Proximal Ulna Osteotomy for Complex Fractures of the Distal Humerus: A 3-Dimensional Laser Analysis and Comparison With Olecranon Osteotomy

Surgical Outcomes of Olecranon Osteotomy Approach Combined With Submerged Kirschner Wires and Plate Fixation for Duckerley IIIB Distal Humeral Coronal Shear Fractures

OBJECTIVE

Duckerley type IIIB distal humerus fractures are rare and complex injuries that pose significant challenges in both diagnosis and treatment. Currently, no consensus exists on the fixation method, with existing approaches often struggling to handle small fragments and associated with issues like elbow instability. The purpose of this study is to evaluate the surgical outcomes of submerged Kirschner wires combined with plate or submerged screw fixation technique for the treatment of Duckerley type IIIB distal humerus fractures.

METHODS

A retrospective analysis was conducted on 10 patients with Duckerley type IIIB distal humerus fractures who were treated at our hospital from February 2017 to April 2021. The treatment involved applying buried Kirschner wires combined with microplate or buried screw fixation technique through the olecranon osteotomy approach. The study included six males and four females, with a mean age of 51.4 ± 15.34 years (ranging from 22 to 69 years). During the follow-up, the elbow range of motion, Mayo Elbow Performance Score (MEPS), American Shoulder and Elbow Surgeons (ASES) score, and complications were assessed.

RESULTS

All 10 patients received regular clinical and imaging follow-up for a mean of 39.7 ± 8.8 months (range: 25-50 months). Postoperative incision healing was good for all patients, and no neurovascular injuries were noted. Two patients developed elbow pain. At the last follow-up before the internal fixation removal operation (9.6 ± 1.9 months), X-ray and CT findings confirmed bony healing, and no internal fixation loosening and breakage occurred in any of the patients, except for one case in which there was displacement of the Kirschner wires. The mean range of motion of the elbow before the internal fixation removal operation was extension 15.0° ± 21.6°, flexion 129.5° ± 28.1°, pronation 83.0° ± 9.2°, and supination 81.5° ± 8.0°. The MEPS score was 83.0 ± 8.3, and the ASES was 83.6 ± 7.8. At the last follow-up, the mean range of motion of the elbow was extension 10.0° ± 21.9°, flexion 133.5° ± 16.0°, pronation 88.0° ± 11.2°, and supination 85.0° ± 9.5°. The MEPS score was 84.6 ± 7.6, and the ASES was 84.1 ± 7.4.

CONCLUSIONS

The treatment of Duckerley type IIIB low distal humerus fractures using submerged Kirschner wires combined with plate or submerged screw fixation technique has satisfactory advantages in terms of fracture reduction, maintenance of the position of internal fixation, and postoperative recovery.

Morphological map of the proximal ulna bare area: a computer-assisted anatomical study in relation to olecranon osteotomy

BACKGROUND

The bare area is defined as a transverse region within the trochlear notch, serving as an optimal entry point for olecranon osteotomy due to the absence of articular cartilage coverage. However, there is limited research on the morphology and location of the bare area, and there is a lack of intuitive visual description. Thus, the purpose of this study is to delineate anatomical features of the bare area and visualize its morphology and refine the olecranon osteotomy approach.

METHODS

Thirty-six cadaveric elbow joints (comprising 18 pairs) were meticulously dissected. Measurements encompassed the lateral (radial side) and medial (ulnar side) widths, proximal and distal lengths, and the distance from the corresponding dorsal cortical point of the bare area to the triceps insertion. Post-dissection, the humeral ulnar joint was realigned, followed by randomized transverse or chevron osteotomy. Subsequent computed tomography scans were conducted pre-osteotomy and post-osteotomy to delineate the shape of the bare area and osteotomy fracture line, facilitating the generation of superimposed and heat maps for visualization.

RESULTS

The bare area was present in all specimens, exhibiting a lateral (radial) width of 7.09 ± 4.86 mm, a medial (ulnar) width of 12.08 ± 3.66 mm, a proximal length of 15.70 ± 8.06 mm, and a distal length of 16.49 ± 7.06 mm. The distance from the triceps insertion to the corresponding dorsal cortical point of the bare area averaged 18.12 ± 3.21 mm. Notably, considerable variability was observed in both the position and shape of the bare area. Visualization through superimposed and heat maps revealed a bow-tie configuration, with the medial side wider than the lateral side, situated at the narrowest segment of the proximal ulna in the coronal plane, analogous to its waist. The superimposed map of fracture lines reveals that the fracture lines from transverse osteotomies are more concentrated than those from chevron osteotomies.

CONCLUSION

The position and shape of the bare area demonstrates notable diversity, manifesting not as a strictly transverse shape nor a consistently contiguous region. Rather, the bare area generally assumes a bow-tie configuration, rendering the conventional definition of its width along the sagittal plane inadequate and potentially misleading. Based on the typical position of the bare area, we can propose that when the precise morphology and position of a patient's bare area are unknown, targeting this region via an osteotomy from the proximal ulna's narrowest segment provides an effective approach.

Biomechanics of plate fixation following traditional olecranon osteotomy versus novel proximal ulna osteotomy for visualizing a distal humerus injury

After a distal humeral injury, olecranon osteotomy (OO) is a traditional way to visualize the distal humerus for performing fracture fixation. In contrast, the current authors previously showed that novel proximal ulna osteotomy (PUO) allows better access to the distal humerus without ligamentous compromise. Therefore, this study biomechanically compared plating repair following OO versus PUO. The left or right ulna from eight matched pairs of human cadaveric elbows were randomly assigned to receive OO or PUO and repaired using pre-contoured titanium plates. Destructive and non-destructive mechanical tests were performed to assess stability. Mechanical tests on OO versus PUO groups yielded average results for ulna cantilever bending stiffness at a 90° elbow angle (29.6 vs 30.5 N/mm, p = 0.742), triceps tendon pull stiffness at a 90° elbow angle (28.2 vs 24.4 N/mm, p = 0.051), triceps tendon pull stiffness at a 110° elbow angle (61.9 vs 59.5 N/mm, p = 0.640), and triceps tendon pull failure load at a 110° elbow angle (1070.1 vs 1359.7 N, p = 0.078). OO and PUO elbows had similar failure mechanisms, namely, tendon tear or avulsion from the ulna with or without some fracture of the proximal bone fragment, or complete avulsion of the proximal bone fragment from the plate. The similar biomechanical stability (i.e., no statistical difference for 4 of 4 mechanical measurements) and failure mechanisms of OO and PUO plated elbows support the clinical use of PUO as a possible alternative to OO for visualizing the distal humerus.

Controversies in the Management of Bicolumnar Fractures of the Distal Humerus

Bicolumnar fractures of the distal humerus pose numerous treatment challenges for upper-extremity surgeons. Although open reduction and internal fixation demonstrates advantages compared with nonsurgical treatment, restoration of osseous anatomy can be difficult, particularly for comminuted, intra-articular fractures. Despite well-recognized complications, total elbow arthroplasty remains an option for elderly patients with fractures not amenable to fixation. Although indications remain controversial, distal humerus hemiarthroplasty has emerged as a potential alternative to total elbow arthroplasty in carefully selected patients with nonreconstructable fractures. Numerous controversies remain with respect to the management decisions for these complex injuries, including the optimal surgical approach, management of the ulnar nerve, and ideal fixation constructs for open reduction internal fixation. Our purpose is to review the management of bicolumnar distal humerus fractures in adult patients and discuss current controversies related to treatment.