Incidence, Risk Factors, Prevention, and Management of Peripheral Nerve Injuries Following Shoulder Arthroplasty

Electrodiagnostic Assessment of Peri-Procedural Iatrogenic Peripheral Nerve Injuries and Rehabilitation

Iatrogenic nerve injuries are a significant concern for medical professionals and the patients affected. Peri-procedural nerve injuries result in functional deficits associated with pain and disability. The exact pathophysiology and etiology of peri-procedural nerve injuries are complex and often elude providers. The rates of injury to specific nerves are unclear and relate to both procedural and patient specific risk factors. Initial classification of the nerve injury into neurapraxia, axonotmesis, mixed nerve injury, or possible complete transection (neurotmesis) guides rehabilitation and management. Electrodiagnostic medical consultation at least four weeks post-injury, supplemented with nerve imaging (ultrasound and magnetic resonance imaging), can allow for accurate nerve injury classification. Supplemented with nerve imaging and detailed clinical evaluation, treatment, recovery and rehabilitation can be maximized. Recognizing nerves at risk associated with medical and surgical procedures can facilitate injury avoidance and early diagnosis. If a nerve injury is incomplete, in an optimized physiologic milieu (good glucose control, smoking cessation, etc.), there is a good potential for spontaneous (total or partial) improvement over time. Surgical referral should be considered for severe nerve injuries within 6 months, especially if there is concern for neurotmesis, and/or deteriorating nerve function. This review gives guidance for approaching peri-procedural peripheral nerve injuries, including the timing and the role of electrodiagnostic medical consultation including serial electrodiagnostic studies in management and rehabilitation.

Comparison of Functional Outcomes and Complications of Inlay and Onlay Reverse Shoulder Arthroplasty in Neer Type 4 Proximal Humerus Fractures and Cuff Tear Arthropathy: A Multicentric Study

Background

This multicenter retrospective study was conducted with the objective of comparing the outcomes and complications between inlay and onlay reverse shoulder arthroplasty (RSA) in patients presenting Neer Type 4 proximal humerus fractures and cuff tear arthropathy. The primary aim of this investigation was to assess and juxtapose the clinical as well as functional outcomes of individuals who underwent onlay reverse shoulder arthroplasty with those who underwent inlay reverse shoulder arthroplasty.

Methods

A retrospective cohort study was conducted, involving patients who had undergone reverse shoulder arthroplasty between the period of 2016 and 2022. The study divided the population into two groups: Group A received inlay humeral components, while Group B received onlay humeral components. Functional outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) and Constant scores. Range of motion, infection, periprosthetic fractures, and nerve injuries were also assessed.

Results

The study included 67 patients in Group A and 62 patients in Group B. Group A had significantly better functional outcomes, as indicated by higher ASES and Constant scores (p < 0.05). Group A also had greater shoulder joint motion (p < 0.05). Periprosthetic fractures were significantly more common in Group B (p < 0.05). However, complication rates, including infection and instability, did not significantly differ between the groups (p > 0.05). Nerve injuries occurred in both groups, with slightly higher occurrence in Group B.

Conclusion

Inlay humeral components in reverse shoulder arthroplasty for Neer Type 4 fractures and cuff tear arthropathy resulted in better functional outcomes, increased range of motion, and lower incidence of periprosthetic fractures compared to onlay components. Onlay components showed potential advantages in reducing instability rates. Further studies with larger samples and standardized protocols are needed to confirm these findings.