Treatment of transverse patella fractures by cannulated screws with tension band compared with modified tension band wiring

Abstract

Objective: To analyze and compare the results of modified tension band wiring and cannulated screws with tension band wiring concerning bony union, post-operative complications, range of movements of knee and time of recovery and compare both the modalities. Design: Prospective randomized control trial. A study done at: NDMC medical college and Hindu Rao hospital, Delhi, India Material and Methods: This study is a prospective randomized control, during the period from September 2019 to September 2020. This study consists of 50 cases of fracture patella divided randomized alternatively in two groups, Group A with 25 cases treated by Modified tension band wiring and group B with 25 cases treated by Cannulated screw with tension band wiring. Data for this study were collected in a pre-test proforma and details were included with subsequent pre-planned follow-ups at 1, 3, 6 and 12 months. Data were mainly analysed to assess post- operative interfragmentary gap, Postoperative range of movements, Development of complications and IOWA knee score at the end of 6 months in both the groups and comparing them. Data analysis was based on the statistical parameters like descriptive statistics, Chi-square/Contingency table analysis, T-test using SPSS for Windows version 27.0.0. Result: Loss of reduction was found to be numerically more in Modified TBW group. Comparing both groups statistically, Z-score is 1.222 and p-value is 0.222 (p>0.05) showing no significant difference in loss of reduction. Skin irritation due to hardware was found to be numerically more in Modified TBW group, Z-score is 2.085 and p-value is (p< 0.05) showing a highly significant difference. Implant loosening was found to be numerically more in Modified TBW group. Comparing both groups statistically, Z-score is 2.085 and p-value is 0.036 (p< 0.05) showing a highly significant difference. Therefore, though the amount of loss of reduction is similar in both the groups, complications like skin irritation and implant loosening is high in Modified TBW group, attributable to K-wire migration, which can be avoided to a certain extent, by bending the ends of K-wire over SS-wire after tensioning it in a figure of 8 and burying its ends in the soft tissue. Comparing each complication individually both groups incidence of superficial wound infection is the same in both the procedures. Summary: Cannulated screw tension band wiring technique combines the principle of lag screw and tension band providing both static and dynamic compression respectively, thus giving better fixation of transverse patellar fractures when compared to modified tension band wiring.