Name:
Rotating Hinge Knee ( RHK ) for Dislocated Spacer by Dr. Anoop Jhurani
Description:
Rotating Hinge Knee ( RHK ) for Dislocated Spacer by Dr. Anoop Jhurani
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/c6311060-4faf-4a4b-9142-14ff13b10bb0/videoscrubberimages/Scrubber_1.jpg
Duration:
T00H11M57S
Embed URL:
https://stream.cadmore.media/player/c6311060-4faf-4a4b-9142-14ff13b10bb0
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/c6311060-4faf-4a4b-9142-14ff13b10bb0/Rotating Hinge Knee ( RHK ) for dislocated spacer by Dr. Ano.mp4?sv=2019-02-02&sr=c&sig=j21jh3Qbs9Qxr7Hg4tnT%2BUaBMdKPjc2F%2BiJZ1bw70UE%3D&st=2024-11-21T13%3A59%3A09Z&se=2024-11-21T16%3A04%3A09Z&sp=r
Upload Date:
2024-05-31T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
ANOOP JHURANI: Hello, friends. This is a video about revising a spacer to RHK, that is a rotating hinge prosthesis. Now, as you can see, this is a twice infected knee and explanted twice, divided twice, and a spacer twice. So this is a second spacer, which we put about six months back and now the ESR and CRP are normal. The spacer has dislocated, and what that also means is that there will be a lot of ligament incompetence.
ANOOP JHURANI: Both the MCL and the lateral collateral will be incompetent because the spacer is dislocated, the gaps will be quite out of balance and because of debridement twice the patient is obese as well. So this is a case for rotating hinge type of prosthesis and this video will focus on principles and technique of the rotating hinge RHK type of prosthesis and how to implant it. Now regarding the spacer, the spacer exploitation will also require meticulous soft tissue dissection and careful exploitation of the femoral side as well because the spacer is dislocated.
ANOOP JHURANI: So be careful that we don't cause any damage to the neurovascular structures and the explantation first of all will be easy, but the dissection has to be meticulous and slow and patient. So the first step will be to expose the knee through a medial parapatellar incision. There are multiple incisions on this knee, as we'll see in the video as it moves along. And we'll take the most medial one because that's the most recent.
ANOOP JHURANI: And we'll just go along very carefully, ensuring that there is no soft tissue interval between two incisions so that there is minimal chance of any wound necrosis. So here you can see the patient dislocated spacer. She's on the heavier side, she's obese. Those are the incisions that you can see. There is a most lateral incision, then there is a midline incision and then there is the medial incision.
ANOOP JHURANI: Now, ideally speaking, we should be taking the most lateral one, but here we'll take the medial one because the lateral one is too lateral and the medial one is puckered and is adherent. So we'll take the medial-most incision. So that's the medial-most incision and then the spacer comes out, and... You can see that the vastus medialis is completely moved medially, because the spacer has dislocated laterally.
ANOOP JHURANI: So that's a challenging exposure. The soft tissues are adherent and managed to be really gentle. Layer wise, dissection has to be done otherwise there are heavy chances of wound necrosis. So there you can see clearance of the gutters. The gutters are very important to clear and once the gutters are clear, that is the time that then we gradually start explanting the spacer.
ANOOP JHURANI: So that's removal of the tibial part. And we take deep cultures again and send it for microbiological examination to see the cells per high power field. There's a dissection of the whole tibia. We're coming at the back of the capsule and dissecting the whole tibia.
ANOOP JHURANI: Now, one option is to reconstruct this with sleeves and a rotating hinge type of prosthesis. But the availability in our part of the country is a little difficult so we instead choose to go with RHK, that's the explanted spacer. You can see the gaps now, the gaps are very big, and you can see that the medial collateral ligament is compromised, attenuated, so is the lateral collateral ligament because of two surgeries.
ANOOP JHURANI: And the extension gap is very big, so extension gap is roughly three fingers and flexion gap is two fingers. There you can see the gap and you can see the bone defect also. Now, there is the preparation of the stem first and the stem has to be really snug fit. We have to really get the diaphyseal purchase. As I said, you can, another option is to prepare with the sleeve.
ANOOP JHURANI: But this is another technique of doing the same operation, using the RHK type of prosthesis with good diaphyseal purchase of the stems. Minimum resection of tibia, just to correct the varus deformity, the varus angulation of the bone, just a millimeter or two, cutting from the lateral side. So that the stem is not in varus or the component or the overall alignment is not in varus.
ANOOP JHURANI: So there you can see we'll just cut a little bit from the lateral side to make a flat surface. And that will finish the preparation for the tibial. Then the stem preparation, we are opting for long diaphyseal stems, which really take good solid purchase in the diaphyseal bone. So this will be a 14/150 stem.
ANOOP JHURANI: Then comes the tibial perforation and the size of the tibia we choose so that there is no overhang of the tibia and proper lateralization, and then the broaching for the...
ANOOP JHURANI: ...for the peel}. Now comes the femur. The tibia component is trial is in situ, and we continue with the femur fixing the distal femur jig, just a millimeter of cut just to correct the valgus alignment. So basically there is no cutting in revision situations, it's just freshening the surfaces perpendicular to the mechanical axis, that's all.
ANOOP JHURANI: Then the size of the femur and the jig is fixed on the anterior surface, and we downsize the femur because the flexion gap is tighter than the extension gap, so we downsize the femur, that will also prevent any overhang and... will help us ensure gait balance. So now we just take a millimeter or two of the posterior condylar cut, whatever it takes.
ANOOP JHURANI: Not much cuts, just aligning the prosthesis perpendicular to the mechanical axis. That's reaming for the broad part of the RHK prosthesis. The stem on the femur is 16 millimeters, usually 16 on the femur and 14 on the tibia is usually the size, but it can go to 18 and 16 also in male patients.
ANOOP JHURANI: So this is a female patient, so 16 on the femur, 16/150 on the femur, 14/150 on the tibia. There you can see cutting a little bit of the lateral side and showing that the external rotation is good, millimeter or 2 from the posterior condyles. Just removing the bone of the posterior condyles.
ANOOP JHURANI: Then preparation for the box. The box is deeper, as you can see in this case, RHK box is deeper. And, to take for the rotating hinge. {INAUDIBLE} So don't cut much.
ANOOP JHURANI: Then we trial with the femur and the tibia, and with a 12 poly first, 13 poly first, and then see what happens. And that's the final prosthesis, you can see the stems, the hinge part on the femur, the 150 stems on the femur and tibia, and the tibial part is also the diaphyseal part, the metaphyseal part is also broad, so it really takes very solid, good fixation on the tibia.
ANOOP JHURANI: So basically metaphyseal fixation is cemented, and diaphyseal fixation is press-fit snug. So that's the preparation of the femur, the interpretation of the cement and then press-fit of the stem. A little bit defect there is filled with bone cement on the anterior side, and then finally locking of the screw mechanism for the rotating pulley.
ANOOP JHURANI: And you can see that the limb is nicely extended, as movement about 100-110 degrees. Usually there is some limitation of movement because of dense, adherent, fibrous tissue, and lateral release of the patella to ensure good tracking of patella. There's the post-op X-ray, you can see snug fitting of both the stems, the tibia and the femur, and good alignment of the prosthesis and rotating hinge type of a prosthesis, periprosthetic reconstruction.
ANOOP JHURANI: And the cultures that we sent on the table were negative, cell count was less than 500 cells per high power field, it should be less than 3,000, And the cells per high power field, sorry, these cells per CC of fluid were less than 500. It should be less than 3,000 and cells per high power field were less than 10 in 5 given samples of, taken from various deep deeper tissues from intramedullary areas.
ANOOP JHURANI: So that's very important to ensure further infection, the patient has been infected two times, has been explanted two times, and we don't want any further infection. So that's the plan, executed, removal of the spacer and reconstruction with the rotating hinge type of a prosthesis, with snug fit stems, overall good alignment of bone, and hopefully there will be no infection this time.
ANOOP JHURANI: Thank you very much.
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