The Basics of Image Interpretation in Arthroplasty Jill Pope Clinical Physiotherapy Specialist

The Basics of Image Interpretation in Arthroplasty Guidelines, Regulations and Protocols What are we looking for? Post operative Complications Conclusions

Guidelines, Regulations & Protocols Development of critical thinking skills to meet the changing needs of healthcare Ensure that our professional knowledge, skills and performance are of a high quality, up to date and relevant to our field of practice Practitioner needs Meet the standards of our professional regulatory body

Guidelines, Regulations & Protocols Demonstrate the behaviours, skills and knowledge to fulfil the responsibilities of their role. Work within their scope of practice Workplace needs: Quality Assurance Standards for Practitioners Deliver a safe and effective service. Practitioners should always be aware of their limitations.

Guidelines, Regulations & Protocols IR(ME)R: Ionising Radiation (Medical Exposure) Regulations Local Agreements: with Radiologists Local Protocols: with Consultant Surgeons

Guidance for non-medical healthcare professionals Published November 2006

Guidelines, Regulations & Protocols Principles of Radiation Principles of Radiation protection Regulations: (IRR)99 IR(ME)R 2000:Ionising Radiation (Medical Exposure) Regulations

Regulations Ionising Radiation Regulations (IRR) 99 IRR 99: This sets out the basic safety standards for the protection of the worker and general public against hazards arising from the occupational use of ionising radiation. The Health and Safety Executive is responsible for IRR99.

Regulations Ionising Radiation for (Medical Exposures) Regulations 2000 This legislation relates to the roles and responsibilities of individuals who refer for imaging and those who carry out the imaging Introduced the main principles of: Justification Optimisation Dose Limitation

Regulations Roles in Accordance with IR(ME)R 2000 The Employer – must provide a framework under which medical exposures may take place; The Referrer – must provide adequate and relevant clinical information to enable the practitioner to justify the exposure; The Practitioner – decides upon the appropriate imaging and justifies any exposure to radiation; The Operator – authorises and undertakes the exposure with regard to dose optimisation.

Regulations: Justification Regulation 6(1)(a) requires that exposures can only be carried out when justified by the practitioner. The practitioner is responsible for the justification of each individual medical exposure. This should be based on his/her knowledge of the hazard associated with the exposure and the clinical information supplied by the referrer.

Regulations: IR(ME)R 2000 for Radiographers The implementation of IR(ME)R 2000 also brought about changes to radiographers’ responsibilities, with the most significant being: In law, the responsibility for a patient’s radiation dose changed from the referrer to the individual who justifies the examination (ie Radiographer/Radiologist). Thus, ALL radiographers have to ensure each examination is justified.

Regulations: Justification The request form is a LEGAL DOCUMENT It must be signed and dated. It must include: The correct patient details Correct and relevant clinical information Current clinical condition of the patient (if relevant) All of the above is required in order for the practitioner to justify the request.

Regulations: Optimisation (ALARA) Need to have and maintain an environment where the level of ionising radiation is ‘safe’ for both workers and patients. All operators (radiographers, radiologists or assistant practitioners) adhere to the ALARA principle, whereby all radiation exposures are to be kept: As Low Reasonably Achievable.

Local Agreements Agreements between the Radiology Department and other Departments and/or Directorates regarding who may refer for Image Investigations and which investigations Agreement or signing off regarding training and competencies and evidence of knowledge and competencies for those who may refer.

Local Agreements: Providing the evidence IR(ME)R Formal training Evaluation tools Presentations Case studies Written critical reflections Comparison studies Audit

Local Protocols Local protocols which have been agreed between service users and the Radiology Department regarding views for a given joint or area Protocols give by individual Consultants / Teams regarding time intervals for Image Investigations

Standard Hip Imaging For trauma: AP pelvis and a horizontal beam lateral (HBL) of the affected hip For generalised pain/? degenerative change AP Pelvis or single AP hip (usually age dependent) For follow up of Hemiarthroplasty/THR AP Pelvis and lateral-oblique (AP maybe performed with patient weight bearing)

Standard Knee Projections For degenerative disease: AP/PA (weight bearing) Turned/weight bearing lateral +/- skyline view For trauma: AP (non-weight-bearing) horizontal beam lateral (HBL)

Reporting and Interpretation Medical Image interpretation by radiographers: Guidance for radiologists and healthcare providers Published 2010 RCR Explains the principles of image interpretation and the role of non-medically qualified role extended practitioners in the reporting of image investigations

Reporting and Interpretation Published in 2011 Gives clear standards for reporting and interpretation by non-radiologist medically qualified practitioners. Standard 3: All imaging investigations are best reported by a radiologist

Reporting and Interpretation Standard 2: ‘All imaging investigations must be accompanied by a formal permanently recorded written report’. This report is a legal document

What are we looking for? Interpretation – The ABCs Appropriate Alignment Bone density Cartilage space increase/loss/erosions Soft tissues swelling/calcification/gas

What are we looking for? Interpretation – CAST Appropriate Cortical Outlines Alignment Sclerosis and Lucency Trabecular Pattern Polyethylene wear

What are we looking for? Appropriate

What are we looking for? Alignment (Pelvis) 1:Shenton’s Line: Curve of lower border of superior pubic rami and inferior aspect of the Neck of Femur should form a smooth arc 2:Pubic Rami: Superior aspect of the superior pubic rami should line up.

What are we looking for? Alignment (Pelvis) Polyethylene wear

What are we looking for? Alignment (Pelvis) Hardware failure

What are we looking for? Alignment: Knee

What are we looking for? Alignment: Knee Ligament instability

What are we looking for? Cortical outlines: no irregularities

What are we looking for? Sclerosis and Lucency Any part of the bone that appears whiter than the surrounding areas of bone Can be due to impacted fragments or thickening of bone Lucency This refers to any part of the bone that appears darker than the surrounding areas. Usually due to separation of fragments or presence of cysts

What are we looking for? Sclerosis An example of sclerosis: Pedestal formation

What are we looking for? Lucency

What are we looking for? Lucency Perioperative fracture

What are we looking for: Lucency ( and hetertrophic bone)

Gruen and DeLee Zones

THE KNEE SOCIETY ARTHROPLASTY EVALUATION AND SCORING SYSTEM

What are we looking for? Spacer dislocation

What are we looking for? Trabecular pattern This refers to the appearance of the inner matrix of the bone. Any disruptions to the normal pattern can indicate a fracture or presence of a pathology

Post operative Complications Early Improper placement of prosthesis Dislocations-3%(hip) Fracture revision arthroplasty poor bone stock Cement extrusion Haematoma and infection Late Loosening: aseptic infection particle disease Hardware failure fracture, dislocation Periprosthetic Fracture Heterotrophic ossification

Conlusions: Indications for referral The indications for PFR post arthroplasty can be divided into three groups: the patient who has clinical signs of septic loosening i.e. pain at rest, stiffness, heat and redness, the patient who is due for clinical and radiological review as per the protocols agreed by the surgeons performing TKR/THR at the author’s place of work, the patient who has symptoms of pain, stiffness or instability in the hip/knee following trauma to the lower limb. the patient who has developed symptoms of pain, stiffness and instability without trauma.

Conclusions: Always remember……. Always compare with previous films Get maximum information about the surgical procedure Images should be interpreted in the light of clinical information Do not compromise on the quality of the image Look at the whole image not the prosthesis only ALWAYS BE AWARE OF YOUR LIMITATIONS IF IN DOUBT SEEK ADVICE/HELP

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