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Relative  Active  MotionA  treatment   approach   for  extensor  tendon   injuries   and  PIP  flexion  

contractures

Amanda   Whitley   OTR/L,   CLT,  CHT

Concepts

• First  studied   in  cadavers  in  1970s• Introduced   into   clinical   practice   in  1981  by  Dr.  Wyndell H.  Merritt

• Prompted   by  complications   observed   with  immobilization   protocols

Theory

• Multiple   tendons   that  originate   from  one  muscle   can  be  positioned   such  that   the  injured   or  repaired   tendon   is  unloaded   while  at  the  same  time   limiting   excursion.

Evolution  of  RM  orthosis• Elimination   of  finger   gutter   strap• Lesser   degree   of  relative   extension• Elimination   of  wrist   orthosis  in   zone  V  and  VI• Addition  of   zone  IV,   VII,   and  sagital band   repair• Chronic  and  Acute  boutonniere   deformity• Postop  tendon   transfers,   flexor   tendon  and  digital  nerve   repairs,   interosseous  muscle   tears,  treatment   of  joint   stiffness

Terminology

• The  Merritt   Splint   or  Wyndell Merritt   Splint• ICAM  (immediate   controlled   active  motion)• Yoke• Border   digit  splint• SB  bridge  splint• Pop  up  splint• RMF  (relative   motion   flexion)   or  RME  (relative  motion   extension)

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“Active  Redirection”• Concept   of  blocking   normal   joints   in  order   to  redirect   the  muscle   power   to  the  stiff  joints   in  order   to  move  them

• Blocking   vs.  active  redirection?

(Colditz,  2014)

Long  Extensor  Repair  – Zone  IV-­‐VII

• RME  orthosis   fabricated   with   repaired  tendon(s)   in  15-­‐20  degrees  greater  MCP  extension   than  adjacent   digits   for  6  weeks  and  wrist   control   orthosis   with   wrist  extended   20-­‐25   degrees  separate  orthosis

• 3  weeks  post  op:    wrist   control   orthosis  discontinued

Therapy  Goal

• To  regain  full  IP  and  MCP  flexion   and  extension   in  involved  and  adjacent  digits   within   orthosis   as  soon   as  possible   post   repair

RMS:  postop   rehabilitation  study• Average  8  therapy   visits  required• Return   to   work  average  18  days• Continued   therapy  after  6  weeks  was  only   necessary  for  patients   with  complex   injuries   or  delayed  repair  and  splinting

• Average  discharge   at  7  weeks

[Merritt  et  al.   2014] 10

Sagital Band  Rupture  – Acute/Chronic

• Acute  sagital band   rupture   less  than   2-­‐3  weeks  post   injury   have  good  expected  outcome   for  re-­‐centralizing   the  tendon.

Acute  SB  Rupture  Protocol

• Custom   RME  orthosis   at  15-­‐20  degrees  of  relative  extension   to  be  worn   6-­‐8  weeks

• Therapist   should   visually  check  tendon  recentralization   and  adjust   accordingly  based  on  pain   response   as  well.

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Chronic  SB  rupture  requiring  surgical  repair

• Same  parameters   as  acute   rupture  • Orthosis   indicated   x  6  weeks

MP  flexion  =  tension  on  extensor  tendon  pulls  the  lateral  bands  dorsally  through  the  lateral  slips

Why  position  a  boutonniere  in  MP  flexion?

• Allows   the  intrinsic   muscles   to  relax  and  moves  the   lateral  bands   dorsally

• The  long  extensor   pulls   the  lateral   bands  dorsally   through   the  dorsal   slips

What  happens  to  PIP  joint  in  MP  extension?

• Intrinsics tighten   and  do  not  allow   the  lateral  bands  to  move  dorsally

• The  long  extensor   pulls   on  the   lateral  band  which   moves  the  lateral  bands   volarly

• Hyperextension   of  MP  joint   creates  even  more  tension   and  contributes   to  why  boutonniere   of  the  SF  is  so  difficult   to  rehab.

Acute  Closed  Boutonniere

• Determine   if  patient   has  full   extension   of  PIP  joint

• RMF  orthosis   in  15-­‐20  relative   flexion   with   no  wrist   component

• Orthosis   to  be  worn   6  weeks  with  functional  use  of  hand

Open  Acute  Boutonniere

• RMF  orthosis   15-­‐20  degrees   indicated   for  6  weeks

• May  resume  functional   use  of  hand  right   away  and  encouraged   to  do  so

• Patient   will  require   closer   monitoring   initially  to  assess  ROM  progress

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Chronic   Boutonniere

• Serial  cast  to  gain  as  much   passive  PIP  extension   as  possible   (greater   than  -­‐30)

• RMF  orthosis   x  3  months

Dupuytren’s Release/Xiaflex

• Custom   fabricate   forearm   based  night  time  extension   orthosis   to  include   involved  digits

• Night   time  orthosis   to  be  worn   3-­‐6  months• RMF  custom   orthosis   for  day  time   wear  for  6-­‐8  weeks

Considerations

• Splinting   time   frame  post  long  extensor   repair

• Wrist   Control   Orthosis

• Does  not   apply  to  all  extensor   repairs

Splinting   Time  Frame• Studied   140  patients   post  extensor   tendon  repair   splinted   before  and  after  5  days  postop

• At  6  weeks  postop,   TAM  of  before  5  days  group   was  97.8%  and  after  5  days  89.5%

• Primarily  due  to  less  normal  hyperextension  of  MP  and  some  with  PIP  extension  lag

• Concluded   that   splinting   within   a  few  days  significantly   better   results   for  long  extensors

(  Merritt,  et   al.   2014)

Wrist  Control  Orthosis• Typically  used  in  conjunction   with   relative  motion   orthosis   x  3  weeks  post  extensor  tendon   repair

• Evidence  that   it   is  not   necessary  to  protect   the  tendon

• Therapist/Surgeon   may  determine   necessity  case  by  case

• evaluation,  work  level,  compliance  concerns

Contraindications• Does  not   apply  to  EPL  repair• When  all  6  finger  extensors   are  severed

• Dynamic    splinting  or  immobilization  preferred  

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Advantages  of  Relative  Motion  Splinting

• Simple  design• Less  costly• Allows   early  functional   use  of  involved   hand• Straight   forward   HEP  instruction• Compliance

• Less  restrictive/allows  early  use  of  hand• Functional  use  vs.  regimented  A/PROM  HEP

Early  Return  to  Work   Study

• Retrospective   review  of  46  consecutive   single  finger   zone  V  and  VI  extensor   tendon   repairs

• Received   RMS  or  immobilization   splinting  • Mode  of  rehab  was  determined   by  delay  of  referral   to  therapy  due   to  administrative/clinic  availability   vs  any  surgical  variable

• Before  7  days  RMS.    After  7  days  cont immobilization

(Hirth,  et  al.   2011)

Immobilization  Group

• Resting   pan  splint   at  IE  to  be  worn   at  all  times• Mobilization   began  at  4  weeks  post   op• Weekly  therapy  sessions• No  “heavy”  tasks  8-­‐10  weeks

mRMS Group• Initiated   between   2  and   7  days  post  op• mRMS (day  wear)  and  resting   orthosis   (night)  fabricated   at  IE

• No  specific   HEP.    Encouraged   functional   use• Instructed   to  avoid  composite   wrist   and  digit  flexion

• Resting   orthosis   d/c  at  4  weeks• Wore  mRMS 8-­‐10  weeks  with  heavy  tasks

Results• At  6  weeks

• Immobilization  group  mean  category  of  fair• rRMS mean  category  good

• At  12  weeks• Both  groups  had  statistically  significant  improvements  in  TAM  scores

• Concludes:    ROM  similar   at  12  weeks  postop.    rRMS showed   greater  ROM  gains  by  6  weeks  and  significant   improvement   in  earlier   RTW  and  functional   use

Return  to  Work

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RMF  Orthosis   Fabrication

Design  cont.

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References• Szekeres,   M.  (2016).  Clinical  revelance commentary  in  response  to:  

Relative  motion  orthosis  in  the  management  of  various  hand  conditions:  A  scoping  review.  Journal  of  Hand  Therapy,  29,  505-­‐506.

• Colditz,  J.  C.  (2014).  Active  Redirection  Instead  of  Passive  Motion  for  Joint  Stiffness.  ASHT  Times,  21  (3).

• Hirth,  M.  J.,  Bennet,  K.,  Mah,  E.,  Farrow,  H.  C.,  Cavallo,  A.  V.,  Ritz,  M.,  &  Findlay,  M.  W.  (2011).  Early  return  to  work  and  improved  range   of  motion  with  modified  relative  motion  splinting:  a  retrospective   comparison  with  immobilization  splinting  for  zones  V  and  VI  extensor  tendon  repairs.  Journal  of  Hand  Therapy,  16  (4).

• Merritt,   W.  H.  (2014).  Relative  Motion  Splint:  Active  Motion  After  Extensor  Tendon  Injury  and  Repair.   J  Hand  Surg Am.,  39.

• Hirth,  M.,  Howell,  J.  W.,  &  O’Brian,  L.  Relative  motion  orthoses  in  the  management   of  various  hand  conditions:  A  scoping  review.  Journal  of  Hand  Therapy,  29,  405-­‐432.