A sinall proportion of fractures progress to non-union. Non-uiiioiis are routinely classified into two groups either hypertrophic or atrophic according to their radiological appearance. It is a coiiimon preconception that non-unions with a hypertrophic appearance on X-ray are biologically active and vascular with potential to heal given the correct stable environment. Atrophic nonunions are considered to be avascular aiid inert and will not heal even under the correct stable environment. Non-unions are either infected or aseptic. I n the present study, we tested the liypothesis that aseptic atrophic tion-uiiioiis are less vascular than aseptic hypertrophic lion-unions aiid healing fractures. Biopsies were taken from the fracture gap of patients with healing fractures. hypertrophic lion-unions aiid atrophic non-unions. A dual labelling technique was used with antibodies against CD3 1 (JC70) and Collagen IV. Blood vessels were quantified using a Chalkley point eyepiece graticule. There was no statistically significant difference in the median vessel count between the three fracture groups. These findings do not support tlie hypothesis that established atrophic fracture non-union are less vascular than hypertrophic non-unions or healing fractures.

The results of arthroscopic debridement and loose body retrieval for osteochondritis dissecans (OCD) of the capitellum in 29 symptomatic patients who had failed conservative management are described. There were no complications of surgery. At an average of 77 months after operation the majority of patients had mild or no pain but with some discomfort during heavy lifting and sport. All were capable of performing simple activities of daily living, and all but one had good or excellent outcomes and rated their satisfaction highly. Only 4 of 27 patients had to give up their preferred sport because of persistent elbow problems. Thirty-eight percent of patients had recurrence of locking or catching, although these symptoms were described as better than the condition before operation and none wanted further surgical intervention. It is concluded that arthroscopic debridement and removal of loose bodies is a safe and reliable procedure for patients with persistent symptoms from OCD of the capitellum.

Our aim was to develop a clinically relevant model of atrophic nonunion in the rat to test the hypothesis that the vessel density of atrophic nonunion reaches that of normal healing bone, but at a later time-point. Atrophic nonunion is usually attributed to impaired blood supply and is poorly understood. We determined the number of blood vessels at the site of an osteotomy using immunolocalisation techniques in both normally healing bones and in atrophic nonunion. At one week after operation there were significantly fewer blood vessels in the nonunion group than in the healing group. By eight weeks, the number in the atrophic nonunion group had reached the same level as that in the healing group. Our findings suggest that the number of blood vessels in atrophic nonunion reaches the same level as that in healing bone, but at a later time-point. Diminished vascularity within the first three weeks, but not at a later time-point, may prevent fractures from uniting.