Page 32 - ISAKOS 2019 Newsletter Volume 1

CURRENT CONCEPTS
Stress Fractures in Footballers
Physical Examination
Physical examination usually reveals tenderness on palpation or percussion of the involved bone. Swelling, erythema, and warmth also may be present.
Imaging
Radiographs are the first-line imaging modality and have high specificity, although stress fractures can be missed initially. The earliest sign of a stress fracture on radiographs is localized periosteal thickening. In cases in which radiographs are negative and the index of suspicion of stress fracture is high, additional imaging studies should be considered. Magnetic resonance imaging (MRI) and 3-phase bone scintigraphy (bone scanning) have high sensitivity; however, MRI is preferred over bone scanning because of its higher specificity (Table II).
Table II Generic MRI Grading System for Stress Fractures
Treatment
Conservative Treatment
The treatment of stress fractures depends on the zone of the fracture but in most cases is conservative and should include decreased physical activity and training load, avoidance of pain-related activities, and weight-bearing restriction or immobilization. Pain control with oral analgesic medications, cold therapy, proper rehabilitation, and a personalized conditioning alternative physical program (minimal impact aerobic activities to maintain flexibility and strength) are recommended. NSAIDs should be avoided because of their negative effect on bone-healing.
Surgical Treatment
In patients with “high-risk” stress fractures or displaced fractures, especially athletes, early surgical fixation is preferred because of the high rates of treatment failure, extended healing time, the risk of nonunion, and the possibility of refracture8-10.
Strategies for operative intervention include intramedullary screw fixation, bone-grafting, and tension band wiring. In addition, some authors have advocated adding bone marrow aspirate concentrate (BMAC) to improve the biological environment and healing potential of the fracture site. Mallee et al.4, in a recent systematic review, found that surgical management was associated with proven benefits in terms of the times and rates of return to sport. Conservative management, however, remains a realistic option for the low- level athlete. The rate of refractures after surgical treatment of fifth metatarsal stress fractures has been reported to be as high as 10% to 30% in some series. The risk of refracture has been found to be associated with increased body weight, protrusion of the fifth metatarsal head, and Torg grade-2 and 3 fractures (Table III).
Table III Torg Classification of Fifth Metatarsal Stress Fracture
Low grade Grade 2 Grade 3
Grade
Findings
STIR and T2 signal change
STIR, T1, and T2 signal change
No fracture line present
Grade 1
High grade
Grade 4
STIR, T1, and T2 signal change
Fracture line present
*STIR = short-T1 inversion recovery.
“High-Risk” and “Low-Risk” Sites
Ekstrand and Torstveit3, in a study of 2,379 elite male football players, reported a total of 51 stress fractures, all of which occurred in the lower extremities; the most common site was the fifth metatarsal (78%), followed by the tibia (12%) and the pelvis (6%). Twenty-nine percent of the stress fractures were reinjuries.
It is very important to be aware of “high-risk” stress fracture sites, including the fifth metatarsal (specifically zone 2, the metaphyseal-diaphyseal junction), talar neck, femoral neck, patella, anterior tibial diaphysis, medial malleolus, navicular, sesamoids of the hallux, and necks of the second to fourth metatarsals. Stress fractures in these sites are prone to complications such as displacement, delayed union, and nonunion, and the need for prolonged treatment.
“Low-risk” stress fracture sites include the posteromedial tibial shaft, metatarsal shaft, distal fibula, medial femoral neck, femoral shaft, and calcaneus; fractures in those sites often heal with proper diagnosis and treatment.
Grade 1
• Acute fracture • No periosteal
reaction
Grade 2
Grade 3
• Non-union
• Periosteal
reaction
30 ISAKOS NEWSLETTER 2019: VOLUME I
STIR* signal change
• Delayed union
• Periosteal
reaction
• Intramedullary sclerosis
• Widened fracture line
• No• intramedullary narrowing
sclerosis
Fifth Metatarsal Stress Fracture
• Widened fracture line
Intramedullary
For primary stress fractures of the fifth metatarsal in high- level athletes who participate in high-intensity sports involving repetitive loading, our preferred method is intramedullary fixation with use of a partially threaded cancellous cannulated screw.