Year: 2025
Type: article
Study design: Observational Study
Abstract: Background: Patellar height changes may have significant clinical implications, particularly in the setting of revision total knee arthroplasty (rTKA).True patella baja (PB) is due to patellar tendon shortening, whereas pseudo-PB (PPB) is distal displacement of the patella due to joint line elevation.Our purpose was to examine the incidence and risk factors associated with PB and PPB following rTKA.Methods: A retrospective analysis of 415 rTKAs by a single surgeon between 2009 and 2019 was conducted.PB was defined by an Insall-Salvati ratio less than 0.8 and a Blackburne-Peel ratio less than 0.54.PPB was characterized by a relatively lower patella position compared to the joint line, but within the normal range of Insall-Salvati ratio (0.8-1.2) with a Blackburne-Peel ratio less than 0.54.Univariate and multiple regression analysis identified risk factors for PB and PPB.Results: After rTKA of 375 included knees, incidence of PB was 24% and PPB was 14%.Patients revised for infection were 9 times more likely to develop PB compared to other indications (P = .002).Number of prior surgeries and preoperative PB also increased the risk of postoperative PB (OR, 2.18; P = .013;OR, 319.90;P < .001).PB and PPB groups showed minimal change in range of motion from preoperative to final follow-up (-1.6 and 0.6 • ), whereas patients with normal patella height showed an average range of motion increase of 7.2 • .Conclusions: Identifying risk factors for PB and PPB such as preoperative patella height, number of previous surgeries, and revision indication of infection may help surgeons to address this difficult problem.
Source: Arthroplasty Today
Authors: Zachary Gapinski, Nichole Perry, Reese Courington, Ameer Tabbaa, Cody Green, George Haidukewych
Institutions: Orlando Health, Jewett Orthopaedic Clinic
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,500
OpenAlex ID: W4417136575