PMC6945372_01
A) axial view of preoperative MRI showing the synovial cyst (SC) hypointense on T1; B) hyperintense on T2-weighted sequence
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MRI of the knee revealed a 48x20x12mm soft tissue mass with clear borders localized at the anterior of proximal tibiofibular joint with poor visualization of the common peroneal nerve (Figure 1).
Intraoperative appearance of the synovial cyst (SC) that infiltrates and compresses the peroneal nerve (PN)
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Intraoperatively, the cystic mass had infiltrated the common fibular nerve with dissociation of its fibers and without any real visualization of pedicle with the proximal tibiofibular joint (Figure 2).
Intraoperative view of the peroneal nerve (PN) after cyst resection
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Resection was minitious to avoid nerve injury (Figure 3).
Recurrence of the synovial cyst four months after the first surgery
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Unfortunately the cyst recidivated four months later with reappearance of a larger mass of about 5cm at the same localization (Figure 4).
Intraoperative view showing total resection of the cyst and the dissociation of the peroneal nerve (PN) fibers
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Surgical resection removed the entire cyst and the pedicle was found and cut, the nerve appears continuous but its fibers are dissociated (Figure 5).
PMC6945372_02
Axial view of preoperative MRI showing the multicompartmental synovial cyst (SC)
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MRI showed an 85x24x10mm multi-compartmental cystic formation at the anterolateral side of fibular head and communicating at its superior pole with the proximal tibiofibular joint by a thin 2mm pedicle (Figure 6).
Intraoperative view showing the close contact between the synovial cyst (SC) and the peroneal nerve (PN)
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Intraoperatively, cystic mass that adhered to and compressed the common peroneal nerve (Figure 7) was totally excised and the pedicle was found and cut.