Embed Size (px)
DESCRIPTION
California ASHT Meeting 3/26/11
Citation preview
Flexor Tendon Rehabilitation:Foundational Science and
Critical Thinking
Rebeccavon der Heyde,
PhD, OTR/L, CHT
Maryville UniversitySt. Louis, Missouri
Variables
1. Tendon Healing2. Work of Flexion3. Tendon Excursion4. Force
Effective clinical decision-making following tendon repairrequires a working knowledge of these variables that can
be influenced by careful evaluation, timing, and educated progression of therapeutic interventions.
Tendon Healing
Early Conservatism Mason & Allen (1941)
Exudative and formative stages Immobilization during exudative Stimulation of strength and tendon glide
deferred until formative Potenza (1963)
Immobilization protocol; injured tendons depend solely on extrinsic processes for healing
Peacock (1965) “One-wound” concept
Extrinsic Healing
Paradigm Shift Lundborg & Rank (1978, 1980)
Intrinsic healing nourished by synovial fluid Gelberman et al. (1980-1989)
Application of stress through early passive motion leads to more rapid recovery of tensile strength, fewer adhesions, improved excursion, better nutrition, and minimum repair site deformation
Hitchcock, Light, & Bunch (1987) Loss of strength and softening of tendons often
observed post-operatively are not inevitable; rather a consequence of immobilization
Clinical Implications Intrinsic healing capability of flexor tendons Beneficial effects of early motion
Increased strength and excursion Fewer peritendinous adhesions
The practice of immobilization following flexor tendon
repair, unfortunately not obsolete, should be replaced by early motion protocols in the vast
majority of situations.
Work of Flexion
Timing of Early Motion Inflammatory phase
48-72 hours Fibroblastic phase
4 days through 5 weeks Remodeling phase
Through 112 days
(Strickland, 2005)
Work of Flexion (WOF) Mayo Clinic: Amadio and colleagues Work necessary for active flexion Influenced by intrinsic and extrinsic
factors Surface friction, bulk of the repaired tendon,
tendon adhesions, mass of the digit, joint stiffness, soft tissue resistance, and resistance of the antagonistic musculature
Work of Flexion (WOF) Tanaka et al. (2003)
Interaction between gliding resistance and WOF
WOF decreased on 5th post-operative day
Increased at day 7 with notable adhesions and stiffness
Increased number of strands correlated with increased WOF
Work of Flexion (WOF) Zhao et al. (2004)
Day 7 as least favorable Day 5 as optimal
Zhao et al. (2005) “Safe zone” for early motion Lower limit: WOF Upper limit: repair site strength Day 5 with decreased WOF as compared
to day 1
Amadio, 2005
Edema and WOF Cao et al. (2005-2008)
Increased gliding resistance proportional to area and severity of edema
Gentle motion noted to reduce gliding resistance
No significant difference in tendon gliding force or WOF between days 3-9 Day 4 or 5 as ideal Day 7-9 as acceptable
Observation of edema should inform the range, frequency, and speed of exercise
Clinical Implications Timing of referral to hand therapy? Optimal initiation of early motion at day 4-5 Day 7 as potentially least favorable Moderate to maximal edema creates
increased resistance on the healing tendon • Decrease range of motion and frequency of
exercise• Tendon glide with slow and controlled
movement
Tendon Excursion
Excursion
Synonymous with tendon glide The amount of differential motion that
occurs between the tendon and the surrounding structures– Other tendons– Tendon sheath– Local bony architecture
Calculated using mathematical models and measurement of actual tendons In vivo and in vitro
Mathematical Calculation Radian
standard unit of angular measurement equal to 57.29°
90º degrees MP motion = 1.57 radians 105º degrees PIP motion = 1.83 radians 75º degrees DIP motion = 1.31 radians
Moment Arms (Brand, 1985) Distance between the line of action of the
tendon and the axis of rotation of the corresponding joint
MP = 1.0cm, PIP = 0.75cm, DIP = 0.5cm
Mathematical Calculation Multiplication of the moment arm by the
radians results in a mathematical calculation of the tendon excursion at each joint MP: 1.57 x 1.0cm = 1.57cm FDP excursion PIP: 1.83 x 0.75cm = 1.37cm FDP excursion DIP: 1.31 x 0.5cm = 0.66cm FDP excursion
Normal FDP tendon with a total active motion of 270º will demonstrate 3.6cm (36mm) of tendon excursion over the MP, PIP, and DIP joints as it
moves from full extension to full flexion
Mathematical Calculation Tendon excursion can be broken down to
10º increments for comparative purposes
MP: 1.57cm of excursion divided by 9 0.17cm or 1.7mm of excursion for every 10º of motion
PIP: 1.37cm of excursion divided by 10.5 0.13cm or 1.3mm of excursion for every 10º of motion
DIP: 0.66cm of excursion divided by 7.5 0.09cm or 0.9mm of excursion for every 10º of motion
In Vitro Calculations Wehbe & Hunter (1985)
Normal tendon model: wrist, MP, PIP, DIP FDP excursion of 33mm (range 19-43) during synergistic
motion Cooney et al. (1989)
Cadaveric model: PIP and DIP FDP excursion of 19.8mm during synergistic motion
Zhao et al. (2002) Partial laceration in a canine model: PIP and DIP FDP excursion of 12.3mm pre-operatively and 11.4mm
post-operatively during synergistic motion
Mathematical All joints: 42.5mm, PIP and DIP: 20.3mm
In Vivo Calculation Silfverskiold et al. (1992)
Metal markers in FDP tendons; repair in zone II Dorsal blocking splint with digital traction
0.3mm per 10º of controlled DIP motion 1.2mm per 10º of controlled PIP motion
Active motion after four weeks 0.9mm per 10º of DIP motion 1.4mm per 10º of PIP motion
Mathematical 0.9 and 1.3mm per 10º of DIP and PIP motion
Suggested Excursion
3-5mm (Duran & Houser, 1975)
3-4mm (Gelberman et al., 1986)
Optimal threshold of 1.7mm (Silva et al., 1999)
“ The ideal postoperative therapy would use the
smallest force to achieve the largest tendon excursion.”
(Zhao et al., 2002)
Passive, protected digital extension
3-8mmDistal
Duran & Houser (1975)
Place and hold synergistic flexion
FDS 26mmFDP 33mmProximal
Wehbe & Hunter (1985)
Active straight fist
FDS 28mmFDP 27mmMax FDSProximal
Wehbe & Hunter (1985)
Active hook fist
FDS 13mmFDP 24mmMax differentialProximal
Wehbe & Hunter (1985)
Active composite fist
FDS 24-26mmFDP 32-33mmMax FDPProximal
Wehbe & Hunter (1985)
Active, isolated PIP flexion
~13mm (calculated)FDPProximal
Active, isolated DIP flexion
~6.5mm (calculated) FDPProximal
Clinical Implications Many and confusing approaches to
calculate tendon excursion
Straight fist: maximal FDS excursion Hook fist: maximal differential excursion Synergistic motion: increases total and
differential excursion
Limited range of motion to avoid adhesions Between 30-40° at the PIP and DIP
Force
Understanding Forces Increased force in rehabilitation does not
accelerate accrual of strength (Boyer, 2001) Force analysis enables safe progression
within reasonable time frames Force analysis tells us both:
HOW TO PROGRESS AND
HOW NOT TO PROGRESS
Savage, 1988 Least active force to produce motion as
“minimal active tension” Measurement of passive tension Increased passive tension results in
increased “minimal active tension” Wrist extension with MP flexion as
producing least passive tension, and therefore decreasing “minimal active tension”
Cooney et al., 1989
Cadaveric study of 4 arms Comparison of Klienert and Brooke Army
Hospital splints/motion with “synergistic” motion Passive wrist and digital motion
“Synergistic” motion demonstrated highest amount of FDS, FDP, and differential excursion
Strickland & Cannon, 1993
The Indiana Protocol Place and hold digital flexion with the
wrist extension, followed by active digital extension with wrist flexion
Ambiguous as to active versus passive wrist extension and flexion
Evans & Thompson, 1993
Minimal Active Muscle Tendon Tension MAMTT 45° wrist extension 83° MP flexion 75° PIP flexion 40° DIP flexion
Lieber et al., 1996-1999
“Normal” tendons; canine model Forces exerted on the flexor tendon
as highly dependent on passive wrist position
Synergistic motion resulted in low passive forces on the flexor tendon with high excursion
Zhao et al., 2002
80% laceration; canine model Passive digital flexion during passive
wrist extension as effective “pulling force” to facilitate proximal glide
Synergistic Motion
1. Decreases passive tension2. Decreases active tension3. Increases excursion4. Effectively facilitates proximal glide
“ The ideal postoperative therapy would use the smallest force to achieve the largest tendon
excursion.” (Zhao et al., 2002)
Combined Digit and Wrist Flexion
1. Increases passive tension2. Increases active tension
Asking your patient to either perform placehold or active fisting when the wrist is
flexed actually demands MORE force than the same motions performed with the
wrist extended!
Strickland, 1993; Urbaniak et al., 1975Strickland, 1993; Urbaniak et al., 1975
0
1000
2000
3000
4000
5000
6000
7000
8000
Repair 1 Week 3 Weeks 6 weeks
Two Strand
Four Strand
Six Strand
Passive
Light Active
Strong Grasp
Passive, protected digital extension
200-300gm
Urbaniak et al. (1975)
Place and hold synergistic flexion
900gm
Lieber et al. (1999)
Active straight fist
1100gm
Greenwald et al. (1994)
Active hook fist
1300gm
Greenwald et al. (1994)
Active composite fist
400-4000gm
Schuind et al. (1992)
Active, isolated PIP flexion
900gm
Schuind et al. (1992)
Active, isolated DIP flexion
1900gm
Schuind et al. (1992)
Strickland, 1993; Urbaniak et al., 1975Strickland, 1993; Urbaniak et al., 1975
0
1000
2000
3000
4000
5000
6000
7000
8000
Repair 1 Week 3 Weeks 6 weeks
Two Strand
Four Strand
Six Strand
Passive
Synergistic
Straight Fist
Exercise Excursion Force
Passive protected extension 3-8mm
distal
200-300gm
Place and hold synergistic flexion
with active wrist extension
26/33mm
proximal
900gm
Active straight fist 28/27mm
FDS proximal
1100gm
Active hook fist 13/24mm
differential proximal
1300gm
Active composite fist 24-26/32-33mm
FDP proximal
400-4000gm
Active, isolated PIP flexion ~13mm
FDP proximal
900gm
Active, isolated DIP flexion ~6.5mm
FDP proximal
1900gm
Two strand repair withepitendinous suture
(Strickland, 1993; Urbaniak et al., 1975)(Strickland, 1993; Urbaniak et al., 1975)
0 week 2500gm • Passive, protected extension
• Place and hold synergistic flexion
with active wrist extension
1 week 1200gm • Passive, protected extension
• Place and hold synergistic flexion
with active wrist extension
Add (according to measurements)
• Active straight fist
3 weeks 1700gm Add (according to measurements):• Active hook fist
6 weeks 2700gm Add (according to measurements):
• Active composite fist
• Active, isolated joint motion
• Resisted, composite fist
Measure, Measure, Measure!
In the literature…
“ The melding of unique anatomy, injury, surgery, and physiologic response, notwithstanding psychological response, necessitates an individualized approach in crafting a successful outcome from flexor tendon repair.”
(Groth, 2004)
Measurement
Strickland & Glogovac, 1980
Active PIP + DIP flexion – extension lag x 100 175°
= % of normal active PIP and DIP motion
Groth, 2004
Current DIP flexion – previous DIP flexionprevious DIP flexion
= % resolution of active lag between therapy sessions
Strickland’s Original Classification
Excellent 85-100%
Good 70-84%
Fair 50-69%
Poor <50%
ReferencesMason ML, Allen HS. The rate of healing of tendons: An experimental
study of tensile strength. Ann Surg 1941;113:424-57.Potenza AD. Critical evaluation of flexor tendon healing and adhesion
formation within artificial digital sheaths. An experimental study. J Bone Joint Surg 1963;45A:1217-1233.
Peacock EE Jr. Biological principles in the healing of long tendons. Surg Clin North Am 1965;45:461-476.
Lundborg G, Rank F. Experimental intrinsic healing of flexor tendons based on synovial fluid nutrition. J Hand Surg 1978;3:21-31.
Lundborg G, Rank F. Experimental studies on cellular mechanisms involved in healing of animal and human flexor tendon in synovial environment. Hand 1980;12:3-11.
Gelberman RH, Menon J, Gonsalves M, Akeson WH. The effects of mobilization on the vascularization of healing flexor tendons in dogs. Clin Orthop 1980;153:283-289.
ReferencesGelberman RH, Vande Berg JS, Lundborg GN, Akeson WH. Flexor tendon
healing and restoration of the gliding surface: An ultrastructural study in dogs. J Bone Joint Surg 1980;65A:583-598.
Gelberman RH, Amiel D, Gonsalves M et al. The influence of protected passive mobilization on the healing of flexor tendons: A biochemical and microangiographic study. Hand 1981;13:120-128.
Gelberman RH, Woo SL-Y, Lothringer K et al. Effects of early intermittent passive mobilization on healing canine flexor tendons. J Hand Surg 1982;7:170-175.
Gelberman RH, Woo SL-Y. The physiological basis for application of controlled stress in the rehabilitation of flexor tendon injuries. J Hand Ther 1989;2:66-70.
Hitchcock TF, Light TR, Bunch WH et al. The effect of immediate constrained digital motion on the strength of flexor tendon repairs in chickens. J Hand Surg 1987;12A:590-595.
Strickland JW. The scientific basis for advances in flexor tendon surgery. J Hand Ther 2005;18:94-100.
ReferencesTanaka T, Amadio PC, Zhao C et al. Gliding resistance versus work of
flexion-two methods to assess flexor tendon repair. J Orthop Res 2003;21:813-818.
Zhao C, Amadio PC, Paillard P et al. Digital resistance and tendon strength during the first week after flexor digitorum profundus tendon repair in a canine model in vivo. J Bone Joint Surg 2004;86:320-327.
Zhao C, Amadio PC, Tanaka T et al. Short-term assessment of optimal timing for postoperative rehabilitation after flexor digitorum profundus tendon repair in a canine model. J Hand Ther 2005;18:322-328.
Cao Y, Tang JB. Investigation of resistance of digital subcutaneous edema to gliding of the flexor tendon: An in vitro study. J Hand Surg 2005;30A:1248-1254.
Cao Y, Tang JB. Resistance to motion of flexor tendons and digital edema: An in vivo study in a chicken model. J Hand Surg 2006;31A:1645-1651.
ReferencesCao Y, Chen CH, Wu YF et al. Digital oedema, adhesion formation and
resistance to digital motion after primary flexor tendon repair. J Hand Surg 2008;33E:745-752.
Brand PW. Clinical mechanics of the hand. St. Louis: CV Mosby 1985:257-259.
McGrouther DA, Ahmed M. Flexor tendon excursions in “no man’s land”. Hand 1981;13:129-141.
Wehbe MA, Hunter JM. Flexor tendon gliding in the hand. Part I. In vivo excursions. J Hand Surg 1985;10A:570-574.
Wehbe MA, Hunter JM. Flexor tendon gliding in the hand. Part II. Differential gliding. J Hand Surg 1985;10A:575-579.
Cooney WP, Lin GT, An K-N. Improved tendon excursion following flexor tendon repair. J Hand Ther 1989;2:102-106.
Zhao C, Amadio PC, Zobitz ME et al. Effect of synergistic motion on flexor digitorum profundus tendon excursion. Clin Orthop and Rel Res 2002;396:223-230.
ReferencesSilfverskiold KL, May EJ, Tornvall AH. Flexor digitorum profundus tendon
excursions during controlled motion after flexor tendon repair in zone II: A prospective clinical study. J Hand Surg 1992;17A:122-131.
Gelberman RH, Botte MJ, Spiegelman JJ, Akeson WH. The excursion and deformation of repaired flexor tendons treated with protected early motion. J Hand Surg 1986;11A:106-110.
Duran RE, Houser RG. Controlled passive motion following flexor tendon repair in zones two and three. In: The American Academy of Orthopaedic Surgeons: Symposium on tendon surgery in the hand. St. Louis: Mosby;1975:105-114.
Silva MJ, Brodt MD, Boyer MI et al. Effects of increased in vivo excursion on digital range of motion and tendon strength following flexor tendon repair. J Orthop Res 1999;17:777-783.
Urbaniak JR, Cahill JD, Mortenson RA. Tendon suturing methods: Analysis of tensile strengths. In: The American Academy of Orthopaedic Surgeons: Symposium on tendon surgery in the hand. St. Louis: Mosby;1975:70-80.
ReferencesSchuind F, Garcia-Elias M, Cooney WP, An K-N. Flexor tendon forces: In
vivo measurements. J Hand Surg 1980;17A:291-298.Savage R. The influence of wrist position on the minimum force required
for active movement of the interphalangeal joints. J Hand Surg 1988;13B:262-268.
Evans RB, Thompson DE. The application of force to the healing tendon. J Hand Ther 1993;6:266-284.
Lieber RL, Amiel O, Kaufman KR et al. Relationship between joint motion and flexor tendon force in the canine forelimb. J Hand Surg 1996;21A:957-962.
Lieber RL, Silva MJ, Amiel D, Gelberman RH. Wrist and digital joint motion produce unique flexor tendon force and excursion in the canine forelimb. J Biomech 1999;32:175-181.
Goldfarb CA, Harwood F, Silva MJ et al. The effect of variations in applied rehabilitation force on collagen concentration and maturation at the intrasynovial flexor tendon repair site. J Hand Surg 2001;26A:841-846.
References
Boyer MI, Gelberman RH, Burns ME et al. Intrasynovial flexor tendon repair: An experimental study comparing low and high levels of in vivo force during rehabilitation in canines. J Bone Joint Surg 2001;83A:891-899.
Zhao C, Amadio PC, Momose T et al. Effect of synergistic wrist motion on adhesion formation after repair of partial flexor digitorum profundus tendon lacerations in a canine model in vivo. J Bone Joint Surg 2002;84A:78-84.
Amadio PC. Friction of the gliding surface: Implications for tendon surgery and rehabilitation. J Hand Ther 2005;18:112-119.
