The diagnosis of Charcot arthropathy in the knee is rare. However, there is an increasing number of diabetic patients, and they are living longer due to improvements in treatment. Because neuropathic arthropathy is a late effect of peripheral neuropathy, we can expect an increasing incidence of neuropathic arthropathy. Total knee arthroplasty is the preferred choice of treatment by patients, although it may also be associated with a high incidence of serious complications. This case report presents a young female with diabetes mellitus and Charcot arthropathy of the knee managed by total knee arthroplasty and a literature review. The report encompasses a 5-year follow-up of the patient, from the first contact after knee distortion through diagnosis of Charcot arthropathy and the performance of total knee arthroplasty with outpatient controls. The diagnosis was established on the basis of the rapid destruction of the medial tibial condyle after knee distortion in a patient with neuropathy. Neuropathic arthropathy was confirmed by histology. The patient refused knee fusion and total knee arthroplasty was performed. The patient quickly achieved a painless, stable knee with a 130-degree range of motion. However, a radiolucent line appeared under the tibial component due to premature weight-bearing. The patient was ordered to refrain from weight-bearing for the next 3 months, and the knee was healed. While the management of Charcot arthropathy in the knee remains controversial, total knee arthroplasty is not a contraindication. Early diagnosis, appropriate choice of implant and operative technique, and long-term weight protection are essential.

This study aims to evaluate in detail the biological osteoconductive properties of the low-temperature synthetic porous calcium-deficient hydroxyapatite and to compare it with the biological apatite. Bone reactions to granules of similar sizes of the low-temperature hydroxyapatite and commercially available non-sintered deproteinized bovine bone were compared. Two different temperatures were used to fabricate two batches of newly developed porous hydroxyapatite with different carbonate groups content and specific surface area. The histological analysis of specimens with histomorphometry was performed at different time after in vivo implantation. Based on histological analysis, the level of bone formation in the spaces between the implanted granules and through the interconnected pores of all implanted materials within a cortical region (bone area ingrowth 72-85 %) was several-fold higher than within a cancellous bone site (bone area ingrowth 16-28 %) at three and six months after implantation. Within the cancellous bone site, bone coverage of the implanted material at six months was significantly higher in hydroxyapatite material fabricated using low-temperature synthesis and subsequent processing at 150°C than in hydroxyapatite scaffold developed using low-temperature synthesis with subsequent processing at 700°C or deproteinized bovine bone. According to our study, the bioactive properties of the low-temperature calcium-deficient hydroxyapatite are comparable with the biological apatite. The favourable influence of a high specific surface area of a low-temperature calcium-deficient hydroxyapatite on in vivo bone formation was emphasized.

The purpose of this prospective controlled study was to compare healing quality following the implantation of ultraporous β-tricalcium phosphate, containing either expanded autologous mesenchymal stromal cells (trial group, 9 patients) or β-tricalcium phosphate alone (control group, 9 patients), into femoral defects during revision total hip arthroplasty. Both groups were assessed using the Harris Hip Score, radiography, and DEXA scanning at 6 weeks and 3, 6, and 12 months postoperatively. A significant difference in the bone defect healing was observed between both groups of patients (P < 0.05). In the trial group, trabecular remodeling was found in all nine patients and in the control group, in 1 patient only. Whereas, over the 12-month follow-up period, no significant difference was observed between both groups of patients in terms of the resorption of β-tricalcium phosphate, the significant differences were documented in the presence of radiolucency and bone trabeculation through the defect (P < 0.05). Using autologous mesenchymal stromal cells combined with a β-tricalcium phosphate scaffold is a feasible, safe, and effective approach for management of bone defects with compromised microenvironment. The clinical trial was registered at the EU Clinical Trials Register before patient recruitment has begun (EudraCT number 2012-005599-33).

The implantation of the nonresorbable glass-ceramic material into the diaphyseal defects of long bones is not suitable based on our study.