Benefit of 3-D Planning in Total Hip Replacement. A Prospective Randomized Study

Balgrist University Hospital

Status: Active, not recruiting

Conditions: Hip Injuries; Surgery; Prosthesis User

Treatments: Procedure: 2D planning of THR; Device: SPS monoblock stem, Symbios; Procedure: 3D planning of THR; Device: Quadra-H, Medacta

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT05120063

KEK Nr. 2012-0064

Details and patient eligibility

About

In this prospective randomized four-armed study the investigators aim to compare wheter 3-D planning, which necessitates preoperative CT acquisition and sophisticated planning together with engineers, results in measurable benefits in terms of objective and subjective outcome values in a collective of patients undergoing primary total hip replacement.

Hypothesis:

1. When compared to 2-D planning, 3-D planning of a THR results in better hip reconstruction, better subjective and clinical outcome and better longevity of total hip implants.
2. When compared to a non-anatomical stem, an anatomical stem allows better hip reconstruction, better subjective and clinical outcome and better longevity of total hip implants.

Full description

Patients sent to our outpatient clinic for eventual primary THR are informed about this study and written patient information given to them. When patients decide to undergo primary total hip replacement, patient's questions with respect to this study are discussed in the outpatient clinic and patients willing to participate included.

Block randomization using closed envelopes for age categories 40-50, 50-60, 60-70 years will be conducted to assign the participant to one of the four study arms.

Patients will be blinded for the type of stem and method of planning. Investigators are blined in terms of methods of planning. In terms of stem design, investigators can not be blinded since their visibility on x-ray does not allow it.

The preoperative investigation includes routine investigation and an additional CT scan plus evaluation of the "University of California at Los Angeles" (UCLA) activity level and "Short Form Health 36" (SF-36) score. The same applies for the postoperative investigation and 3 months. The follow-up visits at 1, 5 and 10 years are routine investigations with additional UCLA and SF-36 Scores.

Enrollment: 133 patients

Sex: All

Ages: 40 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• patients aged 40-70 years scheduled for primary THR
• signed written informed consent.

Exclusion criteria

• Charnley class B and C
• ASA score >2
• pregnancy
• gross hip deformity making complex hip reconstruction (greater trochanter advancement, acetabular augmentation, femoral osteotomy, use of cemented or revision stem) necessary
• immature patients and patients incompetent to judge

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

---

133 participants in 4 patient groups

3D anatomical stem

Experimental group

Description:

3-D-Planing with anatomical stem (SPS monoblock stem, Symbios)

Treatment:

Device: SPS monoblock stem, Symbios

Procedure: 3D planning of THR

3D non-anatomical stem

Experimental group

Description:

3-D-Planing with non anatomical stem (Quadra-H, Medacta)

Treatment:

Device: Quadra-H, Medacta

Procedure: 3D planning of THR

2D anatomical stem

Experimental group

Description:

2-D-Planing with anatomical stem (SPS monoblock stem, Symbios)

Treatment:

Procedure: 2D planning of THR

Device: SPS monoblock stem, Symbios

2D non anatomical stem

Experimental group

Description:

2-D-Planning with non anatomical Stem (Quadra-H, Medacta)

Treatment:

Device: Quadra-H, Medacta

Procedure: 2D planning of THR