Assessment of Wrist Malalignment in Juvenile Rheumatoid Arthritis

Progressive Distal Radius Deformity in Juvenile Idiopathic Arthritis: A Case Report

CASE

We report a case of progressive angular deformity of the left wrist in a 4-year-old girl with a 2-year history of juvenile idiopathic arthritis (JIA)-oligoarthritis subtype (<4 joints affected) with inflammatory extensor tenosynovitis affecting the left wrist, who underwent a left distal radius osteotomy with tricortical allograft for angular correction and functional recovery. Six years postoperatively, the patient demonstrates a near-anatomic left wrist and has recovered full range of motion and function.

CONCLUSION

This case demonstrates how rare clinically devastating angular deformities in JIA may safely and effectively be surgically managed to promote normal, long-term, extremity function.

Force transmission through the juvenile idiopathic arthritic wrist: a novel approach using a sliding rigid body spring model

Force transmission across the wrist during a grasping maneuver of the hand was simulated for three children with juvenile idiopathic arthritis (JIA) and for one healthy age-matched child. Joint reaction forces were estimated using a series of springs between articulating bones. This method (i.e., rigid body spring modeling) has proven useful for examining loading profiles for normally aligned wrists. A novel method (i.e., sliding rigid body spring modeling) designed specifically for studying joint reaction forces of the malaligned JIA wrist is presented in this paper. Loading profiles across the wrist for the unimpaired child were similar using both spring modeling methods. However, the traditional fixed-end method failed to converge to a solution for one of the JIA subjects indicating the sliding model may be more suitable for investigating loading profiles of the malaligned wrist. The results of this study suggest that a larger proportion of force is transferred through the ulno-carpal joint of the JIA wrist than for healthy subjects, with a less than normal proportion of force transferred through the radio-carpal joint. In addition, the ulnar directed forces along the shear axis defined in this study were greater for all three JIA children compared to values for the healthy child. These observations are what were hypothesized for an individual with JIA of the wrist.

Displacement response of juvenile arthritic wrists during grasp

OBJECTIVE

To analyze the displacement response of juvenile arthritic wrists during grasp in order to diagnose early ligamental laxity and facilitate early splinting.

METHODS

X-rays of the wrists, made under standardized conditions, of 30 children with juvenile chronic arthritis (mean age 10.4 years, range 4.5-16.9) were analyzed after being digitalized. Osseous landmarks were identified, and coordinates were calculated from measured angles and lengths with an accuracy of 0.01'. Lunate and carpal-ulnar distance were obtained according to Youm, and ulnar variance according to Häfner.

RESULTS

Overall, an increase in ulnar-lunate displacement and carpal narrowing and a decrease in ulnar variance were found. However, not all wrists responded to the same extent. Radial displacement of the lunate, though slight, was found in 2 wrists and the amount of ulnar displacement varied substantially (3.1% to 22.5%). The variance in amount of displacement could suggest that juvenile wrists do not respond to increased compressive forces to the same extent.

CONCLUSION

The changes found are similar to those found in the healthy wrist. Furthermore, our findings suggest that the juvenile wrist acts in accordance with the generally accepted explanation for the development of malalignment in adult wrists. It seems that laxity of ligaments can be diagnosed early by the force grip maneuver during x-ray. It would have a significant impact on the moment of orthotic intervention as well as the design of the orthotic device. Further study along this line seems justified.