When a 40-year-old man arrived at Valdoltra Orthopaedic Hospital in Slovenia in 2021, his left hip had already been through eight operations. A severe acetabular fracture sustained in a polytrauma had been treated with osteosynthesis elsewhere, the hardware had failed, and a cascade of further surgeries had left him with a chronic, draining infection and a leg 15 centimeters shorter than the other. A fist-sized sinus tract opened on the lateral side of his hip, communicating all the way down to the acetabulum, and imaging showed extensive heterotopic ossification together with the aftermath of a resection of the proximal femur and greater trochanter. His C-reactive protein, a standard marker of systemic inflammation, stood at 12.8 milligrams per liter. What followed, described in a case report published in the Journal of Bone and Joint Infection, was a meticulously staged salvage effort that combined repeated surgical debridement, antibiotic-loaded cement spacers, a rotating regimen of intravenous drugs, and an unusual addition: antibiotics infused directly into the joint space through a catheter.
The microbes recovered from his hip were among the most feared organisms in modern medicine. Of nine intraoperative tissue samples, eight grew carbapenem-resistant, carbapenemase-producing Acinetobacter baumannii, and two grew OXA-48-producing carbapenem-resistant Klebsiella pneumoniae. Alongside these Gram-negative threats, the cultures also yielded methicillin-resistant Corynebacterium amycolatum, Corynebacterium striatum, Staphylococcus epidermidis, and Enterococcus faecalis. In other words, the infection was polymicrobial and multidrug-resistant, involving bacteria for which carbapenems, usually considered the last-line class for Gram-negative infections, no longer worked. Reports of such organisms causing periprosthetic joint infection are rare, and treatment options are correspondingly scarce, which is precisely why the surgical team chose to document every step of their protocol.
The underlying difficulty in any implant-related bone and joint infection is the biofilm. Bacteria attached to an implant surface or to dead bone encase themselves in a protective matrix that acts as a physical barrier against antibiotics and immune cells. For many species, the concentration of drug needed to eradicate bacteria in a biofilm, the minimal biofilm eradication concentration, can be up to one thousand times higher than the concentration that kills the same bacteria floating freely in a laboratory culture. Systemic antibiotics alone therefore often fail, and the only reliable route to cure is meticulous surgical removal of infected tissue and foreign material, combined with antimicrobial therapy that reaches the joint in sufficient quantities. Periprosthetic joint infection of the hip occurs in roughly 0.5 to 2 percent of primary total hip replacements and up to 15 percent of revision procedures, and the stakes are high: failed treatment can end in amputation, a catastrophic functional outcome that surgeons strive to avoid.
The Slovenian team, led by Urban Vadnjal together with Samo Roškar, René Mihalič, Mitja Rak, and Rihard Trebše, followed a written institutional algorithm for fracture-related and periprosthetic joint infection, and the case report emphasizes that strict adherence to each step was central to the outcome. The first operation involved radical debridement of the infected hip and insertion of a temporary antibiotic-loaded cement spacer. Four 42.9-gram sachets of bone cement preloaded with gentamicin and clindamycin were supplemented with an additional 4 grams of vancomycin and 2 grams of meropenem, so that the spacer itself became a local drug-delivery depot occupying the dead space left after debridement. Nine microbiological and three histological samples were taken before any empirical antibiotics were started, allowing therapy to be tailored to the actual pathogens rather than guessed at.
Empirical treatment began immediately after sampling with intravenous piperacillin-tazobactam and vancomycin, the latter dosed by plasma concentration monitoring. Once the antibiograms of the isolated bacteria returned, therapy was escalated on the third postoperative day to a combination of vancomycin, fosfomycin, and colistin, a polymyxin reserved for the most resistant Gram-negative infections, given as a 9-million-unit loading dose followed by 4.5 million units every twelve hours. Crucially, the team also began intra-articular infusions: 400 milligrams of vancomycin in 5 milliliters every twenty-four hours, and 125,000 international units of colistin in 2 milliliters daily, delivered through a catheter placed in the joint. The pharmacy department designed these preparations based on the physicochemical properties and cytotoxicity profiles of the drugs, and on measured concentrations in drainage fluid, aiming for the smallest possible volume in which each antibiotic remained fully soluble.
The regimen was then refined repeatedly as definitive resistance data arrived. Fosfomycin was stopped one week after surgery when the laboratory confirmed resistance, and intravenous tigecycline was introduced instead. Two weeks postoperatively, vancomycin and tigecycline were withdrawn and replaced with teicoplanin and ceftazidime-avibactam, a beta-lactam and beta-lactamase-inhibitor pair active against some carbapenem-resistant Enterobacterales. At eighteen days, with the full resistance profile in hand, the team settled on a final targeted combination: intravenous ceftazidime-avibactam to cover the Klebsiella pneumoniae, dose-adjusted intravenous vancomycin to cover the Gram-positive organisms, and continued daily intra-articular colistin against the Acinetobacter baumannii. All intravenous and local therapy was stopped at three weeks, by which time the C-reactive protein had fallen below 5 milligrams per liter and the catheter was removed under a watertight seal protocol with regular dressing changes.
What followed was a deliberate antibiotic holiday of two weeks, after which a second revision procedure in January 2022 allowed the team to test whether the infection had truly been suppressed. Debridement and tissue sampling were repeated, and the spacer was exchanged for a new one made from three sachets of gentamicin- and clindamycin-loaded cement supplemented with 3 grams of vancomycin and 3 million units of colistin. A short seven-day course of intravenous vancomycin, ceftazidime-avibactam, and intra-articular colistin accompanied the exchange. This time the cultures came back sterile, and histology showed no evidence of acute inflammation, the biological green light the team needed to proceed to definitive reconstruction.
At the end of February 2022, the hip was rebuilt with trabecular metal augments, a dual-mobility acetabular shell, and a cementless femoral component, supported by a brief five-day course of intravenous vancomycin and ceftazidime-avibactam. Because no susceptible oral antibiotic existed for any of the pathogens involved, the entire treatment course was administered parenterally, a demanding logistical undertaking that required regular monitoring of serum creatinine, urea, and electrolytes to guard against kidney toxicity, particularly from the colistin and the glycopeptides. The patient left hospital walking with crutches, the surgical wound fully healed.
At the most recent follow-up in June 2026, three and a half years after the reconstruction, there were no clinical or laboratory signs of infection. The patient walked without assistive devices over shorter distances, had good hip mobility and strength, and reported no pain at rest with only mild discomfort on exertion. His Harris hip score was 78, with the main functional limitation being a foot drop and Achilles tendon contracture dating back to the original polytrauma rather than the infection. Radiographs showed a stable implant with no osteolysis, loosening, or periprosthetic fracture, and the residual limb length discrepancy was approximately 2 centimeters.
The authors are careful about what the case can and cannot prove. A single patient cannot isolate the contribution of intra-articular antibiotics from the many other moving parts: extensive debridement, multiple revision procedures, spacer exchange, systemic combination therapy, and multidisciplinary management all plausibly contributed. Local drug delivery is attractive in principle because it sidesteps systemic toxicity, poor perfusion of scarred tissue, and a blunted immune response around the infected joint, and the approach was first described in the early 1990s and popularized in 2017 as a way of treating infected hip replacements. But the team frames it as a salvage option to be considered alongside, not instead of, rigorous surgery. Their broader message is procedural rather than pharmacological: hospitals treating fracture-related and periprosthetic infections need well-established algorithms and the discipline to follow them at every step, because in severe multidrug-resistant cases a multiple-stage protocol, with intra-articular infusions added to standard intravenous regimens, may be what stands between a patient and a dead-end outcome.
Subject of Research: Treatment of a polymicrobial, multidrug-resistant chronic hip infection with staged revision surgery and combined systemic and intra-articular antibiotic therapy
Article Title: Clinical case of polymicrobial and multidrug-resistant posttraumatic chronic hip infection treatment
Article References: Vadnjal, U., Roškar, S., Mihalič, R., Rak, M., & Trebše, R. (2026). Clinical case of polymicrobial and multidrug-resistant posttraumatic chronic hip infection treatment. Journal of Bone and Joint Infection, 11(5), 565-568. https://doi.org/10.5194/jbji-11-565-2026
Image Credits: AI Generated
Keywords: periprosthetic joint infection, fracture-related infection, multidrug-resistant bacteria, carbapenem-resistant Acinetobacter baumannii, Klebsiella pneumoniae, biofilm, intra-articular antibiotics, antibiotic-loaded cement spacer, hip revision surgery, colistin, ceftazidime-avibactam, antimicrobial resistance
News Source: Ophelia Keating. (October 8, 2026). Surgeons Beat a Drug-Resistant Hip Infection With Staged Surgery and Antibiotics Delivered Straight Into the Joint. Scienmag.
