Bouacida Soufyane, Gauci Marc-Olivier, Coulet Bertrand, Lazerges Cyril, Cyteval Catherine, Boileau Pascal, Chammas Michel
Department of Orthopedic Surgery of the Upper Limb, Hand Surgery and Peripheral Nerves Surgery, Lapeyronie Hospital, Montpellier, France.
Department of Orthopedic Surgery and Traumatology, Larchet 2 Hospital, Nice, France.
J Shoulder Elbow Surg. 2017 Jul;26(7):1128-1136. doi: 10.1016/j.jse.2017.01.027. Epub 2017 Mar 31.
Posterior humeral subluxation is the main cause of failure of total shoulder arthroplasty. We aimed to compare humeral head subluxation in various reference planes and to search for a correlation with retroversion, inclination, and glenoid wear.
We included 109 computed tomography scans of primary glenohumeral osteoarthritis and 97 of shoulder problems unrelated to shoulder osteoarthritis (controls); all computed tomography scans were reconstructed in the anatomic scapular plane and the glenoid hull plane that we defined. In both planes, we measured retroversion, inclination, glenohumeral offset (Walch index), and scapulohumeral offset.
Retroversion in the scapular plane (Friedman method) was lower than that in the glenoid hull plane for controls and for arthritic shoulders. The threshold of scapulohumeral subluxation was 60% and 65% in the scapular plane and glenoid hull plane, respectively. The mean upward inclination was lower in the scapular plane (Churchill method) than in the glenoid hull plane (Maurer method). In the glenoid hull plane, 35% of type A2 glenoids showed glenohumeral offset greater than 75%, with mean retroversion of 25.6° ± 6° as compared with 7.5° ± 7.2° for the "centered" type A2 glenoids (P < .0001) and an upward inclination of -1.4° ± 8° and 6.3° ± 7° (P = .03), respectively. The correlation between retroversion and scapulohumeral offset was r = 0.64 in the glenoid hull plane and r = 0.59 in the scapular plane (P < .05).
Measurement in the glenoid hull plane may be more accurate than in the scapular plane. Thus, the glenoid hull method allows for better understanding type B3 of the modified Walch classification.
肱骨头后脱位是全肩关节置换术失败的主要原因。我们旨在比较不同参考平面上的肱骨头半脱位情况，并寻找其与后倾角、倾斜度和关节盂磨损之间的相关性。
我们纳入了109例原发性盂肱关节骨关节炎的计算机断层扫描（CT）图像以及97例与肩关节骨关节炎无关的肩部问题（对照组）的CT图像；所有CT扫描图像均在我们定义的肩胛解剖平面和关节盂壳平面上进行重建。在这两个平面上，我们测量了后倾角、倾斜度、盂肱偏移（Walch指数）和肩胛肱偏移。
对照组和骨关节炎性肩部在肩胛平面上的后倾角（Friedman法）低于关节盂壳平面。肩胛肱半脱位的阈值在肩胛平面和关节盂壳平面分别为60%和65%。肩胛平面（Churchill法）的平均向上倾斜度低于关节盂壳平面（Maurer法）。在关节盂壳平面上，35%的A2型关节盂显示盂肱偏移大于75%，平均后倾角为25.6°±6°，而“居中”的A2型关节盂为7.5°±7.2°（P <.0001），向上倾斜度分别为-1.4°±8°和6.3°±7°（P = 0.03）。后倾角与肩胛肱偏移之间的相关性在关节盂壳平面上r = 0.64，在肩胛平面上r = 0.59（P <.05）。
在关节盂壳平面上进行测量可能比在肩胛平面上更准确。因此，关节盂壳测量法有助于更好地理解改良Walch分类中的B3型。
