Total Hip Replacement - Direct Lateral Approach (Hardinge/Transgluteal)

Primary Indications

Relative Contraindications

• Active infection: Absolute contraindication until treated (stage 1 revision after eradication)
• Poor soft tissues: Previous burns, radiation, severe scarring over lateral hip (consider alternative approach)
• Severe osteoporosis: Concern for GT fracture and poor repair healing (consider cemented technique, alternative approach)
• Young active patients: Prefer approaches with lower abductor dysfunction risk (posterior, anterior) - preserves function
• Obese patients: Difficult lateral positioning, increased wound tension, higher complication rate (consider anterior if morbidly obese)
• Severe coagulopathy: Correct before surgery (higher bleeding risk with muscle splitting)
• Medical comorbidities: Severe cardiac/respiratory disease requiring optimization
• Patient expectation: High-level athletes or patients requiring rapid return to running/impact sports (abductor dysfunction problematic)

Lateral vs Other Approaches - When to Choose

Choose Lateral Approach When:

• Need excellent exposure of BOTH acetabulum and femur (complex primary, DDH)
• Stability paramount (revision for recurrent dislocation - though usually use posterior with soft tissue repair)
• Surgeon very experienced with lateral technique
• Historical preference/training

Prefer Posterior Approach When:

• Standard primary THA (most common approach worldwide - 60-70%)
• Need extensile exposure for revision
• Want to preserve abductors (lower dysfunction risk)
• Need femoral access for revision femoral component

Prefer Anterior Approach When:

• Young active patients wanting rapid recovery
• Desire lowest possible abductor dysfunction risk
• Outpatient or rapid discharge protocol
• Patient positioned supine desired

CURRENT TREND: Lateral approach declining use (was most common 1970s-1990s, now third choice) due to abductor dysfunction (20-30%). Most surgeons now use posterior (most common) or anterior (growing). Lateral still valuable for complex cases needing both-sided exposure.

Gluteal Region Anatomy

Gluteus Medius

• Origin: Outer surface of ilium between anterior and posterior gluteal lines, gluteal aponeurosis
• Insertion: Lateral and superoposterior surfaces of greater trochanter
• Innervation: Superior gluteal nerve (L4, L5, S1)
• Function: Primary hip abductor, anterior fibers medially rotate and flex, posterior fibers laterally rotate and extend
• Key Point: Anterior 1/3 split in lateral approach - nerve runs in posterior 2/3

Gluteus Minimus

• Origin: Outer surface of ilium between anterior and inferior gluteal lines
• Insertion: Anterior surface of greater trochanter, hip joint capsule
• Innervation: Superior gluteal nerve (L4, L5, S1)
• Function: Hip abduction, medial rotation, stabilizes femoral head in acetabulum
• Key Point: Lies deep to gluteus medius, also split in lateral approach

Superior Gluteal Neurovascular Bundle

• Anatomy: L4-L5-S1 nerve roots, exits pelvis through greater sciatic foramen ABOVE piriformis
• Course: Runs between gluteus medius (superficial) and minimus (deep), courses anteroinferiorly
• Entry Point: Enters gluteus medius 4-5cm proximal to GT apex in POSTERIOR 2/3 of muscle
• Branches: Superior division to medius, inferior division to medius/minimus/TFL
• Clinical: Injury causes complete abductor paralysis with severe Trendelenburg gait

Tensor Fascia Lata (TFL)

• Location: Anterior to gluteus medius, serves as anterior landmark in lateral approach
• Function: Hip flexion, abduction, medial rotation
• Importance: Marks anterior extent of gluteus medius split - don't go anterior to TFL

Surgical Planes

Direct Lateral (Hardinge) Approach

• NOT true internervous plane: Splits ANTERIOR 1/3 of gluteus medius (superior gluteal nerve territory)
• Rationale: Splits muscle IN LINE with fibers, anterior to nerve branches
• Plane: Between anterior and posterior portions of gluteus medius/minimus
• Advantage: Better healing than cutting across fibers, reduces nerve injury risk
• Disadvantage: Still splits single nerve territory - abductor dysfunction risk

Comparison to Other Hip Approaches

Posterior Approach (Moore/Southern):

• True internervous plane between superior gluteal nerve (gluteus medius/minimus) and inferior gluteal nerve (gluteus maximus)
• Better for abductor preservation
• Higher dislocation risk (2-5% vs 0.5-1% lateral)

Anterior Approach (Smith-Petersen/DAA):

• True internervous plane between femoral nerve (sartorius) and superior gluteal nerve (TFL)
• Best for abductor preservation
• Limited femoral exposure, learning curve, LFCN injury risk

Anterolateral Approach (Watson-Jones):

• Between TFL (superior gluteal nerve) and gluteus medius (superior gluteal nerve)
• Not true internervous plane - separates two muscles of same nerve
• Similar abductor dysfunction risk to lateral

Greater Trochanter Osseous Anatomy

• Shape: Quadrilateral prominence on lateral proximal femur
• Insertions: Gluteus medius (superolateral facet), gluteus minimus (anterior facet), piriformis (medial apex), obturator internus/gemelli (medial), obturator externus (trochanteric fossa)
• Blood Supply: Medial femoral circumflex artery (main), lateral femoral circumflex artery (minor)
• Clinical: Detachment/fracture in lateral approach causes abductor failure - repair critical

Hip Joint Capsule

• Attachments: Acetabular rim (outer edge of labrum) to femoral neck (intertrochanteric line anteriorly, above neck posteriorly)
• Ligaments: Iliofemoral (Y-ligament of Bigelow - strongest), pubofemoral, ischiofemoral
• Innervation: Femoral nerve (anterior), obturator nerve (inferior), superior gluteal nerve (superior), nerve to quadratus femoris (posterior)
• Approach: Lateral approach opens anterior and superior capsule after reflecting abductors

Patient Positioning - Lateral Decubitus

Setup:

1. Position: Lateral decubitus, affected hip superior, bottom leg flexed, top leg straight
2. Pelvic Support: Anterior support at pubis/ASIS, posterior support at sacrum/posterior ilium
3. Securing: Beanbag molded around patient OR wide straps across pelvis/chest
4. Padding: Axilla (avoid brachial plexus injury), peroneal nerve at fibular head, down leg at malleolus, pressure points
5. Verification: Pelvis perpendicular (line from ASIS to ASIS should be vertical) - confirm with imaging or alignment device
6. Alternative: Can perform in supine (less common with lateral approach) - patient flat, affected hip at table edge

Step-by-Step Operative Technique

Step 1: Surface Anatomy and Incision Planning

Landmarks:

• Iliac crest: Palpate - guides superior extent
• ASIS: Anterior reference
• Greater trochanter (GT): MOST PROMINENT lateral landmark, center of incision
• Femoral shaft axis: Guides distal extension

Incision:

• Location: Centered over GT (most prominent lateral bony landmark)
• Direction: Longitudinal along femoral shaft axis
• Length: 15-20cm total (5-7cm proximal to GT, 10-12cm distal)
• Position: In lateral decubitus, incision essentially vertical over lateral hip
• Marking: Mark GT, plan straight longitudinal incision

Step 2: Deep Dissection to Fascia Lata

Technique:

1. Incise skin with knife
2. Deepen through subcutaneous tissue with cautery (minimize bleeding)
3. Identify fascia lata/iliotibial band (thick white fascial layer over lateral thigh)
4. Incise fascia lata longitudinally in line with fibers, directly over GT
5. Remove/excise trochanteric bursa (improves visualization)
6. Expose lateral surface of gluteus medius muscle belly (red muscle beneath fascia)

Hemostasis: Careful cautery of subcutaneous vessels, fascia lata relatively avascular

Step 3: Gluteus Medius Split - CRITICAL STEP

Technique:

1. Identify ANTERIOR 1/3 of gluteus medius muscle belly (important - nerve in posterior 2/3)
2. Identify TFL anteriorly (separate muscle anterior to gluteus medius - serves as anterior landmark)
3. Split gluteus medius in line with muscle fibers:
   • Start at GT apex
   • Extend proximally 4-5cm (NO FURTHER - nerve at 4-5cm)
   • Split in ANTERIOR 1/3 (protects nerve in posterior 2/3)
   • Use scissors or knife
   • Split through full thickness to expose gluteus minimus beneath
4. Split gluteus minimus (lies deep to medius, also split in line with fibers)
5. Expose joint capsule beneath minimus

Landmarks:

• TFL anteriorly (don't go into TFL)
• Posterior edge of split should be in ANTERIOR 1/3 of total medius width
• Limit proximal extent to 5cm from GT

Step 4: Abductor Reflection from Greater Trochanter

Technique Options:

Option A - Soft Tissue Reflection (more common):

1. Use cautery or sharp dissection to elevate anterior portion of gluteus medius/minimus from GT
2. Reflect anteriorly and superiorly as CONTINUOUS SLEEVE
3. Include underlying capsule with reflection (muscle-capsule sleeve)
4. Preserve POSTERIOR portion of gluteus medius on GT (provides tissue for repair)

Option B - Bone Wafer Technique:

1. Use thin osteotome to take 2-3mm bone wafer from GT with attached tendons
2. Facilitates anatomic bone-to-bone repair
3. Risk: GT fracture if too much bone removed

Key Points:

• Reflect ANTERIOR 1/3 to 1/2 only (not entire abductor)
• Preserve posterior portion on GT (critical for repair)
• Create muscle-capsule sleeve (easier closure)
• Adequate mobilization for exposure without excessive detachment

Step 5: Capsulotomy and Hip Dislocation

Capsulotomy:

1. Anterior and superior capsule exposed beneath reflected abductors
2. Incise in T-pattern or H-pattern:
   • Longitudinal along superior femoral neck
   • Longitudinal along anterior femoral neck
   • Transverse connecting incision
3. Can excise capsule or preserve for repair (less critical than posterior approach)

Hip Dislocation:

1. Flex, adduct, externally rotate hip
2. Place bone hook around femoral neck
3. Deliver femoral head anteriorly out of wound
4. If tight, may need capsular releases or additional soft tissue releases

Step 6: Femoral Neck Osteotomy

Templating Review:

• Level typically 1cm above lesser trochanter for standard stem
• Adjust for high offset stems, dysplasia, or other factors

Technique:

1. Visualize femoral neck and head
2. Mark osteotomy level with cautery (1cm above lesser trochanter standard)
3. Use oscillating saw perpendicular to anatomic neck axis (NOT shaft axis)
4. Complete cut, remove femoral head with corkscrew extraction device or clamp
5. Send head for:
   • Cultures (always - rule out infection)
   • Histology (confirm diagnosis)
   • Size measurement (guides cup size - typically head OD minus 8-10mm = cup size)

Pearls:

• Lateral approach provides excellent visualization of neck cut (better than anterior)
• Protect posterior wall with retractor during head removal
• Save head for potential bone graft use

Step 7: Acetabular Exposure and Preparation

Retractor Placement (3 retractors around acetabular rim):

1. ANTERIOR retractor: Hohmann over anterior wall/ilium (stay on bone, avoid intrapelvic)
2. SUPERIOR retractor: Hohmann over superior rim
3. INFERIOR retractor: Hohmann over transverse acetabular ligament (watch sciatic nerve)

Soft Tissue:

• Excise labrum circumferentially with cautery
• Remove pulvinar (fat pad) from acetabular fossa with rongeur/curette
• Clear soft tissue to visualize acetabular walls

Identify Transverse Acetabular Ligament (TAL):

• Bridges inferior acetabular rim (anterior to posterior horn)
• Marks true acetabular floor (don't ream through TAL)
• Guides version - parallel to TAL = native anteversion (~20 degrees)

Step 8: Acetabular Reaming

Technique:

1. Starting reamer: 2-4mm smaller than templated size
2. Reaming direction:
   • 40 degrees abduction/inclination (Lewinnek safe zone 30-50°)
   • 20 degrees anteversion (Lewinnek safe zone 10-30°)
   • Use TAL as version guide (parallel = native ~20°)
3. Reaming progression:
   • Ream concentrically to subchondral bone
   • Look for bleeding dot sign (speckled appearance of healthy bleeding bone)
   • Progressive reamer sizes until good rim fit
4. Final reamer: 1-2mm SMALLER than cup (allows press-fit)
5. Avoid: Excessive medial reaming (protrusio, floor weakness)

Assessment:

• 70-80% bone contact needed for biological fixation
• Bleeding bone indicates healthy bed
• Peripheral rim contact important (avoid large central gap)

Step 9: Acetabular Component Insertion

Technique:

1. Cup selection: 1-2mm LARGER than final reamer (interference/press-fit)
2. Positioning: Align inserter to target 40° inclination, 20° anteversion
3. Insertion: Impact with mallet using progressive firm taps
4. Seating: Cup should sit flush with acetabular rim, no toggling
5. Screw fixation (if needed):
   • Indications: Poor bone quality, large cup (greater than 60mm), inadequate press-fit, dysplasia, revision
   • Safe zones: Posterosuperior quadrant (10-2 o'clock right hip, 10-2 o'clock left hip)
   • Avoid: Anteroinferior (iliac vessels), posteroinferior (sciatic nerve)
   • Use depth stops on modern screws

Verification:

• No micromotion or toggling
• Seated flush to rim
• Appropriate inclination/anteversion (use guides/navigation if available)

Step 10: Femoral Canal Preparation

Exposure:

1. Position hip in extension, adduction, external rotation (brings femur into wound)
2. Retract gluteus medius/minimus superiorly
3. May need to release some vastus lateralis from lateral femur for exposure

Canal Opening:

1. Box chisel:
   • Opens canal at anteromedial calcar
   • Removes bone to achieve neutral alignment (corrects varus)
   • Creates space for broach entry
2. Insert progressively to depth without forcing

Broaching:

1. Start 2-3 sizes below templated stem
2. Progressive broaching in neutral version (10-15° anteversion)
3. Broach until cortical chatter (feel/hear endosteal contact = good metaphyseal fit)
4. Broach to full depth (handle 0-5mm proud of cut surface when fully seated)
5. Final broach = final stem size

Step 11: Trial Reduction and Assessment

Trial Components:

1. Insert trial stem (same size as final broach)
2. Insert trial liner into cup (confirm seating with SNAP)
3. Attach trial head (choose size based on leg length/offset needs)

Reduction:

• Gentle traction and manipulation
• Should reduce easily

Assessment - FOUR Parameters:

1. STABILITY (most important in lateral approach):

   • Lateral approach inherently MOST STABLE (lowest dislocation 0.5-1%)
   • Test extension + external rotation (anterior dislocation - rare)
   • Test flexion + adduction + internal rotation (posterior dislocation - rare)
   • Should be very stable in all positions

2. LEG LENGTH:

   • Compare to templating
   • Measure from fixed landmarks (ASIS or iliac crest to medial malleolus)
   • Target: Equal or up to 5mm lengthening acceptable
   • Patient tolerance varies (warn if lengthening planned)

3. OFFSET:

   • Adequate soft tissue tension without excessive tightness
   • Hip should feel stable with appropriate tension
   • Under-tensioning = instability risk
   • Over-tensioning = stiffness, squeaking, femoral fracture risk

4. RANGE OF MOTION:

   • Flexion: 110-120° (full sitting/squatting)
   • Extension: 20-30° (normal gait)
   • Abduction: 45° (clearance)
   • Adduction: 30° (cross legs if desired)
   • Internal/external rotation: 45° each
   • Check for impingement at ROM extremes

Adjustments:

• Change head size (longer neck = more length/offset)
• Change neck length (modular stems)
• Change stem size (up/down if stability or length issue)
• Rarely need to adjust cup in lateral approach (usually stable)

Step 12: Final Component Implantation

Acetabular Liner:

1. Remove trial liner
2. Clean cup taper thoroughly (remove all debris, blood, bone)
3. Insert final liner (usually highly cross-linked polyethylene)
4. Impact until loud SNAP confirms Morse taper engagement
5. Some liners have secondary locking mechanisms - verify engaged
6. Confirm liner fully seated (no gaps, no rotation)

Femoral Stem:

1. Dislocate trial
2. Clean and DRY femoral canal:
   • Suction all blood/fluid
   • Brush canal
   • Pack with gauze and remove (dry surface critical for press-fit)
3. Insert final stem using impactor aligned to target version
4. Impact until seated - typically 1-2mm PROUD of final broach
5. Stem subsides during impaction (final position typically at or slightly below broach level)

Femoral Head:

1. Clean stem trunnion (taper) thoroughly - remove ALL debris
2. Clean head bore thoroughly - remove ALL debris
3. Dry both surfaces (critical for proper Morse taper engagement)
4. Place head on trunnion, align to desired version if modular
5. Impact with FIRM blows:
   • 12mm taper = 5-6 firm impacts
   • Larger heads (36mm+) = 6-8 firm impacts
   • Inadequate impaction = trunnionosis/taper corrosion (major revision cause)
6. Confirm head fully seated (no gap between head and stem)

Step 13: Final Reduction and Stability Check

Reduction:

1. Reduce hip with gentle traction and manipulation
2. Should reduce easily (if difficult, check for component malposition or impingement)

Comprehensive ROM Testing:

• Flexion: 110-120° minimum (functional requirement)
• Extension: 20° (gait requirement)
• Abduction: 45° (clearance for activities)
• Adduction: 30° (crossing legs)
• Internal rotation: 45° (tying shoes)
• External rotation: 45° (gait)

Stability Testing (lateral approach should be very stable):

• Extension + external rotation (tests anterior)
• Flexion + adduction + internal rotation (tests posterior)
• Provocative maneuvers (shuck test, lever-out test)
• Should be rock-solid stable (if unstable, investigate cause)

Leg Length Verification:

• Clinical measurement from fixed landmarks
• Fluoroscopy if available (AP pelvis shows lesser trochanter heights)
• Compare to preoperative plan
• Document if lengthening beyond 5mm (inform patient)

Impingement Check:

• Full ROM without bone-to-bone contact
• No component-to-component contact
• No neck-to-liner impingement

Step 14: Abductor Repair - MOST CRITICAL STEP

Technique - Transosseous Repair:

1. Prepare Greater Trochanter:

   • Remove soft tissue debris
   • Roughen bone surface with rongeur or burr (creates bleeding bed)
   • Creates better healing environment

2. Drill Holes:

   • 3-5 holes using 2.0-2.5mm drill bit
   • From lateral GT cortex
   • Exit anterolateral or superolateral (not medial - weakens GT)
   • Space 10-15mm apart
   • Avoid excessive weakening

3. Suture Selection:

   • Heavy non-absorbable: Ethibond #5 or FiberWire #2
   • High strength essential (repairs fail if sutures break or pull through)

4. Repair Technique:

   • Pass sutures through gluteus medius/minimus tendon/muscle
   • Pass through bone tunnels
   • Position hip in NEUTRAL or slight ABDUCTION (creates appropriate tension)
   • Tie sutures over lateral GT cortex
   • Multiple interrupted sutures (stronger than running)
   • If bone wafer used, reduce wafer anatomically and secure with sutures

5. Modern Techniques (consider if poor tissue):

   • Augmentation with synthetic tape or mesh
   • Suture anchors in GT if osteoporotic bone
   • Double-row repair (like rotator cuff)

6. Test Repair:

   • Should be solid without gapping
   • Sutures should not pull through bone
   • Tissue should not tear with gentle stress
   • If repair feels weak, reinforce

Factors Affecting Healing:

• Bone quality (osteoporosis major issue)
• Tissue quality (elderly patients have attenuated tendons)
• Repair technique (transosseous stronger than soft tissue)
• Postoperative rehabilitation (early active abduction damages repair)
• Patient factors (diabetes, smoking, steroids impair healing)

Step 15: Wound Closure

Irrigation:

• Copious irrigation: 6-9 liters normal saline
• Consider dilute povidone-iodine or antibiotic irrigation
• Remove all debris, bone fragments, cement (if used)

Layered Closure:

1. Gluteus medius split (if any unrepaired portion):

   • Running absorbable suture (1-0 Vicryl)
   • Approximate muscle edges

2. Fascia lata/IT band:

   • Interrupted absorbable sutures (1-0 or 0 Vicryl)
   • Strong layer (important for wound integrity)
   • Avoid excessive tension (lateral hip wounds under tension)

3. Subcutaneous layer:

   • 2-0 or 3-0 absorbable suture
   • Eliminate dead space
   • Careful hemostasis

4. Skin:

   • Staples (traditional, faster) OR
   • Subcuticular absorbable suture (better cosmesis, no removal needed)
   • Skin adhesive/Dermabond

Drainage:

• Consider NO DRAIN (modern practice, reduced infection risk)
• OR single drain for 24 hours if concerned about hematoma
• Exit through separate stab incision (not through main wound)

Dressing:

• Absorbent dressing
• Occlusive barrier (Aquacel, Tegaderm)
• Keep dry for 48 hours minimum

Postoperative Protocol:

• Day 0: Mobilize with physiotherapy (early mobilization reduces complications)
• Weight-bearing: TDWB (toe-down weight-bearing) or WBAT (weight-bearing as tolerated)
  • Depends on bone quality and repair strength
  • Elderly with good repair: WBAT
  • Younger or weak repair: TDWB x 6 weeks
• Precautions: ABDUCTION PRECAUTIONS for 6 weeks
  • NO active abduction (protect repair from being pulled apart)
  • Avoid excessive adduction past midline (stresses repair)
  • May use abduction pillow between legs when sleeping
  • Passive ROM encouraged (prevents stiffness)
  • NO active abduction exercises until 6 weeks
• Discharge: Day 1-2 home with walker/crutches
• DVT prophylaxis: LMWH (enoxaparin 40mg daily) or DOAC (rivaroxaban 10mg daily) for 35 days
• HO prophylaxis: Consider NSAIDs (indomethacin 75mg daily x 6 weeks) - lateral approach has HIGHEST HO rate (15-40%)

Intraoperative Complications

Postoperative Complications

Lateral Approach-Specific Complications

Abductor Dysfunction - The Main Problem:

• Incidence: 20-30% (highest complication rate)
• Mechanism: Splitting/detaching gluteus medius-minimus disrupts structure, repair healing failure
• Presentation: Trendelenburg gait (hip drops on affected side), lateral hip pain, weakness, reduced function
• Impact: Major functional limitation, patient dissatisfaction
• Prevention: Excellent surgical technique, appropriate rehabilitation
• This high rate is why lateral approach has fallen out of favor

Heterotopic Ossification - Highest Rate:

• Incidence: 15-40% (lateral approach highest of all approaches)
• Mechanism: Extensive periosteal stripping, soft tissue trauma
• Brooker Classification: I (islands), II (1cm gap), III (less than 1cm gap), IV (ankylosis)
• Prevention: NSAIDs (indomethacin) or radiation highly effective
• Most asymptomatic (only Brooker III-IV symptomatic)

Greater Trochanter Issues:

• Fracture: 2-5% during surgery or early postop
• Non-union: If bone wafer used, may not heal
• Bursitis: Lateral hip pain from prominent GT
• Impact: Contributes to abductor dysfunction

Postoperative Rehabilitation Protocol

Phase 1: Immediate Postoperative (Days 0-2)

Mobilization:

• Day 0: Sit in chair, stand with walker and physiotherapy
• Day 1: Ambulate with walker, stairs if required for discharge
• Day 2: Ready for discharge if meeting criteria

Weight-Bearing:

• WBAT (weight-bearing as tolerated): Most patients with good bone quality
• TDWB (toe-down weight-bearing): If poor bone quality, weak repair, or surgeon preference
• Walker or crutches x 6 weeks typically

Precautions - ABDUCTION PRECAUTIONS (unique to lateral approach):

• NO active abduction: Protect repair from tensile forces (main precaution)
• Avoid excessive adduction past midline: Don't stress repair
• Abduction pillow: Between legs when sleeping (some surgeons)
• Passive ROM encouraged: Gentle flexion, rotation (prevents stiffness)
• Hip can flex freely: No flexion restrictions (unlike posterior approach)

Pain Management:

• Multimodal analgesia: Regular acetaminophen, NSAIDs (if given for HO prophylaxis), opioids as needed
• Ice: 20 minutes q2-4h
• Elevate when resting

DVT Prophylaxis:

• LMWH (enoxaparin 40mg SC daily) x 35 days OR
• DOAC (rivaroxaban 10mg PO daily) x 35 days
• Early mobilization (most important)
• TED stockings/compression devices

HO Prophylaxis (important in lateral approach):

• Indomethacin 75mg PO daily x 6 weeks (start day 1) - most effective
• Alternative: Single-dose radiation 7-8 Gy within 72 hours (if NSAID contraindicated)

Phase 2: Early Recovery (Weeks 2-6)

Week 2:

• Wound check, suture/staple removal
• Continue abduction precautions
• Progress walking distance
• May wean to single crutch/cane

Weeks 2-6:

• Continue protected weight-bearing if ordered
• NO active abduction exercises (critical - protect repair)
• Passive ROM: Flexion to 90°, gentle rotations
• Strengthening: Hip flexors, quadriceps, hamstrings (NOT abductors yet)
• Cardiovascular: Stationary bike (low resistance)
• Activities: Short walks, light household activities

Week 6 Visit:

• X-rays: AP pelvis, lateral hip (assess component position, rule out complications)
• Clinical exam: Wound healed, ROM assessment, gait evaluation
• BEGIN active abduction if repair appears healed and patient progressing well
• Advance weight-bearing to WBAT if not already

Phase 3: Intermediate Recovery (Weeks 6-12)

Strengthening - Now Include Abductors:

• Progressive abduction exercises: Side-lying abduction, standing abduction with resistance
• Start gentle, progressive resistance
• Gluteus medius focus critical for gait normalization
• Continue hip flexors, extensors, adductors

Functional Training:

• Gait normalization (reduce Trendelenburg if present)
• Balance exercises
• Stair climbing
• Return to normal walking without aids (weeks 8-12 typically)

Activities:

• Resume driving (week 6-8 if right hip, earlier if left)
• Light gardening, shopping
• Swimming (low-impact, excellent)

Phase 4: Late Recovery (Months 3-6)

Advanced Strengthening:

• Progressive resistance training
• Functional movements (squats, lunges if able)
• Sport-specific training if applicable

Return to Activities:

• Month 3: Driving unrestricted, golf, bowling, light sports
• Month 6: Impact sports if strength recovered and surgeon approval
  • Tennis, skiing, hiking
  • Running controversial (most surgeons discourage but some patients do well)

Long-term:

• Continue lifelong low-impact exercise
• Maintain healthy weight
• Annual follow-up with X-rays

Outcomes and Prognosis

Functional Outcomes

Success Rates:

• Overall satisfaction: 85-90% (lower than posterior/anterior approaches)
• Pain relief: Excellent in 90% (similar to other approaches)
• Function: Good in 75-80% (limited by abductor dysfunction in 20-30%)
• Return to activities: Most patients return to low-impact sports and daily activities

Abductor Function:

• Normal strength: 60-70% of patients
• Mild weakness (asymptomatic): 10-15%
• Moderate dysfunction (mild limp): 10-15%
• Severe dysfunction (Trendelenburg gait): 5-10%
• Complete abductor failure: 1-2% (superior gluteal nerve injury)

Gait:

• Normal gait: 70-75%
• Mild limp (compensated): 15-20%
• Obvious limp (Trendelenburg): 5-10%
• Severe limp requiring walking aid: less than 5%

Complication Rates - Comparison to Other Approaches

Survivorship Data (AOANJRR - Australian Data)

Revision Rates:

• 1 year: 1-1.5%
• 5 years: 3-4%
• 10 years: 5-6%
• 15 years: 7-9%

Comparison to Other Approaches:

• Revision rates similar between lateral, posterior, and anterior approaches
• Reasons for revision: Aseptic loosening (most common), dislocation (lower for lateral), infection, periprosthetic fracture, abductor failure (unique to lateral)

Factors Affecting Survival:

• Patient age: Younger higher revision risk (more active)
• Diagnosis: AVN and DDH higher revision than OA
• Component choice: Uncemented cup/stem standard in Australia (best survival)
• Surgeon volume: High-volume surgeons better outcomes
• Bearing surface: Ceramic-on-polyethylene or ceramic-on-ceramic excellent longevity

Patient-Reported Outcomes

Oxford Hip Score: Average 40-42/48 (excellent outcome)

• Pain: Significant improvement in 95%
• Function: Improvement in 85-90% (limited by abductor dysfunction)

EQ-5D: Significant improvement in quality of life

SF-36: Improvement in physical function, bodily pain, general health

Satisfaction: 85-90% satisfied or very satisfied

• Lower than posterior (90-95%) or anterior (90-95%)
• Abductor dysfunction main cause of dissatisfaction

Why Lateral Approach Declining?

Historical Use: Most common approach 1970s-1990s (60-70% of all THAs)

Current Use: Third choice (less than 10% of THAs in most countries)

• Posterior approach: 60-70% (most common)
• Anterior approach: 20-30% (growing)
• Lateral approach: less than 10% (declining)

Reasons for Decline:

1. Abductor dysfunction (20-30%): Main reason - causes persistent pain, limp, weakness
2. High HO rate (15-40%): Requires prophylaxis, can cause stiffness
3. No clear advantage: Dislocation benefit (0.5% vs 2%) offset by abductor problems (20% vs 2%)
4. Better alternatives available: Posterior preserves abductors with similar dislocation rates (if capsular repair). Anterior preserves all muscles.
5. Patient expectations: Modern patients expect full return to activities - abductor dysfunction limiting

Still Useful For:

• Complex cases needing excellent exposure of both acetabulum and femur
• Revision THA (some surgeons prefer for acetabular visualization)
• Surgeons highly experienced with technique (outcomes better with experience)
• Recurrent dislocation (though usually use posterior with repair)