252 Diseases of Bone. 



(b. ) Where the dead piece has become loose, but has remained in position, 

 and has acted as a source of irritation. 



6. 115. Acute Suppurative Osteo-myelitis of the Femur- 

 Necrosis, Fracture. — Lower half of the right femur of a 

 lad, aged 18 — macerated, to show the above. 



Three years before amputation a large abscess formed in the patient's 

 right thigh. This was opened, but had continued to discharge for six 

 months, when he fell and fractured the affected femur. Union took place, 

 but at an obtuse angle, and the previous discharge of matter continued. 

 A probe when passed into the opening came in contact with bone, but no 

 loose portion could be discovered previous to the amputation. This 

 difficulty was afterwards explained when it was found that the sequestrum 

 had been covered posteriorly by a mass of semi-cartilaginous substance 

 fully an inch in depth, which occupied the popliteal space, and was 

 distinctly continuous with the thickened periosteum. 



At the back of the preparation there is a large sequestrum, 

 loose, but partially surrounded by the neighbouring new shell. 

 The lower end of the shaft, which is for the most part of new 

 formation, is curved forwards just in front of the sequestrum. 

 The latter has evidently been pressing against the bone above 

 and below the bend, and thus must have acted mechanically in 

 preventing the bend from increasing. The surface of the new 

 shell blends with the original bone at the knee and towards the 

 middle of the shaft. G. C. 2111. 



Presented by Benjamin Bell, F.R.C.S.E., 1840. 



6. 116. Acute Suppurative Osteo-myelitis of the Femur- 

 Necrosis, Anchylosis of the Knee, and Atrophy of the 

 Tibia. — Section of the lower end of a femur and upper end of 

 a tibia— macerated, to show the above. 



The patient, a young person, suffered about two years before amputa- 

 tion from acute suppuration and inflammation of the femur, which ended 

 in necrosis. He had not been treated, and had lain with his knee very 

 much flexed. Amputation was performed through the thigh by Pro- 

 fessor Annandale. 



The specimen shows a sequestrum in the femur, lying now 

 loose in a cavity, with considerable development of new bone 

 near and partially surrounding it. The new bone towards the 



