The Distal Radioulnar Joint: Anatomy and Management of Disorders

Rachel Jaffe, OTRJL, CHT University of Florida Department of Orthopaedics Orthopaedic Hand Therapy Gainesville, Florida

Larry K. Chidgey, MD University of Florida, Department of Orthopaedics, Hand Division, Gainesville, Florida

Paul C. LaStayo, MPT, CHT DeRosa Physical Therapy, PC Flagstaff Arizona Northern Arizona University Department of Biological Sciences Flagstaff Arizona

T raumatic injuries, inflammatory processes, and degenerative conditions of the distal

radioulnar joint (ORUJ) can produce ulnar-sided wrist pain, instability restricted forearm motion, and decreased grip strength. The ulnar side of the wrist has been likened to the lower back because both clinical entities are often problematic when trying to establish a clear diagnosis. However, due to research efforts over the last several years, our knowledge and understanding of the anatomy and biomechanics of the ORUJ have improved. This in tum has yielded more effective assessment and treatment methods for the many pathologic condi­tions seen on the ulnar side of the wrist.

ANATOMY AND BIOMECHANICS

Forearm rotation occurs through the articula­tion of the ulnar head and the sigmoid notch of the radius distally and the radial head and ulna prox­imally. The ORUJ should be viewed as one part of the "forearm joint." Abnormalities throughout the forearm (malunions of the radius or ulna, radial head fractures with intraosseous membrane disrup­tion, etc.) can have a marked effect on the ORUJ articulation, and by broadening the focus to the en-

Correspondence and reprint requests to Rachel Jaffe, OTR/L, CHT, University of Florida, Department of Orthopaedics, Hand Division, Box 100246 JHM Health Center, Gainesville, FL 32610.

FIGURE 1. The triangular fibrocartilage complex (TFCC) viewed from the dorsal side of the wrist. (A) Intact TFCe. The extensor carpi ulnaris (ECU) sheath extends farther than drawn, all the way to the fifth metacarpal, with connections to the triquetrum and hamate. (B) The ECU sheath has been removed along with its thickened floor (also referred to as the ulnar collateral ligament). The meniscus homologue (MH) originates from the dorsal margin of the radius and sweeps palmar and ulnar to insert into the palmar/ulnar aspect of the triquetrum. Along its course it has fibers inserting into the ulnar styloid. As the MH sweeps past the styloid and the palmar radioulnar ligament, it forms the dorsal roof of the prestyloid recess (PR), a synovial-lined recess that variably connects to the palmar aspect of the ulnar styloid. (C) The MH has been removed so the entire TFC praper {aritcular disk (AD), palmar radioulnar ligament (PRUL), and dorsal radioulnar ligament (DRUL)] can be seen. There are 2 insertion sites into the ulna, the fovea at the base of the ulnar styloid and the styloid itself. (D) The TFCC has been removed. The ulnolunate (UL) and ulnotriquetral (UT) ligaments extend from the palmar aspect of the respective carpal bones and the lunotriquetral interosseous ligament to the ulna, inserting into the foveal area and the base of the ulnar styloid.

April-June 1996 129

FIGURE 2. (A) Trans­verse histologic section of the junction between the dorsal radioulnar liga­ment (D) (top half of photo), which has lon­gitudinally oriented col­lagen fiber bundles, and the articular disk (bot­tom half), which has short, randomly oriented collagen fiber bundles. (B) The collagen fibers in the central articular disk form a strong "basket­weave" pattern. Part B is used with permission from: Chidgey LK: Histologic anatomy of the triangular fibrocartilage. Hand Clinics 7:252, 1991.

Dofsal branch of anterior

interosseus artery

Ulnaratery

Palmar branch ofantertor

Interosseus artery

, :~--'J/-Intraosseus vessels

FIGURE 3. The dorsal and palmar radioulnar ligaments and the peripheral 20% of the articular disk have a good blood supply through branches of the anterior interosseous artery, the ulnar artery, and medullary interosseous arteries penetrat­ing through the bone of the ulnar head in the fovea area.

tire forearm, potential pitfalls in diagnosis and treatment can be avoided. During normal supina­tion and pronation, both a rotational motion and a sliding motion occur at the DRUJ. The radius and the hand rotate up to 1500 about a relatively stable ulna.1-4 The ulnar head is not immobile during forearm rotation; rather, it translates dorsally and palmarly within the sigmoid notch of the radius.3

-s

130 JOURNAL OF HAND THERAPY

The ulna shifts dorsally in pronation and palmarly with supination. There is also a relative proximal distal migration of the ulnar head in the sigmoid notch with supination and pronation.s,6 As the fore­arm moves from supination to pronation, the ulnar head shifts distally within the sigmoid notch.

The DRUJ is separated from the radiocarpal joint by the triangular fibrocartilage complex (TFCC) (Fig. 1). The FTCC is comprised of the ar­ticular disk, the dorsal and palmar radioulnar lig­aments, the meniscus homologue, and the extensor carpi ulnaris sheath.3 The dorsal and palmar ra­dioulnar ligaments are formed by longitudinally oriented collagen fiber bundles originating and in­serting directly into bone, as other ligaments in the body (Fig. 2A).7 The articular disk is composed of fibrocartilage and originates from the hyaline car­tilage of the distal radius articular surface. The col­lagen fibers of the central portion of the disk are oriented in waves such that they form a strong bas­ket-weave pattern (Fig. 2B).

The dorsal and palmar radioulnar ligaments and the peripheral 20% of the articular disk have a good blood supply (Fig. 3)/ via branches of the anterior interosseous artery, the ulnar artery, and medullary interosseous arteries penetrating through the bone of the ulnar head in the fovea area. The central 80% of the articular disk is avas­cular.7 Because of this vascular arrangement, pe­ripheral tears have a vascular potential to heal while central tears either have no healing potential or must rely on other methods of healing besides vascular invasion.

Palmer and Werner described the TFCC as the major support system of the DRUJ.8 The dorsal and palmar radioulnar ligaments are the primary sta­bilizers of the ulna within the sigmoid notch, pre­venting ulnar subluxation or dislocation during forearm rotation?,8,9 Opinions differ over which of these ligaments stay lax or become taut during su­pination and pronationYO-12 During full supina­tion, the ulnar head tends to ride out of the sigmoid notch in a palmar direction. The dorsal radioulnar

ligament becomes tight with attempted palmar subluxation of the ulnar head and thus is the pri­mary stabilizer in forearm supination. With forearm pronation, the ulnar head rides dorsally in the sig­moid notch and the palmar radioulnar ligament be­comes tight, preventing the ulnar head from dis­locating dorsally in this position.

Although not included as part of the TFCC, the palmar ulnolunate and the ulnotriquetralligaments play an important role in stabilizing the ulnar car­pus relative to the ulna. These ligaments prevent volar subluxation of the ulnar carpus relative to the distal ulna. Clinically, if these restraining structures are disrupted (Le., trauma or rheumatoid arthritis), the ulnar carpus is free to supinate relative to the radius and the ulna.1,13

Forces across the wrist are significant, with the radius carrying approximately 80% of the axial load, while 20% is borne across the ulnar side.14 Al­terations in the normal relationship of the distal ulna to the distal radius significantly change the distribution of axial 10ads.1,3,B,14 Ulnar variance, de­fined as the length of the ulna relative to the radius, differs among individuals (Fig. 4). This difference may be the result of the natural relative growth of the radius, compared with that of the ulna, or may be secondary to an acquired deformityY,s.s When the radius and the ulna are the same length, the ulnar variance is zero or neutral. When the ulna is longer than the radius, an ulnar-positive variant is observed, and when the ulna is shorter than the radius, an ulnar-negative variant is present. Ulnar variance is not static; rather, it changes with fore­arm position and with power grip.4,5,B,9 The radius moves proximally in relation to the ulna in prona­tion and distally in supination, resulting in a rela­tively more positive variance in pronation than in supination. Power grip may increase ulnar variance by 1-2 mm. Even subtle changes in ulnar variance can unduly stress the ulnar structures by exceeding their physiologic loads. For instance, ulnar length­ening of 2.5 mm has been reported to double the load on the distal ulna to 42% of the total axial 10ad.14 This may be extremely important clinically when an individual axially loads his or her wrist while pronating the forearm and/ or ulnarly devi­ating the wrist, because it may exceed the physio­logic load-bearing characteristics of ulnar-sided structures.

INJURIES AND DISORDERS

Injuries and disorders of the DRUJ are numer­ous and can vary in complexity. Trying to identify and locate where the lesion is within the DRUJ can be difficult. Through an appropriate history and physical examination, however, as well as imaging and other diagnostic studies, the clinician should be able to determine where the pathology is lo­cated. We focus on the most common disorders of the DRUJ: TFCC injuries, distal radius fractures in­volving the DRUJ, instability/dislocations, and ar­thritis.

FIGURE 4. Ulnar variance is measured on a standardized posteroanterior (PA) radiograph. A line perpendicular to the longitudinal axis of the radius is drawn at the level of the subchondral bone of the lunate fossa of the radius. The distance the distal-most portion of the ulnar head extends above or be­low this line is the ulnar variance. In this case there is a 1-mm positive ulnar variance. Reproduced with permission from: Chidgey LK: The distal radioulnar joint: problems and solu­tions. JAm Acad Orthop Surg 3:95-109, 1995.

TABLE 1. Classification of Triangular Fibrocartilage Complex (TFCC) Injuries*

CLASS I-Traumatic A. Central perforation B. Medial avulsion (ulnar attachment)

With distal ulnar fracture Without distal ulnar fracture

C. Distal avulsion (carpal attachment) D. Lateral avulsion (radial attachment)

With Sigmoid notch fracture Without sigmoid notch fracture

CLASS 2-Degenerative (ulnocarpal impaction syndrome) Stage 1. TFCC wear

Stage 2. TFCC wear + Lunate and/or ulnar chondromalacia

Stage 3. TFCC perforation + Lunate and/or ulnar chondromalacia

Stage 4. TFCC perforation + Lunate and/or ulnar chondromalacia + Lunotriquetral ligament perforation

Stage 5. TFCC perforation + Lunate and/or ulnar chondromalacia + Lunotriquetral ligament perforation + Ulnocarpal arthritis

*Reprinted with permission from: Palmer AK: Triangular fibro­cartilage complex lesions:. A classification. J Hand Surg [Am] 14:594-606, 1989.

April-June 1996 131

Ulna

Radius

Ulna

Radius

FIGURE 5. Class 1A central traumatic tear, usually 1-2 mm from the articular surface of the radius. Reproduced with permission from: Palmer AK: Triangular fibrocartilage complex le­sions: A classification. J Hand Surg [Am] 14: 594-606, 1989.

FIGURE 6. Class 1B ulnar avulsion of the tri­angular fibrocartilage complex, which may be associated with an ulnar styloid fracture. Repro­duced with permission from: Palmer AK: Tri­angular fibrocartilage complex lesions: A clas­sification. J Hand Surg [Am] 14:594-606, 1989.

FIGURE 7. Class 1e distal tear is a disruption of the ulnocarpal liga­ments. Reproduced with permission from: Palmer AK: Triangular fibrocar­tilage complex lesions: A classification. J Hand Surg [Am] 14:594-606, 1989.

132 JOURNAL OF HAND THERAPY

TFCC Injuries

Injury to the TFCC is a commonly recognized cause of ulnar-sided wrist pain. Palmar classifies TFCC injuries into 2 broad categories, traumatic and degenerative lesions (Table 1).13 Traumatic in­juries, which are less common than degenerative lesions, are categorized based on the location of the pathology. Traumatic tears to the TFCC can occur from a fall on the outstretched, pronated hand, an excessive rotational force to the forearm, and! or an axial load or distraction injury to the ulnar wrist. 1.2.12

Traumatic tears of the articular disk commonly occur along the origin of the articular disk from the radius. These tears are class lA injuries according to Palmer's classification (Fig. 5). The central 80-85% of the articular disk is avascular and, therefore, tears in this area have minimal healing potential.7

Traumatic avulsion of the insertion of the TFCC onto the ulna describes class IB lesions (Fig. 6). These injuries are seen with or without fractures of the ulnar styloid. Avulsions of the TFCC ulnar at­tachment often create DRUJ instability. Disruption of the TFCC distally through the ulnolunate and ulnotriquetral ligaments are classified as Class lC lesions (Fig. 7). This area is well vascularized; there­fore, lesions in these regions have greater potential to heal. Class ID injuries are less common and in­volve a radial avulsion of the entire TFCC from its attachment to the radius at the sigmoid notch (Fig. 8). This involves avulsion of not only the articular disk but also the dorsal and palmar radioulnar lig­aments. Therefore, this renders the DRUJ unstable.

Palmer's class 2 tears represent degeneration of the central portion of the TFCC and represent the spectrum of lesions found with ulnocarpal impac­tion syndrome (Fig. 9). Degeneration of the TFCC is linked to a positive ulnar variance.3

,13,1S,16 The ul­nar-positive posture results in pinching of the cen­tral portion of the articular disk between the ulnar head and the ulnar carpus. The central portion de­generates under this increased load, which may also result in lunotriquetral ligament tears and as­sociated arthritis. Symptoms may be worsened by

FIGURE 8. Class 1D lesions are different from class 1A lesions in that ID lesions not only in­volve the articular disk, but the dorsal and pal­mar radioulnar liga­ments are also avulsed from the radius. Repro­duced with permission from: Palmer AK: Tri­angular fibrocartilage complex lesions: A clas­sification. J Hand Surg [Am] 14:594-606, 1989.

Radius

Ulna

FIGURE 9. Radiograph of a patient with advanced ulno­carpal impaction syndrome. The ulnar head and the lunate are involved in the arthritic changes (arrowheads). The central portion of the triangular fibrocartilage complex is perforated as well.

activities that require rotational and ulnar loading of the wrist and forearm. Examples include occu­pations that require repetitive motions, such as as­sembly line worker and grocery clerk, and sports, such as golf and tennis.

Ulnocarpal impaction syndrome progresses through stages.I,3,17,18 Early changes involve wear of the central articular disk and associated chondro­malacia of the lunate, triquetrum, and ulnar head articular surfaces, As wear progresses, the central portion of the disk develops a perforation and a lunotriquetralligament tear occurs secondary to the wear phenomenon. Eventually, ulnocarpal arthritis develops.

On physical examination, patients with TFCC lesions with have pain to direct palpation over the TFCC region, and symptoms may be exacerbated by active and resistive ulnar deviation with forearm rotation as well as forceful gripping,8,17,19 Since ul­nar-positive variance increases with forearm pro­nation in normal subjects, forearm pronation may exacerbate symptoms and possibly decrease grip strength in patients with TFCC lesions.20 This makes sense biomechanically but has not yet been proven, clinically. In outlining treatment options, it is important to distinguish between TFCC lesions that are associated with instability from those that are not. It is also important to distinguish TFCC lesions associated with degenerative arthritis of the DRUJ from those where the articular surfaces are still intact. Ligamentous laxity is assessed by hav­ing the patient place the elbow of the involved arm on a tabletop while pointing the forearm and hand toward the ceiling, while the examiner sits across the table from the patient. With the patient's fore­arm in a neutral position, the examiner grips the

radius with one hand and the ulna with the other hand just proximal to the DRUJ. The examiner then manually translates the ulna and radius past each other in a dorsal and palmar direction (Fig, 10). The amount of translation in a neutral forearm position is compared with the amount of translation occur­ring in full supination and in full pronation.9,19 Typ­ically there is less translation in full supination and pronation compared with neutral. It is also imper­ative to compare the involved extremity with the contralateral side. Individuals have a tremendous variability in the amount of laxity they normally have in DRUJ, Arthritic changes of the DRUJ are assessed by supinating and pronating the forearm while the examiner squeezes the radius and ulna together.21 Pain and crepitation produced by com­pressing the joint surfaces together should make the examiner suspicious of associated arthritic changes,

Diagnostic studies to evaluate TFCC pathology, as well as other DRUJ abnormalities, should in­clude standard radiographs. The posterio-anterior (PA) radiograph should be taken in the standard ulnar variance position as described by Hardy et al.22 The arm is positioned with the shoulder at 90° of abduction, the elbow at 90° of flexion, and the forearm in a neutral supination/pronation po­sition, With this view the ulnar styloid projects along the ulnar border of the ulna. Using a stan­dard view with consistent ulnar styloid orientation avoids confusion when comparing later radio­graphs and evaluating the status of ulnar variance, In evaluating suspected ulnocarpal impaction syn­drome, an additional PA radiograph with the fore­arm in full pronation and the patient gripping while the film is taken may help demonstrate ulnar impaction against the carpus. These maneuvers will increase the ulnar variance, Arthrography of the wrist (the injection of a radiopaque material into the joint) may help demonstrate tears in the TFCC as well as the lunotriquetral ligament.23-26 Perfora­tions of these ligamentous structures found on ar­thrography must be correlated with a patient's symptoms, Mikic demopstrated that perforations in the TFCC occur as a natural process of aging.Is By

FIGURE 10. To assess distal radioulnar joint sta­bility, the examiner sits across the table from the pa­tient while the patient rests the elbow of the involved arm on the table with the hand pointed to the ceiling. The examiner stabilizes the patient's radius with one hand and the ulna with the other and tries to manually translates the radius and ulna past each other, There is normally more transla­tion in the neutral forearm position than in full supi­nation and full pronation.

April-June 1996 133

FIGURE 11. A sugar-tong splint is often used to block fore­arm rotation yet allow flexion and extension of the elbow.

50 years of age, almost 50% of normal indiv~duals have perforations within the TFCC. MagnetIc re.s­onance imaging (MRI) has also proved useful In demonstrating TFCC abnormalities.27- 29 In some in­stitutions, MRI has supplanted arthrography. Ar­throscopy of the writs has also proven useful a~ a diagnostic too1.30 It not only offers the opportumty to inspect the TFCC and intercarpal l~game~ts for signs of wear or tear, but ~lso allows InspectIon .of the articular surfaces for SIgnS of chondromalacIa. No other diagnostic modality offers the opportu­nity for direct inspection of a lesion.

Treatment of TFCC injuries not associated with instability should initially be conservative: This i~­volves splinting in neutral forearm rotatIon, antI­inflammatory medications, and activity modifi~a­tion.l7,l8 After a trial of 3-6 months of conservatIve measures, surgical intervention may be considered. Prior to surgical intervention, further diagnostic studies may be required to feel confident about a diagnosis. Arthroscopic debridement of central traumatic tears has yielded up to 75% good re­sults.3l,33 Up to two-thirds of the central portion of the articular disk can be removed without compro­mising the stability of the DRUJ.34 If a central tear is associated with an ulnar-positive variant, then concomitant ulnar shortening should be carried out. One way this may be accomplished is by re­secting a portion of the ulnar h.ea~,. either ~rthros­copically or through an open InCISIon. ThIS tech­nique has been described by Feldo~ et aP5 Anot~er method is to shorten .the ulna wIth a shortenIng osteotomy in the distal diaphyseal portion of the uh1.a. A 2-3-mm segment of the ulna is resected and the shortened ulna fixed with a plate and screws.1 Avulsions of the ulnar attachment of the TFCC with or without an associated ulnar styloid fracture can be fixed with sutures placed through drill holes in the distal ulna or with suture anchors. l

Pinning of a large ulnar styloid fragment is also a useful technique.

Treatment of ulnocarpal impaction syndrome in its early stages centers around shortening the ulna.u8 For later stages, one of the procedures to

134 JOURNAL OF HAND THERAPY

address arthritic changes, as described later, can be used. Debridement of associated degenerative TFCC tears has not clearly been shown to improve the results so long as an adequate shortening is car­ried out.

Distal Radius Fractures

Perhaps because of their frequency, distal ra­dius fractures are often treated with less respect than they deserve. Although traditionally associ­ated with a high union rate, these injuries also have a relatively high complication rate. l,36-38 Because at­tention is often directed primarily at the radiocar­pal joint, the clinician ~ay fail to apprec~ate. the importance of fracture displac~ment extendIng I~t? the sigmoid notch of the radIUs. Often the chm­cian's index of suspicion is low for associated DRUJ instability or dislocation after a distal radius frac­ture. A distal radius fracture with a displaced sig­moid notch, either palmarly or dorsally, should alert the clinician to possible DRUJ instability.l,37 Ul­nar styloid fractures often occur concomitantly with fractures of the distal radius and fc0tentially may represent class IB TFCC avulsions .. 3 An especia~ly high index of suspicion should eXIst when a dIS­placed fracture at the base of the ulnar styloid is seen. The goal of treatment is to successfully reduce the fracture, restore radial length and volar tilt to the radius, and address any joint incongruity or in­stability at both the radiocarpal joint and the DRUj.1,37-38 Adequate reduction of the distal radius and DRUJ may require external or internal fixation. Complications following distal radius fractures are common. A high proportion of unsatisfactory treat­ment outcomes are secondary to the shortened position of the distal radius, with an associated positive ulnar varianceYs This often produces symptoms of ulnocarpal impac.tion syndrome. ~er­sistent pain over the DRUJ dUrIng forearm rotation or radiocarpal motion during rehabilitation war­rants further investigation. Restoration of normal mobility, strength, ~nd stability ~s impossibl~ ~f t~e articular surfaces are compromIsed or stabIhty IS lost.

Therapeutic intervention should be initiated early during fracture healing. Ede~a management, tendon gliding exercises, and actIve range of mo­tion (ROM) of the uninvolved joints can be started as soon as fracture fixation is achieved.39 Forearm rotation is contraindicated with unstable intra-ar­ticular fractures of the DRUJ, healing TFCC repairs, and fractures at the base of the ulnar styloid. Fore­arm motion initiated too early may compromise fracture reduction or healing soft tissues, A sugar­tong splint can be fabricated to immobilize the DRUJ if needed (Fig. 11).

Instability/Dislocations

Dislocation of the DRUJ may occur as an iso­lated injury; however, more often it is associated with a concomitant forearm fracture. Goldberg

et al. reported that in a review of forearm injuries, 2 or more sites of injury are routine and the DRUJ is affected in 60% of patients.4o Dislocations occur both palmarly and dorsally. 1 Acute dorsal disloca­tions of the DRUJ are more common than volar dis­locations and occur due to a forced hyperpronation injury. Physical examination elicits limited supina­tion and a prominent ulnar head dorsally. Forced hypersupination can produce a volar dislocation that results in limited pronation and a dimple in the skin seen dorsally. Complete dislocation is usu­ally obvious on a true lateral radiograph; however, there is a potential pitfall in diagnosing subluxation of the DRUJ on the basis of a single lateral radio­graph. Even small amounts of forearm rotation away from the true lateral position can make the normal DRUJ appear subluxed. A computed to­mography (CT) scan through the DRUJ is the best diagnostic study for subtle DRUJ subluxation.41

Clinically, DRUJ stability can be assessed by asking the patient to actively rotate the forearm with the elbow stabilized, while the examiner notes any gross subluxation of the distal ulna. The examiner also evaluates passive ROM to assess end feel. Lo­calized pain with active or passive motion suggests DRUJ involvement and warrants further investi­gation. Ligamentous laxity as previously described should also be assessed in the neutral, full supi­nated, and full pronated positions.

Acute DRUJ dislocation/instability may be treated conservatively if a concentric closed reduc­tion can be accomplished.42 For dorsal dislocations the arm is immobilized in supination for 6 weeks in a long arm cast with the elbow at 90°. If the ulna is displaced volarly, then reduction is followed by immobilization in pronation. Some authors advo­cate a neutral forearm position following reduction to avoid unequal stresses on the various stabilizing structures so long as a concentric reduction can be maintained in a neutral position. I ,17 After immobi­lization, active ROM exercises are initiated within the patient's pain tolerance for forearm rotation and wrist motion. Thermal modalities such as moist heat or Fluidotherapy may be helpful as precon­ditioning techniques, for relaxation, or for pain modulation prior to exercise.43

,44 Maintaining DRUJ stability while regaining ROM is a primary goal of therapy. Attenuation or inflammation of healing tis­sues can be avoided by monitoring changes in pain status, edema, and joint subluxation. A removable sugar-tong splint or a wrist control may be ordered to wear between exercises as needed for comfort. If joint congruity is maintained but return of motion is limited by soft-tissue restraints (such as capsular tightness or scar adhesions) that fail to respond to a progressive exercise program, splinting can be a valuable adjunct. Either static-progressive or dy­namic supination-pronation splinting can be used to improve passive ROM. Another option is to con­sider serial casting for progressive gains in motion. However, overaggressive splinting or serial casting without regarding patient tolerance or principles of wound healing can be counterproductive.

If a concentric reduction cannot be accom-

FIGURE 12. Surgical procedures described for treating the arthritic distal radioulnar joint (cross-hatched area represents the bone to be resected). (A) Darrach procedure. (B) Herniresection - interposition technique. (C) Suave-Kapandji procedure.

plished in a closed fashion, or if the instability is chronic, then surgical repair or ligamentous recon­struction is in order. 1 Prior to considering surgical repair or ligament reconstruction, a full assessment of the articular surfaces should be made. Ligamen­tous reconstruction and repair alone are contrain­dicated if there is associated posttraumatic arthri­tis. I In many cases there is adequate substance to the remaining dorsal and palmar radioulnar liga­ments for them to be mobilized and reattached to the ulnar styloid region. However, if these tissues have contracted substantially, then formal ligament reconstruction with tendon graft may be needed. Scheker et a1. described a surgical procedure to re­construct the dorsal or palmar radioulnar ligament utilizing a palmaris longus tendon graft.45 Prelimi­nary reports have shown good results with this technique. Six weeks of immobilization of the fore­arm is required after surgical reattachment or lig­ament reconstruction prior to initiating rehabilita­tive exercises.

Arthritis

The DRUJ is a frequent site of early involve­ment in rheumatoid arthritis. This joint may also be involved with posttraumatic arthritis as well as os­teoarthritis. On clinical examination, patients with rheumatoid arthritis show signs of ligamentous lax­ity with dorsal subluxation of the distal ulna and supination of the carpus and hand on the end of the forearm.46,47 The combination of synovitis of the joint and erosive bony changes may cause wear and destruction of the overlying tendons.46-48 Rupture of the extensor tendons (especially the extensor dig­iti minimi) is a common sequela. Patients with all forms of arthritis of the DRUJ may have limited forearm rotation, pain with active motion, and lim­ited grip strength.'l6 Clinically, the examiner can ex­acerbate pain by compressing the radius and ulna together.21 Crepitation may be elicited with forearm rotation. Arthritic changes can be seen on standard radiographs, and other diagnostic studies are rarely needed. Assessing the stability of the DRUJ is im­portant when considering treatment options.

Conservative management can include non­steroidal anti-inflammatory drugs, splinting in a position of comfort to prevent forearm rotation, and/ or local steroid injections.46-5o

April-June 1996 135

FIGURE 13. A dynamic supination-pronation splint using Rolyan (Smith & Nephew Rolyan, Germantown, WI) com­ponents.

Surgical procedures have been directed at elim­inating the painful joint surface (Fig. 12). These have included the Darrach procedure, the hemire­section arthroplasty technique, and the Sauve-Ka­pandji procedure. With the Darrach procedure the entire ulnar head is resected. Instability of the re­maining distal ulna stump with associated pain has been an associated problem postoperatively.51 The hemiresection arthroplasty technique as described separately by Bowers52 and by Watson et aP3 in­volves resecting only the articular surface of the ul­nar head. The ulnar styloid is left intact with its connection to the TFCC. This procedure has been used in an attempt to help maintain stability of the distal ulna through this distal ulnocarpal axis. The Suave-Kapandji procedure fuses the ulnar head to the sigmoid notch of the radius, and a 2-cm seg­ment of the distal ulna is resected to maintain fore­arm rotation.54 All 3 of these procedures have shown excellent results in patients with rheumatoid arthritis.52,55,56 Patients with posttraumatic arthritis and osteoarthritis have not shown results compa­rable to those for rheumatoid patients.

THERAPEUTIC MANAGEMENT OF THE DRUJ

Based on the above described entities, all of which can affect DRUJ function, injury to the DRUJ can vary in complexity; however, the same general principles of rehabilitation can be applied for all etiofogies.

Direct communication with the referring phy­sician with regard to the mechanism of injury, the affected structures, treatment to date, and any sur­gical intervention rendered is essential in formulat­ing therapeutic guidelines. Observing wound heal­ing principles and respecting pain are basic to functional results. Working within pain tolerance is important to avoid exacerbation of symptoms and avoid disruption of healing tissues.

Thermoplastic splints are often used to immo-

136 JOURNAL OF HAND THERAPY

FIGURE 14. A hammer can be used as a passive weight stretch for forearm rotation. A wrist-support splint can be used to block carpal rotation.

bilize the DRUJ. The position and length of im­mobilization following injury or surgical interven­tion are determined by the referring physician based on diagnosis. In many instances, therapy may not be involved until weeks after injury. For example, with frank DRUJ dislocations, often if a concentric reduction is obtained, a referral to ther­apy may not occur until after cast immobilization for 6 weeks. With distal radius fractures involving the DRUJ, however, therapy may be started early to manage edema, to facilitate ROM to the unin­volved joints, or for adjunctive splinting.39 If fore­arm rotation is contraindicated, a sugar-tong splint can be fabricated (in many cases around an external fixator) to block supination and pronation yet allow elbow flexion and extension. A wrist support splint used between exercises may be all that is required following TFCC debridement of a central tear.32

With degenerative changes, splinting in the posi­tion of comfort, whether it be a wrist support alone or a splint that blocks forearm rotation, often tem­porarily relieves symptoms. In the early stages of ulnocarpal impaction syndrome, a wrist-support splint may suffice.3 Finally, if improving passive ROM is the goal, and there is no evidence of a bony or mechanical block, other methods of splinting can be used to restore forearm rotation. For instance, a dynamic supination-pronation splint (Fig. 13) can be fabricated to apply intermittent force using rub­berband components to improve passive motion. Another option is to use a static-progressive splint that positions the tissue at its maximum length and holds it there for a prolonged period. These splint­ing methods work by applying a low-load, pro­longed stress to shortened connective tissue, which has been shown to permanently elongate tissue, ul­timately improving passive ROM.57

-60

Active forearm rotation exercises are initiated as soon as possible. Pain is often the limiting factor in determining how quickly active-assistive exer­cises and passive ROM are incorporated. As pain diminishes, other exercise techniques such as pas­sive weight stretching can be added. One method

of achieving a passive stretch is to use a tool such as a hammer. The arm is positioned in full adduc­tion with the elbow at 90° and the forearm at neu­tral. The hammer head acts as a fulcrum to rotate the forearm in the desired direction. The amount of leverage and the weight of the hammer used to passively rotate are controlled by where the patient grasps the handle. A wrist-support splint worn during this stretch can be used to avoid rotation of the carpus versus along the forearm axis (Fig. 14). When a gentle, low-load stretch is applied fre­quently throughout the day, small changes in ROM can occur. Incorporating thermal modalities with a passive stretch can be used as a preconditioning technique and may provide transient changes in ROM.61

-64 For permanent changes, however, splint­

ing techniques that provide a longer total end range time are necessary. Goniometry is used to monitor changes in ROM and to monitor efficacy of treat­ment.65 The BTE work simulator can be added for active exercise alone or with added resistance as the patient progresses. Tools emphasizing forearm ro­tation, wrist motion, and grip strength can be used to improve overall function and strength. Strength changes can be documented using tools requiring forearm rotation in the isometric mode on the work simulator.

CONCLUSIONS

Pathology surrounding the DRUJ continues to challenge surgeons and therapists. Ulnar-sided wrist pain has multiple causes, including trauma, inflammatory reactions, and degenerative condi­tions, all of. which can lead to decreased ROM, strength, and function. Early accurate diagnosis with a thorough understanding of the anatomy in­volved is essential to successful treatment. Further research is needed to scientifically validate the re­sults of specific treatment methods for the DRUJ.

REFERENCES

1. Bowers WH: Distal radioulnar joint. In Green DP (ed): Op­erative Hand Surgery, 2nd edition. New York, Churchill Livingstone, 1988, pp 939-989.

2. Bowers WH: Problems of the distal radioulnar joint. Adv Orthop Surg 1:289, 1984.

3. Palmer AK: The distal radioulnar joint. Hand Clin 3:31-40, 1987.

4. Ekenstein FW, Palmer AK, Glisson RR: The load on the ra­dius,and ulna in different positions of the wrist and fore­arm. Acta Orthop Scand 55:363-365, 1984.

5. Palmer AK, Glisson RR, Werner FW: Ulnar variance deter­mination. J Hand Surg [Am] 7:376, 1984.

6. Epner RA, Bowers WH, Gailford WB: Ulnar variance: The effect of wrist positioning and roentgen filming techniques. J Hand Surg [Am] 7:298-305, 1982.

7. Chidgey LK, Dell Pc, Bittar ES: Histologic anatomy of the triangular fibrocartilage. J Hand Surg [Am] 16:1084-1100, 1991.

8. Palmer AK, Werner FW: The triangular fibrocartilage com­plex of the wrist-Anatomy and function. J Hand Surg [Am] 6:153-162, 1981.

9. Bednar JM, Osterman AL: The role of arthroscopy in the

treatment of traumatic fibrocartilage injuries. Hand Clin 10: 605-615, 1994.

10. Schuind F, An K-N, Berglund L, et al: The distal radioulnar ligaments: A biomechanical study. J Hand Surg [Am] 16: 1106-1114, 1991.

11. Ekenstam F, Hagert CG: Anatomical studies on the geom­etry and stability of the distal radioulnar joint. Scand J Plast Reconstr Surg Hand Surg 19:17-25, 1985.

12. Bowers WH: Instability of the distal radioulnar articulation. Hand Clin 7:311-327, 1991.

13. Palmer AK: Triangular fibrocartilage complex lesions: A classification. J Hand Surg [Am] 14:594-606, 1989.

14. Palmer AK, Werner FW: Biomechanics of the distal radioul­nar joint. Clin Orthop 187:26-35, 1984.

15. Mikic ZD: Age changes in the triangular fibrocartilage of the wrist joint. J Anat 126:367-384, 1978.

16. Viegas SF, Ballantyne G: Attritionallesions of the wrist jOint. J Hand Surg [Am] 12:1025-1029, 1987.

17. Drobner WS, Hausman MR: The distal radioulnar joint. Hand Clin 8:631-643, 1992.

18. Friedman SL, Palmer AK: The ulnar impaction syndrome. Hand Clin 7:295-310, 1991.

19. Terill RQ: Use of arthroscopy in the evaluation and treat­ment of chronic wrist pain. Hand Clin 10:593-603, 1994.

20. Altomare P, LaStayo P: Clinical assessment of ulnocarpal impaction syndrome. Presented at the Florida Hand Society annual meeting, Orlando, FL, May 1995.

21. Nagle DJ: Arthroscopic treatment of degenerative tears of the triangular fibrocartilage. Hand Clin 10:615-624, 1994.

22. Hardy DC, Totty WG, Reinus WR, Gilula LA: Posteroanter­ior wrist radiography: Importance of arm positioning. J Hand Surg [Am] 12:504-508, 1987.

23. Palmer AK, Levinson EM, Kuzma GR: Arthrography of the wrist. J Hand Surg [Am] 8:15-23, 1983.

24. Reinus WR, Hardy DC, Totty WG, Gilula LA: Arthrographic evaluation of the carpal triangular fibrocartilage complex. J Hand Surg [Am] 12:495-503, 1987.

25. Hardy DC Totty WG, Carnes KM, et al: Arthrographic sur­face anatomy of the carpal triangular fibrocartilage com­plex. J Hand Surg [Am] 13:823-829, 1988.

26. Zinberg EM, Palmer AK, Coren AB, et al: The triple-injec­tion wrist arthrogram, J Hand Surg [Am] 13:803-809, 1988.

27. Golimbu CN, Firooznia H, Melone CP, et al: Tears of the triangular fibrocartilage of the wrist: MR imaging. Radiol­ogy 173:731-733, 1989.

28. Pederzini L, Luchetti R, Soragni 0, et al: Evaluation of the triangular fibrocartilage complex tears by arthroscopy, ar­thrography, and magnetic resonance imaging. Arthroscopy 8:191-197, 1992.

29. Zlakin MB, Chao Pc, Osterman AL, et al: Chronic wrist pain: Evaluation with high-resolution MR imaging. Radi­ology 173:723-729, 1989.

30. Whipple TL: Arthroscopy of the distal radioulnar joint. Hand Clin 10:589-592, 1994.

31. Osterman AL: Arthr()scopic debridement of triangular fi­brocartilage complex tears. Arthroscopy 6:120-124, 1990.

32. Lucio B, Stokes HM, Poehling GG, et al: Management of isolated triangular fibrocartilage complex perforations of the wrist. J Hand Ther 4:162-168, 1991.

33. Whipple TL, Geissler WB: Arthroscopic management of the athlete: Triangular fibrocartilage tears. J Hand Ther 4:61-63,1991.

34. Palmer AK, Werner FW, Glisson RR, Murphy DJ: Partial excision of the triangular fibrocartilage complex. J Hand Surg [Am] 13:391-394, 1988.

35. Feldon P, Terrono AL, Belsky MR: Wafer distal ulna resec­tion for fibrocartilage tears and/or ulna impaction syn­drome. J Hand Surg [Am] 17:731-737, 1992.

36. Cooney WP, Dobyns JH, Linscheid RL: Complications of Colles' fractures. J Bone Joint Surg Am 62:613-619, 1980.

37. Hollingsworth R, Morris J: The importance of the ulnar side of the wrist in fractures of the distal end of the radius. In­jury 7:263-266, 1976.

38. Palmer AK: Fractures of the distal radius. In Green DP (ed): Operative Hand Surgery, 3 ed. New York, Churchill-Living­stone, 1988, pp 991-1026.

39. Reiss B: Therapist's management of distal radial fractures. In Hunter J, et al (eds): Rehabilitation of the Hand: Surgery and Therapy, 4th ed. St. Louis, Mosby, 1995, pp 337-352.

April-June 1996 137

40. Goldberg HD, Young JW, Reiner 81, Resnik CS, Gillespie TE: Double injuries of the forearm: A common occurrence. Radiology 185:223-237, 1992.

41. Wechsler RJ, Wehbe MA, Rifkin MD, Edeiken J, Branch HM: Computed tomography diagnosis of distal radioulnar sub­luxation. Skel Radiol 16:1-5, 1987.

42. Aulicino PL, Siegel JL: Acute injuries of the distal radioul­nar joint. Hand Clin 7(2):283-293, 1991.

43. Michlovitz SL: Biophysical principles of heating and super­ficial heat agents. In Michlovitz S (ed). Thermal Agents in Rehabilitation. Philadelphia, F. A. Davis, 1986, pp 88-108.

44. Mullins PT: Modalities in upper extremity rehabilitation. In Hunter J, et al (eds): Rehabilitation of the hand: Surgery and Therapy, 3rd ed. St. Louis, Mosby, 1995, pp 1495-1519.

45. Scheker LR, German D, Acosta R: Reconstruction of the dor­sal slip of the triangular fibrocartilage complex. Presented at the ASSH 48th annual meeting, Kansas City, KS, October 1993.

46. O'Donovan TM, Ruby LK: The distal radioulnar joint in rheumatoid arthritis. Hand Clin 5:249-256,1989.

47. Linscheid RL, Dobyns JH: Rheumatoid arthritis of the wrist. Orthop Clin North Am 2:649-665, 1971.

48. Nalebuff EA, Feldon PG, Millender LH: Rheumatoid ar­thritis. In Green DP: Operative Hand Surgery, 2nd ed. New York, Churchill Livingstone, 1988, pp 1655-1766.

49. Bennet RL: Conservative management of the wrist and hand in rheumatoid arthritis: The art of self defense. South Med J 66:1267-1272,1973.

50. Leonard JB: Joint protection for inflammatory disorders. In Hunter ]M, et al (eds): Rehabilitation of the Hand: Surgery and Therapy, 4th ed. St. Louis, Mosby, 1995, pp 1377-1383.

51. Dingman pv. Resection of the distal end of the ulna (Dar­rach operation): An end result study of twenty-four cases. J Bone Joint Surg Am 34:893-900, 1952.

52. Bowers WH: Distal radioulnar joint arthroplasty: The hemiresection-intereposition technique. J Hand Surg [Am] 10:169-178,1985.

138 JOURNAL OF HAND THERAPY

53. Watson AK, Ryu J, Burgess RC: Matched distal ulnar resec­tion. J Hand Surg [Am] 11:812-817, 1986.

54. Sanders RA, Frederick HA, Hontas RB: The Suave-Kapandji procedure: A salvage operation for the distal radioulnar joint. J Hand Surg [Am] 16:1125-1129, 1991.

55. Tulipan DJ, Eaton RG, Eberhart RE: The Darrach procedure defended: Technique redefined and long-term follow-up. J Hand Surg [Am] 16:438-444, 1991.

56. Vincent KA, Szabo RM, Agee JM: The Suave-Kapandji for reconstruction of the rheumatoid distal radioulnar joint. J Hand Surg [Am] 18:978-983, 1993.

57. Brand P: The forces of dynamic splinting: Ten questions be­fore applying a dynamic splint to the hand. In Hunter ]M, et al (eds): Rehabilitation of the Hand, 2nd ed. St. Louis, Mosby, 1984, P 849.

58. Flowers KR, LaStayo P: Effect of total end range time on improving passive range of motion. J Hand Ther 7:150-157, 1994.

59. McClure PW, Flowers KR: Treatment of limited shoulder motion: A case study based on biomechanical considera­tions. Phys Ther 72:929-936, 1992.

60. McClure PW, Flowers KR. Treatment of limited shoulder motion using an elevation splint. Phys Ther 72:57 -62, 1992.

61. Light K, Nuzik S, Personious W: Low-load prolonged stretch vs. high-load brief stretch in treating knee flexion contractures. Phys Ther 64:330-333, 1984.

62. Kisner C, Colby LA: Therapeutic Exercise: Foundations and Techniques. Philadelphia: F. A. Davis, 1990.

63. Warren GC, Lehman JF, Koblanski IN: Heat and stretch pro­cedure: An evaluation using rat tail tendon. Arch Phys Med Rehabil 51:481-487, 1970.

64. Lentell G, Hetherington T, Eagan J: The use of thermal agents to influence the effectiveness of a low-load pro­longed stretch. J Orthop Sports Phys Ther 16:200-207, 1992.

65. Clinical Assessment Recommendations, 2nd ed. Chicago, American Society of Hand Therapists, 1992, pp 60-61.