Hypothesis: Bayne-Klug classification for Radial Club Hands is based on skeletal defects. Hand quality and functional capacity differ considerably inside Bayne-Klug types III and IV. A detailed Severity Grading is the key for proper evaluation of radial longitudinal deficiency (RLD). Methods: Systematic preoperative assessment was used in a series of 44 radial club hands in 32 patients. There were 34 Bayne-Klug type IV hands, 7 Bayne-Klug type III hands, and 3 Bayne-Klug type II hands, according to x-ray findings. Analysis of the function of fingers, hand, wrist, elbow, and shoulder was done. A chart was filled assuming that severity of different findings is negatively related to hand quality and to overall functional capacity. Presented Severity Grading gives 10 severity points for Hand quality (H), 10 points for Wrist tightness (W), and 10 points for Proximal functional defects (P). Combined severity scores, named as Severity Index for Radial Club Hand, are comparable when using the sum of Hand and Wrist scoring and adding the value of proximal lesions separately. Results: Radial Club Hands could be scored into three groups: (1) Mild: H + W + P gave 4 to 8 severity points (in mean, 5.8). There were 8 (18%) radial club hand (RCH) extremities. Proximal (P points in mean, 1.1) lesions were very rare in these extremities. (2) Moderate: H + W + P gave 9 to 16 severity points (in mean, 11.5). There were 21 (48%) RCH extremities. Mild proximal (P points in mean, 2.2) lesions were found. (3) Severe: H + W + P gave 17 to 30 severity points (in mean, 21.1). This group had 15 (34%) RCH extremities. Proximal (P points in mean, 5.4) lesions were found in all extremities. In repeated x-ray studies, a weakness in Bayne-Klug classification was noticed as the type IV will change during the growth very often into type III. In our series, the change due to ossification of the early invisible proximal radius occurred in 41% of forearms in the group of 19 patients followed over 11 years. Summary Points: Severity Index, a sum of severity points for Hand quality, Wrist tightness, and Proximal lesions, is a new evaluation criteria for RCH. Severity grading of Radial Club Hands improves assessment of functional prognosis, treatment planning, and comparison of similar extremity groups before and after treatment. Bayne-Klug classification appears to have a particular weakness because type IV will often change into type III during the growth.
