Ulnar-Side Wrist Pain Management Guidelines: All That Hurts is Not the TFCC! (2024)

Abstract

Keywords: Ulnar-side wrist pain, Storey concept, Lunotriquetral injury, Wrist arthroscopy

Introduction

Ulnar-sided wrist pain is a commonly seen clinical problem with a litany of etio-pathology. It often poses a diagnostic and therapeutic dilemma to the treating surgeon. Patients suffer from debilitating pain and loss of function. Knowledge about the anatomy and pathologies that may involve the ulnar side of the wrist is essential, to diagnose and formulate an appropriate treatment plan. Although a clear definition of the ulnar side of the wrist is not present in the literature, one can arbitrarily consider the line of the radial border of the 4th ray (ring finger) extending up to the proximal wrist crease as the demarcation of the ulnar side of the wrist joint.

Causes of ulnar-side wrist pain can be broadly classified based on the tissue from where the pain is arising [1]. It is easier to begin the assessment sequentially, by asking the patient to point out the most painful site on the wrist. Knowledge about the anatomy of the ulnar side of the wrist is essential for accurate diagnosis (Fig.1). The knowledge of the surface anatomy and various tests will be key to the diagnosis (Fig.2).

A thorough history and clinical examination is critical to diagnose the cause of ulnar-sided wrist pain. A detailed description of several conditions causing the ulnar-sided wrist pain is beyond the scope of this article, emphasis will be mainly on evaluation and the differential diagnosis of ulnar-sided wrist pain. There are various aspects one has to remember while doing an assessment like what are the most probable causes, the anatomic structures injured, and the mechanism of injury. It is probably simple to enumerate the causes of ulnar-sided wrist pain as frequent, occasional and rare as mentioned in Table ​Table11.

Detailed history should include dominance of hand, repeated actions involved and vocational activity. Some of the key points in history taking can lead us to diagnosis like the mechanism of fall, for example hyperpronation and dorsiflexion can cause distal radioulnar joint (DRUJ) or triangular fibrocartilage complex (TFCC) injuries. It is essential to ask certain leading questions such as, whether is it pain alone or pain with instability and if it is associated with arthritis, as this will enable in decision making [1]. A gymnast or an athlete using a racquet or bat are at particular risk because of the forceful torque transmitted across the wrist joint [2]. To clinch the diagnosis, it would be prudent to know if the onset of pain is acute or insidious, or is it associated with increase in pain on loading, or aggravates in specific forearm rotation or ulnar deviation. Pain worsening with heavy grip or in pronation and ulnar deviation is likely to be ulnocarpal impaction syndrome [3]. The natural history of the TFCC tear without instability shows that nonsurgical modality is moderately successful and this has to be borne in mind when planning the treatment [4].

Algorithms to Diagnose

Considering the labyrinthine nature to arrive at a diagnosis, various algorithms have been proposed. Brogan et al. suggested a simple mnemonic, RUPERT to remember the anatomic components. R stands for sigmoid notch of the radius, U for ulnocarpal ligaments, P for pronator quadratus, E for extensor carpi ulnaris (ECU) and its subsheath, R for radioulnar ligaments and T for TFCC [1]. Kakar et al. suggested an algorithm for managing distal radioulnar issues by applying the four leaf clover algorithm [5]. The treating doctor examines the patient and with the support of imaging modalities, following four questions are answered:

1. Presence of bone deformity and or radioulnar length discrepancy?

2. Cartilage defect?

3. TFCC injury?

4. Easily subluxatable ECU tendon?

Whenever a combination of the above pathologies are suspected, a Venn diagram is drawn with each of the above four questions representing a circle. Combination of treatment is planned, which best represents the overlapping area. However, caution must be exercised when multiple procedures are required and the surgeon should plan an operation which expeditiously addressees the problem by a single procedure [5].

The authors look at ulnar side of the wrist joint as a three-storey model, with the ulnar styloid in the intermediate storey, serving as a key land mark (Fig.3) (Table ​(Table2).2). It is easy to palpate ulnar styloid, and begin to assess the cause of pain distally and proximally, with diligent care to be taken so that we palpate the most painful site at the end. The lower storey identifies the pathologies of the DRUJ, the intermediate storey identifies the pathologies of the radiocarpal joint and the upper storey identifies the pathologies of midcarpal and carpometacarpal joint.

Investigations

Plain radiographs, dynamic radiographs, CT scans and MRI investigations are critical which complement the clinical assessment. Ultrasound has some role but is highly operator dependent. Radiographs of the wrist in true posteroanterior (PA) view and lateral view are commonly performed to look for fractures, erosions, arthritis and lytic lesions. True PA and lateral views of both the affected and contralateral forearm will be helpful, when suspecting a forearm deformity. True PA view is done by placing the shoulder at 90º of abduction and the elbow at 90º of flexion and a true lateral radiograph is obtained with the arm at the patient’s side and the elbow flexed 90º. Oblique views in 30º pronated views are useful to visualize the dorsum of ulna and 30º supinated views are useful to visualize the pisotriquetral joint. Carpal tunnel views are done with wrist in 35 º of dorsiflexion and the X-ray beam is tangential to the anterior aspect of the wrist, this view enables visualization of hook of hamate, pisotriquetral joint. With use of arthroscopy, the role of arthrography is reducing in view of high false negative reports [6].

Fluoroscopy is useful to assess the dynamic instability which shows the abnormal movements of the carpal, in patients who complain of sudden shift or clunk with the wrist deviation. Catch-up of the triquetrum moving in to extension is seen when the wrist moves from radial to ulnar deviation in lunotriquetral (LT) ligament injury.

CT scan is useful in diagnosing occult fractures of hamate, pisiform, DRUJ instability. For DRUJ instability, both wrists must be evaluated with forearm in identical positions for comparison, also it may be necessary to image in neutral, supination and pronation positions as well. Ultrasound is preferred to diagnose tendinitis, and dynamic conditions like subluxating ECU.

High-resolution MRI, preferably a three Tesla MRI is used as they have increased diagnostic capability. MRI is useful to diagnose TFCC tears but its sensitivity and specificity are inconsistent when compared with various studies. Subtle instabilities of the wrist and DRUJ can be identified by dynamic wrist imaging with MRI or CT. Tendinopathies show thickening of the tendon with signal changes both in T1- and T2- weighted images. Magnetic resonance arthrography (MRA), both direct and indirect are useful, TFCC perforations appear as high signal fluid on fat-suppressed T1-weighted images, traumatic tears will have contrast material in DRUJ. Direct MRA is cumbersome, whereas indirect MRA is dependent on vascular perfusion and can be misleading, neither of them have proved superiority over the other. MRI also provides information about the vascularity of the lunate and ulnar head, useful to differentiate ulnocarpal abutment and Kienbocks disease, which shows diffuse signal changes, whereas abutment shows focal signal changes [1].

Wrist arthroscopy allows us to confirm, identify the location and patterns of TFCC tears and is considered as “Gold Standard” for diagnosing TFCC tears. Simultaneously, wrist arthroscopy allows us to diagnose tears of the lunotriquetral interosseous ligament or other intra articular pathologies, with the benefit of performing therapeutic procedures at the same time.

Causes

Ulnocarpal Impaction Syndrome

Ulnocarpal impaction syndrome is a condition when there is pain on loading of the wrist due to abutment of the distal end of ulna or TFCC to carpus [14]. It is usually a triad of positive ulnar variance, TFCC and LT ligament tear [15]. Force transmission across the scaphoid fossa, lunate fossa and distal ulna is 50%, 35% and 15%, respectively, in neutral position of the wrist [16]. Ulnocarpal impaction syndrome can exist even in a neutral or negative ulnar variance. Axial load borne by ulna increases by 18.4–41.9% when ulna is lengthened by 2.5mm and reduces to 4.3% when shortened by 2.5mm [17].

Typically pronated and forceful grip is painful. Increased ulnar variance causes primary ulnar impaction, acquired causes are malunited distal radius fracture with shortening, distal radius physeal injury, Galeazzi fractures and following radial head excision [15]. Madelung deformity is a congenital cause. Typically, they have tenderness over lunate and ulnar head. Ulnocarpal stress test is a useful provocative test described by Nakamura, it is considered positive if there is pain on axial load on an ulnar-deviated wrist that goes through pronation and supination [18]. This test can be positive in TFCC tears, LT injury, ulnocarpal impaction, it is sensitive but not specific. Radiographs shows positive ulnar variance with sclerosis, subchondral cysts in lunate, triquetrum and sometimes kissing lesions (Fig.5) [19]. MRI shows subchondral sclerosis as areas of low signal intensity on T1- and T2- weighted images, whereas subchondral cysts are seen as well-defined low signal intensity in T1- weighted and T2- weighted images are seen as high signal intensity [20].

Conservative treatment includes splinting and anti-inflammatory. Ulnar variance has to be assessed, ulnar shortening and wafer procedure are commonly done. Ulnar shortening is preferred if more than four millimetre of shortening is required [21]. Disadvantages include hardware prominence, but cannot be done in presence of DRUJ arthritis. Aim of arthroscopic wafer procedure is to produce two millimetre of negative ulnar variance [15]. Arthroscopy helps to assess the cartilage damage, TFCC tears, LT ligament tears and this can be addressed at the same time. Bernstein et al. compared arthroscopic TFCC debridement with wafer resection versus ulnar shortening osteotomy and found that both provide similar pain relief, restoration of function with fewer secondary procedures [22]. Distal metaphyseal shortening osteotomy of the ulna can be done as an open procedure as described by Slade and Gillon or arthroscopic procedure as described by Yin et al. [23].

Ulnar Styloid Impaction Syndrome

Ulnar styloid impaction syndrome is a much rarer condition than ulnar impaction syndrome, both of which produces pain on ulnar side of the wrist with subtle differentiating points clinically. The ulnar styloid impaction syndrome is due to impaction of the triquetrum against the elongated ulnar styloid, causing chondromalacia, synovitis and ulnar-sided wrist pain. In early stage, the interposed TFCC and a soft tissue impingement occurs but later, once the TFCC has eroded due to repetitive movements, the tip of the ulnar styloid directly contacts the dorsal aspect of triquetrum when the forearm is in supination, wrist extension and ulnar deviation. Here, the tenderness is directly on the tip of the ulnar styloid, dorsal aspect of triquetrum and the pain aggravates on ulnar deviation and supination, which is differentiating from ulnar impaction syndrome, wherein the tenderness is over the ulnar head, lunate and pain aggravates in ulnar deviation and pronation. Ulnar variance is neutral or negative with kissing lesions on the ulnar styloid and triquetrum. MRI shows sclerosis on tip of the ulnar styloid and chondromalacia on the triquetrum (Fig.5).

Hamatolunate Impaction Syndrome

This is a rare cause of ulnar-sided wrist pain, occurs because of repeated impaction between the proximal pole of hamate and lunate and is commonly seen in an anatomic variation of lunate type 2 Viegas [24].

Lunotriquetral Instability

Lunotriquetral injuries can be acute or chronic, isolated LT injury can occur by a dorsally applied force on a palmar flexed wrist. Whereas perilunate injury is usually fall on an outstretched hand with dorsiflexed and ulnar deviated wrist and the impact on the thenar eminence [25]. Tenderness directly over the LT ligament is the most common finding. Other commonly elicited tests are triquetrum ballotment test described by Regan et al., wherein the pisotriquetrum is held between thumb of index finger of a hand, whereas the lunate is grasped with the other hand and Ballotment is done. A positive test will elicit an increased anteroposterior laxity with pain [26]. Kleinman’s shear test is performed with forearm in neutral rotation, the examiners contralateral thumb supports the lunate on dorsum, while the ipsilateral thumb of the examiner loads the pisotriquetral joint from the palmar side, if the shear force produces pain, crepitus and abnormal mobility of the LT joint, it is considered to be positive [25].

Radiographs of LT tears rarely show a gapping unlike SL injuries. Lateral views are very useful to detect the VISI deformity and also the relative angle between the lunate and the triquetrum. Owing to huge variations in sensitivity and specificity of MRI findings, MR arthrography should be preferred as it can show the contrast material across the defect in the LT ligament into radiocarpal joint from midcarpal joint [20]. Many surgeons prefer arthroscopy, as it allows to visualize, feel and also to repair the ligament (Fig.6). It also provides information on concomitant injuries to TFCC and chondral injuries [25].

Conservative mode of treatment is usually immobilization, preferably a cast with optimal alignment of lunate for 6 weeks for isolated partial LT ligament injury. Steroid injection to midcarpal joint if it is associated with synovitis. Primary repair of the ligaments by bone tunnels or using anchors can be done and stabilise the repair with k wires. Even dorsal capsulodesis has been proposed in severe cases [27].

Geissler et al. proposed an arthroscopic classification of intracarpal ligament injuries and graded into four categories, arthroscopic treatment was suggested up to grade three and open repair recommended for grade four [28].

Tendinopathy

Tendinopathies of ECU FCU and extensor digitorum minimi, are the commonly seen on the ulnar side of the wrist.

Nerve Injuries

Dorsal cutaneous branch of ulnar nerve can cause painful neuroma and can be the cause of ulnar-side wrist pain, acute laceration on the ulnar side of the wrist should not be ignored and sensation should be carefully assessed to prevent an unmindful cause of pain.

Neoplasms and Vascular Lesions

Although a rare cause of pain, neoplasms or cysts of the triquetrum, distal ulna and hamate should be borne in mind, few conditions to mention are simple bone cyst and giant cell tumour. Simple radiographs or MRI scans would help the diagnosis.

Conclusion

A detailed knowledge on anatomy, surface marking, locating the site of pain with reference to ulnar styloid will help us to arrive at a clinical diagnosis and all that hurts on the ulnar side may not be TFCC injury.

Diagnostic dilemmas in ulnar-sided wrist pain can be sorted out by methodical steps of wrist arthroscopy. There is a significant increase in the use of wrist arthroscopy as it allows to diagnose, stage and treat at the same time. Some of the conditions like LT ligament injury, loose bodies and chondral lesions, which can be missed by MRI [33]. Both radiocarpal joint and midcarpal joint has to be visualised. We would like to stress that if one encounters a significant finding in radiocarpal joint like TFCC tear or chondral lesions of triquetrum or lunate, then it is imperative to do inspect the midcarpal joint.

Compliance with Ethical Standards

Footnotes

Contributor Information

Darshan Kumar A. Jain, Email: moc.liamg@18nahsradniaj.

Abhijeet L. Wahegaonkar, Email: moc.liamg@ehawihba.

References