”Floating knee” injury is a serious injury with increasing incidence, which is characterized by serious injury, many complications and high mortality rate, and is very difficult to treat; improper treatment often causes serious complications. According to V.P. Bansal’s typology, 18 cases of type III floating knee injury were admitted to our department from August 2002 to September 2008, and 18 cases were treated surgically. The results were satisfactory and are reported below.
1. Clinical data
1.1 General data of this group of 18 cases, 13 male, 5 female, age 21-53 years old, average 33 years old, 9 cases of car accident injury, 4 cases of fall injury, 5 cases of smash injury, including 6 cases of combined cranio-cerebral injury, 3 cases of rib fracture, 2 cases of radius fracture. Lu Yanting, Department of Orthopedics, Puyang People’s Hospital
1.2 Imaging examination
We routinely took front and lateral radiographs of the knee joint, femur and tibia-fibula, and pelvic plain radiographs for high-energy injuries, and performed spiral CT to clarify the fracture morphology and the extent of involvement and reconstruction after the condition stabilized.
1.3 Preoperative preparation
Patients with open fractures are cleared in the first stage with stable vital signs, and fracture fixation treatment is performed after the swelling subsides or skin conditions improve in the second stage, usually in about 10 days, and in principle, not more than 4 weeks.
1.4 Surgical operation
Under general anesthesia or epidural anesthesia in the horizontal position, both lower extremities are routinely disinfected and toweled, a lateral and anterior tibial incision of the lower femur is performed, the fracture is exposed by incision, the fracture of the condyle is fixed first, followed by fixation of the bone cadre, and the knee joint surface is repositioned to achieve anatomical repositioning as far as possible, while repeated fixation operations are not advocated intraoperatively, because the support of the bone is easily destroyed.
Bone grafting was routinely performed to support the joint site and the bone compression part, contrast the contralateral side, maintain the lower limb force line relationship, and then perform external fixation frame with joint to fix the proximal femur fracture at one end and the distal tibia at the other end, and fix the middle at the tibial tuberosity, fix the external fixation frame to adjust the patient’s negative gravity line, maintain the knee joint flexion 15 degrees, put the drainage tube, postoperative film review, 2 weeks to adjust the knee joint flexion 15-30 degrees The knee should be adjusted to 30 to 50 degrees in 3 to 4 weeks, and the angle should be adjusted according to the patient’s condition, and the external fixation frame should be removed in 4 to 6 weeks. Functional exercise.
2. Results
All 18 patients were followed up after surgery, with a follow-up time of 4 months to 5 years, with an average of 3 years. The efficacy of the treatment of floating knee injury was evaluated with reference to Karlström and Olerud criteria [3], in which 3 cases were excellent, 8 cases were good, 5 cases were moderate and 2 cases were poor. There were 1cm~3cm limb shortening, 3 cases of bone non-healing, 1 case of deformity and 1 case of infection.
3.Experience
In 1975, Blake and McBryde first referred to ipsilateral femoral and tibial fractures as floating knees in their article entitled ‘Floating Knees’, and in 1984 Winquist made the meaning of floating knees more clear: floating knees refer to fractures of the ipsilateral femoral and tibial trunks or adjacent metaphyses resulting in a chain-like shape of the entire knee segment. B.H. Chang divided this injury into three types according to anatomical location: bicondylar, diaphyseal, and mixed, which is simple to remember but has shortcomings.
V.P. Bansal (1984) divided this injury into three types. Type I: stem type that is ipsilateral femoral stem and tibial stem fracture at the same time; Type II: epiphyseal type that is one bone is a stem fracture and the other bone is an epiphyseal fracture; Type III: condylar type that is ipsilateral femoral condyle and tibial condyle fracture at the same time. All 18 cases in this group were classified according to this type.
The injury of floating knee is mostly caused by high energy, heavy trauma, and mostly accompanied by other parts or organ injuries, with high mortality and few cases of early surgery. In treating such patients, the primary treatment is to ensure stable vital signs and adequate perfusion and oxygen supply to all vital organs; and then how to reduce the deformity, non-union, and dysfunction of floating knee injury fractures and reduce complications such as fat embolism (FES) and infection.
Most periprosthetic fractures involve the articular surface and are intra-articular fractures with clear indications for surgery. Those with severe skin and soft tissue injuries should wait for local soft tissue conditions to improve before surgery. In femoral supracondylar or and intercondylar comminuted fractures, most cancellous bones have compression defects and are prone to internal and external knee deformities, and if there is limb shortening, the principle of AO should be followed when resetting and bone grafting if necessary.
Internal or external fixation of the fracture through surgery not only has a significantly higher excellent rate than conservative treatment, but also early surgery can reduce the incidence of fat embolism and respiratory dysfunction, and even reduce the impact of amputation on the patient’s spirit, psychology and discomfort of the prosthesis. In the above 18 patients, we gave a return visit for surgery and prognosis;
For the fracture, especially the comminuted fracture of the lower femoral epicondyle and the comminuted fracture of the upper tibiofibula, the external fixation frame with articulation + internal fixation is good for restoring the strength of the fracture fixation and adjusting the joint mobility, maintaining the normal limb mechanics curve, reducing the early occurrence of knee valgus deformity, fracture misalignment, compression, etc., especially the knee deformity caused by excessive activities of the patient in the early stage.
By adjusting the external fixation frame, the force line of the limb can be restored and the extension and flexion angle of the knee joint can be adjusted. In practice, it has been confirmed that prolonged external fixation has not brought negative effects to the patient. For the intraoperative operation, we suggest that the intercondylar should be reset first, temporary fixation with a Kirschner pin, and the condylar plate should be fixed with a tension nail first, then reset, and the force line should be adjusted according to the contralateral limb to prevent excessive anterior tilting of the anterior condylar joint surface, and to explore the joint for ligament damage, which is also important for the postoperative recovery.