Long-term results of reconstruction with pelvic allografts after wide resection of pelvic sarcomas

Reconstruction after the resection of a pelvic tumor is a challenging procedure in orthopedic oncology. The main advantage of allograft reconstruction is restoration of the bony architecture of the complex pelvic region. However, high complication rates such as infection and allograft resorption had been reported in the literature. In this study, we aimed to retrospectively review nine patients treated with pelvic resection and structural pelvic allograft reconstruction. Functional results, complications, and survival of the patients and the allografts were evaluated. At a mean follow-up of 79 months, three patients were dead. Major complications were detected in eight of the nine patients. Infection (four of the nine patients) and allograft resorption (three of the nine patients) were the most common causes of failure. The cumulative survival of the patients was 66.7 percent at 70 months. However, allograft survival was only 26.7 percent at 60 months. Mean MSTS score was 69. In conclusion, we suggest that other reconstruction options should be preferred after pelvic resections because of the high complication rates associated with massive allograft reconstruction.

Development of the femoral trochlear groove in rabbits with patellar malposition

PURPOSE

The geometry of the trochlear groove is considered to be an important determinant in the pathogenesis of the patellofemoral joint disorders. However, the effect of patellar position during the development of the femoral trochlear groove is unclear. This animal study aimed to investigate the relationship between the position of the patella and development of the femoral trochlear groove in growing rabbits.

METHODS

Thirty-two knees from 16 rabbits were included in this study and were divided into two groups. First group consisted of the left knees and was used as a control group with no surgical interventions. The second group involved the right knees on which patellar tendon Z-plasty lengthening was performed to cause patellar malposition (patella alta) before 1 month of age. Computed tomographic (CT) evaluations of both knees were obtained when the animals were 1 month age before the surgical intervention and also at 6 months after the surgical intervention. Angle and depth measurements were acquired from the proximal, middle, and distal reference points along the femoral trochlear groove. After the CT scan acquisition at 6 months following the surgical procedures, rabbits were killed and additional measurements of the trochlear groove angles were performed manually.

RESULTS

The mean middle and distal trochlear groove angles for the experiment group with patella alta were significantly higher compared to that of control group (p < 0.017). The increase in mean trochlear depth for the animals in the control group was found to be significantly higher compared to experiment group at the distal zone (p < 0.017).

CONCLUSION

Distal femoral groove with an inadequately positioned patella becomes more flattened and this may be a predisposing factor for patellar instability.

LEVEL OF EVIDENCE

Controlled laboratory study, Level II.