Radiographic Assessment of the Robert and Lateral Views in Trapeziometacarpal Osteoarthrosis

To evaluate the effectiveness of the Robert view in assessing trapeziometacarpal arthrosis and to compare the accuracy of the Robert and lateral views in staging trapeziometacarpal (TM) joint arthrosis.

Patient demographics were obtained. Four participating raters reviewed 62 randomly selected thumb x-rays of patients presenting with thumb TM joint pain. Lateral and Robert-hyperpronation views were assessed using an analysis of 13 criteria.

X-rays of 62 thumbs for 58 patients were evaluated. The average patients' age was 64 (47-87) and 51 (80%) were females. The majority of X-rays evaluated fell into stage 3. Stage 2 was the second most common level of arthritis encountered and the least was stage 1. More osteophytes were encountered in the trapezium than metacarpal on both the Robert and lateral views. The Robert view was superior in detecting osteophytes on the trapezium than the lateral view. Osteophyte size varied from 1.7 to 2 mm. The lateral view displayed 61 cases with dorsal metacarpal subluxation (98%). The Robert view displayed 48 cases (77%) with radial metacarpal subluxation and 9 cases (15%) with ulnar metacarpal subluxation. Thumb metacarpal adduction deformity was encountered on the lateral view in 20 cases (32%) whereas on the Robert view it was encountered in 14 cases (23%). Subchondral sclerosis was encountered on the Robert view in 56 thumbs (90%) while it was seen on the lateral view in 52 thumbs (84%). Pantrapezial arthritis involving the STT joint was encountered equally in 16 cases (26%) on the Robert view and the lateral views. The study found a moderate level of interrater reliability on both the lateral and Robert views. With the exception of osteophytes encountered on the trapezium versus the metacarpal, there were no other statistically significant findings.

This study confirms that each of the Robert and lateral views offer unique information and combining both views enhances the ability to assess radiographic disease severity, and should be the recommended set of X-rays for assessing TM osteoarthrosis.