No difference in clinical outcome after rotator cuff repair performed within or later than 3 months after trauma: a retrospective cohort study.

PURPOSE: Rotator cuff (RC) tear is one of the most common injuries of the shoulder. Patients with RC tears often report a trauma initiating shoulder pain and impaired function. The aim of this retrospective analysis of a prospectively registered cohort was to elucidate whether the time interval between the trauma and RC repair, using a cut off of 3 months, affects the functional outcome after 2 years. METHODS: In a single orthopedic unit, 819 consecutive patients were treated with rotator cuff repair during the period from 2010 to 2014 and 733 of the patients completed the Western Ontario Rotator Cuff (WORC) index preoperatively and at 2-year follow-up. The Constant-Murley (CM) score was completed by trained physiotherapists after a clinical examination both preoperatively and at 2-year follow-up. Preoperative magnetic resonance imaging (MRI) was performed in all patients and postoperatively in 65% of the included patients. Re-tears and partial repairs were excluded, as were patients with pseudoparalysis who were given high priority and underwent surgery during the first 3 weeks after trauma. RESULTS: Of the 733 treated patients, 437 (60%) reported having had a shoulder trauma in their medical history initiating their shoulder symptoms, and of these, 358 met the inclusion criteria. 296 patients with non-traumatic tears, 9 repairs done within 3 weeks after trauma, 25 partial repairs, 33 re-tears and 12 others were excluded. At 2-year follow-up there was no significant difference in WORC index (n.s.) or CM score (n.s.) between patients who had their RC repaired within or more than 3 months after trauma. In patients where RC repair was performed within 3 months, the WORC index improved by 42.9%, and in the group of patients operated later than 3 months, the increase was 38.7%. This difference between the groups was neither statistically significant (n.s.) nor clinically relevant. On postoperative MRI, 80% of the repairs were healed in both groups. CONCLUSION: In this retrospective cohort study, no differences in clinical outcome were found when RC repair was performed between 3 weeks and 3 months or later than 3 months after injury in patients describing their onset of symptoms as traumatic. LEVEL OF EVIDENCE: III.

No Functional Difference Between Three and Six Weeks of Immobilization After Arthroscopic Rotator Cuff Repair: A Prospective Randomized Controlled Non-Inferiority Trial.

PURPOSE: The aim of this study was to compare clinical and radiologic results among patients with 3 versus 6 weeks of immobilization after arthroscopic rotator cuff (RC) repair in a prospective randomized controlled non-inferiority trial. METHODS: One hundred twenty patients were included after RC surgery for a small- to medium-sized tear of supraspinatus and upper infraspinatus tendons. Group A was immobilized in a simple sling for 3 weeks, and group B had a brace with a small abduction pillow with the arm in neutral position for 6 weeks. All patients started active range of motion when they removed the sling/brace. One hundred eighteen (98%) patients were assessed at 1-year follow-up. They underwent magnetic resonance imaging (MRI) of the shoulder, filled out the Western Ontario Rotator Cuff (WORC) index, and were evaluated with a Constant Murley (CM) score. RESULTS: Statistical non-inferiority was demonstrated for the 2 groups on the basis of the WORC index, the primary endpoint at 1 year. The objective for the non-inferiority test was to determine whether the expected mean WORC index for group A was at most 13% worse than standard treatment (Group B). The WORC index at 1 year was similar in both groups, with mean percent scores of 83% in group A and 87% in group B (mean difference = -4; 95% one-sided CI -9, -4). Age-adjusted CM scores were also similar, with means of 86 in group A and 90 in group B (mean difference = -4; 95% CI -13, 5; P = .37). MRI after 1 year showed 50 (89%) patients in each group with healed RC repair. Four patients in group A had complications: 1 acute postoperative infection, 2 cases of postoperative capsulitis treated with corticosteroid injections, and 1 repeat operation because of a loose anchor and subacromial pain. No patients in group B had complications. CONCLUSION: RC repair resulted in improved postoperative shoulder function, regardless of whether the shoulder was immobilized for 3 or 6 weeks. Three weeks of postoperative immobilization with sling use was non-inferior to the commonly used regimen involving 6 weeks of immobilization in a brace with regard to the WORC index at 12 months' follow-up. MRI indicated similar degrees of healing between the groups. Based on these findings, it is safe to immobilize patients in a simple sling for 3 to 6 weeks after repair of small to medium RC tears. LEVEL OF EVIDENCE: Level I, high-quality randomized controlled trial with statistically significant differences.

Targeted intervention of acute postoperative infection after rotator cuff repair results in good functional outcomes.

PURPOSE: The primary goal of this retrospective review of a prospective database was to document the functional results after acute postoperative deep infection following rotator cuff repair in a single orthopaedic unit over a period of 5 years. Secondary goals were to document the effect of infection on healing of the cuff repair and to describe its incidence, diagnostic challenges, pathogens and management. METHODS: Patients undergoing arthroscopic rotator cuff repair were prospectively registered from 2010 to 2014. Eleven out of 1072 repairs developed an acute postoperative infection. The patients were examined with an MRI scan, Constant-Murley (CM) score and the Western Ontario Rotator Cuff Index (WORC) at final follow-up (median of 22 months). RESULTS: All 11 patients who developed acute postoperative deep infections were males. Median age was 56 years (range 41-68). All patients underwent arthroscopic debridement and biopsies were collected at a median of 26 days (range 14-50) after primary surgery. In ten patients, Propionibacterium acnes was cultured, six of these patients also had positive cultures for coagulase-negative staphylococci. In the remaining patient, only coagulase-negative staphylococcus was cultured. Five patients were treated with one arthroscopic debridement, five had two arthroscopic debridements and one required arthroscopic debridement four times before the infection was eradicated. Two patients had their implants removed due to loosening of the suture anchors. All patients were treated with parenteral antibiotics for 1-4 weeks, followed by oral treatment for 1-5 weeks. At median 22 months (range 11-28) follow-up the median CM score was 84 and median WORC index was 81%. Ten patients had a postoperative MRI scan after a median of 23 months (range 3-49), with eight presenting a healed cuff repair. CONCLUSION: The findings of this study support the rapid, targeted intervention of acute postoperative infection after RC repair with immediate arthroscopic debridement, irrigation and biopsies for bacteriological diagnostics followed by parenteral antibiotics. Furthermore, repeated arthroscopic debridement and irrigation are recommended if signs of infection persist. Removal of the implant is rarely needed. Despite the postoperative acute infection, these patients presented good functional results at final follow-up. LEVEL OF EVIDENCE: Level III.

Paralabral cysts of the shoulder treated with isolated labral repair: effect on pain and radiologic findings.

BACKGROUND: Paralabral cysts emanating from posterosuperior labral tears may compress the suprascapular nerve and induce neuropathy. This study prospectively assessed patients with labral tears and symptomatic paralabral cysts treated with isolated labral repair. Pain relief, time to cyst resolution, reversibility of muscular edema, atrophy, fatty infiltration, and bone erosion were evaluated. METHODS: Forty-seven patients with symptomatic posterosuperior paralabral cysts were treated with isolated labral repair. Magnetic resonance imaging (MRI) was repeated 6 and 12 weeks postoperatively or until cyst resolution. In a subgroup of 15 patients, MRI was performed the day before the operation, the first postoperative day, and at 2 weeks. RESULTS: Median cyst size was 6.8 cm3 (range, 2.1-88.9; standard deviation [SD], 18.3 cm3). Preoperatively, 20 patients (43%) presented clinical muscle atrophy and radiologic edema on MRI, 8 had fatty infiltration, and 3 presented bony scapular erosion caused by cyst compression. Median time to cyst resolution and regression of muscular edema was 11 weeks (range, 3-20; SD, 8.8 weeks) and 14 weeks (range, 3-52; SD 10.6 weeks), respectively. Preoperative fatty infiltration grade I and II of the supraspinatus and infraspinatus muscles was reduced in two patients. Bony erosions remodeled after cyst resolution. Mean pain ratings (1-10 scale) improved from 7.7 (SD, 1.8) to 1.3 (SD, 1.3; 95% confidence interval of difference, 5.5-6.8; P < .001). CONCLUSION: Labral repair leads to significant pain relief with cyst resolution within 2 to 3 months in most patients. Secondary muscle pathology (ie, edema, atrophy and fatty infiltration) may be partially or completely reversed. Bony erosion caused by cyst compression may be remodeled after cyst resolution.

Angiopoietin-like 4 promotes angiogenesis in the tendon and is increased in cyclically loaded tendon fibroblasts.

KEY POINTS: Angiopoietin-like 4 (ANGPTL4) modulates tendon neovascularization. Cyclic loading stimulates the activity of transforming growth factor-ß and hypoxia-inducible factor 1α and thereby increases the expression and release of ANGPTL4 from human tendon cells. Targeting ANGPTL4 and its regulatory pathways is a potential avenue for regulating tendon vascularization to improve tendon healing or adaptation. ABSTRACT: The mechanisms that regulate angiogenic activity in injured or mechanically loaded tendons are poorly understood. The present study examined the potential role of angiopoietin-like 4 (ANGPTL4) in the angiogenic response of tendons subjected to repetitive mechanical loading or injury. Cyclic stretching of human tendon fibroblasts stimulated the expression and release of ANGPTL4 protein via transforming growth factor-ß (TGF-ß) and hypoxia-inducible factor 1α (HIF-1α) signalling, and the released ANGPTL4 was pro-angiogenic. Angiogenic activity was increased following ANGPTL4 injection into mouse patellar tendons, whereas the patellar tendons of ANGPTL4 knockout mice displayed reduced angiogenesis following injury. In human rotator cuff tendons, the expression of ANGPTL4 was correlated with the density of tendon endothelial cells. To our knowledge, this is the first study characterizing a role of ANGPTL4 in the tendon. ANGPTL4 may assist in the regulation of vascularity in the injured or mechanically loaded tendon. TGF-ß and HIF-1α comprise two signalling pathways that modulate the expression of ANGPTL4 by mechanically stimulated tendon fibroblasts and, in the future, these could be manipulated to influence tendon healing or adaptation.

Rotator cuff tear degeneration and cell apoptosis in smokers versus nonsmokers.

PURPOSE: The purpose of this study was to assess the effect of smoking on supraspinatus tendon degeneration, including cellular alterations, proliferation, and apoptosis of tendon cells. METHODS: Supraspinatus tendon samples of 10 smokers and 15 nonsmokers with full-thickness tears were compared, focusing on the severity of tendon histopathology including apoptosis (programmed cell death), cellularity, and proliferation. Immunohistochemistry was used to assess the density of apoptotic cells and proliferation. The extent of tendon degeneration was classified according to a revised version of the Bonar tendon histopathology score. RESULTS: The smokers were younger (P = .01). The symptom duration among smokers was longer (P < .05). The supraspinatus tendons from the smokers presented significantly more advanced degenerative changes (Bonar score, 13.5 [interquartile range, 1.4] v 9 [interquartile range, 3]; P < .001). The smokers' tendons showed increased density of apoptotic cells (0.108 [SE, 0.038] v 0.0107 [SE, 0.007]; P = .024) accompanied by reduced tenocyte density (P = .019) and upregulation of proliferative activity (P < .0001). CONCLUSIONS: Smoking is associated with worsened supraspinatus tendon histopathology and increased apoptosis. CLINICAL RELEVANCE: Pronounced degenerative changes, reduced tendon cellularity, and increased apoptosis may indicate reduced tendon healing capacity in smokers.

Sports and exercise-related tendinopathies: a review of selected topical issues by participants of the second International Scientific Tendinopathy Symposium (ISTS) Vancouver 2012.

In September 2010, the first International Scientific Tendinopathy Symposium (ISTS) was held in Umeå, Sweden, to establish a forum for original scientific and clinical insights in this growing field of clinical research and practice. The second ISTS was organised by the same group and held in Vancouver, Canada, in September 2012. This symposium was preceded by a round-table meeting in which the participants engaged in focused discussions, resulting in the following overview of tendinopathy clinical and research issues. This paper is a narrative review and summary developed during and after the second ISTS. The document is designed to highlight some key issues raised at ISTS 2012, and to integrate them into a shared conceptual framework. It should be considered an update and a signposting document rather than a comprehensive review. The document is developed for use by physiotherapists, physicians, athletic trainers, massage therapists and other health professionals as well as team coaches and strength/conditioning managers involved in care of sportspeople or workers with tendinopathy.

Increased levels of apoptosis and p53 in partial-thickness supraspinatus tendon tears.

PURPOSE: The role of apoptosis in the progression of rotator cuff tendinopathy remains poorly understood. In particular, the extent of apoptosis in the partially torn supraspinatus tendon has not been well examined. METHODS: Biopsies were obtained from nine partially torn supraspinatus tendons, from the matched intact subscapularis tendons, and from 10 reference subscapularis tendons. Immunohistochemistry was used to assess the density of apoptotic cells (activated caspase-3; Asp175), proliferation (Ki67), and p53 (M7001), a key protein involved in regulating cell death. The Bonar scale was used to evaluate tendon degeneration. RESULTS: The density of apoptotic tendon cells and the density of cells expressing p53 were significantly increased in both the partially torn supraspinatus tendons and in the matched subscapularis tendons, compared with uninjured reference tendons. The Bonar score revealed significant tendon degeneration in the partially torn supraspinatus tendons compared with both matched and reference subscapularis tendons. Tendon cell proliferation was significantly increased in the partially torn supraspinatus tendons compared with reference subscapularis tendons. CONCLUSIONS: Partial-thickness tears of the supraspinatus tendon demonstrated an increased density of apoptotic, p53+ tendon cells. The fact that apoptosis was accompanied by increased tendon cell proliferation suggests that apoptosis may be related to an ongoing injury-repair process. Increased tenocyte apoptosis may be a relatively early feature in rotator cuff tendinopathy and could represent a possible target for therapeutic intervention.

Lower muscle regenerative potential in full-thickness supraspinatus tears compared to partial-thickness tears.

BACKGROUND AND PURPOSE: Rotator cuff tears are associated with secondary rotator cuff muscle pathology, which is definitive for the prognosis of rotator cuff repair. There is little information regarding the early histological and immunohistochemical nature of these muscle changes in humans. We analyzed muscle biopsies from patients with supraspinatus tendon tears. METHODS: Supraspinatus muscle biopsies were obtained from 24 patients undergoing arthroscopic repair of partial- or full-thickness supraspinatus tendon tears. Tissue was formalin-fixed and processed for histology (for assessment of fatty infiltration and other degenerative changes) or immunohistochemistry (to identify satellite cells (CD56+), proliferating cells (Ki67+), and myofibers containing predominantly type 1 or 2 myosin heavy chain (MHC)). Myofiber diameters and the relative content of MHC1 and MHC2 were determined morphometrically. RESULTS: Degenerative changes were present in both patient groups (partial and full-thickness tears). Patients with full-thickness tears had a reduced density of satellite cells, fewer proliferating cells, atrophy of MHC1+ and MHC2+ myofibers, and reduced MHC1 content. INTERPRETATION: Full-thickness tears show significantly reduced muscle proliferative capacity, myofiber atrophy, and loss of MHC1 content compared to partial-thickness supraspinatus tendon tears.

Tenocyte apoptosis in the torn rotator cuff: a primary or secondary pathological event?

Little information exists on the contribution of apoptosis to pathological tendon changes in rotator cuff tendinopathy. The purpose of this study was to quantitate the rate of tenocyte apoptosis in torn supraspinatus tendons and in the matched intact subscapularis and to examine the potential relation between apoptotic index (AI) and tendon pathology. In addition, the authors examined tenocyte density, proliferation rate and p53 gene expression patterns to gain further insight into relevant pathological mechanisms in the torn suprapinatus. 15 torn supraspinatus tendons with matched intact subscapularis tendon samples and 10 reference subscapularis samples were collected. Immunohistochemistry was used to define the AI (F7-26), proliferation rate (Ki67) and presence of p53 (M7001). Tendon degeneration was evaluated according to the Bonar scale. Expression of p53 and relevant genes (n=84) was examined on a subset of samples using microfluidic arrays. The AI was significantly increased in torn supraspinatus tendon and matched subscapularis tendon (R² =0.5742; p=0.0005). Cell density and proliferation rate were also elevated in torn supraspinatus compared with reference subscapularis tendons (p<0.05). A significant increase in p53 occurred specifically in torn supraspinatus tendon (p<0.05), and several genes encoding p53-inhibiting proteins were downregulated in association, including HDAC1 (p<0.05), MDM4 (p<0.001) and PPM1D (p<0.05). Our results suggest that tenocyte apoptosis results from more than one mechanism in the injured rotator cuff, including both intrinsic factors related specifically to the torn supraspinatus tendon, as well as a more generalised effect on the adjacent subscapularis tendon.

Prognostic Factors for Functional Outcome After Rotator Cuff Repair: A Prospective Cohort Study With 2-Year Follow-up.

BACKGROUND: Although shoulder function is reported to be generally good after rotator cuff repair, limited knowledge exists regarding which prognostic factors predict functional outcomes. PURPOSE: To identify pre- and perioperative predictors of functional outcomes after arthroscopic rotator cuff repair. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A cohort of 733 consecutive patients treated with rotator cuff repair between 2010 and 2014 in a single orthopaedics unit was included. Data were collected prospectively and included pre- and perioperative variables. Univariate and multivariable linear regression analyses were used to predict shoulder function at 2-year follow-up, as measured by the Western Ontario Rotator Cuff Index (WORC). RESULTS: In total, 647 (88%) patients were followed for 25 ± 5 months (mean ± SD; range, 17-66 months). In the multivariable regression model, the adjusted R2 was 0.360, indicating that 36% of the variation in the WORC at final follow-up could be explained by this statistical model. The multivariable linear regression analysis revealed that the strongest positive independent predictors of shoulder function at 2 years were preoperative WORC and Constant-Murley score in the contralateral shoulder. The model also indicated that activities of daily living, age, subacromial decompression, and biceps surgery had independent positive associations with better shoulder function at 2 years. In addition, previous surgery in the ipsilateral or contralateral shoulder, smoking, partial rotator cuff repair, preoperative pain, and atrophy in the infraspinatus were all independent factors negatively associated with shoulder function after 2 years. The overall healing rate of complete repairs per magnetic resonance imaging was 80%. CONCLUSION: The most important finding of the present study was that the strongest prognostic factors for better WORC at 2-year follow-up were better preoperative WORC and Constant-Murley score in the contralateral shoulder. Although not all the prognostic factors identified in this study are modifiable, they can still be useful for guiding patients in shared decision making with the surgeon. This cohort study shows that if selection of patients is performed properly, it is possible to obtain a successful outcome.