Surgical Repair of Acute TFCC Injury

Abstract

Triangular fibrocartilage complex tears are a common source of ulnar-sided wrist pain and distal radioulnar joint instability. Symptoms recalcitrant to conservative management or injuries in high-demand athletes may indicate surgical management. Both open and arthroscopic techniques offer improvements in objective measures, patient-centered outcome scores, and return to work, but may be complicated by nerve irritation, persistent wrist instability, and pain. Recently developed knotless arthroscopic techniques are not well studied but may limit morbidity.

Introduction

The triangular fibrocartilage complex (TFCC) is a soft tissue complex that spans, stabilizes, and tensions the ulnocarpal joint and the distal radioulnar joint (DRUJ). The complex consists of several ligaments, a meniscal homolog, and an articular disk. The most critical ligaments of DRUJ instability include the dorsal and volar radioulnar ligaments. These ligaments contain both a superficial and a deep portion, which attach at the ulnar styloid and ulnar fovea, respectively.^1-4 An articular fibrocartilage disk, which serves to dissipate axial loads, covers the ulnar head and is confluent with the edges of the radioulnar ligaments. The articular disk is at risk of structural injury radially as the radial-oriented fibers of the peripheral aspect meet the oblique fibers of the central portion of the disk.^4,5 While the fibrocartilage disk typically bears 20% of axial load through the wrist,⁶ this distribution increases with ulnar deviation and pronation and may also be increased by ulnar length.^4,7 The TFCC vascularity is supplied by the anterior interosseous and ulnar arteries, although only a quarter of the TFCC is perfused.^8,9 The limited vascularity of the TFCC, combined with its intricate soft tissue structure and torsional and axial stresses, makes the TFCC prone to frequent injury while maintaining a limited ability to heal.

Clinical Exam

The differential diagnosis of ulnar-sided wrist pain is broad.^10-12 Triangular fibrocartilage complex injuries often occur after a patient sustains an axial load on a hyperpronated wrist.¹¹ Upon visual inspection of a patient with an unstable TFCC injury, the ulnar head may be prominent dorsally, as the radius subluxates in the volar direction. With the wrist in pronation, the relative dorsally displaced ulnar head may be reduced volarly to the radius with direct pressure or elicit pain, indicating an abnormal piano key sign.⁴ Passive manipulation yielding increased translation of the radius on the ulna, in the anteroposterior direction with the forearm in pronation, supination, and neutral position, is indicative of DRUJ instability. Assessment is performed by determining the translation extent and end point firmness relative to the contralateral side. In one prospective study investigating TFCC peripheral tears causing DRUJ instability after distal radius fractures, physical examination of DRUJ instability had 59% sensitivity, 96% specificity, 91% positive predictive value, and 78% negative predictive value relative to arthroscopic findings.¹³ Foveal tenderness, between the flexor carpi ulnaris and pisiform, triquetrum, and ulnar styloid, is 95% sensitive and 86% specific of a TFCC injury.¹⁴ Tenderness or subluxation of the extensor carpi ulnaris (ECU) can be indicative of ECU tendonitis or instability and should be distinguished from DRUJ instability and TFCC pathology.⁴

Radiographic imaging consists of 3 views with bilateral anteroposterior and lateral views of the neutral wrist and a pronated grip view to determine ulnar variance.⁴ A recent meta-analysis of diagnostic imaging in TFCC injuries determined the sensitivity/specificity of magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) to be 72% to 80%/77% to 86% and 70% to 84%/77% to 92%, respectively, using either arthroscopic or open surgical findings as the standard.¹⁵ In addition to abnormal signal within the TFCC, MRI may also demonstrate signal within the carpi, which may indicate impaction, and signal within the ECU, which may indicate ECU tendonitis. The most common impaction syndrome is ulnar impaction, also known as ulnar abutment or ulnocarpal loading, and is associated with chronic, degenerative TFCC lesions that occur when the distal ulna affects the carpi, particularly the lunate. Bone signal changes consistent with chondromalacia and subchondral cysts¹⁶ are seen on the ulnar side of proximal lunate (87%), radial side of proximal triquetrum (43%), and distal ulna (10%).¹⁷ Less invasive MRI and subsequent arthroscopy have generally supplanted MRA.⁴ However, the rate of false positives with MRI is high (38%),¹⁸ and the findings on MRI must be corroborated with a complete history and physical examination.

Management

The TFCC tears are generally classified as acute traumatic or chronic degenerative tears based on the Palmer system.³ The latter are often associated with ulnar-positive variance and impingement. Typically, nonoperative management consisting of activity modification and below-the-elbow immobilization is first attempted for 3 months for acute traumatic tears prior to diagnostic arthroscopy with possible surgical repair.⁴ Intraarticular corticosteroid injections into the TFCC may prove both diagnostic and therapeutic but are more strongly considered for those who are not interested in surgical management.¹¹ While stable central perforations may be managed with rest and anti-inflammatory medications, those with physical examination and MRI findings indicative of DRUJ instability should be placed in an above-the-elbow splint for 4 to 6 weeks.⁴ Additional imaging with bilateral computed tomographic scans may demonstrate sigmoid notch incongruity, which is associated with higher levels of upper-extremity dysfunction postoperatively if the coronal step-off is greater than 1.0 mm.¹⁹ If symptoms of DRUJ instability persist following a period of immobilization, then open reconstruction is offered in our practice.

Operative management is indicated for persistent DRUJ instability, recalcitrant ulnar-sided wrist pain with concordant physical examination and imaging, acute injuries in high-demand patients,²⁰ or chronic degenerative tears with ulnar impingement. Over 40% of patients with a TFCC injury may eventually elect for operative management.²¹ Diagnostic arthroscopy allows for direct visualization and manipulation of the TFCC. The ability of the TFCC to be elevated or “hooked” with the probe is significant for an unstable TFCC, and surgical repair is indicated.^22,23

Operative Management

Open approaches to the ulnar aspect of the wrist were described in the 1980s^24,25 and have subsequently been modified for open TFCC repair.^26,27 Advocates of the open approach report that this method offers improved exposure to the DRUJ and may be more appropriate for complete TFCC lesions or in cases of frank DRUJ instability. A 3-cm dorsal incision is made over the fifth compartment centered over the DRUJ.²⁶ Rectangular retinacular flaps are raised to preserve the stability of the ECU.²⁵ Capsular flaps are subsequently developed to expose the head of the ulna and TFCC. Several reports describe this imbrication of the capsule alone is enough to stabilize the DRUJ and provides excellent functional outcomes.^28-30 The fovea is prepared and the TFCC is secured with a 2-0 nonabsorbable suture. An ulnar bone tunnel is made in an anterograde fashion to the fovea. The suture is passed through the tunnel and secured to the ulna with a knotless anchor. Two bone tunnels may be created with Kirschner wires and tied over a bone tunnel on the ulna as well.

Arthroscopic repairs involve less dissection than an open procedure, may prove less morbid, and are currently more popular than open techniques.²¹ An arthroscopic repair typically includes a mattress suture configuration securing the TFCC to the dorsal capsule with nonabsorbable monofilament.^22,31-34 However, certain implants³⁴ or a dorsal capsule knot³¹ may remain a prominent source of irritation for the patient. Even all-inside arthroscopic techniques may leave a prominent knot.^22,35 Outside-in, or arthroscopic-assisted transosseous, techniques include a drill tunnel through the ulna through which suture is passed to secure the TFCC, which can be tied over a bone tunnel^35-37 or secured with a knotless anchor^38-40 (Figure 1).

Figure 1.

Arthroscopic-assisted transosseous triangular fibrocartilage complex (TFCC) repair: (a) ulnar avulsion of the TFCC. The probe elevates a frayed ulnar flap. (b) The TFCC flap is debrided and then pierced in an anterograde fashion through a single drill hole in the ulna. (c) Slack is maintained over the TFCC when passing the suture so as to not lacerate the TFCC. (d) The TFCC is tensioned proximally with a single push-lock anchor into the ulna just proximal to the anterograde drill tunnel.

* indicates TFCC.

Postoperatively patients are immobilized in an above-the-elbow splint in neutral position, limiting pronation and supination for 4 weeks. At this point, the splint is removed and patients are transitioned to a removable short arm splint for an additional 3 weeks. Range of motion is then advanced before the patient begins to work on strengthening.^38-40

Outcomes

Reports of surgical outcomes following arthroscopic TFCC repair consist primarily of small (8-48 patient) retrospective case series with mid-term follow-up (29-48 months).^{22,31,32,35,41,42} Weighted averages of outcome measures in these series include Disabilities of the Arm, Shoulder and Hand (DASH) (13%), Mayo Modified Wrist Score (MMWS) (89%), return to work (82%), and range of motion compared with contralateral side (94%). Complications were inconstantly reported but included DRUJ instability (18%³⁵) and dorsal sensory branch of the ulnar nerve (DSBUN) paresthesia (10%²²).

Only one analysis reported long-term follow up after arthroscopic TFCC repair.⁴³ At 20-year follow-up after inside-out TFCC repair with a knot over the dorsal capsule, 63% experienced good to excellent results with a median MMWS of 85 and only one patient had DRUJ instability on examination. Patients had 94%, 98%, and 85% of flexion-extension arc, pronation-supination arc, and grip strength, respectively, compared with the contralateral side. All patients, but one, were satisfied and would undergo the procedure again.

The generally positive postoperative outcomes following TFCC repairs reported in case series may have limited external validity without knowing the patient’s preoperative functional demands. One series of 25 professional athletes (14 tennis players and 11 golfers) with negative or neutral ulnar variance underwent arthroscopic TFCC repair with tying of the avulsed articular disk back to the capsule and ECU subsheath.⁴⁴ These athletes were permitted to return to full grip and activity at 6 weeks. No other functional results were noted, and the outcomes in high-demand athletes represent a gap in the literature.^45-47

While case series predominate the literature, a handful of comparative studies exist between open and arthroscopic TFCC repair. A retrospective review analyzed 24 arthroscopic transosseous and 66 open TFCC repairs with 3-year follow-up.³⁷ Good to excellent results were achieved in 66% of the arthroscopic group and in 94% of the open group. Distal radioulnar joint instability (29% and 15%) and persistent pain (8% and 3%) were present in both the arthroscopic open group. Despite their stated preference for the arthroscopic technique, the authors attribute their potentially worse results with the arthroscopic group to a delay in treatment which averaged 19 months (range = 7 months to 4 years) from time of injury to surgery. The authors believe that surgical delay beyond 7 months after injury may precipitate a lack of healing capacity of the fovea.

One prospective, nonrandomized comparison of open versus arthroscopic TFCC repairs with 75 patients with 43-month follow-up demonstrated a general improvement in grip strength, range of motion, and MMWS (6.5 points) but no difference between the 2 cohorts.³⁶ A second prospective study compared open and arthroscopic TFCC repairs in 49 patients with 31-month follow-up.⁴⁸ Both groups demonstrated improvement in MMWS, DASH, and patient-related wrist/hand evaluation scores, but there was no difference between open and arthroscopic techniques. Only female sex and nonoperative technique, was significant for a risk of reoperation (17%). In addition to the comparative studies, one systematic review⁴⁹ has compared open and arthroscopic techniques; however, only the 2 aforementioned prospective studies with 124 patients were included.^36,48 While the subjective outcomes were comparable to reported retrospective case series, the complication rates from the 2 prospective studies are notably high for both open and arthroscopic techniques, including DSBUN irritation or neuroma (36% and 22%³⁶; 0% and 0%⁴⁸), ECU tendonitis (26% and 11%³⁶), persistent DRUJ instability (21% and 14%³⁶; 17% and 4%⁴⁸), and reoperation (28% and 25%³⁶; 13% and 4%⁴⁸).

In the only case series of 16 patients with 31-month follow-up using a knotless arthroscopic-assisted single transosseous tunnel TFCC repair technique, the authors reported excellent subjective outcome scores with 100% full return to work.⁵⁰ In addition, there were no complications reported. It is possible that the less prominent knotless technique reduces implant morbidity.

Complications

Arthroscopic techniques have reported a number of complications to include DSBUN irritation or neuroma (4%-36%^22,31,36), prominent suture knot (18%-27%^32,35,36), ECU tendonitis (11%-26%^36,48), persistent DRUJ instability (8%-18%^22,35,36,48), and severe pain (3%-12%^37,42). A new knotless transosseous technique has been described^38-40 and may limit DSBUN and knot-related irritation, but there are limited outcome data reported with this technique.

Conclusion

Tears of the TFCC may be repaired with several open and arthroscopic techniques. While nonoperative management may be first attempted, timely surgical intervention should be considered when patients fail nonoperative management with persistent pain or instability or in patients with high physical demands. Following surgical repair, excellent functional outcomes are obtained by most patients. However, long-term follow-up and outcomes in high-demand patients and results of knotless arthroscopic techniques are lacking and should be the direction of future analysis.