ZWEYMUELLER SL FEMORAL HIP STEM

K962101 · Intermedics Orthopedics · LZO · Aug 19, 1996 · Orthopedic

Device Facts

• Record ID: K962101
• Device Name: ZWEYMUELLER SL FEMORAL HIP STEM
• Applicant: Intermedics Orthopedics
• Product Code: LZO · Orthopedic
• Decision Date: Aug 19, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 888.3353
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

The Zweymueller SL Femoral Hip Stem is intended to replace the anatomy of the femur in cases of total hip replacement. In addition, the Zweymueller SL Femoral Hip Stem is intended to be intraoperatively assembled to the commercially available Sulzer Orthopedics Limited (SOL) or Intermedics Orthopedics, Inc. (IOI) femoral bearing heads. The general indications associated with the use of Zweymueller SL 2. Fracture or avascular necrosis. 3. Conditions consequent to earlier operations such as joint reconstruction (Osteotomy), arthrodesis, hemi-arthroplasty, or total hip replacement (THP), total knee replacement, as well as operations on shoulder and elbow joints, and spinal surgery.

Device Story

Zweymueller SL Femoral Hip Stem is a titanium alloy, conical, straight femoral hip prosthesis with a rectangular cross-section for rotational stability. Designed for cemented or cementless total hip arthroplasty; features grit-blasted surface for bone/cement interdigitation; includes proximal extraction hole and lateral holes for cerclage wire fixation; distal tip is pyramidal and rounded. Device is intraoperatively assembled with Sulzer 12/14 configured femoral heads (e.g., Biolox ceramic). Used by orthopedic surgeons in clinical settings to replace femoral anatomy. Benefits include reduced stress via widened proximal geometry and enhanced fixation. This is a line extension of the predicate Zweymueller-SL Hip Prosthesis, adding sizes 01 and 0 and providing the device sterile.

Clinical Evidence

No clinical data provided. Substantial equivalence is based on design identity to the predicate device.

Technological Characteristics

Material: Titanium alloy. Design: Conical straight stem, rectangular cross-section, pyramidal distal tip. Fixation: Grit-blasted surface for cemented or cementless application. Connectivity: None. Sterilization: Provided sterile. Sizes: 01, 0, 1-12.

Indications for Use

Indicated for patients requiring total hip replacement due to fracture, avascular necrosis, or conditions resulting from prior orthopedic surgeries including joint reconstruction, arthrodesis, hemi-arthroplasty, total hip/knee replacement, or spinal surgery.

Regulatory Classification

Identification

A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.

Predicate Devices

• Zweymueller-SL Hip Prosthesis (K871453)
• SL-Plus (K930963)

Reference Devices

• Biolox ceramic heads (K892644)

Submission Summary (Full Text)

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AUG 10 1996
K962101

# 510(k) Premarket Notification
## Summary of Safety and Effectiveness
### for
### Zweymueller SL Femoral Hip Stem

In accordance with the Food and Drug Administration Interim Rule to implement provisions of the Safe Medical Devices Act of 1990 and in conformance with 21CFR 807, this is to serve as a 510(k) Summary for the Zweymueller SL Femoral Hip Stem.

**Submitter:**
Intermedics Orthopedics, Inc. (IOI)
9900 Spectrum Drive
Austin, Texas, 78717
Tel.: [phone]
Fax: [phone]

**Contact Person:**
*Regarding this submission:*
Name: Sam Mirza
Tel.: [phone]
Fax: [phone]

*Official Correspondent*
Name: Jacquelyn Hughes
Tel.: [phone]
Fax.: [phone]

**Date:**
May 24, 1996

**Proprietary name**
Zweymueller SL Femoral Hip Stem

**Common Name:**
Hip Prosthesis

**Classification name:**
Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis (21CFR 888.3353).

**Predicate Devices:**
The features employed by the Zweymueller SL Femoral Hip Stem are substantially equivalent to the features employed by the following predicate legally marketed devices:

Zweymueller-SL Hip Prosthesis, Sulzer Orthopedics Limited; and
SL-Plus; Plus Endoprothetik.

**Device Description:**
The Zweymueller SL Femoral Hip Stem employs a Sulzer 12/14 configured trunnion for attachment to femoral heads, including Biolox ceramic heads, featuring a Sulzer 12/14 configured bore. The Biolox heads have been determined substantially equivalent by the FDA via

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510(k) number K892644. The Biolox ceramic heads are available in two sizes (28mm and 32mm outer diameters (OD)).

The Zweymueller SL Femoral Hip Stem is a line extension of an existing legally marketed SOL's Zweymueller-SL Hip Prosthesis which has previously been determined substantially equivalent by the FDA via 510(k) #K871453. The Zweymueller SL Femoral Hip Stem is identical in design to the predicate Zweymueller-SL Hip Prosthesis except for the following:

* The Zweymueller SL Femoral Hip Stem is provided sterile; and
* The Zweymueller SL Femoral Hip Stem is available in sizes 01 and 0 in addition to sizes 1 through 12.

The Zweymueller SL Femoral Hip Stem is designed as a conical straight stem with a rectangular cross section to ensure rotational stability. The proximal portion of the hip stem employs an extraction hole to facilitate removal of the stem in revision cases. The widened proximal geometry of the Zweymueller SL Femoral Hip Stem reduces stresses due to compressive and torsional forces by allowing forces to be transmitted over a larger area (Stress = Force/Area). The proximal/lateral portion of the hip stem employs four holes for optional use with a cerclage wire to provide enhanced fixation of the hip stem to the greater trochanter.

The entire stem below the neck of the hip stem is grit blasted to provide enhanced fixation in both cemented and cementless total hip arthroplasties. In a cemented application, the grit blasted surface provides greater cement interdigitation with bone cement. In a press-fit or cementless application, the grit blasted surfaces provide an enhanced bone/prosthesis interface.

The distal tip of the Zweymueller SL Femoral Hip Stem is of pyramidal shape and is rounded off at the transition to the shaft. This facilitates transmission of load to the distal cortical bone.

## Intended Use:

The Zweymueller SL Femoral Hip Stem is intended to replace the anatomy of the femur in cases of total hip replacement. In addition, the Zweymueller SL Femoral Hip Stem is intended to be intraoperatively assembled to the commercially available Sulzer Orthopedics Limited (SOL) or Intermedics Orthopedics, Inc. (IOI) femoral bearing heads.

The general indications associated with the use of Zweymueller SL

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2. Fracture or avascular necrosis.
3. Conditions consequent to earlier operations such as joint reconstruction (Osteotomy), arthrodesis, hemi-arthroplasty, or total hip replacement (THP), total knee replacement, as well as operations on shoulder and elbow joints, and spinal surgery.

## Summary of Technological Characteristics:

A side by side tabular comparison of the characteristics of the Zweymueller SL Femoral Hip Stem to those of the currently marketed IOI and competitive devices follows:

| Characteristics | Subject Device
Zweymueller SL Femoral Hip Stem | Predicate Devices | |
| --- | --- | --- | --- |
| | | Zweymueller-SL Hip Prosthesis | SL-Plus |
| Manufacturer | Sulzer Orthopedics Limited | Sulzer Orthopedics Limited | Plus Endoprothetik. |
| 510(k) No. | - | K871453 | K930963 |
| Application | Cementless | Cementless | Cementless |
| Material | Titanium Alloy | Titanium Alloy | Unknown to IOI |
| Rectangular cross-section | Yes | Yes | Yes |
| Holes on the lateral side | Yes | Yes | Yes |
| Pyramidal shaped distal tip | Yes | Yes | Yes |
| Sizes | 01, 0, and 1 - 12 | 1 - 12 | Unknown to IOI |