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Total knee replacement in severe osteoarthritis usually requires extensive soft tissue releases often associated with considerable bleeding. In a prospective, randomised trial we compared postoperative conventional suction drainage versus four hour clamping drainage in 60 patients undergoing total knee arthroplasty for severe osteoarthritis. We compared blood loss, number of transfusions, postoperative complications and knee function and found significantly less postoperative blood loss through the drains ( p<0.001), and fewer blood transfusions ( p=0.09) were needed in the clamped group. We conclude that clamping drainage after total knee arthroplasty in severe osteoarthritis reduces blood loss through the drains and the need for blood transfusions.Résumé La prothèse totale du genou dans les gonarthroses sévères nécessite souvent une résection tissulaire importante, celle-ci étant souvent associée à un saignement important. Nous avons réalisé une étude prospective randomisée comparant le drainage conventionnel post-opératoire versus clampage du drain durant 4 heures chez 60 patients ayant bénéficié d'une prothèse totale du genou pour une gonarthrose importante. Nous avons comparé les pertes sanguines, le nombre de transfusion, les complications post-opératoires, la fonction du genou. Nous avons observé qu'il y avait beaucoup moins de pertes sanguines dans les drains (p<0.001) et beaucoup moins de transfusions (p=0.009) dans le groupe des patients dont le drain avait été clampé pendant 4 heures. Nous pouvons conclure que le clampage du drain après prothèse totale du genou dans les gonarthroses sévères permet de réduire les pertes sanguines et le nombre de transfusions.

The results of minimally invasive techniques used for total knee replacement are controversial. Despite reported advantages such as faster recovery, there are some concerns regarding component positioning. We compared mini-midvastus versus medial parapatellar arthrotomy with respect to component position and functional results. We included 70 osteoarthritis total knee replacement patients in our study. Patients were randomised for the approach. We recorded Knee Society scores before and after the surgery and radiological component position. Patients were followed up to 12 weeks after the surgery. We found that the mini-midvastus approach was associated with better Knee Society scores six weeks after surgery; after 12 weeks the difference was not statistically significant. We found no difference related to the approach in radiological component position. The mini-midvastus approach is associated with faster recovery and reproduces the same accuracy in component positioning as the medial parapatellar approach.

This study investigated bone regeneration in the femoral neck canal of osteoporotic rats using a novel animal model. A calcium sulphate (CS)/hydroxyapatite (HA) carrier was used to deliver a bisphosphonate, zoledronic acid (ZA), locally, with or without added recombinant human bone morphogenic protein-2 (rhBMP-2). Twenty-eight-week-old ovariectomized Sprague-Dawley rats were used. A 1 mm diameter and 8 mm long defect was created in the femoral neck by drilling from the lateral cortex in the axis of the femoral neck, leaving the surrounding cortex intact. Three treatment groups and one control group were used: (1) CS/HA alone, (2) CS/HA + ZA (10 μg) (3) CS/HA + ZA (10 μg) + rhBMP-2 (4 μg), and (4) empty defect (control). The bone formation was assessed at 4 weeks post surgery using in vivo micro computed tomography (micro-CT). At 8 weeks post surgery, the animals were sacrificed, and both defect and contralateral femurs were subjected to micro-CT, mechanical testing, and histology. Micro-CT results showed that the combination of CS/HA with ZA or ZA + rhBMP-2 increased the bone formation in the defect when compared to the other groups and to the contralateral hips. Evidence of new dense bone formation in CS/HA + ZA and CS/HA + ZA + rhBMP-2 groups was seen histologically. Mechanical testing results showed no differences in the load to fracture between the treatments in either of the treated or contralateral legs. The CS/HA biomaterial can be used as a carrier for ZA and rhBMP-2 to regenerate bone in the femoral neck canal of osteoporotic rats.

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