Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
Surgery for osteoarthritis of the thumb joint, such as trapeziecotmy (removal of a small bone in the wrist at the base of the thumb), leads to good results and high patient satisfaction. However, in some cases, repeated surgery is required due to persistent pain and restricted hand function. We aim to study the outcomes of this repeated surgery and to analyse the reasons for this surgery.

Who can participate?
All patients, who had a revision surgery at our center in the last 10 years will be invited for a follow-up consultation consisting of a clinical examination, radiographs and a questionnaire.

What does the study involve?
All patients who had a revision surgery of the CMC I joint between April 2009 and at least one year prior to examination will be eligible for participation and will be invited to a follow-up consultation. This consultation consists of a clinical examination, radiographs and a patient questionnaire.

What are the possible benefits and risks of participating?
Benefits: There is no compensation for participation. The increased scientific knowledge generated by this project will be primarily a gain for other patients seeking treatment for the same condition and will assist the surgeon in the decision-making process prior to surgery_
Risks: As patients will be invited for a follow-up examination, there is no intervention. The clinical examination and the completion of a patient subjective outcome questionnaire represent no more than minimum risk for project participants. At the follow-up examination, three radiographs of the thumb will be taken which are associated with low level of radiation of about 0.001 mSv (comparable to normal background radiation from less than a day according to

Where is the study run from?
Schulthess Klinik, Zurich, Switzerland.

When is the study starting and how long is it expected to run for?
June 2019 to October 2019

Who is funding the study?
Schulthess Klinik, Zurich, Switzerland.

Who is the main contact?
Dr Miriam Marks,

Trial website

Contact information



Primary contact

Dr Miriam Marks


Contact details

Lengghalde 2

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

Outcomes of revision of thumb carpometacarpal joint (CMC I) arthroplasty


Study hypothesis

Patients after CMC I revision surgery are in an acceptable pain state shown by a NRS score of ≤ 2.5 during daily activities.

Ethics approval

Approved 13/05/2019, Kantonale Ethikkommission Zürich (Cantonal ethics committee Zurich, Stampfenbachstrasse 121, 8090, Zürich, Switzerland; +41 (0) 43 259 79 70;, ref: 2019-00569

Study design

Ambidirectional monocenter research project consisting of a retrospective chart review and a prospective case series

Primary study design


Secondary study design

Case series

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Osteoarthritis of the CMC I joint


This study solely consists of one consultation with a duration of approx. 45 min. After the patient provided written informed consent, the patient will undergo a clinical examination including radiographs. The clinical examination includes measures of range of motion (ROM), grip and pinch strength and radiographs. Afterwards, the patient will complete a questionnaire on a tablet PC, which data will be stored in a REDCap database. All data from the clinical measures will be entered directly into the REDCap project database by the doctor.

Intervention type



Drug names

Primary outcome measure

Level of pain. If patients are in a Patient Acceptable Symptom State (PASS) regarding pain during activities measured on a Numeric Rating Scale (NRS; 0 = no pain, 10 = worst pain). The PASS is defined as an NRS score of ≤ 2.5.

Secondary outcome measures

1. Range of Motion measured using flexion and extension of the MCP and thumb Interphalangeal (IP) joint will be measured with a goniometer. The evaluation of active thumb opposition is based on the Kapandji index, ranging from 1 to 1026. Patients try to touch their fingers with the tip of the thumb. The score is 1 when patients are able to touch only the lateral side of the index finger and 10 when they can reach the volar crease of the hand.
2. Grip strength measured using a JAMAR dynamometer.
3. Key pinch measured using a pinch gauge.
4. Radiographs. If radiographs of before primary surgery are available, OA severity will be graded from stage I (normal articular contours with joint widening due to ligament laxity) to stage IV (complete thumb CMC joint deterioration and narrowed, sclerotic scaphotrapezial joint) based on the Eaton classification. At follow-up, three radiographic views of the affected hand (anterior-posterior, lateral and oblique) to assess the trapezial space ratio will be taken and the trapezial space ratio will be calculated.
5. Hand function measured using the Brief Michigan Hand Outcomes Questionnaire (MHQ).
6. Satisfaction measured using two additional questions about satisfaction in the consultation.
7. Sociodemographic and disease-related data which will be extracted from the medical records: Age, gender, diagnosis, date and type of primary and revision surgery/surgeries, indication for primary and revision surgery/surgeries, affected side, date of diagnosis, complications after primary and revision surgery/surgeries, other surgeries performed in the same session (e.g. carpal tunnel release), clinical data (range of motion, strength).
8. Adverse events that had been occurred during or after primary and revision surgery will be extracted out of the medical records and patients will be asked about additional events not documented in the medical records.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patient with any type of revision surgery at the CMC I join
2. Revision surgery between 1 and 10 years before the follow-up examination
3. Primary surgery consisted of any type of resection arthroplasty or implant arthroplasty
4. Informed consent as documented by signature

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Major surgery at another joint at the same hand (e.g. PIP arthroplasty, DIP arthrodesis) less than 6 months before the examination
2. Legal incompetence
3. Cannot read or write German language to complete the questionnaires

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Schulthess Klinik
Lengghalde 2

Sponsor information


Schulthess Klinik

Sponsor details

Lengghalde 2
+41 44 385 75 81

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

Schulthess Klinik

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Abstracts for SGH ans FESSH conferences 2020
Full paper will be submitted to JHS Eur in 2020

IPD sharing statement:
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

23/05/2019: Trial’s existence confirmed by Kantonale Ethikkommission Zürich (Cantonal ethics committee Zurich).