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OBJECTIVE@#To design customized titanium alloy lunate prosthesis, construct three-dimensional finite element model of wrist joint before and after replacement by finite element analysis, and observe the biomechanical changes of wrist joint after replacement, providing biomechanical basis for clinical application of prosthesis.@*METHODS@#One fresh frozen human forearm was collected, and the maximum range of motions in flexion, extension, ulnar deviation, and radialis deviation tested by cortex motion capture system were 48.42°, 38.04°, 35.68°, and 26.41°, respectively. The wrist joint data was obtained by CT scan and imported into Mimics21.0 software and Magics21.0 software to construct a wrist joint three-dimensional model and design customized titanium alloy lunate prosthesis. Then Geomagic Studio 2017 software and Solidworks 2017 software were used to construct the three-dimensional finite element models of a normal wrist joint (normal model) and a wrist joint with lunate prosthesis after replacement (replacement model). The stress distribution and deformation of the wrist joint before and after replacement were analyzed for flexion at and 15°, 30°, 48.42°, extension at 15°, 30°, and 38.04°, ulnar deviation at 10°, 20°, and 35.68°, and radial deviation at 5°, 15°, and 26.41° by the ANSYS 17.0 finite element analysis software. And the stress distribution of lunate bone and lunate prosthesis were also observed.@*RESULTS@#The three-dimensional finite element models of wrist joint before and after replacement were successfully constructed. At different range of motion of flexion, extension, ulnar deviation, and radial deviation, there were some differences in the number of nodes and units in the grid models. In the four directions of flexion, extension, ulnar deviation, and radial deviation, the maximum deformation of wrist joint in normal model and replacement model occurred in the radial side, and the values increased gradually with the increase of the range of motion. The maximum stress of the wrist joint increased gradually with the increase of the range of motion, and at maximum range of motion, the stress was concentrated on the proximal radius, showing an overall trend of moving from the radial wrist to the proximal radius. The maximum stress of normal lunate bone increased gradually with the increase of range of motion in different directions, and the stress position also changed. The maximum stress of lunate prosthesis was concentrated on the ulnar side of the prosthesis, which increased gradually with the increase of the range of motion in flexion, and decreased gradually with the increase of the range of motion in extension, ulnar deviation, and radialis deviation. The stress on prosthesis increased significantly when compared with that on normal lunate bone.@*CONCLUSION@#The customized titanium alloy lunate prosthesis does not change the wrist joint load transfer mode, which provided data support for the clinical application of the prosthesis.
Assuntos
Humanos , Osso Semilunar/cirurgia , Análise de Elementos Finitos , Titânio , Articulação do Punho/cirurgia , Membros Artificiais , Amplitude de Movimento Articular , Fenômenos BiomecânicosRESUMO
Objective:To investigate the effect of flap combined with 3D printed microporous titanium(tantalum)prosthesis in the treatment of lower extremity soft tissue defect with large bone defect.Methods:From January 2019 to December 2020, 2 patients with large soft tissue defects on dorsal foot together with large metatarsal bone defect and 4 patients with soft tissue defects of calf with large tibial bone defect were treated. The areas of soft tissue defect were 5.0 cm×8.0 cm-15.0 cm×10.0 cm. The length of the bone defect were 3.8 cm to 7.0 cm, 5.75 cm in average. In the first stage, metatarsal bone defect or tibial bone defect was filled with vancomycin blended bone cement, meanwhile, soft tissue defect was repaired with anterolateral femoral flap(ALTF) with vascular anastomosis in 2 cases of feet, and local fascia flap was trans-positioned in 4 cases of lower extremity defects. The sizes of repairing flap were 6.0 cm×8.5 cm-16.0 cm×11.0 cm. Two to 7 months after the initial surgery, the customer designed microporous titanium prostheses were used(5 cases with microporous titanium and 1 with microporous tantalum) to repair the bone defects. The wound healing, the integration of metatarsal and tibial fractures with 3D printed microporous titanium(tantalum) prostheses, and the walking condition were observed after surgery. The follow-up lasted from 6 to 25 months, with an average of 12.7 months.Results:The wound healing in 5 patients was good. The patients stood on the foot in 2 months after surgery, started to walk with the assistance of crutch in 3 months after surgery, and took walk without assistance in 5-6 months after surgery. Good osseous integration were achieved. One diabetic patient had infection of foot wound 3 months after surgery. After removal of microporous titanium prosthesis and replacement of vancomycin blended interstitial substance of bone cement, the wound healed and the patient resumed walking.Conclusion:It is an effective method to encourage the patients to take early ambulation after the surgery for lower extremity soft tissue defect with large bone defect that was repaired by a flap and 3D printed microporous titanium(tantalum)prosthesis. Further observations are required to investigate the long-term efficacy, and the reduction of prosthesis infection rate requires further exploration.
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A patient suffered a sustained soft tissue necrosis and infection at the radial interphalangeal joint of left thumb after laser nevus removal. He was treated in the Department of Orthopaedics, No. 920 Hospital of Joint Logistic Support Force of Chinese People's Liberation Army in February 2020. CTA combined with digital technology of Mimics software was used to accurately locate the perforator of posterior tibial artery septal perforator flap at the appropriate part of the calf and the super flap (1.20 cm×0.80 cm×0.46 cm) for the repair was designed. After 1 year of follow-up, the left thumb flap had no swelling with a satisfactory texture and appearance. The sensory recovered to S 3, and the left thumb movement was completely normal. Only a linear scar remained at the donor site of the calf.
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Objective:To explore the treatment of pressure sores in different parts of the buttocks.Methods:From May, 2005 to March, 2020, 170 (157 patients) pressure sores in different parts of buttocks were treated. Eighty-two pressure sores located at sacrococcyx, 52 at ischial tuberosity, 24 at greater trochanter (without hip joint exposure) and 12 at femoral greater trochanter with exposure of the hip joint. Flaps were used to repair the pressure sores. ①Seventy-one sacrococcygeal pressure sores were repaired by the gluteal epithelial neurovascular flap; ②10 (10 patients) sacrococcygeal and 42 (36 patients) sciatic tubercle pressure sores were repaired by the posterior femoral neurovascular flap; ③24(24 patients) femoral trochanter pressure sores and 1(1 patient) sacrococcygeal pressure sore were repaired by the tensor fascia lata myocutaneous flap; ④2 (2 patients) sciatic tubercle pressure sores were repaired by the gracilis myocutaneous flap; ⑤12 (10 patients) femoral trochanter pressure sores were with hip joint exposure treated with hip joint amputation; ⑥8 (8 patients) pressure sores at ischial tuberosity were treated with VSD. The pressure sores were measured at 5.0 cm×8.0 cm-15.0 cm×30.0 cm, and the flaps were sized 10.0 cm×12.0 cm-17.0 cm×32.0 cm. The follow-up was conducted in 2 methods: visit of outpatient clinic by patients and WeChat distanced interview by medical staff.Results:The gluteal epithelial neurovascular flaps, tensor fasciae lata flaps, gracilis myocutaneous flaps and posterior femoral neurovascular flaps all survived; 4 of 10 posterior femoral neurovascular flaps had partial necrosis and healed after dressing change. A total of 139 patients were treated by flap repair, of which 136 pressure sores healed, except 1 sacrococcygeal pressure sore and 1 femoral greater trochanter pressure sore did not heal because the patient was in old age, long-term hypoproteinaemia and anaemia, and 1 ischial tubercle pressure sore failed to heal due to osteomyelitis osteomyelitis. Ten pressure sores at femoral greater trochanter decubitus with hip joint exposure treated by hip joint amputation and 8 pressure sores at ischial tubercle decubitus treated by simple insertion of VSD were all healed. The follow-up period was 0.5-15.0 years, 7.5 years in average. The results of follow-up showed that pressure sores healed without recurrence in 154 patients, but failed to heal in 3 patients.Conclusion:The gluteal epithelial neurotrophic vascular flap has reliable blood supply and is simple to harvest, and it is a good flap to repair sacrococcygeal pressure sores. The tensor fascia lata myocutaneous flap has reliable blood supply and is simple to harvest, hence it is a good flap to repair greater trochanteric pressure sores. Transposition of the posterior femoral cutaneous nerve nutrient vessel flap or the V-Y advancement flap is simple and effective in repair of the sciatic tuberosity pressure sores. However, it is not recommended to apply the transposition of posterior femoral cutaneous nerve nutrient vessel flap in repair of the sacrococcygobtaineal pressure sore, because it would cause a necrosis at the distal part of the flap. When a greater trochanteric pressure sore coexists with an expose of hip joint, the hip joint can be dissected. For the pressure sore at ischial tuberosity, and if there is a small wound with a large internal cavity, it can be treated with simple insertion of VSD.
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Objective:To compare the clinical effects of 4 kinds of neurocutaneous perforator flap with vascular anastomosis for repair of hand and foot wounds.Methods:From January, 2005 to September, 2019, 112 patients with hand and foot wounds were treated, there were 78 cases of fingers, 11 cases of first web, 5 cases of palm, 6 cases of hand and 12 cases of foot. The defect area was 2.0 cm×1.5 cm-21.0 cm×12.0 cm. All 112 cases were repaired by neurocutaneous perforator flaps anastomosed with blood vessels. Types of flap were applied: Radial collateral artery perforator flap (with posterior cutaneous nerve of forearm) in 30 cases. The flap area was 5.0 cm×2.0 cm-13.0 cm×6.0 cm. Superficial peroneal artery flap (without superficial peroneal nerve) anastomosed with blood vessels in 15 cases. The flap area was 2.5 cm×2.0 cm-9.0 cm×6.0 cm. Lateral superficial sural artery perforator flap (with superior sural cutaneous nerve) in 26 cases. The flap area was 2.5 cm×1.8 cm-7.0 cm×5.0 cm. Peroneal artery perforator flap (with middle and lower sural nerve) in 41 cases. The flap was harvested with area of 2.5 cm×1.8 cm-23.0 cm ×14.0 cm to repair the wounds of feet, back of hands, first web, palm and fingers. CTA images were observed in 40 clinical patients, and the occurrence rate of radial collateral artery, superficial peroneal artery, superficial lateral sural artery, and peroneal artery were measured. Anastomosis cutaneous nerve in 97 cases, and no cutaneous nerve anastomosis 15 cases (superficial peroneal artery flap).Results:The peroneal artery perforator flap (41 cases) and radial collateral artery perforator flap (30 cases) were harvested. The incidence of perforator vessels was both 100%, and incidence of superficial sural artery was 80.8% (21/26 cases). In the other 19.2% (5/26 cases), the superficial medial sural artery was replaced by too thin vessels. The utilization rate of superficial peroneal artery was 60.0% (9/15 cases), the other 40.0% (6/15 cases) were converted to peroneal artery perforator flap. All flaps survived except 1 case of superficial perforator flap of lateral sural artery, which underwent necrosis at the distal end and healed after dressing change. One hundred and one cases were followed-up, including 90 cases for repairing soft tissue defects in hands and 11 cases in feet. The followed-up time ranged from 12 to 120 months, with an average of 36.6 months. There were 40 cases with excellent function, 45 cases with good function and 5 cases with fair function. There were 78 cases of cutaneous nerve anastomosis of hand flap, and the sensory function was above S 3 level. There were 12 cases without anastomosis of cutaneous nerve of hand flap, and the sensory function reached S 3 level in 3 cases and S 2 level in 9 cases. In 11 cases, the cutaneous nerve was anastomosed to repair the soft tissue defect of the foot, and the sensory function was above S 3 level. The radial collateral artery perforator flaps were relatively bulky and needed to be treated by fat removal. The other 3 kinds of three flaps were not bulky. Conclusion:The perforating vessels of peroneal artery and radial accessory artery have larger diameter and easy to harvest. The superficial peroneal artery and the lateral superficial sural artery are relatively small in caliber, especially the superficial peroneal artery. Among the 4 kinds of cutaneous nerve nutrient vascular flaps, the radial accessory artery perforator flap was the most bloated. Sensory nerve innervation flaps were found in the upper segment of lateral sural cutaneous nerve, posterior forearm cutaneous nerve and middle and lower segment of sural nerve. The superficial peroneal artery perforator flap was accompanied by superficial peroneal nerve that did not send cutaneous branches into the flap. The upper segment of superficial peroneal nerve was only a passing nerve.
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Objective: To summarize the research progress of the artificial wrist joint prosthesis.