Ulnar and carpal pain in rest and during activity is common but challenging to diagnose and treat, even for experienced surgeons. The complex interplay of the anatomy combined with the countless different pathologies can make it difficult to establish the correct diagnosis. A correct diagnosis is the basis to offer the right treatment and includes a thorough patient history and clinical examination, as stressed by Brogan et al.1 The clinical examination of wrist ligament injuries consists mainly of palpation and different laxity and provocation tests like the scaphoid shift maneuver (Watsons test), Lunotriquetral ballottement test (Shuck test), Derby wrist test, foveal sign test, and distal radioulnar joint (DRUJ) laxity test.2 Common ligamentous injuries in this area include the scapholunate ligament (SL), the lunotriquetral ligament (LT), and injuries to the triangular fibrocartilaginous complex (TFCC).2,3 Kakar et al4 have proposed the Four-Leaf Clover principle as a guiding algorithm and checklist in the management of disorders of the DRUJ. Plain x-rays and advanced imaging including computed tomography, ultrasound, and magnetic resonance imaging (MRI) can also be adjuncts in the workup of these patients. Despite recent advances in MRI, and MRI arthrography being slightly more accurate than conventional MRI in detecting TFCC lesions, the gold standard for the diagnosis of ligamentous disorders in the wrist is still arthroscopy.5–12
The technique using dry arthroscopy of the wrist is well described, but mostly using regular arthroscopic equipment and often using general anesthesia.13 An arthroscopy with regular equipment and general anesthesia has the advantage of being able to address a ligamentous injury during the same procedure if necessary. Using regular equipment and general anesthesia for all cases may result in some patients undergoing surgery, diagnosing a ligamentous injury, but where no further surgical reconstruction can be recommended. The coronavirus disease 2019 pandemic has resulted in reduced resources for surgery performed in general anesthesia in most western countries, prompting an increase of procedures performed in local anesthesia. We now use a single-use, 1.9 mm chip-on-tip system (NanoScope System; Arthrex GmbH, Munich, Germany) for diagnostic arthroscopy in wide-awake local anesthesia no tourniquet (WALANT) (Figs. 1, 2).
The procedure is performed in our operation theater in the outpatient clinic at the Department of Hand Surgery. We see 2 main advantages in using the chip-on-tip system. The first is the simplicity of the procedure where the normal arthroscopy equipment is not required. Instead, a single-use sterile set with the handpiece, sheaths, and obturator is used and connected to the portable control unit. If needed, a shaver is added. This simplifies the procedure and reduces the preparations before and after the procedure significantly. The second advantage is the size of the camera. The visualization system is a 1.9 mm diameter chip-on-tip imaging technology. To our knowledge, it represents the first needle arthroscopy system, which makes the procedure minimal invasive. This together makes it easy and economically advantageous to carry out the surgical procedure on an outpatient basis.
The simplicity of the system is also reflected in its cost-efficiency. For dry arthroscopy, we use the single-use camera that is connected to the portable control unit. According to the manufacturer, the price for the kit is 6490 SEK or 623 Euro, a substantially lower cost compared with a regular arthroscopy in general anesthesia (cost 18,527 SEK or 1778 Euro). We use this technique as a diagnostic tool in patients with wrist pain and for the planning of treatment. If a tear is verified during dry arthroscopy in WALANT with the chip-on-tip system, and the optimal treatment, for example, is a ligament reconstruction, we perform this procedure later on in general anesthesia. This allows for economizing with resources in general anesthesia, reducing the costs for diagnostics wrist arthroscopy considerably.
To our knowledge, there are no publications assessing wrist arthroscopy using the needle chip-on-tip system. The purpose of this paper is to report our initial experiences using the needle chip-on-tip system in WALANT.
The ligaments in the hand are crucial to stability and function of the hand and the wrist. The intrinsic and extrinsic ligaments stabilize the carpal bones. The role of the dorsal capsule scapholunate septum is to connect the intrinsic and the extrinsic ligament system.14,15 The TFCC is fundamental for the stability of the DRUJ. It is a complex structure formed by several anatomic components: the articular fibrocartilage structure, the meniscus and the dorsal and volar distal radioulnar ligaments, with proximal or deep and distal or superficial surfaces.16,17 There are extrinsic stabilizers, such as the tendon sheath of the extensor carpi ulnaris, the ulnotriquetral, and ulnolunar ulnocarpal ligaments.
Ligament tears can result in pain in activity and rest and instability in the DRUJ and the wrist.
Therefore, the correct diagnosis of the tears is fundamental for treatment.
The main indications for this technique is as a diagnostic tool in patients with wrist pain. This includes acute and chronic pain in the DRUJ, the ulnar wrist, TFCC and carpal disorders with pain and instability. Acute cases were defined as wrist trauma in patients with negative x-rays and persistent pain after immobilization with a cast for 3 weeks. The needle chip-on-tip system is used as a real-time diagnostic option to MRI to establish a diagnosis and plan the suitable treatment. Relative contraindications include ligament injuries where clinical and radiographic findings indicate that an open repair is likely to be needed. These patients usually undergo arthroscopy in general anesthesia.
We retrospectively reviewed our first 34 cases, all operated by 2 hand surgeons with Tang expertise levels 3 and 4.18 The study was performed according to the Helsinki declaration and approved by the Swedish Ethical Review Authority (reference number 2021-06577-01). Informed consent was waived by the Swedish Ethical Review Authority because of the retrospective design of this study, which did not involve any additional risk for patients. Thirteen patients were acute injuries; all acute patients underwent an MRI before arthroscopy. The mean time to arthroscopy for acute cases was 12 days, for the nonacute cases 29 days. The mean age for the patients was 37.0 years (range: 16 to 50 y). In total, 20 of 34 patients had a preoperative MRI (Table 1). As known from previous studies, MRI has a limited value in establishing a correct diagnosis of ligament tears in the wrist.6,7 The MRI showed 6 SL tears. During arthroscopy, we could verify 4 tears, 3 Geissler IV, 1 Geissler 3.19 Two SLs did not show any pathology during arthroscopy.
TABLE 1 -
Injury Characteristics and Correlation MRI Versus Arthroscopy Findings
|MRI false positive
|MRI false negative
LT indicates lunotriquetral ligament; MRI, magnetic resonance imaging; SL, scapholunate ligament; TFCC, triangular fibrocartilaginous complex.
The MRI also showed 2 TFCC ruptures classified as Palmer 1B, both had normal findings during arthroscopy.20 The MRI missed 3 SL tears, 1 Geissler I, and 2 Geissler IV. It also missed 11 TFCC tears, which were classified according to Atzei in 10 Atzei 1 and 1 Atzei 2 and 3 LT ligament tears classified as Geissler IV.21 Among the 13 acute patients, there were 5 with ulnar pain, 2 with unclear diffuse pain, and 6 with signs for carpal pain and instability. The MRI in the group of acute patients with ulnar pain showed 1 TFCC tear and 4 cases with normal MRI findings. Arthroscopy verified 4 Atzei 1 TFCC injuries, 2 of these underwent a ligament reconstruction during a later procedure.
In the group of acute patients with carpal pain and clinical signs of instability, the MRI showed SL tears in 5 cases. In 4 of these cases, the arthroscopy verified the tear, in the fifth, the ligament was found to be intact. One patient in the acute group had an MRI without pathology, and the arthroscopy showed a Geissler IV SL tear.
Two cases which were classified as diffuse in the same group had no pathology according to the MRI findings, the arthroscopy showed 1 SL tear Geissler 1 and 1 LT ligament tear Geissler 3. In total, 4/20 MRIs showed false-positive and 6/20 false-negative findings. The cost for a wrist MRI was 4868 SEK or 467 Euro.
The patient received injections of 20 to 30 mL of mepivacain with epinephrine with or without buffer into the various standard portal sites down to the level of the capsule with or without intra-articular infiltration.22 There was a planned 30-minute delay to ensure the full hemostatic effect of the epinephrine. The patient was placed in a standard wrist arthroscopic setup with 5 kg of traction (Wrist Traction Tower; Arthrex GmbH) (Fig. 3). A pneumatic tourniquet was applied for precautionary reasons (but was never inflated). After control of adequate analgesia, a 3 to 4 portal was established, and the scope was introduced. Midcarpal and 6R portals were established as deemed necessary by the surgeon. We used the needle chip-on-tip system sharp obturator as a needle. If necessary, we changed the ports. The needle chip-on-tip system is flexible, and if moved sideways against resistance, it will bend. The wrist was examined, and the findings evaluated. An arthroscopic synovectomy (Arthrex shaver 2.3 mm) was performed to ensure full visualization and for patient comfort as a therapeutic measure if necessary. If needed, the wrist was irrigated with saline through the portal. At the end of the procedure, some patients received an additional intra-articular injection of local anesthesia through the portal. The portal sites were dressed with sterile adhesive dressing, none required suturing. Some patients were dressed with a plaster, but the majority received a soft dressing. The average length of the procedure was 14 minutes. After a short conclusive information regarding findings and treatment plan by the surgeon, the patients were discharged without any additional monitoring. The findings during the arthroscopy guide rehabilitation. In total, 34 wrists arthroscopies were performed, 13 with symptoms of carpal pain and instability, 14 with ulnar pain and 7 with diffuse wrist symptoms. In total, 9 ligament sutures or reconstructions, 3 four-corner fusions, and 1 radiocarpal fusion were subsequently undertaken. Four patients were treated with a cast immobilizing the wrist, 5 patients with stabilizing wrist exercises for 3 to 4 months under the supervision of a hand therapist, 9 patients were treated with nonsteroidal anti-inflammatory drug, physical therapy, and a wrist orthosis and 3 patients with free mobilization of the wrist.
We use this method as a diagnostic tool in patients with wrist pain, suspected ligament tears and for the planning of treatment. As is known previously, the gold standard for the diagnosis of ligament tears in the wrist is arthroscopy.5–7 The poor correlation between MRI and arthroscopic findings in our study confirm this finding. We see 2 main advantages in the use of the needle chip-on-tip system. The simplicity of the procedure, you don´t need a full arthroscopy tower, only the portable unit and the single-use sterile set with the needle chip-on-tip system handpiece (Fig. 4).
In addition, the minimal invasive character of the procedure due to the needle size makes it possible to perform the procedure in WALANT. Dry arthroscopy of the wrist using the needle chip-on-tip system in WALANT is a real-time diagnostic tool allowing a safe and effective way to quickly establish a correct diagnosis for a wide range of wrist pathologies and plan the suitable treatment. It appears to be a cost-effective alternative to MRI with substantially better accuracy. More data is required to perform a more accurate cost analysis of the technique.
The main difference to a standard arthroscopy is the needle chip-on-tip system handpiece. The advantage of the small diameter is also to some extent a disadvantage. In contrast to a conventional arthroscope the needle chip-on-tip system is flexible, has no angulation and the smaller size makes the tip sharper.
This makes it more difficult to look up or down. Moving sideways will bend the system and the risk for cartilage damage is probably increased. It is not possible to use the same technique as for a regular arthroscopy, but the learning curve is steep. We have somewhat changed our technique. We have reduced the movements with the handpiece and instead change the portal if needed for accurate visualization. No complications related to the surgical procedure were noted in this series.
In conclusion, we find that the needle chip-on-tip arthroscopy system is a safe and cost-efficient alternative to wrist MRI with superior diagnostic ability. The procedure is minimally invasive and well suited for WALANT.
1. Brogan DM, Berger RA, Kakar S. Ulnar-sided wrist pain: a critical analysis review. JBJS Rev. 2019;7:e1.
2. Andersson JK. Clinical and Arthroscopic Assessment of Wrist Ligament Injuries and Instability Dissertation [PhD]. Gothenburg, Sweden: Gothenburg University; 2016.
3. Sammer DM, Shin AY. Wrist surgery: management of chronic scapholunate and lunotriquetral ligament injuries. Plast Reconstr Surg. 2012;130:138e–156e.
4. Kakar S, Garcia-Elias M. The “Four-Leaf Clover” treatment algorithm: a practical approach to manage disorders of the distal radioulnar joint. J Hand Surg Am. 2016;41:551–564.
5. Leake RL, Mills MK, Allen H, et al. MRI of the wrist ligaments. Top Magn Reson Imaging. 2020;29:209–220.
6. Magee T. Comparison of 3-T MRI and arthroscopy of intrinsic wrist ligament and TFCC tears. AJR Am J Roentgenol. 2009;192:80–85.
7. Andersson JK, Hansson-Olofsson E, Karlsson J, et al. Cost description of clinical examination and MRI in wrist ligament injuries. J Plast Surg Hand Surg. 2018;52:30–36.
8. Smith TO, Drew BT, Toms AP, et al. The diagnostic accuracy of x-ray arthrography for triangular fibrocartilaginous complex injury: a systematic review and meta-analysis. J Hand Surg Eur Vol. 2012;37:879–887.
9. Scheck RJ, Kubitzek C, Hierner R, et al. The scapholunate interosseous ligament in MR arthrography of the wrist: correlation with non-enhanced MRI and wrist arthroscopy. Skeletal Radiol. 1997;26:263–271.
10. Ramavath AL, Unnikrishnan PN, George HL, et al. Wrist arthroscopy in children and adolescent with chronic wrist pain: arthroscopic findings compared with MRI. J Pediatr Orthop. 2017;37:e321–e325.
11. Hobby JL, Tom BD, Bearcroft PW, et al. Magnetic resonance imaging of the wrist: diagnostic performance statistics. Clin Radiol. 2001;56:50–57.
12. Boer BC, Vestering M, van Raak SM, et al. MR arthrography is slightly more accurate than conventional MRI in detecting TFCC lesions of the wrist. Eur J Orthop Surg Traumatol. 2018;28:1549–1553.
13. Burnier M, Herzberg G, Luchetti R, et al. Dry wrist arthroscopy for ulnar-sided wrist disorders. J Hand Surg Am. 2021;46:133–141.
14. Tommasini Carrara de Sambuy M, Burgess TM, Cambon-Binder A, et al. The anatomy of the dorsal capsulo-scapholunate septum: a cadaveric study. J Wrist Surg. 2017;6:244–247.
15. Overstraeten LV, Camus EJ, Wahegaonkar A, et al. Anatomical description of the dorsal capsulo-scapholunate septum (DCSS)—arthroscopic staging of scapholunate instability after DCSS sectioning. J Wrist Surg. 2013;2:149–154.
16. Palmer AK. Triangular fibrocartilage complex lesions: a classification. J Hand Surg Am. 1989;14:594–606.
17. Nakamura T, Yabe Y, Horiuchi Y. Functional anatomy of the triangular fibrocartilage complex. J Hand Surg Br. 1996;21:581–586.
18. Tang JB, Giddins G. Why and how to report surgeons’ levels of expertise. J Hand Surg Eur Vol. 2016;41:365–366.
19. Geissler WB. Arthroscopic management of scapholunate instability. Chir Main. 2006;25(suppl 1):S187–S196.
20. Adolfsson L. Arthroscopic diagnosis of ligament lesions of the wrist. J Hand Surg Br. 1994;19:505–512.
21. Atzei A, Luchetti R. Foveal TFCC tear classification and treatment. Hand Clin. 2011;27:263–272.
22. Lalonde D. Wide Awake Hand Surgery. Stuttgart, Germany: Thieme Medical Publishers; 2015.