30 Sep Short-stem vs. standard-stem: Clinically equivalent, biomechanically superior
Short-stem vs. standard-stem: Clinically equivalent, biomechanically superior
In recent years, short-stem hip arthroplasty has evolved from a niche solution into an established component of standard hip replacement practice. This year marks the 10th anniversary of the A2® short stem. For us at ARTIQO, this serves as a welcome opportunity to take a closer look at the scientific evidence and the current state of biomechanical knowledge. What exactly distinguishes a short stem from a standard stem in biomechanical terms, and how robust is the clinical evidence, really? Here is an overview.
Registry data: continuous growth in the use of short stems
According to the German Arthroplasty Registry (EPRD), the share of short stems among primary, cementless hip replacements has risen from approximately 5 percent (in 2014) to 23.3 percent, as noted in the most recent annual report.[1] However, during this year’s anniversary symposium, PD Dr. Thomas Randau (Cologne) pointed out that the EPRD’s definition of a “short stem” has not been applied with complete consistency over the years. The classification is based primarily on the length of the stem rather than the underlying anchoring principle. Furthermore, the adoption rate varies significantly between individual clinics—ranging from 0 percent to, in some isolated cases, 100 percent. Dr. Randau also noted that, according to the registry data, a “moderately good” short stem can sometimes show better failure rates than a high-quality standard stem.
PD Dr. Thomas Randau, Köln
In doing so, he refers to the clear differences in outcomes between the various stem systems. In the 2025 EPRD annual report, short stems once again performed better than standard stems: cementless short stems showed an average failure probability of 3.3% within 8 years, compared to 4.3% for standard stems over the same period. The cementless A2® short stem demonstrated a very low failure probability of 3.1% within eight years.[1]
The biomechanical advantages are very well documented scientifically
It is well established in current literature that the biomechanical behavior of calcar-guided short stems differs from that of standard stems. A systematic review and meta-analysis of randomized controlled trials confirms that short stems offer advantages over standard stems in terms of bone preservation, primary stability, and reduced stress shielding.[2] At the clinical level, this finding is supported by a prospective dual-energy X-ray absorptiometry (DEXA) study: Lerch et al. (2012) demonstrated—using the Metha® short stem in patients—a significantly smaller decrease in periprosthetic bone density than is typically observed with standard stems; this serves as direct evidence of a more physiological, proximal load transfer.[3] Finite element and cadaver studies consistently confirm this strain pattern, even when compared directly with standard stems that feature metaphyseal fixation.[4],[5],[6]
Mario Frank, who is responsible for product development at ARTIQO, explains the biomechanical differences between short stems and standard stems: “Calcar-guided short stems, such as the A2® short stem, achieve fixation in the proximal femur through an extensive medial bearing surface combined with lateral support. In contrast, conventional straight stems typically rely on a meta-diaphyseal tapered fixation, which primarily transmits compressive forces to the distal region.” In vitro and finite element analyses have demonstrated that calcar-guided short stems facilitate a more physiological, proximal load transfer with reduced bending forces. These biomechanical principles have been documented not only in laboratory experiments but also in clinical practice.[3]
Mario Frank
The difference becomes clinically relevant, in particular, regarding trochanteric fractures: In a retrospective propensity-score-matched analysis of 3,053 hip arthroplasties, Luger et al. (2023) found a significantly lower rate of periprosthetic fractures within the first year for short-stem implants (1.7% vs. 3.2%; p = 0.015)—specifically concerning Vancouver type A fractures in the trochanteric region (p = 0.002)—whereas no difference was observed for type B fractures (p = 0.563).[7]
Another advantage concerns the reconstruction of the femoral and anterior offset, as well as the individual CCD (caput-collum-diaphyseal) angle: Because calcar-guided short stems are not constrained by a rigid axial anchoring trajectory, they can—unlike long, straight stems, which are prone to causing antecurvation—align more closely with the patient’s unique anatomy. This flexibility is discussed, for instance, by Stauss et al. (2026)—using a classification system for femoral morphotypes developed in Oldenburg—and by Traina et al. (2009) in the context of gender-related differences in hip morphology.[8],[9] Cadaver studies and a randomized controlled trial further confirm this advantage regarding the reconstruction of the center of rotation and the anterior offset when compared to standard stems.[10],[11],[12]
### Clinical Equivalence to Standard Stems
The biomechanical advantages of calcar-guided short stems—bone preservation, reduced stress shielding, and more physiological load transmission—are thus considered to be very well supported by scientific evidence. But what about the clinical evidence? In addition to the previously mentioned, highly favorable real-world clinical data from the EPRD, a ten-year follow-up from a randomized controlled trial (van Beers et al., 2024) shows no significant difference in implant survival between short-stem and standard-stem implants.[13] Furthermore, a recent meta-analysis of randomized trials (Zhang et al., 2021) confirms that, overall, short-stem implants are clinically equivalent to standard-stem implants.[14]
Based on data from the EPRD, Steinbrück et al. (2021) compared 17,526 short-stem implantations with an equal number of standard-stem implantations, matched for age, sex, hospital volume, and bearing couple. The overall revision rate after 5 years did not differ significantly (2.9% vs. 3.1%; p = 0.08). However, the infection rate was significantly lower for the short-stem implants (0.7% vs. 1.0%; p = 0.005).[15]
Consequently, current evidence supports calcar-guided short-stem implants—such as the A2® short stem—as a well-founded biomechanical option. They are clinically on par with standard implants while offering compelling advantages in terms of bone preservation, fracture risk, infection risk, and the reconstruction of individual anatomy.
Quellen
[1] Deutsches Endoprothesenregister (EPRD). Jahresbericht 2025.
[2] Liang HD et al. Are short-stem prostheses superior to conventional stem prostheses in primary total hip arthroplasty? A systematic review and meta-analysis of randomised controlled trials. BMJ Open. 2018;8(9):e021649.
[3] Lerch M et al. Bone remodelling around the Metha short stem in total hip arthroplasty: a prospective dual-energy X-ray absorptiometry study. Int Orthop. 2012;36(3):533–538.
[4] Yan SG et al. Metaphyseal anchoring short stem hip arthroplasty provides a more physiological load transfer: a comparative finite element analysis study. J Orthop Surg Res. 2020;15:498.
[5] Floerkemeier T et al. A short stem with metaphyseal anchorage reveals a more physiological strain pattern compared to a standard stem – an experimental study in cadavaric bone. Acta Bioeng Biomech. 2019;21(2):153–159.
[6] Freitag T et al. Biomechanics of a calcar loading and a shortened tapered femoral stem: comparative in-vitro testing of primary stability and strain distribution. J Exp Orthop. 2021;8:74.
[7] Luger M et al. Periprosthetic femoral fractures in cementless short versus straight stem total hip arthroplasty: a propensity score matched analysis. J Arthroplasty. 2023;38(4):751–756.
[8] Stauss R et al. Definition of femoral morphotypes based on the coronal plane alignment of the hip classification. J Arthroplasty. 2026 (Epub ahead of print).
[9] Traina F et al. Sex differences in hip morphology: is stem modularity effective for total hip replacement? J Bone Joint Surg Am. 2009;91(Suppl 6):121–128.
[10] Ezechieli M et al. A neck-preserving short stem better reconstructs the centre of rotation than straight stems: a computed tomography-based cadaver study. Arch Orthop Trauma Surg. 2022;142(7):1669–1680.
[11] Budde S et al. Hip joint function and reconstruction of the anterior femoral offset in patients with short stem vs. conventional THA. Sci Rep. 2023;13(1):2387.
[12] Imiolczyk J et al. Precision of Femoral Reconstruction in Short-Stem versus Conventional-Stem Total Hip Arthroplasty: A Randomized Clinical Trial Comparing Two Implant Philosophies. Abstract, 16th Congress of the European Hip Society, Thessaloniki, 2025.
[13] van Beers LWAH et al. Short versus conventional straight stem in uncemented total hip arthroplasty: functional outcomes up to 5 years and survival up to 12 years: secondary results of a randomized controlled trial. Acta Orthop. 2024;95:99–107.
[14] Zhang Z, Xing Q, Li J, et al. A comparison of short-stem prostheses and conventional stem prostheses in primary total hip arthroplasty: a systematic review and meta-analysis of randomized controlled trials. Ann Transl Med. 2021;9(3):231.
[15] Steinbrück A et al. Short versus conventional stem in cementless total hip arthroplasty: an evidence-based approach with registry data of mid-term survival. Orthopäde. 2021;50(4):296–305.
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