Fragility fractures associated with osteoporosis (OP) reduce quality of life, increase risk for subsequent fractures, and are a major economic burden. In 2010, Osteoporosis Canada produced clinical practice guidelines on the management of OP patients at risk for fractures (Papaioannou et al. CMAJ 2010). We describe the real-world incidence of primary and subsequent fragility fractures in elderly Canadians in Ontario, Canada in a timespan (2011–2017) following guideline introduction. This retrospective observational study used de-identified health services administrative data generated from the publicly funded healthcare system in Ontario, Canada from the Institute for Clinical Evaluative Sciences. The study population included individuals ≥66 years of age who were hospitalized with a primary (i.e. index) fragility fracture (identified using ICD-10 codes from hospital admissions, emergency and ambulatory care) occurring between January 1, 2011 and March 31, 2015. All relevant anatomical sites for fragility fractures were examined, including (but not limited to): hip, vertebral, humerus, wrist, radius and ulna, pelvis, and femur. OP treatment in the year prior to fracture and subsequent fracture information were collected until March 31, 2017. Patients with previous fragility fractures over five years prior to the index fracture, and those fractures associated with trauma codes, were excluded. 115,776 patients with an index fracture were included in the analysis. Mean (standard deviation) age at index fracture was 80.4 (8.3) years. In the year prior to index fracture, 32,772 (28.3%) patients received OP treatment. The incidence of index fractures per 1,000 persons (95% confidence interval) from 2011–2015 ranged from 15.16 (14.98–15.35) to 16.32 (16.14–16.51). Of all examined index fracture types, hip fractures occurred in the greatest proportion (27.3%) of patients (Table). The proportion of patients incurring a second fracture of any type ranged from 13.4% (tibia, fibula, knee, or foot index fracture) to 23% (vertebral index fracture). Hip fractures were the most common subsequent fracture type and the proportion of subsequent hip fractures was highest in patients with an index hip fracture (Table). The median (interquartile range [IQR]) time to second fracture ranged from 436 (69–939) days (radius and ulna index fracture) to 640 (297–1,023) days (tibia, fibula, knee, or foot index fracture). The median (IQR) time from second to third fracture ranged from 237 (75–535) days (pelvis index fracture) to 384 (113–608) days (femur index fracture). This real-world study found that elderly patients in Ontario, Canada incurring a primary fragility fracture from 2011–2015 were at risk for future fractures occurring over shorter periods of time with each subsequent fracture. These observations are consistent with previous reports of imminent fracture risk and the fragility fracture cascade in OP patients (Balasubramanian et al. ASBMR 2016, Toth et al. WCO-IOF-ESCEO 2018). Overall, these data suggest that in elderly patients with an index fragility fracture at any site (with the exception of the radius or ulna), the most likely subsequent fracture will occur at the hip in less than 2 years

Aims. Dead-space management, following dead bone resection, is an important element of successful chronic osteomyelitis treatment. This study compared two different biodegradable antibiotic carriers used for dead-space management, and reviewed clinical and radiological outcomes. All cases underwent single-stage surgery and had a minimum one-year follow-up. Methods. A total of 179 patients received preformed calcium sulphate pellets containing 4% tobramycin (Group OT), and 180 patients had an injectable calcium sulphate/nanocrystalline hydroxyapatite ceramic containing gentamicin (Group CG). Outcome measures were infection recurrence, wound leakage, and subsequent fracture involving the treated segment. Bone-void filling was assessed radiologically at a minimum of six months post-surgery. Results. The median follow-up was 4.6 years (interquartile range (IQR) 3.2 to 5.4; range 1.3 to 10.5) in Group OT compared to 4.9 years (IQR 2.1 to 6.0; range 1.0 to 8.3) in Group CG. The groups had similar defect sizes following excision (both mean 10.9 cm. 3. (1 to 30)). Infection recurrence was higher in Group OT (20/179 (11.2%) vs 8/180 (4.4%), p = 0.019) than Group CG, as was early wound leakage (33/179 (18.4%) vs 18/180 (10.0%), p = 0.024) and subsequent fracture (11/179 (6.1%) vs 1.7% (3/180), p = 0.032). Group OT cases had an odds ratio 2.9-times higher of developing any one of these complications, compared to Group CG (95% confidence interval 1.74 to 4.81, p < 0.001). The mean bone-void healing in Group CG was better than in Group OT, in those with ≥ six-month radiological follow-up (73.9% vs 40.0%, p < 0.001). Conclusion. Local antibiotic carrier choice affects outcome in chronic osteomyelitis surgery. A biphasic injectable carrier with a slower dissolution time was associated with better radiological and clinical outcomes compared to a preformed calcium sulphate pellet carrier. Cite this article: Bone Joint Res 2023;12(7):412–422

The August 2024 Shoulder & Elbow Roundup. 360. looks at: Comparing augmented and nonaugmented locking-plate fixation for proximal humeral fractures in the elderly; Elevated five-year mortality following shoulder arthroplasty for fracture; Total intravenous anaesthesia with propofol reduces discharge times compared with inhaled general anaesthesia in shoulder arthroscopy: a randomized controlled trial; The influence of obesity on outcomes following arthroscopic rotator cuff repair; Humeral component version has no effect on outcomes following reverse total shoulder arthroplasty: a prospective, double-blinded, randomized controlled trial; What is a meaningful improvement after total shoulder arthroplasty by implant type, preoperative diagnosis, and sex?; The safety of corticosteroid injection prior to shoulder arthroplasty: a systematic review; Mortality and subsequent fractures of patients with olecranon fractures compared to other upper limb osteoporotic fractures

Fracture of contemporary femoral stems is a rare occurrence. Earlier THR stems failed due to design issues or post manufacturing heat treatments that weakened the core metal. Our group identified and analyzed 4 contemporary fractured femoral stems after revision surgery in which electrochemical welds contributed to the failure. All four stems were proximally porous coated titanium alloy components. All failures occurred in the neck region post revision surgery in an acetabular cup exchange. All were men and obese. The fractures occurred at an average of 3.6 years post THR redo (range, 1.0–6.5 years) and 8.3 years post index surgery (range, 5.5–12.0 years). To demonstrate the effect of electrocautery on retained femoral stems following revision surgery, we applied intermittent electrosurgical currents at three intensities (30, 60, 90 watts) to the polished neck surface of a titanium alloy stem under dry conditions. At all power settings, visible discoloration and damage to the polished neck surface was observed. The localized patterns and altered metal surface features exhibited were like the electrosurgically-induced damage priorly reported. The neck regions of all components studied displayed extensive mechanical and/or electrocautery damage in the area of fracture initiation. The use of mechanical instruments and electrocautery was documented to remove tissues in all 4 cases. The combination of mechanical and electrocautery damage to the femoral neck and stem served as an initiation point and stress riser for subsequent fractures. The electrocautery and mechanical damage across the fracture site observed occurred iatrogenically during revision surgery. The notch effect, particularly in titanium alloys, due to mechanical and/or electrocautery damage, further reduced the fatigue strength at the fractured femoral necks. While electrocautery and mechanical dissection is often required during revision THA, these failures highlight the need for caution during this step of the procedure in cases where the femoral stem is retained

One of the most important sequelae to ageing is osteoporosis and subsequently hip fractures. Hip fractures are associated with major morbidity, mortality and costs. Most patients require surgery to restore mobility. Provision of surgery and its complications is poorly understood in South Africa. Our aim was to collect and report current hip fracture care at four centres in South Africa, as well as reporting surgical and general patient outcomes. A three year retrospective cohort at four centres will be described, focussing on provision of surgical care, mortality, types of surgery and complications. We identified 562 patients who had surgical intervention for fragility fractures, 66% were females. Forty nine percent had open reduction and internal fixation, 28% had hemi-arthroplasty replacement whilst 23% had total hip replacements. Twenty percent of patients had operative intervention within 36 hours of presentation to the emergency department. Mortality was 9% at 30 days. The most common complications were lower respiratory infections (29%), urinary tract infections (21%) and surgical site infections (9%). This is the largest cohort of surgically treated hip fracture from South Africa. Proportions of patients receiving different surgical interventions such as THR are comparable to the broader literature. However a number of key performance indicators such as surgery within 36 hours are challenging to meet. Given the changing demographics of South Africa, this study provides an early insight to contemporary care and may help provide direction for broader national strategies for reporting and improving hip fracture care

Aims. Dead space management is an important element in the surgical management of chronic osteomyelitis and can be addressed with the use of a biodegradable local antibiotic carrier. We present the clinical and radiographic outcomes in two different biodegradable antibiotic carriers used in the management of chronic osteomyelitis. Method. A single centre series reviewed between 2006–2017. The initial cohort (2006–2010) of 180 cases (Group A) had a calcium sulphate carrier containing tobramycin (Osteoset. ®. T, Wright Medical). The second cohort (2013–1017) of 162 cases (Group B) had a biphasic calcium sulphate, nano-crystalline hydroxyapatite carrier containing gentamicin (Cerament. TM. G, Bonesupport AB). All cases were Cierny-Mader Grade III and IV and had a minimum of one-year clinical follow-up. Clinical outcomes reviewed included infection recurrence rate, wound leak, and subsequent fracture involving the treated segment. All cases with a minimum one-year radiographic follow-up were reviewed and bone void filling was assessed as percentage filling on the final follow-up radiograph to the nearest five percent increment. Results. Mean follow-up in Group A was 4.2 years (range 1.3–10.5 years) and in Group B it was 1.8 years (1–4.7 years). Group A had a significantly higher rate of infection recurrence (19/180 (10.6%) Vs. 7/163 (4.4%) p=0.030), wound leak (33/180 (18.3.%) Vs. 16/162 (9.9%) p=0.026) and subsequent fracture rate (11/180 (6.1%) Vs. 3/162 (1.9%) p=0.047) compared to Group B. Of the cases with a minimum of one-year radiographic follow-up Group A had 96 cases (mean follow-up 3.3 years, range 1.0–10.5 years) and Group B had 137 cases (mean follow-up 1.6 years, range 1.0–4.7 years). The mean bone void healing in Group B was significantly better than Group A (74.0% Vs. 41.7%, p <0.00001). Conclusions. Cerament. TM. G has significantly better bone healing compared to a calcium sulphate carrier and was associated with a lower rate of recurrent infection, wound leak and subsequent fracture risk

Aims. The use of local antibiotic carriers in the treatment of chronic osteomyelitis is an important adjunct in dead space management. We present the outcomes of two different biodegradable antibiotic carriers used in the management of chronic osteomyelitis. Method. A single centre series between 2006–2017. The initial cohort (2006–2010) of 137 cases, Group A, had Osteoset® T (calcium sulphate carrier containing tobramycin). The second cohort (2013–1017) of 160 cases, group B, had CeramentTM G (biphasic calcium sulphate, nano-crystalline hydroxyapatite carrier containing gentamicin). Only Cierny-Mader Grade III and IV cases were included with a minimum six-month radiographic follow-up. Infection recurrence rate, wound leakage, subsequent fracture involving the treated segment, and radiographic void filling were assessed at a minimum of 6 months following surgery. Results. Mean follow-up in Group A was 2.5 yrs (0.5–10.5) and in Group B it was 1.4 yrs (0.6–4.7). Group A had a significantly higher rate of infection recurrence (16/137 (11.7%) Vs. 7/160 (4.4%) p=0.0278), wound leakage (26/137 (19.0%) Vs. 16/160 (10.0%) p=0.0304) and subsequent fracture rate (11/137 (8.0%) Vs. 3/160 (1.9%) p=0.0143) compared to Group B. Average time to recurrence was 1.07 years (0.1–2.6) in Group A and 1.02 (0.2–2.1) in Group B. The mean bone void healing in Group B was significantly better than Group A (73.2% Vs. 40.0%, p <0.00001). Conclusions. Cerament™ G has significantly better bone healing compared to a calcium sulphate carrier and was associated with a lower rate of recurrent infection, wound leakage and subsequent fracture risk

Treat to target is the use of a physiologic marker as a monitor of effectiveness or compliance to an intervention. A recent example has been the progressive use of CTX-1 (Marker of osteoclastic activity) as a surrogate of bone resorptive activity in osteoporosis treatment. CTX-1 levels were demonstrated to be inversely related to drug efficacy in the suppression of bone resorption. As far as fragility fractures are concerned, no reference value of CTX-1 for any index fracture sites was found in the literature. In order to prevent subsequent fractures, efforts to better manage this chronic disease are to be explored. The main objective of this study was to compare and validate the use of serum CTX-1 to the perceived compliance to treatment. Five hundred and forty three patients (men and women) 40 years of age or older who had been treated for a fragility fracture were enrolled. The purpose of this study was to correlate the measurement of CTX-1 with the perceived compliance to treatment of patients at the time of fracture and at six, 12 and 18 months after initiation of treatment. Our secondary objectives were to evaluate two different CTX-1 suppression target levels (CTX-1< 0.3 ng/mL and CTX-1<0.2 ng/mL), to determine CTX-1 values according to fracture sites, and to explore the profile of patients with subsequent fractures. Considering index fractures, compliant patients under treatment at baseline had lower CTX-1 levels than non-compliant patients (p=0.052). Patients who were compliant to treatment at six, 12 and 18 months also had lower CTX-1 levels than non-compliant patients (p=0.000). When index fractures were divided into fracture sites, regardless of CTX-1 suppression target level (i.e. CTX-1< 0.3 or 0.2 ng/mL), significant CTX-1 suppression was observed in non-hip and non-vertebral (NHNV) fractures at six, 12 and 18 months (p0.05). No clinically relevant difference was observed between the profile of patients with and without subsequent fractures. The correlation between serum CTX-1 at the time of fracture and at six, 12, 18 months and the perceived compliance to treatment was validated for NHNV fractures supporting the concept of the available treatments and their effects on bone remodeling for this type of fracture. The correlation was not validated for hip neither for vertebral fracture. There was no correlation between CTX-1 levels and subsequent fracture risk

Aims. The management of completely displaced fractures of the distal radius in children remains controversial. This study evaluates the outcomes of surgical and non-surgical management of ‘off-ended’ fractures in children with at least two years of potential growth remaining. Methods. A total of 34 boys and 22 girls aged 0 to ten years with a closed, completely displaced metaphyseal distal radial fracture presented between 1 November 2015 and 1 January 2020. After 2018, children aged ten or under were offered treatment in a straight plaster or manipulation under anaesthesia with Kirschner (K-)wire stabilization. Case notes and radiographs were reviewed to evaluate outcomes. In all, 16 underwent treatment in a straight cast and 40 had manipulation under anaesthesia, including 37 stabilized with K-wires. Results. Of the children treated in a straight cast, all were discharged with good range of mo (ROM). Five children were discharged at six to 12 weeks with no functional limitations at six-month follow-up. A total of 11 children were discharged between 12 and 50 weeks with a normal ROM and radiological evidence of remodelling. One child had a subsequent diaphyseal fracture proximal to the original injury four years after the initial fracture. Re-displacement with angulation greater than 10° occurred for 17 children who had manipulation under anaesthesia. Four had a visible cosmetic deformity at discharge and nine had restriction of movement, with four requiring physiotherapy. One child developed over- granulation at the pin site and one wire became buried, resulting in a difficult retrieval in clinic. No children had pin site infections. Conclusion. Nonoperative management of completely displaced distal radial fractures in appropriately selected cases results in excellent outcomes without exposing the child to the risks of surgery. This study suggests that nonoperative management of these injuries is a viable and potentially underused strategy. Cite this article: Bone Joint J 2021;103-B(5):902–907

Introduction: Among numerous international studies on hip fractures only few were dealing with the occurrence and risk of a subsequent hip fracture. Some studies contain information identifying patients at risk of subsequent hip fractures as well as the risk of a hip fracture following another osteoporotic fracture, others on outcome following the subsequent fracture. Material and methods: The Funen County Hip Fracture Register contains information on every consecutive hip fracture in the county of Funen since January 1st 996. The register contains general information about the patient i.e.: type of fracture, operative treatment, complications, living conditions, ADL, as well as information from 4 and 12 month out-patient visit and if necessary re-surgery. A maximum of 155 variables can be recorded about every patient. The register has been subjected to a complete revision and validation (4.660 patient files was checked) and contained a total number of 7.457 hip fractures from January 1st 1996 to December 31st 2003. Incidence numbers were calculated based on risk of fracture from the first fracture since January 1st 1996 to death or December 31st 2003. Results: In the period January 1st 1996 to December 31st 2003, 7,457 fractures were registered. Of these, 261 patients were registered with a second fracture, the primary fracture occurring before the period and thus excluded. Within the period 6,676 primary fractures were registered, and of these 520 patients (7.5 %) experienced a subsequent fracture. The median time from primary to subsequent fracture was 8 months (range 0–75 months) in males and 14 months (range 0–82 months) in females, the overall median was 13.5 months (range 0–82 months). In males the risk of dying after the primary hip fracture was 10 times higher than the risk of sustaining a subsequent hip fracture, in females it was five times higher. Conclusion: Only few patients with a hip fracture will experience a subsequent hip fracture and with the short time frame presented, any intervention should have immediate impact

Aims

This study aimed to determine whether lateral femoral wall thickness (LWT) < 20.5 mm was associated with increased revision risk of intertrochanteric fracture (ITF) of the hip following sliding hip screw (SHS) fixation when the medial calcar was intact. Additionally, the study assessed the association between LWT and patient mortality.

Aims

Excision of chronic osteomyelitic bone creates a dead space which must be managed to avoid early recurrence of infection. Systemic antibiotics cannot penetrate this space in high concentrations, so local treatment has become an attractive adjunct to surgery. The aim of this study was to present the mid- to long-term results of local treatment with gentamicin in a bioabsorbable ceramic carrier.

Aims

We aimed to develop a gene signature that predicts the occurrence of postmenopausal osteoporosis (PMOP) by studying its genetic mechanism.

Purpose. There are concerns with regard to the physiological effects of reamed intramedullary femoral fracture stabilisation in patients who have received a pulmonary injury. This large animal study used invasive monitoring techniques to obtain sensitive cardiopulmonary measurements and compared the responses to Early Total Care (reamed intramedullary femoral fracture fixation) to Damage Control Orthopaedics (external fixation), after the induction of acute lung injury. We hypothesised a greater cardiopulmonary response to intramedullary fracture fixation. Method. Acute lung injury (PaO2/FiO2 < 200 mmHg) was induced in 12 invasively monitored and terminally anaesthetised male sheep via the infusion of oleic acid into the right atrium. Each animal underwent surgical femoral osteotomy and fixation with either reamed intramedullary (n=6) or external fixation (n=6). Simultaneous haemodynamic and arterial blood-gas measurements were recorded at baseline and at 5, 30 and 60 minutes after fracture stabilisation. Results. The mean (S.E.) PaO2/FiO2 fell significantly (p<0.05) from 359(37) to 107 (23) and 382 (33) to 128 (18) in the externally fixated and intramedullary nailed groups respectively as a result of the acute lung injury. The further combined effect of surgical osteotomy and subsequent fracture fixation produced a mean (+/− S.E.) PaO2/FiO2 of 114 (21) and 113 (12), in the externally fixated and intramedullary nailed groups respectively, immediately after surgery. This was not significantly different either within or between groups. Similarly the pulmonary vascular resistance (PVR) measured at 4.7 (0.9) and 4.2 (0.5) in the externally fixated and intramedullary nailed groups respectively after lung injury changed to 4.9 (0.7) and 4.3 (0.6) after surgical osteotomy and subsequent fracture fixation which, again was not significantly different either within or between groups. No significant difference in either PaO2/FiO2 or PVR was detected at the monitored 5, 30 and 60 minute intervals that followed fracture stabilisation. Conclusion. Against a background of standardised acute lung injury, there appeared to be no further deterioration produced by the method of isolated femoral fracture fixation in two sensitive physiological parameters commonly used by intensive care physicians

Objective: To assess whether hemicortical excision and biological reconstruction instead of the conventional wide resection for selected cases of malignant surface tumors, may give adequate oncologic clearance with less morbidity and better function. Methods: From January 2000 to June 2007 a total of 29 malignant surface tumors were managed at our institute. Fifteen of these were treated with hemicortical excision and reconstruction. They consisted of 10 parosteal osteosarcomas, 1 periosteal osteosarcoma, 1 high grade surface osteosarcoma, 1 adamantinoma and 2 surface chondrosarcomas. Nine were in the distal femur, 3 in tibia, 2 in the humerus and 1 in the radius. Four of these were residual/recurrent lesions following earlier intervention. After hemicortical excision with adequate margins the bone defect was reconstructed with allograft/autograft and suitable internal fixation where indicated. Results: Margins were reported free in all cases. There were no infections. Three of five patients who did not have fixation with a plate at index surgery sustained a subsequent fracture which was then reduced and fixed. Follow up duration was from 24 to 90 months. Two patients had isolated soft tissue recurrences. Both underwent re excision and are currently disease free at 36 and 38 months respectively after recurrence. Eleven patients had a maximum possible score of 30 (MSTS functional scoring); other four had a score of 29. None of the cases have developed distant metastasis. Discussion: Early results indicate that in selected cases, hemicortical excision is an oncologically sound procedure. The ability to do a biological reconstruction with bone helps avoid some of the serious complications of a megaprosthetic reconstruction while permitting full active loading of the extremity and near normal function. Internal fixation at index surgery permits early mobilization and minimises the incidence of subsequent fractures

Introduction Starting in 1994 a series of four studies of Osteolymphoma (Primary Bone Lymphoma) have been undertaken. These studies were intended to characterise the disease and provide reliable information about treatment outcomes. Methods Following a pilot study of 17 patients at West-mead hospital, an Australia-wide survey was conducted through the Australasian Radiation Oncology Lymphoma Group (AROLG) and data were published relating to 70 cases from nine institutions. Thereafter a prospective clinical trial was started under the auspices of the Trans-Tasman Radiation Oncology Group (TROG) and is currently accruing satisfactorily. To foster accrual to this trial the International Extranodal Study Group (IELSG) was invited to participate and they indicated they would only do so after a retrospective study of their own databases was undertaken. This retrospective study is also underway. Results Results so far indicate a highly heterogeneous disease but with some common features, including some previously unnoticed behaviours, particularly the tendency to occur and recur mulitfocally both monostotically and polyostotically. The results are worse than other lymphomas but the use of new combinations of chemotherapy and radiotherapy is being tested and is likely to improve upon the outcomes. After eradicating the disease, there is a significant risk of subsequent fracture related to treatment factors. Orthopaedic surgery still has an important role to play in obtaining sufficient biopsy material without compromising stability, in providing stability where needed prior to radiotherapy and chemotherapy and in the treatment of subsequent fractures. Conclusions Specialists involved in the treatment of bone tumours are encouraged to become familiar with this world-wide, Australian based line of investigation so that maximum accrual can be achieved. In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source

Aim: Alcohol-abuse is a well-recognised problem in the West of Scotland. This retrospective case-note study aims to assess the presentation, management and early outcome of alcohol-abusing patients sustaining displaced intracapsular fractures compared to age-matched controls. Methods: Patients were identified from a prospectively-collected database of trauma admissions from 1998 to 2002. Alcohol-abuse was defined by documented evidence of excessive and chronic alcohol intake. Results: 35 alcohol-abusing patients under the age of 65 (mean age 57.5 years) with displaced intracapsular fractures were identified and followed-up for a mean of 3.87 years, and compared with 39 age-matched controls (mean follow-up 3.35 years). There was a significant difference between groups in interval between injury and surgery, with alcohol-abusers undergoing surgery 40.2 hours after injury compared to 22.2 hours for controls (p=0.039). Post-operative stay was also significantly different, with discharge at 7.0 and 5.0 days post-operatively for abusers and controls respectively (p=0.002). 26% of abusers required increased level of care after discharge compared with 15% of non-abusers, although this did not reach statistical significance. Reduction and fixation was employed in 26 alcohol-abusing patients and 30 controls. Early postoperative complications were similar in both groups with the exception of delirium tremens (17% of abusers). Of patients treated with internal fixation, four patients in the alcohol-abuse group required revision surgery (15%) compared to three of the control group (10%, no significant difference). Two patients within the abusers group developed avascular necrosis (7.7%) compared to three within the control population (10%, no significant difference); only two of these five required revision surgery with femoral head replacement. During the follow-up period, alcohol-abusers had a five-fold higher rate of subsequent fractures of their contralateral hip or elsewhere (p=0.02). Conclusions: Alcohol-abusing patients with displaced intracapsular fractures have an increased economic burden compared to controls requiring longer inpatient stays and more frequent subsequent fractures. However, despite increased intervals between injury and surgery, this study finds no evidence that they are at greater risk of failure of internal fixation as compared to controls

Residual kyphotic deformity is considered the main factor for the increased risk of new fractures after an osteoporotic vertebral fracture. We hypothesized that even in the absence of kyphotic deformity, the altered pressure profile of the disc after a fracture will increase the risk for subsequent fractures. Materials and Methods: Six fresh-frozen, human thoracolumbar specimens, consisting of 5 adjacent vertebrae, were used. A void was randomly created under the upper (n=3) or the lower (n=3) endplate of the middle vertebra. The specimen was then compressed in flexion until a selective fracture of the weakened endplate was observed. Vertebral kyphosis was reduced with extension. After cementation of the fracture, the rest of the trabecular content was evacuated and was filled with cement. Specimens were tested in flexion-extension (±6Nm) under 400N preload before and after the index fracture. Pressure was recorded at the discs above and below the fractured VB and strain at the anterior wall of the adjacent VBs. Finally, the specimen was loaded in flexion until a subsequent fracture was observed on fluoroscopy. Results: In the intact specimens, nucleus pressure increased by 26.4±13.9% in full flexion compared to neutral posture. After the index fracture, the pressure in full flexion increased by 15.2±11 % in the discs with unfractured endplates, but decreased by 19±26.7% in the discs with the fractured endplate (p< 0.05). Anterior wall strain at the VB adjacent to the fractured endplate increased by 94.2%±22.8% (p=0.02), compared to an 18.2%±7.1% (p=0.98) increase at the VB adjacent to the unfractured endplate. Subsequent loading of the specimens after cementation of the index fracture resulted in a fracture of the adjacent VB close to the fractured endplate of the middle vertebra in 4 specimens and at the upper potted VB in one specimen. Maximum load applied with the actuators failed to create a fracture in one specimen. Discussion: The effects of the fractured endplate were isolated by eliminating other known parameters. Vertebral kyphosis was reduced and cement was similarly distributed under both endplates. In the intact specimens, nucleus pressure gradually increased during flexion. This can more evenly distribute the load during flexion to the entire surface of the endplate and avoid excessive load concentration to the anterior portion. After an endplate fracture, the nucleus pressure gradually decreased during flexion, meaning that the anterior annulus was forced to bear more load. This uneven load transfer to the anterior part of the VB resulted in doubling the strain at the VB adjacent to the fractured end plate. All adjacent factures were observed at the vertebra next to the damaged endplate. The altered mechanical behavior of the nucleus can be ascribed to the increased available space after the endplate depression

Purpose. The prevention of a subsequent, contralateral hip fracture is targeted as an avoidable event in the elderly. Fall prevention and bone strengthening measures have met with limited success and the urgency of their effect is undetermined. Our objective was to evaluate the time to second hip fracture (the time between a first and a subsequent, contralateral fracture) in elderly patients, using a population-based administrative health data set. Method. The 58,286 records of persons older than 60 yrs and hospitalized for a hip fracture between 1985 and 2005 were obtained from a Provincial administrative health database. We excluded non-traumatic cases and identified the care episodes related to a subsequent hip fracture for each patient using unique identifiers. We used a 5 year “wash-out period” to avoid counting a second fracture as a first one. We calculated the proportion of first and second fractures and sex distribution over time (fiscal years) and quantified the time between first and second fracture, while correlating it to age, sex and fracture type. Results. Overall, 3,866 patients sustained a second hip fracture between 1990 and 2005; 3,119 (81%) were women, in contrast to 73% for primary fractures (chi-square =137.8, df=1, p<0.001). In 33% cases, the type of a subsequent fracture (transcervical vs pertrochanteric) was different from the first. The median time from first fracture was 3 years, 90% occurred by 9yrs. The age at the first fracture most influenced the time to second fracture. The median time (90th percentile in parentheses) between fractures decreased as patients got older and was 5 (13), 4 (10), 3 (7), 2 (5) years for patients who were correspondingly 60–69, 70–79, 80–89 and 90+ years old at first fracture. Conclusion. Among survivors of an initial hip fracture, the occurrence of a second hip fracture appears to affect a greater proportion of women than primary fractures. Our results identify the time frame which preventative interventions should target when aiming at reducing second hip fractures, that target being increasingly small (from 5 to 2 years) as patients age. This information identifies a time frame researchers must target as they seek new fracture prevention methods. In the shorter term however, these data could influence health administrators and policy makers as they decide to support one hip fracture prevention method over another