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When considering the ulnar wrist patient, one must thoroughly investigate the triangular fibrocartilage complex (TFCC); however, a more global look at the functional forearm joint complex is also required.
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General diagnostic categories of ulnar wrist pain include fracture, degenerative changes, instability, tendinitis, TFC–articular disk tears, and nerve compression.
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Several simple assessment techniques are available to identify sources of ulnar wrist pain, including the articular disk shear test, distal radioulnar joint (DRUJ) instability test, DRUJ grind and rotate test, pisotriquetral grind test, lunotriquetral (LT) ballottement test, carpal instability nondissociative (CIND) catch-up clunk test, extensor carpi ulnaris (ECU) instability test, and the gripping rotatory impaction test (GRIT).
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To most effectively treat patients with ulnar wrist pain, the clinician must understand what structures need protecting and what structures need moving, deliver stressors to these structures in a judicious manner, and be able to use various modes of treatment to accomplish these tasks.
Often, when the structures that make up the DRUJ are injured, specifically the TFCC, ulnar wrist pain results. In addition to this pain, traumatic injuries, inflammatory conditions, and degeneration of the DRUJ-TFCC can cause restricted forearm motion or, conversely, instability and diminished grip strength. This ulnar wrist pain and impairment can have many causes, thereby making it difficult to identify its etiology. When considering the ulnar wrist patient, one must thoroughly investigate the TFCC; however, a more global look at the functional forearm joint complex is also required. Abnormalities throughout the forearm (e.g., malunions of the radius or ulna, radial head fractures with interosseous membrane disruption, positive ulnar variance) can markedly affect the DRUJ and ultimately the TFCC. By broadening the focus of this chapter to include not only the TFCC but also other structures that are anatomically and functionally related, we intend to better prepare the clinician in the diagnosis and treatment process and also help therapists avoid potential pitfalls when managing patients with ulnar wrist pain and impairment.
The purposes of this chapter are (1) to identify what anatomic structures or pathomechanical problems can cause ulnar wrist pain, with a focus on and about the TFCC; (2) to use an algorithmic approach in the clinical assessment of the patient with ulnar wrist pain and impairment while learning some simple assessment techniques to help identify these lesions; and finally (3) to consider treatment and management principles in the conservative and postoperative care of these TFCC patients.
Ulnar Wrist Pain and Impairment: The TFCC and Distal Forearm
A review of ulnar wrist pain and the TFCC is not complete unless the structures about the distal forearm are considered. In the strict anatomic sense, the distal forearm joint is composed of the DRUJ. Functionally, however, the distal forearm joint is composed of the DRUJ, TFCC, ulnocarpal ligaments, and interosseous membrane (see Chapter 71 ). This section includes (1) an introduction to the anatomic structures in and about the TFCC that can contribute to ulnar wrist pain and impairment, and (2) a description of general clinical pathomechanical concepts that will help formulate specific assessment and treatment techniques (which are described in the sections that follow).
TFCC and DRUJ
The TFCC—a compilation of ligaments, meniscus homologue, a tendon sheath, and a fibrocartilaginous articular disk (also known as the triangular fibrocartilage proper ) ( Fig. 72-1 )—serves to stabilize the DRUJ and separate it from the carpus and distal radius. The anatomy of the DRUJ ( Fig. 72-2 ) promotes both rotational and sliding movements between the radius and ulna, resulting in forearm rotation. This movement is controlled in large part by the TFCC and other soft tissues that complement the distal forearm joint (see Chapter 71 ).
Forces transmitted through the wrist complex when axially loaded, as in gripping, affect the ulnar side of the wrist. The ulna, through its articulation with the ulnar carpus and the TFCC, absorbs 20% of these forces, whereas the radius, through its articulation with the radiocarpal joint, transmits approximately 80% of the force through the forearm. However, when the normal articular relationship between the distal radius and ulna is disrupted, as seen with malunited distal radius fractures and DRUJ incongruity, loads through the ulnar structures can exceed physiologic limits and TFCC lesions are common. Ulnar variance, the distance that the distal articular portion of the ulnar head extends below (negative) or above (positive) the articular surface of the radius, can also affect this force distribution markedly, with the latter increasing ulnar-sided forces and the former increasing radial-sided forces ( Fig. 72-3 ). Ulnar variance dynamically changes with forearm motion, with a shift toward a positive direction with forearm pronation and gripping and toward a negative direction with supination and an unfisted hand. When variance increases from neutral to 2.5 mm positive, ulnar-sided wrist forces increase 20%. Tomaino found that pronation and grip increase ulnar variance in a positive direction by 2.5 mm. The functionally common movement of forearm pronation while gripping (e.g., twisting a door handle, ironing, scrubbing, pouring a drink) can adversely affect ulnar-sided structures such as the TFCC, lunate, and LT ligament, whereas unloading of these structures occurs with supination.
TFCC Articular Disk Tears
The fibrocartilaginous articular disk, or triangular fibrocartilage (TFC), has four separate zones ( Fig. 72-4 ). Traumatic tears of the TFC–articular disk, which typically occur with forearm rotation and forces being transmitted through the ulnar side of the wrist (e.g., falling on the hand, having the forearm forcibly twisted while gripping), occur approximately 1 to 2 mm ulnar to the articular disk’s attachment to the radius. The central portion of the articular disk, where degenerative perforations occur, does not contribute to DRUJ stability, yet it is well suited for compressive loads associated with gripping. The central 80% to 85% of the articular disk is avascular, which often renders this region incapable of healing. However, the radial aspect of the articular disk does have a vascular plexus extending between the radius and the articular disk and is considered by many to be surgically repairable.
Ulnocarpal Abutment
Ulnocarpal abutment, also known as ulnocarpal impaction , loading , and impingement , is a degenerative syndrome associated primarily with a positive ulnar variance, thereby increasing the force transmission across the ulnocarpal articulation. A sequence of events characterizes this syndrome, with wearing of the articular disk of the TFCC, chondromalacia of the ulnar head and proximal ulnar aspect of the lunate, and disruption of the LT ligament. Often, trauma (i.e., malunited radial shortening or angulation after a distal radius fracture or DRUJ ligament injuries that occur with Galeazzi’s and Essex–Lopresti fractures) can contribute to ulnocarpal abutment. Other nontraumatic causes of ulnocarpal abutment include excision of the radial head, wrist arthrodesis, congenital abnormalities, and a naturally occurring ulnar-plus variance associated with overuse. This syndrome may also occur in wrists with an ulnar-neutral to -negative variance due to dynamic changes in variance with forearm pronation, grip, and ulnar deviation of the wrist.
Typically, patients with a stable but painful DRUJ secondary to an ulnocarpal abutment of the articular disk will have chronic or subacute pain localized to the dorsal aspect of the wrist over the DRUJ, or the pain will be located ulnarly directly over the TFCC region. Patients may also complain of an intermittent clicking sensation as well as activity-related swelling, and decreased strength and motion. Assessing the articular disk region of the TFCC with the forearm pronated, wrist ulnarly deviated, and hand fisted increases ulnar variance and often reproduces pain in patients with ulnocarpal abutment and TFCC articular disk lesions. Chondromalacia of the ulnar head and lunate must also be investigated in addition to the presence or absence of an LT ligament tear in these patients.
TFCC Radioulnar Ligament Tears
When considering treatment options, it is imperative to distinguish between TFCC lesions that are associated with instability from those that are not. Unlike the articular disk portion of the TFCC, the dorsal radioulnar ligament (DRUL) and palmar radioulnar ligament (PRUL) (see Fig. 72-1C ) of the TFCC serve a stabilizing function of the DRUJ and are well vascularized, thus improving their healing capabilities. It is generally agreed that portions of the PRUL and DRUL become taut at the end-ranges of forearm rotation. These longitudinally oriented ligaments, which originate from the radius and insert into the ulnar styloid, serve a stabilizing function (along with the ulnar head’s contact on the sigmoid notch) of the DRUJ. If excessive DRUJ volar or dorsal translation is detected in full pronation or supination, a tear of the DRUL or PRUL might be suspected.
Classification of TFCC Injuries
The classic work of Palmer has resulted in a categorical system of TFCC injuries that is commonly used and describes two broad types of tears: traumatic and degenerative. In the Palmer classification ( Box 72-1 ), the traumatic lesions are subdivided into four types. Type I is a central tear within the fibrocartilaginous substance of the articular disk. Type II is an avulsion tear from the base of the ulnar styloid, which is the soft tissue equivalent of the ulnar styloid avulsion fracture. Type III is a tear of the palmar third of the PRUL and usually involves the ulnocarpal ligaments. Type IV is a radial avulsion of the articular disk, with or without bone from the distal radius, and usually associated with distal radius fractures. The Mayo classification supplements Palmer’s original classification by also discriminating between traumatic and degenerative lesions; this classification is also location-based and serves as a surgical treatment algorithm ( Box 72-2 ).
Traumatic Tear (Types)
I Central
II Medial (± styloid fracture)
III Distal (ulnocarpal)
IV Lateral (radial attachment, distal radius fracture)
Degenerative Tear (Stages)
I TFCC wear
II TFCC wear and chondromalacia
III TFCC perforation and chondromalacia
IV TFCC perforation
+ chondromalacia
+ lunotriquetral ligament tear
V TFCC perforation
+ ulnocarpal arthritis
TFCC, Triangular fibrocartilage complex.
Traumatic Tear (Types)
I Radial rim (detachment)
II Central
III Ulnar (equivalent ulnar styloid fracture)
IV Palmar
Degenerative Tear (Types)
I Central (stellate) tear
II Central tear, ulnocarpal impingement
III Central tear, impingement, lunotriquetral ligament tear
IV Central tear, impingement, lunotriquetral arthritis (radioulnar arthritis?)
Treatment
Traumatic Tear
I, III, IV Surgical repair
II Excision
Degenerative Tear
I Excision
II Excision and ulna recession
III Excision, lunotriquetral reconstruction, ulna recession
IV Ulna excision (Darrach) versus ulna recession only
TFCC Extensor Carpi Ulnaris Tendon Sheath
The ECU tendon is considered a dynamic stabilizer of the DRUJ. The ECU inserts on the base of the fifth metacarpal and is firmly stabilized in its groove on the ulnar head by a collar of synovium-lined deep fascia (i.e., the sixth extensor compartment of the wrist). This fascial housing may rupture with subluxation of the ECU from its groove during forearm rotation, resulting in ulnar wrist pain. Stress-induced tenosynovitis with partial tendon rupture is another source of chronic problems on the ulnar side of the wrist. The ECU is unique among the wrist extensors, because it changes its relationship to the axis of wrist movements and rests on the ulnar side of the ulnar head during pronation, where it is a strong ulnar deviator. In supination, the ECU is positioned dorsally to maximize its moment arm for wrist extension.
TFCC Affiliates
Located ulnarly are the ulnolunate and ulnotriquetral ligaments (see Fig. 72-1D ), with attachments as their names imply. These ligaments complement the function of the TFCC. They stabilize the ulnar carpus and prevent its palmar migration, and when disrupted can be a component of midcarpal instability.
Midcarpal Instability
Carpal instability of the proximal row, specifically of the nondissociative variety, known as CIND and often referred to as ulnar midcarpal instability , must be considered when trying to identify the cause of ulnar wrist pain. The pathomechanics of CIND have been poorly delineated, because there is still no consensus as to whether the problem is limited to the midcarpal joint or occurs in combination with a radiocarpal instability. Needless to say, the CIND clinical presentation mimics TFCC problems in that instability is coupled with ulnar wrist pain, a snap or clicking is associated with wrist motion, and there is a weakness of grip. Most patients with CIND have a normal radiographic appearance, but some may exhibit an abnormal palmar intercalated segment instability resting posture. Pain and clicking or clunking sounds associated with moving the wrist in a circle or from radial to ulnar deviation is a classic sign, and this should be coupled with a dynamic subluxation (demonstrated on videofluoroscopy) and a sudden dramatic shift in the position of the proximal carpal row. This painful audible sensation can be eliminated by mechanically positioning the triquetrum dorsally back onto the appropriate facet of the hamate (by pushing the pisiform dorsally) when moving the wrist in a circular or deviated fashion.
Pisotriquetral Joint
Pisotriquetral arthritis is another source of ulnar wrist pain that is easily ferreted out clinically and radiographically. Direct tenderness on the palmar ulnar side of the wrist over the pisiform suggests pisotriquetral degenerative joint disease (DJD). This condition is most common in the elderly, unless there is a history of direct injury to the pisiform. The differential diagnosis should also include flexor carpi ulnaris (FCU) tendinitis, which transmits force through the pisotriquetral joint.
Interosseous Membrane
The interosseous membrane is the final stabilizer of the DRUJ and plays an important role in transmitting axial forces from the radius to the ulna while preventing lateral separation of the two forearm bones. The interosseous membrane shares a role with the pronator quadratus muscle in preventing abnormal translation of the distal radius relative to the ulna, a stabilizing effect of equal or greater importance than the action of the TFCC. Ulnocarpal abutment may result if a radioulnar length discrepancy exists secondary to an unstable fracture or surgical excision of the radial head. Complex injuries, such as the Essex–Lopresti injury, which consists of a radial head fracture with dislocation of the DRUJ secondary to proximal migration of the radius (due to disruption of the interosseous membrane), can also lead to ulnar wrist pain and persistent DRUJ instability.
An Algorithmic Approach to the Management of Ulnar Wrist Pain and Impairment
With the anatomic and pathomechanical background now in place regarding the structures that can lead to ulnar wrist pain and impairment, it is time to initiate the clinical problem solving. To start, the clinician must mentally formulate a list of structures that can cause ulnar wrist pain. Then the clinician should rule out all structures that are not contributing to the ulnar wrist pain and focus the therapy toward the structure that has been identified. To do this, one might find an algorithmic approach to be helpful. In this section, the tenets of the evaluation are discussed and an algorithm is presented that identifies and describes the (1) ulnar wrist problems, with the structure and/or diagnostic entity listed; (2) provocative maneuvers for specific lesions; and (3) suggested general conservative treatment options.
The triage evaluative process of taking a thorough history, performing a meticulous physical examination, and corroborating these findings with imaging studies is the hallmark of the assessment of wrist pain. Before working through this algorithm, it would be useful to consider the following evaluation tenets that can be extremely helpful in the management of patients with TFCC and/or TFCC-related problems.
Tenets of the Evaluation
History and Mechanism of Injury
During the history, traumatic events should be well defined and some description of the mechanism of injury can be helpful. If the wrist pain seems to be insidious in onset or of an atraumatic nature, congenital, degenerative, or avascular problems may be presenting themselves. A complete medical history, emphasizing any past surgeries, fractures, related joint problems, or metabolic diseases, should accompany the history. In addition, if the wrist condition developed over time, it is important to explore the potential causative vocational or avocational activities. Location of pain, as well as aggravating factors, should also be defined.
Typically, axial loading, either via falls on the outstretched hand or gripping, coupled with forearm rotation is the mechanism associated with ulnar-sided lesions and TFCC tears. Bowers has identified carpal hypersupination with ulnar deviation in ECU instability and hyperpronation and dorsiflexion in LT injuries. Taleisnik also believes that carpal hyperpronation is responsible for isolated ulnar instabilities. The TFCC also seems to be vulnerable to injury when the wrist complex is in full pronation.
Often, patients will have ulnar-sided pain that is recalcitrant. That is, despite their best efforts at resting the wrist on their own and practicing benign neglect, or in some cases having experienced unsuccessful hand therapy sessions, they still have the same pain with either gripping, deviating the wrist, or rotating the forearm (or all three actions simultaneously). They may be experiencing a clicking sensation and perhaps even some dysesthesias along the ulnar side of the wrist-hand. Some patients may even offer the following: “It is like something just isn’t healing in there.”
Physical Examination with Provocative Maneuvers
The physical examination should include a generalized assessment of edema, range of motion (ROM), strength, sensation, and function, as well as include specific provocative maneuvers. The purpose of using clinical provocative maneuvers is to precipitate symptoms, signs, or other findings that aid in the diagnosis of ulnar wrist pain and impairment.
Physical Examination and Provocative Maneuver Considerations
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The examination progresses from the least tender region noted from the patient’s history to the most symptomatic region.
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The examination starts with active ROM (AROM) and progresses to passive ROM (PROM), isometric resistive tests, and provocative maneuvers, and ends with palpation.
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The purpose of a provocative maneuver is to provoke symptoms. Therefore, these assessment techniques should be performed with vigor.
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Provocative maneuvers that are predicted to be painful to the patient should be the last maneuvers performed.
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Typically, the patient can describe, and should perform, the task or maneuver that precipitates symptoms.
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At a minimum, the physical examination should always be supplemented with radiographic images so that the integrity, relationships, and contours of the wrist’s osseous structures can be better assessed.
Algorithm
The algorithm ( Fig. 72-5 ) lists six general diagnostic categories from which more specific lesions are identified. These general categories include (1) fracture, (2) degenerative, (3) instability, (4) tendinitis, (5) TFC–articular disk tears, and (6) ulnar nerve compression. This section starts at each general diagnostic category and works down the algorithm through the specific lesions, along the way identifying the salient aspects of the history and physical examination/provocative assessment that will help rule in or rule out a specific lesion. Each diagnostic category will have at least one provocative maneuver described; however, readers should refer to Chapter 7 for a more thorough assessment approach.
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