Magnetic resonance imaging of skewfoot

Ankle and Foot Deformities in Children

Ankle and foot deformity is one of the most common musculoskeletal disorders in children and a leading cause of functional impairment and diminished quality of life when not treated. A spectrum of conditions may produce foot and ankle deformities, with congenital disorders the most frequent cause, followed by acquired conditions. Congenital disorders include congenital talipes equinovarus or congenital clubfoot, metatarsus adductus, skewfoot, congenital vertical talus, and tarsal coalition.Some of these deformities are frequent and easily diagnosed based on clinical features, but clinical overlap between pathologies can be challenging. Thus imaging plays a paramount role in evaluating these patients. Radiographs are the first imaging modality of choice, but they may not be sufficient in infants due to the lack of ossification of the tarsal bones. Ultrasonography allows not only a detailed visualization of the cartilaginous structures but also permits a dynamic study of the foot and ankle. Computed tomography may be necessary in certain conditions such as tarsal coalitions.

Assessment of hindfoot alignment using MRI and standing hindfoot alignment radiographs (Saltzman view)

OBJECTIVE

To compare the hindfoot alignment measured on standing HAV radiographs (Saltzman view) and on non-weight-bearing coronal MR images.

MATERIALS AND METHODS

The apparent moment arm was measured on weight-bearing conventional radiographs (Saltzman views) and on MRIs of the ankle in 50 consecutive patients (mean age, 54 years; age range, 18-77 years). The evaluation was performed independently by three readers using analogous reference points for both methods. Positive values were assigned when the deepest point of the calcaneus was lateral to the tibial axis as valgus, negative values as varus. The intertechnique agreement and correlation for the measurements performed with HAV radiographs and MRI were assessed for each reader using the Bland-Altman method and the Pearson correlation coefficient, respectively. The interobserver agreement was assessed using the intraclass correlation coefficient.

RESULTS

The means of apparent moment arms, with the standard deviation (SD) in parentheses, of three readers were +2.0 (±8.4) mm, +1.5 (±6.6) mm and -1.4 (±8.2) mm on HAV radiographs and +4.6 (±7.4) mm, +6.3 (±5.3) mm and +5.4 (±6.4) mm on MRI. The Bland-Altman analysis found a systematic bias for all three readers, corresponding to an overestimation of measurements with MRI (systematic bias ranging from 2.6 to 4.8 mm). The intertechnique correlation was found moderate to high. The Pearson coefficients for the three readers were 0.75, 0.64 and 0.65. The interobserver agreement among the three readers was 0.72, 0.77 and 0.68 for HAV, MRI and both modalities together, respectively.

CONCLUSION

Hindfoot alignment can be estimated on MRI but the correlation between the values on HAV radiographs and MR images is only moderate with a tendency to increased positive values (valgization) on MR images.

Ultrasound evaluation of foot deformities in infants

Foot deformity in infants is the most common congenital musculoskeletal condition. A precise diagnosis can sometimes be impossible to establish clinically. Radiologic imaging plays a major role in the evaluation of musculoskeletal abnormalities. However conventional imaging techniques, such as plain radiographs of the foot, are of very little help in this age group because of the lack of ossification of the tarsal bones. US presents a significant advantage because it permits the visualization of cartilaginous structures. This leads to the detailed assessment of foot deformities in infants. Furthermore, US can also be used as a dynamic imaging modality. Different scanning views are beneficial to evaluate the complete anatomy of the foot; depending on the suspected clinical diagnosis, some planes are more informative to display the pathological features of a specific deformity. We describe the US findings of five of the most common foot deformities referred to our pediatric orthopedic clinic (clubfoot, simple metatarsus adductus, skewfoot, and oblique and vertical talus). For each deformity we propose a specific imaging protocol based on US to provide an accurate diagnosis. US is a complementary tool to the clinical examination for determining the diagnosis and the severity of the deformity and also for monitoring the efficacy of treatment. Radiologists investigating foot deformities in infants should consider using US for the detailed assessment of the foot in this age group.

Trends in the surgical treatment of articular cartilage defects of the knee in the United States

PURPOSE

The purpose of this study was to evaluate trends in surgical treatment of articular cartilage defects of the knee in the United States.

METHODS

The current procedural terminology (CPT) billing codes of patients undergoing articular cartilage procedures of the knee were searched using the PearlDiver Patient Record Database, a national database of insurance billing records. The CPT codes for chondroplasty, microfracture, osteochondral autograft, osteochondral allograft, and autologous chondrocyte implantation (ACI) were searched.

RESULTS

A total of 163,448 articular cartilage procedures of the knee were identified over a 6-year period. Microfracture and chondroplasty accounted for over 98% of cases. There was no significant change in the incidence of cartilage procedures noted from 2004 (1.27 cases per 10,000 patients) to 2009 (1.53 cases per 10,000 patients) (p = 0.06). All procedures were performed more commonly in males (p < 0.001). This gender difference was smallest in patients undergoing chondroplasty (51 % males and 49% females) and greatest for open osteochondral allograft (61% males and 39% females). Chondroplasty and microfracture were most commonly performed in patients aged 40-59, while all other procedures were performed most frequently in patients <40 years old (p < 0.001).

CONCLUSIONS

Articular cartilage lesions of the knee are most commonly treated with microfracture or chondroplasty in the United States. Chondroplasty and microfracture were most often performed in middle-aged patients, whereas osteochondral autograft, allograft, and ACI were performed in younger patients, and more frequently in males.

LEVEL OF EVIDENCE

Cross-sectional study, Level IV.

The effects of arthroscopic joint debridement in the knee osteoarthritis: results of a meta-analysis

PURPOSE

Knee osteoarthritis is one of the most common orthopaedic diseases. Therapeutic options for this disease include conservative treatments and arthroscopic debridement and partial or complete replacement. This meta-analysis aimed to collect and analyse the available information on the effects of arthroscopic joint debridement related to the clinical outcomes, the required conversion to replacement and the factors for patient selection.

METHODS

A search for publications was performed in the PubMed, Cochrane and EMBASE medical databases. The primary search resulted in a total of 1,512 citations. The results from 30 papers were included in this study. The extracted dates were listed in a standardised protocol. The statistical evaluation was performed using Comprehensive Meta-analysis software (V2 Biostat, Englewood, NJ, USA).

RESULTS

No randomised study that compared conservative and arthroscopic treatments for knee osteoarthritis was found. Most studies reported middle-term results after arthroscopic operations. The results of these studies showed excellent or good outcomes in more than 60 % of all patients. These results were correlated with a significant increase in the knee scores from baseline to follow-up; the standardised difference in means was 2.3 (CI 95 % 1.5-3.0, p < 0.001). The required conversion rate to replacement increased as the follow-up interval increased. The rates were as follows: 1 year-6.1 % (CI 95 %, 2.1-16.6 %), 2 years-16.8 % (CI 95 %, 10.2-26.3 %), 3 years-21.7 % (CI 95 %, 15.5-29.1 %) and 4 years-34.1 % (CI 95 %, 22.8-47.6 %). The mean survival time was 42.7 (CI 95 %, 14.5-71.1) months. Numerous factors influenced the outcome, including the radiological stage of the osteoarthritis and individual patient factors (e.g. time of history of osteoarthritis, weight and smoking). The local knee findings, such as axial dysalignment, missing effusion and massive crepitus, were also correlated with patient outcome.

CONCLUSION

Arthroscopic joint debridement is a potential and sufficient treatment for knee osteoarthritis in a middle-term time interval. This procedure results in an excellent or good outcome in approximately 60 % of patients in approximately 5 years.

LEVEL OF EVIDENCE

Systematic review of studies, Level III.

Surgical implants and technologies for cartilage repair and preservation of the knee

Focal lesions of the articular cartilage of the knee can be managed with a variety of products and technologies in an attempt to restore function to the afflicted joint and forestall the need for possible total knee arthroplasty. Among these approaches are non-implant-based procedures (arthroscopic chondroplasty and microfracture), grafting procedures (autografts/mosaicplasty and allografts), cell-based procedures (autologous chondrocyte implantation) and nonbiologic implants (metallic plugs and cell-free polymers). For each clinically established procedure there are also a number of investigational variations that aim to improve the in vivo quality of the regenerated/restored cartilage surface. This article analyzes existing and developing non-implant- and graft-based technologies for the repair or restoration of the articular cartilage of the knee based on a review of the published literature.

Autologous chondrocyte implantation versus ACI using 3D-bioresorbable graft for the treatment of large full-thickness cartilage lesions of the knee

BACKGROUND

In autologous chondrocyte implantation (ACI), the periosteum patch which is sutured over the cartilage defect has been identified as a major source of complications such as periosteal hypertrophy. In the present retrospective study, we compared midterm results of first-generation ACI with a periosteal patch to second generation ACI using a biodegradable collagen fleece (BioSeed-C) in 82 patients suffering from chronic posttraumatic and degenerative cartilage lesions of the knee.

METHODS

Clinical outcome was assessed in 42 patients of group 1 and in 40 patients of group 2 before implantation of the autologous chondrocytes and at a minimum follow-up of 2 years using the ICRS score, the modified Cincinnati score and the Lysholm score.

RESULTS

Although patients treated with BioSeed-C had more previous surgical procedures on their respective knees, highly significant improvements (P < 0.001) were assessed in both groups at comparable outcome levels: the ICRS score improved from grade D (poor) preoperatively to grade C (fair); the modified Cincinnati knee score from 3.26 to 6.4 (group 1) and 3.3 and 6.88 (group 2). Lysholm score improved from 33 to 70 points (group 1) and from 47 to 78 points (group 2), respectively. Revision surgery was due to symptomatic periosteal hypertrophy (n = 4), graft failure (n = 3), plica syndrome (n = 2) synovectomy (n = 1) (group 1); and graft failure (n = 2), debridement (n = 1), synovectomy (n = 2) (group 2).

CONCLUSION

These results suggest that BioSeed-C is an equally effective treatment option for focal degenerative chondral lesions of the knee in this challenging and complex patient profile.

Disease-specific clinical problems associated with the subchondral bone

The subchondral bone is involved in a variety of diseases affecting both the articular cartilage and bone. Osteochondral defects in distinct locations and of variable sizes are the final results of different etiologies. These include traumatic osteochondral defects, osteochondritis dissecans, osteonecrosis, and osteoarthritis. Traumatic osteochondral defects are caused by osteochondral fractures, separating an osteochondral fragment that includes articular cartilage and both subchondral and trabecular bone from the joint surface. In osteochondritis dissecans, the disease originates in the subchondral bone and secondarily affects the articular cartilage. Location, stage, size, and depth of osteochondral lesions play a role in the treatment of traumatic osteochondral defects and osteochondritis dissecans. Surgical options include fragment refixation, transplantation of osteochondral autografts, or bone restoration by impacted cancellous bone grafts combined with autologous chondrocyte transplantation. An insufficiency fracture of the subchondral bone may be the initiating factor of what was formerly believed to be a spontaneous osteonecrosis of the knee (SPONK). Recent histopathological studies suggest that each stage of SPONK reflects different types of bone repair reactions following a fracture of the subchondral bone plate. Osteoarthritis is a disease that does affect not only the articular cartilage, but also the subchondral bone. Reconstructive surgical techniques aim at preserving joint function, inducing fibrocartilaginous repair, and at correcting malalignment. This review summarizes the current status of the clinical treatment of traumatic osteochondral defects, osteochondritis dissecans, osteonecrosis, and osteoarthritis as they affect the subchondral bone region and its adjacent structures.

Pediatric metatarsus adductus and skewfoot deformity

Skewfoot is a rare condition that is often missed early in a child's development. Mild and flexible forms can be successfully treated with cast immobilization and shoe therapy. In more severe forms, surgical intervention is indicated if there are underlying neuromuscular conditions or the individual is affected on a daily basis because of the deformity. Careful evaluation and proper surgical procedures selection can realign the foot, resulting in favorable long-term outcomes. This article presents clinical and radiographic evaluation techniques and treatment options.

Skewfoot

Skewfoot is a rare deformity characterized by forefoot adduction and hindfoot valgus. Its etiology and natural history are unknown, although congenital and syndromic forms are observed. Currently, there is no consent about the treatment of skewfoot. Due to its potential resistance to the effects of therapy, it must be differentiated from other, more common deformities. Treatment involves conservative and, most often, operative measures.

The treatment of articular cartilage defects using the microfracture technique

Chondral defects of the articular surface pose a challenging problem to the orthopedic surgeon. The goal of surgery is to alleviate pain, maximize function, and prevent degenerative changes in the future. A number of techniques have been described to treat these lesions. When considering the treatment options for chondral defects, the surgeon must consider the size, depth, location, and chronicity of the lesion. In addition, the overall alignment of the joint must be evaluated. Prior to treating chondral defects, it is important to understand the indications and contraindications for the microfracture technique. When indicated, the microfracture technique has many advantages over other surgical options. This technique is relatively easy to perform, cost effective, and has low patient morbidity. In addition, the microfracture technique does not burn any long-term bridges, enabling the surgeon to choose a different procedure to revise the chondral defect if the microfracture fails. It is important to understand the mechanism of healing by microfracture, including the effects of the local environment. The postoperative protocol used after the procedure may be as important as the surgery itself. Understanding the science behind the microfracture procedure will lead to better surgical technique and improved outcomes.

Müller-Weiss disease: clinical and biomechanical features

Müller-Weiss disease is a rare condition that is characterized by an odd deformation of the tarsal navicular, which may appears queezed and eventually fragmented between the talar head and the lateral cuneiforms. Because the head of the talus protrudes laterally, the subtalar joint remains in an inverted position. The plantar arch may correspond to that of a normal, cavus, or flat foot. The disease is not the consequence of a osteonecrotic process but results from impaired development of the bone, in most instances because of stressing environmental factors during childhood. Isolated cases that are due to individual predisposing factors are rare, although most of the patients can be grouped together as late collateral damage of war or poverty.

Assessment of the position of the navicular by three-dimensional magnetic resonance imaging in infant foot deformities

As the navicular is unossified in infants with foot deformities, until 5 years old (boys) and 3 years old (girls), it is difficult to give the exact position of hindfoot bones. Magnetic resonance imaging associated with three-dimensional reconstruction allows the visualization of the cartilaginous volume of the bones and the measurement of the relationships of the navicular with the talus. In normal feet, we noted that in the coronal plane the navicular was laterally situated (75%) relative to the talus. In club feet (17 patients), the navicular and the cuboid had a large medial displacement (77%) with a slight pronation movement in the sagittal plane. In suspected skewfoot (seven feet) we noted three cases with a lateral subluxation of the navicular. This objective technique of measurement may be of value for diagnosis and treatment of foot deformities.