The Accordion Maneuver: A Noninvasive Strategy for Absent or Delayed Callus Formation in Cases of Limb Lengthening

Table 1

Clinical data for patients who underwent the accordion maneuver.

Data	Case number 1	Case number 2	Case number 3	Case number 4
Age and gender	18 y.o., female	10 y.o., male	20 y.o., male	18 y.o., male
Diagnosis	Blount disease	Fibular hemimelia	Tibial hemimelia	HME^1
Indication for surgery, LLD	LLD, L < R 6 cm	LLD, L < R 5.2 cm	LLD, R < L 5 cm	LLD, L < R 4 cm
Surgical procedure	Tibial lengthening with circular Ilizarov	Tibial lengthening with circular Ilizarov	Tibial lengthening with circular Ilizarov	Tibial lengthening with circular Ilizarov
Comorbidities	None	None	None	None
Start time of accordion maneuver	5 weeks after surgery	4 weeks after surgery	3 weeks after surgery	7 weeks after surgery
Lengthening process description	Latency period: 4 days; Distraction: 0.25 mm × 4 times (1 mm)/day for 4.5 weeks and then the accordion maneuver^2 was initiated and lasted for 7 weeks; Final distraction: 0.25 mm × 2 times (0.5 mm)/day for 2 weeks	Latency period: 6 days; Initial distraction: 0.25 mm × 2 times (0.5 mm)/day for 2 weeks and then; the accordion maneuver was initiated and lasted for 4 weeks; Final distraction: 0.25 mm × 4 times (1 mm)/day for 2 weeks and then 0.25 mm × 2 times (0.5 mm)/day for 4 weeks	Latency period: 8 days; Initial distraction: 0.25 mm distraction × 3 times (0.75 mm)/day for 2 weeks,; and then; the accordion maneuver was initiated and lasted for 9 weeks, stopping the lengthening thereafter	Latency period: 6 days; Initial distraction: 0.25 mm distraction × 2 times (0.5 mm)/day for 6 weeks,; and then; the accordion maneuver was initiated and lasted for 7 weeks, stopping the lengthening thereafter
Total lengthening duration	14 weeks	12 weeks	11 weeks	13 weeks
Lengthening achieved	5 cm	4.4 cm	3 cm	3.3 cm
Residual LLD^3	1 cm	0.8 cm	2 cm	0.7 cm
Lengthening index	19.6 days/cm	19.09 days/cm	25.66 days/cm	27.57 days/cm
Healing index	52.8 days/cm	54.1 days/cm	122.5 days/cm	72.12 days/cm
Outcome and complications	Bone regenerate observed at 6 weeks within the accordion. Had transient peroneal nerve palsy	Bone regenerate observed at 4 weeks within the accordion. Had 5 degrees of knee flexion contracture. 3 weeks after frame removal (9-month post-op), the regenerate was fractured and was nailed, ultimately healed	No bone regenerate formed after the accordion maneuver. Had infection, was successfully treated with antibiotics, and was followed up 7 months later by bone grafting and OP-1^4. Residual bowing of the tibia. 40 degrees fixed equinus R ankle	Good bone regenerate observed at 6 weeks within the accordion course with no complications
Comments	Underwent concomitant correction of valgus	After 4 weeks of accordion, continued with 1 mm distraction/day for 2 weeks, had fibular premature fusion, and underwent reosteotomy and then continued distraction for another 4 weeks	Infection treated with antibiotics. Absent bone formation after using the accordion maneuver	Had correction of valgus. After finishing the accordion, started distraction 1 mm/day, for 2 days had pain, and stopped

HME: Hereditary Multiple Exostoses.
Accordion maneuver: 0.25 mm distraction in AM, followed by 0.25 mm compression early PM, and then distraction of 0.25 mm late PM (0.25 mm of lengthening/day).
LLD: limb length discrepancy.
OP-1: osteogenic protein-1.