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SLAC 和 SNAC 腕

SLAC/SNAC wrist – understanding pain from arthritis at the wrist, often after injury.

Updated Oct 2026
一幅手绘插图,描绘了一个没有面部特征的人,手腕僵硬疼痛,正费力地试图打开一个罐子。
SLAC腕关节和SNAC腕关节骨关节炎的分期。 Kieran Hirpara 4.0

本页面由机器翻译,尚未经临床医生审核。英文版本为权威版本。

您的感受

疼痛位于手腕的拇指侧,处在关节中部而不是边缘。疼痛往往在数年间逐渐加重,而不是突然出现。许多手腕疼痛的人很长时间都找不到明确的原因,因为这种关节炎在早期并不总能在普通 X 光片上显示出来。

某些动作会引发疼痛。在手向后弯曲的姿势下让手腕承重,例如用手撑着从椅子上站起来或从泳池里撑上岸,会使磨损的关节面相互挤压。同时抓握和扭转是另一个常见的诱因:转动门把手、拧干抹布或使用螺丝刀。休息通常可以缓解症状,但这种酸痛可能会让您在夜间痛醒,或在醒来时隐隐作痛,活动开之后才会松缓。

随着磨损扩散,日常活动会变得更加困难。您可能会注意到提购物袋、拿水壶倒水或打开罐子时握力变弱。向后弯曲手腕用手撑着身体,或让手腕承受全身重量,都会变得不舒服。有些人会失去手腕活动时那种顺畅利落的感觉,并开始回避任何让手在某个角度下受力的动作。

如果您的症状没有缓解、在数周内逐渐加重、在夜间把您弄醒,或使您无法工作或使用手部,请去看您的全科医生或要求专科医生评估。

实际发生了什么

您的手腕由八块小骨组成,排成两排。最靠近前臂的那一排就像前臂与手之间的缓冲垫,分散负荷,使活动更加顺畅。一条坚韧的韧带带子,也是手腕中最常受伤的韧带,把其中两块骨头连接在一起,使这一排骨头能够作为一个整体活动。

SLAC 腕始于这条韧带受损,通常是由陈旧性损伤引起的。原本由它连在一起的两块骨头会逐渐分开。其中一块,即舟骨,会改变整排骨头的活动方式,原本均匀分散的负荷现在集中到关节的一小部分上。SNAC 腕的发展过程相同,但起因是舟骨骨折后一直没有愈合,这同样会使两排骨头之间失去协调。

这种集中的负荷会磨损覆盖骨端的光滑软骨,这与膝关节可能出现的磨损性关节炎是同一种。当手腕承重时,磨损的关节面相互摩擦,这就是您用手撑着从椅子上站起来或拧螺丝刀时感到的疼痛。随着磨损从拇指侧向手腕中部扩散,握力会减弱,活动也会变得僵硬。

这种疾病按分期来描述,分期取决于磨损已经波及哪些关节面。早期,磨损仅局限于手腕的外侧边缘。后期,磨损会累及手部中央的关节。这一点很重要,因为手术方式要根据分期来选择:如果某个关键关节仍然健康,切除磨损的那一排骨头可以奏效;如果磨损已扩散得更广,则改为将剩余的部分骨头融合成一个整体。

我们可以采取的措施

Mater Private Hospital Rockhampton 的上肢外科医生 Kieran Hirpara 医生会从适合您病情的微创方案入手。患者通常由全科医生(GP)转诊至我们的诊所;如果物理治疗师建议您就诊,您仍需获得全科医生的转诊才能符合 Medicare 报销资格。我们会了解您的病史,检查您的手腕,并在必要时安排影像学检查,以确定磨损的分期。对于这样的长期问题,我们通常首先尝试非手术治疗,在其未能带来足够改善时才考虑手术。

第一步是改变手腕承重的方式。用手撑着从椅子上站起来、拧干抹布和使用螺丝刀都会使磨损的关节面相互挤压,因此调整这些动作可以减轻压力。支具可以在您工作或睡觉时固定手腕。手部治疗的目的是保持手腕活动,并增强手腕周围的力量。在考虑手术之前,我们通常会给予这些措施数周至数月的充分尝试。

止痛药物可以配合这些措施一起使用。当您比平时更多地使用手腕时,简单的抗炎药可以缓解酸痛。我们会与您讨论哪种药物适合您,以及如何与您的其他药物配合使用。

当这些措施不再能带来足够的缓解时,就会考虑手术。目的是去除引起疼痛的磨损关节面,同时尽可能保留有用的手腕活动度。如果某个关键关节仍然健康,切除磨损的那一排骨头可以让手腕通过一个新的、更顺滑的接触面活动。如果磨损已扩散得更广,将剩余的部分骨头融合成一个整体,可以让手腕稳定并能够承重。这两种都是保留活动度的选择,在活动度与力量之间如何取舍,是我们与您共同做出的决定。如果磨损范围过广,两种手术都不适用,全腕关节融合术仅保留用于特殊情况,而在适合患者的情况下,关节置换术可以作为另一种选择。

预期情况

这是一种长期存在的磨损性关节炎,因此不会很快自行缓解。如果不加处理,随着磨损从手腕外侧边缘向中部扩散,疼痛往往会在数年间逐渐加重。在此过程中,握力会减弱,活动会变得僵硬。非手术治疗可以在数周至数月内缓解酸痛,但它只是控制症状,而不能阻止磨损。

接受治疗后,预后取决于磨损扩散的程度以及哪种手术适合您的分期。如果某个关键关节仍然健康,切除磨损的那一排骨头可以带来持久的效果。如果将部分骨头融合成一个整体,大多数手腕会牢固愈合,能够承重而不再有摩擦痛。术后手部治疗很早就会开始,有时在第一周内,以减轻僵硬,而在骨头愈合期间,手腕需要固定约两个月。此后改善仍会持续:有些人在治疗后超过 3 年仍在继续恢复手腕功能。

坦白地说,并非每个手腕都能完全恢复。融合术后有些骨头没有愈合,这可能需要再次手术。用于固定融合部位的金属内固定物也可能引起手腕背侧疼痛,偶尔需要取出。少数接受了保留活动度手术的人,如果疼痛持续,日后仍需要进行全腕关节融合术。此外,在有些手腕中,即使骨头已经愈合良好,疼痛仍会持续存在。

任何手腕手术后出现的警示征象都需要迅速处理。如果您的手指、手部或手臂变得发热、发红、肿胀和疼痛,尤其是伴有发烧,请当天前往急诊科;无需全科医生转诊。如果您的手指或手部变得苍白、冰冷、发白或发青,或者突然失去感觉或活动能力,也同样如此。

如果您的症状没有缓解、在数周内逐渐加重、在夜间把您弄醒,或使您无法工作或使用手部,请去看您的全科医生或要求专科医生评估。

何时就医

这种疾病发展缓慢,因此大多数警示征象关乎变化,而不是突发的危险。如果通过休息和调整手腕承重方式后,您的手腕疼痛仍未缓解,或在数周内逐渐加重,请去看您的全科医生。如果疼痛让您在夜间醒来、使您无法工作,或者您的握力不断减弱、日常活动越来越困难,请要求专科医生评估。

任何手腕手术后,有些征象需要当天就医。如果您的手指、手部或手臂变得发热、发红、肿胀和疼痛,尤其是伴有发烧,请前往急诊科。如果您的手指或手部变得苍白、冰冷、发白或发青,或者突然失去感觉或活动能力,也同样如此。如果您在非工作时间或周末无法联系到诊所,请前往离您最近的急诊科。

关节炎本身并没有需要急诊处理的征象。需要就诊的原因在于磨损会随着时间推移而扩散,而能保留最多活动度的手术方案,在磨损累及手腕中部之前效果最好。

深入探讨

Advanced reading: the deeper science (optional)

本节内容超出了您自身治疗决策所需的范围。SLAC腕和SNAC腕值得额外阅读,因为这两种标准挽救性手术之间的选择确实是一种权衡:一种提供更大的活动度,另一种提供更大的力量,而最新的汇总证据已开始总体上倾向于其中一种。

两种手术,两种不同的妥协

一旦腕骨塌陷形成关节炎模式,关节面便无法恢复,因此两种手术都是切除关节炎接触面,而非修复它。近排腕骨切除术切除整个近排腕骨,使头状骨头部落入由舟骨和月骨腾出的关节窝中。四角融合术切除舟骨,并将剩余的四个腕骨融合为一个整体。

在直接比较240例患者时,这种妥协是明确的。四角融合术在对侧百分比的桡偏和握力方面显著更大,而近排腕骨切除术则产生了更好的屈曲、伸展和总屈伸活动范围,以及更低的总体并发症率 [1]。

这与每种手术的构建方式相对应。将四个腕骨融合成一个整体保留了驱动握力的附着结构,但消除了它们之间的运动。切除一排腕骨缩短了腕骨并创造了一个新的、活动度更大的关节,代价是失去了来自被切除结构的强度。

更大的汇总分析支持腕骨切除术

近期且规模大得多的证据已改变了权衡。在 3,174 例 SLAC 和 SNAC 腕关节患者中,近排腕骨切除术的结果优于四角融合术,且并发症发生率更低 [2]。

该比较中,并发症差异是更可靠的部分,并且有机械学解释:四角融合术必须在四个骨面上实现骨性愈合,而骨不连、内固定问题以及取出内固定的需求,是腕骨切除术根本不会出现的并发症。

审查融合术的变体本身也无法挽救这一差异。比较两角融合术与四角融合术,尽管较小的融合范围在理论上具有优势,但两种技术显示出相似的结果和并发症,因此两者均保持合理性 [3]。

决策仍可能相反的情况

汇总结果并不意味着近排腕骨切除术(carpectomy)普遍正确。这取决于头状骨(capitate)的头部及桡骨(radius)相应的关节面未受损,因为这两个关节面将构成新的关节。若骨关节炎已累及头状骨,即同一病理过程的更晚期阶段,近排腕骨切除术将缺乏健康的关节面与之形成关节,此时融合术(fusion)成为选择。

年龄和需求同样重要。对于较年轻、腕部负荷较大的患者,可能更倾向于融合术所保留的强度,并接受其较高的并发症发生率。

当两者均告失败时

若挽救性手术失败,或关节炎范围过广而两种方法均不适用,则剩余选择为腕关节全融合术和腕关节全置换术。两者在缓解疼痛和改善握力方面均有效,其并发症发生率分别为17%和19%,具有可比性;置换术后观察到功能改善,但关于置换术的长期稳健数据仍缺乏 [4]。

了解这种等效性至关重要,因为融合术和置换术通常被呈现为截然不同的方案。两者的区别在于术后遗留的状态:一个是坚固、无痛但不可动的腕关节,另一个是可活动的腕关节,但您很可能比置换假体活得更久,这意味着日后还需再次手术;而非在于手术失败的频率。

参考文献

[1] Saltzman BM, Frank JM, Slikker W, Fernandez JJ, Cohen MS, Wysocki RW. 创伤后腕关节骨关节炎行近排腕骨切除术与四角融合术的临床结局:系统综述. J Hand Surg Eur Vol. 2014;40(5):450-7. https://doi.org/10.1177/1753193414554359

[2] Hones KM, Hao KA, Rakauskas TR, Densley S, Hampton H, Kim J, et al. 舟月骨进行性塌陷(SLAC)和舟骨骨不连进行性塌陷(SNAC)腕关节行四角融合术与近排腕骨切除术:系统综述与荟萃分析. J Hand Surg Am. 2024;49(7):633-8. https://doi.org/10.1016/j.jhsa.2024.01.011

[3] Hundepool CA, Duraku LS, Quanjel TJ, van Minnen LP, Jansen MC, Zuidam JM. 中腕骨关节炎行二角、三角或四角关节融合术:系统综述与荟萃分析. J Hand Surg Am. 2025;50(1):93.e1-93.e11. https://doi.org/10.1016/j.jhsa.2023.04.018

[4] Zhu XM, Perera E, Gohal C, Dennis B, Khan M, Alolabi B. 腕关节炎患者行腕关节融合术与腕关节置换术结局的系统综述. J Hand Surg Eur Vol. 2020;46(3):297-303. https://doi.org/10.1177/1753193420953683


Evidence & references

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Overview

Pathophysiology and Anatomy

  • Scapholunate interosseous ligament injury and extrinsic ligament complex attenuation lead to palmar flexion of the scaphoid and extension of the lunate (DISI) [20].
  • The radioscaphoid joint becomes incongruous, leading to alteration in normal radioscaphoid contact forces and development of arthrosis [20].
  • As the scaphoid flexes and the scapholunate diastasis increases, the capitate migrates proximally [20].
  • Altered intercarpal contact forces result in arthrosis at the capitolunate joint [20].
  • The styloscaphoid, radioscaphoid, and capitolunate joints are affected by SLAC wrist arthritic changes [20].
  • The radiolunate joint is typically spared in SLAC wrist because of its spheroid shape [20].
  • In SNAC wrist, the distal scaphoid articular surface with the radial styloid is affected first in stage I [20].
  • In SNAC wrist, the proximal scaphoid pole and radioscaphoid fossa may be preserved in stage I [20].
  • Bone density was greater at the capitolunate joint, the radial styloid, and the radiolunate joint in SNAC wrists compared to controls [10].

Clinical Presentation

  • Symptoms of SLAC wrist include reduced grip and pinch strength [20].
  • Symptoms of SLAC wrist include stiffness with extension and radial deviation [20].
  • Symptoms of SLAC wrist include localized tenderness at the radioscaphoid articulation [20].
  • Symptoms of SLAC wrist include decreased wrist motion on extension and radial deviation [20].
  • A positive Watson shift test results when the scaphoid subluxates dorsally out of the scaphoid fossa and relocates when pressure is released [20].
  • Patients with SLAC wrist were more likely to be male and have a history of trauma compared to patients with first CMC OA [12].

Diagnosis and Staging

  • Radiographic classification of SLAC wrist has moderate reliability and reproducibility [15].
  • Radiographic classification of SNAC wrist has limited reliability [15].
  • SLAC must be distinguished from other etiologies of wrist arthritis that can mimic SLAC to appropriately inform treatment, guide prognosis, and standardize future outcome studies [6].
  • It is important to differentiate between SNAC and SLAC-Wrist for classification and preoperative planning in treatment of advanced carpal collapse [2].

Treatment Indications

  • Partial wrist fusion is indicated for painful posttraumatic and osteoarthritic conditions of the wrist that affect only part of the articulating system in a patient keen to have adequate pain control while preserving useful motion [16].
  • Common indications for partial wrist fusion include SLAC wrist, SNAC wrist, Kienböck disease, STT arthritis, and posttraumatic radiocarpal arthritis [16].
  • Chronic painful dissociative or nondissociative carpal instabilities with or without secondary arthritic change are good indications for partial wrist fusion [16].
  • In inflammatory arthritis, the disease should be in a quiescent stage to avoid ongoing clinical deterioration due to disease progression for partial wrist fusion [16].
  • Partial wrist fusion is contraindicated when there is active sepsis, panarthritis, and rapidly progressive joint destruction at a proliferative stage [16].
  • Chronic smokers have a higher incidence of nonunion with partial wrist fusion, so alternatives for pain control such as a wrist denervation can be considered [16].
  • Arthroscopic partial wrist fusions are technically demanding procedures and require extensive arthroscopic experience [16].
  • Patients with preexisting extensor tendon pathology over the wrist region may have a higher incidence of tendon complications associated with partial wrist fusion [16].
  • Arthrofibrosis and long-standing carpal collapse may pose additional difficulty and risk for partial wrist fusion [16].
  • Scaphoid excision and four-corner fusion is indicated for the treatment of the SLAC/SNAC wrist when significant pain is refractory to nonoperative measures [9].
  • Radial styloidectomy is suitable for stage I SLAC and SNAC wrist conditions [17].
  • The best indications for APSI implant are SNAC wrists stages 1 and 2 as well as SLAC wrists stage 1 [4].
  • Scaphoidectomy and capsulodesis is mostly indicated as a palliative procedure in elderly patients with posttraumatic SNAC or SLAC wrist with limited functional demands [25].
  • Arthroscopic wrist debridement and radial styloidectomy is indicated for SLAC II or SLAC III wrists as an intermediate step to relieve pain and preserve functional motion [37].

Surgical Outcomes

  • Four-corner arthrodesis with locking plate preserves satisfactory range of motion and grip strength (64% compared to the non-operated side) for SLAC and SNAC wrist [1].
  • Four-corner arthrodesis with locking plate maintains the height of the carpus and prevents the premature appearance of radiocarpal osteoarthritis for SLAC and SNAC wrist [1].
  • Both proximal row carpectomy and four corner fusion provide improvements in pain and subjective outcome measures for patients with symptomatic and appropriately staged SLAC or SNAC wrists [3].
  • Midcarpal arthrodesis is a reliable procedure for treating SLAC- and SNAC-wrists in stages II and III [7].
  • Midcarpal arthrodesis preserves some range of motion for SLAC- and SNAC-wrists [7].
  • Scaphoid excision and four-corner arthrodesis reliably diminished wrist pain in patients with stage III SLAC wrist while maintaining a 54° flexion-extension arc [11].
  • Successful scaphoid reconstruction in SNAC wrists shifts the load back onto the proximal pole and interrupts the otherwise inevitable degenerative pattern in scaphoid nonunions [13].
  • Distal scaphoid resection is a durable procedure with good long-term results for arthritis secondary to scaphoid nonunion [31].
  • 94% of patients remained satisfied after distal scaphoid resection for arthritis secondary to scaphoid nonunion [31].
  • No further wrist collapse or radiocarpal arthritis developed after distal scaphoid resection for arthritis secondary to scaphoid nonunion [31].
  • Findings favor Limited Carpal Fusion compared to Proximal Row Carpectomy for SNAC and SLAC wrist conditions, except for flexion-extension and grip strength in women [5].
  • The authors prefer proximal row carpectomy for SLAC wrists with preserved capitate head cartilage due to socio-economic benefits, lower complication rates, and procedural ease [53].
  • Capitolunate arthrodesis is a valuable alternative to four-corner fusion for selected SNAC wrist arthritis [39].
  • ARARC may be a viable surgical option for patients with SLAC wrist who desire a minimally invasive procedure [116].
  • Arthroscopic wrist debridement and radial styloidectomy may have advantages in relieving pain while preserving wrist motion for SLAC stage 2 or 3 disease [58].

Anatomy & Pathophysiology

Bony Anatomy

  • The wrist is an anatomically and functionally highly complex joint composed of eight carpal bones arranged in two rows [54].
  • The proximal carpal row contains the scaphoid, lunate, triquetrum, and pisiform [65].
  • The distal carpal row contains the trapezium, trapezoid, capitate, and hamate [65].
  • The distal radius articular surface has two concave facets, the scaphoid and lunate facets, separated by the scapholunate ridge [65].
  • The scaphoid presents a long axis inclined by 45 degrees to the long axis of the radius [71].
  • The lunate sits on the capitate and has anterior and posterior horns [71].
  • The triquetrum is not in contact with the ulna head; a fibro-cartilage disc, the triangular ligament, separates the two bones [71].
  • The carpus does not form a single rigid bony block because the eight small bones of the carpus all have different degrees of movement [71].
  • The distal row is quite rigid, but the three proximal row bones are relatively mobile [71].
  • The stability of the carpal bones does not rely upon tendon insertions, with the exception of the pisiform which is a sesamoid in flexor carpi ulnaris tendon [71].
  • Carpal stability is largely due to interosseous ligaments and bony configuration of these carpal bones [71].
  • The primary vascular supply to the scaphoid is a branch of the radial artery at the dorsal ridge [65].
  • A group of smaller vessels enters the palmar tubercle of the scaphoid and supplies the distal 30% [65].
  • The capitate head often relies on a retrograde vascular supply [65].

Ligaments

  • The scapholunate interosseous ligament is the primary stabilizer of the scapholunate joint [112].
  • The scapholunate interosseous ligament is composed of three distinct portions: proximal or membranous, dorsal, and palmar [112].
  • The dorsal portion of the scapholunate interosseous ligament is the strongest portion and prevents translation [112].
  • The palmar portion of the scapholunate interosseous ligament acts as a rotational constraint [112].
  • The scapholunate interosseous ligament is C-shaped in the sagittal plane [65].
  • The dorsal third of the scapholunate interosseous ligament is the thickest, strongest portion of the ligament [65].
  • The radioscapholunate ligament (ligament of Testut) is a volar intra-articular neurovascular structure and provides little mechanical stability [112].
  • The palmar stabilizers of the scaphoid include the radioscaphocapitate ligament, long radiolunate ligament, and short radiolunate ligament [112].
  • The dorsal stabilizers of the scaphoid are the dorsal radiocarpal ligament and the dorsal intercarpal ligament [112].
  • The triangular fibrocartilage complex (TFCC) is formed by the central meniscus homolog, the dorsal and volar radioulnar ligaments, the floor of the extensor carpi ulnaris tendon sheath, and the volar ulnocarpal ligaments [65].
  • The dorsal and volar radioulnar ligaments are the primary stabilizers of the distal radioulnar joint [65].
  • Only the peripheral 10% to 40% of the volar, ulnar, and dorsal TFCC has a vascular supply [65].

Kinematics and Biomechanics

  • The wrist can essentially be considered to be a two-joint system linking the hand to the forearm around the highly mobile bones of the proximal carpal row [66].
  • The two principle articulations are the radiocarpal and midcarpal joints, situated proximal and distal to the mobile proximal carpal row [66].
  • The proximal carpal row has no muscular or tendinous attachments and is an intercalary segment [65].
  • With ulnar deviation, the proximal row extends relative to the forearm/distal row [65].
  • With radial deviation, the proximal row flexes relative to the forearm/distal row [65].
  • With axial loading through the neutral wrist, approximately 80% of forces are transmitted through the distal radius and 20% through the distal ulna [65].
  • Of the forces transmitted through the distal radius during neutral axial loading, 60% are transmitted through the scaphoid facet and 40% through the lunate facet [65].
  • With wrist flexion, 60% of the motion is midcarpal and 40% is radiocarpal [65].
  • With wrist extension, 33% of the motion is midcarpal and 66% is radiocarpal [65].
  • The contact areas of the wrist accounted for only 20.6% of the available joint surface [105].
  • Wrist contact areas shift from a primarily palmar location to a primarily dorsal location when the wrist changes from flexion to extension [105].
  • A wrist joint should be considered biomechanically unstable when it is not able to bear loads and does not exhibit normal kinematics throughout its arc of motion [62].

SLAC Pathophysiology

  • Scapholunate advanced collapse (SLAC) wrist may result from chronic pseudogout and can appear bilaterally without a clear history of injury [14].
  • Scapholunate interosseous ligament injury and extrinsic ligament complex attenuation lead to palmar flexion of the scaphoid and extension of the lunate [20].
  • Palmar flexion of the scaphoid and extension of the lunate results in dorsal intercalated segment instability (DISI) [20].
  • The radioscaphoid joint becomes incongruous following scapholunate ligament injury, leading to alteration in the normal radioscaphoid contact forces and development of arthrosis [20].
  • The experimental kinetic behavior of the chronic SLAC wrist is similar to the one with a recent scapholunate dissociation without carpal collapse associated [18].
  • Measurements of the angular deformity between the scaphoid and the radius obtained in a cadaveric model help to explain the progression of degenerative changes in the SLAC wrist [26].

SNAC Pathophysiology

  • Scaphoid nonunion advanced collapse (SNAC) is caused by trauma [14].
  • Symptomatic scaphoid nonunion may lead to a predictable pattern of radioscaphoid and midcarpal degenerative arthritis [21].
  • Degenerative changes in scaphoid nonunion can occur early, especially when instability is present [21].
  • Instability patterns in scaphoid nonunion increase with time [21].
  • The proximal scaphoid pole and radioscaphoid fossa may be preserved in stage I SNAC wrist [20].
  • SNAC wrists differ from SLAC wrists in exhibiting a decreased sagittal lunotriquetral angle, indicating a distinct pathomechanism of carpal instability [8].
  • The chronology of the progression of SNAC and SLAC wrist is largely identical [48].
  • Only the initial stages of SNAC and SLAC wrist differ [48].

Classification

Definitions and Etiology

  • Scapholunate advanced collapse (SLAC) may result from chronic pseudogout and can appear bilaterally without a clear history of injury [14].
  • In clinical practice, SNAC pathology is observed in 60% and SLAC in 40% of cases [34].

Staging Systems

  • The severity of degenerative change in SLAC and SNAC wrists is classified into three stages [34].
  • The Watson and Ballet classification of SLAC wrist osteoarthritis is widely accepted, simple, and a well-recognized guide to treatment despite its significant limitations [51].
  • Staging systems for SNAC wrist lack agreement [27].
  • The classification of Vender et al. (1987) is widely used to describe SNAC severity, but its inter- and intra-observer reliability is poor [38].

Pathomechanics and Radiographic Features

  • Carpal malalignment in SLAC wrists affects the radio- and midcarpal joints and extends to the third carpometacarpal joint, with malalignment evident in both the sagittal and coronal planes [36].
  • The experimental kinetic behavior of the chronic SLAC wrist is similar to that of a recent scapholunate dissociation without carpal collapse [18].
  • Measurements of angular deformity between the scaphoid and the radius help explain the progression of degenerative changes in the SLAC wrist [26].
  • Carpal collapse in Kienbock’s disease is different from SLAC and does not progress to radiocarpal osteoarthritis as in post-traumatic cases [23].

Differential Diagnosis

  • It is important to differentiate between SNAC and SLAC wrist for classification and preoperative planning in the treatment of advanced carpal collapse [2].
  • The SOAC staging system differentiates SOAC from SLAC wrist and can guide treatment decisions [40].

Clinical Presentation

Symptoms and Physical Examination

  • Symptomatic SLAC wrist usually includes pain with activity, dorsal wrist swelling, and limited wrist motion [22].
  • Patients with SLAC wrist present with reduced grip and pinch strength [20].
  • Patients with SLAC wrist present with stiffness with extension and radial deviation [20].
  • Patients with SLAC wrist present with localized tenderness at the radioscaphoid articulation [20].
  • Patients with SLAC wrist present with decreased wrist motion on extension and radial deviation [20].
  • A positive Watson shift test is defined as the scaphoid subluxating dorsally out of the scaphoid fossa when pressure is directed over the palmar scaphoid tuberosity while the wrist is moved from ulnar to radial deviation, with relocation when pressure is released [20].
  • SLAC wrist may result from chronic pseudogout and can appear bilaterally without a clear history of injury [14].
  • SNAC wrist is caused by trauma [14].

Radiographic Findings and Staging

  • Plain radiographs are usually sufficient to make the diagnosis of SLAC wrist [22].
  • Joint space narrowing with sclerosis is apparent in the radioscaphoid joint in the early stages of SLAC wrist [22].
  • In stage I SNAC wrist, the distal scaphoid articular surface with the radial styloid is affected first [20].
  • In stage I SNAC wrist, the proximal scaphoid pole and radioscaphoid fossa may be preserved [20].
  • SNAC wrists differ from SLAC wrists in exhibiting a decreased sagittal lunotriquetral angle [8].
  • Carpal malalignment in SLAC wrists extends to the third carpometacarpal joint, with malalignment evident in both the sagittal and coronal planes [36].

Pathomechanics

  • The radioscaphoid joint becomes incongruous, leading to alteration in the normal radioscaphoid contact forces and development of arthrosis [20].
  • Measurements of the angular deformity between the scaphoid and the radius help to explain the progression of degenerative changes in the SLAC wrist [26].
  • Degenerative changes can occur early, especially when instability is present [21].

Investigations

Clinical Evaluation

  • A careful history and physical examination are essential in the evaluation of patients with wrist arthritis, as patients referred for surgical treatment of SLAC wrist may have pain from other conditions such as DeQuervain's tenosynovitis rather than the wrist joint itself [22].
  • Patients with SLAC wrist are more likely to be male and have a history of trauma compared to patients with first CMC OA [12].
  • SLAC wrist may result from chronic pseudogout and can appear bilaterally without a clear history of injury, whereas SNAC wrist is caused by trauma [14].
  • SLAC must be distinguished from other etiologies of wrist arthritis that can mimic it to appropriately inform treatment, guide prognosis, and standardize future outcome studies [6].
  • The Watson shift test involves directing pressure over the palmar scaphoid tuberosity while the wrist is moved from ulnar to radial deviation, with a positive test resulting when the scaphoid subluxates dorsally out of the scaphoid fossa and relocates when pressure is released [20].
  • Reduced grip and pinch strength, stiffness with extension and radial deviation, localized tenderness at the radioscaphoid articulation, and decreased wrist motion on extension and radial deviation are symptoms of SLAC wrist [20].
  • The history, staging, and treatment of SNAC wrist are similar to that for SLAC wrist [20].
  • In SNAC wrist, the distal scaphoid articular surface with the radial styloid is affected first in stage I, while the proximal scaphoid pole and radioscaphoid fossa may be preserved [20].
  • The natural inclination to study radiographs or special imaging studies prior to a thorough history and physical examination should be avoided as it introduces cognitive bias that can affect thinking and decision making [89].
  • Bilateral grip and pinch strength testing is useful to uncover underlying pathology in chronic cases, with strength potentially diminished due to muscle atrophy, pain inhibition, or learned behaviors [89].
  • A local injection of anesthetic to a painful joint or selected tendon sheath may help normalize dynamometer readings and narrow the diagnostic spectrum [89].

Radiographic Imaging

  • Tomograms may be useful in determining the extent of arthritis but rarely change the course of treatment [22].
  • Radiographic classification of SLAC wrist has moderate reliability and reproducibility, whereas classification of SNAC wrist has limited reliability [15].
  • The severity of the radiocarpal arthrosis following distal radius fracture seen on radiograph is not correlated with the presence of symptoms [20].
  • A routine radiographic series for evaluating a painful wrist consists of four views: posteroanterior, lateral, oblique, and ulnar-deviated posteroanterior scaphoid view [81].
  • Spot views of the carpal bones for detail (carpal tunnel view) are a useful radiographic technique for evaluating a painful wrist [81].
  • A series of views for instability includes anteroposterior clenched fist, posteroanterior in neutral/radial/ulnar deviation, lateral in neutral/full flexion/extension, and semipronated/semisupinated oblique views [81].
  • 10° of supination can drastically alter the developed posteroanterior radiograph of the wrist due to the significant effect of rotation on radiographic landmarks [46].
  • Radiographic scaphoid dorsal translation is correlated with MRI findings and might represent a lower cost option for early detection of the radioscaphoid joint eccentric wear seen in some stages of scapholunate instability [126].

Advanced Imaging (CT, MRI, Arthroscopy)

  • MRI should be added for evaluation of the triangular fibrocartilage, the distal radioulnar joint, and vascularity of the various carpal bones to confirm clinical suspicion and correlate with physical examination findings [81].
  • A high rate of false-positive findings on MR images of normal subjects has been reported [81].
  • A dedicated wrist coil provides enhanced resolution of wrist structures for MRI [81].
  • With proper technique, injuries to the triangular fibrocartilage complex can be demonstrated with MRI, appearing as linear defects or gaps filled with hyperintense fluid on coronal gradient-echo or T2-weighted pulse sequences [78].
  • Evaluation of the scapholunate and lunotriquetral ligaments is more challenging on MRI, but with optimal technique and equipment, the integrity of these structures can be consistently assessed [78].
  • The addition of arthrographic contrast improves the visualization of scapholunate and lunotriquetral ligaments on MR images [78].
  • MRI is useful in detecting additional marrow abnormalities in osteonecrosis, as seen in the lunate in Kienböck disease or in the scaphoid after fracture [78].
  • Asymmetry of marrow signal in proximal and distal fragments of a fractured scaphoid is suggestive of proximal pole ischemia on MRI [78].
  • Quantitative 3-D CT demonstrates that bone density was greater at the capitolunate joint, the radial styloid, and the radiolunate joint in SNAC wrists compared to controls [10].
  • Computer-aided three-dimensional analysis indicates that SNAC wrists differ from SLAC wrists in exhibiting a decreased sagittal lunotriquetral angle, indicating a distinct pathomechanism of carpal instability [8].
  • CT was of diagnostic value to view the position of the scaphoid about the radius and its changes in load in patients with scapholunate instability [47].
  • Arthroscopic assessment of intercarpal ligament injuries and instability is considered by many the “gold standard” for evaluation of these conditions [80].
  • Arthroscopy has been found to be more accurate than arthrography in identifying the location and size of triangular fibrocartilage and interosseous ligament injuries [80].
  • The inconsequent use of available modern magnetic resonance imaging (MRI) techniques and the lack of reliable preoperative diagnoses necessitated pure diagnostic arthroscopies for ulnar-sided wrist pain [118].

Pathomechanics and Differential Diagnosis

  • Scapholunate interosseous ligament injury and extrinsic ligament complex attenuation lead to palmar flexion of the scaphoid and extension of the lunate (DISI) in SLAC wrist [20].
  • The radioscaphoid joint becomes incongruous in SLAC wrist, leading to alteration in the normal radioscaphoid contact forces and development of arthrosis [20].
  • As the scaphoid flexes and the scapholunate diastasis increases in SLAC wrist, the capitate migrates proximally [20].
  • The altered intercarpal contact forces in SLAC wrist result in arthrosis at the capitolunate joint [20].
  • Carpal collapse in Kienböck disease is different from scapholunate advanced collapse (SLAC) and does not progress to radiocarpal osteoarthritis as in post-traumatic cases [23].
  • SOAC wrist is differentiated from SLAC wrist, and the SOAC staging system can guide treatment decisions [40].

Treatment

General Principles and Indications

  • Surgical treatment for SLAC wrist includes four-corner arthrodesis, capitolunate arthrodesis, complete wrist arthrodesis, proximal row carpectomy (PRC), denervation, and radial styloidectomy [14].
  • SNAC wrist has the additional surgical option of excision of the distal ununited scaphoid fragment compared to SLAC wrist [14].
  • Partial wrist fusion is indicated for painful posttraumatic and osteoarthritic conditions of the wrist that affect only part of the articulating system in a patient who is keen to have adequate pain control while preserving useful motion [16].
  • Chronic smokers have a higher incidence of nonunion after partial wrist fusion, so alternatives for pain control such as a wrist denervation can be considered [16].
  • The treatment for SLAC or SNAC wrist is identical at any given stage of the disease, with the exception that only the initial stages of SNAC and SLAC wrist differ [48].
  • Trapeziometacarpal joint arthritis and SLAC wrist may be treated either simultaneously or in stages [30].

Stage-Specific Interventions

  • For SLAC 1 wrist, partial arthrodesis of the wrist with styloidectomy of the radius is indicated [48].
  • Arthroscopic radial styloidectomy is indicated for Stage 1 SLAC and SNAC wrist as an isolated procedure or adjunct procedure together with scaphoid non-union or SL reconstruction procedures [55].
  • Midcarpal arthrodesis is a reliable procedure for treating SLAC- and SNAC-wrists in stages II and III which preserves some range of motion [7].
  • Wrist arthrodesis is generally an appropriate option for SNAC stage IV [45].
  • Wrist arthrodesis is a final option in a situation where there is no other treatments to resolve pain [45].

Proximal Row Carpectomy (PRC)

  • PRC is best indicated for Type 2 and Type 3 SLAC or SNAC wrists in which the injury has not yet involved the entire carpus [50].
  • PRC is indicated for multiple degenerative and traumatic wrist conditions that result in persistent pain and dysfunction with activities in daily living that have been unresponsive to nonoperative measures [50].
  • Proximal row carpectomy results in better outcomes and a lower complication rate compared to four-corner fusion in the treatment of scapholunate advanced collapse and scaphoid nonunion advanced collapse wrists [125].
  • Among patients treated for SNAC and SLAC wrist conditions, findings are in favour of Limited Carpal Fusion compared to Proximal Row Carpectomy, except for flexion-extension and grip strength in women [5].

Four-Corner Arthrodesis (4CF)

  • Four-corner arthrodesis with locking plate is a valuable surgical technique for treating SLAC and SNAC wrist because it preserves satisfactory range of motion and grip strength (64% compared to the non-operated side), maintains the height of the carpus and prevents the premature appearance of radiocarpal osteoarthritis, as long as the technical challenges of this procedure are mastered [1].
  • Four-corner fusion retains 60% of wrist motion and 80% of grip strength [20].

Scaphoid-Specific Procedures

  • Bone grafting of the scaphoid in symptomatic patients may help to prevent the development of arthritis [21].
  • Distal scaphoid resection is a durable procedure with good long-term results, with 94% of patients remaining satisfied and no further wrist collapse or radiocarpal arthritis developing [31].
  • Arthroscopic distal scaphoidectomy is indicated for symptom control in selected cases of SNAC wrist, as well as in the treatment of STT joint osteoarthritis [111].
  • In SNAC wrist, distal scaphoid resection can be regarded as a “buying time” procedure in removing the primary source of mechanical symptoms in painful scaphoid nonunion [111].
  • The best indication for distal scaphoidectomy in SNAC wrist is when the cartilage degeneration, osteophyte formation, and deformity are confined mainly to the distal scaphoid articular surface on both radiocarpal and midcarpal joint surfaces, manifested by severe degenerative change at the radial styloid-scaphoid articulation [111].
  • A significant dorsal lunate tilt deformity (DISI) is considered a relative contraindication to distal scaphoid excision [111].
  • Marked arthritis at the lunocapitate joint constitutes a relative contraindication of distal scaphoidectomy [111].
  • An intact SL ligament and RSC ligament are considered a prerequisite for distal scaphoidectomy to minimize progressive midcarpal collapse and DISI [111].
  • Bicolumnar fusion for SNAC wrist without bone grafting resulted in union in all cases, with postoperative Mayo wrist scores of excellent in 16 patients and good in 6 patients [107].

Combined and Adjunctive Procedures

  • For SLAC 1 wrist with trapeziometacarpal arthritis, one option is to fuse the scaphocapitate with a styloidectomy, which allows for trapeziectomy or arthroplasty [48].
  • For SLAC 1 wrist with trapeziometacarpal arthritis, another option is to perform a STT arthrodesis with a styloidectomy, which requires performing a prosthetic arthroplasty on the trapeziometacarpal joint [48].
  • Total or subtotal scaphoidectomy is a concomitant procedure for midcarpal arthrodesis in SLAC wrist and SNAC wrist [17].
  • The APSI implant has best indications for SNAC wrists stages 1 and 2 as well as SLAC wrists stage 1 [4].

Complications

  • Partial wrist fusion is not a guarantee of pain relief [16].
  • The potential advantage of partial wrist fusion in preservation of a useful arc of motion may be offset by the risks of nonunion [16].
  • The potential advantage of partial wrist fusion in preservation of a useful arc of motion may be offset by continued pain despite successful fusion [16].
  • Chronic smokers have a higher incidence of nonunion following partial wrist fusion [16].
  • Patients with preexisting extensor tendon pathology over the wrist region may have a higher incidence of tendon complications associated with complex partial wrist fusion procedures [16].
  • Arthrofibrosis poses additional difficulty and risk for partial wrist fusion [16].
  • Long-standing carpal collapse poses additional difficulty and risk for partial wrist fusion [16].
  • Total wrist fusion does not always result in complete pain relief [34].
  • Total wrist fusion causes significant functional disability [34].
  • Proximal row carpectomy results in a reduction of wrist motion [20].
  • Proximal row carpectomy results in a reduction of grip strength [20].
  • Resection of 6 mm or 10 mm of the radial styloid is associated with radial, ulnar, and palmar carpal displacement [38].
  • Resection of 6 mm or 10 mm of the radial styloid is associated with increased radial translation [17].
  • Resection of 6 mm or 10 mm of the radial styloid is associated with ulnar and palmar carpal displacement [17].
  • Resection of 3 mm of the radial styloid was not associated with radial, ulnar, or palmar carpal displacement [38].
  • The second most common complication of scaphocapitate arthrodesis is persistent wrist pain despite radiographic evidence of bony union [41].
  • Persistent wrist pain despite radiographic evidence of bony union occurred in 4 of 30 patients (13%) undergoing scaphocapitate arthrodesis [41].
  • In SLAC wrists with significant ligamentous lesions, the placement of a proximal scaphoid implant does not resolve the problem of ligamentous destabilization [57].
  • At 43 years follow-up of a vitallium scaphoid arthroplasty, radiographs demonstrated carpal collapse [32].
  • At 43 years follow-up of a vitallium scaphoid arthroplasty, radiographs demonstrated diffuse radiocarpal arthritis [32].

Recovery

  • Four-corner arthrodesis with locking plate preserves satisfactory range of motion and grip strength at 64% compared to the non-operated side [1].
  • Four-corner arthrodesis with locking plate maintains the height of the carpus [1].
  • Four-corner arthrodesis with locking plate prevents the premature appearance of radiocarpal osteoarthritis [1].
  • Limited Carpal Fusion is favored over Proximal Row Carpectomy for SNAC and SLAC wrist conditions, except for flexion-extension and grip strength in women [5].
  • Midcarpal arthrodesis preserves some range of motion in the treatment of SLAC- and SNAC-wrists in stages II and III [7].
  • Scaphoid excision and four-corner arthrodesis maintains a 54° flexion-extension arc in patients with stage III SLAC wrist [11].
  • Functional results of four-corner fusion for SLAC and SNAC wrist are good at long-term follow-up despite radiographic changes in the radiolunate joint in 73% of patients [124].
  • Distal scaphoid resection is a durable procedure with good long-term results, with 94% of patients remaining satisfied [31].
  • No further wrist collapse or radiocarpal arthritis developed in patients treated with distal scaphoid resection for arthritis secondary to scaphoid nonunion [31].
  • Distal scaphoid resection arthroplasty produced favorable, long-term clinical results and did not result in noteworthy wrist collapse [60].
  • There has been no long term deterioration of wrist function following the use of costo-osteochondral grafts in the wrist [33].

Key Evidence

  • [L4] Four-corner arthrodesis with locking plate is a valuable surgical technique for treating SLAC and SNAC wrist because it preserves satisfactory range of motion and grip strength (64% compared to the non-operated side), maintains the height of the carpus and prevents the premature appearance of radiocarpal osteoarthritis, as long as the technical challenges of this procedure are mastered. [1] (10.1016/j.hansur.2019.10.196)
  • [L4] We find it important to differentiate between SNAC and SLAC-Wrist for classification and preoperative planning in treatment of advanced carpal collapse. [2] (10.1016/0266-7681(94)90353-0)
  • [L4] Both procedures provide improvements in pain and subjective outcome measures for patients with symptomatic and appropriately staged SLAC or SNAC wrists. [3] (10.1177/1753193408100954)
  • [L3] Les meilleures indications sont les SNAC wrists stades 1 et 2 ainsi que les SLAC wrists stades 1. [4] (10.1016/j.main.2015.10.062)
  • [L3] Among patients treated for SNAC and SLAC wrist conditions, findings are in favour of Limited Carpal Fusion compared to Proximal Row Carpectomy, except for flexion-extension and grip strength in women. [5] (10.1186/s13018-023-04177-7)
  • [L5] SLAC must be distinguished from other etiologies of wrist arthritis that can mimic SLAC to appropriately inform treatment, guide prognosis, and standardize future outcome studies. [6] (10.1016/j.jhsa.2015.06.110)
  • [L4] Our data demonstrate that midcarpal arthrodesis is a reliable procedure for treating SLAC- and SNAC-wrists in stages II and III and, furthermore, one which preserves some range of motion. [7] (10.1097/01.sap.0000194245.94684.54)
  • [L4] SNAC wrists differ from SLAC wrists in exhibiting a decreased sagittal lunotriquetral angle, indicating a distinct pathomechanism of carpal instability. [8] (10.1186/s12891-025-08652-6)
  • [L4] Scaphoid excision and four-corner fusion is indicated for the treatment of the SLAC/SNAC wrist when significant pain is refractory to nonoperative measures. [9] (10.1053/otor.2003.36321)
  • [L3] Bone density was greater at the capitolunate joint, the radial styloid, and the radiolunate joint in SNAC wrists compared to controls. [10] (10.2106/jbjs.22.01350)
  • [L4] Scaphoid excision and four-corner arthrodesis reliably diminished wrist pain in patients with stage III SLAC wrist while maintaining a 54° flexion-extension arc. [11] (10.1016/0363-5023(94)90178-3)
  • [L3] Patients with SLAC wrist were more likely to be male and have a history of trauma compared to patients with first CMC OA. [12] (10.1177/1558944718788672)
  • [L4] Successful scaphoid reconstruction in SNAC wrists shifts the load back onto the proximal pole and interrupts the otherwise inevitable degenerative pattern in scaphoid nonunions. [13] (10.1016/j.jhsa.2018.06.104)
  • [L5] [14] (10.1016/j.jhsa.2011.01.018)
  • [L4] Radiographic classification of SLAC wrist has moderate reliability and reproducibility, whereas classification of SNAC wrist has limited reliability. [15] (10.1177/1753193413484629)
  • [L5] The experimental kinetic behavior of the chronic SLAC wrist is similar to the one with a recent scapholunate dissociation without carpal collapse associated. [18] (10.1177/1558944716660555w)
  • [L4] [21] (10.1016/s0363-5023(87)80198-3)
  • [L5] [22] (10.1097/00130911-199712000-00003)
  • [L5] The author notes that carpal collapse in KD is different from scapholunate advanced collapse (SLAC) and does not progress to radiocarpal osteoarthritis as in post-traumatic cases. [23] (10.1177/17531934231205707)
  • [L4] It is mostly indicated as a palliative procedure in elderly patients with posttraumatic SNAC or SLAC wrist with limited functional demands. [25] (10.1055/s-0032-1329615)
  • [L5] Measurements of the angular deformity between the scaphoid and the radius obtained in this cadaveric model help to explain the progression of degenerative changes in the SLAC wrist. [26] (10.1016/s0363-5023(87)80066-7)
  • [Paper] Staging systems for SNAC wrist lack agreement. [27] (10.1007/s12593-012-0062-2)
  • [L4] Trapeziometacarpal joint arthritis and SLAC wrist may be treated either simultaneously or in stages. [30] (10.1016/j.jhsa.2021.05.002)
  • [L4] Distal scaphoid resection is a durable procedure with good long-term results. 94% of patients remained satisfied, and no further wrist collapse or radiocarpal arthritis developed. [31] (10.1016/s0363-5023(11)60002-6)
  • [L5] At 43 years follow-up, radiographs demonstrated carpal collapse and diffuse radiocarpal arthritis, and the patient is now considering a total wrist fusion. [32] (10.1016/0363-5023(91)90015-4)
  • [L4] There has been no long term deterioration of wrist function. [33] (10.1097/00130911-200109000-00008)
  • [L4] [34] (10.1054/jhsb.2000.0434)
  • [L3] Carpal malalignment in SLAC wrists not only affects the radio- and midcarpal joints, but also extends to the third carpometacarpal joint, with malalignment evident in both the sagittal and coronal planes. [36] (10.1016/j.jhsa.2024.09.021)
  • [L4] The procedure is indicated for SLAC II or SLAC III wrists as an intermediate step to relieve pain and preserve functional motion. [37] (10.1016/j.arthro.2012.04.108)
  • [L3] [38] (10.1177/1753193417739519)
  • [Paper] The procedure is a valuable alternative to four-corner fusion for selected SNAC wrist arthritis. [39] (10.1007/s12593-015-0182-6)
  • [L4] It also differentiates SOAC from SLAC wrist and discusses how the SOAC staging system can guide treatment decisions. [40] (10.5435/jaaos-d-25-01408)
  • [Paper] The second most common complication is persistent wrist pain despite radiographic evidence of scaphocapitate bony union, occurring in 4/30 patients (13%). [41] (10.1097/00130911-200206000-00003)
  • [L4] [45] (10.1142/s2424835518300049)
  • [Paper] Our results highlight the significant effect of rotation on radiographic landmarks at the wrist, indicating that 10° of supination can drastically alter the developed radiograph. [46] (10.1177/15589447241255705)
  • [L4] Despite these, it was of diagnostic value to view the position of the scaphoid about the radius and its changes in load. [47] (10.1016/s0363-5023(03)80339-8)
  • [L5] [48] (10.1016/j.hansur.2020.08.013)
  • [Paper] [50] (10.1097/bth.0b013e3181d44526)
  • [L5] Despite its significant limitations, the Watson and Ballet classification of SLAC wrist osteoarthritis is widely accepted, simple, and a well-recognized guide to treatment. [51] (10.1097/corr.0000000000000451)
  • [L3] The authors prefer proximal row carpectomy for SLAC wrists with preserved capitate head cartilage due to socio-economic benefits, lower complication rates, and procedural ease. [53] (10.1177/1753193408087116)
  • [L1] [54] (10.1007/s00402-026-06423-z)
  • [L4] Dans les séquelles de disjonction scapholunaire (SLAC wrist) où les lésions ligamentaires sont importantes la mise en place de l’implant ne résout pas le problème de la déstabilisation ligamentaire qui nécessite un traitement approprié supplémentaire. [57] (10.1016/s1297-3203(00)73492-5)
  • [L4] The procedure studied may have advantages in relieving pain while preserving wrist motion for SLAC stage 2 or 3 disease. [58] (10.1177/1558944717725383)
  • [L4] Distal scaphoid resection arthroplasty produced favorable, long-term clinical results and did not result in noteworthy wrist collapse. [60] (10.1016/j.jhsa.2014.05.031)
  • [L5] A wrist joint should be considered biomechanically unstable when it is not able to bear loads and does not exhibit normal kinematics throughout its arc of motion. [62] (10.1053/jhsu.1999.0866)
  • [L5] The contact areas accounted for only 20.6% of the available joint surface and shift from a primarily palmar location to a primarily dorsal location when the wrist changes from flexion to extension. [105] (10.1016/s0363-5023(87)80093-x)
  • [L4] [107] (10.1097/bth.0b013e318249d454)
  • [L4] ARARC may be a viable surgical option for patients with SLAC wrist who desire a minimally invasive procedure. [116] (10.1055/s-0034-1373839)
  • [L4] The inconsequent use of available modern magnetic resonance imaging (MRI) techniques and the lack of reliable preoperative diagnoses necessitated pure diagnostic arthroscopies for ulnar-sided wrist pain. [118] (10.1177/1558944716660555hs)
  • [L4] Functional results were good at long-term follow-up despite radiographic changes in the radiolunate joint in 73% of patients. [124] (10.1177/1558944716681949)
  • [L1] In the treatment of scapholunate advanced collapse and scaphoid nonunion advanced collapse wrists, PRC results in better outcomes and a lower complication rate compared to 4CF. [125] (10.1016/j.jhsa.2024.01.011)
  • [L4] Radiographic scaphoid dorsal translation is correlated with MRI findings and might represent a lower cost option for early detection of the radioscaphoid joint eccentric wear seen in some stages of scapholunate instability. [126] (10.1177/1558944716660555ir)

References

[1] Clinical and radiological outcomes of 40 cases of SLAC and SNAC wrist treated by four-corner arthrodesis with locking plate. Hand Surgery and Rehabilitation. 2020. DOI: 10.1016/j.hansur.2019.10.196

[2] Advanced Carpal Collapse after Longstanding Scaphoid Nonunion (SNAC-Wrist) and Longstanding Scapho-Lunate Dissociation (SLAC-Wrist)—Where are the Differences?. Journal of Hand Surgery. 1994. DOI: 10.1016/0266-7681(94)90353-0

[3] Proximal Row Carpectomy vs Four Corner Fusion for Scapholunate (Slac) or Scaphoid Nonunion Advanced Collapse (Snac) Wrists: A Systematic Review of Outcomes. Journal of Hand Surgery (European Volume). 2009. DOI: 10.1177/1753193408100954

[4] L’implant APSI – indications et résultats. Chirurgie de la Main. 2015. DOI: 10.1016/j.main.2015.10.062

[5] Limited intercarpal fusion versus proximal row carpectomy in the treatment of SLAC or SNAC wrist, results after 3.5 years. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-023-04177-7

[6] Scapholunate Advanced Collapse: Nomenclature and Differential Diagnosis. The Journal of Hand Surgery. 2015. DOI: 10.1016/j.jhsa.2015.06.110

[7] Long-Term Results of Midcarpal Arthrodesis in the Treatment of Scaphoid Nonunion Advanced Collapse (SNAC-Wrist) and Scapholunate Advanced Collapse (SLAC-Wrist). Annals of Plastic Surgery. 2006. DOI: 10.1097/01.sap.0000194245.94684.54

[8] Computer-aided three-dimensional analysis of carpal alignment in scaphoid nonunion advanced collapse wrists: A comparative study with scapholunate advanced collapse and healthy wrists. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-08652-6

[9] Scaphoid excision and four-corner fusion in the SLAC/SNAC wrist. Operative Techniques in Orthopaedics. 2003. DOI: 10.1053/otor.2003.36321

[10] Quantitative 3-D CT Demonstrates Distal Row Pronation and Translation and Radiolunate Arthritis in the SNAC Wrist. Journal of Bone and Joint Surgery. 2023. DOI: 10.2106/jbjs.22.01350

[11] Surgical treatment of scapholunate advanced collapse. The Journal of Hand Surgery. 1994. DOI: 10.1016/0363-5023(94)90178-3

[12] The Epidemiology of Scapholunate Advanced Collapse. HAND. 2018. DOI: 10.1177/1558944718788672

[13] Long-Term Results of Scaphoid Grafting in 52 SNAC Wrists: Should We Cut Down on Salvage Procedures?. The Journal of Hand Surgery. 2018. DOI: 10.1016/j.jhsa.2018.06.104

[14] Scapholunate Advanced Collapse and Scaphoid Nonunion Advanced Collapse Arthritis—Update on Evaluation and Treatment. The Journal of Hand Surgery. 2011. DOI: 10.1016/j.jhsa.2011.01.018

[15] Reproducibility of radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist. Journal of Hand Surgery (European Volume). 2013. DOI: 10.1177/1753193413484629

[16] Green S Operative Hand Surgery. AUTHOR'S PREFERRED METHOD OF TREATMENT: ARTHROSCOPIC PARTIAL WRIST FUSION > Indications and Contraindications.

[17] Green S Operative Hand Surgery. AUTHOR'S PREFERRED METHOD OF TREATMENT: ARTHROSCOPIC PARTIAL WRIST FUSION > Osteotomy.

[18] Kinetics of the Wrist in Scapholunate Advanced Collapse. HAND. 2016. DOI: 10.1177/1558944716660555w

[20] Aaos Comprehensive Orthopaedic Review 3. Arthritides of the Hand and Wrist* > IV. Posttraumatic Arthritis.

[21] Degenerative change in symptomatic scaphoid nonunion. The Journal of Hand Surgery. 1987. DOI: 10.1016/s0363-5023(87)80198-3

[22] Midcarpal Arthrodesis. Techniques in Hand & Upper Extremity Surgery. 1997. DOI: 10.1097/00130911-199712000-00003

[23] Re: Luitjens J, Goller SS, Schmitt R, Erber B, Van Scoonhoven J, Hess N. Diagnostic performance of traditional radiographic indices in detection of carpal collapse in Kienbock’s disease. J Hand Surg Eur. 2023, 48: 619–24.. Journal of Hand Surgery (European Volume). 2023. DOI: 10.1177/17531934231205707

[25] Scaphoidectomy and Capsulodesis for SNAC or SLAC Stage II. Journal of Wrist Surgery. 2012. DOI: 10.1055/s-0032-1329615

[26] The effect of rotatory subluxation of the scaphoid on radio-scaphoid contact. The Journal of Hand Surgery. 1987. DOI: 10.1016/s0363-5023(87)80066-7

[27] Scaphoid Nonunion Advanced Collapse Classifications: A Reliability Study. Journal of Hand and Microsurgery. 2012. DOI: 10.1007/s12593-012-0062-2

[30] Combined Treatment of Trapeziometacarpal Joint Arthritis and Scapholunate Advanced Collapse Wrist. The Journal of Hand Surgery. 2022. DOI: 10.1016/j.jhsa.2021.05.002

[31] Distal Scaphoid Resection for Arthritis Secondary to Scaphoid Nonunion: A Twenty-year Experience. The Journal of Hand Surgery. 2011. DOI: 10.1016/s0363-5023(11)60002-6

[32] A forty-three-year follow-up of a vitallium scaphoid arthroplasty. The Journal of Hand Surgery. 1991. DOI: 10.1016/0363-5023(91)90015-4

[33] Costo-Osteochondral Grafts in the Wrist. Techniques in Hand & Upper Extremity Surgery. 2001. DOI: 10.1097/00130911-200109000-00008

[34] Midcarpal Arthrodesis with Complete Scaphoid Excision and Interposition Bone Graft in the Treatment of Advanced Carpal Collapse (SNAC/SLAC Wrist): Operative Technique and Outcome Assessment. Journal of Hand Surgery. 2000. DOI: 10.1054/jhsb.2000.0434

[36] Comparative Computer-Aided Analysis of Three-Dimensional Carpal Alignment in Scapholunate Advanced Collapse and Healthy Wrists. The Journal of Hand Surgery. 2025. DOI: 10.1016/j.jhsa.2024.09.021

[37] Arthroscopic Wrist Debridement and Radial Styloidectomy for Late‐stage Scapholunate Advanced Collapse Wrist (SS‐49). Arthroscopy. 2012. DOI: 10.1016/j.arthro.2012.04.108

[38] Radial styloidectomy for scaphoid nonunion advanced collapse – relevance of nonunion location. Journal of Hand Surgery (European Volume). 2017. DOI: 10.1177/1753193417739519

[39] Capitolunate Arthrodesis for Treatment of Scaphoid Nonunion Advanced Collapse (SNAC) Wrist Arthritis. Journal of Hand and Microsurgery. 2015. DOI: 10.1007/s12593-015-0182-6

[40] Scaphotrapeziotrapezoid Joint Osteoarthritis: Differentiating SOAC Wrist From SLAC Wrist. Journal of the American Academy of Orthopaedic Surgeons. 2026. DOI: 10.5435/jaaos-d-25-01408

[41] Scaphocapitate Arthrodesis. Techniques in Hand and Upper Extremity Surgery. 2002. DOI: 10.1097/00130911-200206000-00003

[45] Surgical Strategy for Scaphoid Nonunion Treatment. The Journal of Hand Surgery (Asian-Pacific Volume). 2018. DOI: 10.1142/s2424835518300049

[46] The Sensitivity of the Scapholunate Interval and Bony Landmarks to Wrist Rotation on Posteroanterior Radiographs. HAND. 2024. DOI: 10.1177/15589447241255705

[47] The role of CT in diagnosis of scapho-lunate instability. The Journal of Hand Surgery. 2003. DOI: 10.1016/s0363-5023(03)80339-8

[48] Trapeziometacarpal osteoarthritis and arthritis of the wrist. Hand Surgery and Rehabilitation. 2021. DOI: 10.1016/j.hansur.2020.08.013

[50] Proximal Row Carpectomy With a Dorsal Capsule Interposition Flap. Techniques in Hand & Upper Extremity Surgery. 2010. DOI: 10.1097/bth.0b013e3181d44526

[51] Classifications in Brief: Watson and Ballet Classification of Scapholunate Advanced Collapse Wrist Arthritis. Clinical Orthopaedics & Related Research. 2018. DOI: 10.1097/corr.0000000000000451

[53] Proximal Row Carpectomy Versus Four-Corner Arthrodesis as a Treatment for SLAC (Scapholunate Advanced Collapse) Wrist. Journal of Hand Surgery (European Volume). 2008. DOI: 10.1177/1753193408087116

[54] Conservative and surgical treatment of wrist osteoarthritis: a systematic review. Archives of Orthopaedic and Trauma Surgery. 2026. DOI: 10.1007/s00402-026-06423-z

[55] Green S Operative Hand Surgery. AUTHOR'S PREFERRED METHOD OF TREATMENT: ARTHROSCOPIC PARTIAL WRIST FUSION > Arthroscopic Radial Styloidectomy.

[57] Implant adaptatif du scaphoïde proximal. Chirurgie de la Main. 2000. DOI: 10.1016/s1297-3203(00)73492-5

[58] Arthroscopic Wrist Debridement and Radial Styloidectomy for Advanced Scapholunate Advanced Collapse Wrist: Long-term Follow-up. HAND. 2017. DOI: 10.1177/1558944717725383

[60] Distal Scaphoid Resection for Degenerative Arthritis Secondary to Scaphoid Nonunion: A 20-Year Experience. The Journal of Hand Surgery. 2014. DOI: 10.1016/j.jhsa.2014.05.031

[62] Position Statement: Definition of Carpal Instability. The Journal of Hand Surgery. 1999. DOI: 10.1053/jhsu.1999.0866

[65] Aaos Comprehensive Orthopaedic Review 3. Anatomy of the Hand and Wrist > VII. The Wrist.

[66] Green S Operative Hand Surgery. WRIST BIOMECHANICS > Carpal Kinematics.

[71] Exam Of The Hand Wrist 2Ed. 1.2 SKELETON OF THE WRIST.

[78] Campbell S Operative Orthopaedics 4 Volume Set. WRIST AND ELBOW.

[80] Campbell S Operative Orthopaedics 4 Volume Set. NERVE INJURIES AT THE LEVEL OF THE HAND AND WRIST > ARTHROSCOPY OF THE WRIST.

[81] Campbell S Operative Orthopaedics 4 Volume Set. NERVE INJURIES AT THE LEVEL OF THE HAND AND WRIST > RADIOGRAPHIC TECHNIQUES.

[89] Green S Operative Hand Surgery. Diagnosis and Treatment > Assessment of the Symptomatic Wrist.

[105] Load transfer characteristics of the wrist. Part I. The normal joint. The Journal of Hand Surgery. 1987. DOI: 10.1016/s0363-5023(87)80093-x

[107] Bicolumnar Fusion for Scaphoid Nonunion Advanced Collapse Without Bone Grafting. Techniques in Hand & Upper Extremity Surgery. 2012. DOI: 10.1097/bth.0b013e318249d454

[111] Green S Operative Hand Surgery. AUTHOR'S PREFERRED METHOD OF TREATMENT: ARTHROSCOPIC PARTIAL WRIST FUSION > Arthroscopic Distal Scaphoidectomy.

[112] Aaos Comprehensive Orthopaedic Review 3. Wrist Fractures and Dislocations, Carpal Dissociation, and Distal Radius Fractures > II. Carpal Ligament Injury and Perilunate Dislocation.

[116] Arthroscopic Resection Arthroplasty of the Radial Column for SLAC Wrist. Journal of Wrist Surgery. 2014. DOI: 10.1055/s-0034-1373839

[118] Preventable Repeat Wrist Arthroscopies. HAND. 2016. DOI: 10.1177/1558944716660555hs

[124] Ten-Year Minimum Follow-Up of 4-Corner Fusion for SLAC and SNAC Wrist. HAND. 2016. DOI: 10.1177/1558944716681949

[125] Four-Corner Fusion Versus Proximal Row Carpectomy for Scapholunate Advanced Collapse and Scaphoid Nonunion Advanced Collapse Wrist: A Systematic Review and Meta-Analysis. The Journal of Hand Surgery. 2024. DOI: 10.1016/j.jhsa.2024.01.011

[126] Radiologic Assessment of Scaphoid Dorsal Translation in Patients With Scapholunate Instability. HAND. 2016. DOI: 10.1177/1558944716660555ir

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