A Systematic Review of Plantar Plate Repair in the Management of Lesser Metatarsophalangeal Joint Instability

The plantar plate is a major structure that maintains metatarsophalangeal joint (MTPJ) stability and has only recently gained attention. Anatomic plantar plate repair can directly address the pathologic entity, rather than relying on indirect reduction of the MTPJ instability by osteotomy or tendon transfer techniques. The present report aimed to determine the effectiveness of plantar plate repair for the treatment of patients with lesser MTPJ instability. Different databases were searched using the guidelines in the Cochrane Handbook and recommendations from the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement. Six case series, describing 162 patients who had undergone plantar plate repair in conjunction with either Weil osteotomy or flexor digitorum longus transfer, were retrieved. Favorable outcomes were described in each of the studies included in the present systematic review. However, these results should be interpreted with caution because of the methodologic limitations and biases inherent in the included studies. More rigorous clinical investigations are required to fully understand the effectiveness of plantar plate repair for the management of lesser MTPJ instability.     

Calcaneocuboid Distraction Arthrodesis With Synthetic Bone Grafts: Preliminary Results of an Innovative Bone Grafting Procedure in 13 Patients

Calcaneocuboid distraction arthrodesis (CCDA) is regarded as an effective method for reconstructing adult-acquired flatfoot deformity. In the present study, we present our experience with newly developed rigid β-tricalcium phosphate wedges to treat CCDA to better understand the outcomes of this synthetic bone grafting procedure. A total of 13 feet in 13 patients underwent CCDA with synthetic bone grafts. One male (7.69%) and 12 females (92.31%), with a mean age of 65.07 ± 11.83 (range 36 to 77) years, were followed up for a mean duration of 32.76 ± 12.81 (range 18 to 55) months. Successful graft union was postoperatively obtained in 12 of the 13 feet (92.31%). The mean preoperative visual analog scale and American Orthopaedic Foot and Ankle Society scale score were 7.97 ± 1.52 (range 5.4 to 10) and 54.46 ± 14.72 (range 18 to 75), respectively. These scores improved to 1.52 ± 1.78 (range 0 to 6.2) and 85.46 ± 13.38 (range 50 to 97) postoperatively (p = .001 for both comparisons). On radiographic analysis, the talonavicular coverage angle, first metatarsal talar angle, calcaneal pitch, and heel alignment angle had significantly improved (p = .001, p = .028, p = .006, and p = .001, respectively). The use of bone graft substitutes in CCDA is a viable treatment option for reconstructing flexible flatfoot deformity. Although good clinical and radiographic outcomes were obtained, our method is even more challenging than conventional methods and should be used with caution. Rigid locking fixation with a long period of protected weightbearing is highly recommended to attain uneventful bone healing.     

Diagnostic Value of Early Magnetic Resonance Imaging After Acute Lateral Ankle Injury

We report a retrospective study of 171 consecutive patients with a lateral ankle sprain. All the patients with direct or blunt force trauma were excluded. Within 21 days of injury, 115 (67.25%) patients had undergone magnetic resonance imaging to evaluate for more serious or significant injuries. The average patient age was 44.09 years. Of the 115 patients, 75 (65.23%) had findings noted to be “significant.” MRI can serve as a valuable and underused tool in the evaluation of acute lateral ankle injuries. The underuse of MRI might explain the high degree of variability in patients recovering from a lateral ankle sprain.     

The use of an IL1‐receptor antagonist to reverse the changes associated with established tendinopathy in a rat model

Interleukin‐1 (IL1) is a cytokine that plays a role in inflammation and is a potential contributor to the inflammation present in tendinopathy. Its inhibition may be of use in the treatment of tendinopathy and has been a target for treatment. To evaluate how an IL1‐receptor antagonist (IL1‐RA) reverses pathologic changes associated with established patellar tendinopathy, we randomized 48 Sprague‐Dawley retired breeder rats into three groups having weekly bilateral patellar tendon injections for 6 weeks. The control group received 0.1 mL saline for 6 weeks. The intervention groups were treated with 0.1 mL 2% carrageenan for 4 weeks. Beginning at week three, the IL1‐RA group received 0.94 mg of the IL1‐RA (2.5 mg/kg) added to the 0.1 mL 2% carrageenan and 0.94 mg of the IL1‐RA alone for the final 2 weeks, while the CAR received 0.1 mL saline for the final 2 weeks. Animals were euthanized 6 weeks after initial injection. The CAR group demonstrated significantly (P < 0.05) shorter tendon lengths (7.81 ± 0.44 mm) than the control (8.25 ± 0.58 mm) and IL1‐RA (8.34 ± 0.52 mm) group (P < 0.05). Macroscopically, plaque‐like formations were reduced and margins of the tendon were more evident in the IL1‐RA group compared to the CAR group. CAR group demonstrated significantly greater histopathologic changes (inflammatory cell density, disorganization of collagen, nuclear rounding, and angiogenesis) than the control and IL1‐RA group. No significant difference in mechanical properties of the tendon was noted. These findings demonstrate IL1‐RA can reduce pathologic changes in the patellar tendon in an established tendonitis model although did not demonstrate a difference in mechanical properties.     

Plantarflexor metabolics are sensitive to resting ankle angle and optimal fiber length in computational simulations of gait

Background: Plantarflexor structure is an important predictor of function in healthy, athletic, and some patient populations. Computational simulations are powerful tools capable of testing the isolated effects of muscle-tendon structure on gait function.Research Question: The purpose of this study was to characterize the sensitivity of plantarflexor muscle function based on muscle-tendon unit (MTU) parameters. We hypothesized that plantarflexor metabolics and shortening dynamics would be sensitive to MTU parameters.Methods: Stance phase of gait was simulated using a musculoskeletal model and computed muscle control algorithm. Optimal muscle fiber length, resting ankle angle, and tendon stiffness parameters were systematically changed to test these effects on plantarflexor metabolics, activation, and power. Dorsiflexor metabolics were also measured to determine the impact of the action of the antagonist muscle group.Results and Significance: Plantarflexor metabolic demands were 1.5 and 2.7 times more sensitive to optimal fiber length and resting ankle angle, respectively, compared to the effect of tendon stiffness. Increased resting ankle plantarflexion induced a large passive plantarflexion moment during early stance, which required non-physiologic dorsiflexor contractions. Conversely, longer optimal fiber and more neutral resting ankle angles increased the shortening demands of the plantarflexors. These findings highlight the importance of carefully selecting MTU parameters when modeling gait with musculoskeletal models, especially in pathologic or high-performance athlete populations.     

Synovial-type giant cell tumors of the vertebral column: a clinicopathologic study of 15 cases,with a review of the literature and discussion of the differential diagnosis

Synovial and tenosynovial giant cell tumors only rarely arise in close proximity to the axial skeleton; to date, fewer than 30 examples have been reported in the English-language medical literature. In this report we describe the clinical, radiologic, histopathologic, and immunohistochemical findings in 15 cases retrieved from our files. The study group comprised 7 males and 8 females, ranging in age from 17 to 44 years (mean age, 32 years). The tumors involved the cervical (n = 11), thoracic (n = 1), lumbar (n = 2), and sacrococcygeal (n = 1) regions and ranged in size from 1.0 to 6.0 cm in greatest dimension (median size, 3 cm). Symptoms were present for 2 months to at least 2 years, with the most common complaint being pain localized to the spinal region (n = 12). Ten patients also had radicular symptoms. Radiologic studies, available for 11 cases, usually demonstrated a mass involving the posterior aspect of adjoining vertebrae. Bony abnormalities (including scalloping, erosion, and destruction), facet joint and soft tissue involvement, and extradural extension were typically present. Histologically, all tumors contained a proliferation of epithelioid (histiocytoid) cells, admixed with varying numbers of osteoclast-like giant cells, siderophages, xanthoma cells, lymphocytes, and some spindled fibroblast-like cells. Only 1 tumor had the classic villiform architecture of pigmented villonodular synovitis. The remaining 14 tumors had a nodular appearance with varying amounts of collagen. Seven of these had definite histological evidence of infiltrative growth, and 6 had some features that warranted concern for possible infiltration. Only 1 tumor had findings fully compatible with a localized synovial-type giant cell tumor/nodular (teno)synovitis. All tumors had mitotic activity, with mitotic counts ranging from 1 to 21 mitotic figures per 50 high-power fields (HPFs) (mean mitotic count, 5 mitotic figures/50 HPFs). Immunohistochemistry was performed on 5 tumors, and immunoreactivity was present for CD68, CD163, and vimentin. Limited immunoreactivity for muscle actin (HUC1-1) was also noted. Follow-up information was available for 9 of the 15 patients (60%). Five patients had no evidence of recurrent or persistent disease 4 months to 9 years after undergoing either a local excision with gross total tumor removal (with or without irradiation) or a wide en bloc resection. Four patients had persistent disease after undergoing either an incomplete resection or biopsy with spinal fusion procedure. All 4 of these patients had additional surgical intervention (accompanied by irradiation in 2 instances), but only one was known to be disease-free at last follow-up (10 years after gross total tumor removal). No patient has experienced a metastasis or died of disease. The best predictor of outcome was gross total tumor removal at the surgical outset.     

组织工程化肌腱种子细胞的研究

组织工程化肌腱有望成为临床肌腱缺损修复最为理想的替代物。随着种子细胞功能研究的逐步深入、新型种子细胞的不断发掘以及相关科学技术的进步,制约组织工程化肌腱发展的瓶颈之一“种子细胞”问题逐渐得到解决,组织工程化肌腱的体外构建及体内应用亦随之日趋成熟。着重就肌腱种子细胞的研究进展作一综述。     

胎儿膈肌中心腱的解剖观察

在解剖显微镜下,对34例胎儿及2例成人尸体的膈肌标本,进行了观察。膈肌中心腱三叶均为3层构筑,且中心腱的纤维束大都呈人字形分劈,形成2个方向不同的腱膜纤维层。中心腱的前叶纤维,大部分越过正中线,与对边和侧叶的深、浅层腱纤维相延续,整个膈肌在前后、左右之间形成了二腹肌样的排列结构。这种构筑提示中心腱不是膈肌周围肌性部分的止点,而是膈肌中间腱膜互相交叉延续的共同区域。本文观察表明,膈肌中心腱纤维束的分劈及其规则排列,在胎儿时期即已形成。这对增加膈的弹性和韧性,有利于膈的呼吸运动,具有重要的功能意义。     

Regional differences in cell shape and gap junction expression in rat Achilles tendon: relation to fibrocartilage differentiation

Tendon cells have complex shapes, with many cell processes and an intimate association with collagen fibre bundles in their extracellular matrix. Where cells and their processes contact one another, they form gap junctions. In the present study, we have examined the distribution of gap junction components in phenotypically different regions of rat Achilles tendon. This tendon contains a prominent enthesial fibrocartilage at its calcaneal attachment and a sesamoid fibrocartilage where it is pressed against the calcaneus just proximal to the attachment. Studies using DiI staining demonstrated typical stellate cell shape in transverse sections of pure tendon, with cells withdrawing their cell processes and rounding up in the fibrocartilaginous zones. Coincident with change in shape, cells stopped expressing the gap junction proteins connexins 32 and 43, with connexin 43 disappearing earlier in the transition than connexin 32. Thus, there are major differences in the ability of cells to communicate with one another in the phenotypically distinct regions of tendon. Individual fibrocartilage cells must sense alterations in the extracellular matrix by cell/matrix interactions, but can only coordinate their behaviour via indirect cytokine and growth factor signalling. The tendon cells have additional possibilities — in addition to the above, they have the potential to communicate direct cytoplasmic signals via gap junctions. The formation of fibrocartilage in tendons occurs because of the presence of compressive as well as tensile forces. It may be that different systems are used to sense and respond to such forces in fibrous and cartilaginous tissues.