A tale of two tibias: a review of treatment options for congenital pseudarthrosis of the tibia

Abstract

Purpose: Two common treatment options for congenital pseudarthrosis of the tibia (CPT) are intramedullary fixation following resection/shortening of the pseudarthrosis site and reconstruction with an Ilizarov external fixator following resection. We present in detail a narrative of two cases with similar degrees of tibial dysplasia associated with NF-1 treated using these different methods and followed to completion.

Methods: Technical issues and details of the treatment methods from case reports are discussed in depth. The eventual profoundly different outcomes are correlated to the technical variations used.

Results: Treatment with the Charnley-Williams rodding method and aggressive bone grafting supplemented by rh-BMP2 resulted in a normal functioning limb at maturity, while treatment with first, an ineffective version of IM rodding, followed by two sessions of bone transport using an Ilizarov fixator failed to gain useful union and eventually resulted in amputation.

Conclusions: Technical details, heretofore inadequately reviewed in the literature, are crucial to the success of either of these commonly utilized treatment methods for CPT.

Fig. 1

a–c Clinical appearance of patient at presentation. Cutaneous lesions include both mastocytosis lesions (darker) and cafe-au-lait spots (lighter)

Fig. 2

a Presenting X-ray at age 2 years and 6 months. b Intraoperative view of periosteal “rind” strangulating the tibia (arrows)

Fig. 3

a Intraoperative X-ray showing amount of acute tibial resection at the pseudarthrosis site. b Williams rod technique. The male–female connection is at the distal tibia epiphysis, with the male portion to be unscrewed and removed through the bottom of the foot. The interlocking Steinmann pin is being placed. c Intraoperative view of fibula osteotomy and shortening. Note bone ends in contact. d Immediate postoperative X-ray of IM rod with Steinmann pin interlock, in cast. e, f Loss of distal fixation with persistent tibial discontinuity and healed fibula

Fig. 4

First revision at 4 years of age.a A new rod with two distal interlocking screw holes was inserted antegradely and locked in both metaphysis and epiphysis. An additional bone graft was also added to the pseudarthrosis and the synostosis sites.b Four months later, the epiphyseal locking screw was removed, and the distal tibial epiphysis grew off the end of the rod

Fig. 5

Recurrent symptoms 3 years later. Rod migration with loss of distal fixation are seen

Fig. 6

Second revision. A new C-shaped Ender nail has been placed from a new proximal entry site, and a proximal tibial osteotomy performed to assist sagittal plane correction, along with a new fibular osteotomy. The original pseudarthrosis site has been left undisturbed

Fig. 7

Healing of both osteotomies 2 months later

Fig. 8

Most recent follow-up (age 16 years)

Fig. 9

Clinical appearance at age 14 years. There is no atrophy of the left leg

Fig. 10

Initial X-ray appearance, left tibia, at age 9 months

Fig. 11

Three months s/p initial surgery at age 1 year—type-C procedure. No evidence of callous formation. A second grafting procedure was performed

Fig. 12

a, b Clinical photos at age 5 years with atrophy and varus deformity

Fig. 13

X-ray at age 5 years of persistent nonunion, with proximal migration of the distal tibia segment (preop. Ilizarov frame #1)

Fig. 14

a, b Anteroposterior and lateral X-rays 3 weeks following transport frame placement. Slight distraction at the proximal corticotomy site has occurred, with distal movement of the transported segment of the tibia using oblique longitudinal olive wires

Fig. 15

a, b Clinical appearance of transport frame with oblique longitudinal wires attached to the distal ring

Fig. 16

a, b X-ray nearing completion of transport. The bone ends are not aligned, requiring operative “open reduction” with frame revision to achieve “docking”. c Intraoperative view of offset bone ends (distal end left). The fibrous tissue deflecting the proximal bone end is seen (arrow). d, e Reduction and bone grafting of bone ends. The transported segment is now fixed to an intercalary “float” ring by transverse wires for segmental compression

Fig. 17

X-ray of tibia in cast at frame removal, age 5 years and 8 months. Windows in the cast were cut in order to place a low-pulse ultrasound generator at the pseudarthrosis site to stimulate healing

Fig. 18

X-rays and clinical photos at age 9 years, with persistent non-union

Fig. 19

a Intraoperative view of pseudarthrosis site prior to resection: frame no.2 4/05. b Resection of tibial pseudarthrosis and fibulectomy prior to acute shortening. c Maximum acute shortening allowed by the surrounding soft tissues. d, e Tibia transport frame. The fibula is fixed to the proximal and distal rings only, with the tibia alone being transported by the middle ring. Bulging of the soft tissues around the resection site is from maximum allowed acute compression. f Pin tracts cutting the skin as distal transport of the tibia occurs (ankle, top). g, h Completion of tibial transport, with misalignment of the tibial ends in the coronal plane. The fibulectomy gap is unchanged from the beginning of tibia transport. i Intraoperative X-ray during open reduction of tibial ends to achieve “docking”. j Intraoperative X-ray following bone grafting, addition of BMP, and compression across the docking site. k Intraoperative view of sponges soaked with rh-BMP being applied to the docking site

Fig. 20

a, b X-rays in cast following frame no.2 removal

Fig. 21

X-rays 6 months after frame removal, showing robust healing of the tibia but severe ankle valgus and fibular discontinuity

Fig. 22

Clinical photos 6 months following frame no.2 removal. Diaphyseal and ankle valgus are readily apparent

Fig. 23

a X-ray following distal tibia-fibula synostosis and medial hemiepiphyseodesis. b Eight-plate hemiepihyseodesis of medial proximal tibia

Fig. 24

New fracture at distal tibia through screw holes

Fig. 25

X-ray 4 months following fracture, with no evidence of healing

Fig. 26

Summary of case 1:, a Clinical appearance at age 2 years and 6 months, b age 2 years and 6 months, c intraoperative age 3 years and 2 months, d age 4 years (s/p first revision), e age 7 years, f age 8 years (s/p second revision), g–i age 16 years (last f/u)

Fig. 27

Summary of case 2: a age 1 year, b age 5 years and 3 months—s/p type-“C” procedure with non-union,c1, c2 age 5 years and 6 months—first transport, prior to “docking”, d age 6 years—clinical appearance,e1, e2 age 6 years,f1, f2 age 9 years—second transport, prior to “docking”,g1, g2 age 10.5 years—valgus + fibula non-union, h age 10.5 years—clinical appearance, i pathological fracture after 4-month casting