Remplissage: Should we take it seriously?

Topic / Overview

Background / Problems

• Failure of Isolated Soft-Tissue Repair:
  • Burkhart and DeBeer (2000) demonstrated that significant bone defects drastically increase failure rates after isolated arthroscopic stabilization:
    • Non-contact athletes: Recurrence increased to 67%.
    • Contact athletes: Recurrence increased to 89%.
• Risk Factors for Recurrent Instability:
  • Glenoid bone loss exceeding critical/subcritical thresholds:
    • Historically set at 25%; modern literature (e.g., Tokish et al.) indicates risks begin at >13% to 15%.
  • Large or engaging Hill-Sachs lesions.
  • Concomitant anterior or inferior shoulder hyperlaxity.
• Geographic Trends & Philosophies:
  • In Europe and globally, the open or arthroscopic Latarjet procedure is widely utilized; however, it carries recognized rates of neurovascular complications, graft-related issues, and long-term secondary osteoarthritis.
  • In North America, arthroscopic preservation strategies (Bankart + remplissage) are favored initially when bone loss remains within acceptable thresholds to avoid the morbidity of coracoid transfer.
• Historical Evolution of Remplissage:
  • Open technique (1972): Described by Connolly in an AAOS Instructional Course Lecture (transfer of infraspinatus tendon and a bone block into the defect).
  • Arthroscopic technique (2004): Developed and popularized by Eugene Wolf (presented at the Nice Shoulder Course), securing the posterior capsule and infraspinatus tendon directly into the abraded Hill-Sachs defect.
  • Initial Skepticism: Centered on concerns regarding biological healing, persistent posterior shoulder pain, infraspinatus weakness, and permanent loss of external rotation.

Classification or Concept

1. Glenoid Track Concept (Yamamoto et al., 2007)

• Assesses dynamic contact between the posterior humeral head and the anterior glenoid rim during functional abduction and external rotation.
• Glenoid Track Width ($GT$):
  $$GT = 0.84 \times D – d$$
  (Where $D$ is the estimated native glenoid diameter, $0.84$ represents 84% native width, and $d$ is the anterior glenoid bone defect width).
• On-Track vs. Off-Track:
  • On-track: The Hill-Sachs lesion stays within the glenoid track margin; low risk of anterior engagement over the glenoid rim.
  • Off-track: The medial margin of the Hill-Sachs lesion extends medial to the glenoid track ($Hill\text{-}Sachs\text{ index} > GT$); high risk of engagement and recurrent dislocation requiring surgical intervention (remplissage or bone augmentation).

2. Dual Biomechanical Mechanism of Remplissage

• Defect Infill / Physical Barrier: Fills the posterolateral trough, rendering it extra-articular and preventing the medial edge of the defect from catching/engaging on the anterior glenoid rim.
• Tenodesis / Checkrein Effect: Capsulotenodesis of the infraspinatus provides a dynamic posterior tether that resists excessive anterior translation of the humeral head during abduction and external rotation.

Indications / Patient Selection

Speaker’s Algorithmic Approach to Glenoid Bone Loss

• Ideal Remplissage Candidates:
  • Traumatic recurrent anterior instability.
  • Engaging or off-track Hill-Sachs defect (small-to-medium; $<20\text{–}25\%$ articular involvement).
  • Subcritical glenoid bone loss ($<13\text{–}15\%$).
• Contraindications to Isolated Remplissage:
  • Substantial glenoid bone loss ($>15\%$, inverted-pear glenoid).
  • Massive humeral head defects ($\ge 30\%$ articular surface) $\rightarrow$ Requires structural osteochondral allograft or metal resurfacing (e.g., HemiCAP).
  • Concomitant full-thickness rotator cuff tears.
  • Failed prior remplissage (Speaker’s preference): Proceed to Latarjet rather than repeat remplissage due to compromised, attenuated posterior capsule.

Technique / Principles

Patient Setup & Viewing

• Performed in either the beach-chair or lateral decubitus position.
• Standard portals: Anterosuperior viewing portal; posterolateral working portal.
• Visualization aids:
  • Translate the humeral head anteriorly or apply rotation to expose the posterior defect.
  • A $70^\circ$ arthroscope placed through the anterosuperior portal facilitates “looking around the corner” into the deep posterior defect without needing extensive head translation.

Step-by-Step Surgical Execution

1. Diagnostic Arthroscopy & Engagement Assessment:
   • Evaluate glenoid and humeral bone defects.
   • Take the arm out of traction, position it in abduction and external rotation (ABER), and dynamically observe under direct vision whether the Hill-Sachs lesion engages the anterior rim.
2. Defect Preparation:
   • Clear fibrous tissue and lightly decorticate/abrade the bed of the Hill-Sachs defect down to bleeding bone to promote tendon-to-bone healing.
   • Address hard subchondral humeral head bone by tapping anchors if necessary to prevent hardware breakage.
3. Anchor Insertion:
   • Maintain the operative cannula extra-capsular (in the subacromial/subdeltoid space) to avoid tethering or shredding the capsule.
   • Introduce a drill guide with a sharp trocar percutaneously through the infraspinatus and posterior capsule into the defect.
   • Insert 1 to 2 suture anchors (all-suture, bioabsorbable, or knotless) through separate capsular puncture sites to spread the tenodesis mattress.
   • Critical Caution: Strictly monitor the drill and anchor trajectory; an overly perpendicular or aberrant angle risks penetrating the articular cartilage of the humeral head.
4. Order of Fixation (Surgeon Preference):
   • Option A: Pass and prep the remplissage anchors, perform the anterior labral/Bankart repair, and tie the remplissage sutures last.
   • Option B: Complete the anterior Bankart repair first, then perform remplissage.
   • Nuance: Repairing the anterior labrum first shifts the humeral head posteriorly, which can decrease posterolateral working space unless a $70^\circ$ scope is used.
5. Knot Tying / Securing the Tenodesis:
   • Cinch down the sutures (knotted or knotless) while viewing from the subacromial space or intra-articularly to verify that the posterior capsule and infraspinatus belly compress firmly into the defect trough.
   • Adds an estimated 10 to 15 minutes of operative time to a standard Bankart repair.

Results / Survivorship / Evidence Cited by the Speaker

1. Boileau et al. (Level IV Landmark Study)

• Evaluated 47 patients undergoing arthroscopic Bankart plus remplissage for large Hill-Sachs lesions with $<13\%$ glenoid bone loss.
• Healing: CT arthrography demonstrated satisfactory tendon-to-bone healing in $>75\%$ of cases.
• Motion: External rotation loss was minimal (mean loss $<8^\circ$).
• Stability: 98% of shoulders remained stable at final follow-up.

2. McDonald, Lapner et al. RCT (Winnipeg & Ottawa Sites; JSE 2021)

• Prospective randomized controlled trial comparing Bankart + Remplissage ($n=52$) versus Bankart alone ($n=50$) in patients $\ge 14$ years old with confirmed Hill-Sachs and $<15\%$ glenoid bone loss.
• Short-Term Results (24 Months):
  • Patient-reported outcomes (WOSI, ASES, Simple Shoulder Test) improved significantly from baseline in both groups, with no statistically significant differences between groups.
  • Re-dislocation rate: Bankart alone = 9 vs. Bankart + Remplissage = 3 ($p = 0.05$; Hazard Ratio demonstrated a 3-fold greater risk of re-dislocation without remplissage).
  • Range of motion: Statistically significant loss of external rotation in abduction of $\sim 10^\circ$ at 12 months, which resolved and was no longer significant at 24 months.
  • Structural healing: $>75\%$ healed infill on MRI.
• High-Risk Subgroup Analysis ($>25\text{ mm}$ Hill-Sachs Lesion):
  • Bankart alone: 4 out of 14 (28.6%) re-dislocated.
  • Bankart + Remplissage: 0 out of 26 (0%) re-dislocated.
• Medium-Term Results (48 Months / 4-Year Follow-up):
  • Re-dislocation rate: 22% in Bankart alone vs. 8% in Bankart + Remplissage ($p < 0.05$).
  • Survival analysis revealed the majority of recurrent instability events occur after the initial 20 months, underscoring the necessity of medium-to-long-term surveillance.
  • No significant differences between groups regarding posterior shoulder pain or return to sports (including overhead athletics).

Complications / Limitations

• Articular Cartilage Penetration: Misdirected drill or anchor insertion trajectories can breach the healthy articular surface of the posterior humeral head.
• Anchor Breakage: Dense subchondral bone in the humeral head can break standard anchors if tapping is omitted.
• Transient External Rotation Deficit: A mean loss of approximately $10^\circ$ of external rotation in abduction occurs at 1 year postoperatively (typically resolves by 2 years).
• Inadequate Glenoid Bone Loss Correction: Remplissage cannot compensate for high-grade anterior glenoid deficiency ($>15\%$). Performing it in the presence of an “inverted pear” glenoid leads to early construct failure.
• Diagnostic Delay / Scheduling Pitfall: Patients waiting extended intervals between initial imaging and surgery may experience interval re-dislocations that transform an on-track lesion into an off-track or high-bone-loss state, rendering arthroscopic repair suboptimal.

Practical Clinical Implications

• Preoperative Imaging Protocols:
  • CT Scan: Remains the gold standard for quantifying 2D/3D glenoid bone loss and measuring the exact millimeter dimensions of the Hill-Sachs defect.
  • 3D MRI: Demonstrating comparable accuracy without ionizing radiation, making it increasingly viable in young patient populations.
  • Radiologists should routinely document whether a defect is on-track or off-track relative to calculated glenoid track dimensions.
• Intra-operative Dynamic Assessment:
  • Take the arm out of traction and examine in $90^\circ$ abduction and maximum external rotation to assess functional engagement before finalizing the operative plan.
• Technical Execution:
  • Keep the posterolateral operative cannula outside the joint capsule; only the drill guide should pass through the capsule and infraspinatus.
  • Drill and place anchors with a trajectory angled safely into the humeral cancellous bed to prevent articular surface perforation.
  • Incorporate a $70^\circ$ arthroscope via the anterosuperior portal to simplify posterolateral visualization without depending on excessive manual head displacement.

Key Take-Home Points

1. Remplissage Significantly Cuts Recurrence: At 4-year follow-up, adding remplissage to a Bankart repair reduces the recurrent instability rate from 22% down to 8% ($p < 0.05$).
2. ER Loss is Transient: While external rotation in abduction decreases by $\sim 10^\circ$ at 12 months, this deficit resolves by 24 months, with no negative impact on return to overhead sports.
3. No Added Posterior Pain: Controlled prospective trials show no increased incidence of persistent posterior shoulder pain compared to isolated Bankart repair.
4. Boundary Limit: Remplissage is intended for subcritical glenoid bone loss ($<15\%$). If glenoid deficiency exceeds 15% or an inverted-pear morphology is encountered, conversion to a Latarjet procedure is indicated.

Exam Pearls

• Burkhart & DeBeer Thresholds (2000): Untreated significant bone defects treated with isolated arthroscopic Bankart repairs result in recurrent instability in 67% of non-contact athletes and 89% of contact athletes.
• Glenoid Track Factor: Native glenoid track width equals $84\%$ of native glenoid diameter ($0.84 \times D$). A lesion is off-track if the medial extent of the Hill-Sachs defect extends beyond this contact zone.
• RCT Failure Disparity: In McDonald’s trial, failure curves diverge primarily after 20 months, culminating in a 22% failure rate for Bankart alone versus 8% for Bankart + Remplissage at 4 years.
• High-Risk Lesion Response ($>25$ mm): In defects exceeding 25 mm, Bankart repair alone yielded a 28.6% dislocation rate, whereas adding remplissage resulted in a 0% dislocation rate.
• Wolf vs. Connolly: Connolly first described an open infraspinatus-bone transfer in 1972; Eugene Wolf adapted it to an all-arthroscopic soft-tissue capsulotenodesis in 2004.
• Viva Question (Managing Failed Remplissage): If a remplissage fails, repeating the procedure is generally avoided because the posterior capsule is attenuated and scarred; the standard revision bailout is a Latarjet coracoid transfer.