The influence of pre-operative Computed Tomography (CT) on surgical approach and fixation for fractures of the tibial plateau.

Background: It is well known that a computed tomography (CT) scan improves the classification of tibial plateau fractures (TPF) compared with radiographs. However, it is less clear how this translates into clinical practice. The aim of this study is to establish to what extent a pre-operative CT scan alters the approach, setup and fixation choice in TPF compared to radiographs. Methods: 50 consecutive TPF with a preoperative CT and radiographic imaging available, were assessed by 4 consultant surgeons. First, anonymised radiographs were classifying according to the column classification and the planned setup, approach, and fixation technique documented. At a 1-month interval, randomised matched CT scans were assessed and the same data collected. A tibial plateau disruption score (TPDS) was derived for all 4 quadrants (no injury = 0, split = 1, split/depression = 2 and depression = 3). Radiograph and CT TPDS were assessed using an unpaired T-test. Results: 26 female and 24 male patients, mean age 50.3, were included. Mean TPDS on radiographs and CT scans were 2.77 and 3.17 respectively. A significantly higher CT TPDS, of 0.4 (95%CI 0.10-0.71)[P = 0.0093] was observed, demonstrating that radiographs underestimate the extent of injury. The surgical approach changed in 28.5% of cases, thus influencing a change in the patient setup in theatre in 27% of cases. Identification of fractures within a column changed in 34% of cases. A high intra-observer reliability was observed when surgeons were asked to repeat their assessment in a third round at a further one month interval. Conclusion: A pre-operative CT scan has a significant effect on the approach required to fix TPF. This therefore influences the setup of the patient and can justifiably be requested as part of pre-operative planning.

Sequential webcam monitoring and modeling of marine debris abundance.

The amount of marine debris washed ashore on a beach in Newport, Oregon, USA was observed automatically and sequentially using a webcam system. To investigate potential causes of the temporal variability of marine debris abundance, its time series was compared with those of satellite-derived wind speeds and sea surface height off the Oregon coast. Shoreward flow induced by downwelling-favorable southerly winds increases marine debris washed ashore on the beach in winter. We also found that local sea-level rise caused by westerly winds, especially at spring tide, moved the high-tide line toward the land, so that marine debris littered on the beach was likely to re-drift into the ocean. Seasonal and sub-monthly fluctuations of debris abundance were well reproduced using a simple numerical model driven by satellite-derived wind data, with significant correlation at 95% confidence level.

Tertiary hyperparathyroidism attributable to long-term oral phosphate therapy.

OBJECTIVE: To report a rare case of tertiary hyperparathyroidism (HPT) as a result of long-term oral phosphate therapy. METHODS: We present a case report, with a focus on clinical manifestations and biochemical findings during the course of tertiary HPT, and discuss the pathophysiologic features of this disorder and the therapeutic strategies. RESULTS: A 35-year-old woman, 22 years after the initial diagnosis of familial hypophosphatemic rickets and initiation of treatment with phosphate and vitamin D, underwent assessment for recurrent symptomatic kidney stones, bone pain, and fatigue. Laboratory studies performed 10 months before this presentation showed findings consistent with secondary HPT. Examination was notable for short stature, and pertinent laboratory results were as follows: intact parathyroid hormone 602 pg/mL, calcium 10.9 mg/dL, and phosphorus 3.6 mg/dL. Tertiary HPT was diagnosed, and she underwent subtotal parathyroidectomy and transcervical thymectomy. Postoperatively, she had hypocalcemia and was treated with calcitriol, phosphate, and calcium carbonate; the last agent was discontinued when the serum calcium normalized. Despite multiple dosage alterations in the phosphate and calcitriol therapy, the patient had recurrent tertiary HPT and another kidney stone (treated by lithotripsy). Three years after the subtotal parathyroidectomy, treatment consisted of cinacalcet, calcitriol, and elemental phosphate. CONCLUSION: Long-term follow-up of patients with tertiary HPT is critical, with careful dosage adjustments in phosphate and vitamin D therapy and monitoring of serum levels of phosphorus, calcium, and parathyroid hormone.