This document discusses interprosthetic femur fractures (IFFs), which occur between a hip and knee implant. It outlines risk factors for IFFs and challenges in treatment. The goals of surgery are to restore length, alignment, rotation, and preserve blood supply while allowing early mobilization. The Pires classification system and a proposed treatment algorithm are described. Treatment options include plate fixation, intramedullary nailing, or a combination. Studies on plate fixation report union rates ranging from 73-100%. Intramedullary nailing provides equivalent outcomes to plating with less blood loss and time. The "take home message" is that locking plates have become favored for IFFs due to stability in osteoporotic

1. A Review Article on Interprosthetic
Femur Fracture JB&JS2022
By Dr Pushpendra

2. • Interprosthetic femur fracture(IFF) are those which occur between an
ipsilateral hip and knee implant or prosthesis......

3. Risk factor
• Osteoporosis
• Osteomalacia
• Cortex thickness
• Medullary diameter to cortical width ratio
• Prosthesis size/ geometry
• infection

4. Challenge..
• Poor bone quality and quantity
• Unstable arthroplasty components
• Advanced patient age

5. Goals of surgery should include:
• Restoration of length,
• Alignment,
• Rotation,
• Early mobilization, and
• Preservation of blood supply.

6. Pires classification of interprosthetic femur2014

7. Proposed treatment algorithm based on the Pires classification system
2017

8. Treatment and results
• Treatment of choice for stable existing prostheses and
sufficient bone stock is osteosynthesis with
extramedullary(plate) and/or intramedulery(Nail) fixation
devices.
• In unstable implant revision arthroplasty is the choice.....

9. Plate fixation
• Sah et al. reported a 100% union rate in a review of 22 patients with IFFs who
underwent lateral LCP.
• Platzer et al. reported a 73% union rate in 23 pts undergoing MIPPO with
lateral lockingl plate
• Mamczack et al. reported a 80% union rate in 26 pts undergoing MIPPO with
lateral lockingl plate
• Mittal et al. and included 49 closed IFFs treated over a 10-year period using
MIPO with modern distal femoral locking plates. The authors reported a union
rate of 91%.All reported fractures had stable hip and knee component…………….
• Ruchholtz et al. treated 41 with polyaxial locking plates using either minimally
invasive or mini-open techniques achive 80% union.
• The authors suggested a minimal gap and/or overlap of at least 6 cm in
osteoporotic bone to avoid high stress concentration
• Augmenting plate fixation with cortical strut allografts can be considered in
the setting of IFFs with deficient bone stock or nonunion.

10. • Intramedullary nailing
• Richard et al. described a comparison of 30 patients treated with ORIF with
plate and screws compared with retrograde IMN
• which suggests that retrograde IMN may lead to equivalent outcomes as
compared with traditional plate osteosynthesis but with reduced blood loss
and surgical time and may provide an advantage in obese patients in relation
to soft tissue dissection.
• Limitation in case of IFF need open box TKA femoral component that can
accommodate nail placement.......

11. Combined Plate Fixation and Intramedullary Rod
Hussain et al and basci et al use this method and achived 100% union
• Use of a retrograde nail in the setting of ipsilateral THA has the drawback
of creating a stress riser between the tip of the nail and THA, which can be
mitigated by the application of a lateral femoral plate bridging the
implants

13. Take home massage..........
• Locking plates have become the implant of choice in
management of IFFs because of their improved stability in
osteoporotic bone, resistance to varus collapse, and ability
to be applied without excessive soft tissue stripping………