Orthopedics
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Comparative Study Clinical Trial
Computer-assisted total knee arthroplasty after prior femoral fracture without hardware removal.
This study presents a consecutive series of patients who underwent total knee arthroplasty (TKA) after prior distal femoral fracture without hardware removal. The purpose of this study was to determine the effectiveness of computer-assisted TKA in patients with posttraumatic arthritis, specifically those with retained hardware after prior distal femoral fracture. The study group included a consecutive series of 16 patients who had developed posttraumatic knee arthritis after a distal femoral fracture with retention of hardware (group A). ⋯ Implant alignment and radiological parameters were similar in both groups. This study demonstrated that posttraumatic knee arthritis after prior distal femoral fracture can be safely managed using a computer-assisted TKA without hardware removal. Comparison between the study group and a matched group with atraumatic arthritis showed similar postoperative results and complication rates.
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Navigated total knee arthroplasty (TKA) results in better restoration of neutral mechanical axis than does the conventional technique. Nevertheless, coronal malalignment has not been eliminated. It is yet unknown whether errors in implant positioning occur more on the femoral side, more on the tibial side, or equally on both sides. ⋯ The femoral component was positioned more precisely than the tibial component. The latter influences gap management in the tibia-first technique and may thereby have a relevant effect on joint stability. Accuracy of the surgical technique and differences in the mathematical algorithm for the determination of landmarks are possible reasons for the difference in precision between the femoral and tibial component positioning.
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The purpose of this study was to determine the change of fixation strength after adjusting the height of polymethylmethacrylate (PMMA)-augmented pedicle screws. Cement-augmented cannulated pedicle screws with or without PMMA augmentation with a radial hole in the distal third of the screw thread were inserted into synthetic bone blocks used to model osteoporosis. Screws were left unchanged (in situ), screwed in 3 threads, or screwed out 3 threads. ⋯ Mean pullout strength was significantly higher in the groups with cement as compared to those without cement. However, in the cement groups, the screw-in group had the lowest mean pullout strength among 3 groups, and the mean pullout strength in the screw-out group was also significantly lower than that in the in situ group (P<.05). Adjustment of pedicle screw height after cement augmentation in a severely osteoporotic spine can significantly reduce the pullout strength of the screw.
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Case Reports
Posterior sternoclavicular dislocation presenting with upper-extremity deep vein thrombosis.
Posterior sternoclavicular dislocation is an uncommon injury and often remains initially undiagnosed due to variable clinical presentation and inadequate visualization of the joint on plain radiographs. It is frequently associated with serious and life-threatening injuries involving the trachea, esophagus, or great vessels. A 15-year-old boy was knocked to the ground during wrestling and landed on his left shoulder. ⋯ Deep vein thrombosis has not been reported as a presenting symptom for posterior sternoclavicular dislocation. Orthopedic, trauma, and thoracic surgeons should be aware of this presentation and obtain a chest computed tomography scan with 3-dimensional reconstruction to confirm the diagnosis. In cases of posterior sternoclavicular dislocation with vascular compromise, patients should immediately undergo open reduction with or without internal fixation.
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Case Reports
Spontaneous hemorrhage in an upper lumbar synovial cyst causing subacute cauda equina syndrome.
Lumbar spine synovial cysts are becoming more frequent, and they are generally associated with degenerative lumbar spinal disease. They are common in lower lumbar lesions but rare in upper lumbar lesions. Several cases of hemorrhage into lower lumbar juxtafacet cysts after trauma or anticoagulation therapy have been reported in the literature. ⋯ Although several descriptions exist of hemorrhagic lumbar juxtafacet cysts after trauma or anticoagulant therapy, to the authors' knowledge, this is the first documented case of hemorrhage in an upper lumbar synovial cyst with no previous traumatic event or medication use. Magnetic resonance imaging was essential in making the preoperative diagnosis. Surgical removal of the cyst was an effective treatment.