delicate, sclerotic, raylike branchings emanating in a radial fashion from the central dense band
Axial CT scan of a patient with avascular necrosis of the femoral head (same patient as Images 8-12) shows clumping and distortion of the central trabeculae representing the asterisk sign (arrowhead) and an adjacent low-density region (arrow) representing the reparative zone.
To minimize the chance of fracture, place patients on crutches until there is clinical, radiographic, and MRI evidence of resolution. This may require 4–6 months. This condition affects and these patients have no associated risk factors as in osteonecrosis. In women, it classically develops, and the incidence of fracture is greater than in men. The disease rarely involves both hips at the same time. Occasionally, the opposite hip is affected months or years later. It is difficult to make a definitive diagnosis on the basis of standard radiographs because the only abnormality is mild osteopenia of the femoral head and neck.
The improvement observed in hips treated with CD plus demineralized bone matrix (DBM), although not statistically significant, may be clinically significant.
(citric acid, sodium citrate, and dextrose).
This is because symptomatic ON is characterized by an elevated intramedullary pressure & creating a hole in the cortex & cancellous bone of the proximal femur has been observed to immediately reduce that pressure (personal observation).
Avascular necrosis femoral head by DR RAJAT MALOT (MS,DNB, MNAMS,FELLLOWSHIP PAEDIATRIC ORTHOPAEDICS)
AVASCULAR NECROSIS FEMORAL HEAD By : Dr. Rajat Malot Assistant ProfessorSMS Medical college Jaipur
How to Approach a patient with Hip Pain• Detailed History : Trauma ,Drug intake,Any other joint involvement,Constitutional symptoms,Any metabolic or endrocrine disorder• Pain : Exact site, mode of onset,Radiation• Age• Gait : Antalgic /Trendelenberg
Anterior Hip pain or Lateral pain or Posterior hip painGroin pain Trochanteric painRule out: hip Rule out: hip Rule out: sciaticfracture, septic joint, fracture, bone tumor, nerve irritationand avascular referred pain from ,sacroiliitis due tonecrosis lumbar disc spondyloarthropathy, herniation lumbardisc or facet diseaseOther causes:OA, Other causes:RA, trochantericiliopectineal bursitis bursitis,OA, radiating Other causes:muscle from strain lumbar disc or facet disease
CLINICAL PRESENTATION No distinguishing Clinical Features/ High index of suspicion Asymptomatic Pain gradual & insidious in nature Range Of Motion (ROM) ; patient may walk with a limp Radiographic findings may appear after a delay of several months to years following the onset of symptoms
Characteristics Of Pain Focal over the groin / hip or it may radiate to the buttocks, anteromedial thigh or knee Induced mechanically by standing & walking & may be eased by rest May be very intense, throbbing, deep & often intermittent Worsened by coughing & at night 40% of patients have night pain asso. with morning stiffness A Click may be heard when the patient rises from a sitting position or on external rotation of an abducted hip
Range Of Motion ROM may be diminished, especially after collapse of the femoral head ROM may be limited, especially in flexion, abduction & internal rotation Gait :- Patients may walk with a limp. The Trendelenburg sign may be Positive To be diagnosed at an early stage, high index of suspicion, especially true with U/L involvement because of the high risk of the dev. of AVN in the C/L Hip
BLOOD SUPPLY OF FEMORAL HEAD The principal sources are the Lateral Epiphyseal Vessels (LEVs). LEVs Posterior Superior Retinacular Vessels (PSVs) Medial Femoral Circumflex Artery Profunda- Femoris Artery. LEV supplies lateral and central thirds of the femoral head When patent, the Artery of Ligamentum Teres(ALT) supplies medial third of the femoral head. Branches of LEVs & ALT anastomose at the junction of central & medial 1/3 of the femoral head
lateral circumflex A. Medial circumflex A. BLOOD SUPPLY OF FEMORAL HEAD
Blood Supply in Paediatric Age Gp. Till 4-7 years of age, the vascular anatomy in a age transitional stage of development. The ALT does not penetrate the epiphysis of the femoral head until 9 or 10 years of age. The Medial Circumflex Artery (br.of Profunda Femoris Artery), penetrates into the femoral proximal metaphysis but is prevented from passing into the femoral epiphysis by the growth plate. The blood supply to the femoral head is especially vulnerable during this time.
AVN HISTORY Konig (1888) => first described the condition coined the term Osteochondritis Dissecans Haenish (1925) => first case of idiopathic ischemic necrosis of the femoral head in an adult Arterial Occlusion (1940) was postulated as the cause of the necrosis. Pietrograndi (1957) => AVN d/t Steroid therapy
AVASCULAR NECROSIS Misnomer; Basically it is Osteonecrosis (dead bone) Also c/a Osteochondritis Dissecans / Chandler’s Disease in Young Adults 60% => B/L One of the most challenging problems faced by orthopaedic surgeons. Annual Incidence in US 15,000-20,000 Estimated Burden => 10% of total THR’s d/t AVN (50,000) 25% of total expenditure on AVN (1 billion $)
AVASCULAR NECROSIS M/c affects => Femoral Head M/c site => Anterolateral aspect (Being principal Wt. bearing portion) Incidence d/t Steroid usage & Trauma AVN only occurs in FATTY MARROW, which contains MARROW a Sparse vascular supply. In contrast to Hematopoietic supply marrow which has a rich blood supply
Does Elderly Persons are at increased risk for AVN????? AVN NO………………. Fat cells become smaller in elderly persons. The space between fat cells fills with a loose reticulum and mucoid fluid, which are resistant to AVN. This condition is termed Gelatinous marrow . Even in the presence of increased intramedullary pressure, interstitial fluid is able to escape into the blood vessels, leaving the spaces free to absorb additional fluid.
ETIOLOGYIntravascular ExtravascularExtraosseous Intraosseousvascular factor factors I. Arterial factors Capsular factorsIntraosseousvascular factors I. Arterial factors II. Venous factors
Extraosseous Vascular FactorsArterial Factors Most important Femoral Head blood supply is an End-Organ System with poor collateral development Trauma to the hip may l/t contusion or mechanical interruption to the Lateral Retinacular Vessels (main blood supply of the femoral head & neck)
Intraosseous Vascular FactorsArterial Factors Circulating microemboli that block the microcirculation of the femoral head In Conditions like- 6. Fat emboli (hyperlipidemia associated with alcoholism) 7. steroid therapy 8. SCD 9. nitrogen bubbles in decompression sickness
Intraosseous Vascular FactorsVenous Factors Enlargement of intramedullary fat cells or fat-loading osteocytes causes the cells to expand; this may be the most significant factor l/t obstruction of venous drainage Reducing venous outflow & causing stasis S/i Caisson disease & SCD
Extravascular FactorsIntraosseous Factors Ficat et al demonstrated increased bone marrow pressure in the femoral necks of a large number of patients with avascular necrosis of the femoral head (AVN). Steroid Alcohol & Steroid Hypertrophy of Fat cells Gaucher cells & Inflammatory cells Encroach on intraosseous capillaries Direct toxic metabolic Intramedullary circulation effect on osteogenic cells Compartment syndrome
Extravascular FactorsCapsular Factors Trauma, Infection & Arthritis Effusions within the Hip joint Intracapsular Pressure Tamponade of the LEVs
SEQUELAE OF AVNMinimal AVN More Severe AVN Avascular area is small Once AVN develops, repair & is not adjacent to an Begins at the interface b/w articular surface. viable bone & necrotic bone Patient may be Asymptomatic Ineffective Resorption of Healing may occur dead bone within the necrotic spontaneously or the focus is the rule. disease may remain Mixed sclerotic and cystic undetected appearance on radiographs.
SEQUELAE OF AVN MECHANICAL FAILURE Non-healing Micro# in Subchondral regionCollapse of the Vicious Cycle Diffuse Subchondral #Articular Cartilage X-Ray :- Crescent Progressive Wt. Bearing Degenerative joint disease (DJD) & Joint Dissolution
CAUSESSteroid (35-40%) 6 mechanisms• Fat Emboli from the liver => Occlusion of Small Vessels• Steroid Intramedullary Fat Cells Size without an equivalent compensatory loss of trabecular & cortical bone => Intraosseous pressure• Fat Emboli Hydrolysis FFAs Toxic to vascular endo. Intravascular Coagulation• Synthesis of Polyclonal Antithyroid Hormone Receptor Alpha-Ab (-) Angiogenesis Proteolytic Activity10.A direct toxic effect occursSteroid Induced Blood Flow on osteogenic cells11.Hematopoietic Marrow Fatty Marrow > 20 mg & 6 Wks => Risk
Investigations MRI SPECT CT Scan Plain X-Ray Most Sensitive Reflects Vascular Integrity Unable to detect disease of 1.5-T magnet Avascular Focus may be stage 0 or 1 88% sensitivity demonstrated Early in 100% specificity Disease (MRI Contrast) Helpful in assessing flattening of the Femoral Head & asso. 94% accuracy 85% sensitivity Degen. changes (Beltran et al) (Collier) For Extent of Involvement Indispensable for Triple-Head High- e.g. Subchondral Lucencies Accurate Staging resolution SPECT & Sclerosis during Reparative stage of AVN because Sensitivity 97% images clearly depict (Lee et al) Enables detection of subchondral or12. Size of the lesion cancellous # & collapse13. Gross estimates of
Radiology- sequential Changes• Crescent Sign• Osteoporosis• Sclerosis• Cystic changes• Loss of spherical weight bearing dome• Partial collapse of head• Secondary Osteoarthritis
MRI Findings Classic Findings:- look for focal lesion in the anterosuperior portion of femoral head that is well demarcated but is inhomogeneous T1 images => low signal intensity T2 images => double line sign => classic sign of AVN, made up of 2 concentric low and high signal bands high-signal-intensity line may represent hypervascular granulation tissue
MRI T1image ∀ ↓ signal from ischemic marrow • Single band like area of low signal intensity. • 100% sensitivity • 98% specificity
Double Line sign – T2 image • A second high signal intensity seen within the line seen on T1 images. • Represent hyper vascular granulation tissue
Prominent & Thickened but Normal Trabeculae ASTERISK SIGNAxial CT: Patient without AVN of the Femoral Head
TRANSIENT OSTEOPOROSIS OF THE HIP (TOH) D/D:- No findings of bone infarction or repair, which are the hallmarks of osteonecrosis The pathologic picture is primarily one of marrow edema, hence also referred to as Bone marrow edema syndrome (BMES) Clinically, pain is usually more sudden, severe in females esp.during 3rd trimester of pregnancy Dx can be made readily based on MRI in most cases TOH is usually self-limited.T/t is protected weight bearing to prevent #. Infrequently, core decompression may be indicated if a patient has an inordinate amount of pain or if the diagnosis is in doubt. A diffuse low signal intensity in the T1-weighted image and a high intensity in the T2-weighted image
CLASSIFICATION & STAGING • In the 1960s, Arlet & Ficat in France described a 3-part staging system & in the 1970s a 4th stage was added Paul FICATThis form is perhaps the one most widely used now, despite the fact that a stage 0 & a transitional stage were added later
Paul FICAT 1917-1986 FICAT’s scientific works spanned a wide range of topics from ligament instability to osteoarthrosis & from chondromalacia patellae to AVNTo each area he brought not only the perception of the clinicianbut also the ability to see with the eyes of the physiologist, themicroscopist & even the electron microscopistHe was one of the few orthopedic clinicians with the ability to“see” problems at the cellular and subcellular level
Ficat & Arlet Classification t Stages of Bone Necrosis Stage Clinical Features Radiographs0 Preclinical 0 01 Preradiographic + 02 Precollapse + Diffuse Porosis, Sclerosis, Cysts3 Early Collapse ++ Crescent Sign Certain Sequestrum, Joint Space Normal4 Osteoarthritis +++ Flattened Contour Decreased Joint Space Collapse of Head
A major disadvantage was that it didn’t include any measurement of lesion size or articular surface involvement..
Radiographic Staging (Marcus et al 1973) Stage 1 : Asymptomatic, mottled increased density of femoral head Stage 2 : Asymptomatic , area of necrosis demarcated by a rim of increased density Stage 3 : Intermittent pains, Crescent sign in frog lateral view Stage 4 : Painful limb & flattening of femoral head Stage 5 : Symptoms & signs of degenerative arthritis Stage 6 : Severe degenerative arthritis
Steinberg et al (1995) Modified Ficat & Arlet ClassificationStage 0 – 3 :- Same as Ficat ArletStage 4 :- Flattening of femoral headStage 5 :- Joint narrowing with or without acetabular involvementStage 6 :- Advanced degenerative changes These stages were further divided into Mild, Moderate & Severe
1974, Kerboul et al noted that the results of osteotomies performed for osteonecrosis depended on both the location & the extent of the lesion This latter was expressed in degrees after measuring the arc of the articular surface involved as seen on both AP and lateral radiographs of the femoral head. Similar observations were reported by Wagner and Zeiler , Sugioka et al. and Koo and Kim
University Of Pennsylvania Classification of Osteonecrosis 0 Normal or nondiagnostic x-ray, bone scan, and MRI I Normal x-ray; abnormal bone scan and/or MRI A. Mild (15% of femoral head affected) B. Moderate (15%–30%) C. Severe (30%) II “Cystic” and sclerotic changes in femoral head A. Mild (15% of femoral head affected) B. Moderate (15%–30%) C. Severe (30%) III Subchondral collapse (‘Crescent Sign’) without flattening A. Mild (15% of articular surface) B. Moderate (15%–30%) C. Severe (30%)
University Of Pennsylvania Classification of Osteonecrosis IV Flattening of femoral head A. Mild (15% of surface and 2 mm depression) B. Moderate (15%–30% of surface or 2–4 mm depression) C. Severe (30% of surface or 4 mm depression) V Joint narrowing and/or acetabular changes A. Mild (Average of femoral head involvement as determined in stage IV & estimated acetabular involvement) B. Moderate (Average of femoral head involvement as determined in stage IV & estimated acetabular involvement) C. Severe (Average of femoral head involvement as determined in stage IV & estimated acetabular involvement) VI Advanced degenerative changesFrom Steinberg ME, Brighton CT, Corces A. Osteonecrosis of the femoral head: Results of core decompression and grafting with electrical stimulation
1991, The Committee on Nomenclature & Staging of the Association Research Circulation Osseous (ARCO) endorsed the staging system developed at the University of Pennsylvania in the early 1980s 1992, location of the lesion, as described in the Japanese system , was added 1993, stages III & IV were combined, as were stages V & VI
Mitchell’s MRI StagingClass T1 T2 DefinitionA Bright Intermediate Fat signalB Bright Bright Blood signalC Intermediate Bright Fluid or edema signalD Dark Dark Fibrosis signal
Criteria For Diagnosis (Current Concept JBJS Mont & Hungerford)Specific Criteria Non specific criteria Collapse of femoral head Collapse of femoral head with narrowing of joint space Subchondral radiolucent line Mottled ,cystic & sclerotic pattern in Anterolateral sequestrum head Bone scan showing a photopenic MRI showing changes in bone region surronded by area of increased density marrow Double band on T2-weighted Painful movements of hip with image normal X ray Bone biopsy showing empty H/O of alcohol & steroid intake lacunae involving multiple adjacent trabeculae Non specific but abnormal biopsy , edema /fibrois
AIM OF TREATMENT Preserve rather than Replacing Femoral Head & Cartilage Early Intervention has favorable impact on the disease prognosis irrespective of T/t modality used
Medical Management Indications:- Small, Asymptomatic lesions Lesion is so advanced that prophylactic measures would be of little value When Sx is contraindicated or declined Buying time until arthroplasty is needed
PROTECTED WEIGHT BEARING Protect the involved area from excessive stress by using some form of limited weight bearing. Canes or even crutches are frequently prescribed Don’t alter the natural course of the disorder INDICATIONS:- Alternative to surgical management Small, Asymptomatic lesions low weight bearing area, such as the medial aspect of the femoral head Poor medical condition Following certain types of surgical procedures, such as core decompression, grafting, and osteotomies (used as an adjunct) Most important role :relatively advanced stages of osteonecrosis. Cane or Crutches can diminish symptoms and improve function considerably until such time as a reconstructive procedure is indicated
Glueck & colleagues => Incidence ofosteonecrosis in association with certainCoagulopathies & Hyperlipidmias
Motomura et al => Incidence of Steroid-inducedosteonecrosis in rabbits using a combination ofWarfarin & Probucol (Lipid Lowering Agents)
ENAXOPARIN adminstered for 12 weeks wasfound to prevent radiographic Progression ofStage 1 and Stage 2 idiopathic osteonecrosisof the femoral head at 2 year follow up
Gauthier => 95%-100% of transplant patientswho were treated with Calcium ChannelBlockers experienced complete relief of BonePain Syndrome
I.V. ILIOPROST, a Vasoactive Prostacyclinanalogue showed significant improvements inpatients with Bone Marrow Edema Syndrome &Osteonecrosis
Oral Nifedipine => Relief of bone pain reportedin a small series of patients with Osteonecrosis
Alendronate :- In a prospective study of 100 hips with osteonecrosis, Agarwal et al reported that l/t significant improvement in Pain & Disability scores Marrow edema improved on MRI & plain films were unchanged or progressed one grade In a prospective randomized study of 40 patients with stage II or III osteonecrosis & minimum 2-year follow-up, only 2 of 29 patients taking alendronate experienced collapse of the femoral head, whereas 19 of 25 heads in the control group collapsed
Bisphosphonates => reportedly causingOsteonecrosis of the Jaw , so should be usedcautiously
Puerarin :- An extract of the kudzu vine , is purported to Cholesterol, Platelet Aggregation & cause Vasodilation. In a study of Alcohol-induced Osteonecrosis in mice, puerarin was reported to lower serum cholesterol & to prevent the changes of osteonecrosis in femoral heads. No data on the use of puerarin for osteonecrosis in humans are available
Electric, Electromagnetic & Acoustic T/t Pulsed Electromagnetic Field stimulation, is reported to be useful for treatment of osteonecrosis in 4 reports. Mechanisms Of Action:- 5. Local control of inflammation 7. Enhances repair activity & healing process by stimulating neovascularisation & new bone formation.
Radiographic progression in Ficat stage II . Hips treated with core decompression (CD) plus pulsed electromagnet fields (PEMF) exhibit 33% less radiographic progression than hips treated with CD alone (P 0.04)
Extracorporeal Shockwave Therapy There are only 2 papers in Pubmed The only study is by Wang et al who compared the results of such therapy in 23 patients (29 hips) with the results in a group treated with non-vascularized fibular grafting At a mean of 25 months, 79% of the shock-wave group had improved Harris Hip Scores compared with 29% of the group treated with non-vascularized fibular grafting
Hyperbaric oxygen (HBO) HBO improves oxygenation, reduces oedema & induces angioneogenesis, a reduction in intra osseous pressure & improvement in microcirculation Reis et al, 24 involving 16 hips in 12 patients, all with Steinberg Stage 1 disease, gave each patient 100 consecutive days of HBO, which involved breathing 100% oxygen via a maskat 2-2.4 atmospheres pressure for 90 minutes They reported that 13 of the 16 femoral heads subsequently appeared normal on MRI after this T/t
Bone Marrow Injections Supplemented with Core Decompression Principle:- The small no. of progenitor cells in the proximal extremity of the femur with osteonecrosis of the femoral head causes insufficient creeping substitution after osteonecrosis Red Bone Marrow Graft contains Osteogenic Precursors,which repopulate the osteonecrotic bone
Bone Marrow InjectionsTechnique Usual site => Anterior Iliac Crest A beveled metal trocar of 6 to 8 cm length & a bore of 1.5 mm is pushed deep into the cancellous bone Marrow is aspirated with A 10 ml syringe(flushed with heparin) Aspirates pooled in plastic bags containing an anticoagulant solution Filtered to remove fat aggregates & clots Trocar
Bone Marrow Injections Current Indications:- The best indications are hips with osteonecrosis & without collapse In some patients who had Steinberg stage III (subchondral crescent, no collapse), successful outcomes (no further surgery) have been obtained between 5 and 10 years. Therefore, in selected patients, even more advanced disease can be considered for core decompression
Surgical proceduresJoint Preserving Joint Replacing Core Total Hip Decompression Arthroplasty Various Hip Resurfacing Nonvascularized & Procedures Vascularized Bone Grafting Procedures Osteotomy Procedures
Core Decompression Core decompression was “discovered” by Paul Ficat & Jacques Arlet in the 1960s Incidental discovery
Core Decompression Indications:- Core decompression is effective for symptomatic relief in nearly all stages in all patients who present with a painful hip secondary to ON d/t of intramedullary pressure done by it Transient symptomatic relief in an advanced stage & in already collapsing or when collapse is impending It is Most Effective in Stage I & II lesions that are size A (15% of head affected) & B (15%–30% of head affected) The larger the lesion, the less likely the patient is to have a successful outcome.
Core DecompressionStandard Technique & its Variations:- Ficat & Arlet proposed creating an 8 to 10 mm dia core track & this became a “standard” Recently some authors have suggested that the same effect of standard core can be achieved by producing Multiple Smaller Core Tracks of 3-mm dia range. This can be done percutaneously & theoretically # risk & shortens the operative time & morbidity Steinberg et al proposed making Smaller Angled Core Tracks into the Necrotic Segment from the Central Core Canal
Core Decompression Postoperative Management The lateral cortical window produces a stress riser in the proximal femur So Protect the patient from unprotected weightbearing for the first 6 weeks Reported incidence of # with core decompression is <1% & has almost always been associated with either a fall or failure to use protective devices (crutches or a walker) in the first 6 weeks
Bone Grafting Procedures Bone grafting procedures are a group of joint preserving techniques that involve the removal of the diseased femoral head segment, f/b its replacement with 1or more of a variety of bone graft options These are most valuable in treating patients with Stage I & II disease
Bone Grafting Procedures Techniques:- Grafting Through Lateral Core Track Grafting Through Femoral Neck Window Grafting Through Articular Surface Window
Grafting Through Lateral Core Track Advantages:- Simple technique Minimal Invasiveness Avoidance of surgical dislocation of the hip Low Complication Rate Can be performed bilaterally under one anesthetic Disadvantages:- Inability to directly visualize the joint surfaces Inexact nature of removing diseased bone & replacing it with bone graft under fluoroscopic guidance Risk of postoperative #
Grafting Through Femoral Neck Window Watson-Jones or Smith-Peterson approach is used A window is created to expose the anterior femoral neck, at the level of the junction of the femoral head & neck When Combined with a Bone Grafting procedure,refered as the “light bulb” procedure. Advantage is the improved access to the necrotic femoral head segment & the avoidance of direct iatrogenic cartilage damage Disadvantage is the creation of a cortical defect in the femoral neck, which raises the risk of fracture
Grafting Through Articular SurfaceWindow The 3rd method of accessing the necrotic segment of the femoral head is known as the “Trapdoor” approach With this method, the hip is surgically dislocated using a technique aimed at preserving the blood supply to the femoral head & neck Once exposed, a “trapdoor” window is made in the femoral head cartilage to access the diseased subchondral bone When combined with a bone grafting procedure, refered as the “Trapdoor” Procedure Advantage : Exposure allows a direct evaluation of the cartilage surface & underlying diseased femoral head segment & allows for precise bone graft placement. Disadvantage : Demanding technical nature Iatrogenic cartilage damage & osteonecrosis
Types of Bone Grafts Nonvascularized Grafts Vascularized Grafts Nonvascularized cortical 2. Local pedicled grafts,which bone grafts are typically do not require microvascular prepared as several struts that provide structural reanastomosis support under the articular eg :Muscle-pedicle bone grafts surface within the evacuated Vascularized pedicle bone segment grafts This construct is often augmented with cancellous 6. Free vascularized grafts, bone graft in an effort to which require a improve its osteoconductive microvascular and/or osteoinductive reanastomosis. properties eg: Free vascularized fibula graft
Muscle-Pedicle Bone Grafts Baksi et al (1991) => results in treating 68 hips with a variety of muscle-pedicle bone grafts The preferred techniques were the tensor fascia lata-iliac crest graft anteriorly & the quadratus femoris posteriorly. Of note, 82% of the hips treated in the series demonstrated some degree of collapse At a mean follow-up of 7 years, there were good to excellent results in 83% of cases
The harvested fibula with marbleized muscle attached confirming anextraperiosteal dissection. The peroneal artery & two accompanyingveins
Proximal Femoral Osteotomies The main rationale proposed for the efficacy of osteotomies is the biomechanical effect of moving the collapsed/necrotic segment of the femoral head from the principal weight-bearing area of the hip to an area that bears less/no direct weight and to allow weight-bearing contact to now happen in an area of relatively normal bone and cartilage
Proximal Femoral Osteotomies Categories:- Valgus or varus osteotomies usually combined with flexion or extension Transtrochanteric rotational osteotomies
Proximal Femoral Osteotomies Indications:- For varus or valgus osteotomies depend on the location & size of the lesion Osteotomies may be used for both precollapse & postcollapse without notable acetabular involvement
VALGUS OSTEOTOMY WITH FLEXION• when the necrotic segment is located in the anterosuperior part of the femoral head with less than 20% posterior involvement.• Optimal patient population would be those that are less than 45 years of age and are not on steroids or chemotherapy
VALGUS OSTEOTOMY WITH FLEXION AND BONE GRAFTING
ROTATIONAL OSTEOTOMIES• Sugioka first reported a transtrochanteric transposition osteotomy with anterior rotation of the head and neck of the femur
ROTATIONAL OSTEOTOMY before rotation After rotationTransposition of the necrotic focus to the ant. & inf. part of the femoral head awayfrom the weight-bearing area as a result of the ant. rotation of the head
Hip Resurfacing ProceduresFemoral & Acetabular Surface Replacement & Hemi- Surface Replacement for Osteonecrosis of the Hip Indications :- Later stages of osteonecrosis (University of Pennsylvania Stage III–VI) > 30% femoral head involvement
Metal-on Polyethylene Resurfacing Paltrinieri & Trentani (Italy) & Furuya (Japan) (1971) independently were the first to perform metal-on polyethylene resurfacing Townley introduced a total articular resurfacing arthroplasty (TARA; Depuy, Warsaw,IN) that resurfaced the femoral head with a metal component while replacing the articulating surface of the acetabulum with a thin, plastic shell inserted with cement Metal-on-polyethylene resurfacing yielded unacceptably high failure rates. The polyethylene-induced osteolysis resulting from the mating of large metal femoral head components with thin diameter acetabular cups
Metal-on-Metal Bearings Reduces the incidence of long-term failure from aseptic loosening & osteolysis
Total Hip Replacement TOC for advanced osteonecrosis of the hip (University of Pennsylvania Stages IVB–VIC) Excellent pain relief & functional improvements More recent studies at intermediate follow up up to 10 years have demonstrated similar survivorship compared to total hip replacement for osteoarthrosis.
Femoral Endoprosthesis Initial changes are in the femoral head and not the acetabulum Replacing the femoral head would also be more conservative than the additive procedure of acetabular reconstruction, allowing for later simple conversion to total hip arthroplasty
Arthrodesis Mostly a salvage procedure in contemporary orthopedics In the patient with significant pain & disability & in whom nonsurgical T/t has failed with a contraindication to prosthetic replacement Clinical success can be achieved as it may relieve hip pain The recommended position is 0° to 5° of adduction, 25° to 30° of flexion & 0° to 15° of external rotation Later revision to a THR has a significant complication rate with less functional outcome
Resection Arthroplasty T/t of last resort Complete resection of the head & neck of the femur Can achieve a good range of pain-free motion & will be able to function reasonably well for most activities of daily living The use of a shoe lift is generally necessary as a result of the shortening of the extremity, which averages approximately 1.5 inches There will be a noticeable abductor lurch & patients will require some form of assistive device for ambulation Indication:- patient with severe pain and disability who is not a
Acrylic Cement Injection Debriding the necrotic zone then elevating & supporting the collapsed segment by the injection of cement Wood and coworkers reported on very preliminary results 21 of 20 cases All patients realized immediate pain relief with improved hip scores, with 3 patients undergoing early conversion to total hip arthroplasty Relatively invasive but may have the advantage of maintaining femoral head congruity Long-term results with perhaps a randomized controlled series will be necessary if this is a viable alternative to reconstructive surgery
POROUS TANTALUM ROD INSERTION A novel approach in T/t of stage I & II precollapse osteonecrosis This rod functions analogously to a Cortical Strut Graft allowing structural & osteoconductive properties
Sir Astley Paston COOPER 1768–1841“Young medical men find it so much easier to speculate then to observe. Nothing is known to our profession by guess. There is no short road toknowledge. Observations on diseased living, examinations of the dead & experiments upon living animals are the only sources of true knowledge.”