Repairing tears of the triangular fibrocartilage complex

Indications for repair include tears of the triangular fibrocartilage complex (TFCC) that cause persistent pain and/or distal radioulnar joint (DRUJ) instability.

Another indication for repair involves symptomatic TFCC injuries that are refractory to conservative treatments (usually at least 6 weeks of immobilization).

Peripheral tears of the TFCC are amenable to repair owing to better blood supply, whereas tears of the relatively avascular central zone of the TFCC are not ( Fig. 20.1 ).

The Palmer classification system categorizes TFCC injuries as traumatic or degenerative. This chapter will focus on the treatment of Type 1 (traumatic) TFCC lesions ( Table 20.1 ). Type 1A ( Fig. 20.2 ) lesions are treated with debridement but not with repair because the central disk does not tend to heal. Types 1B, 1C, and 1D are all candidates for arthroscopic or open repair. Type 1B lesions are the most common and are the subject of this chapter.

TFCC injuries often present as ulnar-sided wrist pain.

Acute injuries are associated with a fall, especially on an outstretched and pronated hand, or with an aggressive traction or torque event.

Patients may complain of clicking, popping, or locking during pronosupination.

To look for a positive fovea sign, palpate the soft spot of the ulnar wrist, just distal to the ulnar styloid and proximal to the pisiform, between the ECU and flexor carpi ulnaris tendons. Substantial pain with deep palpation here is a positive fovea sign (supporting the diagnosis of a peripheral TFCC tear).

To complete an ulnocarpal stress test, with the patient’s elbow bent at 90 degrees, the examiner puts their nondominant hand under the elbow and grips the palm/carpus of the affected hand with a handshake-style grip. The examiner then maximally ulnarly deviates the patient’s hand, and, while holding this axial ulnar load, the examiner puts the joint through passive pronation and supination. Reproduction of symptoms is a positive test indicating likely TFCC pathology (a nonpainful click is not considered positive).

The ballottement test evaluates DRUJ stability ( Fig. 20.3 ). Grasp the radius in the examiner’s nondominant hand and the distal ulna with the dominant index finger and thumb, then move the distal ulna volar and dorsal relative to the radius. Soft endpoints, pain, and/or notable instability compared with contralateral all indicate DRUJ instability.

To look for a piano key sign, with the wrist in pronation, note the position of the ulnar head. A notably prominent ulnar head that shifts down with volarly directed pressure and then recoils to the dorsally displaced position indicates DRUJ instability (positive piano key sign).

Although the TFCC cannot be seen on x-rays, it is important to evaluate standard posteroanterior (PA), lateral, and oblique images. To properly assess ulnar variance, the PA x-ray should be taken with the forearm in neutral rotation, elbow flexed to 90 degrees, and shoulder abducted to 90 degrees. Obtain similar x-rays of the contralateral side for comparison.

• Indicators of possible TFCC injury (especially acute) include ulnar styloid fracture and/or DRUJ incongruity.

• Other sources of ulnar-sided wrist pain or contributors to TFCC pathology include ulnar positive variance, ulnar styloid nonunion, widened lunotriquetral interval indicative of LT ligament injury, cystic changes in the lunate indicative of impaction, and DRUJ arthritis.

Triple injection arthrogram can be used in evaluation but has a moderately high false negative rate. It has generally fallen out of favor as magnetic resonance imaging (MRI) has improved.

Modern MRI machines have sensitivity and specificity around 90% or better for identifying TFCC injury; however, peripheral injuries have the lowest diagnostic accuracy and findings may depend on the experience of the radiologist.

The standard diagnostic modality is arthroscopy.

Identifying the area of the TFCC that is injured guides the surgical approach.

The TFCC is composed of the triangular fibrocartilage (TFC, otherwise known as the articular disk ), meniscus homologue, radioulnar ligament (RUL), ulnotriquetral ligament, ulnolunate ligament, ECU subsheath (not included in the figure image), and ulnar joint capsule ( Fig. 20.4 ).

• Injuries to the TFC are the most commonly discussed (and treated) component of TFCC injuries.

• Nevertheless, evaluating the other components of the TFCC that contribute to DRUJ stability is critical, especially when DRUJ instability is part of the presenting problem.

The TFCC attaches radially along the sigmoid notch of the radius and ulnarly along the ulnar fovea ( Fig. 20.5 ). Injuries that result in tearing of the TFCC in either of these two attachment zones are appropriate for repair.

The TFC attachment to the ulna has superficial and deep components (see Fig. 20.5 ) that must be considered during the evaluation and repair of TFCC injuries.

• The superficial component attaches to the styloid.

• The deep component attaches to the ulnar fovea.

• Ulnar styloid nonunion in the setting of TFCC peripheral tear often warrants excision of the styloid segment before the TFCC repair/reanchoring procedure.

For arthroscopic approaches to TFCC evaluation and repair, combinations of the dorsal 3 to 4, dorsal 4 to 5, and 6-R or 6-U portals are often used. Additionally, many surgeons will also use radial and ulnar DRUJ arthroscopy portals ( Fig. 20.6 )

Before repair (either during arthroscopy or after the open exposure), evaluate the lunate, triquetrum, and ulnar head for signs of impaction and associated chondromalacia.

The patient is placed supine on the operating room table.

A standard arthroscopy setup is used, with elbow at 90 degrees and upper arm secured to the hand table.