Non-modular tapered fluted, titanium stems are
available for use in femoral revision. The combination of taper
and flutes on the stem provides axial and rotational stability,
respectively. The material and surface properties of the stem promotes
bone on-growth. If the surgeon is confident and reasonably experienced
in the surgical use of this sort of design and the case is relatively
straightforward, a non-modular design is effective. It also potentially reduces
implant inventory, and circumvents the potential problems of taper
junction corrosion and fatigue fracture. There are reports of excellent
survival, good clinical and functional results and evidence of subsequent
increase in proximal bone stock. Cite this article: Bo
We present the clinical and radiographic outcome of 68 consecutive primary total hip replacements performed in 54 patients under the age of 55 years using a hydroxyapatite-coated femoral component and threaded cup with a modular ceramic head (JRI-Furlong). We reviewed 62 (91%) hips at a median follow-up of 8.8 years (5 to 13.8) after implantation; six (9%) were lost to follow-up. At review there had been four (6%) revisions but only one for aseptic loosening (acetabulum). Radiographic review of the remaining hips did not identify any evidence of femoral or acetabular loosening. The median Harris and Merle d’Aubigné and Postel hip scores were 95.9 (42.7 to 100) and 17 (3 to 18) respectively. The JRI-Furlong hip gives promising functional and radiographic results in young patients in the medium term.
Revision after failed femoral components may
be technically demanding due to loss of peri-prosthetic bone. This retrospective
study evaluated the long-term results of femoral revision using
the cementless Wagner Self-Locking stem. Between 1992 and 1998,
68 consecutive hips in 66 patients underwent femoral revision using
this implant. A total of 25 patients died from unrelated causes
without further revision; the remaining 41 hips in 41 patients (12 men
and 29 women) with a mean age of 61 years (29 to 80) were reviewed
at a mean follow-up of 13.9 years (10.4 to 15.8). A transfemoral
approach was used in 32 hips. A total of five stems required further
revision because of infection in two, progressive subsidence in
two and recurrent dislocation in one. Four hips had dislocated and
eight stems had subsided ≥ 10 mm. The mean Harris hip score improved
from 33 points pre-operatively to 75 points at final follow-up (p
<
0.001). In all, 33 stems (91.7%) showed radiological signs
of stable bone fixation. The cumulative survival rates at 15.8 years
with femoral revision for any reason and for stem failure as the
endpoints were 92.0% (95% confidence interval (CI) 86.0% to 98.4%)
and 96.6% (95% CI 92.2% to 100%), respectively. The survivorship
with revision and ≥ 10 mm migration of the stem as the endpoint
was 83.6% (95% CI 76.6% to 91.4%). This study shows quite good survival and moderate clinical outcome
when using a monoblock tapered titanium stem for supporting the
regeneration of bone in complex revision hip surgery.
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.
Polished, tapered stems are now widely used for cemented total hip replacement and many such designs have been introduced. However, a change in stem geometry may have a profound influence on stability. Stems with a wide, rectangular proximal section may be more stable than those which are narrower proximally. We examined the influence of proximal geometry on stability by comparing the two-year migration of the Exeter stem with a more recent design, the CPS-Plus, which has a wider shoulder and a more rectangular cross-section. The hypothesis was that these design features would increase rotational stability. Both stems subsided approximately 1 mm relative to the femur during the first two years after implantation. The Exeter stem was found to rotate into valgus (mean 0.2°,
Primary uncemented femoral stems reported to the Norwegian arthroplasty register between 1987 and 2005 were included in this prospective observational study. There were 11 516 hips (9679 patients) and 14 different designs of stem. Kaplan-Meier survival probabilities and Cox regression were used to analyse the data. With aseptic loosening as the end-point, all currently used designs performed excellently with survival of 96% to 100% at ten years. With the end-point as stem revision for any cause, the long-term results of the different designs varied from poor to excellent, with survival at 15 years ranging between 29% and 97%. Follow-up for longer than seven years was needed to identify some of the poorly-performing designs. There were differences between the stems; the Corail, used in 5456 hips, was the most frequently used stem with a survival of 97% at 15 years. Male gender was associated with an increased risk of revision of × 1.3 (95% confidence interval 1.05 to 1.52), but age and diagnosis had no influence on the results. Overall, modern uncemented femoral stems performed well. Moderate differences in survival between well-performing stems should be interpreted with caution since the differences may be caused by factors other than the stem itself.