The peri-prosthetic tissue response to wear debris
is complex and influenced by various factors including the size, area
and number of particles. We hypothesised that the ‘biologically
active area’ of all metal wear particles may predict the type of
peri-prosthetic tissue response. Peri-prosthetic tissue was sampled from 21 patients undergoing
revision of a small diameter metal-on-metal (MoM) total hip arthroplasty
(THA) for aseptic loosening. An enzymatic protocol was used for
tissue digestion and scanning electron microscope was used to characterise
particles. Equivalent circle diameters and particle areas were calculated.
Histomorphometric analyses were performed on all tissue specimens.
Aspirates of synovial fluid were collected for analysis of the cytokine
profile analysis, and compared with a control group of patients
undergoing primary THA (n = 11) and revision of a failed ceramic-on-polyethylene
arthroplasty (n = 6). The overall distribution of the size and area of the particles
in both lymphocyte and
non-lymphocyte-dominated responses were similar; however, the subgroup
with lymphocyte-dominated peri-prosthetic tissue responses had a
significantly larger total number of particles. 14 cytokines (interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-10,
IL-13, IL-17, interferon (IFN)-γ, and IFN-gamma-inducible protein
10), chemokines (macrophage inflammatory protein (MIP)-1α and MIP-1ß),
and growth factors (granulocyte macrophage colony stimulating factor
(GM-CSF) and platelet derived growth factor) were detected at significantly higher
levels in patients with metal wear debris compared with the control
group. Significantly higher levels for IL-1ß, IL-5, IL-10 and GM-CSF
were found in the subgroup of tissues from failed MoM THAs with
a lymphocyte-dominated peri-prosthetic response compared with those
without this response. These results suggest that the ‘biologically active area’ predicts
the type of
peri-prosthetic tissue response. The cytokines IL-1ß, IL-5, IL-10,
and GM-CSF are associated with lymphocyte-dominated tissue responses
from failed small-diameter MoM THA. Cite this article:
In fall 2004 we started with minimal invasive hip surgery at our clinic. Our requirements: Use of our standard implant system (Bicon threaded cup and Zweymüller stem), fast realization of the minimal invasive procedure through the continuation of the used, anterolateral Watson-Jones approach, modified for this technique, retaining the supine position with unchanged orientation concerning the positioning of the implant parts. Our expectations: Reduction in operative trauma through lower blood loss with less post-operative pain, less limping especially during the first weeks, less trochanter pain through the preservation of the gluteal muscle tendons, fewer posterior dislocations by preservation of the dorsal capsule, and a better cosmetic result. The patient is placed in supine position on the standard OR table with the option of tilting the legs down. The contralateral leg lies on a leg holder in extended position, flexed by approx. 20 degrees. This allows to bring the leg in hyperextension (without hyperlordosis of the lumbar spine), adduction and external rotation during broaching the femur. The main criterion of the minimal invasivness is the preservation of the gluteal tendons and not primarily the reduction of the length of the skin incision. An extensive capsular release with partial dissection of the rectus tendon for exposure of the acetabulum is necessary. For the stem implantation a notching of the piriformis can be necessary in addition to this. During the stem preparation the soft tissues should not influence the axial entrance of the rasps into the femoral canal otherwise there is a danger of a dorsolateral perforation. Right-left-lateral-double-offset rasps and the use of manipulation rasps as trial prostheses have worked satisfactorily. Retrospective analyses of numerous peri- and post-operative data were accomplished, as well as radiological evaluations regarding the optimal position of the implanted joints, and compared with a conventional control group. After a learning curve the OP duration was the same in both groups. The development of the haemoglobin and hematocrit levels were identical, 1/3 of the patients needed blood subsitution (autologous or stored blood). 90% of the analysed postoperative x-rays in standing position showed equal bilateral leg length corresponding to the preoperative planning, the planned offset was achieved in 93%. Deviations of the remaining were without clinical relevance. The complication rate was 2,5%.
