In lumbosacral plexus injuries can we identify indicators that predict spontaneous recovery or the need for surgical treatment? Results from a clinical study on 72 patients

BACKGROUND Post-traumatic lumbosacral plexus injuries seem to be rare events, spontaneously recovering in high percentage: as surgery is often challenging and results in poor outcome, many Authors have advocated conservative treatment only. Nevertheless surgery should not be ruled out: in invalidating injuries, it can restore basic function in the lower extremities.Therefore, it might be necessary to establish guidelines for the management and the indication to surgery in such cases.This study aims to identify indicators predicting spontaneous recovery or the need for surgery. METHOD The clinical and radiological data of 72 patients with a post-traumatic lumbosacral plexus injury were reviewed. A follow up equal or superior to 3 years is available in 42 cases. RESULTS Lumbosacral plexus injuries mostly occurred during road accidents. The incidence of associated lesions was relevant: bone injuries were found in 85% of patients, internal lesions in 30% and vascular injuries in 8%.Lumbosacral trunk and sacral plexus palsies were the most frequent injury patterns.Root avulsions were revealed in 23% of cases and only in sacral plexus and complete lumbosacral plexus injuries: L5 and S1 were the roots more prone to avulsions.About 70% of cases recovered spontaneously, mostly in 18 months. Spontaneous recovery was the rule in lumbar plexus and lumbosacral trunk injuries (where root avulsions never occurred) or in sacral and complete lumbosacral plexus palsies due to compression injuries.The causative mechanism correlated with the injury pattern, the associated bone injury being often predictive of the severity of the nerve injury.Lumbosacral plexus injuries occurred in car crashes were generally associated with fractures causing compression on the nerves, thus resulting in injuries often amenable of spontaneous recovery.Motorcycle accidents implied high kinetic energy traumas where traction played an important role, as the high percentage of sacroiliac joint separations demonstrated (found in more than 50% of cases and always associated to root avulsions).Loss of sphincteral control and excruciating leg pain were also invariably associated with avulsions. CONCLUSIONS Clinical and radiological data can help to predict the occurrence of spontaneous recovery or the need for surgery in post-traumatic lumbosacral plexus injuries.