TFCC peripheral tears and DRUJ instability: classification and treatment

1. In the Atzei classification of peripheral (Palmer 1B) TFCC tears, a class 3 lesion is an isolated rupture of the proximal attachment of the TFCC to the fovea that cannot be seen at radiocarpal arthroscopy.

True

Atzei, Luchetti and Garagnani subdivided the Palmer 1B tear into five treatment-oriented classes: class 1, an isolated distal tear without DRUJ instability (arthroscopic suture); class 2, rupture of both the distal component and the foveal attachment; class 3, an isolated foveal rupture invisible from the radiocarpal joint; class 4, an irreparable tear (distal radioulnar ligament reconstruction with a tendon graft); and class 5, a tear with DRUJ arthritis (salvage). Classes 2 and 3 are diagnosed with a positive hook test, are typically associated with DRUJ instability and are treated by reattaching the distal radioulnar ligament insertions to the fovea.

• Atzei A, Luchetti R, Garagnani L. Classification of ulnar triangular fibrocartilage complex tears. A treatment algorithm for Palmer type IB tears. J Hand Surg Eur Vol. 2017;42(4):405-414. PMID 28132592

2. Under dynamic muscle loading in a cadaver model, disruption of the foveal insertion of the TFCC destabilises the DRUJ more than disruption of the ulnar styloid insertion.

True

Haugstvedt and colleagues tested 12 fresh-frozen specimens in a dynamic simulator with the TFCC intact, foveally disrupted or styloid-disrupted. Without load the conditions did not differ, but under loading the foveal insertion had a greater effect on stability than the styloid insertion, with significant differences during pronation and supination under agonist loading. The deep limbs of the dorsal and palmar radioulnar ligaments insert on the fovea while the superficial limbs surround the disc and attach towards the ulnar styloid, which is why the fovea is the target of repair.

• 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(3):445-51. PMID 16516740
• Ishii S, Palmer AK, Werner FW, Short WH, Fortino MD. An anatomic study of the ligamentous structure of the triangular fibrocartilage complex. J Hand Surg Am. 1998;23(6):977-85. PMID 9848546

3. The radial attachment of the TFCC receives a capsular blood supply comparable to that of the ulnar periphery, so central and radial tears heal reliably after repair.

False

Bednar's microvascular study of 10 cadaver wrists showed small vessels entering the TFCC in a radial (spoke-like) pattern from the palmar, ulnar and dorsal capsular attachments to supply only the peripheral 10–40 %; the central portion is avascular and no vessels cross the radial attachment, so central and radial tears are not likely to heal. Thiru's injection study found vascularity confined to the outer 15–20 % of the disc. This is the rationale for debriding central tears and repairing peripheral ones.

• Bednar MS, Arnoczky SP, Weiland AJ. The microvasculature of the triangular fibrocartilage complex: its clinical significance. J Hand Surg Am. 1991;16(6):1101-5. PMID 1748756
• Thiru RG, Ferlic DC, Clayton ML, McClure DC. Arterial anatomy of the triangular fibrocartilage of the wrist and its surgical significance. J Hand Surg Am. 1986;11(2):258-63. PMID 3958460

4. Ulnar shortening osteotomy restores DRUJ stability even when the radioulnar ligament has been completely avulsed from the fovea, because it tensions the remaining TFCC.

False

In Nishiwaki's cadaver study, shortening the ulna by 6 mm increased DRUJ stiffness by 26–44 % with an intact ligament and restored intact-level stiffness after partial sectioning, but after complete sectioning of the radioulnar ligament at the fovea the joint remained significantly less stiff than intact even at 6 mm of shortening. Shortening therefore stabilises the DRUJ only while the ligament keeps a total or partial foveal attachment; a complete foveal avulsion needs reattachment or reconstruction.

• 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(4):719-26. PMID 16039364

5. Anatomical reconstruction of the distal radioulnar ligaments with a tendon graft (Adams–Berger) is indicated for chronic post-traumatic DRUJ instability with an irreparable TFCC, provided the articular surfaces of the DRUJ are intact.

True

Adams and Berger's original series treated 14 patients with post-traumatic instability and an irreparable TFCC; stability was restored in 12 of 14 at 1–4 years, and they concluded that the procedure is effective when the articular surfaces are intact and the other wrist ligaments are functional. In the largest series (95 wrists, mean follow-up 65 months) 90.8 % had a stable DRUJ and overall success was 86.3 %, with 12 revisions; a deficient sigmoid notch was linked to failure in the original series but did not affect the failure rate in the larger cohort.

• Adams BD, Berger RA. An anatomic reconstruction of the distal radioulnar ligaments for posttraumatic distal radioulnar joint instability. J Hand Surg Am. 2002;27(2):243-51. PMID 11901383
• Adams BD, Lawler E. Chronic instability of the distal radioulnar joint. J Am Acad Orthop Surg. 2007;15(9):571-5. PMID 17761613
• Gillis JA, Soreide E, Khouri JS, Kadar A, Berger RA, Moran SL. Outcomes of the Adams-Berger Ligament Reconstruction for the Distal Radioulnar Joint Instability in 95 Consecutive Cases. J Wrist Surg. 2019;8(4):268-275. PMID 31404256