Plantar pressure distribution can reflect the force of several key points on foot while standing and walking. A comprehensive understanding of the plantar pressure distribution makes great sense in the following aspects:the understanding of the normal foot biomechanics and function, clinical diagnosis, measurement of disease extent, postoperative efficacy evaluation, and rehabilitation research. A simple plantar pressure measurement device was designed in this study. This paper uses FlexiForce flexible sensor to pickup plantar pressure signal and USB A/D board to do data acquisition. The data are transferred into a laptop and processed by a VB-based software which can display, remember and replay the data. We chose patients with hallux valgus and normal people to measure the pressure distribution and make contrast analysis of plantar pressure with this device. It can be concluded that people with hallux valgus have higher pressure on the second metatarsophalangeal joint and the distribution move outward. The plantar pressure of patients postoperative could be greatly improved compared to the preoperative. The function of this device has been confirmed.
The first metatarsophalangeal joint bending plays an important role in the foot movement. However, the existing researches mainly focused on the movement scope of the joint and the clinical treatments of related foot diseases. In order to investigate the effects of the first metatarsophalangeal joint bending on human walking gait stability, the present researchers recruited 6 healthy young men to perform the first metatarsophalangeal joint constraint (FM-JC) and barefoot (BF) walking tests. Data of the temporal and spatial parameters, the joint angles of lower limbs, the ground reaction forces (GRF) and utilized coefficients of friction (UCOF) were collected and analyzed. The results showed that, since hip and knee could produce compensation motions, the FMJC had no significant effects on waking gait, but the slip and fall probability increased significantly.
ObjectiveTo compare the dorsiflexion osteotomy (DO) and implant arthroplasty (IA) in terms of clinical and radiographic outcomes for patients with advaced Freiberg disease.MethodsA clinical data of 25 cases of Freiberg disease, who were admitted between July 2012 and July 2016 and met selection criteria, was retrospectively reviewed. According to the Smillie classification, all patients were classified as stage Ⅳ-Ⅴ. Among them, 13 cases were treated with DO (DO group) and 12 cases were treated with IA (IA group). No significant difference was found between the two groups in gender, age, side of the affected metatarsophalangeal (MTP) joint, location, Smillie classification, disease duration, and preoperative visual analogue scale (VAS) score, range of motion of the affected MTP joints, and the American Orthopedic Foot and Ankle Society (AOFAS) score (P>0.05). Total costs for index admissions were compared between the two groups. Clinical outcomes were evaluated in accordance with the VAS score, AOFAS score, and the range of motion of the affected MTP joints.ResultsAll incisions of the two groups healed by first intention. The follow-up time was 12-30 months (mean, 17 months) in DO group and 12-24 months (mean, 16 months) in IA group. The total cost of index admission was significantly higher in IA group than that n DO group (t=2.742, P=0.011). The AOFAS scores, VAS scores, and range of dorsiflexion and plantar flexion at last follow-up were significantly improved when compared with preoperative value in the two groups (P<0.05). There was no significant difference in all indexes between the two groups (P>0.05). X-ray film examination showed that the osteotomy healed within 8-12 weeks (mean, 9.5 weeks) after operation in DO group. None of the patients experienced internal fixator and implant related complications postoperatively.ConclusionDO and IA can provide significant improvement in pain and motion of the MTP joints for advanced Freiberg disease. But the DO may be the more economical method.
ObjectiveTo evaluate the effectiveness of lesion clearance combined with Ilizarov technique for the treatment of tophi in first metatarsophalangeal (MTP) joint with bone defect.MethodsBetween July 2016 and June 2018, 14 cases of tophi in the first MTP joint with bone defect were treated by lesion clearance combined with Ilizarov technique. There were 12 males and 2 females. The average age was 39.3 years (range, 22-60 years). The disease duration ranged from 5 to 15 years, with an average of 11.2 years. The tophi volume ranged from 2.5 cm×2.7 cm×2.2 cm to 5.2 cm×2.9 cm×2.4 cm. The X-ray films showed that the length of the bone defect ranged from 2.0 to 4.6 cm, with an average of 3.4 cm. Preoperative visual analogue scale (VAS) score was 7.6±0.9; American Orthopaedic Foot and Ankle Society (AOFAS) score was 47.5±4.3; short-form 36 health survey scale (SF-36) score was 79.7±4.7.ResultsThe incision primarily healed in 13 patients after operation. The skin necrosis at the edge of the incision occurred in 1 patient and recovered after symptomatic treatment. All 14 patients were followed up 12-16 months, with an average of 13.6 months. X-ray films showed that the first metatarsal column defects were repaired. The time of bone extension ranged from 2 to 6 weeks, with an average of 3.6 weeks. The time of bone healing ranged from 9 to 16 weeks, with an average of 11.2 weeks. During follow-up, no complication such as nerve, blood vessel, or tendon injury, needle tract infection, or stress fracture occurred. At last follow-up, VAS score was 1.4±0.5, AOFAS score was 86.6±4.8, and SF-36 score was 89.1±3.3, all of which were superior to preoperative scores, with significant differences (t=22.532, P=0.000; t=22.702, P=0.000; t=6.124, P=0.000).ConclusionLesion clearance combined with Ilizarov technique is a safe and effective method for the treatment of tophi in the first MTP joint with bone defect.
Objective To analyze the biomechanical changes of hallux valus after Swanson prosthesis-arthroplasty of the 1st metatarsophalangeal joint combined with osteotomy and bone grafting of the 1st metatarsal bone by three-dimensional finite element analysis, so as to provide data basis for studying the changes of foot morphology and physiological function after hallux valus correction surgery. Methods A 65-year-old female patient with severe hallux valus admitted in January 2013 was selected as the research object. The CT data of the right foot was obtained, and the three-dimensional finite element models before and after Swanson prosthesis-arthroplasty of the 1st metatarsophalangeal joint combined with osteotomy and bone grafting of the 1st metatarsal bone were established by Mimics10.01, Geomagic Studio, and ANSYS12.0 software. ANSYS 12.0 software was used for nonlinear static stress analysis, and the hallux valgus angle (HVA), the intermetatarsal angle (IMA), and the von Mises stress distributions of the forefoot plantar surface and the 1st to 5th metatarsal bones were observed before and after operation. ResultsThe HVA and IMA were 56.3° and 16.3° before operation and 9.2° and 9.8° after operation, respectively. Before operation, the stress on the forefoot was the largest in the 4th metatarsal head zone and the smallest in the 1st metatarsal head zone; the stress on the medial side of the forefoot was significantly smaller than that on the lateral side, and the center of forefoot pressure was located on the lateral side. After operation, the stress on the forefoot was the largest in the 1st metatarsal head zone and the smallest in the 5th metatarsal head zone; the stress on the lateral side of the forefoot was significantly smaller than that on the medial side, and the center of forefoot pressure was located on the medial side. Before operation, the stress of the 5th metatarsal bone was the largest, and the 1st metatarsal bone was the smallest. After operation, the stress of the 1st metatarsal bone was the largest, and the 4th metatarsal bone was the smallest. Conclusion Swanson prosthesis-arthroplasty of the 1st metatarsophalangeal joint combined with osteotomy and bone grafting of the 1st metatarsal bone can effectively correct hallux valgus and make HVA, IMA, and plantar pressure distribution close to normal. However, postoperative stresses of the 1st to 5th metatarsal bones elevate, which may lead to associated complications.