Treatment, Diagnostic Criteria and Variability of Terminology for Lateral Elbow Pain: Findings from an Overview of Systematic Reviews

Background: Lateral elbow pain (LEP) represents a musculoskeletal disorder affecting the epicondyloid region of the elbow. The terminological framework of this problem in literature, to date, is confusing. This systematic review (SR) aims to analyse the panorama of the scientific literature concerning the pathogenetic framework, treatment, and clinical diagnosis of LEP. Methods: We conducted an SR according to the guidelines of the PRISMA statement. We performed research using the electronic Medline, Epistemonikos, and Cochrane Library databases. The research started on 12 January 2022 and finished on 30 April 2022. We included all systematic reviews and meta-analyses published, in English, between 1989 and 2022. The articles’ selection was based on critical appraisal using Amstar 2. In the selected reviews we obtained the etiopathogenic terminology used to describe the symptoms, treatment, and diagnostic criteria of LEP. Results: Twenty-five SRs met the eligibility criteria and were included in the study. From these SRs, 227 RCT articles were analysed and different treatments proposals were extracted, such as exercise, manipulation corticosteroid injection, and surgery. In the selected articles, 10 different terms emerged to describe LEP and 12 different clinical tests. The most common treatments detected in this SR were a conservative multimodal approach (e.g., eccentric exercises, manual therapy, acupuncture, ultrasound), then surgery or other invasive treatments (e.g., corticosteroid injection, tenotomy). The most common term detected in this SR was “lateral epicondylitis” (n = 95, 51.6%), followed by “tennis elbow” (n = 51, 28.1%) and “lateral epicondylalgia” (n = 18, 9.4%). Among the diagnostic tests were painful palpation (n = 101, 46.8%), the Cozen test (n = 91, 42.1%), the pain-free grip-strength test (n = 41, 19.0%), and the Maudsley test (n = 48, 22.2%). A total of 43.1% of RCTs (n = 96) included subjects with LEP > 3 months, 40.2% (n = 85) included patients with LEP < 3 months, and 16.7% of the items (n = 35) were not specified by the inclusion criteria on the onset of symptoms. Conclusions: In this SR, a considerable terminological heterogeneity emerged in the description of LEP, associated with the lack of clear and recognised diagnostic criteria in evaluating and treating patients with lateral elbow pain.


Introduction
Lateral elbow pain (LEP) represents a musculoskeletal condition, between musculoskeletal disorders (MSDs), affecting the epicondyloid region of the elbow [1,2]. It mainly affects workers between 35 and 54 years of age, with a prevalence of between 1% and 3%.

Purpose of the Study
The following question was defined: "What are the most commonly used treatments, etiopathogenetic terminologies, and diagnostic criteria adopted to identify patients with LEP?"

Search Strategy
We performed research on the three main electronic databases for systematic reviews: Medline (1996-2021), the Epistemonikos Database (2009-2021), and Cochrane Library .
The keywords used for the purposes of the research were: "tennis elbow" (MeSH terms), "lateral epicondylitis," "lateral elbow tendinopathy," and "lateral epicondylalgia." The Boolean operator OR allowed for the selection of most of the target SR. PubMed Clinical Queries was used on PubMed Central as a tool to enter the query string and select the systematic reviews and the meta-analysis on the topic.
This step was finally completed and integrated with manual research of the bibliographic references. The research started on 12 January 2022 and ended on 31 January 2022.
We have reported the complete search strategies in Appendix A.

Eligibility Criteria
We included articles according to the following criteria: (a) published from 1989 to 2022, (b) written in English, (c) relating to the diagnosis and treatment (conservative and surgical) of LEP, (d) defined one or more terms of classification of LEP, and (e) reported a study design as SR with or without metanalysis (MA).
We excluded articles published before 1989. RCTs, scoping reviews, literature reviews, and case studies were not included in our SR. Studies that were not exclusively about LEP were excluded.

Study Selection
Two reviewers (SV and DP) performed the selection and data collection process under the supervision of a third author (FM). First, all records were screened by the management software for Rayyan systematic reviews (https://rayyan.qcri.org, accessed on 14 January 2022), whereas references were managed by the Mendeley software (https: //www.mendeley.com, accessed on 31 January 2022). Then, after removing the duplicates, the titles and abstracts were screened. Lastly, full texts of the identified studies were obtained for further assessment and analysed independently according to the eligibility criteria by two reviewers (S.V. and D.P.). Where appropriate, the authors were contacted in order to obtain the full text.
The language did not pose any barrier to the analysis of the articles, and a native US translator was consulted when necessary.

Data Collection
For each SR, the following data were extracted: study design (SR o SR with MA); author, year of publication; the number and characteristics of participants/populations; treatments; definition and/or any diagnostic criteria for LEP (e.g., specific diagnostic test or a diagnostic cluster); analysis of the variables and the outcome of the studies; and study settings/country.
Overlapping of RCTs within each SR was considered to avoid entering study data twice in the data analysis, as suggested from other overviews of SRs [15].

Quality Assessment
Furthermore, to make sure no methodological low-quality publications were included, only systematic reviews or metanalyses were selected through AMSTAR II (Assessing the Methodological Quality of Systematic Reviews) [17] and then analysed with the RoBis tool (Risk of Bias in Systematic Reviews) [18].
Although AMSTAR 2 is not aimed at generating an overall score cut-off, to judge the quality of the SRs, it recommends defining critical items, which helps identify any weaknesses in these items to make an overall assessment of the reliability of the results of the selected SRs. All SRs that received a low or very low overall rating (one point or more of a critical point) were excluded [17].
AMSTAR II is the most widely used SR assessment tool but focuses on the overall critical assessment of reviews and does not analyse the risk of bias in the systematic review. RoBis's approach aligns with the most recent methods used to develop the risk of bias assessment tools and promises to improve the assessment process in the overview and guidelines. A recent study evaluated the interrater reliability (IRR) of AMSTAR II and RoBis in judging individual domains and the general methodological quality/risk of bias of systematic reviews, the concurrent validity of the instruments, and the time needed to apply them. The results showed that AMSTAR II and RoBis have overlapping IRRs, though they are different in construction and applicability [19].
According to the specific study design, the risk of bias (RoB) of the included studies was analysed using the RoBis tool [18]. The RoBis tool was used by two independent reviewers (S.V. and L.D.F.) to assess the risk of bias in selected SRs. All the studies included RCTs of a methodologically medium-high quality level that considered subjects displaying unilateral LEP. The score of the RoBis was not adopted as a criterion to include or exclude studies in this SR.  [16]. Figure 1. PRISMA flow diagram summarising the study selection process [16].
The research and the following selection of the studies led to the inclusion of 19 SRs and 6 SRs with MAs for 25 selected articles (Table 1). There is insufficient evidence to either support or refute the use of acupuncture (either needle or laser) in the treatment of lateral elbow pain.

Borkholder et al. (2004) [24] USA
To confirm or refute the efficacy of using splints in the treatment of lateral epicondylitis.     Low and very low certainty evidence suggests exercise is effective compared with passive interventions with or without invasive treatment in LET, but the effect is small.

Characteristics of Treatment and Patients
Within the included SRs, a range of the most used clinical treatment strategies in the case of LEP was analysed, among which were ultrasound therapy, the use of splints, acupuncture, extracorporeal shockwave therapy (ESWT), manipulations, low-level laser therapy (LLLT), therapeutic exercise, dry needling, surgery, PRP, corticosteroid injections, and the use of nonsteroidal anti-inflammatory drugs (NSAIDs). Two hundred sixteen RCTs of the respective SRs were examined. All the selected studies were approved by the ethical committee and the participants' written informed consent was obtained. One of the 24 SRs analysed the efficacy of ultrasounds to treat LEP and comprised four RCTs [21]. Two reviews dealt with the use of splints in the case of elbow pain [22,24], whereas a 2004 Cochrane SR studied the effects of ESWT [26]. A 2004 review [31] analysed the efficacy of LLLT, and three SRs gathered the RCTs on therapeutic exercise [25,34,37,45]. Acupuncture in LEP treatment was studied in three SRs, including 16 RCTs of good methodological quality [23,38,40]. Two SRs collected RCTs that assessed the efficacy of manipulations in the case of LEP [27,42]. Within seven SRs, the authors pointed out a reduction of symptoms in subjects affected by LEP thanks to cortisone, botulinum, PRP injection, or the intake of NSAIDs [29,30,32,35,39,43]. Two SRs studied the most resolutive surgery techniques for LEP [33,41]. One study analysed the effect of trigger-point dry needling in subjects with LEP [44].
A total of over 20,000 patients were involved in the 227 RCTs analysed in this SR. For each study, the data linked to the terminology used to define the LEP and the inclusion criteria of the subjects were collected (symptom inception and clinical diagnostic tests). Details of the treatments and terminology adopted are described in Table 2.

Characteristics of the Included Studies
The oldest SR dated back to 1999 and analysed the effectiveness of US in LEP; the most recent SR was published in 2021 and collected the RCTs concerning the effectiveness of trigger-point dry needling in LEP [21,45]. The study by Bisset et al. collected the largest number of RCTs (24) and presented the largest number of selected subjects (1760) [27]. Butchbinder's SR on the effectiveness of ESWT in the treatment of LEP selected only two high-quality RCTs [26].

Risk of Bias of the Included Studies
Details of the RoBis of the included studies are presented in Table 3. Most items of the RoBis assessment tools used for the quality assessment were rated as low risk. Six SRs showed a low risk of bias in the items concerning the eligibility criteria, selection of studies, data collection, study appraisal, and synthesis [22,23,27,33,38,42]. Some SRs did not clearly describe the eligibility criteria based on the study characteristics and sources of information [26,30,37,39,43]. Items related to a low risk of bias in the selection of studies were lacking in seven SRs; in particular, problems were found concerning the research strategy used and the selection criteria [24,27,[34][35][36]39,42]. Moreover, in four studies the item about the data collection and study appraisal was not completely described or had biases of assessment [26,29,37,41]. Synthesis and findings were evaluated. A high risk of bias in the synthesis and findings process was recorded in nine SRs, particularly in the presentation of the results and in the analysis of the selected studies [21,24,25,28,31,34,36,40,41,45]. Table 3. RoBis, risk of bias for systematic reviews [18].

Data Collection and
Study Appraisal

Risk of Bias in the Review
Healthcare 2022, 10, x Table 3. RoBis, risk of bias for systematic reviews [18].                   Table 3. RoBis, risk of bias for systematic reviews [18].

Review
Year Country   Table 3. RoBis, risk of bias for systematic reviews [18].

Summary of findings
Results concerning the terminology, diagnostic test, and onset criteria of symptoms used in the selected articles are reported in Figure 2, Figure 3, and Figure 4.
Ninety-nine out of 227 articles used the term "lateral epicondylitis," whereas 56 RCTs talked about "tennis elbow" and 18 about "lateral epicondylalgia." Only one of the selected articles described the symptomatology as "lateral elbow pain" [33].
The onset timings of symptoms in the subjects selected by the 227 RCTs included in the SRs were collected. A total of 42.1% of the studies analysed patients that had been displaying symptoms for more than 3 months. A total of 89 articles (40.2%) included patients with LEP for less than 3 months. The remaining 39 articles did not describe a cut-off related to the timing of the symptoms' onset .

Discussion
The data collection of the terms used to give a more aetiologically correct meaning to a set of clear symptoms such as the ones associated with LEP showed a wide heterogeneity dictated both by a merely biomedical view of the musculoskeletal problem and by the habit of using a term that was first coined in 1883 and is still used to this day [46]. The term "tennis elbow" was used in 56 out of the 227 selected RCTs and, indeed, refers to pathology with a high incidence in tennis. However, it is well known that LEP mainly affects the working population category, especially those involved with heavy lifting and subtle movements of the upper limbs; the LEP incidence in tennis is rather low and affects mainly amateur tennis players [5,12,14,46]. Evaluation using the RoBis tool showed a low bias risk in most of the selected SRs [18,19]. The studies showed good methodological rigour from the point of view of the eligibility and selection criteria of the RCTs. In contrast, the synthesis of the studies was often difficult due to the heterogeneity of the outcomes and the evaluation criteria.

Terminology Variability in LEP
The term "lateral epicondylitis" was used in 51.6% of the articles and recalled the primarily inflammatory nature of LEP. After several histopathological studies on tendons, Khan et al. (2002) recommended opting for the term "tendinopathy" to describe the symptomatology more accurately [47]. Indeed, several authors underlined that LEP is not caused by an inflammatory component but by a degenerative tendon process in the following years [46][47][48].
The term "tendinopathy," in particular "lateral elbow tendinopathy" or "lateral epicondylar tendinopathy," was mentioned in five articles (2.1% and 0.5%). It is worth noting that three of these RCTs were selected from an SR by Raman et al. (2012) that dealt with the therapeutic exercise's efficacy in the treatment of LEP [34]. This link between exercise and tendinopathy is tightly connected to the cultural revolution in the rehabilitation in treating overload issues and tendinopathies. Several authors, such as Maffulli, Cook and afterwards Rio, were among the first to understand the importance of exercise in this kind of pathology [49][50][51].
Among the 227 selected RCTs, the term "lateral epicondylalgia" was included in 19 studies (9.4%). In an SR by Bisset et al. (2005), 28 RCTs were analysed that dealt with the most effective interventions in the case of "lateral epicondylalgia" [27]. This terminological and conceptual transition underlines the shift from the biomedical pathology to the musculoskeletal disorder related to the bio-psycho-social sphere [11,27,52].

Classification Based on Onset of Symptoms
The psycho-social sphere seems to have a key role in developing the central sensitisation (CS) phenomenon in subjects with LEP. The CS phenomenon is directly associated with the onset of a disturbance in the musculoskeletal structure (low-back pain, cervicogenic headache, LEP) and is more recurring in subjects showing symptoms for three months or more [53]. In the inclusion criteria of the 227 RCTs, only 42.1% of the studies included patients with symptoms lasting more than three months. That means that the remaining articles (39.4% with symptoms < 3 months and 18.1% with non-specified temporal criteria) structured the RCTs based on a group of patients that was not homogeneous for the symptoms' onset, the related psychosocial associations, and, therefore, the presence or not of the CS phenomenon. That could have modified the response of some subjects to the proposed interventions, causing a background bias that invalidates the quality and the results of the study itself.

Diagnostic Test in LEP
The literature-based and clinical approach mainly uses provocation tests that exacerbate the epicondylar pain to diagnose in the case of suspected LEP.
In  [18]. Furthermore, clustering these two tests might further increase their reliability. Literature about psychometric values of other tests is quite weak, so they should be studied further. The PFGST was administered in 19.0% of the cases and represents a valid instrument for the assessment of the load's tolerance and the excitability of the elbow with a high reliability (ICC > 0.97) and a minimal clinical importance difference (MCID) of 7 kg, representing an 18% change of the mean normative value [27,45,54,55]. ULNT2B was proposed in two RCTs included to analyse the presence of an entrapment of the radial nerve at the level of Frohse's arcade or inside of the brachioradial muscle [56,57]. In this regard, other tests have been proposed in the literature to evaluate the presence of peripheral nerve entrapment in LEP, such as the Rule-of-Nine test [58].
Most of the tests mentioned in the studies aim to elicit a symptom that recalls an insertional tendinopathy of the extensors of the wrist and fingers, but they do not allow for a differential diagnosis with other causes of LEP such as radial nerve entrapment and intra-articular pathology.
In fact, the studies showed that several cases of persistent LEP were related to a high incidence of intra-articular alterations caused by a condition of ligamentous microinstability at the radial capitellum level. (S.M.I.L.E., symptomatic minor instability of the lateral elbow) [59,60]. Several cases of LEP revealed a ligamentous laxity of the radial component of the radial collateral ligament and/or of the radial annular ligament that lead to phenomena of synovitis and/or chondropathy at the radial capitellum level (CLAC lesion, "chondropathy of the lateral aspect of the capitellum"). From a diagnostic and prognostic point of view, it would be useful to start considering the intra-articular issue in the assessment of LEP to create a reliable and efficient procedural algorithm for identifying the main pain generator and for the treatment of this symptomatology. This kind of approach would allow for different management of cases of persistent LEP that have not shown improvement after the suggested rehabilitative treatment and that still show disability and restrictions in movement.

Lateral Elbow Disorders: A New Proposal
Following the previous paragraphs, we believe that the time has come to find, through a common language, a definition to better describe the disorders of the lateral part of the elbow. According to the authors, lateral elbow disorders (LEDs) seems the most appropriate term to describe them. Furthermore, we want to propose the use of more current tools for a clinical setting, capable of identifying specific subgroups of LEDs that (A) help to determine more carefully the description of signs and symptoms of patients suffering from lateral elbow pain, (B) respond to different prognosis and outcome times of the proposed treatments and their relative impact on the psycho-social aspects of the patient, and (C) in the presence of a high predominance of yellow flags, the patient should be monitored and educated, thus modifying any dysfunctional beliefs and overestimated expectations about elbow pain and reconceptualising, on a cognitive level, any fear, harm, and avoidance about elbow activity [61]. In this regard, we believe it is fundamental that the clinical framework follow a rational construct capable of: (1) Analysing any red flags to analyse the presence of situations that imply a nonmusculoskeletal problem. In this case, the patient needs to be referred to the doctor for the most appropriate diagnostic investigations (screening for referral) [62][63][64][65]; (2) Guiding the clinician in determining whether there is a structure predominantly involved in and responsible for the lateral musculoskeletal disorder of the elbow (muscle-tendon, joint, neural) capable of influencing the prognosis and the type of treatment (conservative and/or surgical); and (3) Recognising profiles of patients who, depending on the time of suffering, may present the risk of developing yellow flags capable of slowing down or altering the treatment process and/or deteriorating adherence to the therapeutic plan.
Following an evaluation algorithm proposed in a previous publication with the I-APPLEp algorithm [11], we believe that replacing the term "LEP" with "LEDs" is necessary. Our main goal is to describe and identify the lateral problems of the persistent-recalcitrant elbow-longer than three months-as an alternative to the old labels, among which are "epycondilitys," "tennis elbow," and "epycondilalgia." Accordingly, we propose a modified version of the I-APPLE algorithm: LED-APP, the Lateral Elbow Disorders Approach (reported in Figure S1). It considers four possible subgroups of clinical pictures caused by three main anatomical complexes responsible for signs and symptoms, responding to different treatment principles and prognostic times. Namely, the algorithm includes the following as subgroups: The rationale for the new LED-APP assessment and treatment framework provides different steps of clinical assessment. In Clinical Assessment 1, we evaluate the involvement of the tendon component and the relative pain reported by the patient through the tendon load tests suggested by the literature as the most sensitive (rule out: Cozen test, Maudsley test, pain-free grip-strength test) [8,27]. The minimal clinical importance difference (MCID) of PFGS has been reported to be 7 kg in patients with LEP and represents an 18% change in the mean normative value of grip strength (38.4 kg) for men and women aged 40-50 years [27,45,54,55].
In case of positivity of these tests, we consider the clinical picture with tendinopathic prevalence (T-LED), and the treatment will be oriented towards desensitising pain with manual therapy and exercise and improving the load tolerance (load capacity) of the whole muscle-tendon system with progressive therapeutic exercise with a prognostic perspective of 4-6 weeks [66][67][68][69].
In case of failure of the conservative approach (NPRS <2 points, DASH <10 points, PRTEE <10 points), we consider it useful to refer patients to an orthopaedist. The main aim is to offer diagnostic imaging (Msk-US imaging, X-ray, MRI) and choose the most appropriate therapeutic path up to possible surgery [11]. In case of a negative Clinical Assessment 1, we will move on to Clinical Assessment 2, in which we evaluate whether the symptoms reported by the patient are attributable to joint pain through the direct provocation of the humero-radial joint structures with two provocative tests: SALT (supination antero-lateral pain test), proven to be sensitive and accurate for pictures of synovitis and anterior patolassity, and PEPPER (posterior elbow pain by palpation-extension of the radiocapitellar joint), proven to be sensitive and accurate for pictures of radial head chondropathy [70]. If these tests are positive (ad one of the two tests), the clinical picture will be considered a prevalent lateral elbow disorders (A-LED) with characteristics attributable to the clinical picture of SMILE (symptomatic minor instability of the lateral elbow) [59] and the treatment will be oriented to the protection of the joint component with the use of splints, braces and/or ban-dages, and manual therapy techniques of arthrokinematics [71] for pain control and intense therapeutic exercise with a prognostic outlook of 12-16 weeks [22,42,71]. In case of failure of the conservative approach (NPRS <2 points, DASH <10 points, PRTEE < 10 points), we consider it useful to refer patients to the orthopaedist. The main aim is to offer diagnostic imaging (Msk-US imaging, X-ray, MRI) and choose the most appropriate therapeutic path up to possible surgery [11].
In case of a negative Clinical Assessment 2, we will move on to Clinical Assessment 3, which assesses whether the patient's symptoms are attributable to neural entrapment phenomena in Frohse's arch (NIP syndrome or radial tunnel syndrome) or entrapment to the intermuscular septum between the extensor radial long carpus and the brachioradialis (Wartemberg syndrome) through clinical tests such as ULNT2b. If positive, proceed with two further tests: the Rule-of-Nines test and the Tinel test; in case of positivity to at least one of the two, the clinical picture will be considered a neural prevalence of lateral elbow disorder (N-LED) with the related sub-declinations. Thus, the treatment will include a manual therapy approach composed of neurodynamic and myofascial techniques associated with dynamic thermoplastic splints, ESWT, neurodynamic sliding or tensioning techniques, and dynamic stretching, with a prognostic perspective of (4) 8-12 weeks [72]. In case of failure of the conservative approach (NPRS <2 points, DASH <10 points, PRTEE <10 points), we consider it useful to refer patients to the orthopaedist. The main aim is to offer diagnostic imaging (Msk-US imaging, X-ray, MRI) and choose the most appropriate therapeutic path up to possible surgery [11].
In case of a negative Clinical Assessment 3, the signs and symptoms will be attributed to clinical pictures on a mixed basis (Mixed Form: M-LED), which should be approached and considered according to the clinical picture of reference. On the other hand, if the anamnestic collection and the description of the signs and/or symptoms are attributable to an uncommon specific problem, such as a possible expression of important and/or serious problems (e.g., trauma, fever, weight loss, infection, recent surgery, systemic disease, fracture, tumour), it is essential to refer back to the specialist for clinical and diagnostic study (screening for referral).

Limits
The SRs were selected through the RoBis tool to assess the risk of bias; this tool should not be used to generate a summary "quality score" because of the well-known problems associated with such scores. Therefore, the pooling of SR data does not present a cut-off for the quality screening of the articles. Inter review blindness was not maintained in the full-text analysis of the selected studies.
The authors are aware that the type of studies selected is not the best for evaluating a clinical condition's taxonomy, classification, or diagnostic criteria. However, the choice to select systematic reviews of RCTs seemed a much more clinical and pragmatic choice to the authors. Since RCTs are the best studies to evaluate the best treatment, we started from this type of study to understand how these studies made diagnoses, which tests they relied on, and what they called these clinical conditions of LEP.
In future studies, this analysis of the literature could be helpful to analyse the reliability of clinical tests for patients with LEP and create a new algorithm of assessment and diagnosis. Lastly, quality studies to test its clinical efficacy are required to apply a structured and rigorous validation course.

Consistency
In the literature, to date, the terminological framework of this problem is confusing [73]. Therefore, there is a need for standard and internationally accepted definitions for LEP. LEP is defined as an overuse injury due to an unbalance between the resistance capacity of connective tissue and the biomechanical solicitations on the lateral aspect of the elbow [1][2][3][4][5][6][7]9]. Furthermore, pain is not the only symptom complained of by the patient, but is often associated with disabilities, functional impairments, and loss of social, sports, and work participation [9][10][11].
Therefore, in our view, a more suitable word may be "disorder" (lateral elbow disorders-LEDs), which better describes multifactorial conditions, which include, besides structural aspects, psychosocial elements often present in nonspecific painful disorders like LEP [5,6,9,10].
Our SR confirmed the findings for LEP, like in recent literature, which concluded that the evidence about the terminology of LEP is scarce and derived from studies not of good methodological quality [47][48][49]74,75]. This SR showed a quite high prevalence among studies of the term "LEP," but this finding, albeit relative to a wider sample of patients, does not specifically include accurate reasons to adopt this term exclusively.

Conclusions
LEP includes a wide range of inflammatory and degenerative conditions affecting the muscles, tendons, ligaments, joints, peripheral nerves, and supporting blood vessels. These include clinical syndromes such as intra-articular and ligament disorders, tendinopathy, and peripheral nerve compression pathology.
In this SR, the terminological analysis of LEP that was carried out shows the need for "tidying up" within the wide range of terms and descriptions related to this symptomatology. The lack of clarity from a terminological point of view has led clinicians and researchers to define these symptoms with different terms, shifting from a traditional biomedical view to a biopsychosocial one, without determining a univocal term shared by everyone that could describe the pathology clearly and correctly. Furthermore, not even at the diagnostic level is there currently a validated and reliable cluster of tests in the literature that allows for the distinction between extra-articular-based symptomatology and an intra-articular-based one in a patient with LEP to define a suitable pathway of treatment.