Stephen A. Brennan

Overuse ankle injuries in professional Irish dancers

BACKGROUND Overuse ankle injuries have been described in elite athletes and professional ballet dancers however the spectrum of injuries experienced by professional Irish dancers has not been defined. METHODS A troupe of actively performing dancers from an Irish-dance show were recruited (eight male, ten female; mean age, 26 years). The prevalence of overuse injuries in the right ankle was determined from magnetic resonance imaging. Foot and ankle self-report questionnaires were also completed (AOFAS and FAOS). RESULTS Only three ankles were considered radiologically normal. Achilles tendinopathy, usually insertional, was the most frequent observation (n=14) followed by plantar fasciitis (n=7), bone oedema (n=2) and calcaneocuboid joint degeneration (n=2). There were limited correlations between MRI patterns and clinical scores indicating that many conditions are sub-clinical. Dancers with ankle pain had poor low (p=0.004) and high (p=0.013) level function. CONCLUSIONS Overuse ankle injuries are common in Irish dancers. Incorporating eccentric exercises and plantar fascia stretching into a regular training program may benefit this population.

Assessment of a new undergraduate module in musculoskeletal medicine

BACKGROUND Despite the high prevalence of musculoskeletal disorders seen by primary care physicians, numerous studies have demonstrated deficiencies in the adequacy of musculoskeletal education at multiple stages of medical education. The aim of this study was to assess a newly developed module in musculoskeletal medicine for use at European undergraduate level (i.e., the medical-school level). METHODS A two-week module in musculoskeletal medicine was designed to cover common musculoskeletal disorders that are typically seen in primary care. The module incorporated an integrated approach, including core lectures, bedside clinical examination, and demonstration of basic practical procedures. A previously validated examination in musculoskeletal medicine was used to assess the cognitive knowledge of ninety-two students on completion of the module. A historical control group (seventy-two students) from a prior course was used for comparison. RESULTS The new module group (2009) performed significantly better than the historical (2006) control group in terms of score (62.3% versus 54.3%, respectively; p < 0.001) and pass rate (38.4% versus 12.5%, respectively; p = 0.0002). In a subgroup analysis of the new module group, students who enrolled in the graduate entry program (an accelerated four-year curriculum consisting of students who have already completed an undergraduate university degree) were more likely to perform better in terms of average score (72.2% versus 57%, respectively; p < 0.001) and pass rates (70.9% versus 21.4%, respectively; p < 0.001) compared with students who had enrolled via the traditional undergraduate route. In terms of satisfaction rates, the new module group reported a significantly higher satisfaction rate than that reported by the historical control group (63% versus 15%, respectively; p < 0.001). CONCLUSIONS In conclusion, the musculoskeletal module described in this paper represents an educational advance at undergraduate (i.e., medical-school) level as demonstrated by the improvement in scores in a validated examination. As pressure on medical curricula grows to accommodate advancing medical knowledge, it is important to continue to improve, assess, and consolidate the position of musculoskeletal medicine in contemporary medical education.

Dislocation of primary total hip arthroplasty and the risk of redislocation

6554 primary total hip arthroplasties were reviewed. Risk factors for dislocation were analysed to assess which were important in terms of predicting recurrent instability. The patients risk of having a second dislocation was independently associated with the surgical approach adopted (p = 0.03) and the time to first dislocation from the primary hip replacement (p = 0.002). Early dislocators whose surgery was performed through an anterolateral approach had less recurrence than late dislocators through a posterior or transtrochanteric approach. None of the other risk factors including head size (p = 0.59), modularity (p = 0.54), mechanism of dislocation (p = 0.23), leg length discrepancy (p = 0.69) and acetabular inclination (p = 0.31) were influential. The use of an abduction brace was not useful in preventing a further dislocation with 69.2% of those braced re-dislocating compared to 68.5% who were not braced (p = 0.96).

Superior pole sleeve fracture following patellar stabilisation

Sleeve fractures of the superior pole of the patella are rare. The importance of their diagnosis lies in the fact that the avulsed fragment contains a source of bone forming tissue which may lead to duplication or enlargement of the patella. We report a case in a 16 year old boy who underwent plication of the medial patellofemoral ligament, vastus medialis obliquus advancement and percutaneous lateral release, for recurrent instability. Interruption of the blood supply with subsequent avascular necrosis is one possible mechanism for this complication. Another more likely mechanism is that of failure of the repair and re-dislocation, which may have been contributed to by prolonged cast immobilization.

Tourniquets and exsanguinators: a potential source of infection in the orthopedic operating theater?

Background and purpose Fomites are increasingly being recognised as a source of hospital-acquired infection. We have therefore assessed tourniquets and exsanguinators for the presence of bacterial pathogens in 1 elective and 2 trauma orthopedic hospitals. Material and methods Swabs were taken prior to and after decontaminating these devices with 1 of 3 different cleaning modalities. These were then assessed for colony counts and organisms identified. Results Bacteria commonly implicated in surgical site infections such as coagulase-negative staphylococci, Staphylococcus aureus and Proteus spp. were prevalent. We also found a resistant strain of Acinetobacter and Candida. Exsanguinators were the most heavily contaminated devices, and colony counts in the trauma hospitals were up to 400% higher than in the elective hospital. Alcohol- and non-alcohol-based sterile wipes were both highly effective in decontaminating the devices. Interpretation Infectious organisms reside on the tourniquets and exsanguinators presently used in the orthopedic theater. These fomites may possibly be a source of surgical site infection. We have demonstrated a simple and effective means of decontaminating these devices between cases.

Effect of vibration on the shear strength of impacted bone graft in revision hip surgery

We developed a method of applying vibration to the impaction bone grafting process and assessed its effect on the mechanical properties of the impacted graft. Washed morsellised bovine femoral heads were impacted into shear test rings. A range of frequencies of vibration was tested, as measured using an accelerometer housed in a vibration chamber. Each shear test was repeated at four different normal loads to generate stress-strain curves. The Mohr-Coulomb failure envelope from which shear strength and interlocking values are derived was plotted for each test. The experiments were repeated with the addition of blood in order to replicate a saturated environment. Graft impacted with the addition of vibration at all frequencies showed improved shear strength when compared with impaction without vibration, with 60 Hz giving the largest effect. Under saturated conditions the addition of vibration was detrimental to the shear strength of the aggregate. The civil-engineering principles of particulate settlement and interlocking also apply to impaction bone grafting. Although previous studies have shown that vibration may be beneficial in impaction bone grafting on the femoral side, our study suggests that the same is not true in acetabular revision.