Comments on Kailu et al.: Chronic perilunate dislocations treated with open reduction and internal fixation: results of medium term follow-up

Abstract

Sir We read with interest the article titled “Chronic perilunate dislocations treated with open reduction and internal fixation: results of medium term follow-up” by Kailu et al. [1]. The authors have reported favourable results with open reduction and internal fixation in neglected perilunate dislocations, despite the difficulty of reducing delayed cases. However, we were intrigued by the authors’ assessment of the severity of ligamentous injury at surgery using the Geissler classification system [2]. This classification was originally described to differentiate various grades of ligament disruptions in association with distal radius fractures; it is an arthroscopic grading system [2], which determines carpal instability using wrist arthroscopy. The reported series is that of unreduced perilunate dislocations (PLD), where the nature of the injury is such that frank ligament disruptions occur, and ligament ends may not be identifiable after treatment delays. In a trans-scaphoid perilunate dislocation, the luno-triquetral ligament must tear completely to allow the triquetrum to dislocate dorsally along with the rest of the carpus (Mayfield stage III) [3]. Thus grades 1, 2 and 3 of Geissler classification automatically do not apply to the luno-triquetral ligament. Additionally, scapholunate disruption would be complete if there were no scaphoid fracture, and could not occur if there is a scaphoid fracture [3]. The importance of this method of classification becomes redundant in this scenario. The authors have also emphasised the need to repair the luno-triquetral ligament in patients with grade 3 and 4 injuries as per the Geissler system. However, only four out of their nine patients with trans-scaphoid perilunate dislocations (Table 2) underwent ligament repair, with more than 50% of cases not needing ligament repair. In the acute scenario, the luno-triquetral ligament needs repair after emergency reduction [4, 5]. In neglected perilunate dislocations, however, most of the literature is silent on the issue of ligament repair. Seigert et al. [6] performed ligament repair in only one out of six patients with chronic perilunate dislocations. It is also our experience over the last 12 years that significant fibrosis and scarring in chronic cases makes ligament identification difficult, and the extensive dissection required to reduce the dislocation further frustrates attempts at repair of retracted ligament ends. We have found that stabilisation of the luno-triquetral, capito-lunate and scapho-lunate joints with K-wires after reduction provides a satisfactory functional outcome in neglected perilunate dislocations. Nevertheless, we commend the authors on conducting this excellent study, and for the reiteration of the fact that in cases with associated cartilage damage the outcomes after open reduction are poor, and options including proximal row carpectomy should be kept in mind as alternative methods of treatment. Thanking you, Prof MS Dhillon, Dr Sharad Prabakar, Dr Kamal Bali