Treatment of Periprosthetic Knee Fractures with Plate and Screws and With Retrograde Intramedullary Nail: Indications, Limits and Medium-Term Follow-Up

Abstract

Periprosthetic knee fracture occur most frequently around the distal femur and are frequently complicated due to poor bone quality and comorbidities. Surgical treatment is typically necessary and requires varied techniques of open fixation, intramedullary fixation, or revision arthroplasty, due to fracture classification. The aim of the study is to report the results obtained in the treatment of periprosthetic knee fractures, comparing the results of two surgical techniques, retrograde intramedullary nail and ORIF with plate and screws. At our institute, a sample of 23 patients with periprosthetic knee fracture were surgically treated. In detail, our patient cohort consisted of 13 women (56.52%) and 10 men (43.48%) with a mean age of 71.91 years (SD ± 12.05) whose mean follow-up was 19.14 months (SD ± 9.90). In terms of treatment, 7 of 23 patients (30.43%) were treated with retrograde Intramedullary Nail (IMN), 2 patients (8.70%) underwent to revision of the prosthesis and 14 patients (60.87%) were treated with plate and screws (ORIF). The clinical evaluation was performed using two different clinical scores as reference, the Lysholm score and the Sanders score. The goal of treatment of periprosthetic knee fractures should be an early mobilization of the patient, in order to reduce the risk of prolonged immobilization, limiting surgical risks. Intramedullary nailing reduces blood loss and provides for shorter surgical times. However, it does not allow an anatomical reduction of the fracture and it is not always possible to achieve, due to the conformation of the prosthetic box. The mean results obtained from the evaluation by Lysholm Score was 58.75 ± 10.46 in group treated with IMN and 63.60 ± 6,82 in the group treated with ORIF. Sanders Functional Evaluation Score was 63.60 ± 6,82 in group treated with IMN and 28.26 ± 6.01 in the groups treated with ORIF. The results obtained are similar to the literature. Student’s t-test showed no statistical significance (p-value >0.05). Fractures healed on average at 4 months. We observed a case of mobilization of the nail. Intramedullary nailing reduces blood loss and provides for shorter surgical times. However, it does not allow an anatomical reduction and it is not always possible to achieve, due to the conformation of the prosthetic box. The ORIF with plate and screws allows an anatomical reduction of the fracture, but involves in greater risks. It appears, therefore, more suitable in relatively young subjects. The reduction and synthesis with MIPO technique appears a good compromise. However, it is not very effective in comminuted and multi-fragmentary fractures.