A watertight construct in arthroscopic rotator cuff repair

All-Arthroscopic Supraspinatus and Infraspinatus Muscle Advancement Leads to High Healing Rate and Excellent Outcomes in Patients With Massive, Retracted Rotator Cuff Tears, Even in Patients With Pseudoparalysis

PURPOSE

To evaluate the clinical and radiographic outcomes of an all-arthroscopic rotator cuff repair technique involving muscle advancement and double-layer lasso loop (DLLL) repair for massive, retracted posterosuperior cuff tears.

METHODS

This was a retrospective case series of patients with massive, retracted posterosuperior cuff tears who underwent the all-arthroscopic muscle advancement technique from March 2017 to September 2021, with a minimum follow-up of 12 months. Key steps included suprascapular nerve release, advancement of the supraspinatus and infraspinatus muscles, and DLLL repair. Preoperative and postoperative visual analog scale score for pain, American Shoulder and Elbow Surgeons (ASES) shoulder score, Constant score, University of California, Los Angeles (UCLA) shoulder score, active range of motion, and strength were compared. Preoperative and postoperative structural radiologic characteristics were analyzed.

RESULTS

We evaluated 43 shoulders in 38 patients with a mean follow-up period of 18.8 months (range, 12-55 months). Of the 43 shoulders, 4 showed repair failure (9.3% retear rate). Visual analog scale, ASES, Constant, and UCLA scores significantly improved (P < .001) in patients who showed healing on postoperative magnetic resonance imaging (n = 39). ASES, Constant, and UCLA scores were significantly better in the healed group, with 100% exceeding the minimal clinically important difference for the ASES score and UCLA score and 84.2%, for Constant score. A lower proportion of patients in the retear group achieved the minimal clinically important difference. Active range of motion in all planes significantly improved for patients who had healed repairs (P < .001). Relative abduction strength, supraspinatus strength, and infraspinatus strength were at least 90% of those on the contralateral side. The recovery rate of pseudoparalysis (7 patients) was 100%.

CONCLUSIONS

All-arthroscopic muscle advancement, coupled with DLLL repair, leads to a high healing rate with excellent clinical outcomes and recovery of strength to at least 90%, even in patients with pseudoparalysis.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

3-in-1 Hybrid Suture Bridge Technique in Posterosuperior Rotator Cuff Tear

Our technique repaired the posterosuperior rotator cuff tear in the full-thickness type. The key successful of the arthroscopic full-thickness rotator cuff repair has several suture techniques. First, it will distribute a tensile force throughout the entire tendon. Second, it will improve tendon healing by getting it closer to the medial anatomical footprint. Third, the suture bridge compression technique has been used to compress all layers of the repaired tendon against the bone with the total contact area. Fourth, it reduces the risk of cut through the rotator cuff and the rate of rotator cuff retear with a tension free repair. We used three suture limbs in one hole to reduce rotator cuff damage and the rate of retear and also only tie three medial row knots. The reasons are to compress anatomically the medial footprint. The configuration suture pattern consists of suture bridges that distribute pressure-tension over a larger contact surface area on the tendon-bone interface, allowing for robust tendon-bone stabilization, better tendon-bone healing, and less retear after repair.

Transosseous-Equivalent/Suture Bridge Arthroscopic Rotator Cuff Repair in Combination With Late Postoperative Mobilization Yield Optimal Outcomes and Retear Rate: A Network Meta-analysis of Randomized Controlled Trials

PURPOSE

The purpose of this study was to perform a network meta-analysis of the randomized controlled trials (RCTs) in the literature in order to assess the evidence defining the optimal combination of surgical technique single-row repair (SRR), double-row repair (DRR), or transosseous-equivalent/suture bridge (TOE/SB) arthroscopic rotator cuff repair (ARCR) and postoperative rehabilitation (early or late) protocol for ARCR.

METHODS

The literature search was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized SSR-early trials (RCTs) comparing SRR vs DRR vs TOE/SB ARCR techniques were included, as well as early vs late postoperative range of motion. Clinical outcomes were compared using a frequentist approach to network meta-analysis, with statistical analysis performed using R. The treatment options were ranked using the P-score.

RESULTS

Twenty-eight studies comprising 2,181 total shoulders met the inclusion criteria. TOE/SB-late (odds ratio [OR], 0.19; 95% confidence interval [CI], 0.08-0.46) and DRR-late (OR, 0.25; 95% CI, 0.12-0.52) were found to significantly reduce the rate of retear, with TOE/SB-late resulting in the highest P-score for the American Shoulder and Elbow Surgeons (P-score: 0.7911) score and retear rate (P-score: 0.8725). DRR-early did not result in any significant improvements over the SRR-early group, except in internal rotation. There was no significant difference in forward flexion between groups, with almost equivalent P-scores. Furthermore, TOE/SB-early and TOE/SB-late trended toward worsening external rotation compared with the control.

CONCLUSIONS

The current study suggests that rotator cuff repair using the TOE/SB technique and late postoperative mobilization yields the highest functional outcomes and lowest retear rate in the arthroscopic management of symptomatic rotator cuff tears.

LEVEL OF EVIDENCE

Level I, meta-analysis of Level I studies.

Are Suture Tape Knots as Secure as Standard Suture? A Biomechanical Study

Background

Few studies have investigated the biomechanical performance of flat-braided suture tapes versus round-braided sutures after being knotted.

Purpose

To compare the loop security and knot strength of a standard round-braided suture with 3 commercially available flat-braided suture tapes using 2 types of arthroscopic knots.

Study Design

Controlled laboratory study.

Methods

One standard suture (SS) and 3 suture tapes (T1, T2, and T3) were tied with the surgeon's knot (SK) and the Tennessee slider (TS), 25 times each, by a single surgeon. Each combination of knots and sutures underwent a preload, cyclic loading, and load to failure. Outcomes were loop security (defined by loop stretch after a 5-N preload), load at clinical failure (3 mm of displacement), and load at ultimate failure (suture rupture or knot slippage). Two-way analysis of variance was used for analysis.

Results

Overall, the SK group had greater overall loop security than that of the TS group (0.4 ± 0.3 vs 0.5 ± 0.3 mm of stretch, respectively; P = .020). The clinical failure load varied by suture type (P < .001) but not knot type (P = .106). For both knot types, the SS had the lowest mean ± SD clinical failure load (SK, 171 ± 49 N; TS, 176 ± 37 N), which was significantly less than that of T2 (247 ± 85 N; P < .001) and T3 (251 ± 96 N; P < .001) for the SK type and T2 (231 ± 67 N; P = .023) for the TS type. T2 sutures had the greatest ultimate failure load for both knot types (SK, 418 ± 45 N; TS, 461 ± 57 N), which was significantly greater than SS, T1, and T3 (P < .001 for all). The TS knot had greater overall ultimate failure load than the SK (375 ± 64 vs 350 ± 66 N; P < .001).

Conclusion

Not all suture tape knots had the same biomechanical properties, although knot security and strength appeared to be adequate for all suture tapes as well as for SS. There was no evidence that suture tape knots are lower profile than SS knots.

Clinical Relevance

Surgeons should not use suture tape based only on the assumption that it has superior biomechanical properties to a standard round-braided suture.

Repair Integrity and Functional Outcomes Between Knot-Tying and Knotless Suture-Bridge Arthroscopic Rotator Cuff Repair: A Prospective Randomized Clinical Trial

Background:

Knot-tying suture-bridge (SB) rotator cuff repair may compromise the vascularity of the repaired tendon, causing tendon strangulation and medial repair failure. The knotless SB repair technique has been proposed to overcome this possibility and decrease retear rates.

Purpose:

To compare clinical and structural outcomes and retear patterns between the knot-tying and knotless SB techniques. We hypothesized that the knotless technique would result in lower retear rates owing to the preservation of intratendinous vascularity.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 104 patients with full-thickness rotator cuff tears were randomly and prospectively allocated to undergo knot-tying (group 1) or knotless (group 2) SB repair. Clinical outcome measures included range of motion, the visual analog scale (VAS) for pain, and the Constant score for function. Repair integrity was evaluated on magnetic resonance imaging scans using the Sugaya classification. Retears were also classified according to their pattern as type 1 (lateral) or type 2 (medial).

Results:

Overall, 88 patients (group 1: n = 42 [mean ± SD age, 54.3 ± 9.8 years]; group 2: n = 46 [mean ± SD age, 55.8 ± 8.2 years]) were included in the final analysis. The mean ± SD follow-up period was 25.4 ± 8.3 and 23.3 ± 7.2 months for groups 1 and 2, respectively. From preoperatively to postoperatively, the mean VAS pain score improved significantly in both groups (group 1: from 7.4 ± 1.7 to 1.0 ± 1.7; group 2: from 7.1 ± 1.9 to 1.3 ± 2.0; P < .0001 for both), as did the mean ± SD Constant score (group 1: from 51.7 ± 13.4 to 86.0 ± 11.5; group 2: from 49.4 ± 18.4 to 87.2 ± 14.8; P < .0001 for both). There was no significant difference between the groups for the postoperative VAS or Constant score. The retear rate was not significantly different between the groups (19.0% [8/42] in group 1 and 28.3% [13/46] in group 2; P > .05). There was a significant difference in the type 2 failure rate (75.0% [6/8] in group 1 and 23.1% [3/13] in group 2; P = .03).

Conclusion:

Both techniques showed excellent improvement and comparable clinical outcomes, and there was no significant difference in retear rates. Consistent with previously published data, the type 2 failure rate was significantly higher with the knot-tying technique.

Registration:

NCT03982108 (ClinicalTrials.gov identifier).

Biomechanical comparison between single-row with triple-loaded suture anchor and suture-bridge double-row rotator cuff repair

BACKGROUND

Numerous biomechanical and clinical studies comparing different techniques for rotator cuff repair have been reported, yet universal consensus regarding the superior technique has not achieved. A medially-based single-row with triple-loaded suture anchor (also referred to as the Southern California Orthopedic Institute [SCOI] row) and a suture-bridge double-row (SB-DR) with Push-Locks have been shown to result in comparable improvement in treating rotator cuff tear, yet the biomechanical difference is unknown. The purpose of the current study was to determine whether a SCOI row repair had comparable initial biomechanical properties to a SB-DR repair.

METHODS

Six matched pairs of fresh-frozen cadaveric shoulders with full-thickness supraspinatus tendon tears we created were included. Two different repairs were performed for each pair (SCOI row and SB-DR methods). Specimens were mounted on a material testing machine to undergo cyclic loading, which was cycled from 10 to 100 N at 1 Hz for 500 cycles. Construct gap formation was recorded at an interval of 50 cycles. Samples were then loaded to failure and modes of failure were recorded. Repeated-measures analysis of variance and pair-t test were used for statistical analyses.

RESULTS

The construct gap formation did not differ between SCOI row and SB-DR repairs (P = 0.056). The last gap displacement was 1.93 ± 0.37 mm for SCOI row repair, and 1.49 ± 0.55 mm for SB-DR repair. The tensile load for 5 mm of elongation and ultimate failure were higher for SCOI row repair compared to SB-DR repair (P = 0.011 and 0.028, respectively). The ultimate failure load was 326.34 ± 11.52 N in the SCOI row group, and 299.82 ± 27.27 N in the SB-DR group. Rotator cuff repair with the SCOI row method failed primarily at the suture- tendon interface, whereas pullout of the lateral row anchors was the primary mechanism of failure for repair with the SB-DR method.

CONCLUSION

Rotator cuff repair with the SCOI row method has superior biomechanical properties when compared with the SB-DR method. Therefore, SCOI row repair using a medially-based single-row technique with triple-loaded suture anchor is recommended to improve the initial strength in treating full-thickness rotator cuff tears.

TGF-β1-containing exosomes derived from bone marrow mesenchymal stem cells promote proliferation, migration and fibrotic activity in rotator cuff tenocytes

Objective

This study aimed to investigate effects of TGF-β1-containing exosomes derived from bone marrow mesenchymal stem cells (BMSC) on cell function of rotator cuff tenocytes and its implication to rotator cuff tear.

Methods

The primary BMSC and rotator cuff tenocytes were extracted and cultured. Identification of BMSC were performed by observing cell morphology and measurement of surface biomarkers by flow cytometry. BMSC-derived exosomes were extracted and identified by using electron microscopy, nanoparticle-tracking analysis (NTA) and western blotting. Cell proliferation and cell cycle were measured by CCK-8 assay and flow cytometry assay, respectively. Transwell assay was used for detection of tenocytes migration. The fibrotic activity of tenocytes was determined via qPCR and western blotting assays.

Results

BMSC and BMSC-derived exosomes were successfully extracted. Treatment of BMSC-derived exosomes or TGF-β1 promoted cell proliferation, migration and increased cell ratio of (S + G2/M) phases in tenocytes, as well as enhanced the expression levels of fibrotic activity associated proteins. However, inhibition of TGF-β1 by transfection of sh-TGF-β1 or treatment of TGFβR I/II inhibitor partially reversed the impact of BMSC-derived exosomes on tenocytes function.

Conclusion

Taken together, TGF-β1-containing exosomes derived from BMSC promoted proliferation, migration and fibrotic activity in rotator cuff tenocytes, providing a new direction for treatment of rotator cuff tendon healing.

A 3-Dimensional Bioprinted Scaffold With Human Umbilical Cord Blood-Mesenchymal Stem Cells Improves Regeneration of Chronic Full-Thickness Rotator Cuff Tear in a Rabbit Model

BACKGROUND

Chronic full-thickness rotator cuff tears (FTRCTs) represent a major clinical concern because they show highly compromised healing capacity.

PURPOSE

To evaluate the efficacy of using a 3-dimensional (3D) bioprinted scaffold with human umbilical cord blood (hUCB)-mesenchymal stem cells (MSCs) for regeneration of chronic FTRCTs in a rabbit model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 32 rabbits were randomly assigned to 4 treatment groups (n = 8 per group) at 6 weeks after a 5-mm FTRCT was created on the supraspinatus tendon. Group 1 (G1-SAL) was transplanted with normal saline. Group 2 (G2-MSC) was transplanted with hUCB-MSCs (0.2 mL, 1 × 10⁶) into FTRCTs. Group 3 (G3-3D) was transplanted with a 3D bioprinted construct without MSCs, and group 4 (G4-3D+MSC) was transplanted with a 3D bioprinted construct containing hUCB-MSCs (0.2 mL, 1 × 10⁶ cells) into FTRCTs. All 32 rabbits were euthanized at 4 weeks after treatment. Examination of gross morphologic changes and histologic results was performed on all rabbits after sacrifice. Motion analysis was also performed before and after treatment.

RESULTS

In G4-3D+MSC, newly regenerated collagen type 1 fibers, walking distance, fast walking time, and mean walking speed were greater than those in G2-MSC based on histochemical and motion analyses. In addition, when compared with G3-3D, G4-3D+MSC showed more prominent regenerated tendon fibers and better parameters of motion analysis. However, there was no significant difference in gross tear size among G2-MSC, G3-3D, and G4-3D+MSC, although these groups showed significant decreases in tear size as compared with the control group (G1-SAL).

CONCLUSION

Findings of this study show that a tissue engineering strategy based on a 3D bioprinted scaffold filled with hUCB-MSCs can improve the microenvironment for regenerative processes of FTRCT without any surgical repair.

CLINICAL RELEVANCE

In the case of rotator cuff tear, the cell loss of the external MSCs can be increased by exposure to synovial fluid. Therefore, a 3D bioprinted scaffold in combination with MSCs without surgical repair may be effective in increasing cell retention in FTRCT.

Current Concepts in Rotator Cuff Repair Techniques: Biomechanical, Functional, and Structural Outcomes

There is substantial evidence indicating that double-row (DR) repair restores more of the anatomic rotator cuff footprint and is biomechanically superior to single-row (SR) repair. Transosseous-equivalent (TOE) techniques have shown biomechanical advantages when compared with traditional DR, including increased contact at the rotator cuff footprint, higher pressure at the tendon-bone interface, and increased failure strength. Several meta-analyses of evidence level 1 and 2 studies have shown a lower rate of failed/incomplete healing when DR repair was compared with SR repair types. There is some limited evidence that TOE techniques improve healing rates in large and massive tears as compared with SR and DR. Overall, most level 1 and 2 studies have failed to prove a significant difference between SR and DR repairs in terms of clinical outcomes. However, most studies include only short-term follow-up, minimizing the impact that the higher rate of retears/failed healing seen with SR repairs can have in the long term. There are no high-quality clinical studies comparing different DR configurations, and there are currently not enough clinical data to determine the functional advantages of various DR technique modifications over one another. Although numerous biomechanical and clinical studies comparing different rotator cuff repair techniques have been published in the past decade, none has achieved universal acceptance. It is essential for the orthopaedic surgeon to know in detail the available literature to be able to apply the most appropriate and cost-effective technique in terms of healing and functional outcomes. This review provides a critical analysis of the comparative biomechanical and clinical studies among SR, DR, and TOE techniques reported in the literature in the past decade.

Arthroscopic double-row rotator cuff repair: a comprehensive review of the literature

Rotator cuff repairs seek to achieve adequate tendon fixation and to secure the fixation during the process of biological healing. Currently, arthroscopic rotator cuff repair has become the gold standard. One of the earliest defined techniques is single-row repair but the inadequacy of single-row repair to precisely restore the anatomical footprint as well as the significant rates of retear especially in large tears have led surgeons to seek other techniques. Double-row repair techniques, which have been developed in response to these concerns, have various modifications like the number and placement of anchors and suture configurations.

When the literature is reviewed, it is possible to say that double-row repairs demonstrate superior biomechanical properties. In regard to retear rates, both double row and transosseous equivalent (TOE) techniques have also yielded more favorable outcomes compared to single-row repair. But the clinical results are conflicting and more studies have to be conducted. However, it is more probable that superior structural integrity will yield better structural and functional results in the long run. TOE repair technique is regarded as promising in terms of better biomechanics and healing since it provides better footprint contact. Knotless TOE structures are believed to reduce impingement on the medial side of tendons and thus aid in tendon nutrition; however, there are not enough studies about its effectiveness.

It is important to optimize the costs without endangering the treatment of the patients. We believe that the arthroscopic TOE repair technique will yield superior results in regard to both repair integrity and functionality, especially with tears larger than 3 cm. Although defining the pattern of the tear is one of the most important guiding steps when selecting the repair technique, the surgeon should not forget to evaluate every patient individually for tendon healing capacity and functional expectations.

Knotless Fixation Is Stronger and Less Variable Than Knotted Constructs in Securing a Suture Loop

Background:

Historically, tendon-to-bone fixation has relied on knot tying. However, considerable variability exists in knot-tying strength among surgeons.

Purpose/Hypothesis:

The purpose of this study was to compare the biomechanical properties of knotted and knotless fixation and to evaluate variability among surgeons. The hypothesis was that knotless constructs would be stronger and have less variability as compared with knotted constructs.

Study Design:

Controlled laboratory study.

Methods:

A total of 34 orthopaedic surgeons participated in a laboratory study to compare knotted and knotless constructs, where 104 knotted constructs were performed with No. 2 suture, 21 knotless constructs with No. 2 suture (K2 group), and 79 knotless constructs with suture tape (KT group). Mechanical testing was performed to compare load at 3 mm of displacement, load to failure, and stiffness of each construct.

Results:

The mean load at 3 mm of displacement was greatest in the KT group, with significant differences among all 3 groups (P < .001). Load to failure was significantly greater in the KT group as compared with the K2 group and the knotted group (P < .001), but there was no difference between the K2 and knotted groups (P ≥ .999). Stiffness and displacement were also greatest in the KT group. Based on the F test, the variance in load to failure was significantly different between the knotted and knotless constructs, with the knotted group demonstrating greater variability (SD, 94 N) than the KT (SD, 38 N) and K2 (SD, 17 N) groups (P < .001).

Conclusion:

Knotless fixation with suture tape had improved biomechanical performance as compared with knots or knotless fixation with No. 2 suture. In addition, knotless fixation had less variability in biomechanical properties among multiple surgeons.

Clinical Relevance:

This study may be relevant for surgeons choosing between knotted and knotless constructs as well as for considerations in the design of rotator cuff repair constructs.

The Rotator Cuff Organ: Integrating Developmental Biology, Tissue Engineering, and Surgical Considerations to Treat Chronic Massive Rotator Cuff Tears

The torn rotator cuff remains a persistent orthopedic challenge, with poor outcomes disproportionately associated with chronic, massive tears. Degenerative changes in the tissues that comprise the rotator cuff organ, including muscle, tendon, and bone, contribute to the poor healing capacity of chronic tears, resulting in poor function and an increased risk for repair failure. Tissue engineering strategies to augment rotator cuff repair have been developed in an effort to improve rotator cuff healing and have focused on three principal aims: (1) immediate mechanical augmentation of the surgical repair, (2) restoration of muscle quality and contractility, and (3) regeneration of native enthesis structure. Work in these areas will be reviewed in sequence, highlighting the relevant pathophysiology, developmental biology, and biomechanics, which must be considered when designing therapeutic applications. While the independent use of these strategies has shown promise, synergistic benefits may emerge from their combined application given the interdependence of the tissues that constitute the rotator cuff organ. Furthermore, controlled mobilization of augmented rotator cuff repairs during postoperative rehabilitation may provide mechanotransductive cues capable of guiding tissue regeneration and restoration of rotator cuff function. Present challenges and future possibilities will be identified, which if realized, may provide solutions to the vexing condition of chronic massive rotator cuff tears.

Comparison of Passive Stiffness Changes in the Supraspinatus Muscle After Double-Row and Knotless Transosseous-Equivalent Rotator Cuff Repair Techniques: A Cadaveric Study

PURPOSE

To investigate the alteration of passive stiffness in the supraspinatus muscle after double-row (DR) and knotless transosseous-equivalent (KL-TOE) repair techniques, using shear wave elastography (SWE) in cadavers with rotator cuff tears. We also aimed to compare altered muscular stiffness after these repairs to that obtained from shoulders with intact rotator cuff tendon.

METHODS

Twelve fresh-frozen cadaveric shoulders with rotator cuff tear (tear size: small [6], medium-large [6]) were used. Passive stiffness of 4 anatomic regions in the supraspinatus muscle was measured based on an established SWE method. Each specimen underwent DR and KL-TOE footprint repairs at 30° glenohumeral abduction. SWE values, obtained at 0°, 10°, 20°, 30°, 60°, and 90° abduction, were assessed in 3 different conditions: preoperative (torn) and postoperative conditions with the 2 techniques. The increased ratio of SWE values after repair was compared among the 4 regions to assess stiffness distribution. In addition, SWE values were obtained on 12 shoulders with intact rotator cuff tendons as control.

RESULTS

In shoulders with medium-large-sized tears, supraspinatus muscles showed an increased passive stiffness after rotator cuff repairs, and this was significantly observed at adducted positions. KL-TOE repair showed uniform stiffness changes among the 4 regions of the supraspinatus muscle (mean, 189% to 218% increase after repair), whereas DR repair caused a significantly heterogeneous stiffness distribution within the muscle (mean, 187% to 319% after repair, P = .002). Although a repair-induced increase in muscle stiffness was observed also in small-sized tears, there were no significant differences in repaired stiffness changes between DR and KL-TOE (mean, 127% to 138% and 127% to 130% after repairs, respectively). Shoulders with intact rotator cuff tendon showed uniform SWE values among the 4 regions of the supraspinatus muscle (mean, 38.2 to 43.0 kPa).

CONCLUSIONS

Passive stiffness of the supraspinatus muscle increases after rotator cuff repairs for medium-large-sized tears. KL-TOE technique for the medium-large-sized tear provided a more uniform stiffness distribution across the repaired supraspinatus muscles compared with the DR technique.

CLINICAL RELEVANCE

Based on this insight, investigating rotator cuff muscle stiffness changes, further studies using SWE may determine the optimal repair technique for various sizes of rotator cuff tears.

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).

Summary of Meta-Analyses Dealing with Single-Row versus Double-Row Repair Techniques for Rotator Cuff Tears

Background:

Several meta-analyses of randomized clinical trials have been performed to analyze whether double-row (DR) rotator cuff repair (RCR) provides superior clinical outcomes and structural healing compared to single-row (SR) repair. The purpose of this study was to sum up the results of meta-analysis comparing SR and DR repair with respect on clinical outcomes and re-tear rates.

Methods:

A literature search was undertaken to identify all meta-analyses dealing with randomized controlled trials comparing clinical und structural outcomes after SR versus DR RCR.

Results:

Eight meta-analyses met the eligibility criteria: two including Level I studies only, five including both Level I and Level II studies, and one including additional Level III studies. Four meta-analyses found no differences between SR and DR RCR for patient outcomes, whereas four favored DR RCR for tears greater than 3 cm. Two meta-analyses found no structural healing differences between SR and DR RCR, whereas six found DR repair to be superior for tears greater than 3 cm tears.

Conclusion:

No clinical differences are seen between single-row and double-row repair for small and medium rotator cuff tears after a short-term follow-up period with a higher re-tear rate following single-row repairs. There seems to be a trend to superior results with double-row repair in large to massive tear sizes.

Biologic Treatments for Sports Injuries II Think Tank-Current Concepts, Future Research, and Barriers to Advancement, Part 2: Rotator Cuff

Rotator cuff tears are common and result in considerable morbidity. Tears within the tendon substance or at its insertion into the humeral head represent a considerable clinical challenge because of the hostile local environment that precludes healing. Tears often progress without intervention, and current surgical treatments are inadequate. Although surgical implants, instrumentation, and techniques have improved, healing rates have not improved, and a high failure rate remains for large and massive rotator cuff tears. The use of biologic adjuvants that contribute to a regenerative microenvironment have great potential for improving healing rates and function after surgery. This article presents a review of current and emerging biologic approaches to augment rotator cuff tendon and muscle regeneration focusing on the scientific rationale, preclinical, and clinical evidence for efficacy, areas for future research, and current barriers to advancement and implementation.

Arthroscopic double-row cuff repair with suture-bridging: a structural and functional comparison of two techniques

PURPOSE

The aim of this study was to compare the functional and structural outcomes of 2 techniques for double-row, suture-bridging cuff repair.

METHODS

A consecutive series of 73 patients who underwent arthroscopic, double-row, suture-bridge primary rotator cuff repair of full-thickness supraspinatus tear were evaluated. Thirty-eight shoulders were repaired by the arthroscopic, tied, suture-bridging technique (group A), and 35 shoulders by knot-less bridging with suture tape material (group B). Constant scores, pain, range of motion, strength, and complications were measured after a minimum follow-up period of 12 months post-operatively. Structural integrity of the repairs was evaluated systematically by either magnetic resonance imaging or computed tomography arthrography.

RESULTS

Median follow-up after surgery was 29 (23-32) months in group A, and 21 (12-23) months in group B. Mean pain relief, range of motion, strength, and constant score improved significantly in both groups. No statistical differences were found between groups in the post-operative period. According to control imaging, the re-tear rate trended to be higher in group A (23.4 %) than in group B (17.1 %), although not significantly.

CONCLUSION

Both bridging repair techniques achieved successful functional outcomes. In terms of structural outcome, the knot-less tape-bridging construct showed a lower but not significant re-tear rate. Longer follow-up is needed to confirm these results and to evaluate potential differences between the two techniques.

LEVEL OF EVIDENCE

A prospective, non-randomized, comparative study, Level III.

Clinical and structural outcomes after arthroscopic single-row versus double-row rotator cuff repair: a systematic review and meta-analysis of level I randomized clinical trials

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis of all available level I randomized controlled trials comparing single-row with double-row repair to statistically compare clinical outcomes and imaging-diagnosed re-tear rates.

METHODS

A literature search was undertaken to identify all level I randomized controlled trials comparing structural or clinical outcomes after single-row versus double-row rotator cuff repair. Clinical outcomes measures included in the meta-analysis were the American Shoulder and Elbow Surgeons, University of California-Los Angeles, and Constant scores; structural outcomes included imaging-confirmed re-tears. Meta-analyses compared raw mean differences in outcomes measures and relative risk ratios for imaging-diagnosed re-tears after single-row or double-row repairs by a random-effects model.

RESULTS

The literature search identified a total of 7 studies that were included in the meta-analysis. There were no significant differences in preoperative to postoperative change in American Shoulder and Elbow Surgeons, University of California-Los Angeles, or Constant scores between the single-row and double-row groups (P = .440, .116, and .156, respectively). The overall re-tear rate was 25.9% (68/263) in the single-row group and 14.2% (37/261) in the double-row group. There was a statistically significant increased risk of sustaining an imaging-proven re-tear of any type in the single-row group (relative risk, 1.76 [95% confidence interval, 1.25-2.48]; P = .001), with partial-thickness re-tears accounting for the majority of this difference (relative risk, 1.99 [95% confidence interval, 1.40-3.82]; P = .039).

CONCLUSION

Single-row repairs resulted in significantly higher re-tear rates compared with double-row repairs, especially with regard to partial-thickness re-tears. However, there were no detectable differences in improvement in outcomes scores between single-row and double-row repairs.

Biomechanical effects of a 2 suture-pass medial inter-implant mattress on transosseous-equivalent rotator cuff repair and considerations for a "technical efficiency ratio"

BACKGROUND

Rotator cuff repair involving fewer tendon suture passes without compromising biomechanical performance would represent a technical advancement. An inter-implant "medial pulley-mattress" transosseous-equivalent (MP-TOE) repair requiring fewer tendon suture-passes was hypothesized to provide equivalent biomechanical characteristics compared to the control.

METHODS

In 6 human cadaveric shoulders, a transosseous-equivalent (TOE) repair (control) was performed utilizing 2 separate medial mattresses resulting in 4 tendon-bridging sutures. In 6 matched-pairs, 2 single-loaded anchors were used to create a medial inter-implant mattress construct (all sutures shuttled in 1 tendon pass per anchor)-after knot-tying, the same tendon-bridging pattern as the control was created. A materials testing machine cyclically loaded each repair from 10-180 N for 30 cycles; each repair subsequently underwent failure testing. Gap and strain were measured with a video digitizing system. A "technical efficiency ratio" (TER) was defined as: (#knots + #suture passes + #suture limbs)/#fixation points.

RESULTS

Cyclic and failure testing demonstrated no significant differences between constructs. Gap formation at cycle 30 was 5.3 ± 0.8 mm (TOE) and 5.0 ± 0.3 mm (MP-TOE) (P = .62). Cycle 30 anterior strain values were -16.0 ± 7.3% (TOE) and -15.8 ± 6.6% (MP-TOE) (P = .99). Yield loads were 208.7 ± 2.7 N (TOE) and 204.0 ± 1.3 N (MP-TOE) (P = .17). Mode of failure demonstrated less tendon cut-out with the MP-TOE repair. The MP-TOE repair has a TER of 2.0 vs 2.5 for the control.

CONCLUSION

The MP-TOE repair requiring fewer tendon suture passes, yet creating an additional inter-implant mattress configuration, is biomechanically equivalent to the original TOE technique, and may limit failure with improved medial load-sharing capacity. A TER may help quantify technical ease and help standardize comparisons between repair techniques.

Cellular therapy in bone-tendon interface regeneration

The intrasynovial bone-tendon interface is a gradual transition from soft tissue to bone, with two intervening zones of uncalcified and calcified fibrocartilage. Following injury, the native anatomy is not restored, resulting in inferior mechanical properties and an increased risk of re-injury. Recent in vivo studies provide evidence of improved healing when surgical repair of the bone-tendon interface is augmented with cells capable of undergoing chondrogenesis. In particular, cellular therapy in bone-tendon healing can promote fibrocartilage formation and associated improvements in mechanical properties. Despite these promising results in animal models, cellular therapy in human patients remains largely unexplored. This review highlights the development and structure-function relationship of normal bone-tendon insertions. The natural healing response to injury is discussed, with subsequent review of recent research on cellular approaches for improved healing. Finally, opportunities for translating in vivo findings into clinical practice are identified.

Rotator cuff tendon repair morphology comparing 2 single-anchor repair techniques

PURPOSE

To compare the effect of 2 common rotator cuff repair techniques, for smaller tears limited to the use of a single anchor, on tendon morphology in relation to the footprint.

METHODS

Six matched pairs of human shoulders were dissected, and a standardized 10-mm supraspinatus tendon tear was created. Two single-anchor repairs were performed: simple repair with the anchor on the footprint or inverted-mattress repair with the anchor 1 cm distal-lateral to the footprint. The repaired specimens were frozen in situ with liquid nitrogen. Coronal cross sections through the intact and repaired tendon were made. A digitizer was used to measure variables including tendon area and radius of tendon curvature.

RESULTS

Comparing between repairs, we found significantly more gap formation for the simple repair at the repair cross section (3.67 ± 0.32 mm v 0.68 ± 0.10 mm, P = .00050). The simple repair had less tendon area (38.28 ± 2.50 mm(2)v 58.65 ± 4.06 mm(2), P = .0036) and a smaller radius of curvature (8.47 ± 1.39 mm v 32.51 ± 3.94 mm, P = .0046). For the simple repair, there was significantly more gap formation, less tendon area, and a smaller radius of tendon curvature for all repair cross sections compared with the intact cross sections (P < .05). For the inverted-mattress repair, there was more gap formation compared with the intact condition (P < .05), although it was less than 1 mm on average; for tendon area, radius of curvature, and tendon height, the cross section centered on the repair showed no differences compared with the intact control.

CONCLUSIONS

For rotator cuff tears that are 10 mm or smaller and limited to the use of a single anchor, using a distal-lateral anchor position with tape-type suture can provide better maintenance of native tendon morphology and footprint dimensions when compared with repair that uses standard sutures and places the anchor on the footprint.

CLINICAL RELEVANCE

For smaller tears, the inverted-mattress repair described in this article may provide a relatively improved healing environment compared with a simple repair on the footprint, potentially optimizing the prevention of early tear progression.

Arthroscopic rotator cuff repair: techniques in 2012

Techniques for arthroscopic partial-thickness and full-thickness RTC repairs continue to advance. When selecting an RTC repair technique, it is important to identify the tear pattern and adhere to the fundamentals of tendon mobilization and footprint preparation. Partial RTC tears greater than 50% in thickness can be reproducibly repaired with tear completion or transtendinous techniques with good clinical outcomes. Based on the available literature, small, less than 1-cm RTC tears can effectively be repaired with single-row techniques. Tears sized 1 cm to 3 cm can be repaired with either single-row, double-row, or transosseous-equivalent techniques based on surgeon comfort, tendon quality, and tissue mobility. Tears greater than 3 cm have shown superior results when transosseous-equivalent techniques are used. Further clinical studies are needed to definitively conclude the ideal RTC repair technique.