INTRACAPSULAR FRACTURES. FIXATION OR PROSTHESIS: OPEN VERSUS MINI INVASIVE?

Abstract

In the trend to operate hip fractures with less invasive procedures it is important to realise that the semi-percutaneous approach to make osteosynthesis with two screws or hook pins for femoral neck fractures, actually is a mini invasive procedure. It is well proven since decades.

The major question is to select the right patients for osteosynthesis versus arthroplasty (unipolar hemi, bipolar hemi or total hip arthroplasty). It is depending on the damage to the blood supply of the femoral head. There is at the moment no methods for this in routine use, but with the development of MRI techniques it might be possible. The goal is to select the right patients for osteosynthesis to minimise the healing complications and the need for secondary hip arthroplasties.

The hook pin procedure has been extensively used in Sweden through decades. Since the last 5 years there is an increasing trend for the most displaced fractures in older patients to be operated with a hemi arthroplasty. Previously a primary osteosynthesis was the first choice in all patients. The results of 10 years use of this procedure in Lund 1988–1997 shows that for the total of femoral neck (cervical) hip fractures the need for a secondary arthroplasty within 2 years was 20%. Previously published need for secondary arthroplasty was 13% when only well trained surgeons operated. There is thus no need to behead all displaces femoral neck fractures because some fail. In Norway the principles of primary osteosynthesis still mostly prevail. In a randomised comparison between hook pins and screws it was found that the rates of early failure of fixation, non-union and need for reoperation did not differ significantly between the two osteosynthesis methods. The use of hook pins was associated with less drill penetrations of the femoral head during surgery (odds ratio 2.6) and a lower incidence of necrosis of the femoral head (odds ratio 3.5). The technique of performance was of significant importance. There was a highly significant relationship between poor reduction and poor fixation of the fracture and subsequent reoperation. Likewise per-operative drill penetration of the femoral head was associated with a greater risk of reoperation. In total 22% of these patients needed a major reoperation (usually hemi arthroplasty). In 7% of the cases the fixation device needed to be removed after a healed fracture. In another randomised study between hook pins and three screws 57% of the patients were operated within 6 hours from admission to hospital and 92% within 24 hours. The mean (median) time for operation was 36 (30) minutes for the hook pins and 40 (35) minutes for the AO screws. After 2 years 77% of the hook pin patients had not needed any reoperation compared to 73% in the AO screw group. In total a secondary hemiarthroplasty had been performed in 7% and a total hip arthroplasty in 12% of the patients. Extraction only of osteosynthesis material had been performed in 5%. Again, healing was much higher if the reposition and positioning of the osteosynthesis material was optimised.

Osteosynthesis is a mini invasive procedure. It is indicated for all undisplaced cervical fractures and for less displaced fractures, particularly in younger patients. Attention to the reposition and positioning of the osteosynthesis material is necessary. An image intensifier with large field of view and good resolution facilitates this, preferably a biplanar. The future goal is to select the patients better for the different procedures osteosynthesis or arthroplasty.