Is reconstruction nailing of all femoral shaft fractures cost effective? A decision analysis.

OBJECTIVES

Femoral shaft fractures are usually treated with anterograde or retrograde nails that typically do not provide femoral neck fixation. Ipsilateral femoral neck fractures occur with 2.5%-10% of femoral shaft fractures; 19%-55% of associated femoral neck fractures are missed with plain films and 5%-22% with computed tomography (CT). This study was performed to determine if routine reconstruction nailing of all femoral shaft fractures with or without occult femoral neck fractures is cost effective.

METHODS

A decision tree model examined the cost effectiveness of reconstruction nailing over standard intramedullary nailing for all femoral shaft fractures in which an associated femoral neck fracture was not identified on plain radiographs. As a base model, we assumed that 5% of shaft fractures had an ipsilateral femoral neck fracture, and 37% were missed and required further surgery. We assigned a small morbidity and additional cost ($680) for the use of a reconstruction nail and 2 screws. Model inputs including costs, clinical outcome probabilities, and health utilities were derived from the literature, estimated from institutional data, or assumed by the authors. Sensitivity analyses evaluated the effect of the rate of associated femoral neck fracture, the rate of missed femoral neck fracture, the complication rate of reconstruction screws, the cost of the extra reconstruction screws, and the utilities of each outcome on the incremental cost effectiveness (ICER) of both strategies. Current practice in cost-effectiveness analysis uses a threshold of $100,000 per quality-adjusted life year gained as cost effective. A secondary analysis of the use CT scans to reduce missed femoral neck fractures was also performed.

RESULTS

The base model showed that the placement of reconstruction nails in all isolated femur fractures was not cost effective. Sensitivity analysis demonstrated that the ICER was most sensitive to the cost of the reconstruction nail, hemiarthroplasty, and a missed femoral neck fracture. The ICER was affected by the rate of femoral neck fracture and the rate of missed femoral neck fracture. If the rate of missed femoral neck fractures was >38%, then reconstruction nailing was a cost-effective strategy. If the probability of an ipsilateral femoral neck fracture was >7%, then reconstruction nailing was cost effective. Protocolized CT scans had an ICER >$100,000. If the additional cost of the reconstruction nails was <$650, then it was cost effective to perform reconstruction nailing for all femoral shaft fractures.

CONCLUSIONS

Reconstruction nailing of femoral shaft fractures can be a cost-effective method to reduce the risks and morbidity of missed femoral neck fractures if the incremental implant costs are <$650. Routine reconstruction nailing is cost effective if the rate of associated femoral neck fracture is >7% or the rate of missed femoral neck fracture is >38%. CT scans are not a cost-effective strategy to reduce the risk and morbidity of missed femoral neck fractures if the cost is >$243. Weaknesses of this study include the reliance on low-powered studies and on estimations of some utilities and costs. To prevent the morbidity of missed or occult femoral neck fractures, the use of reconstruction nails for femoral shaft fractures is cost effective when the incremental costs of implants are <$650.

LEVEL OF EVIDENCE

Economic Level II. See Instructions for Authors for a complete description of levels of evidence.