Javascript not enabled
TraumaFocus On...

Management of traumatic bone loss

N. Hossain, M. Barry
AttachmentSize
PDF icon FocusOn_MassiveBoneLoss.pdf177.53 KB

 

Introduction

Historically, limbs that sustained traumatic bone loss with associated soft-tissue injury were deemed unsalvageable and treated primarily by amputation. With current soft-tissue reconstruction techniques, it is now possible to obtain cover of large defects. However, what remains a challenge is the subsequent reconstruction of the bone defect while maintaining limb alignment and length.

Limb salvage procedures in this patient population are challenging, both for surgeon and patient, with no guarantee of a satisfactory outcome.  In this review, we attempt to provide guidelines on how to approach the management of these injuries in the acute setting.

Classification of defects

Traumatic bone loss is a spectrum, from a small butterfly fragment through to complete loss of large sections of bone. There is no widely recognised classification of traumatic bone loss, either as the result of the injury or subsequent debridement. Perhaps the most commonly employed classification system for open fractures is that described by Gustilo and Anderson1 and then modified by Gustilo, Mendoza and Williams.2 Open fractures are classified according to the size and extent of the soft-tissue injury and the degree of contamination; bone loss is not part of this classification.

Robinson et al attempted to classify bone loss in tibial fractures (Table I) and this could potentially be applied to all long bone diaphyseal fractures.3

 

Epidemiology

Significant traumatic bone loss is uncommon. As the tibia has a subcutaneous border its diaphysis is the most frequent area of bone involved. These injuries typically occur in young adults and the associated soft-tissue loss is usually Gustilo & Anderson grade III.4 When the fracture involves the metaphyseal and articular surface, the injury tends to be more severe because of the higher degree of energy transfer at the time of injury.

Management

Initial Management

As with all fractures, the initial management should follow standard trauma resuscitation protocols. Once the primary survey is complete and the patient adequately resuscitated, the secondary survey is performed and an assessment is made of the injured limb. With severe limb trauma, a number of scoring systems  have been described including the Mangled Extremity Severity Score (MESS)5, the Limb Salvage Index (LSI)6 and the Predictive Salvage Index (PSI.)7 These scoring systems are to assist in the decision-making process as to whether the traumatised limb should undergo either primary amputation or salvage. Unfortunately, a recent study 8 was unable to validate the clinical usefulness of any of the extremity injury scores and, as a result, scoring systems in this setting should be applied with caution. Large amounts of muscle loss, massive contamination and unreconstructable vascular injuries are probably indications for immediate amputation. In the past, the presence of an insensate foot was also a strong indication for amputation although not all authors would necessarily agree.9

Once a decision has been made to attempt to salvage the limb, the soft tissues and bone need thorough debridement and the fracture must be stabilised. The initial debridement may result in a further loss of soft tissue and/or bone when grossly contaminated and devitalised tissue is removed. Skeletal stabilisation is required to restore alignment, eliminate gross movement at the fracture site, limit further soft-tissue damage and reduce bacterial contamination.  Because of the unpredictable nature of these injuries, the method of skeletal stabilisation cannot be prescribed and an individualised approach is required. In the majority of cases with significant bone and soft-tissue loss, a temporary external fixator will be used to provide initial stabilisation. With limited bone loss, for example when a simple of wedge of bone has been lost, then immediate and definitive internal fixation may be used if the soft tissues allow.

Whatever method is selected to stabilise the bone, consideration should be given as to whether the overall length of the bone should be maintained or whether the defect should be reduced by an acute shortening procedure. This answer will depend on the length of the bone defect and the size and position of the soft-tissue loss. The amount of acute shortening that can be tolerated in the adult tibia is approximately 5 cm.4 Acute shortening of more than this can result in distal complications such as oedema and venous occlusion 4. As an alternative, it is possible to combine an element of acute shortening with more gradual shortening to close larger defects.4 The advantage of acute shortening is that it may enable closure of a wound defect without the need for complex soft-tissue reconstruction. However, the obvious disadvantage is that a subsequent lengthening may subsequently be required.

If there is significant soft tissue loss after the initial stabilisation, early consultation with a plastic surgeon is advised. Definitive soft-tissue cover with skeletal stabilisation should ideally be achieved within 72 hours and should not be left for more than one week.10

Definitive Management

The ultimate goal in the management of all fractures with bone loss is solid bone union, acceptable alignment, equal limb length and restoration of function.

If initial stabilisation has been with use of a temporary external fixator, and if the general condition of the patient and the local soft tissues allow, the surgeon should consider conversion to an alternative, definitive mode of fracture stabilisation within 72 hours.10 These include:

Plate fixation

With the advent of minimally invasive techniques and the use of locking plates, a fracture can be stabilised without significant further soft-tissue stripping. Wedge bone loss or short segments of complete bone loss can be bridged, with subsequent bone grafting of defects as required.

Intramedullary Fixation

Most long-bone diaphyseal fractures of the femur and tibia can be treated with an intramedullary nail. This technique is also particularly useful for segmental fractures. An intramedullary nail should provide good skeletal stability, and enables early joint movement and improved functional recovery.

In cases with minor bone loss of less than 2.5 cm, an intramedullary nail to maintain the original bone length may be used. After this, delayed bone grafting or exchange nailing may sometimes be needed in order to achieve bony union. The femur has a good soft-tissue envelope and, therefore, may tolerate larger defects than the tibia.

With more significant bone loss measuring over 2.5 cm, an intramedullary nail alone is unlikely to be sufficient in the long term, and so a number of strategies may need to be considered, as follows:

a) Acute shortening with intramedullary fixation, and subsequent lengthening using an external fixator.11,12

b) Acute shortening with intramedullary fixation and subsequent lengthening with a distractable nail.13

c) Bone transport over an intramedullary nail.14

c. External fixation

The use of circular external fixators in the management of bone loss is well established.15,16  The technique allows for the simultaneous treatment of bone loss, infection, non-union and deformity.

The results of initial management of traumatic bone loss can result in two scenarios:

1) Maintenance of overall length of the bone, with a defect that is typically > 5 cm in length.

Bone transport will be needed to manage this defect.17 This is a process in which the bone is divided proximally in order to produce a short segment, typically 5 to 10 cm in length. This segment is gradually moved distally with the external fixator, to eventually come in contact with the distal bone. The trailing defect fills with regenerate bone. At the time of distal bone contact (“docking”), the site may be explored and bone grafted if needed.18

2) An acutely shortened bone and no bony defect.

Shortening in this situation is typically < 5 cm. The restoration in length may be with an external fixator alone in conjunction with an intramedullary nail. The local soft-tissue environment where the bone has been lost will usually be traumatised and there may be local soft-tissue reconstruction required. This environment is not conducive to bone regeneration so an alternative site should be used with a better soft-tissue envelope. Consequently, the lengthening point is generally at a different point in the bone from the original fracture.

Alternative methods to manage bone loss

Although the use of an external fixator and internal fixation is the commonest method to manage traumatic bone loss, other surgical techniques can be used. These may be as follows:

Vascularised free fibular graft

The use of a vascularised free fibular graft to bridge a bone defect is a technically demanding procedure that requires microvascular surgical techniques.19,20 This method should be considered when there is a bone defect  > 12 cm in size.21 Donor site morbidity can be problematic, although it may be possible to use the ipsilateral fibula when there is adjacent tibial bone loss.22,23

Allografts

Insertion of allograft into a defect is an attractive proposition as it avoids problems of donor-site morbidity and prolonged external fixation during either limb lengthening or bone transport.24,25 It is, however, associated with an lengthy recovery period to allow the allograft to incorporate into the host skeleton and complications including fracture 26 and non union 27,28

Conclusion

Fortunately, extensive traumatic bone loss is an uncommon occurrence and, as a result, patients with major bone loss are perhaps best managed at larger trauma units. The transfer of a patient after adequate resuscitation should occur at an early stage. Significant bone loss will almost certainly be associated with extensive soft-tissue trauma, so a multidisciplinary approach between orthopaedic and plastic surgeons is essential. Complex soft-tissue reconstruction procedures may be required although with the judicious use of acute skeletal shortening, less complex techniques, or even primary wound closure, may be possible.

The orthopaedic approach to traumatic bone loss needs to be a flexible one. Treatment must take account of the amount of bone loss, any associated soft-tissue injuries, and the general health and wishes of the patient. Amputation must always be considered as an option, however difficult a decision that may be. In general, the management of the bone loss will require prolonged treatment times, especially with complex techniques such as bone transport. The patient must understand from an early stage that treatment that is likely to be long and difficult, the goal being solid bone union, acceptable mechanical alignment, equal limb length and acceptable restoration of function.

References

1. Gustilo RB, Anderson JT.  Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: retrospective and prospective analyses. J Bone Joint Surg Am 1976;58:453-8.
2. Gustilo RB, Mendoza RM, Williams DN. Problems in the management of type III (severe) open fractures: a new classification of type III open fractures. J Trauma 1984;24:742-6.
3. Robinson CJ, McLauchlan G, Christie J, McQueen MM, Court-Brown CM. Tibial fractures with bone loss treated by primary reamed intramedullary nailing. J Bone Joint Surg Br 1995;77-B:906-13.
4. El-Rosasy M.  Acute shortening and re-lengthening in the management of bone and soft-tissue loss in complicated fractures of the tibia. J Bone Joint Surg (Br) 2007;89-B:80-8.
5. Johansen K, Daines M, Howey T, Helfet D, Hansen ST Jr. Objective criteria accurately predict amputation following lower extremity trauma. J Trauma. 1990;30:568-73.
6. Russell WL, Sailors DM, Whittle TB, Fisher DF Jr, Burns RP. Limb salvage versus traumatic amputation. A decision based on a seven-part predictive index. Ann Surg. 1991;213:473-81.
7. Howe HR Jr, Poole GV, Hansen KJ, Clark T, Plonk GW, Koman LA, Pennell T. Salvage of lower extremities following combined orthopedic and vascular trauma.  A predictive salvage index.  Am Surg. 1987;53:205-8
8. Bosse MJ, MacKenzie EJ, Kellam JF, Burgess AR, Webb LX, Swiontkowski MF, Sanders RW, Jones AL, McAndrew MP, Patterson BM, McCarthy ML, Cyril J. A prospective evaluation of the clinical utility of the lower-extremity injury-severity scores.  J Bone Joint Surg Am 2001;83A:3-14.
9. Bosse MJ. McCarthy ML. Jones AL. Webb LX. Sims SH. Sanders RW. MacKenzie EJ. Lower Extremity Assessment Project (LEAP) Study Group. The insensate foot following severe lower extremity trauma: an indication for amputation? J Bone Joint Surg Am 2005;87A:2601-8.
10. BOAST 4: The management of severe open lower limb fractures. BOA/BAPRAS Standards for the management of open fractures of the lower limb. October 2009. http://www.boa.ac.uk/en/publications/boast/
11. Simpson AH. Cole AS. Kenwright J. Leg lengthening over an intramedullary nail. J Bone Joint Surg Br 1999;81B:1041-5.
12. Paley D. Herzenberg JE. Paremain G. Bhave A. Femoral lengthening over an intramedullary nail. A matched-case comparison with Ilizarov femoral lengthening. J Bone Joint Surg (Am) 1997;79A:1464-80.
13. Cole JD. Justin D. Kasparis T. DeVlught D. Knobloch C. The intramedullary skeletal kinetic distractor (ISKD): first clinical results of a new intramedullary nail for lengthening of the femur and tibia. Injury 2001:32 Suppl 4:129-39.
14. Oh CW, Song HR, Roh JY, Oh JK, Min WK, Kyung HS, Kim JW, Kim PT, Ihn JC. Bone transport over an intramedullary nail for reconstruction of long bone defects in tibia.Arch Orthop & Tr Surg 2008;128:801-8.
15. Tsuchiya H, Tomita K. Distraction osteogenesis for treatment of bone loss in the lower extremity. J Orthop Sci 2003;8:116-24.
16.  Atesalp AS, Basbozkurt M, Erler E, Sehirlioğlu A, Tunay S, Solakoğlu C, Gür E. Treatment of tibial bone defects with the Ilizarov circular external fixator in high-velocity gunshot wounds.  Int Orthop 1998;22:343-47.
17. Abdel-Aal AM. Ilizarov bone transport for massive tibial bone defects. Orthop. 2006;29:70-4.
18.  Mahaluxmivala J, Nadarajah R, Allen P, Hill R. Ilizarov external fixator: acute shortening and lengthening versus bone transport in the management of tibial non-unions.  Injury 2005;36:662-8.
19. Han CS, Wood MB, Bishop AT, Cooney WP. Vascularized bone transfer. J Bone Joint Surg (Am) 1992;74-A:1441-9.
20. Chang MC, Lo WH, Chen CM, Chen TH. Treatment of large skeletal defects in the lower extremities using double-strut, free vascularized fibular bone grafting. Orthop 1999;22:739-44.
21. El-Gammal TA, Shiha AE, El-Deen MA, El-Sayed A, Kotb MM, Addosooki AI, Ragheb YF, Saleh WR. Management of traumatic tibial defects using free vascularized fibula or Ilizarov bone transport: a comparative study. Microsurgery 2008;28:339-46.
22. Bodde EW, de Visser E, Duysens JE, Hartman EH. Donor-site morbidity after free vascularized autogenous fibular transfer: subjective and quantitative analyses.Plastic & Recon Surg 2003;1112:237-42.
23. Theos C, Koulouvaris P, Kottakis S, Demertzis N. Reconstruction of tibia defects by ipsilateral vascularized fibula transposition. Arch Orthop  & Tr Surg 2008;128:179-84.
24. Jaffe KA, Morris SG, Sorrell RG, Gebhardt MC, Mankin HJ. Massive bone allografts for traumatic skeletal defects. Southern Med J 1991;84:975-82.
25. Salai M, Horoszowski H, Pritsch M, Amit Y. Primary reconstruction of traumatic bony defects using allografts. Arch Orthop & Tr Surg 1999;119:435-39.
26. Berrey BH, Lord CF, Gebhardt MC, Mankin HJ. Fractures of allografts. Frequency, treatment, and end-results. J Bone Joint Surg Am. 1990; 72A:825-833
27. Aro HT, Aho AJ. Clinical use of bone allografts. Ann Med. 1993;25:403-12.
28. Bullens PH, Minderhoud NM, de Waal Malefijt MC, Veth RP, Buma P, Schreuder HW. Survival of massive allografts in segmental oncological bone defect reconstructions. Int Orthop. 2009;33:757-60.