Intramedullary screw fixation in proximal fifth-metatarsal fractures in sports: clinical and biomechanical analysis.
OBJECTIVE
Intramedullary screw fixation (ISF) of proximal fifth-metatarsal fractures is known as first treatment option in young, sports active patients. No study analyzed functional and biomechanical outcome before. Hypothetically ISF leads to (1) a high bony union rate within 12 weeks, (2) normal hindfoot eversion strength, and (3) normal gait and plantar pressure distribution.


METHODS
Fourteen out of 22 patients were available for follow-up with an average follow-up of 42 months; clinical and radiological follow-up, and biomechanical evaluation by isometric muscular strength measurement (inversion, eversion strength) and dynamic pedobarography, comparing to the non-affected contralateral foot. Level of significance: 0.05.


RESULTS
Subjective result: Excellent or good result in 14 patients, none fair or poor. AOFAS midfoot score: 100 points in 13 patients and 87 points in 1 patient. The same sports activity level (0-4) was reached in 13 out of 14 patients. Radiologic examination: consolidation after 6 weeks in 9 patients and after 12 weeks in another 4 patients, one partial union. Average maximal eversion strength 59 N (ratio to the contralateral foot: 0.92, not significant). Dynamic pedobarography showed ratios of 0.99-1.01 to the contralateral side for ground reaction force, ground peak time, peak pressure and contact area (not significant).


CONCLUSIONS
A very-high patient-satisfaction, a fast bony healing and complete return to sports were documented. Muscular strength measurement and dynamic pedobarography showed complete functional rehabilitation. Therefore, ISF in proximal fifth-metatarsal fractures can be recommended as a secure procedure.
Leumann
André
A
Orthopaedic Department, Lower Extremity Orthopaedics, University Hospital of Basel, Spitalstr. 21, 4031 Basel, Switzerland. leumanna@uhbs.ch
Pagenstert
Geert
G
Fuhr
Peter
P
Hintermann
Beat
B
Valderrabano
Victor
V
D000293:Adolescent; D000328:Adult; D000368:Aged; D001265:Athletic Injuries / Q000000981:diagnostic imaging / Q000601:surgery*; D001863:Bone Screws; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation* / Q000379:methods; D017102:Fracture Healing / Q000502:physiology*; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D008682:Metatarsal Bones / Q000293:injuries* / Q000601:surgery; D008875:Middle Aged; D010147:Pain Measurement; D011859:Radiography; D020127:Recovery of Function; D018570:Risk Assessment; D016896:Treatment Outcome; D055815:Young Adult