Sciatic nerve palsies are rare but potentially devastating complications, accounting for more than 90% of neurologic injuries following total hip replacement. A systematic literature screening was carried out searching papers evaluating an exclusive population of postarthroplasty sciatic nerve palsies to ascertain (1) the influence of limb lengthening itself on sciatic nerve palsy, (2) the most important risk factors, (3) the long-term prognosis, and (4) the outcomes of different treatments. Fourteen manuscripts were finally included. The wide prevalence of retrospective case series decreased the global methodological quality of the retrieved papers. A hazardous lengthening threshold cannot be surely identified. Developmental dysplasia of the hip and previous hip surgeries are the most frequently recognized risk factors. Rate of full nerve function restoration approximates two-thirds of the cases, independently of the extent of initial neural damage. Poor evidences are available about the best treatment strategy. Well-structured multicentric prospective comparative studies are needed to substantiate or contrast the finding of this review. Anyway, since the onset of palsies is probably due to a combination of individual factors, risk of nerve damage and potential for nerve recovery should be evaluated on an individual basis.