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Journal of Hand Therapy 31 (2018) 129e136

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Journal of Hand Therapy

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JHT READ FOR CREDIT ARTICLE #534. Case Report

Quantitative functional evaluation of a 3Deprinted silicone-embedded prosthesis for partial hand amputation: A case report

Pilar Alvial MD a, Gabriela Bravo Eng b, María Paz Bustos OTa, Gabriel Moreno PO a, Roberto Alfaro MD c, Renata Cancino Eng d, Juan Cristóbal Zagal PhD d,* a Neuro Rehabilitation Institute, Hospital Clínico Mutual de Seguridad, Santiago, Chile b Direction of Innovation and Development, Knowledge Management, Mutual de Seguridad, Santiago, Chile c Department of Physical Medicine and Rehabilitation, Hospital San Pablo, Coquimbo, Chile d Department of Mechanical Engineering, University of Chile, Santiago, Chile

a r t i c l e i n f o

Article history: Received 2 April 2017 Received in revised form 29 August 2017 Accepted 3 October 2017 Available online 1 December 2017

Keywords: Partial hand amputation 3D printing Prosthesis Functional evaluation Soft materials

Conflict of interest: All named authors hereby decla of interest to disclose. This work was supported by the Hospital Clínico Mu

compensation institution. * Corresponding author. Department of Mechanica

Chile, Santiago, Chile. Tel.: þ56 22 9784545; fax: þ56 E-mail address: [email protected] (J.C. Zagal).

0894-1130/$ e see front matter � 2017 Hanley & Bel https://doi.org/10.1016/j.jht.2017.10.001

a b s t r a c t

Study Design: A male patient with partial hand amputation of his nondominant hand, with only stumps of the proximal phalanx of the first and fifth finger, was evaluated. The performance of using two alternative 3D printed silicone-embedded personalized prostheses was evaluated using the quantitative Jebsen Hand Function Test. Introduction: Custom design and fabrication of 3D printed prostheses appears to be a good technique for improving the clinical treatment of patients with partial hand amputations. Despite its importance the literature shows an absence of studies reporting on quantitative functional evaluations of 3D printed hand prostheses. Purpose of the Study: We aim at producing the first quantitative assessment of the impact of using 3D printed silicone-embedded prostheses that can be fabricated and customized within the clinical environment. Methods: Alginate molds and computed tomographic scans were taken from the patient’s hand. Each candidate prosthesis was modeled in Computer Aided Design software and then fabricated using a combination of 3D printed parts and silicone-embedded components. Discussion: Incorporating the patient’s feedback during the design loop was very important for obtaining a good aid on his work activities. Although the explored patient-centered design process still requires a multidisciplinary team, functional benefits are large. Conclusion(s): Quantitative data demonstrates better hand performance when using 3D printed silicone- embedded prosthesis vs not using any aid. The patient accomplished complex tasks such as driving a nail and opening plastic bags. This was impossible without the aid of produced prosthesis.

� 2017 Hanley & Belfus, an imprint of Elsevier Inc. All rights reserved.

Introduction

3D printing promises to transform the way prostheses are made. Its potential for on-demand rapid customization, onsite fabrication, and low cost makes 3D printing the next alternative to commercial solutions. However, there is a lack of quantitative assessments of the performance; these types of prostheses might have on the daily

re that they have no conflicts

tual de Seguridad, a worker’s

l Engineering, University of 22 9784466.

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life of a patient. According to Tanaka and Lightdale-Miric1 there is a need for studies to assess the advantages and disadvantages of noncommercially produced 3D-printed prostheses.

Partial hand amputations are the most common type of work- related amputation worldwide.2 Depending on the degree of severity, these amputations can decrease or limit a person’s ability to perform work and daily life activities. Injured hands are still considered to be functional when more than half of the proximal phalanx is preserved.3 A compromise in the ability to oppose the thumb and digits accounts for a 40%-50% reduction in hand functionality.4,5

This type of amputation can be observed in a variety of clinical patterns, having no standard solution for patients. Most current treatments consist of using a passive prosthesis (being the

rights reserved.

P. Alvial et al. / Journal of Hand Therapy 31 (2018) 129e136130

cosmetic glove the most common solution for transmetacarpal and carpometacarpal amputations in our clinical environment in Chile. An example of this kind of prosthesis can be found in the study by Nayak6) while only in a few cases, myoelectric (for example7,8) or body-powered prosthesis (for example9-13) is being used.

Many methods have been proposed for measuring hand function. While some tests assess function over the basis of qualitative information, others use quantitative data. The Michigan Hand Outcomes Questionnaire14 is an example of a qualitative test.

The Jebsen Hand Function Test15 (JHFT) have been widely used as a quantitative tool to assess hand function. The idea is to evaluate the patient’s performance when addressing 7 motor tasks. The tasks are designed to measure a wide range of unimanual functions that are displayed during activities of the daily living. The test scores performance as the time, measured in seconds, required for each task to be completed. The shorter the time the better the performance is regarded. A maximum of 120 seconds is given to determine whether the task was completed or not. The test should be performed with both hands, using first the nondominant hand. The implementation of this test is also simple and inexpensive as it requires simple objects.

In this case report, a 3D-printed prosthesis designed for a partial hand amputee patient from Hospital Clinico Mutual de Seguridad, Santiago, Chile, is evaluated. We used the JHFT16,17 as a quantitative measure of the effectiveness of using 2 different 3D-printed hand prosthesis vs not using them.

Purpose of the study

The purpose of this study is to assess, through a quantitative scale, the impact of using a partially soft personalized prosthesis, fabricated using a 3D printer, in a case of complex partial hand amputation. The International Classification of Diseases, Tenth Revision include S68.012S (complete traumatic transphalangeal amputation of left thumb sequela), S68.111S (complete traumatic metacarpophalangeal amputation of left index finger sequela), S68.722S (partial traumatic transmetacarpal amputation of left hand sequela), and S68.617S (complete traumatic trans- phalangeal amputation of left little finger sequela) as injury

Fig. 1. (A) Bone structure of the remaining limb taken from a computed tomographic sca transmetacarpal, fourth metacarpophalangeal joint, and fifth proximal phalanx. (B) Three-d

codes related with this study. This work is also related with the International Classification of Function areas d430 (lifting and carrying objects), d440 (fine hand use), and d840-d859 (work and employment).

Patient information

The patient is a 51-year-old male with no comorbid conditions who worked in a toy factory and is right hand dominant. He suffered a crushing of his nondominant (left) hand with a press on September 2014 at work, resulting in the amputation of all fingers at different levels (see Fig. 1). The patient required lavage, debridement and amputation the same day of the accident. He suffered necrosis of one of the dorsal flaps. A partial thickness skin graft was performed two months after the injury to cover the stump. He underwent a full standard rehabilitation process, including occupational therapy, physiotherapy, psychological accompaniment, and was provided with a cosmetic glove and a passive prosthesis. No pain and normal sensibility was associated to his lesion after the rehabilitation process. Full range of motion was conserved for the wrist and elbow. He was not able to grab objects smaller than 1 inch between the stumps of the thumb and the fifth finger. None of the prostheses given were able to restore that function. The surgical team offered a lengthening of the first and fifth digits and a central ray amputation to improve hand function, but he refused both procedures. After 9 months, he started working as a self-employed toymaker and flea market vendor. With the remainders of his hand, he was able to perform all activities of daily living, but especially in his current work environment, he wanted to grasp small objects, such as nails, and to open plastic bags. The ability to accomplish these fine motor tasks became his functional goal.

Informed consent and ethical considerations

The study was approved by the Hospital Clinico Mutual de Seguridad clinical ethical and scientific committee in September 2015. The patient signed a written consent allowing also for photos to be taken and videos to be recorded during the study.

n. The amputation levels correspond to thumb, proximal phalanx, second and third imensional reconstruction of involved soft tissue and skin.

Fig. 2. Prosthesis 1. The prosthesis (A) consists of 2 articulated 3D-printed fingers, one is located on the proximal phalanx of the thumb and the other on the fifth finger. The 3D- printed fingers are held in place, thanks to a leather glove. Nylon wires are used to transmit mechanical tension between the glove and finger tips. The mechanical closure of the first and fifth metacarpophalangeal joints governs the closure of the first and fifth fingertips, respectively. The leather glove is used to strengthen the attachment of the fingers to the hand while allowing the string to be guided along a fixed path (B), starting from the base of the printed finger and passing above the metacarpophalangeal articulation. A 3D- printed silicone-embedded thimble-shaped structure (C) allows prosthesis attachment to the stump. It consists of a 3D-printed hole pattern layer (2 mm thickness) embedded in silicone. This layer allows better bonding with silicone while enabling force transmission. 3D ¼ three-dimensional.

P. Alvial et al. / Journal of Hand Therapy 31 (2018) 129e136 131

Therapeutic intervention

The intervention consisted of producing a good prosthetic solution by following an iterative design process. The method included custom design and fabrication together with quanti- tative evaluation of each solution. The knowledge gained during the evaluation of the first prosthesis served for the design of the second solution. In this case, reaching a good solution required the fabrication of 2 prostheses. The intervention was carried by a multidisciplinary team that included a medical physiatrist, orthoprosthetist, occupational therapist, and mechanical engi- neer. The prostheses were specially designed to allow the pa- tient to pinch an object when using the thumb and fifth finger stumps of his nondominant hand. The patient feedback was taken into high consideration during the overall design process.

Fig. 3. Fabrication method of prosthesis 1. The process uses 3D-printed PLA parts, silicone nylon wire, and elastic wire. The first step (bottom left) is to pour liquid silicone inside a mold silicone following a similar process. On the second step (upper left) the finger is assembled: t The third step (right) is to wrap the finger base with the gloves and sew the PLA wire guides The fourth step is to thread the wire along the dorsal side of the finger, linking the fingertip polylactic acid.

More specifically, the intervention comprised the following specific steps: (1) alginate molds and computed tomographic scans were taken from the patient’s hand while in rest and in closed position. (2) Gypsum replicas of the patient’s non domi- nant hand were fabricated for both positions. (3) Each candidate prosthesis was modeled in computer aided design software and then fabricated using a combination of 3D printed parts and silicone-embedded components fabricated with the aid of 3D printing. (4) Each resulting prototype was tested for correct fit against the gypsum replicas. (5) Each prosthesis was given to the patient for immediate use (without requiring occupational therapy). Hydroxide of aluminum spray was used to prevent sweating between prosthesis and skin. (6) A quantitative assessment of the functional performance of each prosthesis was performed using the Jebsen Hand Function Test.16,17 (7) The best prosthesis was selected for long-term usage.

elastomer (Ecoflex 00e30, Smooth-on, http://www.smooth-on.com/), a leather glove, where the thimble-shaped structure is initially submerged. Finger tips are also made of he phalanx and the thimble structure are joined by a pin and locked with a Seeger ring. along the desired path. A structure with the tensioner system is also sewn to the glove. to the thimble-shaped structure. The final step is to fix the wire to the tensioner. PLA ¼

Fig. 4. Prosthesis 2 (A). This design corresponds to a simplification of the first solution. The underlying thimble structure remains, but it is complemented with an improved supporting structure (B, C). All articulated parts were removed following patient suggestion after trying prosthesis 1 that was found complicated to use. Some improvement to the thimble was made: stretch marks were added, a prolongation was added to the PLA framework which block the metacarpophalangeal joint hyperextension. Moreover, the final version was produced using skin pigmented silicone. PLA ¼ polylactic acid.

P. Alvial et al. / Journal of Hand Therapy 31 (2018) 129e136132

Prosthesis description

Two alternative designs were produced and tested. We named them as prosthesis 1 and prosthesis 2. The experience acquired during the production and evaluation of prosthesis 1 served for the design of the second improved prototype.

Prosthesis 1, shown in Figure 2, consisted of 2 articulated 3D- printed fingers; one is located on the proximal phalanx of the thumb and the other on the fifth finger. Prosthetic fingers were supported by a thimble-shaped 3D printed silicone-embedded structure (see Fig. 3, left). A leather glove allowed maintaining fingers securely attached to the finger stumps. The fingers were actuated by a wire tensioned by the metacarpophalangeal joint movement of those fingers. The fabrication of this prosthesis took nearly 12 hours with a material cost of 8 USD.

Fig. 5. Fabrication method of prosthesis 2. The process uses 3D-printed PLA molds to embed http://www.smooth-on.com/). Fabrication comprises the following steps: Step 1, silicone is optional). Step 2, the interior structure, with a magnet inserted into its tip, is embedded in silicone is cured at room temperature for 1 hour. Finally, molds are removed and the socke

Prosthesis 2, shown in Figure 4, consisted of 2 thimble-shaped tools, directly attached to the patient’s stumps. The tools were made by a 3D-printed polylactic acid (PLA) internal structure embedded in silicone with a neodymium magnet on their tips. The fabrication of this prosthesis (see Fig. 5) took nearly three and a half hours with a material costs under 4 USD. Prosthesis 2 computer aided design files, together with assembly instructions, are avail- able as an open hardware online at https://www.thingiverse.com/ thing:1849852.

We used a desktop Fused Deposition Modeling 3D printer (Creatr 2014, Leapfrog, https://www.lpfrg.com/) for printing the parts. The printer cost is currently $900 USD. We believe similar results can be obtained with other desktop Fused Deposition Modeling 3D printers as long as their printing platform is at least 15 � 15 cm.

the internal 3D-printed structure with silicone elastomer (Ecoflex 00e30, Smooth-on, poured inside the mold that surrounds the exterior of the socket (pigment addition is side the silicone. Step 3, the mold is closed with the finger shaped mold. Step 4, the t is finished. 3D ¼ three-dimensional; PLA ¼ polylactic acid.

Fig. 6. Jebsen Hand Function Test when using patient’s nondominant hand without prosthesis. (A) Writing, (B) card turning, (C) placing small, common objects in a can, (D) simulated feeding, (E) checkers, and (F) placing large light objects in a can.

P. Alvial et al. / Journal of Hand Therapy 31 (2018) 129e136 133

Follow-up and outcomes

Quantitative functional assessment

The JHFT was used to quantify the benefit for the patient of using a 3D-printed silicone-embedded prosthesis. Three tests were executed. Test 1 consisted of using his partially amputated nondominant hand without a prosthesis (see Fig. 6). Test 2 con- sisted of using prosthesis 1 on his nondominant hand (see Fig. 7) and test 3 consisted of using prosthesis 2 on his nondominant hand (see Fig. 8). For each test, the performance of using his dominant hand was measured as a control.

Table 1 displays the results of asking the patient to execute the 7 standardized JHFT tasks under each test condition. The time taken to accomplish a desired task was measured in seconds. A maximum time of 120 seconds was given for the task to be regarded as completed. If the task was not executed during this time, the task was considered to be not accomplished. Shorter time reflects a better performance. The JHFT assesses fine motor skills, ie, weighted and nonweighted hand function tasks per- formed during daily living activities. Fig. 9 displays the nondom- inant hand data using a convenient visualization of bar graph. Using prosthesis 2 (bars in red) shows a clear advantage on most scenarios.

Fig. 7. Jebsen Hand Function Test when using prosthesis 1. (A) Writing, (B) card turning, (C) p light objects.

Results show better performance when using 3D-printed silicone-embedded prosthesis vs not using any aid. Using pros- thesis 2 shows a clear advantage over prosthesis 1 since most evaluation times are considerably smaller.

The patient also tested the use of prosthesis 2 while at work. He was able to execute tasks that he was unable to perform or were performed with difficulty when using his hand without prosthesis. Specifically, he accomplished driving a nail and opening plastic bags.

After continued use of the prosthesis, the patient reported no pain or skin problem related to any prosthesis.

Discussion

In this case report, a quantitative evaluation of using 2 3D- printed silicone-embedded personalized prostheses was per- formed. The JHFT showed an improvement of hand performance when using 3D-printed prostheses for the tasks of card turning (with prosthesis 2), lifting up and holding small objects, simu- lated feeding, as well as when manipulating large and light objects. The patient was able to write only with his nondomi- nant hand without prosthesis, but since the patient was right handed, none of the prototypes was focused on improving writing.

lacing small, common objects, (D) simulated feeding, (E) checkers, and (F) placing large

Fig. 8. Jebsen Hand Function Test when using prosthesis 2. (A) Writing, (B) card turning, (C) placing small, common objects in a can, (D) simulated feeding, (E) checkers, and (F) placing large, light objects in a can.

P. Alvial et al. / Journal of Hand Therapy 31 (2018) 129e136134

For the checkers task, the patient’s stumps were approachable enough to grab them without prosthesis, but any other smaller object could fall. Lifting up large and heavy objects was not possible with or without prosthesis. Improvements were also observed when using prosthesis 2 in work activities such as opening plastic bags and driving a nail, which were declared as his mayor goals.

The prostheses were developed by a team of professionals with medical and engineering knowledge. The patient’s feedback was considered for the final design. The entire process allowed the development of a product targeted closely to patient needs. The final solution allowed for tip grip and better nail fastening. This was achieved, thanks to the aid of a magnet being placed in the tip of the prosthesis. We also considered to further extending the PLA skeleton as it provided better support and avoided thumb hyper- extension, which reduced the grip reliability otherwise.

The functional evaluation was performed right after the pros- thetic prototype was given to the patient, without time for him to get used to it. The immediate improvement shown by the JHFT suggests that the solution is intuitive. These results are consistent with those shown by Nayak et al.6 when using a silicone hand prosthesis and Lee et al.18 with a thumb 3D-printed device.

At our clinical center, patients with these conditions are offered with treatment choices of performing stump lengthening, ray excision, or finger or toe transplant. The patient reported in this case study refused to undergo another surgery to improve his hand function. This prosthetic solution appears to be compatible with any of these techniques and might be used as an intermediate so- lution prior to a final surgery. The ease of adaptation suggest that it can be postsurgically adapted.

Table 1 Jebsen Hand Function Test results

Task Test 1 Test 2

Nondominant hand without prosthesis

Dominant hand (control)

Nondom using pr

Writing a42.1 s 14.1 s Not acco Card turning 10.4 s 4.1 s 11.7 s Small, common objects Not accomplished 6.7 s 54 s Simulated feeding Not accomplished 8.6 s 41.9 s Checkers a3 s 1.7 s 4.2 s Large, light objects Not accomplished 4.9 s 41.9 s Large, heavy objects Not accomplished 4.4 s Not acco

Each cell indicates the time (in seconds) the patient completed the task defined in the left completing a task was 120 s, implying a threshold for regarding a task as accomplished.

a Indicates shorter time between different assessments.

We identified some limitations to the approach. For example, the short lifespan of soft silicone (sharp objects can cut the silicone), silicone also gets dirty quickly (although it is wash- able), and it may pop off when lifting heavy objects. Although the JHFT is a functional test, it does not measure the perfor- mance of the prosthesis in daily living activities. In this case, we focused on a specific patient’s needs. Therefore, this solution could prove less useful for other types of partial hand amputations.

Compared with other 3D-printed prostheses available on the Internet, it is a new patient-centered design, unique in its shape and in the technique of combining 3D-printed PLA with silicone, which offers a solution that can be extrapolated, with minimal adaptations, to the attachment of prostheses for am- putees with the proximal phalanx. For example, the same socket can be used for the attachment of more complicated prostheses, like prosthesis 1 shown in this case report.

Out from this experience, we reflect on the use of 3D printing as a standard technique for producing custom pros- theses in the clinical environment. We observe that the design technique is still far from being automated. The task still re- quires a multidisciplinary team (in our case, an engineer, physician, and occupational therapist). Despite these human resources, benefits are large in terms of customization and speed of the process.

We observed how a simple design (prosthesis 2) was more useful and robust compared with the sophisticated initial mecha- nism (prosthesis 1).

Test 3

inant hand osthesis 1

Dominant hand (control)

Nondominant hand using prosthesis 2

Dominant hand (control)

mplished 13.3 s 46.5 s 13.4 s 5 s a7.2 s 6.9 s 9.7 s a17.3 s 8.7 s 8.9 s a19.8 s 10.2 s 1.9 s 4.4 s 2.9 s 4.9 s a25.3 s 4.2 s

mplished 4.3 s Not accomplished 4.7 s

column. Shorter time indicates better performance. The maximum time available for

Fig. 9. Bar graph representing Jebsen Hand Function Test results. The bars provide a convenient visualization of the nondominant hand results displayed on Table 1. Each bar represents the time (in seconds) the patient required to complete the task indicated at the bottom. Shorter time indicates the task was achieved with better performance. The maximum time available for completing a task was 120 seconds, implying a threshold for regarding a task as accomplished. Using prosthesis 2 (bars in red) shows a clear advantage on most scenarios. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

P. Alvial et al. / Journal of Hand Therapy 31 (2018) 129e136 135

We note that the solution was obtained, thanks to incorporating the patient’s feedback on the design loop. Our study demonstrated the alternative of using a low-cost technology (below 8 USD in material costs) based on silicone-embedded 3D printing that allowed our patient to improve his ability to perform fine motor tasks and reach his main goals. The final design can be expediently adapted to match other patients with similar clinical displays. This result was validated with quantitative data obtained using the JHFT.

Patient perspective

The patient in this case report finds these prostheses very useful, in particular prosthesis 2, especially when he needs to perform activities with both hands. At the end of this study, he continues using prosthesis 2 while at work, specifically for nail fastening. He does not use prosthetic devices for his daily living activities. He also feels satisfied with his participation in this project because he was a pioneer in the use of this technology at our hospital.

References

1. Tanaka KS, Lightdale-Miric N. Advances in 3D-Printed pediatric Prostheses for upper extremity differences. J Bone Joint Surg Am. 2016;98(15):1320e1326.

2. Imbinto I, Peccia C, Controzzi M, Cutti AG, Davalli A, Sacchetti R, Cipriani C. Treatment of the partial hand amputation: An engineering perspective. IEEE Rev Biomed Eng. 2016;9:32e48.

3. Silva Castellanos CA, Muñoz Riaños JE, Garzón Alvarado DA, Landínez Parra NS, Silva Caicedo O. Diseño mecánico y cosmético de una prótesis parcial de mano. Revista Cubana de Investigaciones Biomédicas. 2011;30:15e41.

4. Atkins DJ, Meier RH, eds. Comprehensive Management of the Upper-Limb Amputee. New York: Springer-Verlag New York; 1988.

5. Belter JT, Dollar AM. Performance characteristics of anthropomorphic pros- thetic hands. IEEE Int Conf Rehabil Robot. 2011;2011. https://doi.org/10.1109/ icorr.2011.5975476.

6. Nayak S, Lenka PK, Equebal A, Biswas A. Custom-made silicone hand pros- thesis: A case study. Hand Surg Rehabil. 2016;35(4):299e303.

7. Inc TB. Touch Bionics: Leading Upper Limb Prosthetics Provider. Available at: http://www.touchbionics.com. Accessed October 27, 2017.

8. Vincent Systems. VINCENTpartial. Innovate Partial Hand System. Available at: http://vincentsystems.de/en/prosthetics/vincent-partial/. Accessed October 27, 2017.

9. M-Fingers & Partial M-Fingers for Partial Hands. Available at: http://www.li- beratingtech.com/products/hands/M-Fingers_-_Partial_M-Fingers_for_Partial_ Hands.asp. Accessed October 27, 2017.

10. Didrick M. Didrick medical Inc. Available at: http://www.x-finger.com/. Accessed October 27, 2017.

11. Macduff C. Naked Prosthetics. Available at: http://www.npdevices.com/. Accessed October 27, 2017.

12. Owen J. The Owen replacement finger. Enabling the Future. Available at: http:// enablingthefuture.org/upper-limb-prosthetics/the-owen-replacement-finger/. Accessed October 27, 2017.

13. Brookins N. The knick finger. Enabling the future. Available at: http://ena- blingthefuture.org/the-knick-finger. Accessed October 27, 2017.

14. Chung KC, Hamill JB, Walters MR, Hayward RA. The Michigan Hand Outcomes Questionnaire (MHQ): assessment of responsiveness to clinical change. Ann Plast Surg. 1999;42(6):619e622, 1.

15. Jebsen RH, Taylor N, Trieschmann RB, Trotter MJ, Howard LA. An objective and standardized test of hand function. Arch Phys Med Rehabil. 1969;50: 311e319.

16. Raad J. Jebsen Hand Function Test. Rehab Measures. Available at: http:// www.rehabmeasures.org/Lists/RehabMeasures/DispForm.aspx?ID¼1025. Acc- essed October 27, 2017.

17. Sears ED, Chung KC. Validity and responsiveness of the JebseneTaylor Hand Function Test. J Hand Surg. 2010;35(1):30e37.

18. Lee KH, Kim SJ, Cha YH, Kim JL, Kim DK, Kim SJ. Three-dimensional printed prosthesis demonstrates functional improvement in a patient with an ampu- tated thumb: A technical note. Prosthet Orthot Int. 2016. https://doi.org/ 10.1177/0309364616679315 [Epub ahead of print].

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JHT Read for Credit Quiz: #534

Record your answers on the Return Answer Form found on the tear-out coupon at the back of this issue or to complete online and use a credit card, go to JHTReadforCredit.com. There is only one best answer for each question.

#1. The study design was

a. RCTs b. qualitative c. a case report d. a case series

#2. The patient sustained

a. a partial hand amputation b. a B/E amputation c. an isolated thumb amputation d. a TBI

#3. An important ingredient in the process is PLA which stands for

a. pyrolucite acetate

b. prelysergic analogue c. polyacidic levo acid d. polylactic acid

#4. Post prosthetic application function was tested using the

a. Purdue Pegboard b. Moberg Pick Up Test c. Jebsen Hand Function Test d. Minnesota Manual Dexterity Test

#5. The prostheses consisted of mobile digits of the thumb and lit- tle finger

a. false b. true

When submitting to the HTCC for re-certification, please batch your JHT RFC certificates in groups of 3 or more to get full credit.