Dual plate fixation results in improved union rates in comminuted distal femur fractures compared to single plate fixation

Hinge screw or no hinge stabilization provides decreased stability compared to hinge plate in a biomechanical evaluation of distal femoral derotational osteotomies

PURPOSE

Derotational distal femoral osteotomy (DFO) is the causal treatment for patients with femoral torsional deformity. The fixation is achieved by a unilateral angle-stable plate. Delayed- or non-unions are one of the main risks of the procedure. An additional contralateral fixation may benefit the outcome. Therefore, we hypothesize that primary stability in DFO can be improved by an additional fixation with a hinge screw or an internal plate.

METHODS

Derotational DFO was performed in 15 knees and fixed either with an angle-stable plate only (group 'None'), with an additional lateral screw (group 'Screw') or with an additional lateral plate (group 'Plate'). Biomechanical evaluation was carried out under axial loading of 150 N (partial weight bearing) and 800 N (full weight bearing), followed by internal and external rotation. After linear axial loading in step 1, a cyclic torsional load of 5 Nm was applied under constant axial load in step 2. In step 3, the specimens were unloaded. Micromovements between the distal and proximal parts of the osteotomy were recorded at each step for all specimens.

RESULTS

In step 1, the extent of micromovements was highest in group 'None' and lowest in group 'Plate' without being significantly different. In step 2, group 'Plate' showed significantly higher stability, reflected by less rotation and lower micromovements. Increasing the axial load from 150 to 800 N at step 2 resulted in increased stability in all groups but only reached significance in group 'None'.

CONCLUSION

An additional contralateral plate significantly increased stability in derotational DFO compared to the unilateral angle-stable plate only. Contrary, a contralateral hinge screw did not provide improved stability.

STUDY DESIGN

Experimental study.

LEVEL OF EVIDENCE

IV.

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

INTRODUCTION

Distal femur fractures account for 3-6% of all femur fractures. Internal fixation of most distal femur fractures with an anatomic lateral locking plate should permit some motion at the metaphyseal portion of the fracture when secondary bone healing is planned by the operating surgeon. While several studies have been performed evaluating union rates for distal femur fractures with stainless steel and titanium plates, the timing of callus formation between stainless steel and titanium implants used as bridge plates for distal femur fractures (AO/OTA 33-A and -C) has been investigated to a lesser extent. We hypothesize that callus will be visualized earlier with post-operative radiographs with titanium versus stainless steel bridge plates.

METHODS

We retrospectively reviewed a consecutive cohort of patients over 18 years of age with acute AO/OTA 33-A and 33-C fracture patterns treated with an isolated stainless steel or titanium lateral bridge plate within 4 weeks of injury by a single fellowship-trained orthopedic trauma surgeon from 2011 to 2020 at one academic Level 1 trauma center. An independent, fellowship-trained orthopedic trauma attending surgeon reviewed anterior-posterior (AP) and lateral radiographs from every available post-operative clinic visit and graded them using the Modified Radiographic Score for Tibia (mRUST).

RESULTS

Twenty-five subjects were included in the study with 10 with stainless steel and 15 with titanium plates. There were no significant differences in demographics between both groups, including age, sex, BMI, injury classification, open versus closed, mechanism, and laterality. Statistically significant increased mRUST scores, indicating increased callus formation, were seen on 12-week radiographs (8.4 vs. 11.9, p = 0.02) when titanium bridge plates were used. There were no statistically significant differences in mRUST scores at 6 or 24-weeks, but scores in the titanium group were higher in at every timepoint.

DISCUSSION

In conclusion, we observed greater callus formation at 12 weeks after internal fixation of 33-A and 33-C distal femur fractures treated with titanium locked lateral distal femoral bridge plates compared to stainless steel plates. Our data suggest that titanium metallurgy may have quicker callus formation compared to stainless steel if an isolated, lateral locked bridge plate is chosen for distal femur fracture fixation.

Dual Plating of Distal Femoral Fractures

Background

Dual plating of the distal femur is indicated for the treatment of complex intra-articular fractures, supracondylar femoral fractures, low periprosthetic fractures, and nonunions. The aim of this procedure is anatomical alignment of the articular surface, restoration of the articular block, and prevention of varus collapse.

Description

Following preoperative planning, the patient is positioned supine with the knee flexed at 30°. The lateral incision is made first, with a mid-lateral incision that is in line with the femoral shaft. If intra-articular work is needed this incision can be extended by curving anteriorly over the lateral femoral condyle. Next, the iliotibial band is transected in line with its fibers. The vastus lateralis fascia is incised and elevated off the septum, working distal to proximal. Care should be taken to maintain hemostasis when encountering femoral artery perforating vessels. Once there is adequate exposure, several reduction aids can be utilized, including a bump under the knee, Schanz pins, Kirschner wires, and reduction clamps. A lateral precontoured plate is placed submuscularly, and the most proximal holes are filled percutaneously. The medial incision begins distally at the adductor tubercle and is a straight incision made proximally in line with the femoral shaft. The underlying fascia is transected in line with the skin incision, and the vastus medialis is elevated. Care should be taken to avoid the descending geniculate artery, as well as its articular branch and the muscular branch to the vastus medialis. A lateral tibial plateau plate is contoured and placed.

Alternatives

Nonoperative treatment of distal femoral fractures is rare, but relative indications for nonoperative treatment include frailty of the patient, lack of ambulatory status, a non-reconstructible fracture, or a stable fracture. These patients are placed in a long-leg cast followed by a hinged knee brace1. There are several other surgical fixation options, including lateral plating, retrograde intramedullary nailing, distal femoral replacement, and augmentation of a retrograde nail with a plate.

Rationale

Dual plating has several benefits, depending on the clinical scenario. Biomechanical studies have found that dual plating results in increased stiffness and construct strength2,3. Additional construct stability can be offered through the use of locking plates, particularly in osteoporotic bone. Taken together, this increased stability and construct strength can allow for earlier weight-bearing, which is particularly important for fractures in the geriatric population. Furthermore, the increased stiffness and construct strength make this procedure a favorable treatment option for nonunion, and it has been shown to result in lower rates of postoperative nonunion compared with lateral plating alone4-7. Adjunctive use of a medial plate also has been suggested to prevent varus collapse, particularly with metaphyseal comminution and poor bone quality2,3,8. Finally, in the periprosthetic fracture population, dual plating also removes the concern of incompatibility with a retrograde nail.

Expected Outcomes

The outcomes of dual plating are promising, given the severity of the injury. When comparing operative to nonoperative treatment outcomes, nonoperatively managed patients had worse functional outcomes and higher rates of complications related to immobility1. Dual plating of supracondylar fractures and intra-articular distal femoral fractures yields nonunion rates ranging from 0% to 12.5%, lower than the 18% to 20% reported with lateral locking plates4-7,9-12. This reduction in nonunions has been shown to lead to fewer revisions when compared with single-plating techniques7. In prior studies, 95% of nonunions treated with the dual-plating technique achieved union postoperatively11. One concern when utilizing the medial approach is critical damage to medial vascularity; however, this result has not been reported in the literature, and there is a safe operating window13. Despite the benefits of dual plating, there are relatively high rates of infection following dual plating (0% to 16.7%) compared with lateral plating alone (3.6% to 8.5%)5,14-17. However, many of these studies are small case series, highlighting that a surgeon's comfort and skill with these procedures is paramount to patient outcomes.

Important Tips

Meticulous placement and contouring of lateral and medial plates are required to prevent malreduction of the articular block that creates a "golf-club deformity."18,19During the medial approach, be aware of descending geniculate artery-particularly its muscular branch, which is ∼5 cm from the adductor tubercle/medial epicondyle, and its root, which enters the compartment at the adductor hiatus at ∼16 cm13.

Comparison of radiological and functional results in osteoporotic distal femur fractures operated with single plating, lateral incision, and double plating, anterior paramedial incision: A retrospective study

Treatment of osteoporotic distal femur fractures is often complicated by a high rate of nonunion and varus collapse. For such fractures, lateral plating with lateral incision and double plating with anterior paramedial incision have shown promising results in the recent literature. The hypothesis of this study was that bilateral plating of comminuted distal femur fractures in osteoporotic patients would result in higher union rates and lower revision rates compared to an isolated lateral locking plate. The study included 56 patients (23 males, 33 females) with supracondylar femur fracture. According to the OA/OTA classification, 9 were type A3, 8 were A2, 13 were C1, 16 were C2, and 10 were C3. The mean follow-up period was 12 months, with 29 patients treated using lateral mini-incision, lateral locking plate, and 27 patients treated with anterior paramedial incision, dual plating. The clinical and radiological results were evaluated. The mean duration of radiological union in the studied population was 15 ± 2.1 months (range, 11-21 months) in the single plate group (Group A), and 13.5 ± 2.6 months (range, 9-19 months) in the double plate group (Group B). Mean ROM was 112.3° and flexion contracture 4° in Group A, and ROM 108.3° and flexion contracture 6.7° in Group B. (P = .15). The average Western Ontario and McMaster Universities Arthritis Index (WOMAC) score was 85.6 points in Group A and 83.5 points in Group B (P = .2278). The postoperative anteversion measurement in the operated extremity ranged from -15 to 19 in Group A, and from 5 to 18 in Group B. When the anteversion degrees were compared between the injured and uninjured extremities in the postoperative period, a significant difference was observed within Group A (P = .0018), but no significant difference was observed in Group B (P = .2492). Dual plate fixation using the anterior paramedial approach is an effective operative method for osteoporotic distal femur fractures. This has many advantages such as precise exposure, easy manipulation, anatomic reduction, and stable fixation. However, for surgical indications and medial bone defects > 1 cm, grafting should be performed.

Plate fixation optimization for distal femoral fractures with segmental bone loss: Defining the preferred screw distribution using finite element analysis

OBJECTIVES

Distal femur fractures can exhibit extensive comminution, and open fractures may result in bone loss. These injuries are under high mechanical demands when stabilized with a lateral locked plate (LLP), and are at risk of non-union or implant failure. This study investigates the optimal LLP screw configuration for distal femur fractures with a large metadiaphyseal gap of 5 cm.

METHODS

A finite element (FE) model, validated against experimentally measured strains and displacement, evaluated pull-out forces and stress concentration on typical implants under clinical conditions corresponding with the 10 % point during the stance phase of the gait cycle.

RESULTS

Maximum stress was up to 83 % less when the ratio (Cp) between the proximal screw-distribution-length and the distance of the first screw to the fracture was less than 0.2; maximum pull-out force was 99 % less when this ratio was higher than 0.4.

CONCLUSIONS

Screw configuration based on either normal or osteopenic bone quality plays an important role in determining the risk of construct failure for a major (50 mm) distal femoral metadiaphyseal segmental defect. This study provides valuable information when planning definitive fixation for distal femur fractures with extensive comminution or segmental bone defects, to mitigate the risk of implant failure and subsequent nonunion.

A 3D-printed load sharing implant achieved union of a 9-cm femoral segmental bone defect within three months using a hybrid Masquelet induction membrane technique. A case-report

Case

A 30-year-old male was admitted in our hospital having an open left distal femoral fracture with 9-cm segmental bone defect and a closed proximal left tibial fracture. He was treated successfully using a Hybrid (Titanium Cage and Bone Graft) Masquelet Induction Membrane Technique (MIMT). His femoral fracture united 3-months post - operatively. The left tibia was treated initially with two locking plates. Following infection, a 3-cm tibial bone gap was treated with external fixation and conventional MIMT. The tibial fracture united 12-months post- operatively.

Conclusion

The Hybrid MIMT achieved a successful healing outcome in this challenging case.

Supplementary medial plating in revision surgery for distal femoral fractures: A surgical technique with clinical outcomes

INTRODUCTION

Distal femur fractures (DFF) are common, especially in the elderly and high energy trauma patients. Lateral locked osteosynthesis constructs have been widely used, however non-union and implant failures are not uncommon. Recent literature advocates for the liberal use of supplemental medial plating to augment lateral locked constructs. However, there is a lack of proprietary medial plate options, with some authors supporting the use of repurposing expensive anatomic pre-contoured plates. The aim of this study was to investigate the feasibility of an effective, readily available medial implant option.

METHODS

A retrospective analysis from January 2014 to August 2023 was performed on DFF requiring revision open reduction internal fixation (rORIF) with supplemental medial plating with a Large Fragment Locking Compression Plate (LCP) T-Plate via a medial sub-vastus approach. The T-plate was contoured and placed superior to the medial condyle. A combination of 4.5 mm cortical, 5 mm locking and/or 6.5 mm cancellous screws were used, with oblique screw trajectories towards the distal lateral cortex of the lateral condyle. The primary outcome was union rate.

RESULTS

This technique was utilised on fifteen patients. The mean age was 55±15 (range 23-81); 73 % of cases were male and the median follow-up was 61 weeks (IQR 49-87). The two most common fracture patterns were AO/OTA 33-C3 (n = 5) and 33-A3 (n = 4), and three patients had open fractures. The union rate was 93 % (14/15), with a median time to union of 29 weeks (IQR 18-49). There were two complications: a deep infection requiring two debridements and locally eluding antibiotic insertion, and a prominent screw requiring removal; both patients achieved union. The median range of motion was 0° (IQR 0-5) of extension and 100° (IQR 90-120) of flexion.

CONCLUSION

Supplemental medial plating of DFF with a Large Fragment LCP T-Plate is a feasible, safe, and economical option for rORIF. Further validation on a larger scale is warranted, along with considerations to developing a specific implant in line with these principles.

Finite element analysis of 3 internal fixations for distal type C3 femur fractures with medial wall bone defects

OBJECTIVES

Managing 33-C3 femur fractures with medial wall bone defects poses a significant challenge for orthopedic surgeons. The gold standard treatment for arbeitsgemeinschaftfür osteosynthesefragen (AO)/orthopedic trauma association (OTA) 33-C3 distal femur fractures with medial wall bone defects remains elusive. This study employs finite element analysis to compare the stability and mechanical behavior of 3 internal fixation patterns (single lateral distal locking plate, retrograde intramedullary nail, and dual plates) for 33-C3 femur fractures with medial wall bone defects. The aim is to provide a theoretical basis for the selection of internal fixation modalities in clinical practice.

METHODS

Enrollment included a 43-year-old male volunteer weighing 60 kg, without a history of femur fracture. Bilateral femur normality was verified through X-ray and CT scan assessments. A finite element simulation model of AO/OTA 33-C3 distal femur fracture with medial wall bone defect was established. Three fixation methods, named single lateral locking plate (single-plate group), retrograde intramedullary nail (retrograde intramedullary nail group), and dual plates (dual-plate group), were evaluated using finite element analysis under an axial load of 300 N. The assessment included an examination of von Mises stress distribution, shear stress, and displacement patterns at the internal fixation and femur fracture sites.

RESULTS

The finite element analysis revealed that dual-plate fixation effectively reduced the concentration of von Mises stress at the plate on the fracture site. Under full weight-bearing conditions, the maximum von Mises stress in the implants occurred at the distal femur defect level, with values of 149.30, 59.281, and 58.03 MPa for single-plate fixation, retrograde intramedullary nail, and dual-plate fixation methods, respectively. Similarly, the maximum shear stress in the implants was 77.867, 30.136, and 33.505 MPa for single-plate fixation, retrograde intramedullary nail, and dual-plate fixation methods, respectively, all presenting at the distal femur defect level. The maximum relative displacements of implants during compressive loading were 1.34, 1.25, and 0.83 mm for the single-plate , retrograde intramedullary nail, and dual-plate groups, respectively. Consistently, the maximum loading-point displacements of fracture sites were 1.529, 1.264, and 0.880 mm for the single-plate fixation group, retrograde intramedullary nail group, and dual-plate fixation group, respectively. Furthermore, at the distal femur defect level, the maximum von Mises stress was 72.682, 112.430, and 40.716 MPa for the single-plate, retrograde intramedullary nail, and dual-plate fixation groups, respectively.

CONCLUSIONS

Dual-plate fixation demonstrates superior biomechanical outcomes and exhibites the lowest maximum von Mises stress and shear stress, along with minimal relative movements between fracture fragments. This configuration offers optimal mechanical stability for managing AO/OTA 33-C3 distal femur fractures with medial wall bone defects. Consequently, dual-plate fixation emerges as a better treatment strategy for patients presenting with comminuted intra-articular distal femur fractures accompanied by medial wall bone defects.

Is augmented femoral lateral plating with helically shaped medial plates biomechanically advantageous over straight medial plates?

Dual plating of comminuted distal femoral fractures allows for early patient mobilization. An additional helically shaped medial plate avoids the medial vital structures of the thigh. The aim of this study is to investigate the biomechanical competence of an augmented lateral locking compression plate distal femur (LCP-DF) using an additional straight versus a helically shaped medial LCP of the same length. Ten pairs of human cadaveric femora were instrumented with a lateral anatomical 15-hole LCP-DF. Following, they were pairwise instrumented with either an additional medial straight 14-hole LCP (group 1) or a 90°-helical shape LCP (group 2). All specimens were biomechanically tested under quasi-static and progressively increasing combined cyclic axial and torsional loading until failure. Initial interfragmentary axial displacement and flexion under static compression were significantly smaller in group 1 (0.11 ± 0.12 mm and 0.21 ± 0.10°) versus group 2 (0.31 ± 0.14 mm and 0.68 ± 0.16°), p ≤ 0.007. Initial varus deformation under static compression remained not significantly different between group 1 (0.57 ± 0.23°) and group 2 (0.75 ± 0.34°), p = 0.085. Flexion movements during dynamic loading were significantly bigger in group 2 (2.51 ± 0.54°) versus group 1 (1.63 ± 1.28°), p = 0.015; however, no significant differences were observed in terms of varus, internal rotation, and axial and shear displacements between the groups, p ≥ 0.204. Cycles to failure and load at failure were higher in group 2 (25,172 ± 6376 and 3017 ± 638 N) compared to group 1 (22,277 ± 4576 and 2728 ± 458 N) with no significant differences between them, p = 0.195. From a biomechanical perspective, helical double plating may be considered a useful alternative to straight double plating, demonstrating ameliorated damping capacities during flexion deformation and safer application as the medial neurovascular structures of the thigh are avoided.

The double-plate fixation technique prevents varus collapse in AO type C3 supra-intercondylar fracture of the distal femur

INTRODUCTION

Varus collapse followed by osteosynthesis for distal femoral fractures with conventional implants has been well documented but is seldom mentioned in fractures managed with locking plates. The purpose of this study was to assess the incidence of varus collapse after treating complex supra-intercondylar fractures of the distal femur (AO type C3) using a Single Plate (SP) or Double Plate (DP) fixation technique.

MATERIALS AND METHODS

We retrospectively reviewed 357 patients with distal femoral fractures who were treated at our hospital between 2006 and 2017. After excluding cases of infection, malignancy, periprosthetic fracture, revision surgery, pediatric fracture, and extra-articular fracture, 54 patients were included in the study. All demographic data and radiological and clinical outcomes were reviewed and analyzed.

RESULTS

There were 54 patients enrolled into this study with age from 15 to 85 years old (mean 41.6, SD = 19.9), and 32 of them were open fractures (59%). The patients were further divided into either an SP (n = 15) or a DP group (n = 39). Demographics, including age, sex, injury severity score, and open fracture type, were all compatible between the two groups. The overall nonunion rate was 25.9% (n = 14; 6 from the SP and 8 from the DP group; p = 0.175). The varus collapse rate was 9.3% (n = 5; 4 from the SP and 1 from the DP group (p = 0.018).

CONCLUSIONS

The varus collapse rate after osteosynthesis with a single lateral locking plate could be as high as 26.7% in AO type C3 fractures of the distal femur, which would be decreased to 2.6% by adding a medial buttress plate. Surgeons should consider DP fixation to avoid varus collapse in severely comminuted complete intra-articular fractures of the distal femur.

Three-dimensional computed tomography mapping techniques in the morphometric analysis of AO/OTA 33A and 33C distal femoral fractures: a retrospective single-center study

Purpose: Complex distal femoral fractures involve a challenging set of considerations that must be known to provide optimal management. This study aimed to determine the location and frequency of fracture lines and comminution zones in AO/OTA types 33A and 33C distal femoral fractures using three-dimensional computed tomography mapping. Methods: Seventy-four consecutive eligible patients were included. Fracture fragments for each patient were reconstructed, virtually reduced, and adjusted to match the distal femoral template. Then, all fracture lines and comminuted areas were extracted in transparent mode, and corresponding heat maps were constructed. Finally, these maps, along with the quantitative analysis findings of the counts and volumes of each fragment, were used to summarize the characteristics of the fractures. Results: Thirty-four females and 40 males [average age, 58 years (range, 18-92 years)] presented with a distal femoral fracture. There were 53 AO/OTA type 33A fractures, and 21 AO/OTA type 33C fractures. These two patterns differed significantly on fracture fragment count, comminuted zone fracture fragment count, and mean comminuted zone fracture fragment volume (p < 0.05). Most of the fracture line heat zones were in the femoral epiphysis, intercondylar notch of the femur, and patellofemoral joint. The comminuted area heat regions were mostly found on the lateral, anterior, and posterior femoral diaphysis, with less involvement on the medial side. Conclusion: Our findings may serve as a guide for the surgical approach selection of complex distal femur fractures, the placement strategy of the internal fixation, and the optimization of the osteotomy plan for biomechanical studies.

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.

Risk Factors for Reoperation to Promote Union in 1111 Distal Femur Fractures

OBJECTIVES

To identify modifiable and nonmodifiable risk factors for reoperation to promote union after distal femur fracture.

DESIGN

Multicenter retrospective cohort study.

SETTING

Ten Level-I trauma centers.

PATIENTS/PARTICIPANTS

Patients with OTA/AO 33A or C distal femur fractures (n = 1111).

INTERVENTION

Surgical fixation of distal femur fracture. Fixation constructs were classified as lateral plate, dual plate, nail, or nail plate combination.

MAIN OUTCOME MEASUREMENTS

The outcome of interest was unplanned reoperation to promote union.

RESULTS

There was an 11% (121/1111) rate of unplanned reoperation to promote union. In the multivariate analysis, predictive factors included body mass index [odds ratio (OR) = 1.18; 95% confidence interval (CI), 1.06-1.32; P < 0.01], intra-articular fracture (OR = 1.57; 95% CI, 1.01-2.45; P = 0.04), type III open injury (OR = 2.29; 95% CI, 1.41-3.72; P < 0.01), the presence of medial comminution (OR = 1.85; 95% CI, 1.14-3.06; P = 0.01), and medial translation on postoperative radiographs (OR = 1.23 per one 10th of condylar width; 95% CI, 1.01-1.48; P = 0.03). Construct type was not significantly predictive.

CONCLUSIONS

Eleven percent of distal femur fractures underwent unplanned reoperation to promote union. Body mass index, intra-articular fracture, type III open injury, medial comminution, and medial translation on postoperative radiographs were predictive factors. Construct type was not associated with unplanned reoperation; however, this conclusion was limited by small numbers in the dual plate and nail plate groups.

LEVEL OF EVIDENCE

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

Technical Trick: Supplemental Medial Column Screw Fixation of Distal Femur Fractures Treated With a Laterally Based Locked Plate

SUMMARY

Given known failure rates after lateral plating of distal femur fractures, there is an increasing interest in augmenting fixation to improve outcomes. The addition of medial plates or intramedullary nails have been described with promising results, decreasing nonunion and varus collapse rates. However, the use of dual implants increases implant costs, adds surgical complexity, and requires a second surgical approach that may increase morbidity. A supplemental, percutaneously placed, medial column screw may provide a less invasive means of improving stability and achieving fracture union compared with lateral plating alone.

Medial and lateral dual plating of native distal femur fractures: a systematic literature review

Introduction

Lateral locked plating (LLP) development has improved outcomes for distal femur fractures. However, there is still a modest rate of nonunion in fractures treated with LLP alone, with higher nonunion risk in high-energy fractures, intra-articular involvement, poor bone quality, severe comminution, or bone loss. Several recent studies have demonstrated both the safety and the biomechanical advantage of dual medial and lateral plating (DP). The purpose of this study was to evaluate the clinical outcomes of DP for native distal femoral fractures by performing a systematic review of the literature.

Methods

Studies reporting clinical outcomes for DP of native distal femur fractures were identified and systematically reviewed. Publications without full-text manuscripts, those solely involving periprosthetic fractures, or fractures other than distal femur fractures were excluded. Fracture type, mean follow-up, open versus closed fracture, number of bone grafting procedures, nonunion, reoperation rates, and complication data were collected. Methodologic study quality was assessed using the Coleman methodology score.

Results

The initial electronic review and reverse inclusion protocol identified 1484 publications. After removal of duplicates and abstract review to exclude studies that did not discuss clinical treatment of femur fractures with dual plating, 101 potential manuscripts were identified and manually reviewed. After final review, 12 studies were included in this study. There were 199 fractures with average follow-up time of 13.72 months. Unplanned reoperations and nonunion occurred in 19 (8.5%) and 9 (4.5%) cases, respectively. The most frequently reported complications were superficial infection (n = 6, 3%) and deep infection (n = 5, 2.5%) postoperatively. Other complications included delayed union (n = 6, 3%) not requiring additional surgical treatment and knee stiffness in four patients (2%) necessitating manipulation under anesthesia or lysis of adhesions. The average Coleman score was 50.5 (range 13.5-72), suggesting that included studies were of moderate-to-poor quality.

Conclusions

Clinical research interest in DP of distal femoral fractures has markedly increased in the past few decades. The current data suggest that DP of native distal femoral fractures is associated with favorable nonunion and reoperation rates compared with previously published rates associated with LLP alone. In the current review, DP of distal femoral fractures was associated with acceptable rates of complications and generally good functional outcomes. More high-quality, directly comparable research is necessary to validate the conclusions of this review.

Novel classification system for periprosthetic distal femoral fractures: a consideration for comminution

PURPOSE

Comminution is an aspect of periprosthetic distal femoral fractures (PDFFs) that can influence postoperative outcomes and treatment selection, but is not included in current classification systems. We propose a new classification system for PDFFs based on comminution and cortical reads. This study aims to prove its reliability and efficacy to predict fracture severity and guide treatment.

METHODS

A retrospective chart review of patients treated with single or dual locking plates for PDFFs was performed. Two fellowship-trained orthopedic joint reconstruction specialists used available imaging to classify each PDFF as either type 1 (minimal or no comminution allowing for reconstruction of medial and lateral cortices), type 2 (comminution reasonably allowing for reconstruction of either medial or lateral cortex), and type 3 (extensive comminution not allowing reasonable reconstruction of medial or lateral cortex). Each PDFF was then analyzed for radiographic outcomes including lateral distal femoral angle (LDFA) and the posterior distal femoral angle (PDFA).

RESULTS

Interobserver reliability assessed by Cohen's Kappa statistic was 0.707, and average intraobserver reliability was 0.843, showing substantial reliability. Type 3 PDFFs had greater varus deformity than type 1 (p = 0.0457) or 2 (0.0198).

CONCLUSION

The proposed classification system accounts for comminution, demonstrates strong interobserver and intraobserver reliability, and can be used to guide treatment in regard to single versus dual plating.

LEVEL OF EVIDENCE

Retrospective comparative study, Level IV.

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.

Outcomes of dual plating for unstable distal femoral fractures: a subgroup comparison between periprosthetic and non-periprosthetic fractures

PURPOSE

This study aimed to evaluate the outcomes of dual plating for unstable distal femoral fractures via a subgroup analysis between periprosthetic and non-periprosthetic fractures.

METHODS

This retrospective cohort study analyzed the outcomes of dual plating for unstable distal femoral fractures among 49 consecutive patients (43 women and 6 men) enrolled from July 2008 to August 2020. The patients were divided into periprosthetic (group P, n = 29) and non-periprosthetic (group N, n = 20) groups. The radiographic outcomes included the mechanical lateral distal femoral angle (mLDFA) and union rate based on the computed tomography findings. The clinical parameters included the knee range of motion and knee society score (KSS).

RESULTS

The mean patient age was 71.1 years, and the average follow-up period was 37 months (range, 12-138 months). Union was achieved in 47 patients (96%). The average final mLDFA was 90.5° in group P and 88.3° in group N. The average final knee range of motion was 130° in group P and 107° in group N. The average final KSS was 73.8 in group P and 87.1 in group N.

CONCLUSION

Dual plating for distal femoral fractures yielded an excellent union rate and limb alignment with a low complication rate.

Distal femoral replacement or internal fixation for management of periprosthetic distal femur fractures: A systematic review

BACKGROUND

The number of periprosthetic fractures above a total knee arthroplasty continues to increase. These fractures are associated with a high risk of morbidity and mortality. Techniques for addressing these fractures include open reduction internal fixation (ORIF) and revision arthroplasty, including distal femoral replacement (DFR). The primary aim of this review is to compare mortality and reoperation rates between ORIF and DFR when used to treat periprosthetic distal femur fractures.

METHODS

A systematic review including MEDLINE, Embase and Cochrane Library databases was completed from inception to April 10, 2021. Studies including a comparator cohort were meta-analyzed.

RESULTS

Fourteen studies were identified for inclusion, of which, five had sufficient homogeneity for inclusion in a meta-analysis. 30-day and 2-year mortality was 4.1% and 14.6% in the DFR group. There was no statistically significant difference between ORIF and DFR (log Odds-Ratio (OR) = -0.14, 95 %CI: -0.77 to 0.50). The reoperation rate in the DFR group was 9.3% versus 14.8% for ORIF, with no difference between groups (log OR = 0.10, 95 %CI: -0.59 to 0.79). There was no difference in rates of deep infection (log OR = 0.22, 95 %CI: -0.83 to 1.28). Direct comparison of functional outcomes was not possible, though did not appear significant.

CONCLUSION

DFR in the setting of periprosthetic distal femur fractures is equivalent to ORIF with respect to mortality and reoperation rate and thus a safe and reliable treatment strategy. DFR may be more reliable in complex fracture patterns where the ability to obtain adequate fixation is difficult.

Anatomical analysis of different helical plate designs for distal femoral fracture fixation

PURPOSE

Helical plates potentially avoid the medial neurovascular structures of the thigh. Two implant designs for additional medial 90° helical plate in double plate constructs for geriatric patients and 180° helical plate for single plating in young patients are potential alternatives to widely used standard straight plates.

AIMS

(1) assess the distances to adjacent anatomical structures being at risk when applying medial 90° and 180° helical plates with MIPO technique to the femur, (2) compare these distances with medial straight plates, and (3) correlate measurements performed during surgical dissection with CT angiography.

METHODS

MIPO was performed in ten human cadaveric femoral pairs using either a 90° helical 14-hole LCP (Group 1) or a 180° helical 15-hole LCP-DF (Group 2). Using CT angiography, distances between femoral arteries and plates as well as distances between plates and perforating vessels were evaluated. Following, specimens were dissected and distances determined again. All plates were removed and measurements were repeated with straight medial plates (Group 3).

RESULTS

Overall closest distances between plates and femoral arteries were 14.5 mm (11-19 mm) in Group 1, 21.6 mm (15-24 mm) in Group 2 and 6.5 mm (5-8 mm) in Group 3, with significant differences between Group 3 and both other groups (p < 0.001). Distances to the nearest perforating vessels were 22.4 mm (15-30 mm) in Group 1 and 1.2 mm (1-2 mm) in Group 2. Measurement techniques (visual after surgical disection and CT angiography) demonstrated a strong correlation (p < 0.010).

CONCLUSIONS

Inserting 90° and 180° helical plates with MIPO technique is safe, however, attention must be paid to the medial neurovascular structures with 90° helical plates and to the proximal perforating vessels with 180° helical plates. Helical plates can avoid irritation of medial neurovascular structures - compared with straight plates - although care must be taken during their distal insertion. Measurements during surgical dissection correlate with CT angiography.

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.

Comminuted periprosthetic distal femoral fractures have greater postoperative extension malalignment

INTRODUCTION

Comminution is a significant aspect of periprosthetic distal femoral fracture characterization and may influence post-surgical outcomes. Existing classification systems that guide treatment decisions do not take into account comminution and current literature is unclear on which surgical approach is optimal. We hypothesize that fractures with comminution will have poorer quality post-reduction alignment, especially with a lateral approach.

MATERIALS AND METHODS

37 study patients were identified with billing codes designating a distal femoral periprosthetic fracture. A retrospective chart review was performed to categorize fractures by absence or presence of comminution and medial parapatellar versus lateral surgical approach. These patients underwent an imaging evaluation for the primary outcome of reduction quality including the anatomic lateral distal femoral angle (LDFA) and the posterior distal femoral angle (PDFA). Differences in radiographic outcomes were analyzed with Wilcoxon/Kruskal-Wallis tests, and analysis by approach was through Fisher's exact test.

RESULTS

Patients with comminuted fractures had significantly greater extension of the fragment (PDFA = 95.4° vs 90.0°, p = 0.018) and similar coronal alignment (LDFA = 85.3° vs 86.3°, p = 0.83) of the knee compared to non-comminuted fractures after surgical reduction. This difference was more prominent amongst those treated with a lateral approach (PDFA = 96.1° vs 89.4°, p = 0.032) than with a medial approach (PDFA = 93.7° vs 91.5°, p = 0.41) (Table 1).

DISCUSSION

Current classification systems and treatment guidelines for periprosthetic distal femoral fractures do not adequately address several issues that may influence treatment outcomes, especially comminution. Comminuted fractures had greater post-reduction extension malalignment, falling outside the recommended PDFA range of 87-90°, especially with a lateral approach. Consideration should be given to surgical approach and techniques to reduce excessive extension when treating comminuted periprosthetic distal femoral fractures.

Use of the Locking Attachment Plate for Internal Fixation of Periprosthetic Femur Fractures

Introduction

The locking attachment plate (LAP) can be added to a locking compression plate (LCP) to allow the fixation of locking screws bicortically around a femoral implant. We aimed to examine surgical and fracture characteristics associated with healing for periprosthetic femur fractures (PPFFx) treated with constructs employing LAP fixation. We hypothesize that the addition of an LAP provides stable peri-implant fixation.

Materials &Methods

We retrospectively reviewed a consecutive series of 28 PPFFx surgically treated with LCP-LAP constructs by 4 surgeons from 2015-2020. Fractures were classified and grouped using the Vancouver Classification System and included 12 B1, 2 B2, 11 C fractures, and 3 fractures around other stemmed implants. Primary outcome measures included hardware failure such as screw pullout, broken screws, and plate fracture. Clinical complications including infection, non-union, malunion, and reoperation were recorded.

Results

No LAP failures, screw pullout, or broken screws were observed. Two fractured plates (7.1%) occurred in patients with Vancouver C fracture types. Overall complication rate was 17.9% and included 3 non-unions, 1 deep infection, and 1 implant loosening with painful hardware, each requiring reoperation. Differences were observed between unions and nonunions for total number of screws (12.4 vs 14.7, P = .005) and number of locking screws used (8.04 vs 11.3, P = .03).

Conclusion

The LAP provides adequate fixation and low failure rates where fixation is required around a well-fixed stem. When failures occur, it is from plate breakage and not due to failure of fixation at the area of plate-stem overlap.

New Classification for Periprosthetic Distal Femoral Fractures Based on Locked-Plate Fixation Following Total Knee Arthroplasty: A Multicenter Study

BACKGROUND

This study aimed to establish a new classification using locked-plate fixation for periprosthetic distal femoral fracture (PDFF) following total knee arthroplasty (TKA) and to determine when dual locked-plate fixation is necessary through defining this classification.

METHODS

One-hundred fifteen consecutive PDFFs that underwent operative treatment were reviewed from 2011 to 2019 with minimum 1-year follow-up. Most PDFFs were fixed with single or dual locked-plate fixations using the minimally invasive plate osteosynthesis technique. Based on preoperative radiographs, PDFFs were classified according to the level of main fracture line relative to the anterior flange of femoral component: type I and II, main fracture line located proximal and distal to the anterior flange; and type III, component instability regardless of fracture line requiring revisional TKA. Furthermore, type II fractures were subclassified based on the direction of fracture beak as follows: type II_L, lateral-beak; type II_M, medial-beak. The incidence, treatment methods, and complications were analyzed according to the classification.

RESULTS

Incidences of type I, II_L, II_M, and III were 64.4%, 8.7%, 24.3%, and 2.6%, respectively. Meanwhile, most PDFFs in type I and II were treated with lateral single locked-plate fixations, except for type II_M, which was treated with either single or dual locked-plate fixations. Overall complications were significantly higher in type II (28.9%) than in type I (10.8%, P = .019). In type II_M, bone union-related complications were significantly higher in single locked-plate fixation (50.0%) than in dual locked-plate fixation (5.6%; P = .013).

CONCLUSION

The new classification provides practical and obvious strategies for the treatment of PDFF following TKA using locked-plate fixation. For type II_M fracture, dual plate fixation is necessary to prevent fixation failure or nonunion.

Double fixation for complex distal femoral fractures

For complex distal femoral fractures, a single lateral locking compression plate or retrograde intramedullary nail may not achieve a stable environment for fracture healing.

Various types of double fixation constructs have been featured in the current literature. Double-plate construct and nail-and-plate construct are two common double fixation constructs for distal femoral fractures.

Double fixation constructs have been featured in studies on comminuted distal femoral fractures, distal femoral fracture with medial bone defects, periprosthetic fractures, and distal femoral non-union.

A number of case series reported a generally high union rate and satisfactory functional outcomes for double fixation of distal femoral fractures.

In this review, we present the state of the art of double fixation constructs for distal femoral fractures with a focus on double-plate and plate-and-nail constructs.

Dual-Plating in Distal Femur Fracture: A Systematic Review and Limited Meta-analysis

INTRODUCTION

Although lateral locking plate has shown promising results in distal femur fracture, there are high rates of varus collapse and implant failure in comminuted metaphyseal and articular fractures. This systematic review evaluates the functional outcomes and complications of dual plating in the distal femur fracture.

MATERIALS AND METHODS

Manual and electronic search of databases (PubMed, Medline Embase and Cochrane Central Register of Controlled Trials) was performed to retrieve studies on dual plate fixation in the distal femur fracture. Of the retrieved 925 articles, 12 were included after screening.

RESULTS

There were one randomized-controlled, four prospective and seven retrospective studies. A total of 287 patients with 292 knees were evaluated (dual plating 213, single plating 76, lost to follow-up 3). The nonunion and delayed union rates following dual plate fixations were up to 12.5% and 33.3%, respectively. The mean healing time ranged from 11 weeks to 18 months. Good to excellent outcome was observed in 55-75% patients. There was no difference between the single plate and dual plate fixation with regards to the functional outcomes (VAS score, Neer Score and Kolmert's standard) and complications. Pooled analysis of the studies revealed a longer surgical duration (MD - 16.84, 95% CI - 25.34, - 8.35, p = 0.0001) and faster healing (MD 5.43, 95% CI 2.60, 8.26, p = 0.0002) in the double plate fixation group, but there was no difference in nonunion rate (9.2% vs. 0%, OR 4.95, p = 0.13) and blood loss (MD - 9.86, 95% CI - 44.97, 25.26, p = 0.58).

CONCLUSION

Dual plating leads to a satisfactory union in the comminuted metaphyseal and articular fractures of the distal femur. There is no difference between the single plate and dual plate with regards to nonunion rate, blood loss, functional outcomes and complications. However, dual fixation leads to faster fracture healing at the cost of a longer surgical duration.

Finite element analysis of different medial fixation strategies in double-plate osteosynthesis for AO type 33-C2 fractures

OBJECTIVES

In this study, we evaluated the biomechanical characteristics of different locations of medial fixation strategies in double-plate osteosynthesis for fixing AO/ASIF type 33-C2 fractures by means of finite element analysis.

METHODS

We used 3-matic software and UG-NX software to construct AO/ASIF type 33-C2 fractures and lateral less invasive stabilization system (LISS) plates, medial plates (MPs), and medial support pads (MSPs), respectively. Then, the LISS, MP and MSP were assembled into the fracture model separately to form three fixation models: MSP+LISS, anteromedial plate (AMP+LISS), and MP+LISS. In the next procedure, we performed finite element analysis using ANSYS software after meshing the elements of the models in HyperMesh 11.0 software. Loading conditions including lateral-medial four-point bending, anterior-posterior four-point bending, axial loading, and torsional loading were applied to evaluate the biomechanical advantages among the three fixation types. We observed the peak Von Mises Stress (VMS) value, maximum displacement, bending angle in the coronal plane of the fracture, and torsional angle of the fracture to assess the degree of plate deformation and fixation stability.

RESULTS

Our results showed that in both lateral-medial four-point bending and anterior-posterior four-point bending, the calculations of MP+LISS were marginally better than those of AMP+LISS. However, with the action of axial loading and torsional loading, the deformation of MP+LISS was distinctly smaller than that of AMP+LISS, and the fixation stability of MP+LISS was also prominently better. Under lateral-medial four-point bending, the VMS on the lateral plate of MSP+LISS (59.977 MPa) was approximately half of the two double-plate models. Under anterior and posterior four-point bending, the 38.209 MPa peak VMS of MSP+LISS was still superior to the other two double-plate models. Under torsional loading, the peak VMS (347.75 MPa), the maximum torsional angle of the femoral head (7.852 °), and the torsional angle of fracture (0.036 °) of MSP+LISS preceded those of the other two models. However, under axial loading, the peak VMS (76.376 MPa) and the maximum displacement (3.1798 mm) of MSP+LISS were slightly higher than those of MP+LISS.

CONCLUSION

The MSP+LISS model showed better biomechanical performance than the double-plate models, which might be an effective solution for the treatment of comminuted distal femur fractures.

Biomechanical analysis of the role of hinge support fixators on hinge stability in medial closing wedge distal femoral osteotomy

BACKGROUND

This study aimed to examine the hinge-stabilizing biomechanical effects of hinge support fixators, applied for lateral hinge fractures sustained following distal femoral osteotomy.

METHODS

Medial closing wedge distal femoral osteotomy was performed using a locking plate on 10 cadaveric limbs. The limbs were divided into two groups: the non-fracture group and the lateral hinge fracture group. A cyclic axial load of 400 N was applied to the knee to keep it extended and flexed at 45°. The hinge-stabilizing effects of adding a screw or a short support plate to the lateral fracture site were examined by measuring the translation and rotational angles of the anterodistal and posterodistal hinge positions as well as the surface strains of the medial locking plate.

FINDINGS

Translation and rotation in the fracture group were significantly more pronounced than in the non-fracture group, at the anterodistal and posterodistal positions. Translations at both positions were significantly reduced, by adding the support plate, during both extension and 45-degree flexion in the fracture group. The rotation at the posterodistal position upon extension and the anterodistal position upon 45-degree flexion was significantly reduced by the support plate. The surface strain of the medial plate in the fracture group was significantly reduced by the support plate upon both extension and 45-degree flexion.

INTERPRETATION

Lateral hinge fractures caused abnormal hinge movements, which were significantly reduced by the short support plate. A short support plate could be used if a hinge fracture occurs during distal femoral osteotomy, to improve lateral hinge stability.

Union rates and functional outcome of double plating of the femur: systematic review of the literature

BACKGROUND

The optimal treatment strategy for the surgical management of femur fractures and non-unions remains unknown. The aim of this study is to assess union rates, complications and outcome after femoral double plating. Treatment of shaft, distal, periprosthetic fractures and pathological proximal femur fractures as well as femoral non-unions with double plating were evaluated.

METHODS

A systematic review according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was conducted. Published literature reporting on the treatment and clinical outcome of femoral fractures and non-unions with double plating was identified. In total, 24 studies with 436 cases of double plating, 64 cases of single plating, 84 cases of intramedullary nailing (IM), and 1 interfragmentary screw treatment met the inclusion criteria of this systematic review. The evaluated literature was published between 1991 and 2020.

RESULTS

Double plating of femoral fractures achieved high healing rates and few complications were reported. It displayed significantly less intraoperative haemorrhage, shorter surgery time reduced risk of malunion in polytraumatised patients when compared to IM. Fracture healing rate of double-plating distal femoral fractures was 88.0%. However, there were no significant differences regarding fracture healing, complication or functional outcome when compared to single plating. Treatment of periprosthetic fractures with double plating displayed high healing rates (88.5%). Double plating of non-unions achieved excellent osseous union rates (98.5%).

CONCLUSIONS

The literature provides evidence for superior outcomes when using double plating in distal femoral fractures, periprosthetic fractures and femoral non-unions. Some evidence suggests that the use of double plating of femoral fractures in polytraumatised patients may be beneficial over other types of fracture fixation.

LEVEL OF EVIDENCE

IV.

Failure of dual plating in a complex open distal femur fracture as the result of major trauma

A 61-year-old polytrauma patient was admitted with a right distal comminuted metaphyseal femoral fracture with intra-articular extension (Orthopaedic Trauma Association 33C2.3 classification) among other injuries. Due to the high degree of comminution and massive bone loss, this was initially managed with a dual plating open reduction internal fixation. Dual plating has shown to be a superior fixation method than single variable angle locking compression plate (VA-LCP) plating providing greater fixation in metaphyseal bone. Our case reports the failure of dual plating which required removal of metalwork and subsequent fixation using intramedullary nail and plate technique. Failure of dual plating is not well documented in the literature. The most recent radiographs taken 15 months postrevision surgery show that the bone has started to heal with evidence of callus formation.

[Current status and progress of locking plate in the treatment of distal femoral comminuted fracture]

OBJECTIVE

To review the current status and progress of locking plate for the treatment of distal femoral comminuted fractures.

METHODS

The related literature was extensively reviewed to summarize the current status and progress in the treatment of distal femoral comminuted fracture with locking plate from four aspects: the current treatment situation, the shortcomings of locking plate and countermeasures, the progress of locking technology, locking plate and digital orthopedic technology.

RESULTS

Treatment of distal femoral comminuted fractures is challenging. Locking plates, the most commonly used fixation for distal femoral comminuted fractures, still face a high rate of treatment failure. Double plates can improve the mechanical stability of comminuted fractures, but specific quantitative criteria are still lacking for when to choose double plates for fixation. The far cortial locking screw has shown good application value in improving the micro-movement and promoting the growth of callus. The biphasic plating is a development of the traditional locking plate, but needs further clinical examination. As an auxiliary means, digital orthopedic technology shows a good application prospect.

CONCLUSION

The inherent defect of locking plate is a factor that affects the prognosis of distal femoral comminuted fracture. The optimization of locking technology combined with digital orthopedic technology is expected to reduce the failure rate of treatment of distal femoral comminuted fracture.

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.

Treatment of two Asiatic black bears (Ursus thibetanus) with severe injuries and their subsequent release into the wild: a case report

Background

The rehabilitation of injured wildlife and their subsequent release into the wild is a humane act as well as important in wildlife conservation. However, little is known about the animals’ fate after release. Therefore, to address these uncertainties, it is essential to adequately describe how the injured animals were treated and managed before releasing into the wild; moreover, post-release monitoring should also be performed. Herein, we document for the first time the process of rescue, surgery, and rehabilitation of severely injured Asiatic black bears (Ursus thibetanus; endangered species in South Korea) and their fate after returning to the wild.

Case presentation

A six-year-old female (bear-01) and a three-year-old male (bear-02) bears were injured by an illegal snare and collision with a bus, respectively. Bear-01 had broad muscle necrosis and ruptures from the snared ankle on the right thoracic limb, with myiasis, and elbow disarticulation was performed. In bear-02, a non-reducible comminuted fracture of the left humerus was confirmed radiologically, and the operation was performed by using dual plate fixation with hydroxyapatite and recombinant human bone morphogenetic protein-2. The bear-01 and -02 were completely healed approximately 30 and 60 days after surgery, respectively. After that, they underwent rehabilitation for 8 and 25 days, respectively, in an outdoor enclosure similar to their natural habitat. Bear-01 and -02 were released into the wild after 45 and 99 days after surgery, respectively, and their mean daily movement distance during the first 30 days after releasing was 2.9 ± 2.1 and 1.3 ± 1.6 km, respectively. The annual mean 95% Kernel home-range size of bear-01 and bear-02 was 265.8 and 486.9 km², respectively. They hibernated every winter, gained weight, gave birth to cubs (bear-01), were not found to have any abnormalities in the veterinary tests, and were not involved in any conflicts with humans after returning to the wild.

Conclusions

Bears without one leg or those with dual plates could adapt well in their natural habitat, which shows that our surgical and post-operative treatments were effective. Additionally, minimizing human contact and observing/evaluating behavior during the rehabilitation is essential in reducing human-bear conflicts after release.

Incidence of Soft-Tissue Releases, Clinical and Radiological Outcomes of Lateral Parapatellar Approach for Valgus Arthritic Knees: A 4-year Follow-up Study with A Review of Literature

PURPOSE

To analyse the incidence of additional soft tissue releases with the lateral parapatellar approach, and the clinical and radiological outcomes of total knee arthroplasties performed using the lateral parapatellar approach for valgus arthritic knees. A review of the existing literature on valgus arthritic knees undergoing knee replacement was performed and our results compared.

MATERIALS AND METHODS

This is a prospective cohort study of 50 patients operated by this approach. Operation and clinical records were assessed to determine the number and sequence of soft tissue releases. Functional outcome was measured using the Oxford Knee Score. Radiological assessment included measurement of alignment and implant positioning.

RESULTS

46 patients included. Mean follow-up of 4 years. Additional lateral releases were performed in 11 (24%) cases. Mean valgus alignment corrected from 13.1 degrees pre-operatively to 5.7 degrees post-operatively. Oxford Knee Score improved from a mean pre-operative score of 11.9 to a mean post-operative score of 38.3 at final follow-up. Radiographs revealed lateralisation of the tibial component in 4 patients. No immediate or late post-operative wound complications, late instabilities or revisions were observed.

CONCLUSION

Lateral parapatellar approach is highly effective in correcting the valgus deformity with a low incidence of additional soft tissue releases. Medium-term results indicate an excellent functional outcome with no complications.