A comprehensive system
of rectangular tapered stems
The restoration of an individual hip anatomy and biomechanics in a heterogeneous population is one of the main challenges that orthopaedic surgeons face today [1].
With the increasing number of THA in active and young patients, better performing implants are required [2].
By always keeping in mind patient care and well-being, Medacta has developed the P-Family Hip System to address these challenges,
helping surgeons to achieve surgical excellence.
The P-Family Hip System is a comprehensive system of cutting-edge rectangular triple-tapered stems featuring three distinct design options:
SMS, AMIStem-P and QUADRA-P.
P VALUES
While preserving the features important to the success of existing stem systems, the P-Family Hip System
was developed incorporating proven innovative key features.
P-stems are the evolution of successful and proven femoral stem concepts and are based on the remarkable legacy and clinical heritage of Quadra-H and AMIStem-H. Both stems demonstrate solid ODEP ratings[3,4] and survivorship data.
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100% survival rate for asepting loosening at 2 years.[10]
80% of cases performed through AMIS approach.
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All the three systems are characterized by a state-of-the-art MectaGrip proximal coating, which is a layer of commercially pure titanium plasma spray. Designed to enhance both initial and long-term stability, it allows for an improved load transfer [1,10]. Finally, a thin outer layer of hydroxyapatite (HA) is applied to the entire stem length, except for the polished distal tip of the SMS.
Professor William Walsh’s animal study demonstrates how a surface treated with MectaGrip coating can achieve a stronger bone-implant interface compared to a surface treated with hydroxyapatite only[10].
100% survival rate for any reasons at minimum 5 years.[9]
All cases performed through AMIS approach.
(F. Laude)
Anatomical Progressing
Head Center Growth
Literature has shown that the femoral offset should increase progressively with the stem size[12]. P-stems are characterized by an anatomically progressive head center growth, offering the surgeon an optimized tool to more efficiently restore the individual hip biomechanics in a wide patient population.
Double Offset Options
The vertical offset does not change when adding 5 mm of lateral offset for each size implant, therefore the leg length is not affected when changing from standard to lateralized.
By taking advantage of the P-Family Hip System, which is offered in varying shapes, canal filling dimensions, lengths, collared, collarless and cemented versions, the surgeon has the ability to select a stem that best matches each individual patient’s femoral morphology and bone quality, specifically addressing Type A, B and C femurs according to the DORR classification and thereby allowing for a more personalized THA[13].
The image above does not represent a differentiation of indications by the manufacturer. It is a representation prepared by one specific customer.
Available in collared and collarless versions, the P-Family Hip System features an extended size range to accommodate a large scale of patient anatomies. Small growth increments between sizes help ensure proper fit in the femur.
AMIStem-P and Quadra-P are also available in a cemented and short neck options.
COLLAR OPTION
The collar is designed to be positioned at a 1 mm distance from the medial calcar.
In this condition, load transfers through the triple taper body of the stem and the biomechanical behavior are identical to a collarless stem. In the case of implant subsidence, the collar comes in contact with the calcar bone, thus contributing to axial and rotational stability of the stem.
SHORT NECK OPTION
AMIStem-P and Quadra-P are also available in a short-neck version, allowing for better restoration of the biomechanics in small patient anatomies.
The short neck is 5 mm shorter with respect to standard neck.
Regular Neck
Regular Neck
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Regular Neck & Short Neck*
Regular Neck & Short Neck*
Regular Neck
Short Neck*
Regular Neck
Regular Neck
One single instrument platform is sufficient for each P-Family Hip System. Intuitive, simple and reproducible broach-only surgical technique, developed to maximize the operating room efficiency.
Several instrument configurations have been designed to be compatible with the THA approach preferred by each surgeon.
Both the implants instruments have been designed to reduce the risk of damaging the soft tissues when using the MIS techniques, especially the Anterior Minimally Invasive Surgery (AMIS) approach.
Regarding AMIStem-P and QUADRA-P, the surgeon has the possibility to switch from a press-fit to a cemented stem by using the same tray,
providing a high intra-op flexibility.
Tray
SMS
Collared - Collarless
AMIStem-P
Collared - Collarless - Cemented
Quadra-P
Collared - Collarless - Cemented
Instruments
Several broach handle options are available to accommodate modern surgical approaches.
The P-Family rasps ensure a precise preparation of the femoral canal, aiming for a stable and accurate positioning of the implant.
All P-stems can be used alongside any of the Medacta acetabular shells and liners
The P-Family Hip System represents the core of the Medacta Hip Implants portfolio. The Medacta offering embraces a Personalized Medicine Vision with a comprehensive platform for a personalized care experience with a Holistic Approach. Innovative implants, surgical technique and technologies bring value throughout the entire patient journey.
Dr. Frédéric Laude CMC Paris V, Paris, France
“This new coating for me is a game changer because the AMIStem was an easy stem to use for anterior approach and now it is still an easy stem, but it is a perfect stem for the long term. Now I have been using it for nearly 10 years and the results are just amazing. Patients are extremely happy.”
Tyler D. Goldberg - MD Texas Orthopedics, Austin, Texas
“My experience with the short femoral stems, in particular the SMS, has been increasing over the last several years. It has solved an indication that I needed greatly and that’s what to do with my patients with a Dorr A bone. The SMS works beautifully, so I use it in 100% of all my Dorr A patients and it works quite well.“
Prof. Richard Field London Elective Orthopaedic center, Epsom, UK
“I have been implanting variations of the SMS stem for 7 years and I have been really impressed by the way we get such good bony attachement proximally. The clinical results have been very satisfactory, we’ve recently introduced the collared variant of the stem, and this is giving me increasing confidence, that we may even be able to use it for Dorr B patients. The SMS is my go-to stem for the Dorr A femur.“
Dr. Loucks
Dr. Goldberg
Prof. Dr. med. Gollwitzer
[1] Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Hip, Knee & Shoulder Arthroplasty Annual Report 2022. https://aoanjrr.sahmri.com/annual-reports-2022. Figure HT2; Table and Figure HT17.
[2] AAOS American Joint Replacement Registry 2021 Annual Report. Table and Figure 2.2.
[3] Amistem Hap (2022) NEC ODEP. Available at: https://www.odep.org.uk/product/amistem-hap/ .
[4] Quadra H (2022) NEC ODEP. Available at: https://www.odep.org.uk/product/quadra-h/.
[5] P. Moreau. Cementless HA coated Quadra stem. 7-YEAR CLINICAL OUTCOMES. Data on file: Medacta.
[6] Kalberer F. “Retrospective and prospective study to evaluate the AMISTEM H performance”, study approved by Swiss Ethic (Zurich canton) on 24 of March 2016 (BASEC-Nr 2015-00132). Data on file: Medacta.
[7] Rahm S, Tondelli T, Steinmetz S, Schenk P, Dora C, Zingg PO. Uncemented Total Hip Arthroplasty Through the Direct Anterior Approach: Analysis of a Consecutive Series of 275 Hips With a Minimum Follow-Up of 10 Years. J Arthroplasty. 2019 Jun; 34(6):1132-1138.
[8] R. Field R, C. Dora, E. Crawfurd. AMIStem-H ODEP study results 7-Year Preliminary Clinical Outcomes. Data on file: Medacta.
[9] K. Bashti, E. Meyer, D. Hartmann, F. Tovagliaro, A. Nebunescu-Schirliu. 2-year Preliminary Clinical Outcome - Fr Multicentric Study. Data on file: Medacta.
[10] Walsh WR et al, Bone ongrowth and mechanical fixation of implants in cortical and cancellous bone. Journal of Orthopaedic Surgery and Research (2020) 15:177. https://josr-online.biomedcentral.com/track/pdf/10.1186/s13018-020-01696-5 Comparison of titanium coatings for cementless fixation in an ovine model – Medacta M.O.R.E. Journal White Papaer (October 2019) – Pr. Walsh study
[11] Viamont-Guerra, M.-R. et al. (2022) “Effect of femoral stem surface coating on clinical and radiographic outcomes of cementless primary total hip arthroplasty: A patient-matched retrospective study,” International Orthopaedics, 47(1), pp. 165–174. Available at: https://doi.org/10.1007/s00264-022-05629-1.
[12] J. Eijkenboom, P. Tomaszewski, D. Janssen, N. Verdonschot. Short Medacta Stem Pre-clinical assessment of bone remodeling and in growth potential - a finite element analysis.
[13] Patient matching femoral implants for tha – one stem type does not fit all (no date) MEDACTA TV. Available at: https://more.medacta.tv/videos/hip-video/patient-matching-femoral-implants-for-tha-one-stem-type-does-not-fit-all.
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