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

Is the Diagnosis of fifth Metatarsal Fracture Type Consistent? An Interobserver Reliability Study

Background

Treatment pathways of fifth metatarsal fractures are commonly directed based on fracture classification, with particular proximal fractures typically requiring closer observation and possibly more aggressive management. Our aim is to investigate the interobserver reliability of assessment of subtypes of fifth metatarsal fractures.

Methods

We included all patients referred to our virtual fracture clinic with a suspected or confirmed fifth metatarsal fracture. Plain anteroposterior radiographs were reviewed by 2 novice observers, initially trained on the fifth metatarsal classification identification. Eight different zones were defined based on anatomical location. Patients were excluded from analysis if neither observer could identify a fracture. An interobserver reliability analysis using Cohen κ coefficient was carried out, and degree of observer agreement described using Landis and Koch's description. All data were analyzed using IBM SPSS, version 27.

Results

A total of 1360 patients who met the inclusion criteria were identified. The 2 observers had moderate agreement when identifying fractures in all zones, apart from zone 1.2 and distal metaphysis (DM) fractures, which only achieved fair agreement (κ = 0.308 and 0.381 respectively). Zone 3 has slight agreement with zone 2 proximally, and there is an apparent difficulty with distal diaphyseal shaft (DS) fractures, resulting in a lot of crossover with DM, achieving a fair level of agreement (DS 312 vs 196; DM 120 vs 237; κ = .398, P < .001).

Conclusion

Reliability of subcategorizing fifth metatarsal fractures using standardized instructions conveys moderate agreement in most cases. If the region of the fracture is going to be used in an algorithm to guide a management plan and clinical follow-up during a virtual clinic review, defining fractures of zones 1-3 needs careful consideration.

Level of Evidence

Level III, retrospective cohort study.

Clinical and Radiographic Healing of Nonoperative and Operative Treatment of Jones Fractures

BACKGROUND

Significant heterogeneity in the classification and treatment of zone 3 proximal fifth metatarsal base fractures ("true Jones fractures") exists. This study compared time to clinical and radiographic healing between patients treated operatively and nonoperatively. We hypothesized that patients treated nonoperatively may demonstrate a greater time to clinical healing.

METHODS

This was a retrospective cohort study of patients presenting to a large, urban, academic medical center with "Jones" fractures between December 2012 and April 2022. Jones fractures were defined as fifth metatarsal base fractures occurring in the proximal metadiaphyseal region, distal to the articulation of the fourth and fifth metatarsals on the oblique radiographic view. Clinical healing was the time point at which the patient had returned to their baseline ambulatory status with no tenderness to palpation. Radiographic healing was the presence of bridging callus across at least 3 cortices.

RESULTS

A total of 2450 patients presented with fifth metatarsal fractures, and 166 fractures (6.8%) were true Jones fractures. Among patients with Jones fractures, 120 patients with 121 Jones fractures followed up at our institution and were included in the analysis (mean age 46.5 ± 18.5 years). Ninety-nine fractures (81.8%) were treated nonoperatively and 22 fractures (18.2%) operatively. There were no differences between nonoperative and operative groups in time to clinical healing (12.7 ± 7.1 vs 12.8 ± 4.8 weeks, P = .931) or radiographic healing (13.2 ± 8.1 vs 11.7 ± 5.9 weeks, P = .331). Overall healing rate was 96% for the nonoperative group compared with 96.2% for the operative group.

CONCLUSION

In this study, nonoperative and operative treatment of true Jones fractures were associated with equivalent clinical and radiographic healing. The rate of delayed union in true Jones fractures was lower than previously described, and there was no difference in delayed union rate between nonoperative and operative management.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Zone 2 Fifth Metatarsal Fractures Treated Nonoperatively Have Similar Time to Healing to Those Treated Operatively

OBJECTIVES

To quantify the rate of union and time to clinical and radiographic healing in Zone 2 proximal fifth metatarsal (MT) fractures and compare these outcomes between Zone 2 fractures treated operatively and nonoperatively.

METHODS

DESIGN

Retrospective cohort study.

SETTING

Academic Level I Trauma Center.

PATIENT SELECTION CRITERIA

Patients with fifth MT fractures who presented between December 2012 and April 2022 and confirmed to have Zone 2 fractures (defined as fractures entering the proximal 4-5 MT articulation on the oblique radiographic view) were included in the study analysis in either the operative or nonoperative cohort.

OUTCOME MEASURES AND COMPARISONS

Nonunion, time to clinical healing by, and time to radiographic healing between operative and nonoperative treatment.

RESULTS

Among the 499 included patients, 475 patients (95.2%) were initially treated nonoperatively and 24 patients (4.8%) were treated operatively. Both groups were similar in demographics. There was no difference in the proportion of patients with nonunions between groups (6.1% in the nonoperative group vs. 3.8% in the operative group, P = 1.000). In addition, there was no statistically significant difference between groups with respect to the time to clinical healing (9.9 ± 8.3 weeks for the nonoperative group vs. 15.4 ± 15.0 weeks for the operative group, P = 0.117) or the time to radiographic healing (18.7 ± 12 weeks for the nonoperative group vs. 18.5 ± 16.6 weeks for the operative group, P = 0.970).

CONCLUSIONS

Zone 2 fifth MT base fractures were successfully treated with nonoperative management. There was no evidence in this study that operative treatment leads to significantly faster clinical or radiographic healing.

LEVEL OF EVIDENCE

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

Anthropometric measurements of the foot cannot predict the screw diameter for fifth metatarsal fractures intramedullary fixation

PURPOSE

The present study aimed to evaluate the accuracy of anthropometric foot measurements in predicting the diameter of the intramedullary screw for fifth metatarsal fracture fixation. Secondary aim was to identify whether the fifth metatarsal intramedullary canal diameter is correlated to the fifth metatarsal length and the foot dimensions.

METHODS

In 29 cadaveric feet, the maximum length of the plantar surface of the foot (PL) and the perimeter of the foot at the level of the fifth metatarsal base (PBFM) were measured using a measuring tape. Subsequently, the fifth metatarsal was excised. Using Computed Tomography scan, the metatarsal length (FML), and the horizontal (HDI) and vertical diameter (VDI) at the isthmus level were measured. The HDI values were grouped in 5 mm increments to correspond to the recommended screw diameter (RSD) for intramedullary fixation. A univariate linear regression analysis considered RSD and HDI as the dependent variables and FML, PL, PBFM as the independent variables. A multivariate regression analysis was performed to examine the predictive value of the two anthropometric measurements. A p-value < 0.05 was considered statistically significant.

RESULTS

All six univariate analyses revealed that the dependent variable was significantly correlated with the independent variable. However, the multivariate regression models showed that the anthropometric measurements were not significantly correlated with the RSD and HDI.

CONCLUSION

The current study found an association between the fifth metatarsal intramedullary canal diameter and the fifth metatarsal length and foot anthropometric dimensions. However, the anthropometric measurements of the foot presented a low predictive value for the decision of an intramedullary screw diameter in the treatment of fractures of the base of the fifth metatarsal.

Calcaneal Fractures Management, Change of Clinical Practice in Recent Years from ELA to STA: A Systematic Review and Meta-Analysis

Background

Calcaneal fractures are serious injuries that mainly affect young, active people. As a result, these fractures may cause long-term impairment and have a major socioeconomic impact. The current updated systematic review and meta-analysis were conducted to evaluate the functional outcomes, re-operative risk, and complications associated with the treatment of displaced intra-articular calcaneal.

Methodology

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to conduct this meta-analysis. The literature search was carried out using PubMed, Cochrane, MEDLINE, Google Scholar, and the EMBASE databases with the appropriate keywords.

Results

A total of 13 studies were included in this review. The follow-up months were diverse, ranging between 12 and 65 months in sinus tarsi approach (STA) and 12 to 76 months in extended lateral approach (ELA) methods. Time to surgery was shorter for the STA when compared to ELA (MD: 3.48; 95% CI 2.43 to 4.53; p < 0.00001). No significant difference was observed in functional outcomes between STA and ELA (MD: 0.34; 95% CI: -0.37 to 1.04; p = 0.35 > 0.05; I2 = 88%). In comparison to the ELA, the STA has significantly less wound healing complications (RR: 0.20; 95% CI 0.11 to 0.36; p 0.00001; I2 = 0%).

Conclusion

In conclusion, the STA technique in treating calcaneal fractures was significantly safer and more effective when compared to the ELA methods. The STA method of treatment was found to have a lower risk of complications and an infection rate, as well as a shorter operating and recovery time.

Classification of avulsion fractures of the fifth metatarsal base using three-dimensional CT mapping and anatomical assessment: a retrospective case series study

Background

To clarify the injury mechanism of the avulsion fracture of the fifth metatarsal combining 3-dimensional (3D) fracture mapping with anatomical measurements.

Methods

Two hundred twenty-two patients with the avulsion fractures of the fifth metatarsal base, who were admitted to our hospital from August 2015 to August 2020. The computed tomography (CT) scans were used to generate the 3-D images of all mapped fracture lines for the avulsion fractures of the fifth metatarsal base were compiled in an overall 3D image. The fifth metatarsal base of 8 unpaired lower limbs of adult Asian frozen cadaveric specimens were also dissected to observe and measure the specific locations of the attachment points of the peroneus brevis, lateral band of the plantar fascia, and peroneus tertius to the fifth metatarsal base.

Results

Based on the type of fracture line produced and the specific locations of the attachment points of the tendons or fascia, the avulsion fractures of the fifth metatarsal base can be classified into three types: type I predominantly involves the action of the lateral band of the plantar fascia; type II predominantly involves the action of the peroneus brevis; type IIIA involves the joint action of the peroneus brevis and lateral band of the plantar fascia with one fracture line, and type IIIB involves the joint action of the peroneus brevis and lateral band of the plantar fascia with two fracture lines.

Conclusion

The lateral band of the plantar fascia and peroneus brevis play a major role, either separately or together, in avulsion fractures of the fifth metatarsal base. With this knowledge, we propose a novel classification based on the injury mechanism, which can serve as a reference for clinical treatment and diagnosis.

Level of evidence

Level III, retrospective case series.

What Is the Interrater and Intrarater Reliability of the Lawrence and Botte Classification System of Fifth Metatarsal Base Fractures?

BACKGROUND

Fractures of the proximal fifth metatarsal are common, and often they are classified using a three-part scale first proposed by Lawrence and Botte. A clear consensus on prognosis and treatment for these fractures is lacking, particularly for fractures in the middle classification, Zone 2; the reliability of the classification scheme itself may be partly at fault for this. The intra- and interrater reliability of the classification itself has never been established, and it remains unclear whether the three-part classification of fifth metatarsal fractures can be applied consistently enough to guide treatment.

QUESTIONS/PURPOSES

When used by experienced orthopaedic surgeons, (1) What is the overall interrater reliability of the three-part Lawrence and Botte classification of fifth metatarsal base fractures? (2) What is the overall intrarater reliability of the three-part Lawrence and Botte classification of fifth metatarsal base fractures? (3) What are these same metrics for the individual transitions within the classification (Zone 1-2 and Zone 2-3)?

METHODS

Thirty sets of initial presentation radiographs representing an equal number of fractures originally diagnosed by treating clinicians as Zone 1, Zone 2, and Zone 3 were evaluated and classified by three orthopaedic surgeons specializing in foot and ankle surgery and eight foot and ankle fellows to determine interrater reliability. Two weeks later, the same set of radiographs were reevaluated in random order to determine intrarater reliability. Kappa values for interrater and intrarater reliability were calculated. Additionally, the individual transitions between zones were separately analyzed by calculating kappa values for a hypothetical two-part classification based on each transition.

RESULTS

The three-part Lawrence and Botte classification of fifth metatarsal fractures demonstrated an overall interrater agreement of κ = 0.66 (observed agreement 77% versus chance agreement 33%). Intrarater reliability for the 11 surgeons ranged from κ = 0.60 to κ = 0.90. A two-part scheme divided by the transition between Zone 1 and Zone 2 demonstrated an interrater agreement of κ = 0.83, and a two-part scheme divided by the transition between Zone 2 and Zone 3 demonstrated a much lower interrater reliability of κ = 0.66.

CONCLUSION

The three-part Lawrence and Botte classification system demonstrated a concerningly low level of interrater reliability with an observed agreement of 77% compared with a chance agreement of 33%. The primary source of concern is the assessment of the interface between Zone 2 and Zone 3, which proved much less reliable than that between Zone 1 and Zone 2. This suggests that previous studies of isolated Zone 1 fractures likely contain a homogeneous fracture cohort, whereas studies of Zone 2 or Zone 3 fractures are likely to include a mixture of fracture types. In practice, the consensus treatment of fifth metatarsal fractures differs based on whether they represent a more proximal, avulsive injury or a more distal injury from indirect trauma. Our data suggest that the Lawrence and Botte classification should be abandoned. Further work should focus on developing a new classification scheme that demonstrates improved interobserver reliability and more directly corresponds to this treatment paradigm.

LEVEL OF EVIDENCE

Level III, diagnostic study.