Journal of the American Academy of Orthopaedic Surgeons 170 The earliest known report of a lunotriquetral (LT) ligament injury was made by Hessert, who de- scribed three patients with LT joint dislocations in 1903. Ten years later, Chaput and Vaillant pub- lished a classic example of a volar intercalated segmental instability (VISI) deformity in a radiographic study of carpal injuries. Also in 1913, von Mayersbach noted a carpal dissociation in a 72-year-old man, reporting that the cuneiform bone (i.e., triquetrum) was separated from the semilunar bone (i.e., lu- nate) but was not substantially changed in position. Other authors described similar carpal deformi- ties, but it was not until 1984 that Reagan et al 1 first described the role of the LT ligament in the develop- ment of the VISI pattern. In 1972, Linscheid et al 2 pub- lished an article that described the volar instability pattern but did not elucidate its etiology. They applied the concept of intercalated segmen- tal instability to the carpus, utiliz- ing the lunate position in either flexion or extension to identify the volar and dorsal patterns, respec- tively. The role of the scapholunate ligament in the pathomechanics of the dorsal intercalated segmental instability (DISI) deformity was well recognized, but the role of the LT ligament in some VISI deformi- ties had not yet been elucidated. Such deformities were initially attributed to traumatic or congeni- tal laxity of the palmar radiocarpal ligaments. Since the 1984 report by Reagan et al, 1 other authors have further defined the role of LT ligament injury in VISI deformities. 3-7 Al- though LT ligament dissociation with attenuation of secondary liga- mentous restraints results in a VISI deformity, not all VISI deformities can be attributed to LT ligament injury. Some appear to have a final common pathway but multiple mechanisms, all of which depend on LT ligament attenuation. In describing injuries of the LT ligament, distinguishing between dynamic and static instability is imperative. Injuries with a normal appearance on conventional radio- graphs and dynamic instability that are present only under load or in certain positions are classified as LT tears. Fixed carpal collapse (VISI) on conventional radiographs repre- sents static instability and is classi- fied as LT ligament dissociation. Dr. Shin is Director, Division of Hand and Microvascular Surgery, Department of Orthopaedic Surgery, Naval Medical Center, San Diego, Calif. Dr. Battaglia is Staff Surgeon, Department of Orthopaedic Surgery, Naval Hospital, Naples, Italy. Dr. Bishop is Professor and Chairman, Division of Hand and Microvascular Surgery, Department of Orthopaedic Surgery, Mayo Clinic, Rochester, Minn. The Chief, Bureau of Medicine and Surgery, Navy Department, Washington, DC, Clinical Investigation Program, sponsored this report #84-16-1968-788 as required by HSETCINST 6000.41A. The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, the Department of Defense, or the United States Government. Reprint requests: Dr. Bishop, Mayo Clinic E14A, 200 First Street Southwest, Rochester, MN 55905. Abstract Isolated injury of the lunotriquetral interosseous ligament complex and associ- ated structures is less common and is poorly understood compared with the other proximal-row ligament injury, scapholunate dissociation. The spectrum of injuries ranges from isolated partial tears to frank dislocation, and from dynamic to static carpal instability. The diagnosis may be difficult to establish because of the many possible causes of ulnar-sided wrist pain and the often nor- mal radiographic appearance. The mechanism of injury is variable and includes attrition by age, positive ulnar variance, and perilunate or reverse perilunate injury. Appropriate treatment requires assessment of the degree of instability and the chronicity of the injury. Options include corticosteroid injection, immobilization, ligament repair, ligament reconstruction with tendon grafts, limited intercarpal arthrodesis, and ulnar shortening. J Am Acad Orthop Surg 2000;8:170-179 Lunotriquetral Instability: Diagnosis and Treatment Alexander Y. Shin, MD, CDR, USNR, Michael J. Battaglia, MD, LCDR, USN, and Allen T. Bishop, MD Alexander Y. Shin, MD, CDR, USNR, et al Vol 8, No 3, May/June 2000 171 Anatomy The scapholunate and LT ligaments are arguably the most important intrinsic ligaments of the carpus. The scapholunate and LT interos- seous ligaments are both C-shaped, spanning the dorsal, proximal, and palmar edges of the joint surfaces. Microscopically, they have similar organization, being true ligaments in the dorsal and palmar subre- gions and becoming membranous in the proximal fibrocartilaginous subregion. In an elegant study of the anatomy and histology of the scapholunate ligament, Berger 8 demonstrated that its dorsal region is thickest and strongest when tested to failure and is biomechanically the most important region. In a similar study of the properties of the LT ligament, Ritt et al 4 demon- strated that the palmar region is the thickest and strongest. These find- ings support the Òbalanced lunateÓ concept, which holds that the lu- nate is torque-suspended between the scaphoid and the triquetrum, exerting a flexion moment through the scapholunate ligament and an extension moment through the LT ligament. The dorsal LT ligament region is most important as a rota- tional constraint, whereas the pal- mar region of the LT ligament is the strongest and transmits the exten- sion moment of the triquetrum as it engages the hamate. The membra- nous proximal portion of the LT lig- ament complex is of little signifi- cance with respect to constraining rotation, translation, or distraction. Mechanism of Injury The exact mechanism of LT liga- ment injury remains controversial; it is likely that more than one mechanism plays a role. For exam- ple, perilunar dislocations occur when a force is applied to the thenar area with the wrist posi- tioned in dorsiflexion and ulnar deviation. 9,10 This injury pattern has been well described and results in a progressive injury pattern in a radial to ulnar direction, following either an osseous or a purely liga- mentous path about the lunate. Injury to the LT support structures occurs in Mayfield stage III perilu- nate injury, after either scapholu- nate injury or scaphoid fracture. These injuries will usually result in a DISI deformity, unless the scapho- lunate portion heals either sponta- neously or after intervention, in which case the ulnar-sided LT dis- order will predominate. Some of the existing case reports of LT liga- ment sprains do indeed demon- strate evidence of previous perilu- nar injury (Fig. 1). An isolated LT ligament tear may be the result of a reverse peri- lunate injury originating on the ulnar side of the wrist. 1 A recent biomechanical study has confirmed this mechanism, 11 which occurs by a fall on the outstretched hand positioned in pronation, extension, and radial deviation. The resultant intercarpal pronation overloads the ulnar-volar ligament structures and causes LT ligament injury without scapholunate disruption. Weber 12 has postulated that isolated LT lig- ament tears may occur with the wrist palmar-flexed. The dorsally applied force allows the interos- seous fibers of the LT ligament to fail, sparing the palmar radioluno- triquetral ligaments. The integrity of this ligament tethers the palmar pole of the lunate, creating an axis for palmar flexion. In patients with no history of trauma, LT instability Figure 1 Images of a 48-year-old man with chronic ulnar-sided left wrist pain. A, Posteroanterior radiograph shows normal GilulaÕs arcs 1, 2, and 3. Arcs 1 and 2 are formed by the proximal and distal joint surfaces of the proximal carpal row. Arc 3 is formed by the proximal joint surface of the distal carpal row. Midcarpal arthroscopy revealed wide gaping of the scapholunate interval (B) and LT interval (C), as well as incongruity of the LT articulation, consistent with a chronic perilunate injury. In this case, the scapholunate instability was asymp- tomatic, and the LT disorder predominated. A B C Lunate Scaphoid Triquetrum Lunate Lunotriquetral Instability Journal of the American Academy of Orthopaedic Surgeons 172 may be the result of degenerative LT lesions or inflammatory arthritis. 13 Positive ulnar variance may facili- tate LT ligament degeneration by means of a wear mechanism or alter- ation of intercarpal kinematics. 14 Pathomechanics In an uninjured wrist, the scaphoid imparts a flexion moment to the proximal carpal row, while the tri- quetrum imparts an extension moment. These opposing moments are balanced by the ligamentous attachment to the lunate. With loss of the integrity of the scapholunate ligament, the scaphoid tends to flex, while the lunate and tri- quetrum tend to extend, imparting a DISI orientation. Conversely, with loss of the integrity of the LT ligament, the triquetrum tends to extend, while the scaphoid and lunate attempt to flex. However, a complete LT ligament tear is not sufficient to cause a static carpal collapse into a VISI orientation. Sectioning of the volar and dorsal subregions of the LT ligament results in slight divergence of the triquetrum and lunate at extremes of wrist flexion and radial deviation but not collapse, unless consider- able compressive force is applied. 1 Additional tear or attenuation of secondary restraints is necessary to create static carpal instability. Both palmar and dorsal carpal lig- aments may play roles as secondary restraints. Two recent anatomic studies have implicated palmar liga- ment injury in the development of VISI in LT dissociation. Trumble et al 6 created carpal collapse with divi- sion of the ulnar arcuate ligament. Horii et al 5 demonstrated that sec- tioning of the dorsal radiotriquetral (dorsal radiocarpal) and dorsal scaphotriquetral (dorsal intercarpal) ligaments also produced static VISI following LT ligament injury. Loss of dorsal ligament integrity allows the lunate to flex more easily, in part by shifting the point of capitate con- tact palmar to the lunate axis of rota- tion (Fig. 2). Clinical Presentation and Examination The spectrum of LT ligament injury ranges from partial tears with vari- able pain and weakness to com- plete dissociation with static col- lapse, causing a forklike deformity of the wrist and prominence of the distal ulna. However, some patients with radiographic evidence of per- sistent LT malalignment after perilu- nate dislocation experience minimal symptoms and will have a satisfac- tory outcome. Symptomatic sprains invariably present with ulnar wrist pain. 1 Symptoms are usually inter- mittent and are especially prominent with wrist deviation or pronation- supination. They include dimin- ished motion, weakness, a sensation of instability or giving way, and ulnar nerve paresthesias. A painful wrist clunk with deviation is often present. 1 A history of a specific injury is usually present, 1 which may allow determination of the mechanism of injury. A history of a fall on the dor- siflexed wrist with a hypothenar contact point should increase the suspicion of ulnar-sided instabil- ity. 15 Injuries that are often classi- fied as annoying sprains may be unrecognized LT ligament injuries. A careful examination of the wrist is needed in the evaluation of ulnar-sided wrist pain to differenti- ate LT injury from other lesions. A variety of lesions may cause ulnar wrist symptoms (Table 1). 16,17 Examination should encompass the entire ulnar side of the wrist. Ulnar deviation with pronation and axial compression will elicit dynamic instability with a painful snap if a nondissociative midcarpal joint or LT ligament injury is pres- ent. Palpation will always demon- strate point tenderness at the LT joint. 1 A palpable wrist click with radioulnar deviation may be signif- icant if it occurs with pain. Pro- vocative tests that demonstrate LT laxity, crepitus, and pain are help- ful in accurately localizing the site of pathologic change. Ballottement of the triquetrum, as described by Reagan et al, 1 is per- formed by grasping the pisotrique- Figure 2 A, The dorsal extrinsic ligaments of the wrist include the dorsal radiotriquetral ligament (DRT) and the dorsal scaphotriquetral ligament (DST). B, The normal integrity of the dorsal ligaments prevents volar flexing of the lunate (shown at left). Loss of dorsal lig- ament integrity allows the lunate to flex more easily, in part by shifting the point of capi- tate contact palmar to the lunate axis of rotation (shown at right). (Reproduced from Shin AY, Bishop AT: Treatment options for lunotriquetral dissociation. Techniques Hand Upper Extremity Surg 1998;2:2-17. By permission of Mayo Foundation.) A B DST DRT Alexander Y. Shin, MD, CDR, USNR, et al Vol 8, No 3, May/June 2000 173 tral unit between the thumb and index finger of one hand and the lunate between the thumb and index finger of the other (Fig. 3, A and B). If the test is positive, pain and increased anteroposterior laxity will be noted during manipulation of the joint. The shear test is per- formed with the subjectÕs forearm in neutral rotation and the elbow on the examination table. The examin- erÕs contralateral fingers are placed over the dorsum of the lunate. With the lunate supported, the examin- erÕs ipsilateral thumb loads the pisotriquetral joint from the palmar aspect, creating a shear force at the LT joint (Fig. 3, C). Pressure on the triquetrum in the Òulnar snuffboxÓ creates a radially directed compres- sive force against the triquetrum (Fig. 3, D). Pain elicited with this maneuver may be of LT origin, but may also arise from abnormalities of the triquetrohamate joint or triangu- lar fibrocartilage complex. 15 These tests are considered positive when pain, crepitus, and abnormal mobil- ity of the LT joint are demonstrable. Comparison with the contralateral wrist is essential to elicit subtle dif- ferences. Other findings on physical examination commonly include decreased range of motion and diminished grip strength. Crepitus may be palpable with wrist devia- tion. A nondissociative instability pattern secondary to midcarpal lax- ity at the triquetrohamate joint should be ruled out, as symptoms may be very similar. The possibili- ty of injury at both levels should be considered. 18,19 Diagnostic Studies Imaging modalities useful in the evaluation of LT injuries include routine wrist radiography, motion studies, tomography, arthrography, videofluoroscopy, scintigraphy, and magnetic resonance imaging. Ap- propriate study selection is based on patient presentation (Fig. 4). The radiographic appearance of wrists with LT ligament tears is often normal (Fig. 1). Lunotrique- tral dissociation will result in dis- ruption of the smooth arcs that are formed by the proximal and distal joint surfaces of the proximal car- pal row (GilulaÕs arcs 1 and 2) and the proximal joint surfaces of the distal carpal row (GilulaÕs arc 3). Table 1 Lesions Causing Ulnar-sided Wrist Pain Distal radioulnar joint subluxation or arthrosis Ulnar-head chondromalacia Triangular fibrocartilage injury Triquetrohamate instability Hamate fractures Ulnar styloid impingement syndrome Pisotriquetral arthritis Extensor carpi ulnaris tendon subluxation Periarticular calcification Ulnar neurovascular syndromes A B C D Figure 3 A and B, The ballottement test is performed by securing the pisotriquetral unit with the thumb and index finger of one hand and the lunate with the other hand. Anterior and posterior stresses are placed on the LT joint. The criteria for a positive test are increased laxity and accompanying pain. C, In the shear test, the pisotriquetral joint is loaded by placing a palmar-to-dorsal stress across the LT joint. The lunate is supported by the examinerÕs ipsilateral fingers while the contralateral thumb loads the pisotriquetral joint. Pain with translation represents a positive test. D, Compression of the triquetrum from the ulnar snuffbox applies a radially directed force against the LT joint. Pain may indicate a disorder of the LT or triquetrohamate joint. Lunotriquetral Instability Journal of the American Academy of Orthopaedic Surgeons 174 The LT dissociation results in prox- imal translation of the triquetrum and/or LT overlap (Fig. 5). 1,20 Un- like scapholunate injuries, no LT gap occurs. Provocative radiographic views, including radial or ulnar deviation and clenched-fist anteroposterior views, are often helpful. In LT dis- sociation, the normal reciprocal motion of the scaphoid, the lunate, and the distal row is accentuated in deviation while triquetral motion is diminished. 15 This increased pal- mar flexion of the scaphoid and lunate in radial deviation without change of the triquetrum is a mani- festation of loss of the proximal- row integrity present in the normal wrist. 1 Careful evaluation of the lunate and triquetrum on lateral radio- graphs may reveal malalignment in the absence of frank carpal col- lapse. The perimeters of the tri- quetrum and lunate may be traced and their relationship assessed. 1 The longitudinal axis of the tri- quetrum, defined as a line passing through the distal triquetral angle and bisecting the proximal articu- lar surface, forms on average a 14- degree angle (range, +31 to Ð3 degrees) with the lunate longitudi- nal axis, defined as a line passing perpendicular to a line drawn from the distal dorsal and volar edges of the lunate. Lunotriquetral dissoci- ation results in a negative angle Positive Plain radiography Normal Arthrography Arthroscopy Relief Observe No relief Abnormal Abnormal No reliefRelief* Observe Initial relief* Arthroscopy Acute or sub- acute condition Chronic condition LT reconstruction or LT fusion ± recession or Repair if possible LT reconstruction or LT fusion ± recession or Repair if quality LT ligament available LT repair Repair Normal Negative X-ray motion studies Injection and immobilization LT dissociation ± VISI Optional three-phase arthrogram Abnormal findings Normal appearance Injection and immobilization Acute or subacute condition Chronic condition Provocative test History of wrist pain Consider other causes Consider other causes If recurrence, injection, immobilization, observation Figure 4 Algorithm for treatment of LT injuries. * = Relief is categorized as follows: ÒInitial reliefÓ designates transient relief secondary to anesthetic. ÒReliefÓ designates lasting relief secondary to effects of corticosteroid administration. Alexander Y. Shin, MD, CDR, USNR, et al Vol 8, No 3, May/June 2000 175 (mean value, Ð16 degrees) (Fig. 6). 1 If a VISI deformity is present with LT dissociation, the scapholunate and capitolunate angles will be altered. The scapholunate angle may be diminished from its nor- mal 47 degrees to 40 degrees or less but is often normal. 2 The lu- nate and capitate, which are nor- mally colinear, will collapse in a zigzag fashion, resulting in an angle greater than 10 degrees. Arthrography can be valuable, demonstrating leakage or pooling of dye at the LT interspace. How- ever, age-related LT membrane perforations, other communica- tions between the radiocarpal and midcarpal joints, and asympto- matic LT tears on arthrography of normal wrists have been reported. Therefore, the results of arthrogra- phy must be correlated with clini- cal examination findings. A video- taped arthrogram with motion sequences in flexion-extension and radioulnar deviation can further confirm the presence of LT injury by demonstrating abnormal pool- ing of the dye column and abnor- mal proximal-row kinematics. Videofluoroscopy is useful in demonstrating the site of a ÒclunkÓ that occurs with deviation. In LT sprains, this occurs with a sudden Òcatch-upÓ of the triquetrum into extension as the wrist moves into maximal ulnar deviation. Technetium-99m diphosphate bone scanning can be useful in identifying the site of acute injury, but is less specific than arthrogra- phy. 20 Bone scans prove helpful when standard films and motion studies are negative. Magnetic resonance imaging technology is not yet reliable for LT ligament imaging. Selective midcarpal injection of local anesthetic is also useful as a diagnostic tool. In our experience, resolution of pain with increased grip strength after injection has been a reliable indicator of LT in- jury. A poor response to injection suggests an extra-articular cause of the patientÕs symptoms. In the evaluation of LT injuries, wrist arthroscopy is both diagnos- tic and therapeutic. Wrist arthros- copy provides a means of directly evaluating the integrity of the LT ligament and allows identification and treatment of any associated pathologic changes. In our experi- ence, arthroscopy is the most accu- rate diagnostic modality and may replace all other studies. Carpal instability can be assessed by direct visualization and probing of the carpal articulations, and provoca- tive maneuvers can be performed at the same time. In the uninjured wrist, the articulations of the proxi- mal and distal rows are very inti- mate, with no separation between the carpal bones. However, in the injured wrist with carpal instability, these articulations are gapped or incompetent. Instability is graded with use of the Geissler classifica- tion 21 (Table 2). The LT ligament is best visual- ized from the radiocarpal arthros- copy portal between the fourth and fifth extensor compartments or from the portal radial to the sixth extensor compartment. The dorsal, volar, and membranous portions of the LT ligament must be visualized and palpated with a probe to eval- uate the integrity of the ligament. Midcarpal arthroscopy is the key to assessing the stability of the LT Figure 5 Images of a 27-year-old man with an LT ligament tear after a fall on the out- stretched dorsiflexed and ulnarly deviated wrist. A, Anteroposterior radiograph demon- strates the break in GilulaÕs arcs 1 and 2, with overlap of the lunate and triquetrum. B, Lateral radiograph demonstrates the VISI collapse of the carpus, implying injury to other supporting ligaments of the lunate and triquetrum. A B Figure 6 A, The normal LT angle averages +14 degrees. B, With LT dissociation, the average LT angle decreases to −16 degrees. (Reproduced from Shin AY, Bishop AT: Treatment options for lunotriquetral dissociation. Techniques Hand Upper Extremity Surg 1998;2:2-17. By permission of Mayo Foundation.) A B Lunotriquetral Instability Journal of the American Academy of Orthopaedic Surgeons 176 joint (Fig. 7). From the midcarpal perspective, the normal LT joint is smooth without a step-off or dias- tasis. Placement of a probe into the LT joint enables further assessment of the severity of any instability. In addition to the LT and scapholu- nate joints, the capitohamate articu- lation and the articular surfaces of the hamate, triquetrum, capitate, and lunate should also be inspected, as they may show changes due to abnormal kinematics. Treatment Several factors should be consid- ered in choosing the optimal treat- ment for LT injuries (Fig. 4). These include the amount of instability (static or dynamic), the elapsed time between injury and treatment (acute or chronic), and the presence of associated injury or degenerative changes. Symptoms of pain in LT ligament tears may be due to dy- namic instability or local synovitis or a combination thereof. Initial management of most acute and chronic tears without dissociation or VISI deformity should probably be nonoperative, with cast or splint immobilization. 1 Careful molding with a pad under- neath the pisiform will maintain optimal alignment as healing pro- gresses. Midcarpal corticosteroid injections can be helpful in decreas- ing synovitis. For acute and chron- ic dissociations with VISI collapse and chronic tears unresponsive to conservative management, opera- tive treatment is indicated. The goal of surgical intervention is the realignment of the lunocapi- tate axis and reestablishment of the rotational integrity of the proximal carpal row. A variety of procedures have been described, including LT arthrodesis, ligament repair, and ligament reconstruction. If con- comitant negative or positive ulnar variance or midcarpal or radiocarpal arthrosis is present, additional pro- cedures, such as ulnar lengthening or shortening, midcarpal arthrode- sis, or proximal-row carpectomy, may be indicated. Total wrist ar- throdesis may be appropriate if de- generative changes make other sal- vage procedures impossible. Repair of the LT ligament has been described by several authors. Reagan et al 1 demonstrated good results, as did Favero et al. 22 In the latter study, only 1 of 21 ligament repairs failed, and 90% of patients were satisfied with their outcome. The LT interosseous ligament is re- attached to the site of its avulsion, generally from the triquetrum. The technique is demanding, requiring use of multiple sutures passed through drill holes or suture anchors (Fig. 8). As the strong volar ligament is also disrupted, a combined dorsal- volar approach, as well as augmenta- tion of the repair by plication of the dorsal radiotriquetral and dorsal scaphotriquetral ligaments, may be of some value. Protracted immobi- lization is necessary. Patients who engage in strenuous pursuits or who have chronic instability or a poor- quality LT ligament may be best treated by ligament reconstruction. Table 2 Arthroscopic Classification of Tears of the Intracarpal Ligaments * Grade Description I Attenuation or hemorrhage of the interosseous ligament as seen from the radiocarpal space. No incongruency of carpal alignment in the midcarpal space. II Attenuation or hemorrhage of the interosseous ligament as seen from the radiocarpal space. Incongruency or step-off of carpal space. There may be slight gap (less than width of probe) between carpal bones. III Incongruency or step-off of carpal alignment as seen from both radiocarpal and midcarpal space. Probe may be passed through gap between carpal bones. IV Incongruency or step-off of carpal alignment as seen from both radiocarpal and midcarpal space. There is gross instability with manipulation. A 2.7-mm arthroscope may be passed through gap between carpal bones. * Reproduced with permission from Geissler WB, FreelandAE, Savoie FH, McIntyre LW, Whipple TL: Intracarpal soft-tissue lesions associated with an intra-articular fracture of the distal end of the radius. J Bone Joint Surg Am 1996;78:357-365. Figure 7 Midcarpal arthroscopic view of a 25-year-old man with left wrist pain after a fall onto the pronated and extended wrist. Clinical evaluation was consistent with iso- lated LT instability, which was confirmed by arthroscopy. Significant mobility and diastasis (curved arrow) and incongruity of the midcarpal articular surfaces (solid arrows) were found on both palpation and exploration with an arthroscopic probe. Triquetrum Lunate Probe Alexander Y. Shin, MD, CDR, USNR, et al Vol 8, No 3, May/June 2000 177 Ligament reconstruction with a distally based strip of extensor carpi ulnaris tendon graft is one option (Fig. 9). Unlike scapholu- nate ligament reconstruction, this technique, although demanding, yielded uniformly good results in two studies. 1,22 Unlike LT arthrod- esis, reconstruction preserves LT motion and offers the greatest like- lihood of restoration of normal carpal interactions. The observation of asympto- matic congenital LT coalitions and the finding of relatively little rela- tive motion between the lunate and the triquetrum led to the concept of LT arthrodesis (Fig. 10). 23 Perhaps technically less demanding than ligament reconstruction or repair, LT arthrodesis has become the technique of choice of many authors. However, the method is not with- out substantial problems. The re- ported nonunion rates range from 0% to 57%. 1,22,24-28 Use of Kirschner wires has been shown to result in an unacceptably high nonunion rate of 47%. 26 Use of compression screws may improve results, but nonunion remains a significant problem. A 9% nonunion rate has been reported with the Herbert screw, and use of conventional cor- tical screws has been associated with nonunion rates as high as 57%. 26-28 In a comparison of outcomes an average of 6.5 years after arthrode- sis, ligament repair, or reconstruc- tion in 65 patients with LT ligament injury, Favero et al 22 demonstrated that LT arthrodesis was inferior to reconstruction or repair. Of 21 pa- tients who underwent LT arthrode- sis, 52% had persistent pain and a 31% decrease in motion from pre- operative measures; 71% required A B C D Figure 8 Technique of LT ligament repair. A, After appropriate exposure of the dorsal proximal carpal row (ligament-sparing capsulotomy is shown) and determination that enough LT ligament is present to be repaired, the ligament is detached from either the tri- quetrum (as illustrated) or the lunate. B, The recipient bone bed is prepared, and several parallel Kirschner wires are placed to create a tunnel for sutures. C, Nonabsorbable hori- zontal mattress sutures are placed. D, Before securing the sutures, the lunate and tri- quetrum are immobilized in their anatomic positions by additional Kirschner wires. (Reproduced from Shin AY, Bishop AT: Treatment options for lunotriquetral dissociation. Techniques Hand Upper Extremity Surg 1998;2:2-17. By permission of Mayo Foundation.) Figure 9 Reconstruction is recommended if there is insufficient LT ligament. A, Kirschner wires are placed as guides for drill holes such that the tips meet along the volar corners of the lunate and triquetrum. B, Holes are created with the use of graduated hand awls. A distal- ly based radial strip of extensor carpi ulnaris is harvested and woven through the drill holes. C, The lunate and triquetrum are immobilized by Kirschner wires, and the tendon graft is secured to itself. (Reproduced from Shin AY, Bishop AT: Treatment options for lunotriquetral dissociation. Techniques Hand Upper Extremity Surg 1998;2:2-17. By permission of Mayo Foundation.) A B C Lunotriquetral Instability Journal of the American Academy of Orthopaedic Surgeons 178 further surgery; and 62% experi- enced significant complications. The nonunion rate was 38%. Ulno- carpal impingement necessitated additional surgery in 14% of pa- tients who underwent LT arthrode- sis; this complication was not seen with LT repair or reconstruction. In contrast, persistent pain was present in only 1 (12%) of 9 patients who underwent LT reconstruction and in only 3 (14%) of 21 patients who underwent LT repair. Motion was diminished only 11% with repair and actually increased 9% with reconstruction. All patients who underwent reconstruction returned to their previous occupa- tions, and only 1 required subse- quent surgery. The lower compli- cation rates, higher patient satisfac- tion, greater range of motion, and lower rate of subsequent reopera- tion suggest that LT ligament re- pair or reconstruction should be the primary method of treatment for LT injuries that require surgical intervention. Summary Lunotriquetral ligament injuries are often neglected, missed, or misdiagnosed, resulting in pro- longed ulnar-sided wrist pain. A careful history followed by a sys- tematic physical examination can often identify an injury to the LT ligament. Confirmation of the diagnosis by means of radiogra- phy, arthrography, or arthroscopy is essential before initiating treat- ment. Although treatment of LT lig- ament injuries remains controver- sial and several surgical options are available, our preference is liga- ment repair or reconstruction, which has demonstrated consistently better results than arthrodesis. Although surgical repair or reconstruction is technically challenging, it pre- serves LT ligament motion and offers the greatest likelihood of restoration of normal carpal kine- matics. A B C D Figure 10 Several methods of LT arthrodesis can be utilized. A corticocancellous slot (A and B) or winged graft bone (C) can be wedged in an appropriately created slot in the lunate and triquetrum and can then be secured with Kirschner wires. D, A preferred method is the denuding of the LT articular cartilage with preservation of the volar and proximal rims with placement of corticocancellous graft and fixation with a compression screw. (Reproduced from Shin AY, Bishop AT: Treatment options for lunotriquetral dis- sociation. 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