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Ilizarov external fixator: acute shortening and lengthening versus bone transport in the management of tibial non-unions
Injury, Int. J. Care Injured (2005) 36, 662—668
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Ilizarov external fixator: acute shortening and lengthening versus bone transport in the management of tibial non-unions J. Mahaluxmivala, R. Nadarajah *, P.W. Allen, R.A. Hill Limb Reconstruction Unit, Princess Alexandra Hospital, UK Accepted 21 October 2004
KEYWORDS Ilizarov; Circular frames; External fixator; Acute shortening; Bone transport; Fractures; Tibial; Non-union; Infection; Deformity
Summary Eighteen patients with tibial shaft non-unions were treated by the Ilizarov method between March 1995 and September 2001 by the senior author. Three subgroups of six patients each were treated by either acute shortening and lengthening, bone transport or simple stabilisation with a frame. All aspects of nonunion, infection, shortening, deformity and bone loss were addressed by using Ilizarov principles. There were 10 cases of infected non-unions in the entire series. Bone resection in the shortening group was between 3 and 6 cm (median 4.6) compared to 3—7.5 cm (median 5.9) in the bone transport group. Union was achieved in all the patients with the average time to union at 12.1 months, 17.2 months and 8.0 months, respectively. The bone transport group required additional bone grafting in five patients (83.3%) prior to union compared to one (16.7%) in the acute shortening group. # 2004 Elsevier Ltd. All rights reserved.
Introduction Surgical reconstruction of tibial non-unions with or without associated infection can be a great challenge for the orthopaedic surgeon. These nonunions are usually the result of high-energy trauma accompanied by extensive soft tissue damage at the time of initial injury. Bone defects can result from these injuries primarily or secondarily from the subsequent debridement for contamination or infection. In the long term, there may be problems * Corresponding author. Present address: 20, Britten Court, Abbey Lane, Stratford, London El 5 2RS, UK. Tel.: +44 208 519 5519; fax: +44 208 519 5520. E-mail address: [email protected] (R. Nadarajah).
of deformity, leg length discrepancy, pseudoarthrosis and soft tissue healing. Limb shortening as a method of treatment has been to shown to be undesirable.16 We assessed two methods of treating tibial nonunions with the llizarov technique. The purpose of this study was to assess and compare acute shortening and lengthening versus bone transport, principally looking into the duration of treatment and requirement for bone grafting at the resected non-union site.
Material and methods This study was based on a tertiary referral of 18 patients to our Limb Reconstruction clinic between
0020–1383/$ — see front matter # 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2004.10.027
Ilizarov external fixator: acute shortening and lengthening versus bone transport
663
Table 1 Patient demographics Age
Sex
Type of accident
Open fracture G&A type
Previous surgery (number)
Time to presentation (months)
Infection
Smoker
1 2 3 4 5 6
26 37 54 38 28 36
M M M M M M
RTA RTA RTA RTA RTA RTA
Yes, Yes, No Yes, Yes, No
Yes Yes Yes Yes Yes Yes
(3) (3) (2) (3) (3) (l)
27 37 14 10 10 7
No Yes No No Yes No
No Yes Yes Yes Yes No
7 8 9 10 11 12
31 44 38 52 42 28
M M F M M M
RTA Fail Sports Sports Sports Sports
Yes, 3B Yes, 3A No Yes, 3B No No
Yes Yes Yes Yes Yes Yes
(2) (2) (l) (2) (4) (l)
6 18 6 11 11 8
Yes Yes Yes No Yes Yes
No Yes Yes No No Yes
SFS 13 14 15 16 17 18
28 56 63 55 32 25
M M M F M M
Sports RTA Sports Fall Fall Sports
Yes, 3A Yes, 3B Yes, 3B No No No
Yes Yes Yes Yes Yes No
(l) (2) (1) (l) (1)
3 6 7 17 1 10
Yes Yes Yes Yes Yes Yes
Yes No No No No No
Patient/ group AS
3A 3B 3B 3B
BT
AS: acute shortening, BT: bone transport, SFS: simple frame stabilisation, RTA: road traffic accident, G&A: Gustillo and Anderson classification.
March 1995 and September 2001 (Table 1). There were 2 female and 16 male patients, ranging in age from 26 to 63 years (mean 39.6 years). At presentation, a full history was obtained which included details of the initial injury and previous surgical interventions. On examination, the presence of shortening, deformity, neurovascular deficiency and condition of soft tissue was documented. Delayed union was defined as little or no radiographic evidence of union, 3—6 months following an injury with instability in the fracture site necessitating a change in treatment. Failure of fracture consolidation 6 months after injury was considered a non-union. In 16 patients, there was established non-union on presentation to our clinic, however, in two patients the circular frame was applied within 6 weeks of the initial injury as there were no signs of healing. In these two patients, we anticipated that as a result of the extensive soft tissue stripping and the severity of the fracture communition, non-union would follow. Radiological evaluation of the fracture pattern and deformity was based on Paley’s classification11 (Table 2). Patients were further classified as having an infected non-union if there was a discharging sinus, a positive swab or tissue culture and radiological evidence of infection. All 18 patients were informed about the approximate duration of treat-
ment and the associated complications prior to reconstructive surgery. The patients were divided into three groups. Patients in groups 1 and 2 had tibial segmental defects of more than l cm; group 1 underwent acute shortening and lengthening, whereas group 2 had bone transport. Patients were allocated to these two groups pre-operatively by the senior author (RAH) as they presented to our unit and was independent of the intended amount of bony resection. A third group without segmental defect (
Paley’s classification
Paley’s classification
Group 1
Group 2
Group 3
A2.1 A2.2 Bl B3
0 0 2 4
0 0 2 4
3 3 0 0
Type A: non-unions with less than l cm bone loss; Al: mobile non-union, A2: stiff non-union (A2.1 non associated deformity, A2.2: associated deformity). Type B: non-unions with greater than l cm bone loss; Bl: bony defect with no shortening, B2: shortening with no bony defect, B3: bony defect with shortening.
664
J. Mahaluxmivala et al.
Figure 2 Bone defect in a patient in the bone transport group. The intact fibular aids in maintaining alignment.
Figure 1 Acute shortening after thorough debridement and fibular osteotomy. Proximal corticotomy has been performed.
ment, reaming of the infected medullary canal and resection of infected or non-viable bone was performed so as to obtain healthy bleeding bone on either side of the non-union. Patients in group 1 had a transverse incision at the fracture site so as to facilitate skin closure after acute shortening. These patients also had a fibular osteotomy, which allowed acute compression (see Fig. 1). The corticotomy for lengthening was performed at the proximal tibia at approximately 12 cm from the joint line so as to facilitate an adequate stump if an amputation was required. This corticotomy was carried out percutaneously using a 4 mm drill bit and an osteotome. A complete corticotomy was confirmed clinically and radiologically at the time of surgery. Patients in group 2 did not need a fibular osteotomy as length was maintained but a corticotomy to allow bone transport was performed in a similar manner as described above (see Fig. 2). A standard llizarov frame was applied predominantly with 1.8 mm wire fixation although half pins
were used in some cases. In group 1 (acute shortening), the frame was constructed to permit compression and distraction of the non-union site. In group 2 (bone transport), external transport was used with the transport segment held with one or two wires and a half pin. In group 3, the fracture site was not opened nor was a corticotomy performed but the frame was constructed to permit compression and distraction at the fracture site. Patients with very distal fractures had the foot included in the frame for stability. Three patients had additional soft tissue procedures to aid healing and coverage. Two patients underwent split skin grafting at the time of frame application, whereas one patient in the acute shortening group had a free flap applied prior to frame application. In the post operative period, joint motion and weight bearing exercises were permitted as pain allowed. As a protocol in our unit, the use of nonsteroidal anti-inflammatory drugs is strictly prohibited at all stages of reconstructive surgery. In all groups, weight-bearing mobilisation was actively encouraged. In the acute shortening group (group 1), ankle splintage was needed in those patients without a foot frame until limb length was restored. Distraction at an initial rate of l mm a day in four increments was commenced between day 5 and 7. Pin site care and hygiene was taught to all patients. On discharge, all patients were seen on a regular
Ilizarov external fixator: acute shortening and lengthening versus bone transport
Figure 4
665
Persistent non-union at the docking site.
Figure 3 Union at the fracture site seen in a patient in the acute shortening group prior to frame removal.
basis in the out patients department, where further clinical and radiographic assessment of their progress was made. The initial rate of distraction was altered based on the radiological appearance of the regenerate. In group 1 (acute shortening), compression at the fracture site was maintained till union (see Fig. 3). Distraction at the corticotomy site was continued until limb length equality was achieved. Poor consolidation of the regenerate was treated by encouraging weight bearing and alternate compression—distraction (Concertina technique). In group 2 (bone transport), in addition to assessing the regenerate, radiological assessment of alignment is undertaken to ensure adequate docking. If necessary, the frame was adjusted under general anaesthetic to correct malalignment. After successful docking, if there was no radiological evidence of union at 6 weeks (see Fig. 4), iliac crest graft was applied to the docking site after excision of any interposed soft tissue (see Fig. 5). In group 3 (frame stabilisation), alignment was corrected acutely at the time of frame application. In hypertrophic or stiff non-unions, the non-union
Figure 5 Bone graft applied at the docking site to aid union (same patient in Fig. 4).
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was initially distracted whereas with atrophic or lax non-unions, compression was initially applied. If the non-union was slow to heal, alternate compression— distraction was used. In all patients, the frame was retained until adequate consolidation of the regenerate as well fracture union is seen. Our criteria for radiological healing is the presence of bony consolidation in three out of four cortices. When this is achieved, the patient is admitted for examination under anaesthetic of the fracture and regenerate site under fluoroscopy guidance. If satisfactory, the frame is removed and the limb is left unsupported with instructions to the patients to gradually mobilise to full weight bearing with the aid of crutches. Plaster of Paris immobilisation was only used to correct residual equinus deformities.
Results The mean age of patients was 39.6 years with 2 female and 16 male patients. In all three groups, patients were similar for age, pre-injury health status including cigarette smoking. Nearly all patients had high velocity trauma, with 10 being involved in a road traffic accident. Ten patients in the entire series (five in group 1, four in group 2 and one in group 3) had open fractures in the initial injury with the majority being grade 3B according to the Gustillo and Anderson classification.6 Most patients had at least two previous operative interventions prior to referral to our clinic. In group 2, five patients (83.6%) had locked reamed intramedullary nailing as compared to two patients (33.3%) in group 1 (Table 3). The mean time to Ilizarov surgery in each group from the time of initial injury was 16.2, 12.0 and 6.8 months, respectively. Infection was noted in four patients in group 1, five patients in group 2 and one patient in group 3. At the time of surgery, the decision regarding amount of bone resection was based on the presence of healthy bleeding bone ends. The mean resection being 4.6 cm in group 1 and 5.9 cm in group 2 (Table 4). Table 3 Previous treatments IM nailing External fixator Others
Group 1
Group 2
Group 3
1 5
5 I
0 4
Bone grafting (1)
Exchange Nail (1)
Plating (1)
Exchange nail (1)
Plaster of Paris (1)
Table 4
Amount of bone resection
Patient
Group 1 (cm)
1 2 3 4 5 6 Range Mean
Table 5
Group 2 (cm)
3 4 4.5 5 5 6
3 5 6 7 7 7.5
3—6 4.6
3—7.5 5.9
Additional procedures
Procedures
Group 1
Group 2
Group 3
Adjustment of frame Insertion of wires Bone grafting required Bone graft at docking site Bone graft at regenerate site
0 0 1 0
2 2 5 4
o 0 0 0
1
1
0
Additional procedures were required in two patients in the acute shortening group and all six patients in the bone transport group. These included adjustment of frame and/or insertion of wires to realign the transport segment and also, bone grafting at the docking or regenerate site (Table 5). It was noted that patients in the bone transport group had more procedures done especially bone grafting at the docking site. All 18 patients had at least one pin site infection, but only four patients required hospital admission for intravenous antibiotic therapy. At the time of frame removal, complete eradication of infection was seen in all patients. No patient was left with a residual limb shortening of more than 2 cm as assessed by clinical examination with blocks. Five patients (90%) in the acute shortening group and five patients (90%) in the bone transport group had equal leg length or a discrepancy of less than 1 cm. Union was achieved in all patients, with the average time to frame removal being 12.1, 17.2 and 8.0 months, respectively in all three groups (Table 6). All patients were followed up for at least Table 6
Time to frame removal
Patient
Group 1 (months)
Group 2 (months)
Group 3 (months)
1 2 3 4 5 6
11 9 19 8 12 13.6
12 7 19 24 14 24
3 10 11 6 6.8 11.2
Mean
12.1
17.2
8.0
Ilizarov external fixator: acute shortening and lengthening versus bone transport
18 months after the removal of their Ilizarov frame. No recurrence of infection was seen in any group.
Discussion The Ilizarov method is well established in the treatment of high energy tibial non-unions.4,5,13,15 It is able to address the problems of an avascular segment, infection, deformity and limb length discrepancy. Several authors have compared bone transport with other conventional techniques.3,9 In this study, we compared acute shortening and then subsequent lengthening against bone transport in the treatment of tibial non-unions. The simple stabilisation group was included for comparison. Patients in each group were similar for age and cigarette smoking, which are well documented aetiologies of non-unions.1,14 In this series, we noted that risk factors for extensive bone resection was high energy comminuted fractures treated by locked reamed intramedullary nailing, particularly when the fracture site was opened to facilitate the nailing. There were two cases of thermal necrosis due to jammed reamers that resulted in an avascular segment. Both these patients had extensive intramedullary infection. This problem has been documented in other series.7,10 More procedures were necessary in the bone transport group mainly to correct alignment to ensure accurate docking and bone grafting at the docking site. Malalignment at the docking site has been well documented by many other series looking at bone transport in Ilizarov surgery.12 Additional procedures were not required in the acute shortening group to maintain alignment as the fracture site is acutely compressed. In the acute shortening group, fracture site union was achieved without any additional intervention. However, in the bone transport group 4 patients required bone grafting at the docking site before solid bony union was achieved. It is thought that fibrous capping of the fracture ends as the transport segment descends may be a cause for this delayed union.12 Bone grafting at the docking site has been recommended by a number of authors2,3,9,12 and in our unit, we now routinely perform this. In the acute shortening group, no further surgical intervention was required to achieve union. The number of procedures in the acute shortening group was therefore, similar to the simple frame stabilisation. There was no difference in the consolidation pattern in our two main groups (group 1 and 2). One patient in each group (1 and 2), had bone grafting at the regenerate site to allow for complete healing.
667
Using Paley’s bone result evaluation system, an excellent bone result was achieved in all patients in all three groups.11 This meant that union was achieved with eradication of infection, no residual deformity of more than 58 in any plane, no residual limb length discrepancy of more than 2.5 cm and a bone union wide enough not to require long term bracing or protection. It is interesting to note however, that if the ASAMI (Association for the Study and Application of the Method of Ilizarov) classification is used,8 four patients in the bone transport group and one in the acute shortening group would have a poor bone result merely due to bone graft usage. In our three groups, the average time in the frame was 12.1, 17.2 and 8.0 months (Table 6). In the frame stabilisation group (comparison group), there was no bone loss however the fractures were still high energy comminuted fractures. It has been reported that every 1 cm of bone defect requires 1 month of regenerate time followed by 1 month of consolidation time.11 The treatment time in acute shortening group was less than in the bone transport group. We realise that the average resection gap in the acute shortening group (4.9 cm) was smaller compared to the bone transport group (5.9 cm). However, when comparing similar bone defects in groups 1 and 2 (see Table 4), the acute shortening group still produced a shorter duration in the frame (see Table 6). This could be because of greater number additional procedures needed to maintain alignment and achieve union.
Conclusion On the basis of our results, we recommend that where feasible, acute shortening is preferable to bone transport because of the shorter treatment time and lesser procedures needed to union. In some circumstances however, this may not be possible, for example in the presence of scarredoedematous soft tissue, presence of an intramedullary nail or a large bone defect of the order of 6 cm. In any individual case however, the true limitation to acute shortening is the blood supply to the foot. In large defects of greater than 6 cm, acute shortening to reduce the gap and bone transport can be performed simultaneously. Where the bone transport technique is used, we now routinely bone graft the docking site. Also, we recommend that in high energy comminuted fractures with or without an open wound, closed reamed intramedullary nailing should be undertaken with caution particularly in patients with a narrow intramedullary canal.
668
References 1. Adams CI, Keating JE, Court-Brown CM. Cigarette smoking and open tibial fractures. Injury 2001;32(1):61—5. 2. Cattaneo R, Catagni M, Johnson EE. The treatment of infected non-unions and segmentat defects of the tibia by the method of Ilizarov. Clin Orthop 1992;280:143—52. 3. Cierny G, Zorn KE. Segmental tibial defects: Comparing conventional and Ilizarov methodologies. Clin Orthop 1994;301:118—23. 4. Dagher F, Roukoz S. Compound tibial fractures with bone loss treated by the Ilizarov technique. JBJS 1991;73-B:316—21. 5. Dendrinos GK, Kontos S, Lyritsis E. Use of Ilizarov technique for treatment of non-union of the tibia associated with infection. JBJS 1995;77-A:835. 6. Gustilo RB, Anderson JT. The prevention of infection in the treatment of 1025 open fractures of long bones. JBJS 1976;58-A:453. 7. Leunig M, Hertel R. Thermal necrosis after tibial reaming for intramedullary nail fixation. A report of three cases. JBJS 1996;78(4):584—7. 8. Maini L, Chadha M, Vishwanath J, et al. The Ilizarov method in infected non-unions of fractures. Injury 2000;31(7):509—17.
J. Mahaluxmivala et al.
9. Marsh JL, Prokuski L, Biermann JS. Chronic infected tibial non-unions with bone loss: Conventional techniques versus bone transport. Clin Orthop 1994;301:139—46. 10. Oschner PE, Baumgart F, Kohler G. Heat induced segmental necrosis after reaming of one humeral and two tibial fractures in narrow medullary canal. Injury 1998;29(Suppl. 2): 1—10. 11. Paley D, Catagni MA, Argnani F, et al. Ilizarov of tibial non-unions with bone loss. Clin Orthop 1989;241:146—65. 12. Paley D, Maar DC. Ilizarov bone transport treatments for tibial defects. J Orthop Trauma 2000;14(2):76—85. 13. Pearson RL, Perry CR. The Ilizarov technique in the treatment of infected tibial non-unions. Orthop Rev 1989;18:609— 13. 14. Schmitz MA, Finnegan M, Natarajan R, Champine J. Effect of smoking on tibial shaft fracture healing. Clin Orthop 1999;365:184—200. 15. Song HR, Cho SH, Koo KH, et al. Tibial bone defects treated by internal bone transport using the Ilizarov method. Int Orthop 1998;22(5):293—7. 16. Williams MO. Long-term cost comparison of major limb salvage using the Ilizarov method versus amputation. Clin Orthop 1994;301:1506.
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Ilizarov external fixator: acute shortening and lengthening versus bone transport in the management of tibial non-unions J. Mahaluxmivala, R. Nadarajah *, P.W. Allen, R.A. Hill Limb Reconstruction Unit, Princess Alexandra Hospital, UK Accepted 21 October 2004
KEYWORDS Ilizarov; Circular frames; External fixator; Acute shortening; Bone transport; Fractures; Tibial; Non-union; Infection; Deformity
Summary Eighteen patients with tibial shaft non-unions were treated by the Ilizarov method between March 1995 and September 2001 by the senior author. Three subgroups of six patients each were treated by either acute shortening and lengthening, bone transport or simple stabilisation with a frame. All aspects of nonunion, infection, shortening, deformity and bone loss were addressed by using Ilizarov principles. There were 10 cases of infected non-unions in the entire series. Bone resection in the shortening group was between 3 and 6 cm (median 4.6) compared to 3—7.5 cm (median 5.9) in the bone transport group. Union was achieved in all the patients with the average time to union at 12.1 months, 17.2 months and 8.0 months, respectively. The bone transport group required additional bone grafting in five patients (83.3%) prior to union compared to one (16.7%) in the acute shortening group. # 2004 Elsevier Ltd. All rights reserved.
Introduction Surgical reconstruction of tibial non-unions with or without associated infection can be a great challenge for the orthopaedic surgeon. These nonunions are usually the result of high-energy trauma accompanied by extensive soft tissue damage at the time of initial injury. Bone defects can result from these injuries primarily or secondarily from the subsequent debridement for contamination or infection. In the long term, there may be problems * Corresponding author. Present address: 20, Britten Court, Abbey Lane, Stratford, London El 5 2RS, UK. Tel.: +44 208 519 5519; fax: +44 208 519 5520. E-mail address: [email protected] (R. Nadarajah).
of deformity, leg length discrepancy, pseudoarthrosis and soft tissue healing. Limb shortening as a method of treatment has been to shown to be undesirable.16 We assessed two methods of treating tibial nonunions with the llizarov technique. The purpose of this study was to assess and compare acute shortening and lengthening versus bone transport, principally looking into the duration of treatment and requirement for bone grafting at the resected non-union site.
Material and methods This study was based on a tertiary referral of 18 patients to our Limb Reconstruction clinic between
0020–1383/$ — see front matter # 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2004.10.027
Ilizarov external fixator: acute shortening and lengthening versus bone transport
663
Table 1 Patient demographics Age
Sex
Type of accident
Open fracture G&A type
Previous surgery (number)
Time to presentation (months)
Infection
Smoker
1 2 3 4 5 6
26 37 54 38 28 36
M M M M M M
RTA RTA RTA RTA RTA RTA
Yes, Yes, No Yes, Yes, No
Yes Yes Yes Yes Yes Yes
(3) (3) (2) (3) (3) (l)
27 37 14 10 10 7
No Yes No No Yes No
No Yes Yes Yes Yes No
7 8 9 10 11 12
31 44 38 52 42 28
M M F M M M
RTA Fail Sports Sports Sports Sports
Yes, 3B Yes, 3A No Yes, 3B No No
Yes Yes Yes Yes Yes Yes
(2) (2) (l) (2) (4) (l)
6 18 6 11 11 8
Yes Yes Yes No Yes Yes
No Yes Yes No No Yes
SFS 13 14 15 16 17 18
28 56 63 55 32 25
M M M F M M
Sports RTA Sports Fall Fall Sports
Yes, 3A Yes, 3B Yes, 3B No No No
Yes Yes Yes Yes Yes No
(l) (2) (1) (l) (1)
3 6 7 17 1 10
Yes Yes Yes Yes Yes Yes
Yes No No No No No
Patient/ group AS
3A 3B 3B 3B
BT
AS: acute shortening, BT: bone transport, SFS: simple frame stabilisation, RTA: road traffic accident, G&A: Gustillo and Anderson classification.
March 1995 and September 2001 (Table 1). There were 2 female and 16 male patients, ranging in age from 26 to 63 years (mean 39.6 years). At presentation, a full history was obtained which included details of the initial injury and previous surgical interventions. On examination, the presence of shortening, deformity, neurovascular deficiency and condition of soft tissue was documented. Delayed union was defined as little or no radiographic evidence of union, 3—6 months following an injury with instability in the fracture site necessitating a change in treatment. Failure of fracture consolidation 6 months after injury was considered a non-union. In 16 patients, there was established non-union on presentation to our clinic, however, in two patients the circular frame was applied within 6 weeks of the initial injury as there were no signs of healing. In these two patients, we anticipated that as a result of the extensive soft tissue stripping and the severity of the fracture communition, non-union would follow. Radiological evaluation of the fracture pattern and deformity was based on Paley’s classification11 (Table 2). Patients were further classified as having an infected non-union if there was a discharging sinus, a positive swab or tissue culture and radiological evidence of infection. All 18 patients were informed about the approximate duration of treat-
ment and the associated complications prior to reconstructive surgery. The patients were divided into three groups. Patients in groups 1 and 2 had tibial segmental defects of more than l cm; group 1 underwent acute shortening and lengthening, whereas group 2 had bone transport. Patients were allocated to these two groups pre-operatively by the senior author (RAH) as they presented to our unit and was independent of the intended amount of bony resection. A third group without segmental defect (
Paley’s classification
Paley’s classification
Group 1
Group 2
Group 3
A2.1 A2.2 Bl B3
0 0 2 4
0 0 2 4
3 3 0 0
Type A: non-unions with less than l cm bone loss; Al: mobile non-union, A2: stiff non-union (A2.1 non associated deformity, A2.2: associated deformity). Type B: non-unions with greater than l cm bone loss; Bl: bony defect with no shortening, B2: shortening with no bony defect, B3: bony defect with shortening.
664
J. Mahaluxmivala et al.
Figure 2 Bone defect in a patient in the bone transport group. The intact fibular aids in maintaining alignment.
Figure 1 Acute shortening after thorough debridement and fibular osteotomy. Proximal corticotomy has been performed.
ment, reaming of the infected medullary canal and resection of infected or non-viable bone was performed so as to obtain healthy bleeding bone on either side of the non-union. Patients in group 1 had a transverse incision at the fracture site so as to facilitate skin closure after acute shortening. These patients also had a fibular osteotomy, which allowed acute compression (see Fig. 1). The corticotomy for lengthening was performed at the proximal tibia at approximately 12 cm from the joint line so as to facilitate an adequate stump if an amputation was required. This corticotomy was carried out percutaneously using a 4 mm drill bit and an osteotome. A complete corticotomy was confirmed clinically and radiologically at the time of surgery. Patients in group 2 did not need a fibular osteotomy as length was maintained but a corticotomy to allow bone transport was performed in a similar manner as described above (see Fig. 2). A standard llizarov frame was applied predominantly with 1.8 mm wire fixation although half pins
were used in some cases. In group 1 (acute shortening), the frame was constructed to permit compression and distraction of the non-union site. In group 2 (bone transport), external transport was used with the transport segment held with one or two wires and a half pin. In group 3, the fracture site was not opened nor was a corticotomy performed but the frame was constructed to permit compression and distraction at the fracture site. Patients with very distal fractures had the foot included in the frame for stability. Three patients had additional soft tissue procedures to aid healing and coverage. Two patients underwent split skin grafting at the time of frame application, whereas one patient in the acute shortening group had a free flap applied prior to frame application. In the post operative period, joint motion and weight bearing exercises were permitted as pain allowed. As a protocol in our unit, the use of nonsteroidal anti-inflammatory drugs is strictly prohibited at all stages of reconstructive surgery. In all groups, weight-bearing mobilisation was actively encouraged. In the acute shortening group (group 1), ankle splintage was needed in those patients without a foot frame until limb length was restored. Distraction at an initial rate of l mm a day in four increments was commenced between day 5 and 7. Pin site care and hygiene was taught to all patients. On discharge, all patients were seen on a regular
Ilizarov external fixator: acute shortening and lengthening versus bone transport
Figure 4
665
Persistent non-union at the docking site.
Figure 3 Union at the fracture site seen in a patient in the acute shortening group prior to frame removal.
basis in the out patients department, where further clinical and radiographic assessment of their progress was made. The initial rate of distraction was altered based on the radiological appearance of the regenerate. In group 1 (acute shortening), compression at the fracture site was maintained till union (see Fig. 3). Distraction at the corticotomy site was continued until limb length equality was achieved. Poor consolidation of the regenerate was treated by encouraging weight bearing and alternate compression—distraction (Concertina technique). In group 2 (bone transport), in addition to assessing the regenerate, radiological assessment of alignment is undertaken to ensure adequate docking. If necessary, the frame was adjusted under general anaesthetic to correct malalignment. After successful docking, if there was no radiological evidence of union at 6 weeks (see Fig. 4), iliac crest graft was applied to the docking site after excision of any interposed soft tissue (see Fig. 5). In group 3 (frame stabilisation), alignment was corrected acutely at the time of frame application. In hypertrophic or stiff non-unions, the non-union
Figure 5 Bone graft applied at the docking site to aid union (same patient in Fig. 4).
666
J. Mahaluxmivala et al.
was initially distracted whereas with atrophic or lax non-unions, compression was initially applied. If the non-union was slow to heal, alternate compression— distraction was used. In all patients, the frame was retained until adequate consolidation of the regenerate as well fracture union is seen. Our criteria for radiological healing is the presence of bony consolidation in three out of four cortices. When this is achieved, the patient is admitted for examination under anaesthetic of the fracture and regenerate site under fluoroscopy guidance. If satisfactory, the frame is removed and the limb is left unsupported with instructions to the patients to gradually mobilise to full weight bearing with the aid of crutches. Plaster of Paris immobilisation was only used to correct residual equinus deformities.
Results The mean age of patients was 39.6 years with 2 female and 16 male patients. In all three groups, patients were similar for age, pre-injury health status including cigarette smoking. Nearly all patients had high velocity trauma, with 10 being involved in a road traffic accident. Ten patients in the entire series (five in group 1, four in group 2 and one in group 3) had open fractures in the initial injury with the majority being grade 3B according to the Gustillo and Anderson classification.6 Most patients had at least two previous operative interventions prior to referral to our clinic. In group 2, five patients (83.6%) had locked reamed intramedullary nailing as compared to two patients (33.3%) in group 1 (Table 3). The mean time to Ilizarov surgery in each group from the time of initial injury was 16.2, 12.0 and 6.8 months, respectively. Infection was noted in four patients in group 1, five patients in group 2 and one patient in group 3. At the time of surgery, the decision regarding amount of bone resection was based on the presence of healthy bleeding bone ends. The mean resection being 4.6 cm in group 1 and 5.9 cm in group 2 (Table 4). Table 3 Previous treatments IM nailing External fixator Others
Group 1
Group 2
Group 3
1 5
5 I
0 4
Bone grafting (1)
Exchange Nail (1)
Plating (1)
Exchange nail (1)
Plaster of Paris (1)
Table 4
Amount of bone resection
Patient
Group 1 (cm)
1 2 3 4 5 6 Range Mean
Table 5
Group 2 (cm)
3 4 4.5 5 5 6
3 5 6 7 7 7.5
3—6 4.6
3—7.5 5.9
Additional procedures
Procedures
Group 1
Group 2
Group 3
Adjustment of frame Insertion of wires Bone grafting required Bone graft at docking site Bone graft at regenerate site
0 0 1 0
2 2 5 4
o 0 0 0
1
1
0
Additional procedures were required in two patients in the acute shortening group and all six patients in the bone transport group. These included adjustment of frame and/or insertion of wires to realign the transport segment and also, bone grafting at the docking or regenerate site (Table 5). It was noted that patients in the bone transport group had more procedures done especially bone grafting at the docking site. All 18 patients had at least one pin site infection, but only four patients required hospital admission for intravenous antibiotic therapy. At the time of frame removal, complete eradication of infection was seen in all patients. No patient was left with a residual limb shortening of more than 2 cm as assessed by clinical examination with blocks. Five patients (90%) in the acute shortening group and five patients (90%) in the bone transport group had equal leg length or a discrepancy of less than 1 cm. Union was achieved in all patients, with the average time to frame removal being 12.1, 17.2 and 8.0 months, respectively in all three groups (Table 6). All patients were followed up for at least Table 6
Time to frame removal
Patient
Group 1 (months)
Group 2 (months)
Group 3 (months)
1 2 3 4 5 6
11 9 19 8 12 13.6
12 7 19 24 14 24
3 10 11 6 6.8 11.2
Mean
12.1
17.2
8.0
Ilizarov external fixator: acute shortening and lengthening versus bone transport
18 months after the removal of their Ilizarov frame. No recurrence of infection was seen in any group.
Discussion The Ilizarov method is well established in the treatment of high energy tibial non-unions.4,5,13,15 It is able to address the problems of an avascular segment, infection, deformity and limb length discrepancy. Several authors have compared bone transport with other conventional techniques.3,9 In this study, we compared acute shortening and then subsequent lengthening against bone transport in the treatment of tibial non-unions. The simple stabilisation group was included for comparison. Patients in each group were similar for age and cigarette smoking, which are well documented aetiologies of non-unions.1,14 In this series, we noted that risk factors for extensive bone resection was high energy comminuted fractures treated by locked reamed intramedullary nailing, particularly when the fracture site was opened to facilitate the nailing. There were two cases of thermal necrosis due to jammed reamers that resulted in an avascular segment. Both these patients had extensive intramedullary infection. This problem has been documented in other series.7,10 More procedures were necessary in the bone transport group mainly to correct alignment to ensure accurate docking and bone grafting at the docking site. Malalignment at the docking site has been well documented by many other series looking at bone transport in Ilizarov surgery.12 Additional procedures were not required in the acute shortening group to maintain alignment as the fracture site is acutely compressed. In the acute shortening group, fracture site union was achieved without any additional intervention. However, in the bone transport group 4 patients required bone grafting at the docking site before solid bony union was achieved. It is thought that fibrous capping of the fracture ends as the transport segment descends may be a cause for this delayed union.12 Bone grafting at the docking site has been recommended by a number of authors2,3,9,12 and in our unit, we now routinely perform this. In the acute shortening group, no further surgical intervention was required to achieve union. The number of procedures in the acute shortening group was therefore, similar to the simple frame stabilisation. There was no difference in the consolidation pattern in our two main groups (group 1 and 2). One patient in each group (1 and 2), had bone grafting at the regenerate site to allow for complete healing.
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Using Paley’s bone result evaluation system, an excellent bone result was achieved in all patients in all three groups.11 This meant that union was achieved with eradication of infection, no residual deformity of more than 58 in any plane, no residual limb length discrepancy of more than 2.5 cm and a bone union wide enough not to require long term bracing or protection. It is interesting to note however, that if the ASAMI (Association for the Study and Application of the Method of Ilizarov) classification is used,8 four patients in the bone transport group and one in the acute shortening group would have a poor bone result merely due to bone graft usage. In our three groups, the average time in the frame was 12.1, 17.2 and 8.0 months (Table 6). In the frame stabilisation group (comparison group), there was no bone loss however the fractures were still high energy comminuted fractures. It has been reported that every 1 cm of bone defect requires 1 month of regenerate time followed by 1 month of consolidation time.11 The treatment time in acute shortening group was less than in the bone transport group. We realise that the average resection gap in the acute shortening group (4.9 cm) was smaller compared to the bone transport group (5.9 cm). However, when comparing similar bone defects in groups 1 and 2 (see Table 4), the acute shortening group still produced a shorter duration in the frame (see Table 6). This could be because of greater number additional procedures needed to maintain alignment and achieve union.
Conclusion On the basis of our results, we recommend that where feasible, acute shortening is preferable to bone transport because of the shorter treatment time and lesser procedures needed to union. In some circumstances however, this may not be possible, for example in the presence of scarredoedematous soft tissue, presence of an intramedullary nail or a large bone defect of the order of 6 cm. In any individual case however, the true limitation to acute shortening is the blood supply to the foot. In large defects of greater than 6 cm, acute shortening to reduce the gap and bone transport can be performed simultaneously. Where the bone transport technique is used, we now routinely bone graft the docking site. Also, we recommend that in high energy comminuted fractures with or without an open wound, closed reamed intramedullary nailing should be undertaken with caution particularly in patients with a narrow intramedullary canal.
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References 1. Adams CI, Keating JE, Court-Brown CM. Cigarette smoking and open tibial fractures. Injury 2001;32(1):61—5. 2. Cattaneo R, Catagni M, Johnson EE. The treatment of infected non-unions and segmentat defects of the tibia by the method of Ilizarov. Clin Orthop 1992;280:143—52. 3. Cierny G, Zorn KE. Segmental tibial defects: Comparing conventional and Ilizarov methodologies. Clin Orthop 1994;301:118—23. 4. Dagher F, Roukoz S. Compound tibial fractures with bone loss treated by the Ilizarov technique. JBJS 1991;73-B:316—21. 5. Dendrinos GK, Kontos S, Lyritsis E. Use of Ilizarov technique for treatment of non-union of the tibia associated with infection. JBJS 1995;77-A:835. 6. Gustilo RB, Anderson JT. The prevention of infection in the treatment of 1025 open fractures of long bones. JBJS 1976;58-A:453. 7. Leunig M, Hertel R. Thermal necrosis after tibial reaming for intramedullary nail fixation. A report of three cases. JBJS 1996;78(4):584—7. 8. Maini L, Chadha M, Vishwanath J, et al. The Ilizarov method in infected non-unions of fractures. Injury 2000;31(7):509—17.
J. Mahaluxmivala et al.
9. Marsh JL, Prokuski L, Biermann JS. Chronic infected tibial non-unions with bone loss: Conventional techniques versus bone transport. Clin Orthop 1994;301:139—46. 10. Oschner PE, Baumgart F, Kohler G. Heat induced segmental necrosis after reaming of one humeral and two tibial fractures in narrow medullary canal. Injury 1998;29(Suppl. 2): 1—10. 11. Paley D, Catagni MA, Argnani F, et al. Ilizarov of tibial non-unions with bone loss. Clin Orthop 1989;241:146—65. 12. Paley D, Maar DC. Ilizarov bone transport treatments for tibial defects. J Orthop Trauma 2000;14(2):76—85. 13. Pearson RL, Perry CR. The Ilizarov technique in the treatment of infected tibial non-unions. Orthop Rev 1989;18:609— 13. 14. Schmitz MA, Finnegan M, Natarajan R, Champine J. Effect of smoking on tibial shaft fracture healing. Clin Orthop 1999;365:184—200. 15. Song HR, Cho SH, Koo KH, et al. Tibial bone defects treated by internal bone transport using the Ilizarov method. Int Orthop 1998;22(5):293—7. 16. Williams MO. Long-term cost comparison of major limb salvage using the Ilizarov method versus amputation. Clin Orthop 1994;301:1506.