Supracondylar nailing for difficult distal femur fractures

Journal of Orthopaedic Surgery, Dec 2003 by Saw, A, Lau, C P

ABSTRACT

Purpose. To evaluate outcome following supracondylar nailing for distal femur fractures.

Methods. The clinical and radiological outcome for 13 patients treated between January 1995 and December 1998 at the University Malaya Medical Center was assessed. Patients were seen for follow-up for a mean duration of 20.2 months.

Results. There were no cases of non-union or infection. Overall assessment of clinical outcome based on the criteria of Schatzker and Lambert was graded excellent in 6 patients, good in 3 patients, fair in 3 patients, and one graded as a failure.

Conclusion. Supracondylar nailing for fixation of supracondylar (Arbeitsgemeinschaft fur Osteosynthesefragen [AO] type A) and less comminuted intercondylar (AO type C1 and C2) fractures is recommended by the authors.

Key words: femoral fracture; internal fixators; treatment outcome

INTRODUCTION

In treating distal femur fractures, it can be difficult to maintain bony alignment, due to the unbalanced pull of thigh and calf muscles. For cases treated with internal fixation, bony purchase of the distal fragment may not be adequate due to the paucity of good cortical bone. In 1967, Neer et al.1 recommended a nonsurgical approach to supracondylar fractures after reviewing 110 unselected cases, noting a high rate of local complications and a low rate for patient satisfaction. Early conversion to cast bracing after a period of traction was later introduced,2,3 claiming to offer better functional outcomes compared with prolonged casting across the knee. Later, fixation with a lateral condylar blade plate or its modifications became popular, because it allowed fixation of intraarticular fractures and early mobilisation of the knee joint.4-6 However, soft tissue disruption with open reduction and periosteal stripping for placement of the implant may interfere with the healing process, resulting in a delay in union or non-union. Bone grafting was frequently indicated5,7 and wound infection was not uncommon with this approach.4,8,9 Flexible intramedullary nailing,10,11 modified antegrade nailing,12,13 and external fixation14 allowed fracture fixation with minimal exposure of the fracture site. However, axial and rotational stability of these implants were inferior, and early mobilisation of the limb could result in loss of reduction. Retrograde insertion of a standard femur nail did not allow fixation of very low fractures in addition, and free hand interlocking of the proximal end could be difficult.

Supracondylar nailing was initially introduced for the treatment of low femur shaft fractures. Due to the distal position of the interlocking screws, they were later used for distal femur fractures. Fixation of intercondylar fractures was also possible with additional compression screws to stabilise the intra-articular fragments.15,16 In cases with severe metaphyseal comminution, supracondylar nailing offers a more biological method of fixation with less devitalisation of soft tissue. However, outcome evaluation of this treatment has been limited.15,16 We reviewed the medical records of 14 patients treated with supracondylar nailing for distal femur fractures at our institution over a 3-year period, to determine overall outcome in this patient group.

METHODS

From January 1995 to December 1998, approximately 400 intramedullary nailing procedures were performed for femur fractures in our institution, with 14 patients undergoing supracondylar nail fixation. During the period of study, lateral condylar blade plate or dynamic condylar screws were the implants of choice for intercondylar fractures, and for supracondylar fractures too low for standard antegrade femur nailing. Indications for supracondylar nail fixation included distal femur fractures with severe comminution or segmental fractures, the presence of pre-existing deformity that rendered lateral plate fixation difficult, and selected intra-articular fractures. Unicondylar fractures (Arbeitsgemeinschaft fur Osteosynthesefragen [AO] type B) were better treated with either compression screws or buttress plates. Fractures with intra-articular comminution (AO type 3C) were usually treated with circular frame external fixation.

Surgery was performed with the patient in supine position on a standard operating table that allowed imaging of the knee with image intensifier. Knee flexion was achieved by placing sterile linen under the knee. No tourniquet was used. For extra-articular fractures, a midline infra-patellar incision extending through the patellar tendon was used, to assess the entry point on the intercondylar notch. For displaced intercondylar fractures, an anterior midline skin incision with parapatellar arthrotomy was performed for open reduction. The 2 condylar fragments were initially fixed with AO cancellous screws. If the fracture extended close to or through the intercondylar notch, the entry hole of the nail had to be created by connecting multiple drill holes, in order to avoid splitting of the 2 condyles. The distal interlocking screws of the nail provided additional fixation to the condylar fragments. In open fractures, location of the open wound governed the skin incision and approach to the fracture. Knee joint mobilisation without weightbearing was allowed after the second postoperative day.