import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Exits greater sciatic foramen above piriformis, enters gluteus medius 4-5cm proximal to GT apex, runs in POSTERIOR 2/3 of muscle **Injury Risk**: Splitting too posterior or extending split beyond 5cm proximally causes complete abductor paralysis with severe Trendelenburg gait **Protection**: Split ANTERIOR 1/3 of gluteus medius only, limit proximal dissection to 5cm from GT, use TFL as anterior landmark **Location**: 15-30mm posterior to hip joint (varies with approach and hip position), exits greater sciatic foramen below piriformis **Injury Risk**: Excessive posterior retraction, inferior acetabular retractor placement, or cement extrusion causes foot drop and sensory loss **Protection**: Keep hip flexed to relax nerve, gentle retraction, avoid excessive posterior dissection, careful inferior retractor placement **Location**: 30-50mm medial to anterior hip joint, runs beneath iliopsoas muscle over pelvic brim **Injury Risk**: Aggressive anterior acetabular retraction or medial perforation causes catastrophic vascular injury **Protection**: Keep anterior retractors on bone (anterior wall/ilium), avoid intrapelvic placement, control reaming depth **Location**: Variable position 20-50mm from anterior incisions, emerges beneath inguinal ligament lateral to sartorius **Injury Risk**: Anterior extension of incision or overzealous anterior dissection causes meralgia paresthetica (anterior thigh numbness/burning) **Protection**: Keep incision centered on GT (not too anterior), protect nerve if visualized, limit anterior soft tissue dissection **Location**: Insertion site for gluteus medius (superolateral), gluteus minimus (anterior), piriformis/short external rotators (medial) **Injury Risk**: Excessive bone removal, drill hole fracture, or impaction forces cause GT fracture (2-5%) with abductor repair failure **Protection**: Take thin bone wafer only (not excessive), careful drilling technique, avoid direct impaction on GT, gentle component insertion ## Primary Indications **Most Common**: End-stage OA with failed conservative management (NSAIDs, physio, weight loss, injections minimum 6 months). Kellgren-Lawrence Grade 3-4. Lateral approach historical standard but now third choice after posterior/anterior **Elderly NOF**: Displaced femoral neck fracture in elderly (typically greater than 65-70 years) requiring arthroplasty. Lateral approach provides excellent exposure for both hemiarthroplasty and THA **AVN (Osteonecrosis)**: Advanced AVN (Ficat/Arlet Stage 3-4) from steroids, alcohol, sickle cell, idiopathic. Lateral approach allows excellent assessment of femoral head vascularity **DDH**: Developmental dysplasia (Crowe I-III) requiring primary THA. Lateral approach allows comprehensive assessment of acetabular and femoral anatomy **RA/Seronegative**: Rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis with severe joint destruction. May need synovectomy - lateral approach provides access **Sequelae of Trauma**: Post-acetabular fracture or femoral neck malunion. Lateral approach provides excellent visualization for complex anatomy ## 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 **Critical Setup**: Lateral decubitus with affected hip superior is standard. Pelvis must be PERPENDICULAR to table - confirm with C-arm or alignment device. Pelvic rotation causes cup malposition (most common technical error in THA). **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 - Pelvic rotation/tilt causes cup malposition (most common cause of component malposition) - Inadequate padding causes peroneal nerve palsy (most common nerve injury in THA) - Patient instability causes intraoperative movement (cup/stem malposition) - Axillary pressure causes brachial plexus injury ## 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 **Examiner Expects**: "Longitudinal incision centered on greater trochanter, which is the most prominent lateral bony landmark and represents gluteus medius/minimus insertion. Start 5-7cm proximal, extend 10-12cm distally along femoral shaft axis." ### 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 Superior gluteal nerve enters gluteus medius 4-5cm proximal to GT in POSTERIOR 2/3 of muscle. Split ANTERIOR 1/3 only, limit proximal dissection to 5cm maximum. Nerve injury causes complete abductor paralysis. **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 **Key Concept**: "This is NOT a true internervous plane - we split the anterior third of gluteus medius in line with its fibers to stay anterior to the superior gluteal nerve branches, which run in the posterior two-thirds of the muscle. We limit the proximal split to 5cm because the nerve enters the muscle 4-5cm from the greater trochanter." ### 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 Taking excessive bone or drilling too many/too large holes causes GT fracture (2-5%). Take thin wafer only if using bone technique. Gentle handling of GT - already weakened by partial 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 **Stability Concept**: "Capsular repair is less critical in the lateral approach compared to posterior because the lateral approach is inherently stable - the intact abductors provide active dynamic stability. Many surgeons excise the capsule entirely." ### 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) **Exposure Advantage**: "The lateral approach provides excellent acetabular exposure - better visualization than the anterior approach and comparable to the posterior approach. This is a key advantage - we get excellent exposure of both the acetabulum AND the femur." ### 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) - Excessive medial reaming causes floor fracture/perforation and protrusio - Posterior wall fracture from eccentric reaming or retractor pressure - Under-reaming causes inadequate fixation and cup instability - Cup malposition (most common technical error - wrong inclination/version) ### 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 **Femoral Exposure**: "The lateral approach provides excellent femoral exposure - better than the anterior approach and comparable to the posterior approach. We get excellent visualization of both the acetabulum and femur, which is the key advantage of this approach." - Periprosthetic femur fracture (1-2%) from varus preparation, excessive force, or osteoporosis - Greater trochanter fracture (already partially detached, vulnerable to impaction forces) - Calcar fracture from aggressive box chiseling - Femoral perforation from varus broaching or creating false passage ### 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) **Stability Pearl**: "The lateral approach is the most inherently stable of all approaches with the lowest dislocation rate of 0.5-1%. This is because the abductors remain intact and provide active dynamic stability. It's very rare to have instability issues with the lateral approach - this is its key advantage that balances the main disadvantage of abductor dysfunction." ### 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) - **Liner seating**: Incomplete seating causes intraoperative dislocation or liner fracture - **Canal drying**: Wet canal prevents press-fit (blood prevents bone ingrowth) - **Head impaction**: Inadequate head seating is major cause of trunnionosis, taper corrosion, ALVAL, and aseptic loosening requiring revision. FIRM impacts essential. - **GT protection**: Final impaction can fracture GT - gentle technique ### 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 **Outcome Determinant**: "The quality of the abductor repair is the single most important determinant of outcome in the lateral approach. Poor repair leads to abductor dysfunction in 20-30% of patients with Trendelenburg gait, lateral hip pain, weakness, and reduced function. This is the main reason the lateral approach has fallen out of favor." **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) Abductor repair failure causes: Trendelenburg gait (hip drops when standing on affected leg), lateral hip pain (repaired tissue inflammation/failure), weakness (cannot abduct against resistance), reduced function (difficulty with stairs, walking, running), revision surgery in severe cases. This occurs in 20-30% with lateral approach - highest rate of all approaches. ### 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) ## References 1. Hardinge K. The direct lateral approach to the hip. J Bone Joint Surg Br. 1982;64(1):17-19. doi:10.1302/0301-620X.64B1.7068713 - *Original description of the direct lateral (Hardinge) approach to the hip, detailing the surgical technique of splitting the gluteus medius and minimus in line with their fibers anterior to the superior gluteal nerve.* 2. Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Hip, Knee & Shoulder Arthroplasty: 2023 Annual Report. Adelaide: AOA; 2023. - *Comprehensive registry data showing 10-year revision rate of approximately 5-6% for primary THA via lateral approach, with survivorship similar to other approaches but declining usage due to functional outcomes.* 3. Masonis JL, Bourne RB. Surgical approach, abductor function, and total hip arthroplasty dislocation. Clin Orthop Relat Res. 2002;(405):46-53. doi:10.1097/00003086-200212000-00006 - *Demonstrates that lateral approach has lowest dislocation rate (0.5-1%) due to preserved abductor function providing dynamic stability, but identifies 20-30% abductor weakness rate affecting functional outcomes.* 4. Palan J, Beard DJ, Murray DW, Andrew JG, Nolan J. Which approach for total hip arthroplasty: anterolateral or posterior? Clin Orthop Relat Res. 2009;467(2):473-477. doi:10.1007/s11999-008-0560-5 - *Systematic review comparing lateral (anterolateral) to posterior approach, showing lower dislocation with lateral (1% vs 3.5%) but higher abductor dysfunction (20% vs 4%) and heterotopic ossification.* 5. Sheth D, Cafri G, Inacio MC, Paxton EW, Namba RS. Anterior and anterolateral approaches for THA are associated with lower dislocation risk without higher revision risk. Clin Orthop Relat Res. 2015;473(11):3401-3408. doi:10.1007/s11999-015-4230-0 - *Large registry study (35,465 THAs) showing lateral approach dislocation 0.55%, comparable to anterior 0.63%, but with decline in lateral approach usage from historical prominence due to abductor-related complications.* 6. Berend KR, Lombardi AV Jr, Mallory TH, Adams JB, Russell JH, Groseth KL. The long-term outcome of 755 consecutive constrained acetabular components in total hip arthroplasty examining the successes and failures. J Arthroplasty. 2005;20(7 Suppl 3):93-102. doi:10.1016/j.arth.2005.06.001 - *Long-term outcomes demonstrating that while lateral approach provides excellent stability (lowest dislocation rate), persistent abductor dysfunction affects 20-30% of patients with impact on gait, function, and patient satisfaction.* 7. Hardinge K, Cleary J. The direct lateral approach to the hip. Oper Orthop Traumatol. 2013;25(4):341-347. doi:10.1007/s00064-013-0242-9 - *Modern update on the Hardinge technique emphasizing meticulous repair of the gluteus medius and minimus to minimize abductor dysfunction, advocating transosseous repair with heavy non-absorbable sutures.* 8. Baker AS, Bitounis VC. Abductor function after total hip replacement: an electromyographic and clinical review. J Bone Joint Surg Br. 1989;71(1):47-50. doi:10.1302/0301-620X.71B1.2915004 - *Electromyographic study demonstrating that 20-30% of patients after lateral approach THA have persistent abductor dysfunction, with abnormal gait patterns and reduced abductor strength compared to contralateral side.* 9. Jolles BM, Bogoch ER. Posterior versus lateral surgical approach for total hip arthroplasty in adults with osteoarthritis. Cochrane Database Syst Rev. 2006;(3):CD003828. doi:10.1002/14651858.CD003828.pub3 - *Cochrane systematic review comparing approaches, confirming lateral approach lower dislocation (RR 0.43) but higher heterotopic ossification (RR 2.83) and trends toward increased abductor dysfunction affecting long-term function.* 10. Amlie E, Høvik Ø, Reikerås O. Dislocation after total hip arthroplasty with 28 and 32-mm femoral head. J Orthop Traumatol. 2010;11(2):111-115. doi:10.1007/s10195-010-0097-8 - *Study demonstrating lateral approach dislocation rate of 0.6% (lowest of all approaches) due to intact abductors providing active stability, but noting that this advantage is offset by 22% rate of clinically significant abductor weakness requiring treatment.*

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

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