This blog was authored by Jason Hudson, Trainee Associate.
In Van Wyk v Duze the court focused on whether the claimant’s sciatic nerve injury during a total hip replacement (THR) was caused by the defendant doctor’s negligence. The claimant alleged that the incorrect and careless placement of a surgical retractor caused the injury.
The court reaffirmed that in civil cases, the burden of proof is based on a balance of probabilities rather than scientific certainty. An analysis of the cogency and underlying reasoning for the opinions of the experts suffices. Since there was no direct evidence linking the retractor to the injury and given that many similar injuries occur without a clear cause, the court found that the claimant had not proven negligence.
Experts for each side had conflicting views. The claimant’s expert believed the most likely cause was incorrect retractor placement, arguing that the sciatic nerve’s proximity to the hip joint made it vulnerable to damage. The defendant’s expert disagreed, suggesting that indirect compression of the nerve, due to anatomical variations or leg rotation during surgery, was a more probable explanation. He also pointed out that 50% of sciatic nerve injuries after THR have no known cause.
The court emphasized that expert opinions must be logically reasoned and defensible rather than simply accepted at face value. When experts disagree, the court must carefully evaluate their reasoning and justify its preference rather than choosing arbitrarily. In this case, the court found the defendant’s expert more persuasive because his opinion was better supported by medical literature and provided a logical explanation for why the injury did not fit the typical pattern of retractor-related nerve damage.
This case highlights the crucial role of expert evidence in medical negligence claims and the importance of courts critically assessing the logic and literature behind expert opinions rather than simply choosing one side over the other.