The removal of well-fixed bone cement from the femoral canal during revision of a total hip replacement (THR) can be difficult and risks the loss of excessive bone stock and perforation or fracture of the femoral shaft. Retaining the cement mantle is attractive, yet the technique of cement-in-cement revision is not widely practised. We have used this procedure at our hospital since 1989. The stems were removed to gain a better exposure for acetabular revision, to alter version or leg length, or for component incompatibility.

We studied 136 hips in 134 patients and followed them up for a mean of eight years (5 to 15). A further revision was required in 35 hips (25.7%), for acetabular loosening in 26 (19.1%), sepsis in four, instability in three, femoral fracture in one and stem fracture in one. No femoral stem needed to be re-revised for aseptic loosening.

A cement-in-cement revision of the femoral stem is a reliable technique in the medium term. It also reduces the risk of perforation or fracture of the femoral shaft.

A series of 100 consecutive osteoarthritic patients was randomised to undergo total knee replacement using a Miller-Galante II prosthesis, with or without a cemented polyethylene patellar component. Knee function was evaluated using the American Knee Society score, Western Ontario and McMaster University Osteoarthritis index, specific patellofemoral-related questions and radiographic evaluation until the fourth post-operative year, then via questionnaire until ten years post-operatively. A ten-point difference in the American Knee Society score between the two groups was considered a significant change in knee performance, with α and β levels of 0.05.

The mean age of the patients in the resurfaced group was 71 years (53 to 88) and in the non-resurfaced group was 73 years (54 to 86).

After ten years 22 patients had died, seven were suffering from dementia, three declined further participation and ten were lost to follow-up. Two patients in the non-resurfaced group subsequently had their patellae resurfaced. In the resurfaced group one patient had an arthroscopic lateral release. There was no significant difference between the two treatment groups: both had a similar deterioration of scores with time, and no further patellofemoral complications were observed in either group.

We are unable to recommend routine patellar resurfacing in osteoarthritic patients undergoing total knee replacement on the basis of our findings.

Retention of well fixed bone cement at the time of a revision THA is an attractive proposition, as its removal can be difficult, time consuming and may result in extensive bone stock loss or fracture. Previously reported poor results of cemented revision THA, however, have tended to discourage Surgeons from performing ‘cement in cement’ revisions, and this technique is not in widespread use.

Since 1989 in Exeter, we have performed a ‘cement within cement’ femoral stem revision on 354 occasions. An Exeter polished tapered stem has been cemented into the existing cement mantle on each occasion.

Clinical and radiological follow up of 5 years or longer is available for 156 cases. On no occasion has a cement in cement femoral stem had to be re-revised during this time for subsequent aseptic loosening.

This has encouraged the refinement of this technique, including the development of a new short stem designed specifically for cement within cement revisions. This stem is designed to fit into an existing well fixed cement mantle of most designs of cemented femoral components or hemi-arthroplasties, with only limited preparation of the proximal mantle required. The new stem greatly simplifies cement in cement revision and minimises the risk of distal shaft perforation or fracture, which is otherwise a potential hazard when reaming out distal cement to accommodate a longer prosthesis.