Non-union in lateral locked plating for distal femoral fractures: A systematic review

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.

Technical Factors Contributing to Nonunion in Supracondylar Distal Femur Fractures Treated With Lateral Locked Plating: A Risk-Stratified Analysis

OBJECTIVE

To identify technical factors associated with nonunion after operative treatment with lateral locked plating.

METHODS

DESIGN

Retrospective cohort study.

SETTING

Ten Level I trauma centers.

PATIENT SELECTION CRITERIA

Adult patients with supracondylar distal femur fractures (OTA/AO type 33A or C) treated with lateral locked plating from 2010 through 2019.

OUTCOME MEASURES AND COMPARISONS

Surgery for nonunion stratified by risk for nonunion.

RESULTS

The cohort included 615 patients with supracondylar distal femur fractures. The median patient age was 61 years old (interquartile range: 46 -72years) and 375 (61%) were female. Observed were nonunion rates of 2% in a low risk of nonunion group (n = 129), 4% in a medium-risk group (n = 333), and 14% in a high-risk group (n = 153). Varus malreduction with an anatomic lateral distal femoral angle greater than 84 degrees, was associated with double the odds of nonunion compared to those without such varus [odds ratio, 2.1; 95% confidence interval (CI), 1.1-4.2; P = 0.03]. Malreduction by medial translation of the articular block increased the odds of nonunion, with 30% increased odds per 4 mm of medial translation (95% CI, 1.0-1.6; P = 0.03). Working length increased the odds of nonunion in the medium risk group, with an 18% increase in nonunion per 10-mm increase in working length (95% CI, 1.0-1.4; P = 0.01). Increased proximal screw density was protective against nonunion (odds ratio, 0.71; 95% CI, 0.53-0.92; P = 0.02) but yielded lower mRUST scores with each 0.1 increase in screw density associated with a 0.4-point lower mRUST (95% CI, -0.55 to -0.15; P < 0.001). Lateral plate length and type of plate material were not associated with nonunion. ( P > 0.05).

CONCLUSIONS

Malreduction is a surgeon-controlled variable associated with nonunion after lateral locked plating of supracondylar distal femur fractures. Longer working lengths were associated with nonunion, suggesting that bridge plating may be less likely to succeed for longer fractures.

LEVEL OF EVIDENCE

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

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

PURPOSE

The 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.

METHODS

Between 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).

RESULTS

Out 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.

CONCLUSION

While the rate of non-union was higher in the LP group and the functional results were superior in the plating group.

Which fixation produces the best outcome for distal femoral fractures? Meta-analysis and systematic review of retrograde nailing versus distal femoral plating in 2432 patients and 33 studies

PURPOSE

The distal femur comprises a wide intramedullary cavity and thin cortical bone. Firm internal fixation of comminuted fractures with displacement is challenging. Although many comparative studies have reported retrograde intramedullary nailing (RIN) and distal femoral plating (DFP) as the usual fixation methods for distal femoral fractures, no clear conclusion has been reached. Therefore, a meta-analysis and systematic review of the clinical and radiological results were conducted to determine the appropriate treatment method for distal femoral fractures.

METHODS

A systematic search of the PubMed, Embase, Scopus, and Cochrane Library databases from their inception to December 19, 2022, was performed using predefined criteria. Studies comparing the effects of RIN and DFP were considered. The analyzed outcome measures included duration of surgery, blood loss, time to union, delayed union, nonunion, malalignment, implant failure, infection, reoperation, limb length discrepancy, range of motion, persistent anterior knee pain, knee stiffness, and functional scores. Meta-analysis of pooled data was conducted using a random-effects model to determine the standard mean difference (SMD) or odds ratio (OR) with 95% confidence intervals (CIs).

RESULTS

Thirty-three studies with 2,432 patients were included. Compared to DFP, RIN was associated with a shorter time to fracture union (SMD, 1.83 months; 95% CI - 2.76 to - 0.90; P < 0.001) and a lower incidence of postoperative infection (OR 0.54; 95% CI 0.31-0.94; P = 0.03). Pooled analysis revealed no significant differences in other outcome measures between the two treatment modalities.

CONCLUSION

In distal femoral fractures, RIN had a shorter bone union time and was more resistant to infection than DFP. However, there were no significant differences in the other clinical parameters. Therefore, the characteristics, strengths, and weaknesses of RIN and DFP should be carefully identified, and appropriate treatment should be provided based on the patient's medical condition and fracture pattern.

Timing of Complications Following Surgery for Distal Femur Fractures in Older Adults

Introduction

The purpose of this study was to identify the timing and nature of complications associated with distal femur fracture surgery in patients aged 65 and older using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database.

Methods

The ACS NSQIP database was queried for adults aged 65 and older who received surgical treatment for a distal femur fracture between 01 January 2015 and 31 December 2021. Cox regression models and risk tables adjusted for baseline clinical characteristics were created for 14 complications (Superficial Surgical Site Infection (SSI), Deep SSI, Organ/Space SSI, Pneumonia, Pulmonary Embolism (PE), Deep Venous Thrombosis (DVT), Urinary Tract Infection (UTI), Stroke/Cerebrovascular accident (CVA), Myocardial Infarction (MI), Renal Failure, Cardiac Arrest (CA), Re-operation, Sepsis, and Death within 30 days of surgery). Model summaries were used to identify significant variables with a Bonferroni correction applied.

Results

A total of 3956 adults met inclusion criteria and were included in analysis. The most common complications were UTI (5.2%), death (4.1%), and pneumonia (3.4%). Complications typically occurred within 14 days after surgery, except for SSI, which occurred between post-op days 11 and 24.

Conclusions

Distal femur fractures are a substantial source of morbidity and mortality in the older adult population. Our findings underscore the need for comprehensive preoperative risk assessment and patient management strategies to mitigate the impact of identified risk factors in this vulnerable population.

Prediction of fracture nonunion leading to secondary surgery in patients with distal femur fractures

Aims

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures.

Methods

We conducted a retrospective cohort study of adult patients with traumatic distal femur fracture treated with lateral locking plate between 2009 and 2018. The patients who underwent secondary surgery due to fracture healing problem or plate failure were considered having nonunion. Background knowledge of risk factors of distal femur fracture nonunion based on previous literature was used to form an initial set of variables. A logistic regression model was used with previously identified patient- and injury-related variables (age, sex, BMI, diabetes, smoking, periprosthetic fracture, open fracture, trauma energy, fracture zone length, fracture comminution, medial side comminution) in the first analysis and with treatment-related variables (different surgeon-controlled factors, e.g. plate length, screw placement, and proximal fixation) in the second analysis to predict the nonunion leading to secondary surgery in distal femur fractures.

Results

We were able to include 299 fractures in 291 patients. Altogether, 31/299 fractures (10%) developed nonunion. In the first analysis, pseudo-R2 was 0.27 and area under the receiver operating characteristic curve (AUC) was 0.81. BMI was the most important variable in the prediction. In the second analysis, pseudo-R2 was 0.06 and AUC was 0.67. Plate length was the most important variable in the prediction.

Conclusion

The model including patient- and injury-related factors had moderate fit and predictive ability in the prediction of distal femur fracture nonunion leading to secondary surgery. BMI was the most important variable in prediction of nonunion. Surgeon-controlled factors had a minor role in prediction of nonunion.

Resistant distal femoral nonunion treated with combined nail/plate construct and reamer-irrigator-aspirator technique

OBJECTIVE

This study was performed to evaluate the effectiveness of intramedullary nailing and a lateral locking plate combined with the reamer-irrigator-aspirator (RIA) bone grafting technique for resistant distal femoral nonunion.

METHODS

This retrospective observational study was performed from January 2018 to December 2021 and involved five patients who presented with resistant distal femoral nonunion despite undergoing several surgeries. They were treated with intramedullary nailing and a lateral locking plate combined with the RIA bone grafting technique. Postoperative follow-up was performed to observe the healing time, and functional outcomes were evaluated using the Lower Extremity Functional Scale (LEFS).

RESULTS

After the patients had been monitored for a mean of 17.9 months, complete bone healing was observed in every patient (mean healing time of 4.8 months). Postoperative wound failure in an older patient was successfully treated with resuturing and nutritional assistance. At the last follow-up, the mean LEFS score was 71.2/80 and the mean knee flexion was 109 degrees.

CONCLUSIONS

Our study demonstrates that combining intramedullary nailing and a lateral locking plate with the RIA bone grafting technique enhances biological properties, provides good structural support, and achieves good union and functional results in the management of resistant nonunion of the distal femur.

Application of Cortical Bone Plate Allografts Combined with Less Invasive Stabilization System (LISS) Plates in Fixation of Comminuted Distal Femur Fractures

Background and Objectives: At present, the management of comminuted distal femur fractures remains challenging for orthopedic surgeons. The aim of this study is to report a surgical treatment for comminuted distal femur fractures using supplementary medial cortical bone plate allografts in conjunction with the lateral less invasive stabilization system (LISS) plates. Materials and Methods: From January 2009 to January 2014, the records of thirty-three patients who underwent supplementary medial cortical bone plate allografts combined with lateral LISS plates fixation were reviewed. Clinical and radiographic data were collected during regular postoperative follow-up visits. Functional outcomes were determined according to the special surgery knee rating scale (HSS) used at the hospital. Results: Thirty patients were followed for 13 to 73 months after surgery, with an average follow-up time of 31.3 months. The mean time to bone union was 5.4 months (range of 3-12 months) and the mean range of knee flexion was 105.6° (range of 80-130°). Of the remaining patients, 10 had a score of "Excellent", while 10 had a score of "Good". Three patients had superficial or deep infections, one patient had nonunion that required bone grafting, and one patient had post-traumatic knee arthritis. Conclusions: Based on these promising results, we propose that supplementary medial cortical bone plate allografts combined with lateral LISS plate fixation may be a good treatment option for comminuted distal femur fractures. This treatment choice not only resulted in markedly improved stability on the medial side of the femur, but also satisfactory outcomes for distal femoral 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.

Defining the Mean Angle of Diaphyseal Long Bone Nonunions-Does Shear Prevail?

OBJECTIVES

To define the mean angle of a series of diaphyseal nonunions based on radiographic analysis.

DESIGN

A retrospective cohort study.

SETTING

Two level-1 trauma centers.

PATIENTS

One hundred twenty patients presenting with nonunion.

INTERVENTION

A mean nonunion angle was calculated from a series of AP and lateral X-rays using a standardized technique. The nonunion angle was then estimated in a single plane by considering the greater of the 2 measured angles. Additional data collected included patient age, sex, nonunion site, initial fracture angle, and original fracture pattern.

MAIN OUTCOME MEASUREMENT

Single plane nonunion angle.

RESULTS

The mean angles of all nonunion in coronal plane was 42 degrees (SD 17 degrees) and 42 degrees in sagittal plane (SD 18 degrees) and 48 degrees (SD 15 degrees) in single plane. The single plane nonunion angle in fractures which were originally multiplanar was steeper to those occurring in originally single plane fractures (P 0.002) although both were close to 45 degrees. There was no significant difference in the nonunion angles on subgroup analysis of cohort location, sex, or anatomic location.

CONCLUSIONS

This study demonstrates the mean angle of diaphyseal nonunions from long bones of the lower limb approaches 45 degrees. This is noted in all types of fractures and is irrespective of anatomic location or sex. This confirms the hypothesis that shear is likely to play a role in the development of a nonunion. This study provides further evidence that nonunions occur primarily because of mechanical instability.

LEVEL OF EVIDENCE

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

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.

Biphasic plating improves the mechanical performance of locked plating for distal femur fractures

Internal fixation by plate osteosynthesis is the gold standard treatment for distal femur fractures. Despite improvements that preserve the biological conditions for bone healing, there are concerns standard locked plating constructs may be overly stiff. Biphasic plating is a novel concept designed to provide suitable fracture motion and increased implant strength to support early full weight-bearing. This study aims to demonstrate that the Biphasic Plate can be incorporated into a pre-contoured distal femur plate while providing adequate flexibility and increased implant strength. The mechanical performance of the Biphasic Plate (BP) was investigated in comparison to a standard locking plate for the distal femur (LCP-DF). Constructs were formed by mounting the implants on a bone substitute. The construct stiffness and strength under axial loading and the magnitude of interfragmentary movement were determined using finite element analysis. The Biphasic Plate exhibited a bi-linear stiffness response; at low loads, the BP construct was 55% more compliant and at high loads 476% stiffer than the LCP-DF. The Biphasic Plate provided more consistent interfragmentary movement over a wider loading range. At partial weight-bearing loads, the Biphasic Plate produced larger interfragmentary movements (0.18 vs. 0.04 mm). However, at loads equivalent to full weight-bearing, the maximum movements were substantially smaller than the LCP-DF construct (1.5 vs. 3.5 mm). The increased flexibility at low loads was provided without sacrificing implant strength with peak stress in the Biphasic Plate 63% lower than the LCP-DF construct. The biphasic plating concept can be successfully incorporated into anatomically contoured distal femur plates while providing adequate flexibility and increasing implant strength.

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.