Membership information 1800 932 916
Medicolegal advice 1800 936 077

Sciatic nerve injury but no negligence

19 July 2018
By Dr Ellen Welch, GP

Mrs D, a 68-year-old housewife, had consulted her GP Dr L regularly over a number of years for various minor musculoskeletal complaints. She complained intermittently of low back pain for which she typically received an intramuscular injection of diclofenac. Over a five-year period, it was documented that she had received five intramuscular injections from Dr L without any problems.

On one occasion, Mrs D visited Dr L complaining of severe dizziness, vomiting and headache. Dr L diagnosed her with likely vestibular neuronitis and offered her an intramuscular injection of dimenhydrinate to improve her symptoms. Dr L carried out the procedure as he had many times before, by asking Mrs D to lie in the left lateral position. He injected 1ml of the antihistamine into the dorsogluteal site at the upper, outer quadrant of her right buttock. She did not complain of any excessive pain following the injection.

Almost two weeks later, Mrs D returned to see Dr L, complaining of swelling at the injection site, associated with pain and numbness over her right leg. She reported that these symptoms had started soon after leaving Dr L’s clinic, and she had continued to experience pain and numbness extending from the injection site, all the way down the lateral aspect of her right leg to her toes. Dr L explained that the pain could be caused by chemical irritation from the injected medication, and he prescribed anti-inflammatories.

Mrs D continued to experience these symptoms and consulted with Dr L several times. A month later, she decided to seek a second opinion from another GP, Dr U, who raised the possibility that she had sustained an injury of the right sciatic nerve due to the injection she had received. He referred her to see Dr P, an orthopaedic surgeon, who reviewed her in the outpatient clinic a month later. Dr P examined Mrs D and documented good range of motion in her hip, with no muscle wasting, normal power and normal lower limb reflexes. Diffuse numbness was found from the groin to the toes, which did not correspond to the distribution of any known spinal nerve root or peripheral nerve. Dr P reported that in his opinion, her condition was unlikely to be caused by any injury to the sciatic nerve, and she was treated for lumbar spondylosis.

Mrs D continued to consult with Dr L for another four months with persisting symptoms, and the clinical findings remained unchanged. He referred her for a neurological opinion, documenting in his referral notes that she was experiencing “numbness after injection three months ago with upper thigh muscle atrophy”.

Mrs D made a claim against Dr L, alleging iatrogenic nerve damage.
Expert opinion
As part of the neurologist’s investigation, Mrs D underwent an electrophysiological study, which showed a slight reduced recruitment ratio over her right inferior gluteal nerve suggestive of chronic denervation.
Expert witnesses on both sides agreed that the results of this study could not fully account for Mrs D’s clinical symptoms, since the inferior gluteal nerve is a purely motor nerve and would therefore not cause sensory symptoms. Her diffuse numbness did not correspond to the distribution of any known spinal or peripheral nerve.

Concerns were raised by the expert witnesses regarding Dr L’s documentation of the case. After his initial consultations with Mrs D, Dr L continued to consult with her on several occasions, but did not write down any of his physical examination findings. He documented that she complained of ‘muscle atrophy’, but this was not confirmed on examination. Dr L stated that he wrote the words ‘muscle atrophy’ because these were the words Mrs D had used, and the problem she complained of, but he himself did not find any objective evidence of atrophy.

However, because neither the distribution nor the timing of the onset of Mrs D’s symptoms fit the typical distribution for sciatic nerve injury, and there was no other documented neurological abnormality, the claim against Dr L was discontinued.
Learning points
  • The dorsogluteal site or the ‘upper, outer, quadrant’ is the traditional IM injection site of choice, but it has been associated with injury to the sciatic nerve.  The ventrogluteal region is now preferred as the first choice injection site despite having a shallower muscle depth as it is farther from neurovascular structures.   
  • Good clinical documentation, as always, is an essential part of the consultation, and should a patient take legal action, a defence will be built on the clinical notes. It is easy to become relaxed about documentation with patients who present often and/or are well known to the doctor, but examination findings, including significant negatives, should always be recorded.
  • Mishra P, Stringer MD, Sciatic nerve injury from intramuscular injection: a persistent and global problem, The International Journal of Clinical Practice 64, 11, 1573-1579 (2010)
    Greenway K, Using the ventrogluteal site for intramuscular injection, Nursing Standard 18, 25, 39-42 (2004)
  • Coskum, H, Kilic C, Senture C, The evaluation of dorsogluteal and ventrogluteal injection sites: a cadaver study, Journal of Clinical Nursing 25, 1112-1119 (2016)