Rotator Cuff Defects Research Articles

Rotator Cuff Regeneration Using a Bioabsorbable Material With Bone Marrow–Derived Mesenchymal Stem Cells in a Rabbit Model

Background: Rotator cuff regeneration using tissue engineering techniques is a challenging treatment in elderly patients with irreparable rotator cuff tears. Hypothesis: A polyglycolic acid sheet scaffold with seeded mesenchymal stem cells (MSCs) may enhance the expression of type I collagen products and increase the mechanical strength of the regenerated tendon in vivo. Study Design: Controlled laboratory study. Methods: A surgically created defect of infraspinatus tendons of rabbits was reconstructed with 2 different materials, a polyglycolic acid (PGA) sheet alone (PGA group) (n = 34) and a PGA sheet seeded with autologously cultured MSCs (MSC group) (n = 34). The authors created a tendon defect model without embedding any graft as the control model (control group) (n = 34). The rabbits were sacrificed at 4, 8, and 16 weeks after the operation and then were histologically evaluated. The rabbits were also biomechanically evaluated by measuring the ultimate failure loads and Young’s modulus at 4 and 16 weeks following implantation. Results: In the MSC group, the fibrocartilage layers and Sharpey fibers were found regularly in the insertion site at 8 weeks compared with the PGA group. In control group, thin membranes with many fibroblasts arranged in an irregular pattern linked the end of the torn cuff to the bone without any Sharpey fibers and type I collagen. A large volume of type I collagen was found in comparison with type III collagen at 16 weeks in the MSC group, whereas type III collagen was more prevalent than type I in the PGA group. The tendon maturing score in the MSC group had higher values than the PGA and control groups at 8 and 16 weeks (mean values were 21.0 ± 0.89, 24.0 ± 2.53 in the MSC group; 16.7 ± 2.25, 21.3 ± 2.42 in the PGA group; and 10.2 ± 0.98, 12.2 ± 1.72 in the control group, respectively) (P < .05). The results of the mechanical analysis revealed that the regenerated tendons in the MSC group had better tensile strength than in the PGA and control groups at 16 weeks (mean values were 3.04 ± 0.54 in the MSC group, 2.38 ± 0.63 in the PGA group, and 1.58 ± 0.13 in the control group) (P < .05). Conclusion: Bone marrow–derived MSCs were able to regenerate tendon-bone insertions and the tendon belly, including the production of type I collagen, and increased the mechanical strength of the regenerated rotator cuff tendon. Clinical Relevance: Rotator cuff regeneration using MSCs is a promising treatment for massive rotator cuff defects.

Biomechanics of Synthetic Patch Rotator Cuff Repairs

Introduction: Massive irreparable rotator cuff tears are difficult to manage. Synthetic materials have been proposed as one solution to bridge tendon defects in these tears. This study aimed to analyze the biomechanical properties of synthetic patch-bone repairs using 2 different repair configurations. Methods: An irreparable rotator cuff defect was created ex vivo in 12 ovine shoulders and then secured to a synthetic patch (2 mm Gore-Tex ePTFE, Gore, Flagstaff, AZ). The patch was then repaired to the humeral footprint with 2 suture anchors using either vertical mattress sutures (n=6) or the inverted mattress tension-band repair (n=6) technique. Footprint contact pressure was measured at 10-N, 20-N, and 30-N tension and −10, 0, and +10 degrees of abduction. Repair strength was determined using a pull-to-failure test. Results: Tension-band repairs provided significantly higher footprint contact pressure than mattress repairs in 7 out of 9 tension/abduction combinations (P<0.05). Footprint contact was maximized with decreasing abduction angle and increasing tension. Tension-band repairs had higher pullout strength (220 N ±7) than mattress repairs (188 N ±10) (P<0.03). Discussion: The tension-band repair technique of synthetic patch to bone provided better footprint contact and was stronger than mattress repairs of synthetic patch to bone. Interestingly, tendon-synthetic patch-bone repairs had higher contact pressure and pullout strength than similar tendon-bone repairs.

Application of layered poly (L-lactic acid) cell free scaffold in a rabbit rotator cuff defect model

BackgroundThis study evaluated the application of a layered cell free poly (L-lactic acid) (PLLA) scaffold to regenerate an infraspinatus tendon defect in a rabbit model. We hypothesized that PLLA scaffold without cultivated cells would lead to regeneration of tissue with mechanical properties similar to reattached infraspinatus without tendon defects.MethodsLayered PLLA fabric with a smooth surface on one side and a pile-finished surface on the other side was used. Novel form of layered PLLA scaffold was created by superimposing 2 PLLA fabrics. Defects of the infraspinatus tendon were created in 32 rabbits and the PLLA scaffolds were transplanted, four rabbits were used as normal control. Contralateral infraspinatus tendons were reattached to humeral head without scaffold implantation. Histological and mechanical evaluations were performed at 4, 8, and 16 weeks after operation.ResultsAt 4 weeks postoperatively, cell migration was observed in the interstice of the PLLA fibers. Regenerated tissue was directly connected to the bone composed mainly of type III collagen, at 16 weeks postoperatively. The ultimate failure load increased in a time-dependent manner and no statistical difference was seen between normal infraspinatus tendon and scaffold group at 8 and 16 weeks postoperatively. There were no differences between scaffold group and reattach group at each time of point. The stiffness did not improve significantly in both groups.ConclusionsA novel form of layered PLLA scaffold has the potential to induce cell migration into the scaffold and to bridge the tendon defect with mechanical properties similar to reattached infraspinatus tendon model.

Humeruskopffraktur und Manschette

During the past decade the evaluation of the rotator cuff in the management of proximal humeral fractures has received increasing attention. Different studies have investigated the pathomorphology, prevalence and impact of rotator cuff lesions on the outcome of non-operative or surgical treatment of proximal humeral fractures. Tendon defects, either chronic or trauma related, are observed mainly in the anterosuperior or posterosuperior aspect of the rotator cuff and present as partial- or full-thickness tears. Structural changes of the rotator cuff muscles including atrophy and fatty infiltration in the context of proximal humeral fractures have been inadequately investigated. The prevalence of coexisting rotator cuff pathology varies between 5 and greater than 50% depending on the method of evaluation, the fracture morphology and the age of the patient. The influence of a concomitant rotator cuff tear on the clinical outcome has not been conclusively investigated. However, different studies indicate that some lesions can be a source of persistent pain and functional deficit after conservative or surgical management of proximal humeral fractures. Therefore, a simultaneous repair of the rotator cuff defect during surgical reconstruction of the proximal humerus is indicated.

Latissimus dorsi tendon transfer for the treatment of irreparable rotator cuff defects

Latissimus dorsi tendon transfer for the treatment of irreparable rotator cuff defects

Rotator Cuff Defect: Acute or Chronic?

THE PATIENT A 63-year-old, right hand–dominant man presents with a 3-week history of right shoulder pain after trying to catch a suitcase falling out of an overhead bin on an airplane. He has had no antecedent pain or weakness and no history of prior shoulder injury. Examination demonstrates pain limiting active and forward flexion to 140°, internal rotation to the buttock, and external rotation to 50°. The patient has positive Neer and Hawkins impingement tests. External rotation strength is preserved and there is no external rotation lag. He has no cervical radicular symptoms, and minimal biceps and acromioclavicular joint symptoms. After injection of lidocaine into the subacromial space, the patient is able to forward flex the shoulder to 170°, internally rotate to T10, and externally rotate to 70°, which is symmetric with the opposite arm. Magnetic resonance imaging ordered by his primary care doctor demonstrates a full-thickness tear of the supraspinatus tendon, 10 mm in anteroposterior dimension with 5 mm of retraction.

Single versus double-row repair of the rotator cuff

Several techniques for arthroscopic repair of rotator cuff defects have been introduced over the past years. Besides established techniques such as single-row repairs, new techniques such as double-row reconstructions have gained increasing interest. The present article therefore provides an overview of the currently available literature on both repair techniques with respect to several anatomical, biomechanical, clinical and structural endpoints. Systematic literature review of biomechanical, clinical and radiographic studies investigating or comparing single- and double-row techniques. These results were evaluated and compared to provide an overview on benefits and drawbacks of the respective repair type. Reconstructions of the tendon-to-bone unit for full-thickness tears in either single- or double-row technique differ with respect to several endpoints. Double-row repair techniques provide more anatomical reconstructions of the footprint and superior initial biomechanical characteristics when compared to single-row repair. With regard to clinical results, no significant differences were found while radiological data suggest a better structural tendon integrity following double-row fixation. Presently published clinical studies cannot emphasize a clearly superior technique at this time. Available biomechanical studies are in favour of double-row repair. Radiographic studies suggest a beneficial effect of double-row reconstruction on structural integrity of the reattached tendon or reduced recurrent defect rates, respectively.

Early Results of Concurrent Arthroscopic Repair of Rotator Cuff and Type II Superior Labral Anterior Posterior Tears

Background:Recent reports on concurrent arthroscopic rotator cuff and type II superior labral anterior posterior (SLAP) repair have raised concerns over postoperative stiffness and patient satisfaction. However, it is unclear if the observed stiffness relates to the repair of degenerative SLAP tears in older adults, the surgical technique, the postoperative rehabilitation, or to a combination of these factors.Purpose:The purpose of this study was to evaluate the outcome and repair integrity of concurrent arthroscopic rotator cuff and type II SLAP repair.Study Design:Case series.Methods:Of 11 patients identified, 7 had a full-thickness rotator cuff tear and 4 had a high-grade partial thickness tear that was completed. A cannula placed through the rotator cuff tear improved the trajectory for posterior suture anchor placement during SLAP repair. Postoperative rehabilitation employed continuous passive motion to prevent stiffness.Results:At minimum of 1-year follow-up, mean yes responses on the Simple Shoulder Test improved from 5.4 to 10.7 (out of 12; P < .01), and mean American Shoulder and Elbow Surgeons scores improved from 40 to 87 (out of 100; P < .01). Mean forward elevation improved from 148° to 161° (P < .01) and external rotation from 58° to 67° (P < .01). Magnetic resonance imaging, obtained at most recent follow-up in 10 patients, demonstrated a healed SLAP tear in all patients and a persistent rotator cuff defect in 1 patient.Conclusions:Arthroscopic rotator cuff repair can be successfully combined with type II SLAP repair in relatively young patients who have sustained traumatic injury to their shoulders. Allowing early passive motion may help prevent postoperative stiffness without compromising rotator cuff healing.

Characteristics of donor and host cells in the early remodeling process after transplant of Achilles tendon with and without live cells for the treatment of rotator cuff defect -what is the ideal graft for the treatment of massive rotator cuff defects?

We examined the characteristics of donor and host cells in the early remodeling process after transplant of Achilles tendon with and without live cells to repair rotator cuff defects. We also clarified which graft with or without live cells was superior in the early remodeling process. Sprague-Dawley (SD) rats and green fluorescent protein (GFP) rats were used; they were divided into 3 groups: in group SD, the Achilles tendons of GFP rats were transplanted into the defects of SD rats; in group GFP, the Achilles tendons of SD rats were transplanted into GFP rats; in group GFP-Fr, frozen Achilles tendons of SD rats were transplanted into GFP rats. At 3 and 7 days after surgery, these sections were examined histologically and immunohistochemically with anti-heat shock protein (HSP) 47 and anti-macrophage antibodies. Donor cells gradually decreased, but HSP47-positive donor cells were detected at 3 days in group SD. Host cells infiltrated into the graft from the surrounding tissue, and their numbers in groups SD and GFP gradually increased more significantly than in group GFP-Fr. Macrophages derived from the donor tissue were absent in all groups. The remodeling process of the frozen graft was slower than that in the case of the graft that was not frozen. These results demonstrate that live donor cells have a positive effect on the remodeling process. Therefore, autografts with live cells considered to be preferred to frozen allografts or synthetic materials without live cells for transplant for rotator cuff defects.

Positive Alizarin Red Clumps in Milwaukee Shoulder Syndrome

To the Editor: Milwaukee shoulder syndrome is a destructive, basic calcium phosphate crystalline arthropathy characterized by pain, large-joint effusion, and loss of function in the affected joint1. It classically affects those over 70 years of age, 90% of whom are female. The syndrome is often associated with rotator cuff defects, and the effusion is noninflammatory with numerous aggregates of calcium hydroxyapatite crystals in the synovial fluid. Identifying individual calcium hydroxyapatite crystals in synovial fluid can be elusive, since these crystals are not identified under plain and polarized microscopy, unlike monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystals. However, globular clumps of hydroxyapatite crystals may appear using plain light microscopy, but they are not birefringent. Such clumps have been described as “shiny coins,” although often they either are … Address correspondence to Dr. C.J. Forster; E-mail: christopher.forster{at}us.army.mil

Deltoid muscular flap transfer for the treatment of irreparable rotator cuff tears

The purpose of this study was to evaluate the outcome of deltoid muscle flap transfer for the treatment of irreparable rotator cuff tears. In a retrospective study 20 consecutive patients were evaluated. The index procedure took place between 2000 and 2003. Fifteen patients were male, mean age was 62 years. Inclusion criterion was a rotator cuff defect Bateman grade IV. Exclusion criteria were smaller defects, shoulder instability and fractures of the injured shoulder. An open reconstruction with acromioplasty and a pedicled delta flap was performed. Follow up period was mean 42 months. Follow-up included clinical examination, Magnetic Resonance Imaging (MRI) and the Constant and Simple (CS) shoulder tests. According to the Constant shoulder test the results were good in 13 patients, fair in 5 and unsatisfactory in 2. The pre-operative Constant Score improved from mean 25.7 points (±5.3) to 72.3 (±7.8) at follow-up. The mean values for the subcategories of CS increased significantly from 3.9 to 14.4 points for pain and from 4.2 to 15.9 points for activities daily routine (p<0.05). The change in range of motion and strength were not significant (p>0.05). Results of the Simple Shoulder Test showed a significant increase of the mean values from pre-operative 4.3 to 14.7 points post-operatively. MRI showed a subacromial covering of the defect in all cases, all flaps where intact on MRI but always the flap showed marked fatty degeneration. In conclusion, the delta flap is a simple method for the repair of large defects of the rotator cuff leading to satisfying medium results.

The Long-Term Outcome of Recurrent Defects after Rotator Cuff Repair

Background Retears of the rotator cuff are not uncommon after arthroscopic and mini-open rotator cuff repairs. In most studies, the clinical results in patients with persistent defects demonstrated significantly less pain and better function and strength compared with their preoperative state at an early follow-up. Hypothesis The clinical and structural outcomes of patients with known rotator cuff defects will remain unchanged after a longer period of follow-up. Study Design Case series; Level of evidence, 4. Methods This study was performed in 15 patients (18 shoulders) from a previous study who had recurrent rotator cuff defects 3.2 years after repair. Each patient completed the American Shoulder and Elbow Surgeons Scoring Survey, the Simple Shoulder Test, the L'Insalata Scoring Survey, and a visual analog scale for pain. Eleven patients (13 shoulders) were clinically reexamined at an average of 7.9 years for range of motion and strength, with targeted ultrasound. Results At the 7.9 year follow-up the average scores were 95 (American Shoulder and Elbow Surgeons), 95 (L'Insalata), 11 (Simple Shoulder Test), and 0 (visual analog for pain), which were not statistically significantly different from the scores at 3.2 years. There was no change in the average range of motion; however, there was a statistically significant reduction in forward flexion strength and external rotation strength, as measured by a dynamometer. The average external rotation strength decreased by a mean of 42% and the mean forward flexion strength decreased by a mean of 45% (P < .001). Furthermore, there was a statistically significant increase in the mean size of the defect, from 273 mm2 to 467 mm2 (P < .001). Finally, the size of the defect increased in all patients, and no defects healed structurally. Conclusion At an average of 7.9 years, patients with recurrent defects after rotator cuff repair still had an improvement in terms of pain, function, and satisfaction. However, the rotator cuff defect significantly increased in size, and there was a progression of strength deficits. These findings suggest that patients with recurrent defects can remain asymptomatic over the long term but will predictably lose strength in the involved extremity. Furthermore, the study demonstrated that defects after rotator cuff repair increase in size but often remain asymptomatic.

Modified minimally invasive latissimus dorsi transfer in the treatment of massive rotator cuff tears: a two-year follow-up of 26 consecutive patients

Since its inauguration by Gerber in 1988, the latissimus dorsi transfer has become an established surgical option for non-reconstructable, massive posterosuperior rotator cuff tears. We describe 26 consecutive patients, all of whom underwent a latissimus dorsi transfer using a modified single incision mini-invasive Herzberg transfer. The primary focus of this paper was to compare the applied clinical results of this new technique with the published results of the Gerber technique. Following transfer of the latissimus dorsi to restore external rotation, 26 patients were evaluated. The mean age was 60 +/- 18 years. The patients were examined after surgery at an average of 24 months (range: 12-41). The unweighted Constant score rose from 20 (range: 13-34) to 56 (range: 63-81). The acromiohumeral distance remained statistically unchanged from an initial value of 4.7 mm (1-9 mm) to a postoperative value of 4.8 (2-11 mm). In the Hamada classification the level of rotator cuff defect arthropathy increased from 1.7 (1-3) to 1.8 (1-3). On the basis of its low morbidity rate, the latissimus dorsi transfer in Herzberg's modified technique is a sensible alternative to the technique initially described by Gerber, especially when the initial situation exhibits pre-existing weakness of the deltoid muscle.

A symptom-based classification for shoulders with massive rotator cuff defects

The aim of this prospective study was to propose a classification for shoulders with massive rotator cuff defects based on patients' clinical symptoms. A total of 100 shoulders with massive rotator cuff tears were evaluated clinically using the Constant score (CS) and with radiographs in two planes. Three types were defined and correlated with radiographic findings: (1) the arthritic type (type I), (2) the non-reactive type (type II) and (3) the necrotic type (type III). Significant differences in the overall CS (type I: 28.6 points, range: 4 - 61; type II: 18.8 points, range: 6 - 52; type III: 15.5 points, range: 6 - 31) and its subgroups and in shoulder motion were found between types I and II and between types I and III (p < 0.05). This classification may be helpful for the decision-making process with regard to the appropriate form of shoulder replacement surgery in patients with massive rotator cuff defects.

The Role of Donor and Host Cells after Transplantation of Achilles Tendon with and without Live Cells for Rotator Cuff Defects

The Role of Donor and Host Cells after Transplantation of Achilles Tendon with and without Live Cells for Rotator Cuff Defects

The Effect of Anterosuperior Rotator Cuff Tears on Glenohumeral Translation

The purpose of this study was to sequentially investigate the biomechanical effects of anterosuperior rotator cuff tear size on superior and anterosuperior translation, including tears interrupting the anterior cable attachment and the anterior force couple. Five cadaveric shoulders were subjected to different loading conditions in both the superior and anterosuperior directions in the intact state, with the supraspinatus cut and with sequentially larger anterosuperior rotator cuff tears. Isolated tears of the supraspinatus had no significant biomechanical consequences under any condition tested. Anterosuperior translation was greater than superior translation in the intact specimen and for every combination of anterosuperior rotator cuff defect. With the supraspinatus and the superior half of the subscapularis (i.e., the anterior cable attachment) released, there was no significant increase in anterosuperior or superior glenohumeral translation in response to lower loading conditions (10 to 20 N). At higher loading conditions (40 to 50 N), tears of the supraspinatus and superior half of the subscapularis led to significantly increased translation in both directions. Simulated anterosuperior rotator cuff tears involving the superior half of the subscapularis significantly alter shoulder biomechanics and lead to increased anterosuperior and superior glenohumeral translation under higher loads. The anterior attachment of the rotator cuff cable is therefore an important determinant of the biomechanics of anterosuperior rotator cuff tears at higher loads but not at lower loads. Preserving the inferior half of the subscapularis was sufficient to maintain relatively normal shoulder kinematics under lower loading conditions. Tears of the entire subscapularis altered glenohumeral kinematics at essentially all loads. Knowledge of the biomechanics of anterosuperior rotator cuff tears enhances our understanding of how to best treat these lesions.

Reconstruction of large rotator-cuff tears with acellular dermal matrix grafts in rats

With the acellular dermal matrix (ADM), it may be possible to bridge large rotator cuff tears and induce tendon regeneration. A 3 x 5 mm defect of the rotator cuff was created on both shoulders of adult male Sprague-Dawley rats. The graft group (n = 15) underwent reconstruction of the rotator cuff defect with an ADM patch graft; in the defect group (n = 15) no repair was performed. We sacrificed 5 rats from each group at 2, 6, and 12 weeks after surgery and harvested both shoulders; 3 specimens were subjected to histological analysis and the other 7 specimens were used for biomechanical testing. The controls were 5 unoperated rats; they were sacrificed to obtain 3 histologic and 7 biomechanical control shoulder specimens. At each time points, the graft group had significantly higher modified tendon maturing scores than the defect group (p < 0.002); specimens from the graft group demonstrated a greater mean ultimate force to failure than those from the defect group (p < 0.05). Within 12 weeks, the ADM graft was histologically incorporated into a structure resembling control specimen; the mean ultimate force to failure in control was significantly greater than in specimens from both groups (p < 0.01). Although the defect was restored in the defect group, histologically and biomechanically specimens from the defect group were inferior to the graft group. ADM grafts were useful as a scaffold in the reconstruction of large rotator cuff defects in rats. Basic science study.

GFP ラット腱板断裂モデルを用いた腱移植後早期の再構築 （移植腱細胞の有無による比較）

GFP ラット腱板断裂モデルを用いた腱移植後早期の再構築 （移植腱細胞の有無による比較）

Rheumatoid shoulder: Does minimally invasive therapy make sense?

Surgical treatment of patients with rheumatoid arthritis of the shoulder should be one part of a concept of conservative and surgical treatment. In addition to disease-modifying agents, local minimally invasive surgery can avoid structural damage to the shoulder and furthermore achieve a restitution of shoulder function. According to Larsen Stage 0-III, an arthroscopic synovectomy and bursectomy can achieve a good prognosis and help to avoid further structural damage to the rheumatoid shoulder. Minimally invasive procedures in the surgery of the rheumatoid shoulder lead to less immobilisation and faster rehabilitation, to the benefit of the joints in the operated limb, much like therapy of the knee. It is also possible to treat associated pathologies with minimally invasive surgery, such as bursitis, small rotator cuff defects, and synovitis of the acromioclavicular joint, as well as synovectomy of the glenohumeral joint Good results can be achieved in these cases using minimally invasive surgery. However, minimally invasive reconstructive procedures are limited in the rheumatoid shoulder.

The use of split deltoid-flap in the treatment of massive rotator cuff defects: a retrospective study of 61 patients

Massive and irreparable rotator cuff tears are a challenge for the orthopaedic surgeon. The purpose of this study was to report our experience with the treatment of massive and irreparable defects of the rotator cuff with a modified deltoid split transfer. Between 1996 and 2004, for all patients suffering from full-thickness tears of the rotator cuff (> 5 cm tears in diameter, involving two or more tendons) were operated with a modified deltoid split transfer. A total of 61 patients (39 females and 22 males; age 61.9: range 49-75 years) were operated. Duration of symptoms before surgery averaged 9.6 months (range 3.5-14 months). The patients were followed for an average of 46 months (range 24-64 months). The operation included an arthroscopic evaluation, acromioplasty with resection of the lateral clavicular end, resection of the acromioclavicular joint and where necessary biceps tenodesis. The cuff defect was repaired by transfer of half thickness anterior deltoid-flap (3 cm x 5 cm) into the defect. All patients were evaluated both preoperatively and postoperatively with regard to pain, ability to perform activities of daily life, range of motion, strength and satisfaction. The patients subjectively rated their results--49 (80%) excellent or good outcome, seven moderate and five poor. Preoperatively, the Constant amounted 33.5 +/- 7.74 points. At follow-up, the score significantly increased to 77.57 +/- 19.74 points. The acromiohumeral distance increased from 5.1 +/- 1.4 mm to 9.1 +/- 1.5 mm. Pain free flexion improved from an average 90 degrees to an average 165 degrees (P < 0.01), and abduction improved from an average 110 degrees to an average 160 degrees (P < 0.01). The mean external rotation increased from 40 degrees to 65 degrees (P < 0.01), and internal rotation increased from 50 degrees to 70 degrees (P = 0.06). In the MRI and ultrasound examination, all patients had intact flap, except the three patients with flap necrosis. There were eight complications--three haematomas, two superficial wound infections which did not influence the outcome, and three fibrotic transformation after an early aseptic necrosis of the deltoid flap, which were re-operated. This technique is easy to perform, and it is possible to obtain a satisfactory outcome after repair of massive tears of the rotator cuff. A substantial decrease of pain, increased stability, an increase range of motion and strength can be achieved, with proper rehabilitation.