Are LDFA (Lateral Distal Femoral Angle) measurements of 87 on the right and 89 on the left, and MPTA (Medial Proximal Tibial Angle) measurements of 83 on the right and 84 on the left, indicative of the need for a high tibial osteotomy (HTO) with bone grafting?

Assessment of Alignment Parameters for High Tibial Osteotomy

Based on your measurements (LDFA 87° right/89° left, MPTA 83° right/84° left), isolated high tibial osteotomy is NOT the appropriate surgical approach, and a double-level osteotomy (both femoral and tibial) would be required to achieve proper correction without creating excessive joint line obliquity or tibial overcorrection.

Deformity Analysis

Your angular measurements indicate a combined tibial and femoral deformity requiring careful surgical planning:

Tibial Component

• Right MPTA: 83° (normal 87-90°) 1, 2
• Left MPTA: 84° (normal 87-90°) 1, 2
• Both sides demonstrate significant tibial varus deformity (>3° deviation from normal) 1

Femoral Component

• Right LDFA: 87° (normal 85-90°) 1, 3
• Left LDFA: 89° (normal 85-90°) 1, 3
• The right side shows borderline femoral varus contribution 1

Surgical Recommendation

A double-level osteotomy is indicated for proper correction based on the following evidence:

• When both MPTA <85° and LDFA considerations exist, isolated HTO risks creating excessive tibial valgus (MPTA >95°) and joint line obliquity >5° 1, 3
• In a cohort analysis of 303 varus knees, 63% required double-level osteotomy when anatomic correction limits were respected (MPTA ≤90°, LDFA ≥85°) 1
• Even accepting overcorrection (MPTA ≤95°), 33% still required double-level osteotomy to avoid excessive joint line obliquity 1
• Your bilateral MPTA values of 83-84° place you in the category requiring double tibial osteotomy at minimum, potentially with femoral correction depending on overall mechanical axis 4

Critical Thresholds to Avoid Complications

Post-Operative MPTA Target

• Target post-operative MPTA: 95° to prevent recurrent varus deformity 2
• MPTA ≥95° resulted in 92.3% stable outcomes versus 47.4% with MPTA <95° 2
• However, MPTA should not exceed 95° to avoid excessive tibial valgus and joint line obliquity 1, 3

Joint Line Obliquity

• Maximum acceptable joint line obliquity: <5° 3
• Excessive obliquity complicates future total knee arthroplasty and affects functional outcomes 3

Bone Grafting Considerations

Autogenous bone graft is recommended for opening wedge osteotomies:

• Complete excision of deformity sites with sufficient autogenous bone graft represents consensus surgical management 5
• Opening wedge HTO without bone graft showed acceptable union rates, but your case requires double-level correction where graft stability becomes more critical 2
• Iliac crest bone graft (both cortical and cancellous) provides optimal structural support for double-level corrections 5

Surgical Approach Algorithm

For your specific measurements:

1. Bilateral double tibial osteotomy (proximal and distal tibial levels) to correct the bow-leg deformity throughout the tibia 4
2. Evaluate for concomitant distal femoral osteotomy if mechanical axis correction remains inadequate after tibial correction 1, 4
3. Target correction: Mechanical axis to 2° valgus, MPTA to 95°, maintaining joint line obliquity <5° 1, 2, 3
4. Fixation: External fixation combined with intramedullary fixation for stability 5

Common Pitfall to Avoid

The most critical error would be performing isolated HTO, which would require overcorrecting the MPTA to 95-100° to achieve proper mechanical axis alignment, creating:

• Excessive joint line obliquity (>5°) 3
• Increased risk of lateral compartment overload 1
• Complications for future total knee arthroplasty 3

The ESSKA consensus data demonstrates that only 25.3% of isolated HTOs met "ideal" indication criteria, with many creating unfavorable joint line geometry despite acceptable functional outcomes in the short term 3.