Several studies have evaluated the risk of peroneal nerve (PN) injuries in all-inside lateral meniscal repair using standard knee magnetic resonance imaging (MRI) with the 30 degrees flexed knee position which is different from the knee position during actual arthroscopic lateral meniscal repair. The point of concern is “Can the risk of PN injury using standard knee MRIs be accurately determined”.

To evaluate and compare the risk of PN injury in all-inside lateral meniscal repair in relation to both borders of the popliteus tendon (PT) using MRIs of the two knee positions in the same patients.

Using axial MRI studies with standard knee MRIs and figure-of-4 with joint fluid dilatation actual arthroscopic lateral meniscal repair position MRIs, direct lines were drawn simulating a straight all-inside meniscal repair device from the anteromedial and anterolateral portals to the medial and lateral borders of the PT. The distance from the tip of each line to the PN was measured. If a line touched or passed the PN, a potential risk of iatrogenic injury was noted and a new line was drawn from the same portal to the border of the PN. The danger area was measured from the first line to the new direct line along the joint capsule.

In 28 adult patients, the closest distances from each line to the PN in standard knee MRI images were significantly shorter than arthroscopic position MRI images (all p-values < 0.05). All danger areas assessed in the actual arthroscopic position MRIs were included within the danger areas as assessed by the standard knee MRIs.

We found that the standard knee MRIs can be used to determine the risk of peroneal nerve injury in arthroscopic lateral meniscal repair, although the risks are slightly overestimated.

To study in resolution of triggering 12 months after injection with either a soluble methylprednisolone acetate or dexamethasone for idiopathic trigger finger.

Twenty-eight patients were enrolled in a prospective randomized controlled trial comparing methylprednisolone acetate and dexamethasone injection for idiopathic trigger finger. Twenty-seven patients completed the 6-week follow-up (11 methylprednisolone acetate arm, 16 dexamethasone arm) and thirteen patients completed the 3-month follow-up (4 methylprednisolone acetate arm, 9 dexamethasone arm). Outcome measures included resolution of triggering, recurrence rate of trigger finger, satisfaction on a visual analog scale, tender, snapping, locking, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and tip to palm distance (mm.) at 2, 6, 12 and 24 weeks follow-up. Eight patients were repeated a second injection (3 methylprednisolone acetate arm, 5 dexamethasone arm) at 6-week follow-up. To preserve autonomy, patients were permitted operative treatment any time. The analysis was according to intention to treat principles.

Six weeks after injection. Absence of triggering was documented in 6 of 11 patients in the methylprednisolone cohort and in 6 of 16 patients in the dexamethasone cohort. The rate 3-month after injection were 2 of 4 patients in the methylprednisolone cohort and in 8 of 9 patients in the dexamethasone cohort. There were no significant difference between recurrence rate of trigger finger, satisfaction on a visual analog scale, tender, snapping, locking, the Disabilities of the Arm, Shoulder and Hand (DASH) scores and tip to palm distance (mm.) at 2, 6, 12 and 24 weeks follow-up.

Although there were no differences 3months after injection, our data suggest that in the dexamethasone cohort was better in resolution of triggering than the methylprednisolone cohort at 12-week follow-up.