What may be assocaited with a blow or fall that has resulted in excessive stretch force that strained the ligamentous tissue?
Fracture, subluxation, or dislocation
Common functional limitations of a sprain:
Interfere with functional use of the hand.
May sublux or dislocate with provoking activities.
From insertion of FDP on the distal phalanx to just distal the FDS insertion on the middle phalanx:
Flexor Zone 1
From distal insertion of the FDS tendon to the level of the distal palmar crease (proximal to neck of metacarpals)
Flexor Zone 2
From neck of the metacarpals, proximally along the metacarpals to the distal border of the carpal tunnel
Flexor Zone 3
Area just proximal to the wrist to the MT junction of the extrinsic flexors in the distal forearm
Flexor Zone 5
From the distal insertion of the FPL on the distal phalanx of the thumb to the neck of the proximal phalanx.
Flexor Zone T1
Injury in Flexor Zone 1:
Only one tendon, FDP, can be severed as can A-4 and A-5 pulleys, which are important for maintaing mechaincial advantage of FDP for complete finger flexion.
Injury in Flexor Zone 2:
FDS and FDP tendons, multiple pulleys (including A-1) of flexor retinaculum. Inability to flex PIP and DIP jts occurs if both are severed. Potential damage to vincula, vascular structures, and supplement nutrition derived from synovial diffusion can compromise tendon healing.
Injury in Flexor Zone 4:
Can affect all three entrinsic flexors of digits: FDS, FDP, FPL-which disrupts finger and thump flexion. Synovial sheath also sustains damage. Nerve injury frequently accompanies laceration in this zone.
Injury in Flexor Zone 5:
Laceration in forearm can cause major damage to flexor tendons of digits and wrist, resulting in loss of wrist and digital flexion. Medial and ulnar nerves and the radial and ulnar arterires also lie superficial in this zone.
Injury to Flexor Zones T1 and T2:
Damage to retinacular pulley system of thumb, synovial sheath in addition to FPL and possibly distal insertion of the FPB can occur. IP and MCP flexion are disrupted.
Why is Flexor Zone 2 so difficult to work with?
Confined space in which extrinsic flexors of fingers lie and limited vascular supply to tendons, healing tissues in this area are prone to excursion-restricting adhesions.
Scar tissue in Flexor Zone 2 can interrupt what?
Tendon gliding in the synovial sheath and subsequently restrict ROM of involved fingers.
What would cause adherence of FDS, FDP, FPL to each other and impairment of differential gliding between the tendons?
Injury to Zone 4
What injury related factors influence the type of surgical repair to manage tendon injury?
Mechanism of injury; type and location of laceration; extent of associated skin, vascular, nerve and skeletal damage; time elapsed.
What surgically related factors influence the type of surgical repair?
time, need for staging surgeries, surgeon's background and experience.
What is a direct repair?
An end-to-end repair in which tendon ends are re-opposed and sutured together.
What is a tendon graft?
Autogenous donor tendon such as PL is sutured in place to preplace the damaged tendon. Necessary when the ends of severed tendons cannot be brought together without undue tension.
Why is the timing so important in tendon repairs?
Severed ends of the tenson begin to soften and deteriorate quickly and proximal portion of tendon retracts.
8 factors that contribute to adhesion formation after tendon injury and repair:
1. Location: higher risk in 2 and 4. 2. Extent: higher risk with extensive trauma. 3. Reduced blood flow. 4. Excessive handling 5. Ineffective suturing 6. Damage or resection of tendon sheath. 7. Prolonged immob. 8. Gapping of repaired tendon ends.
Therapy related factors for postop management
Timing of when therapy is initiated, use of early or delayed mobilization procedures, quality of splinting, expertise of the therapist, quailty and consistency of the patient's involvement in rehab.
Rationale for Early Controlled Motion after a tendon repair.
Decrease postop edema. Maintain tendon gliding. Increases synovial fluid diffusion. Increases wound maturation and tensile strength. Decreases gap formation at repair site.
Indications for use of prolonged immobilization and delayed motion after flexor tendon repair.
Unable to comprehend and actively participate in early: children, diminished cognitive capacity. Unlikely to adhere to program. Repair of other hand injuries or surgeriers necessitates extended immob.
What type of immobilization is used if the motion of the digit is to be delayed for 3-4 weeks?
Cast or static splinting.
Static dorsal blocking splint
Covers dorsal surface of entire hand and distal forearm. Wrist and MCP flexion and IP extension. Restricts wrist and MCP extension. Early phases of rehab.Removed for ex. Protection @ pm.
Dorsal blocking splint with dynamic traction
Allows early motion of jt while hand in splint. Elastic band provides dynamic traction that holds finger in flex. Allows active extension of IP to surface of splint. PIP and DIP extensor relaxation results in passive flex due to elastic band.
Dorsal tenodesis splint with wrist hinge
Worn exclusively for ex. Allows full wrist flex and limited ext. Maintains the MCP in 60 def of flex and IP in full ext. when straps secured.
Typical postion for immobilization for repairs of injuries of zones 1,2, and 3:
Wrist and MCP in flexion; DIP and PIP in extension.
The primary feature that distinguishes an early active motion from an early passive motion approach is:
Use of minimum-tension, active contractions of the repaired MT units during the acute stage of healing.
What is place and hold exercise?
Static muscle contractions to generate active tension of finger flexors and impose controlled stress on repaired tendon. It is an approach to early active motion.
A second approach to early active motion:
Use of dynamic, short arc, minimum mm tension exercises to impose initially low intensity stresses on healing tendon.
Exercises in max protection phase:
PROM, Differential gliding, Place and hold, min tension short arc motion.
How is differential gliding of the FDP and FDS tendons accomplished?
Independent motions of the PIP and DIP joints.
What is the position that needs to be avoided with flexor tendon repairs?
Wrist extension and finger extension
Exercises for min protection phase:
Protective splinting is discontinued, but intermittent splinting may be necessary if the pt has persistent externsor lag or flexion contractures.
Injury to extensor zones 1 and 2
Inability to actively extend the DIP (lag) and evetual DIP flexion contraction and deformity (mallet finger). Swan neck deformity. Usually result in closed rupture.
Injury to extensor zones 3 and 4
Damage to central slip and possibly lateral bands: inability to actively extend the PIP from 90 deg. Flexion contracture and eventually boutonniere deformity.
Injury to extensor zone 5
Damage to EDC, EIP, EDM and sagittal bands that surround the MCP: inability to actively extend the MCP and resulting in MCP contracture.
Injury to extensor zones 6 and 7
juncturae tendium (6) and dorsal retinaculum (7) can be damaged. Bowstring effect occurs. Result in loss of extension of digits and wrist.
Injury to extensor zones T1 and T2
Damage to EPL and EPB leads to loss of hyperextension of IP joints and weakened MCP extension.
Injury to extensor T3 and T4
Damage to EPB leads to weakened MCP ane extension and transfers forces to IP joint leading to a flexion deformity of the MCP joint and hyperextension deformity of the IP joint if EPL is intact.
Laceration and traumatic rupture of the fingers, thumbs or wrist are mor common in the extensor or flexor tendons?
What is the mechanism of mallet finger?
Closed rupture fo the terminal extensor tendon in zone 1 usually from forceful hyperflexion.
Special considerations for extensor zone 1 and 2 tendon repairs
Non op. DIP immob. for up to 8 weeks. Emphasis extension more than flexion.. Splint between exercise sessions.
Special considerations for extensor zone 3 and 4 tendon repairs
If lat. bands intact: DIP AROM 1 wk post op with PIP immob. in extension. Prevents adherence and loss of extensibility. If lat bands damaged: wait 3-4 wks.
Extensor tendon repairs are more prone to gapping and have less tensile strength and are more likely to rupture than flexor tenods after repairs because:
They are morphologically thinner.
With an acute laceration of the PIP joint and middle phalanx, the area must be debrided, cleansed, and treated with antibiotics for what reason?
The wound often enters the joint space.
Why is a K-wire inserted?
if the lateral bands are repaired. Inserted to immobilize the PIP joint in extension for about 3 weeks then removed.
Suturing repairs in zones 3/4 lead to what?
A decrease in overall length of tendon and reduction of flexion.
Why are extensor tendons less likely to retract after laceration or rupture?
Because of the extensor mechanism's multiple ST linkages to surrounding structures.
Why are the attachments of the extensor tendons prone to adhesion formation and loss of excursion during healing?
Due to the ST linkages.
Two general post op rehab after surgical repairs of extensor tendon repairs:
Prolonged uninterrupted immobilization with motion delayed for 3-6 weeks. Controlled passive or active motion initiated during the first few post op days.
What can occur during prolonged immobilization in extensor tendon repair?
Adhesions resulting in marginal outcomes.
Early motion after what type of repair has been shown to be safe and effective?
Primary repair in zones 3 and 7.
What is the most common method of post op immobilization of zones 1 and 2 extensor?
What are the first motions allowed in early motion of extensor tendon repair?
Active flexion with passive extension.
When is a forearm and wrist based or hand base splint indicated?
When there is a need for blocking excessive flexion at the region of the repair.
What splints are worn in delayed motion programs for extensor tendon repairs?
static or bivalved circumferential splint. Dynamic during the day and static at night to protect.
What is the distinguishing feature common to all early active motion programs following extensor tendon repair?
Low intensity and controlled active contractions of the repaired MT units are initiated during the first few postop days, confined to some type of volar splint.
Elements of the early short arc active motion program for central slip repairs include:
Use of customized static volar splints.
Minimum active tension
Enough tension generated during an active muscle contraction to overcome the elastic resistance of an antagonist.
Minimum active tension
Special considerations for ex after extensor tendon repair and extended immob for zones 5 and 6:
Begin active or active assisted MCP ext and passive flexion with wrist and IP jts stabilized in neurtal and forearm pronated. Emphasize active MCP extension more than flex to prevent lag.
Techniques to mobilize the adhesive scar tissue include the application of?
Friction massage directly to the adhesion.