Long-Term Outcome of Hip Arthroplasty in the Setting of Synovial Chondromatosis

The 2020 World Health Organization classification of bone tumors: what radiologists should know

Improved understanding of tumor biology through molecular alteration and genetic advances has resulted in a number of major changes in the 2020 World Health Organization's (WHO) classification of bone tumors. These changes include the reclassification of the existing tumors and the introduction of several new entities. A new chapter on undifferentiated small round cell sarcomas of bone and soft tissue was added to classify Ewing sarcoma and the family of Ewing-like sarcomas, which share similar histologies but different molecular and clinical behaviors. Knowledge of the current classification of bone tumors is essential to ensure the appropriate recognition of the inherent biological potential of individual osseous lesions for optimal treatment, follow-up, and overall outcome. This article reviews the major changes to the 2020 WHO's classification of primary bone tumors and the pertinent imaging of selected tumors to highlight these changes.

Primäre synoviale Chondromatose

Hintergrund

Die primäre synoviale Chondromatose (SC) ist eine seltene Erkrankung der Synovialmembran unklarer Ätiologie. Der aktuelle Wissensstand zu dieser Erkrankung soll in einer kurzen Übersicht dargestellt werden.

Methoden

Übersichtsarbeiten und rezente Fallberichte zur SC wurden systematisch ausgewertet und mit Daten eigener Fälle in Kontext gesetzt.

Ergebnisse

Auf Grund neuer genomischer Daten wird die SC als benigne Neoplasie eingestuft. In 60 % der Fälle liegen Mutationen im Fibronektin-1-Gen (FN1) und/oder im Gen für den Activin-A-Typ-II-Rezeptor (ACVR2A) vor. Diagnoseweisend ist die Magnetresonanztomographie (MRT) und die meist arthroskopische Biopsie der Synovia. An einem Fallbeispiel soll gezeigt werden, dass die Knorpelaggregate der SC radiologisch nicht immer schattengebend sein müssen. Differenzialdiagnostisch kommen Monarthritiden anderer Ursachen, andere Gelenk- und Muskelerkrankungen mit Mineralisierung sowie weitere von der Synovialmembran ausgehende Erkrankungen in Betracht. Die Entartungsrate liegt bei 2–4 %. Therapeutisch hat sich in den letzten Jahren das arthroskopische Vorgehen durchgesetzt, das an die Ausdehnung der Erkrankung adaptiert wird.

Schlussfolgerung

Genomische Untersuchungen sowie Fallserien und Fallberichte aus jüngerer Zeit werfen ein neues Licht auf die SC. Therapeutisch wird in jüngeren Arbeiten überwiegend arthroskopisch vorgegangen.

Giant synovial chondromatosis of hip

Synovial chondromatosis is a rare, benign condition occurring due to metaplasia of synovium. A 65-year-old woman presented with pain in her right hip for 6 years. On examination, a swelling was palpable at the base of scarpa's triangle and her right hip movements were restricted. Imaging modalities showed ossified nodules in the antero-inferior aspect of the hip joint, joint effusion and arthritic changes. We diagnosed the patient to have synovial chondromatosis with secondary arthritis of the hip joint. We performed a total hip arthroplasty with simultaneous synovectomy and extraction of the osteochondral loose bodies, 5 of which were about 2×2 cm in size. We found that excessive acetabular reaming was required due to craters, the osteochondral masses formed on the acetabular surface. Histopathological analysis confirmed the diagnosis. The patient had an excellent functional outcome and no recurrence 5 years following the surgery.

Clinical comparison of tenosynovial giant cell tumors, synovial chondromatosis, and synovial sarcoma: analysis and report of 53 cases

Background

Tenosynovial giant cell tumors (TGCTs), synovial chondromatosis (SC), and synovial sarcoma (SS) exhibit similarities in clinical features and histochemical characteristics, and differential diagnosis remains challenging in clinical practice.

Methods

Data were collected from the pathology database of Shanghai Ninth People's Hospital regarding patients who underwent surgery from 2010 to 2019 with histologically confirmed TGCTs, SC, and SS. Demographic and clinicopathological data of these patients were reviewed. Immunohistochemistry staining of 14 different markers was performed. Correlation analyses of the prognoses were evaluated.

Results

A total of 26 patients with TGCTs (8 diffuse TGCTs and 18 localized TGCTs), 16 with SC, and 11 with SS were identified. Pain was the main symptom of patients with both TGCTs and SC, while a palpable mass was the most common symptom for patients with SS. In addition to clinical features, we identified vital risk factors for disease recurrence. The mean follow-up periods were 51, 39, and 14 months for TGCTs, SC, and SS, respectively. Younger patients with diffuse TGCTs or patients with a higher neutrophil/lymphocyte ratio (NLR) displayed a significantly higher frequency of recurrence. We also plotted receiver operating characteristic (ROC) curve analysis for age and NLR. The area under the ROC curve (AUC) was calculated and demonstrated the ability to distinguish recurrent from nonrecurrent cases. In addition, higher CD163 expression was linked to recurrent diffuse TGCT cases.

Conclusions

These data indicated possible characteristics of different aspects of TGCTs, SC, and SS. Further clarification and understanding of these factors will help with differential clinical diagnosis and recurrent risk assessment.

Clinical outcomes and causes of arthroscopic hip revision surgery

Hip arthroscopic surgery has become a common technique during the past decade, leading to an increased number of arthroscopic hip revision surgeries. This study aimed to evaluate the clinical outcomes in a series of revision hip arthroscopies to analyse the causes of reoperation in the short to medium-term follow-up. We retrospectively analysed 22 patients who underwent arthroscopic hip revision surgery in our institute. All patients accepted a detailed physical examination and obtained radiographs to measure the centre edge angle, the alpha angle and the offset. Three-dimensional computed tomography was used to evaluate the deformities. The modified Harris Hip Score, visual analogue scale and patient self-reported satisfaction were collected and analysed preoperatively and postoperatively. Our results demonstrated that the modified Harris Hip Score improved from 52.8 to 81.6, and the visual analogue scale decreased from 5.0 to 1.1. Patient self-reported satisfaction was 8.5. In conclusion, patients who underwent arthroscopic hip revision surgery exhibited significant improvement in patient-centred outcomes in the short- to medium-term follow-up, and the outcomes indicated the effectiveness of revision surgery. Residual femoroacetabular impingement and extra-articular impingement are common reasons for arthroscopic hip revision surgery. Misdiagnosis of osteoid osteoma and relapse of synovial chondromatosis are also important reasons for revision.