OBJECTIVES

Based on a multi-factorial model of delirium, we compared the types and magnitude of pre- and intra-operative predisposing factors for incident delirium in a stratified sample of acute hip fracture repair patients with and without pre-operative dementia.

DESIGN and SETTING

A prospective cohort study based in an academic medical center.

PARTICIPANTS

425 non-delirious, acute hip fracture patients (mean age: 80.2 +/− 6.8; female: 73.2%; “probable dementia”: 33.1%) admitted to the multi-disciplinary hip fracture repair service.

MEASUREMENTS

Each participant was assessed for delirium by a research nurse based on the Confusion Assessment Method (CAM) before study enrollment and from the second postoperative day until hospital discharge.

RESULTS

The incidence of delirium was higher in the Probable Dementia Group than in the No Dementia Group (54% vs. 26%; p≤ 0.001). In the No Dementia group (n = 284), age (OR: 1.07; 95% CI: 1.02-1.13), male gender (OR: 2.81; 95% CI: 1.40-5.64), BMI (OR: 0.92; 95% CI: 0.86-0.99), number of medical comorbidities (OR: 1.15; 95% CI: 1.01-1.32), and duration of surgery longer than two hours (OR: 2.53; 95% CI: 1.20-4.88) were independently associated with a post-operative delirium. In the Probable Dementia group, only the lag time from emergency room to operation room was significantly associated (OR: 2.83; 95% CI: 1.24-2.25) with delirium.

CONCLUSION

Pre-operative determination of dementia status is important for risk stratification for incident delirium after acute hip fracture repair surgery because types and magnitude of predisposing risk factors for post-operative delirium substantially differ based on their pre-operative dementia status.

Objectives

To test the hypotheses that, compared with controls 1) femoroplasty (the injection of bone cement into the proximal femur in an attempt to prevent fragility fracture) increases the yield and ultimate loads, yield and ultimate energies, and stiffness of the proximal osteoporotic femur in a simulated fall model; and 2) the manner in which the cement distributes in the proximal femur affects the extent to which those mechanical properties are altered.

Methods

In 10 pairs of osteoporotic human cadaveric femora, we injected 1 femur of each pair with 40 -- 50 mL of polymethylmethacrylate bone cement; the noninjected femur served as the control. The filling percentage was calculated in 4 anatomical regions of the femur: head, neck, trochanter, and subtrochanter. All specimens were biomechanically tested in a configuration that simulated a fall on the greater trochanter. Student's t test, linear regression, and multinomial logistic regression statistical analyses were conducted where appropriate, with significant difference defined as P < 0.05.

Results

Femoroplasty significantly increased yield load (22.0%), ultimate load (37.3%), yield energy (79.6%), and ultimate energy (154%) relative to matched controls, but did not significantly change stiffness (-10.9%). There was a strong (r2 = 0.7) correlation between yield load and filling percentage in the femoral neck.

Conclusions

This study showed that 1) femoroplasty significantly increased fracture load and energy to fracture when osteoporotic femora were loaded in simulated fall conditions and 2) cement filling in the femoral neck may have an important role in the extent to which femoroplasty affects mechanical strength of the proximal femur.

It is unclear if a decrease in cancellous bone density or cortical bone thickness is related to sacral insufficiency fractures. We hypothesized that reduction in overall bone density leads to local reductions in bone density and cortical thickness in cadaveric sacra that match clinically observed fracture patterns in patients with sacral insufficiency fractures. We used quantitative computed tomography to measure cancellous density and cortical thickness in multiple areas of normal, osteopenic, and osteoporotic sacra. Cancellous bone density was significantly lower in osteoporotic specimens in the central and anterior regions of the sacral ala compared with other regions of these specimens. Cortical thickness decreased uniformly in all regions of osteopenic and osteoporotic specimens. These results support our hypothesis that areas of the sacrum where sacral insufficiency fractures often occur have significantly larger decreases in cancellous bone density; however, they do not support the hypothesis that these areas have local reduction of cortical bone thickness.

Background

Perioperative management of patients with heterozygous protein C deficiency is challenging because of the competing risks of bleeding and recurrent thrombosis.

Case Description

We report the case of a 74-year-old man with protein C deficiency and heterozygous prothrombin G20210A gene mutation who had a successful left THA with perioperative administration of human zymogen protein C concentrate in addition to anticoagulation with enoxaparin.

Literature Review

Several studies have reported the use of protein C concentrate in severe sepsis-associated purpura fulminans in patients with severe congenital protein C deficiency who have had thrombotic events. We reviewed studies and case reports pertinent to the treatment of patients with protein C deficiency, especially in the perioperative setting. We report the case of a patient undergoing THA in whom we used human zymogen protein C concentrate.

Purposes and Clinical Relevance

THA, a particularly high-risk procedure, is associated with a 40% to 70% incidence of venographic deep venous thrombosis and a 2% to 3% incidence of symptomatic deep venous thrombosis. These risks are greater in people with thrombophilic defects such as protein C deficiency. The use of human zymogen protein C in our patient with heterozygous protein C deficiency during the perioperative period of a THA was associated with no evidence of excessive bleeding, hematoma, deep venous thrombosis, or pulmonary embolism.

OBJECTIVE: To determine whether limiting intraoperative sedation depth during spinal anesthesia for hip fracture repair in elderly patients can decrease the prevalence of postoperative delirium.

PATIENTS AND METHODS: We performed a double-blind, randomized controlled trial at an academic medical center of elderly patients (≥65 years) without preoperative delirium or severe dementia who underwent hip fracture repair under spinal anesthesia with propofol sedation. Sedation depth was titrated using processed electroencephalography with the bispectral index (BIS), and patients were randomized to receive either deep (BIS, approximately 50) or light (BIS, ≥80) sedation. Postoperative delirium was assessed as defined by Diagnostic and Statistical Manual of Mental Disorders (Third Edition Revised) criteria using the Confusion Assessment Method beginning at any time from the second day after surgery.

RESULTS: From April 2, 2005, through October 30, 2008, a total of 114 patients were randomized. The prevalence of postoperative delirium was significantly lower in the light sedation group (11/57 [19%] vs 23/57 [40%] in the deep sedation group; P=.02), indicating that 1 incident of delirium will be prevented for every 4.7 patients treated with light sedation. The mean ± SD number of days of delirium during hospitalization was lower in the light sedation group than in the deep sedation group (0.5±1.5 days vs 1.4±4.0 days; P=.01).

CONCLUSION: The use of light propofol sedation decreased the prevalence of postoperative delirium by 50% compared with deep sedation. Limiting depth of sedation during spinal anesthesia is a simple, safe, and cost-effective intervention for preventing postoperative delirium in elderly patients that could be widely and readily adopted.

Trial Registration: clinicaltrials.gov Identifier: NCT00590707

Use of light propofol sedation decreased the prevalence of postoperative delirium by 50% compared with deep sedation. Limiting depth of sedation during spinal anesthesia is a simple, safe, and cost-effective intervention for preventing postoperative delirium in elderly patients that could be widely and readily adopted.

Multimodal anesthetic and pain regimens with minimally invasive surgical approaches and rapid rehabilitation protocols are thought to decrease length of stay after hip replacement. We asked whether a program including these three elements could achieve 23-hour discharge in a group of 665 patients and whether the length of hospital stay was influenced by patient age, gender, body mass index, change in hemoglobin or estimated blood loss, duration of surgery (≤ 90 or > 90 minutes), or American Society of Anesthesiologists physical status classification. Of the 665 patients, 259 (38.9%) were discharged home with indwelling peripheral nerve catheters. Hospital discharge in less than 24 hours was achieved in 295 (44.4%) of the 665 patients. After discharge, 73.5% of patients required no home or outpatient nursing care or physical therapy. Eighteen (2.7%) dislocations, eight (1.2%) femoral fractures requiring surgery, and thirteen (2.0%) revision procedures occurred within 90 days. Female gender, increasing age, increasing estimated blood loss, and American Association of Anesthesiologists classification 3 or 4 increased length of stay. Additional study is needed to confirm these factors and develop prospective prediction rules to allow for an outpatient approach to joint arthroplasty.

Level of Evidence: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Objective: Site marking is essential to prevent wrong-site surgery, and there are many skin markers commercially available. However, preoperative skin preparation can erase the site mark, especially when a chlorhexidine skin preparation solution that requires skin scrubbing is used. The purpose of our study was to test the hypothesis that some markers can withstand skin preparation with a chlorhexidine-based skin preparation solution in a manner similar to that of an iodine-based solution. Methods: On each of 5 cadaveric skin flaps, we made 2 rows of site markings with 9 types of markers. We then subjected one row of markings on each flap to a chlorhexidine-based solution and the other row to an iodine-based solution. A digital photograph was taken before and after each skin preparation. Using imaging software, the contrast in grayscale between the skin and skin marking was measured on each photograph. The effect of the type of marker and skin preparation solution on the difference in grayscale contrast was evaluated by multiple linear regression analysis and significant differences were determined (P < .05). Results: In all cases, the chlorhexidine-based skin preparation solution significantly decreased the contrast measured. No marker was significantly better than another. Conclusions: We conclude that all 9 skin markers are significantly erased with the chlorhexidine-based skin preparation solution. The development of a better skin marker or a chlorhexidine-based skin preparation solution that does not erase site markings is essential to prevent wrong-site surgeries and promote patient safety.

Recent increase in both the elderly population and associated incidence of dementia are of critical importance to patient care in intensive care units (ICU) in the United States. Identification of pre-existing cognitive impairment such as mild cognitive impairment and dementia could prevent delirium and associated morbidity and mortality in ICU. Additionally, non-cognitive behavioral symptoms such as depression, psychosis, agitation, and catastrophic reactions are common in patients with pre-existing cognitive impairment. Detection and management of non-cognitive behavioral symptoms associated with demented elderly patients in ICU leads to improved delivery of life-saving critical care.

Periacetabular osteotomy (PAO) is intended to treat a painful dysplastic hip. Manual radiological angle measurements are used to diagnose dysplasia and to define regions of insufficient femoral head coverage for planning PAO. No method has yet been described that recalculates radiological angles as the acetabular bone fragment is reoriented. In this study, we propose a technique for computationally measuring the radiological angles from a joint contact surface model segmented from CT-scan data. Using oblique image slices, we selected the lateral and medial edge of the acetabulum lunate to form a closed, continuous, 3D curve. The joint surface is generated by interpolating the curve and the radiological angles are measured directly using the 3D surface. This technique was evaluated using CT data for both normal and dysplastic hips. Manual measurements made by three independent observers showed minor discrepancies between the manual observations and the computerized technique. Inter-observer error (mean difference±standard deviation) was 0.04±3.53° Observer 1; −0.46±3.13° for Observer 2; and 0.42±2.73° for Observer 3. The measurement error for the proposed computer method was −1.30±3.30°. The computerized technique demonstrates sufficient accuracy compared to manual techniques, making it suitable for planning and intraoperative evaluation of radiological metrics for periacetabular osteotomy.

Background and purpose

Because of the varying structure of dysplastic hips, the optimal realignment of the joint during periacetabular osteotomy (PAO) may differ between patients. Three-dimensional (3D) mechanical and radiological analysis possibly accounts better for patient-specific morphology, and may improve and automate optimal joint realignment.

Patients and methods

We evaluated the 10-year outcomes of 12 patients following PAO. We compared 3D mechanical analysis results to both radiological and clinical measurements. A 3D discrete-element analysis algorithm was used to calculate the pre- and postoperative contact pressure profile within the hip. Radiological angles describing the coverage of the joint were measured using a computerized approach at actual and theoretical orientations of the acetabular cup. Quantitative results were compared using postoperative clinical evaluation scores (Harris score), and patient-completed outcome surveys (q-score) done at 2 and 10 years.

Results

The 3D mechanical analysis indicated that peak joint contact pressure was reduced by an average factor of 1.7 subsequent to PAO. Lateral coverage of the femoral head increased in all patients; however, it did not proportionally reduce the maximum contact pressure and, in 1 case, the pressure increased. This patient had the lowest 10-year q-score (70 out of 100) of the cohort. Another hip was converted to hip arthroplasty after 3 years because of increasing osteoarthritis.

Interpretation

The 3D analysis showed that a reduction in contact pressure was theoretically possible for all patients in this cohort, but this could not be achieved in every case during surgery. While intraoperative factors may affect the actual surgical outcome, the results show that 3D contact pressure analysis is consistent with traditional PAO planning techniques (more so than 2D analysis) and may be a valuable addition to preoperative planning and intraoperative assessment of joint realignment.

Background and purpose Because of the varying structure of dysplastic hips, the optimal realignment of the joint during periacetabular osteotomy (PAO) may differ between patients. Three-dimensional (3D) mechanical and radiological analysis possibly accounts better for patient-specific morphology, and may improve and automate optimal joint realignment.

Patients and methods We evaluated the 10-year outcomes of 12 patients following PAO. We compared 3D mechanical analysis results to both radiological and clinical measurements. A 3D discrete-element analysis algorithm was used to calculate the pre- and postoperative contact pressure profile within the hip. Radiological angles describing the coverage of the joint were measured using a computerized approach at actual and theoretical orientations of the acetabular cup. Quantitative results were compared using postoperative clinical evaluation scores (Harris score), and patient-completed outcome surveys (q-score) done at 2 and 10 years.

Results The 3D mechanical analysis indicated that peak joint contact pressure was reduced by an average factor of 1.7 subsequent to PAO. Lateral coverage of the femoral head increased in all patients; however, it did not proportionally reduce the maximum contact pressure and, in 1 case, the pressure increased. This patient had the lowest 10-year q-score (70 out of 100) of the cohort. Another hip was converted to hip arthroplasty after 3 years because of increasing osteoarthritis.

Interpretation The 3D analysis showed that a reduction in contact pressure was theoretically possible for all patients in this cohort, but this could not be achieved in every case during surgery. While intraoperative factors may affect the actual surgical outcome, the results show that 3D contact pressure analysis is consistent with traditional PAO planning techniques (more so than 2D analysis) and may be a valuable addition to preoperative planning and intraoperative assessment of joint realignment.

Objective: Spontaneous osteonecrosis of the knee affects patients typically over the age of fifty-five years. Evidence exists that this process may not be true necrosis. The purpose of this study was to characterize the demographic, radiographic, and pathologic features of this condition.

Materials and Methods: Twenty-one patients (twenty-two knees) consecutively treated for spontaneous osteonecrosis of the knee were studied.

Results: Only one of twenty-two specimens demonstrated evidence of bone necrosis. No specimens showed fat necrosis, marrow necrosis, fibrous change or appositional bone repair. Fourteen of twenty-two specimens (64%) showed significant osteopenia and fifteen of twenty-two specimens (68%) showed evidence of osteoarthritis.

Conclusions: This study demonstrated that spontaneous osteonecrosis of the knee is not an osteonecrotic condition and has been misnamed. Osteopenia and osteoarthritis may play a role in the pathogenesis of this disease.

Objective: It is important that during preoperative skin preparation surgical site markings are not erased. The effects of 2 common types of skin preparation solutions on surgical site markings were compared. Methods: Fasciocutaneous skin flaps were harvested and 20 random combinations of 3 letters were written on the skin flaps with a black permanent marker. Ten of the 3-letter combinations received Chloraprep (chlorhexidine gluconate, 2% w/v, plus isopropyl alcohol, 70% v/v) and the other 10 received Duraprep (iodine povacrylex [0.7% available iodine] and isopropyl alcohol [74% w/w]), both according to the manufacturer's guidelines. The skin flaps were photographed digitally before and after application of the solutions. The final pictures were assessed subjectively by 10 surgeons and then objectively to determine the change in visibility of the marking on each specimen. Results: Of the 300 letters in each group, the number of correctly identified letters was 254 (84.7%) in the Chloraprep group and 284 (94.7%) in the Duraprep group. On the basis of the visibility of skin markings, Chloraprep was 21.8 times more likely (95% credible interval, 7.3–86.7) to erase the site markings than was Duraprep. Conclusions: Skin preparation with Chloraprep erased more surgical site markings than did Duraprep.

Objective: To present a case report of a patient with an open fracture and severe burns and review the literature. Methods: The patient was treated with intubation, intravenous antibiotics, and debridement and intramedullary nailing for the femur fracture. He later underwent multiple burn excision procedures with allograft and autograft skin coverage. The wound over the fracture was treated with dressing changes. The fracture was treated with nail exchange and bone grafting for atrophic nonunion. Results: The patient was returned to full weightbearing and good function with a fully healed femur. Conclusions: Treatment of open fractures in burn patients should be tailored to the specific needs of the individual; they should be reduced and stabilized via internal fixation at the earliest opportunity and should be managed by minimizing wound colonization through successive debridement, wound care, and consideration of flap coverage.