Sofia city, Bulgaria
The radial nerve palsy is a pathology that is rarely seen in dogs, in comparison to cats, where it is more commonly seen, especially in young stray cats. The most commonly observed clinical picture in such patients includes paralysis of the antebrachial portion of the limb, the carpus, the manus and fingers. According to our personal observations, in about 25% of these patients the elbow’s neuro-muscular apparatus is also involved, in a different degree.
The patients demonstrate an external rotation of the antebrachial area in relation to the portion of the limb above the elbow.
The carpus and manus possess an additional and permanent external rotation in relation to the antebrachium, which causes the patients to use the rostral portion of the their carpus for stepping and weight bearing, which in turn inducts the formation of a chronical traumatic inflammatory proliferative granuloma in this area. For about a 25-45 days period, an impossible to overcome carpal hyperfelexion develops, to the point where the joint can no longer be returned to its physiological position, due to the shortening of the flexor muscle-tendon apparatus (see video 1 with cat Sonia 39 days after the trauma at https://youtu.be/SZoXfp8tMJ0 ).
A few therapeutic approaches are being advised for this pathologic condition worldwide: total limb amputation; stem cell therapy (with still controversial results); standard pancarpal arthrodesis (note that very often it is very difficult to execute procedure in the state of this disease and is almost always accompanied by a nonsatisfactory limb function end result).
None of the upper mentioned approaches for treatment of radial nerve palsy in cats, while trying to avoid limb amputation, was producing satisfying results in the patients with this problem, operated by our team. This is the reason we decided to test and implement a new “Dobro hrumvane modified pancarpal arthrodesis” procedure for the operative treatment of feline radial nerve palsy.
- Report patients base
Up to this moment, this modified by our team procedure has been done in 111 patients. In the first 11 patients we tried different but very similar to each other versions of the modification, and after patient 12 up to patient 111 (meaning exactly 100 patients) we were performing always one same version of the technique.
In 87 of these patients a follow-up postoperative monitoring for over one year has been performed (in 9 of them an approximately 5 year follow up was achieved, in 33 patients the follow up period was approximately 4 years etc.), in 11 patients the follow up period was between 4 months and one year and in 2 patients the follow up period was less than 4 months. In four of the operated patients, pre- or postoperative clinically relevant paralysis of the elbow region was also observed. As was mentioned earlier, 25% of feline radial nerve palsy patients demonstrate this (according to our observations in 23% of the patients it is already observed in the preoperative period and in other 2%, it develops a few weeks after the surgical intervention, with the reasons for that still being unclear). It should be noted that the majority of owners of patients with elbow area involvement preferred amputation over the experimental procedure.
- Surgical technique
The standard pancarpal arthrodesis general guidelines are being followed, but with the following modifications:
- Straight 11̊ inclination non locking hybrid pancarpal arthrodesis plate has been used (produced by Medimetal or Mikromed, delivered by VetWest). The plate contouring should be modified before the surgery and the inclination should become 21-22̊. Twisting of the distal portion of the plate internally in relation to the proximal portion of the plate is not recommended! For the fixation to the metacarpus 1.5 mm non locking screws were used (produced by Mikromed, delivered by VetWest) and for the fixation to the radius 2.0 mm non locking screws were used (produced by Mikromed, delivered by VetWest);
- The proximal (os carpi radiale et ulnare) and distal carpal bones are being completely removed, this being done with extreme caution not the traumatize the adjacent magistral structures (especially blood vessels), which are located on the palmar surface;
- The proximal ends of the metacarpal bones are being separated from one another;
- The fixation of the plate to the dorsal surface of the third metacarpal bone is achieved the same way as in the standard technique, using 1.5 mm thick and 6 mm long screws, but the fixation to the radius is not applied on its dorsal, but on its medial/mediocaudal edge/surface, using 2.0 mm screws. The screw hole on the plate which is intended for os carpi radiale (note that this bone is actually removed in the modified technique) is used for an additional 2.0 mm screw, placed in the distal radius. In other words, the whole metacarpal portion of the limb is being internally rotated around 85-95° (for the purpose of that an almost full blunt and careful separation of all soft tissues, including the magistral vessels and nerves in the distance between the carpus and the middle portion of the metacarpal bones, should be performed). After plating of the third metacarpal plate with four 1.5 mm non locking screws in neutral position the third metacarpal bone is being compressed to the radial distal This compression is easily achieved with the first screw, placed in the radius (not dorsal but medial/mediocaudal radial edge/surface – see below Xray picture Standard) thanks to the DC wholes of the plate types mentioned upper above. This screw is being inserted in the second 2.0 mm screw whole in distal to proximal direction, meaning the third plate hole in relation to the whole plate in proximal to distal direction. After that, 4 neutrally (not in compression mode) placed screws are applied to radial bone in the following order: the most distal hole, the most proximal hole, the second hole in proximal to distal direction, the third hole in proximal to distal direction. It is recommended that at least two of the screws in the distal radius engage the distal ulna too, so the distal portions of the two bones could eventually be pulled together – the screws could be numbers one and two or four and five from proximal to distal, this possibility could be estimated only intraoperativelly;
- With this technique it is easy and recommendable to use a significant amount of autograft material – recommendable due to the large gap that is being created. This autograft is readily available, considering the amount of bone that is being removed in the previous stages of the surgical technique;
- The final stage of the surgery includes almost full blunt separation of the skin from the underlying soft tissues in the designated area, along with skin plastic traction modification, which is intended to place the fifth finger in a more medio-cranial position. The skin sutures and respectively the skin incision should be placed in a position that is not exactly above the plate (eventually they plate and incision could be placed in a cross manner, but should not be on top of each other for their whole lenght). It is not necessary to perform tenodesis of the digital extensors or excision of some skin on the dorsal carpal area in orther to pull the fingers in extension. It shoud be noted that the upper mentioned skin traction used to “pull” the fifth finger in a more dorsal and medial direction (meaning that the fifth finger is placed adjasent to the dorsolateral, not solely lateral, surface of the fourth finger, under subtle tension that will not allow overlapping of the fifth finger) is extremely important because in some of the first patients, which underwent the still not perfected procedure, weeks to months after the surgery pressure necrosis developped in the fifth finger, which required further revison plastic surgeries.
- In patients that have a very wild temper and where it is not possible to achieve two week long cage rest, postoperative splint could be placed. If this is done, additional amount of cotton could be used to help achieve the upper mentioned mediocranial position of the fifth metacarpus and finger;
- NEO K-9 clinical formula is prescribed for a month and a two week long cage rest is done in more calm patients.
- C) Results – the last 100 cats (No 12 … No 111 made with identical technique) :
C1) 96 patients that did not have (according to our clinical opinion) involvement of the elbow region pre- or postoperatively:
– 95 patients with good limb geometry in stance and during walking, active involvement of the limb during walks and playing, owners completely content with the results 4 months up to 5 years after the surgery. 89 of these 95 patients had no postoperative complicatioons; 2 patients developed moderate postoperative infection that was easily treated; 2 patients demonstrated delayed healing of the surgical incision in the area above the plate (it took more than 5 weeks in both patients); 2 patients had delayed bone union, that took around 5 months to be completed;
– 1 patient demonstrated unsatisfactory to this point level of weigt bearing and limb usage during walk and play. It is understandable that the owner of this patient is not completely content with the results, but is unfortunately refusing implant removal and further diagnostic procedures;
– No cases with implant loosening, intra- or postoperative fracture, postoperative necrosis etc.;
C2) 4 patients with clinically relevant pre- or postoperative involvement and paralysis of the motor unit of the elbow joint:
– 1 patient without preoperative elbow problem, developed such around a month after the surgical intervetion and the problem was accompanied by the development of an additional low grade external rotation of the antebrachium in relation to the limb portion above the elbow. The main problem was presented by progressive loss of support of the ebow joint in extension during stance, which lead to the inability of the limb to support the body during weight bearing. The problem was resolved after a two week long active rehabilitation and machine physiotherapy and application of a light splint, which is suporrting (but not blocking) the elbow.
– 1 patient (cat named Trun) with preoperative paralysis of the elbow joint, but accompanied by almost complete ankylosis of the elbow joint (only 15% of the normal range of motion was preserved, especially the extension was blocked) – see below the post-op pictures of cat Trun
Although there was a serious accompanying problem, months after the surgery the owners are completely satisfied with the result. The patient is using the limb with no limitations during play, almost no limitations while running and with some limitations while walking – that last limitation is probably due to the constant flexed position of the elbow, which is exceeding the normal flexion angle of an elbow joint during walk, thus the animal is placing the shoulder of the affected limb under the level of the shoulder of the unaffected limb, during weight bearing (see video with cat Trun approx 3 months post-op at https://youtu.be/N9scMppZeyo ). The owners do not report signs of pain. Even though it is not right to make conclusions only on the basis of a single patient, this case gives us hope that patients with radial nerve palsy in combination with complete or partial elbow joint ankylosis have the chance to avoid amputation of the limb.
– 1 patient with partial preoperative paralysis of the elbow joint which became more severe (around 50%) month after the surgery: the bones in the arthrodesis region achieved complete healing, but the elbow joint loses support during weight bearing, thus the animal is placing the shoulder of the affected limb under the level of the shoulder of the unaffected limb, during weight bearing. Due to this the ptient is weight bearing the limb not on its pads, but rather on the carpal palmar angle surface. Because of that a chronic nonhealing skin lesion developed in this area over the time, which is intermitently bleeding. Up to this point, the owners are content with the result and do not wish to start rehabilitation or agree to a revision surgery, but for our team this result is unsatisfactory and it requires additional surgical and/or physiotrepautical intervention;
– 1 patient (Doxy) wtihout preoperative involvement and paralysis of the elbow, which developed a progressive clinically relevant paralysis of the elbow a few weeks after surgery. This led not only to loss of support of the elbow joint during weight bearing, but also to constant progressing additional rotation of the antebrachium in relation to the humeral area.
This rotation made the patient bear weight on the lateral surface of the carpal angle, developing a skin lesion there. This postoperative elbow joint paralysis did not resolve after a rehabilitation course. In order to correct the problem an elbow arthrodesis was performed, but not in a standard way. A “double-modified” elbow arthrodesis was performed: the boomerang plate produced by Mikromed and supplied by VetWest was placed on the lateral surface instead of the medial. Also, the antebrachial region was rotated 18 degrees internally, in relation to the humerus. We recommend very torough preoperative preparation: the execution of the technique is quite challenging, because the compression must be maintained and in the same time the “locking” of the anconeal process in the humeral fossa must be overcome, along with the congruency of the other ulnar structures and their corresponding radial structures – see below post-op X-ray pictures of cat Doxy after the second surgery, the elbow modified arthrodesis:
It can be seen that the plating is on the lateral surface of the radius distally and on the laterocranial surface of the humerus proximally.
Only a few hours after the surgery, the patient demonstrated excellent, pain free limb usage, with very good limb geometry and lack of difference in the level of the two shoulder joints during weight bearing. In the following days the patient started using the limb for playing too. At this point, 3-4 months after surgery, the patient is demonstrating completely satifying results (see video with cat Doxy approx 4 months post-op at https://youtu.be/X_rFEgrZink ). There are no signs of malunion, infection or other types of complications. The muscle mass in the shoulder area of the operated limb is similar to that of the non operated limb. Even if it is based just on one patient, the result of this case gives us some hope for surgical resolution for patients with modified or standard carpal arthrodesis, which have an acompanying or later develop severe elbow pathology of nonakylotic kind, as we know that the combination of carpal and elbow arthrodesis is not recommended in the known sources. For this patient especially we have an additional recommendation:
1) The first recommendation that is applied to all 111 operated patients – considering that it is a patient with a paralysed limb it should live on a non- smooth surface (but also not on an abrasive one). On a slippery surface patients with Dobro hrumvane arthrodesis step with mild slipping which combined with the lack of sensitivity could cause in longer period skin lesion (see Video 2 with cat Zhivka approx 5 weeks post-op at https://youtu.be/hKKjmO9yWdI ).
2) Additional recommendation especially for Doxy: the patient has two joints that underwent arthodesis, which means that a stress point is being created between the two plates, which in turn creates a significant risk for further fractures. This risk is further amplified by the fact that the arthrodesis procedures are reducing the shock absorbing function of the joints. Considering all of the mentioned above, the patient should live in an enviornment that lacks the risk of creation of serious vertical vector forces (such as jumping to or from high places). It should be noted that Doxy did exactly that, many times after surgery and no problem occured, but it is still highly not recommended.
The 100 clinical cases, with patients that underwent a similar modified pancarpal Dobro hrumvane arthrodesis procedure for the treatment of feline radial nerve palsy demonstrate a constant and satisfying result with very good return to function of the limb, pain free, with no discomfort. No following complications, including long-term ones are being observed and there is a very high level of owner satisfaction. We recommend this surgical technique and we would be glad to recieve feedback afer the completion of the procedure, either in the algorithm recommended by us, or with any additional modifications.
Even when the rotation of the metacarpal area in comparison to the antebrachial area is not 85-95 degrees the patients use the leg and the owners are satisfied but the leg geometry is in our opinion not good looking. Cat number 11, the last before the standartized 100 patients chain, named Hari is such a case, the rotation was 78-80 %, the operation was made approximately 5 years ago. As you can see at the videos made 4 years post-op the patient uses the left operated leg even during acrobatic jumping (see below picture Hari)
and active playing (see video Hari 4 years after surgery at https://youtu.be/SfhzUtLr9ig ).
- E) Post scriptum
A few years ago we presented the technique and its results, based on a few dozens of cases, on a VOG\BAVOT event. Ever since, a few colleagues from the Balkan region have sent us feedback with very encouraging results, after using the technique. One of them was our inconsolable friend, colleague and inspirator, D-r V. Vasilev, whose memmory and collosal contribution to the development of the veterinary meidicine in Bulgaria we would like to honor in the end of this report.
Sofia The Orthopedic department of
March 2019 “Dobro hrumvane!” veterinary clinics
Blue Cross Veterinary Hospital
A 4 months old Labrador retriever was presented at the BlueCross Veterinary Hospital in Sofia, Bulgaria, with the owner complaining about painful episodes after touching the head of the animal.
Clinical examination: the dog is in a good clinical stage, no pathological heart or lung sounds.
The temperature was 39,5 C. No abdominal pain or other abnormalities.
The palpation of the skull was painful for the dog, there was slight dome shape of the cranium. The masseter muscles were atrophied. After palpation of the mandibula it was noted that the lower jaw of this dog looked enlarged. Pic 1
Considering the age, breed and the affection of the specific bones, the following list of differential diagnosis was made:
- Craniomandibular osteopathy
- Calvarial Hyperosthosis
We took a blood sample for CBC and biochemistry analysis.
On the CBC there was a slight decrease of the RBC – 5,36 (5.5- 8.5 x10/12/L) but this could be normal for younger animals.
On the biochemistry there was a slight decrease of the Total protein – 49 (51- 78) g/L and Albumin – 20(26- 41) g/L. Everything else was WNL.
The patient was sent for CT of the head to search for additional characteristics of the bones of the head and confirm my suspicion about the disease. We put an injection of NSAID for the pain until the test was done.
On the CT we discovered symmetrical bone proliferation of the rami of the mandubule and bone thickening of the calvarium of the animal. No underlying bone lysis was noted. Fortunately, till this moment affection of the temporomandibular joints was not discovered, but it is possible that this could happen during the next months.
There were not clear signs of neoplastic process or osteomyelitis. As a result, considering the information that we had, a diagnosis of craniomandibular osteopathy was made.
Craniomandibular osteopathy is a non neoplastic proliferative bone disease affecting immature dogs.
Usually the clinical signs start between 3 and 8 months of age. Common clinical presentation is pain episodes, fever, trouble chewing food, drooling and in more advanced cases – inability to open the mouth and eat. The etiology of this disease is unknown.
The first written description of CMO appeared in 1958.(9) It was described in five West Highland white terriers affected within a 2-year period. The most common breeds that are affected are West Highland white Terrier, Scottish Terrier, Cairn Terrier. The disease is described in other breeds – in Labradors, Boxers, Great Dane and a few more.
It is believed that this could be an inherited disease (autosomal recessive inheritance pattern) and as such it is advised for such animals to be neutered.
Commonly the affected dogs have bilaterally symmetrical enlarged mandibles and tympanic bulles, and affection of other bones of the calvarium. In severe cases those structures could fuse and this will lead to decreased range of motion of the temporomandibular joint. On examination, the temporal and masseter muscles may be atrophied.
In advanced cases, the diagnosis of craniomandibular osteopathy can be done with good positioned x-rays of the head of the animal. The advance imaging techniques, such as CT or MRI, improve the visualization and confirm the extension of the process.
On x- ray or CT increased irregular bone density is commonly observed – symmetrical periosteal proliferation, in most of the cases primary affection of the mandibules- 84%; tymplanic bulles – 51% and in some of the cases bones of the calvarium -13%.
The treatment plan is symptomatic with painkillers and anti-inflammatory drugs – commonly used drugs are NSAID and Steoids. Such drugs are needed during pain episodes and fever. Placement of an esophagostomy or gastrostomy feeding tube may be considered in patients that have difficulty eating and their nutritional requirements are not being met. Soft or liquefied food may be easier for some patients to eat. A high protein, high caloric food should be offered in order to meet nutritional needs.
Surgery of the bone proliferated tissues is not helpful in those cases.
The prognosis for these patients depends of the extent of progression of the disease. In those cases where a severe bone proliferation develops, the result is fusion of the temporomandibular joint and the prognosis is poor. Most of those dogs are euthanized because of the extent of the disease. It has been a common observation that when the affected dog is approximately 11 to 13 months of age, the disease may become self-limiting. The growth of abnormal bone slows, often regresses, and sometimes recedes completely. This period of self-limitation coincides with the time of completion of regular endochondral bone growth and ossification.
Our patient felt great after one injection of meloxicam. He is feeling active and has no signs of pain and temperature. Unfortunately, we cannot say whether his condition will progress to the extent to affect the temporomandibular joints and lead to inability to open its mouth.
The owner will return the dog to the breeder. It was advised to watch the dog for any additional signs and painkillers were prescribed.
Dr Svetoslav Penchev
United Veterinary Clinic
Case is about a 6 months , male cocker spaniel named Michael.Michael was brought in the clinic from another city in very bad candition.The owners report for a trauma in cervical region.Radiography and neurological examinations were made. Results revealed –Tetraplegie and atalnto-axial instability.It was made a CBCT on cervical region.The image show C2-Fracture .
It was maked a surgary to stabilize cervical spine. Ten days after surgery Michael starts moving the pelvic limbs first and tries to stand on them. Twenty one days after surgary Micheal start to moving and thoracic limb , but have ataxia and destroys proprioception on his four leg. Michael`s recovery begin first with the hind limbs and then with the thoracic limbs .In human literature, the symptom in which the thoracic limb is in a dysfunctional state with minimal to no deficit in the pelvic limbs has been referred to as CCS (Central Cord Syndrome ). The spinal cords that travel to the pelvic limbs are minimally affected because the lesion is centralized in the cervical region, which only affects the thoracic limbs. In general, CCS has a good prognosis for functional recovery and its common etiology is traumatic disease in human medicine. CCS treatments with nonsurgical management include cervical spine restriction with a neck collar, rehabilitation followed by physical therapy and occupational therapy. Surgical management is provided for patients who cannot be treated by conservative management alone.
Transplantation of ipsilateral canine ulna as a vascularized bone graft for treatment of distal radial osteosarcoma
Corresponding author :
Dr. Vladislav Zlatinov,
Central Veterinary Clinic
Chavdar Mutafov str, 25 B, Sofia, Bulgaria
This case report describes the successful use of a vascularized cortical autograft from the ipsilateral ulna in limb-sparing surgery for the treatment of distal radial osteosarcoma. A pancarpal arthrodesis with two orthogonal plates was performed to stabilize the site. No implant failure and local tumor recurrence were observed in the 6 months post operative period. Excellent limb function was achieved within 6 weeks after surgery; no external support (coaptation) were used during the post operative period. Excellent perceived quality recovery, was reported by the dog’s owners, compared to their preliminary outcome expectations.
Osteosarcoma (OSA) is the most common primary bone tumor in dogs, most commonly affecting the distal radius. Current treatment protocols-Fig.1 are based on a combination of surgery (limb amputation or limb sparing surgery) and adjuvant chemotherapy. Palliative therapies like- Stereotactic radiation or Percutaneous
Cementoplasty therapy are rarely applied with limited success 1,2.
Recently, numerous publications suggest that the Limb-sparing surgery is a viable alternative to limb amputation in selected cases, especially indicated if there is pre-existing orthopedic or neurological disease or if owners are resistant to limb amputation 3,4,5,6.
Limb- sparing consists of removing the segment of bone involving the primary tumor and using internal or external fixation to the remaining bones with or without segmental bone replacement, resulting in a salvaged functional limb 7. Limb- salvage procedures
have been described in the distal aspect of the radius, proximal humerus, distal tibia, and proximal femur in dogs with OSA, but the salvage surgery of the distal aspect of the radius has produced the most favorable results. This is mainly because pancarpal arthrodesis is well tolerated by dogs, not like fusion of other joints. Importantly – the prognosis for survival is the same with amputation or limb- sparing, unless an infection is present, in which case the average survival is prolonged.
Candidates for limb sparing
Good surgical candidates are dogs with OSA confined to the bone, with minimal extension into adjacent soft tissue and involving less than 50% of the bone length. The extent of bone involvement is most accurately determined by using computed tomography and is overestimated by radiography, nuclear scintigraphy, and magnetic resonance imaging 8. Pathologic fracture is a relative contraindication for limb-sparing because of tumor seeding into adjacent soft tissue, although the risk of local tumor recurrence can be reduced by use of preoperative chemotherapy or radiation therapy.
Limb sparing techniques
Historically, the most commonly performed limb sparing technique for the distal radial site involved the use of an allograft (donor from an individual of the same species) to replace the bone defect created by segmental bone excision 9- Fig.2. Although the limb function is good to excellent in about 80% of dogs with the allograft technique, the complication rate is substantial. The most common complications include infection, implant related problems, and local recurrence. Infection rate is reported to be up to 60%, implant failure in up to 50% as well. Even more, there are practicality issues for the regular application of the allograft technique- time consuming and costly maintenance of a bone bank. Recently, there is a new alternative for graft purchasing from a commercial source on a case by case basis.
It’s not surprising that alternative limb-sparing methods are being investigated. Reported grafting techniques include pasteurized/ irradiated autografts, endoprosthesis, vascularized ulnar transposition graft (roll-over technqique), free microvascular ulnar autograft.
Nevertheless the technical evolution of the available techniques, all of them are still often associated with a high complication rate including infection, construct failure, and tumor recurrence. The longitudinal or transverse bone transport osteogenesis has the advantages to lower the aforementioned complications but still have limitation for routine implementation in the practice 10, 11.
The advantages and disadvantages of the recent innovative techniques are shortly summarized below.
The most prominent advantage of the endoprosthesis limb salvage (Fig.3) is the simplicity compared to the other grafting techniques; consequently it is time-saving. Decreasing the surgery time may suggest lower infection ration. Unfortunately this was not proved by the clinical experience with the currently commercially available endoprosthesis.
A recent study 4, comparing the results of Cortical Allograft and Endoprosthesis techniques, suggested surgical infection of 60 and 55% of the cases, respectively. The use of a large volume of implants and foreign material has been proposed as a cause. More over in the same study, long term implant failure occurred in 40% of the treated dogs.
A positive remark in the paper is the good (subjectively) limb function, reported in the stable phases or in non-complicated cases.
A more biologic friendly technique- ulnar roll-over – Fig.4 was resently reported with good results, despite limb shortening of up to 24 % 3,12,13. The distal ulna is osteotomized, rolled into the radial defect, and secured with a bone plate and screws. With this technique the preservation of the caudal interosseous artery and vein and a cuff of the deep digital flexor, abductor pollicis longus, and pronator quadratus muscles are important for maintaining viability of the transplanted ulna.
Theoretically, using a vascularized bone graft could reduce the gross incidence of complications compared to an allografts or endoprothesis. Vascularized bone is more resistant to infections, to the extent that vascularized cortical autografts have been used to treat osteomyelitis. Also the use of a viable graft may preserve biomechanical properties over allografts. Whereas the allograft may resorb and become weaker over time, the ulnar graft may maintain its physical properties or even hypertrophy and healing with the host bones.
However, the statistics reports are controversial, with no clear proof for substantially better outcomes. One study shows no statistically different infection (45%) and implant failure (55%) ratio. Probably the presence of a viable graft does not address all other factors predisposing to infection (poor soft tissue coverage, immunosuppression from neoplasia and chemotherapy, and use of orthopedic implants). The other complication problem- implant failure, sounds as a surgeon’s skills dependent issue. For example one of the major complication in the mentioned study has been fracture of the remaining radius in cases of great length resection (>57%), which could be just consequence of suboptimal plate length or screws number and distribution.
Importantly, the roll-over technique demands sufficient length of the distal ulna to be preserved, but local recurrence was not increased compared to other limb- sparing techniques.
Microvascular anastomosed bone transfer was used in the presented case. This is a routine procedure in the limb sparing surgeries in human patient, but rarely applied technique in veterinary medicine, nevertheless, the vascular supply of the distal ulna has been , studied, described and successfully used experimentally and clinically 14,15.
In this technique, a more substantial middiaphysis segment of the ipsilateral ulna, with its source artery and vein (the common interosseous) is harvested and transpositioned, with a blood supply restored by vascular anastomosis to a neighboring artery and vein, once the graft is in its new position. The surgical technique is described further in the text. The concept is the same as the ulnar roll-over but, with the advantages of stronger cortical ulnar graft used, more mobile graft and a chance for full distal ulnar resection. The disadvantages of this procedure are the need for a specially trained and equipped microvascular team and the prolonged surgical time.
Longitudinal bone transport osteogenesis
This is a specific application of distraction osteogenesis, which has been used successfully in dogs for replacement of large segmental defects of the distal aspect of the radius and tibia after tumor resection. This is a process whereby healthy, detached bone segment is sequentially moved across an adjacent segmental osseous defect forming new regenerate bone in the distraction gap -Fig.5.The regenerate bone is highly vascular and resistant to infection.
The results following the procedure have been very encouraging, with good orthopedic function and no reported infections. Disadvantages of the bone transport osteogenesis procedure is the significant amount of time required to fill the defect after tumor removal (up to 7 months). This often leads to owner compliance issues (distracting the apparatus two to four times per day), also pin-tract drainage and loosening, difficulty in docking the intercalary bone onto the radial carpal bone.
A recent modification –Transverse Ulnar Bone Transport Osteogenesis, has been reported 16- Fig.6. The technique substantially decrease distraction times. In one case report, distraction of the ulnar transport segment across the 84 mm longitudinal segmental radial defect, was completed in 23 days.
A 9-year-old female Rottweiler dog (43 kg) was referred to our practice with a 3- weeks history of left forelimb lameness with an gradual onset and an unknown origin. The dog was been previously prescribed NSAIDs with temporary effect. During our examination we found weight-bearing lameness II/V. Physical and orthopedic examination revealed distal radial swelling on the left forelimb, with pain on extension of the carpal joint.
Orthogonal radiographs were achieved, revealing vast osteolytic (relatively smooth margins) area in the distal radius, with no apparent lesions in the distal ulna- Fig.7
Based on the history, signalment, lesion location, and radiographic findings, a primary bone tumor was suspected.
No abnormalities were detected on preoperative 3-view thoracic radiographs, abdominal ultrasound, echocardiography, and blood tests- Fig.8. The Alkaline Phosphatase (AP) value was 195 U/L- in the upper limit but still within the reference range for the breed.
Treatment options were discussed with the owners:
-conservative palliative treatment
-amputation and chemotherapy
-limb-sparing surgery in conjunction with chemotherapy;
The owners chose the last course of treatment but insisted on preoperative histologic confirmation of the suspected diagnosis.
After short anesthesia and minimal invasive approach, tissue biopsy sample was retrieved and send for analysis. Ten day later the the suspicious of osteosarcoma neoplasia was confirmed. The histologist comments were: moderately aggressive OSA with low mitotic figures. Meanwhile the dog showed acute lameness deterioration, related to a pathological fracture of the cranio-distal cortex of the radius, following the biopsy procedure- Fig.9.
A limb sparing procedure (roll-over vs. free vascularized) grafting was planned.
Twenty minutes before the skin incision high segmental epidural analgesia wad accomplished at the level of T11, infusing 2 ml of 0,25 % Levobupivacian solution and positioning the patient in left lateral recumbency for 10 minutes- Fig. 10.
For the surgical intervention, the dog was positioned in sternal recumbency- Fig 11. , facilitating a dorsal approach to the radius and carpus. Careful tissue examination was done during the sharp dissection of the distal soft tissues. Caudally, the tumor was closely attached to the distal ulna. Thus, the tumor was not dissected caudally to avoid contamination. A decision for a more extending distal ulnar resection was made. This prevented the option for roll-over technique more advanced free vascularized transfer was prepared.
The extensor carpi radialis muscle was transected proximal and distal to the tumor; the common and lateral digital extensor tendons were spared. An oscillating saw was used in both radial and ulnar osteotomies. The level of the transverse osteotomy of the radius, 2 cm proximal to the tumor, was determined on radiographs and confirmed appropriately intraoperatively. The ulna was osteotomized at lower level, just over the overlapping zone with the radius. The radius was disarticulated at the antebrachiocarpal joint and the tumor removed en bloc with the distal ulna. The length of the resected radial segment was 10 cm, including the 2-cm free margins (this represented 45% of the total radial length). The whole radio-ulnar segment was stored in 10 % formalin solution for later histologic analysis-Fig.12 and 13
After tumor removal the limb sparing was continued with cartilage debridement from the carpal and metacarpal bones , accomplished by using a speed burr drill; several penetrating drill holes were created in dorsal surface of the radial carpal bone.
The resected radial bone segment was measured and a second ulnar osteotomy performed proximally using a separate blade to match the length of removed radial bone minus 1,5 cm. The proximal ulnar osteotomy was performed above the level of the radial osteotomy while identifying and carefully dissecting the caudal interosseous artery and vein.The last were a-traumatically clamped and transected as proximal as possible, preserving as much as possible of the vessel length.The muscle attachments of the abductor pollicis longus, ulnar head of the deep digital flexor, and pronator quadratus were kept intact onto the periosteum of the distal aspect of the ulna.
The ulnar graft was transposed into the radial defect and the proximal end of the common interosseal artery (<2 mm) was anastomosed to a distal branch of the median artery. The anastomosis was accomplished with the use of magnification (10x) with surgical microscope and fine jewelers forceps- Fig.14 and 15. General principles of end-to-end vascular anastomosis were followed- atraumatic handling, distance of 0,5- 1 mm from the vascular wound’s edge, the regular suture distance, etc. Five interrupted sutures (8-0 nylon) were used to seal the anastomosis. The total ischemic time of the bone graft was about 60 minutes.
The microanastomosis success was confirmed by identification of a active blood flow present in the graft’s tissues and the distal end of the interosseal artery (video 1 ). The corresponding vein was not anastomosed, but its end was left free in the surrounding soft tissues. The distal artery ending was ligated.
After the anastomosis, the procedure was finished by stabilization of the bone graft by long plate, engaging from the distal metacarpal bones to the proximal radius, on the cranio-dorsal surface. We used hybrid 4,5 mm plate (Mikromed, human series) allowing fixation with 4,5 mm screw proximally, 3,5 mm in the middle area (free graft) and divergent 2,7 mm screws in the III and IV metacarpal bones. A second orthogonal plate 3,5 mm reconstructive locking (Mikromed) was applied laterally, fixating the proximal radius to the fifth metacarpal bone- Fig.16 and 17. Copious cancellous bone graft (from proximal humerus) was retrieved and stacked at the level of all osteotomy gaps.
After copious wound lavage and before closing of the surgical wound, the implants were covered by Gentamycin impreganted bovine collagen sponges (Gentacoll- resorb). The goal of the last was infection prevention. A soaker catheter was also inserted along the full length of the surgical wound. Subcutaneous tissue and skin were closed routinely. After skin suturing, the leg was bandaged with modified Robert -Jones bandage for the next 12 hours. The soaker catheter was attached to elastomeric pump, delivering 1 % Lidocain solution – 5 ml/h, for the next 3 days.
Post operative care
Postoperative analgesia consisted of: local Lidocain flash block delivery by the elastomeric pump (36 h) , Butorphanol (0.3 mg/kg, every 6 h, i.v.) and meloxicam (0.1 mg/kg /24h ,s.c.).
Cryotherapy (frizzed towels compresses) was applied every 4 hours for the next 48 h- Fig. 18
Cephazolin (20 mg/kg/8 h, i.v.) was applied for 3 days post op.
On the third post operative day -the dog was discharged, with oral Cimalgex (Cimicoxib, 2 mg/kg/day) for 14 days. Oral amoxicilin clavulonic acid (12,5 mg/kg/12h) was administered for 2 weeks and exercise was restricted to short walks on a leash for 12 weeks. The dog was re-examined regularly- every 14 days, including the visits for the chemotherapy sessions.
The histopathological diagnosis of the excised bone confirmed a grade II fibroblastic osteosarcoma (OSA)– Fig. 19. Surgical resection was considered complete with no evidence of neoplasia at joint compartment.
A single agent protocol -carboplatin (300 mg/m2)- Fig. 20, was planned and applied every 3 wk for a total of 5 treatments. The first treatment was started 2 weeks after surgery. A CBC was taken 2 weeks after and just before each carboplatin administration; serum biochemistry was performed every 2 months. There was no evidence of gastrointestinal upset, renal failure or myelosupression after chemotherapy. The AP levels were always in the reference range.
Clinical recovery and Follow up
Lameness progressively improved from toe-touching (one day after surgery) to full weight-bearing with only slightl visible lameness- 6 weeks post op. No external coaptation was applied during the recovery period- Fig.21, Video 2- 3.
Six months post op the limb function was appreciated as excellent, without any significant changes on limb palpation- Fig.22. Video 4. Orthogonal radiographs were taken, showing proximal bone fusion; distally the bone was superimposed by the lateral plate. No signs of construct failure were observed. A decision for dynamisation was made and the lateral plate was removed, revealing radiographically the bony structure under it. It showed good bone density and excellent graft fusion (primary), proximally and distally. Further segment hypertrophy is expected by the increased load sharing.
The limb sparing surgery could be a viable option for treating distal radial OSA in properly selected cases. With the innovative alternatives, the widely accepted approach to canine OSA – limb amputation treatment, should not be applied as “default treatment” in each case. Case to case individual approach may provide the pets and their owners more fare attitude. Excellent functional results of the limb may be achieved by a complex (but single stage) surgical segment resection and appropriate bone reconstruction and rigid fixation. The use of free vascularized bone graft is a manageable option and an alternative to ulnar-roll over in cases of distal ulnar tumor engagement or vast radial segments resection, where solid vascular bone grafting is demanded.
Disc herniation is a neurological disorder that is characterized by slipping nucleus pulposus outside of the space between the bodies of two vertebrae, the clinical appearance of intense pain in the area. Practical part or whole kernel pulposus (soft area of the intervertebral disc) herniates through a weakened area of the intervertebral disc annulus. Disc herniation can occur at any level of the spine, but the two most common sites are the lumbar and cervical. To establish a diagnosis of certainty indicated imaging studies: x-rays, CT, MRI, myelography. Nuclear magnetic resonance (NMR) is much more appropriate than CT in diagnosing pathologies of the spine. The obtained images are three-dimensional and thus very well both visualization column and nerve roots, and can determine the disease itself. Currently, MRI is the imaging method for diagnosing first intention herniated disk and can even be used in patients who have no clinical symptoms.
A 4 years old male, boxer weighting 24kg was present to us, after 14 days of tetraplegia; the debut being 6 months ago when it started difficult and heavy lifting from the bottom, neck pain when the steroid anti-inflammatory drug was administrated, the symptoms were resolved; 14 days ago tetraplegia was installed.
The animal presents a normal body temperature, its respiratory and cardiac frequency is within normal values, biochemical parameters and blood results is not modified. Neurological tests point out the tetraplegia, with persistence of profound sensibility and the absence of superficial sensibility. After neurological examination were also present: abolished patellar reflexes, flexor reflex abolished, tibial reflex abolished, absence correctional reaction, panicular reflex abolished , anal reflex present globe bladder.
An MRI was done at the Telescan, Timisoara, which pointed out a extrusion of the intervertebral C2-C3 (fig. 1/2).
Cervical Herniated Disc C2-C3
- Surgical Procedure
Surgical technique: ventral corpectomy, herniated disc extraction.
The dogs were anesthetized with a mixture of ketamine and xylazine (10 mg/kg and 15 mg/kg i. m.), Propofol (2 mg/kg) and artificially ventilated by a respirator with oxygen and monitored.
After trimming antisepsis field operator and 10% betadine solution, and took the subconjunctival tissue and skin incision, incision between the vertebrae C1-C4 (fig. 3)
After removing sternocephalic muscle, inferior thyroid artery is highlighted, (Fig 4/5) muscle sternohyoid that close side of trachea, esophagus, carotid, highlighting recurrent laryngeal nerve and muscle along the neck (Fig. 6)
The latter is detached the ventral tubercle of the affected disc space, resulting in highlighting the ventral face of the ring disk.
Discuss ring incision rise to the spinal canal, then extract the affected disc (Fig.7)
Hemostasis was secured with ultra incision Harmonic Scalpel(Fig.8)
- After surgery
Postoperative treatment containing corticotherapy 5 days, antibiotherapy 5 days and a bladder catheter the first 24 hours.
Surgery is commonly recommended on dogs that do not respond to medical treatment, have progressive clinical signs, or have more severe neurological deficits.
The efficacy of medical therapy may only be seen in patients that have minimal neurological deficits.
- After surgery evolution of the clinical case has been very good.
- 72 hours postoperative, the patient is able to move without any help. (Video)
- After two months postoperative the animal is completely healed, and does not manifest any neurological symptoms.
- The success rate with surgery is generally high provided that the spinal cord hasn’t been compressed for a long time (chronic spinal cord injury). Chronic cord injuries can be treated successfully with surgery, but the outlook is less favorable than it is for short-term (acute) injuries.
Veterinary Clinic Blue Cross
Case presentation: a 3 and a half year old female pug dog was presented at the Bluecross Veterinary Clinic in Sofia for additional diagnostics in view of resently started seizure events.
A month ago the dog started having problems with its hind left limb and another vet started him on prednisolone. The limping improved but 20 days later the dog started having seizures.
The patient was examined at the Bluecross Veterinary Clinic in Blagoevgrad within two hours after one of the seizures. At that stage the dog wasn‘t able to see properly and showed a tendency to circle to the left. Blood was taken for Cbc and biochemistry analysis and the results were normal. The patient was started on an antiepileptics drug – Phenobarbital and the steroids were continued (because of the high possibility of an inflammatory process). An examination at the clinic in Sofia and additional advance imaging were scheduled.
good general condition, slight difficulties in breathing (because of the brachiocephalic syndrome), normal heart and lung sounds, normal temperature.
Neurological examination: a little overexcited behaviour (but it was impossible to tell if this behaviour was abnormal for the dog or not). Normal cranial nerve reflexes, no nysgmus or circling, normal pupillary light reflexes. There was slight spinal ataxia in all four limbs. The proprioceptive tests were normal on all four. On the hind left limb the dog has pattelar luxation second degree (this explains the limping epizode a month ago). From the video provided by the owner it could be observed that the dog was demonstrating clonic- tonic seizure.
The owner was questioned for possible toxins, drugs and plants that could be the reason for the seizures but he said that the dog couldn’t have eaten anything abnormal.
A forebrain lesion was localised but the possibility of a multifocal process was very high.
The blood results were normal; therefore, possible extracranial reasons for the seizures were excluded. Toxin exposure was excluded by the anamnesis.
The list of differential diagnoses was:
- Inflammatory process – Necrotizing Meningoencephalitis (NME or Pug encephalitis)
- Idiopathic epilepsy
- Brain neoplasia
- Congenital lesion- hydrocephalus, cysts
To exclude most of the diagnoses from the list, advance imaging was performed – MRI 1,5tesla was used. The test was done with and without contrast material.
On the MRI we discovered a bilateral enlargement at the cranial part of both lateral ventricles within the frontal lobe of the brain. There was a visible communication between the ventricles and the subarachnoid space at the level of the eyes. They looked like cystic lesions filled with CSF. Bilateral loss of brain tissue was observed in both hemispheres. Around the cavities the cerebral cortex was reduced. These bilateral lesions could explain all the clinical signs that this dog was showing – seizures and the ataxia of all four limbs. There are motor cortex within the frontal lobe of the brain. There was no contrast enchantment after injection of contrast material within the brain tissue.
Therapeutic plan: the dog antiepileptic treatment was continued and regular measurements of the level of phenobarbital were scheduled. I added proton pump inhibitor –Esomeprazole (S enantiomer of omeprazole) because the drug has the effect of reducing the cerebrospinal fluid production. The steroids are slowly taped and they will be discontinued after two weeks.
The dog’s condition will be monitored by the owner and the vets at the BlueCross Veterinary Clinic in Blagoevgrad. In case of progression, especially after we stop the steroids, the necessity to take a CSF sample in order to finally exclude an inflammatory process is being discussed with the owner.
Porencephaly is a rare congenital cerebral defect and it is described in several reports in the field of veterinary medicine. It is more commonly seen in ruminants but there are few reports about dogs and cats.
There are few cystic congenital lesions of the brain, including focal lesions (porencephaly), extensive lesions (hydranencephaly) and very rarely schizencephaly (more commonly seen in humans). In porencephaly the defect creates a communication between the lateral ventricles and the subarachoid space. In schizencephaly the defect may be surrounded by a ring of polymicroglia. The schizencephalic defects are lined by gray matter.
The most frequent classification of these lesions based on their pathogenesis divides these defects into two major categories: developmental and encephaloclastic. Developmental porencephaly is due to a focal neuronal migration disorder, leaving a gap in the developing cerebral hemisphere. Encephaliclastic porencephaly includes cerebral cavities that result from tissue breakdown of various etiologies (cerebral ischemia, infection, trauma). In utero infection is the most common reason, especially in ruminants.
The interesting thing is that this type of lesions are congenital in nature but the clinical signs can start after the birth of the animal (which should be expected from the age) or sometimes later in life (after a few years).
According to the few reports about this type of pathology, the progression of the disease is different in every case. Some of those are completely asymptomatic, other cases are well controlled with drugs (antiepileptic drugs) third – their condition worsened, with poor control on drugs and some of those were euthanized. There was one report on a case of hydranencephaly where a ventriculoperitoneal shunt was placed and the dog’s condition slightly improved. Therefore, this is also a therapeutic option in some of those severe cases.
- Porencephaly and cortical dysplasia as cause of seizures in a dog: Gisele Fabrino, Maria-Gisela Laranjeira, Augusto Schweigert and Guilherme Dias de Melo BMC Veterinary Research 2012
- Porencephaly and hydranencephaly in six dogs: Davies ES1, Volk HA, Behr S, Summers B, de Lahunta A, Syme H, Jull P, Garosi L. Vet Rec. 2012 Feb
- Porencephaly in dogs and cats: Magnetic resonance imaging findings and clinical signs: Schmidt MJ1, Klumpp S, Amort K, Jawinski S, Kramer M. Vet Radiol Ultrasound. 2012
- Porencephaly in dogs and cats: relationships between magnetic resonance imaging (MRI) features and hippocampal atrophy: Ai HORI, Kiwamu HANAZONO, Kenjirou MIYOSHI and Tetsuya NAKADE, J Vet Med Sci. 2015
Dr Dimitar Ivanov,
Veterinary surgeon, Neurology specialist
Dobro hrumvane veterinary clinics
Dog, Bleki, toy terrier, M, 5 yo.
Came in the clinic on 11.04.2017 with left circle movements, menace deficit on the left and no reaction when stimulating the nasal mucosa. On the right, spinal reflexes are decreased and there are no conscious proprioception.
Doubt for brainstem problem.
V – vascular – it’s with peracute onset
I – inflamatory – it’s possible but no changes in blood sample
T – toxic – The dog did not take any medication, fed the same food and was not seen taking unusual things, but it’s not unpossible
A – anomalous – тhe dog is 5 years old and it is unlikely that there will be any manifestation of these diseases
M – metabolic – there is no other clinical signs or any changes in blood samples.
I – idiopathic – there is no seizures and vestibular signs
N – neoplastic – it’s more possible
D- degenerative – the dog is too young for cognitive dysfunction and too old for other degenerative diseases.
We made MRI on 12.04. and found a lesion in the left mesencephalon.
The final diagnosis is neoplasia in left midbrain.
We started to prepare for surgery.
The antibiotic preoperative was Ceftriaxone 30 mg/kg i.v., Manitol 1 g/kg i.v. and Methylprednosolone 20 mg i.v.
The surgery was on 22.04.2017 and we made a left craniotomy and displacement of the temporal lobe dorsolaterally until the lesion was reached.
Bleki preoperative video:
The skull was open and we enlarged the hole with Kerrison rongeur (pic 1 and 2)
We aspirated the brain liquor and very slowly reverse the left temporal lobe.( Pic 3 and 4)
When we found the lesion we punctured the cyst formation and drew the liquid contents.( pic 5)
The reason to do this surgery was to try to reduce the pressure in the tissue and to improve the dog’s condition.
After surgery we continued the antibiotics in the same dose and methylprednisolone in the same dose for three days. After then the dose was reduce to 2 mg /kg. After few days the methylprednisolone was change with prednisolone and started to reduce the dose.
Until the methylprednisolone is reduced, the patient is better every day, improves motor activity, appetite, but fails to maintain a constant temperature. A corneal ulcer of the left eye appears – I guess the cause is a trauma to the left oculomotor nerve and reduced lacrimation.
On 28.04. we included one more antibiotic – amoxicillin with clavulonic acid.
On 29.04. the prednisolone was reduced to 0,5 mg/kg, the dog was with anisocoria (myosis on the right eye and mydriasis on the left). On 30.04. the circle movements on left started again.
We tried to find Lomustine for chimiotherapy but we couldn’t and increased the dose of the prednisolone to 2 mg/kg
Bleki 22 days after surgery:
Bleki 23 days after surgery
The dog is good, he walk normally but when he stops, he start to make circle movement on the left.
- Loncar, DVM1
- Hadzic, DVM2
1,2 Department of Orthopedic Surgery and Neurology, Veterinary Clinic Novak, Belgrade, Serbia
An 8,5 years old miniature schnauzer dog was presented at the clinic with finding of right hind limb monoparesis and grade 1 lameness. CT diagnostic study was done but it was suggested that there was no visible lesions. MRI study shoved a lesion consistent with PNST. The dog was treated surgically and the tumor was excised completely with large margins. The dog recovered completely. The purpose of the article is to suggest that a lesion consisted with PNST distal to the stifle an elbow can be treated with large margins and very good motility of the limb afterwards. This type of pathology can be often missed with orthopedic conditions.
A 10 kg BW, 8,5 years old miniature schnauzer was presented at the clinic with owners complain of lameness on right hind limb for last five months.
At previous vet the dog was submitted to complete orthopedic, radiography and CT study with no diagnosis after the diagnostic workout. The dog was treated with 20 days of NSAID therapy (carprofen 2mg/kg BID 10 days and the dosage was reduced by half for the next 10 days). There was no improvement so the dog was treated with prednisolone for 20 days SID with again very little improvement.
The dog doesn’t have any important data in medical history.
At the presentation in our clinic:
During the walk dog showed grade one lameness.
At the clinical examination the dog showed normal proprioception but reduced withdraw reflex on right hind limb. During palpation region of gastrocnemius muscle was markedly painful. The rest of nurology and orthopedic examination was in within normal limits.
Figure 1. and 2.
There is a focal dilation of a vascular structure, presumably a vein, caudal to the medial aspect of the right stifle. The vascular dilation/aneurism has a maximal diameter of 7.7 mm and extends over a distance of approximately 4 cm. Contrast filling of the dilated area is heterogeneous with some areas lacking contrast filling. The affected vessel is an anastomosis/branch between the caudal branches of the saphenous vein and the caudal proximal femoral vein.
Figure 3. T1+contrast: On the right limb at the level of tibial nerve there is a lesion with heterogeneous contrast intake in long contact with blood vessel. The lesion is 3 cm long in diameter.
Figure 4. T1+contrast: Lesion at the level of tibial nerve in close contact with saphenous vein and the caudal proximal femoral vein. Heterogeneous contrast intake.
The surgical approach was made from medial side at the level of proximal part of gastrocnemius muscle. The careful identification of blood supplies and nerve structure was needed. The healthy proximal and distal part of the nerve was identified and the excision with 3 cm margins has been done.
The dog was treated post operatively with antibiotics for 7 days (cephalexin 15mg/kg BID), fentanyl patch for 3 days, carprofen 2 mg/kg BID for 7 days, gabapentin since 3th day 20 days 10mg/kg TID.
Neurological exam has been done after 1,3,6 and 12 months. The only abnormal finding 6 and 12 months post op was longer ground phase during walk and reduced withdraw reflex.
Tibial nerve is in charged for the motor function of caudal aspect of tibia and fibula. Deficit in function shows clinical signs that look similar to orthopedic conditions. Ground phase is longer, calcaneus drops distally more than in contralateral limb. Sometimes we can see plantigrade stance. Orthopedic conditions similar to these in term of signs are pathology of Achill’s tendon and tarsus and metatarsus.
PNST if at the distal part of peripheral nerves can be treated with good outcome. The reasons are fewer functions that lead in less of dysfunction of the limb, and good surgical margins. If PNST is localized at plexus or nerve root, 78% of dogs are going to be euthanized. The prognosis depends on localization and histopathology grading.
This article shows how close sometimes can be neurology and orthopedic clinical findings. Even if advanced imaging is available the cruciate information is localization of the lesion during the clinical examination. Further a right interpretation of images is necessary to define the lesion. PNST is an important differential diagnosis in investigation of distal extremities dysfunctions.
Marko Novak, dvm
Department of Orthopedics and Neurology
Klinika Loka, refferal small animal clinic, Škofja Loka, Slovenia
Luna is a lively 1,5 year old German Boxer, weighing 28 kg. She was presented to us with chronic intermittent right front leg lameness of grade II lasting for almost a year. Her owners noticed a lump on her medial carpal site. The dog had a history of a car accident when she was only six months old. At that time Luna was treated conservatively with NSAIDs and rest. Luna became worse after time and she was reffered.
Carpal joint is a hinge joint. It is composed out of six carpal bones that are arranged in a proximal and distal row forming three levels of joint spaces; the antebrachiocarpal where most of the joint motion takes place, the middle and the carpometacarpal space.
Joint`s stability is provided by ligaments of the carpus. Carpal ligaments are very stiff and short mostly crossing only one joint level. (image 1), (1)
Luna was afebrile, lame on her right front limb, grade II. Her right front limb was shaking while standing and her carpal joint was slightly flexed. Right carpal joint was obviously swollen on the medial side. Carpal range of motion was mildly decreased in flexion, distinct pain was observed on flexion of the carpal joint and by pressing on the firm medial swelling. No apparent instability could be observed while doing clinical exam but only slight valgus. The rest of physical and neurologic exam was normal.
Orthogonal and stress radiograms of both carpal joints were made and beside increased opacity of medial carpal soft tissue, extensive mineralisation near medial carpal compartment was noticed most apparently on the craniocaudal view. Stress radigraphs showed moderate instability on the medial side of all carpal joint levels. (image 2 to 4)
Decision in making the right therapeutic approach was difficult. After taking under consideration all of the data especially chronicity of the problem, we advised the owners do a pancarpal arthrodesis. Chronic instability is by far the most common indication (in 76% of the cases) for (pan)carpal arthrodesis. (2)
We could also try to do a synthetic ligament reconstruction but since the problem was present for almost a year, the instability was present in multiple medial carpal levels and the dog did not improve, arthordesis seemed like a prudent decision.
Hybride pancarpal arthodesis locking plate (Veterinary instumentation) (2,7 – 3,5) was used for the procedure, taking care to cover 75 % of third metacrapal bone, which resulted in a strong stabile environment and rapid healing with quick return to good postoperative function. External coaptation with a splinted bandage added extra support for the first three weeks after procedure. (Image 5 and 6)
Luna did have some problems with compensation for the first two weeks after the splint was removed, but than started to improve consistently. Follow up xrays at 4 and 8 weeks were unremarkable.
Luna is a very active young German Boxer who was intermittently but progressively lame for the last year. A chance to reconstruct the torn medial ligaments of carpal joint was probably unknowingly lost when the instability was missed at the first veterinary visit almost a year ago.
Chronic instability is seldom succesfully solved by synthetic reconstruction which purpose is to achieve good and functionally strong stability. Unsatisfactory surgical stability again leads to pain and degenerative joint disease.
Dispite apparent instability prooved on xrays, we were not sure how much it contributed to a development of chronic tenosynoviitis but we presume that the proximity of two structures resulted in abductor pollicis longus tendinopathy as well or differentially looking could also be a sign of an old avulsion fracture.
1 Fractures and Other Orthopedic Conditions of the Carpus, Metacarpus, and Phalanges, Part II: fractures and orthopedic conditions of forelimb, in BRINKER, PIERMATTEI, AND FLO’S HANDBOOK OF SMALL ANIMAL ORTHOPEDICS AND FRACTURE REPAIR, Fourth Edition, 2006, by Elsevier Inc., page 382, chapter 14
2 Pancarpal arthordesis in a dog: a review of forty-five cases, Robert B. Parker, DVM, S. Gary Brown, DVM and Alida P. Wind, DVM in American Collegue Of Veterinary Surgery.
In our experience most of the patients with TTA surgery are large breed dogs between 25-45kg. We heve had experienced to work with gient dog (70kg Neapolitan mastiff) and very small dog (6kg Poodle). Furthermore, the expectations before surgery were that the bigger dog will be a problem for setting the implants, but after both surgeries we were surprised how difficult was to set all implants into the smaller dog. Making the plane of TTA surgery for small dog our biggest concern before the surgery of poodle was how we would cut the bone, but that part was easiest of the surgery. Placing the cage and screws was the real challenge. The toughest job was insert the fork into the TTA plate that took most of the time of surgery. Overall, TTA would be the first chouse for ACL rupture in dogs.