Patellar fractures account for approximately 1% of all skeletal fractures and can disrupt extensor function and damage the articular surface of the patellofemoral joint [1]. Patella fracture involving inferior pole fractures of the patella (IPF), typically less than 15 mm in length in the sagittal plane, occurred in 9.3–22.4% of patellar fractures [2]. The presence of IPF suggests damage to the knee extensor mechanism and may have a significant impact. The diagnosis of IPFs are often not accurately assessed through radiographic evaluation. Previous research has shown that numerous inferior pole fractures are not detected on radiographs but only on computed tomography (CT), thus highlighting the necessity for preoperative CT evaluation [3]. Surgical treatment is recommended for displaced fractures of the inferior pole of the patella to restore the extensor mechanism of the lower extremity.

Several risk factors can contribute to poor outcomes after surgery for IPFP, such as age [4], severe displacement of fracture site [5], and patellotibial wire technique [5]. However, few studies have examined the clinical outcomes of IPF that are not evident on radiographs.

Patella baja, which is a condition characterized by a low-lying patella, was known to cause anterior knee pain, impingement, extensor lag and decreased range of motion in the patients who have undergone total knee arthroplasty [6] or anterior cruciate ligament reconstruction [7].

The prevalence of patella baja following patellar fracture surgery, as well as its impact on clinical outcomes, has not been enough documented [8]. Furthermore, the correlation between the presence of IPF on CT and the development of patella baja is not comprehensively understood.

This study aims to ascertain 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 and investigate whether IPF could be a risk factor for postoperative patella baja.