Radiological Report - Left Hip X-Ray

Primary Finding - Heterotopic Ossification / Myositis Ossificans

Characteristics of the Mass:

"Radiographically, myositis ossificans appears as irregularly shaped masses of heterogeneous bone in the soft tissues... It can be seen as early as 10-21 days after injury... CT can be helpful in distinguishing between neoplasm and myositis ossificans, because lesions of myositis ossificans begin to calcify at the periphery and progress toward the center."

• Rosen's Emergency Medicine, p. 689

"Radiographs show peripheral mineralization with a central lucent area as maturation progresses. The lesion is not attached to the underlying bone, but in some cases it may become fixed to the periosteal surface."

Left Hip Joint Assessment

• Joint space: Well-preserved and symmetric - no joint space narrowing
• Femoral head: Normally shaped, no avascular necrosis, no subcortical collapse or sclerosis
• Acetabulum: Smooth margins, intact roof, no dysplasia or protrusio
• No osteophytes or subchondral cysts - no features of osteoarthritis
• Femoral neck: Normal neck-shaft angle (approximately 125-130°), no coxa vara or valga
• Greater and lesser trochanters: Intact, no avulsion fractures

Right Hip (Contralateral - Seen on AP View)

• Normal hip joint space
• No obvious pathology on this limited view
• Provided for comparison only

Pelvis Assessment

• Pelvis appears symmetric without obvious tilt or obliquity
• Sacroiliac joints appear normal
• No pelvic ring fractures
• Pubic symphysis appears intact

Differential Diagnosis for the Soft Tissue Calcification

Impression

1. Large mature myositis ossificans (heterotopic ossification) of the proximal left femoral soft tissues, most likely post-traumatic in etiology. The lesion appears mature based on the well-organized peripheral ossified shell.
2. Left hip joint is preserved - no osteoarthritis, avascular necrosis, or fracture.
3. No aggressive periosteal reaction or cortical destruction.

Recommended Next Steps

1. Clinical correlation: Confirm history of prior trauma, repeated injury, or prior hip surgery (incidence of HO after hip surgery ~2%)
2. MRI left hip: To better characterize the mass, assess medullary involvement, and exclude soft tissue malignancy if clinically warranted
3. CT scan: Can confirm the classic peripheral-to-central calcification pattern ("zoning phenomenon") and definitively exclude attachment to cortex
4. Orthopedic review: If the mass causes pain or limits range of motion, surgical excision may be considered - but only after the lesion has fully matured (typically 6-18 months after injury onset, confirmed by isotope bone scan showing quiescent activity)
5. Bone scan (Tc-99m): Useful to confirm maturity of the lesion before any planned surgery

Fig. 47.7 from Rosen's Emergency Medicine - Mature Myositis Ossificans of the Proximal Femur, showing well-organized peripheral calcifications

Physiotherapy in Myositis Ossificans - Proximal Left Femur

Phase 1: Acute / Active Inflammatory Stage

Do's:

• Rest the hip in a functional position - hip in slight flexion/abduction with neutral rotation (use positioning aids)
• RICE: Rest, Ice (15-20 min, 3-4x/day), Compression, Elevation where possible
• Gentle passive range of motion (PROM) - initiated as early as possible, within pain-free range, to prevent ankylosis
• Isometric exercises for quadriceps and gluteals to maintain muscle tone without stressing the lesion
• Electrotherapy - TENS for pain control (safe at this stage)

Absolute Contraindications in active stage:

"Resting the joint appears more likely to lead to decreased ROM or ankylosis." - Medscape / AAPMR KnowledgeNow (2024)

Phase 2: Subacute / Maturing Stage

Key Physiotherapy Interventions:

• Passive ROM (PROM): Gentle, slow, sustained stretches within comfortable range
• Active-Assisted ROM (AAROM): Patient participates with therapist assistance
• Active ROM (AROM): Independent movement through full range
• Focus on: Hip flexion, extension, abduction, adduction, internal and external rotation
• Progress gradually - avoid pain during exercise
• The consensus is that PROM and continued mobilization, once acute inflammation has subsided, are indicated to maintain ROM (Medscape HO Management, 2024)

• Isometric → isotonic progression
• Hip flexors (iliopsoas), extensors (gluteus maximus), abductors (gluteus medius), quadriceps, hamstrings
• Aquatic exercises: excellent option - buoyancy reduces load, allows greater ROM with less pain
• Closed kinetic chain exercises when tolerating weight-bearing

• Massage to surrounding musculature (NOT directly over the calcified mass)
• Myofascial release to hip flexors, adductors, TFL if shortened
• Scar tissue / fascial mobilization around the lesion margins

• Assess and correct any antalgic gait pattern
• Correct Trendelenburg if gluteus medius is weak
• Progress from walking aids to independent ambulation
• Stair training and functional task retraining

Phase 3: Mature Stage (Current Stage - Based on X-Ray)

Physiotherapy Focus:

• Resistance training: Hip abductors, extensors, flexors
• Functional strengthening: Squats, lunges, step-ups (pain-guided)
• Core stability: Transversus abdominis, multifidus activation
• Proprioceptive training: Single-leg balance, unstable surface training

• Daily sustained stretching of hip flexors, adductors, IT band
• Yoga / Pilates-based movements for hip mobility
• Hydrotherapy / aquatic therapy remains excellent at this stage

• ADL training - sitting, rising from floor, climbing stairs
• Return to work / sport-specific training if applicable
• Ergonomic advice for occupation

• Explain the nature of the lesion - it is benign and stable
• Teach self-ROM exercises for home program
• Warn about avoiding re-trauma to the area
• Signs of reactivation to watch for (new warmth, swelling, pain)
• Importance of regular follow-up

Pre-Surgical Physiotherapy (If Surgery is Planned)

• Optimize pre-operative strength and ROM as much as possible
• Prehabilitation - respiratory exercises, cardiovascular fitness
• Confirm maturity of lesion before surgery (bone scan showing "cold" uptake)
• Typically surgery is deferred until 6-18 months after initial injury or until mature

Post-Surgical Physiotherapy (After Surgical Excision):

1. Gentle PROM started 72 hours post-operation
2. Progressive intensity over weeks
3. Retraining in functional activities - transfers, walking, stairs
4. NSAIDs (indomethacin) or low-dose radiation may be given post-surgically to prevent recurrence - physiotherapy complements this
5. Full return to function over 3-6 months

Summary - Physiotherapy Goals by Phase

Critical Points for This Patient (40-year-old male, mature lesion)

1. Do not apply deep heat or ultrasound directly over the calcified mass - this remains contraindicated even in the mature stage
2. Deep tissue massage directly on the ossified area is contraindicated
3. The left hip joint space is preserved - this is favorable, meaning full functional recovery is achievable
4. Regular reassessment of hip ROM is needed to detect any progressive restriction
5. If the lesion causes no functional limitation, observation with a home exercise program is sufficient
6. Coordinate with the orthopedic surgeon and physiatrist - physiotherapy is part of a multi-disciplinary team approach