Intracapsular hip pressure after femoral neck fracture

A consecutive series of 34 patients with femoral neck fractures was included in a prospective study aimed at evaluating preoperative variations in intracapsular pressure after changes in hip position, hip traction, and aspiration of hemarthrosis and their influence on the development of femoral head necrosis. Patients were observed for 7 years after surgery. Before aspiration, the mean intracapsular pressure in the antalgic physiologic position was 44.4 mm Hg. There were no differences between displaced and undisplaced fractures. The pressure was a maximum (mean value, 124.8 mm Hg) with the hip in extension and inward rotation, this pressure being greater than the blood systolic pressure in most cases. Hip traction of 3 kg in the antalgic physiologic position was found to be highly effective in preventing any bone flow tamponade effect in displaced and undisplaced femoral neck fractures: the mean intracapsular pressure decreased to 28.5 mm Hg. Aspiration of the hemarthrosis induced a significant decrease in intracapsular pressure only in cases with impaired vascularity of the femoral head as measured by scintigraphy using 99mTc labeled methyldiphosphonate. Aspiration of the hemarthrosis therefore is indicated only in the above cases, although it is less effective than hip traction in the antalgic position. There was no significant correlation between intracapsular pressure and the scintigraphy ratio. Avascular necrosis of the femoral head was detected in six cases. Among these, five patients had an intracapsular pressure below their diastolic blood pressure. This could indicate that vascular damage related to the fracture could be an important cause of bone necrosis despite that blood supply can be decreased by a tamponade effect.     

Predictors of mortality after acute hip fracture

To identify determinants of mortality after hip fracture, we performed a multicenter, retrospective study of 390 Medicare beneficiaries. Independent predictors of 30-day mortality included a history of congestive heart failure (odds ratio [OR] 32; 95% confidence interval [CI] 5, 192), angina (OR 26; 95% CI 4, 184), or chronic pulmonary disease (OR 11; 95% CI 2, 62). Postoperative use of aspirin was associated with a reduced risk of mortality (OR 0.24; 95% CI 0.08, 0.70). Cardiovascular events were the presumed cause of 63% of in-hospital deaths. Aspirin may have significant potential to reduce mortality in this population and deserves further study.     

Acetabular and femoral fixation 15 years after cemented total hip surgery

Total hip arthroplasty in patients younger than 51 years of age remains controversial. The authors report results in 47 hips in 40 patients at an average followup of 15 years. Second generation femoral cementing techniques were used. Special attention was given to studying the differences between the outcome of acetabular versus femoral fixation. The patient group included 11 in whom custom components were used and 13 who had structural autografts for severe acetabular dysplasia. One femoral component and 10 acetabular components were revised for aseptic loosening. After 15 years, improved cementing techniques produced a marked reduction in the rate of femoral aseptic loosening. Loss of fixation of cemented acetabular components was common.     

Modular unipolar versus bipolar prosthesis: a prospective evaluation of functional outcome after femoral neck fracture

Between January 1, 1987, and December 31, 1992, 140 community-dwelling geriatric patients > or = 65 years of age with a displaced femoral neck fracture (Garden III-IV) underwent primary prosthetic replacement and were followed prospectively for a minimum of 1 year. Overall, 92 patients received a cemented bipolar prosthesis and 48 patients received a cemented modular unipolar prosthesis. There were no statistically significant differences between the two groups with respect to preinjury characteristics (age, sex, and number and severity of medical comorbidities) and functional ability. There were no statistically significant differences between the two groups with regard to the number of postoperative complications, length of stay, and 1 year mortality rate. An in-depth functional evaluation was obtained as follows: level of ambulation, independence in basic activities of daily living (feeding, bathing, dressing, toileting), and independence in instrumental activities of daily living (food shopping, food preparation, banking, laundry, housework, and use of public transportation). At 1 year follow-up, no statistically significant differences in functional ability were identified between the unipolar and bipolar groups. Furthermore, at a minimum of 1 year follow-up, there were no statistically significant differences between the two groups with regard to the need for revision surgery or the incidence hip pain. Based on the results of this study, there does not appear to be any advantage to the use of bipolar endoprosthesis for the treatment of femoral neck fractures in the elderly patient. The lower cost of modular unipolar prostheses compared with bipolar prostheses provides additional support for their use.     

Unipolar or bipolar prosthesis for the displaced intracapsular hip fracture? An unanswered question

Modular bipolar prostheses were developed to address the problems of loosening, cartilage wear, and protrusio which were seen with single unit endoprostheses. Modular unipolar prostheses address many of these problems and are significantly less expensive than the bipolar prosthesis. Recent data suggest that use of the modular unipolar prosthesis is indicated in elderly patients with low demands.     

Prognosis one year after hip fracture

This study evaluates the demography and health in a hip fracture population, and predictors of outcome one year after the fractures occurred. Physical, mental and social functioning in 109 patients who were referred from home with hip fractures were assessed retrospectively; during the hospital stay, at discharge, and after 4 and 12 months. Mobility, Katz' ADL-index and a short-version of MMSE were used in assessing their physical and mental conditions. No essential changes were found in either demography or health. The most significant predictors of outcome were age, prefracture mobility and post-fracture mental status. The proportion of patients suffering from acute confusion was considerable. The result was a higher risk of mortality, institutionalisation and poor physical outcome. It is important to pay more attention to the prevention and treatment of cases involving acute confusion.     

Changes in femoral cortical dimensions after uncemented revision hip arthroplasty. Radiological results with the porous-coated bi-metric femoral stem prosthesis in 15 asymptomatic cases

The radiographic results of 15 uncemented femoral revisions after a minimum follow-up period of 2 years are reported. Digital imaging was used to quantify the remodeling of the cortical bone. A method using computer-assisted video densitometry was developed and radiographs were scanned and digitized by a computer. The femoral cortex in five regions, as well as the endosteal diameter, was determined. After rearthroplasty, there was a significant loss in cortical bone with widening of the medullary canal. The periosteal diameter did not change. This endosteal resorption could contribute to further aseptic loosening. In addition, it could be an explanation of the primary prosthetic failure; one mode of failure could be an accelerated rate of endosteal expansion in a subgroup of the general population after hip arthroplasty.     

Experimental protocol for mechanical characterization of a femoral implant of carbon-Peek composite hip prosthesis in fatigue

This study concerns the fatigue behavior of a C/Peek hip implant. It is now well-established that the extent of bone loss around a total hip arthroplasty stem is related to stress shielding process. Due to a modulus mismatch between the bone and the implant material, the load transfer to the stem decreases the mechanical stimulus needed by the bone to maintain its structure. Because of its low modulus of elasticity and its good resistance to fatigue in aeronautical applications, the Fiber Carbon/Peek composite could potentially replace some of the metal alloys used in hip stem implant. After a literature survey on biomechanical performances of some fiber carbon composites, including AS4/Peek, experimental quasi-static and fatigue compression tests have been performed on AS4/Peek hip implants. The structural and mechanical characterization of the injection moulded composite material has been realized. The prosthesis compression and fatigue behaviour have been studied with a joint-stimulating apparatus immersed in a physiological solution temperature controlled. Instead of the low specimen homogeneity, no fatigue damage has been revealed either by X-ray observations of stiffness measurements, till ten millions of cycles. The quasi-static compressive fracture morphology has been analyzed by S.E.M. and have shown a good fiber matrix bonding. This mechanical results would suggest that AS4/Peek hip stem are worthy of further investigation as implantable prostheses.     

Functional outcome after hip fracture in Japan

One thousand one hundred sixty-nine elderly Japanese patients who sustained a hip fracture were observed prospectively. Ninety-two percent had operative fracture treatment. Hospital length of stay averaged 67 days; 81% of patients were discharged to their place of residence where they resided before sustaining the fracture. Mortality rates at 120 days, 1 year, and 2 years after injury were 6%, 11%, and 19%, respectively. At 1-year followup, ambulatory status was recovered to that of the level experienced before injury in 67% of patients.     

Mechanical failure of the intramedullary hip screw in a subtrochanteric femoral fracture

The Gamma nail, an implant specifically designed for intertrochanteric and subtrochanteric femoral fractures, has been criticized for its high risk of secondary shaft fractures. A modified design, the intramedullary hip screw has recently been introduced to correct this complication. We present a case of mechanical failure of this new implant that occurred in a pathological subtrochanteric fracture. The centering sleeve of the implant became loose and migrated while the head screw penetrated the acetabulum. Refixation was successful.     

Cost analysis of early discharge after hip fracture

OBJECTIVE: To ascertain the economic impact of an early discharge scheme for hip fracture patients. DESIGN: Population based study comparing costs of care for patients who had "hospital at home" as an option for rehabilitation and those who had no early discharge service available in their area of residence. SETTING: District hospital orthopaedic and rehabilitation wards and community hospital at home scheme. PATIENTS: 1104 consecutively admitted patients with fractured neck of femur. 24 patients from outside the district were excluded. MAIN OUTCOME MEASURES: Cost per patient episode and number of bed days spent in hospital. RESULTS: Patients with the hospital at home option spent significantly less time as inpatients (mean of 32.5 v 41.7 days; p < 0.001). Those patients who were discharged early spent a mean of 11.5 days under hospital at home care. The total direct cost to the health service was significantly less for those patients with access to early discharge than those with no early discharge option (4884 pounds v 5606 pounds; p = 0.048). CONCLUSIONS: About 40% of patients with fractured neck of femur are suitable for early discharge to a scheme such as hospital at home. The availability of such a scheme leads to lower direct costs of rehabilitative care despite higher readmission costs. These savings accrue largely from shorter stays in orthopaedic and geriatric wards.     

Radiographic course after acetabuloplasty and femoral osteotomy in hip dysplasia

The radiographic course of 101 hips with residual dysplasia treated with roof plasty combined with intertrochanteric varus derotation osteotomy using the osteotomy wedge as a roof graft after Mittelmeier were reviewed. The average followup period was 8.8 years. The acetabular angle was improved by an average of 16 degrees (postoperative mean, 19 degrees; average at followup, 18 degrees). The center edge angle also was improved by 16 degrees and was stable at 25 degrees average at followup. The neck shaft angle, abnormal in 70% of hips preoperatively, was reduced by the varus osteotomies to a mean of 111 degrees and showed a spontaneous postoperative increase to normal values of an average of 129 degrees. There was no correlation of the postoperative of the neck shaft angle to patient age, preoperative valgus extension, correction angle, or length of followup. In nearly all cases, an almost anatomic joint shape was achieved. With a complication rate of only 1%, especially regarding the rate of necroses of the femoral head, the presented surgical technique can be recommended as highly effective, reliable, and safe for the treatment of congenital hip dislocation.     

Temporary antibiotic-loaded cemented prosthesis for two-stage septic hip arthroplasty

BACKGROUND AND OBJECTIVES: Myofascial pain is the leading cause of chronic low back pain and in most cases can be successfully resolved with trigger point injections of local anesthetics. This type of pain can exist during pregnancy and exceed the analgesia provided by an epidural for labor. METHODS: A 31-year-old primiparous woman received an epidural infusion for labor analgesia. Despite complete resolution of labor pain and a solid, bilateral T10 block, the patient reported discomfort at two discrete locations in her right lumbar paraspinous muscle. RESULTS: The administration of local anesthetic via trigger point injections resulted in successful palliation of the myofascial pain. CONCLUSIONS: Myofascial pain can be an etiology of back pain in the parturient. Trigger point injections, even when used concomitantly with a functioning epidural infusion, can be a valuable aid for the provision of complete analgesia.     

Automated evaluation of hip axis length for predicting hip fracture

The hip axis length has been shown in previous studies to be predictive of hip fracture independent of age and femoral bone density. The first studies of hip axis length were performed by manual measurement of dual x-ray absorptiometry (DXA) scan printouts. In this study, an automated analysis procedure is defined using software tools provided by the DXA manufacturer. Manual and automatic hip axis length measurements in 198 women were highly correlated (r = 0.98). Because of scaling factors of the printout, the automatic measurement was 58% longer than the manual value. Precision of the automatic measurement, based upon triplicate DXA scans of 33 women, was 0.07 cm or 0.68%. To define normative data, the hip axis length was measured from femoral DXA scans of 471 female volunteers aged 40-92 scanned on 14 different Hologic QDR-1000 systems. Mean hip axis length was 10.5 cm, with a standard deviation of 0.62 cm. No significant relationship between hip axis length and age was found (r = 0.07, P = 0.15). Based on previously reported odds ratios corrected for femoral bone density, age, height, and weight, an automatic hip axis length measurement of 11.0 cm is associated with a twofold increase in hip fracture risk compared with a woman with an average hip axis length. A hip axis length value of 11.6 cm increases hip fracture risk by a factor of 4 compared with a woman with a normal hip dimension. We conclude that the hip axis length can be easily incorporated into existing DXA hip analysis software in combination with a bone density measurement.(ABSTRACT TRUNCATED AT 250 WORDS)