Medial and lateral crossed pinning versus lateral pinning for supracondylar fractures of the humerus in children: decision analysis.

BACKGROUND

The choice of pinning techniques in supracondylar fractures of the humerus in children has been a debate regarding its fixation stability and risk of iatrogenic ulnar nerve palsy. This study was performed to determine as to which fixating method (medial and lateral crossed pinning vs. lateral pinning) is better for the displaced supracondylar fractures using a decision analysis tool in terms of function.

METHODS

A decision analysis model was designed containing the probability of iatrogenic ulnar nerve palsy and malunion caused by unstable fixation for each of lateral pinning and medial and lateral crossed pinning techniques. The final outcome was function adjusted life year and used as a utility in the decision tree, where function was evaluated using the McBride disability evaluation. The probabilities of all cases were obtained by literature review and assumptions. A roll back tool was used to determine the better pinning technique, and sensitivity analysis was performed to compensate for the uncertainty of the model.

RESULTS

Overall, our decision model favored the lateral pinning technique over the medial and lateral crossed pinning with the utilities of 99.6 and 99.3 in terms of function adjusted life year. One-way sensitivity analysis showed that the threshold rate of iatrogenic ulnar nerve injury as a complication after medial and lateral crossed pinning was 0.7%, below which the model favored medial and lateral crossed pinning over lateral pinning. The decision model was found to be sensitive to the percentage of permanent ulnar nerve palsy after medial and lateral crossed pinning. Two-way sensitivity analysis showed that the lateral pinning technique was more beneficial than the medial and lateral crossed pinning technique.

CONCLUSIONS

In our decision analysis model, the lateral pinning technique was found to be more beneficial than the medial and lateral crossed pinning technique for supracondylar fractures of the humerus in children, on the basis of current evidences. However, the results were sensitive to the data of ulnar nerve injury. Avoiding the worst clinical scenario (permanent ulnar nerve palsy) might be more important and affordable than obtaining favorable clinical results (stable fixation) at the potential cost of disastrous complications.

LEVEL OF EVIDENCE: Level III.