Fracture mechanisms and fracture pattern in men and women aged 50 years and older: a study of a 12-year population-based injury register,Umeå, Sweden

Summary

In a study of a 12-year population-based injury register, Umeå, Sweden, we analyzed the fracture mechanisms and fracture pattern in men and women 50 years and older. Low-energy trauma was responsible for the major and costliest part of the fracture panorama, but the pattern differs between age groups.

Introduction

Osteoporosis-related fracture is a major health problem: the number of hip fractures is expected to double to 2030. While osteoporosis is one of many risk factors, trauma is almost always involved. Therefore, we analyzed injury mechanisms in patients aged over 50.

Methods

We registered injury mechanism, cause, diagnosis in all trauma patients at Umeå University hospital, Sweden. This population-based register (1993–2004) comprises a total of 113,668 injuries (29,189 fractures). Patients ≥50 years contributed to 13,279 fractures.

Results

Low-energy trauma (fall <1 m) caused 53% of all fractures ≥50 years and older. In those over 75 low-energy trauma caused >80%. The seasonal variation of fractures was maximally 25%. With increasing age, proximal fractures became more common, in both upper and lower extremities. Proximal locations predominate in older age groups.

Conclusions

Low-energy trauma was responsible for the largest and costliest part of the fracture panorama. In fact, almost all fractures in middle-aged and old people were caused by low-energy mechanisms; thus, most fractures in these patients have a fragility component, and the contribution of osteoporosis-related fractures is more important than previously thought. A better understanding of injury mechanisms also in low-energy trauma is a prerequisite for preventive interventions.     

Technical refinements of composite thoracodorsal system free flaps for 1-stage lower extremity reconstruction resulting in reduced donor-site morbidity

A multitude of local flaps has been suggested for lower extremity reconstruction. However, the gold standard for defect coverage remains free tissue transfer. In this regard, the scapular vascular axis is a well-established source of expendable skin, fascia, muscle, and bone for use in free flap reconstruction of defects requiring bone and soft tissue in complex 3-dimensional relationships.Composite bone and soft-tissue flaps derived from the subscapular vascular axis include the osteocutaneous scapular flap, the "latissimus/bone flap," and the thoracodorsal artery perforator-scapular osteocutaneous flap.Patient outcome following reconstruction of lower extremity defects with composite free flaps from the thoracodorsal system were analyzed. Here, we demonstrate the execution of technical refinements on free composite flap transfers based on the thoracodorsal vascular axis, thus resulting in a stepwise reduction of donor-site morbidity.     

A comparison of actual registered costs and costs derived from diagnosis-related groups (DRGs) for patients undergoing heart transplantation, lung transplantation, and thoracotomy for other lung diseases

The Norwegian health care system, like other health care systems in the world, is in the midst of a changing financial environment for hospital reimbursement for patient care. Since 1997 the Norwegian government has introduced a new financing model of block grant and activity-based financing. In this model, diagnosis-related groups (DRGs) play an important role in hospital financing. The initial motive for developing the DRGs was to improve hospital productivity and efficiency and to develop a tool to control increasing hospital costs better. We raised the question as to whether the DRG system in fact covers actual costs in patient groups undergoing heart transplantation (n = 12), lung transplantation (n = 4), and thoracotomy for other diseases (n = 10). A new prospective cost model was developed to measure actual costs related to individual patients. The patients were closely observed and the related data collected during the hospital stay. Each patient's hospital stay was divided into four different categories of resource requirements, defined as heavy intensive care, light intensive care, intermediate care, and ordinary care. In addition, the number of staff involved and the duration of surgery and procedures were recorded, as were medicine costs and material costs. Based on these data, the actual costs for each patient were calculated. These were then compared with the respective DRG reimbursement (100 % coverage) for the corresponding group. We found that the median cost for heart transplantation was US$ 50,590 (1 US$ = 7.5 NOK based on the exchange rate at the time of the study), while the respective DRG reimbursement was US$ 65,662. For lung transplantation, the respective figures were US$ 46,668 vs US$ 65,662, and for thoracotomy, US$ 24,307 vs US$ 11,004. We found that our method was applicable to a hospital setting. DRG coverage for heart and lung transplantation seems to overestimate the actual costs. For the thoracotomy procedure, the DRG coverage did not cover the actual costs. Received: 3 July 2000 Revised: 21 May 2001 Accepted: 12 June 2001     

Similar rates of exponential decrease in serum concentrations of free prostate-specific antigen (PSA), PSA complexed to alpha-1-antichymotrypsin, and human glandular kallikrein 2 (hK2) in prostate cancer patients treated with GnRH-analogues

BACKGROUND: Our recently reported finding of rapid bi-exponential elimination of free prostate-specific antigen (PSA) after radical retropubic prostatectomy in patients with moderately elevated PSA levels, which contrasted a very slow, linear elimination of PSA complexed to alpha-1-antichymotrypsin (ACT), prompted us to study whether these elimination rates were applicable for patients selected for castration treatment with very high pretreatment concentrations of PSA in serum. In addition, serum concentrations of hK2, the activator of proPSA, were measured. METHODS: Pretreatment serum was obtained from 21 previously untreated prostate cancer patients due for hormonal treatment with a GnRH-analog. Samples were also collected during treatment up to a minimum of 24 weeks at 2-week intervals and analyzed with immunofluorometric assays for free PSA (PSA-F), PSA complexed to alpha-1-antichymotrypsin (PSA-ACT), total PSA (PSA-T), and human kallikrein 2 (hK2). For pharmaco-kinetic analysis the serum concentrations of hK2 and PSA forms for each patient were plotted against time both before and after logarithmic transformation and the half-lives were calculated as ln2/k. RESULTS: Median pretreatment serum concentrations were 322 ng/ml (range, 1.9-2210) for PSA-T, 27.8 ng/ml (range, 1.14-259) for PSA-F, and 207 ng/ml (range, 0.8-2080) for PSA-ACT. All patients had castrate levels of serum testosterone (< 2.5 nmol/l) in less than 21 days after initiation of GnRH-analog treatment. It was possible to evaluate data from 19/21 patients which showed an exponential decrease of all PSA concentrations in serum, with mean half-lives of 12.9 days (range, 7.3-30) for PSA-T, 15.5 days (range, 7.7-37.5) for PSA-F, and 12.3 days (range, 6.6-30) for PSA-ACT. Median pretreatment percent free PSA (PSA-F/PSA-T) was 12% compared to 18% at nadir. The median pretreatment level of hK2 was 3.5 ng/ml (range, 0.29-30.3). There was an exponential decrease in hK2 concentrations in serum after initiation of hormonal treatment with a mean half-life of 18.7 days (range, 7.5-37.5). CONCLUSIONS: For the majority of patients with hormonally treated prostate cancer the serum concentrations of PSA-T, PSA-F, PSA-ACT, and hK2 decreased slowly in parallel and mono-exponentially after initiation of treatment. Mean half-lives were between 12 and 19 days.     

Inclusion of lignocaine base into a polar lipid formulation--in vitro release, duration of peripheral nerve block and arterial blood concentrations in the rat

BACKGROUND: Slow-release formulations of local anaesthetics may produce nerve blocks of long duration. The present study aimed at investigating the in vitro and in vivo properties of a polar lipid formulation for slow release of lignocaine and the effects on nerve block duration by inclusion of dexamethasone into the system. METHODS: In vitro release of lignocaine from the lipid formulation was studied in a US Pharmacopoeia rotating apparatus. Sciatic nerve blocks were induced in rats by 0.1 ml of test formulations containing lignocaine HCl 20 mg. ml-1 in aqueous solution, lignocaine base 20, 100 or 200 mg. ml-1 in lipid formulation or the last formulation with dexamethasone 0.05, 0.5 or 5 mg. ml-1. The durations of sensory and motor block and the arterial blood concentrations of lignocaine were investigated. RESULTS: In vitro there was a sustained release of lignocaine from the lipid formulation, with 50% release at around 48 h. In vivo lignocaine base 20 mg. ml-1 in lipid formulation produced sciatic nerve blocks of significantly shorter duration than lignocaine HCl 20 mg. ml-1 in aqueous solution, while lignocaine base 100 and 200 mg. ml-1 in lipid formulation produced blocks lasting two and three times longer, respectively, than the lignocaine HCl solution. Addition of dexamethasone did not affect the duration of nerve block. Following administration of lignocaine base 200 mg. ml-1 in lipid formulation, as compared to lignocaine HCl 20 mg. ml-1 in aqueous solution, the maximal blood concentration of lignocaine was only three times higher in spite of the ten-fold difference in dose, and the mean terminal half-life was three times longer, reflecting the slow release from the formulation. CONCLUSIONS: Our findings indicate that lignocaine base in polar lipids acts as a slow-release preparation of local anaesthetic both in vitro and in vivo.     

Anticoagulation intensity sufficient for haemodialysis does not prevent activation of coagulation and platelets.

BACKGROUND: A single bolus of dalteparin at the start of haemodialysis (HD) may prevent clot formation, but subclinical activation of platelets and coagulation may still occur. Consequently, the relationship between clinical clotting events and activation markers of platelets and coagulation before and during HD is of interest. METHODS: The effect of tapered doses of dalteparin during 84 HD sessions (4-4.5 h) was prospectively examined in 12 patients. Six of the patients were treated with warfarin. The initial dalteparin dose was reduced to 50% if no clotting was observed. Clinical clotting was evaluated by inspection of the air trap every hour and by inspection of the dialyser after each session. Anti-FXa activity was measured for assessment of dalteparin activity. Markers of activated plasma coagulation, (thrombin-antithrombin (TAT) and prothrombin fragment 1+2 (PF1+2)) and a marker of platelet activation (beta-thromboglobulin, beta-TG), were measured before the start of and after 3 and 4 h of dialysis. Ten pre-dialytic patients with chronic renal failure served as a control group. A total of 230 measurements of each parameter were performed. RESULTS: An anti-FXa activity above 0.4 IU/ml at the end of HD inhibits overt clot formation for 4 h. This was obtained by an intravenous dalteparin dose of about 5000 IU. TAT and PF1+2 correlated to clinical clotting episodes (r=0.50 and 0.47, P<0.001). beta-TG was not significantly correlated to clinical clotting. All parameters increased during the sessions (TAT, PF1+2, beta-TG, P<0.001). When measurements during clinical clotting episodes were disregarded, all parameters were still markedly increased. Warfarin-treated patients had lower TAT and PF1+2. Dialysis patients had higher beta-TG values than pre-dialytic patients. CONCLUSION: Despite clinically effective anticoagulation, obtained by dalteparin administration, platelets and coagulation are activated by HD, resulting in a potentially thrombophilic state. Warfarin treatment reduces clinical clot formation and subclinical activation of coagulation.     

Hemiarthroplasty in worst cases is better than internal fixation in best cases of displaced femoral neck fractures: a prospective study of 683 patients treated with hemiarthroplasty or internal fixation

Background Studies have shown that the degree of initial displacement and also comminution of the femoral calcar, size of the head and varus angulation are prognostic of failure in displaced femoral neck fracture. We have applied these radiographic criteria in order to select patients who would benefit from internal fixation as opposed to primary hemiarthroplasty, and this prospective study was conducted in order to monitor the results of this strategy.

Methods 683 displaced fractures of the femoral neck were treated with internal fixation or primary hemiarthroplasty based on the proposed radiographic criteria in a prospective consecutive study, and the patients were followed for 1-6 years. We treated 228 fractures with internal fixation and 455 by bipolar hemiprosthesis. The choice of operation was based on clinical evaluation of the patient and assessment of the assumed healing potential of the fracture, as determined by radiographic evaluation. Revision and mortality were primary endpoints.

Results 54 (24%) of the patients originally treated by osteosynthesis were revised, whereas 9 (2%) of the patients treated with hemiarthroplasty had revision surgery. There were no significant differences in mortality between the groups at 30, 120 or 365 days.

Interpretation Even when treating only the fractures with the assumed best healing potential with internal fixation, the results are inferior to hemiarthroplasty.     

Endovascular treatment of iliac artery aneurysms with a tubular stent-graft: mid-term results

OBJECTIVE: To report the mid term results of a prospective cohort of iliac artery aneurysms (IAAs) treated with endovascular tubular stent-grafts. METHODS: All IAAs referred to the University Medical Center Groningen between June 1998 and June 2005 were evaluated for endovascular repair. Criteria for repair were a diameter of > or = 30 mm for anastomotic aneurysms and > or = 35 mm for true aneurysms. Preferentially, tubular grafts were used. Follow-up included both radiographs of the abdomen and duplex examination. RESULTS: In 35 patients, 40 IAAs were treated endovascularly with a tubular stent-graft. Elective repair was performed in 30 patients (86%) and emergent repair in five patients (14%). Aneurysms were false in 26 cases (65%) and true in 14 cases (35%). Local anesthesia was used in 74% of the cases. The stent-grafts that were used included the Excluder contralateral limb (n = 28, 70%), Passager (n = 9, 22.5%), Hemobahn (n = 2, 5%), and Wallgraft (n = 1, 2.5%). The mean operation time was 83 +/- 28 minutes (range, 50 to 150 minutes). Mean hospital stay was 3.3 +/- 2.3 days (range, 1 to 12 days). There was no 30-day mortality. Patients were followed up for a mean of 31.2 +/- 20.7 months (range, 3 to 83 months). Complications occurred in two patients during follow-up, including migration with a proximal type I endoleak in one, and occlusion of the stent-graft in the other. The internal iliac artery was intentionally sacrificed in 28 patients (70%), and this led to gluteal claudication in three patients. CONCLUSION: Endovascular repair of iliac artery aneurysms with flexible stent-grafts is a minimally invasive technique and is associated with low mortality and morbidity. Follow-up results up to 5 years suggest that the technique is durable. It should be regarded as a first choice treatment option for suitable aneurysms.     

Validation of diffuse correlation spectroscopy against 15O-water PET for regional cerebral blood flow measurement in neonatal piglets

Diffuse correlation spectroscopy (DCS) can non-invasively and continuously asses regional cerebral blood flow (rCBF) at the cot-side by measuring a blood flow index (BFI) in non-traditional units of cm²/s. We have validated DCS against positron emission tomography using ¹⁵O-labeled water (¹⁵O-water PET) in a piglet model allowing us to derive a conversion formula for BFI to rCBF in conventional units (ml/100g/min). Neonatal piglets were continuously monitored by the BabyLux device integrating DCS and time resolved near infrared spectroscopy (TRS) while acquiring ¹⁵O-water PET scans at baseline, after injection of acetazolamide and during induced hypoxic episodes. BFI by DCS was highly correlated with rCBF (R = 0.94, p < 0.001) by PET. A scaling factor of 0.89 (limits of agreement for individual measurement: 0.56, 1.39)×10⁹× (ml/100g/min)/(cm²/s) was used to derive baseline rCBF from baseline BFI measurements of another group of piglets and of healthy newborn infants showing an agreement with expected values. These results pave the way towards non-invasive, cot-side absolute CBF measurements by DCS on neonates.