Combined Surgical And Medical Treatment For Periprosthetic Femoral Fractures Over A Stable Stem (Vancouver Type B1 And C): A Proposal Of A Therapeutic Algorithm To Reduce The Risk Of Nonunion.

Combined Surgical And Medical Treatment For Periprosthetic Femoral Fractures Over A Stable Stem (Vancouver Type B1 And C): A Proposal Of A Therapeutic Algorithm To Reduce The Risk Of Nonunion. | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Combined Surgical And Medical Treatment For Periprosthetic Femoral Fractures Over A Stable Stem (Vancouver Type B1 And C): A Proposal Of A Therapeutic Algorithm To Reduce The Risk Of Nonunion. Nicola Mondanelli, Giovanni Battista Colasanti, Carlo Cataldi, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-38837/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background : There is lack of consensus regarding best operative fixation strategy for periprosthetic femoral fractures (PFFs) around a stable stem. Based on our experience in the treatment of nonunions after PFFs and other challenging cases and on Literature, we propose an algorithm that can guide in choosing the ideal surgical technique even for first-time PFFs with a stable stem. Methods : We retrospectively reviewed data on patients who failed to heal after a surgically treated Vancouver type B1 or C PFF. All patients were treated with locking plate, double structural allograft and autologous bone marrow concentrate (BMC) over a platelet-rich plasma (PRP)-based membrane at fracture site. All patients were also pharmacologically treated with Teriparatide in the postoperative period. We studied patients with radiograms, histological evaluation of the nonunion area, and phosphocalcic metabolism. Patients were assessed subjectively, clinically and radiographically until healing and then annually. Results : All nonunions healed over a six months period, and functional recovery appeared to be good. Retrospective evaluation of the proposed algorithm showed that none of the patients met biological or mechanical criteria such as to make valid the treatment with locking plate alone. Conclusion : Mechanical factors are not the only issues that should be taken into account when choosing the surgical approach to PFFs over a stable stem. Systemic and local biological conditions are factors that should drive to a rigid fixation with absolute stability (using a plate and structural allograft) plus local biological support (structural allograft and autologous BMC in a PRP-based scaffold) and systemic anabolic treatment (Teriparatide) in the first instance. A therapeutic algorithm is proposed, given the prosthetic stem to be stable, taking into account mechanical and biological criteria. Orthopedics periprosthetic femoral fracture Vancouver B1 Vancouver C therapeutic algorithm Teriparatide re-fracture nonunion non-union bone marrow concentrate stable stem structural allograft Figures Figure 1 Figure 2 Figure 3 Figure 4 Background The incidence of periprosthetic femoral fractures (PFFs) is reported to be between 1% and 11% over a primary hip femoral stem and up to 18% over a revised hip femoral stem [ 1 – 5 ]. Their treatment is based on level of fracture, implant stability and quality of bone stock, and the comorbidity of the patient [ 2 , 6 – 9 ]. The Vancouver classification developed by Duncan and Masri [ 10 ] is the most widely used for guiding the surgeon in pre-operative planning [ 7 , 11 – 13 ], and it has been developed into the Unified Classification System for Periprosthetic Fractures [ 14 , 15 ]. New patterns of fracture has also been described for PFF around a hip femoral stem, with different prevalence over uncemented or cemented stem and apparently over stem geometry [ 16 – 21 ]. Modified Vancouver classification and correspondent proposed treatment from Literature are shown in Tables 1 and 2, respectively. Anyway, there is no clear consensus on the optimal method of treatment for fractures around a stable femoral stem hip implant [ 22 – 24 ]. Type B1 fractures represent 30% and type C fractures represent 10% of all PFFs, and their treatment can be associated to a higher risk of complication than other PFFs types and high risk of failure due to nonunion with implant loosening and/or re-fracture [ 8 , 25 – 31 ]. Clearly, this entails an important economic expense [ 32 – 34 ] and a high rate of morbidity and disability for these patients; moreover, mortality after PFFs and their treatment varies with patient age and concomitant disease between 4.5% and 22% [ 29 , 35 – 39 ]. To date, most of the studies have produced therapeutic algorithms that focus on implant stability, leaving the choice of treatment to the habit of the surgeon, not defining the best surgical strategy; both minimally invasive plate osteosynthesis (MIPO) obtaining an elastic fixation or open reduction and internal fixation (ORIF) with plate and cerclage with or without a structural allograft (or a second plate) have been advocated, based on mechanical issues [ 7 , 25 , 26 , 28 , 40 – 45 ]. Anyway, the biological aspect of the patient has been neglected, considering it as not fundamental for the type of PFF and the surgical approach. Instead, patients with prostheses can present biological systemic and local issues that commonly include multiple medical comorbidities and long lasting medical therapies, and difficulties with postoperative rehabilitation [ 46 ]. Also, the PFF can happen over a bone of very poor quality and/or present a pattern such that mechanical issues are not the only local factors to consider to be deficient. Moreover, studies are present in the literature suggesting that Teriparatide can be usefull in fractures’ and nonunions’ management as well as for osteoporosis [47–52]. This drug works by stimulating osteoblasts and reducing osteoblast apoptosis, increasing callus formation, improving mechanical strength, and resulting in increased osteoblast life span. To date, Teriparatide is often prescribed to promote bone healing, especially in femoral shaft fractures occurred in patients treated with bisphosphonates (BPs) for a long period. The aim of this paper is to propose an algorithm of treatment of PFFs over a stable stem (Vancouver B1 and C types), taking into account both mechanical and biological (local and systemic) criteria that can guide the surgeon in choosing the ideal approach, based on results in the Literature and starting from our own results in the treatment of re-fractures / nonunions on PFFs and other challenging cases as atypical femoral fractures (AFFs) over deformed bones or re-fractures over an implant. Methods We retrospectively reviewed data of patients who failed to heal after fixation for a PFF, classified as Vancouver type B1 or C, whose re-fractures / nonunions we successfully treated with a combined surgical and medical approach with femoral stem retention. We surgically aimed to a rigid fixation (absolute stability) plus biological (osteoconductive, osteoinductive and osteogenic) support. All patients were treated using a low contact lateral plate with polyaxial angular stability screws and cerclages (NCB system, ZimmerBiomet, Warsaw, IN, USA) or a compression plate with screws and cerclages (Cable-Ready Extended GTR Plate, ZimmerBiomet, Warsaw, IN, USA), a double cortical structural fresh frozen allograft (medially and anteriorly placed, at 90° each other; mechanical and osteoconductive support) and local apposition of autologous bone marrow cells concentrate (BMC) embedded in an autologous platelet-rich plasma (PRP)-based membrane (Regenkit BMC and Regenkit Extracell Membrane glue, RegenLab, Le Mont-sur-Lousanne, CH) at fracture site (osteoinductive and osteogenic support). All patients were also pharmacologically treated with Teriparatide (Forsteo, Eli Lilly and Company, Indianapolis, IN, USA) in the postoperative period for at least three months. Teriparatide was prescribed off label after adequate informed consent was acquired and under guidance of the Bone Metabolic Unit. Outpatient follow-up was performed at 1, 3, 6, 9 and 12 months after surgery and then annually, including subjective and clinical evaluation with Harris hip score (HHS) [53] and radiographical evaluation. We studied all radiographs of the patients: pre-operative and post-operative radiographs relative to the first fixation surgery were analysed for potential bone defects, unadvised stem loosening and possible surgical technical errors, and actual radiographs after the re-fracture and in subsequent follow-up visits for fracture healing. All patients were studied for phosphocalcic metabolism before surgery (Table 3), and patient’s history was analysed for biological impairment that could be initially unadvised. In some patients, also, a histological study of the nonunion area was performed. Based on these findings, we set up a list of biological local and systemic criteria to be taken into consideration as risk factors for nonunion together with mechanical criteria. All cases were reviewed and evaluated regarding these proposed criteria. At our Institutions, no Institutional Review Board nor Ethical Committee Approval is necessary for retrospective studies, and patients gave their consent to data collection and anonymous use of them for scientific and teaching purposes. Results We present, as example, the cases of the three patients operated on of revision of osteosynthesis with retention of the stem for nonunion over a PFFs with a stable stem. We analysed the reason why, in our opinion, the PFF did not heal and looked for associated biological factors that could justify an increased risk. In the first patient, a 80-years-old female, (Fig. 1 ) the PFF was at the tip of an uncemented tapered fluted long revision stem (Vancouver type B1) positioned five years before (second stem revision on a dysplastic hip); she had being on BPs for seven years. Breakage of the plate occurred at 15 months from first osteosynthesis, with revision surgery already scheduled for nonunion. She had no impairment of phosphocalcic metabolism, but it appeared evident that technical errors had been made, the medial cortex comminution not being addressed and, as for the fixation, only cables were used by necessity in the proximal fragment: the femur was very small and completely filled with the stem. Histology showed fibrocartilaginous tissue with some bony islands with osteoclasts and fibroblastic cells, with very rare osteoblasts. At re-fracture surgery, proximal fixation was still with only cables by necessity, but the whole femur was spanned, and rigid fixation was achieved with compression of the structural allograft to the host diaphysis. Bone healing was well evident at three months post-operatively, and it appeared complete at six months. The second patient was a 77-years-old female (Fig. 2 ) who experienced a type C PFF over an uncemented double-wedge stem positioned 12 years before for a fragility fracture of the femoral neck; since then, she had been on BPs therapy. She presented hypovitaminosis D, and at surgery histological findings of giant osteoblasts consistent with an AFF were found. No gross surgical errors were evident but the medially placed structural allograft fractured during fixation, so medial buttress was lost. Also, in the first post-operative period, patient did not assume the prescribed therapy with Teriparatide. At re-fracture surgery, three months after, a hooked plate with only proximal cerclages was used; again, absolute stability was guarantee by compression of the plate and the structural allograft to the host diaphysis. Radiographic bone healing occurred at six months post-operatively. The third patient (Fig. 3 ) was a 76-years-old female on chronic corticosteroid (CCS) therapy for myasthenia gravis and presented hypoparathyroidism secondary to a thymoma; she experienced a PFF clear of an uncemented tapered rectangular stem positioned ten years before for hip osteoarthritis; ORIF with morselized bone graft impacted into the medullary canal was performed; fixation was adequate but possibly too much dissection was carried on to access the fracture, resulting in possibly excessive devascularization. Plate breakage occurred at four months from initial surgery; at re-fixation, histology showed nonunion with almost total absence of osteoblasts. A long plate was used, also to bridge the stem with a proximal cerclage to avoid a stress riser between the tip of the stem and a shorter osteosynthesis. All patients underwent complete clinical and radiographic healing over a six months period, and functional recovery appears to be satisfactory with progressive increase in HHS records. All patients presented more mechanical and biological criteria as risk factors for nonunion, and based on the therapeutic algorithm, they should have been operated on for the first-time PFF with the multimodal combined surgical and medical approach we propose. Discussion The main limitations of this study are the small group of patients we analysed and the absence of a control group. Anyway, we focused on a particular group of patients presenting re-fracture / nonunion of a PFF that were treated with repeated osteosynthesis and stem retention: revision arthroplasty for failed osteosyntheses can guarantee good results [54, 55] and re-osteosynthesis can be applied to few cases, even if in continuous increase. Also, we based our proposal of a therapeutic algorithm to reduce failures in PFFs’ treatment not only on the analyses of our series but also on the review of Literature [25, 28, 34, 42, 56]. Fractures with a stable stem (Vancouver B1 and C) are commonly treated by ORIF or by MIPO; ORIF can be enhanced with a structural allograft or with a second plate. The variety of methods and implants used, and their combinations implies that no “gold standard” exists. Elastic fixation (relative stability) with minimal soft-tissue damage seems to be preferred [24, 40, 57, 58], relying on biological potentiality of the fracture, while a rigid fixation (absolute stability) is advocate in some other cases [6, 41, 59]. Anyway, all Authors focused their attention over mechanical issues of the PFF [60, 61], without taking into account patient’s biological criteria. As for mechanical criteria, these are already well known. Characteristics of the fracture and type of hardware have been evaluated, with biomechanical studies [60, 62–69] confirming clinical remarks. The use of bicortical screws around the stem is preferable over cerclages alone or cerclages plus monocortical screws, even if a recent clinical study showed no differences in results when only proximal cables where used with a non-locking plate [70]. Also, it can be advisable to span the whole femur with the plate [71]. However, there are fracture’s patterns, such as the comminution/resorption of the medial cortex, the presence of a transverse or short oblique fracture at the tip of the stem, the comminution or poorness of bone-stock at fracture site, in which an adequate torsional/sagittal and bending stiffness cannot be guarantee by a lateral plate alone. In these cases, a second mechanical support appears useful. A structural allograft is recommended medially while anteriorly both a structural allograft or a second plate can be used [28, 56, 72–74], sounding better a medial than an anterior reinforcement [64]. A structural allograft is in our opinion better than a second plate as it can bring osteoconductive support as well, especially if a pharmacological anabolic treatment is performed. Anyway, mechanical elements are not the only factors that should indicate the use of a structural allograft, and biological issues has to be taken into account, as well. A PFF around or at the tip of a cemented stem [20, 75, 76] or over an osteoporotic bone are known to have higher complication rate than other cases [77]. Conditions such as osteoporosis and rheumatoid arthritis or other autoimmune or endocrinological diseases, long lasting CCSs or BPs assumption, AFFs or previous surgeries are indicators of a local and systemic biological impairment that suggest the use of structural allograft even if mechanically it would be unnecessary [6, 9, 31, 78]. Also, smoking is known to be a negative prognostic factor for bone healing, and it has been found in a systematic review as the only biological patient-depending risk factor for nonunion [79]. As for fracture’s healing, it is well known that an adequate environment includes mechanical stability and biological osteoconductive, osteoinductive and osteogenic support [80–82]. Also, metabolic pharmacological therapy with Teriparatide showed promising results when mechanical issues are present [73]. Our initial experience on re-fractures [52, 83–85], the one with AFFs when intramedullary nailing is not possible (over a deformed bone or in “periprosthetic” AFFs) [51] and with proximal femur fractures in the elderly (in which we always do a metabolic study of the patient, and eventually proposed an antiosteoporotic pharmacological treatment together to the Bone metabolism Unit) and the review of Literature [47, 86–88], lead us to proposed a surgical aggressive and combined pharmacological treatment even to some first-time PFFs. In such PFFs that may fail to heal because of mechanical or biological issues, we propose a combined mechanical-biological approach that consists in a rigid fixation (absolute stability) with a lateral plate and structural allograft (better if possible a double strut allograft, at 90° each other, medially and anteriorly) with apposition of autologous BMC & PRP at the fracture site plus medical therapy with Teriparatide in the postoperative period. In our experience it appeared evident that patients who already failed in previous fixation are likely to achieve a complete healing without further complications. We so developed a therapeutic algorithm, given the prosthetic stem to be stable (Vancouver type B1 and C) and willing to retain it, taking into account mechanical and biological criteria that could lead us to decide for such an aggressive approach even in first-time PFFs. Mechanical criteria can be major: 1) deficient medial cortex (resorption, wedge fracture or comminution), 2) inability to guarantee an adequate fixation around the stem with only the plate; or minor: 3) a transverse fracture at the tip of a stem, 4) fracture comminution, 5) poorness of bone-stock. Biological criteria can be local or systemic; local criteria are: 1) a fracture around a cemented stem, 2) estimated wide surgical dissection or a previous open access at the affected site, or 3) an atypical pattern of the fracture; systemic criteria are: 4) diseases affecting phosphocalcic metabolism (osteoporosis, rheumatic and/or autoimmune diseases, primary or secondary endocrinological diseases, osteomalacia, Paget’s disease, ..), 5) long lasting pharmacological therapies with CCSs or BPs, 6) heavy smoking ( ≥ one pack/day). Some of these biological criteria can link each other (for example: an atypical pattern of fracture seems more frequent in osteoporotic patients on long lasting BPs therapy) and can coexist. As for cemented stems, in our opinion it is more a biological issue than a mechanical one: an overlooked failure of the stem-cemented interface has been advocate as a mechanical cause of failure in PFFs around a cemented stem [29, 76] but a reduce capability of bone healing (less viable area, no endosteal callus formation) and an absent opportunity for re-osteointegration are biological issues that are undoubtedly present. Alike, a transverse fracture at the tip of the stem has always been considered a mechanical problem but it also implies biological issues (less surface for bone healing). If no criterion or just one minor mechanical criterion is present, a MIPO or ORIF technique achieving relative or absolute stability without adding any biological support can be indicated. If one major mechanical or one biological criterion is present, we prefer to perform ORIF with the addition of a medial cortical structural allograft, achieving absolute stability of the construct with some osteoconductive support. If two or more criteria are present (no matter if mechanical ones are major or minor), we suggest ORIF with double structural allograft plus osteoinductive/osteogenic support with autologous BMC and PRP at the site of the fracture. Post-operative systemic anabolic pharmacological therapy with Teriparatide can be added in all cases but, being an off label application, we reserve it to patients with one biological criterion or with two or more criteria (or in cases of delayed union). All proposed criteria to be taken into account are recapped in Table 4, and the proposed therapeutic algorithm in Fig. 4 . Onlay cortical structural allograft is a known option for the treatment of PFFs around a stable femoral stem as adjunctive fixation when a plate is used [89]. A structural allograft has both mechanical and biological properties: it confers stability to fracture site, allows a longer working length of the screws if put medially, it has osteconductive properties and it can incorporate and ultimately increase the femoral bone stock [90]. On the other hand, extensive soft tissue dissection and longer operating time for allograft application result in decreased periosteal blood supply to the fracture site and this can be a reason for a longer time-to-heal (even to nonunion) and a higher infection rate [41, 58, 91]. If we have only one structural allograft, we use to put it medially; anyway, it also depends on femoral bowing, level of fracture and length of the stem with revision stems more likely to need an anteriorly placed allograft as straight stem can head to the anterior cortex and stresses are to be counter on sagittal plane. Anyway, in our setting fresh frozen structural allograft are entire diaphyses and not emidiaphyseal, so we usually have the opportunity to use a double structural allograft. To reduce such a risk of delayed union or non-union related to extensive dissection, we look for osteoinductive ed osteogenic properties as well [49, 80–82]. BMC is derived from autologous bone marrow, and it is composed of a variety of cells, including mesenchymal stem cells that can contribute to the regeneration of mesenchymal tissues, capable of self-renewal and differentiation into various cell types such as bone, muscle, tendon and ligament. These properties have a positive influence on bone formation, neoangiogenesis and fracture healing [51, 83]. Also, a PRP-based membrane as a scaffold for BMC has already shown enhanced osteogenic and angiogenic properties [92]. Lastly, systemic anabolic support can be of help especially in biologically impaired patients. Parathormone (PTH) is a single-chain 84-aminoacid secreted polypeptide that plays a critical role among the calcium regulating hormones. Although hyperparathyroidism is associated with bone loss, intermittent administration of PTH or its N-terminal 1–34 fragment (Teriparatide) is known to increase bone mass, as anabolic properties of PTH dominate over its catabolic effects. Also, PTH acts upregulating the marker genes associated with osteoblast differentiation. Physiological PTH actions include stimulation of osteogenesis by direct effects on cells responsible of bone formation (osteoblasts) and indirectly by increasing intestinal absorption of calcium and increasing the renal tubular reabsorption of calcium and elimination of phosphate. Evidence is present in the Literature that Teriparatide can be useful in the treatment of nonunions, delayed unions and AFFs [47–52]. Also, in an animal model a combined administration of subcutaneous Teriparatide and systemic human mesenchymal stem cells showed a synergic positive effect on bone healing [93]. We therefore are proposing such an anabolic medical treatment, together with the Bone Metabolic Unit, in foreseeable difficult cases or when surgical dissection is wide and devascularization is likely. For those reasons, in our opinion, in selected cases it is worthwhile a more aggressive and multimodal approach to avoid re-fractures in PFFs. A more invasive surgery (rigid fixation and absolute stability of the fracture) with local biological support and systemic anabolic medical therapy are key to fracture healing. The intent of our study is to shift attention towards biological parameters to better frame the patient and avoid failures. More studies and even multicentric evaluation can be useful to validate or to reject this algorithm, and to evaluate eventual increase in other complications such as infections. Conclusions Nonunions, re-fractures and implant failures can happen after treatment of PFFs, the choice of a correct surgical strategy is essential to avoid new complications and ensure complete healing. In our experience, MIPO techniques do not always meet biological or mechanical criteria such as to make treatment with locking plate alone sufficient. On the other hand, ORIF especially if associated to structural allograft can jeopardize local vascularization due to the extensive exposure needed. Our therapeutic algorithm is designed to have a more complete vision of the patient and give a more satisfactory surgical approach to these fractures. Our biological and mechanical approach has been proven successful in re-fractures over PFFs cases and other impaired cases (such as AFFs). In our opinion such an approach already at first-time PFF can increase healing rates. Abbreviations 25(OH)D: cholecalciferol (vitamin D3) AFFs: atypical femoral fractures ALP: alkaline phosphatase BMC: bone marrow concentrate BPs: bisphosphonates Ca: calcium CCSs: corticosteroids CTX: C‐telopeptide of type I collagen HHS: Harris hip score MIPO: minimally invasive plate osteosynthesis ORIF: open reduction and internal fixation P: phosphorus P1NP: aminoterminal pro-peptide of type I procollagen PFF: periprosthetic femoral fractures PRP: platelet-rich plasma PTH: Parathormone Declarations Ethical approval : Not necessary at our Institution for such a work; the local Ethical Committee confirmed that no formal ethical approval was required. Consent to participate and for publication : All patients gave their consent to data collection and anonymous use of them for scientific and teaching purposes. Availability of data and material : raw data are available upon request to corresponding Author. Conflicts of interest/Competing interests : None to disclosure. 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J Arthroplasty 29:872–6. https://doi.org/10.1016/j.arth.2012.12.010 El Backly RM, Zaky SH, Muraglia A, et al (2013) A platelet-rich plasma-based membrane as a periosteal substitute with enhanced osteogenic and angiogenic properties: A new concept for bone repair. Tissue Eng - Part A 19:152–65. https://doi.org/10.1089/ten.tea.2012.0357 Cohn Yakubovich D, Sheyn D, Bez M, et al (2017) Systemic administration of mesenchymal stem cells combined with parathyroid hormone therapy synergistically regenerates multiple rib fractures. Stem Cell Res Ther 8:1–12. https://doi.org/10.1186/s13287-017-0502-9 Tables Table 1. Modified Vancouver classification of PFF. Modified Vancouver classification of PFF A Apophyseal A G around the greater trochanter A L around the lesser trochanter B Bed of implant B1 around the stem or just below it, stable stem B2 around the stem or just below it, loose stem, good bone-stock burst comminution, more frequent in cemented stem clamshell displaced fracture of medial cortex including residual neck, calcar and lesser trochanter, stem stable or loose, more frequent in uncemented stem reverse clamshell displaced fracture of lateral cortex with a “reverse obliquity” pattern, stem loose spiral more frequent in cemented stem B3 around the stem or just below it, loose stem, poor bone-stock C Clear of the implant well below the prosthesis Table 2. Proposed treatment for PFF according to modified Vancouver classification. Treatment of PFFs according to Vancouver types & subtypes A Apophyseal A G A GU undisplaced conservative A GD displaced ≥ 2 cm osteosynthesis A L conservative B Bed of implant B1 B1 U undisplaced conservative or osteosynthesis B1 B1 D displaced osteosynthesis B1 C at the tip of a cemented stem revision or osteosynthesis B2 B2 B burst revision B2 CS clamshell, stable stem* conservative or osteosynthesis B2 CL clamshell, loose stem revision B2 RS reverse clamshell, stable stem* conservative, osteosynthesis or revision B2 RL reverse clamshell, loose stem revision B2 S spiral revision B3 revision C Clear of the implant osteosynthesis * being the stem stable, they should not probably be considered as B2 PFFs and should be moved into B1 PFFs Table 3. Suggested “short” phosphocalcic metabolic panel, including only blood testing without any precise preparation nor a 24-hours urine collection. ALP: alkaline phosphatase, Ca: calcium, P: phosphorus, PTH: Parathormone, CTX: C‐telopeptide of type I collagen, P1NP: aminoterminal pro-peptide of type I procollagen, 25(OH)D: cholecalciferol (vitamin D3). Suggested “short” panel for phosphocalcic metabolism ALP, U/L (range 55–142) Ca, mg/dL (range 8.9–10.1) P, mg/dL (range 2.5–4.5) PTH, pg/mL (range 15–65) CTX, ng/L (range 100–700 over 50 years) P1NP, µg/L (range 15–75 over 50 years) 25(OH)D, ng/mL (range 30–100) Creatinine, mg/dL (range 0.6–1.1) Table 4. Criteria used in the proposed therapeutic algorithm. Mechanical criteria can be major or minor, biological criteria can be local or systemic. Mechanical criteria Biological criteria major minor local systemic deficient medial cortex ^ transverse fracture at the tip of a stem fracture around a cemented stem diseases affecting phosphocalcic metabolism § inability to guarantee an adequate fixation around the stem with only the plate fracture comminution estimated wide surgical dissection or a previous open access at the affected site long lasting pharmacological therapies with CCSs or BPs poorness of bone-stock atypical pattern of the fracture heavy smoking ^ resorption, wedge fracture or comminution § osteoporosis, rheumatic and/or autoimmune diseases, primary or secondary endocrinological diseases, osteomalacia, Paget’s disease, .. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-38837","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":799963,"identity":"6aa7060a-3544-4d5b-8ee4-b0cc4c7b1b8e","order_by":0,"name":"Nicola Mondanelli","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/0lEQVRIiWNgGAWjYDACZiB+AGEaALGFDBt7AwNDAoMEAxs+LQkILRI8bDwHoFpw6kHXwiAB5eKyxpyd+eGDhBqGaH7p5o2fCyokePgk35g9ePDHgoFPvgGrFstmNmODhGMMuTPnHCuWnnEG6DDpHHODxDbcDjM4zMMmkcDGkLvhRo6BNG8bWIuZRGIDIS3/wFqMf/P+A2qRPGMmkfCHgJbENrAWM2neBqAWCR6gFjZ8WoB+SeyTyJ05I63MmucYKJDTyoCGABlsCdi1nD/88MGHbza5/RLJm2/z1NjIybcf3ib540+dnHzzAezWQIAEphAPPvWjYBSMglEwCvADAC2ZSYCQ6N4JAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-0684-4197","institution":"Universita degli Studi di Siena","correspondingAuthor":true,"prefix":"","firstName":"Nicola","middleName":"","lastName":"Mondanelli","suffix":""},{"id":799964,"identity":"c51ee28c-026e-4424-98a2-52d21b3421c8","order_by":1,"name":"Giovanni Battista Colasanti","email":"","orcid":"","institution":"Universita degli Studi di Siena","correspondingAuthor":false,"prefix":"","firstName":"Giovanni","middleName":"Battista","lastName":"Colasanti","suffix":""},{"id":799965,"identity":"994aa972-7ef6-49b9-9e60-8bc55e599d77","order_by":2,"name":"Carlo Cataldi","email":"","orcid":"","institution":"Universita degli Studi di Siena","correspondingAuthor":false,"prefix":"","firstName":"Carlo","middleName":"","lastName":"Cataldi","suffix":""},{"id":799966,"identity":"5398611f-21a6-43a9-be2e-497a5c2279fa","order_by":3,"name":"Fabio Moreschini","email":"","orcid":"","institution":"Universita degli Studi di Siena","correspondingAuthor":false,"prefix":"","firstName":"Fabio","middleName":"","lastName":"Moreschini","suffix":""},{"id":799967,"identity":"1786de9b-2d9c-431f-954f-bbe71ee4e82c","order_by":4,"name":"Vanna Bottai","email":"","orcid":"","institution":"Universita degli Studi di Pisa","correspondingAuthor":false,"prefix":"","firstName":"Vanna","middleName":"","lastName":"Bottai","suffix":""},{"id":799968,"identity":"c0a56d2f-e9fa-4140-85a5-f7c314c082ed","order_by":5,"name":"Stefano Giannotti","email":"","orcid":"","institution":"Universita degli Studi di Siena","correspondingAuthor":false,"prefix":"","firstName":"Stefano","middleName":"","lastName":"Giannotti","suffix":""}],"badges":[],"createdAt":"2020-06-29 09:22:41","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-38837/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-38837/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":1554464,"identity":"306ed0fe-1bf8-4678-a690-dc22afe11ae6","added_by":"auto","created_at":"2020-07-14 17:03:29","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":166866,"visible":true,"origin":"","legend":"A Vancouver type B1 PFF. B, Elastic fixation with relative stability with MIPO; medial comminution not addressed, only cables by necessity in the proximal fragment. C, transverse nonunion (medial comminuted fragments united to distal major segment) at 14 months; plate breakage occurred a month later. D, E, healing occurred at six months after revision surgery.","description":"","filename":"Fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-38837/v1/Fig1.jpg"},{"id":1554465,"identity":"2dbf0ded-9802-4ac9-9fd3-4133da2e8c26","added_by":"auto","created_at":"2020-07-14 17:03:29","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":162200,"visible":true,"origin":"","legend":"A, Vancouver type C PFF. B, initial treatment with ORIF (plate and screws and cerclages, and a cortical strut), allograft fractured during fixation and medial buttress was lost. C, histological finding of giant osteoblasts (arrows) consistent with an AFF. D, plate breakage at months. E, the fracture healed at six months.","description":"","filename":"Fig2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-38837/v1/Fig2.jpg"},{"id":1554466,"identity":"1b110f07-8d4f-47ea-8e5c-582de0ac7502","added_by":"auto","created_at":"2020-07-14 17:03:30","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":137040,"visible":true,"origin":"","legend":"A, B, a Vancouver type C PFF treated with absolute stability (ORIF) and apposition of morcellized allograft. C, Plate breakage and re-fracture at four months. D, E, radiographs at six months showed complete healing, re-fixation was done with a long plate to bridge the stem.","description":"","filename":"Fig3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-38837/v1/Fig3.jpg"},{"id":1554467,"identity":"811c4f78-a041-4a80-b99a-8996c0212c61","added_by":"auto","created_at":"2020-07-14 17:03:30","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":78845,"visible":true,"origin":"","legend":"The proposed therapeutic algorithm for periprosthetic femoral fractures over a stable stem (Vancouver type B1 and C). In case of two or more criteria, no matter if mechanical ones are major or minor.","description":"","filename":"Fig4.JPG","url":"https://assets-eu.researchsquare.com/files/rs-38837/v1/Fig4.JPG"},{"id":13551039,"identity":"504f5b67-7daa-4a77-a5b9-3db761fbfc7b","added_by":"auto","created_at":"2021-09-17 02:27:05","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":643871,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-38837/v1/072eda20-01b5-4494-9dcd-bcee90752060.pdf"}],"financialInterests":"","formattedTitle":"\u003cp\u003eCombined Surgical And Medical Treatment For Periprosthetic Femoral Fractures Over A Stable Stem (Vancouver Type B1 And C): A Proposal Of A Therapeutic Algorithm To Reduce The Risk Of Nonunion.\u003c/p\u003e","fulltext":[{"header":"Background","content":" \u003cp\u003eThe incidence of periprosthetic femoral fractures (PFFs) is reported to be between 1% and 11% over a primary hip femoral stem and up to 18% over a revised hip femoral stem [\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Their treatment is based on level of fracture, implant stability and quality of bone stock, and the comorbidity of the patient [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan additionalcitationids=\"CR7 CR8\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. The Vancouver classification developed by Duncan and Masri [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] is the most widely used for guiding the surgeon in pre-operative planning [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], and it has been developed into the Unified Classification System for Periprosthetic Fractures [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. New patterns of fracture has also been described for PFF around a hip femoral stem, with different prevalence over uncemented or cemented stem and apparently over stem geometry [\u003cspan additionalcitationids=\"CR17 CR18 CR19 CR20\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Modified Vancouver classification and correspondent proposed treatment from Literature are shown in Tables\u0026nbsp;1 and 2, respectively. Anyway, there is no clear consensus on the optimal method of treatment for fractures around a stable femoral stem hip implant [\u003cspan additionalcitationids=\"CR23\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Type B1 fractures represent 30% and type C fractures represent 10% of all PFFs, and their treatment can be associated to a higher risk of complication than other PFFs types and high risk of failure due to nonunion with implant loosening and/or re-fracture [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan additionalcitationids=\"CR26 CR27 CR28 CR29 CR30\" citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Clearly, this entails an important economic expense [\u003cspan additionalcitationids=\"CR33\" citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] and a high rate of morbidity and disability for these patients; moreover, mortality after PFFs and their treatment varies with patient age and concomitant disease between 4.5% and 22% [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan additionalcitationids=\"CR36 CR37 CR38\" citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo date, most of the studies have produced therapeutic algorithms that focus on implant stability, leaving the choice of treatment to the habit of the surgeon, not defining the best surgical strategy; both minimally invasive plate osteosynthesis (MIPO) obtaining an elastic fixation or open reduction and internal fixation (ORIF) with plate and cerclage with or without a structural allograft (or a second plate) have been advocated, based on mechanical issues [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan additionalcitationids=\"CR41 CR42 CR43 CR44\" citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. Anyway, the biological aspect of the patient has been neglected, considering it as not fundamental for the type of PFF and the surgical approach. Instead, patients with prostheses can present biological systemic and local issues that commonly include multiple medical comorbidities and long lasting medical therapies, and difficulties with postoperative rehabilitation [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. Also, the PFF can happen over a bone of very poor quality and/or present a pattern such that mechanical issues are not the only local factors to consider to be deficient.\u003c/p\u003e \u003cp\u003eMoreover, studies are present in the literature suggesting that Teriparatide can be usefull in fractures\u0026rsquo; and nonunions\u0026rsquo; management as well as for osteoporosis [47\u0026ndash;52]. This drug works by stimulating osteoblasts and reducing osteoblast apoptosis, increasing callus formation, improving mechanical strength, and resulting in increased osteoblast life span. To date, Teriparatide is often prescribed to promote bone healing, especially in femoral shaft fractures occurred in patients treated with bisphosphonates (BPs) for a long period.\u003c/p\u003e \u003cp\u003eThe aim of this paper is to propose an algorithm of treatment of PFFs over a stable stem (Vancouver B1 and C types), taking into account both mechanical and biological (local and systemic) criteria that can guide the surgeon in choosing the ideal approach, based on results in the Literature and starting from our own results in the treatment of re-fractures / nonunions on PFFs and other challenging cases as atypical femoral fractures (AFFs) over deformed bones or re-fractures over an implant.\u003c/p\u003e "},{"header":"Methods","content":" \u003cp\u003eWe retrospectively reviewed data of patients who failed to heal after fixation for a PFF, classified as Vancouver type B1 or C, whose re-fractures / nonunions we successfully treated with a combined surgical and medical approach with femoral stem retention.\u003c/p\u003e \u003cp\u003eWe surgically aimed to a rigid fixation (absolute stability) plus biological (osteoconductive, osteoinductive and osteogenic) support. All patients were treated using a low contact lateral plate with polyaxial angular stability screws and cerclages (NCB system, ZimmerBiomet, Warsaw, IN, USA) or a compression plate with screws and cerclages (Cable-Ready Extended GTR Plate, ZimmerBiomet, Warsaw, IN, USA), a double cortical structural fresh frozen allograft (medially and anteriorly placed, at 90\u0026deg; each other; mechanical and osteoconductive support) and local apposition of autologous bone marrow cells concentrate (BMC) embedded in an autologous platelet-rich plasma (PRP)-based membrane (Regenkit BMC and Regenkit Extracell Membrane glue, RegenLab, Le Mont-sur-Lousanne, CH) at fracture site (osteoinductive and osteogenic support). All patients were also pharmacologically treated with Teriparatide (Forsteo, Eli Lilly and Company, Indianapolis, IN, USA) in the postoperative period for at least three months. Teriparatide was prescribed \u003cem\u003eoff label\u003c/em\u003e after adequate informed consent was acquired and under guidance of the Bone Metabolic Unit. Outpatient follow-up was performed at 1, 3, 6, 9 and 12 months after surgery and then annually, including subjective and clinical evaluation with Harris hip score (HHS) [53] and radiographical evaluation.\u003c/p\u003e \u003cp\u003eWe studied all radiographs of the patients: pre-operative and post-operative radiographs relative to the first fixation surgery were analysed for potential bone defects, unadvised stem loosening and possible surgical technical errors, and actual radiographs after the re-fracture and in subsequent follow-up visits for fracture healing. All patients were studied for phosphocalcic metabolism before surgery (Table\u0026nbsp;3), and patient\u0026rsquo;s history was analysed for biological impairment that could be initially unadvised. In some patients, also, a histological study of the nonunion area was performed. Based on these findings, we set up a list of biological local and systemic criteria to be taken into consideration as risk factors for nonunion together with mechanical criteria. All cases were reviewed and evaluated regarding these proposed criteria.\u003c/p\u003e \u003cp\u003eAt our Institutions, no Institutional Review Board nor Ethical Committee Approval is necessary for retrospective studies, and patients gave their consent to data collection and anonymous use of them for scientific and teaching purposes.\u003c/p\u003e "},{"header":"Results","content":" \u003cp\u003eWe present, as example, the cases of the three patients operated on of revision of osteosynthesis with retention of the stem for nonunion over a PFFs with a stable stem. We analysed the reason why, in our opinion, the PFF did not heal and looked for associated biological factors that could justify an increased risk.\u003c/p\u003e \u003cp\u003eIn the first patient, a 80-years-old female, (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) the PFF was at the tip of an uncemented tapered fluted long revision stem (Vancouver type B1) positioned five years before (second stem revision on a dysplastic hip); she had being on BPs for seven years. Breakage of the plate occurred at 15\u0026nbsp;months from first osteosynthesis, with revision surgery already scheduled for nonunion. She had no impairment of phosphocalcic metabolism, but it appeared evident that technical errors had been made, the medial cortex comminution not being addressed and, as for the fixation, only cables were used by necessity in the proximal fragment: the femur was very small and completely filled with the stem. Histology showed fibrocartilaginous tissue with some bony islands with osteoclasts and fibroblastic cells, with very rare osteoblasts. At re-fracture surgery, proximal fixation was still with only cables by necessity, but the whole femur was spanned, and rigid fixation was achieved with compression of the structural allograft to the host diaphysis. Bone healing was well evident at three months post-operatively, and it appeared complete at six months.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe second patient was a 77-years-old female (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) who experienced a type C PFF over an uncemented double-wedge stem positioned 12\u0026nbsp;years before for a fragility fracture of the femoral neck; since then, she had been on BPs therapy. She presented hypovitaminosis D, and at surgery histological findings of giant osteoblasts consistent with an AFF were found. No gross surgical errors were evident but the medially placed structural allograft fractured during fixation, so medial buttress was lost. Also, in the first post-operative period, patient did not assume the prescribed therapy with Teriparatide. At re-fracture surgery, three months after, a hooked plate with only proximal cerclages was used; again, absolute stability was guarantee by compression of the plate and the structural allograft to the host diaphysis. Radiographic bone healing occurred at six months post-operatively.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe third patient (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) was a 76-years-old female on chronic corticosteroid (CCS) therapy for myasthenia gravis and presented hypoparathyroidism secondary to a thymoma; she experienced a PFF clear of an uncemented tapered rectangular stem positioned ten years before for hip osteoarthritis; ORIF with morselized bone graft impacted into the medullary canal was performed; fixation was adequate but possibly too much dissection was carried on to access the fracture, resulting in possibly excessive devascularization. Plate breakage occurred at four months from initial surgery; at re-fixation, histology showed nonunion with almost total absence of osteoblasts. A long plate was used, also to bridge the stem with a proximal cerclage to avoid a stress riser between the tip of the stem and a shorter osteosynthesis.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAll patients underwent complete clinical and radiographic healing over a six months period, and functional recovery appears to be satisfactory with progressive increase in HHS records. All patients presented more mechanical and biological criteria as risk factors for nonunion, and based on the therapeutic algorithm, they should have been operated on for the first-time PFF with the multimodal combined surgical and medical approach we propose.\u003c/p\u003e "},{"header":"Discussion","content":" \u003cp\u003eThe main limitations of this study are the small group of patients we analysed and the absence of a control group. Anyway, we focused on a particular group of patients presenting re-fracture / nonunion of a PFF that were treated with repeated osteosynthesis and stem retention: revision arthroplasty for failed osteosyntheses can guarantee good results [54, 55] and re-osteosynthesis can be applied to few cases, even if in continuous increase. Also, we based our proposal of a therapeutic algorithm to reduce failures in PFFs\u0026rsquo; treatment not only on the analyses of our series but also on the review of Literature [25, 28, 34, 42, 56]. Fractures with a stable stem (Vancouver B1 and C) are commonly treated by ORIF or by MIPO; ORIF can be enhanced with a structural allograft or with a second plate. The variety of methods and implants used, and their combinations implies that no \u0026ldquo;gold standard\u0026rdquo; exists. Elastic fixation (relative stability) with minimal soft-tissue damage seems to be preferred [24, 40, 57, 58], relying on biological potentiality of the fracture, while a rigid fixation (absolute stability) is advocate in some other cases [6, 41, 59]. Anyway, all Authors focused their attention over mechanical issues of the PFF [60, 61], without taking into account patient\u0026rsquo;s biological criteria.\u003c/p\u003e \u003cp\u003eAs for mechanical criteria, these are already well known. Characteristics of the fracture and type of hardware have been evaluated, with biomechanical studies [60, 62\u0026ndash;69] confirming clinical remarks. The use of bicortical screws around the stem is preferable over cerclages alone or cerclages plus monocortical screws, even if a recent clinical study showed no differences in results when only proximal cables where used with a non-locking plate [70]. Also, it can be advisable to span the whole femur with the plate [71]. However, there are fracture\u0026rsquo;s patterns, such as the comminution/resorption of the medial cortex, the presence of a transverse or short oblique fracture at the tip of the stem, the comminution or poorness of bone-stock at fracture site, in which an adequate torsional/sagittal and bending stiffness cannot be guarantee by a lateral plate alone. In these cases, a second mechanical support appears useful. A structural allograft is recommended medially while anteriorly both a structural allograft or a second plate can be used [28, 56, 72\u0026ndash;74], sounding better a medial than an anterior reinforcement [64]. A structural allograft is in our opinion better than a second plate as it can bring osteoconductive support as well, especially if a pharmacological anabolic treatment is performed.\u003c/p\u003e \u003cp\u003eAnyway, mechanical elements are not the only factors that should indicate the use of a structural allograft, and biological issues has to be taken into account, as well. A PFF around or at the tip of a cemented stem [20, 75, 76] or over an osteoporotic bone are known to have higher complication rate than other cases [77]. Conditions such as osteoporosis and rheumatoid arthritis or other autoimmune or endocrinological diseases, long lasting CCSs or BPs assumption, AFFs or previous surgeries are indicators of a local and systemic biological impairment that suggest the use of structural allograft even if mechanically it would be unnecessary [6, 9, 31, 78]. Also, smoking is known to be a negative prognostic factor for bone healing, and it has been found in a systematic review as the only biological patient-depending risk factor for nonunion [79].\u003c/p\u003e \u003cp\u003eAs for fracture\u0026rsquo;s healing, it is well known that an adequate environment includes mechanical stability and biological osteoconductive, osteoinductive and osteogenic support [80\u0026ndash;82]. Also, metabolic pharmacological therapy with Teriparatide showed promising results when mechanical issues are present [73].\u003c/p\u003e \u003cp\u003eOur initial experience on re-fractures [52, 83\u0026ndash;85], the one with AFFs when intramedullary nailing is not possible (over a deformed bone or in \u0026ldquo;periprosthetic\u0026rdquo; AFFs) [51] and with proximal femur fractures in the elderly (in which we always do a metabolic study of the patient, and eventually proposed an antiosteoporotic pharmacological treatment together to the Bone metabolism Unit) and the review of Literature [47, 86\u0026ndash;88], lead us to proposed a surgical aggressive and combined pharmacological treatment even to some first-time PFFs.\u003c/p\u003e \u003cp\u003eIn such PFFs that may fail to heal because of mechanical or biological issues, we propose a combined mechanical-biological approach that consists in a rigid fixation (absolute stability) with a lateral plate and structural allograft (better if possible a double strut allograft, at 90\u0026deg; each other, medially and anteriorly) with apposition of autologous BMC \u0026amp; PRP at the fracture site plus medical therapy with Teriparatide in the postoperative period. In our experience it appeared evident that patients who already failed in previous fixation are likely to achieve a complete healing without further complications.\u003c/p\u003e \u003cp\u003eWe so developed a therapeutic algorithm, given the prosthetic stem to be stable (Vancouver type B1 and C) and willing to retain it, taking into account mechanical and biological criteria that could lead us to decide for such an aggressive approach even in first-time PFFs. Mechanical criteria can be major: 1) deficient medial cortex (resorption, wedge fracture or comminution), 2) inability to guarantee an adequate fixation around the stem with only the plate; or minor: 3) a transverse fracture at the tip of a stem, 4) fracture comminution, 5) poorness of bone-stock. Biological criteria can be local or systemic; local criteria are: 1) a fracture around a cemented stem, 2) estimated wide surgical dissection or a previous open access at the affected site, or 3) an atypical pattern of the fracture; systemic criteria are: 4) diseases affecting phosphocalcic metabolism (osteoporosis, rheumatic and/or autoimmune diseases, primary or secondary endocrinological diseases, osteomalacia, Paget\u0026rsquo;s disease, ..), 5) long lasting pharmacological therapies with CCSs or BPs, 6) heavy smoking (\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u0026ge;\u003c/span\u003e\u0026thinsp;one pack/day).\u003c/p\u003e \u003cp\u003eSome of these biological criteria can link each other (for example: an atypical pattern of fracture seems more frequent in osteoporotic patients on long lasting BPs therapy) and can coexist. As for cemented stems, in our opinion it is more a biological issue than a mechanical one: an overlooked failure of the stem-cemented interface has been advocate as a mechanical cause of failure in PFFs around a cemented stem [29, 76] but a reduce capability of bone healing (less viable area, no endosteal callus formation) and an absent opportunity for re-osteointegration are biological issues that are undoubtedly present. Alike, a transverse fracture at the tip of the stem has always been considered a mechanical problem but it also implies biological issues (less surface for bone healing).\u003c/p\u003e \u003cp\u003eIf no criterion or just one minor mechanical criterion is present, a MIPO or ORIF technique achieving relative or absolute stability without adding any biological support can be indicated. If one major mechanical or one biological criterion is present, we prefer to perform ORIF with the addition of a medial cortical structural allograft, achieving absolute stability of the construct with some osteoconductive support. If two or more criteria are present (no matter if mechanical ones are major or minor), we suggest ORIF with double structural allograft plus osteoinductive/osteogenic support with autologous BMC and PRP at the site of the fracture. Post-operative systemic anabolic pharmacological therapy with Teriparatide can be added in all cases but, being an \u003cem\u003eoff label\u003c/em\u003e application, we reserve it to patients with one biological criterion or with two or more criteria (or in cases of delayed union). All proposed criteria to be taken into account are recapped in Table\u0026nbsp;4, and the proposed therapeutic algorithm in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eOnlay cortical structural allograft is a known option for the treatment of PFFs around a stable femoral stem as adjunctive fixation when a plate is used [89]. A structural allograft has both mechanical and biological properties: it confers stability to fracture site, allows a longer working length of the screws if put medially, it has osteconductive properties and it can incorporate and ultimately increase the femoral bone stock [90]. On the other hand, extensive soft tissue dissection and longer operating time for allograft application result in decreased periosteal blood supply to the fracture site and this can be a reason for a longer time-to-heal (even to nonunion) and a higher infection rate [41, 58, 91]. If we have only one structural allograft, we use to put it medially; anyway, it also depends on femoral bowing, level of fracture and length of the stem with revision stems more likely to need an anteriorly placed allograft as straight stem can head to the anterior cortex and stresses are to be counter on sagittal plane. Anyway, in our setting fresh frozen structural allograft are entire diaphyses and not emidiaphyseal, so we usually have the opportunity to use a double structural allograft.\u003c/p\u003e \u003cp\u003eTo reduce such a risk of delayed union or non-union related to extensive dissection, we look for osteoinductive ed osteogenic properties as well [49, 80\u0026ndash;82]. BMC is derived from autologous bone marrow, and it is composed of a variety of cells, including mesenchymal stem cells that can contribute to the regeneration of mesenchymal tissues, capable of self-renewal and differentiation into various cell types such as bone, muscle, tendon and ligament. These properties have a positive influence on bone formation, neoangiogenesis and fracture healing [51, 83]. Also, a PRP-based membrane as a scaffold for BMC has already shown enhanced osteogenic and angiogenic properties [92].\u003c/p\u003e \u003cp\u003eLastly, systemic anabolic support can be of help especially in biologically impaired patients. Parathormone (PTH) is a single-chain 84-aminoacid secreted polypeptide that plays a critical role among the calcium regulating hormones. Although hyperparathyroidism is associated with bone loss, intermittent administration of PTH or its N-terminal 1\u0026ndash;34 fragment (Teriparatide) is known to increase bone mass, as anabolic properties of PTH dominate over its catabolic effects. Also, PTH acts upregulating the marker genes associated with osteoblast differentiation. Physiological PTH actions include stimulation of osteogenesis by direct effects on cells responsible of bone formation (osteoblasts) and indirectly by increasing intestinal absorption of calcium and increasing the renal tubular reabsorption of calcium and elimination of phosphate. Evidence is present in the Literature that Teriparatide can be useful in the treatment of nonunions, delayed unions and AFFs [47\u0026ndash;52]. Also, in an animal model a combined administration of subcutaneous Teriparatide and systemic human mesenchymal stem cells showed a synergic positive effect on bone healing [93].\u003c/p\u003e \u003cp\u003eWe therefore are proposing such an anabolic medical treatment, together with the Bone Metabolic Unit, in foreseeable difficult cases or when surgical dissection is wide and devascularization is likely.\u003c/p\u003e \u003cp\u003eFor those reasons, in our opinion, in selected cases it is worthwhile a more aggressive and multimodal approach to avoid re-fractures in PFFs. A more invasive surgery (rigid fixation and absolute stability of the fracture) with local biological support and systemic anabolic medical therapy are key to fracture healing. The intent of our study is to shift attention towards biological parameters to better frame the patient and avoid failures. More studies and even multicentric evaluation can be useful to validate or to reject this algorithm, and to evaluate eventual increase in other complications such as infections.\u003c/p\u003e "},{"header":"Conclusions","content":" \u003cp\u003eNonunions, re-fractures and implant failures can happen after treatment of PFFs, the choice of a correct surgical strategy is essential to avoid new complications and ensure complete healing. In our experience, MIPO techniques do not always meet biological or mechanical criteria such as to make treatment with locking plate alone sufficient. On the other hand, ORIF especially if associated to structural allograft can jeopardize local vascularization due to the extensive exposure needed. Our therapeutic algorithm is designed to have a more complete vision of the patient and give a more satisfactory surgical approach to these fractures. Our biological and mechanical approach has been proven successful in re-fractures over PFFs cases and other impaired cases (such as AFFs). In our opinion such an approach already at first-time PFF can increase healing rates.\u003c/p\u003e "},{"header":"Abbreviations","content":"\u003cp\u003e25(OH)D: cholecalciferol (vitamin D3)\u003c/p\u003e\n\u003cp\u003eAFFs: atypical femoral fractures\u003c/p\u003e\n\u003cp\u003eALP: alkaline phosphatase\u003c/p\u003e\n\u003cp\u003eBMC: bone marrow concentrate\u003c/p\u003e\n\u003cp\u003eBPs: bisphosphonates\u003c/p\u003e\n\u003cp\u003eCa: calcium\u003c/p\u003e\n\u003cp\u003eCCSs: corticosteroids\u003c/p\u003e\n\u003cp\u003eCTX: C‐telopeptide of type I collagen\u003c/p\u003e\n\u003cp\u003eHHS: Harris hip score\u003c/p\u003e\n\u003cp\u003eMIPO: minimally invasive plate osteosynthesis\u003c/p\u003e\n\u003cp\u003eORIF: open reduction and internal fixation\u003c/p\u003e\n\u003cp\u003eP: phosphorus\u003c/p\u003e\n\u003cp\u003eP1NP: aminoterminal pro-peptide of type I procollagen\u003c/p\u003e\n\u003cp\u003ePFF: periprosthetic femoral fractures\u003c/p\u003e\n\u003cp\u003ePRP: platelet-rich plasma\u003c/p\u003e\n\u003cp\u003ePTH: Parathormone\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e: Not necessary at our Institution for such a work; the local Ethical Committee confirmed that no formal ethical approval was required.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate and for publication\u003c/strong\u003e: All patients gave their consent to data collection and anonymous use of them for scientific and teaching purposes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e: raw data are available upon request to corresponding Author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest/Competing interests\u003c/strong\u003e: None to disclosure.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: None received.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e: NM conceptualized the study, wrote and reviewed the paper, cured editing. GBC, FM and CC cured data acquisition, collection and analysis, and interpreted the data and drafted the work. VB and SG conceptualized the study, wrote and reviewed the paper. All Authors approved the submitted version and agree to be accountable for all aspects of the work.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLindahl H, Malchau H, Herberts P, Garellick G (2005) Periprosthetic femoral fractures: Classification and demographics of 1049 periprosthetic femoral fractures from the Swedish National Hip Arthroplasty Register. J Arthroplasty 20:857\u0026ndash;65. https://doi.org/10.1016/j.arth.2005.02.001\u003c/li\u003e\n\u003cli\u003eCapone A, Congia S, Civinini R, Marongiu G (2017) Periprosthetic fractures: epidemiology and current treatment. 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J Orthop Trauma 29:e364-70. https://doi.org/0.1097/BOT.0000000000000365\u003c/li\u003e\n\u003cli\u003eWilson D, Frei H, Masri BA, et al (2005) A biomechanical study comparing cortical onlay allograft struts and plates in the treatment of periprosthetic femoral fractures. Clin Biomech 20:70\u0026ndash;6. https://doi.org/10.1016/j.clinbiomech.2004.08.008\u003c/li\u003e\n\u003cli\u003eYang TC, Tzeng YH, Wang CS, et al (2019) Are proximal screws necessary for osteosynthesis of stable-stem periprosthetic femoral fractures fixed with non-locking plate and cable? Injury 50:1739\u0026ndash;44. https://doi.org/10.1016/j.injury.2019.06.009\u003c/li\u003e\n\u003cli\u003eMoloney GB, Westrick ER, Siska PA, Tarkin IS (2014) Treatment of periprosthetic femur fractures around a well-fixed hip arthroplasty implant: Span the whole bone. Arch Orthop Trauma Surg 134:9\u0026ndash;14. https://doi.org/10.1007/s00402-013-1883-6\u003c/li\u003e\n\u003cli\u003eButtaro MA, Farfalli G, Paredes N\u0026uacute;\u0026ntilde;ez M, et al (2007) Locking compression plate fixation of vancouver type-B1 periprosthetic femoral fractures. J Bone Jt Surg - Am Vol 89-A:1964\u0026ndash;9. https://doi.org/10.2106/JBJS.F.01224\u003c/li\u003e\n\u003cli\u003eTom\u0026aacute;s Hern\u0026aacute;ndez J, Holck K (2015) Periprosthetic femoral fractures: When i use strut grafts and why? Injury 46:S43-6. https://doi.org/10.1016/j.injury.2015.08.012\u003c/li\u003e\n\u003cli\u003eYeo I, Rhyu KH, Kim SM, et al (2016) High union rates of locking compression plating with cortical strut allograft for type B1 periprosthetic femoral fractures. Int Orthop 40:2365\u0026ndash;71. https://doi.org/10.1007/s00264-015-3107-x\u003c/li\u003e\n\u003cli\u003eCassidy JT, Kenny P, Keogh P (2018) Failed osteosynthesis of cemented B1 periprosthetic fractures. Injury 49:1927\u0026ndash;30. https://doi.org/10.1016/j.injury.2018.07.030\u003c/li\u003e\n\u003cli\u003eChakrabarti D, Thokur N, Ajnin S (2019) Cable plate fixation for Vancouver Type-B1 periprosthetic femoral fractures-Our experience and identification of a subset at risk of non-union. Injury 50:2301\u0026ndash;5. https://doi.org/10.1016/j.injury.2019.10.012\u003c/li\u003e\n\u003cli\u003eLenz M, Lehmann W, W\u0026auml;hnert D (2016) Periprosthetic fracture fixation in osteoporotic bone. Injury 47:S44-50. https://doi.org/10.1016/S0020-1383(16)47008-7\u003c/li\u003e\n\u003cli\u003eKhashan M, Amar E, Drexler M, et al (2013) Superior outcome of strut allograft-augmented plate fixation for the treatment of periprosthetic fractures around a stable femoral stem. Injury 44:1556\u0026ndash;60. https://doi.org/10.1016/j.injury.2013.04.025\u003c/li\u003e\n\u003cli\u003eSantolini E, West R, Giannoudis P V. (2015) Risk factors for long bone fracture non-union: A stratification approach based on the level of the existing scientific evidence. Injury 46:S8-19. https://doi.org/10.1016/S0020-1383(15)30049-8\u003c/li\u003e\n\u003cli\u003eAndrzejowski P, Giannoudis P V. (2019) The \u0026lsquo;diamond concept\u0026rsquo; for long bone non-union management. J. Orthop. Traumatol. 20:1\u0026ndash;13\u003c/li\u003e\n\u003cli\u003eFayaz HC, Giannoudis P V., Vrahas MS, et al (2011) The role of stem cells in fracture healing and nonunion. Int. Orthop. 35:1587\u0026ndash;97\u003c/li\u003e\n\u003cli\u003eGiannoudis P V., Einhorn TA, Marsh D (2007) Fracture healing: The diamond concept. Injury 38:S3-6. https://doi.org/10.1016/S0020-1383(08)70003-2\u003c/li\u003e\n\u003cli\u003eGiannotti S, Parchi PD, Colasanti GB, et al (2017) Use of autologous bone marrow cells concentrate enriched with platelet-fibrin on extensor mechanism allograft reconstruction for extensor mechanism failure following total knee arthroplasty. J Biol Regul Homeost Agents 31:107\u0026ndash;111\u003c/li\u003e\n\u003cli\u003eGiannotti S, Bottai V, Dell\u0026rsquo;Osso G, et al (2013) Pseudoarthrosis in atypical femoral fracture: Case report. Osteoporos Int 24:2893\u0026ndash;5. https://doi.org/10.1007/s00198-013-2397-3\u003c/li\u003e\n\u003cli\u003eBottai V, De Paola G, Celli F, et al (2017) Histological study of atraumatic periprosthetic fractures: does atypical periprosthetic fracture exist? Clin Cases Miner Bone Metab 14:136\u0026ndash;9. https://doi.org/10.11138/ccmbm/2017.14.1.136\u003c/li\u003e\n\u003cli\u003eYu W, Guo X (2017) Teriparatide treatment of femoral fracture nonunion that autogenous bone grafting failed to heal: a case report. Arch Osteoporos 12:15. https://doi.org/10.1007/s11657-017-0311-x\u003c/li\u003e\n\u003cli\u003eXiaofeng L, Daxia X, Yunzhen C (2017) Teriparatide as a nonoperative treatment for tibial and femoral fracture nonunion: A case report. Med 96:e6571. https://doi.org/10.1097/MD.0000000000006571\u003c/li\u003e\n\u003cli\u003eLee YK, Ha YC, Koo KH (2012) Teriparatide, a nonsurgical solution for femoral nonunion? A report of three cases. Osteoporos Int. https://doi.org/10.1007/s00198-012-2172-x\u003c/li\u003e\n\u003cli\u003eBrady OH, Garbuz DS, Masri BA, Duncan CP (1999) The treatment of periprosthetic fractures of the femur using cortical onlay allograft struts. Orthop Clin North Am 30:249\u0026ndash;57. https://doi.org/10.1016/S0030-5898(05)70079-1\u003c/li\u003e\n\u003cli\u003eBurchardt H (1987) Biology of bone transplantation. Orthop Clin North Am 18:187\u0026mdash;96\u003c/li\u003e\n\u003cli\u003eMoore RE, Baldwin K, Austin MS, Mehta S (2014) A systematic review of open reduction and internal fixation of periprosthetic femur fractures with or without allograft strut, cerclage, and locked plates. J Arthroplasty 29:872\u0026ndash;6. https://doi.org/10.1016/j.arth.2012.12.010\u003c/li\u003e\n\u003cli\u003eEl Backly RM, Zaky SH, Muraglia A, et al (2013) A platelet-rich plasma-based membrane as a periosteal substitute with enhanced osteogenic and angiogenic properties: A new concept for bone repair. Tissue Eng - Part A 19:152\u0026ndash;65. https://doi.org/10.1089/ten.tea.2012.0357\u003c/li\u003e\n\u003cli\u003eCohn Yakubovich D, Sheyn D, Bez M, et al (2017) Systemic administration of mesenchymal stem cells combined with parathyroid hormone therapy synergistically regenerates multiple rib fractures. Stem Cell Res Ther 8:1\u0026ndash;12. https://doi.org/10.1186/s13287-017-0502-9\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1. Modified Vancouver classification of PFF.\u003c/strong\u003e\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Taba\" border=\"1\"\u003e \u003ccolgroup cols=\"7\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eModified Vancouver classification of PFF\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eApophyseal\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003csub\u003eG\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003earound the greater trochanter\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003csub\u003eL\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003earound the lesser trochanter\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eB\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eBed of implant\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eB1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003earound the stem or just below it, stable stem\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003earound the stem or just below it, loose stem, good bone-stock\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eburst\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003ecomminution, more frequent in cemented stem\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eclamshell\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003edisplaced fracture of medial cortex including residual neck, calcar and lesser trochanter, stem stable or loose, more frequent in uncemented stem\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003ereverse clamshell\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003edisplaced fracture of lateral cortex with a \u0026ldquo;reverse obliquity\u0026rdquo; pattern, stem loose\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003espiral\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003emore frequent in cemented stem\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eB3\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003earound the stem or just below it, loose stem, poor bone-stock\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eC\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eClear of the implant\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003ewell below the prosthesis\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\u003e \n\n\u003cp\u003e\u003cstrong\u003eTable 2. Proposed treatment for PFF according to modified Vancouver classification.\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabb\" border=\"1\"\u003e \u003ccolgroup cols=\"8\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eTreatment of PFFs according to Vancouver types \u0026amp; subtypes\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eApophyseal\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003csub\u003eG\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003csub\u003eGU\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eundisplaced\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003econservative\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003csub\u003eGD\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003edisplaced\u0026thinsp;\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u0026ge;\u003c/span\u003e\u0026thinsp;2\u0026nbsp;cm\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eosteosynthesis\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eA\u003csub\u003eL\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003econservative\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eB\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eBed of implant\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eB1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB1\u003csub\u003eU\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eundisplaced\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003econservative or osteosynthesis\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eB1\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB1\u003csub\u003eD\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003edisplaced\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eosteosynthesis\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB1\u003csub\u003eC\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eat the tip of a cemented stem\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003erevision or osteosynthesis\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003csub\u003eB\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eburst\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003erevision\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003csub\u003eCS\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eclamshell, stable stem*\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003econservative or osteosynthesis\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003csub\u003eCL\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003eclamshell, loose stem\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003erevision\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003csub\u003eRS\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003ereverse clamshell, stable stem*\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003econservative, osteosynthesis or revision\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003csub\u003eRL\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003ereverse clamshell, loose stem\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003erevision\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eB2\u003csub\u003eS\u003c/sub\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cdiv class=\"SimplePara\"\u003espiral\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003erevision\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eB3\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003erevision\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eC\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eClear of the implant\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e \u003cdiv class=\"SimplePara\"\u003eosteosynthesis\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003e* being the stem stable, they should not probably be considered as B2 PFFs and should be moved into B1 PFFs\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\u003e \n\n\u003cp\u003e\u003cstrong\u003eTable 3. Suggested “short” phosphocalcic metabolic panel, including only blood testing without any precise preparation nor a 24-hours urine collection. ALP: alkaline phosphatase, Ca: calcium, P: phosphorus, PTH: Parathormone, CTX: C‐telopeptide of type I collagen, P1NP: aminoterminal pro-peptide of type I procollagen, 25(OH)D: cholecalciferol (vitamin D3).\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabc\" border=\"1\"\u003e \u003ccolgroup cols=\"1\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eSuggested \u0026ldquo;short\u0026rdquo; panel for phosphocalcic metabolism\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eALP, U/L (range 55\u0026ndash;142)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCa, mg/dL (range 8.9\u0026ndash;10.1)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eP, mg/dL (range 2.5\u0026ndash;4.5)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003ePTH, pg/mL (range 15\u0026ndash;65)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCTX, ng/L (range 100\u0026ndash;700 over 50\u0026nbsp;years)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eP1NP, \u0026micro;g/L (range 15\u0026ndash;75 over 50\u0026nbsp;years)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003e25(OH)D, ng/mL (range 30\u0026ndash;100)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eCreatinine, mg/dL (range 0.6\u0026ndash;1.1)\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\u003e \n\n\n\u003cp\u003e\u003cstrong\u003eTable 4. Criteria used in the proposed therapeutic algorithm. Mechanical criteria can be major or minor, biological criteria can be local or systemic.\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"No\" id=\"Tabd\" border=\"1\"\u003e \u003ccolgroup cols=\"4\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eMechanical criteria\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eBiological criteria\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003emajor\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eminor\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003elocal\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003esystemic\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003edeficient medial cortex\u003csup\u003e^\u003c/sup\u003e\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003etransverse fracture\u003c/div\u003e \u003cdiv class=\"SimplePara\"\u003eat the tip of a stem\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003efracture around a cemented stem\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003ediseases affecting phosphocalcic metabolism\u003csup\u003e\u0026sect;\u003c/sup\u003e\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003einability to guarantee an adequate fixation around the stem with only the plate\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003efracture comminution\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eestimated wide surgical dissection or a previous open access at the affected site\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003elong lasting pharmacological therapies with CCSs or BPs\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003epoorness of bone-stock\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eatypical pattern of the fracture\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cdiv class=\"SimplePara\"\u003eheavy smoking\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003e^\u003c/sup\u003e resorption, wedge fracture or comminution\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003e\u0026sect;\u003c/sup\u003e osteoporosis, rheumatic and/or autoimmune diseases, primary or secondary endocrinological diseases, osteomalacia, Paget\u0026rsquo;s disease, ..\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"periprosthetic femoral fracture, Vancouver B1, Vancouver C, therapeutic algorithm, Teriparatide, re-fracture, nonunion, non-union, bone marrow concentrate, stable stem, structural allograft","lastPublishedDoi":"10.21203/rs.3.rs-38837/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-38837/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: There is lack of consensus regarding best operative fixation strategy for periprosthetic femoral fractures (PFFs) around a stable stem. Based on our experience in the treatment of nonunions after PFFs and other challenging cases and on Literature, we propose an algorithm that can guide in choosing the ideal surgical technique even for first-time PFFs with a stable stem.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: We retrospectively reviewed data on patients who failed to heal after a surgically treated Vancouver type B1 or C PFF. All patients were treated with locking plate, double structural allograft and autologous bone marrow concentrate (BMC) over a platelet-rich plasma (PRP)-based membrane at fracture site. All patients were also pharmacologically treated with Teriparatide in the postoperative period. We studied patients with radiograms, histological evaluation of the nonunion area, and phosphocalcic metabolism. Patients were assessed subjectively, clinically and radiographically until healing and then annually.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: All nonunions healed over a six months period, and functional recovery appeared to be good. Retrospective evaluation of the proposed algorithm showed that none of the patients met biological or mechanical criteria such as to make valid the treatment with locking plate alone.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: Mechanical factors are not the only issues that should be taken into account when choosing the surgical approach to PFFs over a stable stem. Systemic and local biological conditions are factors that should drive to a rigid fixation with absolute stability (using a plate and structural allograft) plus local biological support (structural allograft and autologous BMC in a PRP-based scaffold) and systemic anabolic treatment (Teriparatide) in the first instance. A therapeutic algorithm is proposed, given the prosthetic stem to be stable, taking into account mechanical and biological criteria.\u003c/p\u003e","manuscriptTitle":"Combined Surgical And Medical Treatment For Periprosthetic Femoral Fractures Over A Stable Stem (Vancouver Type B1 And C): A Proposal Of A Therapeutic Algorithm To Reduce The Risk Of Nonunion.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2020-07-14 17:02:12","doi":"10.21203/rs.3.rs-38837/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b512ebfd-e7ac-42b9-a629-4f61dce5f1cd","owner":[],"postedDate":"July 14th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":151916,"name":"Orthopedics"}],"tags":[],"updatedAt":"2020-10-07T11:38:41+00:00","versionOfRecord":[],"versionCreatedAt":"2020-07-14 17:02:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-38837","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-38837","identity":"rs-38837","version":["v1"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}