Abstract
The patella is an important component of the extensor mechanism of the knee. It serves to increase the mechanical advantage of the quadriceps muscle by increasing its lever arm. Therefore, if possible, when the patella is fractured, it should be repaired rather than excised. Present surgical techniques for the patellar fractures utilizes principles of anatomic reduction with repair of any associated retinacular tears, rigid internal fixation, and early institution of joint motion exercises. To compare the efficacies of the commonly used wiring techniques, we performed tension tests with transversely bisected patellar models fixed with circumferential wiring, Magnuson wiring, modified tension band wiring and modified tension band wiring combined with circumferential wiring. Also, we reviewed 66 surgically treated patellar fractures from Jan. 1984 to Dec. 1988, when we had given every effort to preserve the patella using modified tension band wiring or modified tension band wiring combined with circumferential wiring. l. According to the results of the tension tests, modified tension band wiring and Magnuson wiring were more rigid than circumferential wiring and the rigidity of modified tension band wiring was much increased when combined with circumferential wiring. 2. Of the 66 cases, 46 cases were treated with modified tension band wiring combined with circumferential wiring, and the remainder were treated with modified tension band wiring. 3. On the whole, good and excellent results were achieved in 87.9% (58 cases). Unsatisfactory results were obtained in 15.0% of cases treated with modified tension band wiring and in 10.9% of cases treated with modified tension band wiring combined with circumferential wiring. 4. Most of the unsatisfactory cases were so severely comminuted that could not be achieved anatomic reduction, rigid internal fixation and early joint motion exercises