Preoperative Planning and Templating in Total Hip Replacement

Introduction

Successful total hip replacement (THR) begins long before the patient enters the operating room. Careful patient evaluation, detailed preoperative planning, and accurate templating are essential for achieving optimal outcomes.

A well-planned procedure helps restore hip biomechanics, minimize complications, and improve implant longevity. This article reviews the key principles involved in evaluating hip disorders and planning for total hip arthroplasty.

Evaluation of Patients with Labral Pathology and Femoroacetabular Impingement

Clinical Assessment

Patients presenting with labral tears or femoroacetabular impingement (FAI) should be evaluated for:

Hip pain
Functional limitations
Mechanical symptoms such as catching, locking, or clicking
Impact on daily activities and sports participation

The primary goals of hip preservation procedures are pain relief and functional improvement rather than guaranteed prevention of future hip replacement.

Expected Recovery Timelines

Recovery varies according to the extent of surgery.

Minor Procedures

Examples:

Labral debridement

Typical recovery:

Approximately 6 weeks

More Extensive Procedures

Examples:

Arthroscopic correction of femoroacetabular impingement
Labral repair with osteoplasty

Typical recovery:

Approximately 4–6 months

Interestingly, recovery following complex hip arthroscopy may be longer and more demanding than recovery after total hip replacement.

Management of Labral Tears: Looking Beyond the Labrum

Early surgical approaches focused primarily on treating the torn labrum.

Although many patients experienced short-term improvement, a significant number continued to have persistent symptoms because the underlying structural abnormalities had not been addressed.

Common missed contributors include:

Cam deformity
Pincer deformity
Capsular pathology
Extra-articular soft tissue disorders

Modern treatment emphasizes identifying and correcting the root cause rather than treating the labral tear in isolation.

Osteonecrosis of the Femoral Head

When Joint Preservation Is No Longer Effective

In osteonecrosis (avascular necrosis), once femoral head collapse has occurred, joint-preserving procedures generally have limited success.

In these situations, total hip replacement is often the most reliable treatment option.

Role of Hip Resurfacing

Hip resurfacing may be considered in carefully selected patients when:

The necrotic lesion is small
Adequate viable bone remains
Bone quality is sufficient to support the implant

Factors influencing suitability include:

Lesion size
Lesion location
Remaining bone stock

Large lesions and poor bone quality make resurfacing less predictable and increase the risk of failure.

Importance of Preoperative Planning

Why Planning Matters

A successful total hip replacement requires meticulous preparation.

Key objectives include:

Understanding the underlying pathology
Developing a clear surgical strategy
Selecting appropriate implants
Ensuring availability of necessary instruments

Poor preparation can lead to intraoperative difficulties, prolonged surgical time, and increased complication rates.

Patient History and Risk Assessment

Essential Components of History Taking

A comprehensive preoperative assessment should include:

Previous Surgical History

Prior hip procedures
Previous fracture fixation
Retained implants

History of Infection

Particularly important because previous infections may increase the risk of periprosthetic joint infection.

Medical Comorbidities

Conditions that may influence surgical outcomes include:

Diabetes mellitus
Cardiovascular disease
Chronic kidney disease
Immunosuppressive disorders

Non-Hip Sources of Pain

Before proceeding with surgery, it is important to exclude:

Lumbar spine pathology
Sacroiliac joint disorders
Neurological conditions
Referred pain syndromes

Failure to identify non-hip pain generators may result in persistent postoperative symptoms.

Patient Counseling

Patients should be informed about potential complications, including:

Infection
Deep vein thrombosis (DVT)
Pulmonary embolism
Dislocation
Neurovascular injury
Medical complications related to surgery

Appropriate counseling improves patient expectations and informed decision-making.

Influence of Medical Conditions on Surgical Strategy

Certain medical conditions can significantly influence implant selection and operative planning.

Neurological and Cognitive Disorders

These conditions may increase:

Instability risk
Falls risk
Dislocation risk

Special implant designs and surgical approaches may be considered to improve stability.

Previous Radiation Therapy

Radiation may affect:

Bone quality
Implant fixation
Healing potential

Additional planning is often required in these patients.

Inflammatory Arthritis

Patients with inflammatory arthritis may have:

Higher infection risk
Poor bone stock
Complex deformities

These factors may influence implant choice and perioperative management.

Complex Hip Reconstruction Cases

Previous Trauma

Post-traumatic arthritis often presents unique challenges:

Retained hardware
Bone loss
Distorted anatomy
Scar tissue

These patients frequently require advanced reconstructive planning.

Childhood Hip Disorders

Conditions such as:

Developmental dysplasia of the hip (DDH)
Perthes disease
Slipped capital femoral epiphysis (SCFE)

can result in:

Abnormal femoral morphology
Acetabular deformity
Leg length discrepancy
Altered biomechanics

Corrective procedures such as osteotomies may occasionally be required to restore alignment and stability.

Physical Examination and Functional Assessment

A structured examination remains essential.

Key Components

Pelvic Assessment

Evaluate:

Pelvic tilt
Pelvic obliquity
Spinal alignment

Hip Range of Motion

Assess:

Flexion
Extension
Internal rotation
External rotation
Abduction
Adduction

Leg Length Evaluation

Determine:

True limb length discrepancy
Apparent limb length discrepancy

Muscle Function

Assess:

Abductor strength
Flexion contractures
Soft tissue balance

Identifying stiffness and deformity helps guide implant positioning and reconstructive strategy.

Imaging and Radiographic Assessment

Standard Radiographs

Preoperative imaging typically includes:

Anteroposterior pelvis
Hip radiographs
Femoral radiographs

These images provide information regarding:

Bone stock
Joint space
Deformity
Implant planning

Advanced Imaging

Computed Tomography (CT)

Useful in complex situations such as:

Dysplasia
Previous fractures
Significant deformity
Revision surgery

CT provides detailed three-dimensional assessment of bony anatomy.

Principles of Templating in Total Hip Replacement

Purpose of Templating

Preoperative templating is a critical step in surgical planning.

Its objectives include:

Estimating implant size
Restoring femoral offset
Re-establishing hip center of rotation
Correcting leg length discrepancies
Anticipating technical challenges

Accurate templating improves precision and reduces intraoperative surprises.

Sequence of Templating

Step 1: Acetabular Planning

The acetabular component is typically templated first.

Goals include:

Restoring the anatomical hip center
Achieving adequate coverage
Optimizing component orientation

Step 2: Femoral Planning

The femoral component is then selected to:

Restore offset
Restore leg length
Achieve stable fixation

Proper coordination of acetabular and femoral reconstruction is essential for recreating normal hip biomechanics.

Goals of Surgical Planning

Successful preoperative planning aims to:

Restore normal hip mechanics
Reconstruct the native center of rotation
Achieve stable implant fixation
Correct leg length discrepancy
Minimize complications
Improve long-term implant survivorship

Ultimately, meticulous planning is one of the most important determinants of a successful total hip replacement.

Key Takeaways

Thorough evaluation is essential before considering total hip replacement.
Hip preservation procedures should address underlying structural pathology, not just symptoms.
Femoral head collapse in osteonecrosis usually warrants arthroplasty rather than joint-preserving surgery.
Careful history, examination, and imaging guide implant selection and surgical strategy.
Complex cases such as dysplasia, childhood hip disorders, and post-traumatic arthritis require additional planning.
Preoperative templating helps restore biomechanics, offset, leg length, and implant stability.
The success of total hip replacement depends as much on preparation and planning as on surgical technique itself.

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