As you can see from the radiographs above there is maintenance of the limb length and alignment, along with stable implants and completely bridged fracture gap by maturing callus.
Despite these very encouraging radiographs, the dog's limb use is only fair at best at the moment, with marked atrophy and discomfort with hip extension and direct palpation of all of the muscles in the area. Thankfully, no evidence of quadriceps tie-down is evident and stifle flexion remains equal to the contralateral limb. Despite instructions to aggressively rehab the dog, the client had effectively been crating it and walking it only 10 minutes a day, which would explain the atrophy and muscle discomfort.
I have recommended the client initiate the rehab program provided and attempt to regain the muscle mass lost over the next 8-10 weeks. Repeat radiographs will be performed in 8 weeks to monitor the progress of bone remodelling.
]]>A lateral approach was made to the left femur. The open wound was debrided en bloc until healthy, clean tissue was observed. Bone fragments that had lost all soft tissue attachments were resected. The fracture hematoma was left in situ where possible.
A 1/4" Steinmann pin inserted proximal retrograde until it exited the intertrochanteric fossa. The Steinmann pin was then removed and a 6mm diameter IMPeek Rod inserted from proximal normograde across the fracture defect and into the distal segment to re-establish bone length.
A 14 hole Synthes LCP was then contoured to the lateral femur and affixed in a bridging fashion with 1 distal cortical screw and 3 distal bicortical locking screws. Proximally, 3 bicortical locking screws and a single monocortical locking screw were placed. Intentional attempts to drill through and engage the IMPeek rod was not performed, however 2 locking screws distally and proximally did happen to pass through and threaded into the IMPeek rod.
A left, proximal humeral cancellous bone autograft was then obtained and packed into the fracture defect. The soft tissues were closed at both sites routinely and post operative radiographs obtained showed excellent limb alignment and implant positioning.
The patient was walking on the limb with sling support the day after surgery and is scheduled to have sutures out in 2 weeks. I will post follow up radiographs here at 8 weeks.
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Images below show progressive resorption of the cranial and caudal butterfly fragments with re-establishment of a contiguous bone column beneath the plate. The fibula is healed by callus. The IMPeek rod remains in situ and implants appear stable and limb alignment maintained. Some progressive resorption appears around the proximal aspect of the rod, which likely represents micro-motion in this location rather than more serious etiologies like infection, of which there are no clinical signs.
Since the dog is clinically sound, the need for grafting seems excessive, so repeat imaging is being performed in 12 weeks to monitor progress.
]]>The image quality is suboptimal due to movement artifact and other digital radiographic gremlins, but what we do see is stable implants, a healed fibula, slow attempts at callus formation across the major fracture gap and progressive resorption of the cranial butterfly fragment. There is a radiolucent line around the IMPeek rod which is likely a digital radiographic artifact called the Uberschwinger effect. You can see all of these changes more prominently on the side-by-side comparison of the 16 (left) and 10 week (right) caudocranial images below.
The veterinarian reports the dog remains persistently weight bearing, but an intermittent lameness is still present after long walks and after prolonged rest. The client is very pleased with the outcome so far.
Nevertheless, this fracture would ideally be healed with aggressive callus at this point. In hind sight, bone grafting of the fracture gap should have been performed. I have recommended that we repeat imaging in 6 weeks time again, and depending on those findings, likely surgically revise the fracture gap and instill some autogenous bone graft and shorten the IMPeek rod which is a little too proud within the stifle.
Updates will be posted here in the future.
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The second case shows 14 week post op radiographs for our third clinical case, which was a grade 1 open, transverse, non reconstructable fracture of the left mid humeral diaphysis in a 3 year old MN cat. The cat is not confined at home, and is able to run, jump, play and groom itself without medication, pain or lameness appreciated as you can see in the video below. Excellent range of motion of the shoulder and elbow have been maintained.
Radiographs obtained show complete union of the fracture with stable implants and an unchanged IMPeek rod. There is no evidence of infection or implant complications, and the client, cat and surgeon are extremely happy with the outcome!
This case is a 10 year old male neutered dog, suffered a closed, mid diaphyseal, comminuted fracture of the left tibia approximately 14 weeks ago, but only recently we were sent the 10 week post op radiographs. The dog is reportedly persistently weight bearing, but a mild lameness persists.
There is no evidence of infection and the client thinks the dog is continuously improving with each passing week. 10 week post op radiographs (above) were obtained at the primary care veterinarian. The quality is not as good I as would like, but there appears to be some attempts at bridging across the comminuted fracture, but I would ideally prefer more bone activity this far post op. The implants are stable and the IMPeek rod remains intact and unchanged from the immediate post-op radiographs. Given the biological damage at the time of fracture and the age of this patient, in hindsight grafting with cancellous bone would have been prudent, but at the time I attempted a biological approach to the stabilization in order to avoid adding additional morbidity. The delay in union is also possibly due to the stiffness of the construct, as the screws interlock with the IMPeek rod, but this is considered less of a contributing factor than the need for bone grafting. At this point in time, I have recommended repeat radiographs in another 4 weeks. Pending those results we will then consider bone grafting to help stimulate additional bone healing if required.
]]>You may recall our second reported case; our pug friend Tonka. Tonka is reportedly doing well 3 weeks post op fracture repair of his left tibia using orthogonal plating and a 4mm IMPeek rod. He is reportedly persistently weight bearing, bright as a button and has had his sutures removed at his regular vet. The clients report that he is doing better each week and they're extremely happy with his progress so far. Recheck images are due in about 8-10 weeks from now. Stay tuned!
A few days ago we rechecked on our second cat fracture, and first humeral case 2 weeks post op. The client reports the cat has been doing fantastically at home since being discharged. About 5 days post op the swelling in the limb resolved completely and the cat started to instantly weight bear and even attempted to jump up on the bed.... :( Bad kitty! I certainly am happy the cat is doing so well, but I do not encourage that so early post op!
The incision had healed so we took out the sutures. The left humerus was pain free, had excellent range of motion at the elbow and shoulder, and no evidence of inflammation or infection. Just look how happy the cat is below! Our plan is for recheck radiographs in about 10 weeks.
Our final recheck update is on our dear old 10 year old male neutered Mastiff X who was accidentally run over by his owner and suffered a comminuted fracture of the left tibia. 3 weeks post op the client reported over the phone that the dog's incision had healed perfectly, the limb use was persistently improving and there was only a mild lameness appreciated at the moment. The plan is for repeat imaging in 8-10 weeks. Stay tuned for more updates!
]]>Our first case was a lovely little Siamese cat who escaped from his usual confines at home and went on an overnight bender. When he eventually staggered home however, he was nursing a rather bruised and battered left humerus. He was seen at the emergency clinic and referred for surgical repair of a grade 1 open, transverse, non reconstructable fracture of the mid humeral diaphysis. Neurological exam pre-op was normal and no other co-morbidities were appreciated.
A medial approach to the left humerus was performed. To facilitate accurate plate placement distally, the supracondylar foramen was rongeured off and the median nerve and brachial artery released from its confines.
A look, but do not touch approach was utilized for the fracture site as much as possible, thus ensuring the fracture hematoma was left intact. Sequentially larger metallic IM pins were then inserted proximal retrograde, from the fracture through the greater tubercle, until a 4mm IMPeek rod could be inserted. The IMPeek rod was then driven from the greater tubercle into the distal fragment to help maintain fracture alignment and bone length. A 10 hole, 2.4 mm LCP was then contoured and applied to the medial cortex of the bone and affixed with 5 locking screws and 1 (most proximal) cortical screw. The IMPeek rod was engaged at all screw holes to create an interlocking construct. This cortical screw use was due to the plate being angled a little cranially at the most proximal aspect of the bone.
Post op radiographs showed good alignment of the bone, restoration of the long axis and good implant placement. The cat was discharged 24 hours later with intact neurological status and was toe touching on the limb. Recheck is scheduled in 2 weeks.
In the second case in as many days, we saw a lovely 10 year old male neutered Mastiff X who had been sleeping quietly under the owner's truck trying to hide in the shade during an oppressively hot summer day. Unfortunately for everyone involved, the dog was not seen resting under the wheels and the inevitable happened when the owner tried to back the car up.
He was presented with a closed, mid diaphyseal, comminuted fracture of the left tibia.
A mini-medial approach to the tibia was made using proximal and distal skin incisions. The fracture hematoma was left in situ, preserving the biology of the area. The fracture was reduced by inserting sequentially larger IM pins proximal normograde via a mini medial stifle arthrotomy, until a 6mm IMPeek rod could be inserted into the medullary canal. Driving the IMPeek rod into the distal fragment helped to restore the limb length and alignment. A 14 hole, 3.5mm broad LCP was then contoured and affixed to the medial cortex using 6 locking and 1 cortical screw. The distal most mono-cortical screw on the medial malleolus had to be shortened and redirected to limit imposition on the tibiotalar joint.
The post op radiographs show restoration of the limb length and alignment, with good implant placement. The IMPeek rod could be recessed a little further or trimmed slightly in hind sight.
The healing progression will be posted here in the near future, so stay posted.
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Pre-operative repeat radiographs were obtained for planning purposes which revealed propagation of several fissures from the mid diaphysis cranially, proximally and caudally into the metaphysis, making this a comminuted fracture and plate repair alone insufficient. In the end, orthogonal plate-rod anatomic repair of the fracture was performed using 2 2.0 LCP plates and a 4mm IMPeek rod. Where possible, lag screw fixation was performed through the plate to reduce the fissured areas of bone.
Post operative radiographs show good implant placement, realignment of the limb and reduction of the fracture.
As our clinical expericence improves with each case, we find new tips and tricks to speed up surgery. In this case, we appreciated that smaller screws, like 2.0mm have a small cutting flute, so they have a hard time cutting their own thread through the IMPeek rod without stripping the head or binding up. Tapping the hole with a 2.0mm tap was a far more efficient means of getting screws through the rod and locked into the plate.
The dog was discharged the following day and will return for follow up in a few weeks.
]]>The client has been keeping the cat confined to a large crate and reports that the cat is pain free and ambulating normally.
As you can see in the video below, there is still a very mild lameness, but this is not unexpected given the fracture is still in the process of healing.
10 week post op rads show stable implants with progressive callus formation. The speed of the healing is also not unexpected given the damage to the biology, the fracture configuration and stiffness of the construct.
We will be obtaining additional images in 6 weeks and will post what we hope will be the final radiographs for this patient!
IMPeek rods are available for purchase here.
]]>You may remember our report of the first IMPeek case in a complex proximal tibial fracture in a cat about 6 weeks ago.
Our fist clinical case took a surprising turn for the worse 2 weeks after surgery. The client had failed to confine the cat as recommended and had allowed the protective Elizabethan collar to remain off after discharge from hospital. During this time the cat had been able to partially lick open the medial tibial incision and obtain a MRSP susceptible to marbofloxacin. On top of that, the cat had been able to jump onto and off furniture at home, leading to acute non-weight bearing at approximately the same time as the initial infection was diagnosed.
Radiographs (below) showed fissure propagation through the caudal half of the tibial metaphysis and caudal tilting of the tibial plateau due to quadriceps pull on the tibial crest. The LCP and IMPeek rod remain in place, holding together the otherwise unstable proximal fragment.
Revision was performed with wide excision of the open wound and a cranial approach to the tibial crest. A 2.0mm 12 hole LCP was contoured to the cranial tibia and affixed with a combination of cortical and locking screws, with the goal of engaging the IMPeek rod where possible. Unfortunately 2 drill bits snapped off within the bone and could not be retrieved. A bone allograft was used to stimulate bone healing. A closed suction drain was placed subcutaneously to help resolve the deadspace after wide excision of the infected tissue.
Strict confinement to a cage and 24/7 placement of the Elizabethan collar were prescribed along with appropriate antibiotics and analgesics. A lateral splint was applied for 2 weeks with weekly changes performed. The 2 week post op recheck showed a healed skin incision with no evidence of active infection. Limb use was considered good, with mild discomfort and lameness appreciated.
The 4 week post op recheck showed excellent limb use, no pain on palpation of the tibia and normal stifle range of motion. Progressive bone union and integration of the bone graft was appreciated. The implant position and bone alignment remain appropriate.
It is anticipated that this fracture will likely take another 6-10 weeks to completely heal, during which time repeat radiographs will be taken roughly every 4 weeks to monitor union.
We will repost in 4 weeks with updated images.
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A 6 year old male neutered Maine Coon cat suffered an acute trauma to the proximal right tibia after falling from a height in the owner's home. Open reduction and internal fixation was performed via medial approach to the tibial shaft, using a 2.4mm 14 hole LCP from Synthes, combined with a 4mm IMPeek rod placed in the medullary canal via a proximal normograde approach.
To facilitate insertion into the medulla, a 5/32" metallic pin was used to create an entry point in the cranial tibial plateau and path for the IMPeek rod to follow into the distal diaphysis. The IMPeek rod was then inserted slowly with a battery powered drill using the K-wire attachment. The blunt tip of the IMPeek rod helped to facilitate fracture distraction. A 14 hole LCP was then contoured to the medial aspect of the tibia and affixed with 3 screws into the proximal and distal fracture fragments in a far-near, near-far configuration to maximize construct strength whilst minimizing screw requirements. 5 of the 6 screws engaged the IMPeek rod to create an interlocking plate-rod construct.
A brand new drill bit was used along with a locking drill guide for the 5 locking screws. Extensive lavage and suction was utilized to minimize heat generation and to remove IMPeek debris. Due to the similar sensation of drilling through cortical bone and the IMPeek rod, gentle, consistent pressure was applied when engaging the rod to help prevent slippage off the side of the rod.
Once the holes were drilled, depth was measured with a gauge and screws inserted by hand. The sensation of screwing into the rod was similar to that of screw penetration into cortical bone. Lavage was again performed prior to cutting of the IMPeek rod with small double action wire cutters. Closure was routine.
The day after surgery the cat was ambulatory and was toe touching lame on the right hind limb. 2 week post op recheck showed persistent weight bearing on the right hind limb with a healed surgical incision and no discomfort on palpation of the tibia.
8 week post op radiographs will be posted when available.
]]>PEEK (polyetheretherketone) is a bioinert polymer which has similar properties to healthy bone when filled with carbon fiber and is commonly used in orthopedic products in both veterinary and human orthopedics.
PEEK exhibits excellent mechanical properties, is autoclavable, cuttable, drillable and screwable. This gives the surgeon unique capabilities in complex fracture repair that had otherwise been unavailable.
IMPeek rods come with a blunted tip to help maintain fracture end distraction and ease insertion. IMPeek rods are designed to be used in combination with plates and screws. Compared to traditional metallic IM pins, our recommendation is to place the largest IMPeek rod possible within the medullary canal so that:
Due to the ability to be drilled and screwed through, the surgeon never needs to worry about trying to miss the IMPeek rod - in fact it is beneficial. When an IMPeek rod is drilled through and then a screw inserted, the screw will cut a thread in the rod, creating an interlocking or 'tie in' like construct. This is particularly useful in complex scenarios like juxta-articular fractures.
Another key feature of IMPeek rods is that you do not require any special equipment to use them! Everything you need, you likely already have to be able to use IMPeek. The choice is yours - hand chucks or drills, pin cutters or saws, cortical or locking screws.
In a biomechanical study by Beierer et al (Vet Surgery, 2014), healthy tibiae were used to compare a plate-rod construct with 10 hole 3.5mm LCP in locking bridging mode with either a 6mm PEEK rod (75% medullary fill) or Steinmann pins (30-40% fill). The study found that PEEK rod constructs were significantly stiffer in compression, bending and torsion than the Steinmann pin constructs. The PEEK rod constructs were also significantly stronger, and yielded at loads ~4 times greater than the Steinmann pin constructs.
]]>IMPeek will offer you a unique, flexible and dynamic solution to complex fractures that you wish you had yesterday.