Rare Bone Disorders:
Sequoia Medical 360

Not all bone problems are osteoporosis. Some conditions are uncommon, frequently missed, and highly treatable once correctly identified. At Sequoia Medical 360, we specialize in the diagnosis and management of rare and complex metabolic bone diseases—from Paget’s disease of bone and Tumor-Induced Osteomalacia (TIO) to hypophosphatasia, scurvy, and other causes of osteomalacia (soft bone). Our goal is straightforward: find the cause, fix the biology, and restore function.
Guided by Dr. Tony Mathews (dual fellowship in Preventive Cardiology & Endocrinology, board-certified in Obesity Medicine and Clinical Lipidology), we pair advanced lab analysis with targeted imaging and an individualized treatment plan that protects bone strength, mobility, and longevity.

When to Suspect a Non-Osteoporosis Bone Disorder

Diffuse bone pain, tenderness, or stress fractures with normal or near-normal DXA
Low phosphate or elevated alkaline phosphatase without a clear reason
Recurrent fractures, slow fracture healing, or unusual radiographic changes
Bone deformities (bowing, skull enlargement), hearing loss, or nerve compression
Muscle weakness, fatigue, difficulty rising from a chair, waddling gait
Nutritional risks (restricted diets, alcoholism, eating disorders, malabsorption)
Chronic kidney, GI, or oncologic history; use of certain meds (antiepileptics, chemo)

If this sounds familiar, a specialized metabolic bone evaluation can be game-changing.

Conditions We Diagnose & Treat

Paget’s Disease of Bone

A focal disorder where areas of bone remodel too quickly and chaotically, leading to pain, deformity, warmth over the bone, fractures, and sometimes hearing loss (skull involvement). Often discovered by elevated alkaline phosphatase or abnormal X-ray.

Evaluation
Serum alkaline phosphatase, calcium, vitamin D
Plain films targeted to painful sites; radionuclide bone scan to map extent
Treatment
Potent IV bisphosphonate (e.g., zoledronic acid) is first-line to normalize turnover and reduce pain; adjunct analgesia/PT; hearing and dental coordination when skull/jaw involved.
Periodic monitoring of alkaline phosphatase to track response/relapse.

Tumor-Induced Osteomalacia (TIO) / FGF23-Mediated Hypophosphatemia

A rare, reversible cause of osteomalacia driven by small, often benign tumors that oversecrete FGF23, causing phosphate wasting and low active vitamin D. Hallmarks: deep bone pain, proximal muscle weakness, recurrent insufficiency fractures, low serum phosphate, high FGF23

Evaluation
Serum phosphate (low), FGF23 (high), 1,25-OH₂ vitamin D (low/normal), alkaline phosphatase (high); urine phosphate wasting
Functional imaging (e.g., PET/CT) and targeted MRI to localize the culprit tumor
Treatment
Surgical removal is curative when feasible.
If not localizable/resectable, options include phosphate + active vitamin D replacement and FGF23-targeted therapy (e.g., burosumab) under specialty protocols.
Fracture prevention via activity modification, PT, and fall-risk reduction while bone remineralizes.

Osteomalacia (Non-Tumor Causes)

“Soft bone” from defective mineralization, most commonly due to vitamin D deficiency, malabsorption, severe phosphate deficiency, or renal phosphate wasting (non-TIO). Patients report diffuse bone pain, tender ribs/pelvis, and proximal muscle weakness; x-rays can show Looser’s zones (pseudofractures).

Evaluation
25-OH vitamin D, calcium, phosphate, PTH, alkaline phosphatase; assess GI/renal contributors and medications; consider 24-hr urine calcium/phosphate
Accountability cadence: Regular touchpoints (in-person or telehealth), quick chats for medication/side-effect tuning, and data-driven micro-adjustments.
Treatment
Vitamin D repletion and calcium as needed; correct phosphate deficiency and underlying GI/renal issues.
Structured strength + balance program once pain improves; repeat labs/imaging to confirm remineralization.

Hypophosphatasia (HPP)

A genetic deficiency of tissue-nonspecific alkaline phosphatase, leading to accumulation of inhibitors of mineralization. Adults can have recurrent metatarsal fractures, tooth loss, muscle pain, and low serum alkaline phosphatase (clue!).

Evaluation
Persistently low ALP, elevated PLP (vitamin B6); genetics when indicated; dental history
Treatment
Supportive bone care; enzyme replacement (asfotase alfa) in selected patients under specialty criteria; avoidance of antiresorptives that may worsen HPP.

Scurvy (Severe Vitamin C Deficiency)

Still seen in adults with restricted diets, alcoholism, eating disorders, or malabsorption. Vitamin C is essential for collagen cross-linking; deficiency causes bone pain, gum bleeding, perifollicular hemorrhage, fatigue, and delayed wound/fracture healing.

Evaluation
Dietary review; serum vitamin C (context-dependent); rule out co-deficiencies (vitamin D, iron, folate)
Treatment
Vitamin C supplementation and nutrition rehab; parallel workup for other micronutrient deficits; progressive return to load-bearing.

Other Entities We Consider (and Coordinate Care For)

Osteogenesis imperfecta (adult forms)—fracture-prone collagen disorders
Renal osteodystrophy—CKD-related mix of high/low turnover bone disease
Drug-related bone disease—long-term anticonvulsants, aromatase inhibitors, GnRH analogs, glucocorticoids
Osteonecrosis (avascular necrosis)—ischemic bone collapse (hip/shoulder), rapid escalation pathway
Phosphate disorders beyond TIO—hereditary hypophosphatemias (e.g., XLH), oncologic causes

Our Diagnostic Approach: Precise, Problem-Oriented

1. Laboratory Patterning
Calcium, phosphate, alkaline phosphatase, 25-OH vitamin D, PTH
FGF23, 1,25-OH₂ vitamin D, PLP (vitamin B6), magnesium when indicated
24-hour urine (calcium, phosphate) for renal wasting vs. low intake
2. Imaging Tbhat Answers the Right Question
Targeted x-rays for pseudofractures; radionuclide bone scan for Paget’s mapping
PET/CT or dedicated MRI to localize FGF23-secreting tumors in TIO
DXA for context (density) knowing quality/mineralization may be the bigger issue
3. Function & Safety
InBody 770 body composition to support muscle preservation
Gait/balance assessment; fall-risk mitigation; dental/ENT when skull/jaw involved
4. Root-Cause Mindset
Nutrition consults; GI/renal/oncology collaborations; medication optimization

Treatment Principles We Follow

Fix the driver first (replace missing nutrients, remove tumor, correct renal/GI losses).
Use bone-active therapies thoughtfully: e.g., IV bisphosphonate for Paget’s; avoid antiresorptives in hypophosphatasia; consider anabolic options only when biology supports it.
Rebuild capacity with staged strength, mobility, and impact progression as pain resolves.
Monitor what matters: symptoms, function, alkaline phosphatase/phosphate, vitamin levels, and imaging when indicated.

Why Sequoia Medical 360 for Rare Bone Disorders

Metabolic detective work: We read lab/imaging patterns that others miss.
Advanced tools: Comprehensive phosphate/FGF23 panels, 24-hr urine analytics, functional imaging coordination.
Direct Physician Counsel: Ample, scheduled exam time and streamlined communication to review results with the depth your physiology requires.
Team-based care: Seamless collaboration with radiology, oncology, ENT, nephrology, orthopedics, nutrition, and dentistry.
Bone Health
Osteoporosis
Hypocalcemia
Hypercalcemia

Take the Next Step

If you’re living with unexplained bone pain, weakness, fractures that don’t make sense, low phosphate, or high alkaline phosphatase, we can help you get answers—and get better.

Meet Dr. Mathews
The Sequoia Standard
Request Enrollment
https://sqmed360.com/
Tony Mathews, MD 116 Kraft Ave, Suite 4 Bronxville NY 10708
(914) 292-0300
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