Inter‐ and intra‐observer reliability of radiographic scores commonly used for the evaluation of haemophilic arthropathy

Abstract

Although the severity of haemophilic arthropathy is commonly assessed using established radiographic scoring systems, there is limited available information about their inter- and intra-observer reliability. The purpose of the present study was to establish the inter-observer reliability (IEOR) and intra-observer reliability (IAOR) of three different methods available for the classification of haemophilic arthropathy, including the Arnold and Hilgartner classification, a modification to the Arnold and Hilgartner system described by Luck et al., and the classification described by Pettersson et al. Antero-posterior and lateral radiographs of 54 haemophilic joints were included for the analysis. To determine the IEOR for each one of the three radiographic systems, the radiographs were randomly evaluated by four observers, including two orthopaedic surgeons, one orthopaedic resident and one haematologist. For the determination of IAOR, all four reviewers repeated the assessment in a similar fashion, after a period of at least 2 weeks. IEOR and IAOR for the three classification systems was established using kappa (kappa) statistics. A Spearman rank correlation was used to determine the similarities between each reviewer's own interpretative scales. The IEOR was low for the Arnold and Hilgartner system (kappa = 0.35, P < or = 0.001) and the Luck system (kappa = 0.38, P < or = 0.001), but even lower for the Pettersson system (kappa = 0.06, P = 0.1). For the Pettersson system, particularly low kappa values were observed for the presence or absence of osteoporosis (kappa = 0.11, P = 0.0027), enlarged epiphysis (kappa = 0.10, P = 0.0039), erosion of joint margins (kappa = 0.11, P = 0.0018), and joint deformity (kappa = 0.16, P = 0.00001). However, a relatively high Spearman rank correlation for all three scales [r(s) = 0.75 (P < 0.001) for Arnold and Hilgartner system, r(s) = 0.74 (P < 0.001) for the Luck system and r(s) = 0.81 (P < 0.001) for Pettersson system] indicated an overall, general agreement among the reviewers with regard to the severity of the haemophilic arthropathy. There was a moderate IAOR value for both, the Arnold and Hilgartner system (kappa = 0.57, P = 0.00001) and the Luck system (kappa = 0.62, P = 0.00001) with a low IAOR value for the Pettersson system [kappa = 0.22, P = 0.00001). Currently available radiographic scoring systems for haemophilic arthropathy have low inter- and intra-observer reliability rates. Improvements, either through education or modification of the scoring systems, are critical in an era where correlations between clinical and radiographic scores have received significant attention.

Digital scoring of haemophilic arthropathy using radiographs is feasible

“…Moreover, the inter-observer variation of KIDA used for HA was not significantly different from that obtained with OA knee joints, for which KIDA was originally developed. Supportive in this respect was a recent publication by Silva et al, concluding that the currently available scoring systems for HA (including the Pettersson score), have low inter-and intra-observer reliability rates [20] and that improvements are needed in this respect. For the Pettersson parameters irregular subchondral surface, narrowing of joint space, erosions of joint margins, and gross incongruence of articulating bone ends, related KIDA parameters with good correlations (R ‡ 0.5) were available.…”

“…Moreover, the inter‐observer variation of KIDA used for HA was not significantly different from that obtained with OA knee joints, for which KIDA was originally developed. Supportive in this respect was a recent publication by Silva et al , concluding that the currently available scoring systems for HA (including the Pettersson score), have low inter‐ and intra‐observer reliability rates [20] and that improvements are needed in this respect.…”

Hemophilic Arthropathy of Shoulder Joints

“…A normal joint has a grade of 0. The Pettersson scoring system has been adopted by the World Federation of Hemophilia as the preferred radiographic classification system for hemophilic arthropathy 13,14 .…”

Three‐Dimensional Gait Analysis Can Shed New Light on Walking in Patients with Haemophilia

“…Information obtained from these scores is regularly used in clinical practice to evaluate the effects of different treatments on the progression of arthropathy, including clotting factor prophylaxis, physical therapy, and surgical procedures [6]. However, clinical joint scoring may not be sensitive to subtle changes in joint status and radiological examination does not provide an understanding of the causes underlying the impairments.…”