General Information
Regression analysis of patients with the tibia's infectious bone defect was treated in our hospital and cooperative units from January 2013 to January 2018, mainly including closed tibial fracture internal fixation, tibial open fracture, and chronic tibial osteomyelitis. According to the eligibility criteria, all patients were followed up and evaluated(Table 1). All patients included in the study signed an informed consent form, and the ethics committee approved our review of our hospital and our partner unit.
Table 1 Eligibility criteria of the study.
A total of 48 patients meeting the criteria were included in the study. The patients included in the study were divided into two groups: an experimental group and a control group. The experimental group (VCS implantation group) 27 cases: 23 males and four females; age 25–73 years old, average (48.81 ± 11.07) years old; The course of the disease was 1 to 86 months, with an average of (21.00 ± 16.08) months; 17 cases of the infectious bone defect after internal fixation of closed tibial fractures, 8 cases of contagious bone defect of open tibial fractures, 2 cases of chronic blood-borne osteomyelitis of tibia with the bone defect; The length of the bone defect after debridement was 3.5 cm to 14 cm, with an average of (7.52 ± 2.34) cm. Control group (no VCS implantation group) 21 cases: 18 males and three females; age 28–66 years old, average (50.29 ± 9.99) years old; The course of the disease was 1 to 38 months, with an average of (17.67 ± 10.54) months; 14 cases of an infectious bone defect after internal fixation of closed tibial fractures, 6 cases of contagious bone defect of open tibial fractures, 1 case of tibia chronic hematogenous osteomyelitis with the bone defect; The length of the bone defect after debridement was 3.5cm-13.5cm, with an average of (7.68 ± 2.58)cm. There was no significant difference in gender, age, cause classification of infectious bone defect, disease course, and length of the bone defect after debridement between the two groups (P > 0.05) (Table 2).
Table 2 Comparison of basic preoperative data between EG and CG groups
Group
|
Cases
(n)
|
Gender
(n)
|
Age
(years)
|
Etiology classification of
infectious bone defect
(n)
|
Course of
Disease
(month)
|
Bone defect length
(cm)
|
|
|
Male/Female
|
X̄±s
|
(Internal fixation of fractures/
open fractures/osteomyelitis)
|
X̄±s
|
X̄±s
|
CG
|
21
|
23/4
|
50.29±9.99
|
14/6/1
|
17.67±10.54
|
7.68±2.58
|
x2/t value
|
-
|
0.000
|
0.476
|
0.162
|
0.822
|
0.221
|
P value
|
-
|
1.000
|
0.636
|
0.922
|
0.416
|
0.826
|
Experment group(EG),Control group(CG)
Surgical Methods
In the supine position, the patient uses general anesthesia or combined spinal-epidural anesthesia, covers the infected wound and surgical field with a protective film, and fixes it with a unilateral rail-type external frame so that the outer structure is parallel to the mechanical axis of the tibia. The screw is perpendicular to the mechanical axis of the tibia. The upper and lower metaphysis were fixed with three screw screws, and the bone segment to be moved was fixed with two screw screws. If the remaining metaphyseal bone segment is too short or the osteoporosis is too heavy to fix three screw nails. After fixation is lacking, the stability adds 1 to 3 at a particular crossing angle between the metaphysis and the above screw nails. A threaded pin is fixed together with a single-sided rail-type outer frame with a combined external fixing frame to increase stability. Continuous drilling osteotomy was used to perform single-plane osteotomy under the metaphysis periosteum to prepare for bone removal. The metaphyseal incision was sutured and wrapped with a sterile dressing. Then remove the infected bone, dead bone, and hardened bone, and trim the bone stump into parallel cross-sections as much as possible. Finally, the lesions were washed alternately with hydrogen peroxide and normal saline and washed with diluted iodophor.
For internal fixation cases, we first remove the inner focus, thoroughly debride the wound, re-sterilize, drape, and finally perform external fixation and metaphyseal osteotomy.
In the experimental group, the powdered medical CS and vancomycin hydrochloride were mixed at a mass ratio of 10:1, stirred with the matching diluent, and applied to the mold when it was in a paste state. After it has solidified into a bead shape, it is implanted into the bone defect area after debridement. The bone defect area of the control group was left open.
Postoperative Treatment
According to preoperative bacterial culture results, sensitive antibiotics were administered intravenously for one week after surgery. Instruct patients to exercise limb function, significantly to strengthen nearby joints' exercise and increase the affected limb's axial stress stimulation through pedaling actions. Bone removal was started one week after surgery, with 1/6mm each time, 4–6 times a day. After the operation, take pictures for review monthly and adjust the bone migration speed according to the growth of new bone and the patient's tolerance. After the bone stump meets, slow down the bone moving speed, and continue to slowly move the bone for about two weeks (about 20–30 times in total) to keep the docking site in a state of compression. After the bone stump meeting, the patient was instructed to start walking with crutches and part of the weight-bearing. After the docking site is clinically healed, the affected limb's weight-bearing is gradually increased until the weight is fully loaded. When the patient walks with full weight, and there is no pain in the docking site and new bone, gradually loosen the external fixation frame or reduce the external fixation screws. According to the imaging findings, the outer fixation frame was removed after about three months.
In the following cases, the docking site is cleaned up, and the autogenous iliac bone is grafted: there is skin incarceration between the bone stumps; the bone stumps are conical or axially offset, and the bone contact area is small; After the bone stump reunion, compression fixation was taken for two months to observe the docking site without signs of healing.
Observation Index
Observe whether the docking site has skin incarceration after surgery, whether the docking site heals naturally and the healing time, whether there is a recurrence of infection or re-fracture, external fixation index, etc. According to Paley's infectious nonunion evaluation criteria [10], observe bony results and functional results.
Statistical analysis
The SPSS 22.0 statistical software was used for statistical analysis of the two groups of observation indicators. The measurement data is expressed as±. Comparing age, disease course, bone defect length, and external fixation index between groups was performed using two independent samples t test. Counting data is expressed in frequency. Comparing the two groups of patients' gender, etiology classification, Skin incarceration rate on docking site, docking site natural healing rate, bony results, and functional results were compared by χ2 test. The test level α value was taken as two-sided 0.05, P < 0.05 considered the difference statistically significant.