Enhanced expression of neuronal proteins in idiopathic frozen shoulder

Transarterial Embolization for Adhesive Capsulitis of the Shoulder: Midterm Outcomes on Function and Pain Relief

PURPOSE

To determine the safety and potential effectiveness of transarterial embolization for adhesive capsulitis of the shoulder.

MATERIALS AND METHODS

This prospective study analyzed consecutive adult patients with adhesive capsulitis referred for embolization between January 2018 and May 2023 after a poor response to treatment (symptoms and limitation of motion in ≥2 axes; ≤120° flexion, ≤50° external rotation and/or internal rotation with the shoulder abducted 90°) persisting for >3 months after having completed ≥6 weeks of analgesics and physical therapy. Different types of pain and mobility were measured before embolization and 1, 3, and 6 months after embolization. Overall upper limb function (Quick Disabilities of Arm, Shoulder, and Hand) and patient satisfaction were measured before and 6 months after embolization. Long-term follow-up comprised telephone interviews and clinical history reviews.

RESULTS

A total of 20 patients (12 [60%] women; median age, 50.7; interquartile ranges [IQR], 45‒55 years) were included; 6 (30%) had diabetes and 15 (75%) were off work. Median duration of symptoms before embolization was 39.4 weeks (IQR, 28‒49 weeks), and median duration of rehabilitation therapy was 12.8 weeks (IQR, 8‒16 weeks). Six months after embolization, significant improvements were observed in nocturnal pain (P = .003), pain on moving (P = .001), external rotation (P < .001), internal rotation (P < .001), active flexion (P < .001), passive flexion (P = .03), active abduction (P < .001), passive abduction (P < .001), and overall function (P < .001). Despite objective improvements, patient satisfaction was nearly unchanged. Only 1 patient experienced a mild adverse event.

CONCLUSION

Transarterial embolization is safe and potentially effective in treating adhesive capsulitis of the shoulder refractory to conventional treatment. Clinical improvements were maintained in the mid to long term.

Frozen shoulder. An overview of pathology and biology with hopes to novel drug therapies

Frozen shoulder (FS) is a common disorder characterized by spontaneous onset of shoulder pain accompanied by progressive loss of range-of-motions. The cause of FS is still unclear, and radical therapy has not been established. With the final aim of preventing or curing FS at an earlier stage, we reviewed the pathological and biological features of this disease. Many studies indicate that the main pathology of FS is inflammation initially and fibrosis later. There are inflammatory cytokines, immune cells, fibrotic growth factors, and type-III collagen in the synovium and the joint capsule. The immune cell landscape switches from the macrophages to T cells. Activated fibroblasts seem to regulate the inflammatory and fibrotic processes. The imbalance between matrix metalloproteinases and tissue inhibitors of metalloproteases might promote fibrosis. Additionally, advanced glycation end-products are noted in the FS synovium. Diabetes mellitus and hypothyroidism are closely related to the development of FS. In terms of nonsurgical treatment, oral or intra-articular glucocorticoids are the only drugs that provide early benefit. Some other anti-inflammatory or antifibrotic drugs may potentially control the FS, but have not been proven effective in the clinical setting. Future studies should be targeted to develop steroid-sparing agents that inhibit biological events in FS.

What is the most predictive magnetic resonance imaging finding of rotator cuff tear concomitant with shoulder stiffness?

Background

Common magnetic resonance imaging (MRI) findings in adhesive capsulitis are not often evident in rotator cuff tear concomitant with shoulder stiffness. This study aimed to determine the most predictive MRI finding of rotator cuff tear with shoulder stiffness to differentiate from that without stiffness.

Materials and methods

The data of patients who underwent arthroscopic rotator cuff repair between January 2014 and October 2019 were retrospectively reviewed. Stiffness was defined as forward flexion <120°, external rotation at side <30°, and internal rotation at back 

Results

Anterior capsular thickness, glenoid capsular thickness in the axillary recess, and anterior and axillary capsular hyperintensities were significantly more dominant in the stiff group (all P < .05) than in the control group. Anterior capsular thickness and anterior capsular abnormal hyperintensity could be used to differentiate between the stiff and control groups (P < .05). Anterior capsular thickness showed high diagnostic performance with an area under the receiver operating characteristic curve of 0.993. The cut-off value for stiffness was 3.07 mm (sensitivity, 96.1%; specificity, 100%).

Conclusion

Anterior capsular thickening and abnormal hyperintensity were the most predictive MRI findings for stiffness in patients with rotator cuff tear and stiffness to differentiate from patients with rotator cuff tear without stiffness.

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Key Words

• Adhesive capsulitis
• Anterior capsular abnormal hyperintensity
• Anterior capsular thickness
• Magnetic resonance imaging
• Rotator cuff tear
• Stiff shoulder

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Affiliation(s)

Ji Young Yoon Department of Orthopaedic Surgery, National Police Hospital, Seoul, Republic of Korea
HeeSoo Han Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
Myoung Yeol Shin Department of Orthopaedic Surgery, National Police Hospital, Seoul, Republic of Korea
Hyeon Jang Jeong Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
Yusuhn Kang Department of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
Young Dae Jeon Department of Orthopaedic Surgery, Ulsan University College of Medicine, Ulsan University Hospital, Ulsan, Republic of Korea
Ji Un Kim Department of Orthopaedic Surgery, Korea University College of Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
Joo Han Oh Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea

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Efficacy of Intra-articular Triamcinolone and Hyaluronic Acid in a Frozen Shoulder Rat Model

BACKGROUND

Intra-articular corticosteroid or hyaluronic acid (HA) is commonly prescribed for frozen shoulder. However, few studies have investigated histological and molecular changes after injection.

PURPOSE

To compare the effectiveness of intra-articular injections of triamcinolone and HA in a frozen shoulder rat model and verify a greater effect of triamcinolone in passive shoulder abduction compared with HA.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty male Sprague-Dawley rats were randomly allocated into 4 groups (n = 5 in each): control group, which did not receive cast immobilization or injection, and 3 experimental groups, which received 3 weeks of unilateral shoulder immobilization followed by intra-articular injections (normal saline, triamcinolone, or HA) at the immobilized shoulder. Passive shoulder abduction angle, histological and immunohistochemical staining, and Western blotting results were assessed 2 weeks after injection. The intensity and extent of staining were converted to semiquantitative scores for further analysis.

RESULTS

Shoulder abduction angles before sacrifice were 153.0°± 2.7° (control group), 107.0°± 5.7° (saline group), 139.0°± 9.6° (triamcinoline group), and 110.0°± 10.6° (HA group), showing significant differences between control and saline groups, control and HA groups, saline and triamcinoline groups, and triamcinoline and HA groups (P < .001) but not between control and triamcinoline groups (P = .053). Histologic evaluation revealed an increase in synovial folds and thickening of the capsular membrane in the saline and HA groups; this change was not evident in the triamcinolone group. A comparison of semiquantitative scores revealed greater expression levels of proteins involved in fibrosis and angiogenesis in the saline and HA groups compared with the control and triamcinolone groups. In Western blotting, the expression of inflammatory cytokines and the receptor for advanced glycation end products was significantly lower in the triamcinolone and HA groups than in the saline group.

CONCLUSION

Triamcinolone injection was more effective than normal saline or HA injection in improving range of motion and reversing fibrotic and angiogenic features of frozen shoulder. Both triamcinolone and HA injections elicited anti-inflammatory effects.

CLINICAL RELEVANCE

The antifibrotic and antiangiogenic properties of triamcinolone and the anti-inflammatory properties of both triamcinolone and HA should be considered when performing injections in clinical settings.

Superior and Anterior Glenoid Labral Tears Are Associated With Increased Neurofilament Concentration

BACKGROUND

Pain is a common presentation after glenohumeral labral injuries. However, the source of that pain is undetermined.

PURPOSE/HYPOTHESIS

We aimed to determine if there is a differential expression of nerve fibers around the glenoid labrum and if torn labra have increased neuronal expression compared with untorn labra (rotator cuff repair labra). We hypothesized that the superior labrum would have a higher concentration of neurofilament than would the rest of the labrum and that the concentration of neurofilament would increase at the site of a labral tear.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Seven labra were sampled at the 3-, 5-, 9-, and 12-o'clock positions during total shoulder arthroplasty. Samples were also collected at the 3-, 5-, and 12-o'clock positions during rotator cuff repair (16 labra), anterior labral repair (6 labra), type II superior labral anterior to posterior (SLAP) repair (4 labra), and capsular release for idiopathic capsulitis (5 labra). Sections were immunostained with antibodies to neurofilament, a specific neuronal marker that is used to identify central and peripheral nerve fibers, and the concentration and intensity of immunostained-positive cells assessed.

RESULTS

The concentration of neurofilament staining was similar in the superior, anterior, posterior, and inferior glenoid labrum in untorn labra (8 neurofilament expressing cells per square millimeter; P = .3). Torn labra exhibited a 3- to 4-fold increase in neuronal expression, which was isolated to the location of the tear in SLAP (P = .09) and anterior labral tears (P = .02). The concentration of neurofilament expressing cells in torn glenoid labrum samples was comparable that in with the glenoid labrum of adhesive capsulitis samples (P = .7).

CONCLUSION

This study supports the hypothesis that after a tear of the anterior or superior labrum the labrum in that region becomes populated with new nerves fibers and that these fibers may be responsible for the pain noted by patients with superior (SLAP) and/or anterior labral (Bankart) tears.

CLINICAL RELEVANCE

This study suggests that neural infiltration contributes to the pain experienced by patients with labral tears. It may help with patient education and direct future management of labral lesions.

Tendon pain - what are the mechanisms behind it?

OBJECTIVES

Management of chronic tendon pain is difficult and controversial. This is due to poor knowledge of the underlying pathophysiology of chronic tendon pain, priorly known as tendinitis but now termed tendinopathy. The objective of this topical review was to synthesize evolving information of mechanisms in tendon pain, using a comprehensive search of the available literature on this topic.

CONTENT

This review found no correlations between tendon degeneration, collagen separation or neovascularization and chronic tendon pain. The synthesis demonstrated that chronic tendon pain, however, is characterized by excessive nerve sprouting with ingrowth in the tendon proper, which corresponds to alterations oberserved also in other connective tissues of chronic pain conditions. Healthy, painfree tendons are devoid of nerve fibers in the tendon proper, while innervation is confined to tendon surrounding structures, such as sheaths. Chronic painful tendons exhibit elevated amounts of pain neuromediators, such as glutamate and substance p as well as up-regulated expression and excitability of pain receptors, such as the glutamate receptor NMDAR1 and the SP receptor NK1, found on ingrown nerves and immune cells. Increasing evidence indicates that mast cells serve as an important link between the peripheral nervous system and the immune systems resulting in so called neurogenic inflammation.

SUMMARY

Chronic painful tendons exhibit (1) protracted ingrowth of sensory nerves (2) elevated pain mediator levels and (3) up-regulated expression and excitability of pain receptors, participating in (4) neuro-immune pathways involved in pain regulation. Current treatments that entail the highest scientific evidence to mitigate chronic tendon pain include eccentric exercises and extracorporeal shockwave, which both target peripheral neoinnervation aiming at nerve regeneration.

OUTLOOK

Potential mechanism-based pharmacological treatment approaches could be developed by blocking promotors of nerve ingrowth, such as NGF, and promoting inhibitors of nerve ingrowth, like semaphorins, as well as blocking glutamate-NMDA-receptor pathways, which are prominent in chronic tendon pain.

Transarterial Embolization of Neovascularity for Refractory Nighttime Shoulder Pain: A Multicenter, Open-Label, Feasibility Trial

PURPOSE

To assess the feasibility of transarterial embolization (TAE) for recalcitrant nighttime shoulder pain in a multicentric study.

MATERIALS AND METHODS

This prospective, open-label, feasibility trial included 100 patients treated at 5 institutions. TAE was performed in 76 patients with adhesive capsulitis (AC) and 24 patients with symptomatic rotator cuff tears (sRCTs). The ipsilateral radial artery was punctured, and imipenem/cilastatin sodium was infused as an embolic agent. Adverse events, 10 point pain numerical rating scale (NRS), range of motion (ROM) of the shoulder joint, and quality of life (via the EuroQol-5D [EQ-5D]) were evaluated.

RESULTS

All patients exhibited neovascularity on baseline angiography, and all TAE procedures were performed successfully. No patient experienced a major adverse event. The mean nighttime pain NRS scores at baseline and 1, 3, and 6 months after TAE were 6.4 ± 2.2, 3.4 ± 2.6, 2.3 ± 2.5, and 1.6 ± 2.2, respectively (for all, P < .001). The mean ROM of anterior elevation at baseline and 1, 3, and 6 months after TAE were 97° ± 29°, 119° ± 28°, 135° ± 27°, and 151° ± 17°, respectively (for all, P < .001). The mean EQ-5D scores at baseline and 1, 3, and 6 months after TAE were 0.63 ± 0.17, 0.73 ± 0.16, 0.80 ± 0.17, and 0.84 ± 0.17, respectively (for all, P < .001). There was no significant difference in the clinical success rate between the AC and sRCT groups.

CONCLUSIONS

TAE for nighttime shoulder pain caused by AC and sRCTs was feasible with sufficient safety and efficacy.

Alteration of chronic inflammatory status by transarterial embolization in frozen shoulder evaluated by 18-fluorine-fluoro-2-deoxyglucose positron-emission tomography/computed tomography

BACKGROUND

Frozen shoulder (FS) is speculated to have an inflammatory etiology. On angiography, abnormal angiogenesis is observed around the affected shoulder, suggesting a possible source of inflammation and pain. The effectiveness and safety of transarterial embolization (TAE) targeting abnormally proliferating blood vessels have been reported. This study investigated changes in chronic inflammatory and hypoxic status before and after TAE in FS by 19-fluorine-fluoro-2-deoxyglucose (FDG) positron-emission tomography/computed tomography as a possible mechanism of the therapeutic response to TAE.

METHODS

Fifteen patients with unilateral FS, persistent for more than 6 months, who were refractory to conservative treatments, underwent TAE using the temporary embolic agent imipenem/cilastatin. Patients underwent positron-emission tomography/computed tomography with FDG (as a biomarker of inflammation) before and 8 weeks after TAE. Regional uptake was evaluated by the maximum standardized uptake value. The lesion-side-to-(contralateral-) normal-side uptake ratio was also calculated. Pain and functional scales, range-of-motion, and laboratory tests, including white blood cell, C-reactive protein, interleukin 6, vascular endothelial growth factor, and tumor necrosis factor α were evaluated.

RESULTS

On FDG-PET, the average maximum standardized uptake value of the lesion-side was significantly greater than that of the normal-side (maximum standardized uptake value before TAE: 3.11 ± 1.25 vs 1.95 ± 1.15, P = .0001; 8-weeks post-TAE: 2.36 ± 0.74 vs 1.78 ± 0.69, P = .0002). The mean lesion-side-to-(contralateral-) normal-side uptake ratios before TAE (1.71 ± 0.60) decreased after TAE (1.37 ± 0.29, P = .011). The decrease of FDG uptake (-21.1 ± 12.2%) showed a significant correlation with the change in the pain scale score (r = -0.56, P = .039) and extension score (r = -0.59, P = .026).

CONCLUSION

Chronic inflammation in FS, as demonstrated by FDG uptake, was decreased after TAE. Thus, chronic inflammation is likely to be an underlying mechanism that should be targeted for symptomatic improvement of frozen shoulder.

Frozen shoulder

Frozen shoulder is a common debilitating disorder characterized by shoulder pain and progressive loss of shoulder movement. Frozen shoulder is frequently associated with other systemic conditions or occurs following periods of immobilization, and has a protracted clinical course, which can be frustrating for patients as well as health-care professionals. Frozen shoulder is characterized by fibroproliferative tissue fibrosis, whereby fibroblasts, producing predominantly type I and type III collagen, transform into myofibroblasts (a smooth muscle phenotype), which is accompanied by inflammation, neoangiogenesis and neoinnervation, resulting in shoulder capsular fibrotic contractures and the associated clinical stiffness. Diagnosis is heavily based on physical examination and can be difficult depending on the stage of disease or if concomitant shoulder pathology is present. Management consists of physiotherapy, therapeutic modalities such as steroid injections, anti-inflammatory medications, hydrodilation and surgical interventions; however, their effectiveness remains unclear. Facilitating translational science should aid in development of novel therapies to improve outcomes among individuals with this debilitating condition.

Characteristics of gene expression in frozen shoulder

Background

Severe frozen shoulder (FS) is often resistant to treatment and can thus result in long-term functional impairment. However, its etiology remains unknown. We hypothesized that gene expression of FS would vary by synovial location.

Methods

The synovial tissues of patients with FS were collected prospectively and analyzed for the expression of 19 genes. Synovial tissues from patients with rotator cuff tear (RCT) or shoulder instability (SI) were also analyzed as controls. A total of 10 samples were analyzed from each group. The specimens were arthroscopically taken from three different locations: rotator interval (RI), axillary recess (AX), and subacromial bursa (SAB). Total RNA was extracted from the collected tissues and was analyzed by real-time polymerase chain reaction for the following genes: matrix metalloproteinases (MMPs); tissue inhibitors of metalloproteinases (TIMPs); inflammatory cytokines (IL1B, TNF, and IL6); type I and II procollagen (COL1A1 and COL2A1); growth factors (IGF1 and TGFB1); neural factors (NGF and NGFR); SOX9; and ACTA2.

Results

Site-specific analysis showed that MMP13, IL-6, SOX9, and COL1A1 were increased in all three sites. Four genes (MMP3, MMP9, COL2A1, and NGFR) were increased in the AX, MMP3 in the RI, and NGFR in the SAB were increased in the FS group than in the RCT and SI groups. In the FS group, there was a correlation between the expression of genes related to chondrogenesis (MMP2, IGF1, SOX9, COL2A1, NGF, and NGFR) or fibrosis (MMP9, TGFB1, and COL1A1).

Conclusion

The expression levels of numerous MMPs, pro-inflammatory cytokines, and collagen-related genes were increased in the FS group, suggesting that catabolic and anabolic changes have simultaneously occurred. In addition, genes related to chondrogenesis or fibrosis were highly expressed in the FS group, which might have affected the range of motion limitation of the shoulder. Compared to RI and SAB, the AX was the most common site of increased expression in FS. Analyzing the lower region of the shoulder joint may lead to the elucidation of the pathogenesis of FS.

Postoperative Pain and Paresthesia in Labral Repairs of the Shoulder: Location Does Matter

Background:

Favorable outcomes have been reported regarding postoperative shoulder pain and function after repair of anteroinferior (Bankart) glenohumeral labral tears. However, the outcomes of patients after repair of isolated superior labral anterior-posterior (SLAP) tears are a contentious topic. The authors have also anecdotally noted that patients evaluated with labral tears complained of numbness and tingling in their ipsilateral hand.

Purpose:

To determine if there is a difference in the temporal outcomes of shoulder pain and hand paresthesia in patients with SLAP tears versus Bankart tears after arthroscopic repair.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included were 66 consecutive patients who underwent arthroscopic labral repair at a single institution between August 2018 and February 2021. The prevalence and magnitude of shoulder pain as well as numbness and tingling of the hand were assessed using questions from the L’Insalata Shoulder Questionnaire and the Boston Carpal Tunnel Questionnaire preoperatively and at 1 week, 6 weeks, 12 weeks, and 6 months after surgery.

Results:

Preoperatively, patients with SLAP lesions reported a higher prevalence of shoulder pain during sleep compared with those with Bankart tears (P < .05). Postoperatively, patients who underwent SLAP repair reported a larger proportion and more severe magnitude of shoulder pain during rest, overhead activities, and sleep compared with those who underwent Bankart repair (P < .05). Only patients who underwent Bankart repair reported improvements in the prevalence and magnitude of their shoulder pain during rest, overhead activities, and sleep by 6 months postoperatively compared with preoperative levels (P < .05). Preoperatively, 30% of patients with Bankart repairs and 40% of patients with SLAP repairs reported hand tingling, while 35% and 50%, respectively, reported hand numbness. The prevalence and magnitude of hand tingling and numbness were not significantly different between groups at any time point.

Conclusion:

Study results indicated that patients who underwent SLAP repair experienced worse shoulder pain outcomes compared with those who underwent Bankart repair using the same anchor and surgical technique. Only patients who underwent Bankart repair reported improvements in their hand numbness after surgery. Therefore, labral tear location does matter with respect to shoulder pain and hand numbness.

Pain, paraesthesia and the rotator cuff: the prevalence and magnitude of shoulder pain and hand numbness and tingling before and after rotator cuff repair

Background

Shoulder pain and loss of function are classically associated with rotator cuff tears, while paresthesia of the hand is not. We noted anecdotally that paresthesia of the arm was common in patients presenting with rotator cuff tears. The purpose of this study was to determine the prevalence and magnitude of hand paresthesia, its relationship to pain, and how surgery affected these symptoms.

Methods

This prospective cross-sectional study assessed the prevalence and magnitude of shoulder pain and hand numbness and tingling (as assessed by 2 questions from the modified Boston Carpal Tunnel Questionnaire) preoperatively and at 1 week, 6 weeks, 12 weeks, and 6 months postoperatively among 213 consecutive patients who presented for and underwent arthroscopic rotator cuff repair.

Results

The preoperative levels of prevalence and severity of shoulder pain during rest, overhead activities, and sleep improved by 52%, 22%, and 34%, respectively, compared with those by 6 months postoperatively (P < .05). Seventy-five patients (33%) reported hand paresthesia before surgery. There was a 50% and 60% reduction in the severity of hand tingling and numbness, respectively, by 1 week after surgery (P < .05). The preoperative level of hand numbness (Wald statistic; W = 20) and whether the patient’s shoulder problem was caused by a specific injury (W = 6) were predictive of the presence of hand numbness at 6 months after surgery (P < .05).

Conclusion

This study showed that many patients who undergo rotator cuff repairs present with hand paresthesia that is associated with their shoulder pain. The prevalence and severity of shoulder pain and hand numbness and tingling improved postoperatively.

Is there evidence to recommend transcatheter arterial embolisation in adhesive capsulitis: A review of literature

BACKGROUND

Hypervascularity of the rotator interval with increased expression of the vascular endothelial growth factor may be the causative factor of conventionally managed adhesive capsulitis. Hence, transcatheter arterial embolisation(TAE) has emerged as an alternative treatment option to occlude the target neovessels by infusing an embolic agent. The present study reviews the literature regarding the efficacy of the TAE for adhesive capsulitis.

MATERIAL AND METHODS

The systematic review was performed following PRISMA guidelines. MEDLINE, Google Scholar, Scopus and Cochrane database of systemic reviews (CDSR) were searched for relevant publication (from 1960 to 2021). The search algorithm used was Transcatheter arterial embolisation and resistant adhesive capsulitis or refractory adhesive capsulitis or vascular adhesive capsulitis. The database search produced a total of 12026 publications. After exclusion of the non relevant titles, 113 abstracts were reviewed. From these abstracts, three full-text articles were obtained for final review.

RESULTS

All the studies were analyzed in depth. Patients with no or minimal improvement with conservative treatment for at least 3 months underwent TAE. Pre and post embolisation visual analog score(VAS), shoulder range of motion(ROM) were noted. Any additional therapy was also taken into account. Significant improvement of the VAS score and shoulder ROM was noted immediately after surgery and maintained till final follow up at 24.5 months.

CONCLUSION

Resistant cases of adhesive capsulitis can be managed successfully with TAE. But ample evidence is lacking regarding the appropriate patient selection and efficacy of TAE as a sole management option of resistant AC.

Treatment of partial rotator cuff lesions is associated with a higher frequency of post-operative shoulder stiffness. A prospective investigation on the role of surgery-related risk factors for this complication

PURPOSE

Post-operative shoulder stiffness (SS) is a common complication after arthroscopic rotator cuff (RC) repair. The aim of this prospective study is to evaluate the role of surgical risk factors in the development of this complication, with special focus on the characteristics of the RC tears.

METHODS

Two-hundred and twenty patients who underwent arthroscopic RC repair for degenerative posterosuperior RC tears were included. Surgery-related risk factors for development of post-operative SS belonging to the following five categories were documented and analyzed: previous surgery, RC tear characteristics, hardware and repair type, concomitant procedures, time and duration of surgery. The incidence of post-operative SS was evaluated according to the criteria described by Brislin and colleagues.

RESULTS

The incidence of post-operative SS was 8.64%. The treatment of partial lesions by tear completion and repair technique was significantly associated with development of post-operative SS (p = 0.0083, pc = 0.04). A multivariate analysis revealed that treatment of partial lesions in patients younger than 60 years was associated to a higher risk of developing post-operative SS (p = 0.007). Previously known pre-operative risk factors such as female sex and younger age were confirmed. No other significant associations were documented.

CONCLUSION

The treatment of partial lesions of the RC may lead to a higher risk of post-operative SS than the treatment of complete lesions, in particular in patients younger than 60 years. Possible explanations of this finding are the increased release of pro-inflammatory cytokines caused by the additional surgical trauma needed to complete the lesion and the different pain perception of the subgroup of patients who require surgical treatment already for partial tears.

EVIDENCE

A higher risk of post-operative SS should be expected after tear completion and repair of partial lesions, especially in young patients. Appropriate pre-operative counseling and post-operative rehabilitation should be considered when approaching this subgroup of RC tears.

LEVEL OF EVIDENCE

Prognostic study, level II.

A Review of Musculoskeletal Embolization to Treat Pain Outside of the Knee

Chronic inflammation leading to musculoskeletal pain has garnered interest in the past decade with the success of genicular artery embolization for knee pain secondary to osteoarthritis. Outside the knee joint, musculoskeletal embolization has been applied to other anatomical locations, mainly shoulder pain secondary to adhesive capsulitis and elbow pain secondary to lateral epicondylitis. The success of these early trials and other case reports highlights the efficacy of musculoskeletal embolization and its future potential.

Results from a US Investigational Device Study of Adhesive Capsulitis Embolization (ACE) in the treatment of Shoulder Pain: The ACE Study

PURPOSE

To evaluate the safety and efficacy of arterial embolization to relieve shoulder pain secondary to Adhesive Capsulitis (AC).

METHODS AND MATERIALS

20 patients (18F, 2M: Mean age 51y) with AC resistant to > 30 days of conservative treatment were enrolled in a multi-center prospective study. Adhesive Capsulitis Embolization (ACE) was performed with 75 or 200 um spherical particles. Subjects were assessed before and after the procedure with MRI, VAS (0-100 mm), Single Assessment Numeric Evaluation (SANE, 0-100), and American Shoulder and Elbow Surgeons (ASES, 0-100) scores. Adverse Events (AEs) were recorded at all follow-up time points.

RESULTS

Hypervascularity was identified and embolization was technically successful in all patients with 83 arteries embolized in 20 patients. Baseline VAS, SANE, and ASES scores before the procedure were 89.2 mm, 27.2, and 30.9 mm, respectively. 1 (n=19), 3 (n=18), and 6 (n=12) months follow-up demonstrated significant improvements: 1 mo VAS (Δ Mean = -31.8, p = 1.2E-11), SANE (Δ Mean = 22.1, p = 1.8E-8), and ASES (Δ Mean = 14.2, p = 4.3E-5): 6 mon VAS (Δ Mean = -62.1, p = 7.0E-11) SANE (Δ Mean = 55.4, p = 4.1E-10), and ASES (Δ Mean = 44.5, p = 1.8E-6). Due to the coronavirus pandemic, the study was ended early and six patients did not complete the 6-month follow-up. No major adverse events were noted.

CONCLUSION

Interim findings suggest that arterial embolization is safe and effective for patients with AC refractory to conservative treatment.

Transcatheter Arterial Embolization Using Imipenem/Cilastatin Sodium for Chronic Low Back Pain Resistant to Conservative Treatment: A Pilot Study with 2-Year Follow-Up

PURPOSE

To evaluate the safety and 2-year follow-up clinical outcomes of transcatheter arterial embolization (TAE) using imipenem/cilastatin sodium for chronic low back pain resistant to conservative treatment.

MATERIALS AND METHODS

A retrospective review identified 14 patients who underwent TAE for chronic low back pain between October 2017 and August 2018. Patients with low back pain related to the facet or sacroiliac joint, lasting ≥ 6 months, refractory to ≥ 3 months of conservative treatment were eligible for TAE. Each patient received embolization of feeding arteries of painful regions. The changes in brief pain inventory (BPI) scores, adverse events, and the Oswestry Disability Index (ODI) were evaluated at baseline and 1, 3, and 24 months after TAE. Clinical success was defined as BPI maximum pain intensity decrease of ≥ 2 and ODI decrease of ≥ 10 points from baseline.

RESULTS

Follow-up data were available in 13 and 11 patients, at 3 and 24 months after embolization, respectively. Intention-to-treat clinical success was obtained in 11/14 (79%) of patients at 3 months and 8/14 (57%) of patients at 24 months after TAE. Mean BPI maximum pain intensity and ODI scores decreased significantly from baseline to 1, 3, and 24 months after treatment (7.6 vs.. 4.3, 3.4, and 4.1; 40.8 vs 21.5, 20.0, and 23.8, respectively; all P < 0.01). No major adverse events were associated with the procedures.

CONCLUSION

TAE is one possible treatment option for patients with chronic low back pain refractory to conservative treatment.

A Rat Model of Frozen Shoulder Demonstrating the Effect of Transcatheter Arterial Embolization on Angiography, Histopathology, and Physical Activity

PURPOSE

To assess the angiographic findings and the effects of transcatheter arterial embolization on physical activity and histopathology using a frozen shoulder rat model.

MATERIALS AND METHODS

First, the angiographic and histopathologic findings of rats in which the shoulder was immobilized with molding plaster for 6 weeks (n = 4) were compared to control rats with normal non-immobilized shoulders (n = 4). Next, a total of 16 frozen shoulder rats were divided into 2 groups. In the transcatheter arterial embolization group (n = 8), imipenem/cilastatin was injected into the left thoracoacromial artery. The changes of physical activity before and after procedures were evaluated and compared with a saline-injected control group (n = 8). Histopathologic findings were also compared between the 2 groups.

RESULTS

Angiography revealed abnormal shoulder staining in all of the rats with a frozen shoulder. On histopathology, the numbers of microvessels and mononuclear inflammatory cells in the synovial membrane of the joint capsule were significantly higher compared with the control rats (both P = .03). In the transcatheter arterial embolization group, the running distance and speed were improved (P = .03 and P = .01, respectively), whereas there were no significant differences in the control group. The number of microvessels and mononuclear inflammatory cells in the transcatheter arterial embolization group were significantly lower than the control group (P = .002 and P = .001, respectively).

CONCLUSIONS

The rat frozen shoulder model revealed the development of neovascularization. Transcatheter arterial embolization decreased the number of blood vessels and inflammatory changes in the frozen shoulder and increased the moving distance and speed of the rats.

Clinical Guidelines in the Management of Frozen Shoulder: An Update!

Among all the prevalent painful conditions of the shoulder, frozen shoulder remains one of the most debated and ill-understood conditions. It is a condition often associated with diabetes and thyroid dysfunction, and which should always be investigated in patients with a primary stiff shoulder. Though the duration of 'traditional clinicopathological staging' of frozen shoulder is not constant and varies with the intervention(s), the classification certainly helps the clinician in planning the treatment of frozen shoulder at various stages. Most patients respond very well to combination of conservative treatment resulting in gradual resolution of symptoms in 12-18 months. However, the most effective treatment in isolation is uncertain. Currently, resistant cases that do not respond to conservative treatment for 6-9 months could be offered surgical treatment as either arthroscopic capsular release or manipulation under anaesthesia. Though both invasive options are not clinically superior to another, but manipulation could result in unwarranted complications like fractures of humerus or rotator cuff tear.

Frozen Shoulder: A Systematic Review of Cellular, Molecular, and Metabolic Findings

BACKGROUND

Frozen shoulder is a common, poorly understood condition affecting the shoulder joint, with poor long-term outcomes in some in relation to pain and mobility. Understanding the pathophysiology of frozen shoulder at a cellular level and a molecular level may help in the development of novel treatments. The aim of this study was to perform a systematic review of studies examining the cellular, molecular, and metabolic findings in frozen shoulder.

METHODS

A literature search was conducted using Embase, CINAHL (Cumulative Index of Nursing and Allied Health Literature), and PubMed using relevant terms. Studies were included if they assessed cellular, molecular, or metabolic alterations in tissue or blood samples of patients with frozen shoulder.

RESULTS

Of 4,794 studies identified, 25 were included for analysis. Histological findings included nonspecific chronic inflammation and the proliferation of fibroblasts, adipocytes, and blood vessels. Molecular studies showed increased pro-inflammatory mediators, reduced matrix metalloproteinases (MMPs), and increased activity of factors promoting fibroblast activation and nerve growth. Metabolic alterations included an increase in blood lipids.

CONCLUSIONS

Frozen shoulder is thought to occur after a primary insult to the shoulder triggers a complex cascade and upregulation of growth factors and cytokines with an increased turnover of the extracellular matrix, activation of myofibroblasts with deposition of collagen, and reduced matrix degradation. The presence of a background pro-inflammatory state (e.g., patients with diabetes or hyperlipidemia) may exacerbate these abnormalities. Further work assessing patients in early stages of the disease and comparing the inflammatory or fibrogenic characteristics of the shoulder capsule with those of the other joints may help to determine the initiating factors and to explain the predisposition of the shoulder to stiffness.

CLINICAL RELEVANCE

Our findings may form the basis for identifying new targets for the clinical management of frozen shoulder.

Clinical Outcomes of Transcatheter Arterial Embolization for Secondary Stiff Shoulder

PURPOSE

To assess the clinical outcomes of transcatheter arterial embolization (TAE) for secondary stiff shoulder (SSS).

MATERIALS AND METHODS

This is a retrospective analysis of prospectively collected data performed between January 2017 and December 2019. This study comprised 25 patients (20 women and 5 men; median age, 49 years; range 27-59) with SSS resistant to conservative management during at least 3 months. The median time of stiffness was 12 months. The etiology of SSS was postoperative in 14 patients (56%) and posttraumatic in the remaining 11 patients (44%). Periods of immobilization in all patients were associated. TAE was performed, and technical aspects, adverse events, changes for pain, and physical examination before and 6 months after TAE were assessed.

RESULTS

Abnormal vessels were observed in 20 of 25 (80%) of the procedures. Transitory cutaneous erythema was noted in 4 patients treated after TAE. Significant differences were observed in the median pain visual analog scale reduction between before and 6 months after TAE (8 vs 2, P < .001). Shoulder mobility significantly improved in both flexion and abduction degrees between before and at 6 months after TAE in (70° vs 150°; P < .001). No symptoms of recurrence appeared.

CONCLUSIONS

TAE can result in pain reduction and mobility improvement in patients with SSS refractory to conservative therapy.

Results of repeat manipulation under ultrasound-guided cervical nerve root block with corticosteroid and local anaesthetic injection for recurrence of frozen shoulder

BACKGROUND

This study aimed to evaluate the clinical results of a repeat manipulation under ultrasound-guided cervical nerve root block (MUC) with corticosteroid and local anaesthetic injection for recurrence of idiopathic frozen shoulder after MUC.

METHODS

A consecutive series of 42 shoulders in 39 patients with idiopathic frozen shoulder underwent MUC. All patients were assessed according to the American Shoulder Elbow Surgeon (ASES) score and shoulder range of motion (ROM) both before MUC and at 1 year thereafter. If patients continued to have pain and limited ROM at 3 months after the procedure, they were offered a repeat MUC. Such patients were also assessed before the procedure and at 3 months and 1 year thereafter.

RESULTS

The initial MUC was successful in 31 shoulders (single group). Repeat MUC was required in 11 shoulders (repeat group). Patients in the single group showed significant improvement in ROM and ASES score at 1 year after the procedure (p < 0.001); similarly, patients in the repeat group had significant improvement in ROM and ASES score at 3 months and 1 year after the procedure (p < 0.001). Patients in the repeat group had had significantly more severely limited ROM (p < 0.01) and decreased ASES score (p < 0.001) before the procedure compared with those in the single group.

CONCLUSIONS

A repeat MUC with corticosteroid and local anaesthetic injection is a valuable option before proceeding to surgery for recurrence of idiopathic frozen shoulder. When there is severely limited ROM and decreased ASES score before the MUC, a repeat MUC may be necessary, which would require the patient's informed consent.

TRIAL REGISTRATION

Retrospectively registered.

The puzzling pathophysiology of frozen shoulders - a scoping review

Purpose

The pathophysiology of frozen shoulders is a complex and multifactorial process. The purpose of this review is to scope the currently available knowledge of the pathophysiology of frozen shoulders.

Methods

A systematic search was conducted in Medline, Embase and the Cochrane library. Original articles published between 1994 and October 2020 with a substantial focus on the pathophysiology of frozen shoulders were included.

Results

Out of 827 records, 48 original articles were included for the qualitative synthesis of this review. Glenohumeral capsular biopsies were reported in 30 studies. Fifteen studies investigated were classified as association studies. Three studies investigated the pathophysiology in an animal studies. A state of low grade inflammation, as is associated with diabetes, cardiovascular disease and thyroid disorders, predisposes for the development of frozen shoulder. An early immune response with elevated levels of alarmins and binding to the receptor of advance glycation end products is present at the start of the cascade. Inflammatory cytokines, of which transforming growth factor-β1 has a prominent role, together with mechanical stress stimulates Fibroblast proliferation and differentiation into myofibroblasts. This leads to an imbalance of extracellular matrix turnover resulting in a stiff and thickened glenohumeral capsule with abundance of type III collagen.

Conclusion

This scoping review outlines the complexity of the pathophysiology of frozen shoulder. A comprehensive overview with background information on pathophysiologic mechanisms is given. Leads are provided to progress with research for clinically important prognostic markers and in search for future interventions.

Level of evidence

Level V.

Mid-Term Results of Transcatheter Arterial Embolization for Adhesive Capsulitis Resistant to Conservative Treatment

PURPOSE

To evaluate the mid-term clinical outcomes of transcatheter arterial embolization (TAE) for adhesive capsulitis (AC) resistant to medical treatments.

MATERIALS AND METHODS

This is a prospective analysis performed between February 2016 and February 2020. Inclusion criteria for TAE were shoulder pain, restriction of movement and no response to conservative treatment for at least 3 months. Demographic variables, risk factors, technical aspects, adverse events, changes by visual analogue scale (VAS) for pain and physical examination before and after TAE were assessed.

RESULTS

This study included 40 patients with AC (35 women and 5 men; mean age 50 ± 9 years old). Abnormal vessels were observed in 31/40 (77.5%) procedures. As embolic agent, imipenem/cilastatin was used. The mean follow-up was 21.2 ± 10.5 months. Significant differences were obtained in terms of pain reduction before and 6 months after TAE with the median visual analogue scale (VAS) of 8 vs. 0.5, P = 0.0001. Substantial differences were found regarding mobility in flexion and abduction before and 6 months after embolization, respectively (79.5° ± 18.5° vs. 133° ± 24.5°, P = 0.0001; 72.4° ± 18.8° vs. 129.7° ± 27.9°, P = 0.0001). No complications occurred. Complete recovery was obtained in 37/40 (92.5%) patients and partial recovery in 2/40 (5%). No clinical recurrence appeared.

CONCLUSIONS

Clinical results of transcatheter arterial embolization with imipenem/cilastatin are effective and stable in the mid-term follow-up for patients presenting with AC resistant to conservative treatments.

Biomarkers associated with idiopathic frozen shoulder: a systematic review

Background: The pathophysiology of idiopathic frozen shoulder (FS) remains poorly described. There is a lack of differentiation between idiopathic and secondary cause. The aim of this systematic review was to summarize the evidence regarding the pathophysiology of idiopathic FS on a molecular level and emphasize the clinical relevance. Methods: A database search of Medline, EMBASE and Cochrane Central Register of Controlled Trials from inception to April 2018 was performed. Participants who underwent previous injections or surgeries were excluded. A thorough selection and quality assessment process using the Cochrane Risk of Bias assessment tool and the Joanna Briggs Institute Critical Appraisal Checklist was conducted by two reviewers independently. Results: A total of 15 studies analyzing 333 study subjects were included. Twelve studies evaluated capsular tissue and three studies investigated blood samples. The tissue samples revealed increased expression of various inflammatory cytokines including interleukins, cyclooxygenase and tumor necrosis factor. Several types of acid-sensing ion channels (ASIC1 and ASIC3) were associated with disturbed neurogenesis and melatonin-regulated pain mechanism. The blood samples showed prevalence of specific interleukin and metalloproteinase genotypes. A decreased matrix metalloproteinase/tissue inhibitor of metalloproteinase ratio was found both in tissue and blood. Conclusion: The findings indicate an abnormal local neurogenesis with possible regulation through melatonin. The disturbance in remodeling of the extracellular matrix and in collagen translation, together with a persistent inflammation and an impaired healing, all interact in the process that leads to persistent fibrosis. There is global fibroplasia with localized anterior capsule contracture.

Non-neoplastic Disease Outside the Spine-Genicular Artery Embolization and Adhesive Capsulitis Embolization

Initial research into the treatment of pain secondary to knee osteoarthritis and shoulder adhesive capsulitis with embolization have yielded promising results. With further investigation, embolization may become a mainstay of treatment for pain from these two conditions.

Ultrasound Microflow Imaging Technology for Diagnosis of Adhesive Capsulitis of the Shoulder

OBJECTIVES

To assess the diagnostic accuracy of Superb Microvascular Imaging (SMI; Canon Medical Systems, Otawara, Japan) at the subcoracoid triangle for adhesive capsulitis of the shoulder, to compare the diagnostic value of SMI with that of conventional ultrasound (US) and power Doppler ultrasound (PDUS) findings, and to investigate the correlation between vascular flow on SMI with clinical features.

METHODS

Our study included 39 patients with a diagnosis of adhesive capsulitis and 35 healthy patients as a control group. The echogenicity in the rotator interval and coracohumeral ligament thickness were assessed with conventional US. Vascular flow in the subcoracoid fat triangle was evaluated with SMI and PDUS (SMI and PDUS areas). A receiver operating characteristic curve analysis was performed to evaluate diagnostic accuracy. The correlation between US findings and the range of motion, pain intensity, and duration of symptoms was also evaluated.

RESULTS

The SMI area was higher in the adhesive capsulitis group than in the control group (2.95 versus 0 mm² ; P < .01). The visualization of vascular flow at the subcoracoid fat triangle was superior with SMI compared with PDUS (P < .01). In the receiver operating characteristic analysis, the SMI area showed higher diagnostic performance, with an area under the curve of 0.90 compared with other US findings. The area of SMI vascular flow was also negatively correlated with external rotation and forward flexion (P < .05) in the adhesive capsulitis group.

CONCLUSIONS

Measurement of vascular flow at the subcoracoid fat triangle using SMI facilitated the diagnosis of adhesive capsulitis. Superb Microvascular Imaging was superior to PDUS in diagnostic performance. Vascular flow was negatively correlated with the range of motion of external rotation and forward flexion.

Comparative proteome analysis of the capsule from patients with frozen shoulder

BACKGROUND

The etiology of frozen shoulder (FS) is unclear. Accordingly, this study used a label-free quantitative shotgun proteomic approach to elucidate the pathogenesis of FS based on protein expression levels.

METHODS

Tissue samples from the rotator interval (RI), middle glenohumeral ligament (MGHL), and anterior-inferior glenohumeral ligament (IGHL) were collected from 12 FSs with severe stiffness and 7 shoulders with a rotator cuff tear (RCT) as controls. Protein mixtures were digested and analyzed by nano-liquid chromatography/electrospray ionization-tandem mass spectrometry. Relative protein expression levels were calculated by the signal intensity of identified peptide ions on mass spectra. Differentially expressed proteins between FS and RCT samples were evaluated by a gene enrichment analysis using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes.

RESULTS

We identified 1594 proteins, 1358 of which were expressed in all 6 tissue groups. We detected more upregulated proteins in the upper (RI and MGHL) FS groups and the lower (IGHL) RCT group than in the comparative groups, respectively. Various proteins with functions in tissue repair, collagen metabolism and fibrillation, cell-cell and cell-matrix adhesion, blood coagulation, and the immune response were expressed more highly in the RI and MGHL FS groups than in the RCT group. Proteins with functions in phagocytosis, glutathione metabolism, retinoid metabolism, and cholesterol metabolism were expressed more highly in the IGHL RCT group than in the FS group.

CONCLUSIONS

The pathophysiology of FS differs between the upper and lower parts of the joint capsule. Different treatment strategies for FS may be appropriate, depending on the location.

Biological Aspect of Pathophysiology for Frozen Shoulder

It is fairly well understood that frozen shoulder involves several stages, which reflect the series of process from capsular inflammation and fibrosis to spontaneous resolution of this fibrosis. However, the underlying pathophysiologic process remains poorly determined. For this reason, management of frozen shoulder remains controversial. Determining the pathophysiological processes of frozen shoulder is a pivotal milestone in the development of novel treatment for patients with frozen shoulder. This article reviews what is known to date about the biological pathophysiology of frozen shoulder. Although articles for the pathophysiology of frozen shoulder provide inconsistent and inconclusive results, they have suggested both inflammation and fibrosis mediated by cytokines, growth factors, matrix metalloproteinases, and immune cells. Proinflammatory cytokines and growth factors released from immune cells control the action of fibroblast and matrix remodeling is regulated by the matrix metalloproteinases and their inhibitors. To improve our understanding of the disease continuum, better characterizing the biology of these processes at clearly defined stages will be needed. Further basic studies that use standardized protocols are required to more narrowly identify the role of cytokines, growth factors, matrix metalloproteinases, and immune cells. The results of these studies will provide needed clarity into the control mechanism of the pathogenesis of frozen shoulder and help identify new therapeutic targets for its treatment.

Alarmins in Frozen Shoulder: A Molecular Association Between Inflammation and Pain

BACKGROUND

The pathophysiological mechanisms behind proliferation of fibroblasts and deposition of dense collagen matrix in idiopathic frozen shoulder remain unclear. Alarmins (also known as danger signals) are endogenous molecules that are released into the extracellular milieu after infection or tissue injury and that signal cell and tissue damage.

PURPOSE

To investigate whether the presence of alarmins is higher in patients with idiopathic frozen shoulder than in control subjects.

STUDY DESIGN

Controlled laboratory study.

METHODS

Shoulder capsule samples were collected from 10 patients with idiopathic frozen shoulder and 10 patients with unstable shoulders (control). The samples were stained with hematoxylin and eosin (H&E) and analyzed by immunohistochemistry using antibodies against alarmin molecules including high-mobility group protein B1 (HMGB1), interleukin 33, S100A8, S100A9, and the peripheral nerve marker PGP9.5. Immunoreactivities were rated in a blinded fashion from "none" to "strong." Immunohistochemical distribution within the capsule was noted. Before surgery, patient-ranked pain frequency, severity, stiffness, and the range of passive shoulder motion were recorded and statistically analyzed.

RESULTS

Compared with control patients, patients with frozen shoulder had greater frequency and severity of self-reported pain ( P = .02) and more restricted range of motion in all planes ( P < .05). H&E-stained capsular tissue from frozen shoulder showed fibroblastic hypercellularity and increased subsynovial vascularity. Immunoreactivity of alarmins was significantly stronger in frozen shoulder capsules compared with control capsules ( P < .05). Furthermore, the expression of the alarmin molecule HMGB1 significantly correlated ( r > 0.9, P < .05) with the severity of patient-reported pain.

CONCLUSION

This study demonstrates a potential role for key molecular danger signals in frozen shoulder and suggests an association between the expression of danger molecules and the pain experienced by patients.

Adhesive capsulitis of the shoulder: review of pathophysiology and current clinical treatments

Adhesive shoulder capsulitis, or arthrofibrosis, describes a pathological process in which the body forms excessive scar tissue or adhesions across the glenohumeral joint, leading to pain, stiffness and dysfunction. It is a debilitating condition that can occur spontaneously (primary or idiopathic adhesive capsulitis) or following shoulder surgery or trauma (secondary adhesive capsulitis). Here, we review the pathophysiology of adhesive shoulder capsulitis, highlighting its clinical presentation, natural history, risk factors, pathoanatomy and pathogenesis. Both current non-operative and operative treatments for adhesive capsulitis are described, and evidence-based studies are presented in support for or against each corresponding treatment. Finally, the review also provides an update on the gene expression profile of adhesive capsulitis and how this new understanding can help facilitate development of novel pharmacological therapies.

Characteristics of dynamic magnetic resonance imaging of idiopathic severe frozen shoulder

BACKGROUND

The purpose of this study was to evaluate the effectiveness of current techniques for dynamic 3-dimensional magnetic resonance imaging (MRI) in the diagnosis of idiopathic severe frozen shoulder (FS).

MATERIALS AND METHODS

Subjects consisted of 5 healthy volunteers and 16 patients with idiopathic severe FS. We defined severe idiopathic FS as follows: range of motion ≤100° in forward flexion, ≤10° in external rotation, and ≤L5 in internal rotation. All patients suffered from continued global range of motion loss for at least 6 months. We evaluated the diagnostic characteristics of 3-dimensional dynamic MRI in FS patients compared with those in healthy volunteers.

RESULTS

MRI of all FS patients displayed an abnormal intake of blood flow from the acromial arterial network and the branches of circumflex humeral arteries into the axillary pouch and the rotator interval. We named this finding "burning sign." The burning sign was present at all phases of the condition. In the FS group, the patients with enhanced deposition of contrast medium in the axillary pouch in the delayed phase (n = 11) had a statistically significant score for pain during exercise, higher than that of patients with reduced deposition of contrast medium at the same site (n = 5; P = .027).

CONCLUSION

Burning sign is an abnormal finding that appears in dynamic MRI of severe FS. Hence, the burning sign may be associated with pain and inflammation in idiopathic FS.

Simultaneous acute shoulder arthritis and multiple mononeuropathy in a newly diagnosed type 2 diabetes patient - First case report

Diabetes is a common disorder that leads to the musculoskeletal symptoms such as the shoulder arthritis. The involvement of peripheral nervous system is one of the troublesome for the patients as it provokes chronic sensory symptoms, lower motor neuron involvement and autonomic symptoms. In the course of the disease there has been several types of neuropathies described. A 41-year-old male patient was admitted to the internal medicine department because of the general weakness, malaise, polydypsia and polyuria since several days. The initial blood glucose level was 780mg/dl. During the first day the continuous insulin infusion was administered. On the next day when he woke up, the severe pain in the right shoulder with limited movement, right upper extremity weakness and burning pain in the radial aspect of this extremity appeared. On examination right shoulder joint movement limitation was found with the muscle weakness and sensory symptoms in the upper limbs. The clinical picture indicated on the right shoulder arthritis and the peripheral nervous system symptoms such as the right musculocutaneous, supraspinatus, right radial nerve and left radial nerve damage. We present a first case report of simultaneous, acute involvement of the shoulder joint and multiple neuropathy in a patient with newly diagnosed type 2 diabetes, presumably in the state of ketoacidosis.

Short-term outcomes after arthroscopic capsular release for adhesive capsulitis

BACKGROUND

Little is known about the short-term temporal outcomes of an arthroscopic capsular release for adhesive capsulitis (frozen shoulder). Specifically, it is not known how immediate the improvements are and how quickly patients return to normal function after an arthroscopic release.

METHODS

The study included 140 shoulders in 133 patients with idiopathic adhesive capsulitis who underwent a complete arthroscopic release of the shoulder capsule, performed by a single surgeon in a day surgery setting. Patient-reported pain and shoulder function were evaluated with the use of Likert scales, and an independent examiner assessed shoulder strength and range of motion preoperatively and at 1 week, 6 weeks, 12 weeks, and 24 weeks postoperatively.

RESULTS

Arthroscopic capsular release resulted in immediate improvements in pain, functional outcomes, and range of motion (P < .0001). External rotation increased from 21° ± 17° (mean ±  standard deviation) to 76° ± 17° at 1 week. Passive range of shoulder motion improved at 1 week, deteriorated slightly at 6 weeks, and then continued to improve at 12 and 24 weeks. Before surgery, 38% of patients reported that they "always" experienced extreme pain. This proportion reduced to 30% (P < .0001) at 1 week postoperatively and 2% (P < .0001) at 24 weeks postoperatively. There were no complications.

CONCLUSIONS

Patients who underwent an arthroscopic capsular release for idiopathic adhesive capsulitis experienced significant reductions in pain, improvements in range of motion, and improvements in overall shoulder function in the first postoperative week. These immediate improvements in pain and function continue to improve at 6, 12, and 24 weeks postoperatively.

The pathophysiology associated with primary (idiopathic) frozen shoulder: A systematic review

Background

Frozen shoulder is a common yet poorly understood musculoskeletal condition, which for many, is associated with substantial and protracted morbidity. Understanding the pathology associated with this condition may help to improve management. To date this has not been presented in a systematic fashion. As such, the aim of this review was to summarise the pathological changes associated with this primary frozen shoulder.

Methods

Databases: Medline, Embase, CINAHL, AMED, BNI and the Cochrane Library, were searched from inception to 2nd May, 2014. To be included participants must not have undergone any prior intervention. Two reviewers independently conducted the; searches, screening, data extraction and assessment of Risk of Bias using the Cochrane Risk of Bias Assessment Tool for non-Randomised Studies of Interventions (ACROBAT-NRSI). Only English language publications reporting findings in humans were included. The findings were summarised in narrative format.

Results

Thirteen observational studies (involving 417 shoulders) were included in the review. Eight studies reported magnetic resonance imaging or arthrography findings and 5 recorded histological findings. When reported mean ages of the participants ranged from 40.0 to 59.8 years. Duration of symptoms ranged from 0 to 30 months. The majority of studies (n = 7) were assessed to be of moderate risk of bias, two studies at high risk and the remaining four were rated as low risk of bias. Study characteristics were poorly reported and there was widespread variety observed between studies in respect of data collection methods and inclusion criteria employed. Pathological changes in the anterior shoulder joint capsule and related structures were commonly reported. Imaging identified pathological changes occurring in the coracohumeral ligament, axillary fold and rotator interval. Obliteration of the subcoracoid fat triangle also appeared to be pathognomonic. Histological studies were inconclusive but suggested that immune, inflammatory and fibrotic changes where associated with primary frozen shoulder.

Conclusions

This systematic review presents a summary of what is currently known about the tissue pathophysiology of primary frozen shoulder. Further studies that use standardised inclusion and exclusion criteria and investigate changes in naïve tissue at different stages of the condition are required.

The roles of Tenascin C and Fibronectin 1 in adhesive capsulitis: a pilot gene expression study

OBJECTIVES

We evaluated mRNA expression levels of genes that encode TGF-β1; the TGF-β1 receptor; the collagen-modifying enzymes LOX, PLOD1, and PLOD2; and the extracellular matrix proteins COMP, FN1, TNC and TNXB in synovial/capsule specimens from patients with idiopathic adhesive capsulitis. Possible associations between the measured mRNA levels and clinical parameters were also investigated.

METHODS

We obtained glenohumeral joint synovium/capsule specimens from 9 patients with idiopathic adhesive capsulitis who had not shown improvement in symptoms after 5 months of physiotherapy. Adhesive capsulitis was confirmed in all patients by magnetic resonance imaging. We also obtained specimens from 8 control patients who had underwent surgery for acute acromioclavicular joint dislocation and who had radiological indication of glenohumeral capsule alteration based on arthroscopic evaluation. mRNA expression in the synovium/capsule specimens was analyzed by quantitative reverse transcription PCR. The B2M and HPRT1 genes were used as references to normalize target gene expression in the shoulder tissue samples.

RESULTS

The synovium/capsule samples from the patients with adhesive capsulitis had significantly higher TNC and FN1 expression than those from the controls. Additionally, symptom duration directly correlated with expression of TGFβ1 receptor I.

CONCLUSION

Elevated levels of TNC and FN1 expression may be a marker of capsule injury. Upregulation of TGFβ1 receptor I seems to be dependent on symptom duration; therefore, TGFβ signaling may be involved in adhesive capsulitis. As such, TNC, FN1 and TGFβ1 receptor I may also play roles in adhesive capsulitis by contributing to capsule inflammation and fibrosis.

Advanced glycation end products in idiopathic frozen shoulders

BACKGROUND

The pathophysiologic mechanisms behind proliferation of fibroblasts and deposition of dense collagen matrix in idiopathic frozen shoulder remain unclear. Accumulation of advanced glycation end products (AGEs) with cross-linking and stabilization of collagen has been hypothesized to contribute to this pathophysiologic process. This study investigated whether the immunoreactivity of AGEs is higher in patients with idiopathic frozen shoulder than in the control groups.

METHODS

Shoulder capsule samples were collected from 8 patients with idiopathic frozen shoulder, 6 with unstable shoulders (control 1), and 8 with rotator cuff tears (control 2). The samples were hematoxylin and eosin stained and analyzed by immunohistochemistry using antibodies against AGEs. Immunoreactivities were rated in a blinded fashion from none (0) to strong (3). Immunohistochemical distribution within the capsule was noted.

RESULTS

Frozen shoulder patients had greater frequency and severity of self-reported pain (P = .02) than rotator cuff tear patients and more restricted range of motion in all planes (P < .05) than patients of the instability and rotator cuff tear groups. Hematoxylin and eosin-stained capsular tissue from frozen shoulder showed fibroblastic proliferation, increased numbers of adipocytes, and increased subsynovial vascularity. Immunoreactivity of AGEs was stronger in frozen shoulder capsules (2.8) than in instability (0.3; P = .0001) and rotator cuff tear (1.1; P = .016) capsules.

CONCLUSION

This study highlights a potential role for AGEs in the pathogenesis of frozen shoulder. The overexpression of AGEs may explain the fibroblastic proliferation and deposition of collagen matrix in idiopathic frozen shoulder.

LEVEL OF EVIDENCE

Basic Science Study; Histology.

Are the Symptoms of Calcific Tendinitis Due to Neoinnervation and/or Neovascularization?

BACKGROUND

Calcific tendinitis can be a substantial cause of pain and dysfunction in the shoulder, and the pathophysiology is unclear. Recent studies have shown a link among nerve ingrowth, neovascularization, and pain in tendinopathy. The aim of this study was to determine whether there is evidence of neoinnervation and/or neovascularization in calcific tendinitis lesions of the shoulder.

METHODS

At arthroscopy, ultrasound was used to identify calcium within the tendon. Samples were taken from the supraspinatus tendon adjacent to the calcific lesion (in the calcific tendinitis group, with ten patients), the torn supraspinatus tendon of patients undergoing rotator cuff repair (the rotator cuff tear group, with ten patients), and the subscapularis tendon of patients undergoing a stabilization surgical procedure (the control group, with ten patients). Biopsied tendon samples were evaluated immunohistochemically by quantifying the presence of macrophages (using CD68 and CD206), T cells (CD3), mast cells (mast cell tryptase), vascular endothelium (CD34), and peripheral nerve markers (PGP 9.5).

RESULTS

There was a twofold to eightfold increase of nerve markers, neovascularization, macrophages, M2 macrophages, and mast cells in the calcific tendinitis group compared with the rotator cuff tear group (p < 0.001) and the control group (p < 0.001). Increased nerve counts positively correlated with more frequent extreme pain (r = 0.5, p < 0.01) and with increased neovascularization (r = 0.7, p < 0.01) and counts of CD68 macrophages (r = 0.8, p < 0.01), M2 macrophages (r = 0.6, p < 0.01), and mast cells (r = 0.7, p < 0.01).

CONCLUSIONS

This is the first study to show a significant increase in neovascularization and neoinnervation in calcific tendinitis lesions of the shoulder along with an eightfold increase in mast cells and macrophages. The findings are consistent with the hypothesis that, in calcific tendinitis, the calcific material is inducing a vigorous inflammatory response within the tendon with formation of new blood vessels and nerves.

CLINICAL RELEVANCE

This study helps to explain why calcific tendinitis is related to substantial pain in the clinical setting.

Generation and characterization of a novel shoulder contracture mouse model

Frozen shoulder is a relatively common disorder that leads to severe pain and stiffness in the shoulder joint. Although this disorder is self-limiting in nature, the symptoms often persist for years, resulting in severe disability. Recent studies using human specimens and animal models have shown distinct changes in the gene expression patterns in frozen shoulder tissue, indicating that novel therapeutic intervention could be achieved by controlling the genes that are potentially involved in the development of frozen shoulder. To achieve this goal, it is imperative to develop a reliable animal joint contracture model in which gene expression can be manipulated by gene targeting and transgenic technologies. Here, we describe a novel shoulder contracture mouse model. We found that this model mimics the clinical presentation of human frozen shoulder and recapitulates the changes in the gene expression pattern and the histology of frozen shoulder and joint contracture in humans and other larger animal models. The model is highly reproducible, without any major complications. Therefore, the present model may serve as a useful tool for investigating frozen shoulder etiology and for identifying its potential target genes.

Short-term results of transcatheter arterial embolization for abnormal neovessels in patients with adhesive capsulitis: a pilot study

BACKGROUND

Neovessels and accompanying nerves are possible sources of pain. We postulated that transcatheter arterial embolization of abnormal neovessels would relieve pain and symptoms in patients with adhesive capsulitis.

METHODS

Adhesive capsulitis was treated by transcatheter arterial embolization in 7 patients. Adverse events, changes in visual analog scale scores for night pain and overall shoulder pain, and changes in range of motion and American Shoulder and Elbow Surgeons scores were assessed at 1 week and at 1, 3, and 6 months after the procedure.

RESULTS

Abnormal neovessels were identified at the rotator interval in all patients. No major or minor adverse events were associated with the procedures. Transcatheter arterial embolization rapidly decreased nighttime pain scores from 67 ± 14 mm to 27 ± 14 mm at 1 week after the procedure, with further improvement at 1 and 6 months (6 ± 8 mm and 2 ± 5 mm, respectively). The American Shoulder and Elbow Surgeons score significantly improved from 17.8 ± 4.5 to 39.8 ± 12.0, 64.3 ± 13.9, and 76.2 ± 4.4 at 1, 3, and 6 months, respectively.

CONCLUSION

All patients with adhesive capsulitis had abnormal neovessels at the rotator interval. Transcatheter arterial embolization was feasible, relieved unrelenting pain, and restored shoulder function.

Primary frozen shoulder: brief review of pathology and imaging abnormalities

BACKGROUND

Primary frozen shoulder (FS) is a painful contracture of the glenohumeral joint that arises spontaneously without an obvious preceding event. Investigation of the intra-articular and periarticular pathology would contribute to the treatment of primary FS.

REVIEW OF LITERATURE

Many studies indicate that the main pathology is an inflammatory contracture of the shoulder joint capsule. This is associated with an increased amount of collagen, fibrotic growth factors such as transforming growth factor-beta, and inflammatory cytokines such as tumor necrosis factor-alpha and interleukins. Immune system cells such as B-lymphocytes, T-lymphocytes and macrophages are also noted. Active fibroblastic proliferation similar to that of Dupuytren's contracture is documented. Presence of inflammation in the FS synovium is supported by the synovial enhancement with dynamic magnetic resonance study in the clinical setting.

CONCLUSION

Primary FS shows fibrosis of the joint capsule, associated with preceding synovitis. The initiator of synovitis, however, still remains unclear. Future studies should be directed to give light to the pathogenesis of inflammation to better treat or prevent primary FS.