We measured diffusing capacities for carbon monoxide (DLCO) and nitric oxide, lung volume, and cardiac output by a rebreathing technique at two alveolar O2 tensions (PAO2) at rest and exercise. Membrane diffusing capacity for CO (DMCO) and VC were estimated from DLCO by the Roughton-Forster (RF) method and also from simultaneous lung diffusing capacity for NO and DLCO measured at one O2 tension (modified RF method). Estimates by these methods agreed closely in normal subjects (Tamhane et al., Chest 2001;120:1850-1856). Using these methods, we studied patients with stages II-III pulmonary sarcoidosis to determine (1) whether the modified RF method accurately estimates DMCO and VC in parenchymal disease and (2) whether sarcoidosis alters recruitment of diffusing capacity with respect to cardiac output. In patients, DMCO and VC estimated by the two methods agreed closely. DMCO was disproportionately reduced relative to VC at any given cardiac output, and the slope of the relationship between DLCO and cardiac output was moderately, though significantly, below normal. We conclude that in sarcoidosis (1) the modified RF method provides comparable estimates of DMCO and VC as the standard RF method and (2) the limitation to diffusive gas transport resides primarily in the membrane barrier, although recruitment of microvascular reserves is also modestly impaired.

Lateral hemiepiphysiodesis may be a valuable treatment option for non-morbidly obese patients with less severe adolescent tibia vara, but it is likely to fail in older adolescents with a high body mass index and greater deformity.

Articular cartilage defects of the knee have been shown to cause pain, swelling, decreased function, and suboptimal athletic performance. Treatment of elite-level athletes presenting with full-thickness chondral defects of the knee continues to be a challenge for orthopedic surgeons. The purpose of this study was to document outcomes in elite professional alpine ski racers after microfracture surgery. This study was approved by an institutional review board. All patients who competed in professional ski races recognized by International Ski Federation and had a full-thickness knee articular cartilage defect, treated with microfracture, by a single surgeon, were included in the study. All data were collected prospectively. At minimum 2 years following microfracture, all patients completed a questionnaire, including Lysholm score, Tegner activity scale, and patient satisfaction with outcome. Minimum 2-year follow-up was available for 18 of 20 skiers (90%) at an average follow-up of 77 months (range, 24-255 months). Size of knee articular cartilage defect was larger in males (195 mm(2)) compared with females (155 mm(2)); however, this difference was not statistically significant (p > 0.05). Median postoperative Tegner activity scale was 10 (range, 4-10). Mean postoperative Lysholm score was 86 (range, 41-100). Median postoperative patient satisfaction score was 10 (range, 9-10). Out of the 20 skiers, 19 (95%) returned to competitive skiing. The age of the skier who did not return was 28 years. The average time from surgery to return to competition was 13.4 months (range, 0.5-25.3 months). Average end-of-season overall World Cup ranking was calculated for the nine skiers before and after surgery. Of these nine skiers, six had an improved average overall World Cup ranking after microfracture. In this study, patient satisfaction with outcome and function were high following microfracture of full-thickness chondral lesions of the knee. Nearly all skiers returned to full competition. Microfracture is an acceptable treatment option for elite skiers who have full thickness articular cartilage lesions of the knee.

The purpose of this study was to document outcomes following microfracture for full-thickness cartilage defects of the knee in adolescents. Our hypothesis was that patients aged 18 years or less would have excellent outcomes and function following microfracture of full-thickness knee articular cartilage defects. This study was approved by the Institutional Review Board. Patients < 19 years old with full-thickness knee articular cartilage defects treated with microfracture between January 1992 and June 2008 were identified. Surgical, demographic data, Lysholm score, Tegner activity scale, and patient satisfaction were collected prospectively. A total of 26 patients (14 females, 12 males) met inclusion criteria. Average age was 16.6 years (range: 12-18.9 years). Ninety-six percent of lesions were patellar (37%) or femoral condyle defects (medial 26%, lateral 33%). Minimum 2-year follow-up was obtained in 22/26 patients (85%) with average follow-up of 5.8 years (range: 2.0-13.3 years). Average postoperative Lysholm score was 90 (range: 50-100). Median Tegner scale was 6 (range: 2-10). Median patient satisfaction with outcome was 10 (range: 1-10). Lysholm correlated with Tegner scale (rho = 0.586; p = 0.011) and patient satisfaction (rho = 0.70; p = 0.001). Average postoperative Lysholm score in males was 93 and 86 in females (p = 0.22). One patient underwent revision microfracture. This study showed that adolescent patients who underwent microfracture for treatment of full-thickness knee chondral defects demonstrated increased activity levels and excellent function following surgery.

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