BONE GRAFTS AND CHRONIC OSTEOMYELITIS

Chronic osteomyelitis still remains a problem despite advances in medicine. Modern trends emphasise the ischaemia rather than the infection ofthe bone (Clawson and Dunn 1967). Avascular bone or scar tissue acts as an impenetrable barrier to antibiotics. For antibiotics to be effective dead bone, scar tissue and sinuses must be removed. All dead space must be eliminated when the wound is closed, otherwise the cavity is easily reinfected (Hazlett 1954; Valls, Brewener and Segers 1959; Clawson and Stevenson 1965). The removal of sequestra and scar tissue is usually done without difficulty, although from time to time the surgeon has to be less radical, lest the bone be unduly weakened (Horwitz and Lambert 1946, Reynolds and Zaepfel 1948). Elimination of the dead space is the more difficult procedure (Bickel, Bateman and Johnson 1953; Rowling 1959; Rowe and Sakellarides 1961 ; Mercer and Duthie 1964). It has long been known that osteomyelitic cavities have a poor tendency to spontaneous obliteration by bone proliferation (Hogeman 1949). Ingenuity has resulted in a multiplicity of techniques. At present only three deserve interest : the free skin graft, the muscle flap and the bone graft (Hazlett 1954, Rowe and Sakellarides 1961, Mercer and Duthie 1964, Winter and Papp 1964, Evans and Davies 1969). The first two present technical difficulties that make them impracticable in many cases. Above all in the metaphysio-epiphysial regions difficulties are frequent (Bickel and colleagues 1953, Martini and Essafi 1965, Evans and Davies 1969). In these cases saucerisation is usually impracticable. On the other hand, in regions such as the knee, ankle, wrist and shoulder it is difficult, or even impossible, to find muscle to fill the cavity (Coleman, Bateman, Dale and Starr 1946; Bickel and colleagues 1953). That is the reason why, when localised in one of those regions, chronic osteomyelitis continues to be a “therapeutic challenge” (Clawson and Dunn 1967). The use of bone grafts, not universally accepted, seems to present many advantages (Bickel and colleagues 1953, Hazlett 1954). Their use in infected bone defects has been condemned since the beginning of the century after early failures (Hogeman 1949, Buchman and Blair 195 1 ). The accepted practice was to wait one or even two years after the end of suppuration before grafts were used. With the advent of antibiotics only the period of waiting was changed (Boyd and Lipinski 1960, Judet and Judet 1965). The general idea of the necessary conditions of the “ground”, so that the graft takes, persisted in spite of the protection of antibiotics (Hogeman 1949, Stringa 1958). Even with occasional good results the procedure seemed inconsistent with the basic principles of biology, “living transplant being unable to survive in an infected cavity” (Winter 1951). Mowlem, of England, fighting against this opinion, and believing in protection by antibiotics, was the first to use bone grafts in infected cavities. In his papers (1944 and 1945) he emphasised the great resistance of cancellous bone chips to infection and the advantage of their use in reconstructive surgery of the skeleton. In conclusion, Mowlem said : “Nobody suggests that it is desirable to graft in the presence of infection. But it is our feeling that the existence of a low-grade infection did not represent a barrier to the graft. If the graft can be used before disuse atrophy of the limb, not only is much time saved, but also the possibilities of complete recuperation are greater. ” In subsequent years other authors have shown their