The AMADEUS score is not a sufficient predictor for functional outcome after high tibial osteotomy

PURPOSE

The Area Measurement And Depth Underlying Structures (AMADEUS) classification system has been proposed as a valuable tool for magnetic resonance (MR)-based grading of preoperatively encountered chondral defects of the knee joint. However, the potential relationship of this novel score with clinical data was yet to determine. It was the primary intention of this study to assess the correlative relationship of the AMADEUS with patient reported outcome scores in patients undergoing medial open-wedge high tibial valgus osteotomy (HTO). Furthermore, the arthroscopic ICRS (International Cartilage Repair Society) grade evaluation was tested for correlation with the AMADEUS classification system.

METHODS

This retrospective, monocentric study found a total of 70 individuals that were indicated for HTO due to degenerative chondral defects of the medial compartment between 2008 and 2019. A preoperative MR image as well as a pre-osteotomy diagnostic arthroscopy for ICRS grade evaluation was mandatory for all patients. The Knee Osteoarthritis Outcome Score (KOOS) including its five subscale scores (KOOS-ADL, KOOS-QOL, KOOS-Sports, KOOS-Pain, KOOS-Symptoms) was obtained preoperatively and at a mean follow-up of 41.2 ± 26.3 months. Preoperative chondral defects were evaluated using the AMADEUS classification system and the final AMADEUS scores were correlated with the pre- and postoperative KOOS subscale sores. Furthermore, arthroscopic ICRS defect severity was correlated with the AMADEUS classification system.

RESULTS

There was a statistically significant correlation between the AMADEUS BME (bone marrow edema) subscore and the KOOS Symptoms subscore at the preoperative visit (r = 0.25, p = 0.04). No statistically significant monotonic association between the AMADEUS total score and the AMADEUS grade with pre- and postoperative KOOS subscale scores were found. Intraoperatively obtained ICRS grade did reveal a moderate correlative relation with the AMADEUS total score and the AMADEUS grade (r = 0.28, p = 0.02).

CONCLUSIONS

The novel AMADEUS classification system largely lacks correlative capacity with patient reported outcome measures in patients undergoing HTO. The MR tomographic appearance of bone marrow edema is the only parameter predictive of the clinical outcome at the preoperative visit.

Large and small fibre type sensory dysfunction in patients with cancer

Quantitative sensory testing was used to assess the prevalence of sensory dysfunction in patients with cancer, carefully screened for other risk factors for neuropathy. Large fibre type sensory function was evaluated using vibration threshold (VT) determinations while small fibre type sensory function was assessed by thermal threshold (TT) determinations. Mean VT and TT were significantly elevated in the toes but not the fingers of cancer patients. VT elevations in the toes occurred in 31% of cancer patients and in 6% of control subjects. TT elevations in the toes occurred in 43% of cancer patients and 4% of control subjects. Based on these findings it is concluded that large and small fibre type sensory dysfunction is much more common in carefully screened cancer patients than in control subjects. This sensory dysfunction is most likely to represent a neuropathy related directly or indirectly associated with cancer.