Radial & Ulnar Lengthening / Shortening

1. Positive Ulnar Variance

Ulna longer than radius.
Idiopathic or post-traumatic (e.g., malunion).
Leads to: Ulnocarpal impaction, wrist pain,. 👉 Treatment: Ulnar shortening osteotomy (USO),.

2. Negative Ulnar Variance

Ulna shorter than radius.
Seen in: Growth disturbances and congenital conditions like Hereditary Multiple Exostoses (HME),.
Leads to progressive radial bowing and radial head dislocation in HME. 👉 Treatment: Ulnar lengthening,.

3. Radial Shortening

After distal radius malunion or trauma,.
Results in DRUJ instability. 👉 Options: Radial lengthening or ulnar shortening (more common),.

4. Congenital Deformities

5. Post-traumatic Deformity

Biomechanics (High-Yield)

Forearm function depends on length balance and DRUJ alignment; radius and ulna function as a mechanically coupled unit.
In neutral to slightly negative variance, 80% of axial load goes through the radiocarpal joint, and 20% through the ulnocarpal joint. 👉 Small changes (2–3 mm) significantly affect load distribution: Positive variance overloads the TFCC, lunate, and triquetrum.

1. Ulnar Shortening Osteotomy (USO)

Indications: Positive ulnar variance, ulnocarpal impaction, post-traumatic ulnar overgrowth,.
Techniques: Oblique osteotomy is strongly preferred over transverse for >4 mm shortening to increase contact area and stability,.
Fixation: Low-profile, pre-contoured compression plates with an integrated sliding mechanism.
Advantages: Predictable (75–96% excellent/good results) and technically straightforward,.

2. Radial Lengthening

Indications: Radial shortening deformity, severe malunion, Madelung deformity,.
Methods:
- Vickers ligament release + Dome osteotomy in skeletally immature patients (provides multiplanar correction without bone graft),.
- Gradual distraction using external fixator (Ilizarov) for severe deformities.
Limitations: Longer treatment time, higher complication rate.

3. Ulnar Lengthening

Indications: Negative ulnar variance, HME deformities,.
Technique:
- Gap <1.5 cm: Acute lengthening with bone graft.
- Gap >1.5 cm: Gradual distraction (Ilizarov/callotaxis) using an external fixator.
Rate: ~1 mm/day (0.25 mm, four times daily) to prevent neurovascular compromise,.

4. Combined Procedures

Radial osteotomy + ulnar shortening. Used simultaneously in complex deformities to restore radio-ulnar balance and DRUJ congruity. Bifocal osteosynthesis without graft is another alternative.

Preoperative Planning

Measure: Ulnar variance on standard AP wrist radiograph (shoulder 90° abducted, elbow 90° flexed, neutral rotation). Normal range is -2 mm to +2 mm.
Evaluate: DRUJ stability and soft tissue balance. 👉 Virtual Surgical Planning (VSP): 3D CT reconstruction and computer simulation are standard for complex multiplanar forearm osteotomies, improving angular accuracy,.

Postoperative Management

Complications

Nonunion (2–8% across techniques).
Hardware irritation: Most frequent minor complication. 30–50% require plate removal after USO,.
DRUJ osteoarthritis: 16–38% at 3 years post-USO, though mostly functional/asymptomatic remodelling,.
Pin site infection (lengthening).
Neurovascular injury,.

Prognosis

Pits & Pearls

Target ulnar variance is exactly 0 to −1 mm; do not overcorrect,.
Vickers ligament is present in 91% of Madelung cases; release is the foundational step regardless of age,.
HME (≤10 years): Ulnar lengthening alone is sufficient,.
Dome osteotomy provides simultaneous multiplanar correction without requiring a bone graft,.
3D VSP significantly improves angular accuracy over conventional planning,.

Pitfalls

Overcorrection in USO leading to high peak DRUJ pressures.
Failing to counsel the patient about hardware removal preoperatively (~30-50%),.
Assuming the radial head will reduce spontaneously during distraction in HME.
Poor fixation leading to nonunion.
Lengthening rate too fast (>1 mm/day) resulting in inadequate regenerate bone.

Mini Decision Algorithm

Condition	Decision	Action / Target
Idiopathic UIS / Positive variance	USO	Ulnar shortening osteotomy Target: 0 to −1 mm ulnar variance — oblique cut preferred
HME — age ≤ 10 years	Ulnar lengthening	Ulnar lengthening alone Sufficient remodelling potential — radial osteotomy not needed
HME — age > 10 years	Combined	Ulnar lengthening + radial corrective osteotomy Fixed angular deformity — remodelling alone insufficient
Madelung — skeletally immature	Radial correction	Vickers ligament release ± dome osteotomy Vickers ligament present in 91% — release is foundational step
Length discrepancy < 1.5 cm	Acute lengthening	Single-stage osteotomy + bone graft Faster treatment; neurovascular tolerance limit
Length discrepancy > 1.5 cm	Gradual distraction	Callotaxis — external fixator, ~1 mm/day No bone graft needed; allows multiplanar correction simultaneously
Complex multiplanar deformity	3D VSP	3D virtual surgical planning + combined osteotomy CT reconstruction + patient-specific guides; superior angular accuracy

References;

Peymani et al. Systematic review of Madelung deformity surgery (25 studies). J Hand Surg Am. 2019.
Carter PR, Ezaki M. Landmark series of 23 wrists demonstrating Vickers ligament in Madelung deformity cases.
Nishiwaki et al. Long-term outcomes of ulnar shortening osteotomy for idiopathic ulnar impaction syndrome. Clin Orthop Surg. 2011.
Mader et al. USO for UIS: 96% patients satisfied or cured. ScienceDirect. 2021.
Retrospective study of 19 Madelung deformity patients treated with Ilizarov technique. Front Pediatr. 2026.
Multiple exostoses ulnar lengthening studies supporting gradual ulnar lengthening as preferred approach for HME forearm deformity. PubMed Central; PMCID: PMC4837170, PMC6912751, PMC12644003.
Bauer et al. Computer-assisted vs conventional corrective forearm osteotomy. J Hand Surg Am. 2017.
Bifocal osteosynthesis for radial shortening deformity and DRUJ dislocation. PubMed Central; PMCID: PMC6787987.