The Palmaris Longus and Its Association with Carpal Tunnel Syndrome.

Background The palmaris tendon inserts into the palmar fascia and is positioned in close association with the transverse carpal ligament. Loading of this tendon has been demonstrated to increase carpal tunnel pressures. Purpose The purpose of this study was to determine if a relationship exists between the palmaris tendon, carpal tunnel syndrome (CTS), and handedness. The sensitivity, specificity, positive predictive value, and negative predictive value for Schaeffer's test were calculated. Methods A retrospective review of patient charts undergoing endoscopic carpal tunnel release was performed. Rates of palmaris longus agenesis (PLA) were compared to a population matched data set. Statistical analysis was performed using a one-proportion z -test. Schaeffer's test for the palmaris longus tendon was performed on all patients and compared to intraoperative confirmation. Results A total of 520 carpal tunnel releases were performed in 389 consecutive patients. The frequency of PLA in this surgical cohort was significantly lower compared to the population matched dataset. No correlation between handedness and laterality of CTS or PLA was found. Schaeffer's test was evaluated to yield sensitivity (93.6%), specificity (100%), positive predictive value (100%), and negative predictive value (50.8%). Conclusion The palmaris tendon was more prevalent in a population of patients undergoing carpal tunnel release. These findings can be used to provide further insight into the pathophysiology of CTS. While Schaeffer's test was accurate in detecting the palmaris longus tendon, a negative test was frequently incorrect. Further imaging is recommended in patients with a negative Schaeffer's test when the palmaris longus is desired for surgical utilization. Level of Evidence This is a Level III, prognostic study.

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging pathogen in orthopaedics.

Staphylococcus aureus (S aureus) remains one of the most common pathogens for skin and soft-tissue infections encountered by the orthopaedic surgeon. Community-acquired methicillin-resistant S aureus (CA-MRSA) has become increasingly prevalent, particularly among athletes, children in day care, homeless persons, intravenous drug users, men who have sex with men, military recruits, certain minorities (ie, Alaskan Natives, Native Americans, Pacific Islanders), and prison inmates. Risk factors include antibiotic use within the preceding year, crowded living conditions, compromised skin integrity, contaminated surfaces, frequent skin-to-skin contact, shared items, and suboptimal cleanliness. When a patient presents with a skin or soft-tissue infection, the clinician should determine whether an abscess or other infection needs to be surgically incised and drained. Cultures should be performed. When the patient is a member of an at-risk group or has any of the risk factors for CA-MRSA, beta-lactam antibiotics (eg, methicillin) are no longer a reasonable choice for treatment. Empiric treatment should consist of non-beta-lactam antibiotics active against CA-MRSA.

Nonoperative treatment for a double dislocation of the thumb metacarpal: a case report.

Double dislocations of the thumb are rare injuries. Those reported in the English literature have all been treated operatively except one. We report the second case of a double dislocation of a thumb involving the metacarpophalangeal joint and carpometacarpal joint treated nonoperatively. Two-year results reveal a stable, pain free thumb with no evidence of arthritis or subluxation.

Longitudinal radioulnar dissociation: identification and treatment of acute and chronic injuries.

In this article we describe the fundamental concepts that were established by Essex-Lopresti over 50 years ago and explore the current concepts in anatomy, biomechanics, diagnosis, and treatment for longitudinal radioulnar dissociation. Moreover, we present encouraging results for treating chronic injuries to the IOM achieved by bone-ligament-bone (BLB) reconstruction using a patellar tendon graft, giving hope for this seemingly unforgiving injury. A treatment algorithm is also provided to aid in the management of acute and chronic longitudinal radioulnar dissociation.

Vitamin C protects low-density lipoprotein from homocysteine-mediated oxidation.

Homocysteine, an atherogenic amino acid, promotes iron-dependent oxidation of low-density lipoprotein (LDL). We investigated whether vitamin C, a physiological antioxidant, could protect LDL from homocysteine-mediated oxidation. LDL (0.2 mg of protein/ml) was incubated at 37 degrees C with homocysteine (1000 microM) and ferric iron (10-100 microM) in either the absence (control) or presence of vitamin C (5-250 microM). Under these conditions, vitamin C protected LDL from oxidation as evidenced by an increased lag time preceding lipid diene formation (> or = 5 vs. 2.5 h for control), decreased thiobarbituric acid-reactive substances accumulation (< or = 19 +/- 1 nmol/mg when vitamin C > or = 10 microM vs. 32 +/- 3 nmol/mg for control, p <.01), and decreased lipoprotein anodic electrophoretic mobility. Near-maximal protection was observed at vitamin C concentrations similar to those in human blood (50-100 microM); also, some protection was observed even at low concentrations (5-10 microM). This effect resulted neither from altered iron redox chemistry nor enhanced recycling of vitamin E in LDL. Instead, similar to previous reports for copper-dependent LDL oxidation, we found that vitamin C protected LDL from homocysteine-mediated oxidation through covalent lipoprotein modification involving dehydroascorbic acid. Protection of LDL from homocysteine-mediated oxidation by vitamin C may have implications for the prevention of cardiovascular disease.