Outcome of Fracture Distal Femur Treated with Intramedullary Interlocking Nailing

Objective: To evaluate the functional and radiological outcome of the distal femur fracture treated with a retrograde locking nail. Methods: This is a descriptive study conducted at the Orthopedic department Dibba Hospital Fujairah, United Arab Emirates for one-year duration from March 2019 to March 2020. All patients who met the inclusion criteria were treated with femoral retrograde nailing technique. The postoperative functional score was assessed according to Schatzker and Lambert criteria, which were rated excellent, good, and poor. Radiological union was assessed by X-rays. Results: There were 103 patients with a mean age of 35.20 ± 10.66 (range, 20 to 50 years). There were 78 men (75.72%) and 25 women (24.27%). Most of the fractures (68.9%, n = 71) were Original Research Article Silro et al.; JPRI, 33(40B): 285-291, 2021; Article no.JPRI.72214 286 caused by car accidents. Fracture of the right side occurred in 70 (67.96%) patients, and the left side fracture in 33 (32.03%) patients. Excellent results were obtained in 75 (72.81%) patients and good results were obtained in 28 patients (28.20%). The nonunion has been documented in one patient. Conclusion: Excellent and good functional and radiological results were obtained in patients with distal femur treated with retrograde locking nails. For some distal femoral fractures, we recommend the use of a retrograde locking nail.


INTRODUCTION
Fractures of the distal femur are often the result of high-energy injuries, such as car accidents in young patients, and low-energy injuries, such as a simple fall in older osteoporotic patients and women [1,2]. Although it accounts for 6% of common femoral fractures, inappropriate treatment can result in knee stiffness and osteoarthritis [3,4]. Distal femur fractures are usually treated surgically, and there are several treatment options for these fractures, but the ultimate goal is operative knee internal structure including alignment, fusion, weight bearing and early range of motion [5]. Closed intramedullary implants not only take into account the soft tissue sheath and the periosteum, but can achieve this goal without increasing the risk of infection and prolonged immobilization [6]. A retrogradelocking nail is associated with rapid healing, early union and fewer complications. This implant is preferred over plates and screws due to the load distribution during application, minimal soft tissue dissection and periosteal stripping, greater likelihood of union and earlier mobilization of the patient [7,8]. Treatment options for distal femur fractures in our department include traction treatment, locking plate, interlocking nails and Ilizarov [9]. We performed this descriptive study to determine the functional and radiological outcome of a distal femur fracture treated with a retrograde locking nail. The results of this study will help us establish standard guidelines for the management of distal femur fractures.

METHODS
This is a descriptive study conducted at the Orthopedic department Dibba Hospital Fujairah, United Arab Emirates for one-year duration from March 2019 to March 2020. All adult patients of both sexes with distal femoral fractures were admitted to an emergency department or OPD within a week were included in this study. Open fractures, pathological fractures and multiple injuries requiring surgical intervention in other parts of the body were excluded from the study. All patients were initially assessed and treated for any life-threatening conditions. A complete interview and physical examination were performed in all patients. Skin traction or a long slab was used upon delivery. The limb was xrayed in both views and the fracture was classified according to the AO classification system (A1 in 38, A2 in 30 A3 in 21, and C1 in 14). In the case of fragmented fractures, 3D computed tomography scanning was recommended. All operations were performed on radiolucent operating table with scope controls under general or spinal anesthesia. All patients were administered a second-generation cephalosporin (cefuroxime) during preoperative induction. The operation was carried out by a senior consultant with at least 5 years of experience after a postgraduation. All procedures were performed in a uniform and standard manner. The femoral condyles were opened through a central incision with a bent knee. An appropriate entry point was made with an image intensifier, 5-6 cm incision was made between the lower pole of the patella and the tuberositas tibia, and the arthrotomy was performed by longitudinally splitting the tendon, and a guide wire was passed, keeping reduction and alignment. Sufficient nail length (Short nails (25 cm) were used in all patients except 1 patient having mid distal shaft fracture 32 cm tibia nail was inserted retrogradely) and maximum diameter nail was seated firmly and locked (In 62 fractures, 1 screw was used for proximal locking, whereas in 41 fractures two screws were used for proximal locking) at both ends.
Physiotherapy was started on the first day after surgery to induce an early range of motion in the knee. Patients were initially called for follow-up at 2, 4, and 6 weeks, then monthly for a year. At each visit, patients were clinically assessed for range of motion and weight tolerance. X-rays were taken to view the bone union.
Radiological recovery was assessed using AP and lateral view x-rays. Categorical variables (such as gender, fracture side, fracture type) were presented as frequency and percentage, while quantitative variables (such as age) were presented as mean and standard deviation. Important variables such as age were stratified to control effect modifiers, and a Chi-square test was used to see statistical significance. A p value of <0.05 was considered significant.

Excellent n=103
Good Functional outcome

DISCUSSION
The patterns of distal femur fractures are so diverse that no single treatment option can be recommended for all of these fractures. However, closed intramedullary nailing has fewer advantages in terms of complications compared to early mobilization and other treatment options [11]. The demographic profile of our study participants was almost the same as that reported in previous studies. In our study, excellent results were obtained in 75 (72.81%) patients according to Schatzker and Lambert criteria, and good results in 28 (28.20%) patients. Kim et al [12][13][14][15][16] had excellent or good results in 84% (26 of 31 patients), but the sample size was 31 [13,14]. They also reported 3 nonconsolidated femurs in their series. They consider a retrograde nail to be a good option. In the treatment of distal femoral fractures, care should be taken only in overly comminuted fractures and fractures around the knee joints. 20 patients were treated with retrograde nailing and had excellent results in 50% of patients, good results in 20% and moderate results in 5%. However, the performance evaluation tool used was the Neer scoring system. The youngest patients in their series, like ours, achieved good results [13]. However, they reported multiple complications such as pulmonary embolism in 2 patients, shortening of the femur in 3 patients, knee stiffness in 2 patients, and delayed union in 3 patients. No connection in their series were also reported. A study also stated that 9% are not united in their work. In our study, we obtained a higher rate of union with minimal complications, and similar results were obtained in previous studies [14][15]. Retrograde nailing is a closed treatment option without breaking the fracture hematoma and leads to early callus formation. This observation was confirmed by Henderson in his comparative study with nailing [16]. He found excessive early periosteal callus formation in the nail group compared to the plating group. Recommendation of titanium nails was also made for the treatment of distal femoral fractures in elderly patients, especially distal femoral fractures. Comparison was made between retrograde intramedullary nailing with traditional open reduction and found a much greater need for posterior bone grafting and the incidence of defective union in the ORIF group than in the nailing group. There was also a higher rate of infection and non-union in the ORIF group, but this was not statistically significant [17][18]

CONCLUSION
Excellent and good functional and radiological results have been obtained in patients with the distal femur treated with retrograde locking nails one patient faced delayed union but later on he was healed completely. We recommend retrograde locking nails as the first choice for certain distal femur fractures. With this treatment option, patients walk and move earlier and return to work and social life faster than with other treatments for similar fractures.