The effect of pathological shoulder rhythm on muscle and joint forces after reverse shoulder arthroplasty, a numerical analysis.

BACKGROUND: Compromised abduction ability after reverse shoulder arthroplasty is primarily linked to limited glenohumeral range of motion while scapulothoracic mobility can typically be maintained. Glenohumeral joint forces strongly depend on the resulting scapulohumeral rhythm, however, an association between the acting muscle and joint forces and the subject-specific scapulohumeral rhythm after reverse shoulder arthroplasty has not been established. METHODS: Eleven reverse shoulder arthroplasty patients were divided into groups of poor and excellent abduction ability. Subject-specific models were developed and scaled for each patient using existing motion capture data in AnyBody™. Shoulder muscle and joint forces were obtained using inverse dynamics calculations during shoulder abduction to 100° in the scapula plane. The scapulohumeral rhythm, the resting abduction angle and internal body forces between the outcome groups were compared using a Mann Whitney U test. FINDINGS: The mean glenohumeral and scapulothoracic contribution to overall shoulder abduction for the excellent group was on average 9.7% higher and 21.4% lower, respectively, compared to the mean of the poor group. For shoulder abduction angles between 30° and 60°, the excellent group demonstrated on average 25% higher muscle forces in the anterior deltoid which was significantly higher compared to the poor outcome patients. Scapulothoracic muscle activity did not differ significantly between the two functional groups. INTERPRETATION: Accordingly, rehabilitation strategies focusing on strengthening the anterior part of the deltoid in particular may improve clinical outcomes.

Arthroscopically Assisted Stabilization of Chronic Acromioclavicular Joint Instability.

This video article demonstrates biological and synthetic acromioclavicular (AC) and coracoclavicular stabilization with use of a hamstring tendon graft and a low-profile TightRope implant (Arthrex). The low-profile TightRope reduces soft-tissue irritation due to knot stacks1. The tendon graft is wrapped around the clavicle and the coracoid to avoid weakening of the osseous structures as a result of clavicular and coracoidal tunnel placement2. Description: For this procedure, the patient is placed in the beach chair position. After establishing standard posterior, anteroinferior, and anterolateral (transtendinous) portals, the arthroscopic preparation of the coracoid base is performed. Next, transcoracoidal-transclavicular drilling is performed, and a nitinol suture passing wire is utilized to aid the placement of the TightRope later in the procedure. The graft passage around the clavicle and the coracoid is then set up by placing 2 additional nitinol suture passing wires. Following this, coracoclavicular stabilization is performed with use of the low-profile TightRope device, after which the graft is shuttled around the clavicle and the coracoid with the help of the passing wires. After the acromial drilling, the graft is shuttled laterally transacromially and subcutaneously back to the clavicle, completing the AC cerclage. Finally, the graft ends are sewn together under tension. The deltotrapezial fascia is closed above the graft, incorporating the tendon ends into the suture. Finally, the skin can be closed. Alternatives: In case of chronic AC joint injuries, many surgical stabilization techniques have been described. On the one hand there are rigid stabilization techniques like the hook-plate or temporary Kirschner wire fixation. On the other hand, there are dynamic stabilization techniques like the modified Weaver-Dunn procedure or solitary synthetic coracoclavicular reconstruction with use of pulley-like devices, with or without additional AC stabilization3. As for nonsurgical alternatives, physiotherapy with periscapular stabilization and muscle strengthening may be an option4. Rationale: For the treatment of chronic AC joint instability, many techniques5-9 have been described that utilized horizontal and vertical stabilization with a tendon graft combined with a synthetic pulley-like device. Usually, multiple transclavicular and transcoracoidal drill holes are utilized for the graft passage, which could weaken the bone and may result in postoperative fractures of the coracoid and clavicle10. Considering this, we present a modified technique that focuses on the optimization of the graft passage. In contrast to other aforementioned techniques, this procedure requires only 1 transcoracoidal-transclavicular tunnel for the TightRope and another transacromial tunnel for the passage of the AC cerclage. By forming a loop of the graft around the coracoid and the clavicle, the graft passage is managed without any additional coracoidal or clavicular drilling. Expected Outcomes: A dedicated study investigating the specific clinical and radiographic results of our technique will be part of future research. Because the biomechanical principle of reconstruction of our technique is very similar to the technique described by Kraus et al., we refer to their clinical and radiographic results regarding the expected outcome. As shown in the chart in the video, Kraus et al. demonstrated good clinical and radiographic results with their biologic and synthetic AC-stabilization technique at a median follow-up of 24 months. The outcomes measured in that study were the Constant score, Subjective Shoulder Value, AC Joint Instability Score, and Taft score. Patients were divided into 2 groups. Group 1 included patients with failed prior conservative treatment, and group 2 included those with failed prior surgical treatment. Overall, the authors report complete dynamic posterior translation in 1 patient and partial dynamic posterior translation in 5 patients. Although there was no notable enlargement of the TightRope drill hole, the authors of that study found a significant enlargement of the clavicular graft tunnels. However, the enlargement had no clinical relevance10. Important Tips: Utilize a low-profile TightRope device to minimize the risk of suture irritation from knot stacks.The tendon graft should be ≥24 cm in length. If the graft is too short, perform an end-to-end anastomosis of 2 grafts.Utilize an image intensifier to ensure correct drill hole placement and avoid damage to neurovascular structures.The graft passage around the clavicle and the coracoid can be dilated by hand with the use of differently sized drill bits.Incorporate the graft into fascial closure at the end of the procedure.

Is limited shoulder abduction associated with poor scapulothoracic mobility after reverse shoulder arthroplasty?

INTRODUCTION: The contribution of the glenohumeral joint to shoulder abduction is acknowledged as an important factor for reverse total shoulder arthroplasty (RTSA) patients. In contrast, the degree of scapulothoracic joint contribution and its relation to RTSA patients with poor to excellent shoulder abduction are unclear. MATERIALS AND METHODS: Twenty-three selectively recruited patients (74 ± 7 years, 11 males) with shoulder abduction ranging from poor to excellent at least 6 months after primary, unilateral RTSA participated in this study. Individual scapulothoracic and glenohumeral contributions at maximum shoulder abduction in the scapular plane were measured using 3D motion capture and correlations between scapulothoracic and glenohumeral contributions to shoulder abduction were assessed. Multiple regression analysis was used to determine the influence of age, body mass index, follow-up period, abduction strength and passive glenohumeral mobility on scapulothoracic and glenohumeral function. RESULTS: Maximum shoulder abduction (range 48°-140°) was not significantly correlated with the scapulothoracic contribution (range 39°-75°, r = 0.40, p = 0.06), but there was a strong and significant correlation with the glenohumeral contribution (range - 9°-83°, r = 0.91, p < 0.001). Abduction strength was strongly associated with glenohumeral (p = 0.006) but not scapulothoracic (p = 0.34) joint contributions. CONCLUSIONS: Limited shoulder abduction is not associated with insufficient scapulothoracic mobility, which rather provides a basic level of function for RTSA patients. Good to excellent shoulder abduction could only be achieved by increasing the glenohumeral contribution that was associated with postoperative abduction strength.

The Schulthess local Shoulder Arthroplasty Registry (SAR): cohort profile.

PURPOSE: Clinical registries are essential for evaluation of surgical outcomes. The Schulthess Shoulder Arthroplasty Registry (SAR) was established in 2006 to evaluate safety, function, quality-of-life and patient satisfaction in patients undergoing shoulder arthroplasty. PARTICIPANTS: Adult patients undergoing anatomic or reverse shoulder joint replacement at the Schulthess Klinik, a high-volume, leading orthopaedic surgery centre in Zürich, Switzerland. FINDINGS TO DATE: Between March 2006 and December 2019, the registry covered 98% of eligible operations. Overall, 2332 patients were enrolled with a total of 2796 operations and 11 147 person-years of follow-up. Mean age at baseline was 71 (range: 20-95), 65% were women. Most common indication was rotator cuff tears with osteoarthritis (42%) and the mean preoperative Constant Score was 31 (±15). The most frequent arthroplasty type was reverse, increasing from 61% in 2006-2010 to 86% in 2015-2019. Functional recovery peaked at 12-month postoperatively and did not show a clinically relevant deterioration during the first ten follow-up years. Since its establishment, the registry was used to address multiple pertinent clinical and methodological questions. Primary focus was on comparing different implant configurations (eg, glenosphere diameter) and surgical techniques (eg, latissimus dorsi transfer) to maximise functional recovery. Additionally, the cohort contributed to the determination of the clinical relevance and validity of radiological monitoring of cortical bone resorption and scapular notching. Finally, SAR data helped to demonstrate that returning to sports was among key patient expectations after reverse shoulder arthroplasty. FUTURE PLANS: As first patients are approaching the 15 years follow-up landmark, the registry will continue providing essential data on long-term functional outcomes, implant stability, revision rates and aetiologies as well as patient satisfaction and quality-of-life. In addition to research and quality-control, the cohort data will be brought back to the patients by bolstering real-time clinical decision support.

Short-term safety, function, and quality of life in patients treated with Univers Revers prosthesis: a multicenter 2-year follow-up case series.

BACKGROUND: The use of reverse total shoulder arthroplasty (RTSA) has dramatically increased in recent years with the advent of new prosthesis designs regularly entering the market. We define the rate of local complications during the first 2 years after RTSA with the Univers Revers prosthesis and describe the changes in radiologic outcomes, as well as function, pain, satisfaction, and quality of life. METHODS: This multicenter, prospective case series included rotator cuff tear arthropathy patients who underwent RTSA with the Univers Revers. Incidence percentages of complications and pathologic radiographic changes were documented. Mixed-model linear regression was used to examine changes in range of motion, shoulder function (Constant score, Shoulder Pain and Disability Index, Subjective Shoulder Value), and quality of life (EQ-5D-5L [European Quality of Life 5 Dimensions 5 Level] and EQ-VAS [EuroQol Visual Analog Scale]). RESULTS: Of 187 patients, 59.4% were women, and the mean age was 75.3 years (range, 56-91 years). Twenty-five percent of patients had a postoperative complication; 5 complications were severe (2.7%, 5 of 187), whereby 2 were implant related (1.1%; 95% confidence interval [CI], 0.1%-3.8%). The incidence of scapular notching was 10.6% (95% CI, 6.5%-16%). After 2 years, abduction, flexion, and abduction strength improved by 54° (95% CI, 50°-58°), 57° (95% CI, 53°-60°), and 5 kg (95% CI, 4-5 kg), respectively (P < .001), whereas external rotation at 0° (1°; 95% CI, -1° to 3°) did not improve (P = .4). The Constant score improved by 39 (95% CI, 38-41); Shoulder Pain and Disability Index, by 50 (95% CI, 47-52); and Subjective Shoulder Value, by 43 (95% CI, 41-45) (P < .001). Furthermore, the EQ-5D-5L index value improved by 0.31 (95% CI, 0.30-0.33), and the EQ-VAS score improved by 16 (95% CI, 14-18) (P < .001). CONCLUSION: Our case series showed a low complication rate with a consistent clinically relevant and statistically significant improvement across most clinical and patient-reported outcomes for the Univers Revers. Long-term safety requires further investigation.

Repair of Lafosse I subscapularis lesions brings no benefit in anterosuperior rotator cuff reconstruction.

PURPOSE: Optimal management of partial anterosuperior rotator cuff tears is unknown. Our aim was to compare clinical and subjective outcomes of supraspinatus (SSP) repair patients treated with or without repair of an associated superior subscapularis (SSC) partial tear. METHODS: SSP repair patients with an associated partial (Lafosse I) tear of the superior SSC tendon were retrospectively examined. Baseline and operative data and the outcomes of shoulder range of motion (ROM), pain level, strength, Constant-Murley Score, complications at 6 months as well as patient-reported Oxford Shoulder Score, Subjective Shoulder Value, and satisfaction at 6- and 24-month post-surgery were compared between patients with and without a repaired SSC tear. Mixed models and propensity-score matching were used to adjust baseline group differences. RESULTS: Of 75 eligible patients, 34 had an SSC repair and were younger with better baseline function. Non-repair surgeries were significantly shorter by 34 min (95% CI 23-45; p < 0.001). There were no group differences in the clinical and patient-rated outcome scores at both follow-ups (n.s.) as well as in pain, muscle strength in abduction, ROM, the 6-month complication risk (risk difference - 1.9%), and satisfaction with postoperative shoulder condition (n.s.). CONCLUSION: We could not show a functional or subjective benefit of repairing cranial partial tears of the SSC tendon over debridement only in the setting of an SSP reconstruction with 24 months of follow-up. A longer operative duration is expected if a partial SSC tear repair is performed. LEVEL OF EVIDENCE: III.

Limited reliability of grading scapular notching according to Nerot-Sirveaux on anteroposterior radiographs.

INTRODUCTION: Incidences of scapular notching (SN) in reverse shoulder arthroplasty (RSA) range between 0% and 96%, and controversy remain as to its relevance for patient outcome. We assessed the reliability of scapular notching (SN) grading based on the Sirveaux classification system using anteroposterior radiographs. MATERIALS AND METHODS: 206 RSA procedures with 5-year postoperative anteroposterior shoulder radiographs were classified independently by seven assessors according to Sirveaux (session 1). After a review meeting, three assessors re-classified the radiographs along with quality criteria (session 2). SN grading by the majority of assessors was taken as the reference. Classification interobserver reliability was analyzed using Kappa statistics. RESULTS: The incidence of SN was estimated at 53% and 37% at the first and second sessions, respectively. Interobserver reliability Kappa coefficients resulting from the first and second sessions were 0.27 and 0.43, respectively. Case selection based on radiographic quality criteria did not improve SN grading reliability in the second session. CONCLUSION: Agreement between individual surgeons was low when grading SN in RSA according to Sirveaux using anteroposterior radiographs. Consensus among several assessors may increase reliability in research settings.

Risk of insufficient internal rotation after bilateral reverse shoulder arthroplasty: clinical and patient-reported outcome in 57 patients.

BACKGROUND: Bilateral reverse shoulder arthroplasty (RSA) is controversial because of potential rotational deficits impairing daily living activities. We assessed achievement of insufficient internal rotation (IR) and associated factors in bilateral RSA patients. METHODS: Fifty-seven staged bilateral RSA patients with a minimum of 1 year of follow-up after the second intervention were identified from our local monocentric register. Shoulder range of motion (including IR using the Apley scratch test), strength, and Constant and Shoulder Pain and Disability Index scores were assessed preoperatively and 6, 12, and 24 months postoperatively. RESULTS: Before surgery, both shoulders were similar regarding imaging parameters, but first operated shoulders tended to have poorer function. One year after the first RSA, 21% of patients had insufficient IR (not reaching the lumbosacral junction) compared with 33% after the second intervention (P = .180). At 2 years, 5% of patients had insufficient IR on both sides. Patients with insufficient IR on the second side at baseline (relative risk [RR], 1.8 [1.0-3.2]) and patients with insufficient IR 1 year after the first RSA (RR, 3.0 [1.6-5.6]) were more likely to have insufficient IR 1 year after the second RSA. Constant and Shoulder Pain and Disability Index scores and abduction of the second side were significantly worse 1 year after the second RSA (P ≤ .047); at 2 years, there were no differences in functional outcome between shoulders. CONCLUSION: A minority of bilateral RSA patients did not achieve sufficient IR on at least 1 side. Staged surgery is justified, particularly when the outcome of the initial operation is satisfactory.

State strategies to avoid antitrust concerns in multipayer medical home initiatives.

Currently, 20 states have had one or more active multipayer medical home initiatives. As more states convene multiple payers and work to align payment policies, concerns regarding antitrust liability will need to be addressed. This issue brief provides a summary of state strategies to navigate antitrust concerns in multipayer medical home initiatives. Information for this brief was obtained from a survey sent to 14 states combined with a scan of state websites. Nine states have policies in place either through legislation or executive order to provide some legal protection for their efforts to displace competition among payers. Out of concern that legislation was not sufficient, policymakers in one state also conducted oversight activities to reduce the risk of antitrust liability. Six of the 14 states surveyed have engaged in multipayer initiatives without formal antitrust protection.

Facilitatory neuromodulative effect of duloxetine on pudendal motor neurons controlling the urethral pressure: a functional urodynamic study in healthy women.

OBJECTIVE: The aim of this functional urodynamic experiment in healthy women was to study the effect of duloxetine, which is a combined serotonin and norepinephrine (5-HT/NE) reuptake inhibitor, on urethral resting pressure, excitability of pudendal motor neurons, and urethral sphincter contractility. METHODS: In 11 healthy female subjects three baseline urethral pressure profiles (UPPs) were obtained to study resting pressure. Afterward the individual motor threshold (MT) for external urethral sphincter (EUS) contraction in response to transcranial magnetic stimulation (TMS) was determined to study the excitability of pudendal motor neurons. Another three UPPs were recorded while sacral root magnetic stimulation (SMS) was performed to evoke reproducible urethral contractions to study urethral sphincter contractility. Then the women received 40 mg duloxetine and the protocol was repeated 4 h after drug administration. The resting pressure values, MT values following TMS, and the EUS pressure amplitudes in response to SMS obtained at baseline were statistically compared to the corresponding values at follow-up after duloxetine. RESULTS: Oral administration of duloxetine significantly lowered MT for EUS contraction in response to TMS (p=0.013). In addition, duloxetine significantly increased EUS pressure amplitudes in response to SMS (p=0.0007, 5 of 11 subjects evaluated) but did not change urethral resting pressures. CONCLUSIONS: This is the first functional, urodynamic controlled study to show that the combined 5-HT/NE reuptake inhibitor duloxetine has a significant effect on the excitability of pudendal motor neurons and on urethral sphincter contractility in healthy women in vivo but no significant effect on urethral resting tone. Our data confirm a facilitatory neuromodulative effect of duloxetine on sphincter motor neurons in humans.