Estimated cumulative X-ray exposure and additional cancer risk during the evaluation and treatment of scoliosis in children and young people requiring surgery.

INTRODUCTION: Clinicians and patients must weigh the benefits of radiological imaging against the risks of radiation exposure in the diagnosis and treatment of scoliosis. This report aims to estimate the cumulative absorbed and equivalent dose of radiation in patients undergoing surgical treatment for scoliosis, and to present this as an estimated risk of cancer compared to background radiation levels. METHODS: Retrospective review of estimated absorbed dose on the Computerised Radiology Information System (CRIS®). Patients undergoing surgical correction of scoliosis (age ≤ 25) from August 2010 to August 2015 investigated. Estimated absorbed dose [milligrays (mGy)] recorded. Pedicle screws inserted using image intensification. Equivalent dose [millisieverts (mSv)] and additional cancer risk calculated from the National Research Council document 'Health risks from exposure to low levels of ionising radiation' (2006). RESULTS: 271 patients identified. Mean age 15 (range 2-25). Mean total absorbed dose 2136 mGy [standard deviation (SD) 1700 mGy]. Mean number of plain spine radiographs was 8 (SD 3) with total 1884 mGy exposure (SD 1609 mGy). Additional dose provided by CT (mean 0.17 episodes), plain chest and abdominal radiographs and image intensification. Mean number of image intensification episodes was 1.1 with mean estimated exposure 180 mGy (SD 238 mGy). Image intensification accounted for 8% of the estimated absorbed dose during treatment. Estimated mean effective dose delivered was 20.952 mSv equating to an additional cancer risk of 0.27-0.45%. CONCLUSION: Additional cancer risk from cumulative imaging is small and equivalent to approximately 8 years of natural background radiation. Use of image intensification for pedicle screw insertion is a minor contribution (8%) to the total patient dose.

PTPN22 gene polymorphisms in autoimmune diseases with special reference to systemic lupus erythematosus disease susceptibility.

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease. SLE is a result of one or more immune mechanisms, like autoantibody production, complement activation, multiple inflammation and immune complex deposition leading to organ tissue damage. SLE affected patients are susceptible to common and opportunistic infections. There are several reports suggesting that Mycobacterium tuberculosis infection precipitates SLE in patients from endemic areas. Genetic factors and environmental factors also play an important role in the overall susceptibility to SLE pathophysiology. Recently, protein tyrosine phosphatase, non-receptor type 22 (PTPN22) gene, has been found to be associated with several autoimmune diseases like SLE, Grave's disease and Hashimoto thyroiditis. The missense R620W polymorphism, rs 2476601, in PTPN22 gene at the nucleotide 1858 in codon 620 (620Arg > Trp) has been associated with autoimmune diseases. The PTPN22 locus is also found to be responsible for development of pulmonary tuberculosis in certain populations. The PTPN22 1858C/T gene locus will be ideal to look for SLE susceptibility to tuberculosis in the Indian population. In this review, we focus on human PTPN22 gene structure and function as well as the association of PTPN22 gene polymorphisms with SLE susceptibility.

Hoffa fracture: fixation using headless compression screws.

INTRODUCTION: Hoffa fractures are uni- or bicondylar fractures of the distal femur in a coronal tangential plane. CASE PRESENTATION: We report the case of an isolated, low energy, closed, displaced, lateral femoral condyle Hoffa fracture in a 54 year old Caucasian man. This was treated by open reduction and internal fixation using two headless compression screws. At 1 year review the patient was pain free, the fracture had radiographically united and there was a range of movement to his knee of 0°-100°. DISCUSSION: Traditional methods of fixation for Hoffa fractures have led either to the application of complicated constructs attempting to achieve stability, or to large articular surface defects created whilst countersinking headed lag screws. Both have negative implications for the patient. We describe a novel method, not previously described in the literature, using screws in a posterior to anterior direction. This provides compression perpendicular to the fracture site whilst protecting against shear and torsional forces, thereby providing more stable fixation. Furthermore, our method allows for a minimally invasive approach and uses headless compression screws, which reduces the chance of damage to the articular surface and is, therefore, less physiologically invasive.