Does open repair of anterosuperior rotator cuff tear prevent muscular atrophy and fatty infiltration?

Identification of Diagnostic Biomarkers Associated with Stromal and Immune Cell Infiltration in Fatty Infiltration After Rotator Cuff Tear by Integrating Bioinformatic Analysis and Machine-Learning

Purpose

The present study aimed to explore potential diagnostic biomarkers for fatty infiltration (FI) of the rotator cuff muscles after rotator cuff tear (RCT) and investigate the influence of stromal and immune cell infiltration on this pathology.

Methods

The GSE130447 and GSE103266 datasets were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified, and gene set enrichment analyses were performed by R software. Two machine learning algorithms, random forest and multiple support vector machine recursive feature elimination (mSVM-RFE), were used to screen candidate biomarkers. The diagnostic value of the screened biomarkers was further validated by the area under the ROC curve (AUC) in the GSE103266 dataset. Murine microenvironment cell population counter (mMCP-counter) method was employed to estimate stromal and immune cell infiltration of FI. The correlation between biomarkers and infiltrated immune and stromal cell subsets was further analyzed.

Results

A total of 2123 DEGs were identified. The identified DEGs were predominantly linked to immune system process, extracellular matrix organization and PPAR signalling pathway. FABP5 (AUC = 0.958) and MGP (AUC = 1) were screened as diagnostic biomarkers of FI. Stromal and immune cell infiltration analysis showed that monocytes, mast cells, vessels, endothelial cells and fibroblasts may be related to the process of FI. FABP5 and MGP were positively correlated with vessels whereas negatively correlated with monocytes and mast cells.

Conclusion

FABP5 and MGP can serve as diagnostic biomarkers of FI after RCT, and stromal and immune cell infiltration may play a crucial role in this pathology.

A "Comma Sign"-Directed Subscapularis Repair in Anterosuperior Rotator Cuff Tears Yields Biomechanical Advantages in a Cadaveric Model

BACKGROUND

Additional stabilization of the "comma sign" in anterosuperior rotator cuff repair has been proposed to provide biomechanical benefits regarding stability of the repair.

PURPOSE

This in vitro investigation aimed to investigate the influence of a comma sign-directed reconstruction technique for anterosuperior rotator cuff tears on the primary stability of the subscapularis tendon repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 18 fresh-frozen cadaveric shoulders were used in this study. Anterosuperior rotator cuff tears (complete full-thickness tear of the supraspinatus and subscapularis tendons) were created, and supraspinatus repair was performed with a standard suture bridge technique. The subscapularis was repaired with either a (1) single-row or (2) comma sign technique. A high-resolution 3D camera system was used to analyze 3-mm and 5-mm gap formation at the subscapularis tendon-bone interface upon incremental cyclic loading. Moreover, the ultimate failure load of the repair was recorded. A Mann-Whitney test was used to assess significant differences between the 2 groups.

RESULTS

The comma sign repair withstood significantly more loading cycles than the single-row repair until 3-mm and 5-mm gap formation occurred (P≤ .047). The ultimate failure load did not reveal any significant differences when the 2 techniques were compared (P = .596).

CONCLUSION

The results of this study show that additional stabilization of the comma sign enhanced the primary stability of subscapularis tendon repair in anterosuperior rotator cuff tears. Although this stabilization did not seem to influence the ultimate failure load, it effectively decreased the micromotion at the tendon-bone interface during cyclic loading.

CLINICAL RELEVANCE

The proposed technique for stabilization of the comma sign has shown superior biomechanical properties in comparison with a single-row repair and might thus improve tendon healing. Further clinical research will be necessary to determine its influence on the functional outcome.

Arthroscopic knotless repair: an effective technique for small-sized supraspinatus tendon tears

PURPOSE

The purpose was to evaluate the clinical and radiological results of knotless repair with flat-braided suture in full small-sized supraspinatus tendon tears (< 1 cm).

METHODS

A consecutive series of 54 patients with isolated small supraspinatus tendon tear (< 1 cm and Goutallier index < 2) was evaluated in the study. Patients underwent a knotless arthroscopic repair using flat-braided suture (2 mm wide). Minimal follow-up required was 5 years. Changes in Murley-Constant score, ASES score, strength, and pain relief were assessed. The Sugaya score was used to confirm the tendon repair on MRI. Data were analyzed in two subgroups: technique with additional U point for dog ear deformity (group 1) and technique without additional U point (group 2). The immobilization period was 3 weeks long. Passive mobilization was immediate.

RESULTS

Fifty-four patients were included. Mean age was 57 ± 4 years. The average follow-up was 68 ± 10 months. Average preoperative score of Constant was 51.2 ± 8.5 and 83.1 ± 14.6 at the end of the follow-up (p < 0.001). Mean VAS went from 5.8 ± 1.8 to 1.9 ± 2.1 (p < 0.001). Average forward elevation of the shoulder went from 86.3° ± 9 preoperatively to 169.6° ± 15.9 at the end of the follow-up (p < 0.001). The strength score was significantly higher post-operatively (18.4 vs. 8.3, p < 0.001.). The ASES score was significantly improved 49.1 ± 13.1 vs. 88.6 ± 15.8, p < 0.001). The MRI assessment revealed 94% of Sugaya 1-2. No significant difference was observed between group 1 and 2 regarding all clinical outcomes. Two complex regional pain syndromes were described with a favorable evolution. Three patients presented a retear requiring an iterative arthroscopic repair.

CONCLUSION

The use of a knotless arthroscopic construct with flat-braided suture for small supraspinatus repair achieved excellent structural and clinical results. This technique is fully adequate for the arthroscopic treatment of such tears, enabling early mobilization.

LEVEL OF EVIDENCE

Level III.

Anterior rotator cable disruption does not affect outcomes in rotator cuff tear with subscapularis involvement

PURPOSE

The purpose of this study was to compare clinical and radiological outcomes after arthroscopic repair of two different rotator cuff tear configurations: anterosuperior rotator cuff tear and rotator cuff tears with subscapularis involvement. It was hypothesized that, although both tear configurations would show significant improvement in clinical outcomes after arthroscopic repair, the rotator cuff tears with subscapularis involvement where the anterior rotator cable maintains its integrity would have better clinical outcomes and structural integrity.

METHODS

This study included 226 patients who underwent arthroscopic repair of anterosuperior rotator cuff tears (n = 107, group A) and rotator cuff tears with subscapularis involvement (n = 119, group B). The visual analog scale (VAS) pain score, subjective shoulder value (SSV), American Shoulder and Elbow Surgeons (ASES) score, University of California at Los Angeles (UCLA) shoulder score, and active range of motion (ROM) were assessed. Modified belly press test was performed to assess the strength of the subscapularis muscle. Cuff integrity was evaluated using magnetic resonance arthrography or computed tomographic arthrography at 6 months after operation.

RESULTS

At 3-year follow-up, the VAS score, SSVs, ASES scores, UCLA shoulder scores, active ROM, and modified belly press test showed significant improvement in both groups (p < 0.001). However, these improvements showed no statistical significance between the two groups. On follow-up radiologic evaluations, no significant difference in re-tear rates between group A (25 of 107, 23.4%) and group B (23 of 119, 19.3%) was observed.

CONCLUSIONS

The presence of anterior cable involvement of the anterosuperior rotator cuff tear did not affect postoperative clinical outcomes and re-tear rate compared to rotator cuff tears with subscapularis involvement where the anterior cable integrity was maintained, although the anterosuperior rotator cuff tear was associated with more significant preoperative supraspinatus fatty infiltration. Therefore, the present study determined that it would not be necessary to differentiate treatment protocols between these patterns.

LEVEL OF EVIDENCE

Level III.

In vivo testing of an injectable matrix gel for the treatment of shoulder cuff muscle fatty degeneration

INTRODUCTION

Extracellular matrix (ECM) gels have shown efficacy for the treatment of damaged tissues, most notably cardiac muscle. We hypothesized that the ECM gel prepared from skeletal muscle could be used as a treatment strategy for fatty shoulder cuff muscle degeneration.

METHODS

We conducted experiments to (1) evaluate host biocompatibility to ECM gel injection using a rat model and (2) examine the effect of ECM gel injection on muscle recovery after delayed repair of a released supraspinatus (SSP) tendon using a rabbit model.

RESULTS

The host biocompatibility to the ECM gel was characterized by a transient rise (first 2 weeks only) in several genes associated with macrophage infiltration, matrix deposition, and inflammatory cytokine production. By 8 weeks all genes had returned to baseline levels and no evidence of fibrosis or chronic inflammation was observed from histology. When gel injection was combined with SSP tendon repair, we observed a significant reduction (7%) in SSP muscle atrophy (24 + 3% reduction from uninjured) when compared with treatment with tendon repair only (31 + 7% reduction). Although fatty degeneration was elevated in both treatment groups, fat content trended lower (2%) in response to combined tendon repair and intramuscular ECM injection (4.1 + 2.1%) when compared with tendon repair only (6.1 + 2.9%). Transcriptome analysis revealed adipogenesis and osteoarthritis pathway activation in the repair only group. These key pathways were abrogated in response to treatment using combined repair plus gel.

DISCUSSION

The findings suggest that ECM injection had a modest but positive effect on muscle mass, fatty degeneration, and key cellular signaling pathways.

Adipocyte hyperplasia: the primary mechanism of supraspinatus intramuscular fat accumulation after a complete rotator cuff tendon tear: a study in the rabbit

Intramuscular fat (IMF) accumulates in muscles of the rotator cuff after tendon tear. The number and cross-sectional area of fat clumps and of adipocytes were quantified on osmium tetroxide stained sections of the proximal, middle and distal quarters of SSP muscles 4, 8 and 12 weeks after SSP tendon division in a rabbit model. Linear mixed-effects models were fitted to the data and statistical significance was evaluated by ANOVA. Both the number (P<0.001) and cross-sectional area (P<0.0005) of fat clumps increased after tendon detachment while time had no significant effect (both at P>0.01). IMF accumulation was more important in the distal quarter of detached SSP muscle near tendon sectioning and characterized by increases of the number (P<0.0005) and cross-sectional area of fat clumps (P<0.0005) compared to the proximal quarter. Adipocyte number increased after tendon detachment (P<0.0005) and over time (P<0.01). The cross-sectional area of adipocytes increased in the detached group compared to controls (P<0.01) while time had no significant effect (P>0.01). Interestingly, the number of adipocytes in the distal quarter increased (P<0.0005) but the cross-sectional area was smaller (P<0.0005) compared to adipocytes in the proximal quarter. Adipocyte hyperplasia localized near tendon sectioning was the main contributor to fat accumulation in the detached SSP muscles.

Ten-year clinical and anatomic follow-up after repair of anterosuperior rotator cuff tears: influence of the subscapularis

BACKGROUND

Anterosuperior rotator cuff tears are more frequent than expected. We report the results of a 10-year follow-up study after repair. Our hypothesis was that the extent of the subscapularis tear influenced the prognosis.

MATERIALS AND METHODS

The study population consisted of all 138 patients who underwent surgery in 14 participating centers in 2003 for full-thickness tears of the rotator cuff with lesions in the subscapularis and supraspinatus tendons. The patients were divided into 2 groups, depending on whether the subscapularis lesion affected only the superior half of the tendon (group A) or extended into the lower half (group B). Ninety-two patients (56 ± 7 years; 71 in group A and 21 in group B) were available for follow-up after 10 years (127 ± 16 months) with magnetic resonance imaging to evaluate tendon healing and muscle condition.

RESULTS

The mean Constant scores were 59 ± 16 before surgery and 77 ± 14 at follow-up (P = 1.7 × 10^-12). The retear rates were 25% for the supraspinatus and 13.5% for the subscapularis tendon. The clinical results for group A patients were better than those for group B. Severe fatty infiltration was observed more frequently in the subscapularis than in the supraspinatus muscle (27% vs. 12% of cases). Supraspinatus healing influenced subscapularis healing and fatty infiltration.

CONCLUSIONS

Repair of anterosuperior rotator cuff tears is satisfactory at 10 years, particularly if the subscapularis tear is not extensive. An extensive subscapularis tear is a negative prognosis factor. Postoperatively, fatty infiltration of the subscapularis muscle was frequently observed despite tendon healing.

The characterization of decellularized human skeletal muscle as a blueprint for mimetic scaffolds

The use of decellularized skeletal muscle (DSM) as a cell substrate and scaffold for the repair of volumetric muscle loss injuries has shown therapeutic promise. The performance of DSM materials motivated our interest in exploring the chemical and physical properties of this promising material. We suggest that these properties could serve as a blueprint for the development of next generation engineered materials with DSM mimetic properties. In this study, whole human lower limb rectus femoris (n = 10) and upper limb supraspinatus muscle samples (n = 10) were collected from both male and female tissue donors. Skeletal muscle samples were decellularized and nine property values, capturing key compositional, architectural, and mechanical properties, were measured and statistically analyzed. Mean values for each property were determined across muscle types and sexes. Additionally, the influence of muscle type (upper vs lower limb) and donor sex (male vs female) on each of the DSM material properties was examined. The data suggests that DSM materials prepared from lower limb rectus femoris samples have an increased modulus and contain a higher collagen content then upper limb supraspinatus muscles. Specifically, lower limb rectus femoris DSM material modulus and collagen content was approximately twice that of lower limb supraspinatus DSM samples. While muscle type did show some influence on material properties, we did not find significant trends related to sex. The material properties reported herein may be used as a blueprint for the data-driven design of next generation engineered scaffolds with muscle mimetic properties, as well as inputs for computational and physical models of skeletal muscle.

Strength recovery after arthroscopic anterosuperior cuff repair: analysis of a consecutive series

PURPOSE

The purpose of this study was to look at the functional outcomes of arthroscopic repair of anterosuperior rotator cuff tears.

METHODS

Sixty-one patients who underwent arthroscopic repair of anterosuperior cuff tears were retrospectively reviewed. At a minimum 6 months of follow-up, shoulder functional outcome scores including the Constant score (CS), simple shoulder test (SST) and visual analogic scale (VAS) were collected. Strength recovery for supraspinatus and subscapularis was investigated.

RESULTS

All patients (mean age 59 ± 7) were available at a mean follow-up of 18 ± 7 months. The average CS improved from 30.8 ± 10.2 preoperatively to 76.5 ± 12.0 postoperatively, average SST from 2.6 ± 2.0 to 8.8 ± 2.9 and average VAS pain scale from 3.8 ± 1 to 0.5 ± 0.5 (p < 0.0001). Strength at belly-press and Jobe tests significantly improved (p < 0.0001). All patients with the exception of one were satisfied with the intervention.

CONCLUSIONS

Arthroscopic repair of anterosuperior rotator cuff tears provides a significant improvement in pain relief and shoulder function. Strength recovery is demonstrated in medium correlation with tendon healing.

The subscapularis-sparing approach in humeral head replacement

BACKGROUND

This report represents a prospective case series evaluating an open deltopectoral approach, both radiologically and clinically, without tenotomy or complete takedown of the subscapularis tendon insertion. We hypothesized that this novel technical approach would allow preservation of the upper tendon border, thus decreasing subscapularis repair failures and fatty infiltration while simultaneously allowing accelerated rehabilitation.

METHODS

Fifty patients underwent humeral head replacement surgery through a subscapularis-sparing approach. In this approach, we take down only the inferior 30% to 50% of the subscapularis tendon, leaving the critical superior aspect of the tendon attached to the lesser tuberosity. Forty-three patients were included in the postoperative results (7 were lost to follow-up). Nineteen patients had a postoperative magnetic resonance imaging study, and 24 patients had ultrasound evaluation. Physical examination included belly-press and lift-off tests; follow-up included visual analog scale, American Shoulder and Elbow Surgeons, Constant, modified UCLA, Rowe, and Short Form 12 scores.

RESULTS

All patients had a minimum 2-year follow-up. All patients had subscapularis strength equal to the opposite side as measured by lift-off, belly-press, and bear hug tests. Average postoperative scores all showed statistically significant improvement except for general health. All had an intact subscapularis tendon attachment as evaluated by either magnetic resonance imaging or ultrasound imaging. None had atrophy in the muscle belly.

CONCLUSIONS

The subscapularis-sparing, minimally invasive approach to the glenohumeral joint provides adequate exposure to allow humeral head replacement. When the upper border of the subscapularis insertion is left intact, there is a decreased risk of postoperative failure (rupture or atrophy) of the subscapularis tendon.

Muscle atrophy and fatty infiltration after an acute rotator cuff repair in a sheep model

INTRODUCTION

rotator cuff tears (RCTs) are the most common tendon injury seen in orthopedic patients. Muscle atrophy and fatty infiltration of the muscle are crucial factors that dictate the outcome following rotator cuff surgery. Though less studied in humans, rotator cuff muscle fibrosis has been seen in animal models as well and may influence outcomes as well. The purpose of this study was to determine if the rotator cuff would develop muscle changes even in the setting of an acute repair in a sheep model. We hypothesized that fatty infiltration and fibrosis would be present even after an acute repair six months after initial surgery.

METHODS

twelve female adult sheep underwent an acute rotator cuff tear and immediate repair on the right shoulder. The left shoulder served as a control and did not undergo a tear or a repair. Six months following acute rotator cuff repairs, sheep muscles were harvested to study atrophy, fatty infiltration, and fibrosis by histological analysis, western blotting, and reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

the repair group demonstrated an increase expression of muscle atrophy, fatty infiltration, and fibrosis related genes. Significantly increased adipocytes, muscle fatty infiltration, and collagen deposition was observed in rotator cuff muscles in the tendon repair group compared to the control group.

CONCLUSIONS

rotator cuff muscle undergoes degradation changes including fatty infiltration and fibrosis even after the tendons are repair immediately after rupture.

LEVEL OF EVIDENCE

Basic Science Study.

Magnetic resonance imaging criteria for the assessment of the rotator cuff after repair: a systematic review

PURPOSE

The purpose of this systematic review was to detect the reliability of the currently available magnetic resonance imaging measurements used in the evaluation of repaired rotator cuff.

METHODS

Search was performed using major electronic databases from their inception to February 2014. All studies reporting post-operative magnetic resonance assessment after rotator cuff repair were included. After the identification of available magnetic resonance criteria, reliability studies were further analysed. Descriptive statistics were used to summarize findings. Methodological quality was assessed using the Quality Appraisal of Reliability Studies checklist.

RESULTS

One hundred and twenty studies were included in the review. Twenty-six different criteria were identified. Ten studies reported inter-observer reliability, and only two assessed intra-observer reliability of some of the identified criteria. Structural integrity was the most investigated criterion. The dichotomized Sugaya's classification showed the highest reliability (k = 0.80-0.91). All other criteria showed moderate to low inter-observer reliability. Tendon signal intensity and footprint coverage showed a complete discordance. Intra-observer reliability was high for the presence of structural integrity, and moderate to low for all other criteria. Methodological quality was high only for one study and moderate for three studies.

CONCLUSIONS

Twenty-six different criteria described by multiple classification systems have been identified for the magnetic resonance assessment of rotator cuff after repair. Reliability of most of them has not been analysed yet. With the data available, only the presence of structural integrity showed good intra- and inter-observer agreement.

LEVEL OF EVIDENCE

Systematic review of descriptive and qualitative studies, Level IV.

Full-thickness rotator cuff tears in patients younger than 55 years: clinical outcome of arthroscopic repair in comparison with older patients

PURPOSE

The purpose of this study was to examine whether younger patients had a similar response to repair of a full-thickness rotator cuff tear (RCT) as older patients.

METHODS

A secondary analysis was conducted of prospectively collected data of patients with full-thickness RCTs. Patients were categorized into patients <55 years of age and patients 55 and older. Patient-related outcome measures of disability at 2 years following surgery were the Short Western Ontario Rotator Cuff (Short WORC), American Shoulder and Elbow Surgeon's (ASES) assessment form, and absolute Constant-Murley score (ACMS).

RESULTS

Review of the database between 2001 and 2011 identified 344 patients (median age 62, range 24-90). Of these, 83 (24 %) patients were younger than 55 years of age (median age 48, range 24-54) and 261 (76 %) were in the older age group (median age 66, range 55-90). The median follow-up was 24 months (range 23-25). Patients in the younger age group had a higher prevalence of traumatic events (p = 0.02), had sustained more work-related injuries (p < 0.0001), and had a higher ratio of smaller tears (p = 0.0001). No difference was seen between groups with respect to post-operative scores of Short WORC, ASES, or ACMS. Pre-operative scores, having a work-related claim, increased tear size, and concomitant procedures affected the 2-year outcome scores.

CONCLUSION

This study shows that younger patients with full-thickness RCTs who undergo an arthroscopic repair do as well as older individuals regardless of the measure used to document their recovery.

LEVEL OF EVIDENCE

Retrospective outcome study, Level II.

Rotator cuff fatty infiltration and atrophy are associated with functional outcomes in anatomic shoulder arthroplasty

BACKGROUND

Shoulder arthroplasty provides reliable pain relief and restoration of function. However, the effects of fatty infiltration and atrophy in the supraspinatus and infraspinatus muscles on functional outcomes are not well understood.

QUESTIONS/PURPOSES

The purposes of this study were to (1) compare preoperative with postoperative fatty infiltration and atrophy of the supraspinatus and infraspinatus muscles after primary shoulder arthroplasty; and (2) identify any associations between these variables and outcome measures.

METHODS

A retrospective analysis was undertaken of 62 patients with a mean age of 67 years (range, 34-90 years) who underwent shoulder arthroplasty. CT scans were conducted preoperatively and at 12 months postoperatively. Outcome variables included the degree of supraspinatus and infraspinatus fatty infiltration (percent fatty infiltration and Goutallier grade), muscle area (percent muscle area and Warner atrophy grade), shoulder strength, and the Western Ontario Osteoarthritis Score (WOOS), American Shoulder and Elbow Surgeons score, and Constant outcome score.

RESULTS

Preoperatively, the mean percent fatty infiltration (FI) within the supraspinatus and infraspinatus was identical at 14%. One year after shoulder arthroplasty, both muscles had less fatty infiltration (6% and 7%, respectively; p<0.001). Similarly, the Goutallier grade significantly improved postoperatively for the supraspinatus (p=0.0037) and infraspinatus (p=0.0007). Conversely, measures of muscle atrophy remained unchanged postoperatively (p>0.251). Preoperatively, greater supraspinatus percent FI was negatively associated with preoperative shoulder strength (r=0.37, p=0.001) and Constant score (r=0.38, p=0.001). Postoperative infraspinatus percent FI was negatively associated with postoperative strength (r=0.3, p=0.021) and Constant score (r=0.3, p=0.04). Multivariable regression analysis of possible predictive factors demonstrated that preoperative supraspinatus percent muscle area (p=0.016) and the diagnosis of osteoarthritis (p=0.017) were associated with better followup WOOS scores, and preoperative supraspinatus strength was associated with postoperative strength (p=0.0024). Higher degrees of preoperative percent FI were not associated with worse patient-reported outcomes postoperatively.

CONCLUSIONS

Supraspinatus and infraspinatus fatty infiltration improves after shoulder arthroplasty, whereas muscle area remains unchanged. Although further study of these variables is required, the negative associations identified between preoperative supraspinatus atrophy and the diagnosis of rheumatoid arthritis and postoperative quality-of-life outcome scores may aid the clinician in selecting the best treatment option for glenohumeral arthrosis and in the management of patient expectations.

LEVEL OF EVIDENCE

Level III, prognostic study.

Does partial tear repair of adjacent tendons improve the outcome of supraspinatus tendonfull-thickness tear reinsertion?

BACKGROUND

Partial tearing of the infraspinatus and/or subscapularis tendon(s) is frequently associated with supraspinatus full-thickness tears. However, limited data regarding its influence on supraspinatus surgical repair is available.

PURPOSE

Our aim was to assess the functional and anatomical outcomes of open repair of supraspinatus full-thickness tears combined with adjacent partial tearing, comparatively to a control.

METHODS

We retrospectively identified 22 patients (22 shoulders) with a partial tear, most of them being a delamination tear, of the infraspinatus and/or subscapularis tendons associated with a complete detachment of the supraspinatus tendon. Twenty-seven patients (27 shoulders) treated for an isolated complete detachment of the supraspinatus tendon by open repair served as controls. The mean age was 58 years. A proximalized trans-osseous reinsertion of the supraspinatus tendon was combined with a curettage-closure of the delamination tear. Patients were evaluated with standardized MRI at last follow-up.

RESULTS

At a mean of 75-month follow-up, the presence of a partial tear of either infraspinatus or subscapularis, or both, did not influence function and healing rates of supraspinatus tendon repair. Conversely to the control, when a retear occurred, the functional score tended to worsen. Preoperatively, fatty muscular degeneration was more pronounced when a partial tear was present. Fatty degeneration worsened regardless of repair healing.

CONCLUSION

Open reinsertion of a supraspinatus full-thickness tear associated with a thorough treatment of partial tear of adjacent tendons led to optimal functional and anatomical mid term outcomes. Our results suggest the presence of a partial tear of adjacent tendons could be associated with poorer function in case of supraspinatus tendon re-rupture.

LEVEL OF EVIDENCE

Level III case-control study.

Is rotator cuff repair appropriate in patients older than 60 years of age? prospective, randomised trial in 103 patients with a mean four-year follow-up

BACKGROUND

The objective of this randomised trial was to compare surgical rotator cuff repair to simple decompression by acromioplasty and biceps tenotomy in patients older than 60 years of age with a mean follow-up of 4 years.

HYPOTHESIS

Tendon repair produces better functional outcomes than simple decompression and prevents progression towards cuff tear arthropathy in the longer term.

PATIENTS AND METHOD

Of 130 initially included patients older than 60 years of age and having rotator cuff tears deemed amenable to surgical repair, 103 (79%) were evaluated after a mean of 4 years. These patients had been randomly allocated to acromioplasty and tenotomy (AT group, n=49) or to acromioplasty, tenotomy, and tendon suture (CR group, n=54). The tear was distal in 41 patients, intermediate in 40, and retracted in 22. At last follow-up, the evaluation included the clinical Constant's Score, radiographs and, in the CR group, ultrasonography.

RESULTS

The complication rate was 4%. The mean Constant Score was 44 preoperatively; values after 4 years were 76 overall (P=0.01), 78 in the CR group, and 73 in the AT group (P=0.01). The tendon-healing rate as assessed using ultrasonography was 63%. The Constant Score was significantly better when tendon healing was achieved (82/73, P<0.001). In the AT group, the acromio-humeral distance was significantly shorter (6.9 mm/7.8mm, P=0.03) and eccentric humeral head position was more common (44%/26%, P=0.01).

DISCUSSION

Arthroscopic rotator cuff repair provides better functional outcomes than does simple decompression in patients older than 60 years and prevents cuff tear arthropathy with eccentric humeral head position in the medium term. Tendon healing is the main determinant of outcomes after rotator cuff repair.

LEVEL OF EVIDENCE

II, randomised trial.

Does preoperative subscapularis fatty muscle infiltration really matter in anterosuperior rotator cuff tears repair outcomes? A prospective multicentric study

INTRODUCTION

Anterosuperior (AS) rotator cuff tear describes a combined tear of the subscapularis and the supraspinatus tendons. We hypothesized that results after AS tendon repairs might be influenced by the size of the subscapularis rupture and the preoperative subscapularis muscle fatty infiltration.

METHODS

A prospective multicentric study of 53 AS rotator cuff tears from five centers was performed (January 2008-January 2009). Subscapularis tendon retraction and fatty infiltration were assessed preoperatively. An ultrasonographic healing control was performed 1 year after surgery.

RESULTS

Patients were on average 60 years (range, 43-75 years) and were operated on average 16 months (range, 2-72 months) after the beginning of their symptoms. The incidence of AS tears was found to be 18%. Average follow-up was 15 months (range, 12-24). The Constant-Murley (CM) score for the patients with AS ruptures improved significantly from 49 points (range, 35-51 points) preoperatively to 73 points postoperatively (range, 50-95 points)(P=0.0205). CM score gains were 26 for Lafosse group 1 ruptures and 29 for Lafosse group 2 & 3 with pre- and postoperative P values at P<0.0000001 and P<0.000001, respectively. The last follow-up CM score according to the subscapularis fatty infiltration was 70 (range, 48-95) for groups 0-1, 70 (range, 56-87) for group 2, and 56 (range, 53-88) for groups 3-4 with pre- and postoperative P values at P<0.001, P<0.001, and P<0.004, respectively. The global retear rate was 6%.

DISCUSSION

Our study showed that the CM score after repairs of AS rotator cuff tears was lower in advanced subscapularis fatty infiltration. However, gains in CM scores were similar whatever the initial subscapularis fatty infiltration. The rate of tendon healing was correlated with subscapularis fatty infiltration. Subscapularis tendon rupture size was not significantly correlated with outcomes.

LEVEL OF EVIDENCE

Level III.

Fatty infiltration of the shoulder: diagnosis and reversibility

Fatty degeneration is a degenerative condition of the tendon-muscle unit of rotator cuff muscles, characterized by atrophy of muscle fibers, fibrosis, and fatty accumulation within and around the muscles. Many classification may be useful to stage this pathology, especially on Computed Tomography (CT) and magnetic resonance imaging (Mari) findings. Stem cell-based therapies for repair and regeneration of tendons and muscles may be used to promote healing and to make this condition reversible. Diagnosis and management of this condition is mandatory as in patients undergoing rotator cuff repair, it may influence outcomes, increase the likelihood of re-tearing, and evolve negatively.

Pullout strength of all suture anchors in the repair of rotator cuff tears: a biomechanical study

PURPOSE

We evaluated the biomechanical strength of two all suture anchors (ASA) of reduced diameter (1.4 mm) and compared them with the standard screw anchor (SA) with larger diameter (5.5 mm) used in rotator cuff tears.

METHODS

We conducted 30 uniaxial vertical pullout tests using Material Testing System Instron 5566A until failure of the anchorage defined as rupture of the threads or anchor or detachment of the anchor. Anchor fixation was on tuberosities of fresh bovine humerus bone. ASAs were spaced four millimetres apart and were compared with a control SA implanted on the same greater tubercle at two centimetres. The tests were all performed at room temperature in a dry environment. Tensile loads (10 mm/min) were applied parallel to the axis of insertion. A preloading of 10 N was used to overcome loading artifacts of the test sample at the beginning of the test.

RESULTS

Student's t test showed no statistically significant difference between anchors in terms of load to failure (ASA: force 265.06 ± 87.25 N versus SA : 325.35 ± 113.46 N; p = 0.09) and mean elongation at rupture (ASA : 23 ± 7 mm versus SA : 21 ± 6 mm; p = 0.46).

CONCLUSIONS

In vitro, this experimental study showed no statistically significant difference in pullout strength and displacement between ASA and SA at a chosen level of significance (p < 0.05).

Open repair of isolated traumatic subscapularis tendon tears with a synthetic soft tissue reinforcement

BACKGROUND

Missed or chronic subscapularis tendon ruptures may have muscle atrophy and tendon retraction resulting in a large defect with high risk of re-tear after a surgical repair. To improve the clinical results of this challenging surgery, the repaired tendon could be augmented with endogenous or exogenous materials. The purpose of this study was to evaluate the structural tendon integrity and clinical outcomes after an open subscapularis tendon repair with a synthetic soft tissue reinforcement.

MATERIALS AND METHODS

Ten patients were managed with an open repair of the subscapularis tendon with augmentation by means of SportMesh, a readily available synthetic degradable poly(urethaneurea) scaffold. Clinical findings were assessed for all patients preoperatively and postoperatively with use of the visual analog scale for pain and the DASH scoring system. All patients had an ultrasonographic study at the latest follow-up.

RESULTS

The visual analog scale for pain (mean ± standard deviation) improved significantly (P < 0.01) from 7.9 ± 1.1 preoperatively to 1.95 ± 1.85 at the latest clinical follow-up evaluation. The mean DASH score at the latest clinical follow-up was 12.63 %. Ultrasound imaging revealed a structural intact repair at follow-up in 9 shoulders (90 %) with average 5.4 mm in thickness (4.3 mm in the contralateral healthy side).

CONCLUSIONS

At a median follow-up of 23 months, 80 % (8 of 10) of patients had a good or excellent result after an open subscapularis tendon repair with a soft tissue reinforcement. As a synthetic material, SportMesh Soft Tissue Reinforcement eliminates the risk of collagen reactions, which may result from collagen or dermis patches. Although the follow-up is relatively short, our series shows a promising durable repair with a 10 % re-tear rate at an average of 23 postoperative months. Level of evidence Case Series, Treatment Study, Level IV.