Total hip arthroplasty By:S.Azarsina MD Alborz university of medical sciences

• Total hip arthroplasty is the most commonly performed adult reconstructive hip procedure

• Total hip arthroplasty is the most commonly performed adult reconstructive hip procedure • Total hip components must withstand many years of cyclic loading equal to at least 3-5 times the body weight – at times they can be subjected to overloads of 1012 times the body weight

• An awareness of the history of hip arthroplasty is necessary to appreciate not only its current status, but also its future

• An awareness of the history of hip arthroplasty is necessary to appreciate not only its current status, but also its future • The use of biological and inorganic materials for hip arthroplasty became popular in the early 20th century

• Deformed or ankylosed joint surfaces were contoured, and an interpositional layer was inserted to resurface the joint and allow motion

• Deformed or ankylosed joint surfaces were contoured, and an interpositional layer was inserted to resurface the joint and allow motion • Fascia lata grafts and periarticular soft tissues were used extensively in the US and Europe

• Deformed or ankylosed joint surfaces were contoured, and an interpositional layer was inserted to resurface the joint and allow motion • Fascia lata grafts and periarticular soft tissues were used extensively in the US and Europe • Jones used gold foil as an interpositional layer in 1912

• Deformed or ankylosed joint surfaces were contoured, and an interpositional layer was inserted to resurface the joint and allow motion • Fascia lata grafts and periarticular soft tissues were used extensively in the US and Europe • Jones used gold foil as an interpositional layer in 1912 • Results remained unpredictable, with residual pain and stiffness being the primary causes of failure

• In 1923 Smith-Petersen introduced the concept of "mould arthroplasty" as an alternative to the interpositional membrane

• In 1923 Smith-Petersen introduced the concept of "mould arthroplasty" as an alternative to the interpositional membrane • The procedure was intended to restore congruous articular surfaces by exposing bleeding cancellous bone of the femoral head and acetabulum, with subsequent metaplasia of the fibrin clot to fibrocartilage under the influence of gentle motion

• Glass was chosen as the material for the first mold, after Smith-Petersen discovered a smooth synovial membrane surrounding a glass foreign body removed from a patient's back

• Glass was chosen as the material for the first mold, after Smith-Petersen discovered a smooth synovial membrane surrounding a glass foreign body removed from a patient's back • Although all the glass molds implanted broke within a few months, the initial results were encouraging and prompted a search for more durable materials

• After the development of Vitallium by Venable and Stuck in 1937, implants of sufficient durability became available

• After the development of Vitallium by Venable and Stuck in 1937, implants of sufficient durability became available • The Smith-Petersen cup arthroplasty with subsequent modifications by Aufranc became the standard for hip reconstruction until the advent of modern-day total hip arthroplasty

• Total hip arthroplasty evolved as a result of many improvements in design of a femoral head prosthesis, the availability of suitable component materials and manufacturing techniques, a better understanding of hip mechanics,and the need for resurfacing the acetabulum

• Charnley did pioneering work in all aspects of total hip arthroplasty including – surgical alteration of hip biomechanics – Lubrication – Materials – Design – operating room environment

• A major advancement was his use of coldcuring acrylic cement(polymethyl methacrylate [PMMA]) for fixation of the components

• A major advancement was his use of coldcuring acrylic cement(polymethyl methacrylate [PMMA]) for fixation of the components • His periodic reviews and those of other investigators of the results in numerous patients have been invaluable, especially concerning wear, infection, loosening, and stem failure

• It immediately became apparent,however, that success depended on careful selection and evaluation of patients and on meticulous attention to operative technique and asepsis

• the history of hip arthroplasty has been dynamic, and research continues to improve results,especially in young patients

• the history of hip arthroplasty has been dynamic, and research continues to improve results,especially in young patients • Investigation has proceeded along multiple paths, including – improvement in the durability of implant fixation – reduction in the wear of the articulating surfaces – technical modifications in the operation to speed rehabilitation and reduce implant positioning errors

• In response to the problem of loosening of the stem and cup based on the alleged failure of cement, press-fit,porous-coated, and hydroxyapatite-coated stems and cups have been investigated as ways to eliminate the use of cement and to use bone ingrowth as a means of achieving durable skeletal fixation

• As technological advances improve the longevity of implant fixation, problems related to wear of articulating surfaces have emerged

• As technological advances improve the longevity of implant fixation, problems related to wear of articulating surfaces have emerged • Ceramic-ceramic and metal-metal articulations are being evaluated because of their low coefficient of friction and superior wear characteristics

• As technological advances improve the longevity of implant fixation, problems related to wear of articulating surfaces have emerged • Ceramic-ceramic and metal-metal articulations are being evaluated because of their low coefficient of friction and superior wear characteristics • Highly cross-linked polyethylene has likewise been a topic of intensive investigation

• The results of revision procedures are less satisfactory, and primary total hip arthroplasty offers the best chance of success

• The results of revision procedures are less satisfactory, and primary total hip arthroplasty offers the best chance of success • Selection of the appropriate patient, the proper implants, and the technical performance of the operation are of paramount importance

• Total hip arthroplasty procedures require the surgeon to – be familiar with the many technical details of the operation to contend successfully with the many problems that occur

• to evaluate new concepts and implants, a working knowledge of biomechanical principles, materials, and design also is necessary

• A basic knowledge of the biomechanics of the hip and of THA is necessary to – perform the procedure properly – manage the problems that may arise during and after surgery successfully – select the components intelligently – counsel patients concerning their physical activities

biomechanics

DESIGN AND SELECTION OF TOTAL HIP COMPONENTS

DESIGN AND SELECTION OF TOTAL HIP COMPONENTS • No implant design or system is appropriate for every patient, and a general knowledge of the variety of component designs and their strengths and weaknesses is an asset to the surgeon

• Selection is based on the – patient's needs – patient's anticipated longevity and level of activity – bone quality and dimensions – the ready availability of implants and proper instrumentation – Experience of the surgeon

Femoral components • Cemented • Porous coated cementless • Press-fit cementless

Acetabular components • Cemented • Cementless(metal on poly) • Alternative bearings – Highly cross-linked polyethylene – Metal on metal – Ceramic on ceramic

Cage • Pelvic discontinuity • Severe segmental and cavitary defects • Destruction by tumors • Radiation necrosis(incompetent bone)

• Osteolysis secondary to polyethylene particulate debris has emerged as the most notable factor endangering the long-term survivorship of total hip replacements

• Osteolysis secondary to polyethylene particulate debris has emerged as the most notable factor endangering the long-term survivorship of total hip replacements • Several alternative bearings have been advocated to diminish this problem, particularly in younger, more active patients

Indications for THR • Originally, the primary indication for total hip arthroplasty was the alleviation of incapacitating arthritic pain in patients older than 65 years whose pain could not be relieved sufficiently by nonsurgical means and for whom the only surgical alternative was resection of the hip joint (Girdlestone resection arthroplasty) • Of secondary importance was the improved function of the hip

• Historically, patients 60 to 75 years old were considered the most suitable candidates for total hip arthroplasty, but since the 1990s this age range has expanded • With an aging population, many older individuals are becoming candidates for surgery • In a review of 99 procedures in patients 80 years old and older, Brander et al. found that complication rates and length of hospital stay were not significantly different from a control group of younger individuals, and functional gains were similar

• Advanced age in itself is not a contraindication to surgery – poor outcomes seem to be related more to comorbidities than to age alone

• The 1994 National Institutes of Health Consensus Statement on Total Hip Replacement concluded that "THR is an option for nearly all patients with diseases of the hip that cause chronic discomfort and significant functional impairment

• Before any major reconstruction of the hip is recommended, conservative measures should be advised – weight loss, analgesics,restriction of activity,cane

• These measures often relieve the symptoms enough to make an operation unnecessary or at least delay the need for surgery for a significant period • When surgery is anticipated in a young individual with a physically demanding occupation, consideration should be given preopcratively to job retraining in a more sedentary vocation

• Surgery is justified if, despite these measures, pain at night and pain with motion and weight bearing are severe enough to prevent the patient from working or from carrying out activities of daily living

THA indications • Only Pain! • patients with limitation of motion, limp, or leg-length inequality but with little or no hip pain are not candidates for total hip arthroplasty

• Total hip arthroplasty is a major surgical procedure associated with a significant number of complications and a mortality rate of I% to 2% • Consequently, when total hip arthroplasty seems indicatcd, patients must be evaluated carefully, especially for systemic disorders and for general debility that may contraindicate an elective major operation

Contraindications • Absolute – Active infection(of any region) – Unstable medical illness

• Relative – any process that is rapidly destroying bone – neuropathic arthropathy – insufficiency of the abductor musculature – rapidly progressive neurological diseases

Bilateral THR • The major indication is a medically fit patient with bilateral severe involvement with stiffness or fixed flexion deformity – because rehabilitation may be difficult if surgery is done on one side only

• No increase in local or general complications

Pre-op templating goals • Implant selection – For best femoral fit – Anatomical COR

• Reduce operation time • Neck osteotomy level • Neck lenghth to avoid LLD

Preparation and draping • Position – Supine/lateral

• Positioning devices should be placed so as not to impede the motion of the hip intraoperatively, or assessing stability is difficult • positioning devices should be placed against the pubic symphysis or the ASIS so that no pressure is applied over the femoral triangles, or limb ischemia or compression neuropathy may result

Surgical approaches • Posterolateral • Lateral • Anterior

Posterolateral approach

• Ant.sup – Ext-iliac vessels

• Ant.inf – Obturator vessels and nerve

• Post.inf – Sciatic N. – Sup.gluteal vessels

Cemented cup implantation

Cemented cup implantation • 3mm peripheral cement mantle – Ream equal to cup size+6 mm

• If any motion is detected or blood or small bubbles extrude from the interface, the component is loose and must be removed and replaced

Cementless cup insertion • Component diameter must be 1-2 mm larger to pressfit • Larger component causes polar gap and acetabular fx

Cementless femoral component • The best candidate is a young patient with good bone stock • Insert the smallest reamer at a point corresponding to the piriformis fossa – The insertion point is slightly posterior and lateral on the cut surface of the femoral neck – An aberrant insertion point does not allow access to the center of the medullary canal

• After the point of the reamer has been inserted, direct the handle laterally toward the GT – Aim the reamer down the femur toward the medial femoral condyle

• If this cannot be accomplished, remove additional bone from the medial aspect of the GT or varus positioning of the femoral component results

• The hip should be stable in – full extension with 40 degrees of external rotation – 90 degrees flexion with at least 45 degrees of internal rotation – 40 degrees flexion with adduction and axial loading (the so-called position of sleep)

• If the hip dislocates easily, and the head can be manually distracted from the socket more than a few millimeters (the so-called shuck test), use a longer neck length

Cemented femoral component • Indication – Physiologic age > 65 – Osteoporotic and thin femoral cortex

• Cement mantle thickness – 4mm proximal – 2mm distal

• Irrigate the canal before cementing – Better cement quality and fixation – Reduce fat emboli

Wound closure • Abduct the leg while closure of facia lata • Tight closure of fascia helps hip stability and prevents superficial inflammations become deep • Put 2 drains deep and superficial to fascia lata

Complications • • • • • • • •

Loosening Infection Dislocation Nerve injury LLD HO Hematoma DVT

Revision THR • In 2002, 17.5% of all hip arthroplasties performed in the US were revision procedures • In many patients, failure of total hip arthroplasty can be traced to one or more technical problems that occurred at the time of the primary procedure • A well-done index procedure provides the patient with the best opportunity for longterm success

• Revision of THR usually is much more difficult, and the results typically are not as satisfactory as after a primary THR • Revision requires more operative time and more blood loss, and the incidences of complicatins is highier – infection, thromboembolism, dislocation, nerve palsy,femur fx

• The complexities of revision surgery underscore the importance of technical precision in primary arthroplasties

• Cementless devices have better results in revision surgeries • We encounter bone deficiencies in revision surgeries – Better results with bone grafting rather than cement filling – No bone ingrowth potenial – Use implants with more extensive porous coatings

Indications • Pain is the major indication for revising a THR • Other indications – – – – – –

painful, aseptic loosening of one or both components progressive loss of bone fx or mechanical failure of the implant recurrent or irreducible dislocation infected THR as a one-stage or two-stage procedure periprosthetic fracture

Approach • The transtrochanteric approach provides the best exposure of the femur and the acetabulum and is the approach of choice for most complex revision procedures

Post-op care • There is no universally accepted postoperative rehabilitation program after THR • a well-constructed rehabilitation program speeds the recovery of motion and function, diminishes limp, and aids in a return to independent living

• In the immediate postop,the hip is positioned in 15 degrees of abduction while the patient is recovering from the anesthetic • We use a triangular pillow to maintain abduction and prevent extremes of flexion

• On the first or second postop day, the patient can sit on the side of the bed or in a chair in a semirecumbent position • One or two pillows in the seat of the chair helps prevent excessive flexion • An additional pillow between the thighs limits adduction and internal rotation • Because extended periods of sitting are uncomfortable and promote flexion contracture, sitting should be limited to half-hour increments

• Gait training usually can begin on the first postoperative day • Most elderly patients require a walker for balance and stability • Many younger patients require a walker for only a few days and progress to crutches

• If the components were cemented, early weight bearing to tolerance is permitted • With cementless, porous ingrowth implants, many authors recommend limited weight bearing for 6 to 8 weeks

• Gait training is preferably conducted on the hospital ward • Sending patients to the physical therapy department in a wheelchair often leaves them tired and uncomfortable before the exercise session begins

• When the patient is able to walk far enough to reach the bathroom with supervision, bathroom privileges with an elevated toilet seat are allowed

• A few periods of instruction by an occupational therapist are valuable. Patients who live alone can return to independent living sooner if they are able to dress, put on shoes,pick up objects from the floor, and carry out other activities of daily living in a safe manner • Many simple appliances are available to assist in these activities

• The patient can be discharged from the hospital when able to get in and out of bed independently, walk over level surfaces, and climb a few steps • many patients are ready for discharge 3 to 4 days after surgery

• For the first 6 weeks after surgery, patients are instructed to use an elevated toilet seat and to use one or two ordinary pillows between the knees when lying on the unoperated side

• Strengthening exercises for the abductor muscles help eliminate limp • Stretching exercises are continued until the patient is able to reach the foot for dressing and nail care • The feet are dressed by placing the ankle of the operated limb on the opposite knee

• Patients with left hip procedures usually can resume driving at approximately 6 to 8 weeks • When the right hip has been operated on, the decision should be individualized, depending on the return of strength, leg control, and reaction time

• Many patients with sedentary occupations can return to work after 6 to 8 weeks • At 3 months, patients can return to occupations requiring limited lifting and bending • We do not encourage patients to return to manual labor after total hip arthroplasty

• Limited athletic activity is permitted – Swimming, cycling, and golfing are acceptable

• Jogging, racquet sports,and other activities requiring repetitive impact loading or extremes of positioning of the hip are unwise

Joint arthroplasty improves cardiovascular fitness

• Ries et al. found significant improvement in exercise duration, maximal workload, and peak oxygen consumption in hip arthroplasty patients compared with controls treated medically

• Follow-up visits are made at 3 months, 6 months, and 1 year and periodically thereafter • Routine radiographs are made at 1- to 2-year intervals and compared with previous films for signs of loosening, migration, wear, and implant failure

• Regular follow-up is essential because loosening, wear, and osteolysis may occur in the absence of clinical symptoms, and revision is more difficult if the diagnosis is delayed until symptoms occur

Shoulder arthroplasty • Pain is the major indication – – – – – –

DJD AVN RA Traumatic arthritis Capsulorraphy arthritis Rotator cuff arthropathy

Shoulder arthroplasty • Glenoid component – Cemented all polyethylene

• Indication for total replacement – Incongruent osseous surface + – cartilage loss + – repairable rotator cuff

Keeled prosthesis

Pegged prosthesis

Reverse prosthesis

Elbow arthroplasty

Radial head arthroplasty