Midfoot Fractures and Dislocations

1. Midfoot Fractures and Dislocations Anna N. Miller, MD, and Bruce Sangeorzan, MD University of Washington Harborview Medical Center Based on the work of Drs. A. Walling and C. Jones 1

2. Contents Midfoot Anatomy Mechanisms of Injury Foot Function and Shape Treatment Principles Midfoot Crush External Fixation Internal Fixation Forefoot Crush

3. Midfoot Anatomy Four Major Units 1. 1st Metatarsal (MT) <> Medial Cuneiform: 6° of mobility 2. 2nd MT <> Middle Cuneiform: Firmly Fixed 3. 3rd MT <> Lateral Cuneiform: Firmly Fixed 4. 4th – 5th MT <> Cuboid: Mobile AWAW

4. Midfoot Anatomy Osseous stability is provided by the “Roman arch” of the metatarsals and the recessed keystone of the second metatarsal base AWAW

5. Midfoot Anatomy Associated Structures Dorsalis pedis artery*: between 1st and 2nd MT bases Deep peroneal nerve: runs alongside the artery AWAW

6. Midfoot Anatomy “Column” Anatomy Medial column includes talonavicular joint, cuneiforms, and medial three rays of the forefoot. Lateral column includes calcaneocuboid joint and fourth and fifth metatarsals.

7. Midfoot Anatomy Medial column joints (tarsometatarsals (TMT) 1-3) are qualitatively different from lateral column joints (TMT 4-5) Medial column joints more similar to inter-tarsal joints Medial column joints need to be aligned and stiff Lateral column joints need to be mobile

8. Midfoot Anatomy Lisfranc’s Joint articulation between the cuneifoms + cuboid (aka tarsus) and the bases of the five metatarsals AWAW

9. Midfoot Anatomy

10. Midfoot Anatomy Lisfranc’s ligament: large oblique ligament that extends from the plantar aspect of the medial cuneiform to the base of the second metatarsal **there is no transverse metatarsal ligament between the first and second metatarsals) AWAW

11. Midfoot Anatomy Interosseous ligaments: Connect the metatarsal bases ONLY 2-5, not 1-2 Dorsal and plantar Plantar are stronger and larger Secondary stabilizers: Plantar fascia Peroneus longus Intrinsincs AWAW

12. Motor vehicle accidents 1/3-2/3 of cases Incidence of lower extremity foot trauma has increased with the use of air bags Crush injuries Sports-related injuries are also occurring with increasing frequency AWAW

13. Mechanisms of Injury 54 cadaver Limbs Foot on the brake pedal 2 groups: with and without plantarflexion. Impacted at rate up to 16 meters/second 3/13 of those in neutral position had injury-all at high rates 65% of those in plantar flexion had injury including those at moderate speeds Smith BR, Begeman PC, Leland R, Meehan R, Levine RS, Yang KH, King AI. A mechanism of injury to the forefoot in car crashes. Traffic Inj Prev. 2005 Jun;6(2):156-69

14. Mechanisms of Injury: Direct AWAW

15. Mechanisms of Injury: Indirect AWAW

16. Mechanisms of Injury Indirect: More common (typical athletic injury) Rarely associated with open injury or vascular compromise Direct: Less common (crush) Compartment syndrome more common than with indirect AWAW

17. Mechanisms of Injury: Associated Fractures Forceful abduction of the forefoot may result in: 2nd metatarsal base fracture Compression fracture of the cuboid (“nut cracker”) AWAW

18. Mechanisms of Injury: Associated Fractures Forceful abduction of the forefoot may result in: Avulsion of navicular Isolated medial cuneiform fracture AWAW

19. Foot Function and Shape Plantigrade metatarsal heads On heel rise, the [body weight] x 2.5 is supported by the metatarsal planes Dense plantar ligaments prevent upward migration of metatarsals

20. Foot Function and Shape Lateral column Includes calcaneocuboid and 4,5 metatarsals Shortening = abducto planus deformity

21. Foot Function and Shape Medial column Talonavicular joint, cuneiforms, medial 3 rays Shortening = cavus foot

22. Treatment Principles MUST Restore alignment Protect talonavicular motion Protect 4,5 TMT motion Motion of other joints not important Arthrodesis OK for most small joints

23. Treatment Principles Hindfoot: Protect ankle, subtalar, and talonavicular joints Midfoot: restore length and alignment of medial and lateral “columns” Forefoot: Even weight distribution

24. Midfoot Crush

25. Midfoot Crush External Fixation 4 mm Schanz pins in hindfoot 2.5 mm terminally threaded Schanz pins in forefoot Maintain length and alignment until swelling resolves

26. Midfoot Crush Internal Fixation (Bridging) Restore medial and lateral column Restore anatomy of key joints Span joints with 2.7 recon plate Remove plate at 6 months

27. Midfoot Crush “Internal Fixator” Used as temporary fixation as in previous slide When mobile joints involved, can place multiple internal fixators

28. Midfoot Crush Staged implant removal at six months post-op

29. 25% of poly trauma patients do not return to work at 1 year Lower extremity fractures cause more disability than upper Those with foot injuries score worse in physical function, social function, pain, and physical and emotional role Turchin JOT 1999; MacKenzie Am J Pub Health 1998.

30. Forefoot Crush

31. Forefoot Crush

32. Bony or ligamentous injury involving the tarsometatarsal joint complex Named after the Napoleonic-era surgeon who described amputations at this level without ever defining a specific injury AWAW

33. Generally considered rare 1 per 55,000 people per year 15/5500 fractures As index of suspicion increases, so does incidence ~20% of these injuries overlooked Especially in polytraumatized patients!! AWAW

34. Requires a high degree of clinical suspicion 20% misdiagnosed 40% no treatment in the 1st week Be wary of the diagnosis of “midfoot sprain” AWAW

35. Appropriate mechanism Midfoot pain and difficulty weight bearing Swelling across dorsum of foot & plantar ecchymosis Deformity variable due to possible spontaneous reduction AWAW

36. Ecchymosis may appear late Local tenderness at tarsometatarsal joints OR edematous foot with poorly localized pain Gentle stressing plantar/dorsiflexion and rotation will reveal instability AWAW

37. Check neurovascular status Possible compromise of dorsalis pedis artery Deep peroneal nerve injury COMPARTMENT SYNDROME AWAW

38. AP, Lateral and Oblique Stress views 2 plane instability Standing views provide “stress” and may demonstrate subtle diastasis Comparison views are very helpful

39. Oblique radiograph: Medial base of the 4th metatarsal and medial margin of the cuboid should be aligned AWAW

40. MRI More Radiology Income $$$$$$ CT Confusion, Total

42. Coss, et al.Coss, et al.

43. Absolutely nobody cares Simply determine: Is this a fracture that enters the joint? Or is this a disruption of the supportive ligaments? Is there adequate resistance to dorsal translation of the metatarsals?

44. Early recognition is the key to preventing long term disability Anatomic reduction is necessary for best results: Displacement >1mm or gross instability of tarsometatarsal, intercuneiform, or naviculocuneiform joints is unacceptable Goal: obtain and/or maintain anatomic reduction AWAW

45. Stiff joints: RIGID fixation Flexible joints: FLEXIBLE fixation

46. 1,2,3 TM joints have limited motion Rigid fixation 4,5 TM joints need mobility Flexible or temporary fixation Metatarsal heads need to meet the floor evenly Bones heal, ligaments scar!

47. Plantar tarsometatarsal ligaments intact: short leg walking cast Unstable in 2 planes due to fracture at base: K-wire fixation Unstable in 2 planes due to ligament rupture: rigid fixation or arthrodesis

48. Naviculo-cuneiform not a mobile joint Watch rotation of N-C joints Primary fusion of immobile joints

49. For nondisplaced injuries with normal weightbearing or stress x-rays Short leg cast 4 to 6 weeks NON weight bearing Repeat x-rays to rule out displacement as swelling decreases Total treatment 2-3 months AWAW

50. Surgical emergencies: 1. Open fractures 2. Vascular compromise (dorsalis pedis) 3. Compartment syndrome AWAW

51. 1–3 dorsal incisions 1st incision centered at TMT joint and along axis of 2nd ray, lateral to EHL tendon Identify and protect NV bundle AWAW

52. First reduce and provisionally stabilize 2nd TMT joint Then reduce and provisionally stabilize 1st TMT joint If lateral TMT joints remain displaced, proceed with 2nd or 3rd incision(s) AWAW

53. If reductions are anatomic, then proceed with permanent fixation: Screw fixation for the medial column Countersink to prevent dorsal cortex fracture AWAW

57. Lisfranc Joint Injuries: Operative Treatment 57

58. Screws 3.5 or 4.0 mm fully threaded screws Inserted without lag technique Cannulated screws? Why is a cannulated screw like a rental car? Underpowered Overpriced Driven by someone who doesn’t know where he is going Sigvard T. Hansen, MD

59. Postoperative Management Splint 10 –14 days, nonweight bearing Short leg REMOVABLE boot 4 weeks, nonweight bearing Continue short leg removable boot while graduating weight bearing over 6 weeks AWAW

60. Hardware Removal Lateral column stabilization can be removed at 6 to 12 weeks Medial fixation should NOT be removed before 4 months Some advocate leaving screws indefinitely unless symptomatic AWAW

61. Complications Post traumatic arthritis Present in most, but may not be symptomatic Related to initial injury and adequacy of reduction Treated with arthrodesis for medial column Interpositional arthroplasty may be considered for lateral column AWAW

62. Complications Compartment syndrome Infection Complex regional pain syndrome Neurovascular injury Hardware failure AWAW

63. Prognosis Long rehabilitation (> 1 year) Incomplete reduction leads to increased incidence of deformity and chronic foot pain Loss of rigidity:

64. Prognosis Incidence of traumatic arthritis (0-58%) related to intraarticular surface damage and comminution

65. Prognosis Late collapse:

66. Late Collapse

67. Primary Arthrodesis: Yes or No? Yes Prospective trial 41 patients, 2 groups ‘primarily ligamentous’ injury Fused only medial rays (1,2,3) Significantly better outcomes in arthrodesis group using AOFAS scale at 42 months Pre injury function 92% and 65% 5 patients in ORIF group went on to arthrodesis Ly TV, Coetzee JC. Treatment of primarily ligamentous Lisfranc joint injuries: primary arthrodesis compared with open reduction and internal fixation. A prospective, randomized study. JBJS-A 2006.

68. Primary Arthrodesis: Yes or No? No Retrospective comparison of 28 patients, 3 groups, ‘severe’ injury 12 ORIF; 5 partial and 6 complete arthrodesis Higher pain in arthrodesis group (Baltimore scale) Complications higher in complete arthrodesis Mulier T, Reynders P, Dereymaeker G, Broos P. Severe Lisfrancs injuries: primary arthrodesis or ORIF? Foot Ankle Int 2002.

69. Outcomes 48 patients followed 52 months (13-114) AOFAS midfoot score 77 (90/100=normal) Musculoskeletal Function Assessment (MFA) score 19 (0/100=perfect) 12 with arthrosis, 6 required arthrodesis Ligamentous injuries did worse Kuo RS, Tejwani NC, Digiovanni CW, Holt SK, Benirschke SK, Hansen ST Jr, Sangeorzan BJ. Outcome after open reduction and internal fixation of Lisfranc joint injuries. JBJS-A 2000.

70. Outcomes 11 patients, 41 months after ORIF AOFAS midfoot Score 71 (90=normal) 8/11 had radiographic arthritis In-shoe pressures similar to uninjured side (Tekscan) Teng AL, Pinzur MS, Lomasney L, Mahoney L, Havey R. Functional outcome following anatomic restoration of tarsal-metatarsal fracture dislocation. Foot Ankle Int 2002.

71. Outcomes 46 patients, followed for 2 years 13 had poor outcomes and needed employment change The presence of a compensation claim was associated with a poor outcome (p = 0.02) Calder JD, Whitehouse SL, Saxby TS. Results of isolated Lisfranc injuries and the effect of compensation claims. JBJS-B 2004.

72. Navicular Fractures Anatomy Horseshoe-shaped bone between talus and cuneiforms Numerous short ligaments attach dorsally, plantarly, and laterally Deltoid attaches medially AWAW

73. Navicular Fractures Blood supply: because of the large articular surfaces, vessels can only enter dorsally, plantarly, and thru tuberosity Medial and lateral thirds have good blood supply Central third is largely avascular # of vessels decreases with age AWAW

74. Navicular Fractures Avulsion fractures: usually dorsal lip (essentially severe sprain) Treatment: Immobilization & progressive weight bearing Excision of fragment only if painful AWAW

75. Navicular Fractures Tuberosity fractures: avulsion by posterior tibial tendon and spring ligament Usually minimally displaced May have associated calcaneocuboid impaction ORIF depending on degree of displacement (>5mm) AWAW

76. Navicular Fractures Body Fractures: High energy trauma with axial foot loading Frequently associated with talonavicular subluxation CT scans helpful for preop planning Anatomic reduction essential AWAW

77. Navicular Body Fractures Treatment: ORIF if any displacement Anteromedial incision along medial aspect of tibialis anterior Second anterolateral incision as needed to help reduce lateral fragment AWAW

78. Navicular Body Fractures Courtesy of David P. Barei, MD AWAW

79. Navicular Body Fractures Courtesy of David P. Barei, MD AWAW

80. Navicular Body Fractures May require stabilization or fusion to cuneiforms Avoid fusion of essential talonavicular joint if at all possible AWAW

81. Navicular Body Fractures Prognosis: With adequate reduction most have good result, but few are “normal” Type 3 worst prognosis: Only ½ adequately reduced (60% of joint surface) 6 of 21 developed ostonecrosis with one collapse Sangeorzan BJ, Benirschke SK, Mosca V, Mayo KA, Hansen ST Jr. Displaced intra-articular fractures of the tarsal navicular. JBJS-A 1989. AWAW

82. Navicular Stress Fractures Uncommon; delay in diagnosis common Usually due to repetitive stress and poor blood supply Running most common Diagnosis: vague arch pain with midfoot tenderness X-Rays: AP, lateral, and oblique CT, bone scan, or MRI if uncertain AWAW

83. Navicular Stress Fractures: Treatment Incomplete fracture Non-weightbearing cast until healed (variable time) Complete fracture or nonunion: ORIF with screws perpendicular to fracture plane +/- bone graft Complications: nonunion or persistent pain AWAW

84. Cuboid Fractures Isolated fractures are rare Most often associated with other fractures Two types of fractures usually seen: Avulsion Nutcracker (axial loading with plantar flexion and forefoot abduction) AWAW

85. Cuboid Fractures:Treatment Surgical indicated for: 2 mm displacement of articular surface Cuboid subluxation with weight bearing or stress x-rays Loss of bony length AWAW

86. Cuboid Fractures:Treatment Nondisplaced: immobilization 6-8 weeks Displaced: ORIF Often requires bone graft and small plate Can use small external fixator for distraction May have to bridge joint to stabilize subluxation AWAW

87. Cuneiform Fractures Isolated fractures quite rare Displacement is unusual Mechanisms of injury: Direct trauma Most common Heal rapidly with nonoperative treatment Indirect trauma (Lisfranc variants) May occur in any direction including axial shortening Instability requires ORIF AWAW

88. Summary Midfoot: restore length and alignment relationships of the medial and lateral column Forefoot: plantigrade metatarsal heads

89. Summary Rigid fixation for unstable joints Screws for dislocations of ‘stiff’ syndesmotic joints TMT 1-3 K-wires for dislocations of mobile joints TMT 4-5

90. Summary Bone regenerates, ligaments scar Primary arthrodesis for primarily ligamentous injuries K-wires adequate for metaphyseal fractures ORIF for displaced cuboid and navicular fractures Otherwise non-operative management

91. Summary Crushing injuries: temporize with combined internal/external fixation or bulky splint Small plates, 2.7 and 3.5 reconstruction plates may be used as ‘internal fixators’ to restore shape and alignment.

92. Summary: AGAIN If it is designed to be stiff when functional, you must screw it If it has motion when functional, use K-wires Bone regenerates, ligaments scar Outcome is fairly good when anatomically reduced and not related to workplace compensation.

93. Bibliography

94. Thank You!