Is a tibial shaft osteotomy (TSO) recommended for patients with tibial vara undergoing total knee replacement (TKR)?

Tibial Shaft Osteotomy in TKR for Tibial Vara

Tibial shaft osteotomy should NOT be routinely performed during total knee replacement for tibial vara, as standard TKR techniques with appropriate bone cuts and component positioning can adequately address most varus deformities without the need for diaphyseal osteotomy.

Clinical Context and Decision Framework

The question conflates two distinct surgical scenarios that require clarification:

Pre-TKR Osteotomy (Joint-Preserving Strategy)

• Realignment osteotomy (high tibial osteotomy) is an option in active patients with symptomatic unicompartmental OA and malalignment as an alternative to or temporizing measure before TKR 1
• This represents a joint-preserving procedure performed INSTEAD of TKR, not during it 2, 3
• The AAOS provides moderate evidence (Grade C) that realignment osteotomy and unicompartmental knee arthroplasty show no difference in outcomes and complications for medial compartment OA 1
• High tibial osteotomy provides survivorship of 74.7-97.6% at 10 years and 66.0-90.4% at 15 years 3

Intraoperative Tibial Tubercle Osteotomy During TKR

• Tibial tubercle osteotomy during TKR carries a 23% major complication rate related to surgical technique and an additional 8% unrelated to technique 4
• This procedure is reserved for severe exposure difficulties, not for addressing tibial vara deformity 4
• Rheumatoid arthritis and previous knee surgery are predisposing factors for complications 4

Why Diaphyseal Osteotomy Is Not Indicated During TKR

Standard TKR bone cuts at the metaphyseal level correct varus alignment without requiring shaft-level osteotomy:

• TKR component positioning addresses alignment through proximal tibial and distal femoral cuts, not through diaphyseal correction 1
• The AAOS provides strong evidence supporting cemented or non-cemented tibial component fixation with standard techniques 1
• Tibial stems should be avoided in primary TKR when bone quality is adequate and anatomy is normal 5

Critical Distinction: Origin of Deformity Matters

Recent evidence demonstrates that the anatomic origin of varus deformity (femoral vs. tibial) significantly impacts surgical decision-making:

• Patients undergoing HTO without true tibial vara deformity (medial proximal tibial angle >85°) have higher risk of clinical deterioration at mid-term follow-up 6
• Conversely, UKA patients WITH tibial vara deformity also show increased risk of not maintaining clinical improvements 6
• This suggests that matching the surgical correction to the anatomic source of deformity is crucial 6

When Extra-Articular Deformity Requires Special Consideration

If severe extra-articular tibial deformity exists (>15-20° of diaphyseal bowing), this represents a rare scenario requiring:

• Staged correction with metaphyseal osteotomy performed separately from TKR, allowing healing before arthroplasty
• Referral to a surgeon with expertise in complex deformity correction 1
• Recognition that attempting simultaneous diaphyseal osteotomy and TKR dramatically increases complication risk 4

Practical Algorithm

For patients with tibial vara presenting for knee arthroplasty:

1. Measure the mechanical axis and identify deformity location (metaphyseal vs. diaphyseal) 6
2. If deformity is primarily metaphyseal (most common): Proceed with standard TKR using appropriate bone cuts 1
3. If patient is young (<60), active, with isolated medial compartment OA: Consider HTO as joint-preserving alternative 1, 2
4. If severe extra-articular tibial deformity exists: Stage procedures—correct shaft deformity first, then perform TKR after healing 1
5. Never perform tibial shaft osteotomy simultaneously with TKR due to unacceptably high complication rates 4

Common Pitfalls to Avoid

• Do not confuse pre-TKR realignment osteotomy (a joint-preserving alternative) with intraoperative shaft osteotomy during TKR 1, 2
• Avoid tibial tubercle osteotomy during TKR unless absolutely necessary for exposure, given 23% major complication rate 4
• Do not use long tibial stems (>100mm) in primary TKA unless dealing with extensive bone defects 5
• Recognize that inadequate tibial slope affects patellar tracking and can lead to instability, which accounts for 7.5% of revision cases 7
• Ensure proper postoperative alignment, as suboptimal correction increases risk of clinical deterioration regardless of procedure type 6