The Knee
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Comparative Study
A new press-fit stem concept to reduce the risk of end-of-stem pain at revision TKA: a pre-clinical study.
Revision total knee arthroplasty presents numerous technical challenges, with lower patient outcomes compared with those obtained in primary surgery. Extended stems have been used in revision total knee arthroplasty to improve component alignment and fixation. Hybrid fixation with cemented tibial tray and press-fit stem has shown good results. One of the disadvantages of this technique is pain related to the presence of a cementless diaphyseal engaging stem, often designated as end-of-stem pain. Patients with this pain have reported a decrease in overall satisfaction, as well as demonstrate a lower clinical outcome score. Clinical findings suggest that stem material and design are important factors in the development of end-of-stem pain. Therefore, a question can be raised: can a novel press-fit stem concept minimize bone strain changes at the stem tip? The hypothesis here considered lies upon the fact, that if periosteal cortex strain changes are minimized at the stem tip comparatively to the intact situation, the risk of end-of-stem pain might be minimized. ⋯ The results demonstrated that the new stem concept has the ability to minimize strain changes induced by the stem tip at the distal periosteal cortex and consequently, at the periosteal layer of bone tissue, which is highly pain sensitive, probably contributing to the reduction of the risk of end-of-stem pain.
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The aim of this study was to analyze the clinical outcome obtained with arthroscopic second generation autologous chondrocyte implantation (ACI) associated with bone grafting for the treatment of knee osteochondritis dissecans (OCD) at medium term follow-up. ⋯ Second generation ACI associated with bone grafting is a valid treatment option for knee OCD and may offer a good and stable clinical outcome at mean 6 years of follow-up. Further studies are needed to confirm the results over time, and determine if there is only a symptomatic improvement, or if this procedure may also prevent or delay further knee degeneration.
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Comparative Study
Patellofemoral joint stress during running in females with and without patellofemoral pain.
Patellofemoral pain (PFP) is a common complaint among female runners. The etiology for PFP is frequently associated with increased patellofemoral joint stress (PFJS) and altered hip and knee joint kinematics during running. However, whether PFJS during running is increased among runners with PFP is unknown. ⋯ However, females with PFP demonstrated hip internal rotation that was 6° greater (P=0.04) when ground reaction forces were greatest. The extent these results are influenced by compensations for pain is unclear. However, if increased PFJS contributes to the etiology or exacerbation of PFP, interventions to minimize altered transverse plane hip kinematics may be indicated among runners who demonstrate this characteristic.
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Acute patellar dislocation is a severe injury to the knee and usually manifests with symptoms such as giving way, a sensation of lateral displacement of the patella accompanied by hemarthrosis and tenderness over the medial epicondylar region to palpation. Spontaneous reduction of the patella makes the diagnosis more difficult in initial evaluation. Radiographs often show a small bony avulsion at the medial border of the patella, which may represent an injury to the medial restraints. ⋯ The medial patellofemoral ligament (MPFL) may be avulsed distally, proximally or sustain in interstitial tear. Arthroscopic findings include hematoma and chondral or osteochondral lesions located on the central or medial facet of the patella or on the anterior lateral femoral condyle. We report a case of a patellar avulsion of medial patellofemoral ligament in a skeletally immature patient.
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Randomized Controlled Trial Comparative Study
Reducing blood loss in primary knee arthroplasty: a prospective randomised controlled trial of tranexamic acid and fibrin spray.
A prospective, randomised controlled trial compared the effects of two medications intended to reduce blood loss from total knee arthroplasty. Patients were randomised to one of the following three treatment groups: 10mg/kg tranexamic acid at given at induction of anaesthesia, 10 ml of fibrin spray administered topically during surgery, or to a control group receiving neither treatment. Sixty six patients underwent elective cemented total knee arthroplasty; computer navigation was used in all cases. ⋯ The fibrin spray led to a significant reduction in blood loss compared to control (p=0.007). The effect of tranexamic acid did not reach significance (p=0.173). We conclude that fibrin spray was effective in reducing blood loss but that with a study of this power, we were unable to detect an effect of tranexamic acid in cemented navigated total knee replacement at the dose used.