The importance of early diagnosis in spontaneous osteonecrosis of the knee - A case series with six year follow-up

Background: Spontaneous osteonecrosis of the knee has an unknown aetiology. Management options include conservative, surgical and pharmacological interventions. The aim of this study was to report the experience of the authors in conservative management of SONIC using non-operative measures by analysing the functional outcome and need for surgical intervention. Materials and methods: All patients treated for SONIC between 1st August 2001 and 1st April 2014 were retrospectively reviewed. Treatment consisted of touch-down weight bearing for around six weeks. MR imaging was evaluated for size of lesion, the condyles involved and the time taken for resolution. Tegner Activity Scale, VAS pain, Lysholm, WOMAC and HOC scores were recorded at presentation and final follow-up (mean six years, range six months to 13 years). Results: Forty cases were included; the mean age of the group was 55.3 years and 67.5% were male. The medial femoral condyle was the most commonly affected (52.5%). A statistically significant improvement was reported in all functional outcome measures (p < 0.001). Only one patient required arthroscopic surgical intervention and no patients required arthroplasty during the follow-up period. Conclusion: Early stage spontaneous osteonecrosis of the knee can be managed successfully without surgery if diagnosed early. Thus early investigation of acute knee pain with MRI scanning is recommended. (C) 2016 Elsevier B.V. All rights reserved.