Management of Full‑Thickness Chondral Fissuring of the Knee

Indications for Microfracture

First‑line surgical treatment for focal, contained full‑thickness lesions smaller than 4 cm² in patients with minimal osteoarthritis (Tönnis grade ≤ 1). 1
Microfracture remains the preferred option for lesions measuring 2–6 cm² when located on the acetabulum (applicable to analogous knee lesions). 1

Debridement – Remove all friable cartilage with a shaver to achieve a stable rim. 2
Peripheral edge creation – Use ringed curettes to fashion a perpendicular, well‑attached cartilage margin around the defect. 2
Subchondral perforation – Insert an awl to create 3–4 mm‑deep holes spaced 3–4 mm apart, preserving intervening bone bridges for structural support. 2
Preservation of bone bridges – Maintain subchondral bone columns between holes to protect the underlying plate. 2
Biological mechanism – The perforations allow pluripotent marrow cells and growth factors to fill the defect, forming fibrocartilage repair tissue. 2

Second‑look arthroscopy shows a mean defect fill of 93 % ± 17 % with macroscopically good‑quality fibrocartilage. 1

Mosaicplasty or single‑plug osteochondral allograft should be considered for femoral‑head‑type lesions measuring 2–6 cm². 1
Conversion to total joint arthroplasty is advised when defect size exceeds 6 cm² and the patient is an appropriate surgical candidate. 1

The procedure must not be performed on partial‑thickness chondral delamination with an intact basal layer, because exposed subchondral bone is required for marrow‑derived repair. 1
Microfracture is inappropriate for patients with advanced osteoarthritis (Tönnis grade > 1) or lesions lacking an exposed subchondral plate. 1

Acetaminophen is the preferred first‑line oral analgesic; its benefit is modest and uncertain. 1
NSAIDs may be added when acetaminophen is insufficient, but long‑term use carries gastrointestinal and cardiovascular risks. 1
Intra‑articular anesthetic and steroid injections serve both diagnostic and therapeutic roles. 3
Patellofemoral braces are conditionally recommended for patients with significant functional limitation, instability, or pain. 1
Kinesiotaping is conditionally recommended for knee involvement. 1
Effective bracing requires clinician expertise in selecting and fitting the appropriate device. 1

Stem‑cell injections for cartilage regeneration are not recommended due to heterogeneous products and low‑quality supporting evidence. 1

Long‑term monitoring is essential because untreated or inadequately treated chondromalacia can progress to osteoarthritis. 1
Patients with more extensive cartilage damage experience less favorable outcomes and may need additional interventions. 3
A common pitfall is attempting microfracture on lesions with an intact basal cartilage layer or on knees with advanced osteoarthritis; success requires an exposed and intact subchondral bone plate. 2