One stage exchange arthroplasty: the devil is in the detail The general management of periprosthetic infections after total approach in the revision of an infected TJR. Emphasis is given joint replacement (TJR) remains a challenging procedure to to all detailed requirements that provide the basis for a high any arthroplasty surgeon. The infection rate after primary TJR surgical and post-operative success rate. is reported to be between 0.5% and 2%, however in the field of revision arthroplasty, this might increase to over 10%.1-4 Etiology and Classification Consequently, periprosthetic infections remain a serious Every periprosthetic infection is a foreign body associated problem, despite modern techniques, implants and rigorous infection and should be clearly differentiated from other bone perioperative prophylaxis. The therapeutic goal in either one or more staged revisions of periprosthetic infections is, in Most micro-organisms from human bacterial flora gain general, defined by a complete eradication of the infection and access to the surface of the prosthesis during the operation maintenance of the joint function. and more than 90% of infections during the first year after While it has been widely accepted that the treatment of a late operation are due to contamination during the procedure.21 chronic infection should be undertaken with a two- or more- Haematogenous infections are less frequent. In the presence of staged revision technique, a distinct single-staged revision foreign bodies, a contamination as low as 100 colony-forming approach has shown similar good results within the last 30 units (CFU) is sufficient to induce an infection. In comparison, years in our own clinical setup.5-8 when no foreign material is present, it takes 10 000 cfu.22 This In general, both revision techniques should be available effect is due to the diminished clearing capacity of phagocytosis depending on the clinical situation, the local setup and the by leucocytes in the presence of foreign material.23,24 surgeon expertise. In the most frequent scenario, implant Furthermore, the bacteria are adhesive to the implant removal is followed by a defined six week or longer course of surface by forming a biofilm. This biofilm blocks natural defense systemic antibiotic treatment and delayed implantation. mechanisms. These sessile bacteria are also highly resistant to In particular, the introduction of antibiotic impregnated spacers antimicrobial agents and the minimal inhibitory concentration in infected total knee and hip revisions, seemed to improve the can be elevated up to the 1000-fold within the biofilm.25 functional outcome of the two-staged approach and has gained The general period between colonisation and clinically increasing popularity within the last five to ten years.9-11 detectable infection may last for months or years and as However, looking carefully at the current literature and a result, local signs of infection may occur very late. It is guidelines for the treatment of infected TJRs, there is no clear important to realise that periprosthetic infection does not only evidence that a two- or more-staged procedure has a higher indicate an infection of the prosthetic interface, but also of the success rate than a one-staged approach.(Della Valle)12 surrounding bone and soft tissues.
Although a larger number of relevant articles4,10,13-15, describe the two-staged technique as the benchmark procedure for the eradication of infection, most of the recommendations Infection can be classified in two ways; 1) acute infection - (duration of antibiotic treatment, static vs mobile spacer, occurring within the first three post-operative weeks; 2) late interval of spacer retention, cemented vs uncemented new infection - occurring after the third post-operative week.
implant fixation and especially overall success rates) are based Consequently we aggressively treat an acute infected TJR on expert opinions and evidence level IV to III studies, rather with a local debridement, soft-tissue revision and lavage, than on prospective, randomised or comparative data.4,10,11,13-18 polyethylene liner exchange, including preservation of the We consequently believe that a distinct one-stage exchange initially implanted prosthesis. Systemic antibiotics are adapted still offers certain advantages with a comparatively high to the algorithm described by Zimmerli, Trampuz and Ochsner.26 success rate. The major advantages are the need for only Late infection, however, is treated with complete implant one procedure (if no recurrence), reduced hospitalisation removal. Independent from a one- or two-staged approach, time, reduced overall cost and relatively improved patient a further re-implantation of a new prosthesis should be scheduled as soon as possible after infection eradication. Although obvious advantages exist, there are obligatory Earlier classification guidelines mostly defined stages of pre- and peri-operative details which need to be meticulously periprosthetic joint infection (PJI) into early, acute and late respected to achieve a successful one-staged revision. infection types. Due to the general advancements of diagnostic Consequently this article describes the author's experience algorithms and further developments of systemic and local of their current institution's management strategies, which treatment options, we also adapted our classifications system have been in place for over 30 years, with the one-staged to the staging system described by McPherson et al.27,28 This 2012 British Editorial Society of Bone and Joint Surgery D. KENDOFF, T. GEHRKE includes, besides type and timing of infection, mainly the current systematic medical and immune status of the host Serial conventional radiological comparison can be useful to patient, as well as the current local extremity grade based on all detect obvious osseous infections signs. For the diagnosis possible local compromising factors. of PJI however, we do not tend to use nuclear imaging in our setup. Although highly sensitive, bone scans, as labeled leukocyte imaging, Gallium imaging or PET imaging have The first symptoms of early infection usually present around shown to be non-specific with consequently only moderate four to eight days after a TJR. With the presence of purulent reliable study data.12 Bone scans have been shown to visualise secretion, infection is clear. However, any prolonged wound suspicious enhancements for several years following TKR and discharge (> 12 days), continued soft-tissue swelling and THR. Enhancements occur especially after the early phase of induration, or wound dehiscence should be taken seriously. implantation, therefore can represent bone remodeling and We suggest in these cases that a pro-active and aggressive may be misleading.
approach is taken at all times by the surgeon. If an early In addition to conventional radiological imaging of the infection (within three weeks) occurs after the patient is affected joint, we recommend clinical and radiological discharged from the hospital, often superficial wound healing evaluation of all other joint replacements of each PJI patient, problems, hematomas and seromas are evident, which might e.g. contralateral affected THR. correlate with the presence of deep infection of the implant. This however, is not always obvious and the clinical signs can In general we see very few arguments against a one-staged According to our experience, current evidence and recent revision protocol, and are able to successfully treat over 85% clinical practice guidelines by the American Academy of of all infected cases using this technique. The mandatory Orthopaedic Surgeons, we defined the following mandatory infrastructural requirement is based on the evidence of the pre-operative testing, for every case of a TJR patient with bacteria in combination with a distinct patient specific plan for unexplained pain.12 the topic and systemic antibiotic treatment by an experienced • Laboratory monitoring of CRP and erythrocyte sedimentation rate (ESR).29,30 • Knee and hip joint aspiration with prolonged microbiologic culture time of at least 14 days, with patients being off We defined the following criteria to alter our one-staged antibiotics for a minimum of 14 days.31 approach to a two-staged procedure: • Synovial fluid analysing of white blood cell count and • Failure of ≥ two previous one-staged procedures percentage of neutrophils.32-34 • Infection spreading to the nerve-vessel bundle • Repeated aspiration in cases of own negative cultural • Unclear pre-operative bacteria specification results in combination with either obvious infection signs • Non-availability of appropriate antibiotics or pre-existing external positive cultural results.
• High antibiotic resistance • Biopsy of the knee joint in cases of persistent negative aspiration results, with obvious infections signs.35 Pre-operative preparation and planning To undertake a one-stage procedure a positive bacterial culture must be present and a respective antibiogramm must exist. The mandatory and most relevant pre-operative diagnostic The proposed cemented fixation using antibiotic loaded acrylic test needed in any case of a planned one-staged exchange, cement is considered to be the treatment of choice in order is based on knee joint aspiration with an exact identification to achieve a high topic therapeutic level of antibiotic elution of the bacteria. The presence of a positive bacterial culture from the cement.36,40 In the future, antibiotic local implant or and respective antibiogramm is needed for the one-staged silver coatings might be viable alternatives for the one-staged procedure in order to define which antibiotic loaded acrylic cement is required to achieve a high topic therapeutic level of The success of a one-staged approach not only depends antibiotic elution.13,14,36-40 on the meticulous removal of all hardware material (including This protocol has become mandatory in our clinic for cement and restrictors) in combination with the antibiotic every planned TJR revision including all late or early aseptic loaded acrylic cement, but also an aggressive and complete loosening, furthermore in all other cases of unexplained pain or debridement of any infected soft-tissues and bone material malfunction after primary or revision TJR. (Fig. 1). For example, this should include a full synovectomy in In a previous aspiration study, we were able to show that the posterior aspects of the knee or radical debridement of the between 4% and 7% of our patients who were initially planned anterior and posterior capsule of the hip (Figs. 2 and 3). to have an aseptic total hip or knee replacement revision had In the knee this approach might also include sacrificing the evidence of a subtle low grade infection, without any obvious collateral ligaments to perform a complete and radical soft- clinical symptoms or relevant laboratory elevations as described tissue resection. Thus the definitive pre-operative planning should consider the use of a of a semiconstrained or even full THE JOURNAL OF BONE AND JOINT SURGERY

ONE STAGE EXCHANGE ARTHROPLASTY contrained implant, also based on the surgeons preference and General Pre-Operative Planning • There should be clinical and anaesthesiological assessment of the general operative risk • An adequate supply of available donor blood • In the case of long exchange operations, pre-operative administration of fibrinolysis inhibitors (e.g. tranexamic acid) is recommended Specific risks to patients • The risk of recurrent or new infection between 10% and Fig. 1. Meticulous debridement of all affected soft tissues in a one-staged revision total knee replacement.
• A risk of reoperation for haematoma, wound debridement or persistent infection • Damage to the sciatic / peroneal nerve • Post-operative stiffness and loss of function (extensor • Intra- and post-operative fracture • Increased risk of aseptic loosening Surgical Preparation Implants and Cement: • The surgeon should have experience of the type of implant to be revised and be familiar with its removal and disassembly. Occasionally the use of implant-specific instrumentation will be necessary • Pre-existing ligament deficiencies in the knee require constraint implants; however ligament deficiency may also result during intra-operative debridement – hence the Fig. 2. Aggressive debridement also includes the posterior knee aspects.
need for rotating or fixed hinged implants in general. Based on our aggressive soft-tissue debridement, this is the case in over 90% of our one-staged knee revision cases • Inadequate bone stock, possible intra-operative complications as acetabular / femoral or tibial shaft fractures, perforations of the cortex, osseous windows and tibial/femoral disintegration must be taken into consideration when choosing an appropriate implant. • Distal femoral or proximal tibial replacement implants may have to be chosen in patients with significant bone deficiency in the knee. Bone loss is usually significantly more extensive than radiologically evident. Custom-made implants with extra-long or narrow stems may have to be ordered prior to surgery. The need for total femoral replacement implants is rare. • Significant damage to the extensor mechanism of the knee can require an arthrodesis nail, which should be available as a last option in necessary cases (with patient consent) • Antibiotic loaded acrylic cement with additional antibiotics in powder form to be added intra-operatively is obligatory in all cases. Invariably at least two or three mixes of cement (between 80 g and 120 g) are required. Large mixing systems and appropriate cement guns are required. In patients with a narrow diaphysis extra narrow nozzles allow for appropriate retrograde cementing technique.
Fig. 3. Aggressive debridement of the hip includes the ventral capsule and • Knowledge about possible type of antibiotic loaded acrylic even very caudal aspects of the an affected hip joint.
cement used at primary implantation, as resistance to the D. KENDOFF, T. GEHRKE previously used antibiotics must be expected. must be as radical as possible (Fig. 1). It must include all • Often industrially pre-manufactured antibiotic loaded areas of osteolysis and non-viable bone. acrylic cement may be appropriate. However, for the • Completing the debridement often exceeds the amount success of any one-staged procedure, the antibiogramm of resected material than seen in a two-staged approach for the final topic cement impregnation is mandatory. • We recommend the general use of pulsatile lavage Operative Technique throughout the procedure, however after all implant Skin Incision and debridement: removal and completed debridement, the intramedullary • Old scars in the line of the skin incision should be excised. canals are packed with polymeric biguanid-hydrochlorid The prior incision from the last operative approach should (polyhexanid) soaked swabs. Furthermore the swabs are be used, if possible. In cases of multiple scars, the most placed over the wound area before re-draping the patient. lateral one should be considered. • The whole team should re-scrub and new instruments be • Fistulae should be integrated into the skin incision and obtained for re-implantation. radically excised to the joint capsule. If the need for • A second dose of antibiotics should be given after 1.5 muscular-cutaneous flaps can be anticipated, a plastic hours operating time or if blood loss at this point exceeds surgeon should be available. • An anticipated operative time exceeding two hours should include an above knee tourniquet, but not inflated. The knee procedure should be started without tourniquet; • Inadequate bone stock may require the use of allografts, consequently interfaces between infected tissue, scar although ideally this should be avoided. We even prefer to and surrounding healthy bleeding soft tissue can be fill large defects with antibiotic loaded acrylic cement, and distinguished more clearly during the debridement. All do not favour the use of any allograft.
non-bleeding tissues and related bone need to be excised • Alternatively the use of tantalum based acetabular very aggressively. After debridement and implant removal, wedges, femoral and tibial cones have been implemented maintaining the tourniquet can be helpful for the removal in our regular clinical use for over four years. Variations of intramedullary and the re-cementation. of depth and width of those augments allow for a proper • Biopsy material, preferably five or six samples, should reconstruction of the resulting bone loss, including an be taken as a routine measure from all relevant areas excellent biocompatibility and related stiffness and cellular of the operation site for combined microbiological and structure. Consequently a combined fixation of the cement histological evaluation,21,35,41 after the defined antibiotics with the prosthesis and tantalum augment becomes have been administered. This commonly comprises a wide possible. It has been postulated that tantalum has some spectrum cephalosporin with further antibiotic related antibacterial potential; however this has not been clinically • The antibiotic loaded cement is prepared in the meantime, Implant removal and completion of debridement fulfilling the following criteria: • Removing cemented implants can be easier and less - Appropriate antibiotic (antibiogramm, adequate elusion invasive than removing ingrown cementless components.
characteristics) • In cases of well-fixed uncemented components, cortical - Bactericidal (exception Clindamycin) windows are required to gain access to the interface. - Powder form (never liquid) High speed burrs and curved saw blades can aid removal, - Maximum concentration of 10%/PMMA powder however, occasionally significant destruction and related • Antibiotics (e.g. Vancomycin) might change the loss of bone stock can occur. polymerisation behaviour of the cement, causing • Narrow, straight osteotomes with symmetrically coned acceleration of cement curing. blades should be used to remove all accessible bone • Current principles of modern cementing techniques should cement, being careful not to cause further loss of bone. be applied (Fig. 4). In order to achieve an improved cement • A multiple osteotome technique should be used in the bone interface, the tourniquet should be inflated prior to knee to drive cement from between the tibial base plate cementing in TKR cases. and medial and lateral component. This may be less destructive than aggressive extraction with the mallet. • Extraction of the implant necessitates special or universal Associated post-operative systemic antibiotic administration extraction instruments, if available. Otherwise general is followed for 10 to 14 days (exception: streptococci). While punches are required. a prolonged administration of intravenous antibiotics for six • Special curved chisels, long rongeurs, curetting weeks is common in the two-staged approach, the rational instruments, long drills and cement taps are used to for this prolonged period of time has not been clarified in the remove the cement. In the hip joint, retrograde chisels can literature. There is, however, clear evidence of relevant systemic be helpful in many cases. and organ-specific complications after prolonged antibiotic • General debridement of bone and posterior soft-tissues THE JOURNAL OF BONE AND JOINT SURGERY

ONE STAGE EXCHANGE ARTHROPLASTY staged exchange. The general risk of intra- and post-operative fractures should be comparable to the two-staged exchange. The two-staged approach has become the method of choice for most surgeons worldwide, with reported re-infection in between 9% and 20% of cases.15,18,42 Although advocated as the benchmark procedure, we have established and followed the one-staged approach in our clinic for over 35 years and in over 85% of all our infected TJR patients.
Accordingly, far more studies have been published and emphasised about the two- or more-stage revision technique.1-14,16,18,23,28,27,35 Few studies evaluating the one stage exchange and its techniques are available.5,8,19,20,43-46 Although most reports are from our own institution, some Fig. 4. Aggressive debridement of the hip includes the ventral capsule and international experience using this technique exists with rates even very caudal aspects of the an affected hip joint.
of success between 75% and 90% depending on the time of Besides the obvious benefit by eliminating a second major Post-operative care and rehabilitation operation, further major advantage arise from the reduced Post-operative stay in hospital ranges between 12 and 20 days duration of post-operative systemic antibiotics. This rarely (mean, 14) in our setup. The physiotherapeutic approach in any prolongs more than 14 days in our setup. The rational for one-staged approach cannot be generalised. Due to the variety this has also been evaluated in a study by Hoad-Reddick et of soft-tissue and bone damage, and the extent of infection, al,16 where the authors concluded that a prolonged course of an individual plan is developed in most cases. Compromises antibiotics does not seem to alter the incidence of recurrent or between necessary immobilisation due to structural damage persistent infection, even after a two-staged revision.
and attempts for an early mobilisation, especially in an elderly multimorbid patient, have to be made. However, we recommend Summary an early and aggressive mobilisation within the first eight days The one-staged infected TJR approach is used sparingly in post-operatively. Weight-bearing should then be adapted to the the orthopaedic community. From our perspective the one- intra-operative findings and substance defects. In TKR patients, stage revision offers certain obvious advantages. The key to a similar mobilisation strategy compared to the primary success is based on the well-defined and detailed intra-hospital situation allows the patients to fulfil an early rehabilitation infrastructure, including a meticulous pre-operative aspiration process, which should reduce associated muscular movement regime, planning, aggressive intraoperative surgical approach restrictions, stiffness or fibrosis of the affected knee.
and post-operative specific patient care In patients with adequate bone stock and relatively low soft-tissue involvement, an immediate full-weight-bearing mobilisation often becomes possible. D. Kendoff MD, PhD Persistent or recurrent infection remains the most relevant Orthopaedic Surgery complication in the one-staged technique. As failure rates with ENDO-Klinik Hamburg a two-staged exchange have been described as being between 9% and 20% in non-resistant bacteria, our experience shows comparative results after eight years of follow-up using the one-staged approach (unpublished data).12,15,17,42 As a result, we E-mail: [email protected] discuss with patients, at the time of consent, a possible risk of recurrent or new infection in between about 10% and 20% of Although we are unable to present comparative data 1. Bozic KJ, Kurtz SM, Lau E, et al. The epidemiology of revision total knee
evaluating the functional outcome under a one- versus two- arthroplasty in the United States. Clin Orthop Relat Res 2010;468:45-51.
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or a partial or complete immobilisation of the affected joint, will and surgeon resource utilization. J Bone Joint Surg [Am] 2005;87-A:1746-51.
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the United States. J Arthroplasty. 2008;23:984-91.
We consider the risk of direct damage to the sciatic or 4. Kurtz SM, Ong KL, Lau E, Bozic KJ, Berry D, Parvizi J. Prosthetic joint infection
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34. Trampuz A, Hanssen AD, Osmon DR, et al. Synovial fluid leukocyte count and
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Policy Brief • April 2016 GPE's Work in Conflict-affected and Fragile Countries Accelerated Support in Emergency and Early Recovery Situa-tions, GPE has successfully promoted coordinated deci-sions about the best way to utilize resources in crisis settings, such as shifting them to non- governmental 28 GPE's developing country partners are classified providers for direct service provision during acute

Helping smokers quit — opportunities created by the affordable care act

The NEW ENGL A ND JOUR NA L of MEDICI NE Helping Smokers Quit — Opportunities Created by the Affordable Care ActTim McAfee, M.D., M.P.H., Stephen Babb, M.P.H., Simon McNabb, B.A., and Michael C. Fiore, M.D., M.P.H., M.B.A. In its review of tobacco-dependence treatments, thereby increase rates of cessa- the 2008 clinical practice guideline of the U.S.