Performance of the Disabilities of the Arm, Shoulder and Hand Outcome Questionnaire and the Moberg Picking Up Test in Patients With Finger Joint Arthroplasty

Methods 

A chart review was performed to identify all patients with RA treated with silicone joint arthroplasty of metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints between 1978 and 2002. Of 64 consecutive patients, 21 patients had died, 4 patients refused to come because of their poor general condition (severe inflammatory disease, n=2; chronic alcoholism, n=1; mental impairment, n=1), and 2 patients could not be located. The remaining 37 patients (31 women, 6 men) were assessed clinically at an average follow-up time of 104.9 months (range, 8.0–295.5mo). The average age at operation was 52.5 years (range, 23.5–73.5y). The average duration of RA was 17.9 years (range, 0.9–55.9y) at the time of the joint arthroplasty and 25.4 years (range, 2.1–57.8y) at the point of follow-up, respectively. Two patients were interviewed on the telephone; blank subjective scores were sent to them and were returned in both cases. In 51 hands (28 right, 23 left), a total of 140 silicone spacers had been implanted in 107 MCP and 33 PIP joints. Fourteen patients had finger joint arthroplasties in both hands.

Patients were asked to complete the DASH self-report questionnaire (German version 2.0),21 which is a 30-item disability and symptom scale concerning the patient’s health status during the preceding week. The components included under the concept of symptoms are pain, weakness, tingling and numbness, and stiffness. There are 3 dimensions within functional status: physical, social, and psychologic functioning. Components within physical functioning are daily activities, house and yard chores, shopping and errands, recreational activities, self-care, dressing, eating, sexual activities, sleep, and sports and performing arts (optional). Components within social functioning are family care, occupation, and socializing with friends and relatives. Only 1 component, self-image, has been included in psychologic functioning. The items in the questionnaire emphasize upper-extremity activities and are intended to measure disability. The response options for each item are presented as 5- or 7-point Likert scales.14 A scale score ranging from 0 (no disability) to 100 (most severe disability) is calculated. In addition, the disease-specific HAQ10 and the generic health assessing SF-3622 were performed. The Disease Activity Score (DAS),23 which is based on the assessment of the Ritchie Articular Index, number of swollen joints, erythrocyte sedimentation rate, and general health measured on a visual analog scale was evaluated at the follow-up. Clinical measurement included assessment of the ROM and the extension lag of the operated joints; grip strength was measured with a Martin vigorimeter24a using the medium rubber bulb (diameter, 42cm) for global grip testing. We used the MPUT to assess hand function. The test consists of 12 small objects that have to be picked up while being timed with a stop watch. The MPUT was performed according to a standard protocol once, with eyes open only,9 instead of being performed twice, both blindfolded and with eyes open.25 Both hands were tested, the dominant first. Patients who were unable to complete the test received a score of 300 seconds.

Results 

The DASH score is comprised of 2 main outcome parameters: hand function and the impact of the upper-extremity disability on health. Therefore, the results were correlated with both the specific-hand function tests (HAQ, MPUT, grip strength) and the SF-36 general health measurement, respectively. Statistically significant correlations were found for both parameters. Specifically, the correlation coefficient between the HAQ and DASH scores was high (r=.72, P<.01). Also, the MPUT scores of the operated (r=.59, P<.01) and nonoperated hands (r=0.6, P<.01) correlated highly with the DASH scores. However, the grip strength of the operated hands only correlated moderately (r=−.25, P<.09) and the grip strength of the nonoperated hands correlated slightly higher (r=−.45, P<.05) with the DASH scores. The correlation between the DASH and SF-36 subscale scores is presented in table 1.

Table 1. Results of SF-36 Subscale Scores and Their Correlation to DASH Scores

	SF-36 Subscales	N	Mean ± SD	Median	Min	Max	Correlation Coefficient to DASH Scores
	Physical functioning	37	47.16±24.71	50.0	0	85	−.73(P<.01)
	Role–physical	37	32.43±44.04	0.0	0	100	−.53(P<.01)
	Bodily pain	37	43.92±22.37	41.0	0	100	−.53(P<.01)
	General health	37	51.41±18.62	50.0	25	92	−.43(P<.01)
	Vitality	37	46.08±22.36	45.0	0	85	−.51(P<.001)
	Social functioning	37	81.42±21.77	87.5	25	100	−.35(P<.03)
	Role–emotional	37	72.97±41.45	100.0	0	100	−.31(P<.05)
	Mental health	37	71.24±18.66	76.0	16	100	−.57(P<.001)

Abbreviations: Max, maximum value; Min, minimum value.

The MPUT was completed by 33 patients. Two were unable to pick up all items; for those subjects, 300 seconds were recorded. These 2 patients were excluded from comparative analysis between groups and are not presented in table 2. Grip strength was measured in the 35 patients who attended the follow-up visit. There was no statistically significant difference in grip strength or MPUT results between operated and nonoperated or dominant and nondominant hands. The correlations between the MPUT and HAQ scores were moderate to high (operated hands, r=.36, P<.05; nonoperated hands, r=.48, P<.05); the MPUT scores and the grip strength showed moderate correlations (operated hands, r=.29, P<.05; nonoperated hands, r=.26, P>.05).

Table 2. Results of the DASH, HAQ, MPUT, and Grip Strength Scores

	Outcome Measure	N	Mean ± SD	Median	Min	Max
	DASH score	37	44.52±19.14	44.2	5	82.5
	HAQ score	37	1.12±0.76	1.06	0	2.88
	MPUT score: dominant hands (s)	33	19.55±11.88	16.0	9	73.0
	MPUT score: nondominant (s)	33	19.48±12.53	16.0	10	78.0
	MPUT score: operated (s)	47	19.36±11.02	16.0	9	78.0
	MPUT score: nonoperated (s)	19	19.88±14.88	15.0	10	73.0
	Grip strength: dominant hands (bar)	35	0.21±0.19	0.16	0	0.7
	Grip strength: nondominant hands (bar)	35	0.20±0.18	0.18	0	0.68
	Grip strength: operated (bar)	49	0.19±0.17	0.16	0	0.68
	Grip strength: nonoperated (bar)	21	0.24±0.18	0.19	0	0.56

The average ROM for the MCP joints was 43.0°±22.1° for active ROM and 70.8°±24.0° for passive ROM. For the PIP joints, the average active ROM was 46.2°±29.8° versus a passive ROM of 62.4°±34.2°. The active ROM of neither the MCP nor the PIP joints correlated with the DASH or with any of the hand function tests.

The mean DAS was 3.3±1.1. Comparison of the patients with active (DAS ≥3.2) and inactive (DAS <3.2) disease did not reveal any significant differences for any outcome parameter. DAS correlated with DASH scores (r=.29, P<.05) and HAQ scores (r=.43, P<.01) and MPUT scores (operated hands, r=.59, P<.01; nonoperated hands, r=.18, P>.05). The scores and test results are presented in table 2.

Discussion 

This is the first study to use the DASH questionnaire in the outcome assessment of surgical procedures of the hand in patients with RA. This study supports use of the DASH as a measure of health status in this group of patients. The magnitude of the DASH questionnaire’s correlation to the SF-36 is consistent with that seen in previous validity studies. SooHoo et al15 evaluated the construct validity of the DASH by correlation to the most widely used generic instrument, the SF-36, in patients with upper-extremity disorders and found it to be a valid measure of health status in patients with a wide variety of upper-extremity complaints. They found moderate correlations to the SF-36 subscales ranging from .36 to .62. In a study by Beaton and Richards,28 5 shoulder scores correlated in a similar range of .58 to .72 to the SF-36 subscales. In addition to health measurement, the study focused on the evaluation of the functional result. Hand function assessment of patients with RA is generally difficult because multiple adjacent joints of the upper extremity are often impaired. The traditional outcome measure after silicone finger joint arthroplasty is the measurement of the active ROM of the individual joint. However, this might not reflect the functional capacity of the hand in daily life. The importance of finger joint arthroplasty is to maintain or improve function in the rheumatic hand. This is why objective (MPUT, grip strength) and subjective (HAQ) hand function measures were performed and correlated to the DASH to interpret the results in terms of hand function assessment. The statistical results of the present study support the usefulness of the DASH in this context: on the one hand, there was a significant correlation between the DASH and the HAQ, which is a validated functional disability score in the spectrum of rheumatic diseases11; on the other hand, the DASH correlated with the MPUT, which is a simple and time-saving objective test for precision grip. Precision grip is important in performing ADLs such as holding a key or picking up small items. The ability to perform these tasks is not necessarily associated with strong grip force, which might be the reason why the results of grip strength measurement in the present study correlated only partly with the other evaluation tests. The fact that there was no difference between operated and nonoperated hands might lead to the impression that the operations were not successful. However, most patients had had bilateral surgery, leaving only 21 nonoperated hands for a comparison with 49 operated hands. Also, one cannot expect a significantly worse outcome in the nonoperated hands; they probably had not needed surgery due to their satisfactory performance and thus were equal to the operated hands.

Conclusions 

The DASH and MPUT were shown to be practical assessment instruments for patients with RA who underwent hand surgery. The MPUT is time saving and can be completed in about 20 seconds; however, it needs to be performed by a clinician and it tests hand function only. The DASH has the advantage of being self-administered and thus it can be completed by the patient in the waiting room. Moreover, the DASH was shown to evaluate both health aspects and hand function and could be used instead of various time-consuming questionnaires and hand function tests in the outcome assessment of RA hand surgery.