Nerve injury after total hip arthroplasty: etiology, preventive strategies and medico-legal considerations

Abstract

Background

Nerve injuries in total hip arthroplasty (THA) are rare but clinically and medico-legally significant adverse events, sometimes severely affecting patients’ wellbeing through motor dysfunction and often permanent sensory alterations. Nerve injuries can result from complex interactions between a patient’s pathophysiology, the technical aspects of surgery and individual response to surgical trauma – often rendering them not entirely avoidable. Professional liability should be assessed within a comprehensive framework, considering biological and procedural variables, adherence to clinical preventive measures, and proper documentation.

Objective

This study provides a narrative review of the etiology of nerve injuries and identifies the nerves most frequently affected, with a focus on perioperative actions associated with specific nerve involvement. It also explores the medico-legal implications of post-THA nerve injuries, for an integrated approach to surgical risk management.

Results

Nerves more frequently involved during the four phases of the surgical management (preoperative, intraoperative, immediate postoperative and long-term postoperative) are, in order, the sciatic, the femoral, the obturator, the superior gluteal and the lateral femoral cutaneous nerves. Main activities and/or situations associated with the risk of nerve injury, to be prevented or managed properly, are the type of approach, specific intraoperative positioning and timing, surgical technique with ligations, dissections and retractors roles, limb length, local retraction or expansion due to infection, hematoma or cement loss. Therefore, the adverse outcomes should not be automatically interpreted as surgical negligence, especially when standard care and clinical risk management protocols have been followed and documented in clinical records. Thus, distinguishing between unfaulty adverse event and negligence.

Conclusions

The definition of a risk prevention and management strategy for nerve injury represents the first step in patient safety and, consequently, in reducing the likelihood of professional liability claim following THA.

Key Messages

• The sciatic nerve, followed by the femoral, the obturator, the superior gluteal and the lateral femoral cutaneous are the nerves at major risk of injury in case of total hip arthroplasty.

• Nerve injuries result from complex interplay between a patient’s characteristics and pathophysiology, the technique of surgery and the response to surgical trauma, not entirely manageable.

• The type of approach, intraoperative positioning, surgical technique and tools, limb length, local retraction or expansion due to infection, hematoma or cement loss are key preventive issues.

• Nerve adverse events should not be interpreted as surgical negligence, especially when standard care and risk management protocols have been implemented and documented.

1. Introduction

Total hip arthroplasty (THA) is one of the most widely performed and effective orthopaedic procedures, offering substantial improvements in quality of life for patients with degenerative, traumatic or inflammatory hip joint conditions [1].

Despite advancements in surgical techniques and approaches, devices, cementless and mini-invasive surgery, and the materials used, the risk of post-operative complications persists. Among these, peripheral nerve injury (PNI) stands out as the fourth most common complication following THA, with incidence rates ranging from 0.6% to 3.7%, depending on the surgical approach typology [2–4]. This risk is notably higher in revision surgeries, where rates can reach up to 7.6%, marking revision procedures as a significant risk factor [5].

However, considering revision surgery increases due to longer life span, more recent studies reported lower incidence of PNI in revision surgery [6]. In fact, the real incidence of these adverse events is to be weighed with consideration on the recent surgical development and clinical risk management strategies that over the years have deeply influenced occurrence rate as far as the bias in reporting some nerve injuries with only sensitive manifestation [7].

However, nerve injury remains a significant concern because of its potential to severely affect a patient’s wellbeing and the irreversible nature of its consequences, while improvements in surgical methods, preventive strategies and prosthetic designs have overall enhanced the outcomes of THA and minimized those complications [4]. Peripheral nerve injury is particularly concerning because of its potential for irreversible and long-term functional impairment, including sensory deficits, motor dysfunction and chronic neuropathic pain. Such outcomes may carry significant medico-legal implications, as they can lead to allegations of professional malpractice [8]. Even when symptoms are mild or primarily sensory, patients may perceive their recovery as incomplete and dissatisfaction can rapidly escalate into claims for compensation [7,9]. In fact, nerve injury remains one of the leading causes of malpractice litigation in orthopaedic surgery [10]. In particular, in patients undergoing THA, it accounts for approximately 14–31% of compensation claims related to prosthetic procedures [3,11,12].

The causes of PNI are multifactorial and concurrent: intraoperative trauma, excessive nerve traction or retractor prolonged application, or postoperative compression (e.g. from hematoma). Additionally, individual patient factors – such as obesity, developmental dysplasia of the hip, lumbar spine pathology, or previous surgeries – can alter anatomical relationships and increase anatomical and surgical susceptibility to nerve damage [8]. Despite the frequency and impact of this complication, there is currently no clear consensus on the surgical approach that minimizes the risk of nerve injury. While some evidence points to a higher incidence with the posterolateral approach, findings remain inconsistent [9]. The current literature lacks standardized definitions and consistent terminology for reporting such adverse events. The term PNI encompasses a wide spectrum of nerve damage, which can be classified by typology (neurapraxia, axonotmesis and neurotmesis) or by mechanism, ranging from entrapment and compression-related injuries to traumatic or iatrogenic causes. Iatrogenic PNIs may result from traction due to patient positioning under anaesthesia, inadvertent retraction or laceration during surgery, or postoperative entrapment secondary to scar formation, fibrosis or adjacent hardware [13].

Given the high clinical impact and medico-legal exposure associated with nerve injuries, early recognition and timely management, with accurate and rigorous clinical documentation, are crucial.

This narrative review aims to provide an in-depth review of the etiology, clinical management and medico-legal implications of nerve injury following THA, with the goal of supporting preventive strategies, guiding surgical decision-making and enhancing both patient safety and medico-legal risk mitigation. We aim thus to provide practical guidelines both for physicians operating in increasingly complex healthcare organizations and for legal and forensic professionals tasked with evaluating adverse outcomes.

2. Nerve involved

2.1. Sciatic nerve

Sciatic nerve represents the most frequently reported nerve injury following THA, accounting for about 80% of all nerve injuries reported in this context [14]. The occurrence of sciatic nerve injury after THA has been documented at approximately 1.5%. However, this rate may rise to between 3% and 8% in revision procedures and reach 5.8% in patients with preexisting developmental dysplasia of the hip [15]. The sciatic nerve exits the pelvis through the greater sciatic notch, positioned anteriorly to the piriformis muscle, before splitting into the common peroneal and tibial branches.

This anatomy may diverge in 6–8% of cases, as initially described by Beaton and confirmed by more recent anatomical studies [16]. These anatomical variants, especially when the common peroneal nerve branches proximally passing through the piriformis muscle, can increase the risk of injury to the common peroneal nerve. In fact, it has a more superficial distal course and consists of densely packed fascicles with less connective tissue compared to the tibial nerve, making it more susceptible to compression and transection. Patients with sciatic nerve palsy may present with foot drop, buttock pain radiating down the posterior thigh, and/or paresthesia in the sciatic nerve distribution [17]. The mechanisms contributing to sciatic nerve injury are several, with lower limb lengthening being one of the most significant factors. Historical reports and empirical data indicate that a lengthening of 3–4 cm may increase the risk of neurological damage. However, a study by Nercessian et al. [16], which analysed 1284 hip prostheses, found only one iatrogenic injury, with no other cases of sciatic nerve damage, even in significantly lengthened limbs. A study by Higuchi et al. [18] highlighted that a post-hip prosthesis lengthening greater than 5 cm is associated with an increased risk of sciatic nerve injury. A systematic literature review by De Fine et al. [19^,] did not identify a strong correlation between lower limb lengthening after hip prosthesis and sciatic nerve injury. Therefore, further high-quality studies are needed to confirm and weigh the correlation between a significant increase in limb length and the onset of sciatic nerve injury. Ischemic nerve injuries may develop due to compression, which can lead to nerve damage as early as 2–4 h after onset, as indicated by endoneurial oedema [20]. Such compression-related ischemia can arise from patient positioning during surgery; for example, in the lateral decubitus position, inadequate protection of the contralateral common peroneal nerve may lead to injury due to prolonged pressure. This injury typically occurs where the nerve wraps around the fibular head, a region particularly vulnerable to compression-related lesions. Direct nerve injury, including transection or laceration, is often the result of surgical instruments such as scalpels, electrocautery devices, reamers, screws, implants or even sutures [21].

Because of the prevalence of fibular area damage, it is helpful to double-check if there is an inability or impaired ability to raise the great toe or to perform dorsiflexion following surgery. In addition, if patients present oedema and tension on the wound along with pain in limb and the hips, it is strongly recommended to check for hematoma [14]. Additionally, bone cement can contribute to nerve injury through both compressive and thermal mechanisms, making it essential to remove any leaked material to prevent complications. Despite these known risk factors, in approximately 50% of cases where sciatic nerve injury is suspected, no definitive cause can be identified [22]. There are certain predisposing conditions that should be considered, such as double crush syndrome. This occurs when a nerve is subjected to irritation or compression at a proximal level, for example, at its radicular origin in the lumbar region, and subsequently experiences a second insult at the hip following surgery. This combination of injuries can make patients more susceptible to the development of peripheral nerve deficits [23].

2.2. Femoral nerve

Femoral nerve injury is the second most frequently reported nerve injury related to THA, accounting for approximately 2.3% of all nerve injuries. The incidence in THA patients has been documented between 0.04% and 0.8% [24]. The femoral nerve extends from the abdomen into the pelvis, passing anterior to the iliopsoas muscle and through the femoral triangle.

This area has limited elasticity, making the femoral nerve particularly susceptible to prolonged hyperextension, the typical position in which the joint is dislocated during anterior approach for THA implantation. Less common causes of femoral nerve injury include ileus muscle hematomas, particularly in patients undergoing anticoagulation therapy, as well as the placement of anterior acetabular retractors, especially during anterior and anterolateral THA approaches [25,26]. A study by Yoshino et al. [27] conducted on dead bodies, highlighted that the femoral nerve was located between 16.6 and 33.2 mm from the acetabular rim at angles ranging from 0° to 150° along a line drawn from the anterior superior iliac spine. The nerve was closest to the rim at 90°, identifying this region as a high-risk area for nerve injury during retractor placement. The placement of a retractor near the anterior rim of the acetabulum poses a potential risk, as studies have reported significantly elevated pressure levels around the nerve, particularly in individuals with lower body mass index and shorter patients or positioning [28,29]. The risk is further compounded in patients with altered hip anatomy due to previous surgeries, developmental dysplasia or congenital deformities, where the nerve may already be under increased tension [30]. Minimally invasive surgical techniques, which involve smaller incisions and limited soft tissue dissection, may also contribute to greater traction on the neurovascular bundle [31].

Additionally, the THA anterior approach or the lateral one in supine position has been associated with a higher incidence of femoral nerve injury, likely due to the reduced muscle mass in the anterior region, which offers less protection against retractor-induced compression [22].

2.3. Obturator nerve

Obturator nerve injury is an exceedingly rare complication following THA [4,7]. The obturator nerve courses through the pelvis, traversing the psoas major muscle before proceeding medially along the pelvic rim and exiting via the obturator foramen. Injury to this nerve typically manifests as medial thigh paresthesia, groin discomfort or adductor muscle weakness. Due to its infrequent occurrence and mild functional impact, diagnosis can be challenging. Zwolak et al. [32] reported a case in which intrapelvic cement extrusion resulted in obturator nerve palsy after THA. Even Mahadevan et al. reported a case of obturator nerve palsy secondary to cement extrusion [33]. Additional risk factors for obturator nerve palsy include disruption of the anterior quadrant or acetabular floor. The prevention of this rare adverse event relies on careful management of acetabular floor integrity, particularly during major trauma surgery. However, in the absence of an identifiable compressive cause, no standardized surgical protocol for the protection of this specific nerve is currently available. The existing literature, in fact, is extremely limited, consisting mainly of isolated case reports.

2.4. Superior gluteal nerve

The superior gluteal nerve exits the pelvis through the greater sciatic notch, emerging proximally to the piriformis muscle before branching into superior and inferior branches that supply the hip abductor muscles [34].

Nerve injury can result in abductor weakness and a Trendelenburg gait. Injury to this nerve can occur when the gluteus medius is dissected more than 5 cm proximally to the greater trochanter. Injury to this area is most frequently associated with direct lateral or anterolateral surgical approaches [4]. Another anatomical study by Starke et al. [35] suggested that special lateral and anterolateral approaches carry the highest risk for superior gluteal nerve injury, though prognosis tends to be more favourable than in sciatic nerve injuries. A study by Picado et al. [36] assessed 40 patients who underwent THA via a direct lateral approach and performed EMG at follow-ups. The study found superior gluteal nerve injury in 17 patients four weeks postoperatively, while only one patient had a positive Trendelenburg sign at 1-year postoperatively only. The authors therefore suggest that the nerve is affected by a transient functional injury, which should be monitored over time, but rarely results in permanent sequelae. Experimental dissections by Grob et al. [37] suggested that ligation of the ascending branch of the lateral circumflex femoral artery may contribute to superior gluteal nerve injury.

It is therefore not possible to estimate the incidence of such an injury, especially in light of this finding, which indicates a predominantly apraxia with progressive resolution, sometimes limited to electromyography signs only [38].

2.5. Lateral femoral cutaneous nerve

The lateral femoral cutaneous nerve originates from the posterior divisions of the anterior branches of L2 and L3 roots, running along the anterior surface of the iliacus muscle within the iliac fascia. It enters the thigh medially into the anterior superior iliac spine, passing over the sartorius muscle before branching. The incidence of LFCN injury after THA is highly variable across studies, depending on the characteristics of the analysed populations, the definition of neurological injury and the type of approach. The reported incidence rates range from 15% to 81%, but as aforementioned it may be inconsistently reported [39]. As the LFCN is a purely sensory nerve, the true magnitude of this complication is often difficult to assess: in many cases, symptoms are mild, transient or even unrecognized, and sometimes attributed to superficial peri-scar sensory disturbances related to the surgical incision [40]. Anatomical course plays a crucial role in this complication: anatomical studies conducted on 18 cadavers have identified three distinct branching patterns (sartorius-type, posterior-type and fan-type) each occurring in approximately one-third of cases [39]. The risk of LFCN injury is almost negligible in posterior, lateral or SuperPATH approaches, where the surgical field is anatomically distant from the nerve, while it becomes significant in the direct anterior approach due to its close relationship with the surgical corridor [41]. As a purely sensory nerve, lateral femoral cutaneous nerve injury does not lead to motor deficits on hip function but is a recognized complication of the anterior THA approach. Despite the mentioned frequency of lateral femoral cutaneous nerve involvement in THA, literature on its etiology, prognosis and management remains limited, with conflicting reports [42,43].

3. Risk and predisposing factors

A combination of patient-specific and pre-existing genetic, metabolic, anatomical factors influences both the risk of occurrence and the potential severity of the outcome of the nerve injury in THA. Metabolic conditions such as diabetes, obesity and vascular diseases further contribute to this risk [6,44,45]. These disorders affect the body’s ability to respond effectively to surgical trauma. In particular, diabetic patients often suffer from compromised microvascular circulation, which can lead to reduced oxygenation of the nerves and make them more vulnerable to irreversible damage, even from mild mechanical insults during surgery. Age is another crucial factor. With advancing age, the biological processes responsible for tissue repair and nerve regeneration tend to slow down [46]. The elasticity of tissues, including muscles and ligaments, decreases, making them more susceptible to traction or compression-related injuries during surgical manipulation. Older patients also exhibit altered inflammatory responses, which may lead to exaggerated inflammatory reactions that further impair nerve function and recovery [47]. Impaired microcirculation, particularly in patients with vascular pathologies, increases the risk of ischemia and permanent nerve damage. In addition, small anatomical differences – often difficult to detect in preoperative evaluations – can influence surgical outcomes. Variations in the position, depth, and course of nerves, or their relation to osseous and muscular structures, can make some nerves inherently more prone to injury [48,49]. In revision surgeries, the presence of fibrotic scar tissue surrounding the nerves may limit their mobility and increase the risk of intraoperative trauma. Conditions such as developmental dysplasia of the hip or post-traumatic arthritis also contribute to anatomical complexity, which can challenge even experienced surgeons and further increase the risk of nerve injury [4,6]. Understanding these multifactorial risks is essential to improving surgical planning, tailoring perioperative management and implementing preventive strategies aimed at reducing the incidence and severity of nerve injuries in patients undergoing THA.

4. Prevention strategies

Effective primary prevention plays a crucial role in mitigating the risk of nerve injuries and their potentially severe consequences following THA.

This begins with a comprehensive understanding of anatomy, including the ability to identify anatomical variations that may increase the likelihood of nerve injury. A thorough preoperative assessment is essential, with particular attention to anatomopathological risk factors such as dysplasia of the hip, prior hip surgeries, preexisting neuropathies, lumbar pathologies and conditions that may predispose patients to nerve compromise (Table 1). In a case-control study, one of the greatest risk factors for development of sciatic nerve palsy after THA is the preexistence of lumbar spine disease, thus highlighting the relevance of pre-surgical clinico-instrumental assessment [3].

Table 1.

Synthesis of the main activities and situations involved in nerve injuries prevention.

Phase	Actions	Nerve involved
Preoperative	Anatomical assessment	All
	Anamnestic recollection	All
During surgery	Type of approach: direct anterior	Femoral
	Type of approach: posterior-lateral	Sciatic
	Type of approach: lateral, antero-lateral	Sciatic
	Limb length	Superior gluteal
	Specific position and timing: lateral decubitus	Sciatic
	Type of approach and specific position: lateral approach in the supine position	Femoral
	Retractors	Femoral
	Acetabular floor integrity	Obturator
	Surgical technique: gluteus medius dissection more than 5 cm proximally to the greater trochanter or ascending branch of the lateral circumflex femoral artery ligation	Superior gluteal
Immediate postoperative	Hematoma or surgical site infection	All
	Cement loss	Obturator
Long-term postoperative	Hematoma	All
	Surgical scar, surgical site infection or tension	All

During surgery, several technical precautions should be observed to minimize nerve injury risk. Proper patient positioning is critical, as incorrect placement may lead to excessive nerve traction or compression [39]. In particular, prolonged lateral decubitus without adequate padding can cause external popliteal sciatic nerve compression, especially over bone prominences such as the fibular head [5]. Retractor placement should be meticulously controlled to prevent prolonged pressure on nerve structures, particularly in anterior and anterolateral approaches and in younger patients. The increased risk in younger patients may be explained by the greater retraction force due to their more robust muscles and tissues and/or more severe diseases [5,50,51]. Moreover, the supine position increases the risk of nerve injury, particularly involving the femoral nerve, as demonstrated by a study showing that this structure moves closer to the acetabulum when patients lie supine, whereas it moves farther away in the lateral decubitus position [52]. Careful positioning, adequate protection and limiting traction time, as the overall surgical time, are therefore essential to reduce the risk of these nerve injuries [5].

Additionally, bone cement leakage poses a significant risk of nerve compression and thermal injury, highlighting the importance of careful cement handling and post-cementation evaluation. This is particularly true in cases of acetabular floor discontinuity or irregularity, when looking at the obturator nerve, even if more typical of trauma surgery than elective one.

For high-risk patients, the use of intraoperative neuromonitoring, particularly somatosensory evoked potential, can help detect early signs of nerve compromise, allowing immediate adjustments during the procedure [53,54].

Surgeons should also be mindful of the cumulative effects of traction, soft tissue tension and limb lengthening, all of which can contribute to postoperative neuropathy.

In the immediate postoperative phase, imaging plays a key role in assessing implant positioning, acetabular penetration, cement extrusion, hematoma formation and other factors that may predispose patients to nerve injury. At the same time, electromyography or imaging studies, as part of broader follow-up protocols, may allow for the early detection of nerve impairment, which, although sometimes subclinical and characterized by transient functional disturbances, may appear and then progressively resolve without permanent sequelae. This was the case of reported rare superior gluteal nerve involvement. Early detection of these complications could allow for timely intervention, potentially preventing persistent nerve deficits [26,55,56].

Early patient management also means promptly informing the patient about the adverse event and its possible course. In fact, as in the preoperative information phase, a clear mention of potential complications and how they will be managed is crucial in shaping patient expectations and satisfaction [57].

Consequently, planning clinical monitoring during the post-surgical phases, taking into account load-bearing, ambulation, sports activities and overall rehabilitation, integrated with patient education on the early recognition of any signs of nerve dysfunction, is crucial for achieving optimal long-term functional recovery and ensuring that nerve-related complications are promptly managed [58,59].

5. Medico-legal considerations

Despite ongoing advancements in surgical techniques and the increasing use of sophisticated diagnostic and preventive tools, the anatomical complexity of the hip region and the biological variability among patients introduce an irreducible margin of risk, with important practical and theoretical implications for the prevention and management of adverse events in medico-legal perspective [10,60].

This primarily requires an appropriate indication for surgery, particularly since hip arthroplasty is typically an elective procedure. Such indication is critical in relation to patient expectations for symptom improvement, increasing qualitative and quantitative demands postoperatively, ultimately shaping the overall risk–benefit assessment of the surgical approach. In elective surgery, therefore, the preoperative assessment pathway, the failure of conservative treatment, and the provision of information on expected benefits, risks and realistic chances of improvement become central elements in shaping surgical recommendation [61]. Identifying and recording risk factors in the preoperative phase supports clinical decision-making and patient counselling and plays a critical role in medico-legal defence by offering objective evidence that the patient’s condition was inherently associated with an elevated procedural risk, but yet the benefit of the treatment supports surgical indication [62]. As surgical practices evolve, incorporating technologies such as preoperative 3D planning and intraoperative navigation, robot-assisted procedures, the definition of the standard of care becomes increasingly dynamic and evidence-based [63]. And consequently, the professional standard expected from the surgeon is increased along time [64].

Therefore, a key aspect of any medico-legal assessment is the ability to contextualize the injury within the full clinical scenario [11]. In general, the proper approach to risk management, does not lie in eliminating a natural element of unpredictability, but rather in controlling what is foreseeable and manageable through regular care planning, the definition of procedures validated based on evidence, and adaptations according to higher risk of injury. Implementing these measures, and subsequently acknowledging them in case of litigation, leads to a fair assessment of the case as a non-preventable error, and therefore not attributable to improper, negligent or imprudent conduct by the practitioner [65]. The definition of an adverse event in a judicial context is thus necessarily subsequent to a reasoning process that excludes human causes [66]. Another important clarification concerns the extent of diligence required by civil law from the healthcare professional. In trials for compensation, certain conditions entailing the ‘resolution of extraordinarily difficult technical issues’, to be assessed on a case-by-case basis, may constitute a mitigating factor with respect to the standard of professional conduct expected and demanded. These refer to technical problems that are either novel, meaning not yet adequately addressed by scientific literature, or particularly complex, requiring a level of technical effort largely above the usual one [67]. In the context of elective surgery, where the indication for the procedure, the possibility for detailed study and planning, and the careful selection of the intervention type and timing are all available as previously discussed, only cases involving experimental techniques performed in highly specialized centres seems to justifiably be considered as presenting ‘extraordinarily difficult’, distinguishing patient’s mere ‘clinical complexity’, which instead requires a proper assessment of the indication and timing of the treatment.

Complete and accurate documentation in the clinical records of the patient’s clinical course, the informational process, and any technical challenges encountered during surgery is an essential component of both the standard of care and professional conduct [61]. The focus is not solely on the technical skill required to perform THA, but more generally on the comprehensiveness of patient care. This means that the operating surgeon cannot fail to ensure that the patient receives complete and appropriate clinical management, from preoperative assessment, through the pre-discharge visit, to postoperative follow-ups. Obviously, this does not imply personally performing all these tasks or be responsible for all post-discharge and rehabilitation period, but rather, within the team and the specialized facility, verifying the suitability, shared understanding and continuous implementation of the care pathway for the patient with severe hip osteoarthritis and disability undergoing to THA. The overall care pathway, standardized and continuously updated based on the best available evidence, can effectively address the risk of potential adverse events, thereby managing that portion avoidable [68].

It is then essential that patients are comprehensively informed regarding both the strategies to grant optimal care, including compliance to postsurgical and rehabilitation path, those implemented to mitigate risk and the potential occurrence of complications linked to their unique biological profile, up to and including the possibility that the treatment may be deemed inadvisable [69]. The informed consent must be clearly written and easily understandable by the patient [70].

Finally, the role of pre-existing conditions, particularly those affecting the same peripheral nerves discussed, must be carefully considered, including symptoms that are less assessable through instrumental assessment, such as discomfort, chronic pain or sensory alterations. It is important to note that the compensation system is predicated solely on harm resulting from non-compliant or negligent conduct. Accordingly, causal analysis of pre-existing conditions must address two dimensions: first, the extent to which the pre-existing condition contributed to the occurrence of the injury; and second, with regard to the economic evaluation of damages, the proportion of the impairment attributable to malpractice [71].

6. Current limitations and gaps

A first limitation of the review is the lack of standardized terminology regarding nerve injuries reflecting available studies. The term nerve injury is often used inconsistently to describe a wide spectrum of conditions, which may be defined by pathogenic mechanisms, neurophysiological findings, or clinical signs and symptoms. These considerations were also presented as background, justifying a preliminary narrative approach to the topic. This inconsistency makes it difficult to systematically reconstruct the incidence of individual nerve injuries.

Furthermore, the common tendency to compare hip surgery approaches in relation to adverse events, including nerve injuries, rather than evaluating nerve complications from elective hip surgery as a whole, results in fragmented data that are poorly comparable across studies. More investigations are therefore needed to obtain quantitative data, which are currently limited in this area of the literature.

In this perspective, efforts should also focus on the standardization of terminology and reporting, which is already reflected in certain national and regional macro-indicators of outcomes, volumes and processes, such as hip replacement: ‘revision within 2 years after surgery’ or hip replacements: ‘readmissions within 30 days’, with the aim of achieving greater granularity beyond single-centre databases or single pathologies registries.

7. Conclusions

Nerve injuries represent one significant risk and possible adverse event after THA. However, their occurrence should not be considered a sign of failed surgical technique or lack of surgeon expertise, and then quite infer negligence. The focus lies not so much on the risk/adverse event itself, but rather on the appropriateness of care and compliance with the standard of care and professional conduct, including the implementation of measures of diligence and prudence necessary to contain known and preventable risks. Professional liability must be determined through an objective analysis of medical records and a thorough clinical evaluation of the patient. This analysis should consider the patient indication for surgical approach, the nature and potential difficulty of the procedure, the informed consent provided, the adherence to best practices and international guidelines, the reference to standardized care protocols, including general and specific risk prevention strategies. The medico-legal evaluation of postoperative complications, such as nerve injuries, can also serve as an informational source to be applied proactively within clinical risk management strategies, by designing pathways and training programs tailored to causal relationships and the definition of expected behaviours.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data sharing is not applicable to this article as no data were created or analysed in this study.