Less Invasive Stabilization System Group Research Articles

Less invasive stabilization system versus open reduction and internal fixation of closed proximal tibial fractures in adults

Objective The aim of this study was to compare the clinical and radiological outcome between less invasive stabilization system (LISS) and open reduction with internal fixation (ORIF) for the treatment of extra-articular 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. However, it is 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 two groups. Group I (n = 15) patients were treated with LISS and group II (n = 15) with 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 showed union, two patients showed nonunion, and one patient showed delayed union. The mean operative time in LISS patients was 79.3 min, whereas in ORIF patients it was 122 min. All patients of the LISS group were exposed to radiation, whereas only 40% of patients in the ORIF group were exposed to radiation. The mean time of union in LISS patients was 10.87 weeks. However, in ORIF patients, the mean time of union was 21.13 weeks. There was no significant difference between the two groups as regards the postoperative complications. Functional outcome was satisfactory in both groups. Conclusion LISS achieves comparable results with ORIF in extra-articular 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.

Augmentative locking plate with autologous bone grafting for distal femoral nonunion subsequent to failed retrograde intramedullary nailing

ObjectiveTo explore the indications and efficacy of augmentative locking compression plate (LCP) or less invasive stabilization system (LISS)with autogenous bone grafting (BG) in treating distal femoral nonunion subsequent to failed retrograde intramedullary nailing (RIN). MethodsA retrospective study was performed for 21 patients with distal femoral nonunion subsequent to failed RIN, who received therapy with either augmentative LCP (n = 11) or LISS with autogenous BG (n = 13). Operation time, time to union, union rate, time to renonunion, complication rate and SF-36 scores a year after hardware removal were compared between the two groups. ResultsThe bone union occurred in 13/13 (100%) cases in augmentative LISS group versus 9/11 (81.8%) cases in augmentative LCP group [odds ratio (OR) = 3.21, 95% confidence interval (CI) 0.7–13]. Time to union, time to renonunion, complication rate of the augmentative LCP group were significantly more than that of the augmentative LISS with autogenous BG group (p = 0.023, p = 0.021 and p = 0.033). No significant difference was found in the average operation time of two groups (p = 0.121). At the follow-up a year after hardware removal, statistically significant HRQOL improvement in the augmentive LISS group was measured at the level of pain (p = 0.003) and general health perception (p = 0.011), as compared to the augmentive LCP group. ConclusionsWe suggest augmentative LCP, for distal femoral nonunios after RIN, may be optimal for that of typeAO33A fractures, whereas augmentative LISS for that of typeAO33C fractures more.

Less Invasive Stabilization System (LISS) Versus Proximal Femoral Nail Anti-rotation (PFNA) in Treating Proximal Femoral Fractures

To evaluate the outcome and efficacy of LISS (Less Invasive Stabilization System; Synthes USA, Paoli, PA) for the treatment of proximal femoral fractures to find another appropriate minimally invasive surgery for these fractures in which intramedullary nailing may be difficult. A consecutive prospective randomized clinical study. University teaching hospital. Between May 2006 and March 2008, 64 consecutive patients who had a proximal femoral fracture were randomized to be treated with fixation with either LISS or PFNA (Proximal Femoral Nail Anti-rotation; Synthes USA). LISS or PFNA fixation of proximal femoral fractures. Intraoperative time, intraoperative blood loss, length of hospitalization, hip function (Harris score), general complications, fracture complications. Fifty-nine patients were evaluated with a mean follow-up time of 26.8 months (range, 21-36 months). No statistical differences in general complications, intraoperative blood loss, length of hospitalization, or hip function could be found between the two groups. The average operative time was longer in the LISS group (98.25 minutes) compared with the PFNA group (65.36 minutes) (P < 0.05). One PFNA case had intrapelvic penetration of the helical blade; two LISS cases had breakage of the screws. There were no major differences in outcome or complications between the treatment groups. LISS can be used effectively in treating proximal femoral fractures, especially for complex fractures patterns in which intramedullary nailing may be difficult. Therapeutic Level II. See page 128 for a complete description of levels of evidence.

Treatment of Distal Femoral Fracture by Minimally Invasive Percutaneous Plate Osteosynthesis: Comparison Between the Dynamic Condylar Screw and the Less Invasive Stabilization System

Treatment of distal femoral fractures by percutaneous plating without direct manipulation of the fracture fragments leads to good clinical outcome. Percutaneous plating has traditionally involved using a dynamic condylar screw (DCS) and the less invasive stabilization system (LISS) was reported. The biomechanical study showed that the LISS had the enhanced ability to withstand higher loads. However, there were no clinical comparison study of distal femoral fractures treated with DCS and LISS. The aim of this study was to outline any differences in clinical and radiological results between the DCS and the LISS for treating distal femoral fractures. Forty-five supracondylar or intercondylar femoral fractures were treated by minimally invasive percutaneous plating with the DCS or the LISS without bone graft. There were 26 patients with 26 fractures in the DCS group and 19 patients with 19 fractures in the LISS group. The data of the clinical and radiographic outcomes were compared between the two different fixation devices. Complete union was achieved in 41 of the 45 patients (91.1%). The success rate was 96.2% in the DCS group and 94.7% in the LISS group (p = 0.672). The mean fusion time was 19.18 weeks in the DCS group and 19.38 weeks in the LISS group (p = 0.835). The average range of motion of the knee joint was 111.65 degrees in the DCS group and 116.26 degrees in the LISS group (p = 0.334). Early implant failure only occurred in the DCS group (11.5%, p = 0.252, odds ratio = 1.826 [95% CI: 1.387-2.404]). The total complication rate was 15.4% in the DCS group and 15.8% in the LISS group (p = 0.641). The mean loss of coronal fracture fragment angle was -0.77 degrees in the DCS group and -0.19 degrees in the LISS group (p = 0.125). Minimally invasive percutaneous plating with the DCS or the LISS provides good outcome with few complications in the treatment of distal femoral fractures. Both systems minimize soft tissue trauma. LISS seems to have lower risk of early implant loosening than the DCS.

A comparative study of Less Invasive Stabilization System (LISS) fixation and two-incision double plating for the treatment of bicondylar tibial plateau fractures

The present investigation is a prospective study comparing the use of locked plates and classic double plates for the repair of bicondylar tibial plateau fractures. Eighty-four patients with bicondylar tibial plateau fractures were treated with plate fixation by either a locked plate (Less Invasive Stabilization System, LISS) or classic double plates (DP). All patients were followed for a minimum of 24 months. Outcomes were assessed by recording the surgical experience with each approach, post-operative complications and improvements in knee function as measured by the Hospital for Special Surgery (HSS) score. For all patients, no differences in the mechanisms of injury, fracture type, open fracture grade, mean age, gender distribution, associated medical conditions, pre-surgical stay, surgical time, bony union rate or radiographic healing times were observed between the two groups. Also, the HSS score and incidences of infection, seroma, hematoma, deep venous thrombosis, loss of reduction, loss of alignment, hardware failure and overall post-operative complications were all similar in both groups (P>0.05). Wound size and blood loss were significantly less in the LISS group than in the DP group (both P<0.05). A significantly higher incidence of post-operative malalignment of the proximal tibia (P=0.041) and a trend toward significance of a higher incidence of symptomatic hardware irritation (P=0.057) were observed in the LISS group compared to the DP group. In conclusion, LISS provides an alternative treatment for bicondylar tibial plateau fractures, but it may not replace the conventional two-incision double plating technique as the standard of care.

Intramedullary Stabilization of Extraarticular Proximal Tibial Fractures: A Biomechanical Comparison of Intramedullary and Extramedullary Implants Including a New Proximal Tibia Nail (PTN)

To determine in the laboratory whether there are or are not differences between individual geometrical designs of intramedullary and extramedullary devices used for the fixation of extraarticular proximal tibial fractures. Five devices were tested: a newly developed Proximal Tibia Nail (PTN), conventional double-plate osteosynthesis (DPO), the Less Invasive Stabilization System (LISS), an augmented Unreamed Tibial Nail with a T-stabilization-plate (UTN + TSP), and an external fixator (ExFix). A 10-mm defect osteotomy was performed on paired human tibiae, and the proximal and distal ends were potted in polymethylmethacrylate cement (PMMA). Each pair of bones was randomly stabilized with the new PTN in 1 tibia (Groups PTN1 through PTN4) and in 1 of the 4 comparative implants in the corresponding contralateral bone. A biomechanical test of the bone implant construct was then performed with a vertical axial force of 350, 600, and 900 N, a bending moment of 6 Nm and a bidirectional rotational strain of 8 Nm. Displacement of bone fragments was measured and depicted as a force-displacement diagram. For axial loading, significant differences were seen between the PTN 2 group compared to the LISS group (P = 0.016) and the PTN 4 group compared to the ExFix group (P = 0.016). No statistically significant differences were seen for the PTN 1 group compared to the DPO group (P = 0.125) and the PTN 3 group compared to the UTN + TSP group (P = 0.453). The bending stiffness of the PTN 1-4 groups was not significantly different from any of the 4 alternative implants. There was comparable torsional stiffness in all implant groups except for the UTN + TSP group, which was less stable and significantly different from the PTN 3 group (P = 0.016). Given the parameters of this investigation, the new PTN would theoretically provide the same mechanical stability as the DPO in axial loading. Higher stability in axial loading may be present when compared to the LISS or the ExFix. Further clinical investigation of this implant will determine its usefulness among proximal tibial fixation devices.