Proposal for a Radiological Classification System for Carpo-Metacarpal Joint Dislocations with or without Fractures.

Pundkare Gt,Deshpande Ss

doi:10.5704/moj.1807.008

Abstract

Introduction: Though complex injuries like CarpoMetacarpal (CMC) Joint dislocations represent only 1% of all hand injuries, they have disabling impact on the functional status of patient. There are no reports in the literature classifying disabling complex injuries like CMC joint dislocations presumably because of low incidence. We propose a new classification through retrospective analysis of patients, along with literature search.Materials and Methods: A new classification system has been proposed and designed at our clinical unit and applied to eight patients with CMC joint dislocations. All patients were treated with open reduction with Kirschner wire fixation. At follow-up all these patients were analysed for radiographic assessments and functional scores.Results: The proposed classification identifies three types of dislocations and an additional complex category to supplement any basic type. The direction of dislocation describes the types as Type A: Dorsal, Type B: Volar and Type C: Divergent. Among the eight patients in our study, we had two of Type A, two Type B, three Type B.1, one Type C. 1. These patients had average follow-up of 18 months. The quick DASH score improved from 75.76 at 6 weeks to 1.9 at 18 months. We also did intra-observer and inter-observer reliability which scored 1.Conclusion: Our proposal is a reproducible, simple, comprehensive and practical classification, easily remembered and communicated among colleagues. It is clinically relevant as it helps us in planning surgical management and prognostic evaluation.

Highlights

Though complex injuries like CarpoMetacarpal (CMC) Joint dislocations represent only 1% of all hand injuries, they have disabling impact on the functional status of patient
A direct force applied on the palmer aspect of the metacarpal bases will cause dorsal dislocation which is in the direction of the force A direct force applied on the dorsal aspect of the metacarpal bases will push the metacarpals to the volar side, which is in the direction of the force causing volar dislocation The mechanism here is quite complex involving twisting and rotatory forces
The divergence group had improved in the DASH score but had prolonged recovery

Summary

INTRODUCTION

Carpo-Metacarpal Joint (CMC) dislocations with or without associated fractures are not commonly encountered and represent 1% of all hand injuries[1]. Though the percentage is small these injuries are complex and have the potential for long term limitations or disabilities. When the CMC injuries are part of the poly-trauma injury complex the treatment is often delayed or missed in the process of attention to grave or major injuries. There have been many case reports and a few small series in the literature but no classification has been suggested, presumably because of the low incidence of this injury. The classification system proposed and developed by us is clinically relevant, based on commonly available investigation like radiographs, reproducible, easy to remember and apply in the management of these injuries. The classification, by detailing the indicator points, will help in those areas in which the surgeon may fail to notice the injury

MATERIALS AND METHODS

RESULTS

DISCUSSION