Medical Papers Lumbar

The Risks of Pedicle Wall Breech with Larger Screws After Untapping

By Dr. Kingsley Chin

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Scientific Paper

Chin KR1, Gibson B.

Interested medical professionals can read the full paper, published also in the Spine Journal, here.

Background Context

A linear relation exists between the insertional torque when placing a screw and the ultimate screw pullout strength; therefore, undertapping of the pedicle followed by insertion of a larger screw may enhance the pullout strength of the screw.

Purpose

To report the risk of pedicle wall breech with placement of 6.2-mm pedicle screws after undertapping with a 5.2-mm tap and to evaluate the effectiveness of direct visualization to identify these breeches. STUDY DESIGN/SETTINGS: Prospective evaluation of risks of pedicle wall breech with undertapping for a larger screw and the utility of directly visualizing pedicle walls during access and placement of pedicle screws for evidence of breech.

Patient Sample

Sixty-five consecutive patients.

Outcome Measures

Intraoperative direct visualization of pedicle wall breech. Postoperative radicular leg symptoms.

Methods

We prospectively analyzed placement of pedicle screws in sixty-five consecutive patients during lumbar-instrumented fusions after laminectomies performed by a single spine surgeon. Forty-four patients were primary fusions, and 21 were revisions. Twenty-seven were male, and 38 were female, with a mean age of 54.7 years (range, 15-85 years). Four hundred twenty-eight total pedicle screws were placed for an average of 6.6 screws per patient (range, 2-12 screws).

Results

The incidence of pedicle wall breech during access was 0.7% (3/428) and 1.6% (7/428) after screw placement. 71% (5/7) of the screw breeches were noted with direct inspection of the pedicles intraoperatively, and 29% (2/7) were identified on postoperative X-ray films as lateral breakthroughs that were missed on intraoperative fluoroscopy and direct visualization. Therefore, 100% of misplaced screws potentially harmful to nerve roots were identified on direct visualization. Eighty percent occurred from L2-4.

Conclusions

This study provides evidence that undertapping of pedicles followed by placement of a larger diameter pedicle screw may breech the pedicle cortices. Although the risk is low, the authors recommend direct visualization of the pedicle walls during screw placement to identify caudad, medial, and cephalad breeches. This technique is for open laminectomies and should be added to the armamentarium of other techniques and not as a replacement.

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board certified Harvard-trained orthopedic spine surgeon and professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Studies at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details

Authors

Chin KR1, Gibson B.

Author information

  1. Spine Surgery Service, Department of Orthopaedic Surgery, University of Pennsylvania Medical School, 2 Silverstein, 3400 Spruce Street, Philadelphia, PA 19104, USA. kingsleychin@hotmail.com

Mini-Open or Percutaneous Bilateral Lumbar Transfacet Pedicle Screw Fixation: a Technical Note

By Dr. Kingsley Chin

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Scientific Paper

Chin KR1, Seale JCumming V.

Interested medical professionals can read through the full paper, as published in Clinical Spine Surgery, here.

Study Objective

Case report.

Objective

To describe the technique used to place bilateral lumbar transfacet pedicle screws.

Summary of Background Data

Transfacet pedicle screw fixation is a growing alternative and biomechanically comparable with traditional pedicle screw fixation. There is no clear description of technique steps for placing transfacet pedicle screws available in the literature, despite recognizing that screw placement is not intuitive even with fluoroscopy, and is dissimilar to placing traditional pedicle screws or translaminar facet screws.

Methods

We present 2 illustrative cases where bilateral transfacet pedicle screws were placed for posterior instrumentation after a step-by-step technique that can be used in a mini-open or percutaenous procedure.

Results

Postoperatively, both patients had adequately placed transfacet pedicle screws bilaterally on x-ray imaging with 1 patient demonstrating fusion and intact fixation at 11 months follow-up.

Conclusions

Transfacet pedicle screws were successfully placed in 2 patients in a stepwise technique described to achieve lumbar fusion.

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board-certified Harvard-trained Orthopedic Spine Surgeon and Professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Sciences at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details

Authors

Chin KR1, Seale JCumming V.

Author information

  1. Institute for Modern & Innovative Surgery (iMIS), Fort Lauderdale †Society of Facet Surgical Techniques and Technologies Inc., LES Society, Wilton Manors, FL.

Safety and Usefulness of Free Fat Grafts After Microdiscectomy Using an Access Cannula: a Prospective Pilot Study and Literature Review

By Dr. Kingsley Chin

Scientific Paper    Chin KR 1,  Bassora R ,  Yu WD .  Interested medical professionals can read the full paper, published also in the American Journal of Orthopedics,  here .   Abstract   Placing an interpositional fat graft over the dura has been practiced to prevent sciatica due to nerve tethering from scar. We assessed feasibility, outcomes, and complications of free fat grafts in patients undergoing lumbar microdiscectomy for herniated discs using an access cannula. Retrospective review of prospectively collected data on 69 consecutive patients: those who received autologous fat graft (Group I) and those who did not (Group II). Clinical evaluation of leg pain and nerve tension sign was performed in the immediate postoperative period and at 1 month, 6 months, 12 months, and 24 months. The combined visual analog scale (VAS) scores for leg pain improved from 8.3 preoperatively to 1.3 (P < 0.5). The average VAS score for leg pain was 1.4 (0 to 3) in Group I and 1.3 (0 to 3) in Group II (P > 0.05). Ninety-one percent had resolution of their leg pain immediately postop and 96% at final follow-up. This study found no increased complications with the use of fat graft, but no clinical benefit, therefore the use of fat graft should be discouraged. The potential complication with the use of fat graft is the “mass effect” on the dura, and therefore, the width of the graft should be <1 cm.   About Author & Orthopedic Surgeon Dr. Kingsley R. Chin    Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute   Dr. Kingsley R. Chin is a board-certified Harvard-trained Orthopedic Spine Surgeon and Professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Sciences at the University of Technology, Jamaica.   Learn more about Dr. Chin    here    and connect via    LinkedIn   .    About Less Exposure Surgery   Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at  LESSociety.org .    The LES Society philosophy : “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD    About The LESS Institute   The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our  patient stories , follow us on  Facebook  and visit  TheLESSInstitute.com  to learn more.   About SpineFrontier   The above study utilized LES Technology from  SpineFrontier  – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.   Scientific Paper Author & Citation Details    Authors    Chin KR 1,  Bassora R ,  Yu WD .   Author information   Charles E Schmidt College of Medicine at Florida Atlantic University and The Less Exposure Surgeons Surgery Institute (LESS Institute), Fort Lauderdale, FL. kingsleychin@Less-Institute.com.

Scientific Paper

Chin KR1, Bassora R, Yu WD.

Interested medical professionals can read the full paper, published also in the American Journal of Orthopedics, here.

Abstract

Placing an interpositional fat graft over the dura has been practiced to prevent sciatica due to nerve tethering from scar. We assessed feasibility, outcomes, and complications of free fat grafts in patients undergoing lumbar microdiscectomy for herniated discs using an access cannula. Retrospective review of prospectively collected data on 69 consecutive patients: those who received autologous fat graft (Group I) and those who did not (Group II). Clinical evaluation of leg pain and nerve tension sign was performed in the immediate postoperative period and at 1 month, 6 months, 12 months, and 24 months. The combined visual analog scale (VAS) scores for leg pain improved from 8.3 preoperatively to 1.3 (P < 0.5). The average VAS score for leg pain was 1.4 (0 to 3) in Group I and 1.3 (0 to 3) in Group II (P > 0.05). Ninety-one percent had resolution of their leg pain immediately postop and 96% at final follow-up. This study found no increased complications with the use of fat graft, but no clinical benefit, therefore the use of fat graft should be discouraged. The potential complication with the use of fat graft is the “mass effect” on the dura, and therefore, the width of the graft should be <1 cm.

About Author & Orthopedic Surgeon Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board-certified Harvard-trained Orthopedic Spine Surgeon and Professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Sciences at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details

Authors

Chin KR1, Bassora R, Yu WD.

Author information

Charles E Schmidt College of Medicine at Florida Atlantic University and The Less Exposure Surgeons Surgery Institute (LESS Institute), Fort Lauderdale, FL. kingsleychin@Less-Institute.com.

Stability of Transforaminal Lumbar Interbody Fusion in the Setting of Retained Facets and Posterior Fixation Using Transfacet or Standard Pedicle Screws

Scientific Paper

Chin KR1, Reis MT2, Reyes PM2, Newcomb AG2, Neagoe A2, Gabriel JP3, Sung RD4, Crawford NR2.

Interested medical professionals can read through the full paper, as published in the Spine Journal, here.

Background Concept

The transforaminal lumbar interbody fusion (TLIF) technique supplements posterior instrumented lumbar spine fusion and has been tested with different types of screw fixation for stabilization. Transforaminal lumbar interbody fusion is usually placed through a unilateral foraminal approach after unilateral facetectomy, although extraforaminal entry allows the facet to be spared.

Purpose

To characterize the biomechanics of L4-L5 lumbar motion segments instrumented with bilateral transfacet pedicle screw (TFPS) fixation versus bilateral pedicle screw-rod (PSR) fixation in the setting of intact facets and native disc or after discectomy and extraforaminal placement of a TLIF technology graft.

Study Design

Human cadaveric lumbar spine segments were biomechanically tested in vitro to provide a nonpaired comparison of four configurations of posterior and interbody instrumentation.

Methods

Fourteen human cadaveric spine specimens (T12-S1) underwent standard pure moment flexibility tests with intact L4-L5 disc and facets. Seven were studied with intact discs, after TFPS fixation, and then with TLIF and TFPS fixation. The others were studied with intact discs, after PSR fixation, and then combined with extraforaminally placed TLIF. Loads were applied about anatomic axes to induce flexion-extension, lateral bending, and axial rotation. Three-dimensional specimen motion in response to applied loads during flexibility tests was determined. A nonpaired comparison of the four configurations of posterior and interbody instrumentation was made.

Results

Transfacet pedicle screw and PSR, with or without TLIF, significantly reduced range of motion during all directions of loading. Transfacet pedicle screw provided greater stability than PSR in all directions of motion except lateral bending. In flexion, TFPS was more stable than PSR (p=.042). A TLIF device provided less stability than the intact disc in constructs with TFPS and PSR.

Conclusions

These results suggest that fixation at L4-L5 with TFPS is a promising alternative to PSR, with or without TLIF. A TLIF device was less stable than the native disc with both methods of instrumentation presumably because of a fulcrum effect from a relatively small footplate. Additional interbody support may be considered for improved biomechanics with TLIF.

Copyright © 2015 Elsevier Inc. All rights reserved.

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board-certified Harvard-trained Orthopedic Spine Surgeon and Professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Sciences at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author and Citation Details

Authors

Chin KR1, Reis MT2, Reyes PM2, Newcomb AG2, Neagoe A2, Gabriel JP3, Sung RD4, Crawford NR2.

Author information

  1. Charles E. Schmidt College of Medicine at Florida Atlantic University, 777 Glades Rd, Building 71, Boca Raton, FL 33431, USA; Department of Orthopaedic Surgery, The LES Spine Institute, 1100 W. Oakland Park Blvd., Suite #3, Fort Lauderdale, FL 33311, USA. Electronic address: kingsleychin@imissurgery.com.

  2. Department of Neurosurgery, Barrow Neurological Institute, St Joseph’s Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ 85013, USA.

  3. Department of Orthopedics, Grant Medical Center, 111 South Grant Ave, Columbus, OH 43215, USA.

  4. The Spine Center at The Colorado Springs Orthopaedic Group, 3010 North Circle Dr, Suite 200, Colorado Springs, CO 80909, USA.

Stabilizing Effects of a Particulate Demineralized Bone Matrix in the L4 Interbody Space with and Without PEEK Cage – A Literature Review and Preliminary Results of a Cadaveric Biomechanical Study

By Dr. Kingsley Chin

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Scientific Paper

Bruce C1, Chin KR2, Cumming V3, Crawford NR4.

Interested medical professionals can read through the full paper, also published the West Indian Medical Journal, here.

Abstract

We reviewed the biological elements supporting the usefulness of a specifically designed particulate form of demineralized bone matrix (DBM) with spinal fusion, and report some limitations of its use described in the medical literature and in the interbody space using a cadaveric biomechanical model. A literature review and description of the techniques used to augment spinal fusion are presented, including a more thorough review of recent findings of cadaveric biomechanical flexibility studies using DBM alone at different percentage fills of the existing disc space and DBM with a polyetheretherketone (PEEK) interbody cage. The need for DBM was established by reviewing limitations of autografts and allografts in spinal fusion. Demineralized bone matrix used alone did not increase stability post discectomy at L4-L5, but was demonstrated to exhibit satisfactory stability when used with a PEEK interbody cage. There may be a future role for DBM that hardens and fills disc space more rigidly, overcoming this limitation to its use.

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board-certified Harvard-trained Orthopedic Spine Surgeon and Professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Sciences at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details

Authors

Bruce C1, Chin KR2, Cumming V3, Crawford NR4.

Author information

  1. Department of Surgery, Radiology, Anaesthesia and Intensive Care, The University of the West Indies, Kingston 7, Jamaica.

  2. Charles E Schmidt College of Medicine at Florida Atlantic University and the Less Exposure Surgeons Surgery Institute (LESS Institute), Fort Lauderdale, FL, USA. kingsleychin@gmail.com.

  3. Less Exposure Surgery Society, Fort Lauderdale, FL, USA.4Barrow Neurological Institute, St Joseph’s Hospital and Medical Center, Phoenix, AZ, USA.

Effects of Misalignment on Static Torsional Strength of Anterior Cervical Plate Systems

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Scientific Paper

Chin KR1, Cumming VBHenson MMurrell BChan FW.

Interested medical professionals can read through the full paper, as published in the Spine Journal, here.

Background

There is little understanding of cervical plate misalignment as a risk factor for plate failure at the plate-screw-bone interface.

Purpose

To assess the torsional strength and mode of failure of cervical plates misaligned relative to the midsagittal vertical axis.

Study Design

Plastic and foam model spine segments were tested using static compression and torsion to assess effects of misaligned and various lengths anterior cervical plate (ACPs).

Methods

Different length ACPs and cancellous fixed angle screws underwent axial torsional testing on a servo-hydraulic test frame at a rate of 0.5°/s. A construct consisted of one ACP, four screws, one ultrahigh-molecular weight polyethylene inferior block, and one polyurethane foam superior block. Group 1 had ACPs aligned in the midsagittal vertical axis, group 2 plates were positioned 20° offset from the midline, and group 3 had the ACP shifted 5 mm away and 20° offset from midline. Torques versus angle data were recorded. The failure criterion was the first sign of pullout determined visually and graphically.

Results

Group 1 had a more direct screw pullout during failure. For the misaligned plates, failure was a combination of the screws elongating the holes and shear forces acting between the plate and block. The misaligned plates needed more torque to failure. The failure torque was 50% reduced for the longer versus the shorter plates in the neutral position. Graphically shown initial screw slippage inside the block preceded visual identification of slippage in some cases.

Conclusions

We observed different failure mechanisms for neutral versus misaligned plates. Clinically, misalignment may have the benefit of needing more torque to fail. Misalignment was a risk factor for failure of the screw-bone interface, especially in longer plate constructs. These comparisons of angulations may be a solid platform for expansion toward a more applicable in vivo model.

Copyright © 2013 Elsevier Inc. All rights reserved.

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board-certified Harvard-trained Orthopedic Spine Surgeon and Professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Sciences at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details

Authors

Chin KR1, Cumming VBHenson MMurrell BChan FW.

Author information

  1. Institute for Modern and Innovative Surgery, 1100 W. Oakland Park Blvd, Suite #3, Fort Lauderdale, FL 33311, USA. Electronic address: kingsleychin@imissurgery.com.

Risk of Progression in De Novo Low-Magnitude Degenerative Lumbar Curves: Natural History and Literature Review

By Dr. Kingsley Chin

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Scientific Paper

Chin KR1, Furey CBohlman HH.

Interested medical professionals can read through the full paper, also published in the American Journal of Orthopedics, here.

Abstract

Natural history studies have focused on risk for progression in lumbar curves of more than 30 degrees, while smaller curves have little data for guiding treatment. We studied curve progression in de novo degenerative scoliotic curves of no more than 30 degrees. Radiographs of 24 patients (17 women, 7 men; mean age, 68.2 years) followed for up to 14.3 years (mean, 4.85 years) were reviewed. Risk factors studied for curve progression included lumbar lordosis, lateral listhesis of more than 5 mm, sex, age, convexity direction, and position of intercrestal line. Curves averaged 14 degrees at presentation and 22 degrees at latest follow-up and progressed a mean of 2 degrees (SD, 1 degrees) per year. Mean progression was 2.5 degrees per year for patients older than 69 years and 1.5 degrees per year for younger patients. Levoscoliosis progressed 3 degrees per year and dextroscoliosis 1 degrees per year (P<.05). Forty-six percent of patients had lateral listhesis of more than 5 mm at L3 and L4. Curve progression was not linear and might occur rapidly, particularly in women older than 69 with lateral listhesis of more than 5 mm and levoscoliosis. Small curves can progress and therefore should be individualized in the context of other risk factors.

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin is a board certified Harvard-trained orthopedic spine surgeon and professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Studies at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details

Authors

Chin KR1, Furey CBohlman HH.

Author information

  1. Institute for Minimally Invasive Spine Surgery (iMIS), West Palm Beach, Florida 33480, USA. kingsleychin@iMISsurgery.com

Success of Lumbar Microdiscectomy in Patients with Modic Changes and Low-Back Pain: a Prospective Pilot Study

Scientific Paper

Chin KR1, Tomlinson DTAuerbach JDShatsky JBDeirmengian CA.

Interested medical professionals can read through the full paper, as published in Clinical Spine Surgery, here.

Study Design

Prospective case controlled.

Objective

To determine the outcome after microdiscectomy in patients with disc herniation, concordant sciatica, and low-back pain with Modic I and II degenerative changes compared with similar patients without Modic changes.

Summary of Background Data

The decision to perform a microdiscectomy versus a fusion or total disc replacement in a patient with a disc herniation and sciatica may be confounded by the presence of low-back pain, degenerative disc disease, and marrow and endplate (Modic) changes.

Methods

Thirty consecutive patients underwent a microdiscectomy by a single surgeon. Group 1 consisted of 15 patients, 6 men and 9 women, with a mean age of 36.7 years (range, 21 to 48 y), with Modic I and II changes. Group 2 contained 15 patients, 9 men and 6 women, with a mean age of 34.1 years (range, 20 to 68 y), without Modic changes. The average duration of low-back pain before surgery was 25.6 months (range 4 to 120 mo) in group 1 and 17.5 months (range 5 to 120 mo) in group 2. The visual analog scale (VAS) was used to grade low-back pain and the Oswestry score was used to grade overall disability.

Results

There was no significant difference in preoperative sciatica, low-back pain, VAS or Oswestry scores for group 1 versus group 2 patients. Postoperatively, all patents had improved sciatica and resolution of any nerve tension sign. Eighty-six percent of patients in group 1 versus 93% of patients in group 2 had improvements in postoperative VAS score for low-back pain at 6 months. Average improvement within each group was 67% and 75%, respectively. VAS scores for low-back pain at 6 months improved from 6.9 to 2.3 (P=0.0005) in group 1 and 6.3 to 1.6 (P=0.0002) in group 2. Group 1 and 2 had 89% and 100% of patients show improvement in postoperative Oswestry score at 6 months with an average improvement of 58% and 84%, respectively. Oswestry scores at 6 months improved from 68.7% to 28.8% (P=0.0007) in group 1 and 61.2% to 9.9% (P=0.00003) in group 2.

Conclusions

There was a trend toward greater improvement in Oswestry scores in patients without Modic changes (P=0.09). Both groups reported statistically significant improvement in sciatica, low-back pain, and disability after microdiscectomy. Microdiscectomy was therefore an effective treatment for disc herniation and concordant sciatica despite low-back pain and Modic I and II degenerative changes.

Level of Evidence

Therapeutic II.

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, Founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board certified Harvard-trained orthopedic spine surgeon and professor with copious business and information technology exposure. He sees a niche opportunity where medicine, business and info. tech meet – and is uniquely educated at the intersection of these three professions. He has experience as Professor of Clinical Biomedical Sciences & Admissions Committee Member at the Charles E. Schmidt College of Medicine at Florida Atlantic University, Professor of Clinical Orthopedic Surgery at the Herbert Wertheim College of Medicine at Florida International University, Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School, Visiting Spine Surgeon & Professor at the University of the West Indies, Mona, and Adjunct Professor of Clinical Biomedical Studies at the University of Technology, Jamaica.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at LESSociety.org.

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit TheLESSInstitute.com to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details

Authors

Chin KR1, Tomlinson DTAuerbach JDShatsky JBDeirmengian CA.

Author information

  1. Spine Surgery Service, Department of Orthopaedics, University of Pennsylvania, Philadelphia, PA 19104, USA.