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

Complications after proximal abducting ulnar osteotomy and prognostic factors in 66 dogs

Objective

To report complications and prognostic factors in dogs undergoing proximal abducting ulnar osteotomy (PAUL). To evaluate the ability to predict complications on the basis of post‐operative radiographic examination.

Study Design

Retrospective cohort study.

Animals

Sixty‐six dogs.

Methods

Medical records of dogs treated with PAUL between 2014 and 2019 were reviewed for demographics, intraoperative findings, and post‐operative complications. Post‐operative radiographs were reviewed by two masked expert orthopedic surgeons, who were asked to predict the likelihood of major mechanical complications. The prognostic value of variables was tested with univariate and multivariable logistic regression. Inter‐investigator agreement to predict complications was evaluated with two‐by‐two tables and kappa coefficient.

Results

Seventy‐four PAULs in 66 dogs were included. Duration of follow‐up ranged from 12 to 75 months (median: 53 months). Post‐operative complications were documented in 19/74 limbs (16 dogs), including major complications in 13 limbs. These complications consisted mainly of non‐union (six limbs), implant failure (two limbs), and infection (two limbs) requiring revision surgery in nine limbs. Body weight was the only variable associated with an increased risk of post‐operative complications (p = .04). Agreement between expert predictions was low (respectively k = −0.08 and k = 0.11).

Conclusion

Major complications were reported in one fourth of limbs treated with PAUL and were more likely as body weight increased. Suboptimal plate and screw placement or osteotomy reduction on post‐operative radiographs were poorly predictive of complications.

Clinical Significance

Complications are fairly common after PAUL, particularly in heavier dogs, and post‐operative radiographic examination seems unreliable to predict those.

Development of three-dimensional preoperative planning system for the osteosynthesis of distal humerus fractures

BACKGROUND

To reproduce anatomical reduction and appropriate implant placement/choices during osteosynthesis for elbow fractures, we developed a 3D preoperative planning system. To assess the utility of 3D digital preoperative planning for the osteosynthesis of distal humerus fractures, we evaluated the reproducibility of implant reduction shapes and placements in patients with distal humerus fractures.

METHODS

Twelve patients with distal humerus fractures who underwent osteosynthesis using 3D preoperative planning were evaluated. Reduction shapes were evaluated by the angle between the diaphysis axis and a line connecting the vertices of the medial epicondyle and the lateral epicondyle (epicondyle angle), and the angle between the diaphysis axis and the articular surface (joint angle) in the coronal plane, and the distance between the anterior diaphysis and the anterior articular surface in the sagittal plane (anterior distance) based on 3D images of the distal humerus. In addition, the implant positions were evaluated by the positions of the proximal and posterior edge of the plate, and the angle of the plate to the epicondyle line. The reproducibility was evaluated by intra-class correlation coefficients of the parameters between pre- and postoperative images.

RESULTS

The intra-class correlation coefficients were 0.545, 0.802, and 0.372 for the epicondyle angle, joint angle, and anterior distance, respectively. The differences in the measurements between the preoperative plan and postoperative reduction were 2.1 ± 2.1 degrees, 2.3 ± 1.8 degrees, and 2.8 ± 2.0 mm, for the epicondyle angle, joint angle, and anterior distance, respectively. The intra-class correlation coefficients were 0.983, 0.661, and 0.653 for the proximal and posterior plate positions, and the angle to the epicondyle, respectively. The differences in the measurements between the preoperative plan and postoperative reduction were 3.3 ± 2.1 mm, 2.7 ± 1.7 mm and 9.7 ± 9.8 degrees, for the plate positions of proximal and posterior edge, and the angle of the plate to the epicondyle line, respectively. There were significant correlations for the epicondyle angle, joint angle, and plate positions.

CONCLUSIONS

3D preoperative planning for osteosynthesis of distal humerus fracture was reproducible for the reduction shape of the coronal view and the plate positions. It may be helpful for acquiring practical images of osteosynthesis in distal humerus fractures.

LEVEL OF EVIDENCE

Level III, a case-control study.

Effect of trochleocapitellar index on adult patient-reported outcomes after noncomminuted intra-articular distal humeral fractures

BACKGROUND

Anatomic surgical reduction of intra-articular fractures of the distal humerus is important to achieve the best long-term outcomes and prevent post-traumatic arthritis. In this study we compared the radiographic reduction using the trochleocapitellar index. We also correlated the trochleocapitellar index to the functional outcomes next to the comparison of the triceps brachii lifting approach and olecranon osteotomy approach, 2 common approaches for distal humeral fractures.

METHODS

From January 2006 to June 2016, patients with elbow fractures were registered in 4 centers. The trochleocapitellar index, a ratio between the angle of the capitellum and the trochlea to the midline of the distal humerus on anterior-posterior radiographs, was calculated for included patients. Functional outcomes were measured using the Oxford Elbow Score and the Mayo Elbow Performance Score. Bone healing was measured using radiographic union scoring.

RESULTS

There were 86 patients enrolled: 46 in the olecranon osteotomy group and 40 in the triceps lifting group. Functional outcomes and bone healing did not differ between the approaches. Functional results had a medium correlation with the trochleocapitellar index, which did not differ between the 2 approaches (olecranon osteotomy group, κ = 0.56; triceps lifting group, κ = 0.57; P = .7932).

CONCLUSIONS

The trochleocapitellar index has a moderate predictive value on the functional results after 12 months after open reduction and internal fixation of intra-articular distal humeral factures. There is no difference in reduction, as measured by trochlear index and functional outcome scores, between the olecranon osteotomy approach and the triceps brachii lifting approach groups.