The changing epidemiology of radial head replacement over a 22-year period in Scotland.

BACKGROUND: Radial head replacement is used to confer joint stability in the management of acute unstable elbow fractures and dislocations associated with instability. We determined the annual incidence of radial head replacement over a 22-year period in a defined population. MATERIALS AND METHODS: Hospital episode statistics were collected prospectively at a national level. This database was retrospectively examined to determine the annual incidence of radial head replacement over the study period in adults over 16 years of age. RESULTS: A total of 615 radial head replacements were performed over the 22 years studied. The overall incidence was 0.65/100,000/year (95% confidence interval, CI, 0.50-0.71). The average adult population during the period was 4,270,593. There was a steady and statistically significant increase in the incidence of radial head replacement over the study period (r 2 = 0.816; p < 0.0001). This incidence was significantly greater in women than men (odds ratio 1.46, 95% CI 1.25-1.72; p < 0.001). The peak incidence in men was 0.87/100,000 population/year in the fifth decade of life while in women the peak incidence was in the seventh decade of life (1.38/100,000 population/year). CONCLUSION: The incidence of radial head replacement has increased steadily over 22 years. We hypothesise that this represents an evolving understanding of the role of radial head replacement in acute trauma in the context of emerging literature during the study period.

Reconstruction of the glenoid using autologous bone-graft and the SMR Axioma TT metal-backed prosthesis: the first 45 sequential cases at a minimum of two years' follow-up.

AIMS: We present our experience of using a metal-backed prosthesis and autologous bone graft to treat gross glenoid bone deficiency. PATIENTS AND METHODS: A prospective cohort study of the first 45 shoulder arthroplasties using the SMR Axioma Trabecular Titanium (TT) metal-backed glenoid with autologous bone graft. Between May 2013 and December 2014, 45 shoulder arthroplasties were carried out in 44 patients with a mean age of 64 years (35 to 89). The indications were 23 complex primary arthroplasties, 12 to revise a hemiarthroplasty or resurfacing, five for aseptic loosening of the glenoid, and five for infection. RESULTS: Of the 45 patients, 16 had anatomical shoulder arthroplasties (ASA) and 29 had reverse shoulder arthroplasties (RSA). Postoperatively, 43/45 patients had a CT scan. In 41 of 43 patients (95%), the glenoid peg achieved > 50% integration. In 40 of 43 cases (93%), the graft was fully or partially integrated. There were seven revisions (16%) but only four (9%) required a change of baseplate. Four (25%) of the 16 ASAs were revised for instability or cuff failure. At two-year radiological follow-up, five of the 41 cases (11%) showed some evidence of lucent lines. CONCLUSION: The use of a metal baseplate with a trabecular titanium surface in conjunction with autologous bone graft is a reliable method of addressing glenoid bone defects in primary and revision RSA setting in the short term. ASAs have a higher rate of complications with this technique.

Surgical simulation flexor tendon repair using Thiel cadavers: a comparison with formalin embalmed cadavers and porcine models.

UNLABELLED: The aim of this study was to compare Thiel-embalmed cadavers with formalin-embalmed cadavers and porcine models in the surgical simulation repair of a Zone II flexor tendon division. Nine participants were recruited to the study. The models were assessed using a five-point scale. Assessment was divided into tissue quality, surgical approach and identification of structures. Thiel cadavers rated consistently higher compared with the formalin and porcine models (mean 37 SD 2, 22 SD 6 and 23 SD 5, respectively). Thiel cadavers recorded an average tendon glide of 21 mm SD 5, formalin cadavers 2 mm SD 2 and the porcine model 6 mm SD 2. We have demonstrated the benefit of Thiel embalming, with flexibility of tissues allowing testing of the repair of a flexor tendon in a realistic anatomical model. LEVEL OF EVIDENCE: Level V.

Causative organisms in revision total hip & knee arthroplasty for infection: Increasing multi-antibiotic resistance in coagulase-negative Staphylococcus and the implications for antibiotic prophylaxis.

BACKGROUND AND PURPOSE: Increasing resistance among post-operative Coagulase-negative Staphylococci (CNS) infections have been reported. We present our experience changing resistance patterns. METHODS: We examined microbiological results from hip and knee revisions from 2001 to 2010 and compared resistance to all Staphylococcus aureus (SA) and CNS cultured from regional pan-speciality sources, in order to examine the patterns of antibiotic resistance. MAIN FINDINGS: 72 revisions in 67 patients were included. The most common organisms were SA (36%) and CNS (35%). Resistance to methicillin was 72% for CNS versus 20% for SA and resistance to gentamicin was 40% for CNS versus 4% for SA. Among all regional (background pan-speciality) cultures SA resistance to methicillin fell from 32% to 16% from 2006 to 10 with no change in gentamicin resistance at 3%. During the same period resistance of CNS to methicillin and gentamicin increased from 63% to 70% and 32%-47% respectively. CONCLUSIONS: Resistance of CNS to both methicillin and gentamicin is higher than with SA and appears to be increasing. At least 32% of CNS and 4% of SA from infected TKRs/THRs were resistant to our current prophylaxis regime. These changing patterns of resistance may have implications for future antibiotic prophylaxis regimes.

Peri-operative renal morbidity secondary to gentamicin and flucloxacillin chemoprophylaxis for hip and knee arthroplasty.

INTRODUCTION: This retrospective cohort study uses serum creatinine levels to assess the effect of gentamicin and flucloxacillin on renal function in hip and knee arthroplasty patients. METHODS: Serum creatinine levels were recorded pre-operatively and at two points post-operatively (sample 1 and sample 2) for all patients undergoing hip and knee arthroplasty. Either cefuroxime, or gentamicin and flucloxacillin were used for chemoprophylaxis. The Risk, Injury, Failure, Loss, End Stage classification was used to assess renal injury. RESULTS: The differences in mean percentage change between the two groups were 5.86% (p = 0.077) and 11.34% (p = 0.030) at sample 1 and sample 2, respectively. Two patients (1.62%) receiving cefuroxime were exposed to renal risk or worse at some point. A total of nine patients (6.04%) receiving flucloxacillin and gentamicin were exposed to renal risk. Of these, three (2.01%) sustained renal injury and two (1.34%) sustained renal failure. The risk of being exposed to renal risk was 3.75 times greater for the gentamicin and flucloxacillin group. The risks of sustaining a significant deterioration of renal function were 1.9 and 17 times greater for the gentamicin and flucloxacillin group at the first and second post-operative samples, respectively. DISCUSSION: Flucloxacillin and gentamicin significantly worsens renal function post-operatively compared with cefuroxime.

Low-grade central osteosarcoma: a difficult condition to diagnose.

Low-grade central osteosarcoma (LGCO) is a rare variant of osteosarcoma which is difficult to diagnose. If not treated appropriately, the tumour can recur with higher-grade disease. We reviewed our experience of this condition to try and identify factors that could improve both diagnosis and outcome. 18 patients out of 1540 osteosarcoma cases (over 25 years) had LGCO (1.2%). Only 11 patients (61%) were direct primary referrals. Almost 40% (7 of 18) cases were referred after treatment elsewhere when the diagnosis had not been made initially and all presented with local recurrence. Of the 11 who presented primarily, the first biopsy was diagnostic in only 6 (55%) cases. Of the remaining cases, up to three separate biopsies were required before a definitive diagnosis was made. Overall survivorship at 5 years was 90%. 17 patients were treated with limb salvage procedures, and one patient had an amputation. The diagnosis of LGCO remains challenging due to the relatively nonspecific radiological and histological findings. Since treatment of LGCO is so different to a benign lesion, accurate diagnosis is essential. Any difficult or nondiagnostic biopsies of solitary bone lesions should be referred to specialist tumour units for a second opinion.

The final diagnosis in patients with a suspected primary malignancy of bone.

We investigated the eventual diagnosis in patients referred to a tertiary centre with a possible diagnosis of a primary bone malignancy. We reviewed our database from between 1986 and 2010, during which time 5922 patients referred with a suspicious bone lesion had a confirmed diagnosis. This included bone sarcoma in 2205 patients (37%), benign bone tumour in 1309 (22%), orthopaedic conditions in 992 (17%), metastatic disease in 533 (9%), infection in 289 (5%) and haematological disease in 303 (5%). There was a similar frequency of all diagnoses at different ages except for metastatic disease. Only 0.6% of patients (17 of 2913) under the age of 35 years had metastatic disease compared with 17.1% (516 of 3009) of those over 35 years (p < 0.0001). Of the 17 patients under 35 years with metastatic disease, only four presented with an isolated lesion, had no past history of cancer and were systematically well. Patients under the age of 35 years should have suitable focal imaging (plain radiography, CT or MRI) and simple systemic studies (blood tests and chest radiography). Reduction of the time to biopsy can be achieved by avoiding an unnecessary investigation for a primary tumour to rule out metastatic disease.

Polycystin-1: immunoaffinity isolation and characterisation by mass spectrometry.

Polycystin-1 is a putative 460 kDa membrane protein with a unique structure and is possibly representative of a new family of proteins. Its structure suggests an involvement in cell signalling and cell-matrix interactions. The amino acid sequence of polycystin-1 has to date been predicted from its gene sequence. This, to our knowledge, is the first report of the isolation and analysis of polycystin-1 at the protein level using mass spectrometry to confirm its predicted structure. The availability of purified polycystin-1 will allow a new approach to unravelling the complexity of the cell-cell and cell-matrix interactions of this large molecule in normal cells and its perturbation in disease.