Supracondylar fractures of the humerus have historically been treated as an emergency case and operated on at the earliest opportunity. We undertook a study to examine whether surgical timing affects the need for open reduction or peri-operative complications in the type III injuries.

Between August 1995 and August 2004, 534 patients presented and were referred to our unit with these fractures. Those with closed, type III injuries without vascular compromise were selected (171 patients). These were divided into 2 groups: those undergoing surgery less than 8 hours from presentation (126 patients) and those undergoing surgery more than 8 hours from presentation (45 patients).

The two major differences between the two groups were: the delayed group were more likely to undergo open reduction (33.3% v 11.2%, p<0.05) and the mean length of the surgical procedure was increased (105.1 minutes v 69.2 minutes, p<0.05). Delay in treatment of the type III supracondylar fractures is associated with an increased need for open reduction and a longer procedure. We would recommend treating these injuries at the earliest opportunity.

If an arthroplasty patient presents with wound breakdown, sinus formation or a hot, red joint the diagnosis of infection is straightforward. However, most total joint replacement (TJR) infections are difficult to distinguish from aseptic loosening. It is imperative to know if a painful TJR is infected to plan appropriate management.

In this prospective study of 204 patients we analysed the diagnostic accuracy of various tests for infection: Inflammatory Markers (CRP/ESR); Aspiration Microbiology; and the Polymerase Chain Reaction (PCR) – a novel technique in this situation. We used international criteria as the gold standard for infection, applied at the time of revision surgery. Any of – a sinus; frank pus in the wound; positive intra-operative microbiology; positive histology – classified the patient as infected. The sensitivity (Sens), specificity (Spec), positive predictive value (PPV) and negative predictive value (NPV) of each test were calculated.

52 patients with an original diagnosis of inflammatory arthritis were excluded, as histology may be inaccurate. The results for the remaining 152 patients are: CRP > 20mg/l: Sens 77%; Spec 76%; PPV 49%; NPV 92%. ESR > 30 mm/hr: Sens 61%; Spec 86%; PPV 57%; NPV 87%. Aspiration Microbiology: Sens 80%; Spec 83%; PPV 71%; NPV 88%. PCR: Sens 71%; Spec 78%; PPV 43%; NPV 89%.

Few patients with negative CRP/ESR were found to be infected; if positive, there was a 50/50 chance that the joint was infected. Positive aspiration microbiology was associated with underlying infection 3 times out of every 4, and negative results were correct 9 times out of 10. PCR was no more accurate than existing tests.

All patients with painful TJR’s should have inflammatory markers checked – if negative the clinician can be relatively reassured that the implant is not infected. If positive or suspicion remains, further investigation should be undertaken. Joint aspiration for microbiology is currently the best available second line investigation.

Introduction If an arthroplasty patient presents with wound breakdown, sinus formation or a hot, red, painful joint replacement the diagnosis of infection is relatively straightforward. However, most total joint replacement (TJR) infections present in an indolent fashion and are impossible to distinguish from aseptic loosening. It is imperative to know if pain in a TJR is due to infection to plan appropriate further management.

Methods In this prospective study of 204 patients we analysed the diagnostic accuracy of various tests for infection in the setting of TJR: Inflammatory Markers (CRP/ESR); Aspiration Microbiology; and the Polymerase Chain Reaction (PCR) – a novel technique in this situation. We used internationally agreed criteria as the gold standard for infection. The patient was deemed to be infected if any of the following were found at the time of revision surgery: a sinus; frank pus in the wound; positive microbiology or positive histology on intra-operative specimens. The sensitivity (Sens), specificity (Spec), positive predictive value (PPV) and negative predictive value (NPV) of each test were calculated.

Results 52 patients with an original diagnosis of inflammatory arthritis were excluded, as histology may be inaccurate. Their results have been presented elsewhere. The results for the remaining 152 patients are: CRP > 20mg/l: Sens 77%; Spec 76%; PPV 49%; NPV 92%. ESR > 30 mm/hr: Sens 61%; Spec 86%; PPV 57%; NPV 87%. Aspiration Microbiology: Sens 80%; Spec 83%; PPV 71%; NPV 88%. PCR: Sens 71%; Spec 78%; PPV 43%; NPV 89%.

Findings and Conclusions Only a few of the patients with negative inflammatory markers later turned out to be infected. If the inflammatory markers were positive, there was roughly a 50/50 chance that the joint was infected. Positive aspiration microbiology was associated with underlying infection approximately 3 times out of every 4, and negative results were correct 9 times out of 10. PCR was no more accurate than existing tests.

We recommend that all patients with painful TJRs have inflammatory markers checked as a screening test – if negative then the clinician can be relatively reassured that the implant is not infected. If positive, further investigation should be undertaken. Joint aspiration for microbiology is currently the best available second line investigation.

We have investigated the effect of currents induced by electromagnetic fields on the healing of the tibia of sheep after osteotomy, using objective and quantifiable criteria wherever possible. A battery-powered, induction apparatus was developed and was enclosed within the cast applied to the limb, so that the treated fractures received pulsed magnetic fields for 24 hours a day while the animals were freely mobile. In all, 13 sheep were treated and 13 were used as controls. The response was assessed by radiography of the limb and of the excised bone, by histology, including measurement of the areas of callus, fibrocallus and cortical bone, and by measurement of the uptake and extraction of bone-seeking mineral. All the bones healed and no statistically significant differences between the treated animals and the controls were discovered except (at only P less than 0.05) in the uptake of bone-seeking mineral; this increased more rapidly in treated animals over the two to three weeks after osteotomy, although at six weeks the uptake in both groups was the same.