potw

Paper of the week: Periprosthetic joint infection in aseptic total hip arthroplasty revision.

Paper of the week: Periprosthetic joint infection in aseptic total hip arthroplasty revision. Renard G, Laffosse JM, Tibbo M, Lucena T, Cavaignac E, Rouvillain JL, Chiron P, Severyns M, Reina N. Int Orthop. 2019 Jun 25. doi: 10.1007/s00264-019-04366-2.

Summary by Dr Sreeram Penna

Aim of this retrospective study was to evaluate incidence of occult infection in presumed aseptic total hip arthroplasty revisions and to identify associated risk factors. Researchers retrospectively reviewed all patients who underwent aseptic total hip revision between 2009 and 2013. Total of 523 cases (498 patients) were identified. The main indications for revision were aseptic loosening(283/523, 54%), instability (91/523, 17%), periprosthetic fracture (56/523, 11%), wear and osteolysis (35/523, 7%), unexplained pain (12/523, 2%), implant fracture (13/523, 3%), and others (metallosis, squeaking, tumour, aseptic lymphocyte-dominated vascular-associated lesion, psoas impingement)(33/523, 6%). Unexpected positive cultures (UPC) were found in 78 cases (15%). Of these 58 cases were monomicrobial, and 20 cases polymicrobial. Further review identified 36 cases (7%) with positive cultures as true infections and other 42 cases (8%) as contaminants. Infection was identified in 15/91 (16%) cases who underwent revision for instability. Similarly, incidence of infection was 12% in patients with periprosthetic fracture, 3.2% in aseptic loosening and 2.8% in polyethylene wear and osteolysis group. On further analysis researchers found statistically significant difference in early dislocation (with in 3 months) rates in infection group (31%) compared to non-infection group (7%) (p<0.001).

potw

Paper of the week: Use of incisional vacuum-assisted closure in the prevention of postoperative infection in high-risk patients who underwent spine surgery: a proof-of-concept study.

Paper of the week: Use of incisional vacuum-assisted closure in the prevention of postoperative infection in high-risk patients who underwent spine surgery: a proof-of-concept study. Dyck BA, Bailey CS, Steyn C, Petrakis J, Urquhart JC, Raj R, Rasoulinejad P. J Neurosurg Spine. 2019 May 10:1-10. doi: 10.3171/2019.2.SPINE18947.

Summary by Dr Sreeram Penna

In this study researchers wanted to see if use of incisional vacuum assisted closure resulted in lower surgical site infections in high-risk patients who underwent spine surgery. A total of 64 patients were included In this proof of concept study. 21 patients received incisional vacuum assisted closure and and 43 diagnosis matched patients received standard dressings. Patients undergoing vacuum assisted closure met criteria for high risk of infection including posterior open surgery across the cervicothoracic junction; thoracic kyphosis due to metastatic disease; high-energy trauma; or multilevel revision reconstructive surgery. They also met one or more co-morbidity criteria, including body mass index 35 more, body mass index below 18.5, diabetes, previous radiation at surgical site, chemotherapy, steroid use, bedridden state, large traumatic soft-tissue disruption, or immunocompromised state. Although not statistically significant (p=0.314) vacuum assisted closure had lower infection rate 10% (2/21) compared to standard dressings 21% (9/43). This study demonstrates possible utility of vacuum assisted closure to reduce surgical site infections in high risk spine surgery patients.

potw

Paper of the week: Stopping antibiotics after surgical amputation in diabetic foot and ankle infections-A daily practice cohort.

Paper of the week: Stopping antibiotics after surgical amputation in diabetic foot and ankle infections-A daily practice cohort. Rossel A, Lebowitz D, Gariani K, Abbas M, Kressmann B, Assal M, Tscholl P, Stafylakis D, Uçkay I. Endocrinol Diabetes Metab. 2019 Feb 6;2(2): e00059. doi: 10.1002/edm2.59. eCollection 2019 Apr.

Summary by Dr. Sreeram Penna

This is a retrospective cohort study included adult diabetic foot and ankle infection patients who underwent amputation. Researchers studied benefits of continuing antibiotics after amputation. Overall 482 episodes in 258 patients were included in the study. Osteomyelitis was diagnosed in 239 cases. Median duration of antibiotics post amputation was 7 days. In 109 episodes antibiotic was discontinued immediately after surgery. Using multivariate analysis researchers concluded that neither duration of post-operative antibiotics (Hazards ratio: 1.0; CI 0.99 – 1.01) nor immediate discontinuation (Hazards ratio: 0.9; CI 0.5 -1.5) altered overall failure rate. Researchers also stressed importance of amputation with clear margins.

potw

Paper of the week: Percutaneous CT guided bone biopsy for suspected osteomyelitis: Diagnostic yield and impact on patient’s treatment change and recovery.

Paper of the week: Percutaneous CT guided bone biopsy for suspected osteomyelitis: Diagnostic yield and impact on patient’s treatment change and recovery. Hoang D, Fisher S, Oz OK, La Fontaine J, Chhabra A. Eur J Radiol. 2019 May;114:85-91. doi: 10.1016/j.ejrad.2019.01.032.

Summary by Dr. Sreeram Penna

This retrospective audit was done to assess the utility of CT guided bone biopsy for suspected osteomyelitis. 115 patients were included in the study. Of these 40 patients had systemic symptoms of toxemia while 75 had only localized symptoms at the time of presentation. The most common bone biopsy site was the sacrum/ischium (49), followed by the spine (35), extremities (32), and the chest wall (2). Upon culture of the biopsy sample, only 24 were positive (21%). Of these positive cultures, 19 out of 24 have grown different organism compared to blood cultures. Common organism grown in biopsy cultures were Staphylococcus aureus (29.2%) followed by Escherichia coli (12.5%). Of the biopsies taken only 36 had histology performed. Of these 11 (30.6%) showed evidence of inflammation or osteomyelitis, 12 (33.3%) showed no evidence and 13 (38.1%) were inconclusive. In conclusion, this study shows a low yield of positive cultures or histology following bone biopsy for osteomyelitis.

potw

Paper of the week: Perioperative Antibiotic Prophylaxis in Total Joint Arthroplasty: A Single Dose Is as Effective as Multiple Doses.

Paper of the week: Perioperative Antibiotic Prophylaxis in Total Joint Arthroplasty: A Single Dose Is as Effective as Multiple Doses. Tan TL, Shohat N, Rondon AJ, Foltz C, Goswami K, Ryan SP, Seyler TM, Parvizi J. J Bone Joint Surg Am. 2019 Mar 6;101(5):429-437. doi: 10.2106/JBJS.18.00336.

Summary by Dr. Sreeram Penna

This study is a retrospective study comparing the incidence of periprosthetic joint infection (PJI) in primary joint arthroplasty who had a single dose of prophylactic antibiotic versus multiple doses at the time of surgery. A total of 20,682 patients were included in the study. Of these 4523 had a single dose and 16159 had multiple doses. All patients who had an infection within 1 year were identified and confirmed with MSIS criteria. In addition, researchers calculated and recorded the patient’s preoperative infection risk score.

The results showed that overall rates of PJI were 0.60% (27/4523) in patients receiving a single dose and 0.88% (142/16159) in patients receiving multiple prophylactic antibiotic doses. Researchers also noted that both patient groups were significantly different in various demographics (age, sex, BMI, comorbidities, ASA score, length of stay). Researchers then performed multivariate analysis after controlling for potential confounders and found no significant difference between the PJI rate between both groups. They have also used propensity score matching with preoperative risk score and found no increase in PJI rate in patients with a single dose of prophylactic antibiotic at the primary procedure.

Although this study has limitations of being retrospective study and statistically significant differences between two groups, it provides the necessary evidence to support the use of single-dose prophylactic antibiotic during primary joint arthroplasty.