Outcomes of reverse vs anatomic total shoulder arthroplasty in glenohumeral osteoarthritis without rotator cuff deficiency: A meta-analysis

Abstract

BACKGROUND

The optimal surgical approach for patients with primary glenohumeral osteoarthritis (GHOA) and an intact rotator cuff remains debated. While anatomic total shoulder arthroplasty (TSA) has traditionally been favoured, reverse TSA (RTSA) is increasingly utilized.

AIM

To systematically compare the outcomes of RTSA and TSA in this specific patient population.

METHODS

A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. Retrospective comparative studies evaluating RTSA and TSA in patients with GHOA and intact rotator cuff were included. Key outcomes assessed included complication and reoperation rates, patient-reported outcome measures (PROMs), and range of motion. Risk of bias was assessed using the Risk of Bias in Non-randomized Studies of Interventions tool.

RESULTS

Twelve studies encompassing 1608 patients (580 RTSA, 1028 TSA) met inclusion criteria. RTSA was associated with a lower reoperation rate compared to TSA [odds ratio = 0.37; 95% confidence interval (CI): 0.14-0.94; P value = 0.04], while no significant difference in overall complication rates was observed (odds ratio = 0.47; 95%CI: 0.19-1.16; P value = 0.10). RTSA patients showed superior outcomes in University of California Los Angeles, Simple Shoulder Test, and Shoulder Pain and Disability Index scores; however, the differences did not exceed the minimal clinically important difference. TSA patients had significantly better external rotation (mean difference= -9.0°; 95%CI: -13.21 to -5.02; P value < 0.0001). No significant differences were found in other range of motion measures or satisfaction scores. The overall methodological quality of included studies was moderate to serious.

CONCLUSION

In patients with GHOA and an intact rotator cuff, RTSA may offer comparable or improved outcomes to TSA with lower reoperation rates and similar complication profiles. Functional outcomes favour RTSA in certain patient-reported outcome measures, while TSA retains an advantage in external rotation. Surgical decision-making should remain individualized based on patient characteristics and functional demands.

Key Words: Reverse shoulder arthroplasty; Total shoulder arthroplasty; Glenohumeral osteoarthritis; Intact rotator cuff; Meta-analysis

Core Tip: This systematic review and meta-analysis compares reverse total shoulder arthroplasty (RTSA) and total shoulder arthroplasty (TSA) in patients with primary glenohumeral osteoarthritis and an intact rotator cuff. Analyzing 1608 patients across 12 studies, we found RTSA was associated with lower reoperation rates and similar complication profiles compared to TSA. While TSA demonstrated better external rotation, RTSA showed favourable patient-reported outcomes, though most did not exceed clinical relevance thresholds. These findings support RTSA as a viable alternative in select patients, challenging traditional treatment paradigms and guiding individualized surgical decision-making.

INTRODUCTION

Anatomic total shoulder arthroplasty (TSA) and reverse TSA (RTSA) have become increasingly common surgical options for managing primary glenohumeral osteoarthritis (GHOA). Both procedures have shown efficacy in alleviating pain and improving shoulder function[1]. Traditionally, the choice between TSA and RSA has largely depended on the condition of the rotator cuff[2,3]. A deficient rotator cuff can lead to biomechanical dysfunction, including superior migration of the humeral head, which negatively affects joint mechanics and increases stress on implant components. This stress may manifest as edge loading and glenoid component wear, commonly referred to as the “rocking-horse phenomenon”[4,5].

Long-term outcomes have raised concerns regarding the durability of TSA in the context of rotator cuff integrity. For instance, secondary rotator cuff dysfunction has been observed in a significant proportion of patients following TSA[6,7]. One study reported a 16.8% incidence of such dysfunction at an average of 8.6 years postoperatively, which correlated with both poorer clinical outcomes and adverse radiographic findings[8]. Consequently, rotator cuff failure remains a leading cause of TSA revision.

Given these considerations, RTSA is often favoured in certain patient populations -particularly those with diminished tissue quality, advanced age, lower activity levels, or complex glenoid anatomy. However, identifying patients at high risk for poor outcomes following TSA remains challenging due to the subjective and variable nature of these risk factors. This uncertainty has contributed to an increasing trend toward selecting RTSA for GHOA even when the rotator cuff is intact, in an effort to reduce reliance on cuff functionality and avoid future complications.

Although RTSA is primarily approved for cases involving cuff tear arthropathy, its use has expanded to include primary GHOA in patients with preserved rotator cuffs. This shift in practice patterns has prompted ongoing debate regarding the relative benefits and risks of TSA vs RTSA in this context. The first comprehensive systematic review and meta-analysis on this topic, conducted by Kim et al[9] in 2022, included six studies comprising 447 patients with intact rotator cuffs that reported broadly equivalent functional outcomes, but with limited scope. In contrast, our study includes 12 studies encompassing over 1600 patients, integrates new outcome measures, and offers updated comparative data. This more comprehensive review aims to better inform clinical decision-making by evaluating not only complications and functional scores but also range of motion (ROM) and revision rates.

Since then, multiple new comparative studies have been published, offering conflicting evidence regarding complications, functional outcomes, and reoperation rates[3,10,11]. To synthesize this emerging evidence and inform clinical decision-making, we conducted an updated systematic review and meta-analysis focusing on patients with primary GHOA and intact rotator cuffs. Specifically, we sought to answer three key questions: (1) Which procedure is associated with a higher rate of perioperative complications? (2) Which offers superior postoperative patient-reported outcomes? and (3) Which results in better postoperative ROM?

MATERIALS AND METHODS

Search strategy

This meta-analysis was conducted in accordance with the PRISMA guidelines[12]. A comprehensive literature search was carried out across three major databases: PubMed, the Cochrane Library, and Google Scholar. The search conducted between January 2015 to December 2024 employed a combination of relevant keywords and Boolean operators, including “reverse”, “osteoarthritis”, “shoulder”, “arthroplasty”, and “replacement” to identify studies comparing RTSA with TSA in the setting of primary GHOA with an intact rotator cuff. Additional studies were identified by manually reviewing reference lists from selected articles and through targeted internet searches. Study selection was initially performed by one reviewer and subsequently verified by a second reviewer. The study selection process is illustrated in a PRISMA flow diagram (Figure 1).

Figure 1  PRISMA flow diagram illustrating the study selection process for inclusion in the meta-analysis.

Inclusion criteria consisted of comparative studies assessing RTSA vs TSA in patients with primary GHOA and intact rotator cuffs. Studies were excluded if they were non-comparative, utilized national databases (to minimize potential patient overlap), or involved additional surgical interventions alongside TSA, such as posterior capsular plication.

Data extraction

Two independent reviewers screened studies for eligibility and extracted relevant data. Extracted variables included adverse events (perioperative complications and reoperations), patient-reported outcome measures (PROMs) such as satisfaction, Visual Analog Scale (VAS), and Shoulder Pain and Disability Index (SPADI) - with higher scores indicating worse outcomes for VAS and SPADI - as well as the University of California Los Angeles (UCLA) score, American Shoulder and Elbow Surgeons (ASES) score, Constant Score (CS), and Simple Shoulder Test (SST), where higher scores indicate better function. ROM data were also collected, including external rotation (ER), internal rotation (IR), forward flexion, and abduction. Any discrepancies between the reviewers were resolved through discussion and consensus.

Risk of bias assessment

The risk of bias for non-randomized studies was evaluated using the Risk of Bias in Non-randomized Studies of Interventions tool by two reviewers independently[13]. Studies assessed as having a critical risk of bias were excluded from the analysis.

Statistical analysis

All statistical analyses were performed using Review Manager version 5.4 (The Cochrane Collaboration, London, United Kingdom). Continuous outcomes were analyzed using mean differences (MD) or standardized MD, each with 95% confidence interval (CI). Dichotomous outcomes were evaluated using odds ratios (OR). Heterogeneity among studies was assessed with the Q statistic and I² index. A random-effects model was applied when significant heterogeneity was present, while a fixed-effect model was used in cases of low heterogeneity. Additionally, the distribution of Walch glenoid classifications between TSA and RTSA groups was compared using χ² analysis via SPSS software version 25.0 (IBM Corp., Armonk, NY, United States). A P value of ≤ 0.05 was considered statistically significant.

RESULTS

Study characteristics

Twelve retrospective studies met the inclusion criteria[14-25], encompassing a total of 1608 patients - 580 in the RTSA group (36.06%) and 1028 in the TSA group (63.94%). The key characteristics of the included studies are presented in Table 1.

Table 1 Summary of included studies comparing reverse total shoulder arthroplasty and total shoulder arthroplasty.

Ref.	Study	Participants		Age (years)		Mean follow-up		Glenoid morphology		Adverse events
		RTSA	TSA	RTSA	TSA	RTSA	TSA	RTSA	TSA	RTSA	TSA
Ardebol et al[14], 2024	Retrospective	37	67	80	79	33 months	43 months	8 A14 A22 B123 B2/B3	28 A13 A221 B115 B2/B3	1 stiffness 1 acromial stress fracture	3 rotator cuff failure 2 stiffness
Haritinian et al[15], 2020	Retrospective	12	39	71	68	-		3 A11 A22 B16B2/B3	13 A16 A213 B17 B2/B3	-	-
Hones et al[16], 2024	Retrospective	60	60	72	70	3.7 years	4.0 years	-		-	-
Kim[17], 2024	Retrospective	26	41	75	76	45 months	39 months	16A15A24B11B2	31 A17A21B12B2	1 infection	1 rotator cuff tear with glenoid loosening
Kirsch et al[18], 2022	Retrospective	67	67	67		27 months	33 months	17 A17A24 B134 B2/B33C2D	25 A11A23B134B2/B33C1D	1 acromial stress fracture 1 glenoid fracture 1 radial nerve palsy	1 rotator cuff tear, 1 ulnar nerve palsy 1 hematoma
Mahylis et al[19], 2024	Retrospective	149	187	71	66	41 months	62 months	-		1 glenoid loosening	11 glenoid loosening 3 nonspecified
Merolla et al[20], 2020	Retrospective	36	47	72		2.4 years		-		2 diaphyseal fractures	1 rotator cuff tear
Polisetty et al[21], 2021	Retrospective	63	252	74	73	3.8 years		2A17A22B137B2/B32C13D	81 A147A214 B197B2/31C12D	-	5 rotator cuff tears (with 2 glenoid loosening) 1 infection with glenoid loosening 5 glenoid loosening
Steen et al[22], 2015	Retrospective	24	96	78	77	3.5 years		7A15A21B18B23C	28A120A24B132B212C	1 periprosthetic fracture	5 glenoid loosening
Trammell et al[23], 2023	Retrospective	64	64	72	68	3 years	5 years	-		1 component failure 1 glenoid fracture 2 periprosthetic fractures 2 intraoperative fractures	4 glenoid loosening 1 humeral loosening 1 humeral and glenoid loosening 1 component failure 3 infections 1 periprosthetic fracture 2 unexplained pain
Turnbull et al[24], 2024	Retrospective	9	46	71	67	-		-		1 glenoid fracture	6 glenoid loosening 2 component failures 1 glenoid and humeral loosening 1 infection1 glenoid fracture 1 periprosthetic fracture 1 unexplained pain
Wright et al[25], 2020	Retrospective	33	102	77		6 years		-		1 infection 1 fracture 1 nerve palsy 1 vascular injury	11 rotator cuff tears 2 fractures 1 recurrent dislocation

RTSA: Reverse total shoulder arthroplasty; TSA: Total shoulder arthroplasty.

All 12 studies reported data on patient age and follow-up duration. Patients undergoing RTSA were significantly older than those receiving TSA, with a MD of 1.73 years (95%CI: 0.48-2.99; P value = 0.007; Figure 2A). Additionally, the RTSA group had a significantly shorter follow-up duration by a mean of 8.83 months (95%CI: -15.93 to -1.74; P value = 0.01; Figure 2B).

Figure 2 Forest plots comparing mean age and follow-up duration between reverse total shoulder arthroplasty and total shoulder arthroplasty groups. A: Forest plot comparing mean age between patients undergoing reverse total shoulder arthroplasty (TSA) and TSA; B: Forest plot comparing follow-up duration between reverse TSA and TSA groups. CI: Confidence interval; RTSA: Reverse total shoulder arthroplasty; TSA: Total shoulder arthroplasty.

Eight studies (n = 888; 381 RTSA, 507 TSA) reported preoperative Walch glenoid classifications. A significant difference in glenoid morphology was observed between the groups. The TSA cohort predominantly exhibited type A glenoid, while the RTSA cohort demonstrated a greater prevalence of complex morphologies, including types B, C, and D (Table 2). These anatomical differences likely influenced surgical decision-making and may have impacted clinical outcomes.

Table 2 Distribution of preoperative glenoid morphology according to the Walch classification among patients receiving reverse total shoulder arthroplasty and total shoulder arthroplasty.

Walch type	RTSA (n = 381)	TSA (n = 507)
Type A1	53	206
Type A2	29	84
Type B1	15	66
Type B2/B3	108	175
Type C	8	16
Type D	15	13

RTSA: Reverse total shoulder arthroplasty; TSA: Total shoulder arthroplasty.

Subgroup analysis by glenoid morphology

A subgroup analysis was performed to evaluate the association between preoperative glenoid morphology and the likelihood of undergoing RTSA vs TSA. Patients with more complex glenoid types - specifically Walch types B2/B3 and D - were significantly more likely to receive RTSA compared to TSA. The pooled OR for undergoing RTSA in patients with type B2/B3 glenoid was 2.58 (95%CI: 1.80-3.69; P < 0.0001), and for type D glenoid was 1.88 (95%CI: 1.01-3.48; P = 0.04). No significant differences were observed for types A2, B1, or C (Figure 3).

Figure 3 Forest plot showing odds ratios for receiving reverse total shoulder arthroplasty vs total shoulder arthroplasty by Walch glenoid type. RTSA: Reverse total shoulder arthroplasty; TSA: Total shoulder arthroplasty.

Risk of bias assessment

Risk of bias was assessed using the Risk of Bias in Non-randomized Studies of Interventions tool. While no study was deemed to have a critical risk of bias necessitating exclusion, the overall methodological quality varied. Most studies exhibited moderate to serious risk of bias in at least one domain, particularly in confounding and outcome measurement. These limitations underscore the importance of interpreting pooled results with caution (Table 3).

Table 3 Risk of bias assessment for included studies using the Risk of Bias in Non-randomized Studies of Interventions tool.

Ref.	Bias due to confounding	Bias in selection of participants	Bias in classification of interventions	Bias due to deviations from intended interventions	Bias due to missing data	Bias in measurement of outcomes	Bias in selection of reported result	Overall risk of bias
Ardebol et al[14], 2024	Moderate	Low	Low	Low	Low	Low	Low	Low
Haritinian et al[15], 2020	Moderate	Moderate	Low	Low	Low	Moderate	Low	Moderate
Hones et al[16], 2024	Moderate	Low	Low	Low	Low	Low	Low	Low
Kim[17], 2024	Moderate	Low	Low	Low	Low	Low	Low	Low
Kirsch et al[18], 2022	Moderate	Low	Low	Low	Low	Moderate	Low	Moderate
Mahylis et al[19], 2024	Serious	Moderate	Low	Low	Low	Moderate	Moderate	Serious
Merolla et al[20], 2020	Serious	Moderate	Moderate	Low	Moderate	Moderate	Low	Serious
Polisetty et al[21], 2021	Moderate	Low	Low	Low	Low	Low	Low	Low
Steen et al[22], 2015	Moderate	Low	Low	Low	Low	Low	Low	Low
Trammell et al[23], 2023	Moderate	Low	Low	Low	Moderate	Moderate	Moderate	Moderate
Turnbull et al[24], 2024	Moderate	Low	Moderate	Low	Moderate	Moderate	Low	Moderate
Wright et al[25], 2020	Serious	Low	Low	Low	Moderate	Moderate	Moderate	Serious

Low: Comparable to a well-performed randomized trial; Moderate: Sound for a non-randomized study but not comparable to a high-quality randomised control trial; Serious: Important problems in design or execution.

Adverse events

Complication rates: Ten studies (n = 1477; 508 RTSA, 969 TSA) reported data on complications (Table 4). The pooled analysis demonstrated no statistically significant difference in complication rates between the RTSA and TSA groups (OR = 0.47; 95%CI: 0.19-1.16; P value = 0.10). While the point estimate favoured RTSA, the CI crossed the line of no effect. Moderate heterogeneity was noted (I² = 58%) (Figure 4A).

Figure 4 Forest plots comparing complications, reoperations, functional scores, and patient satisfaction between reverse total shoulder arthroplasty and total shoulder arthroplasty. A: Forest plot comparing complication rates between reverse total shoulder arthroplasty (RTSA) and total shoulder arthroplasty (TSA); B: Forest plot comparing reoperation rates between RTSA and TSA; C: Forest plot comparing Shoulder Pain and Disability Index scores postoperatively between RTSA and TSA; D: Forest plot comparing University of California Los Angeles scores between RTSA and TSA; E: Forest plot comparing Simple Shoulder Test scores between RTSA and TSA; F: Forest plot comparing patient satisfaction rates between RTSA and TSA; G: Forest plot comparing Visual Analog Scale pain scores between RTSA and TSA; H: Forest plot comparing American Shoulder and Elbow Surgeons scores between RTSA and TSA; I: Forest plot comparing Constant Scores between RTSA and TSA. CI: Confidence interval; RTSA: Reverse total shoulder arthroplasty; TSA: Total shoulder arthroplasty.

Table 4 Summary of reported complications for reverse total shoulder arthroplasty and total shoulder arthroplasty cohorts.

Complication	RTSA	%	TSA	%
Glenoid-related
Glenoid fracture	3	0.5%	1	0.1%
Glenoid loosening	1	0.2%	37	3.6%
Dislocation	-	-	1	0.1%
Humeral-related
Humeral loosening	-	0.0%	3	0.3%
Diaphyseal fracture	3	0.5%	-	-
Periprosthetic fracture	3	0.5%	2	0.2%
Unspecified fractures	-	-	2	0.2%
Intraoperative fractures	2	0.3%	-	-
Rotator cuff/soft tissue
Rotator cuff tear/failure	-	-	22	2.1%
Acromial stress fracture	2	0.3%	-	-
Stiffness	1	0.2%	2	0.2%
Neurologic/vascular
Nerve palsy	2	0.3%	1	0.1%
Vascular injury	1	0.2%	1	0.1%
Infectious
Infection	1	0.2%	5	0.5%
PJI	3	0.5%	3	0.3%
Hematoma	-	-	1	0.1%
Implant-related
Component failure	1	0.2%	3	0.3%
Broken baseplate screw	1	0.2%	-	-
Other/unexplained
Unexplained pain	1	0.2%	3	0.3%
Total complications	28	4.8%	103	10.0%

RTSA: Reverse total shoulder arthroplasty; TSA: Total shoulder arthroplasty; PJI: Prosthetic joint infection.

Reoperation rates: The same ten studies also reported reoperation rates. RTSA was associated with significantly lower odds of reoperation compared to TSA (OR = 0.37; 95%CI: 0.14-0.94; P value = 0.04), with low between-study heterogeneity (I² = 22%) (Figure 4B).

Functional outcomes

Four studies (n = 639; 282 RTSA, 357 TSA) reported SPADI and UCLA scores, while five studies (n = 759; 306 RTSA, 453 TSA) reported SST scores. Compared to TSA, the RTSA group showed: Lower SPADI scores (MD = -7.21; 95%CI: -14.10 to -0.33; P = 0.04) (Figure 4C), Higher UCLA scores (MD = 3.13; 95%CI: 0.90-5.36; P = 0.006) (Figure 4D), and Higher SST scores (MD = 0.65; 95%CI: 0.03-1.28; P = 0.04) (Figure 4E). No significant differences were observed between groups in patient satisfaction (Figure 4F), VAS (Figure 4G), ASES (Figure 4H), or CS (Figure 4I).

ROM

Ten studies (n = 1430; 511 RTSA, 919 TSA) reported ROM data: ER was significantly reduced in the RTSA group (MD = -9.0°; 95%CI: -13.21 to -5.02; P value < 0.0001) (Figure 5A). No statistically significant differences were observed in: IR (MD = -0.15; 95%CI: -0.96 to 0.66; P value = 0.72) (Figure 5B), flexion (MD = -0.43; 95%CI: -7.85 to 6.99; P value = 0.91) (Figure 5C), and abduction (MD = 1.19; 95%CI: -8.99 to 11.37; P value = 0.82) (Figure 5D).

Figure 5 Forest plot comparing postoperative range of motion between reverse total shoulder arthroplasty and total shoulder arthroplasty. A: External rotation; B: Internal rotation; C: Flexion; D: Abduction. CI: Confidence interval; RTSA: Reverse total shoulder arthroplasty; TSA: Total shoulder arthroplasty.

DISCUSSION

As RTSA gains popularity and its indications expand, particularly in cases of GHOA with an intact rotator cuff, its comparative efficacy vs TSA warrants thorough evaluation. Historically, TSA has been the standard treatment in such cases; however, emerging literature supports RTSA as a viable alternative. This meta-analysis, comprising 12 comparative studies, provides new insights by demonstrating that RTSA is associated with lower rates of complications and reoperations, along with better outcomes in select patient-reported measures, including UCLA, SST, and SPADI scores.

Selection bias is a key limitation, as the RTSA cohort was significantly older (MD = 1.73 years) and had a shorter follow-up duration (MD = -8.83 months). These factors may have influenced outcomes such as complication and reoperation rates. Specifically, the lower reoperation rate observed in RTSA (OR = 0.37; P = 0.04) must be interpreted cautiously, as longer follow-up in the TSA group could allow more time for adverse events to accumulate. Prior literature, including work by Valsamis et al[26], suggests that differences in revision rates may diminish over extended follow-up periods - an important consideration not fully addressed in prior analyses.

Additionally, confounding due to glenoid morphology is another important factor. Table 2 highlights that TSA patients had a higher prevalence of Walch type A glenoid, whereas RTSA patients presented with more complex morphologies (types B2, B3, and D). These anatomical differences likely influenced surgical selection and may independently impact outcomes such as ROM and implant longevity. A subgroup analysis or meta-regression would help determine the independent effect of glenoid type on clinical outcomes.

Despite patients in the TSA group being, on average, younger, they experienced a higher incidence of complications and reoperations. These findings differ from those reported by Kim et al[9], who included fewer studies and incorporated one comparing TSA with posterior capsular plication - potentially introducing heterogeneity in their analysis.

Several factors may contribute to the observed differences in adverse events. One such factor is the evolving perception and application of RTSA. Historically viewed as a salvage option, RTSA is now increasingly used as a primary intervention for GHOA. This shift may alter revision thresholds and affect complication reporting. Notably, glenoid loosening and rotator cuff failure were among the most frequent complications in TSA, while RTSA's design, which relies on the deltoid rather than the rotator cuff, may inherently reduce the likelihood of such failures.

However, the longer mean follow-up duration in TSA patients (approximately 9 months more) could potentially bias comparisons of complication and revision rates. Moreover, the relatively short overall follow-up period limits conclusions regarding long-term outcomes. Prior studies, such as that by Valsamis et al[26], have indicated that differences in revision rates between RTSA and TSA may diminish with extended follow-up.

Regarding PROMs, RTSA was associated with significantly better SPADI, SST, and UCLA scores. However, caution is warranted in interpreting these differences. The improvements, although statistically significant, did not exceed the minimal clinically important differences for these scales - suggesting that the observed differences may not be clinically meaningful. Furthermore, these findings were based on a smaller subset of the included studies, whereas more commonly reported measures such as ASES and CSs showed no significant differences between groups.

In terms of ROM, TSA was superior in ER, with a MD of 9 degree, which does exceed the established minimal clinically important difference and aligns with findings from previous research. This difference is likely due to the distinct biomechanical designs of the two prosthetic systems. Other motion parameters, including IR, forward flexion, and abduction, did not differ significantly between groups.

Strengths and limitations

This meta-analysis offers several strengths, including a comprehensive review of the literature and the inclusion of more studies than previous systematic reviews on this subject. Nonetheless, several limitations must be acknowledged.

First, the retrospective nature of the included studies introduces inherent risk of bias. Although risk of bias was assessed systematically, many studies demonstrated moderate to serious concerns, particularly in areas of confounding and outcome measurement. Additionally, the absence of granular data limited the ability to perform subgroup analyses based on key demographic or clinical variables such as age, sex, or comorbidities.

Second, relevant intraoperative variables - such as surgical time, blood loss, subscapularis management, and hospital stay - were inconsistently reported, precluding their inclusion in the analysis. Cost-effectiveness, another important consideration in surgical decision-making, was also not evaluated in the included literature.

Third, baseline differences in glenoid morphology were observed between groups, with the RTSA group exhibiting more complex configurations. This factor could influence both surgical technique and postoperative outcomes and represents a potential confounder that could not be adjusted for in the pooled analysis.

Lastly, the relatively short mean follow-up duration limits the ability to draw conclusions about long-term implant survival or functional outcomes. Longer-term studies are needed to determine whether the trends observed in this analysis persist over time.

CONCLUSION

Despite its limitations, this meta-analysis provides robust comparative evidence suggesting that RTSA may offer certain short-term advantages over TSA in the treatment of primary GHOA with an intact rotator cuff. These include lower complication and reoperation rates and improved outcomes on select PROMs. However, the choice between RTSA and TSA should remain individualized, taking into account patient-specific factors such as age, activity level, anatomical considerations, and surgical goals. Further high-quality, prospective research with long-term follow-up is essential to validate these findings and guide clinical decision-making.