Recent studies report the overall incidence of distal femur fractures as 8.7/100,000/year. This incidence is expected to rise with high energy motor vehicle collisions and elderly osteoporotic fractures in native and prosthetic knees keep increasing. These fractures are more common in males in the younger age spectrum while females predominate for elderly osteoporotic fractures. Surgical treatment is recommended for these fractures to maintain articular congruity, enable early joint motion and assisted ambulation. Over the last two decades, development of minimally invasive and quadriceps sparing surgical approaches, availability of angle stable implants have helped achieve predictable healing and early return to function in these patients. Currently, laterally positioned locked plate is the implant of choice across all fracture patterns. Retrograde with capital implantation of intramedullary nails with provision for multiplanar distal locking is preferred for extra-articular and partial articular fractures. Even with these advancements, nonunion after distal femur fracture fixation can be as high as 19%. Further recent research has helped us understand the biomechanical limitations and healing problems with lateral locked plate fixation and intramedullary nails. This has lead to development of more robust constructs such as nail-plate and double plate constructs aiming for improved construct strength and to minimise failures. Early results with these combination constructs have shown promise in high risk situations such as fractures with extensive metaphyseal fragmentation, osteoporosis and periprosthetic fractures. These constructs however, run the risk of being over stiff and can inhibit healing if not kept balanced. The ideal stiffness that is needed for fracture healing is not clearly known and current research in this domain has lead to the development of smart implants which are expected to evolve and may help improve clinical results in future.

BACKGROUND: Distal femur fractures remain treatment challenges with a considerable postoperative non-union rate. Concern remains that surgery may compromise osseous vascularity. This study aimed to determine effects of retrograde femoral intramedullary nailing (RFIN) on distal femur vascularity, and the locations of the middle genicular artery terminal branches in relation to the standard RFIN entry point.
METHODS: Five lower limb cadaveric pairs were obtained (ten specimens). Experimental limbs were randomly assigned, and contralateral limbs served as controls. An 11 mm femoral nail was implanted in experimental specimens. Controls only underwent a medial parapatellar incision with capsulotomy. Quantitative pre- and post-contrast-MRI was performed to assess arterial contributions to distal femur regions. Osseous vascularity was further evaluated with contrast-CT imaging. Next, specimens were injected with latex medium, and dissection was performed to assess extraosseous vasculature.
RESULTS: No statistically significant differences were found with quantitative-MRI in experimental and control groups for the entire distal femur or individual regions. The experimental group demonstrated a small mean decrease of 1.4% in distal femur arterial contributions. CT and anatomic dissection confirmed maintenance of middle genicular artery terminal branches. On average, 3.3 (±1.3) terminal branches entered along the posterior intercondylar notch. A mean distance of 15.2 mm (±6.9 mm) was found between the posterior RFIN entry point and these terminal branches.
CONCLUSIONS: RFIN did not significantly alter arterial contributions to the distal femur or disrupt the middle genicular artery terminal branches. However, care must be taken to ensure nail entry point accuracy given proximity of the entry point to terminal branches.

UNASSIGNED: Securing stable internal fixation for fractures in osteoporotic intra-articular distal femur proves to be a demanding task due to thin cortices, a wide medullary canal, diminished bone stock, and fracture comminution. No singular therapeutic approach has successfully tackled all facets of this injury. Consequently, we now introduce a pioneering fixation method in our report, aiming to offer a holistic solution to the intricate challenges associated with this scenario.
UNASSIGNED: A 60-year-old female presented with an intra-articular distal femur fracture, and underwent a combination fixation of distal femur plate and intramedullary interlocking nailing. The patient was rehabilitated with active knee range of motion on post-operative day 7 and has now attained full knee range of motion.
UNASSIGNED: The utilization of anatomical plates with locking mechanisms, in tandem with intramedullary interlocking nailing, holds promise for the secure stabilization and fixation of osteoporotic distal femur fractures, potentially leading to an expedited recovery process.

BACKGROUND: Fractures of the distal femoral third are an important cause of morbidity and mortality, and their treatment is currently controversial.
OBJECTIVE: To compare the results between minimally invasive techniques versus exposure of the fracture site. Secondly, to evaluate the relationship between demographic factors, mechanism of injury and surgical delay with patient prognosis.
METHODS: Retrospective cohort study carried out between 2015 and 2021 in a tertiary hospital. Data collection was performed by reviewing medical histories, measuring demographic and hospital parameters and definitive treatment strategy. One year of follow-up was completed in all patients, assessing the occurrence of surgical complications and mortality. A stratified analysis of the variables of interest was performed among patients over 65 years of age.
RESULTS: 128 fractures were recorded, with definitive osteosynthesis being performed in 117. Patients who underwent minimally invasive techniques required a shorter hospital stay (9 [7-12] vs. 12 [8.75-16] days) (p=0.007), with no differences in mortality or complications during follow-up. In those over 65 years of age, opening the fracture site was associated with an increased risk of infection compared to minimally invasive techniques (33.3% vs. 2%) (p=0.507). All the deceased were patients over 65 years of age (33.7% at one year). Surgical delay longer than 48h increased mortality by 10% among those older than 65 years (p=0.3). High-energy trauma had a higher proportion of pseudarthrosis (27.6% vs. 6.1%) (p=0.011).
CONCLUSIONS: Minimally invasive techniques decreased hospital stay but not complications or long-term mortality.
METHODS: IIb.

UNASSIGNED: Distal femur fractures (DFFs) following total knee arthroplasty (TKA) in older patients often require prolonged non-weight-bearing, thereby decreasing their activities of daily living (ADL) and increasing mortality. This report clarifies early weight-bearing safety and utility by using double-plate fixation on medial and lateral sides (LM180 double-plate fixation) for DFFs following TKA.
UNASSIGNED: Three cases of Su Type III periprosthetic, interprosthetic, and interimplant DFFs following TKA, where bone stock was limited, were treated with LM180 double-plate fixation using locking plates through medial and lateral incisions on the distal femur. In interprosthetic and interimplant DFF cases, the proximal section was secured by overlapping the lateral plate +/- medial plate with the proximal femur stem of the intramedullary nail by using monocortical screws and cerclage wires. Early postoperative partial weight-bearing was recommended, and full weight-bearing was allowed 4-5 weeks postoperation. All cases regained independent walking without hardware failure. Average ADL scores, namely, Barthel index (BI) and functional independence measure (FIM), were recovered to 85/100 and 114.7/126, respectively, approaching near-normal values.
UNASSIGNED: LM180 double-plate fixation for DFFs such as Su Type III periprosthetic, Vancouver type C interprosthetic, and interimplant DFFs following TKA with limited bone stock can be used to achieve early weight-bearing without fixation failure and help maintain ADL.

BACKGROUND: This study experimentally validated a computationally optimized screw number and screw distribution far cortical locking distal femur fracture plate and compared the results to traditional implants.
METHODS: 24 artificial femurs were osteotomized with a 10 mm fracture gap 60 mm proximal to the intercondylar notch. Three fixation constructs were used. (i) Standard locking plates secured with three far cortical locking screws inserted according to a previously optimized distribution in the femur shaft (n = 8). (ii) Standard locking plates secured with four standard locking screws inserted in alternating plate holes in the femur shaft (n = 8). (iii) Retrograde intramedullary nail secured proximally with one anterior-posterior screw and distally with two oblique screws (n = 8). Axial hip forces (700 and 2800 N) were applied while measuring axial interfragmentary motion, shear interfragmentary motion, and overall stiffness.
RESULTS: Experimental far cortical locking plate results compared well to published computational findings. Far cortical locking femurs contained the highest axial motion within the potential ideal range of 0.2-1 mm and a sheer-to-axial motion ratio < 1.6 at toe-touch weight-bearing (700 N). At full weight-bearing (2800 N), Standard locking-plated femurs had the only axial motion within 0.2-1 mm but had an excess shear-to-axial motion ratio. Nail-implanted femurs underperformed at both forces.
CONCLUSIONS: For toe-touch weight-bearing, the far cortical locking construct provided optimal biomechanics to allow moderate motion, which has been suggested to encourage early callus formation. Conversely, at full weight-bearing, the standard locking construct offered the biomechanical advantage on fracture motion.

OBJECTIVE: The goal of this trial was to determine whether coronal plane angulation affects functional and clinical outcomes after the fixation of distal femur fractures.
METHODS: Multicenter, randomized controlled trial SETTING: 20 academic trauma centers PATIENTS/PARTICIPANTS: 156 patients with distal femur fractures were enrolled. 123 patients were followed 12 months. There was clinical outcome data available for 105 patients at 3 months, 95 patients at 6 months and 81 patients at one year.
METHODS: Lateral locked plating or retrograde intramedullary nailing MAIN OUTCOME MEASUREMENTS: Radiographic alignment, functional scoring including SMFA, Bother Index, and EQ-5D. Clinical scoring of walking ability, need for ambulatory support and ability to manage stairs.
RESULTS: At 3 months, there was no difference between groups (varus, neutral or valgus) with respect to any of the clinical functional outcome scores measured. At 6 months, compared to those with neutral alignment, patients with varus angulation had a worse Stair Climbing score (4.33 vs. 2.91, p = 0.05). At 12 months, the average patient with neutral or valgus alignment needed less ambulatory support than the average patient in varus. Walking distance ability was no different between the groups at any time point. With respect to the validated patient-based outcome scores, we found no statistical difference in in the SMFA, Bother, or EQ-5D between patients with valgus or varus mal-alignment and those with neutral alignment at any time point (p > 0.05). Regardless of coronal angulation, the SMFA trended towards lower (improved) scores over time, while EQ-5D scores for patients with varus angulation did not improve over time.
CONCLUSIONS: Valgus angulation and neutral angulation may be better tolerated in terms of clinical outcomes like stair climbing and need for ambulatory support than varus angulation, though patient reported outcome measures like the SMFA, Bother Index and EQ-5D show no statistical significance. Most patients with distal femur fractures tend to improve during the first year after injury but many remain significantly affected at 12 months post injury.

OBJECTIVE: This cohort study aimed to describe the functional outcomes, complications, and mortality of patients over 65 with acute distal femur fractures treated with open reduction and internal fixation (ORIF) or distal femoral replacement (DFR).
METHODS: We retrospectively analyzed all patients older than 65, operated consecutively for a distal femur fracture treated with ORIF or DFR. We included 75 patients (9 33A, 5 33B, and 61 33C AO/OTA fractures), 55 treated with ORIF, and 20 with DFR. We used Parker\'s mobility index (PMI) to assess functional outcomes at 1, 3, and 12 months and study closure. We analyzed complications, reoperations, and mortality at 30 days, one year, and at the end of the study.
RESULTS: The PMI was significantly higher in the DFR group at months 1 (p = 0.023) and 3 (p = 0.032). We found no significant differences between cohorts at one year and the end of follow-up. Postoperative complications were significantly more frequent in the ORIF group (38.10% vs. 10%, p = 0.022). Reoperations were similar in both cohorts (p = 0.98). Mortality at one month was 4% and 20% at one year, and at the end of follow-up, there were no significant differences between groups.
CONCLUSIONS: The outcomes of this study suggest that DFR offers a faster functional recovery with lower complication rates than those treated with ORIF. Additionally, both options have similar reoperation and mortality rates. Appropriately designed studies are needed to define the best treatment strategy for this type of patient.

OBJECTIVE: Distal femur fractures remain a significant cause of morbidity and mortality for elderly patients. There is a lack of large population studies investigating short-term outcomes after distal femur c in elderly patients. The purpose of this study is to assess the incidence of and risk factors for various short-term outcomes after distal femur open reduction internal fixation (ORIF) in the geriatric population.
METHODS: The American College of Surgeons\' National Surgical Quality Improvement Program (NSQIP) database was used to identify all primary distal femur ORIF cases in patients 60+ years old between January 1, 2015 and December 31, 2020 using Current Procedural Terminology (CPT) codes 27511, 27513, and 27514. Demographic, medical, and surgical variables were extracted for all patients. Propensity score matching was used to match cases in the two age groups based on various demographic and medical comorbidity variables. Several 30-day outcome measures were compared between the 60-79-year-old and 80+-year-old groups both before and after matching. Subsequent multivariate logistic regression was used to identify independent risk factors for 30-day outcome measures in the matched cohort.
RESULTS: A total of 2913 patients were included in the final cohort: 1711 patients in the 60-79-year-old group and 1202 patients in the 80+-year-old group. Most patients were female (n = 2385; 81.9%). Prior to matching, the older group had a higher incidence of 30-day mortality (1.9% vs. 6.2%), readmission (3.7% vs. 9.7%, p = 0.024), and non-home discharge (74.3% vs. 89.5%, p < 0.001). Additionally, the older group had a higher rate of blood loss requiring transfusion (30.9% vs. 42.3%, p < 0.001) and medical complications (10.4% vs. 16.4%, p < 0.001), including myocardial infarction (0.7% vs. 2.7%, p < 0.001), pneumonia (2.7% vs. 4.6%, p = 0.008), and urinary tract infection (4.1% vs. 6.1%, p = 0.0188). After matching, the older group consistently had a higher incidence of mortality, non-home-discharge, blood loss requiring transfusion, and myocardial infarction. Various independent risk factors were identified for 30-day morbidity and mortality, including American Society of Anesthesiologists (ASA) classification, body mass index (BMI) status, operative duration, and certain medical comorbidities.
CONCLUSIONS: Geriatric patients undergoing distal femur ORIF are at significant risk for 30-day morbidity and mortality. After matching, octogenarians and older patients specifically are at increased risk for mortality, non-home discharge, and surgical complications compared to patients aged 60-79 years old. Multiple factors, such as BMI status, ASA classification, operative time, and certain medical comorbidities, are independently associated with poor 30-day outcomes.

UNASSIGNED: Through meta-analysis, this study aims to comprehensively evaluate the efficacy of single-plating and double-plating in the treatment of comminuted fractures of the distal femur.
UNASSIGNED: Computer searches of PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), VIP, and Wanfang digital journals were performed, and the timeframe for the searches was from the establishment of each database to July 2023 for each of the databases. Meta-analysis was performed using RevMan 5.4 software provided by the Cochrane Library, and the review process was registered in the PROSPERO database.
UNASSIGNED: A total of ten studies were included for statistical analysis. One randomised controlled study and nine retrospective cohort studies with a total of 563 patients were included. The double-plate group was superior to the single-plate group in terms of knee mobility at 6 months postoperatively, overall postoperative complications, and the rate of healing of knee deformity. However, it increased the operation time and intraoperative bleeding, and the difference between the two groups was statistically significant (P < 0.05). There was no significant difference between the two groups in terms of excellent knee function rate, fracture healing time, plate fracture, postoperative infection, delayed fracture healing, and non-union (P ≥ 0.05).
UNASSIGNED: Double plate fixation for comminuted fractures of the distal femur can improve knee mobility at 6 months postoperatively, reduce overall postoperative complications, and decrease the incidence of malunion healing. However, it increases operative time and bleeding. Randomised studies are needed to provide strong evidence in the future.