The clinical outcomes measured include elbow ROM, pain scores, elbow carrying angle, the Baumann angle, and bony union. A growth disturbance in the distal humeral physis may affect the carrying angle leading to either a cubitus valgus or varus deformity. Lateral condylar hypertrophy in some cases increases the Baumann angle, causing a cubitus varus deformity, whereas growth arrest reduces the angle resulting in a cubitus valgus deformity. Different scoring or ranking scales such as the Hardacre score incorporates the loss of elbow mobility, changes in the carrying angle, and pain symptoms into an outcomes scoring system (Table 1). Similarly, Dhillon scores consider elbow function, cosmetic appearance, and the carrying angle (Table 2).
Outcomes of nondisplaced lateral condyle fractures treated with immobilization are favorably reported for fractures that remain nondisplaced. Nondisplaced fractures typically achieve bony union, but up to 14.9% of fractures will further displace requiring surgical intervention.[3,14,15] Subsequent displacement is unpredictable and occurs because of the constant pull of the common wrist extensors and the supinator muscles at the fragmented fracture piece and can additionally be worsened by radial head abutment at the fracture site. Patients should be radiographically surveyed weekly for 2 to 3 weeks after casting to identify fractures with worsening displacement.
Closed Reduction and Percutaneous Pinning
Lateral condyle fractures treated with CRPP usually achieve bony union with limited long-term sequelae. Silva and Cooper reported satisfactory outcomes in 89.3% of patients treated with CRPP. Despite the occurrence of lateral spurring and pin-site infections, patients regained 99% of the mean arc of elbow motion compared with the contralateral elbow by their last follow-up visit. The authors reported an overall infection rate of 1.8% in patients treated with ORIF and 3.6% in those treated with CRPP.
Several authors have compared outcomes between fixation techniques and buried versus exposed percutaneous fixation. Exposed wires are more cost effective because they can be removed in an outpatient setting, and buried implant can erode through the skin requiring subsequent unplanned surgery.[19,27] Stein et al reported that patients treated with a closed reduction and percutaneous 4.5-mm cannulated lag screw had higher Hardacre scores compared with patients treated with percutaneous pinning, 89% versus 59%, respectively. Percutaneous lag screw fixation allows for greater compression across the fracture site, resulting in higher rates of successful fracture union. However, lag screw fixation increases patient morbidity because it requires an additional surgical procedure to remove the screw to avoid restriction of physeal growth.
Leonidou et al reported excellent outcomes in 105 patients treated with ORIF using Kirschner wire fixation for all fractures displaced >2 mm. Ninety-six percent of patients achieved excellent Hardacre scores and 4% achieved good scores. All fractures went on to bony union and patients achieved normal elbow ROM. Li and Xu compared cannulated screw and Kirschner wire fixation and determined no major clinical differences, but more patients in the Kirschner wire fixation group had a superficial infection, lateral prominence, and limitations with elbow extension. Gilbert et al compared cannulated screw and Kirschner wire fixation when treating acutely displaced fractures and reported that patients treated with cannulated screw fixation had a shorter time to union, decreased time in their cast postoperatively, greater median arc of motion, and fewer nonunions and delayed unions; 16.3% of patients treated with Kirschner wires had delayed or no bony union compared with 2.4% in the cannulated screw fixation group. The authors attributed the difference to the increase in compression forces across the fracture site with cannulated screw fixation. Cannulated screw fixation has also been associated with increased biomechanical stability, faster improvement in elbow ROM and fewer complications such as infection, nonunion, and lateral overgrowth.[21,30] However, there is still concern related to the risks of anesthesia because patients required a second surgery to remove the implant. There has also been reported use of bioresorbable fixation. Takada et al treated eight patients with an ORIF using two threaded f-u-HA/PLLA bioresorbable pins. All patients achieved bony union, an average Baumann angle of 14°, and no implant-related complications.
J Am Acad Orthop Surg. 2020;28(1):e9-e19. © 2020 American Academy of Orthopaedic Surgeons