Ketamine has been used in combination with a variety of other agents for intra-articular analgesia, with promising results. However, although it has been shown to be toxic to various types of cell, there is no available information on the effects of ketamine on chondrocytes.

We conducted a prospective randomised controlled study to evaluate the effects of ketamine on cultured chondrocytes isolated from rat articular cartilage. The cultured cells were treated with 0.125 mM, 0.250 mM, 0.5 mM, 1 mM and 2 mM of ketamine respectively for 6 h, 24 hours and 48 hours, and compared with controls. Changes of apoptosis were evaluated using fluorescence microscopy with a 490 nm excitation wavelength. Apoptosis and eventual necrosis were seen at each concentration. The percentage viability of the cells was inversely proportional to both the duration and dose of treatment (p = 0.002 and p = 0.009). Doses of 0.5 mM, 1 mM and 2mM were absolutely toxic.

We concluded that in the absence of solid data to support the efficacy of intra-articular ketamine for the control of pain, and the toxic effects of ketamine on cultured chondrocytes shown by this study, intra-articular ketamine, either alone or in combination with other agents, should not be used to control pain.

Cite this article: Bone Joint J 2014; 96-B:989–94.

The management of nonunion following high tibial osteotomy by total knee replacement (TKR) has been reported previously. We have extended the treatment to embrace cases with an infected high tibial osteotomy by performing an initial debridement with a period of antibiotic treatment followed by TKR. We have reviewed the results of seven knees in six patients with a mean follow-up of 40.5 months (20 to 57) after the staged TKR. At the latest follow-up, all the pseudarthroses had healed and there had been no recurrence of infection. The mean Hospital for Special Surgery knee score improved from 51.2 (35 to 73) to a mean of 91.7 (84 to 98) at final review.

Management of nonunion following high tibial osteotomy with a TKR can be extended to infected cases when treated in two stages with a debridement and antibiotic therapy prior to TKR.

Introduction: Platelet-rich plasma (PRP) is a platelet concentration obtained from a few millilitres of blood. It releases several growth factors and can enhance tissue repair(). The aim of the study was to evaluate the efficacy and the safety of PRP in the treatment of experimental induced muscle lesions.

Materials and Methods: 22 adult Wistar rats were used. Blood collected from 2 rats was mixed with citrate-phosphate-dextrose and centrifuged to a gel consistency. Growth factor release was stimulated by the addition of CaCl and thrombin. Identical bilateral incisions were performed on the longissimum dorsi muscle of 20 Wistar rats. Each site was marked by placing a hollow PVC vessel containing PRP on the bottom of the defect. An empty marker was placed on the bottom of the contralateral lesion, as control. Animals were killed 40 or 60 days from surgery. Muscle samples were stained with haematoxylin-eosin. Histomorhometric parameters investigated were: number of regenerating fibres, amount of neoangiogenesis and fibrous tissue, presence of inflammatory cells, metaplasia, calcification and ossification (Leika, Quantimet SD).

Results: Treated muscles exhibited greater neoangiogenesis and a larger number of miocytes in regenerating phase compared with controls. Both groups showed a similar amount of fibrous tissue and some inflammatory cells. Metaplasia, ossification or heterotopic calcification were seen in none of the samples.

Conclusions: To our knowledge this is the first investigation of PRP in muscle healing. Data showed that PRP is effective in improve muscle healing without adverse local effects. Additional experiments are in progress in view of a clinical trial.