[Plate osteosynthesis of the coronoid process of the ulna]

Anteromedial coronoid facet fractures and associated ligament lesions: A case series

INTRODUCTION

Varus posteromedial rotational injury mechanisms lead to fractures of the coronoids process' anteromedial facet. As these fractures are often unstable, rapid fracture treatment is vital to prevent progressive osteoarthritis.

MATERIALS AND METHODS

Twelve patients with a fracture of the anteromedial facet treated surgically were enrolled in the study. Computed tomography images were used to classify the fractures according to the system by O'Driscoll et al. Clinical follow-up included each patient's medical record, surgical treatment algorithm, all complications encountered during the follow-up period, Disabilities of the arm, shoulder, and hand score, subjective elbow value, and pain.

RESULTS

A total of 8 men (66.7%) and 4 women (33.3%) were treated surgically and followed-up after a mean period of 45 ± 23 months. The mean DASH score was 11.9 ± 12.9 points. One patient complained of transient neuropathy in the innervation area of the ulnar nerve, however, this existed already pre-operatively and resolved after less than three months.

CONCLUSIONS

The presented patient cohort shows that AMF fracture of the coronoid process are unstable lesions according to the bony instability and the frequently ruptured collateral ligament complexes which need to be addressed. The MCL seems to be affected more frequently than previously appreciated.

LEVEL OF EVIDENCE

Level IV; Case Series; Treatment Study.

Anatomic relations of the median nerve to the ulnar insertion of the brachialis muscle: safety issues and implications for medial approaches to the elbow joint

INTRODUCTION

Preventing nerve injury is critical in elbow surgery. Distal extension of medial approaches, required for coronoid fracture fixation and graft-replacement, may endanger the median nerve. This study aims to describe an easily identifiable and reproducible anatomical landmark to localize the median nerve distal to the joint line and to delineate how its relative position changes with elbow flexion and forearm rotation.

MATERIALS AND METHODS

The median nerve and the ulnar insertion of the brachialis muscle were identified in eleven fresh-frozen cadaveric specimens after dissection over an extended medial approach. The elbow was brought first in full extension and then in 90° flexion, and the shortest distance between the two structures was measured while rotating the forearm in full pronation, neutral position and full supination.

RESULTS

The distance between the median nerve and the brachialis insertion was highest with the elbow flexed and the forearm in neutral position. All distances measured in flexion were larger than those in extension, and all distances measured from the most proximal point of the brachialis insertion were larger than those from the most distal point. Distances in pronation and in supination were smaller than to those in neutral forearm position.

CONCLUSIONS

The ulnar insertion of the brachialis is a reliable landmark to localize and protect the median nerve at the level of the coronoid base. Elbow flexion and neutral forearm position increase significantly the safety margins between the two structures; this information suggests some modifications to the previously described medial elbow approaches.

LEVEL OF EVIDENCE

Basic Science Study.

[Extensor digitorum communis split approach combined with loop-plate technique for treatment of ulnar coronoid fracture in terrible triad of elbow]

Objective

To explore the effectivenesss of simple lateral extensor digitorum communis (EDC) split approach combined with loop-plate fixation in the treatment of ulnar coronoid fracture in terrible triad of elbow (TTE).

Methods

The clinical data of 60 patients with TTE who met the selection criteria between January 2015 and May 2018 were retrospectively analyzed. There were 48 males and 12 females, aged from 18 to 60 years (mean, 37.4 years). All the patients were closed fractures. Injury causes included fall injury in 28 cases, falling from height in 20 cases, and traffic accident injury in 12 cases. All patients had no vascular and nerve injury, and the time from injury to operation was 1-14 days, with an average of 4.8 days. The height and size of the fracture of the coronal process were measured by CT and accurate classifications were made. All the 60 patients were treated with simple lateral EDC split approach combined with loop-plate to fix the ulnar coronoid fracture; 20 patients of radial head fracture were fixed with hollow screw, 32 patients with mini-plate fixation, 8 patients with radial head prosthesis replacement; 16 patients with suture and 44 patients with suture anchor to reconstruct lateral collateral ligament complex; 10 patients with residual instability of elbow joint were fixed with hinge external fixator, and others were fixed with adjustable tension brace after operation. Postoperative imaging examination was performed to evaluate fracture healing and complications, such as loosening or breakage of internal fixator, osteoarthritis, and heterotopic ossification, etc. During follow-up, the range of motion (ROM) of the elbow joint was recorded, including elbow flexion, extension, and forearm pronation, supination. Mayo elbow function score system (MEPS) was used to evaluate elbow joint function at last follow-up.

Results

All patients were followed up 16-24 months (mean, 20.2 months). All incisions healed by first intention after operation, and no complications such as vascular nerve injury, elbow joint instability, internal fixation failure, and infection occurred; the fracture healing time was 9-17 weeks (mean, 11.7 weeks). Four cases developed elbow stiffness after operation, and all underwent elbow joint lysis with internal fixator removal within 12-15 months after operation; 10 cases developed heterotopic ossification without special treatment. At last follow-up, the ROM of elbow flexion ranged from 85° to 135° (mean, 116°), the ROM of elbow extension ranged from 0° to 20° (mean, 11°), the ROM of forearm pronation ranged from 55° to 75° (mean, 70°), and the ROM of forearm supination ranged from 60° to 90° (mean, 83°). The MEPS score ranged from 55 to 100 (mean, 86.1); the effectiveness were excellent in 40 patients, good in 10 patients, fair in 6 patients, and poor in 4 patients, with an excellent and good rate of 83.3%.

Conclusion

The simple lateral EDC split approach is fully exposed, and the loop-plate can fix the ulnar coronoid fractures firmly and stably, which can restore the stability of the elbow joint, and the effectiveness is satisfactory.

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.

The treatment of anteromedial coronoid facet fractures: a systematic review

BACKGROUND

Fractures of the anteromedial facet (AMF) of the coronoid process are caused by a varus posteromedial rotational injury force, leading to instability in the ulnohumeral joint. AMF fractures are usually accompanied by avulsion of the lateral ulnar collateral ligament (LUCL). O'Driscoll's description and classification of AMF coronoid fractures has increased awareness and interest in this injury, but the optimal treatment has yet to be decided.

METHODS

We systematically reviewed the available literature searching electronic databases, MEDLINE using the PubMed interface and Embase. The primary objective was to determine outcome scores but also complication and revision rates depending on the fracture and its therapy in order to gain a more comprehensive picture. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were applied.

RESULTS

Initially, 304 publications were identified. Finally, 10 studies were left for inclusion, all of them retrospective in design, comprising 128 patients; the majority of them were male (75.7%). A total of 114 patients (89.1%) were treated surgically and 14 patients (10.9%) were treated conservatively. Among the surgically treated patients, 70.2% were treated with LUCL refixation. The average Mayo Elbow Performance Score of the surgically treated patients was 91.5 points. The average Mayo Elbow Performance Score of the conservatively treated patients was 91.4 points. A total of 10 patients (7.8%) required reoperation.

CONCLUSION

Surgery of AMF fractures leads to a satisfactory functional outcome in the vast majority of patients independent of the subtype. An algorithm for LUCL fixation is still pending. Conservative treatment may be considered under strict preconditions, especially for nondisplaced subtype 1 and 2 fractures, as these fractures show satisfactory functional outcomes when treated nonoperatively.