Application of a shape-memory alloy internal fixator for treatment of acetabular fractures with a follow-up of two to nine years in China

Abstract

Displaced acetabular fractures should be treated surgically. Over the past decade, surgical approaches to the acetabulum and the surgical technique for repair of common fracture patterns have advanced. Excellent outcomes after repair of these injuries can be achieved. The aim of this study was to assess the medium-term results of reconstruction of acetabular fractures by using shape-memory alloy designed by the authors. This is a retrospective review conducted at a level 1 trauma centre. From October 1999 to July 2009, 19 patients with acetabular fractures were treated with our patented Ni-Ti shape-memory alloy acetabular tridimensional memory alloy-fixation system (ATMFS). The ATMFS device was cooled with ice before implantation and then warmed to 40-50°C after implantation to produce balanced axial and compression forces that would stabilise the fracture three dimensionally. Our results are as follows; according to the D'Aubigne-Postel scoring system: Fifteen cases out of 19 (79%) achieved excellent or good clinical results. In two patients, late complications included avascular necrosis of the femoral head (ANFH) associated with posterior dislocation of the hip joint two years after the operation. We also observed two cases of grade II or III ectopic ossification, with good hip function, and one case of traumatic arthritis. In conclusion, these results demonstrate the effectiveness of the ATMFS device for the management of acetabular fracture. The device provides continuous compression of the fracture with minimal disruption to the local blood supply.

Acetabular fractures in patients aged > 55 years

“…Initial assessment suggested that 61 studies might be relevant. These articles were reviewed independently by two orthopaedic surgeons (JSD and PSP) who both agreed that 16 [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] met the inclusion criteria. A further two studies 23,24 were identified on a secondary search of the bibliographies of the remaining articles.…”

“…In all, 12 studies included patients who were exclusively > 55 years, [8][9][10][11][13][14][15][16][17]20,23,24 and in a further three these data could be extracted. 12,18,19 Statistical analysis. Analysis of the data was performed using proportions and frequencies for categorical variables and means along with CIs and ranges for continuous variables.…”

Nickel-titanium shape-memory sawtooth-arm embracing fixator for periprosthetic femoral fractures

“…The soft tissue was isolated to an extent that allowed fracture reduction. Once the position of the Ni-Ti SSEF was ensured, it was warmed with hot saline (40−50°C) [11].…”

“…As the metal in the high-temperature (austenite) phase is cooled, the crystalline structure enters the low-temperature (martensite) phase, where it can be easily bent and shaped. As the metal is reheated, its original shape and stiffness are restored [9,11]. In addition to these desirable qualities, the material possesses excellent springback and superelastic properties [12].…”

Massive heterotopic ossification associated with late deficits in posterior wall of acetabulum after failed acetabular fracture operation

“…The graft was then placed in the acetabular wall defect and fixed temporarily with two K-wires. A new method called acetabular tridimensional memory alloy fixation system (ATMFS), which has been satisfactorily used for treatment of posterior wall fractures of the acetabulum, was used for internal fixation [6-8]. The procedure of planting ATMFS was exactly the same as described in the related literature [6,7].…”