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Demographics and Functional Outcome of Toe Fractures
The Journal of Foot & Ankle Surgery 50 (2011) 307–310
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org
Demographics and Functional Outcome of Toe Fractures Sabine T. Van Vliet-Koppert, MD 1, Hamit Cakir, MD 2, Esther M.M. Van Lieshout, PhD 3, Mark R. De Vries, MD, PhD 4, Maarten Van Der Elst, MD, PhD 4, Tim Schepers, MD, PhD 4, 5 1
Orthopedics Resident, Department of General Surgery and Traumatology, Reinier de Graaf Groep, Delft, The Netherlands Surgery Resident, Department of General Surgery and Traumatology, Reinier de Graaf Groep, Delft, The Netherlands 3 Research Coordinator, Trauma Surgery, Department of Surgery-Traumatology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands 4 Trauma Surgeon, Department of General Surgery and Traumatology, Reinier de Graaf Groep, Delft, The Netherlands 5 Trauma Surgeon, Department of Surgery-Traumatology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands 2
a r t i c l e i n f o
a b s t r a c t
Level of Clinical Evidence: 2 Keywords: epidemiology foot fracture injury outcome phalanx toe
Toe fractures are common; however, there are few data on demographics and functional outcome. We studied outcomes in 339 consecutive patients with toe fractures treated between January 2006 and September 2008. Two hundred and sixty-four patients, aged 16 to 75, were mailed an outcome questionnaire, and overall subjective satisfaction with the outcome of treatment was measured using a visual analog scale (VAS). Most frequently affected were the first (38%) and fifth (30%) toes, and most (75.6%) of the fractures were caused by stubbing or crush injury. More than 95% of the fractures were displaced less than 2 mm, and all of the fractures were treated conservatively. The questionnaire was returned by 141 (53%) patients with a median follow-up of 27 months. Respondents were female in 57.4% of cases and had a median age of 45 years. The median AOFAS score was 100 (P25, P75 ¼ 93,100) points; the median VAS was 10 (P25, P75 ¼ 8, 10) points. Univariate regression analysis revealed no statistically significant associations between outcome and the particular toe or phalanx involved, number of fractured toes, fracture type and location, articular involvement, gender, age, body mass index, smoking habits, and the presence of diabetes mellitus. Satisfaction VAS was dependent on age (P ¼ .047) and gender (P ¼ .049) in the multivariate analysis. The AOFAS midfoot score was not influenced by any of the covariates. This is the first epidemiological investigation using 2 outcome-scoring systems to determine function and satisfaction following treatment of toe fractures. Ó 2011 by the American College of Foot and Ankle Surgeons. All rights reserved.
Digital fractures are among the most common fractures of the foot, with an incidence ranging from 14.0 to 39.6 patients per 10,000 persons per year (1–4). Their prevalence varies from 3.0% of fractures in children to 3.6% of all fractures in adults (1–4). However, previous studies lack data on demographics and digital fracture patterns. Almost all toe fractures, particularly the lesser toes, can be treated conservatively with expectation of a satisfactory outcome (3, 5–7). To date, the functional outcome and patient satisfaction after a toe fracture have not been investigated. The primary aim of this investigation was to evaluate the demographics of toe fractures in a Level 2 trauma center, providing care for a patient population of more than 300,000. The secondary aim was to determine the functional outcome and patient satisfaction after treatment for a digital fracture of the foot as determined using validated outcome-scoring systems. Financial Disclosure: This study was financially supported by the WAC (Wetenschappelijke Activiteiten Commissie) of the Reinier de Graaf Groep Delft. Conflict of Interest: None reported. Address correspondence to: Tim Schepers, MD, PhD, Trauma Surgeon, Department of Surgery-Traumatology, Erasmus Medical Center, University Medical Center Rotterdam, Room H-822k, PO Box 2040, 3000 CA Rotterdam, The Netherlands. E-mail address: [email protected] (T. Schepers).
Patients and Methods Demographics All consecutive patients with a toe fracture caused by an isolated trauma to the foot, between January 1, 2006, and June 31, 2008, were extracted from the Emergency Department registries, following approval of the local medical ethics board. The initial radiographs performed at the Emergency Department were reevaluated by 2 observers (T.S., S.T.V.). Patient characteristics (eg, age, body mass index [BMI], gender, diabetes, smoking habits, and side of injury) were collected. Data on the fracture characteristics (ie, which toe and phalanx were involved, the number of involved toes, joint involvement, type of fracture [transverse, oblique/spiral, comminution, or avulsion], the fracture level [distal, shaft, proximal], the amount of displacement [zero, < 2 mm, 2 to 5 mm, and > 5 mm], and the trauma mechanism (supination, fall from height, crush, stub, or stress fracture) were abstracted from the medical records. Treatment for all patients was carried out according to hospital protocol. Patients with a fracture of the great toe were treated with a cast for 3 weeks initially. Fractures of 1 or more of the lesser toes were treated with splinting to the adjacent intact toe, and patients were advised to wear a rigid-sole shoe. Functional Outcome Questionnaire A postal survey was developed according to existing guidelines to optimize response rates (8). The recommendations of the American Association for Public Opinion Research (AAPOR) were carefully followed (9). All patients between 16 and 75 years old were sent
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a questionnaire containing the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and a single-question 10-cm visual analog scale (VAS) pertaining to subjective patient satisfaction. As physical examination of the patients (range of motion of the toe joints) was not possible, the hallux and lesser metatarsophalangealinterphalangeal AOFAS scores could not be applied, as they rely heavily on the range of motion of the toes. The AOFAS midfoot score was introduced by Kitaoka et al in 1994 (10). It includes questions pertaining to pain, activity and functional limitations, footwear, walking distance, difficulties with different terrains, gait, and alignment (whether or not plantigrade). The 7 questions relate to 3 components: pain (1 question; maximum 40 points), function (5 questions; maximum 45 points), and alignment (1 question; maximum 15 points), leading to a total possible score of 100 points. The question related to alignment was completed by a physician, based on information abstracted from the patient records and radiographs; the patient answered all of the other questions. The VAS was used to measure overall patient satisfaction with the outcome (range 0 to 10 cm) (11). In addition, patients were asked about their ability to run, walk on their toes, and walk barefoot. After 3 weeks, the nonrespondents were sent a reminder letter, including another copy of the questionnaire and a return envelope. Statistical Analysis The statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 16.0 (SPSS, Chicago, IL). The Kolmogorov-Smirnov test was used to test for normality of the numeric data. Levene’s test was applied to assess homogeneity of variance between data. Because most numeric variables did not show normal distribution or equal variance, all items were regarded as nonparametric for the statistical analysis. MannWhitney U tests were performed to assess statistical differences in AOFAS and VAS scores between subgroups (eg, males versus females, smoking versus nonsmoking, absence versus presence of diabetes, first digit fractures, and multiple fractures). Numeric data are expressed as medians with the 25th to 75th percentile (P25 to P75) range; categorical data are shown as counts and percentages. Logistic regression models were subsequently developed to correct for gender, age, diabetes, smoking habits, BMI, fracture type, and fracture dislocation (displacement). A P value < .05 was considered statistically significant.
Results Demographics In the 30-month study period, 339 patients with 368 digital and 370 phalangeal fractures of the foot were identified. Two patients had 2 concurrent phalangeal fractures in the same digit. There were 172 (50.7%) males and 167 (49.3%) females in the cohort. The median age of the group was 35.2 (19.3 to 53.5) years; the male patients had a median age of 26.0 (15.0 to 44.7) years, and female patients had a median age of 43.3 (26.1 to 58.6) years. Patients 5 years or younger accounted for 2.7% of all patients, and those 12 years or younger represented 15% of the study population. The right side was involved in 177 (51.9%) patients and the left side in 164 (48.1%). In 2 cases, a bilateral digital injury was encountered, but with an interval of several weeks between the injuries. With regard to the distribution of fractured digits, the first toe accounted for 141 (38.1%) fractures, the second toe accounted for 40 (10.8%), the third toe accounted for 26 (7%), the fourth toe accounted for 50 (13.5%), and the fifth toe accounted for 113 (30.5%) (Figure 1). Multiple digital fractures were observed in 5.9% of the toes (2 toes [4.4%], 3 toes [0.9%], and 4 toes [0.6%]). With regard to the mechanism of trauma, stubbing was most prevalent and accounted for 51.6% of the fractures, whereas 24% were a result of crush injury, and 11.2% were a result of supination (ankle and foot inversion) injury. With regard to the degree of fracture displacement, 97% of the fractures were either non- or minimally (< 2 mm) displaced. With regard to the orientation of the fracture, 33% of the fractures were transverse, 41% were spiral or oblique, 13% were comminuted, and 13% were avulsion injuries. Involvement of the phalangeal joint surface was noted in 122 (33%) of the phalangeal fractures, and they occurred predominately at the base of the phalanx. All of the digital fractures were treated conservatively. Functional Outcome Questionnaire A total of 141 (53%) of 264 patients between 16 and 75 years of age returned the questionnaire with a median follow-up of 27.3 (21.2 to
Fig. 1. Distribution of toe (n ¼ 368) and phalangeal (n ¼ 370) fractures according to their location.
39.0) months. Respondents were female in 57.4% of cases, and the median age for the respondents was 44.7 (30.8 to 58.3) years. The median BMI for the respondents was 23.9 (21.6 to 26.0). In 46.8% of the patients the left side was affected. A total of 7.4% of the patients had diabetes and 25.7% were smokers. In the respondent group, 66 (47%) patients were treated by splinting the fractured toe to an adjacent toe, and 44 (31%) were treated with a cast. Three (2%) patients were treated without the use of a splint or a cast. With regard to self-reported activity level, 84.4% of the responders reported being able to run, 75.2% to walk on their toes, and 82.3% to walk barefoot. Twenty-five (18%) patients failed to answer the questions about activity level. The median AOFAS midfoot score was 100 (93 to 100) points, with an AOFAS functional subscore of 45 (45 to 45). The median satisfaction VAS was 10 (8 to 10) points. Respondents were comparable to nonrespondents, except for age (44.7 versus 36.9 years, respectively).
Table 1 Functional outcome scores per subgroup (n ¼ 141 patients)* Patient or Fracture Characteristic Smoking Yes No Diabetes Yes No Gender Male Female Hallux fracture Yes No Number of fractures Single Multiple Fracture location Extra-articular Intra-articular Displacement 2 mm > 2 mm
VAS
AOFAS Functional Score
AOFAS Total Score
9 (8, 10) 10 (8, 10)
45 (45, 45) 45 (45, 45)
100 (90, 100) 100 (93, 100)
9 (8, 10) 10 (8, 10)
45 (43, 45) 45 (45, 45)
93 (89, 100) 100 (93, 100)
10 (8, 10) 10 (8, 10)
45 (45, 45) 45 (45, 45)
100 (93, 100) 100 (93, 100)
10 (8, 10) 10 (8, 10)
45 (44, 45) 45 (45, 45)
100 (93, 100) 100 (93, 100)
10 (8, 10) 9 (8, 10)
45 (45, 45) 45 (45, 45)
100 (93, 100) 100 (80, 100)
10 (8, 10) 9 (8, 10)
45 (45, 45) 45 (45, 45)
100 (93, 100) 100 (93, 100)
10 (8, 10) 10 (7, 10)
45 (45, 45) 44 (39, 45)
100 (93, 100) 93 (78, 96)
Abbreviations: AOFAS, American Orthopaedic Foot and Ankle Society; VAS, visual analog scale (satisfaction). * Data are shown as medians with the P25 to P75 between parentheses. Data analyzed using the Mann-Whitney U test.
S.T. Van Vliet-Koppert et al. / The Journal of Foot & Ankle Surgery 50 (2011) 307–310
Statistical Analysis As for the inferential statistical analyses, no differences in outcome were identified with regard to which toe or phalangeal bone was affected, the number of fractured toes, fracture type and location, joint involvement, gender, age, BMI, smoking habits, or the presence of diabetes mellitus (Table 1). A statistically significant correlation was found between the AOFAS overall score, the AOFAS functional subscore, and satisfaction VAS (Table 2). These outcome scores showed no significant correlation with age or BMI (P > .05). The univariate regression analyses revealed a weak association between increased dislocation (fracture displacement) and lower AOFAS scores, although this was not statistically significant (P ¼ .058). In the multivariable analysis, the VAS was dependent on age (P ¼ .047) and gender (P ¼ .049). The AOFAS midfoot score was not statistically significantly influenced by any of the parameters in the multivariable analysis.
Discussion The current study of 339 patients with 368 digital and 370 phalangeal fractures provides insight into one of the most common fractures of the foot. Males and females were equally represented in the current study, as opposed to previous studies in which a male predominance of 62% to 66% was reported (3–11). The study by Rennie et al (4), on pediatric fracture epidemiology, showed a similar age distribution as the current investigation. No comparison could be made with distribution data in the literature for adults (1–3). The number of great toe fractures in this study (38%) is higher than previously reported (17%–24%) (2). This difference might be because of the inclusion of pediatric patients, in whom a higher incidence of first digital fractures was seen (41.9% in patients younger than 16 years). The median age of 35.2 years was similar to the age reported by Court-Brown and Caesar (1), who reported an average age of 35.3 years with exclusion of patients younger than 12 years. Rennie et al (4), looking at patients younger than 16 years, found an average age of 10.9 years for patients presenting with toe fractures. The secondary aim of this study was to evaluate functional outcome scores after the conservative treatment of toe fractures. Patients were sent a postal questionnaire so as to obtain the highest possible response rate. Hence, physical examination of the patients for range of motion of the toe joints was not possible. Therefore, we applied the AOFAS midfoot scale in the current study. The outcome scores in this population were excellent with a median of 100 (93–100) points (AOFAS) and 10 (8–10) points satisfaction (VAS). Despite the response rate of 53%, we can conclude that patient satisfaction after conservative treatment of toe fractures is high. We were not able to find any studies in the literature using outcome scores in toe fractures, and comparisons with historical controls were therefore not possible.
Table 2 Correlation between outcome scores, age, and BMI (n ¼ 141 patients) Patient or Fracture Characteristic
VAS
AOFAS Functional Score
AOFAS Total Score
VAS AOFAS functional score AOFAS total score Age BMI
NA 0.406* 0.530* 0.112 0.112
0.406* NA 0.668* 0.041 0.160
0.530* 0.668* NA 0.039 0.115
Spearman Rank Correlation coefficients per Spearman’s rank correlation test. Abbreviations: AOFAS, American Orthopaedic Foot and Ankle Society; BMI, body mass index; NA, not applicable; VAS, visual analog score (satisfaction). * P < .001.
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Because of the overall excellent scores for both the AOFAS midfoot score and the VAS, few predictors of outcome could be identified by the statistical analysis. However, our statistical analysis revealed a tendency toward the association of lower AOFAS scores with more displaced fractures in the univariate analysis, although this association was not statistically significant. Furthermore, there was no significant difference in outcome based on type and location of the fracture. In their review on the management of toe fractures, Hatch and Hacking (6) confirmed that most toe fractures treated conservatively led to an excellent functional outcome; however, they did not report an outcome score. In our fully adjusted multivariate analysis, lower satisfaction (VAS) with the overall outcome was associated with younger female patients, and this finding was consistent with earlier findings that female gender is a predictor of a less favorable outcome in ankle fractures (12). These results may be because of a patient population with high expectations related to the desire to wear fashionable shoe gear. We recognize a number of methodological limitations that could have influenced the validity of our results. Because physical examination of the patients, in particular assessment of digital range of motion, was not performed, we were not able to use the AOFAS hallux and lesser metatarsophalangeal-interphalangeal scoring scale. Despite this shortcoming, however, we believe that the scoring scale that we used conveyed face validity and, for this reason, was found to be useful for our purposes. We also understand that potential biases could be associated with data input into the medical record system, and thus ascertainment of eligible cases and the study variables of interest could have been affected by this. By the same token, use of the postal system conveys certain known selection biases, and this could have influenced the rate of participation with regard to our questionnaire. Furthermore, the patient population used in this study did not include those treated by a general practitioner or those who did not seek any medical attention at all; therefore, the incidence of toe fractures reported herein could be an underestimation. In fact, previous studies reported an incidence of 14 to 40 per 10,000 patients (1, 2). This study is the first epidemiological exploration of functional outcomes following toe fractures, and showed that more than 95% of such fractures are either non- or minimally displaced. Three-quarters of the fractures were transverse, oblique, or spiral, and in more than 75% of the cases the mechanism of injury was stubbing of the digit or a crush injury. An excellent outcome was obtained with conservative treatment, as measured by the AOFAS midfoot score and 10-cm satisfaction VAS after a median of 27 months of follow-up. Based on our findings in this study, as well as our understanding of the foot surgical literature, conservative treatment of toe fractures is generally associated with excellent outcome scores and high patient satisfaction with the results of treatment. Young female patients reported slightly less favorable outcomes, and a there was a tendency for a less favorable outcome in association with increased displacement at the fracture site. The distribution, patient, and fracture characteristics provided by this study may aid in the planning of future clinical trials concerning different treatment modalities for this common form of pedal trauma.
References 1. Court-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury 37:691–697, 2006. 2. Schnaue-Constantouris EM, Birrer RB, Grisafi PJ, Dellacorte MP. Digital foot trauma: emergency diagnosis and treatment. J Emerg Med 22:163–170, 2002. 3. Mittlmeier T, Haar P. Sesamoid and toe fractures. Injury 35(Suppl 2):SB87–SB97, 2004. 4. Rennie L, Court-Brown CM, Mok JY, Beattie TF. The epidemiology of fractures in children. Injury 38:913–922, 2007. 5. Cobey JC. Treatment of undisplaced toe fractures with metatarsal bar made from tongue blades. Clin Orthop Relat Res 56(103), 1974.
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6. Hatch RL, Hacking S. Evaluation and management of toe fractures. Am Fam Physician 68:2413–2418, 2003. 7. MacManus JE. The use of a plaster slipper in the management of simple fractures of the toes. Am J Surg 54:721–722, 1941. 8. Edwards P, Roberts I, Clarke M, DiGuiseppi C, Pratap S, Wentz R, Kwan I. Increasing response rates to postal questionnaires: systematic review. BMJ 324:1183, 2002. 9. Johnson T, Owens L. Survey response rate reporting in the professional literature. Paper presented at the 58th Annual Meeting of the American Association for Public Opinion Research, May 2003, Nashville, TN.
10. Kitaoka HB, Alexander IJ, Adelaar RS, Nunley JA, Myerson MS, Sanders M. Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int 15:349–353, 1994. 11. Schepers T, Schipper IB, Vogels LM, Ginai AZ, Mulder PG, Heetveld MJ, Patka P. Percutaneous treatment of displaced intra-articular calcaneal fractures. J Orthop Sci 12:22–27, 2007. 12. Egol KA, Tejwani NC, Walsh MG, Capla EL, Koval KJ. Predictors of short-term functional outcome following ankle fracture surgery. J Bone Joint Surg Am 88:974–979, 2006.
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org
Demographics and Functional Outcome of Toe Fractures Sabine T. Van Vliet-Koppert, MD 1, Hamit Cakir, MD 2, Esther M.M. Van Lieshout, PhD 3, Mark R. De Vries, MD, PhD 4, Maarten Van Der Elst, MD, PhD 4, Tim Schepers, MD, PhD 4, 5 1
Orthopedics Resident, Department of General Surgery and Traumatology, Reinier de Graaf Groep, Delft, The Netherlands Surgery Resident, Department of General Surgery and Traumatology, Reinier de Graaf Groep, Delft, The Netherlands 3 Research Coordinator, Trauma Surgery, Department of Surgery-Traumatology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands 4 Trauma Surgeon, Department of General Surgery and Traumatology, Reinier de Graaf Groep, Delft, The Netherlands 5 Trauma Surgeon, Department of Surgery-Traumatology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands 2
a r t i c l e i n f o
a b s t r a c t
Level of Clinical Evidence: 2 Keywords: epidemiology foot fracture injury outcome phalanx toe
Toe fractures are common; however, there are few data on demographics and functional outcome. We studied outcomes in 339 consecutive patients with toe fractures treated between January 2006 and September 2008. Two hundred and sixty-four patients, aged 16 to 75, were mailed an outcome questionnaire, and overall subjective satisfaction with the outcome of treatment was measured using a visual analog scale (VAS). Most frequently affected were the first (38%) and fifth (30%) toes, and most (75.6%) of the fractures were caused by stubbing or crush injury. More than 95% of the fractures were displaced less than 2 mm, and all of the fractures were treated conservatively. The questionnaire was returned by 141 (53%) patients with a median follow-up of 27 months. Respondents were female in 57.4% of cases and had a median age of 45 years. The median AOFAS score was 100 (P25, P75 ¼ 93,100) points; the median VAS was 10 (P25, P75 ¼ 8, 10) points. Univariate regression analysis revealed no statistically significant associations between outcome and the particular toe or phalanx involved, number of fractured toes, fracture type and location, articular involvement, gender, age, body mass index, smoking habits, and the presence of diabetes mellitus. Satisfaction VAS was dependent on age (P ¼ .047) and gender (P ¼ .049) in the multivariate analysis. The AOFAS midfoot score was not influenced by any of the covariates. This is the first epidemiological investigation using 2 outcome-scoring systems to determine function and satisfaction following treatment of toe fractures. Ó 2011 by the American College of Foot and Ankle Surgeons. All rights reserved.
Digital fractures are among the most common fractures of the foot, with an incidence ranging from 14.0 to 39.6 patients per 10,000 persons per year (1–4). Their prevalence varies from 3.0% of fractures in children to 3.6% of all fractures in adults (1–4). However, previous studies lack data on demographics and digital fracture patterns. Almost all toe fractures, particularly the lesser toes, can be treated conservatively with expectation of a satisfactory outcome (3, 5–7). To date, the functional outcome and patient satisfaction after a toe fracture have not been investigated. The primary aim of this investigation was to evaluate the demographics of toe fractures in a Level 2 trauma center, providing care for a patient population of more than 300,000. The secondary aim was to determine the functional outcome and patient satisfaction after treatment for a digital fracture of the foot as determined using validated outcome-scoring systems. Financial Disclosure: This study was financially supported by the WAC (Wetenschappelijke Activiteiten Commissie) of the Reinier de Graaf Groep Delft. Conflict of Interest: None reported. Address correspondence to: Tim Schepers, MD, PhD, Trauma Surgeon, Department of Surgery-Traumatology, Erasmus Medical Center, University Medical Center Rotterdam, Room H-822k, PO Box 2040, 3000 CA Rotterdam, The Netherlands. E-mail address: [email protected] (T. Schepers).
Patients and Methods Demographics All consecutive patients with a toe fracture caused by an isolated trauma to the foot, between January 1, 2006, and June 31, 2008, were extracted from the Emergency Department registries, following approval of the local medical ethics board. The initial radiographs performed at the Emergency Department were reevaluated by 2 observers (T.S., S.T.V.). Patient characteristics (eg, age, body mass index [BMI], gender, diabetes, smoking habits, and side of injury) were collected. Data on the fracture characteristics (ie, which toe and phalanx were involved, the number of involved toes, joint involvement, type of fracture [transverse, oblique/spiral, comminution, or avulsion], the fracture level [distal, shaft, proximal], the amount of displacement [zero, < 2 mm, 2 to 5 mm, and > 5 mm], and the trauma mechanism (supination, fall from height, crush, stub, or stress fracture) were abstracted from the medical records. Treatment for all patients was carried out according to hospital protocol. Patients with a fracture of the great toe were treated with a cast for 3 weeks initially. Fractures of 1 or more of the lesser toes were treated with splinting to the adjacent intact toe, and patients were advised to wear a rigid-sole shoe. Functional Outcome Questionnaire A postal survey was developed according to existing guidelines to optimize response rates (8). The recommendations of the American Association for Public Opinion Research (AAPOR) were carefully followed (9). All patients between 16 and 75 years old were sent
1067-2516/$ - see front matter Ó 2011 by the American College of Foot and Ankle Surgeons. All rights reserved. doi:10.1053/j.jfas.2011.02.003
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a questionnaire containing the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and a single-question 10-cm visual analog scale (VAS) pertaining to subjective patient satisfaction. As physical examination of the patients (range of motion of the toe joints) was not possible, the hallux and lesser metatarsophalangealinterphalangeal AOFAS scores could not be applied, as they rely heavily on the range of motion of the toes. The AOFAS midfoot score was introduced by Kitaoka et al in 1994 (10). It includes questions pertaining to pain, activity and functional limitations, footwear, walking distance, difficulties with different terrains, gait, and alignment (whether or not plantigrade). The 7 questions relate to 3 components: pain (1 question; maximum 40 points), function (5 questions; maximum 45 points), and alignment (1 question; maximum 15 points), leading to a total possible score of 100 points. The question related to alignment was completed by a physician, based on information abstracted from the patient records and radiographs; the patient answered all of the other questions. The VAS was used to measure overall patient satisfaction with the outcome (range 0 to 10 cm) (11). In addition, patients were asked about their ability to run, walk on their toes, and walk barefoot. After 3 weeks, the nonrespondents were sent a reminder letter, including another copy of the questionnaire and a return envelope. Statistical Analysis The statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 16.0 (SPSS, Chicago, IL). The Kolmogorov-Smirnov test was used to test for normality of the numeric data. Levene’s test was applied to assess homogeneity of variance between data. Because most numeric variables did not show normal distribution or equal variance, all items were regarded as nonparametric for the statistical analysis. MannWhitney U tests were performed to assess statistical differences in AOFAS and VAS scores between subgroups (eg, males versus females, smoking versus nonsmoking, absence versus presence of diabetes, first digit fractures, and multiple fractures). Numeric data are expressed as medians with the 25th to 75th percentile (P25 to P75) range; categorical data are shown as counts and percentages. Logistic regression models were subsequently developed to correct for gender, age, diabetes, smoking habits, BMI, fracture type, and fracture dislocation (displacement). A P value < .05 was considered statistically significant.
Results Demographics In the 30-month study period, 339 patients with 368 digital and 370 phalangeal fractures of the foot were identified. Two patients had 2 concurrent phalangeal fractures in the same digit. There were 172 (50.7%) males and 167 (49.3%) females in the cohort. The median age of the group was 35.2 (19.3 to 53.5) years; the male patients had a median age of 26.0 (15.0 to 44.7) years, and female patients had a median age of 43.3 (26.1 to 58.6) years. Patients 5 years or younger accounted for 2.7% of all patients, and those 12 years or younger represented 15% of the study population. The right side was involved in 177 (51.9%) patients and the left side in 164 (48.1%). In 2 cases, a bilateral digital injury was encountered, but with an interval of several weeks between the injuries. With regard to the distribution of fractured digits, the first toe accounted for 141 (38.1%) fractures, the second toe accounted for 40 (10.8%), the third toe accounted for 26 (7%), the fourth toe accounted for 50 (13.5%), and the fifth toe accounted for 113 (30.5%) (Figure 1). Multiple digital fractures were observed in 5.9% of the toes (2 toes [4.4%], 3 toes [0.9%], and 4 toes [0.6%]). With regard to the mechanism of trauma, stubbing was most prevalent and accounted for 51.6% of the fractures, whereas 24% were a result of crush injury, and 11.2% were a result of supination (ankle and foot inversion) injury. With regard to the degree of fracture displacement, 97% of the fractures were either non- or minimally (< 2 mm) displaced. With regard to the orientation of the fracture, 33% of the fractures were transverse, 41% were spiral or oblique, 13% were comminuted, and 13% were avulsion injuries. Involvement of the phalangeal joint surface was noted in 122 (33%) of the phalangeal fractures, and they occurred predominately at the base of the phalanx. All of the digital fractures were treated conservatively. Functional Outcome Questionnaire A total of 141 (53%) of 264 patients between 16 and 75 years of age returned the questionnaire with a median follow-up of 27.3 (21.2 to
Fig. 1. Distribution of toe (n ¼ 368) and phalangeal (n ¼ 370) fractures according to their location.
39.0) months. Respondents were female in 57.4% of cases, and the median age for the respondents was 44.7 (30.8 to 58.3) years. The median BMI for the respondents was 23.9 (21.6 to 26.0). In 46.8% of the patients the left side was affected. A total of 7.4% of the patients had diabetes and 25.7% were smokers. In the respondent group, 66 (47%) patients were treated by splinting the fractured toe to an adjacent toe, and 44 (31%) were treated with a cast. Three (2%) patients were treated without the use of a splint or a cast. With regard to self-reported activity level, 84.4% of the responders reported being able to run, 75.2% to walk on their toes, and 82.3% to walk barefoot. Twenty-five (18%) patients failed to answer the questions about activity level. The median AOFAS midfoot score was 100 (93 to 100) points, with an AOFAS functional subscore of 45 (45 to 45). The median satisfaction VAS was 10 (8 to 10) points. Respondents were comparable to nonrespondents, except for age (44.7 versus 36.9 years, respectively).
Table 1 Functional outcome scores per subgroup (n ¼ 141 patients)* Patient or Fracture Characteristic Smoking Yes No Diabetes Yes No Gender Male Female Hallux fracture Yes No Number of fractures Single Multiple Fracture location Extra-articular Intra-articular Displacement 2 mm > 2 mm
VAS
AOFAS Functional Score
AOFAS Total Score
9 (8, 10) 10 (8, 10)
45 (45, 45) 45 (45, 45)
100 (90, 100) 100 (93, 100)
9 (8, 10) 10 (8, 10)
45 (43, 45) 45 (45, 45)
93 (89, 100) 100 (93, 100)
10 (8, 10) 10 (8, 10)
45 (45, 45) 45 (45, 45)
100 (93, 100) 100 (93, 100)
10 (8, 10) 10 (8, 10)
45 (44, 45) 45 (45, 45)
100 (93, 100) 100 (93, 100)
10 (8, 10) 9 (8, 10)
45 (45, 45) 45 (45, 45)
100 (93, 100) 100 (80, 100)
10 (8, 10) 9 (8, 10)
45 (45, 45) 45 (45, 45)
100 (93, 100) 100 (93, 100)
10 (8, 10) 10 (7, 10)
45 (45, 45) 44 (39, 45)
100 (93, 100) 93 (78, 96)
Abbreviations: AOFAS, American Orthopaedic Foot and Ankle Society; VAS, visual analog scale (satisfaction). * Data are shown as medians with the P25 to P75 between parentheses. Data analyzed using the Mann-Whitney U test.
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Statistical Analysis As for the inferential statistical analyses, no differences in outcome were identified with regard to which toe or phalangeal bone was affected, the number of fractured toes, fracture type and location, joint involvement, gender, age, BMI, smoking habits, or the presence of diabetes mellitus (Table 1). A statistically significant correlation was found between the AOFAS overall score, the AOFAS functional subscore, and satisfaction VAS (Table 2). These outcome scores showed no significant correlation with age or BMI (P > .05). The univariate regression analyses revealed a weak association between increased dislocation (fracture displacement) and lower AOFAS scores, although this was not statistically significant (P ¼ .058). In the multivariable analysis, the VAS was dependent on age (P ¼ .047) and gender (P ¼ .049). The AOFAS midfoot score was not statistically significantly influenced by any of the parameters in the multivariable analysis.
Discussion The current study of 339 patients with 368 digital and 370 phalangeal fractures provides insight into one of the most common fractures of the foot. Males and females were equally represented in the current study, as opposed to previous studies in which a male predominance of 62% to 66% was reported (3–11). The study by Rennie et al (4), on pediatric fracture epidemiology, showed a similar age distribution as the current investigation. No comparison could be made with distribution data in the literature for adults (1–3). The number of great toe fractures in this study (38%) is higher than previously reported (17%–24%) (2). This difference might be because of the inclusion of pediatric patients, in whom a higher incidence of first digital fractures was seen (41.9% in patients younger than 16 years). The median age of 35.2 years was similar to the age reported by Court-Brown and Caesar (1), who reported an average age of 35.3 years with exclusion of patients younger than 12 years. Rennie et al (4), looking at patients younger than 16 years, found an average age of 10.9 years for patients presenting with toe fractures. The secondary aim of this study was to evaluate functional outcome scores after the conservative treatment of toe fractures. Patients were sent a postal questionnaire so as to obtain the highest possible response rate. Hence, physical examination of the patients for range of motion of the toe joints was not possible. Therefore, we applied the AOFAS midfoot scale in the current study. The outcome scores in this population were excellent with a median of 100 (93–100) points (AOFAS) and 10 (8–10) points satisfaction (VAS). Despite the response rate of 53%, we can conclude that patient satisfaction after conservative treatment of toe fractures is high. We were not able to find any studies in the literature using outcome scores in toe fractures, and comparisons with historical controls were therefore not possible.
Table 2 Correlation between outcome scores, age, and BMI (n ¼ 141 patients) Patient or Fracture Characteristic
VAS
AOFAS Functional Score
AOFAS Total Score
VAS AOFAS functional score AOFAS total score Age BMI
NA 0.406* 0.530* 0.112 0.112
0.406* NA 0.668* 0.041 0.160
0.530* 0.668* NA 0.039 0.115
Spearman Rank Correlation coefficients per Spearman’s rank correlation test. Abbreviations: AOFAS, American Orthopaedic Foot and Ankle Society; BMI, body mass index; NA, not applicable; VAS, visual analog score (satisfaction). * P < .001.
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Because of the overall excellent scores for both the AOFAS midfoot score and the VAS, few predictors of outcome could be identified by the statistical analysis. However, our statistical analysis revealed a tendency toward the association of lower AOFAS scores with more displaced fractures in the univariate analysis, although this association was not statistically significant. Furthermore, there was no significant difference in outcome based on type and location of the fracture. In their review on the management of toe fractures, Hatch and Hacking (6) confirmed that most toe fractures treated conservatively led to an excellent functional outcome; however, they did not report an outcome score. In our fully adjusted multivariate analysis, lower satisfaction (VAS) with the overall outcome was associated with younger female patients, and this finding was consistent with earlier findings that female gender is a predictor of a less favorable outcome in ankle fractures (12). These results may be because of a patient population with high expectations related to the desire to wear fashionable shoe gear. We recognize a number of methodological limitations that could have influenced the validity of our results. Because physical examination of the patients, in particular assessment of digital range of motion, was not performed, we were not able to use the AOFAS hallux and lesser metatarsophalangeal-interphalangeal scoring scale. Despite this shortcoming, however, we believe that the scoring scale that we used conveyed face validity and, for this reason, was found to be useful for our purposes. We also understand that potential biases could be associated with data input into the medical record system, and thus ascertainment of eligible cases and the study variables of interest could have been affected by this. By the same token, use of the postal system conveys certain known selection biases, and this could have influenced the rate of participation with regard to our questionnaire. Furthermore, the patient population used in this study did not include those treated by a general practitioner or those who did not seek any medical attention at all; therefore, the incidence of toe fractures reported herein could be an underestimation. In fact, previous studies reported an incidence of 14 to 40 per 10,000 patients (1, 2). This study is the first epidemiological exploration of functional outcomes following toe fractures, and showed that more than 95% of such fractures are either non- or minimally displaced. Three-quarters of the fractures were transverse, oblique, or spiral, and in more than 75% of the cases the mechanism of injury was stubbing of the digit or a crush injury. An excellent outcome was obtained with conservative treatment, as measured by the AOFAS midfoot score and 10-cm satisfaction VAS after a median of 27 months of follow-up. Based on our findings in this study, as well as our understanding of the foot surgical literature, conservative treatment of toe fractures is generally associated with excellent outcome scores and high patient satisfaction with the results of treatment. Young female patients reported slightly less favorable outcomes, and a there was a tendency for a less favorable outcome in association with increased displacement at the fracture site. The distribution, patient, and fracture characteristics provided by this study may aid in the planning of future clinical trials concerning different treatment modalities for this common form of pedal trauma.
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