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Classification according to ICD-10
M18 Rhizarthrosis (arthrosis of the thumb saddle joint)
ICD-10 online (WHO version 2019)

The rhizarthrosis (from Greek ῥίζα rhiza "root" and ἄρθρον Arthron "joint") is an arthrosis of the first carpometacarpal joint . After Heberden's osteoarthritis, it is the most common degenerative disease in the hand. Women are affected more often than men. The causes are improper or excessive stress, and in women there may also be postmenopausal hormone changes that impair joint stability through loosening of the ligaments.


The diagnosis is confirmed by an X-ray . However, the radiological extent of a saddle joint arthrosis does not provide any information about the pain intensity that a patient feels. There are patients with advanced x-ray symptoms who do not feel any significant pain and vice versa.


Conservative therapy

First, conservative therapy is used, and surgical interventions are only carried out in rare cases, as there is no procedure with consistently good and long-lasting results.

Conservative therapy aims to treat the inflammation responsible for the pain. This is usually done by rest, cooling and ingestion or local application of an anti-inflammatory drug such as z. B. ibuprofen or diclofenac . The thumb and thumb joints can be immobilized using special wrist splints ( orthoses ) that enclose the thumb saddle joint. z. B. Rhizarthrosis Extension Orthosis.

Conservative therapy also includes the occasional injection of a cortisone preparation into the joint in the case of acute inflammation or the injection of hyaluronic acid to improve the gliding ability of the joint, as well as special physiotherapy exercises. Radiation may also improve symptoms over the long term.

The leech therapy is another treatment option in the field of natural medicine, their value is scientifically not sufficiently evaluated.

Operational procedures

When it comes to surgical procedures, there are numerous surgical techniques that can be classified into several groups:

Saddle joint arthroplasty

The principle of saddle joint arthroplasty is that one of the two bones involved in the damaged joint, the large polygonal bone, is removed (trapezectomy). This can result in the thumb becoming slightly shorter due to the lack of support for the first metacarpal bone. In order to keep this effect as low as possible, numerous surgical modifications were developed to "hang" the first metacarpal bone on neighboring bones and thus prevent it from slipping. Tendons from the immediate vicinity of the diseased joint are usually used for this purpose. These are methods that have been tried and tested for decades and have a high success rate. However, the relatively long postoperative healing process of around three to six months and a certain remaining decrease in thumb strength should be mentioned as disadvantages of this method. The mobility is initially limited. After the operation, a so-called cast splint is worn for about 6 to 10 weeks. Mobility can be restored with occupational therapy and physiotherapy.

Arthroplasty with cartilage transplant

Another option for arthroplasty is the replacement of the large polygonal bone with the body's own cartilage, which is removed from the ribs. As a result, the length of the thumb and thus also the force can largely be retained.

Severing nerves to avoid pain

By selectively severing the nerve branches that transmit the pain perception of the thumb saddle joint, pain reduction or freedom from pain can be achieved.

Supply with endoprostheses

Endoprostheses of the thumb saddle joints with loosening and dislocation of the prosthetic socket in the left trapezoidal bone

The first endoprostheses were made of silicone and were first described by Swanson in 1969 for finger joints and the thumb saddle joint. However, they led to foreign body granulomas (" siliconitis ") and could break and loosen so that they can no longer be used. The first cemented metal prosthesis with a socket and a round head was presented by de la Caffinière in 1979, but it also showed high rates of loosening and is now only used in older patients with low mechanical demands on the thumb saddle joint.

With the Ledoux prosthesis, the first uncemented prosthesis was presented in 1990, which, however, is no longer available due to poor results. As a result, however, several new uncemented prostheses have been introduced to the market since the 1990s, such as: B. the prosthesis types Arpe, Elektra, Maia, Roseland or Ivory. They are all made of metal with a socket anchored in the trapezoidal bone and a polyethylene inlay, as well as with a shaft in the first metacarpal bone on which a joint ball sits (either fixed or modular). The metal shaft is partially coated with hydroxyapatite . In addition to uncoupled prostheses, there are also coupled prostheses in which the head and socket are firmly connected in an articulated manner.

Due to the new development, survival rates for the first five years are only available for very few prostheses . Two studies show a survival rate of 85% and 97% after five years for the Arpe prosthesis. For the Elektra prosthesis, a study shows a revision rate of 44% after six years. The main problem is still aseptic loosening of the prosthesis, especially of the joint socket (as in the X-ray image on the left thumb), which occurs significantly more frequently the longer it has been since the operation.

Individual evidence

  1. Christian Karl Spies, Martin Langer, Peter Hahn, Lars Peter Müller, Frank Unglaub: Therapy of primary finger and thumb joint arthrosis. In: Deutsches Ärzteblatt. Volume 115, No. 16, 2018, pp. 269–275 doi: 10.3238 / arztebl.2018.0269 .
  2. Note on the website of the Hümmling Hospital Sögel, pdf ( Memento of the original from May 1, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.xn--hmmling-hospital-sgel-yec4j.de
  3. ^ Wannenmacher, Michael 1938-2015: Radiotherapy . Ed .: Wannemacher, Wenz, Debus. 2., revised. Springer, Berlin 2013, ISBN 978-3-540-88304-3 , pp. 1010 .
  4. Sam Vander Eecken, Wim Vanhove, Nadine Hollevoet: Trapeziometacarpal joint replacement with the Arpe prosthesis Acta Orthopædica Belgica 2012, Volume 78, Edition 6, pages 724-729