N) was 39.72% greater than that for the mattress suture construct (135.71 N). Most of the failures occurred by suture breakage at the knot. Load-sharing by multiple suture tails and multiple knots in the simple suture configuration likely contributed to its superior strength characteristics compared with the mattress suture configuration.     

In situ transtendon repair outperforms tear completion and repair for partial articular-sided supraspinatus tendon tears

This biomechanical study compared 2 repair techniques for high-grade, partial, articular-sided supraspinatus tendon tears of the rotator cuff: transtendon in situ repair and tear completion with repair. Standardized, 50% partial, articular-sided supraspinatus lesions were created in 10 pairs of matched fresh, frozen cadaveric shoulders: 10 underwent partial lesion repair with an in situ transtendon technique using 2 suture anchors. In the contralateral 10 shoulders, the partial lesion was converted to a full-thickness tear and repaired with a double-row technique, using 4 suture anchors. Cyclic loading to failure of the supraspinatus tendon was performed using a material testing machine. Gap formation was measured for each rotational position and each incremental load. The in situ transtendon repair had statistically significant less gapping (P = .0001) and higher mean ultimate failure strength (P = .0011) than the double-row repair. In situ transtendon repair was biomechanically superior to tear completion for partial, articular-sided supraspinatus tears.     

Biomechanical comparison of suture anchor versus margin convergence plus suture anchor for rotator cuff repair

Objective: To evaluate results of margin convergence versus suture anchors in rotator cuff repair, and to determine which method is mechanically superior. Methods: Eighteen kangaroo shoulders were randomly divided into three groups (n = 6). A full thickness tendon defect 1.0 cm × 1.5 cm in size was created in the supraspinatus tendon at humeral insertion, simulating a massive rotator cuff tear. Three different techniques were employed for rotator cuff repair: (i) Mitek GII suture anchor alone (Group 1); (ii) margin convergence alone (Group 2); and (iii) margin convergence plus Mitek GII suture anchor (Group 3). Combined loads were applied to each specimen. After completion of cyclic loading, the construct was loaded to failure. ANOVA and LSD (Least Significant Difference) multiple comparisons of the means were applied to results. Results: Cyclic load testing showed progressive gap formation in each repaired specimen with increasing cycles. Group 1 reached 50% failure at an average of 34 cycles, Group 2 at 75 cycles and Group 3 at 73 cycles. There were significant difference between Groups 1 and 2, and Groups 1 and 3 (P ≤ 0.001). After 100 loading cycles, the average gap size was 6.8 mm, 6.1 mm and 4.7 mm in Groups 1, 2 and 3, respectively. There was a significant difference between Groups 1 and 3 (P ≤ 0.015). All specimens eventually reached failure. Conclusion: Rotator cuff repairs with margin convergence +/? suture anchor were far stronger than suture anchor alone, both in gap formation and ultimate failure load. However, progressive gap formation with cyclic loading seems inevitable after cuff repair, which may facilitate clinical understanding of the phenomena of re‐tear or residual defect.     

Accuracy of ultrasound imaging of the rotator cuff in shoulders that are painful postoperatively

BACKGROUND: Evaluation of the rotator cuff in a shoulder that has been persistently painful postoperatively could be challenging. Magnetic resonance imaging has been the preferred imaging method, but accuracy rates have been lower for those shoulders than for shoulders that have not been operated on; also, magnetic resonance imaging is susceptible to suture anchor artifact. The purpose of this study was to evaluate the diagnostic accuracy of ultrasound for evaluating the rotator cuff in shoulders that are painful postoperatively. METHODS: The records of forty-four consecutive patients who had undergone both a high-resolution ultrasound examination and subsequent shoulder arthroscopy were retrospectively reviewed. Thirty-four patients underwent rotator cuff repair at the time of the arthroscopy, and ten had subacromial decompression or another procedure without cuff repair. The results of the ultrasound examination were compared with the intraoperative findings of the arthroscopic examination (the "gold standard"). RESULTS: Ultrasound led to a correct diagnosis for forty of the forty-four patients. Twenty-two recurrent rotator cuff tears and twenty-two intact rotator cuffs were found at surgery. Ultrasound correctly identified twenty of the twenty-two rotator cuff tears (true-positive results) and twenty of the twenty-two intact rotator cuffs (true-negative results). Two intact cuffs were identified as having a full-thickness tear (false-positive results), and two cuffs with a full-thickness rotator cuff tear were identified as being intact (false-negative results). The sensitivity and specificity of ultrasound for identifying rotator cuff integrity postoperatively were 91% and 86%, respectively. The accuracy was 89%. CONCLUSIONS: Ultrasound is a highly accurate imaging study for evaluating the integrity of the rotator cuff in shoulders that have undergone an operation. Its accuracy for operatively treated shoulders appears to be comparable with that previously reported for shoulders that had not been operated on.     

Long-term outcome and structural integrity following open repair of massive rotator cuff tears

Background:

Surgical repair of massive rotator cuff tears is associated with less favorable clinical results and a higher retear rate than repair of smaller tears, which is attributed to irreversible degenerative changes of the musculotendinous unit.

Materials and Methods:

During the study period, 25 consecutive patients with a massive rotator cuff tear were enrolled in the study and the tears were repaired with an open suture anchor repair technique. Preoperative and postoperative clinical assessments were performed with the Constant score, the simple shoulder test (SST) and a pain visual analog scale (VAS). At the final follow-up, rotator cuff strength measurement was evaluated and assessment of tendon integrity, fatty degeneration and muscle atrophy was done using a standardized magnetic resonance imaging protocol.

Results:

The mean follow-up period was 70 months. The mean constant score improved significantly from 42.3 to 73.1 points at the final follow-up. Both the SST and the pain VAS improved significantly from 5.3 to 10.2 points and from 6.3 to 2.1, respectively. The overall retear rate was 44% after 6 years. Patients with an intact repair had better shoulder scores and rotator cuff strength than those with a failed repair, and also the retear group showed a significant clinical improvement (each P<0.05). Rotator cuff strength in all testing positions was significantly reduced for the operated compared to the contralateral shoulder. Muscle atrophy and fatty infiltration of the rotator cuff muscles did not recover in intact repairs, whereas both parameters progressed in retorn cuffs.

Conclusions:

Open repair of massive rotator tears achieved high patient satisfaction and a good clinical outcome at the long-term follow-up despite a high retear rate. Also, shoulders with retorn cuffs were significantly improved by the procedure. Muscle atrophy and fatty muscle degeneration could not be reversed after repair and rotator cuff strength still did not equal that of the contralateral shoulder after 6 years.

Level of evidence:

Level IV     

The new subclavian portal and modified neviaser portal for arthroscopic rotator cuff repair

Shoulder arthroscopy and the introduction of suture anchors has provided the surgeon with the ability to repair rotator cuff tears through minimal incisions. Rotator cuff repair involves the use of several portals, such as the posterior portal, the anterior portal, the anterior superior portal, the anterior inferior portal, and the Neviaser portal. The authors have developed 2 additional portals, the new Subclavian portal and the modified Neviaser portal, to improve the safety and efficacy of rotator cuff repair and solve a number of problems associated with traditional repair techniques. The subclavian portal is located directly below the clavicle, 1 to 2 cm from the acromioclavicular joint, and instruments are aimed medial to lateral. The modified Neviaser portal changes the angle of insertion of the Neviaser portal. Instruments are aimed 20° from the horizontal plane and 45° anterior, directly at the suture anchor. Repair techniques using each portal were reviewed. Twenty cadaveric shoulders were dissected for each portal and the anatomy from each portal was documented. The cadaveric dissections showed that this portal passes greater than 6 cm from the brachial plexus, musculocutaneous nerve, and subclavian artery and vein, and 4.7 cm from the cephalic vein. The modified Neviaser portal was shown to be safer than the Neviaser portal because it passes on top of the supraspinatous muscle, thereby protecting the suprascapular nerve. These portals provide an optimal angle of approach to the rotator cuff tendon and suture anchor as well as improved safety and efficacy in the repair of rotator cuff tears.     

Disintegration of an absorbable rotator cuff anchor six weeks after implantation

Rotator cuff failure by suture-bone or suture anchor pull-out, suture breakage, knot slippage, and tendon pull-out are well described. I report a case of early disintegration of a bioabsorbable suture anchor. A 77-year-old woman underwent arthroscopic rotator cuff repair. On suspecting failure, the repair was repeated 40 days later. Arthroscopy revealed disintegration of the suture loop from the anchor. Open rotator cuff repair was then performed with transosseous suture and metallic anchors.     

Cyclic loading of anchor-based rotator cuff repairs: Confirmation of the tension overload phenomenon and comparison of suture anchor fixation with transosseous fixation

Previous experimental studies of failure of rotator cuff repair have involved single pull to ultimate load. Such an experimental design does not represent the cyclic loading conditions experienced in vivo. We created 1 ×2 cm rotator cuff defects in 16 cadaver shoulders, repaired each defect with three MitekRC suture anchors (Mitek Surgical Products, Inc, Westwood, MA) using simple sutures of No. 2 Ethibond, and cyclically loaded the repairs by a servohydraulic materials test system actuator at physiological rates and loads (rate of 33 mm/s, load 180 N). A progressive gap was noted in each specimen, for a 100% rate of failure of the repairs. The central suture always failed first and by the largest magnitude, confirming tension overload centrally. One specimen exhibited combined bone and tendon failure, but the other 15 specimens failed through the tendon. Overall, the repairs failed to 5 mm and 10 mm at an average of 61 cycles and 285 cycles, respectively. Half the specimens were less than 45 years of age and had a 5-mm and 10-mm failure at an average of 107 and 478 cycles, respectively. The other half were over 45 years of age and failed to 5 mm and 10 mm at an average of 17 and 91 cycles, respectively, indicating more rapid failure of the rotator cuff tendons in the older group, and this was statistically significant (P ≤ .02). Comparison of suture anchor fixation in this study with transosseous bone tunnel fixation in a previous cyclic loading study at this institution indicates that bone fixation by suture anchors is significantly less prone to failure than bone fixation through bone tunnels (P = .0008). Changing the bone fixation from bone tunnels to suture anchors effectively transferred the weak link from bone to tendon.     

Editorial Commentary: Dermal Allografts Are Indicated for Repair of Irreparable Rotator Cuff Tears and for Revision Surgery,and May Be Cost-Effective for Primary Repair

Improving rotator cuff repair results is the goal of all shoulder surgeons. The addition of a biologic graft may speed healing, allow accelerated rehabilitation, and increase healing rates. Recent research suggests that augmentation of rotator cuff repair using dermal allograft may be cost-effective. Indications for dermal allografts are revision rotator cuff repairs and primary cuff repairs in which a tensionless repair cannot be accomplished. Allografts act as a load-sharing device to allow tendons to heal without tension. They also serve to fill the gap in irreparable cuff tears. It is important to understand that augmentation will not compensate for advanced muscle fatty atrophy or neurapraxia. Precautions to prevent Cutibacterium acne nosocomial infection are essential. The healing time or dermal grafts is considerably longer than the repaired native cuff tendon, requiring supervised rehabilitation. Dermal allografts are a crucial tool for repair of irreparable rotator cuff tears and for revision surgery. From an economic standpoint, they now also may be considered for use in primary rotator cuff repair surgery.