Trapeziometacarpal Osteoarthritis
Conditions
Keywords
Thumb proprioception, Joint position sense, Pinch aperture proprioception, Trapeziometacarpal joint, Pain, Proprioception, Carpometacarpal, Proprioception*, Thumb*, Carpometacarpal Joints*, Humans
Brief summary
This study looks at people who have osteoarthritis at the base of the thumb. It examines how well the thumb can sense its position and movement. The study has three goals: 1. To compare these measurements between people with thumb base osteoarthritis and healthy people. 2. To find out whether this ability changes from milder to more advanced levels of osteoarthritis. 3. To explore whether this ability is related to factors such as basic personal characteristics, thumb/hand muscle strength and hand use, pain and touch sensation, and emotional factors like fear of movement, anxiety, and depression. This is an observational study. No treatment is given. Participants complete thumb measurements and several tests/questionnaires.
Detailed description
This study aims to quantitatively evaluate thumb proprioception in individuals diagnosed with trapeziometacarpal (TMC) joint osteoarthritis (OA) and to compare the findings with healthy individuals. As a secondary aim, potential determinants that may influence proprioceptive function of the thumb joints will be examined systematically. In this context, relationships between thumb proprioception and participants' demographic characteristics (age, sex, body weight, occupational characteristics, and OA severity), motor functions (muscle strength of opponens pollicis, first dorsal interosseous, abductor pollicis brevis/longus, and flexor pollicis brevis/longus, as well as fine motor performance), sensory functions (pain, light touch/pressure sensation, and vibration sensation), and emotional status (fear of movement, anxiety, and depression) will be investigated. In addition, whether proprioceptive measures differ across radiographic severity levels will be evaluated within the TMC OA group. The study is conducted using a cross-sectional case-control design. Individuals with TMC OA are compared with an healthy control group. In the TMC OA group, disease severity is classified based on radiographs according to the Eaton-Littler classification (Stages 1-4). Thumb proprioception is assessed using two main outcomes: (1) joint position sense (JPS) error values for the TMC, metacarpophalangeal (MCP), and interphalangeal (IP) joints, and (2) pinch aperture proprioception error values. To evaluate the repeatability of pinch aperture proprioception measurement in individuals with TMC OA, an intra-rater test-retest approach is used; the same test is administered to 30 participants by the same assessor within one week. Sample size is planned to support the primary hypothesis. For the primary group comparisons, at least 20 participants per group are targeted. To enable planned subgroup analyses by OA severity, the study aims to include 20 individuals for each Eaton-Littler stage (Stages 1-4) in the TMC OA group (total 80 individuals with TMC OA) and 20 healthy controls, resulting in a total target sample size of 100 participants. Statistical analyses will be performed using SPSS for Windows version 22.0. Continuous variables will be reported as mean ± standard deviation or median (interquartile range), and categorical variables as frequency and percentage. Depending on data distribution, parametric or non-parametric methods will be used. Proprioceptive outcomes will be compared between the TMC OA group and the age-matched healthy control group using appropriate two-group comparison tests. Planned subgroup comparisons across radiographic severity levels (Eaton-Littler Stages 1-4) will be conducted within the TMC OA group. Associations between proprioceptive outcomes and demographic, motor, sensory, and emotional factors will be examined using correlation analyses and, where appropriate, multiple regression models. Statistical significance will be set at two-sided p \< 0.05, and effect sizes will be reported where applicable. Ethics approval was obtained from the Hacettepe University Faculty of Physical Therapy and Rehabilitation Research Ethics Committee (Session date: 23 Oct 2025; Session number: 2025/22; Decision number: FTREK25/112; validity: 23 Oct 2025-23 Oct 2027). All participants received verbal and written information about the purpose and scope of the study, the assessments to be performed, potential discomfort, and their right to withdraw at any time without providing a reason; written informed consent was obtained prior to assessments. A safety approach was adopted such that measurements were discontinued if a participant reported discomfort during assessment. To ensure confidentiality, all participants were assigned a unique study code, and identifying information was stored separately from measurement data. Analyses were conducted using de-identified datasets. Data were stored in password-protected digital files, and any paper forms were kept in a locked cabinet with access restricted to the research team.
Interventions
OTHERThumb Proprioception Assessment
This is an observational study. All participants undergo a standardized thumb proprioception assessment performed by the same assessor. Proprioception is evaluated using (1) joint position sense error at the thumb trapeziometacarpal, metacarpophalangeal, and interphalangeal joints, and (2) pinch aperture proprioception error. No therapeutic intervention is delivered; assessments are for measurement purposes only.
Sponsors
Hacettepe University
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
25 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
(TMC OA group): * Voluntary participation * Radiographic Eaton-Littler stage I-IV confirmed by an orthopedic specialist * Symptom duration ≥6 months * Age 25-75 years * Pain intensity ≥4/10 on the Visual Analog Scale (VAS) during daily activities at assessment * Ability to actively perform ≥40° palmar abduction * Adequate cognitive capacity to understand and perform study procedures (for participants aged ≥65 years: Montreal Cognitive Assessment \[MoCA\] score ≥21) Inclusion Criteria (Control group): * Voluntary participation * No thumb pain * Age 25-75 years * No clinical signs of TMC OA * Negative provocation tests * Adequate cognitive capacity to understand and perform study procedures (for participants aged ≥65 years: MoCA score ≥21)
Exclusion criteria
(TMC OA group): * Inability to abduct the thumb beyond 40° due to severe pain/deformity (especially advanced stage III-IV) * Acute trauma or prior surgery of the hand/wrist * Conservative treatment for hand/thumb pain in the same extremity within the previous 6 months * Current use of anti-inflammatory medication * Peripheral nerve disorders affecting proprioception (e.g., carpal tunnel syndrome, dorsal radial nerve irritation, cervical radiculopathy, double crush syndrome) * Concomitant upper-extremity musculoskeletal disorders (e.g., trigger finger, De Quervain's disease) * Generalized joint hypermobility (Beighton score ≥4) * Neuromuscular, systemic peripheral neuropathic, autoimmune, rheumatic, or infectious diseases * Active malignancy * Neurological conditions affecting pain perception * Visual impairment * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Joint Position Sense (JPS) | Baseline (single assessment at study visit) | Thumb JPS was assessed using a joint position reproduction test at the TMC, metacarpophalangeal (MCP), and interphalangeal (IP) joints using a standard universal goniometer. Target positions were: TMC abduction at 20°, 30°, and 40°, TMC adduction at 20° and 30°; MCP flexion at 20°; and IP flexion at 20°. Each target was tested three times. JPS performance was quantified as the angular error between the target angle and the actively reproduced angle, summarized as the mean error across the three trials (degrees), with higher values indicating poorer proprioception. |
| Pinch Aperture Proprioception | Baseline (single assessment at study visit) | Pinch aperture proprioception was assessed using a pinch aperture reproduction test with a custom-built modified goniometer-based device with reported validity and reliability. The device included circular fingertip pads to standardize thumb-index placement. Two target apertures (15° and 30°) were tested, selected to represent functional pinch apertures for common objects, such as a large medication container (approximately 3.5 cm diameter) and a standard drinking glass (approximately 7 cm diameter), respectively. For each target, three trials were performed, and angular error was computed as the difference between target and actively reproduced aperture; the mean error across trials was used (degrees), with higher values indicating greater impairment. Bidirectional testing (30°→15° and 15°→30°) was performed as described in the protocol. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Joint Mobility | Baseline (single assessment at study visit) | Joint mobility of the thumb was assessed by measuring active range of motion (ROM) of the trapeziometacarpal (TMC), metacarpophalangeal (MCP), and interphalangeal (IP) joints using a standard goniometer. For the TMC joint, abduction, adduction, flexion, extension, and opposition were evaluated. Flexion and extension ROM of the MCP and IP joints were also measured. All joint mobility values were recorded in degrees, with higher values indicating greater joint mobility. |
| Opposition | Baseline (single assessment at study visit) | Thumb opposition was additionally evaluated using the Kapandji opposition score, which grades the maximal opposition achieved by the thumb pulp on a 10-point scale. A score of 1 corresponds to contact with the radial side of the proximal phalanx of the index finger, whereas a score of 10 corresponds to contact with the distal palmar crease of the little finger. |
| Re-Opposition | Baseline (single assessment at study visit) | Thumb re-opposition (reposition ability) was assessed as the minimal contact point reached during return from maximal opposition, recorded using the Kapandji opposition scale (0-10). |
| Hypermobility | Baseline (single assessment at study visit) | Generalized joint hypermobility was assessed using the Beighton Hypermobility Score. This nine-item scoring system evaluates joint laxity at multiple anatomical sites, yielding a total score ranging from 0 to 9. Higher scores indicate greater joint laxity, and individuals with a score of 4 or higher were classified as hypermobile. |
| Thumb/Hand Muscle Strength (Manual Muscle Testing) | Baseline (single assessment at study visit) | Motor function of the thumb and hand was evaluated by assessing manual muscle strength and grip and pinch strength. Manual muscle testing was performed to evaluate the strength of the opponens pollicis, abductor pollicis brevis and longus, first dorsal interosseous, and flexor pollicis brevis and longus muscles. Muscle strength was graded according to the Lovett scale and the Medical Research Council (MRC) classification, with higher scores indicating greater muscle strength. |
| Hand Grip Strength | Baseline (single assessment at study visit) | Hand grip strength will be assessed in the standardized position recommended by the American Society of Hand Therapists: seated, with the arm adducted and in neutral rotation, elbow flexed to 90°, forearm in mid-rotation, and wrist in neutral position. A Jamar hand dynamometer (Jamar; JLW Instruments, Chicago, IL) will be used to measure standard grip strength. The dynamometer handle will be set at the second position, and participants will be instructed to maintain the testing position and squeeze maximally. Three trials will be performed, and the mean value will be recorded in kilograms-force. |
| Lateral Pinch Strength | Baseline (single assessment at study visit) | Lateral pinch strength will be assessed in the standardized position recommended by the American Society of Hand Therapists: seated, with the arm adducted and in neutral rotation, elbow flexed to 90°, forearm in mid-rotation, and wrist in neutral position. A pinch gauge (Pro Med Products, Atlanta, GA) will be used. Participants will be instructed to squeeze the pinch gauge maximally between the thumb pulp and the lateral aspect of the index finger while maintaining the testing position. Three trials will be performed, and the mean value will be recorded in kilograms-force. |
| Tripod Pinch Strength | Baseline (single assessment at study visit) | Tripod pinch strength will be assessed in the standardized position recommended by the American Society of Hand Therapists: seated, with the arm adducted and in neutral rotation, elbow flexed to 90°, forearm in mid-rotation, and wrist in neutral position. A pinch gauge (Pro Med Products, Atlanta, GA) will be used. Participants will be instructed to squeeze the pinch gauge maximally between the thumb, index finger, and middle finger while maintaining the testing position. Three trials will be performed, and the mean value will be recorded in kilograms-force. |
| Tip Pinch Strength | Baseline (single assessment at study visit) | Tip pinch strength will be assessed in the standardized position recommended by the American Society of Hand Therapists: seated, with the arm adducted and in neutral rotation, elbow flexed to 90°, forearm in mid-rotation, and wrist in neutral position. A pinch gauge (Pro Med Products, Atlanta, GA) will be used. Participants will be instructed to squeeze the pinch gauge maximally between the thumb pulp and the index finger pulp while maintaining the testing position. Three trials will be performed, and the mean value will be recorded in kilograms-force. |
| Pain Intensity at Rest (VAS) | Baseline (single assessment at study visit) | Pain intensity at rest was evaluated using the Visual Analog Scale (VAS), scored from 0 (no pain) to 10 (worst imaginable pain), with higher scores representing greater pain intensity. |
| Pain Intensity During Activity (VAS) | Baseline (single assessment at study visit) | Pain intensity during activity was evaluated using the Visual Analog Scale (VAS), scored from 0 (no pain) to 10 (worst imaginable pain), with higher scores representing greater pain intensity. |
| Pain Frequency/Occurrence (Alnot Classification) | Baseline (single assessment at study visit) | Pain frequency and occurrence were classified using the Alnot classification according to the conditions under which pain occurs (0 = no pain, 1 = pain during intense exertion, 2 = pain during daily activities, 3 = spontaneous intermittent pain, 4 = continuous pain). |
| Light Touch/Pressure Sensation (Semmes-Weinstein Monofilament test) | Baseline (single assessment at study visit) | Light touch and pressure sensation were assessed using the Semmes-Weinstein Monofilament (SWM) test (Baseline® Tactile™ Monofilament - 20-piece set). Sensory threshold was determined using graded nylon monofilaments, with a threshold value of 2.83 mg/cm² considered normal. Perception of monofilaments greater than 2.83 in any of the first three digits was interpreted as sensory impairment. Sensory performance was recorded based on the smallest monofilament perceived, with higher values indicating reduced cutaneous sensitivity. |
| Vibration Sense (128 Hz tuning fork) | Baseline (single assessment at study visit) | Vibration sense was evaluated using a 128 Hz tuning fork applied to the radial styloid. The duration of perceived vibration was recorded in seconds, and values of 8 seconds or less were considered indicative of impaired vibration sense. Longer perception times reflected better vibration sensitivity. |
| Hand Grip-Related Functional Performance Score (5 Grasp Patterns) | Baseline (single assessment at study visit) | Grip function was assessed across five commonly described grasp patterns in daily activities: power grip, key pinch, pinch grip, cylindrical grip, and precision grip. Functional difficulty for each grasp type was rated using a three-level Likert-type scale, with scores of 4 indicating no or mild difficulty, 2 indicating moderate difficulty, and 0 indicating severe difficulty or inability to perform the task. The total score ranged from 0 to 20, with lower scores reflecting poorer hand function. Individuals with a total score of 16 or less were classified as having moderate to poor hand function, defined by the inability to perform at least one grasp type and difficulty in at least two grasp patterns. |
| Manual Dexterity and Functional Sensory Performance (Moberg Pick-Up Test) | Baseline (single assessment at study visit) | Functional sensory performance and manual dexterity were assessed using the Moberg Pick-Up Test. The test evaluates the ability to manipulate small objects using tactile input and fine motor control. Performance was quantified as the time required to complete the task, recorded in seconds. Mean completion time across repeated trials was used for analysis, with longer times indicating reduced functional performance. |
| Thumb-Specific Disability (Thumb Disability Index [TDX]) | Baseline (single assessment at study visit) | Thumb-specific functional disability was assessed using the Thumb Disability Index (TDX), a patient-reported outcome measure consisting of 20 items across three domains: thumb-related functional activities, pain, and satisfaction with the affected thumb. Total and subscale scores were calculated and transformed to a 0-100 scale, where higher scores indicate greater functional limitation. TDX scores were not calculated when more than 10% of items were left unanswered. |
| Upper Extremity Disability (QuickDASH) | Baseline (single assessment at study visit) | Overall upper extremity function was evaluated using the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire. This 11-item self-reported measure assesses symptoms and functional limitations related to upper extremity use. Total scores range from 0 to 100, with higher scores indicating greater disability. The Turkish version of the QuickDASH has demonstrated established validity and reliability. |
| Emotional Distress (Hospital Anxiety and Depression Scale [HADS]) | Baseline (single assessment at study visit) | Emotional status was assessed using the Hospital Anxiety and Depression Scale (HADS). The HADS is a 14-item self-report questionnaire consisting of two subscales that assess symptoms of anxiety (7 items) and depression (7 items). Each item is scored on a 4-point Likert scale ranging from 0 to 3, yielding subscale scores between 0 and 21. Higher scores indicate greater emotional distress. Scores of 0-7 are considered within the normal range, scores of 8-10 indicate possible emotional disturbance, and scores of 11 or higher suggest clinically relevant anxiety or depression. The HADS is intended as a screening tool rather than a diagnostic instrument and reflects emotional status over the previous week. |
| Fear of Movement (Tampa Scale of Kinesiophobia [TSK]) | Baseline (single assessment at study visit) | Fear of movement was evaluated using the Tampa Scale of Kinesiophobia (TSK). The TSK is a 17-item Likert-type questionnaire designed to assess fear of movement and re-injury associated with pain. Each item is scored from 1 (strongly disagree) to 4 (strongly agree), resulting in a total score ranging from 17 to 68. Four items are reverse scored, and higher total scores indicate greater levels of kinesiophobia. A total score above 37 is commonly used to indicate a high level of fear of movement. The Turkish version of the TSK has demonstrated acceptable validity and test-retest reliability. |
| Passive Positional Stability of Thumb Joints During Pinch (No Load) | Baseline (single assessment at study visit) | Thumb joint positional awareness during pinch will be assessed in a quiet room under a passive (no-load) condition. The trapeziometacarpal (TMC), metacarpophalangeal (MCP), and interphalangeal (IP) joints will be evaluated. The examiner passively sets Kapandji position 3 (TMC and MCP 30° flexion; IP 20°), participants encode the position for approximately 30 seconds, and then reproduce the posture with eyes closed. Joint angles are measured with a manual goniometer (degrees). A practice trial precedes testing; each measure is taken 3 times and averaged, with 2-minute rest between trials. |
| Active Load-Bearing Positional Stability of Thumb Joints During Pinch | Baseline (single assessment at study visit) | Thumb joint positional awareness during pinch will be assessed in a quiet room under an active load-bearing condition. The trapeziometacarpal (TMC), metacarpophalangeal (MCP), and interphalangeal (IP) joints will be evaluated. The same target posture (Kapandji position 3: TMC and MCP 30° flexion; IP 20°) is set and encoded, then reproduced with eyes closed during maximal voluntary pinch on a pinch dynamometer. Joint angles are measured with a manual goniometer (degrees). A practice trial precedes testing; each measure is taken 3 times and averaged, with 2-minute rest between trials. |
Countries
Turkey (Türkiye)
Contacts
CONTACTMerve Sümeyye Yılmaz, PT
CONTACTÇiğdem Ayhan Kuru, PT, PhD
PRINCIPAL_INVESTIGATORÇiğdem Ayhan Kuru, PT, PhD
Faculty of Physiotherapy and Rehabilitation, Department of Orthopedic Physiotherapy and Rehabilitation, Hacettepe University, Ankara, Turkey
STUDY_DIRECTORMerve Sümeyye Yılmaz, PT
Faculty of Physiotherapy and Rehabilitation, Department of Orthopedic Physiotherapy and Rehabilitation, Hacettepe University, Ankara, Turkey
Outcome results
None listed