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Asian Journal of Surgery (2017) xx, 1e7
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.e-asianjournalsurgery.com
Original Article
Surgical treatment of isolated zygomatic fracture: Outcome comparison between titanium plate and bioabsorbable plate Chao-Ming Wu a, Ying-An Chen b, Han-Tsung Liao c, Chih-hao Chen c, ChuneHao Pan d, Chien-Tzung Chen d,* a
Department of Plastic Surgery, Chang Gung Memorial Hospital at Chiayi, Taiwan Craniofacial Center, Department of Plastic Surgery, Chang Gung Memorial Hospital at Linkou, Taiwan c Division of Trauma Plastic Surgery, Department of Plastic Surgery, Chang Gung Memorial Hospital at Linkou, Taiwan d Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital at Keelung, College of Medicine, Chang Gung University, Craniofacial Research Center, Taoyuan, Taiwan b
Received 22 November 2016; received in revised form 12 March 2017; accepted 15 March 2017
KEYWORDS Bioabsorbable plate; Titanium plate; Comparison; Zygoma fracture
Summary Background: Zygoma fracture is of clinical importance because malar prominence plays an essential role in facial appearance. Traditionally, most maxillofacial surgeons perform osteosynthesis with titanium plates and screws for rigid fixation. However, this procedure has certain disadvantages that include the possibility of implant exposure, palpability or loosening of the screws, painful irritation, temperature sensitization, and radiographic artifacts. In this study, we compared the function and satisfaction outcome between Bonamates bioabsorbable implant and Leibinger titanium implant. Method: Consecutively 53 patients with isolated unilateral zygomatic fracture that were treated with the Bonamates bioabsorbable plate system, n Z 53 were compared to patients with the titanium plate system, n Z 55 in the period between 2009 and 2013. All patients were followed-up at least 6 months. Preoperative and postoperative facial computed tomography (CT) scans were performed and scored from 0 to 2 in the 5 areas of zygoma. A score of 2 indicated the most severely displaced fracture in one of the areas. A visual analogue scale ranging from 0 to 10 was used to assess the postoperative aesthetic and functional satisfactions. Result: The mean ages of the patients in the bioabsorbable and titanium plate groups were 33 years and 30 years, respectively. The male to female ratios were 1.2:1 (bioabsorbable plate group) and 1.1:1 (titanium plate group). The average preoperative CT scan scores of the bioabsorbable and titanium plate groups were 5.7 and 5.1, respectively. The postoperative CT scan scores of the bioabsorbable and titanium plate groups were 1.3 and 1.1, respectively.
* Corresponding author. Department of Plastic and Reconstruction Surgery, Chang Gung Memorial Hospital at Keelung, Chang Gung University, College of Medicine, Craniofacial Research Center, 222, Maijin Road, Keelung, Taoyuan, Taiwan. Fax: þ886 2 24313161. E-mail address:
[email protected] (C.-T. Chen). http://dx.doi.org/10.1016/j.asjsur.2017.03.003 1015-9584/ª 2017 Asian Surgical Association and Taiwan Robotic Surgical Association. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Please cite this article in press as: Wu C-M, et al., Surgical treatment of isolated zygomatic fracture: Outcome comparison between titanium plate and bioabsorbable plate, Asian Journal of Surgery (2017), http://dx.doi.org/10.1016/j.asjsur.2017.03.003
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C.-M. Wu et al. The implant cost of the bioabsorbable group was approximately 6-fold higher than that of the titanium plate group. The complication rate was similar in both groups and included complications such as palpable implant, skin irritation, and hypersensitive cheek. The patients in both groups attained similar mouth-opening function and a satisfactory score at 6 months after operation. Conclusion: This study revealed that the bioabsorbable plate outcome was similar to the titanium plate outcome for patients with isolated unilateral zygomatic fracture. The bioabsorbable implant system provides another option for internal fixation devices in the treatment of zygomatic fractures and avoids implant removal surgery; however, the implant cost of bioabsorbable plates is higher than that of titanium plates in Taiwan. ª 2017 Asian Surgical Association and Taiwan Robotic Surgical Association. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction Zygoma fracture is of clinical importance regarding facial appearance and function. Displaced malar prominence plays an essential role in the overall facial appearance and results in deformity of the facial contour. Open reduction and internal fixation are required to avoid ophthalmic complications and masticatory dysfunctions in displaced fractures.1 The most essential criteria for the successful treatment of zygomatic fractures are accurate reduction and the 3-dimensional stability of the displaced fracture to achieve favorable aesthetic and functional results.2,3 Titanium plates and screws are used regularly for the rigid fixation of zygomatic fractures. However, certain disadvantages including the possibility of implant exposure, palpable implant, screws loosening, pain sensation, cold intolerance, and radiographic artifacts still exit.4,5 Some patients require secondary operation to remove plates, and the removal rate is 10e22.7%.6e8 To overcome the complications inherent in the titanium implant system, bioabsorbable osteosynthesis has been developed. The use of bioabsorbable plates and screws is an attractive alternative compared with that of the traditional metal plate system.9 Because bioabsorbable implants are completely resorbed, secondary surgery for removing implants and long-term interference with nerves and the growing skeleton can be prevented. In addition, the risk of implant-associated stress shielding, peri-implant osteoporosis, and infections is reduced. Furthermore, bioabsorbable implants do not interfere with clinical imaging and do not cause sensitivity to cold weather.10 The strength of the bioabsorbable plate system is a major concern in its implementation. Hanemann et al reported that combination of titanium plating and resorbable plating systems exhibits adequate strength with negligible complications for the treatment of isolated zygomatic fractures in adults.11 Furthermore, using only the bioabsorbable plate system showed stable fixation in displaced zygomaticomaxillary complex fractures.12 There are 2 types of bioabsorbable plate: homopolymer (Poly-L-lactic acid (PLLA), and polyglycolic acid (PGA)) and copolymer (Lactosorb, BioSorb, and DeltaSystem). A commercially available bioabsorbable system composed of 1.2-mm-thick plates and 2.5-mm-diameter screws (BonaPlates, PD series, Bonamates, BioTech One, Taipei, Taiwan) has recently been developed in Taiwan. To test the
efficiency of the new bioabsorbable plate, we conducted a study to compare the outcomes of the Bonamates bioabsorbable implants and titanium implants on a group of patients with isolated zygomatic complex fractures.
2. Materials and methods This is a retrospective caseecontrol study. Consecutively 53 patients with isolated unilateral zygomatic complex fracture were treated with the bioabsorbable plate system (Bonamates) between 2009 and 2013. Patients with simple zygomatic arch fracture, comminuted fracture at each junction of zygoma and other facial bone, and multiple midfacial fractures were excluded in this study. To compare the outcome between the bioabsorbable and titanium plate systems, control group are patients of similar isolated zygomatic complex fractures (n Z 55) was treated with the titanium plate system between the 2009 and 2013. The fracture site is explored through the gingivobuccal incision (Fig. 1). After achieved adequate reduction, fixation is performed with a bioabsorbable or titanium plate at the lateral buttress, and this is the first fixation point. If fixation was not rigid or reduction was not adequate during operation, it is necessary to explore other fracture sites for the second or third fixation points. We created an infracilliary incision to approach the infraorbital rim and zygomaticofrontal (Z-F) junction. The infraorbital rim is the typical second fixation point and followed by the Z-F junction if necessary. All the surgical procedures were performed by a single surgeon to avoid surgical bias. For evaluation the fracture displacement and adequacy of fracture reduction, we developed a CT scan scoring system. Five anatomic points with the total score range from 0 to 10 (0e2 for each point). A score of 2 represented the most comminuted preoperative displacement and inadequate reduction of more than 2 mm after operation. A score of 1 indicated fracture displacement of less than 2 mm or nonunion (absence of calcified bone crossing the fracture site). A score of 0 represented a minimal to nondisplaced fracture line preoperatively and accurate alignment with bone union postoperatively. Five evaluation points, including the ZeF junction, sphenoidezygomatic (SeZ) junction, inferior orbital rim, zygomatic arch, and lateral buttress, were assessed in a series of CT scans preoperatively and 6 months postoperatively (Table 1).
Please cite this article in press as: Wu C-M, et al., Surgical treatment of isolated zygomatic fracture: Outcome comparison between titanium plate and bioabsorbable plate, Asian Journal of Surgery (2017), http://dx.doi.org/10.1016/j.asjsur.2017.03.003
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Surgical treatment of isolated zygomatic fracture
Figure 1 buttress.
Table 1
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Intraoperative view showing the bioabsorbable plate used to stabilize the fracture sites of the zygomaticomaxillary
Scoring system for assessment of the degree of fracture displacement and adequacy of reduction.
Score
0
1
2
Preoperative Postoperative
Minimal displacement Adequate reduction and union
Moderate displacement Mild displacement and nonunion
Segmental or comminuted displacement Inadequate reduction
The postoperative clinical assessments were performed regularly at 4, 12, and 24 weeks to evaluate patient satisfaction, using the visual analogue scale and functional outcome. A 10-cm line with both ends labeled as extremes and a score of 10 indicates high satisfaction. The patients marked an X at the point that represents their satisfaction most appropriately. The outcome of preoperative and postoperative score and satisfactory score between two plate groups are compared using the two-sample t-test for unpaired comparisons. For each test, a p value < 0.05 is considered statistically significant.
3. Results Both the bioabsorbable and titanium plate groups included patients (n Z 53, 55) with a follow-up at least 6 months. The mean of patient age in the bioabsorbable and titanium plate groups were 33 years and 30 years, respectively. The male-to-female ratios were 1.2:1 and 1.1:1 in the bioabsorbable and titanium plate groups, respectively. Comorbidity, associated injury, and trauma mechanisms were comparable between the groups. In both groups, the initial symptoms included malar depression with numbness in the territory of the infraorbital nerve in all patients. In addition, 6% diplopia and 4% enophthalmos (1 mm difference than normal eye) were observed in the
bioabsorbable plate group. By contrast, 22% diplopia and 18% enophthalmos were observed in the titanium plate group. The average preoperative CT scan scores of the bioabsorbable plate group were 5.5 (36% of patients), 5.9 (60%), and 5.1 (4%) for the one, two, and three points fixations, respectively. By contrast, the average preoperative CT scan scores of the titanium plate group were 4.5 (35%), 5.4 (62%) and 4.2 (2%) for the one, two and three points fixations respectively. The average preoperative CT scan score in the bioabsorbable plate group was 5.7 and improved to 1.3 postoperative with an improvement degree of 4.3 (Figs. 2 and 3). In the titanium plate group, the average preoperative CT scan score was 5.1 and improved to 1.1 postoperative with an improvement degree of 4. The average operation time for the bioabsorbable plate group was 40 min longer than that for the titanium plate group. In addition, the average implant cost of the bioabsorbable plate group was 5.52-fold higher than that of the titanium plate group (Table 2). The complications included palpable implant, hypersensitive cheek, skin irritation, and ectropion. The complication rate was similar in both groups. The maximal mouth-opening function was higher in the bioabsorbable plate group in the first 3 postoperative months, but a similar function was observed in both groups in the first 6 postoperative months (Fig. 4). The appearance satisfaction
Please cite this article in press as: Wu C-M, et al., Surgical treatment of isolated zygomatic fracture: Outcome comparison between titanium plate and bioabsorbable plate, Asian Journal of Surgery (2017), http://dx.doi.org/10.1016/j.asjsur.2017.03.003
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Figure 2 A Preoperative 3-dimensional computed tomographic scan showing the left zygomatic complex fracture with severe displacement over the inferior orbital rim and lateral buttress fracture. Figure 2B Postoperative CT scan at 6 months revealing the bioabsorbable plate located at the inferior orbital rim and lateral buttress.
Figure 3 A Preoperative 3-dimensional CT scan showing the moderate displacement of the left zygoma complex. Figure 3B Postoperative 3-dimensional CT scan at 23 months postoperation showing the adequate reduction of left zygoma with the bioabsorbable plate fixed at the lateral buttress.
was assessed in both groups at 1, 3, and 6 months postoperation (Fig. 5). No case in either group required a secondary procedure for removing the implant during the follow-up period of 6 months.
4. Discussion In general, 2 types of bioabsorbable plate are available on the market; one is homopolymer, including PLLA and PGA. PLLA was the first bioabsorbable material applied in treating facial trauma, which was used in the treatment of patients with zygomatic fracture by Rudolf in 1987. PGA has more rapid hydrolysis and triggers higher inflammatory reaction.13 The disadvantages of homopolymer include unfavorable degradation, foreign body reaction, prominent swelling irrespective of the implant location, and the requirement of surgical removal.14 Therefore, pure PLLA and PGA are no longer used.
The other type of bioabsorbable plate is copolymer, which includes the following: (1) Lactosorb, comprising PLLA/PGA (82/18) with crystallinity of
