History and Physical Examination

Historically, patients may not recall a specific inciting event. Commonly, LT interosseous ligament tears associated with instability result from a single traumatic event, such as a twisting injury or a fall on an outstretched hand with a pronated forearm. The axial and dorsally directed forces result in wrist extension with radial deviation.^15,16 With intercarpal pronation, disruption of the LT interosseous ligament, and associated injury to the disk-triquetral and disk-lunate ligaments, tearing occurs, and LT instability may be greater.

After a general wrist examination, including inspection, palpation, and general range of motion and stability, an examination focused on ulnar-sided pathology is carried out. Patient localization of pain is helpful; diffuse, nonlocalizing pain is not typical of ulnar-sided instability. The dorsal and volar aspects of the TFCC, the dorsal LT joint, and the extensor carpi ulnaris (ECU) are the main areas to palpate. Depending on the acuteness of the injury, tenderness may or may not be present. Maneuvers to provoke pain caused by excessive unwanted translation of the triquetrum and lunate further elucidate ulnar-sided pain complaints. Although none of the tests is diagnostic in isolation, when performed as part of the comprehensive evaluation, the tests can better characterize pain complaints. Provocative stability maneuvers used to assess the LT joint include LT ballottement (compressing the triquetrum against the lunate), the shuck test as described by Reagan and colleagues,⁶ the shear test as described by Kleinman,^17,18 and distal radioulnar translation (to infer stability).^9,19 In addition to ulnar impaction testing, ulnar deviation should be performed with the wrist in flexed, extended, and neutral positions. The stability of the distal radioulnar joint is also assessed. Assessing the patient response to provocative maneuvers and comparing perceived translation with the contralateral wrist are useful.

Diagnostic Imaging

The radiographic evaluation of a painful wrist should start with a minimum of a zero rotation posteroanterior^20,21 view and a true lateral view of the wrist. Comparison views of the contralateral wrist are useful. In these radiographic views and after assessment of the soft tissue shadows, specific osseous relationships should be documented. The focused analysis includes ulnar variance,²² LT interval, integrity of the subchondral joint surfaces, greater and lesser arc continuity,²³ and radiolunate and scapholunate angles.

The clinical value of advanced radiographic evaluation of the wrist is subject to geographic variability. Magnetic resonance imaging (MRI) with or without the addition of arthrography is beneficial, provided an expert radiologist is available. Variations in the accuracy of MRI and diagnostic arthroscopy may simply be related to skills of the radiologist and the arthroscopic surgeon. In general, a high field magnet with a dedicated extremity helps to optimize spatial resolution.²⁴ Assessment of the LT joint is variable²⁵ and should be made in the context of the history and physical examination.

Indications and Contraindications

The primary contraindication to arthroscopic surgical treatment of LT instability is VISI and severe volar extrinsic ligament tearing. Indications for arthroscopic treatment of static LT instability include isolated LT instability and LT instability in combination with triangular fibrocartilage tears and ulnar impaction.

Conservative Management

Initial treatment for acute LT ligament tears without associated VISI can be short arm cast immobilization with the wrist in neutral position. Steroid injections may be of benefit, based on anecdotal reports.

Surgical Management

With failure of conservative treatment or unstable injuries, arthroscopic treatment of is a reasonable option and includes radiocarpal and midcarpal arthroscopy. The first step is to assess the degree of instability²⁶ and associated injuries. Partial LT injuries may be treated with débridement alone.^27,28 In 1995, Osterman and Seidman²⁹ combined débridement with isolated pinning of the LT joint and reported good results. Nonarthroscopic treatment, although not the focus of the chapter, has been described. In a comparison of techniques,³⁰ subjective results tended to be better for direct repair or reconstruction than for LT fusion.

Arthroscopic Technique

An arthroscopic video system should be positioned to allow a clear view of the monitor by the surgeon and assistant. After the limb is exsanguinated, a traction tower is used, and 8 to 10 pounds of traction is applied through finger traps with the arm strapped to the hand table. The portals used for arthroscopic stabilization include the 3-4, 6-R, volar 6-U, and radial and ulnar midcarpal portals for the arthroscopic capsulodesis and ARIF. Depending on each unique case, the addition of a 4-5 portal as a working or viewing portal can be helpful. The LT joint can be visualized directly from an ulnar portal (6-R or 4-5) to ensure complete, dorsal to palmar visualization of the LT ligament (Fig. 24-1) and débridement as necessary. After identification of pathology and débridement, an ulnar portal at the level of the volar ligaments, volar 6-U, is created after midcarpal assessment and is used for suture passing.

FIGURE 24-1 A lunotriquetral ligament tear is seen from the 6-R portal.

Starting with the arthroscope inserted into the radial midcarpal portal, the surgeon creates an ulnar midcarpal portal for the working portal. The LT joint is assessed for congruency and laxity of the triquetrum. The lunate and triquetrum should be colinear. If the view of the LT joint from the midcarpal radial portal is blocked by a separate lunate facet,³¹ the arthroscope is placed in the midcarpal ulnar portal to gain visualization. Under these conditions, the radial articular edge of triquetrum should be aligned with the most ulnar articular edge of the hamate facet of the lunate (Fig. 24-2). The LT joint may be unstable because of excessive laxity while still being congruent. Laxity should be assessed both on triquetral rotation and on separation from the lunate. From the midcarpus, the dorsal portion of the triquetrum is often rotated so that its articular surface is distal to the lunate in an unstable LT joint (Fig. 24-3). The triquetrum can be translated to a reduced state in which the articular surfaces of the triquetrum and lunate are collinear. Further, the triquetrum can be ulnarly translated so as to “gap open” the LT joint. Normal scapholunate joint laxity can be used as a reference. Also, the dorsal radiocarpal and dorsal intercarpal ligaments attached to the lunate and triquetrum may be avulsed (Fig. 24-4) and should be repaired.

FIGURE 24-2 A, The lunotriquetral joint (triquetrum is right) with a step-off is seen from the ulnar midcarpal portal with a probe inserted from the radial midcarpal portal. B, The triquetrum has been reduced, stabilized with Kirschner wires, and made congruent with the lunate (left).

FIGURE 24-3 As seen from the radial midcarpal portal, the dorsal portion of the triquetrum is rotated distally with respect to the dorsal portion of the lunate.

FIGURE 24-4 As viewed from the radial midcarpal portal, the dorsal radiocarpal ligament is avulsed.

After confirmation of LT instability, the arthroscope is placed in the 3-4 portal during ulnocarpal (UL, ulnocapitate, UT) ligament plication. The volar 6-U (v6-U) portal is established. The v6-U portal is similar to the normal 6-U portal, but it is placed just dorsal to the disk-carpal ligaments (Fig. 24-5). Care is taken to avoid injury to the dorsal sensory branches of the ulnar nerve during placement. The UL and UT ligaments are gently débrided to induce a vascular response. Through the v6-U portal, an 18-gauge spinal needle is passed just volar to the ulnocarpal ligaments and enters the wrist at the radial edge of the UL ligament, just distal to the articular surface of the radius (Fig. 24-6A). A 2-0 polydioxone (PDS) suture is placed through the needle into the joint. The suture is retrieved through the 6-R or the v6-U and tagged as the first plicating suture (see Fig. 24-6B and C). In a similar fashion, the second plicating suture is placed approximately 5 mm distal to the first (Fig. 24-7A), so that the suture loops are parallel to the lunate and triquetrum, and is tagged as the second plicating suture (see Fig. 24-7B and C). Tension on the first stitch often facilitates a second needle passage through the UL and UT ligaments. Adequacy of the plication (tension on the stitch) and its effect on LT interval stability should be assessed after each suture passage. Finally, the spinal needle is passed through the volar aspect of the capsule at the volar-most aspect of the TFCC at the prestyloid recess, as in peripheral repair techniques (Fig. 24-8A). The three sets of sutures are tied at the termination of the procedure, after the LT joint has been congruently reduced and stabilized with Kirschner wires (see Fig. 24-8B).

FIGURE 24-5 The spinal needle has entered the radiocarpal joint at the level of the ulnar carpal ligaments. Some fraying of the disk-carpal ligaments is seen and is associated with lunotriquetral ligament injury.

FIGURE 24-6 A, The spinal needle has traversed from ulnar to radial aspects just palmar to the ulnar carpal ligaments. The tip of the needle has again entered the radiocarpal joint radial to the disk-carpal ligament. The lunate is above, and the ulnar border of the distal radius (lunate fossa) is seen obliquely at the level of the spinal needle. B, A 2-0 polydioxone (PDS) suture has been passed through the spinal needle and retrieved out the volar 6-U portal. The disk-carpal ligaments are visualized with the lunate above. C, Suture passage is diagrammatically represented. The first 2-0 PDS plication suture is passed from ulnar to radial aspects with a spinal needle through the volar 6-U portal and incorporates the ulnocarpal (ulnotriquetral, ulnocapitate, ulnolunate) ligaments.

FIGURE 24-7 A, The ulnotriquetral ligament is to the left. The first plicating suture is seen below and to the right (ulnar), exiting ulnarly through the volar 6-U portal. The spinal needle is seen distally as it is ready to be passed for the second plicating suture. B, The second 2-0 polydioxone (PDS) plication suture is placed. Tension on the first suture facilitates placement of the second suture, which is placed approximately 5 mm distal to the first suture. C, The plication sutures are represented diagrammatically.

FIGURE 24-8 A, The ulnar capsular tension suture is placed. The suture is passed through the ulnar capsule and through the palmar aspect of the peripheral edge of the fibrocartilage complex (TFCC). B, Line drawing of the two plication sutures and the prestyloid and TFCC sutures.

With the arthroscope in the midcarpal radial portal, a spinal needle can be placed from the ulnar to the radial side across the distal aspect of the LT as a guide for percutaneous Kirschner wire placement with or without concurrent fluoroscopy (Fig. 24-9). After the triquetrum has been reduced through the midcarpal ulnar portal with a probe and traction on the plication sutures, the initial 0.045-inch smooth Kirschner wire is inserted just proximal to the spinal needle and drilled across the LT joint. The second Kirschner wire is placed just proximal to the first (Fig. 24-10). Traction is released after Kirschner wire stabilization, and the forearm is held in neutral rotation while the plication sutures are tied (Fig. 24-11). The Kirschner wires are either cut subcutaneously or bent outside the skin.

FIGURE 24-9 The viewing portal is in the midcarpal space during arthroscopic reduction and pinning of the lunatotriquetral joint. A needle has been placed into the midcarpal space to act as a guide for Kirschner wire placement.

FIGURE 24-10 Two parallel Kirschner wires through the lunotriquetral joint have been passed under direct visualization from the midcarpal joint.

FIGURE 24-11 The sutures and Kirschner wires are in place. Retractors can be used to retract soft tissue and protect the ulnar nerve sensory branches.

In the presence of a peripheral triangular fibrocartilage tear, sutures should be passed after the plication sutures and tied separately in the dorsal incision; central triangular fibrocartilage tears can be débrided during the initial débridement. Patients with LT tears often have positive ulnar variance.^32,33 In the presence of ulnar-positive ulnar impaction, an arthroscopic wafer procedure should be considered.

Postoperative Rehabilitation

After surgery, the patient’s extremity is placed into a long arm splint with the elbow flexed at 90 degrees and the forearm and wrist in neutral position. At 2 weeks after surgery, the wounds are assessed and a long cast or a Muenster cast is applied with the forearm and wrist in neutral position. At 6 weeks after surgery, the Kirschner wires are removed and a removable long arm or Muenster splint is used for the ensuing 2 weeks. Supervised therapy at this point includes active and active-assist wrist flexion, extension, pronation, and supination within a painless arc of motion, with progressive motion as tolerated. At 8 weeks after surgery or when motion is almost restored, strengthening exercises are instituted. Return to activities as tolerated typically occurs at approximately 24 weeks after surgery.