Interpretation of Post-operative Distal Humerus Radiographs After Internal Fixation: Prediction of Later Loss of Fixation

PURPOSE

Stable fixation of distal humerus fracture fragments is necessary for adequate healing and maintenance of reduction. The purpose of this study was to measure the reliability and accuracy of interpretation of postoperative radiographs to predict which implants will loosen or break after operative treatment of bicolumnar distal humerus fractures. We also addressed agreement among surgeons regarding which fracture fixation will loosen or break and the influence of years in independent practice, location of practice, and so forth.

METHODS

A total of 232 orthopedic residents and surgeons from around the world evaluated 24 anteroposterior and lateral radiographs of distal humerus fractures on a Web-based platform to predict which implants would loosen or break. Agreement among observers was measured using the multi-rater kappa measure.

RESULTS

The sensitivity of prediction of failure of fixation of distal humerus fracture on radiographs was 63%, specificity was 53%, positive predictive value was 36%, the negative predictive value was 78%, and accuracy was 56%. There was fair interobserver agreement (κ = 0.27) regarding predictions of failure of fixation of distal humerus fracture on radiographs. Interobserver variability did not change when assessed for the various subgroups.

CONCLUSIONS

When experienced and skilled surgeons perform fixation of type C distal humerus fracture, the immediate postoperative radiograph is not predictive of fixation failure. Reoperation based on the probability of failure might not be advisable.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Fractures of the capitellum in adolescents

Fractures of the capitellum are rare in children. The treatment of these injuries has been controversial. At a major pediatric trauma center, seven capitellar fractures were seen in children between 1988 and 1994. The average age of the children was 14.7 years (range, 11-17). Six of these fractures were type I injuries, with large anterosuperior fragments that required operative reduction and internal fixation in five cases. Internal fixation methods used were K wires in three patients, Herbert screws in one patient, and cannulated screws in one patient. The remaining type I fracture was treated with a closed reduction. The seventh fracture was a type II fracture, treated nonoperatively. Five children did well with their respective treatments, but one required reoperation to remove an exostosis block to flexion. Accurate open reduction and internal fixation for the displaced capitellar fracture in children is an effective treatment to restore normal elbow function.

Seat-belt injuries of the spine in young children

Seat-belt fractures of the lumbar spine in adolescents and adults are well recognised but there are few reports of these injuries in young children. We reviewed all seat-belt injuries in skeletally immature patients (Risser 0), seen at a tertiary referral centre between 1974 and 1991. There were ten cases, eight girls and two boys, with an average age of 7.5 years (3 to 13). Four distinct patterns of injury were observed, most commonly at the L2 to L4 level. Paraplegia, which is thought to be uncommon, occurred in three of our ten cases. Four children had intra-abdominal injuries requiring laparotomy. There was a delay in diagnosis either of the spinal or of the intra-abdominal injury in five cases, although all had contusion of the abdominal wall, the 'seat-belt sign'. Treatment of the fractures was conservative, by bed rest and then hyperextension casts. The incidence of this potentially devastating injury can be reduced by the optimal use of restraints, but there is often a delay in diagnosis. Our classification system may aid in the early detection and evaluation of this injury.

Refractures after forearm plate removal

Debate continues over the need for removal of internal fixation devices. Nowhere has this been more intense than in the area of forearm fractures. Although basic biologic principles would dictate that fixation interferes with bone physiology, clinical experience has taught surgeons that every reoperation has potential complications. We therefore retrospectively reviewed all patients undergoing forearm plate removal during a 5 1/2-year period. There were four subsequent refractures in 63 patients, for an incidence of 6%. Factors that appeared to influence the refracture rate were degree of initial displacement and comminution, physical characteristics of the plate, early removal, and lack of postremoval protection.