Table 1 Overview of the predefined diagnosis and surgical procedures using the ICD-10 and NCSP codes

M17 Gonarthrosis

NGA11 Endoscopic exploration

M22.4 Chondromalacia patella

NGA12 Open exploration

M23.4 Loose body in the knee

NGF21 Endoscopic fixation of corpus librum

M23.8 Other internal derangements of knee

NGF22 Open fixation of corpus librum

M23.9 Internal derangement of knee, unspecified

NGF31 Endoscopic resection of corpus librum

M24.1 Other articular cartilage disorder

NGF32 Open resection of corpus librum

M24.8 Other specific joint derangements, not elsewhere classified

NGF91 Other endoscopic procedure on synovia or articular cartilage

M24.9 Joint derangements, unspecified

NGF92 Other open procedure on synovia or articular cartilage

M25.5 Pain in joint

NGG29 Other arthroplasty without prosthesis

M25.8 Other specified joint disorders

NGG99 Other excision, reconstruction or arthrodesis of knee

M25.9 Joint disorder, unspecified

NGH41 Endoscopic removal of corpus librum

M92.4 Juvenile osteochondrosis, unspecified

NGH42 Open removal of corpus librum

M92.8 Other specified juvenile osteochondrosis

NGH91 Other endoscopic procedure

M92.9 Juvenile osteochondrosis, unspecified

NGH92 Other open procedure

M93.2 Osteochondritis dissecans

NGK09 Excision of bony fragment in knee

M93.8 Other specified osteochondropaties

NGK19 Resection or excision of bone in knee

M93.9 Osteochondropathy, unspecified

NGK29 Fenestration or drilling of bone in knee

S83.3 Tear of articular cartilage of knee, current

NGN09 Autotransplantation of bone to knee

NGN49 Transplantation of cartilage, periost or fascia to knee

NGN99 Other transplantation to knee

YNA20 Removal of cartilage for transplantation

ZZG00 Cartilage transplantation