Clinical outcome following the first-line, single lesion microfracture at the knee joint.

CASE SERIES: Level of evidence, 4.
BACKGROUND: Arthroscopic microfracture of chondral defects across the knee joint is a frequent treatment modality. There is only limited information on the clinical outcome in patients without previous surgery and single lesions.
PURPOSE: Evaluation of clinical outcome following microfracture in patients without previous surgery and single lesions and identification of prognostic factors.
METHODS: Inclusion criteria were patients with single-lesion knee joint first-line microfracturing at minimum 2 years postoperatively. Charts were reviewed to identify patient and defect characteristics. Clinical outcome was evaluated by IKDC and Lysholm knee scores, Tegner activity scale and a numeric analogue scale (NAS) for function and pain (10 = highest possible function, no pain).
RESULTS: Totally, 145 patients (age at operation 47.92 ± 15.7) met inclusion criteria. Average defect size was 2.7 ± 1.9 cm(2). Postoperatively, IKDC was 73.1 ± 18.5, Lysholm 77.6 ± 19.1, Tegner 4.5 ± 1.7, NAS pain 6.5 ± 2.6 and NAS function 6.4 ± 2.3. Significantly better clinical outcome was observed in male patients than in female patients. Regression analysis including all patient and defect characteristics highlighted that singly the parameter shorter symptom duration (P = 0.018) significantly predicted an improved postoperative clinical outcome.
CONCLUSION: Microfracturing results in a satisfying clinical outcome, but no full recovery in patients without previous surgery and single lesions. Specific parameters facilitate outcome prognosis and therefore may aid in indicating surgery.