Radiographic joint space in rheumatoid elbow joints. A 15-year prospective follow-up study in 74 patients.

OBJECTIVE: To evaluate radiographically the humeroulnar (HU) and humeroradial (HR) joint spaces in patients with long-term rheumatoid arthritis (RA). METHODS: An inception cohort of 74 patients with RA were followed for 15 yr. At the end-point, 148 elbows were radiographed by a standard method. The HU and HR joint spaces were examined from the anteroposterior radiographs by measuring the shortest tangential distance in the middle of the joints. Destruction of the elbow joints, assessed with the Larsen method on a scale of 0-5, was studied in relation to the joint-space measurements. RESULTS: Mean (s.d.) HU joint space (n=148) in RA patients was 2.5 (1.1) mm, range 0-4 mm [2.9 (0.8) mm in men and 2.4 (1.1) mm in women]. Mean (s.d.) HR joint space (n=140) was 2.3 (0.9) mm, range 0-4 mm [2.5 (0.8) mm in men and 2.3 (1.0) mm in women]. HU and HR spaces of the affected joints (Larsen grades 2-5) [1.9 (s.d. 1.1) and 1.8 (0.9) mm respectively] were notably narrower than those of the unaffected (Larsen grades 0-1) joints [3.1 (0.7) and 2.9 (0.6) mm]. All the joints graded as Larsen 4 or 5 (n=13) had a value of 0 mm for both joint spaces. Both the HU and the HR joint-space narrowing was associated with increasing destruction (Larsen grading) of the joint. [r= -0.69 (95% CI -0.77 to -0.60) and r= -0.70 (-0.78 to -0.60)]. The monotonic narrowing was significantly increasing from unaffected (Larsen 0, 1), slightly (2), moderately (3) to severely (4, 5) affected joints (P<0.001). A step in this process occurred between Larsen grades 3 and 4, when the mean joint space diminished from 1.4 and 1.5 respectively to 0 mm. CONCLUSIONS: Joint-space narrowing is a frequent consequence of rheumatoid affection of the elbow joint. HR joint space decreases together with HU joint space; however, the HR joint space is already slightly narrower at the start. The narrowing is a rather late phenomenon, occurring only after erosive destruction. This should be borne in mind when using the Larsen method to evaluate changes in the elbow joint.

Bone destruction, upward migration, and medialisation of rheumatoid shoulder: a 15 year follow up study.

OBJECTIVE: To evaluate bone destruction, upward migration, and medialisation of the glenohumeral (GH) joint in a cohort of 74 patients with seropositive and erosive rheumatoid arthritis followed up prospectively. METHODS: At the 15 year follow up 148 shoulders were radiographed by a standard method. Bone destruction in the GH joint was examined from the radiographs by four methods, of which three measured the migration and one the remodelling of the humeral head. The distances from the greater tuberosity of the humeral head to the coracoid process (medialisation distance (MD)) and to the articular surface of the humeral head (GA) have been previously developed to evaluate the preoperative offsets of the arthritic GH joint. Medial displacement index (MI) and upward migration index (UI) have been recently developed to evaluate the destructive pattern of the rheumatoid GH joint. Destruction of the GH joints was assessed by the Larsen method on a scale of 0 to 5. The relation between the measurements and the grade of destruction of the GH joints was examined. UI was compared with our previous measurements of the subacromial space. RESULTS: Both the MI and the UI had a negative correlation with the GH joint destruction (Larsen grade), r=-0.49 (95% CI -0.36 to -0.60) and r=-0.58 (95% CI -0.46 to -0.68). The UI correlated significantly with the subacromial space, r=0.90 (95% CI 0.86 to 0.93). The mean MI and UI measurements of the non-affected joints were within the reported normal variation. The mean MD collapsed between Larsen grades 4 (83.0 mm) and 5 (65.5 mm). The morphology of the humeral head began to flatten and erode from the grade 3 onwards and medial head destruction was detected at grade 5. CONCLUSIONS: Medialisation seems to be preceded by upward migration of the humeral head, indicating rotator cuff damage. Symptomatic Larsen grade 3 shoulders should be intensively followed up by clinical and radiological means. If a total shoulder arthroplasty is considered, an orthopaedic consultation is worthwhile at a sufficiently early stage (Larsen 3 and 4), when soft tissue structures responsible for function are still in proper condition and timing of the operative procedure can be well planned.

Incidence of elbow involvement in rheumatoid arthritis. A 15 year endpoint study.

OBJECTIVE: To evaluate the incidence of involvement and cause of destruction of humeroulnar (HU) and humeroradial (HR) joints in a prospectively followed cohort of 74 patients with seropositive and erosive rheumatoid arthritis (RA). METHODS: At the 15 year followup standard anteroposterior and lateral radiographs of 148 elbow joints were evaluated, and the grade of destruction was assessed by the Larsen method. RESULTS: Erosive involvement (Larsen grade 2) was observed in 75/148 (51%) elbows in 45/74 (61%) patients; 30 patients had bilateral and 15 unilateral involvement. The incidence of mild erosions (Larsen grade 2) was 49/148 (33%), and severe erosions (Larsen 3-5) 26/148 (18%). The 13 most severely involved (Larsen grade 4-5) joints were seen in 8 (11%) patients. Erosions were most often observed on the capitellum (64 joints) and the lateral epicondyle (58 joints) of the humerus (AP view) or on the olecranon of the ulna (52 joints). The Larsen score (0-100) for peripheral joints correlated significantly with the elbow joint Larsen grade on both sides: right, r = 0.53 (95% CI 0.34 to 0.68); left, r = 0.53 (95% CI 0.34 to 0.68). CONCLUSION: After 15 years more than half of the elbows and almost 2 of 3 patients with RA showed definite involvement of the elbow joint. Erosions were most often located on the capitellum and the lateral epicondyle of the humerus or the olecranon of the ulna. Severe destruction was most often bilateral.