Adult Reconstruction

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Adult Reconstruction

Edward J. McPherson

SECTION 1 HIP DYSPLASIA—ADULT PRESENTATION

I. Natural History

II. Spectrum of Presentation

III. Classification of Adult Hip Dysplasia

IV. Acetabular Dysplasia

V. Proximal Femoral Dysplasia

VI. Clinical Syndrome Associated with Dysplasia

VII. Dysplasia Treatment

SECTION 2 HIP ARTHRITIS ASSESSMENT

I. Physical Examination Tests for Hip Irritability

SECTION 3 HIP ARTHRITIS TREATMENT

I. Nonoperative

SECTION 4 OSTEONECROSIS OF THE HIP

III. Clinical Presentation

SECTION 5 TOTAL HIP ARTHROPLASTY

II. Implant Fixation

III. Bone Ongrowth Fixation

IV. Hydroxyapatite

V. Primary THA—Fixation Selection

VI. Femoral Stem Loading

VII. Femoral Stress Shielding

VIII. Femoral Stem Breakage

SECTION 6 REVISION THA

I. Presentation

II. Acetabular Side

III. Femoral Side

SECTION 7 OSTEOLYSIS IN THA

I. Introduction

II. Osteolysis Process

III. Osteolysis Around THA Prosthesis—Effective Joint Space

IV. Particle Debris Formation—Linear versus Volumetric Wear

V. Osteolysis—Radiographic Findings in THA

VI. Osteolysis Reduction

SECTION 8 PERIPROSTHETIC THA FRACTURE

I. Time of Fracture

II. Perioperative Fracture

III. Late Fracture

SECTION 9 TOTAL ARTICULAR RESURFACING

II. Relative Contraindication

III. Complication

SECTION 10 THA—MISCELLANEOUS

I. THA—Nerve Injury

II. THA—Anatomy

III. THA—Specific Complications

IV. Venous Thrombosis in THA

V. THA—Surgical Approach

VI. THA—Implant Facts

SECTION 11 THA—JOINT STABILITY

I. Incidence of THA Dislocation

II. Risk Factors for Dislocation

III. Dislocating THA—Assessment

IV. Component Design

V. Primary Arc Range

VI. Lever Range

VII. Component Design—Best Range in THA

VIII. Component Alignment

IX. Soft Tissue Tension

X. Soft Tissue Function

XI. Dislocating THA—Treatment

SECTION 12 THA—ARTICULAR BEARING TECHNOLOGY

I. Bearing Types

II. Hard-on-Soft Bearing

III. Hard-on-Hard Bearing

SECTION 13 KNEE ARTHRITIS ASSESSMENT

I. Clinical Presentation

II. Imaging Studies

SECTION 14 KNEE ARTHRITIS TREATMENT

I. Nonoperative

SECTION 15 TOTAL KNEE ARTHROPLASTY

II. TKA Survival

III. Technical Goals of TKA

IV. Preoperative Planning for TKA

V. Bone Cuts in TKA—Goals

VI. Coronal Plane Ligament Balancing in TKA

VII. Flexion Deformity

VIII. Sagittal Plane Balancing in TKA

IX. TKA—Complications

SECTION 16 TKA DESIGN

I. Design Categories

II. Cruciate-Retaining Primary TKA Design

III. Cruciate-Sacrificing Primary TKA Design

IV. Posterior Stabilized Primary TKA Design

V. Anterior Stabilized Primary TKA Design

VI. Tibial Rotating Platform in Primary TKA

VII. Modularity in Primary TKA

VIII. Constraint in TKA

SECTION 17 REVISION TKA

I. Preoperative Evaluation

II. Surgical Approach

III. Implant System

IV. Modular Bearing Change for Premature Excessive Wear

V. Revision TKA—Technique

VI. Revision TKA—Patella

SECTION 18 PATELLAR TRACKING IN TKA

I. Introduction

II. Q Angle in TKA

III. TKA Techniques to Optimize Patellar Tracking

IV. Intraoperative Assessment of Maltracking

V. Postoperative Assessment of Maltracking

VI. Patella Baja

VII. Patellar Resurfacing versus Nonresurfacing

SECTION 19 CATASTROPHIC WEAR IN TKA

I. Premature Failure of TKA Implant

II. Factors Involved in Catastrophic Wear

III. Polyethylene Thickness

IV. Articular Geometry

V. Knee Kinematics

VI. Surgical Technique

VII. Polyethylene Processing

VIII. Perfect Storm Scenario for Catastrophic Wear

IX. Measures to Mitigate Catastrophic PE Wear

SECTION 20 SHOULDER ARTHROPLASTY

I. Glenohumeral Arthritis and Glenoid Wear

II. Shoulder Arthroplasty—Contraindications

III. Charcot Arthropathy

IV. Shoulder Hemiarthroplasty

V. Total Shoulder Arthroplasty

VI. Rotator Cuff Arthropathy

VII. Reverse Total Shoulder Arthroplasty

SECTION 21 PERIPROSTHETIC JOINT INFECTION

I. Risk Factors

IV. Treatment Algorithm

V. Infection Prevention—Total Joint Replacement

VI. Wound Coverage in TKA

TESTABLE CONCEPTS

section 1 Hip Dysplasia—Adult Presentation

I NATURAL HISTORY

A Hip pain in adults under the age of 50 years usually is a result of hip dysplasia.

B Untreated dysplasia leads to degenerative joint disease in greater than 50% of patients by age 50 years.

C Initial presentation of symptoms is soon followed by degeneration.

1. Do not wait to treat surgically if osteotomy is being considered.

II SPECTRUM OF PRESENTATION

1. Femoral acetabular impingement

B Advanced morphologic changes with significant arthritis

III CLASSIFICATION OF ADULT HIP DYSPLASIA

A Acetabular dysplasia

1. Too little coverage—classical

2. Too much coverage

3. Malaligned coverage

B Proximal femoral dysplasia

1. Altered head-neck offset

2. Altered neck version

IV ACETABULAR DYSPLASIA (Box 5-1 and Figure 5-1)

Figure 5-1 Anteroposterior pelvis radiograph displaying lateral center edge (CE) angle and acetabular index. Both hips in this case show a shallow socket dysplasia. The acetabular index should normally be horizontal, and the lateral CE angle should be 30 degrees.

A Classical (too little coverage)

1. Deficient head coverage

Lack of anterior and lateral coverage

2. Decreased acetabular depth

Socket is less than a hemisphere.

B Acetabular retroversion

1. Acetabular socket faces backward. (Normal socket faces forward, i.e., anteversion.)

Anterior wall is rotated forward.

Posterior wall is rotated backward.

2. Radiographic findings (Figure 5-2)

Figure 5-2 A, Diagram of acetabulum on anteroposterior radiograph. In a normal acetabulum, the socket is anteverted. On the anteroposterior radiograph, the anterior acetabular rim is above posterior rim. Three dimensionally, the acetabular socket is open and faces in an anterior direction. B, Diagram of acetabular retroversion. On the anteroposterior radiograph, the anterior rim is in a lower position, whereas the posterior rim is higher. Radiographically, the two rim lines cross, creating the crossover sign. Frequently with acetabular retroversion, the ischial spine is prominently seen. Three dimensionally, the acetabular socket is closed and faces in a posterior direction. Ant., anterior; AP, anteroposterior; Post., posterior.

Crossover sign is pathognomonic (on anteroposterior pelvis).

Frequently will see ischial spine on anteroposterior radiograph

C Acetabular overcoverage

1. Excess anterior and lateral wall coverage of the femoral head

2. Defined radiographically with downsloping acetabular index (>5 degrees downward)

3. Frequently associated with retroversion dysplasia

V PROXIMAL FEMORAL DYSPLASIA

A Head-neck dysplasia (Figure 5-3)

Figure 5-3 A, Diagram demonstrating normal head-neck offset. Offset is measured using lines parallel to the line defining the femoral head center and neck midline. B, In femoral neck dysplasia, the offset between the femoral head and neck is significantly reduced. A reduced head-neck offset increases the risk for neck impingement upon the acetabular rim.

1. Offset between edge of femoral head and edge of femoral neck is reduced (i.e., head/neck ratios reduced).

2. Radiographically this gives the appearance of a pistol grip deformity.

3. Head-neck offset is defined on the anteroposterior and lateral radiograph by the α-angle (Figure 5-4).

Figure 5-4 A, Anteroposterior radiograph measuring α-angle. The α-angle is a method to evaluate head-neck dysplasia. The α-angle is formed between the lines of femoral head center and neck midline, and femoral head center and head-neck junction. Normal α-angle typically is less than or equal to 40 degrees. B, Anteroposterior radiograph measuring α-angle in a dysplastic proximal femur. α-Angle is increased.

α-Angle is normally 40 degrees or less.

B Altered neck version

1. Excess neck anteversion

2. Neck retroversion

VI CLINICAL SYNDROME ASSOCIATED WITH DYSPLASIA

A Femoral acetabular impingement

1. Abnormal impingement between femoral neck and anterior acetabular rim

Contact is anterosuperior zone of acetabulum.

B Clinical progression

1. Impingement pain and hip inflammation

2. Labral degeneration leading to tears

3. Chondral surface degeneration and chondral flap tears

4. Degenerative joint disease is end result.

C Clinical presentation

1. Impingement test—positive

2. Significant restriction of hip internal rotation (tested with the hip at 90 degrees of flexion)

D Causes of femoral acetabular impingement

1. Acetabular based

Retroversion and/or overcoverage

2. Femoral based

Reduced head-neck offset

E Femoral acetabular impingement—two types

1. Pincer impingement (Figure 5-5)

Figure 5-5 Pincer type of femoral acetabular impingement. A, Diagram showing normal acetabulum and proximal femur. B, Diagram depicting acetabular retroversion. Retroverted acetabulum will limit functional hip flexion. C, Mechanics of pincer impingement. In hip flexion, the femoral neck abuts acetabular rim. Typically, this results in localized damage to the labrum. D, Ex vivo demonstration of pincer impingement. In this case, repetitive pincer impingement created a bony indentation trough on the femoral head at the site of flexion impingement.

Anatomic aberration between socket and femoral neck that creates a mechanical block preventing further hip flexion

The soft tissues between the bony mechanical block are pinched.

Typically the soft tissues damaged in pincer impingement are the acetabular labral complex.

2. Cam impingement (Figure 5-6)

Figure 5-6 Cam type of femoral acetabular impingement. A, Diagram depicting proximal femoral neck dysplasia with reduced head-neck offset. The “fat” femoral neck still is able to travel into acetabular socket a short distance. B, Mechanics of cam impingement. In hip flexion, the fat femoral neck acts as a cam (a raised area) that abrades the anterior-superior region of the acetabulum. Typically this results in shear delamination of the chondral surfaces of the acetabulum. C, Ex vivo demonstration of cam impingement. Notice how superior femoral neck is almost up to the level of the superior-lateral femoral head. This region (the cam) is what impinges upon the articular surfaces of the acetabulum in flexion. D, Magnetic resonance image of femoral acetabular impingement. In this case, there is a combination of cam and pincer impingement. There is an enlarged femoral neck (reduced head-neck offset), but clinically there is also pincer impingement upon the anterior acetabulum.

Anatomic aberration in the proximal femoral neck creates a raised area (cam). The neck cam impinges upon the articular surface of the acetabulum in hip flexion.

Compared to pincer impingement, the femoral neck is allowed to travel underneath the labrum a short distance, thus impinging more upon the articular surface.

Typically, the area of soft tissue damage in cam impingement is the chondral surface of the acetabulum.

VII DYSPLASIA TREATMENT

A Treatment depends upon the extent of deformity and location.

B Surgical correction goals are to relieve pain and to correct anatomic deformity. Long-term goal is to reduce the occurrence of degenerative joint disease.

C Surgical correction addresses the main anatomic deformity: shallow socket, retroverted socket, reduced femoral neck offset (i.e., fat neck), abnormal femoral neck version.

D Main surgical options

1. Periacetabular osteotomy

2. Anterior hip decompression

3. Proximal hip osteotomy

E Periacetabular osteotomy (Figure 5-7)

Figure 5-7 A, Model demonstrating periacetabular osteotomy (PAO). In the PAO technique, the posterior column is preserved. This maintains pelvic stability and allows for significant correction of acetabular tilt and version. B, Five-year postoperative radiograph of PAO. Notice acetabular index restored to horizontal and improved lateral center edge angle.

1. Allows large degree of socket correction

Correction of tilt and version

2. Permits joint medialization (i.e., center of hip rotation is positioned medial)

Lowers joint reactive forces

3. Technique advantages

Does not violate abductor complex

Does not violate posterior column

Allows early weight bearing

Low complication and morbidity rate

4. Technique goals

Acetabular roof index to zero

Head coverage: lateral center edge (CE) angle into normal range

Restored socket anteversion: no crossover sign

F Anterior hip decompression (Figure 5-8)

Figure 5-8 Intraoperative photographs demonstrating anterior hip decompression procedure. A, Lateral approach of right hip, using a greater trochanteric slide. The greater trochanter is retracted anteriorly. A Z-capsulotomy is performed, and the hip is dislocated anteriorly. B, Femoral osteoplasty. The excess bone in the anterior-superior femoral neck is removed. This improves head-neck offset. C, Labral tear identified in the anterior impingement zone of the acetabulum. D, Labral repair with suture anchor technique.

1. Technique is not used for shallow-socket dysplasia.

2. Technique incorporates three main steps.

Femoral neck osteoplasty (removal of cam bump)

Anterior acetabular rim osteoplasty (reduction)

Repair of soft tissue tears

Acetabular labrum

Acetabular chondral flap tears

3. Surgical approach

Trochanteric slide (vastas lateralis and gluteus medius both kept attached to greater trochanter)

Anterior dislocation of femoral head

Anterior Z-capsulotomy preserves posterior vessels to femoral neck. This minimizes risk for head osteonecrosis.

4. Hip arthroscopy for anterior hip decompression

Arthroscopy can be used for mild hip deformities with associated labral tears.

Arthroscopy can correct femoral deformity (i.e., femoral cam) better than acetabular retroversion.

G Proximal hip osteotomy

1. Main indications for proximal hip osteotomy

Correction of proximal femoral retroversion or excessive anteversion

Significant coxa valga with decreased lateral offset

section 2 Hip Arthritis Assessment

Patient assessment of hip pain includes a physical examination and diagnostic radiographic modalities.

I PHYSICAL EXAMINATION TESTS FOR HIP IRRITABILITY

A Impingement test

1. Hip flexion to 90 degrees

2. Hip adduction and internal rotation yield pain response.

3. Hip internal rotation only yields pain response.

4. Pain located in area of anterior hip with pain radiating to either posterior hip or lateral hip

B Roll test

1. Patient is positioned supine. Finger rolling of leg (at calf level) into internal rotation and external rotation

2. Leg will feel stiff or will occasionally grab.

C Stinchfield test

1. Patient is positioned supine. Active straight leg raise of approximately 20 cm against mild resistance by examiner

2. Patient will feel pain in anterior hip against resistance.

D Patrick test

1. Patient is positioned supine. Leg is positioned in figure-four position.

2. Pain will be elicited in area of anterior hip region or posterior hip region.

3. Be careful with interpretation of test. If pain is located over posterior pelvis, this indicates referred pain from L5-S1 facets or sacroiliac joint and not hip joint.

A Radiographs

1. Still the standard imaging modality for initial evaluation of hip pain

B Computed tomographic (CT) scan

1. Three-dimensional CT with pelvic remodeling used for preoperative planning for reconstruction associated with dysplasia planning, post-trauma planning, and complex revision total hip arthroplasty (THA) planning

C Magnetic resonance imaging (MRI)

1. Used when osteonecrosis suspected

2. Gadolinium MRI arthrogram useful when labral pathology suspected, especially when associated with femoral acetabular impingement

section 3 Hip Arthritis Treatment

I NONOPERATIVE

A Activity modification

1. Reduce impact-loading exercises

2. Reduce weight

3. Avoid stairs, inclines, squatting.

B Nonsteroidal anti-inflammatory drugs

1. Cyclooxygenase-2 inhibition

C Joint injections

1. Corticosteroid—anti-inflammatory treatment

Backbone of proteoglycan chain of articular cartilage

Improves joint rheology

3. Approved by Food and Drug Administration for knee use only in United States

D Assist device (cane or crutch)

1. Opposite hand of affected hip

II OPERATIVE

A Arthroscopy

1. Best indication

Traumatic labral tear not associated with dysplasia

Hip joint shows mechanical signs of locking, catching, and clicking.

2. Beware of labral resection in dysplasia.

Acetabular labrum provides stability in a shallow acetabular socket (labrum usually is hypertrophic).

Isolated removal of labrum will typically result in rapid progression of joint degeneration and pain.

In cases of significant dysplasia, arthroscopic débridement is not recommended.

3. Other indications

Loose body removal

Débridement of chondral flap tears

Diagnostic biopsy and therapeutic lavage

Diagnostic procedure

Undiagnosed mechanical hip pain

Degenerative arthritis

Therapeutic effect inversely related to severity of arthritis

Not helpful in moderate to advanced disease

Generally, will help only mechanical symptoms, not arthritic ache

4. Arthroscopy technique

Traction required

Fluoroscopy required

Long cannulated trochars that are designed for hip joint

5. Arthroscopy complications

Nerve injury—most frequent

Pudendal—due to traction post

Lateral femoral cutaneous—due to portal placement

Femoral—due to portal placement

Instrument breakage

Portal hematoma

B Osteotomy (adult)

1. Salvage osteotomy

Abandoned in favor of THA for degenerative hip arthritis

2. Reconstructive osteotomy

Periacetabular osteotomy is preferred procedure to correct early hip degeneration in the adult due to dysplasia.

See the section Hip Dysplasia.

1. See the section Total Hip Arthroplasty.

D Hip fusion

1. Less frequently used as THA technology advances

2. Classical indication

Very young male laborer

Unilateral hip arthritis

3. Energy expenditure

Approximately 30% increase in energy output during ambulation

4. Collateral arthritis

Abnormal gait causes arthritis in these adjacent joints in 60% of patients.

Contralateral hip

Ipsilateral knee

Symptoms of pain typically start within 25 years of hip fusion.

5. Hip fusion technique

Preserve abductor complex.

Many fusions are taken down for disabling pain in adjacent joints.

Select fusion technique that allows successful conversion to THA.

Greater trochanteric osteotomy with lateral plate fixation is preferred technique.

Be careful not to injure superior gluteal nerve, which innervates abductor complex.

6. Fusion position

20 to 25 degrees of flexion

Neutral abduction

Increased back and knee pain when fusion is in abduction

Neutral or slight external rotation of 10 degrees

7. Fusion conversion to THA

Indications

Disabling back pain—most common

Disabling ipsilateral knee pain with instability

Excess knee stress will cause knee ligament stretch-out if fusion position is incorrect.

Disabling contralateral hip pain

8. Function after conversion to THA

Hip function and clinical results directly related to integrity of abductor complex

Preoperative electromyogram of gluteus medius required

When hip abductor complex nonfunctional

Severe lurching gait will result.

THA will require constrained acetabular component.

E Resection arthroplasty

1. Usually last step before hip disarticulation in a frustrating downward clinical course

Incurable infection

Patients are most often immune compromised.

Recurrent periprosthetic THA infection

Failed hip fusion with infection

Chronic destructive septic arthritis

Noncompliant patient with recurrent THA dislocation

Usually multiply revised patient

Psychiatric condition

Profound dementia

Limb paresis or paralysis

Drug-seeking behavior

Intractable pain from arthritis

Hip fracture with open decubitus ulcers

Significant contracture interfering with hygiene and posture

Failed hip fusion in patient with prior major trauma to hip and/or pelvis

Soft tissue loss to hip region precludes successful placement of THA.

Neurologic injury to extremity precludes successful function of THA.

F Hemiarthroplasty

1. Relegated to specific limited role

Fracture treatment in low-demand elderly patient

Best indication—displaced subcapital hip fracture with little or no prior history of symptomatic hip arthritis

Patient not able to comply with standard THA precautions

Best indication for THA for hip fracture

High activity level

Subcapital or high neck fracture

Older population (age ≥70 years)

Low risk for dislocation (no dementia or Parkinson disease)

2. Hemiarthroplasty advantage

Maximize head/neck ratio.

Large-diameter ball requires more distance to travel before dislocation.

Suction fit provided by labrum

Enhanced stability negated if labrum and capsule resected

3. Hemiarthroplasty disadvantage

Groin pain in active individuals

Increased osteolysis (compared to THA) in active individual

Protrusio deformity if ball not sized well and osteoporosis present (Figure 5-9)

Figure 5-9 Protrusio deformity. A, Anteroposterior radiograph demonstrating protrusio deformity of cemented hip hemiarthroplasty. This patient suffers from osteoporosis. B, Conversion to total hip arthroplasty. Hip successfully reconstructed with protrusio revision cup with screws. Bone graft is placed into protrusio deformity.

section 4 Osteonecrosis of the Hip

I OCCURRENCE

A Incidence not precisely known

B No comprehensive information on number of asymptomatic cases

C More common in males

D Typically affects patients in late 30s or early 40s

II ETIOLOGY (see Chapter 1, Basic Science)

A Hypercoagulable states may explain many idiopathic cases of osteonecrosis of the hip.

B In all cases, end-stage result is vascular occlusion in the juxtaarticular sinusoids adjacent to joint.

III CLINICAL PRESENTATION

A Initial pain with sit to stand, stairs, inclines, and impact loading

B Pain location tends to be most noticeable in anterior hip.

C Can be acute in onset (acute infarct phenomenon), which can mimic an acute injury

A Start first with radiographs.

1. Pelvis, anteroposterior, and lateral radiographs

2. If osteonecrosis detected, must image contralateral hip

Fifty percent of osteonecrosis cases have bilateral involvement.

B MRI is the standard imaging modality when radiographs are negative and osteonecrosis is suspected.

V STAGING (Table 5-1)

Table 5-1

Modified Ficat Staging System for Osteonecrosis of the Hip

DJD, degenerative joint disease; MRI, magnetic resonance imaging.

A Modified Ficat system (incorporates MRI information)

VI TREATMENT

A Nonsurgical

1. Bisphosphonate treatment will decrease risk for head collapse.

2. Must start before crescent sign

B Surgical treatment

1. Surgical treatment depends on these major variables.

Head collapse (i.e., crescent)

Irreversible etiology

Examples of irreversible etiology

Continued steroid use

Hypercoagulable state

Extent of head involvement (by osteonecrosis)

Described as volume head involvement

Volume head involvement equals percent head involved on anteroposterior image multiplied by percent head involved on lateral image (e.g., 50% × 50% = 25% volume head involvement).

A—small lesion: less than 15% head involvement

B—medium lesion: 15% to 30% head involvement

C—large lesion: greater than 30% head involvement

2. Younger age and crescent (or worse)

THA is recommended treatment.

Cementless cup and stem

Improved bearing technology

Good pain relief and function

3. Younger age and no crescent

Common treatments

Core decompression

Treatment principles

Core decompression relieves pressure buildup within the femoral head by the inflammatory process.

Pressure relief translates to pain relief.

Stimulates a healing response

Bone and vascular neogenesis

Reversible etiology

Patients on chronic steroids have poor results with core decompression.

Small head lesion (A lesion)

Patients with medium and large head lesions frequently collapse.

Vascularized fibular strut (Figure 5-10)

Figure 5-10 Fluoroscopic images of vascularized fibular strut technique. Left, Fluoroscopic image showing core reamer introduced to subchondral plate of femoral head. Center, Burr is introduced to remove remaining necrotic segment. Right, Vascularized fibular strut is placed up against subchondral plate of femoral head. Base of strut is secured with a K wire. Particulate bone graft has been impacted around fibular strut.

Treatment principles

Surgical removal of necrotic segment

Large core hole is needed.

Vascularized fibular strut is placed up against subchondral plate of femoral head to prevent collapse.

Particulate bone grafting of adjacent resected bone

Medium (B) and large (C) lesions

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