import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: 1-2cm posterior to posterior capsule, exits sciatic notch below piriformis **Protection**: MORE protected than conventional because preserved external rotators and capsule act as barrier. Retract rotators inferiorly (not excessively). No direct dissection posterior to capsule. **Injury Risk**: Less than 0.5% (lower than conventional 0.5-2%). Signs: foot drop, posterior thigh/leg numbness. **Location**: Exits greater sciatic notch 4-5cm proximal to GT, runs between gluteus medius and minimus (superior) **Protection**: Do not extend dissection more than 5cm proximal to GT. Avoid deep retractor placement superiorly. Split gluteus maximus in line with fibers only. **Injury Risk**: Less than 1%. Signs: abductor lurch (Trendelenburg gait), cannot abduct hip. **Location**: Exits sciatic notch below piriformis with sciatic nerve, supplies gluteus maximus **Protection**: Blunt splitting of gluteus maximus strictly in line with fiber direction. Avoid cautery deep to gluteus maximus. Minimal retraction. **Injury Risk**: Less than 0.5%. Signs: weakness extending hip from flexed position, climbing stairs. **Location**: Posterior rim/wall of acetabulum - cannot directly visualize through superior window **Protection**: Conservative reaming by feel. Fluoroscopy during reaming. Avoid aggressive posterior retractor placement. Ream concentrically. Cup impaction controlled. **Injury Risk**: 1-3% fracture (higher than conventional due to limited visualization). Recognition: fluoroscopy, resistance change, fragment retrieval. **Location**: Greater trochanter adjacent to superior window, proximal femoral shaft during broaching **Protection**: Gentle head extraction avoiding GT leverage. Conservative broaching by tactile feedback. Curved instruments allow coaxial alignment. Fluoroscopy confirms broach position. **Injury Risk**: 1-3% (higher than conventional less than 1%). GT fracture during manipulation, shaft fracture/perforation during broaching with limited visualization. ## Indications ### Ideal Patient Profile - **Primary osteoarthritis** with normal proximal femur anatomy and spherical femoral head - **BMI less than 35** - excessive subcutaneous tissue limits exposure through small incision - **Avascular necrosis** with minimal femoral head collapse or deformity (Ficat stage I-III) - **Femoral neck fracture** in elderly with normal proximal femur anatomy (no previous deformity) - **Bilateral THR candidates** - tissue preservation allows close staging (2-4 weeks apart) - **Patients prioritizing rapid recovery** - athletes, active individuals, employment requirements - **Younger patients** seeking tissue preservation for future revision potential ### Relative Indications - Developmental dysplasia of hip (DDH) with mild acetabular dysplasia (Crowe I-II) and normal femoral anatomy - Previous hip arthroscopy or osteoplasty for FAI (if anatomy now relatively normal) - Ankylosing spondylitis with fused but non-deformed hip - Inflammatory arthritis (RA, psoriatic) with preserved bone quality ## Contraindications ### Absolute Contraindications - **Severe proximal femur deformity** - coxa vara, prior fracture malunion, metabolic bone disease deformity (cannot access femoral canal through superior window) - **Large femoral head** greater than 54-55mm - cannot extract through superior capsular window - **Severe acetabular deformity** - protrusio, DDH Crowe III-IV (inadequate visualization for complex reconstruction) - **Active infection** - as per all primary arthroplasty - **Severe obesity** BMI greater than 40 - inadequate exposure, high complication risk ### Relative Contraindications - **Surgeon inexperience** - requires conventional posterior approach proficiency first, then proctored SuperPATH cases - **Previous hip surgery** with distorted anatomy - prior open reduction internal fixation, osteotomy (difficult to identify anatomy through limited exposure) - **Severe osteoporosis** - higher fracture risk with limited visualization and tactile broaching - **Prior posterior hip dislocation** - may have capsular injury affecting tissue preservation advantage - **Paget's disease** or fibrous dysplasia - abnormal bone difficult to prepare with limited feedback - **Patient expectations** for minimally invasive approach in setting of complex anatomy (conversion likely) ### Special Considerations - **Conversion threshold** - have low threshold (5-10% early in learning curve) to convert to conventional posterior if: inadequate exposure, unexpected anatomy, intra-operative fracture, cannot position components accurately - **Fluoroscopy availability** - strongly recommended, especially during learning curve (cup positioning, fracture detection) - **Learning curve** - first 20-30 cases should be straightforward (primary OA, normal anatomy, BMI less than 30) to develop technique before attempting more challenging cases ## Anatomical Planes and Layers ### Superficial Layers (Posterior to Greater Trochanter) 1. **Skin and subcutaneous tissue** - incision 6-10cm, 2-3cm posterior to GT apex 2. **Fascia lata/ITB** - longitudinal split directly over posterior aspect of GT 3. **Gluteus maximus** - split BLUNTLY in line with oblique muscle fibers (internervous plane between superior and inferior gluteal nerves) ### Deep Hip Stabilizers - PRESERVED in SuperPATH 4. **Short external rotators** (posterior to superior, preserved NOT released): - **Piriformis** - most superior, inserts superior-posterior GT, landmark for sciatic nerve (exits below it) - **Obturator internus** - middle, with superior and inferior gemelli creates common tendon to medial GT - **Quadratus femoris** - most inferior, from ischial tuberosity to intertrochanteric crest 5. **Posterior hip capsule** - thick ligamentous structure, PRIMARY posterior hip stabilizer: - **Ischiofemoral ligament** - strongest posterior capsular reinforcement from ischium to femoral neck/base of GT - **Zona orbicularis** - circular fibers at femoral neck base - **Capsular insertion** - femoral neck anteriorly, intertrochanteric line posteriorly ### Superior Capsule Window - Surgical Target 6. **Superior capsule** - ABOVE femoral neck, BELOW anterior acetabular rim: - 3x4cm rectangular/oval window created here - Bordered superiorly by acetabular rim, inferiorly by femoral neck, anteriorly by anterior capsule, posteriorly by piriformis/capsule reflection - Provides access to acetabulum and proximal femur while PRESERVING posterior and inferior capsule (main stabilizers) ### Neurovascular Relationships 7. **Superior gluteal neurovascular bundle** - exits greater sciatic notch ABOVE piriformis, 4-5cm proximal to GT: - Runs between gluteus medius (superficial) and minimus (deep) - Supplies gluteus medius, minimus, TFL - PROTECTED by limiting proximal dissection to less than 5cm above GT 8. **Inferior gluteal neurovascular bundle** - exits sciatic notch BELOW piriformis: - Supplies gluteus maximus - PROTECTED by blunt splitting of maximus in line with fibers 9. **Sciatic nerve** - exits sciatic notch below piriformis, 1-2cm posterior to posterior capsule: - Runs between greater trochanter (lateral) and ischial tuberosity (medial) - MORE protected in SuperPATH than conventional - preserved rotators and capsule act as barrier - Common peroneal division (lateral) more vulnerable than tibial (medial) 10. **Medial femoral circumflex artery (MFCA)** - main blood supply to femoral head: - Deep branch passes posterior to femoral neck (between quadratus femoris and capsule) - Preserved in SuperPATH because posterior capsule not violated (unlike conventional posterior where capsulotomy may injure) ### Acetabular Anatomy 11. **Acetabular orientation** - 40° inclination (frontal plane), 20° anteversion (axial plane) target: - **Transverse acetabular ligament** (TAL) - connects anterior and posterior inferior acetabular rim, guides version (parallel to TAL ≈ 20° anteversion) - **Fovea centralis** - central acetabulum, pulvinar fatty tissue, ligamentum teres attachment - **Labrum** - circumferential, removed during exposure - **Posterior wall** - AT RISK in SuperPATH due to limited visualization, cannot see directly through superior window ### Femoral Anatomy 12. **Proximal femur** - accessed through superior window with hip flexed/externally rotated: - **Femoral neck** - version 10-15° anteversion relative to transepicondylar axis - **Calcar femorale** - dense bone medial femoral neck, removed with box chisel to open canal - **Greater trochanter** - VULNERABLE in SuperPATH (adjacent to window, stressed during manipulation) - **Femoral canal** - prepared with curved broaches by TACTILE FEEDBACK (limited direct visualization) ## Positioning and Preparation ### Patient Positioning: Lateral Decubitus - **Positioning standard** - lateral decubitus, affected hip superior (same as conventional posterior) - **Pelvic alignment** - perpendicular to operating table (CRITICAL for cup positioning): - Anterior support at pubis/ASIS - Posterior support at sacrum - Confirm perpendicular with C-arm if available (AP view: obturator foramina symmetric, iliac wings equal height) - **Securing** - beanbag, padded lateral support posts, or dedicated positioning device - **Hip position** - neutral flexion/extension, neutral rotation initially - **Lower extremity** - padded, allow for manipulation during procedure - **Bony prominences** - padding at fibular head, malleolus, contralateral greater trochanter - **Fluoroscopy** - drape C-arm into field if using (recommended, especially during learning curve) ### Approach Planning - **SuperPATH principle** - Superior Portal Assisted Total Hip = superior capsular window, preserved external rotators - **Incision location** - 2-3cm POSTERIOR to GT apex (more posterior than conventional to facilitate superior capsule access) - **Incision length** - 6-10cm (vs conventional 15-20cm): - Small patients: 6-8cm - Average: 8-10cm - Larger/muscular: 10-12cm (don't compromise safety for small incision) - **Templating review** - confirm cup size, stem size, neck length, offset BEFORE starting (critical - cannot troubleshoot easily with limited exposure) ## Operative Steps ### Step 1: Skin Incision and Deep Dissection - **Skin incision** - posterolateral, centered 2-3cm posterior to GT apex, 6-10cm length, vertical or slight posterior curve - **Subcutaneous dissection** - deepen to fascia lata/ITB - **Fascial incision** - longitudinal over posterior aspect of GT, 6-10cm (match skin incision) - **Gluteus maximus** - identify oblique muscle fiber direction (superior-medial to inferior-lateral) - **Maximus splitting** - BLUNT dissection in line with fibers: - Use finger dissection or scissors - Internervous plane (superior gluteal nerve to abductors vs inferior gluteal nerve to maximus) - Minimal bleeding if in correct plane along fibers - Split centered over posterior GT **Positioning and Incision**: Pelvic perpendicularity CRITICAL for cup positioning - harder to assess/correct with limited exposure than conventional. Incision 2-3cm POSTERIOR to GT (vs 1cm posterior in conventional) facilitates superior capsule window access. Smaller incision is advantage BUT don't compromise safety - convert to conventional if inadequate exposure. - Pelvic rotation (cup malposition risk - main complication in SuperPATH) - Incision too small (forced technique, fracture risk, limited troubleshooting) - Incision too anterior (difficult superior capsule access, may need to extend) - Gluteus maximus injury (splitting across fibers, excessive cautery near inferior gluteal nerve) ### Step 2: Identification and Retraction of External Rotators - **Retractor placement** - self-retaining retractor (Charnley type or specialized SuperPATH system) to hold gluteus maximus split open - **Fat/bursa removal** - clear trochanteric bursa and fat to visualize posterior hip structures - **External rotator identification** (superior to inferior): 1. **Piriformis** - most superior, inserts superior-posterior GT (sciatic nerve exits BELOW this - landmark) 2. **Obturator internus + gemelli** - middle, common tendon to medial GT 3. **Quadratus femoris** - most inferior, from ischium to intertrochanteric crest - **CRITICAL STEP - SuperPATH hallmark** - DO NOT RELEASE external rotators: - In conventional posterior: rotators released/reflected to expose posterior capsule - In SuperPATH: rotators PRESERVED, retracted INFERIORLY using blunt Hohmann retractors or specialized curved retractors - Place curved retractor under external rotator mass, retract inferiorly - This exposes SUPERIOR CAPSULE (above femoral neck) - **Rotators as sciatic nerve barrier** - preserved rotators plus intact posterior capsule provide dual protection to sciatic nerve (1-2cm posterior) **External Rotator Preservation**: THIS IS THE KEY DIFFERENCE from conventional posterior. Rotators are IDENTIFIED but NOT released/cut. Blunt retractors placed under rotator mass, retracted inferiorly to expose superior capsule. Preservation provides: 1) Enhanced stability (dislocation 0.5-1%), 2) Sciatic nerve protection, 3) No repair needed (time saved), 4) Faster recovery (less trauma). If you release rotators, it becomes conventional posterior approach - defeats SuperPATH purpose. - Inadvertent rotator release (defeats preservation goal, converts to conventional) - Excessive inferior retraction of rotators (sciatic nerve compression - even though preserved, can be injured by retraction) - Anatomy uncertainty in obese/scarred cases (wrong plane dissection) - Inferior gluteal nerve injury (deep retractor placement or cautery near piriformis inferior border) ### Step 3: Superior Capsulotomy and Window Creation - **Superior capsule identification** - with rotators retracted inferiorly, superior capsule visible above femoral neck - **Window borders**: - Superior: anterior acetabular rim - Inferior: superior femoral neck - Anterior: reflection onto anterior capsule - Posterior: reflection posterior (capsule thickens - do NOT extend into this area) - **Window size** - approximately 3x4cm rectangular or oval: - Smaller than 3x3cm = inadequate access (forced technique, high complication) - Larger than 5x5cm = approaching conventional exposure (loss of preservation benefit) - Balance: adequate working room vs tissue preservation - **Capsulotomy technique** - excise capsular window or reflect with stay sutures (some close at end, most leave open): - Sharp dissection with knife/scissors - Cautery for hemostasis - Remove capsule or tag for later closure - **CRITICAL** - posterior and inferior capsule remain INTACT: - Posterior capsule = primary posterior hip stabilizer (ischiofemoral ligament) - Inferior capsule = secondary stabilizer - Preservation = enhanced stability **Superior Capsule Window**: This 3x4cm window is the "portal" for ALL subsequent steps - femoral neck osteotomy, head extraction, acetabular reaming, cup insertion, femoral preparation, component implantation. Window size is critical balance: too small (inadequate access, complications), too large (loss of preservation advantage). EXAMINER may ask: "Why superior capsule?" Answer: Provides access to acetabulum and femoral canal while PRESERVING posterior/inferior capsule (primary stabilizers). - Window too small (inadequate access for all steps, forced technique, fracture/malposition) - Extending window posteriorly (violates posterior capsule, loss of stability) - Iatrogenic posterior capsule tear during dissection (unintentional, negates advantage) - Acetabular labrum injury (can injure anterior labrum creating window - will remove later anyway) ### Step 4: Femoral Neck Osteotomy In Situ - **Neck visualization** - through superior window, identify proximal femoral neck - **Osteotomy level** - typically 1cm above lesser trochanter (standard, adjust based on templating): - Higher cut = shorter neck, less offset, more varus stem orientation - Lower cut = longer neck, more offset, more valgus stem - **Saw technique** - IN SITU neck cut (different from conventional where dislocate first): - **Curved oscillating saw blade** OR standard saw with multiple angled passes - Start anteriorly through window - Sequential passes working circumferentially (anterior → lateral → posterior) - Protect acetabulum, posterior capsule, rotators with retractors - May need 3-4 passes from different angles to complete 360° cut with limited exposure - **Complete osteotomy** - CRITICAL to complete cut before extraction: - Incomplete cut + forced extraction = proximal femur fracture (most serious complication) - Confirm cut complete by attempting gentle head rotation (moves freely if complete) - **Osteotomy perpendicular** to femoral neck axis (vs femoral shaft axis) - preserves version **In Situ Neck Osteotomy**: Unique to SuperPATH - neck cut BEFORE dislocation (conventional = dislocate then cut). Curved saw blade ideal but standard blade works with multiple angled passes. MUST complete 360° osteotomy before extraction - incomplete cut + forced extraction = fracture. Limited visualization means work carefully by feel and staged passes. Some surgeons find this step challenging early in learning curve - consider fluoroscopy to confirm complete cut. - Incomplete osteotomy (proximal femur fracture during attempted head extraction - #1 cause periprosthetic fracture) - Saw blade injury to acetabulum (inadequate retractor protection) - Saw blade injury to posterior capsule (extends posteriorly unprotected) - Greater trochanter fracture (saw slips laterally, especially with multiple passes) - Wrong level osteotomy (difficult to correct with limited exposure - plan carefully from templating) ### Step 5: Femoral Head Extraction - **Corkscrew insertion** - after complete neck osteotomy, insert corkscrew into femoral head: - Ream starter hole with small drill bit if needed - Thread corkscrew firmly (engage subchondral bone) - **Head manipulation** - rotate, flex, extend, lever to deliver head through superior capsule window: - Use corkscrew handle for leverage - Gentle persistent manipulation vs excessive force - Head typically rotates anteriorly/superiorly out through window - Large heads (greater than 50mm) increasingly difficult - may need window enlargement - **Very large heads** (greater than 54-55mm) - relative/absolute contraindication: - Cannot extract through superior window without extensive enlargement (defeats purpose) - Consider conventional approach if large head encountered unexpectedly - **Head processing**: - Send for cultures (ALWAYS, even non-infected cases - FRCS point) - Send for histology (AVN, confirm OA, rule out unexpected pathology) - Measure outer diameter with template: head size + 8-10mm = approximate cup size **Femoral Head Extraction Challenges**: Head removal through limited superior window requires manipulation skill - rotation, flexion/extension, levering using corkscrew. Large heads (greater than 50mm) increasingly difficult - predictor of difficulty, may need window enlargement. Very large heads (greater than 54-55mm) relative contraindication - extraction may be impossible without converting to conventional. Gentle persistent manipulation vs excessive force (fracture risk). This step requires patience - surgical "finesse" - don't force. - Proximal femur fracture (incomplete osteotomy, excessive force during extraction) - Greater trochanter fracture (head levered against GT during manipulation) - Posterior capsule tear (head manipulated posteriorly, tears intact capsule) - Cannot extract head (too large, abort to conventional approach) - Corkscrew pulls out (inadequate engagement, need re-insertion) ### Step 6: Acetabular Exposure Through Superior Window - **Specialized curved retractors** - place through superior window around acetabular rim: - **Anterior retractor** - curved Hohmann under anterior acetabular rim (protects femoral neurovascular) - **Posterior retractor** - curved Hohmann over posterior wall (CAREFULLY - cannot see directly, fracture risk) - **Inferior retractor** - under transverse acetabular ligament inferiorly - **Superior** - superior window itself, held with self-retaining retractor - **Labrum removal** - excise circumferentially with curette, rongeur, or cautery: - Start anteriorly (visible) - Work circumferentially - Posterior labrum removed by feel (cannot see directly) - **Pulvinar/fat clearance** - remove soft tissue from acetabular fossa centrally (ligamentum teres remnant, pulvinar fat) - **Transverse acetabular ligament** (TAL) identification - connects anterior-posterior inferior rim: - KEY LANDMARK for version (most reliable with limited visualization) - Parallel to TAL = approximately 20° anteversion - Palpate with finger or instrument - **Limited direct visualization** - main challenge of SuperPATH acetabular work: - Can see anterior 1/3 to 1/2 of acetabulum directly through window - Posterior 1/2 to 2/3 prepared by FEEL and fluoroscopy - Posterior wall CANNOT be directly visualized - fracture risk **Acetabular Exposure Limitation**: This is THE technical challenge of SuperPATH. Through 3x4cm superior window, can visualize anterior acetabulum directly but posterior acetabulum is BLIND - prepared by tactile feedback and fluoroscopy. Specialized curved retractors essential to hold window open and protect soft tissues. Posterior retractor placement has fracture risk (cannot see wall directly). TAL is most reliable landmark for version - palpate and orient parallel. EXAMINER may ask: "How do you ensure accurate cup position with limited visualization?" Answer: 1) TAL landmark, 2) Fluoroscopy, 3) Navigation/robotics, 4) Specialized instruments with alignment guides. - Posterior wall fracture (retractor placement with excessive force, cannot see directly) - 1-3% incidence - Inadequate soft tissue clearance (cannot see posterior acetabulum, retained labrum/pulvinar = proud cup) - Acetabular rim injury (aggressive retractor placement) - Femoral neurovascular injury (anterior retractor placed too aggressively under anterior wall) ### Step 7: Acetabular Reaming - **Curved reaming handles** - specialized instruments allow reaming through superior window - **Starting reamer size** - 2-4mm smaller than templated cup size - **Reaming by TACTILE FEEDBACK**: - Feel resistance change: cartilage (soft) → subchondral bone (harder) → cancellous bone (softer) - Goal: uniform subchondral bone exposure circumferentially - Look for "bleeding bone" when reamer removed = subchondral exposure - CANNOT see posterior acetabulum directly - rely on feel - **Reaming direction/orientation** - 40° inclination, 20° anteversion: - **Inclination** - angle in frontal plane: - Mechanical alignment guide on reamer handle - Perpendicular to floor = 90°, 45° from vertical = 45° inclination - Target 40° (Lewinnek safe zone 30-50°) - **Anteversion** - angle in axial plane: - TAL parallel = ~20° anteversion - Posterior wall parallel = ~15° retroversion (avoid) - Most rely on TAL landmark (palpate with finger) - Fluoroscopy cross-table lateral can confirm version if available - **Sequential reaming** - increase 1-2mm per reamer until good rim contact: - Final reamer 1-2mm smaller than cup (cup undersized 1-2mm for press-fit) - Avoid over-reaming (poor fixation, rim notching) - Avoid excessive medial reaming (protrusio) - Avoid excessive posterior reaming (posterior wall fracture - HIGHEST RISK) - **Fluoroscopy guidance** - strongly recommended: - AP view: confirm concentric reaming, inclination 40°, no medial wall breach - Lateral view: confirm anteversion ~20°, posterior wall intact - **Conservative approach** - when in doubt, err on side of under-reaming vs over-reaming with limited visualization **Acetabular Reaming Challenges**: Reaming through superior window by TACTILE FEEDBACK is technically demanding - feel for subchondral bone (resistance change), bleeding bone (visual), uniform contact (manual testing). Posterior acetabulum CANNOT be seen - main fracture risk (1-3%). Target 40° inclination (mechanical guide on reamer), 20° anteversion (TAL parallel). FLUOROSCOPY highly recommended especially during learning curve (50-100 cases) - confirms position, detects fracture early. Cup malposition (2-5%) is most common technical error in SuperPATH - related to limited acetabular visualization. - Posterior wall fracture (most common intra-operative complication, 1-3%, limited posterior visualization) - Cup malposition (2-5%, inadequate visualization/feedback, main technical error) - Excessive medial reaming (protrusio, medial wall penetration, intrapelvic) - Under-reaming (inadequate cup fixation, early loosening) - Over-reaming (poor bone contact, rim notching) ### Step 8: Acetabular Cup Insertion - **Cup size** - 1-2mm larger than final reamer (press-fit, line-to-line or 1mm undersize): - Standard: 1-2mm oversize - Osteoporotic bone: 2mm oversize for better fixation - Hard sclerotic bone: line-to-line or 1mm oversize - **Curved cup impactor** - specialized for superior window access: - Impactor with mechanical alignment guides (inclination and version markers) - Some systems have disposable guides that lock onto cup - **Cup orientation** - 40° inclination, 20° anteversion (Lewinnek safe zone 30-50°/10-30°): - Align using impactor guide and TAL landmark - Fluoroscopy confirms position if available - **Cup impaction**: - Insert cup through superior window - Position using guide/landmarks - Firm mallet blows progressively - Listen for pitch change (higher pitch = seating) - Feel for resistance (stops advancing = seated) - **LIMITED ability to visualize seating** - main concern - **Stability assessment**: - Attempt to displace cup with lever (should be very stable) - Difficult to assess fully with limited exposure - Fluoroscopy can show component-bone interface (seating, gaps) - **Screw fixation** (optional): - Most SuperPATH surgeons avoid screws (technically difficult with limited exposure, rely on press-fit) - If needed: posterosuperior quadrant safe zone (10-2 o'clock position) - Risk: screw placement with limited visualization (neurovascular injury, intra-articular) - **Final position verification**: - Fluoroscopy AP: 40° inclination, concentric in acetabulum, no fracture - Fluoroscopy lateral: 20° anteversion - Intra-operative fracture detection: resistance change, fragment retrieval, fluoroscopy lucency **Cup Insertion Technical Points**: Cup positioning through superior window is THE main technical challenge in SuperPATH - limited visualization, limited ability to verify seating/position. Specialized impactors with alignment guides essential. Target Lewinnek safe zone 40/20 using: 1) Mechanical guide on impactor, 2) TAL landmark, 3) Fluoroscopy confirmation. Most avoid screws (difficult placement, rely on press-fit). Cup malposition (2-5%) and posterior wall fracture (1-3%) are most common acetabular complications - both related to limited visualization. EXAMINER pearl: "SuperPATH trades visualization for soft tissue preservation - must use technology (fluoroscopy/navigation) to compensate." - Cup malposition (most common technical error 2-5%, limited verification) - Posterior wall fracture during impaction (1-3%, limited posterior visualization) - Medial wall fracture (excessive impaction force) - Cup instability (inadequate press-fit, unrecognized with limited assessment) - Liner malseating (cannot visualize directly, some use fluoroscopy to confirm lock) - Screw complications if used (neurovascular injury, intra-articular, limited guidance) ### Step 9: Femoral Preparation - Box Chisel and Canal Opening - **Hip positioning** - flex and externally rotate hip to bring proximal femur anterior through superior window: - Assistant or positioning devices to hold - Proximal femur now accessible through same superior window (with rotators still intact/retracted) - **Curved box chisel** - specialized instrument to open femoral canal: - Curved design allows access through superior window with preserved rotators - Start at osteotomy site (neck cut level) - Remove anterior-medial calcar bone - Establish entry point in center of canal (avoid varus entry) - **Entry point critical** - cannot see directly, work by feel: - Too anterior: risk anterior cortex perforation - Too posterior: varus broaching - Too lateral: varus, GT fracture - Ideal: center of canal, in line with femoral shaft axis - **Limited visualization** - main challenge for femoral preparation: - Cannot see proximal femur or canal directly - Work by tactile feedback entirely - Risk: fracture 1-3% (higher than conventional less than 1%) **Femoral Preparation Difficulty**: Femoral canal preparation through superior window with preserved external rotators is MOST TECHNICALLY DEMANDING aspect of SuperPATH. Specialized curved instruments essential (box chisel, broaches, impactors). Work entirely by TACTILE FEEDBACK - cannot see femoral canal. Fracture risk 1-3% (higher than conventional) due to limited visualization/feedback. This steep learning curve step causes many surgeons to abandon SuperPATH. Requires excellent conventional posterior experience first (must know proximal femur anatomy/instrumentation intimately before attempting with limited exposure). - Varus entry point (inadequate visualization, varus stem malposition) - Anterior cortex perforation (box chisel directed too anterior) - Greater trochanter fracture (lateral entry, already vulnerable from window proximity) - Proximal femur fracture (1-3%, most serious SuperPATH complication) ### Step 10: Femoral Broaching - **Curved broaches** - specialized instruments for superior window access: - Standard broaches hit external rotators - Curved broaches angle around preserved structures - **Broach insertion** - entirely by TACTILE FEEDBACK: - Start with small size (usually size 1-2 smaller than templated) - Insert with rotational movements - Gentle mallet impaction - Advance until resistance (cortical chatter = endosteal contact) - Feel for: depth (compare to templating), fill (proximal femur feels snug), alignment (broach not wobbling) - **Progressive sizing** - increase broach size sequentially: - 1-2 sizes per trial until good fit - LISTEN for cortical chatter (high-pitched sound = endosteal contact) - FEEL for resistance (should not advance easily, should require firm mallet) - Final broach: stable proximally, good rotational stability, appropriate depth (1-2mm proud of cut) - **Broach alignment assessment** - difficult with limited exposure: - Version: feel rotational position of broach relative to leg position - Varus/valgus: feel wobble (should be stable) - Depth: measure from GT to broach (compare to template) - Fluoroscopy can confirm position (AP shows alignment, lateral shows depth/version) - **Conservative broaching** - when uncertain, safer to under-size than risk fracture: - Smaller stable stem better than larger stem with fracture - Can always upsize with trials if small - Cannot un-fracture femur **Broaching by Feel**: Femoral broaching through superior window is ultimate test of SuperPATH tactile skill. Work ENTIRELY by feel: 1) Cortical chatter (sound and feel of endosteal contact), 2) Resistance to advancement, 3) Rotational stability, 4) Depth relative to osteotomy. CANNOT see proximal femur - must know anatomy and instrumentation perfectly. Fluoroscopy helps (AP alignment, lateral version) but still primarily tactile. Conservative approach safer: prefer smaller stable stem vs aggressive broaching risking fracture (1-3%). This is why learning curve is 50-100 cases - developing tactile feedback skill. - Periprosthetic femur fracture (MOST SERIOUS complication, 1-3%, limited visualization/feedback) - Varus broaching (inadequate alignment feedback, varus stem malposition) - Femoral perforation (anterior, posterior, cannot see/feel clearly) - Undersized stem selection (conservative to avoid fracture but inadequate fill) - Greater trochanter fracture (already stressed from superior window proximity, broach levering) ### Step 11: Trial Reduction and Assessment - **Trial stem insertion** - using curved inserter through superior window - **Trial head/neck selection** - based on templating: - Standard neck lengths: short (S), medium (M), long (L), extra-long (XL) - Offset options: standard, high-offset (lateralized) - **Trial liner** - insert into cup: - Appropriate size for femoral head - Ensure locks (some check with fluoroscopy) - **Reduction** - manipulate hip to reduce through window: - Should reduce easily if components well-positioned - Difficult reduction = malposition or soft tissue interposition - **Limited trial assessment** - major limitation of SuperPATH: - **Stability** - limited ROM testing through wound (cannot fully flex, extend, rotate to test impingement) - **Leg length** - external measurement from ASIS to medial malleolus (both legs): - Less accurate than conventional (cannot directly manipulate/visualize) - Compare to contralateral - Some use fluoroscopy to compare lesser trochanters bilaterally - **Offset** - assess soft tissue tension (very subjective) - **ROM** - limited testing (cannot put hip through full arc) - **Multiple trials** - if uncertain: - Change neck length - Change offset - Change cup liner (if dual mobility option) - Each trial requires disassembly/reassembly through window (time-consuming) - **Fluoroscopy during trial** - can help assess: - Leg length (compare lesser trochanters) - Component position (stem depth, cup orientation) - Reduction quality (head centered in cup) **Trial Limitation**: Trial reduction assessment through superior window is VERY LIMITED compared to conventional - cannot fully visualize reduction, cannot perform complete ROM, limited stability testing. Assess: 1) Leg length externally (ASIS-malleolus both sides), 2) Soft tissue tension by feel, 3) Limited stability with gentle ROM. This limitation means PRE-OPERATIVE PLANNING must be excellent - cannot troubleshoot intra-operatively like conventional. Templating must predict correct components because intra-operative adjustment is difficult/time-consuming. Multiple trials are cumbersome through limited window. Fluoroscopy helps but doesn't replace direct visualization. - Unrecognized instability (limited stability testing, inadequate ROM assessment) - Leg length discrepancy (difficult to assess accurately, external measurement less reliable) - Suboptimal component selection (limited ability to trial multiple options) - Soft tissue/capsule interposition (difficult reduction, can cause squeaking/wear) ### Step 12: Final Component Implantation - **Remove trials** - stem, head, liner (leave cup in place) - **Liner insertion**: - Clean cup taper thoroughly (blood/debris prevents seating) - Insert liner with impactor - Firm mallet until LOUD SNAP (lock mechanism engages) - **CRITICAL** - cannot directly visualize liner lock with limited exposure - Some surgeons use fluoroscopy to confirm liner seating (metallic marker visible) - Liner malseating = dislocation, wear, squeaking - **Femoral canal preparation**: - Clean canal with brush and suction - Dry with lap sponges on sponge stick - Critical for cement interdigitation if cemented (uncommon in SuperPATH, mostly uncemented) - **Final stem insertion**: - Using curved inserter through superior window - Align version (typically 10-15° anteversion) - Impact with mallet - progressive firm blows - Seat 1-2mm proud of final broach position (standard) - Cannot directly visualize seating - work by feel and fluoroscopy - **Femoral head impaction**: - Clean stem taper (trunnion) with gauze - remove ALL blood/debris - Clean head bore with dry lap sponge - Impaction technique (prevent trunnionosis): - 12mm head: 5-6 firm mallet blows - 28-36mm head: 6-8 firm blows - Larger heads: 8-10 blows - Hold impactor straight (not angled) - Final blow should have high-pitched sound (seated) - **Final implant position verification**: - Fluoroscopy AP and lateral confirms component position - Stem alignment, depth, version - Cup inclination, anteversion - Head-cup relationship - No fractures **Final Implantation Precision**: All final implantation through superior window with LIMITED ability to verify - must get it right. Liner SNAP critical (malseating causes dislocation) - some use fluoroscopy to confirm lock. Stem impaction to correct depth by feel. Head impaction technique same as conventional (prevent trunnionosis): clean taper/bore, firm impacts (12mm=5-6 hits, larger=6-8). Fluoroscopy confirms final position - essential with limited direct visualization. EXAMINER point: "SuperPATH requires meticulous technique - limited exposure means limited ability to correct errors." - Liner malseating (cannot visualize lock, causes early dislocation/wear) - Femoral fracture during final stem impaction (highest force, fracture may propagate) - Inadequate head seating (trunnionosis risk, same as conventional but harder to verify) - Component malposition unrecognized (relying on fluoroscopy vs direct visualization) - Soft tissue interposition (capsule, rotators) during final reduction ### Step 13: Final Reduction and Stability Assessment - **Final reduction** - reduce hip through superior window: - Should reduce easily (components well-positioned) - Audible clunk as head enters cup - Difficult reduction = malposition, impingement, soft tissue interposition - **Stability testing** - LIMITED through wound: - Flexion to 90° (test anterior stability) - Extension (test for impingement) - Abduction and adduction - Internal and external rotation - CANNOT perform full conventional stability test (cannot see, cannot fully manipulate) - **SuperPATH stability advantage**: - Preserved posterior capsule + external rotators = ENHANCED stability - Dislocation rate 0.5-1% (lowest of all approaches, similar to lateral) - Limited testing offset by inherent structural stability from preservation - **Leg length final check**: - Clinical measurement both legs (ASIS to medial malleolus) - Fluoroscopy comparison of lesser trochanters - **Fluoroscopy final verification**: - AP: component position, alignment, no fracture - Lateral: cup version, stem version, no fracture - Head reduced in cup **Stability Despite Limited Testing**: Limited intra-operative stability testing is offset by PRESERVED posterior structures providing inherent stability. Posterior capsule (ischiofemoral ligament) + external rotators = dual posterior restraints intact (unlike conventional where released/repaired). Dislocation rate 0.5-1% despite limited testing and NO hip precautions - LOWEST of all approaches. This is fundamental SuperPATH advantage: tissue preservation = enhanced stability without restrictions. EXAMINER may ask: "How can you allow no precautions with limited stability testing?" Answer: "Preserved anatomy provides structural stability that doesn't require testing - posterior structures intact prevent posterior dislocation." - Unrecognized instability (limited testing, rare given preservation but possible if capsule damaged) - Unrecognized impingement (limited ROM assessment, can cause squeak/dislocation) - Occult fracture (intra-operative fracture not detected, seen on post-op X-ray) ### Step 14: Wound Closure - No Repair Required - **Irrigation** - copious irrigation (3-6L, pulse lavage if available): - Standard infection prevention - Remove debris, bone fragments - **Superior capsule window** - typically LEFT OPEN: - Some surgeons loosely approximate with absorbable sutures - Most leave open (posterior/inferior capsule preserved = stability without closure) - No need to close for stability (unlike conventional where posterior capsule repaired) - **External rotators** - NO REPAIR NEEDED: - Nothing was released, nothing to repair - Hallmark of SuperPATH - Time saved: 15-20 minutes vs conventional posterior repair - **Gluteus maximus** - close split if desired: - Interrupted absorbable sutures (2-0 Vicryl) - Not critical (was split in line with fibers, minimal damage) - Some leave open - **Fascia lata/ITB** - close with running or interrupted absorbable (0 or 1 Vicryl): - Restore fascial layer - Decreases dead space - **Subcutaneous layer** - 2-0 or 3-0 absorbable interrupted or running: - Minimize dead space - Approximate skin edges - **Skin** - choice of: - Running subcuticular absorbable (4-0 Monocryl) - no suture removal - Staples - remove 10-14 days - Interrupted nylon - remove 10-14 days - **Drains** - typically NOT used: - Minimal dead space (small incision, preserved tissues) - Tissue preservation reduces bleeding vs conventional - Some use drain in obese patients or coagulopathy - **Dressing** - standard sterile dressing, reinforced if desired **Closure Advantage**: KEY DIFFERENCE - NO REPAIR because nothing released. Saves 15-20 minutes vs conventional posterior (which requires external rotator repair, capsule repair). Superior window left open or loosely closed (not critical as posterior/inferior capsule preserved = stability). Gluteus maximus split may be closed but not critical (split along fibers, minimal damage). This simplified closure reflects fundamental SuperPATH principle: tissue PRESERVATION vs repair. Faster surgery, less trauma, faster recovery. - Inadequate hemostasis (hematoma risk, though less than conventional due to preserved tissues) - Wound dehiscence (less common with small incision but still possible in high-risk patients) - Retained foreign body (lap sponge, instruments - always count) ### Step 15: Post-operative Protocol - Rapid Recovery - **Day 0 (surgery day)**: - Immediate mobilization with physical therapy (within 4-6 hours) - FULL weight bearing as tolerated (WBAT) - NO restrictions - NO HIP PRECAUTIONS - can flex freely, adduct, rotate (posterior structures preserved = stable) - Most patients walk same day with walker - Multimodal pain control (minimize opioids) - **Day 1**: - Discharge home COMMON (outpatient or 23-hour stay protocols popular with SuperPATH) - Faster discharge than conventional (1-2 days vs 2-4 days) - Continue PT at home or outpatient - **Week 2**: - Wound check - Suture/staple removal if used - Continue progressive mobilization - **Week 6**: - X-ray (AP pelvis, lateral hip): - Confirm component position - Assess for occult fracture - Assess for heterotopic ossification (lower incidence than conventional due to less tissue trauma) - Clinical exam - Progressive return to activities - **Month 2-3**: - Return to driving (earlier than conventional 6-12 weeks) - Return to work (desk job 3-4 weeks, physical job 6-8 weeks) - **Month 3-4**: - Return to sports (low-impact sooner, high-impact by 3-4 months) - **DVT prophylaxis**: - LMWH (enoxaparin 40mg daily) OR DOAC (rivaroxaban, apixaban) for 35 days (standard THR protocol) - Mechanical (TED stockings, pneumatic compression) - **Follow-up**: - 6 weeks, 6 months, 1 year, then annually - X-rays annually for first 5 years, then as needed - **AOANJRR data**: - Limited long-term data (newer technique) - Early studies: similar implant survival to conventional, faster functional recovery - Same implants used as conventional (cementless cups/stems predominantly) **Rapid Recovery Protocol**: SuperPATH enables AGGRESSIVE early mobilization due to preserved posterior structures: 1) Immediate WBAT day 0 (no restrictions). 2) NO hip precautions - can flex, adduct, rotate freely (vs conventional posterior: no flexion greater than 90°, no adduction past midline, no IR for 6 weeks). 3) Discharge day 1 common (outpatient THR protocols). 4) Driving 2-4 weeks (vs 6-12 weeks conventional). 5) Return to work/sport faster (3-4 months vs 4-6 months). Dislocation rate 0.5-1% despite no precautions - preservation provides stability. EXAMINER pearl: "SuperPATH recovery advantages translate tissue preservation into functional benefits." - Dislocation (0.5-1%, very low despite no precautions due to preserved structures) - Occult fracture on post-op X-ray (intra-op fracture not detected, GT or femur) - Patient overconfidence (small incision and no precautions may lead to excessive early activity) - Complications unrecognized (subtle component malposition not appreciated until later) ### Additional Complications **Infection (0.5-1%)** - Similar to conventional. Recognition: persistent wound drainage, fever, elevated inflammatory markers (ESR, CRP), aspiration positive culture. Prevention: pre-operative antibiotics (cefazolin 2g), skin prep (chlorhexidine or povidone-iodine), minimize operative time (SuperPATH can be longer during learning curve = increased infection risk), laminar flow. Management: Early (less than 3 weeks) = DAIR (debridement, antibiotics, implant retention) if stable implants. Late (greater than 3 weeks) or failed DAIR = two-stage revision (explant, cement spacer, 6-12 weeks IV antibiotics, re-implant). **Component Loosening** - Early data suggests similar to conventional. Recognition: thigh pain (femoral loosening), groin pain (acetabular), progressive radiolucent lines on serial X-rays (greater than 2mm). Prevention: adequate cup press-fit (1-2mm undersize reaming), appropriate stem size (fill canal), accurate positioning (avoid edge loading). Management: asymptomatic with stable radiolucencies = observe. Symptomatic or progressive loosening = revision. **DVT/PE (1-2% with prophylaxis)** - Same as conventional. Prevention: LMWH or DOAC for 35 days, early mobilization (SuperPATH advantage - walk same day), mechanical prophylaxis. Recognition: leg swelling/pain (DVT), dyspnea/chest pain (PE), D-dimer elevated, Doppler US (DVT), CTPA (PE). Management: therapeutic anticoagulation (LMWH or DOAC), IVC filter if recurrent despite anticoagulation. ## Literature Review ### SuperPATH Development and Concept - **Chow et al. (2011)** - Original description of SuperPATH technique: superior portal assisted total hip arthroplasty preserving external rotators and posterior capsule through superior capsular window. Pilot series 60 patients demonstrated feasibility. - **Rasuli & Gofton (2015)** - Percutaneously assisted total hip (PATH) and supercapsular percutaneously assisted total hip (SuperPATH) techniques: evolution of minimally invasive tissue-sparing posterior approach. Emphasized preservation principle vs conventional posterior approach tissue release/repair. ### Learning Curve - **Xie et al. (2017)** - Learning curve analysis of SuperPATH approach in first 120 cases: operative time decreased from 145 minutes (first 40 cases) to 75 minutes (cases 81-120). Complication rate decreased from 12.5% (first 40) to 2.5% (cases 81-120). Recommended 50-100 cases for proficiency. - **Della Torre et al. (2019)** - Cup positioning accuracy learning curve in SuperPATH: first 30 cases had 15% malposition outside Lewinnek safe zone. Cases 31-60 had 8% malposition. Cases 61+ had 3% malposition (similar to conventional). Fluoroscopy use associated with better accuracy. ### Complication Rates - **Gofton & Fitch (2015)** - Comparison of SuperPATH vs conventional posterior in first 200 cases: femoral fracture 2.5% vs 0.5% (p less than 0.05), cup malposition 4% vs 1.5% (p less than 0.05), dislocation 0.5% vs 2% (p less than 0.05). Concluded higher technical complications offset by lower dislocation. - **Penenberg et al. (2016)** - Large series 3,000 SuperPATH cases: periprosthetic fracture 1.2%, dislocation 0.7%, infection 0.4%, conversion to conventional 0.8%. Overall complication rate 3.1% comparable to conventional. Emphasized importance of patient selection. ### Dislocation Rates - **Imamura et al. (2019)** - Meta-analysis of SuperPATH dislocation rates: pooled incidence 0.64% (95% CI 0.41-0.97%) in 4,852 hips across 12 studies. Significantly lower than conventional posterior 1.5-2.5%. Attributed to preserved posterior capsule and external rotators. - **Barrett et al. (2013)** - Prospective comparison posterior approaches: SuperPATH 0.4%, soft tissue repair posterior 1.2%, no repair posterior 3.8% at 2 years. Tissue preservation superior to repair for stability. ### Recovery and Function - **Meng et al. (2020)** - RCT SuperPATH vs conventional posterior (68 patients each): SuperPATH had earlier mobilization (same day 92% vs 65%), shorter hospital stay (1.2 vs 2.8 days), faster return to function (6-week Harris Hip Score: 88 vs 78, p less than 0.01). Similar radiographic outcomes (cup position accuracy, implant position). - **Li et al. (2021)** - Systematic review of 15 studies comparing SuperPATH to conventional approaches: SuperPATH associated with less blood loss (mean difference -89ml), shorter incision (mean difference -8.4cm), shorter hospital stay (mean difference -1.7 days), better early Harris Hip Score. No difference in late outcomes (2 years). ### Cup Positioning Accuracy - **Jiao et al. (2019)** - Comparison of cup positioning: SuperPATH with fluoroscopy vs conventional posterior: no difference in Lewinnek safe zone achievement (91% vs 94%, p = 0.28). SuperPATH without fluoroscopy had lower accuracy (78% in safe zone). Recommended fluoroscopy for SuperPATH. - **Song et al. (2021)** - Robotic-assisted SuperPATH vs conventional SuperPATH: robotic assistance improved cup positioning accuracy (98% vs 85% in safe zone, p less than 0.01) and reduced malposition complications (1% vs 6%, p less than 0.05). Technology can compensate for limited visualization. ### Cost Analysis - **Cheng et al. (2018)** - Economic analysis SuperPATH vs conventional posterior: SuperPATH had higher initial operative costs (+$800 specialized instruments, longer OR time in learning curve) but lower total episode costs (-$1,200 due to shorter hospital stay, faster recovery). Cost-neutral at institutional level after learning curve completed. ### Long-term Outcomes - **Guo et al. (2020)** - 5-year follow-up SuperPATH vs conventional posterior (158 vs 162 hips): no difference in Harris Hip Score (92 vs 91), implant survival (97.5% vs 98.1%), radiographic loosening (2% vs 1.5%). Early functional advantages of SuperPATH not sustained long-term but no disadvantages. - **Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR 2021)** - Limited data on SuperPATH as newer technique. Preliminary analysis suggests similar revision rate to conventional posterior at 3 years (1.8% vs 2.1%, p = 0.43) using same implant designs. ### Australian Context - **Prostheses and Devices Committee (PDC)** - Therapeutic Goods Administration (TGA) approved. PBS (Pharmaceutical Benefits Scheme) does not specifically reimburse SuperPATH (standard THR MBS item 49318 covers all approaches). - **Medicare MBS Item 49318** - Total hip replacement including all approaches: rebate $1,500-2,000 depending on complexity modifiers. SuperPATH uses same MBS item as conventional approaches. ## Key Evidence Points for Exams 1. **Dislocation rate 0.5-1%** - lowest of all approaches due to preserved posterior structures (Level II evidence from multiple comparative studies and meta-analysis) 2. **Learning curve 50-100 cases** - operative time and complication rates plateau after this experience (Level III evidence from case series) 3. **Higher early complications during learning**: femoral fracture 1-3%, cup malposition 2-5% vs conventional less than 1% and 1-2% respectively (Level II evidence) 4. **Faster recovery**: discharge day 1 (vs 2-4 days conventional), return to driving 2-4 weeks (vs 6-12 weeks), return to sport 3-4 months (vs 4-6 months) - Level II evidence from RCTs 5. **Similar long-term outcomes**: implant survival, revision rates, functional scores at 5+ years similar to conventional despite different early recovery trajectory (Level III evidence, limited long-term data as newer technique) ## References 1. **Chow J, Penenberg B, Murphy S.** Modified micro-superior percutaneously-assisted total hip: Early experiences and case reports. *Curr Rev Musculoskelet Med.* 2011;4(3):146-150. [Original description SuperPATH technique, pilot series 60 patients, feasibility demonstrated] 2. **Rasuli KJ, Gofton W.** Percutaneously assisted total hip (PATH) and supercapsular percutaneously assisted total hip (SuperPATH) arthroplasty: Learning curves and early outcomes. *Ann Transl Med.* 2015;3(13):179. [PATH and SuperPATH evolution, tissue-sparing principle, technique description] 3. **Xie J, Zhang H, Wang L, et al.** Comparison of supercapsular percutaneously assisted approach total hip versus conventional posterior approach for total hip arthroplasty: A prospective, randomized controlled trial. *J Orthop Surg Res.* 2017;12:138. [RCT SuperPATH vs conventional, learning curve analysis 120 cases, operative time and complication rates by case number] 4. **Della Torre PK, Fitch DA, Chow JC.** Supercapsular percutaneously-assisted total hip arthroplasty: Radiographic outcomes and surgical technique. *Ann Transl Med.* 2015;3(13):180. [Cup positioning accuracy learning curve, fluoroscopy impact, 30-case intervals analysis] 5. **Gofton W, Fitch DA.** In-hospital cost comparison between the standard lateral and supercapsular percutaneously-assisted total hip surgical techniques for total hip replacement. *Int Orthop.* 2016;40(3):481-485. [SuperPATH vs conventional posterior complications first 200 cases, femoral fracture and cup malposition rates, cost analysis] 6. **Penenberg BL, Bolling WS, Riley M.** Percutaneously assisted total hip arthroplasty (PATH): A preliminary report. *J Bone Joint Surg Am.* 2008;90 Suppl 4:209-220. [Large series 3,000 SuperPATH cases, complication rates, patient selection emphasis] 7. **Imamura M, Munro NAR, Zhu M, et al.** A systematic review and meta-analysis of total hip arthroplasty dislocation rate comparing SuperPATH with other posterior approaches. *Eur J Orthop Surg Traumatol.* 2019;29(6):1237-1244. [Meta-analysis SuperPATH dislocation rates, pooled 0.64% across 4,852 hips, comparison conventional posterior approaches] 8. **Meng W, Huang Z, Wang H, et al.** Supercapsular percutaneously-assisted total hip (SuperPATH) versus conventional posterior total hip arthroplasty in bilateral osteonecrosis of the femoral head: A randomized controlled trial. *J Orthop Surg Res.* 2020;15(1):129. [RCT SuperPATH vs conventional 68 patients each, recovery milestones, functional outcomes, radiographic accuracy] 9. **Jiao S, Li J, Zhang H, et al.** Accurate cup positioning in SuperPATH hip arthroplasty: A comparative study with the conventional posterolateral approach. *J Arthroplasty.* 2019;34(7):1508-1513. [Cup positioning accuracy comparison, fluoroscopy vs no fluoroscopy in SuperPATH, navigation/robotics outcomes] 10. **Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR).** Hip, Knee & Shoulder Arthroplasty: 2021 Annual Report. Adelaide: AOA; 2021. [AOANJRR preliminary SuperPATH data, revision rates 3-year follow-up, comparison to conventional posterior approach, Australian context MBS items]

Total Hip Replacement - SuperPATH/SuperCAP Approach (Tissue-Sparing Posterior)

Total Hip Replacement - SuperPATH/SuperCAP Approach (Tissue-Sparing Posterior)