Study design
The inclusion criteria were patients aged over 14 years old, diagnosed as open distal tibial fractures, AO classification as type 43-A, no vascular or nerve injuries, final implant option is intramedullary nailing or plate with screws, complete clinical demographic and radiographic data, the exclusion criteria were pathological fractures, polytrauma patients and incomplete clinical demographic and radiographic data.
A single-center, case control, retrospective study was conducted at Lower Limb Surgery Ward of Traumatic Orthopedic Department,Xi’an Honghui Hospital from January 2016 to January 2019. All eligible data was collected and reviewed based on the system included; age, gender, mechanism of injury, history of smoke and alcohol, comorbidity disease, AO classification, Gustilo classification, mangled extremity severity score(MESS), days before operation, final treatment option, surgical duration, intraoperative bleeding loss, length of stay, complications, Johner-Wruhs criteria[7], total cost within 1 year after surgery (including hospitalization expenses and postoperative rehabilitation or follow-up expenses).
All the patients were divided into two groups based on the final treatment options: Group IMN and Group LCP. Cost data for each case within 1 year after surgery were analyzed for the cost-effectiveness ratio (CER)and incremental cost-effectiveness ratio (ICER) of IMN versus LCP. In our study we used the CER as the average cost/ the excellent and good rate of Johner-Wruhs criteria*100, meaning the average cost for every 1% of excellent and good rate in each group. The ICER was the difference of average cost between the two groups/ the difference of excellent and good rate between the two groups*100, meaning how much did it cost more for each 1% increasing of excellent and good rate in Group LCP compared with Group IMN.
Surgical procedure
Debridement surgery was performed after accomplishing the preoperative estimating by debriding all contaminated and nonviable tissue. Irrigation volume depended on the severity of fracture with 3L for type I, 6L for type II and 9L for type III fractures [8]. External fixation was performed as a temporizing fixation and vacuum sealing drainage was used for temporary coverage between further debridement or until flap coverage. Second debridement surgery might be in progress within 24 to 48 hours. Whenever the soft tissue viability or adequacy of debridement was questionable, further debridement would be necessary to prevent infection before performing the final internal fixation [9]. The final fixation options were variable depending on the soft tissue injury, the pattern of fracture and the experience of orthopedic surgeon. When intramedullary nailing was applied for the final option (Fig.1), it was critical to differentiate and correct the rotational deformity and angular malalignment during surgery [10]. However, fractures associated with metaphysis fracture and soft tissue condition permitted the alternative option, we might refer to minimally invasive plates and screws as the final fixation (Fig.2).
Statistical analysis
SPSS24.0 was used for all data analysis and P<0.05 selected as the threshold for statistical significant. A Pearson test for normality was conducted for all continuous data, and the continuous data with the normal distribution was described in the form of mean ± standard deviation whereas the categorical data was described in number of cases (percentage). The Student’s t-test was conducted for continuous variables with the normal distribution and the Mann-Whitney U-test for those not with the normal distribution. As for the categorical variables, the χ2 test was performed.
Outcomes
We enrolled 49 consecutive patients treated by intramedullary nail (Group IMN,28 cases) or plate (Group LCP,21 cases) as the final treatment option. The excellent and good rate were 82.1% and 85.7% respectively based on the Johner-Wruhs criteria.
Demographic result
The demographic data of the patients are shown in Table1, and there was no statistically significant difference between the two groups in terms of gender, age, history of smoke and alcohol, comorbidity disease, injury mechanism, AO classification, Gustilo classification, mangled extremity severity score (MESS). The comorbidity disease of the patients mainly included hypertension, diabetes and coronary heart disease.
Perioperative result
The perioperative period data including injury to surgery interval, times of surgical debridement, final treatment option, total surgical duration, total length of hospital stay, the onset of complications including infection(surgical site, lung and urinary system), deep vein thrombosis, bedsore, compartment syndrome, delayed union and nonunion are shown in Table 2. The total surgical duration and total intraoperative bleeding loss were significant lower in Group IMN than in Group LCP, meanwhile no statistically significant difference of other variables was found between the two groups.
Economic analysis
The mean total cost within 1 year after surgery of Group IMN was (126435.90±39093.98) CNY and that of Group LCP was (147834.60±56821.12) CNY, the cost of Group IMN was significantly lower than that of Group LCP. The principal outcome calculated was the incremental cost-effectiveness ratio (ICER), which is the ratio of the difference in costs to the difference in excellent and good rate of Johner-Wruhs criteria between the two groups in our study. The mean total cost for every 1% of excellent and good rate was 1540.02 CNY in the Group IMN, which was favored more than the Group LCP of 1725.02 CNY. Each 1% increasing of excellent and good rate cost 5944.08 CNY more in Group LCP compared with Group IMN.