Can a functional difference be detected in reverse arthroplasty with 135° versus 155° prosthesis for the treatment of rotator cuff arthropathy: a prospective randomized study

The fragility of statistical findings in the reverse total shoulder arthroplasty literature: a systematic review of randomized controlled trials

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) has seen increasing utilization as an effective intervention for a wide variety of shoulder pathologies. The scope and indications for growth are often driven by findings from randomized controlled trials (RCTs) guiding surgical decision-making for RTSA. In this study, we utilized the fragility index (FI), reverse fragility index (rFI), and fragility quotient (FQ) to assess the robustness of outcomes reported in RCTs in the RTSA literature.

METHODS

PubMed, Embase, and MEDLINE were queried for RCTs (Jan. 1, 2010-Mar. 31, 2023) in the RTSA literature reporting dichotomous outcomes. The FI and rFI were defined as the number of outcome reversals required to alter statistical significance for significant and nonsignificant outcomes, respectively. The FQ was determined by dividing the FI by the sample size of each study. Subgroup analysis was performed based on outcome category.

RESULTS

One hundred seventy-six RCTs were screened with 18 studies included. The median FI across 59 total outcomes was 4 (interquartile range [IQR]: 3-5) with an associated FQ of 0.051 (IQR: 0.029-0.065). Thirteen outcomes were statistically significant with a median FI of 3 (IQR: 1-4) and FQ of 0.033 (IQR: 0.012-0.066). Forty-six outcomes were nonsignificant with a median rFI of 4 (IQR: 3-5) and FQ of 0.055 (IQR: 0.032-0.065). The most fragile outcome category was revision/reoperations with a median FI of 2.50 (IQR: 1.00-3.25), followed by clinical score/outcome (median FI: 3.00), complications (median FI: 4.00), "other" (median FI: 4.00), and radiographic findings (median FI: 5.00). Notably, the number of patients lost to follow-up was greater than or equal to the FI for 59% of outcomes.

CONCLUSION

The statistical findings in RTSA RCTs are fragile and should be interpreted with caution. Reversal of only a few outcomes, or maintaining postoperative follow-up, may be sufficient to alter significance of study findings. We recommend standardized reporting of P values with FI and FQ metrics to allow clinicians to effectively assess the robustness of study findings.

Rates of subacromial notching are low following reverse shoulder arthroplasty with a 135° inlay humeral component and a lateralized glenoid

Background

Lateralization in reverse shoulder arthroplasty (RSA) decreases bony impingement and improves rotational range of motion, but has been theorized to increase the risk of subacromial notching (SaN). The purpose of this study was to evaluate the presence of SaN following RSA and its relationship with lateralization with a 135° inlay humeral component. The secondary purpose was to assess the association of SaN with functional outcomes.

Methods

A retrospective review was performed from a multicenter prospectively collected database on patients who underwent primary RSA from 2015 to 2021. All RSAs were performed with a 135° inlay humeral component. SaN was defined as bony erosion with sclerotic margins on the undersurface of the acromion on final follow-up radiographs not present preoperatively. Postoperative implant positioning (inclination, distalization, and lateralization) were evaluated on minimum 1-year postoperative radiographs. Regression analyses were performed on implant and clinical variables to assess for risk factors. A separate analysis was performed to determine the association of SaN with clinical outcomes.

Results

SaN was identified in 13 out of 442 shoulders (2.9%). Age, sex, body mass index, smoking status, diabetes mellitus, arm dominance had no relationship with SaN. Neither glenoid sided lateralization nor humeral offset were associated with SaN risk. Other implant characteristics such as distalization, glenosphere size, and postoperative inclination did not influence SaN risk. The presence of SaN did not affect patient-reported outcomes (American Shoulder and Elbow Surgeons: P = .357, Visual Analog Scale: P = .210) or range of motion.

Conclusion

The rate of SaN is low and not associated with glenoid or humeral prosthetic lateralization when using a 135° inlay humeral component. When SaN occurs, it is not associated with functional outcomes or range of motion at short-term follow-up.

Influence of lateralized versus medialized reverse shoulder arthroplasty design on external and internal rotation: a systematic review and meta-analysis

BACKGROUND

Restoration of external (ER) and internal rotation (IR) after Grammont-style reverse shoulder arthroplasty (RSA) is often unreliable. The purpose of this systematic review was to evaluate the influence of RSA medio-lateral offset and subscapularis repair on axial rotation after RSA.

METHODS

We conducted a systematic review of studies evaluating axial rotation (ER, IR, or both) after RSA with a defined implant design. Medio-lateral implant classification was adopted from Werthel et al. Meta-analysis was conducted using a random-effects model.

RESULTS

Thirty-two studies reporting 2,233 RSAs were included (mean patient age, 72.5 years; follow-up, 43 months; 64% female). The subscapularis was repaired in 91% (n=2,032) of shoulders and did not differ based on global implant lateralization (91% for both, P=0.602). On meta-analysis, globally lateralized implants achieved greater postoperative ER (40° [36°-44°] vs. 27° [22°-32°], P<0.001) and postoperative improvement in ER (20° [15°-26°] vs. 10° [5°-15°], P<0.001). Lateralized implants with subscapularis repair or medialized implants without subscapularis repair had significantly greater postoperative ER and postoperative improvement in ER compared to globally medialized implants with subscapularis repair (P<0.001 for both). Mean postoperative IR was reported in 56% (n=18) of studies and achieved the minimum necessary IR in 51% of lateralized (n=325, 5 cohorts) versus 36% (n=177, 5 cohorts) of medialized implants.

CONCLUSIONS

Lateralized RSA produces superior axial rotation compared to medialized RSA. Lateralized RSA with subscapularis repair and medialized RSA without subscapularis repair provide greater axial rotation compared to medialized RSA with subscapularis repair. Level of evidence: 2A.

Is preoperative 3D planning reliable for predicting postoperative clinical differences in range of motion between two stem designs in reverse shoulder arthroplasty

BACKGROUND

We aim to predict a clinical difference in the postoperative range of motion (RoM) between 2 reverse shoulder arthroplasty (RSA) stem designs (Inlay-155° and Onlay-145°) using preoperative planning software. We hypothesized that preoperative 3D planning could anticipate the differences in postoperative clinical RoM between 2 humeral stem designs and by keeping the same glenoid implant.

METHODS

Thirty-seven patients (14 men and 23 women, 76 ± 7 years) underwent a BIO-RSA (bony increased offset-RSA) with the use of preoperative planning and an intraoperative 3-dimensional-printed patient-specific guide for glenoid component implantation between January 2014 and September 2019 with a minimum follow-up of 2 years. Two types of humeral implants were used: Inlay with a 155° inclination (Inlay-155°) and Onlay with a 145°inclination (Onlay-145°). Glenoid implants remained unchanged. The postoperative RSA angle (inclination of the area in which the glenoid component of the RSA is implanted) and the lateralization shoulder angle were measured to confirm the good positioning of the glenoid implant and the global lateralization on postoperative X-rays. A correlation between simulated and clinical RoM was studied. Simulated and last follow-up active forward flexion (AFE), abduction, and external rotation (ER) were compared between the 2 types of implants.

RESULTS

No significant difference in RSA and lateralization shoulder angle was found between planned and postoperative radiological implants' position. Clinical RoM at the last follow-up was always significantly different from simulated preoperative RoM. A low-to-moderate but significant correlation existed for AFE, abduction, and ER (r = 0.45, r = 0.47, and r = 0.57, respectively; P < .01). AFE and abduction were systematically underestimated (126° ± 16° and 95° ± 13° simulated vs. 150° ± 24° and 114° ± 13° postoperatively; P < .001), whereas ER was systematically overestimated (50° ± 19° simulated vs. 36° ± 19° postoperatively; P < .001). Simulated abduction and ER highlighted a significant difference between Inlay-155° and Onlay-145° (12° ± 2°, P = .01, and 23° ± 3°, P < .001), and this was also retrieved clinically at the last follow-up (23° ± 2°, P = .02, and 22° ± 2°, P < .001).

CONCLUSIONS

This study is the first to evaluate the clinical relevance of predicted RoM for RSA preoperative planning. Motion that involves the scapulothoracic joint (AFE and abduction) is underestimated, while ER is overestimated. However, preoperative planning provides clinically relevant RoM prediction with a significant correlation between both and brings reliable data when comparing 2 different types of humeral implants (Inlay-155° and Onlay-145°) for abduction and ER. Thus, RoM simulation is a valuable tool to optimize implant selection and choose RSA implants to reach the optimal RoM.

The statistical fragility of the management options for reverse shoulder arthroplasty: a systematic review of randomized control trial with fragility analysis

Reverse shoulder arthroplasty (RSA) is used in the treatment of traumatic and arthritic pathologies, with expanding clinical indications and as a result there has been an increase in clinical research on the topic. The purpose of this study was to examine the statistical fragility of randomized control trials (RCTs) reporting outcomes from RSA. A systematic search was undertaken to find RCTs investigating RSA. The Fragility Index (FI) was calculated using Fisher's exact test, by sequentially altering the number of events until there was a reversal of significance. The Fragility Quotient (FQ) was calculated by dividing the FI by the trial population. Each trial was assigned an overall FI and FQ calculated as the median result of its reported findings. Overall, 19 RCTs warranted inclusion in the review, representing 1146 patients, of which 41.2% were male, with a mean age of 74.2 ± 4.3 years and mean follow-up of 22.1 ± 9.9 months. The median RCT population was 59, with a median of 9 patients lost to follow-up. The median FI was 4.5, and median FQ was 0.083, indicating more patients did not complete the trial than the number of outcomes which would have to change to reverse the finding of significance. This review found that the RCT evidence for RSA management may be vulnerable to statistical fragility, with a handful of events required to reverse a finding of significance.

The association between reverse total shoulder arthroplasty neck-shaft angle on postoperative patient experienced shoulder disability: a retrospective cohort study

Background

The neck-shaft angle (NSA) of the glenoid component used in reverse total shoulder arthroplasty (RTSA) was reduced to improve functional outcomes. This led to a decreased abduction but increased external rotation ability of patients who underwent RTSA. The impact of the decreased NSA on patient-reported shoulder disability is unknown but may have important implications for functional ability. Therefore, the aim of this study was to assess the difference in patient experienced shoulder disability between an NSA of 135° and 155° 12 months after RTSA.

Methods

In this retrospective cohort study, 109 patients undergoing RTSA were included. In 68 patients, a glenoid component with an NSA of 135° was used and 41 patients received a glenoid component with an NSA of 155°. The primary outcome was Disabilities of the Arm, Shoulder, and Hand (DASH) scores at 12 months and change scores between baseline and 12-month follow-up. Secondary outcomes were complications, Constant Murley Score, Numeric Rating Scale, active forward elevation and external rotation ability. Differences between groups were tested with t-tests or Mann-Whitney U-tests.

Results

A mean difference of 10.0 in 12 months postoperative DASH scores between NSA groups was observed in favor of the 135° NSA (P = .004), which did not exceed the Minimal Clinically Important Difference. DASH changes scores did not differ between NSA groups (P = .652). Mean postoperative Constant Murley Score at 12 months was 11.1 higher in the 135° NSA group (P = .013). No differences were observed in complications (P = .721) and postoperative pain (P = .710) between groups. Difference in postoperative external rotation and forward elevation at 12 months was 10° (P = .022) and 20° (P = .046), respectively, in favor of the 135° NSA group, exceeding Minimal Clinically Important Differences.

Conclusions

No clinically important difference in patient-reported shoulder disability (DASH) was found between both groups, despite a larger range of motion in the 135° NSA group. This study is the first to show the impact of NSA on patient-reported shoulder disability using the DASH.

Onlay versus inlay humeral components in reverse shoulder arthroplasty: A systematic review and meta-analysis

Background

Advances have been made to the traditional inlay Grammont Reverse Shoulder Arthroplasty (RSA) design such as the onlay humeral component prosthesis. Currently, there is no agreement in the literature regarding the best option for the humeral component when comparing inlay and onlay designs. This review compares the outcomes and complications between onlay versus inlay humeral components for RSA.

Methods

A literature search was conducted using PubMed and Embase. Only studies reporting outcomes comparing onlay versus inlay RSA humeral components were included.

Results

Four studies with 298 patients (306 shoulders) were included. Onlay humeral components were associated with better external rotation (ER) (p < 0.0001). No significant difference in forward flexion (FF) or abduction was found. Constant scores (CS) and VAS scores did not differ. Increased scapular notching was found in the inlay group (23.18%) versus the onlay group (7.74%) (p = 0.02). Postoperative scapular fractures and acromial fractures did not differ.

Conclusion

Onlay and inlay RSA designs are associated with improved postoperative range of motion (ROM). Onlay humeral designs may be associated with greater ER and lower rate of scapular notching; however, no difference was found in Constant and VAS scores, so further studies are required to assess the clinical significance of these differences.

Results after primary reverse shoulder arthroplasty with and without subscapularis repair: a prospective-randomized trial

INTRODUCTION

Indications for reverse shoulder arthroplasties (rTSA) have increased since their development by Paul Grammont in 1985. Prosthesis design was enhanced over time, but the management of the tendon of the M. subscapularis (SSC-tendon) in primary rTSA is still a controversial subject with regard to perform a refixation or not.

METHODS

50 patients were randomized in a refixation group (A) and a non-refixation-group (B) of the SSC-tendon in a double-blinded fashion. SSC-function was assessed at baseline before surgery, such as 3 and 12 months after surgery. Constant-Murley-Shoulder Score (CS), American Shoulder and Elbow Surgeons Score (ASES), strength, range of motion (ROM), and pain on numeric rating scale (NRS) were measured in all examinations. An ultrasound examination of the shoulder was performed for evaluation of subscapularis tendon integrity at 3 and 12 month follow-up visits. Pain was evaluated on NRS via phone 5 days after surgery. Surgery was performed by a single experienced senior surgeon in all patients.

RESULTS

Patients with a refixation of the SSC-tendon and primary rTSA had improved internal rotation [40° (20°-60°) vs. 32° (20°-45°); p = 0.03] at 12 months of follow-up. Additionally, the A-group had increased CS [74 (13-90) vs. 69.5 (40-79); p = 0.029] 1 year after surgery. Results were strengthened by subgroup analysis of successful refixation in ultrasound examination vs. no refixation. No differences were seen in ASES and NRS 1 year after rTSA.

CONCLUSION

SSC-tendon repair in rTSA improves CS and internal rotation 12 months after surgery.

Influence of neck shaft angle of humerus in prosthesis design

Background

A better understanding of the proximal humerus is essential for anatomical reconstruction of the glenohumeral joint during prosthetic replacement. The neck-shaft angle is critical for correct calcar screw positioning when fixing a proximal humeral fracture with a locking plate. It's essential for exact implant placement and treatment of any soft-tissue or bone pathology. Improper implants cause discomfort and post-operative complications, therefore understanding the humeral neck shaft angle is fundamental in the design and manufacturing of prostheses. This study looked into the necessity regional data of the humeral neck shaft angle (NSA) and its importance in shoulder prosthesis manufacturing.

Method

This cross-sectional investigation was conducted on 300 dry cadaveric humeri of unknown gender and age that were free of damage or deformity. The Goniometer was used to measure the neck shaft angle. The data was analysed using SPSS software. The standard deviation and mean were calculated. The statistical difference between the right and left humeri was assessed using the students' t' test.

Observations

The NSA of the humerus was 131.265.82° on average. The NSA mean values were substantially higher on the right side. A statistically significant difference between the right and left humeri was revealed by a P value of 0.001.

Conclusion

Success of the shoulder arthroplasty demands anatomical reconstruction of the normal neck-shaft angle of the humerus. Racial variations in the morphometry of the neck-shaft angle needs to be considered in prosthesis design.

Treatment of proximal humerus fractures using reverse shoulder arthroplasty: do the inclination of the humeral component and the lateral offset of the glenosphere influence the clinical outcome and tuberosity healing?

INTRODUCTION

The employment of reverse shoulder arthroplasty for dislocated proximal humerus fractures of elderly patients becomes increasingly relevant. The standard inclination angle of the humeral component was 155°. Lately, there is a trend towards smaller inclination angles of 145° or 135°. Additionally, there has been an increased focus on the lateralization of the glenosphere. This retrospective comparative study evaluates clinical and radiological results of patients treated for proximal humerus fractures by reverse shoulder arthroplasty with different inclination angles of the humeral component, which was either 135° or 155°. Additionally, a different lateral offset of the glenosphere, which was either 0 mm or 4 mm, was used.

METHODS

For this retrospective comparative analysis, 58 out of 66 patients treated by reverse total shoulder arthroplasty for proximal humerus fractures were included. The minimum follow-up was 24 months. Thirty (m = 3, f = 27; mean age 78 years; mean FU 35 months, range 24-58 months) were treated with a standard 155° humeral component and a glenosphere without lateral offset (group A), while 28 patients (m = 2, f = 26; mean age 79 years; mean FU 30 months, range 24-46 months) were treated with a 135° humeral component and a glenosphere with a 4 mm lateral offset (group B). We determined range of motion, Constant score, and the American Shoulder and Elbow Surgeons Shoulder score as clinical outcomes and evaluated tuberosity healing as well as scapula notching.

RESULTS

Neither forward flexion (A = 128°, B = 121°; p = 0.710) nor abduction (A = 111°, B = 106°; p = 0.327) revealed differences between the groups. The mean Constant Score rated 63 in group A, while it was 61 in group B (p = 0.350). There were no differences of the ASES Score between the groups (A = 74, B = 72; p = 0.270). There was an increased risk for scapula notching in group A (47%) in comparison to group B (4%, p = 0.001). Healing of the greater tuberosity was achieved in 57% of group A and in 75% of group B (p = 0.142). The healing rate of the lesser tuberosity measured 33% in group A and 71% in group B (p = 0.004).

CONCLUSIONS

Both inclination angles of the humeral component are feasible options for the treatment of proximal humerus fractures in elderly patients. Neither the inclination angle nor the lateral offset of the glenosphere seem to have a relevant influence on the clinical outcome. The healing rate of the lesser tuberosity was higher in implants with a decreased neck-shaft angle. There is an increased risk for scapula notching, if a higher inclination angle of the humeral component is chosen.

LEVEL OF EVIDENCE

III. Retrospective comparative study.

Inlay versus onlay humeral design for reverse shoulder arthroplasty: a systematic review and meta-analysis

BACKGROUND

Since the introduction of the Grammont-style reverse total shoulder arthroplasty, the humeral stem design has been modified with improved clinical outcomes. Two distinct humeral designs have been used extensively: the inlay design, in which the humeral tray is seated within the metaphysis, and the onlay design, in which the humeral tray sits on the metaphysis at the level of the humeral neck cut. The purpose of this systematic review was to determine whether there are differences in clinical outcomes and complication rates between these designs.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used to perform this systematic review. A search of MEDLINE, PubMed, and Embase was performed to identify all studies comparing the clinical results of both humeral designs. Primary outcomes included patient-reported outcome measures, shoulder range of motion, and incidence of complications.

RESULTS

From the 156 identified publications, 12 studies were included in the final review. A total of 1447 patients were included, with a minimum follow-up period of 12 months. At final follow-up, both implants demonstrated significant improvements in comparison to preoperative baseline. On comparison of the inlay vs. onlay groups, the American Shoulder and Elbow Surgeons score was higher in the inlay group (mean difference, 2.53 [95% confidence interval, 0.27-4.78]; P = .03). Postoperative motion, even if statistically greater in the onlay group (differences of 5° in forward flexion [P < .001], 3° in abduction [P = .003], and 4° in external rotation [P < .001]), was not clinically different. On comparison of complications, the inlay group showed more instances of scapular notching (93 of 322 patients vs. 70 of 415 patients; odds ratio, 0.35; P < .001) but fewer scapular spine fractures (26 of 727 patients vs. 21 of 559 patients, P = .09).

DISCUSSION

Inlay and onlay humeral tray designs in reverse total shoulder arthroplasty demonstrate similar clinical improvements postoperatively. Onlay implants have a low rate of scapular notching but a higher rate of scapular spine fracture. Understanding the strengths and weaknesses of the 2 humeral tray designs is important to provide surgeons with options to tailor surgical plans for high-risk patients.

Outcomes and complications of primary reverse shoulder arthroplasty with minimum of 2 years' follow-up: a systematic review and meta-analysis

BACKGROUND

Primary reverse shoulder arthroplasty (rTSA) is an effective treatment option for reducing pain and improving function for patients with rotator cuff tear arthropathy, irreparable rotator cuff tears, glenoid deformity, and other challenging clinical scenarios, including fracture sequelae and revision shoulder arthroplasty. There has been a wide range of reported outcomes and postoperative complication rates reported in the literature. The purpose of this systematic review and meta-analysis is to provide an updated review of the clinical outcomes and complication rates following primary rTSA.

METHODS

A systematic review and meta-analysis was performed to evaluate outcomes and complications following primary rTSA according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Demographics, range of motion, patient-reported outcome measures (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES] and Constant scores), number of complications, and revisions were extracted, recorded, and analyzed from the included articles.

RESULTS

Of the 1415 studies screened, 52 studies met the inclusion criteria comprising a total of 5824 shoulders. The mean age at the time of surgery was 72 years (range: 34-93), and the mean follow-up was 3.9 years (range: 2-16). Patients demonstrated a mean improvement of 56° in active flexion, 50° in active abduction, and 14° in active external rotation. Regarding functional outcome scores, rTSA patients demonstrated a mean clinically significant improvement of 37 in Constant score (minimal clinically important difference [MCID] = 5.7) and ASES score (42.0; MCID = 13.6). The overall complication rate for rTSA was 9.4% and revision rate of 2.6%. Complications were further subdivided into major medical complications (0.07%), shoulder- or surgical-related complications (5.3%), and infections (1.2%). The most frequently reported shoulder- or surgical-related complications were scapular notching (14.4%), periprosthetic fracture (0.8%), glenoid loosening (0.7%), and prosthetic dislocation (0.7%).

DISCUSSION

Primary rTSA is a safe and reliable procedure with low complication, revision, infection, and scapular notching rates. Additionally, patients demonstrated clinically significant improvements in both range of motion and clinical outcome scores.

Which lateralization designed prosthesis of reverse total shoulder arthroplasty (glenoid-based lateralization vs humerus-based lateralization) would be better? Network Meta-analysis

PURPOSE

To demonstrate the differences between outcomes and complications after reverse total shoulder arthroplasty (rTSA), according to the types of lateralized prosthesis designs: glenoid-based lateralization (LG) and humerus-based lateralization (LH).

METHODS

PubMed, Embase, and the Cochrane Library databases were systematically searched for studies published before 1 April 2021, using the PRISMA guidelines. A network meta-analysis was applied for indirect comparison, incorporating studies including medialized or conventional Grammont prosthesis and each lateralized prosthesis (LG vs control and LH vs control). Out of 1,989 screened studies, 11 studies were included to compare functional scores, range of motion (ROM), radiologic outcomes, and revision rates. In addition, six articles from the included studies, which had repaired subscapularis after rTSA were analyzed to exclude the potential influence of subscapularis repair on the outcomes. The data were pooled using a random-effects model. The pooled estimates of the mean differences (MDs) and 95% confidence intervals (CIs) were calculated for continuous data, while dichotomous data were analyzed using the pooled relative risk (RR) and their 95% CIs.

RESULTS

The ROM, complications, and functional scores were similar between the two groups. In subgroup analysis of 6 studies involving concomitant subscapularis repair, the LH group showed higher American Shoulder and Elbow Surgeons (ASES) scores and Constant scores than the control group. Regarding the ROM, LH group showed better forward elevation than the LG group (LH vs LG: MD 10.07, 95% CI -9.05-29.19).

CONCLUSION

Overall, the outcomes and occurrence of complications were not significantly different between the two lateralized prosthesis groups. However, when the subscapularis was repaired, LH prosthesis seems to be more suitable to obtain a better ASES score and ROM.

LEVEL OF EVIDENCE

Level III, network meta-analysis.

The Role of Humeral Neck-Shaft Angle in Reverse Total Shoulder Arthroplasty: 155° versus <155°—A Systematic Review

The aim of this study was to have updated scrutiny of the influence of the humeral neck-shaft angle (HNSA) in patients who underwent reverse shoulder arthroplasty (RSA). A PRISMA-guided literature search was conducted from May to September 2021. Clinical outcome scores, functional parameters, and any complications were reviewed. Eleven papers were identified for inclusion in this systematic review. A total of 971 shoulders were evaluated at a minimum-follow up of 12 months, and a maximum of 120 months. The sample size for the "HNSA 155°" group is 449 patients, the "HNSA 145°" group involves 140 patients, and the "HSNA 135°" group comprises 291 patients. The HNSA represents an important variable in choosing the RSA implant design for patients with rotator cuff arthropathy. Positive outcomes are described for all the 155°, 145°, and 135° HSNA groups. Among the different implant designs, the 155° group show a better SST score, but also the highest rate of revisions and scapular notching; the 145° cohort achieve the best values in terms of active forward flexion, abduction, ASES score, and CMS, but also the highest rate of infections; while the 135° design obtains the best results in the external rotation with arm at side, but also the highest rate of fractures. High-quality studies are required to obtain valid results regarding the best prosthesis implant.

Implant characteristics affect in vivo shoulder kinematics during multiplanar functional motions after reverse shoulder arthroplasty

The purpose of this study was to determine how implant characteristics affect in vivo shoulder kinematics after reverse shoulder arthroplasty (RSA). Kinematics of the affected upper limb were measured in 32 participants during five motions (scapular plane abduction, hand-to-head, hand-to-back, internal/external rotation at 90° abduction, and circumduction) using optical motion capture. Shoulder abduction, plane of elevation, and internal/external rotation range of motion (ROM), peak angles, and continuous kinematics waveforms were calculated for each motion. Multiple regression was used to identify associations between kinematics and implant characteristics of lateralization, humeral retroversion, glenosphere size, glenosphere tilt, glenoid eccentricity, and implant neck-shaft angle (135° or 145°). Less humeral retroversion was associated with greater shoulder rotation ROM (p = 0.036) and greater plane of elevation ROM (p = 0.024) during circumduction, while less eccentricity was associated with more posterior plane of elevation during hand-to-back (p = 0.021). The 145° implant was associated with greater internal/external shoulder rotation ROM (p < 0.001), greater internal shoulder rotation (p = 0.002), and greater plane of elevation ROM (p = 001) during the hand-to-back. The 145° implant was also associated with more internal/external rotation ROM (p = 0.043) during shoulder rotation and more abduction ROM during circumduction (p = 0.043). During the hand-to-back motion, individuals having 135° neck-shaft angle implants were more abducted from 21 to 51% of the motion and were less internally rotated from 70 to 100% of the motion, while more lateralization was associated with less internal rotation from 90 to 100% of the motion. Retroversion and implant neck-shaft angle are the primary implant characteristics associated with in vivo shoulder kinematics during complex motions after RSA.

Patient Posture Affects Simulated ROM in Reverse Total Shoulder Arthroplasty: A Modeling Study Using Preoperative Planning Software

BACKGROUND

Component selection and placement in reverse total shoulder arthroplasty (RTSA) is still being debated. Recently, scapulothoracic orientation and posture have emerged as relevant factors when planning an RTSA. However, the degree to which those parameters may influence ROM and whether modifiable elements of implant configuration may be helpful in improving ROM among patients with different postures have not been thoroughly studied, and modeling them may be instructive.

QUESTIONS/PURPOSES

Using a dedicated expansion of a conventional preoperative planning software, we asked: (1) How is patient posture likely to influence simulated ROM after virtual RTSA implantation? (2) Do changes in implant configuration, such as humeral component inclination and retrotorsion, or glenoid component size and centricity improve the simulated ROM after virtual RTSA implantation in patients with different posture types?

METHODS

In a computer laboratory study, available whole-torso CT scans of 30 patients (20 males and 10 females with a mean age of 65 ± 17 years) were analyzed to determine the posture type (Type A, upright posture, retracted scapulae; Type B, intermediate; Type C, kyphotic posture with protracted scapulae) based on the measured scapula internal rotation as previously described. The measurement of scapular internal rotation, which defines these posture types, was found to have a high intraclass correlation coefficient (0.87) in a previous study, suggesting reliability of the employed classification. Three shoulder surgeons each independently virtually implanted a short, curved, metaphyseal impaction stem RTSA in each patient using three-dimensional (3D) preoperative surgical planning software. Modifications based on the original component positioning were automatically generated, including different humeral component retrotorsion (0°, 20°, and 40° of anatomic and scapular internal rotation) and neck-shaft angle (135°, 145°, and 155°) as well as glenoid component configuration (36-mm concentric, 36-mm eccentric, and 42-mm concentric), resulting in 3720 different RTSA configurations. For each configuration, the maximum potential ROM in different planes was determined by the software, and the effect of different posture types was analyzed by comparing subgroups.

RESULTS

Irrespective of the RTSA implant configuration, the posture types had a strong effect on the calculated ROM in all planes of motion, except for flexion. In particular, simulated ROM in patients with Type C compared with Type A posture demonstrated inferior adduction (median 5° [interquartile range -7° to 20°] versus 15° [IQR 7° to 22°]; p < 0.01), abduction (63° [IQR 48° to 78°] versus 72° [IQR 63° to 82°]; p < 0.01), extension (4° [IQR -8° to 12°] versus 19° [IQR 8° to 27°]; p < 0.01), and external rotation (7° [IQR -5° to 22°] versus 28° [IQR 13° to 39°]; p < 0.01). Lower retrotorsion and a higher neck-shaft angle of the humeral component as well as a small concentric glenosphere resulted in worse overall ROM in patients with Type C posture, with severe restriction of motion in adduction, extension, and external rotation to below 0°.

CONCLUSION

Different posture types affect the ROM after simulated RTSA implantation, regardless of implant configuration. An individualized choice of component configuration based on scapulothoracic orientation seems to attenuate the negative effects of posture Type B and C. Future studies on ROM after RTSA should consider patient posture and scapulothoracic orientation.

CLINICAL RELEVANCE

In patients with Type C posture, higher retrotorsion, a lower neck-shaft angle, and a larger or inferior eccentric glenosphere seem to be advantageous.

Lateralized vs. classic Grammont-style reverse shoulder arthroplasty for cuff deficiency Hamada stage 1-3: does the design make a difference?

BACKGROUND

Reverse shoulder arthroplasty (RSA) with a lateralized design is thought to improve outcomes. Our aim was to compare RSA with the classic Grammont prosthesis against a prosthesis with 135° inclination and a lateralized glenosphere for cuff-deficient shoulders.

METHODS

Patients with irreparable massive posterosuperior rotator cuff tear Hamada grade 1-3 underwent RSA and were documented prospectively up to 24 months postsurgery. Comparative RSA groups were "lateralized" (L), with 135° humeral inclination and 36+4-mm lateralized glenosphere (n = 44), and "Grammont" (G), with 155° humeral inclination and 36+2-mm eccentric glenosphere (n = 23). Range of motion including the Apley scratch test, abduction strength, Constant-Murley score (CS), and Shoulder Pain and Disability Index (SPADI) were assessed. Anteroposterior and axial radiographs were evaluated at 24 months, and additional measurements of scapular neck and glenoid anatomy, baseplate and glenosphere position, center of rotation, humeral offset, and lateralization and distalization shoulder angles were made. Linear regression and mixed models adjusted for sex differences and preoperative values were applied.

RESULTS

Overall CS and SPADI outcomes were not significantly different between groups (P ≥ .654). For group L, external rotation remained stable up to the 2-year follow-up and was higher than for group G (P = .012 ); a greater proportion of group L patients could reach the lumbar vertebra 3 (L3) (70% vs. 48% in group G) (P = .26). Group G had a higher inferior glenosphere overhang (P = .020) and center of rotation (COR) medialization (P < .001), whereas group L had higher humeral offset (P < .001) and lateralization shoulder angle (P < .001) with a trend toward higher baseplate positioning (P = .045). The rate of scapular notching was 2.9 times higher for group G than group L (P = .001).

CONCLUSION

RSA with 135° humeral inclination and a lateralized glenosphere shows similar outcome scores as the classic Grammont design but enables better preservation of external rotation and reduces the rate of scapular notching compared with the classic Grammont design in Hamada 1-3 patients with irreparable posterosuperior tears.

Bony increased-offset reverse shoulder arthroplasty (BIO-RSA) associated with eccentric glenosphere and an onlay 135° humeral component : Clinical and Radiological Outcomes at a minimum 2 year follow-up

Background

Various implant designs have been proposed to increase active range of motion (ROM) and avoid notching in patients treated by reverse total shoulder arthroplasty (RSA). The purpose of this study was to investigate the efficacy and safety of an onlay prosthesis design combining a 135° humeral neck-shaft angle with the glenoid component lateralized and inferiorized.

Methods

A retrospective descriptive study was conducted of the clinical and radiological outcomes at the final follow-up (≥24 months) of all RSAs performed by the same surgeon between September 2015 and December 2016 in the study center. At the last follow-up, patients were clinically assessed for ROM, Constant score, and subjective shoulder value and radiologically for scapular notching and glenoid radiolucent lines. Patients were followed up radiographically at 1 month and clinically at between 6 and 12 months (midterm) and again at between 24 and 48 months (final follow-up). Scapular notching was graded as per the Sirveaux classification at the last follow-up on anterior-posterior radiographs.

Results

Seventy-nine RSAs were included with a mean follow-up time of 31 months. The mean Constant score at the final follow-up was 42 points higher than before surgery (69 vs. 27, P < .001). There were also significant postoperative improvements in ROM (active anterior elevation, active external rotation, and active internal rotation). The final means for motions were 133° for active anterior elevation, 32° active external rotation, and level 7 for active internal rotation. The overall notching rate was 3% (2/67), and there were no cases of severe notching. Radiolucent lines were observed in 8 of 70 prostheses (11.5%) around the peg, and they were observed in 9 prostheses (13%) around the screws. Among the 79 RSAs included, there were 11 complications (13.9%) (two infections, two fractures, four cases of glenoid component loosening, and three cases of instability), 2 reoperations, and 4 prosthesis revisions.

Conclusion

This study shows that an RSA design with a 135° humeral neck-shaft angle and an inferiorized and lateralized glenoid component is associated with significant improvements in active ROM, especially in rotation, and a low notching rate. However, rates of 3.8% for dislocation and 5% for glenoid loosening are certainly a concern at such a short follow-up of two years. Future studies with a larger population are needed to confirm these rates.

Does Lateralizing the Glenosphere Center of Rotation by 4 mm Decrease Scapular Notching in Reverse Shoulder Arthroplasty with a 135° Humeral Component?

Background

Scapular notching continues to be associated with reverse shoulder arthroplasty (RSA) and is thought to lead to fewer outcomes. Decreasing the humeral neck-shaft angle (NSA) has been associated with decreased incidence of scapular notching. Lateralizing the glenosphere center of rotation (COR) has also been proposed to decrease notching; however, its effect in lower NSA RSA is less understood. The purpose of this study was to compare the impact of the medial (0 mm) and lateral (4 mm) COR on the incidence of scapular notching and clinical outcomes after RSA with a 135° NSA humeral component.

Methods

We performed a multicenter retrospective comparative cohort of 82 patients with cuff tear arthropathy (41 in each cohort) who underwent RSA with a 135° NSA humeral component and a glenosphere COR of either 0 mm (medialized COR [MCOR]) or 4 mm (lateralized COR [LCOR]) of lateralization. RSA was performed using the same 135° humeral system and baseplate design. All patients had 2-year radiographic and clinical follow-up. Postoperative radiographs were evaluated for scapular notching. Clinical outcomes included American Shoulder and Elbow Surgeons scores, visual analog pain scale, Simple Assessment Numeric Evaluation, and active range of motion.

Results

The overall incidence of scapular notching was 22.0%. There was no significant difference in scapular notching between cohorts: 24.4% in the MCOR and 19.5% in the LCOR (P = .625). Both cohorts had significant improvements in American Shoulder and Elbow Surgeons scores, visual analog pain scale, Simple Assessment Numeric Evaluation, and active range of motion postoperatively (P < .005). Improvements did not significantly differ between cohorts. The presence of scapular notching did not have a significant negative effect on any clinical outcome measure. Complications occurred in 5 patients (2 MCORs and 3 LCORs), none of which occurred in patients with scapular notching.

Discussion and conclusion

Lateralizing the glenosphere COR by 4 mm does not significantly affect the incidence of scapular notching in RSA when using a 135° NSA humeral component at short-term follow-up. Furthermore, such offset does not significantly improve functional outcome scoring systems or range of motion when compared with the MCOR (0 mm). Scapular notching did not have a negative impact on any clinical outcome measure or complication rate in this series.

Reverse Shoulder Arthroplasty Humeral Lateralisation: A Systematic Review

Different studies on reverse shoulder arthroplasty (RSA) have proposed changes to the humeral design to lateralise the humeral centre of rotation (COR), with humeral inclination to 135 or 145 from 155 degrees or to switch to onlay humeral trays from inlay design; with both having also been used in combination. There have been many studies and systematic reviews to show the difference in outcomes and complications to the variations in glenoid design but to date, there have been no systematic studies to compare different humeral inclinations for RSA implants.

Searches using keywords were used in common medical search engines in a systematic fashion. The article was reviewed for the class of evidence and bias, summarised and compared in meta-analysis. Inclusion criteria included studies on adults with RSA that compared lateralised humeral implants to medialised.

The search produced 349 articles; of these, we identified nine studies that met the inclusion criteria. Our review identified a total of 562 patients who had been included in studies directly comparing lateralised humerus to a more medial design. Meta-analysis showed a significantly reduced risk of scapular notching in lateralised humerus compared to the standard medialised component. The external rotation range of motion in the lateralised group was statistically significant.

The improvement in scapular notching and gain in the range of motion without any apparent downside in the form of reduced patient-reported outcome measures or complications suggest a lateralised humeral component is superior to the more medialised design in RSA. A large RCT with a longer-term follow-up is needed to confirm whether there is clinically significant benefit from the lateralisation of the humerus.

A comparison of patient-specific instrumentation to navigation for conducting humeral head osteotomies during shoulder arthroplasty

Background

The humeral head osteotomy during shoulder arthroplasty influences humeral component height, version and possibly neck-shaft angle. These parameters all potentially influence outcomes of anatomic and reverse shoulder replacement to a variable degree. Patient-specific guides and navigation have been studied and utilized clinically for glenoid component placement. Little, however, has been done to evaluate these techniques for humeral head osteotomies. The purpose of this study, therefore, was to evaluate the use of patient-specific guides and surgical navigation for executing a planned humeral head osteotomy.

Methods

The DICOM images of 10 shoulder computed tomography scans (5 normal and 5 osteoarthritic) were used to print 3D polylactic models of the humerus. Each model was duplicated, such that there were 2 identical groups of 10 models. After preoperative planning of a humeral head osteotomy, Group 1 underwent osteotomy via a patient-specific guide, while group 2 underwent a real time navigated osteotomy with an optically tracked sagittal saw. The cut height (millimeters), version (degrees) and neck-shaft angle (degrees) were recorded and statistically compared between groups.

Results

There were no statistically significant differences between patient-specific guides and navigation for osteotomy cut height (P = .45) and humeral version (P = .059). Navigation, however, resulted in significantly less neck-shaft angle error than the patient specific guides (P = .023). Subgroup analysis of the osteoarthritic cases showed statistical significance for navigation resulting in less version error than the patient specific guides (P = .048).

Conclusion

No significant differences were found between patient specific guides and navigation for recreation of the preoperatively planned humeral head cut height and version. Neck-shaft angle, however, had significantly less deviation from the preoperative plan when conducted with navigation.

Lateralized versus nonlateralized reverse total shoulder arthroplasty

Throughout the history of reverse total shoulder arthroplasty, the extent of lateral offset has changed considerably from "too lateral" to "too medial" and has been lately swinging back towards a point somewhere in between. Nonlateralized designs minimize shear forces on the glenoid and decrease force required by the deltoid. Glenoid lateralization decreases impingement and scapular notching and improves range of motion. Humeral lateralization achieves a more anatomic position of the tuberosities while maintaining a nonlateralized center of rotation. Several factors play a role in choosing the extent of lateral offset and method of lateralization.

Influence of humeral stem inclination in reverse shoulder arthroplasty on range of motion: a meta-analysis

Hypothesis

The reverse shoulder arthroplasty, as introduced by Grammont, has had many modifications over time. One of these modifications was reducing the neck-shaft angle (NSA) from 155 degrees to 135 degrees. Biomechanical studies indicated that lowering the NSA increases external rotation and reduces abduction and the incidence of scapular notching. The purpose of this study was to compare range of motion, functional outcome measures, and complications in patients undergoing reverse shoulder arthroplasty, depending on the NSA, through a systematic review and meta-analysis.

Methods

A literature search was conducted (articles published from January 1985 to January 2020) in the PubMed/MEDLINE, Embase, and CINAHL databases and the Cochrane library. All studies reporting outcomes after primary reverse shoulder arthroplasty for osteoarthritis and rotator cuff-related disease were included. Patients were divided into 2 groups: a medialized design (MD) with an NSA of 150-155 degrees and a lateralized design (LD) with an NSA of less than 150 degrees. Pooled effects were calculated in the form of mean differences and 95% confidence intervals (CIs). Risk of bias was assessed using the Risk Of Bias In Non-Randomized Studies - of Interventions tool for non-Randomized Controlled Trials and the Risk Of Bias 2 tool for Randomized Controlled Trials.

Results

A total of 21 studies and 3134 arthroplasties were included: 1366 with an MD and 1678 with an LD. The mean age was 73.0 years (MD 74.0 and LD 72.5). A direct comparative meta-analysis was not feasible, and therefore, all data were compared using the minimal clinically important difference. The MD group demonstrated a larger improvement in abduction (56.76°, 95% CI 37.03-76.49) than the LD group (48.52°, 95% CI 28.27-68.78), however the LD group demonstrated a larger improvement in external rotation with the arm at the side (MD: 7.69°, 95% CI 0.01-15.37; LD: 16.14° 95% CI 7.18-25.09). When looking at the postoperative range of motion, the MD group had more abduction than the LD group (MD: 136.28°, 95% CI 127.36-145.20; LD: 127.77° 95% CI 117.02-138.52). Both designs had a comparable improvement in the Constant Murley score (MD 42.04 points, LD 41.14 points). Lowering the NSA was accompanied by a decrease in dislocation rate (MD: 4.6%; LD: 1.4%; P value .037) and notching rate (MD: 40.3%; LD: 17.3%; P value <.0001).

Conclusion

In our analysis, lowering the NSA decreases the amount of abduction but increases the amount of external rotation. This change in range of motion is accompanied by less scapular notching and dislocations. There is no clear impact on functional outcome measures.

Treating cuff tear arthropathy by reverse total shoulder arthroplasty: do the inclination of the humeral component and the lateral offset of the glenosphere influence the clinical and the radiological outcome?

PURPOSE

Reverse total shoulder arthroplasty is widely used for the treatment of cuff tear arthropathy. Standard implants consist of a humeral component with an inclination angle of 155° and a glenosphere without lateral offset. Recently, lower inclination angles of the humeral component as well as lateralized glenospheres are implanted to provide better rotation of the arm and to decrease the rate of scapular notching. This study investigates the clinical and radiological results of a standard reverse total shoulder in comparison with an implant with an inclination angle of 135° in combination with a 4 mm lateralized glenosphere in context of cuff tear arthropathy.

MATERIAL AND METHODS

For this retrospective comparative analysis 42 patients treated by reverse total shoulder arthroplasty for cuff tear arthropathy were included. Twenty-one patients (m = 11, f = 10; mean age 76 years; mean follow-up 42 months) were treated with a standard 155° humeral component and a standard glenosphere with caudal eccentricity (group A), while twenty-one patients (m = 5, f = 16; mean age 72 years; mean follow-up 34 months) were treated with a 135° humeral component and 4 mm lateral offset of the glenosphere (group B). At follow-up patients of both groups were assessed with plain X-rays (a.p. and axial view), Constant Score, adjusted Constant Score, the subjective shoulder value and the range of motion.

RESULTS

The clinical results were similar in both groups concerning the Constant Score (group A = 56.3 vs. group B = 56.1; p = 0.733), the adjusted CS (group A = 70.4% vs. group B = 68.3%; p = 0.589) and the SSV (group A = 72.0% vs. group B = 75.2%; p = 0.947). The range of motion of the operated shoulders did not differ significantly between group A and group B: Abduction = 98° versus 97.9°, p = 0.655; external rotation with the arm at side = 17.9° versus 18.7°, p = 0.703; external rotation with the arm positioned in 90° of abduction = 22.3° versus 24.7°, p = 0.524; forward flexion = 116.1° versus 116.7°, p = 0.760. The rate of scapular notching was higher (p = 0.013) in group A (overall: 66%, grade 1: 29%, grade 2: 29%, grade 3: 10%, grade 4: 0%) in comparison to group B (overall: 33%, grade 1: 33%, grade 2: 0%, grade 3: 0%, grade 4: 0%). Radiolucency around the humeral component was detected in two patients of group B. Stress shielding at the proximal humerus was observed in six patients of Group A (29%; cortical thinning and osteopenia in zone M1 and L1) and two patients of group B (10%; cortical thinning and osteopenia in zone M1 and L1). Calcifications of the triceps origin were observed in both groups (group A = 48% vs. group B = 38%).

CONCLUSION

Theoretically, a lower inclination angle of the humeral component and an increased lateral offset of the glenosphere lead to improved impingement-free range of motion and a decreased rate of scapular notching, when compared to a standard reverse total shoulder implant. This study compared two different designs of numerous options concerning the humeral component and the glenosphere. In comparison to a standard-fashioned implant with a humeral inclination of 155° and a standard glenosphere, implants with a humeral inclination angle of 135° and a 4 mm lateralized glenosphere lead to comparable clinical results and rotatory function, while the rate of scapular notching is decreased by almost 50%. While the different implant designs did not affect the clinical outcome, our results indicate that a combination of a lower inclination angle of the humeral component and lateralized glenosphere should be favored to reduce scapular notching.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Factors Influencing Appropriate Implant Selection and Position in Reverse Total Shoulder Arthroplasty

Reverse shoulder arthroplasty has increased in popularity and has provided improved but somewhat variable results. These variable outcomes may be related to many factors, including implant design, component positioning, specific indication, and patient anatomy. The original Grammont design provided a solution to the high failure rate at the time but was found to have a high rate of scapular notching and poor restoration of rotation. Modern lateralized designs are more consistent in reducing scapular notching while improving range of motion, especially in regards to external rotation. This review article summarizes the effects of modern reverse shoulder prostheses on outcomes.

In vivo measurement of distance between scapular neck and polyethylene insert during active external rotation in shoulders with Grammont type reverse prosthesis

BACKGROUND

Scapular notching is a frequently observed complication after reverse shoulder arthroplasty. Impingement of the humeral plastic insert against the scapular neck is believed to be the cause of notching. There have been no in vivo studies that analyzed the positional relationship between the scapular neck and humeral insert. The purpose of this study was to measure the distance between the scapular neck and insert in shoulders with Grammont-type prostheses during active external rotation at the side.

METHODS

Eighteen shoulders with Grammont-type prostheses were enrolled in this study. There were 13 males and 5 females, and the mean age at surgery was 74 years (range, 63-91). Fluoroscopic images were recorded during active external rotation at the side from maximum internal to external rotation at an average of 14 months (range, 7-24) after surgery. Implant kinematics were determined with three-dimensional models of the implants and fluoroscopic images using model-image registration techniques. Based on the implant kinematics, the closest distance between the scapular neck and insert was computed at each 5° increment of glenohumeral internal/external rotation.

RESULTS

Mean glenohumeral abduction during rotation was 17°-22°. The mean distance between the neck and insert was approximately 1 mm throughout the activity. The separation distance tended to narrow with arm external rotation, but the change was not significant.

INTERPRETATION

The small distance between the scapular neck and insert in early post-operative reverse shoulder arthroplasty patients may be associated with the high incidence of scapular notching in Grammont-type prostheses.

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

Background

Globally, reverse shoulder arthroplasty (RSA) has moved away from the Grammont design to modern prosthesis designs. The purpose of this study was to provide a focused, updated systematic review for each of the most common complications of RSA by limiting each search to publications after 2010. In this part II, the following were examined: (1) instability, (2) humerus/glenoid fracture, (3) acromial/scapular spine fractures (AF/SSF), and (4) problems/miscellaneous.

Methods

Four separate PubMed database searches were performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Overall, 137 studies for instability, 94 for humerus/glenoid fracture, 120 for AF/SSF, and 74 for problems/miscellaneous were included in each review, respectively. Univariate analysis was performed with chi-square and Fisher exact tests.

Results

The Grammont design had a higher instability rate vs. all other designs combined (4.0%, 1.3%; P < .001), and the onlay humerus design had a lower rate than the lateralized glenoid design (0.9%, 2.0%; P = .02). The rate for intraoperative humerus fracture was 1.8%; intraoperative glenoid fracture, 0.3%; postoperative humerus fracture, 1.2%; and postoperative glenoid fracture, 0.1%. The rate of AF/SSF was 2.6% (371/14235). The rate for complex regional pain syndrome was 0.4%; deltoid injury, 0.1%; hematoma, 0.3%; and heterotopic ossification, 0.8%.

Conclusions

Focused systematic reviews of recent literature with a large volume of shoulders demonstrate that using non-Grammont modern prosthesis designs, complications including instability, intraoperative humerus and glenoid fractures, and hematoma are significantly reduced compared with previous studies. As the indications continue to expand for RSA, it is imperative to accurately track the rate and types of complications in order to justify its cost and increased indications.

A systematic review of tuberosity healing and outcomes following reverse shoulder arthroplasty for fracture according to humeral inclination of the prosthesis

BACKGROUND

Proximal humerus fractures are common in the elderly population and are often treated with reverse shoulder arthroplasty (RSA). The purpose of this systematic review was to compare tuberosity healing and functional outcomes in patients undergoing RSA with humeral inclinations of 135°, 145°, and 155°.

METHODS

A systematic review was performed of RSA for proximal humerus fracture using Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines. Radiographic and functional outcome data were extracted to evaluate tuberosity healing according to humeral inclination. Analysis was also performed of healed vs. nonhealed tuberosities.

RESULTS

A total of 873 patients in 21 studies were included in the analysis. The mean age was 77.5 years (range of 58-97) and the mean follow-up was 26.2 months. Tuberosity healing was 83% in the 135° group compared with 69% in the 145° group and 66% in the 155° group (P = .030). Postoperative abduction was highest in the 155° group (P < .001). No significant difference was found in forward flexion, external rotation, or postoperative Constant score between groups. Patients with tuberosity healing demonstrated 18° higher forward flexion (P = .008) and 16° greater external rotation (P < .001) than those with unhealed tuberosities.

CONCLUSION

RSA for fracture with 135° humeral inclination is associated with higher tuberosity healing rates compared with 145° or 155°. Postoperative abduction is highest with a 155° implant, but there is no difference in in postoperative forward flexion, external rotation, or Constant score according to humeral inclination. Patients with healed tuberosities have superior postoperative forward flexion and external rotation than those with unhealed tuberosities.

Clinical Importance of Graft Integrity in Arthroscopic Superior Capsular Reconstruction Using a Minimally Invasively Harvested Midthigh Fascia Lata Autograft: 3-Year Clinical and Magnetic Resonance Imaging Outcomes

BACKGROUND

The clinical importance of graft type and integrity in arthroscopic superior capsular reconstruction (ASCR) remains controversial.

PURPOSE

To assess 3-year clinical and magnetic resonance imaging (MRI) outcomes of ASCR using a minimally invasively harvested fascia lata autograft (FLA) for irreparable rotator cuff tears (IRCTs) and to determine the clinical importance of graft integrity and whether the results change from year 2 to 3.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 22 consecutive patients who underwent ASCR with a minimally invasively harvested FLA were enrolled in a prospective single-arm study. At 3 years, the patients answered a satisfaction questionnaire and underwent a clinical examination and MRI. The MRI scans were independently reviewed by 3 raters to determine the graft integrity, acromiohumeral interval, supraspinatus atrophy, and fatty degeneration of the rotator cuff muscles. Reliability statistics were calculated, and the outcomes were compared across subgroups of patients with and without complete graft tears.

RESULTS

Overall, 21 patients (95.5%) answered the questionnaire, 20/21 (95.2%) were satisfied, 4/20 (20.0%) reported donor site pain, and 19 patients (86.4%) underwent examinations. From preoperatively to 3 years, the mean improvement was 73.68° in elevation (95% CI, 47.59°-99.77°), 89.21° in abduction (95% CI, 66.56°-111.86°), 24.74° in external rotation (95% CI, 4.72°-34.75°), 3.00 in internal rotation (95% CI, 2.36-3.64), 2.61 kg in abduction strength (95% CI, 1.76-3.45 kg), 50.79 on the Constant score (CS; 95% CI, 41.99-59.58), 7.47 on the Simple Shoulder Test (SST; 95% CI, 5.19-9.75), and 36.05% on the subjective shoulder value (SSV; 95% CI, 23.19%-48.92%), which were all significant (P < .05). From 2 to 3 years, the mean improvement in abduction was 20.26° (95% CI, 5.44°-35.09°), which was significant (P = .010). At 3 years, the raters perfectly agreed (kappa = 1; P = .000013) that 4 patients (21.1%) had complete graft tears; this subgroup of patients had decreased external rotation strength at 90° of abduction (1.77 ± 0.17 vs 4.45 ± 2.55 kg, respectively; P = .027) and increased grades of infraspinatus (3.50 ± 0.58 vs 2.20 ± 1.01, respectively; P = .030) and teres minor fatty degeneration (3.25 ± 0.96 vs 1.53 ± 0.64, respectively; P = .005) compared with those without a complete graft tear, but the mean CS, SST, and SSV scores did not differ from those of the overall group (69.50 ± 5.20 vs 69.63 ± 18.25; 9.00 ± 2.31 vs 9.74 ± 4.73; and 72.50 ± 15.00 vs 71.58 ± 26.70, respectively).

CONCLUSION

The 3-year clinical outcomes of ASCR using a minimally invasively harvested FLA for IRCTs were good, despite donor site morbidity. Active abduction improved significantly from 2 to 3 years. Complete graft tears were correlated with significantly decreased external rotation strength at 90° of shoulder abduction and increased grades of infraspinatus and teres minor fatty degeneration.

REGISTRATION

NCT03663036 (ClinicalTrials.gov identifier).

Outpatient vs. inpatient reverse total shoulder arthroplasty: outcomes and complications

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) is an effective treatment option for many shoulder conditions. Historically, this surgical procedure was performed on an inpatient basis. There has been a recent trend to perform RTSA on an outpatient basis in proper candidates.

METHODS

All patients who underwent outpatient RTSA performed by a single surgeon between 2015 and 2017 were included. Demographic information and clinical outcome scores (American Shoulder and Elbow Surgeons, visual analog scale, and Single Assessment Numeric Evaluation scores), as well as data on complications, readmission, and revision surgery, were recorded. This group of patients was then compared with a cohort of patients who underwent RTSA in the inpatient setting during the same period.

RESULTS

Overall, 241 patients (average age, 68.9 years; 52.3% female patients) underwent outpatient RTSA and were included. Patients who underwent outpatient RTSA showed significant improvements in all clinical outcome scores at both 1 and 2 year postoperatively (all P < .0001). The control group of patients who underwent RTSA as inpatients consisted of 373 patients (average age, 72 years; 66% female patients). Significantly more controls had diabetes (P = .007), and controls had a higher body mass index (P = .022). No significant differences existed in improvements in clinical outcome scores between the inpatient and outpatient groups. Complication rates were significantly lower for outpatient cases than for inpatient controls (7.0% vs. 12.7%, P = .023).

CONCLUSION

RTSA performed in an outpatient setting is a safe and reliable procedure that provides significant improvements in clinical outcome scores with fewer complications compared with inpatient RTSA.

Shoulder replacement surgery for osteoarthritis and rotator cuff tear arthropathy

BACKGROUND

Shoulder replacement surgery is an established treatment for patients with end-stage glenohumeral osteoarthritis or rotator cuff tear arthropathy who have not improved with non-operative treatment. Different types of shoulder replacement are commonly used, but their relative benefits and risks compared versus one another and versus other treatments are uncertain. This expanded scope review is an update of a Cochrane Review first published in 2010.

OBJECTIVES

To determine the benefits and harms of shoulder replacement surgery in adults with osteoarthritis (OA) of the shoulder, including rotator cuff tear arthropathy (RCTA).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, SportDiscus, and Web of Science up to January 2019. We also searched clinical trial registers, conference proceedings, and reference lists from previous systematic reviews and included studies.

SELECTION CRITERIA

We included randomised studies comparing any type of shoulder replacement surgery versus any other surgical or non-surgical treatment, no treatment, or placebo. We also included randomised studies comparing any type of shoulder replacement or technique versus another. Study participants were adults with osteoarthritis of the glenohumeral joint or rotator cuff tear arthropathy. We assessed the following major outcomes: pain, function, participant-rated global assessment of treatment success, quality of life, adverse events, serious adverse events, and risk of revision or re-operation or treatment failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We collected trial data on benefits and harms.

MAIN RESULTS

We included 20 studies involving 1083 participants (1105 shoulders). We found five studies comparing one type of shoulder replacement surgery to another type of shoulder replacement surgery, including three studies comparing conventional stemmed total shoulder replacement (TSR) surgery to stemmed humeral hemiarthroplasty. The remaining 15 studies compared one type of shoulder replacement to the same type of replacement performed with a technical modification or a different prosthetic component. We found no studies comparing shoulder replacement surgery to any other type of surgical treatment or to any type of non-surgical treatment. We found no studies comparing reverse total shoulder replacement surgery to any other type of treatment or to any type of replacement. Trial size varied from 16 to 161 participants. Participant mean age ranged from 63 to 81 years. 47% of participants were male. Sixteen trials reported participants with a diagnosis of osteoarthritis and intact rotator cuff tendons. Four trials reported patients with osteoarthritis and a rotator cuff tear or rotator cuff tear arthropathy. All studies were at unclear or high risk of bias for at least two domains, and only one study was free from high risk of bias (included in the main comparison). The most common sources of bias were lack of blinding of participants and assessors, attrition, and major baseline imbalance. Three studies allowed a comparison of conventional stemmed TSR surgery versus stemmed humeral hemiarthroplasty in people with osteoarthritis. At two years, low-quality evidence from two trials (downgraded for bias and imprecision) suggested there may be a small but clinically uncertain improvement in pain and function. On a scale of 0 to 10 (0 is no pain), mean pain was 2.78 points after stemmed humeral hemiarthroplasty and 1.49 points lower (0.1 lower to 2.88 lower) after conventional stemmed TSR. On a scale of 0 to 100 (100 = normal function), the mean function score was 72.8 points after stemmed humeral hemiarthroplasty and 10.57 points higher (2.11 higher to 19.02 higher) after conventional stemmed TSR. There may be no difference in quality of life based on low-quality evidence, downgraded for risk of bias and imprecision. On a scale of 0 to 100 (100 = normal), mean mental quality of life was rated as 57.4 points after stemmed humeral hemiarthroplasty and 1.0 point higher (5.1 lower to 7.1 higher) after conventional stemmed TSR. We are uncertain whether there is any difference in the rate of adverse events or the rate of revision, re-operation, or treatment failure based on very low-quality evidence (downgraded three levels for risk of bias and serious imprecision). The rate of any adverse event following stemmed humeral hemiarthroplasty was 286 per 1000, and following conventional stemmed TSR 143 per 1000, for an absolute difference of 14% fewer events (25% fewer to 21% more). Adverse events included fractures, dislocations, infections, and rotator cuff failure. The rate of revision, re-operation, or treatment failure was 103 per 1000, and following conventional stemmed TSR 77 per 1000, for an absolute difference of 2.6% fewer events (8% fewer to 15% more). Participant-rated global assessment of treatment success was not reported.

AUTHORS' CONCLUSIONS

Although it is an established procedure, no high-quality randomised trials have been conducted to determine whether shoulder replacement might be more effective than other treatments for osteoarthritis or rotator cuff tear arthropathy of the shoulder. We remain uncertain about which type or technique of shoulder replacement surgery is most effective in different situations. When humeral hemiarthroplasty was compared to TSR surgery for osteoarthritis, low-quality evidence led to uncertainty about whether there is a clinically important benefit for patient-reported pain or function and suggested there may be little or no difference in quality of life. Evidence is insufficient to show whether TSR is associated with greater or less risk of harm than humeral hemiarthroplasty. Available randomised studies did not provide sufficient data to reliably inform conclusions about adverse events and harm. Although reverse TSR is now the most commonly performed type of shoulder replacement, we found no studies comparing reverse TSR to any other type of treatment.

Reverse Total Shoulder Arthroplasty: Implant Design Considerations

PURPOSE OF REVIEW

Our understanding of the reverse total shoulder arthroplasty (RTSA) has grown exponentially since Grammont first introduced his design in 1985. There are a multitude of implant-related variables to consider when performing RTSA. The purpose of this article is to provide a review of these design considerations.

RECENT FINDINGS

Current literature demonstrates that the traditional Grammont prosthesis has over 90% survivorship at 10 years. Despite these promising results, there have been concerns raised over the significant rate of scapular notching observed. As a result, the traditional RTSA design has been modified to minimize this complication and maximize impingement-free motion. Modern RTSA designs with a cementless, curved, short-stemmed eccentric onlay humeral component combined with a large, lateralized glenosphere placed in 10° of inferior tilt with > 3.5 mm of inferior overhang have been found to provide excellent results. However, all implant design features must be considered on a case-by-case basis to optimize outcome for each patient. Humeral and glenoid implant design variables have evolved as the biomechanics of RTSA have been further elucidated. Consideration of these variables allows the surgeon to maximize joint efficiency, improve impingement-free range of motion, decrease the risk of scapular notching, preserve bone stock, and minimize the risk of instability.