Suture Anchor Repair of Ulnar-Sided Triangular Fibrocartilage Complex Tears

INTRODUCTION

The triangular fibrocartilage complex (TFCC) is a group of intimately related ulnar-sided wrist structures including the dorsal and palmar radioulnar ligaments, the articular disk, the meniscus homologue, the ulnar collateral ligament, the extensor carpi ulnaris subsheath, and the origins of the ulnolunate and lunotriquetral ligaments. Biomechanical studies indicate that the TFCC imparts translational stability to the distal radioulnar joint and buffers compressive forces during axial loading of the wrist (af Ekenstam and Hagert, 1985; Palmer, 1984, 1987; Palmer and Werner, 1981; Schuind et al., 1991; Werner et al., 1986). Tears of the TFCC can therefore result in instability of the distal radioulnar joint and in ulnar-sided wrist pain.

TFCC tears can occur either centrally or peripherally. The central 80% of the TFCC is essentially avascular; central tears, which tend to be degenerative, are therefore not thought to have healing potential. Peripheral tears, in contrast, especially those of the ulnar border of the TFCC, have a vascular supply based on palmar and dorsal branches of the anterior interosseous artery, the palmar and dorsal radiocarpal branches of the ulnar artery, and the ulnar head itself, and are therefore thought to have the capacity to heal (Bednar et al., 1991; Chidgey, 1991; Thiru et al., 1986). Traumatic tears tend to occur peripherally, and may be further classified as ulnar avulsions, distal avulsions, radial avulsions, or central perforations (Palmer, 1989).

Conservative treatment of the symptomatic TFCC tear includes rest, immobilisation, non-steroidal anti-inflammatory drugs (NSAIDs), steroid injections, and activity modification. Surgical treatment options depend on the location, morphology, and chronicity of the tear, and may include open or arthroscopic debridement, repair, excision, reconstruction, ulnar recession, ulnar shortening osteotomy, or distal radioulnar joint arthroplasty (Albert et al., 1963; Cooney et al., 1994; Corso et al., 1997; Darrow et al., 1985; Dell, 1987; Hermansdorfer and Kleinman, 1991; Imbriglia and Boland, 1983; Jantea, 1991; Kapandji, 1986; Linscheid, 1987; Menon et al., 1984; Nagle and Benson, 1992; Osterman, 1990; Palmer et al., 1988; Trumble et al., 1996; van der Linden, 1986; Watson et al., 1986).

Primary repair of peripheral TFCC tears has become increasingly popular. Although good results have been documented with open repair, recent work has championed arthroscopic repair, claiming improved visualisation, decreased disruption of surrounding structures, and improved final wrist motion and strength (Bednar and Osterman, 1994; de Araujo et al., 1996; Hanker, 1991; Skie et al., 1997; Zachee et al., 1993). Even its proponents, however, admit that arthroscopic repair can be technically demanding and time-consuming (Zachee et al., 1993).

As an alternative to these we describe a mini-open technique for the repair of traumatic ulnar-sided TFCC tears using a suture anchor placed in the ulnar fovea.

PATIENTS AND METHODS

Eight patients with traumatic ulnar avulsions of the TFCC repaired using our mini-open suture anchor technique were reviewed retrospectively. All surgeries were performed by the senior author (DGS) and follow-up averaged 4 years (range, 2–8 years). All eight patients initially complained of debilitating ulnar-sided wrist pain, which was aggravated by palpation over the distal ulnocarpal joint and usually exacerbated by forearm rotation and ulnar deviation of the wrist; two patients also complained of a painful click during forearm rotation. None had gross instability of the distal radio-ulnar joint on clinical examination. Five patients were women and three were men, and their average age was 31 (range, 19–49 years) at the time of injury. All patients were right-handed; the dominant wrist was injured in five. Six patients were injured as the result of a fall and two were injured while performing patient care duties. Four patients also sustained fractures of the distal radius and ulnar styloid at the time of injury. All patients had plain radiographs taken at the time of their initial office visit; all but one also had MRI scans and/or wrist arthrograms performed prior to their presentation to us. None had radiographic evidence of non-union of the distal radius, distal radioulnar joint arthritis, ulnocarpal impaction, or carpal instability. The time from injury to surgery averaged 197 weeks (range, 8–728 weeks). Excluding the two patients whose time to surgery was greater than 13 years, however, the mean time to surgery was 28 weeks.

SURGICAL TECHNIQUE

The procedure is performed under axillary block. After a systematic arthroscopic examination of the radio-carpal joint, including probing and ballottement of the TFCC, a 2 cm longitudinal incision is made over the ulnocarpal joint between the extensor digiti minimi and extensor carpi ulnaris tendons. The dorsal cutaneous branch of the ulnar nerve can often be identified through this incision and if so, is retracted dorsally. Dissection is then carried down to the joint capsule, which is incised in line with the skin incision.

The avulsed TFCC is identified and debrided. The ulnar fovea is roughened with a curette and drilled with a 1.8 mm bit, after which a single Mitek Mini Quick-Anchor (Mitek Products, Norwood, MA) is inserted into the drill hole. The torn ulnar border of the TFCC is then advanced and sutured down to the ulnar fovea (Fig 1). No additional suturing is necessary. The capsule, retinaculum, and skin are closed and a sterile dressing and long arm splint are applied.

Four patients had small, non-united avulsion fractures of the ulnar styloid and underwent styloid fragment excision in conjunction with the above procedure. Total operative time averaged 45 minutes.

Patients were kept in a long arm splint or cast for 4–6 weeks, after which immobilisation was discontinued and aggressive physical therapy was initiated. All patients resumed full, unrestricted activity at 3 months.

All eight patients were recently brought back to the clinic, at which time pain, functional status, motion (extension/flexion), and grip strength were assessed and graded according to the Mayo Modified Wrist Score (Table 1). Pronation and supination were also assessed. Range of motion and grip strength were measured with a standard goniometer and a Baseline Hydraulic Hand Dynamometer (Chattanooga Group, Hixson, TN), respectively. Preoperative and postoperative extension/flexion, pronation/supination, and grip strength values were compared using a two-tailed paired t-test. Pre-operative and postoperative pain, function, and Mayo Modified Wrist Scores were compared using the exact sign test.

RESULTS

Three patients had an excellent result and five had a good result according to the Mayo Modified Wrist Score. Three denied any wrist pain whatsoever, and five complained only of “mild” or “occasional” pain. Seven patients returned to regular employment (or unrestricted activity if not employed at the time of injury), and one returned to work with very minimal restrictions.

Final wrist extension/flexion averaged 132°, which was 89% of the unaffected side and comparable to a preoperative value of 140°. Final pronation/supination averaged 145°, which was 83% of the unaffected side and improved from a preoperative value of 126°, although this difference was not statistically significant. Excluding patient 8, whose DRUJ had been surgically fused at the time of final follow-up and whose outcome will be discussed separately, final pronation/supination averaged 166°, which was 95% of the unaffected side and significantly improved from a preoperative value of 124° (P < 0.0025). Final grip strength averaged 37 kg, which was 88% of the unaffected side and significantly improved from a preoperative value of 23 kg (P < 0.026). Final pain score averaged 22, which was significantly better than a preoperative value of 8 (P < 0.008). Final function score averaged 24, which was similar to a preoperative value of 21. Final Mayo Modified Wrist Score averaged 88, which was significantly improved from a preoperative value of 62 (Table 2; P < 0.008).

Patient 8 was a young man on workers’ compensation whose initial wrist injury had occurred 14 years prior to repair of his TFCC, and who had been unemployed for several years at the time of his presentation to us. Postoperatively, he complained of persistent incisional tenderness and pain with forearm rotation, and required excision of an incisional neuroma 8 months after his index procedure. Despite resolution of his incisional tenderness, he continued to have pain with forearm rotation and subsequently underwent several surgical procedures culminating in arthrodesis of the distal radioulnar joint. He continues to complain of mild ulnar-sided pain and sensitivity that is exacerbated by deep palpation. Although he had a good result at final follow-up according to the Mayo Modified Wrist Score, we rate his result as poor given his need for numerous subsequent surgical interventions.

DISCUSSION

Hermansdorfer and Kleinman (1991) were the first to report the results of open TFCC repair performed through drill holes in the distal ulna. They reviewed 13 consecutive ulnar-sided TFCC repairs, of which 11 had sufficient follow-up data. Final postoperative grip strength averaged 87% and motion 96% of the contralateral side. Three patients experienced complete relief of their preoperative pain, five had “mild discomfort with heavy use”, and three complained of “a level of pain incompatible with their normal wrist demands”. As originally described, their technique requires a 6 cm long incision, although we feel that the procedure can probably be performed through a somewhat smaller incision.

In the largest study of open TFCC repairs to date, Cooney et al. (1994) reviewed 33 TFCC repairs, only five of which were ulnar-sided. Repair was again performed by suturing the torn TFCC to the distal ulna via drill holes. Mayo Modified Wrist Score averaged 83 in these five patients, with one excellent and four good results overall. Pain, functional status, motion, and grip strength, however, were not reported separately for this subset of patients.

Trumble et al. (1996) and Corso et al. (1997) have since presented their experience with arthroscopic repair of the TFCC. In 11 patients with ulnar-sided tears repaired by Trumble et al. (1996), final grip strength averaged 83% and motion 91% of the contralateral side. Total pain relief was attained in ten of the 11 patients, and seven returned to regular employment and/or athletic activity. Corso et al. (1997) subsequently published a multicentre study of 45 arthroscopic TFCC repairs but did not stratify his results by tear location. Outcomes according to the Mayo Modified Wrist Score were excellent in 29, good in 12, fair in one, and poor in three. Pain, functional status, motion, and grip strength were not described in detail. It is notable that their technique, while primarily arthro-scopic, also requires a 1.5 cm long incision, through which the dorsal cutaneous branch of the ulnar nerve can be identified and protected during the passage and tying of sutures.

We propose a mini-open technique utilising a single suture anchor placed in the ulnar fovea. Repairs performed in this fashion are simple and results achieved are similar to those obtained with conventional open or arthroscopic techniques.