Objective To explore the selection strategy of diagnostic and therapeutic regimens and assess the efficacy for postoperative infection following internal fixation of patellar fractures.

Methods A retrospective analysis was conducted on the clinical data of 12 patients with postoperative infection after internal fixation of patellar fractures.

Results A total of 6 patients underwent complete removal of the internal fixation devices during debridement and were subsequently fixed with knee braces, while the other 6 had their original internal fixation devices removed and replaced with Kirschner wire fixation. Three patients developed septic arthritis and underwent knee arthroscopic lavage treatment. All 12 patients underwent bacterial culture and metagenomic next-generation sequencing (mNGS) testing, and the key pathogenic bacteria were successfully identified by mNGS. All wounds achieved primary healing within 2 weeks after closure. At the final follow-up, all patients exhibited good fracture healing, with Böstman patellar fracture function scores ranging from 24 to 29 (mean score of 26.58), and the outcomes were evaluated as excellent in 7 cases and good in 5, resulting in an excellent and good rate of 100.0%.

Conclusion For patients with early and delayed postoperative infections following internal fixation of patellar fractures, removal of the internal fixation devices can help reduce the risk of infection recurrence. For patients with concurrent septic arthritis, early diagnosis and timely implementation of arthroscopic joint debridement and irrigation and drainage are crucial.