Abstract. Objective. To compare the clinical and radiological outcome between less invasive stabilization system (LISS, Synthes, Paoli, PA.) and open reduction with internal fixation (ORIF) for the treatment of extraarticular proximal tibia fractures through the lateral approach. Background. Proximal tibial fractures present a difficult treatment challenge with historically high complication rates. ORIF has been in vogue for long time with good outcome. But these are associated with problems especially overlying skin conditions, delayed recovery and rehabilitation with limited functional outcome. LISS is an emerging procedure for the treatment of proximal tibial fractures. It preserves soft tissue and the periosteal circulation, which promotes fracture healing. Patients and methods. Thirty patients with closed proximal tibial fractures were included in this study. They were randomly divided into 2 groups. Group I (n=15) patients were treated by LISS and group II (n=15) by ORIF. Major characteristics of the two groups were similar in terms of age, sex, mode of injury, fracture location, and associated injuries. All patients were followed up at least 6 months. Results. In each group, 12 patients were united, 2 patients were non- united and one patient showed delayed union. The mean operative time in LISS patients was 79.3 min, while in ORIF patients; it was 122 min. All patients of LISS group were exposed to radiation, while only 40% of ORIF group were exposed. The mean time of union of LISS patients was 10.87weeks. While in ORIF patients, the mean time of union was 21.13 weeks. There was no significant difference between both groups regarding the postoperative complications. Functional outcome was satisfactory in both groups. Conclusion. LISS achieves comparable results with ORIF in extraarticular fractures of the proximal tibia. Although LISS potentially has the radiation hazard, it reduces the perioperative complications with a shortened operation time and minimal soft tissue dissection. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction. Being challenging, multifragmentary proximal tibial fractures in patients with severe soft tissue injuries and/or short stature can be treated using externalized locked plating. A recent finite element study, investigating the fixation stability of plated unstable tibial fractures with 2-mm, 22-mm and 32-mm plate elevation under partial and full weight-bearing, reported that from a virtual biomechanical point of view, externalized plating seems to provide appropriate relative stability for secondary bone healing under partial weight-bearing during the early postoperative phase. The aim of the current study was to evaluate the clinical outcomes of using a LISS plate as a definitive external fixator for the treatment of multifragmentary proximal tibial fractures. Methods. Following appropriate indirect reduction, externalized locked plating was performed and followed up in 12 patients with multifragmentary proximal tibial fractures with simple intraarticular involvement and injured soft tissue envelope. Results. Among all patients, the average follow up period was 22 months (range14–48 months), revealing uneventful healing in all of them. Time to fracture union was 21.8 weeks on average (range 16–28weeks). The mean HSS knee score was 87 (range 72–98) at 4 weeks postoperatively and 97 (range 88–100) at the final follow up. The average AOFAS score was 92 (range 84–100) at 4 weeks postoperatively and 98 (range 94–100) at the final follow up. Conclusions. Externalized locked plating seems to be a successful surgical alternative treatment in selected cases with unstable proximal tibial fractures and severe soft tissue injury, following appropriate indirect fracture reduction

Introduction. The incidence of distal femoral fractures in the geriatric population is growing and represents the second most common insufficiency fracture of the femur following fractures around the hip joint. Fixation of fractures in patients with poor bone stock and early mobilisation in feeble and polymorbide patients is challenging. Development of a fixation approach for augmentation of conventional LISS (less invasive stabilization system) plating may result in superior long-term clinical outcomes and enhance safe weight bearing. Objectives. The aim of this study was to investigate the biomechanical competence of two different techniques of augmented LISS plating for treatment of osteoporotic fractures of the distal femur in comparison to conventional LISS plating. Materials & methods. Unstable distal femoral fracture AO/OTA 33-A3 was set in artificial femora with low density simulating osteoporotic bone. Three study groups, consisting of 10 specimens each, were created for instrumentation with a 9-hole LISS plate, a LISS plate with an additional 3D-printed polyactide cylindrical intramedullary graft, as well as a LISS plate plus a medial 3.5mm LCP (locking compression plate) - double plating. All specimens were non-destructively tested under axial (20–150N) and torsional (0–4Nm) quasi-static loading. Each 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. Results. Interfragmentary displacement along the femur axis (mm) under 150N axial loading was 2.03±0.23/1.65±0.27 for LISS with long/short WL, 0.18±0.06/0.18±0.04 for double plating with long/short WL, and 0.40±0.05/0.30±0.05 for LISS plus graft with long/short WL. Shear interfragmentary displacement (mm) under 4Nm torsional loading in internal rotation was 1.16±0.17/0.92±0.11 for LISS with long/short WL, 0.40±0.10/0.43±0.07 for double plating with long/short WL, and 1.09±0.13/0.82±0.11 for LISS plus graft with long/short WL. Double plating revealed significantly smaller longitudinal and shear displacement compared to the other two techniques for long and short WL, respectively (P≤0.010). In addition, LISS plus graft fixation was with significantly less longitudinal displacement in comparison to conventional LISS plating for long and short WL, respectively (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=1.000). Conclusion. Intramedullary grafting resulted in significantly increased fracture stability under axial loading in comparison to conventional LISS plating. However, it was not efficient enough to achieve comparable stability to double plating

Aims

Fractures of the distal femur can be challenging to manage and are on the increase in the elderly osteoporotic population. Management with casting or bracing can unacceptably limit a patient’s ability to bear weight, but historically, operative fixation has been associated with a high rate of re-operation. In this study, we describe the outcomes of fixation using modern implants within a strategy of early return to function.

Aims

Computer hexapod assisted orthopaedic surgery (CHAOS), is a method to achieve the intra-operative correction of long bone deformities using a hexapod external fixator before definitive internal fixation with minimally invasive stabilisation techniques.

The aims of this study were to determine the reliability of this method in a consecutive case series of patients undergoing femoral deformity correction, with a minimum six-month follow-up, to assess the complications and to define the ideal group of patients for whom this treatment is appropriate.

We investigated a new intramedullary locking nail that allows the distal interlocking screws to be locked to the nail. We compared fixation using this new implant with fixation using either a conventional nail or a locking plate in a laboratory simulation of an osteoporotic fracture of the distal femur. A total of 15 human cadaver femora were used to simulate an AO 33-A3 fracture pattern. Paired specimens compared fixation using either a locking or non-locking retrograde nail, and using either a locking retrograde nail or a locking plate. The constructs underwent cyclical loading to simulate single-leg stance up to 125 000 cycles. Axial and torsional stiffness and displacement, cycles to failure and modes of failure were recorded for each specimen. When compared with locking plate constructs, locking nail constructs had significantly longer mean fatigue life (75 800 cycles (sd 33 900) vs 12 800 cycles (sd 6100); p = 0.007) and mean axial stiffness (220 N/mm (sd 80) vs 70 N/mm (sd 18); p = 0.005), but lower mean torsional stiffness (2.5 Nm/° (sd 0.9) vs 5.1 Nm/° (sd 1.5); p = 0.008). In addition, in the nail group the mode of failure was either cut-out of the distal screws or breakage of nails, and in the locking plate group breakage of the plate was always the mode of failure. Locking nail constructs had significantly longer mean fatigue life than non-locking nail constructs (78 900 cycles (sd 25 600) vs 52 400 cycles (sd 22 500); p = 0.04).

The new locking retrograde femoral nail showed better stiffness and fatigue life than locking plates, and superior fatigue life to non-locking nails, which may be advantageous in elderly patients.

Cite this article: Bone Joint J 2014;96-B:114–21.

Introduction. The most common treatment options for fixation of osteoporotic distal femur fractures are retrograde nails and locking plates. There are proponents of more elastic titanium plates as well as more rigid steel plates; No clear superiority of one over the other has been established. We aimed to evaluate the mechanical differences between stainless steel and titanium locking plates in the fixation of distal femur fractures in osteoporotic bone. We hypothesized that due to its higher elasticity titanium locking plates can absorb more energy and are therefore less likely to “cut” into the bone compared to stainless steel locking plates resulting in improved metaphyseal osteoporotic fracture fixation. Methods. We used eight matched pairs of osteoporotic fresh-frozen human cadaveric femurs (age >70 years, all female). Within each pair we randomized one femur to be fitted with a Less Invasive Stabilization System (LISS-Titanium locking plate) and one with a Distal Locking Condylar Plate (DLCP-Stainless steel locking plate). A fracture model simulating an AO 33-A3 fracture was created (extraarticular comminuted fracture) and specimens were subsequently subjected to step-wise cyclic axial loading to failure. We used an advanced three dimensional tracking system (Polhemus Fastrak) to monitor the movement of the distal fragment relative to the real time distal plate position allowing us to evaluate distal implant cut-out. Results. During cyclic testing, seven of the eight pairs of matched femurs, the DLCP failed before the LISS plate (p=0.03). All constructs were able to withstand cyclical loading up to 800N. The overall plastic deformation as measured by the displacement of the Instron crosshead experienced by the titanium plate constructs was significantly lower compared to the stainless steel plate construct: The plastic deformation of the LISS plates was 39% lower compared to the Locking Condylar plates after cycle testing at 400 Newtons and 70% lower at 800N. Furthermore during the 800N cycle testing the LISS plating system showed a significantly lower rate of plastic deformation not only for the entire bone-implant construct, but also between the plate and the distal fragment than the locking condylar plate (=less distal implant cut-out). Conclusions. The use of a more advanced three dimensional tracking system, fresh-frozen osteoporotic matched human specimen and the ability to test all constructs to failure allowed us a more thorough comparison of titanium versus stainless steel implants compared to previous studies. The titanium locking plates provided an overall superior fixation of osteoporotic distal femur fractures with less distal implant cut-out, a better elastic recoil, and a slower rate of residual plastic deformation

Massive segmental bone defects in long bones remain a considerable clinical challenge and are a source for significant morbidity and prolonged dysfunction for the patient. We demonstrate the successful use of resorbable polylactide membranes as a scaffold for autologous bone graft in the treatment of a 10cm traumatic femoral bone defect. A 28-year-old male was involved in a motorcycle accident vs. tree at 140k/hr. He sustained a Gustillo grade 3b intercondylar fracture of his right femur, and a 10cm piece of his femoral bone found at the scene was brought to Emergency in a sterile container. He was taken to theatre for debridement and ORIF of the intercondylar fracture, with vacuum dressing cover. Day 5 post injury the patient returned to theatre and the LISS plate was revised to correct the rotation and 3cm shortening. The 10cm cortical defect now present was filled with antibiotic cement (Palacos) and delayed primary closure was performed. Day 21 post injury the cement spacer was removed and replaced with two polylactide membrane tubes, one within the medullary canal and the other around the outside of the bone. The “neocortical” space thus produced was grafted with cancellous autograft mixed with bone morphogenic protein (OP1, Stryker). The remainder of the post-operative course was uncomplicated and the patient was discharged home 5 days later. The patient was reviewed at the 6 week and 3 month mark post injury. The femoral defect demonstrated both radiological and clinical union at the 3 month mark and full weight bearing was permitted. His range of motion at that stage was 5 to 95 degrees with no sign of infection. The use of polylactide membranes as a scaffold in the treatment of segmental long bone defects is an excellent and relatively straightforward technique. Forming a space between the 2 tubes controls cancellous graft to the site of the cortical area where it is required and the polylactide membrane then resorbs over years producing CO2 and water. This case demonstrates that the use of polylactide membranes is safe and effective in the management of segmental long bone defects

Vancouver B type peri-prosthetic hip fractures are increasingly common and represent a very complex and challenging problem in terms of management. Plate fixation has not always succeeded, and revision hip arthroplasty on a suboptimal trauma list can be a daunting prospect. Our technique is to use the opposite sided distal femoral LISS plate, inserted from proximally to distally in an inverted manner. Vastus lateralis is elevated off the trochanteric ridge, and a small amount of bone is removed from the ridge to get the plate to sit snugly. The fracture is opened only enough to achieve reduction, and fixation with locking screws are placed percutaneously distal to the fracture. Bone grafting or cable fixation can also be applied at the fracture site. 20 consecutive patients with Vancouver B peri-prosthetic hip fractures were reviewed. The average patient age was 78 yrs. 14 fractures occurred in cemented and 6 in uncemented femoral stems. 12 fractures occurred in primary THR and 8 in bipolar hip hemiarthroplasty. Six were managed using the inverted LISS plate, 6 using other methods of fixation, and 8 with revision THR. In terms of mortality at 12 months, there was no difference between the treatment arms, with 1 death in the LISS and other fixation group respectively and 0 deaths in the revision THR group. From a morbidity perspective there was no difference with respect to post-op medical complications, weight bearing status and length of hospital stay. There was, however, a difference between the inverted LISS plate group and other fixation methods group compared with the revision THR group in terms of average transfusion requirement (2 units and 3 units vs 8 units) and average operative time (80 mins and 100 mins vs 465 mins). 1 LISS plate failed in the 12 month period, with 1 Revision THR and 2 from the other fixation group. This study suggests that it is a stable method of fixation, particularly in the type B1 and B2 subtypes. It may also be used in patients with multiple co-morbidities who cannot undergo a revision procedure and in patients who are minimally/non ambulant. In one patient, we used it to stabilize the fracture before progressing to a later, more controlled, revision hip replacement situation. LISS fixation has a short operative time, low transfusion requirement, low failure rate and is technically easier to perform than revision surgery

We retrospectively reviewed 101 consecutive patients with 114 femoral tumours treated by massive bone allograft at our institution between 1986 and 2005. There were 49 females and 52 males with a mean age of 20 years (4 to 74). At a median follow-up of 9.3 years (2 to 19.8), 36 reconstructions (31.5%) had failed. The allograft itself failed in 27 reconstructions (24%).

Mechanical complications such as delayed union, fracture and failure of fixation were studied. The most adverse factor on the outcome was the use of intramedullary nails, followed by post-operative chemotherapy, resection length > 17 cm and age > 18 years at the time of intervention. The simultaneous use of a vascularised fibular graft to protect the allograft from mechanical complications improved the outcome, but the use of intramedullary cementing was not as successful.

In order to improve the strength of the reconstruction and to advance the biology of host–graft integration, we suggest avoiding the use of intramedullary nails and titanium plates, but instead using stainless steel plates, as these gave better results. The use of a supplementary vascularised fibular graft should be strongly considered in adult patients with resection > 17 cm and in those who require post-operative chemotherapy.

Objectives

We aimed to further evaluate the biomechanical characteristics of two locking screws versus three standard bicortical screws in synthetic models of normal and osteoporotic bone.

The distal femur fracture is a difficult injury that affects young men andelderly women. The tissue stripping that occurs with the traditional approach has been a factor in the development of complications like infection and nonunion. This study addresses the issue of minimally invasive approach. Does the LISS system really improve the results of such fracture?. Fifty-two patients were included in the trial from six academic trauma centres. Twenty-eight fractures had been randomised to be fixed with the LISS device, while twenty-four had the DCS implant. Type C3 fractures were excluded as they were not amenable for fixation with DCS system. All procedures were performed via minimally invasive technique. The LISS system had the targeter that helped with plate insertion and distal diaphyseal screws placement. Radiography was utilised in the case of the DCS distal screws insertion. All fractures went onto union, except two participants in LISS group who had to be revised due to loss of reduction, in the early post-operative peroid. There were three nonunions in the same group. These required a re-operation. Further more, a LISS participant who had re-injured his distal femur (unrelated to LISS plate), was fixed with different implant. There was a single nonunion with the DCS group that needed revision surgery. There was one participant from each group who had drifted into varus. Neither required a re-operation. This translated into a 21% re-operation rate in the LISS system compared to 4% with the DCS device. Our data supports the use of the DCS system in the fixation of distal femur fractures (except Type C3} via a minimally invasive approach. The LISS implant seems to be technique dependent. In our centre, the LISS plate had been discontinued in favour of the DCP and LCP systems

Introduction. The treatment of distal femoral fractures has undergone several changes during the past century, from non-operative techniques to more recently minimally-invasive internal fixation. The Less Invasive Stabilisation System (LISS) is an internal fixation plate that combines closed fixation of the distal femur using an anatomically pre-contoured plate with locked unicortical screws. Study aim. The purpose of this multicentre study was to review the use of the LISS plate in three regional centres with respect to fracture healing between different severities of fractures. Materials and methods. Patients treated with a LISS plate for a distal femoral fracture (AO/OTA Type 33A1 to 33C3) between 1st January 2004 and 1st June 2008 were recruited. Demographic data plus mechanism of injury, type of fracture, injury severity scores (ISS) and complications were documented. Subgroup statistical analysis using SPSS for Windows v. 17 was conducted to determine differences in the mean ISS, operating time, length of hospitalisation and ultimately, the time taken for union between groups of different fracture severities (Type 33A vs. Type 33C fractures). A P value of less than 0.05 was considered to be significant. Results. Across the 3 regional centres, a total of 88 patients presented with a distal femoral fracture, of which 44 were treated with a LISS plate. The mean age of the patients was 66.1 (range 9 - 99), with 15 males and 29 females. There were 14 Type 33A1, 13 Type 33A2, 6 Type 33A3, 1 Type 33B2, 1 Type 33C1, 5 Type 33C2 and 4 Type 33C3 fractures. Union was achieved within an average of 14.7 weeks (range 8 - 25) in 33 cases. Five cases exhibited non-union and were managed by a retrograde nail or another locking compression plate. Six cases developed delayed union. Subgroup analysis revealed that patients with Type 33C (n = 10) fractures presented with a significantly greater mean ISS score (12.7 vs. 10.0, p = 0.031), endured longer operating time (203.7 minutes vs. 125.8 minutes, p = 0.016) and spent longer in hospital compared to Type 33A (n = 33) fractures (35.3 days vs. 12.5 days, p = 0.004). However, no difference in the mean time for radiological union between the groups was observed (16.4 weeks vs. 13.6 weeks, p = 0.058). Discussion. We observed an overall success rate of 75% (33 out of 44 cases) as fractures reached radiological union within an average of 14.7 weeks. Interestingly, despite a greater mean ISS score and operating time among Type 33C fractures, the subgroup analysis confirmed that the LISS plate is a robust treatment option across all fracture severities, as this did not translate as longer time to union compared to Type 33A fractures. However, there were 5 cases of non-union and 6 cases of delayed union in our series. These may have arisen due to lack of precision in surgical technique, as we observed 8 cases of suboptimal implant positioning. Three cases involved distal screws lacking contact with the medial cortex of the femur. Overall, our data suggest a favourable outcome for the LISS plate in the treatment of distal femoral fractures

Purpose: surgical fixation distal femoral fractures has been associated withnonunion and varus collapse. the soft tissue stripping esulted from this fracture and caused by the surgical approach have been factorassociated with delayed union and infection. the limited soft tissue exposure has been lauded as a solution to this fracture. however, it has occurred with new fixation as well (locked plate) this study is an attempt to look at the fixation from the surgical approach prospective. does the liss system improve the results of this difficult fracture? is there truly a difference in the outcome of this fracture utilizing the locked plate system or the percieved difference due to surgical mini invasive approach. Method: one hundred and forty patientswere screened, and only 53 were randomized and treated in six academic centers over five years. all c3 fractures were excluded from the study as they were felt not to be treatable by the dcs device, but they were treated and fixed appropiately. thirty five females and 18 males were included and appropiately randomized. Results: fifty three patients were randomized, 28 had the liss implant while 25 had the dcs utilized. there were three nonunions in the liss group, plus two patients required an early reoperation in the early post operative periods ( second – fifth post op. day) due to an early loss of reduction. further more, one patient developed a knee arthrofibrosis that required arthroscopic joint release with subsequent implant failure. that necessiated a reoperation. in the dcs group there was only one nonunion, that required reoperation. this translated into reoperation rate of 21%in the liss group compared to 4% with dcs. Conclusion: this prospective multicenter randomized trial showeda significant difference when comparing the liss device to the dcs system in minimal invasive approach of distal femoral fractures fixation

Introduction: Surgical fixation of intra-articular distal femoral fractures has been associated with nonunion & varus collapse. The soft tissuestripping associated with this fracture andthe surgical exposure have been factors associated with delayed union & infection. The limited soft tissue exposure has been lauded the as a solution to this fracture. However, it has occurred with the new fixation as well.(Locked Plate). Aims: This study is an attempt to look at the fixation. Does the LISS system improve the results of this difficult fracture? Is there truly a difference in the outcome of this fracture utilizing the Locked plate system or is the percieved difference due to the surgical mini invasive approach. Patients & Methods: One hunderd & forty patients were screened, only 53 were randomized and fixed in six academic centers over 5 years. All C3 fractures were excluded as they were felt not to be treatable by the DCS device, but they were treated appropiately. 35 females and 18 males were included in the study and randomized appropiatley. Results: Fifty-three patients were randomized, 28 had the LISS implant and 25 had the DCS utilized. There were 3 nonunions in the LISS group plus two patients with early loss of reduction that required reoperation in the early post operative period. One patient developed arthrofibrosis requiring arthroscopic release and subsequently the implant failed necessitating refixation. In the DCS group, only one nonunion reported & required second surgery. This translated to a reoperation rate of 21% in the LISS group compared to 4% with DCS. Conclusion: This prospective randomized multicentre trial showed a difference when comparing the LISS to the DCS in the supracondylar distal femur fractures

Purpose: To compare locking and non-locking single and dual plating constructs in maintaining posteromedial fragment reduction in a bicondylar tibial plateau fracture model. We hypothesized that posteromedial fragment fixation with medial and lateral non-locked constructs would tolerate higher loads than lateral locked constructs alone. Method: Thirty adult-sized composite tibiae were identically fractured into an AO 41-C1.3 pattern. Six plate constructs were tested:. lateral 8-hole 3.5 mm conventional non-locking proximal tibial plate [CP];. CP + posteromedial 6 hole 3.5 mm limited contact dynamic compression plate [CP + LCDCP];. CP + postero-medial 6 hole 1/3 tubular plate [CP + 1/3 tubular];. 8-hole 3.5mm Proximal Tibial Locking plate [PTLP];. 8-hole 3.5 mm LCP (locking compression plate) proximal tibia plate [LCP];. 9-hole Less Invasive Stabilization System [LISS] plate. Specimens were cyclically loaded to failure or a maximum load of 4000N. Load at posteromedial fragment failure was recorded. Results: Fragment failure occurred at the posteromedial fragment first. The CP + 1/3 tubular construct had the highest average load to failure (3040 N). In two instances, the CP + 1/3 tubular construct did not fail under the highest loads applied and was the only construct to have specimens that did not fail by 4000 N. The CP + 1/3 tubular plating construct demonstrated significantly higher load at failure compared with the PTLP (p=0.036), the LCP (p=0.004), and the LISS (p=0.012). The CP + 1/3 tubular group did not demonstrate a significant difference in load at failure when compared with the CP (p=0.093) or the CP + LCDCP (p=0.108). The LISS demonstrated a significantly higher load at failure compared to the LCP (p=0.046) but not to the PTLP (p=0.800). Conclusion: The posteromedial fragment tolerated higher loads with the CP + 1/3 tubular plate construct. The superiority of the dual plate construct may in part be due to the unreliable penetrance of the posteromedial fragment by the laterally applied locking screws

This multi-center randomized prospective trial examined fixation for distal femoral fractures by standardizing the surgical approach as minimally invasive. Fifty three patients at six Canadian trauma centers were randomized via the Lead Centre (Halifax Infirmary, Dal-housie University, Halifax, CANADA) into 2 groups of 28 LISS and 25 DCS respectively. The AO C3 group was excluded from randomization. In the LISS group, three fractures went on to non-union and two fractures were complicated by early loss of fixation. A further LISS patient had removal of all metalwork when removal of individual prominent screws proved impossible due to cold-welding. In the DCS group, one fracture was complicated by non-union. The difference between the two groups proved very statistically significant. (P< 0.05). In this trial, the LISS proved more technically demanding and a higher re-operation rate was evident. At the Lead Centre, the LISS has been abandoned in favor of the DCS or LCP Condylar Plate performed via a minimally invasive approach

Background: Aim of this study was to evaluate and compare clinical and radiological outcome of distal femur fracture stabilization using retrograde nailing or LISS plating. Materials and Methods: In a retrospective study from 2003–2008 we analyzed 115 patients with distal femur fractures who had been treated by retrograde i.m. nailing (60 patients) or LISS plating (55 patients). Mean age was 55 years in the two cohort groups. Mechanism of injury was high energy impact in 57 % (SCN 53 %; LISS 76 %) and low energy injury in 43 % of all evaluated patients (SCN 47 %; LISS 33 %). Fractures were classified according to AO classification: There were 52 type A fractures (SCN 31; LISS 21) and 63 type C fractures (SCN 28; LISS 35). Interestingly severe articular fractures (type C2 and C3) were found much more often in LISS group (15 patients; 27 %) compared to 5 patients (8 %) in the SCN group. Results: Fracture healing within 3 months was observed in type A fractures in over 90 % of the cases (SCN 29 patients, 89 %; LISS 20 patients, 95 %). A distinct diffrence was found in type C fractures. Whereas still nearly 90 % consolidation was evaluated in the SCN group (25 patients; 89 %), LISS plate group showed only 41 % (14 patients). Nonunion was found in type A fractures in only one patient per group (SCN and LISS 3 %) and in 2 patients in type C fractures treated with SCN (7 %). As expected 35 % (11 patients) nonunions were found in type C fractures treated with LISS. Both, the nail and the LISS group required additional bone grafting for successful healing (SCN 2; LISS 8). Functional outcome using the KOOS score demonstrated in type A fractures a score of 263 in the nail and 260 in the LISS plate group, and in type C fractures 257 in the nail and 218 in the LISS group. Loosening of screws without disturbing fracture healing (SCN 12 %; LISS 2 %). Deep infection (SCN 2 %; LISS 7 %), axis deviation of more than 10 degrees in the coronal or sagittal plane in 5 % in the nail and 12 % in the plate group were treated. Conclusion: Both, retrograde i.m. nailing and LISS plating are adequate treatment options for distal femur fractures. No differences in outcome between implants regarding fracture healing, nonunion, and infection were found in type A fractures. A distinct difference occurred in type C fractures. According to high rate of severe articular and open fractures a high rate of nonunions and infections was found in the LISS group. Locked plating can be utilized for all distal femur fractures including complex type C fractures, periprosthetic fractures and osteoporotic fractures. I.m. nailing provides favorable intramedullary stability and can be successfully implanted in bilateral or multisegmental fractures of the distal femur as well as in extraarticular and type C1 to C2 fractures

Despite advances in Locking Plate (LP) design, distal femoral fractures remain challenging injuries to treat especially in the elderly where approximately 15–30% develop nonunions secondary to failure of fixation. Aim: To establish the mechanisms of nonunion in our patient population using two different LP systems. Methods: Between December 2002-May 2008, we prospectively collected data on all 67 patients with distal femoral fractures who were treated using a suitable distal femoral LP (LISS, 35 cases, or Periloc, 32 cases). 72% of the patients were female; ages ranged from 25–94 years (ave. 67 years). Many of our patients had a number of significant co-morbidities. Results: The presence of significant co-morbities e.g. Rheumatoid arthritis, long term systemic steroid use, cerebrovascular accidents resulting in ambulatory problems, previous major joint arthroplasty including ipsilateral knee replacements, paralysis, and severe dementia, did not appear to influence fracture union significantly. However, old age was strongly correlated with nonunion with all failed cases (7 patients - 10% of the study group) presenting with failure of fixation. 2 of the LP system failures resulted in malunion and the 5 other cases required revision surgery. Of note, all 7 patients were elderly, 6 being over 80 years of age. The mechanism of fixation failure was specific to each of the LP systems. All 4 of the failures treated with LISS, resulted from poor proximal stability as a consequence of unicortical screw fixation. Two patients required to have the proximal fixation revised through the insertion of bicortical screws which subsequently resulted in successful union. The other two patients were treated in long leg casts as the varus deformities were considered acceptable given each patient’s needs. All 3 of the failures who had been treated with a Periloc LP, resulted from fracturing of the plate at the metaphyseo-diaphyseal junction at the level of the main extra-articular component of the fracture. The plates all fractured through the unfilled screw holes, and all 3 patients required revision of fixation to bring about union. Discussion: The LISS failures can all be attributed to poor proximal fixation that is associated with the use of unicortical screws in osteoporotic bone and confirms the need for bicortical screw fixation. However, modern LP systems manufactured from stainless steel offer increased implant stability that may in turn stress any fracture bridging segments of the LP. Conclusion: Although we are aware of the importance of bicortical screws in osteoporotic patients, it is also seems likely that excessive plate rigidity should be avoided, by using long plates with well spaced out screws