Treatment patterns and failure rates associated with prosthetic joint infection in unicompartmental knee arthroplasty: A systematic review

Revision of unicondylar knee arthroplasty: an analysis of failure rates and contributing factors

BACKGROUND

The implantation rate of knee arthroplasty and, in particular of unicondylar knee arthroplasty (UKA), is increasing, and revision is a feared complication. The aim of this study was to identify factors influencing aseptic and septic revision that are of high interest for establishing preventive measures.

METHODS

Data were collected using the German Arthroplasty Registry (EPRD). Patients with UKA were analyzed using the multiple Log-rank test with Holm's method. Septic and aseptic revisions were calculated using Kaplan-Meier estimates. In total, 300,998 cases of knee arthroplasty were identified in the registry, and 36,861 patients with UKA were analyzed with a maximum follow-up of 7 years.

RESULTS

The primary reason for UKA revision surgery was aseptic loosening (32.5%), particularly loosening of the tibial component (19.0%), followed by infection (11.0%) and the progression of arthritis (10.0%). Over 7 years, 8.7% of UKA procedures required revision, 7.8% for aseptic causes and 0.9% for infection. Risk factors for aseptic revision included uncemented implants [hazard ratio (HR) 1.38] and low annual surgical volume (fewer than 25 UKAs/year, HR 1.86; fewer than 50 UKAs/year, HR 1.43). Significant risks for septic revision were grade III obesity (HR 1.83), male sex (HR 1.69), and high comorbidity scores (Elixhauser > 5, HR 1.67). The surgical volume did not affect septic revision rates.

CONCLUSION

Aseptic loosening is the primary cause of UKA revision, influenced by implant type and low surgical volume, while septic revisions are associated with patient factors such as obesity, male sex, and comorbidities. Improvements in implant selection, surgical expertise, and patient risk management may reduce revision rates.

LEVEL OF EVIDENCE

III, retrospective case-control study.

Comparison of Single- Versus Two-Stage Revision Knee Arthroplasty for the Treatment of Periprosthetic Knee Joint Infections

BACKGROUND

Periprosthetic joint infection (PJI) can be a complex and distressing complication following total knee arthroplasty (TKA). Both one-stage and two-stage revisions are the main options for treating chronic PJI of the knee; however, the best treatment option continues to be debated. We aimed to compare the rate of success by comparing the risk of re-infection between the two treatment options.

METHODS

Patients who underwent one-stage from 2009 to 2014 or two-stage revision from 2015 to 2020 for treatment of PJI of the knee were included. The Delphi-based consensus criteria were used to classify infections. The primary outcome was recurrent infection. Time from the index revision surgery to the return to the operating room for infectious reasons and non-infectious reasons was compared between the two groups.

RESULTS

A total of 66 patients underwent knee revision for PJI, in which 46 (69.7%) underwent one-stage and 20 (30.3%) underwent two-stage revision. Mean age (P = 0.57) and body mass index (BMI) (P = 0.33) were similar between the groups. The rate of no recurrence of infection was 89.1% in the one-stage group and 65.0% in the two-stage group (P = 0.034) at the mean follow-up time of 5.4 years (range, 2.2 to 10.3). The one-stage group was significantly more likely to have decreased time between the revision for re-infection (P = 0.012). There were no significant differences in rates of postoperative deep vein thrombosis, acute renal failure, long-term antibiotic use, or length of stay.

CONCLUSIONS

These results indicate that one-stage revision for treatment of PJI of the knee is at least as effective as two-stage revision. To our knowledge, this is the largest single-surgeon, single-protocol series of consecutive cases reported to date, with limited exclusion criteria.

Impact of intra-articular injection on infection risk and therapeutic effect after unicompartmental knee arthroplasty: a retrospective cohort study

BACKGROUND

Unicompartmental knee arthroplasty (UKA) is an effective treatment for single-compartment knee osteoarthritis. However, some patients experience lateral compartment pain after UKA. The impact of lateral compartment intra-articular injection on infection risk of the medial prosthesis and therapeutic outcomes in these patients remains controversial.

OBJECTIVE

This study aims to evaluate the impact of lateral compartment intra-articular injection after UKA on the risk of medial prosthetic joint infection, as well as its therapeutic effect on lateral compartment pain and inflammation. We hypothesized that lateral compartment intra-articular injection in patients with post-UKA lateral pain could provide better pain relief and functional outcomes without increasing the risk of medial prosthetic infection.

METHODS

This retrospective cohort study included patients who experienced lateral compartment pain after UKA at Jinshan Branch of Shanghai Sixth People's Hospital between January 2018 and December 2020. Patients were divided into two groups: those who received lateral compartment intra-articular injection for pain management (injection group) and those who received only oral medication (control group). The primary outcome was medial prosthetic infection rate within 6 months post-injection. Secondary outcomes included pain scores, knee function, and quality of life.

RESULTS

A total of 249 patients with post-UKA lateral compartment pain were included (144 in the injection group, 105 in the control group). There was no significant difference in medial prosthetic infection rates between the two groups (2.1% vs. 2.9%, p = 0.812). The injection group showed significantly better pain relief (VAS score) and knee function (KSS score) at 1 week and 1 month post-injection (p < 0.05). Quality of life measures (SF- 36) also showed improvements in the injection group at these early time points.

CONCLUSION

Intra-articular injection after UKA does not increase the risk of infection and may provide better short-term pain relief and functional outcomes. These findings support the safety and potential efficacy of this approach in managing apparent lateral knee post-operative pain and enhancing early recovery after UKA. However, larger prospective studies are needed to confirm these results and further explore the long-term impact of this intervention.

Arthroscopy Within Three Months Prior to Unicompartmental Knee Arthroplasty Is Associated With an Increased Rate of Periprosthetic Joint Infection

BACKGROUND

Arthroscopy remains a commonly performed procedure in patients who have meniscal or other osteochondral pathology prior to ultimately being indicated for unicompartmental knee arthroplasty (UKA). The purpose of this study was to examine the timing of knee arthroscopy prior to UKA and its association with 2-year periprosthetic joint infection (PJI) rates and medical and surgical complications.

METHODS

Patients undergoing UKA who had history of ipsilateral arthroscopy within 2 years prior to the UKA were identified in a national insurance database. A control cohort of propensity matched patients who did not have a history of arthroscopy was identified. Study cohorts were established based on timing of the arthroscopic procedure: 0 to 3, 3 to 6, 6 to12, and 12 to 24 months prior to UKA. Patients were included if they had 2-year postoperative follow-up after UKA. The 90-day rates of postoperative medical and 2-year surgical complications were recorded. Multivariate analysis was conducted to account for confounding variables and covariates.

RESULTS

A final cohort of 3,471 patients met inclusion criteria. Patients undergoing UKA within three months of the arthroscopic procedure demonstrated a higher incidence of PJI when compared to the control cohort (3.30 versus 1.12%, P = 0.012). In addition, there was an increased rate of periprosthetic fracture observed in those undergoing UKA within three months of arthroscopy when compared to the control (1.10 versus 0.20%, P = 0.010).

CONCLUSIONS

Patients undergoing ipsilateral arthroscopy within three months of a UKA demonstrated a nearly 3-fold increased incidence of PJI when compared to the control. There was no increased incidence of PJI when UKA was staged greater than three months after arthroscopy. These findings provide insight for preoperative considerations for arthroplasty surgeons in this patient population.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Survivorship of Periprosthetic Joint Infection in Unicompartmental Knee Arthroplasty: A Single Healthcare System's 23-Year Experience

INTRODUCTION

Unicompartmental knee arthroplasty (UKA) is increasingly favored in clinical practice due to its favorable long-term survival rates, positive clinical outcomes, and expedited recovery. Periprosthetic joint infections (PJIs) remain a formidable complication in knee arthroplasty, and guidelines for the management are limited. This study aims to assess the failure rates of débridement, antibiotics, and implant retention (DAIR) in UKAs, providing insights into optimal treatment management and infection-free survival for PJI in this context.

METHODS

Twenty-five patients met the inclusion criteria of PJI, as defined by Musculoskeletal Infection Society criteria, and were retrospectively reviewed from January 2000 to September 2023. Surgical treatment included 17 DAIRs (78%), six one-stage revision procedures (20%), and three two-stage revision procedures (12%). Seventeen patients (78%) had acute hematogenous infections (<3 weeks of symptoms). Kaplan-Meier survivorship analysis was done for reinfection and revision procedures.

RESULTS

The overall infection-free survival and all-cause survival regardless of management at 3 years was 60.1% (95% confidence interval [CI], 45.7% to 89.6%) and 55.8% (95% CI, 38.2% to 81.5%), respectively. Both two-stage and one-stage revision procedures had an infection-free survivorship of 100% at 3 years (95% CI, 100% to 100%). DAIR treatment had an infection-free survival at 3 years of 41.6% (95% CI, 22.4% to 77.4%). Nine of 17 patients (53%) undergoing DAIR were unsuccessful and required subsequent second DAIR, one-stage, or two-stage revision procedures.

DISCUSSION

The efficacy of DAIR following PJI in UKA is notably limited, suggesting a need for reevaluation of its role in managing UKA PJIs. Given the absence of established guidelines for PJI management specifically tailored to UKA, there is an urgent and compelling need for future studies to elucidate optimal clinical strategies to allow for the best treatment for patients.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Enhancing treatment outcomes for Acute Periprosthetic Hip Joint infection: optimizing debridement, antibiotics, and Implant Retention through vacuum sealing drainage in the deep tissue

BACKGROUND

Debridement, antibiotics, and implant retention (DAIR) for acute periprosthetic joint infection (PJI) is under debated since the reported success rate is inconsistent. This study aimed to explore the efficacy of vacuum sealing drainage (VSD) used as an adjunct to irrigation and debridement for acute PJI.

METHODS

Patients undergoing debridement, irrigation with component retention, and application of vacuum seal drainage in the deep portion surrounding the infected sites from January 2014 to February 2021 were retrospectively reviewed. The definition of failure included the requirement of prosthesis removal; persistent infection-related symptoms; suppressive antibiotics therapy due to failure of controlling the infection; infection-related death.

RESULTS

45 patients were included in this study with a mean follow-up of 45.62 ± 13.87 months. There were 28 males and 17 females with a mean age of 63.29 ± 17.74 months. The overall success rate was 86.67% with 6 failures. Multivariate analysis revealed a significant association between Charlson comorbidity index and treatment failure (OR = 2.226, 95% CI, 1.057-4.687, p = 0.035).

CONCLUSIONS

The incorporation of VSD in the deeper region enhances the outcomes of DAIR, achieving an 86.67% success rate in managing acute PJI. This approach offers a potentially safe and effective treatment, though patients with higher Charlson comorbidity index and elevated preoperative CRP levels face increased risks of failure.

[Low UKA implantation volume, comorbidities, male sex, and implantation of constrained TKA are risk factors for septic revision after knee arthroplasty implantation : A register-based study from the German Arthroplasty Register]

AIM

Periprosthetic joint infection (PJI) is one of the main causes of revision surgeries after total knee arthroplasty (TKA) and unicondylar knee replacement. Patient- and hospital-related risk factors must be evaluated to prevent PJI. This study identifies influencing factors and differences in infection rates between various types of implant.

METHODS

The basis for the data is the German Arthroplasty Register (EPRD). Septic revisions were calculated with the aid of Kaplan-Meier estimates, with septic revision surgery defined as the primary endpoint. Patients with constrained and unconstrained TKA or UKA were analysed using the Holm multiple log-rank test and the Cox proportional hazard model. The 300,998 cases of knee arthroplasty analysed included 254,144 (84.4%) unconstrained TKA, 9993 (3.3%) constrained TKA and 36,861 (12.3%) UKA, with a maximum follow-up of 7 years.

RESULTS

After 1 year, the PJI rate was 0.5% for UKA and 2.8% for TKA, whereas after 7 years it was 4.5% for UKA and 0.9% for TKA (p < 0.0001). In constrained TKA, the PJI rate was significantly increased compared with unconstrained TKA (p < 0.0001). After 1 year, the PJI rate was 2.0% for constrained TKA and 0.8% for unconstrained TKA, as well as 3.1% and 1.4% respectively after 7 years. Implantation of a constrained TKA (HR = 2.55), male sex (HR = 1.84), an increased Elixhauser Comorbidity Index score (HR = 1.18-1.56) and an implantation volume of less than 25 UKA per year (HR = 2.15) were identified as risk factors for revision surgeries; an Elixhauser Comorbidity Index score of 0 (HR = 0.80) was identified as a preventive factor.

CONCLUSIONS

A reduced implantation volume and constrained knee arthroplasty are linked to a higher risk of PJI. Comorbidities (increased Elixhauser Comorbidity Index score), male sex and a low UKA-implantation volume were identified as risk factors for PJI. Patients who fulfil these criteria need specific infection prevention measures. Further analyses are required to investigate the potential influence of prevention and risk factor modification.

LEVEL OF EVIDENCE

III.

Low implantation volume, comorbidities, male sex and implantation of constrained TKA identified as risk factors for septic revision in knee arthroplasty: A register-based study from the German Arthroplasty Registry

PURPOSE

Periprosthetic joint infection (PJI) is a major cause of revision surgery after total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA). Patient- and hospital-related risk factors need to be assessed to prevent PJI. This study identifies influential factors and differences in infection rates between different implant types.

METHODS

Data were obtained from the German Arthroplasty Registry. Septic revisions were calculated using Kaplan-Meier estimates with septic revision surgery as the primary endpoint. Patients with constrained and unconstrained TKA or UKA were analysed using Holm's multiple log-rank test and Cox's proportional hazards ratio. The 300,998 cases of knee arthroplasty analysed included 254,144 (84.4%) unconstrained TKA, 9993 (3.3%) constrained TKA and 36,861 (12.3%) UKA with a maximum follow-up of 7 years.

RESULTS

At 1 year, the PJI rate was 0.5% for UKA and 2.8% for TKA, whereas at 7 years, the PJI rate was 4.5% for UKA and 0.9% for TKA (p < 0.0001). The PJI rate significantly increased for constrained TKA compared to unconstrained TKA (p < 0.0001). The PJI rate was 2.0% for constrained TKA and 0.8% for unconstrained TKA at 1 year and 3.1% and 1.4% at 7 years. Implantation of a constrained TKA (hazard ratio [HR] = 2.55), male sex (HR = 1.84), increased Elixhauser score (HR = 1.18-1.56) and implant volume of less than 25 UKA per year (HR = 2.15) were identified as risk factors for revision surgery; an Elixhauser score of 0 (HR = 0.80) was found to be a preventive factor.

CONCLUSIONS

Reduced implant volume and constrained knee arthroplasty are associated with a higher risk of PJI. Comorbidities (elevated Elixhauser score), male sex and low UKA implant volume have been identified as risk factors for PJI. Patients who meet these criteria require specific measures to prevent infection. Further research is required on the potential impact of prevention and risk factor modification.

LEVEL OF EVIDENCE

Level III.

Change in patellar height in medial and lateral unicompartmental knee arthroplasty: a clinical trial

INTRODUCTION

Evidence on patellar height changes following unicompartmental knee arthroplasty (UKA) is lacking. Therefore, this study compared the patella height in patients who underwent medial versus lateral UKA. Moreover, a subgroup analysis was conducted to investigate whether sex, age, and BMI of the patients exert an influence on the postoperative patellar height.

METHODS

Radiographs and hospital records of patients undergoing UKA were prospectively collected. Surgeries were performed by one author with long experience in UKA in a highly standardised fashion. The implants were fixed-bearing medial PPK (Zimmer Biomet, Warsaw, Indiana, USA) and fixed-bearing lateral ZUK (Lima Corporate, Udine, Italy). The patellar height was measured using the Insall-Salvati and Caton-Deschamps indices.

RESULTS

A total of 203 patients were included: 119 patients were included in the medial and 84 in the lateral UKA. The mean age of the patients was 68.9 ± 6.7 years, and the mean BMI was 28.1 ± 4.1 kg/m2. 54% (110 of 203 patients) were women. On admission, between-group comparability was found in age, BMI, sex, and length of the follow-up. No between-group and within-group difference was detected pre- and post-operatively in the Insall-Salvati and Caton-Deschamps indices in patients who have undergone medial versus lateral UKA. Concerning the subgroup analyses, no between-group and within-group difference was detected pre- and post-operatively in all comparisons according to sex, age, and BMI.

CONCLUSION

No difference was found in patella height in patients who have undergone medial compared to lateral UKA. Furthermore, there was no evidence of an association between patient characteristics (sex, age, BMI) and patella height between medial and lateral UKA.

[Research progress of failure and revision of unicompartmental knee arthroplasty]

Objective

To conclude the failure factors of unicompartmental knee arthroplasty (UKA), and summarize the research progress of revision surgery.

Methods

The literature on UKA at home and abroad in recent years was reviewed to summarize its risk factors, treatment methods, including the evaluation of bone loss, prosthesis selection, and surgical techniques.

Results

The factors inducing UKA failure mainly include improper indications, technical errors, and others. The application of digital orthopedic technology can reduce failures caused by surgical technical errors and shorten the learning curve. There are a variety of options for revision surgery after UKA failure, including polyethylene liner replacement, revision with UKA or total knee arthroplasty, with adequate preoperative evaluation prior to implementation. The biggest challenge in revision surgery is the management and reconstruction of bone defects.

Conclusion

There is a risk of failure in UKA, which needs to be treated with caution and should be determined according to the type of failure.