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- PTTD most common (May be secondary to RA)
- trauma
- inflammatory
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- Idiopathic
- Vertical talus
- Calcaneovalgus (L5 myelodysplasia)
- Tarsal coalition
- Acccessory navicular
- Cerebral palsy diplegic type (hemiplegic causes pes cavovarus)
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- Main attachment is over the navicular
- With several secondary attachments - lateral cuneiform, medial cuneiforms and the metatarsal bases, cuboidhttps://jfootankleres.biomedcentral.com/articles/10.1186/s13047-020-00392-1
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- Antagonist of PTT = Peroneus Brevis
- Strong PB and weak PT will lead to the foot being abducted ➔ talonavicular uncoverage the too many toes sign.
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- Water shed area 2-6cm from attachment ➔ risk of tendon dengeration ➔ incompentence
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- Degeneration ➔ Tenosynovitis ➔ Medial ligaments strain ➔ bony deformity
- Tendon degeneration occurs in watershed region distal to medial malleolus
- Begins as tenosynovitis and becomes painful tendon that lacks excursion
- Unable to fulfill role as midfoot inverter to lock transverse tarsal joint for toe off ➔ leading to stresses on medial ligaments ➔ Spring ligamemnt
- ➔ Unopposed action of the Peroneus brevis pulls the forefoot into abduction
- ➔ Achilles tendon now becomes a everter of the heel causing worsening valgus deformity.
- Bony deformities occur at later stage
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- Posterior tibial tendon acts in inverter of the transverse tarsal joint, locking it to become a stiff lever arm, allowing efficient toe off
- TN and CC joints (transverse tarsal joint aka chopart joint)
- When in eversion (at rest), axes of both joints are parallel and joint is relaxed
- Foot is mobile and can adapt to uneven ground
- When in inversion (by action of Post tib), axes diverge and joint is locked
- Becomes a stiff lever arm for push off
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- Hx = trauma, inflammatory arthritis, symptoms, lateral impingement, pain
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- Pain over lateral malleolus ➔ due to lateral ankle impingement [Subfibular impinvement]
- Inspect - too many toes, valgus hindfoot, supinated forefoot, callus, foot wear
- Gait
- Single leg calf raise - if unable = Stage 2 PTTD
- Jack's test = flexible? If not correctable = Stage 3/4
- Dorsiflex big toe should cause medial arch to elevate due to windlass effect if subtalar joint is flexible
- Silverskoid test - all FA conditions
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- Lateral XR
- Calcaneal pitch [17-30 degrees]
- Angle between line drawn through longitudinal axis of talus and 1st MT
- [Cavus] Sinus Tarsi see through sign
- AP XR [Planus only]
- 1 line drawn connecting talus articular surface; another line connecting edge of navicular articular surface. Angle between
- Described as percentage
- OR talonavicular angle [< 7 deg]
- Angle between lines drawn down the axis of the talus and calcaneus measured on a weight-bearing DP foot radiograph
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- † + Myerson added 4th stage
- Stage 1 = NO DEFORMITY. Single leg raise OK.
- Stage 2 = DEFORMITY PRESENT [Flexible deformity].May or may not be able to do a single leg raise. (may be weak) - Jacks test +ve
- 2A = TN uncoverage < 40%
- 2B = TN uncoverage > 40% (forefoot abduction)
- 3 = + Subtalar Arthritis [rigid deformity - Jack's test -ve]
- 4 = + Tibiotalar arthritis (tilting talus) (rigid)
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- 28. Orthotics
- UCBL - university of california Berkley
- The UCBL (University of California Berkeley Laboratories) orthosis is a rigid plastic insert designed to control severe hindfoot valgus and midfoot pronation (used in posterior tibial tendon dysfunction)
- It is a corrective orthosis
- It maintains the hindfoot in neutral position by locking the transverse tarsal joints and limiting pronation (effectively replacing the function of the posterior tibial tendon in locking the transverse tarsal joint)
- Medial posting insoles ➔ to correct valgus hindfoot, to correct line of pull of achilles tendon to prevent it from worsening valgus deformity
- Calf stretching ➔ every foot and ankle pathology has issue with gastrocnemius
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- Goals = PPPSS (painless, plantigrade, pliable, Shoeable, Stable)
- Can be divided into soft tissue and bony procedures. "Typically for soft tissue, I will do a FDL to Medial cuneiform transfer, and a gastroc release, spring ligament recon. Bony procedures wise I will do a MCO if it is insufficient, I may consider a cotton's osteotomy or a lateral column lengthening osteotomy
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- Tendon transfer – FDL to Medial cuneiform OR Cobb's procedure (use of Anterior tibialis tendon **Do not mention this for FRCS)
- Spring ligament reconstruction (autograft, allograft, synthetic Internal brace)
- (If Silverskoid +ve) Gastroc release, Tendoachilles Lengthening (tight gastroc worsens hindfoot valgus moment forces)
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- MCO = Medializing calcaneum osteotomy ➔ changes vector of achilles tendon.
- If still not enough ➔ Lateral column lengthening osteotomy [Evan's Osteotomy] –through the calcaneum
- Cotton’s Osteotomy – Medial cuneiform dorsal opening osteotomy to correct forefoot
- Arthroreisis screw “subtalar stenting” – controversial
- SOA Inderjit Singh = For 2B he use 4 procedures - Tendoachilles Lengthening, MCO, FDL transfer, LCLO
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- Henry’s knot – FDL is superficial at the knot
- Harvest more proximal to the Henry's knot
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- No, there are a number of fibrous interconnections between the 2 tendons
- So flexion of digits can still continue after harvet of either FDL or FHL
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- It is synergistic with the PTT and is easily accessible.
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- FDL to medial cuneiform
- Cobb's procedure ➔ partial Anterior Tibial Tendon graft rerouted through the 1st cuneiform
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- Proximal vs Distal
- Distal - e.g. Strayer
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- Distal section involves the gastroc tendon and aponeurosis of soleus, may be hard to separate. So distal section is not always pure gastroc lengthening
- Distal section can lead to interruption of muscle continuity ➔ leads to weakness
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- Prone position
- Posterio medial transverse incision made on or just below the posterior knee crease
- Crural fascia is divided longitudinally and proximal insertion of medial gastroc is identified
- Section the white fibers of the medial gastroc
- Post op - no immobilization required. FWBAT
- barouk2014.pdf
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- If it is rigid, this is an indication for fusion surgery
- I will assess which joints are affected - Typically, subtalar joints (TN, TC, CC)
- I will fuse them accordingly.
- Talonavicular, Subtalar fusion, +/- calcaneocuboid fusion (If all 3 = triple arthrodesis) [i.e. subtalar joint and chopart/ transverse tarsal joint)
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- In stage 4, the tibio talar joint is also affected (stage 4), pantalar fusion is an option however, aware it has poor outcomes. I will consider
- Talectomy and Tibiocalcaneal fusion (for very contracted skin in RA and poor skin) OR
- Tibio-Talo-Calcaneal fusion (TTC)
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- Overcorrection – leads to lateral overloading