Overview
- Bimodal, high energy in the young and low energy in osteoporotic elderly
- Often periprosthetic around knee replacements
- AO/OTA extra-articular, partial articular and complete articular types
- Look for a coronal Hoffa fragment on CT
- Lateral locking plate, retrograde nail or distal femoral replacement
- Aim for articular reduction, restored length, alignment and rotation, and early mobilisation
Presentation by Dr Rekha Ganeshalingam
Distal Femoral Fractures by Dr Rekha Ganeshalingam from Orthofracs on Vimeo.
Classification
AO/OTA 33
| Type | Description |
|---|---|
| A | Extra-articular |
| B | Partial articular |
| C | Complete articular |
Original publication Meinberg EG, Agel J, Roberts CS, Karam MD, Kellam JF. Fracture and Dislocation Classification Compendium-2018. J Orthop Trauma. 2018;32 Suppl 1:S1-S170.
- B3 is the coronal plane Hoffa fracture, more often of the lateral condyle
Su periprosthetic
| Type | Description |
|---|---|
| I | Proximal to the femoral component |
| II | Originating at the proximal end of the component |
| III | Any part distal to the upper edge of the anterior flange |
Original publication Su ET, DeWal H, Di Cesare PE. Periprosthetic femoral fractures above total knee replacements. J Am Acad Orthop Surg. 2004;12(1):12-20.
Lewis and Rorabeck
| Type | Description |
|---|---|
| I | Undisplaced, prosthesis intact |
| II | Displaced, prosthesis intact |
| III | Loose or failing prosthesis regardless of displacement |
Original publication Rorabeck CH, Taylor JW. Classification of periprosthetic fractures complicating total knee arthroplasty. Orthop Clin North Am. 1999;30(2):209-14.
Investigations
- CT for all intra-articular fractures, since Hoffa fragments are easily missed
- In periprosthetic fractures assess component fixation, open or closed box design and bone stock
Management
- Deforming forces give shortening, varus and apex posterior angulation from gastrocnemius
- Hoffa fragments need perpendicular lag or headless screws
- Lateral locking plate with a long working length, as stiff constructs cause non-union
- Retrograde nail for extra-articular, simple articular and open box periprosthetic fractures
- Nail plate or dual plating allows early elderly weight bearing
- Distal femoral replacement for comminuted fractures in poor bone or a loose component
- Revision arthroplasty for Rorabeck III with adequate bone stock
Complications
- Metaphyseal non-union with stiff lateral plates
- Valgus, rotational and recurvatum malunion
- Knee stiffness
- One-year mortality in the elderly similar to hip fracture
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.