Epsilon™ Durasul® Constrained Insert

Stability without compromise
The Problem: Dislocation is the second most common major complication in THA, occurring after 0.4 - 7% of primary THAs and up to 19% of revision THAs.1,3,4,7 Dislocation can be physically destructive, leading to abductor tissue damage. Reoperation results in stability in only 69% of cases.2
Constrained inserts are designed to reduce the incidence of dislocation. However, the design of traditional constrained inserts severely restricts ROM, leading to impingement. This may lead to component failure,8,5 dislocation,6,7 and implant loosening.8

The Solution:  Epsilon Durasul Constrained Insert  

  • Manufactured from Durasul® Highly Crosslinked Polyethylene, an advanced bearing surface that resists wear and aging.11
  • Head diameters up to 38mm to increase ROM.10
  • Compatible with Converge® CSTi Porous Acetabular System, built on 15 years of clinical success.12
  • Retaining fingers capture thehead.
  • Cut-outs increase ROM.  

Constraining Functionality Retained
In lever-out testing, the Epsilon Durasul Constrained Insert performed as well as the two most commonly used constrained inserts.13 

ROM Increased over Traditional Constrained Insert
In testing using a saw-bones set-up and a three-dimensional goniometer, the Epsilon Durasul Constrained Insert demonstrated much-improved ROM when compared with a traditional con-strained insert.14 

Cut-outs increase ROM where it is needed most
In a study of 111 retrieved acetabular components, researchers identified two primary sites of impingement damage.9 One site occurred where the neck impinged during full flexion or flexion plus internal rotation (anterior-superior). The second site occurred where the neck impinged during external rotation in extension (posterior-inferior).
Based on these findings, the Epsilon Durasul Constrained Insert was designed with cut-outs that may be placed where impingement is most likely to occur.
For a left hip, the smaller, superior retaining finger is placed at one o’clock to optimize ROM.

Sources Cited

  1. Paterno SA, Lachiewicz PF, Kelley SS. The influence of patient-related factors and positionof the acetabular component on the rate of dislocation after total hip replacement. JBJS (Am). 1997; 79(8):1202-10.
  2. Woo RY, Morrey BF. Dislocations after total hip arthroplasty JBJS. 1982; 64-A(9):1295-1306.
  3. Callaghan JJ, Heithoff BE, Boetz DD, Sullivan PM, Pederson DR, Johnston RC. Preventionof dislocation after hip arthroplasty. Clin Orthop. 2001; 393:157-62.
  4. Etienne A, Cupic Z, Charnley J. Postoperative dislocation after Charnley low-friction arthroplasty. Clin Orthop. 1978; 132:19-23.
  5. Kaper BP, Bernini PM. Failure of a constrained acetabular prosthesis of a total hip arthroplasty. A report of four cases. JBJS (Am). 1998, Apr; 80(4):561-5.
  6. Anderson MJ, Murray WR, Skinner HB. Constrained acetabular components. J Arthroplasty. 1994, Feb; 9(1):17-23.
  7. Lombardi AV Jr, Mallory TH, Karus TJ, Vaughn BK. Preliminary report on the S-ROM constraining acetabular insert: a retrospective clinical experience. Orthop. 1991, Mar; 14(3):297-303.
  8. Fisher DA, Kiley K. Constrained acetabular cup disassembly. J Arthroplasty. 1994, Jun; 9(3):325-9.
  9. Yamaguchi M, Akisue T, Bauer TW, Hashimoto Y. The spatial location of impingement in total hip arthroplasty. J Arthroplasty. 2000, Apr; 15(3):305-13.
  10. Muratoglu OK, Bragdon CR, O’Connor D, Perinchief RS, Estok DM, Jasty M, Harris WH. Larger diameter femoral heads used in conjunction with a highly cross-linked ultra-high molecular weight polyethylene. J Arthroplasty. 2001; 16(8), Suppl 1:24-30.
  11. Muratoglu OK, Bragdon CR, O’Connor DO, Harris WH. A novel method of cross-linking ultra-high-molecular-weight polyethylene to improve wear, reduce oxidation, and retain mechanical properties. J Arthroplasty. 2001; 16(2):149-60.
  12. Udomkiat P, Dorr LD, Wan Z. Cementless hemispherical porous-coated sockets implanted with press-fit technique without screws: Average ten-year follow-up. JBJS (Am). 2002; 84(7):1195-1200.
  13. Testing conducted by the Orthopedic Biomechanics and Biomaterials Lab at Massachusetts General Hospital, Boston, Massachusetts.
Acetabular

Vorige pagina