This study looks for correlation between pre-operative MRI and intra-operative surgical findings regarding the site of medial patellofemoral ligament (MPFL) rupture in first time patella dislocaters with the aim of confirming the reliability of this modality of imaging. A retrospective analysis of all patients who were referred for MRI following patella dislocation was performed. The surgical and MRI findings of those who subsequently underwent MPFL repair were compared to look for any correlation.Aim
Methods
The medial patellofemoral ligament is commonly torn in first patella dislocation and according to the literature occurs most frequently at the femoral insertion. As research has demonstrated the MPFL to be a primary soft tissue stabilizer of the patella there has been increased interest in acute repair of the ligament with the aim of reducing the risk of recurrent dislocation. MRI is generally used pre op to identify the site of rupture allowing planning of the surgical repair, however there is currently no published data regarding the correlation between surgical and MRI findings to confirm the reliability of this modality of imaging. A retrospective analysis of all patients who were referred for MRI following patella dislocation was performed. The surgical and MRI findings of those who subsequently underwent MPFL repair were compared to look for any correlation. 41 patients were first time patella dislocators and 38 had MPFL rupture diagnosed on MRI. Of these 19 progressed to surgical intervention and 17 had adequate data available from the notes and to permit comparison. All of the MPFLs ruptured at the patella insertion. In 76.5% (13/17) of patients the site of MPFL rupture was correctly identified on MRI scan. Of those that were discordant 3/4 had the site of rupture identified as the femoral insertion on MRI and on 1/4 the MRI suggested rupture at both the femoral and patella insertions. MPFL rupture is common in first time dislocations occurring in 93%% of this cohort. There was a clear predominance patella insertion rupture in our study which contrasts with the majority of the published literature. By correlating surgical and radiological findings we can conclude that while MRI can accurately diagnose MPFL rupture at the patella insertion but it is less accurate in identifying rupture at the femoral insertion.
Intraosseous schwannoma is a rare benign neoplasm, which most commonly arises in the head and neck region particularly the mandible, due to the long intraosseous path of sensory nerves in the mandible. We present a 27-year-old lady with an unusual presentation of an intraosseous schwannoma of the first metatarsal. There is only one report published previously of an intraossous schwannoma of the lesser metatarsal bone of the foot. A 27-year-old woman presented with painful left forefoot following a trip while walking. Plain radiographs demonstrated a pathological fracture through a lytic lesion of the first metatarsal of the left foot. MRI scan using axial T1-weighted spin echo and axial and sagittal T2-weighted gradient echo showed an amorphous mass occupying the medulla of the bone but with a breach of the plantar aspect of cortex with apparent localised destruction. Ultrasound-guided biopsy was performed. Haematoxylin and Eosin stained specimen sections showed a proliferation of spindle cells of alternating hypercellularity and hypocellularity. This case was managed by curettage and grafting with autograft and synthetic bone substitute. At two-year follow-up, the radiographs showed complete graft incorporation and a healed cyst. The patient was clinically asymptomatic with return of full functions. There were no clinico-radiological findings to suggest any recurrence. Due to rarity and non-specific clinico-radiological features, this case illustrates the necessity of a multi-disciplinary approach with an accurate histological diagnosis in combination with radiological and clinical appearances.
