Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA–viral peptide interaction as the major factor modulating durable control of HIV infection.

The natural history of primary anterior dislocation of the glenohumeral joint in adolescent patients remains unclear and there is no consensus for management of these patients. The objectives of this study were to report the natural history of primary anterior dislocation of the glenohumeral joint in adolescent patients and to identify the risk factors for recurrent dislocation. We reviewed prospectively-collected clinical and radiological data on 133 adolescent patients diagnosed with a primary anterior dislocation of the glenohumeral joint who had been managed non-operatively at our hospital between 1996 and 2008. There were 115 male (86.5%) and 18 female patients (13.5%) with a mean age of 16.3 years (13 to 18) and a mean follow-up of 95.2 months (1 to 215). During follow-up, 102 (absolute incidence of 76.7%) patients had a recurrent dislocation. The median interval between primary and recurrent dislocation was ten months (95% CI 7.4 to 12.6). Applying survival analysis the likelihood of having a stable shoulder one year after the initial injury was 59% (95% CI 51.2 to 66.8), 38% (95% CI 30.2 to 45.8%) after two years, 21% (95% CI 13.2 to 28.8) after five years, and 7% (95% CI 1.1 to 12.9) after ten years. Neither age nor gender significantly predicted recurrent dislocation during follow-up. We conclude that adolescent patients with a primary anterior dislocation of the glenohumeral joint have a high rate of recurrent dislocation, which usually occurs within two years of their initial injury: these patients should be considered for early operative stabilisation.

Introduction Although total knee arthroplasty (TKA) is an index procedure for orthopaedic registrars, there is a lack of published research as to the effects of surgery when performed by supervised trainees. The aim of this study was to compare functional outcomes up to five years after primary TKA performed by consultants and trainee surgeons. Methods A retrospective analysis was conducted of prospectively collected data for 609 consecutive patients (339 female, 270 male) undergoing TKA. Patients were assessed preoperatively as well as at 18 months, three years and five years postoperatively, and American Knee Society objective knee and functional scores (AKSK and AKSF) were recorded. Results Surgery was performed by a consultant in 465 cases and a supervised trainee in 144 cases. There were no significant differences between the two groups in preoperative patient characteristics, operative time (p=0.15), transfusion rates (p=0.84), length of stay (p=0.98), manipulation under anaesthesia (p=0.69), or mortality rates at one year (p=0.73) or five years (p=0.81). Postoperatively, the median magnitude of improvement in AKSK (48 points for consultant group vs 45 points for trainee group, p=0.74) and in AKSF (both groups 15, p=0.995) was similar between the groups. AKSK and AKSF scores were similar at all timepoints up to five years following surgery, and there was no difference in the median range of motion (both groups 100°, IQR: 18°) at five years (p=0.43). Conclusions TKA performed by supervised registrars gives functional outcomes that are equivalent to consultant performed TKA, without affecting postoperative range of movement, or increasing operative time, length of stay or transfusion rates. Rates of postoperative MUA and mortality are also comparable.

Case: A 52-year-old man underwent right total hip replacement with a 32-mm BIOLOX delta ceramic head with a polyethylene liner. At 8 months, he fell onto his right hip. Radiographs at the time were unremarkable. One month later, he noticed a sharp pain and a sensation of grinding in his right hip; radiographs of the hip showed a fracture of the ceramic head. Conclusions: This case further demonstrates that fourth-generation ceramic heads can fracture, and delays in catastrophic failure of ceramics in total hip arthroplasty (THA) following trauma may be secondary to the “slow crack growth” hypothesis.

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