Single-radius, multidirectional total knee replacement.

PURPOSE: The present study was designed to evaluate the mid-term (5- to 8-year) survival rate of a new total knee replacement (TKR) with a single-radius femoral component and a multidirectional, highly congruent tibial component, in comparison with an historical group (TKR with multi-radius design and fixed bearing). METHODS: Four hundred and thirty patients were included, of which 369 patients (86 %) completed the 5-year follow-up with Knee Society Score evaluation and radiograph examination (study group = 387, control group = 83). RESULTS: There was a significant improvement for all analysed items between pre-operative status and late follow-up. Mean knee score was 93 ± 9 points in the study group and 88 ± 16 points in the control group (p < 0.001). Mean flexion angle was not different (118 ± 11 vs. 114 ± 13 degrees). Mean functional score was 87 ± 16 points in the study group and 71 ± 24 points in the control group (p < 0.001). Survival rate at 5-year follow-up was 98.8 % (vs. 98.0 %) for mechanical revisions only, and 96.4 % (vs. 98.1 %) for all revisions. CONCLUSIONS: The new TKR allowed obtaining significantly better results than the fixed-bearing TKR. These results are in line with the best series published in the current literature, but there was no evidence of any superiority of this TKR against already published standards.

An association between the inferior humeral head osteophyte and teres minor fatty infiltration: evidence for axillary nerve entrapment in glenohumeral osteoarthritis.

BACKGROUND: Glenohumeral osteoarthritis often results in inferior humeral osteophytes. Anatomic studies suggest that the axillary neurovascular bundle is in close proximity to the glenohumeral capsule. We therefore hypothesize that an inferior humeral osteophyte of sufficient magnitude could encroach on the axillary nerve and result in measurable fatty infiltration of the teres minor muscle. MATERIALS AND METHODS: Preoperative magnetic resonance imaging studies of 91 consecutive arthritic shoulders were retrospectively reviewed. Two cohorts were established based on the presence of a humeral osteophyte. The distances from the axillary neurovascular bundle to various osseous structures were measured using calibrated software. Objective quantitative measurements of the degree of fatty infiltration of the teres minor muscles were obtained with image analysis software. Results were compared between cohorts. RESULTS: The distance between the inferior humerus and axillary neurovascular bundle was inversely correlated to the size of the inferior humeral osteophyte (ρ = -0.631, P < .001). Fatty infiltration of the teres minor was greater when an inferior osteophyte was present (11.9%) than when an osteophyte was not present (4.4%) (P = .004). A statistically significant correlation between the size of the humeral head spur and quantity of fat in the teres minor muscle belly (ρ = 0.297, P = .005) was identified. CONCLUSION: These data are consistent with our hypothesis that the axillary nerve may be entrapped by the inferior humeral osteophyte often presenting with glenohumeral osteoarthritis. Entrapment may affect axillary nerve function and lead to changes in the teres minor muscle. Axillary neuropathy from an inferior humeral osteophyte may represent a contributing and treatable cause of pain in patients with glenohumeral osteoarthritis.

Reconstruction of posterior glenoid deficiency using distal tibial osteoarticular allograft.

Posterior shoulder instability with glenoid deficiency is a rare entity and its surgical treatment is challenging. Reconstructive techniques have focused on extra-articular structural bone transfer that obstructs humeral translation and thereby prevents glenohumeral dislocation. However, long-term results are not as promising. In this report, the authors describe a technique for anatomic posterior glenoid reconstruction using an osteoarticular distal tibia allograft in two patients including their outcomes after 2 years. Level of evidence IV.