Modified use of the proximal humeral internal locking system (PHILOS) plate for distal femoral nonunions

Abstract

Purpose: Nonunion is a common complication after a distal femoral fracture (DFF). Standard treatment consists of revision plating and/or bone grafting. Single lateral plating for a distal femoral nonunion can be insufficient in case of a persistent medial gap and compromised bone stock. Alternatively, dual plating can be used to treat a distal femoral nonunion, but to date there is no Gold standard. The aim of our study was to report our results after use of a minimally invasively placed proximal humeral internal locking system (Philos) plate as a medial buttress in the treatment of a distal femoral nonunion.

Methods: Fifteen adult patients with a distal femoral nonunion were prospectively entered in a trauma database and retrospectively assessed. All patients underwent a similar operation, which included removal of failed hardware, nonunion debridement, fixation with a lateral plate, and a medial Philos plate combined with bone grafting. Data collected included union rate, time to union, complications and functional outcome.

Results: In twelve out of fifteen patients (80%), the fracture united after our index operation. Median time to union was 4.8 months (range 1.6-15). Three patients (20%) needed additional bone grafting surgery. One patient underwent a Judet quadricepsplasty.

Conclusion: This study suggests that the Philos plate is a safe and effective adjunct as a medial buttress plate for distal femoral nonunions.

Keywords: Distal femoral fracture; Dual Plating; Nonunion; Philos.

Fig. 1

Application of the Philos plate on the distal femur. Medial incision on the distal femur (a). The Philos plate which is inserted along the medial border using a small single incision (b) Percutaneous minimal invasive attachment of the plate to the femur (c, d)

Fig. 2

A seventy-six year old female was referred to us after several attempts to heal a comminuted extra-articular distal femur fracture (33A3) (a). Initial fracture treatment in another institution consisted of a LISS plate (b). Revision surgery with a new LISS plate and cerclage around hip prosthesis was performed 8 months after initial fracture treatment (c). Three days later a second revision surgery with a LISS plate was performed due to malposition of the previous plate (d). Six months later the patient underwent additional bone grafting surgery and was then referred to us with a persistent nonunion. At 20 months after the initial fracture we performed our index nonunion surgery with a 95-degree condylar blade plate and a Philos plate medially. In addition, autologous bone grafting was performed (e). Another bone grafting surgery with addition of three cancellous screws was performed six months later. Union was confirmed 2 months later (f). Radiographic imaging 19 months after index nonunion surgery show bone union and a well preserved knee joint (g)