- Discussion:
- once femoral and acetabular components have been removed, residual cement can be removed from the femoral canal;
- it is better to move onto to the acetabular revision prior to cement removal since the cement will prevent blood loss from the canal;
- note: if gentamicin had been previously added to the component cement, then culture sample should be taken before the cement is disrupted (because
high levels of active gentamicin will be released);
- reference: Gentamicin release from old cement during revision hip surgery.
- Proximal Cement Column:
- as with component removal, lateral exposure (just medial to the greater trochanter is essential) to avoid metaphyseal perforation;
- if necessary trochanteric osteotomy is performed;
- adequate, lateral exposure is also essential for distal cement removal;
- instruments: splittng chisel, osteotomes and reverse rake;
- high speed burr may be used to thin cement in areas of osteoporotic metaphyseal bone;
- if cement splits and leaves a pointed leading edge, the compound C chisel can break it up;
- Murphy's Law:
- if lateral cement column is not entirely removed, there will be a strong varus force applied to the long stem component (during insertion), which may cause intraoperative femur fracture;
- Middle Cement Column:
- if femoral stem has been removed, leaving the cement column intact, consider screw insertion of an appropriately sized
sharp metal tap into the proximal cement column;
- after screwed into the proximal femur, the tap can then be hammered out;
- if only a proximal ring of bone is removed, consider re-insertion of metal tap more distally;
- cement is chipped away down to the level of the stem tip;
- w/ luck the residual cement is loose and can simply be pulled out;
- cement forceps are useful for at this stage;
- if large scallops, are present, cement chisels are used to go progressively down;
- remove cement as far distally as possible w/ osteotomes, which is possible for 10 to 15 cm down canal or upto area where stem tip was;
- remaining cement is removed with a high speed burr;
- when cement extends beyond curvature of femur, making straight access no longer possible, take great care to avoid perforation;
- cement can be safely removed more distally thru proximal femur if greater trochanter has be osteotomized or if flouroscopy has been used;
- whatever technique is used, a point is reached at which it is no longer safe to remove bone from above;
- Removal of Distal Cement Plug:
- w/ > 2 cm of cement entirely filling canal between stem tip & plug, consider using large windows;
- vastus is flapped forward and a windows is then cut length of the cement w/ a width of 1 cm;
- the cuts are angled so that the window is wedge shaped;
- Windows:
- Controlled perforation. A safe method of cement removal from the femoral canal.
- Tips of the trade #29. Femoral windows for easy cement removal in hip revision surgery.
- Femoral cement removal in revision total hip arthroplasty. A biomechanical analysis.
- Surgical Instruments:
- Moreland Cement Hook:
- used to remove distal cement plug;
- this is curved on one side and flattended on the other;
- curved end is placed against the wall distally, w/ flattended side facing the femur;
- it is gently tapped with a hammer until it bypasses the cement;
- hook is then turned to face cement, and the handle is struck sharply with a slap hammer;
- Mueller Cement Reamers:
- smallest reamer is mounted on the T handle;
- w/ careful visualization of distal portion of femur in 3 dimensions, tip of the reamer is placed in center of cement mass and tapped with a hammer and twisted;
- this is continued until reamer penetrates the cement;
- if inserted off center, reamer can penetrate bone;
- larger reamers are progressively used until a small cement hook can be passed;
- cement hooks are then used to remove all residual cement;
- High speed burr can also be used but is best used under flourscopic control
- Segmental Cement Extraction at Revision Total Hip Arthroplasty.
- contra-indications:
- femoral fracture, distal cement mantel flaring, extrusion of cement thru a previous cortical defect;
- equipement:
- a coated threaded rod which is longer than the cement mantle;
- technique:
- femoral stem is removed using standard techniques;
- a 0.64 cm drill bit is used to drill thru the distal cement plug;
- residual cement is cleaned w/ wire brush to remove any soft tissue membrane, and is then irrigated;
- canal is dried with gauze;
- cement is mixed at low temperature (to minimize viscosity) and is then injected into the medullary canal upto the level of the lesser trochanter;
- a threaded rod is then inserted into the center of the medullary canal;
- once the cement has hardened, the threaded rod is back out;
- threaded extraction rods are then inserted no more than 2 cm at a time;
- a slap hammer is used to sequentially remove small segments of cement
Thermal Tissue Damage Caused by Ultrasonic Cement Removal from the Humerus.
Segmental cement extraction at revision total hip arthroplasty.
Femoral cement removal in revision total hip arthroplasty: a biomechanical analysis.
Endoscopy for Cement Removal in Revision Arthroplasty of the Hip.
Methods of removing excess bone cement.
Persistent infection associated with residual cement after resection arthroplasty of the hip.