BACKGROUND: Junctional kyphosis (JK) is usually observed in long-level instrumented fusion surgeries. Various contributing factors are proposed, the pre-existing and postoperative spinal imbalance is considered as the single most important factor for the development of JK in adult spinal deformity surgeries. Distal JK (DJK) is seldom reported compared to proximal JK (PJK), and scarce literature exists. METHODS: We report 2 unique cases of distal junctional failure (DJF) with worsening of neurology, secondary to nontraumatic fracture of a lower instrumented vertebra operated for thoracic canal stenosis without deformity. The first case had acute worsening of the Neurology during follow up and on evaluation, the supine CT and MRI scan revealed well decompressed spinal canal, no implant migration to the canal, no screw loosening, or rod failure. Supine sitting radiographs demonstrated DJK with Fracture and the patient underwent extension of fusion till the pelvis with 3-rod construct and interbody fusion, because of the instability at the L1 level.The second case remained neurologically stable for a month and then had an acute onset of back pain, sensory deficit, and urine incontinence. The supine-sitting dynamic radiograph done demonstrated L1 fracture with DJK at D12-L1 levels. The patient was counseled for extension of fusion, which was deferred by the patient. RESULTS: Patients in our series, had an acute worsening of neurological deficit within a month of posterior spinal fixation. Their supine imaging was almost normal, and the diagnosis of DJK with L1 fracture instability was possible only on a supine-sitting dynamic radiograph. Various factors like obesity, TL kyphosis, osteoporosis, etc. can be the attributing factors for the development of DJK CONCLUSION: A high index of suspicion is required for diagnosing nontraumatic fracture in long-level fusion patients with acute neurological worsening. The supine-sitting dynamic radiograph is an important diagnostic tool for DJF in patients having difficulty standing erect. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: Application of sitting and supine dynamic radiographs to diagnose instability in patients unable to stand for flexion and extension radiographs. This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery.
BACKGROUND: Junctional kyphosis (JK) is usually observed in long-level instrumented fusion surgeries. Various contributing factors are proposed, the pre-existing and postoperative spinal imbalance is considered as the single most important factor for the development of JK in adult spinal deformity surgeries. Distal JK (DJK) is seldom reported compared to proximal JK (PJK), and scarce literature exists. METHODS: We report 2 unique cases of distal junctional failure (DJF) with worsening of neurology, secondary to nontraumatic fracture of a lower instrumented vertebra operated for thoracic canal stenosis without deformity. The first case had acute worsening of the Neurology during follow up and on evaluation, the supine CT and MRI scan revealed well decompressed spinal canal, no implant migration to the canal, no screw loosening, or rod failure. Supine sitting radiographs demonstrated DJK with Fracture and the patient underwent extension of fusion till the pelvis with 3-rod construct and interbody fusion, because of the instability at the L1 level.The second case remained neurologically stable for a month and then had an acute onset of back pain, sensory deficit, and urine incontinence. The supine-sitting dynamic radiograph done demonstrated L1 fracture with DJK at D12-L1 levels. The patient was counseled for extension of fusion, which was deferred by the patient. RESULTS: Patients in our series, had an acute worsening of neurological deficit within a month of posterior spinal fixation. Their supine imaging was almost normal, and the diagnosis of DJK with L1 fracture instability was possible only on a supine-sitting dynamic radiograph. Various factors like obesity, TL kyphosis, osteoporosis, etc. can be the attributing factors for the development of DJK CONCLUSION: A high index of suspicion is required for diagnosing nontraumatic fracture in long-level fusion patients with acute neurological worsening. The supine-sitting dynamic radiograph is an important diagnostic tool for DJF in patients having difficulty standing erect. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: Application of sitting and supine dynamic radiographs to diagnose instability in patients unable to stand for flexion and extension radiographs. This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery.
Authors: Virginie Lafage; Christopher Ames; Frank Schwab; Eric Klineberg; Behrooz Akbarnia; Justin Smith; Oheneba Boachie-Adjei; Douglas Burton; Robert Hart; Richard Hostin; Christopher Shaffrey; Kirkham Wood; Shay Bess Journal: Spine (Phila Pa 1976) Date: 2012-02-01 Impact factor: 3.468
Authors: Thomas G Lowe; Lawrence Lenke; Randal Betz; Peter Newton; David Clements; Thomas Haher; Alvin Crawford; Lynn Letko; Lucas A Wilson Journal: Spine (Phila Pa 1976) Date: 2006-02-01 Impact factor: 3.468
Authors: Yongjung J Kim; Keith H Bridwell; Lawrence G Lenke; Chris R Glattes; Seungchul Rhim; Gene Cheh Journal: Spine (Phila Pa 1976) Date: 2008-09-15 Impact factor: 3.468