Chapter 81 - Surgical treatment of joint disease

Question 1

Which two main treatment goals are highlighted for equine joint disease?

Answer 1

Pain relief for functional use of the joint and arrest of disease progression.

Question 2

What type of joint disease is typically treated with medical management and exercise protocols?

Answer 2

Generalized osteoarthritis (OA).

Question 3

What are the two main functions of arthroscopy in joint disease management?

Answer 3

Diagnostic and therapeutic functions.

Question 4

How is arthroscopy considered when compared to more complex imaging modalities?

Answer 4

It is viewed as the gold standard due to its specificity and sensitivity.

Question 5

What novel technique is being researched alongside arthroscopy for assessing cartilage and subchondral bone?

Answer 5

Near infrared spectroscopy (NIR).

Question 6

What kind of information can optical coherence tomography (OCT) provide during arthroscopy?

Answer 6

Detailed, quantitative information about morphology of articular cartilage lesions.

Question 7

What has increased awareness of joint pathology in the stifle joint led to?

Answer 7

Increased recognition of meniscal and cruciate lesions that are not detectable by radiography.

Question 8

What is one potential benefit of lavage during arthroscopy?

Answer 8

The egress of joint fluid that may contain cytokines and cartilage wear particles.

Question 9

In what type of cases is arthroscopy generally found to be more therapeutically beneficial?

Answer 9

Acute cases, rather than chronic cases.

Question 10

Which chronic pathologies can sometimes be managed successfully with arthroscopy?

Answer 10

Osteonecrosis and cartilage fibrillation of the third carpal bone.

Question 11

Why do newly detached osteochondral fragments have a better treatment outcome if removed early?

Answer 11

Because early removal before OA develops prevents further joint degeneration.

Question 12

What is the main challenge associated with performing arthroscopy in terms of visual clarity?

Answer 12

Bleeding of intrasynovial tissues can impair visualization unless inert gas is used for distention.

Question 13

Answer 13

Figure 81-1. Arthroscopic image of a chip fragment off the distal radial carpal bone before (A) and after removal (B).

Question 14

Answer 14

Figure 81-2. (A) Arthroscopic image of a slab fracture of the third carpal bone before reduction. (B) Lateromedial radiographic view of the slab fracture seen in (A) after reduction and fixation using a 4.5-mm cortex screw in lag fashion.

Question 15

Name the % for each prognosis:
excellent
good
guarded
poor

Answer 15

excellent 80% to 90% chance of athletic soundness
good 60% to 80%
guarded 40% to 60%
poor <40%

Question 16

What are the joints with good surgical removal of the osteochondral chip?

Answer 16

1 . extensor process
2. dorsal frontal p1 displaced and nondisplaced
3. proximodrosal P1
4. Plantar P1 (exceelent)
5. Palmar P1 (excellent)
6. Apical sesamoid
7. Abaxial sesamoid
8. Proximal RC
9. Proximal IC
10. Distal IC

Question 17

What are the joints with guarded surgical removal of the osteochondral chip?

Answer 17

1. P2 not involving DIP joint
2. Palmar P1
3. Basilar Sesamoid
4. Distal RC
5. C3

Question 18

What are the joints with poor surgical removal of the osteochondral chip?

Answer 18

1. P2 involving DIP joint
   and medical treatment of apical sesamoid

Question 19

Under what conditions are osteochondral fragments typically removed from horses?

Answer 19

Fragments are removed when diagnosed in conjunction with clinical lameness.

Question 20

Why might some osteochondral fragments be left in place?

Answer 20

If they are considered relatively benign and the horse does not exhibit clinical lameness.

Question 21

How has the routine use of arthroscopy affected the outcomes of osteochondral fragment removal?

Answer 21

It has improved outcomes compared to removal using arthrotomy.

Question 22

What is the general procedure for removing multiple osteochondral fragments?

Answer 22

Smaller fragments are typically removed first to avoid excessive portal size and maintain visualization.

Question 23

What is the significance of arthroscopic visualization when reconstructing intraarticular fractures?

Answer 23

It ensures proper alignment and optimal repair of the articular component for better outcomes.

Question 24

What tools are often used to prepare the parent bone during osteochondral fragment removal?

Answer 24

Hand curettes are used to débride the bone and smooth edges.

Question 25

Name two common types of intraarticular fractures encountered in equine athletes.

Answer 25

Condylar fractures of the third metacarpus (MCIII) and slab fractures of the third carpal bone.

Question 26

What technique is commonly used for internal fixation of intraarticular fractures?

Answer 26

Lag technique with screws.

Question 27

What is the primary purpose of performing a synovectomy in horses?

Answer 27

To aid arthroscopic visualization and as a therapeutic treatment for conditions like septic arthritis.

Question 28

How can the removal of synovium contribute to the treatment of septic arthritis?

Answer 28

It helps eliminate fibrin that may harbor bacteria, preventing recurrence of infection.

Question 29

In which equine joints is synovial membrane removal or synovectomy most frequently performed?

Answer 29

Tarsocrural, distal interphalangeal, and elbow joints.

Question 30

What methodologies have been used for conducting synovectomy in horses?

Answer 30

Surgery, chemicals, and radioisotopes, with motorized synovial resection being the most common surgical method.

Question 30

Why is complete understanding of the synovial membrane's role in equine joint disease still developing?

Answer 30

The role is not as well characterized as in humans, particularly in various forms of arthritis.

Question 31

What are the two main types of damage typically described in equine articular cartilage?

Answer 31

Chronic degenerative lesions and acute damage.

Question 31

What is the typical assessment approach for evaluating the outcome of cartilage repair?

Answer 31

Assessment is based on biochemical content, histologic appearance, biomechanical properties, and functional outcomes.

Question 31

Why do partial-thickness lesions and full-thickness articular cartilage lesions not heal spontaneously in horses?

Answer 31

Due to the specialized structure of articular cartilage and its limited regenerative capacity.

Question 32

When treating cartilage lesions, what approach is generally taken concerning the degree of débridement?

Answer 32

Minimally débride the cartilage, only removing damaged areas while leaving intact cartilage in place.

Question 33

What are the three classes of surgical options for cartilage repair mentioned in the text?

Answer 33

Palliative, reparative, and restorative.

Question 34

What does reparative surgical care include?

Answer 34

Marrow stimulation techniques, including microfracture.

Question 35

How are modern surgical techniques for cartilage repair evolving?

Answer 35

Techniques are combining methods and augmenting them with growth factors and other treatments for improved outcomes.

Question 36

Intra-articular fractures which ones are good prognosis?

Answer 36

1. Distal phalanx (except extensor process) 2. Proximal phalanx simple non-disp 3. Proximal phalanx noncommunituded displaced 4. MCIII/MTIII (noncommun) 5. MCIII/MTIII (complete nondisplaced) 6. MCIII/MTIII (incomplete nondisplaced)

Question 37

Intra-articular fractures which ones are poor prognosis?

Answer 37

1. Middle phalanx comminuted (S and M) 2. Proximal phalanx comminuted 3. Proximal sesamoid (midbody) 4. MCIII/MTIII displaced 5. C3 slab medical tx 6. C3 slab saggittal

Question 38

Intra-articular fractures which ones are excellent prognosis?

Answer 38

1. MCIII/MTIII (incompl, nondisplac) S and M tx 2.

Question 39

Intra-articular fractures which ones are guarded prognosis?

Answer 39

1. Distal halanx (type II) (M) 2. Middle phalanx (comminuted M or S 3. MCIII/MTIII comminuted 4. C3 slab (frontal) 5. C3 slab (sagittal)

Question 40

Answer 40

Figure 81-3. Arthroscopic image of microfracture spacing on the medial femoral condyle.

Question 41

What is the primary role of bone marrow in cartilage repair?

Answer 41

Bone marrow provides stem cells and growth factors essential for cartilage health and repair.

Question 42

Name three growth factors important in cartilage repair.

Answer 42

Insulin-like growth factor-1 (IGF-1), transforming growth factor-β (TGF-β), bone morphogenetic proteins (BMP) 2 and 7.

Question 42

Which surgical technique involves débridement to the level of the subchondral bone plate?

Answer 42

Abrasion arthroplasty.

Question 43

What is spongialization in the context of cartilage repair?

Answer 43

Débridement past the subchondral plate into cancellous bone.

Question 44

How deep should microfracture holes penetrate into the bone?

Answer 44

to access cells and growth factors beneath the subchondral plate without disrupting its biomechanical stability.

Question 44

Why is spongialization not favored in current clinical practice?

Answer 44

It is thought to destabilize the subchondral bone plate.

Question 44

What are the current recommendations for treating articular lesions?

Answer 44

Débridement to the level of the subchondral bone plate or in conjunction with subchondral bone microfracture.

Question 45

How deep should microfracture holes penetrate into the bone?

Answer 45

Approximately 2 mm.

Question 45

What is the purpose of subchondral bone microfracture?

Question 46

What outcome did the study involving 44 horses find regarding microfracture?

Answer 46

No proven association between microfracture use and long-term outcomes.

Question 47

What is a recent advancement in microfracture techniques?

Answer 47

The use of an injectable self-assembling peptide hydrogel.

Question 48

What did biochemical analyses reveal about repair tissues following microfracture?

Answer 48

Increased amounts of aggrecan and type II collagen compared to hydrogel alone.

Question 49

What is the consequence of drilling the subchondral bone plate?

Answer 49

Formation of subchondral bone cysts and poor histologic appearance of repair tissue.

Question 50

What is the significance of achieving petechial bleeding during débridement?

Answer 50

It indicates proper depth of débridement without entering cancellous bone.

Question 51

What does a granular appearance of the defect indicate?

Answer 51

The differentiation between the subchondral bone plate and the calcified cartilage layer.

Question 52

What does ACI stand for in cartilage resurfacing techniques?

Answer 52

Autologous Chondrocyte Implantation.

Question 52

Which grafting techniques have been used in cartilage defects?

Answer 52

Periosteal and perichondrial autografts, osteochondral grafts, chondrocyte autografts or allografts, and stem cell transplants.

Question 53

What is the average duration of pain resolution or improvement after microfracture?

Answer 53

2 to 3 years.

Question 53

How does the patient satisfaction with microfracture compare to ACI in long-term follow-ups?

Answer 53

Minor significant improvement with microfracture over ACI, but no significant differences in histologic appearance or outcomes.

Question 54

What are the limitations of using periosteal and perichondrial grafts in horses?

Answer 54

Disappointing results and no longer a focus of research.

Question 55

What is the main challenge with osteochondral grafting in horses?

Answer 55

Lack of congruity between recipient and donor tissues and surgical technique difficulties.

Question 56

What harvesting region is typically used for autologous chondrocyte harvesting?

Answer 56

A non-weight-bearing region, usually the trochlea of the distal femur.

Question 57

What are the advantages of the MACI technique over traditional ACI?

Answer 57

It uses a three-dimensional biodegradable material, reducing the need for multiple surgeries.

Question 58

What is a significant finding from experimental trials using a modified MACI technique in horses?

Answer 58

It has shown superior outcomes compared to ACI.

Question 59

What role do frozen chondrocytes harvested from neonatal foals play in cartilage repair?

Answer 59

They have shown success in limited chondral defects and are used more commonly in cystic defects.

Question 60

What is a major hurdle in using mesenchymal stem cells for cartilage defects in horses?

Answer 60

Accessing a sufficient number of stem cells without in vitro expansion.

Question 61

What is the purpose of using fibrin glue in cartilage defect treatments?

Answer 61

To retain cells in the chondral defect and enhance grafting success.

Question 62

What has research indicated about the long-term results of osteochondral plugs in horses?

Answer 62

At 12 months, transplanted areas appeared smooth, but some biopsies showed loss of glycosaminoglycans.

Question 63

What type of collagen is increased in repair tissues after microfracture?

Answer 63

Type II collagen.

Question 64

How are microfracture holes spaced during the procedure?

Answer 64

2 to 3 mm apart.

Question 65

What challenge does the ACI technique face in equine applications?

Answer 65

High cost, need for multiple surgeries, and technical challenges.

Question 65

What did the systematic analysis of microfracture outcomes reveal about knee function?

Answer 65

Improved function in all studies during the first 24 months, but conflicting long-term results.

Question 66

What type of cartilage defect treatment technique is considered promising for future equine use?

Answer 66

One-step techniques like the cartilage autologous implantation system (CAIS).

Question 66

What was a significant limitation identified in the equine osteochondral grafting techniques?

Answer 66

Morbidity at the donor site due to lack of suitable non-weight-bearing regions.

Question 66

Why might some clinical impressions of microfracture outcomes vary?

Answer 66

Possible functional deterioration and variable repair cartilage volume.

Question 67

What is a potential future direction for cartilage repair research mentioned in the text?

Answer 67

The use of bioprinted osteochondral constructs and ECM components.

Question 68

How does the technique of chondrocyte transplantation function?

Answer 68

Autologous chondrocytes are harvested, expanded in vitro, and implanted into defects.

Question 69

What is the significance of the study comparing ACI and subchondral bone microfracture?

Answer 69

It highlights differences in short-term and long-term results between the two techniques.

Question 70

Why is the microarthroscope important in assessing débridement levels?

Answer 70

It confirms the level of débridement by visualizing the defect margins.

Question 71

What factor contributes to poor attachment of repair tissue after microfracture?

Answer 71

Incomplete removal of the calcified cartilage layer.

Question 72

What ongoing research areas are focused on improving cartilage repair?

Answer 72

Bioprinting techniques and the application of mesenchymal stem cells.

Question 73

What is the primary indication for performing arthrodesis?

Answer 73

Destruction of a joint beyond the scope of other treatments.

Question 74

What is the expected outcome of arthrodesis for high-motion joints?

Answer 74

Alleviation of pain associated with movement and salvage for nonathletic function.

Question 74

Which joints typically require surgical fusion using internal fixation?

Answer 74

High-motion joints such as the antebrachiocarpal, midcarpal, metacarpophalangeal, and distal interphalangeal joints.

Question 75

What is the prognosis for athletic soundness in low-motion joint arthrodesis?

Answer 75

It often carries a reasonable prognosis for athletic soundness.

Question 75

What methods can be used for arthrodesis?

Answer 75

Surgical, chemical, or laser-based techniques.

Question 76

What risks are associated with chemical fusion of joints?

Answer 76

Unexpected anatomic communications with other structures and potential injury from overdistension.

Question 77

What is the current trend regarding the use of laser techniques in distal tarsal joint arthrodesis?

Answer 77

Early morbidity reports favor continued use of surgical arthrodesis over laser techniques.

Question 77

What preliminary studies have compared surgical drilling to laser ablation in distal tarsal joints?

Answer 77

Initial studies indicated that drilling may lead to quicker bony union, while laser procedures may reduce lameness resolution time.

Question 78

What is the typical lifespan of a joint implant?

Answer 78

Generally 10 to 20 years, depending on the implant type and location.

Question 78

When are joint replacements typically considered for patients?

Answer 78

When reparative procedures have failed and medical management is unresponsive.

Question 79

What challenges hinder equine joint replacement from becoming mainstream?

Answer 79

Cost of implants, difficulties with non-weight-bearing recovery, and surgical morbidity.

Question 80

What is a common goal in postoperative aftercare protocols?

Answer 80

To minimize the duration to full function return while maintaining athletic soundness.

Question 81

What support measures are often used in aftercare following joint surgery?

Answer 81

Bandaging, casts, and controlled exercise.

Question 82

Why is controlling postoperative inflammation important?

Answer 82

It benefits the healing process and reduces complications.

Question 83

When does maximal inflammation typically occur in a surgical wound?

Answer 83

3 to 5 days postoperatively.

Question 84

What medications are often used to control postoperative inflammation?

Answer 84

Systemic nonsteroidal anti-inflammatory medications.

Question 85

Why are corticosteroids contraindicated in the first four weeks post-surgery?

Answer 85

They can decrease cell metabolism, prolong healing time, and impair immune function.

Question 86

What substances have been studied for their chondroprotective qualities?

Answer 86

Hyaluronan and polysulfated glycosaminoglycans (e.g., Adequan).

Question 87

What has been a notable finding regarding the effectiveness of chondroprotective substances in postoperative healing?

Answer 87

They have not shown significant benefit in most studies, except in reducing adhesions in tendon sheaths.

Question 88

What emerging area in equine care is focused on enhancing postoperative recovery?

Answer 88

The field of equine rehabilitation, employing multimodal approaches for recovery.