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High 10-year survival rate with an anatomic cementless stem (SPS).

Sariali E, Mouttet A, Mordasini P, Catonné Y - Clin. Orthop. Relat. Res. (2012)

Bottom Line: All stems appeared radiographically stable and one stem was graded nonintegrated but stable.Five patients had revision surgery: one on the femoral side (for posttraumatic fracture) and four on the acetabular side.Considering stem revision for aseptic loosening as the end point, survivorship was 100% (range, 95.4%-99.9%) at 10 years.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Hôpital Pitié Salpétrière, 47-83 Bd de l'Hôpital, 75013, Paris, France. hedisari@yahoo.fr

ABSTRACT

Background: Proximal cementless fixation using anatomic stems reportedly increases femoral fit and avoids stress-shielding. However, thigh pain was reported with the early stem designs. Therefore, a new anatomic cementless stem design was based on an average three-dimensional metaphyseal femoral shape. However, it is unclear whether this stem reduces the incidence of thigh pain.

Questions/purposes: We asked whether this stem design was associated with a low incidence of thigh pain and provided durable fixation and high function.

Methods: One hundred seventy-one patients (176 THAs) who had the anatomic proximal hydroxyapatite-coated stem implanted were reviewed. Eleven (6%) patients were lost to followup and 34 (20%) died without revision surgery. We used the Harris hip score (HHS) to assess pain and function. We evaluated femoral stem fixation and stability with the score of Engh et al. and also calculated a 10-year survival analysis. We assessed 126 patients (131 hips) at a mean followup of 10 years (range, 8-11 years)

Results: At last followup, two patients described slight thigh pain that did not limit their physical activities. All stems appeared radiographically stable and one stem was graded nonintegrated but stable. Five patients had revision surgery: one on the femoral side (for posttraumatic fracture) and four on the acetabular side. Considering stem revision for aseptic loosening as the end point, survivorship was 100% (range, 95.4%-99.9%) at 10 years.

Conclusion: This anatomic cementless design using only metaphyseal fixation with a wide mediolateral flare, a sagittal curvature, and torsion, allowed durable proximal stem stability and fixation.

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Related in: MedlinePlus

The SPS stem was designed to achieve intimate contact with the proximal femur. Fifteen degrees of anterior torsion of the upper portion of the stem was used to fit the natural femoral helitorsion. The axial cuts A, B, and C show the progressive helitorsion of the stem and the femur. The bicondylar plane of the knee (BCP) is used as a reference for the torsion. The stem design includes a wide mediolateral flare (42°) which permits a horizontal neck osteotomy (30°) and therefore bone preservation.
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Fig1: The SPS stem was designed to achieve intimate contact with the proximal femur. Fifteen degrees of anterior torsion of the upper portion of the stem was used to fit the natural femoral helitorsion. The axial cuts A, B, and C show the progressive helitorsion of the stem and the femur. The bicondylar plane of the knee (BCP) is used as a reference for the torsion. The stem design includes a wide mediolateral flare (42°) which permits a horizontal neck osteotomy (30°) and therefore bone preservation.

Mentions: Based on the experience of making custom prostheses [13], a cementless anatomic stem was designed using a computer-assisted technique to achieve intimate contact between the stem and the anatomic shape of the proximal femur. The design was based on a database of 300 hip CT images to approximate an average intracanalar shape of the proximal femoral metaphysis and obtain reference values for torsion of the proximal femur in the axial and sagittal planes [23]. The stem was designed with an anterior torsion of 15° and an anterior sagittal curvature to fit the average proximal femur (Fig. 1), presuming this shape would ensure good primary stability and long-term fixation. In an earlier study [28], a 5-year overall survival rate of 98.8% was reported for 171 patients (176 hips). To confirm those findings, we now report on the same cohort at longer followup.Fig. 1


High 10-year survival rate with an anatomic cementless stem (SPS).

Sariali E, Mouttet A, Mordasini P, Catonné Y - Clin. Orthop. Relat. Res. (2012)

The SPS stem was designed to achieve intimate contact with the proximal femur. Fifteen degrees of anterior torsion of the upper portion of the stem was used to fit the natural femoral helitorsion. The axial cuts A, B, and C show the progressive helitorsion of the stem and the femur. The bicondylar plane of the knee (BCP) is used as a reference for the torsion. The stem design includes a wide mediolateral flare (42°) which permits a horizontal neck osteotomy (30°) and therefore bone preservation.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369068&req=5

Fig1: The SPS stem was designed to achieve intimate contact with the proximal femur. Fifteen degrees of anterior torsion of the upper portion of the stem was used to fit the natural femoral helitorsion. The axial cuts A, B, and C show the progressive helitorsion of the stem and the femur. The bicondylar plane of the knee (BCP) is used as a reference for the torsion. The stem design includes a wide mediolateral flare (42°) which permits a horizontal neck osteotomy (30°) and therefore bone preservation.
Mentions: Based on the experience of making custom prostheses [13], a cementless anatomic stem was designed using a computer-assisted technique to achieve intimate contact between the stem and the anatomic shape of the proximal femur. The design was based on a database of 300 hip CT images to approximate an average intracanalar shape of the proximal femoral metaphysis and obtain reference values for torsion of the proximal femur in the axial and sagittal planes [23]. The stem was designed with an anterior torsion of 15° and an anterior sagittal curvature to fit the average proximal femur (Fig. 1), presuming this shape would ensure good primary stability and long-term fixation. In an earlier study [28], a 5-year overall survival rate of 98.8% was reported for 171 patients (176 hips). To confirm those findings, we now report on the same cohort at longer followup.Fig. 1

Bottom Line: All stems appeared radiographically stable and one stem was graded nonintegrated but stable.Five patients had revision surgery: one on the femoral side (for posttraumatic fracture) and four on the acetabular side.Considering stem revision for aseptic loosening as the end point, survivorship was 100% (range, 95.4%-99.9%) at 10 years.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Hôpital Pitié Salpétrière, 47-83 Bd de l'Hôpital, 75013, Paris, France. hedisari@yahoo.fr

ABSTRACT

Background: Proximal cementless fixation using anatomic stems reportedly increases femoral fit and avoids stress-shielding. However, thigh pain was reported with the early stem designs. Therefore, a new anatomic cementless stem design was based on an average three-dimensional metaphyseal femoral shape. However, it is unclear whether this stem reduces the incidence of thigh pain.

Questions/purposes: We asked whether this stem design was associated with a low incidence of thigh pain and provided durable fixation and high function.

Methods: One hundred seventy-one patients (176 THAs) who had the anatomic proximal hydroxyapatite-coated stem implanted were reviewed. Eleven (6%) patients were lost to followup and 34 (20%) died without revision surgery. We used the Harris hip score (HHS) to assess pain and function. We evaluated femoral stem fixation and stability with the score of Engh et al. and also calculated a 10-year survival analysis. We assessed 126 patients (131 hips) at a mean followup of 10 years (range, 8-11 years)

Results: At last followup, two patients described slight thigh pain that did not limit their physical activities. All stems appeared radiographically stable and one stem was graded nonintegrated but stable. Five patients had revision surgery: one on the femoral side (for posttraumatic fracture) and four on the acetabular side. Considering stem revision for aseptic loosening as the end point, survivorship was 100% (range, 95.4%-99.9%) at 10 years.

Conclusion: This anatomic cementless design using only metaphyseal fixation with a wide mediolateral flare, a sagittal curvature, and torsion, allowed durable proximal stem stability and fixation.

Show MeSH
Related in: MedlinePlus