Department of Orthopaedic Surgery, Hand and Upper Extremity Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, Suita, Japan.
Department of Orthopaedic Surgery, Hand and Upper Extremity Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
J Shoulder Elbow Surg. 2021 Jul;30(7):1626-1635. doi: 10.1016/j.jse.2020.09.014. Epub 2020 Oct 7.
In complex proximal humeral fractures, bone resorption of the greater tuberosity is sometimes observed after open reduction and internal fixation (ORIF). However, this has not been well characterized, and risk factors for resorption are not completely understood. We aimed (1) to identify the risk factors associated with bone resorption of the greater tuberosity and (2) to quantify the geometric and bone density characteristics associated with bone resorption using 3-dimensional computed tomography models in complex proximal humeral fractures treated with ORIF.
We identified a retrospective cohort of 136 patients who underwent ORIF of 3- or 4-part proximal humeral fractures; greater tuberosity resorption developed after ORIF in 30 of these patients. We collected demographic, fracture-related, and surgery-related characteristics and performed multivariable logistic regression analysis to identify factors independently associated with the development of greater tuberosity resorption. Furthermore, we identified 30 age- and sex-matched patients by use of propensity score matching to perform quantitative fragment-specific analysis using 3-dimensional computed tomography models. After the fragment of the greater tuberosity was identified, the number of fragments, the relative fragment volume to the humeral head, and the relative bone density to the coracoid process were calculated. Measurements were compared between matched case-control groups.
We found that an unreduced greater tuberosity (odds ratio [OR], 10.9; P < .001), inadequate medial support at the calcar (OR, 15.0; P < .001), and the use of an intramedullary fibular strut (OR, 4.5; P = .018) were independently associated with a higher risk of bone resorption. Quantitative fragment-specific analysis showed that greater tuberosities with a larger number of fragments (5 ± 2 vs. 3 ± 2, P = .021), smaller fragments (9.9% ± 3.8% vs. 18.6% ± 4.7%, P < .001), and fragments with a lower bone density (66.4% ± 14.3% vs. 88.0% ± 18.4%, P = .001) had higher rates of resorption.
An unreduced greater tuberosity or inadequate medial support increases the risk of greater tuberosity resorption, as do a larger number of fracture fragments, smaller fragments, and lower bone density. Additionally, fibular strut grafting is an independent risk factor for tuberosity resorption. Further study is needed, but alternatives to strut grafting such as femoral head allograft may warrant serious consideration.
在复杂的肱骨近端骨折中，切开复位内固定（ORIF）后有时会观察到肱骨头大结节的骨质吸收。然而，这并没有得到很好的描述，骨质吸收的危险因素也不完全清楚。我们的目的是：（1）确定与肱骨头大结节骨质吸收相关的危险因素；（2）使用 3 维 CT 模型，定量分析复杂肱骨近端骨折 ORIF 后与骨质吸收相关的几何和骨密度特征。
我们回顾性分析了 136 例接受 3 部分或 4 部分肱骨近端骨折 ORIF 的患者，其中 30 例患者在 ORIF 后出现肱骨头大结节骨质吸收。我们收集了人口统计学、骨折相关和手术相关特征，并进行了多变量逻辑回归分析，以确定与大结节骨质吸收发展相关的独立因素。此外，我们通过倾向评分匹配，选择了 30 名年龄和性别匹配的患者，使用 3 维 CT 模型进行定量分析。在确定大结节的骨折块后，计算骨折块的数量、与肱骨头的相对体积以及与喙突的相对骨密度。对匹配的病例对照组进行测量比较。
我们发现，未复位的大结节（比值比[OR]，10.9；P <.001）、内侧 calcar 支持不足（OR，15.0；P <.001）和使用髓内腓骨支撑（OR，4.5；P =.018）与骨质吸收的风险增加独立相关。定量分析显示，具有更多骨折块（5 ± 2 比 3 ± 2，P =.021）、更小的骨折块（9.9% ± 3.8%比 18.6% ± 4.7%，P <.001）和较低骨密度（66.4% ± 14.3%比 88.0% ± 18.4%，P =.001）的大结节骨质吸收发生率更高。
未复位的大结节或内侧 calcar 支持不足会增加大结节骨质吸收的风险，骨折块数量较多、骨折块较小、骨密度较低也是如此。此外，腓骨支撑移植是大结节骨质吸收的独立危险因素。需要进一步研究，但替代支撑移植的方法，如股骨头同种异体移植，可能需要认真考虑。
