Spine Publish Ahead of Print DOI: 10.1097/BRS.0000000000000908
Commentary Paul D Sponseller MD
EP TE D
Johns Hopkins University, Baltimore MD
Classification systems are popular tools to organize clinical planning. Articles establishing them are among the most highly cited in Orthopaedic literature. The process of classification
development has evolved from expert opinion handed down by influential surgeons, to evidencebased works, to consensus-guided processes following formal methodology. The current article, “Results of the 2014 SRS survey on PJK/PJF: A report on practice pattern variation, treatment indications, and membership opinion on classification development”, documents the early phases of consensus development. In it, the authors survey a subset of Scoliosis Research Society
(SRS) members who treat adult spine deformity. They ask about proximal junctional kyphosis
C C
(PJK) and proximal junctional failure (PJF). Issues explored included definitions, prevalence, classification, prevention and treatment. The response rate was respectable for a survey, at 39%, and represented the world-wide scope of the SRS, including 99 surgeons from outside of the United States along with 127 within it. Most
A
of the respondents agreed with the proposed definition of PJK as a 20 degree deformity occurring over the two segments above the upper instrumented vertebra (1,2). They also define PJF as the severe version of this requiring surgery due to pain, prominence, implant failure, or neurologic deficit. Perhaps the most powerful aspect of this article was the statement that 42% of respondents have had a patient develop neurologic deficit from proximal junctional problems!
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
The majority of those surveyed agree that the problem is serious, and that a classification is needed. Most surgeons currently have their planning affected by this, as indicated by the number that use a preventive strategy. The authors also make an attempt to characterize the prevention
EP TE D
methods used, including transitional bends, proximal hooks, and vertebral augmentation (3).
Given the survey methodology, some questions naturally arise:
- How can we assess the accuracy of the responses about frequency of PJK? How can we assess the accuracy of preventive treatments used?
-Hos can we know if the respondents’impressions of risk factors are accurate, without outcomes data?
The strength of this study is the timeliness of the topic as well as the opinions of those surgeons
C C
working "in the trenches" throughout the world. The limitation is that it is impossible to validate the survey responses. Also, the responses of those surgeons who have a lot of experience and have given the problem significant study are not differentiated from those who done less. The article is strongest where the focus is on the theoretical questions (such as the most
A
appropriate definition of PJK or the importance of the problem). It is also strongest where it highlights the practice variation, which surely provides an opportunity for further study and improvement. The authors are commended for building clinical support for classificationbuilding. They have shown the importance of the topic and the nature of the risk factors and possible interventions they will need to study. We look forward to an evidence-based consensus
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
process to develop this classification. The next steps will be to use these themes during an interactive process and to validate the results using actual data.
The manuscript submitted does not contain information about medical device(s)/drug(s). No
submitted work. References:
EP TE D
funds were received in support of this work. No relevant financial activities outside the
1. Kim HJ, Bridwell KH, Lenke LG, et al. Proximal junctional kyphosis results in inferior SRS pain subscores in adult deformity patients. Spine (Phila Pa 1976) 2013;38:896-901. 2. Bridwell KH, Lenke LG, Cho SK, et al. Proximal junctional kyphosis in primary
adultdeformity surgery: evaluation of 20 degrees as a critical angle. Neurosurgery
C C
2013;72:899-906.
3. Kebaish KM, Martin CT, O'Brien JR, et al. Use of vertebroplasty to prevent proximal
junctional fractures in adult deformity surgery: a biomechanical cadaveric study. The spine
A
journal : official journal of the North American Spine Society 2013;13:1897-903.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Commentary Paul D Sponseller MD
EP TE D
Johns Hopkins University, Baltimore MD
Classification systems are popular tools to organize clinical planning. Articles establishing them are among the most highly cited in Orthopaedic literature. The process of classification
development has evolved from expert opinion handed down by influential surgeons, to evidencebased works, to consensus-guided processes following formal methodology. The current article, “Results of the 2014 SRS survey on PJK/PJF: A report on practice pattern variation, treatment indications, and membership opinion on classification development”, documents the early phases of consensus development. In it, the authors survey a subset of Scoliosis Research Society
(SRS) members who treat adult spine deformity. They ask about proximal junctional kyphosis
C C
(PJK) and proximal junctional failure (PJF). Issues explored included definitions, prevalence, classification, prevention and treatment. The response rate was respectable for a survey, at 39%, and represented the world-wide scope of the SRS, including 99 surgeons from outside of the United States along with 127 within it. Most
A
of the respondents agreed with the proposed definition of PJK as a 20 degree deformity occurring over the two segments above the upper instrumented vertebra (1,2). They also define PJF as the severe version of this requiring surgery due to pain, prominence, implant failure, or neurologic deficit. Perhaps the most powerful aspect of this article was the statement that 42% of respondents have had a patient develop neurologic deficit from proximal junctional problems!
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
The majority of those surveyed agree that the problem is serious, and that a classification is needed. Most surgeons currently have their planning affected by this, as indicated by the number that use a preventive strategy. The authors also make an attempt to characterize the prevention
EP TE D
methods used, including transitional bends, proximal hooks, and vertebral augmentation (3).
Given the survey methodology, some questions naturally arise:
- How can we assess the accuracy of the responses about frequency of PJK? How can we assess the accuracy of preventive treatments used?
-Hos can we know if the respondents’impressions of risk factors are accurate, without outcomes data?
The strength of this study is the timeliness of the topic as well as the opinions of those surgeons
C C
working "in the trenches" throughout the world. The limitation is that it is impossible to validate the survey responses. Also, the responses of those surgeons who have a lot of experience and have given the problem significant study are not differentiated from those who done less. The article is strongest where the focus is on the theoretical questions (such as the most
A
appropriate definition of PJK or the importance of the problem). It is also strongest where it highlights the practice variation, which surely provides an opportunity for further study and improvement. The authors are commended for building clinical support for classificationbuilding. They have shown the importance of the topic and the nature of the risk factors and possible interventions they will need to study. We look forward to an evidence-based consensus
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
process to develop this classification. The next steps will be to use these themes during an interactive process and to validate the results using actual data.
The manuscript submitted does not contain information about medical device(s)/drug(s). No
submitted work. References:
EP TE D
funds were received in support of this work. No relevant financial activities outside the
1. Kim HJ, Bridwell KH, Lenke LG, et al. Proximal junctional kyphosis results in inferior SRS pain subscores in adult deformity patients. Spine (Phila Pa 1976) 2013;38:896-901. 2. Bridwell KH, Lenke LG, Cho SK, et al. Proximal junctional kyphosis in primary
adultdeformity surgery: evaluation of 20 degrees as a critical angle. Neurosurgery
C C
2013;72:899-906.
3. Kebaish KM, Martin CT, O'Brien JR, et al. Use of vertebroplasty to prevent proximal
junctional fractures in adult deformity surgery: a biomechanical cadaveric study. The spine
A
journal : official journal of the North American Spine Society 2013;13:1897-903.
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
