2 Clinical Cases


Figure 2.1(A) Preoperative: lateral view; (B) Preoperative: caudal/rostral view; (C) Postoperative: lateral view; (D) Postoperative: caudal/rostral view.


Surgery Report


Preoperative planning was conducted to assure a plate selection which would avoid screw placement into tooth roots. The patient was placed in the dorsal recumbent position. An approach to the rostral shaft of the right hemimandible was performed. The fracture was reduced and a 6-hole locking plate was applied to the ventral mandibular ramus so that accompanying screws would best avoid tooth roots. Either tooth roots or fracture line infringement could not be avoided for screw holes 3 and 4 so they were left empty. The plate was minimally contoured and screws were placed in the order 5–3–6–1. The incision was closed routinely.


Postoperative Evaluation of Fracture Repair (Figures 2.1C–D)




















Criteria Assessment Details
Alignment Optimal Radiographs, as well as postextubation observations, confirmed excellent dental occlusion.
Apposition Optimal The fracture line is not visible.
Apparatus Good There are only two screws both cranial and caudal to the fracture line. This was necessary to avoid tooth roots.

Follow-up at 6 Weeks (Figures 2.1E–F)



















Criteria Assessment
Alignment Unchanged
Apposition Unchanged
Apparatus Unchanged
Activity The fracture appears healed with minimal callus. There appears to be lucency around the tooth roots of the right 3rd and 4th premolars and the left lower canine. Dental cleaning and tooth extraction, as needed, were recommended.


Figure 2.1 (Continued)(E) Follow-up at 6 Weeks: lateral view; (F) Follow-up at 6 Weeks: caudal/rostral view.


Closed, Transverse Fracture of the Left Scapula


Signalment and History


An 8-month-old, intact, female Golden Retriever weighing 23 kg sustained multiple traumatic injuries following a motor vehicle accident. She had been treated for shock, pneumothorax, rib fractures, left brachial plexus avulsion, and liver trauma. She was referred to the surgical referral hospital 14 days following the accident when a fractured scapula was diagnosed. At that time the patient was recovering well from the other injuries.


Patient Assessment


This was a very young patient with robust healing potential. Injuries aside from the scapula were healing and the patient’s metabolic condition was good. Neurologic examination was within normal limits including sensation; suggesting normal function of the left brachial plexus. If there were a brachial plexus avulsion, the prognosis would be poor, as many, if not all, true brachial plexus avulsions do not recover to adequate function.


Fracture Assessment


Closed, transverse fracture of the glenoid and neck of the left scapula, proximally and medially displaced, and over-riding 4 mm (Figures 2.2A–B). The fracture was articular, which would suggest an internal fixation repair with accurate reduction and interfragmentary compression. The fracture was 14 days old and in this young dog, healing would already be underway. Reduction would be anticipated as difficult, and there may be cartilage damage, resulting in arthritis of the scapulohumeral joint.


Options for Repair Methods


Lag screw fixation of this fracture should be considered, as this would provide interfragmentary compression. Plate fixation with a DCP should also be considered because this would provide interfragmentary compression. This fracture was rather old and the patient was partially ambulating on this limb. Erosion of bone at the fracture line is likely to have occurred, making accurate and stable reduction difficult. In addition, the thin and soft scapular bone in this young animal is anticipated to give poor screw purchase when placed under compression. Locking plates would hold soft bone better, but would not provide compression across the articular fracture line.


Surgery Report


The patient was placed in the right lateral recumbent position and an approach to the body, spine, and acromion process of the scapula was performed. In order to expose the fracture, a partial elevation of the omotransversarious and acromial part of the deltoideus muscles was performed from the spine and acromion of the scapula. Fibrous tissue was removed from the fracture ends and the fracture was reduced and maintained in reduction with pointed reduction forceps. A 7-hole, 2.7 mm locking plate was contoured and applied to the scapula. The two most distal screws engaged the supraglenoid aspect of the fracture and the four proximal screws were positioned to penetrate the scapula at the angle of the spine and blade, taking advantage of dense bone at this location. Screw hole 5 was left open because of its location over a fracture line. The approach was closed routinely and the patient was placed in a spicca splint for 2 weeks.



Figure 2.2(A) Preoperative: lateral view; (B) Preoperative: cranial/caudal view; (C) Postoperative: lateral view; (D) Postoperative: cranial/caudal view.


Postoperative Evaluation of Fracture Repair (Figures 2.2C–D)




















Criteria Assessment Details
Alignment Sufficient There is a small step in the contour of the glenoid and a malformation to the shape of the glenoid, validating that the fracture was not (could not be) anatomically reduced.
Apposition Sufficient There appears to be good apposition at the fracture line.
Apparatus Sufficient There are two screws in the distal segment of the neck and glenoid. With a locking plate, more screws per bone segment would be preferable, but this could not be accomplished due to the size of the fragment. A lag screw could not be used, as it may interfere with those screws of the plate. In addition, the fracture did not anatomically reduce, resulting in questionable fixation stability. The proximal screws were placed close to the spine of the scapula to engage thicker bone.

Follow-up at 6 Weeks (Figures 2.2E–F)



















Criteria Assessment
Alignment There appears to be improved contour of the glenoid.
Apposition Unchanged
Apparatus Unchanged
Activity The fracture lines are no longer visible. There is minimal callus apparent in this image. The patient was allowed a slow return to activity.

Figure 2.2f


Figure 2.2 (Continued)(E) Follow-up at 6 Weeks: lateral view; (F) Follow-up at 6 Weeks: cranial/caudal view.


Closed, Short Oblique Fracture of the Humeral Condyle


Signalment and History


A 1.5-year-old, neutered, female Golden Retriever weighing 22 kg sustained right forelimb and right caudal limb fractures from a motor vehicle accident. The patient was initially treated with pain medications and intravenous fluids. Thoracic and abdominal radiographs were within normal limits. Neurologic examination was within normal limits.


Patient Assessment


This is a polytrauma case where soft tissue damage and increased risk of complications are frequent. Contributing to the risk of infection are increased anesthesia times for reparative surgery. This is a young, healthy patient with robust potential for healing. For simplicity, only the humeral fracture will be discussed.


Fracture Assessment


Closed, short oblique fracture of the distal 4th of the humeral condyle with a 2.5 cm by 1 cm butterfly fragment. Fractures of the humeral diaphysis are often difficult to repair due to the challenges of surgical approach and the required management of the large and complex forces placed on the humerus during postoperative ambulation. Of particular note is that the patient must carry additional weight-bearing on the fractured humerus as there is also a fracture of the ipsilateral caudal limb (Figures 2.3A–B).


Options for Repair Methods


External fixators would not be an appropriate choice. Unilateral fixators are not sufficiently strong and conventional bilateral fixators are not an option for fractures above the elbow (or above the stifle). An IM tie-in configuration could be considered, but such a construct may still not be strong enough and the external apparatus is difficult to maintain.


An interlocking IM nail is also not a suitable choice, as the distal fragment could not accommodate two distal screws.


Plate fixation with either a DCP or locking plate should be considered. A locking plate, especially those that can be contoured to the epicondylar ridges would be appropriate. Configurations might include two lateral plates; one positioned on the lateral epicondylar ridge and one medially. This would allow adequate screw purchase in the distal segment. Mechanically, plates on the medial and lateral epicondylar ridges would be better.


Alternatively, a medial plate, either locking or dynamic compression, could be used. A medial plate could be applied in dynamic compression or load sharing, although access to the butterfly segment would be more difficult.


Surgery Report


The patient was placed in the left lateral recumbent position and an approach to the distal shaft of the humerus through a craniolateral incision was performed. The butterfly fragment was reduced to the proximal segment and maintained in reduction with pointed reduction-forceps. The fragment was then stabilized with two 2.7 mm screws placed in lag fashion. A 2.7 mm cortical screw was applied in lag fashion to secure the fragment to the proximal segment. The remaining two fracture segments were reduced using Kern bone-holding forceps. A 12-hole 2.7 mm locking plate was contoured to the craniolateral aspect of the humerus. One screw was placed proximally in hole 2 followed by insertion of a screw distally in hole 10. The remaining screws were inserted, excepting in holes 4 and 8. Care was taken not to enter the olecranon fossa of the distal humerus. A second 12-hole 2.7 mm locking plate was contoured and applied caudal to, but paralleling, the first. Holes 4, 7, and 8 were left open.


A bone graft was obtained from the proximal humerus and applied to the medial fracture lines. The incision was closed routinely.


Figure 2.3a


Figure 2.3(A) Preoperative: lateral view; (B) Preoperative: cranial/caudal view; (C) Postoperative: lateral view; (D) Postoperative: cranial/caudal view.


Postoperative Evaluation of Fracture Repair (Figures 2.3C–D)




















Criteria Assessment overview Details
Alignment Optimal Anatomic reduction was achieved.
Apposition Optimal Interfragmentary compression was achieved across all fracture lines. Fracture lines could not be visualized on the medial cortex of the humerus suggesting that medial buttressing had been achieved.
Apparatus Good Although a single 2.7 mm plate would not be appropriate, pairing the plates was acceptable due to the shape of the plate. This increased the total number of screws on each side of the fracture and increased the AMI of the fixation construct. Placing a plate both medially and laterally would have provided greater fixation strength and stiffness, but also necessitated a trans-olecranon approach or a combined medial and lateral approach. Since a medial buttress was achieved with the use of lag screws, additional approaches were not necessary.

Follow-up at 9 Weeks (Figures 2.3E–F)



















Criteria Assessment
Alignment Unchanged
Apposition Unchanged
Apparatus Unchanged
Activity Callus has formed at the caudal, medial, and cranial cortical surfaces. The callus observed cranially appears elevated from the original cortex and may suggest fibrous tissue interference with bone growth or motion early in the healing process. The patient was slowly returned to normal activity.

Note:Case material supplied by Dr. Mary Sarah Bergh and Dr. Angell Thompson.


Figure 2.3f


Figure 2.3 (Continued)(E) Follow-up at 9 Weeks: lateral view; (F) Follow-up at 9 Weeks: cranial/caudal view.


Closed, Salter IV Fracture of Lateral Humeral Condyle


Signalment and History


A 2-month-old, intact, female English Bulldog weighing 10 kg sustained an elbow fracture when jumping from its owner’s arms the previous day.


Patient Assessment


This is a very young patient with soft, immature bones and considerable remaining growth potential.


Fracture Assessment


Closed, Salter IV fracture of the lateral humeral condyle, displaced laterally and over-riding 4 mm (Figures 2.4A–B).


Options for Repair Methods


This is an articular fracture and as such requires open reduction with rigid fixation and anatomic alignment. Transcondylar lag screw fixation with an additional anti-rotational supracondylar Kirschner wire is frequently used as fixation for these fractures. The fracture should be repaired as soon after injury as possible to prevent motion damaging soft bone and compromising a surgeon’s ability to reduce the fracture. Potential problems from compromised growth at the distal physis and the development of osteoarthritis is a concern.


Surgery Report


An approach to the lateral aspect of the humeral condyle and epicondyle was performed. The extensor carpi radialis was elevated off the cranial aspect of the epicondylar ridge and the anconeus muscle was elevated off the caudal aspect. The fractured capitulum (lateral aspect of the humeral condyle) was reflected laterally, hinging on the collateral ligament until the fracture segment was exteriorized. A 4.0 mm drill bit was then used to drill a hole from the fracture line, in a lateral direction, but distal to the visualized physis. A cannula with an outer diameter of 3.5 mm and inner diameter of 2.5 mm was place from lateral-to-medial into this hole. This cannula was used for leverage to help reduce the fracture. The fracture was subsequently reduced so that the fracture line at the epicondylar ridge and the cranial articular surface could be confirmed for accurate reduction. Pointed reduction forceps were then used to stabilize the fracture. A 2.5 mm drill bit was used to drill through the cannula into the trochlea (medial aspect of the humeral condyle). The cannula was then removed. The drill hole was measured and a screw slightly shorter than this measurement was chosen for placement to assure the screw did not protrude too far on the medial aspect of the condyle when seated into the lateral collateral ligament. A washer was also used with this screw, after considering the softness of this immature bone. A 4.0 mm tap was used to tap the medial aspect of the condyle, after which a 4.0 mm cancellous screw wish washer was placed in lag fashion. A 1.1 mm (17 gauge) Kirschner wire was drilled from the lateral epicondyle, up the epicondylar ridge and exited the medial aspect of the distal humeral metaphysis, with care taken to avoid entry into the supratrochlear foramen/olecranon fossa. The extensor carpi radialis was sutured to the anconeus muscle, followed by routine closure.



Figure 2.4(A) Preoperative: lateral view; (B) Preoperative: cranial/caudal view; (C) Postoperative: lateral view; (D) Postoperative: cranial/caudal view.


Postoperative Evaluation of Fracture Repair (Figures 2.4C–D)




















Criteria Assessment Details
Alignment Sufficient There is a small step at the articular surface. This may have resulted from soft bone collapse during lagging.
Apposition Sufficient The fracture line is visible and there seems to be a small gap. The epicondyle appears to be anatomically reduced.
Apparatus Good The screw appears to be placed below the physis and across the condyle. The Kirschner wire is appropriately placed up the epicondyle.

Follow-up at 7 Weeks (Figures 2.4E–F)



















Criteria Assessment
Alignment The step in the articular surface, seen postoperatively, is not present and appears to have remodeled.
Apposition The fracture line is no longer visible.
Apparatus The screw and wire are basically unchanged in position. There appears to be some lucency around the washer.
Activity Minimal callus formation is present. The fracture lines of the condyle and epicondylar ridge are no longer apparent. The condylar physis appears to be closed and the condyle has a normal appearance. There was good range of motion. The patient was allowed to return to normal activity.

Figure 2.4f


Figure 2.4 (Continued)(E) Follow-up at 7 Weeks: lateral view; (F) Follow-up at 7 Weeks: cranial/caudal view.


Closed, Oblique, Articular Fracture of the Olecranon


Signalment and History


A 7-year-old, neutered, male Labrador Retriever Mix weighing 43 kg sustained a left forelimb injury from a motor vehicle accident.


Patient Assessment


The patient was admitted in generally good health. Thoracic and abdominal radiographs were within normal limits. The forelimb had not sustained severe soft tissue damage. Although an older patient, there should be no compromise to healing potential.


Fracture Assessment


Closed, oblique, articular fracture of the olecranon, proximally displaced less than 5 mm. One small, single fragment comminution at the distal fracture line is present (Figures 2.5A–B).


Options for Repair Methods


External support would not be appropriate due to the distracting pull of the triceps, the fracture being articular and the proximal location of the fracture in the ulna. The olecranon is under tension from the triceps. As such, a method which includes a tension device should be chosen to redirect tensile forces into compressive forces. The fracture was also articular, therefore it must be anatomically reduced at the articular surface. A tension-band device with pins and cerclage wire would be an option, but it is difficult to position these devices so that the pins reduce the fracture properly and stay rigid. The proximal pins and cerclage wire must be positioned so that they do not impinge the triceps tendon. Plate fixation, preferably with dynamic compression, could be performed; and, if positioned sufficiently caudal, could act as a tension-band device resulting in compression.


Surgery Report


The patient was placed in the dorsal recumbent position and an approach to the tuber olecranon was performed. The fracture was reduced and a 7-hole locking plate applied to the lateral aspect of the ulna. Screws were applied in buttress fashion in the order 2–6–1–3–5–7.



Figure 2.5(A) Preoperative: lateral view; (B) Preoperative: cranial/caudal view; (C) Postoperative: lateral view; (D) Postoperative: cranial/caudal view.


Postoperative Evaluation of Fracture Repair (Figures 2.5C–D)




















Criteria Assessment Details
Alignment Good The fracture was anatomically aligned.
Apposition Insufficient A fracture gap can be seen at the articular surface. A fragment of (comminuted) bone has been removed from the caudal-distal aspect of the fracture line.
Apparatus Sufficient A locking plate was selected that holds the bone fragments in position and provides buttress support to the fracture. The olecranon is under tension from the pull of the triceps. It should be noted that unless the plate is sufficiently caudal and elastic, and the fracture line is allowed to undergo compression, the plate may cause high interfragmentary strain on the small fracture gap observed. This can lead to delayed union and shear stress, depending on the pull of the triceps.

First Follow-up at 7 Weeks (Figures 2.5E–F)



















Criteria Assessment
Alignment Unchanged
Apposition The fracture line is more distinct especially at the articular surface.
Apparatus Unchanged
Activity There is little callus present. This is probably due to high interfragmentary strain with the plate insufficiently acting as a tension-band device. The implants are stable and there may be some areas of bridging bone close to the plate. If there is a boney bridge, then the fracture is likely to heal.

Final Follow-up at 12 Weeks (Figures 2.5G–H)



















Criteria Assessment
Alignment Unchanged
Apposition Unchanged
Apparatus Unchanged
Activity Although the fracture line can be seen, there appears to be bridging bone throughout the fracture line, excepting the distal most aspect of the fracture line, which had a bone fragment removed. The patient was slowly returned to normal activity.

Figure 2.5h


Figure 2.5 (Continued)(E) First Follow-up at 7 Weeks: lateral view; (F) First Follow-up at 7 Weeks: cranial/caudal view; (G) Final Follow-up at 12 Weeks: lateral view; (H) Final Follow-up at 12 Weeks: cranial/caudal view.


Closed, Transverse Fracture of the Right Radius and Ulna


Signalment and History


A 3-year-old, neutered, male Yorkshire Terrier weighing 4.5 kg sustained a fracture to the right radius and ulna whilst playing with other dogs.


Patient Assessment


This is a relatively young dog, but it is a miniature breed known to be at risk of delayed healing of fractures to the radius and ulna.


Fracture Assessment


Closed, transverse fracture of the distal 3rd of the right radius and ulna, angularly displaced cranially but not over-riding (Figures 2.6A–B). Please note in human medicine, the term Colles’ Fracture describes a fracture at the distal end of the radius.


Options for Repair Methods


Fractures of the radius and ulna in miniature breed dogs are often transverse and can occur from minimal trauma due to the small size of the bone and small AMI. There is also scant soft tissue coverage, small IM space and low biological activity. As such, primary bone union would be preferred. With secondary bone union, the biological environment is challenged to establish a callus. Because primary bone union is the goal, dynamic compression plating would be a first choice. All efforts should be made to place the plate in dynamic compression so as to allow axial load-bearing during the healing period. Other plating techniques could be considered such as cuttable plates or plates acting in buttress, including locking plates. External fixation techniques, such as ring fixators, can be successfully used in such cases, although complications are common. External support with a cast or splint is not recommended. Casts/splints do not provide sufficiently rigid fixation for primary bone union and they suppress secondary bone union. Non-unions are frequent when external support is utilized. When considering internal plate fixation, all efforts should be made to engage six bone cortices with screws on each side of the fracture. Fractures can be very distal, allowing only four cortices of purchase, which is not optimal. However, in some cases, there are no alternatives. T-plates can be used to allow the maximum number of distal cortices in very distal fractures. Bone grafting is also recommended.


Surgery Report


The patient was placed in the dorsal recumbent position and a 1 cm incision was made over the greater tubercle of the right humerus in order to harvest a bone graft. The outer cortex was penetrated with a 3.2 mm Steinmann pin. A 3-0 curette was used to remove cancellous bone which was transferred to a syringe barrel. Approximately 0.25 ml of cancellous bone was obtained. This incision was closed. An approach to the shaft of the radius through a medial incision was made. The fracture was reduced and a 7-hole, 2.0 mm LC-DCP plate was contoured to the cranial aspect of the radius. Upon observing cortical contact on the caudal aspect of the radius, a slight pre-bend of the plate enabled the plate to rise above the fracture line by approximately 0.5 mm. A 2.0 mm screw was positioned into screw hole 5. That screw was inserted loosely so that the plate could slide cranially. A 2nd screw was then inserted under dynamic compression into hole 3. This effectively loaded one screw on each side of the fracture. Subsequent screws were inserted in sequence proximal to distal. The cancellous graft was placed caudal to the radius and the wound closed routinely.



Figure 2.6(A) Preoperative: lateral view; (B) Preoperative: cranial/caudal view; (C) Postoperative: lateral view; (D) Postoperative: cranial/caudal view.


Postoperative Evaluation of Fracture Repair (Figures 2.6C–D)




















Criteria Assessment Overview Details
Alignment Optimal The fracture is anatomically aligned.
Apposition Optimal The fracture line is compressed and not visible.
Apparatus Good The plate has been appropriately attached with compression of the 3rd and 5th screws. The plate could perhaps have been longer, with one more distal and one more proximal hole. The proximal limit of the applied plate is mid-radius. Depending on the stiffness of the plate compared to the stiffness of the bone, this proximal plate location could be a stress-riser. In small dogs, the choice of plate for optimal stiffness is not straightforward. If the plate is too stiff, the healing bone will be stress-protected; leading to delayed healing and osteoporosis. If the plate is insufficiently stiff, then the plate may fail. This can be due to plate bending or cyclic failure and plate breakage. The plate selected in this case appears to be appropriate for this patient.

Follow-up at 7 Weeks (Figures 2.6E–F)



















Criteria Assessment
Alignment Unchanged
Apposition Unchanged
Apparatus Unchanged
Activity The fracture line is not visible and appears healed. However, the ulna has not healed and appears to be progressing to non-union. This is not of clinical concern unless it is causing the patient pain. At this time it cannot be determined if the plate is too stiff although it is thought unlikely that a 2.0 mm plate would be too stiff given the size of the patient. If the plate is stress-protecting the fracture, then with the passage of time, the radius will become osteopenic. It is recommended that the limb is radiographed at 6-month intervals to follow the course of the remodeling. If the radius becomes osteopenic, then staged plate removal would be recommended.

Figure 2.6f


Figure 2.6 (Continued)(E) Follow-up at 7 Weeks: lateral view; (F) Follow-up at 7 Weeks: cranial/caudal view.


Closed, Transverse Fracture of the Left Radius and Ulna


Signalment and History


A 9-year, 8-month-old, neutered, female German Shepherd weighing 45 kg sustained a left radius and ulna fracture from a low-speed motor vehicle accident (snow machine).


Patient Assessment


Though almost 10 years old, the patient was in good general health. Thoracic and abdominal radiographs were within normal limits, as were other physical parameters. A splint was placed soon after the incident.


Fracture Assessment


On palpation, the limb was not unduly swollen or unstable. Forelimb radiographs revealed a closed, transverse fracture of the distal 4th of the left radius and ulna, displaced laterally and over-riding 1 cm (Figures 2.7A–B).


Options for Repair Methods


This transverse, non-comminuted fracture is an excellent candidate for a DCP. The fracture is reducible, not comminuted, and will allow true dynamic compression if the plate is applied appropriately. Primary bone union would be expected in the radius. The ulna is not weight-bearing and in most cases is not repaired.


IM pinning, casting, or locking nail fixation would be far less appropriate. Buttress fixation with a locking plate or external fixator could be effective, but would not be a primary choice as these fixation devices do not usually allow dynamic compression and are less able to allow axial loads to compress the fracture line with load sharing. High interfragmentary strain may occur with such buttress types of fixation.

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Feb 4, 2018 | Posted by in SMALL ANIMAL | Comments Off on 2 Clinical Cases
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