Use of the 'reamer irrigator aspirator' system for non-infected tibial non-union after failed iliac crest grafting

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.

Complications associated using the reamer-irrigator -aspirator (RIA) system: a systematic review and meta-analysis

INTRODUCTION

Complications associated with the application of the Reamer-irrigator-Aspirator (RIA) system are described in the literature. However, to date a systematic review and meta-analysis to assess prevalence of complications associated with the use of the RIA system have not been conducted.

MATERIALS AND METHODS

The review is registered with PROSPERO (CRD42021269982). MEDLINE, the Web of Science Core Collection, and Embase were searched from the inception to 10 August 2021. The primary objective was to assess complications and blood loss associated with the use of the RIA system.

RESULTS

Forty-seven studies involving 1834 procedures performed with the RIA system were finally included. A total of 105 complications were reported, with a pooled estimated overall prevalence of 1.7% with a 95% confidence interval (CI) of 0.40 to 3.60, with cortex perforation being the largest reported complication with a total of 34 incidences. A significant subgroup difference was observed (p = 0.02). In subgroup 1 (bone graft harvesting), complication prevalence was 1.4% (95% CI 0.2-3.4); in subgroup 2 (clearance intramedullary canal) it was 0.7% (95% CI 0.00-6.30) and in subgroup 3 (reaming with RIA system prior to nail fixation) 11.9% (95% CI 1.80-26.40). No statistically significant difference for tibia and femur as RIA system application site was observed (CI 0.69-4.19). In studies reporting blood loss, a mean volume of 803.29 ml, a mean drop of hemoglobin of 3.74 g/dl and a necessity of blood transfusion in 9.72% of the patients were observed.

CONCLUSIONS

The systematic review and meta-analysis demonstrate a low overall prevalence rate of complications associated with the RIA system. However, especially the risk of cortical perforation and the frequently reported relevant intraoperative blood loss are complications that should be anticipated in perioperative management and ultimately considered when using the RIA system.

Fusion Revision Surgery With Reamer-Irrigator-Aspirator to Harvest Autograft After Spinal Pseudarthrosis

Background and purpose

Spinal pseudarthrosis (SPA) is a common complication after attempted cervical or lumbosacral spinal fusion surgery. Revision surgeries usually necessitate bone graft implementation as an adjunct to hardware revision. Iliac crest bone graft is the gold standard but availability can be limited and usage often leads to persistent postoperative pain at the donor site. There is scant literature regarding the use of reamer-irrigator-aspirator (RIA)-harvested bone graft in lumbar spinal fusion. This is a collaborative study between orthopedic surgery and neurosurgery departments to utilize femur intramedullary autograft harvested using the RIA system as an adjunct graft in SPA revision surgeries.

Materials and methods

A retrospective review was conducted at a single center between August 2014 and December 2017 of patients aged ≥ 18 years and diagnosed with cervical, thoracic, or lumbar SPA who underwent revision fusion surgery using femur intramedullary autograft harvested using the RIA system. Plain radiographs and CT scans were utilized to confirm successful fusion.

Results

Eleven patients underwent 12 SPA revision surgeries using the RIA system as a source for bone graft in addition to bone morphogenetic protein 2 (BMP-2) and allograft. The mean amount of graft harvested was 51.3 mL (range: 20-70 mL). Nine patients achieved successful fusion (81.8%). The average time to fusion was 9.1 months. Four patients (36.4%) had postoperative knee pain. Regarding patient position and approach for harvesting, 66.7% (n = 8) of cases were positioned prone and a retrograde approach was utilized in 91.7% (n = 11) of cases.

Interpretation

This is the first case series in known literature to report the RIA system as a reliably considerable source of autologous bone graft for SPA revision surgeries. It provides a useful adjunct to the known types of bone grafts. Patient positioning and the approach choice for graft harvesting can be adjusted according to the fusion approach and the surgeon’s preference.

The effect of enhanced bone marrow in conjunction with 3D-printed PLA-HA in the repair of critical-sized bone defects in a rabbit model

Background

Traditionally, the iliac crest has been the most common harvesting site for autologous bone grafts; however, it has some limitations, including poor bone availability and donor-site morbidity. This study sought to explore the effect of enhanced bone marrow (eBM) in conjunction with three-dimensional (3D)-printed polylactide–hydroxyapatite (PLA-HA) scaffolds in the repair of critical-sized bone defects in a rabbit model.

Methods

First, 3D-printed PLA-HA scaffolds were fabricated and evaluated using micro-computed tomography (µCT) and scanning electron microscopy (SEM). Twenty-seven New Zealand white rabbits were randomly divided into 3 groups (n=9 per group), and the defects were treated using 3D-printed PLA-HA scaffolds (the PLA-HA group) or eBM in conjunction with 3D-printed PLA-HA scaffolds (the PLA-HA/eBM group), or were left untreated (the control group). Radiographic, µCT, and histological analyses were performed to evaluate bone regeneration in the different groups.

Results

The 3D-printed PLA-HA scaffolds were cylindrical, and had a mean pore size of 500±47.1 µm and 60%±3.5% porosity. At 4 and 8 weeks, the lane-sandhu X-ray score in the PLA-HA/eBM group was significantly higher than that in the PLA-HA group and the control group (P<0.01). At 8 weeks, the µCT analysis showed that the bone volume (BV) and bone volume/tissue volume (BV/TV) in the PLA-HA/eBM group were significantly higher than those in the PLA-HA group and the control group (P<0.01). Hematoxylin and eosin staining indicated that the new bone area in the PLA-HA/eBM group was significantly higher than that in the PLA-HA group and the control group (P<0.01).

Conclusions

The group that was treated with eBM in conjunction with 3D-printed PLA-HA showed enhanced bone repair compared to the other 2 groups. PLA-HA/eBM scaffolds represent a promising way to treat critical-sized bone defects.

Expression of VEGF in Peripheral Serum Is a Possible Prognostic Factor in Bone-Regeneration via Masquelet-Technique-A Pilot Study

Two-step Masquelet-technique established a new procedure in the treatment of osseous defects, addressing prerequisites postulated by the “diamond concept”. Increase in blood perfusion and growth factors are enhanced by the “Masquelet-membrane”. To describe this, we measured serum levels of Vascular Endothelial Growth Factor (VEGF) of patients with atrophic non-unions of long bones undergoing Masquelet-technique. From over 500 non-union patients undergoing Masquelet-technique with prospective follow-up we randomly selected 30 patients. 23 were included, 7 lost to follow-up or excluded because of incomplete data. Serum was drawn at specified intervals before and after surgery. Patients were followed for at least 6 months after step 2. Classification into both groups was performed according to radiological results and clinical outcome 6 months after step 2. Concentration of VEGF in patients’ serum was performed via ELISA. 14 achieved osseous consolidation (responder group), 9 cases did not (non-responder). Responders showed a significant increase of serum-VEGF in the first and second week when compared to the preoperative values of step 1. Non-responders showed a significant increase of VEGF in the second week after Steps 1 and 2. Comparison of groups showed significantly higher increase of serum-VEGF week2 after step 1 and preoperative to step 2 for responders. Results show one possibility of illustrating therapeutic progress by monitoring growth factors and possibly allowing prognostic conclusions thereof. This might lead to a more targeted treatment protocol.

Convergence of scaffold-guided bone regeneration and RIA bone grafting for the treatment of a critical-sized bone defect of the femoral shaft

BACKGROUND

Critical-sized bone defects, mainly from trauma, infection or tumor resection are a challenging condition, often resulting in prolonged, complicated course of treatment. Autografts are considered as the gold standard to replace lost bone. However, limited amount of bone graft volume and donor-site morbidity have established the need for the development of alternative methods such as scaffold-based tissue engineering (TE). The emerging market of additive manufacturing (3D-printing) has markedly influenced the manufacturing of scaffolds out of a variety of biodegradable materials. Particularly medical-grade polycaprolactone and tricalcium phosphate (mPCL-TCP) scaffolds show appropriate biocompatibility and osteoconduction with good biomechanical strength in large preclinical animal models. This case report aims to show first evidence of the feasibility, safety, and efficacy of mPCL-TCP scaffolds applied in a patient with a long bone segmental defect.

CASE PRESENTATION

The presented case comprises a 29-year-old patient who has suffered a left-sided II° open femoral shaft fracture. After initial external fixation and subsequent conversion to reamed antegrade femoral nailing, the patient presented with an infection in the area of the formerly open fracture. Multiple revision surgeries followed to eradicate microbial colonization and attempt to achieve bone healing. However, 18 months after the index event, still insufficient diaphyseal bone formation was observed with circumferential bony defect measuring 6 cm at the medial and 11 cm at the lateral aspect of the femur. Therefore, the patient received a patient-specific mPCL-TCP scaffold, fitting the exact anatomical defect and the inserted nail, combined with autologous bone graft (ABG) harvested with the Reamer-Irrigator-Aspirator system (RIA-Synthes®) as well as bone morphogenetic protein-2 (BMP-2). Radiographic follow-up 12 months after implantation of the TE scaffold shows advanced bony fusion and bone formation inside and outside the fully interconnected scaffold architecture.

CONCLUSION

This case report shows a promising translation of scaffold-based TE from bench to bedside. Preliminary evidence indicates that the use of medical-grade scaffolds is safe and has the potential to improve bone healing. Further, its synergistic effects when combined with ABG and BMP-2 show the potential of mPCL-TCP scaffolds to support new bone formation in segmental long bone defects.

Intramedullary reaming and irrigation and antibiotic-loaded calcium sulfate implantation for the treatment of infection after intramedullary nailing: a retrospective study of 19 cases

Background

The incidence of intramedullary infection is increasing with increased use of intramedullary fixation for long bone fractures. However, appropriate treatment for infection after intramedullary nailing is unclear. The purpose of this study was to report the results of our treatment protocol for infection after intramedullary nailing: intramedullary nail removal, local debridement, reaming and irrigation, and antibiotic-loaded calcium sulfate implantation with or without segmental bone resection and distraction osteogenesis.

Methods

We retrospectively reviewed the records of patients with an infection after intramedullary nailing treated from 2014 to 2017 at our center. Patients with follow-up of less than 24 months, received other treatment methods, or those with serious medical conditions were excluded from the analysis. Patients met the criteria were treated as described above, followed by distraction osteogenesis in 9 cases to repair bone defect. The infection remission rate, infection recurrence rate, and post-operative complication rates were assessed.

Results

A total of 19 patients were included in the analysis. All of patients had satisfactory outcomes with an average follow-up of 38.1 ± 9.4 months (range, 24 to 55 months). Eighteen patients (94.7%) achieved infection remission; 1 patient (5.3%) developed a reinfection that resolved after repeat debridement. Nine patients with bone defects (average size 4.7 ± 1.3 cm; range, 3.3 to 7.6 cm) were treated with bone transport which successfully restored the length of involved limb. The mean bone transport duration was 10.7 ± 4.0 months (range, 6.7 to 19.5 months). The majority of patients achieved full weight bearing and became pain free during the follow-up period. Postoperative complications mainly included prolonged aseptic drainage (7/19; 36.8%), re-fracture (1/19; 5.3%) and joint stiffness, which were successfully managed by regular dressing changes and re-fixation, respectively.

Conclusion

Intramedullary nail removal, canal reaming and irrigation, and antibiotic-loaded calcium sulfate implantation (with or without distraction osteogenesis) is effective for treating infections after intramedullary nailing.

Can the Reamer/Irrigator/Aspirator System replace anterior iliac crest grafting when treating long bone nonunion?

INTRODUCTION

Autologous bone graft is the gold standard for filling bone defects associated with diaphyseal nonunions. It is typically harvested from the anterior iliac crest (AIC) despite the high complication rate. The Reamer/Irrigator/Aspirator System (RIA) was developed to recover the reaming aspirate and use it as autograft. Initially described for harvesting bone from the femur, the bone volume available is similar to the AIC site; however, its use directly at nonunion sites has been studied very little.

HYPOTHESES

Compared to AIC harvesting, RIA at a non-union site will result in (1) sufficient bone volume, (2) similar time to union and union rate, (3) lower morbidity.

RESULTS

Two groups of patients received an autograft for aseptic nonunion of the tibia or femur for a bone defect up to 2cm: the RIA group (n=30) was followed prospectively and received an autograft by RIA while the AIC group (n=29) was reviewed retrospectively and received an autograft by AIC. We compared the time to union and union rate, operative time, intake of analgesics, duration of hospital stay and complication rate between groups. The RIA provided sufficient bone, 60cm³ on average in a reliable manner. The union rate was similar between groups: 90% (RIA) and 89.7% (CIA) (p=0.965), while the time to union was shorter in the RIA group (8.63±1.47months vs. 10.08±1.7 months) (p=0.006). The operative time (p<0.0001), analgesic intake (p=0.013), length of stay (p<0.0001) and immediate complication rate (p=0.0195) were higher in the AIC group.

DISCUSSION

For the treatment of aseptic long bone nonunion, autograft harvested by the RIA from the nonunion site results in similar union rate and time to union as AIC grafts without additional complications.

LEVEL OF EVIDENCE

IV, comparative retrospective study.

Autograft, Allograft, and Bone Graft Substitutes: Clinical Evidence and Indications for Use in the Setting of Orthopaedic Trauma Surgery

Bone grafts are the second most common tissue transplanted in the United States, and they are an essential treatment tool in the field of acute and reconstructive traumatic orthopaedic surgery. Available in cancellous, cortical, or bone marrow aspirate form, autogenous bone graft is regarded as the gold standard in the treatment of posttraumatic conditions such as fracture, delayed union, and nonunion. However, drawbacks including donor-site morbidity and limited quantity of graft available for harvest make autograft a less-than-ideal option for certain patient populations. Advancements in allograft and bone graft substitutes in the past decade have created viable alternatives that circumvent some of the weak points of autografts. Allograft is a favorable alternative for its convenience, abundance, and lack of procurement-related patient morbidity. Options include structural, particulate, and demineralized bone matrix form. Commonly used bone graft substitutes include calcium phosphate and calcium sulfate synthetics-these grafts provide their own benefits in structural support and availability. In addition, different growth factors including bone morphogenic proteins can augment the healing process of bony defects treated with grafts. Autograft, allograft, and bone graft substitutes all possess their own varying degrees of osteogenic, osteoconductive, and osteoinductive properties that make them better suited for different procedures. It is the purpose of this review to characterize these properties and present clinical evidence supporting their indications for use in the hopes of better elucidating treatment options for patients requiring bone grafting in an orthopaedic trauma setting.

Contrast-Enhanced Ultrasound Quantifies the Perfusion Within Tibial Non-Unions and Predicts the Outcome of Revision Surgery

Vascularity is one of the factors determining successful bone regeneration. This prospective study focused on quantifying the microperfusion of tibial non-unions with contrast-enhanced ultrasound (CEUS) 12 wk after revision surgery and comparing it with the osseous consolidation at a maximum of 24 mo assessed with standard radiography and computed tomography. Of 36 patients with tibial non-unions, 28 (77.8%) manifested consolidation, and 8 patients required further revision surgery. CEUS revealed significantly higher perfusion in consolidated versus persistent non-unions for all quantification parameters (e.g., wash-in perfusion index p = 0.036). Receiver operating characteristic analysis revealed a sensitivity of 82.1% and specificity of 75.0% with a wash-in perfusion index cutoff at 19.9 a.u. for diagnosing persisting non-unions. More than 1 y ahead of the final radiologic diagnostic examination, CEUS could predict eventual consolidation based on the osseous perfusion as soon as 12 wk postoperatively. This information can be crucial for the decision-making process for re-revision at an early stage.

Safety study: is there a pathologic IGF-1, PDGF and TGF-β cytokine expression caused by adjunct BMP-7 in tibial and femoral non-union therapy?

Background

In this prospective safety study, we investigated if the characteristic cytokine expression during bone regeneration is manipulated by the local application of bone morphogenetic protein-7 (BMP-7) in non-union surgery. Therefore, the levels of insulin like growth factor 1 (IGF-1), platelet-derived growth factor AB (PDGF-AB) and transforming growth factor beta (TGF-β) were compared between patients with the gold standard use of autologous bone graft (ABG) and those with additional application of BMP-7 as part of the diamond concept.

Patients and methods

Between 2009 and 2014, of the 153 patients with tibial and femoral non-unions, a matched pair analysis was performed to compare the serological cytokine expressions. Blood samples were collected preoperatively, 1, 2 and 6 weeks as well as 3 and 6 months after non-union surgery. Matching criteria were smoking status, fracture location, gender, age and body mass index (BMI). Patients in G1 (n=10) were treated with ABG and local BMP-7 while their matching partners in G2 (n=10) received ABG only. The routine clinical and radiologic follow-up was 1 year.

Results

Although the IGF-1 quantification in G2 showed higher pre- and postoperative values compared to G1 (p<0.05), the courses of both groups were similar. Likewise, PDGF-AB and TGF-β expressions appeared similar in G1 and G2 with peaks in both groups at 2 weeks follow-up. Osseous consolidation was assessed in all operated non-unions. The adjunct application of BMP-7 did not cause any pathologic cytokine expression.

Conclusion

Similar expressions of the serum cytokines IGF-1, PDGF-AB and TGF-β were demonstrated in non-union patients treated with ABG and additional application of BMP-7 according to the diamond concept. Our findings indicate that the local application of BMP-7, which imitates the physiologic secretion of growth factors during bone regeneration, is safe and without the risk of abnormal systemic cytokine expression. Studies with higher patient numbers will have to validate these assumptions.

Extended applications of the reamer-irrigator-aspirator (RIA) system

While the RIA system was initially designed for reaming and clearing the femoral canal contents in preparation for femoral nailing, it has since been used in various other applications in the field of orthopaedic surgery. The RIA is an ideal device for accessing large quantities of autogenous bone graft, to be used in the treatment of nonunions, segmental bone loss, or arthrodesis. The RIA has also been used for treatment of intramedullary infections and osteomyelitis, as well as intramedullary nailing of long bones with metastatic lesions, as it allows for clearing the canal of infectious/tumour burden, and lowers the risk of dissemination into the soft tissues and systemic circulation. There is also some limited evidence that the RIA may be used for clearing the femoral/tibial canal of cement debris. Despite multiple applications, the use of RIA has a risk of eccentric reaming and iatrogenic fractures. RIA is also a costly procedure, and its routine use may not be advantageous in the setting of limited health care resources.

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the prediction of non-union consolidation

INTRODUCTION

Non-union perfusion can be visualized with dynamic contrast-enhanced (DCE) MRI. This study evaluated DCE-MRI to predict non-union consolidation after surgery and detect factors that affect bone healing.

MATERIALS AND METHODS

Between 2010 and 2015 non-union perfusion was prospectively quantified in 205 patients (mean age, 51.5 years, 129 men, 76 women) before intervention and at 6, 12, 26, 52 and more weeks follow-up. DCE-MRI results were related to the osseous consolidation, the ability to predict successful outcome was estimated by ROC analysis. The relevance of the body mass index (BMI) and the non-union severity score (NUSS) to the healing process was assessed.

RESULTS

Tibial (n=99) and femoral (n=76) non-unions were most common. Consolidation could be assessed in 169 patients, of these 103 (61%) showed eventual healing and demonstrated higher perfusion than in failed consolidation at 6 (p=0.0226), 12 (p=0.0252) and 26 (p=0.0088) weeks follow-up. DCE-MRI at 26 weeks follow-up predicted non-union consolidation with a sensitivity of 75% and a specificity of 87% (false classification rate 19%). Higher BMI (p=0.041) and NUSS (p<0.0001) were associated with treatment failure.

CONCLUSIONS

DCE-MRI perfusion analysis after non-union surgery predicts successful outcome and could facilitate the decision of early intervention. NUSS and BMI are important prognostic factors concerning consolidation.

Quantification of TGF-ß1, PDGF and IGF-1 cytokine expression after fracture treatment vs. non-union therapy via masquelet

INTRODUCTION

Biochemical processes during bone regeneration can be analysed via quantification of peripheral serum cytokine levels. To date, serum levels of cytokines in patients treated with masquelet technique and patients with normal bone healing have not been compared. This comparison is supposed to deliver novel insights into the process of bone regeneration. Our aim was to validate this established method in the monitoring of bone regeneration after non-union treatment in masquelet technique.

MATERIALS AND METHODS

Between 04/2008 and 01/2014 three groups were recruited: G1 (10 patients) with long bone non-unions, treated successfully with masquelet therapy, G2 (6 patients) with unsuccessful masquelet therapy and G3 (10 patients) with long bone fractures and normal bone healing. Peripheral blood samples were collected over a period of six months following a standardised time pattern in combination with clinical and radiologic follow up. TGF-ß1, PDGF-AB and IGF-1 were measured using commercially available immunoassays.

RESULTS

TGF-ß1 levels in G1 and G2 demonstrated a parallel and lower overall concentration over time compared to G3. G3 showed a significant TGF-ß1 peak 2 weeks after surgery compared to G1 (p=0.0054). PDGF-AB concentrations were always lower in G2 than in G1 and G3. G3 peaked at week 2 with a significant higher value than in G2 (p=0.0177). IGF-1 showed lower overall serum concentrations in G2 than in G1 and G3. G1 had a peak level during the fourth week of follow-up. Compared to G2 this peak was significant (p=0.0015).

CONCLUSIONS

This study shows that successful bone regeneration via masquelet technique only partially imitates cytokine expression of physiological bone healing. High expressions of IGF-1 correspond to a successful masquelet therapy while TGF-ß seems to play a minor role. These results assume that objective analysis of an effective non-union therapy with cytokine expression analysis is possible even with a small number of patients.

RIA fractions contain mesenchymal stroma cells with high osteogenic potency

INTRODUCTION

The gold standard for treatment of non-union is the transplantation of autologous bone from iliac crest. As an alternative, material can be harvested by femoral reaming with the Reamer-Irrigator-Aspirator(®) (RIA)-System. This material might be a source for human mesenchymal stroma cells (MSCs) with osteogenic potency. The aim of this study was the characterisation of cells harvested with the RIA system and the comparison of their properties with cells isolated from bone marrow ("BM") and fat tissue ("adipose"). The RIA material was separated into the liquid aspiration fraction ("liquid") and the solid RIA fraction. From the solid RIA fraction the cells were cultured either directly ("native") or after collagenase digestion and filtration ("filtrate"). Stem cell characteristics were analysed and the osteogenic potential was investigated in vitro and in vivo.

MATERIALS & METHODS

Fat tissue and bone marrow were harvested from nine patients (three women, six males, with a mean of 48.1 years) with atrophic non-union RIA material. The cells were isolated and characterised by flow cytometry, three lineage differentiation capacities and colony-forming unit fibroblast assay. Gene expression profiles were performed and osteogenic differentiation in vivo was analysed.

RESULTS

All three RIA fractions contained mesenchymal stromal cells (MSCs) as demonstrated by CFU-F assay, three linage differentiation and surface marker analysis. The RIA-MSCs exhibited a significantly higher osteogenic potential in vitro compared to adipose-MSCs, whereas no difference was seen compared to BM-MSCs. Quantitative RT-PCR analysis revealed an expression of osteogenic markers in all isolated cells. The implantation of MSCs with β-TCP scaffolds into the mice muscle showed significantly higher bone formation for the filtrate RIA-MSC, native RIA-MSC and BM-MSC groups compared to the adipose-MSC group. The filtrate RIA-MSCs formed twice as much new bone in vivo compared to BM-MSCs.

CONCLUSION

The present study showed high potency of cells isolated by reaming. Even in the irrigation fluid, which is normally discarded, cells with the characteristics of stromal stem cells were isolated. In comparison to adipose-MSCs and BM-MSCs, the RIA-MSCs showed a similar or even better osteogenic potential in vitro and in vivo and this supports their usability in orthopaedic surgery.

A radiographic and clinical comparison of reamer-irrigator-aspirator versus iliac crest bone graft in ankle arthrodesis

PURPOSE

We evaluated radiographic fusion at follow-up and complication rates in patients who had either iliac crest (ICBG) or femoral reamer-irrigator-aspirator (RIA) bone graft for tibiotalar fusion.

METHODS

We retrospectively reviewed charts and radiographs of all patients who had a tibiotalar fusion from August 2007 to February 2011. Records were analysed for patient demographics, complications, and clinical symptoms. Radiographs were reviewed in sequential order by two fellowship-trained foot and ankle surgeons and one orthopaedic surgeon who specialises in foot and ankle surgery to determine radiographic fusion at routine follow-up. Patients were contacted to determine current visual analog scores (VAS) at their graft site.

RESULTS

Mean patient age was 49.4 ± 12.1 years in the RIA group and 49.3 ± 15.4 years in the ICBG group (p = .97). Pre-operative characteristics showed no significant differences between groups. The ICBG group had significantly more nonunions than the RIA group (six vs. one, p = 0.04). Two patients in the ICBG had chronic pain at their graft site based on their VAS score; there were none in the RIA group. Radiographic fusion at follow-up was similar between groups, with no significant difference (12.48 ± 3.85 weeks vs.12.21 ± 3.19 weeks, p = .80).

CONCLUSIONS

There was a significantly higher nonunion rate in the ICBG group, but both groups had a solid radiographic bony fusion at similar follow-up time points. Our results suggest RIA bone graft is a viable alternative to ICBG for tibiotalar fusion.

More adverse events than expected in the outcome after use of the reamer-irrigator-aspirator

PURPOSE

The reamer-irrigator-aspirator (RIA) system is described as having high success rates and only few complications. The RIA was originally designed to ream the intramedullary canal in a single step prior to the placement of an intramedullary nail for femur fixation. Its purpose was to collect and evacuate marrow contents during reaming to prevent embolism into the systemic circulation. Marrow evacuation is also used to stimulate healing in nonunion fractures, segmental bone defects, and osteomyelitis. Despite the described success rates, we experienced severe adverse events. Our aim was to describe these events and point out possible complications.

METHODS

A retrospective study of all consecutive patients treated for nonunion fractures, bone defects, or osteomyelitis from October 2007 to March 2010. All patients were treated with the RIA system. We analyzed demographic characteristics, consolidation on X-rays, time from injury to healing, complications, and postoperative pain caused by the reaming procedure.

RESULTS

We included 32 patients (21 males) with an average follow-up of 277 days. Successful healing was achieved in 66 % of all patients, and 18 % suffered from postoperative pain. A complication due to the use of the RIA system was registered in 31 % of the patients. Recorded complications were bone defects, signs of lung embolism, a myocardial infarction, and fissure fractures.

CONCLUSIONS

The RIA system has benefits in the treatment of nonunion and osteomyelitis defect, but is not without risk. Meticulous surgical technique is mandatory and peroperative constant monitoring of patients and the assembled device is mandatory.

Donor site morbidity with reamer-irrigator-aspirator (RIA) use for autogenous bone graft harvesting in a single centre 204 case series

Donor site morbidity and complication rate using the reamer-irrigator-aspirator (RIA) system for intramedullary, non-structural autogenous bone graft harvesting were investigated in a retrospective chart and radiographic review at a University affiliated Level-1 Trauma Centre. 204 RIA procedures in 184 patients were performed between 1/1/2007 and 12/31/2010. RIA-indication was bone graft harvesting in 201 (98.5%), and intramedullary irrigation and debridement in 3 (1.5%) cases. Donor sites were: femur - antegrade 175, retrograde 4, tibia - antegrade 7, retrograde 18. Sixteen patients had undergone two RIA procedures, two had undergone three procedures, all using different donor sites. In 4 cases, same bone harvesting was done twice. Mean volume of bone graft harvested was 47 ± 22ml (20-85 ml). The complication rate was 1.96% (N=4). Operative revisions included 2 retrograde femoral nails for supracondylar femur fractures 6 and 41 days postoperatively (antegrade femoral RIA), 1 trochanteric entry femoral nail (subtrochanteric fracture) 17 days postoperatively (retrograde femoral RIA) and 1 prophylactic stabilization with a trochanteric entry femoral nail for intraoperative posterior femoral cortex penetration without fracture. In our centre, the RIA technique has a low donor site morbidity and has been successfully implemented for harvesting large volumes of nonstructural autogenous bone graft.

Engineering bone grafts with enhanced bone marrow and native scaffolds

The translation of tissue engineering approaches to the clinic has been hampered by the inability to find suitable multipotent cell sources requiring minimal in vitro expansion. Enhanced bone marrow (eBM), which is obtained by reaming long bone medullary canals and isolating the solid marrow putty, has large quantities of stem cells and demonstrates significant potential to regenerate bone tissues. eBM, however, cannot impart immediate load-bearing mechanical integrity or maintain the gross anatomical structure to guide bone healing. Yet, its putty-like consistency creates a challenge for obtaining the uniform seeding necessary to effectively combine it with porous scaffolds. In this study, we examined the potential for combining eBM with mechanically strong, osteoinductive trabecular bone scaffolds for bone regeneration by creating channels into scaffolds for seeding the eBM. eBM was extracted from the femurs of adult Yorkshire pigs using a Synthes reamer-irrigator-aspirator device, analyzed histologically, and digested to extract cells and characterize their differentiation potential. To evaluate bone tissue formation, eBM was seeded into the channels in collagen-coated or noncoated scaffolds, cultured in osteogenic conditions for 4 weeks, harvested and assessed for tissue distribution and bone formation. Our data demonstrates that eBM is a heterogenous tissue containing multipotent cell populations. Furthermore, coating scaffolds with a collagen hydrogel significantly enhanced cellular migration, promoted uniform tissue development and increased bone mineral deposition. These findings suggest the potential for generating customized autologous bone grafts for treating critical-sized bone defects by combining a readily available eBM cell source with decellularized trabecular bone scaffolds.

The use of Reamer Irrigator Aspirator (RIA) autograft harvest in the treatment of critical-sized iliac wing defects in sheep: investigation of dexamethasone and beta-tricalcium phosphate augmentation

Bone grafts are commonly used for the treatment of segmental bone defects and fracture non-unions. Recently, osseous particles obtained during intermedullary canal reaming (using a Reamer-Irrigator-Aspirator (RIA) device) have been evaluated as graft material during in vitro and clinical studies. The aim of this study was to evaluate and quantify new bone formation after implantation of bone graft material obtained after reaming of the tibia in a bilateral critical-sized iliac wing defect in sheep and to investigate the effect of the augmentation of this graft. A reamer bone graft alone, or after short term incubation in a dexamethasone enriched solution, and a reamer graft collected using beta-tricalcium phosphate (β-TCP) granules in the filter of the RIA collection device were compared to autologous iliac wing graft. In addition, reamer graft was combined with the cellular fraction collected from the irrigation fluid with and without short-term incubation in a dexamethasone enriched solution. It was hypothesized that the amount of physical bone in the reamer bone graft groups would be higher than the amount in the autologous iliac wing graft group and that augmentation of a reamer bone graft would increase bone formation. Three months after implantation, the amount of new bone formation (as percentage of the total defect volume) in the defects was evaluated ex-vivo by means of micro-CT and histomorphometry. The mean amount of bone in the autologous iliac wing graft group was 17.7% and 16.8% for micro-CT and histomorphometry, respectively. The mean amount of bone in all reamer graft groups ranged between 20.4-29.2% (micro-CT) and 17.0-25.4% (histomorphometry). Reamer graft collected using β-TCP granules (29.2±1.7%) in the filter produced a significantly higher amount of bone in comparison to an autologous iliac wing graft evaluated by micro-CT. RIA bone grafts added a small increase in bone volume to the 3month graft volume in this preclinical sheep model. The current model does not support the use of short-term high concentration dexamethasone for augmentation of a graft volume. If avoidance of an iliac wing graft is desirable, or a reaming procedure is required, then a RIA graft or RIA graft plus β-TCP granules are as good as the current gold standard for this model.

[Spinal arthrodesis. basic science]

Spinal arthrodesis consists of a combination of a system of mechanical stabilisation of one or more vertebral segments with a biological substance that promotes osteoneogenesis, with aim of achieving the permanent fusion between areas more or less the same size of these segments. In spinal arthrodesis, the biological support par excellence is the autograft. However, obtaining this involves a high incidence of morbidity and, in cases of arthrodesis of more than one intervertebral space, the quantity available is usually insufficient. The extraction and implantation time prolongs the surgery, increasing the exposure to and risk of bleeding and infection. For these reasons, there is a search for substances that possess the properties of the autograft, avoiding the morbidity and added surgical time required to extract the autograft. The biomechanical-biological interaction in vertebral arthrodesis has been studied in this article.

[Therapy of chronic osteomyelitis: soft tissues as "key to success"]

Chronic osteomyelitis is a severe complication characterized by soft tissue and bone pathogenic infection resulting in osseous destruction. Surgical management is demanding and poses a challenge in achieving the goals of treatment, which are control of infection, bone healing as well as satisfactory functional outcome. Therapeutic strategies are based on a combined application of radical surgery and systemic antibiotic therapy. The bony defects which remain after extensive debridement have to be reconstructed with bone grafting after soft tissue coverage and the healing process is decisive for a successful outcome.

Complications following autologous bone graft harvesting from the iliac crest and using the RIA: a systematic review

Bone grafting is a commonly performed surgical procedure to augment bone regeneration in a variety of cases in orthopaedic and maxillofacial surgery. Autologous bone graft remains to be the 'gold standard' and the iliac crest to be the most common harvesting site. The intramedullary canal of long bones represents another potential site for large volume of autologous bone graft harvesting and is recently being used as an alternative donor site. However, harvesting of autologous bone graft is associated with morbidity and a number of complications. The aim of this systematic review was to collect and summarise the existing data on reported complications after harvesting autologous bone from the iliac crest (anterior and posterior) and the long bone intramedullary canal using the RIA device. We searched the PubMed Medline and Ovid Medline databases, from January 1990 to October 2010, to retrieve all relevant articles. A total of 92 articles (6682 patients) were included in the analysis. Overall, the complication rate following RIA was 6% (14 complications in 233 patients) and 19.37% after iliac crest bone graft harvesting (1249 complications in 6449 patients). The rate of each of the reported complications was assessed and, when the donor site was properly documented, comparison within the anterior and posterior iliac crest donor sites was performed. Although the difference of the overall morbidity rates between the two harvesting sites was not statistically significant (p=0.71); the rates of certain complications were found to significantly differ when anterior or posterior iliac crest was used. The rates of infection (p=0.016), haematoma formation (p=0.002), fracture (p=0.017), and hyperthrophic scar (p=0.017) were significantly higher when the donor site was the anterior iliac crest compared to the posterior iliac crest; whereas the rates of chronic donor site pain (p=0.004) and sensory disturbances (p=0.003) were significantly lower. The incidence of bone graft harvesting related complications can be reduced further if certain principles are followed depending on the performed harvesting methods; but overall the use of RIA device as harvesting method seems a promising alternative with a low complication rate.

What bone graft substitutes should we use in post-traumatic spinal fusion?

Surgical treatment of spinal fractures consists of postural reduction and segmental arthrodesis, together with an eventual performance of spinal canal decompression. Spinal arthrodesis consists of the combination of a hardware system for mechanical stabilisation together with a biological substance for enhancement of bone formation. To date, autologous graft is the only biological substance demonstrated to possess osteogenic properties. Cancellous bone graft has greater cellular activity than cortical graft, whereas cortical graft is stronger. Consequently, according to biological and biomechanical properties of autograft, spinal posterior arthrodesis is better enhanced by cancellous autograft, whereas anterior interbody tricortical bone is more suitable for anterior fusion. Allograft does not cause harvesting complications as autograft does, and also its amount is theoretically unlimited; nevertheless the rate of bone fusion facilitated by allograft is far from that enhanced by autograft given that allograft has no osteoprogenitor cells. There is little evidence on the efficacy of demineralised bone matrix for spinal fusion. Bone morphogenetic proteins (BMPs) are in use in spinal surgery, but their exact role with respect to type, dose, and carrier, together with their cost-effectiveness, need further clinical delineation. Calcium phosphate compounds appear to be good as carriers; however, they have no osteoinductive or osteogenic properties. Current clinical literature seem to indicate their usefulness for bony fusion in spinal surgery, when combined with bone marrow aspirate or used as an extender for autologous bone graft. Age, length of fusion, location, and concurrent diseases should be definitive for fusion outcome; papers on spinal arthrodesis should neatly stratify these variables. Unfortunately, since that is not the rule, conclusions drawn from current literature are very unreliable. Autograft remains the gold standard, and cancellous bone is advisable in posterolateral approaches, whereas tricortical iliac crest autograft appears appropriate for interbody support. In longer segments, its expansion with BMPs looks safe at least. Basic knowledge has been achieved from animal experiments, and clinical application of the findings to humans should be done very cautiously; in any case, both anterior and posterior arthrodesis must be protected with instrumentation used according to appropriate biomechanical principles. A combination of failure of the correct graft together with proper instrumentation will result in poorer outcome, even if the right graft is used.

Femoral fracture after harvesting of autologous bone graft using a reamer/irrigator/aspirator

A case of postoperative fracture in the donor femur after obtaining autologous bone graft with a reamer/irrigator/aspirator is presented. This procedure was successful in healing a difficult femoral nonunion, but the patient sustained a fracture of the contralateral (bone graft donor) femur 20 days after surgery. A mechanical analysis is conducted of this case and recommendations are made. Unrestricted weightbearing on a limb that has undergone reamer/irrigator/aspirator bone graft harvesting, particularly in a noncompliant patient, is probably inadvisable. If possible, one should obtain bone graft from the same limb as the fracture being treated because this will leave the patient with one unaltered limb for mobilization.

Reamer-irrigator-aspirator indications and clinical results: a systematic review

BACKGROUND

The 'reamer-irrigator-aspirator' (RIA) is an innovation developed to reduce fat embolism (FE) and thermal necrosis (TN) that can occur during reaming/nailing of long-bone fractures. Since its inception its indications have expanded to include the treatment of long-bone osteomyelitis and as a harvester of bone graft/mesenchymal stem cells (MSCs).

METHODS

This study involved a systematic review, via Pubmed® and Google Scholar®, of English language sources (nine non-clinical studies, seven clinical studies and seven case reports) using the keywords: 'reamer', 'irrigator', 'aspirator' (1st May 2010). Sources were reviewed with reference to the RIAs efficacy in (1) preventing FE/TN, (2) treating long-bone osteomyelitis, (3) harvesting bone graft/MSCs, and (4) operating safely. Experimental data supports the use of the RIA in preventing FE and TN, however, there is a paucity of clinical data.

CONCLUSIONS

The RIA is a reliable method in achieving high volumes of bone graft/MSCs, and high union rates are reported when using RIA bone-fragments to treat non-unions. Evidence suggests possible effectiveness in treating long-bone osteomyelitis. The RIA appears relatively safe, with a low rate of morbidity provided a meticulous technique is used. When complications occur they respond well to conventional techniques. The RIA demands further investigation especially with respect to the optimal application of MSCs for bone repair strategies.

The biology of intramedullary reaming

In this review we focus on the local biologic and physiologic effects of intramedullary reaming of long bones. Among the topics discussed are the consequences for vascularity, as well as the pathophysiology of intramedullary pressure generation and temperature increase. Reaming techniques and their suggested effects on bone formation are outlined. Moreover, techniques for avoiding local and systemic complications are summarized.

Biomechanical effects of harvesting bone graft with the Reamer/Irrigator/Aspirator on the adult femur: a cadaver study

OBJECTIVES

Test the biomechanical properties of femurs that have undergone reaming with the Reamer Irrigator Aspirator (RIA) device with an aim to prove no difference in torsional strength between matched pairs.

METHODS

Intact femurs were harvested from embalmed cadavers, representing 19 matched pairs. One femur from each pair was randomly selected to undergo reaming using the RIA to 15 mm. The bones were then cut and potted using a uniform jig for testing. Each specimen was tested in torsion and torsional stiffness was calculated for each pair. Samples were loaded until fracture or 11 3 N·m of torque.

RESULTS

Nine of the reamed specimens and 13 of the unreamed samples remained intact until the machine limit of 113 N·m was reached, representing approximately four times the peak torque of 30N·m seen with stair climbing [Garino J, Beredjiklian P. Core Knowledge in Orthopaedics: Adult Reconstruction and Arthroplasty. Chapter 1, page 33. Mosby, 2007]. Mean torsional stiffness for the reamed group was 532.1 N·m/rad (SD = 208.2), and the unreamed was 546.2 N·m/rad (SD=206). Torsional load capacity was calculated for all specimens and compared in groups in which both reamed and unreamed specimens failed. In these five groups, mean load capacity was 80.6 Nm (SD = 9.5) for the reamed group, and 85 Nm (SD = 16.1) for the unreamed group.

CONCLUSIONS

17 of our reamed specimens and all of our unreamed specimens withstood normal physiologic load seen with stair climbing. In addition, 16 of 19 reamed specimens remained intact at twice this load. The specimen in the reamed group with the lowest torsional load capacity was eccentrically reamed in the distal anterior cortex highlighting potential complications. Given these findings, reaming the cortex of the femur with the RIA device for the purpose of harvesting bone graft does not appear to dramatically diminish the mechanical properties of the cortex or require postoperative weight bearing restrictions. However, careful attention must be paid to technique as eccentric reaming either proximally or distally may result in catastrophic failure. Careful attention must be paid to the use of irrigating fluid and post operative blood loss, and a thorough discussion of risk factors including postoperative fracture should be covered when obtaining informed consent.

Randomized prospective clinical trial comparing reamer irrigator aspirator (RIA) to standard reaming (SR) in both minimally injured and multiply injured patients with closed femoral shaft fractures treated with reamed intramedullary nailing (IMN)

PURPOSE

To investigate whether inflammatory markers are improved among patients with traumatic femur fractures who undergo RIA reamed intramedullary nailing (IMN) prior to fixation when compared to patients treated with standard reamed (SR) IMN.

METHODS

A prospective, randomized, single-blind trial was conducted on patients who had a closed femoral shaft fracture amenable to reamed IMN. Patients were randomized to undergo IMN with standard reaming or IMN with the RIA in a 1:1 ratio. Patients were stratified by Injury Severity Score (ISS) and by presence or absence of chest injury with AIS > 3. Patients had blood samples and bronchioalveolar lavage samples taken at specified time points pre- and postoperatively. Specimens from SR and RIA cohorts were compared for the presence of IL-2, IL-6, IL-8, TNF, and IL-10 in plasma and IL-1b and IL-8 in bronchioalveolar lavage (BAL) samples to determine the relationship between inflammatory markers and intramedullary reaming.

RESULTS

Nineteen consecutive patients participated in the study with 9 assigned in the RIA group and 10 in SR group. Significant differences existed for ISS between SR and RIA groups (p=0.04). Bronchial lavage data showed no statistical significant differences when RIA and standard reamers were compared and when ISS >16 and <16 were compared, however there were differences for the bronchial IL-8 change when those with chest injury were compared to those without chest injury. Plasma samples showed a trend towards increased IL-6 and IL-10 levels after reaming consistent with the second hit impact. A trend towards higher levels for IL-6 in the SR group was noted at 24 hours post-operatively whereas the IL-10 levels at the post-reaming time point were higher in the RIA group.

CONCLUSIONS

This prospective study of reamer type indicates that RIA may be protective of systemic inflammation. This is supported by data showing decreased levels of IL-8 in the bronchial washings and increased level of IL-10 in the serum. Reaming and intramedullary fixation may cause an increase in IL-6 levels regardless of reamer type. Further investigations with a larger cohort of patients are desirable.

The systemic inflammatory response following femoral canal reaming using the reamer-irrigator-aspirator (RIA) device

We evaluated the peripheral release of inflammatory mediators after femoral fracture and subsequent intramedullary reaming using the RIA reamers. IL-6 was elevated after trauma, and reaming with RIA induced a measurable second hit response. However, despite a higher ISS, the levels of IL-6 in the RIA group were similar to the levels measured in a group of patients where reaming of the femoral canal was performed using conventional reamers. There was one death related to fat embolism syndrome in the conventional reamers group. However, the overall incidence of complications was low and similar between the 2 groups of studied patients. In polytrauma patients, large scale studies are desirable to evaluate further the immuno-inflammatory response using the RIA reamers prior to the instrumentation of the femoral canal.

RIA use in a community orthopedic trauma practice: applying technology, respecting biology

The RIA (Reamer Irrigator Aspirator) device is an incredibly powerful tool. It can be used to obtain biologically active tissue for healing at local or distant sites. Additionally, it can be used to lower the negative bioburden of disease and even to assist in diagnosis. As with any powerful tool, it should be used with detailed pre-planning and great respect. Once properly understood and implemented, the device can be used in many ways:

Autologous bone graft: properties and techniques

Bone grafting is involved in virtually every procedure in reconstructive orthopaedic surgery. Although autologous bone grafts have excellent biologic and mechanical properties, considerable donor site morbidity and the limited volume available must be taken into consideration. Currently, there are no heterologous or synthetic bone substitutes available that have superior biologic or mechanical properties. This review article summarizes the biologic and mechanical properties of autologous bone grafts, differentiates various autologous bone graft types, and compares them with other bone substitutes.

Soft tissue and biomechanical challenges encountered with the management of distal tibia nonunions

A thoughtful treatment algorithm is required to optimally treat distal tibia nonunion. A healthy respect for the tenuous soft tissue envelope, compromised vascularity, and challenging mechanical environment is advisable. Achieving osseous union and improved functionality requires an individualized plan of care based on the personality of the nonunion and host. Attention must be focused on providing mechanical stability at the site of nonunion and providing biologic supplementation.

Technical tricks when using the reamer irrigator aspirator technique for autologous bone graft harvesting

This report describes technical tricks for using the reamer irrigator aspirator to harvest autologous bone graft from the femur. This device is a focus of interest in orthopaedics because it can be used to harvest bone graft from the femoral canal and medial condyle in voluminous quantities. Moreover, according to some authors, the osteogenic potential of this graft is at least as effective as that of autogenous bone obtained from the iliac crest. The reamer irrigator aspirator device has substantially different design characteristics and technicalities compared with those of a standard reamer. First, a guidewire must be redirected into multiple areas, including the center of the distal femur and into both condyles, to harvest ample bone graft. This is accomplished by prebending the guidewire in a stronger fashion than required for regular reaming in the case of femoral nailing procedures. This bend can increase the risk for eccentric reaming as well as lodging of the suctioning device within the femoral canal. Second, the front and lateral drilling surfaces of this device are very sharp and further cleaned and maintained sharp by the irrigation process to permit the surgeon to obtain significant volumes of graft with a single passage of this device. At the same time, however, this sharp front-end cutting design can increase the risk of iatrogenic fracture if reaming is performed without caution. Third, a powerful suctioning device is connected to the reamer such that the blood loss that can occur during continuous reaming, irrigation, and aspiration must be considered with this technique. We hereby discuss these potential dangers and describe the correct use of this device with technical tricks to minimize the risk of unexpected intraoperative events.

Bone defects caused by high-energy injuries, bone loss, infected nonunions, and nonunions

Bone defects represent a difficult problem for the clinician. They entail a sustained increase in hospitalization, risk of complications, and associated increase in expenses. This article discusses bone defects caused by high-energy injuries, bone loss, infected nonunions, and nonunions.

Surgical techniques: how I do it? The Reamer/Irrigator/Aspirator (RIA) system

Although reamed intramedullary nailing has long been considered a safe procedure, pulmonary complications have been reported in some groups of patients. Concerns over fat embolisation, adult respiratory distress syndrome (ARDS), and sudden intraoperative death have prompted some authors to question whether the benefits of reaming are outweighed by its potential adverse effects to the patient. In response to these complications, recent evaluations have focused on alternative systems that reduce intramedullary pressure during reaming. The Reamer/Irrigator/Aspirator (RIA) system (Synthes, Inc., West Chester, PA) was developed as a simultaneous reaming and aspiration system to reduce the intramedullary pressure, heat generation, operating time, and systemic effects of reaming. It was designed with an aggressive one-pass reamer head which is connected to a hand-held reamer via a drive shaft, simultaneously irrigating and aspirating femoral canal contents during reaming, thus preventing thermal necrosis and fat embolisation. After its early use, investigators examined the "aspirate" captured by the RIA which appeared to be loaded with osteogenic substrates. This discovery revealed a second potential use for the RIA-a bone graft harvester. The different design characteristics and technicalities of the RIA system necessitate a deep and clear understanding of its technique, a meticulous preoperative planning and a strict adherence to its principles intraoperatively. We present our current approach to the use of the RIA system, including the preoperative planning, the details of the operative procedure, the pitfalls and the potential complications that could be encountered.

Bone graft harvest using a new intramedullary system

Obtaining autogenous bone graft from the iliac crest can entail substantial morbidity. Alternatively, bone graft can be harvested from long bones using an intramedullary (IM) harvesting system. We measured bone graft volume obtained from the IM canals of the femur and tibia and documented the complications of the harvesting technique. Donor site pain and the union rate were compared between the IM and the traditional iliac crest bone graft (ICBG) harvest. Forty-one patients (23 male, 18 female) with an average age of 44.9 years (range, 15-78 years) had graft harvested from long bones using an IM harvest system (femoral donor site, 37 patients; tibial donor site, four patients). Forty patients (23 male, 17 female; average age, 46.4 years; range, 15-77 years) underwent anterior ICBG harvest. We administered patient surveys to both groups to determine pain intensity and frequency. IM group reported lower pain scores than the ICBG group during all postoperative periods. Mean graft volume for the IM harvest group was 40.3 mL (range, 25-75 mL) (graft volume was not obtained for the ICBG group). Using an intramedullary system to harvest autogenous bone graft from the long bones is safe provided a meticulous technique is used.

LEVEL OF EVIDENCE

Level III, retrospective comparative study. See the Guidelines for Authors for a complete description of levels of evidence.

Innovations in osteosynthesis and fracture care

Over the years giant steps have been made in the evolution of fracture fixation and the overall clinical care of patients. Better understanding of the physiological response to injury, bone biology, biomechanics and implants has led to early mobilisation of patients. A significant reduction in complications during the pre-operative and post-operative phases has also been observed, producing better functional results. A number of innovations have contributed to these improved outcomes and this article reports on the advances made in osteosynthesis and fracture care.