To compare the clinical, radiologic, and functional outcomes between shockwave and operative treatments for proximal fifth metatarsal stress fractures in soccer players in a pilot study.
Between 2017 and 2019, 18 soccer players with fifth metatarsal stress fractures attended at Mutualidad de Futbolistas Españoles-Delegación Catalana were included. Patients were randomly assigned into 2 groups receiving either surgery with an intramedullary screw (group 1) or high-energy focused extracorporeal shockwave treatment (group 2 performed once a week for 3 weeks using 2000 impulses at an energy flux density of 0.21 mJ/mm2 and 4 Hz frequency). Clinical (pain), radiologic (bone healing), and functional (Tegner Activity Scale and American Orthopaedic Foot & Ankle Society [AOFAS] ankle-hindfoot scales) outcomes before and after receiving the treatment were compared between both groups. In addition, ability and time to return to play was also compared between groups.
No patients were lost to follow-up. There were no statistically significant differences at last follow-up between surgery and extracorporeal shockwave treatment for bone healing, pain relief, AOFAS ankle-hindfoot score, Tegner score, and time return to play. No complications were reported in either of the 2 groups.
In this pilot study, extracorporeal shockwave treatment and operative treatment were found to be equally effective at reducing pain, achieving bone healing, and allowing the soccer players to return to play after proximal fifth metatarsal stress fractures. This study suggests that ESWT may be a good option for the management of proximal fifth metatarsal stress fractures in soccer players. If this approach proves successful in larger trials, the shockwave approach might help avoid known complications of the surgical treatment like wound problems, nerve injury, and hardware intolerance. Further investigations with larger sample size should be conducted in order to confirm the present conclusions.
Level II, therapeutic, pilot randomized controlled trial.

We examined outcomes following metatarsophalangeal joint cheilectomy with decompression osteotomy to evaluate the efficacy of this technique for treatment of hallux limitus/rigidus. At a minimum follow-up of 5 years, we identified 94 patients who fit the inclusion criteria. Chart review was performed to obtain range of motion (ROM) of the first metatarsophalangeal joint (MTPJ) preoperatively and at 6 weeks, 6 months, and 5 years postoperatively. Additionally, time to traditional shoe gear return, need for revision arthrodesis, radiographic findings, and postoperative visual analog scale (VAS) pain scores were reviewed. Statistical analysis was conducted by 1-way analysis of variance with post-hoc analysis and independent sample t-test. At an average follow-up of 6.3 ± 0.9 years, 42.3% (33/78) of females and 25.0% (4/16) of males reported limited ROM of the first MTPJ with 5 patients requiring first MTPJ arthrodesis. MTPJ ROM improved on average from 11.0° to 36.3° by 5-year minimum follow-up after surgery (p < .001). Analysis of variance revealed a significant difference of the preoperative ROM when compared to all postoperative time points (F[3,368] = 69.4, p < .001). Mean postoperative VAS pain scores after decompression osteotomy of the 5 patients who required MTPJ fusion were higher when compared to the rest of the patient cohort at final follow-up (7.4 ± 0.6 vs 1.5 ± 1.3; p < .001). Cheilectomy with decompression osteotomy for treatment of hallux limitus/rigidus leads to satisfactory long-term outcomes.

BACKGROUND: Although metatarsal fractures are common, the significance of previous epidemiologic studies is limited to specific fracture entities, subpopulations, or heterogeneous fracture aetiologies. The aim of the study was to assess the epidemiology of isolated metatarsal fractures in an adult population at a level-1 trauma centre.
METHODS: Radiological and clinical databases were searched for a five-year period. Eligible were all patients with acute isolated metatarsal fractures over the age of 18 years with radiographs in two planes available. Stress fractures, injuries affecting Lisfranc joint stability, and concomitant injuries to other regions than the metatarsals were excluded. Data collection included general demographics, mechanism of injury, season of the trauma and fracture details.
RESULTS: Out of 3259 patients, 642 patients met the inclusion criteria and were included for the analysis. The patients\' mean age was 44.5 ± 18.9 years, 50.6% were female. 83.3% suffered an isolated, 16.7% multiple metatarsal fractures. Single metatarsal fractures occurred predominantly at the fifth metatarsal bone (81.3%), their frequency decreased with increasing age, with a seasonal peak during the summer. Patients suffering multiple metatarsal fractures were significantly older (51.6 ± 21.2 vs. 43.0 ± 18.1 years; p < 0.001) and the injury resulted significantly more often from a high-energy trauma (6.7% vs. 23.4%; p < 0.001). Multiple metatarsal fractures occurred evenly throughout all metatarsals but revealed a focus on female population with no seasonal differences.
CONCLUSIONS: Single metatarsal fractures predominantly occurred at the fifth metatarsal bone and showed a seasonal, gender and age dependency. Multiple metatarsal fractures were homogeneously distributed between the different metatarsals with distinct age-dependent gender differences.
METHODS: Level III.

Various fixation methods are available for the operative treatment of metatarsal shaft fractures: Kirschner wire, Titanium elastic nail, plate, or an intramedullary bone stabilization system within a balloon catheter. The aim of this study was to compare the stability of these techniques.
72 metatarsals II to V from fresh frozen human cadaver feet were used. A shaft fracture was performed and fixed with a 1.6-mm Kirschner wire, a 1.5-mm Titanium elastic nail, a locking 6-hole-plate, or an intramedullary bone stabilization system. In a cantilever configuration, the head of the metatarsals was loaded statically (2 mm/min until failure; all groups) or cyclically (0 to 20 N for 1000 cycles with 10 mm/s, after 1000 cycles 2 mm/min until failure; plate and bone stabilization system).
The mean failure strength for static loading was 17 N for Kirschner wire, 13 N for Titanium elastic nail, 73 N for plate and 34 N for the bone stabilization system (P < .01). For cyclic loading, the mean cycle of failure was 1000 for plate and 961 for the bone stabilization system (P = .76). The mean failure strength after cyclic loading was 73 N for plate and 48 N for the bone stabilization system (P = .03).
Stability differs depending on the fixation method, with a plate showing the greatest stability and Kirschner wire or Titanium elastic nail the least. The stability of the bone stabilization system for fixing metatarsal shaft fractures is intermediate.

The aim of the present paper is to determine the sex of the individual using three-dimensional geometric and inertial analyses of metatarsal bones. Metatarsals of 60 adult Chinese subjects of both sexes were scanned using Aquilion One 320 Slice CT Scanner. The three-dimensional models of the metatarsals were reconstructed, and thereafter, a novel software using the center of mass set as the origin and the three principal axes of inertia was employed for model alignment. Eight geometric and inertial variables were assessed: the bone length, bone width, bone height, surface-area-to-volume ratio, bone density, and principal moments of inertia around the x, y, and z axes. Furthermore, the discriminant functions were established using stepwise discriminant function analysis. A cross-validation procedure was performed to evaluate the discriminant accuracy of functions. The results indicated that inertial variables exhibit significant sexual dimorphism, especially principal moments of inertia around the z axis. The highest dimorphic values were found in the surface-area-to-volume ratio, principal moments of inertia around the z axis, and bone height. The accuracy rate of the discriminant functions for sex determination ranged from 88.3% to 98.3% (88.3%-98.3% cross-validated). The highest accuracy of function was established based on the third metatarsal bone. This study showed for the first time that the principal moment of inertia of the human bone may be successfully implemented for sex estimation. In conclusion, the sex of the individual can be accurately estimated using a combination of geometric and inertial variables of the metatarsal bones. The accuracy should be further confirmed in a larger sample size and be tested or independently developed for distinct population/age groups before the functions are widely applied in unidentified skeletons in forensic and bioarcheological contexts.

In this multicenter study, we evaluated commonly used methods of fixation and 2 methods of joint preparation for first metatarsophalangeal joint fusion, in terms of radiological union and revision rates. Included were 409 consecutive fusions in 385 patients. The overall union rate was 91.4% (34/409). About 29.4% (10/34) of our nonunions were symptomatic. Preoperative hallux valgus showed a statistically significant relation to nonunion (odds ratio [OR] = 9.33, p = .017). Other potential contributing factors like gender (OR 1.9, p = .44), diabetes (OR = 0, p = .99), steroid use (OR = 2.07, p = .44), inflammatory arthritis (OR = 0, p = .99), and smoking (OR = 2.69, p = .34) did not attain statistical significance. Further, the methods of fixation like solid screws (OR = 0, p = .99), plate (OR = 3.6, p = .187), or cannulated screws (OR = 0.09, p = .06) showed no correlation with incidence of nonunion. We compared 2 techniques of joint preparation and found no significant difference in union rates (chi-square = 1.0426, p = .30). Our crude comparison of costs showed the average saving to the trust per year could be 33,442.50£ by choosing screws over plates. To conclude, only hallux valgus had a statistically significant relation to nonunion. All other variables had no significant impact on the union. Solid screw seems to be economically the most viable option and a valid alternative.

Predicting sex is an important problem in forensic medicine. The femur, patella, mandible and calcaneus bones are frequently used in predicting sex. In our study, we aimed to use the artificial neural network (ANN) technique to predict sex by measuring the values of the phalanges of the first and fifth toes and the first and fifth metatarsal bones.
All bone measurements were conducted on the direct X-ray images of 176 males and 178 females in the age range of 24-60 years. The multilayer perceptron classifier (MLPC) input layer included parameters on the bone length measurements of phalanx proximalis I, phalanx distalis I, metatarsal I, phalanx proximalis V, phalanx medialis V, phalanx distalis V and metatarsal V. The output layer contained two neurons to define the male and female sexes. The present study used an MLPC model that had two hidden layers, and the first and second hidden layers contained 14 and 7 nodes, respectively.
The model had an overall accuracy (Acc) of 0.95, specificity (Spe) of 0.97, sensitivity (Sen) of 0.95 and Matthews correlation coefficient (Mcc) of 0.92. While the sex prediction success of our proposed model was higher in women, the results were more specific in men and more sensitive in women (AccMale = 0.93, AccFemale = 0.98, SenMale = 0.93, SpeMale = 0.98, SenFemale = 0.98 and SpeFemale = 0.93).
This study demonstrated that the ANN model for length measurements on small bones is a highly effective instrument for sex prediction.

Background Pathologic conditions of the sesamoids can be a source of disabling pain for patients, particularly during toe-off. Some underlying causes include osteonecrosis, inflammation, arthritis, and fracture. Nonoperative treatment is the initial standard of care, and has demonstrated satisfactory outcomes overall; however, operative management may be indicated in cases of pain refractory to conservative management. Sesamoidectomy is an uncommon procedure with risk of potential complications, but may be warranted in select cases of failed nonoperative treatment. Methods A retrospective chart review was conducted at one institution from 2009 to 2018. Twelve patients diagnosed with fibular sesamoiditis were treated with sesamoidectomy. Baseline patient demographics as well as postoperative outcomes were recorded. Results All 12 patients underwent fibular sesamoidectomy using the plantar approach following which their symptom (pain) resolved. Average follow-up for this cohort was 35 months. Of the sample, two patients experienced transient neuritis, one patient developed a superficial infection, and one had painful postoperative scarring. Hallux varus deformity was not observed in any patients. Conclusion Fibular sesamoidectomy may be a safe, viable procedure for patients with sesamoiditis who fail conservative measures.

BACKGROUND: While posterior tibial tendon dysfunction (PTTD) commonly presents with flat feet and has been thought to be associated with first ray mobility, many flat-footed individuals are asymptomatic and do not experience any symptoms of PTTD. Thus, there is a need to control for foot type when studying factors related to PTTD. This study aimed to clarify if first ray mobility differed between flat-footed individuals with and without symptoms of PTTD. It was hypothesized that PTTD patients would display higher mobility of the first ray than asymptomatic flat-footed controls.
METHODS: Given that PTTD patients were often flat-footed, asymptomatic flat-footed individuals were chosen as controls to remove flatfoot as a potential confounding factor. We recruited 32 flat-footed subjects, of which 16 exhibiting PTTD symptoms and 16 asymptomatic controls matched for age, sex and body mass index. First ray mobility was assessed using subjective classification (\"stiff\", \"normal\" or \"hypermobile\") and maximum dorsal displacement using a ruler indicator. Mann-Whitney U was used to test for between-groups differences.
RESULTS: Subjective classification was similar between PTTD and control groups (both groups: 38% \"normal\" joint mobility). No significant differences were found between PTTD patients and asymptomatic controls in first ray displacement [median (IQR), PTTD: 6.00 (1.75) mm; control: 6.00 (1.00) mm; P=.31].
CONCLUSIONS: First ray mobility was not associated with PTTD in flat-footed persons. When evaluating symptoms of PTTD, clinicians should pay attention to factors other than first ray mobility.

BACKGROUND: Operative correction of symptomatic bunionette by means of minimally invasive (MI) osteotomies of the 5th metatarsal (M5) has gained popularity. This study aims to investigate the safe zones of commonly used techniques and the risk of injury to neurological structures.
METHODS: Ten human fresh frozen cadaveric feet were dissected and branches of the sural nerve were identified. A frontal section of the feet was performed at the site of the skin incision described for M5 MI osteotomies (corresponding to distal and mid diaphyseal osteotomies). The location of the lateral dorsal cutaneous nerve (LDCN) of the sural nerve or its branches was documented using a goniometer and o\'clock references placed on the frontal section of the M5.
RESULTS: The LDCN showed variations in the distribution of its branches, forming the dorsolateral branch - a single terminal branch for the 5th toe - in 6/10 cases or two terminal branches - the dorsolateral and dorsomedial - in 4/10. At the point of osteotomies, the dorsolateral branch was identified at a mean of 22.7° from the extensor tendon around the M5 circumference and in all cases between 12 and 2 o\'clock in a right foot or 10 o\'clock to 12 o\'clock in a left.
CONCLUSIONS: The studied M5 osteotomies can place the dorsolateral branch of the fifth toe at risk and safe zones lie between 10 o\'clock to 2 o\'clock in any foot laterality. If these landmarks are considered, the risk of nerve damage is minimized when performing MI osteotomies of the M5.