Does component placement affect short-term clinical outcome in robotic-arm assisted unicompartmental knee arthroplasty?

AIMS: The purpose of this multicentre observational study was to investigate the association between intraoperative component positioning and soft-tissue balancing on short-term clinical outcomes in patients undergoing robotic-arm assisted unicompartmental knee arthroplasty (UKA). PATIENTS AND METHODS: Between 2013 and 2016, 363 patients (395 knees) underwent robotic-arm assisted UKAs at two centres. Pre- and postoperatively, patients were administered Knee Injury and Osteoarthritis Score (KOOS) and Forgotten Joint Score-12 (FJS-12). Results were stratified as "good" and "bad" if KOOS/FJS-12 were more than or equal to 80. Intraoperative, post-implantation robotic data relative to CT-based components placement were collected and classified. Postoperative complications were recorded. RESULTS: Following exclusions and losses to follow-up, 334 medial robotic-arm assisted UKAs were assessed at a mean follow-up of 30.0 months (8.0 to 54.9). None of the measured parameters were associated with overall KOOS outcome. Correlations were described between specific KOOS subscales and intraoperative, post-implantation robotic data, and between FJS-12 and femoral component sagittal alignment. Three UKAs were revised, resulting in 99.0% survival at two years (95% confidence interval (CI) 97.9 to 100.0). CONCLUSION: Although little correlation was found between intraoperative robotic data and overall clinical outcome, surgeons should consider information regarding 3D component placement and soft-tissue balancing to improve patient satisfaction. Reproducible and precise placement of components has been confirmed as essential for satisfactory clinical outcome. Cite this article: Bone Joint J 2019;101-B:435-442.

Synovial colony-stimulating factor-1 mRNA expression in diffuse pigmented villonodular synovitis.

OBJECTIVES: To delineate the molecular mechanisms underlying the process of the diffuse-type giant cell tumours, also called pigmented villonodular synovitis, a rare, aggressive condition of the synovium, the knee synovial tissue expression of colony-stimulating factor-1 gene, as detected by real-time polymerase chain reaction, was compared between patients affected with pigmented villonodular knee synovitis and knee meniscal tears, or persistent gonoarthitis. METHODS: Multiple synovial biopsies of the knee were performed by arthroscopy in five consecutive patients affected by diffuse pigmented villonodular knee synovitis and in 12 patients affected by knee meniscal tears (n. 6) or persistent active gonarthritis (n. 6), recruited from the patients attending the Rheumatology Day Surgery Outpatient Clinic of the University of Padova Hospital. The ethics committee approved the study protocol and the participants signed consent statements after being informed about the content of the study. The diagnosis was made on the basis of a histological examination. The colony-stimulating factor-1 gene expression was assessed by reverse transcription followed by real-time polymerase chain reaction. RESULTS: The detection by RT-PCR of synovial colony-stimulating factor-1 mRNA showed a wide spectrum of expression in the three groups of distinct knee joint disease affected patients, with significantly higher level of colony-stimulating factor-1 mRNA expression in synovial tissue of pigmented villonodular synovitis, in comparison to that of knee meniscal injuries and persistent gonoarthritis patients. CONCLUSIONS: Our findings point out to an important role of colony-stimulating factor-1 in pigmented villonodular knee synovitis disease process and support the idea that colony-stimulating factor-1/colony-stimulating factor-1 receptor interaction may represent a potential therapeutic target of this disease.

Molecular pathways involved in synovial cell inflammation and tumoral proliferation in diffuse pigmented villonodular synovitis.

Diffuse-type tenosynovial giant cell tumors, also known as pigmented villonodular synovitis, are unique mesenchymal lesions that arise from the synovial tissue of the joints. They are predominantly intraarticular, aggressive, infiltrative processes, characterized by both inflammatory or neoplastic properties and local destructive progression. The pattern of synovial gene and protein expressions in pigmented villonodular synovitis, similar to those in activated macrophages in rheumatoid arthritis, and the phenotype of multinucleated giant cells, characteristic of osteoclasts, suggest that there is a common autocrine mechanism in osteoclast differentiation in both diseases and indicate the potential utility of tumor necrosis factor (TNF)-alpha blockade. High synovial colony stimulating factor 1 (CSF1) messenger RNA (m RNA) expression in pigmented villonodular synovitis, unrelated to a chromosomal translocation involving CSF1 locus, may indicate that there is a synergic paracrine loop mediated by TNF-alpha and CSF1, as shown in both inflammatory and neoplastic conditions. The effects of a new therapeutic approach consisting in intraarticular TNF-alpha blockade were studied in four pigmented villonodular synovitis knees. Knee injections produced a rapid reduction in clinical and sonographic indexes and immunohistological alterations, confirmed by arthroscopic synovectomy. A delayed relapse in one of the four knees and unaltered synovial CSF1 expression were other important findings. In the light of these observations, CSF1/CSF1R interaction probably represents a more sensible therapeutic target than TNF-alpha blockade in the diffuse form of pigmented villonodular synovitis.

[Intra-articular treatment with the TNF-alpha antagonist, etanercept, in severe diffuse pigmented villonodular synovitis of the knee]. / Trattamento intra-articolare con l'antagonista del TNFalpha etanercept nella sinovite villo-nodulare pigmentosa diffusa del ginocchio.

Pigmented villonodular synovitis (PVNS) is a rare pre-malignant disease that require aggressive treatment as surgical synovectomy, eventually followed by radiosynovectomy. Nevertheless, the disease often reoccurs after these treatments. To determine the safety and efficacy of intra-articular (IA) TNFalpha blockade with etanercept (ETN), before extended arthroscopic synovectomy, in severe PVNS of the knee, two patients, (a 26-year-old man with B27+ undifferentiated spondylarthropathy and a 32-year-old femal with seronegative oligoarthritis), affected by diffuse knee PVNS (diagnosis made by histological examination), resistant to IA corticosteroid injections and to repeated arthroscopic synovectomy, were submitted, after protocol approval by human research committee and patient's written informed consent to intra-articular etanercept (IA-ETN) treatment with a different dosage schedule: 12.5 mg weekly IA-ETN injection for 4 weeks, followed by extended arthroscopic synovectomy and of 25 mg IA-ETN injection for 4 weeks, respectively. Previous DMARDs treatment was continued in stable appropriate doses. Any adverse events were recorded throughout the study. The following parameters were considered as clinical endpoints: 1) Knee Joint Index (KJI: range 0-14); 2) Thompson index (THI: range 0-9) At the study entry and at the end of follow-up, high frequency ultrasound grey scale synovial thickening (US-ST) was also assessed. No adverse events were observed due to IA-ETN and to arthroscopic synovectomy. Marked improvement of knee disease activity over time and sustained functional recover was obtained. US-ST evaluation before treatment initiation and at the end of follow-up confirmed the regression of knee joint synovial proliferation.

Rheumatoid and psoriatic knee synovitis: clinical, grey scale, and power Doppler ultrasound assessment of the response to etanercept.

OBJECTIVE: To determine the effect of tumour necrosis factor alpha (TNFalpha) blockade with etanercept in refractory knee joint synovitis (KJS) in rheumatoid and psoriatic arthritis, by local and systemic disease activity assessment and combined grey scale and power Doppler ultrasonographic monitoring. METHODS: 27 knees affected by rheumatoid KJS (n = 12) and psoriatic KJS (n = 8) were assessed before receiving treatment and at 3 and 12 months' follow up. Time dependent clinical changes in disease activity were monitored by C reactive protein, erythrocyte sedimentation rate (ESR), global health status (GHS), and Ritchie (RAI) and knee joint articular (KJAI) indices; synovial changes were monitored by ultrasonographic and power Doppler indices for grey scale synovial thickening and for distinct intrasynovial vessel power Doppler flow configurations (fluid/synovium interface (F/SI-PD) and pannus/cartilage interface (P/CI-PD)). Interobserver and intraobserver variability of grey scale and power Doppler ultrasonographic was evaluated. Response to treatment was assessed by analysis of variance for repeated measures on clinical and ultrasonographic variables. RESULTS: Rapid (3 months) reduction in F/SI-PD flow (p<0.001), parallel to reductions of C reactive protein (p<0.05), ESR (p<0.001), KJAI (p<0.002), RAI, and GHS (p<0.001), was sustained at 12 months when it was accompanied by reduction in both synovial thickening and P/CI-PD flow (p<0.001). No differences (ANOVA) were noted at baseline or at 12 months in clinical and ultrasonographic variables between either the rheumatoid or the psoriatic KJS groups. CONCLUSION: Grey scale and power Doppler ultrasonography are reliable measures of long term change in rheumatoid and psoriatic KJS disease activity in response to anti-TNFalpha treatment with etanercept.

Vascular changes in psoriatic knee joint synovitis.

OBJECTIVE: To evaluate the diagnostic utility of standard arthroscopy supported by a computerized image analysis system; and to examine and quantify the macroscopic appearance of blood vessels in selected anatomical areas, comparing 2 groups of patients with PsA and RA with refractory knee joint synovitis (KJS) for vascular marking (VM) features and VM scores, as well as for the relationship between respective VM scores and local and systemic KJS disease activity indices. METHODS: Standard arthroscopy was carried out on 39 knees (20 PsA, 19 RA). Videorecordings of the examination were reanalyzed using a computer image analysis system and software. The appearance of vascular markings was assessed and separately scored for the areas of surface synovium (capsular, CVM), villous proliferation (villous, VVM), and synovium adherent to cartilage (pannus, PVM). Indices of systemic (erythrocyte sedimentation rate, ESR) and local KJS disease activity (clinical index) were obtained before arthroscopy. The morphology and scores of the distinct VM were compared between PsA and RA groups, as was the relationship between respective VM scores and ESR and KJS clinical indices. RESULTS: Distinctive VM features were observed for PsA and RA KJS in each separate synovial architecture examined. VVM and CVM scores were significantly correlated with each other in PsA knees, and were significantly higher in PsA compared with RA. In both diseases, VVM and CVM scores were not related to KJS duration or activity or to ESR values, but in RA they were directly correlated with KJS activity. Moreover, the VVM capillary feature "meandering with tight convolutions," considered unique to psoriatic skin, was observed in the synovium of 13 PsA (65%) and one RA KJS (5.5%). The mean KJS duration of the PsA group with typical VVM was significantly lower than the group without VVM (2.6 +/- 1.77 vs 9.4 +/- 8.28 yrs). CONCLUSION: Our macroscopic observations of distinct changes in VM expression in selected anatomical areas of PsA and RA KJS suggest possible pathogenetic differences between the 2 diseases. The typical morphology and higher intensity of villous vascularization, in both early and chronic disease, and the different clinical relevance of VVM scores in PsA compared with RA KJS support the potential use of vascular markings as reliable outcome measures of the PsA process in KJS.

[Acute knee block. Assessment with magnetic resonance, correlated with arthroscopy]. / Blocco articolare acuto del ginocchio. Studio con Risonanza Magnetica, correlato con artroscopia.

Posttraumatic acute articular blocks of the knee may be caused by "mechanical" factors, such as the interposition of some osteochondral, meniscal or ligamentous fragments between condyles and tibial plateau or by non-mechanical ("functional") factors, such as the pain associated with capsular-ligamentous structure injuries or with intraosseous bruises involving the synovia. From January, 1994, to January, 1996, we examined 751 patients for posttraumatic knee injuries. The patients were submitted to MRI with a dedicated unit and we selected 86 of them who had an acute articular block as the major symptom. The block had a mechanical cause in 36 patients of the selected group (41.8%), as confirmed at arthroscopy, while the other 50 patients (58.2%) had a functional block. Fifteen of the latter patients had only intraosseous bruising, with no ligament or meniscus damage, while the other 35 had isolated or variously associated menisco-ligamentous injuries, as confirmed at arthroscopy. All the patients also had some intraosseous bruises which were clearly depicted at MRI. This study demonstrates that MRI is an extremely valuable tool in assessing the cause of articular blocks, allowing a prompt appropriate choice to be made between therapeutic arthroscopy and weight-free limb immobilization.