- PreOp Planning:
- Proximal Exposure:
- if there is extreme difficulty in dislocating the hip, attempt to perform a wide capsulotomy or perform a trochanteric osteotomy;
- it is essential to avoid a proximal femoral frx while extracting the stem;
- before attempting prosthesis removal, remove granulation tissue and capsule around the neck of the prosthesis;
- if there is significant collar overhang that prevents access with burr, then the collar may have to be cut through first and removed with metal
cutting wheel or burr;
- lateral trochateric overgrowth and proximal-lateral cement:
- direct extraction of a femoral stem can be blocked by excessive cement or proximal bony overgrowth medial to the greater trochanter;
- it is necessary to remove the impedeing bone or cement which overly the lateral aspect of the stem (using high speed burr or chisel);
- the proximal lateral cement needs to be removed so that the femoral stem will pass more more easily thru the proximal femoral envelope;
- lateral aspect of the stem shold be visualized prior to stem removal;
- this has to be trimmed back to allow straight access down canal;
- if cement is present & overlies shoulder, it must be removed;
- if there is difficulty at this step, consider a trochanteric osteotomy;
- create a slot:
- unless cement comes out easily, then high speed bur is used to create a slot in the cement;
- once slot has been developed, cement chisels can be used with safety to chip out the cement;
- once slot has been created, cement can be chipped out & process repeated until the area of precoat or interlock is cleared, at which time stem will slide out;
- cement is cut w/ osteotomes & removed from around proximal portion of stem as far distally as can be done w/o damaging the bone;
- remove as much as possible of fragmented cement mantle or ingrown bone around the proximal third of the femoral comonent;
- w/ cemented prosthesis, some of remaining cement mantle may be tightly attached to the bone and must be removed w/ care to avoid penetration of femoral shaft;
- Stem Removal:
- extraction instruments:
- in some fortunate cases, the implant is so loose that whole cement mass & implant can be pulled out en mass;
- when cement has been removed down to shoulder, stem is extracted;
- distal window:
- it may be necessary to cut cortical window distal to the stem tip and drive the stem out;
- windows should be made in anterior cortex where stress is less
- references:
- Techniques for removal of the prosthesis and cement in total hip revisional arthroplasty. Moreland JR. Instruct Course Lect. 1991;40:163-170.
- Controlled perforation. A safe method of cement removal from the femoral canal.
- Retrograde stem removal in revision hip surgery: removing a loose or broken femoral component with a retrograde nail
- Residual Cement Removal (once stem is out)
- References:
Revision surgery for failed, nonseptic total hip arthroplasty: the femoral side.
Endoscopy for Cement Removal in Revision Arthroplasty of the Hip.