The Wrist Joint Affected by Rheumatoid Arthritis - Computational Biomechanics of the Wrist Joint - page 28

Table 3.1 Radiographic staging according to Larsen-Daale-Eek [ 12 , 14 ]
Larsen score Radiographic changes

0 Normal joint, no changes

1 Osteoporosis and swelling

2 Joint space narrowing and erosion

3 Significant erosion, moderate destruction

Table 3.2 Wrightington classification [ 13 , 15 ]

Score Radiographic finding Therapy

1 Osteoporosis, cysts, erosion Synovectomy

2 Carpal Instability Soft tissue stabilization/partial arthrodesis

3 Destruction, subluxation Arthroplasty/arthrodesis

4 Severe radial destruction Arthrodesis

Table 3.3 Simmen and Hubber classification [ 12 , 16 ]

Type Natural course of the disease

I Also known as ankylosing type, where spontaneous fusion of the wrist as the indicator

II It comes together with arthritic and degenerative changes. This also known as

osteoarthritic type showing both the osteoporosis as well as subchondral sclerosis
which affects stabilization

III The wrist with progressive disintegration and instability (luxation, progredient bone loss

and mutilation) can be categorized under this disintegrative type. There are two
subtypes:
IIIa with more ligamentous instability
IIIb with complete loss of carpal anatomy due to marked destruction of the bone

To efficiently examine the severity of the RA deformities, previous reports have
introduced several classifications according to their own reliable approaches.
Larsen et al. classification used radiologic changes for scoring system with the
basis of 5 grades, in which the degree of joint and cartilage destructions used as the
primary indicators (Table 3.1 )[ 12 , 14 ]. Combination between radiologic findings
and therapeutic options were used in the Wrightington classification, with the basis
up to four grades (Table 3.2 )[ 13 , 15 ]. Simmen and Huber on the contrary
established a classification method purely based on the natural course of the dis-
ease, without considering any radiologic inflammatory destruction [ 12 , 16 ]. This
classification

distinguished the courses into three types. Table 3.3 provides

information on these three classifications of RA.
There are three main characteristics of the wrist affected by RA: cartilage
destruction, synovial proliferation and ligamentous laxity [ 10 , 17 ]. Cartilage
destruction of thinning was occurred due to cytochemical action, which resulting
in degradation of existing cartilages and inhibition of new cartilage formation [ 17 ].
The synovial proliferation may cause bone erosion with sharp edges which might
lead to tendon rupture [ 10 , 18 ]. Ligamentous laxity caused by stretching attributed