Muscle-Sparing Hip Surgery Route Proves Safe for Two-Stage Infection Revision

When a total hip replacement becomes chronically infected, surgeons face one of the most daunting challenges in orthopedic surgery: eradicating bacteria that have colonized the implants and surrounding bone while preserving enough muscle and soft tissue to allow the joint to function again. A new study from the Orthopedic Hospital Vienna Speising in Austria now provides some of the first detailed evidence that this delicate balancing act can be achieved through the direct anterior approach, a muscle-sparing surgical route that has surged in popularity for primary hip replacement but has remained controversial for revision surgery. The findings, published in the Journal of Bone and Joint Infection, suggest that the technique delivers reinfection and complication rates that compare favorably with the traditional approaches long favored for these complex procedures.

The research team, led by Sebastian Simon and corresponding author Jochen G. Hofstaetter, combed through a prospectively maintained institutional arthroplasty registry covering 8,476 primary total hip arthroplasties performed through the direct anterior approach between 2013 and 2024. Within this cohort, they identified 36 patients, or 0.4 percent, who developed a chronic periprosthetic joint infection, defined as an infection occurring more than four weeks after the index operation, and subsequently underwent a two-stage septic revision in which both stages were performed through the same anterior route. Diagnosis was standardized using the 2018 International Consensus Meeting criteria for periprosthetic joint infection, with 83.3 percent of patients scoring at or above the threshold of six that defines an infected joint.

The two-stage protocol remains the gold standard for chronic periprosthetic joint infection, and its logic is straightforward. In the first stage, all prosthetic components are removed, infected tissue is thoroughly debrided, and an antibiotic-loaded cement spacer is implanted to maintain joint space while delivering high local concentrations of antimicrobial drugs. Patients then receive systemic antibiotic therapy tailored to the organisms identified from tissue samples and implant sonication, continuing for a minimum of twelve weeks. Once clinical signs, inflammatory markers such as C-reactive protein, and microbiological parameters indicate that the infection is controlled, a second operation removes the spacer and implants a new prosthesis. The Vienna team performed reimplantation at least six weeks after the first stage, with the timing decided jointly with an infectious disease specialist based on the infecting organism, wound status, and laboratory trends.

The headline result is encouraging. After a median follow-up of 6.2 years, 28 of the 36 patients, or 77.8 percent, had undergone successful second-stage reimplantation and remained free of infection. Two additional patients, 5.6 percent, were deemed medically unfit for a second major operation and were treated definitively with a so-called 1.5-stage procedure, in which an articulating antibiotic-loaded permanent prosthesis was left in place; they too remained infection free. Among the 32 patients who actually received a new prosthesis, 87.5 percent stayed infection free, while four patients, 12.5 percent, developed recurrent infection requiring further septic revision. Two patients with persistent infection at the first stage ultimately required a Girdlestone procedure, a salvage operation that leaves the hip without a prosthesis. These reinfection figures fall squarely within the 8 to 32 percent range reported in the broader literature for two-stage hip revision, most of which has been generated using posterior or direct lateral approaches.

Just as important as the infection outcomes are the mechanical complications, and here the direct anterior approach showed distinct advantages. Spacer-related complications, a persistent worry in two-stage surgery, occurred in only two patients, 5.6 percent: one spacer dislocation and one spacer fracture, both in the subgroup receiving preformed spacers. Notably, none of the 25 patients who received custom-made antibiotic-loaded spacers experienced any spacer complication, an observation the authors attribute to the superior fit and stability of spacers fashioned intraoperatively from antibiotic-loaded cement. The overall spacer complication rate compares with a systematic review reporting mechanical spacer complications such as dislocation in roughly 10.8 percent of cases, and with spacer fracture rates of around 8 percent in prior series.

Dislocation after reimplantation is the other Achilles heel of two-stage hip revision, with published rates ranging from 9 to as high as 30 percent when posterior or direct lateral approaches are used. In the Vienna cohort, four patients experienced a dislocation after the second stage, and three of them, 8.3 percent, required surgical revision with head and liner exchange at a median of 22 days after reimplantation; the fourth was successfully managed with closed reduction. The authors suggest that the inherent stability of the direct anterior approach, which avoids cutting through the posterior soft-tissue sleeve that stabilizes the hip, may partly explain these low rates, echoing the reduced dislocation risk documented for primary hip replacement through the same route.

Fracture risk during implant removal was also lower than expected. Only one patient, 2.8 percent, sustained an intraoperative fracture at the calcar region during explantation, and one patient suffered a postoperative periprosthetic fracture eight days after reimplantation, both far below the 10 to 15 percent fracture rates reported in comparable two-stage series. The researchers credit their liberal use of femoral osteotomy, a controlled cutting of the femur performed in 19.4 percent of cases to facilitate safe stem removal, which deliberately converts a potential uncontrolled fracture into a planned, fixable one. All fractures and osteotomies were stabilized with cable wires, and remarkably, every fracture was managed through the anterior approach itself, demonstrating the versatility of the technique even in hostile surgical fields.

The microbiological findings add an intriguing layer to the story. Of the 52 microorganisms detected at the first stage, Cutibacterium species accounted for 28.8 percent and coagulase-negative staphylococci for 26.9 percent, with Gram-negative organisms making up 23.1 percent, a spectrum that earlier work by the same group has linked to the anterior approach. Fourteen of the second-stage cultures were positive, and in a striking 64.3 percent of these the organism differed from that found at the first stage, while only 21.4 percent harbored the same pathogen. All four patients who ultimately failed had culture-positive second stages, whereas patients with positive second-stage cultures who did not fail typically grew low-virulence organisms such as Cutibacterium or coagulase-negative staphylococci detected only after enrichment culture. This pattern suggests that positive second-stage cultures carry very different prognostic weight depending on the organism involved, a nuance that could refine how clinicians interpret cultures at reimplantation.

One further finding carries practical weight: patients who achieved successful reimplantation and remained infection free were significantly younger, with a median age of 66 years, than those who never received a new prosthesis, whose median age was 81 years, a difference that was highly statistically significant. Age-related medical fitness, rather than the virulence of the infecting organism, appears to be the decisive factor separating patients who complete the two-stage journey from those who must settle for spacer retention or a Girdlestone salvage. No significant difference in the distribution of high- versus low-virulence microorganisms was found between the reimplantation and non-reimplantation groups, reinforcing the point that patient physiology often trumps microbiology in determining outcomes.

The authors are candid about the limitations of their work. The retrospective, single-center design carries an inherent risk of selection bias, the sample of 36 patients limits statistical power, particularly for subgroup analyses of spacer type and microbiology, and the cohort is heterogeneous. Nevertheless, the study offers something genuinely scarce in the literature: five-year-plus follow-up data on two-stage revision performed entirely through the direct anterior approach, using a standardized diagnostic and treatment protocol. As the anterior approach continues to dominate primary hip replacement in many registries, an increasing share of infected replacements will present with anterior incisions, and reusing the same route preserves muscle that infection and prior surgery have already compromised. With reinfection, dislocation, spacer, and fracture rates all at the favorable end of published ranges, the Vienna data make a compelling case that the direct anterior approach is not merely an acceptable option for two-stage septic revision, but potentially an advantageous one.

Subject of Research: Two-stage revision surgery for chronic hip periprosthetic joint infection using the direct anterior approach

Article Title: Reinfection and complication rates in two-stage revision for chronic hip periprosthetic joint infections using the direct anterior approach

Article References: Simon, S., Mitterer, J. A., Frank, B. J. H., Huber, S., Sebastian, S., Gardete-Hartmann, S., & Hofstaetter, J. G. (2026). Reinfection and complication rates in two-stage revision for chronic hip periprosthetic joint infections using the direct anterior approach. Journal of Bone and Joint Infection, 11(4), 513-521. https://doi.org/10.5194/jbji-11-513-2026

Image Credits: AI Generated

DOI: 10.5194/jbji-11-513-2026

Keywords: periprosthetic joint infection, total hip arthroplasty, direct anterior approach, two-stage revision, antibiotic-loaded spacer, reinfection rate, hip dislocation, revision surgery, Cutibacterium, coagulase-negative staphylococci, orthopedic surgery, infection-free survival