Primary and Metastatic Bone Tumors of the Patella: Literature Review and Institutional Experience.

Background: Patellar tumors are rare but certainly must be considered in the differential diagnosis in patients with knee pain. Diagnosis can be challenging as often patellar neoplasms are confused with benign conditions and their clinical presentation is usually not specific. We performed an institutional and a literature review to determine what are the most common tumors affecting the patella and what is the best management. Methods: This is a case series from our institution including all patients with benign, malignant, and metastatic patellar neoplasms. Charts were reviewed for patient demographics, clinical presentation, pathology characteristics, radiographic classification, and oncologic and functional outcomes. Results: Twenty-four patients were identified; twelve patients had benign lesions, 10 metastatic and 2 primary malignant tumors. Chondroblastoma and Giant Cell Tumor were the most common tumors. Management of benign lesions with intralesional curettage and packing with bone graft or cement demonstrated excellent results with no local recurrence. In terms of malignant tumors, the spectrum of treatment is variable; it could range from medical management alone or in combination with surgical procedures to total patellectomy with reconstruction of the extensor mechanism. Conclusion: Patellar tumors should be part of the differential in patients with chronic knee pain that does not respond to initial conservative interventions. Recurrence rate with intralesional curettage and bone grafting or cement packing is very low and therefore should be the treatment of choice for benign intraosseous neoplasms. Resection with negative margins in malignant neoplasms or bone metastasis decreases local recurrence but only in the former group there is a potential impact in survival.