Aims To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty. Methods We retrospectively reviewed 639 subjects, aged 45 to 79 years, in the Osteoarthritis Initiative (OAI) study, who had symptomatic knees with Kellgren and Lawrence grade 2 to 4. Knees were categorized as neutral, valgus, and varus knees by measuring hip-knee-angles on hip-knee-ankle radiographs. Femorotibial JSW was measured on posteroanterior SF radiographs using a special software. The femorotibial compartment was divided into 16 subregions, and MR-tomographic measurements of cartilage volume, thickness, and subchondral bone area were documented. Linear regression with adjustment for age, sex, body mass index, and Kellgren and Lawrence grade was used. Results We studied 345 neutral, 87 valgus, and 207 varus knees. Radiological JSW narrowing was significantly (p < 0.01) associated with cartilage volume and thickness in medial femorotibial compartment in neutral ( r = 0.78, odds ratio (OR) 2.33) and varus knees ( r = 0.86, OR 1.92), and in lateral tibial subregions in valgus knees ( r = 0.87, OR 3.71). A significant negative correlation was found between JSW narrowing and area of subchondral bone in external lateral tibial subregion in valgus knees ( r = −0.65, p < 0.01) and in external medial tibial subregion in varus knees ( r = −0.77, p < 0.01). No statistically significant correlation was found in anterior and posterior subregions. Conclusion SF radiographs can be potentially used for initial detection of cartilage degeneration as assessed by MRI in medial and lateral but not in anterior or posterior subregions. Cite this article: Bone Joint Res 2021;10(3):173–187.

Introduction: Periprosthetic joint infections (PJI) following primary arthroplasty continue to be a serious complication, despite advances in diagnostics and treatment. Two-stage revision arthroplasty has been commonly used as the gold standard for the treatment of PJI. However, much discussion persists regarding the interim of the two-stage procedure and the optimal timing of reimplantation. Serology markers have been proposed as defining parameters for a successful reimplantation. The objective of this matched-pair analysis was to assess the role of serum C-reactive protein (CRP) and white blood cell count (WBC) in determining infection eradication and proper timing of reimplantation. We investigated the delta (∆) change in CRP and WBC values prior to both stages of two-stage revision arthroplasty as a useful marker of infection eradication. Methods: We analyzed 39 patients and 39 controls, matched by propensity score matching (BMI, age, ASA-classification), with a minimum follow-up of 24 months and treated with a two-stage revision THA or TKA in our institution. Data of serum CRP and WBC values were gathered at two selected time points: prior to the explantation of the implant (preexplantation) and following the completion of antibiotic treatment regimen, both systemic and with a drug-eluting cement spacer (prereimplantation). Patient records were reviewed electronically for preexisting comorbidities, overall health status, synovial fluid cultures, inflammatory serologies, revision surgeries, and recurrent or persistent infection based on the modified Musculoskeletal Infection Society criteria. Patient demographics, ∆CRP, ∆WBC, and time interval to reimplantation were statistically analyzed using receiver operator curves (ROC), Pearson’s correlation coefficient, Levene’s test, and Student’s t-test. Results: Infection-free patients exhibited higher mean CRP and WBC than did patients who were reinfected at both time points. When comparing preexplantation with prereimplantation values, the median ∆CRP was 9.48 mg/L (interquartile range (IQR) 2.3–36.6 mg/L) for patients who did not develop a reinfection versus 2.74 mg/L (IQR 1.4–14.2 mg/L) for patients who developed reinfection (p = 0.069). The median ∆WBC was 1.5 × 109/L (IQR 0.6–4.0 × 109/L) for patients who remained infection-free versus 1.2 × 109/L (IQR 0.8–2.2 109/L) for patients who developed reinfection (p = 0.072). Analysis of areas under the curve (AUC) using ROC demonstrated poor prediction of persistent infection by ∆CRP (AUC = 0.654) and ∆WBC (AUC = 0.573). Although a highly significant correlation was found between the interim interval and infection persistence (r = 0.655, p < 0.01), analysis using ROC failed to result in a specific threshold time to reimplantation above which patients are at significantly higher risk for reinfection (AUC = 0.507). Conclusion: No association could be determined between the delta change in serum CRP and WBC before and after two-stage revision arthroplasty for PJI and reinfection risk. Even though inflammatory serologies demonstrate a downtrending pattern prior to reimplantation, the role of CRP and WBC in determining the optimal timing of reimplantation seems to be dispensable. Planning a second-stage reimplantation requires assessing multiple variables rather than relying on specific numeric changes in these inflammatory marker values.

No abstract

Hip hemiarthroplasty is considered the treatment of choice for displaced femoral neck fractures in elderly less active patients. One important complication of this procedure is an intraoperative periprosthetic femur fracture (IPF), which may lead to poor functional outcome and may increase morbidity and mortality. Our primary aim in this study is to compare between Austin-Moore and Corail prosthesis regarding IPFs. Our secondary aim is to assess patient and surgical technique related risk factors for the development of this complication. Inclusion criteria included patients older than 65 years of age who had a displaced femoral neck fracture and were operated for hip hemiarthroplasty between the years 2014–2018. Patient-specific data was collected retrospectively including age, gender, comorbidities, pre-injury ambulatory status, duration of surgery, surgical approach, use of Austin-Moore or Corail prosthesis, surgeon’s experience and type of anesthesia applied. In addition, radiographs were reviewed for measurement of calcar to canal ratio (CDR) and classification of Dorr canal type. 257 patients with an average age of 83.7 years were enrolled in the study. 118 patients (46%) were treated with an Austin-Moore prosthesis, while 139 (54%) were treated with a Corail prosthesis. A total of 22 patients (8.6%) had intraoperative fractures. Fracture prevalence was significantly higher in the Corail group compared with the Austin-Moore group (12.2% vs. 4.2%, p = 0.025). The majority of patients had a Dorr A type femoral canal, while the rest had Dorr B type canal (70% vs. 30%). There was no difference in fracture prevalence between Dorr A and B canal type patients. We didn’t find any significant risk factor for developing an IPF, neither patient wise (age, gender, and comorbidities) nor surgical technique related (surgical approach, type of anesthesia, and surgeon’s experience). Intraoperative periprosthetic fracture prevalence was significantly higher in the Corail patient group compared with the Austin-Moore group. This may be an important advantage of the Austin-Moore prosthesis over the Corail prosthesis.