Introduction. Stress fractures in the foot are common; the common practice is to look for any factor in the history or for any foot deformity that could cause the fracture. Once found, it is common to treat the fractures without further investigations. The aim of this study is to assess if we are missing any underlying metabolic disorder associated with such injury. Materials and methods. We studied 34 sequential cases referred for chronic foot pain. Stress fractures were confirmed either by classic x-ray's features or MRI. Clinical examination and further tests were performed for Vitamin D levels, Thyroid function, PTH, DEXA scan, Biochemical and bone profile. All stress fractures were treated conservatively. Results. Mean age was 50 (13–72) (22 Females, 9 Males), 29 patients were fit and healthy ASA 1, 5 cases were ASA 2. 12 cases presented with a precipitating event. 14 cases had a minor foot deformity (such as hallux valgus of minor pes planus). mean BMI 27.6. The blood tests newly diagnosed: 17 Vitamin D deficiencies cases, 2 hyperparathyroidism cases, one case of Cushing's Syndrome secondary to adrenal adenoma and one case of delay in puberty in addition to 3 osteoporosis cases. All fractures responded to conservative means of treatment and none needed surgical interventions. Discussion. The study shows that the incidence of endocrinological disorders is patients presenting with stress fractures is much higher than the incidence in the general population; for example the incidence of Cushing's syndrome is 1 per 130000 individuals while in our series was 1 per 34. This study raises the question if all patients presetting with stress fractures should be investigated for endocrinological disorders

The AO Foundation advocates the use of partially threaded lag screws in the fixation of fractures of the medial malleolus. However, their threads often bypass the radiodense physeal scar of the distal tibia, possibly failing to obtain more secure purchase and better compression of the fracture.

We therefore hypothesised that the partially threaded screws commonly used to fix a medial malleolar fracture often provide suboptimal compression as a result of bypassing the physeal scar, and proposed that better compression of the fracture may be achieved with shorter partially threaded screws or fully threaded screws whose threads engage the physeal scar.

We analysed compression at the fracture site in human cadaver medial malleoli treated with either 30 mm or 45 mm long partially threaded screws or 45 mm fully threaded screws. The median compression at the fracture site achieved with 30 mm partially threaded screws (0.95 kg/cm² (interquartile range (IQR) 0.8 to 1.2) and 45 mm fully threaded screws (1.0 kg/cm² (IQR 0.7 to 2.8)) was significantly higher than that achieved with 45 mm partially threaded screws (0.6 kg/cm² (IQR 0.2 to 0.9)) (p = 0.04 and p < 0.001, respectively). The fully threaded screws and the 30mm partially threaded screws were seen to engage the physeal scar under an image intensifier in each case.

The results support the use of 30 mm partially threaded or 45 mm fully threaded screws that engage the physeal scar rather than longer partially threaded screws that do not. A 45 mm fully threaded screw may in practice offer additional benefit over 30 mm partially threaded screws in increasing the thread count in the denser paraphyseal region.

Cite this article: Bone Joint J 2013;95-B:1662–6.