This study was approved by the Ethics Committee of Shenzhen People's Hospital at Jinan University. All volunteers gave informed consent prior to participating in the study.
Characteristics and application principles of the“H” joystick device
Locked intramedullary nailing for the treatment of femoral shaft fractures requires careful preoperative planning and the application of multiple techniques to achieve suitable fracture reduction [11–13]. We will describe the details of the device we designed and the method of application. Moreover, we have applied for a patient.
The theoretical basis of the design is the leverage principle, which is used to reduce fractures by applying pressure on the skin without injury [14]. The device in this report includes two parallel horizontal joysticks, one vertical main joystick and four assistant rods. Moreover, there are many specific spacing holes in two parallel horizontal joysticks and a groove structure in vertical main joystick. By pressing the main “H” joystick, and lateral displacement and angulation can be adjusted because of the lever principle. The distance between parallel horizontal joysticks and assistant rods can adjust to the fracture position and body mass index of different patients.
Another important consideration is the material used to construct the device. The material we chose is invisible to X-rays and works in high-temperature environments. It does not contain any bolts or other metal components. It has the features of high intensity and low density. Therefore, when medical personnel make X-ray examinations for fracture reduction, it does not affect the physician’s judgement of the reduction, thereby improving the efficiency of the reduction procedure, relieving patient pain and reducing patient X-ray exposure time. Finally, the device can be disinfected with high temperatures and used in a sterile environment.
The main operation steps are described as below:
1. Assemble the device. Connect the main joystick with the two parallel horizontal joysticks and four assistant rods, as shown in Fig. 1.
2. Place assembled joysticks on the fracture sites and adjust the lateral displacement or angulation to reduce the fracture.
3. When the fracture reduction is satisfactory by X-ray, insert the "Gold-finger" along the medullary canal, go through the fractured face smoothly, and then penetrate the guide wire. Another method is to insert the intramedullary nail from the opening directly and complete the operation, as shown in Fig. 2.
We can adopt different devices using methods according to different fracture types. This report will describe operation skills in detail for both simple and complex fractures.
If the fracture type is an up-and-down or lateral displacement, using parallel joysticks 10, the main joystick 20 and two assistant rods 30 can reduce the fracture. For example, assume that the femoral shaft fracture type of the patient is that broken bone 41 is downwards and broken bone 42 is upwards, as shown in Fig. 2. Insert the main joystick 20 into the two parallel horizontal joysticks’ homolateral first holes 111 and 121 successively. According to the length and diameter of the fracture site, choose the suitable groove 211 in the main joystick 20. After insuring that the second holes 112 and 122 in the parallel horizontal joysticks align at the groove 211 lengthways, insert the first assistant rod 31 and the second assistant rod 32 and fix all the parallel horizontal joysticks and assistant rods. Next, insert the assembled device into the fracture site and make the first parallel joystick 11 below the broken bone 41 and the second parallel joystick 12 below the broken bone 42. Under X-ray the physician holds the handle 21 and moves the main joystick 20 according to the relative position of the fracture. Because of the lever principle, the first parallel joystick 11 will support the broken bone 41 upwards and the second parallel joystick 12 will press the broken bone 42 downwards. Therefore, we can reduce the fracture of bones 41 and 42. Similarly, other unidirectional fractures can be reduced. It is notable that the entire operation is simple and time-saving and that only one operating physician is required to complete the reduction.
If the fracture type is simultaneously multi-directional and complex, physicians need to use two more assistant rods to complete the reduction. In this case, the femoral shaft fracture type in these patients is that broken bone 41 is oriented downwards and broken bone 42 is oriented upwards and rightwards. On the basis of the previous example, insert the third assistant rod 33 and the forth assistant rod 34 into the suitable holes in the parallel horizontal joysticks. The assistant rods 31 and 32 play a part in fixation and support. In this orientation, the third assistant rod 33 could press the broken bone 41 rightwards and the fourth assistant rod 34 could press the broken bone 42 leftwards. Therefore, physicians can use this device flexibly to adapt different situations.
We performed a retrospective analysis of the medical records of patients treated for all femoral shaft fractures between 1 February 2013 and 30 May 2016 at our institution. During this period, there were 51 femoral shaft fractures. Patients with open fractures, pathological fractures, metabolic bone disease or neuromuscular disorders were excluded from our analysis. We selected 16 patients who were treated with an “H” joystick as objects of study. We processed all 16 patients’ radiographs and medical data statistically, including age, height and weight, sex, side, mechanism injury type, fracture location and fracture type classified by AO (Arbeitsgemeinschaft für Osteosynthesefragen) system [15]. The study was performed according to the guidelines stated in the Declaration of Helsinki [16] and the study protocol was approved by the local ethics committee.
All 16 patients, including 11 male patients (68.8%) and 5 female patients (31.2%), had a unilateral femoral shaft fracture. The mean age of patients was 31.0 years old (ranged from 20 to 55 years old). The weight of patients was an average of 63.3 kg (range from 49 to 78 kg). There were 6 cases (37.5%) injured on the right and 10 cases (62.5%) injured on the left. The injury types include 7 cases (43.8%) of traffic accidents, 5 cases (31.2%) of falls and 4 cases (25%) of sports injuries. The fracture location was divided to the proximal area, the proximal area and the distal area, with 6 cases (37.5%), 8 cases (50%) and 2 cases (12.5%), respectively. There were 9 cases (56%) of AO fracture type A, five cases (31%) of AO fracture type B, and two cases (13%) of AO fracture type C. Moreover, there were 4 cases of simultaneous combined injury and 2 cases of anamnesis such as hypertension and diabetes. The details are shown in Table 1.
Table 1
No. | Age (yrs.) | Height (cm)/ Weight (kg) | Sex | Side | Mechanism injury type | Fracture location | Fracture type (AO) |
1 | 23 | 163/49 | F | L | Traffic accident | Mid 1/3 | A3 |
2 | 42 | 175/63 | M | L | Sports | Mid 1/3 | A2 |
3* | 38 | 155/54 | F | L | Traffic accident | Dis 1/3 | A2 |
4 | 20 | 178/67 | M | R | Traffic accident | Mid 1/3 | B3 |
5** | 40 | 154/45 | F | L | Sports | Proximal 1/3 | A3 |
6** | 55 | 180/78 | M | L | Traffic accident | Proximal 1/3 | C3 |
7 | 31 | 176/66 | M | R | Sports | Mid 1/3 | B1 |
8* | 28 | 165/62 | M | L | Fall | Mid 1/3 | A3 |
9 | 32 | 157/63 | F | R | Traffic accident | Proximal 1/3 | A3 |
10 | 34 | 177/78 | M | L | Fall | Mid 1/3 | C2 |
11 | 29 | 163/56 | M | R | Traffic accident | Proximal 1/3 | A1 |
12* | 28 | 175/77 | M | L | Traffic accident | Proximal 1/3 | B2 |
13 | 42 | 176/71 | M | L | Sports | Mid 1/3 | A3 |
14 | 36 | 162/52 | F | R | Fall | Proximal 1/3 | B1 |
15* | 25 | 169/63 | M | L | Fall | Dis 1/3 | A3 |
16 | 22 | 177/69 | M | R | Fall | Mid 1/3 | B2 |
(*): Patients suffering from anamnesis such as hypertension or diabetes. (**): Patients suffering from simultaneous combined injury such as skull fracture, pulmonary contusion or upper limb fracture. |