Fractures of proximal portion of fifth metatarsal bone: anatomic and imaging evidence of a pathogenesis of avulsion of the plantar aponeurosis and the short peroneal muscle tendon

New Classification System for Proximal Fifth Metatarsal Fractures: Intraobserver and Interobserver Reliability Assessment

BACKGROUND

The most commonly used classification for proximal fifth metatarsal fractures has not shown good reproducibility. The aim of this study was to evaluate the intraobserver and interobserver agreement of a new classification system for such fractures.

METHODS

The study involved the development of a novel classification system that categorized these fractures into 2 main types and 2 subtypes. This cross-sectional study included a total of 52 cases that were retrospectively collected to assess the reliability of this system. These cases were then evaluated by 3 independent foot and ankle surgeons who classified the fractures based on the newly established classification system. After 10 months, the same evaluators classified the fractures again. The level of agreement among the evaluators, both internally and externally, was assessed using the kappa coefficient, following the criteria established by Landis and Koch. This framework categorizes agreement levels as slight (0.00-0.20), fair (0.21-0.40), moderate (0.41-0.60), substantial (0.61-0.80), or almost perfect (0.81-1.00).

RESULTS

Fifty-two fractures were detected, and 312 evaluations were carried out. The interobserver agreement was substantial when assessing the 2 main types, with a κ value of 0.73, and remained substantial even when considering the subtypes, with a κ value of 0.67. Similarly, the intraobserver agreement demonstrated substantial outcomes when evaluating the 2 main types, with a κ value 0.79. It maintained its significance when including the subtypes, with a κ value 0.77.

CONCLUSION

Lawrence and Botte's classification identifies 3 primary zones and exhibits moderate interobserver agreement. In contrast, the newly proposed system focuses on only 2 main zones and shows better interobserver agreement. The present study introduces a more precise and reproducible framework that reveals consistency among various observers, including the same observer. This framework may be beneficial for biomedical research as it enhances the ability to compare results across different studies.

Clinical and variational evaluation of peroneus tertius muscle

This research was conducted to define the typology of the peroneus tertius, which is considered to be a part of the musculus extensor digitorum muscle and plays a role in dorsiflexion and eversion of the foot. In addition, another aim of the study was to examine the relationship of the peroneus tertius with the extensor digitorum longus and to investigate the possible effects of the tendon/insertio properties of the peroneus tertius on the fifth metatarsal. In this study; classical anatomical dissection was performed on 30 lower limbs. In this study, various parameters related to muscle origin, insertion, tendon and muscle dimensions were measured. It has been found that PTM was absent in 26.6% of the specimens and in 23.3% (n = 7) of the cases PTM was directly originated from the EDL. In 56.7% of the specimens (n = 17), the PTM tendon was mutually inserted into the dorsomedial surface of the 5th metatarsal and dorsolateral of the 4th metatarsal, while in 10.0% of the specimens it has thin medial bands (2 × 1 mm) towards the 5th digit. At the end of the study, the PTM origin was categorized into three different types and PTM insertion was categorized into five different types. Variation of PTM, muscle morphology and tendon diameter are extremely important in terms of minimally invasive surgical technique. Since the accessory tendon must have the properties close to the tendon that will be replaced, we believe that the results of our research provide unique useful information to clinicians. This study is the cadaver research.

Fractures of the limbs: basic concepts for the emergency department

Traumatic injuries of the limbs are very common and account for a large number of imaging examinations, especially in emergency departments. These injuries can often be resolved if they are recognized and treated appropriately. Their diagnosis requires a complete clinical assessment and the correct interpretation of the appropriate imaging tests. Radiologists play an important role, especially in diagnosing lesions that can go undetected. To this end, radiologists need to know the normal anatomy and its variants, the mechanisms of injury, and the indications for different imaging tests, among which plain-film X-rays are the main technique for the initial evaluation. This article aims to review the relevant characteristics of limb fractures in adults and of lesions that can be associated with these fractures, as well as how to describe them to ensure appropriate clinical management.

Short leg cast versus orthotic removable support for the management of pseudo-Jones avulsion fracture: A systematic review and meta-analysis

BACKGROUND

The fifth metatarsal base avulsion fracture (i.e., Pseudo-Jones fracture) is one of the most common foot fractures. The management of pseudo-Jones fractures could be carried out surgically or conservatively. This systematic review and meta-analysis aimed to provide an update about the efficacy of orthotic removable support compared to short-leg casting for individuals with pseudo-Jones fracture.

METHODS

We searched Embase, Medline, and Cochrane Central register of Controlled Trials (CENTRAL) for randomized controlled trials (RCTs) that compared the clinical outcomes of orthotic removable support and short-leg cast for adult individuals with a fifth metatarsal base avulsion fracture. We used 95% as a confidence level and P <0.05 as a threshold. The standardized mean difference (SMD) was used for the continuous outcomes, and the risk ratio (RR) was used for the dichotomous outcomes.

RESULTS

A total of 6 RCTs incorporating 403 individuals out were deemed eligible. There was no significant difference between orthotic removable support and short-leg casting regarding AOFAS score (standardized mean difference (SMD)= 0.31, 95% CI -0.17 to 0.8), pain on VAS score (SMD= -0.08, 95% CI -0.39 to 0.22), VAS-FA score (SMD= 0.22, 95% CI -0.19 to 0.62) EQ-5D VAS score, and non-union rate (RR=0.37, 95% CI 0.05 to 2.74).

CONCLUSION

The current meta-analysis reveals that there is no difference between orthotic removable support and short-leg casting for the conservative management of individuals sustaining pseudo-Jones fracture.

Fractures of the Base of the Fifth Metatarsal Bone: A Critical Analysis Review

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Fractures of the proximal fifth metatarsal (PFMT) are one of the most common foot injuries, accounting for 61% to 78% of all foot fractures, but full consensus on their classification, diagnosis, and treatment has not yet been reached.

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The most commonly accepted classification is that of Lawrence and Botte, who divided the location of PFMT fractures into 3 zones with respect to their healing potential.

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Avulsion fractures of the tuberosity of the base (zone 1) generally heal well, and nonoperative treatment is commonly recommended.

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Internal fixation may be considered for displaced fractures that extend into the fourth-fifth intermetatarsal joint (zone 2) as well as for nondisplaced fractures in athletes or high-demand patients, with the aims of reducing the healing time and expediting return to sport or work.

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Stress fractures of the proximal diaphysis (zone 3) are preferably treated operatively, particularly in the presence of signs of delayed union. With nonoperative treatment, supportive measures such as ultrasonography or external/extracorporeal shockwave therapy have been demonstrated to have limited potential for the enhancement of fracture-healing.

Avulsion injuries: an update on radiologic findings

Avulsion injuries result from the application of a tensile force to a musculoskeletal unit or ligament. Although injuries tend to occur more commonly in skeletally immature populations due to the weakness of their apophysis, adults may also be subject to avulsion fractures, particularly those with osteoporotic bones. The most common sites of avulsion injuries in adolescents and children are apophyses of the pelvis and knee. In adults, avulsion injuries commonly occur within the tendon due to underlying degeneration or tendinosis. However, any location can be involved in avulsion injuries. Radiography is the first imaging modality to diagnose avulsion injury, although advanced imaging modalities are occasionally required to identify subtle lesions or to fully delineate the extent of the injury. Ultrasonography has a high spatial resolution with a dynamic assessment potential and allows the comparison of a bone avulsion with the opposite side. Computed tomography is more sensitive for depicting a tiny osseous fragment located adjacent to the expected attachment site of a ligament, tendon, or capsule. Moreover, magnetic resonance imaging is the best imaging modality for the evaluation of soft tissue abnormalities, especially the affected muscles, tendons, and ligaments. Acute avulsion injuries usually manifest as avulsed bone fragments. In contrast, chronic injuries can easily mimic other disease processes, such as infections or neoplasms. Therefore, recognizing the vulnerable sites and characteristic imaging features of avulsion fractures would be helpful in ensuring accurate diagnosis and appropriate patient management. To this end, familiarity with musculoskeletal anatomy and mechanism of injury is necessary.

Ankle Joint Injuries Accompanying Fifth Metatarsal Base Fractures

BACKGROUND

Fifth metatarsal base fractures are the most commonly seen fractures of the foot. Ankle sprains occur with inversion and plantarflexion mechanisms, similar to most fifth metatarsal base fractures. We sought to investigate the possible ankle injuries that accompany fifth metatarsal base fractures.

METHODS

A hospital's digital database was searched for the International Classification of Diseases, Tenth Revision codes for metatarsal bone fractures (codes S92.30 and S92.35) between January 2015 and January 2018. Thirty-nine patients with fifth metatarsal base fracture who underwent ankle magnetic resonance imaging (MRI) within 14 days of injury were included in the study. The MRI findings were evaluated, and comparisons were performed according to fracture zone, sex, and age.

RESULTS

The most common MRI finding was talocrural joint effusion, which was observed in 28 patients (71.8%). Bone marrow edema was observed in 16 patients (41.0%). Chondral injury at the medial dome of talus was observed in three patients (7.7%). Grade 1 ligament sprain was observed in six patients (15.4%): two in the lateral ligament and four in the deltoid ligament.

CONCLUSIONS

Although most fifth metatarsal base fractures and ankle sprains occur as a result of a common mechanism, physical examination findings and patients' complaints are very important. Routine MRI should be unnecessary for most patients. If a patient with a fifth metatarsal base fracture has complaints about the ankle joint, one should be aware of bone marrow edema, which was observed in 41.0% of the study population.

Hard-Soled Shoe Versus Short Leg Cast for a Fifth Metatarsal Base Avulsion Fracture: A Multicenter, Noninferiority, Randomized Controlled Trial

BACKGROUND

The purpose of this study was to determine whether tolerated weight-bearing in a hard-soled shoe was noninferior to the use of a short leg cast for the treatment of a fifth metatarsal base avulsion fracture, as assessed with use of a 100-mm visual analog scale (VAS) for pain at 6 months after the fracture.

METHODS

A total of 145 patients were assessed for eligibility. Of these, 96 patients were randomly assigned to either the hard-soled shoe group (46 patients) or the cast group (50 patients). The primary outcome measure was the mean difference on the 100-mm VAS between groups at 6 months after the fracture. Secondary outcome measures included the time to return to preinjury activity and patient-reported satisfaction. Analysis was performed according to both an intention-to-treat basis (i.e., patients were included in the assessment of their assigned treatment arm, even if they crossed over to the other treatment arm prior to completing the 6-month follow-up) and a per-protocol basis (i.e., patients who completed the 6-month follow-up were analyzed according to the treatment they received).

RESULTS

At 6 months after the fracture, the mean 100-mm VAS was 8.6 ± 7.0 mm in the hard-soled shoe group and 9.8 ± 7.3 mm in the cast group (p = 0.41) according to intention-to-treat analysis. The mean difference in 100-mm VAS between the 2 groups was -1.3 mm (95% confidence interval, -4.3 to 1.8 mm). The upper limit of the 95% confidence interval did not exceed the noninferiority margin of 10 mm, indicating that treatment with the hard-soled shoe was noninferior to treatment with the short leg cast. The proportion of patients who reported satisfaction with their treatment was similar between the hard-soled shoe and cast groups (89.5% compared with 87.5%, respectively; p = 0.79), but the time to return to preinjury activity was significantly shorter in the hard-soled shoe group (37.2 ± 14.4 days compared with 43.0 ± 11.1 days in the cast group; p = 0.04). There were no cases of nonunion in either group.

CONCLUSIONS

Weight-bearing as tolerated in a hard-soled shoe for a fifth metatarsal base avulsion fracture was noninferior to the use of a short leg cast as assessed with use of a 100-mm VAS at 6 months after the fracture. Patient-reported satisfaction was similar between groups, but the time to return to preinjury activity was shorter in the hard-soled shoe group.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Adequate union rates for the treatment of acute proximal fifth metatarsal fractures

PURPOSE

To compare the bone healing, clinical, and return to daily activity outcomes after either surgical or conservative management of acute zone 1, 2, and 3 fifth metatarsal fractures.

METHODS

A literature search was performed to identify studies published from the earliest record to January 2019 using EMBASE (Ovid), MEDLINE via PubMed, CINAHL, and Web of Science. All articles assessing clinical outcomes of acute proximal fifth metatarsal fractures were included. Bone healing and clinical outcomes were thereafter calculated using a simplified pooling method.

RESULTS

Thirty-two articles comprising of a total of 1,239 fractures were included, of which one was a randomized controlled trial, seven were prospective studies, and 24 were retrospective studies. 627 zone 1 fractures demonstrated union rates of 93.2% following conservative treatment and 95.1% following surgical treatment. Conservatively managed zone 1 fractures were displaced 49.5% of the time, compared to a rate of 92.8% for the surgically treated cases. For Jones' (zone 2) fractures, bone healing outcomes of conservative versus surgical treatment showed union rates of 77.4% versus 96.3%, refracture rates of 2.4% versus 2.1%, and mean time to union of 11.0 weeks versus 9.4 weeks, respectively. Only ten proximal diaphyseal (zone 3) fractures were reported, with a mean return to work of 8.2 weeks.

CONCLUSION

Acute zone 1 fractures are preferably treated conservatively as similar union rates were found after both conservative and surgical management. In contradistinction, acute zone 2 fractures demonstrate higher union rates and faster time to union when treated surgically. The outcomes of acute zone 3 fractures are rarely reported in the literature, so treatment recommendations remain unclear. Further research of proximal fifth metatarsal fractures is warranted to provide more definitive conclusions, but current findings can aid surgeons during the shared clinical decision making process.

LEVEL OF EVIDENCE

IV.

Biomechanical Comparison of Hook Plate vs Headless Compression Screw Fixation of Large Fifth Metatarsal Base Avulsion Fractures

BACKGROUND

Debate exists on the optimum fixation construct for large avulsion fractures of the fifth metatarsal base. We compared the biomechanical strength of 2 headless compression screws vs a hook plate for fixation of these fractures.

METHODS

Large avulsion fractures were simulated on 10 matched pairs of fresh-frozen cadaveric specimens. Specimens were assigned to receive two 2.5-mm headless compression screws or an anatomic fifth metatarsal hook plate, then cyclically loaded through the plantar fascia and metatarsal base. Specimens underwent 100 cycles at 50%, 75%, and 100% physiological load for a total of 300 cycles.

RESULTS

The hook plate group demonstrated a significantly higher number of cycles to failure compared with the screw group (270.7 ± 66.0 [range 100-300] cycles vs 178.6 ± 95.7 [range 24-300] cycles, respectively; P = .039). Seven of 10 hook plate specimens remained intact at the maximum 300 cycles compared with 2 of 10 screw specimens. Nine of 10 plate specimens survived at least 1 cycle at 100% physiologic load compared with 5 of 10 screw specimens.

CONCLUSION

A hook plate construct was biomechanically superior to a headless compression screw construct for fixation of large avulsion fractures of the fifth metatarsal base.

CLINICAL RELEVANCE

Whether using hook plates or headless compression screws, surgeons should consider protecting patient weight-bearing after fixation of fifth metatarsal base large avulsion fracture until bony union has occurred.

Optimizing surgery of metaphyseal-diaphyseal fractures of the fifth metatarsal: a cadaveric study on implications of intramedullary screw position, screw parameters and surrounding anatomic structures

AIMS

Many advocate screw fixation of fractures to the metaphyseal-diaphyseal junction of the fifth metatarsal base, better known as Jones fractures (JF), to facilitate quicker ambulation and return to sport. Maximizing screw parameters based on fifth metatarsal (MT5) anatomy, alongside understanding the anatomic structures compromised by screw insertion, may optimize surgical outcomes. This study aims to (1) correlate the proximity of JF to the peroneus brevis (PB) and plantar fascia (PF) footprints and (2) quantify optimal screw parameters given MT5 anatomy.

MATERIALS AND METHODS

3D CT-scan reconstructions were made of 21 cadaveric MT5s, followed by meticulous mapping of the PB and PF onto the reconstructions. Based on bone length, shape, narrowest intramedullary canal (IMC) diameter, and surrounding anatomy, two traditional debated screw positions were modeled for each reconstruction: (1) an anatomically positioned screw (AP), predicated on maximizing screw length by following the IMC for as long as possible, and (2) a clinically achievable screw (CA), predicated on maximizing screw length without violating the fifth tarso-metatarsal joint or adjacent cuboid bone. Fixation parameters were calculated for all models.

RESULTS

The PB and PF extended into the JF site in 29% and 43%, respectively. AP's did not affect PB and PF footprint but required screw entry through the cuboid and fifth tarso-metatarsal joint in all specimens. CA screw entry sites, avoiding the cuboid and fifth tarso-metatarsal joint, partially compromised the PB and PF insertions in 33% and 62% with a median surface loss of 1.6%%(range 0.2-3.2%) and 0.81%%(range 0.05-1.6%), respectively. Mean AP screw length was 64±3.6mm and thread length 49±4.2mm. Mean CA screw length was 48±5.8mm and thread length 28±6.9mm.

CONCLUSION

This study underscores the challenges associated with surrounding MT5 anatomy as they relate to optimal JF treatment. Both the extent of JF as well as a clinically achievable positioned screw violate the PB and PF footprints - although the degree to which even partial disruption of these footprints has on outcome remains unclear. To minimize damage to surrounding structures, including the PB and PF footprint, while allowing a screw length approximately two thirds of the metatarsal length, the CA screw position is recommended. This position balances the desire to maximize pull out strength while avoiding cortical penetration or inadvertent fracture site distraction.

Anatomic Characteristics of Tissues Attached to the Fifth Metatarsal Bone

Background

Two types of stress, bending stress and traction stress, have been reported to be involved in the mechanism of Jones fracture. However, little is known about the risk factors for traction stress.

Purpose

To classify the attachment position of the peroneus brevis muscle (PB), peroneus tertius (PT), lateral band of the plantar aponeurosis (LB), and the long plantar ligament (LPL), focusing on the zone where a Jones fracture occurs (zone 2), and to compare the footprint area of each tissue type.

Study Design

Descriptive laboratory study.

Methods

This study examined 102 legs from 55 Japanese cadavers. Type classification was performed by focusing on the positional relationship between each tissue attachment and the zone where Jones fracture occurs (zone 2). The classifications were as follows: type I, attached proximal to the border between zones 1 and 2; type IIa, attached to the border between zones 1 and 2 with one attached part; and type IIb, attached across the border between zones 1 and 2 with two or more attached parts. The footprint areas of the PB, PT, LB, and LPL were compared between tissue types and within each attachment classification.

Results

The PB was recorded as type I in 41 feet (40.2%), type IIa in 56 feet (54.9%), and type IIb in 5 feet (4.9%); the PT was recorded as type IIa in 54 feet (60.0%) and type IIb in 36 feet (40.0%); and the LB was recorded as type I in 27 feet (26.5%) and type IIa in 75 feet (73.5%). The LPL did not attach to the fifth metatarsal bone. No significant difference was found in the footprint area between type I PB and type I LB.

Conclusion

The results indicate that type I, which attaches proximal to zone 2, occurs with PB and LB, and there was no significant difference in the footprint area between them. These findings suggest that type I is involved in traction stress. In the future, biomechanical research based on the results of this study will be necessary.

Clinical Relevance

The results of this study provide basic research for investigating the mechanism of Jones fracture and the cause of delayed healing.

Treatment of proximal fifth metatarsal fractures with an ulna hook plate

INTRODUCTION

Fractures of the base of the fifth metatarsal bone present one of the commonest fractures of the metatarsal bones. Conventionally intramedullary screws and tension band wiring have been used as internal fixation methods. Lately hook plates have also served as an alternative fixation method. We hereby report on our experience with the hook plate used in treating fractures of the proximal fifth metatarsal.

METHODS

21 patients treated with the hook plate for proximal fifth metatarsal fractures were assessed clinically and radiologically.

RESULTS

Average time to union in primarily treated fractures (n=18) was 7.7 weeks (range 4.5-16 weeks). Average time to return of activities of daily living (ADLs) was 10.3 weeks (range 4.5-37 weeks). The average AOFAS midfoot score was 30.4 preoperatively and 95.2 postoperatively (p<0.01).

CONCLUSION

The ulna hook plate presents a suitable and adequate method of osteosynthesis used to primarily treat proximal fifth metatarsal fractures requiring surgical intervention with satisfactory post-operative outcomes.

Fibularis Tertius: Anatomical Study and Review of the Literature

Although there is much morphological variation in the anterior compartment of the leg, there is little information about the morphological variability of the fibularis tertius muscle (FTM). The main aim of the present study was to characterize the morphology (origin and insertion) and frequency of occurrence of the FTM and to use these findings as the basis for a new classification of the fibularis tertius tendon. Classical anatomical dissection was performed on 106 lower limbs fixed in 10% formalin. The presence of the FTM and the morphology of both its origin and its insertion were described. The FTM was present in 91 limbs (85.8%). Three types of origin were observed: Type 1, the most common type, with its origin on the distal half fibula (67%); Type 2, with the origin on the distal third fibula (22%); and Type 3, with an origin from the tendon of the extensor digitorum longus (11%). In addition, six types of insertion were distinguished. The most common was Type I (45%), a single distal attachment where the tendon inserts into the shaft of the fifth metatarsal bone. The rarest was Type VI, characterized by fusion with an additional band of the fibularis brevis tendon, which gives rise to the fourth interosseus dorsalis muscle. Two morphological variants of insertion could be distinguished, fan-shaped and band-shaped. Both the origin and insertion of the FTM are very morphologically variable, with three types of origin (Types 1-3) and six types of insertion point (Types I-VI) observed. Knowledge of such variations is essential for both clinicians and anatomists. Clin. Anat. 32:1082-1093, 2019. © 2019 Wiley Periodicals, Inc.

Small but troublesome: accessory ossicles with clinical significance

Accessory ossicles are supernumerary and inconstant structures that are not caused by fractures. Derived from unfused ossification centers, accessory ossicles were first described by Vesalius in 1543. For centuries, they were believed to be asymptomatic. However, with advances in radiology techniques, many have been associated with painful syndromes. Although the original descriptions date from the sixteenth century, the subject is little discussed and, in some cases, controversial. The objective of this study was to describe the radiological aspects of a series of accessory ossicles and to review the evolution of their various descriptions, in order to revive discussion of the subject.

Peroneus brevis tendon in proximal 5th metatarsal fractures: Anatomical considerations for safe hook plate placement

INTRODUCTION

The peroneus brevis tendon (PBT) inserts into the proximal aspect of the 5th metatarsal. Metatarsal bone fractures are encountered to be the most common fractures in the foot with predominantly fractures at the base of the fifth metatarsal bone. Mechanism of injury and treatment of the proximal 5th metatarsal fractures vary due to the complex anatomy and diverse biomechanical properties. The purpose of this study was to analyze the footprint of the PBT with regards to the proximal 5th metatarsal fractures and to define a "safe zone" for hook plate placement.

MATERIALS AND METHODS

Forty-one (41) fixed human lower leg specimens were dissected to expose the PBT insertion. The following footprint characteristics were evaluated: area of insertion (AOI) (mm²), length (mm), width (mm), shape and insertional variations. The position of the main PBT footprint was localized according to the Lawrence and Botte classification for the proximal 5th metatarsal fractures (Zone I-III). A "safe zone" was defined for the fracture-specific hook plate placement.

RESULTS

In 25 (61%) feet the PBT footprint was situated in Zone I and in 16 feet (39%) in Zone I&II. The mean AOI, length and width measured 54.5 mm² (SD 16.5), 16.0 mm (SD 5.1) and 4.7 mm (SD 1.4), respectively. Analysis of the footprint shapes revealed four different shape types: kidney (29.3%), diamond (22.0%), crescent (31.7%) and oval (17.0%). A "safe zone" for hook plate placement without or minimal interference of the PBT at its insertion could be defined at the lateral aspect of the 5th metatarsal.

CONCLUSION

The majority of the PBT footprints were found in Zone I. Hook plate placement demonstrated to be safe when placed strictly laterally at the proximal aspect of the 5th metatarsal. Precise knowledge of the peroneus brevis anatomy may help to better understand the biomechanical aspects of the proximal 5th metatarsal fractures.

Early radiographic and clinical outcomes of minimally displaced proximal fifth metatarsal fractures: cast vs functional bandage

Background

The purpose of this non-randomized retrospective study was to investigate outcomes of minimally displaced, proximal 5MTB fractures, treated by a below-knee walking cast or a functional elasticated bandage with a support of a flat hard-soled shoe.

Methods

A consecutive patient series was divided into two groups: the cast group (CG) and the functional group (FG). The subjects were radiologically and clinically evaluated according to Mehlhorn and Lawrence-Botte classification, and AOFAS Midfoot score, respectively.

Results

154 patients were followed up for a median of 15 months (range 12-24). There was no significant difference (p > 0.05) among the outcomes of each fracture pattern regarding the treatment choice. However, an earlier return to sports was noted in the FG, while Type-3 fractures achieved the worst results.

Conclusion

Type-1 and 2 minimally displaced 5MTB proximal fractures can be successfully treated conservatively without weight-bearing restriction and without benefit of a cast with respect to a functional elasticated bandage.

Level of clinical evidence

level III retrospective comparative study.

Stress fractures of the foot and ankle, part 2: site-specific etiology, imaging, and treatment, and differential diagnosis

Stress fractures of the foot and ankle are a commonly encountered problem among athletes and individuals participating in a wide range of activities. This illustrated review, the second of two parts, discusses site-specific etiological factors, imaging appearances, treatment options, and differential considerations of stress fractures of the foot and ankle. The imaging and clinical management of stress fractures of the foot and ankle are highly dependent on the specific location of the fracture, mechanical forces acting upon the injured site, vascular supply of the injured bone, and the proportion of trabecular to cortical bone at the site of injury. The most common stress fractures of the foot and ankle are low risk and include the posteromedial tibia, the calcaneus, and the second and third metatarsals. The distal fibula is a less common location, and stress fractures of the cuboid and cuneiforms are very rare, but are also considered low risk. In contrast, high-risk stress fractures are more prone to delayed union or nonunion and include the anterior tibial cortex, medial malleolus, navicular, base of the second metatarsal, proximal fifth metatarsal, hallux sesamoids, and the talus. Of these high-risk types, stress fractures of the anterior tibial cortex, the navicular, and the proximal tibial cortex may be predisposed to poor healing because of the watershed blood supply in these locations. The radiographic differential diagnosis of stress fracture includes osteoid osteoma, malignancy, and chronic osteomyelitis.

The Biology of Bone and Ligament Healing

This review describes the normal healing process for bone, ligaments, and tendons, including primary and secondary healing as well as bone-to-bone fusion. It depicts the important mediators and cell types involved in the inflammatory, reparative, and remodeling stages of each healing process. It also describes the main challenges for clinicians when trying to repair bone, ligaments, and tendons with a specific emphasis on Charcot neuropathy, fifth metatarsal fractures, arthrodesis, and tendon sheath and adhesions. Current treatment options and research areas are also reviewed.

The peroneus brevis tendon at its insertion site on fifth metatarsal bone

BACKGROUND

The differences at the attachment site of peroneus brevis (PB) to the fifth metatarsal bone is important in terms of the forces exerted on the bone and hence the mechanism of fractures involving this structure. In this study, we investigated the anatomical properties of PB at the insertion site to the base of fifth metatarsal bone, its possible intertendinous connections with peroneus tertius (PT) and their possible effects on the fracture occurrence at the bony attachment site.

METHODS

The length and the width of PB tendons at their mid- and end-points were measured and classified according to the insertion types. Besides, the length and the width of the base of fifth metatarsal bone were assessed. The slips extending from the PB tendons and their relationship with PT were also evaluated. The data was compared statistically with each other and between the right and left sides.

RESULTS

The length of PB tendon was measured 79.57±15.40mm on the right side; 81.48±14.31mm on the left. The width of PB tendon at the mid-point was 4.46±0.80mm on the right side; 4.42±0.94mm on the left. The width of the tendon at its insertion point was measured 14.85±3.40mm and 15.16±3.42mm on the right and left sides respectively. PB was divided into three types according to its attachment to base of fifth metatarsal bone (5thMB). Type I, Type II and Type III were observed at the rates of 59.5%, 28.6% and 11.5% respectively. It was observed that the slips to the bone were extending more commonly from PB than from PT and that the large majority of them were single having their insertions on the base of the proximal phalanx of the fifth toe.

CONCLUSIONS

Knowing the width and insertional types of PB aids in understanding the mechanism of fractures at the site of bony attachment. The existence of slips may help the surgeon in the procedures involving PB or the lateral side of the forefoot.

Insertional Characteristics of the Peroneus Tertius Tendon: Revisiting the Anatomy of an Underestimated Muscle

The present study was performed to describe the morphologic characteristics of the peroneus tertius (PT) tendon, evaluate the variations in its insertion point, investigate the interconnections with the tendons of the extensor digitorum longus, and discuss whether these insertion differences of the muscle tension might have an effect on fracture formation. The length and width of the PT tendon and the width at its midpoint were measured in 44 lower extremities. The data obtained were compared statistically. The PT was found to occur in 2 types according to the number of tendons: type 1, a single tendon without a slip; and type 2, 2 tendons with a slip. It has been suggested that the PT tendon could contribute to avulsion fractures of the tuberosity of the fifth metatarsal bone. Therefore, to understand the mechanism of Jones fracture, knowledge of the PT tendon would be beneficial to determine the insertion points.

The fifth metatarsal base: anatomic evaluation regarding fracture mechanism and treatment algorithms

Fractures occurring within the 1.5-cm proximal portion of the fifth metatarsal are commonly considered avulsion fractures. The exact mechanisms of such fractures are controversial. The present study focused on determining the likely mechanism of fracture according to the exact anatomy to allow for more successful treatment. The research sample included 10 frozen cadaveric specimens. The lateral band of the plantar fascia, peroneus brevis, and articular surface were identified and separated from their attachments, thereby splitting the fifth metatarsal base into zones A, B, and C. In zone A, the attachment of the plantar fascia was 6.6 ± 2.2 mm from the inferior aspect, 9.5 ± 2.9 mm from the proximal aspect, and 11.5 ± 0.9 mm from the lateral aspect. In zone B, the attachment of the peroneus brevis was 12.0 ± 2.2 mm from the inferior aspect, 10.2 ± 2.2 mm from the proximal aspect, and 11.5 ± 0.9 mm from the lateral aspect. Zone C was measured from the border of zone B and encompassed the articulation of the fifth metatarsal to the cuboid. We propose that fractures occurring in the most proximal end of the fifth metatarsal, zone A, are caused by a lateral band of plantar fascia and might be able to be treated conservatively by immobilization with weightbearing. We also propose that fractures occurring in zones B and C result from traumatic tension on peroneus brevis and might need to be treated with strict immobilization and non-weightbearing or open reduction internal fixation.

Metatarsal fractures: A review and current concepts

Metatarsal fractures represent a significant proportion of foot injuries. Various patterns of metatarsal injuries exist and the resultant impact on function and quality of life is not negligible. This in fact reflected the attention given to these fractures in the medical literature. Conventionally, a complete clinical and radiological assessment is needed in order to guide management and tailor treatment options to the clinical and functional needs of the individual metatarsal fracture. This article provides a thorough review of all metatarsal fractures; it examines the latest literature especially in relation to management of distinct types of metatarsal fractures. Special attention is given to the first metatarsal due to its important implication in stable functionality of the first ray and foot. In relation to the higher incidence of fifth metatarsal fractures this article provides a broader review of their management.

Radiographic classification for fractures of the fifth metatarsal base

OBJECTIVE

Avulsion fractures of the fifth metatarsal base (MTB5) are common fore foot injuries. Based on a radiomorphometric analysis reflecting the risk for a secondary displacement, a new classification was developed.

MATERIALS AND METHODS

A cohort of 95 healthy, sportive, and young patients (age ≤ 50 years) with avulsion fractures of the MTB5 was included in the study and divided into groups with non-displaced, primary-displaced, and secondary-displaced fractures. Radiomorphometric data obtained using standard oblique and dorso-plantar views were analyzed in association with secondary displacement. Based on this, a classification was developed and checked for reproducibility.

RESULTS

Fractures with a longer distance between the lateral edge of the styloid process and the lateral fracture step-off and fractures with a more medial joint entry of the fracture line at the MTB5 are at higher risk to displace secondarily. Based on these findings, all fractures were divided into three types: type I with a fracture entry in the lateral third; type II in the middle third; and type III in the medial third of the MTB5. Additionally, the three types were subdivided into an A-type with a fracture displacement <2 mm and a B-type with a fracture displacement ≥ 2 mm. A substantial level of interobserver agreement was found in the assignment of all 95 fractures to the six fracture types (κ = 0.72). The secondary displacement of fractures was confirmed by all examiners in 100%.

CONCLUSIONS

Radiomorphometric data may identify fractures at risk for secondary displacement of the MTB5. Based on this, a reliable classification was developed.

Anatomy and biomechanical properties of the plantar aponeurosis: a cadaveric study

Objectives

To explore the anatomy of the plantar aponeurosis (PA) and its biomechanical effects on the first metatarsophalangeal (MTP) joint and foot arch.

Methods

Anatomic parameters (length, width and thickness of each central PA bundle and the main body of the central part) were measured in 8 cadaveric specimens. The ratios of the length and width of each bundle to the length and width of the central part were used to describe these bundles. Six cadaveric specimens were used to measure the range of motion of the first MTP joint before and after releasing the first bundle of the PA. Another 6 specimens were used to evaluate simulated static weight-bearing. Changes in foot arch height and plantar pressure were measured before and after dividing the first bundle.

Results

The average width and thickness of the origin of the central part at the calcaneal tubercle were 15.45 mm and 2.79 mm respectively. The ratio of the length of each bundle to the length of the central part was (from medial to lateral) 0.29, 0.30, 0.28, 0.25, and 0.27, respectively. Similarly, the ratio of the widths was 0.26, 0.25, 0.23, 0.19 and 0.17. The thickness of each bundle at the bifurcation of the PA into bundles was (from medial to lateral) 1.26 mm, 1.04 mm, 0.91 mm, 0.84 mm and 0.72 mm. The average dorsiflexion of the first MTP joint increased 10.16° after the first bundle was divided. Marked acute changes in the foot arch height and the plantar pressure were not observed after division.

Conclusions

The first PA bundle was not the longest, widest, or the thickest bundle. Releasing the first bundle increased the range of motion of the first MTP joint, but did not acutely change foot arch height or plantar pressure during static load testing.

Imaging of plantar fascia and Achilles injuries undertaken at the London 2012 Olympics

Plantar fascia and distal Achilles injuries are common in elite athletes. Acute athletic injuries of the plantar fascia include acute plantar fasciopathy and partial or complete tears. Underlying most acute injuries is a background of underlying chronic plantar fasciopathy. Injuries may affect the central or less commonly lateral portions of the fascia and acute tears are generally proximal. Athletic Achilles injuries may occur at the mid tendon or the distal insertion, and there may be an underlying chronic tendinopathy. Acute or chronic paratendinopathy may occur as a separate entity or combined with Achilles injury. In this article, the spectrum of athletic injuries of the plantar fascia and Achilles is described, illustrated by imaging findings from the London 2012 Olympic games.

Excision of symptomatic nonunions of proximal fifth metatarsal avulsion fractures in elite athletes

BACKGROUND

An avulsion fracture of the proximal fifth metatarsal may result in a symptomatic nonunion and hinder athletic performance. Nonoperative management is often successful in alleviating symptoms. When symptoms persist, surgery can be undertaken to repair the nonunion or excise the avulsed fragment.

PURPOSE

The excision of the avulsed bone fragment is evaluated in the management of symptomatic nonunions.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Excision of the avulsed fifth metatarsal fragment was performed in 6 male high-performance athletes with symptomatic nonunions. The remaining edge of bone was contoured and smoothed.

RESULTS

All 6 patients experienced an uneventful operation and recovery, returning to competitive play at a mean of 11.7 weeks. Activity-related pain and discomfort abated after the excision and rehabilitation. No surgical complications were noted.

CONCLUSION

Surgical excision of the avulsed fragment from the proximal fifth metatarsal is a safe and effective alternative intervention when nonoperative methods fail.

Variant insertion of the fibularis tertius muscle is an evidence of the progressive evolutionary adaptation for the bipedal gait

Fibularis tertius (FT) is often considered as part of extensor digitorum longus (EDL) muscle. The muscle is absent in hominoid apes and with the acquisition of the bipedal gait; the muscle emerged as a recent addition in the human foot. From its various modes of insertions, it is evident that the muscles of the sole are in search of its distal attachment, which can best support the relatively weak human midfoot. We describe an unusual insertion of the muscle in support of this hypothesis.

Advancements in percutaneous fixation for foot and ankle trauma

Operative fixation of foot and ankle trauma can be challenging. Often times, the soft tissue envelope can have extensive damage as a result of the fracture. In these cases, percutaneous fixation may be used. Percutaneous fixation can benefit both soft tissue and osseous healing when used correctly. Many techniques have been described in the literature that may help to preserve blood supply, minimize soft tissue dissection, and restore a functional limb. This article reviews general guidelines for fracture and soft tissue management, osseous healing of fractures, and how certain techniques influence fracture healing. It also illustrates certain techniques for specific fracture reduction.

Extremely proximal fractures of the fifth metatarsal in the developmental age

BACKGROUND

Numerous studies document the high incidence of this type of fracture of the foot in childhood due to the presence of the growth plate of the apophysis of the fifth metatarsal. Our aim in this study was to evaluate the presence and morphology of the growth nucleus and correlate its presence with fractures of the apophysis of the fifth metatarsal.

MATERIALS AND METHODS

Between 2001 and 2003, we reviewed the radiographs of 481 patients (558 feet) between 6 months and 16 years that were diagnosed with a fracture. We evaluated for the presence and morphology of the growth nucleus of the base of the fifth metatarsal in the 7- to 16-year age group because this is the time interval in which the nucleus becomes visible radiographically.

RESULTS

We identified the nucleus of the base of the fifth metatarsal in 115 patients for a total of 132 feet. A fracture of the fifth metatarsal was found in 12.8%. A misdiagnosis had been made in 47%. Misdiagnosis was strictly related to the presence of the growth nucleus of the apophysis except two cases where an accessory bone was present.

CONCLUSIONS

Our study demonstrated a much higher incidence of the presence of the growth nucleus than documented in previous reports and that its morphology varied widely in relation to the stage of maturity of the patient and the radiographic technique. Its presence led to a high rate of misdiagnosis of a fracture.

Fractures of the fifth metatarsal; diagnosis and treatment

Of all foot fractures the fifth metatarsal fracture is the most common. A complete clinical and radiological assessment is required to select the best treatment option. Nondisplaced tuberosity avulsion fractures can be treated non-operatively. Surgical treatment is indicated when the fracture is displaced more than 2mm or when more than 30% of the cubometatarsal joint is involved. Non or minimally displaced shaft fractures can be treated non-operatively. If the dislocation is more than 3-4mm or the angulation is more than 10 degrees, percutaneous K-wires, plate or screw fixation is indicated. The Jones fracture is known for prolonged healing time and non-union. The indication for surgical treatment of Jones' fractures depends on activity level and Torg classification: type I fractures are treated non-operatively. Type II fractures can be treated non-operatively or operatively, depending on patient activity level. Type III fractures have more complications and should be treated operatively. Several operation techniques have been described.

Basketball injuries in children

Basketball is a popular, worldwide sport played outdoors and indoors year-round. Patterns of injury are related to abrupt changes in the athlete's direction, jumping, contact between athletes, the hard playing surface and paucity of protective equipment. Intensity of play and training in the quest of scholarships and professional careers is believed to contribute to an increasing occurrence of injury. Radiologists' appreciation of the breadth of injury and its relation to imaging and clinical findings should enhance the care of these children. Some of the patterns of injury are well known to radiologists but vary due to age- and size-related changes; the growing skeleton is affected by differing susceptibilities from biomechanical stresses at different sizes. Beyond screening radiographs, the accuracy of MRI and CT has improved diagnosis and treatment plans in this realm. Investigations to detect symptoms and signs in an attempt to prevent the tragedy of sudden cardiac death in basketball players may lead to MRI and CTA studies that compel radiologists to evaluate cardiac function along with myocardial and coronary artery anatomy. Worthy of mention also is the female athlete triad of disordered eating, amenorrhea, and osteoporosis that is observed in some young women participating in this and other sports.

The complicated Jones fracture, including revision and malalignment

Using radiographs culled over a 33-month period, the treatment, complications, revision, and rehabilitation of complicated Jones fractures and stress fractures involving the proximal diaphysis are examined. Although the non-operative approach remains viable, the exigencies and desires of the athletic and leg-based working population require sooner-rather-than-later return to play or work. Fortunately, these needs can be matched by the available and functioning orthopedic practice of intramedullary screw fixation. This practice is coupled with prevention, reliable orthopedic techniques, the orthopedist's surgical skills, and devices necessary for successful surgery. Recent attention directed toward handling complications promise better, quicker, and more reliable recovery for the patient.

Percutaneous fixation of forefoot, midfoot, hindfoot, and ankle fracture dislocations

Open reduction with rigid internal fixation is the basic principle for surgical management in foot and ankle trauma. High-risk patients present a surgical dilemma for the foot and ankle surgeon because the possible complications are magnified in this patient population. Percutaneous fixation is a unique alternative for achieving anatomic stabilization without increased physical strain to the patient. The significant advantages of percutaneous fixation include minimizing damage to the vascular supply, maintaining and preserving a stable soft tissue envelope, and decreasing the potential risk for infection. This article provides an overview of percutaneous surgical fixation methods and their role in foot and ankle trauma for the high-risk patient.

MDCT-Klassifikation knöcherner Verletzungen des oberen Sprunggelenks und des Fußes

Conventional radiography plays an essential role in the primary evaluation of acute ankle and foot trauma. In the case of complex injuries, however, subsequent computed tomography (CT) is nowadays recommended. In this connection, multidetector computed tomography (MDCT) allows better temporal, spatial, and contrast resolution compared with the conventional single-slice spiral CT. Multiplanar reformation and three-dimensional reconstruction of the acquired data sets are also helpful tools for critical assessment of therapeutic intervention. This report reviews the potential of the MDCT technique for accurate fracture classification, precise illustration of displaced components, and postoperative control of arrangement of typical lesions.

Metatarsal shaft fractures and fractures of the proximal fifth metatarsal

Metatarsal fractures represent a relatively common injury, especially in athletes. The pertinent anatomy, evaluation, diagnosis, classification, and treatment of acute and chronic (stress) metatarsal shaft fractures are discussed. Fractures of the proximal fifth metatarsal, which are unique and important injuries, are also discussed. Treatment remains relatively straightforward for the traumatic metatarsal injury, whereas traditional stress fractures typically heal with decreased activity. The problematic proximal fifth metatarsal fracture (Jones fracture) frequently requires surgical intervention in patients who want to avoid non-weight-bearing cast immobilization. The authors' current treatment for this fracture includes the option of intramedullary fixation versus cast immobilization.

Fractures of the forefoot

Fractures of the forefoot are common injuries of various causes. Although not crippling, forefoot fractures can be debilitating if they go undiagnosed or are mistreated. Whenever patients complain of foot pain with ambulation or difficulty ambulating, radiographs should be taken as part of a standard routine to assess for bony pathology. This article discusses the classification and treatment of metatarsal fractures, digital and sesamoid fractures, and open fractures about the forefoot.