Radiographic vs. MRI vs. arthroscopic assessment and grading of knee osteoarthritis - are we using appropriate imaging?

PURPOSE: Radiographs and MRI scans are commonly used imaging techniques in the assessment of knee osteoarthritis. However, it currently remains uncertain how good a representation of the actual condition of the knee joint these investigations provide. By comparing them against arthroscopic findings the aim of our study was to conclude how accurate these imaging techniques are at grading knee osteoarthritis. METHODS: This was a retrospective study looking at knee arthroscopies performed at a tertiary centre over a 5 year period. The Outerbridge grade given at arthroscopy was correlated with pre-operative radiograph and MRI scores, so as to assess the reliability of these imaging techniques at predicting the actual severity of knee osteoarthritis seen. RESULTS: Kellgren-Lawrence (KL) grading of radiographs was moderately correlated with Outerbridge grades from arthroscopy for the medial compartment of the knee (Spearman's rho (SR) 0.483, p < 0.001), with a milder correlation in the lateral compartment (SR 0.218, p = 0.003). MRI reporting of knee osteoarthritis was moderately correlated with Outerbridge grades in the medial compartment (SR 0.451, p < 0.001), mildly correlated for both the lateral (SR 0.299, p < 0.001) and patellofemoral joint compartments (SR 0.142, p = 0.054). KL and MRI grading was moderately correlated for the medial compartment (SR 0.475, p < 0.001) and mildly correlated for the lateral compartment (SR 0.277, p < 0.001). CONCLUSION: The ability of radiographs to represent the actual condition of knee osteoarthritis is underestimated. KL grading especially best represents the disease seen in the medial compartment of the knee joint, with a moderate correlation to Outerbridge scores given on arthroscopic assessment. We suggest that whilst MRI is a useful tool in the investigation of knee symptoms, it is often unnecessarily used in patients with OA, when in fact, radiographs alone would be sufficient. EVIDENCE LEVEL: III.

Clinical validation of the Oswestry-Bristol Classification as part of a decision algorithm for trochlear dysplasia surgery.

AIMS: The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective. METHODS: The OBC and the patellotrochlear index were used as part of the Oswestry Patellotrochlear Algorithm (OPTA) to guide the surgical treatment of patients with patellar instability. Patients were assigned to one of four treatment groups: medial patellofemoral ligament reconstruction (MPFLr); MPFLr + tibial tubercle distalization (TTD); trochleoplasty; or trochleoplasty + TTD. A prospective analysis of a longitudinal patellofemoral database was performed. Between 2012 and 2018, 202 patients (233 knees) with a mean age of 24.2 years (SD 8.1), with recurrent patellar instability were treated by two fellowship-trained consultant sports/knee surgeons at The Robert Jones and Agnes Hunt Orthopaedic Hospital. Clinical efficacy of each treatment group was assessed by Kujala, International Knee Documentation Committee (IKDC), and EuroQol five-dimension questionnaire (EQ-5D) scores at baseline, and up to 60 months postoperatively. Their safety was assessed by complication rate and requirement for further surgery. The pattern of clinical outcome over time was analyzed using mixed regression modelling. RESULTS: In all, 135 knees (mean age 24.9 years (SD 9.4)) were treated using a MPFLr. Ten knees (7.4%) required additional surgery. A total of 50 knees (mean age 24.4 years (SD 6.3)) were treated using MPFLr + TTD. Ten (20%) required additional surgery. A total of 20 knees (mean age 19.5 years (SD 3.0)) were treated using trochleoplasty + TTD. Three patients (15%) required additional surgery. In each treatment group, there was a significant improvement in Kujala, IKDC, and EQ-5D at one year postoperatively (p < 0.001) with a recognized level of overall complication rate. CONCLUSION: The OBC is a valid assessment tool to grade patients with trochlear dysplasia and, when used as part of the OPTA, helps to determine treatments that are safe and effective. This fulfils the requirements for its application in mainstream clinical practice. Cite this article: Bone Joint J 2021;103-B(10):1586-1594.

Pain and outcomes of carpal tunnel release under local anaesthetic with or without a tourniquet: a randomized controlled trial.

We conducted a prospective randomized controlled trial to investigate carpal tunnel decompression under local anaesthesia. Carpal tunnel decompression was performed in 37 wrists using local anaesthesia and an arm tourniquet and 36 without tourniquet but with a local anaesthetic mixture containing adrenaline. Patients who underwent carpal tunnel decompression using a tourniquet experienced a significantly greater degree of pain when compared with those who did not have a tourniquet. Pain and hand function improved to a similar degree in both groups. We conclude that carpal tunnel decompression performed with a tourniquet causes patients unnecessary pain with no additional benefit as compared with the wide-awake carpal tunnel decompression without use of a tourniquet. LEVEL OF EVIDENCE: I.