ICD-10-CM > M00-M99 > M20-M25 > M22 > M22.8 > M22.8X M22.8X Other disorders of patella Non-Billable/Non-Specific Codes M22.8X1Other disorders of patella, right kneeM22.8X2Other disorders of patella, left kneeM22.8X9Other disorders of patella, unspecified knee