Physeal Bar Resection

Indication. A skeletally immature child with a partial physeal bar (bony bridge) across a growth plate, producing progressive angular deformity or limb-length discrepancy, where the bar occupies less than roughly 50 percent of the physis cross-section on CT arthrography or MRI, and the child has at least 2 years or 2 cm of growth remaining at the affected physis (confirmed by bone age). The single most important pre-operative question is always: is there enough growth remaining to make resection worthwhile? Absolute indications.

• Partial physeal bar occupying less than roughly 50 percent of the physis cross-section, confirmed on CT arthrography or MRI
• Progressive angular deformity or limb-length discrepancy attributable to the partial arrest
• Sufficient growth remaining: at least 2 years or 2 cm of growth potential at the affected physis
• Open physis on the affected and contralateral side Relative indications.
• Bar between 30 and 50 percent of the physis — proceed if sufficient growth remains and the bar is surgically accessible (peripheral location favoured)
• Multi-level physeal arrest (rare) — staged resection at different sites may be considered
• Patient and family preference for growth-reserving surgery over completion epiphysiodesis Contraindications.
• Absolute: bar greater than 50 percent of the physis (too large, high recurrence, insufficient healthy physis remaining); insufficient growth remaining (less than 2 years or less than 2 cm); near-complete or complete skeletal maturity; active infection at the operative site.
• Relative: central bar in a joint with limited surgical access (for example a central distal femoral bar with high risk to articular cartilage); previous failed resection at the same site; significant medical comorbidities or poor bone quality; complex multiplanar deformity better addressed by acute osteotomy and external fixation. The central decision — resection vs completion epiphysiodesis. Resection is chosen when the bar is small enough, growth remaining is sufficient, and the surgeon expects meaningful spontaneous correction of the angular deformity or limb-length discrepancy through resumed growth. Completion epiphysiodesis is chosen when the bar is too large, growth remaining is too little, or the deformity is severe enough that spontaneous growth correction will be insufficient even if the bar is excised — here the entire physis is surgically arrested (drilling, curettage or a cannulated screw), contralateral epiphysiodesis is timed to manage the limb-length discrepancy, and lengthening is added if the predicted final discrepancy is unacceptable.

Consent. Counsel specifically on the risk of bar recurrence (10 to 30 percent), incomplete correction, progressive deformity requiring further surgery, infection, nerve or vessel injury (particularly around the knee and ankle), and the possibility that completion epiphysiodesis may ultimately be required if resection fails. Setup. Supine on a radiolucent table, with a sandbag or bump under the ipsilateral hip to improve access for medial distal femoral or proximal tibial approaches. Thigh tourniquet for distal femoral and proximal tibial procedures; calf tourniquet or no tourniquet for distal tibial work. General anaesthesia with a peripheral nerve block (femoral or sciatic, depending on site) for post-operative analgesia. The image intensifier must obtain true AP and lateral views of the affected physis before draping, and a separate sterile field is prepared for fat graft harvest from the buttock or lower abdomen.

The goal is to expose the physis adjacent to the bar, excise the bony bridge completely back to healthy cartilage, fill the cavity with interposition material to prevent re-formation, and restore longitudinal growth — correcting any established angular deformity with a concurrent osteotomy when needed. The approach is dictated by the bar's location: peripheral bars are reached through a metaphyseal cortical window, central bars through a drill trajectory across the epiphysis. The image intensifier is the surgeon's constant guide throughout.

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Concurrent corrective osteotomy. When an angular deformity is already established at presentation, bar resection resumes growth but cannot correct the existing deformity quickly — a concurrent corrective osteotomy is frequently required.

Closing-wedge, opening-wedge or dome osteotomy is chosen for the site and deformity, fixed with a plate-and-screws, K-wires or external fixation depending on bone quality and the surgical plan.

Post-operative protocol | Phase | Timing | Management | |-------|--------|-----------| | Immobilisation | 0–4–6 weeks | Above- or below-knee back-slab or cast (follow osteotomy protocol if combined); elevation for 48 hours; wound check at 7–10 days, sutures out at 10–14 days | | Rehabilitation | 4–12 weeks | Protected weight-bearing from 4–6 weeks progressing to full; gentle active and active-assisted ROM; gait re-education and quadriceps/hamstrings reactivation for femoral/tibial sites | | Monitoring | 2+ years to maturity | Serial radiographs every 3–6 months then annually; MRI or CT arthrography at 6–12 months for recurrence and interposition integrity; plot deformity and LLD on a Moseley straight-line chart at each visit | Thromboprophylaxis is not routinely required for paediatric lower-limb surgery in mobile patients; consider mechanical prophylaxis in adolescents with additional risk factors. Most children return to activity as the physis resumes growth, with the best results in younger children with smaller peripheral bars and longer growth remaining. Complications

When resection fails. If recurrence is detected on the 6 to 12-month MRI/CT and growth remains sufficient, revision resection is reasonable; if growth is now insufficient, completion epiphysiodesis of the affected physis — with contralateral epiphysiodesis or planned lengthening — is the pragmatic, more predictable fallback. Remember that recurrent deformity may be a secondary tether at a different site on the same physis rather than regrowth of the original bar, so re-image with CT or MRI before planning revision.

Epidemiology and common sites. Physeal bars form most often around the knee and ankle because these physes contribute the greatest proportion of remaining limb growth. The distal femur contributes approximately 9 mm per year of lower-limb growth and closes around age 14 in girls and 16 in boys; the proximal tibia approximately 6 mm per year (similar closure ages); the distal tibia approximately 5 mm per year (closes slightly earlier). A small bar at the distal femur — the single largest contributor to lower-limb growth — can therefore produce rapid and severe progressive deformity or limb-length discrepancy. The physis — relevant anatomy. The growth plate is a cartilaginous disc organised into zones from the epiphyseal to the metaphyseal side: the resting (germinal) zone of reserve chondrocytes, the proliferative zone of rapidly dividing cells in longitudinal columns, the hypertrophic zone (the weakest zone and the site of Salter-Harris fracture separation), and the zone of provisional calcification where columns mineralise before replacement by metaphyseal bone. It is tethered circumferentially by the perichondral ring (ring of La Croix) and the periosteum, which provide mechanical stability and must be protected during surgical approaches. The germinal zone is fed by epiphyseal vessels (disruption by infection or fracture can arrest growth), while the metaphyseal side is fed by nutrient vessels whose interruption does not typically affect growth. Physes close centripetally (periphery before centre) and at different rates by bone and sex. Pathophysiology — why the deformity progresses. A bar forms when physeal cartilage is destroyed or disrupted — by a Salter-Harris type III to V fracture (especially IV and V), periarticular osteomyelitis, iatrogenic injury (surgical approach or hardware crossing the physis), thermal or radiation injury, tumour or tumour resection, or ischaemic injury. The arrested portion stops producing longitudinal growth while the remaining open physis continues, creating asymmetric growth: progressive valgus or varus at the affected physis (a lateral distal femoral bar causes progressive valgus), shortening if the medial-lateral span is partially tethered, or both. The rate of progression depends on the remaining growth velocity, the proportion of the physis arrested, and the bar's distance from the mechanical axis. Peterson classification of physeal bars.

Key evidence. Langenskiold (1967) described the original technique of bar resection with autologous fat graft interposition in the distal femur and proximal tibia — passing through a metaphyseal cortical window, excising the bridge under direct vision, and filling the defect with free fat from the buttock or abdomen; this remains the foundational technique. Peterson (1984) classified bars by type (peripheral, central, linear, combined) and correlated location and size with outcome — peripheral and smaller bars had better correction and lower recurrence, and this classification still guides planning and prognostication. CT arthrography (contrast injected before scanning) has historically been the gold standard for surgical planning, while MRI with cartilage-sensitive sequences (T2-weighted fat-suppressed or SPGR) is increasingly preferred as it avoids ionising radiation and visualises both the osseous bar and the cartilaginous physis on one study. Published series report complete resolution or significant improvement in approximately 50 to 80 percent of peripheral bars and 30 to 60 percent of central bars, with recurrence of 10 to 30 percent (highest with central bars and fat graft resorption).