Age-related joint space narrowing independent of the development of osteoarthritis of the shoulder.

PURPOSE: It is commonly accepted that the glenohumeral joint space remains unchanged until the onset of osteoarthritis, at which point progressive degenerative changes, and joint space narrowing occur. The aim of this study was to evaluate the radiographic width of the glenohumeral joint space in patients of different ages: Those with otherwise normal radiographs, those with a history of instability, those with calcific tendonitis, and those with a radiologic diagnosis of osteoarthritis. MATERIALS AND METHODS: In this retrospective study, two independent investigators measured the glenohumeral joint width on true anteroposterior and axillary views of standardized shoulder radiographs taken from 2002 to 2009. The digital image resolution was 0.01 mm. Group I comprised 60 patients with normal shoulder radiographs, Group II comprised 53 patients with instability but normal radiographs, Group III comprised 109 patients with radiologically proven calcific tendonitis, and Group IV comprised 120 patients with manifest osteoarthritis. RESULTS: The interobserver reliability (r) was 0.621-0.862. The mean joint space width was significantly different among Groups I-IV (central anteroposterior: 4.28 ± 0.75 mm, 3.12 ± 0.73 mm, 2.87 ± 0.80 mm, and 1.47 ± 1.07 mm, respectively; P = 0.001; central axillary: 6.12 ± 1.09 mm, 3.92 ± 0.77 mm, 3.34 ± 0.84 mm, and 1.08 ± 1.12 mm, respectively; P = 0.001). There was a significant negative correlation between the joint space width and age at all measured levels in both projections (P < 0.001). CONCLUSIONS: The glenohumeral joint space width decreases with increasing age beginning in early adulthood, and this effect is enhanced by osteoarthritis. LEVEL OF EVIDENCE: Level II, retrospective study.

Do anatomic variants of the acromion shape in the frontal plane influence pain and function in calcifying tendinitis of the shoulder?

PURPOSE: To evaluate the relationship of a large acromion index and calcifying tendinitis of the supraspinatus tendon at the shoulder. MATERIALS AND METHODS: Between 2002 and 2008, 109 consecutive patients with isolated calcifying tendinitis of the supraspinatus tendon were prospectively analysed by clinical investigation and standardized radiographs. Deposit size and appearance were measured and classified according to Bosworth and Gartner. The acromion index (AI) was calculated based on measurements on true anteroposterior radiographs. Pain record on VAS scale, active and passive range of motion and the constant score (CS) were recorded. RESULTS: The mean age of the patients was 48.2 ± 8.0 (n = 46 male 48.6 ± 7.3; n = 63 female 47.9 ± 8.6; P > 0.05). Pain and function were not significantly correlated with deposit size or classification. The acromion index (mean 0.64 ± 0.08) was not significantly correlated with the affected or dominant side, gender, deposit size or classification or any functional parameter like pain and the CS or its subgroups. CONCLUSION: The theoretical concept of a high acromion index resulting in an increased resulting upward force against the subacromial space, which influences pain and function in calcifying tendinitis of the shoulder, was not supported.

How much are radiological parameters related to clinical symptoms and function in osteoarthritis of the shoulder?

Loss of joint space, formation of osteophytes and deformation are common features of osteoarthritis. Little information exists about the radiological features of arthrosis in relation to clinical findings and the radiological appearance in degenerative shoulder joint disease especially with regard to decision making about the timing of joint replacement. We retrospectively examined 120 standardised X-rays of patients with advanced osteoarthritis of the shoulder. Exclusion criteria included rotator cuff tear, severe glenoid erosion or protrusion. Measurements of joint space width at three levels in each plane (anteroposterior and axillary view), humeral head diameter and size of humeral osteophytes were made by two independent examiners. Osteoarthritis was graded according to Samilson and Prieto. Seventy-five of these patients had a complete record from the clinical investigation (pain record on VAS scale, active and passive range of motion) and the constant score (CS). Mean joint space width in the central anteroposterior level was 1.46 mm +/- 1.08 and in the central axillary 0.98 mm +/- 1.02. Increasing age was positively correlated with joint space narrowing at all measured levels. The joint space width was not correlated with the Samilson grade or the size of osteophytes. The joint space width was neither correlated with pain nor active or passive ROM. Pain was correlated with active and passive flexion and abduction but not for internal or external rotation. The size of the osteophytes was negatively correlated (active and passive) with flexion, abduction and external and internal rotation. The study illustrates that joint space narrowing and development of osteophytes are reliable but independent parameters of primary shoulder arthrosis and should be recorded separately. The size of the caudal humeral osteophyte is a predictive factor for function and should be taken into account for clinical decision making. The primary clinical feature, pain, as the main indication for surgery is not related to radiological parameters.

Is there an association between a low acromion index and osteoarthritis of the shoulder?

The aim of this study was to evaluate the relationship between a low acromion index and osteoarthritis of the shoulder. Three patient groups were used: (I) instability, n = 53; (II) calcifying tendonitis, n = 109; and (III) osteoarthritis, n = 120. Standardised digital X-rays were evaluated from the true anteroposterior and axillary views. Joint space width at three levels in each plane and the size of humeral osteophytes were measured and osteoarthritis was graded according to Samilson. The acromion index was calculated according to Nyffeler et al. (J Bone Joint Surg Am 88:800-805, 2006) in the true anteroposterior view. There were two independent investigators. Interobserver reliability was excellent for all measurements in the anteroposterior (AP) projection but inferior in the axillary projections, especially in group III. The mean acromion index was 0.64 ± 0.07 in group I, 0.64 ± 0.08 in group II and 0.73 ± 0.12 in group III. The acromion index was not correlated with the joint space width nor with the size of the osteophytes or the Samilson grading in group III. The data of the study did not show a significant association between a low acromion index and typical signs of osteoarthritis at the shoulder. The theoretical concept of a small acromion index associated with the development of osteoarthritis of the shoulder is not supported.