Fracture of the patella involving inferior pole is associated with postoperative patella baja - A retrospective multicenter study

• Published in: Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association
• Main Authors: Murase, Fuminori, Takegami, Yasuhiko, Tokutake, Katsuhiro, Oyama, Hiroki, Arakawa, Oki, Takatsu, Tetsuro, Nakashima, Hiroaki, Mishima, Kenichi, Imagama, Shiro
• Format: Journal Article
• Language: English
• Published: Japan Elsevier B.V 31.03.2024
• Subjects: Computed tomography; Inferior pole fracture of patella; Patella baja; Patellar fracture; Patellar fracture; Inferior pole fracture of patella; Computed tomography; Patella baja
• ISSN: 0949-2658; 1436-2023
• DOI: 10.1016/j.jos.2024.03.008

The patella fracture involving of inferior pole fractures (IPF) may be associated with patella baja, However, the clinical impact of this condition remains unclear. This study aims to clarify 1) the incidence of patella baja following patellar fracture surgery, 2) the associated clinical outcomes with and without the presence of patella baja, and 3) the potential correlation between the detection of IPF on CT and the occurrence of patella baja. We conducted a retrospective multicenter study involving 251 patients who underwent surgical treatment for patellar fractures. Patients were divided into the patella baja (PB; n = 49) group and patella norma (PN; n = 202) group. Data collected included demographics, radiographic findings, surgical details, and postoperative complications. We compared these items between PB group and PN group. Logistic regression analyses were used to identify risk factors for patella baja. Immediately following surgery, 36 (14.3%) patients presented with patella baja which increased to 49 cases (19.5%) at six months postoperatively. There is no statistically significant difference in the demographics, surgical details, clinical outcomes and complication between PB group and PN group. While, in the radiographical assessment, the prevalence of IPF on CT scan in the patella baja group was significantly higher than that in the patella norma group. By logistic regression analysis, IPFP on CT was identified as an independent risk factor for patella baja. (odds ratio 2.11, 95% confidence interval: 1.03–4.33, p = 0.042). In patients with patellar fractures, the incidence of patella baja increased from 14.3% immediately post-surgery to 19.5% at the six-month check-up. No significant differences were observed in clinical outcomes between the patella baja group and the norma group. The patella fracture involving IPF on CT emerged as a predictive factor for patella baja.