*Review* **Beyond the Knife—Reviewing the Interplay of Psychosocial Factors and Peripheral Nerve Lesions**

**Johannes C. Heinzel 1,\*, Lucy F. Dadun <sup>1</sup> , Cosima Prahm <sup>1</sup> , Natalie Winter <sup>2</sup> , Michael Bressler <sup>1</sup> , Henrik Lauer <sup>1</sup> , Jana Ritter <sup>1</sup> , Adrien Daigeler <sup>1</sup> and Jonas Kolbenschlag <sup>1</sup>**


**Abstract:** Peripheral nerve injuries are a common clinical problem. They not only affect the physical capabilities of the injured person due to loss of motor or sensory function but also have a significant impact on psychosocial aspects of life. The aim of this work is to review the interplay of psychosocial factors and peripheral nerve lesions. By reviewing the published literature, we identified several factors to be heavily influenced by peripheral nerve lesions. In addition to psychological factors like pain, depression, catastrophizing and stress, social factors like employment status and worker's compensation status could be identified to be influenced by peripheral nerve lesions as well as serving as predictors of functional outcome themselves, respectively. This work sheds a light not only on the impact of peripheral nerve lesions on psychosocial aspects of life, but also on the prognostic values of these factors of functional outcome. Interdisciplinary, individualized treatment of patients is required to identify patient at risk for adverse outcomes and provide them with emotional support when adapting to their new life situation.

**Keywords:** peripheral nerve injury; psychosocial factor; nerve repair; neuroma; brachial plexus injury; compression neuropathy; pain; depression; disability; quality of life

#### **1. Introduction**

Peripheral nerve injuries (PNIs) have annual incidence rates in the USA of 43.8/1,000,000 for PNIs of the upper extremities [1] and 13.3/1,000,000 of the lower extremities, respectively [2]. PNIs often have disastrous sequalae on the affected patients' qualities of life, especially in case of major nerve injuries and often required long and elaborate rehabilitation [3]. Therefore, surgical treatment options to restore sensibility and muscular function as well as to relieve pain are subject of a plethora of clinical and preclinical research efforts [4–8]. In addition to research efforts to deepen under understanding of the peripheral nervous systems anatomy, as well as the neurobiological and pathophysiological aspects of PNIs [9], novel treatment options and concepts are rapidly evolving in the wake of refined microsurgical techniques [10]. In addition to advances in neurobiological, anatomical and (micro)surgical aspects, the current body of knowledge regarding epidemiology of PNIs is also steadily evolving. About 25 years ago, Noble was one of the first to publish epidemiological data concerning PNI in patients with multiple injuries seen at a regional Level 1 trauma center [11] and in recent years, large multicenter studies have contributed to our knowledge and understanding of the epidemiology of lower and upper extremity PNIs [12,13]. Representative patients' characteristics and socioeconomic sequelae of PNIs have recently been described by Bergmeister and colleagues, approaching another

**Citation:** Heinzel, J.C.; Dadun, L.F.; Prahm, C.; Winter, N.; Bressler, M.; Lauer, H.; Ritter, J.; Daigeler, A.; Kolbenschlag, J. Beyond the Knife—Reviewing the Interplay of Psychosocial Factors and Peripheral Nerve Lesions. *J. Pers. Med.* **2021**, *11*, 1200. https://doi.org/10.3390/ jpm11111200

Academic Editors: Andreas Arkudas and Raymund E. Horch

Received: 3 October 2021 Accepted: 11 November 2021 Published: 13 November 2021

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important perspective of research regarding surgical treatment of peripheral nerve lesions. According to their observations in a study sample of 250 patients with 268 PNIs, acute in-patient treatment costs for upper extremity nerve damages ranged between 2650€ and 5000€ [14]. Although the overall incidence of PNI has decreased in recent year, treatment costs are steadily increasing [1,2].

The severity of PNIs and postoperative functional outcomes are usually assessed by quantitative biomedical measures and postoperative evaluations of strength, sensory function, and range of motion [15,16]. However, research shining a light on the psychosocial aspects of such injuries is yet sparse [17,18]. Psychosocial factors have been defined as "characteristics or facets that influence an individual psychologically and/or socially" by Thomas [19]. Their role has been extensively studied and reviewed in diseases and conditions such as extremity trauma [20,21] or isolated hand injuries [22–24]. It was also shown that negative emotions prior to surgery are associated with adverse pain outcomes and postoperative disability [25–29]. Besides psychological aspects, the social impact of upper extremity injuries, e.g., predictors of return to work in patients suffering from work-related injuries has been addressed before in regard to other trauma, e.g., hand lesions [30,31]. It has also been demonstrated that the ability to return to work after traumatic injury does not only depend on physical capability and health but also by other aspects including psychosocial factors like psychological distress, personal income, the educational level of the injured person or the presence of a strong social network [32–34]. There is yet no comprehensive review summarizing the interplay of psychosocial factors with peripheral nerve injury and functional outcome following surgical treatment of such lesions. Therefore, it is the aim of this work to compile the current body of knowledge to provide surgeons, hand therapists, occupational therapists and other disciplines involved in the treatment of peripheral nerve injuries with another perspective on psychosocial aspects of peripheral nerve injuries to enable an even more holistic treatment approach.

### **2. Methods**

To gather eligible studies, a literature search on PubMed was performed using the search terms "peripheral nerve"; "peripheral nerve injuries"; "psychosocial "and "psychological". This yielded 95 results. After removal of duplicates, 90 papers remained for eligibility screening. Both original work and review papers were deemed fitting for discussion in this work. After removal of studies and reviews which addressed topics not related to our research questions and further reference screening of eligible work, 30 papers remained to be included in this review.
