Intra-articular Pressure Profiles of Painful Stiff Shoulders Compared With Those of Other Conditions

Effect of intraarticular pressure on glenohumeral kinematics during a simulated abduction motion: a cadaveric study

BACKGROUND

The current understanding of glenohumeral joint stability is defined by active restrictions and passive stabilizers including naturally-occurring negative intraarticular pressure. Cadaveric specimens have been used to evaluate the role of intraarticular pressure on joint stability, although, while the shoulder's negative intraarticular pressure is universally acknowledged, it has been inconsistently accounted for.

HYPOTHESIS

During continuous, passive humeral abduction, releasing the native intraarticular pressure increases joint translation, and restoring this pressure decreases joint translations.

STUDY DESIGN

Descriptive Laboratory Study.

METHODS

A validated shoulder testing system was used to passively abduct the humerus in the scapular plane and measure joint translations for seven (n = 7) cadaveric specimens. The pressure within the glenohumeral joint was measured via a 25-gauge needle during passive abduction of the arm, which was released and subsequently restored. During motion, the rotator cuff muscles were loaded using stepper motors in a force feedback loop and electromagnetic sensors were used to continuously measure the position of the humerus and scapula. Joint translation was defined according to the instant center of rotation of the glenohumeral head according to the recommendations by the International Society of Biomechanics.

RESULTS

Area under the translation versus abduction angle curve suggests that releasing the pressure within the capsule results in significantly less posterior translation of the glenohumeral head as compared to intact (85-90˚, p < 0.05). Posterior and superior translations were reduced after 70˚ of abduction when the pressure within the joint was restored.

CONCLUSION

With our testing system employing a smooth continuous passive motion, we were able to show that releasing intraarticular pressure does not have a major effect on the path of humeral head motion during glenohumeral abduction. However, both violating the capsule and restoring intraarticular pressure after releasing alter glenohumeral translations. Future studies should study the effect of simultaneous external rotation and abduction on the relationship between joint motion and IAP, especially in higher degrees of abduction.

CLINICAL RELEVANCE

Thoroughly simulating the glenohumeral joint environment in the cadaveric setting may strengthen the conclusions that can be translated from this setting to the clinic.

Intra-articular pressure characteristics of the knee joint: An exploratory study

Inflammation-predominant osteoarthritis is an important clinical type of osteoarthritis, with synovitis suggested as its distinct pathophysiology. We investigated whether the synovium's mechanical properties in knees differed by osteoarthritis and other clinical parameters through retrospectively analyzing intra-articular pressure-volume characteristics. We analyzed 60 knees that were administered intra-articular corticosteroids while undergoing pressure monitoring. McMurray's test, pain complaints at end-range knee flexion, Kellgren-Lawrence classification from standing anteroposterior radiographs, and suprapatellar effusion from ultrasound constituted clinical parameters. Pressure-volume profiles-phasic changes in pressure by volume infusion, the volume of Phase 1-the potential volume of the synovial space, the pressure at 45 ml infusion-intra-articular pressure at a standardized volume, and the slope of Phase 2-synovial stiffness were compared with clinical parameters. All graphs were biphasic. Knees with suprapatellar effusion or radiologically definite osteoarthritis (Kellgren-Lawrence grade ≥2), had a lower Phase 1 volume. Knees with definite radiographic osteoarthritis also showed higher pressures at 45 ml and Phase 2 slopes (171.11 ± 94.35 mmHg and 5.08 ± 3.07 mmHg/ml, respectively) than those without (101.88 ± 58.12 mmHg and 2.84 ± 1.27 mmHg/ml, respectively). The Phase 2 slope was higher for knees with positive provocative tests than in those with negative provocative tests, although not statistically significant. The synovium stretched earlier in knees with effusion or radiologically definite osteoarthritis. Intra-articular pressure and synovial stiffness were significantly higher in patients with radiologically definite osteoarthritis. The synovium's mechanical characteristics are altered by osteoarthritis of the knee joint. Intra-articular pressure characteristics could be utilized for synovial evaluation clinically.

Effects of Hydrodilatation With Corticosteroid Injection and Biomechanical Properties in Patients With Adhesive Capsulitis After Breast Cancer Surgery

Objective

To compare the biomechanical properties of the glenohumeral joint capsule between adhesive capsulitis (AC) after breast cancer surgery and idiopathic AC and demonstrate the effects of hydrodilatation (HD) with corticosteroid injection for AC after breast cancer surgery.

Methods

Twenty-three prospective patients with AC after breast cancer surgery (BC group) and 44 retrospective patients with idiopathic AC without breast cancer (CON group) underwent HD with corticosteroid injection and home exercise training. We compared their biomechanical characteristics (capsular capacity, maximal pressure, and capsular stiffness). In the BC group, the passive range of motion (ROM) of the affected shoulder and a questionnaire (Shoulder Pain and Disability Index [SPADI]) were evaluated at baseline and 2 and 4 weeks after treatment.

Results

The BC group showed higher biomechanical characteristics (maximal pressure and capsular stiffness) than did the CON group. The mean maximal pressure and capsular stiffness were 519.67±120.90 mmHg and 19.69±10.58 mmHg/mL in the BC group and 424.78±104.42 mmHg and 11.55±7.77 mmHg/mL in the CON group (p=0.002 and p=0.001, respectively). And, the BC group showed significant improvements in all ROMs (abduction, flexion, and external rotation) and the SPADI pain and disability sub-scores following the treatment.

Conclusion

The glenohumeral joint capsular stiffness was greater in the patients with AC after breast cancer surgery than in those with idiopathic AC. HD with corticosteroid injection was effective in treating AC after breast cancer surgery.

Updates on the treatment of adhesive capsulitis with hydraulic distension

Adhesive capsulitis of the shoulder joint is a common disease characterized by pain at the insertional area of the deltoid muscle and decreased range of motion. The pathophysiological process involves fibrous inflammation of the capsule and intraarticular adhesion of synovial folds leading to capsular thickening and contracture. Regarding the multidirectional limitation of motion, a limitation in external rotation is especially prominent, which is related to not only global fibrosis but also to a localized tightness of the anterior capsule. Ultrasound and magnetic resonance imaging studies can be applied to rule out other structural lesions in the diagnosis of adhesive capsulitis. Hydraulic distension of the shoulder joint capsule provides pain relief and an immediate improvement in range of motion by directly expanding the capsule along with the infusion of steroids. However, the optimal technique for hydraulic distension is still a matter of controversy, with regards to the infusion volume and rupture of the capsule. By monitoring the real-time pressure-volume profile during hydraulic distension, the largest possible fluid volume can be infused without rupturing the capsule. The improvement in clinical outcomes is shown to be greater in capsule-preserved hydraulic distension than in capsule-ruptured distension. Moreover, repeated distension is possible, which provides additional clinical improvement. Capsule-preserved hydraulic distension with maximal volume is suggested to be an efficacious treatment option for persistent adhesive capsulitis.

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.

Atypical calcific tendinitis involving the long biceps tendon: A rare cause of hemiplegic shoulder pain

BACKGROUND AND OBJECTIVE

Calcific tendinitis is commonly found in the rotator cuff; however, it is very rare in the long biceps tendon (LBT). Furthermore, calcific tendinitis involving the LBT in the hemiplegic shoulder after a stroke has not been previously reported.

MATERIALS AND METHOD

We present a case of a 63-year-old man who suffers from a stroke and atypical calcific tendinitis involving the LBT as a rare cause of hemiplegic shoulder pain. The patient had experienced intractable pain in the right hemiplegic shoulder for more than 6 months with a waxing and waning course. Marked tenderness to palpation was present at the biceps tendon adjacent to the bicipital groove. Ultrasound (US) and computed tomography revealed a long, blade-shaped, circumscribed, cloudy and irregular dense calcific deposit in the LBT site, distal to the bicipital groove. The patient underwent US-guided corticosteroid injection at the posterior intra-articular joint. The symptoms failed to resolve; we injected an additional corticosteroid into the biceps tendon sheath adjacent to the calcific deposit. This procedure provided satisfactory relief, and follow-up US revealed mild diminution of the calcification through absorption.

CONCLUSION

This is the first report on atypical calcific tendinitis involving the LBT causing hemiplegic shoulder pain after a stroke.

Effectiveness of Glenohumeral Joint Dilatation for Treatment of Frozen Shoulder: A Systematic Review and Meta-analysis of Randomized Controlled Trials

The objective was to explore the effectiveness of glenohumeral joint distension for the treatment of frozen shoulder. We searched electronic data sources including PubMed, Scopus, and Embase from the earliest records available to February 2017. Eleven randomized controlled trials including at least one pair of comparisons between capsular distension and a reference treatment were included, comprising 747 participants. Patients’ characteristics, details of reference treatments, aspects of capsular distension therapy, and outcome measurement were evaluated at three points in time: baseline, early following intervention, and at the trial’s end. The primary and secondary outcomes were the between-group standardized mean differences of changes in shoulder function and range of motion, respectively. Regarding the long-term primary outcome, the superiority of capsular distension to reference treatments was not identified. One secondary outcome (external rotation limitation) showed a probable early positive response to capsular distension when compared to intra-articular corticosteroid injection. Aspects of approaches, imaging guiding techniques and doses of distension were not found to modify treatment effectiveness. In conclusion, distension of the glenohumeral joint provides a similar long-term efficacy to all reference treatments. A single dose of a corticosteroid-contained regimen introduced through the ultrasound-guided posterior approach is a preferable practice of capsular distension for the management of frozen shoulder.

Correlation of Joint Volume and Passive Range of Motion With Capsulo-Synovial Thickness Measured by Contrast-Enhanced Magnetic Resonance Imaging in Adhesive Capsulitis

BACKGROUND

No study has investigated the relationship between the findings of contrast-enhanced magnetic resonance imaging (CE-MRI) and the joint volume of the shoulder, which has been considered the standard reference for diagnosis of adhesive capsulitis (AC).

OBJECTIVE

To investigate the relationships among the capsulo-synovial thickness measured by CE-MRI, joint volume, and passive range of motion (ROM) in patients with AC.

DESIGN

This was a retrospective study.

SETTING

The study took place at an institutional practice.

PATIENTS

Medical record of 103 patients (46 male and 57 female), who were treated with sonographically guided intra-articular injection with diagnosis of AC and underwent CE-MRI to rule out other concomitant shoulder disease, were retrospectively reviewed.

METHODS

Passive ROM and glenohumeral joint (GHJ) volume were measured before and during sonographically guided injection. The thickness of the enhancing portion of the capsulo-synovium was measured at the axillary recess and rotator interval on CE-MRI.

MAIN OUTCOME MEASUREMENTS

The relationship among the thickness of the enhancing portion on CE-MRI, GHJ volume, and passive ROM was analyzed using the Pearson correlation coefficient.

RESULTS

Capsulo-synovial thickness measured by CE-MRI at the enhancing portion of the axillary recess inversely correlated with GHJ volume (ρ = -0.444, P < .001), whereas at the rotator interval, this finding was not observed. At the axillary recess, the capsulo-synovial thickness inversely correlated with abduction (ρ = -0.400, P < .001), forward elevation (ρ = -0.378, P < .001), and external rotation (ρ = -0.297, P < .01), but at the rotator interval, such statistically significant correlations were not shown.

CONCLUSION

The capsulo-synovial thickness measured by CE-MRI at the enhancing portion of the axillary recess could represent obliterated joint capacity and clinical impairment (restricted passive ROM), which could help in diagnosing AC and in differentiating other shoulder diseases that may mimic this condition.

LEVEL OF EVIDENCE

III.

Subperiosteal transmission of intra-articular pressure between articulated and stationary joints

Hydrostatic pressures can be transmitted between synovial capsules. In each of ten rabbits, we simultaneously measured pressure in two joints, one of which was passively ranged, and the other of which was kept stationary. The intra-articular pressure inside the stationary joint changed every time its companion joint was ranged. But the pressure in the stationary joint did not change when the periosteum was transected above the ranged joint. This phenomenon was observed in all four animals that served as their own controls. The study suggests that the intra-articular pressure was transmitted through the space between the periosteum and the bone surface. Alternative explanations, like measurements of venous blood pressure, did not show correlation with hydrostatic pressure changes in the joints. The Floating Skeleton concept suggests a biomechanical rationale for this newly observed phenomenon: that there exists a subperiosteal hydrostatic connection of synovial joints, and that this "net" distributes excess pressures among joints through the periosteal sheath to sustain the integrity of the joint contacting surfaces over a lifetime.

Biomechanical properties of the glenohumeral joint capsule in hemiplegic shoulder pain

BACKGROUND

Although many hemiplegic shoulder patients have been suffering from limited range of motion, it is not fully established whether the pathologic biomechanics are same in hemiplegic shoulder pain and adhesive capsulitis. Therefore we aimed to investigate biomechanical properties of glenohumeral joint capsules of hemiplegic shoulder pain with limited range of motions.

METHODS

Participants were 14 patients with hemiplegic shoulder pain, 10 controls, and 42 adhesive capsulitis patients matched with the hemiplegic shoulder pain group for sex, age, and range of motion. Demographic data, clinical variables, and sonographic findings were comparable between hemiplegic shoulder pain and adhesive capsulitis groups. We compared capsular capacity, maximal pressure, and capsular stiffness of glenohumeral joint capsule among the 3 groups.

FINDINGS

Hemiplegic shoulder pain and adhesive capsulitis groups had smaller capsular capacity and higher maximal pressure than controls. The capsular stiffness of hemiplegic shoulder pain group was higher than that of controls (P=0.001) but lower than that of adhesive capsulitis group (P<0.001).

INTERPRETATION

The stiffness of glenohumeral joint capsules in hemiplegic shoulder pain and adhesive capsulitis patients was substantially higher than that in controls, suggesting that hemiplegic shoulder pain patients had stiffer capsules as adhesive capsulitis patients did although the severities were different. This finding implicates that hemiplegic shoulder pain may share common pathologic properties of tighter capsules with adhesive capsulitis. However, there may be additional mechanisms contributing to range of motion limitation in hemiplegic shoulder pain because capsular stiffness in those patients was not as severe as that in adhesive capsulitis patients with similar range of motion limitation.

Capsule preservation improves short-term outcome of hydraulic distension in painful stiff shoulder

The effect of intraarticular hydraulic distension (IHD) for a painful stiff shoulder (or adhesive capsulitis) has been affirmed, but whether rupturing the joint capsule during this process is beneficial remains controversial. By monitoring real-time pressure-volume (PV) profiles during IHD, we could infuse the largest possible volume without rupturing the capsule. Using the novel technique, we compared the short-term effects of IHD when the capsule was preserved versus when it was ruptured. Fifty-four patients with a painful stiff shoulder underwent IHDs intended to preserve or rupture the capsule and then classified into capsule-ruptured (n = 26) and capsule-preserved (n = 20) groups, based on the obtained PV profiles. Their profiles were triphasic or biphasic; eight with flat profiles were excluded from the comparison. Clinical outcomes were evaluated at 3-day and 1-month follow-ups, in terms of pain and range of motion (ROM). Although both groups showed significant increase in ROM and decrease in pain after IHD, the improvements were greater in the capsule-preserved group than in the ruptured group at both follow-up times, and in triphasic and biphasic cases. In conclusion, the therapeutic effects of IHD in short-term follow-ups were enhanced by preserving the capsule.