Three-dimensional-printed custom-made patellar endoprosthesis for recurrent giant cell tumor of the patella: A case report and review of the literature

Abstract

BACKGROUND Giant cell tumor (GCT) is a benign lesion and rarely involves the patella. This disease is characterized by a relatively high recurrence rate after primary treatment. En bloc resection has been a predominant option for recurrent GCT. However, total patellectomy can lead to disruption of the knee. Therefore, exploration of functional reconstruction of the extensor mechanism is worthwhile. CASE SUMMARY A 54-year-old woman presented with right knee pain and swelling, and was diagnosed as having a GCT in the patella following curettage and autograft. Medical imaging revealed a lytic and expanded lesion involving the whole patella with focal cortical breaches and pathological fracture. Based on the combination of histological, radiological, and clinical features, a diagnosis of recurrent GCT in the patella was made (Campanacci grade III). After a multidisciplinary team discussion, three-dimensional (3D)-printed custom-made patellar endoprosthesis was performed following en bloc resection for reconstructing the extensor mechanism. The patient was followed for 35 mo postoperatively. No evidence of local recurrence, pulmonary metastasis, or osteoarthritis of the right knee was observed. The active flexion arc was 0°-120°, and no extension lag was detected. A favorable patellar tracking and height (Insall-Salvati ratio 0.93) were detected by radiography. CONCLUSION We depict a case of a GCT at the right patella, which was successfully treated by patellectomy and 3D-printed custom-made endoprosthetic replacement. The patella normal reconstruction, the precise-fit articular design, and gastrocnemius flap augmentation could lead to satisfactory knee function and a low rate of complications in the short-term follow-up.

Knee Extensor Apparatus Reconstruction with Allograft after Patellar Resection: A Case Report

“…Some case reports and technical notes so far published regard lesions confined to the anterior knee or associated with distal femur or proximal tibia that required megaprosthetic reconstructions. Several solutions have been proposed and described through the last decades, including systemic and prosthetic augments [3,4], autologous tissues [5], and allografts [4,[6][7][8]. Reconstructive solutions include biological [3,4,[6][7][8] and nonbiological implants [4,5], both of them with their pros and cons.…”

“…Several solutions have been proposed and described through the last decades, including systemic and prosthetic augments [3,4], autologous tissues [5], and allografts [4,[6][7][8]. Reconstructive solutions include biological [3,4,[6][7][8] and nonbiological implants [4,5], both of them with their pros and cons. Although synthetic augments often have good mechanical properties, they lack bio-integrative properties, and their performances may decrease over the years.…”

“…These lesions often require massive resections to achieve wide margins, and a proper anatomical reconstruction is fundamental to restoring the continuity and function of the extensor apparatus [ 2 ]. Despite the recent advances in surgical techniques, bioengineering, and bone allograft banking, the reconstruction of the extensor apparatus after wide resection still represents one of the most challenging procedures in orthopedic oncology [ 2 , 3 ]. To this date, a consensus about the best reconstructive approach still needs to be established.…”