2. Introduction
Introduction
It should be the surgeon’s to re-establish joint integrity in such
manner, to allow optimal function after healing of an injury.
Unfortunately, in many instances this is not attainable and
degenerative changes limit the horse’s use as an athlete or pleasure
horse. In selected joint disorders, arthrodesis is an alternate
approach to gaining a useful horse despite sacrificing one joint
(.(Auer, 1992
Arthrodesis is a type of ankylosis involving surgical fixation of a joint
by procedures designed to promote fusion of the joint surfaces
(.through promotion of the proliferation of bone cells (Auer, 1992
The development of osteoarthritis in high load-low motion joints
such as the equine proximal inter-phalangeal joint is felt to be the
result of repeated trauma to the periarticular soft tissues. A currently
recommended treatment for this disease is arthrodesis of such joint
•
•
•
•
•

3. Surgical methods of arthrodesis as a •
treatment for osteoarthritis or traumatic
injury include curettage of articular
cartilage of the joint or drilling of
subchondral bone incombination with
AO/ASIF cortical lag screw fixation or Tplate placement followed by cast
immobilization

4. Introduction •
In most cases arthrodesis is carried out to •
salvage valuable breeding stock. There
are certain joints that can be fused without
undully compromising the animal
performance (Auer, 1992(. Such horses
can return to comfort and some to
atheletic soundness after arthrodesis of
the proximal inter phalangeal joint

5. :-Anatomy of proximal interphalangeal (pastern(joint
The pastern (proximal interphalangeal or suffergino-corneal) joint is
a saddle shaped joint. The distal articular surface of the first phalanx
has a shallow sagittal groove separating into medial and lateral
surfaces, both are slightly convex .The corresponding articular
surface on the second phalanx forms a low ridge and two concave
(.surfaces (Nilsson, 1973; Adams, 1974 and Getty, 1975
Owen (1980(; Horne and Lundvall (1981( and McIlwraith (1982(
mentioned that, the articular cartilage of pastern joint is consists of
hyaline type, the matrix of which is a complex of collagenous fibrills
and highly hydrated ground substance containing
mucopolysaccharides and glycoprotein. The collagen fibrils provide
. tensile strength to the articular cartilage
•
•
•

6. :-History of Arthrodesis •
Adams (1970( was the first to describe •
arthrodesis of the proximal inter tarsal,
distal intertarsal and tarsometatarsal joints
as a treatment for spavin but the
technique has remained contraversial
.among equine orthopedic surgeons

8. Osteoarthritis of the distal tarsal joints or bone
spavin is the most frequent cause of lameness
associated with the tarsus A curative treatment
that reverses the degenerative changes and
returns the horse to soundness currently does
not exit. The trasometatarsal (TMT) and distal
intertarsal (DIT) joints of some horses with sever
osteoarthritis will fuse without treatment resulting
in a return to soundness but spontaneous
ankylosis is an inconsistent and lengthy
phenomenon

9. Surgical techniques of arthrodesis involve removing
varying amounts of articular cartilage using a drill bit
(Adams, 1970; Edwards, 1982; Ali, 1984; Wyn-Jones
& May, 1986 and McIlwraith & Turner, 1987( and /or
internal fixation (Mackay and Liddell, 1972; WynnJones & May 1986; Archer et al., 1989 and Abd ElAal, 1998( was conducted. Nevertheless, surgical
arthrodesis is a major procedure that requires general
anaesthesia, is relatively expensive and has a
convalescence period of up to 12 months (Sonnichsen
& Svastoga, 1985 and McIlwraith & Turner, 1987(.
More recently, chemical arthrodesis of the distal hock
joints in the horse using intra-articular sodium
. monoiodoacetate has been attempted
•

10. SMIA is reported to produce a reliable, diffuse and sever
insult to the articular cartilage after intra-articular
injection. SMIA is a potent inhibitors of glycolysisdependent chondrocytes and had been used extensivly
to produce experimental model of osteoarthritis which
will ultimately result in ankylosis (Williams and Brandt,
1982 and Yovich et al., 1987(. A further possible
mechanism by which SMIA may enhance arthrodesis is
that results in reduced cartilage chondrone formation
(Bohanon et al., 1991(. Chondrones are thought to
delay the ankylosing process by forming persistent
cartilage bridges between the joint surfaces (Auer,
1999(. Therefore reduced chondrone formation may lead
.to potentially more effective arthrodesis

11. Sodium monoiodoacetate (SMIA) is a •
chemical compound, when injected intraarticularly, causes a rapid decrease in
chondrocyte intracellular adenosine
triphosphate concentration resulting in
inhibition of glycolysis, chondrocyte death,
partially necrosis, joint collapse and fusion

12. Martin et al., (1984( said that, arthrodesis •
are performed in low motion joints
especially pastern joint for a return to
performance in situations where treatment
of the arthritis is not successful or in
which, treatment has gradually become
overpowered by the progression of the
.degeneration

13. Moore and Withrow (1981( and Newton •
and Nunamaker (1984( stated that,
arthrodesis is an elective surgical
procedure to eliminate motion in a joint by
providing a bony fusion to relieve pain,
provide stability, over coming postural
deformity resulting from neurologic deficit
.and to control advancing disease

14. Schneider, Carinine and Guffy (1978(; •
Trotter, McIlwraith, Norrdin and Turner
(1982(; Ellis and Greenwood (1985( and
Adams, Honnas and Ford (1995(
mentioned that, arthrodesis of the
proximal interphalangeal joint (PIPJ) is
used in treating degenerative joint disease
(DJD), luxations, subluxations and fracture
of proximal and middle phalanges

15. the proximal interphalangeal joint is a •
common site for DJD (high ring bone). It
can occur as a sequela to a severe sprain
of the pastern or a deep wire cut in the
pastern region

16. Raker (1962); Schneider et al., (1978); Auer, •
Fackelman and Gingerich (1980) and
McIlwraith (1982) defined osteoarthritis or
degenerative joint disease as a disease of
diarthrodial joints comprising destruction of
articular cartilage to varying degrees,
accompanied by subchondral bone sclerosis and
marginal osteophyte formation. Synovitis and
joint effusion often are associated with the
disease. They added that, the disease is
characterized by pain and dysfunction of the
affected joints

17. Trotter et al., (1982); Ellis et al.,(1985) •
and Pool (1996) reported that the
development of osteoarthritis in high-load
low motion joints such as the equine PIPJ
is felt to be the result of repeated trauma
to the periarticular soft tissues. A currently
recommended treatment for this disease
.is arthrodesis of such joint

18. Olds (1975); Moore et al., (1981) and •
Newton et al., (1984) mentioned that
septic arthritis, degenerative joint diseases
and rheumatoid arthritis may result in joint
instability, pain or both often when medical
or conservative surgical means prove
unsuccessful, arthrodesis is the only
.solution

19. Vansalis (1972); Adams (1974); Johnson •
(1974); Olds (1975); Schneider et al.,(1978);
Fessler and Amstutz (1988); and Auer (1991)
mentioned that the non-surgical treatment for
osteoarthritis especially the articuler type has
been unsuccessful but ankylosis relieves pain by
preventing joint movement. McIlwraith and
Bramlage (1996) added that arthrodesis
performed in acute joint disruptions noted with
.fractures of the proximal and middle phalanges

20. Early et al., (1966); Olds (1975); Wind(1975); •
Dee, Dee and Early (1984) and Steenhaut,
Verschooten and DeMoor (1985) mentioned
that, orthopedic indications for an arthrodesis
include chronic instability or subluxation not
amenable to reconstructive procedure, painful
arthritis not responsive to medical therapy and
certain fractures of the middle phalanx that don’t
.involve the distal inter-phalangeal joint

21. Arnolds (1985) reported that the most common
indications for arthrodesis in veterinary medicine divided
into traumatic, developmental and congenital. He added
that traumatic injuries to joint consists of both fractures
and ligamentous disruptions with or without dislocation,
in which a primary repair lead to chronic instability or
DJD and pain. Newton and Nunamaker (1985)
mentioned that, the major developmental diseases can
be included under the heading arthritis that further
subdivided into idiopathic or secondary DJD, septic
arthritis and immune mediated arthritis. The same
authors added congenital diseases as congenital elbow
luxations and stifle deformities that are not amenable to
.primary reconstruction
•

22. Olds et al., (1975); Johnson and •
Bellenger (1980) reported that arthodesis
indicated for the treatment of sever
ligament sprains, sever joint trauma and
intra-articular fractures

23. Proximal inter-phalangeal joint athrodesis has been
indicated in osteochondritis dessicans (OCD) Trotter et
al., (1982) subchondral cystic lesions (Steenhaut et
al.,1985) phalangeal deviations in foals (Schneider,
Guffy and Leipold 1987) and flexural deformities
(White hair, Adams and Toombs 1992). Yovich,
Stashak and Sullins (1986); Bukowiecki and
Bramlage (1989) and Caron, Fretz and Bailey (1990)
mentioned that lameness caused by DJD of pastern joint
and comminuted middle phalangeal fracture has been
.treated successfully in horses by surgical arthrodesis
•

24. Adams (1974) and Fessler and •
Amastutz (1988) stated that most non
surgical treatment of osteoarthritis
especially the articular type have been
unsuccessful but ankylosis relieves pain
.by preventing joint movement

25. Raker, Raker and Wheat (1966); Adams (1974); Whittick (1974);
Olds (1975); DeAngelis (1975); Moore et al., (1981) and Newton
et al., (1984) said that prior to the development of prosthetic joints
for human beings, arthrodesis was a common surgical procedure for
osteoarthritic joints in various parts of the body. The surgical
principle that are necessary to achieve arthrodesis of joints include
the removal of all articular cartilage and sub-chondral bone until
bleeding subchondral cancellous bone is reached. They added that
the sub chondral cancellous surfaces are approximated and bound
by rigid internal implants. Autogenous cancellous bone graft is
desirable in any defect between the two opposing bones which
serves as a scaffold for in growth of new vessels from each of the
.opposing bones
•

26. Adams (1970); Bramlage (1982) and Turner (1984) said that the
articular cartilage of opposing bones should be removed for
achievement of an effective arthrodesis in the shortest time. If the
bone ends are sclerotic as a result of a diseased process they must
be removed to achieve formation of new tissue in the defect and
good ankylosis. While, Auer (1999) suggested that the cartilage
was not removed from the proximal interphalangeal joint (PIPJ)
during the experimental procedure. It has been proposed that
removal of cartilage will alter the radii of the opposing bones. He
added that the distal end of the proximal phalanx will be reduced
and the proximal end of the middle phalanx will be decreased
following curettage of articular cartilage. Although cartilage removal
is strongly recommended for arthrodesis to progress rapidly in the
.clinical cases
•

27. Whittick (1974); Olds (1975); DeAngelis (1975) and
Auer (1992) observed that any defect not filled with
cancellous bone would first filled with fibrous connective
tissue, then changed into osteoblastic tissue, thus
delaying complete ankylosis and external support is
required until radiographic evidence of early fusion is
seen.Review of Literature
Rick, Herthel and Boles (1986) reported that the use of
an autogenous cancellous bone graft can substantially
reduced the time of osseous union following arthrodesis.
However the presence of cancellous bone between the
proximal and the middle phalanges can adversely affect
.the degree of contact between the subchondral plates
•
•

28. Adams (1974) used a joint drilling procedure, removing as much of
the articular cartilage then packing the joint with cancellous bone
harvested from a different sites. Other techniques of arthrodesis
employ a more radical approach to the joint utilizing a variably
shaped skin incision and a transection of the dorsal joint capsule of
the pastern joint and curettage of articular cartilage followed by
support of the joint in a fiber glass cast (Turner and Gabel 1975;
Turner 1984 and Stashak 1987). Alternatively, the method of lag
screw fixation either in criss-crossing or paralled procedure as
described by Schneider et al., (1978) can be used. Surgical
techniques of arthrodesis involves removing varying amount of the
articular cartilage using a drill bit (Adams 1970; Edwards 1982;
Wyn-Jones and May 1986, and McIlwraith & Turner 1987) and
/or internal fixation (Mackay & Liddell 1972 and Archer,
).Schneider, Lindsay and Wilson 1989
•

29. Surgical arthrodesis has an over all •
success rate of about 80% (Auer, 1992).
The current recommended surgical
arthrodesis technique which involves
placement of three drill holes across each
joint of distal tarsal joint, is associated with
minimal post-operative complications and
pain (McIlwraith and Turner 1987). The
same authors preferred this technique in
the PIPJ

30. Different methods of arthrodesis of the PIPJ have been
described and include curettage of articular cartilage
(Adams 1974; Gabel and Bukowiecki 1983 and
Boran, White and Allen 1987) insertion of lag screws
either by paralled or criss-crossing procedure
(Schneider et al., 1978; Genetzky, Schneider, Butler
and Guffy 1981; Grant 1982; Gabel et al., 1983 and
Yovich et al., 1986), application of a dynamic
compression plate (DCP) or specially designated T-plate
(Fackelman and Nunamaker 1982; Bramlage 1985
and Boran et al., 1987), sliding grafting technique
(Fackelman Nunamaker 1982) and combinations of the
above methods. All techniques are completed after
removing articular cartilage and all involve the use of
.post- operative cast
•

31. Baumberger and Lakatos (1977); Steenhaut •
et al., (1985) and Auer (1992) mentioned that
surgical methods of pastern arthrodesis as a
treatment for osteoarthritis or traumatic injury
include curettage of the articular cartilage or
drilling of the subchondral bone in combination
with cortical screw fixation with lag effect or Tplate placement followed by immobilization.
They added that, immobilization with out
complete curettage of cartilage lead to ankylosis
without osseus union

32. Several methods of internal fixation have provided
successful fusion of the PIPJ. after exposure of joint
surfaces and curettage of the articular cartilage, two
screws in a cruciate orientation inserted with lag effect
(Schneider et al.,1978 and Genetzky et al., 1981),
three screws placed with lag effect in parallel orientation
(Colahan, Wheat and Meagher 1981; Martin et al.,
1984, Steenhaut et al.,1985; Caron, Fretz, Bailey and
Barber 1990 and Schneider, Bramlage and Hardy
1993), a single T-plate (Steenhaut et al., 1985; Rick et
al., 1986 and Auer,1992) and one or two dynamic
compression plate (DCPs) placed across the dorsal
aspect of the joint (Auer, 1992; Crabill, Watkins and
).Schneider 1995 and McIlwraith et al., 1996
•

33. Arthrodesis of the PIPJ was •
recommended as the best method of
treatment of comminuted fractures of the
middle phalanx by application of a T-plate
(Boran et al., 1987), a narrow dynamic
compression plate (Doran et al., 1987),
use of a broad dynamic compression plate
(BukoWiecki and Bramlage 1989) or two
narrow dynamic compression plate

34. Adams (1974) mentioned that fusion of the PIPJ •
in horse was done by drilling from the lateral
aspect of the joint and packing it with a
cancellous bone graft while, Johnson (1974)
used the electrically stimulating fragmented
ends after arthrodesis of the PIPJ. to decrease
the necessary for ankylosis and minimize
extraarticular bony proliferation. The later author
utilized electrical currents to create an electrical
effect to hasten bony union between the
. proximal and middle phalanges

35. Other technique aimed compression of the pastern joint with cortical
screws were investigated by Vansalis (1972), Schnieder et al.,
(1978) and Mansmann et al., (1982) they stated that the technique
of arthrodesis is begin by exposure of the PIPJ from its dorsal
aspect to ensure more thorough removal of the articular cartilage.
The common (or long) digital extensor tendon was severed by an
inverted V-shape (Schneider et al., 1978) or by a Z-plasty
(Mansmann et al., 1982), the joint capsule is transversely incised
by sharp dissection. The collateral ligaments were severed to allow
exposure of the joint. Following arthrotomy a periosteal elevator is
used to pry the joint surface apart for optimal exposure of hyaline
cartilage. A curette or drill is used to remove as much cartilage from
the bone end as possible. AO/ASIF cortical lag screws were placed
in the joint to achieve greater stability and shorten the period of
.healing
•

36. One of the most description of pastern arthrodesis utilizing a dorsal
approach to the joint. Curettage of articular cartilage and the
compression of the joint surfaces by cortical screws through the
proximal into the middle phalanx using the lag principle (Schneider
et al., 1978 and Genetzky et al., 1981). They found that placement
of three cortical screws crossing the pastern joint nearly parallel to
the long axis of the phalanges creates a stronger union during the
first 120 post operative days than the diagonal insertion of two
screws criss-crossing the joint. While, the latter author found that the
criss-cross procedure would be useful for arthordesis of the PIPJ
after the transverse fracture of the second phalanx than the parallel
procedure because the criss-cross screws penetrate the second
phalanx dorsal to the area of the fracture
•

37. Maclellan (2001) concluded that an •
arthrodesis technique using two 5.5mm
AO/ASIF cortical lag screws in parallel
procedure results in favorable outcome in
fore and hind limb PIPJ. The technique
has another advantage of decreased
.surgical and coaptation time

38. Carnine and Guffy (1978) showed that method of lag
screw fixation is preferred than the curettage of the joint
cartilage followed by support of the joint in a fiberglass
cast as a techniques for arthrodesis of PIPJ. The
convalescent time and cost of hospitalization can be
reduced because the cast can be removed earlier, since
the joint is inherently more stable owing to the lag
screws. They added that the cast left on for an average
of 23 days, after that time, it was removed for
radiographic evaluation of the joint, then a cast was
reapplied, if it was felt that the arthrodesis needed further
.support
•

39. Fackelmann and Nunamaker (1982) •
described other surgical procedure
leading to fusion of the PIPJ using plates
and screws. The joint was fixed by Tplate contoured to confirm to the anterior
surface of the first and second phalanges.
The operated limb was placed in a cast
from the carpus or tarsus to the hoof. The
.horse was rested for a total of 12 weeks

40. Watt, Edward, Markel and Wilson (2001) compared the
biomechanical characteristics and mode of failure of two different
screws techniques (3 parallel 4.5mm cortical screws and 2 parallel
5.5mm cortical screws in lag fashion) in equine PIPJ arthrodesis.
They observed that 3 parallel 4.5mm cortical screws placed in lag
fashion have been an accepted standard for PIPJ arthrodesis in the
horse.Two 5.5 mm screws have been shown here to be
biomechanically similar to three 4.5mm screws. They believed that,
it is surgically simpler to implant two 5.5mm screws than three
4.5mm screws. The same authors in (2002) compare the
biomechanical characteristics and mode of failure of two different
dynamic compression plates (two 7 holes 3.5mm broad DCPs and
two 5 holes4.5mm narrow DCPs) techniques for PIPJ arthrodesis in
horses. They advised that the latter technique is more preferable
than the former one
•

41. Sodium monoiodoacetate ( MIA ) is a chemical
compound which, when injected intra-articularly causes
a rapid decrease in chondrocyte and intracellular
adenosine triphosphate concentrations resulting in
inhibition of glycolysis and chondrocyte death
(Sorimarchi & Nishimura, 1983; Berding &
Mikhailov, 1983; Saito & Yamaguchi, 1985 and Tread
Well & Mankin, 1986). MIA has been used
experimentally as a glycolysis blocking agent to create
arthritis in rats (Kalbhen 1981), guinea pigs (Williams &
Brandt, 1982), chicken (Stick, Slocumbe and
Personnett 1984) and horses (Buchmann & Kalbhen
1985 and Yovich, Trotter, McIlwraith and Norrdin
. )1987
•

42. Review of Literature •
Bohanon, Schneider and Weisbrade (1991) •
and Bohanon (1995) reported a process of
arthrodesis of distal tarsal joints by intra-articular
injection of MIA which compared favorably with
surgical one this technique has been suggested
as a simple, cheap and easier than the latter
.one
Penraat, Allen, Fretz and Bailey (2000) •
reported that chemical arthrodesis can not be
advocated in clinical cases because of high
.complication rate and lack of bony fusion

43. Experimental arthrodesis in horses using MIA has been
investigated by Bohanon et al., (1991) who found that a
series of three injections of 120 mg of MIA into the
pastern joint with 10 days intervals would produce an
average 80.5% joint fusion in 3 month with unfused
areas of the joint showing potential for fusion. The same
author in addition to Bohanon (1995) found that the
second and third injections of MIA revealed difficulties
not encountered on the first injection. Although the
needle was inserted to its maximum depth, high
pressure was required to inject into the intra-articular
space. A soft tissue swelling from pervious injections
increased the distance from the skin to the intra-articular
.space
•

44. Recently, chemical arthrodesis of the PIPJ through intra-articular injection of
120mg of MIA has been introduced as a treatment for DJD. Pronounced
synovitis after injection by 12 to 24 hours which is managed with sedation
and analgesia with detomidine and phenylbutazone before injections
).(Schneider, 1997
Penraat et al., (2000) studied the use of MIA for arthodesis of the PIPJ and
the effect of exercise on the degree of fusion in eight horses. Animals
received three injections with 10 days intervals of MIA (6% ,60 mg /ml) at a
dose of 120 mg into the right or left fore PIPJ, perioperatively, the horse
received phenylbutazone and low volar never blocks to relive pain. Horses
were randomly divided into non-exercised and exercised groups. Exercise
consisted of 20 minutes of trotting 3 days per week for 13 weeks. The
horses were killed at 24 weeks, slab sections of the joint were evaluated
grossly and radiographically for bony fusion. They found that three horses
were excluded from the study after developing soft tissue necrosis around
the injection site, septic arthritis and necrotic tendonitis. The remaining
horses developed a grade 1 to 4 lameness with minimum to sever swelling
in the pastern region. All 5 horses showed radiographic evidence of bony
.fusion
•
•

45. Review of Literature •
Williams & Brant (1984); Yovich et al., •
(1987); Bohanon et al., (1991) and
Bohanon (1995) mentioned that MIA
blocks a specific enzyme pathway in
chondrocyte metabolism, resulting in
chondrocyte death, cartilage necrosis,
.joint collapse and fusion of it

46. Prognosis & complications of
:-pastern joint arthrodesis
•
Martin et al., (1984) and Caron et al., (1990) •
reported that the success of arthrodesis of the
proximal interphalangeal joint was 46% in fore
limbs and 83% in hind limbs using a technique
involving a three screws in converging pattern.
While Schneider et al., (1993) reported that the
success of arthrodesis was 67% in the fore limbs
and 86% in hind limbs. Rick et al., & Yovich et
al., (1986) described a successful cases of
.bilateral arthrodesis in the fore and hind limbs

47. Schneider et al., (1978) and Genetzky et al., •
(1981) compared transarticular screws
techniques using three paralled 4.5mm screws
or two cruciate 4.5mm screws, result of
comparison revealed that, the paralled
procedure created a functional soundness and a
superior union between the first and second
phalanges during the first 120 days postoperatively. It was easier than the diagonal
insertion of the two screw crossing the joint,
produced better alignment and was less prone to
.error in screws placement

48. Review of Literature
Doran et al., (1987); Bukowieki et al., (1989); Caron et al., (1990)
and Crabill (1995) mentioned that the prognosis for horses having
arthrodesis to intra-articular fractures or active sepsis has not been
reported in large numbers of cases, however, the prognosis for
treatment of fractures that involve only the PIPJ has been assumed
. to be similar to that for DJD
Genetzky et al., (1981) and Martin et al., (1984) mentioned that
the complications following PIPJ arthrodesis in horses include
radiographic evidence of navicular disease, degenerative disease
involving the distal inter phalangeal joint and toe-elevation at the
beginning of the weight bearing. Other complications related to open
reduction and internal fixation include infection, and implant
. associated lameness
•
•
•
•

49. Nixon et al., (1984) reported that implant associated
lameness is likely to occur if a screw penetrates distally
on the palmar or plantar cortex of the middle phalanx
and encroaches on the navicular bone articulation,
furthermore, even a properly positioned screw that is too
long can cause persistent irritation to the soft tissue
structures and result in lameness. Toe-elevation occur
due to damage to the deep flexor tendon. The same
authors in addition to Bramlage (1992) reported other
complications of PIPJ arthrodesis as low true ring bone,
screw breakage, excessive formation of callus and
fracture of the small shelf created on the distal end of the
proximal phalanx. All which produced continued
.lameness
•

50. Review of Literature •
Bramlage (1992) said that, the most significant •
complications associated with arthrodesis was
laminitis in the opposing limb which is influenced
by the lack of comfortable weight bearing in the
injured limb. Martin et al., (1984) added that
lameness associated with excessive periarticular
exostosis and increased period in cast were
other complications of pastern joint arthrodesis
.in horses