Biomechanical evaluation of a single-row versus double-row repair for complete subscapularis tears

The Primary Stability of Arthroscopic Subscapularis Tendon Repair Depends on the Suture Technique: A Biomechanical Evaluation of 4 Different Repair Techniques

Background

Numerous single- and double-row repair techniques with simple and modified stitches have been described for subscapularis tendon tears.

Purpose/Hypothesis

This study aimed to uniformly evaluate the influence of 4 different repair techniques on the biomechanical performance of fixation for full-thickness subscapularis tendon tears. It was hypothesized that (1) the 2 modified single-row repair techniques would require more cycles to result in 3- and 5-mm gap formation and have a higher load to failure after cyclic loading than the simple single-row repair technique and (2) the double-row repair technique would also require more cycles to result in 3- and 5-mm gap formation and have a significantly higher load to failure after cyclic loading compared to the simple single-row repair technique.

Study Design

Controlled laboratory study.

Methods

Full-thickness subscapularis tendon tears were created in 32 fresh-frozen cadaveric shoulders, and the tears were treated in 1 of 4 ways: (1) single-row repair with the mattress stitch, (2) single-row repair with the modified lasso-loop stitch, (3) single-row repair with the modified Mason-Allen stitch, or (4) double-row repair. After repair, specimens were progressively cyclically loaded to 200 N, and the number of cycles to obtain a 3- and 5-mm gap was recorded. After cyclic loading, the specimens were loaded to failure at 500 mm/min, and ultimate failure loads were measured.

Results

There were no significant differences between either of the modified single-row repair techniques and the simple single-row repair technique. Double-row repair withstood significantly more cycles until 3-mm (P < .001) and 5-mm (P = .004) gap formation and had a higher ultimate failure load (P = .015) compared to the simple single-row repair technique, and double-row repair withstood more cycles until 3-mm gap formation (P = .003) compared with single-row repair with the modified lasso-loop stitch. No significant differences were found between double-row repair and single-row repair with the modified Mason-Allen stitch.

Conclusion

Findings indicated that (1) there was no significant biomechanical advantage of the modified single-row repair techniques over the simple single-row repair technique and (2) while the double-row repair technique was biomechanically superior to the simple single-row repair technique, there was no significant difference between single-row repair with the modified Mason-Allen stitch and double-row repair.

Clinical Relevance

Considering that double-row repair might not be useful in some tears because of the risk of overtensioning, modified single-row repair techniques appear to be an adequate refixation alternative.

Three-Point Contact Repair Technique for Partial Subscapularis Tears Using U-Stitch and Cow Hitch Knot Loaded on a Single Knotless Anchor: Simple, Reliable and Quick Method

The importance of repairing the subscapularis tendon to facilitate restoration of the rotator cuff force couple is obvious. However, identifying and repairing subscapularis tears can be challenging for surgeons. In this technical note, we present our preferred surgical method for Lafosse type 1, 2, and 3 and Yoo and Rhee type 1-2A and 2B subscapularis tears, providing a 3-point suture contact achieved with FiberTape (Arthrex) and knotless anchors. In this technique, fiber suture is placed into the superolateral edge of the subscapularis tendon as a traction stitch (cow hitch knot). Second, the FiberTape is passed through the medial upper and lower parts of the tendon, just perpendicular to the fibers, using a suture passer. The FiberTape's free ends remain on the tendon's anterior side, shaping a U form. The U-shaped FiberTape and traction suture are loaded to a knotless anchor and placed on the footprint area. This creates a 3-point contact between the FiberTape U-suture and the cow hitch knot on the area. We believe that this technique provides fast and reliable fixation due to its 3-point contact application and simplicity.

Current concepts in acromioclavicular joint (AC) instability - a proposed treatment algorithm for acute and chronic AC-joint surgery

BACKGROUND

There exists a vast number of surgical treatment options for acromioclavicular (AC) joint injuries, and the current literature has yet to determine an equivocally superior treatment. AC joint repair has a long history and dates back to the beginning of the twentieth century.

MAIN BODY

Since then, over 150 different techniques have been described, covering open and closed techniques. Low grade injuries such as Type I-II according to the modified Rockwood classification should be treated conservatively, while high-grade injuries (types IV-VI) may be indicated for operative treatment. However, controversy exists if operative treatment is superior to nonoperative treatment, especially in grade III injuries, as functional impairment due to scapular dyskinesia or chronic pain remains concerning following non-operative treatment. Patients with a stable AC joint without overriding of the clavicle and without significant scapular dysfunction (Type IIIA) may benefit from non-interventional approaches, in contrast to patients with overriding of the clavicle and therapy-resistant scapular dysfunction (Type IIIB). If these patients are considered non-responders to a conservative approach, an anatomic AC joint reconstruction using a hybrid technique should be considered. In chronic AC joint injuries, surgery is indicated after failed nonoperative treatment of 3 to 6 months. Anatomic AC joint reconstruction techniques along with biologic augmentation (e.g. Hybrid techniques, suture fixation) should be considered for chronic high-grade instabilities, accounting for the lack of intrinsic healing and scar-forming potential of the ligamentous tissue in the chronic setting. However, complication and clinical failure rates remain high, which may be a result of technical failures or persistent horizontal and rotational instability.

CONCLUSION

Future research should focus on addressing horizontal and rotational instability, to restore native physiological and biomechanical properties of the AC joint.

Limited Biomechanical Evidence Behind Single Row Versus Double Row Repair of Subscapularis Tears: A Systematic Review

Purpose

To systematically review the literature for studies investigating the biomechanical properties of constructs used to repair isolated subscapularis tears in time zero human cadaveric studies.

Methods

A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Three electronic databases were searched for studies that reported on the construct technique and biomechanical outcomes for the repair of isolated subscapularis tears in human cadaveric specimens. Ultimate load, gap formation, stiffness, and failure mode were documented. Methodological quality was assessed using the Quality Appraisal for Cadaveric Studies (QUACS) scale.

Results

Six articles qualified (104 shoulders [72 single-row, 26 double-row, 6 transosseous]; mean QUACS score 10.5 ± 1) and were analyzed. Studies varied in the number and type of anchors and construct technique (1-2 anchors single-row; 3-4 anchors double-row; bioabsorbable or titanium anchors) and suture(s) used (no. 2 FiberWire or FiberTape), subscapularis tear type (25%, 33%, 50%, or 100% tear), and whether a knotless or knotted fixation was used. In studies that created full-thickness, upper subscapularis tears (Fox-Romeo II/III or Lafosse II), no significant differences were seen in ultimate load, gap formation, and stiffness for knotted versus knotless single-row repair (2 studies) and single-row versus double-row repair (1 study). Double-row repair of complete subscapularis tears demonstrated higher ultimate load, stiffness, and lower gap formation in 1 study. Ultimate load differed between the studies and constructs (single-row: range, 244 N to 678 N; double-row: range 332 N to 508 N, transosseous: 453 N). Suture cutout was the most common mode of failure (59%).

Conclusion

Because of the limited number of studies and varying study designs in examining the biomechanical properties of repair constructs used for subscapularis tears, there is inconclusive evidence to determine which construct type is superior for repairing subscapularis tears.

Clinical Relevance

Results from biomechanical studies of clinically relevant subscapularis repair constructs are important to guide decision-making for choosing the optimal construct for patients with subscapularis tears.

Comparison of Knotless and Knotted Single-Anchor Repair for Ruptures of the Upper Subscapularis Tendon: Outcomes at 2-Year Follow-up

Background:

Both knotted and knotless single-anchor repair techniques are used to repair transmural ruptures of the upper subscapularis (SSC) tendon. However, it is still unclear which technique provides better clinical and radiological results.

Purpose/Hypothesis:

To compare the clinical and magnetic resonance imaging (MRI) outcomes of knotless and knotted single-anchor repair techniques in patients with a transmural rupture of the upper SSC tendon at 2-year follow-up. It was hypothesized that the 2 techniques would not differ significantly in outcomes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Forty patients with a transmural tear of the upper SSC tendon (grade 2 or 3 according to Fox and Romeo) were retrospectively enrolled. Depending on the repair technique, patients were assigned to either the knotless single-anchor or knotted single-anchor group. After a mean follow-up of 2.33 ± 0.43 years, patients were assessed by the ASES, WORC, OSS, CS, and SSV. A clinical examination that included the bear-hug, the lift-off, and the belly-press tests was performed, in which the force exerted by the subjects was measured. In addition, all patients underwent MRI of the affected shoulder to assess repair integrity, tendon width, fatty infiltration, signal-to-signal ratio of the upper and lower SSC muscle, and atrophy of the SSC muscle.

Results:

No significant difference was found between the 2 groups on any of the clinical scores [ASES (P = .272), WORC (P = .523), OSS (P = .401), CS (P = .328), SSV (P = .540)] or on the range-of-motion or force measurements. Apart from a higher signal-to-signal ratio of the lower SSC muscle in the knotless group (P = .017), no significant difference on imaging outcomes was found between the 2 groups.

Conclusion:

Both techniques can be used in surgical practice, as neither was found to be superior to the other in terms of clinical or imaging outcomes at 2-year follow-up.

Are Knotted or Knotless Techniques Better for Reconstruction of Full-Thickness Tears of the Superior Portion of the Subscapularis Tendon? A Study in Cadavers

BACKGROUND

Knotted and knotless single-anchor reconstruction techniques are frequently performed to reconstruct full-thickness tears of the upper portion of subscapularis tendon. However, it is unclear whether one technique is superior to the other.

QUESTIONS/PURPOSES

(1) When comparing knotless and knotted single-anchor reconstruction techniques in full-thickness tears of the upper subscapularis tendon, is there a difference in stiffness under cyclic load? (2) Are there differences in cyclic gapping between knotless and knotted reconstructions? (3) Are there differences in the maximal stiffness, yield load, and ultimate load to failure? (4) What are the modes of failure of knotless and knotted reconstruction techniques?

METHODS

Eight matched pairs of human cadaveric shoulders were dissected, and a full-thickness tear of the subscapularis tendon (Grade 3 according to the Fox and Romeo classification) was created. The cadavers all were male specimens, with a median (range) age of 69 years (61 to 75). Before biomechanical evaluation, the specimens were randomized into two equal reconstruction groups: knotless single anchor and knotted single anchor. All surgical procedures were performed by a single orthopaedic surgeon who subspecializes in sports orthopedics and shoulder surgery. With a customized set up that was integrated in a dynamic material testing machine, the humeri were consecutively loaded from 10 N to 60 N, from 10 N to 100 N, and from 10 N to 180 N for 50 cycles. Furthermore, the gapping behavior of the tear was analyzed using a video tracking system. Finally, the stiffness, gapping, maximal stiffness, yield loads, and maximum failure loads of both reconstruction groups were statistically analyzed. Failure was defined as retearing of the reconstructed gap threshold due to rupture of the tendon and/or failure of the knots or anchors. After biomechanical testing, bone quality was measured at the footprint of the subscapularis using microCT in all specimens. Bone quality was equal between both groups. To detect a minimum 0.15-mm difference in gap formation between the two repair techniques (with a 5% level of significance; α = 0.05), eight matched pairs (n = 16 in total) were calculated as necessary to achieve a power of at least 90%.

RESULTS

The first study question can be answered as follows: for stiffness under cyclic load, there were no differences with the numbers available between the knotted and knotless groups at load stages of 10 N to 60 N (32.7 ± 3.5 N/mm versus 34.2 ± 5.6 N/mm, mean difference 1.5 N/mm [95% CI -6.43 to 3.33]; p = 0.55), 10 N to 100 N (45.0 ± 4.8 N/mm versus 45.2 ± 6.0 N/mm, mean difference 0.2 N/mm [95% CI -5.74 to 6.04]; p = 0.95), and 10 N to 180 N (58.2 ± 10.6 N/mm versus 55.2 ± 4.7 N/mm, mean difference 3 N/mm [95% CI -5.84 to 11.79]; p = 0.48). In relation to the second research question, the following results emerged: For cyclic gapping, there were no differences between the knotted and knotless groups at any load levels. The present study was able to show the following with regard to the third research question: Between knotted and knotless repairs, there were no differences in maximal load stiffness (45.3 ± 8.6 N/mm versus 43.5 ± 10.2 N/mm, mean difference 1.8 [95% CI -11.78 to 8.23]; p = 0.71), yield load (425.1 ± 251.4 N versus 379.0 ± 169.4 N, mean difference 46.1 [95% CI -276.02 to 183.72]; p = 0.67), and failure load (521.1 ± 266.2 N versus 475.8 ± 183.3 N, mean difference 45.3 [95% CI -290.42 to 199.79]; p = 0.69). Regarding the fourth question concerning the failure modes, in the knotted repairs, the anchor tore from the bone in 2 of 8, the suture tore from the tendon in 6 of 8, and no suture slipped from the eyelet; in the knotless repairs, the anchor tore from the bone in 2 of 8, the suture tore from the tendon in 3 of 8, and the threads slipped from the eyelet in 3 of 8.

CONCLUSION

With the numbers available, we found no differences between single-anchor knotless and knotted reconstruction techniques used to repair full-thickness tears of the upper portion of subscapularis tendon.

CLINICAL RELEVANCE

The reconstruction techniques we analyzed showed no differences in terms of their primary stability and biomechanical properties at the time of initial repair and with the numbers available. In view of these experimental results, it would be useful to conduct a clinical study in the future to verify the translationality of the experimental data of the present study.

Literature Review of Subscapularis Tear, Associated injuries, and the Available Treatment Options

The population of Hawai'i is uniquely connected to the Ocean and to open water sports. Shoulder injuries, particularly those to the rotator cuff, are among the most common injuries sustained to athletes participating in ocean sports such as surfing, paddling, and swimming. In addition, rotator cuff injuries increase in prevalence with advanced age. As a consequence, the number of patients in Hawai'i who present with an injury to the subscapularis tendon will continue to rise. However, limited research has been done to delineate the involvement of subscapularis injuries in this population. This article covers the anatomy and function of the subscapularis, the epidemiology and classification of tears in this tendon, and the management of tears. The anatomy section will cover innervation, vascular supply and insertional anatomy of the subscapularis tendon. The function of the subscapularis in regards to both stability and motion of the glenohumeral joint will be examined. The focus of the article will then shift to the tears of the subscapularis, starting with an in depth look at the epidemiology and classification of these tears. The article will then cover the different imaging modalities and their utility in regards to subscapularis tears. Finally, the operative and non-operative management and indications for each modality will be discussed in detail.

Arthroscopic Single and Double Row Repair of Isolated and Combined Subscapularis Tears Result in Similar Improvements in Outcomes: A Systematic Review

PURPOSE

To systematically review the literature to (1) describe arthroscopic subscapularis repair constructs and outcomes in patients with isolated and combined subscapularis tears and (2) compare outcomes after single- and double-row subscapularis repair in both of these settings.

METHODS

A systematic review was performed using PRISMA guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for Level I-IV evidence studies that investigated outcomes after arthroscopic subscapularis repair for the treatment of isolated subscapularis tears or subscapularis tears combined with posterosuperior rotator cuff tears in adult human patients. Data recorded included study demographics, repair construct, shoulder-specific outcome measures, and subscapularis retears. Study methodological quality was analyzed using the MINORS score. Heterogeneity and low levels of evidence precluded meta-analysis.

RESULTS

The initial search yielded 811 articles (318 duplicates, 493 screened, 67 full-text review). Forty-three articles (2406 shoulders, 57% males, mean age range 42 to 67.5 years, mean MINORS score 13.4 ± 4.1) were included and analyzed. Articles reported on patients with isolated subscapularis tears (n = 15), combined tears (n = 17), or both (n = 11). The majority of subscapularis repairs used single-row constructs (89.4% of isolated tears, 88.9% of combined tears). All except for one study reporting on outcome measures found clinically significant improvements after subscapularis repair, and no clinically significant differences were detected in 5 studies comparing isolated to combined tears. Subscapularis retear rates ranged from 0% to 17% for isolated tears and 0% to 32% for combined subscapularis and posterosuperior rotator cuff tears. Outcomes and retear rates were similar in studies comparing single-row to double-row repair for isolated and combined subscapularis tears (P > .05 for all).

CONCLUSION

Arthroscopic subscapularis repair resulted in significant improvements across all outcome measures, regardless of whether tears were isolated or combined or if repairs were single or double row.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II-IV studies.

Arthroscopic Suture-Bridge Repair of the Subscapularis Tendon-"Inside and Outside the Box" With Preservation of the Comma Sign

The subscapularis muscle and its tendon are of major importance in the kinematics of the glenohumeral joint. Therefore, a diligent repair of subscapularis tears is essential. We describe our reliable standardized arthroscopic suture bridge technique to repair subscapularis tears under intra- and extraarticular visualization and with preservation of the "comma sign." This technique provides excellent exposure of the subscapularis tendon, allows its complete release in the subcoracoid space and ensures a safe and stable repair.

A "Comma Sign"-Directed Subscapularis Repair in Anterosuperior Rotator Cuff Tears Yields Biomechanical Advantages in a Cadaveric Model

BACKGROUND

Additional stabilization of the "comma sign" in anterosuperior rotator cuff repair has been proposed to provide biomechanical benefits regarding stability of the repair.

PURPOSE

This in vitro investigation aimed to investigate the influence of a comma sign-directed reconstruction technique for anterosuperior rotator cuff tears on the primary stability of the subscapularis tendon repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 18 fresh-frozen cadaveric shoulders were used in this study. Anterosuperior rotator cuff tears (complete full-thickness tear of the supraspinatus and subscapularis tendons) were created, and supraspinatus repair was performed with a standard suture bridge technique. The subscapularis was repaired with either a (1) single-row or (2) comma sign technique. A high-resolution 3D camera system was used to analyze 3-mm and 5-mm gap formation at the subscapularis tendon-bone interface upon incremental cyclic loading. Moreover, the ultimate failure load of the repair was recorded. A Mann-Whitney test was used to assess significant differences between the 2 groups.

RESULTS

The comma sign repair withstood significantly more loading cycles than the single-row repair until 3-mm and 5-mm gap formation occurred (P≤ .047). The ultimate failure load did not reveal any significant differences when the 2 techniques were compared (P = .596).

CONCLUSION

The results of this study show that additional stabilization of the comma sign enhanced the primary stability of subscapularis tendon repair in anterosuperior rotator cuff tears. Although this stabilization did not seem to influence the ultimate failure load, it effectively decreased the micromotion at the tendon-bone interface during cyclic loading.

CLINICAL RELEVANCE

The proposed technique for stabilization of the comma sign has shown superior biomechanical properties in comparison with a single-row repair and might thus improve tendon healing. Further clinical research will be necessary to determine its influence on the functional outcome.

Clinical Outcomes and Tendon Integrity in Patients With Chronic Retracted Subscapularis Tear After Arthroscopic Single-Row Oblique Mattress Suture Repair Technique

PURPOSE

To evaluate clinical outcomes and tendon integrity in patients with chronic retracted subscapularis tears using an arthroscopic single-row oblique mattress suture repair technique.

METHODS

Patients with full-thickness subscapularis tears retracted to the glenoid level and with at least 2 years of follow-up were included. Tendon retraction level was measured on preoperative axial magnetic resonance images and confirmed during arthroscopic surgery. The subscapularis tendon was repaired arthroscopically using the single-row oblique mattress suture technique on the medial margin of the lesser tuberosity. Two double-loaded suture anchors were used to obtain firm fixation between the tendon and the footprint. Clinical outcomes were assessed for all patients preoperatively and postoperatively using active range of motion, a visual analog scale score for pain, and American Shoulder and Elbow Surgeons and Constant scores. To evaluate structural integrity of the repaired tendon, all patients underwent magnetic resonance imaging at 6 months and ultrasonography at 1 year after surgery.

RESULTS

The shoulder function of the 33 patients analyzed was improved significantly after a mean follow-up period of 26.3 ± 3.5 months compared with preoperative values (American Shoulder and Elbow Surgeons score of 52.0 ± 7.9 preoperatively vs 79.6 ± 7.0 at last follow-up, P < .001, and Constant score of 43.0 ± 13.4 preoperatively vs 76.7 ± 9.2 at last follow-up, P < .001). Postoperative active range of motion improved significantly in forward flexion, external rotation, and internal rotation (P < .001). The mean visual analog scale pain score decreased by 3.42 (5.2 ± 1.6 preoperatively vs 1.9 ± 1.4 at last follow-up, P < .001). In 4 patients (12.1%), subscapularis retears were confirmed on postoperative magnetic resonance imaging.

CONCLUSIONS

Despite significant retraction, arthroscopic repair using a single-row oblique mattress suture technique in patients who had chronic subscapularis tears with retraction to the glenoid level yielded satisfactory clinical outcomes and reliable tendon healing.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Arthroscopic Repair of the Isolated Subscapularis Full-Thickness Tear: Single- Versus Double-Row Suture-Bridge Technique

BACKGROUND

No clinical comparative study has addressed isolated subscapularis tears after arthroscopic repair with either single-row or double-row suture-bridge technique.

PURPOSE/HYPOTHESIS

The purpose of this study is to compare clinical outcomes and structural integrity after arthroscopic repair of an isolated subscapularis full-thickness tear with either the single-row technique or the double-row suture-bridge technique. The authors hypothesized that there would be no significant differences in clinical outcomes and structural integrity between approaches.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study included 56 patients who underwent arthroscopic repair of an isolated subscapularis full-thickness tear with grade II or less fatty infiltration in the subscapularis muscle with either a single-row technique (n = 31) or a double-row suture-bridge technique (n = 25). Functional outcomes were assessed with the visual analog scale (VAS) for pain, Subjective Shoulder Value (SSV), American Shoulder and Elbow Surgeons (ASES) score, the University of California, Los Angeles (UCLA) shoulder score, and active range of motion. Magnetic resonance arthrography (MRA) or computed tomographic arthrography (CTA) was performed 6 months after surgery to assess the structural integrity of the repaired tendon.

RESULTS

At the 2-year follow-up, all scoring parameters applied (VAS, SSV, ASES, and UCLA), subscapularis strength, and active range of motion improved significantly in both groups as compared with preoperative values ( P < .001). However, there were no significant differences between groups in any of these clinical outcome measurements (VAS, 1.2 vs 1.1; SSV, 91.3 vs 91.8; ASES, 91.0 vs 91.4; UCLA, 31.9 vs 32.1). On follow-up MRA or CTA, the overall retear rate did not differ significantly between the single-row group (13%, 4 of 31) and the double-row group (12%, 3 of 25).

CONCLUSION

Arthroscopic single-row repair and double-row suture-bridge repair of isolated full-thickness subscapularis tears both yielded satisfactory clinical outcomes and structural integrity with no significant differences among patients with good muscle quality.

Double-Row Arthroscopic Subscapularis Repair: A Surgical Technique

The subscapularis is the strongest rotator cuff muscle in the shoulder. Until recently, most surgical repairs were performed through an open approach. Furthermore, the reporting of arthroscopic repair techniques and outcomes is fairly limited. This is likely due to the difficulty involved in all-arthroscopic repairs and the relative rarity of this injury compared with injuries of the other rotator cuff tendons. Arthroscopic subscapularis repair can be challenging, even for an expert surgeon, and attempting a double-row repair adds further complexity. Given these issues, this article provides techniques to allow for successful arthroscopic double-row subscapularis repair and avoid potential complications. The key features of an arthroscopic double-row repair include portal placement, surgical technique, and tips to avoid potential pitfalls, all of which are discussed.

[Arthroscopic double-row reconstruction of high-grade subscapularis tendon tears]

OBJECTIVE

Reconstruction of tendon integrity to maintain glenohumeral joint centration and hence to restore shoulder functional range of motion and to reduce pain.

INDICATIONS

Isolated or combined full-thickness subscapularis tendon tears (≥upper two-thirds of the tendon) without both substantial soft tissue degeneration and cranialization of the humeral head.

CONTRAINDICATIONS

Chronic tears of the subscapularis tendon with higher grade muscle atrophy, fatty infiltration, and static decentration of the humeral head.

SURGICAL TECHNIQUE

After arthroscopic three-sided subscapularis tendon release, two double-loaded suture anchors are placed medially to the humeral footprint. Next to the suture passage, the suture limbs are tied and secured laterally with up to two knotless anchors creating a transosseous-equivalent repair.

POSTOPERATIVE MANAGEMENT

The affected arm is placed in a shoulder brace with 20° of abduction and slight internal rotation for 6 weeks postoperatively. Rehabilitation protocol including progressive physical therapy from a maximum protection phase to a minimum protection phase is required. Overhead activities are permitted after 6 months.

RESULTS

While previous studies have demonstrated superior biomechanical properties and clinical results after double-row compared to single-row and transosseous fixation techniques, further mid- to long-term clinical investigations are needed to confirm these findings.

Arthroscopic Repair of Massive Subscapularis and Supraspinatus Tear by Double-Row Knotless Technique

Subscapularis is the most powerful muscle in the rotator cuff. A steep learning curve and constrained space anteriorly make the repair difficult. In massive tears of the rotator cuff, repair of the subscapularis initially makes the massive supraspinatus tear repairable. We present our technique to repair subscapularis and supraspinatus tear by double-row anchors in a knotless and tension-free manner. This technique can be done in partial or full-thickness tears of the upper subscapularis.

Load response and gap formation in a single-row cruciate suture rotator cuff repair

BACKGROUND

Double-row rotator cuff tendon repair techniques may provide superior contact area and strength compared with single-row repairs, but are associated with higher material expenses and prolonged operating time. The purpose of this study was to evaluate gap formation, ultimate tensile strength and stiffness of a single-row cruciate suture rotator cuff repair construct, and to compare these results with those of the Mason-Allen and SutureBridge repair constructs.

METHODS

Infraspinatus tendons from 24 spring lamb shoulders were harvested and allocated to cruciate suture, Mason-Allen and SutureBridge repair groups. Specimens were loaded cyclically between 10 and 62 N for 200 cycles, and gap formation simultaneously measured using a high-speed digital camera. Specimens were then loaded in uniaxial tension to failure, and construct stiffness and repair strength were evaluated.

RESULTS

Gap formation in the cruciate suture repair was significantly lower than that of the Mason-Allen repair (mean difference = 0.6 mm, P = 0.009) and no different from that of the SutureBridge repair (P > 0.05). Both the cruciate suture repair (mean difference = 15.7 N/mm, P = 0.002) and SutureBridge repair (mean difference = 15.8 N/mm, P = 0.034) were significantly stiffer than that of the Mason-Allen repair; however, no significant differences in ultimate tensile strength between repair groups were discerned (P > 0.05).

CONCLUSION

The cruciate suture repair construct, which may represent a simple and cost-effective alternative to double-row and double-row equivalent rotator cuff repairs, has comparable biomechanical strength and integrity with that of the SutureBridge repair, and may result in improved construct longevity and tendon healing compared with the Mason-Allen repair.

Reconstruction of 25 and 50 % subscapularis tears: a single anchor with a double-mattress suture is sufficient for the reconstruction

PURPOSE

Evaluation of the biomechanical performance of repairs of 25 % (Fox/Romeo II) and 50 % (Fox/Romeo III) full-thickness subscapularis tears using a single-suture anchor.

METHODS

Six pairs of human cadaver specimens were used for the testing. Artificial subscapularis tears were created in order to simulate a 25 % (6) and a 50 % (6) full-thickness tear. The reconstructions were made with a double-loaded suture anchor (5.5-mm Bio-Corkscrew with two No. 2 Fiberwire) creating a double-mattress suture repair. Reconstructions were cyclically loaded from 10 to 60 N. The load was increased stepwise up to 100 and 180 N. Cyclic displacement (means + standard dev.) as well as load-to-failure was determined, and mode of failure was recorded.

RESULTS

In the reconstructed shoulders at 60 N, a mean cyclic displacement of 3.2 ± 0.7 mm was found in the 25 % tear, 2.6 ± 0.6 mm in the 50 % tear. At 100 N, 5.1 ± 1.2 mm was seen in the 25 % tear and 4.3 ± 0.3 mm in the 50 % tear. At highest load of 180 N, 7.6 ± 2.2 mm was recorded in the 25 % tear, 6.5 ± 0.8 mm was found in the 50 % tear. Ultimate failure load was 486 ± 167 N in the 25 % tear and 455 ± 213 N in the 50 % tear. Statistically significant differences between the tested repairs were seen neither in cyclic displacement nor in ultimate failure loads (p > 0.05). Mode of failure revealed bone fractures and anchor pull-out as major cause in the 25 % group, whereas failure of the suture-tendon interface was the major cause of failure in the 50 % group.

CONCLUSIONS

Subscapularis repair using a single double-loaded suture anchor revealed similar biomechanical performance in 25 % compared to 50 % full-thickness subscapularis tears. With increased tear size, however, an optimized suture-tendon interface seems to become more relevant in order to decrease failure rate of the repair.

CLINICAL RELEVANCE

A single double-loaded suture anchor provides sufficient biomechanical strength even in Fox/Romeo grade III tears of the subscapularis tendon. However, a modified suture configuration is recommended, especially in grade III tears as the suture-tendon interface is the weakest point of the construct.

Functional and structural comparisons of the arthroscopic knotless double-row suture bridge and single-row repair for anterosuperior rotator cuff tears

BACKGROUND

We compared the outcomes of knotless double-row suture bridge and single-row repairs in patients undergoing arthroscopic repair for anterosuperior rotator cuff tears.

METHODS

We included 61 full-thickness anterosuperior rotator cuff tears treated by arthroscopic repair, namely, single-row repair (group 1: 25 shoulders; mean patient age, 64 years) and the knotless double-row suture bridge repair (group 2: 36 shoulders; mean patient age, 62 years). Preoperative and postoperative magnetic resonance imaging was performed for all shoulders. Clinical outcomes were evaluated for mean follow-up periods of 81 months (range, 72-96 months) in group 1 and 34 months (range, 24-42 months) in group 2, using the University of California, Los Angeles and Japanese Orthopaedic Association assessments.

RESULTS

At the final follow-up, both groups showed improvement in the average University of California, Los Angeles and Japanese Orthopaedic Association scores and range of motion, although no intergroup differences were observed. Both groups showed improved abduction strength, and the average score was higher in group 2 (P = .0112). The lift-off and belly-press test results were improved in both groups. Postoperatively, the incidence of positive lift-off tests tended to be lower (P = .075) and that of positive belly-press tests was lower in group 2, P = .049). The repair failure rate tended to be lower in group 2 (14% [5 of 36]) than in group 1 (32% [8 of 25]; P = .0839).

CONCLUSIONS

Arthroscopic knotless double-row suture bridge repair of anterosuperior rotator cuff tears yielded functional outcomes equivalent to those of single-row repair and may be useful for improving subscapularis function, abduction strength, and tendon healing.

Knotless Arthroscopic Repair of Subscapularis Tendon Tears Using Looped Suture

Subscapularis tendon tears present a technical challenge because both diagnosis and arthroscopic treatment can be difficult. One difficulty is the limited visualization and working space of the anterior shoulder. Although most tears of the subscapularis are partial- or full-thickness tears of the upper third of the tendon, occasionally, larger or more retracted tears are encountered. Various techniques have been developed to treat a wide variety of tear patterns. We present a simple technique using a looped suture that remains easy to use in the limited working space of the anterior shoulder; can be easily modified to accommodate a broad spectrum of subscapularis pathology, from partial to full and retracted tears; and uses familiar viewing and working portals. This technique creates a single-row, knotless repair. Traction on the superior suture improves visualization and ease of passing more inferior sutures. Risks include unintentional over-tensioning of the repair and medialization of the femoral footprint, which can be avoided with appropriate exposure and arm positioning during repair. Postoperative care includes restriction of external rotation for 3 to 6 weeks and strengthening at 3 months.

Subscapularis Tendon Repair Using Suture Bridge Technique

The subscapularis tendon plays an essential role in shoulder function. Although subscapularis tendon tears are less common than other rotator cuff tears, tears of the subscapularis tendon have increasingly been recognized with the advent of magnetic resonance imaging and arthroscopy. A suture bridge technique for the treatment of posterosuperior rotator cuff tears has provided the opportunity to improve the pressurized contact area and mean footprint pressure. However, suture bridge fixation of subscapularis tendon tears appears to be technically challenging. We describe an arthroscopic surgical technique for suture bridge repair of subscapularis tendon tears that obtains ideal cuff integrity and footprint restoration. Surgery using such a suture bridge technique is indicated for large tears, such as tears involving the entire first facet or more, tears with a disrupted lateral sling, and combined medium to large supraspinatus/infraspinatus tears.

Arthroscopic repair of traumatic isolated subscapularis tendon lesions (Lafosse Type III or IV): a prospective magnetic resonance imaging-controlled case series with 1 year of follow-up

PURPOSE

The purpose of this study was to prospectively assess the efficacy of arthroscopic repair of isolated high-grade subscapularis (SSC) tendon lesions by means of clinical follow-up combined with magnetic resonance imaging investigations.

METHODS

Between January 2008 and September 2010, 11 patients (9 men and 2 women; mean age, 45 ± 10 years) with Lafosse type III or IV traumatic isolated SSC tendon lesions underwent arthroscopic repair including tenodesis of the long head of the biceps tendon. All patients were preoperatively assessed by clinical examination (Constant-Murley score [CMS]) and contrast-enhanced magnetic resonance arthrography. At 1 year of follow-up, specific clinical SSC tests, the CMS, and the loss of external rotation were evaluated. A native magnetic resonance investigation was performed to assess the structural integrity of the repair. The SSC muscle was compared with its preoperative condition regarding fatty infiltration and size (cross-sectional area). Patient satisfaction was graded from 1 (poor) to 4 (excellent).

RESULTS

The mean time interval from trauma to surgery was 3.7 months. A concomitant lesion of the biceps tendon was observed in 10 patients (91%). The mean CMS improved from 44 to 89 points (P < .001). The functional tests showed a significant increase in strength (P < .05) (belly-press test, 4.8 v 2.9; lift-off test, 4.8 v 2.9). The mean loss of external rotation at 0° of abduction was 10° compared with the contralateral side (P < .05). Patient satisfaction was high. Magnetic resonance imaging evaluation showed complete structural integrity of the tendon repair in all studies. The SSC showed a significant decrease in fatty infiltration and increase in the cross-sectional area.

CONCLUSIONS

Arthroscopic repair of higher-grade isolated SSC lesions provides reliable tendon healing accompanied by excellent functional results 1 year after surgery.

LEVEL OF EVIDENCE

Level IV, prospective therapeutic case series.

[The isolated subscapularis tendon tear: arthroscopic and open repair]

OBJECTIVE

Arthroscopic or open reconstruction of isolated subscapularis tendon tears with the use of suture anchors to restore the glenohumeral function and joint biomechanics.

INDICATIONS

Traumatic full-thickness tears, chronic tears with a functional deficit or decentration of the humerus head, anterosuperior rotator cuff insufficiency, symptomatic reruptures after prior arthroscopic or open surgical procedures.

CONTRAINDICATIONS

Frozen shoulder, atrophy > grade II (Thomazeau) or fatty infiltration > grade III (Goutallier/Fox) of the muscle, high-grade omarthrosis.

SURGICAL TECHNIQUE

Diagnostic arthroscopy and careful tendon release. If the inferior edge of the rupture is reliable visible and the tendon-mobilisation works proper, the repair is performed arthroscopically. The footprint is decorticated lightly and 1-4 suture anchors (depending on the lesion-size) are placed from inferior to superior. Knots are tied starting from caudal in a modified Mason-Allen technique (alternative: single or double mattress stitches) with a slipknot and three half hitches in opposite directions. In case of larger tears, a double-row technique for better reconstruction of the trapezoidal footprint is performed. For open reconstruction, a deltopectoral approach is used to reattache the tendon in an analogous fashion.

RESULTS

Arthroscopic or open repair of isolated subscapularis tendon tears (Fox type II-IV) was performed in 35 patients. The Constant score increased significantly after 36 m, with no difference between these two groups. The majority of subscapularis tests were postoperatively negative, 6% in both groups showed a rerupture. A symptomatic period of > 6 m prior to the operation and a high grade atrophy and fatty infiltration of the muscle was correlated with poorer results.

Is arthroscopic coracoplasty necessary in subcoracoid impingement syndrome?

PURPOSE

The purpose of this study was to analyze the outcomes of arthroscopic coracoplasty in the treatment of subcoracoid impingement syndrome.

METHODS

We compared 23 shoulders that underwent arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome with 28 shoulders that did not undergo arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome, which comprised the control group. All the shoulders had subcoracoid and subacromial impingement syndrome with or without rotator cuff tear. Subcoracoid impingement was defined as a coracohumeral distance of less than 6 mm on the preoperative magnetic resonance image with anterior shoulder pain or tenderness. The 2 groups were further divided into several subgroups according to the size of concomitant rotator cuff tear, and a comparative analysis of functional outcomes after surgery among the subgroups was performed.

RESULTS

In the 2 groups, the overall functional outcomes improved after surgery. The study group showed a significant increase in internal rotation compared with that in the control group (P = .001) at the last follow-up. The large to massive rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P = .017). On the other hand, no significant difference was seen in the subgroups with small to medium rotator cuff tears including isolated subscapularis tears. The no rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P = .046).

CONCLUSIONS

Arthroscopic coracoplasty for subcoracoid impingement syndrome can provide a satisfactory outcome. In particular, a significant increase in internal rotation of the treated group was achieved after surgery in comparison with the untreated group, especially in the large to massive rotator cuff tear subgroup and in the no rotator cuff tear subgroup.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Double row repair: is it worth the hassle?

In the operative management of rotator cuff disease, comparable functional results have been reported after open or mini-open repair and arthroscopic fixation. Surgical repair aims to re-establish an anatomical configuration of the tendon-bone construct for restoring its mechanical performance. Single row repair is the most commonly used technique, but recently some authors have proposed to re-establish the rotator cuff footprint with 2 rows of suture anchors ("double row" repair). In regard to imaging assessment, at time zero double row repair results being more anatomic and allows for structurally sound restoration of the rotator cuff footprint. However, this does not seem to translate into superior clinical outcomes for the double row repair when evaluating all different sizes of rotator cuff tears as a whole. The scientific basis for recommending single or double row repair as preferred treatment for patients with rotator cuff tear is questionable, as minimal differences have been measured on clinical and functional rating scales.

Double-row fixation of upper subscapularis tears with a single suture anchor

The recognition of and discussion of operative techniques for subscapularis tendon tears have lagged behind those for the posterosuperior rotator cuff. The advancement of shoulder arthroscopy has provided the opportunity to see the articular side of the rotator cuff and has led to increased recognition of subscapularis tears. Double-row fixation of the posterosuperior rotator cuff has become popular because of improved biomechanical strength, footprint restoration, and tendon healing compared with single-row fixation. Double-row fixation of the subscapularis, however, has been challenging because of the small anterior space overlying the subscapularis. Whereas the subacromial space allows freedom of movement, the limited subcoracoid space makes visualization, instrument manipulation, and knot tying more difficult. We describe a new technique for double-row fixation of the upper subscapularis footprint using a knotless technique without an additional anchor, which eases some of the aforementioned difficulties. The technique is indicated for partial- or full-thickness tears of the upper 50% of the subscapularis tendon and therefore applies to the majority of tears involving the subscapularis tendon.

Suture-bridge subscapularis tendon repair technique using low anterior portals

A suture-bridge technique has been introduced to facilitate fixation procedures and to achieve increased holding strength in posterosuperior rotator cuff. Based on biomechanical studies, this technique has been suggested as an effective method that could optimize rotator cuff tendon-footprint contact area and mean pressure, as well as holding strength. In this technique, the suture-bridge creation is adapted for arthroscopic subscapularis repair to attain the ideal cuff integrity and footprint restoration. To obtain enough working portals and space, two accessory portals were made on the anterior aspect of the shoulder and use an elevator to retract the conjoined tendons and deltoid muscle. This technique could be useful for the repair of subscapularis tears, which are not easily approached using other arthroscopic techniques. From a biomechanical point of view, the subscapularis tendon could be restored more ideally using the suture-bridge technique.