Introduction: Heterotopic ossification around the tip of intramedullary nail is a well-known complication of the nailing technique, since the time of Kuntscher. Nevertheless, little attention has been given to it in the current literature.

Aim: The evaluation of the incidence, clinical significance and possible risk factors of this complication after intramedullary nailing of femur with reaming.

Material – Method: For this purpose we studied the X-rays and medical charts of 30 patients who had undergone the above procedure at the Orthopaedic Departments of both Institutions mentioned above, between 2000 and 2002. The preoperative diagnoses were diaphyseal fracture: 13 patients, subtrochanteric fracture: 7 patients, refracture of femur: 1 patient, non-union: 5 patients, imminent fracture (due to intraosseous lesion): 2 patients, failure of previous fixation: 2 patients. In 18 cases the G.K. nail was used, whereas, in the remaining twelve, the long gamma nail was used. The patients’ follow-up ranged from 6 to 18 months (mean: 11 months). The presence of heterotopic bone around the proximal tip of the nail was graded according to the grading system of Brumback et al.

Results: In 12 patients (40%) there was no development of heterotopic bone around the proximal tip of the nail. In 14 patients (47%) minimal and moderate grade of heterotopic ossification was developed (grade I and II). Finally, in 4 patients (13%) there was significant heterotopic bone formation (grade III). None of the above patients presented with any significant limitation of ipsilateral hip joint motion. There was no correlation between type of fracture, type of nail fixation, presence of concomitant injuries, nail prominence above the tip of greater trochanter and the formation of heterotopic bone. The only positive correlation was between male sex and the presence of heterotopic ossification.

Conclusion: Heterotopic ossification of minimal and moderate grade is a common complication of the technique of intramedullary nailing of femur, without any further clinical significance. The formation of heterotopic bone of significant degree in the hip region, though it does not results in serious clinical problems for the patient, it will surely make future extraction of the nail difficult.

Introduction: High tibial osteotomy is an established procedure for the mid-term treatment of unicompartmental osteoarthritis of the knee. Nevertheless, it produces anatomic alterations of the proximal part of tibia, which might affect the later performance of TKR. These anatomic changes are basically patella infera and medialization of the tibial medullary canal with respect to the tibial plateau (tibial condilar offset).

Material and Method: The purpose of the present retrospective study is the evaluation of the above mentioned anatomic changes, caused by high tibial valgus osteotomy (Mittelmeier’s technique). For this purpose we studied the X-rays of 44 kness (pre-op, p-op and 1 year p-op) that had under gone the above procedure.

Results: We didn’t find any statistically significant difference of the postoperative position of the patella with respect to the preoperative one, whereas there was definite medialization of the tibial anatomic axis with respect to the preoperative situation. The latter change was directly correlated with the degree of valgus correction. The mean change of the tibial anatomic axis (as estimated by the value of the tibial condylar offset ratio) was 15%.

Conclusions: Although Mittelmeier’s high tibial valgus osteotomy does not cause any significant alteration of the position of the patella, it does alter the relationship of the tibial medullary canal with respect to the tibial plateau in direct correlation with the degree of valgus correction. Thus, the performance of TKR after proximal tibial osteotomy necessitates a thorough preoperative plan and the selection of the appropriate implant.