Scapholunate interosseous ligament (SLIL) injury is one of the common wrist injuries. This condition creates wrist pain which significantly disturbs the patient’s wrist function in daily life activities. The key biomechanical alteration after SLIL disruption is scaphoid flexion, which renders the distal pole impact on the radial styloid.1,2 With improper management of this injury could eventually progress to carpal arthrosis or scapholunate advanced collapse wrist.3,4

In chronic scapholunate dissociation (SLD) injury without arthritic change, poor quality of remaining ligament can possibly be found which means the SLIL would be unrepairable.5–7 The standard treatment procedure for this specific condition to prevent scaphoid flexion is SLIL reconstruction, with varieties of multiple tendon weaving procedures.8,9 Historically, the Brunelli technique was first utilized by which a portion of the flexor carpi radialis (FCR) tendon is used to pass through a bone tunnel in a distal scaphoid and hold on the distal radius.10 Then, Van Den Abbeele and colleagues reported a modified Brunelli technique. They switched the attachment of the FCR tendon to lunate, instead of distal radius.11 This technique reduced the postoperative wrist stiffness because there was no tendon graft crossing the radiocarpal joint. Later on, Garcia-Elias and colleagues reported another modification of the Brunelli method, called triligament tenodesis (3LT), in which the FCR tendon is passed through the same scaphoid bone tunnel, after being attached to the lunate. Here, FCR is looped through the radiotriquetral (RT) ligament and sutured into itself. This procedure creates the effect of the volar scaphotrapeziotrapezoid (STT), dorsal RT, and scapholunate ligament (SL).12 This technique became established as the current standard procedure. In addition, Ross et al13 reported a technique that uses a modification of the transosseous procedure by passing the FCR graft through the bone tunnel in scaphoid, lunate, and triquetrum, then securing the graft to triquetrum with an interference screw (scapholunotriquetral tenodesis); the dorsal capsule is also augmented to the scaphoid. Afterward, the 3LT technique was challenged by Bain et al14 who proposed a quad-ligament tenodesis by adding the reinforcement of the dorsal intercarpal ligament (DICL) effect, a secondary wrist stabilizer. The main key feature of this technique is the FCR tendon strip which is looped back from the RT ligament securely anchored to the scaphoid instead of itself, as in the technique by Garcia-Elias and colleagues. In all of the techniques mentioned, the main goal is to restore the primary stabilizer which is dorsal SLIL, and to augment it with a secondary stabilizer to secure the scaphoid in a proper position.7,15,16

In this passing decade, the understanding of the anatomy and biomechanics of SLIL encourages hand surgeons to design and report a more complex technique to restore both the dorsal limb and palmar limb of the SLIL.17–19 Most techniques depend on these steps: passing a transosseous graft through the distal scaphoid from volar to dorsal, reconstructing dorsal limb of SLIL, passing the graft back through the lunate tunnel, and then using the same graft to reconstruct the volar limb. At present, wrist arthroscopy also has a crucial role in accessing the extent of the injury and assist the procedure.5,17

Despite the era of anchor sutures, the recent procedure to correct scapholunate instability still requires a drilled bone tunnel in the scaphoid to pass the graft. In our experience, this may introduce an iatrogenic scaphoid fracture or late avascular necrosis,20,21 and increased radiation exposure from fluoroscopy. In 2018, Tawonsawatruk and Kanchanathepsak22 introduced a technique named a scaphoid safety procedure for SL ligament reconstruction in a single case report, by using double anchor sutures instead of a scaphoid bone tunnel. This simple technique can avoid the risk of scaphoid fracture from creating bone tunnel. In this study, the surgical technique, functional outcomes, and radiographic outcomes of five patients who received this procedure were presented and reviewed.

MATERIALS AND METHODS

The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Institutional Review Board of Mahidol University, Human Research Ethics Committee, Faculty of Medicine, Ramathibodi Hospital, Mahidol University. Protocol code COA. MURA2023/119, date of approval January 27, 2023. The trial has been registered in the Thai Clinical Trials Registry database, identification number is TCTR20230411004. Informed consent was obtained from all subjects involved in the study. We consecutively included 5 patients of chronic SLD who presented with clinical symptoms of wrist pain. The clinical diagnosis reveals tenderness at the SL joint with a positive Watson shift test. A radiograph demonstrated by the widening of SL interval in anteroposterior (AP) view (Fig. 1A) and Clench fist AP view (Fig. 1B), the lateral view(Fig. 1C) reviewed the abnormal carpal alignment of scapholunate angle, which could neither present nor absent of dorsal intercalated segment instability (DISI) pattern depends on the severity of the case. All of the cases are characterized in the spectrum of stage II—old dynamic injury—unrepairable due to a long time, stage III—static, instability, no DISI, easily reducible, and stage IV—DISI which is reducible.3,8,15 Patient’s characteristics, clinical presentation, and staging were summarized in Table 1. The non–bone tunnel technique of SLIL reconstruction was performed as described in the operative procedure.

FIGURE 1:

Preoperative radiograph. A, AP view. B, Clench fist AP view. C, Lateral view. AP indicate anteroposterior.

TABLE 1 - Patient Characteristic and Clinical Presentation Parameters Case 1 Case 2 Case 3 Case 4 Case 5 Average Age (y) 52 48 60 37 35 46.4 Dominant hand Right Right Right Right Right — Affected wrist Right Right Right Left Right — Clinical presentation Wrist pain, synovitis Wrist pain with grip pain Wrist motion pain Grip pain, pain on motion Wrist pain, pain on wrist motion, synovitis — Duration of symptoms (wk) 18 11 12 15 10 13.2 Staging IV III III II III —

The patients with degenerative arthritic change caused by chronic SLD affecting the radioscaphoid joint, radiolunate joint, and midcarpal joint, which are the stages of scapholunate advanced collapse wrist were excluded from the study. The salvage procedure is considered as scaphoidectomy with 4-corner fusion or proximal row carpectomy for this patient group.4,23,24 The clinical data between the preoperative and postoperative were collected, including Visual Analog Scale, wrist range of motion (ROM), stress test, percent of grip strength compared with contralateral normal side, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, and the radiographic parameters.

OPERATIVE PROCEDURE Approach

The approach was performed through a dorsal longitudinal skin incision. The extensor retinaculum was divided in a zigzag manner and preserved for later repair. The surgical plane was developed through the third (extensor pollicis longus) and fourth (extensor digitorum communis) extensor compartments. The dorsal capsulotomy was approached in a radially base V incision to preserve the dorsal radiocarpal and DICL (Fig. 2A).

FIGURE 2:

A, Dorsal V shape capsulotomy. B, The SL gap identification. SL indicate scapholunate ligament.

Intraoperative Evaluation

The carpal alignment, stability, and reducibility of the scapholunate joint were evaluated. The repairability of the disrupted SLIL is rated by the quality of the ligament remnant and stump detachment from the scaphoid or lunate (Fig. 2B).

Reduction

After a full evaluation, the scapholunate joint was accurately reduced. To assist reduction, 1.2 mm Kirchner wires (K wires) were used as a joystick. Then K wires were inserted through the scapholunate joint and scapho-capitate joint. In addition, the position of the wires is inspected through direct visualization and fluoroscopic examination. The aims of this first step are to reverse the scaphoid flexion, close the SL gap, correct the carpal alignment, and maintain the reduction. (Fig. 3)

FIGURE 3:

A, SL joint reduction by using K wires as a joystick. B, Temporary fixation with K wires to SL joint and scapho-capitate joint. SL indicate scapholunate ligament.

Reconstruction

The half-slip of FCR tendon was harvested from the volar approach, whereas distal bony insertion of FCR tendon remained. (Fig. 4A) The FCR graft was passed from volar to dorsal, through the soft tissue at the radial aspect of the scaphoid tubercle and then kept tensioning on the graft from volar to dorsal direction (Fig. 4B). After this step, the wrist joint should be set up in a slightly flex position to clearly expose the working field. The dorsal surface of the scaphoid and lunate were roughened, by denuding the cartilage with a 2 to 3 mm high-speed burr to create a raw surface groove for anchor suture and graft placement (Fig. 5A). Then, the first helix type-anchor suture (Mini-Revo Anchor, Prethreaded 2.7 mm CONMEDTM) is buried in the scaphoid and the second in the lunate (Fig. 4B). Next, FCR tendon graft was placed deep-seated in the prepared dorsal scaphoid groove and securely sutured under tension (Fig. 6A). Subsequently, the FCR graft was sutured to the lunate groove under tension between scaphoid and lunate (Fig. 6B). The remnant of FCR tail was looped through the RT ligament and sutured into itself (Fig. 7). Finally, the slip of DICL suture to the FCR graft was carefully done to augment the strength and prevent graft subluxation to the wrist joint. The surgical illustration of the operative techniques was included. (Fig. 8, Supplemental Figs. 1 to 4, Supplemental Digital Content 1, https://links.lww.com/TIO/A74, Supplemental Digital Content 2, https://links.lww.com/TIO/A75, Supplemental Digital Content 3, https://links.lww.com/TIO/A76, Supplemental Digital Content 4, https://links.lww.com/TIO/A77)

FIGURE 4:

A, Half-slip FCR graft harvest from the volar side. B, FCR graft inserted from the volar to dorsal side at the soft tissue tunnel distal-radial side of the scaphoid. FCR indicate flexor carpi radialis.

FIGURE 5:

A, A 2 mm high-speed burr is used to denude the cartilage and prepare the dorsal groove. B, 2.7 mm anchor sutures placed to the scaphoid and lunate. FCR indicate flexor carpi radialis.

FIGURE 6:

A, Pretension of the FCR graft across scaphoid and secured suture to the scaphoid. B, FCR graft sutured to lunate under tension. FCR indicate flexor carpi radialis.

FIGURE 7:

A, FCR looped through the radiotriquetral ligament and sutured into itself. B, The cut of a remaining tail. FCR indicate flexor carpi radialis.

FIGURE 8:

Stabilizing technique of SL joint with K wires. SL indicate scapholunate ligament.

Closure

The remaining capsule, extensor retinaculum, subcutaneous tissue, and skin were subsequently repaired, and the wrist was immobilized by a short arm volar slab in a neutral wrist position. A postoperative radiograph was later obtained (Fig. 9).

FIGURE 9:

Immediate postoperative radiograph. A, AP view. B, Lateral view. AP indicate anteroposterior.

Postoperative Rehabilitation

Postoperative program is described in Table 2. The slab and K wires were removed at 4 weeks after operation. ROM exercise and warm water therapy were encouraged. Sports activities and wrist usage for high-load work were allowed 12 weeks after the operation.

TABLE 2 - Postoperative Protocol Week 0–4 Phase 1,
immobilization Volar type short arm slab care of K wires
passive and active finger, elbow motion Week 4–6 Phase 2,
wrist ROM exercise Remove K wires and slab
using wrist brace splint passive and active wrist motion warm bath therapy Week 6–10 Phase 3,
wrist strengthening Strengthening of wrist flexor and extension, external load to the wrist
continuing wrist ROM exercise of the wrist brace Week 10–12 Phase 4,
return to activity Progressive return to normal activity in daily life and specific activity, progressive load to the wrist

ROM indicates range of motion.

RESULTS

The clinical and radiographic parameters were evaluated 12 weeks after the surgery. The results were summarized in Table 3 (Fig. 10). All of the 5 patients were satisfied with their operation. No pain was aggravated in their daily life activities. The average Visual Analog Scale improved from 8.4 to 1.0. The mean ROM of the wrist was 75/76 degrees in flexion/extension and 88/86 degrees in supination/pronation, which was slightly limited compared with the contralateral normal side (90/90 degrees in flexion/extension and 90/90 in supination/pronation). Watson shift test and scapholunate ballottement test were negative without pain. The mean grip strength improved to 85.4% compared with the normal contralateral hand. The mean QuickDASH score was 8.62 compared with the preoperative score of 70.92. The radiograph obtained after the operation showed the mean SL interval in the wrist with AP view and AP clenched fist view at 2.50 mm and 2.68 mm, respectively. The wrist lateral view revealed the carpal alignment by the mean SL angle of 59.2 degrees.

TABLE 3 - Clinical and Radiographic Parameters Parameters Case 1 Case 2 Case 3 Case 4 Case 5 Average VAS  Preoperative 9 8 10 7 8 8.4  Postoperative 1 2 2 0 0 1.0 ROM flexion/extension (degree)  Preoperative 80/85 50/60 80/90 75/80 60/80 69/79  Postoperative 80/80 60/40 70/90 90/85 75/85 75/76 ROM supination/pronation (degree)  Preoperative 90/90 70/80 90/90 85/90 80/80 83/86  Postoperative 90/90 85/90 90/90 85/80 90/80 88/86 Watson shift test  Preoperative + + + + + —  Postoperative − − − − − — Scapholunate ballottement test  Preoperative + + − − + —  Postoperative − − − − − — Grip strength compare to contralateral normal side (%)  Preoperative 63 48 62 70 68 62.2  Postoperative 87 90 88 78 84 85.4 QuickDASH score  Preoperative 77.3 68.2 81.8 70.5 56.8 70.92  Postoperative 9.1 11.4 4.5 13.6 4.5 8.62 Static SL interval (mm)  Preoperative 4.46 4.37 3.18 2.73 3.57 3.66  Postoperative 2.42 3.55 2.75 1.97 1.83 2.50 Dynamic SL interval (mm)  Preoperative 5.03 4.82 3.39 3.38 4.25 4.17  Postoperative 2.55 3.70 2.14 3.14 1.89 2.68 SL angle (degree)  Preoperative 91 68 55 70 49 66.6  Postoperative 81 63 54 58 40 59.2

QuickDASH indicates Quick Disabilities of the Arm, Shoulder, and Hand; ROM, range of motion; SL, scapholunate ligament; VAS, Visual Analog Scale.

FIGURE 10:

Postoperative radiograph at 12 weeks. A, AP view. B, Lateral view. AP indicate anteroposterior.

DISCUSSION

We described the non–bone technique based on the principle of 3LT reconstruction.12 The weaving of the FCR tendon graft vector was still aligned with the axis of volar STT ligament, dorsal SL ligament, and dorsal RT ligament. Double bone anchors technique was used instead of other previous bone tunnel techniques to avoid complications from scaphoid bone tunnel procedures, such as carpal bone collapse,20 and to reduce radiation exposure from fluoroscope which must be used to adjust the direction of the K wire guidance in the step of scaphoid bone tunnel preparation.

The rationale for developing the double anchor technique was due to our previous experience in bone tuneling. The volar linkage among FCR insertion, STT ligament, and radioscaphocapitate ligament are attached to the distal scaphoid. These connected structures could obliterate the entry point and cause scaphoid malposition when the FCR was pulled. The fluoroscope had to be set up precisely for the drilled direction. The difficulty in judging the distance estimated for the accurate bone tunnel position always occurred and caused accidental scaphoid fractures in some cases. To explicate the bone work technique, we chose to create a dorsal bone groove with a high-speed burr instead of drilling the bone tunnel. The advantage of this technique was that the high-speed burr was easier to control the track we needed by direct visualization. The larger diameter of the tendon graft (around 2 to 3 mm) could be firstly selected and then the size of the dorsal groove was adjusted to match the graft, by adjusting the high-speed burr diameter. Compared with the standard bone tunneling technique, graft, and drilling diameter might be more difficult to be properly matched. However, the use of high-speed burr also has disadvantages such as heat necrosis, bone debris spilling in the wrist joint, and causing iatrogenic spin tract injury from unfamiliarity handling of the instrument. A proper handling technique of the high-speed burr, reducing bone temperature by normal saline flushing, and joint irrigation must be done to reduce these effects.

Based on a study by Chopra et al,25 we used a simple method to pass the FCR graft through soft tissue entry at the distal-radial side of the scaphoid, from volar to dorsal. For the graft tensioning step, the direct visualization of graft tension could be observed to attain optimal graft tension. This graft tension could correct the sagittal plane and coronal plane by the pulling force vector to prevent scaphoid flexion and also the widening of SL gap. Nevertheless, this technique mainly reconstructed the dorsal part of the SLIL, without restoring the volar part. This might cause a widening of the gap of the SL joint in some cases as a result.

For the analysis of the outcomes of this case series, the clinical outcomes after the operation of all cases were significantly improved in terms of patient satisfaction, pain, grip strength, stress test examination, and QuickDASH score. The ROM was slightly limited in both flexion and extension. There was no significant change in the ROM in supination and pronation. The radiographic outcomes showed significant improvement in static SL interval, but there was still a widening gap in one case. From the dynamic SL interval (stress radiograph), there were some patients who had certain improvements in the average SL interval. However, 2 out of 5 cases had a widening SL gap (more than 3 mm). The average SL angle of all cases was improved with only 2 cases having the SL angle more than 60 degrees. The overall postprocedural results in this study demonstrated that the holding strength of this reconstructed bone-ligament linking system could be expected to improve pain, functional outcomes, and patient satisfaction. The radiographic outcomes which reflexed to the actual scaphoid and lunate relationships could also be anticipated for improvement. However, we still could not correct all radiographic parameters in some cases.

We found 3 main pearls and pitfalls of this surgical technique:

Scapholunate gap: Before the ligament reconstruction step, a surgeon should be assured that the bone gap was already closed by the joystick joint reduction technique and was secured by K wire fixation. Fluoroscopic assistance must be used to check the optimal carpal alignment. The pulled-out of the anchor suture: This could be protected by choosing the position of the anchor at the centers of scaphoid and lunate, predrilling to the optimal depth, and using the helix type of anchor to hold more pulled-out strength. Graft subluxation to wrist joint: This situation could be prevented by planting the graft deeply seated onto the bony groove, and the depth of the groove should be around 1 mm. Dorsal capsule slip could also be distally augmented to the graft to prevent proximal subluxation.

One limitation of this study was the sample size of the case series; we were able to recruit 5 patients who matched the criteria of unrepairable SLIL injury without joint arthrosis during the past 5 years (2018 to 2022). The larger case series should be evaluated for a more comprehensive result. Moreover, this study presented only the follow-up results in the period of 12 weeks postoperation. The long-term outcomes of the laxity of the tendon graft could occur in this type of operation. It might be presented by changing the radiographic parameters which should be evaluated in further study. Finally, the anchor suture was generally used in the arthroscopic wrist procedure. In the future, there is a possibility to develop the arthroscopic ligament reconstruction technique by using specific types of anchor sutures like the tenodesis screw and circular head high-speed burr to create a graft docking track through the arthroscopic portal.

CONCLUSION

The scaphoid safety SLIL reconstruction technique is a simple and reliable treatment method for unrepairable SLIL injury, using FCR tendon weave and anchor-ligament-anchor procedure instead of previous bone tunnel techniques. Biomechanical strength of the system demonstrated by postoperative results of scaphoid flexion was corrected, but SL gaps were still remaining in some cases. However, there was no effect on clinical outcomes and patient satisfaction.

ACKNOWLEDGMENT

The authors thank Narisara Tuntiyatorn, MD, for the illustration.

REFERENCES 1. Short WH, Werner FW, Fortino MD, et al. A dynamic biomechanical study of scapholunate ligament sectioning. J Hand Surg [Am]. 1995;20:986–999. 2. Chang N, Suh N. Anatomy and biomechanics of scapholunate ligament. In: Chapter 72. Bhatia DN, Bain GI, Poehling GG, Graves BR, eds. Arthroscopy and Endoscopy of the Elbow, Wrist and Hand: Surgical Anatomy and Techniques, 1st ed. Cham: Springer International Publishing; 2022:633–640. 3. Pappou IP, Basel J, Deal DN. Scapholunate ligament injuries: a review of current concepts. Hand. 2013;8:146–156. 4. Strauch RJ. Scapholunate advanced collapse and scaphoid nonunion advanced collapse arthritis—update on evaluation and treatment. J Hand Surg [Am]. 2011;36:729–735. 5. Geissler WB. Arthroscopic management of scapholunate instability. J Wrist Surg. 2013;2:129–135. 6. Wahed K, Deore S, Bhan K, et al. Management of chronic scapholunate ligament injury. J Clin Orthop Trauma. 2020;11:529–536. 7. Mullikin I, Srinivasan RC, Bagg M. Current techniques in scapholunate ligament reconstruction. Orthop Clin North Am. 2020;51:77–86. 8. Michelotti BF, Adkinson JM, Chung KC. Chronic scapholunate ligament injury: techniques in repair and reconstruction. Hand Clin. 2015;31:437–449. 9. Luchetti R, Atzei A, Cozzolino R, et al. Current role of open reconstruction of the scapholunate ligament. J Wrist Surg. 2013;2:116–125. 10. Brunelli GA, Brunelli GR. A new surgical technique for carpal instability with scapholunate dissociation. Surg Technol Int. 1996;5:370–374. 11. Van Den Abbeele KL, Loh YC, Stanley JK, et al. Early results of a modified Brunelli procedure for scapholunate instability. J Hand Surg [Br]. 1998;23:258–261. 12. Garcia-Elias M, Lluch AL, Stanley JK. Three-ligament tenodesis for the treatment of scapholunate dissociation: indications and surgical technique. J Hand Surg [Am]. 2006;31:125–134. 13. Ross M, Loveridge J, Cutbush K, et al. Scapholunate ligament reconstruction. J Wrist Surg. 2013;2:110–115. 14. Bain GI, Watts AC, McLean J, et al. Cable-augmented, quad ligament tenodesis scapholunate reconstruction. J Wrist Surg. 2015;4:246–251. 15. Konopka G, Chim H. Optimal management of scapholunate ligament injuries. Orthop Res Rev. 2018;10:41–54. 16. Lindsay TAJ, Myers HR, Tham S. Ligamentization and remnant integration: review and analysis of current evidence and implications for scapholunate reconstruction. J Wrist Surg. 2021;10:476–483. 17. Corella F, Del Cerro M, Ocampos M, et al. Arthroscopic scapholunate ligament reconstruction, volar and dorsal reconstruction. Hand Clin. 2017;33:687–707. 18. Henry M. Reconstruction of both volar and dorsal limbs of the scapholunate interosseous ligament. J Hand Surg [Am]. 2013;38:1625–1634. 19. Zafra M, Uceda P. Treatment of static scapholunate dissociation using a slip of the flexor carpi radialis. Eur J Orthop Surg Traumatol 2020;30:1299–1306. 20. Del Piñal F, Williams DC, Viegas R, et al. Collapse after carpal bone tunneling. An underreported complication? J Hand Surg [Am]. 2023;S0363-5023(23)00365-9. doi:10.1016/j.jhsa.2023.07.008. Epub ahead of print. 21. Hjorthaug GA, Madsen JE, Nordsletten L, et al. Tendon to bone tunnel healing—a study on the time-dependent changes in biomechanics, bone remodeling, and histology in a rat model. J Orthop Res. 2015;33:216–223. 22. Tawonsawatruk TTP, Kanchanathepsak T. Scaphoid safety scapholunate ligament reconstruction for unrepairable scapholunate ligament injury: a case report. J Med Assoc Thai. 2018:269. 23. Wall LB, Stern PJ. Proximal row carpectomy. Hand Clin. 2013;29:69–78. 24. Mamede J, Castro Adeodato S, Aquino Leal R. Four-corner arthrodesis: description of surgical technique using headless retrograde crossed screws. Hand. 2018;13:156–163. 25. Chopra R, Chopra RR, Murali SR. A modified technique to reconstruct the scapholunate ligament using a slip of flexor carpi radialis tendon. J Hand Surg Eur Vol. 2011;36:710–711.