SMF^◊ Short Monolithic Femoral

SMF^◊ Product Information

The Short Monolithic Femoral System (SMF) is a total primary hip system consisting of proximally porous coated titanium alloy (Ti-6Al-4V) tapered femoral hip stems with optimized and easy to use instrumentation. It offers the surgeon an improved bone conserving modular neck implant that is compatible with high demand femoral head bearing options from Smith & Nephew.

Features Include:

• Strength
• Stability
• Versatility

The SMF hip stem is shorter than conventional hip stems, which allows the stem to conserve more of the patient's femur than other prostheses. The SMF hip stem allows for a slightly higher neck resection. The proximal porous coating of the stem consists of STIKTITE^◊ Porous Coating, a commercially pure Titanium coating, and is designed to have a press-fit relative to the broach of approximately 1/4mm. The stems are proportionally sized and shaped in sizes -1 through 6, with optional larger sizes 7 through 9. The stems are compatible with four modular neck options that create seven distinct neck positions to address patient anatomy. The SMF system provides modular necks which are manufactured from Cobalt Chrome alloy (CoCr) and are available in standard and high offset plus left and right anteverted options. With various head options from Smith & Nephew, the modular necks allow adjustment of the head center to as many as 42 distinct head center locations.

SMF^◊ Design and Technology

• Strength
• Stability
• Versatility

The SMF Short Monolithic Femoral Hip System was designed to provide predictable early implant stability with the benefits of bone conservation and neck modularity that provides 42 head center options with only 4 necks. This allows all of your femoral heads to be used with minimal increased inventory.

• 11 stems
• 9 modular and 2 monolithic
• Short stem length (73-101mm)
• Proximal neck resections
• Modular necks
• Proximal coating with STIKTITE^◊
• 42 Head Centers

Strength

A CoCr modular neck provides for a strong neck construct. Fatigue testing has shown that the SMF Cobalt Chrome modular neck design exceeds the fatigue strength of the same neck design made out of titanium alloy by as much as 83% and a conventional titanium monolithic hip stem by as much as 18%. ¹

Stability

Utilizing radiosterometric analysis (RSA), the SMF system demonstrated stability consistent with the clinically successful SYNERGY^◊ primary hip stem. Moreover, HHS and WOMAC scores indicated excellent relative clinical outcomes for the SMF group.² With one of the highest coefficients of friction in the industry³, a porosity of 60% and an average pore size which is ideal for boney ingrowth⁴, STIKTITE^◊ coating provides a solid foundation for both initial and long term fixation.


42 distinct head center
Each dot represents a head center that is achievable with the SMF system and the vast compliment of Smith & Nephew femoral heads.

Conservation

The SMF system offers surgeons an improved bone sparing modular neck implant. Additionally, the SMF stem design allows for a higher neck resection which conserves more of the patient's femur than conventional stems. Saving more bone during a primary hip arthroplasty means a wider range of options for the future.

References

1. Aldinger P, Tsai S, and Bergin A. CoCr and Ti-6Al-4V Modular Neck Fatigue Testing, Poster no. 479 presented at the Society for Biomaterials 2009 Annual Meeting and Exposition, April 22-25, 2009, San Antonio, TX.
2. Bone&JointScience Vol 01. No 02. Dec 2010 RSA analysis of early migration of the uncemented SMF vs SYNERGY stem: A prospective randomized controlled trial RW McCalden1, DN Naudie1, A Thompson1, CA Moore2
3. Heiner AD, Brown TD. Frictional coefficients of a new bone ingrowth structure, Poster no. 1623 presented at Orthopaedic Research Society Annual Meeting, Feb. 11-14, 2007, San Diego, CA.
4. Kienapfel H, Sprey C, Wilke A, and Griss. Implant fixation by bone ingrowth, J Arthroplasty, 14(3):355-68, 1999.

SMF^◊ Indications

The SMF stem components are indicated for uncemented use in individuals undergoing primary and revision surgery where other treatments or devices have failed in rehabilitating hips damaged as a result of trauma, inflammatory joint disease such as rheumatoid arthritis, or noninflammatory degenerative joint disease (NIDJD) or any of its composite diagnoses such as:

• Osteoarthritis
• Avascular necrosis
• Traumatic arthritis
• Slipped capital epiphysis
• Fused hip
• Fracture of the pelvis
• Diastrophic variant

Inflammatory

• Nonunion, femoral neck fracture and trochanteric fractures of the proximal femur with head involvement that are unmanageable using other techniques;
• Femoral osteotomy, or Girdlestone resection
• Fracture dislocation of the hip
• Correction of deformity