BACKGROUND: Osteopetrosis is a rare hereditary disease that can be transmitted in an autosomal recessive or autosomal dominant.
METHODS: Here, we report a case of trochanteric fracture in an 18-year-old boy with an anatomical plate. At the last follow-up, 24 months after surgery, the fracture had healed well, and the patient was not restricted in his activities.
CONCLUSIONS: Osteopetrosis is a rare bone disease that is mainly caused by osteoclast dysfunction. It results from a remodelling defect that leads to hypermineralization of the skeleton, resulting in bone fragility. Both surgical and nonsurgical management have advantages and disadvantages. Thus, open reduction and anatomic plate fixation remain effective management modalities for trochanteric fractures in osteopetrosis patients.
CONCLUSIONS: For our patient and as described in the literature, the complication rate decreases as some principles are respected with better consolidation of the osteoporotic fracture.

Bisphosphonates have been accepted as the first-line treatment for postmenopausal osteoporosis. Atypical femoral shaft fracture is one of the side effects of long-term bisphosphonate therapy. The mainstay treatment of this atypical fracture is bisphosphonates cessation and stabilization with internal fixation. We are reporting a rare case of a blocked intramedullary femoral canal found during surgery of an 85-year-old Indian lady with an atypical femoral shaft fracture related to her five-year alendronate therapy. We found difficulty in passing the guidewire through the fracture site during the closed method, which renders open reduction to manage the obliterated intramedullary canal. The importance of changing decisions intraoperatively should be highlighted to avoid further complications. Fracture union is achieved during our follow-up in the clinic.

Giant cell tumor of the bone (GCTB) is a locally aggressive neoplasm where surgery is often curative. However, it can rarely give rise to distant metastases. Currently, the only available active therapeutic option for unresectable GCTB is denosumab, an anti-RANKL monoclonal antibody that dampens the aggressive osteolysis typically seen in this disease. For advanced/metastatic GCTB, denosumab should be continued lifelong, and although it is usually well tolerated, important questions may arise about the long-term safety of this drug. In fact, uncommon but severe toxicities can occur and eventually lead to denosumab discontinuation, such as atypical fracture of the femur (AFF). The optimal management of treatment-related AFF is a matter of debate, and to date, it is unknown whether reintroduction of denosumab at disease progression is a clinically feasible option, as no reports have been provided so far. Hereinafter, we present a case of a patient with metastatic GCTB who suffered from AFF after several years of denosumab; we describe the clinical features, orthopedic treatment, and oncological outcomes, finally providing the first evidence that denosumab rechallenge after AFF occurrence may be a safe and viable option at GCTB progression.

As patient longevity continues to improve, the rate of lower limb revision arthroplasties will continue to increase as patients outlive the expiration of their implants. With continued bone loss and reduced stability, there is a limit to the number of revision operations that can be performed. Total femoral arthroplasty (TFA) is an increasingly popular limb-salvaging alternative that can restore some degree of daily function to patients. This report presents a 73-year-old male with multiple right lower-limb operations following two extreme motorcycle accidents in the last 22 years. Due to continued pain and poor femoral bone stock following multiple total knee arthroplasty (TKA) revisions, a TFA was performed. The procedure was successful and post-operative expectations were met despite setbacks in immediate rehabilitation. Overall, TFA is an effective alternative to lower limb amputation in the setting of aseptic, non-oncologic bone loss following multiple knee revisions. However, careful management is necessary to reduce the risk of infection and other complications.

Atypical femur fractures (AFFs) are well-established serious complication of long-term bisphosphonate and denosumab therapy in patients with osteopenia or osteoporosis. To elucidate underlying mechanism(s) for the development of AFF, we performed a nested case-control study to investigate bone tissue nanomechanical properties and prevailing bone microstructure and tissue-level remodeling status as assessed by bone histomorphometry. We hypothesized that there would be differences in nanomechanical properties between patients with and without AFF and that bone microstructure and remodeling would be related to nanomechanical properties. Thirty-two full-thickness transiliac bone biopsies were obtained from age- and sex-matched patients on long-term bisphosphonate therapy with (n = 16) and without an AFF (n = 16). Standard histomorphometric measurements were made in each sample on three different bone envelopes (cancellous, intracortical, and endosteal). Iliac bone wall thickness was significantly lower on all three bone surfaces in patients with AFF than in those without AFF. Surface-based bone formation rate was suppressed similarly in both groups in comparison to healthy premenopausal and postmenopausal women, with no significant difference between the two groups. Nanoindentation was used to assess material properties of cortical and cancellous bone separately. Elastic modulus was higher in cortical than in cancellous bone in patients with AFF as well as compared to the elastic modulus of cortical bone from non-AFF patients. However, the elastic modulus of the cancellous bone was not different between AFF and non-AFF groups or between cortical and cancellous bone of non-AFF patients. Resistance to plastic deformation was decreased in cortical bone in both AFF and non-AFF groups compared to cancellous bone, but to a greater extent in AFF patients. We conclude that long-term bisphosphonate therapy is associated with prolonged suppression of bone turnover resulting in altered cortical remodeling and tissue nanomechanical properties leading to AFF. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

UNASSIGNED: Paget\'s disease (PD) is the most common metabolic bone disorder after osteoporosis. Clinically, it can result in pain, bony deformity, pathologic fractures, and, in the late stage, progression to malignancy. At a pathophysiological level, PD manifests as an imbalance between the homeostasis of bone destruction and formation. Bones most often involved with this disease process include the pelvis, femur, tibia, vertebra, and skull. The goals of orthopedic intervention in PD are two-fold: Prevention of pathologic fracture with internal stabilization and reconstruction following fracture, which is often complicated by poor bone quality and advanced deformity. In this case report, authors detail a patient with PD who presented with a pathologic left subtrochanteric femur fracture requiring a novel complex femoral reconstruction with a 29-year follow-up period. To the best of our knowledge, no such report exists, particularly with this degree of long-term follow-up.
UNASSIGNED: A 70-year-old Caucasian man with PD presented with an atypical subtrochanteric femur fracture after a ground level fall. Due to his significant femoral deformity and osteopenia, proximal femoral resection followed by composite femoral allograft reconstruction with total hip arthroplasty was performed. Long-term durability of this novel reconstruction method as well as longitudinal clinical and radiographic outcomes is described.
UNASSIGNED: Complex pathologic fractures in patients with PD can be effectively treated with composite femoral allograft reconstruction and total hip arthroplasty with good long-term radiographic and clinical outcomes. Broadly, it is important to note the unique healing pattern seen in PD bone and to consider the implications it may have when planning surgical intervention.

UNASSIGNED: Atypical fracture patterns, especially to the femur midshaft, have begun emerging since long-term bisphosphonate use was introduced. The same fracture pattern could arise around prosthetic hip implant, but the literature reports few cases regarding atypical periprosthetic femur fracture on previous total hip arthroplasty implant in patients on long-term bisphosphonate therapy. To our knowledge we report here the first case of atypical periprosthetic femur fracture arising after total hip arthroplasty implant on a previously identified but underestimated atypical femur pattern.
UNASSIGNED: Surgeons should never underestimate an atypical femur pattern on x-rays and always relate groin and thigh pain to hip pathology before performing total hip arthroplasty.

Osteoporosis leads to reduced bone mass and disrupted bone architecture. Bisphosphonates are used to treat osteoporosis by inhibiting bone resorption. Chronic bisphosphonate use has been associated with adverse effects including atypical femoral fractures (AFF). We report the case of a 63-year-old woman with a history of osteoporosis treated with alendronate, who presented with bilateral hip and groin pain. Radiography detected a chronic-appearing callus in the left hip concerning for a chronic stress fracture versus malignancy. Initial imaging could not rule out malignancy, prompting positron emission tomography (PET) and bone biopsy. PET scan was negative for malignancy and biopsy found changes consistent with chronic bisphosphonate use. This prompted prophylactic intramedullary nailing of the femur. This case highlights the importance of considering AFF in patients with a history of hip pain in the setting of chronic BPs use and reviews criteria within the literature to manage patients with AFFs.

Atypical femur fractures as a result of long term bisphosphonate use are characterized by several unique radiographic features. We describe an atypical femur fracture treated by cephalomedullary nail with a previously undescribed segmental fracture pattern. Other than 1.5 years of bisphosphonate use the patient did not have any other risk factors known to cause atypical femur fractures. Judicious bisphosphonate use as well as increased awareness of the associated complications may help reduce the rate of bisphosphonate associated atypical femur fractures.