Clinical orthopaedics and related research
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To investigate the risk of axillary nerve injury by the proximal locking screws in antegrade nailing of humeral fractures, the anatomy of the axillary nerve was examined in 20 fresh anatomic specimen humeri, which subsequently were nailed antegrade with specially designed humeral locked nails. The axillary nerve was found to be on average 45.6 mm below the tip of the greater tuberosity; it was jeopardized by insertion of the lower proximal locking screw in one of the 20 specimens. ⋯ The humeral geometry indicated that for the best linearity in the sagittal plane, an entry portal incorporating the superior margin of the olecranon fossa would be recommended for the 14 humeri with a distal humeral offset less than 4 mm, whereas a supracondylar entry portal would be recommended for the six humeri with an offset larger than 4 mm. For best linearity in the coronal plane, the entry portal and nailing direction should be more lateral in humeri with a smaller humeral elbow angle.
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Clin. Orthop. Relat. Res. · Nov 1999
Randomized Controlled Trial Clinical TrialSerum bone markers after intramedullary fixed tibial fractures.
Serum levels of bone markers were measured prospectively for 1 year in 30 adult patients with an intramedullary fixed tibial fracture. In a double blinded design, half of the patients received low intensity ultrasound. All fractures healed, although in seven of 30 the healing was delayed more than 6 months. ⋯ Patients with delayed healing had lower levels of bone specific alkaline phosphatase between 4 and 7 weeks than did patients with normal healing, although no such differences were seen for osteocalcin. The results indicate that low intensity ultrasound might slow bone resorption, although there is no visible effect on bone formation. Patients with delayed healing had adequate bone resorption but slower early bone formation than did patients with normal healing.
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Clin. Orthop. Relat. Res. · Oct 1999
Pain at the end of the stem after revision total knee arthroplasty.
A consecutive series of patients undergoing revision total knee arthroplasty was studied prospectively. Clinical and radiographic assessment was performed preoperatively, 6 and 12 months postoperatively, and annually thereafter. Evaluation consisted of a Knee Society clinical score and assessment of patient satisfaction. ⋯ There was no correlation between the stem diameter and the occurrence of pain; however, there was a trend for percent canal fill to be higher on the tibial side in patients with pain (71% versus 63%), but this was not statistically significant. Three of the 16 patients with cemented tibial stems (19%) experienced pain at the end of the stem. Patients with press fit stems who had pain at the end of the stem were more likely to express dissatisfaction with the surgical procedure than patients without pain at the end of the stem.
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Clin. Orthop. Relat. Res. · Oct 1999
Popliteal vessels in knee surgery. A magnetic resonance imaging study.
Popliteal artery injury during surgery of the knee is rare but can have devastating consequences. The position of knee flexion has been thought to be protective for the popliteal artery, allowing it to fall back from the knee joint. No prior study has provided in vivo cross sectional evidence of the behavior of the popliteal vessels during knee flexion with the effect of gravity. ⋯ Considerable variation in behavior of the vein and the artery was observed at the high tibial osteotomy cross sectional level and the total knee arthroplasty cross sectional level. In two knees at the high tibial osteotomy cross sectional level and in two knees at the total knee arthroplasty cross sectional, level the artery moved closer to the posterior tibia with knee flexion. Even with the effect of gravity included, knee flexion does not guarantee removal of the popliteal vessels from potential harm during surgery of the knee.
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Clin. Orthop. Relat. Res. · Oct 1999
Blood management in two-stage revision knee arthroplasty for deep prosthetic infection.
Treatment of infected total knee arthroplasty requires aggressive management to treat the infection and restore joint function. For patients with infected knee arthroplasties, a two-stage procedure is used that involves resection of the joint and placement of an antibiotic impregnated cement spacer followed by implantation of a new prosthetic 6 weeks later. Patients undergoing the two-stage procedure typically endure high allogeneic blood transfusion rates (82% to 88%) and progressive anemia because the two surgeries are spaced closely and because the infection precludes the use of alternatives to allogeneic blood. ⋯ After the first stage, allogeneic blood transfusion failed to improve postoperative hemoglobin levels enough to prevent transfusions associated with the second-stage. Patients undergoing two-stage total knee arthroplasty have anemia, and a substantial proportion of these patients require allogeneic blood transfusion at both stages. Thus, novel blood management practices are required to improve hemoglobin levels and reduce allogeneic transfusion rates in this patient population.