There were 12 patients in the common group and 9 patients in the cable group. Both groups of patients were AO34C3 patellar fracture. The age, sex ratio, trauma mechanism, operation time, free articular fragment, comorbidity and follow-up time of the two groups had no significant statistical difference (P>0.05). (table 1)
1. The mean age of the common group was 53.5±19.3 years (range 20-83 years), while the mean age of the cable group was 39.0±16.7 years (range 20-64 years).
2. There were 9 males and 3 females in the common group and 8 males and 1 female in the cable group.
3. 9 patients in the common group were injured due to traffic accidents, 3 were injured due to tumbling and kneeling, 7 patients in the cable group were injured due to traffic accidents, and 2 were injured due to tumbling and kneeling.
4. In the common group, 5 patients had free articular fragment, while in the cable group, 3 patients had free articular fragment.
5. In the common group, 4 patients had combined injuries in other parts, 1 case had rib fracture, 2 cases had unilateral radial fracture, and 1 case had bilateral radial fracture and brain injury. In the cable group, 3 patients had combined injuries in other parts, 2 cases had brain trauma and 1 case had ipsilateral femoral shaft fracture.
6. The mean operation time was 61.25±4.54 minutes (range 55-70 minutes) in the common group and 62.51±4.10 minutes (range 55-68 minutes) in the cable group.
7. The mean follow-up time of the common group was 20.75±2.70 months ( range 18-24 months). The mean follow-up time of the cable group was 21.00±2.60 months ( range 18-24 months).
The clinical results of the two groups, (such as Bostman[5] total score and its specific individual score, the excellent and good ratio, the complications, and the bone union time, etc.) had no significant statistical difference (P>0.05). (table 2).
1. Both groups of patients had no obvious limitation in the range of knee joint movement,.
2. In terms of knee joint pain, 4 patients in the common group had slight pain after overwork. 3 patients in the cable group had slight pain.
3. Both groups of patients could return to their original work.
4. There was no obvious quadriceps femoris atrophy in both groups.
5. Both groups of patients didn’t need auxiliary tools to walk.
6. 3 patients of the common group and 2 patients of the cable group had joint effusion occasionally, because the joint surface was not smooth enough.
7. Both groups of patients did not have giving way.
8. Because of the uneven articular surface, 3 patients in the common group and 2 patients in the cable group had slight discomfort when they climbed the stairs.
9. The mean Bostman score in the common group was 28.50±2.28 points (range 25-30 points). The mean Bostman score in the cable group was 28.56±2.24 points (range 25-30 points).
10. 8 patients got excellent results and 4 got good results in the common group. The cable group had 6 excellent outcomes and 3 good outcomes.
11. As for complications, the implant loosening and displacement was discovered in 1 patient, the uneven patellar articular surface were found in 3 patients in 12months after in the common group. In the cable group, 2 patients had implant loosening 3 months after operation. The uneven patellar articular surface of 2 patients were found 12 months after operation. However, there was no cable broken, or the cable cut out of the bone.
12. According to clinical and radiographic results, all patients achieved bony union by 2.44±0.53 months (range 2–3 months) in the common group and 2.50±0.52months (range 2–3 months) in the cable group.
It can be seen that there is no significant statistical difference between the two groups, no matter the demographic data before operation or the results after operation. However, the implementation of the additional cable fixation avoids the adverse consequences caused by external fixation when internal fixation of patellar fracture is insufficient.