Tet Sen Howe

Subtrochanteric insufficiency fractures in patients on alendronate therapy: A CAUTION

We carried out a retrospective review over ten months of patients who had presented with a low-energy subtrochanteric fracture. We identified 13 women of whom nine were on long-term alendronate therapy and four were not. The patients treated with alendronate were younger, with a mean age of 66.9 years (55 to 82) vs 80.3 years (64 to 92) and were more socially active. The fractures sustained by the patients in the alendronate group were mainly at the femoral metaphyseal-diaphyseal junction and many had occurred after minimal trauma. Five of these patients had prodromal pain in the affected hip in the months preceding the fall, and three demonstrated a stress reaction in the cortex in the contralateral femur. Our study suggests that prolonged suppression of bone remodelling with alendronate may be associated with a new form of insufficiency fracture of the femur. We believe that this finding is important and indicates the need for caution in the long-term use of alendronate in the treatment of osteoporosis.

An emerging pattern of subtrochanteric stress fractures: A long-term complication of alendronate therapy?*

BACKGROUND Subtrochanteric insufficiency fractures in post-menopausal patients have not been commonly reported in the literature. A recent increase in the incidence of such fractures occurring in patients while on alendronate therapy led us to conduct a retrospective review of these patients in our institution. METHODS Seventeen patients, with a mean age of 66 years, sustained low energy subtrochanteric fractures within a 20-month period. These patients were incidentally found to be on alendronate therapy for an average of 4.8 years. Clinical data and history were reviewed and roentgenograms were evaluated by a single investigator. All additional imaging and bone mineral density measurements available were analysed. RESULTS A characteristic fracture configuration suggestive of an insufficiency stress fracture was identified on plain radiographs. This consisted of (a) cortical thickening in the lateral side of the subtrochanteric region, (b) a transverse fracture, and (c) a medial cortical spike. In addition, 9 (53%) patients had bilateral findings of stress reactions or fractures, and 13 (76%) had symptoms of prodromal pain. CONCLUSIONS These insufficiency fractures could possibly have developed from the over suppression of bone turnover from prolonged alendronate therapy, in keeping with recently published evidence. This study further highlights the need for heightened awareness of alendronates potential adverse effects.

Femoral cortical stress lesions in long-term bisphosphonate therapy: a herald of impending fracture?

Objective: Lateral cortical stress reactions have been documented to precede femoral insufficiency fractures after long-term bisphosphonate therapy. We studied the natural history of femoral stress lesions associated with long-term bisphosphonate therapy. Design and Setting: A retrospective clinical and radiologic review of all patients with radiologically documented femoral stress lesions associated with bisphosphonate therapy was carried out in a tertiary center involved with geriatric trauma care. Patients: Of 1463 geriatric hip fractures occurring from May 1, 2004, to July 31, 2008, 33 were of a distinct metaphyseal-diaphyseal configuration. Thirty-two were on prior bisphosphonate therapy. Sixteen femurs showed a lateral cortical thickening either on prefracture radiographs (four femurs) or on radiographs of the contralateral femur (12 femurs). Main Outcome Measures: Features that predispose to complete stress fractures were determined. The intact femurs were followed up for symptomatic and radiologic progression and occurrence of new lesions. Results: All four cases that fractured had a “dreaded black line” in the lesion, whereas only 1 of 12 patients had this fracture in femurs which remained intact (100% versus 8.3%, P = 0.003). All patients who fractured reported thigh discomfort over 1 month (range, 0.1-9.0 months; standard deviation, 4.0 months), whereas three of 12 patients who did not fracture reported thigh discomfort (100% versus 25%, P = 0.019). In the remaining patients, eight patients were asymptomatic, two patients had reduced symptoms, and one patient had persistent thigh pain at 23.0 months (range, 5-35 months; standard deviation, 10.2 months). One patient was too demented for symptomatic assessment. No patient developed a new lesion. Radiologic stabilization of the lateral cortical thickening was evident on follow-up radiographs. Conclusion: Cortical stress reactions associated with prolonged antiresorptive therapy, in the presence of pain and the “dreaded black line,” have an increased risk for complete stress fractures.

Automatic extraction of femur contours from hip x-ray images

Extraction of bone contours from x-ray images is an important first step in computer analysis of medical images. It is more complex than the segmentation of CT and MR images because the regions delineated by bone contours are highly nonuniform in intensity and texture. Classical segmentation algorithms based on homogeneity criteria are not applicable. This paper presents a model-based approach for automatically extracting femur contours from hip x-ray images. The method works by first detecting prominent features, followed by registration of the model to the x-ray image according to these features. Then the model is refined using active contour algorithm to get the accurate result. Experiments show that this method can extract the contours of femurs with regular shapes, despite variations in size, shape and orientation.

Fasciotomy and Surgical Tenotomy for Recalcitrant Lateral Elbow Tendinopathy Early Clinical Experience With a Novel Device for Minimally Invasive Percutaneous Microresection

Background: The optimal choice for intervention for recalcitrant lateral elbow tendinopathy remains unclear as various treatment modalities have documented comparable results in the literature. Purpose: To explore the safety, tolerability, and early efficacy of a new minimally invasive mode of treatment that delivers focused, calibrated ultrasonic energy, effectively microresecting the pathological tendon and removing only pathological tissue. Study Design: Case series; Level of evidence, 4. Methods: Seven male and 13 female patients aged 33 to 65 years averaging 12.5 months (range, 4-48) of failed nonoperative therapy underwent the ultrasonic microresection procedure in an outpatient clinic setting. The procedure involved a sterile, ultrasound-guided percutaneous microresection with a proprietary device (TX1) performed through a stab incision under local anesthesia. The duration of the procedure and complications of the device or procedure were assessed. Outcome parameters included patient satisfaction; visual analog scale (VAS) pain scores; Disabilities of the Arm, Shoulder and Hand (DASH) scores at 1, 3, 6, and 12 months; and ultrasound assessment at 3 and 6 months. Results: The median duration for the sterile confirmatory ultrasound examination (phase 1) was 88.5 seconds (range, 39-211; SD, ±47.6), the median duration of the procedure proper (phase 2) was 10.1 minutes (range, 4.1-19.4; SD, ±3.7), and the median energy time (duration the TX1 device was activated) was 32.5 seconds (range, 18-58; SD, ±11.0). No complications were encountered. A significant improvement in VAS score (from 5.5 to 3.3; P < .001) occurred by 1 week, and significant improvements in both DASH-Compulsory (from 21.7 to 11.3; P = .001) and DASH-Work (from 25.0 to 6.3; P = .012) scores occurred by 1 month. The VAS scores further improved at 3, 6, and 12 months (from 2.0 to 1.0 to 0.50; P = .003 and .023). The DASH-Compulsory score improved significantly from 3 to 6 months (from 8.6 to 4.6; P = .003), and both the DASH-Compulsory and DASH-Work scores were sustained by 12 months. Sonographically reduced tendon thickness (19 patients), resolved or reduced hypervascularity (17 patients), and reduced hypoechoic area (18 patients) occurred by 6 months. Nineteen of the 20 patients (95%) expressed satisfaction with the procedure, with 9 patients being very satisfied with their overall experience at 6 months after the procedure, 10 patients somewhat satisfied, and 1 patient neutral. Conclusion: Ultrasonic microresection of diseased tissue with the TX1 device provides a focally directed, safe, specific, minimally invasive, and well-tolerated treatment for recalcitrant lateral elbow tendinopathy in an office-based or ambulatory surgical setting with good evidence of some level of efficacy in 19 of 20 patients (95%) that is sustained for at least 1 year.

Post-operative outcomes of atypical femoral subtrochanteric fracture in patients on bisphosphonate therapy

Management of bisphosphonate-associated subtrochanteric fractures remains opinion- or consensus-based. There are limited data regarding the outcomes of this fracture. We retrospectively reviewed 33 consecutive female patients with a mean age of 67.5 years (47 to 91) who were treated surgically between May 2004 and October 2009. The mean follow-up was 21.7 months (0 to 53). Medical records and radiographs were reviewed to determine the post-operative ambulatory status, time to clinical and radiological union and post-fixation complications such as implant failure and need for second surgery. The predominant fixation method was with an extramedullary device in 23 patients. 25 (75%) patients were placed on wheelchair mobilisation or no weight-bearing initially. The mean time to full weight-bearing was 7.1 months (2.2 to 29.7). The mean time for fracture site pain to cease was 6.2 months (1.2 to 17.1). The mean time to radiological union was 10.0 months (2.2 to 27.5). Implant failure was seen in seven patients (23%, 95 confidence interval (CI) 11.8 to 40.9). Revision surgery was required in ten patients (33%, 95 CI 19.2 to 51.2). A large proportion of the patients required revision surgery and suffered implant failure. This fracture is associated with slow healing and prolonged post-operative immobility.

Computing Neck-Shaft Angle of Femur for X-Ray Fracture Detection

Worldwide, 30% – 40% of women and 13% of men suffer from osteoporotic fractures of the bone, particularly the older people. Doctors in the hospitals need to manually inspect a large number of x-ray images to identify the fracture cases. Automated detection of fractures in x-ray images can help to lower the workload of doctors by screening out the easy cases, leaving a small number of difficult cases and the second confirmation to the doctors to examine more closely. To our best knowledge, such a system does not exist as yet. This paper describes a method of measuring the neck-shaft angle of the femur, which is one of the main diagnostic rules that doctors use to determine whether a fracture is present at the femur. Experimental tests performed on test images confirm that the method is accurate in measuring neck-shaft angle and detecting certain types of femur fractures.

Combining classifiers for bone fracture detection in X-ray images

In medical applications, sensitivity in detecting medical problems and accuracy of detection are often in conflict. A single classifier usually cannot achieve both high sensitivity and accuracy at the same time. Methods of combining classifiers have been proposed in the literature. This paper presents a study of probabilistic combination methods applied to the detection of bone fractures in X-ray images. Test results show that the effectiveness of a method in improving both accuracy and sensitivity depends on the nature of the method as well as the proportion of positive samples.

Detecting femur fractures by texture analysis of trabeculae

30% of women and 13% of men worldwide suffer from osteoporotic bone fractures worldwide. In large hospitals, doctors need to visually inspect a large number of X-ray images to identify the fracture cases, which typically constitute about 12% of all the X-ray images examined. Automated fracture detection can help to screen for obvious cases and flag suspicious cases for closer examinations. This paper describes a method of detecting femur fractures by analyzing trabecular texture patterns. Test results show that it is more accurate than an existing method based on neck-shaft angle. Moreover, combining the methods further improve the overall performance of fracture detection.

Atypical femoral stress fractures in bisphosphonate-free patients

The long-term safety of bisphosphonates has been questioned in case series [1, 2] in which atypical femoral stress fractures has been seen with its prolonged use. Atypical femoral stress fractures have distinctive radiographic characteristics: transverse or short oblique configuration, associated with focal or diffuse cortical thickening, so-called “beaking”. However we identified four patients (five fractures) from our series of 50 patients (8%) who fulfilled these radiographic pattern but who were never put on bisphosphonates. The ages of the cases were 50, 53, 66, 70 and 78 years at time of fracture. Two patients had normal BMD, one patient (with bilateral atypical fractures) was osteopenic, and one patient did not have BMD available. In all these patients, there were no prodromal symptoms, no history of hormonal therapy and their 25-hydroxyvitamin D measurements were normal (range 21.9–26.1 ug/L). They had no history of renal impairment, steroids usage or any endocrinological dysfunction (except one patient who had diabetes mellitus). One patient had breast cancer treated more than 20 years ago. Her procollagen type 1 amino-terminal propeptide level was