gms | German Medical Science

Objectives: The early revision rate in elective Total Hip Arthroplasty (THA) three years after surgery in elderly patients over 80 years is significantly lower for cemented stems (3.1% [3.0–3.2] vs. uncemented stems (4.2% [4.1–4.3]; p<0.001) in the German Arthroplasty Register EPRD. However, the mortality rate in elderly patients has been reported to be elevated for cemented fixation [1]. This study presents a detailed analysis of the influence of stem fixation and stem type on revision and mortality rate in this patient cohort using a non inferiority approach.

Methods: Elective primary THA cases for primary Coxarthrosis using uncemented cups without reconstruction shells in patients over 80 years from the EPRD data base were included in the analysis without risk stratification(n0= 37,183; Table 1). Four stem type groups were compared: cementless (cyan in Figure 1 [Fig. 1]), cementless with collar (dark blue), cementless short (nude), and cemented (pink). Stems with at least 300 cases at risk three years after surgery (or with design and fixation variants) were analysed individually. The reference stemwas determined as the stem with the lowest revision rate and at least 1,000 cases under surveillance 3 years after surgery (n3=28,637) [2].

Results and conclusion: The revision rate for cemented stems (2.5% [2.2–1.81]; indicated by pink squares in Figure 1 [Fig. 1]) was sig. lower than for uncemented (4.5% [4.2–4.9]; cyan; p>0.001) and uncemented short stems (4.2% [3.1–5.7]; nude; p=0.002). The revision rate of uncemented collared stems (2.3% [1.5–3.6]; dark blue) was similar to cemented stems (p=0.89) and sig. lower than for uncemented stems (p=0.02). None of the individual stems was more than 20% inferior to the reference stem (Figure 1 [Fig. 1]).

One year mortality showed no sig. differences between the groups (p>0.17): cemented 3.2% [2.9–3.6], uncemented 3.4% [3.1–3.7], uncemented short 3.5% [2.5-4.9], uncemented collar 2.0% [1.2–3.2]; Table 1 [Tab. 1].

„Cementless“ and „cementless short“ stems should not be used in patients over 80 years due to the higher revision risk [3]. If cementing should be avoided, „cementless collared“ stems seem to be a good alternative combined with a tendency for a lower one year mortality rate.