Tendon Transfer versus Allograft Reconstruction in Progressive Collapsing Foot Deformity.

The posterior tibial tendon (PTT) is the principal dynamic stabilizer of the medial longitudinal arch of the foot. The basic goal of surgically reconstructing PCFD is to restore the foot's medial longitudinal arch, often through a combination of bony and soft tissue procedures. While the FDL transfer has long been the gold standard for reconstruction, allograft reconstruction of the PTT has recently been increasing in popularity.

Placement of an Intramedullary Nail for the Treatment of Proximal Ulnar Fractures.

INTRODUCTION: The fixation of olecranon fractures with intramedullary olecranon nails has been demonstrated to be an effective treatment option that may result in decreased soft-tissue irritation. STEP 1 POSITIONING AND APPROACH: Proper positioning of the patient during this procedure allows for improved access to the fracture and increased accessibility for fluoroscopy. STEP 2 REDUCE THE FRACTURE: Reduce and provisionally hold the fracture following a limited periosteal elevation. STEP 3 REAM THE OLECRANON AND PLACE THE NAIL: The olecranon is then reamed, and the intramedullary nail is inserted. STEP 4 INSERT THE SCREW: Place proximal interlocking screws using the targeting system. STEP 5 CLOSE THE WOUND: Close the wound with subdermal sutures and either staples or interrupted nylon horizontal mattress sutures. RESULTS: A total of twenty-eight patients with unstable olecranon fractures were treated with intramedullary olecranon nailing in our series, and union was achieved in all patients by eight weeks.IndicationsContraindicationsPitfalls & Challenges.

HK-2 human renal proximal tubule cells as a model for G protein-coupled receptor kinase type 4-mediated dopamine 1 receptor uncoupling.

HK-2 human renal proximal tubule cells (RPTC) are commonly used in the in vitro study of "normal" RPTCs. We discovered recently that HK-2 cells are uncoupled from dopamine 1 receptor (D(1)R) adenylyl cyclase (AC) stimulation. We hypothesized that G protein-coupled receptor kinase type 4 (GRK4) single nucleotide polymorphisms may be responsible for the D(1)R/AC uncoupling in HK-2. This hypothesis was tested by genotyping GRK4 single nucleotide polymorphisms, measuring D(1)-like receptor agonist (fenoldopam)-stimulated cAMP accumulation, quantifying D(1)R inhibition of sodium transport, and testing the ability of GRK4 small interfering RNA to reverse the D(1)R/AC uncoupling. We compared HK-2 with 2 normally coupled human RPTC cell lines and 2 uncoupled RPTC cell lines. The HK-2 cell line was found to have 4 of 6 potential GRK4 single nucleotide polymorphisms known to uncouple the D(1)R from AC (namely, R65L, A142V, and A486V). AC response to fenoldopam stimulation was increased in the 2 normally coupled human RPTC cell lines (FEN: 2.02+/-0.05-fold and 2.33+/-0.19-fold over control; P<0.001; n=4) but not in the 2 uncoupled or HK-2 cell lines. GRK4 small interfering RNA rescued the fenoldopam-mediated AC stimulation in the uncoupled cells, including HK-2. The expected fenoldopam-mediated inhibition of sodium hydrogen exchanger type 3 was absent in HK-2 (n=6) and uncoupled RPTC cell lines (n=6) but was observed in the 2 normally coupled human RPTC cell lines (-25.41+/-4.7% and -27.36+/-2.70%; P<0.001; n=6), which express wild-type GRK4. Despite the fact that HK-2 cells retain many functional characteristics of RPTCs, they are not normal from the perspective of dopaminergic function.