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

Study design

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 cm². 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.