ObjectiveTo review the recent progress in the application of three-dimensional digital technology in knee arthroplasty. MethodsThe relevant literature at home and abroad about the three-dimensional digital technology in the applications of knee arthroplasty in recent years was extensively reviewed. ResultsThe three-dimensional digital technology can obtain arthroplasty knee morphology and biomechanics, and can estimate preoperative planning osteotomy and the sizes of prostheses, so it can guide knee arthroplasty precisely. ConclusionThree-dimensional digital technology can reduce the operation error, improve the operation precision, and improve the effectiveness in knee arthroplasty.
Objective To investigate the effectiveness of the digital technology in repairing tiny hand wounds with superficial lateral sural artery perforator flap. Methods Between August 2013 and October 2016, 10 cases of tiny hand wounds were treated with the superficial lateral sural artery perforator flap. There were 6 males and 4 females, aged 19 to 47 years (mean, 31.2 years). The causes included crushing injury by machine in 6 cases, traffic accident injury in 3 cases, and electric burning injury in 1 case. The location of the soft tissue defect was the first web in 2 cases, the thumb pulp in 3 cases, the index finger pulp in 1 case, the dorsal palms in 3 cases, and the dorsum of finger in 1 case. The time from injury to hospitalization was 4 hours to 10 days (mean, 3.5 days). The size of wound was from 4 cm×3 cm to 8 cm×7 cm. All defects were associated with exposure of tendon and bone. CT angiography (CTA) from aortaventralis to bilateral anterior and posterior tibial arteries was performed before operation, and the appropriate donor site as well as perforator was selected. Then the CTA data were imported into the Mimics15.0 software to reconstruct the three dimensional structure of the perforator artery, bone, and skin; according to flap size, the flap design and harvesting process were simulated. The flap was obtained on the basis of preoperative design during operation. The size of flaps varied from 5 cm×4 cm to 10 cm×8 cm. The donor site was sutured directly in 9 cases and repaired with skin grafting in 1 case. Results Superficial medial sural artery peforator was cut in 3 patients whose superficial lateral sural artery was too narrow, and the flaps were obtained to repair defects smoothly in the others. Venous crisis occurred in 1 flap, which survived after exploration of the vessel, thrombus extraction, and thrombolysis; the other flaps survived successfully. All wounds and incisions healed by first intention. All cases were followed up 3-18 months (mean, 10 months). The flaps had good shape. At last follow-up, the results were excellent in 6 cases, good in 3 cases, and fair in 1 case according to total active motion (TAM). Conclusion The preoperative individualized design of the superficial lateral artery perforator flap can realize through CTA digital technology and Mimics15.0 software; it can reduce the operation risk and is one of better ways to repair the tiny hand wounds.
Objective To investigate the feasibility and application value of digital technology in establishing the micro-vessels model of cross-boundary perforator flap in rat. Methods Twenty 8-week-old female Sprague Dawley rats, weighing 280-300 g, were used to established micro-vessels model. The cross-boundary perforator flaps of 10 cm×3 cm in size were prepared at the dorsum of 20 rats; then the flaps were suturedin situ. Ten rats were randomly picked up at 3 and 7 days after operation in order to observe the necrosis of flap and measure the percentage of flap necrosis area; the lead-oxide gelatin solution was used for vessels perfusion; flaps were harvested and three-dimensional reconstruction of micro-vessel was performed after micro-CT scanning. Vascular volume and total length were measured via Matlable 7.0 software. Results The percentage of flap necrosis area at 3 days after operation was 19.08%±3.64%, which was significantly lower than that at 7 days (39.76%±3.76%;t=10.361, P=0.029). Three-dimensional reconstruction via the micro-CT clearly showed the morphological alteration of micro-vessel of the flap. At 3 days after operation, the vascular volume of the flap was (1 240.23±89.71) mm3 and the total length was (245.94±29.38) mm. At 7 days after operation, the vascular volume of the flap was (1 036.96±88.97) mm3 and the total length was (143.20±30.28) mm. There were significant differences in the vascular volume and the total length between different time points (t=5.088, P=0.000; t=7.701, P=0.000). Conclusion The digital technology can be applied to visually observe and objectively evaluate the morphological alteration of the micro-vessels of the flap, and provide technical support for the study of vascular model of flap.
Objective To evaluate the effectiveness of precise orthormorphia of tibial angulation deformity and shortening deformity by using digital technology combined with external fixator. Methods Twenty-six cases of tibial angulation deformity combined with shortening deformity were treated between June 2012 and August 2016, including 12 males and 14 females aged from 1 to 19 years with an average age of 16.5 years. There were 6 cases of congenital patella pseudoarthrosis, 1 case of fibrous dysplasia of femur and tibia, 3 cases of limb shortening deformity caused by infantile paralysis, 16 cases of fracture malunion. Limb shortening was 1.5-9.5 cm (mean, 6.2 cm) before operation. The deformity from three-dimensional perspective was analysed by digital technology, the surgical procedures of lengthening and osteotomy was simulated, the navigation templates were completed with computer aided design (CAD) and three-dimensional printing, and the external fixator was used to assist the lengthening of the tibia. X-ray films were regularly reviewed after operation to observe the new bone remolding, limb lengthening, load bearing line of lower limb, and recurrences of angulation. Results All the patients were followed up 14-48 months (mean, 18.8 months). There was only 1 case of superficial pin site infection which was cured with oral antibiotics and pin site care with mild disinfectants, and no complication such as bone nonunion, equines deformity, or vascular nerve injury occurred. The deformity of tibia and load bearing line of lower limb had been completely recovered according to postoperative X-ray films at 1 week. All the cases achieved perfect limb length as with preoperative design. The bone mineralization time was 12-20 weeks (mean, 11.6 weeks), the external fixator removal time was 18-26 weeks (mean, 14.9 weeks), and the healing index was 21-78 d/cm (mean, 63.4 d/cm). The postoperative flexion range of the injured limb was 15° less than the unaffected extremity in 1 case, and the situation was improved significantly after some physical manipulation and exercise, who completed the limb lengthening and achieved the expected effectiveness finally. Conclusion Precise orthormorphia of tibial deformity by using digital technology, and limb lengthening with the aid of external fixator can achieve good effectiveness with good reliability, invasiveness, and precision.
ObjectiveTo study the effectiveness of digital technique in repairing of heel wound with peroneal artery perforator propeller flap.MethodsBetween March 2016 and March 2019, the heel wounds of 31 patients were repaired with the peroneal artery perforator propeller flaps. There were 21 males and 10 females, with an average age of 36 years (range, 12-53 years). Seventeen patients were admitted to hospital in emergency after trauma, the time from injury to admission was 6.0-12.5 hours, with an average of 8.5 hours; 14 patients were chronic infectious wounds and ulcer. The wound area ranged from 5 cm×4 cm to 12 cm×8 cm. Before flap repair, CT angiography (CTA) data of lower extremity was imported into Mimics19.0 software and three-dimensional reconstruction of peroneal artery perforator and skin model, accurate location of perforator, accurate design of perforator flap, and simulated operation according to the defect range and location were obtained.ResultsThe origin and course of peroneal artery perforator, the position of perforator, the diameter of perforator, and the maximum length of the naked perforator were determined based on the three-dimensional model. There was no significant difference in locating point of perforator, diameter of perforator, maximum length of naked perforator between the pre- and intra-operative measurements (P>0.05). The position of the lower perforator of the peroneal artery were on the posterolateral lateral ankle tip (5-10 cm) in 31 cases. The total incidence of perforating branches within 10 cm on the tip of lateral malleolus was 96.9%, and the length of vascular pedicle was (3.44±0.65) cm. The flap removal and transposition in 31 patients were successfully completed. The average operation time was 45 minutes (range, 30-65 minutes). After operation, vein crisis and partial necrosis occurred in 4 cases and 3 cases, respectively, which were survived after symptomatic treatment. All the grafts survived and the incisions healed by first intention. All the patients were followed up 3-18 months, with an average of 12 months. At last follow-up, according to the American Orthopaedic Foot and Ankle Society (AOFAS) score, 17 cases were excellent, 11 cases were good, and 3 cases were fair, and the excellent and good rate was 87.5%.ConclusionThe digital technique can improve the accuracy of perforator localization and the design of peroneal artery perforator propeller flap, and reduce the difficulty of operation, and the risk caused by the variation of vascular anatomy.