Summary

The findings suggest that SPECT/CT is a promising tool for the early detection and localisation of chondral lesions in the knee joint, particularly in cases where standard imaging fails to reveal chondral abnormalities or do not correlate with the patients’ symptoms.

Abstract

Background

Single-photon emission computerised tomography with conventional computer tomography (SPECT/CT) is an innovative imaging tool which may enhance the clinical evaluation of chondral lesions in the knee joint. The intensity and distribution of SPECT/CT uptake tracer may offer physiological and structural insight by potentially detecting chondral lesions, or areas of inferior cartilage quality, prior to structural changes that other standard imaging modalities, such as MRI, may overlook. Thus, SPECT/CT is particularly valuable for diagnosing and managing chondral lesions, particularly when no cartilage abnormality is visible on other modalities.

Objectives: This systematic review aims to evaluate the effectiveness of SPECT/CT to identify chondral lesions in the knee joint of patients experiencing knee pain, with or without accompanying structural changes.

Methods

The following databases were systematically searched for relevant articles: PubMed, Science Direct, Web of Knowledge, MEDLINE, CINAHL, AMED, Ovid Emcare and Embase. Eligible articles included those focusing on the diagnostic value of SPECT/CT concerning knee chondral lesions and associated knee pain. Studies were limited to English language to ensure clarity, while animal studies, cadaver research, imaging techniques other than SPECT/CT, and studies involving pathologies unrelated to knee chondral lesions were excluded. Additionally, studies involving patients who had undergone knee arthroplasty were also excluded. Each included study was independently assessed for bias using the QUADAS-2 tool, focusing on the quality of the research undertaken. Study results were synthesised narratively, with conclusions drawn from the common themes across the studies.

Results

A total of 11,982 manuscripts were initially identified, from which seven studies met the inclusion criteria and demonstrated low bias according to QUADAS-2 assessment. Key findings included:
- Tracer uptake measured by SPECT/CT often aligned with the knee pain location reported by patients. In certain cases, chondral lesions were discovered by SPECT/CT in regions located away from the pain site.
- SPECT/CT uptake correlated with ICRS scores during arthroscopic evaluations of chondral lesions.
- Compared to planar imaging techniques, SPECT/CT had superior capabilities in detecting, localising, and characterising chondral lesions than bone scintigraphy.
- SPECT/CT exhibited a significant correlation with chondral lesion size and grade when compared to MRI, specifically identifying 29 regions of cartilage lesions that MRI classified as normal.

Conclusion

The findings suggest that SPECT/CT is a promising tool for the early detection and localisation of chondral lesions in the knee joint, particularly in cases where standard imaging fails to reveal chondral abnormalities or do not correlate with the patients’ symptoms. Further research is essential to thoroughly evaluate the diagnostic capacity of SPECT/CT and to clarify its potential role in clinical decision-making regarding chondral lesions in the knee.