Phase I shortening and replantation-Phase II limb lengthening treatment for segmental mangled injury of the lower extremities

Objective To investigate the clinical efficacy and complication rates of treating lower limb segmental mangled injuries using a two-stage approach：initial shortening and replantation followed by secondary limb lengthening. Methods A retrospective analysis was conducted on the clinical data of 12 patients with lower limb segmental mangled injuries admitted to the General Hospital of the Ordnance Industry Group from January 2018 to June 2023. All patients were treated with initial shortening and replantation，followed by secondary limb lengthening after soft tissue recovery. Postoperative observation focused on limb survival and complications，with regular follow-up. At the final follow-up，distal sensation was assessed using sensory recovery grading，motor function of the affected limb was evaluated by muscle strength grading，and the Association for the Study and Application of the Method of Ilizarov（ASAMI） scoring system was used to evaluate bone healing and limb function. Results All 12 patients were successfully treated，with a follow-up period ranging from 20 to 36 months. Limb salvage was successful in all cases after the initial shortening and replantation. Primary wound healing was achieved in 8 cases,3 cases had partial skin edge necrosis with superficial infection,1 case experienced skin necrosis and bone exposure. Limb shortening was 4.0-9.0 cm，with an average of 6.5 cm. The duration of external fixation during the secondary lengthening phase ranged from 0.5 to 1.5 years. Complications included pin tract infection in 5 cases（no deep infections），nonunion in 3 cases，and Achilles tendon adhesion in 2 cases. At the final follow-up，distal sensory recovery was graded as S4 in 4 cases and S3 in 8 cases，with muscle strength of the affected limb graded as M4 in 5 cases and M5 in 7 cases. Bone healing was rated as excellent in 10 cases and good in 2 cases. Limb function was rated as excellent in 8 cases and good in 4 cases. Conclusion The two- stage approach involving initial shortening and replantation followed by secondary limb lengthening demonstrates favorable clinical outcomes for treating lower limb segmental mangled injuries. This method effectively reduces the amputation rate while minimizing donor site morbidity and related complications typically associated with procedures such as skin grafting，flap transfers，and bone grafting.