Flexor Tendon Injuries Flashcards
Blood Supply of Hand
The hand is supplied with blood from both ulnar and radial arteries (not great blood supply)
Ulnar and Radial arteries join in 2 arches:
- Superficial Palmar Arch = superficial to flexor tendons
- Deep Palmar Arch = deep to flexor tendons
People have anatomical variations = deep arch can be a little more proximal, surgeon can accidentally hit deep palmar arch = hand will be black and blue
Prefer mini open procedure b/c you know they did a good release
Allen’s test confirms the blood supply integrity
Finger Blood Supply
Neuromuscular bundles
- Contain digital arteries, vein, and nerve
- 2 Bundles: one radial and the other ulnar
Lacerations usually gets vascular bundle
Tendon Nutrition
How does tendon get blood flow, oxygen and other nutrition?
2 Sources:
- Intrinsic: Vascular perfusion (blood supply)
- Extrinsic: Diffusion from synovial fluid (helps them glide freely)
Intrinsic Tendon Nutrition: Vinculi
Vinculi = how tendons and fingers (flexor tendons) get blood
Artery supplies Vinculi and that is how blood is provided to tendons
Also includes thumb (APL and EPB)
Branch off the common digital artery
There is a short vinculum (vinculum brevis) and a long vinculum (vinculum longus) for each FDS and FDP tendon
The vascular supply is mainly on the dorsal side of the tendons
VBP, VLP, VBS, VLS
Extrinsic Tendon Nutrition: Synovial Fluid
Flexor tendons have a synovial sheath in addition of going through a pulley system
Extrinsic nutrition is provided by synovial fluid diffusion = diffusion is accomplished through MOTION
The flexor tendon sheath is a double-walled fibro-osseous tunnel that is sealed at both ends
Synovial fluid bathes the tendon, which provides nutrition and lubrication for low friction glide
Diffusion occurs as the synovial fluid gets pumped into the tendon fibers during flexion and extension of the fingers (hence, movement is important for tendon healing)
*** Tendons are normally immobilized after procedures, this DOES NOT work with hands (kids may be an exception b/c can’t comply)
Immobilization is NOT good for adults and those who can comply (10 and older) b/c it can create adhesions, patients would eventually start to move and tendons would snap
Hand Pulley System
Annular Pulley System:
* 5 Annular pulleys (A1-A5) that hold the tendons close to the bone
If A2 and A4 aren’t there, can’t keep tendon flesh up against the bone
Pulleys improve the biomechanics efficiency of the flexor tendon system
Key pulleys are A2 and A4
Impairment to the pulley system can cause bowstringing
Bowstringing can contribute to reduction in AROM due to changes in the lever arm of the tendon.
Need to know if pulleys are out b/c you will need to support them
Need to know if they have a nerve injury, if so they will need more flexion
New Surgery = WALENT (wide awake surgery on tendons)
allows surgeon to test glide of tendon and teaches AROM b/c it is super strong
CTR = don’t need flexor tendon retinaculum, can cut and won’t bowstring
Thumb Pulley System
3 Thumb Pulleys:
- A1: located at the level of MP joint
- Oblique: located over the middle of the proximal phalanx MOST IMPORTANT PULLEY
- A2: located at the level of IP joint
Camper’s Chiasm
Adhesions can occur here, where FDP comes through FDS
This is in Zone 2
Gliding affect
5 Flexor Tendon Zones
Zone 1
Zone 1: extends from fingertip to mid portion of middle phalanx
FDP is involved thus can’t bend the tip of the finger
Any injury in this area is known as Jersey finger
Can occur during tackle football
Hx of failure to grab an object
Ring finger commonly involved
Painful swollen finger especially of the solar DIP jt
Inability to bend/flex the tip (distal phalanx)
- X-ray (AP, lateral, oblique) to assess for tendinous rupture or bony avulsion fracture
- Surgical repair required
- Swan position dorsal splint and splint inside
- Immobilization 3-4 weeks for younger for younger
- Rosalyn Evans or Indiana Flexor tendon protocol for adults. Surgical repair should be strong
(4-6 strand core stitch)
Flexor Tendon Zone 2
Extends from the mid portion of the middle phalanx (FDS insertion) to the distal palmar crease
Adhesions reduce excursion and results in a stiff finger
Most common area of flexor tendon laceration
Worst prognosis
Area tends to get cut chopping veggies, carving pumpkin, broken glass (lots of chefs)
Terrible results b/c of Camper’s Chiasm
Gliding of these tendons distal, proximal and against each other is imperative to hand function
It can include just FDS or both FDP and FDS depends on how deep it went
Flexor Tendon Zone 3
Extends from the distal palmar crease to the distal portion of the transverse carpal ligament
Not as much scarring in this area
We don’t see a lot of, it is more in traumatic injuries
Flexor Tendon Zone 4
Overlies the transverse carpal ligament
Area does not scar too bad, more tissue there
Flexor Tendon Zone 5
Extends from the wrist crease to the level of the musculotendinous junction of the flexor tendons
Also known as Spaghetti Wrist
Lots of things in zone 5
suicide attempts
have Nn and big arteries
blood flow and nerve fx big issue
Surgical Tendon Repairs
Incisions: Z plasty
Prone to scarring b/c not a lot of tissue
zig-zag preserves length of tissue, will do anytime there is a crease
Primary Repair = best results, less chance for scarring
within the first 2 weeks of tendon
laceration
the optimal time for tendon repair of flexor
tendons is within 24 hours of injury but
definitely within 2 weeks
the longer the severed tendons have to
develop adhesions and scar tissue, the
less the possibility of restoring full fx
atrophy or tendon shortening occurs
Secondary Repair = for lacerations that were not repaired
soon enough
have a worse prognosis b/c the tendon
ends and tendon sheath become
scarred
the musculotendinous units retract
requires tendon graft or 2 stage repair
using Huntington rods
The ideal repair is reliable, does not impair healing and is strong
Can’t do passive extension on a repaired tendon
Repair Strength
The strength of the flexor tendon repair is proportional to the number of core suture strands crossing the repair site
Core sutures bring ends together
Epitendinous suture completes the tendon repair - it helps prevent adhesion formation and triggering by sewing up sheath
Type of suture and type of material used contributes to its strength
6-8 strand core sutures doing well and allow for early active motion inside protective dorsal shell splint
2 strands = 0 wks (2500/ 5.5lbs) 6 wks (2700/5.95lbs)
4 strands = 0 wks (4300/9.5lbs) 6 wks (5200/11.5lbs)
6 strands = 0 wks (6000/13lbs) 6wks (7200/15.8lbs)
*** Repair site loses 50% of its strength at end of week one and then starts rebuilding, 33% @ 3 wks and back up by 6 wks
Patient vulnerable btwn wk 1-3
Most ruptures occur btwn day 10-12
Immobilized tendon is 50% weaker day 5-10 than at day one of repair
Ends of a repaired tendon take about 21 days to stick together
Body breaks down suture material unless it is Kevlar and then it starts to heal
Non-Bulky vs Bulky Repairs
Non-Bulky: old school 2 strand repair
Pro: Passes under pulleys secondary to less bulk
Con: Gaps and is weak - makes tendon longer and does
not pull as hard, not as efficient mechanically
Bulky: 6 strand core - Dr. Strickland
doesn’t pass easily under pulleys normally
new tech to vent pulleys have solved this problem
very strong
allows tenodesis in addition to Duran passive
exercises
3 Main Therapy Approaches to postoperative tendon management
- Controlled mobilization
- Early active mobilization
- Immobilization
Precautions Before Therapy
Instruct the patient to:
- NEVER bend fingers by themselves- only bend them using uninjured hand
- NEVER make a fist with injured hand
- NEVER pick up anything using injured hand
- NEVER straighten fingers using uninjured hand (NO PASSIVE EXTENSION))
Duran Protocol
Day 1 = Dorsal blocking splint
*wrist 20 degrees flexion
* MP joints 60 degrees flexion (in order to
preserve the length)
* IP joints in neutral
*velcro straps are positioned to hold the IP
joints in neutral extension during sleep
Day 3 = The patient is started on protective passive
ROM program
First week = wound is redressed with either xerform or
adaptive and 1 inch guaze wrap
usually perform 2 days and the switch to
adaptic
coban could cause too much traction
always check capillary refill when putting
dressing on
Controlled Mobilization
First week
The splint must allow full IP extension
can’t be curved downward b/c they could get PIP flexor contracture
Bulky surgical dressing is removed carefully adhering to protective motion precautions
Controlled Mobilization
First 4 Weeks
Patient begins active extension within the confines of the dorsal blocking splint
The patient performs passive PIP and DIP movement within the splint one joint at a time
Must be gentle
Goal = PROM to proximal palmar crease in 2-3 wks
swelling and dressing can create drag on the tendon, must use clinical judgement
After 2 wks:
sutures are removed
Scar massage can be initiated but finger must be kept in protective position - scar massage has to be inside splint
After 4 wks:
dorsal splint may be removed and gentle composite ROM can be performed
wrist ROM and tendon gliding can be initiated
continue with PROM
continue to use a static dorsal-blocking splint btwn exercises and at night for 1 more week
6 weeks:
discontinue splint
no gripping anything heavier than a toothbrush
do not push or pull anything w/ injured hand
don’t lift any heavy objects
8 wks:
light strengthening exercises such as squeezing a sponge or nerf ball can be initiated
PROM in extension can be performed if there is a deficit
10 wks:
moderate strengthening exercises are begun
12 wks:
patient resumes normal activities
Early Active Mobilization
Used with 4-strand repairs and greater
Tendon gliding is elicited by active contraction of the injured muscle using tenodesis exercises (Indiana Flexor Tendon Protocol)
Don’t do place and hold - when you activate the hold it pulls hard on repair and can cause gapping
Immobilization
Complete immobilization for 4 wks following a tendon rupture
Used with young patients (younger than 10 yrs)
Cognitive deficit
Non-compliant patients
Greater incidence of tendon rupture b/c tendon gains tensile strength when repair site is submitted to gentle tension
Has not resulted in consistently good results
scar and get adhesions
Complications
1) Adhesion formation:
* most common complication
* causes stiff joints
Factors that promote adhesions
- trauma to the tendon and sheath
- tendon ischemia
- digital immobilization
- prolonged edema
Factors that suppress adhesion formation
- good surgical technique
- tendon mobilization early
- motion between the tendon and its sheath
2) Rupture of the tendon repair
* most common btwn the 7th and 10th postoperative day
* must refer back to surgeon as soon as possible
* huge complication, must get back to dr asap
3) Flexor contractures of PIP joints
* dorsal strap in extension to shell at night
* might require a solar gutter component
4) injury to neuromuscular structures
5) hypersensitivity - on flexor side of hand
6) complex regional pain syndrome
7) Bowstringing of the tendon
8) Infection
