The ulnar side of the wrist is composed by a large number of structures that allow us to be functional, and to perform activities as diverse as weight bearing (such as push-ups exercise or leaning on an armrest for getting up, etc.) or delicated gestures (writing, using small objects such as coins, etc.).

Due to this complexity, It is more necessary than ever to have a thorough knowledge of the anatomy of the carpus and its biomechanical implications. Only in this way will we be able to make a correct assessment of the region and obtain an accurate diagnosis of the patient’s problem.

We recommend that you take a look at Part 1 of this Blog, where we set out the basic principles before carrying out any kind of wrist assessment: ✅​Principles of a successful diagnosis of the wrist.

Also, remember that we have two complementary entries to this one: ✅Differential diagnosis of the Radial-Side Wrist Pain and ✅Central-Side Wrist Pain.

Diagnosis Tests for the Wrist Pain | Ulnar-Side

Lunotriquetral Ligament Injury

The Lunotriquetral ligament, as its name suggests, is one of the intrinsic carpal ligaments that joins the lunate and triquetrum bones of the first carpal row. It is a vital structure for the precise and correct forces transmission between the carpal bones and rows, so that wrist movements can be performed.

This injury is usually associated with falls with the hand outstretched backwards (as when falling backwards) together with external rotation of the shoulder, supination of the forearm, and wrist extension and radial deviation. This situation means that the ligament may not withstand the stress applied, and may be partially or completely damaged.

Together with the scapholunate ligament of the carpus, the lunotriquetral ligament maintain the balance of forces in the proximal row. So if these ligaments are damaged (together with injury to the extrinsic ligaments and neuromuscular control) what is known as carpal instability can occur.

Have a look at 👉 “Carpal Stability and Instability” where you will see everything a bit clearer.

Complete injury to the lunotriquetral ligament causes the lunate bone (and therefore the scaphoid) to fall into flexion, and the triquetrum to extension, ulnar deviation and proximal migration. This malposition is known as Volar Intercalated Segment Instability. It is characteristic to observe a deformation of the carpus in flexion.

What diagnosis test can I apply when a Lunotriquetral injury is suspected?

1) Pain on palpation of the lunotriquetral joint: in order to locate the joint, it is advisable to locate it at the dorsal level of the wrist maintaining 30º of flexion (thus exposing the joint more superficially).

The first thing to do is to place ourselves between the 4th and 5th extensor compartments (corresponding to the tendons of the extensors digitorum of the fingers and the extensor of the little finger respectively). In this line, the lunotriquetral joint is located one finger’s breadth away from the distal radioulnar joint.

2) Lunotriquetral Ballotement Test: while stabilising the patient’s wrist with one hand, the fingers of the other hand are used to grasp the triquetrum bone and exert radial pressure against the lunate. In case of pain on pressure, this test is positive.

3) Lunotriquetral Shear Test: this is another pain provoking test. In this test, while the dorsal aspect of the lunate is stabilised, the thumb of the opposite hand exerts direct pressure on the pisiform in a dorsal direction.

4) Derby manoeuvre for the lunotriquetral joint: this manoeuvre aims to reduce the malposition that occurs as a result of complete lunotriquetral dissociation (reducing flexion of the lunate and extension of the piriformis).

To do this, the examiner makes a direct dorsal pressure on the pisiform with the patient’s wrist in extension and radial deviation. Through this manoeuvre, the patient will feel a pleasant sensation of stability and will be able to increase his or her grip strength until we remove our corrective pressure.

Triangular Fibrocartilage Complex Injuries

The Triangular Fibrocartilage complex of the wrist is a structure located at the level of the distal radioulnar joint, composed of several structures: Articular Disk, Ulnocarpal Ligaments, Dorsal and volar radioulnar ligaments, and the Tendon Sheath of the Extensor Carpi Ulnaris.

The involvement of any of these structures should be suspected in cases of a history of fall or trauma associated with pain, stiffness, jumping and/or joint noises, usually related to pronation-supination movements of the forearm.

1) Piano Key Test: this test evaluates the existing stability at the distal radioulnar level, assessing the capacity of the distal radioulnar ligaments, among others.

For this purpose, the patient’s hand is placed on a table in pronation of the forearm. The assessor stabilises the distal radius with one hand, and with the opposite hand performs dorsal to volar mobilisations of the ulnar head. The test is positive if the ulna returns to its original physiological position, like the movement of a piano key after it has been released.

2) Radio Ulnar Ligament Stress Test: In this case, we will directly stress the Dorsal and Volar Radio Ulnar ligaments, which are stressed in maximum pronation and supination. These positions will be used in the test. In addition, the elbow will be kept in flexion to cancel the possible muscular involvement.

In the case of the dorsal radioulnar ligaments, the test shall be performed by placing them in maximum tension (supination) and an anterior or volar translation of the distal ulna is performed. On the other hand, the palmar radioulnar ligaments shall be tensed in the pronation position of the forearm, associating a dorsal translation of the ulna.

The appearance of marked pain or instability will be indicative of a distal radioulnar ligament injury.

3) Foveal Sign for the Triangular Fibrocartilage: this test aims to evaluate the irritability of the foveal attachments of the TFCC complex. To do this, the examiner should apply deep pressure on the distal soft spot located distal to the ulnar head, between the ulnar styloid and the tendon of the flexor carpi ulnaris. If pain is present, the test is positive.

Once we know how to assess a triangular fibrocartilage injury, how do we treat it? I tell you about it in this post:⭕ How to treat a triangular fibrocartilage injury of the wrist⭕.

Cubital impactation syndrome

Ulnar impactation syndrome is a condition which, as the name suggests, consists of excessive ulnar contact over the ulnar carpus, which can cause pain and joint damage. Patients often report pain on extension and axial loading (such as during flexion).

It is also frequently found in association with central lesions of the triangular fibrocartilage complex.

Ulnar stress test: this test looks for the appearance of pain during its performance. Thus, the patient’s wrist is placed in pronation and ulnar deviation. Then, an axial load is placed on it while performing flexion and extension movements. The test is positive in the presence of pain, although it can also occur in triangular fibrocartilage injuries.

Extensor Carpi Ulnaris Tendinopathy

The extensor carpi ulnaris muscle is another structure that can frequently cause ulnar pain in the wrist. Excessive work of this muscle can cause discomfort that refers to the ulnar aspect, such as in ECU tendinopathy.

To give an overview, the extensor carpi ulnaris tendon runs along the dorsal aspect of the ulna to its most distal end, where it passes through a tendon sheath. This sheath performs an indispensable function of stability of the ECU tendon, which guarantees its correct mechanical work of extension and pronation of the carpus. Once past this structure, the tendon reaches the distal styloid of the ulna, where it produces a pulley effect to redirect itself to the ulnar and volar carpus.

However, we may find situations in which the tendon sheath ruptures, and its function is altered. The patient will have pain and tendon snapping or popping noises during pronation and supination of the forearm.

Extensor Carpi Ulnaris Synergy Test: this manoeuvre aims to test for tendon involvement. For this, with the elbow flexed, forearm supinated and fingers extended, the examiner will perform a compression against the thumb and middle finger, requesting a radial abduction of the thumb.

With this contraction, the extensor carpi ulnaris and flexor carpi ulnaris contract synergistically to stabilise the wrist. The presence of pain along the course of the tendon will be considered positive for extensor carpi ulnaris tendinopathy.

Flexor Carpi Ulnaris Tendinopathy

In the case of the flexor carpi ulnaris, its tendon does not have its own synovial sheath at the wrist. Its tendon has a direct relationship with the pisiform bone, which is integrated into the tendon tissue itself.

For palpation, we can use the Pisiform as a reference. By positioning ourselves 3 cm proximal to the bone, we can locate the tendon. The presence of tendinopathy of the flexor carpi ulnaris may cause pain on palpation and/or resisted ulnar deviation of the wrist.

We locate: Black Arrow, Trapeziometacarpal Joint; Red Arrow, Flexor Carpo Radialis; S, Scaphoid; H, Hook of the Hamate; P, Pisiform.

In the image we can see represented the P for the Pisiform and the S for the scaphoid. The structures drawn proximally correspond to the tendons of the flexor carpi radialis (below) and the flexor carpi ulnaris (above).

Pisotriquetral Arthritis

Occasionally, due to repeated loads on the ulnar region of the wrist, joint degeneration or osteoarthritis may occur at the level of the joint between the pisiform and triquetrum bones. Their involvement often causes deep pain in the hypothenar region.

As we have seen above, the Pisiform is considered a sesamoid bone of the FCU Tendon, so its location can be used to palpate it.

Patients present with pain at the palmar aspect, which is exacerbated by direct compression together with wrist flexion (common gesture in racket sports). Pain is also found on direct palpation of the joint.

Hook of the Hamate Fracture

Another injury that can cause pain at the lateral or ulnar level of the wrist is a fracture of the Hamate bone. Specifically, it is common to find injuries to the apophysis of the bone itself, the Hook. It typically appears in isolation, associated with a direct impact on the region. Some cases can be seen in tennis and golf athletes, where the repetitive impact of the racket can end up causing some type of injury.

The resisted contraction test of the flexor digitorum profundus is used for diagnosis (together with clinical history and imaging tests). When a flexion contraction of the little and ring fingers is requested, together with ulnar deviation and wrist flexion, pressure and tension is exerted on the hook of the Hamate. This is because this structure exerts a pulley effect on these more ulnar tendons. The appearance of pain will be positive for the test.

Triquetrum Fracture

The fracture of the triquetrum bone is the second most frequent fracture of the carpus, following the scaphoid bone fractures. The Triquetrum bone is the most ulnar bone of the first row of the carpus, and has contact with the lunate, the Hamate and the pisiform.

There are three main types of fracture: Fracture of the dorsal rim of the Triquetrum bone (the most common), fracture of the body of the Triquetrum bone and fracture of the volar rim of the triquetrum bone. They can appear indirectly in the event of a fall with the wrist in hyperextension and radial deviation, which due to the traction of the posterior ligaments causes a dorsal fracture by avulsion, or directly by an impact on the ulnar aspect in wrist hyperextension.

With this last injury, we finally end our review of the main diagnoses of the wrist and the most frequent evaluation tests. Remember that we have two entries talking about pain in the central and radial side:

✅Main Diagnosis and evaluation tests for Radial-Side Pain of the wrist

✅Main Diagnosis and evaluation tests for Central-Side Pain of the wrist

ReHand for Ulnar-Sided diagnosis of the Wrist

ReHand enables us to deliver an evidence-based treatment to wrist-hand-finger segment pathologies, directly addressing the sensorimotor system with artificial intelligence. It allows us to treat and prescribe exercise programmes tailored to the pathology such as triangular fibrocartilage injuries, hook bone fractures or any of the above diagnoses.

Here is an example of a wrist flexion-extension exercise with ReHand in a patient undergoing surgery for a Hook of the Hamate fracture:

Thanks to telematic rehabilitation and the sending of validated questionnaires, it allows us to monitor our patients objectively. It also increases adherence to treatment and promotes early recovery. You can read about it in our work published in the prestigious Journal of Physiotherapy:

Blanquero J, Cortés-Vega MD, Rodríguez-Sánchez-Laulhé P, Corrales-Serra BP, Gómez-Patricio E, Díaz-Matas N, Suero-Pineda A. Feedback-guided exercises performed on a tablet touchscreen improve return to work, function, strength and healthcare usage more than an exercise program prescribed on paper for people with wrist, hand or finger injuries: a randomised trial. J Physiother. 2020 Oct;66(4):236-242. doi: 10.1016/j.jphys.2020.09.012. Epub 2020 Oct 14. PMID: 33069608.

References:

Reavey PL, Hammert WC. Examination of the Wrist. Plast Reconstr Surg. 2021;284E-294E.

Newton AW, Hawkes DH, Bhalaik V. Clinical examination of the wrist. Orthop Trauma [Internet]. 2017;31(4):237–47. Available from: http://dx.doi.org/10.1016/j.mporth.2017.05.009

Shah MA, Viegas SF. Fractures of the carpal bones excluding the scaphoid. J Am Soc Surg Hand. 2002;2(3):129–40.

Pablo Rodríguez Sánchez-Laulhé

Physiotherapist with a Master’s degree in New Trends in Health Sciences and PhD student at the University of Seville. Health Researcher in Hand Therapy and Digital Health.