Michael E. Pannunzio

A new method of selecting Schwann cells from adult mouse sciatic nerve

We describe a method of using laminin for the selection and purification of Schwann cells in vitro. We also studied the viability of the selected cells suspended in alginate beads both in vitro and in vivo. We observed that the homogeneity of the Schwann cell culture increased with each round of laminin selection and reached 85-90% after five passages. The viability of cells after incubation within an alginate bead in vivo was between 73 and 76% compared with greater than 90% viability for cells that were maintained in monolayer culture. This new method of serial selection using laminin-coated surfaces has optimized the purification of a Schwann cell culture expanded from cells harvested from the adult sciatic nerve of a mouse. This method has the advantage of being technically easier than other methods described and results in a Schwann cell culture that is 80-90% homogenous.

Interposition arthroplasty with bone-tendon allograft: a technique for treatment of the unstable sternoclavicular joint.

Sternoclavicular joint instability is an uncommon but challenging clinical problem for the orthopaedic surgeon. Although most cases can be treated nonoperatively with minimal long-term pain or functional limitation, a small percentage may require surgical intervention. This includes chronic anterior instability associated with persistent pain or functional limitation as well as irreducible or recurrent posterior instability. Although numerous procedures have been described for treatment of the unstable sternoclavicular joint, the optimal method for stabilization has not been determined. Here we describe a technique using Achilles tendon allograft to create an interpositional arthroplasty and briefly present 3 illustrative cases in which we performed the procedure. We believe this method effectively stabilizes the joint, restores function, relieves pain, and has applications for traumatic sternoclavicular instability as well as instability related to other etiologies.

Treatment of chronic nonunions of the humerus with free vascularized fibula transfer: a report of thirteen cases.

Chronic nonunions of the humerus remain a challenging problem. We reviewed 13 cases of chronic nonunion of the humerus resulting from trauma or osteomyelitis treated with vascularized fibula transfer after failure of conventional treatment. Patient averages were 35 years of age, follow-up of 19 months, and 4.2 prior operations. Healing was obtained in 12 of 13 (92%) patients with an average healing time of 18 weeks and graft length of 12.5 cm. In total, 11 of 12 (91%) patients who united had good to excellent range of motion of their shoulder and elbow. There were eight complications in 7 of 13 patients (54%). Two patients developed fractures of the graft, and three had superficial infections at the harvest site requiring operative debridement. Two patients had median neurapraxia that resolved by 4 months. Two patients complained of intermittent pain at the donor site. No significant correlations were found between time to heal and other covariates.

Locked Metacarpophalangeal Joint in a 20-Year-Old Football Player A Case Report

a common occurrence when caused by stenosing flexor tenosynovitis or “trigger finger” (Figure 1). A far less common problem is the locked metacarpophalangeal (MP) joint. This diagnosis was first described by Langenskiold, who reported the cause as radial collateral ligament entrapment by the metacarpal head (Figure 2). Other causes for locking of the MP joint have been described, such as volar metacarpal head osteophytes impinging on the collateral ligaments or palmar plate, entrapment of a sesamoid bone in the MP joint, irregularities of the articular surfaces of the MP joint, tears of the collateral ligaments or palmar plate, intra-articular loose bodies, abnormal soft tissue bands around the joint, and entrapment of the first dorsal interosseous tendon on an exostosis of the metacarpal head. We describe a 20-yearold football player who was believed to have a trigger finger and was later found to have a locking MP joint of his index finger caused by a prominent radial ridge of the metacarpal head entrapping the accessory collateral ligament.