Preventing complications in THR

Transcription

1 Preventing complications in THR Dr. (Prof.) Anil Arora MS (Ortho) DNB (Ortho) Dip SIROT (USA) FAPOA (Korea), FIGOF (Germany), FJOA (Japan) Commonwealth Fellow Joint Replacement (Royal National Orthopaedic Hospital, London, UK) Senior Knee and Hip Replacement Surgeon Associate Director Department of Orthopaedics and Joint Replacement Max Superspeciality Hospital, Patparganj, Delhi (India) anilarora@delhiorthojournal.com

2 Common preventable complications DISLOCATION LLD Intraoperative FRACTURES INFECTION NERVE & VASCULAR INJURY DVT Aseptic Loosening

3 Mental Templating

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13 Infection Initial experience Sir John Charnley -8.9 % Wilson 11.0 percent Patterson 8.0 percent Mueller 4.0 percent Current experience Charnley 0.61 percent Lidwell 1.3 percent Fitzgerald 0.51 percent Schutzer 0.38 percent Salvati 1.4 percent

14 Factors thought to influence wound infection Unidirectional airflow Perioperative antibiotic use Previous hip operations Prolonged OR times Post op hematomas Host Co-morbidities

15 Laminar air flow

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17 Pulse lavage system

18 Dislocation 1-3% of cases Doubles with infrequent operator Second most common reason for revision after loosening Krenzel BA, Berend ME, Malinzak RA, Faris PM, Keating EM, Meding JB, Ritter MA. High preoperative range of motion is a significant risk factor for dislocation in primary total hip arthroplasty. J Arthroplasty 2010; 25: 31-35

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20 Dislocation Surgeon factors - Experience (<30 joints) - Approach - Component position - Component design - Soft tissue balance - Impingement Patient factors - Soft tissue - Cognitive disorders - NM disorders - NOF fracture

21 Component Position Acetabular safe zones Abduction.. 40 o +/- 10 o Anteversion 15 +/- 10 o Excessive femoral Anteversion when combined with excessive Acetabular anteversion predisposes to anterior dislocation

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26 COMBINED ANTEVERSION 20 to 30 o IN MEN 30 TO 45 o IN WOMEN Ranawat CS, Maynard MJ. Modern Techniques of Cemented Total Hip Arthroplasty. Techniques Orthop.1991; 6:17-25.

27 COMPONENT DESIGN Increased head size Increases head-neck ratio Reduces impingement / increases arc of motion Increased jump distance Seated deeper in acetabulum Imcreases jump distance Greater translation before dislocation

28 Know the liner Neutral liners v 10 o elevated rim liners - theoretically more stable - reduces dislocation rates early, but not late - can cause impingement in extension and ER - this may lead to dislocation and increased wear - can put hood in variety of positions - usually postero-superior

29 Soft tissue tension Restore LLD and offset - Reduced offset associated with increased dislocation - Reduces ST tension - Increases risk of impingement Dislocations reduced with careful capsular and soft tissue repair in posterior approach

30 Trial Reduction S I.. R. Soft tissue tension/stability Impingement ROM Knees >>>>>>

31 To check tissue tension remove Charnley retractor --Ensure that relaxation (Anesthesia) is adequate

32 Intraoperative maneuvers Shuck test - Distraction of hip joint with in line traction Dropkick test - Hip extended, bend knee to 90 o - If too tight, RF is taut and passively extends the knee Leg to leg comparison - Feel knees when legs is similar positions - Feel tension of abductors

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36 Intraoperative stability 90 degree flexion,. Int. Rotation : Sitting Posture 45 degree flexion, 15 deg adduction, 15 deg IR : Sleeping Posture Extension, External Rotation : Turning Posture:17-22.

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38 Leg Length Discrepancy Complications of LLD 1. Nerve palsy Sciatic nerve - tolerate average 4.4cm lengthening Common peroneal nerve - tolerate average 2.7 cm lengthening 2. Lower back pain / scoliosis 3. Abnormal gait 2-4 cm discrepancy

39 Intraop Measurement Measure Tip of Trochanter to Centre of Head: Restore it The centre of head (stem tip) shall lie at the level of trochanter tip

40 TO ACHIEVE OPTIMUM OFFSET

41 Intraoperative Check on LL

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46 Impingement Osteophytes Component Positioning Liner Excessive capsule

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50 VIDEO

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53 Intraoperative Fractures

54 Acetabular Fractures With press-fit components Especially if under ream Prevention Don't under-ream >1mm Chance increase if under-ream by > 2mm Gentle strokes while hammering

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56 Femoral Fractures Increased incidence with press-fit components..act like splitting wedge Fracture may occur during 1. Dislocating head out of socket 2. Reaming or broaching 3. Hammering the component 5. Rotational force during trial reduction

57 Dislocate femoral head gently bone hook is quite handy

58 Femoral Fractures : Prevention 2. Reaming or broaching 3. Hammering the component 4. Rotational force during trial reduction

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60 DIRECT Laceration - Exposure - Drill reamer - Spike of cement Thermal - Diathermy - Cement NERVE INJURIES INDIRECT Compression - Cerclage wires -Acetabular retractors Haematoma - Post op sciatic nerve palsy Traction - LLD > 4cm - Dislocation

61 Nerve Injury The sciatic, Femoral, Obturator, and Superior gluteal nerves

62 Exposure of the sciatic nerve If anatomy of the hip is distorted the nerve may be displaced from its normal position and may be tethered by scar tissue the dissection must remain close to the femur Careful attention to the placement of retractors.

63 Arterial Injuries Causes as with Neural Injury Femoral, Profunda, Obturator, Iliac Vessls All precautions as for prevention of Neural Injury Screws in safe zone

64 DVT Specific Recommendations THR Enoxaparin 40 mg / day commencing 6-8 hours post op for days Timing o Inconclusive in many areas o Recommend days in - THR Epidural Catheter No anticoagulant within 12 hours of inserting / 6 hours of withdrawing epidural catheter

65 NICE

66 Stem Loosening Causes Failure to remove the soft cancellous bone Failure to provide a cement mantle of adequate thickness around the entire stem; Removal of all trabecular bone from the canal Inadequate quantity of cement and failure to keep the bolus of cement intact to avoid lamination.

67 Stem Loosening Causes Failure to pressurize the cement Failure to prevent stem motion while the cement is hardening. Failure to position the component in a neutral alignment Voids in the cement as a result of poor mixing

68 Cup Loosening Inadequate support of the cup by the surrounding bone and cement Poor Cementation Movement of the cup or cement mantle while the cement is hardening Malpositioning of the cup>>impingement

69 Dislocation Component Position Ranawat concept of combined anteversion Acetabular + Femoral anterversion o for men o for women May wish to increase anteversion in posterior approach and reduce it in the anterior approach

70 All the Best

71 Thank You