Lateral spurring (overgrowth) after pediatric lateral condyle fractures.

BACKGROUND:
Bony overgrowth over the lateral condyle, or "lateral spurring," is commonly identified after lateral condyle fractures of the humerus in children. Despite its frequent recognition, no prior study has defined the phenomenon, established an incidence rate, explored a correlation with any fracture or treatment characteristics, nor assessed whether it is of functional significance.

METHODS:
We retrospectively analyzed information on 212 consecutive lateral condyle fractures in children. Spurring was defined as an overgrowth of bone over the lateral aspect of the lateral condyle resulting in an irregularity of the metaphyseal flare. The magnitude of the spurring was classified by measuring the increase in maximum interepicondylar width of the distal humerus on the latest follow-up radiograph.

RESULTS:
Of the 212 fractures, 55% were treated with cast immobilization, 11% with closed reduction and percutaneous pinning, and 34% with open reduction and internal fixation. Of all fractures, 73% developed a lateral spur. Of those, 43% had a mild spur, 38% a moderate spur, and 19% a severe spur. Fractures that developed a spur had a mean initial displacement of 3.3 mm, as compared with 1.1 mm in those that did not develop spurring (P< 0.0001). The amount of initial displacement was higher for fractures that developed mild (2.4 mm, P=0004), moderate (3.6 mm, P< 0.00001), and severe (4.9 mm, P< 0.00001) spurs, as compared with fractures with no spur. At the latest follow-up, patients that developed lateral spurring had a mean relative arc of motion of 93.7% of the normal contralateral elbow, whereas patients without a spur had a relative range of motion of 94.3% (P=0.4).

CONCLUSIONS:
Lateral spurring is an extremely common sequela of lateral humeral condyle fractures in children. The development of a spur correlates with initial displacement and surgical treatment. The size of the spur is associated with the amount of initial fracture displacement. Despite concerns from patients, families, and physicians alike, neither the presence nor the size of the lateral spur seems to influence the final outcome.

LEVEL OF EVIDENCE:
Level II--retrospective study.