- Email: [email protected]
Osteotomising the fibular free flap: an anatomical perspective
ARTICLE IN PRESS
YBJOM-4692; No. of Pages 2
Available online at www.sciencedirect.com
British Journal of Oral and Maxillofacial Surgery xxx (2015) xxx–xxx
Short communication
Osteotomising the fibular free flap: an anatomical perspective A.M. Fry a,∗ , Dave Laugharne b , Keith Jones b a
Department of Oral and Maxillofacial Surgery, Sheffield, Teaching Hospitals NHS Foundation Trust, Charles Clifford Dental Hospital, 76 Wellesley Rd, Sheffield, South Yorkshire S10 2SZ b Department of Oral and Maxillofacial Surgery, Royal Derby Hospital, Uttoxeter New Road, Derby DE22 3NE Accepted 9 November 2015
Abstract Multiple osteotomies with the help of 3-dimensional planning have improved the accuracy of reconstructions, and the reliability and versatility of the fibular free flap is well recognised. To investigate the periosteal blood supply of the fibula and to define safe limits for the size of bony segments, we performed a cadaveric study on 10 fresh frozen lower limbs using a combined barium latex mixture. We modelled cuts at intervals of 1.0, 1.5, and 2.0 cm, and assessed the number of periosteal vessels. After virtual dissections using DICOM data obtained from high-resolution computed tomograms (CT), on average we found 12.8 periosteal branches, with a mean (SD) distance between them of 1.36 (0.18) cm. In 34.9% of the 1 cm segments there were no visible periosteal vessels. Vascularity seemed to be more reliable in longer segments, with 83.4% of those 1.5 cm long, and 94% of those of over 2 cm containing at least one branch. © 2015 Published by Elsevier Ltd. on behalf of The British Association of Oral and Maxillofacial Surgeons.
Keywords: Reconstruction; Anatomy; Fibular; Oncology
Introduction The fibular flap remains a popular and reliable choice for microvascular reconstruction of mandibular segmental defects.1 Better understanding of the anatomy has led to innovations including “double-barrelling”, which increases the height of the bone to improve oral rehabilitation, and “double-paddling” for through-and-through defects.2,3 The use of multiple cuts to contour and shape as required is well established, but there is some uncertainty about how close together they can be without compromising the blood supply to the resultant bony segment. Often, in an attempt to reduce the number of cuts, the bony reconstruction can be quite angular or square in appearance. ∗
Corresponding author. E-mail address: [email protected] (A.M. Fry).
To be able to recommend a safe distance between cuts, we did a detailed anatomical study of the vasculature of the lower limb to find out how many fibular periosteal vessels were present in segments of different lengths.
Method We perfused 10 fresh frozen cadaveric lower limbs with a 30:70 barium latex mixture through the femoral artery. The mixture, which combines the radiopaque qualities of barium with the colour and setting properties of latex to give excellent visualisation of the vessels, allows for subsequent dissection.4 After leaving the limbs on ice for 12 hours, we obtained high-resolution images with an Aquilion 64 slice computed tomographic (CT) scanner 120KVp 300Ma (volume = 0.5/0.3 mm with bone and soft tissue reconstructions)
http://dx.doi.org/10.1016/j.bjoms.2015.11.009 0266-4356/© 2015 Published by Elsevier Ltd. on behalf of The British Association of Oral and Maxillofacial Surgeons.
Please cite this article in press as: Fry AM, et al. Osteotomising the fibular free flap: an anatomical perspective. Br J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.bjoms.2015.11.009
YBJOM-4692; No. of Pages 2
2
ARTICLE IN PRESS A.M. Fry et al. / British Journal of Oral and Maxillofacial Surgery xxx (2015) xxx–xxx Table 1 Number (%) of fibular bony segments that contained periosteal vessels. Size of segment (cm)
1.0 1.5 2.0
Periosteal vessels None
1
2 or more
34.9 16.5 6.0
60.9 67.7 57.6
4.2 15.7 36.4
Discussion
Fig. 1. Three-dimensional computed tomogram of lower limb and foot showing the detail achieved by the barium latex technique.
Fig. 2. Three-dimensional computed tomographic reconstruction of a fibula showing the segmental pattern of the periosteal branches of the peroneal artery.
The blood supply to the fibula is from a periosteal and medullary route through nutrient arteries. When the bone is sectioned the blood supply becomes centripetal and is dependent on the periosteal supply.5 Our finding that 65% of the 1 cm segments of bone had one visible periosteal vessel suggests that segments of this length may often be acting as free bone grafts. When the distance between osteotomies was increased to 2.0 cm, the percentage increased to 94%. Segments of less than 2.0 cm should be avoided if vascularity may be compromised, for example, when postoperative radiotherapy is a possibility. However, the transfer of cadaveric findings to the clinical situation has limitations, and it is possible that the bone was viable because of smaller vessels that could not been seen, or were not filled with the contrast medium because of the presence of small clots.
Conflict of Interest We have no conflicts of interest.
(Toshiba America Medical Systems Inc, Tustin, USA). Three-dimensional reconstructions were produced from the DICOM data using an OsiriX viewer (Pixmeo SARL, Bernex, Switzerland), which clearly showed vessels over 0.5 mm in diameter (Fig. 1). After virtual dissection we recorded the position of the periosteal branches of the peroneal artery along the fibula (Fig. 2). We excluded the proximal and distal 6 cm regions of the bones because they are not normally harvested. We modelled osteotomy segments of 1.0, 1.5, and 2.0 cm and counted the number of periosteal branches of the peroneal artery.
Results We found a mean (SD) number of 12.8 (1.82) periosteal branches/fibula with a mean (SD) distance between them of 1.36 (0.18) cm. At least one branch was found in 65.1% of the 1 cm segments, in 83.4% of the 1.5 cm segments, and in 94% of the 2 cm segments (Table 1).
Acknowledgements I would like to acknowledge the generous support of the Derby Radiology department in particular Dr Simon Elliott and the technical assistance of Dr Richard Tunstall Associate Professor of Anatomy.
References 1. Hidalgo DA, Rekow A. A review of 60 consecutive fibula free flap mandible reconstructions. Plast Reconstr Surg 1995;96:585–602. 2. Jones NF, Swartz WM, Mears DC, et al. The “double barrel” free vascularized fibular bone graft. Plast Reconstr Surg 1988;81:378–85. 3. Fry AM, Tunstall R, Laugharne D, et al. The double-paddled osseocutaneous fibular flap—a combined CT and dissection study. Br J Oral Maxillofac Surg 2013;51:e97–8. 4. Sedlmayr JC, Witmer LM. Rapid technique for imaging the blood vascular system using stereoangiography. Anat Rec 2002;267:330–6. 5. Bähr W. Blood supply of small fibula segments: an experimental study on human cadavers. J Craniomaxillofac Surg 1998;26:148–52.
Please cite this article in press as: Fry AM, et al. Osteotomising the fibular free flap: an anatomical perspective. Br J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.bjoms.2015.11.009
YBJOM-4692; No. of Pages 2
Available online at www.sciencedirect.com
British Journal of Oral and Maxillofacial Surgery xxx (2015) xxx–xxx
Short communication
Osteotomising the fibular free flap: an anatomical perspective A.M. Fry a,∗ , Dave Laugharne b , Keith Jones b a
Department of Oral and Maxillofacial Surgery, Sheffield, Teaching Hospitals NHS Foundation Trust, Charles Clifford Dental Hospital, 76 Wellesley Rd, Sheffield, South Yorkshire S10 2SZ b Department of Oral and Maxillofacial Surgery, Royal Derby Hospital, Uttoxeter New Road, Derby DE22 3NE Accepted 9 November 2015
Abstract Multiple osteotomies with the help of 3-dimensional planning have improved the accuracy of reconstructions, and the reliability and versatility of the fibular free flap is well recognised. To investigate the periosteal blood supply of the fibula and to define safe limits for the size of bony segments, we performed a cadaveric study on 10 fresh frozen lower limbs using a combined barium latex mixture. We modelled cuts at intervals of 1.0, 1.5, and 2.0 cm, and assessed the number of periosteal vessels. After virtual dissections using DICOM data obtained from high-resolution computed tomograms (CT), on average we found 12.8 periosteal branches, with a mean (SD) distance between them of 1.36 (0.18) cm. In 34.9% of the 1 cm segments there were no visible periosteal vessels. Vascularity seemed to be more reliable in longer segments, with 83.4% of those 1.5 cm long, and 94% of those of over 2 cm containing at least one branch. © 2015 Published by Elsevier Ltd. on behalf of The British Association of Oral and Maxillofacial Surgeons.
Keywords: Reconstruction; Anatomy; Fibular; Oncology
Introduction The fibular flap remains a popular and reliable choice for microvascular reconstruction of mandibular segmental defects.1 Better understanding of the anatomy has led to innovations including “double-barrelling”, which increases the height of the bone to improve oral rehabilitation, and “double-paddling” for through-and-through defects.2,3 The use of multiple cuts to contour and shape as required is well established, but there is some uncertainty about how close together they can be without compromising the blood supply to the resultant bony segment. Often, in an attempt to reduce the number of cuts, the bony reconstruction can be quite angular or square in appearance. ∗
Corresponding author. E-mail address: [email protected] (A.M. Fry).
To be able to recommend a safe distance between cuts, we did a detailed anatomical study of the vasculature of the lower limb to find out how many fibular periosteal vessels were present in segments of different lengths.
Method We perfused 10 fresh frozen cadaveric lower limbs with a 30:70 barium latex mixture through the femoral artery. The mixture, which combines the radiopaque qualities of barium with the colour and setting properties of latex to give excellent visualisation of the vessels, allows for subsequent dissection.4 After leaving the limbs on ice for 12 hours, we obtained high-resolution images with an Aquilion 64 slice computed tomographic (CT) scanner 120KVp 300Ma (volume = 0.5/0.3 mm with bone and soft tissue reconstructions)
http://dx.doi.org/10.1016/j.bjoms.2015.11.009 0266-4356/© 2015 Published by Elsevier Ltd. on behalf of The British Association of Oral and Maxillofacial Surgeons.
Please cite this article in press as: Fry AM, et al. Osteotomising the fibular free flap: an anatomical perspective. Br J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.bjoms.2015.11.009
YBJOM-4692; No. of Pages 2
2
ARTICLE IN PRESS A.M. Fry et al. / British Journal of Oral and Maxillofacial Surgery xxx (2015) xxx–xxx Table 1 Number (%) of fibular bony segments that contained periosteal vessels. Size of segment (cm)
1.0 1.5 2.0
Periosteal vessels None
1
2 or more
34.9 16.5 6.0
60.9 67.7 57.6
4.2 15.7 36.4
Discussion
Fig. 1. Three-dimensional computed tomogram of lower limb and foot showing the detail achieved by the barium latex technique.
Fig. 2. Three-dimensional computed tomographic reconstruction of a fibula showing the segmental pattern of the periosteal branches of the peroneal artery.
The blood supply to the fibula is from a periosteal and medullary route through nutrient arteries. When the bone is sectioned the blood supply becomes centripetal and is dependent on the periosteal supply.5 Our finding that 65% of the 1 cm segments of bone had one visible periosteal vessel suggests that segments of this length may often be acting as free bone grafts. When the distance between osteotomies was increased to 2.0 cm, the percentage increased to 94%. Segments of less than 2.0 cm should be avoided if vascularity may be compromised, for example, when postoperative radiotherapy is a possibility. However, the transfer of cadaveric findings to the clinical situation has limitations, and it is possible that the bone was viable because of smaller vessels that could not been seen, or were not filled with the contrast medium because of the presence of small clots.
Conflict of Interest We have no conflicts of interest.
(Toshiba America Medical Systems Inc, Tustin, USA). Three-dimensional reconstructions were produced from the DICOM data using an OsiriX viewer (Pixmeo SARL, Bernex, Switzerland), which clearly showed vessels over 0.5 mm in diameter (Fig. 1). After virtual dissection we recorded the position of the periosteal branches of the peroneal artery along the fibula (Fig. 2). We excluded the proximal and distal 6 cm regions of the bones because they are not normally harvested. We modelled osteotomy segments of 1.0, 1.5, and 2.0 cm and counted the number of periosteal branches of the peroneal artery.
Results We found a mean (SD) number of 12.8 (1.82) periosteal branches/fibula with a mean (SD) distance between them of 1.36 (0.18) cm. At least one branch was found in 65.1% of the 1 cm segments, in 83.4% of the 1.5 cm segments, and in 94% of the 2 cm segments (Table 1).
Acknowledgements I would like to acknowledge the generous support of the Derby Radiology department in particular Dr Simon Elliott and the technical assistance of Dr Richard Tunstall Associate Professor of Anatomy.
References 1. Hidalgo DA, Rekow A. A review of 60 consecutive fibula free flap mandible reconstructions. Plast Reconstr Surg 1995;96:585–602. 2. Jones NF, Swartz WM, Mears DC, et al. The “double barrel” free vascularized fibular bone graft. Plast Reconstr Surg 1988;81:378–85. 3. Fry AM, Tunstall R, Laugharne D, et al. The double-paddled osseocutaneous fibular flap—a combined CT and dissection study. Br J Oral Maxillofac Surg 2013;51:e97–8. 4. Sedlmayr JC, Witmer LM. Rapid technique for imaging the blood vascular system using stereoangiography. Anat Rec 2002;267:330–6. 5. Bähr W. Blood supply of small fibula segments: an experimental study on human cadavers. J Craniomaxillofac Surg 1998;26:148–52.
Please cite this article in press as: Fry AM, et al. Osteotomising the fibular free flap: an anatomical perspective. Br J Oral Maxillofac Surg (2015), http://dx.doi.org/10.1016/j.bjoms.2015.11.009