What is the Wullstein classification of ossiculoplasty (ossicular reconstruction)?

Wullstein Classification of Ossiculoplasty

The Wullstein classification of ossiculoplasty consists of five types (I-V) of tympanoplasty procedures based on the remaining middle ear structures and the method of sound transmission reconstruction.

Classification Overview

Type I (Myringoplasty)

• Definition: Repair of tympanic membrane only with intact ossicular chain
• Indication: Tympanic membrane perforation with normal ossicular chain
• Technique: Grafting of the tympanic membrane without ossicular manipulation
• Hearing outcome: Excellent prognosis with air-bone gap closure typically within 10 dB

Type II

• Definition: Repair of tympanic membrane with erosion of malleus head or incus
• Indication: Partial ossicular chain defect with intact stapes and malleus handle
• Technique: Grafting of tympanic membrane and connecting the malleus handle to the stapes head
• Hearing outcome: Good prognosis with typical air-bone gap closure within 20 dB

Type III (Columella Effect)

• Definition: Tympanic membrane grafted directly onto stapes head
• Indication: Absent incus and malleus with intact stapes superstructure
• Technique: Creating a columella between the tympanic membrane and stapes head
• Hearing outcome: Moderate prognosis with typical air-bone gap of 15-25 dB

Type IV

• Definition: Tympanic membrane grafted to protect round window, sound transmitted directly to oval window
• Indication: Absent incus, malleus, and stapes superstructure with mobile footplate
• Technique: Creating an air pocket around the round window while exposing the oval window
• Hearing outcome: Fair prognosis with typical air-bone gap of 25-40 dB

Type V

• Definition: Creation of a fenestration in the lateral semicircular canal
• Indication: Fixed stapes footplate with non-functional oval window
• Technique: Creating an alternative sound pathway through the lateral semicircular canal
• Hearing outcome: Poor prognosis with significant conductive hearing loss

Prognostic Factors

Several factors influence the success of ossiculoplasty:

1. Ossicular status: Presence of stapes superstructure is the most significant positive prognostic factor 1
2. Malleus handle presence: When present, significantly improves hearing outcomes (11.6±6.2 dB vs 16.9±10.1 dB when absent) 2
3. Middle ear mucosal condition: Mucosal fibrosis and drainage negatively impact hearing results 2
4. Type of reconstruction material: Autologous materials (ossicle or cortical bone) maintain their integrity for over 25 years 3
5. Surgical technique: The use of tragal cartilage for tympanic membrane reconstruction is associated with better hearing outcomes 1

Surgical Considerations

• Prosthesis selection: The ideal prosthesis should be biocompatible, stable, safe, and capable of optimal sound transmission 3
• Autologous vs. alloplastic materials: Autologous materials remain the preferred choice due to their long-term stability, though alloplastic materials are gaining popularity 3
• Silastic banding technique: When the stapes is intact but the malleus is absent, stabilizing the total ossicular replacement prosthesis with Silastic banding can achieve air-bone gap closure within 10 dB in 61.5% of cases 4

Success Rates

• Overall success rates (defined as air-bone gap ≤20 dB) range from 61-77% depending on the ossicular status 5
• In the absence of incus, success rates of 74.2% can be achieved 5
• When the stapes is absent, success rates decrease to 63.3% 5
• In the absence of the malleus, 85% of patients can achieve an air-bone gap ≤20 dB with proper reconstruction techniques 5

The Wullstein classification remains a fundamental framework for understanding ossicular reconstruction options based on the remaining middle ear structures, guiding surgeons in selecting the appropriate reconstruction technique to optimize hearing outcomes.