Distal femoral fractures: current treatment, results and problems

Dual Plate Fixation of Periprosthetic Distal Femur Fractures

OBJECTIVES

Dual implants for distal femur periprosthetic fractures is a growing area of interest for these challenging fractures with dual plating (DP) emerging as a viable construct for these injuries. In the current study, an experience with DP constructs is described.

METHODS

DESIGN

Retrospective case series with comparison group.

SETTING

Level 1 academic trauma center.

PATIENT SELECTION CRITERIA

Adults >50 years old sustaining comminuted OTA/AO 33-A2 or 33-A3 DFPF treated with either DP or a single distal femur locking plating (DFLP). Patients with simple 33-A1 fractures were excluded. Prior to 2018, patients underwent DFLP after which the treatment of choice became DP.

OUTCOME MEASURES AND COMPARISONS

Reoperation rate, alignment, and complications.

RESULTS

34 patients treated with DFLP and 38 with DP met inclusion and follow up criteria. Average follow up was 18.2 ± 13.8 months in the DFLP group and 19.8 ± 16.1 months in the DP group ( P = 0.339). The average patient age in the DFLP group was 74.8 ± 7.3 years compared to 75.9 ± 11.3 years in the DP group. There were no statistical differences in demographics, fracture morphology, loss of reduction, or reoperation for any cause ( P >.05). DP patients were more likely to be weight bearing in the twelve-week postoperative period ( P <0.001) and return to their baseline ambulatory status ( P = 0.004) compared to DFLP patients.

CONCLUSIONS

Dual plating of distal femoral periprosthetic fractures maintained coronal alignment with a low reoperation rate even with immediate weight bearing and these patients regained baseline level of ambulation more reliably as compared to patients treated with a single distal femoral locking plate.

LEVEL OF EVIDENCE

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

[Distal femoral fractures]

CLINICAL ISSUE

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

STANDARD TREATMENT PROCEDURE

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

TREATMENT INNOVATIONS

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

DIAGNOSTIC WORK-UP

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

PERFORMANCE

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

ASSESSMENT

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

PRACTICAL RECOMMENDATIONS

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

Stable internal fixation with dual plate technique for osteoporotic distal femur fractures

Background

Material and methods

Results

Conclusion

•

Osteoporotic distal femur fractures are difficult in terms of fracture treatment and recovery.

•

The minimally invasive plate osteosynthesis (MIPO) with the dual plate technique can provide rigid fixation for osteoporotic distal femur fractures.

•

This stable and rigid fixation may allow early mobilization and return to pre-fracture activity in elderly patients.

•

The MIPO with the dual plate technique could be useful treatment option for osteoporotic distal femur fractures.

Nail diameter significantly impacts stability in combined plate-nail constructs used for fixation of supracondylar distal femur fractures

Objectives:

Plate-nail (PN) combinations have been described for fixation of supracondylar distal femur fractures. Small diameter retrograde intramedullary nails (rIMN) are commonly used. The purpose of this study was to investigate the effect of nail diameter on construct stability. We hypothesized that a larger diameter rIMN would not significantly change the stiffness of the PN construct when tested in torsional or axial loading.

Methods:

Twelve synthetic osteoporotic femurs were used to compare nail diameters in an extraarticular supracondylar distal femur fracture model (Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen type 33-A3). Constructs were fixed with a 12-hole 4.5 mm pre-contoured lateral distal femoral locking plate combined with either a 9 mm (n = 6) or an 11 mm (n = 6) retrograde intramedullary nail (rIMN). Specimens were cyclically loaded in torsion and axial compression. The primary outcome was construct stiffness, calculated using the average slope of the force-displacement curves.

Results:

The 11 mm PN construct was approximately 1.6 times stiffer than the 9 mm PN construct averaged across all torsional loads (2.39 +/− 0.41 Nm/deg vs 1.44 +/− 0.17 Nm/deg) and approximately 1.3 times stiffer than the 9 mm PN construct averaged across all axial loads (506.84 +/− 44.50 N/mm vs 376.77 +/− 37.65 N/mm). There were no construct failures.

Conclusions:

In this biomechanical model, nail diameter had a significant effect on both torsional and axial stiffness in PN constructs. While the use of smaller diameter rIMNs has been proposed to allow for easier placement of implants, the effect on overall construct stiffness should be considered in the context of the patient, their fracture and desired postoperative weight bearing recommendations.

Level of Evidence: N/A

The Olerud Extensile Anterior Approach for Complex Distal Femoral Fractures: A Systematic Review

The management of AO/OTA (AO Foundation/Orthopaedic Trauma Association) 33-C3 complex distal femoral fractures presents challenges for orthopaedic surgeons. The extensile anterior approach may be an appropriate alternative treatment technique. The purpose of this systematic review is to (1) evaluate the Olerud approach (extensile anterior approach) for the treatment of 33-C3 complex distal femoral fractures and (2) evaluate postoperative patient outcomes. A systematic literature search was performed to retrieve studies that evaluated the treatment of 33-C3 complex distal femoral fractures. The PubMed database query resulted in 429 studies. Two reviewers independently reviewed the studies, of which six were identified. Patient demographics, AO/OTA fracture, surgical intervention, follow-up duration, clinical outcomes, and postoperative complications were collected and analyzed. The systematic review included six studies reporting on 85 patients (43 males and 42 females); the mean patient age was 45 years (range: 16-101 years). The most common cause of injury was road/traffic accident (51 patients). The mean follow-up time was 26 months (range: 3-72 months). In five studies, the mean time for union was 5.8 months (range: 2-9 months). The three most commonly reported complications were infection (seven [8.2%] patients), failure/malunion (three [3.5%] patients), and delayed tibial tuberosity osteotomy healing (three [3.5%] patients). Seventy (82.4%) patients did not suffer any postoperative complications. Out of 72 patients, 7 (9.7%) had resultant varus/valgus deformity. Overall, 57.1% had excellent/good functional outcomes. Based on the systematic literature review, the extensile anterior approach may be a viable alternative surgical option for 33-C3 complex distal femoral fractures. Given the current literature, more comprehensive and extensive studies need to be performed to ensure the best possible outcome.

Outcomes of distal femoral fractures treated with dynamic condylar screw (DCS) plate system: a single centre experience spanning 15 years

Introduction

the dynamic condylar screw (DCS) plate is an angular stable fixation (95°) system for distal femur fractures that allows for the ability to apply compression across the femoral condyles. The aim of this study was to evaluate our experience treating distal femur fractures with this device and give the long-term outcome.

Methods

a retrospective study was undertaken in our institution during the period from January 2002 to December 2016. A total number of 240 patients with distal femur fractures were managed using DCS plate system and included in the study. The mean follow-up period was 33 months (26 - 62 months). Clinico-radiological progression of fracture union as well as the functional outcome was studied.

Results

most of the fractures were closed injuries in young male patients resulting from traffic accidents. The average time to union was 12.6 weeks (range 11 - 23). Eight patients (3.3%) suffered superficial infection. Five patients (2.1%) developed deep venous thrombosis. Delayed union was observed in nine cases (3.7%) and non union in six cases (2.5%). At final follow-up, the mean range of motion (ROM) of knee was 115.7° (100°-148°). The mean Knee Society Score (KSS) was 84.5 (59 - 94) and the mean Lysholm score was 88.6 (range, 61 - 96), translating to good clinical results.

Conclusion

our study conclusively establishes that excellent functional outcome can be achieved with DCS plate inserted with skilled surgical technique in distal femur fractures including the ones that are communited or occurring in osteoporotic bone with a negligible complication rates.

A Unique Mode of Failure in the Noncontact Bridging Periprosthetic Plating System

Although lateral locking plates are often a preferred and successful fixation construct for the treatment of periprosthetic proximal and distal femur fractures, specific complications and modes of failure have been associated and well-described with their use. We present two cases of implant failure in the Non-Contact Bridge Periprosthetic Plating System (Zimmer Biomet) in which a nonlocked screw fretted through the annular seating of the plate. One case demonstrates failure in the setting of a proximal femur periprosthetic fracture, whereas the other demonstrates failure in the setting of a distal femur periprosthetic fracture. This unique mode of failure has not previously been reported in the literature.

In Vitro Macrophage Immunomodulation by Poly(ε-caprolactone) Based-Coated AZ31 Mg Alloy

Due to its excellent bone-like mechanical properties and non-toxicity, magnesium (Mg) and its alloys have attracted great interest as biomaterials for orthopaedic applications. However, their fast degradation rate in physiological environments leads to an acute inflammatory response, restricting their use as biodegradable metallic implants. Endowing Mg-based biomaterials with immunomodulatory properties can help trigger a desired immune response capable of supporting a favorable healing process. In this study, electrospun poly(ε-caprolactone) (PCL) fibers loaded with coumarin (CM) and/or zinc oxide nanoparticles (ZnO) were used to coat the commercial AZ31 Mg alloy as single and combined formulas, and their effects on the macrophage inflammatory response and osteoclastogenic process were investigated by indirect contact studies. Likewise, the capacity of the analyzed samples to generate reactive oxygen species (ROS) has been investigated. The data obtained by attenuated total reflection Fourier-transform infrared (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS) analyses indicate that AZ31 alloy was perfectly coated with the PCL fibers loaded with CM and ZnO, which had an important influence on tuning the release of the active ingredient. Furthermore, in terms of degradation in phosphate-buffered saline (PBS) solution, the PCL-ZnO- and secondary PCL-CM-ZnO-coated samples exhibited the best corrosion behaviour. The in vitro results showed the PCL-CM-ZnO and, to a lower extent, PCL-ZnO coated sample exhibited the best behaviour in terms of inflammatory response and receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated differentiation of RAW 264.7 macrophages into osteoclasts. Altogether, the results obtained suggest that the coating of Mg alloys with fibrous PCL containing CM and/or ZnO can constitute a feasible strategy for biomedical applications.

Early versus delayed weight bearing after surgical fixation of distal femur fractures: a non-randomized comparative study

Distal femur fractures are rare injuries with a bimodal distribution (high-energy injury in young males and low-energy fragility fractures in old females). Their management can be challenging: open reduction and internal fixation (ORIF) with distal femur locking plates is a commonly performed procedure especially in comminuted fractures with articular involvement. Anxiety regarding the stability of the fixation, especially in osteoporotic bone, leads to post-operative restrictive instructions with limitations regarding the weight-bearing status. Early weight bearing (EWB), however, was shown to enhance bone healing and was not correlated with an increased risk of fracture displacement or implant failure in previous published studies, which reported the results of proximal femur, tibia and ankle fractures surgical treatment. The current study analysed the results of a series of distal femur fractures (51 patients, mean age 64.3 ± 20.7) all treated with ORIF in a level-I major trauma centre, but differently rehabilitated. Group A was, in fact, instructed not to weight bear or to touch weight bear, while group B started to weight bear soon after surgery without specific restrictions. The objective was to compare the outcome and the complication rate in the two groups at 6 and 12 weeks after surgery. The results showed no statistically significant differences in the two groups and no post-operative complications in the EWB group. Six complications were observed in the non-weight-bearing group (four fractures displacement and two implants failure at 12-week follow-up). Distal femur fractures treated with locking plates can be rehabilitated with EWB to allow early return to function. There is no evidence that EWB increases the risk of fracture displacement or implant failure in distal femur fractures treated with distal locking plates. Instead, it is possible that post-operative non-weight-bearing status delays the fracture-healing process increasing the risk of failure of the fixation.

Monofilament Cerclage Wiring Fixation with Locking Plates for Distal Femoral Fracture: Is it Appropriate?

PURPOSE

We aimed to determine the efficacy of cerclage wiring by comparing the clinical and radiological results between internal fixation with locking plates after distal femoral fracture reduction with or without cerclage wiring.

MATERIALS AND METHODS

One hundred and one patients who received open reduction internal fixation for distal femoral fractures of oblique, spiral, and spiral wedge type between 2007 and 2014 were reviewed retrospectively. Only locking plate fixation was performed in 46 patients, and locking plate fixation with additional cerclage wiring was performed in 55 patients (Group CW). Demographic, clinical, and radiologic factors were evaluated in both the groups. Age, gender, bone mineral density, bone graft, and the presence of concomitant fractures were measured as demographic factors. The range of motion of knee joint, Lysholm knee score, visual analog scale score, procedure time, and C-arm time were measured as clinical factors preoperatively and at the final followup. We also evaluated the duration of bone union and knee joint alignment radiologically.

RESULTS

There were no demographic differences between the two groups. Furthermore, there were no statistically significant differences between the two groups in terms of clinical and radiological parameters. However, the procedure time used was significantly longer in Group LP than in Group CW (108.4 vs. 95.2 min; P = 0.027). The C-arm time was longer in Group LP (2.8 vs. 1.2 s; P = 0.017).

CONCLUSIONS

Open reduction and locking plate fixation with additional cerclage wiring is a useful method for the reduction of complicated distal femoral fractures, without increased complications such as nonunion.

LEVEL OF EVIDENCE

Level III, retrospective cohort design, treatment study.

Hybrid fracture fixation systems developed for orthopaedic applications: A general review

Orthopaedic implants are applied daily in our orthopaedic clinics for treatment of musculoskeletal injuries, especially for bone fracture fixation. To realise the multiple functions of orthopaedic implants, hybrid system that contains several different materials or parts have also been designed for application, such as prosthesis for total hip arthroplasty. Fixation of osteoporotic fracture is challenging as the current metal implants made of stainless steel or titanium that are rather rigid and bioinert, which are not favourable for enhancing fracture healing and subsequent remodelling. Magnesium (Mg) and its alloys are reported to possess good biocompatibility, biodegradability and osteopromotive effects during its in vivo degradation and now tested as a new generation of degradable metallic biomaterials. Several recent clinical studies reported the Mg-based screws for bone fixation, although the history of testing Mg as fixation implant was documented more than 100 years ago. Truthfully, Mg has its limitations as fixation implant, especially when applied at load-bearing sites because of rather rapid degradation. Currently developed Mg-based implants have only been designed for application at less or non-loading-bearing skeletal site(s). Therefore, after years research and development, the authors propose an innovative hybrid fixation system with parts composed of Mg and titanium or stainless steel to maximise the biological benefits of Mg; titanium or stainless steel in this hybrid system can provide enough mechanical support for fractures at load-bearing site(s) while Mg promotes the fracture healing through novel mechanisms during its degradation, especially in patients with osteoporosis and other metabolic disorders that are unfavourable conditions for fracture healing. This hybrid fixation strategy is designed to effectively enhance the osteoporotic fracture healing and may potentially also reduce the refracture rate. The translational potential of this article: This article systemically reviewed the combination utility of different metallic implants in orthopaedic applications. It will do great contribution to the further development of internal orthopaedic implants for fracture fixation. Meanwhile, it also introduced a titanium-magnesium hybrid fixation system as an alternative fixation strategy, especially for osteoporotic patients.

Distal femur: dynamization of plating

With advances in osteosynthesis technology providing improved stability of fixation and better outcomes, surgical treatment has become the standard of care for distal femur fractures. Pre-contoured distal femoral locking plates are the most commonly used implants for fixation. However, healing problems such as delayed union, failure of fixation, and /or nonunion are not uncommon. The fixation construct being "too stiff" is a commonly quoted reason when nonunion/failure of fixation occurs on distal femur fractures fixed with a plate. A flexible fixation construct allowing controlled axial micromotion could help stimulate the bone healing. In order to achieve this goal, plating construct stiffness can be modified by several methods.

Modulation of Osteoclast Interactions with Orthopaedic Biomaterials

Biomaterial integration in bone depends on bone remodelling at the bone-implant interface. Optimal balance of bone resorption by osteoclasts and bone deposition by osteoblasts is crucial for successful implantation, especially in orthopaedic surgery. Most studies examined osteoblast differentiation on biomaterials, yet few research has been conducted to explore the effect of different orthopaedic implants on osteoclast development. This review covers, in detail, the biology of osteoclasts, in vitro models of osteoclasts, and modulation of osteoclast activity by different implant surfaces, bio-ceramics, and polymers. Studies show that surface topography influence osteoclastogenesis. For instance, metal implants with rough surfaces enhanced osteoclast activity, while smooth surfaces resulted in poor osteoclast differentiation. In addition, surface modification of implants with anti-osteoporotic drug further decreased osteoclast activity. In bioceramics, osteoclast development depended on different chemical compositions. Strontium-incorporated bioceramics decreased osteoclast development, whereas higher concentrations of silica enhanced osteoclast activity. Differences between natural and synthetic polymers also modulated osteoclastogenesis. Physiochemical properties of implants affect osteoclast activity. Hence, understanding osteoclast biology and its response to the natural microarchitecture of bone are indispensable to design suitable implant interfaces and scaffolds, which will stimulate osteoclasts in ways similar to that of native bone.

Open Supracondylar-Intercondylar Fractures of the Femur Treatment With Taylor Spatial Frame

OBJECTIVES

To evaluate the Taylor spatial frame (TSF) for primary and definitive fixation of open supracondylar-intracondylar femoral (SIF) fractures.

DESIGN

Retrospective.

SETTING

Level I trauma center.

PATIENTS

Subset of 20 SIF open fractures treated with TSF extracted from a consecutive series of 80 SIF fractures treated between 2007 and 2013.

INTERVENTION

Eighteen (90%) fractures underwent definitive fixation with the TSF; 2 were treated primarily within 24 hours of injury. Mean time interval between primary treatment and secondary TSF was 5 days.

MAIN OUTCOME MEASUREMENTS

Clinical and radiological.

RESULTS

Complete union was obtained in 17 (85%) fractures without additional surgery at an average of 33 weeks. Three nonunions and 1 malunion occurred. No deep infection occurred. Results based on Association for the Study and Application of the Method of Ilizarov criteria: 37% excellent, and 63% good for bone outcomes; 5% excellent, 58% good, and 37% fair for functional outcomes. Neer knee scores were 21% excellent, 68% good, and 11% fair. The mechanical lateral distal femoral angle and anatomic posterior distal femoral angle values were within normal range in 80% and 90% of patients, respectively. Abnormal mechanical axis deviation was observed in 4 (20%) cases (2 had associated tibia fractures).

CONCLUSIONS

Primary and definitive fixation with the TSF are effective. Advantages include continuity of device until union, reduced risk of infection, early mobilization, restoration of primary defect caused by bone loss, easy and accurate application, convertibility and versatility, and improved union rate and range of motion for SIF open fractures.

LEVEL OF EVIDENCE

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

Implant Material, Type of Fixation at the Shaft, and Position of Plate Modify Biomechanics of Distal Femur Plate Osteosynthesis

OBJECTIVES

To investigate whether (1) the type of fixation at the shaft (hybrid vs. locking), (2) the position of the plate (offset vs. contact) and (3) the implant material has a significant effect on (a) construct stiffness and (b) fatigue life in a distal femur extraarticular comminuted fracture model using the same design of distal femur periarticular locking plate.

METHODS

An extraarticular severely comminuted distal femoral fracture pattern (OTA/AO 33-A3) was simulated using artificial bone substitutes. Ten-hole distal lateral femur locking plates were used for fixation per the recommended surgical technique. At the distal metaphyseal fragment, all possible locking screws were placed. For the proximal diaphyseal fragment, different types of screws were used to create 4 different fixation constructs: (1) stainless steel hybrid (SSH), (2) stainless steel locked (SSL), (3) titanium locked (TiL), and (4) stainless steel locked with 5-mm offset at the diaphysis (SSLO). Six specimens of each construct configuration were tested. First, each specimen was nondestructively loaded axially to determine the stiffness. Then, each specimen was cyclically loaded with increasing load levels until failure.

RESULTS

Construct Stiffness: The fixation construct with a stainless steel plate and hybrid fixation (SSH) had the highest stiffness followed by the construct with a stainless steel plate and locking screws (SSL) and were not statistically different from each other. Offset placement (SSLO) and using a titanium implant (TiL) significantly reduced construct stiffness. Fatigue Failure: The stainless steel with hybrid fixation group (SSH) withstood the most number of cycles to failure and higher loads, followed by the stainless steel plate and locking screw group (SSL), stainless steel plate with locking screws and offset group (SSLO), and the titanium plate and locking screws group (TiL) consecutively. Offset placement (SSLO) as well as using a titanium implant (TiL) reduced cycles to failure.

CONCLUSIONS

Using the same plate design, the study showed that implant material, screw type, and position of the plate affect the construct stiffness and fatigue life of the fixation construct. With this knowledge, the surgeon can decide the optimal construct based on a given fracture pattern, bone strength, and reduction quality.

Isolated lower limb hypoplasia secondary to congenital varicella syndrome: a rare occurrence and management of its complications

Isolated lower limb hypoplasia is a rare consequence of maternal congenital varicella syndrome (CVS). The hypoplastic limb is susceptible to multiple injuries, including fractures, especially if there is associated muscle weakness and lack of sensation. We describe a unique index case of a woman aged 26 years with a background of CVS who presented with a distal femur fracture following a fall onto her insensate, hypoplastic right leg. This report highlights the complexities involved in the diagnosis and management of fractures in patients with an anaesthetic limb, and in particular describes limb amputation as a successful treatment modality for distal femur fractures.

Treatment Options for Distal Femur Fractures

Despite advances in implant design, the management of distal femur fractures remains challenging. Fracture comminution and intra-articular extension can make it difficult to obtain an adequate reduction while preserving the soft tissue attachments to bone fragments to allow for bone healing. Many implant manufacturers have developed optimal anatomically contoured, distal femoral locking plates with percutaneous guides. This environment allows for the application of lateral locked plates in a biologically friendly manner. Although initial reports had high success rates, more recently a high rate of nonunion has been found, particularly in elderly patients. Limited literature is available for the treatment of patients with osteoporotic bone and associated ipsilateral total knee replacement and hip replacement. We present a patient with a distal femur fracture with significant comminution in the setting of an ipsilateral total hip replacement.

Retrograde dynamic locked intramedullary nailing for aseptic supracondylar femoral nonunion after dynamic condylar screw treatment

OBJECTIVE

Supracondylar femoral nonunions after dynamic condylar screw (DCS) treatment are uncommon, and few studies have addressed an optimal treatment technique for this disorder. Re-insertion of a new plate may not be secure because of bony defects in the distal fragment, created by the lag screw of the DCS.

MATERIALS AND METHODS

Forty-two consecutive adult patients with 42 supracondylar femoral nonunions were treated with removal of the DCS, re-alignment of the knee axis, and insertion of a retrograde dynamic traditional femoral locked nail. When necessary, a humeral plate was augmented to reinforce rotational stability.

RESULTS

A final group of 36 patients with 36 nonunions were followed for an average of 2.8 years (range 1.1-6.2 years). All nonunions healed with a union rate of 100 %, and the average time to union was 4.2 months (range 2.5-5.5 months). Complications included two malunions. There were no instances of nonunion or deep infection. Satisfactory knee function among 36 patients improved from 8.2 % preoperatively to 86.1 % at the last follow-up (p < 0.001). All 36 patients could walk without aids.

CONCLUSION

The described technique may be an excellent alternative treatment for an aseptic supracondylar femoral nonunion after DCS treatment. The technique is not difficult, and the union rate and satisfactory rate are high.

Periarticular Fractures of the Knee in Polytrauma Patients

Periarticular fractures around the knee are a challenge for the orthopaedic surgeon. When these fractures are presented in the context of a multiple trauma patient, they are even more difficult to manage because the treatment approach depends not only on the fracture itself, but also on the patient's general condition. These fractures, caused by high-energy trauma, present complex fracture patterns with severe comminution and major loss of articular congruity, and are often associated with vascular and nerve complications, particularly in the proximal tibia, due to its anatomical features with poor myocutaneous coverage. They are almost always accompanied by soft tissue injury. The management of polytrauma patients requires a multidisciplinary team and accurate systemic stabilization of the patient before undertaking orthopaedic treatment. These fractures are usually addressed sequentially, either according to the general condition of the patient or to the local characteristics of the lesions. In recent decades, various fixation methods have been proposed, but there is still no consensus as to the ideal method for stabilizing these fractures. In this paper, we describe the general characteristics of these fractures, the stabilization methods traditionally used and those that have been developed in recent years, and discuss the treatment sequences proposed as most suitable for the management of these injuries.

Overlapping intramedullary nailing after failed minimally invasive locked plating for osteoporotic distal femur fractures--Report of 2 cases

Minimally invasive plate osteosynthesis (MIPO) using a locking plate has been widely used for distal femur fractures in the elderly with osteoporosis and yielded favourable results. However, implant failure and subsequent periplate fracture have still occurred owing to the controversy of concepts regarding locked plating. The treatment after failed MIPO in elderly patients is very challenging and has been not yet addressed definitely in the literature, although several options can be considered. We report the successful outcomes of two cases treated with overlapping intramedullary (IM) nailing for implant failure and periplate fracture after MIPO for osteoporotic distal femur fracture, along with simple tips of distal interlocking of IM nail.

Internal fixators: a safe option for managing distal femur fractures?

OBJECTIVE:

Evaluate safety and reliability of internal fixator for the treatment of intra-articular and periarticular distal femur fractures.

METHODS:

Retrospective data evaluation of 28 patients with 29 fractures fixed with internal fixator was performed. There was a predominance of male patients (53.5%), with 52% of open wound fractures, 76% of AO33C type fractures, and a mean follow up of 21.3 months. Time of fracture healing, mechanical axis deviation, rate of infection and postoperative complications were registered.

RESULTS:

Healing rate was 93% in this sample, with an average time of 5.5 months. Twenty-seven percent of patients ended up with mechanical axis deviation, mostly resulting from poor primary intra-operative reduction. There were two cases of implant loosening; two implant breakage, and three patients presented stiff knee. No case of infection was observed. Healing rate in this study was comparable with current literature; there was a high degree of angular deviation, especially in the coronal plane.

CONCLUSION:

Internal fixators are a breakthrough in the treatment of knee fractures, but its use does not preclude application of principles of anatomical articular reduction and mechanical axis restoration.

Level of Evidence II, Retrospective Study.

Mono- versus polyaxial locking plates in distal femur fractures - a biomechanical comparison of the Non-Contact-Bridging- (NCB) and the PERILOC-plate

Background

The aim of this cadaveric study was to compare a polyaxial (NCB®, Zimmer) to a fixed-angle monoaxial locking plate (PERILOC®, Smith & Nephew) in comminuted fractures of the distal femur regarding stability of the construct. Up to date there is no published biomechanical data concerning polyaxial plating in cadaveric distal femurs.

Methods

Fourteen formalin fixed femora were scanned by dual-energy x-ray absorptiometry. As fracture model an unstable supracondylar comminuted fracture was simulated. Fractures were pairwise randomly fixed either with a mono- (group A) or a polyaxial (group B) distal femur plate. The samples were tested in a servohydraulic mechanical testing system starting with an axial loading of 200 N following an increase of 200 N in every step with 500 cycles in every sequence up to a maximum of 2 000 N. The end points were implant failure or relevant loss of reduction. Data records included for each specimen time, number of cycles, axial load and axial displacement. Statistical analysis was performed using the exact Wilcoxon signed rank test.

Results

The mean donor age at the time of death was 75 years. The bone mass density (BMD) of the femurs in both groups was comparable and showed no statistically significant differences. Five bones failed before reaching the maximum applied force of 2000 N. Distribution curves of all samples in both groups, showing the plastic deformation in relation to the axial force, showed no statistically significant differences.

Conclusions

Operative stabilization of distal femur fractures can be successfully and equally well achieved using either a monoaxial or a polyaxial locking plate. Polyaxial screw fixation may have advantages if intramedullary implants are present.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-369) contains supplementary material, which is available to authorized users.

Treatment of distal femur fractures in a regional Australian hospital

AIM: To review our outcomes and compare the results of the Less Invasive Stabilization System (LISS) to other implants for distal femur fracture management at a regional Australian hospital.

METHODS: The LISS is a novel implant for the management of distal femur fractures. It is, however, technically demanding and treatment results have not yet been assessed outside tertiary centres. Twenty-seven patients with 28 distal femur fractures who had been managed surgically at the Mackay Base Hospital from January 2004 to December 2010 were retrospectively enrolled and assessed clinically and radiologically. Outcomes were union, pain, Lysholm score, knee range of motion, and complication rates.

RESULTS: Twenty fractures were managed with the LISS and eight fractures were managed with alternative implants. Analysis of the surgical techniques revealed that 11 fractures managed with the LISS were performed according to the recommended principles (LISS-R) and 9 were not (LISS-N). Union occurred in 67.9% of fractures overall: 9/11 (82%) in the LISS-R group vs 5/9 (56%) in the LISS-N group and 5/8 (62.5%) in the alternative implant group. There was no statistically significant difference between pain, Lysholm score, and complication rates between the groups. However, there was a trend towards the LISS-R group having superior outcomes which were clinically significant. There was a statistically significant greater range of median knee flexion in the LISS-R group with compared to the LISS-N group (P = 0.0143) and compared with the alternative implant group (P = 0.0454).

CONCLUSION: The trends towards the benefits of the LISS procedure when correctly applied would suggest that not only should the LISS procedure be performed for distal femur fractures, but the correct principle of insertion is important in improving the patient’s outcome.

Results in treatment of distal femur fractures using polyaxial locking plate

Indications and techniques of locked plate fixation for the treatment of challenging fractures continue to evolve. As design variant of classic locked plates, the polyaxial locked plate has the ability to alter the screw angle and thereby, enhance fracture fixation. The aim of this observational study was to evaluate clinical and radiographic results in 89 patients with 90 fractures of the distal femur treated, between June 2006 and November 2011, with such a polyaxial locked plating system (Polyax™ Locked Plating System, DePuy, Warsaw, IN, USA). Seventy-seven fractures formed the report of this study. These cases were followed up until complete fracture healing or for a mean time of 77 weeks. At the time of last follow-up, 58 of 77 fractures (75.3 %) progressed to union without complication and radiographic healing occurred at a mean time of 16.3 weeks. Complications occurred in ten fractures that did not affect the healing and in nine fractures that showed delayed or non-union. The mean American Knee Society Score at the time of final follow-up was 83 for the Knee Score and 71.1 for the Functional Score. In conclusion, there is a high union rate for complex distal femoral fractures associated with a good clinical outcome in this series.

Distal femoral replacement for selective periprosthetic fractures above a total knee arthroplasty

BACKGROUND AND AIM

The management of distal femur periprosthetic fractures in the elderly remains a challenge. The aim of this study was to evaluate the results of distal segmental femur replacement as an alternative to fixation in complex distal femoral periprosthetic fractures in elderly patients.

METHODS

Twelve patients were included in this prospective study, with a mean age of 78 years (range 68-90 years); incidentally, all were female. Fractures of the distal femur were classified as per Kim et al.'s classification (Clin Orthop Relat Res 446:167-175, 2006); our series included eight patients with type III and four patients with type II periprosthetic fractures. All 12 patients were treated with segmental distal femur replacement (Zimmer Inc., Warsaw, IN, USA). Nine patients required 90 cm and three patients required 130 cm of distal femur segment with a rotating hinge knee prosthesis.

RESULTS

The mean follow up period was 20 months (range 15-28 months), with no major surgical complications reported. The mean duration of hospital stay following surgery was 12 days (range 7-36 days). All patients were mobilising full weight-bearing by day 3. All patients returned to their prior living arrangements. Ten patients returned to their original domicile, with one patient being discharged to a care home requiring minimal ambulatory assistance. The remaining two patients returned to their care homes.

CONCLUSIONS

WOMAC scores improved from the pre-injury state with a mean of 49.62 to 72.54 post-surgery (p-value of 0.0001). The Knee Society scores, possible only following surgery, had a mean value of 72. The mean VAS pain score was 1.75 (0 = no pain to 10 = worst pain ever felt). The average range of knee flexion was from 4° to 89° (range -5° to 110°). The mean SF-36 physical functioning score was 45.64 [range 40.70-48.90; standard deviation (SD) -2.62] and the mean SF-36 mental functioning score was 52.94 (range 45.8-57.70; SD -3.38).

Femoral fracture reduction with a parallel manipulator robot on a traction table

BACKGROUND

A parallel manipulator robot (PMR) on a traction table was developed to achieve better alignment of a fractured femur and reduce radiation exposure to both patients and physicians.

METHODS

A PMR was built with a disk platform and a two-thirds circular ring. Fracture reductions were performed on eight artificially broken sawbone models and a cadaveric model. Fracture reduction was achieved using six degrees of freedom (6-DOF) movements of the two-thirds circular ring, while the PMR disk platform and the proximal femur remained stationary.

RESULTS

Axial discrepancy, lateral translation and angulation had mean errors of 1.31 ± 0.45, 2.43 ± 0.49 and 2.26 ± 0.23 mm, respectively, when coarse adjustment was used. For the fine adjustment step, the mean errors were 0.63 ± 0.19 mm for axial discrepancy and 0.75 ± 0.26 mm for lateral translation.

CONCLUSION

Femoral shaft fracture reduction with PMR on a traction table is a feasible and accurate approach to fracture reduction.

Biomechanical comparison of locked plating and spiral blade retrograde nailing of supracondylar femur fractures

OBJECTIVE

Biomechanical comparison between locked plating and retrograde nailing of supracondylar femur fractures with simulated postoperative weight-bearing.

METHODS

The Locking Condylar Plate (LCP) and Retrograde/Antegrade EX Femoral Nail (RAFN) were tested using 10 paired elderly cadaveric femurs, divided into Normal and Low Bone Mineral Density (BMD) groups, with a simulated AO/OTA type 33-A3 supracondylar femur fracture. Each specimen was subjected to 200,000 loading cycles in an attempt to simulate six weeks of postoperative recovery with full weight-bearing for an average individual. The construct's subsidence due to cyclic loading, and axial stiffness before and after the cyclic loading were measured and their correlation with BMD was studied. The two implants were compared in a paired study within each BMD group.

RESULTS

LCP constructs showed higher axial stiffness compared to RAFN for both Normal and Low BMD groups (80% and 57%, respectively). After cyclic loading, axial stiffness of both constructs decreased by 20% and RAFN constructs resulted in twice as much subsidence (1.9 ± 0.6mm). Two RAFN constructs with Low BMD failed after a few cycles whereas the matched pairs fixed with LCP failed after 70,000 cycles.

CONCLUSIONS

The RAFN constructs experienced greater subsidence and reduced axial stiffness compared to the LCP constructs. In Low BMD specimens, the RAFN constructs had a higher risk of failure.

Current options to surgical treatment in osteoporotic fractures

Treatment of osteoporotic fractures leads to significant challenges for the surgeon, including poor implant fixation related to low bone quality and compromised capacity of fracture healing. This article reviews the osteosynthesis and arthroplasty results in the surgical treatment of proximal femur, proximal humerus and wrist fractures to define the current options to decrease failure in fragility fracture management.

Currents of plate osteosynthesis in osteoporotic bone

Osteoporotic fractures are becoming more prevalent with ageing of populations worldwide. Inadequate fixation or prolonged immobilization after non-surgical care leads to serious life-threatening events, poor functional results and lifelong disability. Thus, a stable internal fixation and rapid initiation of rehabilitation are required for faster return of function. Conventional internal fixation attempts to achieve the exact anatomy, often with extended soft-tissue stripping and compression of the periosteum, causing disturbance of the metaphyseal and comminuted fracture's bone blood supply. This technique relies on frictional forces between bone and plate. Osteoporotic bone might not be able to generate enough torque with the screw to securely fix the plate to bone. Thus, this surgical management have resulted in increased incidence of poor results in elderly, osteoporotic patients. The newly developed locked internal fixators, locking compression plates and less invasive stabilization system, consist of plate and screw systems where the screws are locked in the plate, minimizing the compressive forces exerted between plate and bone. Thus, the plate does not need to compress the bone nor requires precise anatomical contouring of a plate disturbing the periosteal blood supply. These fixators allowed the development of the minimal invasive percutaneous osteosynthesis. Nowadays, locking plates are the fixation method of choice for osteoporotic, diaphyseal or metaphyseal, severely comminuted fractures.

Parallel manipulator robot assisted femoral fracture reduction on traction table

The principle of femoral shaft fracture reduction is to restore its pre-fractured limb length and mechanical axis. The current documented treatment method with traction table reduction does not conform to the quantitative alignment and reduction. There is also a great amount of X-Ray radiation exposure to both surgeon and patient during the procedure. For this reason, we introduced an innovated Parallel Manipulator Robot (PMR) application: A Femoral Shaft Fracture Reduction with Parallel Manipulator Robot on Traction Table. With this application, the quantitative control on fracture reduction and alignment can be achieved and the radiation exposure to both surgeons and patients can be greatly reduced.

Distal femoral fractures treated with condylar buttress plate in a West African hospital

OBJECTIVES

The aim of this retrospective study was to present our experience using condylar buttress plate in the treatment of distal femoral fractures.

PATIENTS AND METHODS

Thirty-two patients underwent open reduction and internal fixation with condylar buttress plates for distal femoral fractures from October 2000 through May 2010. Patient demographics, type of fracture, treatment, complications, results achieved, and follow-up assessment were reviewed. The fractures were classified with the AO system. The functional outcome was rated according to Schatzker and Lambert criteria.

RESULTS

There were 22 men and 10 women with an average age was 44 (range 19-87) years. The fractures were classified as A1 (n = 7; 21.8%), A2 (n = 4; 12%), A3 (n = 5; 15.6%); C1 (n = 4; 12.5%), C2 (n = 6; 18.8%), and C3 (n = 6; 18.8%). The mean delay from injury to operation was 15 (range 1-27) days. Iliac bone graft was performed in four patients. Postoperatively, a posterior splint or a plaster cast was applied for 3 weeks. No patient had an intra-articular step-off of more than 2 mm. Sepsis of the operative wound occurred in two patients. Fractures healed in 22 (91.7%) patients with a mean duration of 4 (range 3-8) months. Twenty-four patients were followed up on an average of 15 (range 7-28) months. Varus deformity (>10°) was observed in five (20.8%) patients. Knee flexion was less than 90° in 11 (45.3%) cases. Non-union occurred in two (8.3%) patients. Functional results were good to excellent in 11 (45.8%) patients and considered as fair or failure in 13 (54.2%).

CONCLUSION

The current report also identifies varus deformity as a major concern of this implant. The main finding of this study was the ensuing knee stiffness after a prolonged immobilization and delay in performing surgery and rehabilitation program due to socioeconomic and logistic reasons.

Determination of sagittal alignment measurements in distal femurs

OBJECTIVE

Open reduction and internal fixation is presently the treatment of choice for distal femur fractures. Anatomic reconstruction of the articular surface and restoration of biomechanical relations to the diaphysis are desired. A method to determine sagittal alignment on plain radiographs is warranted.

METHODS

Consecutive adult, normal, distal femur/knee, plain lateral radiographs and scanned and digitalized cadaveric distal femurs were analyzed. Measurement of 7 different angles was performed.

RESULTS

Ninety-four adults [39 men (41.5%) and 55 women (58.5%)] with a mean age of 54 years (range, 18-92 years) and body mass index (BMI) of 29.7 kg/m(2) (range, 16.6-47.2 kg/m(2)), as well and 35 cadaveric femora [24 men (68.6%) and 11 women (31.4%)] with a mean age of 53 years (25-85 years) and BMI of 29.8 kg/m(2) (17.7-53.3 kg/m(2)) were studied. Twenty-two of the patients (23.4%) had radiographic findings of arthrosis. If arthrosis was diagnosed, measurements including the proximal rim of the articular surface were significantly greater (P = 0.001). Two angles were significantly smaller in women (P < 0.05). No significant differences in any measurement for age or BMI were recorded.

CONCLUSIONS

The necessity for reliability and quality of intraoperative and postoperative radiographic controls of the obtained fracture reduction, implant insertion, and final healed fracture increases with popularity of less invasive indirect reduction and stabilization methods. The ability to obtain exact sagittal alignment measurements has been problematic with other studies. Two different and reliable methods of measuring sagittal plane anatomy and measurements independent of implants were confirmed using plain radiographic images.

Outcome of periprosthetic distal femoral fractures following knee arthroplasty

INTRODUCTION

The majority of periprosthetic fractures around the knee occur at the supracondylar region of the distal femur. Fixation of distal femoral fractures in osteoporotic bone with short segment remains a challenge, especially after total knee arthroplasty (TKA). Internal fixation of these fractures using locking plates has become popular. The purpose of this study was to evaluate a consecutive series of periprosthetic supracondylar femoral fractures treated with locked periarticular plate fixation with regard to surgical procedure, complications and clinical outcome.

MATERIALS AND METHODS

From two academic trauma centres, 55 consecutive periprosthetic distal femoral fractures (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association, AO/OTA 33) were retrospectively identified as having been treated with locked plate fixation. Of these, 36 fractures in 35 patients (86.1% female) met the inclusion criteria. Patients had an average age of 73.2 years (range 54-95 years). Fixation constructs for plate length and working length were delineated. Nonunion, infection and implant failure were used as complication variables. Demographics were assessed. Outcome was addressed radiographically and clinically according to Kristensen et al.(1) by range of motion and pain.

RESULTS

Twenty-five of 36 fractures (69.4%) healed after the index procedure. Eight of 36 fractures (22.2%) developed a nonunion with three fractures (8.3%) leading to hardware failure. Nine of the 36 patients (25%) were radiographically diagnosed with notching of the anterior femoral cortex. Regarding technical aspects, distance from the anterior flange of the femoral component to fracture was significantly shorter in patients with compared to without anterior notching (t=3.68, p=0.02). Patients who underwent submuscular plate insertion compared to an extensive lateral approach had a reduced nonunion risk (χ(2)=0.05). No difference in infection rate was found for submuscular procedures compared with open procedures (χ(2)=0.85). Range of motion was reduced in most of the patients and 13.5% had a persistent loss of extension of 5°. More than 77% of the patients reported no or only mild pain during the last office visit. Range of motion loss did not influence pain. Successful treatment according to Cain et al.(2) was achieved in 83%. Using Kristensen's(1) criteria, 56% of the knees had acceptable flexion.

CONCLUSION

Operative fixation of periprosthetic distal femoral fractures after TKA continues to be challenging. Notching of the anterior femoral cortex should be avoided. Loss of reduction and high failure rates still occur with locked plating and may be related to underlying factors. Indirect reduction and submuscular plate insertion technique reduce nonunion risk.

A distal femoral supra-condylar plate: biomechanical comparison with condylar plate and first clinical application for treatment of supracondylar fracture

PURPOSE

An anatomical supra-condylar plate is designed and analysed by biomechanical testing.

METHODS

The biomechanical properties of the supra-condylar and condylar plate were compared in six matched pairs of cadaveric femurs. A transverse osteotomy gap was created to simulate an OTA/AO type A3 supracondylar fracture. The left and right specimens were fitted with supra-condylar and condylar plate, respectively. Nondestructive axial compression, three-point bending and torsion tests were performed, and the peak load of the bone-implant construction was measured. The fracture site suitable for supra-condylar plate application and its correlation with femoral length were calculated. The gender influence on it was also discussed.

RESULTS

The difference of stiffness between the supra-condylar and condyle groups were not significant (P > 0.05) at 363.4 and 362.5 N/mm for compression, 229.5 and 237.6 N/mm in the sagittal plane and 195.5 and 188.4 N/mm in the coronal plane for three-point bending, and 7.5 and 7.9 Nm/deg for axial torsion, respectively. The peak load was 4438 ± 136.15 N and 5215 ± 174.33 N, respectively, for the two groups. The average extent of the fracture site suitable for the application of the supra-condylar plate was 70.86 ± 4.61 mm. The femoral length and gender showed no influence on it.

CONCLUSION

Despite the limited bone contact area provided by the supra-condylar plate, its construct stiffness is comparable to the condylar plate. The supra-condylar plate can be used to treat carefully-selected extra-articular supracondylar fractures.

Indications and limitations of locked plating

The goal of fracture fixation is to achieve bone healing and restore the function of the injured limb in the shortest possible time without compromising safety. Newer technologies such as the locking compression plate (LCP) and its derivatives are valuable additions to the orthopaedic traumatologist's armamentarium. As with any emerging technology, the indications will be extended until a threshold is reached and the limitations of the technology are seen. It is vital that surgeons involved in fracture care are aware of when locked plating is superior to other methods and also when they should use another treatment modality. This paper reviews the use of locked plating as a fixation method. Five topics covered in this review are: a historical perspective on locked plating, general indications, specific modes and techniques, patterns of failure, and an anatomical overview of current indications for locked plating.

Treatment of acute distal femur fractures

An emphasis on indirect reduction techniques to restore limb alignment has improved the rate of fracture healing and decreased infection rates, fixation failure, and the need for bone grafting.

Locked plating in orthopaedic trauma: a clinical update

Locked plating for fracture fixation has enjoyed widespread popularity despite a paucity of published data on outcomes. Anatomically precontoured locked plates that allow fixation in various anatomic regions are widely available. New technologies incorporate subchondral support locking pegs, polyaxial bushings, and locking washers to improve intraoperative versatility. However, limited data are available on the efficacy of these new implants. The clinical performance of locked plates generally has been good. However, several unique complications have been noted, such as difficulty with implant removal, malalignment, fracture distraction, and loss of diaphyseal fixation, especially with percutaneous techniques and unicortical screws. The expense of locked plate constructs is a concern. This technology typically costs three times more than similar unlocked constructs. Locked constructs should be reserved for problematic fractures that have demonstrated poor outcomes with unlocked constructs.

Locking plate technology and its role in osteoporotic fractures

Osteoporosis is a public health issue that leads to increased morbidity and dependency in an increasing population. Fractures in osteoporotic bone have been a contraindication to internal fixation due to their past poor results. Various treatment methods and innovations have been attempted that have met with some success. This paper reviews one such innovation, locking-plate osteosynthesis, looking at its technology and success and its role in osteoporotic patients. As this is an evolving technology, surgeon's experience with these plates and screws are in advance of clinical studies and therefore the surgeons should proceed with caution when choosing locking plate technology in the treatment of osteoporotic fractures.

Fracture healing in osteoporotic fractures: is it really different? A basic science perspective

Osteoporosis is a major health problem characterized by compromised bone strength that predisposes patients to an increased risk of fracture. Osteoporotic patients differ from normal subjects in bone mineral composition, bone mineral content, and crystallinity. Poor bone quality in patients with osteoporosis presents the surgeon with difficult treatment decisions. Much effort has been expended on improving therapies that are expected to preserve bone mass and thus decrease fracture risk. Manipulation of both the local fracture environment in terms of application of growth factors, scaffolds and mesenchymal cells, and systemic administration of agents promoting bone formation and bone strength has been considered as a treatment option from which promising results have recently been reported. Surprisingly, less importance has been given to investigating fracture healing in osteoporosis. Fracture healing is a complex process of bone regeneration, involving a well-orchestrated series of biological events that follow a definable temporal and spatial sequence that may be affected by both biological factors, such as age and osteoporosis, and mechanical factors such as stability of the osteosynthesis. Current studies mainly focus on preventing osteoporotic fractures. In recent years, the literature has provided evidence of altered fracture healing in osteoporotic bone, which may have important implications in evaluating the effects of new osteoporosis treatments on fracture healing. However, the mechanics of this influence of osteoporosis on fracture healing have not yet been clarified and clinical evidence is still lacking.

Biomechanical analysis of distal femur fracture fixation: fixed-angle screw-plate construct versus condylar blade plate

OBJECTIVE

The objective of this study is to establish the relative strength of fixation of a locking distal femoral plate compared with the condylar blade plate.

METHODS

Eight matched pairs of fresh-frozen cadaveric femurs were selected and evaluated for bone density. A gap osteotomy model was used to simulate an OTA/AO A3 comminuted distal femur fracture. One femur of each pair was fixed with the blade plate; the other, with a locking plate. After 100 N preload and 10,000 cycles between 100 N and 1000 N, total displacement of each specimen was assessed. After completion of cyclic loading, maximum load to failure was tested.

RESULTS

Significantly greater subsidence (total axial displacement) occurred with the blade plate (1.70 +/- 0.45 mm; range, 1.21-2.48 mm) than with the locking plate fixation (1.04 +/- 0.33 mm; range, 0.67-1.60 mm) after cyclic loading (P = 0.03). In load-to-failure testing, force absorbed by the locking plate before failure (9085 +/- 1585 N; range, 7269-11,850 N) was significantly greater than the load tolerated by the blade plate construct (5591 +/- 945 N; range, 3546-6684 N; P = 0.001). Variability in bone mineral density did not affect the findings (fixed angle distal femoral plate r = 0.1563; condylar blade plate r = 0.0796).

CONCLUSIONS

The locking screw-plate construct proved stronger than the blade plate in both cyclic loading and ultimate strength in biomechanical testing of a simulated A3 distal femur fracture. Although differences were small, the biomechanical performance of the locking plate construct over the blade plate may lend credence to use of the locking plate versus the blade plate in the fixation of comminuted distal femur fractures.

Arthroscopy-assisted minimally invasive removal of a plate in the distal femur

We developed an arthroscopy-assisted minimally invasive procedure for removal of a plate in the distal femur. Under arthroscopic assistance, we made an arthrotomy in the middle of the screws attached to the plate in the knee joint; all screws were removed, except for those placed proximally that were too difficult to remove. An approximately 5-cm skin incision (the distal one half to one third of it was near the proximal end of the knee cavity) was made through the old incision scar under arthroscopic assistance, and visible screws were removed. Proximal screws that were not visible through this incision were removed percutaneously through new small stab incisions placed midway between every 2 screws under the control of an image intensifier. Then, a small arthrotomy was made through the distal portion of the approximately 5-cm incision, at the place where the plate entered the knee joint. Through this arthrotomy, any screws still attached to the plate within the knee joint were removed. Then, the plate was stripped from the distal femur, was pulled proximally, and was removed without difficulty. With the use of this procedure, we can concomitantly assess the condition of the intra-articular region.

Principles of fixation of osteoporotic fractures

Despite advances in the prevention and treatment of osteoporotic fractures, their prevalence continues to increase. Their operative treatment remains a challenge for the surgeon, often with unpredictable outcomes. This review highlights the current aspects of management of these fractures and focuses on advances in implant design and surgical technique.