The Trabecular Metal Monoblock acetabular component in patients with high congenital hip dislocation

Abstract

Between November 1997 and December 2000 we performed 27 total hip replacements in 22 patients with high congenital dislocation of the hip using porous tantalum monoblock acetabular components implanted in the true acetabular bed. Clinical and radiological evaluation was performed at regular intervals for a mean of 10.2 years (8.5 to 12). The mean Harris Hip Score improved from 48.3 (15 to 65) pre-operatively to 89.5 (56 to 100) at the final follow-up. The mean Oxford Hip Score was 49.5 (35 to 59) pre-operatively and decreased to 21.2 (12 to 48) at one year and 15.2 (10 to 28) at final follow-up. Migration of the acetabular component was assessed with the EBRA software system. There was a mean migration of 0.68 mm (0.49 to 0.8) in the first year and a mean 0.89 mm (0.6 to 0.98) in the second year, after excluding one initial excessive migration. No revision was necessary for any reason, no acetabular component became loose, and no radiolucent lines were observed at the final follow-up. The porous tantalum monoblock acetabular component is an implant offering adequate initial stability in conjunction with a modulus of elasticity and porosity close to that of cancellous bone. It favours bone ingrowth, leading to good mid-term results.

Trochanteric osteotomy in total hip replacement for congenital hip disease

“…In those with high dislocation, trochanteric osteotomy was performed in combination with shortening of the femur by progressive resection of the femoral neck. We argue against preserving the greater trochanter and shortening of the femur by a subtrochanteric, diaphyseal or distal osteotomy, [11][12][13][14][15][16][17] because in most cases of high dislocation the greater trochanter is more cranial than the centre of rotation of the femoral head, and its resection and advancement is essential. 18,19 Also, the creation of an artificial intraoperative fracture of the femur may cause undesirable complications.…”

Additively manufactured porous tantalum implants

“…It has proven bone ingrowth both in animal studies [29,[43][44][45] and retrievals from clinical cases [46,47], 5 although some publications mention issues like implant failure and the brittle deformation behavior of TM [48][49][50]. Furthermore, the mechanical properties of TM are close to those of human bone [51][52][53][54] and most uses of TM can be found in hip [55][56][57][58][59][60][61][62], knee [63][64][65][66][67], spinal [40,[68][69][70] and other orthopedic applications [71]. Despite the clinical success of TM, no other implant manufacturers use Ta as raw material for orthopedic implants.…”

Trabecular metal tibia still stable at 5 years

“…High proportions of bone ingrowth and sufficient biological fixation have been shown experimentally in animal studies (Bobyn et al 1999b, Bullens et al 2010) and in a retrieved human specimen (D’Angelo et al 2008). Excellent long-term clinical results of uncemented TM acetabular cups have been reported (Macheras et al 2009, 2010). Short- and medium-term clinical results of TM tibial components are encouraging (Helm et al 2009, Unger et al 2011).…”