Midfoot Arthritis

 

Introduction

  • Midtarsal and tarsometatarsal joint arthritis is a challenging problem
  • Can result in chronic pain and functional disability
  • Incidence of symptomatic midfoot arthritis is increasing (12% in >50y)

 

Causes

  • Primary (idiopathic)
  • Inflammatory
  • Post-traumatic (most commonly after Lisfranc injuries)

Lisfranc injuries are particularly concerning because as many as 20% may be missed or misdiagnosed

 

Biomechanics

  • Midfoot stability during the mid-stance phase of gait is critical
  • It facilitates forward progression of the body weight on a stable foot
  • Loss of this stability may lead to a failure to position the foot effectively for push-off
  • This affects level walking, ascending/descending stairs and activities that require heel raise

Arthritic changes correspond to flattening of the medial arch and lead to increased tensile stresses on the supporting plantar ligaments on loading, thus worsening the situation. This gait pattern alteration may lead to higher demands of the muscles and ligaments leading to further stress around the midfoot region.

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Clinical Presentation

  • Pain and poor mobility
  • Progressive deformity
  • Inability to perform activities of daily living
  • Issues with foot positioning and wearing shoes

 

Treatment

The primary goals are to:

  • provide pain relief
  • restore midfoot stability
  • modify loads at the affected joints

 

Conservative Treatment

​This is the first line of management and includes analgesia / NSAIDs.

Orthotics

Shoe-wear modifications and foot orthoses can be the mainstay of treatment and can provide support and pain relief. Options include:

  • medial arch support insoles
  • stiff soles
  • rocker bottom soles and ankle-foot-orthoses (AFOs)
  • full-length carbon foot plate (CFP) has proven better than custom three-quarter rigid inserts

​Injections

  • Frequently used for diagnostic and therapeutic purposes with good pain relief
  • Effects can be variable and limited
  • Proven benefits at 2 weeks post ultrasound guided injection; less at 3 months

 

Surgical Treatment

Assessment

  • Weight-bearing radiographs are essential in assessing the tarsometatarsal and naviculo-cuneiform joints
  • Arthritic changes, alignment in the frontal and sagittal planes and assessment of the medial, middle and lateral columns can be made
  • For complex deformity, cross sectional imaging (standing or lying CT +/- MRI scans) is recommended
  • Targeted LA (+/- steroid / hyaluronate) injections under fluoroscopic guidance are useful; beware leakage into adjacent joints

​Surgery

  • Indication: failure of conservative measures
  • Fusing a single midfoot joint in isolation is rare;
    • Consider combination of the first, second and third TMT joints
    • Consider including naviculo-cuneiform joint if symptomatic
  • Joint compression is key

 

Implants

The choice of implant depends on:

  • Surgeon experience and preference
  • Local availability

Screws:

  • Partially-threaded cancellous screws (K-wire placement can aid positioning)
  • Variable pitch, fully-threaded cannulated compression screws may provide a higher fatigue resistance to fracture

Plates:

  • Newer plates have better compressive options
  • Beware of ‘anatomic’ plates - can cause change in MT angle and thus MT head prominence

Adjuncts:

  • Local bone graft or substitutes may be used to augment the union process
  • Autologous cancellous graft easily accessible from heel or distal tibia

 

Outcomes

Anatomical reduction is considered the most important predictor of good outcome.

  • Studies have shown that the age and the mechanism of injury are not significant predictors of outcomes after midfoot arthrodesis
  • PROMS, satisfaction rates, and AOFAS scores significantly improve with surgery
  • Studies have reported good to excellent results in 69% (11/16) of midfoot arthrodesis following failed conservative treatment for Lisfranc injuries
  • Recent studies also report excellent clinical and radiographic outcomes with a union rate of 100%, when using plantar plates in non-smokers and non-neuropathic patients
  • Foot rigidity after arthrodesis is well-tolerated by the patients

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Complications

  • Wound-related problems
  • Infections (3%)
  • Nerve injuries (9%)
  • Neuroma formation (7%)
  • Implant-related problems and screw irritation (9%)
  • Metatarsalgia (6%)
  • Stiffness, secondary arthritis in adjacent joints and CRPS
  • Non-union (3%-7%) due to:
    • isolated plate fixation
    • smoking
    • raised BMI
    • post-operative malalignment
    • neuropathy

 

References

  • Smita Rao, Deborah A. Nawoczenski, Judith F. Baumhauer, Midfoot Arthritis: Nonoperative Options and Decision Making for Fusion, Techniques in Foot & Ankle Surgery 7(3):188–195, 2008
  • Teng AL, Pinzur MS, Lomasney L, Functional outcome following anatomic restoration of tarsal-metatarsal fracture dislocation. Foot Ankle Int. 2002;23:922-926
  • Rao S, Nawoczenski D, Baumhauer J. Shoe inserts alter plantar loading and functional outcomes in patients with midfoot arthritis. Foot Ankle Int. 2007.
  • Kurup H, Vasukutty N. Midfoot arthritis: current concepts review. J Clin Orthop Trauma. 2020 May-Jun;11(3):399-405
  • Fraser TW, Miles DT, Huang N, Davis FB, Dunlap BD, Doty JF. Radiographic Outcomes, Union Rates, and Complications Associated With Plantar Implant Positioning for Midfoot Arthrodesis. Foot Ankle Orthop. 2021 Jul 14;6(3):24730114211027115
  • Drakonaki EE, Kho JS, Sharp RJ, Ostlere SJ. Efficacy of ultrasound-guided steroid injections for pain management of midfoot joint degenerative disease. Skeletal Radiol. 2011 Aug;40(8):1001-6
  • Ahmad J, Lynch MK, Maltenfort M. Comparison of Screws to Plate-and-Screw Constructs for Midfoot Arthrodesis. Foot Ankle Int. 2018 Aug;39(8):922-929. doi: 10.1177/1071100718766658. Epub 2018 Apr 5. Retraction in: Foot Ankle Int. 2019 Mar;40(3):366