Chronic Cuff Research Articles

Translated article] Efficacy of transplantation of lipoaspired mesenchymal stem cells in the treatment of chronic rotator cuff tears. Experimental model in rats

Background and aimRotator cuff tears emerge in approximately 30% of the population over 60 years of age. Arthroscopic surgical treatment of these lesions is the treatment of choice, however, despite the improved repair techniques, the rate of re-tears ranges between 11 and 94%. Therefore, researchers seek to improve the biological healing process through the use of different alternatives such as mesenchymal stem cells (MSCs). Our objective is to evaluate the efficacy of a cellular therapy drug made from allogeneic stem cells derived from adipose tissue in a rat model of chronic rotator cuff injury. Material and methodsThe supraspinatus lesion was created in 48 rats for subsequent suturing at 4 weeks. MSCs in suspension were added to 24 animals after suturing, and HypoThermosol-FRS® (HTS) to 24 animals as a control group. Histology (Åström and Rausing scale) and the maximum load, displacement and elastic constant of the supraspinatus tendon were analysed in both groups 4 months after the repair. ResultsNo statistically significant differences were found in the histological score comparing the tendons treated with MSCs with respect to the tendons treated with HTS (P=0.811) nor in the results of maximum load (P=0.770), displacement (P=0.852) or elastic constant (P=0.669) of the tendon in both groups. ConclusionsThe addition of adipose-derived cells in suspension to the repair of a chronic cuff injury does not improve the histology or biomechanics of the sutured tendon.

Eficacia del trasplante de células madre mesenquimales de lipoaspirado en el tratamiento de lesiones crónicas del manguito rotador. Modelo experimental en ratas

Background and aimRotator cuff tears emerge in approximately 30% of the population over 60 years of age. Arthroscopic surgical treatment of these lesions is the treatment of choice, however, despite the improved repair techniques, the rate of re-tears ranges between 11 and 94%. Therefore, researchers seek to improve the biological healing process through the use of different alternatives such as mesenchymal stem cells (MSCs). Our objective is to evaluate the efficacy of a Cellular Therapy Drug made from allogeneic stem cells derived from adipose tissue in a rat model of chronic rotator cuff injury. Material and methodsThe supraspinatus lesion was created in 48 rats for subsequent suturing at 4 weeks. MSCs in suspension were added to 24 animals after suturing, and HypoThermosol-FRS® (HTS) to 24 animals as a control group. Histology (Åström and Rausing scale) and the maximum load, displacement and elastic constant of the supraspinatus tendon were analyzed in both groups 4 months after the repair. ResultsNo statistically significant differences were found in the histological score comparing the tendons treated with MSCs with respect to the tendons treated with HTS (P=.811) nor in the results of maximum load (P=.770), displacement (P=.852) or elastic constant (P=.669) of the tendon in both groups. ConclusionsThe addition of adipose-derived cells in suspension to the repair of a chronic cuff injury does not improve the histology or biomechanics of the sutured tendon.

Selective Facial Muscle Activation with Acute and Chronic Multichannel Cuff Electrode Implantation in a Feline Model.

Facial paralysis is a debilitating condition with substantial functional and psychological consequences. This feline-model study evaluates whether facial muscles can be selectively activated in acute and chronic implantation of 16-channel multichannel cuff electrodes (MCE). Two cats underwent acute terminal MCE implantation experiments, 2 underwent chronic MCE implantation in uninjured facial nerves (FN) and tested for 6 months, and 2 underwent chronic MCE implantation experiments after FN transection injury and tested for 3 months. The MCE were wrapped around the main trunk of the skeletonized FN, and data collection consisted of EMG thresholds, amplitudes, and selectivity of muscle activation. In acute experimentation, activation of specific channels (ie, channels 1-3 and 6-8) resulted in selective activation of orbicularis oculi, whereas activation of other channels (ie, channels 4, 5, or 8) led to selective activation of levator auris longus with higher EMG amplitudes. MCE implantation yielded stable and selective facial muscle activation EMG thresholds and amplitudes up to a 5-month period. Modest selective muscle activation was furthermore obtained after a complete transection-reapproximating nerve injury after a 3-month recovery period and implantation reoperation. Chronic implantation of MCE did not lead to fibrosis on histology. Field steering was achieved to activate distinct facial muscles by sending simultaneous subthreshold currents to multiple channels, thus theoretically protecting against nerve damage from chronic electrical stimulation. Our proof-of-concept results show the ability of an MCE, supplemented with field steering, to provide a degree of selective facial muscle stimulation in a feline model, even following nerve regeneration after FN injury. N/A.

The Effect of Tendon Delamination on Rotator Cuff Healing

Background: While patient age, tear size, and muscle fatty infiltration are factors known to affect the rate of tendon healing after rotator cuff repair, the effect of tendon delamination is less known. Purpose: To assess the effect of tendon delamination on rotator cuff healing after arthroscopic single-row (SR) repair. Study Design: Cohort study; Level of evidence, 3. Methods: Consecutive patients (N = 117) with chronic full-thickness rotator cuff tears underwent arthroscopic SR repair with the tension-band cuff repair. The mean ± SD age at the time of surgery was 60 ± 8 years. There were 25 small, 63 medium, and 29 large tears. Tendon delamination was assessed intraoperatively under arthroscopy with the arthroscope placed in the lateral portal. Patients were divided into 2 groups: those with nondelaminated (n = 80) and delaminated (n = 37) cuff tears. The 2 groups were comparable for age, sex, body mass index, preoperative pain, strength, and a Constant-Murley score. Repair integrity was evaluated with sonography (mean, 24 months after surgery; range, 6-62 months) and classified into 3 categories: type A, indicating complete, homogeneous, and thick coverage of the footprint; type B, partial coverage with a thin tendon; and type C, no coverage of the footprint. Results: The prevalence of tendon delamination observed under arthroscopy was 32% (37 of 117), which increased with tear size and retraction: from 15% in small tears to 32% in medium tears and 45% in large tears (P = .028). Postoperatively, 83 patients had complete coverage of footprint (type A = 71%) and the cuff was considered healed, whereas 26 had partial coverage or a thin tendon (type B = 22%) and 8 had no coverage (type C = 7%). Overall, the rate of complete healing was 78% in nondelaminated cuff tears and 57% in the case of tendon delamination (P = .029). In large retracted tears, the healing rate dropped from 81% in the absence of delamination to 39% when the tendons were delaminated (P = .027). Conclusion: Tendon delamination increases with tear size and retraction. Patients with chronic delaminated and retracted rotator cuff tears (stage 2 or 3) are at risk of failure after SR cuff repair, whereas patients with small delaminated rotator cuff tears (stage 1) involving only the supraspinatus can be treated with an SR cuff repair with a high chance of tendon healing. These results suggest that SR cuff repair may be insufficient to treat delaminated chronic cuff tears. To improve the anatomic outcomes of rotator cuff repairs, surgeons should consider treating delaminated tears with a double-row or double-layer repair.

Arthroscopic repair of glenoid rim fractures: a ligamentotaxis surgical technique.

Glenoid fractures occur as a result of direct impact of the humeral head against the glenoid rim following high-energy trauma. They frequently involve one-third of the glenoid surface with an oblique fracture rim from 2 to 6-7 o'clock, and they must not be confused with bony Bankart lesions. In medium-age patients, they are frequently associated with acute cuff tear while in older patients with chronic cuff tear: These conditions increase the instability of the shoulder if not treated. With this study, we reported the results of the arthroscopic ligamentotaxis technique treatment of acute antero-inferior glenoid fractures type IA of Ideberg with a cuff repair associated. Eleven patients with IA Ideberg glenoid fracture were treated with ligamentotaxis technique. Mean age: 56years (45-70); 80% dominant side; male/female: 1.2. Mean extension area of glenoid fracture: 25%. The fragment was fixated reinserting the labro-ligamentous complex with a single 2o'clock anchor. In six patients (55%), a rotator cuff tear was present, repaired during the surgical intervention. Radiological assessment: X-rays and CT with PICO method to measure the glenoid area involved. Clinical assessment: VAS, constant score, Dash score and Rowe score. After 30months of follow-up (12-50), no differences in flexion, abduction, rotations and pain were reported compared to the contralateral side (p > 0.05). The mean normalized constant was 101 (60-123), and the mean Rowe was 93 (65-100). X-rays showed good healing without articular surface depressions or step in all cases. Two patients had a progression of gleno-humeral arthritis. Acute antero-inferior glenoid rim fractures are uncommon but they are increasing in over 55years population (frequently associated with cuff tear). Correct classification and treatment are necessary to achieve good results. The X-ray assessment includes the Neer's trauma series and the CT study with PICO measurement of glenoid fragment size. Wrong treatment can lead to chronic instability, degenerative joint disease and poor results. The arthroscopic repair with ligamentotaxis is a good solution and permits the treatment of the associated rotator cuff tear. Arthroscopic technique imposes a long learning curve. CT can be used to confirm the anatomic reduction and the healing of the fracture but since it uses X-rays it must be reserved to comminuted fractures.

Inhibition of prolyl 4-hydroxylase decreases muscle fibrosis following chronic rotator cuff tear

ObjectivesRotator cuff tears are among the most frequent upper extremity injuries. Current treatment strategies do not address the poor quality of the muscle and tendon following chronic rotator cuff tears. Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor that activates many genes that are important in skeletal muscle regeneration. HIF-1α is inhibited under normal physiological conditions by the HIF prolyl 4-hydroxylases (PHDs). In this study, we used a pharmacological PHD inhibitor, GSK1120360A, to enhance the activity of HIF-1α following the repair of a chronic cuff tear, and measured muscle fibre contractility, fibrosis, gene expression, and enthesis mechanics.MethodsChronic supraspinatus tears were induced in adult rats, and repaired 28 days later. Rats received 0 mg/kg, 3 mg/kg, or 10 mg/kg GSK1120360A daily. Collagen content, contractility, fibre type distribution and size, the expression of genes involved in fibrosis, lipid accumulation, atrophy and inflammation, and the mechanical properties of the enthesis were then assessed two weeks following surgical repair.ResultsAt two weeks following repair, treatment groups showed increased muscle mass but there was a 15% decrease in force production in the 10 mg/kg group from controls, and no difference between the 0 mg/kg and the 3 mg/kg groups. There was a decrease in the expression of several gene transcripts related to matrix accumulation and fibrosis, and a 50% decrease in collagen content in both treated groups compared with controls. Additionally, the expression of inflammatory genes was reduced in the treated groups compared with controls. Finally, PHD inhibition improved the maximum stress and displacement to failure in repaired tendons.ConclusionsGSK1120360A resulted in improved enthesis mechanics with variable effects on muscle function. PHD inhibition may be beneficial for connective tissue injuries in which muscle atrophy has not occurred.Cite this article: J. P. Gumucio, M. D. Flood, A. Bedi, H. F. Kramer, A. J. Russell, C. L. Mendias. Inhibition of prolyl 4-hydroxylase decreases muscle fibrosis following chronic rotator cuff tear. Bone Joint Res 2017;6:57–65. DOI: 10.1302/2046-3758.61.BJR-2016-0232.R1.

Botulinum toxin is detrimental to repair of a chronic rotator cuff tear in a rabbit model.

Re-tear continues to be a problem after rotator cuff repair. Intramuscular botulinum toxin (Botox) injection can help optimize tension at the repair site to promote healing but could have an adverse effect on the degenerated muscle in a chronic tear. We hypothesized that Botox injection would improve repair characteristics without adverse effect on the muscle in a chronic rotator cuff tear model. The supraspinatus tendon of both shoulders in 14 rabbits underwent delayed repair 12 weeks after transection. One shoulder was treated with intramuscular Botox injection and the other with a saline control injection. Six weeks after repair, outcomes were based on biomechanics, histology, and magnetic resonance imaging. Botox-treated repairs were significantly weaker (2.64 N) than control repairs (5.51 N, p = 0.03). Eighty percent of Botox-treated repairs and 40% of control repairs healed with some partial defect. Fatty infiltration of the supraspinatus was present in all shoulders (Goutallier Grade 3 or 4) but was increased in the setting of Botox. This study provides additional support for the rabbit supraspinatus model of chronic cuff tear, showing consistent fatty infiltration. Contrary to our hypothesis, Botox had a negative effect on repair strength and might increase fatty infiltration.

The role of tendon and subacromial bursa in rotator cuff tear pain: a clinical and histopathological study.

To evaluate a possible association of shoulder pain with the clinical features and the histopathological changes occurring in the ruptured tendon and subacromial bursa of patients with rotator cuff tear. One hundred and eighty patients were clinically evaluated with the constant score and the visual analogue pain scale. Radiographs and MRI were performed. The chronology of the rupture, the muscle fatty degeneration according to Goutallier's scale and the tear size were evaluated. For each patient, a biopsy of the supraspinatus tendon and subacromial bursa was performed during arthroscopic rotator cuff tear repair and the specimens were histopathologically analysed. Clinically, the shoulder was more painful in females, in the presence of a chronic cuff lesion and a low Goutallier's grade (P<0.05). No association was found between pain and age of the patient and between pain and tear size. Histologically, hypertrophy and inflammation of the tendon and hypertrophy, inflammation, oedema and necrosis of the subacromial bursa were directly associated with pain (P<0.05). Pain decreased significantly in the presence of fatty metaplasia and necrosis of the tendon (P<0.05). This study defines the main clinical and histopathological features of painful rotator cuff tear. In particular, a greater association of pain was observed with the histopathological changes in the bursa compared with those in the rotator cuff. Considering that the bursa plays also an essential role during the healing process, this "new" role of the subacromial bursa as pain generator has important repercussions in both pharmacological and surgical treatments of rotator cuff tears. IV.

Simvastatin reduces fibrosis and protects against muscle weakness after massive rotator cuff tear

Chronic rotator cuff tears are a common source of shoulder pain and disability, and patients with chronic cuff tears often have substantial weakness, fibrosis, inflammation, and fat accumulation. Identifying therapies to prevent the development of these pathologic processes will likely have a positive impact on clinical outcomes. Simvastatin is a drug with demonstrated anti-inflammatory and antifibrotic effects in many tissues but had not previously been studied in the context of rotator cuff tears. We hypothesized that after the induction of a massive supraspinatus tear, simvastatin would protect muscles from a loss of force production and fibrosis. We measured changes in muscle fiber contractility, histology, and biochemical markers of fibrosis and fatty infiltration in rats that received a full-thickness supraspinatus tear and were treated with either carrier alone or simvastatin. Compared with vehicle-treated controls, simvastatin did not have an appreciable effect on muscle fiber size, but treatment did increase muscle fiber specific force by 20%. Simvastatin also reduced collagen accumulation by 50% but did not affect triglyceride content of muscles. Several favorable changes in the expression of genes and other markers of inflammation, fibrosis, and regeneration were also observed. Simvastatin partially protected muscles from the weakness that occurs as a result of chronic rotator cuff tear. Fibrosis was also markedly reduced in simvastatin-treated animals. Whereas further studies are necessary, statin medication could potentially help improve outcomes for patients with rotator cuff tears.

T lymphocytes are not required for the development of fatty degeneration after rotator cuff tear.

Objectives Rotator cuff tears are among the most common and debilitating upper extremity injuries. Chronic cuff tears result in atrophy and an infiltration of fat into the muscle, a condition commonly referred to as ‘fatty degeneration’. While stem cell therapies hold promise for the treatment of cuff tears, a suitable immunodeficient animal model that could be used to study human or other xenograft-based therapies for the treatment of rotator cuff injuries had not previously been identified.Methods A full-thickness, massive supraspinatus and infraspinatus tear was induced in adult T-cell deficient rats. We hypothesised that, compared with controls, 28 days after inducing a tear we would observe a decrease in muscle force production, an accumulation of type IIB fibres, and an upregulation in the expression of genes involved with muscle atrophy, fibrosis and inflammation.Results Chronic cuff tears in nude rats resulted in a 30% to 40% decrease in muscle mass, a 23% reduction in production of muscle force, and an induction of genes that regulate atrophy, fibrosis, lipid accumulation, inflammation and macrophage recruitment. Marked large lipid droplet accumulation was also present.Conclusions The extent of degenerative changes in nude rats was similar to what was observed in T-cell competent rats. T cells may not play an important role in regulating muscle degeneration following chronic muscle unloading. The general similarities between nude and T-cell competent rats suggest the nude rat is likely an appropriate preclinical model for the study of xenografts that have the potential to enhance the treatment of chronically torn rotator cuff muscles.Cite this article: Bone Joint Res 2014;3:262–72.

Muscle Injury Induced At the Time of Acute and Chronic Rotator Cuff Repair

Objectives:Rotator cuff tears are a common source of shoulder pain and disability. Even after surgical repair of these tears, many patients continue to have reduced shoulder function and a progression of intramuscular fatty degeneration. Previous work in a sheep model demonstrated that a slow, progressive lengthening of chronically torn cuff muscles followed by surgical repair of the tendon reversed fatty degeneration and improved muscle function. As patients with chronic cuff tears often experience a shortening of the muscle fibers, it is possible that repairing the torn tendon to its original anatomical footprint induces a massive stretch-induced muscle injury that could contribute to poor outcomes after repair. Evans Blue Dye (EBD) is a water soluble, membrane impermeable dye, that is used to identify muscle fibers that have suffered an injury to their plasma membrane. We hypothesized that, compared with acutely torn and repaired rotator cuff muscles, the substantial stretch that is required to repair a chronically torn and shortened rotator cuff would result in significant muscle fiber damage.Methods:This study was approved by our IACUC. Male Sprague-Dawley retired breeder rats (n=30) were placed into 5 groups: control, sham surgery, acute tear no repair, acute tear and repair, chronic tear no repair and chronic tear and repair, with each modality performed bilaterally (Fig 1A). An intraperitoneal injection of 1% EBD was administered 24 hours before the harvest surgery. At harvest, the supraspinatus muscles of each rat were removed and the length and mass of each muscle was measured. To determine EBD+ fibers the supraspinatus muscles were snap frozen in OCT and the muscles were cryosectioned and incubated with WGA-Lectin-AF488 to mark the extracellular matrix (ECM), DAPI to identify nuclei and EBD was used to identify the fibers with a damaged sarcolemma (Fig 1B-C). A one-way ANOVA (p<0.05) and Tukey’s post-hoc sorting was used to evaluate the differences between groups.Results:Compared with controls, rats that had a chronic supraspinatus tear but did not undergo repair had a 35% decrease in muscle mass compared to controls, while rats that had a chronic tear and also underwent repair had a 24% decrease in wet mass compared to controls (Fig 1D). Both groups of rats that underwent a chronic tear experienced an approximate 20% decrease in supraspinatus length when compared to the muscle length of other groups (Fig 1E). In the sham, acute and chronic tear and repair groups there were a greater number of EBD+ fibers in the mid-distal region of the muscle than in the mid-proximal region (Fig 1F). At the mid-distal end of the control and chronic tear no repair groups there were very few EBD+ fibers, in the sham 27% of the fibers were EBD+ and the remaining groups had almost 90% EBD+ fibers (Fig 1F). At the mid-proximal portion of the muscle the chronic tear and repair group had nearly 70% EBD+ fibers while none of the other groups showed a significant increase in EBD+ fibers over the control group (Fig 1G).Conclusion:A massive injury to muscle fibers is induced when the tendons of chronically torn rotator cuffs are repaired to their anatomical footprint. The repair of chronically torn cuff muscles results in extensive injury throughout the muscle that may contribute to poor long-term surgical outcomes even in the setting of a structurally intact repair. Therapeutic interventions that protect the muscle fiber plasma membrane may improve outcomes in patients with rotator cuff tears.

Aging-associated exacerbation in fatty degeneration and infiltration after rotator cuff tear

Rotator cuff tears are one of the most common musculoskeletal complaints and a substantial source of morbidity in elderly patients. Chronic cuff tears are associated with muscle atrophy and an infiltration of fat to the area, a condition known as "fatty degeneration." To improve the treatment of cuff tears in elderly patients, a greater understanding of the changes in the contractile properties of muscle fibers and the molecular regulation of fatty degeneration is essential. Using a full-thickness, massive supraspinatus and infraspinatus tear model in elderly rats, we measured fiber contractility and determined changes in fiber type distribution that develop 30 days after tear. We also measured the expression of messenger RNA and micro-RNA transcripts involved in muscle atrophy, lipid accumulation, and matrix synthesis. We hypothesized that a decrease in specific force of muscle fibers, an accumulation of type IIb fibers, and an upregulation in atrophic, fibrogenic, and inflammatory gene expression would occur in torn cuff muscles. Thirty days after the tear, we observed a reduction in muscle fiber force and an induction of RNA molecules that regulate atrophy, fibrosis, lipid accumulation, inflammation, and macrophage recruitment. A marked accumulation of advanced glycation end products and a significant accretion of macrophages in areas of fat accumulation were observed. The extent of degenerative changes in old rats was greater than that observed in adults. In addition, we identified that the ectopic fat accumulation that occurs in chronic cuff tears does not occur by activation of canonical intramyocellular lipid storage and synthesis pathways.

A comparative analysis of fatty infiltration and muscle atrophy in patients with chronic rotator cuff tears and suprascapular neuropathy

Little is known of the mechanisms that lead to the muscle changes associated with rotator cuff disorders. We have observed that the magnetic resonance imaging (MRI) appearance of fatty infiltration (FI) and muscle atrophy (MA) differ between chronic cuff tears and suprascapular neuropathy, suggesting different pathophysiology. This study compares the different MRI changes that occur in chronic cuff tears and suprascapular neuropathy. Two groups were retrospectively identified: (1) RCT group (20 shoulders): patients with chronic tears of the supraspinatus and/or infraspinatus without electromyographic (EMG) evidence of suprascapular neuropathy; (2) neuro group (17 shoulders): patients with EMG documented suprascapular nerve dysfunction and absence of a rotator cuff tear. Magnetic resonance arthrograms were analyzed for the degree of FI and MA, and the morphology of the muscle was assessed, in particular the muscle border, pattern of FI, and extent of involvement. The muscle changes that occur following chronic cuff tears differ from that following denervation secondary to suprascapular neuropathy, especially with respect to the muscle border, degree of perineural fat, and overall distribution of FI. Highly specific and characteristic morphological patterns of FI exist for both chronic cuff tears and suprascapular neuropathy. Chronic rotator cuff tendon tears and suprascapular neuropathy are both associated with FIand MA of the rotator cuff muscles. The pattern of FI is markedly different in the 2 situations. These findings have diagnostic potential and may serve as a basis for further research concerning type, severity, and evolution of FI under different conditions and after treatment.

The effect of tear size and nerve injury on rotator cuff muscle fatty degeneration in a rodent animal model

Irreversible muscle changes after rotator cuff tears is a well-known negative prognostic factor after shoulder surgery. Currently, little is known about the pathomechanism of fatty degeneration of the rotator cuff muscles after chronic cuff tears. The purposes of this study were to (1) develop a rodent animal model of chronic rotator cuff tears that can reproduce fatty degeneration of the cuff muscles seen clinically, (2) describe the effects of tear size and concomitant nerve injury on muscle degeneration, and (3) evaluate the changes in gene expression of relevant myogenic and adipogenic factors after rotator cuff tears using the animal model. Rotator cuff tears were created in rodents with and without transection of the suprascapular nerve. The supraspinatus and infraspinatus muscles were examined at 2, 8, and 16 weeks after injury for histologic evidence of fatty degeneration and expression of myogenic and adipogenic genes. Histologic analysis revealed adipocytes, intramuscular fat globules, and intramyocellular fat droplets in the tenotomized and neurotomized supraspinatus and infraspinatus muscles. Changes increased with time and were most severe in the muscles with combined tenotomy and neurotomy. Adipogenic and myogenic transcription factors and markers were upregulated in muscles treated with tenotomy or tenotomy combined with neurotomy compared with normal muscles. The rodent animal model described in this study produces fatty degeneration of the rotator cuff muscles similar to human muscles after chronic cuff tears. The severity of changes was associated with tear size and concomitant nerve injury.

Abstract No. 385: A preclinical evaluation of the healing response of a novel chronic CVC cuff

Abstract No. 385: A preclinical evaluation of the healing response of a novel chronic CVC cuff

Evaluation of a cuff tear arthropathy hemiprosthesis for the treatment of glenohumeral arthritis in the presence of a chronic rotator cuff tear

Hypothesis Shoulders with chronic cuff deficiency and associated arthritis treated by hemiarthroplasty with tuberosity coverage maintain the active elevation that they had before surgery. The purpose of this study was to assess the functional and radiographic outcomes. Materials and methods Thirty-one shoulders with rotator cuff deficiency and associated arthritis, but no prior surgery, which were treated by one surgeon with an uncemented hemiarthroplasty with tuberosity coverage, were evaluated with radiographs, the Simple Shoulder Test and a Constant score at a minimum of 2 years postoperatively. Results Twenty-four of 31 shoulders were evaluated at a mean of 30 months postoperatively. None were classified as Seebauer IIB shoulders. Mean active forward elevation improved from 112 ◦ (20 to 160) to 127 ◦ (45 to 170). The mean postoperative Simple Shoulder Test score was 9 and the mean postoperative Constant score was 65. Shoulders maintained the pre-operative active elevation. Discussion Shoulder hemiarthroplasty with tuberosity coverage may be a reasonable treatment option in those without prior surgery, coracoacromial arch integrity, and an active lifestyle and/or young age. Active elevation following hemiarthroplasty with tuberosity coverage for rotator cuff deficiency and associated arthritis without escape depends upon pre-operative active elevation.

Treatment of rotator cuff tear

Shoulder impingement syndrome and rotator cuff tears are commonly encountered shoulder problems. Symptoms include pain, weakness and loss of motion. Subacromial impingement with subsequent tendinitis and bursitis is frequently found in young adult patients. Rotator cuff tears are a common cause of shoulder pain in patients over age 40. Causes of impingement include acromioclavicular joint arthritis, calcified coracoacromial ligament，structural abnormalities of the acromion and weakness of the rotator cuff muscles. The majority of subacromial impingement and incomplete rotator cuff tears may be successfully managed with conservative treatment (rest，ice packs. nonsteroidal anti-inflammatory drugs and physical therapy). Conservative therapy has been recommended for the treatment of a chronic cuff lesion with relatively good results. However, recent reports about operative treatment of cuff lesions have yielded more favorable results. The indication for operative treatment was persistent, severe or moderate pain at rest and impairment of shoulder function after initial conservative treatment. This article discusses etiology and treatment of rotator cuff disorders in the primary care setting. We recommend operative treatment of the rotator cuff for all cases in which the tear is full thickness. regardless of tear size，if patients have any symptoms. especially pain. When surgery is associated with a careful rehabilitation programme it may frequently allow patients to return to their baseline function.

Repair of full-thickness rotator cuff tears is recommended regardless of tear size and age: A retrospective study of 218 patients

Conservative therapy has been recommended for the treatment of a chronic cuff lesion with relatively good results. However, recent reports about operative treatment of cuff lesions have yielded more favorable results. Although the current literature seems to favor early treatment, there is an ongoing debate about the timing of the operation. During a 16-year period, 415 chronic full-thickness rotator cuff tears were operated on at our institution. The indication for operative treatment was persistent, severe or moderate pain at rest and impairment of shoulder function after initial conservative treatment. At follow-up, the symptoms were assessed by an interview, and all patients were clinically examined. Pain, function, range of active forward flexion, active abduction, strength (manual muscle testing), and patient satisfaction were recorded, and the results were evaluated by the University of California, Los Angeles shoulder rating scale. On the basis of our results, we recommend operative treatment of the rotator cuff for all cases in which the tear is full thickness, regardless of tear size, if patients have any symptoms, especially pain.

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Background: Evidence to justify the use of porcine small intestine submucosa (SIS) to augment large and massive rotator repairs is based on favorable results found in rabbit Achilles tendon and dog infraspinatus tendon repair studies. No published controlled study has evaluated the effectiveness of SIS augmentation of human rotator cuff repairs. The purpose of this study is to determine the effectiveness of SIS-Restore patch augmentation to repair chronic two tendon rotator cuff tears compared to repairs performed with the same techniques without SIS augmentation. Methods: Thirty shoulders with chronic two-tendon rotator cuff tears that were completely repairable by open surgery were randomized to either use SIS augmentation (Restore patch) or without the augmentation device. All patients completed a PENN shoulder score preoperatively and at their latest follow-up, which averaged 14 months (range 12-26.5). The size of the two-tendon tears was subcategorized into large or massive tears based on preoperative MRIs. Nine patients had large tears and twenty-one patients had massive tears. All patients underwent an MRI with intra-articular gadolinium one year after the repair to assess the status of the rotator cuff. Results: The percentage of patients with a healed rotator cuff in the SIS group was twenty-seven percent, and in the control group was sixty percent, which was not significant (p=0.11). After adjusting for the effect of tear size on the rate of healing, repairs without SIS-Restore augmentation were seven percent more likely to heal than repairs augmented with SIS-Restore (p=0.07). The postoperative PENN total score for the SIS-Restore group was ninety-one and for the control group was eighty-three, which was not significant (p=0.07). Healing of the cuff defect demonstrated a strong correlation with patient clinical scores regardless if a Restore patch was used. The postoperative PENN total scores for the healed repairs was ninety-six, and for the failed repairs was eighty-one, which was significant (p=0.02). The preoperative to postoperative percentage change in the PENN satisfaction score for the healed repairs was 400%, and for the failed repairs was 50%, which was significant (p=0.05). Conclusions: In large and massive chronic cuff tears, SIS-Restore did not increase improve the rate of tendon healing or the clinical outcome scores. There is a trend for the SIS group to have less favorable clinical outcomes in these types of tears. Based on these data, we do not recommend using SIS-Restore for the augmentation of massive chronic rotator cuff repairs using the surgical and post-operative procedures described in this study. If noted, the author indicates something of value received. The codes are identified as follows: a, research or institutional support; b, miscellaneous funding; c, royalties; d, stock options; e, consultant or employee. *The Food and Drug Administration has not cleared the drug and/or medical device for the use described in this presentation (ie, the drug or medical device is being discussed for an “off-label” use). If noted, the author indicates something of value received. The codes are identified as follows: a, research or institutional support; b, miscellaneous funding; c, royalties; d, stock options; e, consultant or employee. *The Food and Drug Administration has not cleared the drug and/or medical device for the use described in this presentation (ie, the drug or medical device is being discussed for an “off-label” use). If noted, the author indicates something of value received. The codes are identified as follows: a, research or institutional support; b, miscellaneous funding; c, royalties; d, stock options; e, consultant or employee. *The Food and Drug Administration has not cleared the drug and/or medical device for the use described in this presentation (ie, the drug or medical device is being discussed for an “off-label” use).

Paper #20 Lag signs in acute complete tears of the supraspinatus tendon. Does a subacromial lidocaine injection help in the clinical diagnosis? A prospective study

Compared to other tendon injuries, tears of the rotator cuff tendons may be difficult to diagnose in the acute stage. This may delay treatment and influence the prognosis of surgical repair. Most previous studies on this diagnostic dilemma are retrospective and deal mainly with chronic cuff tears. Hertel et al. showed that simple tests examining the inability to maintain certain positions of the arm, the lag signs, were sensitive for complete tears of the rotator cuff tendons. We hypothesized, that complete tears were indifferent to subacromial lidocaine injection due to loss of tendon integrity, and that this could be a valuable additional diagnostic test in the Emergency Ward. The study was designed to evaluate the value of clinical examination with and without subacromial lidocaine within the first weeks after an acute injury to the shoulder. From February 1998 till March 2000, a total of 104 patients with an acute injury to a previous healthy shoulder were included in a prospective diagnostic project comparing clinical findings with ultrasound. Only persons who were unable to active abduct the shoulder above 90 degrees, and whose radiographs showed no signs of fracture or joint dislocation were included. Of these, 29 (9 female, 20 male, median age 55) had a complete tear of the supraspinatus tendon diagnosed by arthroscopy. The patients were evaluated at median 12 (3–49) days after the injury with the classic drop arm test (DAT) and Hertel’s external rotation lag sign (ERls) specific for supra- and infraspinatus tears with and without subacromial lidocaine injection as well as with ultrasound. The control group consisted of the remaining 75 patients where the combined clinical and ultrasound examination revealed an intact cuff (=IC). The sensitivity and specificity was 41% and 80% for the DAT and 45% and 77% for the ERls. After subacromial lidocaine injection the similar figures for the DAT were 19% and 95%, and 19% and 92% for the ERls. The active abduction at median 12 (3–49) days after the injury improved from median 80 (0–180) degrees to median 110 (20–180) degrees after subacromial lidocaine injection. The lag signs specific for supraspinatus tears have a low sensitivity and an acceptable specificity in acute cases. After effective pain relief, the sensitivity for both tests was reduced to 19%, whereas the specificity increased. Pain seems to be the limiting factor in maintaining the arm position rather than loss of tendon integrity in an acute rotator cuff tear. Acute complete tears of the supraspinatus tendon cannot be detected by the clinical tests alone.