ABSTRACT
Advances in implant technology and surgical techniques have greatly improved the results of femoral stem revision in total hip arthroplasty. The 10-year results obtained with extensively coated noncemented revision stems parallel those obtained with cemented stems revised by using contemporary techniques. Proximal femoral bone loss is an important consideration when planning and performing revision arthroplasty. Proximal femoral bone defects can be managed with either metal or bone. Insignificant defects can be reconstructed by using primary hip arthroplasty techniques. Proximal femoral replacement prostheses are best restricted to sedentary elderly patients. Cortical strut grafts can be used reliably to reconstruct noncircumferential segmental defects. Calcar allografts are associated with unacceptably high rates of resorption. Proximal femoral allografts with either noncemented or cemented long-stem prostheses have the potential advantage of biologic soft-tissue attachment and restoration of bone stock. Impaction allografting with cement is indicated for cavitary defects and may also restore bone stock.
Subject(s)
Arthroplasty, Replacement, Hip , Cementation , Femur , Humans , Osteolysis/etiology , Prosthesis Failure , Plastic Surgery Procedures , Reoperation , Treatment OutcomeABSTRACT
No studies have demonstrated a direct relationship between pregnancy and rib fracture. A case of spontaneous rib fracture in the third trimester presents the opportunity to examine factors unique to pregnancy that may predispose the patient to stress fractures of the lower ribs. A 28-year old woman in week 31 of her pregnancy presented with the chief complaint of acute onset of right upper quadrant pain. A chest radiograph demonstrated a minimally displaced fracture of the right 10th rib. During pregnancy, the enlarging uterus causes certain opposing muscular forces to act on the ribs, making them more susceptible to fracture after minimal trauma or after repeated stresses such as a chronic cough.
Subject(s)
Pregnancy Complications , Rib Fractures/pathology , Abdominal Pain/etiology , Adult , Cough/complications , Female , Humans , Pregnancy , Pregnancy Trimester, Third , Rib Fractures/etiologyABSTRACT
The osteochondrodysplasias are a heterogeneous group of disorders characterized by abnormal growth and remodeling of cartilage and bone, affecting from 2 to 4.7 per 10,000 individuals. Most osteochondrodysplasias are heritable and many have elaborate patterns of genetic transmission. Affected individuals generally require management by multidisciplinary teams of specialists. In this review, we divide the osteochondrodysplasias into groups based on their genetic relationships, including mutations in various types of collagen, fibroblast growth factor, cartilage oligomeric matrix protein, parathyroid hormone receptor, the diastrophic dysplasia sulfate transporter, enzymes such as steroid sulfatases, transcription factor SOX9, and a cysteine proteinase, cathepsin K. We describe the major osteochondrodysplasias, define their causes and clinical manifestations, and provide the orthopaedic surgeon with an understanding of the underlying molecular defects as well as the anatomical aspects of these disorders.
Subject(s)
Osteochondrodysplasias/genetics , Achondroplasia/genetics , Adolescent , Arylsulfatases/genetics , Cathepsin K , Cathepsins/genetics , Child , Collagen/genetics , Female , Genetic Linkage , Humans , Infant, Newborn , Mutation , Osteochondrodysplasias/diagnostic imaging , Osteogenesis Imperfecta/genetics , Phenotype , Prospective Studies , Radiography , Receptors, Fibroblast Growth Factor/genetics , Receptors, Parathyroid Hormone/genetics , Thanatophoric Dysplasia/genetics , Transcription Factors/genetics , X ChromosomeABSTRACT
A biomechanical cadaver study was performed to compare the strength and stability of three cannulated cancellous lag screws with a sliding hip screw for fixation of a vertically oriented fracture of the femoral neck (Pauwels Type III). Using eight matched pairs of human cadaveric femurs, vertically oriented femoral neck osteotomies were created, reduced, and randomized to one of the two fixation methods. The constructs were tested with incremental axial loading from 100 N to 1200 N and cyclical loading at 1000 N for 10,000 cycles; fracture displacements and ultimate load to failure were determined. The specimens stabilized using a sliding hip screw showed less inferior femoral head displacement, less shearing displacement at the osteotomy site, and a much greater load to failure than did those stabilized with multiple cancellous lag screws. These results support the use of a sliding hip screw for treatment of vertically oriented fractures of the femoral neck.
Subject(s)
Femoral Neck Fractures/physiopathology , Fracture Fixation, Internal , Biomechanical Phenomena , Bone Screws , Femoral Neck Fractures/surgery , Humans , In Vitro TechniquesABSTRACT
Laboratory evaluation of a self-compressing tibial nail demonstrated that significant, initial compression of a simulated fracture or nonunion can be obtained and controlled. However, when this nail was tested in cyclic loading, loss of its initial static compression occurred.
