An overview of the current diagnostic approach to Periprosthetic Joint Infections.

The diagnosis of periprosthetic joint infections (PJI) presents a formidable challenge to orthopaedic surgeons due to its complex and diverse manifestations. Accurate diagnosis is of utmost importance, as even mild pain following joint replacement surgery may indicate PJI in the absence of a definitive gold standard diagnostic test. Numerous diagnostic modalities have been suggested in the literature, and international societies have continually updated diagnostic criteria for this debilitating complication. This review article aims to comprehensively examine the latest evidence-based approaches for diagnosing PJI. Through a thorough analysis of current literature, we explore promising diagnostic strategies that have demonstrated effectiveness in identifying PJI. These strategies encompass the utilization of laboratory markers, such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), alongside imaging techniques such as magnetic resonance imaging (MRI) and leukocyte scintigraphy. Additionally, we highlight the importance of synovial fluid analysis, including the potential role of alpha-defensin as a biomarker, and examine evolving international diagnostic criteria to standardize and improve diagnostic accuracy.

Periprosthetic Distal Femoral Fractures Around a Total Knee Arthroplasty: a Meta-analysis Comparing Locking compression Plating and Retrograde Intramedullary Nailing.

Purpose: The number of total knee replacements (TKRs) performed per year has been increasing annually and it is estimated that by 2030 demand would reach 3.48 million procedures per year in the United States Of America. The prevalence of periprosthetic fractures (PPFs) around TKRs has followed this trend with incidences ranging from 0.3% to 3.5%. Distal femoral PPFs are associated with significant morbidity and mortality. When there is sufficient bone stock in the distal femur and a fracture pattern conducive to fixation, locking compression plating (LCP) and retrograde intramedullary nailing (RIMN) are commonly used fixation strategies. Conversely, in situations with loosening and deficient bone stock, a salvage procedure such as a distal femoral replacement is recognized as an alternative. This meta-analysis investigates the rates of non-union, re-operation, infection, and mortality for LCPs and RIMNs when performed for distal femoral PPFs fractures around TKRs. Method: A search was conducted to identify articles relevant to the management of distal femoral PPFs around TKRs in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Articles meeting the inclusion criteria were then assessed for methodological quality using the methodological items for non-randomised studies (MINORS) criteria. Articles were reviewed, and data were compiled into tables for analysis. Results: 10 articles met the inclusion criteria, reporting on 528 PPFs. The overall incidence of complications was: non-union 9.4%, re-operation 12.9%, infection 2.4%, and mortality 5.5%. This meta-analysis found no significant differences between RIMN and LCP in rates of non-union (9.2% vs 9.6%) re-operation (15.1% vs 11.3%), infection (2.1% vs 2.6%), and mortality (6.0% vs 5.2%), respectively. Conclusion: This meta-analysis demonstrated no significant difference in rates of non-union, re-operation, infection, and mortality between RIMN and LCP and both remain valid surgical treatment options.

Total Knee Arthroplasty in Patients Who Have Skeletal Dysplasia: A Center's Experience with a Mean 9 Year Follow-Up.

BACKGROUND: Total knee arthroplasty (TKA) in patients who have skeletal dysplasia is a technically challenging surgery due to deformity, joint contracture, and associated co-morbidities. Patients presenting with this condition have traditionally been treated with conservative measures, leading to poor outcomes. The aim of this study was to follow up on patients who had skeletal dysplasia following total knee arthroplasty, specifically with regards to clinical outcomes. METHODS: A total of 31 knees (22 patients) with skeletal dysplasia that had undergone total knee arthroplasty in our institution were included in our study. The mean follow-up from index surgery was 110.3 months (range; 20 to 291). The type of dysplasia, implant used, and clinical outcomes with patient-reported outcome measures (PROMs) are presented. RESULTS: There were eight patients (36.3%) who had a diagnosis of achondroplasia, followed by multiple epiphyseal dysplasia (31.8%) and spondyloepiphyseal dysplasia (22.7%). There were fourteen men and eight women who had a mean age of 51 years (range, 28 to 73). Custom implants were required in twelve cases (38.7%), custom jigs were used in six cases (19.4%), and robotic assisted surgery was used in two (6.5%) total knee arthroplasties. Hinged prostheses were used in seventeen cases (54.8%), posterior stabilized in nine (29.0%), and cruciate retaining implants in five (16.1%). There was one patient who sustained an intra-operative medial tibial plateau fracture treated with concomitant open reduction and internal fixation. There was one revision that occurred during the follow-up period with a patella resurfacing for continued anterior knee pain. Post-operatively, Oxford knee scores improved on average by 12.2 points. The 10- and 20-year all-cause revision-free survival was 96.8 respectively. CONCLUSION: Despite the technical challenges and complexity associated with this unique patient cohort, we demonstrated excellent implant survivorship and clinical outcomes post-total knee arthroplasty with mid- to long-term follow up of over 20 years. We recommend pre-operative cross-sectional imaging for precise planning and implant templating with multidisciplinary team decision-making. Despite our results, functional outcomes remain inferior to primary arthroplasty within the general population, though we still recommend this treatment modality to appropriately counseled patients.

Hip Resurfacing Arthroplasty: Past, Present and Future.

The history of hip resurfacing arthroplasty (HRA) has faced numerous challenges and undergone decades of evolution in materials and methods. These innovations have been translated to the successes of current prostheses and represent a surgical and mechanical achievement. Modern HRAs now have long term outcomes with excellent results in specific patient groups as demonstrated in national joint registries. This article reviews the key moments in the history of HRAs with specific emphasis on the lessons learnt, current outcomes and future prospects.

Short- and Long-Term Outcomes in Patients With Lower Extremity Amputations Undergoing Total Hip and Knee Arthroplasty.

Background: Joint replacement following amputation is scarcely reported. The primary aim of this study was to evaluate patient-reported outcomes (PROMS) and revision rates among lower extremity amputees undergoing total hip (THA) or knee arthroplasty (TKA). Methods: This was a retrospective cohort analysis of lower extremity amputees undergoing THA/TKA between August 2002 and August 2022 in a single tertiary center. Demographic and clinical data were collected from prospectively populated surgical databases and patient electronic records. PROMS included Oxford Knee Score, Oxford Hip Score, and 5-level EuroQol 5-dimension questionnaires. Twenty-three TKAs and 21 THAs were performed in 38 patients. The mean age at arthroplasty procedures was 59.8 (24-87) years. The mean clinical follow-up duration for THA and TKA was 9.1 and 4.5 years, respectively. Seven TKAs and 6 THAs were ipsilateral to the amputated side. Results: The 10-year revision rates were 9.5% (2/21) and 5.9% (1/17) in the TKA and THA cohorts, respectively. TKA revisions occurred due to aseptic loosening. Six (26%) TKA cases experienced stump complications. Overall PROMS completion was 61.9% (13/21) and 64.7% (11/17) in TKA and THA patients, respectively. The average Oxford Hip Score/Oxford Knee Score of THA and TKA cohorts were 40.8 and 34.2, respectively. EuroQol 5-dimension questionnaire visual analog scores were higher in the THA cohort than those in the TKA cohort without statistical significance (59.1 vs 50.5, P = .214). The overall survival rate for the study was 94.7% at 5 years (36/38). Conclusions: TKA/THA in lower extremity amputees can be successful, with low revision rates and good prosthesis function. Potential pitfalls highlighted include prosthesis malalignment, postprocedural rehabilitation, and stump complications.

Periprosthetic distal femur fractures around total knee replacements: A comprehensive review.

With a growing number of patients undergoing total knee replacements globally, coupled with an elderly population, the incidence of periprosthetic fractures around total knee replacements is increasing. As such, this is a highly topical subject that is gaining increasing interest within the orthopaedic community. This review provides a narrative synthesis of the most contemporary literature regarding distal femoral periprosthetic fractures. We review the related epidemiology, initial patient evaluation, the evolution and relevance of the classification systems and treatment options, particularly related to endoprosthetics and hybrid fixation constructs. The latest orthopaedic evidence related to this topic has been included.

Ischial screw fixation can prevent cup migration in 3D-printed custom acetabular components for complex hip reconstruction.

INTRODUCTION: Custom acetabular components have become an established method of treating massive acetabular bone defects in hip arthroplasty. Complication rates, however, remain high and migration of the cup is still reported. Ischial screw fixation (IF) has been demonstrated to improve mechanical stability for non-custom, revision arthroplasty cup fixation. We hypothesize that ischial fixation through the flange of a custom acetabular component aids in anti-rotational stability and prevention of cup migration. METHODS: Electronic patient records were used to identify a consecutive series of 49 custom implants in 46 patients from 2016 to 2022 in a unit specializing in complex joint reconstruction. IF was defined as a minimum of one screw inserted into the ischium passing through a hole in a flange on the custom cup. The mean follow-up time was 30 months. IF was used in 36 cups. There was no IF in 13 cups. No difference was found between groups in age (68.9 vs. 66.3, P = 0.48), BMI (32.3 vs. 28.2, P = 0.11) or number of consecutively implanted cups (3.2 vs. 3.6, P = 0.43). Aseptic loosening with massive bone loss was the primary indication for revision. There existed no difference in Paprosky grade between the groups (P = 0.1). 14.2% of hips underwent revision and 22.4% had at least one dislocation event. RESULTS: No ischial fixation was associated with a higher risk of cup migration (6/13 vs. 2/36, X2 = 11.5, P = 0.0007). Cup migration was associated with an increased risk for all cause revision (4/8 vs. 3/38, X2 = 9.96, P = 0.0016, but not with dislocation (3/8 vs. 8/41, X2 = 1.2, P = 0.26). CONCLUSION: The results suggest that failure to achieve adequate ischial fixation, with screws passing through the flange of the custom component into the ischium, increases the risk of cup migration, which, in turn, is a risk factor for revision.

Synovial fluid fingerprinting in end-stage knee osteoarthritis: a novel biomarker concept.

AIMS: The lack of disease-modifying treatments for osteoarthritis (OA) is linked to a shortage of suitable biomarkers. This study combines multi-molecule synovial fluid analysis with machine learning to produce an accurate diagnostic biomarker model for end-stage knee OA (esOA). METHODS: Synovial fluid (SF) from patients with esOA, non-OA knee injury, and inflammatory knee arthritis were analyzed for 35 potential markers using immunoassays. Partial least square discriminant analysis (PLS-DA) was used to derive a biomarker model for cohort classification. The ability of the biomarker model to diagnose esOA was validated by identical wide-spectrum SF analysis of a test cohort of ten patients with esOA. RESULTS: PLS-DA produced a streamlined biomarker model with excellent sensitivity (95%), specificity (98.4%), and reliability (97.4%). The eight-biomarker model produced a fingerprint for esOA comprising type IIA procollagen N-terminal propeptide (PIIANP), tissue inhibitor of metalloproteinase (TIMP)-1, a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), monocyte chemoattractant protein (MCP)-1, interferon-γ-inducible protein-10 (IP-10), and transforming growth factor (TGF)-ß3. Receiver operating characteristic (ROC) analysis demonstrated excellent discriminatory accuracy: area under the curve (AUC) being 0.970 for esOA, 0.957 for knee injury, and 1 for inflammatory arthritis. All ten validation test patients were classified correctly as esOA (accuracy 100%; reliability 100%) by the biomarker model. CONCLUSION: SF analysis coupled with machine learning produced a partially validated biomarker model with cohort-specific fingerprints that accurately and reliably discriminated esOA from knee injury and inflammatory arthritis with almost 100% efficacy. The presented findings and approach represent a new biomarker concept and potential diagnostic tool to stage disease in therapy trials and monitor the efficacy of such interventions.Cite this article: Bone Joint Res 2020;9(9):623-632.

The pattern of cartilage damage in antero-medial osteoarthritis of the knee and its relationship to the anterior cruciate ligament.

Within antero-medial gonarthrosis (AMG) of the knee, there is a spectrum of damage seen in the functionally intact anterior cruciate ligament (ACL). Our aim was to correlate the degree of ACL damage to the geographical extent and degree of cartilage loss on the tibial plateau. Ninety tibial plateaus resected during unicompartmental arthroplasty were photographed and digitally mapped. The ACL damage was graded (0: normal, 1: synovium loss, 2: longitudinal splits), and dimensions of full thickness cartilage loss and damage recorded. The percentage of full thickness loss in patients with a normal ACL was compared to those with a damaged, but functionally intact ligament. All specimens showed similar elliptical loss of cartilage in the antero-medial part of the tibial plateau. A total of 45(50%) patients had a macroscopically normal ACL, 21(23%) had synovial loss, and 24(27%) had longitudinal splits. An increase in the area of cartilage damage was seen with progressive ACL damage (p < 0.001). The area of macroscopically normal cartilage found posteriorly did not change. This study demonstrates that phenotypic distribution of cartilage damage in AMG is highly reproducible with a pattern of increasing cartilage erosion associated with increasing ACL damage.

Hyaluronidase treatment of synovial fluid to improve assay precision for biomarker research using multiplex immunoassay platforms.

Synovial fluid (SF) is a difficult biological matrix to analyse due to its complex non-Newtonian nature. This can result in poor assay repeatability and potentially inefficient use of precious samples. This study assessed the impact of SF treatment by hyaluronidase and/or dilution on intra-assay precision using the Luminex and Meso Scale Discovery (MSD) multiplex platforms. SF was obtained from patients with knee osteoarthritis at the time of joint replacement surgery. Aliquots derived from the same sample were left untreated (neat), 2-fold diluted, 4-fold diluted or treated with 2mg/ml testicular hyaluronidase (with 2-fold dilution). Preparation methods were compared in a polysterene-bead Luminex 10-plex (N=16), magnetic-bead Luminex singleplex (N=7) and MSD 4-plex (N=7). Each method was assessed for coefficient of variation (CV) of replicate measurements, number of bead events (for Luminex assays) and dilution-adjusted analyte concentration. Percentage recovery was calculated for dilutions and HAse treatment. Hyaluronidase treatment significantly increased the number of wells with satisfactory bead events/region (95%) compared to neat (48%, p<0.001) in the polystyrene-bead Luminex assay, but the magnetic-bead Luminex assay achieved ≥50 bead events irrespective of treatment method. Hyaluronidase treatment resulted in lower intra-assay CVs for detectable ligands (group average CV<10%) than neat, 2-fold and 4-fold dilution (CV~25% for all, p<0.05) in both polystyrene- and magnetic-bead Luminex assays. In addition, measured sample concentrations were higher and recovery was poor (elevated) after hyaluronidase treatment. In the MSD 4-plex, within-group comparison of the intra-assay CV or concentration was not conclusively influenced by SF preparation. However, only hyaluronidase treatment resulted in CV<25% for all samples for TNF-α. There was no effect on analyte concentrations or recovery. Hyaluronidase treatment can improve intra-assay precision and assay signal of SF analysis by multiplex immunoassays and should be recommended for SF biomarker research, particularly using the Luminex platform.

Anterior cruciate ligament rupture and osteoarthritis progression.

Anterior Cruciate Ligament (ACL) rupture is a common sporting injury that frequently affects young, athletic patients. Apart from the functional problems of instability, patients with ACL deficient knees also develop osteoarthritis. Although this is frequently cited as an indication for ACL reconstruction, the relationship between ACL rupture, reconstruction and the instigation and progression of articular cartilage degenerative change is controversial.The purpose of this paper is to review the published literature with regards ACL rupture and the multifactorial causes for osteoarthritis progression, and whether or not this is slowed or stopped by ACL reconstruction.There is no evidence in the published literature to support the view that ACL reconstruction prevents osteoarthritis, although it may prevent further meniscal damage. It must be recognised that this conclusion is based on the current literature which has substantial methodological limitations.

Patient decision aids in knee replacement surgery.

Arthroplasty is an effective intervention for symptomatic knee osteoarthritis refractory to conservative therapy. However, recent data highlights regional variations in service provision unrelated to disease severity and a low, but not insignificant, rate of patient dissatisfaction. The variation in knee arthroplasty provision is in part also due to the clinical decision-making of orthopaedic surgeons. The management of osteoarthritis is an example of a preference-sensitive clinical pathway, and possible explanations for poor patient satisfaction include unrealistic expectations and poor perception of potential benefits and risks. In addition to the individual impact, this represents an inefficient use of resources by healthcare providers during a challenging economic period. Improved shared-decision making between patients and clinicians would potentially address these issues. Patient decision aids provide relevant personalized evidence-based information to facilitate the shared decision-making process. Orthopaedic surgeons are receptive to the use of patient decision aids to support shared decision-making, but there are a number of issues to overcome before they are routinely adopted. The number of decision aids and the literature supporting their effectiveness is growing rapidly. NHS Direct has launched online patient decision support for knee osteoarthritis. The use of patient decision aids in clinical practice is gathering pace and may soon become the ethical and legal standard. This article provides a narrative review of patient decision aids in the context of knee replacement surgery from a UK perspective.

Supracondylar femoral fracture after anterior cruciate ligament reconstruction with transfemoral fixation.

Femoral fractures following anterior cruciate ligament (ACL) reconstruction are rare. These injuries often are related to increased stresses at the femoral tunnel. Hamstring tendon autograft is often used for ACL reconstruction, and transfemoral fixation is one of many graft fixation techniques with few reported complications. This article reports an atraumatic transverse supracondylar femoral fracture occurring through the transfemoral fixation tract following hamstring ACL reconstruction in a 38-year-old woman.

Delayed presentation of Subclavian venous thrombosis following undisplaced clavicle fracture.

Medial clavicle fractures are uncommon, accounting for approximately 5 percent of all clavicle fractures. Vascular injuries are uncommon but are recognised as either an immediate complication due to transection of the vessel by the displaced fracture, or as a late complication, secondary to compression from abundant callus formation. We present an unusual case of positional venous insufficiency in the upper limb as an immediate complication of a closed, minimally displaced clavicle fracture, with secondary subclavian venous thrombosis formation eleven days following the injury.