History

Tears of the triangular fibrocartilage are typically the result of a fall on the outstretched upper extremity. The ulna is driven distally and compresses the TFCC between itself and the lunate, producing a central or radial tear of the articular disk. This same mechanism can result in lunatotriquetral tears and peripheral TFCC tears, neither of which is discussed further here.

Forceful ulnar deviation, as observed in racquet sports and golf, can lead to TFCC tears. The combination of ulnar axial load and torque can be sufficient to tear the triangular fibrocartilage. Gymnastics, with its significant axial loading of the wrists, can also lead to a TFCC tear.

At least 50% of intra-articular distal radius fractures are associated with tears of the triangular fibrocartilage. However, many of these remain asymptomatic and require no treatment.

An ulnar abutment syndrome can develop as a result of settling of a distal radial fracture fragment. The radial collapse leads to a relative lengthening of the ulna. Palmer and colleagues² demonstrated an increase in the ulnocarpal load with increasing ulnar variance.

Repetitive axial loading of the wrist in a patient with an ulnar-zero or ulnar-plus variance can lead to an attritional tear of the triangular fibrocartilage and ulnar abutment syndrome.

Physical Examination

Ulnocarpal palpation can give some insight into the condition of the TFCC. The synovitis associated with a TFCC tear can render simple palpation of the ulnocarpal joint uncomfortable.

The ulnocarpal compression test (Fig. 22-3) is particularly helpful in assessing the patient with a suspected ulnar abutment syndrome. In this test, the patient sits in front of the examiner with the wrist in supination. The wrist is simultaneously ulnarly deviated and axially loaded while the forearm is supinated and pronated. The patient with an ulnar abutment syndrome experiences pain at the ulnocarpal joint, with or without popping and grinding, during this maneuver.

FIGURE 22-3 Ulnocarpal compression test.

A variation of the ulnocarpal compression test is the Lester press test (Fig. 22-4).³ In this test, the patient sits in a chair with sturdy arms and lifts himself or herself off the chair seat. Pain at the ulnocarpal joint is considered pathognomonic for a TFCC tear.

FIGURE 22-4 The Lester press test.

Diagnostic Imaging

The radiographic evaluation of a patient with an ulnar abutment should include a standard wrist series and a Palmer 90 × 90 view (Fig. 22-5). The Palmer 90 × 90 view places the forearm in neutral rotation while the elbow is flexed to 90 degrees and the shoulder is abducted to 90 degrees.⁴ The ulnar variance is calculated from this view. An ulnar abutment can be suspected in a patient with an ulnar-zero or ulnar-minus variance. The ulnar aspect of the lunate should be carefully examined for subchondral cysts.

FIGURE 22-5 Ulnar plus variance noted on a Palmer 90 × 90 view.

Magnetic resonance imaging (MRI) should be considered when evaluating the patient for ulnar abutment. MRI demonstrates increased signal in the lunate on T2 images (Fig. 22-6), corresponding to a cyst or intraosseous edema. The triangular fibrocartilage can also be evaluated on the MRI images. Whether a magnetic resonance (MR) arthrogram is needed is a function of the MR resolution. The accuracy of lower-resolution MR is increased with the addition of an intra-articular gadolinium injection.

FIGURE 22-6 Magnetic resonance image of a wrist with an ulnar abutment demonstrating the change in signal at the ulnar proximal lunate on T1-weighted and T2-weighted images.

Nonoperative Management

Immobilization of the involved wrist with a Munster splint or a long arm cast for 4 weeks, combined with a course of nonsteroidal anti-inflammatory medications, can be helpful in patients who present acutely. A TFCC tear that is exacerbated by specific activities occasionally responds to activity modification.

Indications

The failure of nonoperative treatment (splinting, rest, nonsteroidal anti-inflammatory medications, activity modification and therapy) leads the surgeon and patient to choose surgical treatment.

Preoperative Planning

Preoperative evaluation should include radiographs of the wrist, comprising a wrist series and a 90 × 90 view, as described by Andrew Palmer.² An MRI study, with or without an arthrogram, can also be helpful.

The patient must be informed that an arthroscopically assisted ulnar shortening may not be possible if there is laxity of the ulnocarpal ligaments, a peripheral TFCC tear, or a lunatotriquetral laxity. The amount of shortening should be calculated preoperatively. Arthroscopically assisted ulnar shortening is indicated if the ulnar-plus variance is less than 4 mm.

Positioning

The patient is placed in the supine position. A pneumatic tourniquet it is placed on the proximal arm. The patient’s involved extremity is prepared and draped in the usual fashion. The wrist is distracted with a commercially available wrist traction device.

Arthroscopic Technique

Triangular Fibrocartilage Complex Débridement: Mechanical

The standard 3-4 and 4-5 or 6-R wrist arthroscopy portals are used for TFCC débridement. These portals should be wide enough to permit the easy passage of instruments. A thorough and systematic examination of the radiocarpal, ulnocarpal, and midcarpal joints should be performed before débriding of the TFCC, as associated intrinsic and extrinsic ligament injury, articular derangement, or synovial pathology could affect the treatment plan. Ulnocarpal synovectomy should be performed to ensure clear visualization of that joint. The initial débridement of the radial, the palmar, and a portion of the dorsal aspect of the TFCC tear is accomplished with an arthroscope in the 3-4 portal while the instruments enter through the 4-5 portal. Small joint punches (straight and angled), graspers, mini-banana blades, and mini-hook knives are used to débride the TFCC. The suction punch is particularly useful. Care should be taken not to injure the overhanging lunate and triquetrum.

After the radial and palmar aspects of the TFCC have been débrided, the arthroscope is moved to the 4-5 portal. The débridement of the ulnar aspect of the triangular fibrocartilage is accomplished with passage of the instruments through the 3-4 portal. Three points must be kept in mind during débridement of the ulnar aspect of the TFCC. The first is to avoid injuring the attachment of the triangular fibrocartilage on its insertion at the base of the ulnar styloid. The second is to avoid injuring the dorsal or palmar radioulnar ligaments. If the ulnar attachment of the TFCC is transected or the dorsal and palmar radioulnar ligaments are injured, distal radioulnar joint instability will result. The third point is to avoid scuffing the articular surfaces while passing the cutting or grasping instruments from the 3-4 portal across the radiocarpal joint and into the ulnocarpal joint.

The dorsal aspect of the TFCC tear usually can be débrided through the 3-4 and 4-5 portals. Occasionally, the instruments need to be passed through the 6-U portal while the arthroscope is placed in the 3-4 portal. Injury to the dorsal sensory branch of the ulnar nerve is avoided when using the 6-U portal with a longitudinal portal incision and blunt dissection to reach the ulnocarpal joint capsule.

After the TFCC has been débrided with the punches and knives, the rough edges of the débrided TFCC are smoothed with the full radius cutters. The 2.0-mm cutters are small but relatively ineffective, whereas the 2.9-mm cutters are effective but must be controlled to avoid collateral damage to the adjacent articular surfaces.

The end point of TFCC débridement is reached when the ulnar head is visible through the TFCC and a stable TFCC perimeter is created (Fig. 22-7). Typically, a central defect measuring at least 1 cm in diameter is created.

FIGURE 22-7 The triangular fibrocartilage complex has been débrided back to a stable edge. The ulnar head is visible.

Arthroscopic Ulnar Shortening Technique

Arthroscopic ulnar shortening is accomplished by placing the arthroscope in the 3-4 portal and introducing the instruments through the 4-5 portal. Occasionally, the 6-U portal can be used, as can the distal radioulnar joint portal. Although the holmium:yttrium-aluminum-garnet (Ho:YAG) laser is very useful for ulnar shortening, the barrel abrader can be used alone or in combination with the laser. If the Ho:YAG laser is used, it is introduced through the 4-5 portal, and the cartilage and subchondral bone of the ulnar seat of the distal ulna are rapidly vaporized (Fig. 22-8A). The laser becomes less efficient after the trabeculae of the distal ulna are visible. At that point, the 2.9-mm barrel abrader is brought in to finish the shortening (Fig. 22-8B). It is important to avoid injury to the sigmoid notch, and frequent fluoroscopic monitoring of the amount of bone resected is mandatory. Care must be taken to fully supinate and pronate the wrist to adequately débride the ulnar head. All instruments are removed at the end of the procedure, and the wrist is ulnarly deviated, axially loaded, supinated, and pronated to be sure no clicking or popping can be heard. If any clicking or popping emanates from the area of the surgery, further ulnar resection may be required. The goal of the surgery is to create an ulnar-minus variance of 2 mm (Fig. 22-9). Any irregularities of the remaining distal ulna should be minimized. Small irregularities, however, have a tendency to flatten out with the passage of time.

FIGURE 22-8 A, The hyaline cartilage of the ulnar seat has been débrided with the laser. B, The subchondral bone is being débrided using the barrel abrader.

FIGURE 22-9 A, Preoperative radiograph. B, Preoperative radiograph.

PEARLS& PITFALLS

• Arthroscopically assisted ulnar shortening should not be combined with other procedures that require postoperative wrist immobilization, because early mobilization is critical after an ulnar shortening.

• The 4-5 and 6-R portals should be placed just distal to the distal surface of the TFCC, because distal placement of the portals can lead to scuffing of the lunate and triquetrum. The surgeon should be mindful of the presence of the dorsal branch of the ulnar nerve. This nerve is at risk during the creation of all ulnar portals.

• Injury to the underlying tendons and nerves can be avoided by creating portals using a no. 15 blade held gently against skin, which is moved beneath the blade. Small, transverse incisions in Langer’s lines, closed with a subcuticular Prolene, produce a superior cosmetic result. After the skin is cut, blunt dissection with a Hartmann hemostat should be used to dissect through the subcutaneous tissue and penetrate the wrist joint capsule. The curve of the Hartmann hemostat follows the palmar tilt of the distal radius.

• The 1.9-mm arthroscopes are perfectly suited to wrist arthroscopy. Their small size lessens the likelihood of scuffing of the wrist joint articular surfaces.

• Débridement of the TFCC tear must be performed carefully to avoid injury to the peripheral attachments of the TFCC and the dorsal and palmar radioulnar ligaments. Overaggressive débridement can lead to distal radioulnar joint instability.

• A systematic approach to excision of ulnar head is critical. The assistant must take the wrist from full supination to full pronation while the operator maintains the arthroscope in the 3-4 portal and the instruments in the ulnar portals. The ulnar head is débrided as it is presented to the surgeon by the assistant during rotation of the distal radioulnar joint.

• Rehabilitation of the patient is essential to the ultimate success of the procedure. The wrist should not be loaded for at least 4 to 6 weeks.

Postoperative Management

Postoperative care of these patients includes the application of a volar splint, followed by early range of motion. Early range of motion is critical, because it leads to a more supple scar and a better range of motion.

Wounds are closed using subcuticular sutures of 4-0 Prolene; the sutures are removed after 2 weeks. Strengthening exercises can be started at 6 weeks if needed. Premature resumption of heavy lifting or repetitive activities will lead to ulnocarpal synovitis. The patient is instructed to avoid heavy lifting for 3 months.

Typically, patients are able to return to unrestricted activities in 12 weeks, although they may experience some discomfort for 6 to 12 months.