The doctor sewed up her leg. 
( ( The doctor ) ( ( ( sewed up ) ( her leg ) ) . ) )
(ROOT (S (NP (DT The) (NN doctor)) (VP (VBD sewed) (PRT (RP up)) (NP (PRP$ her) (NN leg))) (. .)))
The doctor performed surgery on her leg.
( ( The doctor ) ( ( ( performed surgery ) ( on ( her leg ) ) ) . ) )
(ROOT (S (NP (DT The) (NN doctor)) (VP (VBD performed) (NP (NN surgery)) (PP (IN on) (NP (PRP$ her) (NN leg)))) (. .)))