1 Introduction

Carpal ligamentous injuries are frequently associated with intraarticular distal radius fractures (DRFs)¹ Among them, Scapholunate Complex (SLC) lesions are the most frequent. They can be difficult to diagnose since the preoperative clinical and imaging assessments are often insufficient.² The routine use of the arthroscopy has dramatically modified the management of ligamentous lesions concomitant to DRFs: it not only allows accurate diagnosis and staging of the lesions, but also a tailored treatment according to the stage of the instability. Nevertheless, there is no real consensus on the lesions to be systematically treated and the optimal surgical technique to be used for the treatment of associated scapholunate instability (SLI).

The purpose of this article is to discuss the arthroscopic management of acute SLC lesions concomitant to DRFs.

2 Intra-articular fractures and soft tissues injuries

Ligamentous injuries associated with DRFs involve mainly the scapholunate (SLC), the lunotriquetral (LTC) and the Triangular Fibro Cartilage (TFCC) ligamentous complexes. The SLC is injured in 30–50 % of DRFs, while lesions occur in 8,5 %–15 % of the cases for the LTC and in 50 % of the cases for TFCC (the majority of which are of degenerative origin).^3,4

The use of the arthroscopy in DRFs management has a dual purpose of controlling the articular surfaces reduction, diagnosing the associated acute ligamentous injuries,⁵ staging them precisely and performing a tailored treatment according to the grade of the instability. The admitted indications for an arthroscopic management of the DRFs are⁶: an intra-articular step and/or gap from 1 to 2 mm, the styloid fractures, the complex intra-articular multi-fragmented fractures, the Die-Punch pattern fractures (Fig. 1), the sagittal fracture lines at the height of the SL joint, a dynamic SL gap (at the fluoroscopic testing), and a widening of the distal radio-ulnar joint. Moreover, high-grade SL instabilities occur mostly after high trauma energy in young patients and can be part of an incomplete greater arch injuries (Mayfield); missed and untreated, they may lead to residual chronic wrist pain, secondary carpal instability, and eventually to scapholunate advanced collapse (SLAC).⁴

Close

Fig. 1 Die-Punch fracture in a 19-years old patient (SL = scapholunate ligament, S = scaphoid, L = lunate, R = radius) 1a: preoperative imaging 1b: Arthroscopic view. The radiocarpal assessment shows a complex lesion of the dorsal portion of the SLIOL and the DCSS 1c: Arthroscopic view. The midcarpal assessment on the right shows a SLI EWAS IIIC 1 d and e: Postoperative X-rays and satisfactory outcome after plating and ADCLR.

Export to PPT

3 Anatomy and updated evidence-based biomechanics of the SL complex lesions

The SL interosseous ligament (SLIOL) was traditionally considered as the main and primary stabilizer of the proximal carpal row with a dorsal portion playing a biomechanical key-role, while the volar bio-elastic one assures only a secondary stabilizing effect, and the intermediate part is considered as a non-vascularized fibrocartilage⁷ (Fig. 2). Based on this pattern, the techniques for stabilizing the SL joint used to be focused on the ligament itself, with intercarpal bones pinning techniques, open direct repair, or open ligamentoplasty procedures.^8–10

Close

Fig. 2 The 3 portions of the SLIOL: in red, the thick dorsal part, in blue the non-vascularized fibrocartilage and in green the volar bio-elastic ligament.

Export to PPT

However, some crucial more recent anatomical and biomechanical studies showed the SL stability is not provided by the only SLIOL but by a set of capsulo-ligamentous elements: the Scapholunate Complex^11–14 (Fig. 3). Among these elements, the prominent role of the dorsal radiocarpal anatomical structures is now admitted: the Dorsal Capsulo Scapholunate Septum (DCSS), the dorsal intercarpal ligament (DIC) and the dorsal part of the SLIOL. It was also demonstrated that the DCSS contains proprioceptive mecanoreceptors with a crucial role in dynamic SL stability¹⁵ (Fig. 4). Moreover, a high-grade instability (equivalent or greater to EWAS IIIC) can occur only if the DIC is torn. A single lesion of the SLIOL cannot lead to high grade instability (Fig. 5).

Close

Fig. 3 Scapholunate Complex 3a: the dorsal extrinsic ligaments (DIC = dorsal intercarpal ligament, DRC = dorsal radiocarpal) 3b: the volar extrinsic ligaments (LRL = long radiolunate, SRL = short radiolunate, RSC = radioscaphocapitate, SC = scaphocapitate).

Export to PPT

Close

Fig. 4 Arthroscopic view (4a) and cadaveric dissection (4b) of the DCSS.

Export to PPT

Close

Fig. 5 After sequential sectioning of the DIC, a high-grade instability occurs (on the right) Courtesy: Gustavo Gomez, Alvaro Muratore, Gabriel Glembosky (CLIMBA, Buenos Aires).

Export to PPT

Furthermore, in the acute cases of SLI (with or without DRFs), the healing potential of the intrinsic SLIOL is probably increased by the main and primary stabilizing role of the extrinsic ligaments.¹⁶ Indeed, it was observed that patients with non-treated low-grade SL instability associated to DRF showed no symptoms after 1-year of FU. They also did not develop a SLAC wrist in the long-term.^3,4

4 Arthroscopic diagnosis and staging of scapholunate instability associated with DRFS

The preoperative diagnosis is based on a body of imaging and clinical elements. The advanced imaging (MRI, arthro MRI, arthro CT-scan) and the ultrasound evaluation are part of the preoperative diagnostic arsenal.^17,18 The association of the previously cited pattern of fractures and obvious abnormalities on the arthro CT-scan or the MRI advocate strongly for the diagnosis of associated SLI. A preoperative testing under fluoroscopy and anesthesia is helpful to assess an underlying dynamic instability. Nevertheless, dynamic preoperative plan X-rays and dynamic ultrasound examination are not possible in the cases of DRFs due to the pain.

Furthermore, the imaging exams cited above are associated with a substantial false negative rate and it is admitted that the arthroscopy is the gold standard to confirm the lesions and stage them precisely by a dynamic assessment.²

The standard dorsal arthroscopic portals are generally sufficient to diagnose and treat the SLC injuries (Fig. 6). The radiocarpal assessment uses the 3–4 and 6R portals. With the scope in the 6R portal, it is possible to directly visualize a complete avulsion of the dorsal portion of the SLIOL and the DCSS (Figs. 1b and 7, video 1).

Close

Fig. 6 Standard dorsal arthroscopic portals. 6a: radiocarpal portals 6b: midcarpal portals.

Export to PPT

Close

Fig. 7 Arthroscopic radiocarpal assessment. Direct vizualisation of the torn dorsal SLIOL and DCSS.

Export to PPT

Supplementary video related to this article can be found at https://doi.org/10.1016/j.jor.2024.01.009

The following is the supplementary data related to this article.Video 1Arthroscopic radiocarpal view: Complex acute SLIOL and DCSS lesion.Video 1

The associated ligamentous lesions can also be assessed: TFCC, LTC, or, in the more severe cases an avulsion of the volar extrinsic ligaments (especially the Long Radio-lunate ligament) which are associated with an increased risk of secondary progressive radiocarpal instability (Fig. 8).

Close

Fig. 8 Volar chronic radiocarpal instability after complex articular DRF.

Export to PPT

At the midcarpal level, using the standard midcarpal ulnar (MCU) and midcarpal radial (MCR) portals, the instability is routinely staged according to GEISSLER and EWAS classifications^19,20 (Tables 1 and 2). The status of the extrinsic ligaments,²¹ especially the DIC and its insertion on the triquetrum are assessed. The arthroscopic midcarpal evaluation also enables associated lesions diagnosis: associated lunotriquetral instability, cartilaginous lesions, etc … Care must be taken not to miss an associated LT instability in the high-grade SLI (floating lunate).

It is sometimes difficult to differentiate between acute and chronic ligamentous lesions pre-existing to the fracture, especially in elderly patients. A history of chronic wrist pain or the association of cartilage degenerative change at the arthroscopic assessment can be in favor of an underlying chronic SLI. One of the possibilities to differentiate intraoperatively a chronic lesion from an acute one is the presence of a rough hematic appearance at the level of the scapholunate space, the region of the DCSS and the insertion of the extrinsic ligaments, in particular the DIC (Fig. 9, video 2).

Close

Fig. 9 Arthroscopic midcarpal assessment: rough hematic appearance at the level of the scapholunate space in favor of acute ligamentous lesions.

Export to PPT

Supplementary video related to this article can be found at https://doi.org/10.1016/j.jor.2024.01.009

The following is/are the supplementary data related to this article.Video 2Arthroscopic midcarpal assessment showing an acute EWAS IIIC instability.Video 2

5 The arthroscopic dorsal capsulo-ligamentous repair (ADCLR) in high grade SLI (EWAS IIIC- IV) associated with DRFS

An internal fixation using an anterior anatomical plate is first performed.

The arthroscopy is then carried out to control and potentially correct the articular surface reduction (Fig. 10).The ADCLR is indicated intraoperatively in the high-grade instabilities EWAS IIIC and IV.

Close

Fig. 10 Internal fixation using a volar plate under arthroscopic control.

Export to PPT

The principle of the ADCLR technique is to achieve a dorsal capsule-to-ligament suture to address the dorsal components of the SLC (DCSS, dorsal SLIOL, DIC) and stabilize the scapholunate joint (Fig. 11).

Close

Fig. 11 Main steps of the ADCLR technique 11 a: passage of the first suture 11 b: passage of the second suture 11 c: retrieving of the sutures at the midcarpal level and proximal knot 11 d: distal proximal traction on the sutures and second knot.

Export to PPT

Standard dorsal arthroscopic portals are used: radiocarpal 3–4, 6U, MCU and MCR.

After a first step of synovectomy and lavage, the status of the SLIOL and DCSS are assessed in the radiocarpal joint and the instability is staged at the midcarpal level.

The arthroscope is then placed again in the 6R portal to control the exact location of the sutures and their passage across the ligament stumps. Two absorbable monofilament sutures are passed through two intramuscular needles (usually 3.0 or 4.0, depending on the patient's size). The first needle is inserted through the 3–4 radiocarpal portal, then shifted slightly distally so to cross the dorsal capsule up to 1 mm from the capsular hole. The needle is then pushed through the radial ligament stump attached to the scaphoid, oriented obliquely from dorsal to volar, and proximal to distal with an angulation close to 45°, to reach the midcarpal joint. A second suture passed in the same way through a needle, is inserted parallel to the first one, into the ulnar ligament remnant attached to the lunate.

The principle of the next step is to fix the first knot in the midcarpal joint between the scaphoid and the lunate to reduce the SL space. The arthroscope is switched once more to the MCU portal to visualize the sutures in the midcarpal joint. A forceps is used to externalize both sutures from the MCR portal and tie the first knot outside the joint. A distal-to-proximal traction is then applied to the sutures through the 3–4 radiocarpal portal to pull the midcarpal knot and place it between the scaphoid and the lunate and volar to the dorsal portion of the SLIL. The reduction is evaluated by maintaining a proximal tension on the sutures ends after a slight release of the traction. If reduction is satisfactory, the second knot is tied in a subcutaneous position at the radiocarpal level. An opened mosquito forceps can be used to protect the extensors while tying the knots in front of MCR and 3–4 portals.

6 Discussion when and How to treat SLI associated with DRFS?

There is no real consensus whether the SLI should or not be treated according to its stage.

Geissler, in 2013, provided a treatment algorithm for acute SL injuries according to his homonym classification. For grades I injuries (stretched SLIOL), a simple immobilization is advised. In acute grades II and III, an arthroscopic reduction and a scapholunate pinning are recommended, based on the healing ability of the acute lesions with a SL gap less than 3 mm already demonstrated (Whipple). For the high-grade Geissler IV instability, the author recommends an open reduction of the SL space through a mini dorsal approach, and a stabilization using a screw.

Nevertheless, the literature suggests a less aggressive approach than the traditional Geissler algorithm.^1,3,4,22,23 For low-grades Geissler I and II instablilities, an adapted immobilization protocol after fixation is recommended by most of the authors since the non-treated patients were found asymptomatic after 1-year of FU. Moreover, there were no long-term findings for developing a SLAC wrist in these cases.

For grades III instabilities, there is no real consensus. Even if number of the authors suggest an arthroscopic reduction of the SL space associated with SL pinning, no significant difference was found at the long-term follow-up (13–15 years) after untreated grades III by Mrkonjic and Lindau. This could be explained by the role of the extrinsic stabilizers that maintain the anatomy and stability and provide a good healing potential of the acute intrinsic ligamentous lesions.

Finally, the systematic treatment of grades IV is admitted: an arthroscopic or open reduction, associated with pinning and/or anchor fixation of the SLIOL is recommended. An additional immobilization for 8–10 weeks is advised for the postoperative period.

Saab and al²³ in a systematic review of the literature that included 12 series and 467 cases, analyzed the benefit of the arthroscopy in the treatment of ligamentous injuries associated with DRFS. They found a majority of low-grade Geissler I and II scapholunate instabilities. None of these lesions were treated by the authors. The treatment algorithm was less consensual for the 24 % of the high-grade instabilities Geissler III and IV: some of them were treated, other not. When operated, the SL instability was managed by simple pinning most of the time. Open repair for grade IV was also performed.

Carratala and al²⁴ published a prospective series of 19 cases of acute injury of the SLIOL treated by arthroscopic reinsertion using a bone anchor with an additional capsulo-ligamentous repair (Fig. 12). 37 % of these lesions were associated with DRFs. The good outcome are explained by the short delay after trauma with a high potential healing of the lesions, but also by the arthroscopy technique that preserves vascularization of the tissues, the proprioceptive receptors of the DCSS (admitted role in dynamic SL stability), and do not aggress the dorsal components of the SLLC (DIC and DRC).

Close

Fig. 12 Primary repair of acute SL complex lesion using bone anchor reinsertion of SLIOL associated with ADCLR.²⁴ Courtesy: Vincente Carratala.

Export to PPT

Number of open or arthroscopic procedures have been described for the treatment of SLI. Better outcomes are observed in the acute cases and when an arthroscopic procedure is performed. A few cases are diagnosed in the early stage after trauma due to the low sensitivity of the imaging to precisely diagnose the lesions, and the frequent delay to refer the patient to the specialist. The SLI associated to the DRFs is the typical example of SLC injury that can be effectively treated thanks to the intraoperative confirmed diagnosis and staging.

The technique of ADCLR has demonstrated satisfactory results in both acute and chronic cases.^25–27 Nevertheless, it is admitted that the more recent the lesions are, the more effective this technique is. Healing potential of ligamentous SLC lesions is better during the acute phase after the trauma.¹⁶

7 Proposed treatment algorithm

Based on the updated knowledge around the dorsal extrinsic stabilizers, the good outcome of the ADCLR in the acute cases, and the admitted unnecessary treatment of the low-grade SLI associated to DRFS, we propose the following treatment algorithm:

For the acute SL instabilities grade EWAS I to EWAS IIIB, a simple immobilization after anatomical fixation of the fracture is recommended. The proper anatomical restoration of the torn ligaments is provided by a strong internal fixation (plating) in these cases. The natural soft tissues healing process is assured by the intact secondary stabilizers, especially the DIC.

In the cases of acute SL instabilities EWAS IIIC and IV, the ADCLR technique as described above is advised after anatomical internal fixation.

The wrist is immobilized in slight extension for 6 weeks after surgery, 8 weeks in case of using pinning. A adapted rehabilitation protocol is then started.

In our daily practice, we have followed this principle of treatment. We had no residual chronic instability in the cases of stages I to IIIB, which confirms our therapeutic choice. On the other hand, we strongly recommend performing an ADCLR repair in the advanced stages.

8 Conclusion

The arthroscopy is considered as a gold standard to confirm, stage, and treat the SLI.

There is no consensus whether the SL instability (SLI) associated to DRFs should or not be treated according to its grade. The superiority of the surgical treatment is not demonstrated for the low-grade scapholunate instability (Geissler I and II, EWAS II). The Geissler III (EWAS IIIA-B) instability approach remains controversial, while it is admitted that the high-grade (Geissler IV, EWAS IIIC and IV) instabilities should be treated. For the high-grade instabilities management, the ADCLR techniques are a good alternative to the open techniques repair. It is a reproducible and less invasive procedure that showed good outcome in the acute cases.