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

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.

3D geometry of femoral reaming for bone graft harvesting

The reamer-irrigator-aspirator (RIA) technique allows to collect large bone graft amounts without the drawbacks of iliac crest harvesting. Nevertheless, clinical cases with occurrence of femur fractures have been reported. Therefore, this study aimed to systematically investigate the three-dimensional geometry of the reamed bone as a function of the reaming diameter and its influence on the associated potential fracture pattern. Forty-five intact fresh-frozen human cadaveric femora underwent computed tomography (CT). They were randomized to three groups (n = 15) for reaming at a diameter of either 1.5 mm (Group 1), 2.5 mm (Group 2) or 4.0 mm (Group 3) larger than their isthmus using RIA. Reaming was followed by a second CT scan, biomechanical testing until failure and a third CT scan. All CT scans of each femur were aligned via rigid registration, and fracture lines were visualized. Subsequently, a decrease in wall thickness, cross-sectional area, and harvested bone volume have been evaluated. The total volume of the bone graft was significantly higher for Group 3 (7.8 ± 2.9 ml) compared to Group 1 (2.9 ± 1.1 ml) and Group 2 (3.0 ± 1.1 ml). The maximal relative decrease of the wall thickness was located medially (72.7%) in the third (61.4%), fourth (18.2%) and second (9.1%) eighth for all groups. As the diameter of the reaming increased, an overlap of the fracture line with the maximal relative decrease in wall thickness and a maximal average relative decrease of the cross-sectional area became more frequent. This suggests that a reaming-associated fracture is most likely to occur in this region.

Autologous bone graft: Is it still the gold standard?

Bone grafting has over 100 years of successful clinical use. Despite the successes of autograft bone transplantation, complications of bone grafting are significant, mostly at the donor site. This article reviews the biology of fracture healing, the properties of bone grafts, and reviews the specific advantages and problems associated with autograft bone. Recent techniques such as the Reamer Irrigator Aspirator are described, which has dramatically reduced complications of bone autograft harvesting.

Influence of the Reamer-Irrigator-Aspirator diameter on femoral bone strength and amount of harvested bone graft - a biomechanical cadaveric study

BACKGROUND

Treatment of large bone defects is still related to unsolved problems in orthopaedic trauma surgery. Minimally invasive intramedullary reaming with the use of the Reamer-Irrigator-Aspirator (RIA) device allows autograft harvesting of large bone graft amounts from the medullary canal of the femur. The aim of this study was to investigate the influence of RIA diameter on femoral bone strength and amount of harvested bone graft in a human cadaveric model.

METHODS

Forty-five pairs human cadaveric femora were randomized to 3 paired groups with 15 pairs each. One femur of each pair was reamed with RIA at a diameter of either 1.5 mm (group 1), 2.5 mm (group 2) or 4.0 mm (group 3) larger than its isthmus, whereas its contralateral femur was left intact without reaming. The amount of harvested bone graft was determined for each specimen and all femora were destructively tested in internal rotation under 750 N axial compression to calculate their torsional stiffness and torque at failure.

RESULTS

Significant reduction in torsional stiffness was detected after reaming in group 3 (p = 0.03) in contrast to groups 1 and 2 where no such significant reduction was observed (p ≥ 0.34). Torque at failure was significantly reduced after reaming in all 3 groups (p ≤ 0.04). Collected bone graft amount in group 3 was significantly bigger compared to groups 1 and 2 (p ≤ 0.04).

CONCLUSIONS

Reaming with RIA diameter of 4.0 mm larger than the isthmus of the femur seems to influence considerably its torsional stiffness, however, it allows harvesting of a significantly bigger bone graft amount.

Influence of concentration and preparation of platelet rich fibrin on human bone marrow mononuclear cells (in vitro)

Large bone defects have always been a big challenge. The use of bone marrow mononuclear cells (BMCs) combined with an osteoconductive scaffold has been proved a good alternative for the treatment of large bone defects. Another autologous source for tissue engineering is platelet rich fibrin (PRF). PRF is a blood concentrate system obtained through a one-step centrifugation. The generated 3D matrix of the PRF clot serves as a reservoir of growth factors. Those growth factors might support the regenerative response of BMC, and therefore the effect of PRF, centrifuged with either high medium (208 g) or low (60 g) relative centrifugation force (RCF) on BMCs was evaluated in vitro in the present study. The two PRF matrices obtained were initially characterized and compared to human serum. Significantly increased concentrations of insulin-like growth factor (IGF), soluble intercellular adhesion molecule-1 (sICAM1) and transforming growth factor (TGF)-β were found in PRF compared to human serum whereas VEGF concentration was not significantly altered. A dose-response study revealed no further activation of BMC's metabolic activity, if concentration of both PRF matrices exceeded 10% (v/v). Effect of both PRF preparations [10%] on BMC was analyzed after 2, 7, and 14 days in comparison to human serum [10%]. Metabolic activity of BMC increased significantly in all groups on day 14. Furthermore, gene expression of matrix metalloproteinases (MMP)-2, -7, and -9 was significantly stimulated in BMC cultivated with the respective PRF matrices compared to human serum. Apoptotic activity of BMC incubated with PRF was not altered compared to BMC cultivated with serum. In conclusion, PRF could be used as a growth factor delivery system of autologous or allogeneic source with the capability of stimulating cells such as BMC.

Basic Science and Clinical Application of Reamed Sources for Autogenous Bone Graft Harvest

Autologous bone graft remains the only clinically available source of graft material with osteogenic, osteoinductive, and osteoconductive properties. Although iliac crest autologous bone graft has long served as the benchmark, reamed autogenous bone graft offers several advantages. Reamed autograft has a biochemical and cellular profile that is at least equivalent, and perhaps superior, to that of iliac crest autograft. In addition, larger volumes of reamed autograft can be obtained via less-invasive techniques, giving surgeons an accessible source of mesenchymal stem cells that can be reliably and repeatedly harvested. Early clinical experience involving reamed autogenous bone graft in the management of nonunion, bone defects, and arthrodesis has been encouraging and has demonstrated the necessary properties to warrant regular consideration of reamed graft for these applications.

Challenges of bone tissue engineering in orthopaedic patients

Bone defects may impede normal biomechanics and the structural stability of bone as an organ. In many cases, the correction of bone defects requires extensive surgical intervention involving the use of bone-grafting techniques and other procedures in which healing is slow, there is a high risk of infection and considerable pain is provoked - with no guarantee of complete correction of the defect. Therefore, the search for surgical alternatives continues to present a major challenge in orthopaedic traumatology. The reamer-irrigator-aspirator (RIA) system, which was devised to avoid the problems that can arise with autograft harvesting from the iliac crest, consists of collecting the product of the femoral canal after reaming. The RIA technique improves osteogenic differentiation of mesenchymal stem cells, compared to bone marrow aspiration or cancellous bone harvesting from the iliac crest using a spoon. Another approach, the Masquelet technique, consists of reconstructing a long bone defect by means of an induced membrane grown onto an acrylic cement rod inserted to fill the defect; in a second surgical step, once the membrane is constituted, the cement rod is removed and cancellous autograft is used to fill the defect. Both in RIA and in the Masquelet technique, osteosynthesis is usually needed. Bone transportation by compression-distraction lengthening principles is commonly implemented for the treatment of large bone loss. However, complications are frequently encountered with these techniques. Among new techniques that have been proposed to address the problem of large bone loss, the application of stem cells in conjunction with tissue engineering techniques is very promising, as is the creation of personalised medicine (or precision medicine), in which molecular profiling technologies are used to tailor the therapeutic strategy, to ensure the right method is applied for the right person at the right time, after determining the predisposition to disease among the general population. All of the above techniques for addressing bone defects are discussed in this paper.

Predicting Reduction in Torsional Strength by Concentric/Eccentric RIA Reaming Normal and Osteoporotic Long Bones (Femurs)

OBJECTIVES

Reamer-irrigator-aspirator (RIA) bone graft harvesting human femurs have resulted in spiral fractures. Recommendations/studies on safe RIA diameter are noncomprehensive/inconclusive. Our purpose was to develop an analytical model to predict % reduction in torsional strength after intramedullary oversize reaming (concentric or eccentric) and to test cadaveric femurs with normal-to-osteoporotic bone mineral density to investigate its relationship to femur cross-sectional properties, bone material strength, and torsional strength reduction.

METHODS

An eccentric circular cross-sectional model was developed. Twenty matched cadaveric femurs (8-normal, 6-osteopenic, and 6-osteoporotic) were tested. Left femur was reamed 1.5 mm larger than isthmic endosteal diameter measured from radiographs. Right (control) and left (reamed) femurs were torsionally loaded to failure. Periosteal-endosteal circles were fit tangent to the thinnest wall on computer tomography cross-sectional image at level of spiral fracture to determine periosteal-endosteal circle diameters (dp, de) and their eccentricity (e), and to calculate cross section's size-eccentricity factor. These and torque failure were substituted into the model to calculate bone material's effective tensile strength.

RESULTS

Osteoporotic compared with normal femurs had higher de/dp ratio (0.71 vs. 0.47), lower cross-sectional size-eccentricity factor (-41%), bone material strength (-57%), and torsional strength (-73%). Predicted % reduction in torsional strength by either concentric over reaming or canal eccentricity exponentially increases with increase in de/dp (notably beyond 0.47 of normal bone mineral density).

CONCLUSIONS

Manufacturer's recommended 1.5 mm oversize RIA is conservative (<10% reduction) if concentric in femurs with isthmus de/dp < 0.60 mm and dp > 18.3 mm. An eccentric canal can significantly compromise a long bone's torsional strength, more than if reamed concentric to larger diameter having same minimum wall thickness. Other "safe/unsafe" oversize-eccentricity conditions are in quick clinical reference tables.

Incidence of donor site morbidity following harvesting from iliac crest or RIA graft

INTRODUCTION

Clinical management of non-union of long bone fractures and segmental bone defect is a challenge for orthopaedic surgeons. The use of autologous bone graft (ABG) is always considered the gold standard treatment. Traditional techniques for harvesting ABG from iliac crest usually involve several complications, particularly at the donor site. The Reamer-Irrigator-Aspirator (RIA) is an intramedullary reaming system that generates a large volume of cancellous bone material in a single-step reaming process; this bone material can be collected and potentially used as an ABG source. Our interest is to compare the complications associated with the standard technique of harvesting from iliac crest with those of the innovative RIA harvesting device.

MATERIALS AND METHODS

A database of 70 patients with long bone non-unions was studied. The patients were divided into two groups according to the surgical harvesting technique used: RIA system ABG (35 patients) and iliac crest ABG (35 patients).

RESULTS

At the 12-month follow-up, pain at the donor site was reported in no patients in the RIA system ABG group and five of 35 patients (14.28%) in the iliac crest ABG group. Local infections at the donor site were found in no patients in the RIA system ABG group compared with five patients (14.28%) in the iliac crest ABG group. There were no fractures in the RIA system ABG group and one case (2.85%) of anterior superior iliac spine (ASIS) dislocation in the iliac crest ABG group. No systemic infections were detected in either group.

DISCUSSION

We analysed the scientific literature on the use of RIA technique to collect ABG for use in patients with anthropic-oligotrophic non-unions, with a focus on the complications associated with this technique.

CONCLUSION

RIA bone graft for the treatment of non-unions and segmental bone defect of long bones seems to be a safe and efficient procedure with low donor site morbidity.

Management of traumatic bone loss in the lower extremity

Segmental bone loss represents a difficult clinical entity for the treating orthopedic surgeon. This article discusses the various treatment modalities available for limb reconstruction, with a focus on the indications, potential complications, and the outcomes of available treatment options.

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.