Consequences of reaming with flat and convex reamers for bone volume and surface area of the glenoid; a basic science study

Rotator Cuff Tears to Shoulder Instability: The Relationship Between Acromial Morphology and Shoulder Pathology

» The acromion is a well-studied region of the scapula that has demonstrated substantial relationships to various shoulder pathologies.» Abnormal acromial morphology is associated with rotator cuff pathology, and our understanding of this risk factor inspired acromioplasty as an adjunctive treatment for rotator cuff tears.» The acromion is linked closely to shoulder kinematics and biomechanics, as it serves as the origin for the deltoid muscle.» In degenerative shoulder disease, eccentric glenohumeral osteoarthritis has been associated with a higher, flatter acromial roof.» Increasing literature is emerging connecting morphology of the acromion with shoulder instability.

Limited value of current shoulder arthroplasty registries in evidence-based shoulder surgery: a review of 7 national registries

National shoulder arthroplasty registries are currently used to assess incidence, indication, type of prosthesis and revision, but they seem to lack sufficient information to lead to evidence based decision-making in shoulder surgery. There appears to be a large difference in registered parameters and outcome measurement per country. First we investigated whether existing registries have sufficient common datasets to enable pooling of data. Second, we determined whether known risk factors for prosthetic failure are being recorded. Through a non-systematic literature review studies on registries were analyzed for included parameters. Seven national registries were scrutinized for the data collected and these were classified according to categories of risk factors for failure: patient-, implant and surgeon related, and other parameters. This shows a large heterogeneity of registered parameters between countries. The majority of parameters shown to be relevant to outcome and failure of shoulder prostheses are not included in the studied registries. International agreement on parameters and outcome measurement for registries is paramount to enable pooling and comparison of data. If we intend to use the registries to provide us with evidence to improve prosthetic shoulder surgery, we need adjustment of the different parameters to be included.

A 3-dimensional comparison of hand and power reamers in accuracy of glenoid retroversion correction

BACKGROUND

The study objective was to compare the reaming congruency of hand, power, and visual feedback axial alignment-guided (Marksman) reamers on glenoid models. We hypothesized that (1) a significant difference in average reaming deviation would be found between reamer types and (2) less ream-to-ream variation would occur with the Marksman reamer.

METHODS

Retroversion correction of 18 identical Sawbones glenoid models was conducted using either a hand, power, or Marksman reamer with a 40-mm curvature radius. Glenoid correction with either 0° or 10° reaming was conducted in triplicate sets for each reamer. Reamed glenoid computed tomography images were 3-dimensionally reconstructed using Mimics Medical software (version 21.0). Congruency between the glenoid surface and a 3-dimensional sphere with a 40-mm curvature radius was analyzed. Average deviation and ream-to-ream variance were compared between the hand, power, and Marksman reamer groups.

RESULTS

The power reamer demonstrated the smallest median deviation (0.08 mm; interquartile range [IQR], 0.07-0.19 mm), followed by the Marksman (0.09 mm; IQR, 0.08-0.17 mm) and hand (0.11 mm; IQR, 0.10-0.13 mm) reamers. Kruskal-Wallis analysis indicated no significant difference in deviation among the 3 reaming methods (P = .42). The Marksman reamer demonstrated the least variance (0.0034 mm), followed by the power (0.0076 mm) and hand (0.0093 mm) reamers. The results of the Conover squared ranks test indicated no significant difference in variance among the 3 reaming methods (P = .32).

CONCLUSION

Our findings showed no statistically significant difference in the accuracy or consistency of reaming between reamer types. Trends showed less variance in the Marksman reamer group compared with the hand and power reamer groups, although differences in variation between groups were not statistically significant.