Open vs. closed patella Fractures: Difference in incidence, treatment and outcomes

Background: This study aims to describe the incidence and compare treatment and outcomes of open versus closed patella fractures at one institution. Methods: Adult patients presenting to one American College of Surgeons Level 1 trauma hospital from 01/01/2001-12/31/2020 with patella fracture(s), screened by ICD codes were retrospectively reviewed. The primary outcome was the incidence of peri-injury or perioperative complications, including nonunion, superficial or deep infection, contracture/arthrofibrosis, deep venous thrombosis (DVT), hardware failure, patellar tendon rupture, painful hardware, wound healing complications, or return to the operating room (RTOR). Rates of postoperative complications were compared between fracture types (open vs closed) and treatment strategies (operative vs non-operative). All analyses were performed in R version 4.5.0. P-value <0.05 was significant. Results: Of 451 patients, (median age 52 years), 35.3 % were open fractures, and 62.3 % underwent operative treatment. Patients with open fractures were younger (mean age 38.84 ± 15.67 vs. 58.27 ± 19.45 years; p < 0.001) and more commonly smokers (37.1 % vs. 27.4 %; p = 0.043). Open fractures had higher Injury Severity Scores (ISS) (12.81 ± 8.41 vs. 10.30 ± 8.28; p = 0.003) and were treated operatively more frequently than closed fractures (84.9 % vs. 50.0 %; p < 0.001). Open fractures demonstrated a higher rate of any complication (38 [23.9 %] vs 42 [14.2 %], p = 0.014), as did patients treated operatively (78 [27.8 %] vs 2 [1.2 %], p < 0.001). Patients who underwent RTOR were younger than those who did not (median 42.9 vs 53.7 years; p < 0.001). Open fracture and postoperative complications were significantly associated with RTOR. Conclusion: In this cohort, open patella fractures occurred at a higher rate than previously described in the literature at 35.3 %. Open fracture was significantly associated with increased risk of complications and unplanned RTOR.