Treatment Outcomes in Gram Negative Periprosthetic Joint Infection

Introduction: Outcomes associated with periprosthetic joint infection (PJI) involving Gram negative (GN) organisms are poorly understood. While prevailing beliefs indicate that GN PJI cases have poorer prognoses than Gram positive (GP) cases, the current literature is sparse and inconsistent. Objective: The purpose of this study is to systematically compare the treatment outcomes for GN PJI versus GP PJI. Methods: A retrospective review of 1189 PJI cases between 2007 and 2017 was performed using an institutional PJI database. Treatment failure defined by the Delphi criteria was compared between cases with only GN organisms (n=45) and only GP organisms (n=663). Cox multivariate regression was used to predict time to failure. Results: GN status did not have significantly higher rates of treatment failure compared to GP PJI (OR=1.021, p=.375) in the multivariate analysis. After sub-analysis of only two-stage exchange procedures, GN cases were significantly less likely to reach reimplantation than GP cases (OR=.182, p\u3c.0001). Patients with GN infections were older (p=.041) and had more comorbidities (p\u3c.0001) than GP patients. Conclusions: While there was no observed difference in the overall Delphi failure rates between GN and GP PJI cases, GN patients were significantly less likely to reach reimplantation. We hypothesize this is largely a result of the GN patients being older and more comorbid hosts. This data increases insight into the risk factors and outcomes of GN PJI. Further research is needed to investigate the utility of alternate procedures to the two-stage exchange in older or immunocompromised patients

Return to Work Following Tibial Tubercle Osteotomy for Patellofemoral Osteoarthritis and Pain.

PURPOSE: To evaluate the ability of patients to return to work following anteromedialization (AMZ) tibial tubercle osteotomy (TTO) due to isolated patellofemoral osteoarthritis or pain. METHODS: Consecutive patients undergoing AMZ TTO were reviewed retrospectively at a minimum of 1 year postoperatively. Patients completed a subjective work questionnaire, a visual analog scale for pain, as well as a Kujala questionnaire and satisfaction questionnaire. RESULTS: Fifty-seven patients (61 knees; average age: 32.7 ± 9.6 years) were contacted at an average follow-up of 4.86 ± 2.84 years postoperatively. The preoperative Kujala score improved from 55.7 ± 17.8 to 84.6 ± 15.8 at final follow-up (P < 0.001). Thirty-seven patients (64.9%) were employed within 3 years prior to surgery and 34 patients (91.9%) were able to return to work by 2.8 ± 2.6 months postoperatively. However, only 27 patients (73.0%) of patients were able to return to the same level of occupational intensity. Patients who held sedentary, light-, medium-, or high-intensity occupations were able to return to work at a rate of 100.0%, 93.8%, 77.8%, and 100.0% by 2.2 months, 3.0 months, 3.1 months, and 4.0 months, postoperatively. No patients underwent revision TTO or conversion to arthroplasty by the time of final follow-up. CONCLUSION: In patients with focal patellofemoral osteoarthritis or pain, AMZ TTO provides a high rate of return to work (91.9%) by 2.8 ± 2.6 months postoperatively. Patients with higher intensity occupations may take longer to return to work than those with less physically demanding occupations. LEVEL OF EVIDENCE: III

Does Ligamentous Laxity Protect Against Chondral and Osteochondral Injuries in Patients With Patellofemoral Instability?

Background: Many patients undergoing medial patellofemoral ligament (MPFL) reconstruction for patellofemoral instability have chondral or osteochondral injuries requiring treatment. Hypothesis: In patients undergoing MPFL reconstruction for patellofemoral instability, those with ligamentous laxity (LAX) would be less likely to have chondral or osteochondral defects requiring surgical intervention compared with those with no laxity (NLX). Study Design: Cohort study; Level of evidence, 2. Methods: Included were 171 patients with patellofemoral instability (32 men, 139 women; mean age, 22 years [range, 11-57 years]) who underwent MPFL reconstruction between 2005 and 2015. Patients with a Beighton-Horan score ≥5 were considered LAX (n = 96), while patients with scores(n = 75). Preoperative magnetic resonance images were evaluated to determine the presence, size, and location of chondral or osteochondral injury as well as the grade according to the Outerbridge classification. Documented anatomic measurements included tibial tubercle-trochlear groove (TT-TG) distance, Caton-Deschamps Index (CDI) for patellar height, and the Dejour classification for trochlear dysplasia. Results: Of the 171 patients, 58 (34%) required a surgical intervention for a chondral or osteochondral defect: chondroplasty (29/58; 50%), particulated juvenile cartilage implantation (18/58; 31%), microfracture (16/58; 28%), osteochondral fracture fixation (2/58; 3.4%), and osteochondral allograft (2/58; 3.4%). While there was no statistical difference in the proportion of patellar chondral or osteochondral injuries between patients with NLX (58%) versus LAX (67%) ( Conclusion: For patients who sustained patellar or femoral chondral or osteochondral injuries, compared with their counterparts with NLX, patients with LAX were less likely to have severe (grade 3 or 4) injuries requiring surgical intervention