Complications of reverse shoulder arthroplasty: a concise review

Humeral stem alignment of curved short stem in reverse shoulder arthroplasty: varus/valgus alignment is not a determinant for clinical outcomes

BACKGROUND

This study aimed to investigate the influence of curved short stem alignment within the proximal humerus on the clinical outcomes of reverse shoulder arthroplasty. We hypothesized that the varus/valgus alignment would yield clinical outcomes comparable to those of a neutral alignment.

METHODS

We retrospectively reviewed 167 patients who underwent reverse shoulder arthroplasty using the Aequalis Ascend Flex implant between January 2017 and December 2021. The study categorized the patients into 3 groups based on the angle difference between the humeral axis and the stem axis: neutral group (GN, defined as within ±5°), valgus group (GL), and varus group (GR). Functional outcomes were assessed using the visual analog scale pain score, subjective shoulder value, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and active range of motion. Routine radiographic evaluations were also conducted to assess the filling ratio and bone resorption.

RESULTS

Among 138 patients, 89 were in the GN group, 37 (27%) in the GL group, and 12 (9%) in the GR group. The average degree of varus alignment was 6 (range from 5 to 7°), while the average degree of valgus alignment was -7 (range from -8 to -5°). According to our findings, the clinical outcomes did not exhibit significant differences among the 3 groups. Furthermore, the radiologic outcomes showed no significant differences among the 3 groups.

CONCLUSIONS

Compared to neutral alignment, varus or valgus alignment of the humeral stem in reverse shoulder arthroplasty using a curved short stem does not significantly affect clinical outcomes.

Cutibacterium acnes in Shoulder Surgery: Is It a Significant Risk Factor for Postoperative Infection?

Cutibacterium acnes, a commensal, lipophilic, anaerobic Gram-positive bacterium, is well known for its potential to cause infections, particularly in the field of orthopedics, notably in the shoulder. However, its indolent strain nature presents challenges in the diagnosis of the bacterium using clinical, laboratory, and culture-based methods. There are controversies surrounding its actual threat as an infection-causing agent, leading to an incomplete consensus on treatment strategies after the infection. Furthermore, research is ongoing to explore preventive procedures before the onset of infection. This review aimed to comprehensively explore the diagnosis and treatment of C. acnes and determine whether it is a risk factor for shoulder joint infections.

Acquired Acromion Compromise, Including Thinning and Fragmentation, Is Not Associated With Poor Outcomes After Reverse Shoulder Arthroplasty

BACKGROUND

Acquired acromial compromise, including thinning (less than 30% of the normal acromion) or fragmentation resulting from acromiohumeral impingement or previous acromioplasty, is a concern in reverse shoulder arthroplasty (RSA). This condition may lead to shoulder pain and difficulties in arm elevation because of acromial insufficiency fracture.

QUESTIONS/PURPOSES

(1) Do patients with acromial compromise (thinning less than 30% of normal acromion or fragmentation) have worse functional outcome scores, ROM, and strength after RSA compared with patients without acromial compromise? (2) Are patients with acromial compromise at a higher risk of complications such as acromial insufficiency fracture after RSA? (3) Do patients who develop acromial insufficiency fracture have predisposing associated factors and worse clinical outcomes?

METHODS

Between January 1, 2016, and December 31, 2020, we treated 398 patients with RSA, and all patients were considered potentially eligible for this study. Our clinic is part of the orthopaedic department within a tertiary general hospital, serving patients from across the country. Among them, 49% (197 of 398) of patients were excluded for the following reasons: 8% (31 of 398) because of proximal humerus fracture, 5% (19 of 398) because of osteonecrosis, 9% (35 of 398) because of previous infective arthritis, 5% (18 of 398) because of a deformed shoulder, 4% (14 of 398) because of poor general condition after surgery, 3% (12 of 398) because of death, and another 17% (68 of 398) were lost before the minimum study follow-up, leaving 51% (201 of 398) for analysis. A preoperative acromial compromise was defined as follows: (1) thinning of the acromion (< 3 mm), which means a thickness of less than 30% of the normal acromion thickness (8 to 9 mm), and (2) acromial fragmentation. Acromial thickness was measured using a CT scan. The middle portion of the anterolateral acromion, situated lateral to the distal end of the clavicle, was crosschecked using the axial view. Measurements were subsequently performed from both coronal and sagittal views. In all, 29 patients with acromion compromise and 172 without acromion compromise met the inclusion and exclusion criteria. There was no differential loss to follow-up before 2 years between patients with and without acromial compromise in this study (36% [16 of 45] versus 23% [52 of 224]; p = 0.12). We matched patients using propensity score, pairing them in a 1:3 ratio based on gender, age, bone mineral density, diagnosis, previous rotator cuff repair surgery, subscapularis repair or latissimus dorsi transfer performed during surgery, the type of prosthesis used, and follow-up duration. Twenty-three patients with acromial compromise (acromion compromised group) and 69 patients without acromial compromise (normal control group) were matched; the mean ± SD duration of follow-up was 40 ± 22 months in those with acromial compromise and 43 ± 19 months the in normal control group. Pre- and postoperative functional outcome scores, ROM, and shoulder strength were compared. Shoulder scaption refers to lifting the arm in the scapular plane, and scaption strength was measured by applying upward force with the arm at 90° while seated, pushing it as far as possible and measured using a handheld myometer. Complications, including acromial insufficiency fracture, scapular notching, dislocation, periprosthetic infection, and overall risk of complication, were analyzed. Acromial insufficiency fracture was diagnosed based on clinical and radiological findings. Clinically, sudden pain and tenderness at the acromion along with reduced shoulder elevation raised acromial insufficiency fracture suspicion. Radiologically, acromion tilt on plain radiograph or fracture line on coronal CT view confirmed diagnosis of acromial insufficiency fracture.

RESULTS

Comparing both groups, patients with a compromised acromion had no difference in American Shoulder and Elbow Surgeons scores (60 ± 12 versus 64 ± 12; mean difference -4 [95% CI -11 to 2]; p = 0.16), Constant scores (48 ± 10 versus 54 ± 12; mean difference -6 [95% CI -13 to 0]; p = 0.06), forward flexion degree (125 ± 24 versus 130 ± 21; mean difference -5 [95% CI -16 to 6]; p = 0.36), and scaption strength (5 ± 3 versus 6 ± 3; mean difference -1 [95% CI -3 to 0]; p = 0.13). Having acromial compromise was not associated with increased risk of overall complications (30% [7 of 23] versus 19% [13 of 69], relative risk 2 [95% CI 1 to 4]; p = 0.26). However, the only complication that was higher in the acromial compromised group was infection (13% [3 of 23] versus 0% [0 of 69], relative risk not available; p = 0.01). Only the lateralized glenoid prosthesis demonstrated negative association with the acromial insufficiency fracture occurrence; no other factors showed an association. The use of lateralized glenoid prostheses was not observed in patients with acromial insufficiency fracture (0% [0 of 7] acromial insufficiency fracture versus 39% [33 of 85] no acromial insufficiency fracture, relative risk 0 [95% CI 0]; p = 0.047).

CONCLUSION

In patients with acquired acromial compromise-such as thinning or fragmented acromion because of advanced cuff tear arthropathy or previous acromioplasty-primary RSA resulted in no different functional outcome score, ROM, shoulder strength, and overall complications compared with patients without acromial compromise. Our findings suggest that a thin or fragmented acromion may not necessarily be exclusion criteria for RSA, potentially aiding surgeons in their decision-making process when treating these patients. However, one of the major complications, postoperative infection, is more frequently observed in patients with acquired acromial compromise. Pre- and postoperative caution would be necessary to prevent and detect infection even when short-term outcomes are favorable in this study. Further studies with large cohorts and long-term follow-up durations are needed.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Primary Arthroscopic Repair for Massive Rotator Cuff Tears Results in Good Shoulder Function, Low Pain, and Satisfactory Outcomes at 2-Year Minimum Follow-Up

PURPOSE

To evaluate outcomes of patients who underwent primary arthroscopic repair for massive rotator cuff tears (MRCTs).

METHODS

Patients with MRCTs (full-thickness tear of 2 or more tendons or full-thickness tear ≥5 cm) who underwent arthroscopic repair with a minimum follow-up of 2 years were retrospectively reviewed (n = 51). All patients had preoperative magnetic resonance imaging used to characterize pattern of tear, degree of fatty degeneration (Goutallier classification), and degree of rotator cuff arthropathy (Hamada classification). Outcomes were determined by American Shoulder and Elbow Surgeons (ASES) scores and Penn Shoulder Scores (PSS).

RESULTS

A total of 51 patients with a minimum 2.3-year follow-up (mean, 5.4 years; range, 2.3-9.7 years) were included in this study. Mean ASES score was 46.1 ± 7.8 (95% CI, 43.9-48.3) for pain and 39.4 ± 12.1 (95% CI, 36.0-42.8) for function. Total ASES score averaged 85.5 ± 18.4 (95% CI, 80.4-90.7). PSS had a mean pain score of 26.8 ± 4.4 (95% CI, 25.4-28.1), a mean satisfaction score of 7.9 ± 2.9 (95% CI, 7.0-8.2), and a mean function score of 48.5 ± 13.5 (95% CI, 44.7-52.3). Total PSS averaged 83.2 ± 19.6 (95% CI, 77.7-87.7). No correlation was found between Goutallier grade and ASES/PSS scores or between Hamada grade and ASES/PSS scores. Three patients underwent reoperation after primary arthroscopic repair of an MRCT (5.9%).

CONCLUSIONS

Patients with MRCTs who undergo primary arthroscopic repair have postoperative outcome scores indicative of good shoulder function, low pain, and high satisfaction. The rate of reoperation for individuals who underwent primary arthroscopic repair with MRCTs was low at 6%.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Radial and median nerves distal peripheral tension after reverse shoulder arthroplasty: a cadaveric study

Background

Peripheral nerve injury is a recognized complication after reverse shoulder arthroplasty (RSA) that has mainly been studied at the level of the brachial plexus and its proximal branches. However, the impact of RSA on distal peripheral nerves and the influence of elbow and wrist position is not known. This cadaveric study aimed to analyze the effect of RSA implantation and upper limb position on tension in the distal median and radial nerves. The hypothesis was that RSA increased distal nerve tension, which could be further affected by elbow and wrist position.

Methods

12 upper limbs in 9 full fresh-frozen cadavers were dissected. Nerve tension was measured in the median nerve at the level of the proximal arm, elbow, and distal forearm, and in the radial nerve at the level of the elbow, using a customized three-point tensiometer. Measurements were carried out before and after RSA implantation, using a semi-inlay implant (Medacta, Castel San Pietro, Switzerland). Two different configurations were tested, using the smallest and largest available implant sizes. Three upper-limb key positions were considered (plexus at risk, plexus relief, and neutral), from which the effect of elbow and wrist position was further tested.

Results

RSA implantation significantly increased median and radial nerve tension throughout the upper limb. The distal nerve segments were particularly dependent on elbow and wrist position. The plexus at risk position induced the most tension in all nerve segments, especially with the large implant configuration. On the other hand, the plexus relief position induced the least amount of tension. Flexing the elbow was the most efficient way to decrease nerve tension in all tested nerve segments and key positions. Wrist flexion significantly decreased nerve tension in the median nerve, whereas wrist extension decreased tension in the radial nerve.

Conclusion

RSA significantly increases tension in the median and radial nerves and makes them more susceptible to wrist and elbow positioning. The mechanism behind distal peripheral neuropathy after RSA may thus result from increased compression of tensioned nerves against anatomical fulcrums rather than nerve elongation alone. Elbow flexion was the most effective way to decrease nerve tension, while elbow extension should be avoided when implanting the humeral component. Further studies are needed to assess the ulnar nerve.

Acute-on-Chronic Axillary Artery Thrombus After Reverse Total Shoulder Arthroplasty for Failed Proximal Humerus Open Reduction and Internal Fixation: A Case Report

CASE

A 71-year-old woman presented with post-traumatic arthritis 11 months after open reduction and internal fixation for a left proximal humerus fracture (PHF) dislocation. After revision to reverse total shoulder arthroplasty (rTSA), the patient's left upper extremity was found to be avascular. An emergent thrombectomy was performed with restoration of arterial flow after removal of an acute-on-chronic axillary artery thrombus.

CONCLUSION

Although rare, as rTSA becomes more common for management of PHF, incidence of associated vascular injuries is likely to rise. Screening methods and clinical vigilance in diagnosis are advised for patients with anterior PHF dislocations and arterial injury risk factors.

Clinical and radiological outcomes with an augmented baseplate for superior glenoid wear in reverse shoulder arthroplasty

Aims

This study aimed to assess the impact of using the metal-augmented glenoid baseplate (AGB) on improving clinical and radiological outcomes, as well as reducing complications, in patients with superior glenoid wear undergoing reverse shoulder arthroplasty (RSA).

Methods

From January 2016 to June 2021, out of 235 patients who underwent primary RSA, 24 received a superior-AGB after off-axis reaming (Group A). Subsequently, we conducted propensity score matching in a 1:3 ratio, considering sex, age, follow-up duration, and glenoid wear (superior-inclination and retroversion), and selected 72 well-balanced matched patients who received a standard glenoid baseplate (STB) after eccentric reaming (Group B). Superior-inclination, retroversion, and lateral humeral offset (LHO) were measured to assess preoperative glenoid wear and postoperative correction, as well as to identify any complications. Clinical outcomes were measured at each outpatient visit before and after surgery.

Results

There were no significant differences in demographic data and preoperative characteristics between the two groups. Both groups showed significant improvements in patient-reported outcome measures (visual analogue scale for pain, visual analogue scale for function, American Shoulder and Elbow Surgeons, Constant, and Simple Shoulder Test scores) from preoperative to final assessment (p < 0.001). However, AGB showed no additional benefit. Notably, within range of motion, Group B showed significant postoperative decrease in both external rotation and internal rotation, unlike Group A (p = 0.028 and 0.003, respectively). Both groups demonstrated a significant correction of superior-inclination after surgery, while patients in Group B exhibited a significant decrease in LHO postoperatively (p = 0.001). Regarding complications, Group A experienced more acromial stress fractures (3 cases; 12.5%), whereas Group B had a higher occurrence of scapular notching (24 cases; 33.3%) (p = 0.008).

Conclusion

Both eccentric reaming with STB and off-axis reaming with AGB are effective methods for addressing superior glenoid wear in RSA, leading to improved clinical outcomes. However, it is important to be aware of the potential risks associated with eccentric reaming, which include excessive bone loss leading to reduced rotation and scapular notching.

SPECT/CT for Early Detection of Stress Reactions After Reverse Shoulder Arthroplasty: Potential Clinical Significance

ABSTRACT

The altered biomechanics after reverse shoulder arthroplasty, combined with the accumulation of various stress risers, can lead to stress fractures (SFs) around the prosthesis. The incidence of stress reactions (SRs) after reverse shoulder arthroplasty, characterized by pain and tenderness without radiographic or CT evidence of fractures, is approximately 4.2%, which is comparable to the incidence of SF (6.4%). Among patients with SR, a substantial 32% eventually progress to fractures during clinical follow-up. SPECT/CT is a promising tool that combines morphologic and metabolic information for assessing mechanical bone stress. Therefore, early detection of SR through SPECT/CT can help prevent SF.

The Treatment of Periprosthetic Fracture Revision of the Humerus with "Bamboo Support" Structural Allograft Technique-Atrophic Non-Union of a Post-Operative Periprosthetic Fracture after Reverse Total Shoulder Arthroplasty: A Case Report

Periprosthetic fractures are a serious complication of joint replacement surgery. With the growing prevalence of reverse total shoulder arthroplasty (RTSA), the incidence of relatively uncommon periprosthetic humeral fractures has increased. Here, we present the unique case of a 74-year-old woman who developed atrophic non-union after plate osteosynthesis for a periprosthetic fracture associated with RTSA. Fixation failure was evident 3 months after the surgical intervention; the patient underwent a 3-month course of arm sling immobilization. However, bone resorption continued, and varus angulation of the fracture developed. In this case, surgical strategy involved the use of long proximal humerus internal locked system plate (DePuy Synthes, Paoli, PA, USA), augmented with autologous iliac bone graft and allogenic humerus structural bone graft with the "bamboo support technique", fixed with Cable System (DePuy Synthes, Paoli, PA, USA). No reports have addressed the management of failed periprosthetic fractures using allogeneic humeral strut bone grafts. This report aims to fill the gap by presenting a novel surgical technique for the management of periprosthetic fractures associated with RTSA in case of treatment failure.

The Impact of Preoperative Co-morbidities on Blood Transfusion Requirements Following Reverse Total Shoulder Arthroplasty

Objectives

Reverse total shoulder arthroplasty (RTSA) continues to increase in popularity as a surgical operation in the United States. As indications for this procedure expand, more attention is needed to evaluate perioperative risk factors and patient characteristics. Postoperative anemia requiring blood transfusion (BT) is a well-documented risk factor for increased in-house mortality although little has been studied on the relationship between RTSA and postoperative BT. The purpose of this study was to identify comorbidities and patient characteristics as risk factors for BT in patient's undergoing RTSA.

Methods

Using the Nationwide Inpatient Sample (NIS) database, 59,925 RTSA patients (2016-2019) were analyzed, with 1.96% requiring postoperative BT. Demographics, comorbidities, and preoperative factors were compared between BT and non-BT groups via univariate and multivariate analyses.

Results

Overall prevalence of blood transfusion in all patients was 1.96%. Male sex (OR 1.75, p < 0.001), Asian ethnicity (OR 1.96, p = 0.012), age >80 (OR 1.51, p < 0.001), age >90 (OR 2.26, p < 0.001), CKD (OR 1.94, p < 0.001), and Parkinson's disease (OR 2.08, p < 0.001) were associated with increased BT odds. Cirrhosis exhibited the highest impact (OR 5.7, p < 0.001). Conversely, Caucasian ethnicity (OR 0.76, p = 0.023), uncomplicated DM (OR 0.73, p = 0.002), tobacco-related disorders (OR 0.43, p < 0.001), BMI >30 (OR 0.8, p = 0.011), and elective procedures (OR 0.16, p < 0.001) decreased BT odds.

Conclusion

These results were useful with identifying several risk factors that predispose to a higher risk of postoperative BT in patients undergoing RTSA including male sex, people of Asian descent, age > 80, CKD, Parkinson's disease, and cirrhosis. These findings provide clinicians with information that may be helpful with preoperative planning and perioperative management of complex patient populations.

Factors that increase the rate of periprosthetic dislocation after reverse shoulder arthroplasty

INTRODUCTION

Reverse shoulder arthroplasty (RSA) is considered one of the greatest technological innovations in shoulder reconstruction surgery, as evidenced by the fact its growth rate of usage is greatest among all shoulder arthroplasties. However, like all arthroplasties, a post-surgical complication often arises. One of these complications, periprosthetic dislocation (PPD), requires revision and poses, therefore, a burden on both patients and healthcare providers. While PPD is understood to be a complication of RSA, it is unclear to what extent certain risk factors and co-morbidities predispose patients to post-RSA PPD. The purpose of this study was to identify and evaluate the impact of specific risk factors and co-morbidities that contribute to the development of PPD following RSA.

METHODS

In this retrospective study, we used the Nationwide Inpatient Sample (NIS) database from 2016-2019 to analyze the prevalence and impact of various risk factors and co-morbidities on the incidence of PPD following RSA. A univariate and subsequent multivariate logistic regression model was made to provide a descriptive association between variables that impact the rates of PPD after RSA.

RESULTS

The NIS database identified 59,925 patients, 1,000 of whom experienced a PPD while the remaining 58,825 were placed in the non-PPD group (controls). The PPD group consisted predominantly of females (53.10%) and Caucasians (86.30%). There was a higher incidence of tobacco-related disorders (P = 0.003), obesity (P < 0.001), morbid obesity (P < 0.001), liver cirrhosis (P < 0.001), and Parkinson's disease (PD) (P < 0.001) in PPD patients compared to controls. Young patients had a 1.89-fold increased odds (OR: 1.89, 95% CI [1.58, 2.26], P < 0.001), patients with tobacco-related disorders had decreased odds (OR: 0.80, 95% CI [0.67, 0.97], P = 0.02), morbidly obese patients had 1.50 times the odds (OR: 1.50, 95% CI [1.14, 1.97]), liver cirrhosis patients had 2.67-fold increased odds (OR: 2.67, 95% CI [1.55, 4.60], P < 0.001), and Parkinson's disease patients had 2.66 times the odds (OR: 2.66, 95% CI [1.78, 3.96], P < 0.001) to develop PPD following RSA compared to patients who did not have the corresponding condition.

CONCLUSIONS

Patients with specific risk factors and co-morbidities are predisposed to developing PPD after RSA. Risk factors that were found to be associated with a higher incidence of PPD are gender (female), race (Caucasian), and age (young patients). Analysis revealed the history of tobacco-related disorder, obesity, morbid obesity, liver cirrhosis, and Parkinson's disease increased the odds of developing PPD following RSA. These findings can inform both healthcare providers and patients to improve RSA surgical outcomes and tailor post-surgery recovery programs to fit the patient's needs.

Return to Sports Activity After Reverse Total Shoulder Arthroplasty

Background

There are little published data on return to sports (RTS) after reverse total shoulder arthroplasty (RTSA).

Purpose

To (1) determine the rate and timing of RTS after RTSA in an Asian population, (2) analyze predictive factors for RTS, and (3) determine the relationship between RTS after RTSA and clinical/radiological outcomes.

Study Design

Case-control study; Level of evidence, 3.

Methods

A retrospective review was performed on consecutive patients with diagnosis of irreparable rotator cuff tear (RCT), cuff tear arthropathy (CTA), or degenerative osteoarthritis who underwent RTSA between May 2017 and May 2020. Included were patients who played sports preoperatively in ≤3 years and had ≥2-year follow-up. Patients were divided into 2 groups based on responses to a telephone survey about RTS after RTSA: those who returned to sports (group A) and those who did not (group B). Patient characteristics, pre- and postoperative clinical features and functional scores, and radiologic outcomes (acromial fracture, scapular notching, heterotopic ossification, and loosening of humeral and glenoid component) were compared between the groups.

Results

Of 59 eligible patients, 44 patients (28 in group A, 16 in group B) were included. The RTS rate after RTSA was 63.6%, and the mean RTS time was 9.1 months (range, 3-36 months). There was a significant group difference in body mass index (BMI) (group A, 24.3 ± 2.1; group B, 27.1 ± 4.4; P = .01) and preoperative diagnosis (CTA/irreparable RCT/degenerative osteoarthritis diagnoses: group A, 13/12/3; group B, 3/6/7; P = .03). Patients in group A showed significantly higher forward flexion (P = .03) and higher Simple Shoulder Test score (P = .02) than group B at final clinical follow-up. No significant difference in radiological outcomes was found between the groups.

Conclusion

Patients with a low BMI and those diagnosed with CTA or irreparable RCT were found to have better RTS rates after undergoing RTSA, and forward flexion and Simple Shoulder Test scores at final follow-up were significantly higher in the RTS group, with no significant differences in complications.

Effects of anti-osteoporosis therapy on the risk of secondary fractures and surgical complications following surgical fixation of proximal humerus fracture in older people

BACKGROUND

age-related fragility fractures cause significant burden of disease. Within an ageing society, fracture and complication prevention will be essential to balance health expenditure growth.

OBJECTIVE

to assess the effect of anti-osteoporotic therapy on surgical complications and secondary fractures after treatment of fragility fractures.

PATIENTS AND METHODS

retrospective health insurance data from January 2008 to December 2019 of patients ≥65 years with proximal humeral fracture (PHF) treated using locked plate fixation (LPF) or reverse total shoulder arthroplasty were analysed. Cumulative incidences were calculated by Aalen-Johansen estimates. The influence of osteoporosis and pharmaceutical therapy on secondary fractures and surgical complications were analysed using multivariable Fine and Gray Cox regression models.

RESULTS

a total of 43,310 patients (median age 79 years, 84.4% female) with a median follow-up of 40.9 months were included. Five years after PHF, 33.4% of the patients were newly diagnosed with osteoporosis and only 19.8% received anti-osteoporotic therapy. A total of 20.6% (20.1-21.1%) of the patients had at least one secondary fracture with a significant reduction of secondary fracture risk by anti-osteoporotic therapy (P < 0.001). An increased risk for surgical complications (hazard ratio: 1.35, 95% confidence interval: 1.25-1.47, P < 0.001) after LPF could be reversed by anti-osteoporotic therapy. While anti-osteoporotic therapy was more often used in female patients (35.3 vs 19.1%), male patients showed significantly stronger effects reducing the secondary fracture and surgical complication risk.

CONCLUSIONS

a significant number of secondary fractures and surgical complications could be prevented by consequent osteoporosis diagnosis and treatment particularly in male patients. Health-politics and legislation must enforce guideline-based anti-osteoporotic therapy to mitigate burden of disease.

Iatrogenic Ulnar Nerve Neuropathy Following Reverse Total Shoulder Arthroplasty: Electrodiagnostic Findings in 18 Patients

Background A reverse total shoulder arthroplasty (RTSA) is often recommended for rotator cuff pathology and may be associated with a myriad of complications, including prosthetic instability, infection, humeral problems, and glenoid loosening. Neurological injuries following an RTSA are infrequent and are usually related to brachial plexus or proximal nerve injury in the affected arm. Iatrogenic ulnar nerve neuropathy is exceedingly rare. Aims This study describes the clinical and electrodiagnostic (EDX) features of 18 patients with ulnar nerve neuropathy complicating RTSA. Materials and methods All patients underwent EDX studies, and 14 had an ultrasound (US) study. Results All patients complained of numbness, tingling, hyperalgesia, and/or allodynia in the distribution of the ulnar nerve. Eight (44%) patients reported hand weakness, and one (6%) noted wasting of the intrinsic hand muscles. Decreased pinprick sensation in the ulnar nerve distribution was detected in all patients. Seventeen (94%) patients had weakness of the ulnar nerve-innervated intrinsic hand muscles. All patients had focal slowing of the motor conduction of the ulnar nerve across the elbow. Sensory potentials were either absent or of a low amplitude over the digital and/or dorsal cutaneous branch of the ulnar nerve in all patients. Twelve (86%) patients showed an increase in the cross-sectional area (CSA) of the ulnar nerve at the elbow; six (43%) had a hypoechoic ulnar nerve. Ulnar nerve neuropathy was confirmed at the elbow in all 18 patients. Of the 14 (78%) patients who underwent surgical intervention for ulnar nerve neuropathy following an RTSA, only four had complete symptom resolution. Conclusions Surgeons should be cognizant of ulnar nerve neuropathy as a potential complication of an RTSA and take precautions to avoid damage to the ulnar nerve intraoperatively. EDX and US studies should be performed to confirm and assess the site and severity of the injury.

Reverse shoulder arthroplasty versus hemiarthroplasty versus non-surgical treatment for older adults with acute 3- or 4-part fractures of the proximal humerus: study protocol for a randomised controlled trial (PROFHER-2: PROximal Fracture of Humerus Evaluation by Randomisation - Trial Number 2)

BACKGROUND

Proximal humerus fractures (PHF) are common and painful injuries, with the majority resulting from falls from a standing height. As with other fragility fractures, its age-specific incidence is increasing. Surgical treatment with hemiarthroplasty (HA) and reverse shoulder arthroplasty (RSA) have been increasingly used for displaced 3- and 4-part fractures despite a lack of good quality evidence as to whether one type of arthroplasty is superior to the other, and whether surgery is better than non-surgical management. The PROFHER-2 trial has been designed as a pragmatic, multicentre randomised trial to compare the clinical and cost-effectiveness of RSA vs HA vs Non-Surgical (NS) treatment in patients with 3- and 4-part PHF.

METHODS

Adults over 65 years of age presenting with acute radiographically confirmed 3- or 4-part fractures, with or without associated glenohumeral joint dislocation, who consent for trial participation will be recruited from around 40 National Health Service (NHS) Hospitals in the UK. Patients with polytrauma, open fractures, presence of axillary nerve palsy, pathological (other than osteoporotic) fractures, and those who are unable to adhere to trial procedures will be excluded. We will aim to recruit 380 participants (152 RSA, 152 HA, 76 NS) using 2:2:1 (HA:RSA:NS) randomisation for 3- or 4-part fractures without joint dislocation, and 1:1 (HA:RSA) randomisation for 3- or 4-part fracture dislocations. The primary outcome is the Oxford Shoulder Score at 24 months. Secondary outcomes include quality of life (EQ-5D-5L), pain, range of shoulder motion, fracture healing and implant position on X-rays, further procedures, and complications. Independent Trial Steering Committee and Data Monitoring Committee will oversee the trial conduct, including the reporting of adverse events and harms.

DISCUSSION

The PROFHER-2 trial is designed to provide a robust answer to guide the treatment of patients aged 65 years or over who sustain 3- and 4-part proximal humeral fractures. The pragmatic design and recruitment from around 40 UK NHS hospitals will ensure immediate applicability and generalisability of the trial findings. The full trial results will be made available in a relevant open-access peer-reviewed journal.

TRIAL REGISTRATION

ISRCTN76296703. Prospectively registered on 5th April 2018.

Implant selection for successful reverse total shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) emerged as a new concept of arthroplasty that does not restore normal anatomy but does restore function. It enables the function of the torn rotator cuff to be performed by the deltoid and shows encouraging clinical outcomes. Since its introduction, various modifications have been designed to improve the outcome of the RTSA. From the original cemented baseplate with peg or keel, a cementless baseplate was designed that could be fixed with central and peripheral screws. In addition, a modular-type glenoid component enabled easier revision options. For the humeral component, the initial design was an inlay type of long stem with cemented fixation. However, loss of bone stock from the cemented stem hindered revision surgery. Therefore, a cementless design was introduced with a firm metaphyseal fixation. Furthermore, to prevent complications such as scapular notching, the concept of lateralization emerged. Lateralization helped to maintain normal shoulder contour and better rotator cuff function for improved external/internal rotation power, but excessive lateralization yielded problems such as subacromial notching. Therefore, for patients with pseudoparalysis or with risk of subacromial notching, a medial eccentric tray option can be used for distalization and reduced lateralization of the center of rotation. In summary, it is important that surgeons understand the characteristics of each implant in the various options for RTSA. Furthermore, through preoperative evaluation of patients, surgeons can choose the implant option that will lead to the best outcomes after RTSA.

Does reverse shoulder arthroplasty improve emotional status and quality of life in patients with rotator cuff insufficiency? Prospective sequential follow-up study

BACKGROUND

The purpose of this study was to investigate sequential changes of emotional status and quality of life after reverse shoulder arthroplasty (RSA) for rotator cuff insufficiency and to determine the predictors that can affect postoperative clinical outcomes. This study was conducted to prove the hypothesis that RSA would improve emotional status and quality of life.

METHODS

Fifty patients undergoing RSA for rotator cuff insufficiency were prospectively included. Evaluation using the visual analog scale pain score, American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value, Hospital Anxiety and Depression Scale (HADS), and Abbreviated scale of World Health Organization Quality of Life (WHOQOL-BREF) was performed before surgery and at 1.5, 3, 6, and 12 months after surgery.

RESULTS

The mean visual analog scale pain score, HADS-depression score, and HADS-anxiety score showed a significant decrease from 6.6, 13.3, and 13.9 before surgery to 1.5, 3.9, and 3.7 after 12 months after surgery, respectively (all P < .001). The mean ASES score, WHOQOL-BREF score, and subjective shoulder value showed a significant improvement from 28.5, 32.3, and 23.6% to 81.3, 79.1, and 78.4%, respectively (all P < .001). All outcome measurements showed a significant improvement from 6 weeks after RSA. In multivariate analysis, age was an independent predictor of the final ASES score and WHOQOL-BREF score (P = .037 and .004, respectively).

CONCLUSION

This study showed a sequential improvement of emotional status and quality of life as well as functional recovery with pain relief from 6 weeks after RSA in patients with rotator cuff insufficiency. Especially, younger patients had better postoperative functional ability and quality of life. These findings suggest that RSA for rotator cuff insufficiency provides a rapid improvement of emotional status and quality of life.

Postoperative acromiohumeral interval affects shoulder range of motions following reverse total shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) improves function and reduces pain for patients with complex shoulder problems. However, there is a lack of literature regarding the association of radiographic parameters on clinical outcomes after RTSA. The aim of this study was to analyze various radiographic parameters that may be predictive of clinical outcomes after RTSA. A total of 55 patients treated with RTSA were enrolled. Shoulder radiographic parameters were used for measurement of critical shoulder angle, acromial index, acromiohumeral interval, deltoid lever arm, acromial angulation, glenoid version, and acromial height. Preoperative and postoperative clinical outcomes were evaluated at a minimum 2-year follow-up. An analysis of correlations between radiographic parameters and clinical outcomes was then performed. A significant change in critical shoulder angle, acromiohumeral interval, and deltoid lever arm was observed between preoperative and postoperative radiographic measurements. A significant improvement was observed in all clinical outcomes and range of motions from preoperative to postoperative (all p < 0.001). A negative correlation of postoperative acromiohumeral interval with forward flexion (r = - 0.270; p = 0.046), external rotation (r = - 0.421; p = 0.001), and internal rotation (r = 0.275; p = 0.042) was observed at final follow-up. In addition, postoperative acromiohumeral interval less than 29 mm had an 86% positive predictive value of obtaining 130° of forward flexion and 45° of external rotation. It was found that postoperative acromiohumeral interval showed an association with active range of motion in patients who underwent RTSA. In particular, excessive distalization reduced forward flexion and external rotation motion of the shoulder in patients treated with RTSA.

Short-term outcomes of two-stage reverse total shoulder arthroplasty with antibiotic-loaded cement spacer for shoulder infection

Background

The purpose of our study was to investigate short-term outcomes of two-stage reverse total shoulder arthroplasty (RTSA) with an antibiotic-loaded cement spacer for shoulder infection.

Methods

Eleven patients with shoulder infection were treated by two-stage RTSA following temporary antibiotic-loaded cement spacer. Of the 11 shoulders, nine had pyogenic arthritis combined with complex conditions such as recurrent infection, extensive osteomyelitis, osteoarthritis, or massive rotator cuff tear and two had periprosthetic joint infection (PJI). The mean follow-up period was 29.9 months (range, 12–48 months) after RTSA. Clinical and radiographic outcomes were evaluated using the visual analog scale (VAS) score for pain, American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value (SSV), and serial plain radiographs.

Results

The mean time from antibiotic-loaded cement spacer to RTSA was 9.2 months (range, 1–35 months). All patients had no clinical and radiographic signs of recurrent infection at final follow-up. The mean final VAS score, ASES score, and SSV were significantly improved from 4.5, 38.6, and 29.1% before RTSA to 1.7, 75.1, and 75.9% at final follow-up, respectively. The mean forward flexion, abduction, external rotation, and internal rotation were improved from 50.0°, 50.9°, 17.7°, and sacrum level before RTSA to 127.3°, 110.0°, 51.8°, and L2 level at final follow-up, respectively.

Conclusions

Two-stage RTSA with antibiotic-loaded cement spacer yields satisfactory short-term clinical and radiographic outcomes. In patients with pyogenic arthritis combined with complex conditions or PJI, two-stage RTSA with an antibiotic-loaded cement spacer would be a successful approach to eradicate infection and to improve function with pain relief.

Patient-specific instrumentation improves the reproducibility of preoperative planning for the positioning of baseplate components with reverse total shoulder arthroplasty: a comparative clinical study in 39 patients

BACKGROUND

The application of patient-specific instrumentation (PSI) for reverse total shoulder replacement has been rapidly increasing, which could reduce errors in implant positioning. Although PSI theoretically holds promise, evidence of the accuracy and reliability of PSI in shoulder replacement surgery is limited.

METHODS

Thirty-nine shoulders that underwent reverse total shoulder arthroplasty were included in this study and categorized into two groups: the conventional (n = 20) and PSI (n = 19) groups. Screw (length and angle) and baseplate (version, inclination, translation, and rotation) positioning were calculated based on postoperative computed tomography images using a three-dimensional measurement tool. The difference between the values of the preoperative target and postoperative measurement was calculated to evaluate the reproducibility of preoperative planning. Screw involvement in the suprascapular and spinoglenoid notches was assessed. Thus, the correlation between the position of the baseplate and the screws was assessed.

RESULTS

The mean differences between the planned length and angle (anteroposterior and superoinferior angles) and postoperative measurement in the PSI group were significantly smaller than those in the conventional group. Similarly, the mean difference in baseplate rotation between the planned and postoperative measurements in the PSI group was significantly lower than that in the conventional group (4.5° vs 10.6°; P < .001). The spinoglenoid notch was involved in 10 cases in the conventional group and 2 cases in the PSI group, and this difference was significant (P = .014). Overall, the mean difference between the preoperative and postoperative version, inferior inclination, and rotation values for the baseplate position was significantly correlated with the values for screw position (length and angle).

CONCLUSIONS

PSI improves the reproducibility of preoperative planning for baseplate and screw positioning and reduces the risk of neurovascular injury in reverse total shoulder arthroplasty.

Humeral stem with low filling ratio reduces stress shielding in primary reverse shoulder arthroplasty

PURPOSE

Some patients show severe humeral bone stress shielding even one year after press-fit humeral stem, which can be a risk factor for implant durability. This study compared humeral stress shielding and clinical outcomes between high and low filling ratio (HFR and LFR) stems in primary reverse shoulder arthroplasty (RSA).

METHODS

From 2015 to 2020, 104 patients who underwent RSA with a non-cemented standard-length humeral stem were examined. The humeral stems included large press-fit stems (HFR group, 53 patients) or small non-press-fit stems with autogenous cancellous bone grafting (LFR group, 51 patients). The radiologic and clinical outcomes were compared between the groups one year post-operatively.

RESULTS

One patient in the LFR group with early infectious dislocation was excluded from the 1-one year evaluation. No stress shielding was observed in 27/50 (54.0%) and 5/53 (9.4%) of patients in the LFR and HFR groups, while 3/50 (6%) and 19/53 (35.8%) patients showed high-stress shielding, respectively. However, the stem alignment change, subsidence, complications and evidence of loosening did not differ between the groups. The final range-of-motion and functional scores were significantly poorer in the LFR group than those in the HFR group, although the difference was minimal.

CONCLUSION

Even at one year follow-up, patients receiving LFR stems with autogenous bone grafting had significantly less humeral stress shielding compared to patients with HFR stem with press-fit in primary RSA, without compromising stem stability.

Clinical outcomes of reverse total shoulder arthroplasty for elective indications versus acute 3- and 4-part proximal humeral fractures: a systematic review and meta-analysis

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) has continued to increase in clinical utility and popularity as an effective treatment for cuff tear arthropathy (CTA), irreparable rotator cuff tears (RCTs), osteoarthritis, and acute 3- and 4-part proximal humeral fractures. Performing RTSA for acute proximal humeral fractures presents the unique challenges of tuberosity management, bone loss, and instability compared with elective indications such as CTA or irreparable RCTs. The purpose of this study was to compare the clinical outcomes, active range of motion (ROM), radiographic outcomes, and complications between patients undergoing elective RTSA (RTSA-E) and those undergoing RTSA for fracture (RTSA-F).

METHODS

A systematic review of the literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We queried 3 electronic databases (Embase, Cochrane, and PubMed) using the search term "reverse" AND "shoulder" AND "arthroplasty." Studies investigating the clinical outcomes of RTSA for traumatic and/or elective indications were included. Studies were excluded if they included RTSA performed for fracture sequelae, inflammatory arthritis, post-traumatic osteoarthritis, or avascular necrosis. Data collected included patient demographic characteristics, subjective outcome measurements, ROM, and complications. The pooled means and proportions along with their 95% confidence intervals were generated by a random-effects model that incorporated the between-study variations in weighting.

RESULTS

A total of 134 studies (11,651 shoulders) investigating the clinical outcomes of RTSA-E patients and 66 studies (3117 shoulders) investigating RTSA-F patients were included in this systematic review. Analysis of patient-reported outcomes demonstrated that RTSA-F patients experienced significantly lower Constant scores than RTSA-E patients; however, relative Constant scores, Simple Shoulder Test scores, Disabilities of the Arm, Shoulder and Hand scores, American Shoulder and Elbow Surgeons scores, and visual analog scale pain scores were similar. RTSA-F patients also had significantly lower forward elevation, abduction, and external rotation. RTSA-F patients experienced tuberosity complications at a significantly higher rate than RTSA-E patients (25.9% vs. 4.1%). There was no significant difference between the 2 groups in terms of other complications such as heterotopic ossification, radiographic loosening, revision, nerve injury, postoperative stiffness, infection, dislocation, and component loosening.

DISCUSSION

RTSA performed for acute 3- and 4-part proximal humeral fractures yields overall worse clinical outcomes and active ROM compared with RTSA performed for elective indications including CTA, massive irreparable RCTs, and osteoarthritis with deformity. Tuberosity healing may be a major contributing factor to the difference in clinical outcomes. In the setting of RTSA-F, patient and surgeon expectations may need to be tempered and appropriate measures undertaken to optimize tuberosity healing.