What is the medical problem?
Fractures of the upper part of the thigh bone (femur) are termed hip or proximal femoral fractures. These fractures are most common in women aged over 65 years. Roughly two out of five hip fractures are 'extracapsular' in that they lie outside the hip joint capsule.
What treatments are available?
The majority of these fractures are fixed surgically using metal implants. One increasingly used implant is the 'intramedullary nail'. This consists of a metal rod, which is usually inserted from the upper end of the femur into the inner cavity (medulla) of the femur bone and held in place with screws. There are several different types of nails, usually made by different manufacturers, in use.
Are some intramedullary nails better than others for these fractures?
This review set out to examine the evidence from trials that compared different designs of nails in clinical practice.
We searched medical databases and registers of new studies (until January 2014) and found 17 trials that compared different nail designs. These involved a total of 2130 participants. Most participants were older women.
The quality of the evidence from these trials is low or very low, partly because most trials used flawed methods that mean their results may not be reliable. In addition, several trials did not report on function or provide data that could be used. Of the 12 different comparisons tested, nine were tested by one trial only.
Four trials compared the proximal femoral nail (PFN) with the Gamma nail in 910 older adults. Two trials compared the ACE intramedullary nail with the Gamma nail in 185 older adults. Two trials compared the proximal femoral nail antirotation (PFNA) with the Gamma 3 nail in 200 older adults. The other nine trials were single comparisons of different types of nail designs.
Overall, the weak evidence available for all 12 comparisons showed no important differences in outcome (function, mobility, pain, death, fracture fixation complications and revision surgery) between the two nails or two nail designs under test. There was one possible exception. There was weak evidence from one trial of 215 older adults that the ENDOVIS nail resulted in poorer mobility (more people could not walk after their operation) when compared with the intramedullary hip screw (IMHS). However, more evidence is required to be confident of this result.
In conclusion, the available evidence is insufficient to determine whether there are important differences in outcome between different designs of intramedullary nails used for fixing extracapsular hip fractures. In terms of future research, we propose that priority is given to comparisons of intramedullary nails with another type of device in common use, the sliding hip screw.