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Infected femoral nail removal and debridement with Synthes Reamer Irrigator Aspirator (RIA)

    Overview

    Professional Guidelines Included
    Learn the Infected femoral nail removal and debridement with Synthes Reamer Irrigator Aspirator (RIA) surgical technique with step by step instructions on OrthOracle. Our e-learning platform contains high resolution images and a certified CME of the Infected femoral nail removal and debridement with Synthes Reamer Irrigator Aspirator (RIA) surgical procedure.
    Fracture related infection (FRI) has a spectrum of presentations ranging from early and obvious infection after fracture fixation to delayed presentations with infected non-union of fractures. Its incidence is reported as being between 1-30% of fractures and is more common following open injuries. FRI has various potential aspects to its presentation and management, including bone infection, soft tissue injury, fractures in varying states of healing and metalwork with biofilm. There is currently a lack of high quality evidence to guide practice in this area and there have been a number of recent consensus papers and a BOAST guideline in an attempt to define best practice.
    Diagnostic criteria considered to confirm FRI include a sinus, fistula or wound breakdown over bone or implant, purulent discharge or pus found during surgery, phenotypically indistinguishable pathogens from 2 deep samples or histopathological staining for bacteria or fungi. Criteria suggestive of FRI include clinical signs of local inflammation (pain, swelling, redness, temperature), radiological signs (lysis, implant loosening, sequestration, periosteal bone formation), elevated blood markers (WBC, CRP, ESR) or a pathogenic organism grown from a single deep tissue sample.
    RIA is made by Synthes, as the name suggests it simultaneously reams, aspirates and irrigates the intramedullary canal as it is passed.
    It can be used simply to harvest autologous bone graft for reconstruction cases however it also allows simultaneous reaming of infected material with irrigation as the reamer passes and collection of the reamings to remove and sample infected tissues in infected cases. RIA is not routinely used for primary nailing of fractures as there is an advantage to autografting the fracture site with reamings rather than removing them.

    Indications

    INDICATIONS
    When infection presents soon after fracture fixation then deep samples should be taken and as assessment of stability made. If the fracture is stable then antibiotic suppression until fracture union with delayed removal of metalwork is an option. Delayed infections with established bone lysis or necrosis should be managed with debridement and deep tissue sampling followed by removal of all metalwork. Bone loss is managed with eradication of dead space either with antibiotic loaded PMMA cement or bone substitutes loaded with antibiotic (such as cerement G, stimulan or Osteoset T as below). Bone substitutes whilst convenient and able to deliver high local doses of antibiotics do tend to produce persistent wound leakage in the post-operative period which can confuse the clinical picture in patients with concerns regarding ongoing infection. Segmental defects can be managed with acute shortening where possible or bone transport with ring fixators for larger defects. If the fracture remains unstable or there is segmental bone loss then further stabilisation will be required, often with external fixation such as a ring fixator. Soft tissue defects should be managed with local or free flap coverage to bring healthy, vascularised, soft tissues into the defect. Post-operatively patients are started on broad spectrum antibiotics with a switch to targeted antibiotics once sensitivities are known. All patients should be managed via an MDT comprising radiologists, microbiologists, orthopaedic and plastic surgeons.

    SYMPTOMS & EXAMINATION
    FRI may present acutely with signs and symptoms of inflammation in the affected limb, this may be associated with persistent wound discharge or delayed wound healing. More chronic cases often present with an established sinus over the fracture or implant, in these cases there may be an established non-union of the fracture. Assessment of a patient with suspected FRI includes taking a detailed history of the injury including details of any open wounds at the time of injury, onset and duration of symptoms, any systemic symptoms and details of previous operations and antibiotic therapy. It is important to know the patients medical background (eg diabetes, possible immunosuppression), current medications and smoking history.
    IMAGING & INVESTIGATIONS
    Initial investigations will include baseline bloods (FBC, ESR, CRP) and X-rays.
    Imaging should be compared with previous images for signs of progression of bone healing, progressive lysis around the implant, sequestra and periosteal new bone formation. In many cases a diagnosis of infection will be obvious (eg sinus over fracture with frank pus) and further imaging may not be indicated. Adjuvant imaging may include MRI (good for assessing soft tissue collections and oedema in bone but degraded by metal implants, good sensitivity but poor specificity for diagnosis of bone infection), CT (good for assessing bone union, cortical involvement in infection and sequestra) and SPECT-CT (combines technetium bone scan with CT to improve localisation with improved accuracy for diagnosis of infection and particularly useful in the presence of metal implants).
    FRI can be classified according to Willnegger and Roth into early (<2 weeks- virulent organism, immature biofilm), delayed (3-10 weeks, maturing biofilm, possible bone invasion) and late (>10 weeks, mature biofilm, bone necrosis and lysis). Osteomyelitis itself is has been classified by Cierny and Mader into 4 groups, medullary (such as after IM nailing), superficial (such as beneath a plate), localised and diffuse (with segmental involvement). In addition to classifying the anatomy of the infection they also divided the host into 3 groups. Type A hosts have no compromising factors, type B hosts have either systemic or local compromise (or both) and in type C hosts the treatment is worse for the patient than the disease.
    ALTERNATIVE OPERATIVE TREATMENT
    In patients presenting with acute infection before fracture union the options are generally to either suppresss the infection (after debridement and tissue sampling) until fracture union and then remove the metalwork or, if the fracture is unstable, to revise the fixation in either one or two stages. Single stage revision fixation would often involve revising to a ring fixator although the use of antibiotic coated intramedullary nails is also an option. Two stage reconstruction involves temporary stabilisation with external fixation until the infection is controlled and then revising to internal fixation.
    Patients with more chronic infections with or without fracture union generally have 3 options. In patients not fit for revision surgery or who do not want surgery then targeted antibiotics to suppress infective flare-ups may be an option (as guided by the bone infection MDT). In the majority of patients limb salvage surgery is offered, as outlined above this involves debridement of infected soft tissue and bone with deep tissue sampling, management of bone and soft tissue dead space (antibiotic loaded carriers, local or free flap coverage) and stabilisation of the bone if needed followed by a prolonged course of targeted antibiotics. The third option in lower limb infected non-unions is amputation particularly in cases below the knee where prosthetic rehabilitation will give the patient good functional recovery.


    Setup

    For this case we have placed the patient in a lateral position as this makes removal of an antegrade femoral nail easier. We are using a radiolucent table to facilitate access for the image intensifier. A TED stocking and flowtron boot are applied to the contralateral limb.
    The patient will be given broad spectrum antibiotics intra-operatively once deep tissue samples for microbiology have been taken, in our unit we use vancomycin and meropenem. This will continue post-operatively until the microbiology results are back and we can switch to an antiobiotic targeted to the specific organism(s).

    Operation – 1

    This 35 year old man was previously a polytrauma victim following a high speed road traffic collision.
    His injuries included a closed femoral fracture managed with a retrograde femoral nail. He presented approximately 3 months after the index procedure with increasing pain and inability to weight-bear with a broken femoral nail.

    Deep tissue samples at the time of revision surgery were negative. The patient went on to achieve union but developed a sinus with intermittent discharge over one of the distal locking bolts. On the basis of the history the metalwork was presumed to be infected with an intramedullary osteomyelitis. The patient was a type B host, according to the Cierny and Mader classification with a background of smoking and substance abuse.
    In view of his ongoing discharge from the distal wound and persistent infection it was decided to remove the metalwork, debride the intramedullary canal with RIA and then manage the deadspace within the bone with antibiotic loaded bone substitute (Osteoset T).

    Progressive lysis around the implant and loosening of the distal locking bolts (1.) is evident on serial imaging.

    The patient is in a lateral position, bad side up.The whole limb from above the greater trochanter to the foot has been exposed. An Ioban drape has been applied to help prevent the surgical drapes moving during the procedure and potentially contaminating the surgical field.

    The previous incision is opened and extended proximally and distally.It is helpful to mark the incisions on the patient before placing the Ioban drape. The previous nail was an antegrade femoral nail with a trochanteric entry point, the dissection proceeds through the hip abductors (divided in line with the incision) to the nail entry point on the greater trochanter.

    The leg is in a different position to when the nail was inserted was the patient is now in a lateral position.
    Thus the entry point of the nail in the bone does not lie directly beneath the wound and a retractor (1.) is used to expose the greater trochanter.

    To remove the nail a Coremus IM Nail Extraction set (Aquilant Orthopaedics) is used.This is universal nail extraction instrumentation that allows any nail to be removed.
    It consists of a range of extraction bolts with different thread pitch and diameter to match the size of the nail which is to be removed.

    The selected extraction bolt (1.) is loaded onto an extension bar(2.) to make insertion into the nail easier.There are 34 extraction bolts on the set, with varying thread diameters and pitches, designed to fit into the insertion thread of any nail.
    In many cases the type of nail is known and extraction bolt size can be referenced from the product literature.
    In cases where the type of nail is not known a system of trial and error is used to find the correct bolt for the nail.

    The extraction bolt is first threaded into the proximal end of the nail.The extraction bolt and extension are tightened using a spanner.

    The extraction bolt position is checked with the image intensifier to confirm that the bolt is not cross-threaded.It is easier to connect the extraction bolt at this stage, while the nail locking bolts are still in situ, to prevent the nail rotating as the bolt is tightened into position.

    The nail locking bolts can now be removed, first the distal bolts are identified using the image intensifier.

    The incision is extended through the fascia lata to access the distal locking bolts.At this level there are generally only a few fibres of vastus lateralis overlying the bone. Scar tissue over the bolts is removed with an elevator.


    In this case bone had grown over one of the bolts.
    This was removed with a bone nibbler.

    During attempted removal of the most distal bolt it advanced through a defect in the lateral cortex into the bone.
    This was in the area of recurrent infection and drainage and most likely represented an ongoing infection around the locking bolt with consequent osteolysis. This bolt was removed using a forceps as shown.

    The wounds are then closed in layers using monofilament interrupted sutures.

    The proximal locking bolts are again identified with image intensifier & removedThe previous incision is used, extended through the fascia lata and the vastus lateralis divided in line with the incision. This nail had been locked proximally with recon screws into the femoral head and other than perforating branches of the vastus there are no other structures at risk, clearly different locking configurations may present other risks. This is particularly apparent with retrograde femoral nails where the proximal locking bolts are inserted antero-posterior and the femoral neurovascular bundle is medial to the approach- these screws should be removed with an open approach.


    The proximal locking bolts are then removed.

    To remove the nail after locking bolt removal a slap-hammer is used, this is part of the Coremus set.

    The slap-hammer is threaded into the extraction bolt.The nail is carefully removed with controlled blows with the slap-hammer. Images are taken to ensure the nail is not impeded as it is explanted. The commonest reason for difficulty removing the nail is failure to remove all of the locking bolts although at times a sclerotic rim of bone may have formed around the nail which can block the nail tract as it is removed, this is particularly an issue with tibial nails where the Herzog bend in the proximal part of the nail can be impeded if the nail has been in for a long time.

    Following nail removal a reaming rod (Synream, 1.)) is placed into the intramedullary canal.This will be used to guide the RIA during the next stage.

    The rod position is checked with the image intensifier to ensure it is correctly placed in the intramedullary canal.

    To debride the intramedullary canal use the Synthes RIA (Reamer-Irrigator-Aspirator).RIA is made by Synthes, as the name suggests it simultaneously reams, aspirates and irrigates the intramedullary canal as it is passed.
    It can be used simply to harvest autologous bone graft for reconstruction cases however it also allows simultaneous reaming of infected material with irrigation as the reamer passes and collection of the reamings to remove and sample infected tissues in infected cases. RIA is not routinely used for primary nailing of fractures as there is an advantage to autografting the fracture site with reamings rather than removing them.
    The reamer head (1.) is mounted on the reamer rod, the head has holes to allow irrigation and aspiration. The reamer heads come in a variety of sizes, the size is chosen to allow sufficient over-reaming of the canal. In this case I chose a reamer head size 1.5mm larger than the largest reamer used in the previous surgery to ensure that all biofilm and involved bone was removed.

    At the proximal end the reaming rod is attached to a drive-coupler (1.).

    Next the irrigation fluid is connected (1.) to the reamer.Irrigation is with high volume saline. It is vital to check, during reaming, that the fluid is running as this will keep the reamer head cooled.

    Finally the aspirator is attached (1.) to the reamer.This is connected to the theatre suction, the reamings will be collected in the filter (2.).

    Operation – 2

    The RIA is then advanced over the reaming rod.

    Before reaming is commenced the suction and irrigation are checked.Reaming is performed gradually, advancing a few centimetres then withdrawing to allow a controlled progression of the reamer. The reamer head is very sharp and cortical perforations are possible so repeated checks with X-ray are taken to avoid this. Significant blood loss is also possible and attention should be paid to the suction/aspiration.

    The reamer is advanced all the way to the distal femur to derbride the entire footprint of the nail.As well as taking care to avoid cortical perforation as the RIA is advanced we also screen with image intensifier to ensure that the knee is not inadvertently entered with potential seeding of infection into the joint.

    The reamings, a mixture of biofilm and bone, are collected in the aspirator filter.

    Samples are taken from the reamings.A minimum of 5 deep tissue samples are taken for microbiology. Each sample is taken with a clean set of instruments (1.) and put into separate specimen pots (2.). We will know, therefore, that if 2 or more of these samples grow the same organism that this is likely to be a representative organism rather than a contaminant. Further samples are taken for histopathology.
    Once samples are taken the anaethetist gives broad spectrum antibiotics, our local policy is for vancomycin and meropenem.

    After debridment of the femoral canal the screw holes are debrided.This can be performed by over-drilling with a drill bit of larger diameter than the removed screws. In this case a curette is used to debride the distal locking bolt tract.

    After debridement is completed further lavage is performed with saline.A large bore giving set (urology irrigation set) is used with 6 litres of saline.

    Following debridement the deadspace within the bone is addressed.
    Filling of the deadspace reduces haematoma formation and the risk of recurrent infection. A variety of techniques can be used including use of antibiotic loaded cement nails- this would however necessitate a return to theatre to remove the nail and therefore in this case the deadspace is filled with Osteoset T (Wright medical). This consists of calcium sulphate pellets loaded with Tobramycin which will elute antibiotics into the deadspace with peak concentrations on day one but continued elution of bactericidal levels for approximately 3 weeks. The pellets themselves are resorped by osteoclasts over a period of several months.

    The deadspace is filled with Osteoset T (Wright medical) pellets, placed initially in the distal femur.Filling of the deadspace reduces haematoma formation and the risk of recurrent infection.As much of the canal is filled as is practical, this will reduce the volume of haematoma that forms and the haematoma that does form will contain a high dose of antibiotic reducing the risk of recurrent infection.

    Here the pellets can be seen in the void from the distal locking bolt.

    Pellets are then placed in the proximal femur.

    To advance the pellets down the femoral shaft a pusher is used.This is made from an Ilizarov threaded rod.

    The threaded rod is advanced in the femur using a universal chuck T-handle. This allows the Osteoset pellets to be advanced down the femoral canal.

    The femur is screened with the image intensifier to ensure pellets are distributed along the length of the femur.

    Skin is closed with interrupted nylon sutures

    Post-operative xray showing osteoset T pellets along the length of the femur.

    Post Operative

    Broad spectrum antibiotics are continued until microbiology results and sensitivities are available (often 5-7 days) at which point the antibiotics are targetted to the relevant organism. In this case a sensitive staphylococcus aureus was grown from all 5 microbiology samples and histology showed a mixed acute and chronic inflammatory picture in keeping with infection. The patient was therefore discharged on a prolonged course of ciprofloxacin and rifampicin- polytherapy using antibiotics with good tissue penetration is preferred. In most cases a total of 6 weeks of antibiotics are given although in cases with atypical organsims a longer duration of antibiotic treatment maybe indicated.
    In this case the fracture had healed and full weight bearing was permitted, enoxaparin was given for 7 days.
    Initially patients are reviewed every few weeks to ensure the soft tissues heal as anticipated and there are no early signs of recurrent infection. In our unit following treatment of bone infection patients are reviewed regularly for 2 years to monitor, clinically and radiologically, for signs of recurrence. In cases of bone infection with non-union or bone loss regular follow up to monitor healing or manage bone defects in ring fixators is required. Patients in ring fixators are followed up in an MDT clinic involving specialist physiotherapists and nurses as well as the surgical team.

    Recommended Reading

    George Cierny 3rd, Jon T Mader, Johan J Penninck. A Clinical Staging System for Adult Osteomyelitis Clin Orthop Relat Res 2003 Sep;(414):7-24. doi: 10.1097/01.blo.0000088564.81746.62.
    Classic paper describing the anatomy of osteomyelitis and the host factors to consider it the management of bone infection. The surgical and medical management of each stage is discussed in detail.

    George Cierny 3rd, Jon T Mader, Johan J Penninck. A Clinical Staging System for Adult Osteomyelitis Clin Orthop Relat Res 2003 Sep;(414):7-24. doi: 10.1097/01.blo.0000088564.81746.62.
    Classic paper describing the anatomy of osteomyelitis and the host factors to consider it the management of bone infection. The surgical and medical management of each stage is discussed in detail.

    Metsemakers WJ, Morgenstern M2, McNally MA, Moriarty TF, McFadyen I, Scarborough M, Athanasou NA, Ochsner PE, Kuehl R, Raschke M, Borens O1, Xie Z, Velkes S, Hungerer S, Kates SL, Zalavras C, Giannoudis PV, Richards RG, Verhofstad MHJ Fracture-related infection: A consensus on definition from an international expert group. Injury. 2018 Mar;49(3):505-510. doi: 10.1016/j.injury.2017.08.040. Epub 2017 Aug 24.
    A consensus paper from a group of international experts that outlines criteria for confirmed and suspected infection after fracture fixation based on the clinical presentation, blood parameters, microbiology and histopathology.

    Metsemakers WJ, Morgenstern M, Senneville E, Borens O, Govaert GAM, Onsea J, Depypere M, Richards RG, Trampuz A, Verhofstad MHJ, Kates SL, Raschke M, McNally MA, Obremskey WT; Fracture-Related Infection (FRI) group. General treatment principles for fracture-related infection: recommendations from an international expert group. Arch Orthop Trauma Surg. 2019 Oct 29. doi: 10.1007/s00402-019-03287-4.
    Another consensus paper dealing with the treatment of fracture related infection including such aspects as host optimisation, MDT working, bone sampling, bone debridement and the management of soft tissue and bone defects.

    OVIVA Trial Collaborators Oral Versus Intravenous Antibiotics for Bone and Joint Infection N Engl J Med 2019 Jan 31;380(5):425-436. doi: 10.1056/NEJMoa1710926.
    Multi centre RCT comparing prolonged intravenous antibiotics versus a switch to oral antibiotics at 7 days. The primary outcome was treatment failure at one year (ie recurrent infection). Overall this occurred in 14.6% in the intravenous group and 13.2% in the oral antibiotic group thus showing non-inferiority of an early switch to oral antibiotics. This supports a move away from prolonged intravenous therapy, the issue of local versus systemic antibiotics remains unresolved for now.


    OVIVA Trial Collaborators Oral Versus Intravenous Antibiotics for Bone and Joint Infection N Engl J Med 2019 Jan 31;380(5):425-436. doi: 10.1056/NEJMoa1710926.
    Multi centre RCT comparing prolonged intravenous antibiotics versus a switch to oral antibiotics at 7 days. The primary outcome was treatment failure at one year (ie recurrent infection). Overall this occurred in 14.6% in the intravenous group and 13.2% in the oral antibiotic group thus showing non-inferiority of an early switch to oral antibiotics. This supports a move away from prolonged intravenous therapy, the issue of local versus systemic antibiotics remains unresolved for now.



    Reference

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