Latest / Deep Dive Ortho — Orthopaedic Surgery, AI & Digital Health Podcast. / The BoTH Classification for Anterior Shoulder instability

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The BoTH Classification for Anterior Shoulder instability · Deep Dive Ortho — Orthopaedic Surgery, AI & Digital Health Podcast.

• 0:00
  Imagine you're a surgeon, you're looking at the
• 0:02
  scan, patient's shoulder keeps copping out anteriorly.
• 0:05
  You know you've got options, right? The Bankart,
• 0:07
  LaTarjet, maybe others. But choosing the right
• 0:10
  one for this patient, their specific anatomy,
• 0:13
  the exact injury, well, it feels less like picking
• 0:17
  a tool, more like a really tricky puzzle, high
• 0:20
  stakes. It absolutely is. It's a challenge orthopedic
• 0:23
  surgeons face all the time with traumatic anterior
• 0:26
  recurrent. shoulder instability. You know, the
• 0:29
  usual soft tissue fixes might not cut it if there's
• 0:32
  significant bone damage, but then bone procedures,
• 0:34
  they have their own set of issues. The big question
• 0:36
  has always been how do we map that out? How do
• 0:38
  we get a reliable guide to the best treatment
• 0:41
  for each person? And that is exactly what we're
• 0:44
  digging into today. We're looking at a systematic
• 0:46
  review from the Archives of Bone and Joint Surgery.
• 0:49
  You co -authored it, and it doesn't just summarize
• 0:51
  the evidence, it actually proposes a whole new
• 0:53
  classification system. The idea is to cut through
• 0:56
  that complexity, yeah, simplify those decisions
• 0:58
  for this specific type of instability. Yes, it's
• 1:01
  great to be able to talk about this. The goal
• 1:03
  really was to bring together the current evidence
• 1:05
  and offer a more structured evidence -based way
• 1:08
  forward for both surgeons and their patients.
• 1:10
  Okay, so before we jump into the nuts and bolts
• 1:12
  of this new system, let's just stay with that
• 1:15
  complexity for a second. Why weren't the old
• 1:17
  ways quite working? You know, just relying on
• 1:21
  surgeon preference or existing classifications,
• 1:23
  what crucial things weren't really being looked
• 1:25
  at together? Well, the core problem is that success
• 1:29
  Preventing it from happening again. It hinges
• 1:31
  on several things all working together not just
• 1:34
  one or two factors You can fix the torn tissue
• 1:36
  sure, but if there's say Quite a bit of bone
• 1:39
  loss on the socket the glenoid Or if that dent
• 1:42
  on the ball part of the arm bone the hill sacks
• 1:45
  lesion catches when they move The shoulder can
• 1:48
  still pop out right and equally if the patient's
• 1:51
  soft tissues are just well poor quality from
• 1:54
  repeated dislocations Even a technically good
• 1:56
  repair might not hold Older systems tended to
• 1:59
  focus on maybe just the bone loss or just the
• 2:02
  tissue or maybe the hill sacks. They didn't really
• 2:04
  combine the assessment of all three effectively.
• 2:08
  The bone loss, the quality of the soft tissue
• 2:10
  that's left, and the specific nature of that
• 2:13
  hill sacks lesion is engaging or not. That wasn't
• 2:17
  really integrated into one single pathway. So
• 2:19
  surgeons were sort of... mentally juggling these
• 2:21
  variables. Leading to less consistency, I imagine.
• 2:23
  It sounds like those key puzzle pieces weren't
• 2:25
  being fitted together properly. Exactly. And
• 2:28
  that's precisely the gap this new both classification
• 2:31
  system aims to fill. It gives a structured method
• 2:34
  to assess these three really critical injury
• 2:36
  features and then map them to the surgical strategies
• 2:40
  that the evidence supports most strongly. Both.
• 2:43
  OK, let's break that down. B -O -T -H. What's
• 2:46
  it stand for and how does it bring order to this?
• 2:48
  So both stands for bone loss, tissue quality,
• 2:51
  and hill sacs lesion. The whole idea is that
• 2:53
  by accurately classifying the severity and the
• 2:55
  type of damage in these three areas, you can
• 2:57
  seriously narrow down the surgical choices. You
• 3:00
  can pinpoint the procedure, or maybe combination
• 3:02
  of procedures, that's most likely to give that
• 3:05
  patient long -term stability. Right, getting
• 3:07
  really specific about the injury pattern. Okay.
• 3:09
  Okay, let's start with MO bone loss. How do you
• 3:12
  look at that? What are the key differences the
• 3:13
  system makes? Bone loss refers to how much bone
• 3:18
  has been chipped away or worn down from the front
• 3:20
  of the glen or at the socket. We usually measure
• 3:22
  it from CT scans, look at it as a percentage
• 3:25
  of the socket surface. And the research, which
• 3:29
  lines up with what's already known, points to
• 3:31
  a key threshold often around 15 to 20 percent
• 3:34
  damage below that level. We call that subcritical
• 3:37
  bone loss. More than that is critical bone loss.
• 3:40
  And that distinction is really fundamental because
• 3:43
  critical bone loss usually means you have to
• 3:44
  add bone back to make the socket stable again.
• 3:47
  Subcritical loss. Well, you might manage with
• 3:50
  just soft tissue work, but it depends on the
• 3:51
  other factors. OK, so bow is subcritical or critical
• 3:54
  around that 15, 20 percent mark. Got it. Yeah.
• 3:57
  Next up to tissue quality. What's being assessed
• 3:59
  there? Peace looks at the quality of the labrum
• 4:01
  and the capsule at the front of the shoulder.
• 4:03
  They're the main soft tissue stabilizers. like
• 4:06
  a bumper and a strong hammock holding the ball.
• 4:08
  If they've been torn repeatedly or they're stretched
• 4:10
  out or maybe just naturally a bit lax, well,
• 4:13
  they can't stabilize things properly. So we classify
• 4:16
  this quite simply as good or poor. Good or poor,
• 4:20
  okay. Good quality you typically see after maybe
• 4:23
  a first or second dislocation, someone without
• 4:25
  that underlying looseness. Poor quality is more
• 4:28
  common after lots of dislocations. The tissue
• 4:30
  is just degraded, worn out, can't really do its
• 4:34
  job as a primary stabilizer anymore. So tease
• 4:36
  about how resilient those soft tissues are still
• 4:39
  up to the job, or basically worn out. Makes sense.
• 4:42
  And finally, H. hilsax lesion. You mentioned
• 4:44
  it's a dent, but the classification isn't just
• 4:47
  if it's there. It's about this. on track versus
• 4:49
  off track thing. Precisely. A hill -sax lesion,
• 4:52
  that's a dent on the back of the humeral head,
• 4:53
  the ball. It happens when it hits the glenoid
• 4:56
  rim during a dislocation. Right. But the really
• 4:58
  critical thing, and this builds on some very
• 5:00
  important work in the field, is whether that
• 5:02
  dent engages or catches on the front edge of
• 5:05
  the socket when you move your arm into certain
• 5:07
  positions like reaching up and out. Ah, I see.
• 5:09
  If it doesn't catch, doesn't lever the joint
• 5:11
  out, we call it noontrack. But if it does engage,
• 5:14
  acts like a sort of cam forcing the joint out,
• 5:17
  then it's off -track. And an off -track hillsax
• 5:19
  is a major driver of instability. It needs specific
• 5:22
  treatment, really regardless of the other factors.
• 5:24
  So the both system puts these three things together.
• 5:27
  Bone loss, subcritical, tissue quality, good
• 5:30
  poor. and Hill Sachs, Noontrac off -track. That
• 5:34
  defines the specific injury patterns. And this
• 5:36
  is the map you were talking about guiding the
• 5:38
  treatment. Let's piece it together. What does
• 5:40
  both type 1 look like? Type 1 is probably the
• 5:44
  most straightforward scenario. You've got subcritical
• 5:46
  bone loss less than that 15 -20%. You've got
• 5:49
  good tissue quality. And the Hill Sachs lesion
• 5:51
  is Noontrac. So the main issue here is the initial
• 5:54
  soft tissue tear from the dislocation. But the
• 5:57
  basic structure and tissue strengths are still
• 5:59
  pretty sound. And based on your review, what's
• 6:01
  the recommended path for Type 1? For Type 1,
• 6:04
  the evidence strongly supports a standard bankart
• 6:06
  repair. This procedure just anatomically fixes
• 6:09
  that torn labrum, tightens up the capsule, essentially
• 6:12
  restores the soft tissue bumper. Since the bone's
• 6:15
  okay, tissues are good, HillSex isn't causing
• 6:17
  trouble, just fixing the soft tissue damage is
• 6:20
  often enough to get stability back. Okay, that
• 6:22
  makes sense. Fix the main problem if the foundations
• 6:24
  are solid. Now, Type 1 plus seri... That little
• 6:28
  plus suggests something extra is going on. Exactly
• 6:31
  right. Type 1 Plus still has that subcritical
• 6:33
  bone loss and the good tissue quality, just like
• 6:35
  Type 1. But the key difference is an off -track
• 6:38
  hill -sax lesion. So you still have good tissues,
• 6:41
  not much bone loss on the socket, but that dent
• 6:44
  on the humerus is actively making it unstable
• 6:46
  because it's catching on the glenoid edge. So
• 6:49
  you need to fix the tissue and deal with that
• 6:51
  engaging hill -sax. What does the system suggest
• 6:53
  then? For type 1 plus Harry, the recommendation
• 6:56
  is a bankart repair plus a remplasage. Remplasage
• 7:00
  is a technique where we take the infraspinatus
• 7:02
  tendon from the back of the shoulder and stitch
• 7:04
  it into that hillsack's dent. It effectively
• 7:07
  fills the hole, stops it from catching or engaging
• 7:10
  on the glenoid when the arm moves, so it gets
• 7:13
  rid of that specific way it was re -dislocating.
• 7:15
  Fascinating. So remplasage deals specifically
• 7:17
  with that off -track hillsacks when bone loss
• 7:20
  and tissues are otherwise alright. OK, let's
• 7:24
  move to type 2. How does the picture change now?
• 7:27
  With type 2, we're still looking at subcritical
• 7:28
  bone loss and still in noon -track hill sacks.
• 7:31
  But, and this is the crucial difference, we now
• 7:34
  have poor tissue quality. The soft tissues, the
• 7:36
  labrum and capsule, they just aren't reliable
• 7:39
  stabilizers anymore. Maybe stretched, frayed
• 7:42
  from previous dislocations. So even if the bone's
• 7:44
  mostly fine and the hill sacks isn't catching,
• 7:46
  if the tissue itself is compromised, a standard
• 7:50
  bank heart probably won't hold up. That's exactly
• 7:52
  it. Trying to repair poor quality tissue with
• 7:54
  a standard bankard? Well, the results are less
• 7:57
  predictable. So for type two, the research points
• 7:59
  towards dynamic interior stabilization or DAS.
• 8:03
  Yes. This technique uses the long head of the
• 8:06
  biceps tendon. It's redirected to the front of
• 8:09
  the glenoid and it acts like a dynamic sling
• 8:11
  or a hammock. The biomechanical evidence really
• 8:15
  supports DAS in this specific situation. It gives
• 8:18
  that vital dynamic support that the degraded
• 8:21
  native tissues just can't provide anymore. It
• 8:24
  compensates for the poor tissue even when bone
• 8:26
  loss isn't critical. That makes a lot of sense,
• 8:29
  bringing in a reinforcement, a dynamic one, when
• 8:32
  the original tissues are unreliable. And following
• 8:34
  the pattern, type 2 plus must be subcritical
• 8:37
  bone loss, poor tissue, and the off -track hill
• 8:39
  sacks. You've got it perfectly. Type 2 plus brings
• 8:42
  together subcritical bone loss, poor tissue quality,
• 8:45
  and an off -track hill sacks lesion. Which would
• 8:47
  logically need the DAS for the poor tissue and
• 8:49
  the remposage for the hill sacks. Precisely the
• 8:51
  recommendation, DAS plus remposage. You need
• 8:54
  both parts to tackle that specific combination
• 8:56
  of problems. Okay, right, so that covers all
• 8:59
  the situations where bone loss is subcritical.
• 9:01
  You layer in DAS for poor tissue, or remplassage
• 9:05
  for an off -track hillsax, or both if needed.
• 9:07
  Now, things get more complex when we cross that
• 9:11
  15 -20 % line into critical bone loss. What about
• 9:14
  both type 3? Well, once you have critical bone
• 9:16
  loss, just fixing soft tissue onto a deficient
• 9:19
  socket isn't really enough. You've got to rebuild
• 9:21
  the bony structure. So type 3 is defined as critical
• 9:24
  bone loss over 15 -20%, but importantly good
• 9:27
  tissue quality. and a Noontrag Hillsax. The bone
• 9:30
  needs sorting, but the soft tissues are still
• 9:32
  okay. And the suggested procedure for type 3.
• 9:35
  For type 3, the evidence points towards free
• 9:37
  glenoid bone grafting, or FGBG. This involves
• 9:40
  taking a piece of bone from somewhere else, often
• 9:42
  the patient's hip bone, the iliac crest, or sometimes
• 9:45
  another bit of the shoulder, like the end of
• 9:46
  the collarbone, and grafting it onto the front
• 9:48
  of the glenoid, rebuilding the socket to its
• 9:50
  proper shape. FGBG. So basically creating a new
• 9:54
  anatomical bony stop. The research mentioned
• 9:56
  this might be preferred over Letarjet sometimes.
• 9:59
  Yes. The review notes that FGBG gives you an
• 10:01
  anatomical reconstruction, which can be an advantage.
• 10:04
  For type 3, where the tissue quality is still
• 10:06
  good and you don't necessarily need that dynamic
• 10:09
  sling effect you get with Letarjet, FGBG is presented
• 10:12
  as a really good anatomical option. It restores
• 10:15
  the bone and potentially has a different risk
• 10:17
  profile compared to Letarjet in just this specific
• 10:20
  context. Interesting. So FGBG for critical bone
• 10:23
  loss if the tissues are good. Following the pattern,
• 10:26
  type 3 plus must be critical bone loss, good
• 10:29
  tissue, and the off -track hill sacs. Exactly.
• 10:31
  Critical bone loss, good tissue quality, and
• 10:33
  an off -track hill sacs. The treatment logically
• 10:35
  follows. FGBG plus room placage. Rebuild the
• 10:39
  socket anatomically with the graft and neutralize
• 10:41
  that engaging hill sacs lesion. All right. Nearly
• 10:44
  there. Two types left. Type 4. Critical bone
• 10:46
  loss again. What about the tissue and hill sacks
• 10:48
  here? Type 4 is where you have the double whammy.
• 10:51
  Yeah. Critical bone loss and poor tissue quality,
• 10:53
  but the hill sacks lesion is noontrack. So both
• 10:56
  the bone structure and the soft tissue restraints
• 10:58
  are significantly compromised. Ugh. Critical
• 11:01
  bone loss and poor tissue. This sounds like classic
• 11:04
  territory for the Letarjet procedure, doesn't
• 11:06
  it? Precisely. Letarjet is the recommended treatment
• 11:08
  for type 4. This procedure, as you know, transfers
• 11:12
  the coracoid process, that bony outcrop, from
• 11:14
  the shoulder blade along with its attached muscles,
• 11:17
  the conjoined tendon, to the front of the glenoid.
• 11:19
  The bone bit addresses the critical bone loss,
• 11:23
  rebuilds the socket depth, but crucially, that
• 11:25
  transferred tendon acts as a powerful dynamic
• 11:28
  stabilizer, provides that vital sling effect.
• 11:30
  And that's particularly helpful when the patient's
• 11:32
  own soft tissues are poor quality and can't provide
• 11:35
  enough stability on their own. So Letarjet tackles
• 11:38
  both issues, the missing bone and the poor tissue,
• 11:40
  even though it's not strictly anatomical. The
• 11:43
  research did mention its risks, though. It did.
• 11:46
  The systematic review acknowledges Letarjet.
• 11:49
  while highly effective, is definitely more complex
• 11:52
  than a straightforward bank card. It has a known
• 11:54
  learning curve, and, as the evidence we reviewed
• 11:57
  showed, it can have complications like infection
• 12:00
  or nerve issues, potentially at higher rates
• 12:02
  than, say, FGBG or bank card, when used in the
• 12:05
  right situations. Which, again, just highlights
• 12:07
  why matching the procedure to the specific injury
• 12:10
  pattern, like both aims to do, is so important.
• 12:13
  Understanding the trade -offs. Okay, and finally,
• 12:15
  type 4 plus 0. The most complex picture. Type
• 12:18
  4 plus is critical bone loss, poor tissue quality,
• 12:21
  and an off -track hill -sax lesion. You've got
• 12:23
  significant bone loss, unreliable soft tissues,
• 12:26
  and that engaging dent on the humeral head. The
• 12:28
  full house, if you like. Lethargia, again, I
• 12:30
  assume, because of the bone loss and poor tissue.
• 12:31
  What about the hill -sax in this case? It's lethargia,
• 12:34
  yes, often. Even though the Tarjet provides significant
• 12:38
  stability, especially with that sling effect,
• 12:41
  if you have a really large off -track hill sacks
• 12:44
  or very severe glenoid bone loss, adding Remplasage
• 12:48
  can give that extra bit of security. It neutralizes
• 12:51
  that specific engaging mechanism, even on top
• 12:54
  of the lethargic, kind of a belt and braces approach
• 12:57
  for the toughest cases. Wow. Okay, walking through
• 13:00
  those types really clarifies the logic behind
• 13:03
  each treatment choice when you look at all three
• 13:05
  factors together. Just to quickly recap the roles
• 13:07
  of those, let's call them advanced techniques,
• 13:10
  remplasage seems to be the go -to for that engaging
• 13:12
  the off -track hill sex, no matter the bone or
• 13:15
  tissue situation. Generally, yes, it addresses
• 13:17
  that specific mechanical issue. And DAS comes
• 13:20
  in to give that crucial dynamic support when
• 13:22
  bone loss is subcritical but the soft tissues
• 13:24
  are poor. Correct. It compensates for the poor
• 13:26
  native tissue. And FGBG is presented as the anatomical
• 13:30
  bone block choice for critical bone loss, especially
• 13:33
  if the native soft tissues are still good and
• 13:35
  you want that anatomical restoration. That's
• 13:37
  an excellent summary of their specific roles
• 13:39
  in this framework. The real strength of both
• 13:42
  is precisely that guiding the surgeon to pick
• 13:44
  which tool or combination of tools fix the exact
• 13:48
  mix of bone damage, tissue integrity, and humeral
• 13:51
  head issues. It feels like it takes something
• 13:53
  that was maybe a bit subjective and gives it
• 13:55
  an objective evidence -based structure, a roadmap
• 13:58
  really. It aims to simplify things for surgeons
• 14:01
  and hopefully lead to a more personalized approach
• 14:04
  for patients matching the fix directly to their
• 14:06
  injury, which surely has to mean better outcomes,
• 14:10
  fewer redislocations down the line. That's certainly
• 14:12
  the intention. By standardizing how we assess
• 14:15
  these injuries and linking that assessment directly
• 14:17
  to procedures backed by the best available evidence,
• 14:21
  the hope is definitely to improve consistency
• 14:23
  and optimize outcomes for patients. Our systematic
• 14:26
  review supported these distinctions, too, noting
• 14:28
  things like, yes, letharget might have lower
• 14:31
  recurrence for some complex injuries compared
• 14:33
  to bankart, but also carries a higher infection
• 14:35
  risk. It reinforces that need for careful patient
• 14:38
  selection based on the specific injury pattern.
• 14:41
  And biomechanical studies also back up the reasoning.
• 14:44
  for using techniques like DAS and those specific
• 14:47
  poor tissue scenarios. So the core message seems
• 14:50
  clear. Treating traumatic anterior recurrent
• 14:52
  shoulder instability isn't one size fits all.
• 14:56
  But this both classification offers a really
• 14:58
  powerful framework. By carefully looking at the
• 15:01
  bone loss, the tissue quality, and the hill sacs
• 15:04
  lesion, surgeons can navigate the options bank
• 15:06
  heart, DAS, FGBG, Letarjet, often adding RIMP
• 15:11
  -Lassage to hopefully deliver a surgical solution
• 15:14
  tailored precisely to your unique injury pattern.
• 15:17
  It provides that clear path through the puzzle.
• 15:19
  It helps turn a complex clinical judgment into
• 15:21
  a more structured, evidence -informed process.
• 15:25
  And that leaves us with a final thought to ponder.
• 15:27
  How does creating this kind of detailed classification
• 15:30
  system, one that meticulously breaks down a complex
• 15:33
  problem into its key parts to guide action mirror
• 15:36
  the way we perhaps need to tackle complex decisions
• 15:38
  in other professional fields, especially when
• 15:40
  dealing with lots of variables and significant
• 15:42
  potential risks. It's a very relevant question,
• 15:45
  well beyond the operating theater. Indeed. If
• 15:48
  you found this deep dive useful, please do think
• 15:50
  about rating and sharing it. It really helps
• 15:53
  other people find these discussions. Thank you
• 15:56
  for the opportunity to explore this research
• 15:58
  today.