Telescopic Nails in Osteogensis Imperfecta

Shady MahmoudAssistant lecturer

Orthopaedic surgery department - Ain Shams University

What is OI? A hereditary disease (AD or AR) caused in 70% of cases

by a mutation of 1 or 2 genes (COL1A1 and COL1A2), which encode type 1 collagen (1)

It is approximately 1 in 10,000 live births

The major clinical features of OI are: Bone fragility with or without multiple fractures,

osteopenia, and skeletal deformities of long bones Spine deformity in the form of scoliosis in 39% to 80% Craniocervical abnormalities are also associated as

basilar invagination, basilar impression, and platybasia (2)

How is it classified?

How to treat bone fractures and deformities? Prevention:

Pamidronate, has shown its efficacy in reducing fracture rates and pain, enhancing bone density parameters, and improving the quality of life in these children. (2) So, they start standing at a younger age than the past (3) However, it has no effect on preexisting bone deformities (2)

Treatment:

Most fractures can be treated by immobilization especially if < 2 years. However, surgical treatment is sometimes required (long bones in > 2 years) (3)

What not to do? PlatesScrew fixation in fragile bone is poor

Plates create stress risers and fractures above and below the plate are likely to occur

Skeletal traction- The traction pin may cut

through the bone- Damage to the growth plate

may occur

What to do?

Intramedullary rods for long bone fractures and deformities are the

treatment of choice (3)

Solid Rush pins or K wires Sofield - Millar procedure :

multiple realignment (“shish kebab”) osteotomies over a nontelescopic intramedullary rod (4)

The revision rate is high as 73%, and complications such as rod migration are common. (4)

So, it is better used in adolescents and patients with limited growth potential (popcorn physis) (3)

Telescopic 4 main types are developed:Bailey-Dubow, Sheffield, Fassier-Duval, and

interlocking telescoping rods

These rods have a female hollow nail anchored in the proximal epiphysis of the long bone and a male solid nail anchored to the distal epiphysis. They are elongated as the child grow. So, less revision rates compared to solid (4)

According to a study (5), Mobility status and bone growth were better in telescopic than in solid rods.

The overall implant related complication rate was 28.6% in telescoping in comparison to 68.4% in solid ones. (5)

Rod migration was twice more common in solid. Bone outgrowing the rod and breakage of rods

with fracture was seen in solid rods only. The three-year survival rate for telescoping rods

was 92.9% in contrast to 68.4% for solid rods. The reoperation rate was 7.2% in telescoping

and 31.6% in solid rods. (5)

Rod diameter:Larger diameter gives more stability but causes bone loss

around the rodTherefore, thinner rods are recommended acting as

internal tutor and not replacing the boneLeaving 2 mm around the rod in any plan is a safe

method(3)

Rod length:Pre-operative templates are essential taking into account

the osteotomies needed to straighten the bone.Measure the length (L) between greater trochanter and

distal growth plate Female rod length is (L) - 7 mmMale rod length is (L) + (10-15) mm

Methods of fixation

Open osteotomy:Better in narrow marrow

diameter (distal segment is reamed)

But, more soft tissue damage and risk of devascularization (3)

Percutaneous osteotomy:

Limited use in narrow diameter but has the advantage of soft tissue respect

According to the need of arthrotomy they are divided into: Those need:Bailey-DubowSheffield

Those do not need:Fassier-DuvalInterlocking

Those need arthrotomy has limited use in tibia compared to femur as they have a higher complication rate compared to femoral rodding (3)

The surgical trauma to the ankle ligaments and the permenant damage to most of the wieght bearing surface of the ankle joint limit its use (3)

Bailey-Dubow T piece is not a component of the rod and has to

be attached to it No locking mechanism ensures the fixation to

epiphysis Need arthrotomy for insertion The reoperations rates are 21% - 32% (4)

Complications of Bailey and Dubow: Proximal rod migration Disengagement of the epiphyseal T-piece (6)

Bending Infection

Sheffield Design with a fixed T-piece on either end It is rotated intraoperatively for better fixation

within the epiphysis (4)

The reoperation rate is 20% (4)

Need arthrotomy for insertion

Fassier-Duval The anchorage is achieved through

screw type fixation by threaded portions at the proximal and distal ends with improved “screw-in” fixation (4)

The advantage of this rod over the traditional Bailey-Dubow and Sheffield rods is the single proximal entry point(2)

Reoperation rate is 13% in a study on 15 patients (4)

FD rods are safe and pose no risk of migration, heating effects, or artifact when undergoing an MRI of the spine using a 1.5 T magnet (2)

No arthrotomy

Open Percutaneous

Interlocking The female rod is the same as Sheffield telescopic

rod system while The male rod has a hole at its distal tip to receive the interlocking pin (7)

A revision rate of 9% at 2 years and 28% at 3 years.(4)

No need for arthrotomy proximal migrat--ion is 12.5 %(7)

Refrences 1) Zeitlin L, Fassier F, Glorieux FH. Modern approach to children with osteogenesis imperfecta. In:

Journal of Pediatric Orthopaedic B. Johari A ,ed. Philadelphia, Pa:Lippincott Williams & Wilkins; 2003 Mar;12(2):77-87.

2) Makhdom A, Kishta W, Saran N et al. Are Fassier-Duval Rods at Risk of Migration in Patients Undergoing Spine Magnetic Resonance Imaging?. In: Journal of Pediatric Orthopaedic Hensinger r, Thompson G, eds. Philadelphia, Pa: Lippincott Williams & Wilkins; 2015 Apr-May;35(3):323-7

3) Fassier F, Glorieux F. Osteogenesis imperfecta. In: surgical techniques in orthopaedics and truamatology. Duparc DJ, ed. Philadelphia, Pa: Mosby Elsevier; 2003, 55-050-D-30

4) Birke O, Davies N, Latimer M, et al. Experience With the Fassier-Duval Telescopic Rod: First 24 Consecutive Cases With a Minimum of 1-Year Follow-up. In: Journal of Pediatric Orthopaedic B. Johari A ,ed. Philadelphia, Pa:Lippincott Williams & Wilkins; 2011 Jun;31(4):458-64

5) EL-ADL G, KHALIL M, EL-LAKKANY r, et l. Telescoping versus non-telescoping rods in the treatment of osteogenesis imperfecta. In : acta orthopaedic belgica. Barbier O, De Smet L ,eds. 2009, 75, 200-208

6) LANGSTEVENSON A, SHARRARD W. INTRAMEDULLARY RODDING WITH BAILEY-DUBOW EXTENSIBLE RODS IN OSTEOGENESIS IMPERFECTA. In: The Journal of Bone & Joint Surgery. Swiontkowski M, ed. Needham, MA: JBJS. 1984 Mar;66(2):227-32.

7) Joon Cho T, Ho Choi I, Chung C, et al. Interlocking Telescopic Rod for Patients with Osteogenesis Imperfecta. In: The Journal of Bone & Joint Surgery. Swiontkowski M, ed. Needham, MA: JBJS. 2007;89:1028-1035