Clinical Features and Classification of Proximal Carpal Fracture Dislocation Through the Radiocarpal Joint

Background: The most common types of wrist dislocation are trans-scaphoid lunate dislocation (TLD) and trans-scaphoid perilunate dislocation, in which the lunate and proximal scaphoid are dislocated through the midcarpal joint. There is another rare type of dislocation in which the proximal carpi are dislocated through the radiocarpal joint. The purpose of this study is to examine the clinical features of this type of dislocation. Methods: Six cases of the proximal carpal fracture dislocation via the radiocarpal joint were retrospectively reviewed. All patients underwent open reduction and internal fixation with the ligament reconstruction. A Mayo wrist score was assigned to each patient based on the assessment of pain, functional status, range of motion and grip strength at the last follow-up. Clinical subjective evaluation of function and pain was assessed using the patient-rated wrist evaluation (PRWE) method. Results: All patients were male and injured with a median age of 33.5 years. The median follow-up period was 10 months. There were three types of dislocations: Scaphoid fracture dislocation, TLD and scaphoid-lunate dislocation. All patients had satisfactory results with an average PRWE of 7.2 ± 4.7. The preoperative VAS was 6.7 ± 1.0 and the postoperative VAS was 0.7 ± 0.7 (p < 0.01). Postoperative grip strength accounted for 89.2% ± 9.8% of the contralateral side; the Mayo wrist score averaged 90.0 ± 6.5, with four patients obtaining excellent and two good results. Conclusions: Fracture dislocation of the proximal carpal bones through the radiocarpal joint is an independent type of wrist dislocation that tends to occur in young men with high-energy impact. The wrist is most often injured in a pronation hyperextension position. If treatment is timely and appropriate, the prognosis is quite good. Level of Evidence: Level IV (Therapeutic).