Fibula free flap in maxillomandibular reconstruction. Factors related to osteosynthesis plates' complications

Risk of Plate Exposure in Vascularized Fibula Flap for Mandibular Reconstruction in Primary Oral Cancers

To investigate the risk factors for plate exposure in primary oral cancer patients with mandibular defects undergoing tumor ablation followed by vascularized free fibular flap (FFF) transfer, we conducted a retrospective observational STUDY IN A SINGLE INSTITUTION IN TAIWAN: .The study was performed on a total of 292 primary oral cancer patients who underwent FFF reconstruction between 2015 and 2019. A variety of clinicopathological, surgical, and postoperative parameters were identified and assessed. The data were statistically analyzed with univariate and multivariate logistic regression, and the probability of plate exposure-free rate was plotted as Kaplan-Meier survival curve.The overall plate exposure rate was 28.76%. The re-exploration group had a higher rate of plate exposure than patients without re-exploration (12.2% vs. 5%, p < 0.05). The 3-year probability of plate exposure-free rates in patients with (n = 216) and without (n = 76) postoperative radiotherapy were 65.9 and 92.5%, and in patients with (n = 141) and without (n = 151) postoperative wound infection were 55.3 and 91.2%, respectively. The multivariate logistic regression showed postoperative radiotherapy and wound infection were independent risk factors for developing plate exposure (adjusted odds ratio [95% CI]: 3.73 [1.37-10.68] and 10.71 [5.15-22.26], p = 0.01 and p <0.001, respectively). More patients required surgical intervention to manage the exposure of hardware.Our study has highlighted that postoperative radiotherapy and postoperative wound infection are independent risk factors for plate exposure.

Virtual surgical planning in microsurgical head and neck reconstruction: The Newcastle experience

Head and neck microvascular reconstruction is a complex but powerful tool following immediate cancer ablation or delayed sequalae after cancer treatment. Virtual surgical planning (VSP), using computer-aided design or computer-aided manufacturing has emerged as a potentially beneficial adjunct to head and neck reconstruction. The aim of this study was to assess the outcomes of VSP technology using the KLS Martin custom-made cutting guides and low-profile plates in head and neck microvascular reconstruction in our centre. A retrospective study was conducted at the regional head and neck centre in the UK from March 2017 until June 2023. A total of 127 patients were included. Among them, 77.8% of the patients underwent immediate reconstruction following cancer ablative procedure, with 22.2% being treated for osteoradionecrosis. Median flap ischaemia time was 130 min (45-360 min). Median number of osteotomies was 1 (0-3). Median operative time was 622 min (302-962 min). Procedural complications occurred in 16.2% of the patients. Total flap failure rate was 6.35%. This study found that patients who were operated on with palliative intent had significantly worse flap survival rates (p < 0.033). The length of hospital stay was significantly impacted by longer operative time (p < 0.002) and overall length of intensive therapy unit stay was significantly increased in diabetic and palliative patients. Three-dimensional planning software has become a standard of care within our centre, leading to shorter operative time, reliable and accurate reconstruction and a short learning curve for skill acquisition. Extensive surgery in palliative patients requires a robust consenting process in the context of a multi-disciplinary team discussion.

Risk Factors for Plate Infection, Exposure, and Removal in Mandibular Reconstruction

OBJECTIVE

Mandibular plate reconstruction (MPR) is often indicated after tumor ablation, osteoradionecrosis excision, and traumatic bone loss to restore oral functionality and facial cosmetics. There are limited analyses identifying risk factors that lead to plate infection (PIn), exposure, and removal ("plate complications").

STUDY DESIGN

Retrospective cohort study.

SETTING

Academic tertiary medical center.

METHODS

Patients who underwent MPR from 2013 to 2022 were identified. Risk factors for plate complications were analyzed based on demographic, clinical, intraoperative, and postoperative factors. Multivariable analysis was conducted with logistic regression. Survival analysis was conducted with a Cox model.

RESULTS

Of the 188 patients analyzed, 48 (25.5%) had a plate complication [infection: 22 (11.7%); exposure: 23 (12.2%); removal: 35 (18.6%)]. Multivariate analysis revealed predictive associations between at least 1 plate complication and the following variables: smoking status, soft tissue defect size, number of plates, average screw length, and various postoperative complications. Other associations approached the threshold for significance. Prior and adjuvant radiation therapy, type of free flap, stock versus custom plates, and perioperative antibiotic prophylaxis regimens were not associated with plate complications. No plate complication was independently associated with lower overall survival. PIn (hazard ratio, HR: 7.99, confidence interval, CI [4.11, 15.54]) and exposure (HR: 3.56, CI [1.79, 7.08]) were independently associated with higher rates of plate removal.

CONCLUSION

Plate complications are relatively common after MPR. Smoking history, specific disease characteristics, hardware used during surgery, and postoperative complications may help identify higher-risk patients, but additional larger-scale studies are needed to validate our findings and resolve discrepancies in the current literature.

Biocompatibility Evaluation of an Artificial Metallic Bone with Lattice Structure for Reconstruction of Bone Defect

Mandibular reconstruction for large bone defects is performed with consideration of patients' specific morphology and sufficient strength. Metal additive manufacturing techniques have been used to develop biomaterials for mandibular reconstruction. Titanium artificial mandibles with a lattice structure have been proposed, and the optimal conditions for their strength to withstand mechanical stress around the mandible have been reported. This study investigated the biocompatibility of a titanium artificial bone with a lattice structure fabricated under optimal conditions. The samples were fabricated using metal additive manufacturing. Body diagonals with nodes (BDN) were selected as suitable lattice structures. Dode medium (DM) was selected for comparison. The samples were implanted into rabbit tibial defects and resected with the surrounding bone at two and four weeks. Specimens were evaluated radiographically, histologically, and histomorphometrically. Radiopacity in each lattice structure was observed at two and four weeks. Histological evaluation showed trabecular bone-like tissue inside the BDN compared to the DM at four weeks. No significant differences were noted in the bone volume inside the structures. This study demonstrated the in vivo compatibility of artificial metallic bones with a BDN structure under mechanical stress conditions.

Progress of Ossification after Mandibular Reconstruction by Free Fibula Flap Depending on Different Timing of Radiotherapy: A Retrospective 3D Analysis by CT Scans

Background: The aim of this study was to evaluate the difference between pre- and post-operative radiotherapy on the progress of ossification after free fibula flap reconstruction of the mandible using three-dimensional (3D) analysis. Methods: A total of 38 free fibula reconstructions of the mandible were evaluated retrospectively for ossification between bone segments by measuring Hounsfield Units (HU) in at least two postoperative computer tomography scans (average of 2.4 scans per patient; around the 5th, 12th, 16th, and 19th month postoperative). Three subgroups were created according to the time of irradiation: preoperative radiotherapy (preORT) (n = 11), postoperative radiotherapy (postORT) (n = 16), and patients without any radiation therapy (n = 11) as the control group (noRT). HU in eight regions of interest (ROI) and overlapping surfaces between segments per contact point, as well as influencing factors, were analyzed. Results: The fastest progress in gain of HU ossification with a difference of 0.30 HU/day was observed in noRT compared to preORT (p = 0.002). postORT was -0.24 HU/day slower than preORT (p = 0.005). Original and grafted bone showed a significantly slower HU uptake than between two graft segments with -84.18 HU/day (p < 0.001). Moreover, a larger initial overlapping surface between the segments in cm2 resulted in a higher rise of HU/day (p < 0.001). Conclusions: 3D analysis of post-reconstructive CT scans shows prolonged ossification of mandible reconstructions by free fibula after head and neck radiation. The effect is distinct in cases with post-operative adjuvant radiotherapy. The effects of radiotherapy on ossification may be minimized by a larger initial contact surface and improved operational techniques. Moreover, HU longitudinal measurements and 3D analysis offer new perspectives for clinical evaluation of successful bony healing.

Development of a test bench for biomechanical simulation-a preliminary study of mandibular forces

Purpose: The aim of this study is to develop a test bench, which integrates different complexity levels and enables in that way a flexible and dynamic testing for mid and long term intervals as well as testing of maximum loads till implant failure of different osteosynthesis systems on the mandible. Material and Methods: For this purpose, an analysis of the state of the art regarding existing test benches was combined with interviews of clinical experts to acquire a list of requirements. Based on these requirements a design for a modular test bench was developed. During the implementation of the test stand, functional tests were continuously carried out and improvements made. Depending on the level of complexity, the test bench can be used either as an incorporated variant or as a standalone solution. In order to verify the performance and the degree of fulfilment of the requirements of these two variants of the test bench, preliminary studies were carried out for all levels of complexity. In these preliminary studies, commercially available osteosynthesis and reconstruction plates were investigated for their biomechanical behaviour and compared with data from the literature. Results: In total, fourteen test runs were performed for the different levels of complexity. Firstly, five test runs were executed to test the simplified load scenario in the incorporated variant of the test bench. High forces could be transmitted without failure of the miniplates. Secondly a quasi-static test scenario was examined using the incorporated variant with simplified load insertion. Five experiments with a number of cycles between 40,896 and 100,000 cycles were carried out. In one case the quasi-static testing resulted in a fracture of the tested reconstruction plate with a failure mode similar to the clinical observations of failure. The last four test runs were carried out using the standalone variant of the test bench simulating complex load patterns via the insertion of forces through imitated muscles. During the test runs joint forces were measured and the amplitude and vector of the resulting joint forces were calculated for both temporomandibular joints. Differences in the force transmission depending on the implant system in comparison to the zero sample could be observed. Conclusion: The presented modular test bench showed to be applicable for examination of the biomechanical behavior of the mandible. It is characterized by the adjustability of the complexity regarding the load patterns and enables the subsequent integration of further sensor technologies. Follow-up studies are necessary to further qualify and optimize the test bench.

Postoperative facial appearance of patients with extensive oral squamous cell carcinoma can be adequately preserved with in‑house virtually planned mandibular reconstruction

The present study aimed to assess the concordance of preoperative and postoperative hard and soft tissues in patients with advanced oral squamous cell carcinoma (OSCC) following virtual surgical planning (VSP) mandibular reconstruction. In the present study, a cohort of 32 patients with OSCC underwent in-house VSP, followed by guided mandibular reconstruction utilizing vascularized free tissue grafts sourced from the fibula or scapula. A morphometric analysis was conducted comparing preoperative and postoperative three-dimensional virtual models to evaluate discrepancies and identify potential risk factors associated with poor reconstruction outcomes. The outcome variables were the differences in root mean square (RMS) and mean surface distance (MSD) resulting from the application of an iterative closest point algorithm to the virtual data. The validity of soft tissue comparison data is limited due to its susceptibility to various confounding variables. The present study conducted a comprehensive re-evaluation of these variables. High tumor stage, positive N status and the use of adjuvant therapy contributed to more noticeable differences in preoperative and postoperative facial soft tissue appearance. The accuracy of postoperative bone reconstruction results was higher in patients who underwent neomandibular formation using a fibular graft compared with those who received a scapular graft. Preoperative and postoperative soft tissue analyses were conducted for comparison. The MSD showed a deviation of 3.2 mm (± 2.0 mm SD; range 1.3-9.5 mm), whereas the RMS was 5.3 (± 2.9 SD; range 2.1-14). In conclusion, in-house VSP and guided mandibular reconstructions can yield clinically accurate results, preserving patient appearance and offering the advantage of rapid feasibility.

Patient-specific 3D-printed mini-versus reconstruction plates for free flap fixation at the mandible: Retrospective study of clinical outcomes and complication rates

This study aimed to compare the clinical outcomes and complication rates of patient-specific 3D-printed mini- and reconstruction plates for free flap fixation in mandibular reconstruction. A retrospective monocentric study was carried out between April 2017 and December 2021 to analyze patients undergoing immediate mandibular reconstruction using fibula free flaps and osteosynthesis using patient-specific 3D-printed implants. Eighty-three patients with a mean age of 63.6 years were included. The mean follow-up period was 18.5 months. Patient-specific 3D-printed plates were designed as reconstruction plates (38 patients), miniplates (21 patients) or a combination of reconstruction- and miniplates (24 patients). With miniplates, plate removal was performed significantly more often via an intraoral approach (p < 0.001) and in an outpatient setting (p = 0.002). Univariate analysis showed a higher fistula rate with reconstruction plates (p = 0.037). Multivariate analysis showed no significant differences in complications. Case-control matching demonstrated significantly lower rates of fistula (p = 0.017) and non-union (p = 0.029) in the combined group. This retrospective study shows a tendency towards reduced complication rates with patient-specific 3D-printed miniplates in comparison to patient-specific 3D-printed reconstruction plates for immediate mandibular reconstruction with fibula free flaps.

Outcome of Mandibular Reconstruction with Fibula free Flaps: Retrospective Analysis of Complications

Rationale: Fibula free flap has become the workhorse for head and neck reconstruction. In this retrospective study we aimed at determining the outcomes of mandibular reconstruction with fibula free flaps. Methods: Any patient who underwent a mandibulectomy and reconstructed with vascularised fibula flap was included in the study. The predictor variables were age, sex, type of lesion, tobacco and alcohol use, tracheostomy, neck dissection, post operative radio and chemotherapy. Flap failure, fistulas, dehiscence, bone exposure and hardware complications were the outcomes. A P value of < 0.05 was considered statistically significant. Results: 242 patient records were selected for evaluation. PORT, CRT, neck dissection, no. of segments were the factors significantly associated with every complication. Malignant lesion was significantly associated with every complication except for plate fracture. Plate fracture although occurred more frequently with malignant diseases, the association was insignificant. Tobacco consumption was significantly associated with increased incidence of post -operative complications. Alcohol consumption was significantly associated with plate fracture, screw loosening, fistulas, bone exposure and flap failure. Conclusion: Overall the fibula free flap has a success rate of 90.0% with fistulas being the most significant complication.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03344-2.

Risk factors associated with fixation-related complications in microsurgical free flap reconstruction of the mandible

BACKGROUND

Hardware complications (loosening of screws, infection, or exposure of the plate) in mandibular reconstruction with vascularized osseous free flaps impose significant morbidity, and frequently require revision surgery. Purpose of this study was to identify possible contributing factors for hardware complications.

METHODS

This is a retrospective cohort study involving case series of patients who underwent microvascular mandible reconstructions between 2000 and 2020. Patient demographics, pathological, clinical, and treatment-related factors were analyzed in univariate and multivariate analyses.

RESULTS

Ninety-one patients were enrolled, encompassing 63 reconstructions with fibular free flaps, 26 reconstructions with scapular, and 2 reconstructions with iliac flaps. Rate of hardware complications and plate exposure was 14.3% and 7.7%, respectively, with a median follow-up time for extrusion of 29 months. In univariate analysis, preoperative radiotherapy (odds ratio [OR] = 6.57, p = .01), and secondary mandible reconstruction (OR = 4.3, p = .04) were significant predictors of hardware complications, and plate exposure was most frequently found in secondary reconstruction (37.5%, OR = 11.8, p = .04). Hypertension was the most commonly found comorbidity (24%), and it trended toward significance regarding plate exposure (p = .05). Only secondary mandible reconstruction was associated with osteosynthesis complications (OR = 12.53, p = .01) and plate exposure (OR = 23.86, p = .005) on multivariate analysis, while preoperative radiation therapy did not retain its relevance on plate exposure.

CONCLUSION

Secondary mandible reconstructions with vascularized osseous free flaps have a higher risk of osteosynthesis complications than primary reconstructions.

The comprehensive on-demand 3D bio-printing for composite reconstruction of mandibular defects

Background

The mandible is a functional bio-organ that supports facial structures and helps mastication and speaking. Large mandible defects, generally greater than 6-cm segment loss, may require composite tissue reconstruction such as osteocutaneous-vascularized free flap which has a limitation of additional surgery and a functional morbidity at the donor site. A 3D bio-printing technology is recently developed to overcome the limitation in the composite reconstruction of the mandible using osteocutaneous-vascularized free flap.

Review

Scaffold, cells, and bioactive molecules are essential for a 3D bio-printing. For mandibular reconstruction, materials in a 3D bio-printing require mechanical strength, resilience, and biocompatibility. Recently, an integrated tissue and organ printing system with multiple cartridges are designed and it is capable of printing polymers to reinforce the printed structure, such as hydrogel.

Conclusion

For successful composite tissue reconstruction of the mandible, biologic considerations and components should be presented with a comprehensive on-demand online platform model of customized approaches.

Influence of Radiotherapy on Ossification of Vascularized Osseous Reconstruction of the Jaw: A Radiological Retrospective Cohort Study Based on Panoramic Radiographs

Background: The aim of this study was to evaluate the impact of irradiation and time of irradiation on the ossification of jaws reconstructed with free bone grafts. Methods: In total, 100 reconstructions of the jaw were retrospectively evaluated for ossification between bone segments by two raters based on postoperative panoramic radiographs (immediate postOP, approximately 6, 12 and 24 months follow-up). Three subgroups were divided according to the time of irradiation: preoperative radiation therapy (n = 41), postoperative radiation therapy (n = 26) and patients without any radiation therapy (n = 33) as the control group. Ossification time and influencing factors were documented. Results: The fastest ossification with a median of 304 ± 37 days was observed (p < 0.001) in the nonirradiated control group. No significant difference (p = 0.087) in ossification was found between the pre- (447 ± 136 days) and postoperative (510 ± 112 days) radiation groups. Ossification between two graft segments (336 ± 38 days) showed significantly (p < 0.001) faster ossification than between the original and grafted bone (448 ± 85 days). Moreover, closer initial contact between the segments resulted in faster ossification (p < 0.001). When analyzing cofactors, tobacco consumption was the only negative factor aggravating ossification (p = 0.006). Conclusion: Head and neck radiation corresponded with the impaired and prolonged ossification of jaw reconstructions with free bone grafts. There was no difference in ossification if radiotherapy was performed before or after reconstructive surgery. A close bony contact was particularly important for ossification between the original and grafted bone.

Bone Union of Osseous Microvascular Free Tissue Transfer in Mandibular Reconstruction

Objectives

Osseous microvascular free tissue transfer (MFTT) is the gold standard for reconstruction for most segmental mandibulectomy defects. The most common osseous MFTT utilized in reconstruction is the fibular, scapular, and osteocutaneous radial forearm (OCRF) free flap. We evaluated postoperative bone union as well as clinical complications following MFTT and the impact of various patient and reconstructive characteristics, including type of osseous MFTT.

Study Design

Retrospective cohort study.

Setting

Tertiary care academic hospital.

Methods

This study examined patients who underwent osseous MFTT for mandibular defects from January 2017 to January 2019.

Results

An overall 144 osteotomies in 58 patients were evaluated. Of the 144 junctions, 28 (19.4%) showed radiographic nonunion. Patients who underwent preoperative (odds ratio [OR] = 0.30, P = .027) and postoperative (OR = 0.28, P = .003) radiation had a significantly lower bone union score. Time from surgery to postoperative imaging was associated with higher bone union scores (OR = 1.07, P = .024). When bone union scores were compared among types of MFTT, fibular (OR = 5.62, P = .008) and scapular (OR = 4.69, P = .043) MFTT had significantly higher scores than OCRF MFTT. Twelve (20.7%) patients had postoperative complications. There was no statistically significant correlation between clinical complications and various variables, including type of osseous MFTT.

Conclusion

Pre- and postoperative radiation and time from surgery have an impact on bone union. Regarding the type of MFTT, fibular and scapular MFTT appeared to have higher bone union when compared with OCRF. There was no impact of bone union or type of osseous MFTT on clinical complications.

Vertical mandibular bone augmentation by the osteodistraction of the transplanted fibula free flap: A case series with long-term follow-up

Vertical augmentation of the mandible to prepare dental implant therapy is still a challenge, especially with large mandible defects. Reconstruction with fibula free flap is a regularly applied approach in such cases, but it does not always yield optimal results: the resulting crestal height might differ significantly from the crestal height of the patient's intact bone, which makes esthetic and functional rehabilitation difficult. Osteodistraction of the integrated flap is a known but rarely discussed approach where the already integrated flap undergoes additional distraction. Through the four cases reported here, we would like to demonstrate that the osteodistraction of the transplanted fibula free flap is a useful and efficient method of secondary augmentation for cases where the flap itself fails to produce the desired crestal height, and no other method is applicable. The cases show that the method allows outcomes that are highly satisfactory, both in the functional and esthetic sense.