[Application of shortened replantation combined with limb lengthening in treatment of severe amputation of middle and distal lower leg].

Objective: To investigate the effectiveness and technical points of shortened replantation combined with limb lengthening in the treatment of severe amputation of middle and distal lower leg.

Methods: Twelve cases of severe amputation of middle and distal lower leg were treated with shortened replantation at the 1st stage and limb lengthening at the 2nd stage between April 2009 and May 2016. There were 9 males and 3 females with an average age of 28 years (range, 16-32 years). The injury causes included traffic accident injury in 4 cases, heavy pound injury in 6 cases, and machine crush injury in 2 cases. The interval from injuries to treatment ranged from 30 minuts to 6 hours (mean, 3 hours and 12 minutes). All of 12 cases, 6 cases were completely amputated in the right middle and distal lower leg, 4 were not completely amputated in the left middle and distal lower leg, and 2 were ankle amputations. The limbs were 4.0-12.5 cm shorter than the contralateral sides, with an average of 7.3 cm. Limb lengthening was performed at 1.5-8.0 months after replantation and the time of extension was 1.7-5.3 months (mean, 3.1 months).

Results: All 12 patients recovered the same lengths of both lower extremities after shortened replantation and limb lengthening. The lengthened segments gained good bone mineralization, bony union was achieved at lengthened segments and broken end of fracture at 7-16 months (mean, 11.3 months). All patients were followed up 6 months to 5 years (mean, 2 years and 5 months). The range of motion of the knee joint were 0-5° (mean, 3°) in hyperextension and 110-140° (mean, 120°) in flexion. Except for 2 cases of ankle arthrodesis, plantar flexion angles were 15-45° (mean, 26°) and dorsiflexion angles were 10-25° (mean, 15°) in the other cases. The plantar sensation was restored to the S 3 + level in 4 cases, S 3 level in 6 cases, and S 2 level in 2 cases. At last follow-up, the affected limb function were excellent in 7 cases, good in 3 cases, fair in 2 cases according to Kofoed functional evaluation criteria.

Conclusion: It expanded indications for replantation of lower limb amputation, reduced the operation difficulty and trauma with shortened replantation combined with limb lengthening in the treatment of severe amputation of middle and distal lower leg.