BED SORE (PRESSURE ULCER) - CLASSIFICATION & MANAGEMENT IN PARAPLEGIA

MS Orthopaedics Structured Answer | 5+5 Marks

PART 1 - CLASSIFICATION (5 Marks)

Definition

Pathophysiology (Brief)

1. Pressure (primary) - >32 mmHg for >2 hours causes irreversible ischemia
2. Shear forces - when patient slides down in bed, deeper tissues torn from superficial layers
3. Friction - abrasion of superficial skin
4. Moisture - maceration from urine/sweat (incontinence increases risk ×5)

NPUAP/EPUAP Classification (4-Stage System + 2 Additional Categories)

• Unstageable: Full-thickness loss; base covered by slough/eschar - true depth unknown until debrided
• Deep Tissue Pressure Injury (DTPI): Persistent non-blanchable, deep red/maroon/purple discoloration of intact skin - indicates underlying muscle injury (important in spinal cord injury patients where sensation is absent)

Common Sites in Paraplegia (in order of frequency)

1. Sacrum (most common - ~30%)
2. Ischial tuberosities (especially wheelchair-bound patients)
3. Greater trochanter
4. Heels / calcaneum
5. Lateral malleolus, medial condyle of tibia

Risk Assessment Tools

• Braden Scale - scores 6 domains: sensory perception, moisture, activity, mobility, nutrition, friction/shear (score ≤18 = at risk; ≤9 = very high risk - paraplegics almost always score ≤9)
• Norton Scale - physical/mental condition, activity, mobility, incontinence

PART 2 - MANAGEMENT (5 Marks)

Principles of Management (DIMES Framework)

Debridement | Infection control | Moisture balance | Edge/wound care | Surgery when needed

A. General/Preventive Measures

1. Repositioning every 2 hours - alternating supine, 30-degree lateral tilt positions to offload bony prominences
2. Pressure-relieving devices:
   • Static/alternating air mattresses, gel mattresses, water mattresses (superior efficacy proven)
   • Specialized wheelchair cushions for ischial ulcers
   • Air-fluidized beds and low-air-loss beds for Stage III/IV
   • Avoid: sheepskins, 2-inch foam pads (insufficient pressure reduction)
3. Nutritional optimisation:
   • High protein diet (1.25-1.5 g/kg/day)
   • Vitamin C supplementation (84% reduction in ulcer area shown)
   • Correct hypoalbuminemia (target serum albumin >3.5 g/dL)
   • Zinc, iron supplementation
4. Skin care: Keep skin clean and dry; avoid incontinence contact; avoid therapeutic massage of at-risk areas (causes tissue degeneration); use moisture barriers
5. Multidisciplinary team approach - significant reduction in incidence demonstrated

B. Local Wound Care (by Stage)

C. Debridement Methods

1. Surgical debridement - sharp excision; indicated for infected necrotic tissue threatening septicaemia
2. Mechanical debridement - wet-to-dry saline dressings
3. Enzymatic debridement - topical collagenase; used until wound bed is clean
4. Autolytic debridement - synthetic occlusive dressings allow self-digestion by wound enzymes
5. Biosurgery (maggot therapy) - larvae selectively debride necrotic tissue; option for patients unfit for surgery

D. Infection Control / Antibiotic Therapy

E. Surgical Management

1. Excision of ulcer and underlying bursae
2. Excision of underlying bony prominence (ischiectomy/trochanteric reduction) to reduce recurrence
3. Debridement of osteomyelitic bone if present
4. Flap reconstruction - the definitive surgical option

Note: In paraplegics, muscle flaps are preferred as the denervated muscle provides well-vascularised tissue bulk; sensation is already lost so a sensate flap is not mandatory.

F. Complications to Watch For

• Septicaemia - most serious and common complication; in-hospital mortality 23-36%
• Osteomyelitis - diagnose with MRI/bone biopsy; prolonged antibiotic therapy required
• Cellulitis / necrotising fasciitis
• Amyloidosis - secondary (AA) amyloidosis from chronic infection
• Squamous cell carcinoma (Marjolin's ulcer) - rare malignant change in chronic non-healing ulcers
• Autonomic dysreflexia - triggered by wound pain in high-level spinal cord injury patients; can be life-threatening

Summary Table

TENDON SUTURING TECHNIQUES & PRINCIPLES OF TENDON TRANSFER

MS Orthopaedics Structured Answer

PART 1 - TENDON SUTURING TECHNIQUES

A. General Principles of Tendon Repair

1. Atraumatic handling - minimise crush injury to tendon ends; use sharp instruments
2. Adequate exposure - Brunner zigzag / Bruner incisions to visualise the repair site
3. Tension-free coaptation - ends should be brought together without bunching or gapping
4. Preserve blood supply - avoid excessive dissection around the vincular system
5. Preserve annular pulleys - at minimum A2 and A4 must be maintained to prevent bowstringing
6. Strong repair permitting early mobilisation - four or more strand core sutures allow early active motion, reducing adhesion formation

B. Suture Material

• Core suture: Non-absorbable suture (3-0 or 4-0 Ethibond / Prolene / Nylon)
• Peripheral/epitendinous suture: 5-0 or 6-0 non-absorbable (Prolene/nylon)
• The epitendinous suture contributes up to 50% of load-to-failure strength and reduces bulk at the repair site, minimising triggering

C. Timing of Repair

D. Flexor Tendon Zones (Bunnell's Classification)

E. Core Suture Techniques

1. Bunnell Stitch (Historical - now less preferred)

• Crisscross (zigzag) pattern through tendon substance
• Problem: Jeopardises intratendinous vascularity; strangulates tendon fibres; increased adhesion risk
• Two-strand repair - inadequate strength for early active motion

2. Kessler / Modified Kessler (Tajima) Stitch - Most Widely Used

• Needle enters the cut end of the tendon and exits laterally
• Suture runs longitudinally, then crosses transversely across the cut surface
• Modified Kessler (Tajima) adds a grasping loop at each lateral exit, locking tendon fibres
• Two-strand repair - forms the basis of multi-strand adaptations
• Single knot buried at the repair site

3. Four-Strand Techniques

• Lee technique: Two separate Kessler-type sutures placed 90° apart = four strands cross the repair
• Modified Tsuge: Loop suture looped through each half with a transverse bite; four strands
• Chung (Modified Tsuge): Loop inserted laterally into proximal tendon, run longitudinally across repair, transverse bite in distal half - creates four to six strands
• Advantage: Significantly stronger than two-strand; allows early active mobilisation; reduces gap formation

4. Six-Strand Techniques

• Savage / Adelaide Technique: Three grasping stitches placed sequentially in each tendon end using 4-0 Ethibond, giving six strands crossing the repair
• Grasping stitches placed 5-10 mm from cut end, avoiding the vincular area
• Strongest configuration for active motion protocols

5. Eight-Strand Repairs

• Further modifications of the Savage technique
• Provide maximum tensile strength but technically demanding in the narrow sheath of Zone II

Summary of Strand Strength

F. Epitendinous (Peripheral) Suture - Mandatory Addition

• Placed circumferentially around the repair site after core suture
• Suture material: 5-0 or 6-0 Prolene/nylon
• Functions:
  1. Smooths the repair site, reducing bulk (prevents triggering on pulley)
  2. Adds ~50% of total load-to-failure strength
  3. Resists gap formation significantly
  4. The epitendon-first technique (placing peripheral suture before core suture) has been shown to be 22% stronger than modified Kessler alone
• Types: running horizontal mattress, interlocking mattress (highest load-to-failure), running cross-stitch

G. Extensor Tendon Repair

• Zone 6 (dorsum of hand): Modified Kessler, modified Bunnell, Augmented Becker (MGH technique), or Krackow-Thomas
• MGH (augmented Becker) technique showed superior resistance to gap formation compared to Krackow-Thomas and four-strand Bunnell in cadaveric studies
• Flat, thin extensor tendons in distal zones (I-III) repaired with figure-of-eight or horizontal mattress sutures
• Juncturae tendinum may mask complete tendon division - thorough wound exploration under tourniquet is essential

H. Special Situations

PART 2 - PRINCIPLES OF TENDON TRANSFER

Definition

Campbell's Key Principles (Mnemonic: "ESSEE" or the 7 Principles)

1. EXPENDABILITY

• The donor muscle must be expendable - its transfer must not create an equal or worse deficit
• Restoring finger extension is contraindicated if it sacrifices finger flexion
• Example: Extensor carpi radialis longus (ECRL) is more expendable than ECRB because ECRB is the primary wrist extensor

2. STRENGTH / MUSCLE POWER

• Muscle power graded 0-5 (MRC scale):
  • 0 = No contraction; 1 = Trace; 2 = Active movement without gravity; 3 = Against gravity; 4 = Against gravity and resistance; 5 = Normal
• Donor muscle must be grade 4 or 5 (good to normal)
• A muscle loses one grade of power on transfer - therefore a grade 3 muscle will be useless post-transfer
• Transfer muscle must have adequate physiological cross-sectional area (force = 3.65 × cm² of cross-section)

3. SOFT TISSUE EQUILIBRIUM (Tissue Bed)

• The recipient bed must be pliable, well-vascularised, and free from active infection
• Scarred or fibrotic tissue bed prevents tendon gliding and leads to adhesion formation
• Timing: Transfer is best performed after favorable soft-tissue conditions have been achieved (no swelling, no severe scarring)
• The transferred tendon should be routed subcutaneously whenever possible; passing through tunnels without adequate openings leads to failure

4. SUPPLE JOINTS / PASSIVE RANGE OF MOTION

• Transferred tendon cannot overcome a fixed joint contracture
• Pre-operative requirement: full passive range of motion of all joints across which the transfer will act
• Serial splinting, physiotherapy, or joint releases must precede the transfer if contracture is present

5. EXCURSION / AMPLITUDE

• The tendon must have sufficient amplitude to produce functional joint motion
• Amplitude of common tendons (Curtis):

• Rule of amplitude matching: Transferred tendon amplitude should ideally approximate that of the tendon it replaces
• Amplitude can be augmented by freeing the muscle proximal to its fibrous origin ("amplitude gain")
• The brachioradialis has limited amplitude (short excursion) but can still be useful for selected transfers (e.g., FPL restoration)

6. INTEGRITY / ONE FUNCTION PER TRANSFER

• Each transferred tendon should perform only one function
• When a tendon is split and attached to two points, the muscle acts primarily on the slip under greatest tension - equalising tension at attachment is critical
• Multiple functions overload the donor and compromise the result

7. SYNERGY

• Synergistic muscles are those that normally function together in a coordinated movement pattern
• Example: Wrist flexors and finger extensors act synergistically (wrist flexion automatically extends fingers)
• Transferring a synergistic muscle is technically easier to rehabilitate - the patient can re-educate the transfer more naturally
• Non-synergistic transfers require intensive motor re-education but can still succeed with training

Planning a Tendon Transfer

1. Identify function lost - list the absent motor functions
2. Identify available donors - list expendable muscles with adequate strength and amplitude
3. Match functions to donors - create a table pairing deficits with available muscles
4. Ensure soft-tissue readiness - joints supple, wound healed, oedema resolved
5. Select synergistic donors where possible
6. Route selection - direct (in-line) routing is preferred; subcutaneous tunnels preferred over intermuscular

Common Tendon Transfers (Examples)

Fixation of Transferred Tendon

• Weave-and-sew (Pulvertaft weave) - most common; donor woven through recipient 3-4 times and sutured
• End-to-end anastomosis - when tendons are similar calibre
• Bony attachment - suture anchor or pull-through technique to bone
• Tension setting: Set tension with the wrist and joints in the position that will produce the best functional balance - typically slightly overtightened as some stretch occurs during rehabilitation

Post-Operative Rehabilitation

• Immobilisation phase: 3-4 weeks in protective splint
• Re-education phase: Active motor re-education with physiotherapy starting at 4-6 weeks
• Synergistic transfers can be re-educated more rapidly
• Biofeedback and electrical stimulation may assist re-education of non-synergistic transfers
• Full rehabilitation: 3-6 months

Summary Table