Brunelli’s Tenodesis

Fig. 1

SLAC wrist with dorsal flexion of the lunate (left), palmar flexion and dorsal subluxation of the proximal pole of the scaphoid (centre) and SL diastasis (right). Note the presence of radioscaphoid and lunocapitate chondral lesions

Experimentally, the isolated section of the SL membrane in a cadaveric wrist does not cause any kinematic alteration [3], except in some special radioscaphoid morphotypes [21]. Distal radius fractures are frequently complicated by intrinsic wrist ligament lesions, especially affecting the SL membrane, yet SLAC wrist is a rare occurrence after distal radius fractures. In fact, the SL ligament may have more a proprioceptive than a mechanical role [9]. As early as 1989, Jantea believed that the said SL dissociative instability resulted initially from insufficiency of the ligaments stabilizing the distal pole of the scaphoid at the scaphotrapeziotrapezoid (STT) level, followed by distension and ultimately secondary rupture of the SL ligament (Jantea C., Mayo Clinic, Rochester, MN, USA, 1989, Personal communication). Brunelli considered the deep part of the flexor carpi radialis (FCR) sheath to be the principle stabilizer of the STT complex [2]. Garcia-Elias believed that the primary stabilizer of the scaphoid was the SL ligament, especially its dorsal component, the STT ligament complex and the scaphocapitate and radioscaphocapitate ligaments being secondary stabilizers [7]. Short reported that the secondary stabilizers were the scaphocapitate and scaphotrapezial ligaments [16, 17].

It is worthy of note that the term instability is incorrect; in fact, the new equilibrium reached in a fixed DISI deformity is quite stable and thus difficult to correct. We proposed in 1996 the term ‘carpal dyskinetic syndrome’ [14]. Garcia-Elias defined carpal instability as carpal kinetic dysfunction (load transmission) and/or dyskinematic (osseous alignment), but proposed keeping the term instability by right of use [7].

The results of repair of chronic SL lesions remain disappointing, probably owing to the difficulty of correcting scaphoid malposition by these reconstructions. We have abandoned our 1995 original technique of SL repair using a vascularized transfer of the interosseous membrane [13, 15], when in 1995 Brunelli described his technique of ligamentoplasty where a band of the FCR tendon, still attached to the second metacarpal, is tunnelled through the distal pole of the scaphoid and anchored to the dorso-ulnar radius, thereby reducing the pathological scaphoid flexion, the dorsal subluxation of the proximal pole as well as the SL diastasis (Fig. 2). The lunate dorsiflexion tends to autocorrect spontaneously, following scaphoid reduction [2, 3].

Fig. 2

The Brunelli’s tenodesis using a band of the FCR tendon

2 Surgical Technique

The surgery is usually performed under regional anaesthesia. We like the approach through a dorsal radio-scapho-lunate incision parallel to the distal rim of the radius [6]. The dorsal sensory radial nerve branches are identified and spared. The third compartment is incised and the extensor pollicis longus (EPL) tendon palmarly retracted. It is usually unnecessary to open the fourth compartment; it can be ‘en bloc’ dissected off the distal radius over several millimetres. The dissection proceeds on either side of the extensors carpi radialis, taking care not to damage distally the radial pedicle. The ligament lesions are thus exposed. There is usually an abnormal diastasis between the scaphoid and lunate, with extensive synovitis. There is often little left of the SL ligament, and any attempt at its direct suture is doomed to fail. There is evident dorsal subluxation of the proximal pole of the scaphoid, and the lunate, in DISI, is practically invisible under the capitate head which is situated very close to the radius glenoid. The SL synovitis is resected. Distally, the surgeon approaches the STT interval, which is not so easy to open due to the scaphoid malposition; the synovitis present at this level is as well resected. The reducibility of the scaphoid is now evaluated. A second 4-cm incision is then made along the FCR, centred over the scaphoid tubercle, easily palpable due to the malposition of that bone. The tendon sheath is opened, dividing some thenar muscle fibres. Through another transverse incision, 7 cm higher, a third (about one-half according to Brunelli [2]) of the FCR tendon is harvested, preserving its distal attachment to the trapezium, trapezoid and second metacarpal. At this level, the tendon sheath is not opened. The STT joint is approached, and a spatula is introduced in this joint, giving its orientation. A 2.8- or 3.2-mm tunnel is made through the distal pole of the scaphoid, parallel to this joint, and the tendon band is passed through it. By pulling on the ligamentoplasty, one can usually observe the ‘automatic’ reduction of the scaphoid and lunatum with disappearance of the SL diastasis. If this is not the case, the surgeon can use K-wires temporarily inserted in both bones as ‘joysticks’ to assist the reduction. The scaphoid is fixed in the reduced position using one scaphocapitate K-wire; in many cases, a second K-wire is used to transfix the SL joint. The wires are bent and buried subcutaneously. The tendon graft is fixed under tension using an anchor in the distal radius, at the floor of the third compartment. After meticulous capsular closure, the EPL is left subcutaneous. The wire(s) is(are) removed as a secondary minor procedure, after 6 weeks of immobilization in a plaster cast. Physiotherapy is then instituted. Return to heavy manual work is not allowed before 3 months, and return to high-level sports before 6 months.

3 Results

In his original 1995 publications, Brunelli reported 11 and then 13 cases of satisfactory reduction of the scaphoid and of the lunate, with restoration of the carpal height, the results being maintained over time (follow-up between 6 months and 2 years [2, 3]). Other publications reported results using modifications of the original Brunelli technique [4, 5, 8, 11, 12, 18].

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