Hip operation – Nerve lesion not negligent: Susan Moore v Plymouth Hospitals NHS Trust (High Court, 29 September 2016 – Mr Recorder Moger QC)

This was undertaken by minimally invasive surgery (MIS) using the direct anterior approach. Mr Fekry had played a large part in the introduction of this procedure by the trust. Its use was approved in August 2008. The operation involves a relatively short incision, followed by the placing of four retractors to pull aside the soft tissues obscuring access to the operation site. They are placed opposite one another and retractor 4 will normally be in place for about 30min in an uncomplicated operation. It is a recognised risk of hip replacement surgery that an injury may be sustained by the patient’s FN during the course of the operation. However, the incidence of FN injury during a total hip replacement procedure is rare. Published literature gives a maximum of 2.4% of cases, and in many studies the figure is below 0.1%. A 2008 paper by Brown and others states that FN injuries result primarily from improper placement of retractor 4, since its tip is placed near the FN. The respective experts agreed that four retractors must be used during this operation and that the process of retracting soft tissues will inevitably impact upon the FN. Careful management of the retractors involves the surgeon ensuring that only the force necessary to enable access to the operation site is employed, and that the potential impact on the FN should be relieved by intermittent breaks in applying traction. It was also agreed that a further possible mechanism of injury was that if the point of retractor 4 was not placed directly onto the bony structure of the pelvic rim, but rather positioned so as to trap or impale soft tissue containing the nerve, a direct injury will be caused.