Incidence and risk factors of pseudoparesis in massive rotator cuff tears: a systematic review and meta-analysis

Abstract

Background

Among patients with massive rotator cuff tears (MRCT), some present with minimal pain but an inability to actively elevate the shoulder beyond 90°, a condition that frequently impairs quality of life. Comprehensive analyses of the risk factors for pseudoparesis in MRCT are lacking, and the role of certain factors remains controversial. This systematic review and meta-analysis aimed to quantify the incidence of pseudoparesis in MRCT and to identify its associated risk factors.

Methods

This systematic review was conducted in strict accordance with the PRISMA guidelines. A comprehensive search of PubMed, Web of Science, Embase, and Cochrane Library databases was performed from their inception to July 20, 2025. We included all original human studies that reported the incidence of pseudoparesis and/or its associated factors in patients with MRCT. For continuous variables, pooled effect sizes were calculated as mean differences (MD) with 95% confidence intervals (CI), while for dichotomous variables, odds ratios (OR) with 95% CI were used.

Results

Twenty-four studies met the eligibility criteria. The pooled incidence of pseudoparesis among patients with MRCT was 24.6% (95% CI, 20.7% to 28.8%). Meta-analysis revealed that several factors were significantly associated with an increased risk of pseudoparesis: older age (MD 4.38, 95% CI 2.37 to 6.38; P < 0.0001), female sex (odds ratio [OR] 1.74, 95% CI 1.12 to 2.71; P = 0.0140), fatty infiltration of the subscapularis (SSC) (MD 0.72, 95% CI, 0.49–0.95; P < 0.0001), greater critical shoulder angle (CSA) (MD 1.68, 95% CI, 0.67–2.69; P = 0.0011), reduced acromiohumeral distance (AHD) (MD − 2.71, 95% CI, − 3.34 to − 2.07; P < 0.0001), and greater global tear extension on MRI (MD 52.74, 95% CI, 44.63–60.86; P < 0.0001). Qualitative synthesis from three studies additionally identified SSC tear as a significant risk factor.

Conclusion

The pooled analysis revealed a pseudoparesis incidence of 24.6% in patients with MRCT. Significant risk factors associated with pseudoparesis included older age, fatty infiltration and tears of the SSC, greater CSA, reduced AHD, and larger global tear extension.

Systematic review registration This systematic review was registered in PROSPERO (CRD420251110594).

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12891-026-10098-3.

Introduction

Rotator cuff tears (RCT) are a leading cause of shoulder pain and constitute one of the most prevalent conditions managed by orthopedic surgeons [46]. Typically, these tears demonstrate a propensity to enlarge over time. A tear is classified as massive when it exceeds 5 cm in the anteroposterior dimension or involves two or more tendons, accounting for approximately 40% of all RCTs [8, 12, 49]. Such tears may become irreparable due to tendon retraction, muscle atrophy, fatty infiltration, or an inability to reduce the tendon to its anatomical footprint [3, 7]. In some patients with massive rotator cuff tears (MRCT), there is minimal pain yet an inability to actively elevate the shoulder beyond 90°. This clinical presentation, characterized by preserved passive range of motion and absence of neurological impairment, is termed “pseudoparesis” [44]. However, many studies have conflated this term with “pseudoparalysis,” a concept initially described by Rossler in 1967 [38]. The definition of pseudoparalysis has historically been based on a variety of factors, including stiffness, loss of external rotation, degenerative changes, nerve injury, and pain [42]. In recent years, as terminology has become more standardized, a consensus has emerged among researchers. Pseudoparalysis is now more precisely defined as the presence of full passive range of motion with active forward flexion (AFF) limited to less than 45°. In contrast, pseudoparesis refers specifically to AFF limited to less than 90° despite full passive motion [36].

The reason why patients with similar MRCT patterns develop such different symptoms—from pseudoparesis to a pain-free shoulder—remains unclear [45]. To address this, recent research has focused on identifying risk factors for pseudoparesis in MRCT. Factors implicated in prior studies include older age [11, 45], female sex [11], fatty infiltration [15], reduced acromiohumeral distance (AHD) [13], and an increased critical shoulder angle (CSA) [13]. Nonetheless, inconsistencies exist in the literature; for instance, Wieser et al. [45] and Reddy et al. [36] did not find a significant association between CSA or female sex and the risk of developing pseudoparesis. Consequently, a comprehensive, synthesized analysis of pseudoparesis risk factors in MRCT is lacking, and the roles of several factors remain controversial. Clarifying these risk factors is crucial to guide pre-surgical decision-making and develop personalized treatment strategies. Therefore, the primary objectives of this meta-analysis to determine the incidence of pseudoparesis in MRCT and to identify its associated risk factors.

Methods

This systematic review was rigorously conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines and has been registered on the PROSPERO (No: CRD420251110594, available at https://www.crd.york.ac.uk/PROSPERO/view/CRD420251110594.).

Eligibility criteria

The inclusion criteria for this study were as follows: (1) studies involving patients with MRCT; (2) articles reporting the incidence of pseudoparesis and/or its associated risk factors; and (3) articles written in English. Exclusion criteria comprised (1) reviews, commentaries, conference abstracts, letters to the editor; animal or cadaveric studies; (2) biomechanical or computational simulation studies; and (3) studies with sample sizes smaller than 10 cases.

Literature search and search strategy

A comprehensive and systematic literature search was performed across PubMed, the Cochrane Library, Embase, and Web of Science from their inception to July 20, 2025. The search strategy employed a combination of free-text keywords and controlled vocabulary terms (e.g., MeSH, Emtree) where applicable: “rotator cuff tear,” “rotator cuff injury,” “irreparable rotator cuff tears,” “chronic massive rotator cuff tears,” “massive rotator cuff tears,” “massive irreparable rotator cuff tears,” “pseudoparalysis,” and “pseudoparesis.” The full search strategy for each database is available in Supplementary Material 1. The initial screening of titles and abstracts was performed independently by two reviewers to identify potentially eligible studies. For records passing this initial screening, full-text articles were retrieved and independently assessed for final inclusion against the predefined eligibility criteria. To supplement the electronic database search, the reference lists of all included studies and relevant review articles were manually screened (i.e., bibliography checking) to identify any additional original studies that may have been missed by the electronic search.

Selection process and data extraction

Literature management was performed using EndNote X9 (Clarivate Analytics, Philadelphia, PA, USA). Two reviewers (H.Z. and Y.L.) independently screened the literature according to the predefined inclusion and exclusion criteria. All records retrieved from the database searches were initially screened based on their titles and abstracts. The full texts of potentially relevant articles were obtained for further eligibility assessment. Any disagreements were resolved through discussion between the reviewers, with arbitration by a senior author when necessary. Additionally, two investigators independently extracted data from the included studies. The extracted information encompassed the following: (1) Study characteristics: first author, publication year, country, and study design; (2) patient demographics: study population, number of patients, age, sex, and body mass index (BMI); and (3) Clinical parameters: prevalence of pseudoparesis, and identified risk factors.

Assessment of study quality

All studies meeting the inclusion criteria were independently assessed for risk of bias by two investigators using the Methodological Index for Non-Randomized Studies (MINORS) checklist. In cases of disagreement, the two reviewers discussed to reach a consensus, with a senior author consulted when necessary. The MINORS Checklist consists of 12 items, each scored as 0 (not reported), 1 (reported but inadequate), or 2 (reported and adequate). The maximum score for comparative studies is 24, while noncomparative studies have a maximum score of 16. Scores: 0–6 (very low), 7–10 (low), 11–15 (moderate), ≥ 16 (high quality). Interrater agreement between the two investigators was evaluated using Cohen’s kappa (κ) statistic. The strength of agreement was categorized into five levels based on κ values: slight (0–0.20), fair (0.21–0.40), moderate (0.41–0.60), substantial (0.61–0.80), and almost perfect (0.81–1.00).

Statistical analysis

For continuous variables, data are presented as mean ± standard deviation, and meta‑analysis results are reported as the mean difference (MD) with 95% confidence interval (CI). For binary categorical variables, data are expressed as frequencies and percentages, and meta‑analysis results are reported as the odds ratio (OR) with 95% CI. The primary meta-analysis estimated the pooled incidence proportion of pseudoparesis among patients with MRCT, along with its 95% CI. Heterogeneity was assessed by calculating the I² statistic, which estimates the proportion of variability in effect sizes attributable to between-study differences rather than to chance. An I² value below 70% was considered to indicate acceptable heterogeneity for common-effects models; higher values prompted the use of random-effects models. Subgroup analyses were conducted based on year of publication (≤ 2020 vs. >2020) and level of evidence (Level II/III vs. Level IV). The potential for publication bias was assessed both visually and statistically. A funnel plot was generated to visually inspect asymmetry, which may suggest publication bias or other small-study effects. Furthermore, when ten or more studies were included in a pooled analysis, Egger’s linear regression test was employed to formally assess funnel plot asymmetry. A P-value < 0.05 was considered statistically significant. All statistical analyses were performed using R software (version 4.4.1).

Results

Eligible studies and baseline characteristics

The initial database search yielded 642 records. After removal of duplicates, 319 unique records underwent title and abstract screening, resulting in the exclusion of 233 articles. The remaining 86 full-text articles were assessed for eligibility against the predefined criteria, culminating in the inclusion of 24 studies in the final systematic review and meta-analysis [1, 4, 5, 10, 11, 13–16, 19, 20, 22, 29, 31, 32, 34–36, 39, 40, 43, 45, 47, 48]. Manual screening of the reference lists of the included studies and relevant review articles did not identify any additional studies beyond those captured by the electronic database search. The article selection process is illustrated in Fig. 1.

Fig. 1.

Flowchart of the retrieval process according to PRISMA guidelines

A summary of the baseline characteristics included in the study is presented in Table 1. This systematic review incorporated data from 1,925 patients with MRCT, with a mean age of 64.50 years. Among them, 45.17% were female, and the mean BMI was 28.02 kg/m². The publication years of the included studies spanned from 2007 to 2025, with the majority (19 out of 24, 79.2%) published after 2020.

Table 1.

Summary characteristics of included studies

Author Year	Level of evidence	Country	Study population	Patients (n)	Age (Years)	BMI (kg/m2)	Gender (female, %)	Incidence of pseudoparesis (%)	Diagnosis methods	Risk factors	MINORS score
Baek 2024 [1]	Level IV	South Korea	MRCT with fatty infiltration beyond Goutallier stage 3	23	64.7 ± 5.9	24.0 ± 2.9	30.40%	6/23, 26.1%	AFF < 90° with full PE	NA	12
Besnard 2021 [4]	Level IV	France	MRCT	64	59.3 ± 8.4	NA	NA	17/64, 26.6%	AFF < 90° with full PE	Lower preoperative active forward elevation and lower preoperative shoulder strength	12
Boileau 2007 [5]	Level Ⅲ	France	MIRCT	68	68 ± 6	NA	62.00%	3/68, 4%	AFF < 90° with full PE	NA	18
Collin 2014 [10]	Level Ⅲ	France	MRCT with fatty infiltration beyond Goutallier stage 3	100	67.7 ± 8.2	NA	50.00%	32/100, 32%	AFF < 90° with full PE	Supraspinatus and complete subscapularis tears	17
Denard 2012 [11]	Level Ⅲ	USA	MRCT who underwent arthroscopic repair	127	60.36	NA	22.80%	24/127, 18.9%	AFF < 90° with full PE	Older age, female, complete infraspinatus tear, the anterior and posterior rotator cables were disrupted	18
Ernstbrunner 2020 [13]	Level Ⅲ	Switzerland	MRCT	100	68	NA	58.00%	50/246, 20.3%	AFF < 90° with full PE	Larger CSA, smaller AHD, higher PAH, greater tear extension, fatty infiltration of the subscapularis, rupture of the infraspinatus and teres minor muscles and the inferior half of the subscapularis	18
Ferrando 2021 [14]	Level IV	Spain and Ireland	MRCT who were treated with SCR	56	65 ± 9	NA	30.40%	11/56, 19.6%	AFF < 90° with full PE	NA	11
Fonseca 2025 [15]	Level Ⅲ	Brazil	Massive chronic atraumatic RCT	68	NA	NA	NA	14/71, 19.7%	AFF < 90° with full PE	The presence of a shoulder shrug sign, Goutallier grade III or IV fatty infiltration of the subscapularis, and a full-thickness tear of the subscapularis, higher VAS scores and a lower incidence of teres minor hypertrophy	15
Frantz 2023 [16]	Level Ⅲ	USA	MIRCT	98	61.5	NA	38.80%	12/98, 12.24%	AFF < 90° with full PE	NA	16
Gabig 2023 [19]	Level Ⅲ	USA	MRCT without GHOA	156	68	NA	30.00%	42/156, 26.9%	AFF < 90° with full PE	NA	18
Gonzalez-Morgado 2024 [20]	Level Ⅲ	USA	MRCT without GHOA and with fatty infiltration beyond Goutallier stage 3	81	68.24	NA	39.50%	25/81, 30.9%	AFF < 90° with full PE	NA	19
Gupta 2024 [22]	Level IV	Australia	MRCT	38	56.2 ± 6.2	30.5 ± 5.7	23.70%	7/43, 16.3%	AFF < 90° with full PE	NA	12
Lee 2021 [29]	Level IV	Korea or South Korea	MIRCT underwent SCR	11	66.3 ± 5.8	NA	36.30%	4/11, 36.3%	AFF < 90° with full PE	NA	14
Mihata 2018 [31]	Level IV	Japan	MIRCT underwent SCR	88	66.2	NA	NA	28/88, 31.82%	AFF < 90° with PE > 90°	NA	12
Misir 2021 [32]	Level Ⅲ	Turkey	MRCT underwent arthroscopic repair	312	59.5	27.1	59.60%	66, 21.15%	AFF < 90° with full PE	NA	19
Ozturk 2021 [34]	Level Ⅱ	Turkey	MIRCT	42	62.8	NA	65.00%	24/42, 57%	AFF < 90° with full PE	NA	21
Patel 2024 [35]	Level Ⅲ	USA	MIRCT underwent either MC or SCR	59	61.93	29.2	42.40%	14/59, 23.7%	AFF < 90° with full PE	NA	19
Reddy 2024 [36]	Level Ⅲ	USA	MIRCT	129	69.57	30	44.20%	45/129, 34.88%	AFF < 90° with full PE	Active forward elevation, tobacco use, supraspinatus fatty infiltration, subscapularis fatty infiltration, increased age, decreased AHD, severe glenohumeral osteoarthritis, and subscapularis tear	17
So 2024 [39]	Level Ⅲ	South Korea	MIRCT without GHOA underwent either SCR or RSA	64	72.13	25	75.00%	19/64, 29.7%	AFF < 90° with full PE	NA	19
Takayama 2021 [40]	Level Ⅲ	Japan	MIRCT or PPS who underwent SCR	54	69.93	NA	44.40%	16/54, 29.63%	AFF < 90° with PE > 90°	MRCT involving the inferior half of the SSC	18
Ulrich 2022 [43]	Level IV	USA	MIRCT underwent SCR	32	57.3	NA	12.50%	6/32, 18.8%	AFF < 90° with full PE	NA	10
Wieser 2015 [45]	Level Ⅲ	Switzerland	MRCT	20	72.6	NA	NA	9/20, 45%	AFF < 90° with full PE	Older age, lower constant score, lower anterior center-cuff angle, global tear extension in the anteroposterior plane, smaller acromiohumeral distance, subscapularis involvement, fatty infiltration of subscapularis.	15
Yao 2025 [47]	Level Ⅲ	USA	MRCT	105	64.0 ± 9.2	29.4 ± 5.5	38.00%	36/105, 34.3%	AFF < 90° with PE > 90°	SAM index and Initial trial of physical therapy	17
Yoon 2023 [48]	Level IV	Korea or South Korea	MIRCT underwent SCR	30	64.1 ± 8.7	NA	56.70%	7/30, 23.3%	AFF < 90° with full PE	NA	12

MRCT Massive rotator cuff tears, MIRCT Massive irreparable rotator cuff tears, SCR Superior capsular reconstruction, MC Margin convergence, RSA Reverse total shoulder arthroplasty, AFF Active forward flexion, PE Passive elevation, MINORS Methodological Index for Nonrandomized Studies, NA Not available, CSA Critical shoulder angle, AHD Acromiohumeral distance, PAH Posterior acromial height, SSC Subscapularis, VAS Visual analog scale, SAM Shoulder Abduction Moment Index, GHOA Glenohumeral osteoarthritis

Study quality

The methodological quality of the included studies was assessed using the MINORS criteria, and the scoring results are reported in Supplementary Table 1. Inter-rater reliability between the two independent assessors was excellent (Cohen’s κ = 0.86). For the included comparative studies, the mean MINORS score was 17.7 ± 1.57 (maximum 24), while noncomparative studies achieved a mean score of 11.88 ± 1.05 (maximum 16). The primary methodological limitations included failure to perform unbiased assessment of outcome measures, absence of a priori sample size calculation, insufficient evaluation of baseline comparability between groups, and lack of use of contemporary groups.

Incidence of pseudoparesis in patients with MRCT

This systematic review identified 24 studies reporting the incidence of pseudoparesis that were suitable for meta-analysis. The pooled incidence of pseudoparesis among patients with MRCT was 24.6% (95% CI, 20.7%–28.8%) (Fig. 2). Assessment of publication bias for the primary outcome included 24 studies. The funnel plot (Fig. 2B) showed a roughly symmetrical distribution of study estimates around the pooled effect, with no clear visual evidence of asymmetry. This visual impression was supported by Egger’s test, which did not indicate statistically significant funnel plot asymmetry (P = 0.2246). Subgroup analyses based on the level of evidence and the year of publication did not reveal any statistically significant differences (P > 0.05) (Figs. 2A and 3A).

Fig. 2.

Forest plot presenting subgroup analysis of pooled pseudoparesis incidence by level of evidence (A) and funnel plot for the assessment of publication bias (B). Note: CI, confidence interval

Fig. 3.

Forest plot presenting subgroup analysis of pooled pseudoparesis incidence by year of publication (A) and the association between female gender and pseudoparesis (B). Note: OR, odds ratio; CI, confidence interval

Risk factors for pseudoparesis

This study identified 26 factors associated with pseudoparesis in patients with MRCT. A factor was deemed eligible for quantitative meta-analysis only if at least two independent studies provided complete dichotomous data (i.e., counts of patients with/without the factor in both pseudoparesis and non-pseudoparesis groups) or comparable continuous data. If these conditions were not met, only a qualitative description was provided. Consequently, 10 risk factors underwent meta-analysis, and their pooled effect estimates are presented in Table 2. The remaining 16 factors, supported by qualitative evidence, are summarized in Table 3.

Table 2.

Summary of risk factors for pseudoparesis amenable to meta-analysis

Risk Factor	No. of studies	Effect of estimate	Heterogeneity	p value
		Summary OR/MD (95% CI)
Female	4	OR 1.74 (1.12, 2.71)	28.20%	0.0140
Older age	4	MD 4.38 (2.37, 6.38)	3.20%	< 0.0001
SSP fatty infiltration	3	MD 0.35 (0.20, 0.50)	0.00%	< 0.0001
ISP fatty infiltration	3	MD 0.32 (-0.001, 0.64)	72.20%	0.0510
TM fatty infiltration	3	MD 0.07 (-0.14, 0.28)	49.50%	0.5116
SSC fatty infiltration	3	MD 0.72 (0.49, 0.95)	32.70%	< 0.0001
CSA	4	MD 1.68 (0.67, 2.69)	35.30%	0.0011
AHD, deg	3	MD -2.71 (-3.34, -2.07)	0.00%	< 0.0001
Global tear extension, deg	3	MD 46.35 (36.45, 56.26)	73.40%	< 0.0001
Force couple ratio	2	MD 0.40 (0.28, 0.52)	0.00%	< 0.0001

OR Odds ratio, MD Mean difference, CI Confidence interval, NA Not available, CSA Critical shoulder angle, AHD Acromiohumeral distance, SSP Supraspinatus, ISP Infraspinatus, TM Teres minor, SSC Subscapularis

Table 3.

Risk factors for pseudoparesis identified by logistic regression in included studies

Author (Year)	Risk factors	Pseudoparesis n (%) or mean ± standard deviation	Control n (%) or mean ± standard deviation	P value
Besnard 2021 [4]	Shoulder strength, kg	0	1.6 ± 1.3	< 0.001
Collin 2014 [10]	Complete SSC tear	16 (94.1%)	4 (10.5%)	< 0.001
Ernstbrunner 2020 [13]	Cuff tear arthropathy	2.2 ± 1.2	1.7 ± 0.9	0.009
	Posterior acromial height, mm	22 ± 10	17 ± 7	0.013
	SSC tear	2.6 ± 0.9	1.3 ± 0.5	< 0.001
	Infraspinatus/teres minor rupture	2.8 ± 0.7	2.2 ± 0.5	< 0.001
	Anterior tear extension, deg	-9 ± 21	25 ± 12	< 0.001
	Posterior tear extension, deg	-18 ± 14	2 ± 14	< 0.001
Fonseca 2025 [15]	Shoulder shrug	6 (42.9%)	0 (0%)	< 0.001
	Intertrabecular groove palpation	0 (0%)	31 (54.4%)	< 0.001
	Speed test	0 (0%)	31 (54.4%)	< 0.001
	Subscapularis complete lesion	6 (42.9%)	9 (15.8%)	0.033
	Goutallier Ⅲ-Ⅳ(subscapularis)	7 (50%)	7 (12.3%)	0.001
Reddy 2024 [36]	Samilson-Prieto classification Grade 2–3	46 (58.2%)	17 (34%)	0.036
	SSC tear	44 (55.7%)	17 (34.0%)	0.03
Wieser 2015 [45]	Anterior center-cuff angle, deg	-8 ± 16	25 ± 18	0.001
Yao 2025 [47]	Initial trial of physical therapy	14 (39%)	47 (68%)	0.006
	Shoulder Abduction Moment Index	0.72 (0.70, 0.76)	0.75 (0.74, 0.78)	0.001

SSC Subscapularis

Age and female Four studies [11, 36, 40, 45] investigated the association between age and pseudoparesis. A pooled analysis revealed that older age was a significant risk factor for pseudoparesis (MD 4.38, 95% CI, 2.37–6.38; P < 0.0001) (Fig. 4A). Furthermore, pooled analysis of four studies [11, 36, 40, 47] indicated that female sex was significantly associated with an increased risk of pseudoparesis (OR 1.74, 95% CI, 1.12–2.71; P = 0.0140) (Fig. 3B).

Fig. 4.

Forest plot detailing the association of age (A) and fatty infiltration (B) as continuous variables with pseudoparesis in MRCT. Note: MD, mean difference; CI, confidence interval; SD, standard deviation; MRCT, massive rotator cuff tears

Fatty infiltration Meta-analysis of three studies [13, 36, 45] revealed that greater fatty infiltration in the supraspinatus (SSP) (MD 0.35, 95% CI 0.20 to 0.50; P < 0.0001) and subscapularis (SSC) (MD 0.72, 95% CI 0.49 to 0.95; P < 0.0001) muscles was a significant risk factor for pseudoparesis. In contrast, fatty infiltration of the infraspinatus (ISP) (MD 0.32, 95% CI -0.001 to 0.64; P = 0.051) and teres minor (TM) (MD 0.07, 95% CI -0.14 to 0.28; P = 0.512) did not show statistically significant associations (Fig. 4B).

CSA, AHD, global tear extension, and force couple ratio Pooled analysis of four studies [12, 34, 38, 43] showed that a larger CSA was associated with pseudoparesis (MD 1.68°, 95% CI 0.67° to 2.69°; P = 0.001) (Fig. 5A). Conversely, a reduced AHD was significantly associated with pseudoparesis in three studies [13, 36, 45] (MD -2.71 mm, 95% CI -3.34 to -2.07 mm; P < 0.0001) (Fig. 5B). Greater global tear extension on MRI, analyzed in three studies [13, 15, 45], was a strong risk factor (MD 46.35°, 95% CI 36.45° to 56.26°; P < 0.0001) (Fig. 5C). Similarly, a higher force couple ratio was associated with increased risk in two studies [13, 45] (MD 0.40, 95% CI 0.28 to 0.52; P < 0.0001) (Fig. 5D).

Fig. 5.

Forest plot detailing the association of CSA (A), AHD (B), global tear extension (C), and force couple ratio (D) as continuous variables with pseudoparesis in MRCT. Note: CSA, critical shoulder angle; AHD, acromiohumeral distance; MD, mean difference; CI, confidence interval; SD, standard deviation; MRCT, massive rotator cuff tears

In patients with MRCT, several risk factors were identified as being associated with an increased risk of pseudoparesis but were not amenable to meta-analysis due to methodological heterogeneity. These include imaging and pathological factors such as posterior acromial height [13], anterior center-cuff angle [45], cuff tear arthropathy [13], SSC tear [13, 36], infraspinatus/teres minor rupture [13], anterior and posterior tear extension [13], Samilson-Prieto classification Grade 2–3 [36], and complete lesion of SSC [15]; functional factors including a positive shoulder shrug sign [15], positive Speed test [15], shoulder strength [4], and the Shoulder Abduction Moment Index [47]; as well as other clinical factors such as intertrabecular groove palpation [15] and initial trial of physical therapy [47].

Discussion

The principal finding of this study is the pooled incidence of pseudoparesis, which was 24.6% (95% CI 20.7% to 28.8%) among 1,925 patients with MRCT, based on a meta-analysis of 24 studies. Significant risk factors for the development of pseudoparesis in patients with MRCT included older age, female sex, fatty infiltration of the SSP and SSC, greater CSA, reduced AHD, larger global tear extension, and higher force couple ratio.

This meta-analysis revealed that the overall incidence of pseudoparesis in patients with MRCT was 24.6%, which is consistent with previously reported findings. Gabig et al. [19] conducted a retrospective comparative study of 156 patients with MRCT without glenohumeral arthritis and identified pseudoparesis in 26.9% of the patients. Similarly, a multicenter study reported a 23.7% incidence in MRCT patients treated with either margin convergence or superior capsular reconstruction [35]. This high prevalence is likely linked to larger tear size. Specifically, the risk of pseudoparesis is 35 times greater when the anterior-to-posterior humeral head exposure exceeds 190° compared to smaller tears, and it becomes universal when exposure surpasses 200° [45]. Consequently, our findings corroborate a strong association between greater global tear extension and an increased risk of pseudoparesis. Recent literature further identifies inferior SSC tear extension as a major contributing factor [9].

This study identified older age and female sex as independent risk factors for pseudoparesis. Notably, Takayama et al. [40] found no significant association with age or sex, whereas Denard and Wieser et al. identified older age as a risk factor [11, 45] Older age is a known risk factor for glenohumeral osteoarthritis (GHOA), primarily due to articular cartilage degeneration [28, 30]. In MRCT, osteoarthritis may develop from glenohumeral joint instability due to an imbalance in rotator cuff muscle forces [23]. The SSC, which forms the anterior part of the transverse force couple, serves as a primary restraint against anterior translation of the humeral head. Injury to this tendon may lead to joint instability and contribute to the development of GHOA [6, 27]. Therefore, severe GHOA (Samilson-Prieto grade III) may indicate significant pathology of the SSC and serve as a predictor for pseudoparesis [36].

Our findings confirm a strong link between SSC pathology (fatty infiltration and tears) and pseudoparesis in MRCT. For instance, Rhee et al. reported complete SSC tears in 81% of pseudoparesis patients [37]. Similarly, Collin et al. [10] reported pseudoparesis in 80% of patients with a type B tear pattern (complete tears of the SSP and SSC), whereas only 2.9% of those with a type D tear pattern (complete tears of the SSP and ISP with an intact SSC) exhibited pseudoparesis. Electromyographic studies have confirmed the crucial role of the SSC in initiating forward flexion [23]. Furthermore, evidence suggests that a competent anterior rotator cuff, more so than a balanced size between the remaining anterior and posterior muscles, is essential for preserving adequate shoulder function [13]. SSC tears increase the odds of limited AFF (< 90°) by more than sixfold [36], a finding corroborated by others [17]. Furthermore, fatty infiltration of the SSC is consistently more severe in pseudoparesis patients [13, 17, 37].

Beyond soft-tissue pathology, a reduced AHD was a significant risk factor. This aligns with reports that an AHD < 6 mm increases the risk of limited forward elevation fourfold [36, 45]. A reduced AHD indicates superior humeral head migration, resulting from a loss of force counteracting the superior pull of the deltoid, leading to an imbalance in the coronal plane force couple [18, 26]. Thus, a reduced AHD also serves as a radiographic marker of advanced cuff disease and poor muscle function [21, 33]. Furthermore, this study found that an increased CSA was significantly associated with a higher risk of pseudoparesis. However, one case-control study did not identify a significant association between these factors [36]. Corroborating our results, Ernstbrunner et al. [13] suggested that acromioplasty to correct an elevated CSA in pseudoparesis patients may improve outcomes. The proposed mechanism is that reducing a large CSA decreases deltoid shear force, thereby improving its abduction moment and synergy with the residual rotator cuff.

This review identifies key risk factors for pseudoparesis, offering clinical insights. Surgeons should be alert to older MRCT patients with full-thickness SSC tears or severe SSC fatty infiltration. Assessing active versus passive range of motion is key to diagnosing pseudoparesis. These risk factors enable better patient stratification to guide management. Specifically, the combination of a full-thickness SSC tear with high-grade fatty infiltration, a markedly reduced AHD (< 6 mm), and a large CSA indicates severe force couple disruption and likely static superior humeral head migration [2, 25]. In such patients, especially older ones with concurrent arthritis (Hamada grade ≥ 3), primary anatomic repair or superior capsular reconstruction may be biomechanically unfavorable. For them, reverse total shoulder arthroplasty is often a more reliable option to restore active elevation, as it addresses the underlying biomechanical deficit [41].

Limitation

This meta-analysis has several inherent limitations. First, the majority of included studies were retrospective in design. Although retrospective studies may occasionally suggest causal relationships, they are susceptible to confounding bias; therefore, the findings of this study should be interpreted with caution. Second, for certain factors, meta-analysis could not be performed due to the unavailability of raw data from the original studies; therefore, a systematic narrative synthesis was employed for qualitative assessment. Third, significant heterogeneity was observed among studies reporting specific outcomes, which likely stems from differences in study populations, design variations, and covariate adjustments, rather than true differences in the outcomes of interest. Furthermore, since this meta-analysis used aggregate rather than individual participant data, formal confounder adjustment was not possible, and the pooled estimates represent unadjusted associations with residual confounding possible. Subgroup analyses do not substitute for individual-level adjustment and should be interpreted cautiously. The predominance of retrospective designs, lack of blinded outcome assessment, and omission of prospective sample size calculations introduce risks of detection and selection bias. To address these concerns, a random‑effects model was pre‑specified for meta‑analyses of studies that showed significant heterogeneity, as this approach yields more conservative pooled estimates in the presence of between-study heterogeneity [24]. Additionally, variations in the definition of MRCTs across different studies may influence the internal validity and generalizability of our pooled estimates. Furthermore, the methodological limitations, particularly the widespread lack of blinding in outcome assessment and potential baseline imbalances, should be taken into account when interpreting the pooled results. Finally, as the study population comprised only patients with MRCT, the findings are directly generalizable only to this group. Future research with larger samples should investigate pseudoparesis risk in other patient populations. Finally, given the predominantly retrospective and observational design of the included studies, the findings of this meta-analysis should be interpreted as identifying associations rather than establishing causation.

Conclusion

The pooled analysis revealed a pseudoparesis incidence of 24.6% in patients with MRCT. Significant risk factors associated with pseudoparesis included older age, fatty infiltration and tears of the SSC, greater CSA, reduced AHD, and larger global tear extension.

Abbreviations

AHD

Acromiohumeral distance

AFF

Active forward flexion

BMI

Body mass index

CI

Confidence interval

CSA

Critical shoulder angle

GHOA

Glenohumeral osteoarthritis

ISP

Infraspinatus

MC

Margin convergence

MD

Mean difference

MINORS

Methodological Index for Non-Randomized Studies

MIRCT

Massive irreparable rotator cuff tears

MRCT

Massive rotator cuff tears

OR

Odds ratio

PE

Passive elevation

PRISMA

Preferred Reporting Items for Systematic Reviews and Meta-Analyses

PROSPERO

International Prospective Register of Systematic Reviews

RCT

Rotator cuff tears

SAM

Shoulder Abduction Moment Index

SCR

Superior capsular reconstruction

SD

Standard deviation

SSC

Subscapularis

SSP

Supraspinatus

TM

Teres minor

VAS

Visual analog scale

Authors’ contributions

Hongwei Zhan, and Yao Li conceived and designed the study, performed data collection, and drafted the manuscript. Yue Wang and Zhitao Yang contributed to data collection and manuscript drafting. Jiang Zheng performed data collection and statistical analysis. Zandong Zhao and Qiuzhen Liang critically revised the manuscript for important intellectual content. Xin Kang participated in manuscript writing and review. Zandong Zhao and Liang Zhang contributed to study design, manuscript writing, and critical revision. All authors approved the final version for submission.

Funding

There was no funding received in the production of the manuscript.

Data availability

The data supporting this study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.