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Limb Lengthening with a Submuscular Locking Plate
Journal of Bone and Joint SurgeryEssential Surgical Techniques
April 2014,vol3Chang-Wug Oh et al
Kyungpook N U Hospital, Republic of Korea
Level of evidence Ib
PRESENTER : Dr SAUMYA AGARWAL
Junior resident Dept of Orthopaedics J.N. Medical College and Dr. Prabhakar Kore Hospital and MRC, Belgaum
INTRODUCTION
Limb lengthening with a submuscular locking plate is a good alternative for patients especially children, in whom lengthening over an intramedullary nail would be difficult.
• Distraction osteogenesis with an external fixator is widely used to treat limb length discrepancy
• But prolonged external fixation can cause many complications such as
pin track infection joint instability and stiffness refracture after fixator removal.
Lengthening over an intramedullary nail
• shortens duration of external fixation• protects distracted bone during
consolidation phase • reduces rate of complications when
compared external fixator alone.• regain movement more quickly • return to activities of daily life in less
time.
• It is difficult to use an intramedullary nail when :
patient has a narrow medullary canal bone deformity open physes joint contracture may lead to femoral head osteonecrosis in
children.
• Submuscular fixation with a locking plate is a recent advance in fracture treatment
• Has advantage of providing angular stability
and preserving the periosteal and endosteal
blood supply.
• Limb Lengthening with a Submuscular Locking Plate is performed with
4 steps 2 operations
STEP 1 : External fixation for lengthening with . submuscular plating
Submuscular plating external fixation with corticotomy
A. Submuscular Plating
Tibial lengthening:• Supine position
• 3-4 cm incision in area of Gerdy’s tubercle in proximal tibia
• Iliotibial band and tibialis anterior fascia is incised and muscle is elevated
• a submuscular tunnel is made along lateral surface of tibia with periosteum elevator
• a 3 hole plate is inserted into submuscular tunnel extraperiosteally
• 3 locking screws are inserted in proximal portion of plate
Femoral lengthening :
• Lateral / supine position
• 3-4 cm incision along lateral aspect of greater trochanter
• Iliotibial tract and vastus lateralis fascia incised
• vastus lateralis muscle dissected
• Submuscular tunnel made along lateral surface of femur
• An anterior bow 4.5 mm straight locking compression plate is used
• Plate inserted along lateral surface of femur through submuscular tunnel
• 3 or 4 locking screws are used to fix plate to proximal segment.
• In some cases , use of a flexible intramedullary nail helps to stabilize the distal segment and prevent angular deformity while lengthening is taking place.
B. External fixation with corticotomy
• External fixator with lengthening frame is used.• For tibia, monolateral frame is fixed to
medial side of each segment using 3 half pins.• For femur, 3 half pins are fixed to lateral
side of proximal and distal segment of plate.
• Cross contamination should be avoided.• Half pins and wires used for external
fixation should not touch plate or screws.• A fibular osteotomy is done and with
the help of 1 or 2 , 3.5mm cortical screw the distal tibiofibular joint is secured.
• Now percutaneous corticotomy is performed
• 1 cm incision is taken about 1 cm below the distal screw of the proximal segment.
• Multiple drill holes are made and complete corticotomy is done.
• Corticotomy can be done either before palting or after plating.
Step 2 : Lengthening
• Distraction is started after 7 to 10 days• At the rate of 1mm per day• 4 times a day• Partial weight bearing and physiotherapy
is started to maintain movement of adjacent joints• Radiograph is taken weekly to monitor
progress.
Step 3: Locking of the distal segment and removal of the external fixator
• Whole extremity together wih external fixator drapped.
• Under C-Arm, empty plate holes of the distal segment are marked for planned screw fixation.
• A stab skin incision is taken and soft tissue dissection is done.
• At least 3 bicortical screws are placed percutaneously through plate into distal segment.
• Now wound is closed and external fixator is removed.
• Wound made by external fixator are then cleaned and dressed.
4. Postoperative care
• Mobilization and partial weight bearing started immediately after fixator is removed.
• A radiograph is taken every 4 to 8 weeks until the distraction callus is fully consolidated.
• Patient is allowed full weight bearing walk with crutches when signs of osseous consolidation are observed in atleast 3 cortices.
• Slowly wean the patient off the crutches.
RESULTS
• 10 Patients were operated for limb lengthening
• Mean amount of legthening 4cm• External fixator was in place for 61 days• mean healing index was 48.1 days/cm• Target length was achieved in all the
patients.
• Total 9 complications and all resolved before last follow up visit.• 4 superficial pin track infection resolved
with oral antibiotics.• 4 patients had joint stiffness resolved with
physiotherapy.• One patient sustained a tibial fracture for
which he got operated.
• All 10 patients were walking with full, unassisted weight bearing excellent joint motion solid union at lengthening site normal limb alignment
INDICATIONS
• Skeletally immature patients because of open physis narrow medullary canal osteonecrosis of the femoral head
• Nail insertion is difficult: Presence of osseous deformity Joint contracture Previous arthroplasty
CONTRAINDICATIONS
• Plate is inherently inferior to intramedullary nail in terms of bending and axial stiffness.
PITFALLS and CHALLENGES
• Half pins or wires should not contact the plate or screws to avoid cross contamination.
• To provide sufficient stability longer plate should be choosen.
• Use of protection device like brace is recommended until sufficient consolidation is achieved.
• In skeletally immature patients screws should not intrude the epiphyseal plate.
CLINICAL COMMENTS
• Lengthening with a submuscular locking plate did not disturb the regeneration of distraction callus.
• Healing indices achieved were similar to those with conventional lengthening without plate.
• This techniques permit earlier removal of the external fixator.
THIS STUDY ALSO SAY’s:
• The use of plate of sufficient length, fixed with 3 or more bicortical screws per segment provides adequate stability.
• Since plate is inherently inferior to intramedullary nail in terms of bending and axial stiffness, authors prefer to use intramedullary nail when it can be inserted without undue difficulty.