8
Hand, Wrist, and Forearm
Surgical Anatomy: Key Points
Hand Anatomy
| 1. | Where are the two ossification centers of the second through fifth metacarpals located? | 1. | Body (ossifies at 8 weeks) Neck (ossifies at 3 years) |
| 2. | How is the first metacarpal ossification center unique? | 2. | Ossification center at the base (like phalanx) |
| 3. | What two intrinsic muscles are responsible for flexion at the metacarpophalangeal (MCP) joints? | 3. | Interossei (IO) Lumbricals |
| 4. | What two muscles are responsible for flexion of the proximal interphalangeal (PIP) joints? | 4. | Flexor digitorum superficialis (FDS) Flexor digitorum profundus (FDP) |
| 5. | What muscle is responsible for flexion of the distal interphalangeal (DIP) joints? | 5. | FDP |
| 6. | What intrinsic muscles are innervated by the ulnar nerve? | 6. | Third and fourth lumbricals All volar interosseous muscles All dorsal interosseous muscles Adductor pollicis Deep head flexor pollicis brevis All four hypothenar muscles |
| 7. | What structures are responsible for extension at the MCP joints? | 7. | The extensor digitorum communis (EDC) |
| 8. | What structures are responsible for extension at the PIP joints? | 8. | Intrinsic muscles (through the lateral bands) Central slip of the EDC |
| 9. | What structures are responsible for extension at the DIP joints? | 9. | Terminal tendon of the EDC |
| 10. | What structures span between extensor tendons? | 10. | Juncturae tendinum |
| 11. | What is the origin of the opponens digit quinti? What is the insertion? What is the function? | 11. | Origin: hook of hamate Insertion: ulnar fifth metacarpal Function: adduct and flex the fifth metacarpal |
| 12. | How many dorsal interossei are there? | 12. | Four |
| 13. | On which digits are they located? | 13. | Radial aspect of index finger Radial and ulnar aspects of long finger Ulnar aspect of ring finger |
| 14. | What dorsal interosseous muscle does not have two muscle bellies? | 14. | Third dorsal IO |
| 15. | Do dorsal interossei abduct or adduct? | 15. | Abduct |
| 16. | How many palmar interossei are there? | 16. | Three |
| 17. | On which digits are they located? | 17. | Situated toward the midline on: Index finger-ulnar aspect Ring finger-radial aspect Small finger-radial aspect |
Lumbricals
| 18. | How many lumbricals are there? | 18. | Four |
| 19. | Origin? | 19. | FDP tendon |
| 20. | Insertion? | 20. | Radial lateral band |
| 21. | Innervation? | 21. | Ulnar nerve (two): bipennate lumbricals Median nerve (two): unipennate lumbricals |
| 22. | What is the relationship of the lumbricals to the transverse intermetacarpal (IM) ligaments? | 22. | Lumbricals pass volar to transverse IM ligament |
| 23. | In what hand deformity do lumbricals play a key role? | 23. | Lumbrical plus hand |
| 24. | What is the classic symptomatic description of this syndrome? | 24. | Paradoxical extension of the PIP with actual digital flexion |
| 25. | Why does paradoxical extension occur? | 25. | A transected FDP tendon retracts with active flexion Lumbrical is drawn proximally by retracting FDP Lumbrical pulls on the lateral band PIP extension results |
| 26. | What is the preferred treatment of chronic lumbrical plus hand? | 26. | Lumbrical release from FDP origin |
| 27. | What two structures form the lateral bands? | 27. | (Dorsal/volar) interosseous muscles Lumbricals (attached to the radial lateral bands) |
Relationships Between Structures in the Hand
| 28. | Is Cleland’s ligament dorsal or volar relative to Grayson’s? | 28. | Cleland: dorsal Grayson: volar |
| 29. | What is the relationship of the digital nerves to the digital arteries in the digit? | 29. | Nerve volar to artery in digit |
| 30. | What is the relationship of the digital nerves to the digital arteries in the palm? | 30. | Nerve dorsal to artery in palm |
Deep Arch of the Hand
| 31. | What artery provides the principal supply to the deep palmar arch? | 31. | Radial |
| 32. | Is the deep arch relatively proximal or distal to the superficial palmar arch? | 32. | Proximal |
| 33. | The deep arch is codominant with the superficial arch in what percentage of patients? | 33. | 21.5% |
| 34. | Between which two bones does the radial artery course to pass from the dorsal to the volar hand? | 34. | Between the base of the first and second metacarpals |
| 35. | The deep arch is complete in what percentage of patients? | 35. | 98.5% |
| 36. | The superficial arch is complete in what percentage of patients? | 36. | 78.5% |
Wrist Anatomy
| 37. | What carpal bone is the first to ossify? | 37. | Capitate |
| 38. | What are the next to ossify (in order)? | 38. | Hamate Triquetrum Lunate Scaphoid |
| 39. | What is the last carpal bone to ossify? | 39. | Pisiform |
| 40. | At what age? | 40. | Around 9 years |
| 41. | At which articulation does the majority of wrist flexion occur? | 41. | Radiocarpal joint (two thirds) |
| 42. | Where does the remainder of wrist flexion occur? | 42. | Intercarpal joint (one third) |
| 43. | Are the radiocarpal ligaments stronger volarly or dorsally? | 43. | Volarly |
| 44. | Are the scapholunate ligaments stronger volarly or dorsally? | 44. | Dorsally |
| 45. | Are the lunotriquetral ligaments stronger volarly or dorsally? | 45. | Volarly |
| 46. | What is the importance of the radioscapholunate (RSL) ligament (ligament of Testut)? | 46. | Serves as a vascular conduit supplying the SL ligament |
| 47. | What are the contents of each of the six compartments of the wrist? | 47. | First: APL, EPB (abductor pollicis longus, extensor pollicis brevis) Second: ECRL, ECRB (extensor carpi radialis longus and brevis) Third: EPL (extensor pollicis longus) Fourth: EDC, EIP (extensor digitorum communis, extensor indicis proprius) Fifth: EDM (extensor digiti minimi) Sixth: ECU (extensor carpi ulnaris) |
| 48. | What structure in the first compartment may have multiple slips (important if release needed)? | 48. | APL |
| 49. | In which compartment is the PIN (posterior interosseous nerve) located? | 49. | Floor of the fourth compartment |
Relationships Between Structures at the Wrist
| 50. | What is the relationship between the EIP and EDC of the index finger? | 50. | EIP is ulnar to EDC of the index finger |
| 51. | What is the relationship between the EDM and EDC of the small finger? | 51. | EDM is ulnar to EDC of the small finger |
| 52. | What is the relationship between EPL and EPB? | 52. | EPL ulnar to EPB |
| 53. | What is the relationship between ECRB and ECRL? | 53. | ECRB is ulnar to ECRL |
Forearm Anatomy
| 54. | What are the compartments of the forearm? | 54. | Volar Dorsal Mobile wad |
| 55. | With a compartment syndrome, the greatest degree of injury occurs where? | 55. | Deep |
Vascular Supply
| 56. | The brachial artery contributes to what distal arteries? | 56. | Radial and ulnar arteries |
| 57. | What artery (radial/ulnar) is the origin of the interosseous arteries? | 57. | Ulnar artery |
| 58. | What percentage of the population has a persistent median artery? | 58. | 10% |
Surgical Approaches to the Radius
| 59. | The proximal volar Henry approach is between what two muscle groups? | 59. | PT (pronator teres) BR (brachioradialis) |
| 60. | The distal volar Henry approach is between what two muscle groups? | 60. | BR Flexor carpi radialis (FCR) |
| 61. | The proximal dorsal approach is between what muscle groups? | 61. | EDC ECRB |
| 62. | The distal dorsal approach is between what muscle groups? | 62. | ECRB EPL |
Flexor and Extensor Tendon Anatomy, Injury, and Repair
Acute Flexor Tendon Injury
Relevant Anatomy
| 63. | Flexor tendon blood supply is via vincula entering (dorsally or volarly? | 63. | Dorsally |
| 64. | By what methods are tendons nourished? | 64. | Synovial nutrition Longitudinal intertendinous vessels Vessel branches in vincula |
| 65. | This process of synovial nutrition is also known as what? | 65. | Imbibition |
| 66. | The two terminal slips of FDS join at what location? | 66. | Camper’s chiasm |
| 67. | What structure passes over this point? | 67. | FDP |
| 68. | What is the relationship of the FDP to the FDS at all locations except at Camper’s chiasm? | 68. | FDP deep to FDS in the palm and digits except at Camper’s chiasm |
| 69. | What pulleys are considered critical to normal finger function? Why? | 69. | A2 A4 These are the most critical for preventing flexor tendon bow-stringing |
| 70. | What pulleys are located over the joints of the digits? | 70. | A1 A3 A5 |
| 71. | When exposing the PIP volar plate, what pulleys can be sacrificed safely? | 71. | Distal part of C1 Entire A3 Proximal part of C2 |
| 72. | What are the zones of flexor tendon injury? | 72. | I: distal to FDS insertion (FDP only) II: from A1 pulley (both FDP and FDS, “no-man’s land”) to FDS insertion III: proximal to A1 pulley distal to carpal tunnel IV: within carpal tunnel V: wrist/forearm |
Management of Acute Injury
| 73. | What is the treatment for flexor tendon injury involving <25% tendon diameter? | 73. | Trim torn fragment |
| 74. | What is the treatment for injury involving 25 to 50% of tendon diameter? | 74. | Epitenon repair |
| 75. | What is the treatment for injury involving over 50% of tendon diameter? | 75. | Core and epitenon repair |
| 76. | Clinically obvious bow-stringing suggests what associated injuries? | 76. | Flexor tendon sheath disruption likely involving A2 and A4 pulleys |
| 77. | What are the three flexor tendon healing phases, and characteristics of each? | 77. | Inflammatory (days, 0 to 5): minimal strength, suture imparts tendon repair strength Fibroblastic (day 5 to 3–6 weeks): increasing strength, fibroblasts proliferate Remodeling (>day 28): collagen cross-linking |
| 78. | At which time point is the repair weakest? | 78. | Days 6 to 12 (end of inflammatory phase) |
| 79. | The majority of the repaired tendon strength returns by what time? | 79. | 28 days (end of fibroblastic phase) |
| 80. | When is the maximum strength of the repair achieved? | 80. | 6 months (end of remodeling phase) |
| 81. | What is the most important factor in determining strength of repair? | 81. | Number of crossing core suture strands |
| 82. | The addition of epitendinous suture increases repair strength by how much? | 82. | 50% |
| 83. | Is there a reported advantage to pulley release at the time of flexor tendon repair? | 83. | Increased tendon excursion |
| 84. | Rehabilitation protocols emphasize what type of motion? | 84. | Patient-controlled passive motion |
| 85. | If an active motion rehabilitation program is planned, how many crossing suture strands are necessary? | 85. | At least six strands |
| 86. | What are the two general types of rehabilitation protocols? | 86. | Duran (active extension, patient flexes passively) Kleinert (active extension, dynamic splint flexes passively) |
| 87. | What is the classic position for hand and wrist splinting after flexor tendon repair? | 87. | Wrist flexed 30 degrees Metaphalangeals (MCPs) flexed 70 degrees |
| 88. | What is the advantage of a continuous passive motion (CPM) device postoperatively? | 88. | Decreased rate of adhesions Maintains joint motion |
| 89. | What is the frequency of symptomatic flexor tendon adhesions at 3 months after repair? | 89. | 50% of patients require tenolysis at 3 months |
| 90. | What clinical exam findings are suggestive of postoperative tendon adhesions? | 90. | Full passive range of motion (ROM) Decreased active ROM |
| 91. | What is the reported advantage of antiadhesion gel application? | 91. | Improved active PIP motion |
| 92. | Has polyvinyl alcohol been shown to be effective against adhesions? | 92. | No, increases risk of rupture |
| 93. | Repairs rupture most commonly at what location? | 93. | Knot |
| 94. | Rupture is most often secondary to what? | 94. | Gap formation |
Flexor Pollicis Longus Injury
| 95. | What two pulleys are most important? | 95. | Oblique A1 |
| 96. | Is early motion advocated after flexor pollicis longus (FPL) repairs? | 96. | No |
| 97. | Why not? | 97. | Because FPL rupture rate is up to 20% (versus 2 to 5% for other digits) |
Rugger Jersey Finger (FDP Avulsion)
| 98. | What is the most commonly affected finger? | 98. | Ring finger |
| 99. | If the avulsed FDP remains attached to a bony fragment, to what location does it commonly retract? | 99. | A4 pulley |
| 100. | What is the treatment method of choice for an FDP avulsion with an attached fracture fragment? | 100. | Open reduction with internal fixation (ORIF) of fragment |
| 101. | If no fracture fragment is attached, what is the most important consideration in planning tendon repair and why? | 101. | Location of the retracted tendon Dictates the timing of the repair |
| 102. | What is the timing for repair of an avulsed FDP retracted all the way to the palm? Why? | 102. | Repair within 7 to 10 days Because vascular supply to retracted tendon is poor |
| 103. | If FDP retracts only to the PIP joint, what is the recommended timing of repair? Why? | 103. | Within 3 months (does not need to be as acute) Because vincula are intact |
Chronic Flexor Tendon Rupture
| 104. | If a patient has a chronic FDP rupture but the FDS is intact, what are the three general treatment options? | 104. | No treatment Fusion of the DIP joint Flexor tendon grafting |
| 105. | If a flexor tendon reconstruction is necessary for chronic rupture, what are the three general tendon graft options? | 105. | Palmaris longus (PL) Plantaris tendon Toe extensor |
| 106. | If a Hunter rod is used in the first stage of reconstruction, when is the definitive repair to be performed? | 106. | ≥3 months after 1st stage |
Trigger Finger
| 107. | What tendon is involved in the development of trigger thumb? | 107. | FPL |
| 108. | At what pulley does triggering occur? | 108. | A1 pulley |
| 109. | What percentage of patients respond to initial steroid injection? | 109. | 60% |
Infantile Trigger Thumb
| 110. | How often is the condition bilateral? | 110. | 25 to 33% |
| 111. | What percentage of cases with infantile trigger thumb will spontaneously resolve with observation? | 111. | 30% |
| 112. | What is the preferred treatment if it fails to resolve by age of 1? | 112. | Surgical release |
| 113. | How does infantile trigger finger surgery differ from that of the adult? | 113. | Must release and explore beyond the A1 pulley |
| 114. | What is the preferred direction of incision? | 114. | Transverse |
| 115. | What is the greatest risk of infantile trigger thumb surgery? | 115. | Radial digital nerve injury at the thumb |
Extensor Tendon Pathology
| 116. | Odd-numbered extensor tendon zones lie over what anatomic structures? | 116. | Joints |
| 117. | Even-numbered extensor tendon zones lie over what anatomic structures? | 117. | Bony shafts |
| 118. | What is the preferred rehabilitation for injuries between MCP (zone 5) and forearm (zone 9)? | 118. | Early motion on postoperative day (POD) 3 in a dynamic splint |
Mallet Finger
| 119. | How is mallet finger treated? | 119. | Volar extension splint (e.g., Stack splint) |
| 120. | Despite immobilization of the DIP, what should rehabilitation include? | 120. | Emphasize motion of PIP |
| 121. | A chronically untreated mallet finger may lead to what clinical condition? | 121. | Swan-neck deformity |
| 122. | What subset of mallet finger injuries requires surgery? | 122. | Bony mallet avulsion fractures with volar subluxation of the DIP joint Relative surgical indication is a surgeon with a mallet finger who wants to return to work |
Sagittal Band Injuries
| 123. | What is the role of the sagittal band? | 123. | Facilitates extension of the MP joint |
| 124. | What is the most common mechanism of sagittal band rupture? | 124. | Resisted flexion injury |
| 125. | What digit is most commonly affected? | 125. | Long finger |
| 126. | What is the classic presenting complaint? | 126. | Cannot actively extend Can maintain active extension |
| 127. | If sagittal band rupture is <2 weeks old, how is it generally treated? | 127. | Extension splint of metacarpophalangeal joint (MCP) with interphalangeal (IP) joints free |
| 128. | If more than 2 weeks old, how is it generally treated? | 128. | Extensor centralization procedure |
Fractures and Dislocations of the Hand and Digits
Carpometacarpal Joint
Thumb
| 129. | With thumb pinch, where are the greatest forces experienced? | 129. | Carpometacarpal (CMC) joint |
| 130. | What four ligamentous structures contribute to CMC joint stability? | 130. | Anterior oblique ligament (AOL) Dorsoradial capsule Posterior oblique ligament Intermetacarpal ligament |
| 131. | Of these, which is considered the most important for CMC stability? | 131. | AOL |
| 132. | How can a radiographic stress view be obtained to evaluate stability? | 132. | Anteroposterior (AP) view with both thumbs radially abducting against each other |
| 133. | With chronic AOL disruption, what happens at the CMC joint? | 133. | Metacarpal base subluxates dorsally |
| 134. | Dorsal CMC subluxation may be associated with what process at the MP joint? | 134. | Compensatory hyperextension at the MP joint |
| 135. | If MP hyperextension is present, what is the preferred intervention at the MP joint? | 135. | Capsulodesis or arthrodesis to correct |
| 136. | In what direction do degenerative changes occur at the CMC joint? | 136. | Volar to dorsal |
| 137. | Degeneration at what other site is a contraindication to CMC arthrodesis? | 137. | Scaphoid-trapezium-trapezoid (STT) arthritis |
| 138. | In older patients, what is the most common procedure for diffuse CMC arthritis? | 138. | Trapezium excision with or without ligament interposition |
| 139. | What are the disadvantages of resection arthroplasty for CMC arthritis? | 139. | Weakness with pinch Thumb shortening Decreased ability to adduct thumb |
| 140. | Quick review: in what fracture does the deep anterior oblique ligament (palmar beak ligament) also play a key role? | 140. | Anterior oblique ligament is the primary restraint in a Bennett’s fracture Anterior oblique ligament anchors volar lip of metacarpal to tubercle of the trapezium; small volar lip fragment remains attached to anterior oblique ligament, which is attached to trapezium |
| 141. | What tendon provides the primary displacing force with a Bennett’s fracture? | 141. | Abductor pollicis longus |
Other Digits
| 142. | What is the ideal radiographic view for identifying fourth/fifth carpometacarpal dislocations? | 142. | 30 degree pronated view |
Metacarpophalangeal and Interphalangeal Joints
Thumb Metaphalangeal Ulnar Collateral Ligament Injuries
| 143. | Does the ulnar collateral ligament (UCL) generally avulse proximally or distally? | 143. | Distally |
| 144. | What two clinical findings are suggestive of thumb UCL ligament injury? | 144. | Over 45 degrees opening on stress of UCL Over 15 degrees of side-to-side difference |
| 145. | How is the accessory UCL tested in isolation? | 145. | Stress in full extension |
| 146. | How is the proper UCL tested in isolation? | 146. | Stress in 30 degrees of flexion |
| 147. | What is a Stener lesion? | 147. | The distal edge of the ulnar collateral ligament displaces superficial and proximal to the adductor aponeurosis. It becomes lodged between the adductor pollicis aponeurosis and its normal position. It is clinically significant because it will have persistent instability due to lack of healing. It is an indication for surgery. |
| 148. | What structure is interposed in a Stener lesion and prevents the UCL from healing? | 148. | Adductor pollicis aponeurosis |
Metacarpophalangeal Arthrodesis
| 149. | The greatest MCP wear occurs with what hand motion? | 149. | Grasping |
| 150. | What is the optimal position for thumb MP joint arthrodesis in flexion, pronation, and abduction? | 150. | 10 degrees flexion 10 degrees pronation 0 degrees abduction |
Collateral Ligament Injury Metacarpophalangeal Joint
| 151. | What is the preferred treatment for simple (partial) tear? | 151. | Buddy tape to adjacent digit for 3 weeks |
| 152. | What is the preferred treatment for complete tear? | 152. | Buddy tape to adjacent digit for 6 weeks |
| 153. | Operative intervention is indicated for what situation? Why? | 153. | Complete tear of radial collateral ligament (RCL) of index PIP joint Surgery restores stability in pinch |
| 154. | What is the most likely diagnosis in a patient with acute loss of active and passive MCP motion but with a PIP that remains mobile? | 154. | Catching and locking of the collateral ligament on an osteophyte |
| 155. | What is the preferred initial treatment if reducible? | 155. | Reduce and observe |
| 156. | What is the preferred treatment if irreducible? | 156. | Surgical excision of the cause of collateral ligament catching (e.g., osteophyte, joint debridement) |
Dorsal Dislocation of the Proximal Interphalangeal Joint without Fracture
| 157. | Interposition of what structure may result in an incomplete reduction? | 157. | Volar plate |
| 158. | With dorsal dislocations, does the volar plate generally avulse proximally or distally? | 158. | Distally |
| 159. | What is the treatment if a stable reduction is achieved? | 159. | Early active motion |
| 160. | What if the reduction remains unstable? | 160. | Extension block splint |
| 161. | If untreated, what long-term complication may develop? | 161. | Swan-neck deformity, PIP hyperextension |
Volar Dislocation of the Proximal Interphalangeal Joint Without Fracture
| 162. | With a volar dislocation, the head of the phalanx is often entrapped between what two structures? | 162. | Lateral band Central slip (straight volar dislocation = central slip only) |
| 163. | How can the intrinsics best be relaxed to facilitate reduction? | 163. | Flex finger at MP joint |
| 164. | What structure is commonly injured with a volar dislocation? What is the resultant deformity? | 164. | Central slip commonly injured (also in rotatory dislocation) Acute boutonniere deformity |
Fracture-Dislocation at the Proximal Interphalangeal Joint (Pilon-Type Injury)
| 165. | What is the preferred treatment if fracture fragments are nondisplaced? | 165. | Extension block splint |
| 166. | What is the preferred treatment if fracture fragments are displaced and comminuted? | 166. | Traction device |
| 167. | What is the preferred treatment if fracture is a single displaced fragment? | 167. | ORIF if >25% but <40% articular surface involved |
| 168. | What is the salvage procedure if treatments are unsuccessful? | 168. | Volar plate arthroplasty |
Posttraumatic and Osteoarthritic Changes at the Proximal Interphalangeal and Distal Interphalangeal Joints
| 169. | With what pathologic process is a mucous cyst associated? | 169. | Arthritic DIP joint |
| 170. | What is the natural history of mucous cysts? | 170. | 20 to 60% spontaneously resolve |
| 171. | What is the indication for operative treatment of a mucous cyst? | 171. | Persistent drainage due to increased risk of infection |
| 172. | In general, what is the preferred treatment for posttraumatic arthrosis of PIP and DIP joints? | 172. | Fusion |
| 173. | What type of fixation is generally best for IP joint fusion? What is the preferred position? | 173. | Screws are best for DIP joints, can use Kirschner (K) wires or screws for PIP joint DIP joint 0 to 5 degrees, PIP (index = 40, middle = 45, long = 50, small = 55) |
Quick Review and Clarification of Key Points: For each of the following injured structures, is the avulsion generally distal or proximal?
| 174. | Volar plate at PIP. | 174. | Distal |
| 175. | UCL (thumb MCP). | 175. | Distal |
| 176. | MCL at the elbow. | 176. | Distal |
Posttraumatic Hand Deformity
Swan-Neck Deformity
| 177. | What are the four possible causes of a swan-neck deformity? | 177. | Lax PIP volar plate Mallet finger Volarly subluxed MCP joint (as with rheumatoid arthritis) Chronic FDS laceration |
| 178. | What is the resultant PIP position? | 178. | Hyperextended |
| 179. | What is the DIP position? | 179. | Flexed |
| 180. | What are three treatment options for swan-neck deformity? | 180. | Silver ring splint/figure-8 splint Central slip tenotomy Oblique retinacular ligament reconstruction |
Boutonniere Deformity
| 181. | Boutonniere deformity results from an injury to what two structures? | 181. | Central slip Triangular ligament |
| 182. | Then what happens? | 182. | Lateral bands sublux volarly |
| 183. | What is the resultant PIP position? | 183. | Flexion |
| 184. | What is the DIP position? | 184. | Hyperextension |
| 185. | What test is used for evaluation of a boutonniere finger? | 185. | Elson test: bend PIP to 90 degrees; if resisted PIP extension sends DIP into rigid extension, then positive |
| 186. | In what situation is acute operative intervention for boutonniere deformity required? | 186. | A displaced avulsion fracture fragment is present |
| 187. | What is the nonoperative treatment of acute boutonniere? | 187. | Six weeks of PIP extension splint wear Active flexion of the DIP (pulls lateral bands dorsally) |
| 188. | What are two operative treatments for chronic boutonniere deformity? | 188. | Terminal tendon tenotomy (Fowler) Central slip reconstruction |
Intrinsic Minus (Claw) Hand
| 189. | What nerves are involved in an intrinsic minus hand? | 189. | Median (lumbrical muscles) Ulnar (lumbricals and IO) |
| 190. | With claw hand, what is the position of the MCPs and IPs? | 190. | MPs hyperextended IPs flexed |
| 191. | What two clinical problems are associated with intrinsic minus hand? | 191. | Decreased grip strength Decreased pinch strength |
| 192. | What is the goal of operative intervention? | 192. | Correct MCP hyperextension Facilitate IP extension |
| 193. | What role do the intrinsics have on the thumb? | 193. | Increase pinch |
Intrinsic Plus Hand
| 194. | With intrinsic plus hand, what is the position the MCPs and IPs? | 194. | MCPs flexed IPs extended |
| 195. | What clinical test is most relevant? | 195. | Bunnell test |
| 196. | How does the Bunnell test work? | 196. | Differentiates extrinsic tightness from intrinsic tightness If intrinsics are tight, when MCP is extended (relaxes EDC), cannot flex the PIP joints If extrinsics are tight, when MCP is flexed (tensions EDC), cannot flex PIP joints |
| 197. | What does nonoperative treatment involve? | 197. | Intrinsic stretch (MP extension/IPs flexed) |
Wrist Trauma and Associated Disorders
Scaphoid Fracture
| 198. | In general, if you see a fracture of the scaphoid, you should also exclude what two injuries? | 198. | Perilunate dislocation Capitate fracture |
| 199. | For nondisplaced fractures of the scaphoid, what is the preferred time of immobilization for distal pole fracture? | 199. | 6 weeks |
| 200. | What is the preferred time of immobilization for scaphoid waist fracture? | 200. | 12 weeks |
| 201. | What is the preferred time of immobilization for proximal pole fracture? Thus, what should be considered? | 201. | 5 months Consider surgery for proximal pole fractures even if nondisplaced |
| 202. | Is it generally necessary to include the thumb in the cast? | 202. | No proven benefit to including the thumb (controversial) |
| 203. | What is the reported advantage of a long arm cast over a short arm cast? | 203. | Decreased time to union |
| 204. | What radiographic findings are suggestive of an unstable scaphoid fracture? | 204. | Humpback deformity (flexed and shortened) Displacement >1 mm Scapholunate angle >60 degrees Capitolunate angle >15 degrees |
| 205. | What is the treatment of choice for unstable scaphoid fractures? | 205. | ORIF |
| 206. | ORIF remains an option for a missed fracture for how long? | 206. | Until arthritic changes are seen Generally up to 5 years after injury |
| 207. | What is the blood supply to the scaphoid? | 207. | Major: dorsal scaphoid branch of the radial artery in a retrograde fashion (supplies 70 to 80%, including entire proximal pole) Volar scaphoid branch of the superficial branch of the radial artery in a retrograde fashion (supplies 20 to 30% distal of scaphoid) |
| 208. | What is the avascular necrosis (AVN) rate for a proximal 1/5 fracture? | 208. | 100% |
| 209. | What is the AVN rate for proximal 1/3 fracture? | 209. | 33% |
| 210. | In terms of vascular supply, which approach to the scaphoid is generally safer? | 210. | Volar approach, because blood supply enters distally and dorsally |
| 211. | At what anatomic location is the dorsal approach considered safe from a vascular standpoint? | 211. | Dorsal approach is safe proximal to the ridge on the waist |
| 212. | What is the plane of dissection for the volar scaphoid approach? | 212. | Between FCR and radial artery |
| 213. | What two structures should be repaired once volar surgery is complete? | 213. | Long radiolunate ligament Radioscaphocapitate |
| 214. | The dorsal approach is generally used for what type of scaphoid fracture? | 214. | Proximal pole fractures |
| 215. | What two structures must one be careful to avoid? | 215. | Superficial radial nerve Radial artery (deep) |
| 216. | At the time of surgery, the proximal pole is known to be vascularized in what situation? | 216. | If it is observed to bleed |
| 217. | If the scaphoid fractures goes on to nonunion, what are the available graft types? | 217. | Inlay: if no associated collapse (92% union rate) Interposition: if associated collapse or scaphoid deformity present (70 to 90% union rate) |
| 218. | A vascularized graft should be used for? | 218. | Scaphoid nonunion with AVN |
| 219. | On what artery is the vascularized graft based? | 219. | 1,2 intercompartmental supraretinacular artery |
Disorders of the Other Carpal Bones
Preiser’s Disease
| 220. | What is Preiser’s disease? | 220. | AVN of the scaphoid without fracture |
| 221. | What is the first-line treatment of Preiser’s disease? | 221. | Trial of immobilization |
| 222. | In what percentage of patients is immobilization alone successful? | 222. | 20% |
| 223. | If nonoperative treatment fails, what are the options? | 223. | Vascularized graft Scaphoid excision and four-corner fusion |
Avascular Necrosis of the Capitate
| 224. | What is the first-line treatment of capitate AVN? | 224. | Trial of immobilization |
| 225. | If immobilization fails, what are the surgical treatments? |
