Wrist pain often proves to be a challenging presenting complaint. Determining the cause of ulnar-sided wrist pain is difficult, largely because of the complexity of the anatomic and biomechanical properties of the ulnar wrist.[1, 2]
The objectives of this article are to provide an overview of the most common problems that are encountered in the diagnosis of ulnar-sided wrist pain and to review the anatomy, diagnostic modalities, clinical presentation, and various treatments available.
Great advances have occurred in imaging techniques; however, although these imaging techniques are often invaluable, they can be expensive and unnecessary.
The majority of the diagnoses involving ulnar wrist pain may be established with a detailed history-taking, thorough physical examination, and standard radiography. When a diagnosis cannot be established with the standard methods, more advanced diagnostic modalities should be considered.
For patient education resources, see Wrist Injury.
NextBecause the structures of the wrist are highly interactive in producing normal and abnormal wrist mechanics, a brief review of the anatomy and kinetics of the entire carpus is included here. Refer to standard anatomy textbooks for further details.[1]
The wrist provides an anatomic link between the forearm and the hand. The wrist consists of the distal radius, the ulna, the carpal bones, and the bases of the metacarpals. The mobility of the wrist is determined by the shapes of the bones involved and by the attachments and lengths of the various ligaments.
The distal articular surface of the radius has an average radial inclination or slope of 22°, and it tilts palmarly by an average of 11°. The distal radius has a biconcave articular surface with two articular facets that are separated by an anterior and a posterior ridge. The lateral scaphoid facet is triangular, whereas the medial lunate facet is quadrilateral. The ulnar aspect of the radius has a concavity: the sigmoid notch, which articulates with the convex semicircular head of the distal ulna.
The distal radioulnar joint (DRUJ) is the articulation of the distal radius and ulnar head.[3] When the DRUJ is considered, it is important to note that the radius prosupinates upon the ulna. In both pronation and supination, the radius shortens (pronation) and lengthens (supination) in relation to the ulna. In the neutral position, the lengths of the radius and ulna should not differ by more than 1 mm.
The distal ulna does not articulate with the carpus. The triangular fibrocartilage complex (TFCC) serves as a cushion for the ulnar carpus and as a major stabilizer of the DRUJ.[4, 5, 6] Palmer and Werner coined the term TFCC to describe the ligamentous and cartilaginous structure that suspends the distal radius and ulnar carpus from the distal ulna.[7] The components of the TFCC include the central portion of the triangular fibrocartilage (articular disk), the dorsal radioulnar ligament, the volar radioulnar ligament, the meniscus homologue (ulnocarpal meniscus), the ulnar collateral ligament, the subsheath of the ECU, and the ulnolunate and ulnotriquetral ligaments.
The triangular fibrocartilage and the dorsal and volar ligaments arise from the ulnar aspect of the lunate facet of the radius. The triangular fibrocartilage continues ulnarly, inserting about the fovea at the base of the ulnar styloid. The fovea is a groove that separates the styloid from the ulnar head (see Clinical Presentation for a brief discussion of the ulnar fovea sign).
From the ulnar styloid, the triangular fibrocartilage extends distally, receiving contributions from the ulnar collateral ligament, which thickens (the meniscus homologue), inserting onto the lunate, the triquetrum, and the fifth metacarpal. The ulnar collateral ligament is a poorly developed thickening of the joint capsule that arises from the base of the ulnar styloid. The ulnolunate and ulnotriquetral ligaments arise from the volar radioulnar ligament and ulnar styloid, extend to the lunate and triquetrum, and then extend to volar aspects of the capitate and hamate. The tip of the ulnar styloid distal to the fovea is covered by hyaline cartilage where it lies within the prestyloid recess.
The sixth dorsal compartment containing the extensor carpi ulnaris (ECU) is a subsheath that is separate from the extensor retinaculum. From the dorsal base of the ulnar styloid, fibers from the subsheath blend and strengthen the dorsal aspect of the triangular cartilage and ligaments. These fibers extend to the fifth metacarpal distally. The actual extensor retinaculum courses over the subsheath; continues volarly without attachment to the ulna; and inserts onto the pisiform, triquetrum, fifth metacarpal, and volar ulnar soft-tissue structures.
At the volar wrist, the ulnar nerve lies lateral to the flexor carpi ulnaris (FCU) and is accompanied by the ulnar artery to its lateral side. Both the ulnar artery and nerve pass through the Guyon canal. The dorsal surface of the Guyon canal is composed of the pisohamate ligament. Forearm fascia and expansions from the FCU tendon (volar carpal ligament) form the volar surface. The canal is bordered by the pisiform medially and the hook of the hamate laterally.
The stability of the carpus is not solely a result of the interlocking shapes of the carpal bones, which are held together by interosseous (intrinsic) ligaments, as well as volar, dorsal, radial, and ulnar extrinsic ligaments. Intrinsic ligaments originate and insert on the carpal bones and can be collagenous (usually found at the dorsal and volar margin of the bone) or cartilaginous (usually along the articular surface). Extrinsic ligaments cross between the carpal bones and the radius or the metacarpals. The extrinsic ligaments maintain gross alignment; the intrinsic collagenous are intermediate in maintaining alignment, and the intrinsic cartilaginous provide fine tuning.
Additional ligaments of the wrist include components of the TFCC and the transverse carpal ligament. Although the amount of stability the flexor retinaculum provides the carpus is unknown, it is believed to contribute to the maintenance of the carpal arch.
The eight bones of the carpus serve as a link between the distal radius and ulna and the metacarpals of the hand. The carpal bones have typically been described as composing two rows, as follows:
Radial deviation of the hand and distal carpus is associated with palmar flexion of the entire proximal row, and ulnar deviation of the hand and distal row is associated with proximal row extension. This reciprocal motion is caused by the resulting joint reactive forces around the proximal row when the wrist is deviated radially and ulnarly. Radial deviation compresses the scaphotrapeziotrapezoid (STT) joint, forcing the scaphoid into flexion. With intact interosseous ligaments, the entire proximal row follows the scaphoid into flexion.
Ulnar deviation guides the triquetrum into its extended position against the hamate. With intact ligaments, the entire proximal row now follows the triquetrum into extension. In neutral deviation, these opposing forces are dissipated if the wrist is relaxed, and they are neutralized by intact bone and ligamentous supports if the wrist is stressed, as by a clenched fist. Consideration of this transverse ring model of carpal kinematics enables a clearer understanding of the pathomechanics of various carpal instabilities.
A thorough history often suggests or reveals the diagnosis of wrist pain. A careful history includes the timing of the injury—whether the wrist pain was caused by an acute injury or brought on by repetitive motions of the wrist. Information should be gathered regarding the location, duration, and radiation of pain. Any associated swelling, burning, or tingling should be documented.
Questioning the patient regarding specific sounds or sensations about the wrist is beneficial. Patients often describe grinding, snaps, clicks, or clunks, each of which is unique in sound quality and pathology. A click usually represents a medium-pitched sound that is caused by two bones rubbing together, as in triquetral instability. A snap is often high pitched and is associated with a subluxing tendon. Clunks are low-pitched sounds and may be the only presenting symptom of joint subluxation such as midcarpal instability. Grinding or crepitus is high pitched, usually representing synovitis. Eliciting this information may help the examiner narrow the differential diagnosis considerably (see Differential Diagnosis).
Physical examination should always begin with inspection, followed by determination of the range of motion and palpation. Often, physicians delay palpation or movement of the wrist until the end of the examination. In that way, other disorders can be excluded systematically while the patient is still fully cooperative. Finally, special provocative tests (eg, triquetrolunate ballottement, ulnar ballottement, midcarpal shifting) can be performed to confirm the suspected pathology (see Provocative Maneuvers).
Upon inspection, note any swelling, erythema, ecchymosis, abrasions, scars, nodules, or masses. Any deformity of the soft tissues or bony landmarks should be recorded.
To assess range of motion, test the wrist for active and passive motion in extension, flexion, and radial and ulnar deviation. At times, evaluating the range of motion of the hand, elbow, shoulder, and neck may be necessary. All of the measurements should be compared with the opposite extremity. Note the presence of pain or mechanical sounds with any particular motion.
An examination should become so routine that no one part is skipped over. Begin the examination at the proximal aspect of the dorsum of the wrist and advance distally. The volar aspect of the wrist is then evaluated with palpation from proximal to distal. The authors arbitrarily divide the wrist into dorsal radial, dorsal central, dorsal ulnar, volar ulnar, volar central, and volar radial sections. For the purposes of this discussion, the authors limit the discussion of the examination to the dorsal ulnar and volar ulnar zones.
Dorsal ulnar zone
The dorsal ulnar zone consists of the following:
Physical examination of the DRUJ should begin with examination of the contralateral wrist to note any ulnar variance or inherent joint instability of the individual. Evaluation of the DRUJ begins with palpation over the distal radius and lunate articulation that proceeds ulnarly to the sigmoid notch and distal ulna. Pain that occurs with forearm pronation and supination may suggest DRUJ disease. The examiner must be careful to rotate the forearm at the wrist, not at the hand. Squeezing the ulna and radius together causes pain, crepitation, or a snap in a patient with DRUJ disease. The examination should be performed in various stages of pronation and supination to detect ulnar-head chondromalacia or a small cartilaginous flap.
The TFCC is palpated just distal to the ulnar head. Any tenderness may indicate TFCC tears or chondromalacia from an acute injury or ulnar carpal abutment. Each of these disorders may be associated with clicking. Acute tears result in tenderness over the radial attachment (Palmer type ID injury) or avulsions off of the ulnar styloid (Palmer type IB injury).
The TFCC load test may reveal TFCC tears, though the pain may arise from ulnar abutment or chondromalacia of the hamate. To perform this test, apply axial force along the patient's ulnarly deviated wrist. With TFCC tears, forearm pronation and supination are usually pain free (unless passive rotation is initiated at the wrist or hand level). Dorsal subluxation or dislocation of the ulna results in decreased supination and a prominent dorsal ulnar head in pronation. Volar subluxation or dislocation results in decreased pronation and a dimpling of the dorsal skin over the ulnar head in supination.
There are also data to suggest that the so-called ulnar fovea sign may be a clinically useful test for defining ulnar-sided wrist pain in cases of foveal disruption of the distal radioulnar ligaments and ulnotriquetral ligament injuries.[8] In a retrospective study of 272 patients who had undergone wrist arthroscopy, 90 cases were of foveal disruptions and 68 were of ulnotriquetral ligament injuries. Of these patients, the ulnar fovea sign was positive in 156. The sensitivity of the sign was 95.2%, and the specificity was 86.5%.[8]
Testing for the ulnar fovea sign is performed by pressing the examiner's thumb distally into the interval between the ulnar styloid process and the flexor carpi ulnaris (FCU) tendon, between the volar surface of the ulnar head and the pisiform.[8] The sign is positive when the patient's pain is reproduced.
The ECU can be palpated in its groove adjacent to the ulnar styloid. It becomes prominent when the wrist is supinated and ulnarly deviated. Recurrent painful subluxation can be detected by a palpable snap when the forearm is actively supinated with the wrist flexed and ulnarly deviated. When stenosing tenosynovitis is present, the tendon is tender to palpation and swollen. Occasionally, crepitus may be noted within the swollen ECU subsheath. The patient's symptoms are reproduced with resistance to dorsiflexion and ulnar deviation.
The lunate is located 1 cm distal and ulnar to the Lister tubercle. Flexion of the wrist causes the lunate to become prominent. Tenderness and/or swelling over the dorsum of the lunate should increase the index of suspicion for Kienböck disease, especially when decreased range of motion secondary to pain is present. The lunotriquetral joint is palpated for tenderness, indicating a possible sprain or dislocation. An associated wrist click is often present with lunotriquetral instability. Tenderness on the radial side of the lunate may be secondary to an occult ganglion or a small scapholunate interosseous ligament tear.
The triquetrum is located distal to the ulnar head prominence and TFCC. Flexion and radial deviation of the wrist assist with palpation of the triquetrum. With the wrist in radial deviation, the triquetrum can be palpated in the sulcus between the ulnar styloid and the hamate. The hamate is palpated proximal to the base of the fifth metacarpal.
The midcarpal joint line lies between the hamate and triquetrum on the ulnar side of the wrist. Observe for a painful clunk with radial and ulnar deviation, which is characteristic of midcarpal instability. Provocative tests for this disorder are described below (see Provocative Maneuvers).
To identify the fourth and fifth CMC joints, palpate the metacarpal shaft, proceeding proximally to the metacarpal base. The metacarpal base is slightly more prominent than the shaft. Identify the fourth and fifth CMC joints, noting any tenderness or crepitus. Stress loading the fourth and fifth metacarpals with dorsal to volar rocking can reproduce symptoms that are consistent with arthrosis. An additional test is to apply rotational stress to the carpus, which often elicits pain in individuals with arthrosis.
Volar ulnar zone
The volar ulnar zone consists of the following:
The FCU is palpated easily at the ulnar volar aspect of the wrist when the patient's digits are abducted and extended. Pain with resisted flexion and ulnar deviation of the wrist as well as increased warmth and swelling are likely to be present in tendinitis.
The ulnar styloid can be palpated along the volar ulnar aspect of the ulnar head with the wrist radially deviated. Tenderness, swelling, or ecchymosis may be present on examination of a styloid fracture. Peripheral TFCC tears of the ulna (Palmer type IB injury) cause tenderness over the ulnar styloid. TFCC tears of the ulnolunate and ulnotriquetral ligaments (Palmer type IC injury) result in tenderness over the volar aspect of the distal ulna.
The pisiform, ensheathed by the FCU, is seated over the anterior aspect of the triquetrum. To locate the pisiform, which is at the level of the wrist crease, palpate along the FCU distally. Pain and swelling over the pisiform and hypothenar region may indicate a subluxation, arthritis, or a fracture. With the patient's wrist relaxed, the pisiform is often mobile, and it can be palpated with ballottement over the triquetrum. In the presence of pisotriquetral arthrosis, this direct loading can cause pain and crepitation.
The hook of the hamate is located by identifying the pisiform and then palpating along a line from the pisiform to the head of the second metacarpal. The hook lies approximately 2 cm from the pisiform. Although firm pressure over a fractured hook generally causes discomfort, mild to moderate pressure may cause little pain. In hook fractures, abduction and adduction of the small finger against resistance is often uncomfortable.
The Guyon canal is located between the pisiform and the hook of hamate. Both the ulnar nerve and ulnar artery course through the canal. Gentle palpation over the canal with a rolling motion often reveals the ulnar nerve. Always palpate for a pulsatile mass in the region. An aneurysm, ganglion cyst, or other soft-tissue mass can compress the ulnar nerve, causing sensory deficits, motor deficits, or both, depending on the location of the mass. Acute thrombosis of the ulnar artery in the Guyon canal can be exquisitely tender and causes peripheral neurovascular signs and symptoms.
Once inspection, motion testing, and palpation of the soft-tissue and bony structures have been completed, several provocative maneuvers may be useful to further differentiate the suspected pathology.
Stress loading tests are used to assess the stability of the distal radioulnar joint (DRUJ)/triangular fibrocartilage complex (TFCC), as well as to distinguish DRUJ/TFCC pathology from lunotriquetral or triquetrohamate joint disease. The piano-key test involves depressing the distal ulna from dorsal to volar with the hand pronated. A positive result is characterized by painful laxity in the affected wrist compared with the contralateral wrist. The results are usually positive in cases of DRUJ synovitis.
The ulnar compression test may reveal degeneration or inflammation of the DRUJ. To perform this test, compress the ulnar head against the sigmoid notch. A positive result is exacerbation of pain, which suggests arthritis or instability. In addition, with ulnar compression, dorsal or volar subluxation may be noted.
See Clinical Presentation for a brief discussion of the ulnar fovea sign.
Reagan et al described the lunotriquetral ballottement test, which can be used to elicit the laxity that is associated with pain and crepitus in the presence of instability.[9] To perform this test, the lunate is stabilized with the thumb and index fingers of one hand, while the other hand attempts to displace the pisotriquetral unit volarly, then dorsally.
In the shuck test, the lunate is stabilized with the same technique that is used in the ballottement test. The wrist is then taken through both active and passive radial and ulnar deviation. The test results are positive if pain or clicking at the lunotriquetral joint is present.
The ulnar snuffbox test is performed by applying radial pressure in the sulcus between the extensor carpi radialis and the flexor carpi ulnaris (FCU) distal to the ulnar head. The results are considered positive if the patient's pain is reproduced, suggesting triquetral chondromalacia or lunotriquetral injury. In addition, the examiner may wish to inject approximately 0.5 mL of lidocaine into the lunotriquetral joint to differentiate intra-articular from extra-articular pathology.
To test for midcarpal instability on the right wrist, the examiner stabilizes the patient's forearm, with the left hand in a pronated position.[10] With the patient's wrist in 15° of ulnar deviation, the examiner's right thumb exerts volarward pressure at the level of the distal capitate. The wrist is then simultaneously axially loaded at the metacarpals and ulnarly deviated. The result is positive if a painful clunk occurs that reproduces the patient's symptoms.
The pisotriquetral grind test is also effective in reproducing arthritic pain. To perform the pisotriquetral grind test, hold the pisiform between the thumb and index finger; then move the pisiform ulnar to radial, with the wrist in various positions of flexion and radioulnar deviation, to reproduce the patient's pain or crepitus.
The conditions below are listed in the order in which they would be found during examination. For further discussion of the more common conditions, see Common Causes of Ulnar Wrist Pain.
Conditions that may be noted in the dorsal zone include the following:
Conditions that may be noted in the volar zone include the following:
Most diagnoses that involve ulnar-sided wrist pain can be made on the basis of a thorough history, a complete physical examination, and routine radiography.[1, 2, 31] However, additional studies are occasionally indicated.
Routine radiographs should include posteroanterior (PA) and lateral views of the wrist.[17] The images should be obtained with the patient seated, the forearm in a neutral position, the elbow flexed to 90°, and the shoulder abducted to 90°. Other views are obtained on the basis of the clinical suspicion. The carpal tunnel view is useful to visualize the hook of hamate and the pisotriquetral pathology. An oblique view in 30° of pronation allows evaluation of the dorsal ulnar wrist. The reverse oblique view (30° of supination) allows evaluation of the volar ulnar aspect of the wrist, with a profile of the pisotriquetral joint.
Radionuclide imaging can be an excellent screening tool for the assessment of skeletal and joint disorders that are not evident on routine physical examination and radiography. This study consists of injecting methylene diphosphate that is labeled with technetium-99m (99mTc), followed by three imaging phases: vascular (angiogram), equilibrium (soft-tissue blood pool), and delayed (bone).
About 95% of bone scan findings are abnormal in the presence of occult fractures and complete intrinsic ligament tears. Increased radionuclide uptake can also be helpful in localizing intraosseous lesions such as avascular necrosis (AVN), osteoid osteoma, and metastasis (rare), among others. In some cases, negative bone scan findings may reinforce a suspicion of malingering.
Ultrasonography can be used for the evaluation of soft-tissue anatomy.[32, 33] This imaging modality has been particularly useful in evaluating ganglion cysts, tendons, and tendon sheaths. In current practice, magnetic resonance imaging (MRI) has largely replaced ultrasonography in the evaluation of these conditions.[34]
This type of imaging examination is useful for evaluating dynamic ligament instabilities (patients with a history of wrist clicking or popping whose findings are normal on plain images). The wrist should be examined through an entire range of active and passive motion, as well as with provocative maneuvers, in an attempt to reproduce the patient's symptoms. Sagittal and coronal studies should be performed. Recording the fluoroscopic examination allows detailed study without excessive radiation exposure. The diagnosis of midcarpal instability can be confirmed on videofluoroscopy.
When imaging examination results suggest a triangular fibrocartilage complex (TFCC) defect or interosseous ligament instability, arthrography may be used to confirm the diagnosis.[35, 36] Contrast material may be injected into one of the three noncommunicating spaces of the carpus: the distal radioulnar joint (DRUJ), the radiocarpal joint, and the midcarpal joint. The decision to obtain a single-injection arthrogram versus a triple-injection arthrogram must be based on specific clinical findings.
At least one third of cadaver dissections have abnormal communications of the wrist joint. Mikic reported that the incidence of degenerative perforations that allow these abnormal communications increases with age.[37] Many of these perforations are asymptomatic.
Magnetic resonance arthrography enhances arthrography and would be the examination of choice for the detection of interosseous and extrinsic ligament tears. However, the value of arthrography has come into question because most findings can be viewed directly with arthroscopy or MRI. In some instances, contrast-enhanced MRI can be used to determine whether a fluid-filled sac communicates with the wrist joint.
Computed tomography (CT) can reveal detailed osseous and articular anatomy.[36] Sections consist of 2- to 3-mm serial sections, which are taken in two positions at 90° angles from each other. When greater detail is required, 1-mm sections may be used. Obtaining comparative scans of the opposite extremity is sometimes helpful.
CT may be used to detect fractures, including fractures of the hook of hamate that are not evident on radiographs, to assess bone healing, and to identify occult tumors. Axial CT provides an excellent means for evaluating DRUJ deformities. CT depicts much more bony detail than conventional radiography does, particularly when positioning the extremity is difficult because of patient pain or cast immobilization.[38]
The accuracy of MRI is highly dependent on both the interpretative and the technical abilities of the radiologist and the surgeon.[39, 40] The choice of the correct imaging sequences and technique depends on good communication between these clinicians. When properly performed, MRI provides valuable information in the detection of soft-tissue and osseous lesions, including interosseous and extrinsic ligament tears, TFCC defects, tumors, avascular necrosis, and occult fractures.[41, 38, 42, 34]
Arthroscopy requires specialized training and an understanding of the detailed anatomy of the wrist.[35] Wrist arthroscopy can be used to confirm a diagnosis that is suggested by findings from other diagnostic modalities, or for the primary diagnosis of ulnar wrist pain of unknown etiology. Many consider this modality to be the criterion standard for the diagnosis of intra-articular pathology.[43]
In addition to diagnostic indications, arthroscopy has therapeutic applications. Arthroscopy is used in the treatment of ulnar abutment, TFCC defects,[44] interosseous ligament tears, chondral defects, loose bodies, synovitis, and degenerative arthritis. The standard indications for wrist arthroscopy are continuing to evolve.
See Differential Diagnosis for a list of conditions that cause ulnar wrist pain. Common conditions from this list are discussed below.
The extensor carpi ulnaris (ECU) courses through the sixth dorsal compartment, where it is held tightly to the ulnar groove by a subsheath, which is separate from the extensor retinaculum. When the ECU tendon subluxes, the subsheath is torn, whereas the retinaculum usually remains intact.[12] The mechanism that causes ECU subluxation is often forced supination, palmar flexion, and ulnar deviation. The ECU tendon is relocated with pronation.
The patient has pain over the dorsal wrist and clicking or snapping with pronation and supination. On evaluation, the subluxation can be reproduced with active forearm supination and ulnar deviation. Tenderness and swelling are often present over the ECU tendon at the ulnar head. Routine radiographic findings are negative. Further studies are often unnecessary. Magnetic resonance imaging (MRI) can show inflammation about the sheath, as well as malpositioning of the tendon.
In acute subluxation, immobilization for 6 weeks in a long-arm cast with the forearm pronated and the wrist in slight radial deviation and dorsiflexion should be attempted. With chronic and symptomatic subluxation, surgical reconstruction of the subsheath is beneficial.
The sixth dorsal compartment is the second most common location of stenosing tenosynovitis in the upper extremity. Although relatively uncommon, stenosing tenosynovitis must be included in the differential diagnosis for ulnar wrist pain.[11]
Patients present with generalized pain of the wrist, with dorsal swelling over the ulna. Many patients are athletes whose sport requires repetitive wrist motion. Clinically, the patient's symptoms may be exacerbated with resistance to dorsiflexion and ulnar deviation. Crepitus is occasionally palpable over the ECU sheath. An injection of lidocaine and cortisone into the sheath can be both diagnostic and therapeutic. As with subluxation, MRI can be used to confirm the diagnosis.
Conservative treatment includes activity modification, ice, splinting, steroid injections, and nonsteroidal anti-inflammatory drugs (NSAIDs). Surgical release is often necessary with progressive fibrosis of the sixth compartment.
With partial rupture or calcific tendinitis, the ECU may be tender, red, and tense. A radiograph is diagnostic for calcific tendinitis.
Distal radioulnar joint (DRUJ) arthritis may arise from various sources, such as repetitive injury, previous trauma with deformity, or systemic disease (eg, RA). The patient may complain of decreased grip strength, pain, clicking, or decreased range of motion. Physical examination reveals pain with forearm pronation and supination. Squeezing the ulna and radius together often produces pain, crepitation, or snapping.
Plain radiographs may reveal osteophytes, joint-space narrowing, deformity, or subchondral cysts. When radiographic findings are negative, computed tomography (CT) of the DRUJ may reveal degenerative changes of the ulnar head.
Conservative treatment includes rest, use of NSAIDs, immobilization, and steroid injections. If conservative treatment fails, surgical options include hemiarthroplasty, ulnar head excision (Darrach), or osteotomy/fusion (Sauve-Kapandji) procedures.
Lesions of the triangular fibrocartilage complex (TFCC) can be divided into two categories: traumatic and degenerative.[18, 45, 46, 47] Palmer developed a classification system for TFCC abnormalities based on anatomic and biomechanic studies, as well as clinical observation.[4, 7, 47]
Traumatic lesions may result from an acute hyperrotation injury to the forearm; a distraction injury to the wrist; or an axial loading injury, which may occur with a fall on an outstretched extremity. These injuries can occur in isolation or may be associated with ulnar styloid fractures, intra-articular distal radius fractures, radial head fractures, both bone fractures, and midshaft radius fractures.
Degenerative lesions are the result of chronic injuries that involve loading on the ulnar wrist; however, many of these lesions are asymptomatic. The lesions are divided into subcategories that progress from early TFCC wear to stage IV ulnar impaction syndrome. There is an association between patients with positive ulnar variance and degenerative defects of the TFCC. In addition, several studies have demonstrated an age correlation with lesions in the TFCC.
Patients complain of ulnar pain, clicking, or snapping with wrist motion. On examination, swelling and localized tenderness are often present over the dorsal TFCC. The TFCC load test results are likely positive. Loss of forearm pronation and supination may occur as a result of pain, and audible clicks may be noted with forearm rotation.
Radiographs are assessed for ulnar variance and to exclude other possible osseous or ligamentous pathology. Arthrographic findings are diagnostic for TFCC tears; however, not all tears are symptomatic, and further investigation may be necessary. Additional diagnostic modalities could include arthroscopy and MRI. Differential local anesthetic injections can also aid in the diagnosis.
Traumatic lesions in the absence of instability are treated conservatively. Treatment includes a long-arm cast worn for 6 weeks, use of NSAIDs, and perhaps steroid injections. Lesions associated with instability or those that fail to respond to conservative therapy are treated surgically. Arthroscopy and debridement of flap tears are effective in stable injuries if no ulnar impaction is present. If impaction or instability is present, ulnar shortening is recommended.[18]
Degenerative lesions are usually the result of impaction and may be treated conservatively as well. Injuries that fail to respond to conservative treatment are considered for TFCC debridement and ulnar shortening.
Ulnar styloid fractures occur as isolated injuries or in association with distal radius and other wrist fractures.[20] Symptomatic nonunion is rare. Such nonunion of fractures has been classified into the following two types, depending on the location and stability of the DRUJ:
Patients with these fractures present with a limited range of motion, grip weakness, and ulnar wrist pain that is exacerbated by ulnar deviation and twisting the wrist. Clinically, tenderness at the ulnar snuffbox, and possibly swelling and ecchymosis, are present, depending on the timing of the patient's presentation. The DRUJ is assessed for stability by using the piano-key test. Routine radiographs may not reveal a fracture; CT scans may be beneficial.
Because the TFCC attaches to the base of the ulnar styloid, fractures at the tip that remain and continue to be painful after failed conservative treatment may be treated with excision. Nondisplaced or minimally displaced acute fractures at the base of the styloid should be treated with cast immobilization with the wrist in the neutral position and slightly ulnarly deviated for 6 weeks.
Displaced fractures that are associated with distal radius fractures often reduce with the reduction of the distal radius. Large styloid fractures at the base that are associated with DRUJ instability and that remain displaced by more than 2-3 mm require open reduction and internal fixation (ORIF) with either a small fragmentation screw or tension banding and cast immobilization for at least 6 weeks.
As previously noted, swelling and tenderness localized to the TFCC and lunotriquetral joint suggests ulnar impaction syndrome.[17, 18, 21, 22, 24] Ulnar impaction can progress from TFCC wear to frank tears, triquetral chondromalacia, and lunotriquetral instability. Radiographs show an ulnar positive variant and, often, cysts in the triquetrum and ulnar one half of the proximal lunate. MRI can be helpful in the diagnosis by revealing signal changes and edema in the ulnar head, triquetrum, and lunate. The treatment is ulnar shortening[48, 49] or a wafer procedure.[50]
In the absence of acute trauma, chronic wrist pain that is localized about the lunate should suggest Kienböck disease.[51, 52, 53, 54, 55] Several theories address the etiology of Kienböck disease. Most orthopedists believe that it is acute trauma or repetitive minor trauma that causes interruption of the blood supply to the at-risk lunate. Risk factors include ulnar variance, lunate vascularity, lunate geometry, trauma, and congenital and developmental disorders.
Lichtman et al modified Stahl's original classification that consisted of four stages of Kienböck disease.[1, 53] In this approach, the disease is staged as follows:
The typical patient with Kienböck disease is aged 20-35 years and has chronic wrist pain, often without a history of acute trauma. Clinically, tenderness is present over the dorsum of the lunate, with occasional associated swelling. Often, range of motion and grip strength are decreased compared with the contralateral hand. Early in the disease, the examination findings may be somewhat benign, more consistent with a wrist sprain. However, as the disease continues, synovitis progresses, and in the late stages, arthritis is the predominant clinical finding.
Numerous nonoperative and operative options can be used to treat Kienböck disease. The classification scheme proposed by Lichtman provides treatment recommendations based on radiologic staging.[53] Two major factors determine treatment: the presence or absence of ulnar variance and the stage of the disease. Staging directs treatment toward either salvaging the lunate or correcting the altered carpal structure and kinematics. The treatment includes immobilization, revascularization, radial wedge osteotomy, radial shortening, scaphotrapeziotrapezoid or scaphocapitate fusion, and salvage procedures (proximal row carpectomy, wrist arthrodesis).
The triquetrum is the most commonly fractured carpal bone. Isolated fractures are rare; most triquetral fractures are associated with other carpal injuries, such as perilunate transtriquetral dislocation.[56] Two types of triquetral fractures occur, dorsal cortical fractures and fractures through the triquetral body. Some authors have suggested that dorsal cortical fractures can be produced from avulsion fractures or impaction of the ulnar styloid when the wrist is forcibly dorsiflexed and ulnarly deviated. Isolated fractures of the body are usually the result of a direct blow to the ulnar wrist.
On examination of an acute fracture, tenderness, swelling, and (occasionally) ecchymosis are found. An associated loss of extension and ulnar deviation of the wrist is often present. In addition to routine radiographs, an oblique view in 30° of pronation often reveals a fracture. When the clinical suspicion of a fracture remains high in the absence of an obvious fracture on plain radiography, CT should be considered.
Dorsal cortical fractures may be treated with cast immobilization for 6 weeks. If un-united cortical fragments remain symptomatic, excision may be necessary. Triquetral body fractures are usually nondisplaced and heal well with cast immobilization for 6 weeks. When the triquetral body is displaced, ORIF may be required. To the authors' knowledge, no reports of avascular necrosis (AVN) of the triquetrum have been published.
Lunotriquetral ligament tears may occur as a result of hyperextension and radial deviation of the wrist or as part of ulnar impaction syndrome.[17, 24, 57] Isolated lunotriquetral tears must be differentiated from ulnar impaction syndrome; the treatment for ulnar impaction syndrome focuses on ulnar shortening. Studies have shown that isolated tears of the lunotriquetral interosseous ligament do not result in volar intercalated segment instability. However, a volar flexed intercalated segment instability (VISI) deformity occurs when the interosseous ligament and the dorsal radiolunotriquetral ligament are disrupted.
Most patients present with a history of trauma. Clinically, tenderness is present about the lunotriquetral joint, and range of motion and grip strength are decreased. Patients are often able to reproduce a painful wrist clunk with radioulnar deviation. Provocative maneuvers such as the ballottement test, shuck test, and ulnar snuffbox test may help elucidate the injury.
In stable injuries, routine radiographic findings are normal; stress radiographs may be necessary to detect abnormality in patients with a dynamic instability.
In unstable tears, a VISI deformity is noted, along with a stepoff at the lunotriquetral joint. Wrist arthrography can depict the lunotriquetral tear. Sequential injections of the midcarpal and radiocarpal joints decrease the false-negative rate because some tears may leak in only one direction. If the arthrogram demonstrates a significant leak through the lunotriquetral interval, arthroscopy should be performed to evaluate the extent of the disruption.
Compared with arthrography, wrist arthroscopy is more helpful in determining the location and extent of lunotriquetral ligament disruption. Although MRI is reliable in depicting AVN of the lunate and scaphoid, only in expert hands is it valuable in detecting lunotriquetral tears.
The initial treatment for all acute lunotriquetral tears should include immobilization for 6-8 weeks. Patients with chronic tears or dissociation and those whose injuries do not respond to conservative treatment are candidates for surgery. If the tear is then stable, arthroscopic debridement is recommended. If the lunotriquetral ligament is unstable, reconstruction or lunotriquetral arthrodesis is the preferred treatment.
Various authors have called palmar midcarpal instability (PMCI)[17, 25, 26] by many names, including ulnar midcarpal instability, capitolunate instability pattern, ulnocarpal instability, and midcarpal instability. The most likely etiology in patients who present with a painful midcarpal clunk is dysfunction of the key ligaments that causes a loss of normal joint reactive forces between the proximal and distal rows. These ligaments include the arcuate, triquetrohamate, and capitolunate ligaments volarly and/or the radiotriquetral ligament dorsally.
In a normal wrist with ulnar deviation, the distal row translates from volar to dorsal as the proximal row rotates from flexion to extension. With laxity, attenuation, or traumatic disruption of these ligaments, the coupled rotation of the carpus is no longer present. Instead, the proximal row stays flexed, and the distal row remains excessively volarly translated until the extreme of ulnar deviation is reached, causing the proximal row to abruptly snap back into extension and the distal row to reduce (translate dorsally). The diagnosis frequently is based on the history and radiographic studies, in addition to the results of physical examination and midcarpal shift testing.
Patients present with painful clunking that occurs with ulnar deviation and pronation of the wrist. A history of trauma may or may not be present. Patients may describe a long period of asymptomatic clunking that has now become painful. The other extremity should be assessed for similar symptoms because the instability is frequently bilateral. Clinical findings may include a volar sag at the ulnar wrist with a prominent-appearing ulnar head when the wrist is at neutral position. If a localized synovitis is present, tenderness may be present over the ulnar carpus, particularly at the triquetrohamate joint. If the patient is unable to reproduce the clunk actively, it may be reproduced passively with the midcarpal shift test.
Because PMCI is a dynamic disorder, findings from plain radiography are often unremarkable . Videofluoroscopy is the imaging study of choice. Both PA and lateral projections should be taken as the patient moves the wrist from radial to ulnar deviation in an attempt to reproduce the clunk. In addition, arthroscopy can enable the surgeon to definitively exclude any other lesion, particularly proximal low ligament tears. The role of MRI in the evaluation of PMCI has not yet been defined.
Nonoperative treatment may include activity modification, use of NSAIDs, steroid injections, and splinting. Surgical options include limited midcarpal arthrodesis, distal advancement of the volar ulnar arm of the arcuate ligament, dorsal radiocarpal capsulodesis, and suturing the palmar radioscaphocapitate ligament to the radiolunotriquetral ligament to close the space of Poirier.
Fractures of the body of the hamate are much more uncommon than fractures of the hook of the hamate.[27, 28, 30, 32] Fractures of the body are often associated with fourth and fifth carpometacarpal (CMC) fracture-dislocations. Fractures of the body may occur as a result of an axial force that is transmitted through the metacarpals or a direct blow to the ulnar aspect of the wrist. Fractures of the hook of the hamate most often occur when one swings a baseball bat, golf club, or racquet.[58] The fracture may result from repetitive stress or a direct blow when a club or racquet strikes the ground.
The presentation of a body or hook fracture is similar. A high index of suspicion is required or a fracture might be easily overlooked. Firm pressure over the hook often causes tenderness. However, direct pressure over the dorsal body of the hamate can reproduce pain, particularly when the fracture is at the base of the hook. Grip weakness and pain with resistance to small-finger flexion are often present. The failure to diagnose and treat these fractures early may result in flexor tendon rupture and ulnar nerve palsy. In addition to routine radiographs, a carpal tunnel view should be obtained. CT should be considered when clinical findings indicate a fracture that is not present on routine radiographs.
Fractures of the hook and body are usually nondisplaced, and they can be treated with cast immobilization. Intra-articular fractures with a displacement greater than 1 mm are best treated with open reduction and internal fixation. Displaced fractures that involve the distal aspect of the hook often result in nonunion if they are not treated with open reduction and internal fixation.
Ulnar nerve entrapment as a result of compression in the Guyon canal usually presents as a motor lesion due to isolated involvement of the deep motor branch as it courses around the hook of the hamate.
Patients often have a positive Tinel sign over the Guyon canal with paresthesia in the small and ring fingers. However, sensation is not decreased over the dorsal or ulnar aspect of the hand.
The exact cause of ulnar nerve compression at the wrist can usually be determined by means of careful history taking, physical examination, and imaging studies. MRI is particularly helpful in identifying a space-occupying lesion, such as a ganglion cyst. A good history can help establish the diagnosis of ulnar artery thrombosis or injury due to activities such as walking with crutches, kayaking, and playing handball.[58]
Activity-related neuropathy often is eliminated when the offending activity is stopped. However, with unexplained deep motor branch paralysis, exploration of the Guyon canal is appropriate.
Thrombosis of the ulnar artery in the Guyon canal can occur as a consequence of direct trauma. Patients with ulnar artery thrombosis at the wrist may present with pain at night or with repetitive activity and cold intolerance. Exquisite tenderness is present at the site of pathology. Eventually, patients may have dependent rubor or ulceration of the ring finger and the tips of the little fingers. Excitation of the sympathetic fibers of the ulnar proper digital nerves frequently is noted. The diagnosis can be confirmed with the Allen test.
In the Allen test, the patient's affected wrist is elevated, and the patient makes a fist for about 30 seconds. The examiner applies pressure over the radial and ulnar arteries; then the patient opens the fist. The hand should appear blanched. The examiner then releases the ulnar artery pressure. The test is positive when blood does not return to the hand or the time to return of blood flow is prolonged.
Arteriography is often helpful before the definitive treatment is decided. The standard treatment for ulnar artery thrombosis is ligation and resection of the thrombosed segment. Reconstruction of the artery with a vein graft is necessary only when backflow from the radial side of the arch is insufficient.
Although ulnar wrist pain can be a difficult challenge, a thorough understanding of the relevant anatomy, meticulous history-taking, careful physical examination, and standard radiography can help clinicians identify almost any source of symptoms. After standard examinations have been used, advanced imaging and arthroscopy can help in finalizing the diagnosis. Selection of appropriate treatment modalities easily follows the establishment of a correct diagnosis.
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