Differences in orthotic design for thumb osteoarthritis and its impact on functional outcomes: A scoping review

Abstract

Background:

Orthoses are a well-known intervention for the treatment of thumb osteoarthritis; however, there is a multitude of orthotic designs and not enough evidence to support the efficacy of specific models.

Objective:

To examine the influence of different orthoses on pain, hand strength, and hand function of patients with thumb osteoarthritis.

Study design:

Literature review.

Methods:

A scoping literature review of 14 publications reporting orthotic interventions for patients with thumb osteoarthritis was conducted. Functional outcomes and measures were extracted and analyzed.

Results:

In total, 12 studies reported improvements in pain and hand strength after the use of thumb orthoses. Comparisons between different orthotic designs were inconclusive.

Conclusion:

The use of orthoses can decrease pain and improve hand function of patients with thumb osteoarthritis; however, the effectiveness of different orthoses still needs support through adequate evidence.

Clinical relevance

Multiple orthoses for thumb osteoarthritis are available. Although current studies support their use to improve pain and hand function, there is no evidence to support the efficacy of specific orthotic designs. Improved functional outcomes can be achieved through the use of short orthoses, providing thumb stabilization without immobilizing adjacent joints.

Keywords

Orthotics thumb osteoarthritis upper limb

Background

Thumb carpometacarpal osteoarthritis (CMC OA) is one of the most common diseases affecting the hand,¹ with up to 36% of the general population presenting radiographic signs of joint degeneration.² Due to the unique role of the thumb in grasp movements, CMC OA can lead to severe limitations in daily living activities due to pain, limited joint mobility, reduced grip strength, and restricted hand function.^3–5

Although the articular damage caused by OA is a combination of mechanical abnormalities and systemic predisposition,⁶ the lack of joint stability provided by hand muscles and ligaments is highlighted as one of the main contributing factors to CMC OA pathology.^7
–9 Thumb displacement during opposition and pinching movements can lead to increased contact stress between articular surfaces, further compromising the joint integrity and hand function.^7,10,11

Rehabilitation strategies for CMC OA management focus on symptom alleviation, through a combination of exercises, patient education, and the use of orthotic devices.¹²

Considered a primary option of treatment for thumb OA, orthosis interventions aim to provide mechanical support to the CMC, reducing pain and facilitating hand function, without limiting the movement of adjacent, unaffected joints.¹³

Systematic reviews conducted in the past 10 years unanimously reported evidence to support the use of orthoses to reduce hand pain.^{1,3,4,11,14
–16} However, despite the advent of increasing number of quality clinical trials, the impacts of different orthotics for the thumb CMC on hand pain, strength, and hand function are still controversial. Different approaches regarding joint positioning, orthosis length, fabrication material, and dosage for use have given rise to a multitude of orthosis designs, making the comparison of intervention studies a problem.³

Studies that aimed to evaluate the association between the use of orthoses for CMC OA and hand function presented a high-risk bias, which did not support comparisons through a systematic review and meta-analysis.^1,3,4,15 The fact that many studies on orthotics for the CMC joint are not randomized clinical trials restricts the number of publications considered for systematic reviews,⁴ precluding a broad investigation into the current challenges of orthotic research. Scoping reviews can be used to address the many types of evidence available in a particular area, with a broader coverage than traditional review studies.¹⁷

Given the existence of a variety of strategies for the use of orthotics in CMC OA treatment, this scoping study aimed to investigate the influence of different thumb orthosis designs on pain, hand strength, and hand function of patients with CMC OA.

As secondary objectives, we examined the differences described in thumb OA literature regarding orthotics wearing instructions, materials used for fabrication, and patient adherence to orthotic use.

Methods

The five-stage framework for scoping reviews outlined by Arksey and O’Malley¹⁷ (identifying research questions; identifying relevant studies; selecting the study; charting the data; and collating, summarizing, and reporting results) was used in this study. Two independent authors (P.A. and T.B.P.) conducted separate literature searches to identify studies that evaluated the influence of orthotics as a treatment for OA of the thumb CMC. For research questions, this study investigated the following:

What orthotic devices are described for patients with thumb osteoarthritis?

What is the impact of the different existing orthoses in CMC OA patients’ pain, hand strength, and hand function?

Are there outcome changes when using different orthotic designs or materials?

What are the existing trends for orthotic dosage?

Is the dosage related to functional outcome?

MEDLINE, CINAHL, EMBASE, SCOPUS, PEDro, and OTSeeker databases were searched for articles published from their inception until September 2015, with the following keywords: Osteoarthritis, Arthrosis, Thumb, Carpometacarpal Joint, CMC, and Trapeziometacarpal Joint combined with Orthosis, Orthoses, Orthotics, Splints, or Braces.

Manual searches for studies listed in reference sections of relevant articles and additional publications were also conducted, as well as gray literature search to identify all possible studies not found by this search strategy.

The selection of studies was based on (a) the use of orthotics as a treatment modality for patients older than 18 years, diagnosed with thumb CMC OA; (b) which results reported at least one functional outcome, measured by a standardized assessment; and (c) who included a description of the orthotic design selected for the study. Only articles published in English were included. Since the use of orthoses for OA is described by many authors as a primarily conservative treatment,^1,7,11,14,18 studies on interventions with patients who underwent surgical procedures were excluded from the review. Publications that only described orthotic design and rationale guidelines for both orthosis fabrication and CMC OA treatment that did not aim to evaluate the influence of orthoses on functional outcomes were also excluded.

After the initial search, retrieved publications were independently screened for the identification of relevant studies, based on title and abstract. Eligible articles that satisfied the inclusion criteria were cross-referenced and underwent a full-text review.

Key information was collected and organized in a structured form, according to the following headings: first author, title, year of publication, study design, sample size, orthoses details, and wearing instructions. Study objectives and outcomes were also collected. Any discrepancies regarding selected articles were resolved on consensus basis after data extraction.

For this study, the description of orthotic models was based on the Splint Classification System,^19,20 describing orthosis location, involved anatomic parts, kinematic function, the purpose, and number of joints included in the design. Additionally, we included information regarding orthosis type (custom-made or prefabricated), material (thermoplastics, neoprene, elastic fabric, rigid, or soft), and the anatomical base of orthotics, as suggested by O’Brien and McGaha.²¹

Results

Study characteristics

All information regarding selected studies is described in Table 1.

Table 1.

Description of studies and orthotics.

Author	Title	Study design	n	Study purpose	Study outcomes	Simultaneous intervention	Orthoses
		Study design				Simultaneous intervention	Purpose (joints); type	Material and type of support	Anatomical base	Wearing instructions
Hermann et al.²²	Effects of a soft prefabricated thumb orthosis in carpometacarpal osteoarthritis	RCT	55	Objective: Comparison of the influence of orthosis and exercises on hand pain, strength, and function Duration: 2 months Intervention: Control group—hand exercises; Intervention group: Hand exercises and soft, prefabricated thumb orthosis. Evaluations were performed at baseline and at the end of the study	Pain: NRS—no difference between groups; intervention group presented significant results when comparing pain with and without the orthosis Hand strength: Grippit Electronic Instrument—no significant differences between groups Functional outcome: AUSCAN—no significant difference between groups	Hand exercises	Stabilization; (wrist, CMC, MCP) prefabricated	Elastic Fabrifoam (soft)	Hand-based	As much as wanted
Bani et al.²³	A custom-made neoprene thumb carpometacarpal orthosis with thermoplastic stabilization: an orthosis that promotes function and improvement in patients with the first carpometacarpal joint osteoarthritis	CCT	11	Objective: Evaluate the effect of one orthosis on hand pain, strength, and functional outcome Duration: 90 days. Intervention: Patients instructed to wear the orthosis for 3 months. Evaluations at baseline, after 30, 60, and 90 days	Pain: VAS—significant differences (p < 0.01) for all assessments, with improvement compared to baseline Hand strength: JAMAR and PINCH gauge—significant improvement between baseline and consecutive evaluations for both hand and pinch strength. Hand grip strength showed no significant differences between 30–90 days and 60–90 days Functional outcome: DASH—improved and significant functional outcome on all evaluations when compared to baseline. No significant difference between 60 and 90 days	Not informed	Stabilization; (CMC) custom-made	A 3.2-mm thermoplastic piece around the CMC joint (rigid) and neoprene over the hand (soft)	Hand-based	During daily activities and when experiencing symptoms
Maddali-Bongi et al.²⁴	Is an intervention with a custom-made splint and an educational program useful on pain in patients with trapeziometacarpal joint osteoarthritis in a daily clinical setting?	CCT	50	Objective: Evaluate the effect of one orthosis on hand pain, strength, and functional outcome of manual and non-manual workers Duration: 12 months. Intervention: Patients instructed to use the orthosis during 12 months. Evaluations occurred at baseline, 1 month (pain, hand strength, and functional outcome) and after 12 months of intervention (pain)	Pain: NRS—pain reduction was significant between baseline and first evaluation and was maintained after 12 months Hand strength: JAMAR and PINCH gauge—improve significantly between baseline and 1 month evaluations for both groups Functional outcome: Dreiser Scale—significant improvement when comparing the whole group and between manual workers. No significant difference between non-manual workers	Educational program	Immobilization (CMC, MCP) custom-made	1.6 mm thermoplastic (rigid)	Thumb-based	16 h/day during the first month and when needed for the next 11 months
Bani et al.²⁵	The effect of custom-made splints in patients with the first carpometacarpal joint osteoarthritis	CCT	18	Objective: Investigate the effect of one orthosis on hand pain, strength, and hand function Duration: 90 days Intervention: Patients instructed to use the orthosis during 3 months. Evaluations occurred at baseline, 30, 60, and 90 days after the beginning of the intervention	Pain: VAS—improved significantly, with scores decreasing between all evaluations Hand strength: JAMAR and PINCH gauge—pinch grip significantly improved during all evaluations. Hand grip strength showed a significant increase only after 60 days of intervention Functional outcome: DASH—significant increase was observed during all assessments when compared to baseline and between 30–60, 30–90, and 60–90 days	Not informed	Immobilization (CMC) custom-made	3.2 mm thermoplastic (rigid)	Hand-based	During daily activities, removing for sleep, bathing and when in contact with excessive heat
Bani et al.²⁶	Comparison of custom-made and prefabricated neoprene splinting in patients with the first carpometacarpal joint osteoarthritis	RCT	35	Objective: Compare the effect of custom-made and prefabricated orthoses on hand pain, strength, and hand function Duration: 10 weeks Intervention: Three groups of patients, randomly allocated. Evaluations on baseline, sixth, and tenth weeks Control: usual care Group 1: Use of custom-made orthosis for 4 weeks, 2 weeks of washout, and 4 weeks using prefabricated orthosis Group 2: 4 weeks using prefabricated orthosis, 2 weeks washout, 4 weeks using custom-made orthosis	Pain: VAS—control group: no significant difference between baseline and fourth week. Significant reduction of pain on tenth week, compared to baseline Intervention groups: significant decrease in pain between baseline and fourth week for both groups when compared to control, maintained during sixth and tenth weeks. A significant difference was observed at 10 weeks, with the custom-made orthosis obtaining better pain reduction when compared to the prefabricated model Hand strength: JAMAR and PINCH gauge—Control: Significant change at sixth and tenth weeks, with increased pinch strength Intervention groups: Increase in both hand and pinch grip strength at weeks 6 and 10 when compared to control group. No significant differences between intervention groups Functional outcome: DASH—significant improvement for both intervention groups at sixth and tenth weeks when compared to control. No significant differences between different orthotics	Not informed	Orthosis 1: Stabilization (CMC, MCP); prefabricated Orthosis 2: Immobilization (CMC); custom-made	Orthosis 1: 3.5 mm neoprene (soft); Orthosis 2: 1.6 mm thermoplastic (rigid)	Orthosis 1: hand-based; Orthosis 2: hand-based	During daily activities, removing for sleep, bathing and when in contact with excessive heat
Becker et al.²⁷	A prospective randomized comparison of neoprene versus thermoplast hand-based thumb spica splinting for trapeziometacarpal arthrosis	RCT	62	Objective: Compare the impact of two different orthoses on patient upper limb function Duration: 9 weeks (average) Intervention: Two groups of patients Group 1: Prefabricated, orthosis Group 2: Custom-made, thermoplastic orthosis	Pain: VAS, PAAS, and PCS—Both groups presented a pain reduction, but no significant differences were observed between groups Hand strength: JAMAR and PINCH gauge—all subjects improved significantly when compared to baseline. No significant differences between groups Functional outcome: DASH—Improved when compared to baseline, but there was no significant differences between groups	Patients were not forbidden from using any other treatment during the study	Orthosis 1: Stabilization (CMC, MCP); prefabricated Orthosis 2: Immobilization (CMC, MCP); custom-made	Orthosis 1: Neoprene (soft) Orthosis 2: 3.2 mm thermoplastic (rigid)	Orthosis 1: hand-based Orthosis 2: hand-based	As needed for pain relief during daily activities; optional for sleep
Sillem et al.²⁸	Comparison of two carpometacarpal stabilizing splints for individuals with thumb osteoarthritis	RCT	54	Objective: Compare the effect of two different orthoses on hand pain, strength, and function Duration: 12 weeks Intervention: Two groups of patients Group 1: Use of prefabricated orthosis for 4 weeks, 1 week of washout, and 4 weeks using custom-made orthosis. Follow-up 3 weeks later Group 2: Use of custom-made orthosis for 4 weeks, 1 week of washout, and 4 weeks using prefabricated orthosis. Follow-up 3 weeks later	Pain: AUSCAN-Pain—Decreased on both groups, but significant results were obtained only during the use of the custom-made orthosis. Comparison between groups indicated significantly greater pain reduction among patients wearing the custom-made orthosis Hand strength: JAMAR and PINCH gauge—both groups presented improved, but no significant results were obtained Functional outcome: AUSCAN—no significant differences between groups. Significant improvement of function for patients wearing the custom-made orthosis when compared to baseline	None—participants did not receive instructions nor education regarding joint protection or exercises until the end of the study	Orthosis 1: stabilization (CMC, MCP); prefabricated Orthosis 2: stabilization (CMC) custom-made	Orthosis 1: neoprene (soft) Orthosis 2: neoprene (soft) with a 1.6 mm thermoplastic (rigid) around the CMC	Orthosis 1: hand-based Orthosis 2: hand-based	During heavy daily activities and when experiencing symptoms. Optional for nighttime and sleep
Gomes Carreira et al.²⁹	Assessment of the effectiveness of a functional splint for osteoarthritis of the trapeziometacarpal joint on the dominant hand: a randomized controlled study	RCT	40	Objective: Assess the effectiveness of one orthosis on hand pain, strength, and function Duration: 180 days Intervention: Two groups, with evaluations at 45, 90, and 180 days. Both groups performed hand strength tests with and without the orthosis Intervention group: Use of a custom-made orthosis Control group: No treatment during the first 90 days and use of the same orthosis as the intervention group until the end of the study.	Pain: VAS—Significantly reduced with the use of the orthosis, when results were compared with baseline and between groups at 45 and 90 days of intervention. Significant differences were observed among patients in control group after the beginning of orthotic use Intra-group comparisons showed significant differences between the two groups, with improved pain reduction in the intervention group when comparing results at baseline and after 180 days Hand strength: JAMAR and PINCH gauge—no significant differences were observed. Significant reduction on pinch strength for both groups when using the orthosis. Functional outcome: DASH—no significant result between groups and when comparing with baseline results	Not informed	Immobilization (CMC, MCP); custom-made	3.2 mm thermoplastic (rigid)	Hand-based	During daily activities, including work. Remove during rest, bathing, and when in contact with excessive heat.
Rannou et al.³⁰	Splint for base-of-thumb osteoarthritis: a randomized trial	RCT	112	Objective: Evaluate the efficacy of one orthosis on hand pain, pinch strength, thumb mobility, and functional performance Duration: 12 months Intervention: Two groups, evaluated at baseline, after 1, 6, and 12 months Intervention group: Use of custom-made orthosis and usual care conducted by patient’s physicians Control: Usual care	Pain: VAS—no differences between groups at 1 month. Greater reduction for intervention group, with significant difference between groups after 12 months Hand strength: electronic dynamometer—no significant changes Thumb mobility: Kapandji Index—no differences at 1 month. Significant and improved mobility in intervention group after 12 months Functional outcome: Cochin Hand Function Scale—no difference between groups at 1 month. Improved hand function was observed among intervention group at 12 months, with a significant difference when compared to control VAS for patient-perceived disability: no significant differences after 1 month. Significant difference at 12 months, with greater improvement in the intervention group	Pain medication as prescribed by physician	Stabilization (Wrist, CMC, MCP); custom-made	Neoprene (rigid)	Thumb-based	Only at nighttime, for rest
Boustedt et al.³¹	Effects of a hand-joint protection program with an addition of splinting and exercise: 1 year follow-up	CCT	42	Objective: Compare the effect of exercises and orthotic use to a joint protection program. Duration: 6-week intervention, with follow-up after 1 year Intervention: All patients participated in educational group about joint protection, exercises, and disease management Intervention group: Use of two orthoses and home exercises, in addition to educational activities	Pain: VAS—pain at night and during movement significantly decreased in intervention group, after the 6-week intervention and on follow-up Hand strength: Grippit electronic instrument—no significant differences in hand grip and pinch Functional outcome: DASH—significant differences between groups after the intervention and on follow-up, with improved function in intervention group	Educational program, paraffin wax, hand exercises and pain medication prescribed by physician	Orthosis 1: stabilization (CMC); prefabricated Orthosis 2: immobilization (wrist, CMC, MCP); custom-made	Orthosis 1: neoprene (soft) Orthosis 2: 3.2 mm thermoplastic (rigid)	Orthosis 1: hand-based Orthosis 2: forearm-based	All day. Patients were instructed to choose one of the orthoses to use during daytime and to wear the custom-made orthosis during night
Wajon and Ada³²	No difference between two splint and exercise regimens for people with osteoarthritis of the thumb: a randomized controlled trial	RCT	40	Objective: Compare the effects of two different custom-made orthoses and exercises regimen on pain, hand strength, and function Duration: 6 weeks Intervention: control and intervention groups, evaluated at baseline, second and sixth week Control group: Pinch exercises with soft foam, between weeks 2 to 6 and use of Orthosis 1 for 6 weeks Intervention Group: Palmar abduction exercises against gravity, between weeks 2–6 and use of Orthosis 2 for 6 weeks	Pain: VAS—pain reduction in both groups after 2 and 6 weeks, but no significant difference between groups was observed Hand strength: Pinch Gauge—improved pinch strength in both control and intervention groups. No significant difference between groups Functional outcome: Sollerman test of hand function—improved hand function after 2 and 6 weeks among all subjects but no significant differences between groups when comparing to baseline results	Hand exercises	Orthosis 1: Stabilization (CMC, MCP); custom-made Orthosis 2: Immobilization (CMC, MCP); custom-made	Orthosis 1: 3.2 mm thermoplastic (rigid) Orthosis 2: 3.2 mm thermoplastic (rigid)	Orthosis 1: Thumb-based Orthosis 2: Thumb-based	Full time, removing for personal hygiene
Weiss et al.³³	Splinting the degenerative basal joint: custom-made or prefabricated neoprene?	CCT	25	Objective: Compare the responses of patients to two different orthoses for the CMC joint, assessing pain, pinch strength, joint stability, and functional outcomes Duration: 2 weeks Intervention: Participants were randomly assigned to wear a prefabricated or custom-made orthosis for 1 week. After this period, the patients were evaluated and received the other orthotic device to wear for another week. A final assessment was conducted after a total of 2 weeks of intervention	Pain: VAS—Both orthoses reduced pain at rest, with better results observed with the use of the prefabricated orthosis. The prefabricated orthosis also reduced pain during pinching when compared to the use of a custom-made device Hand strength: Greenleaf Solo System Pinchmeter—no significant differences were observed in pinching strength when using orthotics Joint stability: radiographic assessment—significant reduction in CMC joint subluxation with the use of both orthosis, with better results during the use of the custom-made orthotic Functional Outcome: 22 activities self-rating scale (made by the authors)—patients reported better performance at daily activities during the use of the prefabricated orthosis, with increased difficulty when using the custom-made orthosis	Not informed	Orthosis 1: Immobilization (CMC); custom-made. Orthosis 2: Stabilization (wrist, CMC, MCP); prefabricated	Orthosis 1: 3.2 mm thermoplastic (rigid) Orthosis 2: neoprene (soft)	Orthosis 1: Hand-based Orthosis 2: Hand-based	When experiencing symptoms, day or night
Weiss et al.³⁴	Prospective analysis of splinting the first carpometacarpal joint: an objective, subjective, and radiographic assessment	CCT	26	Objective: Compare the effect of two custom-made orthosis on patients’ pain, pinch strength, joint subluxation and performance in activities of daily living Duration: 2 weeks Intervention: Patients were randomly assigned to wear a long or short opponens orthosis for 1 week. After that, patients received the other orthotic device, to use for one more week. Evaluations were performed at baseline and at the end of weeks 1 and 2	Pain: VAS—Both orthoses significantly reduced pain, with no differences observed between the two designs Hand strength: Greenleaf Solo System Pinchmeter—no significant differences were observed in pinching strength Joint stability: Radiographic Assessment—reduced joint subluxation observed during the use of both orthosis, without differences between them Functional outcome: 22 activities self-rating scale (made by the authors)—patients reported better performance in daily activities during the use of the short opponens orthosis, with increasing difficulty when wearing the long orthotic	Not informed	Orthosis 1: Immobilization (CMC); custom-made Orthosis 2: Immobilization (wrist, CMC, MCP); custom-made	Orthosis 1: 3.2 mm thermoplastic (rigid) Orthosis 2: 3.2 mm thermoplastic (rigid)	Orthosis 1: Hand-based Orthosis 2: Forearm-based	When experiencing symptoms, day or night
Buurke et al.³⁵	Usability of thenar eminence orthoses: report of a comparative study	RCT	10	Objective: Compare the differences of three thumb-based, prefabricated orthoses on patients’ pain, pinch strength, hand function, cosmesis, and comfort Duration: 12 weeks Intervention: Patients were evaluated at baseline, after 4 and 8 weeks. Subjects were randomly assigned to use one of three orthosis after each evaluation. A final assessment was conducted at the end of the 12th week	Pain: VAS—No significant differences between three orthoses were observed Hand strength: Pinch Gauge—No differences between the three orthoses Functional Outcome: Green Test—significant differences in hand function, with better performance when using orthosis 3; No significant differences between orthoses 1 and 2 Comfort and Cosmesis: VAS—Orthosis 3 presented better scores in comfort in comparison with the other two orthotic devices. Cosmesis scores indicated a significant preference for orthosis 1	Not informed	Orthosis 1: Stabilization (wrist, CMC, MCP); Prefabricated Orthosis 2: Immobilization (wrist, CMC, MCP); Prefabricated Orthosis 3: Stabilization (wrist, CMC); Prefabricated	Orthosis 1: Thermoplastic (semi-rigid) Orthosis 2: Elastic material with a steel spring busk (rigid) Orthosis 3: Elastic material (soft)	Orthosis 1: Thumb-based Orthosis 2: Thumb-based Orthosis 3: Thumb-based	Not informed

AUSCAN: Australian/Canadian Hand Osteoarthritis Index; DASH: Disabilities of the Arm, Shoulder and Hand; PAAS: Pain Anxiety Symptoms Scale; PCS: Pain Catastrophizing Scale; NRS: numeric rate scale; VAS: visual analog scale; CMC: carpometacarpal joint; MCP: metacarpophalangeal joint; RCT: randomized controlled trial; CCT: controlled clinical trial.

Based on inclusion criteria, 14 articles have been chosen for this review (Figure 1). Publications described eight randomized controlled trial (RCT)^{22,25,27
–31,35} and six controlled clinical trial (CCT) studies.^{23,24,26,32–34} Seven studies investigated only custom-made orthosis,^{23,24,26,29,30,32,34} with five comparing custom-made with prefabricated models,^{25,27,28,31,33} and two studies used exclusively off-the-shelf orthotics.^22,35

Figure 1.

Flow diagram of study selection.

Information regarding the purpose of orthotic intervention and biomechanical rationale supporting selected models was described by five studies,^{24
–26,28,32} all investigating the use of hand- and thumb-based orthoses. While the main objectives of all orthotic interventions consisted in improving the CMC joint stability without hindering the movement of adjacent joints, additional rationale included positioning the thumb in a functional position for pinch,^25,26 improved hand grip and pinch through a more flexible orthosis,²⁸ and prevention of metacarpophalangeal hyperextension to avoid CMC subluxation.^24,32

Five RCTs^{22,25,29
–31} had control groups that used alternative treatments (joint protection techniques, exercises) or no treatment at all, while the other three RCTs^27,28,35 and four CCTs^24,32–34 investigated the influence of two or more different orthotic devices among independent groups. Two studies^23,26 examined the impact of orthoses in the same group during different time periods.

The 14 studies included a total of 580 subjects, with a mean of 41 (standard deviation (SD): ±26.1) participants per study, ranging from 10³⁵ to 112³⁰ subjects. Women represented the majority of participants, with an average of 80.2% of samples composed of females. Mean age of subjects was 56.9 years. One study³³ did not report participant’s age.

To determine the eligibility of patients, 10 studies^{23
–26,29,30,32
–35} required radiographic evidence as inclusion criteria for CMC OA diagnosis. Symptom duration was described by 11 publications,^{22,25,28–35} with a mean time of 2.8 years, ranging from 0.98²⁵ to 15.2 years²² of disease duration. Two studies described symptom duration using time intervals, with the majority of patients reporting clinical conditions between 6 months³³ and 1–5 years.³⁴

All selected studies evaluated the impact of orthoses in hand function and pain at the CMC joint. Nine studies^22
–29,31 evaluated both hand grasp and pinch strength, while five publications^30,32
–35 examined only pinch strength.

Adherence to orthotic use was measured by five studies^23
–26,28 through patients’ report. Mean time of orthoses use ranged from 7.7 to 13 h/day. Total duration of interventions reported by selected studies ranged from 2 weeks^33,34 to 12 months.^24,30

Orthotic devices

Hand-based orthoses were the most common design for the majority of studies,^{22,23,25,26
–29,31,33,34} while long, forearm-based orthoses were described by just two publications.^31,34 Four studies^24,30,32,35 analyzed only thumb-based models (Figure 2).

Figure 2.

Example of orthoses described for the treatment of CMC osteoarthritis: (a) forearm-based orthoses, (b) hand-based models, and (c) thumb-based orthoses.

Selected studies included a total of 23 orthotic designs, all classified as articular according to the Splint Classification System.²⁰ In total, 12 orthoses aimed to stabilize the involved joints while allowing some degree of motion, and 11 designs were fabricated with rigid materials whose objective was to restrict thumb movement.

The inclusion of both the carpometacarpal and metacarpophalangeal joints was the most common strategy for orthotic intervention, with eight models described in seven studies.^{24,25,27
–30,32} Thermoplastics were the most often used material for orthotic fabrication, followed by neoprene and elastic fabrics. Three orthoses described^23,28,35 used a hybrid approach, combining both rigid and soft materials.

Custom-made models comprised 60% of described orthoses, with nine prefabricated devices included in the selected studies.

Wearing instructions

No standard instruction regarding orthotic use was observed among the selected publications. Three studies instructed patients to wear the orthoses during daily activities,^25,26,29 and in seven studies,^{22
–24,27,28,33,34} patients were oriented to use the orthoses whenever they experienced symptoms, as long as necessary. Only one study²⁴ established strict schedules for orthotic use (16 h/day for the first month).

The study conducted by Rannou et al.³⁰ instructed patients to use the orthosis only at nighttime, while Boustedt et al.³¹ and Wajon and Ada³² suggested a full-time orthotics regime for 6 weeks. One study³⁵ did not report orthotics wearing instructions.

Outcome assessment tools

Visual analog scale (VAS) was used for pain assessment in all but three studies: the numeric rate scale (NRS) was used by two studies,^22,24 while one publication²⁸ measured pain using the Australian/Canadian Hand Osteoarthritis Index (AUSCAN). One study²⁷ included the Pain Anxiety Symptoms Scale (PAAS) and the Pain Catastrophizing Scale (PCS) in addition to the VAS for pain evaluation.

Hand grip and pinch strength were evaluated with the JAMAR and/or pinch gauge dynamometers in nine of the selected studies.^{23
–29,32,35} Two studies^22,31 used the Grippit Electronic Instrument, two^33,34 selected the Greenleaf Solo System Pinchmeter, and one³⁰ used a non-described electronic dynamometer.

Hand function and functional status were assessed mostly through standardized questionnaires. The Disabilities of the Arm, Shoulder, and Hand (DASH) was the most used evaluation to measure hand function, selected by six studies.^{23,25
–27,29,31} Other six functional evaluations were used (AUSCAN, Dreiser Functional Index for Hand Osteoarthritis (FIHOA), Cochin Hand Function Scale, Sollerman Test of Hand Function, and Green Hand Assessment), and two studies^33,34 evaluated the impact of orthoses on activity performance through a questionnaire made by the authors.

Except for the Green Hand Assessment, all standardized questionnaires used in the studies measured function in relation to the degree of difficulty reported by patients during the performance of activities of daily living.

Impact of orthotics on pain, hand strength, and hand function

The use of orthoses significantly decreased pain at the CMC joint for patients in 12 of 14 studies reported in selected publications. Only one study²² did not show significant differences in pain during the use of orthotics. Buurke et al.³⁵ did not include any data regarding a baseline evaluation, and therefore, the results of this study could not be considered for this step of the review.

Although the use of orthoses reduced hand pain, comparisons between different orthotic designs were not conclusive. Three studies^25,28,33 showed improved pain reduction during the use of specific models: Sillem et al.²⁸ and Bani et al.²⁵ found better results during the use of two hand-based, custom-made designs involving only the CMC joint when compared to a prefabricated, neoprene orthosis. However, Weiss et al.³³ observed significantly less thumb pain among subjects who wore this same prefabricated orthosis when compared to a rigid thermoplastic design for CMC immobilization. Four studies^27,32,34,35 did not show significant changes in pain between different orthoses.

The use of orthoses showed inconclusive results for both hand grip and pinch strength, with seven studies^{23
–25,27,28,32} reporting patients’ improvement and six studies^{22,30,31,33
–35} showing no significant difference of orthosis use on hand strength.

Gomes Carreira et al.²⁹ observed a decrease in hand grip and pinch strengths when patients were evaluated using the orthotic device. All seven studies that compared different orthotic designs reported no significant changes in hand and/or pinch strength when using different orthoses.

Overall analysis indicated significant improvements in hand function of patients with the use of thumb orthoses: 12 of 14 studies reported that patients presented better functional outcomes during the use of orthotic devices (Table 2).

Table 2.

Average function scores before and after orthotic intervention.^a

Author	Assessment	Baseline, mean (SD)	Post-intervention, mean (SD)
Hermann et al.²²	AUSCAN	4.8 (1.9)	^b
Bani et al.²³	DASH	54.3 (3.3)	61.9 (3.7)
Maddali-Bongi et al.²⁴	Dreiser scale	6.8 (6.0)	4.4 (4.8)
Bani et al.²⁵	DASH	58 (6.3)	71 (7.6)
Bani et al.²⁶	DASH	61.2 (4.9)/58 (6.5)	73.1 (5)/75.2 (12.2)
Becker et al.²⁷	DASH	27.3 (17.9)/29.1 (16.6)	24.8 (15.2)/25.3 (14.6)
Sillem et al.²⁸	AUSCAN	53.1 (^b)/52.6 (^b)	50.4 (^b)/47.1 (^b)
Gomes Carreira et al.²⁹	DASH	39.1 (16.9)	22 (20)
Rannou et al.³⁰	CHFS	19.7 (12.4)	17.8 (10.8)
Boustedt et al.³¹	DASH	37 (^b)	27 (^b)
Wajon and Ada³²	Sollerman test	67.9 (6.5)/69.7 (3.9)	74.8 (6.1)/75.6 (3.3)

AUSCAN: Australian/Canadian Hand Osteoarthritis Index; DASH: Disabilities of the Arm, Shoulder and Hand; CHFS: Cochin Hand Function Scale; SD: standard deviation.

Functional scores presented by subjects allocated in intervention groups. Weiss et al.³³ and Weiss et al.³⁴ did not use a standardized functional assessment. Buurke et al.³⁵ did not conduct an evaluation prior to orthotic intervention.

Data not informed.

Although orthoses improved hand function when compared to situations where no orthotic device was used, only three studies observed significant differences between different orthotic designs. Weiss et al.³³ found better results among patients who wore a prefabricated, hand-based, neoprene orthosis in comparison with a custom-made, thermoplastic device. Another study from the same authors³⁴ compared two custom-made, thermoplastic orthoses and observed improved functional performance when subjects wore a short, hand-based orthosis in comparison to a long, forearm-based one. Buurke et al.³⁵ reported improved functional outcomes between patients who wore a soft, elastic, hand-based, stabilization orthosis when compared to a rigid device.

Differences in wearing instructions seemed to have not influenced the functional outcome in the selected publications. Six studies in which patients were instructed to wear the orthoses if they experienced symptoms related to the OA^{23,24,27,28,33,34} reported improvement in hand function and activity performance while one²² found no significant functional change. Studies that established a full-time schedule for orthotic use also observed improvement in daily activities performance, whether the recommendations instructed use day and night^31,32 or only during sleep time.³⁰

The five studies that measured patients’ orthotic adherence found a mean time of use of 8.8 h/day, and all these studies observed significant functional improvements among patients in short (4 weeks)²³ and long term use (after 1 year).²⁴ However, the impact of orthotic adherence and time of use on hand function, pain, and grip strength was not analyzed by any of the studies.

Other outcomes

Joint stability, perceived disability, thumb mobility, and orthotic cosmesis were also investigated in four studies.^30,33
–35

Weiss et al.^33,34 evaluated the impact of orthoses on thumb subluxation through radiographic assessment and observed improved joint positioning during the use of orthoses, with a better alignment provided by custom-made, rigid designs.

Rannou et al.³⁰ measured patient-perceived disability using the VAS, observing significant improvement among patients who wore orthosis for 12 months. The authors also evaluated thumb mobility through the Kapandji Index and observed significantly increased joint mobility after 1 year of orthosis use.

Buurke et al.³⁵ noted a significant cosmetic preference for a semi-rigid, thermoplastic, prefabricated orthoses in comparison to two other off-the-shelf orthoses.

Long-term results

Although most of the studies had a mean time of intervention below 6 months, four studies^24,29
–31 reported that patients maintained outcome improvements at long-term follow-up: Boustedt et al.³¹ observed pain reduction and increased hand function at 6 weeks and after 1 year of intervention, while Rannou et al.³⁰ found significant improvement in pain, joint mobility, and function only after 12 months of orthotic use. Two other studies^24,29 observed that pain reduction was maintained within 6 months²⁹ and after 1 year²⁴ of orthosis use, but did not find improvements in other outcomes measured.

Simultaneous treatment

Seven publications included information regarding the use of other treatment modalities during the studies’ duration. Concurrent interventions during orthosis use included hand exercises,^22,32 educational programs,²⁴ use of prescribed pain medication³⁰ and a combination of multiple treatments.^27,31 Sillem et al.²⁸ did not provide patients with exercises or education programs until the final assessment, but did not inform whether patients were allowed to use other treatment during the orthotic intervention period.

Discussion

This scoping review investigated the influence of different orthoses on pain, hand strength, and functional outcomes of patients with CMC OA. Although the literature provides evidence to support the use of thumb orthoses to decrease pain and improve hand function, there is no sufficient investigation on the impact of different orthotic designs and wearing strategies on patients’ pain, hand strength, and function.

The variety of orthoses and thus the impossibility to compare studies’ results were also highlighted by previous reviews: the wide range of orthosis designs could be related to the challenge to obtain the optimal balance between joint stabilization and movement during orthotic fabrication,^13,16 but might also suggest the absence of biomechanical rationale behind orthotic interventions for the thumb. In a systematic review conducted in 2011, only one of nine RTCs included a detailed description of the orthosis’ purpose.¹⁵ Despite the increasing number of studies including this information, the majority of the publications still do not clearly state the reasoning used for orthotic fabrication and intervention.

Pain is the most important symptom for patients with hand OA,³⁶ significantly contributing to occupational restrictions among this population.⁷ The reduction in pain obtained through orthosis use is underlined by all review studies published in the last 10 years^{1,3,4,11,14
–16} and by the guidelines provided by the European League Against Rheumatism (EULAR).⁵ However, there are no conclusive results regarding different orthoses: meta-analyses studies^3,4,15 reported that orthoses reduce pain when compared to baseline assessments, but no significant differences were observed among groups who wore two distinct orthoses.

Results observed in this scoping review also suggest a positive effect of orthoses on hand function of CMC OA patients: 12 of 14 studies observed improvements in activity performance after orthotic interventions but only three found significant differences between unique orthoses. The results are similar to the findings of previous systematic reviews^3,4,15 which observed moderate evidence to support the use of orthoses to improve hand function, but were unable to determine whether or not a specific model provides better functional outcomes.

Contrasting to the positive results for pain and hand function, data regarding the influence of orthoses on hand grip and pinch were inconclusive. Although half of the selected studies observed improved hand strength after orthotic use, the other seven studies did not find significant changes, with one study reporting decreased grip and pinch strength when patients wore orthoses.²⁹

Despite the fact that few studies showed significant changes in different orthotic designs on patients’ functional outcomes, the literature suggests that improved performance in activities of daily living and pain reduction can be achieved through the use of short, hand-based orthoses providing adequate stabilization to the CMC without immobilizing adjacent joints.^{25,28
–30,34} Although not conclusive, it appears that orthoses made with more flexible materials can also facilitate their use during daily living activities, with no increase in pain.^23,28,33

These results agree with a minimalistic approach advocated by some authors,^13,37,38 in which the orthotic design aims to support the CMC joint, allowing complete movement of the wrist and the metacarpophalangeal joints, having a minimum influence on patients’ activities and occupations.

Implications for clinicians

There is enough evidence to support the use of orthoses during the rehabilitation of patients with CMC OA, particularly to reduce joint pain and improve hand function. Although there is no conclusive data to support the selection of a specific orthotic design, wearing instructions, and dosage, evidence suggests that the use of short, hand-based orthoses, for at least 2 weeks, improves function and reduces joint pain.

Due to the unique pattern of occupations and activities of daily living performed by patients, clinicians are encouraged to adapt the prescription of orthotic devices according to the demands and challenges presented during the performance of self-care, working, and leisure activities: A short orthosis, fabricated with rigid materials could benefit patients whose primary occupations involve the use of physical strength (i.e. crafting and manufacturing tasks), providing sufficient stabilization of the CMC joint during grasping. However, the same orthosis could compromise a fast-paced task, which does not involve the use of significant hand strength, such as typing on a computer keyboard.²⁴

A thorough evaluation of patients’ occupations, expectations, and aims with the treatment should complement the physical examination performed by clinicians during the selection and prescription of orthotic devices for CMC OA. The use of this approach is related to better functional outcomes and improved adherence of the patient.³⁹

Suggestions for future studies

Currently, no standard procedure regarding orthoses for the patient with CMC OA exists, and although the literature suggests positive effects of orthoses on pain and hand function, no conclusive results can indicate if a particular design is better than others.

Despite an increasing concern of researchers with methodological procedures in studies investigating the influence of orthoses on patients’ functional outcomes, few publications provided an adequate assessment of patients’ satisfaction, comfort, and adherence to the treatment. Besides, data regarding the rationale for the selection of a specific orthotic design, its relation with patients’ or therapeutic goals, costs, and the barriers for orthotic intervention were not described by any of the 14 studies in this scoping review.

Therefore, future studies should aim not only to provide standardized measures of the orthotic intervention outcomes but also to investigate the impact of this therapeutic procedure on the patient’s objectives, adherence, and performance through a more client-centered perspective.

Study limitations

The small number of publications included contrasts with the importance of orthotic interventions during the treatment patients with CMC OA. While the use of orthoses is one of the most common modalities in thumb OA rehabilitation, there are not sufficient investigations to provide conclusive evidence of the efficacy of specific designs.

Notwithstanding the increasing attention of researchers to the influence of socioeconomic barriers and facilitators to rehabilitation interventions, the economic evaluation and comparisons between the costs of orthotic devices could not be assessed in this review.

Although the authors tried to perform a broad literature review, only publications in English were selected for this scoping study. This decision could have excluded relevant studies published in other languages and should be addressed in future research.

Conclusion

The results of this scoping study suggest that the use of orthoses can decrease pain and improve functional performance of patients with osteoarthritis of the CMC joint, with improved functional outcomes obtained through the use of short, hand-based models, providing sufficient joint stability and reducing pain without hindering the mobility of the upper extremity. Despite an increasing number of high-quality studies, the impact of different orthoses on patients’ comfort, treatment adherence, occupations, and activity performance on both short and long terms still need support through adequate evidence.

Footnotes

Author contribution

All authors contributed equally in the preparation of this manuscript.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Conselho Nacional de Desenvolvimento Científico e Tecnológico (10.13039/501100003593 207168/2014-8).

References

Kloppenburg

Hand osteoarthritis-nonpharmacological and pharmacological treatments. Nat Rev Rheumatol 2014; 10: 242–251.

Dahaghin

Bierma-Zeinstra

Ginai

et al . Prevalence and pattern of radiographic hand osteoarthritis and association with pain and disability (the Rotterdam study). Ann Rheum Dis 2005; 64: 682–687.

Spaans

Van Minnen

Kon

et al . Conservative treatment of thumb base osteoarthritis: a systematic review. J Hand Surg Am 2015; 40: 16–21.e1–e6.

Bertozzi

Valdes

Vanti

et al . Investigation of the effect of conservative interventions in thumb carpometacarpal osteoarthritis: systematic review and meta-analysis. Disabil Rehabil 2015; 37: 2025–2043.

Zhang

Doherty

Leeb

et al . EULAR evidence based recommendations for the management of hand osteoarthritis: report of a Task Force of the EULAR Standing Committee for International Clinical Studies Including Therapeutics (ESCISIT). Ann Rheum Dis 2007; 66: 377–388.

Conconi

Halilaj

Parenti Castelli

et al . Is early osteoarthritis associated with differences in joint congruence? J Biomech 2014; 47: 3787–3793.

O’Brien

Giveans

MR.

Effects of a dynamic stability approach in conservative intervention of the carpometacarpal joint of the thumb: a retrospective study. J Hand Ther 2013; 26: 44–52.

Marshall

Van der Windt

Nicholls

et al . Radiographic thumb osteoarthritis: frequency, patterns and associations with pain and clinical assessment findings in a community-dwelling population. Rheumatology 2011; 50: 735–739.

Neumann

Bielefeld

The carpometacarpal joint of the thumb: stability, deformity, and therapeutic intervention. J Orthop Sports Phys Ther 2003; 33: 386–399.

10.

Dieppe

Lohmander

LS.

Pathogenesis and management of pain in osteoarthritis. Lancet 2012; 365: 965–973.

11.

Valdes

Marik

A systematic review of conservative interventions for osteoarthritis of the hand. J Hand Ther 2010; 23: 334–350; quiz 351.

12.

Poole

Pellegrini

Jr.

Arthritis of the thumb basal joint complex. J Hand Ther 2000; 13: 91–107.

13.

Colditz

JC.

The biomechanics of a thumb carpometacarpal immobilization splint: design and fitting. J Hand Ther 2000; 13: 228–235.

14.

Beasley

Osteoarthritis and rheumatoid arthritis: conservative therapeutic management. J Hand Ther 2012; 25: 163–171; quiz 172.

15.

Kjeken

Smedslund

Moe

et al . Systematic review of design and effects of splints and exercise programs in hand osteoarthritis. Arthritis Care Res 2011; 63: 834–848.

16.

Egan

Brousseau

Splinting for osteoarthritis of the carpometacarpal joint: a review of the evidence. Am J Occup Ther 2007; 61: 70–78.

17.

Arksey

O’Malley

Scoping studies: towards a methodological framework. Int J Soc Res Methodol 2005; 8: 19–32.

18.

Sarzi-Puttini

Cimmino

Scarpa

et al . Osteoarthritis: an overview of the disease and its treatment strategies. Semin Arthritis Rheum 2005; 35: 1–10.

19.

Fess

Gettle

Philips

et al . Hand and upper extremity splinting: principles and methods. St. Louis, Missouri: Elsevier Mosby, 2005.

20.

American Society of Hand Therapists A. Splint classification system. Chicago, IL: American Society of Hand Therapists, 1992.

21.

O’Brien

McGaha

JL.

Current practice patterns in conservative thumb CMC joint care: survey results. J Hand Ther 2014; 27: 14–22.

22.

Hermann

Nilsen

Eriksen

et al . Effects of a soft prefabricated thumb orthosis in carpometacarpal osteoarthritis. Scand J Occup Ther 2014; 21: 31–39.

23.

Bani

Arazpour

Hutchins

et al . A custom-made neoprene thumb carpometacarpal orthosis with thermoplastic stabilization: an orthosis that promotes function and improvement in patients with the first carpometacarpal joint osteoarthritis. Prosthet Orthot Int 2014; 38: 79–82.

24.

Maddali-Bongi

Del Rosso

Galluccio

et al . Is an intervention with a custom-made splint and an educational program useful on pain in patients with trapeziometacarpal joint osteoarthritis in a daily clinical setting? Int J Rheum Dis. Epub ahead of print 6 March 2014. DOI: 10.1111/1756-185X.12318.

25.

Bani

Arazpour

Kashani

et al . Comparison of custom-made and prefabricated neoprene splinting in patients with the first carpometacarpal joint osteoarthritis. Disabil Rehabil Assist Technol 2013; 8: 232–237.

26.

Bani

Arazpour

Kashani

et al . The effect of custom-made splints in patients with the first carpometacarpal joint osteoarthritis. Prosthet Orthot Int 2013; 37: 139–144.

27.

Becker

Bot

Curley

et al . A prospective randomized comparison of neoprene vs thermoplast hand-based thumb spica splinting for trapeziometacarpal arthrosis. Osteoarthritis Cartilage 2013; 21: 668–675.

28.

Sillem

Backman

Miller

et al . Comparison of two carpometacarpal stabilizing splints for individuals with thumb osteoarthritis. J Hand Ther 2011; 24: 216–225; quiz 126; discussion 227–230.

29.

Gomes Carreira

Jones

Natour

Assessment of the effectiveness of a functional splint for osteoarthritis of the trapeziometacarpal joint on the dominant hand: a randomized controlled study. J Rehabil Med 2010; 42: 469–474.

30.

Rannou

Dimet

Boutron

et al . Splint for base-of-thumb osteoarthritis: a randomized trial. Ann Intern Med 2009; 150: 661–669.

31.

Boustedt

Nordenskiold

Lundgren Nilsson

Effects of a hand-joint protection programme with an addition of splinting and exercise: one year follow-up. Clin Rheumatol 2009; 28: 793–799.

32.

Wajon

Ada

No difference between two splint and exercise regimens for people with osteoarthritis of the thumb: a randomised controlled trial. Aust J Physiother 2005; 51: 245–249.

33.

Weiss

Lastayo

Mills

et al . Splinting the degenerative basal joint: custom-made or prefabricated neoprene? J Hand Ther 2004; 17: 401–406.

34.

Weiss

LaStayo

Mills

et al . Prospective analysis of splinting the first carpometacarpal joint: an objective, subjective, and radiographic assessment. J Hand Ther 2000; 13: 218–226.

35.

Buurke

Grady

de Vries

et al . Usability of thenar eminence orthoses: report of a comparative study. Clin Rehabil 1999; 13: 288–294.

36.

Frouzakis

Herren

Marks

Evaluation of expectations and expectation fulfillment in patients treated for trapeziometacarpal osteoarthritis. J Hand Surg Am 2015; 40: 483–490.

37.

McKee

Rivard

Orthoses as enablers of occupation: client-centred splinting for better outcomes. Can J Occup Ther 2004; 71: 306–314.

38.

Wajon

Clinical splinting successes: the thumb “strap splint” for dynamic instability of the trapeziometacarpal joint. J Hand Ther 2000; 13: 236–237.

39.

Stukstette

Hoogeboom

de Ruiter

et al . A multidisciplinary and multidimensional intervention for patients with hand osteoarthritis. Clin Rehabil 2012; 26: 99–110.