Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Iatrogenic deformity after Harrington rod


Introduction

Adolescent idiopathic scoliosis (AIS) is the most common type of scoliosis, affecting 2% to 4% of adolescents with an occurrence rate of 0.5 to 5.2%. Although the pathophysiology is unclear, there are some studies that suggest a genetic component. While the presence of smaller curvature is similar in males and female at similar rates, there is a higher prevalence of larger curvatures seen in women.

The treatment of AIS has been significantly advanced since the introduction of Harrington rods in the 1960s. While this technique represented a significant development during its time, it was limited in its ability to correct overall scoliosis and has led to a large number of patients who suffer from flat back syndrome and back pain as they have matured. The introduction of pedicle screws has led to better outcomes and correction of the three-dimensional deformity associated with AIS and improving upon the pitfalls of Harrington rods including neurological deficit and infection. As AIS patients mature into adulthood, many symptoms develop as a result of flat back resulting from Harrington rods, as well as progression of deformity and adjacent level degeneration at the lower levels, including back and radicular pain due to degenerative changes leading to foraminal stenosis and lateral recess stenosis. Treatment of these complex patients involves innovative thinking and treatment options to address the patient’s symptoms and correction of any progressive deformity.

Example case

  • Chief complaint: back pain

  • History of present illness: This is a 45-year-old female with a history of Harrington rods for spinal deformity as a teenager who presents with progressive back pain for several months. She denies any leg pain or genitourinary symptoms. She unfortunately has had no response to pain medications and/or physical therapy. She underwent imaging that was concerning for flat back syndrome ( Figs. 41.1–41.2 ).

    Fig. 41.1, Preoperative x-rays. (A) Anterioposterior and (B) lateral x-ray demonstrating previously placed Harrington rods with hyperkyphosis of the thoracic spine.

    Fig. 41.2, Preoperative computed tomography myelogram. (A) Sagittal image demonstrating postoperative changes of previous fusion with massive fusion mass.

  • Medications: oxycodone, prednisone, antidepressants

  • Allergies: no known drug allergies

  • Past medical and surgical history: Harrington rod placement as a teenager

  • Family history: noncontributory

  • Social history: none

  • Physical examination: awake, alert, and oriented to person, place, and time; cranial nerves II–XII intact; bilateral deltoids/triceps/biceps 5/5; interossei 5/5; iliopsoas/knee flexion/knee extension/dorsi, and plantar flexion 5/5

  • Reflexes: 2+ in bilateral biceps/triceps/brachioradialis with negative Hoffman; 2+ in bilateral patella/ankle; no clonus or Babinski; sensation intact to light touch

  • Lorin M. Benneker, MD

  • Orthopaedic Surgery

  • Spine Unit

  • Sonnenhofspital,

  • Bern, Switzerland

  • Scott Daffner, MD

  • Orthopaedic Surgery

  • West Virginia University

  • Morgantown, West Virginia, United States

  • Rodrigo Navarro-Ramirez, MD

  • Neurosurgery

  • McGill University

  • Montreal, Quebec, Canada

  • Justin S. Smith, MD, PhD

  • Neurosurgery

  • University of Virginia

  • Charlottesville, Virginia, United States

Preoperative
Additional tests requested

  • Preoperative complete spine x-rays if available

  • MRI T- and L-spine

  • DEXA

  • Orthoradiogram

  • SI joint steroid injections

  • Sagittal CT L-spine through L4-5 and L5-S1 levels

  • L-spine flexion-extension x-rays

  • Pain management evaluation

  • Recumbent T-spine x-rays

  • DEXA

  • Pain management evaluation

  • Psychology evaluation

  • Nutrition evaluation

  • CT myelogram of T- and L-spine

  • Lumbar flexion-extension x-rays

Surgical approach selectedNo implant removal

  • Stage 1: L4-5 and L5-S1 ALIF

  • Stage 2: MIS posterior implant removal and percutaneous L2-pelvis fusion

  • If pain localizes to lumbar spine and pseudoarthrosis at L3-4,

  • Stage 1: L3-4 lateral lumbar interbody fusion

  • Stage 2: L1-pelvis fusion

  • If pain localizes to lumbar spine and pseudoarthrosis at L3-4,

  • L3-S2/Iliac fusion with connection to previous fusion

If pseudarthrosis detected, L2-ilium posterior instrumented arthrodesis, L4-5 and L5-S1 transforaminal lumbar interbody fusion

  • Surgical approach if 21

  • Surgical approach if 80

  • Same approach

  • Same approach

  • Same approach

  • Same approach

  • Same approach

  • Same approach

  • Same approach

  • Same approach

Goal of surgery Pain control and fusion Solid bony arthrodesis Solid bony arthrodesis Solid bony arthrodesis
Perioperative
Positioning

  • Stage 1: supine

  • Stage 2: prone on carbon table

  • Stage 1: lateral decubitus on flat Jackson table

  • Stage 2: prone on Jackson frame

Prone on Jackson table Prone on Jackson table
Surgical equipment Fluoroscopy

  • Stage 1: IOM (EMG), fluoroscopy, cell saver, MIS retractor system

  • Stage 2: IOM (MEP/SSEP), fluoroscopy, surgical robot

  • Fluoroscopy

  • Surgical navigation

  • O-arm

  • Cell saver

  • BMP

  • IOM (MEP/SSEP/EMG)

  • FluoroscopyCell saver

Medications None None Tranexamic acid Tranexamic acid
Anatomical considerations Left iliac vein

  • Stage 1: peritoneum, aorta, vena cava, lumbar plexus

  • Stage 2: pedicles, nerve roots, SI joints

S1-2 foramen, S2 venous plexus Spinal cord and conus, nerve roots, cauda equina
Complications feared with approach chosen Coronal imbalance, Ogilvy syndrome Iliac or gluteal artery injury Global coronal malalignment
Intraoperative
Anesthesia General General General General
Exposure

  • Stage 1: L4-S1

  • Stage 2: L2-pelvis

  • Stage 1: L3-4

  • Stage 2: L2-pelvis

L3-pelvis L2-pelvis
Levels decompressed

  • Stage 1: L4-S1

  • Stage 2: none

  • Stage 1: L3-4

  • Stage 2: none

None None
Levels fused

  • Stage 1: L4-S1

  • Stage 2: L2-pelvis

  • Stage 1: L3-4

  • Stage 2: L2-pelvis

L3-pelvis L2-ilium
Surgical narrative

  • Stage 1: position supine, horizontal skin incision, split rectus, retroperitoneal exposure of L5-S1 and L4-L5, discectomy and decompression through disc scape after sequential distraction and reposition of the segment, insert trial cages under fluoroscopy control, cage should have lordotic angle according to preoperative calculations, insertion of final cage filled with allo/autograft and angular-stable screw fixation, x-ray to confirm hardware location, soft drain placement and closure

  • Stage 2 (same day): position prone, stab incisions, transpedicular placement of k-wires with fluoroscopic control in L2-5 bilaterally and for SI screws, thread and insert poly axial screws, rod insertion, in situ fixation

Stage 1: position lateral with left side up, axillary roll under right chest wall, hip and knee flexed to relax psoas muscle, x-ray to localize incision and able to obtain true AP and lateral projection, 8–10 cm oblique incision centered over L3-4 disc, bluntly split each muscular layer in line with fibers, carefully split transversalis fascia, identify peritoneum, bluntly dissect peritoneum off lateral and posterior abdominal wall, identify psoas, confirm level of exposure, gently elevate psoas, confirm level with x-ray, dock MIS retractor system at middle to anterior 1/3 of disc space, L3-4 discectomy making sure to release contralateral annulus, clean cartilage from end plates and leveled with rasp to punctate bleeding subchondral bone, fluoroscopy to confirm instruments do not pass beyond contralateral annulus, size and place neutral or slightly lordotic cage filled with allograft wrapped in rhBMP-2, impact disc space under fluoroscopy, remove retractor, layered closureStage 2 (same day): sandwich in Jackson frame and position prone, x-ray to confirm location of lateral cage, standard posterior midline exposure, using robot and navigation place pedicle screws bilaterally from L1-5 and bilateral iliac bolts over wire, cut with bur and remove if prior instrumentation in the way otherwise leave intact, contour and insert rods, decorticate exposed bone, spinous processes harvested for autograft and combined with allograft or other extender and placed over decorticated bone, layered closure with drain Position prone, place reference ray over iliac crest, posterior midline incision from L3-S2, work in different areas and pack to minimize blood loss, identify previous hardware and confirm quality of posterolateral fusion, cut previous rods and leave 5 mm segment free of rod to allow connection, pack this area and work on placing pedicle screws from L4-S2, advance S2 screw through iliac cancellous bone using fluoroscopy with tear drop landmark or navigation guidance, place cobalt chrome rod and connect to previous Luque rod using dominoes, decorticate exposed bony elements (laminas, facets, transverse processes, sacrum), irrigate surgical site, remove L4-5 spinous processes and mix with allograft and vancomycin and pack along decorticated site, layered closure with subfascial drain Position prone on Jackson table, fluoroscopy to mark incision, expose upper lumbar spine to sacrum, expose PSIS bilaterally, confirm levels with fluoroscopy once exposed, place pedicle screws L4-S1 bilaterally and on left L2 and L3, place bilateral iliac bolts, L4-5 and L5-S1 transforaminal lumbar interbody fusions place rods bilaterally and connect rod on the right (and possible rod on the left) directly to Luque rods with connectors for added stability, intraoperative long-cassette AP x-ray to assess global coronal alignment and adjust with coronal in situ benders as needed, placement of graft material for arthrodesis, wound closure with two subfascial drains
Complication avoidance Two-staged approach, anterior lordotic cage based on preoperative angle, percutaneous minimally invasive pedicle screw placement Two-staged approach, MIS retractor system, make sure to release contralateral annulus during discectomy, BMP, cut with bur and remove if prior instrumentation in the way Work in different areas and pack to minimize blood loss, domino to previous fusion construct, surgical navigation to guide pedicle screw placement, endovascular team on standby if vascular injury Intraoperative long-cassette x-rays to assess coronal alignment, anchoring of rods to Luque rods for added stability, BMP for arthrodesis
Postoperative
Admission Floor Stepdown unit Floor ICU
Postoperative complications feared Coronal imbalance, Ogilvy syndrome Pseudoarthrosis, overcorrection of sagittal balance, loss of fixation, infection, incisional hernia Pseudoarthrosis, adjacent segment disease, hardware failure, infection Pseudarthrosis, rod fracture, global coronal malalignment
Anticipated length of stay 6–7 days 3 days 4 days 6–7 days
Follow-up testing Standing full spine x-rays prior to discharge, 2 months, 6 months, 12 months after surgery

  • CT L-spine prior to discharge

  • Standing scoliosis x-rays prior to discharge, 6 weeks, 6 months, 12 months,24 months after surgery

Standing AP/lateral L-spine and scoliosis x-rays prior to discharge, 1 month, 3 months after surgery

  • Supine x-rays after surgery

  • Full-length standing x-rays before discharge

  • X-rays at 6 weeks, 1 year, 2 years after surgery

Bracing None None None None
Follow-up visits 2 months, 6 months, 12 months after surgery 2 weeks, 6 weeks, 3 months, 6 months, 12 months, 24 months after surgery 2 weeks, 1 month, 3 months after surgery 10–14 days, 6 weeks, 1 year, 2 years after surgery
ALIF , Anterior lumbar interbody fusion; AP , anteroposterior; BMP , bone morphogenic protein; CT , computed tomography; DEXA , dual-energy x-ray absorptiometry; ESI , epidural spinal injections; IOM , intraoperative monitoring; MAP , mean arterial pressure; MEP , motor evoked potential; MIS , minimally invasive surgery; PLL , posterior longitudinal ligament; PSIS , posterior superior iliac spine; SI , sacroiliac; SSEP , somatosensory evoked potential.

Differential diagnosis

  • ▪

    Iatrogenic scoliosis

  • ▪

    Degenerative scoliosis

  • ▪

    Adolescent idiopathic scoliosis

  • ▪

    Adjacent segment disease

  • ▪

    Hardware failure

  • ▪

    Lumbar stenosis

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here

Related Posts