Dan Preece DPM, PGY-1 Stress Fx Frequency /Distribution: -second metatarsal 52% -third metatarsal 35% -first metatarsal 8% -fourth and fifth metatarsals 5% **shorter first metatarsal of Morton's foot leads to a higher risk of second metatarsal stress fractures 1: Drez D Jr, Young J, Johnston R, Parker W: Metatarsal stress fractures. Am J Sports Med 8:123-125, 1980 2: Leabhart J: Stress fractures of the calcaneus. J Bone Joint Surg Am 41:1285-1290, 1959. Factors that can increase the risk of fractures (and stress fractures: -cavus foot conformation -long second metatarsal (e.g. Morton's foot) -metatarsus adductus -amenorrhea (hypoestrogenism) -hyperthyroidism -osteoporosis -medications -tobacco -alcohol abuse -nutritional problems -anemic disorders -training errors -poor footwear -improper athletic technique 3: Daffner R, Pavlov H: Stress fractures: Current concepts. Am J Radiol 159:245-252, 1992. Etiology and Description of Stress Fractures: - Microfractures Stress Reactions Cortical Fracture. - Stress fxs occur by cyclic loading that does not exceed the ultimate breaking limits of plastic deformation of bone. - One possible cause of stress fracture is muscle fatigue, which decreases shock-absorbing capacity of the extremity. - Repetitive force exerted by a muscle on bone 3: Daffner R, Pavlov H: Stress fractures: Current concepts. Am J Radiol 159:245-252, 1992. Biomechanical Causes of Metatarsal Stress Fxs: -Dorsal strains are significantly reduced by contraction of the plantar flexory musculature. - Fatigue of these muscles during strenuous or prolonged running may result in decreased dissipation of forces by the musculature and increased exposure of the metatarsals to stress. 4: Brukner P, Bradshaw C, Khan KM, et al. Stress fractures: a review of 180 cases. Clin J Sport Med. 1996;6(2):85–9. Clinical Presentation of Stress Fxs: - Metatarsal stress fxs have a much faster onset than similar injuries of the tibia and fibula. - The average time to presentation ranges from 2 to 6 weeks - Can occur with a single training event or military exercise. - Pain to direct palpation and through ROM, also pain, redness, swelling present. 5: Milgrom C, Finestone A, Sharkey N, et al: Metatarsal strains are sufficient to cause fracture during cyclic loading. Foot Ankle Int 23(3):230-235, 2002 Stress Fractures: - Imaging: -Plain films may not show changes for > 10 days. Changes may be evident in only 30% to 70% of cases. -Bone Scan: 99Tc bone scan is extremely sensitive, and uptake may be evident within 24 hours of injury (not specific however) . -MRI is highly sensitive and specific, particularly to identifying location. -CT is helpful to define a fx line and to determine whether the fx is complete or incomplete. 6: Matheson G, Clements D, McKenzie D, et al: Stress fractures in athletes: A study of 320 cases. Am J Sports Med 15:46-58, 1987. US in Dx of Stress Fractures: -Forty-one feet were analyzed with US and dedicated MRI from 37 patients. -MRI detected 13 fractures in 12 patients. -US was 83% sensitive, 76% specific. Positive predictive value 59%, and negative predictive value 92%. -In cases of normal radiographs, US is indicated in the diagnosis of metatarsal bone stress fractures, as it is a low cost, noninvasive, rapid, and easy technique with good sensitivity and specificity. 7: F Banal, F Etchepare, B Rouhier, C Rosenberg, V Foltz, S Rozenberg. Ultrasound ability in early diagnosis of stress fracture of metatarsal bone. Ann Rheum Dis. 2006 July; 65(7): 977–978. Stress Fx Treatment: -Activity restriction 4-8+ weeks. -Immobilization: depends on the duration of symptoms before the patient presenting for treatment. Longer duration: more severe injury. -Serial radiography used to document bony union. -Correct contributing factors : training techniques and footwear. -Return to activity is allowed when radiographic healing is noted and tenderness has completely resolved. -Recurrent stress fractures are uncommon in the absence of metabolic or endocrine disorders, and they rarely recur at the same site 8: K, Hahn S, Chung M, et al: A clinical study of stress fractures in sports activities. Orthopedics 15:1089-1095, 1991. Metatarsal Fx’s: -Frequency: 5th 3rd 2nd 1st 4th (different frequency than stress fx’s) -MCC: -Direct force: crushing, blunt trauma, penetrating wounds. -Indirect force: twisting injury (forepart of the foot is fixed as the pt turns) -Who? Most commonly: athletes, diabetics (worse with longer duration), men. -Diabetic neuropathy: has been associated with osteopenia in both hands and feet as well as metatarsal fxs. 16: Cundy, TF, Edmonds, ME, Watkins, PJ. Osteopenia and metatarsal fractures in diabetic neuropathy. Diabet Med 1985; 2:461. 9: Sammarco GJ: The Jones fracture. Instr Course Lect 42:201-205, 1993. 10: DeLee JC, Evans JP, Julian J. Stress fracture of the fifth metatarsal. Am J Sports Med 1983;11:349-353. A 6-month study showed that metatarsal fractures accounted for (majority are 1st and 5th met fx): 35% of foot fractures, 6% of foot injuries, 5% of skeletal fractures, 0.2% of emergency department visits. 11: SPECTOR FC, KARLIN JM, SCURRAN BL, ET AL: Lesser metatarsal fractures: incidence, management, and review. JAPA 74: 259, 1984. Unstable Foot Types Leads to Stress Overload: hypermobile 1st and/or 5th rays causes overload of the lesser mets. GRF GRF Surgical Approach: consider the complex soft tissue anatomy that surrounds, inserts or originates from each of the central metatarsals. -Fractures of the proximal shaft and base must be evaluated for ligamentous disruption. - Manipulation under anesthesia while monitoring with fluoroscopy is recommended. Fracture Treatment Options: -Non-dislocated fractures w/o ligament damage of the second, third, and fourth metatarsal bases rarely need treatment other than solid-soled shoe or, if painful, a cast. -Met fxs are often held in good alignment by surrounding ligamentous structures, with exception of met neck and shaft fractures that displace easily. -3 to 4 mm of medial or lateral transverse plane deformity and 10° or less of angulation are well tolerated and need not undergo surgical corrective measures. -Healing time may be as much as 3 months from injury. -Weight bearing is advanced as tolerated. 12: Armagan OE, Shereff MJ. Injuries to the toes and metatarsal. Foot Ankle Trauma. 2001;32:1–10. Fracture Tx Options: -ORIF is indicated in metatarsal fractures that are irreducible, involve a joint, or are significantly displaced. Fixation options: -crossed K-wires, -percutaneous pinning, -circlage wire, -interfrag screw, -plate and screw fixation, -external fixation, -intramedullary fixation using a Steinmann pin or doublethreaded compression screw . 13:Rammelt S, Heineck J, Zwipp H. Metatarsal fractures. Injury. 2004;35:S-B77–S-B86. 14: Pendarvis JA, Mandracchia VJ, Haverstock BD, et al. A new fixation technique for metatarsal fractures. Clin Podiatr Med Surg. 1999;16:643–657 Evidence for which type of fixation is best in lesser met fractures: -None -Didley Squat -Zilch *Best evidence available is “author’s experience”. *Most authors recommend k-wire/steinman pins or other types of intramed fixation. Evidence from osteotomies similar to met fractures: -40 bone models were divided equally into 4 groups: a control group consisting of intact lesser rays; and Weil osteotomies that were fixated with 2 crossed Kirschner wires (0.045-in K-wires), 2.0-mm cortical screws, or cannulated 2.4-mm cortical screws. Result: There was no statistical difference in structural stiffness among the 3 groups of fixation methods. 20: Craig T. Jex, DPM,1 Chanda J. Wan, DPM,2 Steve Rundell, MS. Analysis of Three Types of Fixation of the Weil Osteotomy. The Journal of Foot & Ankle Surgery 45(1):13–19, 2006. K-Wire Pinning Technique: (same idea as hammertoe fixation) K-Wire Fixation: Fixation Options: k-wires Comminuted Fxs: -Kirschner wire for provisional stability. -Application of mini external fixation devices to the fourth and fifth metatarsal fractures. 15: I, Mosheiff R, Zelgowski A, et al. Crush injuries of the foot with compartment syndrome: immediate one-stage management. Foot Ankle. 1989;9(4):185–189 . IM Rod Fixation Fixation Options: Fixation Options: plate and screws. Fixation Options: k-wires, plate and screws. Complications to be aware of: Significant shortening or angular deviation of mets -may result in transfer lesions/pressure points/new stress fx Early weight bearing with unstable fixationnon unions Pin tract infection vs irritation, hematoma, seroma etc. References: 1: Drez D Jr, Young J, Johnston R, Parker W: Metatarsal stress fractures. Am J Sports Med 8:123-125, 1980. 2: Leabhart J: Stress fractures of the calcaneus. J Bone Joint Surg Am 41:1285-1290, 1959. 3: Daffner R, Pavlov H: Stress fractures: Current concepts. Am J Radiol 159:245-252, 1992. 4: Brukner P, Bradshaw C, Khan KM, et al. Stress fractures: a review of 180 cases. Clin J Sport Med. 1996;6(2):85–9. 5: Milgrom C, Finestone A, Sharkey N, et al: Metatarsal strains are sufficient to cause fracture during cyclic loading. Foot Ankle Int 23(3):230-235, 2002 6: Matheson G, Clements D, McKenzie D, et al: Stress fractures in athletes: A study of 320 cases. Am J Sports Med 15:46-58, 1987. 7: F Banal, F Etchepare, B Rouhier, C Rosenberg, V Foltz, S Rozenberg. Ultrasound ability in early diagnosis of stress fracture of metatarsal bone. Ann Rheum Dis. 2006 July; 65(7): 977–978. 8: Ha K, Hahn S, Chung M, et al: A clinical study of stress fractures in sports activities. Orthopedics 15:1089-1095, 1991. 9: Sammarco GJ: The Jones fracture. Instr Course Lect 42:201-205, 1993. 10: DeLee JC, Evans JP, Julian J. Stress fracture of the fifth metatarsal. Am J Sports Med 1983;11:349-353. 11: Spector FC, Karlin JM, Scurran BL, et al: Lesser metatarsal fractures: incidence, management, and review. JAPA 74: 259, 1984. 12: Armagan OE, Shereff MJ. Injuries to the toes and metatarsal. Foot Ankle Trauma. 2001;32:1–10 13: Rammelt S, Heineck J, Zwipp H. Metatarsal fractures. Injury. 2004;35:S-B77–S-B86. 14: Pendarvis JA, Mandracchia VJ, Haverstock BD, et al. A new fixation technique for metatarsal fractures. Clin Podiatr Med Surg. 1999;16:643–657 15: I, Mosheiff R, Zelgowski A, et al. Crush injuries of the foot with compartment syndrome: immediate one-stage management. Foot Ankle. 1989;9(4):185–189. 16: Cundy, TF, Edmonds, ME, Watkins, PJ. Osteopenia and metatarsal fractures in diabetic neuropathy. Diabet Med 1985; 2:461. 17: Wolf, SK. Diabetes mellitus and predisposition to athletic pedal fracture. J Foot Ankle Surg 1998; 37:16. 18: S Papp, R Sanders. Fractures of the Midfoot and Forefoot. Surgery of the Foot and Ankle. 8th edition. Ch 41 pg 2215. 19: Craig T. Jex, DPM,1 Chanda J. Wan, DPM,2 Steve Rundell, MS. Analysis of Three Types of Fixation of the Weil Osteotomy.. JFAS 45(1):13–19, 2006.