We retrospectively reviewed 89 consecutive patients
(45 men and 44 women) with a mean age at the time of injury of 58
years (18 to 97) who had undergone external fixation after sustaining
a unilateral fracture of the distal humerus. Our objectives were
to determine the incidence of heterotopic ossification (HO); identify
risk factors associated with the development of HO; and characterise
the location, severity and resultant functional impairment attributable
to the presence of HO. . HO was identified in 37 elbows (42%), mostly around the humerus
and along the course of the medial collateral ligament. HO was hazy
immature in five elbows (13.5%), mature discrete in 20 (54%), extensive
mature in 10 (27%), and complete bone bridges were present in two
elbows (5.5%). Mild functional impairment occurred in eight patients,
moderate in 27 and severe in two. HO was associated with less extension
(p = 0.032) and less overall flexion-to-extension movement (p =
0.022); the flexion-to-extension arc was <
100º in 21 elbows
(57%) with HO compared with 18 elbows (35%) without HO (p = 0.03).
HO was removed surgically in seven elbows. . The development of HO was significantly associated with sustaining
a head injury (p = 0.015), delayed internal fixation (p = 0.027),
the method of fracture fixation (p = 0.039) and the use of bone
graft or substitute (p = 0.02).HO continues to be a substantial
complication after internal fixation for distal
