Prevalence of carpal tunnel syndrome and its associated factors among patients with musculoskeletal complaints: a single-center experience from Eastern Ethiopia

Abstract

Background

Carpal tunnel syndrome (CTS) is a well-known chronic focal mononeuropathy caused by the mechanical distortion of the nerve at the carpal tunnel. It affects approximately 5% of the population worldwide and 12.1% in Africa. However, it has severe pain that causes discomfort and disturbs daily activities, the magnitude and its risk factors are poorly understood in Ethiopia.

Objectives

This study aimed to assess the prevalence and associated factors of carpal tunnel syndrome among patients with musculoskeletal complaints in Dire Dawa, Eastern Ethiopia.

Methodology

An institution-based quantitative cross-sectional study was conducted on randomly selected 422 participants at Dilchora Referral Hospital from May–July 2023. The primary data were collected by using structured questionnaires and checklists. The history taking, anthropometric measurements, physical examination, and diagnosis of carpal tunnel syndrome were performed by the orthopedicians. The data were collected by the four BSc midwives under strict supervision. The data carefully checked for the accuracy, completeness, and validity. Next, data were put into Epi-data and then exported to SPSS for analysis. Descriptive statistics, bivariate and multivariable logistic regression analyses were carried out.

Result

The prevalence of clinically confirmed carpal tunnel syndrome was 10.8% (95% CI: 6.99% to 14.6%). A multivariable analysis revealed that physical inactivity [AOR = 3.32 (95% CI: 1.95–5.52)], diabetes mellitus [AOR = 4.23 (95% CI: 1.47–6.97)], hypertension [AOR = 2.5 (95% CI: 1.70–5.65)], hand ratio < 2.1 [(AOR = 4 (95% CI: 1.80–9.66)], and wrist ratio > 0.72 [AOR = 2.1 (95% CI: 1.11–4.72)] were statistically associated with carpal tunnel syndrome.

Conclusion

The prevalence of carpal tunnel syndrome among the musculoskeletal complaints is 10.8%. Diabetes mellitus, hypertension, physical inactivity, and a wrist ratio > 0.72 were statistically associated with carpal tunnel syndrome. Doing physical exercise, regulating blood sugar levels, and monitoring blood pressure were recommended.

Introduction

The carpal tunnel is situated at the base of the hand and is covered by the transverse carpal ligament (TCL), a robust fibrous structure. Within this confined space, the passage accommodates long tendons of flexors, their synovial sheaths, and the median nerve. Any factor increasing their volume or density of the structures can lead to compression of the median nerve, potentially causing nerve ischemia and resulting in pain and paresthesia [1–4].

Globally, up to 50% of the population may experience musculoskeletal pain monthly, and carpal tunnel syndrome (CTS) is one of the typical causes of these disorders [1]. CTS is the predominant upper extremity entrapment neuropathy, accounting one in nine of all entrapment neuropathies. It is defined as a chronic focal compressive mononeuropathy or radiculopathy resulting from mechanical compression of the nerve at the narrow, non-flexible anatomical structure. This compression induces an ischemic response to the median nerve due to repetitive motion and high force. CTS frequently leads to prolonged impairment, often necessitating surgical intervention [5].

Common symptoms of CTS include hand pain, tingling sensations, numbness in the thumb, index, and middle fingers, weakness, and a decrease in hand function. [6, 7]. The symptoms often become more pronounced at night, and activities during the day that require bending the wrist can lead to a feeling of clumsiness. Patients commonly mention the"flick sign,"where shaking or flicking their wrists relieves discomfort [8, 9].

The causes of CTS have provoked intense debate for decades. According to existing literatures, some anatomical measurements of the hand and wrist may have relationships with CTS. The wrist ratio (a measurement of wrist width and depth) above 0.70 is considered a predisposing factor for CTS. The Wrist Ratio is used in the diagnosis and assessment of CTS and is calculated dividing anteroposterior dimension of the wrist by mediolateral dimension [1]. The hand ratio that compares the index finger length (2D) to the ring finger (4D) may have a significant difference between a biological sex. The hand-to-height ratio explains the relationship between an individual's height and their hand length may have contribute to CTS [2].

Moreover, several risk factors have been believed to be firmly linked to its onset and exacerbation. Environmental factors, repetitive muscle activity, and conditions restricting the carpal tunnel are significant contributors to the development of CTS. In addition, specific disorders such as misaligned Colles'fracture, edema from infection or trauma, posttraumatic arthritis, and various tumors have been identified as frequent causes of CTS. Moreover, personal risk factors like physical inactivity and systemic diseases, including obesity, diabetes, and thyroid dysfunction, have been confidently associated with the syndrome [10–19].

In Ethiopia, there is a lack of comprehensive studies focusing on the prevalence, risk factors, and outcomes of CTS. Even though CTS disturbs the health condition of a significant population, it remains neglected, with little done on awareness among healthcare providers and the general public regarding CTS. This can lead to underdiagnosis or misdiagnosis, as symptoms may be attributed to other conditions. Access to specialized care for musculoskeletal disorders may be limited in rural areas, leading to delayed diagnosis and treatment. Many patients might not seek medical attention until symptoms become severe. There is insufficient research on occupational risk factors associated with CTS in the country. Furthermore, there might be limited access to effective treatment options, including surgical interventions, due to resource constraints in the healthcare system [6, 7, 19–22]. Therefore, this study aimed to assesses magnitude of CTS and its associated factors of carpal tunnel syndrome among patients with musculoskeletal complaints in Dire Dawa, Eastern Ethiopia.

Research questions:

• What is the magnitude of the carpal tunnel syndrome in the community?

• What are the factors associated with tunnel syndrome in the community?

Hypothesis

The prevalence of Carpal Tunnel Syndrome is higher in women, in higher wrist ratio, older people, obese people, and individuals with chronic diseases like diabetes mellitus, hypertension, etc.

Methods and materials

Study period, design, and population

The institution-based quantitative cross-sectional study design was conducted at Dilchora Referral Hospitals from May–July 2023. The study was conducted on 422 randomly selected musculoskeletal complaints visiting the orthopedic OPD. All women who have physical deformity on the limbs or other parts that affect anthropometric measurements were excluded from the study.

All patients with congenital musculoskeletal abnormalities (involving the shoulder, elbow, and hand), recent fractures or injuries, and surgeries to these areas, as well as those with cognitive impairment that interferes with communication, were not eligible for the study.

Sample size determination and sampling procedures

Sample size determination

The sample size was calculated using the single population proportions formula. We used 95% confidence interval. We took the proportion of occurrence of CTS (p₁) = 50%; the proportion of non-occurrence of CTS (p₂) = 50% to maximize sample size. We used a marginal error of 5%. The required sample size was calculated as follows:

$$\mathbf{n}\mathbf{=}{\mathbf{z}}^{\mathbf{2}}\mathbf{p}\mathbf{(}\mathbf{1}\mathbf{-}\mathbf{p}\mathbf{)}\mathbf{/}{\mathbf{d}}^{\mathbf{2}}\mathbf{,}$$

Where, n= sample size, p= prevalence, d= margin of error

$$\mathrm{n}={(1.96)}^2\mathrm{x}(0.5)(0.5)/(0.05)_{}^2=384$$

We considered a 10% nonresponse rate, and a total sample size was 422 musculoskeletal complaints.

Sampling procedures

To include 422 participants during the study, we used systematic random sampling, based on the case flow of the musculoskeletal complaint to the orthopedic OPD. Averagely, about 22 musculoskeletal complaints visit the OPD every day; approximately 1,932 were diagnosed with musculoskeletal system diseases (based on HMIS disease classification) in the orthopedic OPD during the three-month study period. The calculated ‘K’ was 5, and the participants were included in every 5th case. The first or beginning sample was selected by simple random sampling.

Data collection tools, procedure, and quality control

The relevant data were collected by using questionnaires and checklists that were developed by principal investigators reviewing different relevant related literature on the CTS. The data collection tool consists of three parts. The first part assesses sociodemographic characteristics of the respondents, the second part assesses the history of the respondents, and the third part is the checklist that assesses physical examination, anthropometric measurement, and laboratory investigations. A pre-test was carried out in 5% of the sample size at Hiwot-Fana Specialized University Hospital to ensure consistency and validity before the actual data collection, and adequate modifications were performed based on the pre-test.

Orthopedicians and BSc nurses were given a two-day training concerning the objectives of the study, concepts, approachability, procedures of anthropometric measurements, and ethical issues. Orthopedicians performed history taking, physical examinations, diagnoses, and anthropometric measurements. After the assessments were done by the orthopedicians, the data were carefully filled into questionnaires and checklists by the BSc nurses. The validity, accuracy, consistency, and completeness of the filled data were thoroughly checked on a daily basis. The principal investigator provided a day-to-day on-site supervision during the whole period of data collection.

The clinical diagnosis of CTS was conducted using a standard diagnostic questionnaire recommended in a previous study. A score of 5 or more on the test is recommended as a diagnostic tool to replace nerve conduction studies, which are considered the gold standard test [23].

In addition to the standard diagnostic questionnaire, two crucial clinical tests were conducted to enhance the case detection rate. The first test, Phalen’s wrist flexion test, involves passively flexing the wrist for 60 s to assess for pain and paresthesia in the median nerve distribution, indicating a positive result. This test boasts a sensitivity of 68% and a specificity of 73%. The second test, the carpal tunnel compression test, entails applying firm pressure directly over the carpal tunnel, typically with the thumbs, for up to 30 s to elicit symptoms and signal a positive result. This test exhibits a sensitivity of up to 89% and a specificity of 96% [18, 24, 25].

Definition of anthropometric parameters measurements

• The wrist ratio (WR):we calculated by dividing the anteroposterior length wrist width by the mediolateral length of wrist [26, 27].

• Hand ratio (HR): We calculated by dividing the length of the index finger by the length of the ring finger of the same hand. The lengths are measured on the palm side of the hand, from the crease at the base of the finger to the tip [27–29].

• The hand-to-height ratio: we measured individual's hand and divided to height [30, 31].

Data analysis and interpretation

The data underwent a comprehensive review for completeness, was coded, and entered into Epi-Data version 3.1 statistical software. Subsequently, the data was exported to SPSS version 25 for analysis. Descriptive statistics for various variables were presented using tables, bar graphs, and pie charts to display frequency and percentage. Mean and standard deviation were calculated for numerical variables. The model's goodness of fit was evaluated using Hosmer–Lemeshow’s test. Bivariable logistic regression analyses were conducted to identify independent variables associated with CTS. Independent variables with a p-value of < 0.25 and those identified in previous studies to be associated with CTS were included in the multivariable logistic regression to control for confounding factors. Finally, independent variables significantly associated with CTS at p-values < 0.05 were identified using adjusted odds ratios (AOR) with a 95% confidence interval.

Result

Socio-demographic characteristics

A total of 422 were participated with 100% response rate. Among them, 253 (60%) were women. Nearly half of the occupation of the participants was 186 (44.2%) were housewives. The average age of the participants was 52 ± 4.4 years. Most respondents, 333 (79.1%), resided in rural areas. (Table 1).

Table 1.

Sociodemographic characteristics participants among musculoskeletal complaints at Dilchora referral hospitals, eastern Ethiopia, 2023 (N = 422)

Variable	Frequency	Percentage (%)
Age in years
< 45 >	160	38
45	262	62
Sex
Male	169	40.0
Female	253	60.0
Residence
Rural	333	79.1
Urban	89	20.9
Occupation
Factory worker	13	3.1
Office worker	36	8.5
Housewife	186	44.2
Unemployed	23	5.4
Merchant	34	8.1
Private business	73	17.3
Agricultural worker	18	4.2
Teacher	39	9.2
Physical Activity
Had exercise	258	61.2
Never had exercise	163	38.8
Habit of smoking
Smoker	89	21
Non-smoker	333	79
Hand dominance
Right-handed	375	88.8
Left-handed	47	11.2
BMI
Abnormal	188	44.6
Normal	234	55.4

Medical characteristics of respondents

The medical condition of the study participants is shown in the following figure. (Fig. 1).

Fig. 1.

Medical condition of the study participants at Dilchora Referral Hospitals, eastern Ethiopia, 2023 (N = 422). Where; HTN: hypertension, DM: diabetes mellitus

Most participants (45.8%) reported neck pain. Back pain, shoulder pain and stiffness, and knee pain were reported by 13.1%, 9.6%, and 10% of participants, respectively.

Total score for participant response to clinical diagnostic criteria

Out of 422 participants, 43.8% of them scored zero, indicating that CTS did not cause wrist and hand symptoms. Another 43.8% scored below 3, which is considered unlikely to indicate CTS. Only 1.6% of participants had a score between 3 and 4, suggesting the possibility of CTS as the cause of their symptoms. The remaining 10.8% of participants had a score of 5 or greater, which is strongly suggestive of the presence of CTS. So that the prevalence of CTS was 10.8%. (Table 2).

Table 2.

Total score for participant response to clinical diagnostic criteria at Dilchora referral

Score	Frequency	Percentage(%)	Interpretation
A score of “0”	185	43.8	Wrist and hand symptom is not caused by CTS
A score of “<3”	185	43.8	Unlikely to be indicative of CTS
A score of “3–4”	7	1.6	Suggests CTS is possible cause of symptoms
A score of “>= 5”	46	10.8	Strongly suggestive of CTS (Define the presence of CTS)

Hospitals, eastern Ethiopia, 2023(N=422)

For the Phalen's wrist flexion test, 20.8% had a positive result, of whom 33.3% had CTS. For the Carpal Tunnel Compression test, 21.5% had a positive result, of whom 33.9% had CTS. (Table 3).

Table 3.

Phalen's wrist flexion test among musculoskeletal complaints at Dilchora Referral Hospitals, eastern Ethiopia, 2023 (N = 422)

Type of test	Test Result	Frequency (%)	CTS Status
			Yes	No
Phalen’s wrist flexion	+	88(20.8)	29(33.3%)	59(66.7%)
	-	334(79.2)	16(4.9%)	318(95.1%)
Carpal Tunnel Compression	+	91(21.5)	31(33.9%)	60(66.1%)
	-	331(78.5)	15(4.4%)	316(95.6%)

Measured anthropometric parameters of hand and wrist dimension

The figure shows anthropometric measurements of hand length (17.87 ± 1.51 cm), palm width (7.49 ± 0.88 cm), wrist width (6.32 ± 0.76 cm), wrist depth (3.82 ± 0.75 cm), wrist ratio (0.6 ± 0.11), and hand ratio (2.4 ± 0.22). (Fig. 2).

Fig. 2.

Mean values and standard deviation of anthropometric measurements among musculoskeletal complaints at Dilchora Referral Hospitals, eastern Ethiopia, 2023. Where; HR: hand-to-height ratio, WR: wrist-to-hand ratio

The figure shows the distribution of hand-to-height ratio (HR) and wrist-to-hand ratio (WR) in the population. For HR ≤ 2.1, the percentage is 56.5% with a frequency of 147. For HR > 2.1, the percentage is 43.5% with a frequency of 113. For WR ≥ 0.72, the percentage is 21.5% with a frequency of 56, while for WR < 0.72, the percentage is 78.5% with a frequency of 204. These anthropometric measures could be relevant for various applications.(Fig. 3).

Fig. 3.

Distribution of HR and WR among musculoskeletal complaints at Dilchora Referral Hospitals, eastern Ethiopia, 2023 (N = 422)

Factors associated with carpal tunnel syndrome

On multivariable logistic regression, undoing physical exercises, having diabetes mellitus, hypertension, and specific hand-wrist anthropometric measurements (HR ≤ 2.1, WR ≥ 0.72) had a significant association with CTS. Participants who did not do physical exercise were 3.32 times [AOR = 3.32 (1.95–5.52)] more likely to acquire CTS than those who did physical exercise. Participants with diabetes mellitus were 4.23 times [AOR = 4.23 (1.47–7.97)] more likely to develop CTD when compared to non-diabetic participants. Hypertensive participants were 2.5 times [AOR = 2.5 (1.70–5.65)] to develop CTD when compared to non-hypertensive participants. Participants with hand ratio ≤ 2.1 were 4 times [AOR = 4 (1.80–9.66)] to acquire CTS when compared to their counterparts. Participants with wrist ratio < 0.72 had 2.1 times [AOR = 2.1 (1.11–4.72)] more likelihood to develop CTS when compared to their counterparts. (Table 4).

Table 4.

Associated factors of CTS among musculoskeletal complaints at Dilchora Referral Hospitals, eastern Ethiopia, 2023(N = 422)

Variables		CTS		COR (95% CI)	AOR (95% CI)
		No = (376)	Yes (= 46)
Sex	Female	217(85.9%)	36(14.1%)	2.68(1.04, 6.86)	3.26(0.85, 10.08)
	Male	141(94.2%)	10(5.8%)	1	1
Physical Exercise	Never had exercise	136(83.2%)	28(16.8%)	2.72(1.21, 6.08)	3.32(1.95, 5.52)*
	Had exercise	240(93.1%)	18(6.9%)	1	1
Diabetes Mellitus	Yes	102(80.5%)	25(19.5%)	3.35(1.50,7.47)	4.23(1.47, 6.97)*
	No	274(93%)	21(7%)	1
Hypertension	Yes	31(53.45%)	27(46.55%)	3.75(1.53, 5.18)	2.5 (1.70, 5.65)*
	No	333(94.6%)	19(5.3%)	1
BMI	> = 25 kg/m2	155(83.3%)	31(16.7%)	3.04(1.32,7.01)	1.84(0.67, 5.05)
	< = 24.9 kg/m2	221(93.8%)	15(6.2%)	1	1
HR	< = 2.1	199(83%)	39(17%)	5.514(2.20, 8.57)	4 (1.80, 9.66)*
	> 2.1	177(96%)	7(4%)	1	1
WR	> = 0.72(Ref)	68(75%)	23(25%)	3.52(2.07, 4.19)	2.1 (1.11, 4.72)*
	< 0.72	308(93.1%)	23(6.9%)

BMI Body mass index, HR Hand, WR Wrist ratio

^*Significant association at AOR P-value < 0.05 

Discussion

This study primarily assessed the prevalence CTS and its associated factors among patients with musculoskeletal complaints at Dilchora Referral Hospitals, Eastern Ethiopia. Accordingly, Factors such as lack of physical exercise, the presence of diabetes mellitus, hypertension, a hand ratio less than 2.1, and a wrist ratio greater than 0.72 were significantly associated with CTS.

This study revealed that the prevalence of the medically diagnosed CTS among musculoskeletal complaints was 10.8%. This finding is consistent with studies carried out in China, Iran, and Saudi Arabia, with prevalence rates of 9.6%, 8.56%, and 6.7%, respectively [24, 32, 33].

However, the prevalence of CTS in the current study is markedly lower when compared to similar investigations conducted among diabetic patients in the United Kingdom (20%), India (19.8%), Bangladesh (26%), and Ethiopia (29.2%) [9, 28, 34, 37].

On the other hand, the occurrence of CTS in this study is higher than in other study reports from Arbaminch, Ethiopia, (3.1%), Addis Ababa, Ethiopia (1%) and Jordan (5.5%). This difference in prevalence might arise from the case definitions based on symptoms alone in the previous studies, leading to relatively lower estimates [26, 35, 36].

Based on the recent study's findings, undoing physical exercise increases the chance of developing CTS. This finding is in line with the study findings reported from Saudi Arabia, which indicated that the likelihood of experiencing CTS was less among the participants who engaged in regular physical exercise [27]. This might be because exercise can strengthen muscles and enhance the elasticity of tendons (and ligaments). In addition, exercise promotes better circulation, which can help nourish tissues and reduce inflammation in the hands and wrists [37]. Furthermore, regular physical exercise can significantly reduce the risk of acquiring CTS by improving flexibility, reducing stiffness, and promoting overall wrist health. Therefore, it is advisable to consult with a healthcare professional or physical therapist for personalized guidance and exercise recommendations.

In the present study, having diabetes had a higher odd of developing CTS. This finding is consistent with a nationwide population-based cohort study conducted in Taiwan, which revealed that patients with diabetes mellitus had the highest risk for CTS [38]. Prolonged hyperglycemia can cause increased serum glucose levels, leading to inflammation and adhesion of tendons in the carpal tunnel. This can also result in demyelination of the median nerve, axonal degeneration, macrophage activation, and release of inflammatory compounds [12, 39]. It is recommended that individuals with diabetes should be aware of these risks and take proactive steps to manage their blood sugar levels to promote wrist health.

In our study, hypertension increases the likelihood of developing CTS. This finding is supported by the study finding from Boston [40]. This might be due to long-term high blood pressure causing a breakdown in the blood-nerve barrier, leading to increased permeability causing fluid retention, protein buildup, inflammatory cell accumulation, and the development of edema [7]. It is recommended that individuals with hypertension be mindful of these risks and consider regular monitoring and management of their blood pressure.

This study revealed that participants with a hand ratio of less than 2.1 were four times more likely to develop CTS when compared to their counterparts. This finding is supported by an experimental study conducted in Austria [19]. Shorter and broader hands (hand ratio < 2.1) may require extra force during hand movement, leading to increased pressure in the intracarpal area and the development of CTS [32].

This study's findings highlighted that a wrist ratio greater than 0.72 increases the odds of developing CTS. This finding is in line with a meta-analysis of 16 studies [41], other studies from Turkey [42], and Greece [22]. The correlation lies in the assumption that a square wrist shape necessitates greater volar extension or flexion for a given motion, resulting in compression of the median nerve and the development of CTS [17].

Strength and limitation

As a strength, this study tried to reduce bias by randomizing the selection of study participants. We also reduced confounder bias during analysis. As a limitation, this study was hospital-based, and it lacks generalizability to the community at large. In addition, this study is limited to show cause-and-effect relationship independent variables and CTS. Moreover, this study used clinical diagnosis criteria of the CTS which did not include electrophysiological confirmatory diagnosis methods of the CTS due to unavailability of the test in the study area.

Conclusion and recommendation

The prevalence of carpal tunnel syndrome among patients with musculoskeletal complaints is 10.8%.

Undoing physical exercise, diabetes mellitus, hypertension, a hand ratio less than 2.1, and a wrist ratio greater than 0.72 were significantly associated with CTS. Doing physical exercise, regulating blood sugar levels, monitoring blood pressure were recommended.

Abbreviations

CTS

Carpal Tunnel Syndrome

HR

Hand Raio

WR

Wrist Ratio

BMI

Body Mass Index

AOR

Adjusted Odds Ratio

OPD

Outpatient Department

HMIS

Health Management Information System

TCL

Transverse Carpal Ligament

Authors’ contributions

TY, AB, HA, and YA participated in the conceptualization, formal analysis, investigation, methodology, supervision, visualization, writing-original draft, writing-review and editing, and approving the final draft. All authors read and approved the manuscript.

Funding

The authors received no funding from any organization or funding agencies.

Data availability

The data sets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

The study was conducted in accordance with the Declaration of Helsinki’s standard of human research ethics. The was initiated after receiving approval from the Institution Review Board of the University of Gondar. The University of Gondar College of Medicine and Health Sciences sent an official letter to Dilchora referral hospital, requesting permission from the facility directors. The study's purpose and objectives were communicated to each participant, and written consent was obtained from all of them. Participants were assured that their involvement was voluntary, no risks/harms, and that they could withdraw from the study at any point if they felt uncomfortable. To maintain confidentiality, the data collection process was designed to be anonymous.

Consent for publication

‘We, give our full consent for the publication of the manuscript titled: "Prevalence of Carpal Tunnel Syndrome and Its Associated Factors among Patients with Musculoskeletal Complaints: A Single-Center Experience from Eastern Ethiopia. We confirm that the manuscript does not infringe upon any copyright, privacy, or other rights of third parties. In cases where individuals are identifiable, written informed consent has been obtained and is available upon request. All authors have reviewed the final version of the manuscript and approve its submission and potential publication.

Competing interests

The authors declare no competing interests.