Fixation Of Distal Femoral Fractures Research Articles

Early weight-bearing following distal femur fracture fixation - a systematic review and meta-analysis.

The global standard of care for hip fracture surgery is early weight-bearing, but this has not extended to other lower extremity fractures in the elderly. Patients undergoing fixation of distal femur fractures are often prescribed weight-bearing restrictions, which may lead to deconditioning and other complications. The purpose of this study was to compare the outcomes and complication rates between patients permitted early versus restricted weight-bearing following distal femur fracture fixation. Medline, Embase, Cochrane and Web of Science databases were searched for English language articles up to 21 October 2023, identifying 366 studies for screening. Comparative studies evaluating patients undergoing distal femur fracture fixation with early or restricted weight-bearing were included. Native knee and periprosthetic fractures were included. Ten studies were included for analysis. Two studies provided Level II evidence, while the remaining eight studies provided Level III evidence. Cochrane risk of bias tools were utilized to assess study quality. Revision and complication rates were analyzed and reported as odds ratio. Sub-analysis was undertaken to address the heterogeneity in author definitions of weight-bearing. There was no statistically significant difference in the revision or complication rate between the two groups. Early weight-bearing following distal femur fracture fixation in a predominantly elderly population does not demonstrate an increased rate of revision or complications compared to restricted weight-bearing. However, there are limitations to the available literature, and the strength of the findings is insufficient to provide strong recommendations for all patients. Future studies should employ standardized definitions and avoid partial or time-based restrictions.

Single versus dual fixation of distal femur fractures: A retrospective cohort study at a level one trauma centre in New Zealand

Background The study compares single versus combination fixation of distal femur fractures. Method We retrospectively reviewed patients over 60 between January 2016 and December 2022. Union rate, ambulatory status and complication rate were primary outcomes. Secondary outcomes included quality of reduction, operative time and rate of blood transfusion. Results A total of 92 patients received single fixation, and 22 patients received combination fixation. There was no difference in rate or time of fracture union. Patients with dual fixation were allowed to weight bear on discharge significantly more than single fixation patients (50% vs. 18.9%, p = 0.003). Intramedullary nail fixation, as a single method or combined with lateral plating, was associated with earlier weight bearing. Immediate post-operative weight bearing significantly increased the likelihood of discharging to home or rehabilitation versus discharging to a transitional care facility ( p < 0.00001). There was no difference in the rate of blood transfusion, complication or mortality. Medial translation of the distal articular block was significantly lower with dual fixation (1.2% vs. 3.4%, p = 0.021). Operation time was longer with combination fixation (183 min vs. 134 min p < 0.001). Conclusion Combination fixation allows earlier weight bearing, at the cost of longer operation time.

Correction of a Golf Club Deformity of the Femur Using a Computer-Assisted Circular Ring Fixator: A Case Report.

The golf club deformity is the most notable malreduction that occurs after distal femur fracture fixation. This can lead to disruption of the patient's knee biomechanics, arthritis, and functional deterioration. There is a lack of consensus for optimal treatment of these malunions among the orthopaedic community. We present a technique that uses an osteotomy and ring external fixation with computer-assisted deformity correction and retrograde intramedullary nailing to secure correction. Our case shows a potential means to achieve a reliable and objective method of measuring, correcting, and securing the fixation of a golf club deformity.

Distal femoral fractures: periprosthetic fractures have four times more complications than non-periprosthetic fractures and cerclage should be avoided: retrospective analysis of 206 patients

BackgroundDistal femoral fractures account for less than 1% of all fractures. The therapy of choice is usually surgical stabilization. Despite advances in implant development over the past few years, complication rate remains comparatively high. The aim of this study is to analyze our results with plate fixation of distal femoral fractures with a focus on complication and fracture healing rates.MethodsIn this retrospective cohort study, patients (> 18 years) with distal femoral fractures treated at an urban level I trauma center between 2015 and 2022 were analyzed.ResultsIn total, 206 patients (167 female, 39 male) with an average age of 75 (SD 16) years were diagnosed with a fracture of the distal femur. One hundred fourteen of these patients were treated surgically by means of plate osteosynthesis. In 13 cases (11.41%), a revision procedure had to be performed. The indication for surgical revision was mechanical failure in eight cases (7.02%) and septic complication in five cases (4.39%). Periprosthetic fractures were more likely to cause complications overall (19.6% versus 4.76%) and further included all documented septic complications. The analysis of modifiable surgical factors in the context of plate osteosynthesis showed higher complication rates for cerclage in the fracture area compared with plate-only stabilizations (44.44% versus 22.22%).ConclusionsThe data show an increased amount of revisions and a significantly higher number of septic complications in the treatment of periprosthetic fractures of the distal femur compared with non-periprosthetic fractures. The detected combination of plates together with cerclage was associated with higher complication rates.Level of evidence Level III retrospective comparative study.

Medial augmentation of distal femur fractures using the contralateral distal femur locking plate: A technical note.

Lateral locking plates are commonly employed for the fixation of distal femur fractures. However, scenarios involving medial comminution, extremely distal fractures, periprosthetic fractures, or nonunion could necessitate medial augmentation. This study explores the possibility of using lateral distal femoral locking plate systems for medial fixation by employing the contralateral plate. This study presents a technical note on the application of lateral distal femur locking systems for medial augmentation in patients as indicated by current literature findings. Postoperative imaging modalities, including radiography and computed tomography (CT), were used to assess the plates' fit to the distal femur. Three cases following the specified technical note are presented. The various plate systems, all comprising distal femur locking systems, demonstrated adaptability to the medial femur anatomy as confirmed by intraoperative visualization and postoperative radiographs, including two-dimensional and three-dimensional CT scans. It has also been possible to achieve at least 3 independent fixation points regardless of the size of the medial condyle. Locking distal femoral plates can be a viable option for medial augmentation in indicated cases, achieving anatomical adaptation to the distal femur. This provides robust augmentation without the need for additional instruments beyond those used for the lateral cortex.

Staged Management for Distal Femur Fractures: Impacts on Reoperation, Stiffness, and Overall Outcomes.

To evaluate the outcomes of staged management with external fixation (ex-fix) prior to definitive fixation of distal femur fractures. Design: Retrospective cohort. Single Level I Trauma Center. Adults treated operatively between 2004 and 2019 for distal femur fractures (OTA/AO 33A/33C) were identified using Current Procedural Terminology codes. Excluded cases were those with screw only fixation, acute distal femur replacement, 33B fracture pattern, no radiographs available, or did not have 6-months of follow-up. Postoperative complication rates including surgical site infection [SSI], reoperation to promote bone healing, final knee arc of motion <90 degrees, heterotopic ossification formation, and reoperation for stiffness were compared between patients treated with ex-fix prior to definitive fixation and those not requiring ex-fix. A total of 407 patients were included with a mean follow-up of 27 months (median [IQR] of 12 [7,33] months), (range 6-192 months). Most patients were male (52%) with an average age of 48 [Range: 18-92] years. Ex-fix was utilized in 150 (37%) cases and 257 (63%) cases underwent primary definitive fixation. There was no difference in SSI rates (p=0.12), final knee arc of motion <90 degrees (p=0.51), and reoperation for stiffness (p=0.41) between the ex-fix and no ex-fix groups. The 150 patients requiring ex-fix spent an average of 4.2 days (SD 3.3) in the ex-fix before definitive fixation. These patients were further analyzed by comparing the duration of time spent in ex-fix, <4 days (n=82) and ≥4 days (n=68). Despite longer time spent in ex-fix prior to definitive fixation, there was again no significant difference in any of the complication and reoperation rates when comparing the two groups, including final knee arc of motion <90 degrees (p=0.63), reoperation for stiffness (p=1.00), and SSI (p=0.79). Ex-fix of distal femur fractures as a means of temporary stabilization prior to definitive ORIF does not increase the risk of complications such as SSI, final knee arc of motion <90 degrees, or reoperations for bone healing or stiffness when compared to single stage ORIF of distal femur fractures. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Far Cortical Locking Versus Standard Constructs for Locked Plate Fixation in the Treatment of Acute, Displaced Fractures of the Distal Femur

Background: Fixation of distal femoral fractures remains a challenge, and nonunions are common with standard constructs. Far cortical locking (FCL) constructs have been purported to lead to improved fracture-healing as compared with that achieved with traditional locking bridge plates. We sought to test this hypothesis in a comparative effectiveness clinical trial. Methods: This randomized trial was performed across 16 centers and included adult patients with an AO/OTA type 33A or 33C distal femoral fracture that was suitable for bridging fixation. We excluded patients with periprosthetic fractures. Participants were randomly assigned to either FCL fixation or standard locking plate fixation. The primary outcome was a hierarchical composite of radiographic and clinical fracture-healing at 3 months after fixation. We estimated between-group differences with use of the win ratio approach. Secondary outcomes included radiographic healing, clinical fracture-healing, complications, reoperations, and health-related quality of life (Short Form-36 Health Survey Version 2 [SF-36] Physical Component Summary and Mental Component Summary scores) at 3, 6, and 12 months after fixation. Results: We randomly assigned 193 patients to treatment with either FCL screws (96 patients) or standard screws (97 patients). The study population had a mean age of 63.4 years, consisted predominantly of women (68%), and was well-balanced between AO/OTA 33A and 33C fractures. Based on 4,355 pairwise comparisons, the calculated win ratio was 1.18 (95% confidence interval [CI], 0.77 to 1.79; p = 0.45), indicating that patients assigned to FCL screws had better outcomes in 51% of the comparisons. Radiographic healing did not differ significantly between the groups (odds ratio, 1.36; 95% CI, 0.69 to 2.72; p = 0.38), nor did Function IndeX for Trauma (FIX-IT) scores (p = 0.41). There were no significant differences between the groups in terms of SF-36 Physical Component Summary scores at 3 months or in the change in scores at 12 months after fixation. Conclusions: In this multicenter randomized trial of adult patients with an AO/OTA type 33A or 33C distal femoral fracture, similar clinical and radiographic healing outcomes were observed in the FCL and standard fixation groups. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Current Concepts in Management of Distal Femur Fractures

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.

The effect of coronal plane angulation on patient reported outcome measures of operatively treated distal femur fractures: A multi-center prospective evaluation

ObjectivesThe goal of this trial was to determine whether coronal plane angulation affects functional and clinical outcomes after the fixation of distal femur fractures. DesignMulticenter, randomized controlled trial Setting20 academic trauma centers Patients/Participants156 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. InterventionLateral locked plating or retrograde intramedullary nailing Main outcome measurementsRadiographic alignment, functional scoring including SMFA, Bother Index, and EQ-5D. Clinical scoring of walking ability, need for ambulatory support and ability to manage stairs. ResultsAt 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. ConclusionsValgus 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.

Titanium versus stainless steel alloy bridge plates for distal femur fractures: Does callus form earlier with titanium?

Distal femur fractures account for 3-6% of all femur fractures. Internal fixation of most distal femur fractures with an anatomic lateral locking plate should permit some motion at the metaphyseal portion of the fracture when secondary bone healing is planned by the operating surgeon. While several studies have been performed evaluating union rates for distal femur fractures with stainless steel and titanium plates, the timing of callus formation between stainless steel and titanium implants used as bridge plates for distal femur fractures (AO/OTA 33-A and -C) has been investigated to a lesser extent. We hypothesize that callus will be visualized earlier with post-operative radiographs with titanium versus stainless steel bridge plates. We retrospectively reviewed a consecutive cohort of patients over 18 years of age with acute AO/OTA 33-A and 33-C fracture patterns treated with an isolated stainless steel or titanium lateral bridge plate within 4 weeks of injury by a single fellowship-trained orthopedic trauma surgeon from 2011 to 2020 at one academic Level 1 trauma center. An independent, fellowship-trained orthopedic trauma attending surgeon reviewed anterior-posterior (AP) and lateral radiographs from every available post-operative clinic visit and graded them using the Modified Radiographic Score for Tibia (mRUST). Twenty-five subjects were included in the study with 10 with stainless steel and 15 with titanium plates. There were no significant differences in demographics between both groups, including age, sex, BMI, injury classification, open versus closed, mechanism, and laterality. Statistically significant increased mRUST scores, indicating increased callus formation, were seen on 12-week radiographs (8.4 vs. 11.9, p = 0.02) when titanium bridge plates were used. There were no statistically significant differences in mRUST scores at 6 or 24-weeks, but scores in the titanium group were higher in at every timepoint. In conclusion, we observed greater callus formation at 12 weeks after internal fixation of 33-A and 33-C distal femur fractures treated with titanium locked lateral distal femoral bridge plates compared to stainless steel plates. Our data suggest that titanium metallurgy may have quicker callus formation compared to stainless steel if an isolated, lateral locked bridge plate is chosen for distal femur fracture fixation.

Far cortical locking constructs for fixation of distal femur fractures in an Asian population: A prospective observational study

BackgroundThe stiffness of locked plates suppresses healing process, prompting the introduction of far cortical locking to address this issue. This study aimed to demonstrate the clinical efficacy of far cortical locking constructs in treating distal femoral fractures in an Asian population. MethodsThis multicenter prospective observational study was conducted at four university hospitals between February 2018 and February 2021. Demographic data, the presence of metaphyseal comminution, and surgical fixation details were recorded. Clinical outcomes, including single-leg standing, EQ-5D, and EQ-VAS scores, and radiologic outcomes, including the RUST score of each cortex, were evaluated and compared according to the presence of metaphyseal comminution. ResultsThere were 37 patients (14 men and 23 women) with a mean age of 67.3 ± 11.8 years. Twenty-two patients had metaphyseal comminution (59%), and 15 presented simple fractures in metaphyseal areas. Four patients (13%) could stand on one leg > 10s at 6 weeks, and 24 patients (92%) at 1 year. EQ-5D increased from 0.022 ± 0.388 to 0.692 ± 0.347, and the mean EQ-VAS 51.1 ± 13.1 to 74.1 ± 24.1 between discharge (n = 37) and post-operative 1 year (n = 33), respectively. RUST score presented increment for time, from 6.2 ± 1.8 at 6 week to 11.6 ± 1.1 at 1 year. Radiological healing demonstrated rapid increase from week 6 (16/28, 43%) to month 3 (27/31, 87%), with no obvious increase was observed in 6 months (23/26, 89%) or 12 months (25/28, 89%). Simple metaphyseal fractures presented significantly higher RUST scores at 6 weeks and 3 months, but there was no difference in RUST scores at 6 months or 1 year according to metaphyseal comminution. ConclusionsPlate constructs with far cortical locking screws provided safe and effective fixation for distal femoral fractures, with consistent radiological and clinical results, regardless of metaphyseal comminution.

The effect of body weight on interfragmentary fracture strain in plate fixation of distal femur fractures: A finite element analysis

IntroductionDistal femur fractures are difficult to successfully treat due to high rates of nonunion. Obesity is an independent prognostic risk factor for nonunion. Advances in finite element analyses (FEAs) have allowed researchers to better understand the performance and behavior of constructs at the bone-implant interface under a variety of conditions. The purpose of this study is to determine the impact of body weight on fracture strain in a lateral locking plate construct for supracondylar femur fractures and whether additional construct rigidity is beneficial to optimize fracture strain in high body mass patients. HypothesisWe hypothesized that increased loads would produce a higher interfragmentary strain (IFS), which could be decreased by shortening the working length of the construct. Materials and methodsA 3D finite element analysis was performed on two separate femur models with a comminuted supracondylar distal femur fracture fixed with a lateral distal femoral locking plate in bridging mode with Ansys software. Axial forces were varied to recreate the effect of load from normal and high body mass patients. Working length and screw density of the construct were varied for each condition. Measurements of interfragmentary strain and shear motion (SM) were compared. ResultsDoubling the axial load from 70kg (control) to 140kg (high body mass) increased the interfragmentary strain by an average of 76% for the three working lengths (3.38%±1.67% to 4.37%±0.88% at the baseline working length (BWL), 1.42%±1.00% to 2.87%±2.02% at the intermediate working length (IWL) and 0.62%±0.22% to 1.22%±0.42% at the short working length (SWL)). On average, decreasing the working length in the 140kg load reduced the mean IFS to within 15% of the mean IFS of the 70kg load at the longer working length (2.87%±2.02% at IWL 140kg versus 3.38%±1.67% at BWL 70kg and 1.22%±0.45% SWL 140kg versus 1.42±1.00% IWL 70kg). DiscussionIncreased axial load increases interfragmentary strain in an AO/OTA 33A distal femur fracture fixed with a lateral distal femoral locking plate. Decreasing the working length of the fixation construct in the high body mass model decreased interfragmentary strain. Higher loading conditions reflective of high body mass patients should be considered in studies investigating optimization of fracture strain. Level of proofV; Finite Element Analysis (FEA).

Nail Plate Constructs are Associated with Decreased Rates of Reoperation in Complex Distal Femur Fractures.

To determine if nail plate constructs have lower rates of reoperation to promote bone healing than lateral locking plates in the treatment of distal femur fractures. Retrospective Cohort. Single Level 1 trauma centerPatients/Participants: 312 consecutive patients treated operatively for native distal femur fractures (OTA/AO 33A or 33C). Reduction and fixation of distal femur fractures with either a lateral locked plate (LLP) or a nail plus plate construct (NPC). reoperation to promote bone healing at any time after definitive fixation. 279 fractures were treated with LLP and were compared with and 33 fractures treated with NPC constructs. Patient demographics, injury severity score (ISS), and frequency utilization of each construct between different types of OTA/AO classified distal femur fractures were similar. The reoperation rate to promote bone healing was 18.7% (51/273) for LLPs, and 3% (1/33) for NPC constructs. There was no significant difference in surgical site infection (SSI) (p = 0.67). Utilization of NPC technique demonstrated a significant decrease in rates of reoperation to promote bone healing compared to LLP alone in the treatment of OTA/AO 33A and 33C distal femur fractures. Augmented fixation with NPCs should be considered to treat complex distal femur fractures as it is associated with lower rates of reoperation to promote bone healing in comparison to LLP. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Best of Both Worlds? Fixation of Distal Femur Fractures with the Nail-Plate Construct.

Distal femoral fractures are a significant injury sustained by low- and high-energy trauma. Common treatment practices are lateral locking plate or intramedullary nail fixation, with disadvantages including risk of non and malunion and limited post-operative weightbearing status. Combining both techniques as a nail-plate construct (NPC) theoretically achieves enhanced fixation to allow immediate weightbearing. The aim of this study is to examine radiographic union, malunion and patient-reported outcomes in distal femur NPC fixation. Single-center retrospective study including all patients >18 years who sustained distal femur fractures treated with NPC. Primary outcomes were radiographic union, malunion and patient reported outcome measures at minimum 1-year follow-up. Secondary outcome measures included post-operative mobility, length of stay and complications. Relevant variables of normality are reported as mean with standard deviation. Subgroup analysis of patients aged <65 and ≥65 years are provided. Sixteen patients were included in the study. Rate of radiographic union was 100%. There was no case of malunion. All patients were allowed to bear full weight immediately post-operatively. Mean length of stay was 9.50 days, with 37.5% of patients discharged directly home. The majority (85.7%) of patients returned to pre-injury mobility. Early post-operative complications occurred in three patients. Three patients returned to theater. The mean EQ-5D-5L index value was 0.713, with 71.4% describing no problems with self-care and 85.7% reporting no or slight problems with usual daily activities. The NPC provided stable fixation permitting full weightbearing post-operatively with no cases of non or malunion. Return to pre-injury mobility and activity are encouraging. Based on these results we support the use of nail-plate construct fixation in the management of distal femur fractures.

Bridge Plate Fixation of Distal Femur Fractures: Defining Deficient Radiographic Callus Formation and its Associations.

To determine whether deficient early callus formation can be defined objectively based on association with an eventual nonunion and specific patient, injury, and treatment factors. Final healing outcomes were documented for 160 distal femur fractures treated with locked bridge plate fixation. Radiographic callus was measured on postoperative radiographs until union or nonunion had been declared by the treating surgeon. Deficient callus was defined at 6 and 12 weeks based on associations with eventual nonunion via receiver operator characteristic analysis (ROC). A previously described computational model estimated fracture site motion based on the construct employed. Univariable and multivariable analyses then examined the association of patient, injury, and treatment factors with deficient callus formation. There were 26 nonunions. Medial callus area at 6 weeks < 24.8 mm2 was associated with nonunion (12 of 39, 30.8%) vs. (12 of 109, 11.0%), p = 0.010. This association strengthened at 12 weeks with medial callus area < 44.2 mm2 more closely associated with nonunion (13 of 28, 46.4%) vs (11 of 120, 9.2%), p < 0.001. Multivariable logistic regression analysis found limited initial longitudinal motion (OR 2.713 (1.12 to 6.60), p = 0.028)) and Charlson Comorbidity Index (1.362 (1.11 to 1.67), p = 0.003) were independently associated with deficient callus at 12 weeks. Open fracture, mechanism of injury, smoking, diabetes, plate material, bridge span, and shear were not significantly associated with deficient callus. Deficient callus at 6 and 12 weeks is associated with eventual nonunion and such assessments may aid future research into distal femur fracture healing. Deficient callus formation was independently associated with limited initial longitudinal fracture site motion derived through computational modeling of the surgical construct, but not more routinely discussed parameters such as plate material and bridge span. Given this, improved methods of in vivo assessment of fracture site motion are necessary to further our ability to optimize the mechanical environment for healing.

Biomechanical comparison of distal femoral fracture fixation: Polyaxial vs. uniaxial locking screws with different blocking screw configurations in retrograde femoral nailing

IntroductionClinical studies have indicated reduced reliance on blocking screws with the introduction of polyaxial locking nails, yet the biomechanical superiority of polyaxial locking over blocking screws remains unverified, specifically for distal dia-metaphyseal femur fractures. HypothesisWe hypothesized that the combination of multiaxial locking using three screws and parallel locking reinforced by two blocking screws would result in superior outcomes compared to utilizing only parallel locking with two screws and one blocking screw. Materials and methodsThird-generation custom-made femur models representing AO/OTA 32 A1.2 dia-metaphyseal comminuted oblique fractures were divided into four groups (n=10/group). Group A employed distal fixation with three 4.5-mm polyaxial screws. Group B used two parallel locking screws and two blocking screws, Group C used two parallel locking screws and one blocking screw, and Group D used only two parallel screws. Specimens underwent axial and torsional load testing to assess fatigue strength, ultimate strength, axial stiffness (N/mm), torsional stiffness (N/mm/deg), axial load to failure (N), torsional load to failure (N/mm), coronal and sagittal angulations, and fracture site collapse. ResultsGroup C exhibited statistically superior torsional stiffness compared to Groups B and D (p=0.039 and p=0.034, respectively). Axial load to failure was highest in Group B and lowest in Group D (p=0.032). Group C demonstrated the highest torsional strength, while Group B exhibited the lowest (p=0.006). Coronal displacement was greatest in Group B, while Group A showed the highest resistance (p=0.009). Group A demonstrated the greatest resistance to fracture site collapse, with the weakest specimens observed in Groups B and C (p=0.01). DiscussionThe performance of a single laterally positioned blocking screw is comparable to using two blocking screws. Medial positioning of a second blocking screw is unnecessary for stability enhancement. Multiaxial locking prevents fracture site collapse and coronal plane angulation more effectively than other methods. Multiaxial locking and/or parallel screws with a single laterally positioned blocking screw provide superior stiffness and stability for treating unstable dia-metaphyseal distal femoral fractures. Level of evidenceN/A.

Does the type of medial plate fixation matter for supplemental fixation of distal femur fractures manage with a lateral pre-contoured locked plate? A Biomechanical study.

Fixation of distal femur fractures with a lateral pre-contoured locking plate provides stable fixation and is the standard treatment in most cases, allowing early range of motion with a high rate of union. However, in situations, the stability achieved with the lateral plate alone may be insufficient, predisposing to fixation failure. The objective of the study was to compare, in synthetic bone models, the biomechanical behaviour of the fixation with a distal femur lateral pre-contoured locking plate solely and associated with a 3.5mm proximal humeral locking plate applied upside down or a 4.5mm helical locking compression plate on the medial side. A total of 15 solid synthetic left femur samples were used. A metaphysical defect at the level of the medial cortex was simulated. The samples were randomly distributed into three groups equally. All groups received a 4.5/5.0mm single lateral 9-hole distal femur lateral pre-contoured locking plate. Group 1 had no supplementary plate. Group 2 received a supplementary 6-hole 3.5mm proximal humeral locking plate and Group 3 received a supplementary 4.5/5.0mm helical 14-hole narrow locking compression plate. Both supplementary plate types used in groups 2 and 3 contributed to increase the apparent stiffness of the construct, but pairwise comparison showed statically significant difference only between group 1 and 3. No significant difference was observed between groups 2 and 3. Both supplementary plates might be considered for improving the fixation in distal femur fracture in selected cases.

Retrograde intramedullary nailing or locked plating for stabilisation of distal femoral fractures? A comparative study of 193 patients

PurposeThe aim of this study was to evaluate the results of distal femoral fracture fixation of two different methods, lateral locking plate (LP) or an Intra-medullary nail (IMN), in patients managed in our institution. More specifically, to assess: (a) if there was a difference in functional outcomes between the LP and IMN groups; (b) whether the rate of complications was different between the two groups.MethodsBetween January 2009 and December 2018 adult patients with distal femoral fractures managed in our unit with either LP or IMN for extra and intra-articular fractures were eligible to participate. Demographic details, fracture type, procedures performed, time to union, complications and functional scores (Oxford Knee Score) were recorded and analysed. The mean follow up was 4 years (12–120 months).ResultsOut of 193 patients who met the inclusion criteria, 93 received an IMN whereas 100 patients were treated with LP. Mean age was 64.2 (18–99) and 70.1 (18–100) for the IMN and LP groups respectively. Overall, the two groups had similar demographics and there was no significant difference in the type of fractures sustained (p > 0.05). The Oxford Knee Score was highest for patients fixed with LP, mean 37.3 (6–48, SD 7.3) versus 28.4 (3–48, SD 14.4), (p = < 0.02) compared to the IMN group. In terms of complications, the rate of non-union was higher in the LP group 8.6% versus 4% in those patients treated with an IMN, p value < 0.01.ConclusionWhile the rate of non-union was higher in the LP group and the functional results were superior in the plating group.

Supplemental fixation of distal femur fractures: a review of biomechanical and clinical evidence

Background: Fixation of distal femur fractures with lateral locking plates has relatively high rates of clinical failure. Supplemental fixation has shown promising results, and may reduce rates of fixation failure or nonunion. This review aimed to assess the biomechanical and clinical evidence regarding the use of supplemental fixation of distal femur fractures. Methods: PubMed, Embase, and Cochrane databases were searched for English language studies up to December 4, 2020, identifying 1,829 studies. Biomechanical studies that assessed fracture displacement, load/cycles to failure, or construct stiffness and clinical studies that assessed fixation failure or nonunion after supplemental fixation of distal femur fractures were included. Studies with sample size ≤5, ORIF with non-locking plates, periprosthetic distal femoral fractures, nonunions or revision surgeries were excluded. Results: Seventeen studies were included, of which 8 were biomechanical and 9 clinical. Overall, biomechanical studies demonstrated increased construct stability and load to failure with various supplemental fixation strategies. Clinical studies demonstrated more mixed outcomes for nonunion and fixation failure rate among the various techniques. Conclusions: Biomechanical studies have demonstrated potential benefits of these strategies, but there remains a dearth of high-quality evidence evaluating their effect on clinical outcomes. Prospective RCTs are necessary to address these issues and confirm the results in the existing literature. Level of Evidence: IID

Using a Traction Table for Fracture Reduction during Minimally Invasive Plate Osteosynthesis (MIPO) of Distal Femoral Fractures Provides Anatomical Alignment.

Fracture reduction and fixation of distal femur fractures are technically demanding. Postoperative malalignment is still commonly reported after minimally invasive plate osteosynthesis (MIPO). We evaluated the postoperative alignment after MIPO using a traction table with a dedicated femoral support. The study included 32 patients aged 65 years or older with distal femur fractures of all AO/OTA types 32 (c) and 33 (except 33 B3 and C3) and peri-implant fractures with stable implants. Internal fixation was achieved with MIPO using a bridge-plating construct. Bilateral computed tomography (CT) scans of the entire femur were performed postoperatively, and measurements of the uninjured contralateral side defined anatomical alignment. Due to incomplete CT scans or excessively distorted femoral anatomy, seven patients were excluded from analyses. Fracture reduction and fixation on the traction table provided excellent postoperative alignment. Only one of the 25 patients had a rotational malalignment of more than 15° (18°). The surgical setup for MIPO of distal femur fractures on a traction table with a dedicated femoral support facilitated reduction and fixation, resulting in a low rate of postoperative malalignment, despite a high rate of peri-implant fractures, and could be recommended for surgical treatment of distal femur fractures.