Introduction: Osteoid Osteomas are not uncommon, benign bone tumours which have well-defined clinical, radiological and pathological characteristics. These tumours can potentially affect any bone in the body, but show a predilection for long tubular bones. The clinical presentation can easily be confusing, if the site in question is rare and the presentation atypical. Lesions occurring in the foot often pose particular problems in diagnosis, often leading to delays in treatment. Although there have been accounts of the post traumatic presentations of osteoid osteomas, no direct link has been established between trauma and its incidence.

Case Report: A 38 year old gentleman was referred by his GP with an eighteen month history of right midfoot pain after a football injury which forced his right foot into hyperextension and abduction. Initial radiographs after the injury were normal. The pain did not respond to non-steroidal anti-inflammatory drugs (NSAIDs) and there were no nocturnal exacerbations. Examination at presentation showed an antalgic gait with medial mid-foot tenderness centred over the first tarso-metatarsal joint (TMTJ). Repeat radiographs showed mild degenerative changes in the first TMTJ. A bone scan showed a hot spot over the right cuneiform bones. Subsequent computed tomography (CT) showed an osteoid osteoma, with a characteristic central calcific nucleus within the nidus, of the medial border of the lateral cuneiform bone. The osteoma was treated with en-bloc excision and the diagnosis was confirmed by histology.

Conclusion: Despite the advances in its treatment, osteoid osteoma of the foot can pose a difficult diagnostic puzzle. This condition should always be kept in mind when faced with persistent, post-traumatic foot pain, even in the absence of roentgenographic findings. In such cases a high index of suspicion and a low threshold for appropriate imaging can lead to the timely diagnosis and treatment of this tumour.

Introduction: Patellar alignment and tracking are very important to a successful surgical outcome in total knee arthroplasty (TKR) and difficult to assess in arthroscopies of the knee. The need for and use of a tourniquet in TKR’s and knee arthroscopies are debatable. One factor against its use is the possible alteration in the extensor mechanism dynamics making intraoperative assessment of patellofemoral (PF) tracking unreliable.

Aim: To assess whether an inflated tourniquet affects patellofemoral tracking.

Method: 10 Healthy male subjects, between 25 to 30 years of age, with no history of anterior knee pain; lower limb trauma, deformities or previous operations; or systemic disorders were admitted to the study. Dynamic sequence (Fast Field Echo scans) MRI scans over 57secs (flexed and extending against resistance to full extension), were performed without a tourniquet, on both knees, on all subjects as a control. A tourniquet, placed around the thigh, inflated to 300mmHg. Dynamic MRI scans were then obtained of each PF joint. PF tracking was then compared statistically.

Results: Of the 20 knees compared, sulcus and congruence angles were within normal limits. There was no significant difference in patellar tilt angle or patellar displacement. A trend of increased femoral external rotation was seen.

Conclusion: An inflated tourniquet placed around the upper thigh with the leg in extension does not alter patellofemoral kinematics in normal subjects. We believe the femoral external rotation seen is a mechanical adaptation of the tourniquet in the groin.