Comparison of radiographic scoring systems for assessment of bone healing after tibial plateau leveling osteotomy in dogs

Abstract

IntroductionAccurate radiographic assessment of bone healing is vital in determining both clinical treatment and for assessing interventions aimed at the promotion of bone healing. Several scoring systems have been used to evaluate osteotomy changes following tibial plateau leveling osteotomy (TPLO). The goal of this study was to compare the ability of five radiographic scoring systems to identify changes in bone healing following TPLO over time (Aim I), and to evaluate the influence of limb positioning on TPLO osteotomy scoring (Aim II).Materials and methodsPhase I-A randomized, blinded, prospective study was conducted using similarly positioned postoperative TPLO radiographs from seven dogs taken immediately postoperatively, 6-weeks, and 8-weeks postoperatively. Ten reviewers assessed the radiographs, and five different scoring systems were tested for each set including three previously published ones, a Visual Analog Score (VAS), and a subjective 11-point scale. For each system, responses for 6-week postoperative were compared to 8-week postoperative. Scores were judged as correct (=showing an increase in score), incorrect (=decrease in score), or unchanged (=same score). Phase II-An international group of 39 reviewers was asked to score radiographs from three dogs, taken in different positions, using the VAS grading system. Scores were averaged and comparisons were made for each set.ResultsPhase I-The VAS system identified the greatest number of sets correctly (76%), with the least unchanged scores (15%), and 9% incorrect scores. Phase II-All three patients had an increase in the average difference between VAS-scores for differently positioned radiographs compared to similarly positioned radiographs. The magnitude of change between different positions far exceeded the magnitude of comparison of the similarly positioned radiographs from the 6- and 8-week time point.Discussion/ConclusionThe VAS system appears to be the most appropriate of the tested systems to identify small changes in bone healing. In addition, the positioning of postoperative TPLO radiographs makes a substantial difference in the healing score that is assigned. Care must be undertaken when performing postoperative radiographs in both the clinical and research setting to ensure accurate assessment of bone healing.

Evaluation of Osteotomy Healing in Boxer Dogs Undergoing Tibial Plateau Levelling Osteotomy Using Two Radiographic Scoring Systems

“…A recent study comparing three previously described systems (including the 5-point system used in the current study) and two novel systems for assessment of bone healing after TPLO, found that the Visual Analogue Score system was the most appropriate to identify smaller changes in bone healing; this system was a novel variation of the 5-point scoring system with the addition of a 100-point scale, where 0 was labeled as "no healing" and 100 as "completely healed." 20 Intra-or interobserver reliability was not measured, and the 10-point scoring system was not included, making it difficult to compare their results with the ones of the present study.…”

“…Osteotomy healing following TPLO has been evaluated in multiple studies, and a 5-point (0-4) scoring system evaluating osseous bridging is commonly utilized. [14][15][16][17][18][19][20] A 10-point (0-10) scoring system was later developed, specifically for evaluation of bone remodelling at the osteotomy site in standard TPLO radiographs and although it appeared to provide a more sensitive evaluation of osteotomy healing, inter-and intraobserver variability were not evaluated in this study. 18 Other scoring systems have been used and compared; however, there is currently no standardized scoring system for the evaluation of osteotomy healing in veterinary medicine.…”

“…18 Other scoring systems have been used and compared; however, there is currently no standardized scoring system for the evaluation of osteotomy healing in veterinary medicine. 19,20 The objectives of the present study were (1) to compare the previously reported 5-point and 10-point scoring systems evaluating osteotomy healing on postoperative TPLO radiographs of Boxer dogs and Labrador Retriever dogs, and (2) to determine whether radiographic healing differs in Boxer dogs compared with age-matched Labrador Retrievers. The first null hypothesis was that there would be no difference in intra-and interobserver variability between the two scoring systems.…”