Radiological Comparison Between Single-Leg and Double-Leg Stance in the Assessment of Genu Varum: Pre- and Postoperative Evaluation and Functional Outcomes

Genu varum, commonly known as bow-legged deformity, is characterized by an outward angulation of the knee joint that disrupts normal lower limb alignment and weight distribution(1,2). This condition alters the mechanical axis of the limb, often increasing medial compartment loading, which can accelerate degenerative joint changes and pain. Radiographic assessment plays a central role in quantifying the deformity, typically measured through parameters such as the hip-knee-ankle (HKA) angle, mechanical axis deviation (MAD), and medial proximal tibial angle (MPTA)(1,2).

Weight-bearing posture during imaging significantly influences these alignment parameters. Several studies have demonstrated that single-leg stance radiographs produce more physiologically representative alignment measurements than double-leg stance, since the single-leg condition better simulates natural load distribution and joint reaction forces during locomotion(3,4). The single-leg stance increases joint compression and reveals hidden malalignments that may be masked in double-leg or non-weight-bearing positions. Consequently, preoperative evaluations based solely on double-leg stance may underestimate the severity of genu varum deformity(3,4).

Surgical correction, through techniques such as high tibial osteotomy or guided growth, aims to restore the mechanical axis to a near-neutral position, improving load symmetry and delaying degenerative changes(4,5). Postoperative evaluation is essential for monitoring realignment success and predicting functional recovery, which often involves comparing radiological correction with clinical outcomes such as range of motion, pain reduction, and activity resumption. However, the correspondence between radiographic correction measured under different stance conditions and postoperative function remains poorly defined(6,7).

Recent evidence suggests that patients assessed preoperatively under single-leg stance conditions may have more accurate predictions of postoperative alignment and function than those evaluated under double-leg stance (5,6). Furthermore, differences between stance types may influence surgical planning decisions, including the degree of correction targeted and the fixation technique used. Functional outcomes after genu varum correction depend not only on bony realignment but also on balanced muscular forces, proprioception, and joint stability - factors more dynamically engaged in single-leg stance evaluation(7,8).

Despite increasing recognition of weight-bearing differences in radiological evaluation, limited research directly compares single-leg versus double-leg stance assessment for genu varum across preoperative and postoperative stages. Establishing which stance provides a more reliable correlation with functional outcomes could refine surgical planning, enhance rehabilitation monitoring, and standardize postoperative evaluation protocols for improved patient outcomes.

Study Overview

• Status: Not yet recruiting
• Conditions: Genu Varum

• Study Type: Observational
• Enrollment (Estimated): 70

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients with genu varum

Description

Inclusion Criteria:

• • Patients aged 18-65 years diagnosed with genu varum requiring surgical correction (e.g., high tibial osteotomy )

  • Willingness to participate and provide informed consent.
  • Ability to stand independently for radiographic assessment.
  • No prior lower limb surgery within the last year.

Exclusion Criteria:

• Patients with genu varum with Blount's disease, rickets and metabolic bone disease.

  • History of knee surgery within the last year.
  • Neurological, psychological, or systemic disorders affecting gait or stance.
  • Inadequate preoperative or follow-up radiographs.
  • Inability to comply with follow-up schedule.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Group A; single-leg stance group
Group B; double-leg stance group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
radiographic alignment parameters	Difference in radiographic alignment parameters between single-leg and double-leg stance pre- and postoperatively.	3 months postoperative

Collaborators and Investigators

• Sponsor: Assiut University

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: May 5, 2026
• First Submitted That Met QC Criteria: July 18, 2026
• First Posted (Actual): July 22, 2026

Study Record Updates

• Last Update Posted (Actual): July 22, 2026
• Last Update Submitted That Met QC Criteria: July 18, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Genu Varum
• Other Study ID Numbers: RadiologicalSingle Double leg

Drug and device information, study documents

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