Spatial mapping of humeral head bone density

Abstract

BackgroundShort-stem humeral replacements achieve fixation by anchoring to the metaphyseal trabecular bone. Fixing the implant in high-density bone can provide strong fixation and reduce the risk of loosening. However, there is a lack of data mapping the bone density distribution in the proximal humerus. The aim of the study was to investigate the bone density in proximal humerus.MethodsEight computed tomography scans of healthy cadaveric humeri were used to map bone density distribution in the humeral head. The proximal humeral head was divided into 12 slices parallel to the humeral anatomic neck. Each slice was then divided into 4 concentric circles. The slices below the anatomic neck, where short-stem implants have their fixation features, were further divided into radial sectors. The average bone density for each of these regions was calculated, and regions of interest were compared using a repeated-measures analysis of variance with significance set at P < .05.ResultsAverage apparent bone density was found to decrease from proximal to distal regions, with the majority of higher bone density proximal to the anatomic neck of the humerus (P < .05). Below the anatomic neck, bone density increases from central to peripheral regions, where cortical bone eventually occupies the space (P < .05). In distal slices below the anatomic neck, a higher bone density distribution in the medial calcar region was also observed.ConclusionThis study indicates that it is advantageous with respect to implant fixation to preserve some bone above the anatomic neck and epiphyseal plate and to use the denser bone at the periphery.

Subscapularis Management in Total Shoulder Arthroplasty: Current Evidence Comparing Peel, Osteotomy, and Tenotomy

“…7,[25][26][27][28] Repair is carried out using tendonto-tendon repair with a Mason-Allen suture technique, tendon-to-bone repair through transosseous tunnels in the bicipital groove-which is comprised of relatively dense bone-or a combination of these techniques. 6,27,29,30 Biomechanical testing has not demonstrated a clear superiority of 1 repair technique. 26,27,31,32 SSC tenotomy has been the most commonly used approach to access the glenohumeral joint.…”

Anatomic total shoulder arthroplasty using a stem-free ellipsoid humeral implant in patients of all ages

“…2) places the implant onto bone more proximally, which has been shown to have higher density and is recommended by other researchers as a preferred location for implant fixation. 1,31,50 Longer-term studies and continued surveillance of this group are necessary to validate this fixation strategy over time.…”

Arthroscopic Onlay Articular Margin Biceps Tenodesis for Long Head of the Biceps Tendon Pathology

“…Second, this technique fixes the suture anchor within the articular margin at the top of the biceps groove, a region of particularly high bone density in the humerus. 10 Consequently, the mode of failure for this technique involves the suture knot pulling through the tendon rather than implant pullout from bone seen with subpectoral and suprapectoral tenodesis, theoretically avoiding this common latter complication. 8 Third, this technique can be performed through 2 or 3 small portals and may be less technically demanding than other approaches as intra-articular visualization is maintained using only a standard posterior portal and landmarks for tenodesis are easily identifiable.…”