Over the last years, adequate assessment of arm function and prosthetic functioning in children with upper limb reduction deficiency (ULRD) has gained pronounced importance.1–4 Research has shown that the use of standardized instruments adds relevant information on functioning of children with a ULRD.1–3 The prosthetic upper extremity functional index (PUFI) is a validated instrument that was developed to assess the functional status in children with prosthesis.2,3 In 2004, we implemented the authorized Dutch version of the PUFI at the Department of Rehabilitation Medicine of the Erasmus University Medical Centre and more recently, at the University Medical Centre Groningen as a standard procedure to monitor functional outcome and prosthetic management of children with ULRD. This study aims to evaluate the data collected so far, including the first follow-up measurements in individual patients.
MEASUREMENT INSTRUMENT AND PROCEDURE
The PUFI evaluates how a task is performed (method of performance, 6-level nominal scale, for example, active use of the prosthesis or use residual limb), the comparative task performance with and without the prosthesis (ease of performance, 5-point ordinal scale, ranging from “no difficulty” to “unable to complete the task”), and the perceived usefulness of the prosthesis for the activity (3-point ordinal scale: very useful, somewhat useful, not useful). Higher scores represent better performance and higher perceived usefulness of the prosthesis. Sum scores range from 0 to 100. In previous studies, the PUFI showed good validity and test-retest reliability.1–3
There are two versions of the PUFI: the young child version (for those aged 3–6 years) containing 26 items, which is completed by one of the parents, and the older child version (for those aged ≥7 years) with 38 items, which is completed by the child. The two versions have 14 activities in common.
Ease of performance scores with the prosthesis and usefulness are questioned, also when the prosthesis is not used for the specific activity. This has a negative effect on the sum scores, because subjects do not give valid scores on ease of performance and usefulness when they do not use the prosthesis for these activities in their daily lives. For this reason, we established a Prosthetic Activities Score (PAS) in which ease of performance and usefulness are scored for only those activities for which the prosthesis is actually used, actively or passively.1 In nonusers, the assessment was limited to the method of use of the residual limb and ease of performance without prosthesis.
All children visiting the outpatient department of rehabilitation medicine of our centers fill out the PUFI questionnaire at their yearly evaluation. The PUFI results are discussed during the visit by the attending physician.
In this survey, we assessed 40 children (23 girls and 17 boys), 27 children in Rotterdam and 13 children in Groningen with the PUFI, all between 4 and 18 years, mean age of 9.8 years (SD 4.0 years, range 8.3 years). Most children had a congenital deficiency of the upper limb; two of them had an acquired unilateral deficiency. Almost all children had a unilateral deficiency distal from the elbow and proximal from the wrist, one had a transhumeral deficiency, and one had a bilateral deficiency. Fifteen children had a deficiency on the right side and 24 had deficiencies on the left side. Twenty-three were prosthetic users and 17 were nonusers.
For cross-sectional analysis, the last completed assessment of a child was used. We compared the performance of activities for children who wear a prosthesis (users) with those of children who do not (nonusers) using the t-test for independent samples. A paired sample t-test was used to compare the performance of children who have a prosthesis, tested with and without their device. We compared performance of younger (<12 years old) and older users (≥12 years), using a chi-square test or t-test independent samples. The age groups were chosen because adolescents may have different patterns of daily activities.5
The values of p ≤ 0.05 were considered significant and those ≤0.10 were interpreted as a trend.
USE OF PROSTHESIS
In 23 prosthetic users, 19 wore a myoelectric prosthesis and four a passive (cosmetic) prosthesis. Five wore their prosthesis only 0–2 hrs/day during weekdays. Median wearing time during weekdays was 6–10 hrs and during weekends was 3–5 hrs. Wearing time, less than 6 hrs a day and more than 6 hrs a day, did not differ between younger and older users (≥12 years old) during weekdays (p = 0.94) and weekends (p = 0.31).
METHOD OF PERFORMANCE
Users needed help with 2% of the activities and were unable to perform 4% of the activities. In nonusers, respective percentages were 3% and 1%. On an average, the prosthesis was used actively or passively in 51% of all activities. Use of the residual limb in nonusers (88%) was comparable with the total use of the prosthesis and the use of residual limb in users (85%). One-handed performance did not differ between users and nonusers (Table 1). Children younger than 12 years performed more activities with the active use of their prosthesis (31%) compared with older children (11%) (p = 0.02) (Table 2). Top five activities in which the prosthesis was frequently used in young children (3–6 years old) were cycling (69%), eating raisins, opening juice pack, climbing a slide, and pulling up a zipper (each 62%). In older children (7–18 years old), cycling (80%) was an activity in which the prosthesis was most frequently used. Other important activities were drawing a line, opening a bag of crisps, using scissors (each 60%), and opening a sandwich wrap (70%).
EASE OF PERFORMANCE
For prosthetic users, overall scores on ease of performance were moderate, mean 71 (SD 13) (Table 3). The PAS on ease of performance was significantly higher 87 (SD 9; p = 0.000). The PAS for users doing activities with prosthesis did not differ from their overall performance doing the same activities without prosthesis (p = 0.20). Comparing the performance of users with nonusers, the PAS on ease of performance (users) and the ease of performance scores of nonusers are comparable between both groups [mean score 87 (SD 9) vs. 90 (SD 7)] (p = 0.2).
Overall, users perceived their prosthesis moderately useful, mean score was 54 (SD 23). The PAS for usefulness is significantly higher, 78 (SD 16) (p < 0.00). This holds especially true in older children (>12 years old) who perceive the usefulness for specific activities of their prosthesis higher than the usefulness in overall activities: 80 (SD 15) versus 47 (SD 17), (p = 0.00). In younger children (<12 years old) this difference is 77 (SD 18) versus 59 (SD 27) (p = 0.01).
Twelve users had two follow-up measurements, two children had three, and one had five with a mean interval of 1.3 years between the assessments (for further analyses, two children were left out because they had just started or stopped wearing prosthesis).
Overall, there was a tendency of improved ease of performance and usefulness over time. The PAS for ease of performance of the prosthesis improved 5–10 points in four children and three children improved 15–20 points. One child had approximately the same score, four children scored about 5–10 points less, and one about 15 points less (Figures 1, 2). The PAS score regarding usefullness improved 15 points in three children and 25 points in one child. Almost equal scores were found in two children, decreased scores of 5–10 points in four children and decreased scores 25–30 points in two children (Figures 3, 4). To describe trends in time, especially in groups, is not yet possible because of small numbers. In general, improved scores on the PUFI seem to correlate with clinical improvement and effects of a training period. Decreased scores appear mostly in children who report to function well without prosthesis, and in children who experience fitting or technical problems.
Two cases discussed here may illustrate how the PUFI can be used for monitoring over time. A girl with a right-sided ULRD, who uses a myoelectric prosthesis, was measured at the ages of 5, 7, and 8 years, with a score of 88, 85, and 75 points with PAS on ease of performance and a score of 50, 88, and 75 with PAS on usefulness, respectively, showing a decrease at the last visit (number 3 in Figures 2 and 3). Her parents reported no technical problems of the prosthesis or physical problems, but during the interview by the attending physician, they did express concerns regarding her social functioning at school. Also, there were signs that she had problems accepting her reduction deficiency, for which she was referred to the psychologist of the rehabilitation team. The PUFI scores added information that otherwise might not have surfaced.
A boy with a left-sided congenital ULRD, who has a myoelectric prosthesis, was measured at the ages of 3 and 4 years, with sum scores of 70 and 90 on ease of performance and 41 and 68 on usefulness, respectively (number 4 in Figures 1 and 3). In between, his prosthesis was adapted; he did exercises at home and participated in a play group for children with ULRD at the rehabilitation centre. The improved scores correlate with the clinical observation of improved task performance and positive reports by the parents. This implicates that the PUFI was able to detect changes in the functioning of the individual child.
CURRENT APPROACH AND EXPERIENCES
In our rehabilitation centers, children and parents get extensive information about possible advantages, benefits, and disadvantages of different types of prostheses. We try to anticipate what type of treatment and prosthesis would most fit their individual need. This approach is based on our current point of view that not all children need to wear prosthesis to perform well and that a prosthesis can be beneficial for specific or a broad range of activities.6
Since the implementation of the PUFI, we collected information of great value. The PUFI can be used to evaluate method of performance, ease of performance, and usefulness in users of prosthesis on an individual level. It is a useful tool for evaluation of prosthetic training and gives insight into a child's activity performance. The first experiences with multiple measurements in a child may indicate that the PUFI is capable of measuring changes over time and is helpful to evaluate, for example, whether an individual treatment strategy is successful.
RECOMMENDATIONS FOR IMPROVEMENT OF THE PUFI
Although the PUFI is developed for children using a prosthesis, we consider two scales (the method of use and ease of performance) of the PUFI relevant to evaluate children not using a prosthesis, especially because only few other standardized measures are available.1 We look forward to the development of the UFI for the nonprosthetic group.
The newly added PAS will give us a more valid insight into the differences in performance when using or not using a prosthesis and its perceived usefulness. The possibility of PUFI software updates to produce PAS will be discussed with the PUFI development team in Canada.
IMPLICATIONS FOR THE FUTURE
Further research is needed to answer questions such as what is the best age to start to wear a prosthesis, which children will benefit from a prosthesis, and what are psychosocial factors contributing to acceptance of a prosthesis? We state that the PUFI could be used as part of a wide range of measures assessing all different aspects of functioning in children with a ULRD.2
The procedure of measuring groups of patients with the PUFI has not yet been introduced (inter)nationally and needs attention in the near future. Discussion about the interpretation of results and selection of the most relevant PUFI scores between centers and research groups is ongoing.7 When used in a standardized way, the PUFI will be a useful tool for evaluation and research purposes on a larger (inter)- national scale.
The study showed that children with and without prosthesis function well and that children without prosthesis are equally capable of performing activities. The results suggested that the PUFI is capable of measuring change over time in an individual child. The PAS is a necessary adaptation to get valid results on performance with prosthesis. Although there are some issues regarding interpretation and use of the PUFI that need attention, we consider the PUFI to be a useful instrument for clinical judgment and monitoring patients with ULRD. Broader national and international use of PUFI will lead to further improvement of the instrument and will give us the necessary feedback on our treatment and guidance of patients with ULRD.
We thank all children and parents who participated in this study. We also thank V.G. van Heijningen, L.M. Melis-Schrijver (occupational therapists), and K. Huizing (MD) for their contributions.
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3. Buffart LM, Roebroeck ME, Pesch-Batenburg JMFB, et al. Assessment of arm/hand functioning in children with a congenital transverse or longitudinal reduction deficiency of the upper limb. Disabil Rehab
4. Wright VF. Measurement of functional outcome with individuals who use upper extremity devices: current and future directions. J Prosthet Orthot
5. Lambregts SAM, Doornbosch F, Roebroeck ME, et al. Functional Outcome of Adolescents and Young Adults With Congenital Upper Limb Reduction Deficiency[abstract MEC '05]
. Canada: Institute of Biomedical Engineering, University of New Brunswick; 2005:191–195; ISBN: 1-55131-100-3.
6. James MA, Bagley AM, Brasington K, et al. Impact of prostheses on function and quality of life for children with unilateral congenital below-the-elbow deficiency. J Bone Joint Surg Am
7. ULPOM (Upper Limb Prosthetic Outcome Measures): Pediatric Breakout Group Summary from MEC international group, MEC 2008
, Fredericton, Canada: Institute of Biomedical Engineering, University of New Brunswick; 2008.