Hand disorders demographics in rural areas: A 15-year analysis of demographic characteristics overtime in a stable population

Abstract

Objective

The aim of this study was to determine the incidence of hand disorders in a general rural area, record the demographic characteristics for each condition, and evaluate the tendencies overtime in the incidence of these conditions.

Methods

Using nationwide census data, we identified a health network system serving a geographic area with stable population. Subsequently, we retrospectively analyzed all the patient records (n=731 patients) with hand disorders documented between 2001 and 2015. We performed a retrospective review and collected demographic data for the patients and disorders treated surgically. We calculated the incidence of these conditions based on the census data and performed qualitative and categorical analysis with different demographic and disease-related variables.

Results

We reviewed surgically treated 204 male and 527 female patients with hand disorders. The mean annual incidence was 222.5 cases per 100,000 individuals per year. More than 55% of the patients were between 50 and 69 years old. Trigger finger (TF) accounted for approximately 42% of patients, followed by 35% with carpal tunnel syndrome (CTS). TF and CTS were related to hand dominance, and right hand was affected in 53.4% of the patients.

Conclusion

Hand disorders in a rural area seem to correlate with the occupational sector activities, such as farming and agriculture. CTS was the most common disorder in the past; however, the dramatic increase in the incidence rate of TF made it the most common hand disorder in the last decade. Incidence rates in both males and females showed an increasing trend.

Introduction

Certain types of hand musculoskeletal disorders have become increasingly prevalent during the last two decades (1). Anecdotal evidence suggests a causal relationship between hand pathologic conditions and occupational computer or cellphone use (2). This is true especially among the rural populations that during the previous decades, they had no prior considerable exposure to office, computer, and cellphone occupational practices (2–8).

Stable population areas are defined as geographical areas with a population that remains unchanged overtime, mainly because of no population exchange with other areas (9). In certain areas with stable population, farming and agriculture can be the main employment for majority of the population (10, 11). Over the last two decades, owing to technological progress, an increasing proportion of the population is employed in services and as a result, they are using computers and cellphones with their hands (10, 12, 13). The hospital network that serves this stable population is able to capture and monitor all the hand disorders due to the lack of proximity and accessibility of other health institutions that can perform orthopedic procedures (14). Therefore, the recording and analysis of the hand disorders in a stable population can provide etiological relationship between occupation and hand disorders.

Therefore, our study had three aims: (i) to record the incidence of hand disorders among a rural population, (ii) to evaluate the demographic characteristics for these hand disorders and attempt a correlation for each condition and patients’ occupation, and (iii) to evaluate the changes in the incidence of these conditions overtime in an attempt to characterize the effect of new technology use in hand disorders.

Materials and Methods

Using nationwide census data for the period 2001–2015, we searched different geographic areas to identify the area with the most stable population and agricultural to service employment shift over this period (15, 16). Stable population is defined as a population with relatively stable rate of growth and age composition. As a result, this population remains constant over a prolonged period and can allow evaluations of demographic changes overtime. Indeed, a population of approximately 32,000 with 28,000 above the age of 15 years and almost identical demographic characteristics was evaluated that fulfilled the criteria of constant age-specific fertility and mortality rates. There is also a change in employment with 83.6% people working in agriculture and 8.9% working in office and services in 2001, whereas these percentages became 62.1% and 30%, respectively, in 2015 (15, 16). Institution Review Board approval (No: ES122082018) was obtained, and all the patients involved signed a consent form to participate in the study. Subsequently, 2 orthopedic surgeons retrospectively reviewed all the available data for the operative treatment of hand musculoskeletal disorders in the area’s hospital system in this period. To the best of our knowledge, this is the first and largest single-center retrospective study focusing on 4 hand disorders, which has been conducted in a stable population area in the Mediterranean.

Our inclusion criteria were all men and women of 15 years and older surgically treated for trigger finger (TF), carpal tunnel syndrome (CTS), de Quervain’s disease (DQD), and Dupuytren’s disease (DD) at the Department of Orthopaedic Surgery of the hospital network and residing in the chosen area. For diagnosis, clinical, electromyography (EMG), and radiographic criteria were used as standard of the clinical practice (3, 8, 17). Our exclusion criteria were patients younger than 15 years, non-residents of the geographic area, with revision surgeries, as well as patients who did not provide consent to participate.

Statistical analysis

All the demographic data from the charts of all patients were recorded, including age, gender, affected extremity, and, if applicable, affected finger. For the analysis of the changes overtime, patients’ data were grouped in 3 different time periods, i.e., 2001–2005, 2006–2010, and 2011–2015, each consisting of 5 consecutive years. All the data from the medical records were summarized in a descriptive statistical analysis using the statistical package for the social sciences software, released for Windows the Statistical Package for Social Sciences version 13.0, (SPSS Inc., Chicago, IL, USA). The Pearson test (or Chi-square test) was used for the analysis of qualitative and categorical variables. Student’s t test and Mann-Whitney U test were used for quantitative and continuous variables and the normality of distributions, respectively. A significant difference was defined as p<0.05. The number and incidence rate per 100,000 of population of total hand musculoskeletal disorders were prepared for each year where the most relevant census data were available. This included the censuses of 2001 and 2011 (15, 16). For each incidence rate, simple 95% confidence intervals were computed based on the binomial distribution and large samples.

Results

The geographical area of Grevena, Greece, was recognized as having a stable population based on nationwide data. In total, 731 patients were surgically treated for TF, CTS, DQD, and DD (Figure 1), with 752 operations. Of 731, 204 patients (27.9%) were male and 527 (72.1%) were female with a male to female gender ratio of 1:2.58. The most prevalent hand disorder was TF 308 (42%), followed by CTS 269 (36.7%), DQD 118 (16.1%), and DD 38 (5.2%; Figure 1). The estimated incidence rates of hand disorders for females were always higher than for males (Table 1). The mean age of male patients (64.2±12.5 years) was significantly higher than that of the female patients (58.3±13.6 years) (p<0.001). Interestingly, 54.8% of all the patients were between 50 and 69 years old (Figure 2).

Figure 1.

Number of patients with hand musculoskeletal disorders by gender

Table 1.

Incidence rates of hand musculoskeletal disorders from all patients, by gender

Year	Total population	Population†/Males†/Females†	Total hand disorders
			All	Incidence rate per 100,000 population	Incidence rate, 95% CIa
2001	32.567	28.177	30	106.5	68.4–144.6
		14.060	10	71.1	27.1–115.2
		14.117	20	141.7	79.6–203.7
2011	31.757	27.860	62	222.5	167.2–277.9
		14.389	21	145.9	83.6–208.3
		13.472	41	304.4	211.3–397.4

^aCI: Confidence interval

Figure 2.

Distribution of patients according their age and gender

There were 319 cases of TF in 308 patients with a male to female gender ratio of 1:2.6 (Figure 1). Demographic characteristics are presented in Table 2 with the majority of patients being at the age group of 50–69 years (63%). Figure 3 represents distribution of TF in different digits. The right hand was affected in 57.5% of the patients, and dominant hand was affected in 61.4% patients, which was more often compared with the non-dominant hand (p=0.006).

Table 2.

The distribution of various hand musculoskeletal disorders in relation to gender, age group, and gender ratio

	Age group	M, n (%)	F, n (%)	Total, n (%)	Ma:Fb	p
TFc	15–29	-	7 (3)	7 (2.2)	-
	30–49	13 (15)	29 (12.5)	42 (13.2)	1:2.2
	50–69	51 (58.6)	150 (64.7)	201 (63)	1:2.9
	≥70	23 (26.4)	46 (19.8)	69 (21.6)	1:2
	Total	87 (100)	232 (100)	319 (100)	1:2.7	0.207*
	Age (mean±SDd)	61.9±11.3	59.2±13.1	60±12.7		0.180**
CTSe	15–29	-	3 (1.4)	3 (1.1)	-
	30–49	7 (10.6)	60 (28.7)	67 (24.4)	1:8.6
	50–69	30 (45.5)	98 (46.9)	128 (46.5)	1:3.3
	≥70	29 (43.9)	48 (23%)	77 (28)	1:1.7
	Total	66 (100)	209 (100)	275 (100)	1:3.2	0.001*
	Age (mean±SD)	66.9±12.7	57.4±14.3	59.7±14.5		<0.001***
DQDf	15–29	1 (5.3)	2 (2)	3 (2.5)	1:2
	30–49	3 (15.8)	18 (18)	21 (17.7)	1:6
	50–69	7 (36.8)	58 (58)	65 (54.6)	1:8.3
	≥70	8 (42.1)	22 (22)	30 (25.2)	1:2.8
	Total	19 (100)	100 (100)	119 (100)	1:5.3	0.205*
	Age (mean±SD)	60.7±17.1	57.4±13.3	57.9±14		0.171**
DDg	15–29	1 (2.9%)	-	1 (2.6)	-
	30–49	1 (2.9%)	-	1 (2.6)	-
	50–69	19 (54.2)	3 (75)	22 (56.4)	6.3:1
	≥70	14 (40)	1 (25)	15 (38.4)	14:1
	Total	35 (100)	4 (100)	39 (100)	8.8:1	0.870*
	Age (mean±SD)	66.2±11	63.3±7.3	65.9±10.6		0.357**

^aM: male;

^bF: female;

^cTF: Trigger Finger;

^dSD: standard deviation;

^eCTS: carpal tunnel syndrome;

^gDQD: de Quervain’s diseases;

^gDD: Dupuytren’s disease

In bold letters, the highest incidence rate per age group is shown.

Figure 3.

Distribution of affected digits and digit involvement (in small square top left)

A total of 275 procedures were performed in 269 patients diagnosed with CTS. The demographics are presented in Figure 1. The mean age of male patients was significantly higher (66.9±12.7) compared with that of the female patients (57.4±14.3; p<0.001; Table 2). A total of 263 (97.8%) patients had only 1 hand affected and 6 patients (2.2%) had bilaterally affected hands. The right hand was affected in 52.4% of patients, and dominant hand was affected in 60.2%, which was more often compared with the non-dominant (p=0.02).

In total, 119 surgeries were performed in 118 patients with DQD, with a male to female gender ratio of 1:5.2 (Figure 1). Table 2 presents the demographic data for DQD. The left hand was affected in 50.8% of patients, and dominant hand was affected in 46.6% patients.

There were 39 operations in 38 patients affected by DD with an 8.5:1 ratio of male versus female (Figure 1). There were 12 patients graded as Tubiana I, 16 patients as Tubiana II, 9 patients as Tubiana III, and 3 patients as Tubiana IV. The ring finger was involved in 25 patients, little finger in 14, middle finger in 6, and index finger in 1, with 8 patients have more than 1 finger affected. Figure 2 and Table 3 present age and gender distribution characteristics. The left hand was affected in 60.5% of patients, and dominant hand was affected in 42.1% patients.

The incidence rate of CTS demonstrated 13% increase over the years. TF showed 97% increase, making it the most common hand disorder leaving CTS in the second place. The incidence rate of DQD demonstrated an increase of 13%, whereas that of DD showed 20% increase. Figures 4–7 depict the percentages of the incidence rates of the different hand disorders per gender.

Figure 4.

Incidence rate per 100,000 people for Trigger finger in male (blue) and female (red) population

Figure 5.

Incidence rate per 100,000 people for CTS in male (blue) and female (red) population

Figure 6.

Incidence rate per 100,000 people for DQD in male (blue) and female (red) population

Figure 7.

Incidence rate per 100,000 people for DD in male (blue) and female (red) population

Regarding the changes in the number of cases overtime, for TG, the majority of the increase in men took place in the beginning of the millennium, whereas TF in female patients had a dramatic increase almost 10 years later. For CTS, the incidence rate for males remained unchanged, whereas a 15% increase was seen in females in the last 5 years. For DQD, in the last 5 years, the incidence rate in males increased almost 4-fold (390%). Finally, for DD, 20% increase was recorded for males, whereas 50% decrease in DD was seen in females.

Discussion

This retrospective study on hand musculoskeletal disorders demonstrated that the most common condition undergoing surgery in a rural population was TF with an incidence rate of 89.4/100,000 people, followed by CTS (61.4/100,000), DQD (27.8/100,000), and DD disease (8.8/100,000). The incidence rates found in our series are comparable to those reported in previous studies (1, 6, 19, 20). Moreover, the reported incidence of surgically treated TF and CTS range from 40 to 120 and 35 to 92 patients per 100,000, respectively, with the differences in ranges attributed to the differences in populations (1, 6, 9, 10, 19, 20).

Another important finding of our study was that the dramatic increase in the incidence rate of TF made it the most common hand disorder in the last decade. Incidence rates in both males and females showed an increasing trend with the 3 conditions of CTS, DQD, and DD and demonstrated an increase rate that ranged from 13% to 20%, which corresponds to an annual increase of approximately 1%–2% per year. Interestingly, the increase rate of TF was significantly higher compared to that of the other hand disorders reaching an overall 97% increase, demonstrating an annual increase rate of 6.5%. This rise in incidence rates may represent an actual increase in the occurrence of hand musculoskeletal disorders or, alternatively, an increasing number of diagnoses because of improving levels of diagnostic scrutiny. There are similar reports of increasing incidence of TF and CTS as well as an increase in the percentage of patients requiring surgical intervention (19, 21, 22). More importantly, we found that the incidence of hand disorders was associated with a parallel significant increase of people employed in services requiring computer and cellphone use. It is yet unclear whether that increase is related to the changes in work-related activities; however, our data are in agreement with the reports suggesting that occupational activities that involve computer and cellphone use could be associated with this increase (20, 21, 23).

Another important finding of our study is that women are affected by a hand disorder much more frequently than men are and that the condition typically requires surgical intervention between the ages of 50 and 69 years. Our results confirm the recent reports of gender distribution for pain and surgical intervention (24) as well as findings of a higher prevalence among women (1, 23, 25–27). This was demonstrated for TF, CTS, and DQD with all these conditions reported typically more frequent in females (6, 28, 29). The exception is that DD had a much greater predominance among men (male:female=8.5:1). The higher incidence of DD in men is reported in certain cases (30), but other reports demonstrate a higher incidence in women (31). The different results may be because of the genetic and environmental differences between populations, but additional research is warranted.

Finally, our data are in agreement with regard to certain demographic and patient characteristics with hand disorders. Specifically, the mean age of men (64.2 years) at the time of operation was significantly higher than that of women (58.3 years), in accordance with the literature (26, 31, 32). In TF and CTS, the dominant hand was affected more often compared with the non-dominant hand confirming a potential etiological relationship between hand usage and these conditions (23). We found that the most common digit affected in TF was the thumb followed by the middle, ring, index, and little fingers (4, 33).

Our study had some limitations. This was a retrospective study. In addition, we did not collect data regarding the presence of comorbidities, such as diabetes mellitus, gout, and/or rheumatoid arthritis, that could affect the rate. The third limitation was that our study population involved patients who underwent surgical intervention for their hand condition; thus, careful interpretation was required when trying to identify the incidence of patients treated conservatively. Additional studies with a focus on patient characteristics as well as prospective studies in an attempt to identify the specific causative relationship between occupational practices and hand disorders are important.

The incidence of hand disorders has increased over the last decade, representing a major concern that requires prompt intervention to prevent further disability. TF has become the most common hand disorder exceeding the incidence rate of CTS. There is increasing evidence that occupational use of computer and cellphones may be etiologically related to the increased incidence of hand disorders.

HIGHLIGHTS

• The most common condition undergoing surgery in a rural population was TF with an incidence rate of 89.4/100,000 people, followed by CTS (61.4/100,000), DQD (27.8/100,000), and DD disease (8.8/100,000).

• There is a dramatic increase in the incidence rate of TF over the last decade that made it the most common hand disorder.

• The incidence of hand disorders was associated with a parallel significant increase of people employed in services requiring computer and cellphone use.

• Women are affected by a hand disorder much more frequently than men.

• Surgical intervention for hand disorders is typically required between the ages of 50 and 69 years.