Varus Stem Positioning of a Cementless Anatomical THA. (VARABG) (VARABG)

Varus Stem Positioning Does Not Affect Long-term Functional Outcome in Cementless Anatomical Total Hip Arthroplasty.

Varus positioning is the most common femoral malposition in total hip arthroplasty (THA). The aim of this study was to compare the long-term results of an anatomical cementless femoral stem positioned in varus with those in neutral alignment.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis; Arthroplasty Complications
• Intervention / Treatment: Diagnostic test: Xray

Detailed Description

Data were prospectively collected and retrospectively reviewed for all patients who received a cementless anatomical femoral stem in THA between 1998 and 2008. After exclusion criteria applied, 127 stems had an varus axis deviated by more than 3 degrees (varus group) and 156 had an alignment between 0 and 2.9° from the femoral axis (neutral group). Survivorship rates, complications, clinical scores, thigh pain, radiological score, cortical hypertrophy and filling rate were analyzed. Mean follow-up was 10 years.

• Study Type: Observational
• Enrollment (Actual): 283

Contacts and Locations

Study Locations

• France
  • Gard
    • Nîmes, Gard, France, 30900
      • CHU Nîmes

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The investigators identified all patients who underwent proximal HA-coated anatomic tapered femoral stem primary THAs between October 1998 and July 2008, through our institutional total joint registry. The data were prospectively collected on the Orthowave© database. This included patients who had an uncemented ABG-2 stem (Stryker, Mahwah, NJ). The study was a test-case retrospective analysis and an institutional review board approval was obtained prior to initiation of the study.

Description

Inclusion Criteria:

• All patients received by several senior surgeons, the same standardized posterolateral total hip arthroplasty, and the same rehabilitation protocol.

Exclusion Criteria:

• Etiologies other than osteoarthritis (osteonecrosis, fracture, dysplasia, rheumatoïd arthritis),
• Complex cases with additional procedure,
• Dual-taper modular or cemented stem,
• Incomplete preoperative data or less than one-year postoperative data.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Varus group; Radiographic stem axis was assessed on standard anteroposterior hip radiographs performed at the 3-month follow-up visit. Alignment was evaluated as described by Reina et al., by the angular deviation of the anatomic femoral axis and the stem axis. The 3 degrees minimal-value was considered to be the threshold defining a varus stem.	Diagnostic test: Xray; Hip AP Xray
Neutral group; Alignment between anatomic femoral axis ans stem axis was less than 3°.	Diagnostic test: Xray; Hip AP Xray

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Long-term survival of THA with varus or neutral cementless fixation of a proximal HA-coated anatomic tapered femoral stem.	Kaplan-Meier survivorships free of revision of the femoral component for any reason, femoral fracture and revision of femoral component for fracture were calculated and compared by log-rank test for both group.	Survival evaluation was carried out through study completion at an average of 10 years by the surgeon.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Long-term clinical outcomes with varus or neutral femoral stem.	Clinical status was assessed by the Harris hip score (HHS).	Clinical evaluation was carried out through study completion at an average of 10 years by the surgeon.
Long-term radiological outcomes with varus or neutral femoral stem.	Radiological assessment was conducted at the last follow-up in charge antero-posterior and profile X-Ray.	Radiological evaluation was carried out through study completion at an average of 10 years by the surgeon.

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Nīmes

Publications and helpful links

General Publications

• Reina N, Salib CG, Perry KI, Hanssen AD, Berry DJ, Abdel MP. Mild Coronal Stem Malalignment Does Not Negatively Impact Survivorship or Clinical Results in Uncemented Primary Total Hip Arthroplasties With Dual-Tapered Implants. J Arthroplasty. 2019 Jun;34(6):1127-1131. doi: 10.1016/j.arth.2019.01.055. Epub 2019 Jan 31.
• Khalily C, Lester DK. Results of a tapered cementless femoral stem implanted in varus. J Arthroplasty. 2002 Jun;17(4):463-6. doi: 10.1054/arth.2002.32171.
• Min BW, Song KS, Bae KC, Cho CH, Kang CH, Kim SY. The effect of stem alignment on results of total hip arthroplasty with a cementless tapered-wedge femoral component. J Arthroplasty. 2008 Apr;23(3):418-23. doi: 10.1016/j.arth.2007.04.002. Epub 2007 Nov 9.

Study record dates

Study Major Dates

• Study Start (ACTUAL): January 1, 2018
• Primary Completion (ACTUAL): May 1, 2018
• Study Completion (ACTUAL): November 5, 2020

Study Registration Dates

• First Submitted: November 13, 2020
• First Submitted That Met QC Criteria: November 26, 2020
• First Posted (ACTUAL): December 4, 2020

Study Record Updates

• Last Update Posted (ACTUAL): December 4, 2020
• Last Update Submitted That Met QC Criteria: November 26, 2020
• Last Verified: November 1, 2020

More Information

Terms related to this study

• Keywords: survivorship; Total hip arthroplasty; varus alignment; anatomical stem
• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis
• Other Study ID Numbers: 20.0035

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No