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  Table of Contents  
Year : 2019  |  Volume : 37  |  Issue : 4  |  Page : 531-535

Is it safe to do a single-stage implant exit and primary hip replacement? clinical and microbiological profiling

1 Department of Orthopaedics, Christian Medical College, Vellore, Tamil Nadu, India
2 Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India

Date of Submission31-Jan-2020
Date of Acceptance09-Apr-2020
Date of Web Publication18-May-2020

Correspondence Address:
Dr. T D Hariharan
Department of Orthopaedics, Christian Medical College, Vellore - 632 004, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijmm.IJMM_20_40

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 ~ Abstract 

Background: A single-stage implant revision for failed fixation of proximal femoral fractures is performed only when there is no evidence of infection. Else, a two-staged revision is preferred - where the definitive revision surgery is done a few months after the implant exit. This study aims to audit the safety and incidence of culture positivity in single-stage revisions. Materials and Methods: Forty one of 284 patients that presented over the last 12 years for implant exchange of the hip, had a single stage revision surgery for failed fixation of a fracture of the hip, as there was no obvious evidence of infection at the time of implant exit. Results: Micro-organisms were grown in 51% of the 41 hips. 76% were gram positive, of which 63% were Coagulase negative staphylococci (CoNS). 50% of CoNS and 75% of S. aureus were resistant to oxacillin, but susceptible to Vancomycin. Of the gram negative organisms, 2 (Enterobacter sp) were resistant to carbapenam, while others were susceptible. Preoperative ESR and CRP, individually, had low specificity – 50% for ESR >30mm at 1 hour and 62% for CRP>10. The combined use of ESR > 30mm and CRP>10 increased the specificity to 90%. 12% of the patients had immediate postoperative complications that required a wash out in theatre. The long term clinical follow up of these patients is limited. Conclusion: This study suggests that implant exit and simultaneous arthroplasty for failed fracture fixation should be done with caution due to the high possibility of infection. It may be prudent to opt for a 2 stage revision.

Keywords: Failed fracture fixation. hip infection, hip replacement, implant exit, microbiological profile

How to cite this article:
George R, Hariharan T D, Arunshankar A, Elangovan D, Lal B, Chandy V J, Oommen A T, Poonnoose PM. Is it safe to do a single-stage implant exit and primary hip replacement? clinical and microbiological profiling. Indian J Med Microbiol 2019;37:531-5

How to cite this URL:
George R, Hariharan T D, Arunshankar A, Elangovan D, Lal B, Chandy V J, Oommen A T, Poonnoose PM. Is it safe to do a single-stage implant exit and primary hip replacement? clinical and microbiological profiling. Indian J Med Microbiol [serial online] 2019 [cited 2020 Sep 30];37:531-5. Available from:

 ~ Introduction Top

There are a large number of patients undergoing surgeries for fractures around the hip. Unfortunately, fixations of these fractures occasionally fail.[1],[2] Total hip arthroplasty is often indicated for patients who have had failed conservative or previous surgical treatment for a fractured hip joint. Occasionally, the revision of the fixation device or removal of the implant may help in relieving the pain. There is always a worry whether it is safer to revise the implant in a single-stage procedure or whether to do it as a two-stage procedure, that is, implant removal at the first stage, followed by a second-stage arthroplasty following a period of antibiotic therapy.[3] This stems from the fear that the implants could potentially be infected and could lead to infection.[4] For cases where there is an obvious infection, a two-stage exchange, arthroplasty is the preferred treatment of choice, with high infection eradication rates of 90% and successful outcomes.[5],[6]

There are consensus guidelines on the role of single- and two-stage revision arthroplasty in prosthetic joint infections (PJI).[7],[8] In PJI, single-stage arthroplasty is performed when the organism is non-virulent and sensitive to first-line antibiotics. Two-stage revision is advised in the presence of a sinus or when the infecting organisms not known or if it is multidrug resistant.[9],[10] However, there is little literature/guidelines on the safety of performing arthroplasty after failed trauma surgeries around the hip. While some surgeons prefer to do the surgery in two stages, most surgeons perform arthroplasty at the same time as the implant exit, that is, as a single-stage surgery. However, the incidence of infection/colonisation of the implant is not known. The outcome of a single-stage arthroplasty in such single-stage revisions is also not documented. The aim of this study was to study the microbiological profile of organisms isolated from the hip implants and to assess the safety and efficacy of a single-stage revision arthroplasty for failed fracture fixation around the hip joint.

 ~ Materials and Methods Top

All patients who presented with failed fracture fixations around the hip that required implant exchange or arthroplasty during the period 2008–2019 were included in the study. Patients who presented with a history or signs suggestive of infection were excluded from the study. If at the time of surgery, there were obvious signs of infection/increased granulation tissue, a two-stage procedure was performed, where the implant was removed at the first stage, and arthroplasty was performed later after a period of antibiotic therapy. Such patients were also excluded from the analysis. Patients who had revision hip surgery for a loose/infected hip arthroplasty were also excluded. Only failed fracture fixation with no pre-operative or perioperative suggestion of infection was included in the study [Figure 1]. For such patients, a single-stage arthroplasty/implant exchange was performed if there was no overt evidence of infection at the time of implant removal. Occasionally, if the primary surgery to remove the implant took an inordinate amount of time, a decision was made perioperatively by the surgeon to opt for a two-stage arthroplasty. Tissue from around the implant was sent for routine culture. Data from the hospital records were reviewed to assess the microbiological profile and antibiotic susceptibility pattern of the organisms that were isolated. All patients received prophylactic vancomycin/teicoplanin for 5 days, which was converted to culture-specific antibiotics for 4–6 weeks if organisms were cultured from the surgical site.
Figure 1: Flowchart summarising patient selection

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 ~ Results Top

During the study, 284 patients presented with implants around the hip that required a revision/implant exit. However, only 41 patients who had a revision of a failed hip fixation for implants that were considered 'not infected', as per the inclusion criteria were enrolled in the study. The type of implant used for the primary fixation in these 41 patients is shown in [Figure 2]. In 22 patients, the implant was removed, and a primary arthroplasty was performed. In two patients with failed fixation of fracture neck of femur, the cancellous screws were removed, and valgus osteotomy was performed. In one patient, the dynamic hip screw (DHS) implant was exchanged for a proximal femoral nail (PFN). In seven patients, the implant was removed, and it was decided not to proceed with a new implant/prosthesis, as the hip joint was not damaged. In nine patients, the surgeon opted to do the surgery as a two-stage procedure, as the primary surgery to remove the implant took a considerable period of time. An arthroplasty was performed for them at the second stage. In 95% (39) of the patients, the implants were removed as part of the initial debridement, but in two patients who had arthroplasty for acetabular fracture sequelae, some of the acetabular plates and screws were not removed at the time of arthroplasty, as they were difficult to access but did not come in the way of the cup or screw placement.
Figure 2: Implants removed at primary stage

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The median preoperative erythrocyte sedimentation rate (ESR) was 36 mm at 1 h (interquartile range [IQR]: 23–50), and C-reactive protein (CRP) was 9.7 (IQR: 5.09–15.87). and 14 (34%) had a CRP >10, while 9 (22%) had an ESR >50 mm at 1 h. 8 (20%) % had both CRP >10 and ESR >30 mm at 1 h. [Table 1] shows the specificity, sensitivity, negative and positive predictive values of ESR >30 mm, ESR >50 mm, CRP >10 and a combined ESR >30 mm and CRP >10.
Table 1: Specificity, sensitivity and predictive values of biochemical markers

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Microorganisms were identified in 21 of the 41 (51%) cases that had implant exit [Figure 3]. All 21 patients had monomicrobial infection. Gram-positive cocci (76%) included Coagulase-negative staphylococci (CoNS) (n = 10), Staphylococcus aureus (n = 4) and Enterococcus species, (n = 2). The antimicrobial susceptibility profile of these organisms is represented in [Figure 4]. Fifty percent of CoNS and 75% of S. aureus were resistant to oxacillin. All oxacillin-resistant CoNS and S. aureus were susceptible to vancomycin.
Figure 3: Micro-organisms profile

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Figure 4: Antimicrobial susceptibility profile of gram-positive organisms

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Among the smaller subgroup of Gram-negative organisms (n = 5), the Escherichia coli strains (n = 2) were identified as extended-spectrum beta-lactamase (ESBL) producers and were susceptible to piperacillin-tazobactam, amikacin and carbapenems. Enterobacter sp. (n = 2) was characterised as ESBL producers and resistant to carbapenem. The single Pseudomonas sp. isolated was found to be susceptible to all the tested antibiotics (cefpodoxime, piperacillin-tazobactam, cefoperazone-sulbactam, amikacin, tobramycin, levofloxacin and carbapenem).

Of the 11 patients that had cancellous screws, 6 (55%) were culture positive, whereas 14/20 (70%) of DHS/PFN were culture positive, and 1 (17%) of 6 acetabular implants was culture positive. Of the 41 patients that had the surgery, 5 (12%) patients had immediate post-operative complications that required a washout. Two hips required a washout for a collection following DHS exit, while two were following PFN exit. Another hip required washout following cancellous screw removal and hip arthroplasty. In four of the five hips, organisms were cultured at the time of the implant exit.

The long-term follow-up of these patients was poor, with only 23 (56%) having a follow-up of ≥6 months. Fourteen (34%) had a mean follow-up of 1 year, and only seven (17%) had a follow-up of ≥2 years. At the time of the last follow-up, there was no clinical evidence of infection, and X-rays did not show any loosening of implant or failure of fixation.

 ~ Discussion Top

Failure of fixation of fragility fractures of the hip is seen in 5% of peritrochanteric fractures, and in 15%–40% of fractures of the femoral neck.[1] This often necessitates the removal of the old implant and revision to another implant or revision arthroplasty. While there are several long-term studies that have documented the success of revision of a failed implant to another fixation device,[10] there is little information on the complications and infection rates when arthroplasty is done following the implant exit as a single-stage surgery.

In any revision arthroplasty surgery for a loose prosthesis, the infection has to be ruled out before inserting a new prosthesis. There are definitive criteria that help guide the choice of single-stage or two-stage revision for peri-PJI, based on the Musculoskeletal Infection Society (MSIS) consensus of 2013.[11] Any patient with one major criterion or three out of five minor criteria is considered positive for prosthetic infection. The two major criteria include (a) a sinus tract communicating with the prosthesis and (b) a pathogen isolated by culture from two separate tissue or fluid samples obtained from the affected prosthetic joint. Minor criteria include a) elevated serum ESR (> 30 mm/h) and CRP levels (>10 mg/L), (b) elevated synovial fluid white blood cells count (>3,000 cells/ml), (c) elevated synovial neutrophils percentage (80%), (d) isolation of a microorganism in one culture of periprosthetic tissue or fluid and (e) >5 neutrophils per high-power field in five high-power fields observed for histologic analysis of periprosthetic tissue at ×400. The consensus group further states that PJI may be present without meeting these criteria, specifically in the case of less virulent organisms (e.g., Propionibacterium acnes). Thus, the clinicians are urged to exercise their judgment and clinical acumen in reaching the diagnosis of PJI.[11]

Where the criteria are negative, a single-stage revision is performed. However, in Tsukayamma's review, there were several unexpected positive cultures in hips that were considered to be aseptic at the time of a single-stage revision.[12] These infections have been classified as type IV infections as per the classification by Fitzgerald et al.[13] It is possible that several of the prosthesis had subclinical infections due to biofilm formation over the original implant, and therefore, infected the newly implanted prosthesis. The current recommendation is that these patients are treated with 6 weeks of culture-specific intravenous antibiotics.[11]

While there is more consensus on the management of aseptic and septic revision arthroplasty, the best strategy to manage the revision of failed trauma implants is not clear. In situ ations where there is an obvious infection, a two-stage arthroplasty may be preferred to reduce the chances of a failed arthroplasty surgery. Where the preliminary investigations are negative for infection, and there is no perioperative clinical evidence of infection, a single-stage revision surgery is often performed. However, there is little literature on the success of such as single-stage revision surgery for failed fixation of fractures around the hip.[14]

This study seems to suggest that ESR and CRP individually are not of much value as a screening test for infection. The specificity of both ESR and CRP are not good enough to be a screening tool. Increasing the ESR cut off to >50 mm at 1 h increases the specificity to about 80%. The combination of ESR >30 mm at 1 h and CRP >10 further increases the specificity to 90%. These results are quite similar to those seen in infected arthroplasty exchanges. According to the MSIS criteria, joint aspiration is an important screening tool to rule out the possibility of an infected prosthesis. However, in the failed fracture fixation situation, often there is no joint fluid to aspirate, and hence criteria using joint aspiration results have a limited role.

It has been reported, that in situ ations where there is no clinical suspicion of infection before operation, and intraoperative frozen sections show <5 polymorphonuclear leukocytes per high-power field, re-implantation may be carried out in a single stage, with a 91% chance of absence of infection.[15] When more than 5 polymorphonuclear leukocytes per high-power field are seen in the frozen sections, it would be prudent to defer re-implantation until a later stage. In this study, frozen sections were not sent routinely, and it's usefulness has not been studied. However, there are other studies that seem to suggest that the frozen section is not specific enough for the diagnosis of infection.[16]

In this study, 51% of the implants removed were culture positive. The size of the implant did not seem to affect the rate of infection. Fifty-five percent of cancellous screws had positive cultures, while 70% of the PFN/DHS were infected. It is possible that the culture yield may have been higher if sonication of the implants was done. However, the high rate of positive cultures seen in the revision surgery is of concern.

The long-term outcome of these single-stage revisions is not clear, as the follow-up for the patients is poor in this study. However, 12% had immediate post-operative complications that required washout, and it can be postulated that the long-term complications may have been even more, considering the fact that the follow-up of these patients was not optimal. Long-term follow-up of these patients is essential to comment on the long-term safety of the single-stage revision surgery.

With 51% of the cultures being positive, one has to be cautious about a single-stage implant exchange and revision arthroplasty. The standard prophylaxis used in arthroplasty as per the international guidelines is injection cefazolin/cefuroxime. However, if we use this empirical antibiotic therapy for the initial 2 or 3 days until culture and susceptibility reports are available, we may actually be using inappropriate antibiotic cover during the immediate post-operative period. This can result in the failure of the revision surgery. The cultures in this study seem to suggest that most of the organisms are either methicillin-resistant organisms or ESBL producers. Hence, in the absence of a pre-operative culture, it may be prudent to start the patient on vancomycin and carbapenem empirical therapy till culture results arrive.

McLawhorn et al. seem to suggest that the outcome of single-stage arthroplasty in culture-negative cases could be as bad as the culture-positive cases.[17] In our earlier study of infected hip arthroplasty, it was seen that 36% of the cases were culture negative at presentation even though they were considered infective by the MSIS criteria.[3] The negative culture report should hence be viewed as a failure of the sampling technique rather than as the absence of infection. It may be argued the organism cultured may have been a contaminant, as two separate culture samples were not sent from the surgical site in all cases. If better diagnostic tools are available to exclude infection at the time of the implant exit, we may be able to reduce the incidence of complications associated with this single-stage procedure.

 ~ Conclusion Top

This study suggests that implant exit and simultaneous arthroplasty for failed fracture fixation should be done with caution. There is a high possibility of infection and biofilm formation in the implanted prosthesis. It may be prudent to avoid a single-stage procedure and opt for a two-stage revision. While ESR and CRP have a limited role for screening for infection, a per-operative frozen section may provide valuable information that may be able to guide the surgeon intraoperatively. However, this is to be studied in more depth. Knowledge of the behavior and biofilm-forming capability of organisms will give us the ability to prognosticate the outcome and refrain from making unrealistic promises to the patient.

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Conflicts of interest

There are no conflicts of interest.

 ~ References Top

Broderick JM, Bruce-Brand R, Stanley E, Mulhall KJ. Osteoporotic hip fractures: The burden of fixation failure. ScientificWorldJournal 2013;2013:515197.  Back to cited text no. 1
Mingli F, Huiliang S, Guanglei C, Zheng L, Shibao L, Limin L, et al. A clinical study on arthroplasty for failed internal fixation of hip fractures and review of literature. Pak J Med Sci 2017;33:798-803.  Back to cited text no. 2
Hariharan TD, Chandy VJ, George J, Mathew AJ, Premnath J, Pragasam AK, et al. Microbiological profile and outcomes of two-stage revision hip arthroplasty. Indian J Med Microbiol 2019;37:67-71.  Back to cited text no. 3
[PUBMED]  [Full text]  
Cooper HJ, Della Valle CJ. The two-stage standard in revision total hip replacement. Bone Joint J 2013;95-B:84-7.  Back to cited text no. 4
Chen SY, Hu CC, Chen CC, Chang YH, Hsieh PH. Two-stage revision arthroplasty for periprosthetic hip infection: Mean follow-up of ten years. Biomed Res Int 2015;2015:345475.  Back to cited text no. 5
Ibrahim MS, Khan MA, Nizam I, Haddad FS. Peri-operative interventions producing better functional outcomes and enhanced recovery following total hip and knee arthroplasty: An evidence-based review. BMC Med 2013;11:37.  Back to cited text no. 6
Charette RS, Melnic CM. Two-stage revision arthroplasty for the treatment of prosthetic joint infection. Curr Rev Musculoskelet Med 2018;11:332-40.  Back to cited text no. 7
Kunutsor SK, Beswick AD, Whitehouse MR, Blom AW. One- and two-stage surgical revision of infected elbow prostheses following total joint replacement: A systematic review. BMC Musculoskelet Disord 2019;20:467.  Back to cited text no. 8
Wang Q, Goswami K, Kuo FC, Xu C, Tan TL, Parvizi J. Two-stage exchange arthroplasty for periprosthetic joint infection: The rate and reason for the attrition after the first stage. J Arthroplasty 2019;34:2749-56.  Back to cited text no. 9
Luthringer TA, Elbuluk AM, Behery OA, Cizmic Z, Deshmukh AJ. Salvage of failed internal fixation of intertrochanteric hip fractures: Clinical and functional outcomes of total hip arthroplasty versus hemiarthroplasty. Arthroplast Today 2018;4:383-91.  Back to cited text no. 10
Parvizi J, Gehrke T, Chen AF. Proceedings of the international consensus on periprosthetic joint infection. Bone Joint J 2013;95-B:1450-2.  Back to cited text no. 11
Tsukayama DT, Estrada R, Gustilo RB. Infection after total hip arthroplasty. A study of the treatment of one hundred and six infections. J Bone Joint Surg Am 1996;78:512-23.  Back to cited text no. 12
Fitzgerald RH Jr., Nolan DR, Ilstrup DM, Van Scoy RE, Washington JA 2nd, Coventry MB. Deep wound sepsis following total hip arthroplasty. J Bone Joint Surg Am 1977;59:847-55.  Back to cited text no. 13
Srivastav S, Mittal V, Agarwal S. Total hip arthroplasty following failed fixation of proximal hip fractures. Indian J Orthop 2008;42:279-86.  Back to cited text no. 14
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Bori G, Navarro G, Morata L, Fernández-Valencia JA, Soriano A, Gallart X. Preliminary results after changing from two-stage to one-stage revision arthroplasty protocol using cementless arthroplasty for chronic infected hip replacements. J Arthroplasty 2018;33:527-32.  Back to cited text no. 15
Tsaras G, Maduka-Ezeh A, Inwards CY, Mabry T, Erwin PJ, Murad MH, et al. Utility of intraoperative frozen section histopathology in the diagnosis of periprosthetic joint infection: A systematic review and meta-analysis. J Bone Joint Surg Am 2012;94:1700-11.  Back to cited text no. 16
McLawhorn AS, Nawabi DH, Ranawat AS. Management of resistant, atypical and culture-negative periprosthetic joint infections after hip and knee arthroplasty. Open Orthop J 2016;10:615-32.  Back to cited text no. 17


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

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