Experimental and computational studies on the femoral fracture risk for advanced core decompression.

BACKGROUND: Two questions are often addressed by orthopedists relating to core decompression procedure: 1) Is the core decompression procedure associated with a considerable lack of structural support of the bone? and 2) Is there an optimal region for the surgical entrance point for which the fracture risk would be lowest? As bioresorbable bone substitutes become more and more common and core decompression has been described in combination with them, the current study takes this into account. METHODS: Finite element model of a femur treated by core decompression with bone substitute was simulated and analyzed. In-vitro compression testing of femora was used to confirm finite element results. FINDINGS: The results showed that for core decompression with standard drilling in combination with artificial bone substitute refilling, daily activities (normal walking and walking downstairs) are not risky for femoral fracture. The femoral fracture risk increased successively when the entrance point is located further distal. The critical value of the deviation of the entrance point to a more distal part is about 20mm. INTERPRETATION: The study findings demonstrate that optimal entrance point should locate on the proximal subtrochanteric region in order to reduce the subtrochanteric fracture risk. Furthermore the consistent results of finite element and in-vitro testing imply that the simulations are sufficient.

Arthroscopic synovectomy and radiosynoviorthesis: a treatment option for recurrent arthritis symptoms in patients with pachydermoperiostosis.

Pachydermoperiostosis as the primary form of hypertrophic osteoarthropathy is a rare hereditary disorder with a number of characteristic findings, e.g. periosteal hypertrophy, digital clubbing and pachydermia. Further typical symptoms include arthritic manifestations in all major joints. Literature review showed that therapeutical approaches usually focus on medical therapy alleviating chronic polyarthritis by controlling inflammation. In the case presented in this report anti-inflammatory therapy appeared to have been insufficient since knee arthritis persisted. Arthroscopic synovectomy and radiosynoviorthesis were performed consecutively. Postoperative and follow-up examinations indicate that this combined therapy reduces pain, increases range of motion and improves overall mobility, and is thus of lasting benefit to the patient.