Hip spacers are designed as temporary devices, meant to hold the joint open for weeks or months while antibiotics fight off infection before a new prosthesis is implanted. In practice, though, a meaningful fraction of patients never make it to that second surgery and end up living with their spacer indefinitely. Studies tracking planned two-stage hip revisions consistently find that roughly one in five patients keeps the spacer long-term, whether by medical necessity or by choice. The reasons are varied, and the outcomes are more nuanced than you might expect.
What a Hip Spacer Is Supposed to Do
When a hip replacement becomes infected, the most established treatment involves removing the failed implant, placing an antibiotic-loaded cement spacer in the gap, and then implanting a fresh prosthesis once the infection clears. This is the two-stage revision, and the spacer plays two roles during the interval: it delivers high concentrations of antibiotics directly to the infected tissue, and it physically maintains the joint space so surrounding muscles and tendons do not shrink down and scar, which would make the second surgery far more difficult.1PubMed. Spacers in two-stage strategy for periprosthetic infection The technique has been used for decades and remains a cornerstone of treating prosthetic joint infection.2PubMed Central. Articular spacers in two-stage revision arthroplasty for prosthetic joint infection of the hip and the knee
The interval between stages is typically at least six weeks, though it often stretches longer while surgeons confirm the infection is under control.1PubMed. Spacers in two-stage strategy for periprosthetic infection During that window, some spacers are static blocks that hold space but do not allow much movement, while others are articulating spacers shaped more like an actual hip joint, letting you bend and walk to some degree. The articulating type tends to produce better function during the waiting period, and there is evidence it also leads to smoother reimplantation surgery when the second stage does happen.
Why Some Spacers Stay In
The most common reason a spacer becomes permanent is that the patient is too sick to undergo another major operation. In one study examining patients who retained their spacers, about 69% did so because they were medically unfit for further surgery.3PubMed. Retained Antibiotic Spacers After Total Hip and Knee Arthroplasty Resections: High Complication Rates These are often older adults with heart disease, lung problems, or other conditions that make general anesthesia and a lengthy operation genuinely dangerous. A study of 90 patients undergoing two-stage revision found that mortality correlated with higher comorbidity burden and age over 80, and about 21% of patients never reached reimplantation.4PubMed Central. Preoperative predictors of spacer retention and mortality in two-stage revision for infected total hip arthroplasties: a single-center experience of 90 patients
Bone loss is another obstacle. Infection chews through bone, and the process of removing a failed implant can destroy even more. In a study characterizing bone damage during two-stage revision, about 21% of patients with planned reimplantation were ultimately not reimplanted, in part because there was not enough healthy bone left to anchor a new prosthesis.5PubMed. Characterizing Femoral and Acetabular Bone Loss in Two-Stage Revision Total Hip Arthroplasty for Infection When the structural foundation is compromised, surgeons sometimes decide that another operation would cause more harm than benefit.
Persistent or drug-resistant infection adds another layer. Patients who have already been through multiple revision surgeries and carry resistant bacteria face diminishing odds of a successful outcome. In some of these cases, a permanently retained antibiotic spacer becomes the pragmatic alternative to amputation.6Techniques in Orthopaedics. Cephalomedullary Nail as a Definitive Antibiotic Spacer for Multidrug Resistant Periprosthetic Infection of a Proximal Femoral Endoprosthesis
And then there is patient choice. Some people simply do well enough with the spacer that they decline a second surgery. One case report documents a patient who kept an articulating spacer for six years after refusing reimplantation. He walked with a frame, had minimal hip pain, and showed no signs of infection, loosening, or fracture.7Journal of Orthopaedics, Trauma and Rehabilitation. Retention of prosthetic articulating spacer after infected hip arthroplasty as a semipermanent implant: A case report Multiple studies have noted that some patients with functional articulating spacers refuse further procedures because they are satisfied with how the spacer performs.8PubMed Central. Improved patient reported outcomes with functional articulating spacers in two-stage revision of the infected hip
How Well Do Retained Spacers Actually Function
This is where the picture gets surprisingly encouraging for some patients. A study tracking 15 patients who kept their spacers for an average of about three and a half years found that survivors had Harris Hip Scores around 92 out of 100, which is considered excellent function. Some of those patients maintained well-functioning spacers for up to six years without needing additional surgery.9PubMed. The fate of unplanned retention of prosthetic articulating spacers for infected total hip and total knee arthroplasty That said, four of the fifteen died with the spacers still in place, which underscores that these tend to be medically fragile patients to begin with.
The type of spacer matters enormously for function. Patients treated with articulating spacers that mimic a real hip joint reported significantly better quality-of-life scores across multiple measures compared to those with simpler prefabricated spacers. Infection eradication rates were also numerically higher with the functional articulating design, at roughly 93% versus 78%, though the difference did not reach statistical significance.8PubMed Central. Improved patient reported outcomes with functional articulating spacers in two-stage revision of the infected hip For low-demand patients, this level of function may eliminate the need for a second surgery entirely, reducing both the physical toll and the cost.10Orthopaedic Proceedings. THE EFFECTIVENESS OF THE FUNCTIONAL ARTICULATING SPACER FOR TWO-STAGE REVISIONS FOR PROSTHETIC JOINT INFECTIONS: A CASE SERIES STUDY FROM SOUTHLAND HOSPITAL
The Durability Problem
Even when a retained spacer functions well at first, the material itself was never engineered for permanent use. Spacers are made of polymethylmethacrylate (PMMA) bone cement, which is hard but brittle compared to the metals and ceramics used in actual hip prostheses. Several spacer fractures have been documented even in patients bearing only partial weight on the joint.11Medical Engineering & Physics. Development of a reinforced PMMA-based hip spacer adapted to patients’ needs
Younger, more active patients face a higher risk of mechanical failure because they put more stress on the spacer during daily life. In one study, the spacer stem fracture rate was about 10%, and most fractures occurred in the lower part of the stem. Spacers reinforced with only thin Kirschner wires for internal support were particularly vulnerable.12BMC Musculoskeletal Disorders. Mechanical failure of articulating polymethylmethacrylate (PMMA) spacers in two-stage revision hip arthroplasty: the risk factors and the impact on interim function Preformed spacers with stronger metal cores offer better durability, but even those are designed to last months, not decades.
A systematic review pooling data across many studies found that the overall rate of mechanical complications with hip spacers was around 19%. Dislocations were the most frequent issue at roughly 11%, followed by spacer fractures and peri-spacer bone fractures each at about 3.5%, with acetabular complications (erosion or protrusion into the pelvis) occurring less often at around 1%.13PubMed Central. Mechanical complications of hip spacers: a systematic review of the literature These numbers reflect the spacer’s intended short lifespan. When a spacer stays in for years, the cumulative risk of something going mechanically wrong climbs accordingly.
What Happens When the Antibiotics Run Out
One of the less-discussed concerns with long-term spacer retention is that the antibiotic delivery, which is the spacer’s primary medical purpose, is time-limited. Antibiotic release from bone cement follows a predictable pattern: a burst of high-dose release in the first day or two, followed by a gradual decline. Most studies indicate that drug levels remain above the effective threshold for roughly six to twelve weeks.14PubMed Central. Antibiotic Elution from Cement Spacers and Its Influencing Factors After that window closes, the spacer is essentially an inert piece of cement as far as infection control goes.
Laboratory testing has confirmed that after the initial burst, spacers show very little additional antibiotic release beyond the first week.15PubMed. In vitro release of antibiotics from commercial PMMA beads and articulating hip spacers The release also decreases consistently over a six-week period regardless of the antibiotic combination or cement brand used, though some formulations do release a greater total quantity before they taper off.16PubMed Central. Enhanced antibiotic release from bone cement spacers utilizing dual antibiotic loading with elevated vancomycin concentrations in two-stage revision for periprosthetic joint infection
This finite antibiotic window means that if you are retaining a spacer permanently, you are living with a foreign body that can no longer actively fight off bacteria. The cement surface can potentially become a substrate for bacterial biofilm. That does not mean reinfection is inevitable, but it does mean the protective drug effect that justified the spacer in the first place is no longer active after the first few months. Patients who keep their spacers long-term sometimes remain on oral suppressive antibiotics indefinitely to compensate, though the evidence on how well that strategy works over many years is still fairly thin.
Complications Specific to Long-Term Retention
Spacer-related complications are well-documented even during the standard waiting period of weeks to months. Dislocations, which occurred in about 17% of patients in one large single-center series, are the most common acute problem. Most dislocations can be managed by popping the joint back into place and using a brace, but recurrent dislocations sometimes require additional surgery or even conversion to a Girdlestone procedure, where the hip is left without any implant at all.17International Journal of Medical Sciences. Complications after spacer implantation in the treatment of hip joint infections
In one study of patients who received molded hip spacers, the complication profile was substantial even over a relatively standard timeframe: about 15% experienced dislocations, 18% had periprosthetic fractures (breaks in the bone around the spacer), 9% had bent or fractured spacer stems, and 18% had clinically meaningful subsidence, where the spacer gradually sinks into the bone. Patients who had previously undergone an extended trochanteric osteotomy, a technique used to remove a well-fixed prior implant, fared particularly badly, with dislocation, fracture, and stem breakage rates all several times higher.18PubMed Central. Clinical Outcomes After Stage-One Antibiotic Coated Molded Hip Spacer – Section: RESULTS
Bone fracture around the spacer and gradual erosion of the acetabulum (the hip socket) are also documented. These complications overlap with the broader pattern of mechanical failure, but they carry an additional concern for patients retaining spacers long-term: if the bone deteriorates further while the spacer is in place, it may eventually close off the option of reimplantation entirely, even if the patient’s health later improves enough to tolerate surgery.19PubMed Central. Mechanical complications and reconstruction strategies at the site of hip spacer implantation
Monitoring a Retained Spacer
When reimplantation is not going to happen, ongoing surveillance becomes the substitute for definitive treatment. Patients who keep their spacers need regular clinical and radiographic follow-up to catch complications before they become emergencies. One long-term study following patients with preformed spacers for up to six years stressed that careful, periodic monitoring is essential to detect problems such as loosening, subsidence, bone erosion, or recurrent infection.20PubMed. Six-year follow-up of a preformed spacer for the management of chronically infected total hip arthroplasty
In practice, this usually means regular X-rays to check spacer position and bone quality, periodic blood tests to monitor inflammatory markers that might signal infection, and clinic visits where the surgeon evaluates pain, range of motion, and walking ability. The frequency of these visits varies, but they typically start at every few months and may spread to every six to twelve months once things have been stable for a while. This is not onerous compared to the alternative of another major surgery, but it is a commitment that lasts as long as the spacer does.
One-Stage Revision and Other Alternatives
The two-stage revision is not the only way to treat an infected hip replacement, and the growing use of one-stage revision is relevant to the spacer-retention conversation because it eliminates the spacer entirely. In a one-stage procedure, the infected implant is removed and a new prosthesis is cemented in during the same operation. Meta-analyses and registry data both suggest that one-stage revisions produce comparable or even better outcomes than two-stage procedures for many patients, with similar reinfection rates.21Orthopaedic Proceedings. ONE-STAGE VERSUS TWO-STAGE REVISION HIP ARTHROPLASTY: CAN WE CONFIRM THE DATA FROM META-ANALYSIS IN REAL-WORLD REGISTRY DATA?22PubMed Central. One- versus two-stage septic hip and knee revision surgery: a comparative cohort outcome study with short- to mid-term follow-up
One-stage revision is generally recommended for patients with lower-virulence infections and intact soft tissue around the hip.23PubMed Central. Comparative reinfection rate of one-stage versus two-stage revision in the management of periprosthetic joint infection following total hip arthroplasty: a meta-analysis It is not suitable for everyone, particularly those with highly resistant organisms, extensive bone loss, or compromised soft tissues. But for appropriate candidates, it spares them the months-long interval of living with a spacer and the risk of never proceeding to reimplantation. If you are being counseled about treatment options for an infected hip, asking about one-stage revision is reasonable, especially if your infection profile is straightforward.
Newer Spacer Technology
Three-dimensional printing has started to change how spacers are made. Traditional hand-molded spacers are shaped by the surgeon in the operating room using generic molds, which limits how well they fit a given patient’s anatomy. 3D-printed spacers can be custom-designed from CT scans before surgery, achieving a better anatomical match. In a clinical study comparing 3D-printed antibiotic-loaded spacers to conventional ones, patients with the custom-printed spacers had significantly higher hip function scores both during the spacer phase and after reimplantation, with the difference averaging about nine to eleven points on the Harris Hip Score.24PubMed. 3D-printed antibiotic-loaded bone cement spacers as adjunctive therapy for hip periprosthetic infection after arthroplasty: A clinical assessment
Better fit may translate to fewer mechanical problems like dislocation and subsidence, which are among the main concerns for anyone retaining a spacer long-term. Whether 3D-printed spacers will prove durable enough to change the calculus on permanent retention is still an open question, since the underlying material remains PMMA bone cement. But for patients who are likely to retain a spacer for years, a device that fits more precisely and functions more like a natural joint is a clear step in the right direction. Reinforced metal cores and improved cement formulations are also evolving, though none has yet produced a spacer that a surgeon would describe as truly “permanent” by design.
When Keeping the Spacer Makes Sense
The honest framing is that a permanently retained hip spacer is a compromise, not a solution. It works best for people whose surgical risks outweigh the benefits of reimplantation: patients who are elderly, medically fragile, or have low physical demands. For a relatively sedentary person in their eighties who can walk short distances with a frame and experiences minimal pain, the spacer may provide enough quality of life that a second major hip surgery is simply not worth the risk. The functional scores from studies confirm this can work well for years.
For younger or more active patients, the math looks different. The risk of mechanical failure, bone erosion, and the loss of future reconstructive options all accumulate over time. A spacer that functions well at two years is not guaranteed to function well at ten. If you are facing this decision and are under about seventy with a reasonable activity level, most orthopedic surgeons will push for reimplantation or explore alternative approaches unless there is a compelling reason not to.
There is no formal threshold in any guideline that designates a spacer as “permanent.” The decision typically evolves: the second surgery gets delayed, then deferred, and eventually the patient and surgeon agree that it is not going to happen. In clinical literature, the term “unplanned retention” captures this trajectory well. The spacer was never meant to stay, but it did, and for a specific subset of patients, that turns out to be a tolerable outcome. The research suggests that these patients do need lifelong monitoring and should be under the care of a surgeon who can intervene if complications arise, but many of them manage reasonably well for years with the device they were never supposed to keep.9PubMed. The fate of unplanned retention of prosthetic articulating spacers for infected total hip and total knee arthroplasty