5th MT Spectrum of Fractures
Results
Anatomic distribution of fractures
A total of 2,459 5th metatarsal fractures in 2,453 patients presented to our institution. Among all 5th metatarsal fractures, 955 were Zone 1 metatarsal base fractures, representing the most common type of 5th metatarsal fracture (38.8%). Similar numbers of Zone 2 metatarsal base fractures and shaft fractures were treated (26.2% and 24.5% respectively). Zone 3 base fractures, or true Jones fractures, represented a relatively smaller proportion of the 5th metatarsal fractures seen with 6.9%. 3.3% of 5th metatarsal fractures were of the metatarsal neck, while isolated 5th metatarsal head fractures were relatively uncommon (0.2%).
| Characteristic | Overall, N = 2,4591 | Type of 5th Metatarsal Fracture | p-value2 | |||||
|---|---|---|---|---|---|---|---|---|
| Zone 1, N = 9551 | Zone 2, N = 6451 | Zone 3, N = 1701 | Shaft, N = 6021 | Neck, N = 821 | Head, N = 51 | |||
| Age (years) | 49.5 +/- 18.5 | 45.7 +/- 19.0 | 53.0 +/- 17.1 | 46.1 +/- 18.6 | 51.9 +/- 17.3 | 55.1 +/- 22.1 | 53.2 +/- 19.6 | <0.001 |
| Sex | 0.002 | |||||||
| Female | 1,763 (72.2%) | 647 (68.4%) | 480 (74.4%) | 112 (66.3%) | 456 (76.5%) | 65 (79.3%) | 3 (60.0%) | |
| Male | 680 (27.8%) | 299 (31.6%) | 165 (25.6%) | 57 (33.7%) | 140 (23.5%) | 17 (20.7%) | 2 (40.0%) | |
| BMI | 26.8 +/- 5.9 | 26.5 +/- 5.7 | 27.2 +/- 6.0 | 28.2 +/- 6.7 | 26.4 +/- 5.6 | 27.1 +/- 6.0 | 29.9 +/- 9.4 | 0.005 |
| Race | 0.029 | |||||||
| Asian | 148 (6.1%) | 60 (6.3%) | 42 (6.6%) | 15 (8.9%) | 26 (4.4%) | 5 (6.1%) | 0 (0.0%) | |
| Black | 158 (6.5%) | 61 (6.4%) | 37 (5.8%) | 18 (10.7%) | 40 (6.7%) | 2 (2.4%) | 0 (0.0%) | |
| Native American | 6 (0.2%) | 2 (0.2%) | 1 (0.2%) | 0 (0.0%) | 2 (0.3%) | 1 (1.2%) | 0 (0.0%) | |
| Other | 292 (12.0%) | 119 (12.6%) | 61 (9.5%) | 24 (14.2%) | 71 (11.9%) | 14 (17.1%) | 3 (60.0%) | |
| Pacific Islander | 2 (0.1%) | 0 (0.0%) | 1 (0.2%) | 1 (0.6%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | |
| Unknown | 262 (10.8%) | 109 (11.5%) | 70 (11.0%) | 19 (11.2%) | 55 (9.2%) | 9 (11.0%) | 0 (0.0%) | |
| White | 1,569 (64.4%) | 595 (62.9%) | 427 (66.8%) | 92 (54.4%) | 402 (67.4%) | 51 (62.2%) | 2 (40.0%) | |
| Smoking status | 0.013 | |||||||
| Daily | 203 (8.5%) | 79 (8.5%) | 52 (8.2%) | 15 (9.1%) | 53 (9.0%) | 4 (4.9%) | 0 (0.0%) | |
| Former | 459 (19.1%) | 152 (16.4%) | 142 (22.5%) | 26 (15.8%) | 114 (19.4%) | 21 (25.6%) | 4 (80.0%) | |
| Never | 1,739 (72.4%) | 698 (75.1%) | 438 (69.3%) | 124 (75.2%) | 421 (71.6%) | 57 (69.5%) | 1 (20.0%) | |
| Charlson Comorbidity Index | 0.4 +/- 1.0 | 0.3 +/- 0.9 | 0.5 +/- 1.1 | 0.4 +/- 0.9 | 0.4 +/- 1.1 | 0.9 +/- 2.1 | 1.2 +/- 1.3 | <0.001 |
| 1 Mean +/- SD; n (%) | ||||||||
| 2 Kruskal-Wallis rank sum test; Fisher’s Exact Test for Count Data with simulated p-value (based on 2000 replicates) | ||||||||
Among all patients presenting with 5th metatarsal fractures, the mean age was 49.5 +/- 18.5 years. The majority of patients were female (71.7%). Although there were statistically significant differences in baseline demographic characteristics between groups, the small differences are unlikely to be clinically relevant (Table 1).
1145 patients (46.6%) did not meet inclusion criteria because they did not continue to follow up until the point of clinical and radiographic healing or until 6 months from the time of injury. Furthermore, only 2 patients with isolated metatarsal head fractures met the minimum follow up time. Given the low sample size for this group, isolated head fractures were not included in the analysis. Therefore, a total of 1314 patients with 5th metatarsal fractures were included in the subsequent analysis. The mean age of the overall cohort was 49.6 +/- 18.0 years and the mean BMI was 26.7 +/- 5.9.
Among the included patients, 80 patients (6.1%) were initially treated nonoperatively and 1234 patients (93.9%) were treated operatively.
Overall treatment
| Characteristic | Overall1 | Type of 5th Metatarsal Fracture | p-value2 | ||||
|---|---|---|---|---|---|---|---|
| Zone 11 | Zone 21 | Zone 31 | Shaft1 | Neck1 | |||
| Nonoperative | |||||||
| Treated with splint/cast | 332 (27.3%) | 113 (24.9%) | 115 (34.1%) | 24 (31.6%) | 76 (24.8%) | 4 (8.9%) | <0.001 |
| Duration of splint/cast (weeks) | 1.9 +/- 3.4 | 2.3 +/- 5.3 | 1.7 +/- 2.0 | 1.5 +/- 1.8 | 1.6 +/- 1.8 | 2.0 +/- 1.5 | 0.944 |
| Treated with CAM boot | 954 (78.4%) | 360 (79.5%) | 270 (80.1%) | 64 (84.2%) | 229 (74.8%) | 31 (68.9%) | 0.130 |
| Duration of CAM boot (weeks) | 6.8 +/- 4.5 | 6.5 +/- 4.9 | 6.8 +/- 4.8 | 8.2 +/- 4.4 | 6.9 +/- 3.6 | 5.9 +/- 3.0 | 0.002 |
| Treated with hard sole shoe | 431 (35.4%) | 142 (31.3%) | 126 (37.4%) | 22 (28.9%) | 123 (40.2%) | 18 (40.0%) | 0.069 |
| Duration of hard sole shoe (weeks) | 4.8 +/- 4.2 | 4.9 +/- 5.3 | 4.6 +/- 3.4 | 4.1 +/- 4.1 | 5.0 +/- 3.5 | 5.2 +/- 4.2 | 0.515 |
| Total duration of immobilization (weeks) | 7.6 +/- 5.4 | 7.3 +/- 6.7 | 7.8 +/- 4.9 | 8.6 +/- 4.5 | 7.6 +/- 3.7 | 6.7 +/- 3.2 | 0.001 |
| Operative | |||||||
| Type of Fixation Construct | <0.001 | ||||||
| IM Screw | 53 (54.6%) | 6 (42.9%) | 18 (85.7%) | 24 (96.0%) | 4 (11.1%) | 1 (100.0%) | |
| K-wires | 9 (9.3%) | 2 (14.3%) | 0 (0.0%) | 0 (0.0%) | 7 (19.4%) | 0 (0.0%) | |
| ORIF | 35 (36.1%) | 6 (42.9%) | 3 (14.3%) | 1 (4.0%) | 25 (69.4%) | 0 (0.0%) | |
| 1 n (%); Mean +/- SD | |||||||
| 2 Pearson’s Chi-squared test; Kruskal-Wallis rank sum test | |||||||
Patients treated nonoperatively
Overall, patients treated nonoperatively were managed with some form of foot immobilization or support (cast, splint, CAM boot, or hard sole shoe) for an average of 7.7 +/- 5.5 weeks (Table 2). Overall, 27.7% of patients were treated in a splint or cast. 78.7% of patients were treated in CAM boot or another type of walking boot at some point during their treatment. 21.6% of patients were first treated in a splint or cast and then transitioned to a CAM boot, while 57.1% of patients were immediately placed in a CAM boot upon presentation. Likewise, the weightbearing status at the initial office presentation varied considerably. 25.3% of patients were made non-weightbearing, while 7.1% were made partial weightbearing and 56.0% were allowed to immediately bear weight as tolerated.
| Characteristic | Overall, N = 1,2171 | Type of 5th Metatarsal Fracture | p-value2 | ||||
|---|---|---|---|---|---|---|---|
| Zone 1, N = 4531 | Zone 2, N = 3371 | Zone 3, N = 761 | Shaft, N = 3061 | Neck, N = 451 | |||
| Immediate Versus Delayed Weightbearing | <0.001 | ||||||
| Delayed | 390 (36.3%) | 106 (26.1%) | 118 (39.7%) | 49 (72.1%) | 109 (40.5%) | 8 (23.5%) | |
| Immediate | 684 (63.7%) | 300 (73.9%) | 179 (60.3%) | 19 (27.9%) | 160 (59.5%) | 26 (76.5%) | |
| 1 n (%) | |||||||
| 2 Pearson’s Chi-squared test | |||||||
Welch Two Sample t-test
data: duration_clinical_healed by immediate_wb
t = 2.108, df = 827.68, p-value = 0.03533
alternative hypothesis: true difference in means between group Delayed and group Immediate is not equal to 0
95 percent confidence interval:
0.08935874 2.50623103
sample estimates:
mean in group Delayed mean in group Immediate
10.877778 9.579983
Welch Two Sample t-test
data: duration_rad_healed by immediate_wb
t = -0.086515, df = 400.96, p-value = 0.9311
alternative hypothesis: true difference in means between group Delayed and group Immediate is not equal to 0
95 percent confidence interval:
-3.371049 3.086849
sample estimates:
mean in group Delayed mean in group Immediate
18.68429 18.82639 Overall, patients who were allowed to bear weight immediately demonstrated slightly faster time to clinical healing (9.6 +/- 8.8 weeks versus 10.9 +/- 10.9 weeks, p = 0.035). However, there was no difference in time to radiographic healing between those who were allowed to bear weight immediately and those who had a period of restricted weightbearing (18.8 +/- 18.6 weeks versus 18.7 +/- 14.4 weeks, p = 0.931).
| Characteristic | Overall, N = 1,2171 | Type of 5th Metatarsal Fracture | p-value2 | ||||
|---|---|---|---|---|---|---|---|
| Zone 1, N = 4531 | Zone 2, N = 3371 | Zone 3, N = 761 | Shaft, N = 3061 | Neck, N = 451 | |||
| Time to clinical healing (weeks) | 9.9 +/- 8.7 | 9.7 +/- 8.4 | 9.9 +/- 8.3 | 10.4 +/- 8.8 | 9.9 +/- 9.1 | 10.0 +/- 11.9 | 0.245 |
| Time to radiographic healing (weeks) | 17.9 +/- 15.6 | 18.7 +/- 22.2 | 18.7 +/- 12.0 | 19.7 +/- 11.2 | 16.1 +/- 8.5 | 13.0 +/- 5.3 | 0.088 |
| 1 Mean +/- SD | |||||||
| 2 Kruskal-Wallis rank sum test | |||||||
| Characteristic | Overall, N = 971 | Type of 5th Metatarsal Fracture | p-value2 | ||||
|---|---|---|---|---|---|---|---|
| Zone 1, N = 141 | Zone 2, N = 211 | Zone 3, N = 251 | Shaft, N = 361 | Neck, N = 11 | |||
| Time to clinical healing (weeks) | 12.3 +/- 15.6 | 9.8 +/- 8.3 | 15.5 +/- 15.0 | 11.0 +/- 25.1 | 11.9 +/- 9.6 | 23.1 +/- NA | 0.502 |
| Time to radiographic healing (weeks) | 21.5 +/- 19.7 | 20.4 +/- 11.0 | 18.5 +/- 16.6 | 21.3 +/- 25.9 | 24.6 +/- 18.3 | 23.1 +/- NA | 0.328 |
| 1 Mean +/- SD | |||||||
| 2 Kruskal-Wallis rank sum test | |||||||
