Scapholunate and perilunate injuries in the athlete

PURPOSE OF THE REVIEW

Scapholunate and perilunate injuries can be difficult to diagnose and treat in the athlete. In this review article, we present the mechanism of injury, evaluation, management, and outcomes of treatment for these injuries.

RECENT FINDINGS

Acute repair of dynamic scapholunate ligament injuries remains the gold standard, but judicious use of a wrist splint can be considered for the elite athlete who is in season. The treatment of static scapholunate ligament injury remains controversial. Newer SL reconstructive techniques that aim to restore scapholunate function without compromising wrist mobility as much as tenodesis procedures show promise in athlete patients. Acute injuries to the scapholunate ligament are best treated aggressively in order to prevent the sequelae of wrist arthritis associated with long-standing ligamentous injury. Acute repair is favored. Reconstructive surgical procedures to manage chronic scapholunate injury remain inferior to acute repair. The treatment of lunotriquetral ligament injuries is not well defined.

Chronic scapholunate instability treated with temporary screw fixation

PURPOSE

To determine the efficacy of scapholunate (SL) temporary screw fixation to maintain the reduction of SL interval after ligament debridement, repair, or reconstruction.

METHODS

A total of 36 patients who had chronic SL instability were included. Arthroscopic debridement was performed for dynamic instability, and primary repair or reconstruction of the SL ligament was performed for static instability. We then used SL screw fixation for the protection of the repair or reconstruction. Screws were removed when loosening was noted on x-ray.

RESULTS

The average patient age was 43 years. Eleven had dynamic instability, and 25 had static instability. The average follow-up was 7.9 years. Nearly 95% of the patients had no more than mild pain. The average ranges of movement of the wrist were 55° extension, 51° flexion, 26° ulnar deviation, and 15° radial deviation. Postoperative x-ray revealed an average SL angle of 56°. The average SL gap was 2.5 mm. Both of these radiographic parameters were maintained at final follow-up. Dorsal intercalated segmental instability (DISI) deformity was not corrected in 2 patients. One patient had avascular changes in the proximal scaphoid and lunate but remained asymptomatic at 7 years postoperatively. There was no further intercarpal and radiocarpal degeneration.

CONCLUSIONS

Temporary SL screw fixation together with arthroscopic debridement, ligament repair, or reconstruction provided a stable closure of the SL interval and satisfactory clinical and functional results along with a low incidence of complication.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The path of screw insertion for stabilization of the scapholunate joint: a cadaveric study

The aim of this study was to determine the path of screw placement to avoid breaching the articular surface of both lunate and scaphoid bones at the radiocarpal and midcarpal joints. An Acutrak screw was inserted into the right scapholunate joint of ten cadavers starting immediately distal to the tip of the radial styloid and aiming for the tip of the ulnar styloid. The articular surfaces of the scaphoid and lunate bones in all ten cadavers were exposed and examined. A computed tomography (CT) scan of four wrists was performed. Eight of the ten cadavers had no perforation or destruction of the articular surfaces. Screw stabilization of the scapholunate joint can be performed without perforation or destruction of the lunate or scaphoid surfaces. We recommend that if this form of fixation is being used then the screw should be inserted commencing at the radial styloid tip and aiming for ulnar styloid tip, under radiological guidance.

Poor results of radio-scaphoid capsulodesis for scapholunate dissociation

We reviewed 17 patients 64 (range 29-123) months after dorsal radioscaphoid capsulodesis for scapholunate dissociation. Mean loss of key pinch was 13%, grip strength 18%, wrist flexion 22% (p < 0.001), and total wrist ROM 17% (p < 0.005). VAS (0 = best; 100 = worst) was 30(±28) for pain, 43(±30) for function, and 33(±33) for general satisfaction with the outcome. Mean Quick-DASH and PRWE scores were 27 and 34, respectively. The mean scapholunate gap was 3.5 mm before surgery, 1.9 mm after surgery, and 3.3 mm at review. The corresponding scapholunate angles were 63°, 46°, and 70°, respectively. The mean radioscaphoid angle with the wrist maximally flexed was 84° (69-99) for the patients and was 91° (77-103) in ten wrists of volunteers. Six patients had changed their jobs because of the wrist. Three patients stated that they would not have consented to operation if they had known the outcome in advance. Radioscaphoid capsulodesis does not prevent volar flexion of the scaphoid.

The use of screws in the treatment of scapholunate instability

Seven patients with chronic scapholunate instability (Geissler grade 2-4) were treated by percutaneous placement of screws across the scapholunate joint after arthroscopic debridement of the remnants of the scapholunate ligament. In all seven cases, the screw caused partial destruction of the lunate and/or scaphoid requiring screw removal within 6 months. We no longer perform this procedure.

Scapholunate fusion in chronic symptomatic scapholunate instability

Since 1989 scapholunate fusion has been performed on 13 patients with chronic scapholunate instability causing debilitating symptoms. These cases were reviewed at a mean 93 (range, 60-132) months after surgery. Establishing whether bony fusion had been achieved proved extremely difficult even after CT scanning, but fusion was unequivocally achieved in four cases. Ten patients were subjectively satisfied with their treatment. Two patients who had no symptomatic improvement subsequently underwent total wrist arthrodesis. A method of fusing the scaphoid and lunate is described, though we accept that a firm fibrous union may be all that is achieved in most patients. However, this appears sufficient to restore stability with a high patient satisfaction.