Reverse shoulder arthroplasty in obese patients: analysis of functionality in the medium-term

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.

Relationship between the preoperative grip strength and postoperative shoulder strength of patients treated via reverse shoulder arthroplasty

BACKGROUND

Systemic disorders including diabetes mellitus, obesity, and depression affect the outcomes of reverse shoulder arthroplasty (RSA). Sarcopenia (a general skeletal muscle disorder) is common in elderly people, but its effect on patients after RSA is not clear. We hypothesized that the preoperative sarcopenia indices of grip strength and general skeletal muscle mass would correlate with the clinical outcomes of RSA.

METHODS

Grip strength and general skeletal muscle mass were measured in patients scheduled (between 2016 and 2021) for primary RSA to treat cuff tear arthropathy, an unrepairable cuff tear, or osteoarthritis with a large cuff tear. Before surgery, grip strength was measured using a hydraulic dynamometer and general skeletal muscle mass was calculated from the appendicular relative skeletal muscle mass index (aRSMI) using dual-energy X-ray absorptiometry. In all, 58 patients were included; the minimal follow-up duration was 12 months. The postoperative clinical results (pain, active range of motion, shoulder strength, and functional scores) were evaluated during scheduled outpatient visits. We calculated correlations between the preoperative sarcopenia indices, and the clinical results at the final follow-up.

RESULTS

The mean preoperative grip strength and aRSMI were 21.6 ± 4.0 kg and 5.98 ± 0.84 kg/m2 in females and 30.6 ± 7.5 kg and 7.21 ± 0.94 kg/m2 in males, respectively; the grip strength and aRSMI were not associated with each other (P = .083). Ten females (25%) and 10 males (56%) met the criteria for sarcopenia. The postoperative abduction shoulder strength and Constant-Murley shoulder score increased significantly with higher preoperative grip strength (R = 0.420 and P = .001; and R = 0.497 and P < .001, respectively) and the American Shoulder and Elbow Surgeons score was related to the preoperative aRSMI (R = 0.320, P = .039).

CONCLUSIONS

The shoulder strength and functional score after RSA correlated positively with the preoperative grip strength. Measuring grip strength before RSA allows the surgeon to predict shoulder strength after RSA.

Obesity and Reverse Total Shoulder Arthroplasty

PURPOSE OF REVIEW

Rates of obesity and reverse total shoulder arthroplasty (rTSA) in the USA have both escalated with time. Obese patients experience arthritis at higher rates than normal weight patients; therefore, these numbers go hand in hand. Obesity has been correlated with health comorbidities such as anxiety, cardiovascular disease, diabetes, and metabolic syndrome as well as poorer outcomes and higher complication rates following lower extremity arthroplasty. The current review investigates these comorbidities as they relate to obese patients undergoing rTSA.

RECENT FINDINGS

Functional outcomes are similar to normal weight counterparts. Although longer operative times and a large soft tissue envelope would intuitively predispose these patients to higher risk for infection or other complications, this has not been reliably demonstrated. Technical considerations and awareness of potential risks in the obese patient demographic may aid the surgeon in preoperative planning and counseling of their patient. Obese patients undergoing rTSA have been shown to have higher risks specifically for infection, revision, and medical complications; however, this has not been consistently demonstrated in the single surgeon series where, more often, no difference in these metrics has been found. Outcomes measures and satisfaction are reliably improved, even when considering superobese patients, and majority of studies find their improvements and absolute values to be in line with their normal weight counterparts. Thus, rTSA does not seem to carry the same level of adverse risk associated with lower joint arthroplasty but potential for higher risk still bears consideration when counseling obese patients. Attention to factors that may negatively affect prosthesis positioning may optimize retention rates and limit early failure.

Effects of obesity on clinical and functional outcomes following anatomic and reverse total shoulder arthroplasty

BACKGROUND

Limited data exist regarding the clinical and functional outcomes following primary total shoulder arthroplasty in obese patients. The purpose of this study is to determine the effects of obesity on the clinical and functional outcomes following primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) in a large patient population with mid-term follow-up.

METHODS

Patients in a multi-institutional shoulder registry receiving either primary aTSA (n = 1520) or rTSA (n = 2054) from 2004 to 2018 with a minimum follow-up period of 2 years were studied. All patients received the same single-platform shoulder prosthesis. Study groups were assigned based on implant type (anatomic or reverse), and further stratification was based on patient body mass index (BMI), with obese patients having a BMI ≥ 30 and non-obese patients having a BMI < 30. Patients were evaluated and scored preoperatively and at latest follow-up by use of 5 scoring metrics and range of motion (ROM).

RESULTS

The mean follow-up period was 5 years (range, 2-14 years). Obese patients comprised 41% of the aTSA group and 35% of the rTSA group. Significant postoperative improvements in visual analog scale pain scores, ROM, and all 5 scoring metrics occurred in both obese and non-obese patients (P < .05). Obese patients in both groups reported higher preoperative and postoperative visual analog scale pain scores and less preoperative and postoperative ROM compared with non-obese patients. Compared with non-obese patients, obese patients receiving aTSA reported significantly worse postoperative Simple Shoulder Test, Constant-Murley, American Shoulder and Elbow Surgeons, University of California, Los Angeles, and Shoulder Pain and Disability Index scores compared with non-obese patients, and those receiving rTSA reported significantly worse American Shoulder and Elbow Surgeons and Shoulder Pain and Disability Index scores (all P < .05). However, these differences did not exceed the minimal clinically important difference or substantial clinical benefit criteria. Radiographic analysis showed that in the rTSA group, obese patients had significantly less postoperative scapular notching and a lower scapular notching grade compared with non-obese patients (P < .05).

DISCUSSION

Both non-obese and obese patients can expect clinically significant improvements in pain, motion, and functional outcome scores following both aTSA and rTSA. Obese patients reported significantly more postoperative pain, lower outcome scores, and less ROM compared with non-obese patients after both aTSA and rTSA at a mean follow-up of 5 years. However, statistically significant differences were not found to be clinically significant with respect to established minimal clinically important difference and substantial clinical benefit criteria. Therefore, obese and non-obese patients experience similar clinical outcomes following total shoulder arthroplasty, regardless of BMI. However, obese patients have more comorbidities, greater intraoperative blood loss, and less scapular notching compared with non-obese patients.

Dislocation after reverse total shoulder arthroplasty using contemporary medialized modular systems. Can we still consider it such a frequent complication?

INTRODUCTION

Improvement in reverse total shoulder arthroplasty (RTSA) prosthesis and technique has reduced the initially high complication and revision rates associated with this implant. However, instability continues to be a leading cause of reoperation after RTSA, being related in previous studies with medialized designs. The aim of this study was to determine the dislocation rate with the employment of two medialized modular systems of RTSA in our institution.

MATERIALS AND METHODS

A retrospective review of two different modular systems of RTSA (SMR Modular Shoulder System and Delta XTEND Reverse Shoulder) was performed between 2009 and 2017 with a minimum 3-year follow-up. Baseline demographic, clinical (Constant, ASES and ROM), and radiographic data were collected. Characteristics of postoperative instability cases were also evaluated.

RESULTS

237 primary RTSA (41% SMR/59% Delta) and 34 revision RTSA (44% SMR/56% Delta) with a mean follow-up of 75.6 ± 5.2 months (79.2 SMR/86.3 Delta, p = .586) were included in the present study. Indications for primary RTSA were osteoarthritis, rotator cuff tear arthropathy and massive irreparable rotator cuff tear (64%), acute fracture (32%), and fracture sequelae (4%). Subscapularis tendon was always repaired in degenerative pathology and tuberosities reattached in traumatic cases. The mean age of the global series was 76.5 ± 5.3 years (75.8 SMR/78.6 Delta, p = .104) with a mean Constant/ASES score at final follow-up of 68.5 ± 4.3/72.9 ± 20.3 (71/68 SMR and 69/74 Delta, p = .653 and .642). Only 2 patients (one acute fracture and one fracture sequelae) suffered an early postoperative anterior dislocation (before 3 months) which represents a rate of .84% in primary cases and .73% including revision surgery. Closed reduction manoeuvres were not successful, and both patients required revision surgery. At the end follow-up, both were stable and had no further dislocations.

CONCLUSION

The dislocation rate after RTSA with the employment of two contemporary modular systems with a medialized centre of rotation is extremely low, especially when compared with the previously published series with the original Grammont design. Acute fracture and fracture sequelae were the main diagnoses associated with this instability. The reasons for the low dislocation rate are multifactorial, but the improvement in the baseplate position according to the more recent standards of "ideal position" and technical aspects such as subscapularis repair or tuberosity reattachment in fractures probably play an important role in this aspect.

Decreased complication profile and improved clinical outcomes of primary reverse total shoulder arthroplasty after 2010: A systematic review

The purpose of this review was to update the complication profile of reverse total shoulder arthroplasty (rTSA) post-2010, given greater procedural familiarity, improved learning curves, enhanced implant designs, and increased attention to the nuances of patient selection. Three electronic databases were searched and screened in duplicate from 1 January 2010 to 16 December 2018 based on predetermined criteria. Twenty-two studies examining 1455 patients (26% male; mean age: 73.4 ± 3.6; mean follow-up: 23.4 ± 14.3 months) were reviewed. Post-operative motion ranged a mean 122.4° ± 11.5° flexion, 109° ± 19.4° abduction, and 33° ± 11.2°/41° ± 5° external/internal rotation. Post-operative mean Constant score was 58.9 ± 10.1, American Shoulder Elbow Surgeon score was 73.4 ± 6.1, Simple Shoulder Test score was 63.5 ± 6.5, and a Visual Analog Scale pain score was 1.6 ± 0.9. The overall complication rate was 18.2% and major complication rate was 15.4%. Compared to pre-2010, the overall complication rate of 18.2% is lower than previous rates of 19%-68%, with the rate of "major" complications dropping three-fold from 15.4% to 4.6%. The data suggest that rTSA is a safe and efficacious alternative to aTSA and HA, and the "stale" nature of previous complication profiles are points fundamental to perioperative discussions surrounding rTSA.

The modern reverse shoulder arthroplasty and an updated systematic review for each complication: part I

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this 2-part study was to systematically review each of the most common complications of RSA, limiting each search to publications in 2010 or later. In this part (part I), we examined (1) scapular notching (SN), (2) periprosthetic infection (PJI), (3) mechanical failure (glenoid or humeral component), and (4) neurologic injury (NI).

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Overall, 113 studies on SN, 62 on PJI, 34 on mechanical failure, and 48 on NI were included in our reviews. Univariate analysis was performed with the χ² or Fisher exact test.

Results

The Grammont design had a higher SN rate vs. all other designs combined (42.5% vs. 12.3%, P < .001). The onlay humeral design had a lower rate than the lateralized glenoid design (10.5% vs. 14.8%, P < .001). The PJI rate was 2.4% for primary RSA and 2.6% for revision RSA. The incidence of glenoid and humeral component loosening was 2.3% and 1.4%, respectively. The Grammont design had an increased NI rate vs. all other designs combined (0.9% vs. 0.1%, P = .04).

Conclusions

Focused systematic reviews of the recent literature with a large volume of RSAs demonstrate that with the use of non-Grammont modern prosthesis designs, complications including SN, PJI, glenoid component loosening, and NI are significantly reduced compared with previous studies. As the indications for RSA continue to expand, it is imperative to accurately track the rates and types of complications to justify its cost and increased indications.

Safety and Effectiveness of Shoulder Arthroplasties in Spain: A Systematic Review

The effectiveness and safety of shoulder arthroplasties in the general context of a Spanish patient population remains unclear. The aim of this study was to ascertain both the effectiveness and safety of primary shoulder arthroplasties and the prosthesis types used in Spain. A systematic review of all the available literature evaluating the effectiveness and safety of primary shoulder arthroplasties in Spain was performed. A narrative synthesis was performed, and evidence tables were created in four dimensions: study design, arthroplasty characteristics, safety, and effectiveness. Orthopaedic Data Evaluation Panel (ODEP) scores were used to evaluate prosthesis types. Twenty-one studies were selected that included a total of 1293 arthroplasties. The most common indication was fractures, while the prosthesis most frequently used was the Delta Xtend (ODEP 10A). The most common complication was scapular notching. Prosthesis revision rate was approximately 6% for follow-ups between 12 and 79 months. In addition, significant improvements were observed in the Constant-Murley test score after the intervention. Currently in Spain, shoulder arthroplasty can be considered a safe and effective procedure with functional recovery and pain reduction for eligible patients with humeral fracture, rotator cuff arthropathy, fracture sequelae and malunion of the proximal humerus, and degenerative disease. Future longitudinal research and population-based studies could serve to confirm these results and identify points of improvement.

Patient-reported outcomes of reverse total shoulder arthroplasty: a comparative risk factor analysis of improved versus unimproved cases

Background

The purpose of this study was to compare characteristics of patients who reported to be subjectively unimproved vs. improved after reverse total shoulder arthroplasty.

Methods

Data were derived from a prospective registry of patients who underwent reverse total shoulder arthroplasty with a minimum 2-year follow-up. Patients were asked to rate their subjective satisfaction and then divided into those who were unchanged or worse (unimproved group [UG]) vs. better or much better (improved group [IG]). The groups were compared for differences in demographic characteristics, preoperative factors, functional outcomes, and complications.

Results

There were 1425 patients in the IG and 134 patients in the UG. Patients in the IG were more likely to have a diagnosis of osteoarthritis. Patients in the UG were more likely to have coronary artery disease and diabetes and to have undergone prior surgery. No differences in implant configuration were found between groups. Preoperative measures for patients in the UG were worse for pain and function but not for range of motion. The outcomes in patients in the UG were worse for all postoperative measures, as well as for preoperative-to-postoperative improvement. Of the patients in the UG, 48% continued to have moderate to severe pain postoperatively. The complication rate was significantly higher in the UG.

Discussion

Up to 8.5% of patients rate themselves as unimproved after surgery. These patients are more likely to have certain comorbidities and to have undergone prior surgery. Although outcomes were significantly worse for all measures in the UG, improvement occurred in all measures despite patients subjectively being worse or unchanged. Residual pain and difficulty sleeping play a substantial role in subjective assessment of overall outcome.