Rib hump reduction surgery seemed to trigger curve progression

[Pooka1]

I wonder if PT-based methods that seek to reduce rib humps have the same effect of triggering progression. If Schroth seeks to reduce the rib hump, maybe this explains the lack of evidence of efficacy to date though my bet is the lack of compliance has prevented any true test of Schroth on a meaningful scale.

http://journals.lww.com/spinejournal...ure_for.8.aspx

Isolated Percutaneous Thoracoplasty Procedure for Skeletally Mature Adolescent Idiopathic Scoliosis Patients, With Rib Deformity as Their Only Concern: Short-term Outcomes
Yang, Jae Hyuk MD*; Bhandarkar, Amit Wasudeo MBBS, MS*; Kasat, Niraj Sharad MD*; Suh, Seung Woo MD, PhD*; Hong, Jae Young MDâ€*; Modi, Hitesh N. MS, PhD*; Hwang, Jin Ho MD‡

Abstract
Study Design. Prospective case series study.

Objective. To study the effect of percutaneous thoracoplasty–only procedure on curve pattern in mature adolescent idiopathic scoliosis (AIS).

Summary of Background Data. The rib hump prominence on the convex side is the major cosmetic concern among patients with AIS. Thoracoplasty combined with spinal fusion is a commonly used procedure in scoliosis. However, there are no studies regarding the effect of isolated thoracoplasty procedure on curve pattern in skeletally matured patients with AIS.

Methods. The study involved 7 skeletally matured female patients with AIS. The convex rib hump deformity was measured preoperatively using hump height and hump angle. We performed thoracoplasty without spinal fusion in patients with the Cobb angle less than 40° but with prominent hump deformity. Thoracoplasty was performed percutaneously using 1 or 2 transverse incisions along the rib hump, and apex portions of the deformed ribs were resected. The Cobb angle was measured before surgery, immediately after surgery, and at final follow-up visit. In all cases, clinical satisfaction was assessed using the Scoliosis Research Society Instrument (SRS-22 questionnaires) and trunk appearance perception scale before surgery and at final follow-up visit.

Results. The mean patient age was 20.24 years and an average of 4 ribs were resected. The mean preoperative hump height and hump angle of 38.14 mm and 14.14° improved to 11.70 mm and 11.42° respectively, after surgery (P = 0.018 and 0.042). Preoperative and the final follow-up mean Cobb angles were 35.43° and 45.00°, respectively (P = 0.028). On average, the mean thoracic curve progressed by 9.57°. Preoperative Scoliosis Research Society Instrument SRS-22 questionnaires and trunk appearance perception scale scores of 4.09 and 2.57 respectively improved to and 4.26 and 3.66 after surgery (P = 0.126 and 0.014).

Conclusion. Percutaneous thoracoplasty–only procedure gives significant rib humps correction and satisfactory clinical outcome. However, progression of the curve was observed after surgery. This suggests that the convex ribs function as a buttress for curve progression.

[TAMZTOM]

If Schroth seeks to reduce the rib hump, maybe this explains the lack of evidence of efficacy to date though my bet is the lack of compliance has prevented any true test of Schroth on a meaningful scale.

Lack of proper instruction will be a huge factor in the lack of testing, Sharon. I agree that compliance will also be a huge factor. Weiss-like buck making a 3rd. And remember, KATERINA SCHROTH'S METHOD is NOT the method that is purveyed by the practitioners of Weiss's "Nu Power Schroth." We may NEVER get a test of K Schroth's method from any of these clinics.

I wonder if PT-based methods that seek to reduce rib humps have the same effect of triggering progression.

The K Schroth method does seek to reduce the prominent convex ribs, what I call "the dorsal rib arch" (DRA). Tamzin no longer has one. Her thoracic curve is improved. What's the difference between this example of improved thoracic curve angle after K Schroth treatment and the surgical method that increased the curve angles?

1) straightening the buckled ribs INCREASES corrective derotation of thoracic vertebrae. The DRA is caused by ribs that belong at the side rotating to the back and/or bucking the back ribs.

2) surgically removing ribs leaves a gap AND rotation. Rotation is tied to lateral curvature. The curve increases.

If I were to hazard a guess, I'd suspect that the surgical correction of the DRA may evaporate over time...the DRA will return.

[Pooka1]

Yes but the rotation is due to the anterior overgrowth. If as in PT you use the ribs as a lever to try to untwist the spine, it might not simply resume a more normal, less curved, position because the anterior side is still longer than the other sides. I can't visualize where the vertebra go and in what position they go if you manually lever the ribs back towards the side from the back. Unless some space is made by hypokyphosing the back, it either can't work or will do something else with the vertebra.

This is a general question for all PT... how can it overcome the anterior overgrowth? The spine curves because of that in a space-filling way. If you have seen video of de-rotation procedures prior to fusion, those guys are employing a significant amount of leverage directly on each vertebra to make it come straight. But the front of the vertebra are still longer. That is why it can be hyokyphosing as far as I can tell.

I think braces work in part or in whole by forcing the ribs back to a more normal position which probably explains why they are hypokyphosing. Actually I have heard that the way they work is to hyperkyphose the back which is another way of saying they are making more room for the elongated fronts of the vertebrae to nevertheless still line up more correctly and not assume a space-filling arrangement.

[TAMZTOM]

Yes but the rotation is due to the anterior overgrowth.

I'm being pedantic here, but it's important: rotation MAY BE due to anterior overgrowth. For example, in a kid with thoracic hyper-kyphosis, there may not be ANY anterior overgrowth, but still rotation. However, to conform to your hypothetical, let's use Tamzin who is more hypo- than hyper and, theoretically, may have or have had AO.

If as in PT you use the ribs as a lever to try to untwist the spine, it might not simply resume a more normal, less curved, position because the anterior side is still longer than the other sides.

In the K Schroth method (as distinct from general "PT" which is often damaging), specifically "directional/rotational angular breathing", the ribs are indeed used as levers to derotate the spine. You then switch from the effect on the dorsal rib arch/prominent/buckled ribs to the effect on the spine? Again, to adhere to your hypothetical--and both effects are important--it is possible that the ribs could straighten out (as with Tamzin), but assumed AO presents a barrier to this rib straightening derotating the actual vertebrae. The ANTERIOR of each vertebrae is ALSO rotated, i.e., the anterior isn't at the geometric front, the front of the concerned vertebrae would be slightly rotated c/w. The force directed onto the vertebrae by the straightened DRA ribs has to go somewhere, affect something, as you rightly question. In Tamzin's case, given the flattening of her DRA, correction of a 40-42 degree thoracic curve to <25 and reduction of thoracic rotation from 15 to 4 degrees, the force derotates and corrects the lateral curve. So we needn't speculate. In the absence of Tamzin as an example, your theoretical questioning is excellent.

Furthermore, in the case of a hypo-kyphotic kid, that there is 'space' to the posterior, even the hypothetical existence of AO could in theory facilitate some restoration of a normal thoracic kyphosis.

I can't visualize where the vertebra go and in what position they go if you manually lever the ribs back towards the side from the back. Unless some space is made by hypokyphosing the back, it either can't work or will do something else with the vertebra.

Ach, I should have read this bit first. You've already reasoned that bit through.

This is a general question for all PT... how can it overcome the anterior overgrowth?

That is ALSO cutting edge questioning, Sharon. As Stokes et al explain, reversing the asymmetrical loading in growing vertebrae stops growth on the overgrown area of the growth plate and increases it on the retarded area. Asymmetrical growth can be reversed in growing spines. EDIT: I don't know how "all PT" can overcome anything! I thought we were talking about how Katernia Schroth's method overcomes anterior overgrowth. Talking about how "general PT" can overcome AO is like asking Usain Bolt to start doing 15 mile recovery jogs!

I think braces work in part or in whole by forcing the ribs back to a more normal position which probably explains why they are hypokyphosing. Actually I have heard that the way they work is to hyperkyphose ...

I've heard similar, Sharon. They ignore damage to the sagittal profile because they still implement theory from the middle ages. They do not force the ribs into normal position: e.g., restricted breathing in-brace keeps them contracted on the thoracic concave side, etc. Also depends on the brace. E.g., Cheneau do purport concern with the sagittal profile yet STILL result in cases with INCREASED rotation and compromised rib symmetry.

I like the way you're questioning all this...great to see.

[Pooka1]

I have always been perplexed by the comment I read in a paper saying pedicle screw constructs tended to be hypokyphosing as compared to say hooks. I could not understand what about pedicle screws was different from hooks and how can they be hypokyphosing if they bends the rods any way they like for the final balance. I now think the answer is that pedicle screws allow hyper-correction and unless they do osteotomies, the front of the spine is longer than the back and that will tend to decrease kyphosis when the vertebra are forced into alignment. My one kid was extremely rotated and had a 58* curve. After fusion she has no residual thoracic scoliosis, i.e., hyper-corrected. She also seems to be hypohyphotic. The other kid did not seem as rotated and she was only corrected to ~25* because she had a different type of T curve but she also seems a bit hypokyphotic.

If you look at some of these fusion videos, just the act of de-rotating the vertebrae seems to decrease the curve. That would make sense if the overgrowth causes the rotation which causes the lateral curve as a space-filling mechanism.

[TAMZTOM]

If you look at some of these fusion videos, just the act of de-rotating the vertebrae seems to decrease the curve. That would make sense if the overgrowth causes the rotation which causes the lateral curve as a space-filling mechanism.

As a factor of progression, yes, I've always thought the same. I believe one of my first posts in Tamzin's thread mentioned Katernia Schroth's thinking that there can be no sustainable lateral correction without derotation. I might have mentioned too that the Cheneau brace tried to counter the problem of earlier braces applying lateral force but messing up because they didn't address rotation. SpineCor research and 'theory' is in accord--they purport to tackle rotation before lateral curvature, as the latter would be pointless.

I say as a factor of progression rather than cause, though. The issue remains, 'What caused the overgrowth?' We're into speculation then (e.g., some genetic asymmetrical mistiming on different areas of the growth plates).

...unless they do osteotomies, the front of the spine is longer than the back and that will tend to decrease kyphosis when the vertebra are forced into alignment.

I've sat here for hours in the past mentally constructing a curve of tilted, rotated, wedged and/or ''anteriorly overgrown' vertebrae. Wish I had a model! (Stokes does good ones, I think.) I think you're spot on with that reasoning. Because of AO, even assuming a perfect surgical derotation and lateral correction, there just wouldn't be sufficient space posteriorly to create such a correction, or, if they could, it'd be at the expense of causing hyper-kyphosis to accommodate the AO. A compromise may be optimal, but hard to achieve surgically because of the myriad calculations required. Sawing off sections of posterior ribs to accommodate the AO sounds theoretically possible....but, as the study you cited shows, doesn't work!

My one kid was extremely rotated and had a 58* curve. After fusion she has no residual thoracic scoliosis, i.e., hyper-corrected. She also seems to be hypohyphotic. The other kid did not seem as rotated and she was only corrected to ~25* because she had a different type of T curve but she also seems a bit hypokyphotic.

Does that suggest surgeons accept the sagittal flattening as the price for lateral and rotation correction? I wonder if that is why surgery results in translated force to the un-fused parts of the spine. Were both your kids hypo-kyphotic before the surgery? (We actually had a dispute once with the orthotist crew in Sheffield: the head orthotist's assistant/trainee, looking at the computer with all it's measurements on the SpineCor software, suggested aloud that she wasn't really hypo-kyphotic. The head guy--you know who I mean--said "Of course she is!" Ignored his own software. The assistant was correct--she didn't have full, normal kyphosis, but it wasn't that flat.)

[Pooka1]

Sawing off sections of posterior ribs to accommodate the AO sounds theoretically possible....but, as the study you cited shows, doesn't work!

No it works for the reason it was done... improve cosmesis but it has a bad side effect of letting the curvature increase if not done is association with fusion. It is my understanding that these operations to flatten rib humps are successful in terms of producing a better looking back because the ribs do grow back less prominently. That's my understanding. It must be true because that op is supposedly very painful and they would never do it if it didn't work to remodel the ribs. In association with fusion, I imagine it would be a win if the curvature could not be hyper-corrected.

I wonder if that is why surgery results in translated force to the un-fused parts of the spine.

No this is only if the fusion extends past L3 (or above a certain level that compromises the unfused discs at the caudal end). I am not aware of any evidence that fusions that end above L3 cause any problem with discs below that. Our surgeon calls those "one-stop shopping" for surgery. There is a study that all patients about 20 years out had no special damage as could be associated with the fusion to their lower discs. Also, a cadaver study showed that age-controlled normals had similar minimal damage to the lowest disc (L5-S1) as people who were fused through the thorax as I recall. Even H rod patients fused just in the thoracic tend to be stable. T fusions might be "solved" as far as we know from this stand point. Other fusions are a different story.

Were both your kids hypo-kyphotic before the surgery?

I don't remember. Perhaps.

[TAMZTOM]

No it works for the reason it was done... improve cosmesis but it has a bad side effect of letting the curvature increase if not done is association with fusion.

Yes, you're correct--I forgot that it wasn't done with fusion. Seems a bit self-defeating though...saw off the ribs, increase the curve, which'll increase the rib bucking again...vicious cycle...then require fusion! Now that configuration would take some mathematical skills to solve.

No this is only if the fusion extends past L3 (or above a certain level that compromises the unfused discs at the caudal end).

Surgery isn't my suit. I thought the reason they are reluctant to go below L3 was to retain flexibility. If the spine is fused all the way down, that'd stop translated force causing another spinal curve because there is no unfused spine to curve. With unfused vertebrae, the sheer forces held by the rods must translate to the weaker areas, those being unfused vertebrae. I find this interesting, enlighten me.

There is a study that all patients about 20 years out had no special damage as could be associated with the fusion to their lower discs. Also, a cadaver study showed that age-controlled normals had similar minimal damage to the lowest disc (L5-S1) as people who were fused through the thorax as I recall.

I actually think I skimmed that one! That's good news for your kids then. Nice one.

[TAMZTOM]

It's this type of thing I've skimmed, Sharon. That's from 2002 though.

Long-Term Results From In Situ Fusion for Congenital Vertebral Deformity

Study Design. Retrospective review of long-term outcome of fusion in situ for congenital vertebral anomaly with particular emphasis on cosmesis and the incidence of reoperation.

Objective. Examination of the success rate of this procedure and of risk factors for failure.

Methods. Records of patients who were at least 15 years of age at last examination were reviewed retrospectively. Consideration was given to cosmetic outcome and to the incidence of reoperation.

Results. There were 43 patients in this category, 19 boys and 24 girls, who were at least 15 years of age when last seen. Reoperation had been performed in 11 cases (25.6%). The main finding was that, although the Cobb angle of the fused segment of spine remained constant after fusion, a curve sometimes developed in the whole spine, sometimes (but by no means always) centered on that fused segment. Cosmetic deformity continued to progress in a number of cases.

Conclusions. Localized fusion, whether posterior alone or anterior and posterior combined, was effective in preventing progression of the Cobb angle of the congenitally malformed area but did not control the overall deformity that developed or progressed with growth.

Current concepts of the pathomechanism of deformity do not adequately explain the observations, and a more biologic approach is suggested.



When we were 'advised' to have Tamzin fused, such considerations loomed large for such a young child.

[Pooka1]

Yes, you're correct--I forgot that it wasn't done with fusion. Seems a bit self-defeating though...saw off the ribs, increase the curve, which'll increase the rib bucking again...vicious cycle...then require fusion! Now that configuration would take some mathematical skills to solve.

No they were certainly blind-sided by that outcome. Nobody would have done that if they knew their curve would increase so much from the procedure. Those people may not have ever reached surgery range and now they might. It was a horrible mistake. It's very sad. Scoliosis is a cruel game.

Surgery isn't my suit. I thought the reason they are reluctant to go below L3 was to retain flexibility. If the spine is fused all the way down, that'd stop translated force causing another spinal curve because there is no unfused spine to curve. With unfused vertebrae, the sheer forces held by the rods must translate to the weaker areas, those being unfused vertebrae. I find this interesting, enlighten me.

They seem reluctant to go below L3 in KIDS to retain flexibility. They routinely go below L3 in a few kids where it seemingly can't be avoided and many adults. I don't know how long that strategy lasts but it hopefully lasts a long time. If it lasted forever then they would never go below L3 on anyone but that's not what we see. This is just my speculation. Only a surgeon can confirm or deny.

The forces associated with fusions that extend below L3 that don't go to pelvis do create forces that damage the unfused lower vertebra and apparently this often requires in an extension of the fusion. The time before that is required seems to vary wildly and maybe some never need it extended if they are careful. All I know is Boachie refers to these fusions below about L3 as "countdowns" for some reason. Only a surgeon can confirm or deny.

I am unaware of any evidence that fusion that end above L2 or so cause damage to lower vertebra above and beyond normal age and wear and tear. I think that result, coupled with the general stability of even H rod T fusions, is why our surgeon looked me in the face and in front of my daughter said this would likely be her only back surgery for scoliosis in her life. Since we don't have 70-80 years of data on T fusions, he can't KNOW/SHOW that but everything I have found points to it and there is no counter evidence I can find.

For this reason, it is a small mercy that the majority of surgical IS curves are AIS T curves. Hopefully most of these kids will only have one scoliosis surgery in their life.

[TAMZTOM]

For this reason, it is a small mercy that the majority of IS curves are AIS T curves. Hopefully most of these kids will only have one scoliosis surgery in their life.

Yeah. That would be good.

Incidentally, although it might cause a furore in here even mentioning the subject, I didn't mean to suggest that cosmetic reasons for the rib operation paper were not 100% legitimate reasons for treatment. For those that get the rib operation done for those reasons, good for them.

I must be tired...rambling now....nearly 2:00 a.m., hitting the sack.

Good night.

[Pooka1]

This is completely irrelevant to AIS curves and especially AIS T curves. This is about congenital scoliosis which involves specifically misshapen vertebra with various names (NOT anterior overgrowth) and who knows what else. They say there is something about the biology of congenital that must be causing this. There is no overlap between congenital and IS. The reason this was published is likely related to how congenital is different from AIS or they would have included AIS cases which are far more numerous. Congenital may not even have any rotational component as far as I know. Congenital is a very small proportion of scoliosis as far as I know. AIS is defined as having rotation due likely to the anterior overgrowth. This is why hysterical cases are not IS for example... they don't involve rotation as far as I know though they can be huge curves involving most of the spine.

The largest loss of correction I has seen documented in AIS in mainly in the axial plane, not the coronal or sagittal plane per one paper I recall. That would be rotation absent increased lateral curvature of decreased balance in the sagittal plane as I understand it.

This article is irrelevant to Tamzin as far as I know. C/SM is not associated with the malformations of congenital to my knowledge. I assume it behaves in the same manner as IS curves in terms of fusion other than the fact that curves can sometimes be instantly reduced just by draining the syrinx. There is no such instant reduction maneuver in IS. Many surgical articles are going to be irrelevant. You have to sort through it.

It's this type of thing I've skimmed, Sharon. That's from 2002 though.

Long-Term Results From In Situ Fusion for Congenital Vertebral Deformity

Study Design. Retrospective review of long-term outcome of fusion in situ for congenital vertebral anomaly with particular emphasis on cosmesis and the incidence of reoperation.

Objective. Examination of the success rate of this procedure and of risk factors for failure.

Methods. Records of patients who were at least 15 years of age at last examination were reviewed retrospectively. Consideration was given to cosmetic outcome and to the incidence of reoperation.

Results. There were 43 patients in this category, 19 boys and 24 girls, who were at least 15 years of age when last seen. Reoperation had been performed in 11 cases (25.6%). The main finding was that, although the Cobb angle of the fused segment of spine remained constant after fusion, a curve sometimes developed in the whole spine, sometimes (but by no means always) centered on that fused segment. Cosmetic deformity continued to progress in a number of cases.

Conclusions. Localized fusion, whether posterior alone or anterior and posterior combined, was effective in preventing progression of the Cobb angle of the congenitally malformed area but did not control the overall deformity that developed or progressed with growth.

Current concepts of the pathomechanism of deformity do not adequately explain the observations, and a more biologic approach is suggested.

I don't know how this article is relevant to Tamzin unless she has any of the list of congenital vertebral abnormalities. C/SM is not associated with these malformations to my knowledge. Rather it behaves like IS as far as I know EXCEPT the curves can be instantly reduced sometimes by draining the syrinx. There is no such instant reduction in AIS so it's different in that respect.


When we were 'advised' to have Tamzin fused, such considerations loomed large for such a young child.

[TAMZTOM]

This is completely irrelevant to AIS curves and especially AIS T curves.

"No", "No" and "completely irrelevant" are strong words, but I understand that you're not preparing an essay.

Yes, those were congenital cases, but research scientists who are "in the know" extrapolate. It is how surgical procedure makes advances, which for those going through the new experimental procedures since H rod fusions, we all hope are successful.

This seems more on point, although there will no doubt be differences between this group and others, e.g., your kids.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2078319/

"Twenty-six of 36 patients (72%) with Lenke type 3C adolescent idiopathic scoliosis treated with selective thoracic correction and fusion showed satisfactory coronal plane alignment 2 years after surgery. Ten of 36 patients (28%) showed coronal spinal decompensation of more than 2 cm, 2 years after surgery. Lumbar apical vertebral derotation of less than 40% on lumbar supine side-bending films provided the radiographic prediction of postoperative coronal spinal imbalance. We advise close scrutiny of the transverse plane in the lumbar supine side-bending film when planning surgical strategy."

The largest loss of correction I has seen documented in AIS in mainly in the axial plane, not the coronal or sagittal plane per one paper I recall.

Not according to this paper. That's another problem, so many papers, many ignoring the wood for the trees.

This article is irrelevant to Tamzin as far as I know. C/SM is not associated with the malformations of congenital to my knowledge.

As above, this paper on congenital scoliosis is relevant to all fusions. It is irrelevant to Tamzin in the sense that she won't be having fusion. And your repeated error in suggesting Tamzin has some unknown form of scoliosis called "C/SM scoliosis" is....repeated! Unless that is, the 3 spine surgeons and 2 neurosurgeons who we've consulted are all 'experts' who don't deserve the appellation 'expert', i.e., they're wrong and you're right. They are not prone to phrases such as "As far as I know". Now don't misinterpret me here, I'm not saying they deserve the appellation either...but you would call them experts and therefore should, for consistency, defer to their opinion.

This conversation is straying too far from what attracted me to it in the first place, i.e., your mental grappling with the problems of correcting rotation and lateral curvature, which I found insightful. I'm going back to work on that trail. If you come across any interesting stuff on the rotational issue, I'd be grateful if you pass it on.

[Pooka1]

This seems more on point, although there will no doubt be differences between this group and others, e.g., your kids.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2078319/

This article concerns only fusing part of a double major curve (two structural curves). It is irrelevant to other curve classes with single structural curves. It is also irrelevant to fusions that include the entire structural curve as in T fusions whereas they are deliberately leaving a structural curve unfused in this case. If it was relevant to other curve types then they wouldn't have excluded non double major curve types or double majors where both curves are fused. As I stated previously, other fusions besides T fusions are not necessarily "solved."

The hope is to avoid fusing the lumbar when there is a structural lumbar curve. Hence these types of studies are done to see if it is at all possible to spare the lumbar.

Surgical articles have sorted populations for a reason... the different curve types are known to behave differently because they have been shown to behave differently. Reading random articles will only confuse.

As a first cut, try only reading the C/SM surgical articles or just the JIS/AIS articles and ignore the rest as they will likely be irrelevant or at least have not been shown to be relevant to Tamzin.

[Pooka1]

Yes, those were congenital cases, but research scientists who are "in the know" extrapolate.

No research scientist extrapolates known apples to known oranges. These different types are known to be different in known respects.