High Yield Overview

PERONEAL TENDON REPAIR/RECONSTRUCTION

Direct posterolateral approach to fibula along course of peroneal tendons | advanced

Critical Danger Structures - SPECIFIC ANATOMICAL LOCATIONS

Sural Nerve

Location: Runs with lesser saphenous vein in subcutaneous tissue, 1-2cm POSTERIOR to lateral malleolus

Protection: Identify early during superficial dissection, tag with vessel loop, retract posteriorly throughout case

Lateral Calcaneal Sensory Branches

Location: Branch from sural nerve approximately 6-8cm proximal to lateral malleolus, course toward heel

Protection: Preserve during subcutaneous dissection, gentle retraction if encountered

Calcaneofibular Ligament (CFL)

Location: Deep to peroneal tendons, runs from fibular tip to lateral calcaneus at 45-degree angle

Protection: Avoid excessive dissection anterior to tendons, preserve during SPR reconstruction and groove deepening

Peroneal Artery

Location: Lies deep to peroneal tendons in posterior compartment, approximately 2-3cm anterior to fibula at proximal exposure

Protection: Limit deep dissection anterior to tendons, stay within tendon sheath plane

Fibular Posterior Cortex

Location: Thin posterior cortical wall of distal fibula - can be violated during aggressive groove deepening

Protection: Deepening to 4-5mm only, avoid penetrating anterior cortex, preserve structural integrity

Mnemonic

BREVISBREVIS - Longitudinal Split Tear Assessment

Mnemonic

SURALSURAL - Protecting the Sural Nerve

Indications

Primary Indications for Peroneal Tendon Surgery

Tendon Tears:

Peroneal brevis longitudinal split tears with >50% tendon involvement
Complete or partial rupture of peroneal brevis or longus
Failed conservative management (3-6 months) for symptomatic tears
Acute complete ruptures in young athletic patients

Peroneal Subluxation/Dislocation:

Symptomatic peroneal tendon subluxation/dislocation
Superior Peroneal Retinaculum (SPR) insufficiency or rupture
Shallow fibular groove (<2mm depth) with recurrent subluxation
Failed conservative management with bracing/physical therapy

Combined Pathology:

Peroneal tendinosis with >50% tendon degeneration requiring debridement
Concurrent lateral ankle instability requiring combined reconstruction
Os peroneum fracture with peroneus longus rupture
Revision cases after failed prior repair

Contraindications:

Active infection
Severe peripheral vascular disease
Inadequate soft tissue envelope
Medical comorbidities precluding surgery
Patient unwilling to comply with postoperative restrictions

Preoperative Planning

Clinical Assessment:

History: Lateral ankle pain, weakness, sensation of snapping/popping with activity
Mechanism: Acute dorsiflexion/eversion injury (subluxation) vs chronic repetitive microtrauma (tears)
Physical exam: Palpate tendons for subluxation (reproduce with active eversion/dorsiflexion), tenderness at fibular tip, lateral ankle stability testing (anterior drawer, talar tilt)

Imaging:

Radiographs: AP, lateral, mortise views - assess for os peroneum, shallow fibular groove, ankle arthritis
MRI: ESSENTIAL for surgical planning - identify tear pattern (longitudinal vs rupture), degree of tendinosis, SPR status, fibular groove morphology, measure tendon quality/cross-sectional area
Ultrasound: Dynamic assessment of subluxation if available

Surgical Planning:

Determine repair vs reconstruction based on MRI (>50% involvement = augmentation)
Assess for concurrent lateral ankle instability (combined procedure)
Identify tear location (fibular tip vs os peroneum vs cuboid tunnel)
Plan for FDL harvest if reconstruction likely
Consent for possible allograft if tissue inadequate

Patient Counseling:

Success rate 85-90% for repairs, 80-85% for subluxation reconstruction
Sural nerve numbness risk 5-15%
Return to sport 4-6 months
Immobilization and restricted weight-bearing requirements

Step-by-Step Operative Technique

Step 1: Incision and Superficial Dissection

Technique:

Make longitudinal incision 10-12cm, centered over lateral malleolus, extending 6cm proximal to 4-6cm distal
Position incision slightly posterior to fibular tip, directly over palpable peroneal tendons
Sharpen skin incision with scalpel
Careful subcutaneous dissection to identify and protect sural nerve

Critical Anatomy: Sural nerve runs with lesser saphenous vein in subcutaneous tissue, 1-2cm posterior to lateral malleolus

Exam Pearl

Sural Nerve Protection: The sural nerve is the MOST COMMON structure injured in this procedure (5-15% incidence). Identify it early by finding the lesser saphenous vein and dissecting carefully around it. Tag the nerve with a vessel loop and maintain gentle posterior retraction throughout the case. The nerve has variable anatomy - may be multiple branches. Lateral calcaneal branches course toward the heel and must be preserved.

Dangers at this step

Sural nerve injury causing lateral foot numbness and painful neuroma (most common complication)
Lateral calcaneal branch injury causing heel numbness
Inadequate incision length limiting exposure for tendon work
Incision too anterior (over fibula) or too posterior (missing tendons)

Step 2: Superior Peroneal Retinaculum (SPR) Exposure

Technique:

Identify SPR as fibrous band 2-4cm proximal to fibular tip
Assess SPR integrity: intact, attenuated (Grade 1), partial tear (Grade 2), or complete tear (Grade 3)
If torn, identify tear pattern: fibular avulsion (most common 85%), calcaneal avulsion, or midsubstance
Tag torn SPR edges with sutures for later repair
In subluxation cases, tendons may sublux anterior to fibula with ankle manipulation

Exam Pearl

SPR Tear Patterns: The SPR is the PRIMARY restraint to peroneal subluxation. It most commonly tears from its fibular insertion (85%) due to the force vector during subluxation. Less commonly, it tears from the calcaneal insertion or in the midsubstance. Complete tears (Grade 3) require reconstruction - simple repair of attenuated tissue will fail. Remember to assess the fibular groove depth as well - shallow groove (<2mm) may require groove deepening in addition to SPR repair.

Dangers at this step

Not recognizing SPR tear pattern leading to inadequate repair selection
Iatrogenic injury to intact SPR if not carefully dissected
Missing shallow fibular groove (SPR repair alone will fail if groove inadequate)
Over-aggressive dissection damaging local tissue needed for augmentation

Step 3: Peroneal Tendon Sheath Opening

Technique:

Incise peroneal tendon sheath longitudinally from proximal to distal
Open sheath widely to fully expose both brevis and longus tendons
Perform synovectomy of inflamed synovium to improve visualization
Inspect tendons throughout entire exposed length
Identify both tendons: brevis is ANTERIOR and SUPERFICIAL, longus is POSTERIOR and DEEP

Exam Pearl

Tendon Identification: Critical to correctly identify brevis vs longus. Brevis is ANTERIOR (closer to fibula) and SUPERFICIAL, inserts at base of 5th metatarsal. Longus is POSTERIOR (toward Achilles) and DEEP, courses plantar under foot. To confirm: trace distally - brevis stays superficial to 5th MT, longus dives plantar at cuboid. Proximally, brevis originates on distal fibula, longus on proximal fibula. Most tears are in brevis.

Dangers at this step

Confusing brevis and longus leading to wrong tendon being treated
Incomplete sheath opening missing proximal or distal extent of tear
Excessive synovectomy causing postoperative adhesions
Not opening sheath distally enough to assess full tear extent

Step 4: Tendon Tear Assessment

Technique:

Systematically inspect both tendons for tears
Identify tear pattern:
- Longitudinal split (most common in brevis, appears like split book pages)
- Complete rupture with gap
- Partial tear with >50% cross-section involved
Assess tendon quality: good tissue (pink, firm, normal caliber) vs poor tissue (grey, friable, thin, degenerative)
Measure extent: <50% = primary repair, >50% = augmentation needed
Debride degenerative tissue back to healthy bleeding tendon edges

Exam Pearl

Decision Making - Repair vs Reconstruction: The critical threshold is 50% tendon involvement. Less than 50% with good tissue quality can be tubularized with primary repair. More than 50% involvement, poor tissue quality, or complete rupture requires augmentation (FDL transfer preferred) or allograft. Don't attempt primary repair of >50% tears - high failure rate. FDL transfer is the GOLD STANDARD for reconstruction with 85-90% success rate.

Dangers at this step

Underestimating tear extent leading to inadequate debridement and repair failure
Over-debriding creating a larger defect than necessary
Missing tear in the second tendon (both can be injured)
Not identifying longitudinal splits that appear subtle but extend significantly

Step 5: Primary Repair (if <50% involvement, good tissue)

Technique:

For tears involving <50% of tendon cross-section with good tissue quality
Tubularize the longitudinal split with side-to-side repair
Use 2-0 or 3-0 absorbable suture (Vicryl or similar)
Running locked stitch technique (Krackow or baseball stitch)
Repair entire length of split, typically 4-6cm
Maintain normal tendon tension (compare to intact longus if available)
Create smooth tubular contour without bunching or gaps
Test gliding in fibular groove - should move smoothly without catching

Exam Pearl

Tubularization Technique: Goal is to restore the normal tubular shape and tensile strength. Use a running locked stitch (Krackow provides best strength, baseball stitch easier/faster). Avoid over-tightening which restricts motion and creates a bulky repair that catches in the groove. Avoid under-tensioning which leaves gaps that fail. The repaired tendon should be slightly thinner than the original due to loss of degenerate tissue. Test gliding before proceeding - if it catches, the repair is too bulky.

Dangers at this step

Over-tightening creating a tendon that's too short and restricted motion
Under-tensioning leaving gaps that will fail under load
Repair too bulky causing impingement and pain in fibular groove
Attempting primary repair when >50% involved (will fail - need augmentation)

Step 6: FDL Transfer for Augmentation (if >50% involvement)

Technique:

For tears >50% cross-section, poor tissue quality, or complete rupture
Make separate 3-4cm medial incision posterior to medial malleolus
Identify neurovascular bundle (protect posterior tibial nerve and artery)
Identify FDL tendon (posterior to FHL, anterior to Achilles)
Harvest FDL with adequate length (divide distally, retrieve proximally)
Return to lateral side
Create bone tunnel in distal fibula (5mm drill, posterior to lateral malleolus) OR use 3.0-3.5mm suture anchor
Weave FDL through/around remaining peroneal tendon tissue
Pass FDL through bone tunnel or secure with anchor
Tension FDL to restore eversion strength (compare to contralateral)
Tenodese FDL to remaining peroneal tissue with multiple interrupted sutures
Test eversion strength and gliding before proceeding

Exam Pearl

FDL Transfer - Gold Standard: FDL transfer is preferred over allograft because it's autologous, strong, and motor function is preserved (FHL compensates for FDL loss at the toes - patients don't notice functional deficit). Technique: weave FDL through remaining peroneal tissue to maximize contact surface area, then anchor to distal fibula with bone tunnel or suture anchor. Tension with ankle in neutral - too tight restricts motion, too loose weak eversion. Success rate 85-90%. Alternative: peroneus longus to brevis transfer if longus intact and brevis destroyed.

Dangers at this step

Inadequate FDL harvest length requiring excessive tension or inability to complete reconstruction
Injury to posterior tibial neurovascular bundle on medial side (devastating complication)
FDL transfer too tight causing restricted ankle motion and pain
FDL transfer too loose providing inadequate eversion strength
Anchor or bone tunnel pullout due to poor fixation or osteoporotic bone

Step 7: Fibular Groove Deepening (if shallow groove)

Technique:

Assess fibular groove depth (normal >2mm, shallow <2mm)
If shallow: deepen groove to improve tendon tracking and prevent impingement
Use curved osteotome or burr to remove posterolateral bony ridge
Create U-shaped groove 4-5mm deep, 8-10mm wide
Smooth all sharp edges with rongeur or burr
Avoid penetrating anterior cortex
Copiously irrigate to remove bone debris
Reassess tendon tracking in deepened groove

Exam Pearl

Groove Deepening Controversy: Shallow fibular groove (<2mm) is a predisposing factor for both subluxation and brevis tears (impingement on posterolateral ridge). Deepening the groove removes the impingement point and improves tracking. However, aggressive deepening risks fibular fracture (rare but reported). Many surgeons prefer SPR reconstruction over groove deepening due to fracture risk. If performing groove deepening, limit depth to 4-5mm maximum and preserve anterior cortex. Alternative: use groove deepening in combination with SPR reconstruction for severe cases.

Dangers at this step

Fibular fracture from over-aggressive deepening (rare <1% but catastrophic)
Penetrating anterior fibular cortex violating ankle joint
Creating groove too wide, weakening fibula and destabilizing CFL attachment
Not removing enough bone leaving persistent shallow groove and impingement
Thermal injury from burr (use irrigation, intermittent contact)

Step 8: Superior Peroneal Retinaculum Reconstruction

Technique:

For Grade 3 SPR tears (complete rupture) or Grade 2 with poor tissue
Direct Repair Technique (most common):
- Place 1-2 suture anchors (3.0mm) at posterior fibular insertion site
- Pass sutures through torn SPR tissue
- Tie with ankle in neutral, slight eversion
- Alternatively: drill transosseous tunnels through fibula, pass sutures
SPR Augmentation Technique (for poor tissue quality):
- Use local tissue (strip of Achilles sheath or peroneal sheath)
- Weave augmentation through native SPR
- Secure to fibula and calcaneus
Bone Block Technique (less common):
- Create fibular bone flap (posterior cortex)
- Elevate and rotate over tendons
- Secure with screw
Test stability: tendons should remain posterior to fibula through dorsiflexion/eversion

Exam Pearl

SPR Reconstruction Technique Selection: Direct repair with suture anchors is most common and effective for acute tears with good tissue. Transosseous sutures through drill holes are traditional alternative (cheaper, no hardware). SPR augmentation needed for chronic tears with attenuated, poor-quality tissue. Bone block technique rarely used now due to complexity and hardware issues. Key: tension the SPR with ankle in neutral and slight eversion - over-tightening restricts eversion and causes pain, under-tightening allows persistent subluxation.

Dangers at this step

SPR repair too tight restricting eversion and causing lateral pain
SPR repair too loose allowing recurrent subluxation (10-15% failure rate)
Suture anchor penetration through anterior fibular cortex
Not addressing shallow groove (SPR repair alone may fail if groove <2mm)
Anchor pullout in osteoporotic bone

Step 9: Intraoperative Testing

Technique:

Before closure, perform comprehensive testing:
- Gliding test: Plantarflex and dorsiflex ankle, evert foot - tendons should glide smoothly without catching or bunching
- Stability test: Dorsiflex and evert ankle - tendons should remain posterior to fibula, no subluxation
- Strength test: Manually resist eversion - should have good strength, compare to contralateral
- ROM test: Full ankle dorsiflexion, plantarflexion, inversion, eversion - no restriction or pain
If subluxation persists, revise SPR or consider groove deepening
If gliding restricted, check for repair too bulky or over-tight
If weak eversion, check FDL transfer tension

Exam Pearl

Importance of Intraoperative Testing: Testing before closure is ESSENTIAL to identify problems that can be immediately corrected. Persistent subluxation indicates inadequate SPR reconstruction or shallow groove requiring revision. Restricted gliding suggests repair too bulky or tight requiring revision. Weak eversion suggests FDL transfer too loose or inadequate fixation. Testing under anesthesia may give false reassurance - some problems only apparent when patient awake, but major issues should be evident intraoperatively.

Dangers at this step

Missing persistent subluxation leading to early failure
Not recognizing over-constraint causing postoperative stiffness and pain
False reassurance from testing under anesthesia (muscle relaxation)
Not testing full ROM and strength adequately

Step 10: Closure and Postoperative Immobilization

Technique:

Close tendon sheath loosely with absorbable suture (3-0 Vicryl, simple interrupted)
Avoid tight sheath closure (causes adhesions and restricted gliding)
Close subcutaneous tissue with absorbable suture (3-0 Vicryl)
Skin closure with nylon interrupted or subcuticular absorbable
Drain placement optional (if significant bleeding risk or dead space)
Apply well-padded short leg splint with ankle in neutral, slight eversion
Compression dressing

Exam Pearl

Immobilization Position: Position ankle in NEUTRAL with SLIGHT EVERSION to protect the repair. Excessive plantarflexion or eversion can overload repair. Excessive dorsiflexion or inversion can stress the repair. Neutral with slight eversion is optimal. NWB for 2 weeks for wound healing. Then WBAT in CAM boot for total of 6 weeks immobilization to protect tendon healing (tendon healing takes 6-8 weeks).

Dangers at this step

Tight sheath closure causing adhesions and stiffness
Inadequate skin closure leading to wound dehiscence
Splint too tight causing compartment syndrome or pressure sores
Splint in wrong position (excessive plantarflexion or dorsiflexion) stressing repair

Complications - Comprehensive Management

Major Complications: Recognition, Prevention, and Management

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

EXAMINER

"A 32-year-old basketball player presents with lateral ankle pain and recurrent popping sensation. Describe your diagnostic approach and how you would decide between repair versus reconstruction."

EXCEPTIONAL ANSWER

This presentation is classic for peroneal pathology with possible subluxation. My diagnostic approach would be systematic. First, history: I would ask about mechanism - acute inversion injury with pop suggests SPR rupture and subluxation, while chronic lateral pain suggests peroneal tendinopathy or tears. I'd ask if they feel snapping or popping with eversion and dorsiflexion - this is pathognomonic for subluxation. On examination, I would palpate the peroneal tendons along the fibular groove, checking for tenderness, swelling, or palpable subluxation. I would perform the peroneal subluxation test - active dorsiflexion and eversion while palpating the tendons - feeling for subluxation anterior to the fibula. I'd also assess lateral ankle stability with anterior drawer and talar tilt tests, as 30-50% have concurrent instability. For imaging, AP, lateral, and mortise radiographs to assess for os peroneum, shallow fibular groove, or ankle arthritis. MRI is essential for surgical planning - it identifies tear pattern (longitudinal split vs rupture), degree of tendon involvement (critical for determining repair vs reconstruction), tendinosis severity, SPR integrity, and fibular groove morphology. The decision between repair and reconstruction depends primarily on the extent of tendon involvement and tissue quality. Primary repair is appropriate when less than 50% of the tendon cross-section is involved and tissue quality is good - the tendon appears pink, firm, and of normal caliber. In this scenario, tubularization with side-to-side repair using running locked stitch provides excellent results. However, reconstruction with FDL transfer is required when more than 50% of the tendon is involved, when tissue quality is poor - appearing grey, friable, or attenuated - or when there is complete rupture with inadequate tissue for primary repair. The FDL transfer is the gold standard for reconstruction with 85-90% success rates. If subluxation is the primary issue, I would focus on SPR reconstruction with direct repair using suture anchors, and consider groove deepening if the fibular groove is shallow (less than 2mm depth on MRI).

VIVA SCENARIOStandard

EXAMINER

"You're performing peroneal tendon repair and identify a longitudinal split tear involving 60% of the peroneus brevis. Walk me through your surgical management and technical decision-making."

EXCEPTIONAL ANSWER

A 60% longitudinal split exceeds the threshold for primary repair and requires augmentation. First, I would fully assess the extent of the tear by opening the tendon sheath from proximal to distal, typically 10-12cm, and performing synovectomy to improve visualization. I would confirm that the tear involves more than 50% of the cross-section - measuring the width of the tear compared to the intact portion. I would assess tissue quality by inspecting color (healthy is pink, degenerate is grey), consistency (healthy is firm, degenerate is friable), and caliber. I would also check the peroneus longus for tears, as both tendons can be injured. Given the 60% involvement, I would proceed with FDL transfer for augmentation - this is the gold standard reconstruction. My technique would be: First, debride the brevis back to healthy bleeding tissue edges - removing all grey, degenerate tissue. Then, make a separate 3-4cm medial incision posterior to the medial malleolus to harvest the FDL. I would carefully identify the neurovascular bundle (posterior tibial nerve and artery) and protect it. The FDL is posterior to the FHL and anterior to the Achilles - I would identify it based on these landmarks. I would harvest the FDL with adequate length by dividing it distally and retrieving it proximally. Back on the lateral side, I would prepare for reconstruction. I have two main options for fixation: create a 5mm bone tunnel in the distal fibula posterior to the lateral malleolus, or use a 3.0-3.5mm suture anchor. I would weave the FDL through and around the remaining healthy peroneal brevis tissue to maximize contact surface area. Then pass the FDL through the bone tunnel or secure it with the suture anchor. Critical step: I would tension the FDL with the ankle in neutral position, comparing eversion strength to the contralateral side - too tight restricts motion, too loose provides weak eversion. I would tenodese the FDL to the remaining peroneal tissue with multiple interrupted sutures using 2-0 absorbable suture. Before proceeding, I would test the reconstruction intraoperatively: check that the augmented tendon glides smoothly in the fibular groove without catching, verify that eversion strength is restored, and ensure full ankle ROM. I would also assess the SPR - if torn, it would need reconstruction, and I would check the fibular groove depth - if shallow (less than 2mm), I might consider groove deepening to prevent future impingement.

VIVA SCENARIOStandard

EXAMINER

"During peroneal tendon surgery, you encounter brisk bleeding from what appears to be the peroneal artery. Describe your immediate management and how you prevent this complication."

EXCEPTIONAL ANSWER

Peroneal artery injury is a serious but fortunately rare complication. My immediate management would focus on hemorrhage control and vascular assessment. First, I would apply direct pressure with a surgical sponge or laparotomy pad to achieve temporary hemostasis. I would request immediate availability of vascular instruments including vascular clamps, if not already on the table. With an assistant maintaining pressure, I would obtain proximal and distal control of the vessel. The peroneal artery lies deep to the peroneal tendons in the posterior compartment, approximately 2-3cm anterior to the fibula in the proximal exposure area. Once I have the field under control, I would assess the extent of the injury - is it a small branch vessel that can be ligated, or is it the main peroneal artery? For small perforating branches, bipolar cautery or suture ligation with 4-0 absorbable suture is typically sufficient. However, if the main peroneal artery is injured, I need to make a critical decision. I would assess the patient's vascular status preoperatively (any known PVD, diabetes, smoking history) and the status of the other vessels (posterior tibial and anterior tibial arteries). In most patients with intact tibial vessels, the peroneal artery can be ligated without consequence as there is adequate collateral flow through the posterior tibial and anterior tibial systems. I would ligate the vessel proximally and distally with 2-0 or 3-0 non-absorbable sutures (silk or prolene). However, if the patient has known PVD, the vessel is the dominant blood supply, or I have any concern about foot perfusion, I would strongly consider vascular surgery consultation for potential repair versus bypass. After achieving hemostasis, I would carefully check pedal pulses - dorsalis pedis and posterior tibial - and assess capillary refill. If there is any concern about perfusion, I would obtain intraoperative Doppler assessment and potentially angiography. Prevention is obviously preferable. The key is to stay within the correct surgical plane. The peroneal tendons are in the retrofibular space, and my dissection should remain within or immediately adjacent to the tendon sheath. The peroneal artery is deep and anterior to the tendons - I prevent injury by avoiding excessive deep dissection anterior to the tendons. During SPR reconstruction and tendon sheath opening, I work from posterior to anterior, staying in the superficial plane. When placing bone tunnels or anchors in the fibula, I direct them posteriorly, not anteriorly toward the neurovascular structures. I also limit proximal dissection to only what's necessary for the repair or reconstruction. If performing groove deepening, I stay on bone and avoid penetrating the anterior cortex which could injure deeper structures.