Commercially manufactured spacers for the treatment of periprosthetic joint infection of the hip.

BACKGROUND: Periprosthetic joint infection remains a common and serious complication after hip arthroplasty. To improve function and patient comfort after joint removal in two-stage revision, commercially manufactured spacers for the hip joint allow retention of the anatomical joint geometry thereby limiting soft tissue contraction and allow mobilization. INDICATIONS: Periprosthetic joint infection of the hip, septic arthritis with severe destruction of the hip cartilage and/or bone requiring arthroplasty. CONTRAINDICATIONS: Allergies to polymethylmethacrylate (PMMA) or antibiotics, severe hip dysplasia with insufficient cranial support, incompliant patient, large osseous defect of the acetabulum, insufficient metaphyseal/diaphyseal support of the femoral bone, resistance of the microbiological pathogen to spacer-inert antibiotic medication, inability to perform primary wound closure requiring temporary open-wound therapy. SURGICAL TECHNIQUE: Preoperative templating on radiograph; removal of joint prosthesis and thorough debridement with removal of all foreign material; trial spacer selection and insertion and trial reduction of the joint, fixing the spacer with PMMA to the proximal femur, final reduction, radiograph and stability test. RESULTS: Data were analyzed from patients treated between 2016 and 2021. In all, 20 patients were treated with preformed spacers and 16 with custom-made spacers. Pathogens were detected in 23 of the 36 cases (64%). Polymicrobial infections were present in 8 of 36 cases (22%). In patients who received preformed spacers, there were 6 cases of spacer-related complications (30%). Of the 36 patients (83%), 30 were reimplanted with a new implant; 3 patients died due to septic or other complications before reimplantation (8%). Average follow-up was 20.2 months after reimplantation. There were no major differences between the two groups of spacers. Patient comfort was not measured.

Treatment of partial rotator cuff lesions is associated with a higher frequency of post-operative shoulder stiffness. A prospective investigation on the role of surgery-related risk factors for this complication.

PURPOSE: Post-operative shoulder stiffness (SS) is a common complication after arthroscopic rotator cuff (RC) repair. The aim of this prospective study is to evaluate the role of surgical risk factors in the development of this complication, with special focus on the characteristics of the RC tears. METHODS: Two-hundred and twenty patients who underwent arthroscopic RC repair for degenerative posterosuperior RC tears were included. Surgery-related risk factors for development of post-operative SS belonging to the following five categories were documented and analyzed: previous surgery, RC tear characteristics, hardware and repair type, concomitant procedures, time and duration of surgery. The incidence of post-operative SS was evaluated according to the criteria described by Brislin and colleagues. RESULTS: The incidence of post-operative SS was 8.64%. The treatment of partial lesions by tear completion and repair technique was significantly associated with development of post-operative SS (p = 0.0083, pc = 0.04). A multivariate analysis revealed that treatment of partial lesions in patients younger than 60 years was associated to a higher risk of developing post-operative SS (p = 0.007). Previously known pre-operative risk factors such as female sex and younger age were confirmed. No other significant associations were documented. CONCLUSION: The treatment of partial lesions of the RC may lead to a higher risk of post-operative SS than the treatment of complete lesions, in particular in patients younger than 60 years. Possible explanations of this finding are the increased release of pro-inflammatory cytokines caused by the additional surgical trauma needed to complete the lesion and the different pain perception of the subgroup of patients who require surgical treatment already for partial tears. EVIDENCE: A higher risk of post-operative SS should be expected after tear completion and repair of partial lesions, especially in young patients. Appropriate pre-operative counseling and post-operative rehabilitation should be considered when approaching this subgroup of RC tears. LEVEL OF EVIDENCE: Prognostic study, level II.

Synovial Complement Factors in Patients with Periprosthetic Joint Infection after Undergoing Revision Arthroplasty of the Hip or Knee Joint.

The role and diagnostic value of the synovial complement system in patients with low-grade periprosthetic joint infection (PJI) are unclear. We sought to evaluate, for the first time, the usefulness of synovial complement factors in these patients by measuring the individual synovial fluid levels of complement factors (C1q, C3b/iC3b, C4b, C5, C5a, C9, factor B, factor D, factor H, factor I, properdin, and mannose-binding lectin [MBL]). The patients (n = 74) were classified into septic (n = 28) and aseptic (n = 46). Receiver-operator characteristic curves and a multiple regression model to determine the feasibility of a combination of the tested cytokines to determine the infection status were calculated. The synovial fluid levels of C1q, C3b/C3i, C4b, C5, C5a, MBL, and properdin were significantly elevated in the PJI group. The best sensitivity and specificity was found for C1q. The multiple regression models revealed that the combination of C1q, C3b/C3i, C4b, C5, C5a, and MBL was associated with the best sensitivity (83.3%) and specificity (79.2%) for a cutoff value of 0.62 (likelihood ratio: 4.0; area under the curve: 0.853). Nevertheless, only a combined model showed acceptable results. The expression patterns of the complement factors suggested that PJI activates all three pathways of the complement system.

Postoperative Medical Complications and Intermediate Care Unit/Intensive Care Unit Admission in Joint Replacement Surgery: A Prospective Risk Model.

BACKGROUND: Postoperative complications are the main consumers of technical, medical, and human resources. Especially in the field of elective joint replacement surgery, a specialized, easy-to-obtain, and cost-efficient preoperative stratification and risk-estimation model is missing. METHODS: With preoperatively surveyed patient parameters, we identified the most relevant parameters to predict postoperative medical complications. We devised a prospective risk model, measuring the individual probability for intermediate care unit (IMC) or intensive care unit (ICU) admission. The study includes all patients (n = 649) treated with primary or revision total knee arthroplasty in our clinic from 2008 to 2012. RESULTS: The association between general comorbidity scores and mortality risk is well known. Among different comorbidity scores, the Charlson Comorbidity Index is not only relevant for overall postoperative complications (odds ratios [OR] = 2.20) but also predictive of specific complications such as the postoperative need for blood transfusion (OR = 1.94) and unexpected adverse events (OR = 1.74). Considering adverse events, c-reactive protein and leukocyte levels are also highly relevant. Upon predicting a necessary postoperative transfer to an IMC or ICU, the preoperative hemoglobin level, the Charlson Comorbidity Index, and the Index of Coexistent Disease stood out. The latter indicates an increased rate for an IMC/ICU stay by 341% per point. Condensing the most influential predictors, the probability for postoperative IMC/ICU transfer can be calculated for each individual patient. Using the routinely assessed patient's variables, no steadier prediction is possible. CONCLUSION: The introduced risk-estimation model offers a specialized preoperative resource-stratification method in knee joint replacement surgery. It condenses the most influential, individual risk factors to avoid clinical test redundancy and improve resource efficiency and presurgical care planning. A prospective follow-up study could help validating the risk model in clinical routine.