Functional and Radiological Outcomes of Distal Femur Fractures treated with Less Invasive Stabilization System versus Dynamic Condylar Screw

Introduction: Fractures in the distal femur are quite rare, comprising around 0.4% of all fractures and 3% of femoral fractures. Managing distal femur fractures has been a subject of debate, but recent developments favor indirect reduction and minimally invasive approaches. The objective is to find a harmonious equilibrium between the mechanical stability of the fractured segments and their biological viability. Given their elevated complication rate, achieving optimal restoration of functional anatomy and ensuring stable fixation is imperative for prompt recovery from distal femoral fractures. Comparison of less invasive stabilization system versus dynamic condylar screw fixation in treatment of distal femur fractures is subject of ongoing debate as to which one is better. Aims and Objectives: To compare the functional and radiological outcomes of distal femur fractures treated with less invasive stabilization system versus dynamic condylar screw fixation. Place and Duration of study: A randomized clinical trial was conducted in the Orthopedic Department of Sheikh Zayed Hospital, Lahore, from July 2, 2020, to January 1, 2021. Material and Methods: A randomized clinical trial was conducted at Sheikh Zayed Hospital in Lahore over a six-month duration. In total 104 patients who fulfilled the inclusion criteria were admitted to the Orthopedic Department via Emergency and OPD. Demographic data and medical histories were taken. The sample size consisted of 52 patients in each group, with random allocation to either the LISS (A) or DCS (B) groups determined by a lottery method. Follow-up appointments were scheduled for all patients at one month, three months, and six months post-surgery. Radiological outcome was evaluated at each follow-up visit while functional outcome assessed at sixth monthly follow up. (cid:3) Data analysis was performed using the SPSS: version 22, (cid:3) considering p (cid:148) 0.05 as significant. Results: Frequency of functional outcome was i.e. excellent (32.7%), good (14.4%), fair (2.9%) in group A and excellent (27.9%), good (31.7%), fair (7.7%) in group B (p-value>0.05). Mean fusion time was 18.67±3.04 in group A and 19.62±4.36 in group B (p-value>0.05). Conclusion: Our findings indicate no substantial distinction between the two groups. Using DCS or LISS, both methods yield favorable outcomes with negligible complications in the management of distal femoral fractures. Both systems effectively reduce soft tissue injury.


INTRODUCTION
The femur, recognized as the longest and most robust bone in the human body1 , is susceptible to distal femoral fractures, which specifically impact the lower 9-15 cm of the femur extending up to the articular surface of the knee2 .In Europe, distal fractures are reported to occur approximately 10, times less frequently than proximal femoral fractures, with an incidence rate of around 6% 3 .In younger individuals, high-energy trauma such as firearm incidents, road traffic accidents and sports injuries are common causes whereas distal femoral fractures in elderly patients often result from lowvelocity injuries like falls during walking 4 .Treating distal femur fractures poses challenges, as they are frequently comminuted, unstable, involve intraarticular extension, and are associated with significant soft tissue damage to the quadriceps mechanism and ligamentous disruption of the knee joint 5 .The management of distal femoral fractures can be carried via operative versus non operative approaches.Prior to 1970, non-operative regimen was the preferred choice for treatment due to the limited availability of modern implants and minimal understanding of advanced surgical techniques.Challenges associated with non-operative management include knee stiffness, mal-union, non-

INTRODUCTION
Globally, acute generalized peritonitis ranks among the top surgical emergencies 1 .It is more common in Third World nations.The prevalence of perforation is low (0.6% -4.9%) in developed nations but high (33% -63%) in West Africa 2 .554 persons were discovered to have peritonitis in a study that took place over three years in India 3 .Researchers in Pakistan have conducted studies with similar methods, with one study reporting 650 cases in a just 9 months 4 .Most cases of peritonitis are caused by a gastrointestinal perforation or anastomotic leak 5 .In the case of peritonitis, anaerobes and gramnegative organisms are mostly responsible for sepsis and morbidity due to the overactive inflammatory cascade brought on by the release of endotoxins 5 .Clinical evidence is used to identify peritonitis.Diagnosis can be achieved via upright plain x-ray of the abdomen, USG, or CT scan.This is often done through diagnostic laparoscopy nowadays 6 .Resuscitation, diagnosis, prompt exploration, treatment of the underlying cause, and extensive surgical peritoneal lavage have always been the cornerstones of peritonitis therapy regimens (IOPL) 7,8 .Regular IOPL is performed to lessen bacterial contamination and burden.Even though large volumes of normal saline are used in IOPL, the rates of sepsis, wound infection, and mortality remain alarmingly high.Another method union and patient confinement to bed.Conversely, operative management offers advantages such as the ability to address soft tissue concerns, enable early mobilization and facilitate relatively straightforward nursing care 6 .Since the late 1990s, the introduction of diverse implant systems including the dynamic condylar screw, retrograde femoral nail and the Less Invasive Stabilization System for the Distal Femur has contributed to enhanced treatment outcomes 7 .In comparison to standard plates, the LISS plate enables significantly greater load-bearing capacity due to angular stability provided by locking screws.As LISS allows for more elastic deformities, making it a swift and uncomplicated procedure with minimal additional soft-tissue disruption than conventional plating systems.On the other hand, the drawbacks of the Dynamic Condylar Screw (DCS) include that that insertion of the condylar lag screw necessitates the removal of substantial amount of bone via reaming, complicating revision surgery if needed as DCS lacks a locking mechanism, so it leads to inadequate fixation of osteoporotic bone 8 .A multicenter RCT by Canadian Orthopedic Trauma Society revealed that there was no statistically significant difference between the LISS and the DCS in terms of functional scores, union time and no fractures healed.Revisions and complications were more in the LISS group.There was one reoperation in the DCS group and seven in the DCS group 9 .Nonetheless, the comparative analysis between DCS and LISS remains a subject of debate and no such study was conducted previously in Pakistan, so rationale behind our study was to compare and assess the functional and radiological outcomes of LISS versus DCS in distal femur fractures in local setting to put an end to this debate.

MATERIAL AND METHODS
A randomized clinical trial was conducted in the Orthopedic Department of Sheikh Zayed Hospital, Lahore, from July 2, 2020, to January 1, 2021 after approval from Institutional Review Board vide order No: F.1-6/ M. Education / 1372 /2019.The study comprised a total of 104 patients selected through non-probability consecutive sampling, with 52 patients each assigned to the LISS group (Group A) and the DCS group (Group B).Inclusion criteria were, patients aged 18-70 years with closed fractures and open fractures upto grade 2B.Whereas exclusion criteria were fractures older than three weeks, fractures associated with neurovascular injury, and patients with ASA Grade IV or higher.Demographic data and injury history, including the time, mode, and side of injury, were collected.Patients were assessed for life-threatening conditions following the ATLS protocol, and initial resuscitation was performed.Initial radiographs, including antero posterior and lateral views were taken and skin traction was utilized on the affected limb.Informed written consent was obtained preoperatively after obtaining approval from the hospital's ethical committee.All patients underwent surgery on the next regular list.During LISS plating, a 5 cm incision was made from Gerdy tubercle in line with the femur.The LISS plate was applied beneath the Vastus Lateralis muscle, and after fracture reduction, the precontoured plate was fixed to the distal femur using large bone clamps.The condylar part of the plate was temporarily fixed with a K wire, and a 4.5mm cortical screw was applied through the jig proximal to the fracture in bicortical fashion, followed by the application of condylar locking screws.A K wire was inserted perpendicular to the lateral femoral condyle for DCS surgery at intersection of anterior and middle third on lateral aspect and 2 cm proximal to distal end of femur.An appropriate length lag screw was passed over the guide wire after proper triple reaming and tapping.Once the lag screw was in place, a side barrel plate of appropriate length was affixed.Follow-up appointments were scheduled for all patients at one month, three months, and six months post surgery.Radiological outcomes, including mean fusion time, were assessed at each visit, and functional outcomes were evaluated using the Wilde modification of the Neer knee scoring system after six months.Data analysis was performed using the SPSS: version 22. Non probability consecutive sampling technique and same expert surgical team operating upon all cases were helpful to address bias.Qualitative variables such as gender, ASA grade, side of fracture, mode of injury, and functional outcome were presented as frequency and percentage.Quantitative variables like age, duration of fracture, and fusion time were expressed as mean ± SD.The functional outcomes of both groups were compared using the chi-square test while student ttest was applied to statistically test the differences in mean fusion time between the two groups, considering p 0.05 as significant.

Fig1: Less Invasive Stabilization System fixation of distal Femur Fig2: Dynamic Condylar Screw Fixation of Distal Femur
Age distribution of the patients showed that out of 104 patients, 26.9 %(n=28) were in age group of 18-50 years and 23.

DISCUSSION
Fractures involving the distal femur encompass both the supracondylar and intercondylar regions.
Treatment objectives adhere to AO principles, underlining the significance of anatomic reduction of the articular surface and the restoration of limb length, alignment and rotation.Despite advancements in implant design, managing distal femur fractures remains challenging due to their often comminuted, intra-articular nature, compounded by the involvement of osteoporotic bone, making achieving stable fixation a formidable task.In the geriatric trauma population, prevalent co-morbidities may influence therapeutic options 10 .Distal femoral fractures account for 0.4% of all and 3% of femur fractures 11 .The literature recognizes a typical bimodal age distribution, wherein younger, predominantly male patients experience high-energy trauma, while older individuals, more often females, suffer injuries from low-energy events like falls from standing.The prevalence of osteoporosis adds to the complexities faced by the older population.The steadily aging demographic is expected to

Table - 1: Distribution of Functional Outcome Fusion time
1 %( n=24) were in age group of 51-70 years in group A and 16.3 %(n=17) were in age group of 18-50 years and 33.7 %( n=35) were in age group of 51-70 years in group B. Mean age was calculated as 47.94±16.44years in group A and 51.37±15.25 years in group B .In gender distribution of the patients, 32.7 %( n=34) were male whereas 17.3 %( n=18) were females in group A and that 29.8 %( n=31) were male whereas 20.2 %( n=21) were females in group B .None of the patients dropped out of the study.Frequency of functional outcome was noted as excellent (32.7%), good (14.4%),fair (2.9%) in group A and excellent (27.9%), good (31.7%),fair (7.7%) in group B .Mean fusion time was 18.67±3.04weeks in group A and 19.62±4.36weeks in group B.