Matrix-Applied Characterized Autologous Cultured Chondrocytes Versus Microfracture: Two-Year Follow-up of a Prospective Randomized Trial.

BACKGROUND: Randomized controlled trials studying the efficacy and safety of matrix-applied characterized autologous cultured chondrocytes (MACI) versus microfracture (MFX) for treating cartilage defects are limited. PURPOSE: To compare the clinical efficacy and safety of MACI versus MFX in the treatment of patients with symptomatic cartilage defects of the knee. STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1. METHODS: Patients enrolled in the SUMMIT (Demonstrate the Superiority of MACI implant to Microfracture Treatment) trial had ≥1 symptomatic focal cartilage defect (Outerbridge grade III or IV; ≥3 cm(2)) of the femoral condyles or trochlea, with a baseline Knee Injury and Osteoarthritis Outcome Score (KOOS) pain value <55. The co-primary efficacy endpoint was the change in the KOOS pain and function subscores from baseline to 2 years. Histological evaluation and magnetic resonance imaging (MRI) assessments of structural repair tissue, treatment failure, the remaining 3 KOOS subscales, and safety were also assessed. RESULTS: Of the 144 patients treated, 137 (95%) completed the 2-year assessment. Patients had a mean age of 33.8 years and a mean lesion size of 4.8 cm(2). The mean KOOS pain and function subscores from baseline to 2 years were significantly more improved with MACI than with MFX (pain: MACI, 37.0 to 82.5 vs MFX, 35.5 to 70.9; function: MACI, 14.9 to 60.9 vs MFX, 12.6 to 48.7; P = .001). A significant improvement in scores was also observed on the KOOS subscales of activities of daily living (MACI, 43.5 to 87.2 vs MFX, 42.6 to 75.8; P < .001), knee-related quality of life (MACI, 18.8 to 56.2 vs MFX, 17.2 to 47.3; P = .029), and other symptoms (MACI, 48.3 to 83.7 vs MFX, 44.4 to 72.2; P < .001) for patients treated with MACI compared with MFX. Repair tissue quality was good as assessed by histology/MRI, but no difference was shown between treatments. A low number of treatment failures (nonresponders: MACI, 12.5% vs MFX, 31.9%; P = .016) and no unexpected safety findings were reported. CONCLUSION: The treatment of symptomatic cartilage knee defects ≥3 cm(2) in size using MACI was clinically and statistically significantly better than with MFX, with similar structural repair tissue and safety, in this heterogeneous patient population. Moreover, MACI offers a more efficacious alternative than MFX with a similar safety profile for the treatment of symptomatic articular cartilage defects of the knee.

Functional reconstruction of a chronically ruptured extensor apparatus after patellectomy.

Rupture of the knee extensor mechanism after previous patellectomy is rare. A treatment protocol therefore is not available. This article presents a new and easy technique using a gracilis-semitendinosus tendon autograft for successful reconstruction of a ruptured knee extensor mechanism after previous patellectomy.

Measuring activity limitations in walking: development of a hierarchical scale for patients with lower-extremity disorders who live at home.

OBJECTIVE: To develop a hierarchical scale that measures activity limitations in walking in patients with lower-extremity disorders who live at home. DESIGN: Cross-sectional study. SETTING: Orthopedic workshops and outpatient clinics of secondary and tertiary care centers. PARTICIPANTS: Patients (N=981; mean age +/- standard deviation, 58.6+/-15.4 y; 46% men) living at home, with different lower-extremity disorders: stroke, poliomyelitis, osteoarthritis, amputation, complex regional pain syndrome type I, and diabetic and degenerative foot disorders. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: (1) Fit of the monotone homogeneity model, indicating whether items can be used for measuring patients; (2) fit of the double monotonicity model, indicating invariant (hierarchical) item ordering; (3) intratest reliability, indicating repeatability of the sum score; (4) robustness, addressing the clinimetric properties within subgroups of patients; and (5) differential item functioning, addressing the validity of comparisons between subgroups of patients. RESULTS: Thirty-five of 41 dichotomous items had (1) good fit of the monotone homogeneity model (coefficient H=.50), (2) good fit of the double monotonicity model (coefficient H(T)=.33), (3) good intratest reliability (coefficient rho=.95), (4) satisfactory robustness (within subgroups of patients defined by age, sex, and diagnosis), and (5) some differential item functioning (6 items in amputees compared with nonamputees). CONCLUSIONS: A hierarchical scale, with excellent scaling characteristics, was developed to measure activity limitations in walking in patients with lower-extremity disorders who live at home. The measurements should be interpreted cautiously when making comparisons between amputees and nonamputees.