Hallux valgus and hallux rigidus: MRI findings

A Retrospective Study Characterizing the Radiographic Progression of Hallux Valgus

Background: Hallux valgus deformity is the lateral deviation of the metatarsophalangeal (MTP) joint and is the most common pathology of the great toe, affecting 2%-4% of the population. It is commonly believed that the condition progresses over time both in the magnitude of deformity and development of arthritic changes. To our knowledge, there are rare studies describing the rate of deformity progression and the development of arthritic changes. Our aim is to quantify the progression of hallux valgus and associated arthritic changes in an adult population using radiographs.

Methods: Patients who are 18 years of age and older (mean age: 61.7 years and range: 18.6-94.2) who presented to our institutions between January 1, 2004, and December 1, 2019, were included. Patients were included in the study if they had hallux valgus on weight-bearing radiographs and two such radiographs at least six months apart. Hallux valgus angle (HVA), intermetatarsal angle (IMA), metatarsophalangeal (MTP) arthritis, tarsometatarsal (TMT) osteoarthritis, Hardy-Clapham sesamoid position, and round sign were collected per patient in the initial and final radiographs. Included cases were first studied together in a whole group. Then, cases were separated into three groups based on the time between initial and final radiographs.

Results: A total of 52 radiographic records for 43 patients were included. HVA and IMA progress with time; however, progression does not follow a direct relationship with the time elapsed between initial and final radiographs (p = 0.92 and p = 0.35, respectively). The progression of TMT osteoarthritis, sesamoid position, and round sign do not show a dependence on the time elapsed (p = 0.20, p = 0.11, and p = 0.42, respectively). An increase of one sesamoid unit position over baseline is associated with a 0.85-degree increase in IMA. A one-unit progression of sesamoid position at baseline raises the odds of MTP osteoarthritis progression at the follow-up visit by 2.14 (OR = 2.14, p = 0.0007, CI = [1.35, 3.83]). A HVA increase of one degree increases the odds of TMT osteoarthritis progression at follow-up by a factor of 1.17 (OR = 1.17, p = 0.0005, CI = [1.07, 1.34]). Patients with MTP arthritis at the initial visit have 3.77 times higher odds of round sign progression on their follow-up visit (OR = 3.77, p = 0.027, CI = [1.16, 13.13]).

Discussion: Hallux valgus progression can be quantified. Upon their first visit, a patient’s hallux valgus parameters can be utilized to demonstrate expected progression. Progression of the deformity and arthritic changes is slow. Nonetheless, the results should be considered by surgeons and patients when developing a treatment plan with patients.

Characterisation of first metatarsophalangeal joint osteoarthritis using magnetic resonance imaging

INTRODUCTION/OBJECTIVES

First metatarsophalangeal joint (MTP) joint osteoarthritis (OA) is prevalent, although the pathology of this condition is poorly understood. This study aimed to determine if there were differences in magnetic resonance imaging (MRI) characteristics of the first MTP joint between individuals with and without first MTP joint OA.

METHOD

This cross-sectional study compared 22 participants with first MTP joint OA to 22 control participants without first MTP joint OA (matched for age, sex, and body mass index). Participants underwent MRI of their first MTP joint and osteophytes, bone marrow lesions, subchondral cysts, effusion-synovitis, joint space narrowing, and cartilage loss were documented using an atlas of first MTP joint OA. Associations of MRI characteristics with the presence of first MTP joint OA were then determined.

RESULTS

The presence of first MTP joint OA was associated with increased severity of osteophytes (dorsal metatarsal head, plantar metatarsal head, and dorsal proximal phalanx), bone marrow lesions (metatarsal head and proximal phalanx), cysts of the metatarsal head, effusion-synovitis (dorsal aspect), joint space narrowing (metatarsal-proximal phalanx; metatarsal-sesamoids), and cartilage loss. In contrast, there were no statistically significant associations for bone marrow lesions of the sesamoids, cysts of the proximal phalanx, or effusion-synovitis (plantar aspect).

CONCLUSIONS

Osteophytes, bone marrow lesions, subchondral cysts, effusion-synovitis, joint space narrowing, and cartilage loss are characteristic MRI features of first MTP joint OA. First MTP joint OA is a disease of multiple joint tissues and this has implications for the assessment and management of this condition. Key Points • First metatarsophalangeal joint osteoarthritis is a disease of multiple joint tissues. • Osteophytes, bone marrow lesions, subchondral cysts, effusion-synovitis, joint space narrowing, and cartilage loss are characteristic MRI features of first metatarsophalangeal joint osteoarthritis. • These findings have implications for the assessment and management of this condition.

Sports Imaging of Team Handball Injuries

Team handball is a fast high-scoring indoor contact sport with > 20 million registered players who are organized in > 150 federations worldwide. The combination of complex and unique biomechanics of handball throwing, permitted body tackles and blocks, and illegal fouls contribute to team handball ranging among the four athletic sports that carry the highest risks of injury. The categories include a broad range of acute and overuse injuries that most commonly occur in the shoulder, knee, and ankle. In concert with sports medicine, physicians, surgeons, physical therapists, and radiologists consult in the care of handball players through the appropriate use and expert interpretations of radiography, ultrasonography, CT, and MRI studies to facilitate diagnosis, characterization, and healing of a broad spectrum of acute, complex, concomitant, chronic, and overuse injuries. This article is based on published data and the author team's cumulative experience in playing and caring for handball players in Denmark, Sweden, Norway, Germany, Switzerland, and Spain. The article reviews and illustrates the spectrum of common handball injuries and highlights the contributions of sports imaging for diagnosis and management.

High-Resolution MRI of the First Metatarsophalangeal Joint: Gross Anatomy and Injury Characterization

The first metatarsophalangeal joint (MTPJ) is vital to the biomechanics of the foot and supports a weight up to eight times heavier than the body during athletic activities. The first MTPJ comprises osseous and cartilaginous surfaces along with a complex of supporting structures, including the dorsal extensor tendons, collateral ligaments, and a plantar plate complex. In contradistinction to the lesser MTPJ plantar plates, a single dominant fibrocartilaginous capsular thickening does not exist at the first MTPJ. Instead, the plantar plate complex comprises a fibrocartilaginous pad that invests the hallux sesamoids and is inseparable from the plantar capsule, the intersesamoid ligament, paired metatarsosesamoid and sesamoid phalangeal ligaments (SPLs), and the musculotendinous structures. Acute injury at the first MTPJ is typically secondary to forced hyperextension-turf toe-and can involve multiple structures. During hyperextension, the resulting forces primarily load the distal SPLs, making these structures more susceptible to injury. SPL injuries are best seen in the sagittal plane at MRI. Radiography can also aid in diagnosis of full-thickness SPL tears, demonstrating reduced sesamoid excursion at lateral dorsiflexed (stress) views. Hallux valgus is another common condition, resulting in progressive disabling deformity at the first MTPJ. Without appropriate treatment, first MTPJ injuries may progress to degenerative hallux rigidus. The authors detail the anatomy of the first MTPJ in cadaveric forefeet by using high-resolution 3-T and 11.7-T MRI and anatomic-pathologic correlation. Injuries to the plantar plate complex, collateral ligaments, and extensor mechanism are discussed using clinical case examples. Online supplemental material is available for this article. ^©RSNA, 2020.

Clinical and imaging assessment and treatment of hallux valgus

Hallux valgus is a common condition estimated to affect as many as 23% of adults. The condition is associated with a variety of debilitating symptoms leading to significant morbidity and quality of life issues. Proper evaluation of this deformity and the timely management of its symptoms can improve hallux valgus-related symptomatology and quality of life. The most commonly used and readily reproduced measurements for assessing hallux valgus are the inter-metatarsal angle and the hallux valgus angle. These angles are helpful for choosing and planning surgical intervention for patients who fail initial conservative measures with distal osteotomies reserved for mild or moderate hallux valgus and proximal osteotomies indicated for more moderate to severe deformities. After reading this review article, readers will gain knowledge of the etiopathogenesis of hallux valgus, measurement parameters, and treatment strategies with representative case examples.

Factors influencing medial sesamoid arthritis in patients with hallux valgus deformity: Magnetic resonance imaging evaluation

BACKGROUND

The importance of preoperative evaluation of the position and degree of arthritic changes of the medial sesamoid bone before hallux valgus correction is emerging. This is an observational study to evaluate the magnetic resonance imaging (MRI) findings of hallux valgus deformity, and assess the severity of and identify the factors that influence the arthritic changes in medial sesamoid-metatarsal (mSM) joints.

METHODS

We reviewed weight-bearing anteroposterior radiographs, forefoot axial radiographs and MR images of 514 feet of 405 patients who underwent hallux valgus correction. On MRI, the degrees of the arthritic changes in the first metatarsophalangeal (MTP) and mSM joints were categorized into 5 classes. Binary logistic regression analysis was performed to identify the factors affecting the arthritic changes.

RESULTS

The binary logistic regression analysis showed that advanced age, more lateralized position of medial sesamoid bone on forefoot axial radiograph, and higher MRI grade of arthritic change of the 1st MTP joint were significant factors contributing to medial sesamoid arthritis (P<0.001, 0.001. 0.006, respectively).

CONCLUSIONS

Medial sesamoid arthritis can be assessed using MRI. The position of medial sesamoid bone on forefoot axial radiographs can strongly help predict the possibility of mSM joint arthritis.

LEVEL OF EVIDENCE

III, observational study.

Hallux valgus assessment on X-ray and Magnetic resonance Imaging (MRI): Correlation with qualitative soft tissue and internal derangement findings on MRI

AIM

Radiographs (X-rays) are used for the preoperative assessment of hallux valgus (HV). Our purpose was to determine how well quantitative measurements of HV on radiographs and MRI correlate with the qualitative soft tissue and internal derangement findings on MRI.

MATERIALS AND METHODS

After IRB approval, 56 consecutive patients with MRI and radiographs of the foot were retrospectively reviewed. Two trained readers independently evaluated radiographs, measuring hallux valgus angle (HVA) and intermetatarsal angle (IMA). Two separate readers assessed qualitative MRI data by evaluating 21 different soft tissue and bony features. Statistical analysis included inter-reader reliability (IRR) and correlation of quantitative and qualitative findings.

RESULTS

Excellent IRR (ICC = 0.89-0.96) was observed for radiograph and MRI measurements of the hallux valgus severity. For qualitative assessments on MRI, IRR was good to excellent for all features (ICC = 0.63-0.9). No significant difference was found for HVA or IMA between normal and abnormal qualitative MRI features. No statistically significant correlation between the severity of hallux valgus and injury to hallux joints and supporting structures was found.

CONCLUSION

Hallux valgus measurements are reliable on x-rays and MRI and qualitative findings of 1st MTP joint show good to excellent inter-reader agreement on MRI. No statistically significant correlations exist between the severity of hallux valgus and qualitative MRI findings.

Quantitative relationship of first metatarsophalangeal head morphology to hallux rigidus and hallux valgus

BACKGROUND

Previous qualitative studies have linked first metatarsal head morphology with hallux valgus (HV) and hallux rigidus (HR). This study used a quantitative measurement of 1st MT radius of curvature to assess if HR MT heads were flatter than HV heads.

METHODS

Weight bearing foot films were used in HV, HR, and normal patients (no forefoot complaints) to measure the metatarsal head radius of curvature (normalized by dividing the radius of curvature by the first metatarsal length to adjust for magnification and foot size).

RESULTS

Radiographs from 299 feet were analyzed (105 normal, 57 HR, and 137 HV). The mean normalized radius of curvature was smaller in HV than HR, with normal feet in between (p<.05 for all comparisons). Metatarsal head curvature did not vary with age, weight, or BMI.

CONCLUSION

These quantitative measurements are consistent with qualitative observations, validating the use of subjective metatarsal head morphology assessments.

Development of intraoperative plantar pressure measuring system considering weight bearing axis

PURPOSE

Surgical reconstructions in three dimensions are needed for treatment of foot and ankle deformities. However, surgical results might be influenced by the skill and experience of doctors which complement the limited information for reconstructions in three dimensions. To solve these, studies were carried out to measure plantar pressure distribution during surgery. Though, it was impossible to accurately measure plantar pressure distribution accurately during operation. Therefore, we proposed an intraoperative plantar pressure measurement (IPPM) device that enables proper navigation in the push direction.

METHODS

For this purpose, first, we investigated how the physiological load axis passes through the human body to identify the pushing direction of the pressure sensor of the device toward the patient's foot. In particular, we hypothesized that the physiological load axis passes through the femoral head center and we evaluated this in a measurement experiment with nine healthy subjects. Second, based on these results, we developed the IPPM device that has two force sensors to identify the pushing direction toward the femoral head center and a conductive ink sensor to measure plantar pressure distribution. Finally, we conducted the experiments with nine healthy subjects and two users.

RESULTS

From the first experimental results, the physiological load axis was found to pass through the femoral head center in normal standing posture. From the evaluation experiment, there are no significant differences statistically in plantar pressure distributions between the conditions of using IPPM device and without using it for both a medical student and a surgeon. However, in some cases the plantar pressure distribution can be reproduced similarly to that of the standing posture, and also from the evaluation experiment concerning the relation between CoP position and NCC, the NCC tends to increase when the position of the CoP is closer to that at the standing posture.

CONCLUSION

The IPPM device has possibility to reproduce the plantar pressure distribution during surgery and prevent the recurrence of surgical complications.

Imaging of Hallux Valgus: How to Approach the Deformity

This article describes the pathogenesis of hallux valgus (HV) and the traditional ways to image the deformities. It also discusses up-to-date advances and research in the field of imaging in HV. This includes weight-bearing computed tomography (CT) scanning, MRI, ultrasound and intraoperative imaging.

Repeatability and agreement of ultrasonography with computed tomography for evaluating forefoot structure in the coronal plane

Background

Forefoot structure is important to understand some foot problems such as hallux valgus and metatarsalgia. Ultrasonography (US) is a highly portable, noninvasive, low cost, and fast imaging method, especially when compared to magnetic resonance imaging (MRI), computed tomography (CT), and radiography. As the use of US for evaluating forefoot bony structure has not been validated, except for the presence of synovitis, erosions and bursitis within the forefoot in people with inflammatory arthritis, the purpose of this study was to determine whether US is a reliable method for evaluating forefoot structure.

Methods

Sixty feet (30 women, age = 40.1 ± 11.8 years) were examined by US and CT to assess agreement with CT and repeatability of US evaluation of the 2nd metatarsal head height, length between the medial sesamoid bone and 5th metatarsal head, transverse arch height, transverse arch index, sesamoid rotation angle, and area under the transverse arch. The measurement data were evaluated for agreement with CT using the intra-class correlation coefficient (ICC)_{3, 1}, Pearson correlation coefficient, and Bland-Altman plot, and with ICC_{1, 1} for repeatability.

Results

The ICC_{3, 1} values of 0.78–0.89, Pearson correlation coefficient of 0.78–0.90, and Bland-Altman plots showed almost perfect agreements between the US and CT method for all parameters, except the area under the transverse arch (AUTA). The ICC_{1, 1} also showed perfect agreements (0.84–0.92) between two sets of US measurements in all parameters.

Conclusions

The US evaluation of forefoot structure in the coronal plane showed good agreement with CT and repeatability of two ultrasonograms in adult women. This reliable evaluation method of forefoot structure can contribute to a quick clinical assessment screening for risk factors of foot problems such as hallux valgus and metatarsalgia. However, because of some limitations such as a lack of inter-observer reliability, more research is needed to validate US evaluation of forefoot structure.

Trial registration

The current study (trial registration number: R0297) was approved by the Ethical Committee for Human Experiments of Kyoto University (http://www.ec.med.kyoto-u.ac.jp) on December 3, 2015. The first participant in this study was enrolled on November 17, 2015 and retrospectively registered.

An assessment of hallux limitus in university basketball players compared with noncompetitive individuals

BACKGROUND

Injuries of the first metatarsophalangeal joint have lately been receiving attention from researchers owing to the important functions of this joint. However, most of the studies of turf toe injuries have focused on sports played on artificial turf.

METHODS

This study compared the range of motion of the first metatarsophalangeal joint in collegiate basketball players (n = 123) and noncompetitive individuals (n = 123).

RESULTS

A statistically significant difference (P < .001) in range of motion was found between the two groups. The difference between the two sample means was 21.35°.

CONCLUSIONS

With hallux rigidus being a potential sequela of repeated turf toe injuries, it seems likely that subacute turf toe injuries occur in basketball players, leading to degenerative changes that result in hallux limitus.

Hallux Rigidus: Relevant Anatomy and Pathophysiology

Hallux rigidus is a painful condition of the great toe characterized by restriction of the metatarsophalangeal joint arc of motion and progressive osteophyte formation. Precise cause of hallux rigidus remains under debate. Anatomic variations and historical, clinical, and radiographic findings have been implicated in the development and progression of hallux rigidus. Radiologic findings associated with hallux rigidus include metatarsal head osteochondral defects, altered metatarsal head morphology, and an elevated hallux interphalangeus angle measure. Associated historical findings include a positive family history and history of trauma to the joint. An understanding of relevant anatomy and pathophysiology is essential during the approach to hallux rigidus treatment.

First Metatarsophalangeal Joint Degeneration: Arthroscopic Treatment

Arthroscopic treatment of hallux rigidus is appropriate after failed nonoperative treatment. Debridement with cheilectomy, and fusion are the main indications for arthroscopic treatment of hallux rigidus. If the cartilage damage is extensive and the patient has consented, then a fusion is performed at the same sitting.

Demographic and clinical factors associated with radiographic severity of first metatarsophalangeal joint osteoarthritis: cross-sectional findings from the Clinical Assessment Study of the Foot

OBJECTIVE

To explore demographic and clinical factors associated with radiographic severity of first metatarsophalangeal joint osteoarthritis (OA) (First MTPJ OA).

DESIGN

Adults aged ≥50 years registered with four general practices were mailed a Health Survey. Responders reporting foot pain within the last 12 months were invited to undergo a clinical assessment and weight-bearing dorso-plantar and lateral radiographs of both feet. Radiographic first MTPJ OA in the most severely affected foot was graded into four categories using a validated atlas. Differences in selected demographic and clinical factors were explored across the four radiographic severity subgroups using analysis of variance (ANOVA) and ordinal regression.

RESULTS

Clinical and radiographic data were available from 517 participants, categorised as having no (n = 105), mild (n = 228), moderate (n = 122) or severe (n = 62) first MTPJ OA. Increased radiographic severity was associated with older age and lower educational attainment. After adjusting for age, increased radiographic first MTPJ OA severity was significantly associated with an increased prevalence of dorsal hallux and first MTPJ pain, hallux valgus, first interphalangeal joint (IPJ) hyperextension, keratotic lesions on the dorsal aspect of the hallux and first MTPJ, decreased first MTPJ dorsiflexion, ankle/subtalar joint eversion and ankle joint dorsiflexion range of motion, and a trend towards a more pronated foot posture.

CONCLUSIONS

This cross-sectional study has identified several dose-response associations between radiographic severity of first MTPJ OA and a range of demographic and clinical factors. These findings highlight the progressive nature of first MTPJ OA and provide insights into the spectrum of presentation of the condition in clinical practice.

First metatarsophalangeal joint- MRI findings in asymptomatic volunteers

OBJECTIVES

To evaluate the spectrum and frequency of MR findings of the first metatarsophalangeal joint (MTPJ) in asymptomatic volunteers.

METHODS

MR imaging of 30 asymptomatic forefeet was performed with a dedicated extremity 1.5-Tesla system. Participants were between 20 and 49 years of age (mean ± SD: 35.5 ± 8.4 years). Two radiologists assessed cartilage, bone, capsuloligamentous structures, and tendons of first MTPJs on MR images.

RESULTS

Cartilage defects were observed in 27 % (n = 8) of first MTPJs, most frequently located at the base of the proximal phalanx (23 %, n = 7), whereas cartilage defects of the metatarsal head (13 %, n = 4) and the metatarsosesamoid compartment were rare (0 %-3 %, n = 0-1). Bone marrow oedema-like signal changes were present in 37 % (n = 11) and subchondral cysts in 20 % (n = 6) of first MTPJs. Hyperintense areas on intermediate-weighted sequences (range: 30-43 %, n = 9-13) and on fluid-sensitive sequences with fat suppression (range: 33-60 %, n = 10-18) within the medial and lateral collateral ligament complex were common. Plantar recesses (77 %, n = 23) and distal dorsal recesses (87 %, n = 26) were frequently observed.

CONCLUSIONS

Cartilage defects, bone marrow oedema-like signal changes, subchondral cysts, plantar recesses, and distal dorsal recesses were common findings on MRI of first MTPJs in asymptomatic volunteers. The collateral ligaments were often heterogeneous in structure and showed increased signal intensity.

KEY POINTS

• Cartilage defects of asymptomatic first metatarsophalangeal joints were common on MRI. • The collateral ligaments were often heterogeneous in structure and showed increased signal intensity. • Areas of increased signal intensity within the flexor and extensor tendons were rare. • These observations need to be considered in MR examinations of symptomatic cases.

Early signs of osteoarthritis in professional ballet dancers: a preliminary study

OBJECTIVE

To investigate a cohort of professional ballet dancers for evidence of early signs of osteoarthritis (OA).

DESIGN

One radiologist and 1 orthopedic surgeon specialized in musculoskeletal disorders analyzed magnetic resonance imaging scans independently.

SETTING

University Teaching Hospital.

PARTICIPANTS

Fifteen professional ballet dancers (4 males and 11 females; age range, 19-36 years) experiencing chronic pain in the hip, knee, spine, ankle, or foot joints.

MAIN OUTCOME MEASURES

Presence of osteophytes, subchondral sclerosis, joint space narrowing, cysts, and bone marrow changes; the Kellgren and Lawrence scale was used to quantify the knee OA.

RESULTS

In the knee, there was thinning and irregularity of the articular cartilage over the medial femoral condyle and bone marrow changes within the lateral femoral condyle. In the hip, there was a loss of joint space and a frayed labrum with deep recess. The first metatarsophalangeal joint showed evidence of osteophytic development.

CONCLUSIONS

Early signs of OA, in different joints, were present in a small but highly selected cohort of professional ballet dancers. In future, prospective studies among a number of ballet companies should control for medical and natural history alongside the visual analysis of images and plain radiographs to confirm these preliminary results.

Hallux valgus and plantar pressure loading: the Framingham foot study

BACKGROUND

Hallux valgus (HV), a common structural foot deformity, can cause foot pain and lead to limited mobility. The purpose of this study was to evaluate differences in plantar pressure and force during gait by HV status in a large population-based cohort of men and women.

METHODS

A trained examiner performed a validated physical examination on participants' feet and recorded the presence of hallux valgus and other specific foot disorders. Each foot was classified into one of four mutually exclusive groups based on the foot examination. Foot groups were: (i) HV only, (ii) HV and at least one additional foot disorder (FD), (iii) no HV but at least one other FD, and (iv) neither HV nor FD (referent). Biomechanical data for both feet were collected using Tekscan Matscan. Foot posture during quiet standing, using modified arch index (MAI), and foot function during gait, using center of pressure excursion index (CPEI), were calculated per foot. Further, walking scans were masked into eight sub-regions using Novel Automask, and peak pressure and maximum force exerted in each region were calculated.

RESULTS

There were 3205 participants, contributing 6393 feet with complete foot exam data and valid biomechanical measurements. Participants with HV had lower hallucal loading and higher forces at lesser toes as well as higher MAI and lower CPEI values compared to the referent. Participants with HV and other FDs were also noted to have aberrant rearfoot forces and pressures.

CONCLUSIONS

These results suggest that HV alters foot loading patterns and pressure profiles. Future work should investigate how these changes affect the risk of other foot and lower extremity ailments.

Biplanar proximal phalanx closing wedge osteotomy for hallux rigidus

BACKGROUND

Many procedures have been described for surgical treatment of symptomatic hallux rigidus. Dorsal cheilectomy of the metatarsophalangeal joint combined with a dorsal-based closing wedge osteotomy of the proximal phalanx (i.e., Moberg procedure) has been described as an effective procedure. For patients with hallux rigidus and clinically significant hallux valgus interphalangeus, the authors previously described a dorsal cheilectomy combined with a biplanar closing wedge osteotomy of the proximal phalanx, combining a Moberg osteotomy with an Akin osteotomy. The purpose of this study was to describe the clinical results of this procedure.

METHODS

This article is a retrospective review of prospectively gathered data that reports the clinical and radiographic results of dorsal cheilectomy combined with a biplanar oblique closing wedge proximal phalanx osteotomy (i.e., Moberg-Akin procedure) for patients with symptomatic hallux rigidus and hallux valgus interphalangeus. Consecutive patients were followed and evaluated for clinical and radiographic healing, satisfaction, and ultimate need for additional procedure(s). Thirty-five feet in 34 patients underwent the procedure.

RESULTS

All osteotomies healed. At an average of 22.5 months of follow-up, 90% of patients reported good or excellent results, with pain relief, improved function, and fewer shoe wear limitations following this procedure. Hallux valgus and hallux interphalangeal angles were radiographically improved. Other than one patient who requested hardware removal, no patients required additional surgical procedures.

CONCLUSIONS

Dorsal cheilectomy combined with a Moberg-Akin procedure was an effective and durable procedure with minimal morbidity in patients with hallux rigidus combined with hallux valgus interphalangeus.

The pathogenesis of hallux valgus

The first ray is an inherently unstable axial array that relies on a fine balance between its static (capsule, ligaments, and plantar fascia) and dynamic stabilizers (peroneus longus and small muscles of the foot) to maintain its alignment. In some feet, there is a genetic predisposition for a nonlinear osseous alignment or a laxity of the static stabilizers that disrupts this muscle balance. Poor footwear plays an important role in accelerating the process, but occupation and excessive walking and weight-bearing are unlikely to be notable factors. Many inherent or acquired biomechanical abnormalities are identified in feet with hallux valgus. However, these associations are incomplete and nonlinear. In any patient, a number of factors have come together to cause the hallux valgus. Once this complex pathogenesis is unraveled, a more scientific approach to hallux valgus management will be possible, thereby enabling treatment (conservative or surgical) to be tailored to the individual.

Evaluation and biomechanics of the first ray in the patient with limited motion

Adequate first ray function is essential to healthy human gait. Controversies still exist about aspects of human structure and function and many newer answers and theories have been proposed by a new generation of experts. Examples include the sagittal plane facilitation, tissue stress, and preferred movement pathway theories. This article also presents a summary of how to provide a thorough, detailed, and accurate first ray examination on the individual with limited motion. This article explores functional first ray mechanics in both a theoretic and biomechanical perspective, as well as a practical, hands-on examination perspective.

Multislice CT angiography of the plantar arch

The aim of this case report is to present a multislice computed tomography angiography (CTA) procedure for viewing the plantar arch. A CTA was requested to determine the vascular sufficiency of the plantar arch of a 64-year-old patient with necrotic and gangrenous toes. The patient had recently undergone a proximal wedge osteotomy procedure for correction of a hallux valgus deformity. A 16-detector row CT scanner with 1.25 mm slice thickness and 0.625 mm reconstruction interval was used to reconstruct multiplanar reformats, maximum intensity projections and three-dimensional volume rendered images of the foot in question in both arterial and venous phases to determine if pathology of the plantar arch was present. The 3D reconstructed images of CTA demonstrated a loss of continuity of the plantar arch between the first and third metatarsals. This case report shows the diagnostic value of multislice CTA, especially 3D visualisation in the assessment of peripheral vascular branches.

Forefoot plantar shear stress distribution in hallux valgus patients

BACKGROUND

Hallux valgus is a common foot disorder often experienced with secondary callosities and metatarsalgia. Many factors including improper shoes might be responsible in the pathophysiology of the problem. Hallux valgus deformity has been shown to alter the biomechanics of the whole foot rather than affecting only the great toe. Due to changes in the biomechanical functioning of the first ray, other regions of the forefoot area have been shown to bear abnormal loads with increased vertical loading on medial, central and lateral forefoot regions. The purpose of this study was to investigate the pattern of forefoot plantar shear loading in hallux valgus patients and compare these results with those of control subjects.

METHODS

A total of 28 subjects were recruited for the study of which 14 were clinically diagnosed with hallux valgus. A custom built platform was used to collect peak pressure and shear data. A repeated measures analysis of variance was used to analyze the recorded data.

FINDINGS

Antero-posterior shear was significantly lower in the deformity group (p<0.05). The lateral forefeet of the patients, however, experienced slightly higher shear loads (p>0.05).

INTERPRETATION

Propulsive shear force generation mechanism under the medial forefoot was impaired in the disorder group. In general, shear loading of the plantar feet shifted laterally. Previously hypothesized higher medio-lateral shear magnitudes under the hallux were not confirmed.

Hallux rigidus: etiology, biomechanics, and nonoperative treatment

Hallux rigidus is a degenerative osteoarthritic process characterized by progressive loss of metatarsophalangeal joint range of motion and notable dorsal or periarticular osteophyte formation. Documented factors associated with hallux rigidus are a flat or chevron-shaped joint, hallux valgus interphalangeus, metatarsus adductus, bilaterality in persons with a positive family history, trauma history in unilateral cases, and female gender. Elevation of the first ray noted radiographically is thought to be a sign of worsening metatarsophalangeal joint function. Nonoperative care is aimed at improving comfort of the toe and foot with roomy shoes, selective joint injections, taping, and selective use of orthotics.

Cross-sectional study to evaluate radiological parameters in hallux rigidus

BACKGROUND

Hallux rigidus (HR) is a common condition with X-rays used to evaluate its pathology, grade joint changes and to inform treatment.

METHOD

A cross-sectional study was undertaken to evaluate radiological foot parameters in HR. In 110 subjects (180 feet) aged 18-70 years (mean 52 years) standard weight-bearing X-rays were examined using dorsal plantar and lateral views.

RESULTS

Seventy (64%) subjects had bilateral HR and 73 (66%) were female. The mean onset of HR (denoted by first metatarsophalangeal (MTP) joint restriction/pain) was 44 (14-68 years) years and median HR duration was 6 years (1-33 years). Flat or chevron-shaped metatarsal heads presented in 131 (73%) feet and a history of first MTP joint trauma in 22% (74% of whom had unilateral HR). In 74% of feet hallux abductus interphalangeus angle (HAI degrees) was greater than normal (< or =10 degrees). Correlations between first MTP joint narrowing and sclerosis (r=0.76, p=0.01) and increased HAI degrees and first MTP joint narrowing (r=0.34, p=0.01) was found. The mean hallux equinus angle of 11 degrees was outside the normal range (16-18 degrees). Abnormal sesamoid morphology presented in 117 (65%) feet (30% irregular or hypertrophic). Proximal sesamoid displacement was greater than that seen in non-HR. Metatarsus primus elevatus was within normal range (< or =8 mm) in 160 (89%) feet. The first metatarsal was longer than the second metatarsal in 66 (37%) feet although the first metatarsal was longer than the third metatarsal in 131 (73%) feet and may be responsible for altered forefoot function in HR.

CONCLUSIONS

HR was associated with female gender, bilateral involvement, older age groups, flat or chevron-shaped metatarsal head, longer proximal phalanx, increased HAI degrees and a first metatarsal longer than the third metatarsal. For radiological parameters to be considered valid for inclusion in a classification of HR their content validity needs to be established by formal research.

Imaging of soft tissue lesions of the foot and ankle

Differential diagnosis of soft tissue lesions of the foot can be narrowed with imaging. The cystic nature of ganglia, synovial cysts, and bursitis can be confirmed with MR imaging or sonography. Location and signal characteristics of noncystic lesions can suggest Morton's neuroma, giant cell tumor of tendon sheath, and plantar fibromatosis. Synovial-based lesions of the foot and ankle can be differentiated based on presence or absence of mineralization, lesion density, signal intensity, and enhancement pattern. Knowledge of the incidence of specific neoplasms of the foot and ankle based on patient age aids in providing a limited differential diagnosis.

Classification systems for hallux rigidus: a review of the literature

BACKGROUND

Hallux rigidus (HR) is one of the most common causes of forefoot pain. A number of classification systems have been developed to evaluate HR. These systems are based on either radiological parameters alone or a combination of radiological and clinical features. The purpose of this paper is to critically evaluate HR classification systems by undertaking a detailed review using English language medical and paramedical databases.

MATERIALS AND METHODS

The authors identified 18 formal HR classification systems described in the literature, some of which are variations on a theme.

RESULTS

No clear consensus on the construction of HR classification systems appears to exist. Different criteria and methods are used which make comparison difficult. Furthermore, it appears that, no serious consideration has been given to their reliability and validity. Criteria used to justify inclusion of these parameters have been based mainly on clinical experience rather than formal research.

CONCLUSION

For such a common condition, there is a need for a properly constructed, prospective study to develop a suitable classification system. It should include scientifically validated parameters to help stratify different stages of the disease and aid clinical and scientific communication.

Hallux valgus: demographics, etiology, and radiographic assessment

BACKGROUND

The purpose of the study was to preoperatively evaluate the demographics, etiology, and radiographic findings associated with moderate and severe hallux valgus deformities in adult patients (over 20 years of age) treated operatively over a 33-month period in a single surgeon's practice.

METHODS

Patients treated for a hallux valgus deformity between September, 1999, and May, 2002, were identified. Patients who had mild deformities (hallux valgus angle < 20 degrees), concurrent degenerative arthritis of the first metatarsophalangeal joint, inflammatory arthritis, recurrent deformities, or congruent deformities were excluded. When enrolled, all patients filled out a standardized questionnaire and had a routine examination that included standard radiographs, range of motion testing, and first ray mobility measurement. A chart review and evaluation of preoperative radiographs were completed on all eligible patients.

RESULTS

One-hundred and three of 108 (96%) patients (122 feet) with a diagnosis of moderate or severe hallux valgus (hallux valgus angle of 20 degrees or more)(70) qualified for the study. The onset of the hallux valgus deformity peaked during the third decade although the distribution of occurrence was almost equal from the second through fifth decades. Twenty-eight of 122 feet (23%) developed a deformity at an age of 20 years or younger. Eighty-six (83%) of patients had a positive family history for hallux valgus deformities and 87 (84%) patients had bilateral bunions. 15% of patients in the present series had moderate or severe pes planus based on a positive Harris mat study. Only 11% (14 feet) had evidence of an Achilles or gastrocnemius tendon contracture. Radiographic analysis found that 86 of 122 feet (71%) had an oval or curved metatarsophalangeal joint. Thirty-nine feet (32%) had moderate or severe metatarsus adductus. A long first metatarsal was common in patients with hallux valgus (110 of 122 feet; 71%); the mean increased length of the first metatarsal when compared to the second was 2.4 mm. While uncommon, the incidence of an os intermetatarsum was 7% and a proximal first metatarsal facet was 7%. The mean preoperative first ray mobility as measured with Klaue's device was 7.2 mm. 16 of 22 (13%) feet were observed to have increased first ray mobility before surgery.

CONCLUSIONS

The magnitude of the hallux valgus deformity was not associated with Achilles or gastrocnemius tendon tightness, increased first ray mobility, bilaterality or pes planus. Neither the magnitude of the preoperative angular deformity nor increasing age had any association with the magnitude of the first metatarsophalangeal joint range of motion. Constricting shoes and occupation were implicated by 35 (34%) patients as a cause of the bunions. A familial history of bunions, bilateral involvement, female gender, a long first metatarsal, and an oval or curved metatarsophalangeal joint articular surface were common findings. Increased first ray mobility and plantar gapping of the first metatarsocuneiform joint were more common in patients with hallux valgus than in the general population (when compared with historical controls).

The value of radiographic parameters in the surgical treatment of hallux rigidus

The purpose of this study was to determine if metatarsal protrusion or the length of the first and second rays were associated with the incidence of hallux rigidus. For this retrospective study, anteroposterior radiographs from 51 patients diagnosed with hallux rigidus and 51 patients without evidence of hallux rigidus were selected for review as a control group. Radiographs were randomly assigned to one of two raters who determined the metatarsal protrusion distance, first metatarsal length, second metatarsal length, length of the proximal phalanx of the hallux, length of the proximal phalanx of the second toe, and overall hallux length. A statistical comparison of these radiographic measurements showed only first metatarsal length to significantly differ (P = .05) between the two groups (65.4 +/- 5.3 mm and 67.7 +/- 5.9 mm for the hallux rigidus and control groups, respectively). The findings of this study suggest the need to revisit the role that metatarsal protrusion distance and first metatarsal length play in the etiology of hallux rigidus. In addition the need to surgically correct a long first metatarsal should be further evaluated.

Paleopathological study of hallux valgus

Hallux valgus is the abnormal lateral deviation of the great toe. The principal cause is biomechanical, specifically the habitual use of footwear which constricts the toes. In this study, descriptions of the anatomical changes of hallux valgus from published cadaveric and clinical studies were used to generate criteria for identifying the condition in ancient skeletal remains. The value of systematic scoring of hallux valgus in paleopathology is illustrated using two British skeletal series, one dating from the earlier and one from the later Medieval period. It was found that hallux valgus was restricted to later Medieval burials. This appears consistent with archaeological and historical evidence for a rise in popularity, during the late Medieval period (at least among the richer social classes), of narrow, pointed shoes which would have constricted the toes.

MRI Characteristics of Olecranon Bursitis

OBJECTIVE

Our aim was to describe the MRI characteristics of septic and nonseptic olecranon bursitis.

MATERIALS AND METHODS

MRI contrast-enhanced examinations (n = 19) of 35 patients with olecranon bursitis (septic, n = 14; nonseptic, n = 21) were jointly reviewed by two musculoskeletal radiologists. We evaluated bursa size, extent of marginal lobulation, septation, concomitant elbow joint effusion, soft-tissue edema, rim enhancement, soft-tissue enhancement, degree of fluid complexity, definition of bursa margins, presence of edema, thickening of the triceps tendon, and bone marrow edema.

RESULTS

Comparison of septic and nonseptic bursitis yielded the following results: marginal lobulation, 79% (11/14) versus 48% (10/21), p = 0.14; bursa septation, 64% (9/14) versus 57% (12/21), p = 1.0; moderate or marked complexity of bursa fluid, 64% (9/14) versus 29% (6/21), p = 0.15; poorly defined margins, 64% (9/14) versus 67% (14/21), p = 1.0; elbow joint effusion, 86% (12/14) versus 52% (11/21), p = 0.12; moderate to marked soft-tissue edema, 64% (9/14) versus 33% (7/21), p = 0.1; edema of the triceps, 57% (8/14) versus 48% (10/21), p = 0.73; thickening of the triceps, 43% (6/14) versus 14% (3/21), p = 0.21; bone marrow edema, 29% (4/14) versus 5% (1/21), p = 0.13; rim enhancement, 100% (11/11) versus 75% (6/8), p = 0.31; soft-tissue enhancement, 100% (11/11) versus 63% (5/8), p = 0.1.

CONCLUSION

Septic and nonseptic olecranon bursitis present with a considerable overlap of MRI findings without statistically significant differences. Septic olecranon bursitis can be excluded in the absence of bursal and soft-tissue enhancement.

Hallux rigidus: demographics, etiology, and radiographic assessment

PURPOSE

The purpose of the study was to evaluate the demographics, etiology, and radiographic findings associated with hallux rigidus in patients treated surgically over a 19-year period in a single surgeon's practice.

METHODS

Patients treated for hallux rigidus by cheilectomy and metatarsophalangeal joint fusion were identified from 1981 to 1999. Patients who had diabetes, inflammatory arthritis, infectious arthritis, crystalline arthritis, multiple forefoot deformities, neuromuscular disorders, or had died were excluded. A chart review and evaluation of preoperative radiographs were completed on all eligible patients. All identified patients were invited for a follow-up examination that included standard and stress radiographs, range-of-motion testing, Harris mat study, gait analysis, first ray mobility measurement, and standardized questionnaire assessment.

RESULTS

One hundred ten of 114 (96.5%) patients with a diagnosis of hallux rigidus returned for the final evaluation. Eighty cheilectomy patients (93 feet) and 30 arthrodesis patients (34 feet) were evaluated. The mean age at onset in the current study was 43 years (13-70 years) and only six patients developed symptoms at an age of less than 20 years. Hallux rigidus was graded based on a five-grade clinical-radiographic system. The mean follow-up was 8.9 years. Ninety-five percent of patients with a positive family history had bilateral disease at the final follow-up. At the initial examination in the current study, 81% of patients had radiographic and clinical evidence of unilateral disease, but at the final follow-up 79% of patients had radiographic and clinical evidence of bilateral disease. Eleven percent of patients in the present series had pes planus based on either a positive Harris mat study and/or heel valgus. There was no evidence of an Achilles or gastrocnemius tendon contracture. Radiographic analysis found that the concurrent presentation of hallux valgus and hallux rigidus was not common. Ninety-three of 127 feet (73%) had a chevron or flat metatarsophalangeal joint. Thirty-five feet were noted to have mild or moderate metatarsus adductus. A long first metatarsal was no more common in patients with hallux rigidus than in the general population. The mean first ray elevatus was 5.5 mm and was well within acceptable limits of normal. The mean first ray mobility was 5 mm in arthrodesis patients and 5.8 mm in cheilectomy patients.

CONCLUSION

Hallux rigidus was not associated with elevatus, first ray hypermobility, a long first metatarsal, Achilles or gastrocnemius tendon tightness, abnormal foot posture, symptomatic hallux valgus, adolescent onset, shoewear, or occupation. Hallux rigidus was associated with hallux valgus interphalangeus, bilateral involvement in those with a familial history, unilateral involvement in those with a history of trauma, and female gender. Metatarsus adductus was more common in patients with hallux rigidus than in the general population but a clear correlation was not found. Additionally, a flat or chevron-shaped metatarsophalangeal joint was more common in hallux rigidus patients.

Regional musculoskeletal conditions: foot and ankle disorders

Foot pain is very common, especially in women, owing to inappropriate footwear. Overuse, repetitive strain and minor, easily forgettable injuries may result in chronic foot and ankle pain. Rheumatoid arthritis, spondyloarthropathies and gout frequently affect the foot, often as a first presentation. Charcot's joints and foot infections are not rare in diabetes. The rheumatologist should be familiar with foot disorders, either localized or as manifestations of generalized disease. History taking, physical examination, identification of the source of pain by intra-articularly given local anaesthetics and imaging methods should be used to reveal the underlying disorder. Correct diagnosis and efficient therapy-including local steroid injections, physiotherapy, orthoses, surgery-are necessary not only for treatment but also for preventing biomechanical chain reactions. This chapter gives an overview of the epidemiology, diagnosis and treatment of foot pain and foot disorders caused by both local and generalized diseases.

Forefoot pain involving the metatarsal region: differential diagnosis with MR imaging

Many disorders produce discomfort in the metatarsal region of the forefoot. These disorders include traumatic lesions of the soft tissues and bones (eg, turf toe, plantar plate disruption, sesamoiditis, stress fracture, stress response), Freiberg infraction, infection, arthritis, tendon disorders (eg, tendinosis, tenosynovitis, tendon rupture), nonneoplastic soft-tissue masses (eg, ganglia, bursitis, granuloma, Morton neuroma), and, less frequently, soft-tissue and bone neoplasms. Prior to the advent of magnetic resonance (MR) imaging, many of these disorders were not diagnosed noninvasively, and radiologic involvement in the evaluation of affected patients was limited. However, MR imaging has proved useful in detecting the numerous soft-tissue and early bone and joint processes that occur in this portion of the foot but are not depicted or as well characterized with other imaging modalities. Frequently, MR imaging allows a specific diagnosis based on the location, signal intensity characteristics, and morphologic features of the abnormality. Consequently, MR imaging is increasingly being used to evaluate patients with forefoot complaints. Radiologists should be familiar with the differential diagnosis and MR imaging features of disorders that can produce discomfort in this region.