THE INSERTION OF DYNAMIC HIP SCREW FOR EXTRACAPSULAR FEMORAL NECK FRACTURES UNDER LOCAL ANAESTHETIC (SELECTION CRITERIA AND TECHNIQUE ARE DISCUSSED)

Abstract

Introduction: Many patients admitted to acute fracture units with femoral neck fractures are frail and elderly, dehydrated and malnourished, often with associated medical conditions. Surgery may be delayed for investigation, prolonged management and inadequate review of their medical problems, leading to clinical deterioration with poor outcome. Local anaesthetic techniques have been described for intracapsular fractures. We describe a technique effective for the treatment of the more difficult extracapsular type.

Aims: To provide a safe and effective technique using local anaesthetic and sedation, for the insertion of a dynamic hip screw in high risk elderly patients with extracapsular femoral neck fractures.

Method: Fifty elderly patients who sustained an inter-trochanteric fracture of their femoral neck underwent dynamic hip screw insertion under local anaesthetic and sedation. These patients were medically assessed following admission, all were ASA grade 4, had an additional medical condition (recent MI, CVA, chest infection, aortic stenosis) and were deemed unfit for either general or spinal anaesthesia. All patients not fit for traditional anaesthetic methods were assessed for their suitability for operation under LA, consented and placed on the next available theatre list.

A femoral nerve block was performed, with the aid of a nerve stimulator for accurate location, in the anaesthetic room; skin and periosteal infiltration was performed using a 22g spinal needle, with caution to include the distribution of the lateral cutaneous nerve. The patient was then placed on the fracture table and mild sedation (Ketamine, Diazemul, 02/N20) was administered, titrated against the patients requirements. The fracture was reduced using traction and internal rotation, and the DHS inserted.

Local Anaesthetic: Infiltration; * 20mls O.25% marcaine/1 in 200,000 adrenaline diluted to 40mls with sterile water. (30mls used with 10mls reserved) * 20mls 1% lidocaine diluted in 40mls of sterile water. (10mls used for skin). Local Anaesthetic femoral nerve block; * 10mls 0.25% plain marcaine

The combined amount of local anaesthetic used is well below safe limits recommended by the World Federation of Societies of Anaesthesiologists.

Conclusion: This technique is a safe, simple and effective method of allowing high risk, medically unfit patients to undergo surgery. It reduces operative bleeding and postoperative analgesia requirements, no peri-operative deaths occurred and one patient had evidence of post operative tachycardia that settled within 12 hours.