Periprosthetic joint infection in unicompartmental knee arthroplasty: treatment options and outcomes. What is the current evidence in literature?

INTRODUCTION

Periprosthetic joint infections (PJI) following unicompartmental knee arthroplasties (UKAs) will increase. The aim of this review is to evaluate current evidence regarding treatment options, complications, clinical and radiological outcomes of PJI management in UKAs.

METHODS

A systematic review of English literature was performed. Retrospective and prospective studies providing treatment options, complications, clinical and radiological outcomes of PJI following UKAs were included. PJI type, treatment, survival rate with no reoperation for infection and survival rate with no reoperation for any cause were evaluated.

RESULTS

Eleven articles were included. Three studies focusing on PJI following UKA (45 cases) report a survival rate with no reoperation for infection of 68.9% and a survival rate with no reoperation for any cause of 48.9%. Eight articles concerning UKA failure modes (28 cases) overestimate survival rate with no reoperation for infection (88.9%) and survival rate with no reoperation for any cause (88.9%) (p < 0.05). DAIR reports a rate of infection eradication failure ranging from 43.8 to 100%. 1SE allows for a survival rate with no reoperation for infection of 100%. 2SE reports a rate of infection eradication failure ranging from 0 to 12.5%. A high rate of early aseptic reoperation is reported, despite infection eradication (20% in DAIR; 28.5% in 2SE).

CONCLUSIONS

Treatment strategy is determined by symptom timing, PJI type (acute vs chronic), causative organism, patient's comorbidities. A longer duration of PJI or severe host and extremity status seems to require 2SE or 1SE. Patients who have a shorter duration of PJI could receive DAIR.

High Rate of Reinfection With New Bacteria Following One-Stage Exchange for Enterococcal Periprosthetic Infection of the Knee: A Single-Center Study

BACKGROUND

A wide range of success rates following the surgical management of enterococcal periprosthetic joint infection (PJI) with a tendency toward worse outcomes have been reported. However, the role of 1-stage exchange remains under-investigated. Therefore, we aimed to evaluate our results after the 1-stage knee exchange for enterococcal PJI.

METHODS

Forty patients were retrospectively included between 2002 and 2017 with a mean follow-up of survivors of 80 months (range 22-172; standard deviation [SD] = 5). Polymicrobial infections occurred in 45% (18/40) of patients. Patients' characteristics, joint-related data, and antibiotic therapy were recorded. Rates of enterococcal infection relapse, reinfection with new microorganisms, and re-revision for any reason were determined. Bivariate analysis was conducted to identify risk factors of infection recurrence.

RESULTS

Revision surgery was required in 22 cases (55%) with a mean time to revision surgery of 27 months (range 1-78; SD = 25). Indications for aseptic revisions (18%) included aseptic loosening (10%), periprosthetic fracture (5%), and patellar instability (3%). The most common cause of re-revision was a subsequent PJI (15/22; 68%) after a mean time of 22 months (range 1-77; SD = 24). Overall infection recurrence rate was 37.5% (15/40), substantially due to entirely non-enterococcal infections (9/15; 60%). Infection relapse with Enterococci occurred in 4 cases (10%) within 16 months postoperatively. Older patients (P = .05) and male gender (P = .05) were associated with a higher risk of infection recurrence.

CONCLUSION

Overcoming the Enterococci using the 1-stage exchange for knee PJI is achievable but the rate of reinfection due to new microorganisms is high . However, the overall infection recurrence rate is comparable to other treatment approaches.

An Alternative One-Stage Exchange Arthroplasty Technique: For the Chronic Infected Total Hip

Background There are various algorithms for the treatment of prosthetic joint infections (PJI). Currently, a two-stage hip exchange is considered the "gold standard" of care for treatment of chronic hip PJIs. However, there has been recent debate whether a one- or two-stage exchange offers the correct treatment. One-stage exchange arthroplasty has particularly gained interest due to less morbidity, mortality, and functional impairment. Methods In a retrospective case series, the outcome of patients with chronic hip PJIs treated with our one-stage exchange arthroplasty was analyzed. Between January 2015 and January 2020, eight patients underwent a one-stage exchange hip arthroplasty by a single surgeon at a single institution for a chronically infected total hip arthroplasty (THA). Original diagnosis of PJI was made in accordance with the 2011 version of the Musculoskeletal Infection Society (MSIS) criteria. The femoral stem was cemented with antibiotic-impregnated cement, and the polyethylene acetabular liner was cemented directly onto the acetabular bone with antibiotic-impregnated cement. Results Of the eight patients, three were female and five were male with a mean age of 70.5 years (SD 11.2, range 53-87). Six patients (75%) had infection eradication with retention of a stable implant and no additional surgery at a mean follow-up of 35.7 months (range 17-50). One patient (12.5%) underwent closed reduction for a dislocated THA at one month; however, this patient remained infection-free at the most recent follow-up of 41 months. One patient (12.5%) who was the oldest patient (87 years) died 18 days postoperatively. Overall, all living patients (87.5%) retained their one-stage exchange THA. One patient (12.5%, CI 95% 0.3-52.7) required additional surgery in the form of a closed reduction and zero patients (0.0%, CI 95% 0.0-36.9) required additional open surgery.  Conclusion Single-stage exchange arthroplasty with an antibiotic-impregnated cemented femoral stem and antibiotic-impregnated cemented polyethylene acetabular liner may be a useful option for the treatment of chronic hip PJIs. Our case series provides evidence that infection eradication and function preservation are possible using our one-stage exchange arthroplasty technique in a chronically infected THA. However, a multi-center study with randomization is necessary to further validate our results.

Treatment and Outcome of Periprosthetic Joint Infection in Unicompartmental Knee Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) after unicompartmental knee arthroplasty (UKA) is a devastating but poorly understood complication, with a paucity of published data regarding treatment and outcomes. This study analyzes the largest cohort of UKA PJIs to date comparing treatment outcome, septic and aseptic reoperation rates, and risk factors for treatment failure.

METHODS

Twenty-one UKAs in 21 patients treated for PJI, as defined by Musculoskeletal Infection Society criteria, were retrospectively reviewed. Minimum and mean follow-up was 1 and 3.5 years, respectively. Fourteen (67%) patients had acute postoperative PJIs. Surgical treatment included 16 debridement, antibiotics, and implant retentions (DAIRs) (76%), 4 two-stage revisions (19%), and 1 one-stage revision (5%). Twenty (95%) PJIs were culture positive with Staphylococcus species identified in 15 cases (71%).

RESULTS

Survivorship free from reoperation for infection at 1 year was 76% (95% confidence interval, 58%-93%). Overall survival from all-cause reoperation was 57% (95% confidence interval, 27%-87%) at 5 years. Two additional patients (10%) underwent aseptic revision total knee arthroplasty for lateral compartment degeneration 1 year after DAIR and tibial aseptic loosening 2.5 years after 2-stage revision. All patients who initially failed PJI UKA treatment presented with acute postoperative PJIs (5 of 14; 36%).

CONCLUSION

Survivorship free from persistent PJI at 1 year is low at 76% but is consistent with similar reports of DAIRs for total knee arthroplasties. Furthermore, there is low survivorship free from all-cause reoperation of 71% and 57% at 2 and 5 years, respectively. Surgeons should be aware of these poorer outcomes and consider treating UKA PJI early and aggressively.

Midterm Results After Tantalum Cones in 1-Stage Knee Exchange for Periprosthetic Joint Infection: A Single-Center Study

BACKGROUND

The use of tantalum cones to reconstruct extensive bone defects in revision total knee arthroplasty has been established. We aimed to evaluate the midterm results after 1-stage knee exchange for periprosthetic joint infection using tantalum cones.

METHODS

Seventy-two patients (mean age, 70 ± 8.2 years) treated with a 1-stage exchange for infected total knee arthroplasty using porous tantalum cones, between 2011 and 2016, were retrospectively included. Either rotating or pure hinge system in combination with femoral and/or tibial cones was used. Survivorship analysis (septic and aseptic) was performed. Prospectively, functional outcome was assessed at a mean follow-up of 49.9 ± 18.8 months (range, 24-88).

RESULTS

A total of 15 patients (21%) were rerevised, 8 (11.1%) for infection and 7 (10%) for aseptic loosening, requiring cone exchange in 12 patients (17%). Cone-related survival free from any revision was 83% ± 3.8 standard deviation (95% confidence interval, 74-90), and infection-free survival was 89% ± 4.2 standard deviation (95% confidence interval, 76-93). No significant correlation was reported between the types of prosthesis used (P = .8) or implanted cones and failure (P = .6). History of a previous septic revision increased the risk of cone revision after the index surgery (P < .001). Preoperative Hospital for Special Surgery knee score improved from 47 ± 16 (range, 14-87) to 60 ± 17 (range, 24-84) points at the latest follow-up.

CONCLUSION

First study reports on outcomes of the 1-stage exchange using tantalum cones for knee periprosthetic joint infection with additional severe bone loss. Midterm cone-related and infection-free survival offered good results and provided reasonable functional outcomes.