ICD-10-CM · Knee

M67.52

M67.52 identifies plica syndrome specifically affecting the left knee — irritation or inflammation of a synovial membrane fold within the left knee joint, classified under other disorders of synovium and tendon.

Verified May 8, 2026 · 5 sources ↓

Status
Billable
Chapter
13
Related CPT
8
Region
Knee
Drawn from CDCICD10DataAAPCMdclarityCMS

Documentation tips

What should appear in the chart to support M67.52.

Source · Editorial brief grounded in 5 cited references ↓

  • Explicitly name 'left knee' in the assessment — 'plica syndrome' without laterality forces a drop to M67.50 (unspecified).
  • Record physical exam findings that support the diagnosis: medial knee tenderness, palpable thickened plica band, clicking or pseudolocking with flexion.
  • Note MRI or ultrasound findings when imaging is obtained — describe synovial fold thickening or impingement to justify medical necessity.
  • Document the conservative treatment course (duration, modalities tried, response) before arthroscopic intervention to support surgical necessity.
  • If both knees are symptomatic, document each side separately; report M67.51 and M67.52 together — there is no bilateral plica syndrome code.

Related CPT procedures

Procedure codes commonly billed with M67.52. 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 M67.52 and adjacent codes.

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

  • Defaulting to M67.50 (unspecified knee) when the note clearly documents the left side — always assign M67.52 when laterality is present.
  • Confusing plica syndrome with meniscal or patellofemoral codes; plica is a synovial membrane disorder under M67.5, not a cartilage or meniscus category.
  • Reporting M67.52 with a duplicate symptom code (e.g., M25.562 left knee pain) when pain is integral to the plica diagnosis — the symptom does not add specificity and is redundant.
  • Selecting 29881 (meniscectomy) as the arthroscopic CPT when only plica resection was performed — 29875 (synovectomy, limited) is the correct pairing for isolated plica shelf resection.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

Use M67.52 when the provider has documented plica syndrome with explicit left-side laterality. Plica syndrome involves pathologic thickening or inflammation of a remnant synovial fold (plica) inside the knee joint, producing medial knee pain, clicking, pseudolocking, or a palpable band. The condition is distinct from meniscal pathology, chondromalacia, and patellofemoral syndrome — all of which can mimic it clinically.

M67.52 sits within the M67.5 family: M67.51 is right knee, M67.52 is left knee, and M67.50 is unspecified knee. Drop to M67.50 only when the operative or clinical note genuinely omits laterality — do not default to unspecified when the chart clearly names the left side. There is no bilateral code in this family; if both knees are affected, report M67.51 and M67.52 together.

The diagnosis typically follows failed conservative care (NSAIDs, physical therapy, activity modification) and is confirmed by clinical examination findings — palpable plica, medial joint line tenderness — often supported by MRI showing a thickened synovial band. Arthroscopic confirmation is the gold standard. Code M67.52 applies across the care continuum: office evaluation, imaging workup, injection, and arthroscopic plica resection encounters.

Sibling codes

Other billable codes under M67.5 (laterality / anatomic variants).

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01What is the difference between M67.52 and M67.50?
M67.52 specifies the left knee; M67.50 is unspecified knee. Use M67.52 whenever the provider documents left-side laterality — which is the standard of care in any orthopedic note. M67.50 should be rare in a properly documented chart.
02Is there a bilateral plica syndrome code?
No. The M67.5 family has no bilateral option. If both knees are diagnosed with plica syndrome, report M67.51 (right) and M67.52 (left) on the same claim with appropriate modifiers.
03Which CPT code pairs with M67.52 for arthroscopic plica resection?
29875 (arthroscopy, knee, surgical; synovectomy, limited — e.g., plica or shelf resection) is the most specific code for isolated plica excision. Use 29876 if the synovectomy extends to two or more compartments. Do not default to 29881 unless a meniscectomy was also performed.
04Can M67.52 be used at the initial evaluation visit before a confirmed diagnosis?
Only if the provider documents plica syndrome as the working diagnosis. If the provider is still ruling out other causes, code the presenting signs (e.g., M25.562 left knee pain) until plica syndrome is confirmed in the assessment.
05Does M67.52 require a 7th character extension?
No. M67.52 is an M-code (musculoskeletal, non-injury) and does not use 7th-character encounter extensions (A/D/S). Those extensions apply to S-code injury categories only.
06What MS-DRGs does M67.52 map to for inpatient coding?
M67.52 groups to MS-DRG 557 (Tendonitis, myositis and bursitis with MCC) or 558 (Tendonitis, myositis and bursitis without MCC) under MS-DRG v43.0, per the ICD-10-CM tabular grouping data.
07Can knee pain (M25.562) be coded alongside M67.52?
Generally no. Pain is considered integral to the plica syndrome diagnosis and should not be coded separately as an additional symptom code when M67.52 is the confirmed diagnosis.

Mira AI Scribe

The Mira AI Scribe captures left-side laterality, medial knee tenderness on palpation, presence of a palpable plica band, clicking or pseudolocking with range of motion, MRI findings of synovial fold thickening, and prior conservative treatment history. Capturing these specifics prevents a downcode to M67.50 (unspecified knee) and supports medical necessity documentation for arthroscopic plica resection.

See how Mira captures M67.52 documentation

Related ICD-10 codes

Ready?

Ready to transform your orthopedic practice?

See how orthopedic practices are running documentation, billing, and operations on a single voice-first platform.

Get started for free