Computer hexapod assisted orthopaedic surgery (CHAOS), is a method
to achieve the intra-operative correction of long bone deformities
using a hexapod external fixator before definitive internal fixation
with minimally invasive stabilisation techniques. The aims of this study were to determine the reliability of this
method in a consecutive case series of patients undergoing femoral
deformity correction, with a minimum six-month follow-up, to assess
the complications and to define the ideal group of patients for
whom this treatment is appropriate. The medical records and radiographs of all patients who underwent
CHAOS for femoral deformity at our institution between 2005 and
2011 were retrospectively reviewed. Records were available for all
55 consecutive procedures undertaken in 49 patients with a mean
age of 35.6 years (10.9 to 75.3) at the time of surgery.Aims
Patients and Methods
We describe 24 fractures of the tuberosity of the calcaneus in 22 patients. Three were similar to the type of avulsion fracture which has been well-defined but the remainder represent a group which has been unrecognised previously. Using CT and operative findings we have defined the different patterns of fracture of the calcaneal tuberosity. Ten fractures extended into the subtalar joint, but did not fit the pattern of the common intra-articular fracture as described classically. We have defined a new pattern which consists of a fracture of the medial calcaneal process with a further fracture which separates the upper part of the tuberosity in the semicoronal plane. Non-operative treatment of displaced fractures resulted in a mis-shapen heel and a poor functional outcome. Open reduction and internal fixation with either a plate or compression screw did not give satisfactory fixation. We prefer to use an oblique lateral tension-band wire. This technique gave excellent fixation and we recommend it for the treatment of displaced fractures of the tuberosity of the calcaneus.
