Infections are common. Most are superficial pin site infections that seldom lead to deep osteomyelitis. Oral antibiotics usually suffice. Serious cases do occur. Toxic shock syndrome and necrotizing fasciitis have been reported. These patients present ill, with loss of appetite, decreased activity, and febrile. A diffuse rash may be present with toxic shock syndrome. Urgent attention is required, with urgent and aggressive resuscitation and initiation of empiric intravenous antibiotics.

Institute physical therapy for passive knee flexion and extension. Splint the knee in extension at night. Allow “partial weight bearing” (the weight of the leg, which is generally considered as 1/6 of body weight). Consider electrical stimulation of the quadriceps to maintain tone. Supervised physical therapy should be done daily during the week and with the family on weekends.

Begin distraction after a latency period of 5 days (Fig. 1.1J). Lengthen at a rate of 0.25 mm QID. Later on, this rate may be adjusted up or down depending on bone formation and knee flexion. One strategy to consider is to slightly overlengthen (by up to 1 cm) and then shorten. This compresses the regenerate bone and may speed healing.

Fixator removal/locking (Fig. 1.1K-L): Once the desired length has been achieved, the patient returns to the operating room for locking of the rod and external fixator removal. It is important to insert the distal interlocking screws before removing the external fixator, in order to maintain length. Ideally, preoperative planning included an estimation of where the locking holes in the distal end of the nail would be at the end of lengthening, relative to the external fixator pins. In the operating room, position the patient supine with a bump under the ipsilateral hemisacrum, and bring the image intensifier to the true lateral position, to confirm that you can see “perfect circles” for the distal interlocking sights. If necessary, portions of the external fixator can be modified to provide better visualization and access. For example, the pin trolleys can be locked to the rail, and the compression/distraction rod removed. Such modifications should be completed before prepping and draping. If the external fixation pins are close by the locking site, it may be advisable to insert the locking screws from the medial side, to avoid surgical proximity to the colonized pin sites. This may be problematic in the diaphysis, due to proximity of the femoral artery. In order to minimize the risk of infection after inserting the locking screws, a meticulous prep and drape procedure is recommended: wash the leg and fixator with antimicrobial soap and then rinse with saline or alcohol. Next, prep the skin and the fixator with an alcohol-based iodine or chlorhexidine solution, painting the pin sites last. Apply sterile drapes, and then take Betadine- or chlorhexidine-moistened sponges and wrap each pin site in them to isolate the contaminated pin-skin interface. Apply sterile towels to those parts of the external fixator that can be covered, minimizing the exposure to less than fully sterile components. Change gloves, and then begin the procedure. Once the interlocking screws are inserted, and the wounds sutured and dressed, the fixator may be removed. Postoperatively, limit weight bearing to 25 % of body weight. Advance to full weight bearing when there is healing in at least two out of four cortices in the AP/LATERAL views of the regenerate bone.

If regenerate bone formation is poor at the time of distal nail locking and fixator removal, consider concentrated bone marrow injection to the regenerate. Several commercially available systems are present, such as the BioCUE (Biomet, Warsaw, Indiana, USA) or Magellan (Arteriocyte Medical Systems, Hopkinton, Massachusetts, USA).

With a monolateral fixator, the femur is sometimes pushed into varus alignment. Once the rod is locked and the fixator removed, all or part of the varus will realign itself, as there is no longer a moment from the fixator pushing the bone into the varus position.

Elective removal of the internal rod may take place 1 year later, provided there is healing of all four cortices as seen on AP/LATERAL radiographs. Dynamization can be performed by removing the distal locking screws provided at least two cortices are solidly healed.

Deep infection can occur early or late. If early, then use suppressive antibiotics until all the length is achieved. When locking, consider nail exchange for an antibiotic-impregnated cement-coated locked nail. Alternatively, lock the original nail, with plans to do a nail exchange when the pin sites are well healed. For late infections (defined as infections that present after there is solid healing of at least two cortices of the bone), rod exchange with an antibiotic-impregnated bone cement-coated chest tube nail (with a guidewire core) can be done. When exchanging an infected nail, thorough reaming of the canal and debridement of sinus tracts is required.