Case Report: Muscle Wasting during Severe Sustained Hypoxia in Two Professional Mountaineers.

PURPOSE: Chronic exposure to hypoxia can induce muscle wasting in unaccustomed individuals. Detailed assessment of the effects of hypoxia on muscle tissue adaptation in elite mountaineers has not been performed. This study aims to assess muscle volume after exposure to normobaric hypoxia. METHODS: Two professional mountaineers (A and B) participated in a 35-d intervention of graded normobaric hypoxia with the aim of 14 d exposure to 8% oxygen corresponding to 7112-m altitude. Volume of the shank, thigh, and hip muscles was assessed by magnetic resonance imaging pre- and postintervention. Dietary intake and physical activity were monitored throughout the study from food images and accelerometry analysis, together with blood analysis and anthropometric measurements. RESULTS: Hypoxia reduced total leg muscle volume by 3.3% ± 6.0% in A and by 9.4% ± 7.3% in B. A lost 288 g and B 642 g of muscle mass, whereas dietary intake only declined by ~23% in the last intervention week. Arterial oxygen saturation declined from 95% and 86% to 77% and 72% in A and B, respectively. In hypoxia, participants could not maintain their physical activity levels. Notably, muscle loss varied substantially across muscle groups amounting to 5.4% ± 3.0%, 8.3% ± 5.2%, and 4.1% ± 8.6% for hip, thigh, and shank muscles, respectively. CONCLUSIONS: Our results indicate that hypoxia and resultant reductions in physical activity and caloric intake lead to substantial loss of muscle mass that was accentuated in proximal muscle as opposed to distal muscles. Surprisingly, thigh muscle wasting during this intervention is comparable with that observed during strict 56-d bed rest.

Is Core Needle Biopsy Reliable in Differentiating Between Aggressive Benign and Malignant Radiolucent Bone Tumors?

BACKGROUND: Although there is widespread acceptance of core needle biopsy (CNB) for diagnosing solid tumors, there is reluctance by some clinicians to use CNB for aneurysmal bone cysts (ABCs) as a result of concerns of safety (bleeding, nerve injury, fracture, readmission, or infection) and reliability, particularly to rule out malignant diagnoses like telangiectatic osteosarcoma. This is especially true when CNB tissue is sent from an outside hospital, where the technique used to obtain the tissue may be spurious. QUESTIONS/PURPOSES: (1) Is CNB effective (provided adequate information to indicate appropriate surgical treatment without further open biopsy) as an initial diagnostic test for ABC? (2) Is CNB accurate (pathology consistent with the subsequent definitive surgical pathologic diagnosis) in differentiating between benign lesions such as primary or secondary ABCs and malignant radiolucent lesions such as telangiectatic osteosarcoma? (3) What are the complications of CNB? (4) Is there any difference in the effectiveness or accuracy of CNB performed at outside institutions when compared with a referral center? METHODS: A retrospective study of our musculoskeletal tumor board pathology database (1990-2016) was performed using search criteria "aneurysmal bone cyst" or "telangiectatic osteosarcoma." Only patients undergoing a CNB who proceeded to definitive surgical resection with final pathology were included. Excluding outside CNBs, CNB was performed after presentation at a musculoskeletal tumor board as a result of atypical features on imaging or history concerning for malignancy. Outside CNB tissue was reviewed by our pathologists. If there was sufficient tissue for diagnosis, the patient proceeded to definitive surgery. If not, the patient underwent open biopsy. CNB diagnosis, open biopsy results, and open surgical resection pathology were reviewed. Complications, including bleeding, infection, nerve injury, readmission, or fracture, between the CNB and definitive open surgical procedure (mean 1.6 months) were documented. CNBs were considered "effective" if they yielded pathology considered sufficient to proceed with appropriate definitive surgery without additional open biopsy. CNBs were considered "accurate" if they were effective and yielded a pathologic diagnosis that matched the subsequent definitive surgical pathology. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of obtaining a malignant diagnosis using CNB were also calculated. RESULTS: A total of 81% (59 of 73) of CNBs were effective. Ninety-three percent (55 of 59) of CNBs were classified as accurate. Diagnostic CNBs had a sensitivity and specificity of 89% (eight of nine) and 100% (51 of 51), respectively. The PPV was 1.00 and the NPV was 0.82. There were no complications. With the numbers available, there was no difference in efficacy (90% [37 of 41 versus 14 of 15]; odds ratio, 0.97 [95% confidence interval {CI}, 0.41-2.27], p = 0.94) or accuracy (92% [34 of 37 versus 13 of 14]; odds ratio, 0.87 [95% CI, 0.08-9.16], p = 0.91) between CNBs performed in house and those referred from outside. CONCLUSIONS: These data suggest that CNBs are useful as an initial diagnostic test for ABC and telangiectatic osteosarcoma. Tissue from outside CNBs can be read reliably without repeat biopsy. If confirmed by other institutions, CNB may be considered a reasonable approach to the diagnosis of aggressive, radiolucent lesions of bone. LEVEL OF EVIDENCE: Level III, diagnostic study.

The Effect of Transconjunctival Blepharoplasty on Margin Reflex Distance 2.

BACKGROUND: The objective of this study was to determine the effects of lower eyelid transconjunctival blepharoplasty (TCB) on lower eyelid position. METHODS: Transconjunctival blepharoplasty was performed alone in 15 lower eyelids without simultaneous canthoplasty or upper eyelid procedure. In this study, blepharoplasty was performed by the transconjunctival approach without removal of skin. Four eyes received TCB plus Erbium laser, two patients received TCB plus trichloroacetic acid peel (TCA), and three patients received TCB plus fat transposition. Pre-operative and post-operative margin reflex distance 1 (MRD 1) and margin reflex distance 2 (MRD 2) were compared, with MRD 1 acting as the control. RESULTS: Average time to post-operative photo was 4.6 months (1-10 months). The changes in MRD 2 and MRD 1 were compared pre- and post-operatively, and the difference reached significance by one-tailed comparison (P < 0.05). In 11/15 eyes (73 %), MRD 2 decreased post-operatively. In 6/7 eyes (86 %), lower lid scleral show was eliminated post-operatively. There were no cases of lid retraction noted. CONCLUSIONS: Transconjunctival blepharoplasty (± skin resurfacing) did not induce lid retraction but elevated the lower lid in majority of patients. Elevation of the lower lid can reduce or eliminate scleral show inferiorly, providing further cosmetic advantage. The presumed mechanism of lower lid height elevation is partial recession of the lower lid retractors during the surgical approach to the fat pockets. LEVEL OF EVIDENCE IV: This journal requires that the authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Evaluation and treatment of perioperative corneal abrasions.

Purpose. To evaluate perioperative risk factors for corneal abrasion (CA) and to determine current care for perioperative CA in a tertiary care setting. Methods. Hospital-based, cross-sectional study. In Operating Room and Post-Anesthesia Care Units patients, a comparison of cases and controls was evaluated to elucidate risk factors, time to treatment, and most common treatments prescribed for corneal abrasions. Results. 86 cases of corneal abrasion and 89 controls were identified from the 78,542 surgical procedures performed over 2 years. Statistically significant risk factors were age (P = 0.0037), general anesthesia (P < 0.001), greater average estimated blood loss (P < 0.001), eyes taped during surgery (P < 0.001), prone position (P < 0.001), trendelenburg position (P < 0.001), and supplemental oxygen en route to and in the Post-Anesthesia Care Units (P < 0.001). Average time to complaint was 129 minutes. 94% of cases had an inpatient ophthalmology consult, with an average time to consult of 164 minutes. The most common treatment was artificial tears alone (40%), followed by combination treatment of antibiotic ointment and artificial tears (35.3%). Conclusions. Trendelenburg positioning is a novel risk factor for CA. Diagnosis and treatment of perioperative corneal abrasions by an ophthalmologist typically require three hours in the tertiary care setting.