OBJECTIVE CLINICAL PARAMETERS AND PATIENT-RATED WRIST FUNCTION

Abstract

Patient disability and handicap following wrist injuries have been the focus of recent research interest¹. However, the relative importance of each of the commonly-reported and easily-measured clinical outcome parameters such as the range of wrist movement and the grip strength on the level of actual wrist disability following distal radial fractures has not been investigated previously. The present study investigates the correlation between measurements of specific clinical parameters and the patient-rated wrist joint function following wrist fractures.

A prospective assessment of unstable (AO types 23-A2, -A3, -C1 and -C2) fractures of the distal radius treated by closed reduction and percutaneous K-wire fixation followed by cast immobilisation was undertaken. One hundred consecutive observations were made during various follow-up time periods up to one year in a group of twenty-five patients (fifteen female and ten male patients, mean age 43 years – range 18 to 67 years). The clinical parameters tested were the range of wrist dorsiflexion, palmarflexion, pronation and supination (measured using a goniometer) and the mass grip strength (Jamar grip dynamometer) following removal of the plaster cast, expressed as percentage of the affected side relative to the opposite normal side. Additionally, each patient completed the Patient-Rated Wrist Evaluation (PRWE) Score¹. A stepwise multiple regression multivariate model was employed to statistically analyse the relative effect (expressed as the regression coefficient, b) of each clinical parameter on the ‘Function Score’ part of the PRWE Score. Furthermore, the association between each clinical parameter and the Function Score part of the PRWE Score was also investigated using single-patient observations by calculating the correlation coefficient (r).

The results of the statistical analysis (Minitab 12.1) gave the following regression (b) and correlation (r) coefficient values: grip strength (b=0.77, r=0.80), dorsiflexion (b=0.58,r=0.78),pronation (b=0.39,r=0.70),supination (b=0.38, r=0.63), palmarflexion (b=0.32, r=0.62).

The present study shows that grip strength (expressed as percentage that of the unaffected side) is the most reliable index of wrist disability and the most sensitive indicator of return of wrist function, followed by the range of wrist dorsiflexion and pronation. Wrist supination and palmarflexion are the clinical outcome variables showing the weakest correlation with the wrist function as rated by the patients. These observations may facilitate correct interpretation and comparisons of the results of clinical studies on various methods of treatment of wrist trauma.