Effect Of Surgical Treatment Of Ulnar Styloid Process Fracture On The Postoperative Outcome Of Type C Distal Radius Fracture

Objective:The risk factors of ulnar styloid process fracture and the influence of ulnar styloid process fracture on the postoperative outcome of distal radius fracture were analyzed by studying the preoperative data and postoperative follow-up data of patients with type C distal radius fracture.Methods: Data were collected from patients with type C distal radius fractures who underwent surgery using certain inclusion and exclusion criteria.Patients were divided between group 1 and group 2 on the basis of whether they combined ulnar styloid process fracture or not.Group 1 was divided into Hauck type I group(group A)and Hauck type II group(group B)according to Hauck classification.Then groups A and B were divided into surgery group(groups A1 and B1)and non-surgery group(groups A2 and B2)according to whether ulnar styloid process fractures were surgically treated or not.The general data and preoperative imaging parameters(palmar tilt,ulnar inclination,and radial height)of patients in groups 1 and 2 were compared followed by logistic regression analysis to analyze the factors associated with the occurrence of ulnar styloid process fractures.The gender,age,BMI,preoperative imaging data and ulnar styloid process fracture surgery rate were compared and analyzed between the groups A and B.12 to 24 months is the period that all patients in groups A and B need to be followed up and the imaging data(palmar tilt,ulnar inclination and radial height difference at 1 day and 1 year after operation as the loss values of each parameter)at 1 day,1 month,3 months and 1 year since the surgery.The Cooney score,DASH score data at follow-up were obtained.The loss values of each imaging parameter and the data of the two functional scores were compared within groups A and B,respectively,the influence of ulnar styloid fracture on the postoperative outcome of distal radial fractureResults:1.In all,94 patients were included,including 48 patients in group 1 and 46 patients in group 2.No differences in age,gender and BMI were showed between groups 1 and 2.Preoperative imaging parameters of patients in group 1 were lower than those in group 2(P=0.001,P=0.025,P=0.021).Logistic regression analysis showed that palmar tilt,and radial height values were negatively correlated with the incidence of ulnar styloid process fractures in patients with distal radius(OR = 1.109,95% CI = 1.038 – 1.184,P = 0.002;OR = 1.635,95% CI = 1.101 – 2.428,P = 0.015),and there was no correlation between ulnar inclination and ulnar styloid process fracture occurrence(OR = 1.193,95% CI = 0.978 – 1.456,P = 0.082).2.There were a total of 23 patients in group A and 25 patients in group B.No prominent variations in mean age,gender,BMI,palmar tilt,ulnar inclination,and radial height between group A and B(P >0.05)however,the USF surgery rate in group A was lower than that in group B(P <0.05).3.There were 8 patients in group A1 and 14 patients in group A2.Except for 1 patient who was lost to follow-up,the other patients were successfully followed up.The follow-up time of all patients was 8-14 months,with an average of 13.4 ± 2.8 months.After surgery,patients in both groups had different degrees of palmar tilt,ulnar inclination,and radial height loss.There was no prominent variation in palmar tilt,ulnar inclination,and radial height loss values between groups A1 and A2(P = 0.426,P = 0.675,P = 0.792).No variation were showed in the excellent and good rate of Cooney scoring between group A1 and group A2(group A1 was 87.5%,group A2 was 78.6%,P = 0.793);the mean DASH score was 34.75 ± 6.14 in group A1 and 33.64 ± 6.85 in group B2,no variation were showed within group A(P = 0.702).One patient in A1 had Kirschner wire loosening due to premature removal of the cast and weight-bearing,which was dismantled within 1 month after operation.None had incision infection,deep infection,bedsore or flexor tendon injury caused by internal fixation during postoperative hospital stay in both groups.During follow-up,no nonunion,delayed union,or traumatic arthritis were also found.4.There were 14 patients in group B1 and 8 patients in group B2 in group B.All patients were followed up except 3 patients who were lost to follow-up.All patients in group B were followed up for 7-14 months,with an average of 12.9 ± 3.3 months.Patients in groups B1 and B2 also showed loss of palmar tilt,ulnar inclination,and radial height after surgery.Significant variations were showed in postoperative palmar tilt and radial height loss between groups B1 and B2(P = 0.021,P = 0.029),with more loss in group B2 than B1,and no different could be found in ulnar inclination loss between group B1 and B2(P = 0.542).The excellent and good rate of Cooney score in group B1 was higher than that in group B2(92.9% in group B1,50% in group B2,P=0.034).;the mean DASH score was 36.71 ± 4.61 in group B1 and 34.13 ± 4.05 in group B2,no variation were showed between group B1 and group B2(P = 0.189).None had complications for instance flexor tendon injury,infection,nonunion,or arthritis.Conclusion: Loss of palmar tilt radial height are risk factors of ulnar styloid process fractures in distal radius fractures.Whether Hauck type I ulnar styloid process fracture is operated or not has no effect on the postoperative outcome of distal radius fracture,surgical treatment of Hauck type II ulnar styloid process fracture is conducive to wrist joint function recovery after distal radius fracture operation.