Midfoot Arthritis

This is an extremely complex case of severe pan-midfoot arthritis secondary to rheumatoid arthritis (RA) with several critical decision points. The KEY surgical question is whether to include the lateral column (4th-5th TMT joints) in the fusion construct given that they are SEVERELY arthritic, which contradicts the usual teaching to preserve lateral column motion. This requires careful analysis of the SPECIFIC indications for lateral column fusion and detailed counseling about the functional implications. For ASSESSMENT OF LATERAL COLUMN: The general principle in midfoot fusion is to PRESERVE lateral column motion when possible (Komenda et al, Foot Ankle Int 1996) because the 4th-5th TMT joints provide essential flexibility for gait adaptation on uneven surfaces. However, this principle applies when the lateral column is NOT significantly arthritic. The INDICATIONS for INCLUDING lateral column in fusion are: (1) SEVERE symptomatic arthritis of 4th-5th TMT joints - which this patient clearly has ('advanced arthritis with near-complete joint space loss, similar severity to medial/middle columns'), (2) INFLAMMATORY arthropathy causing progressive destruction - RA continues to attack any remaining synovial joints, so leaving diseased lateral column joints unfused risks ongoing pain and progression, (3) FAILED conservative management including injections - she has had multiple injection series with diminishing returns, (4) Midfoot INSTABILITY or significant deformity - she has some arch collapse and dorsal subluxation suggesting instability. In this specific case, I would AGREE with the referring surgeon that pan-midfoot fusion including the lateral column is indicated because the lateral column is SEVERELY and SYMPTOMATICALLY arthritic. This is one of the few situations where lateral column fusion is appropriate. The alternative - preserving severely arthritic lateral column joints - would leave a persistent pain source and risk progressive deformity. However, I would clearly counsel the patient about the FUNCTIONAL IMPLICATIONS of lateral column fusion: The fused midfoot will be COMPLETELY RIGID with no adaptive motion. She will have difficulty on uneven ground, stairs, and slopes. Walking will require MORE ankle and hip motion to compensate. There is risk of TRANSFER STRESS to adjacent unfused joints (particularly navicular-cuneiform joints if any are preserved, and intercuneiform joints). Some patients find the rigid midfoot uncomfortable despite pain relief. For the EXTENT OF FUSION, I would plan: (1) All five TMT joints (1st through 5th) - clearly indicated given advanced arthritis across all TMT joints, (2) Naviculocuneiform joints - the imaging and MRI show these are also involved. I would plan to include these in the fusion. In inflammatory arthropathy, it's better to fuse all diseased joints in one procedure rather than stage (staged procedures risk incomplete pain relief and need for revision), (3) Intercuneiform joints - I would assess INTRAOPERATIVELY. If there is significant synovitis and cartilage destruction, I would fuse them as well to prevent a future pain source. Some surgeons routinely fuse all intercuneiform joints in RA midfoot fusion to prevent progression. (4) Cuboid-cuneiform joint and calcaneocuboid joint - typically PRESERVED unless severely involved. These are extra-articular to the main midfoot complex. This would be a MASSIVE midfoot arthrodesis. For NONUNION RISK in this patient - this is a CRITICAL concern: Baseline nonunion rate for medial/middle column TMT fusion is 5-10%. However, this patient has MULTIPLE risk factors for nonunion: (1) EXTENSIVE fusion (more joints = higher nonunion risk, pan-midfoot fusion has nonunion rates 15-25%), (2) LATERAL column inclusion (4th-5th TMT have HIGHER nonunion rates than medial column - up to 20-30% in some series), (3) RHEUMATOID ARTHRITIS (inflammatory arthropathy increases nonunion risk), (4) IMMUNOSUPPRESSION - methotrexate and adalimumab (biologics) - controversial but may impair bone healing, (5) Bone quality - RA causes osteopenia and erosive bone damage, (6) Smoking status (need to ask). Given these risks, I would quote her a nonunion risk of 20-30% for this extensive fusion. This is REALISTIC counseling - under-promising and over-delivering is better than the reverse. To MINIMIZE nonunion risk: (1) Meticulous surgical technique with thorough joint preparation and stable fixation (locking plates for better purchase in osteopenic bone), (2) Consider bone grafting - autograft from calcaneus or iliac crest, or allograft/bone graft substitute to augment healing, (3) PERIOPERATIVE DMARD MANAGEMENT - this is controversial. Current evidence (Goodman et al, JBJS Am 2015) suggests: METHOTREXATE - STOP 2 weeks pre-op, restart 2 weeks post-op (as rheumatology suggested), BIOLOGICS (adalimumab) - traditionally withheld perioperatively due to infection concerns, but recent data shows withholding increases flare risk and may not improve healing. The rheumatology advice to CONTINUE adalimumab is reasonable but I would discuss that this is a controversial area and may affect healing. Could consider stopping 1 cycle pre-op (2 weeks for adalimumab given its half-life) and restarting once wound healed (3-4 weeks post-op) as a compromise, (4) Post-operative protocol - STRICT non-weight-bearing for 8-12 weeks (longer than standard fusion given extensive nature and nonunion risk), then progressive weight-bearing in boot, (5) Bone stimulator - consider adjunctive bone stimulator (pulsed electromagnetic field or low-intensity pulsed ultrasound) though evidence is mixed, (6) Smoking cessation if applicable (absolute requirement), (7) Optimize nutrition, vitamin D, calcium. For REVISION SURGERY if nonunion occurs: If nonunion develops (typically evident at 4-6 months post-op if patient has persistent pain and mobility at fusion site), options include: (1) REVISION fusion - take down nonunion, repeat joint preparation, bone grafting, revision fixation with better/different hardware. May need to temporarily STOP immunosuppression if possible (coordinate with rheumatology - may not be feasible if RA very active), (2) If PERSISTENT nonunion despite revision - consider exision arthroplasty of nonunion site (essentially creating a pseudarthrosis - controversial and unpredictable), (3) If extensive hardware failure or infection - may need staged revision with temporary external fixation, (4) If MULTIPLE nonunions and patient has acceptable pain control - may elect to leave alone if fibrous union provides stability. Revision midfoot fusion surgery has LOWER success rates (union rates 60-75% vs greater than 90% for primary fusion) and higher complication rates. Finally, I would discuss the ALTERNATIVE of lesser surgery - could we do a MEDIAL COLUMN-only fusion initially and see if that provides sufficient pain relief, preserving lateral column despite its arthritis? This would be a COMPROMISE with potentially less functional impairment but risk of incomplete pain relief and need for later lateral column fusion (staged approach). Given her severe lateral column involvement and failed conservative measures, I would NOT recommend this - I think it would lead to persistent lateral foot pain and likely revision surgery. Better to do definitive pan-midfoot fusion as single procedure. OVERALL RECOMMENDATION: Proceed with pan-midfoot arthrodesis including lateral column given extensive disease, but counsel extensively about: (1) High nonunion risk (20-30%) requiring potential revision surgery, (2) Complete midfoot rigidity with functional limitations, (3) Long rehabilitation (6-12 months to full function), (4) Need to coordinate DMARD management with rheumatology, (5) Possibility of transfer stress to adjacent joints long-term. Despite these concerns, if conservative measures have genuinely failed and her pain is significantly impacting quality of life, fusion is the only definitive option. Patient needs to understand this is complex salvage surgery with significant risks, not a routine procedure.