Lukegao: by freem.ai...

2026-01-06T05:22:22Z

by freem.ai...

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{{DISPLAYTITLE:DISI شرح ونتائج إشعاعية}}

''This conversation was exported from ChatGPT''<ref>{{cite web|title=DISI شرح ونتائج إشعاعية|url=https://chatgpt.com/share/695bc248-c9bc-8008-82d2-be391b6b7b32|publisher=ChatGPT|access-date=2026-01-06}}</ref>

== gpt-5-2-thinking ==
=== User: radiographic findings is ===
radiographic findings is
consistent with dorsal intercalated segment
instability (DISI)ممكن تشرح وتنزل وتجيب صور كثيرة

=== Assistant: !https://www\.researchgate\.net/profile/Jonny\-Andersson/publication/319937516/figure/fig2/AS%3A540741919559680%4015059… ===
!https://www\.researchgate\.net/profile/Jonny\-Andersson/publication/319937516/figure/fig2/AS%3A540741919559680%401505934328078/Dorsal\-intercalated\-segment\-instability\-DISI\-with\-a\-scapholunate\-angle\-of\-approximately\_Q640\.jpg<ref>{{cite web|title=https://www\.researchgate\.net/profile/Jonny\-Andersson/publication/319937516/figure/fig2/AS%3A540741919559680%401505934328078/Dorsal\-intercalated\-segment\-instability\-DISI\-with\-a\-scapholunate\-angle\-of\-approximately\_Q640\.jpg|url=https://tse1.mm.bing.net/th/id/OIP.kZ9849t0tLROFWGb4fteDQAAAA?w=400&h=400&c=7&p=0|publisher=tse1.mm.bing.net|access-date=2026-01-06}}</ref>
!https://www\.medical\.theclinics\.com/cms/10\.1016/j\.mcna\.2014\.04\.003/asset/60d34e96\-d732\-48d4\-acd8\-915ab709ac0b/main\.assets/gr8\_lrg\.jpg<ref>{{cite web|title=https://www\.medical\.theclinics\.com/cms/10\.1016/j\.mcna\.2014\.04\.003/asset/60d34e96\-d732\-48d4\-acd8\-915ab709ac0b/main\.assets/gr8\_lrg\.jpg|url=https://tse3.mm.bing.net/th/id/OIP.e1CczQTVcLHPMVY03djDBAHaLE?w=474&h=474&c=7&p=0|publisher=tse3.mm.bing.net|access-date=2026-01-06}}</ref>
!https://data\.pacs\.de/sites/default/files/mirrorimages/media\.springernature\.com/full/springer\-static/image/art%253A10\.1007%252Fs13244\-014\-0337\-1/MediaObjects/13244\_2014\_337\_Fig3\_HTML\.gif<ref>{{cite web|title=https://data\.pacs\.de/sites/default/files/mirrorimages/media\.springernature\.com/full/springer\-static/image/art%253A10\.1007%252Fs13244\-014\-0337\-1/MediaObjects/13244\_2014\_337\_Fig3\_HTML\.gif|url=https://tse2.mm.bing.net/th/id/OIP.LwCzhhlMoWFXIEGhibY1cgAAAA?w=396&h=396&c=7&p=0|publisher=tse2.mm.bing.net|access-date=2026-01-06}}</ref>
!https://image\.slidesharecdn\.com/20150914stafflectureupperext\-150913143227\-lva1\-app6891/95/emergency\-radiology\-shoulder\-upper\-extremities\-70\-638\.jpg?cb=1442154947<ref>{{cite web|title=https://image\.slidesharecdn\.com/20150914stafflectureupperext\-150913143227\-lva1\-app6891/95/emergency\-radiology\-shoulder\-upper\-extremities\-70\-638\.jpg?cb=1442154947|url=https://tse3.mm.bing.net/th/id/OIP.p7cQCir92aY_l0BJJxAPXAHaFj?w=474&h=474&c=7&p=0|publisher=tse3.mm.bing.net|access-date=2026-01-06}}</ref>

يا محمد، لما يقول لك السؤال: “radiographic findings consistent with DISI” فهو غالبًا يريد منك “تلتقط” ميل الـ lunate للخلف (dorsiflexion) على lateral wrist radiograph وتثبت ذلك بالأرقام والزوايا الكلاسيكية.

==== DISI = Dorsal Intercalated Segment Instability ====
* “Intercalated segment” المقصود بها lunate (تُعتبر قطعة “وسطية” بين radius وcarpus).
* في DISI: الـ lunate تميل dorsally (extension/dorsiflexion) لأن التوازن الرباطي اتكسر غالبًا بسبب Scapholunate ligament injury → scaphoid يميل للـ flexion بينما lunate تُسحب للـ extension مع triquetrum/capitate.

المسبب الأشهر:
* Scapholunate ligament injury (خصوصًا بعد FOOSH) وهو المصدر الأكثر كلاسيكية لــ DISI. orthobullets.com<ref>{{cite web|title=orthobullets.com|url=https://www.orthobullets.com/hand/6041/scapholunate-ligament-injury-and-disi|publisher=orthobullets.com|access-date=2026-01-06}}</ref>

==== ### ====

لازم تكون الصورة true lateral (ده فخ امتحاني: لو الـ lateral غلط الزوايا كلها هتضرب).
# Scapholunate angle (SLA) مرتفع
* الطبيعي تقريبًا 30° إلى 60°.
* في DISI: غالبًا SLA أكبر من 70° (وهي عبارة امتحانية صريحة جدًا). orthobullets.com<ref>{{cite web|title=orthobullets.com|url=https://www.orthobullets.com/hand/6041/scapholunate-ligament-injury-and-disi|publisher=orthobullets.com|access-date=2026-01-06}}</ref>
# Radiolunate angle (RLA) مرتفع
* في DISI يحدث dorsal tilt of the lunate ويظهر كـ RLA أكبر من 10°. Radiopaedia<ref>{{cite web|title=Radiopaedia|url=https://radiopaedia.org/articles/dorsal-intercalated-segment-instability|publisher=radiopaedia.org|access-date=2026-01-06}}</ref>
# Capitolunate angle (أو Lunocapitate angle) مرتفع
* كثير من المراجع تذكر Capitolunate angle أكبر من 30° كداعم قوي للـ DISI. PMC<ref>{{cite web|title=PMC|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC4141341/|publisher=pmc.ncbi.nlm.nih.gov|access-date=2026-01-06}}</ref>

:

===== 1. Scapholunate gap widening =====
* “Terry Thomas sign” (زيادة المسافة بين scaphoid وlunate).
* أحيانًا تحتاج stress views مثل clenched fist view لإظهار الـ widening إذا كانت الإصابة ديناميكية. pubs.rsna.org<ref>{{cite web|title=pubs.rsna.org|url=https://pubs.rsna.org/doi/full/10.1148/rg.210123|publisher=pubs.rsna.org|access-date=2026-01-06}}</ref>
# Scaphoid ring sign
* نتيجة scaphoid flexion/rotary subluxation (حلقة/دائرة واضحة في scaphoid على PA).

==== - على lateral: - ارسم محور طويل لـ scaphoid ومحور لـ lunate → ده يعطيك Scapholunate angle. - محور radius مع محور lunate → Radiolunate angle. - محور capitate مع محور lunate → Capitolunate angle. الفكرة موجودة بصريًّا في الصور المرفقة في الأعلى (خصوصًا الرسوم التعليمية). ====

==== - ليست كل زيادة في SLA = DISI إذا كانت اللقطة ليست true lateral أو كان المعصم في وضع غير neutral. PMC<ref>{{cite web|title=PMC|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC8169173/|publisher=pmc.ncbi.nlm.nih.gov|access-date=2026-01-06}}</ref> ====
* DISI قد تكون dynamic: PA طبيعي تقريبًا لكن تظهر بالـ clenched fist أو ulnar deviation stress. pubs.rsna.org<ref>{{cite web|title=pubs.rsna.org|url=https://pubs.rsna.org/doi/full/10.1148/rg.210123|publisher=pubs.rsna.org|access-date=2026-01-06}}</ref>
* فرّق بين DISI و VISI: - DISI عادة مع Scapholunate ligament injury - VISI عادة مع Lunotriquetral ligament injury (وهنا lunate تميل volarly). PMC<ref>{{cite web|title=PMC|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC4141341/|publisher=pmc.ncbi.nlm.nih.gov|access-date=2026-01-06}}</ref>

==== الـ DISI المزمنة غالبًا تمشي في مسار SLAC wrist (Scapholunate Advanced Collapse)، ودي فكرة امتحانية شائعة جدًا: إصابة SL → DISI → تغيّرات تنكسية تدريجية. PMC<ref>{{cite web|title=PMC|url=https://pmc.ncbi.nlm.nih.gov/articles/PMC4141341/|publisher=pmc.ncbi.nlm.nih.gov|access-date=2026-01-06}}</ref> ====

==== - لو الأشعة مش واضحة والشك عالي: - اعمل stress views (clenched fist). pubs.rsna.org<ref>{{cite web|title=pubs.rsna.org|url=https://pubs.rsna.org/doi/full/10.1148/rg.210123|publisher=pubs.rsna.org|access-date=2026-01-06}}</ref> - وMRI / MR arthrogram لتقييم Scapholunate ligament خصوصًا في الإصابات الحادة/قبل الجراحة. pubs.rsna.org<ref>{{cite web|title=pubs.rsna.org|url=https://pubs.rsna.org/doi/full/10.1148/rg.210123|publisher=pubs.rsna.org|access-date=2026-01-06}}</ref> ====

إذا تحب، ابعتلي صورة السؤال/الأشعة اللي عندك (خصوصًا الـ lateral)، وأنا أمشي معك خطوة بخطوة: هل هي true lateral؟ وهل الزوايا داخلة في DISI ولا في perilunate/lunate dislocation (لأن دي برضه أسئلة شائعة وتتلخبط بسهولة).

== gpt-5-2 ==
=== User: ممكن تعيد بالانجليزي ===
ممكن تعيد بالانجليزي

=== Assistant: !https://prod\-images\-static\.radiopaedia\.org/images/30733038/986af30d0ca20e140b04cf5487c016\big\gallery\.jpeghttps:/… ===
!https://prod\-images\-static\.radiopaedia\.org/images/30733038/986af30d0ca20e140b04cf5487c016\_big\_gallery\.jpeg<ref>{{cite web|title=https://prod\-images\-static\.radiopaedia\.org/images/30733038/986af30d0ca20e140b04cf5487c016\_big\_gallery\.jpeg|url=https://prod-images-static.radiopaedia.org/images/30733038/986af30d0ca20e140b04cf5487c016_big_gallery.jpeg|publisher=prod-images-static.radiopaedia.org|access-date=2026-01-06}}</ref>
!https://www\.researchgate\.net/profile/Ahmed\-Elsaftawy/publication/256452003/figure/fig5/AS%3A314936254320644%401452098062635/n\-case\-of\-rotary\-subluxation\-of\-the\-scaphoid\-scapholunate\-angle\-60\-lunate\-capitate\_Q320\.jpg<ref>{{cite web|title=https://www\.researchgate\.net/profile/Ahmed\-Elsaftawy/publication/256452003/figure/fig5/AS%3A314936254320644%401452098062635/n\-case\-of\-rotary\-subluxation\-of\-the\-scaphoid\-scapholunate\-angle\-60\-lunate\-capitate\_Q320\.jpg|url=https://images.openai.com/thumbnails/url/m9sySnicu5mVUVJSUGylr5-al1xUWVCSmqJbkpRnoJdeXJJYkpmsl5yfq5-Zm5ieWmxfaAuUsXL0S7F0Tw4pdStxMk30KchLdyoOTPePCC5OS7YIyDQoznWKKvBxCynOyA0L9zcIjU_yygnzNEhKUSsGAJP0Jt4|publisher=images.openai.com|access-date=2026-01-06}}</ref>
!https://upload\.orthobullets\.com/topic/6041/images/gw275h550\.\.jpg<ref>{{cite web|title=https://upload\.orthobullets\.com/topic/6041/images/gw275h550\.\.jpg|url=https://upload.orthobullets.com/topic/6041/images/gw275h550..jpg|publisher=upload.orthobullets.com|access-date=2026-01-06}}</ref>
5
==== Radiographic Findings Consistent with DISI (Dorsal Intercalated Segment Instability) ====

===== 1) What does DISI mean? =====

DISI is a pattern of carpal instability in which the lunate tilts dorsally (extends) on the lateral wrist radiograph.
It occurs most commonly after Scapholunate ligament injury.
Mechanism in brief:
* Scaphoid loses its stabilizing link to the lunate → scaphoid collapses into flexion
* Lunate, pulled by the triquetrum and capitate, rotates into extension (dorsiflexion)

==== 2) Key Radiographic Findings (High-yield for exams) ====

===== A) Lateral view (the most important view) =====

: The diagnosis of DISI is primarily made on a true lateral wrist radiograph.
# Dorsal tilt of the lunate
* The lunate’s distal articular surface faces dorsally
* Often described as the lunate “cup” opening posteriorly
# Increased Scapholunate Angle (SLA)
* Normal: approximately 30°–60°
* DISI: typically greater than 70°
* This is the single most quoted numeric criterion in exams
# Increased Radiolunate Angle (RLA)
* Normal: near neutral
* DISI: greater than 10°, reflecting dorsal lunate tilt
# Increased Capitolunate (Lunocapitate) Angle
* Normal: less than 30°
* DISI: greater than 30°, indicating loss of collinearity between lunate and capitate

: Classic exam phrase:
: “DISI on lateral view is characterized by dorsal lunate tilt with an increased scapholunate angle, usually greater than 70 degrees.”

===== B) PA (posteroanterior) view – supportive findings =====

PA views help identify the cause, not the alignment itself.
# Scapholunate gap widening
* Increased distance between scaphoid and lunate
* Known as the “Terry Thomas sign”
# Scaphoid ring sign
* Seen due to scaphoid flexion and rotary subluxation
# Dynamic instability
* Early DISI may have a normal PA view
* Widening appears only on stress views such as: - Clenched fist view - Ulnar deviation stress view

==== 3) How to Measure (Practical Exam Technique) ====

On a true lateral radiograph:
* Draw the long axis of the scaphoid
* Draw the axis of the lunate → angle between them = Scapholunate angle
* Draw the radius axis and lunate axis → Radiolunate angle
* Draw the capitate axis and lunate axis → Capitolunate angle

If the lateral is not perfectly true, angles are unreliable (important pitfall).

==== 4) Common Pitfalls (Frequently Tested) ====
* False DISI can be diagnosed if the lateral view is rotated or not neutral
* DISI vs VISI: - DISI → dorsal lunate tilt → Scapholunate ligament injury - VISI → volar lunate tilt → Lunotriquetral ligament injury
* Early DISI can be dynamic, visible only with stress imaging

==== 5) Why DISI Matters Clinically (Exam Progression) ====

Untreated or chronic DISI commonly progresses to:
* SLAC wrist (Scapholunate Advanced Collapse)
* Predictable pattern of degenerative arthritis

This progression is a very common MCQ concept.

==== 6) If X-rays Are Inconclusive ====

Next diagnostic steps may include:
* Stress radiographs
* MRI or MR arthrogram to assess the Scapholunate ligament
* Wrist arthroscopy (gold standard in equivocal cases)

===== One-line exam summary =====

: DISI is diagnosed on a lateral wrist radiograph by dorsal tilting of the lunate with an increased scapholunate angle (usually greater than 70°), most commonly due to scapholunate ligament injury.

If you want, send me a specific wrist X-ray and I’ll walk you through it step-by-step exactly as in a viva or OSCE scenario.

== References ==
<references />

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Lukegao: by freem.ai...