The procedure to procure a free sternoclavicular graft for TMJ reconstruction was made popular by Wolford et al. [3]. The fundamental determinant in the success of this traditional nonvascularised technique is to position the graft such that it can be vascularized by direct exposure of the marrow to adjacent soft tissue. Although placement of multiple holes throughout the harvested graft and decortication of the recipient bed have been performed to support revascularization, the free graft may still undergo degenerative changes due to ischaemia [2]. Moreover, the above procedures may also decrease the strength of the fragile harvested bone. Using an L - shaped osteotomy as proposed by the authors in the current study, the medullary bone is exposed at two different aspects, i.e., the dorsal and inferior aspects of the clavicle. (Fig. 1C). The authors believe that this modification to the osteotomy design may result in a graft with a higher survival rate due to greater chances of vascularization and improves adaptability for fixation.
Furthermore, the original technique proposed by Wolford et al. [3] required that SCG should be positioned at the posterior border of the mandible and rotated 90 degrees, so that it can fit into the fossa and form a bone interface with the ramus. However, this may require partial resection of the posterior border in some cases. On the contrary, the graft's size is decreased when the modified harvest approach is used, which may improve the graft's ability to adapt to the mandible.
The brachial plexus and other important blood vessels in the area may be injured as a result of the clavicle's postoperative fracture since the fractured bone segments are unstable [3, 5]. The incidence of clavicle fractures developed postoperatively as a result of graft harvesting using the traditional osteotomy design have been stated consistently in the literature, with reported occurrences of 16% (one in six instances) [2], 10% (5 of 52 cases) [3], and 13% (2 of 15 cases) [5] by various authors. In our series of 2 patients using the novel harvest approach, the authors found no clavicle fractures and showed excellent healing as determined by radiography at 6 months. This technique also avoids excessive dorsal subperiosteal dissection, which further negates the chances of vascular damage and pleural complications. Further, by preserving the inferior border of the clavicle, the strength of the donor site is maintained and the clavicle support could be discontinued in a few weeks provided all other precautions to prevent donor site fracture are followed. This is in contrast to the conventional technique given by Wolford et al. [3] in which the patients had to wear the figure of eight shoulder bandage for 3 months affecting their quality of life. The only disadvantage is that this technique should not be used in patients with clavicle less than 1 cm in width as it would fail to provide sufficient quantity and quality of graft.
In summary, the following are key elements of the new harvest approach to SCG that produce an improved outcome:
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Revascularisation of the graft is easier considering the exposure of medullary bone on two surfaces, thus improving the viability of the graft.
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The rapid formation of bone at the donor site is because the amount of bone harvested is minimal.
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Reduced bulk of the graft allows better adaptation at the recipient site.
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The pleura and neurovascular systems are protected by the lack of periosteal reflection on the dorsal and inferior portion of the clavicle.
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Maintaining the lower and posterior aspect of the clavicle improves the integrity of the lower half of the arm and shoulder support.
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Negligible requirement for postoperative support bandage at graft site.
In conclusion, the use of the modified technique may prove beneficial to patients by decreasing the morbidity associated with graft harvest, improved graft viability in all patients and enriched patient’s satisfaction. However, the results need to be confirmed by a large scale multicentric study with a long-term follow-up and larger sample size based on evolving surgical practices.