Coronoid process reconstruction with a distal clavicle autograft: an in silico analysis of fitting accuracy

The Free Distal Clavicle Osteochondral Flap: Cadaveric Dissection and Case Report to Introduce a Novel Technique

Vascularized osteochondral flap reconstruction is an innovation with several potential benefits, but there are limited described autologous donor site options. This study explores the distal clavicle as a viable donor site for vascularized free osteochondral tissue transfer. Cadaveric dissection was performed in which a 39-year-old male with a comminuted fracture of the right distal humerus underwent open reduction and internal fixation. The patient later presented with avascular necrosis of the lateral column of the distal humerus and right trochlea and underwent reconstruction of the distal humerus with iliac crest bone graft and vascularized free osteochondral transfer of the distal clavicle. The distal clavicle was harvested with its periosteum and a small muscle cuff based on the acromial branch of the thoracoacromial system. The authors report a novel technique for distal clavicle osteochondral flap harvest and present a case in which the technique was used successfully in complex elbow reconstruction.

Using External Joint Stabilizer - Elbow (EJS-E) for treating elbow instability-biomechanical assessment and clinical outcomes

BACKGROUND

This study aimed to evaluate the outcome of using an External Joint Stabilizer - Elbow (EJS-E) for persistent elbow instability based on biomechanical experiments and analysis of clinical results.

METHODS

An EJS-E was used in 17 elbow instability patients. The median follow-up was 26 months (range, 12-42 months). We evaluated the flexion-extension and pronation-supination movement arcs, visual analog scale (VAS) score, Mayo Elbow Performance Score (MEPS), Broberg and Morrey classification system, and occurrence of complications in these patients. Moreover, construct stiffness and maximum strength tests were performed to evaluate the strength of the fixation techniques.

RESULTS

The final median range of the extension-to-flexion and pronation-to-supination arc of the elbow was 135° (range, 110°-150°) and 165° (range, 125°-180°), respectively. The VAS pain scores were > 3 in two patients. The median MEPS was 90 (range, 80-100 points). Five patients showed signs of grade I post-traumatic osteoarthritis according to the Broberg and Morrey radiographic classification system, while grade II changes were observed in three patients. Complications included axis pin loosening with pin-tract infection in two patients, transient ulnar nerve symptoms in two patients, heterotopic ossification in two patients, and suture anchors infection in one patient. Based on the biomechanical testing results, the EJS-E exhibited higher stiffness and resisting force in varus loading. It was 0.5 (N/mm) stiffer and 1.8 (N·m) stronger than the internal joint stabilizer (IJS) by difference of medians (p < 0.05).

CONCLUSIONS

Biomechanical and clinical outcomes show that EJS-E via the posterior approach can restore mobility and stability in all patients, thus serving as a valuable alternative option for the treatment of persistent instability of the elbow.

Reconstruction of the coronoid process with the olecranon tip for chronic elbow dislocation in children: A rare case report and literature review

The coronoid process of the ulna, as a key part of the elbow joint, plays an important role in maintaining elbow joint stability. Reconstruction of the coronoid process is necessary in both acute and chronic coronoid defects to restore elbow stability and avoid early joint degeneration. The olecranon tip may be a useful autologous osteochondral graft for reconstructing the same shape of the ulna coronoid process. The purpose of this report was to verify if reconstruction of the coronoid process with the olecranon tip can restore elbow stability and kinematics. Here, we report a 13-year-old boy who had undergone Kirschner-wire fixation for a left supracondylar fracture of the left humerus 9 years previously. After that, the right elbow dislocation and varus deformity gradually appeared. Imaging revealed posterolateral dislocation of the left elbow due to the absence of the coronoid process of the ulna. We reconstructed the ulnar coronoid process by intercepting the ipsilateral olecranon tip. After 22 months of follow-up, the range of motion of the left elbow joint was normal, and the cubitus varus deformity disappeared. The results of this report suggest that olecranon tip autografts are suitable to replace transverse coronoid defects. Given the patient's satisfactory clinical results, this reconstruction technique is safe and effective for the treatment of chronic elbow instability due to coronoid process defects of the ulna.

Reconstruction of coronoid process of the ulna: a literature review

As a pivotal part of the elbow joint structure, the coronoid process of the ulna plays a vital role in maintaining elbow joint stability. Loss of coronoid process height causes instability of the elbow joint depending on the fracture characteristics and size. The diagnosis and treatment of coronoid process fractures has gained widespread attention from orthopedic surgeons. Nevertheless, few reports have described reconstruction of coronoid process fractures and defects that affect elbow joint stability. Treatment of elbow joint instability induced by coronoid process defects is challenging because most cases are complicated by other elbow joint injuries. Moreover, the clinical efficacy remains unclear. The present narrative review was performed to examine the research progress on reconstruction of the coronoid process. The findings of this review provide evidence for clinical repair and reconstruction of coronoid process defects and contribute to the published literature on this topic.