[Treatment of proximal humerus fractures: relative position of different locking plates to the axillary nerve]

Minimally invasive plate osteosynthesis of the humeral shaft with regard to adjacent anatomical characteristics

The study goal was to evaluate the distances from the radial (RN), the musculocutaneous (MN) and axillary nerves (AN) and the medial neurovascular bundle of the upper arm to a minimally invasive applied plate and to define its relation to the RN during different degrees of malrotation during MIPO. The sample involved ten upper extremities. Application of a PHILOS plate was performed through a Delta-split. Intervals between the AN, MN, RN and the medial vascular bundle were defined at various positions. The humeral shaft was artificially fractured at a height of about the mean of the plate. The distal fragment was brought into 15° and 30° internal (IR) as well as external rotation (ER) and here, the plate’s relation to the RN was evaluated. The medial neurovascular bundle intersected the plate at its distal part in two specimens. Regarding the distances from the RN to the plate during different rotation positions the distances became significantly longer during ER, respectively shorter during IR. The medial neurovascular bundle and the RN were identified as the main structures at risk. Care must be taken during distal screw placement and malrotation exceeding 15° must be avoided during MIPO.

Proximal Humerus Fractures: Evaluation and Management in the Elderly Patient

Introduction:

Proximal humerus fractures are common in the elderly. The evaluation and management of these injuries is often controversial. The purpose of this study is to review recent evidence and provide updated recommendations for treating proximal humerus fractures in the elderly.

Methods:

A literature review of peer-reviewed publications related to the evaluation and management of proximal humerus fractures in the elderly was performed. There was a focus on randomized controlled trials and systematic reviews published within the last 5 years.

Results:

The incidence of proximal humerus fractures is increasing. It is a common osteoporotic fracture. Bone density is a predictor of reduction quality and can be readily assessed with anteroposterior views of the shoulder. Social independence is a predictor of outcome, whereas age is not. Many fractures are minimally displaced and respond acceptably to nonoperative management. Displaced and severe fractures are most frequently treated operatively with intramedullary nails, locking plates, percutaneous techniques, or arthroplasty.

Discussion:

Evidence from randomized controlled trials and systematic reviews is insufficient to recommend a treatment; however, most techniques have acceptable or good outcomes. Evaluation should include an assessment of the patient’s bone quality, social independence, and surgical risk factors. With internal fixation, special attention should be paid to medial comminution, varus angulation, and restoration of the calcar. With arthroplasty, attention should be paid to anatomic restoration of the tuberosities and proper placement of the prosthesis.

Conclusion:

A majority of minimally displaced fractures can be treated conservatively with early physical therapy. Treatment for displaced fractures should consider the patient’s level of independence, bone quality, and surgical risk factors. Fixation with percutaneous techniques, intramedullary nails, locking plates, and arthroplasty are all acceptable treatment options. There is no clear evidence-based treatment of choice, and the surgeon should consider their comfort level with various procedures during the decision-making process.

MIPO of proximal humerus fractures through an anterolateral acromial approach. Is the axillary nerve at risk?

PURPOSE

It is known that shoulder surgery may cause iatrogenic injury to the axillary nerve as a serious complication, but there is little evidence to indicate whether the axillary nerve is at risk of injury during an anterolateral acromial approach for minimally-invasive plate osteosynthesis (MIPO) of proximal humerus fractures. We hypothesised that this surgical method is safe for the axillary nerve and would preserve it from iatrogenic injury.

MATERIALS AND METHODS

We conducted a prospective follow-up cohort study on 49 consecutive patients with proximal humerus fractures who were managed with MIPO through an anterolateral approach. All patients underwent standardised electroneurographic testing, with assessment of amplitudes of evoked compound muscle action potentials (CMAP) and distal motor latencies (DML) of the axillary nerves, pre- and post-operatively. Six weeks after injury, all patients underwent needle electromyographic (EMG) testing of anterior, middle, posterior deltoid, teres minor and paraspinal muscles for detecting abnormal muscle activity as a sign of acute denervation. After six months of physical rehabilitation, patients with axillary nerve injury underwent control electroneurographic testing to check the recovery of neurographic features (CMAP, DML). All nerve measurements were compared to reference values, and between right and left side.

RESULTS

Five patients had a mild-to-moderate traumatic axillary nerve injury before surgery. There were no significant differences between amplitudes of CMAP (p = 0.575) and DML (p = 0.857) pre- and post-surgical procedure.

CONCLUSIONS

These results confirmed safety of this surgical method in the preservation of axillary nerve from iatrogenic injury, but the course of the axillary nerve must be kept in mind.