Fig. 30.1
(a) Schematic overview of lengthening nail in a femur. 1. Locking bolts. 2. Proximal nail with a valgus bend of 18°. 3. Distal expandable nail part. 4. Proximal femur. 5. Single-outer cylinder. 6. Distal femur. (b) Schematic overview with details of the proximal part of the nail. 7. Inlet tube. 8. Conical coupling with locknut, fixing the supply tube in the valve housing. 9. Valve housing with the check valve spring. 10. Fluid passage. 11. Locking holes. 12. Actuator 13. Piston. (c) Safety lock interface between the double cylindrical housing and the expandable distal nail part, preventing collapse of the nail. Only available in the lengthening nail. 13. Recessed locking slot – lateral view. 14. Recessed locking slot – anteroposterior view. 15. Locking wedge housing the two spring loaded anchor pins. 16. Spring loaded anchor pins
Fig. 30.2
(a–d) The hydraulic nail. (a) Overview of the hydraulic locking nail. (b) Situation before insertion of the flexible inlet tube into the tip of the nail. (c) Close-up view after connecting the flexible inlet tube into the tip of the nail. (d) View of the distal part of the nail
30.3 Surgical Procedure
For femur and tibia, the medullary canal is reamed up to 14 mm. An osteotomy at the metaphyseal level is performed; for the femur 6 cm below the lesser trochanter and for the tibia 8 cm below the joint line. The osteotomy is prepared first by drilling multiple holes and finished with a chisel. The far cortex is broken by a twisting movement. A triangular flange of bone is created at the trans-cortex, improving a prolonged bone contact. Care is taken to minimize trauma to the soft tissues. Bone chips taken from the reaming process are pushed into the osteotomy site, using the incision made for the osteotomy. The hydraulic nail is prepared on the table by fixing the flexible polyimide tube on the tip of the nail. By injecting and releasing the arachis oil from the actuator, a degassing (depletion of air) of the nail is performed. Without undue force, the nail is driven down by hand and locked distal and proximal from the distraction site. In case of a polyimide tube, a hollow needle is used to bring the inlet tube out of the skin, some 10 cm from the proximal skin incision. Intra-operatively, the nail is pressurized via the polyimide tube with the hand pump. When slight distraction is seen at the osteotomy site and no collapse of the nail is seen on image intensification, the operative procedure is finished. A resorbable fleece of collagen embedded with gentamicin (Duracoll®) is wrapped around the subcutaneous trajectory of the inlet tube.
After 10 days of rest, the hydraulic nail is activated daily by attaching the hand pump to the inlet tube and slowly turning the handle of the hand pump clockwise. This process takes 3 min and is not painful for most of our patients. In some cases the patients describe a “pressure sensation” in their leg. This sensation lasts for 2 h and gradually subsides. With fluoroscopy, we could observe in three patients the progression of the nail distraction 4 h after the fluid injection. A possible explanation for this phenomenon could be the change in liquid temperature, causing an additional pressure increase. No analgesics are used. Weight-bearing of up to 20 % of body-weight is started during the distraction period for the transport nails. For lengthening nails no-weight bearing is advised until regenerating callus is seen. Inflated, the nail can withstand more than 4,000 N axial force. Every week the progression of the lengthening process is monitored by radiographs of the limb (Fig. 30.3a–k). At the end of the procedure, the flexible inlet tube is cut, flush with the nail tip. This is done by a percutaneous incision under local anesthesia.
Fig. 30.3
A 15 year old boy was ejected out of a mobile home after a frontal collision and became incarcerated under the burning cabin. Third degree burning wounds of both legs associated with a gustilo Grade IIIb fracture of his right proximal tibia and a tibial defect fracture of the distal third of his left tibia were seen. (a) Anteroposterior view of the left tibia at admission. The large bone defect of the distal tibia and the traumatic exorotation of the foot are clearly visible. (b, c). The left lower leg was stabilized with a unilateral external fixator spanning the ankle. The bone defect of his right tibia (9 cm) was treated according to the principles of Masquelet [22]: a cement spacer with the volume and form of the bone defect was placed in the defect. The soft tissue defect was covered with a free latissimus dorsi flap. Anteroposterior (b) and lateral (c) views of the lower leg after primary treatment. (d, e) The bone defect of the left tibia was consecutively stabilized with a transport nail. Because the distal third of the tibia was lacking, the fibula was used as strut for the locking of the transport nail. Anteroposterior (d) and lateral (e) radiographs taken at the end of the bone transport. Notice the two screws in the middle of the tibial transport nail. One bears the plunger of the piston and brings down the tibial bone segment, the other is used to lock the transported bone segment. (f, g) Anteroposterior (f) and lateral (g) radiographs taken at the end of the bone maturation. (h, i) Two years after tibial bone transport a lengthening procedure of the left tibia was done, compensating 48 mm of shortening. No infection nor technical failure occurred. Anteroposterior (h) and lateral (h) radiographs taken at the beginning of the bone transport. (j, k) Anteroposterior (j) and lateral (k) radiographs taken at the end of the bone transport. The patient can walk with a slight limb due to limitation of his ankle movement. He has no pain and sensation of his plantar sole is preserved
30.4 Personal Experience
The authors present all patients treated with this nail from February 2003 until recently. In total, 85 patients were treated with the hydraulic nail, 48 tibiae and 37 femora. In 20 cases a hydraulic transport nail was used, four times in a femur and 16 times in a tibia. In all except two cases, the indication was a post-traumatic bone healing problem. There were 69 males for 16 females with a mean age at surgery of 43.1 years (range 17–73 years). Twenty-nine patients had a history of tobacco abuse (more than a package per day) or were actually smoking during treatment. The mean daily distraction rate was 1.6 mm (range 0.8–1.8 mm) for the femur and 1.3 mm (range 1.25–1.3 mm) for the tibia. The necessary pressure to advance the distraction in the femur was 46 Bar (range 28–82 Bar), and in the tibia 27 Bar (range 20–42 Bar). The mean femoral lengthening was 4.8 cm (range 3–7 cm). The mean tibial lengthening was 5.5 cm (range 3–8 cm) (Fig. 30.4a–l). The mean femoral transport distance was 6 cm (4–12 cm), whereas the mean tibial transport distance was 3 cm (2–5 cm). The lengthening index for the femur was 6.7 days/cm, for the tibia 7.9 days/cm.
Fig. 30.4
A 27 year old man was involved in a labor-related accident and sustained a subtotal amputation of his right lower leg. (a) Clinical picture of the right lower leg at admission. (b, c) As an emergency procedure the lower limb was shortened to facilitate the microvascular suture of the posterior tibial artery and vein. The tibia fracture was provisionally stabilized with an intramedullary nail (UTN®, Synthes). Cerclage wires and a fibula plate were used for additional stabilization. Anteroposterior (b) and lateral (c) radiographs of the right lower leg after primary surgery. One week after trauma, a latissimus dorsi free flap was used to cover the soft tissue defect. (d, e) To compensate for shortening of 5 cm, a hydraulic lengthening device was inserted after wound healing. Anteroposterior (d) and lateral (e) radiographs of the right lower leg short after the application of the hydraulic nail and osteotomy of the tibia. Of notice is the removal of the proximal screws of the fibular plate, to allow the lengthening of the leg. (f, g) At 6 weeks, lengthening of the tibia was stopped and the flexible inlet tube cut off. Anteroposterior (f) and lateral (g) radiographs after 5 cm of lengthening.(h) Image intensification control 1 month later, showing a good bridging callus (i, j) anteroposterior (i) and lateral (j) radiographs of the right lower leg after 1 year, showing complete bone healing. (k, l) At 1 year, the patient was able to restart his work as a construction laborer. Clinical picture of the right lower leg from anterior and posterior
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