An in vivo study to investigate an original intramedullary bone graft harvesting technology.

BACKGROUND: Harvesting bone graft (BG) from the intramedullary canal to treat bone defects is largely conducted using the Reamer-Irrigator-Aspirator (RIA) system. The RIA system uses irrigation fluid during harvesting, which may result in washout of osteoinductive factors. Here, we propose a new harvesting technology dedicated to improving BG collection without the potential washout effect of osteoinductive factors associated with irrigation fluid. This novel technology involves the conceptual approach of first aspirating the bone marrow (BM) with a novel aspirator prototype, followed by reaming with standard reamers and collecting the bone chips with the aspirator (reaming-aspiration method, R-A method). The aim of this study was to assess the harvesting efficacy and osteoinductive profile of the BG harvested with RIA 2 system (RIA 2 group) compared to the novel harvesting concept (aspirator + R-A method, ARA group). METHODS: Pre-planning computed tomography (CT) imaging was conducted on 16 sheep to determine the femoral isthmus canal diameter. In this non-recovery study, sheep were divided into two groups: RIA 2 group (n = 8) and ARA group (n = 8). We measured BG weight collected from left femur and determined femoral cortical bone volume reduction in postoperative CT imaging. Growth factor and inflammatory cytokine amounts of the BGs were quantified using enzyme-linked immunosorbent assay (ELISA) methods. RESULTS: The use of the stand-alone novel aspirator in BM collection, and in harvesting BG when the aspirator is used in conjunction with sequential reaming (R-A method) was proven feasible. ELISA results showed that the collected BG contained relevant amounts of growth factors and inflammatory cytokines in both the RIA 2 and the ARA group. CONCLUSIONS: Here, we present the first results of an innovative concept for harvesting intramedullary BG. It is a prototype of a novel aspirator technology that enables the stepwise harvesting of first BM and subsequent bone chips from the intramedullary canal of long bones. Both the BG collected with the RIA 2 system and the aspirator prototype had the capacity to preserve the BG's osteoinductive microenvironment. Future in vivo studies are required to confirm the bone regenerative capacity of BG harvested with the innovative harvesting technology.

Failure of locked design-specific plate fixation of the pubic symphysis: a report of six cases.

OBJECTIVES: Physiological pelvic motion has been known to lead to eventual loosening of screws, screw breakage, and plate breakage in conventional plate fixation of the disrupted pubic symphysis. Locked plating has been shown to have advantages for fracture fixation, especially in osteoporotic bone. Although design-specific locked symphyseal plates are now available, to our knowledge, their clinical use has not been evaluated and there exists a general concern that common modes of failure of the locked plate construct (such as pullout of the entire plate and screws) could result in complete and abrupt loss of fixation. The purpose of this study was to describe fixation failure of this implant in the acute clinical setting. DESIGN: Retrospective analysis of multicenter case series. SETTING: Multiple trauma centers. PATIENTS: Six cases with failed fixation, all stainless steel locked symphyseal plates and screws manufactured by Synthes (Paoli, PA) and specifically designed for the pubic symphysis, were obtained from requests for information sent to orthopaedic surgeons at 10 trauma centers. A four-hole plate with all screws locked was used in 5 cases. A six-hole plate with 4 screws locked (two in each pubic body) was used in one. INTERVENTION: Fixation for disruption of the pubic symphysis using an implant specifically designed for this purpose. MAIN OUTCOME MEASUREMENTS: Radiographic appearance of implant failure. RESULTS: Magnitude of failure ranged from implant loosening (3 cases), resulting in 10-mm to 12-mm gapping of the symphyseal reduction, to early failure (range, 1-12 weeks), resulting in complete loss of reduction (3 cases). Failure mechanism included construct pullout, breakage of screws at the screw/plate interface, and loosening of the locked screws from the plate and/or bone. Backing out of the locking screws resulting from inaccurate insertion technique was also observed. CONCLUSIONS: Failure mechanisms of locked design-specific plate fixation of the pubic symphysis include those seen with conventional uniplanar fixation as well as those common to locked plate technology. Specific indications for the use of these implants remain to be determined. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Percutaneous placement of iliosacral screws without electrodiagnostic monitoring.

BACKGROUND: Iliosacral screws are commonly used for fixation of pelvic ring injuries. Previous reports using different screw insertion techniques have reported high neurologic complication rates, leading to recommendations for intraoperative neurodiagnostic monitoring. The purpose of this study was to evaluate the neurologic complications after percutaneous iliosacral screw placement without neurodiagnostic monitoring. METHODS: During a 21-month period, 326 patients with pelvic ring disruptions were treated at a level 1 trauma center. One hundred seventy-four patients underwent percutaneous stabilization of their pelvic ring injuries without neurodiagnostic monitoring. Patients who were not intubated preoperatively, were neurologically normal, and who underwent a closed reduction were included. Sixty-eight patients who had 106 screws placed met the inclusion criteria and formed the study group. A careful and detailed neurologic examination was performed preoperatively and postoperatively. Plain pelvic radiographs and computed tomography scans were evaluated postoperatively in all patients to assess screw position. RESULTS: No planned screw placement was abandoned because of inadequate fluoroscopic visualization. There were no neurologic injuries as a result of either the closed reduction or the screw placement. Computed tomography scans confirmed the screw position and demonstrated placement as intraosseous in 75 (70.8%) and juxtaforaminal in 31 (29.2%). No screws perforated a nerve root tunnel, spinal canal, or sacral cortex. CONCLUSIONS: Using a standardized technique, appropriate and reliable fluoroscopic landmarks are available in the vast majority of percutaneous iliosacral screw fixation procedures. Iliosacral screw placement without neurodiagnostic monitoring has a low rate of neurologic complications.

The association between supracondylar-intercondylar distal femoral fractures and coronal plane fractures.

BACKGROUND: Isolated coronal plane fractures of the distal femoral condyles (Hoffa fractures) occur uncommonly, are difficult to diagnose, and may be challenging to treat. The combination of supracondylar distal femoral fractures and these coronal plane fractures is thought to occur rarely. The purposes of the present study were to identify the frequency of the association between supracondylar-intercondylar distal femoral fractures and coronal fractures of the femoral condyle and to describe the radiographic evaluation of these injuries. METHODS: One hundred and eighty-nine patients with 202 supracondylar-intercondylar distal femoral fractures were retrospectively evaluated clinically and radiographically. RESULTS: Coronal plane fractures were diagnosed in association with seventy-seven (38.1%) of the 202 supracondylar-intercondylar distal femoral fractures. Fifty-nine (76.6%) of these coronal fractures involved a single condyle, and eighteen involved both the medial and lateral femoral condyles. Eighty-five percent of the coronal fractures involving a single condyle were located laterally. Patients with an open distal femoral fracture were 2.8 times more likely to have a coronal plane fracture than patients with a closed fracture were (95% confidence interval, 1.54 to 5.25). Coronal plane fractures were diagnosed in 47% of the 102 knees that were evaluated with computerized tomography, compared with 29% of the 100 knees that were not (p = 0.008). Ten coronal plane fractures that had been unrecognized preoperatively were identified only at the time of operative fixation of the distal femoral fracture; none of these fractures occurred in patients who had been evaluated with computerized tomographic scanning preoperatively. CONCLUSIONS: Coronal plane fractures frequently occurred in association with high-energy supracondylar-intercondylar distal femoral fractures; in the present study, the prevalence of associated coronal plane fractures was 38%. The lateral condyle was involved more frequently than the medial condyle was. Coronal plane fractures of both condyles were observed commonly, and the majority of coronal plane fractures were associated with open wounds. Since the surgical tactic for the treatment of a supracondylar-intercondylar distal femoral fracture may be altered by the additional diagnosis of a coronal plane fracture component, preoperative computerized tomographic scanning of the injured distal part of the femur, particularly when there is an associated open wound, is strongly recommended.