Tendon transfer definition types application and disadvantages structures everything for to answer 10 marks question with appropriate illustrative diagrams

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Here is a comprehensive 10-mark answer on Tendon Transfer, fully structured and illustrated.

TENDON TRANSFER

Definition

Tendon transfer is a reconstructive surgical procedure in which a functioning, expendable muscle-tendon unit is detached from its insertion and redirected to restore the lost function of a paralyzed or absent muscle-tendon unit.
"The most common type of reconstructive operation is tendon transfer... Tendon transfer potentially provides earlier improvement in function than nerve repair and may be a better option for some patients' overall rehabilitation." — Rockwood and Green's Fractures in Adults, 10th ed.

Prerequisites / Principles of Tendon Transfer

These are the fundamental "rules" or criteria that must be satisfied before performing a tendon transfer (remember with the mnemonic "SEEMS SAFE"):
PrincipleDetail
Soft tissue equilibriumFull passive range of motion in all joints the transfer will act upon must be present. Contractures must be corrected first.
Expendable donorThe donor muscle must be expendable — usually possible when two or more muscles perform the same movement.
Excursion matchThe transferred muscle must have appropriate amplitude (excursion ≈ ⅓ of fiber resting length). Wrist flexors ~33 mm, finger flexors/extensors ~50–70 mm.
Motor strengthDonor should ideally have MRC grade 5 power; one grade is routinely lost after transfer. Grade 4 donors may still be used.
SynergismSynergistic transfers are easier to re-educate (e.g., wrist flexors used to power finger extension — they normally co-contract).
Single functionOne tendon transfer should perform one function only.
Alignment / straight pullThe line of action should be as straight as possible; angulation reduces mechanical efficiency.
Firm fixationThe tendon is attached end-to-side (preferred) or end-to-end with a Pulvertaft weave — must be strong enough for early mobilization.
Expendable functionTransfer must not sacrifice a critical function at the donor site.
— Miller's Review of Orthopaedics, 9th ed.; Rockwood & Green's Fractures in Adults, 10th ed.

Types of Tendon Transfer

1. Based on Mechanism

TypeDescription
Direct (simple) transferThe tendon is rerouted in a near-straight path to the recipient tendon
Pulley transferThe tendon passes through a pulley (fibrous loop, bone tunnel) to change direction — e.g., opponensplasty via pisiform pulley
Free muscle transferAn entire muscle (e.g., gracilis) is transplanted with microsurgical neurovascular anastomosis — used when no local donor is available

2. Based on Functional Goal

TypeExample
Motor restorationRestore active movement (paralyzed muscle replacement)
TenodesisTendon fixed to bone; passive motion of a proximal joint produces distal joint movement
Static stabilizationPrevent deformity rather than restore movement

Common Clinical Applications

A. Radial Nerve Palsy (High)

Classic "wrist drop" — loss of wrist extension, finger extension, thumb extension.
Function LostDonor TendonRecipient
Wrist extensionPronator teres (PT)ECRB
Finger extensionFCU or FCREDC
Thumb extensionPalmaris longus (PL)EPL
Fig. 1 — Intraoperative view: Tendon transfer for radial nerve palsy FCR → EDC and PL → EPL transfer at the wrist dorsum. Donor tendons woven into recipient tendons using Pulvertaft technique.
Transfer of FCR to EDC and PL to EPL for posterior interosseous nerve palsy — donor tendons woven into recipient tendons on the dorsum of the wrist
Figure 1. Transfer of flexor carpi radialis → extensor digitorum communis and palmaris longus → extensor pollicis longus for reconstruction of posterior interosseous nerve palsy. Multiple sutures lock the weave (A) to restore finger and thumb extension (B). — Rockwood & Green's Fractures in Adults, 10th ed.

Fig. 2 — Intraoperative: Donor tendons (PT, FCU, PL) exposed in distal forearm prior to transfer
Intraoperative view showing donor tendons — pronator teres (PT), flexor carpi ulnaris (FCU), and palmaris longus (PL) — isolated and marked for radial nerve palsy tendon transfer
Figure 2. Three donor tendons (PT radially, PL centrally, FCU ulnarly) mobilized for tendon transfer reconstruction of radial nerve palsy.

Fig. 3 — Postoperative outcomes at 45 days: Grip (b) and finger/thumb extension (c) restored
Postoperative outcome of radial nerve palsy tendon transfer — (a) immediate post-op dorsal forearm incision, (b) active finger flexion at 45 days, (c) active digit and thumb extension restored
Figure 3. (a) Immediate postoperative view. (b–c) At 45 days: active finger flexion and active extension of digits/thumb confirmed — successful tendon transfer for radial nerve palsy.

B. Median Nerve Palsy — Opponensplasty (Low Palsy)

Loss of thumb opposition (thenar wasting). Restoring opposition is the primary goal.
Donor options for opponensplasty:
  • FDS of ring finger (most common) — routed around pisiform pulley
  • EIP (extensor indicis proprius)
  • Abductor digiti minimi (Huber transfer) — for children
  • Palmaris longus with palmaris longus tendon graft
All are inserted into abductor pollicis brevis (APB).

C. Ulnar Nerve Palsy — Anti-Claw Procedure

Loss of intrinsic muscles → claw deformity (hyperextension MCP, flexion IP joints of ring and little fingers).
Goal: Prevent MCP hyperextension = "intrinsic plus" posture.
  • FDSP (lumbrical replacement): FDS of middle/ring finger split and rerouted to lateral bands
  • Brand procedure: ECRB + tendon graft to A1 pulley of ring/little finger
  • EPB rerouting (Bruner): for restoring lateral pinch in thumb adduction weakness

Fig. 4 — EIP to EPL transfer: Intraoperative view (extensor tendon reconstruction)
Intraoperative view of EIP to EPL tendon transfer — EIP harvested at MCP joint dorsum and transferred to repair ruptured EPL tendon
Figure 4. Extensor indicis proprius (EIP) harvested and rerouted to reconstruct a ruptured extensor pollicis longus (EPL) — a common tendon transfer in rheumatoid arthritis.

D. Other Applications

ConditionTransfer
Elbow flexion loss (brachial plexus)Pectoralis major, Steindler flexorplasty (FCR/FCU origin transfer)
Foot dropTibialis posterior to dorsum (through interosseous membrane)
Shoulder abduction lossTrapezius to greater tuberosity
Cerebral palsyFCU → ECRB (wrist extension), various upper limb transfers
PoliomyelitisMultiple as per neurological deficit

Structures Involved

Donor Muscle–Tendon Unit Requirements

  • Must have intact neurovascular supply
  • Adequate muscle fiber length (excursion) and cross-sectional area (force)
  • Rule: Excursion = ~⅓ of resting fiber length
  • Wrist motors: ~33 mm excursion | Finger motors: ~50–70 mm

Common Donor Tendons in the Upper Limb

TendonNerve SupplyNormal ActionUsed For
Pronator teresMedianPronation, weak wrist flexWrist extension (→ECRB)
FCRMedianWrist flexion/radial dev.Finger extension (→EDC)
FCUUlnarWrist flexion/ulnar dev.Finger extension (→EDC)
Palmaris longusMedianWrist flexion (absent 15%)Thumb extension (→EPL), opponensplasty
FDS ringMedianPIP flexion ring fingerOpponensplasty
EIPRadialIndex extensionEPL reconstruction
BrachioradialisRadialElbow flexionThumb flexion (→FPL)

Recipient Structures

  • Paralyzed tendon (preferred — end-to-side anastomosis)
  • Bone tunnel or pulley (for direction change)
  • Lateral band of extensor apparatus

Fixation Methods

  • Pulvertaft weave: Multiple transverse passes + locking sutures — strongest fixation
  • End-to-side: Allows co-contraction if nerve recovery occurs later
  • Bone anchor: For insertional transfers

Disadvantages / Limitations of Tendon Transfer

DisadvantageExplanation
Loss of one MRC gradeTransferred muscle routinely loses ~1 grade of strength after transfer
Donor site morbiditySacrifices a functioning muscle — may weaken original action
Single function onlyOne transfer restores one movement; complex deficits need multiple operations
Re-education requiredPatient must re-learn to use the transferred muscle for its new function (prolonged physiotherapy)
Synergism dependencyNon-synergistic transfers are harder to control and may never be well-coordinated
Not curativeDoes not restore normal anatomy or sensation
Prerequisites strictFails if passive ROM is limited, joints are stiff, or skin/soft tissue is scarred
Risk of over/under-tensionIncorrect tensioning leads to failure — too tight = restricted motion; too loose = no functional gain
Adhesions/scarringTendon may become adherent along its path in scarred tissue
Delayed rehabilitationRequires 6–12 weeks immobilization then months of physiotherapy
Not applicable if no expendable donorIn extensive multi-nerve injuries, no suitable donor may be available — free muscle transfer needed instead

Summary Diagram

TENDON TRANSFER — OVERVIEW
══════════════════════════════════════════════════════
           Paralyzed Muscle (recipient)
                      ↑
    Donor muscle ──────→ Redirected tendon
    (expendable,           (through subcutaneous
     MRC grade 5,          tunnel or pulley)
     synergistic)                 ↓
                      Inserted into recipient
                      tendon (Pulvertaft weave)
                      or bone anchor
══════════════════════════════════════════════════════

PRINCIPLES:  SEEMS SAFE
  S – Soft tissue equilibrium (full passive ROM)
  E – Expendable donor
  E – Excursion match
  M – Motor strength (grade 5 preferred)
  S – Synergistic donor preferred
  S – Single function per transfer
  A – Alignment (straight line of pull)
  F – Firm fixation
  E – Expendable function not sacrificed
══════════════════════════════════════════════════════

Quick Reference — Marking Scheme Structure for 10 Marks

ComponentMarks
Definition1
Principles/prerequisites2
Types1
Applications (with examples — radial, median, ulnar)3
Structures involved (donors, recipients, fixation)1.5
Disadvantages1.5
Total: 10 marks

Sources:
  • Rockwood and Green's Fractures in Adults, 10th ed. 2025 — Chapter 20: Nerve Injuries
  • Miller's Review of Orthopaedics, 9th ed. — Nerve Injuries and Tendon Transfers
  • Current Surgical Therapy, 14th ed. — Muscle and Tendon Transfer ProceduresThis answer covers every component examiners expect for a 10-mark question. Here's a quick orientation:
What's covered:
  1. Definition — precise surgical definition sourced from Rockwood & Green's
  2. Principles — 9 key prerequisites using the SEEMS SAFE mnemonic for easy recall
  3. Types — by mechanism (direct, pulley, free muscle) and by goal (motor, tenodesis, stabilization)
  4. Applications — with full tables for:
    • Radial nerve palsy (wrist drop) — PT→ECRB, FCU→EDC, PL→EPL
    • Median nerve palsy — opponensplasty options (FDS, EIP, ADM, PL)
    • Ulnar nerve palsy — anti-claw procedures
    • Other conditions (foot drop, elbow flexion, CP, polio)
  5. Structures involved — donor tendons table with nerve supply, normal action, and use; fixation methods (Pulvertaft weave, end-to-side, bone anchor)
  6. Disadvantages — 11 specific limitations
  7. 4 intraoperative/postoperative photographs illustrating real surgical scenarios
The mark allocation table at the end maps the answer to the 10-mark rubric so you can allocate writing space in an exam accordingly.

Free flap in orthopaedics Tendon transfer definition types application and disadvantages structures everything for to answer 10 marks question with appropriate illustrative diagrams

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Excellent — I now have all the content and images needed. Here is the full comprehensive 10-mark answer on both topics.

PART 1: FREE FLAP IN ORTHOPAEDICS

Definition

A free flap (free tissue transfer) is a block of tissue — which may include skin, fascia, muscle, bone, or a combination — that is completely detached from its donor site along with its vascular pedicle (artery + vein), then transferred to a distant recipient site where the pedicle vessels are microsurgically anastomosed to local recipient vessels, restoring perfusion to the transplanted tissue.
"A free flap is where a block of tissue is isolated on its pedicle... but at this point, instead of maintaining the pedicle in continuity, it is divided and anastomosed to recipient vessels within the desired location." — Rockwood & Green's Fractures in Adults, 10th ed.

Why Free Flaps in Orthopaedics?

Free flaps are indicated when local and regional flap options are unavailable or insufficient, particularly in:
  • Complex open fractures (Gustilo IIIB/IIIC) with large soft tissue defects
  • Chronic osteomyelitis with dead space and poor local vascularity
  • Post-tumour resection bone/soft tissue gaps
  • Degloving injuries
  • Failed previous local flap coverage
The orthoplastic approach — combined simultaneous management by orthopaedic and plastic surgeons — has become the standard of care. Flap survival is significantly better when reconstruction is performed within 72 hours of injury (Godina's principle, 1986).

Classification / Types of Free Flaps

A. By Tissue Composition

TypeComponentsExample Flaps
FasciocutaneousSkin + fasciaAnterolateral thigh (ALT), radial forearm, SCIP flap
MyocutaneousMuscle + skinLatissimus dorsi, rectus abdominis
Muscle-onlyMuscle (+ skin graft later)Gracilis, rectus abdominis
Osseocutaneous / Vascularized boneBone ± soft tissueFree fibula, iliac crest, scapula
Free functioning muscle transferInnervated muscle for motor functionGracilis (for elbow flexion/finger flexion)

B. By Perforator Pattern

TypeDescription
Axial patternBased on a named artery (e.g., radial forearm — radial artery)
Perforator flapBased on musculocutaneous perforators without sacrificing the parent muscle (e.g., ALT — descending branch of lateral circumflex femoral artery)

Commonly Used Free Flaps in Orthopaedics

1. Anterolateral Thigh (ALT) Flap — Workhorse for lower limb

  • Pedicle: Descending branch of lateral circumflex femoral artery
  • Size: Up to 25 × 35 cm skin paddle; pedicle length 8–12 cm
  • Landmarks: ASIS to lateral border of patella; perforators at midpoint within 4 cm circle
  • Advantages: Large, reliable, thin, pliable; low donor morbidity; simultaneous harvest possible
  • Used for: Gustilo IIIB tibial fracture soft tissue cover

2. Latissimus Dorsi Flap — Largest muscle flap

  • Pedicle: Thoracodorsal artery (branch of subscapular artery)
  • Provides large volume — excellent for filling dead space in osteomyelitis cavities
  • Requires additional skin graft
  • Used for: Open tibial fractures, osteomyelitis, shoulder defects

3. Rectus Abdominis Flap

  • Pedicle: Deep inferior epigastric artery
  • Large muscle, easy harvest
  • Used for: Tibial defects, large soft tissue gaps

4. Gracilis Flap — Free functioning muscle transfer

  • Pedicle: Medial circumflex femoral artery (entering proximal third of muscle)
  • Innervated by anterior branch of obturator nerve → connected to recipient motor nerve
  • Used for: Elbow flexion restoration (brachial plexus injury), finger flexion, facial reanimation
  • Muscle must be placed under proper tension and re-educated

5. Free Fibula Flap — Gold standard vascularized bone graft

  • Pedicle: Peroneal artery (sacrificed — preoperative angiogram mandatory)
  • Harvest: 2 cm distal to fibula neck → 6 cm proximal to lateral malleolus (protect ankle syndesmosis and peroneal nerve)
  • Up to 25 cm of cortical bone available; can carry overlying skin paddle (5 cm width)
  • Used for: Large tibial/femoral bone defects, pathological fractures through osteomyelitis, tumour reconstruction, congenital pseudarthrosis

6. Radial Forearm Flap

  • Pedicle: Radial artery (Allen test mandatory preop to confirm ulnar supply)
  • Thin, pliable, long pedicle, reliable
  • Donor: Skin grafted; visible scar, risk to radial nerve cutaneous branches

7. Scapular / Parascapular Flap

  • Pedicle: Circumflex scapular artery (branch of subscapular artery)
  • Used for: Lateral ankle/foot coverage

8. SCIP (Superficial Circumflex Iliac Artery Perforator) Flap

  • Thin and long; donor scar in groin/lower abdomen — closed primarily for flaps ≤8 cm width
  • Used for: Foot defects (thin, durable coverage)

Structures of a Free Flap

FREE FLAP — COMPONENTS
═══════════════════════════════════════════
  ┌──────────────────────────┐
  │    TISSUE BLOCK          │  ← Skin / Fascia / Muscle / Bone
  │                          │
  │   Feeding ARTERY ────────┼──→ Microsurgical anastomosis
  │   Draining VEIN(S) ──────┼──→   to recipient vessels
  │                          │
  │   (± NERVE) ─────────────┼──→ Coapted for motor/sensory function
  └──────────────────────────┘
        DONOR SITE
        (closed primarily or skin grafted)
═══════════════════════════════════════════
ANASTOMOSIS TYPES:
  • End-to-end (most common)
  • End-to-side (when recipient vessel must be preserved)
Recipient vessels in the lower limb:
  • Posterior tibial artery/vein
  • Anterior tibial artery/vein
  • Peroneal artery/vein

Prerequisites for Free Flap Surgery ("WPES")

RequirementDetail
Well-prepared patientMedically optimized; no inotropic support (causes vasospasm); CT angiogram of limb
Plan B readyIf first flap fails, second option must not be compromised by first
Equipped theatreOperating microscope, microsurgical instruments, experienced scrub team
Safe postoperative monitoringFlap temperature, colour, turgor, Doppler; intensive in first 48–72 hours

Timing of Free Flap

WindowEvidence
< 72 hoursLowest failure rate (Godina 1986)
3–7 days"No man's land" — zone of injury established, local vessels compromised
> 7 daysSignificantly higher failure rates
Current orthoplastic consensus: definitive fixation and flap coverage should be simultaneous or as close together as possible.

Postoperative Monitoring

  • Clinical: colour, turgor, temperature, capillary refill, pin-prick bleeding
  • Handheld Doppler (most common adjunct)
  • Implantable Doppler, laser Doppler, thermography
  • Dangling protocol: progressive limb dependency over 3–5 days to prevent venous congestion
  • Salvageable vascular problems arise mostly in first 24–48 hours; continue monitoring to day 4

Complications / Disadvantages of Free Flaps

ComplicationDetails
Flap failure (partial/complete)Quoted up to 20% in literature — arterial or venous thrombosis
Donor site morbidityScarring, weakness (LD donor: shoulder girdle), vascular sacrifice (radial artery)
Prolonged surgeryOften 6–12+ hours; risk of hypothermia, coagulopathy, deep vein thrombosis
Venous congestionCommonest early complication; treated by re-exploration and thrombectomy
Arterial insufficiencyVasospasm or anastomotic thrombosis → ischaemia
Requires specialist teamNot available in all centres — limits access
Re-exploration riskPatients must consent to potential return to theatre
Donor site healingRadial forearm (visible scar + cold intolerance), ALT (scar, nerve injury)
Complex rehabilitationLengthy bed rest, "dangling" protocol, prolonged physiotherapy
InfectionDespite vascularized tissue, infection remains possible — especially in osteomyelitis beds
Flap bulkMay require secondary thinning/revision surgery

Illustrative Diagrams

Fig. 1 — ALT free flap for Gustilo IIIC open tibia fracture: complete limb salvage sequence (A) Gustilo IIIC open fracture of lower leg with massive soft tissue loss. (B) Post-debridement with plate fixation and ALT free flap harvested. (C) Cross-leg flap pedicle stabilized with external fixator. (D) Patient ambulating with Ilizarov frame. (E) AP radiograph showing bone healing. (F) Long-term functional outcome at 8 years.
Composite clinical series showing Gustilo IIIC open tibial fracture management: (A) massive soft tissue loss, (B) ALT flap harvest post-debridement with plate fixation, (C) cross-leg free flap with external fixator, (D) Ilizarov frame, (E) bone healing X-ray, (F) 8-year outcome with stable limb

Fig. 2 — Free fibula flap for tibial reconstruction: surgical steps and radiograph (A) Marking donor leg. (B) Dissecting down to fibula — superficial peroneal nerve protected. (C) Fibula cut proximally and distally with peroneal pedicle. (D) Flap mobilized. (E) AP X-ray of pathological open tibial fracture through chronic osteomyelitis. (F) Tibial defect with cement spacer. (G) Free fibula graft inset. (H) Final clinical outcome. (I) AP radiograph with fibula in situ.
Free fibula flap for tibial osteomyelitis reconstruction: (A) marking, (B) peroneal nerve-protected dissection, (C-D) fibula isolation, (E-F) tibial defect with cement spacer, (G) fibula inset, (H) healed clinical outcome, (I) AP radiograph

Fig. 3 — Rectus abdominis free muscle flap for open tibial fracture coverage (A: debridement; B: muscle flap; C: skin graft)
Open tibial fracture: (A) soft tissue defect after debridement, (B) rectus abdominis free muscle flap inset with IM nail, (C) split-thickness skin graft over muscle flap

Fig. 4 — Free gracilis muscle flap for open ankle/hindfoot defect, with skin graft coverage
Gracilis free flap for open ankle/hindfoot — left: harvested gracilis muscle belly anastomosed microvascularly; right: healed split-thickness skin graft with external fixator maintaining alignment

Fig. 5 — Double-loop flow-through free flap radiograph with vascular diagram overlay (Posterior tibial, fibular vessels, and descending ramus anastomoses illustrated — red = arterial, blue = venous, green circles = anastomotic sites)
Radiograph of tibial reconstruction with free fibula graft and schematic overlay showing double-loop flow-through flap — posterior tibial artery/vein, fibular vessels, descending ramus, and anastomosis sites


PART 2: TENDON TRANSFER (RECAP + ADDITIONAL DETAIL)

Definition

Tendon transfer is a reconstructive procedure in which a functioning, expendable muscle–tendon unit is detached from its original insertion and redirected to restore the function of a paralyzed or absent muscle.
"Tendon transfer involves transfer of a healthy muscle and tendon to replace the function of a paralyzed muscle." — Rockwood & Green's Fractures in Adults, 10th ed.

Principles — "SEEMS SAFE"

Principle
SSoft tissue equilibrium (full passive ROM must be present)
EExpendable donor (must not sacrifice a critical movement)
EExcursion match (amplitude of donor ≈ that required at recipient)
MMotor strength MRC grade 5 ideal (grade lost after transfer)
SSynergistic muscles preferred (easier re-education)
SSingle function per transfer
AAlignment — straight line of pull
FFirm fixation (Pulvertaft weave — end-to-side preferred)
EExpendable function not compromised at donor site

Types of Tendon Transfer

CategoryTypeExample
By mechanismDirectFCU → EDC
PulleyFDS ring → APB via pisiform pulley (opponensplasty)
Free functioning muscleGracilis for elbow flexion
By purposeMotor restorationParalysed muscle replaced
TenodesisTendon fixed to bone — passive motion drives distal joint
Static stabilizationPrevent deformity

Applications

Radial Nerve Palsy ("Wrist Drop") — Most tested clinically

Function LostDonorRecipient
Wrist extensionPronator teres (PT)ECRB
Finger extensionFCU or FCREDC
Thumb extensionPalmaris longus (PL)EPL

Median Nerve Palsy — Opponensplasty

Goal: Restore thumb opposition (abductor pollicis brevis).
  • FDS ring finger (most common) — via pisiform pulley
  • EIP, ADM (Huber), PL — all into APB

Ulnar Nerve Palsy — Anti-Claw

  • Prevents MCP hyperextension in ring/little fingers
  • Procedures: Brand (ECRB + tendon graft), Zancolli (FDS lasso), Bunnell

Other Applications

ConditionTransfer
Elbow flexion loss (brachial plexus)Steindler flexorplasty / pectoralis transfer
Foot dropTibialis posterior through interosseous membrane to dorsum
Shoulder (axillary nerve)Trapezius to greater tuberosity
Cerebral palsyFCU → ECRB (wrist extension)

Structures Involved

StructureRole
Donor muscle-tendon unitSource of active power
Subcutaneous tunnelRoute of transfer (must be straight)
Pulley or bone tunnelRedirects line of pull
Recipient tendonTarget insertion (Pulvertaft weave or end-to-side)
Bone anchorInsertional transfers
Common donor tendons:
TendonNerveUsed For
Pronator teresMedian→ ECRB (wrist extension)
FCRMedian→ EDC (finger extension)
FCUUlnar→ EDC (finger extension)
Palmaris longusMedian→ EPL / opponensplasty
FDS ringMedian→ APB (opposition)
EIPRadial→ EPL (thumb extension)
BrachioradialisRadial→ FPL (thumb flexion)

Disadvantages

DisadvantageDetail
One MRC grade lostRoutine strength loss after transfer
Donor morbidityWeakens original action
Single function onlyMultiple operations for complex deficits
Re-education requiredProlonged physiotherapy; non-synergistic = harder
Not restorativeNo sensation; not normal anatomy
Strict prerequisitesFails if passive ROM limited, tissue scarred
Tensioning errorsOver/under-tension leads to failure
AdhesionsTendon may stick along its tunnel
Delayed rehab6–12 weeks immobilization then months physiotherapy
No donor availableMay need free functioning muscle transfer instead

Illustrative Diagrams — Tendon Transfer

Fig. 6 — FCR → EDC and PL → EPL for posterior interosseous nerve palsy (Pulvertaft weave at wrist)
Intraoperative transfer of FCR to EDC and PL to EPL — Pulvertaft weave on dorsum of wrist restoring finger and thumb extension in posterior interosseous nerve palsy
Figure 6. FCR woven into EDC and PL woven into EPL with multiple locking sutures (A) restoring finger and thumb extension (B). — Rockwood & Green's Fractures in Adults, 10th ed.

Summary Comparison Table

FeatureFree FlapTendon Transfer
PurposeSoft tissue / bone reconstructionMotor function restoration
IndicationsOpen fractures, osteomyelitis, tumourNerve palsy, paralysis
Vascular requirementMicrosurgical anastomosisNot applicable
Key structurePedicle artery + veinExpendable muscle–tendon
Key complicationFlap failure, venous congestionStrength loss, re-education failure
Specialist requirementMicrovascular surgery, orthoplastic teamHand/reconstructive surgeon
TimingIdeally within 72 hoursAfter nerve recovery plateau (6–12 months)

10-Mark Answer Allocation

ComponentMarks
Free Flap: Definition + classification2
Free Flap: Types with examples (ALT, LD, fibula, gracilis)2
Free Flap: Complications/disadvantages1
Tendon Transfer: Definition + principles2
Tendon Transfer: Applications (radial/median/ulnar)2
Tendon Transfer: Disadvantages1
Total10

Sources:
  • Rockwood and Green's Fractures in Adults, 10th ed. 2025 — Chapter 19 (Soft tissue coverage) & Chapter 20 (Nerve injuries / Tendon transfer)
  • Miller's Review of Orthopaedics, 9th ed. — Nerve injuries and tendon transfers
  • Current Surgical Therapy, 14th ed. — Muscle and tendon transfer
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