Platelet-rich plasma in the management of rotator cuff tendinopathy.

Platelet-rich plasma (PRP) is an autologous blood-derived product that has gained significant attention in the treatment of tendinopathies as one of many treatment modalities in the field of regenerative medicine. Rotator cuff pathologies are the leading cause of shoulder pain. Despite the high success rate with conservative treatment and arthroscopic surgical repair, the search for a nonsurgical treatment has made PRP a trending topic recently. The purpose of this article is to review the recent literature data on the possible role of PRP in different rotator cuff pathologies. The limited data in the literature about isolated tendinopathies without a tear (tendonitis and tendinosis) suggests potential benefit from conservative treatment with PRP. Many studies exist for the treatment of rotator cuff tears solely using PRP or as an augmentation to arthroscopic repair. Despite the large number of randomized clinical trials and meta-analyses about the topic, there is no consensus in favor of routine application of PRP in this patient population. The existing reliable evidence of benefit seems to be restricted to its use in only inflammatory tendinopathies with preserved tendon integrity.

Rotator Cuff Tendinopathy: Pathways of Apoptosis.

Rotator cuff repair is usually successful, but retear is not uncommon. It has been previously identified that there is a higher incidence of apoptosis in the edges of the torn supraspinatus tendon. A prospective cohort study was conducted with 28 patients-14 rotator cuff tear patients, 5 instability patients, and 9 Anterior cruciate ligament reconstruction patients to determine whether there was any increase in several genes implicated in apoptosis, including Fas receptor (FasR), Fas ligand, Aifm-1, Bcl-2, Fadd, Bax, and caspase-3. There was a significant expression of Bax (P=0.2) and FasR (P=0.005) in the edges of torn supraspinatus tendons, and in intact subscapularis tendons, there was a significant expression of caspase-3 (P=0.02) compared with samples from the torn supraspinatus tendon (P=0.04). The cytochrome c pathway, with its subsequent activation of caspase-3, as well as the TRAIL-receptor signaling pathway involving FasR have both been implicated. The elevated expression of Bax supported the model that the Bax to Bcl-2 expression ratio represents a cell death switch. The elevated expression of Bax in the intact subscapularis tissue from rotator cuff tear patients also may confirm that tendinopathy is an ongoing molecular process.

The subacromial bursa modulates tendon healing after rotator cuff injury in rats.

Rotator cuff injuries result in more than 500,000 surgeries annually in the United States, many of which fail. These surgeries typically involve repair of the injured tendon and removal of the subacromial bursa, a synovial-like tissue that sits between the rotator cuff and the acromion. The subacromial bursa has been implicated in rotator cuff pathogenesis and healing. Using proteomic profiling of bursa samples from nine patients with rotator cuff injury, we show that the bursa responds to injury in the underlying tendon. In a rat model of supraspinatus tenotomy, we evaluated the bursa's effect on the injured supraspinatus tendon, the uninjured infraspinatus tendon, and the underlying humeral head. The bursa protected the intact infraspinatus tendon adjacent to the injured supraspinatus tendon by maintaining its mechanical properties and protected the underlying humeral head by maintaining bone morphometry. The bursa promoted an inflammatory response in injured rat tendon, initiating expression of genes associated with wound healing, including Cox2 and Il6. These results were confirmed in rat bursa organ cultures. To evaluate the potential of the bursa as a therapeutic target, polymer microspheres loaded with dexamethasone were delivered to the intact bursae of rats after tenotomy. Dexamethasone released from the bursa reduced Il1b expression in injured rat supraspinatus tendon, suggesting that the bursa could be used for drug delivery to reduce inflammation in the healing tendon. Our findings indicate that the subacromial bursa contributes to healing in underlying tissues of the shoulder joint, suggesting that its removal during rotator cuff surgery should be reconsidered.

Fixation technique of biodegradable magnesium alloy suture anchor in the rotator cuff repair of the shoulder in a goat model: a technical note.

BACKGROUND: Shoulder disorders, particularly rotator cuff tears, are prevalent musculoskeletal conditions related to aging. Although the widely used suture anchor technique provides strong mechanical support to the tendon, it is associated with a risk of postoperative tendon retearing. The conventionally used titanium alloys can affect the interpretation of magnetic resonance imaging. Degradable magnesium alloys possess excellent biocompatibility, similar mechanical property to the bone, and stimulating bone formation ability from Mg2+. The purpose of this experiment was to develop innovative magnesium-based suture anchors to enhance rotator cuff repair by improving fixation materials, and to evaluate their feasibility in a goat model. METHODS: We developed fluoridized ZK60 suture anchors as the implantation material for two goats, who underwent rotator cuff repair surgery on both shoulders. Computed tomography (CT) and histological analysis were performed at 12 weeks postoperatively, and the results were compared between the magnesium and titanium alloy groups. Additionally, a hematological examination was conducted, which included assessments of red blood cells, white blood cells, platelets, coagulation function, liver function, kidney function, and magnesium ion concentration. RESULTS: The 12-week postoperative CT images showed intact MgF2 ZK60 suture anchors, effectively reconnecting the infraspinatus tendon to the humeral head. The anchors became less visible on CT scans, indicating absorption by surrounding tissues. New bone formation in the MgF2 group surpassed that in the Ti group, demonstrating superior osseointegration. The similarity between cortical bone and magnesium reduced stress-shielding and promoted bone regeneration. Histological analysis revealed successful tendon healing with MgF2 anchors, while the Ti group showed discontinuous interfaces and reduced collagen secretion. Hematological examination showed stable liver, renal function, and magnesium ion levels. CONCLUSIONS: The findings indicate that MgF2-coated suture anchors are feasible for rotator cuff repair and potentially other orthopedic applications. We hope that magnesium alloy anchors can become the solution for rotator cuff tendon repair surgery.

Semi-Bone Tunnel Technique Using Double-Row Suture Bridge Combined With Platelet-Rich Plasma Hydrogel for Rotator Cuff Repair in a Rabbit Model.

BACKGROUND: The approach to managing the footprint area and reconstructing the tendon-bone interface (TBI) is critical for optimal healing. PURPOSE: To evaluate the outcomes of the semi-bone tunnel (SBT) technique using a double-row suture bridge combined with platelet-rich plasma (PRP) hydrogel for rotator cuff repair in a rabbit model. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 48 New Zealand White rabbits were divided into 4 groups. The supraspinatus tendons were severed at the footprint to create a rotator cuff tear model in the surgical groups. Rabbits were treated with the traditional onto-surface repair (control group), SBT technique (SBT group), and SBT technique combined with PRP hydrogel implantation (SBT+PRP group). The rabbits without surgery were the normal group. At 8 weeks after surgery, macroscopic observation, magnetic resonance imaging (MRI) and micro-computed tomography (µCT) examinations, histological evaluations, and biomechanical tests were performed to assess the curative effects of the given treatments. RESULTS: The MRI results showed that the repaired supraspinatus tendon presented a uniform signal, minimal inflammatory response, and the lowest signal-to-noise quotient value in the SBT+PRP group. The µCT results suggested that the SBT technique did not reduce the local bone mineral density in the TBI area compared with the onto-surface repair technique. The histological staining results showed that the regenerated TBI in the SBT+PRP group had a 4-layer structure similar to the natural tissue. The highest values for biomechanical properties were observed in the SBT+PRP group, and there was no significant difference between the SBT+PRP group and normal group. CONCLUSION: The SBT technique presented a better tendon-bone healing effect for rotator cuff tear in the rabbit model compared with the traditional onto-surface repair technique. The specimens in the SBT+PRP group had a similar TBI structure and biomechanical properties to the natural tissue. CLINICAL RELEVANCE: The SBT technique can be an alternative surgical approach for rotator cuff repair, especially for moderate to large tears and cases requiring scaffold implantation.

The association between a rotator cuff tendon tear and a tear of the long head of the biceps tendon: Chart review study.

Rotator cuff (RC) and long head of the biceps tendon (LHBT) tears are common shoulder problems presented to the orthopedic clinic. The aim of this study was to assess the association between RC and LHBT tears among a Saudi population sample. A total of 243 patients who were diagnosed with shoulder pain due to RC or LHBT tear between 2016 and 2018 using a magnetic resonance imaging scan were included in this study. Females comprised 66% of the sample, and 59% (n = 143) of the shoulders were on the right side. The mean age of the patients was 58 ± 11 years, ranging from 23 to 88 years. A significant association was detected between the LHBT and RC tears (P < 0.001). Out of 26 cases showing RC and LHBT tears, 81% had a full thickness tear, whereas 19% had a partial tear. The LHBT tears were presented significantly in 48% of cases with at least two completely torn RC compared to 10% in cases with one completely torn RC (P < 0.001). The LHBT tear was significantly observed in shoulders with RC tears including the tendons of subscapularis, supraspinatus, and infraspinatus, but not the teres minor (P < 0.001). Both types of tears were presented significantly in senior patients aged more than 65 years compared to younger patients (P < 0.01). Thus, the LHBT should be assessed carefully in shoulders with more than one RC tear or in chronic cases.

The Relationship Among Probable SARCopenia, Osteoporosis and SuprasPinatus Tendon Tears in Postmenopausal Women: The SARCOSP Study.

We aimed to investigate the relationship among probable sarcopenia, osteoporosis (OP) and supraspinatus tendon (SSP) tears in postmenopausal women. Postmenopausal women screened/followed for OP were recruited. Demographic data, comorbidities, exercise/smoking status, and handgrip strength values were recorded. Probable sarcopenia was diagnosed as handgrip strength values < 20 kg. Achilles and SSP thicknesses were measured using ultrasound. Among 1443 postmenopausal women, 268 (18.6%) subjects had SSP tears. Unilateral tears were on the dominant side in 146 (10.1%) and on the non-dominant side in 55 women (3.8%). In contrast to those without, women with SSP tears had older age, lower level of education, thinner SSP and lower grip strength (all p < 0.05). In addition, they had higher frequencies of hypertension, hyperlipidemia, DM, OP and probable sarcopenia, but lower exercise frequency (all p < 0.05). Binary logistic regression modeling revealed that age [odds ratio (OR): 1.046 (1.024-1.067 95% CI)], hypertension [OR: 1.560 (1.145-2.124 95% CI)], OP [OR: 1.371 (1.022-1.839 95% CI)] and probable sarcopenia [OR: 1.386 (1.031-1.861 95% CI)] were significant predictors for SSP tears (all p < 0.05). This study showed that age, presence of hypertension, probable sarcopenia and OP were related with SSP tears in postmenopausal women. To this end, although OP appeared to be related to SSP tears, SSP tear/thickness evaluation can be recommended for OP patients, especially those who have other risk factors such as older age, higher BMI, hypertension, and probable sarcopenia.

Differences in Clinical Outcomes Between Patients With Retear After Supraspinatus Tendon Repair and Those With Intact Repair at 5-Year Follow-up.

BACKGROUND: It is well known that rotator cuff repair is associated with an overall retear rate of 21% to 26%. However, a cuff retear may not necessarily be associated with poor clinical outcomes. HYPOTHESIS: There would be no difference in clinical outcomes between patients with a cuff retear and those with an intact repair at a midterm follow-up of 5 years. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective study was conducted involving patients who received arthroscopic complete repair of the supraspinatus tendon between January 2009 and December 2017. Patients who did not have a postoperative magnetic resonance imaging (MRI) scan or who had a follow-up of <5 years were excluded. Clinical outcomes, including the visual analog scale (VAS) score, American Shoulder and Elbow Surgeons (ASES) score, and active forward flexion (FF) of the involved shoulder were assessed at the 2-year and 5-year follow-up points. RESULTS: The study group included 105 patients with a mean follow-up of 85 months. MRI scans were performed at a mean of 20 months. Fourteen full-thickness cuff retears and 91 intact repairs were identified using postoperative MRI scans. Significant improvement in VAS score, ASES score, and FF were found between the preoperative assessment and the 2 designated follow-up points (2 years and 5 years) in both the cuff retear and the intact repair groups (P < .001). The VAS and ASES scores at the 2-year follow-up for the intact repair group were 1.8 ± 2.0 and 80.7 ± 18.1, respectively. The corresponding values for the retear group were 2.3 ± 2.2 and 71.9 ± 19.5, respectively. No significant difference was found between the 2 groups in the VAS and ASES scores at the 2-year follow-up. However, patients with an intact repair had a better VAS score (1.4 ± 1.8; P = .049) and ASES score (81.7 ± 17; P = .019) than those with a cuff retear at the 5-year assessment (3.0 ± 2.8 and 67.1 ± 22.9, respectively). In the intact repair group, 91% of patients achieved the minimal clinically important difference for the 5-year VAS score, compared with 54% in the cuff retear group (P < .001). The corresponding values for the 5-year ASES score were 80% and 54%, respectively (P = .044). FF measurements at the 5-year follow-up in patients with intact repair and those with a cuff retear were 161°± 23° and 144°± 37°, respectively (P = .059). Continuous improvement in VAS score and FF between the 2-year and 5-year follow-up was observed in the intact repair group (P = .005 and P = .04, respectively). CONCLUSION: The patients with an intact repair had better VAS and ASES scores compared with those who had a cuff retear at a midterm follow-up of 5 years. Between the 2-year and the 5-year follow-up, some further improvement was observed in the VAS score and FF in the intact repair group.

In-situ gelation of fibrin gel encapsulating platelet-rich plasma-derived exosomes promotes rotator cuff healing.

Although platelet-rich plasma-derived exosomes (PRP-Exos) hold significant repair potential, their efficacy in treating rotator cuff tear (RCT) remains unknown. In light of the potential for clinical translation of fibrin gel and PRP-Exos, we evaluated their combined impact on RCT healing and explored suitable gel implantation techniques. In vitro experiments demonstrated that PRP-Exos effectively enhanced key phenotypes changes in tendon stem/progenitor cells. Multi-modality imaging, including conventional ultrasound, shear wave elastography ultrasound, and micro-computed tomography, and histopathological assessments were performed to collectively evaluate the regenerative effects on RCT. The regenerated tendons exhibited a well-ordered structure, while bone and cartilage regeneration were significantly improved. PRP-Exos participated in the healing process of RCT. In-situ gelation of fibrin gel-encapsulated PRP-Exos at the bone-tendon interface during surgery proved to be a feasible gel implantation method that benefits the healing outcome. Comprehensive multi-modality postoperative evaluations were necessary, providing a reliable foundation for post-injury repair.

Natural History of Quantitative Fatty Infiltration and 3D Muscle Volume After Nonoperative Treatment of Symptomatic Rotator Cuff Tears: A Prospective MRI Study of 79 Patients.

BACKGROUND: The severity of fatty infiltration (FI) predicts the treatment outcome of rotator cuff tears. The purpose of this investigation was to quantitatively analyze supraspinatus (SSP) muscle FI and volume at the initial presentation and after a 3-month minimum of conservative management. We hypothesized that progression of FI could be predicted with initial tear size, FI, and muscle volume. METHODS: Seventy-nine shoulders with rotator cuff tears were prospectively enrolled, and 2 magnetic resonance imaging (MRI) scans with 6-point Dixon sequences were acquired. The fat fraction within the SSP muscle was measured on 3 sagittal slices, and the arithmetic mean was calculated (FI SSP ). Advanced FI SSP was defined as ≥8%, pathological FI SSP was defined as ≥13.5%, and relevant progression was defined as a ≥4.5% increase in FI SSP . Furthermore, muscle volume, tear location, size, and Goutallier grade were evaluated. RESULTS: Fifty-seven shoulders (72.2%) had normal FI SSP , 13 (16.5%) had advanced FI SSP , and 9 (11.4%) had pathological FI SSP at the initial MRI scan. Eleven shoulders (13.9%) showed a ≥4.5% increase in FI SSP at 19.5 ± 14.7 months, and 17 shoulders (21.5%) showed a ≥5-mm 3 loss of volume at 17.8 ± 15.3 months. Five tears (7.1%) with initially normal or advanced FI SSP turned pathological. These tears, compared with tears that were not pathological, had significantly higher initial mediolateral tear size (24.8 compared with 14.3 mm; p = 0.05), less volume (23.5 compared with 34.2 mm 3 ; p = 0.024), more FI SSP (9.6% compared with 5.6%; p = 0.026), and increased progression of FI SSP (8.6% compared with 0.5%; p < 0.001). An initial mediolateral tear size of ≥20 mm yielded a relevant FI SSP progression rate of 81.8% (odds ratio [OR], 19.0; p < 0.001). Progression rates of 72.7% were found for both initial FI SSP of ≥9.9% (OR, 17.5; p < 0.001) and an initial anteroposterior tear size of ≥17 mm (OR, 8.0; p = 0.003). Combining these parameters in a logistic regression analysis led to an area under the receiver operating characteristic curve (AUC) of 0.913. The correlation between FI SSP progression and the time between MRI scans was weak positive (ρ = 0.31). CONCLUSIONS: Three risk factors for relevant FI progression, quantifiable on the initial MRI, were identified: ≥20-mm mediolateral tear size, ≥9.9% FI SSP , and ≥17-mm anteroposterior tear size. These thresholds were associated with a higher risk of tear progression: 19 times higher for ≥20-mm mediolateral tear size, 17.5 times higher for ≥9.9% FI SSP , and 8 times higher for ≥17-mm anteroposterior tear size. The presence of all 3 yielded a 91% chance of ≥4.5% progression of FI SSP within a mean of 19.5 months. LEVEL OF EVIDENCE: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Editorial Commentary: Improved Suture Configurations Can Enhance Shoulder Rotator Cuff Healing: The Cuff Doesn't Always Heal-But We Can Nudge It in the Right Direction.

The success of rotator cuff repair is often measured by patient-reported outcomes or structural healing on magnetic resonance imaging. Ideally, we can achieve both a satisfied patient and a healed tendon. Various technical modifications and stitch patterns have been presented in an effort to achieve the perfect rotator cuff repair. It appears the independently popular suture bridge technique and Mason-Allen stitch may do their best work when combined together. First, double-row repair "anchors down" the tendon to its footprint, and suture bridge adds to this concept with double-row compressive interlinking suture. Second, the Mason-Allen stitch, combining a horizontal stich and a simple stitch that passes around the horizontal, leverages the rip-stop concept where an "anchor suture" is included as a suture is passed around friable tendon like steel rebar rods strengthening concrete. In the midst of many factors out of the surgeon's control during the healing process, we are compelled to listen when a change in our technique might actually make a difference.

Dual Growth Factor Delivery Using Photo-Cross-Linkable Gelatin Hydrogels for Effectively Reinforced Regeneration of the Rotator Cuff Tendon.

Rotator cuff tears are currently treated with drugs (steroids and nonsteroidal anti-inflammatory drugs) and surgery. However, the damaged rotator cuff requires a considerable amount of time to regenerate, and the regenerated tissue cannot restore the same level of function as that before the damage. Although growth factors can accelerate regeneration, they are difficult to be used alone because of the risk of degradation and the difficulties in ensuring their sustained release. Thus, hydrogels such as gelatin are used, together with growth factors. Gelatin is a biocompatible and biodegradable hydrogel derived from collagen; therefore, it closely resembles the components of native tissues and can retain water and release drugs continuously, while also showing easily tunable mechanical properties by simple modifications. Moreover, gelatin is a natural biopolymer that possesses the ability to form hydrogels of varying compositions, thereby facilitating effective cross-linking. Therefore, gelatin can be considered to be suitable for rotator-to-tendon healing. In this study, we designed photo-cross-linkable gelatin hydrogels to enhance spacing and adhesive effects for rotator cuff repair. We mixed a ruthenium complex (Ru(II)bpy32+) and sodium persulfate into gelatin-based hydrogels and exposed them to blue light to induce gelation. Basic fibroblast growth factor and bone morphogenetic protein-12 were encapsulated in the gelatin hydrogel for localized and sustained release into the wound, thereby enhancing the cell proliferation. The effects of these dual growth factor-loaded hydrogels on cell cytotoxicity and tendon regeneration in rotator cuff tear models were evaluated using mechanical and histological assessments. The findings confirmed that the gelatin hydrogel was biocompatible and that treatment with the dual growth factor-loaded hydrogels in in vivo rotator cuff tear models promoted regeneration and functional restoration in comparison with the findings in the nontreated group. Therefore, growth factor-loaded gelatin-based hydrogels may be suitable for the treatment of rotator cuff tears.

Can three-dimensional models enhance understanding and knowledge of rotator cuff tears?

OBJECTIVES: Magnetic resonance imaging (MRI) is currently the standard diagnostic tool for rotator cuff tears. However, its two-dimensional (2D) output, displayed on a monitor, can complicate the interpretation of anatomy. Three-dimensional (3D) imaging may offer a solution to this issue. This study aimed to demonstrate the diagnostic and interpretive value of a 3D model in assessing lesion anatomy. The hypothesis was that 3D models, compared to 2D MRI, can enhance the comprehension and knowledge of rotator cuff injuries, improve the application of classifications for total tears, and provide a more precise definition of the size and type of tear. METHODS: A prospective single-centre study was conducted. 3D models for rotator cuff tears were created and analysed in conjunction with preoperative MRI for each patient up to 2 months before surgery. The 3D models were based on the preoperative MRI. Collected data included 2D plane measurements by MRI in coronal and sagittal planes, descriptions of 3D lesion geometry (new shapes), 3D measurements in coronal and sagittal planes, arthroscopic classifications of rotator cuff injuries, and arthroscopic measurements in coronal and sagittal planes. RESULTS: After examining 25 cases, 3D imaging demonstrated similar arthroscopic values post-bursectomy in the sagittal plane (16.70 â€‹mm for 3D and 18.28 â€‹mm for post-bursectomy, p-value â€‹= â€‹0.189), although these measurements did not align with those of MRI (which underestimated measurements, p-value â€‹= â€‹0.010). Both MRI measurement and 3D imaging showed similar measurement accuracy in the coronal plane when compared to arthroscopic measurements taken before and after bursectomy. The creation of 3D objects enabled the analysis of new geometries, including the length, width, and depth of each lesion. These geometries included the rectangle, rectangular trapezoid, scalene trapezoid, irregular pentagon, and irregular hexagon. CONCLUSIONS: 3D models can enhance the understanding and knowledge of rotator cuff injuries. They can be a promising tool for diagnosing and interpreting the anatomy of the injury, particularly in the sagittal plane. The new 3D understanding of the pathological process has led to the description of new geometric features not visible in conventional 2D MRI. LEVEL OF EVIDENCE: II - Development of diagnostic criteria on consecutive patients (all compared to "gold" standard).

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.

Fibroblast Growth Factor Soaked Collagen Membrane Shows No Biomechanical or Histological Advantages in the Treatment of Chronic Rotator Cuff Tears in a Rabbit Model.

PURPOSE: To investigate the histological and biomechanical effects of a fibroblast growth factor (FGF-2)-soaked collagen membrane used to treat a full-thickness chronic rotator cuff (RC) rupture in a rabbit model. METHODS: Forty-eight shoulders from 24 rabbits were used. At the beginning of the procedure, 8 rabbits were killed to assess the control group (Group IT) with intact tendons. To establish a chronic RC tear model, a full-thickness subscapularis tear was created on both shoulders of the remaining 16 rabbits and left for 3 months. The transosseous mattress suture technique was used to repair tears in the left shoulder (Group R). The tears in the right shoulder (Group CM) were treated using the same approach, with an FGF-soaked collagen membrane inserted and sutured over the repair site. Three months after the procedure, all rabbits were killed. Biomechanical testing was performed on the tendons to determine failure load, linear stiffness, elongation intervals, and displacement. Histologically, the modified Watkins score was used to evaluate tendon-bone healing. RESULTS: There was no significant difference among the three groups in terms of failure load, displacement, linear stiffness, and elongation (P > .05). The total modified Watkins score was not affected by applying the FGF-soaked collagen membrane to the repair site (P > .05). Fibrocytes, parallel cells, large-diameter fibers, and the total modified Watkins score were significantly lower in both repair groups when compared to the intact tendon group (P < .05). CONCLUSIONS: In addition to tendon repair, FGF-2 soaked collagen membrane -application at the repair site provides neither biomechanical nor histological advantages in the treatment of chronic RC tears. CLINICAL RELEVANCE: FGF-soaked collagen membrane augmentation provides no impact on the chronic RC tear healing tissue. The need to investigate alternative methods that may have a positive effect on healing in chronic RC repairs continues.

An All-Suture Anchor Offers Equivalent Clinical Performance to an Established Solid Suture Anchor in the Arthroscopic Repair of Rotator Cuff Tears: A Prospective, Randomized, Multicenter Trial With 12-Month Follow-Up.

PURPOSE: To evaluate the safety and efficacy of a next-generation, all-suture anchor in patients undergoing arthroscopic repair of rotator cuff tears, compared with that of an established solid suture anchor. METHODS: Between April 2019 and January 2021, a prospective, comparative, randomized controlled noninferiority study conducted on people with Chinese ethnicity at 3 tertiary hospitals enrolled patients (18-75 years) requiring arthroscopic treatment for rotator cuff tears. Patients were randomized into 2 cohorts receiving either all-suture anchor or solid suture anchor and followed for 12 months. The primary outcome was the Constant-Murley score at the 12-month follow-up. Magnetic resonance imaging assessments determined the rate of retear of rotator cuff repair (defined as Sugaya classification 4 and 5). Safety evaluation was performed at all follow-up points to determine the adverse events (AEs). RESULTS: In total, 120 patients with rotator cuff tears (mean age, 58.3 years; 62.5% female; 60 receiving all-suture anchor) underwent treatment. Five patients were lost to follow-up. Both cohorts showed significant improvement in Constant-Murley scores between baseline and 6 months (P < .001) and between 6 and 12 months (P < .001). There were no significant differences in Constant-Murley scores between the 2 cohorts at 12 months (P = .122) after operation. The retear rate at 12 months was 5.7% and 1.9% in the all-suture and solid suture anchor cohorts, respectively (P = .618). There were 2 cases of intraoperative anchor pullout, both of which were successfully resolved. No cases of postoperative reoperation or other anchor-related AEs were reported. CONCLUSIONS: The all-suture anchor offered equivalent clinical performance to an established solid suture anchor at the 12-month follow-up in patients undergoing arthroscopic repair of rotator cuff tears. The retear rate was not statistically significantly different between the 2 cohorts. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Clinical outcomes of medialized single-row repair with fascia lata graft augmentation for large and massive rotator cuff tears.

BACKGROUND: A high postoperative retear rate after arthroscopic rotator cuff repair (ARCR) of large and massive tears remains a problem. This study evaluated rotator cuff integrity after ARCR with fascia lata graft augmentation for large and massive rotator cuff tears and compared clinical outcomes between patients with intact repairs and retears. METHODS: Forty-five patients with rotator cuff tears who could not undergo primary repair due to tendon retraction underwent arthroscopic medialized single-row repair with fascia lata graft augmentation. The patients' minimum follow-up was 2 (2-9) years. Supraspinatus cuff integrity was evaluated postoperatively by magnetic resonance imaging. We compared the clinical outcomes of patients with intact repairs vs. retears based on the University of California-Los Angeles (UCLA), Constant, and Japanese Orthopaedic Association (JOA) scores. We also evaluated their range of motion (ROM) and muscle strength. RESULTS: Retears were observed in 11 of 45 patients. UCLA, Constant, and JOA scores significantly improved postoperatively compared to preoperatively in the intact repair (all P < .001) and retear (all P < .036) groups. The intact repair group had significantly higher Constant (75.6 [mean] ± 9.9 [SD] vs. 69.8 ± 7.9; P = .026) and JOA (94.4 ± 6.9 vs. 89.8 ± 5.9; P = .041) scores than the retear group. Forward elevation, abduction, and the strengths of abduction and external rotation significantly improved in the intact repair group (all P < .003) but not in the retear group (all P > .05). The intact repair group had significantly higher postoperative forward flexion (165° ± 15° vs. 154° ± 23°; P = .036), abduction (164° ± 17° vs. 151° ± 26°; P = .029), and abduction strength (3.5 ± 2.2 kg vs. 2.3 ± 1.2 kg; P = .017) than the retear group. In the intact repair group (n = 34), Sugaya type I:II ratio differed significantly between postoperative 3 months (2:32) and 24 months (24:10) (P < .001). Repaired tendon thickness did not decrease significantly between 3 months (7.1 mm) and 2 years (6.9 mm) (P = .543). CONCLUSIONS: ARCR with fascia lata graft augmentation of large and massive rotator cuff tears showed a 24.4% retear rate but significantly improved the clinical scores, ROMs, and muscle strength with excellent cuff integrity in the intact repair group. However, the differences in the Constant and UCLA scores between the intact repair and retear groups were under the minimal clinically important difference, and their clinical significance is uncertain. Our results confirm that ARCR with fascia lata graft augmentation improves patients' postoperative outcomes if the repair site is maintained postoperatively.

Estrogen and testosterone supplementation improves tendon healing and functional recovery after rotator cuff repair.

Failure of healing after rotator cuff repair (RCR) is common. The purpose of the current study was to evaluate the effect of systemic estrogen or testosterone supplementation on tendon healing after RCR. Seventy-two adult male mice were utilized for all experiments. The supraspinatus tendon was transected and repaired with 6-0 Prolene suture on the left shoulder of 51 animals. Mice were segregated into three groups postoperative: (1) vehicle group (VG; n = 18), (2) estrogen group (EST; n = 17), and (3) testosterone group (TST; n = 16). An unrepaired control group (unrepaired, n = 21) did not have surgery. Utilizing these animals, histological analysis, activity testing, biomechanical testing and RNA sequencing (RNA-seq) was performed. At 8 weeks post-RCR, TST, and EST supplementation improved the overall histologic structure of the repaired enthesis site. No differences in ultimate failure loads or stiffness were detected between VG, EST, and TST groups after biomechanical testing. RCR caused a reduction in wheel activity compared to unrepaired controls and supplementation with TST restored wheel activity. RNA-seq analysis indicated that estrogen and testosterone regulated different pathways associated with enthesis healing, including a suppression of inflammatory signaling. Supplementation with sex hormones improved the structure of the repaired tendon enthesis and significantly regulated expression of diverse pathways regulating multiple biological processes. Testosterone administration following RCR restored wheel activity without having a detrimental impact on biomechanical strength. Future human studies of sex hormone supplementation after RCR are warranted as supplementation in an animal model may improve tendon enthesis healing.

Risk factors for intracellular fatty accumulation in rotator cuff muscle: a histologic analysis.

BACKGROUND: Fatty accumulation in rotator cuff muscles has been associated with shoulder dysfunction, risk of repair failure, and poor postoperative outcomes. This study sought to assess risk factors associated with true fatty accumulation based on histologic analysis and determine whether preoperative function directly correlated with this fatty rotator cuff accumulation. METHODS: Supraspinatus muscle biopsy specimens obtained prospectively from patients undergoing arthroscopic rotator cuff repair were stained with LipidTOX to quantify lipid accumulation. Two-step cluster analysis with Goutallier classification was used to define the fatty and non-fatty rotator cuff groups. We further performed a receiver operating characteristic curve analysis to confirm the group cutoff values. RESULTS: In total, 51 patients (aged 60.1 ± 10.5 years) were included. There were 19 high-grade partial tears, 10 small tears, 7 medium tears, 10 large tears, and 5 massive tears. Both cluster and receiver operating characteristic curve analyses yielded a cutoff value of 30% LipidTOX/4',6-diamidino-2-phenylindole (DAPI) separating the fatty vs. non-fatty groups. In the univariate analysis, patients with fatty rotator cuffs were aged 63.2 years on average compared with 59.7 years in the non-fatty group (P = .038). Female patients made up 57.1% of the fatty cohort, which was statistically higher than the non-fatty group (P = .042). Massive and large tears were more likely to occur in the fatty group (P = .005). In the multivariate analysis, full tendon tears had the largest predictive status of falling into the fatty group (odds ratio, 15.4; P = .008), followed by female sex (odds ratio, 4.9; P = .036). Patients in the fatty group had significantly higher American Shoulder and Elbow Surgeons scores (P = .048) and lower visual analog scale scores (P = .002). DISCUSSION AND CONCLUSION: This prospective histologic assessment revealed that full-thickness rotator cuff tears and female sex were the largest risk factors for intracellular lipid accumulation. Although tear size correlated with fatty accumulation, the sex disparity is a noteworthy finding that warrants further research.

No Difference In Clinical Outcomes Following Repair of Large Retracted Anterior Rotator Cuff Tears Using Patch Augmentation With Human Dermal Allograft Versus Anterior Cable Reconstruction With Biceps Tendon Autograft.

PURPOSE: To compare the clinical outcomes and tendon integrity after rotator cuff repair combined with anterior cable reconstruction (ACR) using the proximal biceps tendon and patch augmentation (PA) using a human dermal allograft (HDA) in a large retracted anterior rotator cuff tear. METHODS: Patients who underwent arthroscopic rotator cuff repair with 2 different augmentation procedures between January 2017 and December 2020 were enrolled. The inclusion criteria were patients who were treated by arthroscopic rotator cuff repair with ACR using the proximal biceps tendon (ACR group) or patch augmentation using a an HDA (PA group) and follow-up for at least 2 years. Clinical outcomes were assessed using American Shoulder and Elbow Surgeons (ASES) score, Constant score, and the number of patients who achieved minimal clinically important differences (MCID). Magnetic resonance imaging was performed to evaluate tendon integrity after surgery. RESULTS: A total of 92 patients were enrolled (ACR group = 55 patients and PA group = 37 patients). The mean ASES and Constant scores significantly improved in the ACR group (68.8 ± 15.3 and 58.4 ± 16.9 before surgery vs 91.4 ± 6.3 and 87.8 ± 6.0 after surgery, P < .001) and in the PA group (63.7 ± 16.7 and 57.9 ± 15.4 before surgery vs 93.1 ± 6.3 and 88.3 ± 6.2 after surgery, P < .001). Overall, 78 patients (84.8%) achieved the MCID with 81.8% in the ACR group and 89.2% in the PA group, with no significant differences between the 2 groups (P = .638). Ten patients (18.2%) had retear in the ACR group, and three patients (8.1%) had retear in the PA group (P = .174). CONCLUSIONS: In large retracted anterior rotator cuff tears, both augmentation techniques using biceps tendon autograft and HDA provided satisfactory clinical outcomes that achieved the MCID in 84.8%, range of motion restoration, and lower retear rates with no significant differences between the two groups. LEVEL OF EVIDENCE: Level III, retrospective case-control study.