Spacer blocks are used commonly in knee arthroplasty to estimate gaps and ligament balance. Their use continues along with modern technology despite dearth of literature regarding their accuracy and reliability. This prospective study aims to determine the difference in values of gap and balance measurements between spacers and trials in computer assisted TKA.
50 patients with moderate varus deformity of <20° undergoing primary TKA were recruited for this prospective study. After navigation assisted cuts and requisite ligament release, gaps and balance were recorded in extension and 90° flexion with spacer block followed by implant trials.
There were 33 females and 17 males with average BMI of 28.2 ± 5kg/m
Spacer blocks do not estimate extension space accurately with knee achieving 6.2 more flexion with trials as compared to spacer blocks when assessed for sagittal plane correction in extension. Spacer blocks should pass in easily in extension to avoid any flexion deformity when the actual trials are inserted.