The Knee
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Randomized Controlled Trial Comparative Study
A prospective, randomised study comparing two techniques of autologous chondrocyte implantation for osteochondral defects in the knee: Periosteum covered versus type I/III collagen covered.
The results for autologous chondrocyte implantation (ACI) in the treatment of full thickness chondral defects in the knee are encouraging. At present two techniques have been described to retain the chondrocyte suspension within the defect. The first involves using a periosteal cover (ACI-P) and the second involves using a type I/III collagen membrane (ACI-C). To the authors knowledge there are no comparative studies of these two techniques in the current literature. We have therefore undertaken such a study to establish if there is a difference between the 2 techniques based on a clinical and arthroscopic assessment. ⋯ This study has shown no statistical difference between the clinical outcome of ACI-C versus ACI-P at 2 years. A significant number of patients who had the ACI-P required shaving of a hypertrophied graft. We conclude that there is no advantage in using periosteum as a cover for retaining chondrocytes within an osteochondral defect; as a result we advocate the use of an alternative cover such as a manufactured type I/III collagen membrane.
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To determine if the functional outcome of total knee replacement (TKR) was affected by the level of preoperative symptom severity, the association between preoperative Oxford Knee Scores (OKS), and 2 year OKS, American Knee Society clinical and function scores (AKSS) was assessed. Data were prospectively collected on 45 cases who had single joint osteoarthritis and no other comorbidities. We have specifically focused on patients with single knee involvement to remove the effect of multiple joint involvement and comorbidities on the OKS. ⋯ Rather than all patients achieving uniform results post-TKR, patients with more severe symptoms achieved poorer absolute outcomes. The Spearman correlation coefficient between pre- and postoperative OKS was r = 0.4 (p = 0.006). Although the results suggest that waiting too long before intervention compromises the final outcome, a correlation of 0.4 is not strong enough to necessitate change in current practice.
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Randomized Controlled Trial
Tranexamic acid reduces early post-operative blood loss after total knee arthroplasty: a prospective randomised controlled trial of 29 patients.
Extensive blood loss related to knee arthroplasty is quite normal and many patients require blood transfusions. Surgery and the use of pneumatic tourniquets lead to an increase in the activity of the fibrinolytic system, which in turn may accentuate the blood loss. Drugs that inhibit the fibrinolytic system may thus be used to reduce blood loss. Tranexamic acid (TA) acts by binding to one of the enzymes at the start of the coagulation cascade, so inhibiting the fibrinolytic system. A concern is that this inhibition may have the side effect of increasing thromboembolic disease, a common complication of joint replacement surgery. We aimed to confirm the reductions in blood loss and to assess the impact of TA usage on clinical and sub-clinical DVT. ⋯ One injection of 15 mg/kg of tranexamic given at the time of cementing the prosthesis in total knee arthroplasty, before deflation of the tourniquet, significantly decreases the amount of blood loss in the early post-operative period. The treatment was not associated with an increase in thromboembolic complications.
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This study records the length of hospital stay of 50 total knee arthroplasty patients involved in an accelerated postoperative rehabilitation protocol, and a control group of patients undergoing routine rehabilitation. This protocol involved modifications to normal knee replacement procedure, including infiltration of bupivacaine and adrenaline to the divided tissue layers at the time of surgery, spinal anaesthesia, and mobilisation on the day of surgery. These modifications were combined with an organised multidisciplinary approach anticipating issues that may delay discharge. ⋯ American Knee Society and Oxford knee scores demonstrated good levels of knee function at 6 weeks post surgery. In addition, it was noted that no postoperative blood transfusions were required. This is regarded as a significant further benefit.
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To determine the efficacy of autologous chondrocyte implantation (ACI) in treating focal chondral defects of the knee, we reviewed the 2-year treatment outcome of ACI in 53 patients (72 lesions) through clinical evaluation, MRI, second-look arthroscopy and biopsies obtained. Improvement in mean subjective score from preoperative (37.6) to 12 months (56.4) and 24 (60.1) months post-ACI were observed. Knee function levels also improved [86% International Cartilage Repair Society (ICRS) III/IV to 66.6% I/II] from preoperative period to 24 months postimplantation. ⋯ At 24 months, further improvements to 97%, 97%, 95.6% and 92.6%, respectively, were observed. Second-look arthroscopy carried out in 22 knees (32 lesions) demonstrated all grafts to be normal/nearly normal based on the International Cartilage Repair Society (ICRS) visual repair assessment while core biopsies from 20 lesions demonstrated 13 grafts to have hyaline/hyaline-like tissue. Improvement in clinical and MRI findings obtained from second-look arthroscopy and core biopsies evaluated indicate that, at 24 months post-ACI, the resurfaced focal chondral defects of the knee remained intact and continued to function well.