Chapter 102 - Femur and pelvis Flashcards
(164 cards)
1
Q
A
Postoperative radiographic view of the femoral head region of a foal. Three 4.5-mm cortex screws were inserted in lag fashion into the capital femoral epiphysis. The trochanteric osteotomy used for the surgical approach to the joint was repaired with screws and tension band wires. There also was a radiolucent tension band placed under one washer.
2
Q
What types of horses are primarily affected by disorders of the femur and pelvis?
A. Only young horses
B. Only racehorses
C. Horses of any age, breed, or activity
D. Only older horses
A
C. Horses of any age, breed, or activity
3
Q
What are the most common surgically treatable conditions of the femur and pelvis?
A. Arthritis and ligamentous injuries
B. Fractures or coxofemoral luxations
C. Muscle tears and tendonitis
D. Joint dislocations
A
B. Fractures or coxofemoral luxations
4
Q
In which age group do proximal (head and neck) femur fractures most commonly occur?
A. Foals and weanlings
B. Adult horses
C. Elderly horses
D. Yearlings
A
A. Foals and weanlings
5
Q
What is a common cause of proximal femoral fractures in adult horses?
A
Severe traumatic events
6
Q
What is usually palpable with manipulation in cases of distal or diaphyseal femur fractures?
A
Crepitus
7
Q
How are diagnostic radiographs usually performed in larger horses?
A
Under general anesthesia
8
Q
What is the prognosis for surgical treatment of proximal femoral fractures in foals?
A
Good
9
Q
What are the techniques for surgical resolution of proximal (head+neck) fractures?
A
Techniques:
1.Screws inlag fashion
2.Cannulated screws
3.Dynamic hip screwplate (DHS chapter 72)
10
Q
What is the favored surgical approach for proximal (head and neck) fractures?
A
Craniodorsal
11
Q
What technique is used to enhance exposure during surgery for proximal femoral fractures?
A
A. Tenotomy of the middle or deep gluteal muscle
-Expose the femur by doing tenotomy of the tendon of the middleglutealmuscle atthe caudal greater trochanter (GT)
-OR tenotomy of the tendon of the deepglutealmuscle atthe cranial great trochanter (GT)
12
Q
Describe the surgery after tenotomy performed
A
-Osteomy of GT selected?
Drill holes for later tension-band repairshould be prepared before transecting the bone
-Oscillatingsaw or Gigli wireto cut GT from disto lateral to proximo-medial position
13
Q
What does the trochanteric osteotomy allow to move?
A
Trochanteric osteotomy allows middle gluetal muscle to be retracted proximally andmedially exposing theproximal aspect of the fémur and femoral head
14
Q
What is the prognosis of proximal head+neck fractures?
A
Guarded
15
Q
What can happen if you cut too deep the trochanteric osteotomy?
A
Damage the femoral head
16
Q
How should you prepare the great trochanter for placement of screws after and washers?
A
5.5 mm screws lag fashion
* Glide hole is drilled before reduction
- allow to check central position before entering ephiphysis withthread hole
* Combo of miminal lenght glide hole + central position of the bit = maximize the number of threads engaged in smaller fragment
- Washer are recommended so the screw 5.5 mm do not sink in soft cortical bone
Alignement is critical to prevent damage of articular surface
17
Q
What is the nerve that lies immediately caudal to the acetabulum and cannot be mobilized?
A
sciatic nerve
18
Q
How do you insert the screws following the GT removal?
A
3.2 mm drill bit to drill the thread hole through the lateralfemur upthe femoral neck and into the center of the femoral metaphysis.
Fracture is then reduced and the epiphysis drilled.
To prevent penetration of the articularsurface finger is placed in expected exit.
Drilling and tapping this initial hole while maintaining fracture reductionare difficult.
Loss of reduction makes it difficult toreposition and relocatethe 3.2 mm hole.
Leaving the initial drill bit in place tomaintain reduction à while drilling + inserting a second cancellous screw= is the most effective method forestablishing fixation without losing the reduction.
The guidepins in the 7.3 mm cannulated screw system achieve the same temporary fixation. Prior to tapping the hole, a depth gauge is used to determine the appropriate‐length screw and a 4.0 mm drill bit is used to expand and form a glidehole in the cortical bone of the lateral cortex. It is not necessary to enlarge this holethrough the entire metaphysis.
The cancellous tap will not easily pass through the lateral cortex, but will readily penetrate the metaphyseal bonealong the path ofthe 3.2mm drill.
The hole depth is determined from the millimeter gradations on the tap,allowing the surgeon toanticipate when the articularsurface is being approached, as well as to confirm the length of screw thatwill be necessary.
The cancellous tap is used to tap thehole within the epiphysis until it nears the surface of thearticular cartilage.
Insert 2 or 3 of 6.5mm cancellous screw
apply suction drain deep within the site
19
Q
What is the advantage of cannulated screws?
A
the reduction is maintained by the guide wire during entire procedure and you see depth
Disadvantage: bend easily
20
Q
Which fractures are considered the most difficult femoral fractures to diagnose without radiographs?
A
Proximal (head and neck) fractures
21
Q
Which implant provides more stability in femoral dyaphyseal fracture repair according to the text?
A
Double plating
22
Q
What is the primary location for third trochanter fractures?
A
Lateral aspect of the proximal third of the femur
23
Q
What is a proposed mechanism of injury for third trochanter fractures?
A
Avulsion
24
Q
What is the initial degree of lameness observed in horses with third trochanter fractures?
A
Moderate to severe
25
What diagnostic tool is often best for identifying third trochanter fractures?
Nuclear scintigraphy
26
What is the commonly elected management for third trochanter
fractures in horses?
Conservative management with fibrous union
27
How long is exercise restriction typically advised for horses with third trochanter fractures?
1 month of stall rest followed by 1-2 months of hand walking
28
What is the prognosis for return to soundness after a third trochanter fracture?
Fair to good
29
Which muscle serves as an insertion for the third trochanter at the apex?
Gluteus superficialis
30
What is the main symptom in the acute phase of a third trochanter fracture?
Mild swelling over the fracture region
31
What is the most common type of fracture encountered in the femur?
Middiaphyseal fractures
32
What is the typical shape of middiaphyseal fractures?
Spiral or long oblique
33
Where is the skin incision typically made for surgery on middiaphyseal fractures?
Laterally over the bone
34
What anatomical landmarks are identified after the fascia lata is incised during surgery?
Vastus lateralis and biceps femoris muscles
35
In the case of severe comminution, what method is used to reduce small fragments?
3.5-mm cortex screws in lag fashion
36
What is often used to prevent splitting the bone during reconstruction of a barrel stave fracture?
Cerclage wires or cables
37
Lateromedial radiographic view of a multifragment femoral fracture in a foal.
38
Lateromedial radiographic view of a multifragment femoral fracture in a foal.(C) and(D) Immediate postoperative radiographic views depicting the fracture repaired with two DCPs, one laterally and one cranially. Several fully threaded cancellous screws were used in the metaphyses. The arrow points toward the proximal end of the suction drain.
(E) Three-month follow-up radiographic view showing good fracture healing with substantial callus formation. A small fragment is visible at the cranial aspect of the bone.
39
How is the fracture usually reconstructed before reduction barrel stave fracture?
Into two main pieces
40
What technique is often used to maintain reduction during the progression of surgery barrel stave fracture?
Use of nylon cable ties or heavy cerclage wires
41
What types of plates are typically used for the repair of these fractures barrel stave fracture?
4.5- or 5.5-mm locking compression plates
42
How is the incision closed after surgery?
In at least three layers
43
What is an alternative technique mentioned for simple diaphyseal fractures?
Insertion of an interlocking intramedullary nail
44
What does the axial position of the intramedullary nail afford?
Excellent bending stability
45
What type of screws are placed through the bone and the intramedullary nail?
5.5-mm cortex screws
46
What is one major complication of interlocking intramedullary nails?
Fracture through the screw holes
47
What is a common outcome even in suboptimal repairs of femoral fractures?
Development of large calluses
48
What are the major advantages of using the locking compression plate (LCP) in femoral fracture repairs?
Enhanced stability and compression
49
How is a fracture reduced in the case of a long oblique fracture?
By clamping in an overriding position
50
What technique is applied in plate screws for additional compression and stability?
Lag technique
51
What must be done to prevent interference of screws in both plates?
Stagger the plates and insert screws perpendicularly
52
What is fundamental in the apposition of the plates in the lateral and cranial femur?
90º angle provides maximum stability and neutralizes the bending forces at fracture site
53
What is required to place the bone in alignment?
Vigourous traction so you need to attach the poney or foal to the table
54
Where are the gaps in the plate holes next to the screws typically filled with? A. Bone cement
B. Autologous cancellous bone
C. Antibiotic eluting material
D. Metal spacers
Antibiotic eluting material
55
Why is closed suction drainage essential in femoral fracture surgeries?
A. To minimize the risk of infection
B. To reduce swelling
C. To minimize accumulation of serum
D. To enhance healing
C. To minimize accumulation of serum
56
What is a critical step in the preparation for inserting an interlocking intramedullary nail?
Enlarging the medullary cavity
57
What is the main advantage of using interlocking intramedullary nails?
Excellent rotational and bending stability
58
How is the nail length preselected for an interlocking intramedullary nail insertion?
Using the length of the contralateral intact bone
59
What is a major complication associated with interlocking intramedullary nails?
Development of a fracture through the screw holes
60
How are cortex screws placed when using an interlocking intramedullary nail?
Perpendicular to the nail
61
What is the usual recommendation for follow-up radiographs in cases of femoral fractures?
6 weeks post-surgery
62
What age group is most commonly affected by distal femoral fractures?
Weanlings and yearlings
63
Where is the metaphyseal fragment usually positioned in most distal femoral fractures?
Caudally
64
Salter-Harris type II fracture of the distal femur. Lateromedial
65
caudocranial (C) radiographic views showing the repaired fracture. A DCS plate was applied laterally and augmented with a five-hole narrow DCP containing long screws penetrating the medial condyle. One single screw was buried in the articular surface to provide additional stability to the cranial aspect of the reconstruction. Longitudinally placed screws should augment the plate fixation. (
66
What type of incision is made for the surgical approach to distal femoral fractures?
Craniolateral
67
What must be transected for a parapatellar arthrotomy during surgery?
Lateral femoropatellar ligament
68
What kind of plate is preferred for repairing distal femoral fractures in larger yearlings?
Dynamic condylar screw (DCS) plate
69
For horses weighing less than 175 kg, which plate is easier to apply and strong enough?
Condylar buttress plate
70
What type of screws are recommended for fixation in distal femoral fractures?
5.0-mm locking head screws
71
What is the prognosis for distal femoral fractures of the femur?
Guarded
High risk of complications
If the complications are avoided there is a quick healing in young animals because of vascularity
72
What are common complications following surgery for femoral fractures?
Wound dehiscence and sepsis
73
How quickly can callus formation be seen radiographically in foals with femoral fractures?
A. Within a few weeks
B. 3 months
C. 6 months
D. Over a year
Within a few weeks
74
What is the primary reason that makes conservative management less favorable for younger animals with femur fractures?
Rapid development of varus deformity
75
A 6-month-old weanling suffering from a femoral shaft fracture of 1 month’s duration in the right hindlimb, which was treated conservatively. Note the marked varus deformity in the left hindlimb.
76
When is it not advisable to remove implants after femur fracture healing?
If the fracture healing is uncomplicated
77
What can result from physeal fractures of the distal femur?
Permanent closure of the growth plate
78
How is the metaphyseal part of the fracture during surgery often characterized?
Not readily visible
79
What is used to maintain alignment after reduction in distal femoral fractures?
A long screw placed through the intercondylar notch
80
What is a potential consequence of physeal fractures in the distal femur?
Shortened femur
81
In which condition is the conservative approach recommended for femur fractures?
Older animals or severe comminution
82
What should be applied postoperatively to keep the incision clean?
Adhesive or sutured stent bandage
83
Why is failure of plates and screws uncommon in adequately reduced femoral fractures?
Because of excellent vascularity and muscle coverage
84
Describe the surgical access to the distal femoral in case of fracture:
Craniolateral incision between vastuslateralis+ bíceps femorismusclesextended to tibial crest
-Lateral femoropatellar ligament transect
-Parapatellar arthrotomy + patelar luxation-Reduction + alignment can be difficult
-Metaphyseal part is not visible and is covered by extensive soft tissues on the distal caudal fémur
-Once reduction achieved long screw through exposed intercondylar notch andinto metaphysis to maintain alignment while plate is applied
- Epiphyseal fragment issmall and for this reason à type of flared end in the plate is prefered
85
Describe application of the plate n distal femoral fracture
- Apply lateral plateand afterwards cranialplate
- Use push-pulldevice at either end
- Aplly 5,5 mm cortical screwin proximal and distal ends of the LCP to compress the plate tothe boné
- Once removed push-pulldevice placecortical screws in lag screw principle
- Cranialplate:
-All screws oflateral plate should not be placed before thecranial plate is inserted beneath the rectusfemoris and compressed tothe bone using5,5 mm corticalscrews
- The push-pulldevice cannot be used inthe cranial plate WHY?Quadriceps muscleüIn the more distal andproximal regions stab incisions through thequadríceps musculature are used toallow drill guides or locking drill guides tobe inserted and secured into the plate
-Fill cranial LCP withcortical or locking screws
86
What is the incidence rate of complete pelvic fractures in horses?
0.9% to 4.4%
87
Which horses are more commonly affected by complete fractures of the pelvis?
Foals and yearlings
88
What is a common clinical sign of pelvic fractures in horses?
Swelling or asymmetry of pelvic landmarks
89
How can crepitus in horses with pelvic fractures be better appreciated?
With the horse walking a few steps during a rectal exam
90
What is a diagnostic tool often used for screening pelvic fractures due to the difficulty of obtaining radiographs?
Nuclear scinti
91
What is a typical treatment approach for pelvic fractures in adult horses?
Conservative treatment with stall rest
92
What does the prognosis for soundness after a pelvic fracture depend on?
The degree of displacement and articular involvement
93
What injury can fractures of the tuber coxae often result from?
Blunt trauma
94
What is the usual lameness grade present in horses with fractures of the tuber coxae?
Grade 2 to 4/5
95
How is the lameness in horses with tuber coxae fractures typically observed?
More severe at the walk than the trot
96
What is a recommended diagnostic view for radiographs of the affected tuber coxae?
Medial 50-degree dorsal–lateroventral oblique
97
What is the usual treatment for closed fractures of the tuber coxae?
Conservative treatment with stall confinement
98
What is the prognosis for return to athletic soundness after fractures of the tuber coxae?
Excellent
99
What kind of incision is made for surgical access to the tuber coxae?
Curved from caudodorsal to caudoventral
100
What is the recommended period of stall rest for horses with fractures of the tuber coxae?
A. 30 days
B. 60 days
C. 90 days
D. 120 days
B. 60 days
101
What is a common clinical sign associated with fractures of the tuber coxae?
Swelling and pain on palpation
102
Which imaging technique is particularly useful for diagnosing tuber coxae fractures?
Ultrasonography
103
How are comminuted fractures of the caudal aspect of the tuber coxae typically described?
With caudoventral displacement
104
What is the outcome for horses with complete transverse fractures of the tuber coxae compared to comminuted unicortical fractures?
Longer periods of rest required
105
In the case of open fractures of the tuber coxae, what is often indicated?
Surgical intervention
106
Stress fractures of the pelvis is typical of:
A. Jumping horses
B. Dressage horses
C. Quarter horses
D. THO racing
D. THO racing (but still less than fx tíbia, P1 and carpal)
107
What is the vessel that can bleed and lead to shock and death in a pelvic fracture?
internal iliac artery
108
Ilial wing fracture
109
What is the most affected bone in the pelvis?
Ilial wing > ischium >ilial shaft > acetabulum
110
what is the most common type of pelvic fracture in Thoroughbred racehorses?
Fractures of the ilial wing
111
What is a common observation in horses with ilial wing fractures at the trot?
Shortened cranial phase in the affected limb
112
What is the general diagnostic approach for ilial wing fractures?
Nuclear scintigraphy
113
What is the typical treatment for horses with ilial wing fractures?
Conservative treatment with box stall rest
114
For how long is the recovery of ilal wing fractures?
Hand walking can usually begin during the 3rd month of box stall rest. Small paddock turnout can be introduced in the 4th month. Horses should be monitored with lameness evaluations and repeat ultrasonography or nuclear scintigraphy.
115
How are ilial shaft fractures typically caused?
Traumatic events
116
What is the usual lameness degree in horses with ilial shaft fractures?
Severe
117
What is the preferred treatment for displaced iliac shaft fractures in foals?
Surgical repair
118
What is the prognosis for athleticism after fractures of the pubis and ischium?
Good
119
describe the surgical technique in foals with ilial shaft fracture
The ilium is approached by making an incision from the level of the tuber coxae caudally to the level of the greater trochanter with the incision centered over the ventral third of the ilial body. Bluntly elevate the superficial gluteal musculature by separating them from the ventrally located tensor fascia lata. The middle gluteals are then sharply incised along their ventral attachment to the ilium. Forcefully retract the musculature dorsally with broad Hohmann retractors. The fragments are reduced and securedwith LCPs. In nonarticular fractures, anatomic reduction is not mandatory for a good result. Surgical repair of pelvic fractures in foals is restricted to those with marked displacement and a need for athletic function.
120
Figure 102-9. Preoperative ventrodorsal (A) and lateromedial (B) radiographic views of a 1-month-old foal with an iliac shaft fracture.
121
Ventrodorsal (C) and lateromedial (D) radiographic views following fracture repair using open reduction and internal fixation. Adequate exposure and reduction in larger individuals is enormously difficult. In this case, screws were used to hold the fragment in reduction as the first locking plate was applied to the iliac wing down onto the shaft.
122
What is a common cause of acetabular fractures in horses?
Falls on the side
123
What is the usual treatment approach for acetabular fractures in adult horses?
Conservative management
124
What is the prognosis for non-displaced acetabular fractures?
Good
125
Coxofemoral luxations are more common in which type of horses?
more common in ponies and Miniature horses than in larger equids
126
What is the common clinical sign of coxofemoral luxation in horses?
Severe lameness and external rotation of the limb
127
What surgical technique is used for treating coxofemoral luxation in Miniature horses and ponies?
Reduction and primary repair (modified togle pin reconstruction combined with prosthetic capsular reconstruction for surgical stabilization of coxofemoral luxation) or excision arthroplasty
128
What is a helpful instrument in reducing coxofemoral luxation during surgery?
Hip skid
129
What technique involves placing screws above the cranial acetabular margin for coxofemoral luxation repair?
Synthetic sutures attached to screws
130
Name the reference points for portals of arthroscopy of coxofemoral joint
GA LR upperlimb The arthroscopic portal is located between the cranial and caudal parts of the greater trochanter and approximately 2 cm proximal to the palpable greater trochanter. The joint should be distended before insertion of the cannula/conical obturator unit.
131
In what cases is arthroscopy of the coxofemoral joint indicated?
1. diagnostic arthroscopy in cases with positive intraarticular anesthesia but unclear results on diagnostic imaging
2. septic arthritis
3. tearing of the ligament of the head of the femur
4. osteochondritis dessicans
5. cystic lesions of the femoral head.
132
wha is the surgical approach ot surgically correct the coxofemoral luxation?
craniodorsal approach with or without GT osteotomy
133
name the treatments of coxofemoral luxation in miniatures
1. closed reduction com desmotomy MPL in the first 12 h postinjury
2. excision arthrosplasty - femoral head and neck excision
3. capsule augmentation
3. toggle pin reduction
4. femoral head and neck excision
5. capsulorraphy
6. prosthetic capsule technique
7. total hip arthroplasty
8. combination toggle pin fixation
9. prosthetic capsular reconstruction
transposition of GT of femur
134
can you do closed reduction in coxofemoral luxation?
close reduction may succeed in the first 12 h postrauma, open reduction and some form of stabilization is nearly always necessary
135
describe the surgical steps for correction of coxofemoral luxation in case of osteotomy of the GT
predrill one or two holes to facilitate tension-band repair during closure. Before the femoral head is reduced, the joint is **cleaned of fibrin and any debris**. Any r**emnants of the round ligament are removed**. An effort should be made to avoid any further injury to the dorsal labrum.
Reduction often requires mechanical assistance with either a **calf jack or a pulley system rigged** up in the operating room. A **hip skid,** which is a long levering instrument with a curved spoonlike end, can be helpful in r**educing the luxation**. In most cases, replacement alone is not successful because of continued instability. Therefore, toggle pinning or augmentation of the lateral joint capsule with synthetic sutures attached to screws might be necessary. The latter technique involves placing screws above the cranial acetabular margin and lateral femoral shaft just distal to the neck (Figure 102-10). A large braided suture is tied around the screw heads to help prevent the head from moving proximolaterally. Washers can help to minimize slippage of the suture material from under the screw heads.
136
describe the toggle pin technique in coxofemoral luxation of ponies
The toggle pin technique involves **drilling a hole** from the **lateral proximal femur** aiming up through the **femoral head precisely where the round ligament inserts.** A toggle pin can be made by drilling a hole through the **middle of a 2.5- to 3-cm piece** of a **large-diameter (5–6 mm) Steinman pin**. The edges of the hole must be smoothed to avoid abrasion of the suture material. A three- to five-strand braid of the strongest available nonabsorbable braided suture material (e.g., polyester or, preferably, a polyester/polyethylene composite) is passed through the hole and doubled to a free end. A **hole is then drilled in the acetabulum** at the site of the **round ligament origin.** The toggle with braid attached is inserted vertically through the acetabular hole, and then tension is applied to seat it transversely dorsal to the acetabulum. The braid is then passed down the **hole made at the round ligament insertion** in the** femoral head** and retrieved from its exit point on the** lateral femur.** It is usually necessary to use a wire attached to the braid to pass it down the drill tract. The **braid is then passed through a second toggle pin.** The **femur is abducted** and the tension on the braid is adjusted until it is taut when the hip is allowed to adduct to a normal position. The braid can be tied over the toggle with routine knotting technique because the knot is tied with the limb abducted. The trochanteric osteotomy is repaired with a tension-band technique (screws or pins and wire or cable [see earlier]). The surgeon must be cognizant of the path of the cable through the femoral head and proximal femur so that it is not damaged during the trochanteric repair.
137
Reasons for coxofemoral luxations
YOUNG, MINIATURE, PONIES trauma, upward fixation patella,
FOALS full hindlimb casts, infections
138
Positive outcomes of surigal open reduction in coxofemoral luxations are limited to equids of
230 kgs to date
139
What areas can be seen with the entrace to the coxofemoral joint by the 2 cm proximal to the GT?
Cranial, lateral and caudal articular surfaces
140
describe the surgical acess open reduction and surgical stabilization of coxofemoral luxation in pony using modified toggle pin tx and prothetic joint capsule reconstruction without osteotomy of GT according to Muller 2023
**15 cm curvilinear skin incision **was made in a **proximodistal direction,**
**centered** over the left **coxofemoral joint.** The **superficial gluteal** and **biceps femoris muscles** were separated and** deeper dissection was continued towards the craniodorsal**
aspect of the **great trochanter of the femur.** The **middle gluteal muscle** was retracted dorsally, and the insertion
of the accessory gluteal muscle was transected. **Partial incision of the gluteus profundus muscle** facilitated
exposure of the luxated joint without performing greater trochanteric osteotomy. A **Finochietto wound retractor **was applied to improve access to the affected anatomical
structures.
141
What is a significant risk when creating portals for arthroscopy of the coxofemoral joint?
Damage to the sciatic nerve
142
usually the coxofemoral luxation is
craniodrosal luxation
143
describe the FIRST STEPS before luxation reduction of coxofemoral luxation in pony using modified toggle pin tx and prothetic joint capsule reconstruction without osteotomy of GT according to Muller 2023
First, a **hole was created in the femur **for subsequent **implantation of the toggle pin construct.** For this purpose, a **4.5 mm hole** was** drilled** from a point located **1 cm proximal to the third trochanter** and just **cranial to the caudolateral ridge of the femur** towards the **dorsal aspect of the fovea capitis** of the femoral head with the
help of an **aiming device **(Figure 3A). This hole was enlarged with a **5.5 mm drill bit **and flushed. A **3.2 mm drill hole** was then created **horizontally across the femoral neck** in a c**raniocaudal direction** for subsequent p**rosthetic joint capsule reconstruction**
(Figure 3B). At this stage the **craniodorsal luxation of the femoral
head was reduced** under visual control with aid of the **pulley system** and the left hindlimb fixed in a **physiological neutral position.**
144
FIGURE 3 Initial surgical steps (©Matthias Haab). (A) A hole in the femur for implantation of the toggle pin construct is created with
the help of an aiming device prior to reduction of the coxofemoral luxation. (B) For prosthetic joint capsule reconstruction a 3.2 mm drill
hole is created horizontally across the femoral neck in a craniocaudal direction. (C) The luxation of the femoral head is reduced and three Kwires are inserted parallel to the previously created 5.5 mm drill hole through the femoral neck and head with the limb kept in neutral
position.
145
describe the the implantation of toggle pin in coxofemoral luxation reduction in pony using modified toggle pin tx and prothetic joint capsule reconstruction without osteotomy of GT according to Muller 2023
To continue with implantation of
the toggle pin, **three 1.2 mm K-wires were** inserted parallel to the previously created **5.5 mm drill hole** through the **femoral neck and head**, across the coxofemoral joint and into the acetabulum. The K-wires were crucial to stabilize the femoral head in the acetabulum and counteract
rotational displacement during the following steps of toggle pin implantation. The 5**.5 mm drill bit was reinserted in the 5.5 mm hole** to act as a guide during implantation
of the K-wires (Figure 3C). The **5.5 mm drill bit** was reattached to the drill and advanced through the ac**etabular
medial wall**. The advancement of drilling was performed with care to **avoid penetration of soft tissues axial to the os ileum** (Figure 4D). After lavage of the drill hole, a
**blunt 3 mm pin and a mallet** were used to push the toggle
pin construct t**hrough the 5.5 mm hole until it passed the acetabulum**
(Figure 4E). The toggle pin construct consisted of a **3.0 mm diameter toggle pin** with two multistrand, long chain ultra-high molecular weight polyethylene core (UHMWPE) suture tapes with a braided jacket of polyester (FiberTape and TigerTape; Arthrex GmbH) attached.
The **blunt 3 mm pin** was subsequently removed, and some tension was placed on the construct to ensure that
the toggle pin rotated transversely and was fixed **axial to the acetabulum**. After implantation of the toggle pin
construct, the **1.2 mm K-wires were removed**
146
describe the prosthetic joint capsule reconstruction according to Muller 2023
A prosthetic joint capsule reconstruction was performed
with two additional **3.2 mm holes drilled **through the **cranial and caudal** aspect of the **dorsal acetabulum,** at a distance of approximately **1–1.5 cm to the acetabular rim** (Figure 4F) at the 10:00 and 2:00 o'clock position. **Two USP 5 UHMWPE suture**s with a braided jacket of polyester and UHMWPE (FiberWire; Arthrex GmbH) were first passed **through the holes close to the rim of the acetabulu**m and then through the **hole in the neck of the femur in a figure of 8 pattern **(Figure 5G) with the aid of a nitinol suture retriever (Arthrex GmbH) as well as mosquito forceps. **One figure of 8 **included the **hole at the cranial aspect of the acetabulum** and a **second suture** was placed through the hole in the **caudal acetabulum.**
Both sutures were passed through the same tunnel in the femoral neck to complete the fixation. As the bone around the caudal hole in the acetabulum appeared weak, an anchor suture was added to reinforce stability at the caudolateral aspect of the prosthesis. For this purpose, a **3.5 mm Swivelock PEEK bone anchor
screw** (Arthrex GmbH) was placed at the **lateral aspect of the dorsal acetabular rim,** between the cranial and the caudal holes that had previously been drilled for suture
placement (Figure 5I). FiberWire was attached to the anchor screw and threaded through the hole in the femoral neck in a craniocaudal direction. The s**utures of the capsular prosthesis were tied with surgeon's knot**s and tightened on the lateral aspect of the femoral neck with the limb in an **abducted position.** Finally, the toggle pin suture was tied over a **4-hole 7.5 12 mm butto**n (Arthrex GmbH) to se**cure the pin towards the medial wall of the acetabulum with the limb in neutral position**. During suture tying, tension on the toggle pin construct was controlled by use of a tension device set at 100 N (Arthrex GmbH) (Figure 5H,I).
147
FIGURE 4 Main surgical steps (©Matthias Haab). (D) The 5.5 mm drill bit is advanced across the joint and through the acetabulum
including the axial cortex of the Os ileum. (E) A blunt 3 mm pin and a mallet are used to push the toggle pin construct into the 5.5 mm hole
until it passes the acetabulum. (F) Following removal of the pin, tension is placed on the construct to position the toggle pin axial against the
acetabulum. Two additional 3.2 mm holes are created to complete the prosthetic joint capsule reconstruction, one in the cranial and one in
the caudal aspect of the dorsal acetabulum.
148
FIGURE 5 Final surgical steps (©Matthias Haab). (G) Two FiberWires are passed through the holes close to the rim of the acetabulum
and then through the hole in the neck of the femur in a figure of 8 pattern. One FiberWire passes through the hole at the cranial aspect of
the acetabulum (red suture) and one FiberWire passes through the hole in the caudal acetabulum (blue suture). These sutures serve as a
capsular prosthesis and are tied with the limb in an abducted position. (H) The toggle pin suture (green) is tied over a 4-hole button to
secure the pin towards the medial wall of the acetabulum with the limb in neutral position. A tension device set at 100 N is used to control
the tension on the toggle pin construct as the suture is tied. (I) Final construct showing modified toggle pin technique with prosthetic
coxofemoral joint capsule reconstruction and the additional anchor screw.
149
FIGURE 6 Postoperative
radiographs. (A) Cranioventralcaudodorsal
oblique projection
centered on the coxofemoral
joint showing the femoral head
in the acetabulum. The white
arrowhead indicates the toggle
pin at the medial aspect of the
acetabulum. (B) Right lateral 30
dorsal-lateroventral oblique
projection of the left
coxofemoral joint. The white
arrow indicates the 4-hole
button positioned on the femoral
shaft where the knot at the end
of the toggle pin construct
was tied.
150
FIGURE 1 Craniodorsal luxation of the left femoral head in a
167 kg pony. Note the outward rotation as well as the shortened
appearance of the left hindlimb.
151
(E) The braided strand of suture or cable is passed through the femoral head and outthe side of the femur, where it is secured to another toggle (dotted line). The braided wires between the screw heads in the acetabulum and femoral head are shown.
152
Ventrodorsal (A) and lateromedial (B) radiographic views showing a typical craniodorsal coxofemoral luxation in a Miniature horse
153
Muller et al VS 2022 describe open reduction and surgical stabilization of coxofemoral luxation using what?
modified toggle pin technique and prosthetic joint capsule reconstruction without osteomy of greater trochanter
154
Which technique was NOT used in the surgical procedure Muller et al 2023?
A. Prosthetic capsular reconstruction
B. Osteotomy of the greater trochanter
C. Modified toggle pin technique
D. Use of a pulley system
B. Osteotomy of the greater trochanter
155
How long was the pony placed in a sling post-surgery?
A. 4 weeks
B. 6 weeks
C. 8 weeks
D. 10 weeks
C. 8 weeks
156
What was the pony's weight, which is significant for the surgical procedure?
A. 150 kg
B. 167 kg
C. 200 kg
D. 230 kg
B. 167 kg
157
What was the outcome for the pony two years after surgery?
The pony was sound at walk and tr
158
What complication was observed one week post-surgery in Muller et al 2023?
Thrombophlebitis of the left jugular vein
159
What additional procedure was performed during the surgery to reduce the risk of reluxation in Muller et al 2023?
A. Femoral head ostectomy
B. Medial patellar ligament desmotomy
C. Total hip replacement
D. Acetabular reconstruction
B. Medial patellar ligament desmotomy
160
Craniodorsal luxation of the left femoral head in a167 kg pony.
Note the outward rotation as well as the shortenedappearance of the left hindlimb.
161
What is the radiograph indicated for diagnosis of the coxo-femoral joint?
Right lateral 30º dorsal -lateroventral
162
The reconstruction of the capsule joint is made with which type of suture?
A. Ethibond
B. Vicryl 90
C. FibeWire
D. Surgipro6
C. Fiber wire
163
What is the tension device set to tie the toggle pin suture?
A. 80-100
B. 40-60
C. 20-60
D. 200-220
A. 80-100
164
The coxofemoral luxation is rare in horses due to 2 ligaments, name them
**Round ligament** and **acessory ligament** that restrict range of motion of rotation and abduction
