May (A Child) v Lancashire Teaching Hospitals NHS Trust

A medical negligence assessment must be made by reference to the circumstances of the particular procedure and the defendant practitioner’s skill and experience. A practice may be acceptable for some surgeons yet fall below the required standard for another surgeon who recognises the need for additional safeguards. In complex spinal surgery, the absence of both-plane imaging and spinal cord monitoring may amount to negligence where the surgeon faces an identified risk of screw misplacement and monitoring is reasonably available. Causation is established where those failures probably caused, or would probably have detected and permitted treatment of, the injury.

The claimant, a child, became paraplegic during corrective surgery for severe idiopathic thoracic scoliosis at the defendant’s hospital. The parties agreed that the paraplegia occurred during the operation and that the dura was pierced, causing a cerebrospinal-fluid leak. The principal factual dispute was whether the injury resulted from a misplaced pedicle screw at T6 or from manipulation of the spine.

The claimant alleged that the surgeon was negligent in failing to use anterior/posterior imaging, in proceeding without spinal cord monitoring, and in failing to conduct earlier wake-up tests. The central questions were whether the operation was performed negligently and, if so, whether the negligence caused the paraplegia.

1. Causation. On the balance of probabilities, the claimant’s spinal cord was compressed by a pedicle screw penetrating the dura at T6. The court considered the use of the Mehdian method, the relatively gentle manipulation, the absence of convincing evidence of manipulation injury, the difficulty of placing a screw at T6, and the relationship between the cerebrospinal-fluid leak and the spinal injury. The alternative theory of injury by manipulation was rejected on the evidence (paras [74]-[75]).
2. Applicable negligence test. The parties agreed that the Bolam v Friern Hospital Management Committee test applied: a practitioner is not negligent when acting in accordance with a practice accepted as proper by a responsible body of skilled practitioners. The assessment nevertheless depends upon the practitioner’s own skill and experience (para [76]).
3. Bi-planar imaging. Lateral imaging showed the depth of the screw but not its lateral position. The surgeon recognised that placement at T6 and above was increasingly difficult and ordinarily used imaging during placement. In circumstances where spinal cord monitoring was unavailable, failure to use both lateral and anterior/posterior imaging during preparation for and insertion of the T6 screw fell below the reasonable standard of care (paras [79]-[85]).
4. Spinal cord monitoring. Monitoring provided continuous assessment of spinal function and enabled investigation if compromise was detected. It was available and used at most, if not all, other centres. Applying the agreed test, the Trust was negligent in failing to provide monitoring for this operation; the surgeon would have used it if provided (paras [86]-[90]).
5. Wake-up tests. The claimant did not establish that the surgeon was negligent in failing to plan multiple earlier wake-up tests. The evidence did not demonstrate that such testing was an accepted or practicable practice (paras [91]-[93]).
6. Final determination. The failures to use bi-planar imaging and to provide spinal cord monitoring together caused the claimant’s paraplegia. Imaging would probably have prevented the screw’s misplacement, while monitoring could probably have detected cord compression in time for intervention (para [94]). The claimant established negligence and causation (para [95]).

Not stated in the judgment.