Growth hormone promotes healing of tibial fractures in the rat

Systemic response of the GH/IGF-I axis in timely versus delayed fracture healing

“…As for its central role during bone regeneration, this particularly applies to the callus remodeling process accounted for by the GH/IGF system. Various authors documented the therapeutic use of GH and IGFs on acceleration of fracture healing mostly in animal models with partly conflicting and controversial results [22][23][24][25][26]. In the few clinical trials heading systemic administration of GH in patients, the hormone failed to improve rate and quality of fracture healing [31] while it increased bone mineral content [27] and rate of return to the pre-fracture living situation in the elderly with hip fractures [28].…”

Growth hormone: does it have a therapeutic role in fracture healing?

“…In a 3-month-old rat model, maximum stiffness was observed to increase by 31% when 2.7 mg/kg GH was administered for 3 weeks, compared with 1 week [116]. In a separate study, administration of GH during the first 3 weeks of healing or throughout the entire 6-week period enhanced bone healing, but not when GH was administered in the last 3 weeks [117].…”

“…The therapeutic dose of GH has produced conflicting results in animal studies [112][113][114][115][116][117][118][119][120][121][122][126][127][128][129][130][131]144] and such contrasting data may, in part, be due to the heterogeneity of methods employed in the different animal models. Indeed, two studies were able to show the importance of dosing in terms of strength of healing, with one demonstrating that the highest systemically administered doses (2 and 10 mg/kg) exerted the most beneficial effect in rats [120], and the other observing that local delivery of 1 μg GH exhibited significantly better healing than the 0.1 and 10 μg doses in rabbits [121].…”

“…Many studies have lent further support to the role of GH in fracture healing in animal models [112][113][114][115][116][117][118][119][120][121][122]. The stimulation of secondary fracture healing was demonstrated in a recent study involving micropigs, where 100 μg/kg weight recombinant porcine (r-p) GH was systemically administered for 4 weeks leading to both increased biomechanical strength and greater callus formation compared with untreated controls [113].…”

Improved early bone-implant integration in transgenic mice overexpressing bovine growth hormone

“…Improved fracture healing or bone formation has been demonstrated in animal experiments after administration of GH [7][8][9]. In contrast other studies have found no effect on fracture healing after systemic administration of GH [10] or an effect only for GH administered early in the fracture healing process [11].…”