Purpose: To test a CaSO4/CaPO4-TCP composite bone graft substitute in a crtically sized bone defect.

Method: Twenty dogs had a contained medullary defect created in the proximal humerus. In ten dogs, the defect was treated with CaSO4/CaPO4-TCP composite graft (PRO-DENSE^™, Wright Medical) and studied for 13 weeks (N=5) and 26 weeks (N=5). In the other ten dogs, the defect was treated with autograft and followed for 13 weeks. An additional ten unoperated humeri were used to establish the properties of normal canine bone. The area fraction, ultimate compressive stress and modulus of elasticity of bone in the experimental and normal humeri were quantified using histomorphometric and mechanical methods and analyzed using the Mann-Whitney test.

Results: At 13 weeks, the area fraction, compressive stress and modulus of elasticity of new bone in the defects was several-fold greater (p ≤ 0.005) using CaSO4/CaPO4-TCP composite graft compared to defects treated with autograft. The area fraction and compressive stress of new bone using CaSO4/CaPO4-TCP composite graft were also several fold greater (p≤.009) compared to normal bone, but there was no difference in the modulus of elasticity. Although the compressive stress was still greater (p=0.047) at 26 weeks for defects treated with the composite graft compared to normal bone, the regenerated bone had remodeled to a normal cancellous architecture, incorporating minute fragments of residual graft.

Conclusion: CaSO4/CaPO4-TCP composite graft produced a several-fold greater amount and strength of bone than autogenous graft bone at 13 weeks. There was no modulus mismatch between the regenerated and native cancellous bone. The composite graft holds promise for non-load bearing applications where dense, strong bone formation at earlier time points would be advantageous, potentially resulting in quicker return to activity.

Introduction and Aims: The treatment of Giant Cell Tumor (GCT) of bone ranges from resection to intra-lesional excision. The latter procedure preserves the joint and function. The purpose of this paper is to review functional and oncological outcomes for GCT treated by intralesional excision.

Method: The medical records including radiology and pathology of 40 consecutive patients with GCT were retrospectively reviewed. Demographics, complications, tumor local control were determined. Functional evaluation using the MSTS system was performed on 23 patients. The data was subject to statistical analysis.

Results: Forty patients (19M/21F). Mean age 28 years. Sites: femur 17, tibia 14, radius five, other four. Mean follow-up 90.3 months (26–178). Functional outcome: 93.2% (50–100). Complications: DJD two, fracture one. Recurrence: five (12.5%). Recurrence sites: Tibia two, femur one, radius one, and talus one. Recurrence treatment: 1/5 resection, 4/5 repeat intralesional excision. Recurrence outcome: 5/5 NED (mean 58.2 months).

Conclusion: GCT treated by intralesional excision had excellent functional and oncological outcomes. The joint was preserved in most patients (95%) except due to recurrence 1 and fracture 1. The recurrences were successfully treated by repeat excision in 4/5 patients. Intralesional excision should be considered the preferred treatment for most giant cell tumors.

Text: Chronic osteomyelitis is a serious condition. The infection can be difficult to eradicate and destroy significant bone. Usual therapy includes debridement, systemic antibiotics and local antibiotic delivery with polymethylmethacrylate (PMMA). PMMA needs to be removed and does not aid in bone repair.

Purpose: To review the use of calcium sulfate (OSTE-OSET® loaded with Vancomycin 3.2% or Tobramycin 3.8%) as an antibiotic delivery and bone repair implant.

Methods: Six consecutive patients were reviewed. Clinical records, radiographs, bone repair, sedimentation rate, functional outcome (Enneking MSTS system) were evaluated. All patients were treated with a surgical debridement, degradable implants and six weeks of systemic antibiotics.

Results: Six patients (3M/3F), mean age 50 years. Site; tibia 3, femur 3. Organism: Staph Aureus 5, mixed 1. Defect size; 40 cubic centimeters (12–60). Pre op sed rate; 54 (22–105). Local antibiotic; tobramycin 5, tobra+vancomycin 1. Follow-up; 22 months (12–31). Follow up sed rate; 8, Follow-up defect size; 2.5 cubic centimeters. Bone repair, 91%. Follow-up functional score; 27.5/30. No fractures, infection relapses or additional surgery to date.

Discussion: Local antibiotic delivery with calcium sulfate (OSTEOSET®) proved to be effective for bone repair. This implant does not need to be removed and may be an adjunct to systemic antibiotics for chronic osteomyelitis.

We present the case of a 65-year-old man who developed a malignant fibrous histiocytoma at the lesser trochanter five months after a cementless hip replacement. We have reviewed reports of similar cases and discuss them in terms of the possible mechanisms of sarcomatous degeneration and the latency of such changes.