Delayed dislocation following metal on polyethylene arthroplasty of the hip due to “silent” trunnion corrosion
- Lash,N.J.; Whitehouse,M.R.; Greidanus,N.V.; Garbuz,D.S.; Masri,B.A.; Duncan,C.P.
- The Bone and Joint Journal VOL. 98-B, No. 2, February 2016
- Level of Evidence:
- None given
Lash et al. presented a case series of 10 THAs with metal-on-polyethylene (MoP) bearings with delayed dislocations associated with unrecognized adverse tissue reactions due to corrosion at the trunnion and pseudotumor formation. Dislocation/instability and pain was the reason for revision in all cases. Pseudotumors were found in all cases, causing expansion and laxity of the posterior capsule. All metal (CoCrMo) heads were well fixed on the titanium trunnion and had to be forcibly removed. All tapers (male or female) showed a black ring of debris and corrosion products without evidence of impingement or PE wear. Eight hips were revised with a ceramic-on-polyethylene (CoP) bearing (BIOLOX®delta with sleeve, one without sleeve), the remaining 2 received MoP bearings. Six patients suffered further complications. There were 3 cases of PJI, 2 recurrent dislocations in patients with great damage to the abductor muscles, and 1 recurrence of pseudotumor (with MoP).
One of the key findings in this series was the “silent” nature of the taperosis, since there are no definitive symptoms pointing towards corrosion, which makes diagnosis difficult. If too much time passes until intervention, tissue damage can be extensive and revisions under these circumstances are associated with a high rate of complications, also when utilizing a ceramic ball head. However, for Lash et al. it is now routine practice to use a ceramic (BIOLOX®delta) femoral head with a titanium sleeve in patients with sensitivity to cobalt and/or chrome.
- Case series with only 10 THAs
- No investigation of metal levels within the tissue during revision
- Late dislocation in MoP bearings can occur due to extensive tissue damage because of ALTR due to corrosion.
- BIOLOX®delta femoral heads with a sleeve can successfully be used in patients with ALTR after MoP THA.