Primary synovial chondromatosis of the talonavicular joint: A case report

Synovial chondromatosis of the foot: Two case reports and literature review

BACKGROUND

Primary synovial chondromatosis (PSC) is a rare arthropathy of the synovial joints characterized by the formation of cartilaginous nodules, which may detach and become loose bodies within the joint and may undergo secondary proliferation. PSC of the foot and ankle is exceedingly rare, with only a few cases reported in the literature. The diagnosis may be difficult and delayed until operative treatment, when it is confirmed by histological assessment. PSC may degenerate into chondrosarcoma. Operative treatment is the gold standard aiming to minimize pain, improve function, prevent or limit progression of arthritis. Surgical treatment consists in debridement by arthrotomic or arthroscopic management, but there is no consensus in the literature about timing of surgery and surgical technique. Thus, the aim of this study is to report the outcomes of the surgical treatment of two cases, together with a literature review.

CASE SUMMARY

We report two cases of patients affected by PSC of the foot in stage III, according to the Milgram classification: the former PSC localized in the ankle that underwent open surgery consisted of loose bodies removal; the latter in the subtalar joint, and the choice of treatment was the arthrotomy and debridement from loose bodies, in addition to the subtalar arthrodesis. Both patients returned to complete daily and working life after surgery.

CONCLUSION

Synovial chondromatosis is a rare benign pathology, even rarer in the ankle joint and especially in the foot. Surgery should be minimal in patients with ankle PSC, choosing the correct timing, waiting if possible until stage III. More aggressive and early surgery should be performed in patients with PSC of the foot, particularly the subtalar joint, due to the high risk of arthritic evolution.

[Foot and ankle tumours : Part II: Malignant bone tumours and soft tissue tumours of the foot with differential diagnostic hints]

CLINICAL ISSUE

Both benign and malignant tumours are encountered in the foot and ankle. Due to their rarity, however, diagnosis is often uncertain. Usual criteria such as tumour size, invasiveness or pain fail to differentiate benign from malignant neoplasias.

STANDARD RADIOLOGICAL METHODS

Plain radiography and-due to the complex foot anatomy-CT are important in the diagnostic evaluation of primary bone tumours. In the case of soft tissue tumours, ultrasonography is used to identify ganglion cysts. Tumour evaluation and staging are then performed using MRI. Nuclear imaging comes into play when multifocal, metastatic or systemic spread of the disease is suspected or if a biopsy procedure is planned.

METHODICAL INNOVATIONS

For the role of dual-energy CT, please refer to part I. Whether dual-energy CT is suitable to assess bone marrow oedema patterns is still debated.

SPECIAL FEATURES OF FOOT AND ANKLE TUMOURS

Primary bone tumours generally present in the ankle or the hindfoot. Malignant bone tumours, e. g. chondrosarcoma, are primarily found in the latter. On the other hand, soft tissue tumours generally present in the mid- and forefoot regions.

ACHIEVEMENTS

While the radiologic diagnostic evaluation of pedal bone tumours is quite reliable, caution is urgently needed in the case of soft tissue tumours because there are many confusing differential diagnoses.

PRACTICAL RECOMMENDATIONS

Proper X‑ray examination of the foot (at least in two plains) or with special views according to bony pathology is needed. All soft tissue masses that are not cysts should be evaluated further. MRI remains the diagnostic modality of choice but never stands alone! Caution: Size and well-defined margins of pedal soft tissue tumours are not considered criteria regarding whether a tumour is malignant or not.

Synovial Chondromatosis in the First Metatarsophalangeal Joint: A Case Report of this Uncommon Condition and Review of Current Literature

Introduction

Synovial osteochondromatosis is a rare condition characterized by the formation of multiple cartilaginous nodules, which involves metaplastic changes of the synovium and is commonly found in larger joints. Occurrence in foot and ankle is uncommon, even less in metatarsophalangeal joints.

Case Report

A 54-year-old woman with primary synovial osteochondromatosis in the first metatarsophalangeal joint was treated by complete excision plus synovectomy. After 8years of follow-up, the patient remains symptom free with no recurrence observed. A summary of the case and review of all published cases found in the current literature around this location is discussed.

Conclusion

Though rare, synovial chondromatosis should be considered as a differential diagnosis in a refractory synovitis and tumor mass in the metatarsophalangeal joint of the hallux.