The Use of a Linear versus Curvilinear Oscillating Saw Blade for Femoral Head and Neck Excision Surgery in Cats

Case Report: The volume of residual femoral bone remaining following femoral head and neck excision (FHNE) was compared using either a curvilinear or a linear saw blade on an oscillating, battery-powered, instrument in feline cadavers with computed tomography (CT). Null hypothesis was that no difference would be found between saw blades or surgeons. Two novice surgeons were randomly assigned to perform bilateral FHNE in 5 cadavers each, using a 10-mm linear blade on one, and a 12-mm curvilinear blade on the contralateral limb. Post-FHNE coxofemoral joint CT scans were compared to bone volume removal expected as recorded by an experienced surgeon's assessment of the preoperative CT scans. Femoral fissure formation, damage to surrounding structures, and procedure time were assessed. Saw blade significantly affected residual bone volume left but was dependent upon the surgeon (p = 0.024) with surgeon A leaving significantly less residual bone using a curvilinear blade (Surgeon A: 0.116 cm3 ± 0.16; Surgeon B: 0.722 cm3 ± 0.77) compared to the linear blade (Surgeon A: 1.053 cm3 ± 0.71; Surgeon B: 0.399 cm3 ± 0.37). No femoral fissures occurred. Two femurs from each blade had excessive bone removed (greater or lesser trochanter). There was no significant difference in length of procedure time or differing blades used (p > 0.05). Use of the curvilinear versus linear saw blade may improve surgical resection of the femoral head and neck by some surgeons. Further study with experienced surgeons regarding residual bone, accuracy of bone resection and clinical outcome is warranted using a curvilinear blade to perform FHNE.