Healing, nonunion, and re-operation after internal fixation of diaphyseal and distal femoral fractures: a systematic review and meta-analysis

Clinical differences between periprosthetic and native distal femur fractures: a comparative observational study

INTRODUCTION

The incidence of periprosthetic distal femur fractures (PDFF) is increasing as the number of total knee replacements becomes more common. This study compared the demographics, fracture characteristics, treatment, and outcomes of periprosthetic versus native distal femur fractures (NDFF).

MATERIALS AND METHODS

This was a retrospective cohort study of patients ≥ 18 who underwent surgical fixation of NDFF or PDFF from 2012 to 2020 at a level-1 trauma center. The main variables collected included demographics, AO/OTA fracture classification, fixation construct, concomitant fractures, polytrauma rates, bone density, and reduction quality. Primary outcomes were unexpected return to the operating room (UROR), hospital length of stay, and quality of reduction. T-tests, Fisher's exact tests, and multivariate analyses were used for statistical analysis.

RESULTS

209 patients were identified, including 70 PDFF and 139 NDFF. PDFF patients were elderly females (81%) with isolated (80%) and comminuted (85%) 33 A.3 (71%) fractures. NDFF patients included 53% females, were commonly middle-aged, and displayed comminuted (92%) 33 C.2 fractures. 48% of NDFF patients had concomitant fractures. Intramedullary nailing was the primary fixation for both groups, followed by nail-plate combination (37%) for PDFF and lateral locking plates (21%) for NDFF. NDFF patients experienced significantly longer hospital stays, higher UROR rates, and worse quality of reduction (p < 0.05). PDFF patients had a significantly greater prevalence of low bone density (p < 0.05).

CONCLUSION

PDFF occur as isolated injuries with significant metaphyseal comminution in elderly females with low bone quality. NDFF commonly occurs in younger patients with less metaphyseal comminution and concomitant fractures. Intramedullary nailing was the most common treatment for both groups, although preference for nail-plate combination fixation is increasing. NDFF type 33 C fractures are at greater risk of UROR.

Severity of Complications after Locking Plate Osteosynthesis in Distal Femur Fractures

Background: Locked plating for distal femur fractures is widely recommended and used. We systematically reviewed clinical studies assessing the benefits and harms of fracture fixation with locked plates in AO/OTA Type 32 and 33 femur fractures. Methods: A comprehensive literature search of PubMed, Embase, Cinahl, Web of Science, and the Cochrane Database was performed. The studies included randomized and non-randomized clinical trials, observational studies, and case series involving patients with distal femur fractures. Studies of other fracture patterns, studies conducted on children, pathological fractures, cadaveric studies, animal models, and those with non-clinical study designs were excluded. Results: 53 studies with 1788 patients were found to satisfy the inclusion and exclusion criteria. The most common harms were nonunion (14.8%), malunion (13%), fixation failure (5.3%), infection (3.7%), and symptomatic implant (3.1%). Time to full weight-bearing ranged from 5 to 24 weeks, averaging 12.3 weeks. The average duration of follow-up was 18.18 months, ranging from 0.5 to 108 months. Surgical time ranged between 40 and 540 min, with an average of 141 min. The length of stay in days was 12.7, ranging from 1 to 61. The average plate length was ten holes, ranging from 5 to 20 holes. Conclusion: This review aimed to systematically synthesize the available evidence on the risk associated with locked plating osteosynthesis in distal femur fractures. Nonunion is the most common harm and is the primary cause of reoperation. The overall combined risk of a major and critical complication (i.e., requiring reoperation) is approximately 20%.

Radiographic Union Assessment in Surgically Treated Distal Femur Fractures: A Systematic Review

BACKGROUND

Distal femur fractures are known to have challenging nonunion rates. Despite various available treatment methods aimed to improve union, optimal interventions are yet to be determined. Importantly, there remains no standard agreement on what defines radiographic union. Although various proposed criteria of defining radiographic union exist in the literature, there is no clear consensus on which criteria provide the most precise measurement. The use of inconsistent measures of fracture healing between studies can be problematic and limits their generalizability. Therefore, this systematic review aims to identify how fracture union is defined based on radiographic parameters for surgically treated distal femur fractures in current literature.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, Medline, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection databases were searched from inception to October 2022. Studies that addressed surgically treated distal femur fractures with reported radiographic union assessment were included. Outcomes extracted included radiographic definition of union; any testing of validity, reliability, or responsiveness; reported union rate; reported time to fracture union; and any functional outcomes correlated with radiographic union.

RESULTS

Sixty articles with 3,050 operatively treated distal femur fractures were included. Operative interventions included lateral locked plate (42 studies), intramedullary nail (15 studies), dynamic condylar screw or blade plate (7 studies), dual plate or plate and nail construct (5 studies), distal anterior-posterior/posterior-anterior screws (1 study), and external fixation with a circular frame (1 study). The range of mean follow-up time reported was 4.3 to 44 months. The most common definitions of fracture union included "bridging or callus formation across 3 of 4 cortices" in 26 (43%) studies, "bony bridging of cortices" in 21 (35%) studies, and "complete bridging of cortices" in 9 (15%) studies. Two studies included additional assessment of radiographic union using the Radiographic Union Scale in Tibial fracture (RUST) or modified Radiographic Union Scale in Tibial fracture (mRUST) scores. One study included description of validity, and the other study included reliability testing. The reported mean union rate of distal femur fractures was 89% (range 58%-100%). The mean time to fracture union was documented in 49 studies and found to be 18 weeks (range 12-36 weeks) in 2,441 cases. No studies reported correlations between functional outcomes and radiographic parameters.

CONCLUSION

The current literature evaluating surgically treated distal femur fractures lacks consistent definition of radiographic fracture union, and the appropriate time point to make this judgement is unclear. To advance surgical optimization, it is necessary that future research uses validated, reliable, and continuous measures of radiographic bone healing and correlation with functional outcomes.

LEVEL OF EVIDENCE

Level IV. See Instructions for Authors for a complete description of levels of evidence.

Geriatric distal femoral fractures: post-operative complications and nine-year mortality-a retrospective analysis of two tertiary trauma centres

PURPOSE

This study aimed to estimate the mortality at various post-operative intervals and explore influential variables for these outcomes in elderly patients with distal femur fractures (DFF).

METHODS

A retrospective observational study was conducted across two tertiary care institutions, between 2014 and 2020. The primary outcomes were mortality rates at 30-day, six month, and one year post-surgery. Secondary outcomes included 1-year readmission and reintervention rates along with their correlated complications.

RESULTS

A total of 37 DFF in 35 patients was analyzed; average age was 83.6 years (range, 65-98 years). The overall mortality rate at a maximum follow-up of 8.8 years was 74% (26/35 patients). The median survival time was 3.2 years and the survival probability at five years was 27% (95% confidence interval [CI], 13 to 43%). Mortality rates at 30 days, six months, and one year after surgery were 8.6% (3 patients), 23% (8 patients), and 34% (12 patients), respectively. Overall mortality rate was 64% (15/24 patients) for native distal femur fractures, and 92% (13/14 patients) for periprosthetic fractures (p = 0.109). Patients older than 85 years and male gender were identified as risk factors for mortality within the first year post-operatively.

CONCLUSION

Elderly fractures have a high mortality at eight years of follow-up. Mortality at one year was much higher than in other studies of the same nature. We did not find statistically significant differences when comparing native bone fractures with periprosthetic fractures. Factors that impact mortality were being a man, advanced age, elevated index comorbidity, and dementia. There is no relationship between the time to be taken to the surgical procedure and mortality results.

Early weight bearing versus late weight bearing after intramedullary nailing for distal femoral fracture (AO/OTA 33) in elderly patients: A multicenter propensity-matched study

BACKGROUND

This study aimed to assess differences in implant failure and bone union rates, amount of change in alignment of lower extremities, and walking ability between early weight-bearing (EWB) and late weight-bearing (LWB) groups following retrograde intramedullary nailing (RIMN) for distal femoral fracture (AO/OTA 33) (DFF) at multiple centers using propensity score matching.

METHODS

The data of 213 patients who underwent RIMN from 2012 to 2019 in multiple tertiary hospitals were extracted from our database. Cases with the following factors were excluded: age <60, open fracture, AO/OTA-type 33-C3 fracture, preoperative New Mobility Score (NMS) < 3, postoperative follow-up <3 months, and unknown weight-bearing start time. Eighty-four patients were divided into the EWB and LWB groups. EWB group patients were encouraged to perform partial weight-bearing walking at ≤4 weeks after surgery. LWB group patients were not allowed weight bearing for >4 weeks after surgery. After propensity score matching was applied, 26 cases remained in each group.

RESULTS

There were no cases of nail failure in either the EWB group or LWB group (P = 1). Screw failure occurred in 0 cases in the EWB group and in 1 case (4.5%) in the LWB group (P = 1.0). Non-union occurred in 5 patients (19.2%) in the EWB group and 4 patients (15.3%) in the LWB group (P = 1). The mean amount of change in lower extremities alignment did not differ between the two groups. The median Knee Society Score was 95.5 (59-100) vs. 93 (72-100) points (P = 0.39). The median NMS was 7 (0-9) vs. 7 (4-9) points (P = 0.82).

CONCLUSIONS

There were no significant intergroup differences in the rates of implant failure, bone union at one year after surgery, amount of change in lower extremities alignment, or walking ability. We suggest that early weight bearing after RIMN for DFF may not be harmful in elderly people.

Nonvascularized fibular graft with locking screw fixation for metaphyseal bone loss of distal femur: biomechanical assessment validated by a clinical case series

BACKGROUND

The optimal modality to surgically treat significant bone loss of distal femur remains inconclusive. The objectives of the present study were to assess the mechanical performance of nonvascularized fibular graft (NVFG) with locking screw fixation in distal femur fixation construct by finite element analysis and to retrospectively describe the outcomes of the present technique in clinical cases.

METHODS

Four constructs which the fractured femur was stabilized by LCP-DF alone, dual plating, LCP-DF combined with NVFG, and LCP-DF combined with NVFG (LCP-DF-NVFG-S) with locking screw were assessed the biomechanical performance under physiological loads. For the clinical case series, 12 patients with open intercondylar fracture with metaphyseal bone loss of distal femur were operated by LCP-DF-NVFG-S. The collected data included fracture consolidation, length of NVFG, perioperative complications and objective clinical results.

RESULTS

LCP-DF-NVFG-S demonstrated lower implant equivalent von Mises stress (EQV) stress and better fracture stability than other constructs. A locking screw presented its essence in maintaining the NVFG in the required position and subsequently enhancing the fracture stability. In regard to the clinical series, all fractures were consolidated with an average duration of 27.8 weeks (range 20-32). An average NVFG length was 7.8 cm (range 6-12). No perioperative complication was demonstrated. By the Knee Society score, 1 was considered to be excellent, 9 to be good and 2 to be poor.

CONCLUSION

Based on the results of mechanical assessment and case series, LCP-DF-NVFG-S can be an effective technique in the management of metaphyseal bone loss of distal femur.

On the importance of accurate elasto-plastic material properties in simulating plate osteosynthesis failure

Background: Plate osteosynthesis is a widely used technique for bone fracture fixation; however, complications such as plate bending remain a significant clinical concern. A better understanding of the failure mechanisms behind plate osteosynthesis is crucial for improving treatment outcomes. This study aimed to develop finite element (FE) models to predict plate bending failure and validate these against in vitro experiments using literature-based and experimentally determined implant material properties. Methods: Plate fixations of seven cadaveric tibia shaft fractures were tested to failure in a biomechanical setup with various implant configurations. FE models of the bone-implant constructs were developed from computed tomography (CT) scans. Elasto-plastic implant material properties were assigned using either literature data or the experimentally derived data. The predictive capability of these two FE modelling approaches was assessed based on the experimental ground truth. Results: The FE simulations provided quantitatively correct prediction of the in vitro cadaveric experiments in terms of construct stiffness [concordance correlation coefficient (CCC) = 0.97, standard error of estimate (SEE) = 23.66, relative standard error (RSE) = 10.3%], yield load (CCC = 0.97, SEE = 41.21N, RSE = 7.7%), and maximum force (CCC = 0.96, SEE = 35.04, RSE = 9.3%), when including the experimentally determined material properties. Literature-based properties led to inferior accuracies for both stiffness (CCC = 0.92, SEE = 27.62, RSE = 19.6%), yield load (CCC = 0.83, SEE = 46.53N, RSE = 21.4%), and maximum force (CCC = 0.86, SEE = 57.71, RSE = 14.4%). Conclusion: The validated FE model allows for accurate prediction of plate osteosynthesis construct behaviour beyond the elastic regime but only when using experimentally determined implant material properties. Literature-based material properties led to inferior predictability. These validated models have the potential to be utilized for assessing the loads leading to plastic deformation in vivo, as well as aiding in preoperative planning and postoperative rehabilitation protocols.

Combined nail-plate constructs in the management of osteoporotic native distal femoral fractures: a systematic review of the available evidence

PURPOSE

Distal femoral fractures account for 4-6% of fragility fractures. These may be managed using a combined nail-plate construct (NPC). The use of NPCs is gaining traction. Whilst several theoretical advantages exist, there is little evidence reporting on binary or patient-reported outcomes. The aim of the current study was to perform a systematic review of the available literature pertaining to NPCs and their treatment of native distal femoral fractures, appraising the outcomes and focusing on the rationale for their increasing uptake in recent literature.

METHODS

A comprehensive search of MEDLINE, EMBASE, Clinical Key, PubMed and Cochrane library was performed from date of inception up to in August 9, 2022. All study languages were included initially. A further Google Scholar search review was performed to identify any other studies not identified in the database interrogation. Studies were eligible if they reported on the use of nail-plate constructs in managing distal femoral fractures. Any outcome metric was permitted. The study was conducted in accordance with PRISMA guidelines. Risk of bias was assessed using the Methodological Index for non-randomised Studies tool. Quantitative analysis was performed using a log odds ratio random effects model. The Knapp-Hartung adjustment was utilised if the total number of included studies was < 5. Study effect sizes and appropriate plots were constructed to illustrate the outcomes data.

RESULTS

A total of four studies were eligible for inclusion. Study data was extracted and summarised with their relevant outcomes presented. The literature review demonstrated that the use of NPCs led to significantly earlier full weight bearing (p < 0.001) and had reduced non-union rates over a single construct, without affecting infection rates (12.5% vs. 5.6%; p = 0.289) and significantly lower implant failure rates (10.5% vs. 0%; p = 0.011). A meta-analysis is performed of available studies and Forrest plots presented.

CONCLUSION

The use of NPC in the management of native osteoporotic DFFs is gaining traction but the available evidence is of low grade with significant heterogeneity in small cohorts of patients. We suggest that a large-scale, multicentre prospective study should be performed, with agreed functional and radiological outcome metrics, to provide a more robust evidence base.

Mechanical evaluation of revision surgery for femoral shaft nonunion initially treated with intramedullary nailing: Exchange nailing versus augmentation plating

INTRODUCTION

Exchange nailing (EN) or augmentation plating (AP) has been employed to treat nonunions after intramedullary nailing for femoral shaft fractures. Although instability is a factor in hypertrophic nonunion, mechanical evaluations have been limited because the contribution of the callus to fracture site stability varies with healing. Our previous study illustrated the potential for evaluation using a finite element analysis (FEA) that incorporates callus material properties. This study aimed to mechanically evaluate revision surgery for nonunions using FEA.

MATERIALS AND METHODS

A quantitative computed tomography-based FEA was performed on virtual revision models of a patient with suspected nonunion after intramedullary nailing. In addition to the initial nailing model (IN) with an 11-mm diameter (D) and 360-mm length (L), four EN models with D12mm (EN1), D13mm (EN2), D12mm-L400mm (EN3), and D13mm-L400mm (EN4) nails and three AP models with 5- (AP1), 6- (AP2), and 7-hole (AP3) plates were created. As with bone, callus was assigned inhomogeneous material properties derived from density based on an empirical formula. The hip joint reaction force and muscle forces at maximum load during the gait cycle were applied. The volume ratio of the callus at the fracture site with a tensile failure risk of ≥1 (tensile failure ratio) and bone fragment movement were evaluated.

RESULTS

The tensile failure ratio was 11.6 % (IN), 10.1 % (EN1), 6.3 % (EN2), 10.9 % (EN3), 6.2 % (EN4), 6.4 % (AP1), 7.2 % (AP2), and 7.7 % (AP3), respectively. The bone fragment movement showed an opening on the lateral side with the initial intramedullary nailing. However, both revision surgeries reduced the opening, leading to compression except in the EN1 model. The proximal bone fragments were internally rotated relative to the distal fragments, and the rotational instability was more suppressed in models with lower tensile failure ratio.

CONCLUSIONS

For EN, the increase in diameter, not length, is important to suppress instability. AP reduces instability, comparable to a 2 mm increase in nail diameter, and screw fixation closer to the fracture site reduces instability. This study suggest that AP is mechanically equivalent to EN and could be an option for revision surgery for femoral shaft nonunions.

Biomechanical analysis of bridge combined fixation system as a novel treatment for the fixation of type A3 distal femoral fractures

Background

To compare the biomechanical parameters of AO/OTA type A3 distal femoral fractures fixed bilaterally with a bridge combined fixation system (BCFS) and lateral locking compression plate + locking reconstruction plate (LCP + LRP).

Methods

Twelve A3 distal femoral fracture models with medial cortical defects of the distal femur were created using synthetic femoral Sawbones. BCFS and LCP + LRP were used for bilateral fixation, with six in each group. Axial compression and torsion tests were performed on the two groups of fracture models to determine their stiffness during axial compression and the Torsional stiffness during torsion tests. Axial compression failure tests were performed to collect the vertical loads of the ultimate failure tests.

Results

In the test conducted on the fixed type A3 distal femoral fracture models, the axial stiffness in the BCFS group (group A) (1,072.61 ± 113.5 N/mm) was not significantly different from that in the LCP + LRP group (group B) (1,184.13 ± 110.24 N/mm) (t = 1.726, P = 0.115), the Torsional stiffness in group A (3.73 ± 0.12 N.m/deg) was higher than that in group B (3.37 ± 0.04 N.m/deg) (t = 6.825, P < 0.001),and the ultimate failure test of type A3 fracture model showed that the vertical load to destroy group A fixation (5,290.45 ± 109.63 N) was higher than that for group B (3,978.43 ± 17.1 N) (t = 23.28, P < 0.05). Notably, intertrochanteric fractures occurred in groups A and B.

Conclusions

In the fixation of type A3 distal femoral fractures, the anti-axial compression of the BCFS group was similar to that of the LCP + LRP group, but the anti-torsion was better.

Medial augmentation plating of aseptic distal femoral nonunions

BACKGROUND

Distal femur nonunions are well-recognized contributors to persistent functional disability, with limited data regarding their treatment options. In the current study, we asked whether additional medial augmentation plating is a feasible treatment option for patients with aseptic distal femoral nonunion and intact lateral implants.

METHODS

We conducted a single-center, retrospective study including 20 patients treated for aseptic distal femoral nonunion between 2002 and 2017. The treatment procedure included a medial approach to the distal femur, debridement of the nonunion site, bone grafting and medial augmentation plating utilizing a large-fragment titanium plate. Outcome measures were bone-related and functional results, measured by the Hospital for Special Surgery Knee Rating Scale (HSS) and the German Short Musculoskeletal Function Assessment questionnaire (SMFA-D).

RESULTS

Eighteen of 20 nonunions showed osseous healing at 8.16 ± 5.23 (range: 3-21) months after augmentation plating. Regarding functional results, the mean HSS score was 74.17 ± 11.12 (range: 57-87). The mean SMFA-D functional index was 47.38 ± 16.78 (range 25.74-71.32) at the last follow-up. Index procedure-associated complications included two cases of persistent nonunion and one case of infection.

CONCLUSIONS

According to the assessed outcome measures, augmentation plating is a feasible treatment option, with a high proportion of patients achieving bony union and good functional outcomes and a few patients experiencing complications.

[Translated article] Comparative clinical and biomechanical study of different types of osteosynthesis in the treatment of distal femur fractures

INTRODUCTION AND OBJECTIVES

Distal femoral fractures represent a problem due to their high number of complications. The aim was to compare the results, complications and stability achieved with retrograde intramedullary nailing and the angular stable plate in the treatment of distal femoral diaphyseal fractures.

MATERIAL AND METHOD

A clinical and experimental biomechanical study was carried out using finite elements. The results of the simulations allowed us to obtain the main results related to the stability of osteosynthesis. For clinical follow-up data, frequencies were used for qualitative variables, and Fisher's exact test and χ2 test were used to evaluate the significance of the different factors, with the condition of P<.05.

RESULTS

In the biomechanical study, the retrograde intramedullar nails demonstrated superiority, obtaining lower values in terms of global displacement, maximum tension, torsion resistance, and bending resistance. In the clinical study, the rate of consolidation of the plates was lower than nails (77% vs. 96%, P=.02). The factor that most influenced the healing of fractures treated with plate were the central cortical thickness (P=.019). The factor that most influenced the healing of nail-treated fractures was the difference between the diameter of the medullary canal and the nail.

CONCLUSIONS

Our biomechanical study shows that both osteosynthesis provide sufficient stability, but biomechanically behaves differently. Nails provide greater overall stability being preferable the use of long nails adjusted to the diameter of the canal. Plates form less rigid osteosynthesis, with little resistance to bending.

Comparative clinical and biomechanical study of different types of osteosynthesis in the treatment of distal femur fractures

INTRODUCTION AND OBJECTIVES

Distal femoral fractures represent a problem due to their high number of complications. The aim was to compare the results, complications and stability achieved with retrograde intramedullary nailing and the angular stable plate in the treatment of distal femoral diaphyseal fractures.

MATERIAL AND METHOD

A clinical and experimental biomechanical study was carried out using finite elements. The results of the simulations allowed us to obtain the main results related to the stability of osteosynthesis. For clinical follow-up data, frequencies were used for qualitative variables, and Fisher's exact test and χ2 test were used to evaluate the significance of the different factors, with the condition of P<.05.

RESULTS

In the biomechanical study, the retrograde intramedullar nails demonstrated superiority, obtaining lower values in terms of global displacement, maximum tension, torsion resistance, and bending resistance. In the clinical study, the rate of consolidation of the plates was lower than nails (77% vs. 96%, P=.02). The factor that most influenced the healing of fractures treated with plate were the central cortical thickness (P=.019). The factor that most influenced the healing of nail-treated fractures was the difference between the diameter of the medullary canal and the nail.

CONCLUSIONS

Our biomechanical study shows that both osteosynthesis provide sufficient stability, but biomechanically behaves differently. Nails provide greater overall stability being preferable the use of long nails adjusted to the diameter of the canal. Plates form less rigid osteosynthesis, with little resistance to bending.

Risk Factors for Nonunion of Distal Femur Fractures

OBJECTIVES

To determine patient, fracture, and construct related risk factors associated with nonunion of distal femur fractures.

DESIGN

Retrospective cohort study.

SETTING

Academic Level I trauma center.

PARTICIPANTS

Patients 18 years and older presenting with OTA/AO 33A and 33C distal femur fractures from 2004 to 2020. A minimum follow-up of 6 months was required for inclusion. OTA/AO 33B and periprosthetic fractures were excluded, 438 patients met inclusion criteria for the study.

MAIN OUTCOMES

The primary outcome of the study was fracture nonunion defined as a return to the OR for management of inadequate bony healing. Patient demographics, comorbidities, injury characteristics, fixation type, and construct variables were assessed for association with distal femur fracture nonunion. Secondary outcomes include conversion to total knee arthroplasty, surgical site infection, and other reoperation.

RESULTS

The overall nonunion rate was 13.8% (61/438). The nonunion group was compared directly with the fracture union group for statistical analysis. There were no differences in age, sex, mechanism of injury, Injury Severity Score, and time to surgery between the groups. Lateral locked plating characteristics including length of plate, plate metallurgy, screw density, and working length were not significantly different between groups. Increased body mass index [odds ratio (OR), 1.05], chronic anemia (OR, 5.4), open fracture (OR, 3.74), and segmental bone loss (OR, 2.99) were independently associated with nonunion. Conversion to total knee arthroplasty (TKA) ( P = 0.005) and surgical site infection ( P < 0001) were significantly more common in the nonunion group.

CONCLUSION

Segmental bone loss, open fractures, chronic anemia, and increasing body mass index are significant risk factors in the occurrence of distal femoral nonunion. Lateral locked plating characteristics did not seem to affect nonunion rates. Further investigation into the prevention of nonunion should focus on fracture fixation constructs and infection prevention.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Headless cannulated screw and external fixator in the treatment of type C distal femur fractures: Effect of early mobilization on clinical outcomes

Distal femur fractures occur due to high-energy trauma in young patients and with low-energy traumas in osteoporotic elderly patients. Implants selected for use in the treatment of distal femur fracture should provide stable fixation and allow early mobilization especially at elder patients. We aimed to investigate the effects of the headless cannulated screw and external fixator combination on the early mobilization of the patients and postoperative complications. Twenty-one patients with Type C distal femur fracture were included in the study.The fracture lines were temporarily fixed with K wires. After the fracture reduction with headless cannulated screws a tubular external fixator with carbon fiber rods was applied to bridge the knee joint. The external fixators were removed at the 6th week follow-up, and the patients were forced to perform knee flexion as much as they could tolerate. The 6th month KSS scores of the patients were 44.3 (34-60) and the 18th month KSS scores were 77.5 (60-88).Preoperative VAS score was 8(7-10) and postoperative VAS score was 4(3-6).Knee flexion of the patients at 6th months was 95.9 (80-110 degrees) and at 6th months knee flexion was 114.5 (100-125 degrees). Superficial pin site infection was observed at 4 patients and regressed with antibiotic therapy. Combination of cannulated screws with an external fixator for joint restoration in type C distal femur fractures allows early mobilization and reduces postoperative morbidity.

Outcome Evaluation of Distal Femoral Fractures Following Surgical Management: A Retrospective Cohort Study

BACKGROUND

Distal femur fractures are challenging in surgical management as the outcome is crucial for restoring the biomechanical stability and longitudinal axis of the leg and function of the knee joint.

METHODS

A retrospective review of all distal femoral fractures treated in a level I trauma center over a decade was performed. The radiographs were reviewed for fracture entity, osseous healing, implant failure, mechanical axis, and degenerative joint changes. Clinical outcome was reviewed regarding postoperative complications and postoperative range of motion of the knee joint.

RESULTS

130 patients who were managed with screw fixation (n = 35), plating systems (n = 92) or intramedullary nailing systems (n = 3) remained for evaluation. Mean follow up was 26 months. Clinical outcome was significantly better for flexion degrees following screw fixation (p = 0.009). Delayed fracture union (p = 0.002) or non-union (p = 0.006) rates were significantly higher in plate osteosynthesis. Mild pathologic deformity for varus and valgus collapse was found following plate osteosynthesis.

CONCLUSIONS

Screw fixation shows fewer postoperative complications than plate fixation and is favored for extra and partial intraarticular distal femur fractures. Plating constructs remain the superior fixation method in complex distal femur fractures but are associated with higher rates of non-union and leg axis deviation.

Advancing Osteoporosis Evaluation Procedures: Detailed Computational Analysis of Regional Structural Vulnerabilities in Osteoporotic Bone

Osteoporotic fractures of the femur are associated with poor healing, disability, reduced quality of life, and high mortality rates within 1 year. Moreover, osteoporotic fractures of the femur are still considered to be an unsolved problem in orthopedic surgery. In order to more effectively identify osteoporosis-related fracture risk and develop advanced treatment approaches for femur fractures, it is necessary to acquire a greater understanding of how osteoporosis alters the diaphyseal structure and biomechanical characteristics. The current investigation uses computational analyses to comprehensively examine how femur structure and its associated properties differ between healthy and osteoporotic bones. The results indicate statistically significant differences in multiple geometric properties between healthy femurs and osteoporotic femurs. Additionally, localized disparities in the geometric properties are evident. Overall, this approach will be beneficial in the development of new diagnostic procedures for highly detailed patient-specific detection of fracture risk, for establishing novel injury prevention treatments, and for informing advanced surgical solutions.

"Nailable" Does Not Always Mean Reducible in Distal Femur Fractures: Arthroplasty Component and Nail Design Matter

Distal femur fractures above a total knee arthroplasty (TKA) are challenging. These fractures can be fixed with a retrograde intramedullary nail (rIMN), but the design of the femoral component of the TKA influences the starting point for an rIMN. We performed a biomechanical study to evaluate how different TKA components influence the starting point for an rIMN and how that can lead to a deformity in the sagittal plane. We simulated a distal femur fracture with three different arthroplasty components. We used three different implants to simulate fracture reduction and measured the resultant sagittal plane deformity. Low and moderate femoral component ratio (FCR) design components were able to maintain fracture alignment within 5° of anatomic. High FCR component (more posterior starting point) sagittal plane deformities of up to 15° were observed with both the straight and medium Herzog bend nails, which was statistically significant (P<.001). Use of a high Herzog bend nail decreased the deformity by an average of 6°, which was statistically significant (P<.001). There is variability in how the TKA design affects the starting point and thus the sagittal plane alignment after fixation. This study helps quantify the effect of arthroplasty component design on fracture alignment. [Orthopedics. 2023;46(1):35-38.].

Analysis of 101 Mechanical Failures in Distal Femur Fractures Treated with 3 Generations of Precontoured Locking Plates

OBJECTIVES

To evaluate mechanical treatment failure in a large patient cohort sustaining a distal femur fracture treated with a distal femoral locking plate (DFLP).

DESIGN

This retrospective case-control series evaluated mechanical treatment failures of DFLPs.

SETTING

The study was conducted at 8 Level I trauma centers from 2010 to 2017.

PATIENTS AND PARTICIPANTS

One hundred one patients sustaining OTA/AO 33-A and C distal femur fractures were treated with DFLPs that experienced mechanical failure.

INTERVENTION

The intervention included the treatment of a distal femur fracture with a DFLP, affected by mechanical failure (implant failure by loosening or breakage).

MAIN OUTCOME MEASURE

The main outcome measures included injury and DFLP details; modes and timing of failure were studied.

RESULTS

One hundred forty-six nonunions were found overall (13.4%) including 101 mechanical failures (9.3%). Failures occurred in different manners, locations, and times depending on the DFLPs. For example, 33 of 101 stainless steel (SS) plates (33%) failed by bending or breaking in the working length, whereas no Ti plates failed here ( P < 0.05). Eleven of 12 failures with titanium-Less Invasive Stabilization System (92%) occurred by lost shaft fixation, mostly by the loosening of unicortical screws (91%). Sixteen of 44 variable -angled-LCP failures (36%) occurred at the distal plate-screw junction, whereas only 5 of 61 other DFLPs (8%) failed this way ( P < 0.05). Distal failures occurred on average at 23.7 weeks compared with others that occurred at 38.4 weeks ( P < 0.05). Variable -angled-LCP distal screw-plate junction failures occurred earlier (mean 21.4 weeks).

CONCLUSION

Nonunion and mechanical failure occurred in 14% and 9% of patients, respectively, in this large series of distal femur fracture treated with a DFLP. The mode, location, presence of a prosthesis, and timing of failure varied depending on the characteristics of DFLP. This information should be used to optimize implant usage and design to prolong the period of stable fixation before potential implant failures occur in patients with a prolonged time to union.

LEVEL OF EVIDENCE

Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Dual plating for fixation failure of the distal femur: Finite element analysis and a clinical series

BACKGROUND

The optimal technique for managing distal femur fixation failure remains inconclusive. The author studied the efficacy of a combined proximal humerus locking compression plate (LCP-PH) and 3.5 mm reconstruction plate (LCP-RP) by finite element (FE) analysis and retrospectively described the clinical outcomes of the present technique in such difficult circumstances.

METHODS

Biomechanical study setting included FE models of the distal femur with remaining holes from previous distal femur LCP (LCP-DF) fixation stabilized with three different constructs i.e., LCP-DF alone, LCP-DF-and-LCP-RP, as well as LCP-PH-and-LCP-RP. All settings were analyzed by using FE under physiological loads. Regarding the clinical series, the outcomes of 8 LCP-DF fixation failures operated on by the present technique were retrospectively reviewed.

RESULTS

High Implant stress of 911.2 MPa and elastic strain at fracture site of 200.8 µɛ were found when stabilized with LCP-DF. The constructs of LCP-DF-and-LCP-RP, and LCP-PH-and-LCP-RP presented lower implant stress compared to LCP-DF, 511.5, and 617.5 MPa, respectively. The elastic strain of both dual plating constructs was also 4-5 times lower than LCP-DF and differed from each other by approximately 10 µɛ. Regarding the clinical series, bony consolidation was achieved in all cases with a mean duration of 28.5 weeks (range 24-36). An average ROM of the affected knee was 115° (range 105-140). Regarding the KSS, 1 was determined to be excellent and 7 to be good.

CONCLUSION

By the biomechanical analysis and the clinical results, the construct of LCP-PH-and-LCP-RP could be an effective technique for revision surgery of LCP-DF fixation failure.

The comparison of stress and strain between custom-designed bone plates (CDBP) and locking compression plate (LCP) for distal femur fracture

BACKGROUND

Distal femur fracture is considered one of the most common fractures due to high-energy traumas such as car accidents or low-energy traumas such as osteoporosis. Locking plates are orthopedic implants used for stabilized femur fracture. Thus, designing a bone plate fitted exactly with the patient's bone and correctly fixing bone segments are required for better fracture healing.

OBJECTIVES

This study aims to design a bone plate based on anthropometric characteristics of patients' femurs and compare performing custom-designed bone plates (CDBP) with the locking compression plate (LCP) by finite element method.

MATERIALS AND METHODS

In this analytical study, a 3D model of four patients' femur and CDBP were firstly designed in MIMICS 19.0 based on the patient's femur anatomy. After designing the bone plate, the CDBPs and LCP were fixed on the bone and analyzed by finite element method (FEM) in ANSYS, and stress and strain of bone plates were also compared.

RESULTS

The maximum principal stress for all 3D models of patients' fracture femur by CDBPs was stabilized better than LCP with a decrease by 39.79, 12.54, 9.49, and 20.29% in 4 models, respectively. Also, in all models, the strain of CDBPs is less than LCP. Among the different thicknesses considered, the bone plate with 5 mm thickness showed better stress and strain distribution than other thicknesses.

CONCLUSION

Customized bone plate designed based on patient's femur anatomical morphology shows better bone-matching plate, resulting in increasing the quality of the fracture healing and fails to any need for additional shaping.

TRIAL REGISTRATION NUMBER

Design and analysis of an implant were investigated in this study. There was no intervention in the diagnosis and treatment of patients and the study was not a clinical trial.

Endosteal plating for the treatment of malunions and nonunions of distal femur fractures

PURPOSE

To describe the surgical technique and the outcome of a case series of nonunion and malunion of distal femur fractures treated with an endosteal medial plate combined with a lateral locking plate and with autogenous bone grafting.

METHODS

We retrospectively analyzed a series of patients with malunion or nonunion of the distal femur treated with a medial endosteal plate in combination with a lateral locking plate, in a period between January 2011 and December 2019, Database from chart review was obtained including all the clinical relevant available baseline data (demographics, type of fracture, mechanism of injury, time from injury to surgery, number of previous surgical procedures, type of bone graft, and type of lateral plate). Time to bone healing, limb alignment at follow-up and complications were documented.

RESULTS

Ten patients were included into the study: 7 male and 3 female with mean age of 48.3 years (range 21-67). The mechanism of trauma was in 8 cases a road traffic accident and in 2 cases a fall from height. According to AO/OTA classification 5 fractures were 33 A3, 3 were 33 C1, 1 was 33 C2 and 1 was 33 C3. The average follow up was 13.5 months. In all cases but one bony union was achieved. Bone healing was observed in average 3.3 months after surgery. No intraoperative or postoperative complications were reported.

CONCLUSION

A medial endosteal plate is a useful augmentation for lateral plate fixation in nonunion or malunion following distal femur fractures, particularly in cases of medial bone loss, severe comminution, or poor bone quality.

LEVEL OF EVIDENCE

Level IV (retrospective case series).

DISTAL FEMORAL FRACTURES FROM HIGH-ENERGY TRAUMA: A RETROSPECTIVE REVIEW OF COMPLICATION RATE AND RISK FACTORS

Objective

Determine complications' incidence and risk factors in high-energy distal femur fractures fixed with a lateral locked plate.

Methods

Forty-seven patients were included; 87.2% were male, and the average age was 38.9. The main radiographic parameters collected were distal lateral femoral angle (DFA), distal posterior femoral angle (DPLF), comminution length, plate length, screw working length, bone loss, and medial contact after reduction and plate-bone contact, location of callus formation, and implant failure. The complications recorded were nonunion, implant failure, and infection.

Results

Complex C2 and C3 fractures accounted for 85.1% of cases. Open fractures accounted for 63.8% of cases. The mean AFDL and AFDP were 79.8 4.0 and 79.3 6.0, respectively. The average total proximal and distal working lengths were 133.3 42.7, 60.4 33.4, and 29.5 21.8 mm, respectively. The infection rate was 29.8%, and the only risk factor was open fracture (p = 0.005). The nonunion rate was 19.1%, with longer working length (p = 0.035) and higher PDFA (p = 0.001) as risk factors. The site of callus formation also influenced pseudoarthrosis (p = 0.034).

Conclusion

High-energy distal femoral fractures have a higher incidence of pseudoarthrosis and infection. Nonunion has greater working length, greater AFDL, and absence of callus formation on the medial and posterior sides as risk factors. The risk factor for infection was an open fracture. Level of Evidence III; Retrospective Cohort Study .

Evaluation of bone healing process after intramedullary nailing for femoral shaft fracture by quantitative computed tomography-based finite element analysis

BACKGROUND

There is no proven method for quantitative evaluation of bone healing progress or decision to remove the nail after intramedullary nailing for femoral shaft fractures. Finite element analysis has become commonly utilized in bone analysis, but it may also be used to evaluate callus. The goal of this study was to use quantitative CT-based finite element analysis to assess the bone healing process and predict bone strength with the nail removed.

METHODS

Quantitative CT-based finite element analysis was conducted on CT images from patients who had intramedullary nailing after a femoral shaft fracture at 6, 12, and 15 months postoperatively. The failure risk of the callus was evaluated with maximal load throughout the gait cycle. The tensile failure ratio was calculated using the volume ratio of the callus element with a tensile failure risk ≥100%. A virtual model with the nail removed was built for bone strength study, and the strength was calculated using the displacement-load curve.

FINDINGS

The tensile failure ratio reduced with time, reaching 11.6%, 2.6%, and 0.5% at 6, 12, and 15 months postoperatively, respectively, consistent with bone healing inferred from imaging results. At 15 months, the bone strength at nail removal grew to 212, 2670, and 3385 N, surpassing the healthy side's 2766 N.

INTERPRETATION

Quantitative CT-based finite element analysis enables mechanical assessment during the bone healing process and is expected to be applied to the selection of revision surgery. It is also applicable to the nail removal decision.

Does distance from joint line influence complications after distal femur fractures in native and periprosthetic knees?

BACKGROUND

Distal femur fractures are projected to increase in incidence secondary to an aging population and growing utilization of total knee arthroplasty. Surgical management is the standard of care, but optimal treatment for far distal fractures is still unclear. Our study investigates if there are distal femur fractures too distal to be treated with lateral locked plating in periprosthetic fractures.

METHODS

One hundred and ten consecutive patients treated with locked plating for distal femur fractures around a total knee replacement were identified using CPT codes. Fractures were classified by length of the distal fracture segment and Su classification. Complications studied were nonunion, malunion, infection, further fracture related surgery, readmission within 90 days, and mortality within 1 year of surgery. Sixty six fractures met inclusion criteria of 180 days of follow-up or sustaining a complication prior to180 days.

RESULTS

The size of the distal fracture segment and Su classification did not correlate with increased complication rate in periprosthetic distal femur fractures.

CONCLUSIONS

There was no difference between complications following lateral locked plating of distal femur fractures based on the size of the distal fracture segment in periprosthetic fractures. Lateral locked plating is an effective treatment modality for these fractures regardless of how distal the fracture extends.

Practical approach to the native distal femur fractures in the elderly: A rapid review over the recent trends

Significant work has been done in recent years on treatment strategies for distal femur fractures. Inclusive reviews on periprosthetic fractures of distal femur have been carried out recently, but there is a lack of such reviews on the subject of native distal femur fractures in the recent literature. In this narrative review, we are set out to address the latest updates on geriatric non-periprosthetic distal femur fractures, and perform a rapid review over different treatment options, arriving at a summarized proposed treatment algorithm.

[Distal femoral fractures]

CLINICAL ISSUE

Fractures of the distal femur represent rare but serious injuries with a high 1‑year mortality. An increasingly older patient population requires adapted treatment concepts.

STANDARD TREATMENT PROCEDURE

Surgical treatment using angular stable plating and retrograde nailing is the standard procedure. Conservative treatment is only indicated in cases of low demands and high perioperative risks of the patient.

TREATMENT INNOVATIONS

Primary double plate osteosynthesis and primary implantation of a distal femoral replacement represent new treatment procedures and show promising initial results in the collective of geriatric patients.

DIAGNOSTIC WORK-UP

Conventional radiographs in 2 planes and computed tomography with multiplanar and 3D reconstructions should be performed to enable an adequate assessment of the indications and treatment planning.

PERFORMANCE

Nonunion rates of plate and nail osteosyntheses range from 4% to 10%. No significant differences in long-term results can be observed. The results regarding double plate osteosynthesis and distal femoral replacement so far do not show any disadvantages compared to the existing procedures but there is still insufficient data for general recommendations.

ASSESSMENT

Complex fractures with extensive reconstructive procedures and treatment by distal femoral replacement should be performed in specialized centers.

PRACTICAL RECOMMENDATIONS

The gold standard is still surgical treatment by means of minimally invasive angular stable plate or retrograde nail osteosynthesis. Complex fracture forms require individual treatment planning considering all currently available treatment options.

Revision Surgery Using Retrograde Nail versus Replating in Nonunion Distal Femur Fracture Treated with Plate

Articular distal femur fractures represent 4% to 6% of femur fractures. Locking compression plates (LCPs) are the main treatment option. Nevertheless, a reoperation rate of 12.9% has been reported; nonunion is reported at 4.8%, delayed union at 1.6%, and malunion at 0.6%. Treatment of nonunions can be challenging as no unanimous consensus regarding the best surgical technique has been reached. The aim of this study was to evaluate and compare two types of revision surgery as treatment of LCP-treated articular distal femoral fracture nonunion: retrograde nail or replating. A retrospective cohort study of patients admitted from January 2015 to February 2017 for nonunion of AO/OTA 33C2 fractures previously treated with a lateral LCP was conducted. Patients were treated either with intramedullary nailing (Group A) or with replating (Group B). One independent observer performed clinically and radiographically followed up at 1, 3, 6, 9, 12, 24, and 36 months after surgery. The nonunion scoring system (NUSS) was used. Nine patients were included in our study. The mean follow-up was 2 years. Five patients were treated with intramedullary nailing and four with replating. The NUSS score was 24.2 ± 6.8 in the nailing group and 37.3 ± 3 in the replating group (P=0.03). In the nailing group, radiographic consolidation was obtained in all cases. In the replating group, nonunion was found in 3 patients and failure of osteosynthesis in one patient. Therefore, four patients (Group B) underwent implant removal and retrograde femoral nailing, obtaining radiological healing. The union time was 7.6 months in the nailing group. Retrograde intramedullary nailing can be used as an effective treatment of aseptic AO-33C distal femoral nonunion following primary locking plating.

Intramedullary bone pedestal formation contributing to femoral shaft fracture nonunion: A case report and review of the literature

BACKGROUND

Femoral shaft fracture is a commonly encountered orthopedic injury that can be treated operatively with a low overall delayed/nonunion rate. In the case of delayed union after antegrade or retrograde intramedullary nail fixation, fracture dynamization is often attempted first. Nonunion after dynamization has been shown to occur due to infection and other aseptic etiologies. We present a unique case of diaphyseal femoral shaft fracture nonunion after dynamization due to intramedullary cortical bone pedestal formation at the distal tip of the nail.

CASE SUMMARY

A 37-year-old male experienced a high-energy trauma to his left thigh after coming down hard during a motocross jump. Evaluation was consistent with an isolated, closed, left mid-shaft femur fracture. He was initially managed with reamed antegrade intramedullary nail fixation but had continued thigh pain. Radiographs at four months demonstrated no evidence of fracture union and failure of the distal locking screw, and dynamization by distal locking screw removal was performed. The patient continued to have pain eight months after the initial procedure and 4 mo after dynamization with serial radiographs continuing to demonstrate no evidence of fracture healing. The decision was made to proceed with exchange nailing for aseptic fracture nonunion. During the exchange procedure, an obstruction was encountered at the distal tip of the failed nail and was confirmed on magnified fluoroscopy to be a pedestal of cortical bone in the canal. The obstruction required further distal reaming. A longer and larger diameter exchange nail was placed without difficulty and without a distal locking screw to allow for dynamization at the fracture site. Post-operative radiographs showed proper fracture and hardware alignment. There was subsequently radiographic evidence of callus formation at one year with subsequent fracture consolidation and resolution of thigh pain at eighteen months.

CONCLUSION

The risk of fracture nonunion caused by intramedullary bone pedestal formation can be mitigated with the use of maximum length and diameter nails and close follow up.

Low-Intensity Pulsed Ultrasound in the Treatment of Nonunions and Fresh Fractures: A Case Series

It is estimated that approximately 5% to 10% of fractures will evolve into nonunions. Nonunions have a significant impact on patient quality of life and on socioeconomic costs. Low-intensity pulsed ultrasound (LIPUS) is a non-invasive therapy widely used within the orthopedic community to accelerate the healing of fresh fractures, to minimize delayed healing, and to promote healing of nonunions. In this case series, 46 nonunions and 19 fresh fractures were treated with LIPUS for at least three months or until fracture healing. Bone healing was assessed both at a radiological and a functional level. Of the nonunions healed, 89% had a mean healing time of 89 ± 53 days. In the group of fresh fractures, the healing percentage was 95% with a mean healing time of 46 ± 28 days. LIPUS treatment is proven to be safe and well tolerated; there were no adverse events related to the use of the device, even in the presence of internal fixations and infections. LIPUS therapy should be considered a low-risk option both as an adjunct to surgery or as a standalone therapy in the management of nonunion and fresh fractures.

Immediate Full Weight-Bearing Versus Partial Weight-Bearing After Plate Fixation of Distal Femur Fractures in Elderly Patients. A Randomized Controlled Trial

Introduction

After surgery for distal femur fractures in elderly patients, weight-bearing is commonly restricted. Immediate non-restrictive weight-bearing might have beneficial effects. There are no randomized studies on the topic. The purpose of this study was to compare the functional outcome between immediate full weight-bearing (FWB) as tolerated and partial weight-bearing (PWB) during the first 8 weeks following plate fixation of distal femur fractures in elderly patients.

Methods

Patients aged 65 years or older with distal femur fractures of AO/OTA types 33 A2, A3, B1, B2, C1, and C2 were included. Exclusion criteria were impaired cognitive function, concomitant injuries, or inability to follow the postoperative regimen. Internal fixation was achieved with an anatomical lateral distal femur plate applied as a strictly bridge-plating construct. The primary outcome measure was the function index of the short musculoskeletal functional assessment (SMFA) after 52 weeks from injury.

Results

Thirty-two patients were randomized to FWB (n = 11) or PWB (n = 21). After 16 and 52 weeks, there were no differences in the mean SMFA function index between FWB and PWB (36 vs 43, P = .42 and 52 vs 40, P = .18, respectively) nor in the mean EuroQol 5-dimension index or range of motion (ROM). Overall, the SMFA function index was higher at 52 weeks compared with before injury (44 vs 30, P = .001) as was the mean bothersome index (37 vs 21, P = .011). There was no clear difference in the occurrence of adverse events between the treatment groups.

Conclusions

There were no differences in functional outcome, adverse events, or ROM between immediate FWB and PWB following plate fixation for a distal femur fracture in elderly patients. A distal femur fracture has a negative effect on the functional status of elderly patients that persists at least up to 1 year following injury.

A Comparison of Acute Complications and Mortality Between Geriatric Knee and Hip Fractures: A Matched Cohort Study

INTRODUCTION

To compare acute complication and mortality rates for operatively treated, closed, isolated, low-energy geriatric knee fractures (distal femur [DFF] or tibial plateau [TPF]) with hip fractures (HFs).

METHODS

This is a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program. We identified all patients ≥ 70 years from 2011 to 2016 who underwent surgery for DFF, TPF, or HF. We recorded patient demographics, functional status, complications, and mortality. We matched DFF:TPF:HF patients on a 1:1:10 ratio based on age, sex, body mass index, baseline functional status, and comorbidity. We used the chi square, Fisher exact, and Mann Whitney U tests to compare unadjusted differences between groups and multivariable logistic regression to compare the risk of complications, readmission, or death while adjusting for relevant covariates.

RESULTS

When compared with HF, patients in the DFF and TPF groups had longer length of stay and time to index surgery and were more likely to be discharged home. The rate of deep vein thrombosis was significantly higher in the TPF group (TPF = 3.9%, DFF = 1.3%, and HF = 1.2%, P = 0.005).

CONCLUSION

Geriatric knee fractures pose a similar risk of acute complications, mortality, and readmission compared with patients with HF. Future studies investigating strategies to decrease risk in this patient cohort are warranted.

LEVEL OF EVIDENCE

Therapeutic Level III.

Hybrid locked medial plating in dual plate fixation optimizes the healing of comminuted distal femur fractures: A retrospective cohort study

OBJECTIVES

Dual plate fixation has been reported to be effective in the treatment of comminuted distal femur fractures (DFFs). However, optimized use of the medial plate and screws is less studied. This study aimed to evaluate the effect of a hybrid configuration of the medial plate in dual plate fixation of comminuted DFFs in promoting fracture healing.

MATERIALS AND METHODS

We retrospectively analyzed 62 patients with comminuted DFFs (AO/OTA 33-A3/33-C2/33-C3) from January 2015 to March 2020, who were either fixed with lateral locked plating augmented with hybrid locked medial plating (LP-HLMP, n = 32) or lateral locked plating (LLP, n = 30) alone. Specifically, compression screws were applied in the middle of the medial plate and flanked by locking ones at both ends. Baseline characteristics, radiological and clinical outcomes were reviewed and analyzed. Multivariate logistic regression analysis was used to identify predictive factors for early fracture healing, and risk factors for delayed union/nonunion.

RESULTS

Demographics including age, gender, smoking, diabetes, and injury mechanism were comparable between the two groups. Reduction quality was better in the LP-HLMP group (p < 0.001). Although the LP-HLMP group experienced longer duration of surgery (125 min vs. 100 min, p < 0.001), sign of healing at 3 months was more obvious in this group (75%, 24/32 vs. 30%, 9/30; p < 0.001). The LP-HLMP group also presented with higher union rate (93.8%, 30/32 vs. 56.7%, 17/30; p = 0.001) and lower reoperation rate (0%, 0/32 vs. 13.3%, 4/30; p = 0.049). Kolment score showed no statistical significance between the two groups. Multivariate analysis revealed that younger age (< 60 years) (OR 5.99, 95%CI 1.16 - 31.03; p = 0.001) and LP-HLMP fixation (OR 45.90, 95% CI 4.78 - 440.56; p = 0.001) predict early healing; while smoking (OR 17.80, 95% CI 2.41 - 131.49; p = 0.01) and fracture translation (OR 3.49, 95% CI 1.46 - 8.32; p = 0.01) were identified as risk factors for delayed union/nonunion.

CONCLUSION

Hybrid locked medial plating in this study favors the healing of comminuted DFFs and reduces reoperation. Additionally, smoking and suboptimal reduction (translation) predict delayed union/nonunion.

Should Femoral Shaft fractures in Patients Age Over 60 Years be Managed Using a Hip Fracture Pathway?

INTRODUCTION

The British Orthopaedic Association published 2019 guidelines 'The Older or Frail Orthopaedic Trauma Patient'. This implements principles of the hip fracture pathway to all fragility fractures. Like hip fractures, femoral shaft fractures in the elderly are also suggested to represent fragility fractures. Femoral shaft fractures in older patients are rare and there is scarce literature detailing their outcomes. We aim to review outcomes of femoral shaft fractures in patients age 60 years and over at our institution and compare them to that of the hip fracture population.

MATERIALS AND METHODS

We retrospectively reviewed clinical records of a consecutive cohort of patients aged 60 years and over, who sustained a femoral shaft fracture, over a five-year period at our institution. Outcome measures studied were time to surgery, mean length of admission, readmission rate within 30 days, medical and orthopaedic complications, one month and one year mortality.

RESULTS

We identified 53 patients with a mean age of 78.7 years. On average patients each had 2.7 medical comorbidities. Mean length of admission was 20.0 days and readmission rate within 30 days was 19.1% (n=9). Medical complications affected 41.5% of patients (n=22) and orthopaedic complications affected 9.4% of patients (n=5). Two patients demonstrated nonunion and one patient required revision surgery. Thirty day mortality rate was 13.2% (n=7) which increased to a one year mortality of 26.4% (n=14).

CONCLUSION

Patients age 60 years and over with femoral shaft fractures have poor medical outcomes and prolonged length of admission. Compared to patients with hip fractures, medical complication rates are at least twice the 13-20% reported for hip fractures. The 30 day mortality rate in patients with femoral shaft fractures was also more than double the 6.1% reported for hip fracture patients by The National Hip Fracture Database in 2018. Femoral shaft fractures are associated with high medical morbidity and mortality. The hip fracture pathway is encompassed in the British Orthopaedic Association guidelines and emphasizes early medical input and a multidisciplinary approach to patient management. Hence, our study supports implementation of these guidelines with aim to improve morbidity and mortality of this vulnerable patient group.

Research status of biodegradable metals designed for oral and maxillofacial applications: A review

The oral and maxillofacial regions have complex anatomical structures and different tissue types, which have vital health and aesthetic functions. Biodegradable metals (BMs) is a promising bioactive materials to treat oral and maxillofacial diseases. This review summarizes the research status and future research directions of BMs for oral and maxillofacial applications. Mg-based BMs and Zn-based BMs for bone fracture fixation systems, and guided bone regeneration (GBR) membranes, are discussed in detail. Zn-based BMs with a moderate degradation rate and superior mechanical properties for GBR membranes show great potential for clinical translation. Fe-based BMs have a relatively low degradation rate and insoluble degradation products, which greatly limit their application and clinical translation. Furthermore, we proposed potential future research directions for BMs in the oral and maxillofacial regions, including 3D printed BM bone scaffolds, surface modification for BMs GBR membranes, and BMs containing hydrogels for cartilage regeneration, soft tissue regeneration, and nerve regeneration. Taken together, the progress made in the development of BMs in oral and maxillofacial regions has laid a foundation for further clinical translation.

Efficacy and Safety of Long-Term Intravenous Tranexamic Acid Administration for Blood Management in Revision Surgery for Femoral Shaft Nonunion: A Retrospective Case-Control Study

Femoral shaft nonunion is a complication that seriously affects physiological functions. We aimed to assess the effectiveness and safety of short- and long-term intravenous tranexamic acid (TXA) administration in the perioperative period of revision surgery for femoral shaft nonunion. In this retrospective study, 53 patients undergoing double-locking plates with channel bone grafting technology for the treatment of femoral shaft nonunion were divided into 3 groups: the patients in group A without use TXA during hospitalization, the patients in group B received intravenous (IV) 1-g TXA at 30 min before the surgery and deep soaked 1-g TXA for 5 min before closing the incision, and then 1-g TXA IV again 6 h after surgery, and the patients in group C received 1-g TXA IV before the operation, 1-g TXA topically during the operation, and subsequent long-term 1-g TXA IV until discharged. The primary outcomes were total blood loss (TBL) and hidden blood loss (HBL). The secondary outcomes included actual hemoglobin (Hb) loss values, transfusion requirement, number of units transfused, postoperative laboratory values (Hb, hematocrit, fibrinogen, and D-dimer), visual analogue scale (VAS) scores, and hospitalization time. The mean TBL was lower in group C than in group A (1168 mL vs. 2714 mL, P < 0.001) and group B (1168 mL vs. 1557 mL, P = 0.008). The differences in HBL volumes were also significant between groups A and C (P < 0.001) and between groups A and B (P < 0.01). The actual Hb loss in the 3 groups showed a consistent trend with TBL, but no significant differences between groups B and C (P = 0.23). On postoperative day (POD) 3, the Hb level was higher in group C than in group A (111.1 g/L vs. 94.6 g/L, P = 0.02). No significant differences were found in VAS, hospital stay, thromboembolic complications, incision-related complications, and TXA adverse reactions among groups. Long-term intravenous TXA during hospitalization can effectively reduce perioperative blood loss, Hb drop, and postoperative hyperfibrinolysis, but is associated with an increased incidence of adverse reactions.

The flipped third fragment in femoral shaft fractures: A reason for open reduction?

OBJECTIVES

First introduced by Kuntscher in the 1940s, closed intramedullary nailing of femoral shaft fractures has become the standard of care, with reported union rates up to 99% in some series. However, fractures with large intercalary segments, which are present in 10-34% of femoral shaft fractures, present unique challenges. In particular, how to treat flipped intercalary segments has remained controversial, with some advocating open reduction of these fractures. The purpose of this study was to evaluate the union rates of femoral shaft fractures with flipped intercalary segments treated with closed reduction and intramedullary nail fixation.

METHODS

A retrospective review of patients with femoral shaft fractures and flipped intercalary segments from January 2000 until January 2018 was performed at a single academic level one tertiary care referral center. All patients between the ages of 16-80 with minimum 6-month follow-up were included. Union rates were evaluated using the radiographic union score of the femur (RUSF). Patients with non-diaphyseal femur fractures, pathologic fractures, incomplete radiographic or clinical follow-up, or open reduction at the time of initial surgery were excluded.

RESULTS

Twenty-six patients (18 male and 8 female) with a mean age of 32 years (SD 12.8, range 19-65 years) and mean follow-up of 15.9 months (range, 6-82 months) met inclusion criteria. Seven patients had open fractures. The mean size of the flipped intercalary segments was 71.3 mm (range: 30-174 mm), with mean displacement of 6.6 mm (range: 1-37 mm). The mean radiographic union scale in femoral (RUSF) at 6 months was 9 (standard deviation: 1.35). There were two patients who went on to non-union. The overall union rate was 92% (24 patients); the non-union rate was 8% (2 patients).

CONCLUSIONS

Though uncommon, femoral shaft fractures with flipped intercalary segments present unique challenges to surgical treatment. While previous studies have found the presence of large intercalary segments to be associated with higher rates of non-union, the results of this study challenge prior evidence. In conclusion, the presence of flipped intercalary segments may not require different surgical management than the treatment of conventional femoral shaft fractures.

LEVEL OF EVIDENCE

IV.

Incidence of nonunion after surgery of distal femoral fractures using contemporary fixation device: a meta-analysis

PURPOSE

Nonunion is the most frequent cause of reoperation and is associated with high morbidity after distal femur fracture (DFF). We examined the rates of nonunion requiring reoperation after fixation for DFF using a locking compression plate (LCP) or retrograde intramedullary nail (RIMN).

METHODS

We included four studies comparing LCP and RIMN and 38 single-cohort studies reporting LCP or RIMN. In total, 2156 femurs were included and 166 non-unions were detected. We conducted a pair-wise meta-analysis (with a fixed-effects model) on the four comparative studies and a proportional meta-analysis on the 38 articles to estimate the nonunion rate. We performed sensitivity analysis by comparing studies using LCP with less invasive surgical systems (LISS) with those that used RIMN.

RESULTS

The pairwise meta-analysis showed a similar nonunion rate between the groups [odds ratio: 1.02; 95% confidence interval (CI) 0.94-1.11, p = 0.633]. According to proportional meta-analysis, the pooled prevalence of nonunion was 5% (95% CI 4-7) totally, 6% (95% CI 4-8) in the LCP group, and 4% (95% CI 2-6) in the RIMN group (heterogeneity: p = 0.105). According to the sensitivity analysis, there was no difference in the union rate. The pooled prevalence of nonunion from sensitivity analysis was 4 % (95% CI, 3-5); it was 4% (95% CI, 3-6) in LCP with LISS and was 4% (95% CI, 2-6) in RIMN group (heterogeneity: p = 0.941).

CONCLUSION

Approximately 5% of patients who underwent LCP or RIMN fixation developed nonunion. Therefore, LCP and RIMN are effective DFF techniques and mastering one of them is essential.

Intramedular fixation after breaking of the femoral plate

Any fracture of the femoral shaft presents a challenge to the orthopedic surgeon. Femoral fractures most often occur within polytrauma, by forces of high intensity as is the case with traffic accidents. There are two methods to treat with internal fracture fixation, intra and extra medullary fixation. Both treatments have their advantages and disadvantages and it is necessary to make a good preoperative plan. We present the case of a 23-year-old man who suffered a femoral shaft fracture as a driver in a car accident. He was initially surgically treated with orthopedic repositioning and internal, extramedullary fixation. After 18 months, bending of the osteosynthetic material and dislocation of the fragments with varus and recurvatum were verified. Oligotrophic pseudoarthrosis was also present. Reintervention and fixation with interlocking nail was performed. The weight bearing is allowed after two weeks. After 3 months, patient has full range of motion and there is no palpatory painful sensitivity. Intramedullary fixation is the method of choice for fractures of the femur, especially when there is no comminution and in cases of open fractures of the first and second degree. Rotation of fragments is locked, physical rehabilitation is faster and there is less risk of mal union.

Biomechanical design using in-vitro finite element modeling of distal femur fracture plates made from semi-rigid materials versus traditional metals for post-operative toe-touch weight-bearing

This proof-of-concept study designs distal femur fracture plates from semi-rigid materials vs. traditional metals for toe-touch weight-bearing recommended to patients immediately after surgery. The two-fold goal was to (a) reduce stress shielding (SS) by increasing cortical bone stress thereby reducing the risk of bone absorption and plate loosening, and (b) reduce delayed healing (DH) via early callus formation by optimizing axial interfragmentary motion (AIM). Finite element analysis was used to design semi-rigid plates whose elastic moduli E ensured plates permitted AIM of 0.2 - 1 mm for early callus formation. A low hip joint force of 700 N (i.e. 100% x body weight) was applied, which corresponds to a typical 140 N toe-touch foot-to-ground force (i.e. 20% x body weight) recommended to patients after surgery. Analysis was done using 2 screw materials (steel or titanium) and types (locked or non-locked). Steel and titanium plates were also analyzed. Semi-rigid plates (vs. metal plates) had lower overall femur/plate construct stiffnesses of 508 - 1482 N/mm, higher cortical bone stresses under the plate by 2.02x - 3.27x thereby reducing SS, and lower E values of 414 - 2302 MPa to permit AIM of 0.2 - 1 mm thereby reducing DH.

Clinical outcomes of revision with retrograde intermedullary nailing for failed plating of distal femoral fractures: a retrospective study

PURPOSE

To assess the feasibility and effectiveness of retrograde intramedullary nail (RIN) revision surgeries for locking compression plate (LCP) failure in distal femoral fractures.

METHODS

This retrospective study included 13 patients who suffered from metalwork failures after they initially underwent open reduction and LCP fixation. In patients who eventually underwent RIN revision from January 2014 to December 2016, range of motion (ROM) and Hospital for Special Surgery (HSS) scores obtained before surgery and at the final follow-up time were analysed.

RESULTS

The average operative time was 155 minutes (range, 120-210 minutes), and the average blood loss volume was 650 ml (range, 200-1350 ml). There were two cases of complications (15.38%): one was calf muscle vein thrombosis, and the other was a superficial infection. No deep tissue infection or deep vein thrombosis was observed post-operatively. The average follow-up time was 16 months (range, 12-24 months). All fractures healed in a mean of 6.5 months (range, 4-12 months), and one patient underwent an additional bone graft surgery that did not involve a bone graft during the RIN revision operation (this eventually healed at 12 months post-operatively). The mean ROM before the operation was 86.92 ± 12.34°. At the final follow-up, the mean ROM was 112.69 ± 9.27°. There was a significant difference between pre-operative and post-operative ROM (P < 0.01). The mean HSS score improved significantly from 38.85 ± 9.62 points pre-operatively to 79.62 ± 5.42 points post-operatively. There was a significant difference between pre-operative and post-operative HSS scores (P < 0.01).

CONCLUSIONS

RIN revision surgery achieved excellent clinical results in patients with LCP failure.

J-bone graft with double locking plate: a symphony of mechanics and biology for atrophic distal femoral non-union with bone defect

Objective

Atrophic distal femur non-union with bone defect (ADFNBD) has been a worldwide challenge to treat due to the associated biological and mechanical problems. The purpose of this study was to introduce a new solution involving the use of a J-shaped iliac crest bone graft (J-bone) combined with double-plate (DP) in the treatment of femoral non-union.

Methods

Clinically, 18 patients with ADFNBD were included in this retrospective study and were treated with a combination of J-bone graft and DP. The average follow-up time was 22.1 ± 5.5 months (range, 14 to 34 months). The imaging information and knee joint activity tests and scores were used to evaluate the time to weight-bearing, the time to non-union healing, and the knee joint mobility. A finite element analysis was used to evaluate the differences between the following: (1) the use of a lateral locking plate (LLP) only group (LLP-only), (2) a DP only group (DP-only), (3) a DP with a J-bone group (DP+J-bone), and (4) an LLP with a J-bone group (LLP+J-bone) in the treatment of ADFNBD. A finite element analysis ABAQUS 6.14 (Dassault systems, USA) was used to simulate the von Mises stress distribution and model displacement of the plate during standing and normal walking.

Result

All patients with non-union and bone defect in the distal femur achieved bone healing at an average of 22.1 ± 5.5 months (range, 14 to 34 months) postoperatively. The average healing time was 6.72 ± 2.80 months. The knee Lysholm score was significantly improved compared with that before surgery. Under both 750 N and 1800 N axial stress, the maximum stress with the DP+J-bone structure was less than that of the LLP+J-bone and DP-only structures, and the maximum stress of J-bone in the DP+J-bone was significantly less than that of the LLP+J-bone+on structure. The fracture displacement of the DP+J-bone structure was also smaller than that of the LLP+J-bone and DP-only structures.

Conclusion

J-bone combined with DP resulted in less maximum stress and less displacement than did a J-bone combined with an LLP or a DP-only graft for the treatment of ADFNBD. This procedure was associated with less surgical trauma, early rehabilitation exercise after surgery, a high bone healing rate, and a satisfactory rate of functional recovery. Therefore, a combination of J-bone and DP is an effective and important choice for the treatment of ADFNBD.

``Sandwich technique" with dual strut allograft in surgical treatment of femoral nonunion

OBJECTIVE

The treatment of femoral nonunion is challenging for both the surgeon and the patient. Strut allografts increase the bone stock, enhance fracture healing and increase stability by acting as a biological plate. In this study, we aimed to report the results of the sandwich technique with two-strut allograft in the treatment of oligotrophic or atrophic femoral nonunions.

METHODS

Medical records of the patients who were treated due to femoral nonunion in a single center were retrospectively reviewed. Twenty-one patients (10 males, 11 females) with a mean age of 49 (range: 21 to 79) years were included in the study. The left side was affected in 11 patients, whereas the right side was affected in ten. The patients had 11 femoral shaft fractures, seven proximal femoral fractures and three distal femoral fractures. The mean time from the previous operation to the nonunion surgery was 9.6 (range: 6 to 22) months.

RESULTS

Union was achieved in all patients after a mean period of 6.2 (range: 4 to 10) months. The mean follow-up time was 46.8 (range: 12 to 86) months. One patient had superficial surgical site infection in the autologous graft donor site.

CONCLUSION

The sandwich technique with two-strut allograft provides good results in the treatment of femoral nonunion. The technique can be used on any type of nonunion, at any segment of the femur and can be combined with different fixation techniques.

Management of neglected distal femur epiphyseal fracture-separation

INTRODUCTION

Neglected epiphyseal fracture-separations of the distal femur are rare. Still reported in developing countries, they lead to therapeutic issues. The objective of the study is to describe their characteristics and to propose treatment options.

MATERIALS AND METHODS

Ten years of ongoing study was held in our orthopedics department. All patients with a neglected epiphyseal fracture-separations of the distal femur after a knee trauma were included in the study. Pre-operative and post-operative data were collected and analyzed.

RESULTS

A total of 13 cases of neglected traumatic epiphyseal fracture-separations of the distal femur were found among 8616 in-patients of the department. It was mainly boys (9M/4F) around 16 years that were received 14 weeks after knee trauma. Most of the injuries were an AO-type 33-E/2.1 (Simple Salter-Harris' type II) (n=12) distal femur malunion (n=10). Associated complications were cutaneous opening (n=7), superficial infection (n=4), deep infection (n=4). Fractures were management surgically (n=12) by an open osteoclasis procedure (n=9), debridement (n=7) and a thigh amputation (n=1). The outcome was better if an open osteoclasis procedure was early performed in closed distal femur mal-union with a complementary rehabilitation program.

CONCLUSION

Specialized trauma care facilities must be increased, and trauma education programs must be undertaken to avoid neglected epiphyseal fracture-separations of the distal femur in developing countries.

Osteoporotic distal femur fractures in the elderly: peculiarities and treatment strategies

Distal femur fractures account for 4-6% of osteoporosis related fractures of the femur in the elderly population. They represent a relevant cause of morbidity and mortality in the geriatric population with a reported 1-year mortality reaching 30%. Non-displaced fractures or even displaced fractures in patients with high operative risk can be treated conservatively. However, operative treatment is the most widely accepted management option for displaced fractures. The advantage resides in early mobilization and weight-bearing, reducing risks related with a prolonged immobilization when compared with conservative treatment. On the other hand, the intrinsic difficulty of fixing an osteoporotic bone is a major concern. The presence of osteosynthesis devices or prosthetic implants in the femur can make the surgical treatment more challenging, sometimes limiting therapeutic options. Aim of the present paper is to review the most recent literature about osteoporotic distal femur fractures in the elderly, including periprosthetic and other hardware related fractures, to highlight current evidence on management options and related results as a guide for the daily clinical practice.

Lower reoperation rate with locking plates compared with conventional plates in Vancouver type C periprosthetic femoral fractures: A register study of 639 cases in Sweden

AIM

To investigate demographics and outcomes of Vancouver type C periprosthetic femoral fractures (PPFF) treated with open reduction and internal fixation.

METHODS

Patient data were obtained from medical charts of cases reported to the Swedish Hip Arthroplasty Register and/or from the National Patient Register. Vancouver type C fractures undergoing surgery between 2001 and 2011, in patients who had received their primary THR between 1979 and 2011, were included. Any further reoperation performed between 2001 and 2013 and related to the PPFF constituted the primary outcome.

RESULTS

A total of 632 patients with 639 Vancouver type C fractures were identified. The majority of the patients were women (84%) and they had a fracture distal to a cemented stem (95%). The mean age at the time of fracture was 72 years. Treatment was performed with a locking plate (363 cases), a conventional plate (184 cases), an intramedullary nail (62 cases), or with double plating (30 cases). The overall reoperation rate was 17%, and mortality within one year of the operation was 16%. Locking plates had a significantly lower reoperation rate than conventional plates (p<0.001) and intramedullary nailing (p = 0.005). Interprosthetic femoral fractures did not have a statistically different outcome compared with non-IPFFs.

CONCLUSIONS

The lowest reoperation rate was observed using locking plates in Vancouver type C fractures when compared with conventional plates or intramedullary nailing. The presence of an ipsilateral knee prosthesis did not influence the outcome of the surgical treatment.

Retrograde Intramedullary Nail Fixation for Derotational Femoral Osteotomy for Recurrent Femoropatellar Instability

Axial alignment of the femur and tibia is often misdiagnosed in patients with patellofemoral stability problems. Femoral torsion is critical for patellofemoral biomechanics, so it must be evaluated in every patient before the plan of surgery is decided. This case describes a femoral derotational osteotomy due to excessive internal torsion of the femur fixed with a retrograde femoral nail. This type of fixation provides a biomechanical advantage compared to plates. At the two-year follow-up, the patient achieved excellent results, reaching a functional score of 91 points on the Lysholm scale. Derotational femoral osteotomy should be considered in patellofemoral pathology, and a retrograde femoral nail is a valid fixation method for this surgery.