Deltoid fatigue: a longitudinal assessment of reverse shoulder arthroplasty over time

Pain relief survivorship: a comparison of Exactech Equinoxe anatomic and reverse total shoulder arthroplasty for primary osteoarthritis

BACKGROUND

Pain relief plays a major deterministic role when assessing postoperative patient satisfaction; however, whether anatomic total shoulder arthroplasty (aTSA) or reverse total shoulder arthroplasty (rTSA) provides the most durable pain relief has not been studied. The purpose of this study was to evaluate the durability of pain relief after aTSA compared with rTSA in patients undergoing surgery for rotator cuff-intact glenohumeral osteoarthritis (RCI-GHOA).

METHODS

A retrospective review of a multicenter shoulder arthroplasty database (Exactech Equinoxe) was performed. We included 1848 aTSAs and 1464 rTSAs performed for RCI-GHOA between 2007 and 2023. Pain after surgery was assessed postoperatively at 3 months, 6 months, and yearly thereafter. Average postoperative pain on a daily basis and pain at worst were compared between aTSA and rTSA up to 8 years postoperatively. Kaplan-Meier survivorship analysis for pain relief maintenance was performed to compare the maintenance of clinically relevant pain relief defined as pain scores that achieved the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS). Maintenance of favorable patient satisfaction over time was also evaluated. Multivariable cox regression was performed to determine whether the type of prosthesis (aTSA vs. rTSA) was independently associated with pain recurrence.

RESULTS

Maintenance of achievement of the MCID and SCB for both daily pain and pain at worst as well as favorable patient satisfaction was similar between aTSAs and rTSAs. However, aTSA had longer maintenance of average daily pain below the PASS compared with rTSA (P = .024). This was confirmed on multivariable cox regression analysis, which found that rTSAs had a 34% greater likelihood of recurrence of postoperative average daily pain exceeding the PASS (visual analog scale score rating 1/10) compared with aTSAs.

CONCLUSION

Patients who undergo either aTSA or rTSA for RCI-GHOA and achieve initial pain relief postoperatively can expect to maintain their clinically relevant pain improvement at similar rates up to 8 years postoperatively. However, recurrence of low levels of daily pain was significantly higher after rTSA.

Prosthetic treatment of proximal humerus fractures in the elderly

The Section for Skeletal Trauma and Sports Injuries of the European Society for Trauma and Emergency Surgery (ESTES) has reached a consensus among European countries in the treatment of proximal humerus fractures in a working group. As a result the ESTES recommendations on proximal humerus fractures in the elderly were published in 2021. The various treatment options and algorithms for this are now described in more detail and the procedures were explained in several related specialist articles. The recommendations include conservative and four possible surgical treatment options (ORIF, nailing, hemi- and total inverse arthroplasty). This article deals with hemi- and total inverse arthroplasty. Reverse total shoulder arthroplasty (RTSA) has emerged as a key treatment for complex proximal humerus fractures in elderly patients. It offers significant advantages in restoring function, alleviating pain, and providing durable outcomes compared to alternative approaches. Despite challenges related to implant complications and surgical expertise, ongoing advancements in technology and techniques continue to improve its effectiveness. With the rising incidence of complex fractures, RTSA is expected to play an increasingly vital role in maintaining the quality of life in aging populations.

Influence of preoperative rotational shoulder stiffness on rate of motion restoration after anatomic and reverse total shoulder arthroplasty for glenohumeral osteoarthritis with an intact rotator cuff

BACKGROUND

A subset of patients undergoing anatomic and reverse total shoulder arthroplasty (aTSA and rTSA) lag behind their peers in regaining overhead range of motion (ROM) after surgery. The primary purpose of this study was to compare the rate of recovery of ROM after aTSA and rTSA performed in stiff (preoperative passive external rotation [ER] ≤0 °) versus non-stiff (preoperative passive ER >0°) shoulders with RCI-GHOA.

HYPOTHESIS

We hypothesized that preoperatively stiff shoulders (preoperative passive ER ≤0 °) would have slower recovery in ROM postoperatively with lower postoperative motion compared to non-stiff shoulders.

METHODS AND MATERIALS

A retrospective review of a multi-institution shoulder arthroplasty database was performed between 2001 and 2021. We identified 1,164 aTSAs and 539 rTSAs performed for RCI-GHOA with a minimum of 2-year clinical follow-up along with follow-up between 3-6 months and a third visit at any other time point. Primarily, the rate of recovery in ROM and time to maximum ROM was evaluated. Secondarily, we assessed six outcome scores and the influence of subscapularis repair during rTSA. Recovery in each outcome was modeled using continuous two-phase segmented linear regression models with random effects. Rate of recovery was defined as the slope of the first segment. Patients were considered to have recovered after surgery at the timepoint corresponding to the inflection point between piecewise segments.

RESULTS

Of the 1,164 aTSAs and 539 rTSAs included, 172 aTSAs (15%) and 80 rTSAs (15%) were stiff preoperatively, respectively. Compared to preoperatively stiff aTSAs, non-stiff aTSAs regained ER, abduction, internal rotation (IR), and forward elevation (FE) faster over a shorter duration. Similarly, non-stiff rTSAs regained ER, abduction, and FE faster and over a shorter duration compared to stiff rTSAs, but regained IR more slowly over a longer duration. Stiff rTSAs performed with subscapularis repair did not have any appreciable gain in ER after the immediate postoperative period. Although non-stiff and stiff rTSAs performed without subscapularis repair regained ER at a similar rate (4.4 vs. 4.2 °/month), stiff rTSAs continued to regain ER 1.9-times longer (11.9 vs. 6.4 months). When the subscapularis was repaired, non-stiff rTSAs regained abduction and IR faster over a short duration compared to stiff rTSAs.

CONCLUSIONS

Preoperative stiffness is associated with slower recovery of active ROM over a longer duration in patients undergoing shoulder arthroplasty for RCI-GHOA.

LEVEL OF EVIDENCE

III; Retrospective Cohort Comparison; Treatment Study.

The Evolution of Reverse Shoulder Arthroplasty: A Review of Complications and the Rising Concern of Overuse

Reverse shoulder arthroplasty (RSA) was initially developed to manage cuff tear arthropathy in elderly patients. It has since become increasingly popular due to its ability to provide pain relief, enhance stability, and improve function in various complex shoulder pathologies. This review examines the evolution of RSA, including its expanded indications for use, complications, and the rising concern of potential overuse. While RSA has shown significant benefits in selected cases, its growing application in younger and more active patients raises questions about long-term outcomes and durability. Complications such as instability, infection, baseplate failure, and scapular notching remain substantial challenges, particularly in revision cases. The article emphasises the need for cautious patient selection and evidence-based practice to avoid overuse and ensure optimal patient outcomes. Future high-quality research with extended follow-up is essential to better understand RSA's long-term efficacy and safety, particularly in diverse and younger patient populations.

The effect of smoking on outcomes of reverse total shoulder arthroplasty

BACKGROUND

The effect of smoking status on clinical outcomes in reverse total shoulder arthroplasty (rTSA) has not been thoroughly characterized. We sought to compare pain and functional outcomes, complications, and revision-free survivorship between current smokers, former smokers, and nonsmokers undergoing primary rTSA.

METHODS

We retrospectively reviewed a prospectively collected shoulder arthroplasty database from 2004-2020 to identify patients who underwent primary rTSA. Three cohorts were created based on smoking status: current smokers, former smokers, and nonsmokers. Outcome scores (Shoulder Pain and Disability Index [SPADI], Simple Shoulder Test [SST], American Shoulder and Elbow Surgeons [ASES], University of California, Los Angeles [UCLA], and Constant), range of motion (external rotation, forward elevation, abduction, and internal rotation), and shoulder strength (external rotation and forward elevation) evaluated at 2-4-year follow-up were compared between cohorts. The incidence of complication and revision-free implant survivorship were evaluated.

RESULTS

We included 676 primary rTSAs, including 38 current smokers (44 ± 47 pack-years), 84 former smokers who quit on average 20 ± 14 years (range: 0.5-57 years) prior to surgery (38 ± 32 pack-years), and 544 nonsmokers. At 2-4-year follow-up, current smokers had less favorable SPADI, SST, ASES scores, UCLA scores, and Constant scores compared to former smokers and nonsmokers. On multivariable analysis, current smokers had less favorable SPADI, SST, ASES score, UCLA score, and Constant score compared to nonsmokers. There were no significant differences between cohorts in complication rate and revision-free survivorship.

CONCLUSION

Our data showed that current smokers may have poorer functional outcomes after rTSA compared to former smokers and nonsmokers, despite the incidence of complications and revision surgery not differing significantly between cohorts.

The impact of the underlying pathology and previous surgery on the long-term functional outcomes of the Delta Xtend reverse total shoulder arthroplasty: a prospective cohort study with a minimum follow-up of 11 years

BACKGROUND

Reverse total shoulder arthroplasty (rTSA) is a successful treatment option for rotator cuff tear arthropathy (CTA). Since its introduction, the range of indications has been expanded while implant designs have been enhanced. The purpose of this study is to evaluate the long-term clinical, radiographic, and patient-reported outcomes of the Delta Xtend rTSA.

MATERIALS AND METHODS

In this prospective cohort study, 108 consecutive patients who underwent implantation of rTSA using the DePuy Delta Xtend in 2008 were included. Patients were divided into 4 indication groups: CTA (60%), revision shoulder arthroplasty (15%), fracture sequelae (19%), and postinfectious arthropathy (6%). Clinical examination and radiographic follow-up were performed after 5 years and at long term with a minimum follow-up of 11 years.

RESULTS

Forty three patients were eligible for follow-up with a median follow-up period of 12.5 years (range: 11.5-12.6 years, response rate 79%). The preoperative Constant score (CS) was 19 (9-24), and the CS at follow-up was 56 (41-64) with a significant increase between implantation and latest follow-up (P < .001). No significant difference of the CS at follow-up was reported between the 4 groups. Between the mid-term follow-up and the latest follow-up, a significant decrease of the CS of 10 (2-14) was observed (P = .004); however, no significant difference in the age-correlated and sex-correlated CS was reported (P = .13). Patients who underwent previous surgery before the index arthroplasty (51 [35-62]) had a significantly lower CS than patients without previous surgery (63 [58-66], P = .032). Patients with revision arthroplasty had a significantly lower range of motion at long-term follow-up than patients with CTA (P = .013). Implant survival was 95.3% after 11 years. Patients with fracture sequelae had a significantly higher risk for revision than patients with CTA (P = .04). Implant survival without revision for any complication was 89.7%; the overall complication rate was 12.5%.

CONCLUSION

This study demonstrated favorable long-term outcomes of rTSA and a satisfactory survival rate using the Delta Xtend system. However, a significant decline of the functional outcome was observed since the mid-term follow-up. For indications other than CTA, the functional results are inferior, and the risk for revision is higher. Previous shoulder surgery prior to the index arthroplasty leads to a worse functional outcome and a higher risk of reoperation due to any complication.

Anatomic Versus Reverse Total Shoulder Arthroplasty for Primary Osteoarthritis With an Intact Rotator Cuff: A Midterm Comparison of Early Top Performers

BACKGROUND

Several surgeons state that their best anatomic total shoulder arthroplasty (aTSA) outperforms their best reverse total shoulder arthroplasty (rTSA) when performed for rotator cuff-intact glenohumeral osteoarthritis. We identified the top-performing aTSAs and rTSAs at short-term follow-up and compared their clinical performance at midterm follow-up to validate this common claim.

METHODS

A retrospective review of a multicenter shoulder arthroplasty database was conducted. All shoulders undergoing primary aTSA or rTSA for rotator cuff-intact glenohumeral osteoarthritis between 2007 and 2020 were reviewed. Shoulders with a follow-up clinical visit between 2 and 3 years and a clinical follow-up of minimum 5 years were included. Two separate cohorts were identified: patients with a top 20% (1) American Shoulder and Elbow Surgeons (ASES) score and (2) Shoulder Arthroplasty Smart (SAS) score at 2 to 3 years of follow-up. Clinical outcomes including range of motion, outcome scores, and rates of complications and revision surgeries were compared at minimum 5-year follow-up.

RESULTS

The ASES score cohort comprised 185 aTSAs (mean age 67 years, 42% female) and 49 rTSAs (mean age 72 years, 45% female). The SAS score cohort comprised 145 aTSAs (mean age 67 years, 59% female) and 42 rTSAs (mean age 71 years, 57% female). Active external rotation (ER) was greater after aTSA at midterm follow-up in both ASES and SAS score cohorts; however, preoperative to postoperative improvement was equivalent. Postoperative ER and SAS scores were greater after aTSA in both cohorts ( P < 0.05); however, no other significant differences in any preoperative or postoperative clinical outcomes were present ( P > 0.05), and patients achieved the minimal clinically important difference and substantial clinical benefit at similar rates for all outcomes. No difference was found in the incidence of complications and revision surgeries between top-performing aTSAs and rTSAs.

CONCLUSION

Among top-performing shoulder arthroplasties at early follow-up, aTSA does not appear to outperform rTSA, except superior ER at midterm follow-up.

LEVEL OF EVIDENCE

Retrospective comparative cohort study, Level Ⅲ.

Do preoperative scapular fractures affect long-term outcomes after reverse shoulder arthroplasty?

BACKGROUND

Postoperative scapular stress fractures (SSFs) are a formidable problem after reverse shoulder arthroplasty (RSA). Less is known about patients who have these fractures preoperatively. The primary aim of this study was to examine postoperative satisfaction in patients undergoing primary RSA who have preoperative SSF and compared to a matched cohort without preoperative fracture. The secondary aim was to examine the differences in patient-reported outcomes between and within study cohorts.

METHODS

A retrospective chart review of primary RSAs performed by a single surgeon from 2000 to 2020 was conducted. Patients diagnosed with cuff tear arthropathy (CTA), massive cuff tear (MCT), or rheumatoid arthritis (RA) were included. Five hundred twenty-five shoulders met inclusion criteria. Fractures identified on preoperative computed tomography scans were divided into 3 groups: (1) os acromiale, (2) multifragments (MFs), and (3) Levy types. Seventy-two shoulders had an occurrence of SSF. The remaining 453 shoulders were separated into a nonfractured cohort. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and visual analog scale (VAS) scores were compared pre- and postoperatively in the total fracture group and the nonfractured group cohort. The multifragment subgroup was also compared to the pooled Os/Levy subgroup.

RESULTS

The total incidence of SSF in all shoulders was 13.7%. There was a difference in satisfaction scores at all time points between the nonfracture (7.9 ± 2.8) and total fracture group (5.4 ± 3.6, P < .001, at last visit). There was also a greater ASES total score in the nonfractured group vs the total fracture group at the final visit (69.4 ± 23.4 and 62.1 ± 24.2; P = .02). The MF group had worse ASES functional or VAS functional scores than the Os/Levy group at all time points: at 1 year, ASES function: MF 24.2 ± 14.5 and Os/Levy 30.7 ± 14.2 (P = .045); at 2 years, ASES function: MF 21.4 ± 14.4 and Os/Levy 35.5 ± 10.6 (P < .001); and at last follow-up, VAS function: MF 4.8 ± 2.8 and Os/Levy 6.4 ± 3.2 (P = .023).

DISCUSSION

Scapular fractures were proportionally most common in patients diagnosed with CTA (16.3%) compared with a 9.2% and 8.6% incidence in patients diagnosed with MCT and RA, respectively. Patients with preoperative SSF still see an improvement in ASES scores after RSA but do have lower satisfaction scores compared with the nonfractured cohort. The multifragment fracture group has lower functional and satisfaction scores at all postoperative time points compared with both the nonfracture and the Os/Levy fracture group.

Managing rotator cuff tear arthropathy: a role for cuff tear arthropathy hemiarthroplasty as well as reverse total shoulder arthroplasty

BACKGROUND

Disabling cuff tear arthropathy (CTA) is commonly managed with reverse shoulder arthroplasty (RSA). However, for patients with CTA having preserved active elevation, cuff tear arthropathy hemiarthroplasty (CTAH) may offer a cost-effective alternative that avoids the complications unique to RSA. We sought to determine the characteristics and outcomes of a series of patients with CTA managed with these procedures.

MATERIALS AND METHODS

We retrospectively reviewed 103 patients with CTA treated with shoulder arthroplasty, the type of which was determined by the patient's ability to actively elevate the arm. Outcome measures included the change in the Simple Shoulder Test (SST), the percent maximum improvement in SST (%MPI), and the percentage of patients exceeding the minimal clinically important difference for the change in SST and %MPI. Postoperative x-rays were evaluated to assess the positions of the center of rotation and the greater tuberosity for each implant.

RESULTS

Forty-four percent of the 103 patients were managed with CTAH while 56% were managed with RSA. Both arthroplasties resulted in clinically significant improvement. Patients having RSA improved from a mean preoperative SST score of 1.7 (interquartile range [IQR], 0.0-3.0) to a postoperative score of 6.3 (IQR, 2.3-10.0) (P < .01). Patients having CTAH improved from a preoperative SST score of 3.1 (IQR, 1.0-4.0) to a postoperative score of 7.6 (IQR, 5.0-10.) (P < .001). These improvements exceeded the minimal clinically important difference. Instability accounted for most of the RSA complications; however, it did not account for any CTAH complications. The postoperative position of the center of rotation and greater tuberosity on anteroposterior radiographs did not correlate with the clinical outcomes for either procedure.

CONCLUSION

For 103 patients with CTA, clinically significant improvement was achieved with appropriately indicated CTAH and RSA. In view of the lower cost of the CTAH implant, it may provide a cost-effective alternative to RSA for patients with retained active elevation.

Midterm outcomes of primary reverse shoulder arthroplasty: a systematic review of studies with minimum 5-year follow-up

Background

Excellent short-term outcomes after reverse shoulder arthroplasty (RSA) have been reported, but longer term outcomes in the existing literature are sparse and vary widely. The purpose of this study is to systematically assess the existing literature to quantify functional outcomes and complication rates after RSA at a minimum of five years of follow-up.

Methods

A Preferred Reporting Items for Systematic Reviews and Meta-analyses-compliant systematic literature search of the PubMed and Embase databases was undertaken. Studies reporting outcomes after primary RSA for nontrauma-related indications with a minimum of 5-year follow-up were included.

Results

Overall, 20 studies satisfied all inclusion criteria. This represented 1591 shoulders in 1556 patients (32.1% males), with a mean age of 70.2 ± 5.0 years and mean follow-up of 8.8 years, or 106.2 ± 30.1 months (60-243). At final follow-up, the mean reported Constant Murley score was 62.1 ± 5.0 (49.0-83.0). The mean adjusted Constant Murley score was 83.5 ± 12.5 (58-111.9). The mean American Shoulder and Elbow Surgeons score was 81.8 ± 4.6, while the mean subjective shoulder value was 74.6 ± 6.4. Overall, 88% of patients rated their satisfaction as either good or very good. The range of active forward flexion, abduction, external, and internal rotation were respectively, 126° ± 13°, 106° ± 11°, 22° ± 11°, and 6° ± 2°. The overall rate of revision surgery was 4.9% (0%-45.5%). Regarding complications, the rate of prosthetic joint infection was 4.3% (0%-26.7%), shoulder dislocation was 3.7% (0%-20.4%), and acromial fracture was 2.0% (0%-8.8%). At final follow-up, 30.9% of shoulders had some degree of scapular notching.

Conclusion

This systematic review shows that RSA results in high satisfaction rates, good clinical outcomes, as well as modest complication and revision rates at minimum 5-year follow-up.

Postoperative complications of reverse total shoulder arthroplasty: a multicenter study in Japan

Background

Reverse total shoulder arthroplasty (RSA) has been approved since 2014 in Japan, and the number of RSA cases has been accumulating. However, only short-to medium-term outcomes have been reported, with a small number of case series, because of its short history in Japan. This study aimed to evaluate complications after RSA in hospitals affiliated with our institute, with comparison to those in other countries.

Methods

A multicenter retrospective study was performed at 6 hospitals. In total, 615 shoulders (mean age: 75.7 ± 6.2 years; mean follow-up: 45.2 ± 19.6 months) with at least 24 months of follow-up were included in this study. The active range of motion was assessed pre-and postoperatively. The 5-year survival rate was evaluated for reoperation for any reason in 137 shoulders with at least 5 years of follow-up using Kaplan-Meier analysis. Postoperative complications were evaluated, including dislocation; prosthesis failure; deep infection; periprosthetic, acromial, scapular spine, and clavicle fractures; neurological disorders; and reoperation. Furthermore, imaging assessments, including scapular notching, prosthesis aseptic loosening, and heterotopic ossification were evaluated on postoperative radiography at the final follow-up.

Results

All range of motion parameters were significantly improved postoperatively (P < .001). The 5-year survival rate was 93.4% (95% confidence interval: 87.8%-96.5%) for reoperation. Complications occurred in 256 shoulders (42.0%), with reoperation in 45 (7.3%), acromial fracture in 24 (3.9%), neurological disorders in 17 (2.8%), deep infection in 16 (2.6%), periprosthetic fracture in 11 (1.8%), dislocation in 9 (1.5%), prosthesis failure in 9 (1.5%), clavicle fracture in 4 (0.7%), and scapular spine fracture in 2 (0.3%). Regarding imaging assessments, scapular notching was observed in 145 shoulders (23.6%), heterotopic ossification in 80 (13.0%), and prosthesis loosening in 13 (2.1%).

Conclusion

This is the first large case series to investigate the complications after RSA in Japan, and the overall frequency of complications after RSA was similar to that in other countries.

Functional outcome and CEUS-assessed deltoid muscle vitality after fracture-specific versus standard prosthetic design in reverse shoulder arthroplasty for trauma

Functional outcome after reverse-shoulder-arthroplasty (RSA) in proximal humerus fractures (PHF) depends on deltoid muscle integrity and successful reattachment of the tuberosities for best possible recovery of rotator-cuff function. In this monocentric, prospective, randomized, controlled trial we investigated whether a reverse-fracture-prosthesis (RFP) with a metaphyseal fenestrated stem achieved superior shoulder and muscle function compared to a common reverse-prosthesis (RP) design for patients with PHF. Our hypothesis was that patients with RFP may achieve a superior healing rate of the greater tuberosity (GT) compared to patients receiving RP, which translates to significantly higher clinical outcome and functional scores as well as differences in deltoid muscle microperfusion. Forty-four patients with PHF were randomized preoperatively to one of the prosthesis types in RSA between 2018 and 2020 (22 with RFP and 22 with RP) and prospectively assessed 6 months after surgery. We assessed osteointegration of the GT with radiographs 1 day and 6 months postoperatively and examined shoulder function and patient satisfaction by using established shoulder scores. A contrast-enhanced ultrasound (CEUS) examination of both shoulders was performed to quantify intramuscular blood flow and evaluate vitality of the deltoid muscle. None of the functional and psychosocial scores or radiographs and ultrasound examinations showed significant differences between the RSA designs. The constant-Murley score (p = 0.384) and active anterior-elevation-abduction, and external rotation were comparable between the RFP and RP group. Similar healing rates of the GT were observed (p = 0.655). CEUS-assessed deltoid microperfusion revealed equivalent muscle vitality for both groups (p = 0.312). Level of evidence: Level II; Randomized Controlled Trial; Treatment Study. Clinical significance: The radiographic evaluation for the investigation of the GT healing rate indicates that the proclaimed benefits of the fracture prosthesis with fenestration design might not be as great as expected.

Do patients with poor early clinical outcomes after reverse total shoulder arthroplasty ultimately improve?

BACKGROUND

Although most patients undergoing reverse total shoulder arthroplasty (rTSA) have substantial improvement in pain and function at early follow-up, improvements in pain and range of motion progress more slowly during postoperative rehabilitation in a subset of patients. The purpose of this study was to define a patient's risk of persistent shoulder dysfunction beyond the early postoperative period and identify risk factors for persistent poor performance.

METHODS

We retrospectively reviewed 292 primary rTSAs with early poor performance and a preoperative diagnosis of osteoarthritis, cuff tear arthropathy, or rotator cuff tear from a multicenter database. Early poor performance was defined as a postoperative American Shoulder and Elbow Surgeons (ASES) score below the 20th percentile at 3 months (58 points) or 6 months (65 points) postoperatively. Persistent poor performance at 2 years was defined as failure to achieve the patient acceptable symptomatic state for rTSA (77.3 points for the ASES score). The primary outcome was the rate of persistent poor performance. Secondarily, we compared the clinical outcomes of persistent poor performers vs. shoulders that improved at 2-year follow-up and assessed risk factors for persistent poor performance.

RESULTS

At 2-year follow-up, 61% of patients (n = 178) with poor performance at either 3- or 6-month follow-up had persistent poor performance. The rate increased to 85% if poor performance occurred at both 3- and 6-month follow-up. The minimal clinically important difference and substantial clinical benefit for range of motion and outcome scores were exceeded by early poor performers at rates of 83%-92% and 60%-77%, respectively, at 2-year follow-up. On multivariate logistic regression analysis, independent predictors of persistent poor performance after rTSA were lack of hypertension (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.13-0.57; P < .001), heart disease (OR, 2.89; 95% CI, 1.24-6.77; P = .011), uncemented humeral fixation (OR, 0.11; 95% CI, 0.01-1.18; P = .037), previous shoulder surgery (OR, 2.14; 95% CI, 1.06-4.30; P = .031), lower preoperative ASES score (OR, 0.92; 95% CI, 0.87-0.97; P = .002), and lower preoperative subjective rating of pain at its worst (OR, 0.73; 95% CI, 0.54-0.99; P = .038).

DISCUSSION

Despite the fact that 85% of rTSA patients with an ASES score below the 20th percentile at early follow-up exceeded the minimal clinically important difference for improvement in the ASES score at 2-year clinical follow-up, 61% still had persistent poor performance, with failure to achieve the patient acceptable symptomatic state for the ASES score. Persistent poor performance after rTSA was best predicted by a history of shoulder surgery and a poorer preoperative ASES score. These findings can aid surgeons when counseling patients both preoperatively and postoperatively. In the setting of early poor performance, the risk of persistent poor performance must be balanced against the potential outcomes of revision surgery when considering early surgical intervention.

Influence of humeral lengthening on clinical outcomes in reverse shoulder arthroplasty

BACKGROUND

Deltoid tensioning secondary to humeral lengthening after reverse shoulder arthroplasty (RSA) is commonly theorized to be crucial to improving range of motion (ROM) but may predispose patients to acromial/scapular spine fractures and neurologic injury. Clinical evidence linking patient outcomes to humeral lengthening is limited. This study assesses the relationship between humeral lengthening and clinical outcomes after RSA.

METHODS

A single institution review of 284 RSAs performed in 265 patients was performed. Humeral lengthening was defined as the difference in the subacromial height preoperatively to postoperatively as measured on Grashey radiographs. The subacromial height was measured as the vertical difference between the most inferolateral aspect of the acromion and the most superior aspect of the greater tuberosity. The relationship between humeral lengthening and clinical outcomes was assessed on a continuous basis. Secondarily, clinical outcomes were assessed using a dichotomous definition of humeral lengthening (≤25 vs. >25mm) based on prior clinical and biomechanical work purporting a correlation with clinical outcomes. Improvement exceeding the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) for ROM and outcome scores after RSA were also compared.

RESULTS

Humeral lengthening demonstrated a nonlinear relationship with postoperative ROM, clinical outcome scores, and shoulder strength and their improvement preoperatively to postoperatively. Furthermore, there were minimal differences in ROM measures, outcome scores, and shoulder strength when stratified using the dichotomous definition of humeral lengthening. No difference in the proportion of patients exceeding the MCID or SCB when stratified by humeral lengthening ≤25 vs. >25mm was found. There was no difference in humeral lengthening in patients with versus without complications.

CONCLUSION

No clear relationship between humeral lengthening and clinical outcomes was identified. The previously purported 25mm threshold for humeral lengthening did not predict improved patient outcomes. Outcomes after RSA are multifactorial; the relationship between humeral lengthening and outcomes is likely confounded by other patient and surgical factors.

LEVEL OF EVIDENCE

IV; Case Series.

Effects of neuromuscular electrical muscle stimulation on the deltoid for shoulder function restoration after reverse total shoulder arthroplasty in the early recovery period: a prospective randomized study

INTRODUCTION

Neuromuscular electrical stimulation (NMES) is a treatment modality that has been used to accelerate the rehabilitation of patients with neurological damage. However, it is unclear whether NMES of the deltoid can lead to the early restoration of shoulder function after reverse total shoulder arthroplasty (RSA).

MATERIALS AND METHODS

In this prospective and randomized study, 88 patients who underwent RSA with the same prosthesis design for cuff tear arthropathy or irreparable rotator cuff tear were assessed. The patients were divided into two groups (NMES group and non-NMES group, 44 patients each). For the NMES group, two pads of the NMES device were placed over the middle and posterior deltoid area, and NMES was maintained for 1 month after surgery. Shoulder functional outcomes and deltoid thickness were compared at 3, 6, and 12 months postoperatively. Shoulder functional outcomes were assessed based on the visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES), and Constant scores and the range of motion (ROM) and power of the affected shoulder. The thickness of the anterior, middle, and posterior deltoid was measured by ultrasonography.

RESULTS

A total of 76 patients (NMES group, 33 patients; non-NMES group, 43 patients) were enrolled in the final analysis. The preoperative demographics and status of the remaining rotator cuff of both groups were not significantly different. At postoperative 3 months, the ROM and power of external rotation of the NMES group were significantly greater than those of the non-NMES group (ROM, 36° ± 14° vs. 29° ± 12°; P = .003; power, 4.8 kg ± 1.8 kg vs. 3.8 kg ± 1.0 kg; P < .002). The ROM of external rotation of the NMES group at postoperative 6 months was also greater than that of the non-NMES group (41° ± 12° vs. 34° ± 11°; P = .013). However, there was no significant difference in the VAS, ASES, and Constant scores at all follow-up points despite gradual improvements until 1 year postoperatively. Serial measurements of the thickness of the anterior, middle, and posterior deltoid of both groups did not show significant differences.

CONCLUSIONS

Postoperative NMES of the deltoid after RSA contributed to significantly faster ROM restoration and considerable improvement in the power of external rotation. Therefore, NMES following RSA could lead to the early restoration of external rotation and recovery of deltoid function.

Reverse shoulder arthroplasty yields similar results to anatomic total shoulder arthroplasty for the treatment of humeral head avascular necrosis

BACKGROUND

Avascular necrosis (AVN) of the humeral head frequently results in humeral head collapse and end-stage arthritic changes of the glenohumeral joint. Despite the recent proliferation of reverse total shoulder arthroplasty (RTSA), reports on the use of RTSA for AVN remain limited. The purpose of this study was to document the outcomes of shoulders indicated for RTSA in the setting of humeral head AVN and compare these with AVN shoulders indicated for the gold standard, anatomic total shoulder arthroplasty (aTSA).

METHODS

A retrospective review of a multinational shoulder arthroplasty database was performed between August 2005 and August 2017. All shoulders with a preoperative diagnosis of AVN (aTSA in 52 and RTSA in 67) were reviewed. The shoulders in the RTSA cohort were matched (1:1) to shoulders with cuff tear arthropathy, whereas the shoulders in the aTSA cohort were matched (1:1) to shoulders with primary osteoarthritis. The mean follow-up period was 47 months (range, 24-130 months) for RTSA and 54 months (range, 24-124 months) for aTSA. Shoulders were evaluated for active range of motion (ROM) and patient-reported outcome measures (PROMs) prior to surgery and at latest follow-up. Patients treated with RTSA were compared with both the aTSA study cohort and the control group using the Student t test or χ² test as indicated.

RESULTS

RTSAs performed for AVN demonstrated significant improvements in all ROMs and PROMs. Patients undergoing aTSA for AVN were significantly younger than those undergoing RTSA (59 years vs. 73 years, P < .001). At similar follow-up points, the RTSA cohort demonstrated significantly greater improvement in abduction (+51° vs. +32°, P = .03) whereas the aTSA cohort demonstrated significantly greater improvement in internal rotation. Postoperative University of California, Los Angeles scores (30 vs. 27, P = .014) and visual analog scale scores (1.4 vs. 2.4, P = .025) were better after RTSA; however, these differences between prosthesis types did not exceed the minimal clinically important difference. When compared with the control patients, the patients undergoing RTSA for AVN showed similar improvements in all ROMs and PROMs. Similarly, aTSA performed for AVN resulted in comparable improvements in pain, ROMs, and PROMs compared with aTSA performed for primary osteoarthritis.

CONCLUSION

RTSA results in similar PROMs to aTSA in the treatment of AVN. Therefore, surgeons should continue to consider other patient factors such as glenoid bone loss and rotator cuff status when selecting implant polarity in patients with AVN.

Patient age at time of reverse shoulder arthroplasty remains stable over time: a 7.5-year trend evaluation

PURPOSE

There is a common belief among some shoulder surgeons that the increased utilization of reverse shoulder arthroplasty (RSA) is driven by the operation being performed in younger patients. The primary purpose of this study was to evaluate the change in patient age at the time of primary RSA in the USA.

METHODS

All patients undergoing primary RSA (January 2011-June 2018) were identified in the Mariner database. The mean age at the time of primary RSA was evaluated for each patient and assessed in 6-month intervals. A longitudinal comparison over time was performed for all patients.

RESULTS

A total of 56,141 primary RSA were evaluated, with the mean age increasing from 69 in the 2011 to 71 in 2018 (p < 0.001). The largest increase in RSA utilization occurred in patients > 70 (1092 in 2011 to 3499 in 2018), with patients < 50 years demonstrating the slowest growth (13 in 2011 to 65 in 2018). However, when evaluated by percentage increase from 2011 to 2018, RSA volumes for patients < 60 have increased 390% compared to 220% for those > 70 years (p < 0.001).

CONCLUSION

RSA continues to be performed at a similar mean age despite expanded indications and surgeon comfort. However, patients < 60 years have had a greater increase in utilization compared to patients > 70 years. The volumetric growth of RSA has largely been driven by the older population, but younger patients have shown a higher percentage of growth, which may explain the generalized observation that RSA is performed in younger patients.

LEVEL OF EVIDENCE

Level III; Retrospective comparative study; Treatment study.

Deltoid fatigue part 2: a longitudinal assessment of anatomic total shoulder arthroplasty over time

BACKGROUND

Gradual loss of overhead range of motion (ROM) has been observed after reverse shoulder arthroplasty (RSA). It remains unclear if this is caused by the effect of RSA design on muscle fiber lengthening or is part of the natural aging process of the shoulder musculature. Although studies have attempted to evaluate deltoid fatigue after RSA, there is a paucity of literature evaluating this effect after anatomic shoulder arthroplasty (aTSA), which would be expected to occur due to aging alone. The purpose of this study is to evaluate the effect of time on overhead ROM after aTSA and compare this with previous data on a similar cohort of RSAs. We hypothesized that overhead ROM would decrease gradually over time in both groups without differences between prosthesis types.

METHODS

A retrospective review of 384 aTSAs without complications was performed over a 10-year period. All shoulders were treated for primary osteoarthritis using a single implant system. Patients were evaluated longitudinally at multiple postoperative time points. At least 1 follow-up visit was between 1 and 2 years postoperatively and another at least 5 years after surgery. ROM and patient reported outcome measures (PROMs) were evaluated using linear-mixed models for repeated measures. These results were compared with a previously evaluated cohort of 165 well-functioning RSAs analyzed using the same methodology.

RESULTS

Primary aTSA shoulders were observed to lose 0.7° of abduction per year starting 1 year postoperatively (P = .001). Smaller losses were observed in external rotation (-0.3°/yr, P = .06) and internal rotation (-0.04/yr, P < .001). However, no significant losses were observed in forward elevation (P = .8). All PROMs diminished slowly over time, but these changes did not exceed the minimally clinically important difference when modeled over 10 years (Simple Shoulder Test -0.08/yr, P < .001; American Shoulder Elbow Surgeons -0.5/yr, P < .001; University of California Los Angeles Shoulder Score -0.2/yr, P < .001). When compared with a similarly analyzed cohort of RSAs, overhead ROM decreased at a slower rate in the aTSA cohort (abduction -0.7° vs. -0.8°/yr, P = .9; FE -0.06° vs. -0.8°/yr, P = .05).

DISCUSSION

In the well-functioning aTSA, gradual loss of ROM occurs in all planes of motion except forward elevation. However, these losses are small and have little meaningful impact relative to minimally clinically important difference thresholds on PROMs. Progressive loss of abduction seen in both aTSA and RSA is likely secondary to aging of the periscapular and rotator cuff musculature. When compared with RSA, loss of motion after aTSA was statistically similar, calling into question the belief that RSA-induced deltoid fatigue leads to loss of overhead motion over time.

Comparison of Early Range of Motion in Reverse Shoulder Arthroplasty Based on Indication: A Single Center Retrospective Review

Background

Reverse shoulder arthroplasty (RSA) is commonly used in the treatment of rotator cuff arthropathy. Indications for RSA have expanded to include complex proximal humerus fractures. Studies directly comparing outcomes between traumatic and traditional elective indications are limited. The purpose of this study was to compare early active range of motion (aROM) within the first two years postoperatively between traumatic and non-traumatic primary RSA, as well as compare ASES scores, and patient satisfaction at final follow-up.

Methods

A retrospective analysis was conducted of all RSA performed by a single surgeon between January 2000 and December 2018. Patients were grouped by indication into traumatic and non-traumatic elective groups. Demographics, surgical data, and routine aROM data were collected. aROM was compared at 3, 6, 12, and 24 months. American Shoulder and Elbow Surgeons (ASES) score and patient satisfaction were determined at the time of this investigation.

Results

367 RSA procedures were performed by the senior author during the study period, 88 for fracture (24%), and 279 for non-traumatic elective indications (76%). Forward elevation and external rotation were inferior in the fracture group at all time points in the first two years. Internal rotation was equivalent throughout the first two years. Final ASES scores were 77.6 versus 83.5 in the fracture and non-fracture groups, respectively (p = .33).

Conclusion

Patients undergoing RSA for fracture had statistically significant inferior aROM in forward elevation and external rotation throughout the first two years. Despite having inferior aROM, ASES scores and patient satisfaction at final follow-up were statistically equivalent.

Level of Evidence

Level III; Retrospective Cohort Comparision; Prognosis Study