Osteonecrosis of the Hip: Diagnosis and Management of

Ficat I and II

Natasha Holder, MD, MSc.PGY-1

Osteonecrosis of the femoral head◦ Etiology, Pathogenesis

Clinical Presentation Diagnosis Classification of AVN Management of Stage I and Stage II

◦ Non-Operative◦ Core Decompression◦ Bone Grafting◦ Osteotomy

Overview

AKA avascular necrosis or aseptic necrosis Disruption of the blood flow to the femoral

head (traumatic or nontraumatic) Commonly affects patients between 20 and

50 years of age Ultimate goal of treatment of ON of the hip

is preservation of the femoral head

Osteonecrosis of the Femoral Head

Trauma Corticosteroid use Alcohol abuse Smoking Sickle cell anemia Coagulopathies Systemic lupus erythematosus Hypercholesterolemia Organ Transplantation

Risk Factors for Osteonecrosis

JAAOS, 1999:250-261

Gaucher Disease Caisson Disease Radiation Therapy Arterial disorders Intramedullary hemorrhages Chronic Pancreatitis Hypertriglyceridemia HIV

Risk Factors for Osteonecrosis

JAAOS, 1999:250-261

Early in the disease process, the condition is painless

Chief complaint is pain Localized to the groin area, but it may also

manifest in the ipsilateral buttock, knee, or greater trochanteric region.

Painful symptoms are usually exacerbated with weight bearing but are relieved by rest

Clinical Presentation

History ◦ High index of suspicion◦ Risk factors◦ Groin pain, night pain

Physical Exam◦ Pain on internal rotation◦ Pain with active and passive ROM◦ Decreased ROM ◦ Antalgic gait◦ Examine the contralateral hip

Diagnosis

Laboratory tests◦ R/O systemic disease, coagulopathies

Radiological Tests◦ Plain film - AP and Frog leg lateral

Cysts, sclerosis or a crescent sign Crescent sign results from subchondral collapse of the

necrotic segment◦ MRI – Diagnostic Standard◦ Bone Scan

Special Tests◦ Bone marrow pressure, venography, biopsy

Diagnosis

Ficat and Arlet Classification

Non-operative Treatment Operative Treatment

◦ Core decompression◦ Non-vascularized bone-grafting◦ Vascularized bone-grafting◦ Osteotomy◦ Limited Femoral Resurfacing Arthroplasty◦ Total Hip Arthroplasty

Treatment of Osteonecrosis Non-operative Treatment Operative Treatment

◦ Core decompression◦ Non-vascularized bone-grafting◦ Vascularized bone-grafting◦ Osteotomy

Restricted weight bearing is NOT an treatment option except in small, asymptomatic lesions outside the weight bearing area

Meta analysis of outcomes of protected weight bearing in 819 patients demonstrated a failure rate >80 % at a mean of 34 months (Mont et al. Clin Orth Relat Res, 1996:169-78)

Non-Operative Treatment

Pharmacological agents: lipid-lowering drugs, anticoagulants, vasodilators and bisphoshonates

Prichett et al. report at a mean of 7.5 years, ON of the femoral head has developed in only 1% of 284 patients who were taking high dose steroids and a statin. (Clin Orthop 2001; 386:173-8)

Non-Operative Treatment

Glueck et al. used enoxaparin (60mg/day for 12 weeks) to treat patients with thrombophillic or hypofribinolytic disorders in early stages of ON

At 2 years, 89% (31/35 hips) had not required surgery and remained at the Ficat I or II stage (Clin Orth Relat Res, 2005:164-70)

Non-Operative Treatment

Bisphosonates inhibit osteoclast activity and thus curtail bone reabsorption

Agarwala et al. first reported the efficacy of bisphosphonates. Showed an improvement in Harris hip scores, retarded progression of of the disease and reduced rate of collapse (Rhemat. 2005:353-59)

Non-Operative Treatment

Agarwala et al.◦ prospective study ◦ 395 hips treated with 10 mg alendronate/day◦ F/U 1-8 years◦ 92% had a satisfactory result (no surgical

intervention)◦ Patients had improvement in clinical function, a

reduction in rate of collapse and a decreased requirement for THA

◦ Improvement is marked if treatment is begun in the pre-collapse stages

Non-Operative Treatment

Goal: to decompress the femoral head and reduce the intraosseous pressure

No general agreement on indications or technique

Substantial differences in success rates reported◦ poor staging of patient pathology◦ recurrent insults depending on pathology◦ variations in techniques

Core Decompression

Originally employed by Ficat and Arlet to obtain histological specimens

Decompression reduced bone marrow pressure allowing restoration of blood flow

Stulberg et al. (Clin Orthop 1991, 268:140-51)◦ Prospective, randomised study, 55 hips◦ 70% success by Harris Hip score with Ficat I, II, or III stage

Koo et al. (JBJS 1995, 77:870-74) ◦ Randomised control trial, 37 hips◦ Operative Group: 72% progression and 72% of those that

progressed required THA◦ Non-Operative group: 79% progression and 68% required THA

Core Decompression

Retrospective studies have shown that results of core decompression were substantially worse when there had been collapse of the femoral head preoperatively

Smith et al. (JBJS 1995, 77:674-80)◦ Retrospective review of 114 hips◦ Decrease in success rate if the crescent sign had

been present◦ 80% success rate for Ficat I, 20% If crescent sign

was present, 0% femoral head collapse

Core Decompression

Rationale:1. Decompress the femoral head2. Removal necrotic bone3. Replacement with autogenous cancellous bone4. Support the subchondral bone with a strong and

viable bone strut5. Revascularization the femoral head

Vascularized Bone Grafting

Vascularized Bone Grafting

Urbaniak et al. (JBJS 1995; 77:681-94)

◦ 103 hips, Mean F/U 7 years◦ Best results were seen in those with small or medium

precollapse lesions.◦ 11% (2/19) of pre-collapse group were converted to THA◦ 23% (5/22) of post-collapse group were converted to THA◦ 39% (24/62) of advanced lesion group were converted to THA

Berend et al. (JBJS 2003; 85:987-93)

◦ 224 collapsed hips◦ 64.5% survival rate at a mean 4.3 years (range 2-12)◦ Relative risk of conversion to THA was associated with an

increased lesion size and the amount of collapse

Vascularized Bone Grafting

Provides decompression of the femoral head, removal of necrotic bone and structural support and scaffolding to allow repair and remodeling of subchondral bone

3 distinct approaches 1. Core tract grafting2. Femoral Neck Window - Light bulb procedure.3. Trapdoor through articular cartilage of head

Nonvacularized Bone Grafting

Nonvacularized Bone Grafting

Lieberman et al. 2002; 84:834-853

Nonvacularized Bone Grafting

Meyers et al; JBJS 1973:55A,pg 257

Rosenwasser et al. (Clin Orthop. 1994:306:17-27)

◦ Described the “light bulb” approach◦ 87% success rate in a study of 15 hips with a

mean F/U of 12 years

Mont et al. (Clin Orthop. 2003: 417:84-92)

◦ 86% success rate in a study of 21 hips, light bulb approach

◦ Harris score >80 and no additional procedures

Nonvacularized Bone Grafting

Lieberman et al. (Clin Orthop 2004: 429:139-45)

◦ Retrospective study, 17 hips, Core track method◦ Used bone morphogenic protein◦ 14/17 successful result◦ Harris score >80 and no conversion to THA

Nonvacularized Bone Grafting

To remove necrotic or collapsing segment from the principle weight-bearing region

Replace this area with a segment of articular cartilage of the femoral head that is supported by healthy, viable bone

2 Types:

◦ Transtrochanteric Rotational Osteotomies

◦ Intertrochanteric varus/valgus Osteotomies

Osteotomy

Sugioka et al.◦ 78% of the 295 hips studied had a successful

outcome at a mean of 11 year F/U

Masuda et al.◦ 69% of 52 hips studied had a successful outcome

at a mean of 5 year F/U

Rotational Osteotomy

Best results in young active patients who were not taking corticosteroids, had unilateral involvement with a good preoperative range of hip motion, and had a small lesion without femoral head collapse

Rotational Osteotomy

Less technically demanding Commonly used in Europe with varying

success

Intertrochanteric Osteotomy

Merle d’Aubigne et al. ((JBJS(br), 1965; 47:612-33)

◦ Good to excellent pain reduction in 79% of the 75 hips with Ficat II or III. F/U 1 to 6 years.

Mont et al. (JBJS, 1996; 78:1032-38)

◦ Good to excellent Harris hip scores in 76% of the 37 hips studied after treatment with varus osteotomy. F/U mean 11.5 years

Intertrochanteric Osteotomy

Drescher et al. (JBJS (Br) 2003;85-B:969-74)

◦ 70 intertrochanteric flexion osteotomies. ◦ The mean follow-up was 10.4 years (3.0 to 20.3). ◦ The overall mean Harris hip score increased from 51

points preoperatively to 71 points postoperatively.◦ A total of 19 hips (27%) underwent total hip arthroplasty

at a mean of 8.7 years after osteotomy.◦ The five-year survival rate was 90%.

◦ Flexion osteotomy is a safe and effective procedure in Ficat stage 2 and 3, preferably with a necrotic angle of <200°

Intertochanteric Osteotomy

The size of the osteonecrotic lesion was determined to be a critical factor in the rate of success of the osteotomy

Intertochanteric Osteotomy

Stage Treatment

I (no radiographic changes) Non-Operative, Core Decompression

II ( precollapse) Core decompression, Bone grafting, osteotomies

Management of Ficat I and II

The etiology of ON of the hip may have a genetic basis

The interaction between certain risk factors and a genetic predisposition may determine the course of ON in a particular individual

The role of biological agents in altering the natural history of ON remains to be elucidated

Early diagnosis and intervention prior to collapse is key to successful outcomes of joint preserving procedures

Summary