Electrophysiological evaluation of phrenic nerve injury during cardiac surgery – a prospective,controlled, clinical study

Background

According to some reports, left hemidiaphragmatic paralysis due to phrenic nerve injury may occur following cardiac surgery. The purpose of this study was to document the effects on phrenic nerve injury of whole body hypothermia, use of ice-slush around the heart and mammary artery harvesting.

Methods

Electrophysiology of phrenic nerves was studied bilaterally in 78 subjects before and three weeks after cardiac or peripheral vascular surgery. In 49 patients, coronary artery bypass grafting (CABG) and heart valve replacement with moderate hypothermic (mean 28°C) cardiopulmonary bypass (CPB) were performed. In the other 29, CABG with beating heart was performed, or, in several cases, peripheral vascular surgery with normothermia.

Results

In all patients, measurements of bilateral phrenic nerve function were within normal limits before surgery. Three weeks after surgery, left phrenic nerve function was absent in five patients in the CPB and hypothermia group (3 in CABG and 2 in valve replacement). No phrenic nerve dysfunction was observed after surgery in the CABG with beating heart (no CPB) or the peripheral vascular groups. Except in the five patients with left phrenic nerve paralysis, mean phrenic nerve conduction latency time (ms) and amplitude (mV) did not differ statistically before and after surgery in either group (p > 0.05).

Conclusions

Our results indicate that CPB with hypothermia and local ice-slush application around the heart play a role in phrenic nerve injury following cardiac surgery. Furthermore, phrenic nerve injury during cardiac surgery occurred in 10.2 % of our patients (CABG with CPB plus valve surgery).

     

Isolated teres minor atrophy: manifestation of quadrilateral space syndrome or traction injury to the axillary nerve?

This article prospectively determines through magnetic resonance imaging (MRI) the incidence of isolated teres minor atrophy and its gender and age distribution, and documents associated findings related to the rotator cuff, labroligamentous complex, and quadrilateral space. Two hundred seventeen consecutive shoulder MRI examinations performed over a 3-month period were prospectively reviewed and evaluated for isolated teres minor atrophy. Twelve (5.5%) patients had non-compressive isolated teres minor atrophy. Ninety-two percent (n=11) of these patients had rotator cuff or labroligamentous complex tears. No patients had an associated mass within the quadrilateral space. The average patient age was 60 years and 11 of the 12 patients were male. Isolated teres minor atrophy on MRI is most commonly seen in older patients who do not fit the expected clinical presentation of quadrilateral space syndrome. The anatomical relationship of the teres minor nerve to the joint capsule and the frequency of associated shoulder injuries in these patients raises the possibility of an association between humeral decentering and teres minor atrophy. Quadrilateral space syndrome would appear to be a very rare cause of isolated teres minor atrophy.     

Does the location of the entry point affect the reduction of proximal humeral fractures? A cadaveric study

The selection of the correct entry point for stabilisation of long bone fractures and particularly of the humérus with intramedullary nailing is of paramount importance. The insertion of a nail from the correct entry point ensures anatomical alignment of the head and the shaft fragment. However, particularly for the humérus, the literature addressing this issue is obscure. Twenty cadaveric humeri without soft tissue attachment were studied. Two groups were studied: Group A (straight nail) and Group B (angled nail). A fracture of the surgical neck of the humérus was simulated. Then intramedullary nail was inserted through the correct entry hole. Displacement at the fracture site and force to reduce the displacement were measured. The average horizontal displacement was 2.5 ± 2.2 mm in Group A and 1.9 ± 1.1 mm in Group B. The humeral shaft tended to displace medially. The force required to reduce the produced displacement was usually less than 15 N. Anatomical reduction could not be obtained in 3/20 humeri even after applying a force of over 35 N. Our results of an average displacement of 2 mm following nail insertion, supports the significance of the entry point as a cause of loss of reduction at the fracture site post nail insertion. In most cases, anatomical reduction can be corrected with relative small forces, whereas in the rest the correction of the displacement is not feasible even with the application of substantial forces.     

What is the impact of continuous neuromonitoring on the incidence of injury to the recurrent laryngeal nerve during total thyroidectomy?

BackgroundContinuous intraoperative neuromonitoring may facilitate reversal of intraoperative injurious operative maneuvers in comparison with intermittent intraoperative neuromonitoring. The aim of this study was to evaluate the impact of the routine use of continuous intraoperative neuromonitoring on intraoperative injuries to the recurrent laryngeal nerve.MethodThis study was a prospective case series with retrospective analysis of consecutive patients undergoing total thyroidectomy from August 2013 to August 2019. During this period, intermittent intraoperative neuromonitoring (before Mar 2016) and continuous intraoperative neuromonitoring (after Mar 2016) were used in all patients.ResultsWe reviewed the outcomes of 603 patients (466 female patients) comprising 236 who underwent intermittent intraoperative neuromonitoring and 367 who underwent continuous intraoperative neuromonitoring. Intraoperative adverse electromyography events (>50% decrease in amplitude between VN1 and VN2) were observed in 87 patients (14.5%) and were less frequent in the continuous intraoperative neuromonitoring group (10.6 vs 20.3%, P = .001). Intraoperative loss of signal (electromyography events with VN2 ≤100μV) were observed in 35 patients (5.8%) without any difference between the 2 groups of patients (5.2 vs 6.8%, P = .415). Postoperative recurrent laryngeal nerve palsies were observed in 36 patients (5.9%) without any difference between the 2 groups of patients (4.9 vs 7.6%, P = .168).ConclusionThe routine use of continuous intraoperative neuromonitoring improves the rate of intraoperative adverse electromyography events but does not impact significantly the rates of loss of signal and recurrent laryngeal nerve palsy.     

Is there a safe zone to avoid superficial radial nerve injury with Kirschner wire fixation in the treatment of distal radius? A cadaveric study

Aim of the study

To determine the relation of the superficial radial nerve to bony land-marks and to identify a safe zone for K-wire pinning in the distal radius.

Method

The superficial radial nerve was dissected in sixteen upper extremities of preserved cadavers.

Results

We found that the superficial radial nerve emerged from under brachioradialis at a mean distance of 8.45 (±1.22) cm proximal to the radial styloid. The mean distance from the first major branching point of the superficial radial nerve to the radial styloid were 4.8 ± 0.4 cm.All branches of the superficial radial nerve were found to lie in the radial half of an isosceles triangle formed by the radial styloid, Lister''s tubercle and the exit point of the superficial radial nerve. There is an elliptical area just proximal to the Lister''s tubercle. This area is not crossed by any tendons or nerve. It is bounded by the extensor carpiradialis brevis, extensor pollicis longus.

Conclusion

Pinning through the radial styloid is unsafe as the branches of the superficial radial nerve passé close to it. The ulnar half of the isosceles triangle is safe regarding the nerve. The elliptical zone just proximal to the Lister''s tubercle is safe regarding the tendons and nerve.     

Case reports - Injury to the deep femoral artery during proximal locking of a distal femoral nail–a report of 2 cases

No Abstract available.     

Review of orthopaedic trauma surgery during the peak of COVID-19 pandemic – An observational cohort study in the UK

AimThis study aims to estimate the risk of acquiring medical complication or death from COVID-19 infection in patients who were admitted for orthopaedic trauma surgery during the peak and plateau of pandemic. Unlike other recently published studies, where patient-cohort included a more morbid group and cancer surgeries, we report on a group of patients who had limb surgery and were more akin to elective orthopaedic surgery.MethodsThe study included 214 patients who underwent orthopaedic trauma surgeries in the hospital between 12th March and 12th May-2020 when the pandemic was on the rise in the United Kingdom. Data was collected on demographic profile including comorbidities, ASA grade, COVID-19 testing, type of procedures and any readmissions, complications or mortality due to COVID-19.ResultsThere were 7.9% readmissions and 52.9% of it was for respiratory complications. Only one patient had positive COVID-19 test during readmission. 30-day mortality for trauma surgeries was 0% if hip fractures were excluded and 2.8% in all patients. All the mortalities were for proximal femur fracture surgeries and between ASA Grade 3 and 4 or in patients above the age of 70 years.ConclusionThis study suggests that presence of COVID-19 virus in the community and hospital did not adversely affect the outcome of orthopaedic trauma surgeries or lead to excess mortality or readmissions in patients undergoing limb trauma surgery. The findings also support resumption of elective orthopaedic surgeries with appropriate risk stratification, patient optimization and with adequate infrastructural support amidst the recovery phase of the pandemic.     

Avoidance of injury to the posterior neurovascular bundle during total ankle arthroplasty – A simple technical tip

Iatrogenic nerve injury to the tibial nerve is a serious but avoidable complication of total ankle replacements and may be under-reported as it may go unrecognised or thought to be due to tarsal tunnel syndrome. The tibial nerve is particularly vulnerable during the saw cuts at the posteromedial corner without appropriate protection. Prior to drilling the tibial and talar pins of the adjustment block for the Infinity ankle replacement we perform a 2 cm incision behind the medial malleolus. The tibialis posterior tendon sheath is identified and incised. A periosteal elevator is used to develop a plane between the back of the tibia and the tibialis posterior tendon and then exchanged for a mini Hohmann retractor protecting the neurovascular bundle. This allows us to drill the pins and saw cuts safely. The Hohmann retractor can be felt at the tip of the saw blade providing reassurance that the blade is not too deep. Our technique has not previously been reported in the literature. It acts as a simple reproducible way of avoiding injury to structures at the back of the ankle joint.     

Increasing the safety of minimally invasive hallux surgery—An anatomical study introducing the clock method

Background

The purpose of this study is to describe a simple and reproducible method to localize the neurological structures at risk and to describe a safe zone for hallux minimally invasive surgery (MIS) procedures.

Lateral cortex blowout during PFNA blade insertion in a subtrochanteric fracture-Should bone quality determine the type of nail used?

Subtrochanteric fractures pose a therapeutic challenge to the surgeons. With the advent of proximal femoral nails, most of the cases are treated with nailing. Newer nails like proximal femoral nail antirotation (PFNA) require the blade to be directly hammered into the bone compared to older nails where the screws are drilled and tapped before insertion. We report one such case in a middle aged female that had intraoperative lateral cortex blowout during PFNA blade insertion in a sclerotic bone. This occurrence to the best of our knowledge is unreported in literature. It is therefore imperative to consider the quality of bone before a decision is made on the implant chosen.