Walking and running plantar pressure analysis before and after resection of tarsal coalition

BACKGROUND: Conservative treatment failure in symptomatic tarsal coalition usually mandates bar resection as a preferred operative alternative. The outcome of this procedure generally has been assessed by clinical measures. The purpose of our study was to evaluate whether plantar pressure distribution is normalized after bar resection. METHODS: This study compared three groups: nine candidates for resection of tarsal coalition, nine patients between 2 and 4 years after bar resection (not the same patients who were candidates for resection), and nine control subjects. The ankle and hindfoot were evaluated according to the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale. Mean plantar pressure and mean normalized impulses were calculated during walking and running. RESULTS: Significantly higher AOFAS scores were demonstrated in the postoperative group compared with the preoperative group (p<0.01). Medial midfoot pressures demonstrated the most consistent differences between groups. Preoperative feet had significantly higher medial midfoot pressures compared with the control group both during walking and running. Feet that had resection did not demonstrate significantly higher medial midfoot pressures during walking compared with the control group. However, during running, this segment's pressures were significantly higher both in preoperative (p=0.000) and in postoperative (p=0.023) feet compared with the control group. Heel segments revealed decreased pressures laterally both in preoperative feet and in postoperative feet compared with the control group. CONCLUSIONS: Running demonstrates that normal plantar pressures are not recreated after resection of tarsal coalition. However, close to normal walking pressure distribution is consistent with the favorable clinical outcome observed in most patients after bar resection. CLINICAL RELEVANCE: Regaining full recreational activity after resection of a tarsal coalition, i.e. running, may have implications on abnormal foot loading and torque, thus promoting degenerative changes in the subtalar and adjacent joints.     

跗骨间骨桥临床诊断与治疗研究进展

目的总结跗骨间骨桥临床诊断与治疗研究进展。方法查阅近年关于跗骨间骨桥的诊断及治疗相关文献,进行综述分析。结果跗骨间骨桥是足部跗骨间桥接组织,常见类型为跟距骨桥和跟舟骨桥。跟舟骨桥在后足斜位X线片即可确诊,多数跟距骨桥需CT扫描确诊,MRI可用于软骨性和纤维组织性骨桥的诊断。石膏固定对于有症状患者是首选治疗方法;对于治疗失败未发生退行性变患者,切除骨桥可取得良好治疗效果。单纯距下关节融合可用于治疗跟距骨桥切除失败的患者,对于距下关节融合失败和跟舟骨桥切除失败的患者可行三关节融合术。微创治疗应严格掌控手术适应证。结论跗骨间骨桥诊断方法较为明确,应将临床表现和影像学检查结合以提高诊出率。手术治疗指征尚存在争议,仍需基于随机对照试验的长期随访报道。     

Distribution of in-shoe dynamic plantar foot pressures in professional football players

At two football venues, 35 professional football players, aged 17 to 30, took part in a study. The aim was to compare in-shoe dynamic plantar foot pressures between football boots and trainers by investigating relationships between area, force and pressure. The study showed a decreased plantar foot area of 9.3% in the left football boot when compared to the trainer and 7.2% in the right. Maximum pressure was 35% higher in football boots when compared to trainers. Similarly, mean pressure was 27.6% higher in football boots. The study suggests that a reduced football boot surface area may be responsible for the increased forces and pressures within football boots when compared to trainers.     

Computed tomography in suspected tarsal coalition. Examination of 26 cases

Coronal plane computed tomography (CT) was performed in 26 consecutive patients with clinical suspicion of tarsal coalition. Twenty patients had plain CT and 6 had CT talocalcaneonavicular arthrography. Fifteen patients were found to have coalition. Of these 15 patients, 12 had talocalcaneal coalition (9 bilateral, 3 unilateral), 2 patients had combined talocalcaneal and calcaneonavicular coalitions, and the remaining patient had bilateral calcaneonavicular coalitions. Surgical findings corroborated the CT diagnosis in 9 patients with talocalcaneal coalition and in 2 patients with calcaneonavicular coalition. Ossified talocalcaneal coalitions were found in children aged 6 and 10 years, i.e., well below the conventionally stated age range of 12 to 16 years. CT is the investigation of choice in suspected tarsal coalition if plain radiography is not diagnostic. CT arthrography did not generally provide further information, but may be useful if plain CT is equivocal.     

Bilateral coexistent calcaneonavicular and talocalcaneal tarsal coalition: a case report.

Tarsal coalition refers to a union of two or more tarsal bones. The union may be fibrous, cartilaginous, or bony. The most common sites of tarsal coalition reported in the literature are the calcaneonavicular, the talocalcaneal, and, less commonly, the talonavicular areas. Bilateral coexistent multiple tarsal coalitions are a rare occurrence. The authors present a case report of a 17-year-old boy with bilateral coexistent calcaneonavicular and talonavicular bars. The diagnosis was established by radiographs and CT scanning. The patient was treated conservatively with immobilization of the foot in a below-knee walking plaster cast followed by the use of an orthosis with a lateral iron and a medial T strap. The patient was pain-free at 2-year follow-up.     

Effects of medializing calcaneal osteotomy on Achilles tendon lengthening and plantar foot pressures

Posterior tibial tendon insufficiency, or adult acquired flatfoot deformity, involves collapse of the longitudinal arch of the foot with ensuing changes in the bony architecture of the foot as well. While it is generally accepted that a medializing calcaneal osteotomy (MCO) is a very useful treatment for restoring the fallen arch, questions regarding the effects of this procedure upon plantar foot pressures and Achilles tendon length changes need to be answered. This study focuses on changes in plantar foot pressures and Achilles tendon length as the result of performing a MCO. Fourteen fresh-frozen cadaver legs were used to test the effects of MCO on Achilles tendon length changes 2 cm proximal to the Achilles tendon insertion on the calcaneus. Differential variable reluctance transducers were anchored in ventromedial, dorsomedial, dorsolateral, and ventrolateral positions of the Achilles tendon at the aforementioned level. The effects of the MCO on plantar foot pressures were assessed simultaneously using the Tekscan HR Mat. Axial loading (100 lbs) of each specimen was performed in neutral and dorsiflexion (15 degrees). Data were gathered for Achilles tendon length changes and plantar foot pressures for three trials in both the neutral and dorsiflexed positions. A medializing calcaneal osteotomy (1 cm medial translation) was then performed and testing was repeated in the fashion outlined heretofore. Analysis of the data revealed that there was no significant increase in Achilles tendon length as a result of the MCO. The data also showed that average pressure over the first and second metatarsal regions of the forefoot decreased significantly after MCO. At the same time there was a significant increase in average pressure over the medial and lateral aspect of the heel. These findings suggest that the Achilles tendon aids in inversion of the forefoot without undergoing a significant increase in length change of Achilles tendon fibers in any of the regions tested.     

Concomitant arterial and venous reconstruction with resection of lower extremity sarcomas

INTRODUCTION: Limb salvage can now be achieved in many cases of lower extremity sarcoma. Obtaining disease-free margins may require resection of adjacent vascular structures. We present our experience with a consecutive series of patients undergoing resection of lower extremity sarcomas en block with the artery and vein, focusing on the mid- and long-term outcomes of their vascular reconstruction. METHODS: Records were reviewed retrospectively for patient age, tumor location and type, procedure, and early and late outcomes. Between 1991 and 2004, 10 children (mean age 12 years, range 6-18 years) and 9 adults (mean age 48 years, range 24-73 years) underwent wide resection of lower extremity sarcomas to include the involved arterial and venous segments. All children had bone sarcomas, and because of their skeletal immaturity, they were treated with rotationplasty--a type of intercalary amputation that removes the distal thigh, knee, and proximal tibia while preserving the distal leg and foot. In rotationplasty, the distal residual limb is preserved, rotated 180 degrees, and attached to the thigh, positioning the ankle at the level of the former knee joint. In these cases, the residual vessels were reconstructed by primary anastomosis. All of the adults except one had soft tissue sarcomas; the resected vessels were reconstructed with contralateral saphenous vein. In all cases, the operative approach included shunting of artery and vein during tumor removal and orthopedic reconstruction. RESULTS: The mean follow-up was 5.7 years. Three patients died of metastatic disease, and one died from a postoperative pulmonary embolism. No patient had local recurrence. Two patients ultimately required above-knee amputation: one child for tissue loss secondary to reperfusion injury, and one adult because of graft thrombosis secondary to progression of peripheral arterial disease. Two patients required early re-exploration for perioperative graft thrombosis. Both required replacement of saphenous vein conduits with polytetrafluoroethylene (PTFE) prosthetic graft; one of the PTFE grafts became infected. CONCLUSIONS: Limb salvage can be achieved in the majority of patients who have lower extremity sarcomas even when en bloc resection includes the artery and vein. Intraoperative shunting can limit ischemia and is especially useful when immediate vascular repair is delayed by orthopedic reconstruction. The long-term patency rate of the reconstructed vessels is high. Saphenous vein is the preferred conduit when it is of adequate caliber.     

Treatment of the muscles in primary amputation of the lower extremity

Histological and histochemical investigations of muscles in 18 patients have shown that when performing primary amputations of lower extremities according to the type of surgical treatment in the wound stump there necessarily remains muscular tissue of lower viability with necrotic areas.     

Effect of callus removal on peak plantar pressures

Peak plantar pressure from 15 subjects (36 calluses) was recorded using a Musgrave Footprint. Pressures were measured at the site of each callus before and after removal with a scalpel. Recordings were also taken from five comparison subjects without callus. No significant difference was found in peak pressure before and after callus removal (P>0.05). However, the comparison group were found to have 25% lower pressures than the subject group (P<0.05). This research suggests that callus does not cause elevated peak pressure and that its removal should be accompanied by pressure relief or redistribution to reduce the underlying high pressure.     

Effect of the shoe on plantar foot pressures

The bare foot plantar pressures were compared to in-shoe pressure measurements in 11 normal male volunteers using the EMED system. Shoes diminished pressures and forces in most areas under the foot except the medial forefoot. The hallux showed less force, a smaller contact area and a reduced contact time. Therefore a shoe can interfere with the toe-off mechanism. There was no difference between various types of shoes with rubber and leather soles. Heavier subjects tended to put less weight on the medial forefoot.     

Electromyographical analysis of selected lower extremity muscles during 5 unilateral weight-bearing exercises

STUDY DESIGN: Prospective single-group repeated-measures design. OBJECTIVES: To quantify electromyographic (EMG) signal amplitude of the gluteus maximus, gluteus medius, vastus medialis oblique, and biceps femoris during 5 unilateral weight-bearing exercises. BACKGROUND: Using normalized EMG (NEMG) signal amplitude as a measure of muscle activation and, therefore, an estimate of exercise intensity, the relative contributions and interaction of the hip and thigh muscles during unilateral weight-bearing exercise can be examined. With regard to potential efficiency for strengthening, data on the amount of EMG signal amplitude for these 4 muscles during commonly used exercises are limited. METHODS AND MEASURES: Twenty-three healthy, asymptomatic subjects (16 men, 7 women; mean +/- SD age, 31.2 +/- 5.8 years) participated. A repeated-measures analysis was conducted using general linear models. The percent maximum voluntary isometric contraction was measured within each subject across 4 muscles during 5 exercises for 2 separate trials. Effect sizes of pairwise comparisons were computed. RESULTS: Statistically significant differences were noted in the amount of mean NEMG signal amplitude for the 4 muscles across the 5 exercises. A similar recruitment pattern between muscles was observed across all exercises. CONCLUSION: Even though all muscles except the biceps femoris demonstrated mean NEMG signal amplitudes sufficient for strengthening, the wall squat produced the highest levels of activation and should be considered the most efficient for targeting any of the 4 muscles or for training a cooperative effort among the muscles.     

应用单侧纵轴动力外固定器矫正下肢畸形

作者于１９８９年１０月～１９９４年１２月，采用截骨矫形加单侧纵轴动力外固定器固定的方法，治疗不同类型的下肢畸形６０例７８个部位。结果显示：７７处截骨均为一期愈合，１处延迟愈合；针孔感染率为０．６％。平均随访时间２．５年，全部病例肢体畸形矫正满意，关节功能恢复好。作者认为，应用本固定器创伤小、操作简单、固定牢固。由于具有弹性固定作用，可促进骨痂生长、加速骨愈合，对关节功能影响小，并发症少，最突出的优点是可将肢体畸形矫正至理想角度。     

基于下肢肌肉高频超声及剪切波弹性成像参数评估皮肌炎

目的 观察下肢肌肉高频超声（HFUS）及剪切波弹性成像（SWE）参数用于评估皮肌炎（DM）的价值。方法 前瞻性对19例DM患者（DM组）及20名健康体检者（对照组）行下肢肌肉HFUS及SWE检查,对比2组双侧股外侧肌及腓肠肌外侧头肌肉回声、厚度及剪切波速度（SWV）,绘制受试者工作特征曲线,计算曲线下面积（AUC）,观察各超声参数评估DM的效能。结果 DM组肌肉回声为1分者占比、双侧腓肠肌外侧头肌肉厚度、双侧股外侧肌及腓肠肌外侧头SWV均低于对照组（P均＜0.05）。双侧股外侧肌及左侧腓肠肌外侧头SWV用于评估DM效能优异（AUC为0.932～0.968）,双侧腓肠肌外侧头厚度及右侧腓肠肌外侧头SWV评估DM的效能良好（AUC为0.784～0.884）,而肌肉回声用于评估DM的效能一般（AUC=0.658）。结论 下肢肌肉HFUS及SWE参数可用于评估DM,尤以SWE参数价值相对较高。