**3. Results and discussion**

154 A Bird's-Eye View of Veterinary Medicine

visualization of the synovial membrane, the lateral femur condyle, the long digital extensor tendon, the intercondylar fossa, the tibial plateau, the menisci, the intermeniscal and cruciate ligaments, the medial compartment, the medial femur condyle, the femoropatellar joint (articular surfaces of femur and patella, trochlear ridges), and the suprapatellar pouch. A second cutaneous and capsular incision was performed in the medial parapatellar region for introducing the arthroscopic scissor, as mentioned above. The CrCL was sectioned, remaining the intra-articular stumps. The CrCL section was confirmed by direct visualization by arthroscopy, and by the test of cranially dislocating the tibia in relation to the femur. The animals were kept in individual 4.5m² cages, for 21 days, and, after that period, submitted to new arthroscopic examination. Synovial fluid was collected, and the joint cavity was distented as described above. The intra-articular structures were systematically evaluated, as previously described, and the alterations found in the soft and in the hard tissues were documented . The images were analyzed based on the arthroscopic findings on Day 0, when the first arthroscopy was performed followed by the CrCL rupture, and at Day 21, when a new arthroscopy was conducted for evaluating the articular lesions. The structures were also individually evaluated, and abnormalities were registered. According to their quantity and aspect, villi were classified (Tab.1) from 1 to 4; grade 1 represented absence of lesion and 4, severe lesion. The villi were also morphologically classified as: filamentous, thin, interlaced, short, and as polyp, staff, fringe, bush, fan, and cauliflower shapes. In addition, they were categorized in respect to their localization: lateral and medial compartments, patellar ligament, and patellar tendon. The presence or absence of intra-articular fibrous cords was taken into account. Additionally, the articular cartilage was evaluated by area: patella, suprapatellar pouch, trochlear surface, intercondylar fossa, medial and lateral femur condyles, trochlear ridges of the femur, and surface of the tibia condyles. Likewise, the presence of osteophytes

Villi of the synovial membrane

3 Moderate: thin, filamentous, short, in the shapes of polyp, fan, bush, and staff

4 Severe: numerous villi, dense in the shapes of cauliflower, fringe, located mainly

Vascularization of the synovial membrane

2 Mild: discrete presence of ingurgitated vessel in up to two regions. 3 Moderate: vascularization, apparent hyperemia at the lateral and medial

compartments, cruciate ligaments, and menisci. 4 Severe: hypervascularization, hyperemia of the lateral and medial compartments, menisci, and ligaments; articular hemorrhage. Table 1. Scores system for the synovial membrane characteristics evaluated by stifle joint arthroscopy on Days 0 and 21 after section of the cranial cruciate ligament (CrCL).

at the lateral and medial compartments; with hemorrhagic aspect and reddish

was classified according to the scores in Table 2.

2 Mild: thin, filamentous, and short villi; white or rosy.

Score Description 1 Absent.

villi; reddish.

color.

Score Description 1 Absent.

The arthroscopic examination was possible in both evaluation moments, and, as described by Person (1985), systematic examination of the joint allowed the ordering of the results (Tables 3 and 4). All structures that were visualized on Day 0 were also seen on Day 21, when it was possible to detect, in 100% of the joints, alterations in relation to Day 0, fact that was expected given the joint instability, however, statistical significance was noticed in 83.3% (Table 5). The parapatellar approach was adequate for evaluating all the articular structures or regions in this study, as well as for sectioning the CrCL. The positioning of the animal allowed flexion, extension, *varus* and *valgus* movements, and rotation of the joint during the procedure, facilitating the detailed arthroscopic examination, as reported in literature (Van Ryssen & Van Bree, 1998; Arias et al., 2003; Beale et al., 2003; Melo et al., 2003; Rezende et al., 2006, Borges, 2006).


Arthroscopic Follow-Up After Rupture of the Cranial Cruciateligament 157

Vascularization 6.00 0.181

6.00 0.181

No variability3

0.500 0.050

1.000

0.005 0.089

Structure Region Alteration Wilcoxon P-value

tion Villi

Structure Region Wilcoxon P-value

Suprapatellar pouch

Intercondylar fossa Lateral femoral condyle Medialfemoral condyle Tibia

Lateral trochlear ridge Medial trochlear ridge

1All the observed differences were equal to 0, thus no lesion was observed on Days 0 and 21.

21, after arthroscope-guided section of the cranial cruciate ligament (CrCL).

Table 4. Wilcoxon test for osteophyte presence, observed on Days 0 and 21, at the stifle joint of dogs submitted to arthroscope-guided section of the cranial cruciate ligament (CrCL).

Dog 1 2 3 4 5 6 7 8 9 Wilcoxon 120 3 113 15 105 66 66 21 21 P-value 0.001 0.371 0.003 0.059 0.001 0.004 0.004 0.036 0.036 Dog 10 11 12 13 14 15 16 17 18 Wilcoxon 28 21 91 91 105 66 10 15 55 P-value 0.022 0.036 0.002 0.002 0.001 0.004 0.100 0.059 0.006 Table 5. Individual analysis of the intra-articular lesions of dogs, evaluated on Days 0 and

Patella

Trochlea

1 All the evaluated differences were equal to 0, thus no lesion was observed on Days 0 and 21. 2 All the evaluated differences were equal to 0, thus no lesion was observed on Days 0 and 21, except

one dog, which already presented lesion before the rupture that persisted after the 21-day period. 3 All the evaluated differences were equal to 0, thus no lesion was observed on Days 0 and 21, except one dog, which already presented lesion before the rupture that persisted after the 21-day period.

Table 3. Wilcoxon test for the different lesions, observed between Days 0 and 21, at the stifle joint of dogs submitted to arthroscope-guided section of the cranial cruciate ligament

> 1.00 10.00

1.00

45.00 13.00

No variability1 No variability1

No variability1 No variability1

Neovasculariza-

Caudal cruciate ligament

(CrCL).

Articular cartilage

Long digital extensor tendon



10.00 45.00

6.00 3.00

3.00 10.00

55.00 36.00

21.00 21.00

10.00 1.000

6.00 1.00

10.00 0.100

Vascularization 10.00 0.100

No variability1

No variability1

No variability1

No variability1

No variability1

No variability1

No variability2

No variability1

No variability1

No variability1

0.100 0.009

0.181 0.371

0.371 0.100

0.006 0.014

0.036 0.036

0.100 1.000

0.181 1.000

Structure Region Alteration Wilcoxon P-value

Fibrillation Vascularization

Fibrillation Vascularization

Fibrillation Vascularization

Fibrillation Vascularization

Fibrillation Vascularization

Fibrillation Vascularization

Fibrillation Vascularization

Erosion Fibrillation Vascularization

Erosion

Erosion

Erosion

Erosion

Erosion

Trochlea Erosion

Tibia Erosion

Patellar pouch

Intercondylar fossa

Lateral femoral condyle

Medial femoral condyle

Lateral trochlear ridge

Medial trochlear ridge

Medial meniscus

Lateral meniscus

Cranial cruciate ligament


1 All the evaluated differences were equal to 0, thus no lesion was observed on Days 0 and 21. 2 All the evaluated differences were equal to 0, thus no lesion was observed on Days 0 and 21, except one dog, which already presented lesion before the rupture that persisted after the 21-day period. 3 All the evaluated differences were equal to 0, thus no lesion was observed on Days 0 and 21, except one dog, which already presented lesion before the rupture that persisted after the 21-day period.



1All the observed differences were equal to 0, thus no lesion was observed on Days 0 and 21.

Table 4. Wilcoxon test for osteophyte presence, observed on Days 0 and 21, at the stifle joint of dogs submitted to arthroscope-guided section of the cranial cruciate ligament (CrCL).


Table 5. Individual analysis of the intra-articular lesions of dogs, evaluated on Days 0 and 21, after arthroscope-guided section of the cranial cruciate ligament (CrCL).

Arthroscopic Follow-Up After Rupture of the Cranial Cruciateligament 159

1 2 3 4

5 6 7 8

9 10 11 12

13

Fig. 1. Arthroscopic images of the stifle joint of dogs submitted to experimental section of the cranial cruciate ligament (Days 0 and 21) guided by arthroscopy. 1) Articular surfaces of the patella (PA) and trochlea (TC) of the femur without alterations; 2) Synovial membrane of

On Day 21 after CrCL section, at the arthroscopic examination, alterations suggesting articular degenerative process came to evidence. The arthroscopy, as mentioned by Adamiak (2002), is effective in precisely diagnosing the CrCL rupture and evaluating the

evolution of the degenerative lesions of the joint, fact that was verified in this study.

the lateral compartment with filamentous villi ( arrow), lateral condyle of the femur ( arrow); 3) Synovial membrane (MS) with discrete hyperemia at the medial compartment; 4) Blood vessel along of the cranial cruciate ligament (LCCr), caudal cruciate ligament(LCCd); 5) Meniscofemoral ligament (arrow); 6) Lateral compartment showing the lateral femoral condyle (LFC), long digital extensor tendon (arrow) and lateral meniscus (LM) 7) Origin of the popliteus muscle tendon(PT); 8) Intercondylar fossa with thin villi, stump of the cranial cruciate ligament showing nodular formation on the end of the torn ligament (arrow); 9) Villi in the shape of filamentous at the lateral compartiment; 10) Villi in the shape of polyp (arrows) at the medial compartment, medial femoral condyle (MFC); 11) Villus in the shape of fringe(arrows), lateral femoral condyle (LFC); 12) Villus in the shape of fan (arrow), lateral femoral condyle (CLF); 13) Lateral compartment showing villi in the shape of staff

(arrow).

It was possible to precisely evaluate the menisci, the intermeniscal ligament, the synovial membrane, the articular cartilage, the cruciate ligaments, and the long digital extensor tendon by arthroscopy, as described in the literature (Van Ryssen & Van Bree, 1998; Adamiak, 2002; Beale et al., 2003; Borges, 2006). The precision offered by the arthroscopic examination is reported by distinct authors (Sams, 2000; Adamiak, 2002; Arias et al., 2003; Beale et al., 2003; Melo et al., 2003; Rezende et al., 2006; Beale & Hulse, 2010). Subcutaneous infiltration of liquid was not observed. Depending on the intensity of infiltration, capsule distension is impaired, and the examination becomes unviable (Van Ryssen et al., 1993). The arthroscopy showed itself as an effective method for evaluating the degenerative alterations after experimental CrCL section. According to Lipowitz et al. (1985) and Lewis et al. (1987), the CrCL section is accepted as the best model for the experimental induction of degenerative lesions. This result was observed in this study, with the additional advantage of direct visualization and magnification of image by arthroscopy, which allowed the evaluation of joint instability, as already reported by others (Lipowitz et al., 1985; Johnson & Johnson, 1993; Glyde et al., 2002; Hulse et al., 2010; Bleedorn et al., 2011). According to Arnoczcky & Marshall (1977), the degenerative process begins one week after CrCL rupture; thus, the articular evaluation on Day 21 is able to identify macroscopic lesions precociously, as observed in this study.

Signs of articular degeneration and inflammation could be noticed at the arthroscopic examination. According to Bennett & May (1997) and Vaughan-Scott & Taylor (1997), the unavoidable DJD progression can be mostly attributed to the enzymatic degradation of the articular cartilage.

For each dog, 14 areas or structures were evaluated by arthroscopy, in a total of 504 individual evaluations. On the day of the CrCL section, 17 dogs (94.4%) presented shining and smooth surfaces of femur and patella, without periarticular osteophytes (Fig. 1.1). Only in one animal (5.6%), irregularities at the trochlear ridge were detected.

From 18 evaluated joints, eight (44.4%) had villous proliferation of thin and filamentous types (Fig. 1.2), considered normal according to McIlwraith & Fessler (1978) and Lewis et al. (1987). In one animal, these villi were hyperemic, and, in nine, the synovial membrane was smooth, without villi. In all the cases, the villi were located at the medial compartment. McIlwraith & Fessler (1978) reported that, in normal articulations, the thin, filamentous, and polyp-shaped villi are commonly observed in equines. Similar findings were reported in dogs (Lewis et al., 1987). Joint with normal villi, but with evident hyperemia suggests inflammatory process, and once the villous type is considered normal, it is possible to infer that the process is at an initial phase.

Discrete hyperemia of the synovial membrane was observed in 17 (94.4%) dogs on Day 0 (Fig. 1.3), during the procedure that lasted 15 minutes on average. Due to the absence of dense fibrous tissue in the synovial membrane, increased local irrigation with congestion and swelling can develop during prolonged arthroscopic procedure (Lewis et al., 1987; Kurosaka et al., 1991), what may explain the findings of this work, not being, necessarily, synovial inflammation. In 14 dogs, the presence of blood vessels (Fig. 1.4) was observed along the CrCL. Despite these alterations in vascularization, the CrCL was intact and shining on Day 0, as well as the caudal cruciate ligament, the meniscofemoral ligament (Fig.1.5), and the long digital extensor tendon (Fig. 1.6). The origin of the popliteus muscle tendon was visualized in two animals (Fig. 1.7), and presented no alteration.

It was possible to precisely evaluate the menisci, the intermeniscal ligament, the synovial membrane, the articular cartilage, the cruciate ligaments, and the long digital extensor tendon by arthroscopy, as described in the literature (Van Ryssen & Van Bree, 1998; Adamiak, 2002; Beale et al., 2003; Borges, 2006). The precision offered by the arthroscopic examination is reported by distinct authors (Sams, 2000; Adamiak, 2002; Arias et al., 2003; Beale et al., 2003; Melo et al., 2003; Rezende et al., 2006; Beale & Hulse, 2010). Subcutaneous infiltration of liquid was not observed. Depending on the intensity of infiltration, capsule distension is impaired, and the examination becomes unviable (Van Ryssen et al., 1993). The arthroscopy showed itself as an effective method for evaluating the degenerative alterations after experimental CrCL section. According to Lipowitz et al. (1985) and Lewis et al. (1987), the CrCL section is accepted as the best model for the experimental induction of degenerative lesions. This result was observed in this study, with the additional advantage of direct visualization and magnification of image by arthroscopy, which allowed the evaluation of joint instability, as already reported by others (Lipowitz et al., 1985; Johnson & Johnson, 1993; Glyde et al., 2002; Hulse et al., 2010; Bleedorn et al., 2011). According to Arnoczcky & Marshall (1977), the degenerative process begins one week after CrCL rupture; thus, the articular evaluation on Day 21 is able to identify macroscopic lesions precociously,

Signs of articular degeneration and inflammation could be noticed at the arthroscopic examination. According to Bennett & May (1997) and Vaughan-Scott & Taylor (1997), the unavoidable DJD progression can be mostly attributed to the enzymatic degradation of the

For each dog, 14 areas or structures were evaluated by arthroscopy, in a total of 504 individual evaluations. On the day of the CrCL section, 17 dogs (94.4%) presented shining and smooth surfaces of femur and patella, without periarticular osteophytes (Fig. 1.1). Only

From 18 evaluated joints, eight (44.4%) had villous proliferation of thin and filamentous types (Fig. 1.2), considered normal according to McIlwraith & Fessler (1978) and Lewis et al. (1987). In one animal, these villi were hyperemic, and, in nine, the synovial membrane was smooth, without villi. In all the cases, the villi were located at the medial compartment. McIlwraith & Fessler (1978) reported that, in normal articulations, the thin, filamentous, and polyp-shaped villi are commonly observed in equines. Similar findings were reported in dogs (Lewis et al., 1987). Joint with normal villi, but with evident hyperemia suggests inflammatory process, and once the villous type is considered normal, it is possible to infer

Discrete hyperemia of the synovial membrane was observed in 17 (94.4%) dogs on Day 0 (Fig. 1.3), during the procedure that lasted 15 minutes on average. Due to the absence of dense fibrous tissue in the synovial membrane, increased local irrigation with congestion and swelling can develop during prolonged arthroscopic procedure (Lewis et al., 1987; Kurosaka et al., 1991), what may explain the findings of this work, not being, necessarily, synovial inflammation. In 14 dogs, the presence of blood vessels (Fig. 1.4) was observed along the CrCL. Despite these alterations in vascularization, the CrCL was intact and shining on Day 0, as well as the caudal cruciate ligament, the meniscofemoral ligament (Fig.1.5), and the long digital extensor tendon (Fig. 1.6). The origin of the popliteus muscle

tendon was visualized in two animals (Fig. 1.7), and presented no alteration.

in one animal (5.6%), irregularities at the trochlear ridge were detected.

as observed in this study.

that the process is at an initial phase.

articular cartilage.

Fig. 1. Arthroscopic images of the stifle joint of dogs submitted to experimental section of the cranial cruciate ligament (Days 0 and 21) guided by arthroscopy. 1) Articular surfaces of the patella (PA) and trochlea (TC) of the femur without alterations; 2) Synovial membrane of the lateral compartment with filamentous villi ( arrow), lateral condyle of the femur ( arrow); 3) Synovial membrane (MS) with discrete hyperemia at the medial compartment; 4) Blood vessel along of the cranial cruciate ligament (LCCr), caudal cruciate ligament(LCCd); 5) Meniscofemoral ligament (arrow); 6) Lateral compartment showing the lateral femoral condyle (LFC), long digital extensor tendon (arrow) and lateral meniscus (LM) 7) Origin of the popliteus muscle tendon(PT); 8) Intercondylar fossa with thin villi, stump of the cranial cruciate ligament showing nodular formation on the end of the torn ligament (arrow); 9) Villi in the shape of filamentous at the lateral compartiment; 10) Villi in the shape of polyp (arrows) at the medial compartment, medial femoral condyle (MFC); 11) Villus in the shape of fringe(arrows), lateral femoral condyle (LFC); 12) Villus in the shape of fan (arrow), lateral femoral condyle (CLF); 13) Lateral compartment showing villi in the shape of staff (arrow).

On Day 21 after CrCL section, at the arthroscopic examination, alterations suggesting articular degenerative process came to evidence. The arthroscopy, as mentioned by Adamiak (2002), is effective in precisely diagnosing the CrCL rupture and evaluating the evolution of the degenerative lesions of the joint, fact that was verified in this study.

Arthroscopic Follow-Up After Rupture of the Cranial Cruciateligament 161

insertion of the patellar ligament and quadriceps tendon (Fig. 2.10 and 2.11), at the suprapatellar pouch towards the trochlea (Fig. 2.12), at the femoral condyles (2.13), and at the intercondylar fossa towards the condyles. This was statistically significant for the region of the femoral condyles. Such a finding corresponds not to the cartilage vascularization

**1 2 3 4 5**

**6 7 8 9 10**

**11 12** *13 14*

Fig. 2. Arthroscopic images of the stifle joint of dogs submitted to experimental section of the cranial cruciate ligament (Days 0 and 21) guided by arthroscopy. 1) Lateral compartment showing villi short, membranous and in the shape of staff (arrows); 2) Visualization of the long digital extensor tendon, vascularization (arrow), 3) Thin villi at the long digital extensor tendon (arrow), lateral femoral condyle (LFC), 4) Fibrillation at the lateral femoral condyle (LFC); 5) Fibrillation ( arrows) and fibrin at the surface of the patella (PA), proximal trochlear groove (TC); 6) Fibrin attached to the lateral femoral condyle (LFC) (arrows); 7) Fibrin at the medial femoral condyle (arrow) and patella; 8) Supratellar pouch with

vascularization and fibrin (arrow); 9) Lateral femoral condyle (LFC) with mild osteophytes (irregularities: arrow); 10) Vascularization at the insertion of the patellar ligament (arrow); 11) patellar tendon (arrow); 12) suprapatellar pouch 13); and at the medial trochlear ridge of the femoral condyle (arrow) 14) Prolapse of the caudal horn of the medial meniscus

Statistically, the results regarding the lesion in the menisci were not significant; nevertheless, prolapse of the caudal horn of medial meniscus (Fig. 2.14) was visualized in four animals (22.2%). In one of them, on Day 0, there were alterations compatible with synovitis, like hyperemia and increased synovial membrane villi. Three of them presented, on Day 21, meniscus lesion and periarticular irregularities. The medial meniscus is more susceptive to lesions due to its capsule fixation (Moore & Read, 1996). It is reported that meniscus lesions occur about the seventh week of articular instability by CrCL rupture (Johnson & Johnson, 1993). In this work, the precocious occurrence of this kind of lesion may

(MM).

itself, but to the synovial membrane vascularization that invades the cartilage.

At the arthroscopic examination, in all animals, nodular formation on the end of the torn ligament were observed in the remaining stump of the CrCL on Day 21 (Fig. 1.8). In all animals, villous proliferation and synovial membrane hyperemia were observed, suggesting synovitis. As already reported by Van Ryssen & Van Bree (1998), Sams (2000), Adamiak (2002), and Beale & Hulse ( 2010), arthroscopy is an ideal diagnostic mean for evaluating macroscopically the synovial membrane, since the villi are kept in suspension in the irrigation liquid and, thus, projected into the cavity. Different types of villi, as well as different grades of hyperemia and vascularization were identified in detail (Table 1). Increase in the quantity of villi and new shapes were verified. Also, villous proliferations in all articular compartments were evidenced, suggesting DJD, as described in literature (Lewis et al., 1987; Kurosaka et al., 1991; Beale et al, 2003; Borges, 2006). Filamentous and thin (Fig 1.9), short, interlaced, as well as in the shape of polyp (Fig. 1.10), fringe (Fig. 1.11), fan (Fig. 1.12), staff (Fig. 1.13), short, membranous and staff(Fig. 2.1) and cauliflower villi were identified. In 21.8% of the joints, there were only short, thin, and filamentous villi, characterizing discrete synovitis. These three types of villi were found in bigger quantity and in all joints. In 55.5% of the animals, associated to the already mentioned villi, there were also those in the shape of bush, fan, polyp, and interlaced, characterizing moderate synovitis. In 22.7%, villi in the shape of fringe and cauliflower were also found, characterizing severe synovitis. Such characteristics of the synovial membrane are associated to DJD. In humans, the arthroscopic examination of the synovial membrane is employed for characterizing and diagnosing different types of pathological articular processes, as, for instance, traumatic, suppurative, tubercular, and rheumatoid arthritis (Kurosaka et al., 1991). At the insertion of the long digital extensor tendon, neovascularization was noticed in three animals (Fig. 2.2), while, in two, thin and apparently normal-colored villi (Fig. 2.3) were seen. Fibrillation in the articular cartilage and absence of erosion in the articular surfaces were verified in all evaluated animals. Fibrillation, according to Johnston (1997), is the initial microscopic finding of DJD. It may be observed as soon as one week after CrCL rupture (Johnson and Johnson, 1993), while erosive lesions are late findings, which occur with, at least, 60 days of joint instability. Statistically, fibrillation was predominant (Table 3) at the medial and lateral condyles (Fig. 2.4). Areas of fibrillation at the articular surface of the patella, the trochlear ridges of the femur, and the intercondylar fossa were also observed (Fig. 2.5). Fibrillation of the articular surface was arthroscopically evidenced as filaments from the cartilage into the articular space. In arthroscopy, the visualization of fibrillation is possible due to the amplified image and the liquid environment. By arthrotomy, it is only possible to detect areas that are apparently thickened, rugose, and opaque, corresponding to fibrillation (Sams, 2000; Adamiak, 2002). There was also fibrin at the lateral (66.%) and medial (34%) compartments (Fig. 2.6 and 2.7, respectively), and at the suprapatellar pouch (27.7%; Fig. 2.8), as well as osteophytes at the trochlear ridges, distal extremity of the patella, and suprapatellar pouch. Osteophytosis was statistically significant (Table 4) at the lateral trochlear ridge (Fig. 2.9). Muzzi (2003) detected radiographically the formation of osteophytes with, at least, 30 days of CrCL rupture. The arthroscopic findings concerning the presence of osteophytes, 21 days after articular destabilization were similar to those reported by Lewis et al. (1987). The presence of periarticular osteophytes is one of the signs of DJD (Elkins et al., 1991; Moore & Read, 1996). Thirteen animals presented vascularization of the articular cartilage, evidenced at the

At the arthroscopic examination, in all animals, nodular formation on the end of the torn ligament were observed in the remaining stump of the CrCL on Day 21 (Fig. 1.8). In all animals, villous proliferation and synovial membrane hyperemia were observed, suggesting synovitis. As already reported by Van Ryssen & Van Bree (1998), Sams (2000), Adamiak (2002), and Beale & Hulse ( 2010), arthroscopy is an ideal diagnostic mean for evaluating macroscopically the synovial membrane, since the villi are kept in suspension in the irrigation liquid and, thus, projected into the cavity. Different types of villi, as well as different grades of hyperemia and vascularization were identified in detail (Table 1). Increase in the quantity of villi and new shapes were verified. Also, villous proliferations in all articular compartments were evidenced, suggesting DJD, as described in literature (Lewis et al., 1987; Kurosaka et al., 1991; Beale et al, 2003; Borges, 2006). Filamentous and thin (Fig 1.9), short, interlaced, as well as in the shape of polyp (Fig. 1.10), fringe (Fig. 1.11), fan (Fig. 1.12), staff (Fig. 1.13), short, membranous and staff(Fig. 2.1) and cauliflower villi were identified. In 21.8% of the joints, there were only short, thin, and filamentous villi, characterizing discrete synovitis. These three types of villi were found in bigger quantity and in all joints. In 55.5% of the animals, associated to the already mentioned villi, there were also those in the shape of bush, fan, polyp, and interlaced, characterizing moderate synovitis. In 22.7%, villi in the shape of fringe and cauliflower were also found, characterizing severe synovitis. Such characteristics of the synovial membrane are associated to DJD. In humans, the arthroscopic examination of the synovial membrane is employed for characterizing and diagnosing different types of pathological articular processes, as, for instance, traumatic, suppurative, tubercular, and rheumatoid arthritis (Kurosaka et al., 1991). At the insertion of the long digital extensor tendon, neovascularization was noticed in three animals (Fig. 2.2), while, in two, thin and apparently normal-colored villi (Fig. 2.3) were seen. Fibrillation in the articular cartilage and absence of erosion in the articular surfaces were verified in all evaluated animals. Fibrillation, according to Johnston (1997), is the initial microscopic finding of DJD. It may be observed as soon as one week after CrCL rupture (Johnson and Johnson, 1993), while erosive lesions are late findings, which occur with, at least, 60 days of joint instability. Statistically, fibrillation was predominant (Table 3) at the medial and lateral condyles (Fig. 2.4). Areas of fibrillation at the articular surface of the patella, the trochlear ridges of the femur, and the intercondylar fossa were also observed (Fig. 2.5). Fibrillation of the articular surface was arthroscopically evidenced as filaments from the cartilage into the articular space. In arthroscopy, the visualization of fibrillation is possible due to the amplified image and the liquid environment. By arthrotomy, it is only possible to detect areas that are apparently thickened, rugose, and opaque, corresponding to fibrillation (Sams, 2000; Adamiak, 2002). There was also fibrin at the lateral (66.%) and medial (34%) compartments (Fig. 2.6 and 2.7, respectively), and at the suprapatellar pouch (27.7%; Fig. 2.8), as well as osteophytes at the trochlear ridges, distal extremity of the patella, and suprapatellar pouch. Osteophytosis was statistically significant (Table 4) at the lateral trochlear ridge (Fig. 2.9). Muzzi (2003) detected radiographically the formation of osteophytes with, at least, 30 days of CrCL rupture. The arthroscopic findings concerning the presence of osteophytes, 21 days after articular destabilization were similar to those reported by Lewis et al. (1987). The presence of periarticular osteophytes is one of the signs of DJD (Elkins et al., 1991; Moore & Read, 1996). Thirteen animals presented vascularization of the articular cartilage, evidenced at the insertion of the patellar ligament and quadriceps tendon (Fig. 2.10 and 2.11), at the suprapatellar pouch towards the trochlea (Fig. 2.12), at the femoral condyles (2.13), and at the intercondylar fossa towards the condyles. This was statistically significant for the region of the femoral condyles. Such a finding corresponds not to the cartilage vascularization itself, but to the synovial membrane vascularization that invades the cartilage.

Fig. 2. Arthroscopic images of the stifle joint of dogs submitted to experimental section of the cranial cruciate ligament (Days 0 and 21) guided by arthroscopy. 1) Lateral compartment showing villi short, membranous and in the shape of staff (arrows); 2) Visualization of the long digital extensor tendon, vascularization (arrow), 3) Thin villi at the long digital extensor tendon (arrow), lateral femoral condyle (LFC), 4) Fibrillation at the lateral femoral condyle (LFC); 5) Fibrillation ( arrows) and fibrin at the surface of the patella (PA), proximal trochlear groove (TC); 6) Fibrin attached to the lateral femoral condyle (LFC) (arrows); 7) Fibrin at the medial femoral condyle (arrow) and patella; 8) Supratellar pouch with vascularization and fibrin (arrow); 9) Lateral femoral condyle (LFC) with mild osteophytes (irregularities: arrow); 10) Vascularization at the insertion of the patellar ligament (arrow); 11) patellar tendon (arrow); 12) suprapatellar pouch 13); and at the medial trochlear ridge of the femoral condyle (arrow) 14) Prolapse of the caudal horn of the medial meniscus (MM).

Statistically, the results regarding the lesion in the menisci were not significant; nevertheless, prolapse of the caudal horn of medial meniscus (Fig. 2.14) was visualized in four animals (22.2%). In one of them, on Day 0, there were alterations compatible with synovitis, like hyperemia and increased synovial membrane villi. Three of them presented, on Day 21, meniscus lesion and periarticular irregularities. The medial meniscus is more susceptive to lesions due to its capsule fixation (Moore & Read, 1996). It is reported that meniscus lesions occur about the seventh week of articular instability by CrCL rupture (Johnson & Johnson, 1993). In this work, the precocious occurrence of this kind of lesion may

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Johnston, A.S. (1997). Ostearthritis: joint anatomy, physiology and pathobiology. *Vet. Clin. North. Am.:Small Anim. Pract*., vol.27, nº4, pp. 699-719, ISSN 0195-5616 Kurosaka, M., Ohno, O.& Hirorat, A.K.( 1991). Arthroscopic evaluation of synovitis in the

Lazar, T. P., Berry, C. R., de Haan, J. J., Peck,J. N. Correoa, M.(2005). Long-term radio-graphic

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Lipowitz, A.J.; Wong, P.L.; Stevens, J.B. (1985). Synovial membrane changes after experimental

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5, PMID 21792476, DOI: 10.3415/VCOT-10-12-0161, ISSN 0932-0814

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ligaments, In: *Advances in the canine cranial cruciate ligament*, P. Muir,(Ed.), 5-12, Wiley-

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Anthroscopic and clinical comparison between sodium hyaluronate (500-730 kDa) and methilprednisolone acetate. *J.Orthopaed. Traumatol.,* vol. 3, nº2, pp.89-96, ISSN

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radiographic, arthroscopic and histological measures of articular pathology in the canine elbow joint. *The Vet. Journal*, vol.186, nº 1, pp. 96-103, ISSN 1090-0233 Hulse, D., Beale, B., Kerwin, S. ( 2010). Second look arthroscopic findings after tibial plateauLeveling osteotomy. *Vet. Surg*. vol. 39, nº 3, pp. 350-354, ISSN 0161-3499 Innes, J. F., Costello ,M., Barr, F. J., Rudorf, H., Barry, A. R. S.(2004). *Vet. Radiol. Ultrasound*,vol.

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diagnosis, and postoperative rehabilitation. *Vet. Clin. North Am.: Small Anim.* 

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methods used in the evaluation of early degenerative joint disease in the dog. *J. Am.* 

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be attributed to the eventual excited behavior of the patients. Concerning the DJD, the body mass of the animals, which ranged from 18 to 25 kg, must also be considered for this study. According to Bennett et al. (1988), the CrCL rupture in dogs with body mass under 15 kg usually causes degenerative alterations that are less severe than in heavier dogs.

### **4. Conclusions**

As a valuable instrument for macroscopic evaluation of articular tissues, arthroscopy is a safe method for diagnosing and following-up the alterations in the stifle joint of dogs. The technique allows tracking the evolution of the degenerative lesions, as well as classifying the synovitis according to the villi shape and synovial membrane hyperemia.

#### **5. References**


be attributed to the eventual excited behavior of the patients. Concerning the DJD, the body mass of the animals, which ranged from 18 to 25 kg, must also be considered for this study. According to Bennett et al. (1988), the CrCL rupture in dogs with body mass under 15 kg

As a valuable instrument for macroscopic evaluation of articular tissues, arthroscopy is a safe method for diagnosing and following-up the alterations in the stifle joint of dogs. The technique allows tracking the evolution of the degenerative lesions, as well as classifying the

Adamiak, Z. (2002). Arthroscopy in dogs with cranial cruciate ligament injuries.*Indian Vet. J*.

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Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil Case, J. B., Hulse, D. Kerwin, S. C., Peycke, L. E. (2008). Meniscal injury following

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arthroscopical evaluation and synovial membrane histology of the knee of dogs treated with chondroitin sulphate- sodium hialuronate association after experimental degenerative joint disease. *Brasilian J. Vet. Res. Anim. Sci*., vol.55, nº4,

anatomical and funcional analysis. *Am. J. Vet. Res*., vol.38, nº 11, pp.1807-1814, ISSN

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*Internal Medicine*. 4.ed., S.J. Ettinger & E.C. Feldman (Eds.), pp. 2032-2077, Saunders,

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initialcranial cruciate ligament stabilization surgery in 26 dogs ( 29 stifles). *Vet.* 

usually causes degenerative alterations that are less severe than in heavier dogs.

synovitis according to the villi shape and synovial membrane hyperemia.

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**4. Conclusions** 

**5. References** 


**10**

 *Portugal* 

**Congenital Aplasia of the** 

Bruno Colaço, Maria dos Anjos Pires

*CECAV, Univ. of Trás-os-Montes and Alto Douro,* 

and Rita Payan-Carreira

 **Uterine-Vaginal Segment in Dogs** 

Müllerian duct abnormalities consist of a set of structural malformations that include diverse situations of agenesis or aplasia, which may evolve according to three distinct patterns: a failure of the paramesonephric ducts (Müllerian ducts) to develop in the whole or in part (uterus unicornis and segmental aplasia of uterine horn, respectively), the failure of caudal part of the paramesonephric ducts to the fuse and to form one single lumen (leading to situations such as uterus didelphus and the cranial vagina septation) and the failure of the fused caudal paramesonephric ducts to fuse with the urogenital sinus with consequent absence of anatomic continuity between the cranial vagina and the vestibule

Prevalence of these anomalies ranges from 0.02 to 0.05% in the canine population (Roberts, 1971; McIntyre et al., 2010). The relative frequency of the different abnormalities varies upon the region and the year of publication (Roberts, 1971; Ortega & Pacheco, 2007; McIntyre et al., 2010), and the clinical descriptions are insufficient to establish epidemiology of the

In dogs, the uterine and vaginal segments can show developmental abnormalities ranging in severity from hypoplasia to complete agenesis (Romagnoli & Schlafer, 2006; McIntyre et al., 2010), and the severity of the defect influences the reproductive outcome and the existence of clinical side effects. The mildest form is the vagino-vestibular stricture, where secretions are collected in the cranial vagina and uterus, while in the more extreme form the uterus

Although not uncommonly found during elective ovariohysterectomy, often they are detected co-existing with increased dimensions of the uterus and signs of mucometra or pyometra. There is a complete obstruction to fluid drainage from the uterus (as in vaginal or cervical atresia) and the owner may complaints that the female does not evidence the expected estrus vulvar discharge. With time, in obstructive diseases of the uterus or vagina, it is also possible to observe dysuria, cystitis, pyometra and renal failure (Kyles et al, 1996). However, in unicornuate uterus this is seldom the case and often the main complaint is infertility or sterility (Romagnoli & Schlafer, 2006; McIntyre et al., 2010). The animal may

(originating an imperforate hymen or the vaginal stenosis).

may be partially or in the whole reduced to a string, fibrous structure.

**1. Introduction** 

defects.

