Risk factors for rupture of extensor tendons in the rheumatoid wrist

Radiographic study of the distal ulna in rheumatoid arthritis with extensor digitorum communis ruptures

OBJECTIVES

Extensor digitorum communis (EDC) rupture of the wrist often occurs in patients with rheumatoid arthritis (RA). Early operation is desirable for patients with a high risk of rupture; therefore, rheumatologists should diagnose it during daily examinations. This study aimed to clarify radiographic changes in the distal ulna and related factors associated with EDC rupture in patients with RA.

METHODS

We analysed plain radiographs of 40 patients with RA associated with EDC rupture and 62 healthy controls. We investigated the deformation of the distal ulna, Larsen grades, and radiological parameters such as ulnar variance (UV), ulnar bowing angle, dorsal protrusion (DP), and dorsal bowing angle.

RESULTS

The ratios of the ulna head deformation, Larsen grades, UV, DP, and dorsal bowing angle were significantly larger in the ruptured group than in the control group. Multiple logistic regression analysis revealed that DP and Larsen grades were significantly associated with EDC rupture.

CONCLUSIONS

Deformity of the distal ulna is evident in patients with an EDC rupture. Ulnar head deformation, high Larsen grades, and large DP are the potential risk factors for EDC rupture.

Radiographic changes in the distal ulna in non-rheumatoid patients with extensor digitorum communis ruptures

INTRODUCTION

Osteoarthritis of the distal radioulnar joint (DRUJ) is relatively common in elderly people. Extensor digitorum communis (EDC) ruptures occasionally and occurs with or without prior signs in these people. The purpose of this study was to clarify the radiographic changes in the distal ulna associated with EDC rupture.

MATERIALS AND METHODS

We analyzed plain radiographs of 71 patients with non-rheumatoid arthritis and 40 controls. Radiographic changes in the distal ulna were categorized into normal, osteoarthritic-change (OA-change), and taper. We measured the ulnar variance (UV) and ulnar bowing angle in the posteroanterior radiographs and the dorsal bowing angle (DBA) and dorsal protrusion (DP) in the lateral radiographs. The shape of the sigmoid notch (SN) was categorized into flat, radial inclination, and dimple. The primary outcome was a comparison of radiographic parameters between the patient and the control groups. The secondary outcome was an analysis of the type of SN to investigate factors affecting ulnar deformation.

RESULTS

The ratio of the radiographic change in the ulna, UV, DBA, and DP was significantly larger in the patient group than in the control group. Patients with the radial inclination type of SN showed a greater UV than those with the dimple type.

CONCLUSIONS

Deformation of the distal ulna, a large UV, dorsal penetration, and dorsal bowing was related to EDC rupture. Regarding the large UV, the lunate shaved the upper half of the distal ulna, whereas the DRUJ shaved the lower half. These processes formed a tapered ulna head. A large UV and an inclination of the DRUJ played a role in ulnar head deformation.

Rheumatoid Hand Surgery in the Era of Biologic Therapy: A Rheumatologist-oriented Overview

Rheumatoid arthritis (RA) can cause significant hand and wrist damage and dysfunction. The aim of medical treatment is to eradicate inflammation and prevent damage to joints and soft tissues. Advances in newer biological therapies over the last two decades have resulted in greater remission rates and lower disease activity status. Despite these improvements, surgical intervention is still indicated in cases of disability, irreversible deformities, and severe pain. However, there are large variations in the surgical rates of common rheumatoid hand procedures, which may indicate clinical uncertainty or disagreement between treating rheumatologists and hand surgeons. In this review, we provide a basic overview of common problems of the hand and wrist in RA patients. The target audience is rheumatologists for their better understanding of surgical options and for better informed patient consultation before referring to hand surgeons.