Biomechanical evaluation of transosseous rotator cuff repair: do anchors really matter?

Arthroscopic Modified Double-Pulley Suture-Bridge Repair of Medium-Sized Supraspinatus Tendon Tears

At present, the repair patterns for medium-sized supraspinatus tendon tears are double- and single-row repairs. However, the limitations of double-row repair include excessive anchor implantation and incremental surgical cost and time, whereas a deficient tendon-bone contact area exists with single-row repair. The modified double-pulley suture-bridge repair presented in this study is an arthroscopic technique using 3 double-loaded suture anchors combined with a double-pulley technique to form a hybrid repair pattern with a double row as the mainstay and a single row as the supplement. In the treatment of medium-sized tendon tears, the modified double-pulley suture-bridge repair can not only maximize the tendon-bone contact area but also lower the surgical cost and shorten the operative time. The surgical technique is described, including pearls and pitfalls, as well as advantages and disadvantages.

Arthroscopic Repair of Posterosuperior Rotator Cuff Tears Using a Modified Mason-Allen Suture Technique With a Transosseous-Equivalent Construct: A Technical Note

Iterative evolutions in arthroscopic rotator cuff repair aim to improve its biomechanical and biological properties. This technical note describes an arthroscopic rotator cuff repair technique that combines the advantages of a modified Mason-Allen suture technique with the advantages of an arthroscopic transosseous-equivalent construct. Two alternatives for creating this construct are described. The Mason-Allen stitch is easy to perform, is cost-effective, and increases tissue security without tendon strangulation. The arthroscopic transosseous-equivalent construct increases footprint contact pressure and coverage, aiding healing of the repaired rotator cuff.

Comparison of cost, surgical time, and clinical results between arthroscopic transosseous rotator cuff repair with lateral cortical augmentation and arthroscopic transosseous equivalent suture bridge: A propensity score-matched analysis

BACKGROUND

To reduce the healthcare burden, the clinical results of arthroscopic rotator cuff repair and the cost of the implants used have recently been focused upon. This study compared implant cost, surgical time, short-term clinical results, and cuff repair integrity 2 years postoperatively between arthroscopic transosseous rotator cuff repair using lateral cortical augmentation (TOA) and arthroscopic transosseous-equivalent suture bridge (TOE).

METHODS

This study included 220 patients with rotator cuff repairs performed by a single surgeon between December 2013 and December 2018. Overall, 70 TOA and 68 TOE cases met the inclusion criteria. The same surgeon performed the procedures at two different hospitals, and the techniques differed between the facilities. A total of 42 TOA patients were matched with 42 TOE patients. The patients were matched using a propensity score analysis by gender, age, and cuff tear size. The minimum follow-up period was 2 years. Implant cost and surgical time were compared between the two methods. The range of motion, clinical outcomes, and visual analog scale were evaluated. Magnetic resonance imaging was performed to examine cuff repair integrity 2 years postoperatively.

RESULTS

The follow-up rate was 81% (112/138 patients). Implant cost was significantly lower with TOA ($1,396 vs. $2,165; p < 0.001) than with TOE. The average surgical time in the TOA method was significantly shorter than that in the TOE method (82 vs. 109 min; p = 0.001). At a minimum 2-year follow-up, the mean active elevation, abduction, and clinical outcomes improved with both methods, although no improvements in external and internal rotations were observed with either method. There were no significant differences in the postoperative variables and retear rate (TOA, 12%; TOE, 19%; p = 0.548) between the two methods.

CONCLUSIONS

TOA and TOE achieved comparable clinical results; however, TOA was more cost-effective and had a shorter surgical time than TOE.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective matched control study.

Editorial Commentary: Quadriceps Tendon Suture Anchor Repair Provides Better Patient-Reported Outcomes Than Transosseous Tunnel Repair: Defining the New Gold Standard

Quadriceps tendon suture anchor repair provides biomechanically greater and more consistent failure loads than transosseous tunnel repair, including less cyclic displacement (gap formation). Although satisfactory clinical outcomes are found with both repair techniques, few studies provide a side-to-side comparison. However, recent research demonstrates better clinical outcomes in using suture anchors, with equal failure rates. Suture anchor repair is minimally invasive requiring smaller incisions, less patellar dissection, and eliminates patellar tunnel drilling that can breach the anterior cortex, create stress risers, result in osteolysis from nonabsorbable intraosseous sutures and longitudinal patellar fractures. Suture anchor quadriceps tendon repair should now be considered the gold standard.

Comparison of suture-bridge and independent double-row techniques for medium to massive posterosuperior cuff tears: a two-year retrospective study

BACKGROUND

Transosseous-equivalent suture-bridge (TOE-SB) and independent double-row (IDR) repair techniques were developed to treat rotator cuff tears. The study was designed to prove that both TOE-SB and IDR techniques provided comparable clinical results and retear rate for medium to massive posterosuperior rotator cuff tears, while the surgical time and number of suture anchor used were less in the IDR group.

STUDY DESIGN

Level of evidence: level III, Retrospective comparative study.

METHODS

Patients with medium to massive posterosuperior rotator cuff tears receiving arthroscopic TOE-SB and IDR between November 2016 to October 2019 were retrospectively enrolled. All patients were confirmed to have grade ≤ 2 fatty infiltration in the muscles of the torn tendons. Revision, concomitant subscapularis tear, acromiohumeral distance < 7 mm, glenohumeral osteoarthritis, partial repair, incomplete repair, partial thickness, or irreparable posterosuperior cuff tear were excluded. Surgical time, number of suture anchor used for the surgery, pre-operative, and post-operative clinical scores such as Constant-Murley score, subjective shoulder value (SSV), and visual analog scale (VAS) were compared. The retear rates between groups were evaluated by ultrasound.

RESULTS

Thirty-five IDR and thirty-five TOE-SB repairs were enrolled. The IDR technique required much fewer anchors than TOE-SB did to complete the cuff repair. The mean operation time in IDR and TOE-SB group were 86(18.23), and 114(18.7) (min), respectively (P <  0.01). The mean number of anchors used to complete the cuff repair was 2(0.17) in IDR and 3(0.61) in TOE-SB (P <  0.01). The Constant-Murley score improved from 34.9 ± 6.6 to 80.6 ± 9.4 in the IDR group, and 37.4 ± 6 to 81.9 ± 4.6 in the TOE-SB group (both P <  0.001). SSV improved from 24.6 ± 9.6 to 79.3 ± 10.6 in the IDR, and 27.9 ± 9 to 82.9 ± 6.9 in the TOE-SB group (both P <  0.001). VAS improved from 7.9 ± 0.6 to 1.5 ± 0.7 in the IDR, and 8 ± 0.5 to 1.3 ± 0.6 in the TOE-SB group (both P <  0.001) at final follow-up. No significant difference was found between the retear rates (14.3% in the IDR vs. 17.1% in the TOE-SB, respectively) in the 2-year follow-up.

CONCLUSIONS

Both IDR and TOE-SB group provided comparable clinical results and retear rates for medium to massive posterosuperior rotator cuff tears. The surgical time and number of anchors used were less in the IDR group than in the TOE-SB group.

The Effect of PRP Augmentation of Arthroscopic Repairs of Shoulder Rotator Cuff Tears on Postoperative Clinical Scores and Retear Rates: A Systematic Review and Meta-Analysis

The aim of this review and meta-analysis is to assess recent clinical trials concerning the combination of operative treatment of rotator cuff tears and the administration of PRP and its effect on clinical scores and postoperative retear rates. The trials were used to compare the combination of PRP treatment and arthroscopic rotator cuff repair to arthroscopy alone. Twenty-five clinical trials were reviewed. A risk-of-bias assessment was made for all randomized clinical trials included, using the Cochrane collaboration’s tool as well as a quality assessment for all non-randomized studies utilizing the Newcastle−Ottawa scale. The PRP-treated patients showed statistically significant improvement postoperatively compared to control groups concerning the Constant−Murley (mean difference 2.46, 95% CI 1.4−3.52, p < 0.00001), SST (mean difference 0.32, 95% CI 0.02−0.63, p = 0.04), and UCLA (mean difference 0.82, 95% CI 0.23−1.43, p = 0.07) scores. A statistically significant decrease of retear rates in the PRP-treated patients, with a risk ratio of 0.78 (95% CI 0.65−0.94, p = 0.01), was found. We believe that the results presented have positive aspects, especially concerning the retear risk, but are yet inconclusive concerning clinical results such as shoulder pain and function.

Arthroscopic Anchorless Transosseous Rotator Cuff Repair Produces Equivalent Clinical Outcomes and Imaging Results as a Standard Suture Bridge Technique with Anchors

Purpose

To compare the clinical and imaging outcome of arthroscopic transosseous (TO)-equivalent rotator cuff repair (RCR) with anchors with arthroscopic anchorless TO RCR at a minimum of 2 years postoperatively.

Methods

The study population included patients who underwent RCR using either an anchorless TO technique with a TO suture passing device (group A) and those who were matched for tear size and underwent RCR using suture anchors for repair (group B). The inclusion criterion was an easily reducible rotator cuff tear with a sagittal extension of 2 to 4 cm. After a minimum of 2 years, clinical outcome scores and magnetic resonance imaging were obtained. Tendon quality and footprint integration were evaluated using the Sugaya classification.

Results

Seventy patients were included. A total of 45 were in group A and 25 were in group B. Group A had 2 bone tunnels and 4 sutures using an X-box configuration, and group B had a suture bridge construct of 4 anchors. Group A and B had identical anteroposterior tear size and were comparable for age. The Constant score improved from 50 ± 17.4 to 88 ± 8.6 in group A versus 48 ± 14.5 to 87 ± 7.2 in B. The Subjective Shoulder Value rose from 47 ± 19.1 to 95 ± 7.4 in group A vs from 47 ± 19.4 to 95 ± 7.6 in B. Neither the preoperative (P ≥ .502) nor postoperative scores (P ≥ .29) showed a significant difference. Magnetic resonance imaging showed 2 small retears in group A and one in B, resulting in an identical 4% retear rate. The mean Sugaya type was 2.02 versus 2.24 (P = .206) for groups A versus B.

Conclusions

Anchorless TO RCR is a valid alternative to suture anchor techniques. Clinical outcome data showed comparable results for both techniques after a follow-up of 2 years. The healing results as observed on magnetic resonance imaging were also equivalent for both groups.

Level of Evidence

Level III, retrospective comparative study.

Comparison of Occurrence of Bone Tunnel Laceration, Clinical Results, and Cuff Repair Integrity of Transosseous Arthroscopic Rotator Cuff Repair With and Without Lateral Cortical Augmentation

Purpose

To compare the occurrence of bone tunnel laceration, the short-term clinical results, and cuff repair integrity of transosseous arthroscopic rotator cuff repair (ARCR) using a tunneling device, with and without lateral cortical augmentation.

Methods

A retrospective review of patients who underwent transosseous ARCR from May 2012 to December 2017 was conducted. The inclusion criterion was repairable medium- to massive-sized full-thickness rotator cuff tear. This study included 2 consecutive series of patients undergoing transosseous ARCR with and without lateral cortical augmentation, called the ITO method and AT method, respectively. The incidence of bone tunnel laceration was evaluated intraoperatively. Patients were assessed through a range of motion and Constant scores preoperatively and at final follow-up. Further, magnetic resonance imaging was performed at 24 months postoperatively to examine the repaired rotator cuff integrity.

Results

A total of 121 subjects were included: 33 in the AT group and 88 in the ITO group. The intraoperative bone tunnel laceration occurrence rate was 67% and 4% for the AT and ITO methods, respectively; the difference was significant (P = .001). Anatomic failure rate (Sugaya Ⅲ, Ⅳ, and Ⅴ) rate for medium- to large-sized tears was significantly lower for the ITO than for the AT method (29% vs 65%, P = .004), but not for massive tears (61% vs 69%, P = .515). The mean forward elevation, abduction, external rotation, internal rotation, and Constant score were significantly improved at final follow-up from preoperative values. There were no significant differences between the 2 methods.

Conclusions

Transosseous ARCR using a tunneling device with and without lateral cortical augmentation is a reliable method of improving clinical results at a minimum follow-up of 2 years. The intraoperative occurrence rate of bone tunnel laceration occurrence rate and the anatomic failure rate of medium- to large-sized cuff tear were lower with lateral cortical augmentation than without it.

Level of Evidence

Level Ⅳ, therapeutic cases series.

Biomechanical Properties of Double-Row Transosseous Rotator Cuff Repair Combined With the Cinch Stitch in the Lateral Row

Background:

The self-cinching stitch has been verified to have high mechanical strength. The mechanical strength of combining transosseous rotator cuff repair (RCR) and the self-cinching stitch in the lateral row is unknown.

Purpose/Hypothesis:

The purpose of this study was to evaluate the biomechanical properties of transosseous RCR combined with the cinch stitch in the lateral row. We hypothesized that this construct would have better mechanical strength than would transosseous repair using a vertical cinch stitch or simple stitch.

Study Design:

Controlled laboratory study.

Methods:

Rotator cuff tears were simulated in 48 porcine shoulder specimens. The tears were repaired using 1 of 6 repair configurations: 2–simple stitch transosseous repair alone (group 2TO), with a vertical cinch stitch (group 2TO-VC), or with a horizontal cinch stitch (group 2TO-HC) or 4–simple stitch transosseous repair alone (group 4TO), with a vertical cinch stitch (group 4TO-VC), or with a horizontal cinch stitch (group 4TO-HC). All specimens were set at a 45° angle from the footprint and underwent cyclic loading from 10 to 160 N for 200 cycles, followed by a load-to-failure test at 10 mm/min.

Results:

During cyclic loading, all specimens in group 2TO and half of the specimens in group 2TO-VC failed by suture pullout. In the other groups, none of the specimens failed before 200 cycles. The yield load in group 2TO-HC was significantly greater than that in group 2TO-VC (261.43 vs 219.54 N, respectively; P < .05). There were significant differences between groups 4TO-HC and 4TO with regard to elongation (3.92 vs 5.68 mm, respectively), yield load (304.04 vs 246.94 N, respectively), and linear stiffness (63.44 vs 52.28 N/mm, respectively) (P < .01 for all). Group 4TO-HC also had shorter elongation and a superior yield load and linear stiffness compared with group 2TO-HC (P < .05 for all), and group 4TO-VC had shorter elongation and a stronger maximum load to failure and yield load than did group 2TO-VC (P < .05 for all).

Conclusion:

Increasing the number of medial simple stitches can prevent suture pullout. Adding the horizontal cinch stitch to the lateral row in transosseous repair can further improve biomechanical properties through a self-cinching mechanism.

Clinical Relevance:

Transosseous RCR with a horizontal cinch stitch in the lateral row may reduce the retear rate.

Load-to-failure characteristics of patellar tendon allograft superior capsule reconstruction compared with the native superior capsule

Background

The potential use of a patellar tendon allograft for superior capsular reconstruction has been demonstrated biomechanically; however, there are concerns regarding compromised fixation strength owing to the longitudinal orientation of the fibers in the patellar tendon. Therefore, the purpose of this study was to compare the fixation strength of superior capsule reconstruction using a patellar tendon allograft to the intact superior capsule.

Methods

The structural properties of the intact native superior capsule (NSC) followed by superior capsular reconstruction using a patellar tendon allograft (PT-SCR) were tested in eight cadaveric specimens. The scapula and humerus were potted and mounted onto an Instron testing machine in 20 degrees of glenohumeral abduction. Humeral rotation was set to achieve uniform loading across the reconstruction. Specimens were preloaded to 10 N followed by cyclic loading from 10 N to 50 N for 30 cycles, then load to failure at a rate of 60 mm/min. Video digitizing software was used to quantify the regional deformation characteristics.

Results

During cyclic loading, there was no difference found in stiffness between PT-SCR and NSC (cycle 1 - PT-SCR: 12.9 ± 3.6 N/mm vs. NSC: 22.5 ± 1.6 N/mm; P = .055 and cycle 30 - PT-SCR: 27.3 ± 1.4 N/mm vs. NSC: 25.4 ± 1.7 N/mm; P = .510). Displacement at the yield load was not significantly different between the two groups (PT-SCR: 7.0 ± 1.0 mm vs. NSC: 6.5 ± 0.3 mm; P = .636); however, at the ultimate load, there was a difference in displacement (PT-SCR: 20.7 ± 1.1 mm vs. NSC: 8.1 ± 0.5 mm; P < .001). There was a significant difference at both the yield load (PT-SCR: 71.4 ± 2.2 N vs. NSC: 331.6 ± 56.6 N; P = .004) and the ultimate load (PT-SCR: 217.1 ± 26.9 N vs. NSC: 397.7 ± 62.4 N; P = .019). At the yield load, there was a difference found in the energy absorbed (PT-SCR: 84.4 ± 8.9 N-mm vs. NSC: 722.6 ± 156.8 N-mm; P = .005), but no difference in energy absorbed was found at the ultimate load.

Conclusions

PT-SCR resulted in similar stiffness to NSC at lower loads, yield displacement, and energy absorbed to ultimate load. The ultimate load of the PT-SCR was approximately 54% of the NSC, which is comparable with the percent of the ultimate load in rotator cuff repair and the intact supraspinatus at time zero.

Current concepts in the evolution of arthroscopic rotator cuff repair

Arthroscopic rotator cuff repair has become one of the most common and successful surgeries performed in orthopedics. It represents the culmination of advances in many diverse fields such as optics, fluid dynamics, mechanical engineering, and most recently, orthobiologics. This article reviews the current state of the art of arthroscopic rotator cuff repair, through the lens of its historical context and evolution to our present understanding. We review the limitations in the current approach, and glance toward the future of rotator cuff regeneration with emerging technologies.

Supraspinatus tendon transosseous vs anchor repair surgery: a comparative study of mechanical recovery in the rabbit

BACKGROUND

Supraspinatus (SSP) tendon ruptures requiring surgical repair are common. Arthroscopic suture anchor fixation has gradually replaced transosseous repair in supraspinatus tendon tear. Our objective was to compare mechanical properties between transosseous and anchor supraspinatus repair in the first 6 postoperative weeks in a rabbit model.

METHODS

One hundred and fifty-two rabbits had one supraspinatus tendon repaired either with an anchor suture 1 week after detachment or with transosseous sutures. Rabbits were euthanized at 0, 1, 2, 4 or 6 postoperative weeks. Experimental and contralateral tendons (304 tendons) were mechanically tested to failure. Data are expressed as percent of contralateral.

RESULTS

Anchor repair had higher loads to failure compared to transosseous repair, at immediate repair (week 0, 52 ± 21% vs 25 ± 17%, respectively; p = 0.004) and at 1 postoperative week (64 ± 32% vs 28 ± 10%; p = 0.003) with no difference after 2 weeks. There was no difference in stiffness. Transosseous repairs showed higher rates of midsubstance failures compared to anchor repairs at 1 (p = 0.004) and 2 postoperative weeks (p < 0.001). Both transosseous and anchor repairs restored supraspinatus mechanical properties after 4 postoperative weeks.

CONCLUSION

Anchor repair provided better initial tensile strength while transosseous repair led to a faster normalization (namely, midsubstance) of the mode of failure. Research to optimize supraspinatus repair may need to consider the advantages from both surgical approaches.

The effect of autologous Achilles bursal tissue implants in tendon-to-bone healing of rotator cuff tears in rats

BACKGROUND

The aim of this study was to investigate the influence of autologous bursal tissue derived from the Achilles bursa on tendon-to-bone healing after rotator cuff tear repair in a rat model.

METHODS

A total of 136 Sprague-Dawley rats were randomly assigned to either an untreated or a bursal tissue application group or biomechanical testing and histologic testing after rotator cuff repair. After separating the supraspinatus tendon close to the greater tuberosity, the tendon was reattached either unaltered or with a bursal tissue interposition sewn onto the interface. Immunohistologic analysis was performed 1 and 7 weeks after supraspinatus tendon reinsertion. Biomechanical testing of the tendon occurred 6 and 7 weeks after reinsertion.

RESULTS

Immunohistologic results demonstrated a significantly higher percentage of Type II collagen (P = .04) after 1 and 7 weeks in the tendon-to-bone interface using autologous bursal tissue in comparison to control specimens. The bursa group showed a significantly higher collagen I to III quotient (P = .03) at 1 week after surgery in comparison to the 7-week postsurgery bursa groups and controls. Biomechanical assessment showed that overall tendon stiffness (P = .002) and the tendon viscoelasticity in the bursa group (P = .003) was significantly improved after 6 and 7 weeks. There was no significant difference (P = .55) in force to failure between the bursa group and the control group after 6 and 7 weeks.

CONCLUSION

Autologous bursal tissue derived from the Achilles bursa and implanted to the tendon-to-bone interface after rotator cuff repair facilitates a faster healing response to re-establish the biologic and biomechanical integrity of the rotator cuff in rats.

Clinical and functional outcomes of a novel transosseous device to treat rotator cuff tears: A minimum 2-year follow-up

PURPOSE

Despite the improvements in the repair equipment techniques of rotator cuff, a gold standard method has not been defined yet and transosseous fixation through deltoid-splitting (mini-open) approach is still regarded as a good option. The primary purpose of this study is to present satisfactory clinical and functional outcomes with a novel transosseous device in full-thickness rotator cuff tear through deltoid-splitting.

MATERIALS AND METHODS

This retrospective study was performed on 70 consecutive patients who underwent surgery by a single surgeon from June 2014 to June 2016 for a full-thickness rotator cuff tear and was managed with a novel transosseous device. Total number of patients, mean age, percentage of male and female patients, mean duration of follow-up, percentage of involvement of the dominant extremity, affected shoulder, and tear size were recorded. Functional and clinical outcomes were assessed baseline and postoperatively at 3 and 6 months and final follow-up using Disabilities of the Arm, Shoulder and Hand (Q-DASH) and Constant-Murley scores.

RESULTS

A total of 70 (49 (70%) female, 21 (30%) male) patients whose mean age was 58.66 ± 9.19 (38-77) years were included. The mean surgery time was 35.33 ± 5.34 (28-55) min. The mean follow-up time was 28.31 ± 3.03 (24-36) months. According to the DeOrio and Cofield classification, 15 (21.43%) tears were small, 33 (47.14%) medium, 16 (22.86%) large, and 6 (8.57%) massive. By the final follow-up, the mean Constant-Murley score had significantly improved from 27.67 ± 7.46 (13-41) to 81.25 ± 3.77 (74-87; p = 0.0001) and the Q-DASH score had decreased from 82.34 ± 10.37 (65.91-100) to 10.28 ± 6.88 (0-23.45; p = 0.0001). There were no significant differences in the Constant-Murley or Q-DASH score at baseline-final follow-up between the small, medium, large, and massive tear groups (p > 0.05).

CONCLUSIONS

Treatment of full-thickness rotator cuff tear using this novel transosseous device significantly improved functional and clinical scores. However, further long-term prospective randomized multicenter trials involving comparative studies are necessary to confirm these findings.

Anchorless Arthroscopic Transosseous and Anchored Arthroscopic Transosseous Equivalent Rotator Cuff Repair Show No Differences in Structural Integrity or Patient-reported Outcomes in a Matched Cohort

BACKGROUND

Anchored transosseous equivalent suture-bridge technique (TOE) is widely used for arthroscopic rotator cuff repair. It is unknown how patient outcomes scores, ROM, and integrity of the rotator cuff after repair using this anchored technique compare with those after repair using an anchorless transosseous technique (TO).

QUESTIONS/PURPOSES

(1) What are the differences in patient-reported outcomes (American Shoulder and Elbow Surgeons [ASES] score) and shoulder ROM between TO and TOE rotator cuff repair techniques at 1 and 2 years after surgery? (2) What is the difference in repair integrity as measured by the re-tear rate, assessed ultrasonographically at 1 year, between these two techniques? (3) What is the difference in procedure duration between the two techniques when performed by a surgeon familiar with each?

METHODS

We reviewed 331 arthroscopic rotator cuff repairs performed by one surgeon from December 2011 to July 2016 in this retrospective, matched-pair study. Of these patients, 63% (208 of 331) underwent repair with standard anchored technique (anchors placed in a double-row, TOE manner) and 37% (123 of 331) underwent anchorless TO repair, with the same indications for surgery between groups. Forty-four percent (91 of 208) of patients in the TOE group and 61% (75 of 123) of patients in the TO group met the inclusion criteria. Eighty percent (73 of 91) of patients in the TOE group and 88% (66 of 75) in the TO group had minimum 2-year follow-up. We matched each group to a cohort of 50 patients by sex, age, smoking status, and tear size (by Cofield classification: small, < 1 cm; medium, 1-3 cm; large, > 3-5 cm; or massive, > 5 cm). The resulting cohorts did not differ in mean age (TO, 62 years [range 53-65 years]; TOE, 58 years [range 53-65 years]; p = 0.79), mean BMI value (TO, 30 [range 27-33]; TOE, 29 [range 27-35]; p = 0.97), or dominant arm involvement (TO, 80%; TOE, 78%; p = 0.81). The cohorts were followed for at least 2 years (median, 3.2 years [interquartile range (IQR) 2.2-4.3] for TO and 2.9 years [IQR 2.0-3.5 years] for TOE). ASES scores and ROM were evaluated before surgery and at follow-up visits and were recorded in a longitudinally maintained institutional database. Repair integrity was assessed using ultrasonography at 1 year, as is standard in our practice. For each tear-size group, we calculated the proportion of intact tendon repairs versus the proportion of re-tears. Duration of surgery was recorded for each patient.

RESULTS

At 1 year, we observed no difference in median ASES scores (90 [IQR 92-98] for TO and 88 [IQR 72-98] for TOE; p = 0.44); external rotation (50° [IQR 45°-60°) for TO and 50° [IQR: 40°-60°] for TOE; p = 0.58); forward flexion (165° [IQR 160°-170°] for both groups; p = 0.91); or abduction (100° [IQR 90°-100°] for TO and 90° [IQR 90°-100°] for TOE; p = 0.06). Fourteen percent of shoulders (seven of 50) in each treatment group had evidence of re-tear at 1 year (p > 0.99): 0 of 2 small tears in each group, 0 of 7 medium tears in each group, five of 32 large tears in each group, and two of 9 massive tears in each group (all, p > 0.99). At 2 years, we found no differences in median ASES scores (92 [IQR 74-98)] for TO and 90 [IQR 80-100] for TOE; p = 0.84); external rotation (60° [IQR 50°-60°] for both groups; p = 0.74); forward flexion (170° [IQR 160°-170°] for both groups; p = 0.69); or abduction (100° [IQR 90°-100°] for both groups; p = 0.95). We found no differences between groups in mean ± SD procedure time, which was 103 ± 20 minutes for TO repair and 99 ± 20 minutes for TOE repair (p = 0.45).

CONCLUSIONS

TO and TOE techniques for arthroscopic rotator cuff repair results in no differences in ROM, ASES scores, re-tear rates, and surgical time. Randomized control trials are needed to confirm these similarities or determine a superior method of repair. Future cost analyses may also help to determine the relative value of each technique.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Comparison of the clinical and radiological outcomes of arthroscopic transosseous and transosseous-equivalent double-row rotator cuff repair techniques

OBJECTIVE

This study compared the clinical and radiological results of the arthroscopic transosseous (ATO) and transosseous-equivalent (TOE) double-row rotator cuff repair techniques.

METHODS

Prospective data collected from patients treated with ATO (32 women and 7 men, mean age: 57.03±6.39 years) and TOE (36 women and 8 men; mean age: 57.86±7.81 years) techniques were retrospectively evaluated. The visual analog scale score, Constant score, and Oxford shoulder score were used to assess the clinical results. Anchor pullout on standard anteroposterior shoulder radiographs and rotator cuff re-tear on magnetic resonance images were examined at the final follow-up to evaluate the radiological results. Rotator cuff re-tears were graded as per the classification system described by Sugaya et al. Results: The mean follow-up duration was 33.3±11.8 months. No difference was observed in the demographic data of the two groups. Significant improvement was observed in the postoperative shoulder scores of the groups; however, no difference was observed between the groups. Re-tear was detected in 10 patients of the TOE group and 9 patients of the ATO group. Age, tear size, and retraction level could cause re-tear.

CONCLUSION

In the treatment of rotator cuff tears, the ATO and TOE techniques may achieve considerable improvements in shoulder functions in the short term.

LEVEL OF EVIDENCE

Level III, Therapeutic study.

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.

Is Arthroscopic Transosseous Rotator Cuff Repair Strength Dependent on the Tunnel Angle?

Background

Previous studies have aimed to biomechanically improve the transosseous tunnel technique of rotator cuff repair. However, no previous work has addressed tunnel inclination at the time of surgery as an influence on the strength of the repair construct.

Hypothesis

We hypothesized that the tunnel angle and entry point would influence the biomechanical strength of the transosseous tunnel in rotator cuff repair. Additionally, we investigated how tunnel length and bone quality affect the strength of the repair construct.

Study Design

Controlled laboratory study.

Methods

Mechanical testing was performed on 10 cadaveric humeri. Variations in the bone tunnel angle were imposed in the supraspinatus footprint to create lateral tunnels with inclinations of 30°, 45°, and 90° relative to the longitudinal axis of the humeral shaft. A closed loop of suture was passed through the bone tunnel, and cyclic loading was applied until failure of the construct. Load to failure and distance between entry points were the dependent variables. Analysis of variance, post hoc paired t tests, and the Bonferroni correction were used to analyze the relationship between the tunnel angle and failure load. The Pearson correlation coefficient was then used to evaluate the correlation of the distance between entry points to the ultimate failure load, and t tests were used to compare failure loads between healthy and osteoporotic bone.

Results

Tunnels drilled perpendicularly to the longitudinal axis (90°) achieved the highest mean failure load (167.51 ± 48.35 N). However, there were no significant differences in the failure load among the 3 tested inclinations. Tunnels drilled perpendicularly to the longitudinal axis (90°) measured 13.86 ± 1.35 mm between entry points and were significantly longer (P = .03) than the tunnels drilled at 30° and 45°. We found no correlation of the distance between entry points and the ultimate failure load. Within the scope of this study, we could not identify a significant effect of bone quality on failure load.

Conclusion

The tunnel angle does not influence the strength of the bone-suture interface in the transosseous rotator cuff repair construct.

Clinical Relevance

The transosseous technique has gained popularity in recent years, given its arthroscopic use. These findings suggest that surgeons should not focus on the tunnel angle as they seek to maximize repair strength.

The Arthroscopic "Montgolfier Double-Row Knotless" Rotator Cuff Repair Technique

Contemporary arthroscopic double-row suture anchor rotator cuff repairs have superior biomechanics compared with prior iterations. Numerous techniques have been described, but consensus regarding value has yet to be established. We describe an effective and easily reproducible technique: the arthroscopic "Montgolfier double-row" repair technique. This knotless construct has an evenly distributed, load-sharing, radially oriented suture limb configuration much like the envelope cables of a Montgolfier hot-air balloon, its namesake. Other advantages include the ability to apply manual, progressive and calculated tension on each suture limb and easy intraoperative modification depending on tear size, shape, and delamination, as well as tissue tension and quality. Future studies are needed to validate the biomechanics and clinical outcomes of this technique.

Does Medial-Row Fixation Technique Affect the Retear Rate and Functional Outcomes After Double-Row Transosseous-Equivalent Rotator Cuff Repair?

Background:

Double-row transosseous-equivalent (TOE) rotator cuff repair techniques have been widely accepted because of their superior biomechanical properties when compared with arthroscopic single-row repair. Concerns regarding repair overtensioning with medial-row knot tying have led to increased interest in knotless repair techniques; however, there is a paucity of clinical data to guide the choice of technique.

Hypothesis:

Arthroscopic TOE repair techniques using knotless medial-row fixation will demonstrate lower retear rates and greater improvements in the Constant score relative to conventional knot-tying TOE techniques.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review of 3 databases (PubMed, Cochrane, and Embase) was performed using PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines. Inclusion criteria were English-language studies that examined repair integrity or Constant scores after arthroscopic rotator cuff repair with TOE techniques. Two investigators independently screened results for relevant articles. Data regarding the study design, surgical technique, retear rate, and Constant shoulder score were extracted from eligible studies. A quality assessment of all articles was performed using the Methodological Index for Non-Randomized Studies (MINORS) criteria.

Results:

The systematic review identified a total of 32 studies (level of evidence, 1-4) that met inclusion and exclusion criteria. Of the 32 studies, 5 reported on knotless TOE techniques, 25 reported on knot-tying TOE techniques, and 2 reported on both. In the knotless group, retear rates ranged from 6% to 36%, and Constant scores ranged from 38-65 (preoperative) to 73-83 (postoperative). In the knot-tying group, retear rates ranged from 0% to 48%, and Constant scores ranged from 42-64 (preoperative) to 55-96 (postoperative).

Conclusion:

Despite several theoretical advantages of knotless TOE repair, both knotless and knot-tying techniques reported considerable improvement in functional outcomes after rotator cuff repair. Although tendon failure rates showed a downward trend in knotless studies, additional prospective studies are warranted to better understand the role of medial-row fixation on tendon repair integrity and postoperative clinical outcomes.

Biomechanical Analysis of Medial-Row All-Suture Suture Anchor Fixation for Rotator Cuff Repair in a Pair-Matched Cadaveric Model

PURPOSE

To compare the biomechanical properties of all-suture suture anchors (ASSAs) with conventional suture anchors (CSAs) for double-row rotator cuff repair (RCR).

METHODS

Fourteen fresh-frozen human cadaveric shoulders were randomized into 2 RCR treatment groups: ASSA and CSA. All constructs received a double-row repair, with the lateral-row implants consisting of two 5.5-mm PEEK (polyether ether ketone) Footprint anchors. Each construct was loaded to a 10-N preload for 2 minutes, followed by cyclic loading from 10 to 160 N at a rate of 100 N/s for 100 cycles. Load-to-failure testing was performed immediately after cyclic loading testing at 1 mm/s from the zero position until failure. Cyclic creep, elongation amplitude, maximum load, stiffness, energy, and failure mode were recorded.

RESULTS

No significant difference in cyclic creep (P = .117) or elongation amplitude (P = .428) was found between the ASSA and CSA groups during cyclic testing. Three specimens in each group (43% in each) failed by the suture tearing through the tendon. The remaining specimens in each group failed by the anchor pulling out of the humeral head. The mean maximum load was 617.73 ± 177.77 N and 545.13 ± 212.98 N for the ASSA and CSA groups, respectively (P = .339). Maximum elongation before failure was not different between groups (P = .122). Mean energy and stiffness were not statistically different between the ASSA and CSA groups (P = .629 and P = .973, respectively).

CONCLUSIONS

In this cadaveric analysis with a simplified unidirectional experimental setup, failure mechanics and maximum load between the ASSA and CSA constructs were similar, with no difference in energy and stiffness. Although the ASSA group showed slightly larger elongation than the CSA group, these differences may not be clinically relevant.

CLINICAL RELEVANCE

This study provides a biomechanical head-to-head comparison of ASSAs and CSAs, indicating that ASSAs may be clinically equivalent to CSAs for use in an RCR.

Arthroscopic Transosseous Anchorless Rotator Cuff Repair Using the X-Box Technique

We describe a reproducible, step-by-step arthroscopic technique for anchorless transosseous rotator cuff repair using an X-box configuration with the Arthrotunneler device. The technique uses 2 bone tunnels and 4 high-strength sutures and is suitable for medium to large tears of the supra- and infraspinatus that would alternatively need a double-row repair with 4 anchors. Biomechanically, results appear to be similar as for anchored transosseous equivalent techniques. Enhanced biological healing and lower material costs are the possible benefits of this appealing arthroscopic approach that mimics the previous gold standard.

Is there a difference in clinical outcomes and repair integrity between arthroscopic single-row versus transosseous (anchorless) fixation? A retrospective comparative study

BACKGROUND

Few studies have investigated clinical and structural outcomes after transosseous (TO) repair. The purpose of this study was to compare structural and clinical outcomes of rotator cuff tear, repaired arthroscopically, with a single row (SR) or transossoeus (TO) anchorless technique.

METHODS

96 patients who underwent an arthroscopic repair for superior or posterosuperior rotator cuff tear using TO (n:54) or a SR (n:42) were retrospectively enrolled in this study after evaluation of clinical and surgical notes. Functional evaluation was performed with the adjusted Constant score, and American Shoulder and Elbow Surgeons (ASES) score. Postoperative cuff integrity was determined through MRI study.

RESULTS

Patients were recalled after a minimum follow-up of two years. All the patients were available for the study. In the SR group the Constant rating system showed a significant improvement from a preoperative average rating of 44.8 to an average of 85.7. In the group of TO repair the Constant rating system showed a significant improvement from a preoperative average of 46.1 to an average of 87.6 postoperatively. According to ASES index scores, the average total score improved from 42.8 to 92.0 in the anchor group and from 40.4 to 94.6 in the TO group. There was no statistical difference between the two groups about clinical outcomes. Postoperative MRI revealed no differences in term of complete re-tears between the two techniques. In the SR group at MRI we observe significant more cases of rotator cuff with a Sugaya type III healing.

CONCLUSIONS

Arthroscopic rotator cuff repair yielded successful clinical outcomes using SR and TO technique. However using the TO technique we saw less type 3 Sugaya readings on MRI suggesting a possible benefit with TO repair.

LEVEL OF EVIDENCE II

Retrospective study.

Editorial Commentary: "Knot" Less Strength at Half the Cost-Is It Time to Abandon Medial Row Anchors in Shoulder Double-Row Rotator Cuff Repair?

Transosseous equivalent rotator cuff repair is an expensive construct that has demonstrated biomechanical superiority when compared with other rotator cuff repair techniques. A novel transosseous knotless repair that substitutes medial row anchors for a transosseous tunnel rivals the biomechanical advantages of transosseous equivalent rotator cuff repair at half the cost and with reduced dependence on bone quality. Surgeons should carefully consider if "knotless transosseous is more."

Biomechanical Comparison of Transosseous Knotless Rotator Cuff Repair Versus Transosseous Equivalent Repair: Half The Anchors With Equivalent Biomechanics?

PURPOSE

To compare the biomechanics of a transosseous equivalent (TOE) repair using medial and lateral anchors with tape to a transosseous knotless (TOK) tape repair with only laterally placed intraosseous anchors.

METHODS

One of 2 different repairs were performed on 8 paired specimens: (1) transosseous equivalent (TOE) tape repair or (2) transosseous knotless (TOK) tape repair. Specimens were mounted on a materials testing machine and loaded in uniaxial tension to measure cyclic construct gap formation, followed by failure testing. Paired t tests were used to compare gapping, ultimate stiffness, and failure loads. Fisher exact test was used to compare modes of failure (soft tissue failure vs construct failure).

RESULTS

Peak cyclic gapping, failure stiffness, and ultimate failure loads did not differ between TOE and TOK repairs (P = .140 for gapping, P = .106 for stiffness, and P = .672 for peak failure loads). All TOK repairs failed via soft tissue failure medial to the medial suture line, with no construct failures. TOE repairs failed more often through construct failure (anchor migration or suture-bone interface cut through) than TOK repairs (P = .026).

CONCLUSION

TOK repairs only failed through soft tissue whereas TOE repairs failed through both soft tissue and the repair construct. Despite 50% fewer suture anchors in the TOK repairs than the TOE repairs, cyclic gapping and ultimate stiffness and failure loads were not significantly different.

CLINICAL RELEVANCE

The transosseous knotless construct presented is a 2-anchor construct that is equivalent in biomechanical function to a traditional 4-anchor construct, reducing anchor load in the tuberosity.

Functional and Radiographic Outcomes After Arthroscopic Transosseous Suture Repair of Medium Sized Rotator Cuff Tears

PURPOSE

To evaluate the functional and anatomical outcomes after arthroscopic transosseous suture (TOS) repair of 2 to 4 cm sized rotator cuff tears and to identify preoperative factors influencing repair failure.

METHODS

From May 2013 to August 2014, patients with symptomatic 2 to 4 cm full-thickness tears underwent arthroscopic TOS repair, and those who could be followed up for a minimum of 2 years were included in this retrospective study. Functional and anatomical outcomes were analyzed up to 2 years postoperatively. Factors affecting cuff repair failure were evaluated, using both univariate and multivariate analyses.

RESULTS

Twenty-seven patients were included. On preoperative magnetic resonance imaging data, the mean anteroposterior dimension tear size was 27.0 ± 3.3 mm and mean retraction was 30.7 ± 3.1 mm. Anatomic failure (Sugaya III, IV, and V) rate was 33% with arthroscopic TOS repair; however, significant improvements were found regardless of cuff healing. Mean American Shoulder and Elbow Surgeons score (range, 0-100) improved from 48.8 ± 16.6 preoperatively to 80.1 ± 11.1 postoperatively (P < .001), mean Constant score (range, 0-100) improved from 54.5 ± 11.8 to 73.7 ± 8.5 (P < .001), and mean pain visual analog scale score (range, 0-10) improved from 3.9 ± 1.7 to 2.0 ± 1.1 (P < .001). These changes reached each minimal clinically important difference previously reported. Greater tear size in anteroposterior dimension (P = .034), decreased acromiohumeral distance (P = .022), and higher fatty infiltration of supraspinatus (P = .011) were independent preoperative factors associated with repair failure. Twelve patients (44%) experienced intraoperative bone laceration.

CONCLUSIONS

Arthroscopic TOS repair was a reliable technique for patients with 2 to 4 cm size rotator cuff tear. Preoperative factors associated with cuff repair failure were greater tear size in anteroposterior dimension, decreased acromiohumeral distance, and higher fatty infiltration of supraspinatus.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Pullout strength of cement-augmented and wide-suture transosseous fixation in the greater tuberosity

BACKGROUND

Obtaining strong fixation in low-density bone is increasingly critical in surgical repair of rotator cuff tears because of the aging population. To evaluate two new methods of improving pullout strength of transosseous rotator cuff repair in low-density bone, we analyzed the effects of 1) using 2-mm suture tape instead of no. 2 suture and 2) augmenting the lateral tunnel with cement.

METHODS

Eleven pairs of osteopenic or osteoporotic cadaveric humeri were identified by dual-energy x-ray absorptiometry. One bone tunnel and one suture were placed in the heads of 22 specimens. Five randomly selected pairs were repaired with no. 2 suture; the other six pairs were repaired with 2-mm suture tape. One side of each pair received lateral tunnel cement augmentation. Specimens were tested to suture pullout. Data were fitted to multivariate models that accounted for bone mineral density and other specimen characteristics.

FINDINGS

Two specimens were excluded because of knot-slipping during testing. Use of suture tape versus no. 2 suture conferred a 75-N increase (95% CI: 37, 113) in pullout strength (P<0.001). Cement augmentation conferred a 42-N improvement (95% CI: 10, 75; P=0.011). Other significant predictors of pullout strength were age, sex, and bone mineral density.

INTERPRETATION

We show two methods of improving the fixation strength of transosseous rotator cuff repairs in low-density bone: using 2-mm suture tape instead of no. 2 suture and augmenting the lateral tunnel with cement. These methods may improve the feasibility of transosseous repairs in an aging patient population.

Anchored Transosseous-Equivalent Versus Anchorless Transosseous Rotator Cuff Repair: A Biomechanical Analysis in a Cadaveric Model

BACKGROUND

The original approach for the repair of torn rotator cuffs involved an open technique with sutures passing through the greater tuberosity and tendon. The development of suture anchors allowed for an all-arthroscopic approach with anchor configurations attempting to re-create a transosseous fixation pattern. Presently, an arthroscopic approach can be combined with a transosseous suture configuration without using anchors.

PURPOSE

To evaluate cyclic loading, ultimate load to failure, and the failure mechanisms of transosseous-equivalent (TOE) repair with anchors and anchorless transosseous (AT) repair of rotator cuff tears.

STUDY DESIGN

Controlled laboratory study.

METHODS

Supraspinatus tears (25 mm) were created in 20 fresh-frozen, human cadaveric shoulders, which were randomized to TOE or AT repair (10 in each group, paired experimental design). Biomechanical testing was performed with an initial preload, cyclic loading, and load to failure. Optical markers were used to monitor gap formation in 3 planes, and the failure mode was recorded. Paired t tests were used to make comparisons of biomechanical parameters between the groups. Multinomial logistic regression was used to compare failure modes between the groups. Significance was set to .05.

RESULTS

The TOE group had a significantly higher mean (±SD) ultimate failure load (578.5 ± 123.8 N) than the AT group (468.7 ± 150.9 N) ( P = .034). The TOE group also had a significantly less mean first-cycle excursion (2.97 ± 1.97 mm) than the AT group (4.70 ± 2.04 mm) ( P = .046). There were no significant differences between the groups in cyclic elongation or linear stiffness during cyclic loading. Primary modes of failure were a type 2 tendon tear with medial tendon disruption in the TOE group (7/10) and a type 1 tendon tear with lateral tendon disruption in the AT group (6/10).

CONCLUSION

TOE repair resulted in a significantly higher mean failure load compared with AT repair in a cadaveric model. The most common modes of failure were a type 2 tendon tear in the TOE group and a type 1 tendon tear in the AT group.

CLINICAL RELEVANCE

A higher mean failure load in TOE versus AT constructs may come at the cost of a less favorable failure mode adjacent to medial anchors at the musculotendinous junction, potentially making revision difficult.

Suture spanning augmentation of single-row rotator cuff repair: a biomechanical analysis

BACKGROUND

This in vitro study evaluated the biomechanical benefit of adding spanning sutures to single-row rotator cuff repair.

METHODS

Mechanical testing was performed to evaluate 9 pairs of cadaveric shoulders with complete rotator cuff repairs, with a single-row technique used on one side and the suture spanning technique on the other. The spanning technique included sutures from 2 lateral anchors securing tendon near the musculotendinous junction, spanning the same anchor placement from single-row repair. The supraspinatus muscle was loaded to 100 N at 0.25 Hz for 100 cycles, followed by a ramp to failure. Markers and a video tracking system measured anterior and posterior gap formation across the repair at 25-cycle intervals. The force at which the stiffness decreased by 50% and 75% was determined. Data were compared using paired t-tests.

RESULTS

One single-row repair failed at <25 cycles. Both anterior and posterior gap distances tended to be 1 to 2 mm larger for the single-row repairs than for the suture spanning technique. The difference was statistically significant at all cycles for the posterior gap formation (P ≤ .02). The trends were not significant for the anterior gap (P ≥ .13). The loads at which the stiffness decreased by 50% and 75% did not differ significantly between the 2 types of repair (P ≥ .10).

CONCLUSIONS

The suture spanning technique primarily improved posterior gap formation. Decreased posterior gap formation could reduce failure rates for rotator cuff repair.

Biomechanical Performance of Medial Row Suture Placement Relative to the Musculotendinous Junction in Transosseous Equivalent Suture Bridge Double-Row Rotator Cuff Repair

PURPOSE

To compare the biomechanical performance of medial row suture placement relative to the musculotendinous junction (MTJ) in a cadaveric transosseous equivalent suture bridge (TOE-SB) double-row (DR) rotator cuff repair (RCR) model.

METHODS

A TOE-SB DR technique was used to reattach experimentally created supraspinatus tendon tears in 9 pairs of human cadaveric shoulders. The medial row sutures were passed either near the MTJ (MTJ group) or 10 mm lateral to the MTJ (rotator cuff tendon [RCT] group). After the supraspinatus repair, the specimens underwent cyclic loading and load to failure tests. The localized displacement of the markers affixed to the tendon surface was measured with an optical tracking system.

RESULTS

The MTJ group showed a significantly higher (P = .03) medial row failure (5/9; 3 during cyclic testing and 2 during load to failure testing) compared with the RCT group (0/9). The mean number of cycles completed during cyclic testing was lower in the MTJ group (77) compared with the RCT group (100; P = .07) because 3 specimens failed in the MTJ group during cyclic loading. There were no significant differences between the 2 study groups with respect to biomechanical properties during the load to failure testing.

CONCLUSIONS

In a cadaveric TOE-SB DR RCR model, medial row sutures through the MTJ results in a significantly higher rate of medial row failure.

CLINICAL RELEVANCE

In rotator cuff tears with tendon tissue loss, passage of medial row sutures through the MTJ should be avoided in a TOE-SB RCR technique because of the risk of medial row failure.

Immediate costs of mini-open versus arthroscopic rotator cuff repair in an Asian population

OBJECTIVE

While there has been increasing interest in minimally invasive surgery, the expenses incurred by patients undergoing this form of surgery have not been comprehensively studied. The authors compared the costs borne by patients undergoing arthroscopic rotator cuff repair with the standard mini-open repair at a tertiary hospital in an Asian population.

PATIENTS AND METHODS

This was a retrospective cohort study. The authors studied the inpatient hospital bills of patients following rotator cuff tear repair between January 2010 and October 2014 via the hospital electronic medical records system. 148 patients had arthroscopic repair and 78 had mini-open repair. The cost of implants, consumables, and the total cost of hospitalization were analyzed. Operative times and length of stay for both procedures were also studied. Constant scores and American Shoulder Elbow Scores (ASES) were recorded preoperatively and at 1 year postoperatively.

RESULTS

Three fellowship-trained surgeons performed arthroscopic repairs and one performed the mini-open repair. The cost of implants and consumables was significantly higher with arthroscopic repair. The duration of surgery was also significantly longer with that technique. There was no difference in length of stay between the two techniques. There was also no difference in Constant scores or ASES scores, both preoperatively and at 1 year postoperatively.

CONCLUSIONS

The immediate costs of mini-open repair of rotator cuff tears are significantly less than that of arthroscopic repair. Most of the difference arises from the cost of implants and consumables. Equivalent functional outcomes from both techniques suggest that mini-open repair may be more cost-effective.

[Patch augmentation of the rotator cuff. A reasonable choice or a waste of money?]

BACKGROUND

Although reconstruction methods have improved, tendon retears remain a major complication associated with rotator cuff repair. With the application of patches, either by interposition or by augmentation, surgeons can attempt to close an irreparable cuff defect or improve the mechanical and biological properties of tendons respectively.

OBJECTIVES

Which factors need to be considered when using a patch and what outcome can be expected?

MATERIALS AND METHODS

Based on the current literature, an overview of the techniques and materials in use and biomechanical and clinical experience is provided.

RESULTS

The literature shows clear improvements in the biomechanical properties of a repair with patch augmentation; in particular, weakened tendons of the anterior supraspinatus and superior infraspinatus benefit most. It is important to keep in mind that each patch material has its own individual properties, which makes comparison of the various patch types difficult. The current scientific evidence is promising, although larger level 1 studies are still required.

CONCLUSIONS

The general use of patches cannot be recommended at this time. Nevertheless, the use of a patch should be considered in patients who are at a high risk of recurrent retears. In future, patches will probably be applied mainly as part of a combined effort, together with biological measures to further reduce retear rates.

Biomechanical study comparing 3 fixation methods for rotator cuff massive tear: Transosseous No. 2 suture, transosseous braided tape, and double-row

BACKGROUND

Important rotator cuff repair failure rates have prompted this study of the techniques and materials used in order to optimize clinical results.

QUESTIONS/PURPOSES

Is the reconstruction of the rotator cuff biomechanically stronger when using: 1) transosseous with 2 mm braided tape suture (TOT), 2) transosseous with multi-strand No. 2 sutures (TOS), or 3) double row suture bridge with suture anchors loaded with No. 2 braided sutures (DRSB)?

METHODS

Twenty-four cadaveric pig shoulders were randomized in the three repair constructs. The infraspinatus muscle was detached to mimic a complete laceration, repaired with one of the three repair groups and tested with a traction machine. Cameras recorded tendon displacement during trials. The ultimate strength (US), failure mode, and tendon displacement, qualified by the bare footprint area (BFA), during cycling phases were compared.

RESULTS

The US for DRSB was 175 ± 82 Newton (N), 91 ± 51 N for TOS, and 147 ± 63 N for TOT. The BFA after 200 cycles was 81 ± 34% for TOS, 57 ± 41% for TOT, and 26 ± 27% for DRSB repairs. No significant difference was observed between the DRSB and TOT results for US or BFA percentage of loss during all the cycling phases. TOS proved to be weaker than TOT and DRSB.

CONCLUSION

All the ruptures occurred in the tendon, which seems to be the weakness of rotator cuff repairs. The use of braided tape suture with a transosseous technique seems to be a cost effective, equivalent alternative implant compared to anchor fixation.

The Medial Stitch in Transosseous-Equivalent Rotator Cuff Repair: Vertical or Horizontal Mattress?

BACKGROUND

Despite advances in surgical technique, rotator cuff repair retears continue to occur at rates of 10%, 22%, and 57% for small, medium, and large tears, respectively. A common mode of failure in transosseous-equivalent rotator cuff repairs is tissue pullout of the medial mattress stitch. While the medial mattress stitch has been studied extensively, no studies have evaluated a vertical mattress pattern placed near the musculotendinous junction in comparison with a horizontal mattress pattern.

HYPOTHESIS

Vertical mattress stitches will have higher load to failure and lower gapping compared with horizontal mattress stitches in a transosseous-equivalent rotator cuff repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

Double-row transosseous-equivalent rotator cuff repairs were performed in 9 pairs of human male cadaveric shoulders (mean age ± SD, 58 ± 10 years). One shoulder in each pair received a medial-row suture pattern using a vertical mattress stitch, and the contralateral shoulder received a horizontal mattress. Specimens were mounted in a materials testing machine and tested in uniaxial tensile deformation for cyclic loading (500 cycles at 1 Hz to 1.0 MPa of effective stress), followed by failure testing carried out at a rate of 1 mm/s. Construct gapping and applied loads were monitored continuously throughout the testing.

RESULTS

Vertical mattress sutures were placed in 5 right and 4 left shoulders. Peak cyclic gapping did not differ between vertical (mean ± SD, 2.8 ± 1.1 mm) and horizontal mattress specimens (3.0 ± 1.2 mm) (P = .684). Vertical mattress sutures failed at higher loads compared with horizontal mattress sutures (568.9 ± 140.3 vs 451.1 ± 174.3 N; P = .025); however, there was no significant difference in failure displacement (8.0 ± 1.6 vs 6.0 ± 2.1 mm; P = .092). Failure stiffness did not differ between the suture patterns (P = .204).

CONCLUSION

In transosseous-equivalent rotator cuff repairs near the musculotendinous junction, a vertical mattress suture used as the medial stitch has a higher load to failure but no difference in gapping compared with a horizontal mattress pattern.

CLINICAL RELEVANCE

A vertical mattress suture may offer enhanced strength of repair for transosseous-equivalent repairs.

Does Pure Platelet-Rich Plasma Affect Postoperative Clinical Outcomes After Arthroscopic Rotator Cuff Repair? A Randomized Controlled Trial

BACKGROUND

The exact role of platelet-rich plasma (PRP) in rotator cuff tendon reconstruction remains unclear.

PURPOSE/HYPOTHESIS

This study investigated whether an intraoperative pure PRP injection, compared with a local anesthetic injection, improves patient-reported outcomes at 3 and 6 months after arthroscopic rotator cuff repair. The hypothesis was that pure PRP improves patient-reported outcomes (Oxford Shoulder Score [OSS]) at 3 and 6 months after surgery and has the same pain-reducing effect compared with a postoperative subacromial local anesthetic (ropivacaine) injection.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Between January 2011 and November 2012, a total of 120 patients who underwent arthroscopic double-row repair of a supraspinatus tendon rupture were randomized to receive either pure PRP by an injection at the footprint (PRP group; n = 60) or ropivacaine injected in the subacromial region (control group; n = 60). Seventy-eight percent of patients had other concomitant tears. All patients, surgeons, and follow-up investigators were blinded. Clinical parameters and various outcome scores (Constant-Murley shoulder score; OSS; patient American Shoulder and Elbow Surgeons score; quick Disabilities of the Arm, Shoulder and Hand score; EuroQol 5 dimensions) were documented preoperatively and at 3, 6, and 24 months postoperatively. The repair integrity was assessed by magnetic resonance imaging or ultrasound at 24 months. Furthermore, a pain diary was completed within the first 10 postoperative days, and adverse events were recorded. Group outcome differences were analyzed using t tests, Fisher exact tests, and mixed models.

RESULTS

The final follow-up rate was 91%. An associated tear of the subscapularis tendon was diagnosed in 23% of PRP-treated patients and 36% of control patients. Three months after surgery, the mean (±SD) OSS was 32.9 ± 8.6 in PRP-treated patients and 30.7 ± 10.0 in control patients (P = .221). No significant differences were noted for other outcome parameters as well as at 6 and 24 months postoperatively. Smoking was a significant effect modifier. Pain for both groups decreased from postoperative day 1 to 10 without any significant group difference (P = .864). Six (12.2%) and 11 (20.8%) patients were diagnosed with a recurrent supraspinatus tendon defect in the PRP and control groups, respectively (P = .295). Twenty-two (40.7%) and 18 (30.5%) PRP-treated and control patients, respectively, experienced a local adverse event within 24 months (P = .325).

CONCLUSION

Patients treated with pure PRP showed no significantly improved function at 3, 6, and 24 months after arthroscopic repair compared with control patients receiving ropivacaine; however, a similar pain reduction was documented in both groups. The negative influence of smoking on the effect of pure PRP requires further investigation.

REGISTRATION

NCT01266226 (ClinicalTrials.gov).

Biomechanical Evaluation of Suture Anchor Versus Transosseous Tunnel Quadriceps Tendon Repair Techniques

PURPOSE

To evaluate the biomechanical fixation strength of suture anchor and transosseous tunnel repair of the quadriceps tendon in a standardized cadaveric repair model.

METHODS

Twelve "patella-only" specimens were used. Dual-energy X-ray absorptiometry measurement was performed to ensure equal bone quality amongst groups. Specimens were randomly assigned to either a suture anchor repair of quadriceps tendon group (n = 6) or a transosseous tunnel repair group (n = 6). Suture type and repair configuration were equivalent. After the respective procedures were performed, each patella was mounted into a gripping jig. Tensile load was applied at a rate of 0.1 mm/s up to 100 N after which cyclic loading was applied at a rate of 1 Hz between magnitudes of 50 to 150 N, 50 to 200 N, 50 to 250 N, and tensile load at a rate of 0.1 mm/s until failure. Outcome measures included load to failure, displacement at 1st 100 N load, and displacement after each 10th cycle of loading.

RESULTS

The measured cyclic displacement to the first 100 N, 50 to 150 N, 50 to 200 N, and 50 to 250 N was significantly less for suture anchors than transosseous tunnels. There was no statistically significant difference in ultimate load to failure between the 2 groups (P = .40). Failure mode for all suture anchors except one was through the soft tissue. Failure mode for all transosseous specimens but one was pulling the repair through the transosseous tunnel.

CONCLUSIONS

Suture anchor quadriceps tendon repairs had significantly decreased gapping during cyclic loading, but no statistically significant difference in ultimate load to failure when compared with transosseous tunnel repairs. Although suture anchor quadriceps tendon repair appears to be a biomechanically superior construct, a clinical study is needed to confirm this technique as a viable alternative to gold standard transosseous techniques.

CLINICAL RELEVANCE

Although in vivo studies are needed, these results support the suture anchor technique as a viable alternative to transosseous repair of the quadriceps tendon.

Midterm clinical outcomes following arthroscopic transosseous rotator cuff repair

PURPOSE

Arthroscopic transosseous (TO) rotator cuff repair has recently emerged as a new option for surgical treatment of symptomatic rotator cuff tears. Limited data is available regarding outcomes using this technique. This study evaluated midterm clinical outcomes following a novel arthroscopic TO (anchorless) rotator cuff repair technique.

MATERIALS AND METHODS

A consecutive series of 107 patients and 109 shoulders underwent arthroscopic TO (anchorless) rotator cuff repair for a symptomatic full-thickness tear. Pre and postoperative range of motion (ROM) was compared at an average of 11.8 months. Postoperative outcome scores were obtained at an average of 38.0 months. Statistical analysis was performed to compare pre and postoperative ROM data. Univariate analysis was performed using Student's t-test to compare the effect of other clinical characteristics on final outcome.

RESULTS

Statistically significant improvements were noted in forward flexion, external rotation and internal rotation (P < 0.0001). Average postoperative subjective shoulder value was 93.7, simple shoulder test 11.6, and American Shoulder and Elbow Surgeons (ASES) score 94.6. According to ASES scores, results for the 109 shoulders available for final follow-up were excellent in 95 (87.1%), good in 8 (7.3%), fair in 3 (2.8%), and poor in 3 (2.8%). There was no difference in ROM or outcome scores in patients who underwent a concomitant biceps procedure (tenodesis or tenotomy) compared with those who did not. Furthermore, there was no significant difference in outcome between patients who underwent either biceps tenodesis or tenotomy. Age, history of injury preceding the onset of pain, tear size, number of TO tunnels required to perform the repair, and presence of fatty infiltration did not correlate with postoperative ROM or subjective outcome measures at final follow-up. Two complications and four failures were noted.

CONCLUSIONS

Arthroscopic TO rotator cuff repair technique leads to statistically significant midterm improvement in ROM and satisfactory midterm subjective outcome scores with low complication/failure rates in patients with average medium-sized rotator cuff tears with minimal fatty infiltration. Further work is required to evaluate radiographic healing rates with this technique and to compare outcomes following suture anchor repair.

LEVEL OF EVIDENCE

Level IV.

Suture Technique Influences the Biomechanical Integrity of Pectoralis Major Repairs

Pectoralis major ruptures occur in large, muscular individuals, and repair constructs may experience significant tension. Four different suture techniques were evaluated biomechanically to determine the effect of suture technique on optimizing fixation strength. Forty fresh-frozen cadaveric shoulders were repaired using endosteal buttons. The control group was repaired with #2 polyblend suture in a modified Mason-Allen stitch configuration. The triple group was repaired using the same suture and configuration, but with the addition of triple-loaded buttons. The configuration group was repaired using the same suture in a Krackow/Bunnell configuration. The tape group was repaired using 2-mm polyethylene tape and #5 polyblend suture in the Krackow/Bunnell configuration. Under cyclic loading, there was no significant difference between groups. Under load-to-failure testing, the tape group withstood a significantly greater maximum load (726.0±90.0 N) than the control and triple groups (330.2±20.2 and 400.2±35.2 N, respectively; P<.005), and similar load to the configuration group (509.9±68.6 N; P=.16). The configuration group failed via suture breakage (9/10); the other groups failed via suture pullout, in which suture pulled through tendon (26/30). Pectoralis major repair in a running, locked configuration appears to improve biomechanical performance by preventing suture pullout. Use of a polyethylene tape construct demonstrates the potential for improved failure loads, but its role remains undefined.

Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices

Bone quality is one of the reported factors influencing the success of bone anchors in arthroscopic repairs of torn rotator cuffs at the shoulder. This work was aimed at developing refined numerical methods to investigate how bone quality can influence the fixation stiffness of bone anchors. To do that bone biopsies were scanned at 26-μm resolution with a high-resolution microcomputer tomography (micro-CT) scanner and their images were processed for virtual implantation of a typical design of bone anchor. These were converted to microfinite element (μFE) and homogenized classical FE models, and analyses were performed to simulate pulling on the bone anchor with and without cement augmentation. Quantification of structural stiffness for each implanted specimen was then computed, as well as stress distributions within the bone structures, and related to the bone volume fraction of the specimens. Results show that the classical method is excellently correlated to structural predictions of the more refined μFE method, despite the qualitative differences in local stresses in the bone surrounding the implant. Predictions from additional loading cases suggest that structural fixation stiffness in various directions is related to apparent bone density of the surrounding bone. Augmentation of anchoring with bone cement stiffens the fixation and alters these relations. This work showed the usability of homogenized FE (hFE) in the evaluation of bone anchor fixation and will be used to develop new methodologies for virtual investigations leading to optimized repairs of rotator cuff and glenoid Bankart lesions.

Load to Failure and Stiffness: Anchor Placement and Suture Pattern Effects on Load to Failure in Rotator Cuff Repairs

BACKGROUND

Rotator cuff tendinopathy is a frequent cause of shoulder pain that can lead to decreased strength and range of motion. Failures after using the single-row technique of rotator cuff repair have led to the development of the double-row technique, which is said to allow for more anatomical restoration of the footprint.

PURPOSE

To compare 5 different types of suture patterns while maintaining equality in number of anchors. The hypothesis was that the Mason-Allen-crossed cruciform transosseous-equivalent technique is superior to other suture configurations while maintaining equality in suture limbs and anchors.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 25 fresh-frozen cadaveric shoulders were randomized into 5 suture configuration groups: single-row repair with simple stitch technique; single-row repair with modified Mason-Allen technique; double-row Mason-Allen technique; double-row cross-bridge technique; and double-row suture bridge technique. Load and displacement were recorded at 100 Hz until failure. Stiffness and bone mineral density were also measured.

RESULTS

There was no significant difference in peak load at failure, stiffness, maximum displacement at failure, or mean bone mineral density among the 5 suture configuration groups (P < .05).

CONCLUSION

According to study results, when choosing a repair technique, other factors such as number of sutures in the repair should be considered to judge the strength of the repair.

CLINICAL RELEVANCE

Previous in vitro studies have shown the double-row rotator cuff repair to be superior to the single-row repair; however, clinical research does not necessarily support this. This study found no difference when comparing 5 different repair methods, supporting research that suggests the number of sutures and not the pattern can affect biomechanical properties.

Suture anchor repair yields better biomechanical properties than transosseous sutures in ruptured quadriceps tendons

PURPOSE

This human cadaveric study compares the biomechanical properties of quadriceps tendon repair with suture anchors and the commonly applied transosseous sutures. The hypothesis was that suture anchors provide at least equal results concerning gap formation and ultimate failure load compared with transosseous suture repair.

METHODS

Thirty human cadaveric knees underwent tenotomy followed by repair with either 5.5-mm-double-loaded suture anchors [titanium (TA) vs. resorbable hydroxyapatite (HA)] or transpatellar suture tunnels using No. 2 Ultrabraid™ and the Krackow whipstitch. Biomechanical analysis included pretensioning the constructs with 20 N for 30 s and then cyclic loading of 250 cycles between 20 and 100 N at 1 Hz in a servohydraulic testing machine with measurement of elongation. Ultimate failure load analysis and failure mode analysis were performed subsequently.

RESULTS

Tendon repairs with suture anchors yielded significantly less gap formation during cyclic loading (20th-250th cycle: TA 1.9 ± 0.1, HA 1.5 ± 0.5, TS 33.3 ± 1.9 mm, p < 0.05) and resisted significantly higher ultimate failure loads (TA 740 ± 204 N, HA 572 ± 67 N, TS 338 ± 60 N, p < 0.05) compared with transosseous sutures. Common failure mode was pull-out of the eyelet within the suture anchor in the HA group and rupture of the suture in the TA and TS group.

CONCLUSION

Quadriceps tendon repair with suture anchors yields significantly better biomechanical results than the commonly applied transosseous sutures in this human cadaveric study. These biomechanical findings may change the future clinical treatment for quadriceps tendon ruptures. Randomised controlled clinical trials are desirable for the future.

LEVEL OF EVIDENCE

Not applicable, controlled laboratory human cadaveric study.

Suture placement near the musculotendinous junction in the supraspinatus: implications for rotator cuff repair

BACKGROUND

Transosseous-equivalent rotator cuff repair has an increased incidence of medial rotator cuff failure compared with single-row repair. No studies have evaluated the influence of the proximity of the suture row to the musculotendinous junction (MTJ) on cyclic gapping and failure properties.

HYPOTHESIS

A single row of horizontal mattress sutures placed within the supraspinatus tendon lateral to the MTJ will experience less gap formation and higher failure loads than a similar suture row placed at the MTJ.

STUDY DESIGN

Controlled laboratory study.

METHODS

Paired supraspinatus tendons were isolated from human cadaveric specimens and resected at the tendon insertion to the humerus. Randomized within a pair, a single row of 4 horizontal mattress sutures was placed either in the tendon 5 mm lateral to the MTJ or at the MTJ. The tied sutures secured the tendon to a fixture that ensured consistent placement of the suture row in the tendon and static fixation of the row. The muscle belly was gripped in a cryoclamp, and a servohydraulic materials testing machine was used to provide uniaxial tensile deformation for 500 cycles at 1 Hz, followed by load to failure at 1 mm/s. Fiducial markers with video tracking were used to quantify gap formation at the suture line, while the materials testing machine recorded loading for the cyclic and failure tests.

RESULTS

During cyclic loading, both constructs experienced gross initial gap formation, followed by progressive gap formation that plateaued after cycle 200. The MTJ specimens had significantly higher mean cumulative gapping than the tendon specimens: 3.6±1.0 mm versus 2.4±0.6 mm, respectively (P=.012). The tendon specimens had significantly higher mean loads to failure than did the MTJ specimens: 567.1±121.8 N versus 434.2±148.1 N, respectively (P=.013). The mean failure displacement did not differ between groups for the tendon and MTJ: 5.7±2.5 mm versus 4.5±2.0 mm, respectively (P=.144).

CONCLUSION

A horizontal suture row placed at the MTJ has inferior mechanical properties (increased gapping, decreased load support) as compared with a suture row placed 5 mm laterally within the tendon.

CLINICAL RELEVANCE

The integrity of rotator cuff repair may be compromised if sutures are placed too close to the MTJ.

Hybrid Repair of Large Crescent Rotator Cuff Tears Using a Modified SpeedBridge and Double-Pulley Technique

An ideal rotator cuff repair maximizes the tendon-bone interface and has adequate biomechanical strength that can withstand a high level of demand. Arthroscopic transosseous-equivalent rotator cuff repairs have become popular and have been shown to be superior to many other methods of fixation. We present an alternative method of repair for large crescent rotator cuff tears that combines 2 well-known methods of fixation: modified SpeedBridge (Arthrex, Naples, FL) and double-pulley techniques. These 2 repair constructs were combined to provide the greatest amount of compression across the footprint while also providing rigid fixation. Ultimately, this can provide an optimal environment for healing in otherwise significant injuries.

Gap formation in a transosseous rotator cuff repair as a function of bone quality

BACKGROUND

The transosseous approach has been well known for a long time as a valid repair approach. Over time, various criticisms have been raised over this technique principally classifiable in two main categories: technical difficulty and related reproducibility in an arthroscopic environment, and repair stability (in the suture-bone contact area). About cyclic performance, several authors have conceived test setups with the aim of simulating a real environment in dynamic load conditions. The aim of this study was to monitor gap formation in a cyclic test setup.

METHODS

The performance (measured as gap formation) has been monitored as a function of bone density to verify the effect of the latter. The test blocks have been shaped using sawbones® test bricks (Malmo, Sweden) of different densities, and the following values have been tested: 10, 15, 20, 30 and 40pcf.

FINDINGS

The comparison has been made between the two groups: traditional transosseous and new approach with an interposed device. Regarding the traditional transosseous approach in a 10-pcf environment, not even the first loading cycle was completed, the whole bone bridge was destroyed in the first loading ramp and no further loading capability was present in the repair. By increasing the block density, the surface damage in the suture-block contact decreased.

INTERPRETATION

With this work, it has been demonstrated how the traditional transosseous approach is strongly influenced by the bone quality up to the point where, in certain conditions, a safe and reliable repair is not guaranteed.

A new anchor augmentation technique with a cancellous screw in osteoporotic rotator cuff repair: an in vitro biomechanical study on sheep humerus specimens

PURPOSE

The aim of this study was to test a simple technique to augment the pullout resistance of an anchor in an over-drilled sheep humerus model.

METHODS

Sixty-four paired sheep humeri were harvested from 32 male sheep aged 18 months. Specimens were divided into an augmented group and non-augmented group. FASTIN RC 5-mm titanium screw anchors (DePuy Mitek, Raynham, MA) double loaded with suture material (braided polyester, nonabsorbable USP No. 2) were used in both groups. Osteoporosis was simulated by over-drilling with a 4.5-mm drill. Augmentation was performed by fixing 1 of the sutures 1.5 cm inferior to the anchor insertion site with a washer screw. This was followed by a pull-to-failure test at 50 mm/min. The ultimate load (the highest value of strength before anchor pullout) was recorded. A paired t test was used to compare the biomechanical properties of the augmented and non-augmented groups.

RESULTS

In all specimens the failure mode was pullout of the anchor. The ultimate failure loads were statistically significantly higher in the augmented group (P < .0001). The mean pullout strength was 121.1 ± 10.17 N in the non-augmented group and 176.1 ± 10.34 N in the augmented group.

CONCLUSIONS

The described augmentation technique, which is achieved by inferior-lateral fixation of 1 of the sutures of the double-loaded anchor to a fully threaded 6.5-mm cancellous screw with a washer, significantly increases the ultimate failure loads in the over-drilled sheep humerus model.

CLINICAL RELEVANCE

Our technique is simple, safe, and inexpensive. It can be easily used in all osteoporotic patients and will contribute to the reduction of anchor failure. This technique might be difficult to apply arthroscopically. Cannulated smaller screws would probably be more practical for arthroscopic use. Further clinical studies are needed.

The evolution of suture anchors in arthroscopic rotator cuff repair

The advancement of suture anchor design and technology has fostered the transition from open to arthroscopic rotator cuff repair. Current suture-bridging constructs have greatly surpassed the biomechanical strength parameters of transosseous repairs and have shown impressive healing rates after arthroscopic rotator cuff repair. This review describes this evolution and discusses the important characteristics of suture anchors.