19 Harley St, London, W1G 9QJ, UK

Biomechanical analysis of osteotomy type and rod diameter for treatment of cervicothoracic kyphosis

STUDY DESIGN: Biomechanical laboratory research. OBJECTIVE: To characterize the structural stiffness of opening and closing wedge osteotomies and the independent effect of rod diameter. SUMMARY OF BACKGROUND DATA: Traditionally, C7 opening wedge osteotomy (OWO) has been performed for patients with ankylosing spondylitis. For patients without ankylosing spondylitis, closing wedge osteotomy (CWO) may be considered for more controlled closure. Biomechanical characteristics of the two osteotomy alternatives have not yet been analyzed. METHODS: Nondestructive pure moment flexion/extension (FE), lateral bending (LB), and axial rotation (AR) tests were conducted to 4.5 Nm on cadaveric specimens (C4-T3). All specimens underwent posterior bilateral screw-rod fixation with 3.5 mm and 4.5 mm Ti rods, whereas half received OWO and half received CWO. RESULTS: Independent of osteotomy type, constructs with 4.5 mm rods exhibited a significant increase in stiffness compared to 3.5 mm rods in all bending modes (P < 0.01). Relative to 3.5 mm rods, 4.5 mm constructs showed an increase in stiffness of 31 +/- 12% for FE, 37 +/- 39% for LB, and 31 +/- 11% for AR. At the osteotomy site, there was a 43 +/- 23% increase in FE stiffness, 45 +/- 36% in LB, and 41 +/- 17% in AR. Independent of rod diameter, CWO was significantly stiffer than OWO (42% for the construct and 56% across the osteotomy) in FE bending only (P < 0.05). CONCLUSION: The surgeon can expect a similar increase in stiffness in switching from 3.5 mm to 4.5 mm rod independent of osteotomy type. The increased stiffness of CWOs has an anatomic basis. OWOs disrupt the anterior longitudinal ligament (ALL) and leave a significant anterior gap whereas CWOs create a wedge through the vertebral body and leave the ALL and the discs above and below the osteotomy intact. The closure in CWOs leaves no anterior gap providing greater axial loading stability. This greater bone on bone contact in CWOs is likely a significant reason for the anterior stiffness and may provide greater fusion rates in the nonankylosing spondylitis patient population Keywords : Aged,Aged,80 and over,Biomechanical Phenomena,Bone Nails,Cadaver,Cervical Vertebrae,Female,Humans,instrumentation,Kyphosis,Male,methods,Middle Aged,Osteotomy,pathology,physiopathology,Range of Motion,Articular,Rotation,surgery,Thoracic Vertebrae,Treatment Outcome,, Analysis,Osteotomy,Type, acupuncture for costochondritis

Date of Publication : 2011 Apr 15

Authors : Scheer JK;Tang JA;Buckley JM;Deviren V;Pekmezci M;McClellan RT;Ames CP;

Organisation : Biomechanical Testing Facility, Orthopaedic Trauma Institute, San Francisco General Hospital, San Francisco, CA, USA.

Journal of Publication : Spine (Phila Pa 1976 )

Pubmed Link :

The London Spine Unit : Harley Street UK. Specialists in Cutting Edge Technologies for Spinal Surgery

Make an Appointment 

Trustpilot Reviews
Doctify Reviews
Top Doctor Reviews

Biomechanical analysis of osteotomy type and rod diameter for treatment of cervicothoracic kyphosis | Https//wwwenglandnhsuk/commissioning/wp-content/uploads/sites/12/2015/10/d14-pa-cerv-disc-replcmnt-spnl-degenpdf

What our patients say ...

Consultant Spinal Surgeon
Consultant Spinal Surgeon
Consultant Spinal Surgeon
Consultant Spinal Surgeon
Consultant Spinal Surgeon
Consultant Spinal Anaesthetist

This surgical technique consists of a percutaneous approach for the treatment of small to medium size hernias of the intervertebral disc by laser energy. The main objective is to reduce the intradiscal pressure in the nucleus pulposus

Laser Disc Surgery can be performed under local anaesthetic as a day case at our centre on the prestigious Harley Street.
What is London spine unit and How it Works

The London Spine Unit was established in 2005 and has successfully treated over 5000 patients. All conditions are treated.

treatment of all spinal disorders

The London Spine Unit specialises in Minimally Invasive Treatments allowing rapid recovery and return to normal function

Trusted by patients worldwide

The London Spine Unit provides the highest quality care to all patients and has VIP services for those seeking exceptional services

If you have any emergency Doctor’s need, simply call our 24 hour emergency

Your personal case manager will ensure that you receive the best possible care.

Call Now 

+44 844 589 2020
+44 203 973 8810