High Rates of Aseptic Loosening After Revision Total Knee Arthroplasty for Periprosthetic Joint Infection

Abstract

With increasing life expectancy, the demand for knee replacement is continuously rising. Despite the use of antibiotic prophylaxis and improved aseptic surgical techniques, periprosthetic joint infection (PJI) still occurs in 1% to 5% of patients after primary arthroplasty. An open question is the influence of PJI and resulting surgical procedures on the occurrence of long-term complications such as aseptic loosening. Patients needing multiple revision surgeries are especially at risk for decreases in bone mass and damage to the medullary cavity. Thus, we theorized that prior surgeries on the affected knee increase the risk of aseptic loosening in patients with PJI.

Methods: We retrospectively analyzed the cases of 100 patients who underwent total knee replacement exchange surgery as a result of PJI. In addition to clinical, paraclinical, and radiographic examination, we assessed comorbidities and the number of prior surgeries.

Results: Prosthetic survival was drastically decreased after PJI-related revision arthroplasty: during the first 7.3 years after reimplantation, 22% and 16% of all patients had aseptic loosening and recurrent PJI, respectively. The prevalence of aseptic loosening was 27.8% for female and 15.2% for male patients. A significant association between increasing patients' American Society of Anesthesiologists (ASA) classification and prosthetic failure rates was found, as was a strong correlation between number of prior surgeries and aseptic loosening.

Conclusions: In this study, we found notable rates of aseptic loosening and recurrent PJI following PJI-related revision arthroplasty. The difference in the rate of aseptic loosening among male and female patients supports theories of the role of bone metabolism in the development of aseptic loosening. The economic and clinical burdens of prosthetic failure make it paramount to gain a better understanding of bone metabolism in PJI. Additional research should address the need to optimize treatment strategies to increase prosthetic survival.

Level of evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Fig. 1

Figs. 1-A and 1-B Prosthetic survival rates. Fig. 1-A Diagnosed recurrent PJI or aseptic loosening was considered failure of the prosthesis. While only 2.0% of all patients had failure of the prosthesis at year 1, the failure rate was drastically elevated to 26.0% within 5 years. Prosthetic survival continued to decline until the end of our study and was 62.0% at 7.3 years. Fig. 1-B Comparison of prosthetic failure due to recurrent PJI (dashed line) and aseptic loosening (solid line). In the first 5 years, the prevalence of recurrent PJI was higher than the prevalence of aseptic loosening. At 7.3 years, 16.0% of all patients had experienced recurrent PJI. In comparison, 22.0% were diagnosed with aseptic loosening.

Fig. 2

Figs. 2-A through 2-F Images of a 63-year-old patient who had recurrent PJI with multiple revision surgeries. Fig. 2-A The patient experienced recurrent PJI after having received a hinged knee prosthesis during revision arthroplasty due to PJI 2 years prior. Fig. 2-B First-stage revision arthroplasty: prosthesis removal and temporal arthrodesis using a spacer and antibiotic-loaded cement. Fig. 2-C Second-stage revision arthroplasty: reimplantation of a hinged knee prosthesis 6 weeks later. Fig. 2-D Clinical and radiographic signs of aseptic loosening (arrows) of the tibial component after 2 years. Fig. 2-E After clinical, pathological, and microbiological exclusion of infection, the patient’s tibial component was changed to a cementless prosthesis. Fig. 2-F Good clinical, functional, and radiographic outcomes in the 1-year follow-up examination.

Fig. 3

Association between prosthetic failure rate and ASA score. Most patients were scored as ASA 2 or 3. While only 1 patient classified as ASA 1 had recurrent PJI, 6.0% of all patients had aseptic loosening and 4.0% had recurrent PJI in the ASA 2 group. The prevalence of long-term complications was highest in the ASA 3 group: 16.0% and 13.0% of all patients were diagnosed with aseptic loosening or recurrent PJI, respectively. *Significant difference among the groups (p < 0.05).

Fig. 4

Figs. 4-A and 4-B Correlations of the prevalence of aseptic loosening and recurrent PJI with number of prior surgeries. Fig. 4-A Prevalence of aseptic loosening correlated strongly (r = 0.91) with number of prior surgeries on the affected knee. Fig. 4-B Prevalence of recurrent PJI did not correlate (r = 0.23) with number of prior surgeries. The linear trend line is shown as a dashed line.