Medical and non-medical correlates of carpal tunnel syndrome in a Taiwan cohort of one million

Carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is the most common nerve entrapment disorder worldwide. The epidemiology and risk factors, including family burden, for developing CTS are multi-factorial. Despite much research, its intricate pathophysiological mechanism(s) are not fully understood. An underlying subclinical neuropathy may indicate an increased susceptibility to developing CTS. Although surgery is often performed for CTS, clear international guidelines to indicate when to perform non-surgical or surgical treatment, based on stage and severity of CTS, remain to be elucidated. Neurophysiological examination, using electrophysiology or ultrasonography, performed in certain circumstances, should correlate with the history and findings in clinical examination of the person with CTS. History and clinical examination are particularly relevant globally owing to lack of other equipment. Various instruments are used to assess CTS and treatment outcomes as well as the effect of the disorder on quality of life. The surgical treatment options of CTS - open or endoscopic - offer an effective solution to mitigate functional impairments and pain. However, there are risks of post-operative persistent or recurrent symptoms, requiring meticulous diagnostic re-evaluation before any additional surgery. Health-care professionals should have increased awareness about CTS and all its implications. Future considerations of CTS include use of linked national registries to understand risk factors, explore possible screening methods, and evaluate diagnosis and treatment with a broader perspective beyond surgery, including psychological well-being.

Association of carpal tunnel syndrome risk factors with treatment modality selection focusing on corticosteroid injection and surgery: A nationwide population-based study

Several studies have revealed the risk factors for carpal tunnel syndrome (CTS). However, no studies have evaluated the influence of these risk factors on the selection of treatment modalities for CTS. This study aimed to determine the influence of CTS risk factors on the selection of CTS treatment modalities with a focus on corticosteroid injection (CI) and surgery. We conducted a retrospective cohort study of patients aged ≥20 years with newly diagnosed CTS in the Korean health insurance review and assessment service between 2010 and 2019. We evaluated the demographic information, the existence of CTS risk factors, and the applied treatment modalities for CTS, including CI and operation. The CTS risk factors include age, sex, diabetes mellitus, osteoarthritis of the hand or wrist, rheumatoid arthritis, hypothyroidism, gout, chronic kidney disease (CKD) on dialysis, antiestrogen or aromatase inhibitor medication, and a history of distal radius fracture (DRF). Multivariable logistic regression analyses were conducted. Age over 80 years was the most significantly associated factor for the selection of CI in CTS (odd ratio [OR], 2.149; 95% confidence interval [CI], 2.092 to 2.209; P < .001). Among underlying diseases or medications, CKD on dialysis (OR, 4.001; 95% CI, 3.819-4.193; P < .001) was the most significant associated factor for the selection of operation for CTS, followed by a history of DRF (OR, 1.803; 95% CI, 1.749-1.860; P < .001). Old age was the most significantly related factor for selecting CI. Among underlying diseases or medications, CKD on dialysis and the history of DRF were the most significantly related factors for selecting operative treatment. For these patients, clinicians should proactively consider an operation to reduce the long-term discomfort and economic burdens.

Investigating the association between diabetes and carpal tunnel syndrome: A systematic review and meta-analysis approach

INTRODUCTION

In recent years, several studies have reported on the relationship between diabetes and carpal tunnel syndrome (CTS). However, due to their contradictory results, a systematic review and meta-analysis were conducted to investigate this subject.

METHODS

This study is a systematic review and meta-analysis of studies published in ISI Web of Science, Scopus, PubMed, Cochrane, Google Scholar, and Embase databases. Heterogeneity in the studies included in the meta-analysis was evaluated using statistical tests such as the Chi-square test, I2, and forest plots. Publication bias was assessed using Begg's and Egger's tests.

RESULTS

This investigation analyzed data from 42 studies conducted between 1985 and 2022, with a total of 3,377,816 participants. The meta-analysis demonstrated that the odds ratio (OR) of CTS in participants with a history of diabetes compared to those without was 1.90 (95% CI: 1.64-2.21; P-value < 0.001). Given that publication bias was observed in this study (Begg's test P-value = 0.01), the modified OR was calculated with consideration of missed studies, which was 1.68 (95% CI: 1.45-1.94; P-value < 0.001).

CONCLUSION

The results of this study suggest that diabetic patients have 90% higher odds of developing CTS compared to non-diabetic individuals, which is statistically significant.

Risk factors for carpal tunnel syndrome in patients attending the primary care center of a tertiary hospital in Riyadh, Saudi Arabia: A case-control study

BACKGROUND

Carpal tunnel syndrome (CTS), the most common entrapment neuropathy in the upper extremity, is known to be a multi-factorial disease that raises medical and nonmedical risk factors. The aim of the current study was to determine the risk factors of CTS in patients attending the primary care center at a tertiary hospital.

MATERIALS AND METHODS

A case-control study was conducted by reviewing all medical records of patients above the age of 18 years old diagnosed with CTS from 2015 to 2021. The selected cases were evaluated by physical examination and confirmed by a nerve conduction study. Cases and controls were matched by age, gender, and nationality, with a case-to-control ratio of 1:2. Odds ratios were calculated for association between carpel tunnel syndrome and various factors and Chi-sqauare test determined statistical significance. Multiple logistic regression was performed to adjust for confounding.

RESULTS

The study recruited 144 cases with a mean age of 53.38 ± 12.20 years and 288 controls with a mean age of 53.80 ± 12.27 years. The majority of subjects were female (84.7%) and of Saudi nationality (68.3%). There was a significant difference in body mass index, employment status, number of years of employment, occupation, mean systolic blood pressure, mean low-density lipoprotein cholesterol level, and mean blood urea level between cases and controls (P < 0.05). Laboratory tests that were found to be significantly associated with CTS in univariate analysis were thyroid-stimulating hormone (crude odds ratio [COR] = 0.828) and urea level (COR = 0.802). In fully adjusted analyses, obesity (adjusted odds ratio [AOR] =3.080), chronic kidney disease (AOR = 3.629), and the use of corticosteroid (AOR = 0.470) were also significantly associated with CTS.

CONCLUSION

Similar to the findings of other studies, this study identified several potential risk factors for CTS. More large-scale longitudinal studies are required to establish a precise causal association.

Association of Economic Well-Being With Comorbid Conditions in Patients Undergoing Carpal Tunnel Release

PURPOSE

Medical comorbidities have been associated with the development of carpal tunnel syndrome (CTS), severity at the time of presentation, and outcomes of carpal tunnel release (CTR). Socioeconomic factors have also been associated with worse function in patients with CTS at presentation and after surgery. However, the effects of economic well-being on the prevalence of medical comorbidities in patients with CTS have not been well-described. The objective of this study was to determine whether economic well-being is associated with medical comorbidities in a cohort of patients undergoing CTR.

METHODS

Patients (n = 1,297) who underwent CTR at a single tertiary care referral center over a 5-year period from July 2008 to June 2013 were retrospectively identified. The exclusion criteria were acute trauma or infection, revision surgery, incomplete medical records, and neoplasm excision. Additionally, patients were excluded if they lacked documented confirmatory or normal electrodiagnostic study findings prior to CTR. Finally, this study comprised a cohort of 892 patients with electrodiagnostic study-confirmed CTS who underwent CTR. The economic well-being of patients was assessed using the Distressed Communities Index. The comorbidities of diabetes mellitus, chronic kidney disease, hypertension, hypothyroidism, cervical radiculopathy, tobacco use, and body mass index were assessed. Bivariate comparisons were used to determine the associations between the tiers of economic well-being and comorbidities.

RESULTS

Lower economic well-being was associated with body mass index, diabetes mellitus, chronic kidney disease, and tobacco use in these patients. Although hypertension, hypothyroidism, and cervical radiculopathy were not associated with economic well-being, their comparisons were underpowered.

CONCLUSIONS

Patients experiencing economic distress have a higher comorbidity burden, and as such, may be at an increased risk of complications or poorer outcomes. The association between economic well-being and comorbidities in this population suggests the need for a multidisciplinary care model that addresses both compressive neuropathy and the associated economic factors.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Independent risk factors of carpal tunnel syndrome: Assessment of body mass index, hand, wrist and finger anthropometric measurements

BACKGROUND: The most prevalent neuropathy in the upper extremity is carpal tunnel syndrome (CTS). A variety of related risk factors such as biomechanical exposures, body mass index (BMI), sex and hand shape are reported to be related to CTS. OBJECTIVE: We aimed to identify the role of BMI, hand, wrist and finger anthropometric dimensions in the development of CTS, and to compare these measured variables between control and CTS participants. METHODS: A cross-sectional, case control study (n = 240, CTS = 120, controls = 120) with participants recruited from a convenience sample diagnosed with CTS and referred for anthropometric measurements. The control participants were matched by age and sex. The body height, weight, hand width, hand length, wrist depth, wrist width, wrist circumference, and finger length were measured. Hand, wrist and finger indices, hand to height ratio, and BMI were calculated. Mean values of all dimensions were compared between cases and controls, and the role of independent risk factors were determined by logistic regression analysis. RESULTS: The mean BMI, age, weight, sex and height were not significant between the two groups. Among the measured dimensions and calculated indices the significantly different variables between two groups were the wrist width, wrist depth, wrist circumference, hand index, hand to height index, and wrist index. Regression analysis showed that the wrist index (β=-1.7, p = 0.0001), wrist depth (β=0.25, p = 0.0001) and wrist width (β=0.21, p = 0.0001) were the strongest factors in CTS development in the sample. CONCLUSION: Wrist parameters have a strong role in predicting the development of CTS, while BMI was not confirmed as an independent risk factor.

Socioeconomic Differences between Sexes in Surgically Treated Carpal Tunnel Syndrome and Ulnar Nerve Entrapment

We aimed to investigate socioeconomic differences between sexes and the influence on outcome following surgery for carpal tunnel syndrome (CTS) or ulnar nerve entrapment (UNE) at the elbow. Patients with CTS (n = 9000) or UNE (n = 1266) registered in the Swedish National Register for Hand Surgery (HAKIR) 2010-2016 were included and evaluated using QuickDASH 12 months postoperatively. Statistics Sweden (SCB) provided socioeconomic data. In women with CTS, being born outside Sweden, having received social assistance, and more sick leave days predicted worse outcomes. Higher earnings and the highest level of education predicted better outcomes. In men with CTS, more sick leave days and having received social assistance predicted worse outcomes. Higher earnings predicted better outcomes. For women with UNE, higher earnings predicted better outcomes. In men with UNE, only sick leave days predicted worse outcomes. In long-term follow up, socioeconomic status affects outcomes differently in women and men with CTS or UNE.

Socioeconomic Status Affects Pre- and Postoperative Two-point Discrimination in Patients with Carpal Tunnel Syndrome

Carpal tunnel release is a life-changing procedure within hand surgery. Multiple factors may have an impact on the outcome following surgery.

Preoperative Electrophysiology in Patients With Ulnar Nerve Entrapment at the Elbow-Prediction of Surgical Outcome and Influence of Age, Sex and Diabetes

The impact of preoperative electrophysiology on outcome of surgical treatment in ulnar nerve entrapment at the elbow (UNE) is not clarified. Our aim was to evaluate influence of preoperative electrophysiologic grading on outcome and analyse how age, sex, and in particular diabetes affect such grading. Electrophysiologic protocols for 406 UNE cases, surgically treated at two hand surgery units reporting to the Swedish National Quality Register for Hand Surgery (HAKIR; 2010-2016), were retrospectively assessed, and graded as normal, reduced conduction velocity, conduction block or axonal degeneration. Outcome of surgery after primary and revision surgery was evaluated using QuickDASH and a doctor reported outcome measure (DROM) grading. No differences in QuickDASH or DROM were found between the four groups with different electrophysiologic grading preoperatively, or at three and 12 months or at follow up, respectively. When dichotomizing the electrophysiologic grading into normal and pathologic electrophysiology, cases with normal electrophysiology had worse QuickDASH than cases with pathologic electrophysiology preoperatively (p=0.046). Presence of a conduction block or axonal degeneration indicated a worse outcome by DROM grading (p=0.011). Primary surgeries had electrophysiologic more pronounced nerve pathology compared to revision surgeries (p=0.017). Cases of older age, men, and those with diabetes had more severe electrophysiologic nerve affection (p&lt;0.0001). In the linear regression analysis, increasing age (unstandardized B=0.03, 95% CI 0.02-0.04; p&lt;0.0001) and presence of diabetes (unstandardized B=0.60, 95% CI 0.25-0.95; p=0.001) were associated with a higher risk of a worse electrophysiologic classification. Female sex was associated with a better electrophysiologic grading (unstandardized B=-0.51, 95% CI -0.75- -0.27; p&lt;0.0001). We conclude that older age, male sex, and concomitant diabetes are associated with more severe preoperative electrophysiologic nerve affection. Preoperative electrophysiologic grade of ulnar nerve affection may influence surgical outcome.

Association between hormone replacement therapy and carpal tunnel syndrome: a nationwide population-based study

OBJECTIVE

Carpal tunnel syndrome (CTS) is the most common compressive focal mononeuropathy, and the increased incidence in postmenopausal and pregnant women suggests its association with oestrogen. The objective of this study is to evaluate the relationship between hormone replacement therapy (HRT) and the occurrence of CTS.

DESIGN

Population-based case-control study.

SETTING

Nationwide health insurance programme operated by the government with a near 100% coverage rate.

PARTICIPANTS

We identified women ≥45 years old in the Health Insurance Research Database of Taiwan, which contains data on a representative sample of one million enrollees. After exclusion of those who were diagnosed with CTS before the prescription of HRT, a total of 118 309 participants were included and followed up for 15 years starting from 1 January 1996. Both HRT and occurrence of CTS were identified using the insurance claims.

MAIN OUTCOME MEASURES

We identified incident patients of CTS and evaluated the association between HRT and CTS by calculating the OR.

RESULTS

Of the 4535 participants who developed CTS during the study period, 2334 (51.5%) were HRT recipients. In participants without CTS, the proportion of HRT recipients was 28.1%, yielding an OR of 2.72 with a 95% CI of 2.56 to 2.88. After adjustment for age, diabetes, rheumatoid arthritis, hypothyroidism, gout and obesity, the OR of CTS associated with HRT was 2.04 (95% CI 1.91 to 2.17). While HRT, diabetes, rheumatoid arthritis and gout had similar effects on CTS across all age groups, hypothyroidism and obesity had different effects on different groups.

CONCLUSION

This study observed a positive association between HRT and CTS, independent of age, diabetes, rheumatoid arthritis, hypothyroidism, gout and obesity. While the ORs of CTS associated with HRT were similar across age groups, those associated with hypothyroidism and obesity were not, indicating effect modifications by age.

Risk Factors of Carpal Tunnel Syndrome in Taiwan: A Population-Based Cohort Study

BACKGROUND

Carpal tunnel syndrome (CTS), 1 of the most common peripheral neuropathies of the upper extremity, has been studied for decades regarding its epidemiology and associated medical conditions. We conducted a large-scale, age- and gender-matched study from an Asian population database to investigate the relationship between the incidence and the demographic characteristics.

METHODS

A retrospective cohort study using data of National Health Insurance Research Database was conducted. One million enrollees in Taiwan was used to identify 9442 patients with CTS and 37,768 randomly selected controls, in a control-case ratio of 4:1. Diagnoses of CTS were ascertained from January 1, 2003, to December 31, 2012. Sociodemographic and medical characteristics were evaluated to assess the correlation with CTS.

RESULTS

Annual incidence of CTS was approximately 0.4% during the 10-year-period in Taiwan, with higher incidence rate in female sex and middle age of group (50-59 years). Among the medical conditions, previous wrist injuries, obesity, gout, and rheumatoid arthritis were associated with CTS most significantly.

CONCLUSIONS

Carpal tunnel syndrome has presented a relatively constant incidence in Taiwan. Female gender with middle age seemed to have the highest incident rate during a 10-year period from 2003 to 2012. Among the risk factors of CTS, previous wrist injuries, obesity, gout, and rheumatoid arthritis were demonstrated to be the most significantly correlated comorbidities.

Replication of epidemiological associations of carpal tunnel syndrome in a UK population-based cohort of over 400,000 people

Introduction

Several phenotypic factors are associated in the literature with an increased risk of carpal tunnel syndrome (CTS). Along with female sex and older age, certain systemic diseases show an association with CTS, with varying degrees of evidence.

Methods

This study was performed using the UK Biobank resource – a cohort study of over 500,000 participants who have allowed linkage of phenotypic data with their medical records. We calculated the prevalence of CTS and a sex-specific prevalence ratio and compared the body mass index (BMI) between cases and controls. We performed a series of nested case-control studies to compute odds ratios for the association between CTS and three systemic diseases.

Results

There were 12,312 CTS cases within the curated UK Biobank dataset of 401,656 (3.1% prevalence), and the female:male ratio was 1.95:1. CTS cases had, on average, a BMI > 2.0 kg/m² greater than controls. Odds ratios for the association with CTS for three systemic diseases were 2.31 (95% CI 2.17–2.46) for diabetes, 2.70 (95% CI 2.44–2.99) for rheumatoid arthritis, and 1.47 (95% CI 1.38–1.57) for hypothyroidism. Adjusted for BMI, these odds ratios fell to 1.75 (95% CI 1.65–1.86), 2.43 (95% CI 2.20–2.69), and 1.35 (95% CI 1.26–1.43), respectively.

Discussion

We harnessed the size and power of UK Biobank to provide robust replication of evidence for the associations between CTS and female sex, raised BMI, and three systemic diseases, which are only mediated in part by raised BMI.

Incidence and Reappraisal of Known Risk Factors Associated with Carpal Tunnel Syndrome: A Nationwide, 11-Year, Population-Based Study in South Korea

Background and Purpose

Previous studies have revealed various risk factors for carpal tunnel syndrome (CTS), but few large-scale studies have been conducted. We used data from the 11-year, longitudinal, nationwide population-based National Health Insurance Service–National Health Screening cohort to identify the actual risk factors for CTS.

Methods

We collected patients with CTS newly diagnosed using electrodiagnostic studies while excluding radiculopathy, plexopathy, or polyneuropathy, which can be confused with CTS. The crude and standardized incidence rates of CTS were calculated. Univariate and multivariate Cox analyses and the incidence of CTS were used to identify the risk factors for newly diagnosed CTS.

Results

The standardized incidence was 130.8/100,000 person-years based on the World Health Organization World Standard Population as a reference. Multivariate Cox analysis identified that the risk factors for CTS were being middle-aged, female, and obese, and having rheumatoid arthritis and Raynaud's syndrome, whereas gout and hypothyroidism were not risk factors. Diabetes and end-stage renal disease did not show a significant hazard ratio, although it is implicit that the durations of these diseases affect the development of CTS.

Conclusions

This study calculated the incidence of CTS and reappraised the associated risk factors found in previous studies. This information will be helpful for determining the pathophysiology of CTS, and hence aid the establishment of effective new public health policies.

Effects of diabetes mellitus on the rate of carpal tunnel release in patients with carpal tunnel syndrome

The objective of this study was to evaluate the effects of diabetes mellitus (DM) on the rate of carpal tunnel release (CTR) using a large nationwide cohort in Korea and to identify risk factors, including comorbidities and socioeconomic status (SES), associated with CTR. Patients with a primary or secondary diagnosis of carpal tunnel syndrome (CTS; ICD-10 code: G560) were selected and divided into two groups according to the presence of DM. A Cox proportional hazard model was used to assess the rate of CTR between the two groups. To evaluate the influence of demographic factors, comorbidities, and SES on CTR, multivariate Cox proportional hazard regression models were used to adjust for confounding variables. In total, 12,419 patients with CTS were included in the study: 2487 in DM cohort and 9932 in non-DM cohort. DM duration was negatively related with the rate of CTR (HR = 0.89, 95% CI 0.87–0.91) in CTS patients with DM. The rate of CTR was decreased in patients with DM compared to those without DM in the unadjusted model; however, after adjusting for comorbidities, DM had no significant effect on the rate of CTR. Female sex (HR = 1.50, 95% CI 1.36–1.67) correlated with the rate of CTR, and an inverse relationship between the number of comorbidities and CTR was found (p < 0.001) irrespective of DM. Diabetic polyneuropathy (DPN) was not associated with CTR, and we did not find any factors correlating with CTR in DPN patients. We found that CTS patients with more comorbidities or combined with a longer duration of DM were undertreated in real-word practice. Actual outcomes of CTR in CTS patents with various comorbidities should be investigated in future studies for optimal management of CTS.

Association between neuropathy and B-vitamins: A systematic review and meta-analysis

BACKGROUND

Peripheral neuropathy (PN) is common in patients with diseases that are in turn associated with deficiency of the B-vitamins, and vitamin treatment has shown mixed results.

METHODS

This systematic review and meta-analysis studied the association between PN/pain and B-vitamin biomarkers and investigated whether vitamin treatment can ameliorate the symptoms. PubMed and Web of Science were searched according to the study protocol.

RESULTS

A total of 46 observational and seven interventional studies were identified and included in the data synthesis. The presence of PN was associated with lowered B12 levels (pooled estimate [95% CIs] = 1.51 [1.23-1.84], n = 34, Cochran Q Test I²  = 43.3%, p = 0.003) and elevated methylmalonic acid (2.53 [1.39-4.60], n = 9, I²  = 63.8%, p = 0.005) and homocysteine (3.48 [2.01-6.04], n = 15, I²  = 70.6%, p < 0.001). B12 treatment (vs. the comparators) showed a non-significant association with symptom improvement (1.36 (0.66-2.79), n = 4, I²  = 28.9%). Treatment with B1 was associated with a significant improvement in symptoms (5.34 [1.87-15.19], n = 3, I²  = 64.6%, p = 0.059). Analysis of seven trials combined showed a non-significant higher odds ratio for improvement under treatment with the B-vitamins (2.58 [0.98-6.79], I²  = 80.0%, p < 0.001).

CONCLUSIONS

PN is associated with lowered plasma vitamin B12 and elevated methylmalonic acid and homocysteine. Overall, interventional studies have suggested that B-vitamins could improve symptoms of PN. Available trials have limitations and generally did not investigate vitamin status prior to treatment. Well-designed studies, especially in non-diabetes PN, are needed. This meta-analysis is registered at PROSPERO (ID: CRD42020144917).

Socioeconomic factors predicting outcome in surgically treated carpal tunnel syndrome: a national registry-based study

The study aimed to investigate socioeconomic factors in patients with carpal tunnel syndrome (CTS) and to evaluate their impact on outcome following open carpal tunnel release (OCTR). Data from the National Quality Register for Hand Surgery were combined with socioeconomic data (marital status, education level, earnings, migrant status, occupation, sick leave, unemployment, and social assistance) from Statistics Sweden to evaluate OCTRs performed from 2010 to 2016 (total 10,746 OCTRs). Patients completed QuickDASH (short version of Disabilities of Arm, Shoulder and Hand) questionnaires preoperatively (n = 3597) and at three (n = 2824) and 12 months (n = 2037) postoperatively. The effect of socioeconomic factors on QuickDASH scores was analyzed with linear regression analysis. Socioeconomically deprived patients scored higher on the QuickDASH on all occasions than patients with higher socioeconomic status. Being widowed, having a low education level, low earnings, immigrant status, frequent sick leave and dependence on social assistance all increased the postoperative QuickDASH score at 12 months. The change in total score for QuickDASH between preoperative and 12 months postoperatively did not vary between the groups. We conclude that such factors as being widowed, having a lower education level, low earnings, immigrant status, frequent sick leave and social assistance dependence are associated with more symptoms both before and after OCTR for CTS, but these factors do not affect the relative improvement in QuickDASH.

Association of the role of personal variables and nonoccupational risk factors for work-related carpal tunnel syndrome

OBJECTIVES

The purpose of this study was to identify personal variables and nonoccupational risk factors for carpal tunnel syndrome and to analyse the strength of association of these factors.

METHODS

We performed a case-control study with 162 cases and 300 controls. We studied consecutive patients with an electrophysiologically confirmed diagnosis of symptomatic carpal tunnel syndrome. Univariate analysis was performed in the case group and control comparing them for presence of various risk factors. Multivariate analysis was carried out through logistic regression.

RESULTS

The mean BMI and age were greater in the case group than in the control. Multivariate analysis showed that BMI (OR = 1.05, 95% CI = 1.01-1.11) and arterial hypertension (OR = 4.63, 95% CI = 2.88-7.44) were the only factors significantly associated with carpal tunnel syndrome. The age, cigarette smoking and alcohol drinking were at the edge of significance.

CONCLUSIONS

Carpal tunnel syndrome is the most common peripheral neuropathy and has been related to occupational activities in some but not all studies. Clarifying this relationship has important implications for workers' compensation systems. Based on our findings, BMI and arterial hypertension are considered to be the most significant risk factors of carpal tunnel syndrome in our study.

Differences in characteristics of carpal tunnel syndrome between male and female patients

BACKGROUND

Sex difference is known to be a risk factor of carpal tunnel syndrome. However, sex differences with regard to the clinical presentation of carpal tunnel syndrome have not received much attention. Thus, this study aimed to detect any difference in the characteristics of carpal tunnel syndrome between male and female and thereby add new insights into disease prevention.

METHODS

A total of 647 patients (male 193 hands and female 454 hands) with carpal tunnel syndrome who underwent endoscopic or open carpal tunnel release were retrospectively reviewed. The average age at time of surgery was 66 years. Clinical and electrophysiological data of all patients were collected. Six medical conditions, including trigger finger, diabetes mellitus, hemodialysis, hyperlipidemia, hypertension, and obesity were also investigated.

RESULTS

A significant difference was found in the distribution of comorbidities between the male and female groups. Particularly, the prevalence of diabetes mellitus, hemodialysis, and hypertension were significantly higher in the male group than in the female group. Meanwhile, the presence of thenar muscle atrophy was significantly higher in the female group than in the male group.

CONCLUSIONS

Women are more likely to experience carpal tunnel syndrome even though they have no comorbidities. We suggest that carpal tunnel syndrome especially in male patients may be reduced by early intervention for diabetes mellitus. Prospective studies are needed to validate the causal relationship between diabetes mellitus and carpal tunnel syndrome.

Ulnar Nerve Entrapment in Diabetes: Patient-reported Outcome after Surgery in National Quality Registries

BACKGROUND

Ulnar nerve entrapment at the elbow (UNE) is overrepresented in patients with diabetes, but the outcome of surgery is unknown. We aimed to evaluate patient-reported outcome in patients with and without diabetes, and to assess potential sex differences and compare surgical treatment methods.

METHODS

Data on patients operated for UNE (2010-2016, n = 1354) from the Swedish National Registry for Hand Surgery were linked to the Swedish National Diabetes Register. Symptoms were assessed preoperatively (n = 389), and 3 (n = 283), and at 12 months postoperatively (n = 267) by QuickDASH and HQ-8 (specific hand surgery questionnaire-8 questions). Only simple decompressions were included when comparing groups.

RESULTS

Men with diabetes reported higher postoperative QuickDASH scores than men without diabetes. Women scored their disability higher than men on all time-points in QuickDASH, but showed larger improvement between preoperative and 12 months postoperative values. Patients operated with transposition scored 10.8 points higher on QuickDASH than patients who had simple decompression at 12 months (95% confidence interval 1.98-19.6).

CONCLUSIONS

Women with diabetes benefit from simple decompression for UNE to the same extent as women without diabetes. Men with diabetes risk not to benefit from simple decompression as much as women do. Ulnar nerve transposition had a higher risk of residual symptoms compared to simple decompression.

A genome-wide association analysis identifies 16 novel susceptibility loci for carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is a common and disabling condition of the hand caused by entrapment of the median nerve at the level of the wrist. It is the commonest entrapment neuropathy, with estimates of prevalence ranging between 5-10%. Here, we undertake a genome-wide association study (GWAS) of an entrapment neuropathy, using 12,312 CTS cases and 389,344 controls identified in UK Biobank. We discover 16 susceptibility loci for CTS with p < 5 × 10^-8. We identify likely causal genes in the pathogenesis of CTS, including ADAMTS17, ADAMTS10 and EFEMP1, and using RNA sequencing demonstrate expression of these genes in surgically resected tenosynovium from CTS patients. We perform Mendelian randomisation and demonstrate a causal relationship between short stature and higher risk of CTS. We suggest that variants within genes implicated in growth and extracellular matrix architecture contribute to the genetic predisposition to CTS by altering the environment through which the median nerve transits.

Sonographic Measurement of Cross-sectional Area of the Median Nerve in Academic Dentists Without Symptoms or Signs of Carpal Tunnel Syndrome

The objective was to evaluate the distribution of the cross-sectional area (CSA) and flattening ratio (FR) of the median nerve (MN) in asymptomatic academic dentists using ultrasonography (US). Fifty academic dentists underwent US of the MN in transverse section at the pisiform bone level and the CSA (mm2) and FR were measured bilaterally. A CSA of <10 mm2 was considered normal. Paired t-test showed no statistical significance between either hand for CSA and FR ( P> .05). Two independent t-tests showed significant statistical differences ( P= .023) between males and females in the right dominant hand for CSA. Linear correlation analysis showed no significant correlation between CSA and FR for number of years of experience or number of working hours per day in either hand ( P>.05). The CSA was abnormal in the right dominant hand in 20 (40%) of the subjects. These male academic dentists were at increased risk of having an enlarged MN without symptoms.

Impact of smoking and preoperative electrophysiology on outcome after open carpal tunnel release

BACKGROUND

The aim was to evaluate the influence of smoking and preoperative electrophysiology on the outcome of open carpal tunnel release.

METHODS

This retrospective observational study evaluated the outcome in 493 patients (531 hands) primary operated for carpal tunnel syndrome. Data were collected from medical records, health evaluations, and QuickDASH questionnaires before surgery and 1 year after.

RESULTS

Smokers had a higher QuickDASH score preoperatively as well as postoperatively, but the change in total score did not differ. The odds of having a postoperative QuickDASH score >10 were 2.5 times higher in smoking patients than in non-smoking patients. In 124/493 patients (25%), no clinically significant improvement was seen. Normal and extreme preoperative electrophysiology values were associated with higher postoperative scores. No correlation was found between preoperative QuickDASH scores and preoperative electrophysiology values.

CONCLUSIONS

Smokers with carpal tunnel syndrome experience more symptoms preoperatively. Smokers have remaining symptoms after surgery. There is no correlation between preoperative QuickDASH scores and preoperative electrophysiology values. Patients with normal or near to normal preoperative electrophysiology results have limited improvement after surgery.

Carpal Tunnel Syndrome Associated with Oral Bisphosphonates. A Population-Based Cohort Study

BACKGROUND

Bisphosphonates are widely used to prevent osteoporotic fractures. Some severe musculoskeletal reactions have been described with this medication; among them, some cases of carpal tunnel syndrome. Thus, the aim of this study was to explore whether bisphosphonates may be associated with this syndrome.

METHODS

A cohort study was conducted to compare exposed to unexposed women; the exposed group was that composed of women having received at least one prescription of an oral bisphosphonate. For the purpose, we used information from The Health Improvement Network (THIN) database. The outcome of interest was defined as those women diagnosed with carpal tunnel syndrome. A survival analysis was performed; the Cox proportional hazard model was used to calculate hazard ratios and 95% confidence intervals, and to adjust for identified confounding variables.

RESULTS

Out of a sample of 59,475 women older than 51 years, 19,825 were treated with bisphosphonates during the period studied. No differences in age distribution or mean follow-up time were observed between the two groups in comparison. Overall, there were 572 women diagnosed with carpal tunnel syndrome, 242 (1.2%) in the group exposed to bisphosphonates, and 330 (0.8%) in the unexposed. An adjusted hazard ratio of developing carpal tunnel syndrome of 1.38 (95%CI, 1.15-1.64) was found for women exposed to bisphosphonates; no significant changes in the hazard ratios were found when considering different levels of bisphosphonate exposure.

CONCLUSIONS

An increased risk of carpal tunnel syndrome is associated with the use of bisphosphonates in postmenopausal women.

Diabetes as a risk factor for carpal tunnel syndrome: a systematic review and meta-analysis

AIMS

To assess whether diabetes increases the risk of carpal tunnel syndrome and to estimate the magnitude of the association with Type 1 and Type 2 diabetes.

METHODS

We conducted a systematic search of PubMed, Embase, Web of Science, Scopus, Google Scholar and ResearchGate for articles published between 1950 and January 2015. A total of 36 studies (eight cross-sectional, 21 case-control and seven cohort studies) qualified for meta-analysis. We used a random-effects meta-analysis and assessed heterogeneity and publication bias.

RESULTS

The pooled odds ratio of 25 studies (including a total of 92 564 individuals) that reported unadjusted estimates for the association between diabetes and carpal tunnel syndrome or carpal tunnel release was 1.97 (95% CI 1.56-2.49). The pooled odds ratio of 18 case-control or cohort studies consisting of >37 million individuals that reported estimates after controlling for potential confounders was 1.69 (95% CI 1.45-1.96). The association did not differ for Type 1 and Type 2 diabetes. Furthermore, there was no publication bias.

CONCLUSION

This meta-analysis suggests that both Type 1 and Type 2 diabetes are risk factors for carpal tunnel syndrome.

Incidence of Carpal Tunnel Syndrome Requiring Surgical Decompression: A 10.5-Year Review of 2,309 Patients

PURPOSE

To describe the demographics, neurophysiological grading, and incidence of patients undergoing carpal tunnel decompression (CTD) for carpal tunnel syndrome (CTS) in a single region.

METHODS

A retrospective review of 2,313 patients aged greater than 16 years who underwent 3,073 CTDs between January 2000 and August 2010. Crude annual and age- and sex-specific incidences were calculated for the study period. Nerve conduction study grades were recorded and compared with age and sex.

RESULTS

Of the 2,313 patients 1,419 (61%) were female and 890 (39%) were male. Mean age at surgery was 56 years (range, 16-93 years). Females had a significantly higher CTD incidence compared with males (161 vs 108/100,000 person-years, respectively). The highest rates of CTD were seen in the 70- to 79-year age group for both men and women (307/100,000 person-years). Neurophysiological grade increased in severity with increasing age despite using an age-adjusted grading system, with higher grades in patients aged greater than 65 years.

CONCLUSIONS

This study suggests that carpal tunnel syndrome has the highest incidence in older people who tend to have more severe neurophysiological changes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Association between work-related biomechanical risk factors and the occurrence of carpal tunnel syndrome: an overview of systematic reviews and a meta-analysis of current research

BACKGROUND

Occupational risks for carpal tunnel syndrome (CTS) have been examined in various occupations, and several systematic reviews (SRs) have been published on this topic. There has been no critical appraisal or synthesis of the evidence in the SRs. The aims of this study are (1) to synthesise the observational evidence and evaluate the methodological quality of SRs that assess the effect of biomechanical risk factors on the development of CTS in workers, (2) to provide an update of current primary research on this association, (3) to assess a potential dose-response relationship.

METHODS

We searched MEDLINE, EMBASE, CINAHL, the Cochrane Library and the reference lists of articles. The first step covered SRs (1998-2014), and the second step covered current primary studies (2011-2014). The methodological quality of the SRs was evaluated by using the AMSTAR-R tool; primary studies were assessed using a list of 20 items. A qualitative approach was used for synthesising evidence. In addition, we undertook a meta-analysis of the primary studies to determine risk ratios in the dose-response relationship.

RESULTS

We identified ten SRs that covered a total of 143 original studies. Seven primary studies met the criteria for inclusion, of which four provided longitudinal data. We found high quality of evidence for risk factors such as repetition, force and combined exposures. Moderate quality of evidence was observed for vibration, and low quality of evidence was found for wrist postures. An association between computer use and CTS could not be established. Recent primary studies supported the existence of a significant relationship between CTS and repetition, force and combined exposure. The meta-analysis of current research revealed a dose-response relationship between CTS and the American Conference of Governmental Industrial Hygienists' (ACGIH) threshold limit value (TLV) for hand-activity level (HAL). Those between the action limit and TLV and above TLV had RR of 1.5 (95% CI 1.02-2.31) and RR 2.0 (95% CI 1.46-2.82), respectively.

CONCLUSIONS

Occupational biomechanical factors play a substantial role in the causation of CTS. Data from current primary studies on dose-response suggest that the risk of CTS increases with the ACGIH TLV levels.

Linear regression analysis of Hospital Episode Statistics predicts a large increase in demand for elective hand surgery in England

INTRODUCTION

We integrated two factors, demographic population shifts and changes in prevalence of disease, to predict future trends in demand for hand surgery in England, to facilitate workforce planning.

METHODS

We analysed Hospital Episode Statistics data for Dupuytren's disease, carpal tunnel syndrome, cubital tunnel syndrome, and trigger finger from 1998 to 2011. Using linear regression, we estimated trends in both diagnosis and surgery until 2030. We integrated this regression with age specific population data from the Office for National Statistics in order to estimate how this will contribute to a change in workload over time.

RESULTS

There has been a significant increase in both absolute numbers of diagnoses and surgery for all four conditions. Combined with future population data, we calculate that the total operative burden for these four conditions will increase from 87,582 in 2011 to 170,166 (95% confidence interval 144,517-195,353) in 2030.

DISCUSSION

The prevalence of these diseases in the ageing population, and increasing prevalence of predisposing factors such as obesity and diabetes, may account for the predicted increase in workload. The most cost effective treatments must be sought, which requires high quality clinical trials. Our methodology can be applied to other sub-specialties to help anticipate the need for future service provision.

Type 2 diabetes seems not to be a risk factor for the carpal tunnel syndrome: a case control study

Background

Previous studies have shown that the carpal tunnel syndrome seems to occur more frequently in patients with diabetes mellitus and might be associated with the duration of diabetes mellitus, microvascular complications and degree of glycaemic control. Primary aim was to determine if type 2 diabetes can be identified as a risk factor for carpal tunnel syndrome after adjusting for possible confounders. Furthermore, the influence of duration of diabetes mellitus, microvascular complications and glycaemic control on the development of carpal tunnel syndrome was investigated.

Methods

Retrospective, case–control study using data from electronic patient charts from the Isala (Zwolle, the Netherlands). All patients diagnosed with carpal tunnel syndrome in the period from January 2011 to July 2012 were included and compared with a control group of herniated nucleus pulposus patients.

Results

A total of 997 patients with carpal tunnel syndrome and 594 controls were included. Prevalence of type 2 diabetes was 11.5% in the carpal tunnel syndrome group versus 7.2% in the control group (Odds Ratio 1.67 (95% confidence interval 1.16-2.41)). In multivariate analyses adjusting for gender, age and body mass index, type 2 diabetes was not associated with carpal tunnel syndrome (OR 0.99 (95% CI 0.66-1.47)). No differences in duration of diabetes mellitus, microvascular complications or glycaemic control between groups were detected.

Conclusion

Although type 2 diabetes was more frequently diagnosed among patients with carpal tunnel syndrome, it could not be identified as an independent risk factor.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-346) contains supplementary material, which is available to authorized users.

Adipokines as predictors of recovery from upper extremity soft tissue disorders

OBJECTIVES

To study the associations of adipokines with recovery from upper extremity soft tissue disorders (UESTDs) and to explore whether overweight or obesity modify these associations.

METHODS

In this follow-up study, patients seeking medical advice due to incipient upper extremity symptoms with symptom duration <1 month were included (n = 163). The outcome of the study was full or substantial recovery from UESTDs, assessed at 2, 8 and 12 weeks of follow-up. We studied the associations of four adipokines (leptin, adiponectin, resistin and visfatin) with recovery using the generalized estimating equation.

RESULTS

Of the study population, 27.5% reported full or substantial recovery at the 8-week follow-up and 32% at 12 weeks. Higher levels of resistin [odds ratio (OR) = 1.58, 95% CI 1.18, 2.11 for 1 s.d. increase] and visfatin (OR = 1.29, 95% CI 0.94, 1.78 for 1 s.d. increase) at baseline predicted a higher recovery rate at the 8-week follow-up. Moreover, higher levels of leptin predicted a lower rate of recovery (OR = 0.73, 95% CI 0.51, 1.02 for 1 s.d. increase). Adipokines did not predict recovery at 12 weeks. In subgroup analyses, high levels of resistin and visfatin at baseline predicted a higher recovery rate during follow-up in non-overweight patients.

CONCLUSION

The adipokines resistin and visfatin predicted recovery from UESTDs and the associations may be related to stimulation of anti-inflammatory response mechanisms. A higher level of leptin may prevent recovery from UESTDs.

Prevalence of chronic diseases at the onset of inflammatory arthritis: a population-based study

OBJECTIVE

Little is known about the presence of chronic morbidity in inflammatory arthritis (IA) patients at disease onset. Previous studies have been mainly performed in established IA patients or they focus on isolated co-morbid diseases. Our aim was to determine the prevalence of chronic diseases at the onset of IA and to determine whether this is different from the number that one might expect based on age and sex. Patients and methods. A nested case-control study from 2001 to 2010 using data from patient electronic medical records in general practice. Totally, 3354 patients with newly diagnosed IA were included. Each patient was matched on age, sex and general practice with two control patients. In total, 121 different chronic diseases were studied.

RESULTS

In total, 70% of the IA patients had at least one chronic disease at the onset of IA, compared with 59% of the control patients (P < 0.001). The highest prevalence in IA patients was found for cardiovascular diseases (35%), musculoskeletal diseases (27%) and neurological diseases (22%). Compared with the control patients, patients with IA had the highest increased risk for musculoskeletal diseases [odds ratio, OR = 1.7 (95% confidence interval: 1.6-19)] and for neurological diseases [OR = 1.6 (1.4-1.7)] at the onset of IA.

CONCLUSION

At the onset of IA, nearly three-quarters of patients with IA had at least one other chronic disease. Since multi-morbidity affects treatment and outcome of the IA patient, these diseases should be taken into account when treating IA patients.

Differences in risk factors for neurophysiologically confirmed carpal tunnel syndrome and illness with similar symptoms but normal median nerve function: a case-control study

BACKGROUND

To explore whether risk factors for neurophysiologically confirmed carpal tunnel syndrome (CTS) differ from those for sensory symptoms with normal median nerve conduction, and to test the validity and practical utility of a proposed definition for impaired median nerve conduction, we carried out a case-control study of patients referred for investigation of suspected CTS.

METHODS

We compared 475 patients with neurophysiological abnormality (NP+ve) according to the definition, 409 patients investigated for CTS but classed as negative on neurophysiological testing (NP-ve), and 799 controls. Exposures to risk factors were ascertained by self-administered questionnaire. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression.

RESULTS

NP+ve disease was associated with obesity, use of vibratory tools, repetitive movement of the wrist or fingers, poor mental health and workplace psychosocial stressors. NP-ve illness was also related to poor mental health and occupational psychosocial stressors, but differed from NP+ve disease in showing associations also with prolonged use of computer keyboards and tendency to somatise, and no relation to obesity. In direct comparison of NP+ve and NP-ve patients (the latter being taken as the reference category), the most notable differences were for obesity (OR 2.7, 95 % CI 1.9-3.9), somatising tendency (OR 0.6, 95% CI 0.4-0.9), diabetes (OR 1.6, 95% CI 0.9-3.1) and work with vibratory tools (OR 1.4, 95% CI 0.9-2.2).

CONCLUSIONS

When viewed in the context of earlier research, our findings suggest that obesity, diabetes, use of hand-held vibratory tools, and repeated forceful movements of the wrist and hand are causes of impaired median nerve function. In addition, sensory symptoms in the hand, whether from identifiable pathology or non-specific in origin, may be rendered more prominent and distressing by hand activity, low mood, tendency to somatise, and psychosocial stressors at work. These differences in associations with risk factors support the validity of our definition of impaired median nerve conduction.

Smoking and carpal tunnel syndrome: a meta-analysis

INTRODUCTION

We assessed the association between smoking and carpal tunnel syndrome (CTS) and estimated the magnitude of the association with meta-analysis.

METHODS

The PubMed, Embase, Scopus, and SciVerse databases were searched through December 2012. Thirteen studies were included in the meta-analysis.

RESULTS

Cross-sectional studies reported an association between current smoking and CTS (pooled odds ratio (OR) = 1.99, 95% confidence interval (CI) 1.38-2.60, I-squared = 0%). Meta-analyses of case-control studies did not, however, show an association between smoking and CTS (pooled OR = 1.04, 95% CI 0.95-1.12, I-squared = 0.0%) or surgery due to CTS (pooled OR = 0.99, 95% CI 0.82-1.15, I-squared = 0%). Moreover, smoking was not associated with CTS in the meta-analysis of cohort studies (pooled OR = 0.97, 95% CI 0.45-1.50, I-squared = 0%).

CONCLUSIONS

We found an association between smoking and CTS in cross-sectional studies. This association should be explored further in appropriately designed case-control and cohort studies. Muscle Nerve 49:345-350, 2014.