complex (TFCC) was coined by Palmer and Werner to describe the close anatomic and functional relationships

Transcription

1 Management of Acute Triangular Fibrocartilage Complex Injury of the Wrist Abstract Acute trauma to the triangular fibrocartilage complex includes tears of the fibrocartilage articular disk substance and meniscal homolog as well as radioulnar ligament avulsions, with or without an associated fracture. Patient evaluation includes clinical examination, imaging studies, and wrist arthroscopy (diagnostic). The Palmer classification is typically used to define injuries to the triangular fibrocartilage complex. The critical distinction is in differentiating injuries that produce instability of the distal radioulnar joint from those that do not. Also important is the recognition of acute injuries in the context of an ongoing degenerative pattern (ie, Palmer class 2 lesions). Nonsurgical management includes temporary splint immobilization of the wrist and forearm, oral nonsteroidal anti-inflammatory medication, corticosteroid joint injection, and physical therapy. Surgical strategies include débridement, acute repair, and subacute repair. Most surgical procedures can be performed arthroscopically. However, open ligament repair may be needed in the setting of distal radioulnar joint instability. Dr. Henry is in private practice, Hand and Wrist Center of Houston, Houston, TX. Neither Dr. Henry nor a member of his immediate family has received anything of value from or owns stock in a commercial company or institution related directly or indirectly to the subject of this article. Reprint requests: Dr. Henry, Hand and Wrist Center of Houston, Suite 1200, 1200 Binz Street, Houston, TX J Am Acad Orthop Surg 2008;16: Copyright 2008 by the American Academy of Orthopaedic Surgeons. The term triangular fibrocartilage complex (TFCC) was coined by Palmer and Werner to describe the close anatomic and functional relationships of the soft-tissue structures in the ulnar side of the wrist. 1 The components they delineated were the articular disk, the dorsal and volar radioulnar ligaments, the meniscus homolog, the ulnar collateral ligament, and the sheath of the extensor carpi ulnaris (ECU). Palmer classified the abnormalities into type 1 (A-D) for traumatic injuries and type 2 (A-E) for degenerative conditions that define the progressive spectrum of ulnocarpal impaction. 1 At times, the ulnar side of the wrist has been viewed as having a single anatomic structure of clinical significance (ie, the TFCC). However, several researchers have sought to delineate more precisely the specific functions served by the individual components. Anatomy Distal radioulnar joint (DRUJ) instability is the most functionally disabling condition that can result from injury to the TFCC. The prime stabilizers of the DRUJ are the dorsal and palmar radioulnar ligaments and the triangular fibrocartilage. The fovea of the ulna serves as the functional and anatomic origin of the radioulnar ligaments; they then split into a 320 Journal of the American Academy of Orthopaedic Surgeons

2 dual insertion at the volar and dorsal margins of the sigmoid notch of the radius. Nakamura et al 2 demonstrated that the radioulnar ligaments arise through the Sharpey fibers vertically from a broad area at the base of the ulnar styloid (the fovea), with additional fibers attaching more distally to the ulnar styloid itself. Kleinman 3 refers to the deep fibers of the dorsal and palmar ligaments as the ligamentum subcruentum. The floor of the ECU sheath arises also through the Sharpey fibers from the dorsal side of the foveal region of the ulnar head. What was previously referred to as the ulnar collateral ligament has been revealed to consist only of loose fibers passing from the tip of the ulnar styloid to the triquetrum without Sharpey fibers. At its radial margin, the fibrocartilage disk transitions into hyaline cartilage but does not have direct fibers of insertion to bone at the distal margin of the sigmoid notch. 2 The volar and dorsal radioulnar ligaments secure the radial attachment of the TFCC at a deeper position along the volar and dorsal margins of the sigmoid notch. The term meniscal homolog has been used to denote the ulnar sling or leash of tissue that sweeps distally from the surface of the fibrocartilage disk to attach at the articular margin of either the triquetrum (90% of patients) or the triquetrum and the lunotriquetral ligament (10% of patients). 4 Biomechanics Twenty percent of the stability at the DRUJ is provided through articular contact between the ulnar head and the sigmoid notch of the radius. 5 The palmar radioulnar ligament is the major constraint to palmar translation of the distal radius relative to the ulna. Dorsal translation of the distal radius relative to the ulna is primarily constrained by the dorsal radioulnar ligament, with secondary constraint by the palmar ligament. 5 In pronation, the greatest translation of the radius relative to the stable ulna occurs after sectioning of the dorsal radioulnar ligament; in supination, the greatest translation occurs after sectioning of the palmar radioulnar ligament. 6,7 Multiple studies confirm that the dorsal radioulnar ligament tightens in pronation and that the palmar radioulnar ligament tightens in supination. 6,8,9 However, a laboratory measurement of tension within the dorsal and palmar radioulnar ligaments has no bearing on the pathologic instability patterns observed at the DRUJ following division of one or more ligaments. Under loaded conditions, the deep vertical foveal insertion of the radioulnar ligament (ligamentum subcruentum) had a greater effect on stability than did the more horizontal fibers inserting near the base of the ulnar styloid. 10 When the foveal attachment is completely avulsed, ulnar shortening is not effective in restoring stability to the DRUJ. 11 The distal portion of the interosseous membrane has been demonstrated to play a role in constraining dorsal radius translation and dislocation at the DRUJ. 12 The ECU subsheath and the volar ulnocarpal ligaments do not appear to contribute significantly to DRUJ stability. 5 Patient History and Physical Examination Mechanisms of injury that correlate with injury to the TFCC include axial loading, ulnar deviation, and forced extremes of forearm rotation. Patients usually report ulnar-sided wrist pain of a mechanical nature that is increased with wrist positions and activities that reproduce the mechanism of injury (eg, forearm rotation, ulnar deviation). They also may report localized swelling, crepitus, weakness, and a sense of instability. Physical examination often reveals focal tenderness at the relevant structures on the ulnar side Figure 1 Stress testing of the distal radioulnar joint. The examiner stabilizes the patient s ulna between thumb and forefinger with the contralateral hand and translates the radius volar and dorsal to the fixed ulna with the ipsilateral hand, holding the patient as shown. of the wrist. The surgeon should test the DRUJ by stabilizing the ulna with one hand and translating the radius to its volar and dorsal limits with the other, noting both the amplitude and the firmness of the end point compared with the contralateral side in neutral, pronation, and supination (Figure 1). Identification of the most injured structures is ideal. However, diffuse tenderness may preclude discrete distinction. Additional provocative testing includes hypersupination, application of load to the DRUJ, and the ulnocarpal stress test (axial load, ulnar deviation, and extension of the wrist, with or without the addition of forearm supination and pronation). In one study, all 45 patients with ulnar wrist pain and a positive ulnocarpal stress test were found to have relevant pathology on arthroscopy. 13 However, pathology was confirmed by magnetic resonance imaging (MRI) in only 4 of 23 patients, by bone scan in 19 of 27, and by plain radiographs in 9 of 45. Volume 16, Number 6, June

3 Management of Acute Triangular Fibrocartilage Complex Injury of the Wrist Figure 2 Magnetic resonance image of a Palmer type 1B lesion. The normal low-signal intensity of fibrocartilage tissue is disrupted by high-signal intensity near the foveal insertion of the TFCC complex (arrow). Another recently described physical examination, the fovea sign, consists of tenderness that replicates the patient s pain when pressure is applied to the region of the fovea. In a series of 272 patients treated with wrist arthroscopy, the fovea sign had a sensitivity of 95.2% and a specificity of 86.5% for lesions deemed by the arthroscopist to represent either a foveal disruption and/or ulnotriquetral ligament injury. 14 According to these authors, the foveal sign is the most specific clinical examination for injuries of the TFCC at these locations. Imaging Studies Because most ulnar-sided injuries are to the soft tissues, plain radiographs are often normal. However, they should be obtained as part of a complete acute wrist trauma evaluation. Specifically, plain radiographs are helpful in evaluating for radioulnar ligament disruption occurring via fracture. In a series of 166 distal radius fractures, 14 were found to have associated DRUJ instability. 15 All 14 had fractures of the ulnar styloid. Conversely, in a prospective study of 51 patients with distal radius fracture, 10 of 11 patients with a peripheral TFCC tear were found to have DRUJ instability. 16 Instability was not evident radiographically. MRI, with or without the injection of intra-articular contrast medium, is the primary advanced imaging method used for evaluating TFCC injuries. In a study comparing high-resolution MRI scans with standard MRI scans, accuracy rates for detection of a tear of the TFCC were found to be 79% and 76%, respectively 17 (Figure 2). Another study of observer experience found the accuracy rate of tear detection to be 69% but tear localization to be only 37%. 18 In a study in which three experienced musculoskeletal specialist radiologists evaluated unenhanced MRI images and MR arthrograms, the authors found that MRI combined with MR arthrograms for the detection of a TFCC tear had a sensitivity of 17%, specificity of 79%, and accuracy of 64%. 19 Using high-signal intensity of the ulnar insertion of the triangular fibrocartilage as the standard for diagnosing a tear, the accuracy rate was found to be only 55%. Weighted kappa values revealed only fair agreement among the three observers. One of the most recent studies of high-resolution MRI concluded that this technology does not accurately diagnose injuries of the dorsal radioulnar, palmar radioulnar, or ulnolunate ligaments. 20 Plain arthrography has largely been supplanted by MRI. Dye may be injected into the DRUJ, the radiocarpal joint, and the midcarpal joint in a chosen sequence. The radiologist then notes the passage of dye from one joint compartment to another. This indicates that communication exists between the compartments. A study of 150 patients compared findings on arthrography with findings at the time of arthroscopy. 21 Only 42% agreement was found between the two methods of assessment, with 58% of the arthrographic diagnoses changing at the time of arthroscopy. Of the 44 patients with normal arthrographic findings, 80% had injuries noted on arthroscopy. A final method of imaging ulnar-sided wrist injuries involves looking directly at them with an arthroscope from a purely diagnostic standpoint, with the expectation of rendering treatment immediately thereafter. From the radiocarpal joint, tears involving the distal surface of the triangular fibrocartilage disk itself can be easily seen and probed to identify a loose flap of tissue. This flap is likely to become trapped when the distal surface comes into contact with another joint surface, causing pain. The so-called trampoline test consists of using a probe to depress the center of the disk. The surgeon observes the tension and the ability of the disk to rebound when the probe is removed. Good tension and prompt rebound indicate that the disk is attached normally at all of its anatomic insertions. Laxity and absence of rebound indicate detachment at one or more points of insertion. The radial attachments of the radioulnar ligaments cannot be seen from the radiocarpal joint with an intact disk. Palpation with a probe for tissue tension along the volar and dorsal margins of the disk, especially while manually translating the radius on a stabilized ulna, yields indirect information regarding the integrity of the underlying radioulnar ligaments. The ulnar attachment of the radioulnar ligaments to the fovea is not visualized from the radiocarpal joint unless there is a substantial tear in the central fibrocartilage disk. Once the disk tear has been débrided, the foveal ligament insertion can be easily seen and palpated with a probe through the defect. The volar extrinsic ligaments can be seen, as well; they are palpated for normal tension or excessive laxity. Such laxity indicates injury. 322 Journal of the American Academy of Orthopaedic Surgeons

4 Figure 3 Figure 4 The Palmer classification of acute tears of the triangular fibrocartilage complex. Class 1A, central tear of the fibrocartilage disk tissue (I). Class 1B, ulnar-sided peripheral detachment (II). Class 1C, tear of the volar ulnar extrinsic ligaments (III). Class 1D, radial-sided peripheral detachment (IV). (Reproduced with permission from the Mayo Foundation.) Arthroscopic view of a Palmer class 1A tear. Typically, such tears are sagittally oriented, occurring near the radial margin of the fibrocartilage articular disk, where strain is highest. Figure 5 Arthroscopic view of a Palmer class 1B tear involving separation between the fibrocartilage articular disk and the dorsal capsule. The arrows point to the free edge of separated fibrocartilage tissue. This can be argued to be a class 1A tear. Classification Palmer and Werner classified TFCC tears into class 1 (acute traumatic tears) and class 2 (chronic degenerative tears) 1 (Figure 3). The Palmer class 1A lesion is a tear within the substance of the fibrocartilage disk, with no instability of the DRUJ (Figure 4). A simple tear usually occurs Figure 6 Arthroscopic view of a Palmer class 1C lesion demonstrating complete radiocarpal dislocation. The arrows indicate the free edge of the transverse rupture of the volar ulnar extrinsic ligaments. near the radial insertion of the disk, in the sagittal plane. More complex tears may involve the entire central portion of the disk. A strain analysis study demonstrated nonuniform strain distribution within the TFC, which was dependent on forearm position. 22 Strain was noted primarily in the radioulnar axis, accounting for the sagittal orientation of the tear. The strain was concentrated in the radial portion of the disk, which is the typical location. The Palmer class 1B lesion involves injury to the ulnar attachment of the TFCC either by ligament avulsion from the fovea or via fracture through the base of the ulnar styloid, resulting in DRUJ instability. However, this classification has been more broadly applied to injuries that do not result in DRUJ instability, most prevalently to a lesion in which the surgeon perceives that there has been a separation of the fibrocartilage disk from the dorsal capsule (Figure 5). Separation of the fibrocartilage disk from the dorsal capsule is biomechanically and clinically the same as a Palmer class 1A injury and should be classified as such. A Palmer class 1C lesion of the TFCC denotes injury to the volar ulnar extrinsic ligaments (ie, ulnolunate, ulnotriquetral, ulnocapitate). These three ligaments originate not from the distal ulna but from the palmar radioulnar ligament. Disruption of these robust ligaments is rare, requiring high-energy. Such injuries usually result in complete radiocarpal dislocation (Figure 6). Associated marginal fractures of the radius are typical. Tay et al 14 de- Volume 16, Number 6, June

5 Management of Acute Triangular Fibrocartilage Complex Injury of the Wrist Table 1 Evaluation and Management of Acute Ulnar-sided Wrist Trauma DRUJ Manual Stress Examination Focal Tenderness Examination (positive ulnocarpal stress test plus) Radiographic Examination Treatment Stable DRUJ. Check amplitude and end-point compared with contralateral side in supination, neutral, and pronation. Unstable DRUJ Tender over disk radial to ECU, or tender over ulnar sling but not tender at fovea precisely Tender specifically at fovea (ie, positive fovea sign ) No fracture of radius near the sigmoid notch No fracture of ulna near fovea Distal tip of ulnar styloid may or may not have a small fracture fragment No fracture of ulna near fovea Unstable DRUJ Tender at ulnar styloid Displaced fracture of ulnar styloid involving its base and containing the foveal region Unstable DRUJ Tender radially over disk and margin of sigmoid notch DRUJ = distal radioulnar joint, ECU = extensor carpi ulnaris Displaced fracture of distal radius involving the margin of the sigmoid notch Initial: corticosteroid injection of ulnocarpal joint up to 2 times at 3-week intervals Final: arthroscopic débridement of loose fibrocartilage tissue fragments that prove mechanically unstable to direct probe manipulation Supplemental: ulnar shortening osteotomy if preexisting ulnocarpal impaction Open repair of purely ligamentous avulsion of ulnar attachment of radioulnar ligaments, arthroscopic repair, or immobilization of the DRUJ in supination. Palmaris longus tendon graft augmentation may be required with late presentation (after 6 weeks) Tension band wiring of styloid fragment. Make sure that radioulnar ligaments actually attach to styloid fragment Open or arthroscopic reduction and fixation of displaced sigmoid notch marginal fragments with Kirschner wire or screw scribed a new lesion of the ulnar volar extrinsic ligaments, the triangular fibrocartilage split tear. This consists of a disruption parallel to the orientation of the ligament fibers and their tension under load. The Palmer class 1D lesion denotes radial-sided detachment of the TFCC. This typically occurs via fracture at the margin of the sigmoid notch coincident to the insertion of one or both of the radioulnar ligament bundles. Treatment Acute surgical treatment is needed for unstable and displaced fractures as well as for a clearly unstable DRUJ (Table 1). Absent these findings, initial management of TFCC injury is nonsurgical. Standard nonsurgical treatments include temporary splint immobilization of the wrist and forearm, oral nonsteroidal antiinflammatory medication, corticosteroid joint injection, and physical therapy. When the DRUJ proves unstable on physical examination and the patient chooses nonsurgical treatment, the forearm should be casted in supination for at least 4 weeks. The wrist alone should be immobilized for an additional 2 weeks before initiating therapy. Arthroscopic Débridement of Fibrocartilage Disk Tissue The Palmer class 1A tear typically creates an unstable flap of tissue that can be demonstrated by manipulation with a probe 22 (Figure 4). A cleft separating the central fibrocartilage from the dorsal capsule or detachment of the distal margin of the meniscal homolog also may be identified 4 (Figure 5). The surgeon should remove the portion of the fibrocartilage tissue that is unstable when probed and likely to catch against other joint surfaces. The essentials of wrist arthroscopy for acute trauma have been well-documented elsewhere. 23 The class 1A lesion is best viewed from the dorsal 3,4 portal. Débridement of the disk is done via the 6R portal. Torn fibrocartilage tissue responds poorly to the motorized shaver, and a radiofrequency ablation probe is a 324 Journal of the American Academy of Orthopaedic Surgeons

6 more useful tool for efficient removal of the torn fragments. 23 Resection is continued until a mechanically stable and smooth residual rim remains. Up to 80% of the substance can be resected without creating iatrogenic instability 5,22 (Figure 7). Viewed through the central defect using the 3,4 portal, the foveal insertion fibers of the radioulnar ligaments can be seen and probed to confirm integrity (ie, rule out a class 1B tear). By switching portals, the radial insertions of the radioulnar ligaments can be seen and probed to confirm integrity (ie, rule out a class 1D tear). Manually stressing the DRUJ while making these assessments further supports the confirmation of a stable joint, with the injury confined to the fibrocartilage disk itself. In a series of 28 patients treated with arthroscopic disk débridement, there were 13 excellent, 8 good, 2 fair, and 5 poor results. 24 In a similar series, good to excellent results were achieved in 68% of patients. 25 Arthroscopic Repair of the TFCC Sagerman and Short 26 described arthroscopic repair of radial-sided detachments using double-armed long meniscal repair sutures. These were drilled intra-articularly via an ulnar approach, through the TFCC tissue, then through the radius to exit the radial cortex, establishing a horizontal mattress pattern of repair. In a study evaluating inside-out arthroscopic repair in 37 patients, 10 excellent, 24 good, and 3 fair results were reported based on the Mayo modified wrist score. 27 A similar series of 20 patients yielded 7 excellent, 7 good, 4 fair, and 2 poor results according to the Mayo modified wrist score. Patients recovered 90% of contralateral motion and 83% of contralateral grip strength at a minimum 2-year follow-up. 28 An average Disabilities of the Arm, Shoulder and Hand (DASH) score of 12 was obtained from 35 patients undergoing arthroscopic repair of peripheral TFCC tears. Significant correlations were noted between worsened outcomes and advancing age as well as postoperative ulnar positive variance. 29 Similar results appear possible in association with arthroscopic management of distal radius fractures. In one study, 13 patients achieved an average DASH score of 13 and average grip strength equivalent to 78% of the contralateral side. 30 This technique involves repairing the peripheral TFCC rim to the adjacent floor of the ECU tendon sheath. Tay et al 14 advocate arthroscopic suture plication of the lesion described parallel to the fibers of the volar ulnar extrinsic ligaments. Arthroscopic repair is indicated when the dorsal radioulnar ligament is detached via a triangular fracture fragment of the lunate fossa and sigmoid notch. This is a common finding in the setting of AO type C distal radius fractures. 24 Using the 3,4 portal for the scope, the 4,5 portal is established to access the triangular fracture fragment and the attached dorsal radioulnar ligament. The fracture interface is prepared with a micro curet (Figure 8, A). The dorsal ulnar corner fragment is reduced and held compressed through a small extension of the 4,5 portal wound (Figure 8, B). A guidewire is followed by the cannulated drills and, finally, the headless compression screw (Figure 8, C). Figure 7 Mechanically unstable tears of the fibrocartilage articular disk are débrided until a stable peripheral rim can be verified by probe testing. This image demonstrates a Palmer class 1A lesion. Open Repair of the TFCC Thirty-three patients without DRUJ instability underwent open repair of peripheral rim injuries. 31 The authors reported 11 excellent, 15 good, and 6 fair results and 1 poor result based on the Mayo modified wrist score. In another study, acute injuries of the DRUJ and TFCC were repaired in 130 patients. 32 The author performed closed reduction and wire transfixion of the radius to the ulna in 86 patients, internal fixation of the ulnar styloid with pinning in 19 patients, internal fixation of the ulnar styloid alone in 13 patients, and fixation of radial-sided fractures in 12 patients. Outcomes were excellent in 95 patients, fair in 30, and poor in 5. With a Palmer class 1C lesion, if the marginal radius fragments carry the ligament attachments, sufficient stability may be achieved by fixation of these fragments alone. In the rare instance of a pure dislocation, radiocarpal pinning with a inch Kirschner wire (K-wire) for 4 weeks allows the ligaments to heal at the correct length. Open repair usually is needed for ulnar detachment of the radioulnar ligaments. The incision is made in the shape of an inverted L, with the longitudinal limb along the volar margin of the ECU sheath and the transverse limb in the distalvolar wrist crease. The skin flap is tacked back to expose the dorsalulnar sensory nerve passing obliquely through the field. The main branch typically passes the midaxial plane of the limb just at the level of the tip of the ulnar styloid. Particular attention should be given to a small transverse branch that diverges as proximal as the ulnar neck. Volume 16, Number 6, June

7 Management of Acute Triangular Fibrocartilage Complex Injury of the Wrist Figure 8 Arthroscopic repair of the dorsal radioulnar ligament. A, The fracture interface of the dorsal ulnar corner of the sigmoid notch is prepared for reduction by removing clot with an arthroscopic micro curet. B, The fracture interface is held compressed by arthroscopic small bone instruments while definitive fixation is placed. C, Anteroposterior radiograph demonstrating a secure headless compression screw inserted percutaneously. This allows immediate motion rehabilitation of a sigmoid notch marginal fracture. The next layer encountered is the retinacular sheath, which is in continuity with the antebrachial fascia. The sheath should be divided longitudinally but volar to the anchor of the ECU sheath. The ulnar styloid is exposed, and the fovea is easily accessed through the loose tissue volar to the styloid base. With soft-tissue avulsion injury of the radioulnar ligament from the fovea, direct reinsertion is possible with either a bone anchor drilled into the fovea and then sewn through the detached fibers or with sutures passed from the detached fibers through transosseous drill holes that will be tied over the ulnar cortex. In a patient with delayed presentation (approximately 6 weeks) following acute ulnoradial ligament disruption, the ligament fibers may have retracted and degenerated sufficiently to make direct repair alone inadequate. Free tendon graft augmentation can enhance the repair strength. 33 Free tendon grafts have been described in the context of chronic instability reconstruction. 34,35 The author uses a palmaris longus free graft placed through a drill hole in the fovea of the ulna; the graft is then passed through two drill tunnels in the radius. 33 The fibrocartilage disk is retracted distally. Working underneath the disk, through the DRUJ, and volar to the styloid, the surgeon makes two drill holes from the volar and dorsal distal margins of the sigmoid notch across to the radial cortex near the insertion of the brachioradialis, where the two tails of the palmaris graft are retrieved and tied to each other over a bone bridge 33 (Figure 9). Early repairs and delayed cases with augmentation should be supported by double inch K-wire ulna-to-radius transfixion (four cortices) in neutral for at least 4 weeks. The alternative pattern of injury is fracture through the base of the ulnar styloid. The surgeon should check to be sure that the radioulnar ligament origin is attached to the styloid fragment. Tension band wiring of the styloid fragment back to its original location is accomplished with a single inch K-wire and a figure-of-8 looped 23 G wire passed through a transverse drill hole in the ulnar cortex (Figure 10). This fixation is strong enough to withstand immediate rehabilitation. Ulnar Shortening Osteotomy Patients who present to the surgeon s office following acute wrist trauma may ultimately undergo surgery when the arthroscopic findings indicate that the pattern is chronic and degenerative rather than acute. Many of these patients will have ulnar positive variance, and some will have the other stigmata of ulnocarpal impaction (ie, Palmer class 2 lesions), such as cysts in the proximal ulnar lunate or distal ulnar head. 1 The patients may or may not have had any wrist pain before the acute injury. The reported failure rate following arthroscopic débridement of the disk tear alone is not encouraging. In a series of 16 patients treated with arthroscopic débridement alone, excellent results were achieved in all 11 acute traumatic tears, whereas the 5 patients with degenerative tears all had poor results. 36 In another series, 13 of 97 patients failed to achieve relief following arthroscopic disk débridement alone. They were then treated with 326 Journal of the American Academy of Orthopaedic Surgeons

8 Figure 9 Figure 10 Palmaris longus free graft. Access to the fovea is gained volar to the extensor carpi radialis and the styloid. Working underneath a distally retracted fibrocartilage disk, two intra-articular drill tunnels are made from the volar and dorsal articular margins of the sigmoid notch across to the radial cortex of the radius near the insertion of the brachioradialis. Suture passers capture the two ends of the palmaris longus graft that has been passed through the ulnar fovea drill tunnel. The graft ends are brought through to the radial cortex, where they are secured to each other over a bone bridge. diaphyseal ulnar shortening osteotomy of 2 mm, after which 12 of 13 achieved complete pain relief 37 (Figure 11). Four complications related to the osteotomy were reported, including nonunion requiring bone graft. Twelve patients with ulnar positive variance with acute TFCC injuries underwent simultaneous arthroscopic distal ulnar head shortening osteotomy (ie, Feldon wafer method) at the time of initial fibrocartilage débridement. 38 Postoperatively, none had pain during the ulnocarpal stress (Figure 12). In another series, 25 patients underwent 3-mm transverse diaphyseal osteotomies with plate fixation at the time of arthroscopy based on preoperative identification of ulnar positive variance. Two treatment failures and three Open repair of fracture through the base of the ulnar styloid. A, The ulnar styloid fragment is manually reduced at the fracture line and held compressed while alignment is secured with a single inch K-wire. Compression is then increased with a figure-of-8 23-G tension band wire. B, Radiograph demonstrating secure tension band wiring of a fracture through the ulnar fovea region. External immobilization is not required with this method, and active forearm rotation may be started immediately postoperatively. complications were reported. 39 Not every patient with a disk tear who is ulnar positive requires simultaneous ulnar shortening osteotomy. A careful evaluation should be done at the time of treatment for patients who are not only ulnar positive but who also have findings of preexisting ulnocarpal impaction, whether symptomatic or asymptomatic. Consideration should be given to performing simultaneous ulnar shortening osteotomy. When choosing between a diaphyseal and a distal wafer ulnar shortening osteotomy, the surgeon may wish to consider the total amount of shortening intended and the conformation of the DRUJ. A resection wafer can provide only 2 to 3 mm of shortening. Excessive resection concentrates the surface area for articular loading at the DRUJ. When the conformation of the DRUJ is oriented in a distal-radial to proximalulnar slope, diaphyseal shortening will increase joint loading. Current evidence indicates that the distal wafer procedure, whether arthroscopic or open, provides equivalent relief to a diaphyseal shortening osteotomy with plate and screws; however, the latter has a higher complication rate, including delayed union, nonunion, and the need for hardware removal. 40,41 Summary The TFCC is composed of functionally related but distinct anatomic structures at the ulnar side of the wrist. Acute injuries to the structures may involve one or more components. The clinician evaluating patients with ulnar wrist pain must attempt to define which components are involved. The Palmer classification system remains useful, but it does not clarify the most critical issue the presence or absence of DRUJ instability. In particular, the term class 1B Volume 16, Number 6, June

9 Management of Acute Triangular Fibrocartilage Complex Injury of the Wrist Figure 11 Radiograph demonstrating stabilization of the ulnar shaft with a smallfragment compression plate. injury is now being used to describe two distinct entities: a lesion that is perfectly stable at the DRUJ (ie, central fibrocartilage disk separation from the dorsal wrist capsule) and a lesion that produces DRUJ instability (ie, radioulnar ligament avulsion from the ulnar fovea). Much confusion has ensued in both the evaluation and management of class 1B injuries. Anatomic studies have shown that a true class 1D injury can occur only through bone, which should be fixed in the presence of an unstable DRUJ. 2 Many injuries of the fibrocartilage disk only (ie, no involvement of the radioulnar ligament) near the radial side that have been labeled as class 1D are really class 1A injuries that have occurred exactly where the biomechanical studies predict that they should. 22 The true Palmer class 1C injury is exceedingly rare. To be classified as such, the injury must involve radiocarpal joint instability caused by high-energy trauma. Class Figure 12 Radiograph of a patient treated with arthroscopic distal ulna resection. In this technique, the portion of the head that impacts the proximal ulnar corner of the lunate is removed without disturbing the fibers of the dorsal and volar radioulnar ligaments that insert at the fovea. This insertion is further radial in location than is often appreciated. 1C injuries are not caused by lowenergy mechanisms of injury. MRI yields a static image of varying signal intensities that is capable of demonstrating tissue discontinuity. Ligament stability is not diagnosed by a static image but rather by direct assessment of dynamic instability during physical examination preoperatively and intraoperatively. Management of an acute ulnar wrist injury begins with defining the specific anatomic structures that have been disrupted and the degree to which they have been disrupted. Treatment strategy is then matched to the specific injury (Table 1). References Evidence-based Medicine: Most of the references include cadaver anatomy dissection, cadaver biomechanics, and level IV clinical series. Citation numbers printed in bold type indicate references published within the past 5 years. 1. Palmer AK: Triangular fibrocartilage complex lesions: A classification. J Hand Surg [Am] 1989;14: Nakamura T, Takayama S, Horiuchi Y, Yabe Y: Origins and insertions of the triangular fibrocartilage complex: A histological study. J Hand Surg [Br] 2001;26: Kleinman WB: Stability of the distal radioulna joint: Biomechanics, pathophysiology, physeal diagnoses, and restoration of function: What we have learned in 25 years. J Hand Surg [Am] 2007;32: Nishikawa S, Toh S: Anatomical study of the carpal attachment of the triangular fibrocartilage complex. J Bone Joint Surg Br 2002;84: Stuart PR, Berger RA, Linscheid RL, An KN: The dorsopalmar stability of the distal radioulnar joint. J Hand Surg [Am] 2000;25: Ward LD, Ambrose CG, Masson MV, Levaro F: The role of the distal radioulnar ligaments, interosseous membrane, and joint capsule in distal radioulnar joint stability. J Hand Surg [Am] 2000;25: Kihara H, Short WH, Werner FW, Fortino MD, Palmar AK: The stabilizing mechanism of the distal radioulnar joint during pronation and supination. J Hand Surg [Am] 1995;20: DiTano O, Trumble TE, Tencer AF: Biomechanical function of the distal radioulnar and ulnocarpal wrist ligaments. J Hand Surg [Am] 2003;28: Schuind F, An KN, Berglund L, et al: The distal radioulnar ligaments: A biomechanical study. J Hand Surg [Am] 1991;16: Haugstvedt JR, Berger RA, Nakamura T, Neale P, Berglund L, An KN: Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint. J Hand Surg [Am] 2006;31: Nishiwaki M, Nakamura T, Nakao Y, Nagura T, Toyama Y: Ulnar shortening effect on distal radioulnar joint stability: A biomechanical study. J Hand Surg [Am] 2005;30: Watanabe H, Berger RA, Berglund LJ, Zobitz ME, An KN: Contribution of the interosseous membrane to distal radioulnar joint constraint. J Hand Surg [Am] 2005;30: Nakamura R, Horii E, Imaeda T, Nakao E, Kato H, Watanabe K: The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain. J Hand Surg 328 Journal of the American Academy of Orthopaedic Surgeons

10 [Br] 1997;22: Tay SC, Tomita K, Berger RA: The ulnar fovea sign for defining ulnar wrist pain: An analysis of sensitivity and specificity. J Hand Surg [Am] 2007;32: May MM, Lawton JN, Blazar PE: Ulnar styloid fractures associated with distal radius fractures: Incidence and implications for distal radioulnar joint instability. J Hand Surg [Am] 2002;27: Lindau T, Adlercreutz C, Aspenberg P: Peripheral tears of the triangular fibrocartilage complex cause distal radioulnar joint instability after distal radial fractures. J Hand Surg [Am] 2000;25: Kato H, Nakamura R, Shionoya K, Makino N, Imaeda T: Does highresolution MR imaging have better accuracy than standard MR imaging for evaluation of the triangular fibrocartilage complex? J Hand Surg [Br] 2000;25: Blazar PE, Chan PS, Kneeland JB, Leatherwood D, Bozentka DJ, Kowalchick R: The effect of observer experience on magnetic resonance imaging interpretation and localization of triangular fibrocartilage complex lesions. J Hand Surg [Am] 2001;26: Haims AH, Schweitzer ME, Morrison WB, et al: Limitations of MR imaging in the diagnosis of peripheral tears of the triangular fibrocartilage of the wrist. AJR Am J Roentgenol 2002; 178: Tanaka T, Yoshioka H, Ueno T, Shindo M, Ochiai N: Comparison between high-resolution MRI with a microscopy coil and arthroscopy in triangular fibrocartilage complex injury. J Hand Surg [Am] 2006;31: Chung KC, Zimmerman NB, Travis MT: Wrist arthrography versus arthroscopy: A comparative study of 150 cases. J Hand Surg [Am] 1996;21: Adams BD, Holley KA: Strains in the articular disk of the triangular fibrocartilage complex: A biomechanical study. J Hand Surg [Am] 1993;18: Smith DW, Henry MH: Comprehensive management of associated soft tissue injuries in distal radius fractures. Journal of the American Society for Surgery of the Hand 2002; 2: Westkaemper JG, Mitsionis G, Giannakopoulos PN, Sotereanos DG: Wrist arthroscopy for the treatment of ligament and triangular fibrocartilage complex injuries. Arthroscopy 1998; 14: Blackwell RE, Jemison DM, Foy BD: The holmium:yttrium-aluminumgarnet laser in wrist arthroscopy: A five-year experience in the treatment of central triangular fibrocartilage complex tears by partial excision. J Hand Surg [Am] 2001;26: Sagerman SD, Short W: Arthroscopic repair of radial-sided triangular fibrocartilage complex tears. Arthroscopy 1996;12: Shih JT, Lee HM, Tan CM: Early isolated triangular fibrocartilage complex tears: Management by arthroscopic repair. J Trauma 2002;53: Haugstvedt JR, Husby T: Results of repair of peripheral tears in the triangular fibrocartilage complex using an arthroscopic suture technique. Scand J Plast Reconstr Surg Hand Surg 1999; 33: Ruch DS, Papadonikolakis A: Arthroscopically assisted repair of peripheral triangular fibrocartilage complex tears: Factors affecting outcome. Arthroscopy 2005;21: Ruch DS, Yand CC, Smith BP: Results of acute arthroscopically repaired triangular fibrocartilage complex injuries associated with intra-articular distal radius fractures. Arthroscopy 2003;19: Cooney WP, Linscheid RL, Dobyns JH: Triangular fibrocartilage tears. JHandSurgAm1994;19: Mikic ZD: Treatment of acute injuries of the triangular fibrocartilage complex associated with distal radioulnar joint instability. J Hand Surg Am 1995;20: Martineau PA, Bergeron S, Beckman L, Steffen T, Harvey EJ: Reconstructive procedure for unstable radialsided triangular fibrocartilage complex avulsions. J Hand Surg [Am] 2005;30: Adams BD, Berger RA: An anatomic reconstruction of the distal radioulnar ligaments for posttraumatic distal radioulnar joint instability. J Hand Surg [Am] 2002;27: Henry MH, Smith DW, Masson MV: Reconstruction of distal radio-ulnar joint instability. Journal of the American Society for Surgery of the Hand 2004;4: Minami A, Ishikawa J, Suenaga N, Kasashima T: Clinical results of treatment of triangular fibrocartilage complex tears by arthroscopic debridement. J Hand Surg Am 1996;21: Hulsizer D, Weiss AP, Akelman E: Ulna-shortening osteotomy after failed arthroscopic debridement of the triangular fibrocartilage complex. J Hand Surg [Am] 1997;22: Tomaino MM, Weiser RW: Combined arthroscopic TFCC debridement and wafer resection of the distal ulna in wrists with triangular fibrocartilage complex tears and positive ulnar variance. J Hand Surg [Am] 2001; 26: Minami A, Kato H: Ulnar shortening for triangular fibrocartilage complex tears associated with ulnar positive variance. J Hand Surg [Am] 1998;23: Bernstein MA, Nagle DJ, Martinez A, Stogin JM, Wiedrich TA: A comparison of combined arthroscopic triangular fibrocartilage complex debridement and arthroscopic wafer distal ulna resection versus arthroscopic triangular fibrocartilage complex debridement and ulnar shortening osteotomy for ulnocarpal abutment syndrome. Arthroscopy 2004;20: Constantine KJ, Tomaino MM, Herndon JH, Sotereanos DG: Comparison of ulnar shortening osteotomy and the wafer resection procedure as treatment for ulnar impaction syndrome. J Hand Surg [Am] 2000;25: Volume 16, Number 6, June