Rhizarthrosis is the second most common degenerative disease of the hand after osteoarthritis of the distal interphalangeal joints [1, 2]. It affects women 10 to 15 times more often than men, especially from the age of 50 [3, 4, 5]. In 20-30% of cases, both hands are affected [3].
In the development of idiopathic rhizarthrosis, rotational forces with eccentric loading of marginal areas and consequently locally high pressure peaks during the opposition movement in the thumb saddle joint (TSJ) may play a role [4, 6]. Other possible influencing factors include a mismatch of the joint surfaces between the trapezium bone and the base of the first metacarpal or a deformity of the trapezium bone with steep positioning of the joint surface [3, 4]. The most significant cause of rhizarthrosis is considered to be ligament instabilities, which are either trauma-induced or result from prolonged overuse of the joint or are a consequence of general ligament laxity. Ligament instabilities of the TSJ lead to dorsoradial translation of the MHK-I base with focal overloading of the joint surfaces during a strong pinch grip [7]. Secondary rhizarthroses due to trauma (e.g., MHK-I base fracture) or rheumatic or septic arthritis are less common [3, 4].
To confirm the diagnosis, classify the disease stage, and plan therapy, conventional X-rays of the thumb in two planes are required. The radiological findings allow for the staging according to Eaton and Littler [8].
Radiological classification of rhizarthrosis according to Eaton and Littler
Stage I | Normal, possibly widened joint space (effusion), slight subluxation of the first metacarpal bone |
Stage II | Slight narrowing of the joint space, osteophytes smaller than 2 mm, significant subluxation of the first metacarpal bone |
Stage III | Significant narrowing of the joint space up to obliteration of the joint space, osteophytes larger than 2 mm |
Stage IV | Joint destruction, cystic, sclerotic remodeling processes, pronounced subluxation of the first metacarpal bone, STT arthritis |
(STT joint = scapho-trapezo-trapezoidal joint)
Since the radiological severity of rhizarthrosis does not necessarily correlate with the clinical symptomatology, but the subjective degree of pain expression is crucial for therapy planning, the clinical symptomatology should be recorded with the staging according to Alnot and Saint Laurent [9].
Staging of rhizarthrosis according to clinical pain symptomatology by Alnot and Saint Laurent
Stage 0 | No symptoms |
Stage I | Pain during specific activities |
Stage II | Pain during daily activities |
Stage III | In addition to Stage II, episodes of resting pain |
Stage IV | (Almost) constant pain |
The goal of conservative treatment of rhizarthrosis is pain relief, including inhibition of the local inflammatory reaction:
- Temporary use of NSAIDs
- Intra-articular injections of corticosteroids, hyaluron [10, 12-14]
- Radiosynoviorthesis [15]
- Orthosis for a maximum of 2 weeks [16]
The surgical therapy of rhizarthrosis is performed according to the stage classification by Eaton and Littler. A distinction is made between joint-preserving and joint-resecting procedures.
Joint-preserving procedures:
- Ligamentoplasties
- Arthroscopy
- Denervation
- Extension osteotomy
Joint-resecting procedures, elimination of the opposition movement in the TSJ:
- Endoprosthetic replacement of the TSJ
- Arthrodesis of the TSJ
- Resection arthroplasty
Resection arthroplasty
Due to its high success and low complication rate, resection arthroplasty (RSA) is considered the gold standard of surgical treatment for advanced rhizarthrosis in stages III and IV according to Eaton and Littler [3, 4, 17]. The principle of RSA is based on the removal of the arthritic joint by resecting the trapezium bone. There are numerous technical variants for the subsequent stabilization of the thumb column.
The first trapeziectomy was described by Gervis in 1949, who performed a capsular suture proximal to the MHK-I base to stabilize the thumb column [18]. The formation of stable scar tissue was intended to prevent painful proximalization of the thumb column.
To support the thumb column, interposition plasties were later developed, in which autologous material is introduced into the trapezium cavity, such as a rolled, distally pedicled FCR tendon strip or a tendon bundle formed from a free palmaris longus tendon graft [19].
Stabilization of the thumb column in suspension arthroplasties is achieved through direct or indirect reconstruction of the intermetacarpal ligaments between the MHK-I and MHK-II bases. Tendon strips from the FCR, APL, or ECRL tendons are used in variable techniques for this purpose.
In resection-suspension arthroplasty according to Epping, after complete trapeziectomy, a distally pedicled strip from the FCR plastic is prepared, passed through a drill hole in the MHK-I base, and blocked in the drill hole with a bone wedge from the resected trapezium bone according to the original technique described in 1983 [20].
The suspension can be extended by an additional interposition plasty of the overlong prepared FCR tendon (technique according to Burton and Pellegrini or ligament-reconstruction-tendon-interposition [LRTI] arthroplasty). Here, the remaining tendon strip is sewn into a bundle and fixed with sutures for interposition in the former trapezium cavity [21]. Resection-suspension-interposition arthroplasty is the most commonly used technique for surgical treatment of rhizarthrosis in the USA and Europe [22, 23].
In follow-up studies, high patient satisfaction of around 90% was observed long-term, independent of the technique of suspension and interposition, with very good, mostly free mobility of the thumb as well as normalization of gross strength and improvement of pinch and key grip strength. In 80% of cases, patients were symptom-free, and in 90% at least significantly symptom-reduced. Furthermore, a low complication rate of about 1-5% was observed [4, 24-27]. However, a long rehabilitation phase, sometimes up to 6 months, is to be expected after RSA [4, 24].
In a prospective randomized study, no difference in subjective and functional outcomes was observed 1 year after surgery between patients who received a pure trapeziectomy, patients with trapezium resection and palmaris longus tendon interposition, and patients with trapeziectomy and subsequent suspension and interposition arthroplasty (ligament-reconstruction-tendon-interposition [LRTI] arthroplasty). However, patients with tendon interposition or suspension-interposition arthroplasty had a significantly increased complication rate [25].
In a Cochrane Review from 2015, 11 studies with a total of 670 patients were included.
No difference was found between the surgical treatment alternatives with pure trapeziectomy, trapeziectomy with suspension and/or interposition arthroplasty, spacer insertion, and TSJ arthrodesis in terms of patient satisfaction, pain, functional outcome, quality of life, and complication rate [28].