Intramedullary nails for extracapsular hip fractures in adults

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.

Authors' conclusions: 

The limited evidence from the randomised trials undertaken to date is insufficient to determine whether there are important differences in outcome between different designs of intramedullary nails used in treating extracapsular hip fractures. Given the evidence of superiority of the sliding hip screw compared with intramedullary nails for extracapsular hip fractures, further studies comparing different designs of intramedullary nails are not a priority. Any new design should be evaluated in a randomised comparison with the sliding hip screw.

Read the full abstract...
Background: 

Intramedullary nails may be used for the surgical fixation of extracapsular hip fractures in adults. This is an update of a Cochrane review first published in 2005 and last updated in 2008.

Objectives: 

To assess the effects (benefits and harms) of different designs of intramedullary nails for treating extracapsular hip fractures in adults.

Search strategy: 

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (6 January 2014), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 12, 2013), MEDLINE (1966 to November Week 3, 2013), MEDLINE In-Process & Other Non-Indexed Citations (3 January 2014), EMBASE (1988 to 2014, Week 1) and the World Health Organization (WHO) International Clinical Trials Registry Platform (accessed January 2014).

Selection criteria: 

All randomised or quasi-randomised trials comparing different types, or design modifications, of intramedullary nails in the treatment of extracapsular hip fractures in adults.

Data collection and analysis: 

At least two review authors independently selected studies, assessed risk of bias and extracted data. We performed limited meta-analysis using the fixed-effect model.

Main results: 

We included eight new trials, testing seven new comparisons in this update. Overall, we included 17 trials, testing 12 comparisons of different cephalocondylic nail designs. The trials involved a total of 2130 adults (predominantly female and older people) with mainly unstable trochanteric fractures.

All trials were at unclear risk of bias for most domains, with the majority at high risk of detection bias for subjective outcomes. The three quasi-randomised trials were at high risk for selection bias.

Four trials (910 participants) compared the proximal femoral nail (PFN) with the Gamma nail. There was no significant difference between the two implants in functional outcome (the very low quality evidence being limited to results from single trials), mortality (low quality evidence: 86/415 versus 80/415; risk ratio (RR) 1.08, 95% confidence interval (CI) 0.82 to 1.41), serious fixation complications (operative fracture of the femur, cut-out, non-union and later fracture of the femur) nor re-operations (low quality evidence: 45/455 versus 36/455; RR 1.25, 95% CI 0.83 to 1.90).

Two trials (185 participants) provided very low quality evidence of a lack of clinically significant difference in outcome (functional score, mortality, fracture fixation complications and re-operation) between the ACE trochanteric nail and the Gamma nail.

Two trials (200 participants) provided very low quality evidence of a lack of significant difference in outcome (mobility score, pain, fracture fixation complications or re-operations) between the proximal femoral nail antirotation (PFNA) nail and the Gamma 3 nail.

Seven of the nine trials evaluating different comparisons provided very low quality evidence of a lack of significant between-group differences in all of the reported main outcomes for the following comparisons: ACE trochanteric nail versus Gamma 3 nail (112 participants); gliding nail versus Gamma nail (80 participants); Russell-Taylor Recon nail versus long Gamma nail (34 participants, all under 50 years); proximal femoral nail antirotation (PFNA) nail versus Targon PF nail (80 participants); dynamically versus statically locked intramedullary hip screw (IMHS) nail (81 participants); sliding versus non-sliding Gamma 3 nail (80 participants, all under 60 years); and long versus standard PFNA nails (40 participants with reverse oblique fractures).

The other two single comparison trials also provided very low quality evidence of a lack of significant between-group differences in all of the main outcomes with single exceptions. The trial (215 participants) comparing the ENDOVIS nail versus the IMHS nail found low quality evidence of poorer mobility in the ENDOVIS nail group, where more participants in this group were bedridden after their operation (29/105 versus 18/110; RR 1.69, 95% CI 1.00 to 2.85; P = 0.05). The trial (113 participants) comparing the InterTan nail versus the PFNA II nail found very low quality evidence that more PFNA II group participants experienced thigh pain (3/47 versus 12/46; RR: 0.24, 95% CI 0.07 to 0.81).

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