There has been evidence of association between femoral shaft fractures and prolonged bisphosphonate therapy. We present a case series of bisphosphonate-associated fractures and invaluable lessons we have learnt. Over the last three years at our unit we have collected a case series of eight patients who have had atypical femoral fractures whilst on bisphosphonate therapy. We present illustrative cases, a summary of key findings, and invaluable lessons we have learnt. There was a long period of prodromal pain for two years before incomplete fractures developed. We speculate this is a warning sign of impending fracture. This may have been prevented with screening. Between incomplete fracture and complete fracture there was a short window of one month. Five patients presented with complete fracture, and three with thigh pain +/- evidence of incomplete fracture. Of the latter group all but one went on to develop complete fractures. The one patient who did not progress died six years after diagnosis. Of those five patients who presented with initial complete fracture, three patients recall thigh pain before fracture on further questioning. Despite being diaphyseal femoral fractures, there is a higher risk of neck of femur fractures in this patient cohort (both patients with initial interlocked nails subsequently developed neck of femur fractures soon after and were revised to cephalomedullary nails). Excluding one death from unrelated cause, only one patient has signs of complete fracture healing. All other patients are still receiving follow-up (mean 490 days). Three patients reported bilateral symptoms (pain). Two had had bilateral symptoms for one year. Both had visible incomplete fractures on further radiographic scrutiny; one underwent prophylactic cephalomedullary nailing, one was managed with active surveillance. We suggest that improved pain and radiographic changes of cortical healing may be misleading and should not be relied upon. Cephalomedullary nailing is the treatment of choice in these fractures due to higher risk of neck of femur fractures in this cohort. We suggest prompt prophylactic cephalomedullary nailing when radiographic incomplete fractures are identified due to a short window before progression to complete fracture, and the need to consider contralateral prophylactic nailing in patients describing bilateral symptoms. We speculate that thigh pain is a warning sign of impending fracture and fracture-progression can be prevented with appropriate screening

Abstract. Background. Schwannomas are slow-growing, benign tumours normally originating from the Schwann cells of the nerve sheath. Intraosseous schwannoma accounts for 0.175% of primary bone tumours and extremely rare especially outside the axial skeleton. Monoclonal gammopathy has been associated with soft tissue schwannomas but never with the intraosseous variety. Presenting problem. A 55-year-old woman with a background of monoclonal gammopathy of undetermined significance (MGUS) presented with a 2-year history of right thigh pain. CT scan showed a well defined, lytic lesion with a thin peripheral rim of sclerosis in the midshaft of the femur. MRI displayed a hyperintense, well marginated and homogenous lesion. Definitive diagnosis was made based on the classical histopathological appearance of schwannoma. Clinical management. We managed our patient with local curettage and prophylactic cephalomedullary nailing on the basis of a high mirel score. Discussion. Intraosseous schwannomas are poorly understood but most commonly reported in middle-aged women. Radiologically, their differential diagnosis includes malignant bone tumours, solitary bone cysts, aneurysmal bone cysts and giant cell tumours. As a result, they are usually diagnosed incidentally on histology. Although malignant transformation is possible in soft tissue schwannomas, all intraosseous schwannomas reported to date have been benign. This case demonstrates the importance of suspecting intraosseous schwannoma as a differential diagnosis for lytic bone lesions to avoid the overtreatment of patients. We also highlight monoclonal gammopathy of undetermined significance as a potential risk factor for a poorly understood disease and make recommendations about the appropriate management of these lesions. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Over 70,000 hip fractures occur annually in the UK. Both SIGN (111) and NICE (124) give guidance on optimal management of these patients. Both suggest cemented hemiarthroplasty should be used in those without contra-indications, as cemented implants are associated with less thigh pain, subsidence and a better functional outcome. Cardiorespiratory compromise secondary to bone cement implantation syndrome (BCIS) is however a concern in those with pre-existing cardiorespiratory disease (NYHA grade 3–4, pulmonary hypertension) or pathological fracture [3]. The aim of our study was to audit the practice of a University of Glasgow hospital with regard to cemented hemiarthroplasty. We retrospectively reviewed data on all patients treated with hemiarthroplasty for hip fracture at the Southern General Hospital between 01/01/12-02/04/12. Patient demographics, pre-operative plan, procedure performed, ASA grade and pre-morbid mobility were recorded. Results. Twenty-three hemiarthroplasties were performed. The median age was 82 (70–101). No patient aged over 90 underwent cemented hemiarthroplasty. Cemented implants (JRI, Furlong) were used in 26% (n=6) while 74% (n=17) underwent uncemented (Stryker, Austin-Moore) hemiarthroplasty. ASA grade was recorded in eight (35%). There were four ASA-2 patients (mild systemic disease not limiting activity) of which 75% underwent uncemented hemiarthroplasty. Pre-morbid mobility was recorded in eight (35%). All three independently mobile patients underwent uncemented hemiarthroplasty. Six (26%) had a documented pre-operative plan with regards to cement use. This study highlights the disparity between current recommendations and our Centres’ practice. Most notable were: poor recording of pre-operative mobility, poor documentation of a pre-operative surgical plan, the low use of cemented fixation even in fit mobile patients and the lack of ASA grade recording (stratification of risk) by our anaesthetic colleagues. We suggest a documented pre-operative discussion between the surgeon and anaesthetist to establish BCIS risk and decide on use of cemented arthroplasty taking into account age and mobility

Summary Statement. Atypical femoral fractures consist of a thin fracture line extending through the lateral cortex. The adjacent bone is undergoing resorption and mechanical abrasion and is often replaced with woven bone. The mechanical environment seems to inhibit healing. Background. The pathophysiology behind bisphosphonate-associated atypical femoral fractures remains unclear. Histological findings at the fracture site itself might provide important clues. So far only one case describing the histological appearance of the fracture has been published. Methods. Between 2008 and 2013, bone biopsies comprising the fracture site were collected from 8 patients with 4 displaced and 4 undisplaced atypical femoral fractures. Seven female patients reported continuous bisphosphonate use for an average of 9.5 years. One patient was a man, not using bisphosphonates. The bone biopsies were evaluated histologically, with Fourier transformed infrared imaging (FTIR) and micro-computed tomography. Results. The 4 undisplaced fractures engaged the whole cortical thickness and comprised a 150 to 200 µm wide, meandering fracture gap filled with amorphous necrotic material. Von Kossa staining showed occasional mineralised elements with bony structure within the amorphic material. Active resorption and remodeling was common in the close vicinity of the fracture, but seldom reached into the fracture gap. In some areas, the bone adjacent to the gap appeared to undergo fragmentation and disintegration, possibly due to abrasion. Woven bone was common adjacent to the fracture gap, and appeared to have been formed in defects caused by abrasion or where resorption cavities had reached into the fracture gap. Periosteal and endosteal callus was found in all cases. Far away from the fracture, large areas of osteonal bone with only empty osteocyte lacunae were found in some samples. In one patient, the remodeling process bridged the fracture gap at some points. The fracture was otherwise similar to the other undisplaced fractures. This patient had suffered from thigh pain since her bisphosphonate treatment was discontinued 18 months earlier, when the atypical fracture was diagnosed. Discussion. Atypical femoral fractures show signs of increased remodeling in the vicinity of the fracture gap. The narrow width of the gap and its necrotic contents suggest that micromotion leads to strains between the fracture fragments that precludes survival of ingrowing cells. Moreover, there seemed to be continuous mechanical fragmentation of the bone at the crack, and replacement of fragmented areas with woven bone. Thus, it appears that the fracture line is not static, but moves in the bone over time, like the changes in the course of a meandering river

Six pairs of human cadaver femora were divided equally into two groups one of which received a non-cemented reference implant and the other a very short non-dependent experimental implant. Thirteen strain-gauge rosettes were attached to the external surface of each specimen and, during application of combined axial and torsional loads to the femoral head, the strains in both groups were measured. After the insertion of a non-cemented femoral component, the normal pattern of a progressive proximal-to-distal increase in strains was similar to that in the intact femur and the strain was maximum near the tip of the prosthesis. On the medial and lateral aspects of the proximal femur, the strains were greatly reduced after implantation of both types of implant. The pattern and magnitude of the strains, however, were closer to those in the intact femur after insertion of the experimental stem than in the reference stem. On the anterior and posterior aspects of the femur, implantation of both types of stem led to increased principal strains E1, E2 and E3. This was most pronounced for the experimental stem. Our findings suggest that the experimental stem, which has a more anatomical proximal fit without having a distal stem and cortex contact, can provide immediate postoperative stability. Pure proximal loading by the experimental stem in the metaphysis, reduction of excessive bending stiffness of the stem by tapering and the absence of contact between the stem and the distal cortex may reduce stress shielding, bone resorption and thigh pain

Introduction. Hip resurfacing arthroplasty (HRA) with metal-on-metal bearing is currently emerging as a major evolution of hip arthroplasty. It could be an alternative to total hip arthroplasty. HRA also may allow young patients to perform high sports activities. It preserves proximal femoral bone stock and keeps the medullary canal intact. A large diameter of the femoral head provides wider range of the hip motion. Incidence of dislocation is very low. Most of HRA have been reported for young patients with stage of osteoarthritis. But, reports of HRA for osteonecrosis of the femoral head (ONFH) are rare and the outcomes are uncertain. Methods. This study was performed to introduce our indication and technique of HRA for the patients with ONFH and to assess the outcomes after a minimum 5-year follow up. After the biomechanical study, we set our own indications for HRA as follows: when the size of a lesion was less than 50% of the entire head and the rim at the head-neck junction was intact at least to a 5 mm above from the head-neck junction. From December 1998 to July 2004; 157 hips (139 patients) underwent HRA under the diagnosis of ONFH. Their mean age was 37 years. One hundred and fourteen hips were in men and 25 hips were in women. The average follow-up period was 88 months (range, 60 to 128 months). Clinical outcomes were evaluated with Harris Hip Scores, hip or thigh pain, limb length discrepancy, and range of motion. As a radiological evaluation, the preoperative size and staging of the lesion, patterns of bone remodeling, and complications such as femoral neck fracture, neck narrowing, loosening, and osteolysis were analyzed. Results. Sixty-two percent of the hips were staged as Steinberg IV or more. The size of the necrotic lesion in magnetic resonance imaging ranged from 23 to 50%. The Harris Hip Score increased from 77 points pre-operatively to 98 points at the final visit. All range of motions significantly improved after the operation. No patient complained of limb length discrepancy. Twenty-eight hips showed painless radiographic changes including impingement (22 hips), focal radiolucency (4 hips), and neck narrowing (2 hips). All patients showed no clinical symptoms. There was no detectable wear, dislocation, femoral neck fracture, or other complications. No revision or additional surgery was required in all patients. Conclusion. Even for the patients with ONFH, the overall minimum 5-year outcomes of HRA are promising and superior to other reports of conventional THA. Patient satisfaction is extremely high. A strict application of indications and meticulous surgical technique are critical for these successful results