Prevalence of De Quervain disease in infant caregivers and its association with risk factors.

De Quervain's disease (DQD) is commonly reported in mothers during pregnancy up to delayed postpartum period. A cross-sectional study was conducted to assess infant caregivers who visited the paediatric outpatient department or vaccination centre in two hospitals of Lahore, during the months of May and June, 2021. A total of 190 subjects were interviewed directly and assessed by applying Finkelstein's test on both hands. Data was collected using Numeric Pain Rating Scale (NPRS) and Patient Rated Wrist Evaluation (PRWE) from positive subjects. They were asked to report their pain and difficulty level of the affected hand with worsened symptoms. The results exhibited 26.8% prevalence of DQD in a sample size of 190. Infant's age, lifting frequency and hand dominance were proved significant risk factors. However, caregiver's age, history of wrist pain, infant weight and relationship with infant were proved insignificant. Mean PRWE pain and functional scores were 23.14±7.72 and 18.53±6.09, respectively.

Prevalence of endoscopy-related injuries and their impact on clinical practice: a systematic review and meta-analysis.

BACKGROUND: Endoscopy-related musculoskeletal injuries (ERIs) are commonly reported but their exact prevalence and clinical impact remain obscure. We conducted a systematic review and meta-analysis of the current literature aiming to answer these questions. METHODS: The MEDLINE, EMBASE, and SCOPUS databases were searched for studies evaluating ERIs in gastroenterologists and surgeons. The co-primary outcome was the prevalence of ERIs (i.e. carpal tunnel syndrome, de Quervain's tenosynovitis, and hand numbness). The second co-primary outcome was the prevalence of endoscopy-related pain syndromes. RESULTS: 12 studies, including 4563 respondents, were included. The majority of respondents were men (n = 3321; 72.8%) and most were right-handed (86.2%). The career prevalence of carpal tunnel syndrome (pooled from 10 studies) was 5.3% (95%CI 1.5%-8.9%; I 2 = 97.1%), while the prevalence of de Quervain's tenosynovitis (five studies) was 8.5% (95%CI 0.1%-17.0%). The pooled prevalences of thumb pain, neck pain, and back pain were 25.4%, 23.1%, and 19.7%, respectively, but the prevalence varied according to the type of questionnaire used. Only 341/864 respondents (39.5%) had received prior training in ergonomics, while 623/889 respondents (70.1%) expressed a desire for further training in ergonomics. Overall, there is a moderate risk of bias in the present literature. CONCLUSION: ERIs, including carpal tunnel syndrome, de Quervain's tenosynovitis, and endoscopy-related pain, are very common. These injuries can be severe, requiring surgery, and lead to loss of productivity. Most gastroenterologists report an unmet need for training in the proper ergonomics of endoscopy.

Smartphone usage behaviors and their association with De Quervain's Tenosynovitis (DQT)among college students: a cross-sectional study in Guangxi, China.

BACKGROUND: The growing prevalence of smartphone use among college students in China has led to health concerns, including De Quervain's Tenosynovitis (DQT). However, the specific smartphone usage behaviors contributing to DQT remain poorly understood. This study aimed to explore the relationship between smartphone usage behaviors and DQT in college students. METHODS: A cross-sectional study was conducted with 937 students from various majors in Guangxi between September 2021 and April 2022. Participants completed an online questionnaire assessing smartphone usage behaviors and their association with DQT. The Finkelstein test was employed to diagnose DQT. RESULTS: Over half of the college students (52%) tested positive for DQT via Finkelstein's test. Higher levels of smartphone usage time (6-8 h/day: OR = 4.454, 95%CI:1.662-12.229; ≥8 h/day: OR = 4.521, 95%CI:1.596-12.811), phone games (OR = 1.997, 95%CI:1.312-3.040), social media (OR = 2.263, 95%CI:1.795-3.833), and leisure activities (OR = 1.679, 95%CI:1.140-2.475) were significantly associated with an increased risk of DQT. Two specific gestures (Bilateral thumbs, BT: OR = 1.900, 95%CI:1.281-2.817; Bilateral thumbs-horizontal screen, BT-HS: OR = 1.872, 95%CI:1.244-2.818) and two screen sizes (5.0-5.5inch: OR = 2.064, 95%CI:1.108-3.846; 6.0-6.5inch: OR = 2.413, 95%CI:1.125-4.083) also exhibited a higher risk of DQT. Bilateral DQT was observed, with Gesture-BT identified as the primary risk factor. CONCLUSION: Our findings suggest that increased smartphone usage time, phone games, social media, and leisure activities elevate the risk of DQT among college students. Furthermore, two specific gestures and two screen sizes were also linked to a heightened DQT risk. To mitigate DQT development, college students should reduce smartphone usage time and adopt appropriate gestures.

de Quervain's Disease among Patients Visiting the Orthopaedic Outpatient Department of Tertiary Care Center: A Descriptive Cross- sectional Study.

Introduction: de Quervain's disease is one of the common causes of wrist pain. It can cause serious disability and absence from work due to impaired functioning of the wrist and hand. The aim of this study is to find out the prevalence of de Quervain's disease among patients visiting the orthopaedic outpatient department of a tertiary care centre. Methods: This was a descriptive cross-sectional study conducted among patients visiting the orthopaedic outpatient department of a tertiary care centre after receiving ethical approval (IRC KAHS Reference: 078/079/56). This study was conducted from 1 January 2021 to 30 December 2021 from hospital medical records. A convenience sampling method was used. Patients with de Quervain's disease from 16 to 60 years were included in this study. Clinically diagnosis of de Quervain's disease was based on the tenderness of the radial styloid process, tenderness over the first extensor compartment on resisted thumb abduction or extension and positive Finkelstein test. Point estimate and 95% Confidence Interval were calculated. Results: Out of 9600 orthopaedic outpatients, de Quervain's disease was seen in 128 (1.33%) (2.68-4.52, 95% Confidence Interval). Conclusions: The prevalence of de Quervain's disease was similar when compared to other studies conducted in similar settings. Keywords: de Quervain's disease; surgery; tenosynovitis.

Incidence and Risk Factors for Pregnancy-Related de Quervain's Tenosynovitis in South Korea: A Population-Based Epidemiologic Study.

Background: Although pregnant or lactating women have been recognized to be predisposed to de Quervain's tenosynovitis (DQT), there is a lack of epidemiologic evidence. The purpose of this study was to estimate the nationwide incidence of pregnancy-related DQT (PRDQT) and to analyze risk factors using the Korean National Health Insurance (NHI) database. Methods: A retrospective epidemiologic study of pregnant women in South Korea from 2013 to 2017 was conducted using the NHI claims database. Using corresponding diagnostic codes, we identified women diagnosed with DQT during pregnancy or the postpartum period. We calculated the cumulative incidence and analyzed risk factors such as demographics, pregnancy type, delivery method, gestational complications, and comorbidities using multivariate logistic regression analysis. Results: Between 2013 and 2017, 34,342 patients with PRDQT were identified among 1,601,501 pregnant women, representing a cumulative incidence of approximately 2.1%. Age ≥ 30 years, multiple gestation, cesarean delivery, hypertensive disorders in pregnancy, and underlying rheumatoid arthritis were all identified as significant risk factors for the occurrence of PRDQT, whereas diabetic disorders in pregnancy and underlying diabetes mellitus were not. Conclusions: In South Korea, PRDQT was found to affect approximately 2.1 out of 100 pregnant women between 2013 and 2017. The incidence and risk factors identified in this study can be used for clinical consultations and prediction, as well as for development of national health policies.

De Quervain Tenosynovitis: An Evaluation of the Epidemiology and Utility of Multiple Injections Using a National Database.

PURPOSE: We hypothesized that repeat injections are associated with a decreased rate of success and that the success rate of injections correlates with patient comorbidities. METHODS: Using a commercially available insurance database, patients diagnosed with De Quervain tenosynovitis were identified using International Classification of Diseases, Ninth Revision and Tenth Revision codes and stratified by therapeutic interventions, including therapy, injections, and surgery, as well as comorbidities. Injection failure was defined as a patient receiving a repeat injection or subsequent surgical management. Success was defined as no further therapies identified after an intervention. RESULTS: From 2007 to 2017, 33,420 patients with a primary diagnosis of De Quervain tenosynovitis were identified. Women represented 77.5% (25,908) of the total and were 2.6 times more likely to be diagnosed than men. Black patients were more likely to be diagnosed than White patients. Black and White women were found to have the highest incidence (relative risk 3.4 and 2.3, respectively, compared with White men). Age was also significantly correlated with an increased risk of diagnosis of the condition, with a peak incidence at the age of 40-59 years (relative risk, 10.6). Diabetes, rheumatoid arthritis, lupus, and hypothyroidism were associated with an increased risk of diagnosis. Overall, 53.3% of the patients were treated with injections, 11.6% underwent surgery, and 5.2% underwent therapy. Treatment with a single injection was successful in 71.9% of the patients, with 19.7% receiving a repeat injection and 8.4% treated with surgery. The overall success rate of subsequent injections was 66.3% for the second injection and 60.5% for the third. The initial injection had a higher rate of success in diabetics than in nondiabetics; however, the difference (2%) was not clinically relevant. CONCLUSIONS: Although the success rate for the treatment of De Quervains tenosynovitis decreases with multiple injections, repeat injections have a high rate of success and are a viable clinical option. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

A Review of De Quervain's Stenosing Tenovaginitis in the Context of Smartphone Use.

Background: De Quervain tenosynovitis (DQT) has been associated with repetitive movements of the radial first dorsal compartment. Since 2007, smartphones have become ingrained in society. Their functionality is primarily performed by dexterity of the user's thumb(s). The aim of this study was to review the current literature regarding the correlation between DQT and smartphone usage as a systematic review has not previously been presented. Methods: A literature review was conducted electronically using the EMBASE, PubMed, Cochrane and MEDLINE search libraries during May of 2019. Studies eligible for inclusion were English-language studies assessing the link between mobile phone use and DQT. Included studies were required to report on focused outcomes. Only original data studies were included. Case studies, those with data sets collected prior to 2007, foreign language research were excluded. Results: A positive Finkelstein's result within the cohorts was found in a mean of 51.54% of participants. Odds ratios (OR) of 1.5 to 2.3 were found with increasing frequency of text messages and DQT. Females were found to have a higher frequency of text messages daily. Internet browsing and gaming on mobile phones were associated with an OR of 2.21 and 2.61 respectively. DQT associated pain correlated to a mild disruption in daily tasks. On a visual analogue scale, this pain was represented as a 4 out of 10. Conclusions: In conclusion, there appears to be a linear association between frequency of text messages and incidence of DQT. Additionally, there is an association between DQT pain and a mild disruption to daily activities other than mobile phone use.

The association between smartphone addiction and thumb/wrist pain: A cross-sectional study.

Many smartphone users experience pain in the thumb/wrist. This pain can be due to certain types of hand injuries as well as inflammation of the extensor pollicis brevis and the abductor pollicis longus tendon sheaths, known as De Quervain tenosynovitis. The objective of this study was to evaluate the association between smartphone addiction and wrist/thumb pain and to determine the severity of the pain, as well as to calculate the prevalence of De Quervain tenosynovitis among medical students at King Abdulaziz University (KAU) in Jeddah.A total of 387 medical students were enrolled. The smartphone addiction scale-short version (SAS-SV) was used to divide participants into the smartphone addict group and non-addict group. Both groups completed the self-administered patient-rated wrist and hand evaluation (PRWHE) questionnaire to evaluate wrist/hand pain. The Finkelstein test was administered to those who reported pain in the thumb/wrist.Two hundred fifty-seven (66.4%) participants were smartphone addicts; 74 (19.1%) had a positive Finkelstein test. There was a significant correlation between smartphone addiction and high PRWHE scores (P = .036).Our study found the prevalence of smartphones addiction among university students to be high (66%), furthermore a correlation between heavy smartphones usage and hand pain was found which indicates that heavy usage of these devices can cause subclinical effects on the human hand.

Prevalence of a Septated First Dorsal Compartment Among Patients With and Without De Quervain Tenosynovitis: An In Vivo Anatomical Study.

Background: The reported prevalence of a subcompartment housing the extensor pollicis brevis (EPB) tendon within the first dorsal compartment varies widely in the literature, especially regarding the rates of occurrence between genders and among those with and without De Quervain. Based on direct intraoperative observation, we hypothesized that the prevalence of a septated compartment is far greater than previously reported, particularly in those with De Quervain disease. Methods: A prospective analysis of consecutive patients who underwent first dorsal compartment release was carried out. Patients were divided into 2 groups: those with De Quervain tenosynovitis ("De Quervain" group) and a control cohort without a primary diagnosis of De Quervain ("non-De Quervain" group). The intraoperative findings of a single compartment or a separate subcompartment were recorded. The prevalence of a septated compartment was calculated and compared between genders and both patient groups. Results: A total of 102 consecutive patients were included, with a female predominance (74.5%). Overall, 79.4% of patients had a separate subcompartment for the EPB. In the De Quervain cohort, 89.1% had 2 compartments, while 71.4% of non-De Quervain patients had a subcompartment. Men and women had a similar rate of double compartments (80% and 82.4%, respectively). Conclusions: The prevalence of a septated first dorsal compartment is considerably higher than previously reported, most notably in patients afflicted with De Quervain tenosynovitis. This higher rate of septation occurs with a similar prevalence in both men and women. Owing to its consistent presence, the dual first dorsal compartment should be regarded as an expectant anatomical component of the normal wrist.

Relationship between the incidence of de Quervain's disease among teenagers and mobile gaming.

OBJECTIVE: To assess the relationship between the incidence of de Quervain's disease (DD) and mobile gaming. METHODS: We conducted an experimental cross-sectional study and surveyed specialized students with different majors from Xingtai Technician Institute. We applied the stratified clustered sampling method to recruit 500 students aged 16 to 20 years as survey respondents. We diagnosed DD by conducting Finkelstein's test. Chi-square test or Fisher's exact test was used to determine the correlation between different variables and Finkelstein's test results. SPSS 20 statistical software was used to perform all the statistical analyses. RESULTS: Among the five hundred students providing the valid data, there were 302 males and 198 females, with a male-to-female ratio of 3:2. Of them, 216, 159, 77, and 48 reported they played mobile games for < two, two to four, four to six, and > six hours per day, respectively. A total of 246 students (49%) had a positive result in Finkelstein's test. Three hundred and five (61.0%) students played mobile games with their wrist in dorsiflexion position, and among them, 192 had a positive result in Finkelstein's test. The statistical analyses showed that more frequent play, prolonged mobile gaming time per day, and changes in wrist position were significantly correlated with the positive rate of Finkelstein's test (p < 0.05). DISCUSSION: Our results show that the incidence of DD in students in the school was 49.0%. More frequent play, prolonged duration of mobile gaming, and change in wrist position were associated with higher risk of DD. We advocate the restricted time to less than 2.25 hours per day and the frequency in mobile gaming to prevent or reduce DD.

Hand tendinopathy risk factors in Taiwan: A population-based cohort study.

De Quervain's disease, carpal tunnel syndrome (CTS), and trigger finger (digit) are three common pathological conditions of the hand. They are considered overuse syndromes and occur predominantly in females. The prevalence rate and cause-specific risks of these three tendinopathies have not yet been clarified. Data from 41,871 cases listed in the Taiwan National Health Insurance Research Database (NHIRD) from 2010 to 2014 were analyzed. The prevalence rate of these 3 conditions by age, sex, and the risk factors of female-dominant diseases (e.g., osteoporosis, rheumatoid arthritis [RA], and tendinopathy), diabetes mellitus, and hormone antagonist treatment was evaluated. We found that 1.59% of the population developed CTS, 0.49% developed de Quervain's, and 1.07% developed trigger finger. Cases were more likely to develop the three hand tendinopathies if they were female, between 50 and 59 years old, and, according to a multivariate analysis, comorbid with RA, diabetes, using hormone antagonists. Our findings should provide an understanding of the risk factors associated with hand tendinopathy.

Ultrasonographic Evaluation of the Prevalence of an Intracompartmental Septum in Patients With de Quervain's Disease.

It has been reported that more patients with de Quervain's disease who had undergone surgical treatment had a septated dorsal compartment than did normal cadavers. The purpose of this study was to sonographically evaluate the prevalence of an intracompartmental septum in patients with de Quervain's disease and to compare the prevalence between groups categorized by sex, age, and peripartum status. The authors performed an ultrasonographic examination of 112 wrists from 103 patients with de Quervain's disease. The prevalence of a septum-like structure in the first compartment was compared between men and women, between older (≥40 years) and younger (≤39 years) patients, and between pregnant or lactating women and other patients. The prevalence of intracompartmental septum in patients with de Quervain's disease was 61.6% (69 of 112). Of the 69 wrists with an intracompartmental septum-like structure, 53 showed this structure completely through the level of the radial styloid, and 16 showed it partially on the level of the distal radial styloid. There was no significant difference between any 2 groups categorized by the patients' demographics. The prevalence of intracompartmental septation in the patients with de Quervain's disease was higher than the previously reported prevalence in cadavers and lower than that of patients who underwent surgery. This result was consistent with a previous report that patients with a septated dorsal compartment may be more at risk of contracting de Quervain's disease and more prone to failure of nonoperative treatment.

Blood glucose levels in diabetic patients following corticosteroid injections into the hand and wrist.

PURPOSE: To quantify diabetic patients' change in blood glucose levels after corticosteroid injection for common hand diseases and to assess which patient-level risk factors may predict an increase in blood glucose levels. METHODS: Patients were recruited for this case-crossover study in the clinic of fellowship-trained hand surgeons at a tertiary care center. Patients with diabetes mellitus type 1 or 2, who received a corticosteroid injection, recorded the morning fasting blood glucose levels for 14 days after the injection. Fasting glucose levels on days 1 to 7 after injection qualified as case data; levels on days 10 to 14 provided control data. A mixed model with a priori contrasts was used to compare postinjection blood glucose levels with baseline levels. We used a linear regression model to determine patient predictors of a postinjection rise in blood glucose levels. RESULTS: Of 67 patients recruited for the study returned, 40 (60%) completed blood glucose logs. There was a significant increase in fasting blood glucose levels after injection limited to postinjection days 1 and 2. Among patient risk factors in the linear regression model, type 1 diabetes and use of insulin each predicted a postinjection increase in blood glucose levels from baseline, whereas higher glycated hemoglobin levels did not predict increases. CONCLUSIONS: Corticosteroid injections in the hand transiently increase blood glucose levels in diabetic patients. Patients with type 1 diabetes and insulin-dependent diabetics are more likely to experience this transient rise in blood glucose levels. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Systematic review and meta-analysis on the work-related cause of de Quervain tenosynovitis: a critical appraisal of its recognition as an occupational disease.

BACKGROUND: The authors systematically reviewed all of the etiopathologic factors discussed in the literature to verify the classification of de Quervain tenosynovitis on the list of occupational diseases. METHODS: The authors searched Ovid MEDLINE, EMBASE, and the Cochrane Library for articles discussing the cause of de Quervain tenosynovitis. The literature was classified by the level of evidence presented, the etiopathologic hypothesis discussed, the authors' conclusion about the role of the etiopathologic hypothesis, and the first author's professional background. The quality of reporting of the observational studies was evaluated by an extended Strengthening the Reporting of Observational Studies in Epidemiology statement checklist. A meta-analysis of all controlled cohort studies was performed. The Bradford Hill criteria were used to evaluate a causal relationship between de Quervain tenosynovitis and occupational risk factors. RESULTS: A total of 179 references were found, and 80 articles were included. On average, only 35 percent (median, 35 percent; range, 16 to 60 percent) of all items on the extended Strengthening the Reporting of Observational Studies in Epidemiology checklist were addressed per article. The meta-analysis to evaluate the strength of the association between de Quervain tenosynovitis and (1) repetitive, (2) forceful, or (3) ergonomically stressful manual work suggested an odds ratio of 2.89 (95 percent CI, 1.4 to 5.97; p = 0.004). No evidence was found to support the Bradford Hill criteria for a causal relationship between de Quervain tenosynovitis and occupational risk factors. CONCLUSION: No sufficient scientific evidence was provided to confirm a causal relationship between de Quervain tenosynovitis and occupational risk factors. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Upper limb tendinitis and entrapment neuropathy in coal miners.

BACKGROUND: It is well-known that work-related upper limb musculoskeletal disorders, particularly tendinitis and nerve entrapment, remain a difficult and costly problem in industrialized countries. The aim of this study was to evaluate tendinitis and entrapment neuropathy of the upper limb of Turkish coal miners. METHODS: Eighty coal miners and 43 age-matched clerical workers were included in the study. The evaluation procedures included collection of personal and clinical data, physical examination and bilateral electrodiagnostic testing. Subjects were examined to diagnose tendinitis and nerve entrapment of the upper limb. Bilateral median and ulnar nerves conduction tests were performed on all subjects. Data were collected between August 2011 and December 2011. RESULTS: There were 33 subjects with lateral epicondylitis, 10 with medial epicondylitis, and 22 with De Quervain's disease among the coal miners. There were seven subjects with lateral epicondylitis, eight with medial epicondylitis, and four with De Quervain's disease in the control group. The two groups significantly differed in the prevalences of lateral epicondylitis and De Quervain's disease (P = 0.024 and P =0.029, respectively). Sixteen subjects in the coal miners and 12 subjects in the controls had carpal tunnel syndrome (P = 0.66). Thirty-seven subjects in the coal miners had ulnar neuropathy of the elbow (UNE), while four subjects in the controls had UNE; this difference was statistically significant (P < 0.001). CONCLUSION: Lateral epicondylitis, De Quervain disease, and ulnar neuropathy are common work-related upper limb disorders among coal miners.

The study of work behaviours and risks for occupational overuse syndrome.

"Occupational overuse syndrome" is defined as the syndrome of work-related musculoskeletal disorders resulting from repetitive hand posture and motion. We looked at 867 employees in seven different factories to determine the groups suffering from trigger fingers, de Quervain's disease and carpal tunnel syndrome (CTS) from the period of January 2009 to November 2010. The inclusion and exclusion criteria were designated for the subjects in each group. We found the highest prevalence of the syndrome in the rate of CTS development. The differences in the hand spans and the grip strengths between the normal versus the diseased groups were statistically significant. The most common work patterns were a repetitive workload with the hand in a posture of a contracted grasping position. This accounted for 43.1% of the cases of trigger fingers, 38.1% in cases of CTS and this position with a contributing increased speed in the work pattern at 29.8% in the de Quervain's disease patients.

Risk factors for de Quervain's disease in a French working population.

OBJECTIVE: De Quervain's disease (DQD) is a significant cause of musculoskeletal pain among workers. The aim of this study was to assess the relative importance of personal and occupational risk factors for DQD in a working population. METHODS: A total of 3710 workers from a French region were randomly included in the cross-sectional study between 2002-2005. There were 45 subjects with DQD (of these, 5 subjects had a bilateral condition), diagnosed by 83 trained occupational physicians performing a standardized physical examination. Individual factors and work exposure were assessed by a standardized physical and a self-administered questionnaire. Statistical associations between DQD and individual and occupational factors were analyzed using logistic regression modeling in the whole sample and among women. RESULTS: The prevalence rates of uni- or bilateral DQD for the whole, male and female working populations were 1.2% [95% confidence interval (95% CI) 0.9-1.6], 0.6% (95% CI 0.3-0.9) and 2.1% (95% CI 1.4-2.8), respectively. Personal risk factors for DQD were mainly age (1.1 for 1-year increase in age) and female gender [odds ratio (OR) 4.9, 95% CI 2.4-10.1]. Work-related factors were workpace dependent on (i) technical organization (OR 2.0, 95% CI 1.0-4.0), (ii) repeated or sustained wrist bending in extreme posture (OR 2.6, 95% CI 1.3-5.3) and (iii) repeated movements associated with the twisting or driving of screws (OR 3.4, 95% CI 1.7-7.1). No association was found with psychosocial factors. CONCLUSIONS: Personal and work-related factors were associated with DQD in the working population; wrist bending and movements associated with the twisting or driving of screws were the most significant of the work-related factors.

Incidence of de Quervain's tenosynovitis in a young, active population.

PURPOSE: De Quervain's tenosynovitis is thought to occur most frequently in women, with presentation of pain and swelling in the first dorsal extensor sheath. The epidemiology of this extensor tendinitis is not well described. We evaluated the incidence and demographic risk factors for de Quervain's tenosynovitis using a large database of military personnel. METHODS: The Defense Medical Epidemiology Database (DMED) collects International Classification of Diseases, 9th Revision, and Clinical Modification (ICD-9-CM) coding information for every patient encounter occurring for United States military personnel. We queried the DMED system by race, gender, military service, rank, and age for the years 1998-2006 using the ICD-9 code 727.04, limiting data to first presentations. Multivariate Poisson regression was used to estimate the rate of de Quervain's tenosynovitis per 1000 person-years, as well as incidence rate ratios and 95% confidence intervals. RESULTS: There were 11,332 cases of de Quervain's tenosynovitis in the population at risk of 12,117,749 person-years. Women had a significantly higher rate of de Quervain's tenosynovitis at 2.8 cases per 1000 person-years, compared to men at 0.6 per 1000 person-years. Age greater than 40 was also a significant risk factor, with this age category showing a rate of 2.0 per 1000 person-years compared to 0.6 per 1000 in personnel under 20 years. There was also a racial difference, with blacks affected at 1.3 per 1000 person-years compared to whites at 0.8. CONCLUSIONS: In analysis of a large population, we have described the epidemiology of stenosing tenosynovitis of the first extensor compartment. Risk factors for de Quervain's in our population include female gender, age greater than 40, and black race. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.