Secondary Radial Nerve Palsy after Minimally Invasive Plate Osteosynthesis of a Distal Humeral Shaft Fracture

Comparing iatrogenic radial nerve lesions in humeral shaft fractures treated with helical or straight PHILOS plates: a 10-year retrospective cohort study of 62 cases

BACKGROUND

Humerus shaft fractures are common and often treated surgically with a proximal humerus internal locking system like the long PHILOS^® plate. Due to its close anatomical proximity to the humerus, the radial nerve is particularly susceptible to traumatic and iatrogenic damage. The iatrogenic radial nerve damage associated with internal locking systems is described in about 7% of the cases. In order to avoid this lesion, helical plates have been suggested since 1999. This technique continues to not being used as standard as there is still a clear lack of evidence. This study aimed to understand if twisting a long PHILOS plate can reduce the rate of iatrogenic radial nerve damage in humerus shaft fractures.

METHODS

In this 10-year retrospective comparative study, patients with primary traumatic proximal humerus shaft fracture treated with a straight or twisted helical PHILOS^® plate were analyzed and compared. Among the 62 patients meeting the inclusion criteria between 2008 and 2018, 33 received a conventional straight plate, while 29 were treated with a helical plate. The primary endpoint was iatrogenic radial nerve damage immediately after surgery with a follow-up of at least 3 months.

RESULTS

No case of radial nerve damage was reported in the helical group. In the control group, iatrogenic radial nerve damage occurred in two cases (6%), which was not statistically significant when comparing both groups (p = 0.18).

CONCLUSION

Manually twisting long PHILOS^® plates is a safe procedure to avoid radial nerve lesion in humerus shaft fractures. Even though the group size did not allow a statistically relevant difference, we underline that only the helical group showed no iatrogenic radial lesion. This technique deserves further attention.

LEVEL OF EVIDENCE

Level 3, retrospective cohort study.

Surgical restoration of drop-hand syndrome with tendon transfer in patients injured in the Syrian civil war

BACKGROUND

The radial nerve is one of the most common war-related injury sites due to penetrating cutting tool injuries or gunshot wounds, resulting in drop-hand syndrome. The aim of this study was to evaluate the outcomes of tendon transfer in patients with drop-hand syndrome who had been injured in the Syrian Civil War.

METHODS

This level-II, prospective, comparative study included 13 civilians injured in the Syrian Civil War 2015 and 2017. The palmaris longus tendon was used for transfer to the extensor pollicis longus for thumb extension. The pronator teres was transferred to the extensor carpi radialis brevis for wrist extension. The flexor carpi radialis was transferred to the extensor digiti communis for 2nd, 3rd, 4th, and 5th finger extension. All outcomes of thumb abduction and extension, wrist extension, wrist flexion, and finger extension were assessed.

RESULTS

There was a high level of radial nerve injury in all patients included in the study. The time from injury to treatment ranged from 1.5 months to 9 months. The mechanism of injury most commonly observed was a gunshot wound, which was observed in 8 patients (61.5%), followed by a penetrating cutting tool injury (n = 3; 23.1%) and humerus fracture (n = 2; 15.4%).

CONCLUSIONS

In radial nerve injuries, successful results can be achieved with tendon transfer. All patients regained thumb abduction of up to approximately 60°. All the patients were able to bend the wrist, grip, and extend the fingers while in wrist flexion, neutral wrist and wrist extension positions. Although the reason for the radial injury varied, the postoperative outcomes were good for all patients, and the rehabilitation period progressed successfully in patients who underwent tendon transfer repair within 90 days of injury.

Biomechanical Study of the Fixation Strength of Anteromedial Plating for Humeral Shaft Fractures

Background:

Open reduction and internal fixation with plate and screws are the gold standard for the surgical treatment of humeral shaft fractures, this study was to compare the mechanical properties of anteromedial, anterolateral, and posterior plating for humeral shaft fractures.

Methods:

A distal third humeral shaft fracture model was constructed using fourth-generation sawbones (#3404, composite bone). A total of 24 sawbones with a distal third humeral shaft fracture was randomly divided into three Groups: A, B, and C (n = 8 in each group) for anteromedial, anterolateral, and posterior plating, respectively. All sawbones were subjected to horizontal torsional fatigue tests, horizontal torsional and axial compressive fatigue tests, four-point bending fatigue tests in anteroposterior (AP) and mediolateral (ML) directions and horizontal torsional destructive tests.

Results:

In the horizontal torsional fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 6.12°, 6.53°, and 6.81°. In horizontal torsional and axial compressive fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 5.66°, 5.67°, and 6.36°. The mean plate displacement amplitude was 0.05 mm, 0.08 mm, and 0.10 mm. Group A was smaller than Group C (P < 0.05). In AP four-point bending fatigue tests, the mean plate displacement amplitude was 0.16 mm, 0.13 mm, and 0.20 mm. Group B was smaller than Group C (P < 0.05). In ML four-point bending fatigue tests, the mean plate displacement amplitude were 0.16 mm, 0.19 mm, and 0.17 mm. In horizontal torsional destructive tests, the mean torsional rigidity in Groups A, B, and C was 0.82, 0.75, and 0.76 N·m/deg. The yielding torsional angle was 24.50°, 25.70°, and 23.86°. The mean yielding torque was 18.46, 18.05, and 16.83 N·m, respectively.

Conclusions:

Anteromedial plating was superior to anterolateral or posterior plating in all mechanical tests except in AP four-point bending fatigue tests compared to the anterolateral plating group. We can suggest that anteromedial plating is a clinically safe and effective way for humeral shaft fractures.

Causes of Secondary Radial Nerve Palsy and Results of Treatment

Background

The aim of this study was to analyze the causes that lead to secondary damage of the radial nerve and to discuss the results of reconstructive treatment.

Material/Methods

The study group consisted of 33 patients treated for radial nerve palsy after humeral fractures. Patients were diagnosed based on clinical examinations, ultrasonography, electromyography, or nerve conduction velocity. During each operation, the location and type of nerve damage were analyzed. During the reconstructive treatment, neurolysis, direct neurorrhaphy, or reconstruction with a sural nerve graft was used. The outcomes were evaluated using the Medical Research Council (MRC) scales and the quick DASH score.

Results

Secondary radial nerve palsy occurs after open reduction and internal fixation (ORIF) by plate, as well as by closed reduction and internal fixation (CRIF) by nail. In the case of ORIF, it most often occurs when the lateral approach is used, as in the case of CRIF with an insertion interlocking screws. The results of the surgical treatment were statistically significant and depended on the time between nerve injury and revision (reconstruction) surgery, type of damage to the radial nerve, surgery treatment, and type of fixation. Treatment results were not statistically significant, depending on the type of fracture or location of the nerve injury.

Conclusions

The potential risk of radial nerve neurotmesis justifies an operative intervention to treat neurological complications after a humeral fracture. Adequate surgical treatment in many of these cases allows for functional recovery of the radial nerve.