Lateral epicondylosis is one of the most common causes of lateral elbow pain associated with diminished grip strength, painful gripping, painful resisted wrist extension, radial deviation, extension of the middle finger and pain with palpation over the lateral epicondyle at the origin of the extensor carpi radialis brevis (ECRB) [1] - [6] . Treatment begins with bracing, icing, non-steroidal anti-inflammatory medications, corticosteroid injections, activity modification, resistance training, ergonomic evaluation and physical therapy [3] [7] . It is well established that lateral epicondylosis may take 3 - 12 months to resolve, leading to frustration for both clinicians and patients. The delay in resolution of symptoms may simply be the natural course of the disease; however, it also could be related to an inaccurate diagnosis. There are several pathologies that afflict the lateral elbow including: posterior interosseous nerve entrapment, posterolateral rotatory instability, plica syndrome, Panner’s disease, radiocapitellar joint chondromalacia, degeneration, osteochondral fracture, loose body, osteochondritis dissecans or cervical dysfunctions [8] [9] [10] . It is therefore important for clinicians to have knowledge of the anatomy of the elbow complex and the pathophysiology of associated conditions in order to make an accurate diagnosis and propose appropriate plans of care.

Cadaveric, arthroscopic and imaging studies suggest that lateral elbow pain can present with and without involvement of the extensor muscle group. Goodfellow and Bullough [11] first described post mortem evidence of articular cartilage degeneration within the elbow complex. They reported that observed degeneration appeared to be age dependent and primarily reserved to the humeroradial joint (HRJ) [11] . Various authors [8] [12] [13] have used arthroscopy to evaluate patients who presented clinically with chronic lateral elbow pain resistant to conservative care. Rajeev et al observed that 59% of patients who reported additional symptoms of locking (25%), crepitus and stiffness (45%) also exhibited articular cartilage degeneration, with 88% of those patients exhibiting degenerative changes exclusively within the HRJ [13] . Degenerative changes within the HRJ were found within the radial head in 68% of patients and within the capitulum in 69% of patients. Observed degeneration varied from Grade 1 - 3 and included partial and full thickness tears. Only 36% of patients exhibited extensor origin inflammation. Other pathological findings included radial head plica (16%) [13] , synovitis (55% - 84%) [8] [12] [13] , loose body (7.1% - 16%) [8] [12] [13] , adhesions (4%) [13] , valgus extension overload (5%) [8] [12] and osteophytes (12% - 14%) [8] [12] [13] .

The clinician begins to develop a working diagnosis based on the patient’s history and clinical examination prior to including more expensive and/or invasive diagnostic procedures. However, presently there is not a valid and reliable clinical test, which can be utilized to differentiate between lateral elbow pain secondary to extensor tendopathy and/or arthropathy. Plain radiographs often fail to assist in excluding involvement of unicompartmental lateral degeneration [13] in patients with chronic lateral elbow pain. The following case study demonstrates how including the HRJ distraction and the HRJ plica tests within the clinical examination of a patient with chronic lateral elbow pain allowed for early diagnosis and management.

A 38-year-old left hand dominant male (185 cm, 99.79 kg) competitive and recreational athlete (weight lifting, long distance cycling and marathon runner) presented to physical therapy via direct access with complaints of left lateral elbow pain. He reported a bicycle accident 7-months prior where he rolled across the hood of a vehicle striking his left elbow on the hood and then landing on the pavement on his feet. Initially he reported acute elbow pain, without impaired function which resolved within a few weeks. However, more recently he began complaining of recurrent pain, loss of elbow range of motion (ROM), crepitus and intermittent painful locking when performing certain workout activities. Locking was associated with sharp pain and inability to fully extend the elbow. The patient relieved symptoms of locking with active ROM of the wrist and forearm. Following an incidence of locking, the pain occurred with simple grasping pad to pad as well as movement of the elbow. Pain remained elevated for a few weeks limiting his ability to participate in any upper body weight lifting. The pain was described as sharp in nature over the lateral aspect of the elbow with worst/least intensity ratings of 7 out of 10 and 2 out of 10, respectively, using the numeric pain rating scale. Disability was measured using the Disability of the Arm Shoulder Hand Questionnaire (DASH) [14] . The score was 13.33% out of 100%, where 100% indicates total disability. The DASH Sport Module was 68.75%. The patients’ past medical history was otherwise unremarkable.

Arthroscopic exploratory surgery is often recommended for chronic lateral elbow pain resistant to conservative management; however, patients who present with pain in the absence of a positive clinical examination and radiographic

findings benefit least from arthroscopic evaluation [18] . This single case report is the first to propose the use of new clinical tests to assist in differentiating between etiologies of lateral elbow pain. The tests included the HRJ distraction test and HRJ joint plica compression test. Clinical findings were then confirmed with imaging and arthroscopy.

Plain radiograph, CT and MR arthrography have shown little success in assisting in diagnosis of Grade 1 or 2 chondral changes [13] [18] [19] . However, Waldt et al found that the use of CT and MR arthrography to be equally sensitive and specific (87/94% and 85/95%, respectively) in detecting Grade 3 and 4 lesions [19] . Rajeev et al also concluded that the presence of a normal plain radiograph was not relevant in excluding the diagnosis of arthropathy [13] because radiographs failed to detect early signs of joint arthrosis. Additionally, the use of plain radiograph, CT and MR arthrography were found to lack reliability and accuracy in diagnosing the presence of loose bodies. When compared to arthroscopic evaluation, radiography was often unable to distinguish between an osteophyte and loose body and unable to detect whether the particle was intra or extra articular [18] [19] . These authors also concluded that CT and/or MR arthrography were not any more effective than plain radiograph in diagnosing a loose body (overall sensitivity 88% - 100% and specificity 20% - 70%). Therefore, to avoid unnecessary surgical and expensive diagnostic procedures in the absence of a definitive clinical examination, an accurate clinical diagnosis through the use of valid and reliable tissue differentiation tests is suggested. In this patient case the clinician hypothesized the presence of a HRJ pathology. This was based on the patient history of trauma, loss of range of motion and painful locking in the elbow. The application of the HRJ plica compression and HRJ distraction test supported the clinicians reasoning, directed initial care including a loose body manipulation of the elbow and later need for referral to an orthopedist to confirm diagnosis when effects of the initial intervention plateaued. Diagnostic imaging confirmed the suspicion of HRJ pathology as well as loose body.

A few studies examined the relationship between the diagnosis of lateral epicondylosis and the presence of radiocapitellar joint degeneration [11] [13] [20] [21] [22] [23] . Quintart et al [24] found during surgical examination of 17 patients that 65% of the patients exhibited extension limits of the elbow and 53% of patients displayed radial head chondropathy [24] . More recently Sasaki et al performed a retrospective evaluation of 31 patients who had undergone arthroscopic surgery secondary to recalcitrant lateral epicondylosis. All patients’ diagnoses were based on a history of lateral elbow pain, pain with resisted wrist extension and palpation over the lateral epicondyle. All subjects exhibited increased MRI signal intensity of the ECRB at its origin, but did not exhibit evidence of HRJ or humeroulnar joint arthropathy. Evidence of cartilage injury was observed later during arthroscopic evaluation; capitellum (65%) and radial head (81%). Capitellum degeneration has also been independently associated with the absence of ECRB tear in persons with lateral epicondylosis [23] .

Resistance testing and soft tissue length assessments are common clinical tests performed during a musculoskeletal examination to assess tolerance of the musculotendinous components to stress and strain. When examining the wrist extensor group in patients with lateral elbow pain, the authors propose pain during resistance testing or gripping, could be secondary to either dysfunction of the musculotendinous unit or increased compressive forces within the HRJ. To assist in tissue differentiation, the HRJ distraction test was proposed by authors. The test assesses the change in pain during resisted wrist extension with and without HRJ distraction. It is hypothesized that the addition of a traction force applied to the radius would have no effect on pain of musculotendinous origin but would decrease or eliminate pain of osteocartilagenous origin secondary to decreased compressive load within the joint. In this patient case elbow arthroscopy confirmed the absence of extensor muscle group involvement and presence of Grade 3 chondral changes of the humeral head. Therefore, the addition of the HRJ distraction test in this patient case, assisted the clinician in differentiating between impairments of the wrist extensor group from HRJ arthropathy.

Many researchers have proposed that the plica [24] and synovial fold [25] - [30] may contribute to lateral elbow pain. Quintart et al [24] observed during surgical exploration that 76% of patients diagnosed with lateral epicondylitis exhibited evidence of a plica within the HRJ. Duparc et al [25] found the presence of a synovial fold within the HRJ in 86% of the 50 cadaveric specimens examined. When Duparc et al [25] compared cadaveric specimens to five live subjects who had recently undergone surgery for epicondylalgia they found that the resected synovial fold exhibited signs of inflammation, increased thickness and numerous nerve fibers as compared to the cadaveric specimens. Clarke [28] found in his surgical exploration of patients diagnosed with a loose body that it was actually the presence of a fibrotic synovial fringe impinged within the HRJ that caused catching, locking and pain rather than a loose body [28] .

Since synovial plica syndrome presentation is similar to lateral epicondylosis, careful evaluation for proper diagnosis is warranted. Some authors have palpated a snapping plica around 80 - 110 degrees of elbow flexion as the elbow is moved from supination and extension to pronation and flexion in 25% - 50% of patients [29] [30] [31] . Many tests and measures can cause irritation of the synovial fold or plica at the HRJ; therefore, the authors suggest the inclusion of HRJ plica test to assist with differentiation. The test purports to compress the plica and or synovial fold within the HRJ space during passive elbow extension, producing lateral elbow pain. Also, in the presence of a hypertrophic plica or posterior capsule, the clinician’s palpating finger will be pushed out of the indentation created by the HRJ line when the patient’s elbow is fully extended. When symptomatic, a plica or synovial fold may be treated with an injection, iontophoresis with dexamethasone, loose body manipulation and/or surgical resection [24] [25] [29] [30] . In this case, the patient responded well to a loose body manipulation; it is therefore plausible that the plica became impinged within the HRJ during active or passive extension motions. The presence of a HRJ plica was observed and resected during arthroscopic exploration.

Although this case review is limited by a single case design, it is the first report providing confirmation of the clinical findings of a HRJ distraction and compressive test using imaging and arthroscopic exploration in a patient case where a HRJ lesion and hypertropic plica were suspected. Prospective studies are needed to determine the predictive validity of the HRJ distraction test and HRJ plica test to assist in differentiating between lateral elbow pain secondary to extensor tendopathy or radiocapitellar joint arthropathy.

The authors declare that there is no conflict of interest regarding the publication of this article. Informed consent was obtained from all individual participants included in the study.

Jonely, H., Brismée, J.-M. and Lutton, D. (2018) A Clinical Test for Diagnosis of Humeroradial Joint Lesions in the Presence of Lateral Elbow Pain: Single-Case Design with Arthroscopic Confirmation. International Journal of Clinical Medicine, 9, 162-174. https://doi.org/10.4236/ijcm.2018.93014

Video. Instructional video for the performance of the “Humeroradial Joint Distraction Test”, “Humeroradial Joint Plica Test” and “Loose Body Manipulation of the Elbow”. This information will allow the reader to more accurately apply the psychomotor skill associated with the performance of these tests and intervention (https://youtu.be/ObVXC9yKTIg).