Objectives . The effects of disease progression and common tendinopathy treatments on the tissue characteristics of human rotator cuff tendons have not previously been evaluated in detail owing to a lack of suitable sampling techniques. This study evaluated the structural characteristics of torn human supraspinatus tendons across the full disease spectrum, and the short-term effects of subacromial corticosteroid injections (SCIs) and subacromial decompression (SAD) surgery on these structural characteristics. . Methods . Samples were collected inter-operatively from supraspinatus tendons containing small, medium, large and massive full thickness tears (n = 33). Using a novel minimally invasive biopsy technique, paired samples were also collected from supraspinatus tendons containing partial thickness tears either before and seven weeks after subacromial SCI (n = 11), or before and seven weeks after SAD surgery (n = 14). Macroscopically normal subscapularis tendons of older patients (n = 5, mean age = 74.6 years) and supraspinatus tendons of younger patients (n = 16, mean age = 23.3) served as controls. Ultra- and micro-structural characteristics were assessed using atomic force microscopy and polarised light microscopy respectively. . Results. Significant structural differences existed between torn and control groups. Differences were identifiable early in the disease spectrum, and increased with increasing tear size. Neither SCI nor SAD surgery altered the structural properties of partially torn tendons seven weeks after treatment. . Conclusions . These findings may suggest the need for early clinical intervention strategies for torn rotator cuff tendons in order to prevent further degeneration of the tissue as tear size increases. Further work is required to establish the long-term abilities of SCI and SAD to prevent, and even reverse, such degeneration. Cite this article: Bone Joint Res 2014;3:252–61

We examined macroscopically and microscopically 55 cadaver rotator-cuff tendons attached to their humeral heads to determine the distance between the edge of the articular cartilage and the tendon insertion of the supraspinatus (the width of the sulcus) and the score of regressive changes at the sulcus. In 33 specimens we measured the tensile strength. The width of the sulcus was correlated with the score of regressive changes and with the ultimate tensile strength of the supraspinatus tendon. The width of the sulcus correlated positively with the score of regressive changes (r = 0.66, p < 0.0001), but there was a negative correlation between the latter and the ultimate tensile strength (r = −0.81, p = 0.001) and between the width of the sulcus and the ultimate tensile strength (r = −0.74, p = 0.004). We believe that the width of the sulcus is a simple and useful clinical indicator of the integrity and the tensile strength of the supraspinatus tendon

Aims. Rotator cuff tear (RCT) is the leading cause of shoulder pain, primarily associated with age-related tendon degeneration. This study aimed to elucidate the potential differential gene expressions in tendons across different age groups, and to investigate their roles in tendon degeneration. Methods. Linear regression and differential expression (DE) analyses were performed on two transcriptome profiling datasets of torn supraspinatus tendons to identify age-related genes. Subsequent functional analyses were conducted on these candidate genes to explore their potential roles in tendon ageing. Additionally, a secondary DE analysis was performed on candidate genes by comparing their expressions between lesioned and normal tendons to explore their correlations with RCTs. Results. We identified 49 genes in torn supraspinatus tendons associated with advancing age. Among them, five age-related genes showed DE in lesioned tendons compared to normal tendons. Functional analyses and previous studies have highlighted their specific enrichments in biological functions, such as muscle development (e.g. myosin heavy chain 3 (MYH3)), transcription regulation (e.g. CCAAT enhancer binding brotein delta (CEBPD)), and metal ion homeostasis (e.g. metallothionein 1X (MT1X)). Conclusion. This study uncovered molecular aspects of tendon ageing and their potential links to RCT development, offering insights for targeted interventions. These findings enhance our understanding of the mechanisms of tendon degeneration, allowing potential strategies to be made for reducing the incidence of RCT. Cite this article: Bone Joint Res 2024;13(9):474–484

The purpose of this study was to clarify the effect of delay of the reattachment of the supraspinatus tendon into a bony trough to the strength of the repaired tendon-bone complex. The supraspinatus tendon of rabbits were transected and reattached into bony troughs at the greater tuberosity immediately and six weeks after transection. The tensile strength of the tendon-bone complex, harvested twelve weeks after reattachment, were measured. The tensile strength showed no difference between immediate and delayed reattached shoulders. Six weeks delay of supraspinatus tendon repair seems not to weaken the tensile strength of repaired tendon-bone complex. The purpose of this study was to clarify the effect of timing of surgery on the strength of the supraspinatus tendon-bone complex after the reimplantation of the tendon into a bony trough. In eight rabbits, the supraspinatus tendon was transected and reinserted into a bony trough at the greater tuberosity (early reattachment group). In seven rabbits, the supraspinatus tendon was reinserted six weeks after transection (delayed reattachment group). In both groups, the rabbits were sacrificed twelve weeks after reattachment, and the tensile strength of the tendon-bone complex was measured. The contralateral shoulders served as controls. None of the operated tendons failed at the site of reimplantation. The ratio of tensile strength of the operated tendon-bone complex to the controls showed no difference between two groups (Immediate reattachment group: 79.9± 1 S.E. 16.5%, delayed reattachment group: 80.4± 12.6%, P> 0.05). This is the first experimental study to compare the tensile strength of supraspinatus tendon-bone complex repaired after different time intervals. Stress-shielded tendon & bone tend to decrease their tensile strength. Given the six weeks duration of detachment, a weaker tensile strength of delayed reattachment group was expected than of the early reattachment group. The fact that both groups did not show a difference might be due to the recovery of tensile strength of tendon & bone in twelve weeks after reattachment. Six weeks delay of repair of supraspinatus tendon does not weaken the tensile strength of repaired tendon-bone complex. Fundings This study has been supported in part by a grant from the American Shoulder and Elbow Surgeons

Aims: The aim of this study was to analyze the morphological features of the human surgical specimens of normal supraspinatus tendon from patients with rotator cuff tears and glenohumeral instability. Methods: 41 subjects were recruited for the study. 20 subjects (group 1) sustained a rotator cuff tear and proceeded arthroscopic repair of the lesion. 21 subjects (group 2) underwent surgery due to glenohumeral instability. During surgery, under arthroscopic control, a full thickness supraspinatus tendon biopsy was harvested in the middle portion of the tendon. All slices were processed for histological analysis. Results: On surgical specimens of supraspinatus tendon from patients with rotator cuff tears, but not from patients with instability, we found increased preponderance of hyaline degeneration, fibrocartilaginous or chondroid metaplasia, calcification, lipoid degeneration, mucoid or myxoid. Degenerative changes were more evident on the articular side of the rotator cuff. Conclusions: The present study provides a description of the histological architecture of human surgical specimens of normal supraspinatus tendon from patients with rotator cuff tears. Preexisting degenerative change in the supraspinatus tendon seems to be the main cause of rotator cuff tears

We hypothesised that diet-induced obesity (DIO) would result in inferior enthesis healing in a rat model of rotator cuff (RC) repair and that dietary intervention in the peri-operative period would improve enthesis healing. A total of 78 male Sprague-Dawley rats were divided into three weight-matched groups from weaning and fed either: control diet (CD), high-fat diet (HFD), or HFD until surgery, then CD thereafter (HF-CD). After 12 weeks, the left supraspinatus tendon was detached, followed by immediate surgical repair. At 2 and 12 weeks post-surgery, animals were culled, and RCs harvested for biomechanical and histological evaluation. Body composition and metabolic markers were assessed via DEXA and plasma analyses, respectively. DIO was established in the HFD and HF-CD groups before surgery and subsequently reversed in the HF-CD group after surgery. Histologically, the appearance of the repaired entheses was poorer in both the HFD and HF-CD groups compared with the CD group at 12 weeks after surgery, with semiquantitative scores of 6.2 (P<0.01), 4.98 (P<0.01), and 8.7 of 15, respectively. The repaired entheses in the HF-CD group had a significantly lower load to failure (P=0.03) at 12 weeks after surgery compared with the CD group, while the load to failure in the HFD group was low but not significantly different (P=0.10). Plasma leptin were negatively correlated with histology scores and load to failure at 12 weeks after surgery. DIO impaired enthesis healing in this rat RC repair model, with inferior biomechanical and histological outcomes. Restoring normal weight with dietary change after surgery did not improve healing outcomes. Circulating levels of leptin significantly correlated with poor healing outcomes. This pre-clinical rodent model demonstrates that obesity is a potentially modifiable factor that impairs RC healing and increases the risk of failure after RC surgery

Differential strain has been proposed to be a causative factor in failure of the supraspinatus tendon. We quantified the strains on the joint and bursal sides of the supraspinatus tendon with increasing load (20 to 200 N) and during 120° of glenohumeral abduction with a constant tensile load (20 to 100 N). We tested ten fresh frozen cadaver shoulders on a purpose-built rig. Differential variable reluctance extensometers allowed calculation of the strain. Static loading to 100 N or more increased strains on the joint side significantly more than on the bursal side. During glenohumeral abduction an increasing and significant difference in strain was measured between the joint and bursal sides of the supraspinatus tendon, which reached a maximum of 10.6% at abduction of 120°. The joint side strain of 7.5% reached values which were previously reported to cause failure. Differential strain causes shearing between the layers of the supraspinatus tendon, which may contribute to the propagation of intratendinous defects that are initiated by high joint side strains

Obesity is associated with poor outcomes and increased risk of failure after rotator cuff (RC) repair surgery. The effect of diet-induced obesity (DIO) on enthesis healing has not been well characterised and whether its effects can be reversed with dietary intervention is unknown. We hypothesised that DIO would result in inferior enthesis healing in a rat model of RC repair and that dietary intervention in the peri-operative period would improve enthesis healing. A total of 78 male Sprague-Dawley rats were divided into three weight-matched groups from weaning and fed either: control diet (CD), high-fat diet (HFD), or HFD until surgery, then CD thereafter (HF-CD). After 12 weeks the left supraspinatus tendon was detached, followed by immediate surgical repair. At 2 and 12 weeks post-surgery, animals were cullers and RCs harvested for biomechanical and histological evaluation. Body composition and metabolic markers were assessed via DEXA and plasma analyses, respectively. DIO was established in the HFD and HF-CD groups prior to surgery, and subsequently reversed in the HF-CD group after surgery. At 12 weeks post-surgery, plasma leptin concentrations were higher in the HFD group compared to the CD group (5.28 vs. 2.91ng/ml, P=0.003). Histologically, the appearance of the repaired entheses was poorer in both the HFD and HF-CD compared to the CD group at 12 weeks (overall histological score 6.20 (P=0.008), 4.98 (P=0.001) and 8.68 out of 15, respectively). The repaired entheses in the HF-CD group had significantly lower (26.4 N, P=0.028) load-at-failure 12 weeks post-surgery compared to the CD group (34.4 N); while the HFD group was low, but not significantly different (28.1 N, P=0.096). Body mass at the time of surgery, plasma leptin and body fat percentage were negatively correlated with histological scores and plasma leptin with load-at-failure 12 weeks post-surgery. DIO impaired enthesis healing in this rat RC repair model, with inferior biomechanical and histological outcomes. Restoring normal weight with dietary change after surgery did not improve healing outcomes. Exploring interventions that improve the metabolic state of obese patients and counselling patients appropriately about their modest expectations after repair should be considered

To quantify the variation in strain between the deep and superficial layers of the supraspinatus tendon, ten cadaveric shoulders were tested on a purpose built rig. Differential Variable Reluctance Transducers (DVRTs) were inserted into the superficial and deep aspects of the tendon spanning the critical zone. DVRTs accurately measured linear displacement and from this strain was calculated. The strain was measured for two aspects of supraspinatus action, abduction from 0 to 120 degrees with a tensile load (100 Newtons) and static load increases at zero abduction (20, 50, 100, 150 and 200 Newtons). After preconditioning, ten sets of results were recorded for each load/position. The hypothesis, there is a statistically significant difference in strain between the superficial/deep supraspinatus tendon during abduction and with static loading, was tested using a one way ANOVA. During abduction a statistically significant difference in strain was measured between the layers of the supraspinatus tendon at thirty degrees (p=0.000428) and this increased with further abduction. Tensile loading increased tendon strain more in the deep layer of the tendon. This was statistically significant at loads greater than 150N (p= 0.007). The variation in properties between the superficial and deep layers of the supraspinatus tendon has been proposed as a cause of differential strain (1). This study confirms statistically different strains between the superficial and deep tendon layers. It is proposed that the resulting shearing effect initiates intratendinous defects and ultimately tears

Excessive apoptosis has been found in torn supraspinatus tendon1 and mechanically loaded tendon cells2. Following oxidative and other forms of stress, one family of proteins that is often unregulated are Heat Shock Proteins (HSPs). The purpose of this study was to determine if HSPs were unregulated in human and rat models of tendinopathy and to determine if this was associated with increased expression of regulators of apoptosis (cFLIP, Caspases 3& 8). A running rat supraspinatus tendinopathy overuse model 3 was used with custom microarrays consisting of 5760 rat oligonucleotides in duplicate. Seventeen torn supraspinatus tendon and matched intact subscapularis tendon samples were collected from patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from ten patients undergoing arthroscopic stabilisation surgery and evaluated using semiquantative RT-PCR and immunohistochemistry. Rat Microarray: Upregulation of HSP 27 (×3.4) & 70 (×2.5) and cFLIP (×2.2) receptor was noted in degenerative rat supraspinatus tendon subjected to daily treadmill running for 14 days compared to tendons of animals subject to cage activity only. Histological analysis: All torn human supraspinatus tendons exhibited changes consistent with marked tendinopathy. Matched subscapularis tendon showed appearances of moderate-advanced degenerative change. Apoptosis mRNA expression: The expression levels of caspase 3 & 8 and HSPs 27 & 70 were significantly higher in the torn edges of supraspinatus when compared to matched subscapularis tendon and control tendon (p< 0.01). cFLIP showed significantly greater (p< 0.001) expression in matched subscapularis compared to supraspinatus and control tendon. Immunohistochemical analysis: cFLIP, Caspase 3 & 8 and HSP 27 and 70 was confirmed in all samples of torn supraspinatus tendon. Significantly increased immunoactivity of Caspase 3& 8 and HSP 27 & 70 were found in torn supraspinatus (p< 0.001) compared to matched and normal subscapularis. The proteins were localized to tendon cells. The finding of significantly increased levels of Heat Shock Proteins in human and rat models of tendinopathy with the co-expression of other regulators of apoptosis suggests that Heat Shock Proteins play a role in the cascade of stress activated-programmed cell death and degeneration in tendinopathy

Aim: The purpose of this study was to evaluate the cytokine molecules present in a rat tendinopathy model and in the torn edge of human rotator cuff tendon in an attempt to understand their role in tendon degeneration. Methods: A rat tendon overuse model was used with custom microarrays consisting of 5760 rat oligonucleotide features in duplicate. Seventeen torn supraspinatus tendon and matched intact subscapularis tendon samples were collected from patients undergoing arthroscopic shoulder surgery.Control samples of subscapularis tendon were collected from ten patients undergoing arthroscopic stabilisation surgery.Specimens were analysed for the presence of interleukins 18, 15, 12, 11, 6, 2, macrophage inhibitory factor (MIF), and tumour necrosis factor ƒÑ by semiquantitative RT-PCR and immunohistochemistry. Tendinopathy was assessed on a basic histological scale. Results: Rat Microarray analysis: Upregulation of IL-6, IL-11 and IL18 receptor was noted in the degenerated rat supraspinatus tendon. Downregulation of IL-2 was noted. No other cytokine signal was expressed. Histological analysis: All torn human supraspinatus tendons changes consistent with marked tendinopathy. Matched subscapularis tendon showed appearances of moderate-advanced degenerative change. Cytokine mRNA expression: TNF-£\ mRNA expression was found to be significantly elevated (p< 0.01) in subscapularis tendon compared to torn supraspinatus samples. The expression levels of IL-18, IL-15, IL-6 and MIF was significantly higher in the torn edges of supraspinatus when compared to matched subscapularis tendon and normal control tendon (p< 0.001). Immunohistochemical analysis: Presence of IL-18, IL-15, Il-6, MIF and TNF-£\ was confirmed in all samples of torn supraspinatus tendon. Significantly increased levels of IL-18, IL-15, IL-6 and MIF were found in torn supraspinatus. (p< 0.01) compared to matched and normal subscapularis. Conclusions: Cytokines have been shown to promote the intensive production of reactive O2 metabolites . 1. and are potent agonists of protein kinases . 2. Our finding of significantly increased cytokine levels may suggest that these molecules when expressed during the degenerate and healing phases of tendon injury result in the subsequent production of reactive O2 species and protein kinases. 3. causing tendon damage or failure of the normal reparative process. Our finding of marked tendinopathy in matched subscapularis tendon may also provide a useful human tendinopathy model

The rotator cuff tendinopathy is one of the most common shoulder problems leading to full-thickness rotator cuff tendon tear and, eventually, to degenerative arthritis. Recent research on rotator cuff tendon degeneration has focused on its relationship to cell death. The types of cell death known to be associated with rotator cuff tendon degeneration are apoptosis, necrosis, and autophagic cell death. The increased incidence of cell death in degenerative tendon tissue may affect the rates of collagen synthesis and repair, possibly weakening tendon tissue and increasing the risk of tendon rupture. The biomolecular mechanisms of the degenerative changes leading to apoptotic cell death in rotator cuff tenofibroblasts have been identified as oxidative-stress-related cascade mechanisms. Furthermore, apoptosis, necrosis, and autophagic cell death are all known to be mediated by oxidative stress, a condition in which ROS (reactive oxygen species) are overproduced. Lower levels of oxidative stress trigger apoptosis; higher levels mediate necrosis. Although the signaltransduction pathway leading to autophagy has not yet been fully established, ROS are known to be essential to autophagy. A neuronal theory regarding rotator cuff degeneration has been developed from the findings that glutamate, a neural transmitter, is present in increased concentrations in tendon tissues with tendinopathy and that it induces rat supraspinatus tendon cell death. Recent studies have reported that hypoxia involved in rotator cuff tendon degeneration. Because antioxidants are known to scavenge for intracellular ROS, some studies have been conducted to determine whether antioxidants can reduce cell death in rotator cuff tendon-origin fibroblasts. The first study reported that an antioxidant has the ability to reduce apoptosis in oxidative-stressed rotator cuff tenofibroblasts. The second study reported that antioxidants have both antiapoptotic effects and antinecrotic effects on rotator cuff tendon-origin fibroblasts exposed to an oxidative stimulus. The third study reported that an antioxidant has antiautophagic-cell-death effects on rotator cuff tendon-origin fibroblasts exposed to an oxidative stimulus. The fourth study reported that glutamate markedly increases cell death in rotator cuff tendonorigin fibroblasts. The glutamate-induced cytotoxic effects were reduced by an antioxidant, demonstrating its cytoprotective effects against glutamate-induced tenofibroblast cell death. The fifth study reported that hypoxia significantly increases intracellular ROS and apoptosis. The hypoxia-induced cytotoxic effects were markedly attenuated by antioxidants, demonstrating their cytoprotective effects against hypoxia-induced tenofibroblast cell death. In conclusion, antioxidants have cytoprotective effects on tenofibroblasts exposed in vitro to an oxidative stressor, a neurotransmitter, or hypoxia. These cytoprotective effects result from antiapoptotic, antinecrotic, and antiautophagic actions involving the inhibition of ROS formation. These findings suggest that antioxidants may have therapeutic potential for rotator cuff tendinopathy. Further studies must be conducted in order to apply these in vitro findings to clinical situations

Purpose: Partial rotator cuff tears are a frequent source of shoulder pain. At times, diagnosis is difficult and treatment unsuccessful. Historical treatment has involved open debridement when conservative treatment has failed. The purpose of this study was to evaluate the results of arthroscopic treatment of deep partial thickness tears of the supraspinatus tendon in patients over 40 years and to assess the healing radiographically. Method: Forty-nine patients (mean age: 55 years) underwent treatment of a deep partial thickness tear of the supraspinatus tendon. Exclusion criteria: age < 40 years, associated instability, posterosuperior impingement or previous shoulder surgery. Patients were re-examined with a mean 32 months follow-up. For lesions involving less than 50% of the tendon thickness, an acromioplasty and either a debridement (n=39) or a side-to-side repair (n=3) was performed. For lesions involving greater than 50% of the tendon thickness (n=7), an acromioplasty and a trans-osseous repair was performed after completion of the tear. Twenty patients (41%) had an assessment of tendon healing by CT arthrogram, MRI or MR arthrogram, at a minimum 12 months post-operatively. Results: Results were good or excellent in 90% of patients, and 94% were satisfied. The Constant score improved from 56 to 82 points (p< 0.0001) and the UCLA score improved from 15 to 30 points (p< 0.0001). Of the 31 patients employed preoperatively, three did not return to work; an occupational injury was predictive of a lower Constant score (p=0.02). Four out of 13 (31%) cases involving less than 50% of the tendon thickness healed and all cases (n=7) involving greater than 50% had healed. Conclusion: Patients over 40 years with an isolated deep partial thickness tear of the supraspinatus tendon benefited both subjectively and objectively from arthroscopic intervention. For deep tears involving < 50% of the tendon thickness, resolution of pain and return to work is possible after acromioplasty and debridement. For deeper tears, completion of the tendon and reattachment to the greater tuberosity enables tendon healing

Treatment of massive rotator cuff tears can be challenging. Previous studies with irreparable rotator cuff tears showed good clinical results of tendon healing with the arthroscopic insertion of a protective biodegradable spacer balloon filled with saline solution between the repaired tendon and the acromion [1,2], but so far no scientific evidence has showed how the device alters pressures over the repaired tendon. This biomechanical study investigated the effects of a spacer inserted in the subacromial space on pressures over the repaired rotator cuff tendon in passive motion cycles typical for post-operative rehabilitation routines. Six human cadaveric shoulders were prepared with the humerus cut 15cm below the joint and embedded in a pot, while the scapula fixed at three points on a plate. A rotator cuff tear was simulated and repaired using a suture anchor and a Mason-Allen suture. The specimens were then mounted on a custom-made pneumatic testing rig to induce passive motion cycles of adduction-abduction (90–0°) and flexion-extension (0–40°) with constant glenohumeral and superior loads and tension is exerted on the supraspinatus tendon with weights. A pressure sensor was placed between the supraspinatus tendon and the acromion. After pressure measurements for 15 cycles of each motion type, the InSpace balloon (OrthoSpace, Inc, Israel) was inserted and the specimens tested and pressure measured again for 15 cycles. Statistically significant changes in peak pressures were then measured before and after balloon. Peak pressures were measured near 90 degrees abduction. No statistical differences were observed for internal-external rotation before and after balloon-shaped subacromial spacer was inserted. Mean pressures in abduction-adduction were significantly reduced from 121.7 ± 9.5 MPa to 51.5 ± 1.2 MPa. Peak pressures after repair were 1171.3 ± 99.5 MPa and 1749.6 ± 80.7 MPa in flexion-extension and abduction-adduction motion, respectively, and significantly decreased to 468.7 ± 16.0 MPa and 535.1 ± 27.6 MPa after spacer insertion (p<0.0001). The use of the spacer above the repaired tendon reduced peak pressures and distributed them more widely over the sensor during both abduction-adduction and flexion-extension motions and therefore can reduce the stress on the rotator cuff repair. The InSpace system may reduce the pressure on the repaired tendon, thus potentially protecting the repair. Further studies to investigate this phenomenon are warranted, in particular relating these changes to shoulder kinematics following tear repair and spacer insertion

We have compared three different methods of treating symptomatic non-traumatic tears of the supraspinatus tendon in patients above 55 years of age. A total of 180 shoulders (173 patients) with supraspinatus tendon tears were randomly allocated into one of three groups (each of 60 shoulders); physiotherapy (group 1), acromioplasty and physiotherapy (group 2) and rotator cuff repair, acromioplasty and physiotherapy (group 3). The Constant score was assessed and followed up by an independent observer pre-operatively and at three, six and twelve months after the intervention. Of these, 167 shoulders were available for assessment at one year (follow-up rate of 92.8%). There were 55 shoulders in group 1 (24 in males and 31 in females, mean age 65 years (55 to 79)), 57 in group 2 (29 male and 28 female, mean age 65 years (55 to 79)) and 55 shoulders in group 3 (26 male and 29 female, mean age 65 years (55 to 81)). There were no between-group differences in the Constant score at final follow-up: 74.1 (. sd. 14.2), 77.2 (. sd. 13.0) and 77.9 (. sd. 12.1) in groups 1, 2 and 3, respectively (p = 0.34). The mean change in the Constant score was 17.0, 17.5, and 19.8, respectively (p = 0.34). These results suggest that at one-year follow-up, operative treatment is no better than conservative treatment with regard to non-traumatic supraspinatus tears, and that conservative treatment should be considered as the primary method of treatment for this condition. Cite this article: Bone Joint J 2014;96-B:75–81

The role of inflammatory cells and their products in tendinopathy is not completely understood. Pro-inflammatory cytokines are upregulated after oxidative and other forms of stress. Based on observations that increased cytokine expression has been demonstrated in cyclically-loaded tendon cells we hypothesised that because of their role in oxidative stress and apoptosis, pro-inflammatory cytokines may be present in rodent and human models of tendinopathy. A rat supraspinatus tendinopathy model produced by running overuse was investigated at the genetic level by custom micro-arrays. Additionally, samples of torn supraspinatus tendon and matched intact subscapularis tendon were collected from patients undergoing arthroscopic shoulder surgery for rotator-cuff tears and control samples of subscapularis tendon from ten patients with normal rotator cuffs undergoing arthroscopic stabilisation of the shoulder were also obtained. These were all evaluated using semiquantitative reverse transcription polymerase chain-reaction and immunohistochemistry. We identified significant upregulation of pro-inflammatory cytokines and apoptotic genes in the rodent model (p = 0.005). We further confirmed significantly increased levels of cytokine and apoptotic genes in human supraspinatus and subscapularis tendon harvested from patients with rotator cuff tears (p = 0.0008). These findings suggest that pro-inflammatory cytokines may play a role in tendinopathy and may provide a target for preventing tendinopathies

Critical shoulder angle (CSA), lateral acromial angle (LAA), and acromion index (AI) are common radiologic parameters used to distinguish between patients with rotator cuff tears (RCT) and those with an intact rotator cuff. This study aims to assess the predictive power of these parameters in degenerative RCT. This retrospective study included data from 92 patients who were divided into two groups: the RCT group, which included 47 patients with degenerative full-thickness supraspinatus tendon tears, and a control group of 45 subjects without tears. CSA, AI, and LAA measurements from standardized true anteroposterior radiographs were independently derived and analyzed by two orthopedic surgeons. Receiver operating characteristic (ROC) analyses were performed to determine the cutoff values. No significant differences were found between patients in the RCT and control groups in age (p = 0.079), gender (p = 0.804), or injury side (p = 0.552). Excellent inter-observer reliability was seen for CSA, LAA, and AI values. Mean CSA (38.1°) and AI (0.72) values were significantly larger in the RCT group than in the control group (34.56° and 0.67°, respectively, p < 0.001) with no significant difference between groups for LAA (RCT, 77.99° vs. control, 79.82°; p = 0.056). ROC analysis yielded an area under the curve (AUC) of 0.815 for CSA with a cutoff value of 37.95°, and CSA was found to be the strongest predictor of the presence of a RCT, followed by AI with an AUC of 0.783 and a cutoff value of 0.705. We conclude that CSA and AI may be useful predictive factors for degenerative RCT in the Turkish population

We compared time-dependent changes in the biomechanical properties of single-and double-row repair of a simulated acute tear of the rotator cuff in rabbits to determine the effect of the fixation techniques on the healing process. A tear of the supraspinatus tendon was created in 80 rabbits which were separated into two equal groups. A single-row repair with two suture anchors was conducted in group 1 and a double-row repair with four suture anchors in group 2. A total of ten intact contralateral shoulder joints was used as a control group. Biomechanical testing was performed immediately post-operatively and at four and eight weeks, and histological analysis at four and eight weeks. The mean load to failure in group 2 animals was greater than in group 1, but both groups remained lower than the control group at all intervals. Histological analysis showed similar healing properties at four and eight weeks in both groups, but a significantly larger number of healed tendon-bone interfaces were identified in group 2 than in group 1 at eight weeks (p < 0.012). The ultimate load to failure increased with the number of suture anchors used immediately post-operatively, and at four and eight weeks. The increased load to failure at eight weeks seemed to be related to the increase in the surface area of healed tendon-to-bone in the double-row repair group

Antegrade intramedullary nailing of fractures of the shaft of the humerus is reported to cause impairment of the shoulder joint. We have reviewed 33 patients with such fractures to assess how many had injuries to the ipsilateral shoulder. All had an MR scan of the shoulder within 11 days of injury. The unaffected shoulder was also scanned as a control. There was evidence of abnormality in 21 of the shoulders (63.6%) on the injured side; ten had bursitis of the subacromial space, five evidence of a partial tear of the rotator cuff, one a complete rupture of the supraspinatus tendon, four inflammatory changes in the acromioclavicular joint and one a fracture of the coracoid process. These injuries may contribute to pain and dysfunction of the shoulder following treatment, and their presence indicates that antegrade nailing is only partly, if at all, responsible for these symptoms

Purpose of this study is to create an experimental model on rats for EMG evaluation of the supraspinatus muscle after traumatic rupture of its tendon. The population of this study consisted of 5 male rats of 300–400g. Under general anaesthesia we proceeded with traumatic rupture of the supraspinatus tendon and exposure of the muscle. The electrode of a stimulator was placed under suprascapular nerve and the supraspinatus tendon was sutured on a transducer for digital record of the produced signal. Initially we found the resting length and the electric intensity for higher muscle contracture. The parameters that were evaluated after single contracture (single twitch) were strength, time to peak, half relaxation time. Furthermore, it was evaluated the strength of tetanic contractures at 10,20,40,80,100 Hz (Stimulation for 350msec each time).Finally it was evaluated the muscle fatigue with stimulation at 40Hz for 250msec and total duration of 3 minutes. Fatigue index was calculated according to the decrease of titanic muscle contracture (Initial value-Final Value/Initial Value x 100). Our results are presented in mean ± sd. The single twitch was 8.2(5.1),the time to peak 0.034(0.02) msec, the half relaxation time 0.028(0.008)msec. The strength of titanic muscle contractures was 5.7msec at 10Hz and 17.7 at 100Hz. Finally the fatigue index was calculated at 48.4. We believe that EMG evaluation of the supraspinatus muscle in rats will help us understanding the pathology of muscle atrophy after rotator cuff tears and possibly the functional restoration after cuff repair

In this prospective study of partial articular supraspinatus tendon avulsion (PASTA) lesions treated arthroscopically by an ‘all inside’ method, 12 patients (nine men and three women) with a mean age of 31 years (22 to 36) were followed up for a mean of 16 months (8 to 32). The deep partial rotator cuff tears were usually viewed from the glenohumeral joint side. Viewing the subacromial space usually revealed an entirely normal cuff with no sign of subacromial impingement. With the arthro-scope in the glenohumeral joint, the footprint area of the supraspinatus tendon was prepared and one or two anchors, each preloaded with two sutures, were passed through the rotator cuff into the footprint area of the greater tuberosity. The sutures attached to these anchors were passed through the tendon and tied in the subacromial space. The Constant score improved from a preoperative mean of 72 to a postoperative mean of 91. The greatest increase was in power and overhead motion, especially abduction and external rotation. PASTA lesions are difficult to diagnose, even with MRI. The ‘all inside’ method of arthroscopic repair obviates the need to detach intact fibres

We undertook clinical and ultrasonographic examination of the shoulders of 420 asymptomatic volunteers aged between 50 and 79 years. MRI was performed in selected cases. Full-thickness tears of the rotator cuff were detected in 32 subjects (7.6%). The prevalence increased with age as follows: 50 to 59 years, 2.1%; 60 to 69 years, 5.7%; and 70 to 79 years, 15%. The mean size of the tear was less than 3 cm and tear localisation was limited to the supraspinatus tendon in most cases (78%). The strength of flexion was reduced significantly in the group with tears (p = 0.01). Asymptomatic tears of the rotator cuff should be regarded as part of the normal ageing process in the elderly but may be less common than hitherto believed

This study looks at the dynamic tendon-to-bone contact properties of rotator cuff (RC) repairs—comparing single row repairs (SRR) with double row transosseous- equivalent (TOE) repairs. It was postulated that relaxation during, and movement following, the repair would significantly compromise contact properties and therefore, the ability of the tendon healing. Simulated tears were created in the supraspinatus tendon of six cadaveric human shoulders. A SRR was then performed using the OPUS System, creating two horizontal mattress sutures. An I-Scan electronic pressure-sensor (Tekscan, Boston, MA) was placed between the supraspinatus tendon and bone. The arm was then rested for 300secs (relaxation) before being passively moved twice through a range-of-motion (0-90 degrees abduction, 0-45 external and 0-45 internal rotation) and finally returned to neutral. The contact properties were recorded throughout each movement. The procedure was then repeated using two TOE techniques: parallel sutures (TOE-P) and a cross over suture pattern (TOE-C). While peak pressures during the repair were higher in the two TOE repairs, all three methods demonstrated relaxation over 300s such that there was no significant diference in contact pressures at the end of this time. TOE parallel and cross-over repairs demonstrated no significant change in mean TTB contact pressure, force and area during abduction, external rotation and return to neutral, when compared to the 300sec relaxation state. TOE-C demonstrated a higher contact force on internal rotation (+53%). The SRR demonstrated a significant drop in contact force on abduction (−63%), and return to neutral (−43%) and a trend on external rotation (−34%). SRR exhibited no change on internal rotation. There have been very few biomechanical studies with which observe RC repair contact properties dynamically. Relaxation of the repair can be partially reversed. Significant decrease in contact area with SRR during movement occurred, compared to the TOE repairs, which remains unaltered. This is an important consideration when determining postoperative rehabilitation

The cellular mechanisms of tendinopathy remain unclear, particularly with respect to the role of inflammation in early disease. We have previously identified increased levels of inflammatory cytokines in an early human model of tendinopathy and sought to extend these studies to the cellular analysis of tissue. Purpose. To characterise inflammatory cell subtypes in early human tendinopathy we explored the phenotype and quantification of inflammatory cells in torn and control tendon samples. Design. Controlled laboratory study. Methods. Torn supraspinatus tendon and matched intact subscapularis tendon samples were collected from twenty patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from ten patients undergoing arthroscopic stabilisation surgery. Tendon biopsies were evaluated immunohistochemically by quantifying the presence of macrophages (CD68 and CD206), T cells (CD3), mast cells (Mast cell tryptase) and vascular endothelium (CD34). Results. Subscapularis tendon biopsies obtained from patients with torn supraspinatus tendon exhibited significantly greater macrophage, mast cell and T cell expression compared to either torn supraspinatus samples or control subscapularis derived tissue (p< 0.01). Inflammatory cell infiltrate correlated inversely (r=0.5, p< 0.01) with rotator cuff tear size, with larger tears correlating with a marked reduction in all cell lineages. There was a modest but significant correlation between mast cells and CD 34 expression (r= 0.4, p< 0.01) in pre-rupture subscapularis tendon. Conclusion. We provide evidence for an inflammatory cell infiltrate in early mild/moderate human supraspinatus tendinopathy. In particular, we demonstrate significant infiltration of mast cells and macrophages suggesting a role for innate immune pathways in the events that mediate early tendinopathy. Further mechanistic studies to evaluate the net contribution and hence therapeutic utlity of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early tendinopathy

Introduction. Following tear of its tendon, the muscle undergoes retraction, atrophy and fatty infiltration. These changes are inevitable and considered irreversible and limit the potential of successful repair of musculotendinous units. It was the purpose of this study to test the hypothesis that administration of anabolic steroids can prevent these muscular changes following experimental supraspinatus tendon release in the rabbit. Methods. The supraspinatus tendon was experimentally released in 20 New Zealand rabbits. Musculotendinous retraction was monitored over a period of 6 weeks. The seven animals in group I had no additional intervention, six animals in group II had local and seven animals in group III had systemic administration of nandrolone deconate during six weeks of retraction. At the time of sacrifice, in-vivo muscle performance as well as radiologic and histologic muscle changes were investigated. Results. Supraspinatus retraction was significantly higher in group I (1.8 ± 0.2cm) than in group II (1.5 ± 0.3cm, p = 0.044) or III (1.2 ± 0.3cm, p = 0.001). The reduction in radiological cross sectional area, as a measure for atrophy, was significant in groups I (p = 0.013) and II (p = 0.030) and insignificant in group III (p = 0.149). Histologically, there was no fatty infiltration in the treated groups II (p = 1.000) and III (p = 0.812), but in the untreated group I (p = 0.0312). The work of the respective muscle during one standardized contraction with supramaximal stimulation decreased markedly in groups I (p = 0.056) and II (p = 0.0528), and also but less in group III (p = 0.23). Conclusion. This is the first documentation of prevention of important muscle alterations after chronic retraction of the musculotendinous unit caused by rotator cuff tear. Nandrolone deconate administration in the post tendon release phase prevented fatty infiltration of the supraspinatus muscle and reduced functional muscle impairment caused by myo-tendinous retraction

Introduction and Objectives: Damage of the supraspinatus tendon (SST) is frequent in persons over 50 years of age. The aim of our study is to assess the degree of satisfaction and shoulder functionality after suture of the SST during open surgery by means of a 11–13 year follow-up. Materials and Methods: Between 1995 and 1997 in our center, by means of open surgery, 45 SST sutures were performed (< 4 cm) with associated acromioplasty. At a minimum of 11 years follow-up we assessed the degree of patient satisfaction and performed the Constant test and the Jobe test. Results: We studied 36 shoulders belonging to 33 patients (6 were lost to follow-up and 3 died). There were 21 women (63.6%) and 12 men (36.4%) in the series. Mean age was 52.3 years (31–64) and the affected shoulder was on the dominant side in 82% of cases (3 were bilateral). Of the 33 patients (36 shoulders) we obtained 21 very good scores (58.3%), 11 good (30.5%), 3 regular (8.3%) and 1 poor (2.7%). Using Constat’s test we obtained a mean score of 74.7 at the end of the process (pain 12.6, activity 18.1, mobility 36.9 and strength 7). We also used the Jobe supraspinatus test to assess patients and obtained negative results in 22 cases (61.1%), positive results in 8 cases (30.5%) and no results in 3 cases (8.3%). Discussion and Conclusions: We were able to see both clinical improvement (subjective and Constant test) and strength in the supraspinatus tendon (Jobe) in 91.7% of cases at 11–13 years of follow-up

Purpose of this study is to create an experimental model of electrophysologic evaluation of the supraspinatus muscle on rats, after traumatic rupture of its tendon. The population of this study consisted of 10 male Sprague Dawley rats weighting 300–400g. Under general anaesthesia we proceeded with traumatic rupture of the supraspinatus tendon and exposure of the muscle. The scapula was immobilized, and the supraspinatus tendon was attached to a force transducer using a 3–0 silk thread. A dissection was performed in order to identify the suprascapular nerve, which was then stimulated with a silver electrode. Stimulations were produced by a stimulator (Digitimer Stimulator DS9A) and were controlled by a programmer (Digitimer D4030). Fiber length was adjusted until a single stimulus pulse elicited maximum force during a twitch under isometric conditions. Rectangular pulses of 0.5 ms duration were applied to elicit twitch contractions. During the recordings, muscles were rinsed with Krebs solution of approximately 37 8C (pH 7.2–7.4) and aerated with a mixture of 95% O2 and 5% CO2. The output from the transducer was amplified and recorded on a digital interface (CED). The following parameters were measured at room temperature (20–21 8C): single twitch tension; time to peak; half relaxation time; tetanic tensions at 10, 20, 40, 80 and 100 Hz; and fatigue index, which was evaluated using a protocol of low frequency (40 Hz) tetanic contraction, during 250 ms in a cycle of 1 s, for a total time of 180 s. The fatigue index value was then calculated by the formula [fatigue index=(initial tetanic tension − end tetanic tension) ∗ 100/(initial tetanic tension)]. In the end, the transducer was calibrated with standard weights and tensions were converted to grams. The mean single twitch was 8.2, the time to peak 0.034 msec and the half relaxation time 0.028 msec. The strength of titanic muscle contractures was 5.7 msec at 10Hz and 17.7 at 100Hz. Finally, the fatigue index was calculated at 48.4. We believe that electrophysiologic evaluation of the supraspinatus muscle in rats will help us understanding the pathology of muscle atrophy after rotator cuff tears and possibly the functional restoration after cuff repair

Aim: We hypothesize that anabolic steroid administration enhances matrix remodelling and improves the biomechanical properties of bio-artificially engineered human supraspinatus tendons (BATs). Method: BATs were treated either with nandrolone decanoate (NLS group, n=18), stretching (LNS group, n=18), or both (LS group, n=18). A control group received no treatment (NLNS group, n=18). BATs’ contractility was assessed by daily scanning and two dimensional analysis. Cytoskeletal organization was evaluated microscopically with DAPI and rhodamine phalloidin staining. Matrix metalloproteinase-3 (MMP-3) levels – an indicator of matrix remodelling – were discerned by ELISA assay, and biomechanical properties by load-to-failure testing. Results: The LS group showed greatest contractility and the best-organized actin cytoskeleton when compared to the other groups. On the second and third day of treatment, MMP-3 levels in the LS group were significantly greater than those of NLNS group and greater than NLS and LNS groups. The biomechanical properties (load to failure, ultimate stress, ultimate strain, elastic modulus, and energy to failure) in the LS group were significantly improved when compared to NLNS and NLS (p< .05) groups and 26–48% greater than those in LNS group. Conclusions: Nandrolone decanoate and load act synergistically to increase matrix remodelling and biomechanical properties of bioengineered human supraspinatus tendons. Carefully prescribed and monitored, anabolic steroids may have an important adjunct role in postoperative healing and rehabilitation of repaired rotator cuff tendons. More research is necessary to fully evaluate the safety and efficacy of anabolic steroids in this application

This in-vitro study was conducted to determine the effect of rotator cuff tears on joint kinematics. A shoulder simulator produced unconstrained active abduction of the humerus. Three sequential 1cm lesions were created, the first two in the supraspinatus tendon and the third in the subscapularis tendon. The plane of abduction moved posteriorly and became more abnormal throughout abduction as the size of the tear increased. It is concluded that in order to generate the same motions achieved by the intact joint other muscle groups must be employed, inevitably resulting in altered joint loading. This in-vitro study was conducted to determine the effect of simulated progressive tears of the rotator cuff on active glenohumeral joint kinematics. Five cadaveric shoulders were tested using a shoulder simulator designed to produce unconstrained active motion of the humerus. Forces were applied to simulate loading of the supraspinatus, subscapularis, infraspinatus/teres minor, anterior, middle, and posterior deltoid muscles based upon variable ratios of electromyographic data and average physiological cross-sectional area of the muscles. Three sequential 1cm lesions were created, the first two in the supraspinatus tendon and the third in the subscapularis tendon. Simulated active glenohumeral abduction was performed following the creation of each lesion. Five successive tests were performed to quantify repeatability. The plane of abduction moved posteriorly and became more abnormal throughout abduction as the size of the lesion increased (p=0.01) (Figure 1). In order to generate the same motions achieved with an intact rotator cuff other muscle groups must be employed, inevitably resulting in altered joint loading. A better understanding of the effects that rotator cuff tears have on the kinematics of the glenohumeral joint may result in the development of innovative rehabilitation strategies to compensate for this change in muscle balance and improve the clinical outcomes. Please contact author for diagram and/or graph

Summary Statement. Tendon-bone interface becomes matured with the perforating fiber and the cells striding over the bone area. We suggest that both “perforating fiber” and “cell stride” could play a crucial role in regeneration after rotator cuff repair. Introduction. To obtain a successful outcome after rotator cuff repair, repaired tendon requires to be anchored biologically to the bone. However, it is well known that the histological structure of the repaired tendon-bone insertion is totally different from the normal insertion. This morphological alteration may contribute to biological instability after surgical repair. To address these issues, it is fundamental to clarify the difference of the structure between the normal and the repaired insertion in detail. Surprisingly, few studies on the tendon-bone insertion using electron microscopy has been performed so far, since the insertion area is solid (bone/cartilage) and extremely limited for the analysis. Recently, a new scanning electron microscopical method (FIB/SEM tomography) has been developed, making it possible to analyze the wider area with the higher resolution and reconstruct 3D ultrastructures. The purpose of this study was to analyze the ultrastructure of the repaired supraspinatus tendon-bone insertion in rat using FIB/SEM tomography. Materials and Methods. Adult Sprague-Dawley rats underwent complete cuff tear and subsequent repair of the supraspinatus tendon. The repaired supraspinatus tendon-bone interface was evaluated at 2 and 4 weeks after surgery. At each time point, 6 shoulders were used for biomechanical testing (ultimate load-to-failure and linear stiffness), 3 shoulders for conventional histological analysis and 3 shoulders for the ultrastructural analysis. The supraspinatus tendon insertion of the age-matched adult SD rats was used as normal control. For statistical analysis, the Wilcoxon's rank sum test was used to compare load-to-failure and linear stiffness. Differences of P<0.05 were considered significant. Results. <Biomechanical testing> All shoulders failed at the tendon-bone interface. The ultimate load-to-failure and the linear stiffness were significantly greater at 8 weeks than at 4 weeks (p<0.05). Normal tendon-bone insertion: The normal supraspinatus insertion consists of four-layered structure: tendon, fibrocartilage, mineralised fibrocartilage and bone. Repaired tendon-bone interface. At week 2, the fibro-vascular tissue was intervened between the tendon and bone at the repaired site. At week 4, the fibro-vascular tissue became organised, and perforating fibers were partially observed. <Ultrastructure using FIB/SEM tomography> Normal tendon-bone insertion: The ultrastructure of the normal supraspinatus insertion was very smooth. The cells were located between collagen bundles and arranged with their cell processes parallel to the bundles. Repaired tendon-bone interface: At week 2, the cells in the fibro-vascular tissue were arranged irregularly. At week 4, a part of the cells became arranged regularly and participated in linkage between the fibro-vascular tissue and bone, striding their processes across the bone side. Apparent boundary separating the fibro-vascular tissue from bone was observed throughout the periods. Conclusion. At 4 weeks after surgery, the repaired supraspinatus insertion remains to be immature and biologically weak. At 8 weeks after the surgery, it becomes matured with the perforating fiber and the cells striding over the bone area. We therefore suggest that both “perforating fiber” and “cell stride” could play a crucial role in regeneration of the tendon-bone interface after rotator cuff repair

Aim To determine if tissue metabolism varies in supraspinatus tendons with distance from the edge of the rotator cuff tendon tear and also with differing size of tear. Background Tissue metabolism can be assessed by measuring oxygen and nitrous oxide concentrations within the tissue. Viable tendon tissue consumes oxygen and contains nitrous oxide (used in the general anaesthetic) from the blood stream. Non-viable tendon tissue will not consume oxygen but will contain nitrous oxide. Methods Oxygen and Nitrous Oxide concentrations were measured amperometrically using silver needle microelectrodes. The needle was inserted into the supraspinatus tendon of patients with massive, large, medium and small full thickness rotator cuff tears and patients with partial thickness and no tears. Patients undergoing open stabilisation were used as controls. Measurements were made at a number of quantifiable points from the tendon edge to allow the creation of a topographical map of tissue metabolism. Oxygen consumption was calculated using measured oxygen and nitrous oxide levels at each point. Results In patients with rotator cuff tears oxygen consumption was significantly lower near to the edge of the tear. Patients with impingement syndrome but no evidence of a rotator cuff tear also showed a decreased level of oxygen consumption in the anterior part of supraspinatus, but this was significantly higher than the levels seen in the torn tendon. The control group showed no significant alteration in oxygen levels. Conclusion Patients with rotator cuff tendon tear demonstrate significantly reduced levels of tissue metabolism. This reduction in tissue viability is significantly greater at the edge of the tear and in larger tears. Patients with intact tendons and impingement syndrome also demonstrate minor reduction in tissue tendon viability compared with controls

Aim: We hypothesized that anabolic steroid, combined with substrate strain upregulates expression of gap junction protein Connexin 43 (Cnx43) and increases cell-to-cell communication in human supraspinatus tendon cells. Methods: Human supraspinatus cells were isolated and cultured in nutrient media arranged into 4 groups: 1) non-load, non-steroid (NLNS, n=12); 2) non-load, steroid (NLS, n=12); 3) load, non-steroid (LNS, n=12); and 4) load, steroid (LS, n=12). Steroid and load groups were cultured in 100Nm nandrolone decanoate and loaded at 1% elongation daily for 5 days, respectively. On day five of treatment, cells examined for immunocytochemistry. Cells were also subjected to mechanical stimulation by micro-pipette indentation and the intracellular calcium concentration ([Ca2+]ic) was quantitated using fluorescence microscopy. Numerous parameters were calculated: a) mean average response to stimulation, b) mean peak [Ca2+]ic, c) time of Ca2+ wave propagation, d) spontaneously responding cells prior to stimulation, and e) cell oscillation after stimulation (an indicator of cell toxicity). Results: The LS group demonstrated the greatest density of Cnx43 in comparison to the other groups. Also, the LS group cells showed a significantly greater mean peak [Ca2+]ic and a significantly decreased propagation time, compared to the values of the other groups (p< 0.05). Conclusions: Anabolic steroid, when combined with passive stretch, upregulates gap junction protein Cnx 43 and significantly increases calcium signalling in human supraspinatus tendon cells. When carefully prescribed and monitored, anabolic steroids may increase intercellular calcium signalling and may enhance the healing process of deficient rotator cuff tendons. More research will be necessary to fully evaluate the safety and efficacy of anabolic steroids for this application

This study aimed to quantify the relationship between passive tension of rotator cuff repair and arm position intraoperatively and to examine the effect of the passive tension on gap formation in cadaveric rotator cuff repairs. Five patients undergoing open surgical reconstruction of the rotator cuff were recruited. The operations were performed by a single surgeon using a standardised technique, which was acromioplasty, minimal debridement, mobilisation of tissue, bone troughs and transosseous suture tunnels. A Differential Variable Reluctance Transducer (DVRT) was placed at the apex of the debrided tendon. An in situ calibration was performed to relate the output from the DVRT to actual tension in the tendon. The tension generated was recorded as the supraspinatus tendon was advanced into a bone trough and secured. The relationship between arm position and repair tension was measured, by simultaneously collecting data from the DVRT and a calibrated goniometer. Particular attention was paid to the three standard positions of post-operative immobilisation; full adduction with internal rotation, neutral rotation with a 30° abduction wedge and ninety degrees of abduction. Five cadaveric shoulders were used for the creation of standardised rotator cuff tears which were then repaired using the technique described above. The difference in tension measured between full adduction and 30° abduction was statically applied for twenty four hours and the gap formation measured. Repair tension increased with advancement of the supraspinatus tendon into the bone trough. Abduction reduced the repair load, this was observed mainly in the first 30° of abduction. The mean reduction in load by 30° of abduction was 34 N. Twenty four hours of 34N static loading caused gap formation in each cadaveric rotator cuff repairs, the mean was 9.2 mm. Rotator cuff repairs tension can be reduced by postoperative immobilisation in 30° abduction. The change in tension with full adduction was caused gap formation in cadaveric rotator cuff repairs

Reliable soft tissue attachment to prosthetic implants remains a great clinical challenge in adult reconstruction and oncology. Past efforts using tendon alone have been universally disappointing. With the introduction of trabecular metals, new possibilities present them selves in dealing with this problem. Using an established canine supraspinatus tendon model, reliable and physiologic soft tissue attachment to a trabecular metal prosthesis was achieved, with near normal strength and function. This suggests that this new genre of material can possibly provide better options in dealing with this difficult problem. Direct attachment of tendon to an endoprothesis has applications throughout the field of orthopaedics. The purpose of this study was to devise a soft-tissue attachment device using tantalum foam metal which would allow for early soft tissue reconstruction strength and long term biologic in-growth fixation. A foam metal tendon attachment prosthesis was designed. Using a validated tendon attachment model, twenty-three skeletally-mature canine supraspinatus tendons were sharply detached and then reattached to the greater tuberosity. Ultimate strength, stiffness and gross morphological changes were recorded immediately after surgery and at three and six weeks. Tendon-implant strength as percent of normal rose from thirty-nine percent at surgery, to sixty-seven percent at three weeks, and ninety-nine percent at six weeks (standard deviations thirteen, nineteen, and eighteen percent). Stiffness of construct also approached normal tendon: forty-seven percent at surgery, sixty-two percent at three weeks, and ninety-four percent at six weeks (standard deviations seventy-seven, nineteen, and eighteen percent). Supraspinatus muscle volume decreased from ninety seven (percent of normal) at surgery, to seventy-nine percent at three weeks. By six weeks, the muscle had recovered to ninety percent of normal volume. Gross and histologic analysis revealed complete tendon in-growth and attachment to the prosthesis with the formation of Sharpey’s fibers. This study suggests that tendon attachment to a metallic endoprothesis is possible. Near normal physiologic strength and stiffness was achieved six weeks post surgery. Future study should ascertain the micro-anatomy of this attachment and delineate the mechanical conditions necessary for soft tissue in-growth. Funding: Zimmer, Inc., Warsaw, IN. Please contact author for pictures, graphs and diagrams

Purpose: We present the results of subacromial decompression and repair of the rotator cuff through a minimal deltoid-on approach. Material and Method: Eighty-seven patients with longstanding shoulder pain were evaluated in two years (1999–2000) in our department. In sixty -eight of them symptoms were due to impigment syndrome. Eight patients with follow up time less than six months were excluded from this study, twenty were treated conservatively and the remaining forty (22 female, 18 male, mean age 50.3) underwent surgery. Three x-ray views were obtained in all patients, i.e. standard AP, true AP, and subacromial space projection. MRI was also obtained in all patients. MRI revealed calcific tendinitis in fifteen patients, osteophytes of the acromioclavicular joint in thirteen, a hooked (type III) acromion in ten and partial tear of the supraspinatus tendon in nineteen. In five of them there was also a partial tear of the infraspinatus. Finally, seven patients were suffering of a full thickness tear of the supraspinatus tendon. All patients were operated through a minimal deltoid-on approach. Acromioplasty and coracoacromial ligament dissection was performed in all. In patients with osteoarthritis of the acromioclavicular joint, osteophytes were carefully removed. Calcific deposits were also removed in all patients. In eighteen patients tears of the rotator cuff were detected and repaired using bone anchors. Results: All patients were examined six months postoperatively. Results were evaluated with CONSTANT SCORE and with a questionnaire for patient’s satisfaction. Thirty-seven patients were very satisfied with the result and three were satisfied. As for Constant score, pain improved at an average of 7.8 points, daily activities by 5.4, and range of movement by 4.2 points. Results were evaluated by the examiner as excellent in thirty-six patients (90%) and very good in four patients. Conclusion: Deltoid-on approach, in patients with impingement syndrome of the shoulder provides adequate exposure for the surgical repair with minimal trauma and a very low rate of complications

The retear of the rotator cuff (RC) repair is a significant problem. Usually it is the effect of poor quality of the tendon. The aim was to evaluate histologically two types of RC reconstruction with scaffold. We have chosen commercially available scaffold polycaprolactone based poly(urethane urea). Rat model of supraspinatus tendon injury was chosen. There were four study groups: RC tear (no repair) (n=10), RC repair (n=10), RC repair augmented with scaffold (n=10) and RC reconstruction with scaffold interposition between tendon and bone (n=10). The repairs were investigated histologically at 6 and 16 weeks. The results in two groups in which scaffold was used had significantly better scores at 6 weeks comparing to non-scaffold groups (16,4±3, 17,3± 2,8 vs. 12,5±4,4, 13,8±1,4 respectively) and 16 weeks (23±1,9, 22,8±1,6 vs. 13,8±3,3, 14,9± 3,8 respectively). Results in two scaffold groups improved between 6 and 16 weeks. Signs of foreign body reaction against scaffold were not observed. Application of scaffold to strengthen the repair site and bridging of the tendon defect improved healing of the RC repair in animal model at 6 and 16 weeks. The quality of reconstructed tendon improved over time. No such effect was observed in groups without repairs and isolated repairs were performed

1. In a series of one hundred personal cases of "painful shoulder" rupture of the musculotendinous cuff was proved by operation in eighteen cases and was presumed in eight further cases, namely, in about one quarter of the series. 2. Of the eighteen cases treated by operation through the transacromial approach, perfect results were obtained only in four. The other results were unsatisfactory. In five, movement was good but there was pain or weakness of the limb. In nine the condition was unaltered or made worse. 3. Conservative treatment of traumatic lesions of the supraspinatus tendon is therefore advocated. The advisability of rest of the shoulder joint in an abduction splint for five or six weeks is stressed. Operative exposure, through a transacromial approach, is recommended only when conservative measures have failed. 4. When there is rupture of the cuff there is evidence that simple longitudinal suture of the gap after freshening of the margins is likely to give better results than attempts to suture the medial end of the rupture to the greater tuberosity. Most ruptures have a longitudinal extension of the initial transverse tear, and direct suture of the medial edge of the gap to the greater tuberosity may lead to shortening of the tendon and interference with its function. 5. Ruptures of the supraspinatus tendon may cause no symptoms, lead to complete loss of function, or cause a painful arc of movement during mid-elevation. The clinical state depends upon whether or not the condition of the ruptured tendon is causing pain, and whether the other short rotator muscles of the shoulder can compensate in tensor and fixator actions for the loss of action of the supraspinatus. 6. Capsulitis is a convenient term by which to describe inflammatory lesions of the capsule and bursae around the shoulder joint. The initial stage of irritative capsulitis may develop to the later stage of adhesive capsulitis. Differentiation is important because treatment in the first stage is by rest, and in the second by manipulation and exercise. 7. The subdeltoid bursa is the "peritoneum" of the spinatus tendons; like the peritoneum it shares the pathology of the organs it protects and is itself seldom the site of primary pathological processes. 8. The management of the "frozen shoulder," whether loss of movement is protective or adhesive, calls for time and patience but the ultimate outlook is good

Introduction: Restoration of original humeral head geometry in shoulder arthroplasty is a necessary requirement and may have a bearing on the longevity of the implant. Modern, adaptable, prosthetic components are believed to allow restoration of the individual’s proximal humeral anatomy, provided a precise osteotomy of the humeral head at the level of the anatomical neck is performed. The osteotomy and reconstruction of the humeral head is based on the assumption that the resected articular segment corresponds to a segment of a sphere oriented, identically, in inclination and retroversion to the original humeral head. Resection, along the mid-anterior portion of the cartilage/calcar border, is understood to create a surface that enables a prosthetic component to be mounted, retroverted and inclinated to the same degree as the original head geometry. The objective of this study was to determine the degree of variation in humeral head retroversion relative to the superior and inferior borders of the proximal humeral articular surface. Methods: Twenty-eight fresh frozen human cadaveric full arms were dissected free of soft tissue to expose the proximal humerus. The distal end of the humeral shaft was potted in PMMA and fixed rigidly in a custom–built jig. The following points and lines were identified and marked on each specimen:. the circumference of the anatomical neck;. (H) as the most superior point of the articular surface at the insertion of the supraspinatus tendon, (L) as the corresponding lowest point of the articular surface at the cartilage/calcar interface;. The medial (MC) and lateral (LC) humeral condyles were exposed and delineated with k-wires. A Microscribe 3D-X digitizer was used to digitize the points and lines. The data for each humerus were imported into Rhinoceros NURBS modelling software and graphically represented. The constructed graphical model was used to divide the articular portion of the humeral head into six equal sections in the axial plane. The retroversion angle, relative to the epicondyles, was calculated for each section. Results: A linear decrease in retroversion angle was noted from the most superior to most inferior point on the proximal humeral articular surface. The retroversion angle was greatest at the level of the insertion of the supraspinatus tendon (34.2deg +/−13.7deg) and least at the inferior cartilage/calcar interface (24.3deg +/−10.2deg). Discussion: Accurate recovery of humeral head geometry is a requirement in order to achieve good function. The variability in retroversion, as it relates to its point of measurement, may effect the accuracy of pre-operative assessment of a patient’s humeral head geometry as well as the osteotomy during shoulder arthroplasty, and, thus, may impact on joint range of motion and stability post-operatively. Further investigation is warranted

PEMF is currently approved by the FDA for adjunctive treatment of lumbar/cervical spine fusion and for treatment of long-bone non-unions. Soft tissues are a potential new therapeutic application for PEMF due to pre-clinical studies showing a reduction of inflammatory markers following PEMF exposure. The aim was therefore to investigate the structural/functional effects of PEMFs on tendon-to-bone and tendon-to-tendon healing in a rotator-cuff (RC) and Achilles tendon (AT) repair model, respectively. RC study: Adult male rats (n=280), underwent bi-lateral supraspinatus tendon transections with immediate repair followed by cage activity until sacrifice (4, 8, and 16 weeks). Non-controls received PEMF for 1, 3, or 6 hours daily. AT study: Male rats underwent acute, complete transection and repair of the Achilles tendon (FULL, n=144) or full thickness, partial width injury (PART, n=160) followed by immobilization for 1 week. Sacrifice was at 1, 3, and 6 weeks. Outcome measures included passive joint mechanics, gait analysis, biomechanical assessments, histological analysis of the repair site and mCT (humerus) assessment (FULL only). RC study: Significant increases in modulus, stiffness, bone mineral content and improved collagen organization was observed for the PEMF groups. No differences in joint mechanics and ambulation were observed. AT study: A decrease in stiffness and limb-loading rate was observed for the PEMF groups for the FULL groups, whereas an increase in stiffness with no change in range-of-motion was seen for the PART groups. The combined studies show that PEMF can be effective for soft tissue repair but is dependent on the location of application

Surgical repair of rotator cuff tears have high failure rates (20–70%), often due to a lack of biological healing. Augmenting repairs with extracellular matrix-based scaffolds is a common option for surgeons, although to date, no commercially available product has proven to be effective. In this study, a novel collagen scaffold was assessed for its efficacy in augmenting rotator cuff repair. The collagen scaffold was assessed in vitro for cytocompatability and retention of tenocyte phenotype using alamarBLUE assays, confocal imaging and real-time PCR. Immunogenicity was assessed in vitro by the activation of pre-macrophage cells. In vivo, using a modified rat rotator cuff defect model, supraspinatus tendon repairs were carried out in 46 animals. Overlay augmentation with the collagen scaffold was compared to unaugmented repairs. At 6- and 12-weeks post-op the repairs were tested biomechanically to evaluate repair strength, and histologically for quality of healing. The collagen scaffold supported human tenocyte growth in vitro, with cells appearing morphologically tenocytic and expressing higher tendon gene markers compared to plastic controls. No immunogenic responses were provoked compared to suture material control. In vivo, augmentation with the scaffold improved the histological scores at 12 weeks (8.37/15 vs. 6.43/15, p=0.0317). However, no significant difference was detected on mechanical testing. While the collagen scaffold improved the quality of healing of the tendon, a meaningful increase in biomechanical strength was not achieved. This is likely due to its inability to affect the bone-tendon junction. Future materials/orthobiologics must target both the repaired tendon and the regenerating bone-tendon junction

Our aim in this prospective study was to evaluate the outcome of total shoulder replacement in the treatment of young and middle-aged active patients with primary glenohumeral osteoarthritis. We reviewed 21 patients (21 shoulders) with a mean age of 55 years (37 to 60). The mean follow-up was seven years (5 to 9). The same anatomical, third-generation, cemented implant had been used in all patients. All the patients were evaluated radiologically and clinically using the Constant and Murley score. No patients required revision. In one a tear of the supraspinatus tendon occurred. Overall, 20 patients (95%) were either very satisfied (n = 18) or satisfied (n = 2) with the outcome. Significant differences (p < 0.0001) were found for all categories of the Constant and Murley score pre- and post-operatively. The mean Constant and Murley score increased from 24.1 points (10 to 45) to 64.5 points (39 to 93), and the relative score from 30.4% (11% to 50%) to 83% (54% to 116%). No clinical or radiological signs of loosening of the implant were seen. For young and middle-aged patients with osteoarthritis, third-generation total shoulder replacement is a viable method of treatment with a low rate of complications and excellent results in the mid-term

We have studied cellular and vascular changes in different stages of full thickness tears of the rotator cuff. We examined biopsies from the supraspinatus tendon in 40 patients with chronic rotator cuff tears who were undergoing surgery and compared them with biopsies from four uninjured subscapularis tendons. Morphological and immunocytochemical methods using monoclonal antibodies directed against leucocytes, macrophages, mast cells, proliferative and vascular markers were used. Histological changes indicative of repair and inflammation were most evident in small sized rotator cuff tears with increased fibroblast cellularity and intimal hyperplasia, together with increased expression of leucocyte and vascular markers. These reparative and inflammatory changes diminished as the size of the rotator cuff tear increased. Marked oedema and degeneration was seen in large and massive tears, which more often showed chondroid metaplasia and amyloid deposition. There was no association between the age of the patient and the duration of symptoms. In contrast, large and massive tears showed no increase in the number of inflammatory cells and blood vessels. Small sized rotator cuff tears retained the greatest potential to heal, showing increased fibroblast cellularity, blood vessel proliferation and the presence of a significant inflammatory component. Tissue from large and massive tears is of such a degenerative nature that it may be a significant cause of re-rupture after surgical repair and could make healing improbable in this group

Bone marrow concentrates are being used to augment soft tissue healing. However, only 0.01% of these cells meet the criteria of a mesenchymal stem cell (MSC), which likely accounts for the variability in reported results. Previous studies using an established rat rotator cuff repair model have demonstrated that bone marrow-derived MSCs had no effect on healing. In this study we evaluated the effect of purified human MSCs on rotator cuff healing in an athymic rat model. Hypothesis: Purified human MSCs added to the repair site will improve biomechanical strength and fibrocartilage formation of the healing tendon. Fifty-two athymic rats underwent unilateral detachment and repair of the supraspinatus tendon with either fibrin glue (control) or fibrin glue with 106 hMSCs (experimental) applied at the repair site. Flow cytometry verified the stem cell phenotype of the cells as CD73+, CD90+, CD105+, CD14-, CD34- and CD45-. Rats were sacrificed at 2 and 4 weeks, with 10 used for biomechanical testing and 3 for histologic analysis from each group. Biomechanical testing revealed a significant increase in failure load (11.5±2.4N vs. 8.5±2.4N, p=0.002) and stiffness (7.1±1.2 N/mm vs. 5.7±2.1 N/mm, p0.17). These data demonstrate the potential for stem cells to augment tendon healing. This is the first study to use purified stem cells, rather than simple bone marrow concentrate. In the future, cell sorting techniques and culture expansion could be used to select and expand the small population of true stem cells in bone marrow. Furthermore, healing could potentially be improved with repeat cell injection at an additional post-operative time point

Rotator cuff pathology is the main cause of shoulder pain and dysfunction in older adults. When a rotator cuff tear involves the subscapularis tendon, the symptoms are usually more severe and the prognosis after surgery must be guarded. Isolated subscapularis tears represent 18% of all rotator cuff tears and arthroscopic repair is a good alternative primary treatment. However, when the tendon is deemed irreparable, tendon transfers are the only option for younger or high-functioning patients. The aim of this review is to describe the indications, biomechanical principles, and outcomes which have been reported for tendon transfers, which are available for the treatment of irreparable subscapularis tears.

The best tendon to be transferred remains controversial. Pectoralis major transfer was described more than 30 years ago to treat patients with failed surgery for instability of the shoulder. It has subsequently been used extensively to manage irreparable subscapularis tendon tears in many clinical settings. Although pectoralis major reproduces the position and orientation of the subscapularis in the coronal plane, its position in the axial plane – anterior to the rib cage – is clearly different and does not allow it to function as an ideal transfer. Consistent relief of pain and moderate recovery of strength and function have been reported following the use of this transfer. In an attempt to improve on these results, latissimus dorsi tendon transfer was proposed as an alternative and the technique has evolved from an open to an arthroscopic procedure. Satisfactory relief of pain and improvements in functional shoulder scores have recently been reported following its use. Both pectoralis minor and upper trapezius transfers have also been used in these patients, but the outcomes that have been reported do not support their widespread use.

Cite this article: Bone Joint J 2024;106-B(9):970–977.

Alarmins- also referred to as damage associated molecular patterns (DAMPS)- are endogenous molecules mobilized in response to tissue damage known to activate the innate immune system and regulate tissue repair and remodelling. The molecular mechanisms that regulate inflammatory and remodelling pathways in tendinopathy are largely unknown therefore identifying early immune effectors is essential to understanding the pathology. S100A8 and S100A9 are low molecular weight calcium binding proteins primarily released by activated phagocytes in an inflammatory setting and also secreted as a heterodimeric complex that exhibits cytokine like functions. Based on our previous investigations we sought evidence of S100A8/A9 expression in human tendinopathy and thereafter, to explore mechanisms whereby S100 proteins may regulate inflammatory mediators and matrix regulation in human tenocytes. Torn supraspinatus tendon (established pathology) and matched intact subscapularis tendon (representing ‘early pathology’) biopsies were collected from patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from patients undergoing arthroscopic stabilisation surgery. S100A8/A9 expression was analysed at transcript and protein level using quantitative RT-PCR and immunohistochemistry, respectively. Primary human tenocytes were cultured from hamstring tendon tissue obtained during hamstring tendon ACL reconstruction. The in vitro effect of recombinant human S100 A8/A9 on primary human tenocytes was measured using quantitative RT-PCR and ELISA. Immunohistochemistry of tendinopathic tissues demonstrated the presence of S100 A8/A9 in diseased tissues compared to control tissue. In addition, early pathological diseased tissue indicated greater S100A9 expression compared with established diseased pathology. These findings were reflected by data obtained at transcript level from diseased tissues. Recombinant human S100A8, A9 and A8/A9 complex led to significant increase in expression of inflammatory mediators, including IL-6 in vitro. Further analysis via quantitative RT-PCR demonstrated recombinant S100A8, A9 and A8/A9 complex treatment on tenocytes, in vitro, had no direct effect on the expression of genes involved in matrix remodelling. The presence of S100A8 and S100A9 in early tendinopathic lesions suggests expression is upregulated in response to cellular damage. S100A8 and S100A9 are endogenous ligands of Toll-like receptors (TLRs) and receptor for advanced glycation end products (RAGE). These receptors have known regulatory effects on immune mediated cytokine production. We propose S100A8 and S100A9 as active alarmins in the early stages of tendinopathy and thus targeting of its downstream signalling may offer novel therapeutic approaches in the management of human tendon disorders

Aims

Favourable short-term outcomes have been reported following latissimus dorsi tendon transfer for patients with an irreparable subscapularis (SSC) tendon tear. The aim of this study was to investigate the long-term outcomes of this transfer in these patients.

Aims

It has been established that mechanical stimulation benefits tendon-bone (T-B) healing, and macrophage phenotype can be regulated by mechanical cues; moreover, the interaction between macrophages and mesenchymal stem cells (MSCs) plays a fundamental role in tissue repair. This study aimed to investigate the role of macrophage-mediated MSC chondrogenesis in load-induced T-B healing in depth.

Introduction. Platelet Rich Plasma (PRP) is widely used in clinical praxis. Especially the effects in musculoskeletal repair studies are diverse and an augmentation of healing processes stays questionable. However, diverse cell culture studies reported promising results, which seem not be transferable into the clinical situation. We therefore performed a cell culture study which better reflects the clinical situation: the autologous stimulation of human tendon cells with PRP. Materials and Methods. Human tenocyte-like cells (hTLCs) from 24 donors (12 male/female) with supraspinatus tendon tears were isolated and characterized. The donors were grouped into 4 groups according to their age (</> 65 years) and sex. During follow up, approximately 2.5 years after initial surgery, the patients donated blood for PRP preparation (Ethic vote and written informed consent). Growth factors and platelets were quantified and the effect of autologous stimulation of the hTLCs was measured by analysis of cell proliferation, Collagen I synthesis and expression of Collagen I, III and Osteocalcin. Results. The platelet concentration for the 4 groups was between 3.6–4.5 × 10. 5. platelets/µl (reference level: 1.5–3×10. 5. platelets/µl blood). PRP contained high amounts of IGF-1, lower amounts of TGF-β1 and PDGF-AB. PDGF-AB concentration significantly correlated with platelet concentration and the TGF-β1 concentration. The amounts of BMP-7 and −12 were underneath the detection limits of the assays. Cell proliferation was positively affected by PRP exposure when compared to controls (2% FCS and 10% FCS) (p<0.05). However, the expression and synthesis of Collagen I was significantly reduced compared to controls. Collagen III expression was partly increased, while Osteocalcin expression was not affected. Discussion. PRP is a source of growth factors such as IGF-1, TGF-β and PDGF-AB. It has a high potential to stimulate cell proliferation, which might have a positive effect in clinical applications. However, the decreased expression and synthesis of Collagen I, the most important Collagen in the tendon, might explain the, to date, less satisfactory clinical results. PRPs might have their potential in chronic situation with pain reducing function rather than in acute healing situations. Further studies are necessary to better understand these mechanisms

We discuss aspects of glenohumeral instability and rotator cuff tears in a clinically orientated approach, presenting a new way of quantifying structural bone loss from the anterior glenoid and defining the Glenoid Index as an indicator of the appropriate surgical approach to address anterior instability. Repair of the rotator cuff depends on viable and functional muscular tissue. We discuss the potential for repair of the supraspinatus tendon in relation to the tangent sign, fat infiltration and retraction. Comparing MRI and arthroscopic findings, we highlight pitfalls in the diagnosis and repair of the subscapularis tendon

Anatomy of the rotator cuff tendons, their relationship to the greater tuberosity, and the tensile and compressive properties of the cuff tendons have been extensively studied recently. From these anatomical and biomechanical studies, it has been clarified that stress concentration at the anterior portion of the supraspinatus tendon, shearing force, and mechanical friction as well as the degenerative weakness of the cuff tendons can all play a role in the occurrence of a tear. Strength of initial repair is limited, and thus the arm after repair should be positioned such that undue tension at the repair site is eliminated

We report an unusual case of knee disease where calcific tendonitis occurring in both quadriceps and patellar tendon simultaneously in the same knee. A 47 year old female presented to orthopaedics outpatient clinic with acute onset of swelling and knee pain with no history of trauma. She was found to have a moderate effusion of the knee joint with mild tenderness over the mid quadriceps tendon. Active flexion of the knee joint was painful with a range of motion between 0-90 degrees. She is otherwise healthy with no past medical history. Plain radiographs and Magnetic Resonance Imaging (MRI) Scan revealed calcification of both tendons. Calcific tendonitis is classically found in the supraspinatus tendon of the shoulder. In addition, it has been described in other areas of the body such as the wrist, thigh, hip, knee and ankle. This condition usually occurs in the quadriceps or patellar tendons separately and rarely affecting both tendons in the same knee simultaneously. The patients condition improved significantly with physiotherapy, anti-inflammatory medications and ultrasound therapy. Calcific tendinitis of both quadriceps and patellar tendon is a very rare cause of knee pain. Most of the time it is treated conservatively with non-steroidal anti-inflammatory drugs and ultrasound therapy and some times steroid injection. However; patient may require surgical intervention especially in refractory cases to resolve the condition

The assessment of the arthroscopic findings in patients suffering from impingement syndrome and partial tear of the supraspinatus tendon, staged as type 1& 2 under Ellman, Gartsman, Snyder, that were treated by acromioplasty, debridment and repair of the supraspinatus tear. Thirty four patients,(20 male, 14 female), with a median age of 52 years, (48–64 years old), underwent shoulder joint arthroscopy. All were evaluated by two physicians and subjected to plain films (AP& Y views) as well as to MRI. Clinically, the differencies in the evaluation of patients with type 1& 2a lesion were insignificant. Type 2b had a better outcome, but in comparison to type 1, that were subjected only to acromioplasty, variations involving range of motion, pain and scoring (Constant & Oxford scores), were observed, from the first stages of rehabilitation, with no further improvement. The comparative method in relation to the clinical trials was in favor of those patients treated with repair of the tear. After a 29 m follow up, we suggest only acromioplasty, in stages 1& 2a, although the daily activities of each patient can change the approach. In type 2b lesions, irrespective of age, we suggest the repair of the tear

Using 26 cadaver shoulders, we produced a standard defect in the supraspinatus tendon and performed one of three types of repair. Their strength was found by testing in tension the force required to produce a gap of 3 mm, then 6 mm, and finally total disruption of the repair. The use of a polyethylene patch to spread the forces over the lateral bone surface and of extra sutures to grasp the tendon end raised by 2.6 times the load at which a 3 mm gap in the repair occurred and by 1.7 times the load to failure

1. The "frozen" shoulder syndrome is due to an inflammatory lesion in the musculotendinous cuff invoked by a local area of degeneration. 2. The available evidence suggests that the primary site of the degenerative lesion is in the supraspinatus tendon. 3. Other causes of shoulder pain which must be differentiated from "frozen" shoulder are peritendinitis of the long head of biceps, degeneration or tears of the supraspinatus, and calcified deposits in the supraspinatus. 4. An explanation of the pathogenesis of lesions of the musculo-tendinous cuff is submitted in which the different types of clinico-pathological syndrome are correlated. This hypothesis is in accord with the experimental, clinical and operative findings

Previous perfusion studies of the rotator cuff have demonstrated an area of hypovascularity in the distal part of the supraspinatus tendon. This has been implicated in the pathogenesis of its rupture. We performed a quantitative histological analysis of the vascularity of the tendons of supraspinatus and infraspinatus. Vessel number, size and the percentage of the tendon occupied by vessels were measured at 5 mm intervals from the humeral insertions to the muscle bellies. Both tendons were hypovascular in their distal 15 mm. No significant difference was demonstrated between the vascularity of supraspinatus and infraspinatus. We conclude that factors other than vascularity are important in the pathogenesis of supraspinatus rupture

1. Three cases of localised deposition of calcium salts deep to the origin of the common extensors of the forearm with acute symptoms clinically indistinguishable from "tennis elbow" are described. 2. Reports of nine similar cases have been found in the literature. 3. It is suggested that "tennis elbow" is caused by a lesion, probably an adventitial bursa, in the tissue space between the tendon of origin of the forearm extensors and the capsule of the radio-humeral joint; and that it is the sudden precipitation of calcium phosphate at this site which causes the lesion here described. 4. Acute calcification near the elbow joint is compared with the similar calcification which may occur in the insertion of the supraspinatus tendon. 5. Operative treatment is advised

We describe 11 cases of posterior fracture-dislocation of the shoulder that required open reduction and fixation. Difficulties with access through anterior approaches led us to use the superior subacromial approach. This is an extension of the approach often used to expose the rotator cuff; the joint is opened by splitting the supraspinatus tendon 5 mm behind the cuff interval. The glenoid, proximal humerus and any fracture fragments can be seen from above, allowing reduction of the dislocation and osteosynthesis to be performed with minimal risk of damage to the humeral head and its blood supply. The proximity of the axillary nerve limits the exposure of the proximal humeral shaft. The superior subacromial approach is ideal for posterior dislocation with fracture of the articular segment, but is not suitable when there is a fracture of the proximal humeral shaft

Ninety-seven patients suffering from painful arc syndrome of the shoulder were studied. Local anaesthetic and radiographic contrast investigations were carried out. One-third of the patients had lesions in the posterior part of the rotator cuff which resolved after injections of local anaesthetic and steroid. One-third had anterior lesions in the subscapularis tendon: almost all resolved under the same regime but two required division of the coraco-acromial ligament. The remaining third had lesions of the supraspinatus tendon, usually associated with degeneration of the acromio-clavicular joint: most of these failed to gain relief from the local anaesthetic and steroid. Twenty-two operations were performed either by a transcromial or by a deltoid splitting approach. Excision of the outer end of the clavicle and division of the coraco-acromial ligament abolished the pain in most cases

INTRODUCTION. Rotator cuff tears are common injuries which often require surgical repair. Unfortunately, repairs often fail [1] and improved repair strength is essential. P2 Porous titanium (DJO Surgical, Austin TX) has been shown to promote osseointegration [2,3] and subdermal integration [4]. However, the ability of P2Porous titanium to aid in supraspinatus tendon-to-bone repair has not been evaluated. Therefore, the purpose of this study was to investigate P2 implants used to augment supraspinatus tendon-to-bone repair in a rat model [5]. We hypothesized that supraspinatus tendon-to-bone repairs with P2 implants would allow for ingrowth and increased repair strength when compared to standard repair alone. METHODS. Thirty-four adult male Sprague-Dawley rats were used (IACUC approved). Rats received bilateral supraspinatus detachment and repair with one limb receiving P2 implant. Animals were sacrificed at time 0 (n=3), 2 weeks (n=8), 4 weeks (n=9) and 12 weeks (n=14). Limbs were either dissected for histological and SEM analysis or mechanical testing as described previously [5]. Specimens for histology and SEM were embedded in PMMA for tissue-implant interface analysis. Specimens were first viewed in SEM under BSE to detect bony ingrowth, then stained with Sanderson's Rapid Bone Stain and viewed under transmitted and polarized light for tissue ingrowth. Comparisons were made using Student's t-tests with significance at p≤0.05. RESULTS. No differences in cross-sectional area were detected at any time point (Fig 1A). Percent relaxation was significantly increased in the P2 group at 2 weeks, but not at 4 and 12 weeks (Fig 1B). Maximum load was significantly increased in the P2 group at 2 weeks, but not at 4 weeks (Fig 1C – maximum load not reported due to failure at grip at 12 weeks). Modulus was significantly increased in the P2 group at 4 weeks, but not at 2 or 12 weeks (Fig 1D). No differences were detected in stiffness at any time point (data not shown). BSE analysis demonstrated bone ingrowth (Fig 2) and histological analysis showed soft tissue integration (Fig 3). DISCUSSION. Results indicate superior mechanical properties in the P2 group at 2 and 4 weeks, and tissue ingrowth at all time points. Importantly, at 2 weeks, the P2group had 76% increased maximum load compared to standard repair. As supraspinatus tendon re-tears are extremely common early [1] and occur at the tendon-to-bone interface, this finding supports the reduction of re-tear risk with the P2 implant. Although no differences were detected in maximum load at 4 weeks, the increase at 2 weeks denotes that P2 implants improved early tendon-to-bone healing. Additionally, at 4 weeks, the P2 implant group had significantly increased elastic modulus, further supporting increased mechanical properties due to the P2 implant. Clinically, improved early healing might allow faster rehabilitation and associated recovery. This study demonstrates that the P2 implant improves tendon-to-bone healing up to 4 weeks (with no detrimental effects at longer time points), suggesting that P2 porous titanium may be of benefit for use in clinical rotator cuff repairs

The aim of this study was to find evidence of tissue hypoxia and apoptosis (programmed cell death) have on a human model of rotator cuff failure. We studied twenty seven patients with no tear mild impingment (3), no tear moderate impingment (3), no tear severe impingment (3), partial tear (3), small tear (3), moderate tear (3), large tear (3), massive tear (3) and control (3) who were undergoing shoulder arthroscopy, subacromial decompression and potential rotator cuff repair. A supraspinatus tendon biopsy was taken during debridement/repair on all cases (ethics number C01.071). Control tendon was obtained from the subscapularis tendon of patients undergoing stabilization surgery. Biopsies were analysed using two immunocytological techniques. A monoclonal antibody against BNIP-3 (a pro-apoptotic marker of hypoxia) and TUNEL (an apoptotic marker). An immunofluorescent nuclear counterstain DAPI (4 6-Diamidino-2-phenylindole dihy-drochloride) was used to stain all cells. Positive cells and total cell number were then counted in 10 high powered fields per section. The results showed a significant increase in BNIP-3 expression in the cuff tears compared with intact tendons. This increase was least in the massive tears. Apoptosis increases from mild impingement to massive cuff tears (mean 7.3% to 21%)

Aims: The roentgenologic morphology of symptomatic calcified deposits of the rotator cuff can be classified according Gärtner (1993, Z Orthop Ihre Grenzgebiete 131: 461–469). This classification influences therapeutic procedures and prognosis of clinical outcome in these patients. In the present study intraoberserver-reproducibility and interobserver-reliability of Gärtner’s classification were tested. Methods: Plane radiographs of 100 patients with calcifications of the supraspinatus tendon were classified according the criteria of Gärtner by six independent observers twice within four months. Intrao-berserver-reproducibility and interobserver-reliability were calculated by means of Cohen’s-kappa-index. Results: Kappa-values of intraoberserver-reproducibility had a mean of 0.4208 (SD 0.1299), kappavalues of interobserver-reliability were 0.490 for the first and 0.474 for the second classification. Conclusions: Determination of intraoberserverreproducibility gave insufficient to satisfactory results, interobserver-reliability was sufficient. The clinical use of Gärtner’s classification to plan therapeutic procedures or to determine clinical prognosis in patients with calcifying tendinitis can be recommended only with limitations

The objective was to seek evidence of hypoxia in early human tendinopathy and thereafter, to explore mechanisms whereby tissue hypoxia may regulate apoptosis, inflammatory mediators and matrix regulation in human tenocytes. Fifteen torn supraspinatus tendon (established pathology) and matched intact subscapularis tendon (representing ‘early pathology’) biopsies were collected from patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from 10 patients undergoing arthroscopic stabilisation surgery. Markers of hypoxia were quantified by immunohistochemical methods. Human tendon-derived primary cells were derived from hamstring tendon tissue obtained during hamstring tendon ACL reconstruction. The impact of hypoxia upon tenocyte biology ex vivo was measured using quantitative RT-PCR, multiplex cytokine assays, apoptotic proteomic profiling, immunohistochemistry and annexin V FACS staining. Increased expression of HIF 1a, Bcl-2 and clusterin (hypoxic and apoptotic markers) was detected in subscapularis tendon samples compared to both matched torn samples and non matched control samples (p<0.01). Hypoxic tenocytes exhibited increased production of proinflammatory cytokines (p<0.001), altered matrix regulation (p<0.01) with increased production of Collagen type III operating through a MAPK dependent pathway. Finally, hypoxia increased expression of several mediators of apoptosis and thereby promoted tenocyte apoptosis. Hypoxia promotes expression of proinflammatory cytokines, key apoptotic mediators and drives matrix component synthesis towards a collagen type III profile by human tenocytes. We propose hypoxic cell injury as a critical pathophysiological mechanism in early tendinopathy offering novel therapeutic opportunities in the management of tendon disorders

Age-related localised deposition of amyloid in connective tissue has been found in degenerative articular and periarticular tissue. Biopsies of the supraspinatus tendon of 28 patients undergoing repair of the rotator cuff were analysed histologically for the presence of localised deposition of amyloid. There was a long history of impingement in 20 patients, and eight patients had suffered an acute traumatic tear with no preceding symptoms. Localised deposition of amyloid identified by Congo Red staining was detected in 16 samples (57%). Amyloid was present in 14 (70%) of the degenerative tears, but in only two (25%) of the acute tears. Immunohistochemical staining showed that the amyloid deposits were positive for P component, but negative for κ and λ light chains, prealbumin, and β2 microglobulin. Critical electrolyte staining revealed highly-sulphated glycosaminoglycans at sites of deposition of amyloid. The presence of localised deposition of amyloid in tears of the rotator cuff is likely to represent irreversible structural changes. These findings support the theory that impingement and tears are due to intrinsic degenerative changes within the tendons of the rotator cuff

The aim of this study was to understand the role tissue hypoxia and apoptosis have on a human model of rotator cuff failure. We studied twenty seven patients with no tear mild impingment (3), no tear moderate impingment (3), no tear severe impingment (3), partial tear (3), small tear (3), moderate tear (3), large tear (3), massive tear (3) and control (3). A supraspinatus tendon biopsy was taken during debridement/repair in all cases (ethics no. C01.071). Control tendon was obtained from the subscapularis tendon of patients undergoing stabilization surgery. Biopsies were analysed using two immunocytological techniques. A monoclonal antibody against BNIP-III (a marker of hypoxia) and TUNEL (Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling – an apoptotic detection process). An immunoflorescent counterstain DAPI (4′,6-diamidino-2-phenylindol) was used to stain all cells. Positive cells and total cell number were then counted in 10 high powered fields. The results showed a significant increase in BNIP-III expression in the cuff tears compared with intact tendons. This increase was least in the massive tears. Apoptosis increases from mild impingment to massive cuff tears (mean 7.3% to 21%) In conclusion, as tear size increases, the viability of the tendon reduces with increasing hypoxia and apoptosis

Introduction: Reconstruction of the original footprint of the supraspinatus tendon is mandatory in achieving proper clinical result after reconstrucitve rotator cuff surgery. Methods: Twenty four cadaveric sheep shoulder and 12 live sheep sacrificed 3 months after rotator cuff reconstruction were tested. Arthroscopic transosseous technique and double row techniques were compared according to static load immediately after reconstruction (sheep cadaver) and after tissue healing took place (in vivo on sheep). In clinical work we analysed results of 120 patients operated on by the senior author employing different arthroscopic Methods: of rotator cuff reconstructionas. Results: Transosseous technique and double row technique have comparable biomechanical primary ultimate load to failure (160 N and 137 N comparatively) and equal ultimate load to failure after the tissue heals (302 N and 246 N respectively). Immediately after the reconstruction in double row group we noticed significant fragility in comparison to elasticity of the tendon-bone complex in transosseous group. We operated 67 shoulders (56%) with arthroscopic transosseous technique. We did not noticed complications of bone anchor, but in two patients we had rerupture of sutures that had to be reoperated on. Discussion: Arthroscopic transosseous technique uses less amount of bone anchors, optimaly reconstructs “footprint”, and has equal ultimate static load to failure as double row technique. But, double row technique is much more fragile than transosseous method in immediate postoperative period. Arthroscopic transosseous technique is technicaly demanding procedure that guarantee optimal clinical result

The supraspinatus tendon (SP) often ruptures. Gray established that the tendinous insertion always attaches to the highest facet of the greater tubercle of the humerus. Our osteological study of 124 shoulders in men and women between the ages of 35 and 94 years refocuses on the humeral insertion of the SP in relation to infraspinatus (IS) and teres minor (TM). We found type-I SFs (cubic) in 53 shoulders (43%) and type-II SFs (rectangular or oblong) in 21 (17%). Type-III (ellipsoid) SFs were present in 20 shoulders (16%) and type-IV (angulated or sloping) in 11 (9%). SFs were type V (with tuberosity) in 12 shoulders (10%) and type VI (pitted) in three (2%). The facet area of the SP, IP and TM varied from 49 mm, 225 mm and 36mm2. Of the three muscles, the IS facet was consistently the largest (p < 0.05) and shaped rectangularly. The SP inserted in a cubic or rectangular facet format in 75% of people. SP facet-size may relate to tendon strength, degeneration and rupture. This information may contribute to the understanding of tears of the rotator cuff

Summary Statement. The peripheral neuronal phenotype is significantly altered in rotator cuff tendinopathy (RCT) with a clear upregulation of the Glutaminergic system being present in disease. Introduction. Shoulder pain is the third most frequent cause of chronic musculoskeletal pain in the community and is usually caused by rotator cuff tendinopathy (RCT). The central and peripheral nervous system play an important role in both tissue homoeostasis and tendon healing. The Glutaminergic system is of key importance in driving the peripheral and central neuronal changes which increase the body's sensitivity to pain (1, 2). No study to date has investigated the role of the glutaminergic system in human RCT. We hypothesised that the peripheral neuronal phenotype would be altered in RCT, and would vary according to disease stage as measured by size of tear. The term ‘peripheral neuronal phenotype’ is used to refer to refer to specific characteristics of the peripheral nervous system, neuronal mediators and the receptors for these mediators in peripheral tissue. Methods. Rotator cuff tendon specimens were obtained from 64 patients undergoing the surgical repair of rotator cuff tears. Control supraspinatus tendon was obtained from 10 patients undergoing surgery for anterior instability using an ultrasound guided biopsy technique. Patients with rotator cuff tears were divided into 2 groups: the small/medium group (≤ 3cm size) and the large/massive group (>3cm size). The tendon tissue was histologically stained using Haematoxylin and Eosin, and immunohistochemically stained with primary antibodies visualised using 3, 3′-diaminobenzidine (DAB). Image analysis was performed blindly by 2 observers using Image-J to quantify the amount of DAB positive staining. Data was non-parametric in distribution and Mann-Whitney U tests were carried out using SPSS with significance levels set at a minimum of p<0.025. Results. There were significant changes in the peripheral neuronal phenotype in RCT. The Glutaminergic system was significantly up-regulated with an increase in Glutamate and changes in several related receptors in disease versus control (p<0.01). The standard deviation in nuclei count and mean cell nuclear area were both increased in disease (p<0.01) compared to controls. Tendon vascularity and cell proliferation were reduced in disease vs control (p<0.01). There were no significant correlations between pain scores and the peripheral tissue markers. Discussion/Conclusion. The peripheral neuronal phenotype is significantly altered in rotator cuff tendinopathy (RCT) with clear changes in the Glutaminergic system in disease. These findings are novel and improve our understanding of pain and tissue healing in RCT, potentially providing novel therapeutic targets

Tendon is a bradytrophic and hypovascular tissue, hence, healing remains a major challenge. The molecular key events involved in successful repair have to be unravelled to develop novel strategies that reduce the risk of unfavourable outcomes such as non-healing, adhesion formation, and scarring. This review will consider the diverse pathophysiological features of tendon-derived cells that lead to failed healing, including misrouted differentiation (e.g. de- or transdifferentiation) and premature cell senescence, as well as the loss of functional progenitors. Many of these features can be attributed to disturbed cell-extracellular matrix (ECM) or unbalanced soluble mediators involving not only resident tendon cells, but also the cross-talk with immigrating immune cell populations. Unrestrained post-traumatic inflammation could hinder successful healing. Pro-angiogenic mediators trigger hypervascularization and lead to persistence of an immature repair tissue, which does not provide sufficient mechano-competence. Tendon repair tissue needs to achieve an ECM composition, structure, strength, and stiffness that resembles the undamaged highly hierarchically ordered tendon ECM. Adequate mechano-sensation and -transduction by tendon cells orchestrate ECM synthesis, stabilization by cross-linking, and remodelling as a prerequisite for the adaptation to the increased mechanical challenges during healing. Lastly, this review will discuss, from the cell biological point of view, possible optimization strategies for augmenting Achilles tendon (AT) healing outcomes, including adapted mechanostimulation and novel approaches by restraining neoangiogenesis, modifying stem cell niche parameters, tissue engineering, the modulation of the inflammatory cells, and the application of stimulatory factors.

Cite this article: Bone Joint Res 2022;11(8):561–574.

This study was carried out to determine the incidence of shoulder injuries in the ipsilateral shoulder of patients who attended our unit with fractures of the humeral diaphysis. This was a prospective study. 22 patients with fractures of the humeral diaphysis had an early (within 10 days of injury) MRI scan of the shoulder. The contralateral shoulder was also scanned as an internal control. There were 10 male and 12 female patients. The average age was 45 years. 20 were treated non-operatively, and 2 had retrograde intra-medullary nailing of the humerus. 6 patients in our study had a symmetrical MRI scan. The remaining 16 patients had some acute abnormality evident in the ipsilateral shoulder. 11 patients had a significant subacromial bursitis. 2 of these patients had a tear of the supraspinatus tendon. 1 patient had an undisplaced fracture of the coracoid process. The remaining 4 patients had significant AC joint inflammation, 3 being acute, the 4th being acute-on-chronic. This study shows a high incidence of asymmetrical MRI scans, indicating a definite shoulder injury sustained at the time of the fracture of the humeral diaphysis. We therefore surmise that shoulder pain and dysfunction post antegrade intra-medullary nailing of the humerus may not be due to iatrogenic causes, but may in fact result from concomitant ipsilateral shoulder injury. To our knowledge, this is the first study demonstrating such an association

Introduction. Many literatures regarding more specific tests to diagnose the supraspinatus tendon injuries and the best rehabilitation methods to strengthen the supraspinatus have been published. However, conflicting results have been reported. 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography (PET) has been recently used to assess skeletal muscle activities in various fields. Purpose. To evaluate & compare the metabolic activities of deltoid & rotator cuff muscles after the full-can & empty-can exercises using PET-CT. Materials and Methods. Ten healthy volunteers (age 27–34/mean 29.8 ± 2.7) with no history of shoulder pain and diabetes mellitus participated in this study. After FDG injection, both arms were maintained in the position of empty can and full can for ten minutes respectively. PET-CT was performed at forty minutes after the injection. The maximum standardized uptake value (SUV) was measured in the anterior, middle and posterior deltoid, supraspinatus, subacapularis and infraspinauts on the entire axial images. Results. The middle deltoid and subscapularis showed significantly greater activity during the empty-can exercise than during the full-can exercise (P=.006 and P=.003 respectively). The muscular activity of the supraspinatus also increased during the empty-can exercise than during the full-can exercise, although no statistical difference existed between two exercises. Six cases of eight cases who had increased activity of the subscapularis had increased activity in superior one half of the subscapularis than in lower one half of it, although there is no significant difference between two portions. Conclusion. The Empty-can exercise requires more strength of the middle deltoid, subscapularis and supraspinatus to keep the arm in internal rotation. The increased activity of the middle deltoid and subscapularis muscles after the empty-can exercise can make the empty-can test less specific to the supraspinatus muscle. The empty-can test can induce pain and weakness due to the subscapularis pathology. The full-can test can be used to test the function of the supraspinatus with the least amount of surrounding middle deltoid and subacapularis muslce activity

Aim To evaluate the functional results of rotator cuff function and integrity after arthroscopic excision of calcium and decompression with a minimum follow up of two years. Methods Between 2002 and 2004, sixty consecutive patients with calcific tendinitis underwent arthroscopic excision of calcium and subacromial decompression. Their average age was 51 years (range 28 to 78). The male to female ratio was 2:3. All patients were retrospectively reviewed by an independent observer. Functional outcome was assessed objectively by Constant scoring system and subjectively by Oxford Shoulder Questionnaire. The integrity of the rotator cuff was assessed by ultrasound scan. (Sonosite). Operative technique After arthroscopic subacromial decompression, all calcific deposits were excised with an arthroscopic rotating blade. The resultant cuff defect was left to heal and no cuff repair was performed. Other intra-articular pathology including SLAP lesions were treated at the same time. Postoperatively, early mobilization of the shoulder was encouraged. Results The mean Constant score at follow-up was 82 (range 63 to 100). Fifty-four patients (90%) had good or excellent results and six patients (10%) had a fair score. Ultrasound assessment showed intact rotator cuff with no residual defect in forty-three patients, partial thickness tears in twelve, and small full thickness tears in three. Two patients had recurrence of calcium. Only four of the fifteen patients who had ultrasound evidence of rotator cuff tear were symptomatic. Conclusion Arthroscopic excision of calcium and subacromial decompression is an effective method of pain relief in calcific tendinitis of the shoulder. 75% of the rotator cuff appeared to have healed after two years. Of the remaining 25% patients who had a defect in their supraspinatus tendon, only 6% remain symptomatic

There is no non-invasive gold standard for measuring gap formation following rotator cuff repair; re-tears are reported both on MRI and Ultrasound. Roentgen Stereophotogrammetric Analysis (RSA) has previously been used to monitor microscopic migration of markers in rigid bodies. We present a novel RSA technique using a combination of 1mm tantalum beads and metal sutures to allow accurate monitoring of gap formation following rotator cuff repair. The RSA system combines a commercially made calibration cage with software developed at Imperial College. We verified the RSA system by analysing a movable glass phantom and comparing the data with precise physical measurements of the same object: it identified a 2mm distraction of the phantom to within 0.05mm. In vitro work involved cadaveric human shoulders. We placed three 1mm RSA tantalum beads in the greater tuberosity and three metal sutures in supraspinatus tendon. We then created a tear in supraspinatus at its insertion into the greater tuberosity. We were able to show that RSA images taken before and after the tear correlated closely with direct measurements. The processed data demonstrated movement associated with gap formation. We have performed two open rotator cuff repairs using trans-osseous sutures. During surgery RSA markers were inserted into the shoulder to allow post-operative monitoring of the repair (guided by the in vitro work). Direct measurements of the distance between markers each side of the repair were taken intra-operatively (T=O). RSA images were taken immediately post-operatively (T=1 hours), day 3, day 14, and day 84. The RSA data suggests gapping of typically 3mm may have occurred at the repair sites in both patients. Ultrasound imaging was performed at the same intervals by consultant musculoskeletal radiologists blinded to the RSA data. Preliminary results correlating the two modalities suggest that ultrasound can visualise gap formation accurately even immediately post-operatively

The February 2023 Shoulder & Elbow Roundup³⁶⁰ looks at: Arthroscopic capsular release or manipulation under anaesthesia for frozen shoulder?; Distal biceps repair through a single incision?; Distal biceps tendon ruptures: diagnostic strategy through physical examination; Postoperative multimodal opioid-sparing protocol vs standard opioid prescribing after knee or shoulder arthroscopy: a randomized clinical trial; Graft healing is more important than graft technique in massive rotator cuff tear; Subscapularis tenotomy versus peel after anatomic shoulder arthroplasty; Previous rotator cuff repair increases the risk of revision surgery for periprosthetic joint infection after reverse shoulder arthroplasty; Conservative versus operative treatment of acromial and scapular spine fractures following reverse total shoulder arthroplasty.

Two fixation devices for rotator cuff repair were compared in a sheep model. Surgical transection of the supra-spinatus tendon insertion was repaired using metallic OBL suture anchors or Suretac II anchors. Twelve weeks postoperatively the repair site was assessed using histology, polarized light microscopy and biomechanical testing. No important differences were found between these two repair methods. The purpose of this study was to compare traditional rotator cuff fixation devices with bioabsorbable press-fit tacks. Sixteen sheep were assigned to OBL (n=8) or Suretac (n=8) treatment groups. Four sheep shoulder joints were used as unoperated controls. Treated sheep underwent general anesthesia and a lateral arthrotomy using aseptic technique to allow transection of the supraspinatus tendon insertion. The tendon-bone interface was repaired with two fixation devices according to the manufacturer’s directions. After recovery from anesthesia the sheep were maintained in small pens for twelve weeks. After sacrifice, muscle-tendon-bone blocks were prepared for mechanical testing. The specimen underwent a preload of 25N, followed by cyclic loading (10–50N x10), then loading at 480mm/min until failure. The remaining bone-tendon interface was fixed, embedded in plastic and 100μ undecalcified histological sections were cut, polished and stained. All tendons had healed to the humerus and the repair site was two to three times larger than unoperated controls. There were no significant differences between the two treatment groups with respect to maximum load, modulus, and energy per unit area. Histological analysis is ongoing. These data suggest that these two fixation methods are functionally equivalent in this model. Press-fit fixation devices do not knot tying and they can be inserted arthroscopically so they are a convenient fixation method. This study confirms that press fit anchors and metallic anchors with sutures are equivalent for repair of bone-tendon interfaces. Funding: Smith & Nephew supplied the fixation devices for this project. Thanks to Deb McWade for technical assistance

Aims

Rotator cuff (RC) tears are common musculoskeletal injuries which often require surgical intervention. Noninvasive pulsed electromagnetic field (PEMF) devices have been approved for treatment of long-bone fracture nonunions and as an adjunct to lumbar and cervical spine fusion surgery. This study aimed to assess the effect of continuous PEMF on postoperative RC healing in a rat RC repair model.

Aims

This study compared patients who underwent arthroscopic repair of large to massive rotator cuff tears (LMRCTs) with isolated incomplete repair of the tear and patients with incomplete repair with biceps tendon augmentation. We aimed to evaluate the additional benefit on clinical outcomes and the capacity to lower the re-tear rate.

Aims

A revision for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) has a major effect on the patient’s quality of life, including walking capacity. The objective of this case control study was to investigate the histological and ultrastructural changes to the gluteus medius tendon (GMED) in patients revised due to a PJI, and to compare it with revision THAs without infection performed using the same lateral approach.

Aims

The aim of this study is to provide a detailed description of cases combining bridging patch repair with artificial ligament “internal brace” reinforcement to treat irreparable massive rotator cuff tears, and report the preliminary results.

Purpose of the study: Muscles contract after a full thickness tear their tendon. The muscle then undergoes atrophy and fatty degeneration. These changes produce effects well described by histology, computed tomography and magnetic resonance imaging (MRI). To date however, the correlation of this process with the future conractile force of the muscle and the prognosis after cuff repain has been poorly understood. Material and methods: Thirteen patients with a full thickness tear of the supraspinatus muscle were treated surgically by cuff suture. The shoulders were examined clinically and MRI. During the operation, the supra-scapular nerve was stimulated with a supramaximal voltage to obtain maximal muscle contraction which was measured. Biopsy specimens of the supraspinatus were taken before and after surgical repair in order to determine whether muscle activity during stimulation have any histological impact. The intraoperative measurements were compared with the MRI findings and the physical examination performed preoperative and at six weeks, six months and twelve months after surgery. Results: Maximal force of the supraspinatus muscle was 200N, which is greater than the force of a direct suture repair. The maximal force was clearly correlated with muscle atrophy and fatty degeneration: by surface area, force was 12N/cm. 2. for Goutallier grade 3 and 42 N/m. 2. for grade 0. Five of the thirteen repairs ended with a secondary tear, the muscle in four of the five patients was among the six strongest muscles. The fifth case was the weakest muscle of all. The histological study revealed a larger quantity of lipofuchin in the muscle with atrophy and a change in the fiber structure. Analysis of the results did not demonstrate any lesions caused by the tension during the operation. MRI demonstrated one case of repair without secondary tear, the fatty infiltration had not improved and the atrophy only partially. In muscles with secondary tears, atrophy and fatty degeneration progressed significantly. Discussion and conclusion: There is a risk of rupture of the supraspinatus tendon in the event of muscle atrophy but also for good quality muscle. The capacity of a muscle to develop force strongly depends on the state of atrophy and fatty degeneration. Atrophy can regress after reconstruction without secondary tear, but fatty degeneration is irreversible

The practice of rotator cuff repair rapidly moves towards arthroscopic techniques especially for single tendon tears. Although the clinical results are relatively well established, the structural results of open rotator cuff repair and their correlation with the clinical outcome are poorly known. In order to provide a baseline for future studies using other repair techniques, this study was carried out to assess the structural changes in the repaired musculotendinous unit and to correlate these findings with the clinical outcome after rupture and repair of an isolated full thickness single tendon tear of the rotator cuff. To prospectively assess the quality of an open rotator cuff tendon repair technique, to determine how structural changes of rotator cuff muscles are affected by tendon repair, and to correlate the structural results of MRI studies with the clinical outcome. Direct open repair of a complete, isolated single tendon tear of the rotator cuff resulted in significant improvement in function and objective evidence of tendon healing on MRI. Successful direct repair was not associated with recovery of preoperative muscular atrophy or fatty infiltration when comparing Goutallier stage fatty infiltration between pre and postoperative patients. The age and gender-adjusted Constant score increased significantly from an average of 63.9% preoperatively to 94.5% postoperatively (p< 0.0001). Pain improved significantly from 6.8 points to 13.2 points on a visual analogue scale. (p< 0.0001). Activities of daily living increased from 11.2 points preoperatively to 17.9 points postoperatively (p< 0.0001). Anterior elevation, abduction and internal rotation improved significantly for subscapularis and supraspinatus repairs, but there was no significant change in external rotation. The overall rerupture rate was 12.5%. There was no significant improvement or recovery of muscular atrophy or fatty infiltration after tendon repair. Thirty-two consecutive open repairs of a single tendon tear of the rotator cuff were analysed. The supraspinatus tendon was involved in twenty-two patients and the subscapularis tendon in ten patients. All tendons were repaired using an open technique, a modified Mason-Allen suturing technique, and transosseus fixation with non-absorbable suture material knotted over a bone augmentation device

Rotator cuff tears are common in middle-aged and elderly patients. Despite advances in the surgical repair of rotator cuff tears, the rates of recurrent tear remain high. This may be due to the complexity of the tendons of the rotator cuff, which contributes to an inherently hostile healing environment. During the past 20 years, there has been an increased interest in the use of biologics to complement the healing environment in the shoulder, in order to improve rotator cuff healing and reduce the rate of recurrent tears. The aim of this review is to provide a summary of the current evidence for the use of forms of biological augmentation when repairing rotator cuff tears.

Cite this article: Bone Joint J 2024;106-B(9):978–985.

Purpose. Full-thickness tendon tears of the supraspinatus (SP) are common and can have a significant impact on shoulder function. To optimally treat supraspinatus tendon tears an accurate understanding of its musculotendinous architecture is needed. We have previously shown that the architecture of supraspinatus is complex. It has architecturally distinct regions: anterior and posterior, each of which is further subdivided into superficial, middle and deep parts (Kim et al., 2007). Data of FBL and PA of the torn supraspinatus could enhance clinical decision making and guide rehabilitative treatments (Ward et al., 2006). Currently, however, in vivo US quantification of the fiber bundle architecture of the distinct regions of supraspinatus in subjects with full-thickness tendon tears has not been investigated. PURPOSE: To quantify architectural parameters within the distinct regions of supraspinatus in subjects with a full-thickness tendon tear using the US protocol that we previously developed (Kim et al., 2010), and to compare findings with age and gender matched normal controls. Method. Twelve SP from eight subjects, mean age 576.0 years, were scanned using an US scanner (12 MHz). The SP was scanned in relaxed and contracted states. For the contracted state, SP was scanned with the shoulder in neutral rotation and 60 of active abduction. Fiber bundles of the anterior region (middle and deep) and posterior region (deep) could be visualized and measured. Muscle thickness, FBL, and PA were computed from US scans. Data was analyzed using Mann-Whitney and Wilcoxon Signed Rank Tests (P<0.05). Results. Intra-and inter-rater measurements of FBL were strongly correlated with no significant difference between measurements (P<0.001). In the anterior region, mean FBL did not significantly differ between the pathologic subjects and normal controls. In the pathologic subjects, mean PA was smaller compared to normal controls. The difference was significant between the subjects with a tear and retraction and normal controls (P<0.05). For the posterior region, mean FBL was shorter in the pathologic subjects compared to normal controls. The difference was significant between the subjects with a tear and retraction and normal controls (P<0.05). Conclusion. Findings suggest that significant FBL and PA changes are found with full-thickness tendon tears of SP and different regions of the muscle are impacted differently. Pennation angles are largely impacted in the anterior region and FBL in the posterior. The presence of tendon retraction was found to be related to the amount of change in architectural parameters. Data from this study may be useful to model muscle-joint behavior of the pathologic shoulder. This US protocol may be beneficial to carry out a larger study to determine which comes first, architectural changes in the muscle, or tendon tearing. If we identify changes in muscle architecture predate tendon pathology, we could develop techniques to prevent tendon tearing

Summary. Strong mechanical fixation is critical to the success of rotator cuff repairs. In this comparative study in cadaveric shoulders, single-tendon full-thickness supraspinatus tears were repaired using two different types of PEEK knotless suture anchors-ReelX STT (Stryker) and Opus Magnum PI (Arthrocare)-using a single-row technique in both instances. Cyclic testing was performed followed by loading until mechanical failure. No significant difference was observed in gap formation, measured as the distance between the supraspinatus tendon and bone at the repair site, during cyclic loading. However, the maximum load was statistically higher for repairs with the ReelX anchor. Purpose. The objective of this study was to compare the gap formation during cyclic loading and maximum repair strength of single-row full thickness supraspinatus repairs performed using two different types of PEEK knotless suture anchors in a cadaveric model. Methods. Nine matched pairs of cadaveric shoulders were used in this study. All soft tissue was removed except for the supraspinatus, and a full thickness tear was formed. Single-row repairs were performed with two anchors per repair using either the Opus Magnum PI (Arthrocare) or the ReelX STT (Stryker). The specimens were mounted to an Instron at 45° to simulate an anatomic direction of load, and fiducial markers were placed on the repair in anterior and posterior positions. A 10 N preload was applied and held for 60 seconds, and then the tendon was cycled from 10 N to 90 N at 0.25 Hz for 500 cycles, followed by load to failure at 1 mm/s. A video digitizing system was used to track the markers and measure gap formation during loading. Gap formation was calculated by subtracting the distance between the markers at 10 N preload from the maximum displacement at 5 and 500 cycles. Paired t-tests were used to compare the cyclic displacement and max load. Results. One specimen from each of two matched pairs (one from each anchor group) failed during cyclic loading, leaving seven matched pairs for analysis. No significant difference was found in cyclic displacement between the two groups in either anterior or posterior positions at 5 and 500 cycles. However, maximum load to failure was significantly greater for repairs performed with the ReelX STT anchors (289N ± 57N) as compared to the OPUS anchors (178N ± 36N), with a p=0.009. Conclusions. These results suggest that the anchor type chosen for cuff repairs may affect the overall stability of the repair. Achieving stable fixation is critical for promoting healing of the tendon back to bone and to the long-term success of the repair, and using anchors that provide stronger fixation may decrease the occurrence of post-surgical tears and instability. The ReelX STT anchor outperformed the Opus Magnum PI anchor in terms of supporting significantly higher loads before failure, potentially leading to stronger repairs clinically

The incidence of rotator cuff tears increases with age, thus the rotator cuff tear is often associated with osteoporotic or osteopenic bone in the proximal humerus, especially with female patients. For testing of fixation devices such as suture anchors used in rotator cuff repair often animal bones are used. They are easily to obtain, inexpensive and some have been found to be similar to human bone. But can we rely on the results drawn from these studies in our daily surgical practice?. The purpose of this study was to compare the trabecular bone mineral density, the trabecular bone volume fraction and the cortical layer thicknes in the greater tubercle in different species to evaluate their infiuence on primary stability of suture anchors under a cyclic loading protocol representing the physiologic forces placed on rotator cuff repairs in vivo. We hypothezised that maximum pullout forces as well as the modes of failure are different for a suture anchors in different humeri. The available three different types of anchor fixation design (screw: Spiralok 5mm, Super Revo 5mm, press-fit: Bioknotless RC, wedging: Ultrasorb) were tested. The bone mineral density (BMD) of the humeri was measured by a 64-slice-computed tomography system. Each anchor was tested individually until failure. The sutures were pulled at 135° to the axis of the humeral shaft, simulating the physiological pull of the supraspinatus tendon. Starting with 75 N the tensile load was gradually increased by 25 N after everey 50 cycles until failure of the anchor fixation system occurred. The ultimate failure load, the system displacement after the first pull with 75 N and the mode of failure were recorded. The ultimate failure loads of each anchor were different in the human osteopenic, human healthy, ovine and bovine humeri. The statistical significancies for pull out forces between the anchors varied from species to species. The biomechanical testing of suture anchors for arthroscopic rotator cuff repair in ovine and bovine humeri does not give reliable data that can be transferred to the human situation. The significances between the suture anchors found in ovine and bovine humeri are different from the results in human humeri. When taking the impaired bone quality of older patients into account the results from ovine and bovine humeri are even less predictable. We found a positive correlation between maximum failure load and cortical layer thickness for the Super Revo and the Ultrasorb anchor. The ultimate failure load seems to depend mainly on the cortical thickness and on the subcortical trabecular bone quality

Objectives. Although many clinical and experimental investigations have shed light on muscle atrophy and intramuscular accumulation of fat after rotator cuff disruption, none have reported on their onset in the absence of muscle retraction. Methods. In 30 rabbits, we detached one supraspinatus (SSP) tendon and repaired it immediately, thus preventing muscle retraction. The animals were killed in groups of 10 at one, two and six weeks. Both shoulders of 15 non-operated rabbits served as controls. We measured the weight and volume of SSP muscles and quantified the cross-sectional area of intramuscular fat (i-fat) histologically. Results. There was significant loss of muscle weight and volume after one week (p = 0.004 and 0.003, respectively), and two weeks (both p < 0.001) in the experimental group; which recovered to control values after six weeks. I-fat accumulated one week after immediate repair, greater than in the control group and statistically significant at the mid-part of the muscle (mean 2.7% vs 1.5%, p = 0.008). I-fat continued to accumulate up to six weeks at all sites of the SSP muscle (all 3, p < 0.001). More fat accumulated closer to the musculotendinous junction than at the mid-part after two and six weeks (p = 0.012 and 0.019, respectively). Conclusion. Muscle atrophy and i-fat accumulation occur early after SSP tendon tear and immediate repair. While early repair benefitted muscle recovery, it did not prevent fat accumulation. SSP muscle retraction was not essential to the muscle alterations. The divergent evolution of muscle and fat points to different pathophysiologies. Cite this article: Bone Joint Res 2014;3:117–22

1. The avascular zone in the tendon of the supraspinatus near its insertion was not seen in the other tendons comprising the rotator cuff, except for the superior portion of the insertion of the infraspinatus which, on occasions, showed a small avascular area. The biceps tendon, however, also showed an avascular zone as it coursed over the head of the humerus. It is suggested that the anatomical disposition of these tendons makes them subject to constant pressure from the head of the humerus, which tends to wring out the blood supply to these tendons when the arm is held in the resting position of adduction and neutral rotation. 2. Although this study did not produce any evidence that the relative avascularity of the tendons over a prolonged period could be indicted as the sole cause of the degenerative changes that so commonly occur, it was noted that the degenerative changes occurred first and that they were always most extensive in the areas of avascularity. It was also observed that the zones of relative avascularity preceded, and were not the result of, the degenerative changes. 3. With the onset of tendon degeneration, secondary vascular phenomena were observed. Firstly, there was a reaction that appeared to be a foreign body inflammatory response with the development of vascular tufts of granulation tissue. It was thought that these vascular changes were secondary to the breakdown in the tendons and were not the cause of the breakdown as previously suggested by Anderson and Moore. it was noted, moreover, that with the progression of degenerative changes in the supraspinatus tendon, the tendon became much attenuated and, as it did so, the zone of relative avascularity appeared to extend. This secondary shut-down of the vascular bed might well be caused by an increased tension in the tendon. In those tendons in which spontaneous rupture had occurred, it was noted that the major part of the tendon proximal to the rupture was avascular and showed evidence of much degenerative change. This study therefore suggests that in the operative repair of such lesions it is necessary to excise the degenerate avascular tendon in order to effect a sound repair. It is also suggested that detachment of the supraspinatus muscle from the supraspinous fossa in order to advance the whole muscle belly is the only technique possible to enable the surgeon to replace healthy tendon directly into bone, as suggested by Debeyre and his colleagues

Aims

Rotator cuff (RC) injuries are characterized by tendon rupture, muscle atrophy, retraction, and fatty infiltration, which increase injury severity and jeopardize adequate tendon repair. Epigenetic drugs, such as histone deacetylase inhibitors (HDACis), possess the capacity to redefine the molecular signature of cells, and they may have the potential to inhibit the transformation of the fibro-adipogenic progenitors (FAPs) within the skeletal muscle into adipocyte-like cells, concurrently enhancing the myogenic potential of the satellite cells.

Purpose: Synovium proliferation of rheumatoid arthritis (RA) is a key role in development of destruction in articular joints. Arthroscopic synovectomy is quite useful for resection synovium less invasively for RA patients. However there are few papers about shoulder joint synovectomy of rheumatoid arthritis. Ho-YAG laser is also effective to decrease synovium proliferation. The advantage of using Ho-YAG laser is effective to pannus even in deep zone of bone erosion. In this paper, we treated 13 shoulders of 11 patients of RA by using Ho-YAG laser to assess whether Ho-YAGH laser is effective in shoulder arthroscopic synovectomy of RA. Materials and Methods: We treated 13 shoulders in 11 patients of RA, including 8 in stage II, 4 in stage III, 1 in stage IV. The duration of RA is an average of 4, 6 years. The follow-up period is an average of 14 months. We compared CRP, DAS28 and MRI findings before and after surgery. Those patients were taking DMARDs such as MTX in 8 patients, steroid in 3 patients infliximab in 1 patient and etanercept in 1 patient. We used 4.0 mm arthroscope, VAPR and shaver for synovectomy. Ho-YAG laser set to 10W to bone erosion area to reach deep zone of pannus and to resect synovium. Results: We found villous synovium proliferation with vascularity in rotator interval and supraspinatus tendon in shoulder joint. In subacromial bursa, yellow fat tissue and white fibrous soft tissue was detected almost all shoulders. After synovectomy by using Ho-YAG laser, CRP was decreased from an average of 3.6 to 0.8 and DAS28 was also decreased an average of 5.4 to 3.7 at 14 month after surgery. MRI showed decreased pannus with synovium and joint destruction was not preceding after 14 month. Discussion: Ho-YAG laser is effective for using shoulder arthroscopic synovectomy especially to treat pannus in bone erosion. The amount of energy of Ho-YAG laser for synovectomy is not clear so far. We used 10W for 5 second in each area that could be effective to decrease pannus formation. We would further investigate in the basic experimental levels to confirm Ho-YAG laser efficacy

Purpose: Many different rotator cuff repairs have been advocated in previous publications without experimental evidence. Our aim was to mechanically test the static tensile properties and cyclical loading to failure of a single row lateral anchor repair and a double row medial and lateral anchor repair. Method: Fresh frozen cadaveric shoulders were mounted on a rig and a mini-open deltoid split used to visualise the supraspinatus. A standardised full thickness incision of 2 cms was made with a scalpel across the supraspinatus tendon. After the deltoid was repaired and specimens randomised, an arthroscopic rotator cuff repair was performed by the two senior authors in which the medial border of the tear was apposed to the lateral border using either a double or single row technique with a ‘Twinfix AB’ suture anchor. Once the repair had been performed, the gross specimens were dissected down to the rotator cuff musculature and the repair inspected. Those with associated cuff pathology were excluded from the experiment. Specimens were then mounted on a custom made rig to statically load each tendon simulating physiological loading of a repaired cuff defect in a post-operative 300 abducted position. The increase in tear size was then measured against time for 1 hour or to a point at which the mean tendon gap formation exceeded 5mm. Each specimen was then transferred to an Instron tensile testing machine to cyclically load to failure the supraspinatus musculotendinous unit. Each specimen was freeze clamped proximally in a specially designed clamp, whilst the humeral shaft was mounted at an angle of 300 of abduction. Results: The two groups had a distinct difference in tensile properties with the single row fixation developing a 5mm gap in under 30 minutes. After 1 hour, the gap formed in the double row specimens was less than 5mm. In cyclical loading, the single row failed at a lower load compared with the double row. In some double row specimens the tendon failed mid substance above 250N, rather than at the anchor-suture or suture-tendon interface. Conclusions: Our results suggest that the double row mattress technique has superior loading properties when tested with a simulated physiological load comparative to the normal post-operative setting

Purpose: The aetiology of primary omarthrosis is still unclear. Typical radiological changes are joint space narrowing and the development of caudal osteophytes. The objective of the study is the analysis of the joint space of the shoulder in four different age groups. Materials and Methods: Retrospective analysis of n=342 standardized X-rays (2002–2009) (true ap, axillary). Inclusion criteria: normal adulthood group I (n=60), instability group II (n=53), calcifying tendonitis of the supraspinatus tendon group III (n=109), advanced primary omarthrosis group IV (n=120). Measurement of joint space at three levels (ap: superior, central, inferior; axillary: anterior, central, posterior). Two independent measurements. Statistical analysis SPSS 17.0: U-Test acc. Mann and Whitney. Bivariate correlation analysis (Spearman), partial correlation analysis, intraclass correlation coefficient. Results: Mean age group I 17.84±1.54, group II 31.6±11.8, group III 48.2±8.0, group IV 66.43 ±9.74 (p=0.001). Measurement joint space: interobserver reliability excellent in the ap-projection (r=0.887–0.910) and in the axillary projection (r=0.879–0.886). Joint space group I: 4.79mm±0.84 superior ap, 4.28mm±0.75 central ap, 4.57mm±0.80 inferior ap, 6.59mm±1.44 anterior axillary, 6.12mm±1.09 central axillary and 7.03mm±1.17 posterior axillary; group II: 3.78mm±0.99 superior ap, 3.12mm±0.73 central ap, 3.38mm±0.80 inferior ap, 3.92mm±1.08 anterior axillary, 3.92mm±0.77 central axillary and 4.79mm±1.18 posterior axillary; group III: 3.43mm±1.06 superior ap, 2.87mm±0.80 central ap, 3.25mm±0.79 inferior ap, 3.95mm±0.83 anterior axillary, 3.34mm±0.84 central axillary and 4.05mm±0.84 posterior axillary; group IV: 2.00mm±1.40 superior ap, 1.47mm±1.07 central ap, 1.48mm±1.93 inferior ap, 3.01mm±2.22 anterior axillary, 1.08mm±1.12 central axillary and 1.17mm±1.04 posterior axillary. The differences between the four groups for the joint space width are all statistically significant with p< 0.001 (except the difference between group I and group II for ap-central, ap-inferior and axillary anterior). There is a significant negative correlation (r= −0,579–0,813) between the joint space width and patients age at all measured levels in both projections (p< 0.001). This negative correlation is only little smaller (r= −0,430–0,655) but still clearly significant for all measurements, if the patients with present osteoarthritis (group III) are excluded. Conclusion: The data of the study show a decrease of joint space width in group I–IV in all measurements. This effect is negatively correlated with age. The data suggest that the decrease in joint space with loss of cartilage cover is an age-dependant process which is independent from the presence of osteoarthritis. This is in contrast to historical findings but in concordance with recent basic studies about cartilage ageing

The indications for use of a glenoid component are: 1.) sufficient degenerative changes on the glenoid to expose the subchondral bone 2.) the glenoid should have sufficient glenoid bone stock to allow for secure and longterm fixation of the component, and 3.) the rotator cuff should be intact or repairable and the humeral head should be centred within the glenoid component. Other factors that secondarily affect the decision to use a glenoid component, include the patient’s age and activity level, which should be such that they are not likely to result in multiple revisions for glenoid wear or loosening. Given these factors most patients with osteoarthritis, the leading indication for prosthetic replacement for arthritis should undergo a total shoulder replacement. Patients with acute proximal humeral fractures, the overall leading indication for prosthetic arthroplasty, should have a hemiarthroplasty. Patients with rotator cuff tear arthropathy or crystalline arthropathy are indicated for hemiarthroplasty due to the massive irreparable cuff tears present in these conditions. Patients with rheumatoid arthritis have variable diseases affecting the rotator cuff and variable degrees of bone loss resulting in the need to individualise the indications for the use of a glenoid to the patient’s pathoanatomy. The reason for use of a glenoid component, when indicated, is the fact that pain relief and function is predictably better when compared to hemiarthroplasty for the same indication and pathoanatomy. Proper insertion of a glenoid component requires wide exposure of the glenoid fossa and bone preparation, which for most general orthopaedic surgeons is difficult and not reproducible. This is, in my opinion, the primary reason that hemiarthroplasty or bipolar arthroplasty is used for treatment of many patients with primary osteoarthritis. Both of these procedures result, on average, in a less favourable outcome than non-constrained total shoulder arthroplasty. Osteoarthritis is characterised by flattening and enlargement of the humeral head and is associated with peripheral osteophyte formation. Loss of articular cartilage results in eburnated bone and on the glenoid side posterior bone loss. Capsular contracture results in loss of passive arcs of motion, particularly anteriorly with loss of external rotation. Posterior subluxation of the humeral head can occur, associated with anterior soft tissue contracture and/or posterior glenoid bone loss. The severity of this pathoanatomy is variable among patients with primary osteoarthritis and each of these factors will have a variable effect on outcome of shoulder arthroplasty as well as the indication for hemiarthroplasty versus total shoulder arthroplasty. In a 2–7 year follow-up multicentre study using the DePuy Global Shoulder in 127 patients, those cases with osteoarthritis without humeral head subluxation, severe glenoid bone loss, or rotator cuff tears had the best results, for pain relief and function, with total shoulder arthroplasty. In patients with severe glenoid bone loss total shoulder has improved function when compared to hemiarthroplasty. This finding supports the data of others that demonstrate less favourable results of hemiarthroplasty for treatment of osteoarthritis in cases with eccentric glenoid wear. Patients with humeral head subluxation have less favourable results regardless of the use of a hemiarthroplasty or total shoulder arthroplasty. The presence of a full thickness reparable rotator cuff tear limited to the supraspinatus tendon does not adversely affect outcome or the ability to use a glenoid component. Patients with less than 10° of external rotation achieve statistically less postoperative forward flexion and external rotation than those patients with greater degrees of preoperative external rotation

Leakage after simple suture repair of rotator cuff tears depends on the overall preoperative fatty degeneration index (FDI) of the muscles and preoperative fatty degeneration (FD) of the infraspinatus. When the FDI is = 2, cuff leakage is always observed after repair. The risk of recurrent tears of the supraspinus is high if the FD of the infraspinatus is > 1. However if the FDI is very low or nil, the rate of recurrent tears is 15%. These tears can be explained by tension on sutures in macroscopically and histologically abnormal tendons. Purpose: The purpose of this study was to determine whether repair of rotator cuff tears using sutures without tension after removal of abnormal tendon stumps, a technique requiring tendon plasty, can improve the leakage rate. Material and methods: Total repair of 24 rotator cuff tears was performed without tension on the sutures after resection of at least one centimetre of the supraspinatus tendon stump. This consecutive series was studied prospectively. The tears involved the supraspinatus and the infraspinatus in ten cases, all three tendons in 13 cases and only the supraspinatus in one case. Mean preoperative FDI was 1.18 (0.5–2.16); pre-operative FD of the infraspinatus was a mean 1.19 (0–2). The supraspinatus stump was resected from the trochiter in 14 cases, on the apex of the head of the humerus in seven and facing the glenoid cavity in three. Repair required translation advancement of the supraspinatus in 24 cases, translation advancement of the infraspinatus in six (associated with a rhomboid flap) and a trapezeal flap in three cases. Postoperative leakage was assessed with arthroscan (n=23) and ultrasonography (n=1) at one year. Results: No leakage was observed in 20 of the 24 cuffs (83%). Recurrent tear of the supraspinatus was observed in three cases and in the supraspinatus and infraspinatus in one case each. The FDI of cuffs with recurrent tears (1.31) was not significantly greater than the FDI of cuffs without leakage (1.15) (p = 0.085). Preoperative FD of the infraspinatus of cuffs with recurrent tears (1.5) was significantly higher than that for cuffs without leakage (1.12) (p = 0.16). For the supraspinatus and the subscapularis, there was no significant difference between preoperative fatty degeneration of cuffs with recurrent tears and cuffs without leakage. The number of repaired tendons had a statistically significant effect (p = 0.012) on postoperative leakage: 23% of the recurrent tears after repair of three tendons showed no leakage compared with 9% after repair of one or two tendons (there was no significant difference for preoperative FDI, p = 0.33). Discussion: Resection of macroscopically abnormal tendon stumps which requires tendinomuscular plasty, gives better anatomic results than simple suture. For an equivalent FDI, this allows fewer cases of leakage (83% without leakage compared with 50% after simple suture). Results were also better for an equivalent number of tendons repaired: 77% and 50% for three tendons and 91% and 55% for two tendons respectively). Conclusion: Despite the almost constant need for plasty, rotator cuff repair using sutures without tension after resection of macroscopically abnormal tendon stumps gives, for an equivalent preoperative degree of fatty degeneration and an equivalent number of tendon repairs, better anatomic results than simple suture

Purpose. Chronic massive rotator cuff tears are challenging to repair completely because of the development of tendon retraction with inelasticity, muscle atrophy and fatty infiltration. The objective of this study was to investigate the clinical outcome and MRI findings after arthroscopic superior capsule reconstruction (ASCR) for symptomatic irreparable rotator cuff tears. Methods. From 2011 to 2013, 12 shoulders in 12 consecutive patients (mean, 70.8 years) with irreparable massive rotator cuff tears underwent ASCR using fascia lata. We used suture anchors to attach the graft medially to the glenoid superior tubercle and laterally to the greater tuberosity as same technique by Mihata et al. We added side-to-side sutures between the graft and infraspinatus tendon and between the graft and residual anterior supraspinatus/subscapularis tendon to improve force coupling. Physical examination, clinical rating system, and magnetic resonance imaging (MRI) were performed before surgery; at 6 and 12 months after surgery; and 6 months thereafter. Average follow-up was 19.1 months (12 to 28 months) after surgery. We assessed patients preoperatively by using the scoring systems of the shoulder index of the American Shoulder and Elbow Surgeons (ASES), the Japanese Orthopaedic Association, and the University of California, Los Angeles. Results. Mean active elevation increased from 59° to 111° significantly and external rotation increased from 28 to 33. The average preoperative scores were 16.0 points by ASES, 48.0 points by JOA, and 10.8 points by UCLA. Average clinical outcome scores all improved significantly after ASCR at the final follow-up (ASES, 73.3 points; JOA, 73.7 points; UCLA, 22.7 points). There was surgical complication as infection. Although infection was controlled by arthroscopic irrigation, the transplanted tendon was absorbed, and preoperative conditions did not functionally improve. Five patients had graft tear during follow-up. Postoperative active range of motion in the healed patients was significantly greater than in the unhealed patients who had graft tears. Conclusions. ASCR restored superior glenohumeral stability and function of the shoulder joint with irreparable rotator cuff tears compared to preoperative function in the cases without postoperative complications. However ratio of graft tears were 50% and clinical results of these cases were not improved sufficiently

Objectives

Indocyanine green (ICG) fluorescence angiography is an emerging technique that can provide detailed anatomical information during surgery. The purpose of this study is to determine whether ICG fluorescence angiography can be used to evaluate the blood flow of the rotator cuff tendon in the clinical setting.

Aims

Failure of healing is a well-known problem after repair of the rotator cuff. This study aimed to investigate if early repair of trauma-related full-thickness rotator cuff tears (FTRCTs) could prevent this failure.

Aims

Many biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots.

Aims

The purpose of this study was to compare the effectiveness of surgical repair to conservative treatment and subacromial decompression for the treatment of chronic/degenerative tears of the rotator cuff.

Aims

The aim of this study was to analyze the results of reverse shoulder arthroplasty (RSA) in patients with type 1 sequelae of a fracture of the proximal humerus in association with rotator cuff deficiency or severe stiffness of the shoulder.

Objectives

Platelet-rich fibrin matrix (PRFM) has been proved to enhance tenocyte proliferation but has mixed results when used during rotator cuff repair. The optimal PRFM preparation protocol should be determined before clinical application. To screen the best PRFM to each individual’s tenocytes effectively, small-diameter culture wells should be used to increase variables. The gelling effect of PRFM will occur when small-diameter culture wells are used. A co-culture device should be designed to avoid this effect.