supracondylar periprosthetic fractures post tkr. nail plate devise- a new concept

Supracondylar femoral fracture is a devastating complication after a total knee replacement. Supracondylar femoral  fractures account for about  0.3 to 2.5 %.. With rising numbers of knee replacements the number of these fractures are going to rise.  The treatment is technically challenging in type 2 fractures .  In type 1 conservative treatment is acceptable and revision is advised in type 3

The benefits of total knee replacement have been well documented. Periprosthetic fractures involving distal femur, proximal tibia or patella especially during the postoperative period causes considerable morbidity to the patient and is a technical challenge to the treating surgeon.  Majority of these fractures occur after a trivial fall. Rheumatoid patients receiving corticosteroid and immuno suppressant  therapy, severe osteopenia and osteoporosis, old people, women are at a greater risk for supra condylar fractures. Severe osteoporosis makes fracture fixation difficult.  High incidence of supracondylar fractures (40-52%) has been reported with anterior femoral notching.

Both conservative and surgical modalities of treatment have been described in the management of  these fractures. Favourable results have been documented in certain studies  with conservative management . In general,  conservative methods may be utilized in type 1 fractures  ( Lewis and Rorabeck ), provided the patients are followed up with xrays at regular intervals . Displaced supracondylar fractures (type 2) needs to be properly aligned and stabilized for an optimal outcome. Stabilization using intramedullary nails, locking plates, external fixators have been described.   Type 3 fractures may require a revision with distal femoral replacement prosthesis or a structural allograft.  

Proper alignment and stabilization of the fracture is mandatory for early mobilization of the knee. In type 2 frequently the  far cortex is weak or communited, rigidity with a an intramedullary nail  or a locking plate  alone is suboptimal for mobilisation.  In such instances a combination of a nail plate devise  which are interconnected and locked to each other (locked screw on the plate and a locking nut on the screw and nail would increase the rigidity of the construct enabling early mobilisation of the patient. A blue print for such a devise and introducing instrument is given below.

In 2009 following difficulty in stabilising these distal femoral fractures,  combination of a separate  Intra medullary nail  and a locking  plate  was used to stabilise and mobilise the elderly  above mentioned osteoporotic fracture. This was  repeated in  bilateral case where in the nail was removed  to pass the distal locking screws  from the plate resulting in translation of the distal fragment refer   pictures   below.  Both the fractures healed in 3 months with no lag and loss of pre-fracture motion

 

 

 

 
 
 
 
 
 
 
 
 
 

 

 

 

 

 

Technique 

Knee replacement incision. A supracondylar nail 9 mm in diameter was passed through the distal fragment  and using this to reduce the fragment and pass it retrograde into the proximal fragment. This avoids soft tissue stripping and quick reduction of the fracture in anterior-posterior and medial lateral planes  with out soft tissue stripping associated with reduction with a plate device. This nail devise could be locked proximally and distally if possible or at this stage a locking plate is passed through a MIPPO technique on the lateral  femoral side through the same tkr incision and locking screws can be applied distally though the incision and percutaneous screws can be applied proximally. In the case  in picture on the right knee the nail was removed after the plate was applied distally to facilitate  screw insertion resulting in translation in the medio-lateral plane. Therefore it was decided to use both nail and plate in 3 further cases where in we obtained stable reduction to facilitate immediate mobilisation.

 With these results we attempted to design a new implant ( nail plate device) to improve the technique and rigidity of  fixation

jig to implant the nail plate devise

nail plate devise locking both together in cases of communition