The safety and feasibility of minimally invasive plate osteosynthesis (MIPO) on the medial side of the femur: A cadaveric injection study

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

Introduction

Lateral locking plates are commonly employed for the fixation of distal femur fractures. However, scenarios involving medial comminution, extremely distal fractures, periprosthetic fractures, or nonunion could necessitate medial augmentation. This study explores the possibility of using lateral distal femoral locking plate systems for medial fixation by employing the contralateral plate.

Methods

This study presents a technical note on the application of lateral distal femur locking systems for medial augmentation in patients as indicated by current literature findings. Postoperative imaging modalities, including radiography and computed tomography (CT), were used to assess the plates' fit to the distal femur. Three cases following the specified technical note are presented.

Results

The various plate systems, all comprising distal femur locking systems, demonstrated adaptability to the medial femur anatomy as confirmed by intraoperative visualization and postoperative radiographs, including two-dimensional and three-dimensional CT scans. It has also been possible to achieve at least 3 independent fixation points regardless of the size of the medial condyle.

Conclusions

Locking distal femoral plates can be a viable option for medial augmentation in indicated cases, achieving anatomical adaptation to the distal femur. This provides robust augmentation without the need for additional instruments beyond those used for the lateral cortex.

Current Concepts in Management of Distal Femur Fractures

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

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.

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.

What Is the Likelihood of Union and Frequency of Complications After Parallel Plating and Supplemental Bone Grafting for Resistant Distal Femoral Nonunions?

BACKGROUND

Management of resistant distal femur nonunions is challenging because patients not only have disability from an unhealed fracture, but also often have a shortened femur, stiff knee, deformities, and bone defects to address during revision surgery. Dual plating of the distal femur in such a setting can maintain stability that allows the nonunion to heal while also addressing bone defects and correcting deformities simultaneously. Dual-plating techniques that have been described lack standardization with regard to the size and type of medial-side implants and configuration of the dual-plate construct.

QUESTIONS/PURPOSES

(1) What proportion of patients achieve radiologic evidence of union after parallel plating of resistant distal femoral nonunions? (2) What improvements in function are achieved with this approach, as assessed by improvements in femoral length discrepancy, knee flexion, and patient-reported outcome scores? (3) What complications are associated with the technique?

METHODS

Between 2017 and 2020, the senior author of this study treated 38 patients with resistant distal femoral nonunions, defined here as nonunions that persisted for more than 12 months since the injury despite a minimum of two previous internal fixation procedures. During the study period, our preferred technique for treating aseptic, resistant distal femoral nonunions was to use dual plates in a parallel configuration augmented with autografts. Of 38 patients, three patients with active signs of infection who underwent resection and reconstruction using bone transport techniques and two patients older than 65 years with deficient distal femur bone stock who underwent endoprosthetic reconstruction were excluded. Of the 33 included patients, 67% (22 of 33) were male. The median age was 40 years (range 20 to 67 years). Nonunion was articular and metaphyseal in 13 patients and metaphyseal only in 20 patients. Our surgical approach was to remove existing implants, perform intraoperative culturing to rule out infection, debride the nonunion, correct the deformity, perform intra-articular and extra-articular lysis of adhesions with quadriceps release, and apply fixation using medial and lateral fixed-angle anatomic locked implants positioned in a parallel configuration. Every attempt to improve length was undertaken, and the defects were filled with autografts. A total of 97% of patients were followed until union occurred (one of 33 was lost to follow-up before union was documented), and 79% (26 of 33) were assessed for functional outcomes at a minimum of 2 years (median 38 months [range 25 to 60 months]) after excluding patients lost to follow-up and those in whom union did not occur after parallel plating. Union was defined as evidence of central trabecular bridging on AP radiographs and posterior cortical bridging on lateral radiographs. These radiologic criteria were defined to overcome difficulties in assessing radiologic healing in patients with lateral and medial plates. With parallel plating, bridging trabecular bone along the posterior cortex on lateral radiographs and the central region on AP radiographs is visualized and can be appreciated and interpreted as evidence of healing in two orthogonal planes. Preoperative and follow-up clinical assessment of knee ROM, the extent of femoral length correction based on calibrated femoral radiographs before and after surgery, and the evaluation of improvement in lower limb function based on the preoperative and follow-up differences in responses to the lower extremity functional scale (LEFS) were studied (the LEFS is scored from 0 to 80, with higher scores representing better function). Complications and secondary surgical procedures to address them were abstracted from a longitudinally maintained trauma database.

RESULTS

Sixty-seven percent (22 of 33) of nonunions showed radiologic healing by 24 weeks, and another 24% (eight of 33) healed by 36 weeks. Six percent (two of 33) did not unite, and one patient was lost to follow-up before union was documented. In the 79% (26 of 33) of patients available for final functional outcome assessment, the median femoral shortening had improved from 2.4 cm (range 0 to 4 cm) to 1.1 cm (range 0 to 2.3 cm; p < 0.001), and the median knee ROM had improved from 70° (range 20° to 110°) to 100° (range 50° to 130°; p = 0.002) after surgery. The median LEFS score improved to 63 (range 41 to 78) compared with 22 (range 15 to 33; p < 0.001) before surgery. Serious complications, including major thromboembolic events, iliac graft site infection, knee stiffness (flexion < 60°), and medial plate impingement necessitating removal, were seen in 30% (10 of 33) of patients. Secondary surgical interventions were performed in 24% (eight of 33) of patients to address procedure-related complications.

CONCLUSION

Based on our findings, a high likelihood of union and improvements in knee and lower limb function can be expected with parallel plating of resistant distal femur nonunions using anatomic locked plates. However, the increased frequency of complications observed in our study suggests the need for improvements in dual-plating techniques and to explore possible alternative fixation methods through larger multicenter comparative studies.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

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

INTRODUCTION

Fixation of distal femur fractures with a lateral pre-contoured locking plate provides stable fixation and is the standard treatment in most cases, allowing early range of motion with a high rate of union. However, in situations, the stability achieved with the lateral plate alone may be insufficient, predisposing to fixation failure. The objective of the study was to compare, in synthetic bone models, the biomechanical behaviour of the fixation with a distal femur lateral pre-contoured locking plate solely and associated with a 3.5 mm proximal humeral locking plate applied upside down or a 4.5 mm helical locking compression plate on the medial side.

MATERIAL AND METHODS

A total of 15 solid synthetic left femur samples were used. A metaphysical defect at the level of the medial cortex was simulated. The samples were randomly distributed into three groups equally. All groups received a 4.5/5.0 mm single lateral 9-hole distal femur lateral pre-contoured locking plate. Group 1 had no supplementary plate. Group 2 received a supplementary 6-hole 3.5 mm proximal humeral locking plate and Group 3 received a supplementary 4.5/5.0 mm helical 14-hole narrow locking compression plate.

RESULTS

Both supplementary plate types used in groups 2 and 3 contributed to increase the apparent stiffness of the construct, but pairwise comparison showed statically significant difference only between group 1 and 3. No significant difference was observed between groups 2 and 3.

CONCLUSION

Both supplementary plates might be considered for improving the fixation in distal femur fracture in selected cases.

Management of segmental defects post open distal femur fracture using a titanium cage combined with the Masquelet technique A single-centre report of 23 cases

INTRODUCTION

The segmental bone defects post open distal femur fracture presents a reconstructive challenge, which often requires extreme solutions. The present study reviewed a new treatment strategy which used a cylindrical titanium mesh cage as an adjunct to the Masquelet technique.

METHODS

We retrospectively reviewed a consecutive series of 23 patients treated for segmental bone defects post open distal femur fracture using a titanium mesh cage combined with the Masquelet technique under a 2-staged protocol in our institution from 2017 to 2021. The study group consisted of 13 men and 10 women with an average age of 44.1 years. The surgical debridement was performed with antibiotic polymethylmethacrylate (PMMA) cement spacer implanted into the bone defect combined with cement-wrapped plate stabilization, or antibiotic beads with vacuum sealing drainage (VSD) to cover the wound. The second stage of the Masquelet technique for bone defect repair began at least 4-6 weeks after the first stage, once all signs of possible infection were eliminated. After the cement spacer was removed, the definitive reconstruction was completed with exchange to a cylindrical titanium mesh cage filled with cancellous autograft within the induced membrane. The bone defect with cage was stabilized with a distal femoral Less Invasive Stabilization System (LISS). The radiological and clinical records of the enrolled patients were retrospectively analyzed.

RESULTS

The mean follow-up was 38.6 months. The average number of operations before the second stage was 1.3. The mean interval between the two stages was 12.7 weeks. The average length of the defect measured 8.3 cm (ranging from 6.1 to 12.4 cm). All the defects filled with autograft within the cage achieved bony union, with a mean healing time of 8.4 months. At the latest follow-up, the mean knee extension measured 6.2° (ranging from 0° to 20°), and the mean flexion measured 101.8° (ranging from 60° to 120°). Complications included two instances of superficial stitch abscess, which eventually healed.

CONCLUSIONS

The use of a titanium cage implanted into an induced membrane in a 2-staged Masquelet protocol could achieve satisfactory clinical outcomes in cases of segmental defects following open distal femur fractures.

Medial helical versus straight lateral plating of distal femoral fractures-a biomechanical comparative study

BACKGROUND

Distal femoral fractures are commonly treated with lateral straight plates. However, the lateral approach may not always be desirable, and 180°-helical plates may be an alternative.

AIM

To investigate the biomechanical competence of 180°-helical plating versus standard straight lateral plating of unstable fractures at the distal femur.

METHODS

Twelve left artificial femora were instrumented with a 15-hole Locking Compression Plate-Distal Femur, using either 180°-helical plates (group 1) or conventional straight lateral plates (group 2). An unstable distal femoral fracture AO/OTA 33-A3.3 was simulated. All specimens were biomechanically tested under quasi-static and progressively increasing combined cyclic axial and torsional loading in internal rotation until failure.

FINDINGS

Initial axial stiffness (N/mm) was significantly higher in group 1 (185.6 ± 50.1) compared to group 2 (56.0 ± 14.4), p < 0.001. Group 1 demonstrated significantly higher initial interfragmentary flexion (°) and significantly lower initial varus/valgus deformation (°) under 500 N static axial compression versus group 2 (2.76 ± 1.02 versus 0.87 ± 0.77 and 4.08 ± 1.49 versus 6.60 ± 0.47), p ≤ 0.005. Shear displacement (mm) under 6 Nm static torsion was significantly higher in group 1 versus group 2 in both internal (1.23 ± 0.28 versus 0.40 ± 0.42) and external (1.21 ± 0.40 versus 0.57 ± 0.33) rotation, p ≤ 0.013. Cycles to failure and failure load (N) (clinical/catastrophic) were significantly higher in group 1 (12,484 ± 2116/13,752 ± 1518 and 1748.4 ± 211.6/1875.2 ± 151.8) compared to group 2 (7853 ± 1262/9727 ± 836 and 1285.3 ± 126.2/1472.7 ± 83.6), p ≤ 0.001.

INTERPRETATION

Although 180°-helical plating using a pre-contoured standard straight lateral plate was associated with higher shear and flexion movements, it demonstrated improved initial axial stability and resistance against varus/valgus deformation compared to straight lateral plating. Moreover, the helical plates were associated with significantly higher endurance to failure. From a biomechanical perspective, 180°-helical plating may be considered as a valuable alternative to standard straight lateral plating of unstable distal femoral fractures.

Navigation of femoral and popliteal artery around the knee with CT angiography: implications for surgical interventions

PURPOSE

Uncertainty about the exact position of the femoral and popliteal arteries in the medial thigh and posterior knee might increase vascular complications in surgical procedures. This study aimed to document femoral and popliteal arteries in the medial thigh and around the knee to assist surgeons in developing safer surgical approaches.

METHODS

The study included 120 patients-180 lower limbs-who underwent CT angiography (CTA) of the lower extremity. The distance from the femoral artery to the anterior border, midsagittal axis, and posterior border of the femur and the popliteal artery to the medial, lateral, and midpoint posterior cortex of the proximal tibia was measured in two- and three-dimensional CTA images.

RESULTS

The femoral artery was found to be on average 236.93 ± 29.61 mm, 195.34 ± 26.12 mm, and 146.28 ± 33.18 mm away from the adductor tubercle at the anterior, midsagittal axis, and posterior borders of the femur, correspondingly. The popliteal artery was to be located on average 5.40 ± 2.50 mm posterior to the midpoint of the plateau tibia at the joint line.

CONCLUSION

Considering the mentioned femoral/popliteal artery distances to the femur and proximal tibia would direct surgeons to the safe zones for more accurate surgical approaches in the medial thigh and around the knee when performing osteotomies, knee arthroplasty, arthroscopy, and trauma surgeries, to reduce possible vascular damages.

LEVEL OF EVIDENCE

IV.

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.

Anatomical analysis of different helical plate designs for proximal humeral shaft fracture fixation

OBJECTIVES

Helical plates are preferably used for proximal humeral shaft fracture fixation and potentially avoid radial nerve irritation.

AIMS

Safety of applying four different long plate designs (straight, 45°-, 90°-helical and ALPS) with MIPO technique as well as assessment and comparison of their distances to adjacent anatomical structures.

METHODS

MIPO was performed in 16 human cadaveric humeri using either a straight (group 1), a 45°-helical (group 2), a 90°-helical (group 3) plate, or an ALPS (group 4). Applying CT angiography, distances between brachial arteries and plates were evaluated. All specimens were dissected and distances to the axillary, radial and musculocutaneous nerve were evaluated.

RESULTS

No specimens demonstrated injuries of the anatomical structures at risk after MIPO with all investigated plate designs. Closest overall distance (mean (range); mm) between each plate and the radial nerve was 1 (1-3) in group 1, 7 (2-11) in group 2, 14 (7-25) in group 3 and 6 (3-8) in group 4. It was significantly bigger in group 3 and significantly smaller in group 1 compared to all other groups, p < 0.001. Closest overall distance between each plate and the musculocutaneous nerve was 16 (8-28) in group 1, 11 (7-18) in group 2, 3 (2-4) in group 3 and 6 (3-8) in group 4. It was significantly bigger in group 1 and significantly smaller in group 3 compared to all other groups, p < 0.001.

CONCLUSIONS

MIPO with 45°- and 90°-helical plates as well as with ALPS is safely feasible and demonstrates significantly bigger distances to the radial nerve compared to straight plates. However, the distances remain small and attention must be paid to the musculocutaneous nerve and the brachial artery when MIPO is applied using ALPS, 45°- and 90°-helical implants.

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.

Modified use of the proximal humeral internal locking system (PHILOS) plate for distal femoral nonunions

PURPOSE

Nonunion is a common complication after a distal femoral fracture (DFF). Standard treatment consists of revision plating and/or bone grafting. Single lateral plating for a distal femoral nonunion can be insufficient in case of a persistent medial gap and compromised bone stock. Alternatively, dual plating can be used to treat a distal femoral nonunion, but to date there is no Gold standard. The aim of our study was to report our results after use of a minimally invasively placed proximal humeral internal locking system (Philos) plate as a medial buttress in the treatment of a distal femoral nonunion.

METHODS

Fifteen adult patients with a distal femoral nonunion were prospectively entered in a trauma database and retrospectively assessed. All patients underwent a similar operation, which included removal of failed hardware, nonunion debridement, fixation with a lateral plate, and a medial Philos plate combined with bone grafting. Data collected included union rate, time to union, complications and functional outcome.

RESULTS

In twelve out of fifteen patients (80%), the fracture united after our index operation. Median time to union was 4.8 months (range 1.6-15). Three patients (20%) needed additional bone grafting surgery. One patient underwent a Judet quadricepsplasty.

CONCLUSION

This study suggests that the Philos plate is a safe and effective adjunct as a medial buttress plate for distal femoral nonunions.

Vascular Safe Zone During Percutaneous Pinning of the Distal Femur

PURPOSE

During percutaneous pinning of the pediatric distal femur, iatrogenic vascular damage in the medial thigh is a frequent concern. The proximity of a proximal-medial pin to these vessels has never been studied in children. This study describes a radiologic vascular safe zone that is easily visualized during surgery (wherein the superficial femoral vessels are safely posterior).

METHODS

Patients ≤16 years old with magnetic resonance imaging of one or both femora between 2005 and 2020 were retrospectively reviewed. The "at-risk level" (ARL) was defined as the distal-most axial image with a femoral vessel anterior to the posterior condylar axis. A standardized retrograde lateral-to-medial pin was templated. A correlation matrix and least squares regression identified age and physeal width (PW) as ideal independent variables. A vascular safe zone above the medial femoral condyle (MFC) was modeled as a multiple of PW (i.e. x*PW) and needed to satisfy 3 age-dependent criteria: (1) at the ARL, the pin is medial to the vessels, (2) the pin exits the medial thigh before the ARL, and (3) the chosen "vascular safe zone" (x*PW) is always distal to the ARL.

RESULTS

Forty-three patients averaging 7.1±3.9 (0.3-16) years old were included. Intra-Class correlation coefficients were excellent (0.92-0.98). All measurements strongly correlated with age ( r =0.76-0.92, P <0.001) and PW ( r =0.82-0.93, P <0.001). All patients satisfied criteria 1. Criteria 2 was satisfied in all patients ≥6 years old, 86% of children 4-5, and only 18% of children ≤3. In children >3 years old, the largest safe zone that satisfied criteria 3 was 2×PW. On average, the ARL was 2.5×PW (99% CI 2.3-2.7) above the MFC. The average ARL in children ≥6 years old was significantly higher than 2×PW (162 mm vs. 120 mm, P <0.001).

CONCLUSION

During passage of a distal femur pin into the medial thigh, children ≥6 years old have a vascular safe zone that extends 2×PW proximal to the MFC. Surgeons should be cautious with medial pin placement in children 4-5 years old and, if possible, avoid this technique in children ≤3.

LEVEL OF EVIDENCE

IV.

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.

Biomechanical and anatomical considerations for dual plating of distal femur fractures: a systematic literature review

INTRODUCTION

Distal femur fractures are challenging injuries historically associated with high rates of nonunion and varus collapse with operative management. As a result, clinical and research interest in dual plating (DP) of distal femur fractures has seen a dramatic increase in recent years. The purpose of this study was to systematically review the literature regarding vascular anatomy and biomechanics of distal femur fractures treated with DP constructs.

MATERIALS AND METHODS

A systematic literature review of two medical databases (PubMed & Scopus) was performed to identify peer-reviewed studies on the anatomy and biomechanics regarding DP of distal femur fractures. A total of 1,001 papers were evaluated and 14 papers met inclusion criteria (6 anatomy and 8 biomechanics). Methodological quality scores were used to assess quality and potential bias in the included studies.

RESULTS

In the biomechanical studies, DP constructs demonstrated greater axial and rotational stiffness, as well as less displacement and fewer incidences of failure compared to all other constructs. Vascular studies showed that the femoral artery crosses the mid-shaft femur approximately 16.0-18.8 cm proximal to the adductor tubercle and it is located on average 16.6-31.1 mm from the femoral shaft at this location, suggesting that medial plate application can be achieved safely in the distal femur. The methodological quality of the included studies was good for biomechanical studies (Traa score 79.1; range 53-92.5) and excellent for anatomical studies (QUACs score 81.9; range 69.0-88.5).

CONCLUSIONS

Existing biomechanics literature suggests that DP constructs are mechanically stronger than other constructs commonly used in the treatment of distal femur fractures. Furthermore, medial distal femoral anatomy allows for safe application of DP constructs, even in a minimally invasive fashion. Dual plating should be considered for patients with distal femur fractures that have risk factors for instability, varus collapse, or nonunion.

Safe and dangerous zones for the superficial femoral artery in femoral surgery

The proximity of the superficial femoral artery (SFA) to the femur exposes the SFA to risks that have serious complications. Although surgeons have used the lateral or medial approach to lessen these risks, they have not been eliminated. Therefore, this study aimed to identify dangerous and safe zones in terms of the SFA that can be used during femoral surgical procedures, using anatomical reference points. Computed tomography angiography (CTA) of 50 patients aged between 16 and 60 years obtained from the local institution's database was examined. Radiological and clinical measurements were performed to determine the position of the SFA relative to the femur. The mean age of the patients included in this study was 38.08 ± 9.44 (16-60) years. The average ratio of the distance between the proximal and distal borders of the dangerous zone and the lateral joint spaces (LJS) to the distance between the greater trochanter (GT) and LJS was 0.5722 ± 0.053, respectively. The average ratio of the distance between the end of the dangerous zone and LJS to the distance between the GT and LJS was 0.4108 ± 0.05026. This study found that 40% and 60% of the clinically measured distance between the GT and LJS can be used to determine safe and dangerous zones during femoral surgery. Additionally, the half distance between the anterior superior iliac spine (ASIS) and medial joint space (MJS) and one-fourth of the distance between the ASIS and LJS can be used to determine safe and dangerous zones in patients whose GT are not easily palpated.

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.

Anatomical implications of the subvastus approach on major vascular injury during a distal femoral osteotomy: a computed tomographic venography study

PURPOSE

This study evaluated major vascular injury risk in distal femoral osteotomy (DFO) via the subvastus approach and examined the relationship between the posterior border of the vastus medialis (VM) and the superficial femoral artery (SFA) and vein (SFV).

METHODS

Eighty limbs from 80 patients were evaluated using lower extremity computed tomographic venography. The positional relationship between the VM, SFA, and SFV was evaluated by measuring the angle between each structure and the horizontal reference point (VMA: VM angle, FAA (femoral arterial angle), FVA (femoral venous angle) and the distance between VM and the SFA and SFV (VMAD: VM-arterial distance, VMVD: VM-venous distance) in each axial slice (0/10/20/30/40 mm) proximal to the level of the superior patellar margin. The proximity of the posterior border of the VM and the SFA/SFV as a vertical distance, measured between the slice of the superior border of the patella and the slice where the posterior border of the VM contacted the SFA was evaluated. Single and multiple regression analyses were performed using the vertical distance as the objective variable.

RESULTS

As the slice shifted proximally, the VMA significantly increased (24.9 ± 8.5, 36.3 ± 8.8, 47.4 ± 11.8, 59.9 ± 14, 70.3 ± 13.7 degrees, respectively, p < 0.001 between all slices) and moved posteromedially from a medial direction. FAA (94.2 ± 7, 86.9 ± 9.2, 78.4 ± 9.7, 71.4 ± 9.8, 66.6 ± 10.5 degree, respectively, p < 0.001 between all slices) and FVA (100.6 ± 4.9, 98.3 ± 5.9, 93.7 ± 7.5, 88 ± 9.2, 81.1 ± 10.5 degrees, respectively, p < 0.001 between all slices) decreased and moved from a posterolateral to a posteromedial direction, while VMAD (35.4 ± 7.8, 24.1 ± 7.3, 14.3 ± 6, 8.4 ± 7, 6.2 ± 6.3 mm, respectively, p < 0.001 between all slices) and VMVD significantly decreased (42.7 ± 7.3, 32 ± 7.4, 22.4 ± 6.8, 14.5 ± 10.6, 8.7 ± 7.1 mm, respectively, p < 0.001 between all slices). The average vertical distance was 36 ± 9.3 mm (range 18.6-61.5 mm). The body height and the patellar length significantly affected the vertical distance.

CONCLUSION

The posterior border of the VM shifted posteromedially from distal to proximal and contacted the SFA at an average of 36 mm from the suprapatellar border. Surgeons should be aware of the risk of major vascular injury during exposure and osteotomy.

LEVEL OF EVIDENCE

Case series, Level IV.

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.

The missing piece of the trauma armoury-medial femoral condyle plate

Fixation of distal femoral fractures is often challenging due to the fracture configuration and associated poor bone quality. Dual plating (lateral and medial) has become an acceptable option to provide improved stability versus a single plate fixation. Though there are several commercially available anatomically designed plates for the lateral femoral condyle, there is no anatomic plate available in UK specifically for medial fixation of distal femur fractures. Our aim is to determine the best suited pre-contoured plate for stabilising the medial femoral condyle (MFC). Right sided femur sawbones were used to determine how well 18 different pre-contoured anatomical plates (Depuy Synthes, Leeds, UK) fit the medial femoral condyle. Some of these had variable angle (VA) option. Lift off, fit and notch penetration were assessed and recorded independently by 4 orthopaedic trauma surgeons. The number and distribution of screws in the MFC that each plate allowed was also determined. To do this the MFC was divided into quadrants: Proximal anterior (PA), distal anterior (DA), proximal posterior (PP) and distal posterior (DP). The ipsilateral anterolateral proximal tibial (VA and 4.5 mm non-VA), PHILOS, posteromedial proximal tibial and ipsilateral lateral extra-articular distal humeral plate offered good sagittal fit, less than 2 mm lift off at the condyles and no diaphyseal lift off. Plate positioning in the PA quadrant offered the best fit. The ipsilateral anterolateral proximal tibial plates (VA) and PHILOS allowed at least 4 screws to be placed in the PA and 2 in the PP quadrant with no notch penetration. The Tomofix provided good fit, but all 4 screws were in PA quadrant, with distal screws causing notch penetration. The non-VA and PHILOS plates did not offer the VA advantage. The ipsilateral anterolateral proximal tibial VA plates provided the best anatomical fit for the MFC with the greatest number of screws in the condylar quadrants with the option of variable angle screw placement.

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.

Impact on periosteal vasculature after dual plating of the distal femur: a cadaveric study

Although dual plating of distal femur fractures has been described for injuries at risk of varus displacement, the vascular insult to the medial distal femur utilizing this technique is unknown. The aim of this study was to evaluate the perfusion of the medial distal femoral periosteal arteries after supplemental medial plating of the distal femur.

Methods

Fifteen human fresh-frozen cadaveric femora were thawed and randomized to lateral locked plating alone or with supplemental medial plate fixation. Conventional submuscular medial plating was performed using a 12-hole small fragment plate and multiple cortical screws. The superficial femoral artery was injected with latex dye. Specimens were dissected. The patency of the medial distal femoral periosteal vessels was evaluated.

Results

Four vessels were consistently observed traversing the distal medial femur: the transverse and descending (d-MMPA) branches of the medial metaphyseal periosteal artery, and the transverse and longitudinal branches of the descending geniculate artery. The anterior longitudinal arch (ALA) was present in 13 of 15 specimens and was fed by the d-MMPA. The median number of periosteal arteries occluded by the medial plate was 2 (6 out of 8 specimens). The d-MMPA was occluded in 6 of 8 medially plated femurs, resulting in a complete lack of perfusion of the ALA.

Conclusions

Submuscular medial plating of the distal femur compressed the d-MMPA in the majority of specimens. This vessel gives rise to the ALA, which lacked perfusion in these specimens. This vascular insult could affect the healing of metaphyseal distal femur fractures treated with dual plating.

Medial minimally invasive helical plate osteosynthesis of the distal femur - a new technique

INTRODUCTION

The goal of this study was to evaluate distal femoral minimally invasive plate osteosynthesis (MIPO) from a distal medial approach by use of a pre-bent helical implant.

MATERIAL & METHODS

A total of 18 lower extremities was evaluated. A 29.6 cm steel plate was constructed and pre-bent on bone specimens with a torsion of 55.7° A 5 cm incision was performed from the tip of the medial epicondyle alongside its centre in a proximal direction. The medial border of the vastus medialis was retracted anteriorly. The level of the proximal skin incision was determined using the length of the pre-bent plates. The proximal incision was performed at a length of 4 cm at the described height at a line between the lateral epicondyle and the tip of the greater trochanter. A raspatory was advanced beneath the vastus medialis in a proximal direction to create an extraperiosteal tunnel for plate insertion. The plate was fixed to the bone at its proximal and distal portion via screws. Following dissection, the distance between the nearest perforator to the proximal plate end was evaluated. The vertical distances between the medial border of the plate and the femoral artery and femoral nerve were measured at the level of the proximal plate end and at the level of the proximal margin of the vastoadductor membrane.

RESULTS

The most proximal perforating artery was located at a mean distance of 20.15 mm starting from the proximal plate margin. The mean interval between the medial border of the plate at the level of its proximal tip and the femoral artery was 51.9 mm. The average distance between the femoral nerve and the medial border of the proximal part of the plate was 42.3 mm. Regarding the interval between the medial border of the plate and the femoral artery, this was at a mean of 40.5 mm at the level of the proximal margin of the vastoadductor membrane. During dissection, none of the specimens showed any lesions of the adjacent anatomical characteristics.

CONCLUSION

Our results indicate MIPO of the distal femur from a medial approach as a safe technique.

Medial Submuscular Plating of the Distal Femur

Distal femur fractures are often treated with laterally based plate constructs. The use of medial plates is less common because of the concern for the proximity to vascular structures. With a solid understanding of the anatomy, the technique can be used more frequently to optimize fixation in medial distal femur fractures and osteoporotic, comminuted, bone loss, and periprosthetic fractures. This video demonstrates a safe technique for the medial submuscular plating of a distal femur fracture. The video covers indications for surgery and provides detailed anatomy of the structures at risk, especially the superficial femoral artery system.

Minimally invasive plate osteosynthesis with dual plating for periprosthetic distal femoral fractures following total knee arthroplasty

Introduction

Adequate treatment for periprosthetic distal femur fractures is challenging because of various reasons, including severe osteoporosis and distal fragments that are too small or too distal. We have introduced a new surgical technique for dual plating of periprosthetic distal femur fractures following total knee arthroplasty (TKA) and determined the clinical and radiological outcomes of minimally invasive plate osteosynthesis (MIPO) with a dual locking compression plate (LCP).

Materials and methods

Between January 2010 and July 2019, 18 patients [mean age, 74.8 (68–89) years; average follow-up period, 14.8 (12–43) months] underwent MIPO with distal femoral LCP laterally and proximal humeral internal locking system (PHILOS) medially for periprosthetic distal femoral fractures following TKA. The minimum follow-up was 1 year. The clinical and radiological outcomes were assessed using the modified WOMAC scores, knee range of motion, time to callus formation, time to union, and complications of malunion, nonunion, and shortening.

Results

The average time to union was 18.4 weeks (range, 10–51 weeks) and to callus formation was 7.8 weeks (range, 2–14 weeks). At the 1-year follow-up, the average JLETS was 37.6 (range, 24–53), average knee ROM was 110.3° (range, 80–135°), and average varus-valgus angles of the distal femur were 3.2° (range, −2.9–10.5°). No nonunion, broken plates, or implant failure occurred. Malunion occurred in three patients.

Conclusion

MIPO with dual LCP is a reliable method for stabilizing periprosthetic distal femoral fractures following TKA, with satisfactory bone union rates and low complication rates.

Anthropometric Factors on Safe Distances between Popliteal Vessels to the Femur for Cerclage Wiring of the Distal Femoral Fracture: A Magnetic Resonance Imaging Study

Background and Objectives: The proximity of the popliteal vessels in the distal femur may increase the risk of iatrogenic vascular injury during cerclage wiring. In this study, the closest location and distance of the popliteal vessels to the femur was examined using magnetic resonance imaging (MRI). The associations between anthropometric factors and the distance that would guide the placement of wires safely during surgery were also identified. Materials and Methods: We reviewed adult knee magnetic resonance images and recorded: (1) the relation and the shortest horizontal distance (d-H) from the femoral cortex to the popliteal vessels in axial images and (2) the vertical distance (d-V) from the adductor tubercle to the axial level of the d-H values in coronal images. The effects of anthropometric factors (sex, age, body height, body weight, body mass index, thigh circumference, femoral length and femoral width) on these distances were analysed. Results: Analysis of 206 knee magnetic resonance images revealed that the closet locations of popliteal vessels were at the posteromedial aspect of the femur. The d-H and d-V were 7.38 ± 3.22 mm and 57.01 ± 11.14 mm, respectively, and were both shorter in women than in men (p < 0.001). Multivariate analysis identified thigh circumference and femoral length as the most influential factors for the d-H and d-V, respectively (p < 0.001). Linear regression demonstrated a strong positive linear correlation between the thigh circumference and the d-H and between the femoral length and the d-V (Pearson’s r = 0.891 and 0.806, respectively (p < 0.001)). Conclusions: The closet location and distance of the popliteal vessels to the femur provide useful information for wire placement during distal femoral fracture surgery while minimising the risk of vascular injury. Given that patients with a smaller thigh circumference and a shorter femoral length are more likely to have a smaller d-H and a shorter d-V, respectively, cautious measures should be taken in such cases.

The effects of dual plating on the vascularity of the distal femur

AIMS

Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity.

METHODS

A total of eight cadaveric lower limb pairs were arbitrarily assigned to either 1) isolated lateral plating, or 2) lateral and medial plating of the distal femur, with four specimens per group. Contralateral limbs served as matched controls. Pre- and post-contrast MRI was performed to quantify signal intensity enhancement in the distal femur. Further evaluation of intraosseous vascularity was done with barium sulphate infusion with CT scan imaging. Specimens were then injected with latex medium and dissection was completed to assess extraosseous vasculature.

RESULTS

Quantitative MRI revealed a mean reduction of 21.2% (SD 1.3%) of arterial contribution in the lateral plating group and 25.4% (SD 3.2%) in the dual plating group (p = 0.051); representing a mean decrease in arterial contribution of 4.2%. The only significant difference found between both experimental groups was regionally, at the lateral aspect of the distal femur with a mean drop in arterial contribution in the lateral plating group of 18.9% (SD 2.6%) versus 24.0% (SD 3.2%) in the dual plating group (p = 0.048), representing a mean decrease in arterial contribution of 5.1%. Gross dissection revealed complete destruction of periosteal vessels underneath either medial or lateral plates in both groups. The network of genicular branches contributing to the posterior and distal femoral condyles was preserved in all specimens. A medial vascular pedicle was found dividing from the superficial femoral artery at a mean 12.7 cm (SD 1.7) proximal to the medial epicondyle and was undisrupted in the dual plating group.

CONCLUSION

Lateral locking-plate application resulted in mean 21.2% reduction in distal femur vascularity. Addition of medial plates did not further markedly decrease vascularity. As such, the majority of the vascular insult occurred with lateral plating alone. Supplemental medially based fixation did not lead to marked devascularization of the distal femur, and should therefore be considered in the setting of comminution and poor bone stock in distal femoral fractures. Further clinical research is required to confirm the results of this study. Cite this article: Bone Joint J 2020;102-B(4):530-538.

Intramedullary Nailing and Minimally Invasive Percutaneous Plate Osteosynthesis in Treatment of Displaced Clavicular Mid-shaft Fractures: A Prospective Study

OBJECTIVE

To compare the difference between MIPO and IMN methods in the treatment of displaced clavicular mid-shaft fractures.

METHODS

A total 163 patients were consecutively enrolled and randomly divided into the MIPO group or the IMN group. Clinical characteristics and outcomes including age, gender, causes of fractures, and AO/OTA type as well as hospitalization time, healing time, and postoperative complications were analyzed. Constant-Murley scores and DASH scores were used for assessment of shoulder joint and upper extremity function, respectively.

RESULTS

In this study, 82 cases received MIPO and 81 cases received IMN. The mean operation time, mean bleeding volume, mean hospitalization time, and mean healing time showed no significant difference between the MIPO and IMN groups. At 3 months after surgery, Constant-Murley scores were significantly higher and DASH scores were significantly lower in the MIPO group than the IMN group. No significant difference was observed for both indexes at 6 months. The fracture nonunion rate was significantly lower in the MIPO group. No significant difference was found in other complications.

CONCLUSION

Both methods were effective for the treatment of displaced clavicular mid-shaft fractures. However, the MIPO method might be better for recovery of shoulder and upper extremity function in the short term and might have a lower nonunion rate.

Course of the Femoral Artery in the Mid- and Distal Thigh and Implications for Medial Approaches to the Distal Femur: A CT Angiography Study

INTRODUCTION

Unfamiliarity with the location of the femoral artery in the medial thigh has tempered surgeons' enthusiasm for medial approaches to the distal femur. The purpose of this study was to define the relationship of the femoral artery to the mid- and distal femur to assist in safely approaching the femur for fracture care.

METHODS

Fifteen patients undergoing CT with angiography (CTA) of the lower extremity (CTA) were evaluated. From three-dimensional CTA images, the distance of the artery at the anterior border, midsagittal line, and posterior border of the femur from the distal femur at both the adductor tubercle and medial femoral condyle was measured.

RESULTS

The average distances of the adductor tubercle to the femoral artery were 23.2 cm (±3.3), 18.8 cm (±3.4), and 14.3 cm (±4.1) at the level of the anterior border, midsagittal line, and posterior border of the femur, respectively. The descending genicular artery (DGA) originated 10.8 cm (±1.3) proximal to the adductor tubercle.

DISCUSSION

A wide safe zone exists in the medial distal femur. The artery crosses the midsagittal axis of the medial femur an average of 18.8 cm proximal to the adductor tubercle.

Biomechanical assessment of single LISS versus double-plate osteosynthesis in the AO type 33-C2 fractures: A finite element analysis

OBJECTIVES

In the present study, we assessed the biomechanical advantage between the single LISS and double-plate used in AO type 33-C2 fractures with the method of finite element analysis, which will help surgeons choose the optimal therapy to the unstable distal femoral fracture.

METHODS

The AO type 33-C2 fractures and the models of LISS plate and medial plate was constructed in 3-matic software and UG-NX software respectively. We then assembled the single plate and the double-plate to the fracture model separately to form the fixation models. After meshing the models' elements, we used the Abaqus software to perform the finite element analysis. Values of peak Von Mises Stress (VMS) on the plate, maximum deformation of the models and the distance changes of the fracture gap were used to capture the mechanical factors in this study.

RESULTS

Our results indicated that the single LISS underwent 1.2 times higher amount of stress than the double-plate (316.0 MPa VS 281.6 MPa). And the medial plate dispersed some stresses (the maximum stress is 47.4 MPa). Single-plate generated 3 times greater bending angle than double-plate (0.6° VS 0.2°). The bending angles of the single and double-fixation-fracture models are 0.9° and 0.3° respectively. The maximum distance changes of the fracture gap in the single-plate model was 2 times higher than that of double-plate model (2.6 mm VS 1.3 mm). In the torsional load analysis, peak VMS of the single and double model was 1.0 MPa and 0.8 MPa respectively. And the bending angle was 0.8° in the single model and 0.4° in the double model.

CONCLUSIONS

The double-plate is more effective scenario using in the distal femoral fractures, particular in unstable fractures with joint involvement.

Is augmented LISS plating biomechanically advantageous over conventional LISS plating in unstable osteoporotic distal femoral fractures?

Treatment of complex osteoporotic distal femur fractures with the Less Invasive Stabilization System (LISS) has been associated with high complication rates. The aim of this study was to investigate the biomechanical competence of two different techniques of augmented versus conventional LISS plating. Unstable distal femoral fracture AO/OTA 33-A3 was created via osteotomies in artificial femora simulating osteoporotic bone. Three study groups, consisting of 10 specimens each, were created for fixation with either LISS plate, LISS plate with additional polylactide intramedullary graft, or LISS plate plus medial locking plate (double plating). All specimens were non-destructively tested under axial (20-150 N) and torsional (0-4 Nm) quasi-static loading. Each bone-implant construct was tested with two different working length (WL) configurations (long and short) of the LISS plate. Relative movements between the most medial superior and inferior osteotomy aspects were investigated via three-dimensional motion tracking analysis. Double plating revealed significantly smaller longitudinal and shear displacement than the other two techniques (p ≤ 0.001). In addition, LISS plus graft fixation was with significantly less longitudinal displacement in comparison to conventional LISS plating (p < 0.001). Long WL resulted in significantly higher longitudinal and shear displacement compared to short WL for LISS and LISS plus graft (p ≤ 0.032), but not for double plating (p > 0.999). In conclusion, intramedullary grafting resulted in significantly increased fracture stability under axial loading in comparison to conventional LISS plating. Although it was not efficient enough to provide comparable stability to double plating, intramedullary grafting may be considered as a useful biological alternative to the latter in a surgeon's armamentarium. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2604-2611, 2018.

Expert Tibial Nails for Treating Distal Tibial Fractures With Soft Tissue Damage: A Patient Series

Distal tibial fractures with soft tissue damage are relatively difficult to treat. We assessed the outcomes of patients with these fractures treated with the Expert Tibial Nail^® (DePuy Synthes, Raynham, MA) from March 2012 to December 2014. At 6 months postoperatively, the general health quality of patients was assessed using operative time, interval to return to work, American Orthopaedic Foot and Ankle Society ankle scale score, pain measured using a visual analog scale, and short-form health outcomes 36-item survey physical functioning and mental health dimension scores. Of 11 cases, 7 (63.6%) were open fractures (3 [27.3%] Gustilo-Anderson type II, 3 [27.3%] type IIIA, and 1 [9.1%] type IIIB) and 4 (36.4%) were closed fractures with Tscherne-Oestern type II tissue damage. Their mean age was 52.2 (range 28 to 66) years. The mean operative time was 83 (range 65 to 105) minutes. The mean follow-up period was 16.3 (range 14 to 18) months. The median short-form 36-item survey scores were 79.1 (range 68.9 to 89.0) for the physical function dimension and 77.0 (range 64.3 to 90.0) for the mental health dimension. The mean postoperative ankle score was 88.6 (range 84 to 94). The mean pain score was 1.6 (range 0 to 4) mm. The mean interval to return to work was 14 (range 11 to 17) months. No patient showed evidence of neurovascular damage, malunion, nonunion, or shortening of the tibia. Taken together, we have confirmed that Expert Tibial Nails can effectively treat distal tibial fractures with soft tissue damage.

Intraosseous Plating for the Management of Cortical Defects

The management of fractures with segmental bone loss or abundant comminution on the far cortex is often complicated by deformity or frank hardware failure. Using plate constructs that rely on off-axis loading may not be sufficient to support the limb until healing occurs. There are a number of techniques to mitigate this problem, notably the use of intramedullary nails and bicolumnar plating of the fracture. These techniques are not always possible and do come with the biologic cost of additional surgery. In this article, the authors present a technique along with 2 case examples of using plates in an intraosseous location that was described by Dr Mast in his classic orthopaedic text. By placing these plates in the intramedullary space and then interdigitating fixation from the standard cortical plate, a rigid "I-beam" of fixation can be created to mitigate the eccentric loading placed on extraosseous plates. This technique is especially useful in situations in which intramedullary nails are precluded (comminuted intraarticular and some periprosthetic fractures).

Percutaneous Application of a Medial Plate for Dual Plate Stabilization of Supracondylar Femur Fractures

Supracondylar femur fractures with segmental defects can be difficult fractures to treat. When associated with open wounds, these injuries can be associated with numerous complications including nonunion, malunion, infection, and arthrofibrosis. In this article, we review our algorithm for treating these fractures and highlight critical aspects of the process which differs from previous techniques described. We feel that this technique has specific benefits that mitigate infection risk and minimize additional soft-tissue insult without compromising stability. Our results demonstrate good postoperative knee range of motion, a high union rate, with low complication rates.

Safe zones and a technical guide for cerclage wiring of the femur: a computed topographic angiogram (CTA) study

INTRODUCTION

Cerclage wiring for reduction of complex femoral shaft fractures can create iatrogenic vascular injury.

OBJECTIVE

To describe the anatomical relation of blood vessels to the femur and develop a technical guide for safe passage of cerclage wire.

MATERIALS AND METHODS

CT lower-limb angiographs (CTA) of 80 patients were reviewed and analysed to identify the superficial femoral artery (SFA) and the deep femoral artery (DFA) as well as the relation of those arteries to the femoral cortex. The total length of the femur was measured and divided into eight equal segments (seven levels). At each level, the medial half of the femur was divided into eight sectors labelled A through H and the position of the SFA and DFA was recorded. The shortest distance between the femoral cortex and the SFA and DFA at each level was measured. The data was analysed using STATA version 10.0.

RESULTS

The average total femoral length from the tip of greater trochanter to lateral joint line was 402.98 ± 26.16 cm. The average distances from the SFA to the femur (d1) for levels 1 through 7 were 37.20 ± 5.0, 32.09 ± 4.74, 27.13 ± 4.19, 27.71 ± 5.46, 23.71 ± 4.40, 13.63 ± 3.59 and 10.08 ± 3.09 mm, respectively. The average distances between the DFA and the femur (d2) for levels 1 through 3 were 26.70 ± 4.13, 14.76 ± 3.27 and 9.58 ± 3.79 mm, respectively. The position of the SFA is located in sectors B through E at levels 1-3 and in sectors E through H at levels 4-7 and the position of the DFA located in sectors B through F at levels 1-3.

CONCLUSION

Cerclage wiring should be started from the posterior intermuscular septum at the linea aspera. The safe area is the proximal half (midshaft) of the femur where the SFA and DFA lie at a safe distance from the femur. Between the midshaft and the distal 1/4, insertion of the passer must be done meticulously with the tip kept close to posteromedial cortex. Below the distal 1/4, the tip of the passer should be kept close to the posterior cortex to avoid injury to the SFA and the sciatic nerve.

Medial Knee Approach: An Anatomical Study of Minimally Invasive Plate Osteosynthesis in Medial Femoral Condylar Fracture

OBJECTIVES

To determine the location of distal medial neurovascular structures, identifying a medial "safe zone" for minimally invasive plate osteosynthesis to treat displaced femoral condylar fractures.

METHODS

Eleven uninjured lower-half torsos were dissected on the bilateral medial lower thigh. A longitudinal incision was made at the midsagittal plane of the medial thigh starting 1 cm proximal to the knee joint and extending to the proximal one-third of the femur. Superficial and deep neurovascular structures were dissected. Distances to the medial vastus and adductor compartment were measured.

RESULTS

Mean distances were 160 ± 31.4 mm from the adductor tubercle to Hunter canal; 94 ± 18.3 mm from adductor tubercle to adductor hiatus; 31.8 ± 9.21 mm from Hunter canal to the femoral shaft; and 31.7 ± 7.78 mm from adductor hiatus to femoral shaft. All specimens had a descending genicular artery (DGA) with a mean distance to the adductor tubercle of 98.4 ± 16.0 mm. The muscular branch of the DGA crossed the femoral shaft at approximately 50 mm from the adductor tubercle; the osteoarticular branch ran along the adductor magnus tendon. The nerve to the vastus medialis was at the posterior border of the vastus medialis, entering at a mean 143 ± 63.0 mm from the adductor tubercle.

CONCLUSIONS

Minor neurovascular branches of the DGA may be vulnerable during medial femoral condyle plating. Careful blunt dissection, proper instrumentation, and plate length within 160 mm allow distal medial femur fixation without additional proximal dissection.

The floating knee: a review on ipsilateral femoral and tibial fractures

In 1975, Blake and McBryde established the concept of 'floating knee' to describe ipsilateral fractures of the femur and tibia.1 This combination is much more than a bone lesion; the mechanism is usually a high-energy trauma in a patient with multiple injuries and a myriad of other lesions.After initial evaluation patients should be categorised, and only stable patients should undergo immediate reduction and internal fixation with the rest receiving external fixation.Definitive internal fixation of both bones yields the best results in almost all series.Nailing of both bones is the optimal fixation when both fractures (femoral and tibial) are extra-articular.Plates are the 'standard of care' in cases with articular fractures.A combination of implants are required by 40% of floating knees.Associated ligamentous and meniscal lesions are common, but may be irrelevant in the case of an intra-articular fracture which gives the worst prognosis for this type of lesion. Cite this article: Muñoz Vives K, Bel J-C, Capel Agundez A, Chana Rodríguez F, Palomo Traver J, Schultz-Larsen M, Tosounidis, T. The floating knee. EFORT Open Rev 2016;1:375-382. DOI: 10.1302/2058-5241.1.000042.

What is new in distal femur periprosthetic fracture fixation?

Distal femoral periprosthetic fractures are on the rise. Increased mortality of these injuries is also evident from recent data. Their incidence and risk factors have been extensively reported in the past but new data are being available that merit attention. The increased incidence and the even higher projected incidence should direct the focus of future strategies to the education of surgeons, relevant capacity of hospital and reconfiguration of health care resources. New and potentially modifiable risk factors should be taken into consideration to the informed consent process and new studies should be developed to clarify the causative relationship of the new risk factors such as the peptic ulcer disease and the COPD. The main internal fixation techniques remain the lateral locking plating and the retrograde intramedullary nailing. New techniques in plating are the supplementary medial plate in selected cases and the far cortical locking. Nailing is considered a valid option especially in fractures located well above the anterior flange of the femoral component of the arthroplasty. Results and outcomes from good quality studies are still sparse regarding the comparison between plating and nailing. Interprosthetic fractures constitute an entity that is lately gaining considerable attention. The best method of management of these injuries is still evolving with considerable amount of work being done in the clinical and biomechanical level.