The Knee
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Multicenter Study
Revision of Oxford medial unicompartmental knee arthroplasty to total knee arthroplasty - results of a multicentre study.
The advantages of Unicompartmental Knee Replacement (UKR) over Total Knee Replacement (TKR) includes the preservation of soft tissue as well as bone stock, and better function with improved range of motion and more natural gait. It is therefore believed that the revision of failed UKR to TKR is technically easier than revision of failed TKR. In our study we tested this hypothesis by assessing the reconstruction requirements and early clinical and radiological outcome following the revision of UKR to TKR. ⋯ In 30 cases reconstruction for bone loss was not required whereas metal augmentation was used in two knees, contained peg defects in the femur were filled with cement in two knees and contained keel defects in the tibia were grafted using the bone from revision cuts in two knees. After a mean follow-up of 2 years, the mean 'total knee score' was 86.3 and the mean functional score was 78.5. These findings suggest that the complexity of operation and complications encountered during Oxford medial UKR revision and the clinical outcome compare favorably with those of TKR revision.
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Aetiology of Osgood-Schlatter disease (OSD) is still unknown. Relative length of the patellar articular surface with the length of the patella, relative height of the tibial tubercle with the sagittal diameter of the tibia, Insall-Salvati, Blackburne-Peel, and Caton-Deschamps indexes, as well as Grelsamer-morphology type of the patella were measured from preoperative plain X-rays in 82 knees of 20-year-old males with OSD and in 87 knees of 20-year-old male controls with normal MRI findings of the knee. Seventy-eight of the OSD patients had separate ossicles. ⋯ Tibial tuberosity was significantly higher among OSD patients, but was not correlated with the lengthening of the patella. An increased patellar height among OSD patients was shown by the Blackburne-Peel and Caton-Deschamps indexes (p<0.001) and the Insall-Salvati index (p=0.018). OSD patients exhibit elongated patellae and patellar tendons which may result from long-standing tension of the extensor apparatus during growth spurt, when femoral growth exceeds that of the anterior structures of the knee.
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The incidence of periprosthetic supracondylar femoral fractures around total knee arthroplasties (TKRs) is increasing. An acceptable treatment is to insert a supracondylar nail, but not all TKRs will permit this. An unofficial table of compatibilities is available from Smith and Nephew, but this has not been peer reviewed. ⋯ We have found that the notch position, rather than the notch size, was the most important factor in determining nail compatibility. Most of the TKRs commonly used in the UK will allow supracondylar nailing for fixation of periprosthetic fractures. There are, however, notable exceptions and our chart provides a quick and easy reference for knee surgeons involved in these cases.
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In this retrospective cohort, the results of step-cut tibial tubercle osteotomy (TTO) in 39 revision total knee arthroplasty, using the Continuum Knee System (CKS), are determined. In 39 revision, total knee arthroplasties, adequate exposure was obtained after step-cut TTO. All knees were recently reviewed for clinical and radiological results. ⋯ Another patient had posttraumatic avulsion of the tibial tubercle. No TTO-related extensor lag or tibial fracture occurred We conclude that, when adequate exposure cannot be obtained, step-cut TTO is a safe and reproducible procedure if strict attention is paid to technique and fixation. It does not compromise the functional results of TKA.
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Simultaneous bilateral avulsion fractures of the tibial tuberosity is a rare injury. Since it was first described in 1955, there have been eight similar cases. ⋯ Like the previous reports, our patient had a satisfactory result from open reduction and internal fixation of both fractures. Despite being bilateral, these injuries have a low complication rate and good outcome comparable with that of unilateral avulsion fractures of the tibial tuberosity.