Two-Stage Exchange for PJI
Two-Stage Exchange Arthroplasty for Chronic Periprosthetic Hip and Knee Infection
Insall JN · J Bone Joint Surg Am · 1983
This foundational landmark study introduced the staged surgical protocol for infected total knee arthroplasty, demonstrating that thorough debridement and delayed reimplantation following parenterally administered targeted antibiotics could eradicate chronic infection while preserving a functional joint.
Citation & links
Insall JN, Thompson FM, Brause BD. Two-stage reimplantation for the salvage of infected total knee arthroplasty. J Bone Joint Surg Am. 1983 Oct;65(8):1087-98.
Key findings
- 1.Complete eradication of infection without recurrence was achieved in 10 of the 11 patients (91% microbiological success rate) at a mean follow-up of 34 months.
- 2.A single patient experienced reinfection with a differing organism, which resolved successfully following subsequent knee arthrodesis.
- 3.Post-reimplantation functional outcomes were rated good or excellent in the majority of patients according to Hospital for Special Surgery (HSS) knee scoring metrics.
- 4.Mean postoperative active range of flexion after second-stage reimplantation reached approximately 90 degrees.
- 5.No cases of secondary aseptic loosening or gross mechanical failure were identified at intermediate-term follow-up.
- 6.The prolonged delay and prolonged systemic antibiotic therapy (minimum 6 weeks) eliminated the active pathogen load prior to the introduction of new foreign material.
Background
Prior to this publication in 1983, prosthetic joint infection (PJI) following total knee arthroplasty carried catastrophic implications, routinely culminating in chronic sinus formation, permanent resection arthroplasty, arthrodesis, or transfemoral amputation. Early single-stage revisions without prolonged pathogen-directed clearance frequently succumbed to persistent or recurrent biofilm-associated sepsis. John Insall and colleagues set out to evaluate whether a structured, delayed two-stage reimplantation protocol—coupling comprehensive aggressive surgical debridement with an extended course of culture-directed parenteral antimicrobial therapy—could achieve definitive microbiological cure alongside preservation of knee function.
Methods
This prospective observational case series followed 11 consecutive patients (treating 11 infected total knee replacements) managed at the Hospital for Special Surgery. The two-stage protocol involved: (1) explantation of all prosthetic components and acrylic bone cement combined with extensive synovectomy and debridement of infected soft tissues and bone; (2) targeted intravenous antimicrobial therapy administered for at least 6 weeks under infectious disease supervision; and (3) delayed reimplantation of a new knee prosthesis using antibiotic-impregnated polymethylmethacrylate (PMMA) cement once local soft tissues settled and systemic inflammatory parameters normalised. Patients were followed clinically and radiographically for an average of 34 months (range, 24 to 60 months).
Clinical implications
Insall et al.'s work established two-stage exchange arthroplasty as the historic international 'gold standard' for managing chronic periprosthetic knee joint infections, displacing routine salvage procedures such as resection arthroplasty and arthrodesis. Although subsequent iterations evolved to integrate temporary static or articulating antibiotic-impregnated polymethylmethacrylate spacers during the interim period (which were not part of Insall's original spacer-less protocol), the foundational principles—meticulous surgical debridement, implant and cement clearance, systemic antimicrobial holiday/monitoring, and reimplantation with antibiotic-laden cement—remain core tenets of adult reconstruction algorithms today.
Critical appraisal
This classic study defined modern PJI surgical protocols, but possesses typical limitations of early landmark surgical cohorts: it is a small (n=11), uncontrolled, single-centre case series without a comparative control group. Furthermore, the original technique did not utilise an interim antibiotic cement spacer; this absence commonly precipitated periarticular soft tissue retraction, quadriceps shortening, bone loss, and extensive extensor mechanism scarring that complicated exposure during second-stage reimplantation. In addition, diagnostic testing relied on historic laboratory criteria rather than contemporary International Consensus Meeting (ICM) or Musculoskeletal Infection Society (MSIS) definitions.
Teaching note
Every exit examination candidate in orthopaedics (FRCS, EBOT, FRACS, FRCSC) must cite Insall (1983) as the seminal paper describing the two-stage revision protocol for infected total knee replacements. Key exam distinction: Insall's original 1983 technique was a spacerless delayed reimplantation after 6 weeks of intravenous antibiotics. Later surgeons added temporary static blocks (e.g., Booth) and articulating spacers (e.g., PROSTALAC) to maintain collateral ligament tension, preserve tissue planes, and facilitate second-stage exposure.
Exam-tested points
- ›Seminal paper establishing the 2-stage exchange arthroplasty as the benchmark salvage technique for chronic PJI of the knee.
- ›Demonstrated an initial infection eradication rate exceeding 90% (10 out of 11 knees) at intermediate follow-up.
- ›Required complete removal of all prosthetic components and every fragment of PMMA cement, coupled with thorough radical synovectomy/debridement.
- ›Mandated an interim course of at least 6 weeks of targeted parenteral antibiotic therapy.
- ›Employed antibiotic-impregnated bone cement at the time of final component reimplantation.
- ›Original 1983 protocol was spacerless; candidates must note that modern practice incorporates static or articulating PMMA spacers to avoid joint contracture, soft-tissue collapse, and patellar tendon shortening.
- ›Common viva pearl: compare Insall's two-stage protocol with the contemporary Endo-Klinik / Buchholz philosophy of single-stage revision for knee PJI.
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