By Tim Weir DC, PSC, Robb Rattray DC, Paul Birinyi MD, Neurosurgeon, Kevin Baker, MD Radiology, MSK Radiology

Reference: Tim Weir DC, PSC, Robb Rattray DC, Paul Birinyi MD, Neurosurgeon, Kevin Baker, MD Radiology, MSK Radiology, Geoffrey Gerow DC, DIANM. "Intra and Inter-Rater Reliability in Diagnosing Lumbar Post-Traumatic Ligament Injury". Medpix: National Institute of Health/National Library of Medicine. Published November 11, 2024.  https://medpix.nlm.nih.gov/case?id=354eb195-c030-409d-b135-6d8b7920e851

Abstract
Background: Lumbar spine injuries involving multiple soft tissue structures, including the facet capsule, ligamentum flava, interspinous, and supraspinous ligaments, present a complex clinical challenge. This case report examines a patient with such an injury and integrates insights from recent literature and expert opinions to provide a comprehensive overview.

Case Presentation: A 37-year-old male patient sustained a lumbar spine injury following a high-speed impact trauma. Imaging and clinical evaluations revealed damage to the facet capsule, ligamentum flava, interspinous and supraspinous ligaments. The patient presented with severe lower back pain, restricted mobility, and neurological symptoms consistent with these injuries.

Treatment and Outcomes: The management strategy combined conservative care, including chiropractic adjustments, non-surgical decompression, and pain management with advanced spinal stabilization techniques. Dr. Mark Studin's principles of functional rehabilitation and alignment correction were employed to guide the treatment plan. Significant improvements in pain reduction and functional recovery were observed following a tailored regimen. The case also highlighted the utility of Dr. Heidi Haavik's biomechanical insights into spinal injury mechanisms and Panjabi's concepts of spinal stability in understanding the injury's impact and recovery process.

Discussion: This case underscores the multifaceted nature of lumbar spine injuries involving critical soft tissue structures. The integration of Dr. Studin's rehabilitation approaches, Haavik's biomechanical theories, and Panjabi's stability models provide a holistic framework for managing similar injuries. The patient's positive outcome reflects the efficacy of a multidisciplinary approach in treating complex spinal injuries. To establish a demonstrative diagnosis, X-ray digitization was performed using Symverta technology. Prior to finalizing the diagnosis, inter- and intra-rater reliability studies were conducted to ensure precision, yielding an "excellent" score based on Cohen's Kappa statistical analysis.
Keywords: Lumbar spine injury, facet capsule, ligamentum flava, interspinous ligaments, supraspinous ligaments, spinal stability, Studin, Haavik, Panjabi.
History:

Mr. Patient presented for an initial evaluation of injuries sustained in a motor vehicle crash on 3/22/2022. He reported complaints related to the accident, in which he was seated as a rear-right passenger when the vehicle collided with another car.

Mechanism of Injury:

Mr. Patient reported the following: He was the right rear seat passenger in the car stopped in heavy traffic. He was sitting back, leaning to the right when he suddenly felt the impact from behind as a truck hit the left rear of the vehicle. When questioned about wearing seat belts, he replied he was unrestrained. An airbag did not deploy. Mr. Patient states he did not lose consciousness. The patient's vehicle was towed from the scene. When questioned about wearing seat belts, he replied he was unrestrained. An airbag did not deploy. Mr. Patient states he did not lose consciousness. Mr. Patient arranged for a ride home from the scene and self-treated with over-the-counter medications before arriving at our office. The patient complained of discomfort in his mid-back radiating to the lower back at the time of the accident, with supplemental complaints of stress. Mr. Patient states that since the date of the crash, his overall condition and complaints have stayed the same.

Mr. Patient sought treatment, complaining of frequent aching and tightness discomfort in the lower back. Using a Visual Analog Scale (VAS), he rated the intensity of discomfort as a level 7 on a scale of 0 to 10, with 10 being the most severe. The discomfort was reported to increase with movement and prolonged sitting.

HISTORY:
Chief Complaint: Reports an acute complaint in the left and right lumbar regions due to the accident on 3/22/2022.
- Frequency/Quality: Frequent discomfort described as shooting, stiffness and tightness
- Radiation of Symptoms: Currently non-radiating
- Change in Complaint/VAS: The complaint has stayed the same since the onset, and the pain scale is presently rated 7/10 (10 being most severe)
- Modifying Factors: Relieved by nothing and aggravated by bending, carrying or lifting and sitting in a car or chair
- Previous Episodes: Denies past episodes
- Previous Care: Since the onset of this condition, he has received no other medical or chiropractic service.
- Recent Diagnostic Tests: Denies recent diagnostic testing

Systems Review: Mr. Patient reports the status of condition(s) below, which may relate to the complaint(s):

- Musculoskeletal: Other than presenting musculoskeletal complaints, the patient denies osteoarthritis, osteoporosis, joint replacement(s), or other history of bone or joint concerns, including lack of any pins and screws. Neurological: Other than presenting complaints, the patient denies dizziness, numbness, pins and needles, weakened muscles, and temporary loss of vision, smell, or hearing. Head & ENT, Cardiovascular, Respiratory, Gastrointestinal, Genitourinary, Endocrine, Derma./Hematological Issues, and Allergies all reported as normal.

Past, Family, and Social History:
- Past Health History: Surgery: None, Medications: None, Illnesses: Denies History of diabetes, cancer, hypertension. Accidents: single motorcycle accident- 2017,
Family and Social History: Family History: high blood pressure-mother, Employment Status: full time Social Habits: drinks alcohol and drinks caffeine, Exercise Habits: no exercise, Diet and Nutrition: no special regimen reported

The patient denies any numbness/tingling or bowel changes or control problems.

Exam:

The following are the initial exam findings:

Age/Gender/DOB: 21, Male, born 11/22/2000, Constitutional: average build, clean/neat, well-dressed and well-groomed, Vital Signs: Height: 5' 7" Weight: 178 lbs., Pulse: 75 bpm. BP: 126/66, mm/Hg left arm in the seated position. Temperature: Taken with skin surface scanner. 97.2 degrees Fahrenheit. Pulse Ox: 97%

The patient's appearance was generalized pain.

• Palpation: Centralized spinal pain was elicited upon palpation of the C3, C6, and L4 vertebrae. Palpation of the facet joints produced pain at C6.
• O'Donoghue's Test: Negative for both active and passive ROM.
• DeKlyn's and Maigne's Tests: Both tests were negative.
• Spurling's Test: No pain reported bilaterally.
• Shoulder Depression Test: No pain reported bilaterally.
• Soto Hall Test: No pain reported.
• Valsalva's Maneuver: No pain reported.
• Percussion (instrument-assisted): No pain reported in any area.
• Sternal Compression Test: Negative for substernal pain, rib cage pain, and thoracic spine pain.
• Straight Leg Raiser Test: Performed bilaterally, eliciting 7/10 pain (with 10 being the most severe) in the right lumbar region at 30 degrees, confirmed by palpation of the paraspinal muscles.
• Belt Test: Increased pain consistent with lumbar spine pain.
• Braggard's Test: No increase in radicular pain bilaterally.
• Minor's Sign: Within normal limits.
• Iliac Compression Test: Performed bilaterally, eliciting increased SI joint pain rated at 4/10 on the left.
• FABERE/Patrick's Test: No pain reported bilaterally.

• Babinski's Sign: Negative bilaterally.
• Hoffman's Sign: Negative bilaterally.
• Mental Status: Patient was evaluated and observed to be alert and oriented x 3 (person, place, time), and cooperative.
• Sensory-Pain: Evaluations performed bilaterally, with normal dermatomal findings across all upper and lower spinal segments.
• Elvey's Test: Negative bilaterally.

Neuro- Deep Tendon Reflexes (normal 2+):
- Biceps: Left 2+, Right 2+
- Triceps: Left 0, Right 2+
- Brachioradialis: Left 0, Right 0
- Patellar: Left 2+, Right 2+
- Achilles: Left 2+, Right 2+
Neuro-Upper extremity resistive isometric motor testing (normal 5/5):
- Shoulder Elevation: Left: 5 / 5 Right: 5 / 5.
- Deltoid: Left: 5 / 5 Right: 5 / 5
- Biceps: Left: 5 /5 Right: 5 /5
- Triceps: Left: 5 / 5 Right: 5 / 5
- Wrist Flexors: Left: 5 / 5 Right: 5 / 5
- Wrist Extensors: Left: 5 / 5 Right: 5 / 5
- Finger Abductors: Left: 5 / 5 Right: 5 / 5
- Palmar Interossei: Left: 5 / 5 Right: 5 / 5
Neuro-Lower extremity resistive isometric motor testing (normal 5/5):
- Iliopsoas: Left: 5 / 5 Right: 5 / 5
- Quadriceps: Left: 5 / 5 Right: 3 / 5
- Anterior Tibialis: Left: 5 / 5 Right: 5 / 5
- Biceps Femoris Left: 5 / 5 Right: 5 / 5
- Ext Digitorum Longus & Brevis: Left: 5 / 5 Right: 5 / 5
- Gluteus Medius: Left: 5 / 5 Right: 5 / 5

Neuro-Cranial Nerves: I to XII were examined, revealing normal function to the following: I through XII.

Musculoskeletal - Gait and Station: normal gait and normal balance
Musculoskeletal - Tonicity: moderate spasm right erector spinae and multifidus.

Physical Findings - Neck Tissue: Supple, non-tender, without cervical lymphadenopathy noted. The thyroid gland not palpable, without nodules. Otherwise, unremarkable findings.
Physical Findings - Skin: full body (arms, legs, trunk, and head/neck), head/neck and trunk: grossly normal, dry warm, without diaphoresis, depigmentation, or hyperpigmentation. No rashes, ulcers, or ecchymosis. No purple striae, no excessive hair or acne. Otherwise, unremarkable findings.

Radiographs:
Rationale: Radiographs were ordered based on the patient's history and examination. As routine procedure, the patient confirmed that there were no contraindications to taking radiographs, including but not limited to pregnancy, trying to become pregnant, receiving active radiation therapy, or other contraindication for X-ray exposure. The rationale was due to recent trauma, clinical need to visualize vertebral biomechanics, and neuromotor deficits.

Views: The radiographs were performed in the office in the standing (weight bearing) position with the following view(s): Davis Series, Thoracic-AP, Thoracic-Lateral, Lumbar-AP, Lumbar-Lateral, Lumbar-Forward Flexion and Lumbar-Extension.

- Curve Analysis: cervical spine: curve mild decrease and midline.
- Curve Analysis: thoracic spine: curve within normal limits and midline.
- Curve Analysis: lumbar spine: curve moderate increase and midline.
- Observation: spondylolysis - L5.
- Observation: Schmorl's nodes - all lumbar segments.
- Observation: there are no bone spurs or loss of disc heights - for areas visualized.

Biomechanical Studies:
A biomechanical radiographic examination of Mr. Patient's cervical, thoracic, and lumbar spine was performed using "Symverta" computerized range of motion analysis and was performed and found to be positive for grade 2 (partial avulsion) ligament sprain in the form of translation pathology measuring 2.7 mm at L5/S1. The ligaments damaged in this injury are ligamentum flava and facet capsule.

Intra and Inter-Rater Reliability Analysis of Symverta X-Ray Digitizing

To conclude an accurate diagnosis based on X-ray digitizing for spinal biomechanical pathology, accuracy must be established through inter and intra-rater reliability studies. Jain et al. 2013 wrote, "Repeatability is a measure of the consistency of a method. Kappa coefficient was used in this study to measure the level of agreement between raters. Kappa is calculated by subtracting the chance proportion of agreement from the observed proportion of agreement and dividing this value by a number that is one less than the chance proportion of agreement. The values for kappa usually lie between zero and 1; zero indicates no correlation better than chance agreement, and 1 indicates perfect agreement." Landis and Koch offered the interpretation of Kappa, as reflected in Table 1, which was used in this study on reliability.

Two participants were selected based on a sharp contrast in their backgrounds. The first is a doctor of chiropractic with a fellowship in primary spine care, formal training in spinal biomechanical engineering, and 42 years of experience, including reviewing tens of thousands of X-rays. The second participant has a two-year associate's degree in applied sciences but no background in medicine, chiropractic care, or spinal education.

Inter and Intra-Rater Methodology

Both participants were given flexion and extension X-rays of the lumbar spine, digitized using Symverta technology. The images selected were intentionally of poor quality to challenge participants in locating the precise points for digitization. The rationale behind this approach was that if accurate digitization can be achieved on lower-quality images, even greater accuracy should be attainable on high-quality images. The images utilized are posted in this report. They were instructed to analyze the images, with vertebrae identified for the layperson. Basic instructions were provided to the layperson on the anatomy of a vertebra, highlighting the four corners of each segment. The study focused on four points at the fourth lumbar segment: anterior-superior, anterior-inferior, posterior-superior, and posterior-inferior, in both flexion and extension. There are two components per point, the X and Y axis of the Cartesian Coordinate System, and 8 points were digitized, totaling 16 values to calculate with five passes per image. This totals 80 calculations per intra-rater and 160 calculations for inter-rater reliability to help determine accuracy.

To create an accurate scale from a Dicom image to a fixed distance, pixels in the image were converted to millimeters per pixel utilizing the scale line. The factor to convert pixels to millimeters was 0.4547595682041217 for the test image and extension. Each image has its own scale line and imaging factor to ensure accuracy and validation when converting pixels to millimeters. This system calibrates each image to itself versus a norm, ensuring a higher degree of accuracy.
Methodology to BaselineCalculating the margin of error that can be tolerated before it affects the accuracy of an X-ray digitizing platform must consider the following factors:

1. Pixel to Millimeter Conversion: Since your platform converts pixels to millimeters, even a small error in pixel selection (due to mis-clicks, resolution issues, or user variability) can lead to inaccuracies in the final measurement. First, we calculated the precision of the scale line in terms of millimeters per pixel. This establishes how much a single pixel shift affects measurements.
The formula for error calculation due to pixel shift:
Error (mm)=Pixel shift×(mmpixels)\text{Error (mm)} = \text{Pixel shift} \times \left( \frac{\text{mm}}{\text{pixels}} \right)Error (mm)=Pixel shift×(pixelsmm)
This gives the actual error in millimeters per pixel shift.
2. Inter-Rater and Intra-Rater Reliability: These refer to how consistent different users (or the same user) are at placing the points in the same position on the vertebrae. If there is significant variation between raters, it could indicate issues with the clarity of landmarks, tool sensitivity, or interface usability. You can measure the average difference in point selection across raters to quantify this variability.

• Inter-rater reliability measures the consistency between different users.
• Intra-rater reliability measures how consistent the same user is over multiple attempts.

The formula for reliability (in general) is based on an Intraclass Correlation Coefficient (ICC) for continuous measurements.
3. Zoom and Tool Precision: While zooming improves accuracy by allowing users to be more precise, you need to assess how much zoom affects pixel precision. For instance, as zoom increases, the precision should ideally improve because the number of pixels per millimeter changes. If the user zooms in a lot and still makes a mistake, the error in millimeters will be larger.

The formula for adjusting for Zoom:
Effective Error (mm)=Base Error Zoom Factor\text{Effective Error (mm)} = \frac{\text{Base Error}}{\text{Zoom Factor}}Effective Error (mm)=Zoom Factor Base Error
The zoom factor reduces the effective error if zoom is applied.
4. Angle Measurement Impact: Given that you're calculating the range of motion in degrees, any slight error in positioning vertebral corners will affect the angle calculations. Small positional errors can lead to relatively large angular discrepancies, especially for small angles of flexion or extension.
Approximate formula to determine the error in the range of motion based on point displacement:
Δθ≈ΔyL\Delta \theta \approx \frac{\Delta y}{L}Δθ≈LΔy
Where:

• Δθ\Delta \thetaΔθ is the angular error,
• Δy\Delta yΔy is the vertical displacement error (in mm),
• LLL is the length of the vertebra (or the distance between the two measured points).

5. Edge Detection Sensitivity: Using edge detection, its accuracy depends on the resolution and contrast of the image. A threshold deviation where the edge is misidentified due to noise or resolution limitations should be quantified.
6. Threshold of Acceptable Error: You can define an acceptable error based on clinical relevance. For example, if a 1mm error in detecting a vertebral corner leads to a change in the range of motion beyond 2 degrees, you might consider this the threshold beyond which the system is inaccurate.
Intra and Inter-Rater Calculations

The results revealed the average intra-rater reliability based on distance and magnitude, considering the X and Y coordinates, and using the above sensitivity tools in Symverta technology to be a difference of .001 utilizing five sets of images and 80 points. The results revealed the average inter-rater reliability based on distance and magnitude, considering the X and Y coordinates, and using the above sensitivity tools in Symverta technology to be a difference of .0.796683374 utilizing five sets of images and 160 points.

Both intra and inter-rater reliability results fall well within the threshold for acceptable error and confirming and accurate reporting.

Kappa Intra and Inter-Rater Reliability Discussion

The Kappa coefficient for inter-rater reliability revealed a score of 1.00 in agreement on diagnostic points and for all 80 calculations as accurately digitized. Inter-rater reliability scored 1.00 on all 160 calculations as accurately digitized.

ASSESSMENT:
Mr. Patient's prognosis is undetermined; treatment is indicated
Mr. Patient's case is of moderate diagnostic complexity

DIAGNOSIS:
Upon consideration of the information available, I have diagnosed Mr. Patient with (S29.012A) Strain of the back wall of thorax, (S39.012A) Strain of lower back, (M62.830) Muscle spasm of back, (M99.83) Biomechanical Lesion Lumbar spine, (S33.5XXS) Sprain of ligaments of lumbar spine, sequela, (S33.5XXAS) Sprain of ligament lumbar initial sequela, (M54.51) Vertebrogenic low back pain, (M54.59) Other low back pain,

Treatment: The patient received chiropractic adjustments, non-surgical spinal decompression, and low-level laser therapy.

Discussion
This case report highlights the complexity of managing lumbar spine injuries resulting from a motor vehicle crash, specifically involving the ligaments at the L5-S1 levels. The patient presented with significant damage to the facet capsule and ligamentum flava at that level, which contributed to both acute and chronic symptoms, including pain and functional limitations.

Mechanisms of Injury and Clinical Implications
The high-impact forces experienced in motor vehicle collisions can lead to substantial stress on spinal structures, particularly the ligaments that provide stability and support. The interspinous and supraspinous ligaments play crucial roles in limiting excessive spinal extension and maintaining segmental stability. The facet capsule, which encases the facet joints, contributes to spinal stability and proprioception. Damage to these ligaments disrupts normal spinal biomechanics and can lead to instability, pain, and compromised function.

Rehabilitation and Management
Treatment strategies for such injuries typically involve a combination of conservative and, when necessary, surgical approaches. In this case, the conservative management included pain control, chiropractic, and progressive rehabilitation aimed at restoring spinal function and stability. The importance of a comprehensive rehabilitation program, incorporating exercises to strengthen the surrounding musculature and enhance ligament healing, aligns with Dr. Mark Studin's approach to functional rehabilitation. His emphasis on restoring alignment and function underscores the necessity of addressing both the structural and functional aspects of spinal injuries.
Biomechanical and Stability Considerations

Integrating biomechanical insights into the management of lumbar spine injuries is crucial. Haavik's research into spinal biomechanics elucidates how disruptions in ligamentous structures affect overall spinal function and pain perception. The biomechanical strain placed on the L5-S1 level in this case likely contributed to the patient's symptoms and recovery challenges. Understanding these biomechanical principles helps guide treatment strategies and anticipate potential complications.
Panjabi's model of spinal stability, which includes the concepts of passive, active, and neural control systems, is particularly relevant. The damage to the passive stabilizers (ligaments) necessitates a greater reliance on the active (musculature) and neural (proprioceptive) systems to maintain spinal integrity. Rehabilitation efforts should therefore focus on enhancing these systems to compensate for the compromised ligaments and restore overall spinal stability.
Outcomes and Future Directions

The patient's recovery was marked by a gradual reduction in pain and improvement in functional outcomes, demonstrating the effectiveness of a multidisciplinary approach. This case underscores the need for individualized treatment plans that address both the specific ligamentous injuries and the broader implications for spinal stability and function.

Future research should explore optimized rehabilitation protocols and long-term outcomes for patients with similar injuries. Continued investigation into the role of ligamentous damage in spinal stability and the effectiveness of various management strategies will enhance our understanding and improve treatment approaches for lumbar spine injuries.

Conclusion
In conclusion, this case illustrates the complex nature of managing lumbar spine injuries from motor vehicle collisions. By integrating insights from biomechanical research and rehabilitation strategies, we can better address the multifaceted challenges of such injuries and improve patient outcomes.

References:
1. Mark Studin DC, Don Capoferri DC, Paul Birinyi MD, Patricia Roche DO, Geoffrey Gerow DC. "Lumbar Disc Herniation and Biomechanical Dysfunction - A Case Study. Discussion of - The Outcome Assessment of Physical Therapy And Chiropractic Spinal Adjustments On Low Back Pain, Opioid Use, and Health Care Utilization," Medpix: National Institute of Health/National Library of Medicine, Published March 3, 2024.
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Integration
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A-P Lumbo-Pelvic X-ray Study

Demonstrates no fracture or dislocation about the pelvis, maintained and symmetric sacroiliac joint spaces, slight symmetric bilateral hip joint space loss, maintained pubic symphysis, and minimal rightward curvature of lumbar spine. 

Neutral Lateral Lumbo-Sacral Study

Demonstrated maintained lumbar lordosis, maintained lumbar veterbral body heights, moderate loss of disc height at L4/L5 with anterior and posterior osteophytes. 

Lumbar Lateral Flexion Study

Demonstrated moderate loss of disc spaces at L4/L5. With anterior osteophytes at  L4 and L5 and endplate sclerosis at the inferior endplate of L5 and superior endplate of L5.

Lumbar Lateral Extension

Demonstrates moderate loss of disc height at L4/L5 and worse at L5/S1,  with endplate sclerosis at L4 and L5.  Anterior osteophytes at seen at L4 and L5.  Degeneration of the L4/L5 facet is also seen.

Reliability study image #1 with points plotted

Reliability Study Image #2 with points plotted