Factors Expressed in an Animal Model of Anteroinferior Glenohumeral Instability.

Background: There is little information on the molecular factors important in healing and changes that occur in the glenoid labrum in response to injury. Using a novel animal model of acute anterior shoulder dislocation, this study characterizes the factors expressed in the glenoid labrum in response to injury and correlates their expression to glenohumeral stability.

Purpose: To study the response of the glenoid labrum to injury both biomechanically and with immunohistochemical testing.

Long head biceps tenodesis with a knotless cinch suture anchor: a biomechanical analysis.

Purpose: The purpose of this study was to evaluate the initial fixation strength of 3 techniques of arthroscopic tenodesis of the long head of the biceps (LHB).

Methods: Eighteen human cadaveric shoulders were randomly assigned to one of 3 simulated arthroscopic biceps tenodesis techniques-simple suture (SS), Krakow stitch (KS), or lasso loop (LL)-combined with a knotless fixation implant (3.5-mm Piton Anchor; Tornier, Minneapolis, MN).

Glenohumeral arthritis and total shoulder replacement.

Shoulder replacement surgery is a reliable procedure that provides predictable results in patients with all types of glenohumeral arthritis. When performed by an experienced surgeon for the right indications, and with appropriate physical therapy, dramatic improvements in pain and function are seen in the majority of patients. With the recent availability of the reverse prosthesis, even patients with rotator cuff deficiency may have pain relief and restoration of shoulder function after reverse shoulder arthroplasty.

Elbow arthritis and total elbow replacement.

Elbow arthritis is a relatively uncommon condition that can be successfully managed with non-operative and operative methods. The extent of pathologic involvement and severity of pain and dysfunction are the most important factors in selecting treatment. Arthroscopic, open, and arthroplasty surgery options provide successful outcomes in most cases.

Teriparatide (1-34 human PTH) regulation of osterix during fracture repair.

Based on remarkable success of PTH as an anabolic drug for osteoporosis, case reports of off-label use of teriparatide (1-34 PTH) in patients with complicated fractures and non-unions are emerging. We investigated the mechanisms underlying PTH accelerated fracture repair. Bone marrow cells from 7 days 40 microg/kg of teriparatide treated or saline control mice were cultured and Osx and osteoblast phenotypic gene expression assessed by real-time RT-PCR in these cells.

Osterix/Sp7 regulates mesenchymal stem cell mediated endochondral ossification.

We investigated the expression and regulation of the zinc finger protein Osterix (Osx) during endochondral ossification in mice. In studies to determine the temporal and spatial regulation of Osx mRNA and protein during embryogenesis we found it to be present throughout development, but its expression is restricted to the immature chondro/osteoprogenitor cells and mature osteoblasts, excluding hypertrophic chondrocytes. Using a fracture model, we show a consistent pattern of Osx protein expression in mesenchymal progenitor cells in the periosteum and immature chondrocytes and osteoblasts embedded in the fracture callus.