SPECT scan is a reliable tool for selection of patients undergoing unicompartmental knee arthroplasty.

Purpose: Was to determine the relationship between pre-operative SPECT and intra-operative assessments of tibio-femoral chondral changes.

Methods: One hundred cases had been selected on the following criteria: (1) marked Tc-99 m uptake on the medial compartment and (2) its normal uptake laterally. The cartilage macroscopic condition of tibio-femoral compartments were then recorded during the surgery.

Results: A total of 73% of Grade 0, 24% of Grade I, and 3% of Grade II chondral injuries were detected laterally; 100% of Grade IV chondral lesions were detected medially. Statistically very significant relationship was demonstrated between SPECT and the mcroscopic cartilage condition.

Conclusions: SPECT bone scan provides very useful information regarding the degree of osteoarthritis in knee weight-bearing compartments for pre-operative planning.