Charcot Neuroarthropathy Review EBM 2024 PDF

Charcot Neuroarthropathy Review A L L E N J K E M P F, D P M , M S , A A C FA S , D A B P M A S S I S TA N T P R O F E S S O R C O L L E G E O F P O D I AT R I C M E D I C I N E A N D S U R G E R Y DES MOINES UNIVERSITY Objectives Identify the goals of Charcot reconstruction surgery Demonst...

Charcot Neuroarthropathy Review A L L E N J K E M P F, D P M , M S , A A C FA S , D A B P M A S S I S TA N T P R O F E S S O R C O L L E G E O F P O D I AT R I C M E D I C I N E A N D S U R G E R Y DES MOINES UNIVERSITY Objectives Identify the goals of Charcot reconstruction surgery Demonstrate knowledge of the various surgical techniques for Charcot reconstruction Recognize the complications of Charcot reconstruction Demonstrate knowledge of the etiology and pathophysiology of neuropathic bone disease Demonstrate knowledge of diagnostic testing and diagnostic features of neuropathic bone disease Identify treatment options for neuropathic bone disease Definition “Charcot foot is a progressive condition characterized by joint dislocation, pathological fractures, and severe destruction of the pedal architecture.” JFAS, Supplement 2000, Diabetic Foot Disorders: A Clinical Practice Guideline, p S39 Etiologies Diabetes Spinal Disorders Tabes dorsalis MS Leprosy CMT Syringomyelia Paraneoplasms Steroids Transplant ◦ Kidney Alcoholism ◦ 20% Pernicious anemia ◦ Kidney-pancreas ◦ 31% Risk Factors Trepman, E, FAI. 2005.  Pathophysiology Increased inflammatory response in the foot Osteoclast – Osteoblast imbalance with increased osteoclasts present Increase in osteoclasts cause lysis of bone leading to more inflammation Leads to bone and joint destruction https://www.sciencephoto.com/media/74491/view/osteoclasts-in-bone-lacunae-sem Pathophysiology – RANK L https://www.researchgate.net/figure/The-role-of-RANKL-in-Charcot-neuroarthropathy_fig1_221683592 Pathophysiology Neurotraumatic theory ◦ Exaggerated overuse injury coupled with loss of protective sensation ◦ Can be initiated by acute trauma or repetitive microtrauma ◦ Lack of sensation allows continued tissue destruction resulting in fractures and dislocations Pathophysiology Neurovascular theory ◦ Vasomotor neuropathy in patients with intact blood flow ◦ Arteriovenous shunting leads to excessive bone resorption and bone weakening ◦ Contributes to fractures and dislocations with continued weightbearing Charcot Classifications Radiographic/Functional ◦ Eichenholtz ◦ Stage 0 (Shibata) Anatomical ◦ Brodsky ◦ Sanders and Frykberg Risk Assessment ◦ Roger’s System Are these classifications useful to guide treatment ? ◦ An opinion – radiographic/ functional and the anatomical classifications on their own are not useful to guide treatment. Combination of the two much more useful to guide surgical treatment options. Eichenholtz Classification Trepman, E, FAI. 2005. Brodsky Classification 20% 10% 60 %  Sanders and Frykberg Classification Anatomic classification system Pattern 1: Metatarsophalangeal joints and distal Pattern 2: Tarsometatarsal joint Pattern 3: Midtarsal joint Pattern 4: Ankle joint Pattern 5: Calcaneus https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682845/figure/Fig6/  Roger’s Charcot Foot Classification System Based on location and stage Location Forefoot to Rearfoot/Ankle Stage Charcot with and without deformity Charcot deformity with ulcer Charcot deformity with osteomyelitis Predictor of Extremity amputation Rogers LC, Bevilacqua NJ. The diagnosis of Charcot foot. Clinics in Podiatric Medicine and Surgery, 2008;25: 43-51 Clinical features Red, hot, swollen foot Temperature difference ◦ >2 degrees Celsius Usually, a sensory neuropathy present Some pain may be present, but does not match amount of destruction Bilateral 9-30% of the time https://www.hmpgloballearningnetwork.com/site/podiatry/article/3959  6 D’s of Charcot Destruction Debris Dislocation Distention Disorganization Increased Density (subchondral sclerosis)  Radiographs ◦ Radiographic findings ◦ Cortical fractures, periosteal reaction, joint debris, deformity, dislocation, rocker-bottom deformity  MRI: Charcot and OM T1 images show decreased signal intensity T2 images show increased signal intensity STIR images show high signal marrow edema MRI Bone marrow edema may be present with both Charcot and OM Bone marrow edema near ulcer, or revealing sinus tracts, suspicious of bone infection Charcot edema present in peri-articular fashion  Nuclear medicine Three phase Te99-MDP bone scan has an 85% sensitivity, but a 55% specificity because of other causes of bone remodeling Ga67 has high false-positive rate In111 has highest sensitivity (87%) and specificity (81%) in detecting osteo in a neuropathic foot  Nuclear Medicine Best approach is to do a combined scan Te99-MDP and Te99-HMPAO (Ceretec) scan is 94% sensitive and 91% specific Te99-MDP and In111 scan is 86% sensitive and 94% specific Te99-Sulfur Colloid and In111 more recently has also been shown to be effective  Nuclear Medicine (+) Te99- (+) WBC Osteomyeliti MDP scan s (+) Te99- (-) WBC Charcot MDP scan (-) Te99- (+) WBC Soft tissue MDP scan infection (cellulitis) (-) Te99- (-) WBC No osteo or MDP scan active Charcot Osteomyelitis or Charcot? Presence of ulcer can complicate diagnosis ◦ Xray findings will be similar for both ◦ May need further imaging ◦ Bone scans, MRI ◦ Bone biopsy “gold standard” https://www.tsc-deutschland.de/wp-content/uploads/2017/08/2012-eng-bd-jamshidi.pdf  Bone Biopsy “Gold standard” for diagnosing Charcot vs. Osteomyelitis is bone biopsy with culture Biopsy will show bone and cartilage debris embedded in synovium Helpful to culture organisms in the bone because bone pathology is not very specific Before biopsy, patient needs to be off antibiotics for at least three half-lives  Charcot Sequelae Foot and ankle deformity Increased pressure Ulceration Soft tissue and bone infection Partial amputation Limb loss 25%-30% chance of developing Charcot in the contralateral extremity Death Conservative Care Extra-depth or custom molded shoe and a pressure relieving orthotic ◦ If not severe rocker- bottom deformity TOTAL CONTACT CAST CAM BOOT CROW WALKER AFO (ARIZONA BRACE)  Conservative Care External bone growth stimulators? Bisphosphonates? Calcitonin? Denosumab (Prolia)? ◦ RANK-L antibody  Treatment Stage I ◦ Ideally keep NWB in total contact cast or boot until consolidation occurs and/or temperature stabilizes ◦ Recent studies have shown WB in boot or total contact cast can also stabilize foot if damage is in midfoot and not hindfoot ◦ May take months (9 weeks – 11 months) Stage II ◦ Continued protected weight bearing Stage III ◦ Custom orthotics or braces  Treatment of Charcot Deformity Treatment is “reactive” Do not have the ability to screen or predict who or when a Charcot event will occur The goal of treatment whether it be surgical or non-surgical is to achieve a stable and plantigrade foot that enables functional ambulation with footwear and bracing or a stable limb for transfers. Common Reasons to Operate in the Literature Recalcitrant ulcers despite appropriate offloading trial Acute fractures and dislocations in the hindfoot and ankle Unstable and painful foot and ankle deformity Resecting infected bone in cases of osteomyelitis Achilles tendon lengthening to mitigate midfoot forces Rogers et al, “The Charcot Foot in Diabetes” Diabetes Care, Vol 34, September 2011, 2123- 2129 Surgical Treatment Management of soft tissue and osseous infections ◦ Need to eradicate all soft tissue and osseous infections before final reconstruction for optimal, lasting outcomes Amputation ◦ Partial foot ◦ Below Knee or Above Knee ◦ Consider in patients who medically and psychologically are not prepared for long treatment period with almost guaranteed complications  Surgical Treatment Exostectomies Arthrodesis procedures Realignment osteotomies ◦ Can be achieved via external fixation, internal fixation or a combination of both Management of soft tissue and osseous infections Amputation ◦ Partial foot ◦ Below Knee or Above Knee Surgical Treatment Extensive medical workup is required to clear patient for surgery and more important for the postoperative healing period ◦ NWB or PWB is typically required and can have a large impact on cardiopulmonary function Must optimize vascular status Renal disease has a large impact on outcomes Cardiac status ◦ Ejection fraction of 55% required for minimal risk of postoperative cardiac complications Surgical Treatment In general, perform more simple procedures to more complex Correction of equinus deformity Exostectomies - not typical for hindfoot and ankle When foot is structurally stable and bony prominence is underlying etiology Arthrodesis and Osteotomy procedures When architecture of foot and ankle is not structurally stable When to Perform Surgery in Acute Charcot Events Ankle and hindfoot trauma with fracture and/or dislocation Calcaneus fractures with and without ulcers Severe Charcot event in patients with contralateral proximal leg amputations or recent contralateral foot and ankle reconstruction When to Perform Surgery ? Ankle and Rearfoot “Given the common failures of nonsurgical management of CN of the ankle, the task force members agree that surgical management could be considered a primary treatment.” ◦ Task force 15 experts from around the globe Rogers et al, “The Charcot Foot in Diabetes” Diabetes Care, Vol 34, September 2011, 2123- 2129 When to perform Surgery in Chronic Charcot Ulcers not amenable to conservative care in a timely fashion ( weeks to months?) Deformities that are unable to be braced Instability of foot and ankle Chronic pain in the foot and ankle External Fixation Common for some type of post operative issues Pin tract infections most commonly reported ◦ Studies report between 5 to 100 % Variability in literature on descriptions of complications and underlying factors ◦ Definition of a major versus minor complication Diabetes plays a major role in complications Preventing Complications Many complications can be avoided by technique in the OR ◦ Safe zone application of pins and wires ◦ Pre op sizing of rings ◦ Allow sizing adjustment for ESRD on dialysis to allow for some swelling ◦ Technique for application of pins and wires Post operative care ◦ Pin site care ◦ Controlling edema in operative limb Post operative weight bearing Conclusions Foot and ankle Charcot is a reactive disease The treatment goal of the Charcot foot is to allow a plantigrade braceable foot that is not prone to further breakdown. Development of Evidence Based Medicine principles for surgical versus non-surgical treatment is difficult due to the variability of patients, the Charcot event, and the treating surgeons approach