This is a retrospective case series of 138 hips undergoing isolated head and liner exchange in revision THA. Every hip used a large femoral head (≥32 mm) with crosslinked polyethylene, and most used offset or lipped liners. The question: do modern large heads and liners lower the high dislocation rate seen in older exchange series?
When you offer isolated head and liner exchange, the old fear is instability, since exchange series with 28 mm heads reported dislocation as high as 25%. This series shows that using a head ≥32 mm in every hip, with offset or lipped liners in 75%, drops that rate to about 3%. Larger heads increase jump distance and head-to-neck ratio, which resists dislocation.
But the results depend on case selection, not just implant choice. The exchange only works when components are well-fixed and well-positioned with an intact abductor mechanism and a usable cup locking mechanism. Hips with malposition or abductor deficiency were sent for cup revision or dual mobility instead.
Remember the trade-off: infection, not dislocation, became the leading complication, mostly in hips exchanged for acute infection. When you do a DAIR-plus-exchange for acute PJI, expect roughly 85-90% success and counsel accordingly.
This is a retrospective case series of 138 hips undergoing isolated head and liner exchange in revision THA. Every hip used a large femoral head (≥32 mm) with crosslinked polyethylene, and most used offset or lipped liners. The question: do modern large heads and liners lower the high dislocation rate seen in older exchange series?
When you offer isolated head and liner exchange, the old fear is instability, since exchange series with 28 mm heads reported dislocation as high as 25%. This series shows that using a head ≥32 mm in every hip, with offset or lipped liners in 75%, drops that rate to about 3%. Larger heads increase jump distance and head-to-neck ratio, which resists dislocation.
But the results depend on case selection, not just implant choice. The exchange only works when components are well-fixed and well-positioned with an intact abductor mechanism and a usable cup locking mechanism. Hips with malposition or abductor deficiency were sent for cup revision or dual mobility instead.
Remember the trade-off: infection, not dislocation, became the leading complication, mostly in hips exchanged for acute infection. When you do a DAIR-plus-exchange for acute PJI, expect roughly 85-90% success and counsel accordingly.