What specialty should an adult or adolescent patient with unequal leg height and low back pain be referred to?

Referral Specialty for Unequal Leg Height Causing Low Back Pain

For patients with leg length discrepancy (LLD) causing low back pain, initial management should focus on conservative orthotic correction rather than immediate specialist referral, but when specialist consultation is needed, refer to physiatry (physical medicine and rehabilitation), orthopedic surgery, or a spine specialist depending on symptom severity and treatment response.

Initial Conservative Management Approach

The evidence strongly supports that LLD-related low back pain responds well to conservative treatment before requiring specialist intervention:

• Heel-lift orthotics with 100% LLD correction are highly effective, with dramatic pain reduction from average NPRS 7.8 to 1.1 at 4 months and complete pain resolution (NPRS 0) at 2 years, while simultaneously improving postural parameters 1
• Correction should be implemented with external or internal shoe lifts matched to the measured discrepancy, with spine adjustment to new static conditions typically occurring within 2 weeks in 83.7% of patients 2
• The adaptation period requires 3-24 months (average 11.3 months) for real equalization, and some patients (14.7%) may experience slight low back pain during this adjustment phase 2

When to Consider Specialist Referral

Referral becomes appropriate under specific circumstances rather than as first-line management:

Timing for Referral

• After 3 months of failed conservative treatment including appropriate orthotic correction, as guidelines suggest this minimum timeframe before considering specialist consultation 3
• Earlier referral (within 2 weeks) is warranted if severe radicular pain develops, neurological deficits appear, or symptoms progress despite treatment 3

Red Flags Requiring Immediate Referral

• Progressive neurological deficits (motor weakness, sensory changes in nerve root distribution) 4, 5
• Cauda equina syndrome symptoms (urinary retention, bilateral lower extremity weakness, saddle anesthesia) 3
• Symptoms suggesting non-mechanical causes such as inflammatory spondyloarthropathy, which may present with chronic low back and extremity pain mimicking mechanical LLD-related pain 6

Appropriate Specialist Options

The choice of specialist depends on clinical presentation and local expertise:

Primary Specialist Options

• Physiatry (Physical Medicine & Rehabilitation): Ideal for comprehensive biomechanical assessment and conservative management optimization, particularly when LLD correction alone is insufficient 1
• Orthopedic Surgery or Spine Surgery: Appropriate when structural correction is being considered or when symptoms persist beyond 1 year despite conservative measures 3
• Rheumatology: Essential if inflammatory conditions are suspected, as non-mechanical causes can mimic LLD-related mechanical pain 6

Decision Framework

• Expertise in low back pain management varies substantially among clinicians from different disciplines, so referral decisions should be individualized based on the primary care clinician's experience, patient symptom response, and availability of specialists with relevant expertise 3

Critical Clinical Considerations

Diagnostic Confirmation Before Referral

• LLD measurement must be performed in standing position using blocks of adequate thickness, assessing posterior superior iliac spine position, as LLD <2 cm is a static disorder requiring proper measurement technique 2
• Radiographic assessment of the entire pelvis and lumbar spine in erect posture is essential to confirm pelvic tilt and lumbar scoliosis before attributing low back pain to LLD, as correlation between leg length inequality and lumbar scoliosis can be poor 7

Biomechanical Understanding

• Symptoms typically occur on the side of the longer extremity (79-89% of cases), due to compensatory bending and rotational forces needed to balance lateral imbalance from LLD of 5-25 mm 8
• LLD causes pelvic obliquity and lumbar scoliosis with convexity toward the shorter extremity, leading to posture deformation, gait asymmetry, and potential discopathy if left unequalized 2

Common Pitfalls to Avoid

• Do not refer immediately without attempting orthotic correction first, as the vast majority of LLD-related low back pain resolves with appropriate heel lifts 1, 2
• Do not assume all low back pain with LLD is mechanical—screen for red flags and non-mechanical causes that may require different specialist referral 6
• Do not expect immediate results—patients need adequate adaptation time (3-24 months) and may experience transient discomfort during adjustment 2
• Do not rely solely on leg length measurement—obtain standing radiographs of pelvis and spine to confirm the biomechanical relationship between LLD, pelvic tilt, and lumbar scoliosis 7