RESUMO
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.
RESUMO
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.
RESUMO
PURPOSE: We hypothesized that a side-to-side (STS) tendon repair has biomechanical characteristics that match those of a Pulvertaft (PT) weave. METHODS: Thirty extensor tendons were harvested (4 extensor digitorum communis and 1 extensor indicis proprius from 6 cadaver arms). Three hand surgery fellows with similar backgrounds of training under the same conditions and precise standardized technique performed the repairs (5 PT and 5 STS per surgeon). After the repairs, the tendons were passed through a graft-sizing guide to determine bulk and results were expressed as a repaired versus native diameter ratio. The specimens were then tested for ultimate strength and fatigue properties. Failure type and mechanical properties were recorded and compared with those of the native tendon. RESULTS: The average peak force to failure was 93 ± 20 N for the STS and 62 ± 32 N for PT group. Relative strength ratio (repair strength compared with native tendon strength) was 37% ± 21% for the STS and 22% ± 11% for the PT group. In the STS group, all failures occurred as a result of tissue failure; however, in the PT, suture failures occurred in 3 tendons before tissue failure. The mean bulk ratio of the repaired site versus native proximal tendon was 37 ± 14% and 40% ± 22% more for the STS and PT groups, respectively. These values for native distal tendon were 28% ± 9.9% and 26% ±24 %, respectively for STS and PT repair. Furthermore, the bulk of the repaired site for the STS and PT groups was 4.2 ± 0.50 and 4.7 ± 1.2 mm, respectively. CONCLUSIONS: Side-to-side repair technique showed superior biomechanical properties while demonstrating comparable repair bulk of the tendon coaptation compared with the Pulvertaft weave. CLINICAL RELEVANCE: The results of this study may help guide a surgeon's choice of repair technique when addressing tendon injuries or tendon transfers.