Concomitant Pyomyositis, Osteomyelitis and Pathologic Fracture of The Distal Femur. A Case Report

INTRODUCTION

Pyomyositis is a purulent skeletal muscle infection that arises from hematogenous dissemination and is usually accompanied by abscess formation. [53] The definition of osteomyelitis is generally accepted as an inflammatory process of bone and bone marrow caused by an infectious organism(s) which results in local bone destruction, necrosis and apposition of new bone. The concomitant presence of pyomyositis (PYM), osteomyelitis (OM) and a septic pathologic fracture of the associated femur is rare. This situation presents challenges because the treatment may be staged and customized. Management of PYM heavily depends on the stage it is first diagnosed.

The Cierny-Mader classification is a clinical system that categorizes osteomyelitis based on its anatomical, clinical, and radiological characteristics. It divides osteomyelitis into four stages. In stage 1, known as medullary, the infection is limited to the medullary cavity of the bone. Stage 2, referred to as superficial, affects only the cortical bone and typically stems from direct inoculation or contiguous focus infection. Stage 3, termed localized, typically affects both cortical and medullary bone but doesn’t compromise the entire bone diameter, with the bone generally remaining stable. Stage 4, called diffuse, involves the complete thickness of the bone and results in loss of stability, resembling infected nonunion. [59]

Some patients are diagnosed well beyond the first stagedespite extensive tests. Targeted therapyfor OM and the pathologic fracture by an antibiotic cement-coated nail (ACCN) using a cheaper core Kuntscher nail (K-nail) is historically associated with differing antibiotic combinations, timing of removal of the ACCN and up to 40% persistence of infection. [3,15,17,28,37,38,41]

Here we present a case report of concomitant pyomyositis, osteomyelitis and closed pathologic femoral fracture managed with an ACCN using a core K-nail.