- Operative Considerations (see IM nailing and Synthes IM Nail);
- should be considered when x-rays show more than 50% loss of the shaft diameter on any view;
- risk of pathologic frx is low for lesions involving 50% of the shaft diameter (assuming that patient is touch down weight bearing), but rises dramatically
after the lesion involves more than 75% of the shaft diameter;
- prior to IM nailing for pending pathologic frx, it is necessary to ensure that the lesion in question is in fact a carcinoma rather than a sarcoma (such
as chondrosaroma) which have disasterous consequences if a nail were driven thru it;
- one should be especially suspicious with the mixed lytic/blastic type lesion (as may be seen in breast or prostatic ca);
- term "millary sarcomatous metatasis" has been given to cases in which an IM nail has been driven thru a femoral sarcoma (the lung
is filled with countless sarcomatous metatasis);
- lesser troch avulsion is not an uncommon presentation of metastatic bone dz, but has also been described as initial indicator of chondrosarcoma;
- reference: Avulsion Fracture of the Lesser Trochanter as a Result of a Primary Malignant Tumor of Bone. A report of four cases.
- bone scans
- help pick up additional metastatic lesions, and may lesions which were not noticed on plain radiographs;
- if operative fixation of a pending femoral shaft frx is planned, we need to know whether there is metatstatic involvement in proximal or distal femur;
- prophylaxis against FES:
- note that patients w/ lung carcinoma or w/ significant metatasis to the lungs may be especially sensitive to fat embolism syndrome;
- intramedullary nails are inserted without femoral reaming;
- bilateral IM nailing should be done with caution (FES rates may reach 100%);
- preoperative steroids:
- hydrocortisone 100 mg IV q6 hrs which is started the evening before the case;
- Fat embolism prophylaxis with corticosteroids. A prospective study in high-risk patients.
- 'Low-dose' corticosteroid prophylaxis against fat embolism.
- Fat embolism and the fat embolism syndrome. A double-blind therapeutic study.
- The use of methylprednisolone and hypertonic glucose in the prophylaxis of fat embolism syndrome.
- canal venting:
- the femur is most efficiently vented by inserting a cannulated femoral nail without a guide wire;
- proof of femoral venting is revealed when the medullary contents are extruded from proximal end of nail, as the nail is driven forward;
- prior to insertion of the IM nail, consider venting the medullary canal inorder to avoid FES;
- make a stab wound over the distal metaphyseal-diaphyseal junction and spread down to bone;
- insert a 4.0 mm cannulated drill bit over a guide wire into the medullary canal;
- Intramedullary pressure changes and fat intravasation during intramedullary nailing: an experimental study in sheep.
- Novel Venting Technique for Intramedullary Rod Fixation of Pathologic Fractures
- radiation therapy
- in the report by M. Assal et al 2001, the authors evaluated 12 pathologic and impending pathologic fractures which were
stabilized with the synthes spiral blade plate;
- two patients required bilateral nailing which was staged over 2-3 weeks;
- average post surgical survival was 6 months;
- one patient died during surgery from a fat embolism;
- the authors noted that although nails were inserted without reaming, this did not avoid the risk of fat embolism
Metastatic bone disease. A study of the surgical treatment of 166 pathologic humeral and femoral fractures.
Isolated fracture of the lesser trochanter in adults: an initial manifestation of metastatic malignant disease.
Metastasis size in pathologic femoral fractures.
Osteosynthesis of metastatic lesions of the proximal femur with a solid femoral nail and interlocking spiral blade inserted without reaming.