Volar Locking Plate Implant Prominence and Flexor Tendon Rupture
掌侧锁定钢板植入物突出和屈肌腱断裂

Background: Flexor tendon injury is a recognized complication of volar plate fixation of distal radial fractures. A suspected contributing factor is implant prominence at the watershed line, where the flexor tendons lie closest to the plate.
背景：屈肌腱损伤是桡骨远端骨折掌侧钢板固定的公认并发症。一个可疑的促成因素是在分水岭线处种植体突出，屈肌腱最靠近钢板。
Methods: Two parallel series of patients who underwent volar locked plating of distal radial fractures from 2005 to 2008 and with at least six months of follow-up were retrospectively reviewed. Group 1 included seventy-three distal radial fractures that were treated by three orthopaedic hand surgeons with use of a single plate design at one institution, and Group 2 included ninety-five distal radial fractures that were treated by four orthopaedic hand surgeons with use of a different plate design at another institution. On the postoperative lateral radiographs, a line was drawn tangential to the most volar extent of the volar rim, parallel to the volar cortical bone of the radial shaft. Plates that did not extend volar to this line were recorded as Grade 0. Plates volar to the line, but proximal to the volar rim, were recorded as Grade 1. Plates directly on or distal to the volar rim were recorded as Grade 2.
方法： 回顾性回顾了 2005 年至 2008 年接受掌侧锁定骨板治疗远端桡骨骨折并随访至少 6 个月的两个平行系列患者。第 1 组包括 73 例桡骨远端骨折，由三名骨科手外科医生在一个机构使用单钢板设计治疗，第 2 组包括 95 例桡骨远端骨折，由四名骨科手外科医生在另一机构使用不同的钢板设计治疗。在术后侧位 X 光片上，画一条线切向掌缘最掌侧范围，平行于桡骨干的掌侧皮质骨。没有将掌侧延伸到该线的板被记录为 0 级。板掌侧至线，但靠近掌侧边缘，被记录为 1 级。直接位于掌侧边缘或远端的板被记录为 2 级。

Results: In Group 1, the average duration of follow-up was thirteen months (range, six to forty-nine months). Three cases of flexor tendon rupture were identified among seventy-three plated radii (prevalence, 4%). Grade-2 plate prominence was found in two of the three cases with rupture and in forty-six cases (63%) overall. In Group 2, the average duration of followup was fifteen months (range, six to fifty-six months). There were no cases of flexor tendon rupture and no plates with Grade-2 prominence among ninety-five plated radii.
结果： 在第 1 组中，平均随访时间为 13 个月 （范围，6 至 49 个月）。在 73 个板半径中发现了 3 例屈肌腱断裂 （患病率，4%）。在 3 例破裂病例中有 2 例发现 2 级钢板突出，在 46 例 （63%） 总体上发现。在第 2 组中，平均随访时间为 15 个月 （范围，6 至 56 个月）。没有屈肌腱断裂的病例，在 95 个钢板半径中没有 2 级突出的钢板。

Conclusions: Flexor tendon rupture after volar plating of the distal part of the radius is an infrequent but serious complication. The plate used in Group 1 is prominent at the watershed line of the distal part of the radius, which may increase the risk of tendon injury. We found no ruptures in Group 2, perhaps as a result of the lower profile of the plate. Further studies are needed before recommending one plate over another. Regardless of plate selection, surgeons should avoid implant prominence in this area.
结论： 桡骨远端掌侧钢板后屈肌腱断裂是一种罕见但严重的并发症。第 1 组中使用的钢板在桡骨远端部分的分水岭线处突出，这可能会增加肌腱损伤的风险。我们在第 2 组中没有发现破裂，可能是由于板的轮廓较低。在推荐一个板块而不是另一个板块之前，需要进一步的研究。无论选择何种钢板，外科医生都应避免种植体在该区域突出。

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.
证据级别：治疗 III 级。有关证据级别的完整描述，请参阅作者说明。

Volar locking plate fixation of distal radial fractures has become an increasingly common technique, and recent randomized studies have supported its use ${}^{1,2}$${}^{1,2}$^(1,2){ }^{1,2}. Flexor tendon injury is a recognized complication of this technique, and the prevalence of rupture has been reported to be as high as $12{\mathrm{\%}}^3$$12{\mathrm{\%}}^3$12%^(3)12 \%^{3}. While steroid use was implicated in one small series ${}^4$${}^4$^(4){ }^{4}, a major contributing factor has been reported to be implant prominence at the watershed line ${}^{5,6}$${}^{5,6}$^(5,6){ }^{5,6} (Fig. 1), where the flexor tendons lie closest to the plate and bone. Several reports on flexor tendon rupture have involved nonlocking T-plates ${}^{7-9}$${}^{7-9}$^(7-9){ }^{7-9} and oldergeneration locking plates ${}^{3,10,11}$${}^{3,10,11}$^(3,10,11){ }^{3,10,11} as well as secondary plate prominence resulting from loss of reduction. Current-generation locking plates also have caused tendon injury, particularly with
桡骨远端骨折的掌侧锁定钢板固定已成为一种越来越普遍的技术，最近的随机研究支持其使用 ${}^{1,2}$${}^{1,2}$^(1,2){ }^{1,2} 。屈肌腱损伤是该技术的公认并发症，据报道，断裂的患病率高达 $12{\mathrm{\%}}^3$$12{\mathrm{\%}}^3$12%^(3)12 \%^{3} 。虽然类固醇的使用与一个小系列 ${}^4$${}^4$^(4){ }^{4} 有关，但据报道，一个主要的促成因素是在分水岭线 ${}^{5,6}$${}^{5,6}$^(5,6){ }^{5,6} 处种植体突出（图 1），屈肌腱最靠近板和骨。关于屈肌腱断裂的几篇报道涉及非锁定 T 型钢板 ${}^{7-9}$${}^{7-9}$^(7-9){ }^{7-9} 和老一代锁定钢板 ${}^{3,10,11}$${}^{3,10,11}$^(3,10,11){ }^{3,10,11} ，以及由于复位丧失而导致的继发性钢板突出。最新一代的锁定钢板也会导致肌腱损伤，尤其是
improper plate position ${}^{11-14}$${}^{11-14}$^(11-14){ }^{11-14}, prominent screw heads ${}^{12-14}$${}^{12-14}$^(12-14){ }^{12-14}, loss of reduction ${}^{13}$${}^{13}$^(13){ }^{13}, or inadvertent retention of drill guides ${}^{15}$${}^{15}$^(15){ }^{15}.
板位置 ${}^{11-14}$${}^{11-14}$^(11-14){ }^{11-14} 不当、螺丝头 ${}^{12-14}$${}^{12-14}$^(12-14){ }^{12-14} 突出、复位 ${}^{13}$${}^{13}$^(13){ }^{13} 损失或钻孔导轨 ${}^{15}$${}^{15}$^(15){ }^{15} 无意中保留。

Flexor tendon rupture resulting from a properly seated and well-fixed current-generation plate has not been explored. The purpose of the present study is to describe our experience with flexor tendon ruptures in two large series of distal radial fractures, with a different single plate design used in each series and with specific attention being paid to implant prominence in relation to the watershed line.
尚未探索由正确就位和固定良好的电流发生板引起的屈肌腱断裂。本研究的目的是描述我们在两个大型桡骨远端骨折系列中屈肌腱断裂的经验，每个系列使用不同的单板设计，并特别注意与分水岭线相关的种植体突出。

In Group 1, all cases of distal radial fractures that were treated with volar locked plating by three fellowship-trained or-
在第 1 组中，所有由三名受过奖学金培训或 - - 的 CV 骨锁定钢板治疗掌侧锁定骨板的远端桡骨骨折病例

Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.
披露：作者没有收到任何外部资金或赠款来支持他们的研究或准备这项工作。他们及其直系亲属均未从商业实体收到付款或其他福利，也未收到提供此类福利的承诺或协议。

Fig. 1  图 1
Anterior and lateral photographs of a distal radial model, demonstrating the watershed line (arrowheads).
远端桡骨模型的正面和侧面照片，显示了分水岭线（箭头）。
thopaedic hand surgeons at one institution with use of the AcuLoc plate (Acumed, Hillsboro, Oregon) during a four-year period ( 2005 to 2008) were identified with use of billing data and were retrospectively reviewed. In Group 2, all cases of distal radial fractures that were treated with volar locked plating by
在四年期间（2005 年至 2008 年）期间（俄勒冈州希尔斯伯勒市 Acumed）的一个机构（Acumed，Hillsboro，Oregon）的手外科医生通过使用计费数据进行了确定，并进行了回顾性审查。在第 2 组中，所有采用掌侧锁定钢板治疗的桡骨远端骨折病例
four fellowship-trained orthopaedic hand surgeons at a different institution with use of the Hand Innovations DVR plate (DePuy, Warsaw, Indiana) during the same four-year period were retrospectively reviewed. The plates are shown at their location of best fit on a radial model in Figures 2 and 3.
回顾性回顾了在同一四年期间在不同机构（DePuy，华沙，印第安纳州）使用 Hand Innovations DVR 板的四名受过奖学金培训的骨科手外科医生。在图 2 和图 3 中，板显示在径向模型上的最佳拟合位置。

Fig. 2  图 2

Fig. 3  图 3

Fig. 2 Photograph of the Acu-Loc standard left volar distal radial plate at the position of best fit on a model.
图 2 Acu-Loc 标准左掌侧桡骨远端钢板在模型上最佳拟合位置的照片。
Fig. 3 Photograph of the DVR standard left volar distal radial plate at the position of best fit on a model.
图 3 DVR 标准左掌侧桡骨远端钢板在模型上最佳拟合位置的照片。

TABLE I Characteristics of Patients and Injuries
表 I 患者和损伤特征

Patients with fewer than six months of follow-up were excluded. Fọur other patients were excluded because of early plate removal because of presumed metal allergy (one patient; Group 1), revision fixation (one patient; Group 1), distal radioulnar joint impingement (one patient; Group 1), and deep infection (one patient; Group 2). The final cohorts included seventy-three plated distal radii in seventy-two patients in Group 1 and ninety-five plated distal radii in ninety-three patients in Group 2. There was a small but significant difference between the groups with regard to average age, but there were no significant differences with regard to sex, laterality, open injury, or AO fracture type ${}^{16}$${}^{16}$^(16){ }^{16} (Table I).
排除随访少于 6 个月的患者。此外，其他患者因推测金属过敏而提前取出板而被排除在外（1 名患者;第 1 组），翻修固定 （1 例患者;第 1 组），远端桡尺关节撞击 （1 例患者;第 1 组）和深部感染 （1 例患者;第 2 组）。最终队列包括第 1 组 72 例患者的 73 个骨板远端桡骨和第 2 组 93 例患者的 95 个骨板远端桡骨。两组之间在平均年龄方面存在微小但显著的差异，但在性别、偏侧性、开放性损伤或 AO 骨折类型 ${}^{16}$${}^{16}$^(16){ }^{16} 方面没有显著差异（表 I）。

All procedures were performed with use of fluoroscopy. Plate size and position were determined on the basis of the anatomic fit of the plate, the need to secure fracture fragments, and the medial-lateral boundaries of the bone. No specific at-
所有程序均使用透视进行。钢板的尺寸和位置是根据钢板的解剖贴合性、固定骨折碎片的需要以及骨骼的内侧-外侧边界来确定的。没有具体的 at-
tempts were made to minimize volar prominence. The pronator quadratus and the intermediate fibrous zone ${}^5$${}^5$^(5){ }^{5} (the tissue between the pronator and wrist capsular attachments) were routinely repaired over the plate, although the quality and durability of the repair could not be retrospectively assessed. There were no significant differences between the groups with regard to additional procedures performed at the time of the index operation, except that distal ulnar fixation was more prevalent in Group 2 (Table II).
尝试以尽量减少掌侧突出。旋前肌方肌和中间纤维区 ${}^5$${}^5$^(5){ }^{5} （旋前肌和腕关节囊附件之间的组织）在钢板上常规修复，但无法回顾性评估修复的质量和持久性。在指数手术时进行的额外作方面，两组之间没有显著差异，除了尺骨远端固定在第 2 组中更普遍（表 II）。

All radiographs were analyzed for evidence of loss of reduction or implant prominence. The best available postoperative lateral radiograph was selected on the basis of the narrowest projected profile of the plate. This view was confirmed to be an appropriate lateral view by confirming projection of the pisiform over the distal part of the scaphoid. On this view, a “critical line” was drawn tangential to the most volar extent of
分析所有 X 线片是否有复位丧失或植入物突出的证据。根据钢板最窄的投影轮廓选择最好的术后侧位 X 线片。通过确认豌豆骨在舟状骨远端部分的投影，确认该视图是合适的侧视图。根据这种观点，在最掌侧范围的切线处画了一条“临界线”

TABLE II Additional Procedures at Index Operation
表 II 索引作的附加程序

No. of patients  不。患者
No. of plated distal radii
不。电镀远端半径
Carpal tunnel release (no. of procedures)
腕管松解术（手术次数）
Allograft bone (no. of procedures)
同种异体移植骨（手术次数）
External fixation (no. of procedures)
外固定 （手术次数）
Rad al styloid pinning (no. of procedures)
Rad al 茎突固定（程序数量）
Scapholunate ligament repair (no. of procedures)
舟月韧带修复（手术次数）
Ulnar fixation (no. of procedures)
尺骨固定术（手术次数）
Distal radioulnar joint pinning (no. of procedures)
远端桡尺关节固定（手术次数）
Scaphoid fixation (no. of procedures)
舟状骨固定术（手术次数）
Phalanx fixation (no. of procedures)
指骨固定术（手术次数）

72
73

93
95
11
0
1
4
3
12
3
3
1
0.10
0.19
0.58
0.70
1.0
0.02*
1.0
0.63
1.0
*Significant.  *重要。