Objective:To evaluate the clinical outcome of 3D printing titanium cage combined with Masquelet technology for the treatment of calcaneus infective defect.Methods:Data of 5 cases with chronic calcaneus infectivedefect treated with regional flap, 3D printing titanium cage combined with Masquelet technology with rib autograft from January 2017 to January 2019 were retrospectively analyzed. There were 3 males and 2 females, with an average age of 37 years old (range, 17-52 years). The mechanism of the five patients included two motor vehicle incidents, two high fall injuries and one rolling compaction. All patients were treated by two-stage procedures. First stage included debridement, polymethyl methacrylate (PMMA) filling and regional flap coverage. The soft tissue defect of the 5 cases included 10 cm×8 cm in 2 cases, 8 cm×7 cm, 8 cm×5 cm, and 5 cm×3 cm each in one case. Bone defect included 4 cm×3 cm×2 cm in two cases, 3 cm×3 cm× 2 cm in two cases and 3 cm×1 cm×1 cm in one case. Second stage was 3D printing titanium cage combined with masquelet technology of rib autograft. Time of bone union, morphology of calcaneus, position of implant, Maryland score and AOFAS hind foot score were recorded to evaluate the clinical outcome.Results:All five patients were followed up for an average time of 18.2 months (range, 12-30 months). Infection happened in one patient 2 months after first stage operation and successfully treated by debridement and PMMA replacement. Incision of the rest 4 cases all healed successfully. Germiculture of the five cases included Methicillin-resistant Staphylococcus aureus (MRSA) in three cases, Staphylococcus epidermidis in one case and Bacterium coli in one case. All five patients got calcaneus bone union after second stage operation. The average time for bone union was 4.32 (range, 3-8) month. Bone trabecular were observed in CT scan 13 (range, 10-22) month post-operation. Average Maryland score in 12 months post-operation was 92 (range, 86-98) and average AOFAS ankle hind foot score was 89.8 (range, 83-100).Conclusion:3D printing titanium cage and Masquelet technology maybe an effective treatment for calcaneus infective defect.

Objective:To explore the risk factors for complications related to internal fixation after Inter-Tan intramedullary nail fixation in the treatment of intertrochanteric fractures in elderly patients.Methods:A retrospective cohort study was conducted to analyze the clinical data of 314 elderly patients with intertrochanteric fractures admitted to the Seventh Medical Center of the Chinese PLA General Hospital from January 2016 to December 2020, including 100 males and 214 females, aged 60-98 years [(80.2±8.2)years]. All the patients underwent Inter-Tan intramedullary nail fixation. According to the 2018 AO/OTA classification, 103 patients were with stable fractures and 211 with unstable fractures. The patients were further divided into complication groups and non-complication groups according to the presence of the complications during the follow-up. Six patients (5.8%) with stable fractures had the complications including nonunion in 4 and cut-out in 2. Twenty-eight patients (13.3%) with unstable fractures developed the complications, including nonunion in 5, cut-out in 20, cut-through in 1, and broken nails in 2. With the internal fixation-related complications after surgery as dependent variables, and gender, age, complications [hypertension, coronary heart disease, arrhythmia, pulmonary infection, chronic obstructive pulmonary disease (COPD), renal insufficiency, diabetes], bone density, waiting time for surgery, anesthesia method, reduction method, reduction quality, tip-apex distance, head screw displacement and other influencing factors as independent variables, univariate and multivariate Logistic regression analyses were conducted on the patients with stable fractures and unstable fractures separately to screen the independent risk factors of internal fixation-related complications.Results:For the patients with stable fractures, the univariate analysis indicated significant differences in bone density and reduction quality between the complication group and non-complication group ( P<0.05 or 0.01); the multivariate Logistic regression analysis showed that bone density T value ≤-3.0 SD ( OR=33.17, 95% CI 2.40, 457.82, P<0.01) and poor reduction quality ( OR=71.38, 95% CI 3.58, 1 422.02, P<0.01) were significantly correlated with the incidence of the postoperative complications. For the patients with unstable fractures, the univariate analysis indicated significant differences in age, reduction quality, bone density, tip-apex distance, and screw displacement between the complication group and non-complication group ( P<0.05 or 0.01); the multivariate Logistic regression analysis showed that age >80 years ( OR=2.82, 95% CI 1.01, 7.93, P<0.05), bone density T value ≤-3.0 SD ( OR=6.10, 95% CI 2.06, 17.51, P<0.01), poor reduction quality ( OR=12.25, 95% CI 2.90, 51.79, P<0.01), tip-apex distance ≥25 mm ( OR=3.65, 95% CI 1.20, 11.08, P<0.05), and head screw displacement <4 mm ( OR=7.26, 95% CI 2.54, 20.81, P<0.01) were significantly correlated with the postoperative complications. Conclusion:For Inter-Tan intramedullary nail fixation of intertrochanteric fractures in elderly patients, low bone density and poor reduction quality are independent risk factors for the postoperative complications in patients with stable intertrochanteric fractures; old age, low bone density, poor reduction quality, tip-apex distance, and head screw displacement are independent risk factors for the postoperative complications in patients with unstable fractures.

Objective:To compare the failure risks between restricted and unrestricted cephalomedullary nail sliding during InterTAN intramedullary nail fixation for intertrochanteric fractures in the elderly patients.Methods:A retrospective study was conducted to analyze the data of 192 elderly patients with intertrochanteric fracture who had been admitted to Department of Orthopaedics, The Seventh Medical Center, General Hospital of the People's Liberation Army from January 2021 to December 2022. The patients were divided into 2 groups based on whether the set screws were tightened or not during surgery. In the observation group of 78 cases, there were 31 males and 47 females with an age of (80.2±7.7) years, and 23 cases of type 31-A1 and 55 cases of type 31-A2 by the AO classification. Their set screws were not tightened during surgery to allow the cephalomedullary nail sliding. In the control group of 114 cases, there were 40 males and 74 females with an age of (81.6±7.8) years, and 42 cases of type 31-A1 and 72 cases of type 31-A2. Their set screws were tightened during surgery to restrict the cephalomedullary nail sliding. The incidence of postoperative fixation complications and sliding distances of the cephalomedullary nail within 1 year after surgery were compared between the 2 groups in the total fractures and in the stable and unstable fractures as well.Results:There was no statistically significant difference in the preoperative general data between the 2 groups of patients, indicating comparability ( P>0.05). The incidence of fixation complications within 1 year after surgery was 5.1% (4/78) for the observation group and 12.3% (14/114) for the control group, showing no statistically significant difference between the 2 groups ( P>0.05). The sliding distance of the cephalomedullary nail in the observation group [7.05 (6.00, 8.25) mm] was significantly larger than that in the control group [5.65 (3.55, 7.00) mm] ( P<0.05). For stable fractures, the incidence of fixation complications within 1 year after surgery was 7.1% (2/28) for the observation group and 7.0% (3/43) for the control group, showing no statistically significant difference ( P>0.05), and the sliding distance of the cephalomedullary nail in the observation group [6.00 (5.25, 7.00) mm] was significantly greater than that in the control group [3.05 (2.00, 5.00) mm] ( P<0.05). For unstable fractures, the incidence of fixation complications within 1 year after surgery for the observation group patients [4.0% (2/50)] was significantly lower than that for the control group patients [15.5% (11/71)], and the sliding distance of the cephalomedullary nail in the observation group [8.00 (6.70, 10.00) mm] was significantly greater than that in the control group [6.00 (4.87, 7.57) mm] ( P<0.05). Conclusions:In the InterTAN intramedullary nail fixation for intertrochanteric fractures in the elderly patients, tightening of set screws is crucial because it not only increases the stability but also limits compression at the fracture site. It is recommended not to tighten the set screws for unstable fractures, but further observation is needed before it can be determined whether the set screws should be tightened or not for stable fractures.