M92.41 identifies juvenile osteochondrosis affecting the patella of the right knee — a developmental chondropathy of the kneecap's ossification center occurring in skeletally immature patients.

Documentation tips

What should appear in the chart to support M92.41.

Source · Editorial brief grounded in 5 cited references ↓

• Explicitly document 'right knee' or 'right patella' — laterality must appear in the clinical note, not just the imaging report, to support M92.41 over M92.40.
• Record the patient's skeletal maturity status (open growth plates, Tanner stage, or bone age) to substantiate the 'juvenile' designation and distinguish from adult chondropathy codes.
• Include imaging findings: plain radiograph or MRI evidence of patellar ossification irregularity, fragmentation, or avascular change that supports osteochondrosis rather than a traumatic fracture or chondromalacia.
• Note any conservative treatment history (activity restriction, physical therapy, bracing) if surgical intervention is being planned — payer medical necessity review commonly requires documented failed conservative care.
• If bilateral disease is present, document each side separately and assign both M92.41 and M92.42; there is no bilateral code in the M92.4 subcategory.

Related CPT procedures

Procedure codes commonly billed with M92.41. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

Common coding pitfalls

The recurring mistakes coders make with M92.41 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

• Using the non-billable parent M92.4 or M92.40 (unspecified) when the record clearly identifies the right knee — always drill down to M92.41 for reimbursement.
• Confusing patellar osteochondrosis (M92.41) with tibial tubercle osteochondrosis (Osgood-Schlatter, M92.52x) — both present with anterior knee pain in adolescents but involve different anatomical structures and codes.
• Applying a 7th-character encounter extension (A, D, S) to M92.41 — M-codes in this range do not use the injury-encounter extension scheme; adding one creates an invalid code.
• Assigning an adult chondropathy or chondromalacia code (e.g., M22.4x) when the patient is a skeletally immature juvenile — juvenile osteochondrosis has its own dedicated subcategory under M92.
• Failing to add M92.42 as a secondary code when bilateral disease is documented — coders sometimes code only the symptomatic side, leaving the contralateral diagnosis uncaptured.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

Sibling codes

Other billable codes under M92.4 (laterality / anatomic variants).