Introduction: Filling bone defects with Polymethylmetaacrylate (PMMA) has been a easy, safe and reliable technique for past four decade. Newly developed Calcium Phosphate Paste (CPP) is a mixture of alpfa Tri Calcium Phsphate (TCP), Tetra Calcium Phosphate, Calcium Hydrogen Phosphate and Hydroxyapatite. This paste hardens in 10 minutes and its stffness increases to 80Mpa in seven days. It generates no heat, no gas and requires no organic solvents. In process of hardening, the TCP structure changes to Hydroxyapatite.

Materials and methods: We have used CPP in two TKA cases associate with bone defect, and 14 fracture cases. In a MRSA infected revision TKA case, reconstruction was performed with PMMA-VCM articulated spacers, and they was fixed to bone with CPP-VCM. MRSA infection has been well controlled and weight bearing could be done in 10 days after surgery. In another TKA case, large bone necrosis in femoral condyle was filled with CPP and Cementless inplant were placed on it. Seven days later, this patient could walk with a cane.

Results: CPP filled in bones were not absorbed for a year, and exess CPP in soft tissue were absorbed in several weeks. In 16 cases no side effects were observed during as long as one year.

Conclusion: Handling CPP is much easier than Hydroxyapatite brick or granule. CPP can be useful for total joint arthroplasty, especially in large bone defect or infected cases. It can replace a part of PMMA as a bone cement for implants in the near future.

Prevention of joint dislocation after total hip arthroplasty (THA) is important to keep suitable relationships between surgeons and patients. Capsule has an essential role for stability of joint, especially in hip. Reserving a part of capsule in THA can increase stability. We examined the effect of partial capsulotomy in hip joint for prevention of dislocations after THA.

In 178 primary THA for osteoarthritis, partial capsulotomy were performed in 92 cases and generous capsulectomy in 86 cases from 1993 to 2001. Age, gender, pre-operative complications of both groups were matched. All THA were performed from a posterior approach, and in case of partial capsulotomy, anterior one third of hip joint capsule was reserved before placing acetabular component. Posterior capsulorrhaphy was not performed.

No hip dislocations have been seen in partial capsulotomy cases, and four posterior dislocations following THA were observed in general capsulectomy cases during one to nine year follow up.

Soft tissue imbalance of THA is most at risk for dislocation. The present study showed a satisfying result of partial capsulotomy for prevention of THA dislocation. Residual hip joint capsule can increase joint stability and can resist to dislocation after THA in osteoarthritis.