Anterior transoral atlantoaxial release and posterior instrumented fusion for irreducible congenital basilar invagination.
OBJECTIVE
Recently, it has been demonstrated that anterior release of tight structures via a transoral approach can assist posterior distraction-reduction technique in restoring the cranio-cervical anatomy in irreducible atlantoaxial dislocations. Our aim was to evaluate the radiological and clinical outcome of anterior release and posterior instrumentation for irreducible congenital basilar invagination.


METHODS
A consecutive series of 15 patients (2007-2009) with irreducible congenital basilar invagination were treated with anterior release using transoral approach. A retrospective chart review was performed. All patients presented with myelopathy. Dislocation was treated as irreducible if acceptable reduction was not achieved with traction under general anesthesia and neuromuscular paralysis. The anterior release comprised of transverse sectioning the longus colli and capitis, C1-C2 joint capsular release and intra-articular adhesiolysis with or without anterior C1 arch excision. Cantilever mechanism using posterior instrumentation was used to correct any residual malalignment.


RESULTS
Mean age was 21.4 (10-50) years. Average duration of follow-up was 28 (24-40) months. The average preoperative JOA score was 11.4 (8-16), which improved to 15.4 (10-18) after surgery. Anatomical reduction was achieved in thirteen patients. Fusion was documented in all patients. Complications included persistent nasal phonation in one, and superficial wound dehiscence in one.


CONCLUSIONS
We believe that a significant number of irreducible dislocations can be anatomically reduced with this procedure thus avoiding odontoid excision. Encouraging results from this short series have given us a new perspective in dealing with these challenging problems.
Department of Orthopaedics, King Edward VII Memorial Hospital, Mumbai, India.
Vinod
V
Laheri
Department of Orthopaedics, King Edward VII Memorial Hospital, Mumbai, India. chaudhary.kc@gmail.com.|, 206-3A, Vaishali Nagar, KK Marg, Sat Rasta, Mahalaxmi East, Mumbai, 400011, India. chaudhary.kc@gmail.com.
Kshitij
K
Chaudhary
Department of Orthopaedics, King Edward VII Memorial Hospital, Mumbai, India.
Ashok
A
Rathod
Department of Spine Surgery, Kokilaben Dhirubhai Ambani Hospital, Mumbai, India.
Mihir
M
Bapat
D000293:Adolescent; D000328:Adult; D001268:Atlanto-Axial Joint / Q000601:surgery*; D002648:Child; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010985:Platybasia / Q000601:surgery*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods*; D055815:Young Adult
Anterior transoral release; Basilar invagination; Irreducible atlantoaxial dislocation; Occipitocervical fusion; Open reduction