The Effect on the Fracture Healing following Femoral Neck Shortening after Osteoporotic Femoral Neck Fracture Treated with Internal Fixation: Finite Element Analysis.

OBJECTIVE: To evaluate the stress status of fracture site caused by femoral neck shortening and to analyze the stress of fracture site and the implants from the finite element point of view. METHODS: CT scan data of hip of a normal adult female were collected. Three-dimensional reconstruction MICs and related module function simulation was used to establish the postoperative shortening model of femoral neck fracture with Pauwels angle > 50°, which was treated with cannulated screws. The models were divided into four groups: normal femoral neck, shortening in 2.5 mm, shortening in 7.5 mm, and shortening in 12.5 mm. The finite element analysis software msc.nastran2012 was used, and the data of maximum stress and stress nephogram of fracture site and implants were carried out. RESULTS: From normal femoral neck to shortening in 12.5 mm of the femoral neck, the maximum tensile stress increased gradually in the fracture site above the cannulated screws while compressive stress decreased gradually in the fracture site below the cannulated screws, and the maximum stress of the cannulated screws increased gradually with obvious stress concentration at the screw holes in the fracture site, and the peak value of stress concentration was about 179 MPa. CONCLUSION: The biomechanical environment of the fracture site changed by femoral neck shortening. With the increasing of femoral neck shortening, the stress of the fracture site and implants would be uneven; then, the stability of fracture site would become worse, and the possibility of implant sliding or even breakage would be increased.

12-Month Teriparatide Treatment Reduces New Vertebral Compression Fractures Incidence And Back Pain And Improves Quality Of Life After Percutaneous Kyphoplasty In Osteoporotic Women.

PURPOSE: Define the effectiveness of teriparatide (TPTD) treatment on reducing the incidence of new vertebral compression fractures (NVCFs) and back pain and improving quality of life after percutaneous kyphoplasty (PKP). METHODS: Two years of clinical follow-up data from primary osteoporotic women who had experienced initial osteoporotic vertebral compression fractures (OVCFs) and received PKP plus 12-month TPTD (n=113) or basic treatment (BT) of calcium and vitamin D supplements (n=208) were retrospectively collected. The risk of NVCFs over each 6-month period in the TPTD group was evaluated and compared with the BT group using a logistic regression. Health-related quality of life (HRQoL, EQ-5D questionnaire), back pain [100 mm visual analog scale (VAS)] and bone mineral density (BMD) of the spine were analyzed using linear mixed models for repeated measures (LMMRM). RESULTS: Logistic regression analysis adjusting for baseline characteristics showed that patients in the TPTD group had a lower risk of NVCFs compared with those receiving BT during the final three observation intervals (6-12 months, OR=0.189, 95% CI=0.030-0.681, p=0.046; 12-18 months, OR=0.009, 95% CI=0.0001-0.111, p=0.001; 18-24 months, OR=0.024, 95% CI=0.0009-0.264, p=0.009, respectively). Significant improvements in adjusted EQ-5D and back pain VAS scores were identified in the TPTD group compared with the BT group, and this improvement was sustained for at least 12 months after teriparatide treatment was discontinued (both p<0.001). The BMD of the spine also showed a higher T-value in the TPTD group compared with the BT group (p<0.001). CONCLUSION: In routine clinical practice, for patients with OVCFs who receive the PKP procedure, TPTD treatment may be a preferable subsequent therapy because of its ability to reduce the incidence of NVCFs and sustain a high quality of life and back pain alleviation.

Applying vibration in early postmenopausal osteoporosis promotes osteogenic differentiation of bone marrow-derived mesenchymal stem cells and suppresses postmenopausal osteoporosis progression.

We aimed to evaluate whether applying low magnitude vibration (LMV) in early postmenopausal osteoporosis (PMO) suppresses its progression, and to investigate underlying mechanisms. Rats were randomly divided into Sham (Sham-operated), Sham+V, OVX (ovariectomized), OVX+E2 (estradiol benzoate), OVX+V (LMV at 12-20 weeks postoperatively), and OVX+Vi (LMV at 1-20 weeks postoperatively) groups. LMV was applied for 20 min once daily for 5 days weekly. V rats were loaded with LMV at 12-20 weeks postoperatively. Vi rats were loaded with LMV at 1-20 weeks postoperatively. Estradiol (E2) rats were intramuscularly injected at 12-20 weeks postoperatively once daily for 3 days. The bone mineral densities (BMDs), biomechanical properties, and histomorphological parameters of tibiae were analyzed. In vitro, rat bone marrow-derived mesenchymal stem cells (rBMSCs) were subjected to LMV for 30 min daily for 5 days, or 17ß-E2 with or without 1-day pretreatment of estrogen receptor (ER) inhibitor ICI 182,780 (ICI). The mRNA and protein expresion were performed. Data showed that LMV increased BMD, bone strength, and bone mass of rats, and the effects of Vi were stronger than those of E2. In vitro, LMV up-regulated the mRNA and protein expressions of Runx2, Osx, Col I, and OCN and down-regulated PPARγ, compared with E2. The effects of both LMV and E2 on rBMSCs were inhibited by ICI. Altogether, LMV in early PMO suppresses its progression, which is associated with osteogenic differentiation of rBMSCs via up-regulation of ERα and activation of the canonical Wnt pathway. LMV may therefore be superior to E2 for the suppression of PMO progression.

Kyphoplasty vs conservative treatment: a case-control study in 110 post-menopausal women population. Is kyphoplasty better than conservative treatment?

OBJECTIVE: Osteoporosis is a highly prevalent disease worldwide. Consequences of vertebral osteoporotic fractures include pain and progressive vertebral collapse resulting in spinal kyphosis, decreased quality of life, disability and mortality. Minimally invasive procedures represent an advance to the treatment of osteoporotic VCFs. Despite encouraging results reported by many authors, surgical intervention in an osteoporotic spine is fraught with difficulties. Advanced patients age and comorbidities are of great concern. PATIENTS AND METHODS: We designed a retrospective case-control study on 110 post-menopausal women consecutively visited at our institution. Study population was split in a surgical and a conservative cohort, according to the provided treatment. RESULTS: Kyphoplasty treated patients had lower back pain VAS scores at 1 month as compared with conservatively treated patients (p < 0.05). EQ5D validated questionnaire also showed a better quality of life at 1 month for surgically treated patients (p < 0.05). SF-12 scores showed greater improvements at 1 month and 3 months with statistically significant difference between the two groups just at 3 months (p < 0.05). At 12 months, scores from all scales were not statistically different between the two cohorts, although surgically treated patients showed better trends than conservatively treated patients in pain and quality of life. Kyphoplasty was able to restore more than 54.55% of the original segmental kyphosis, whereas patients in conservative cohort lost 6.67% of the original segmental kyphosis on average. CONCLUSIONS: Kyphoplasty is a modern minimal invasive surgery, allowing faster recovery than bracing treatment. It can avoid the deformity in kyphosis due to VCF. In fact, the risk to develop a new vertebral fracture after the first one is very high.

A rare presentation of subclinical Cushing's syndrome as a pubic fracture.

Osteoporosis and bone fractures are commonly seen in patients with Cushing's syndrome (CS). Fractures usually occur in the vertebrae and ribs whereas pubic fractures are less common. Similar to obvious hypercortisolemia, subclinical hypercortisolemia can increase the risk of fractures. However, in subclinical cases, bone fractures are very rarely seen as the presenting symptom. We herein report the case of a 62-year-old postmenopausal woman who was presented with a pubic fracture. During the evaluation of the fracture, thoracoabdominal magnetic resonance imaging of the patient demonstrated an adrenal mass. Although the patient did not show any signs of overt hypercortisolism, an endocrinologic evaluation revealed hypercortisolism due to an adrenal tumor. Adrenalectomy was performed, which resulted in a cure of the disease. During the orthopedic follow-up, the patient's pubic area pain gradually improved, and the pubic fracture healed without any accompanying new bone fractures. One year after the surgery, a remarkable improvement was detected in the patient's bone density in spite of the lack of administration of any medications for osteoporosis. Subclinical CS can present as a pubic fracture, and awareness of this relationship can help physicians to diagnose the disease.

Teriparatide increases the insertional torque of pedicle screws during fusion surgery in patients with postmenopausal osteoporosis.

OBJECT: The object of this study was to examine the efficacy of preoperative teriparatide treatment for increasing the insertional torque of pedicle screws during fusion surgery in postmenopausal women with osteoporosis. METHODS: Fusion surgery for the thoracic and/or lumbar spine was performed in 29 postmenopausal women with osteoporosis aged 65-82 years (mean 72.2 years). The patients were divided into 2 groups based on whether they were treated with teriparatide (n = 13) or not (n = 16) before the surgery. In the teriparatide-treated group, patients received preoperative teriparatide therapy as either a daily (20 µg/day, n = 7) or a weekly (56.5 µg/week, n = 6) injection for a mean of 61.4 days and a minimum of 31 days. During surgery, the insertional torque was measured in 212 screws inserted from T-7 to L-5 and compared between the 2 groups. The correlation between the insertional torque and the duration of preoperative teriparatide treatment was also investigated. RESULTS: The mean insertional torque value in the teriparatide group was 1.28 ± 0.42 Nm, which was significantly higher than in the control group (1.08 ± 0.52 Nm, p < 0.01). There was no significant difference between the daily and the weekly teriparatide groups with respect to mean insertional torque value (1.34 ± 0.50 Nm and 1.18 ± 0.43 Nm, respectively, p = 0.07). There was negligible correlation between insertional torque and duration of preoperative teriparatide treatment (r(2) = 0.05, p < 0.01). CONCLUSIONS: Teriparatide injections beginning at least 1 month prior to surgery were effective in increasing the insertional torque of pedicle screws during surgery in patients with postmenopausal osteoporosis. Preoperative teriparatide treatment might be an option for maximizing the purchase of the pedicle screws to the bone at the time of fusion surgery.

Phloretin promotes osteoclast apoptosis in murine macrophages and inhibits estrogen deficiency-induced osteoporosis in mice.

Bone-remodeling imbalance induced by increased osteoclast formation and bone resorption is known to cause skeletal diseases such as osteoporosis. The reduction of estrogen levels at menopause is one of the strongest risk factors developing postmenopausal osteoporosis. This study investigated osteoprotective effects of the dihydrochalcone phloretin found in apple tree leaves on bone loss in ovariectomized (OVX) C57BL/6 female mice as a model for postmenopausal osteoporosis. OVX demoted bone mineral density (BMD) of mouse femurs, reduced serum 17ß-estradiol level and enhanced serum receptor activator of NF-κB ligand (RANKL)/osteoprotegerin ratio with uterine atrophy. Oral administration of 10 mg/kg phloretin to OVX mice for 8 weeks improved such effects, compared to sham-operated mice. Phloretin attenuated TRAP activity and cellular expression of ß3 integrin and carbonic anhydrase II augmented in femoral bone tissues of OVX mice. This study further examined that osteogenic activity of phloretin in RANKL-differentiated Raw 264.7 macrophages into mature osteoclasts. Phloretin at 1-20 µM stimulated Smac expression and capase-3 activation concurrently with nuclear fragmentation of multi-nucleated osteoclasts, indicating that this compound promoted osteoclast apoptosis. Consistently, phloretin enhanced bcl-2 induction but diminished bax expression. Furthermore, phloretin activated ASK-1-diverged JNK and p38 MAPK signaling pathways in mature osteoclasts, whereas it dose-dependently inhibited the RANKL-stimulated activation of ERK. Therefore, phloretin manipulated ASK-1-MAPK signal transduction leading to transcription of apoptotic genes. Phloretin was effective in preventing estrogen deficiency-induced osteoclastogenic resorption.

BMP-2 induced early bone formation in spine fusion using rat ovariectomy osteoporosis model.

BACKGROUND CONTEXT: Bone morphogenetic proteins (BMPs) enhance bone formation. Numerous animal studies have established that BMPs can augment spinal fusion. However, there is a lack of data on the effect of BMP-2 on spinal fusion in the osteoporotic spine. PURPOSE: To investigate whether recombinant human BMP-2 (rhBMP-2) enhances spine fusion in an ovariectomized rat model. STUDY DESIGN: In vivo animal study. METHODS: Female Sprague-Dawley rats (n=60) were ovariectomized or sham operated and randomized into three groups: Sham (sham operated+fusion), ovariectomy (OVX) (OVX+fusion), and BMP (OVX+fusion+BMP-2). Six weeks after ovariectomy, unilateral lumbar spine fusion was performed using autologous iliac bone with/without rhBMP-2 delivered on a collagen matrix. For each group, gene expression and histology were evaluated at 3 and 6 weeks after fusion, and bone parameters were measured by microcomputed tomography at 3, 6, 9, and 12 weeks. RESULTS: Real-time reverse-transcription polymerase chain reaction at 3 weeks showed markedly increased expression of osteoblast-related markers (namely alkaline phosphatase, osteocalcin, Runx2, Smad1, and Smad5) in the BMP group compared with the other groups (p=.0005, .0005, .003, .009 and .012, respectively). Although the Sham and OVX groups showed both sparse and compacted bones between transverse processes at 6 weeks, the BMP group had a significantly larger bone mass within the fusion bed at 3 weeks and later. All rats in the BMP group had bridging bone at 3 weeks; at 12 weeks, bridging bones in the Sham and OVX groups were about 50% and 25%, respectively, of that in the BMP group. CONCLUSIONS: Recombinant human BMP-2 enhances spinal fusion in OVX rats and acts during early bone formation. Therapeutic BMP-2 may therefore improve the outcome of spinal fusion in the osteoporotic patient.

Vertebroplasty increases compression of adjacent IVDs and vertebrae in osteoporotic spines.

BACKGROUND CONTEXT: Approximately 25% of vertebroplasty patients experience subsequent fractures within 1 year of treatment, and vertebrae adjacent to the cemented level are up to three times more likely to fracture than those further away. The increased risk of adjacent fractures postaugmentation raises concerns that treatment of osteoporotic compression fractures with vertebroplasty may negatively impact spine biomechanics. PURPOSE: To quantify the biomechanical effects of vertebroplasty on adjacent intervertebral discs (IVDs) and vertebral bodies (VBs). STUDY DESIGN: A biomechanics study was conducted using cadaveric thoracolumbar spinal columns from elderly women (age range, 51-98 years). METHODS: Five level motion segments (T11-L3) were assigned to a vertebroplasty treated or untreated control group (n=10/group) such that bone mineral density (BMD), trabecular architecture, and age were similar between groups. Compression fractures were created in the L1 vertebra of all specimens, and polymethylmethacrylate bone cement was injected into the fractured vertebra of vertebroplasty specimens. All spine segments underwent cyclic axial compression for 115,000 cycles. Microcomputed tomography imaging was performed before and after cyclic loading to quantify compression in adjacent VBs and IVDs. RESULTS: Cyclic loading increased strains 3% on average in the vertebroplasty group when compared with controls after 115,000 cycles. This global strain manifested locally as approximately fourfold more compression in the superior VB (T12) and two- to fourfold higher axial and circumferential deformations in the superior IVD (T12-L1) of vertebroplasty-treated specimens when compared with untreated controls. Low BMD and high cement fill were significant factors that explained the increased strain in the vertebroplasty-treated group. CONCLUSIONS: These data indicate that vertebroplasty alters spine biomechanics resulting in increased compression of adjacent VB and IVD in severely osteoporotic women and may be the basis for clinical reports of adjacent fractures after vertebroplasty.

A physiologically based pharmacokinetic model for strontium exposure in rat.

PURPOSE: To develop a physiologically based pharmacokinetic (PBPK) model to describe the disposition of Strontium--a bone seeking agent approved in 2004 (as its Ranelate salt) for treatment of osteoporosis in post-menopausal women. METHODS: The model was developed using plasma and bone exposure data obtained from ovariectomised (OVX) female rats--a preclinical model for post-menopausal osteoporosis. The final PBPK model incorporated elements from literature models for bone seeking agents allowing for description of the heterogeneity of bone tissue and also for a physiological description of bone remodelling processes. The model was implemented in MATLAB in open and closed loop configurations, and fittings of the model to exposure data to estimate certain model parameters were carried out using nonlinear regression, treating data with a naïve-pooled approach. RESULTS: The PBPK model successfully described plasma and bone exposure of Strontium in OVX rats with parameter estimates and model behaviour in keeping with known aspects of the distribution and incorporation of Strontium into bone. CONCLUSIONS: The model describes Strontium exposure in a physiologically rationalized manner and has the potential for future uses in modelling the PK-PD of Strontium, and/or other bone seeking agents, and for scaling to model human Strontium bone exposure.

How far above the true anatomic position can the acetabular cup be placed in total hip arthroplasty?

INTRODUCTION: There is controversy about which is more suitable for determining correct socket position in patients with severe bone deficiency of the acetabular roof because of developmental dysplasia of the hip (DDH): the anatomic centre of hip rotation or a high centre. 
 METHOD: We evaluated the relationship, in 200 hips, between the centre of rotation and presence of the Trendelenburg sign to determine the upper limit of cup position from the standpoint of hip-abductor strength. 
 RESULTS: Of the 200 hips, 20 (10%) showed a positive Trendelenburg sign. There were no statistically significant differences between parameters (the centre of rotation, femoral offset, abductor lever arm) regarding the presence of the Trendelenburg sign except for age at surgery. Patients with a positive Trendelenburg sign were significantly older (64.1 ± 9.4 years) than those with a negative Trendelenburg sign (58.8 ± 7.7 years) (P = 0.01).
 CONCLUSIONS: Our findings indicate that a high centre of hip rotation of up to approximately 30 mm from the inter-teardrop line is a feasible option for patients with DDH from the standpoint of hip-abductor strength if stems are used that allow the restoration of femoral offset and the abductor lever arm.

Teriparatide accelerates lumbar posterolateral fusion in women with postmenopausal osteoporosis: prospective study.

STUDY DESIGN: Prospective trial. OBJECTIVE: To examine the clinical efficacy of teriparatide for bone union after instrumented lumbar posterolateral fusion using local bone grafting in women with postmenopausal osteoporosis. SUMMARY OF BACKGROUND DATA: Intermittent parathyroid hormone (PTH) treatment increases bone mass and reduces the risk for osteoporotic vertebral fractures. Recombinant human PTH (1-34) has already been approved as a treatment for severe osteoporosis. Preclinical data support the efficacy of PTH for lumbar spinal fusion. However, clinical results of PTH for spinal fusion have not yet been reported. METHODS: Fifty-seven women with osteoporosis diagnosed with degenerative spondylolisthesis were divided into 2 treatment groups, a teriparatide group (n = 29; daily subcutaneous injection of 20 µg of teriparatide) and a bisphosphonate group (n = 28; weekly oral administration of 17.5 mg of risedronate). All patients underwent decompression and 1- or 2-level instrumented posterolateral fusion with a local bone graft. Fusion rate, duration of bone union, and pain scores were evaluated 1 year after surgery. RESULTS: Pain scores improved after surgery; however, no significant difference was noted between the groups after surgery. The rate of bone union was 82% in the teriparatide group and 68% in the bisphosphonate group. Average duration of bone union was 8 months in the teriparatide group and 10 months in the bisphosphonate group. The rate of bone union and average of duration of bone union in the teriparatide group patients were significantly superior to those in the bisphosphonate group. CONCLUSION: Daily subcutaneous injection of teriparatide for bone union using local bone grafting after instrumented lumbar posterolateral fusion in women with postmenopausal osteoporosis was more effective than oral administration of bisphosphonate.

Resurfacing total hip replacement--a therapeutical approach in postmenopausal women with osteoporosis and hip arthrosis.

AIM: Patients with incipient hip arthrosis may benefit from a relatively new therapeutical approach using resurfacing total hip replacement, but in those with associated osteoporosis, this type of surgical intervention is contraindicated, given the poor quality of osteoporotic bones. We assessed the efficacy of the antiosteoporotic pharmacological therapy to improve bone quality and bone strength in postmenopausal women diagnosed with hip arthrosis and osteoporosis thus facilitating the hip surgical intervention. METHODS: We evaluated 20 postmenopausal women aged between 53-60 years diagnosed with osteoporosis according to the WHO criteria, by using dual-energy X-ray absorptiometry (DXA) for bone mineral density measurements. All these patients had low hip T score (osteopenia/ osteoporosis) and also incipient hip arthrosis. The surgical approach was delayed for 12 months and all the patients received bisphosphonate therapy with calcium and vitamin D supplements. DXA scans were performed after 12 months of therapy in all the patients. RESULTS: A surgical intervention with resurfacing total hip replacement was performed in 12 of the 16 patients presenting with increasing BMD, 4 of them showing elements of rapidly advancing hip arthrosis to a stage that made this type of intervention impossible. We chose not to use this technique in the group with stable BMD (4 patients). All 12 women surgically treated had a favorable post-operative outcome without experiencing a femoral neck fracture during the surgical intervention or during the twelve-month follow-up. All 20 patients continued to receive bisphosphonate therapy. CONCLUSION: In postmenopausal women with osteoporosis and associated hip arthrosis, improving bone mass and bone quality with bisphosphonate therapy is necessary and important in order to allow hip arthroplasty, by using the technique of resurfacing, avoiding the risk of intra-operative fractures and with a favorable post-operative long-term outcome.

[Instrumental fixation in spinal surgery. Particular characteristics in patients with manifest osteoporosis]. / Wirbelsäulenchirurgische instrumentierte Versorgung. Besonderheiten bei Patienten mit manifester Osteoporose.

A number of factors need to be borne in mind in the planning and performance of instrumental fixation of the spine in patients with osteoporosis. Improved implant anchoring using special screws and cement augmentation can help to avoid implant dislocations. Nevertheless, particular attention should be paid to spinal balance in these patients.

Decrease in particle-induced osteolysis in ovariectomized mice.

Postmenopausal osteoporosis is a common disorder that results from increased osteoclastic activity caused by estrogen deficiency. Whether postmenopausal bone remodeling can alter the response to particulate debris is unknown. The purpose of this study was to evaluate the bone response to polyethylene particles in an ovariectomized murine model. Polyethylene particles were implanted onto the calvaria of seven control mice and seven ovariectomized (OVX) mice, as compared with calvaria from sham-operated and OVX mice. Calvaria were harvested after 14 days. Skulls were analyzed with a high-resolution micro-CT and by histomorphometry after staining with Stevenel blue and picrofuschine, and for tartrate-specific alkaline phosphatase. As assessed by micro-CT, particle implantation induced a significant decrease in bone thickness in control mice, while bone thickness remained stable in OVX mice. In particle-implanted animals, the osteoclast number was 2.84 +/- 0.3 in control mice and 1.74 +/- 0.22 in OVX mice. Mean bone loss was -12% +/- 1.9% in control mice and -4.7% +/- 1.7% in OVX animals. The reduction of osteolytic response suggests that ovariectomy may have a protective role against particle-induced bone resorption.

[Percutaneous vertebroplasty with only few complications--a retrospective study]. / Perkutan vertebroplastik med kun få komplikationer--et retrospektivt studie.

INTRODUCTION: Percutaneous vertebroplasty (PVP) was introduced in 1984 and has proved to be valuable in the treatment of painful vertebral lesions such as haemangiomas, metastasis, and osteoporotic fractures. According to the literature, the operation provides pain relief with only few and harmless complications. The aim of this study was to evaluate our perioperative experiences with special reference to the safety of the procedure. MATERIAL AND METHODS: A total of 156 procedures were performed in 148 patients with osteoporotic fractures. Both acute and chronic fractures were treated. All patients had plain radiographs of the spine. Magnetic resonance imaging (MRI) or bone scans were performed in case of old fractures or more than one fracture in patients with acute back-pain. At follow-up after three and 12 months, plain radiographs were performed in conjunction with physical examinations and interviews. Data were collected retrospectively. RESULTS: We identified 40.4% cemental leaks (confidence interval (CI) 32.6; 48.5). None of these resulted in neurological symptoms. One patient experienced shortness of breath after the procedure, one had atrial fibrillation, and one patient had an iatrogenic pneumothorax. In all, the frequency of symptomatic complications was 1.9% (CI -0.4; 5.5). CONCLUSION: We believe that PVP is a safe procedure with only few symptomatic complications when performed under local anaesthesia and by a specialist in transpedicular approach.

Balloon kyphoplasty combined with posterior instrumentation for the treatment of burst fractures of the spine--1-year results.

OBJECTIVE: Clinical and radiologic follow-up of patients with osteoporosis with painful, traumatic A3-type vertebral compression fractures in the thoracic and lumbar spine. DESIGN: Prospective study over the period of 1 year. SETTING: Level I Trauma Center. PATIENTS AND INTERVENTION: Twenty-five patients with osteoporosis (14 women and 11 men) and painful, traumatic A3-type fractures were treated with Balloon Kyphoplasty in combination with a short-segment posterior fixation (using the Universal Spine System). Twenty-one patients returned for their 1-year follow-up visit. X-rays were taken preoperatively, postoperatively, and at 3, 6, and 12 months' follow-up to evaluate vertebral height and local Cobb angle. Pain was measured using the self-reporting Visual Analogue pain Scale (VAS). Disability was measured using the Oswestry Disability questionnaire (ODI). RESULTS: The mean pain score (VAS) improved significantly from pretreatment to posttreatment from 7.8 +/- 2.2 (5.6-10) to 4.9 +/- 2.1 (2.8-8.0) (P < 0.001). It improved further to 2.9 +/- 1.4 (2.1-4.3) at 3 months and increased slightly after 1 year (3.8 +/- 1.9) (1.9-4.7). Limitation of daily activities (ODI) improved significantly from 88% (78-100) to 35% (15-48) at 3 months (P < 0.05). Improvement was maintained at 1 year at 36.5% (10-42). At 1-year follow-up, maintenance of the height restoration and kyphotic deformity correction was found. CONCLUSIONS: Balloon Kyphoplasty in combination with short-segment posterior instrumentation in traumatic A3 vertebral fractures led to a significant reduction in pain and disability. The combination of both surgical techniques was able to restore and maintain vertebral body height and correction of angular deformity. This technique might offer important safety advantages over an invasive anterior-posterior approach.

Subcapital femoral neck fracture after fixation of an intertrochanteric fracture with a proximal femoral nail: a report of two cases.

Subcapital femoral neck fractures are a rare complication after fixation of an intertrochanteric fracture with a proximal femoral nail. We report 2 such cases where the patients had severe osteoporosis, based on Singh's index and pathological findings. In one case there was a technical error leading to a tip-apex distance of more than 20 mm, but osteoporosis appeared to be a more significant cause than any technical problems.

Outcome of hybrid stem fixation in osteoporotic female patients. A minimum five-year follow-up study.

In osteoporotic patients cemented stems are usually used to achieve a good primary stability. However, when patients are obese or active the long-term survival of cemented prostheses is questioned. In these patients, a partially-cemented stem with a hybrid fixation could be advantageous. A hybrid stem was retrospectively evaluated at a minimum follow-up of 60 months (mean, 75 months) in 58 osteoporotic women: seventeen with a body mass index (BMI) >30 (obese), 41 with a BMI between 25 and 29.9 (overweight), and an UCLA score for activity level >6. At the latest follow up, the Harris hip score improved from 33.5 points preoperatively to 81.6 points, and the WOMAC score improved significantly. Three stems (4.9%) had an asymptomatic subsidence of less than 2.5 mm; no stem was revised. These results support the use of partially-cemented stems in heavy or active osteoporotic women.