medwireNews: Preliminary research suggests that neurolysis can significantly reduce neuropathic pain in patients who develop sciatic nerve palsy after total hip replacement (THR).
Patients who underwent exploration and neurolysis achieved a significant decrease in their visual analog scale (VAS) pain score, from an average of 7.59 before surgery to 3.77 after the procedure, report Michael Fox and co-workers, from the Royal National Orthopaedic Hospital, in Stanmore, UK.
"Although we had no conservatively-treated control group of patients for comparisons, it is felt that there is sufficient evidence to suggest that for the majority of patients there is benefit in performing neurolysis and even doing so quite late (up to 40 months) after THR," they write in The Bone & Joint Journal.
"It encourages us to advocate this form of treatment over conservative management, especially as we made no patients worse and the majority were significantly improved."
Overall, 56 patients aged an average of 61.2 years were treated with neurolysis between September 1999 and September 2010.
The patients sustained sciatic nerve palsy after primary THR (n=56), revision THR (n=5), or hip resurfacing (n=5). Palsy was attributed to a range of factors, including scar tissue, traction, sharp injury, hematoma, cement/bone graft, impingement, or a sutured nerve in 34 patients. Seventeen patients had normal nerve appearance.
Forty patients experienced a significant VAS pain score reduction an average of 3.6 months after surgery. None of the patients experienced greater pain after neurolysis but 10 (18%) patients had no improvement.
"We presume that this represents a cohort of patients who sustained significant established axonal injury that is refractory to decompression," Fox et al comment.
Neurolysis was carried out an average of 8.75 months after THR; the time to sciatic nerve surgery did not significantly predict patient outcome, say the researchers.
"This suggests there may be benefit from exploring the nerve even when presentation is significantly delayed," the team concludes.