Less Invasive Stabilization System Plate Research Articles

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

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

Evaluation of the Results of Minimally Invasive Plate Osteosynthesis Using a Locking Plate in the Treatment of Distal Femur Fractures.

IntroductionDistal femur fractures are serious injuries that can be difficult to treat, carry an unpredictable prognosis, and lead to long-term disability and morbidity. The introduction of minimally invasive plate osteosynthesis (MIPO) avoids direct exposure of the fracture site, improves fracture healing and decreases the incidence of complications. The aim of this study was to assess prospectively the early results of the treatment of supracondylar fractures of the femur using minimally invasive percutaneous osteosynthesis using a distal femoral locking plate. The study was a prospective study that included 20 adult patients who sustained distal femur fractures.Materials and methods The study was a prospective study that included 20 patients suffering from supracondylar fractures of the femur. All patients had fixation of the fracture using a distal femur locking plate (less invasive stabilization system (LISS)) in a minimally invasive technique using an anterolateral or direct lateral approach to the distal femur according to the fracture classification. The follow-up was done using the functional evaluation scale for distal femoral fractures as regards range of motion, deformation, pain, walking ability, and return to work.ResultsThe mean age was 52.80 (19-80) years. The mean body mass index of the patients was 28.50, with a range of 23-43 kg/m2. The mechanism of trauma was road traffic accidents (RTAs) in nine patients (45%) and falling from standing height in eleven patients (55%). Fractures were classified according to the Arbeitsgemeinschaft Osteosynthesefragen-Orthopedic Trauma Association (AO-OTA) classification. All patients were followed up for a period of six months and assessed in terms of knee range of motion, deformation, pain, walking ability, and return to work. The mean time of radiological union, in which bony trabeculae crossed the fracture gap, was 3.45 ± 0.79 months. The final results obtained were excellent in four patients (20%), good in nine patients (45%), fair in five patients (25%), and poor in two patients (10%). Complications encountered were knee stiffness (20%), superficial wound infection (10%), and shortening (15%).ConclusionLISS plating using the MIPO approach is useful in treating complex distal femoral fractures. Large studies from independent centers reporting long-term results are needed to further evaluate the role of LISS plating and the MIPO approach in the management of complex distal femoral fractures.

Treatment of Periarticular Fractures of the Knee Using the Less Invasive Stabilization System: A Retrospective Clinical Trial.

IntroductionPeriarticular fractures of the knee in adults are generally treated with internal fixation. The Less Invasive Stabilization System (LISS) plate, developed by Arbeitsgemeinschaft Osteosynthesefragen (AO)/Association for the Study of Internal Fixation (ASIF) in the late 1990s, allows reduction and biological fixation through smaller incisions without violating periosteal blood supply. It offers several advantages for the treatment of complex periarticular fractures of the knee. In this study, we have aimed to report the results of a single series of these fractures.Materials and methodsForty-eight patients with AO type 33 and AO type 41 periarticular knee fractures who were operated between 2009 and 2014 at a single institution were included in this retrospective study. Patient demographics, fracture epidemiology, intraarticular extension, concomitant injuries, American Society of Anesthesiologists (ASA) score, time to union, the average time from admission to surgery, and the mean time from operation to patient discharge were noted. The effect of patient and fracture-related factors on length of hospital stay were evaluated.ResultsThe mean follow-up time was 23.7 (12-48) months. The average time from admission till surgery and from surgery till discharge was 10.2 (1-39) and 9.7 (2-35) days, respectively. The average time for union was 6.8 months. Femur fractures healed in mean 6.6 months whereas tibia fractures took 7.1 months to heal. Time from admission to surgery and postoperative hospital stay was longer in patients with higher ASA scores (p<0.01) and open fractures (p<0.001). Patients’ body mass index (BMI) and intraarticular extension of the fracture did not cause an increase in either preoperative or postoperative hospital stay (p>0.05). The presence of concomitant major injuries caused a delay in operation (p<0.05), whereas postoperative hospital stay was not different (p>0.05).ConclusionLISS plating provides good stability through a small incision, permits biological fracture healing, may be used in multifragmentary fractures and has low complication rates. It is a good alternative for the treatment of periarticular fractures of the knee.

Identification of the lateral femoral safe zone for drilling during LISS plate fixation of distal femur fractures

BackgroundThe incidence of arterial injury associated with femoral fractures is approximately 1%. Lateral sub-muscular plate fixation is gaining popularity for the management of distal femoral fractures. The objective of this study was to assess the iatrogenic risk to the superficial femoral artery (SFA) during Less Invasive Stabilisation System (LISS) plate fixation of distal femoral fractures by analysing the range of distances and angles between LISS plate screws and the drilling line to the SFA. Materials and methodsWe identified all patients who underwent LISS plate fixation of distal femoral fractures between 2008 and 2018 in our level-1 trauma centre. Patients who underwent postoperative computed tomography for any reason were eligible for inclusion in the study. Twenty-five patients met the inclusion criteria. The sample comprised 10 male and 15 female patients with a mean age of 55 years. The most common fracture type was a supracondylar femur fracture (56%), followed by an intercondylar fracture (36%). A 13-hole LISS plate was the most common plate length used (44%). A consultant radiologist reviewed all scans to verify the visibility and marking of the SFA. ResultsThe median distance between the screw tip and the SFA was 21 mm (range, 8–65 mm). There was a negative correlation between the LISS plate hole number and the trajectory of drilling (Pearson coefficient: −0.87, p < 0.001). Using a linear regression model, the SFA was more likely to be in the line of drilling when the 6th to 10th holes in the LISS plate were used. ConclusionExtra care is needed when drilling into the LISS plate holes from the lateral to the medial direction in order to reduce the risk of iatrogenic injury to the SFA, especially in the high-risk plate zone where the artery can be close to the drilling line.

Early effectiveness of mini-Swashbuckler approach for distal femoral type C fractures

To explore the early effectiveness and advantages of mini-Swashbuckler approach in treatment of distal femoral type C fractures by comparing with Swashbuckler approach. A retrospective analysis was made on 43 patients with distal femoral type C fractures between January 2014 and June 2018. Twenty-two patients were treated with open reduction via mini-Swashbuckler approach and internal fixation with less invasive stabilization system (LISS) plate in modified group; and 21 patients were treated with open reduction via Swashbuckler approach and internal fixation with LISS plate in traditional group. There was no significant difference in age, gender, cause of trauma, fracture classification, fracture side, interval between injury and operation, and complications between the two groups ( P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy times, hospitalization time, fracture healing time, Hospital for Special Surgery (HSS) scores of the knee, and postoperative complications were recorded and compared between the two groups. The operation successfully completed in both groups. The operation time of the modified group was significantly longer than that of the traditional group, the fluoroscopy times was increased and the blood loss was reduced, the differences were significant ( P<0.05). There was no significant difference in hospitalization time between the two groups ( t=0.277, P=0.783). All patients in the two groups were followed up 6-8 months, with an average of 7.2 months. Fractures healed in both groups, there was no significant difference in healing time between the two groups ( t=0.861, P=0.394). The HSS scores of the modified group were 82.91±2.88 and 89.28±3.63 at 3 and 6 months after operation, respectively, which were superior to those of the traditional group (74.62±3.64) and (81.48±4.55) ( t=8.306, P=0.000; t=6.231, P=0.000). There was 1 case of incision infection, 1 case of deep vein thrombosis, and 2 cases of knee flexion and extension dysfunction in traditional group, and 1 case of deep vein thrombosis, 1 case of varus deformity, and 1 case of internal fixation loosening in modified group. There was no significant difference in the incidences of complications between the two groups ( P>0.05). Compared with Swashbuckler approach, mini-Swashbuckler approach has limited visual field exposure, which leads to prolonged operation time and increased fluoroscopy times, but the risks of complications do not increase. Because of its small soft tissue injury and less blood loss, it is conducive to the recovery of knee joint function after operation.

Fractures of femoral medial condyle treated with contralateral less invasive stabilization system through a medial-posterior approach

Objective To investigate the therapeutic efficacy of contralateral less invasive stabilization system (LISS) through a medial-posterior approach for fractures of femoral medial condyle. Methods From December 2010 to December 2014, 14 patients with fracture of femoral medial condyle were treated surgically at our department. They were 10 males and 4 females, aged from 33 to 64 years (average, 44.6 years). By AO classification, 10 cases were type 33-B2 and 4 cases type 33-B3. Causes of injury included traffic accident in 7 cases, falling in 6 and heavy object crush in one. Internals from injury to operation ranged from 3 to 10 days (average, 5.4 days). All the patients were treated by open reduction and internal fixation with contralateral LISS plate or T plate through a knee medial posterior approach. Results The 14 patients were followed up for 12 to 24 months (average, 18 months). All fractures got bony healing after 3 to 5 months (average, 3.5 months). No collapse of joint surface, joint stiffness, joint infection, malunion or nonunion occurred. According to the Schatzker-Lambert criteria for functional recovery of the distal femoral fractures, the function of the affected knee was assessed at the last follow-up as excellent in 9 cases, good in 3, fair in one and poor in one. Conclusion Open reduction and internal fixation with contralateral LISS plate through a medial-posterior approach is effective for fractures of femoral medial condyle due to its strong buttress, rigid fixation, advantage for early functional exercise, and satisfactory therapeutic outcome. Key words: Femoral fractures; Fracture fixation, internal; Bone plates; Posterior median approach

Surgical technique for biological fixation of closed segmental tibial fractures by the Less Invasive Stabilization System (LISS).

Introduction: This prospective case series study aimed to assess the value of the Less Invasive Stabilization System (LISS) to treat closed Segmental Tibial Fractures (STFs) using a proposed surgical technique.Materials and methods: Between August 2010 and January 2014, 21 consecutive recently (within 1 week) closed STFs that matched the inclusion criteria were enrolled. Patients were treated with the 13-hole LISS plate. All patients were followed up every 2 weeks for the first 2 months, then every month for the rest of the first 6 months and then every 6 months thereafter. Patients were assessed radiologically during the follow-up appointments and clinically at the final visit by the Lower Extremity Functional Scale (LEFS) to evaluate the result.Results: The mean time to union of the proximal fracture was 15.72 ± 2.78 (range: 12–20) weeks and for the distal fracture was 20 ± 2.22 (range: 16–24) weeks, excluding delayed union in three patients. All patients except the three showed radiological observable callus in a mean duration of 4.95 (range: 3–7) weeks. The mean final follow-up LEFS was 72.4 (range: 60–80).Conclusion: The mean time to union of the proximal fracture was shorter than the distal fracture. The use of LISS to treat closed STFs using the proposed surgical technique has proved to give favorable results. Further studies using the described technique are needed to justify the achieved results.Level of evidence: IV (Prospective case series).

An advanced simulator for orthopedic surgical training.

The purpose of creating the virtual reality (VR) simulator is to facilitate and supplement the training opportunities provided to orthopedic residents. The use of VR simulators has increased rapidly in the field of medical surgery for training purposes. This paper discusses the creation of the virtual surgical environment (VSE) for training residents in an orthopedic surgical process called less invasive stabilization system (LISS) surgery which is used to address fractures of the femur. The overall methodology included first obtaining an understanding of the LISS plating process through interactions with expert orthopedic surgeons and developing the information centric models. The information centric models provided a structured basis to design and build the simulator. Subsequently, the haptic-based simulator was built. Finally, the learning assessments were conducted in a medical school. The results from the learning assessments confirm the effectiveness of the VSE for teaching medical residents and students. The scope of the assessment was to ensure (1) the correctness and (2) the usefulness of the VSE. Out of 37 residents/students who participated in the test, 32 showed improvements in their understanding of the LISS plating surgical process. A majority of participants were satisfied with the use of teaching Avatars and haptic technology. A paired t test was conducted to test the statistical significance of the assessment data which showed that the data were statistically significant. This paper demonstrates the usefulness of adopting information centric modeling approach in the design and development of the simulator. The assessment results underscore the potential of using VR-based simulators in medical education especially in orthopedic surgery.

Anatomical and radiological evaluation of less invasive stabilisation system (LISS) in correlation with knee lateral collateral ligament insertion

IntroductionThe Less Invasive Stabilisation System (LISS) is an angle-stable plate that enables treatment of distal femoral comminuted and periprosthetic fracture. As it is placed through a minimally-invasive lateral approach, lateral knee pain is a commonly described symptom after its application. This study investigates knee lateral collateral ligament (LCL) iatrogenic injury during LISS plate fixation. A cadaver study was performed and a retrospective radiological investigation with the analysis of its clinical application was conducted to evaluate possible knee LCL damage. MethodsThe cadaver study included 13 human lower extremities, treated with LISS. After application, lateral knee side was dissected, implants were removed and distances between the drill holes and LCL origin were measured. In the retrospective radiological evaluation, postoperative X-rays for patients treated with distal femoral LISS plate in the University Hospital Regensburg, Germany from January 2010 to December 2015 were examined. Following a protocol described by Pietrini et al., the LCL origin on postoperative X-rays was calculated, both in lateral and anterior-posterior (AP) view, and distances between the plate and its closest locking screw to the LCL origin were measured. ResultsIn the cadaver study, the mean distance between the closest drilling hole and the ligament origin was 14.0mm (range 9–21mm; SD 3.8mm). Twenty-two patients matched the inclusion criteria for the retrospective radiological study. In lateral view, the mean distance between the origin and the closest locking screw was 6.3mm (range 0–16.4mm; SD 4.7mm); the mean distance between the origin and the plate was 3.1mm (range 0–13.9mm; SD 4.1mm). In AP view, the mean distance between LCL origin and the nearest screw was 2.4mm (range 0–7.6mm; SD 2.4mm). The mean distance between the origin and the most distal locking screw was 9.2mm (range 0–17.5mm; SD 4.0mm). DiscussionThe LISS is a safe option to treat distal femoral fractures in respect to the LCL. Due to close proximity, the LCL might be harmed; therefore, lateral knee pain or lateral instability after implantation should be assessed in further treatment.

Inversive LISS plate in treating intertrochanteric and subtrochanteric fractures combined with femoral shaft fractures

To study clinical effects of inversive LISS(less invasive stabilization system, LISS) plate for the treatment of intertrochanteric and subtrochanteric fractures combined with femoral shaft fractures. From January 2012 to January 2015, 24 patients with intertrochanteric and subtrochanteric fractures combined with femoral shaft fractures were treated with inversive LISS plate, included 16 males and 8 females with an average age of 62.5 years old ranged from 35 to 81 years old. There were 8 cases of traffic accident injuries, 3 cases of falling from high place, and 13 cases of falls injuries. The time from injury to operation was ranged from 2 to 12 days with an average of 5.2 days. The operation time, intraoperative blood loss and the length of hospitalization were analyzed. The fracture union was assessed by follow-up radiographs and hip functional recovery by Harris hip scoring. All patients were followed up for 16.2 months (ranged, 18 to 36 months). The mean operative time was (68.22±48.36) min;the mean blood loss was (256.28±182.46) ml;the mean time of hospitalization was(14.8±5.2) days. There were no complications such as deep infection, deep vein thrombosis, pulmonary embolism and bone nonunion during the follow up period. The bone healing was ranged from 3 to 8 months with an average of 4.8 months. The mean Harris score was 76.49±12.28 at the final follow-up, 15 cases were classified as excellent, 6 as good and 3 as fair. Inversive LISS plate can be used in treating with intertrochanteric and subtrochanteric fractures combined with femoral shaft fractures, and should not emphasis on premature loading.

Free Vascularized Fibular Graft With LISS Plate for the Bone Defects of the Femur After Tumor Resection

Background: Various methods for reconstructing large femur bone defects after tumor resection have been introduced. In this study, we reviewed the clinical outcomes of using a one-barrel free vascularized fibular graft (FVFG) protected by a less invasive stabilization system (LISS) plate for lesions not involving the joint. Methods: Between August 2007 and August 2013, we treated 7 patients with large femoral bone defects after tumor resection. The mean age of the patients was 19 years (range, 12-36 years), and 3 were women. All were diagnosed preoperatively with osteosarcoma. Femoral bone defects were reconstructed using an in-lay strut FVFG following a LISS femoral plate. The mean bone defect size was 10.5 cm (range, 6-16 cm). We reviewed clinical outcomes at the last follow-up. Result: All patients survived beyond the last follow-up; the mean follow-up period was 54 months (range, 26-100 months). Two patients (28.5%) sustained stress fractures of the FVFG, but the LISS plate protected the fractured graft until in situ bone healing occurred. One case of metal failure of the LISS plate was encountered; the plate was replaced with a longer one, which achieved bone union. Mean time to bone union of both host-graft junctions was 24 months (range, 18-31 months). The mean Musculoskeletal Tumor Society score (%) was 85.8% (range, 80-95%). Conclusion: A one-barrel FVFG protected by a LISS plate maintained a stable graft-host bone construct, successfully leading to bone union, even in cases of stress fractures of the graft, and appears to be a good option for large femur bone defects after tumor resection.

Complication of the less invasive stabilization system for mechanically unstable fractures of the distal femur

Objective To investigate the results and complications in the treatment of the mechanically unstable fractures of the distal femur when Less Invasive Stabilization System (LISS) is used. Methods From September 2011 to July 2014, 81 patients with mechanically unstable fractures of the distal femur were treated with the LISS, according to the inclusion criteria and exclusion criteria, 59 patients meet the condition including 31 male and 28 female. The mean age of the patients was 49.8 years (range 18-80 years). The fractures occurred on the left side in 40 cases and on the right side in 19 cases. According to AO classification, 27 type 33A2, 14 type 33A3, 13 type 33C2, 5 type 33C3. 2 cases combined with ipsilateral fractures of the femoral shaft, according to AO classification, 1 type 32A1, 1 type 32C1. The mechanism of injury was a fall from the height in 8 cases, a traffic accident in 18 cases, a crush injury in 7 cases, a fall injury in 26 cases. 55 fractures were closed, and 4 were open. According to the Gustilo-Anderson classification, there were 3 type Ⅰ, 1 type Ⅱ. Results The 7-hole plate were used in 21 patients, 9-hole plate in 26 patients and 13-hole plate in 12 cases . The 3.5 mm or 6.5 mm lag screw were placed around the LISS plate to stabilized the articular fracture fragment in 11 cases. The mean operation time was 105.2 min (85-145 min), the mean bleeding volume was 203 ml (130-315 ml). All patients were followed up 11-27 months (average 13.2 months). 1 delayed union(13 months), the average time to union was 16 weeks (range 12-21 weeks). The average flexion of the knee was 116 degree, 0 degree in extension. The functional outcome: 32 had an excellent result, 19 had a good result and 8 had a fair result, with 86.4% excellent and good results. No deep infections occurred. No loss of reduction. 3 cases had malalignment, 2 failed fixation, 4 patients with symptomatic hardware irritation. 27 cases underwent implants removal after union, cold-welding occurred in 4 cases (9 screws) which resulted in difficult removal. Conclusion LISS is one of the reliable and effective methods in fixation of mechanically unstable fractures of the distal femur. However, its operation indications and operating instructions should be strictly followed. Key words: Internal fixators; Femoral fractures; Surgical procedures, Minimally invasive

Combination of modified free vascularized fibular grafting and reverse Less Invasive Stabilization System (LISS) for the management of femoral neck nonunion in patients thirty years of age or younger

Femoral neck nonunion (FNN) is a potential complication in patients with displaced femoral neck fractures, occurring in 33%. This may lead to early hip dysfunction or arthroplasty. Combination of modified free vascularized fibular grafting (FVFG) and a reverse LISS may provide a reasonable means to salvage a painless, functional and native hip.Between August 2010 and August 2012, sixteen patients with femoral neck nonunion were treated with a combined procedure involving modified free vascularized fibular grafting and a reverse LISS. The average age of them is 20.3 years (range 12.0–28.0 years). After removing old implants, the nonunion site was debrided, reduced and fixed with a LISS. The fibular grafts were compacted into a trough in the femoral neck. The Harris Hip score system was used to assess hip function and anteroposterior and frog-lateral hip roentgenograms were used to evaluate bone healing.All femoral neck nonunion healed without severe complications. The mean follow-up time was 32.9 months (range 23.0–47.0 months) and the average union time was 7.6 months (range 5.0–10.0 months). All coxa vara deformities and retroversions of the femoral head were corrected. The Harris hip scores (HHS) were improved 36.6 points on average (59.6 points preoperatively to 96.2 points postoperatively). No incidences of osteonecrosis of the femoral head were observed.The combined modified FVFG and reverse LISS plating is a suitable procedure for the management of femoral neck nonunion in patients younger than 30 years, especially for those patients with a revision history.

External fixation using femoral less invasive stabilization system plate in tibial proximal metaphyseal fracture.

BackgroundThe locking plates are often used for internal fixation of closed tibial fractures. The use of a locking plate as an external fixator is still controversial, particularly for closed fractures. The purpose of this study is to evaluate the results of external fixation using the femoral less invasive stabilization system (LISS) plate in proximal metaphyseal fractures of the tibia.MethodsWe prospectively evaluated 35 patients (26 males and 9 females) with a mean age of 42 years (range, 21 to 62 years) who presented with fresh tibial proximal metaphyseal fractures. According to the AO Foundation and Orthopaedic Trauma Association (AO/OTA) classification, the fractures were identified as type 41-A2 in 18 cases and type 41-A3 in 17 cases, including 25 closed fractures and 10 open fractures. The femoral LISS plate was used to fix these fractures, which was placed on the anteromedial aspect of the tibia as an external fixator. The mean follow-up period was 18 months (range, 13 to 22 months).ResultsAll fractures healed in a mean time of 14 weeks (range, 10 to 20 weeks). There was no case of nonunion, deep infection, and loosening of screws and plates. One month after the appearance of cortical bridging on biplanar radiographs, the locking plate was removed within 3 minutes in the clinic without any difficulty. According to the Hospital for Special Surgery (HSS) knee scoring system and American Orthopaedic Foot & Ankle Society (AOFAS) ankle scoring system, the mean HSS score was 91 (range, 85 to 100) and 98 (range, 93 to 100), and the mean AOFAS score was 94 (range, 90 to 100) and 98 (range, 95 to 100) at 4 weeks postoperatively and final follow-up, respectively.ConclusionsFor proximal metaphyseal fracture of the tibia, external fixation using the femoral LISS plate is a safe and reliable technique with minimal complications and excellent outcomes. Its advantages include ease of performing the surgery, use of a less invasive technique, and convenience of plate removal after fracture healing.

Reverse less invasive stabilization system for treatment of femoral intertrochanteric fracture

Objective To evaluate the clinic effect of reverse less invasive stabilization system (LISS) in treatment of femoral intertrochanteric fracture.Methods The study enrolled 22 cases of femoral intertrochanteric fractures treated with reverse LISS from January 2007 to January 2011.Twelve out of the cases were males and 10 were females,with age ranging from 44 to 86 years (mean,72.5 years).Left fracture occurred in 8 cases and right in 14 cases.Causes of injury included fall on the ground in 15 cases,vehicle accidents in 4 cases,and fall from height in 3 cases.There were 15 cases of type Ⅲ and 9 of type Ⅳ according to Evans-Jensen classification and all fractures were closed injuries.Time from injury to operation was 3-14 days (mean,5.3 days).Results Intraoperative hemorrhage was (130.5 ± 60) ml and operation time was (55 ± 15) min.All cases were followed up for 12-30 months (mean,14.8 months).Fracture healing time was 10-27 weeks (mean,13.4 weeks).Harris hip score was excellent in 11 cases,good in 8,fair in 2,and poor in 1,with excellent and good rate of 86％.Two cases felt greater trochanter pain at follow-up ; one presented with plate breakage and malunion at 6 months postoperatively,but may need no further treatment; the rest healed without complications of surgical site infection,varus deformity of the hip,implant breakage,fracture redisplacement,screw drawing pullout or cutout.Conclusion Reverse LISS plating is an effective treatment for femoral intertrochanteric fractures,but the procedure can not assure 100％ success. Key words: Femoral fractures; Fracture fixation,internal; Surgical procedures, minimally invasive

Management of the Schatzker VI fractures with lateral locked screw plating

Complex proximal tibial plateau fractures need surgical treatment to achieve good clinical results. The treatment of this kind of fractures is often complicated either by the patient's compromised general conditions, or by soft tissue damage. The locking plate combines the technical advantages of an angular stable plate with those of the modern biological plating technique. From December 2002 to December 2008 we treated 18 patients with complex fractures of the tibial plateau (Schatzker VI). All patients were treated with a fixed angle locking plate, 15 with the LISS (Less Invasive Stabilisation System) and 3 with ZPLT (Zimmer Periarticular Locking Plate system). Average time for full weight bearing was 16.2 weeks. In 3 cases we removed the fixation devices after healing because the patients didn't tolerate the fixation devices. Two patients developed superficial infections that we treated with antibiotic therapy. In 2 cases the LISS plate broke because of pseudarthrosis at the diaphyseal level. To conclude, analysing the results we obtained, we consider that the LISS system is an extremely effective fixation device for the treatment of such difficult and complicated fractures as high energy tibial plateau fractures certainly are. Indirect reduction of the fracture, obtained either with an external fixator, or with traction, must precede the use of the fixation device. The failures, such as post-op malalignment or loss of reduction, are due to a wrong evaluation of the fracture morphology. In fact, comminuted fractures, dislocation and rotation of the medial tibial plateau cannot be stabilised just with lateral angular stable plates, but fixation of the medial tibial plateau must be performed first.

Salvage procedures for trochanteric femoral fractures after internal fixation failure: Biomechanical comparison of a plate fixator and the dynamic condylar screw

The aim of this study was the biomechanical evaluation of the reversed less invasive stabilization system (LISS) internal fixation as a joint-preserving salvage procedure for trochanteric fractures. Five LISS plates and five dynamic condylar screws (DCS) were tested using synthetic femora (Sawbones) with an osteotomy model similar to a type-A2.3 pertrochanteric fracture. The constructs were subjected to axial loading up to 1000 N for five cycles. Then, the force was continuously increased until fixation failure. For the evaluation of the biomechanical behaviour, the stiffness levels were recorded and the osteotomy gap displacement was mapped three-dimensionally. The average stiffness for the constructs with LISS plates was 412 N/mm (with a standard deviation (SD) of 103N/mm) and 572N/mm (SD of 116 N/mm) for the DCS constructs (p=0.051). Local displacement at the osteotomy gap did not yield any significant differences. The LISS constructs failed at a mean axial compression of 2103N (SD of 519N) and the DCS constructs at a mean of 2572N (SD of 372N) (p=0.14). It is concluded that the LISS plate offers a reliable fixation alternative for salvage procedures.

Reverse LISS plating for intertrochanteric Hip Fractures in elderly patients

BackgroundFractures of the intertrochanteric hip are common and the treatment of unstable fractures generally requires an operative approach. In elderly patients, osteoporosis makes internal fixation problematic and frequently contributes to failed fixation and poor clinical results. We have attempted to apply the Less Invasive Stabilization System (LISS) in reverse position for the repair of intertrochanteric hip fractures in elderly patients with osteoporotic bones. A retrospective review is presented of the cases of 28 elderly patients with stable and unstable fractures of the intertrochanteric hip treated using the reverse LISS.MethodsWe treated 28 elderly patients with a mean age of 82.3 years. According to the Evens classification, there were 2 Type I fractures, 2 Type II fractures, 3 Type III fractures, 13 Type IV fractures, 6 Type V fractures and 2 Type R fractures. All fractures were treated using the reverse LISS. Radiographic and clinical evidence of functional outcome and complications were evaluated.ResultsMean perioperative blood loss was 92.4 milliliters (range 35 to 245 milliliters), and the mean postoperative hospital stay was 8.7 days (range 3 to 14 days).Complications included one minor wound hematoma. Radiographically, no collapses, screw cutouts, or head penetrations were seen. All surviving patients (28 of 28; 100 percent) had uneventful fracture healing with union achieved by six months in all patients.ConclusionsUse of the Reverse LISS plating for intertrochanteric hip fractures resulted in event-free fracture healing.

Technical Problems and Complications in the Removal of the Less Invasive Stabilization System

This study was designed to evaluate the frequency of intraoperative problems and complications involved with Less Invasive Stabilization System (LISS) plate removal. Retrospective study. Single academic level I trauma center. Medical records were reviewed for demographics, surgical technique, plate length, number and position of screws, time from internal fixation to plate removal, reason for removal, operating time for removal, and perioperative complications. Pre- and post-op radiographs were also reviewed to confirm plate and screw positions. The independent factors including age, sex, plate site, plate screws placed/available holes, union status, and time from internal fixation to removal were compared between patients in whom screw removal was complicated to those in whom screw removal proceeded without difficulty. Mann-Whitney and Fisher Exact tests were calculated with the level of significance at P < 0.05. There were 33 patients (24 men and 9 women) that underwent LISS plate removal from 36 extremities (15 tibias and 21 femurs). The average time from internal fixation to removal was 13.2 months. The plates removed were 13-hole plates (16 cases), 9-hole plates (18 cases), and 5-hole plates (2 cases), which included a total of 349 screws. The specific reasons for plate removal were symptomatic implants after bone union (21 cases), nonunion requiring additional fixation (12 cases), early loss of fixation (2 cases), and a peri-implant fracture after bone union (1 case). The average operating time for plate removal was 71.3 minutes (range, 28-180 minutes). Five cases required more than 120 minutes. Difficulty with screw removal was encountered in 37 screws (10.6%) from 14 cases (38.9%). Two plates and 11 screw heads required cutting using a carbide or diamond tipped burr. Six cases required tearing the plate off bone by levering with a total of 10 screws still attached. Five screws were cut using a large bolt cutter. The other screws were stripped and removed with a stripped screw removal tap. Two patients developed a postoperative superficial wound infection that required treatment with oral antibiotics. One patient had a postoperative peroneal nerve palsy that recovered spontaneously. There were no statistical differences in predictors for patients with screw removal difficulty. Difficulty with removal due to cold welding or screw head stripping is common in locking LISS plate screws. LISS plate removal can often require prolonged operating time and the use of specialized removal tools. Surgeons should anticipate the possibility of difficulties when removing these implants and be appropriately prepared.

Reverse LISS plates for unstable proximal femoral fractures

The best treatment for unstable proximal femoral fractures is controversial. In this prospective study, we assessed the outcomes of reverse less invasive stabilisation system (LISS) plates for treatment of unstable proximal femoral fractures that are expected to be difficult to nail. From April 2004 to January 2007, 20 patients with unstable proximal femoral fractures that were assessed to be difficult to nail were managed with reverse less invasive stabilisation system–distal femur (LISS–DF) plates, which included (1) subtrochanteric fractures with extension into the piriform fossa, (2) short skeletons with narrow femoral canals, (3) adolescents with open physes and (4) severely bowed or deformed femurs. These patients were enrolled in this study. There were 11 females and nine males, with a median age of 58 years (range, 14–95 years). The average follow-up period was 24 (range, 12–32) months. Functional recovery (Parker and Palmer mobility score), pain, bony union, varus deformity, implant failure and leg length discrepancy were assessed. The fractures united at a median of 7 months (range, 3–15 months) postoperatively. Parker and Palmer mobility scores were 9 points for 17 patients and 6 points for three patients. Pain was absent in 15, mild in three, and moderate in two patients. Patients with poor quality of reduction were more likely to have pain results ( p = 0.009). Although patients with advanced age were not more likely to have pain results, they were more likely to have ‘delayed union’ radiographic results ( p = 0.033). Two limbs were shortened by 1.5 and 2 cm, respectively. Reverse LISS plate fixation led to complete union of unstable proximal femoral fractures without additional procedures. The surgical technique was simple and safe. We recommend considering the use of this locked-plate device as the alternative management of unstable proximal femoral fractures that are unsuitable for nailing procedures.