CLINICAL APPLICATION OF 3D PRINTING TECHNOLOGY FOR PREOPERATIVE PLANNING OF THUMB RECONSTRUCTION.

OBJECTIVE: This study aimed to explore the clinical application of preoperative precise design for 3D printing and thumb reconstruction, which could help manage the patients with thumb defect and achieve better function and appearance. METHODS: This was a retrospective study of 20 patients who underwent the surgery of harvesting toe transplant and thumb reconstruction between January 2015 and December 2016. The 3D model of the thumb defect was created and printed. The dimensions of skin and bones from donor site were precisely designed as reference for surgical operation. The surgery was performed according to the model. RESULTS: Perfect repair of defects was achieved with satisfying appearance and function. The reconstructed thumbs all survived (survival rate of 100%). Follow-up was 3-9 months. The maximum dorsiflexion was 8-30° and the maximum flexion was 38-58°. The two-point sensory discrimination was 9-11 mm. In total, 17 patients reposted "Excellent" satisfaction and three "Good", each for the reconstructed thumb and hand function, respectively. The satisfaction rate was 85%. CONCLUSION: Preoperative digital design and 3D printing according to the donor and recipient sites allowed a tailored operation. The operation was more precise, the appearance of the reconstructed thumb was good. Level of Evidence II, Retrospective Study.

OBJETIVO: Este estudo explorou a aplicação clínica do desenho pré-operatório preciso para impressão 3D e reconstrução do polegar, para ajudar no controle e melhorar função e aparência. MÉTODOS: Estudo retrospectivo de 20 pacientes submetidos à cirurgia de colheita de transplante de dedo do pé e reconstrução do polegar entre janeiro de 2015 e dezembro de 2016. O modelo 3D do defeito do polegar foi confeccionado e impresso. As dimensões da pele e dos ossos da área doadora foram precisamente projetadas como referência para a operação cirúrgica, realizada de acordo com o modelo. RESULTADOS: O reparo perfeito foi alcançado com aparência e função satisfatórias. Todos os polegares reconstruídos sobreviveram (taxa de sobrevivência de 100%). O acompanhamento foi de 3-9 meses. A dorsiflexão máxima foi de 8-30° e a flexão máxima foi de 38-58°. A discriminação sensorial de dois pontos foi de 9-11 mm. No total, 17 pacientes reportaram índice "Excelente" e três índice "Bom" cada para a função reconstruída do polegar e da mão, respectivamente. O índice de satisfação foi de 85%. CONCLUSÃO: O design digital pré-operatório e a impressão 3D de acordo com os locais doador e receptor permitiram uma operação customizada. A operação foi mais precisa, com bom aspecto. Nível de Evidência II, Estudo Retrospectivo.

Clinical application of 3d printing technology for preoperative planning of thumb reconstruction / Aplicação clínica da tecnologia de impressão 3d para planejamento pré-operatório de reconstrução de polegar

ABSTRACT Objective: This study aimed to explore the clinical application of preoperative precise design for 3D printing and thumb reconstruction, which could help manage the patients with thumb defect and achieve better function and appearance. Methods: This was a retrospective study of 20 patients who underwent the surgery of harvesting toe transplant and thumb reconstruction between January 2015 and December 2016. The 3D model of the thumb defect was created and printed. The dimensions of skin and bones from donor site were precisely designed as reference for surgical operation. The surgery was performed according to the model. Results: Perfect repair of defects was achieved with satisfying appearance and function. The reconstructed thumbs all survived (survival rate of 100%). Follow-up was 3-9 months. The maximum dorsiflexion was 8-30° and the maximum flexion was 38-58°. The two-point sensory discrimination was 9-11 mm. In total, 17 patients reposted "Excellent" satisfaction and three "Good", each for the reconstructed thumb and hand function, respectively. The satisfaction rate was 85%. Conclusion: Preoperative digital design and 3D printing according to the donor and recipient sites allowed a tailored operation. The operation was more precise, the appearance of the reconstructed thumb was good. Level of Evidence II, Retrospective Study.

RESUMO Objetivo: Este estudo explorou a aplicação clínica do desenho pré-operatório preciso para impressão 3D e reconstrução do polegar, para ajudar no controle e melhorar função e aparência. Métodos: Estudo retrospectivo de 20 pacientes submetidos à cirurgia de colheita de transplante de dedo do pé e reconstrução do polegar entre janeiro de 2015 e dezembro de 2016. O modelo 3D do defeito do polegar foi confeccionado e impresso. As dimensões da pele e dos ossos da área doadora foram precisamente projetadas como referência para a operação cirúrgica, realizada de acordo com o modelo. Resultados: O reparo perfeito foi alcançado com aparência e função satisfatórias. Todos os polegares reconstruídos sobreviveram (taxa de sobrevivência de 100%). O acompanhamento foi de 3-9 meses. A dorsiflexão máxima foi de 8-30° e a flexão máxima foi de 38-58°. A discriminação sensorial de dois pontos foi de 9-11 mm. No total, 17 pacientes reportaram índice "Excelente" e três índice "Bom" cada para a função reconstruída do polegar e da mão, respectivamente. O índice de satisfação foi de 85%. Conclusão: O design digital pré-operatório e a impressão 3D de acordo com os locais doador e receptor permitiram uma operação customizada. A operação foi mais precisa, com bom aspecto. Nível de Evidência II, Estudo Retrospectivo.

Application of computed tomography angiography-assisted classification of arterial branches in the first web space of the foot for thumb reconstruction.

BACKGROUND: Computed tomography angiography (CTA) has become a widely used imaging modality in vascular surgery. The first web arterial branches of the foot are significant for surgical planning of the donor site for thumb reconstruction. METHODS: We retrospectively analysed 30 thumb reconstructions with free second toe/great toe wrap-around flap transfer, performed between January 2016 and January 2019. The mean patient age was 30 (2-45) years. The causes of hand injury were: 20 machine strangulation injuries, 6 heavy weight smash injuries, and 4 crush injuries. Patients with iodine allergy were excluded preoperatively. We evaluated the effectiveness of CTA in visualizing first web arterial branches and compared it with intraoperative findings. Surgical plan for donor sites was prepared based on the classification of the first web arterial branches. RESULTS: The arterial branches of the patients were classified based on CTA findings as follows: (1) fork type: 24 patients (48 feet, 80%); (2) main trunk type: four patients (8 feet, 13.33%); and (3) side branch type: one patient (2 feet, 3.33%). One case of poor vascular continuity and artifacts in CTA underwent thumb reconstruction with free great toe wrap-around flap transfer. Tissue survival was achieved in all reconstructed thumbs. During the follow-up period (average, 12 months), all reconstructed thumbs exhibited good outcomes. The donor sites on the feet of all patients recovered well. CONCLUSION: CTA allows preoperative assessment of blood supply and planning of donor site. Our results can serve as a reference for surgical planning of the donor site while reducing the occurrence of adverse events.

O-arm navigation for sacroiliac screw placement in the treatment for posterior pelvic ring injury.

PURPOSE: This study aims to investigate the application value of O-arm navigation system in sacroiliac screw placement for the treatment of unstable pelvic ring injury. METHODS: A total of 40 patients (mean age = 30.75 ± 14.99 years, 25 males, 15 females) were included. From January 2016 to July 2018, 40 patients with posterior pelvic ring injury treated in our hospital were included. Of them, 19 patients underwent O-arm navigation for screw placement (O-arm group) while the other 21 received C-arm fluoroscopy guidance (C-arm group) for sacroiliac screw placement. Intraoperative outcomes and the outcome of screw placement were compared between groups. The quality of radiological images was assessed by Matta's radiological outcome grade. The outcome of complex pelvic fracture treatment was evaluated by Majeed Functional score. RESULTS: All demographic and clinical characteristics were comparable between the two groups. Compared with the C-arm groups, the O-arm group had a shorter surgery time (33.19 ± 3.14 vs. 48.35 ± 4.38 min, P < 0.001), a higher overall good outcome "excellent + good" rate of screw placement (95.45% vs. 73.91%, P < 0.05), and a significantly higher Majeed Functional score better outcome of complex pelvic fracture treatment at 1 and 3 months postoperation (both P < 0.05). CONCLUSION: Our results demonstrated that O-arm navigation system is feasible and safe for the treatment of posterior pelvic ring injury and can effectively improve the accuracy and safety of sacroiliac screw placement, shorten the operation time, and help rapid postoperative functional recovery.

Radiation Exposure and Operation Time in Percutaneous Endoscopic Lumbar Discectomy Using Fluoroscopy-Based Navigation System.

OBJECTIVE: This study evaluated radiation exposure and operation time of percutaneous endoscopic lumbar discectomy (PELD) by using a fluoroscopy-based navigation system for access and localization. METHODS: Eighty-six PELDs performed by a single surgeon were retrospectively analyzed. Patients were separated into 2 groups: group A (using a three-dimensional [3D]-printed navigation instrument and fluoroscopy-based navigation system) and group B (with conventional fluoroscopy and standard instrumentation). The operation, fluoroscopy, and total access time were collected, as well as fluoroscopy and access times. RESULTS: The operative time for group A was 59 minutes (standard deviation [SD], 6 minutes) and 106 minutes (SD, 15 minutes) in group B (P < 0.001). In group A, fluoroscopy was used an average of 5 times (SD, 0.7) and 29 times (SD, 8) in group B (P < 0.001). The fluoroscopy time was 9 minutes (SD, 2 minutes) in group A and 40 minutes (SD, 8 minutes) in group B (P < 0.001). The number of access attempts was 1.3 (SD, 0.5) in group A and 8 (SD, 2 times) in group B (P < 0.001). The total access time was 11 minutes (SD, 2 minutes) in group A and 28 minutes (SD, 5 minutes) in group B (P < 0.001). CONCLUSIONS: PELD using the fluoroscopy-based navigation system showed lower operative, fluoroscopy, and access time compared with conventional techniques. In addition, fewer fluoroscopy images and access attempts were made in the navigation group. These data suggest that this novel technique reduces fluoroscopy and operation time and may reduce risks of repeated surgical access attempts.

Computed Tomography Angiography Allows the Classification of the First Dorsal Metatarsal Arteries.

Background Conventional angiography is an invasive technique. Submillimeter computed tomography angiography (CTA) has been shown to be an effective alternative for peripheral artery branches. This study aimed to assess the use of CTA to guide the choice and design of foot donor area for finger or thumb reconstruction. Methods This was a retrospective study of 79 patients who underwent finger or thumb reconstruction between January, 2011 and March, 2014. All these patients underwent preoperative CTA to determine the exact blood supply at the donor site. Preoperative imaging and intraoperative findings at the donor site were compared. Results Among the 79 patients (158 feet), 474 artery segments (dorsalis pedis artery [DPA], first dorsal metatarsal artery [FDMA], and toe web artery [TWA]) were evaluated using CTA. Image satisfaction rates of the vessels were 100.0 ± 0.0%, 89.2 ± 3.2%, and 60.1 ± 5.0% for DPA, FDMA, and TWA, respectively. Among the 158 feet, 90 were Gilbert type I (57.0%), 52 were Gilbert type II (32.9%), 13 were Gilbert type III (8.2%), and 3 were with poor visibility and could not be classified (1.9%). In all 79 patients, the CTA image of the FDMA was consistent with the intraoperative observations. All reconstructed fingers survived. Follow-up was available for 69 patients. After a 6- to 18-month follow-up, the reconstructed fingers and donor area recovered well, and the reconstructed fingers had strong holding power, without pain. Conclusion CTA can produce three-dimensional images for extremity arteries, allowing the preoperative assessment of blood supply and planning of donor site.

A Novel Preoperative Planning Technique Using a Combination of CT Angiography and Three-Dimensional Printing for Complex Toe-to-Hand Reconstruction.

BACKGROUND: Microsurgical toe-to-hand transplantation is a reasonable salvage procedure after failed replantation, though no consensus exists on proper donor toe length for restoration of hand function and optimal donor flap needed for recipient site healing. The purpose of this study was to introduce a novel technique for preoperative planning in complicated toe-to-hand reconstruction and to assess feasibility in four cases. METHODS: Computed tomography (CT) angiography was used to map donor site vasculature, whereas CT data were used to create three-dimensional (3D) soft tissue and skeletal models for injured and uninjured hands. Based on the reformatted model (mirror of uninjured hand), soft tissue and finger skeleton models were generated using a 3D printer. An adhesive plaster model was placed on the donor site to determine osteotomy level and incision markings. The skeletal model was used to determine the length of the donor foot resection. Four complex amputation cases were included to illustrate clinical feasibility and early functional and cosmetic outcomes. RESULTS: In all four cases, thumb and fingers were reconstructed successfully and all flaps survived. No arterial or venous thrombosis or major donor morbidity were observed. Functional and cosmetic outcomes were satisfactory with similarly satisfactory static two-point discrimination, key pinch and grip strength, and Michigan Hand Outcomes Questionnaire scores. CONCLUSION: This novel microsurgical toe-to-hand reconstruction methodology, as introduced in this study, showed promising functional and cosmetic outcomes. Application of this technique in complex hand injuries has the potential to increase surgical efficiency, minimize procedural morbidity, and improve reproducibility.

Repair of minor tissue defect in hand by transfer of free tissue flap from the toe.

BACKGROUND: To introduce our experience of using the free neurovascular flap from great and second toe. METHODS: Thirteen patients (fifteen fingers) sought surgical treatment for soft tissue defects of the hand at our medical institution between March 2006 and September 2009. In two patients, fibular side skin-nail flaps of great toe were applied to cover the dorsal defect of distal thumb. In twelve, the treatment was carried out for the pulp defect of finger with fibular side flap of great toe or tibial side flap of second toe. In one, the treatment was carried out for the defect of distal middle with composite flap with distal digital bone of second toe. RESULTS: All flaps survived. The average subjective satisfaction score was 8.08 (range 4-10). Nine patients (69%) experienced cold intolerance, and 2 patients (15%) dysesthesia. The Semmes-Weinstein sensitivity score was between 3.47and 4.72 on the flap, and 0-4.18 on the donor site. The mean two-point discrimination was 6.8 mm (range 4-12). Grip strength was 10% less than in the unaffected hand. The proximal interphalangeal mobility loss was less than 15 degrees. CONCLUSIONS: Our results indicated that these free flaps from toe are useful for patients with a small soft-tissue defect in hand.