The Clinical Outcome of the Reduction of the Patellar Inferior Pole Fracture with Wire Cerclage Through A Generated Bone hole, in Combination with Patellar Concentrator: A Retrospective Comparative Study
Authors: Chen Rong , Cao Hong , Sun Zhibo , Jiang Liangbo , Li Xiangwei , Zhao Lin , Liu Xinghui 
Published: December 2021

Abstract
Objective: The patellar inferior pole fracture is typically comminuted. Hence, achieving firm fixation and early activity is highly challenging. In this article, we employed the method of wire cerclage through a generated bone hole to reduce the fracture. Our objective was to compare the clinical efficacy of patellar concentrator alone with a combination of cerclage and patellar concentrator in the treatment of patellar inferior pole fracture.Methods: We conducted a retrospective review of patients with patellar inferior pole fractures, who underwent patellar concentrator fixation only (the control group) or cerclage combined with patellar concentrator fixation (the experimental group), performed by a single surgeon, between July 2015 and October 2019. Our analysis included surgical indexes like7 aspects (fracture gap after operation, operation time, intra-operative blood loss,intra-operative number of C-arm fluoroscopies conducted, Insall-Salvati ratio calculated immediately after operation, initial range of motion on the 7th day after operation, and fracture healing time), as well as the Bostman score and complications recorded on 1-, 3-, 6-, and 12-month follow up post operation.Results:A total of 94 patients with patellar inferior pole fracture and a minimum 1-year followup were recruited. Following operation, the control group had 33(71.74%) patients with a fracture gap of 0-2 mm and 13(28.26%)patients with a fracture gapgreater than 2 mm(P=0.002). Conversely,the experimental grouphad46(95.83%)patients with a fracture gap of 0-2 mm and 2(4.17%) patients with a fracture gapgreater than 2 mm(P=0.002). Compared to the control group, the experimental group did not experience enhanced operation time or intra-operative blood loss (P=0.811, P=0.823). The Insall-Salvati ratio and initial range of motion in the experimental group were larger than the control group (P=0.037, P=0.000). Alternately, the number of intra-operative C-arm fluoroscopies conductedand fracture healing time of the experimental group were considerably less than the control group (P=0.003,P=0.000).Moreover, at 1-, 3-, 6-, and 12-month follow ups after operation, the Bostman scores of the experimental group were remarkably higher than the control group (P< 0.05).At 12 months post operation, 23 cases (50%) were classified as excellent, 22 cases (47.83%) were good, and 1 case (2.17%) was poor in the control group(P=0.005). In the meantime, in the experimental group, 38 cases (79.17%) were deemed as excellent and 10 cases (20.83%) were good (P=0.005).Lastly, complications were detected in 3 cases (6.52%;1 case of internal fixation loss,2 cases of hematoma) within the control group, and in 1 case(2.08%; marginal wound necrosis) within the experimental group. There was no wound infection, implant discomfort, or broken fixation in eithergroup.Conclusion: Managingthe patellar inferior pole fracture with wire cerclage through a generated bone hole is both simple and effective. Moreover, an additional step of patellar concentrator fixation facilitates early functional exercise, with satisfactory clinical outcome.