Low incidence of pulmonary metastases in vulvar cancer patients: limited value of routine chest imaging based on a cohort study.

OBJECTIVE: To evaluate the incidence of pulmonary metastases in the preoperative work-up of patients with primary vulvar squamous cell carcinoma (SCC). DESIGN: Retrospective cohort study. SETTING: Tertiary referral centre. POPULATION: Patients treated for primary vulvar SCC from 2000 to 2018. METHODS: The pre-operative chest imaging of 452 consecutively treated patients was documented with a minimal follow-up period of 2 years. MEAN OUTCOME MEASURES: Incidence of pulmonary metastases, frequency of chest imaging and subsequent coincidental findings. RESULTS: In total, 80.8% of patients underwent pre-operative chest imaging. Seven patients (1.9%), with a median tumour size of 80 mm, presented with pulmonary metastases. None of the patients with early stage disease and tumour size <40 mm who underwent radical local excision (RLE) with sentinel node (SN)-procedure, was diagnosed with pulmonary metastasis. Chest imaging was performed by radiography (58.9%) and computerised tomography (CT) (41.1%). Coincidental findings were reported in 40.7% of patients who underwent CT, compared with 15.8% of patients undergoing radiography, resulting in additional diagnostics in 14.7 and 19.7% and being of limited consequence for outcome in 2.9 and 3.3%, respectively. CONCLUSIONS: The incidence of pulmonary metastases in patients with primary vulvar SCC is extremely low, and none in patients with early stage disease undergoing the SN procedure. Chest imaging was performed in the majority of patients and was associated with frequent coincidental findings leading to clinically irrelevant diagnostic procedures. Therefore, we recommend omitting chest imaging in patients with early stage disease and tumours <40 mm, considering chest CT only in patients with large tumours and/or advanced stage disease. TWEETABLE ABSTRACT: The incidence of pulmonary metastases is 1.9%, none in early stage disease planned for SN. Omitting chest imaging in this group is advised.

3D geometry analysis of the medial meniscus--a statistical shape modeling approach.

The geometry-dependent functioning of the meniscus indicates that detailed knowledge on 3D meniscus geometry and its inter-subject variation is essential to design well functioning anatomically shaped meniscus replacements. Therefore, the aim of this study was to quantify 3D meniscus geometry and to determine whether variation in medial meniscus geometry is size- or shape-driven. Also we performed a cluster analysis to identify distinct morphological groups of medial menisci and assessed whether meniscal geometry is gender-dependent. A statistical shape model was created, containing the meniscus geometries of 35 subjects (20 females, 15 males) that were obtained from MR images. A principal component analysis was performed to determine the most important modes of geometry variation and the characteristic changes per principal component were evaluated. Each meniscus from the original dataset was then reconstructed as a linear combination of principal components. This allowed the comparison of male and female menisci, and a cluster analysis to determine distinct morphological meniscus groups. Of the variation in medial meniscus geometry, 53.8% was found to be due to primarily size-related differences and 29.6% due to shape differences. Shape changes were most prominent in the cross-sectional plane, rather than in the transverse plane. Significant differences between male and female menisci were only found for principal component 1, which predominantly reflected size differences. The cluster analysis resulted in four clusters, yet these clusters represented two statistically different meniscal shapes, as differences between cluster 1, 2 and 4 were only present for principal component 1. This study illustrates that differences in meniscal geometry cannot be explained by scaling only, but that different meniscal shapes can be distinguished. Functional analysis, e.g. through finite element modeling, is required to assess whether these distinct shapes actually influence the biomechanical performance of the meniscus.

Physical examination and in vivo kinematics in two posterior cruciate ligament retaining total knee arthroplasty designs.

The aim of this study was to investigate anteroposterior instability in the CKS and the PFC total knee arthroplasty (TKA) designs. Physical examinations, including VAS, IKS and WOMAC were performed in combination with a detailed fluoroscopic measurement technique for three-dimensional kinematic assessment of TKA design function. Anteroposterior instability rated with the IKS was not significantly different (p=0.34), but patients with a CKS design showed more limitations according to the WOMAC joint stiffness total score, and for items regarding higher flexion activities in the WOMAC score for knee disability. Kinematic analyses showed that the CKS design tended to have more anterior sliding of the femur on the tibia during mid- and deep flexion activities. The sliding distance was larger at the medial than at the lateral side. This phenomenon has also been described for posterior cruciate ligament deficient knees. Furthermore, the CKS design showed a significantly lower range of tibial rotation (p<0.05) from maximum extension to maximum flexion during deep knee bend activities. Kinematic differences can be ascribed to posterior cruciate ligament deficiency/laxity or differences in TKA designs.