The souter-strathclyde elbow prosthesis in rheumatoid patients : an in-depth clinical, radiological and biomechanical analysis

The first goal of this thesis was to evaluate the results of primary elbow prostheses used in rheumatoid patients. A systematic review on elbow prostheses is given, with special emphasis on the complication rates (Chapter 2). The second goal was to evaluate the long-term results of 204 primary Souter-Strathclyde total elbow prostheses in rheumatoid arthritis patients at the Leiden University Medical Center (Chapter 3). Highlights on the surgical technique are presented (Chapter 4). The third goal was to assess the reasons for failure of the Souter-Strathclyde total elbow prosthesis. Potential failure mechanisms might be related to previous surgery, prosthetic size and position and bone stock. In Chapter 5 to 8 these aspects are presented. Three failure mechanisms are evalated more closely: 1. Previous surgery Some rheumatoid patients with synovitis of the elbow joint first undergo a synovectomy before replacement therapy is chosen. It was hypothesized that previous open synovectomy could harm the outcome of primary elbow prostheses because of scare tissue with increased chance on infection and limited range of motion. 2.Prosthetic position The prosthetic alignment was determined by measuring conventional radiographs during the follow-up in a standardized manner. Since radiolucent lines (RLLs) are the radiological indication in the loosening process, the elbow components position in the bone was related to the development and progression of these RLLs. It was hypothesized that prosthetic position did influence the loosening process. Radiostereometric analysis (RSA) is used for accurate migration measurements during the follow-up of prostheses (K_rrholm 1994, Ryd 1995, Valstar 2002). Aseptic loosening starts with early onset prosthesis migration. Evaluation of migration patterns with RSA during long term follow-up might elucidate this process. 3.Biomechanical prosthesis-bone interface failure The size of the component, related to the bone size, on torsional stiffness and torque to failure was tested in a cadaveric study design. The hypothesis that larger components give more torque strength was investigated. Finally, the last goal was to evaluate the outcome of revision surgery after failure of a primary Souter-Strathclyde total elbow prosthesis (Chapter 9).UBL - phd migration 201

Wound drainage after arthroplasty and prediction of acute prosthetic joint infection: prospective data from a multicentre cohort study using atelemonitoring app

Background: Differentiation between uncomplicated and complicated postoperative wound drainage after arthroplasty is crucial to prevent unnecessary reoperation.Prospective data about the duration and amount of postoperative wounddrainage in patients with and without prosthetic joint infection (PJI) are currently absent.Methods: A multicentre cohort study was conducted to assess the duration and amount of wound drainage in patients after arthroplasty. During 30 postoperative days after arthroplasty, patients recorded their wound status in a previously developed wound care app and graded the amount of wound drainage on a 5-point scale. Data about PJI in the follow-up period were extracted from the patient files.Results: Of the 1019 included patients, 16 patients (1.6 %) developed a PJI. Minor wound drainage decreased from the first to the fourth postoperative week from 50 % to 3 %. Both moderate to severe wound drainage in the third week and newly developed wound drainage in the second week after a week without drainage were strongly associated with PJI (odds ratio (OR) 103.23, 95 % confidence interval (CI)26.08 to 408.57, OR 80.71, 95 % CI 9.12 to 714.52, respectively). Thepositive predictive value (PPV) for PJI was 83 % for moderate to heavy wound drainage in the third week. Conclusion: Moderate to heavy wound drainage and persistent wound drainage were stronglyassociated with PJI. The PPV of wound drainage for PJI was high for moderate to heavy drainage in the third week but was low for drainage in the first week. Therefore, additional parameters are needed to guide the decision to reoperate on patients for suspected acute PJI.Orthopaedics, Trauma Surgery and Rehabilitatio

The souter-strathclyde elbow prosthesis in rheumatoid patients : an in-depth clinical, radiological and biomechanical analysis

The first goal of this thesis was to evaluate the results of primary elbow prostheses used in rheumatoid patients. A systematic review on elbow prostheses is given, with special emphasis on the complication rates (Chapter 2). The second goal was to evaluate the long-term results of 204 primary Souter-Strathclyde total elbow prostheses in rheumatoid arthritis patients at the Leiden University Medical Center (Chapter 3). Highlights on the surgical technique are presented (Chapter 4). The third goal was to assess the reasons for failure of the Souter-Strathclyde total elbow prosthesis. Potential failure mechanisms might be related to previous surgery, prosthetic size and position and bone stock. In Chapter 5 to 8 these aspects are presented. Three failure mechanisms are evalated more closely: 1. Previous surgery Some rheumatoid patients with synovitis of the elbow joint first undergo a synovectomy before replacement therapy is chosen. It was hypothesized that previous open synovectomy could harm the outcome of primary elbow prostheses because of scare tissue with increased chance on infection and limited range of motion. 2.Prosthetic position The prosthetic alignment was determined by measuring conventional radiographs during the follow-up in a standardized manner. Since radiolucent lines (RLLs) are the radiological indication in the loosening process, the elbow components position in the bone was related to the development and progression of these RLLs. It was hypothesized that prosthetic position did influence the loosening process. Radiostereometric analysis (RSA) is used for accurate migration measurements during the follow-up of prostheses (K_rrholm 1994, Ryd 1995, Valstar 2002). Aseptic loosening starts with early onset prosthesis migration. Evaluation of migration patterns with RSA during long term follow-up might elucidate this process. 3.Biomechanical prosthesis-bone interface failure The size of the component, related to the bone size, on torsional stiffness and torque to failure was tested in a cadaveric study design. The hypothesis that larger components give more torque strength was investigated. Finally, the last goal was to evaluate the outcome of revision surgery after failure of a primary Souter-Strathclyde total elbow prosthesis (Chapter 9)

Minor influence of humeral component size on torsional stiffness of the Souter-Strathclyde total elbow prosthesis

The use of Souter-Strathclyde total elbow prostheses is a well-studied replacement therapy for reconstruction of the elbow, but loosening of the humeral component is still of concern at long-term follow-up. In this study we looked at the effect of humeral component size and bone mineral density with respect to the bone size, torsional stiffness and torque to failure in cadaveric bones. Fourteen cadaveric humeri were available for testing purposes and four different humeral component size categories were used. First, we calculated the bone quality using dual-energy X-ray absorptiometry (DEXA). The torsional stiffness of the prosthetic humeri was measured during two mechanical tests: Firstly, the applied torque was recorded during a torsion fatigue test. The change of torsional stiffness between the tenth and last cycle was calculated. Secondly, a simple torsion test was performed and the torque to failure was recorded. No significant differences in outcome were seen between sizes of humeral components, even after correction for the bone size. Torsional stiffness and torque to failure were significantly correlated with bone mineral density and not with component size. In conclusion, bone quality seems to be a major eminent factor in the fixation of the humeral component in elbow replacement surgery

Migration of the humeral component of the Souter-Strathclyde elbow prosthesis A LONG-TERM RSA STUDY

Mechanical loosening which begins with early-onset migration of the prosthesis is the major reason for failure of the Souter-Strathclyde elbow replacement. In a prospective study of 18 Souter-Strathclyde replacements we evaluated the patterns of migration using roentgen stereophotogrammetric analysis. We had previously reported the short-term results after a follow-up of two years which we have now extended to a mean follow-up of 8.2 years (1 to 11.3). Migration was assessed along the co-ordinal axes and overall micromovement was expressed as the maximum total point movement. The alignment of the prosthesis and the presence of radiolucent lines were examined on conventional standardised radiographs. All the humeral components showed increased and variable patterns of migration at the extended follow-up and four humeral components were revised. The maximum total point movement at two years in the revised prostheses was 1.8 mm (SD 1.0) and in the non-revised 0.7 mm (SD 0.5, p = 0.01). Most humeral components migrated into external rotation resulting in an anterior and varus tilt. The ulnar components remained stable.Study of the normal and pathological locomotory syste

Migration of the humeral component of the Souter-Strathclyde elbow prosthesis A LONG-TERM RSA STUDY

Mechanical loosening which begins with early-onset migration of the prosthesis is the major reason for failure of the Souter-Strathclyde elbow replacement. In a prospective study of 18 Souter-Strathclyde replacements we evaluated the patterns of migration using roentgen stereophotogrammetric analysis. We had previously reported the short-term results after a follow-up of two years which we have now extended to a mean follow-up of 8.2 years (1 to 11.3). Migration was assessed along the co-ordinal axes and overall micromovement was expressed as the maximum total point movement. The alignment of the prosthesis and the presence of radiolucent lines were examined on conventional standardised radiographs. All the humeral components showed increased and variable patterns of migration at the extended follow-up and four humeral components were revised. The maximum total point movement at two years in the revised prostheses was 1.8 mm (SD 1.0) and in the non-revised 0.7 mm (SD 0.5, p = 0.01). Most humeral components migrated into external rotation resulting in an anterior and varus tilt. The ulnar components remained stable

No differences in cost-effectiveness and short-term functional outcomes between cemented and uncemented total knee arthroplasty

Background There is an ongoing debate regarding optimal fixation of total knee arthroplasty (TKA), however cost has not been addressed as profoundly. Therefore, the current study primarily aimed to compare costs and cost-effectiveness 1 year after cemented or uncemented TKA. A secondary objective was to compare short-term functional outcomes between both groups. Methods A posthoc prospective observational multicenter cohort study of 60 cemented and 50 uncemented Low Contact Stress (LCS) knee systems. Outcome was evaluated using the EuroQol5D-3 L (EQ5D) index, in order to calculate quality adjusted life years (QALYs). Total costs were calculated considering direct costs within the hospital setting (inpatient cost) as well as direct and indirect costs outside the hospital. Cost-effectiveness (total costs per QALY), Oxford Knee Score (OKS) and Numeric Rating Scale (NRS) were compared between cemented and uncemented cases at 1 year after surgery. HealthBASKET project, a micro-costing approach, represents the Dutch costs and situation and was used to calculate hospital stay. (In) direct costs outside the healthcare (medical cost and productivity cost) were determined using two validated questionnaires. Results Median costs per QALY were similar between cemented and uncemented TKA patients (euro16,269 and euro17,727 respectively;p = 0.50). Median OKS (44 and 42;p = 0.79), EQ5D (0.88 and 0.90;p = 0.82) and NRS for pain (1.0 and 1.0;p = 0.48) and satisfaction (9.0 and 9.0;p = 0.15) were also comparable between both groups. Conclusion For this type of knee implant (LCS), inpatient hospital costs and costs after hospitalization were comparable between groups.Orthopaedics, Trauma Surgery and Rehabilitatio

Long-term outcomes of slipped capital femoral epiphysis treated with in situ pinning

Optimising joint reconstruction management in arthritis and bone tumour patient

Effectiveness of different antimicrobial strategies for staphylococcal prosthetic joint infection: results from a large prospective registry-based cohort study

Outcome of staphylococcal PJI after DAIR or 1-stage exchange was similar between patients treated with a long-term rifampicin combination therapy strategy and patients treated with only 5 days of rifampicin combination therapy followed by clindamycin or flucloxacillin monotherapy.Background Treatment of staphylococcal prosthetic joint infection (PJI) usually consists of surgical debridement and prolonged rifampicin combination therapy. Tailored antimicrobial treatment alternatives are needed due to frequent side effects and drug-drug interactions with rifampicin combination therapy. We aimed to assess the effectiveness of several alternative antibiotic strategies in patients with staphylococcal PJI. Methods In this prospective, multicenter registry-based study, all consecutive patients with a staphylococcal PJI, treated with debridement, antibiotics and implant retention (DAIR) or 1-stage revision surgery between January 1, 2015 and November 3, 2020, were included. Patients were treated with a long-term rifampicin combination strategy (in 2 centers) or a short-term rifampicin combination strategy (in 3 centers). Antimicrobial treatment strategies in these centers were defined before the start of the registry. Patients were stratified in different groups, depending on the used antimicrobial strategy. Cox proportional hazards models were used to compare outcome between the groups. Results Two hundred patients were included and stratified in 1 long-term rifampicin group (traditional rifampicin combination therapy) or 1 of 3 short-term rifampicin groups (clindamycin or flucloxacillin or vancomycin monotherapy, including rifampicin for only 5 postoperative days). Adjusted hazard ratios (aHRs) for failure in patients treated with short-term rifampicin and either flucloxacillin or clindamycin were almost equal to patients treated with long-term rifampicin combination therapy (aHR = 1.21; 95% confidence interval, .34-4.40). Conclusions A short-term rifampicin strategy with either clindamycin or flucloxacillin and only 5 days of rifampicin was found to be as effective as traditional long-term rifampicin combination therapy. A randomized controlled trial is needed to further address efficacy and safety of alternative treatment strategies for staphylococcal PJI

Effectiveness of Different Antimicrobial Strategies for Staphylococcal Prosthetic Joint Infection: Results From a Large Prospective Registry-Based Cohort Study

Outcome of staphylococcal PJI after DAIR or 1-stage exchange was similar between patients treated with a long-term rifampicin combination therapy strategy and patients treated with only 5 days of rifampicin combination therapy followed by clindamycin or flucloxacillin monotherapy.Background Treatment of staphylococcal prosthetic joint infection (PJI) usually consists of surgical debridement and prolonged rifampicin combination therapy. Tailored antimicrobial treatment alternatives are needed due to frequent side effects and drug-drug interactions with rifampicin combination therapy. We aimed to assess the effectiveness of several alternative antibiotic strategies in patients with staphylococcal PJI. Methods In this prospective, multicenter registry-based study, all consecutive patients with a staphylococcal PJI, treated with debridement, antibiotics and implant retention (DAIR) or 1-stage revision surgery between January 1, 2015 and November 3, 2020, were included. Patients were treated with a long-term rifampicin combination strategy (in 2 centers) or a short-term rifampicin combination strategy (in 3 centers). Antimicrobial treatment strategies in these centers were defined before the start of the registry. Patients were stratified in different groups, depending on the used antimicrobial strategy. Cox proportional hazards models were used to compare outcome between the groups. Results Two hundred patients were included and stratified in 1 long-term rifampicin group (traditional rifampicin combination therapy) or 1 of 3 short-term rifampicin groups (clindamycin or flucloxacillin or vancomycin monotherapy, including rifampicin for only 5 postoperative days). Adjusted hazard ratios (aHRs) for failure in patients treated with short-term rifampicin and either flucloxacillin or clindamycin were almost equal to patients treated with long-term rifampicin combination therapy (aHR = 1.21; 95% confidence interval, .34-4.40). Conclusions A short-term rifampicin strategy with either clindamycin or flucloxacillin and only 5 days of rifampicin was found to be as effective as traditional long-term rifampicin combination therapy. A randomized controlled trial is needed to further address efficacy and safety of alternative treatment strategies for staphylococcal PJI.Immunogenetics and cellular immunology of bacterial infectious disease