Philip J. Kregor

Treatment of distal femur fractures using the less invasive stabilization system: surgical experience and early clinical results in 103 fractures.

Objective: To summarize the complications and early clinical results of 123 distal femur fractures treated with the Less Invasive Stabilization System (LISS; Synthes, Paoli, PA). Design: Retrospective analysis of prospectively enrolled patients. Setting: Two academic level I trauma centers. Subjects and Participants: One hundred nineteen consecutive patients with 123 distal femur fractures (OTA type 33 and distal type 32 fractures) treated by 3 surgeons. One hundred three fractures (68 closed fractures and 35 open fractures) in 99 patients were followed up at least until union (mean follow-up = 14 months, range: 3–50 months). Intervention: Surgical reduction and fixation of distal femur fractures. Main Outcome Measurements: Perioperative complications, radiographic union, infection rate, loss of fixation, alignment, and range of motion. Results: Ninety-six (93%) of 103 fractures healed without bone grafting. All fractures eventually healed with secondary procedures, including bone grafting (1 of 68 closed fractures and 6 of 35 open fractures). There were 5 losses of proximal fixation, 2 nonunions, and 3 acute infections. No cases of varus collapse or screw loosening in the distal femoral fragment were observed. Malreductions of the femoral fracture were seen in 6 fractures (6%). The mean range of knee motion was 1° to 109°. Conclusions: Treatment of distal femur fractures with the LISS is associated with high union rates without autogenous bone grafting (93%), a low incidence of infection (3%), and maintenance of distal femoral fixation (100%). No loss of fixation in the distal femoral condyles was observed despite the treatment of 30 patients older than 65 years. The LISS is an acceptable surgical option for treatment of distal femoral fractures.

Recombinant human bone morphogenetic protein-2 in open tibial fractures. A subgroup analysis of data combined from two prospective randomized studies.

BACKGROUND The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) to improve the healing of open tibial shaft fractures has been the focus of two prospective clinical studies. The objective of the current study was to perform a subgroup analysis of the combined data from these studies. METHODS Two prospective, randomized clinical studies were conducted. A total of 510 patients with open tibial fractures were randomized to receive the control treatment (intramedullary nail fixation and routine soft-tissue management) or the control treatment and an absorbable collagen sponge impregnated with one of two concentrations of rhBMP-2. The rhBMP-2 implant was placed over the fracture at the time of definitive wound closure. For the purpose of this analysis, only the control treatment and the Food and Drug Administration-approved concentration of rhBMP-2 (1.50 mg/mL) were compared. Patients who anticipated receiving planned bone-grafting as part of a staged treatment were excluded from enrollment. RESULTS Fifty-nine trauma centers in twelve countries participated, and patients were followed for twelve months postoperatively. Two subgroups were analyzed: (1) the 131 patients with a Gustilo-Anderson type-IIIA or IIIB open tibial fracture and (2) the 113 patients treated with reamed intramedullary nailing. The first subgroup demonstrated significant improvements in the rhBMP-2 group, with fewer bone-grafting procedures (p = 0.0005), fewer patients requiring invasive secondary interventions (p = 0.0065), and a lower rate of infection (p = 0.0234), compared with the control group. The second subgroup analysis of fractures treated with reamed intramedullary nailing demonstrated no significant difference between the control and the rhBMP-2 groups. CONCLUSIONS The addition of rhBMP-2 to the treatment of type-III open tibial fractures can significantly reduce the frequency of bone-grafting procedures and other secondary interventions. This analysis establishes the clinical efficacy of rhBMP-2 combined with an absorbable collagen sponge implant for the treatment of these severe fractures.

Biomechanical evaluation of the less invasive stabilization system, angled blade plate, and retrograde intramedullary nail for the internal fixation of distal femur fractures.

Objective: To evaluate the stability of the retrograde intramedullary nail (IMN), angled blade plate (ABP), and a locked internal fixator (Less Invasive Stabilization System [LISS], Synthes, Paoli, PA) for internal fixation of distal femur fractures. Design: Destructive biomechanical testing of matched pairs of fresh–frozen human cadaveric bone–implant constructs. Setting: Biomechanical laboratory. Methods: A fracture model was created to simulate an AO/OTA33-A3 fracture. Forty-eight matched pairs of specimens were used. Six groups of 8 pairs each were tested to failure: LISS versus ABP and LISS versus IMN (axial, torsional, and cyclical axial). Main Outcome Measurement: Load to failure, mode of failure, energy to failure, displacement at the load to failure, and stiffness. Results: Fixation strength (load/moment to failure) of the LISS constructs was 34% greater in axial loading (P = 0.01) and 32% less in torsional loading (P = 0.05) compared with ABP constructs and 13% greater in axial loading (P = 0.35) and 45% less in torsional loading (P < 0.01) compared with IMN constructs. Loss of distal fixation in axial loading occurred in 1 of 16 cases with the LISS, in 3 of 8 cases with the ABP, and in 8 of 8 cases with the IMN. Cyclical axial loading demonstrated significantly less plastic deformation for the LISS construct compared with ABP constructs (P < 0.01) and similar plastic deformation compared with IMN constructs (P = 0.98). Conclusions: All 3 fixation devices (LISS, ABP, and IMN) offer sufficient torsional stability and sufficient proximal fixation that withstands axial loading without failing. The LISS provides improved distal fixation, especially in osteoporotic bone, at the expense of more displacement at the fracture site.

Fixation of distal femoral fractures above total knee arthroplasty utilizing the less invasive stabilization system (L. I. S. S. )

Supracondylar femoral fractures above total knee arthroplasty remain a treatment challenge. Complication rates as high as 30% are associated with both nonoperative and operative treatment. Conventional plate fixation and rigid intramedullary nail fixation has improved the treatment of these fractures. However, problems still exist in the setting of a short distal femoral block and/or significant osteoporosis. Less Invasive Stabilization System (L.I.S.S.) fixation has been utilized for the treatment of supracondylar femoral fractures above total knee arthroplasty. Multiple fixed angle screws give optimal fixation around the femoral component. Advantages appear to include maintenance of distal femoral fixation, low infection, and low need for bone grafting.

Treatment of acute distal femur fractures above a total knee arthroplasty: Systematic review of 415 cases (1981–2006)

Background There is no consensus on the best treatment for periprosthetic supracondylar fracture. Material and methods We systematically summarized and compared results of different fixation techniques in the management of acute distal femur fractures above a total knee arthroplasty (TKA). Several databases were searched (Medline, Cochrane library, OTA and AAOS abstract databases) and baseline and outcome parameters were abstracted. Results We extracted data from 29 case series with a total of 415 fractures. The following outcomes were noted: a nonunion rate of 9%, a fixation failure rate of 4%, an infection rate of 3%, and a revision surgery rate of 13%. Retrograde nailing was associated with relative risk reduction (RRR) of 87% (p = 0.01) for developing a nonunion and 70% (p = 0.03) for requiring revision surgery compared to traditional (non-locking) plating methods. Point estimates also suggested risk reductions for locking plates, although these were not statistically significant (57% for nonunion, p = 0.2; 43% for revision surgery, p = 0.23) compared to traditional plating. RRRs for nonunion and revision surgery were also statistically significantly lower for retrograde nailing and locking plates compared to nonoperative treatment. Interpretation Modern-day treatment methods are superior to conventional treatment options in the management of distal femur fractures above TKAs. The results should be interpreted with caution, due to the lack of randomized controlled trials and the possible selection bias in case series.

Less invasive stabilization system (LISS) for fractures of the proximal tibia: Indications, Surgical Technique and Preliminary Results of the UMC Clinical Trial

The surgical treatment of proximal tibia fractures, with or without intraarticular involvement, is associated with well-described patterns of failure and significant complication rates. Recent surgical advances allow for a minimally invasive approach to such injuries, which may improve healing times, increase union rates, and decrease complication rates. The Less Invasive Stabilization System (LISS) for proximal tibia fractures employs a laterally based fixed angled implant, allowing for the placement of locking screws proximal and distal to the fracture, which may be placed percutaneously. This manuscript presents the surgical technique and indications of the Tibia LISS. A preview of the early clinical results of the treatment of bicondylar tibial plateau fractures and proximal tibia diaphysis will also be presented.

Operative treatment of acute distal femur fractures: Systematic review of 2 comparative studies and 45 case series (1989 to 2005)

Background The incidence of distal femur fractures is approximately 37 per 100,000 person-years.1 Typically, distal femur fractures are caused by a high-energy injury mechanism in young men or a low-energy mechanism in elderly women.2 Managing these fractures can be a challenging task. Most surgeons agree that distal femur fractures need to be treated operatively to achieve optimal patient outcomes. The articular fracture component is usually treated with open reduction and internal lag screw fixation or external tension wire fixation (Illizarov). However, there is no consensus on the type of implant for the fixation of the metaphyseal–diaphyseal fracture component. Objective The aim of this study is to systematically summarize and compare the results of different fixation techniques (traditional compression plating, antegrade nailing, retrograde nailing, submuscular locked internal fixation, and external fixation) in the operative management of acute nonperiprosthetic distal femur fractures (AO/OTA type 33A and C) and the characteristics of the fractures for each treatment (articular/nonarticular and open/closed). Additionally an attempt was made to evaluate the impact of surgical experience on nonunion rate, fixation failure rate, deep infection rate, and secondary surgical procedure rate. In the context of this article compression plating relates to techniques/implants that require compression of the implant to the femoral shaft—it does not relate to interfragmentary compression.

The immune microenvironment of human fracture/soft-tissue hematomas and its relationship to systemic immunity.

The immune environment of human soft-tissue injury is unstudied. We studied fracture soft-tissue hematomas (FxSTH) in 56 patients with high-energy bony fractures. FxSTH serum and mononuclear cells (MNC) as well as fracture patient plasma and blood MNC were studied. Twenty healthy controls donated plasma and MNC. Soluble tumor necrosis factor (TNF)-alpha, interleukin (IL-1 beta, IL-2, 6, 8, 10, 12, and interferon-gamma were studied by enzyme linked immunosorbent assay. Cells were studied by flow cytometry after cell-membrane stains for CD-14, TNF-alpha (mTNF), and human leukocyte antigen-DR, or intracellular stains for TNF (icTNF) and IL-10. Thirty-six patients with Injury Severity Score < 15 were analyzed further to evaluate the effects of isolated fracture on systemic immunity. Cytokines were rarely detectable in control plasma. TNF-alpha, IL-1 beta, IL-2, and interferon-gamma were rarely found in FxSTH serum or fracture patient plasma. All FxSTH sera were rich in IL-6, peaking before 48 hours (12,538 +/- 4,153 vs. 3,494 +/- 909 pg/mL, p = 0.02, U test). In Injury Severity Score < 15, IL-6 was not detectable in most early fracture patient plasma, but rose after 48 hours (p = 0.028). FxSTH serum IL-8 peaked after 48 hours (440 +/- 289 vs. 4,542 +/- 1,219 pg/mL, p = 0.006) and circulating IL-8 appeared after 72 hours. IL-6 and IL-8 showed gradients from FxSTH serum to paired PtS (p < 0.05, Wilcoxon). IL-10 was abundant (884 +/- 229 pg/mL) in FxSTH serum < 24 hours old. FxSTH serum IL-12 peaked late (3,323 +/- 799 pg/mL, day 4-7) then fell (p < 0.001, analysis of variance). Only IL-12 was higher in fracture patient plasma (1,279 +/- 602 pg/mL) than FxSTH serum (591 +/- 327 pg/mL) during the first 48 hours (p = 0.032, U test). On flow cytometry, control monocytes expressed 201 +/- 31 mTNF sites/cell, but icTNF was absent. mTNF was up-regulated after injury more in FxSTH monocytes (3,202 +/- 870 sites/cell) than peripheral blood monocytes (584 +/- 186 sites/cell) (p < 0.05 vs. peripheral blood monocytes by Wilcoxon, p < 0.001 vs. control monocytes by U test). Intracellular IL-10 was abundant in all MNC, but varied widely after injury. Fracture and peripheral blood monocytes expressed far less human leukocyte antigen-DR than control monocytes. Fractures create an inflammatory local environment. Proximal mediators are cell-associated and relatively confined to the wound, but soluble IL-6, IL-8, and IL-10 are abundant and probably exported. Systemic MNC have complex responses to local injuries. These may reflect the combined impact of multiple soluble cytokines initially generated within the wound. FxSTH appear to be a potentially important source of immunomodulatory cytokines in trauma.

Unstable pertrochanteric femoral fractures.

Background: Fractures in the trochanteric region of the femur are classified as AO/OTA 31-A, as they are extracapsular1 (Fig. 1). This report analyzes the relatively rare 31-A3 fracture, which has also been referred to as an “intertrochanteric femur fracture with subtrochan-teric extension,” “reverse obliquity intertrochanteric femur fracture,” “unstable intertrochanteric femur fracture,” or a “subtrochanteric femur fracture.” The A3 fracture is characterized by having a fracture line exiting the lateral femoral cortex distal to the vastus ridge. Possible fixation constructs include compression hip screws, intramedullary hip screws, trochanteric intramedullary nails, cephalomedullary antegrade intramedullary nails, and 95° plates. Most reports investigating 31-A fractures do not describe the 31-A3 fracture. For this analysis, only reports clearly indicating that the fracture treated was a 31-A3 were included. It should be understood that this approach therefore excludes reports on generic “subtrochanteric fractures” or “intertrochanteric fractures,” some of which may have been 31-A3 fractures. Objective: To determine the effect of fixation technique for the AO/OTA 31-A3 fracture on rates of union, infection, risk of reopera-tion, and functional outcomes.

Treatment of scapula fractures : Systematic review of 520 fractures in 22 case series

Background Fractures of the scapula account for 3% to 5% of all fractures of the shoulder girdle39–41 and make up less than 1% of all broken bones.42 Scapula fractures typically occur after high-energy trauma, and approximately 90% of the patients have associated injuries.39,43 Objective (1) To determine the incidences of nonoperative and operative treatment of different scapula fracture types, (2) to systematically stratify the reported results of nonoperatively and operatively treated scapula fractures on the basis of different fracture types and to summarize functional results, and (3) to quantify infection and secondary surgical procedure rates after operative treatment.