Arthroscopic dual-bone tunnel repair for palmer type IB injuries of the triangular fibrocartilage complex

Abstract

Background

Triangular fibrocartilage complex (TFCC) injuries, especially Palmer type IB, pose surgical management challenges due to associated distal radial ulnar joint (DRUJ) instability. Traditional surgeries entail risks of complications. Arthroscopic repair presents advantages but lacks consensus on optimal techniques. To evaluate arthroscopic dual-bone tunnel repair in patients with Palmer type IB TFCC injuries of the wrist.

Methods

In this retrospective case series, grip strength ratio, joint range of motion, pain visual analogue scale (VAS), modified Mayo wrist score, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were assessed before and 12 months after surgery.

Results

The cohort consisted of 45 patients. At 12 months, the grip strength ratio improved from 0.71 ± 0.08 to 0.93 ± 0.05 (P < 0.001), and wrist joint rotation increased from 126.78 ± 13.28° to 145.76 ± 8.52° (P < 0.001). VAS (1.60 ± 0.58 vs. 6.33 ± 0.91, P < 0.001), DASH (12.96 ± 3.18 vs. 46.87 ± 6.62, P < 0.001), and modified Mayo wrist (88.11 ± 4.43 vs. 63.78 ± 7.99, P < 0.001) scores all improved after surgery. The overall complication rate was 4.44%.

Conclusion

Arthroscopic dual-bone tunnel repair appears to be an effective intervention for alleviating wrist pain, restoring stability, and enhancing joint function in patients with TFCC Palmer type IB injuries.

Background

The triangular fibrocartilage complex (TFCC) is a crucial component of the wrist ulnar joint [1]. Palmer classified TFCC injuries into traumatic (type I) and degenerative (type II), with type I further categorized into IA (central perforation), IB (ulnar attachment avulsion, with or without associated ulnar distal fractures), IC (distal avulsion), and ID (radial attachment avulsion, with or without associated radial or ulnar styloid fractures) [2]. TFCC injuries are observed in 53-96.5% of patients with distal radius fractures [3,4,5]. The estimated incidence of Palmer type IB injury among TFCC injuries is 18.2-59.4% [6, 7].

TFCC Palmer IB injuries typically present as ulnar-sided tenderness, accompanied by clicking or snapping during rotation [8]. Tear of the TFCC insertion at the ulnar attachment point can result in distal radial ulnar joint (DRUJ) instability [8]. Traditional surgeries with larger incisions pose risks of more significant surgical bleeding and pain, leading to higher complication rates [1, 9, 10]. Arthroscopic TFCC repair offers advantages such as minimal trauma, rapid recovery, and reduced stress, demonstrating favorable outcomes in TFCC injuries [1, 9, 11].

Atzei subdivided the ulnar part of the TFCC into the distal superficial ligament (dc-TFCC) and proximal deep ligament (pc-TFCC) and further classified Palmer IB injuries into five types recognized by the European Wrist Arthroscopy Society (EWAS) [12]. Type 1 injuries, characterized by good DRUJ stability, can be repaired solely through arthroscopy [12]. Conversely, types 2 and 3 injuries, associated with moderate to severe DRUJ instability, require additional fixation of the injured site during arthroscopy [12]. Some arthroscopic repair techniques have also been suggested for TFCC Atzei types 2 and 3 injuries [13]. However, these techniques remain more improvement to achieve better efficacy and lower complications, such as subcutaneous suture knotting and injury to the extensor carpi ulnaris tendon or ulnar nerve with the arthroscopic technique [11]. An arthroscopic dual-bone tunnel repair has been proposed for Palmer type IB injuries of the TFCC [14, 15]; however, limited data exist on the prognosis of TFCC repair using this method. Therefore, this study aimed to explore the prognosis of arthroscopic dual-bone tunnel repair for Palmer type IB injuries of the TFCC.

Methods

Study design and patients

This retrospective case series included 45 patients with TFCC Palmer type IB injuries [2] treated at Changzhou No. 2 People’s Hospital between June 2019 and December 2021. The inclusion criteria were as follows: (1) Magnetic resonance imaging (MRI) examination indicating a TFCC injury with high signal intensity at the ulnar fovea; (2) arthroscopic exploration revealing a tear at the ulnar fovea; (3) ineffectiveness of conservative treatment for a minimum of 3 months; and (4) initial occurrence and undergoing surgical treatment at this institution. The exclusion criteria were as follows: (1) limb-associated osseous injuries on the affected side; (2) Atzei type 4 or 5 injuries; (3) patients with ulnar impaction syndrome; and (4) incomplete data. This study was approved by the Ethics Committee of Changzhou No. 2 People’s Hospital ([2021]YLA048). This article is a retrospective study. The Committee waived the requirement to obtain distinct written informed consent from the patients.

Surgical procedure and postoperative care

The preoperative evaluation included a positive ballottement test [16], X-rays, MRI findings, and intraoperative probing to assess wrist joint injuries, specifically confirming TFCC injury at the ulnar fovea point.

All surgeries were performed by the same surgeon using the dual-bone tunnel method through the ulnar fovea for TFCC repair. Patients were positioned supine, received routine brachial plexus nerve block anesthesia, and their affected limb was placed on the operating table with the elbow flexed at 90° and the shoulder abducted at 90°, secured on a support base. Standard traction using finger traps for the index, middle, and ring fingers was applied (weight of 4–8 kg). Traction force was adjusted to satisfaction before using a 2.4-mm arthroscope (Arthrex, USA), establishing 3–4 and 6-R ports. The 3–4 port served as the observation port, while the 6-R port was the operation port. If DRUJ release was not required, we generally did not use the DRUJ portal.

During surgery, synovial hyperplasia was debrided, and the hook and trampoline tests were performed to evaluate TFCC tension (Fig. 1A and B). Once we identified the tear at the TFCC fovea insertion point, and directly performed TFCC repair without decortication to the cancellous bone using the burr. We also used an arthroscopic thermal capsular shrinkage to treat partial intercarpal interosseous ligament injuries. If there was a small perforation of the TFCC cartilage disc, we performed debridement of the torn foveal fibers through the perforation site by a mini shaver (2.9-mm, Smith & Nephew, USA). If there was a large perforation of the TFCC cartilage disc, we performed foveal decortical using the mini burr (2.9-mm, Smith & Nephew, USA) through the large perforation. A longitudinal skin incision (approximately 2 cm) was made along the ulnar side of the wrist, approximately 1.5 cm proximal to the ulnar styloid. A C-shaped targeting device (Arthrex, USA) was inserted through the 6-R portal and adjusted so that the tip of the device aligned with the volar and dorsal edge of the TFCC (Fig. 1C). Two bone tunnels were created using a 1.2 mm Kirschner wire at the exit point, approximately 1.5 cm proximal to the tip of the ulnar styloid (Fig. 1D). A #2 Ethibond suture was introduced through the tunnels using a wire passer, pulled out through the 6-R portal using a titanium-nickel wire, and then pulled back through the established bone tunnels (Fig. 1E). Finally, the tensioning suture was secured with a Pushlock(2.9 mm, Arthrex, USA) anchor to the ulna. Figure 2 shows the schematic diagram of the operation.

Fig. 1

(A) Positive Hook test. (B) Positive trampoline test. (C) Guide pin positioning. (D) 1.2-mm Kirschner wires drilling dual bone tunnels. (E) Suturing thread into the bone tunnels

Fig. 2

Schematic diagram of the operation

Postoperatively, all patients received compression dressings with elastic bandages, and the affected limb was immobilized with a long-arm cast in a neutral position. Unrestricted movement was prohibited for the first three weeks, followed by the removal of the cast and the use of removable supports for an additional three weeks to protect the wrist joint. From the third to the sixth week postoperatively, patients were guided through non-weight-bearing range-of-motion exercises. At six weeks postoperatively, supports were removed to guide patients through limited weight-bearing gripping and full range-of-motion exercises. Adjustments to weight-bearing were made at ten weeks postoperatively based on patient recovery.

Data collection and outcomes

Grip strength ratio (affected side/healthy side, the grip strength of the right hand was adjusted 15% for the right-hand-dominant patients, and no adjustments were made for the left-hand-dominant patients, all of the patients were right-handed), joint range of motion (rotation and flexion-extension), visual analogue scale (VAS) for pain [17], modified Mayo wrist score [18], and Disabilities of the Arm, Shoulder, and Hand (DASH) score [19] were collected both preoperatively and at the 12-month follow-up.

We also adopted the clinical evaluation by Nakamura [14], which included relief of pain, range of pronation/supination, and DRUJ stability. According to this DRUJ evaluating system, the final clinical results were categorized as excellent, good, fair, and poor.

Statistical analysis

Statistical analysis was conducted using SPSS 22.0 (IBM, Armonk, NY, USA). The Shapiro-Wilk test was used to assess data normality. For normally distributed continuous data (grip strength ratio, DASH score, and wrist joint rotation), the results were presented as mean ± standard deviations (SD), with paired t-tests for comparisons. For skewed distributed continuous data (VAS, modified Mayo wrist score, and wrist flexion-extension range), the results were presented as median (Q1, Q3), with paired Wilcoxon rank-sum tests for comparisons. Categorical variables were presented as n (%) and analyzed using the chi-squared test. All tests were two-tailed, with statistical significance set at P < 0.05.

Results

Basic and clinical characteristics

Eight patients were lost to follow-up, resulting in 45 patients (Table 1). The last patient completed the 12-month follow-up in December 2022. All patients were able to resume normal daily activities with no restrictions 6 months postoperatively.

Table 1 Basic and clinical characteristics

Prognosis

The preoperative grip strength ratio of the patients was 0.71 ± 0.08. At the 12-month follow-up, the grip strength ratio significantly improved to 0.93 ± 0.05 (P < 0.001, Table 2). Moreover, the wrist joint rotation at the 12-month follow-up was 145.76 ± 8.52°, which was significantly greater than the preoperative values of 126.78 ± 13.28° (P < 0.001, Table 2).

Table 2 Prognostic indicators before surgery and at the 12-month follow-up

The preoperative VAS score (1.60 ± 0.58 vs. 6.33 ± 0.91, P < 0.001), DASH score (12.96 ± 3.18 vs. 46.87 ± 6.62, P < 0.001), and modified Mayo wrist score (88.11 ± 4.43 vs. 63.78 ± 7.99, P < 0.001) of the patients showed significant improvement compared to the preoperative values (Table 2).

The final clinical results obtained were 38 excellent, four good, two fair, and one poor, according to the DRUJ evaluating system.

Postoperative complications

Among 45 patients, no severe postoperative complications were reported. One patient (2.22%) experienced redness and swelling at the incision site three days post-surgery, which resolved with local dressing changes over two weeks. Another patient (2.22%) presented with symptoms of dorsal branch injury of the ulnar nerve (DBUN) postoperatively, which gradually improved over two months with oral neurotrophic medications. The overall complication rate was 4.44% (2/45).

A typical case

A 30-year-old female patient presented with recurrent right wrist pain for three months following a fall. She was diagnosed with a TFCC injury, classified as Palmer IB and Atzei type 2. Preoperative assessments included a VAS pain score of 6, a DASH score of 48, and a modified Mayo wrist score of 55. MRI imaging revealed a tear at the TFCC fovea (Fig. 3A), X-ray indicated DRUJ interval widening (Fig. 3B), and the ballottement test yielded positive results (Fig. 3C).

Fig. 3

Imaging examination and a ballottement test of a typical case. (A) Magnetic resonance imaging (MRI) showing foveal detachment of TFCC. (B) X-ray revealing DRUJ interval widening. (C) Positive ballottement test. (D) Postoperative X-ray showing a well-matched DRUJ

Operative debridement of synovial hyperplasia and assessment of TFCC tension were performed initially in the arthroscopy. The hook and trampoline tests were positive (Fig. 1A and B). Dual-bone tunnels near the ulnar fovea were created (Fig. 1D) by a C-shaped targeting device (Fig. 1C), and the suture was passed through tunnels (Fig. 1E) and anchored to the ulna using a Pushlock anchor.

At the 12-month follow-up, the patient had a stable distal radioulnar joint (DRUJ) and achieved excellent clinical results. The VAS score decreased to 0, the DASH score decreased to 10, and the modified Mayo wrist score increased to 95. X-ray imaging also displayed a well-matched DRUJ (Fig. 3D). Postoperatively, the patient did not experience any complications.

Discussion

Both open and arthroscopic surgeries can achieve favorable therapeutic outcomes in repairing TFCC injuries [12, 16]. In particular, arthroscopic procedures minimize damage to soft tissues and enhance diagnostic accuracy through intraoperative examination [1, 11]. Various arthroscopic repair techniques for TFCC injuries have emerged, classified into those involving bone tunnels and those without. Among bone tunnel repairs, single and dual-bone tunnel repairs are commonly used in TFCC injury repair [1, 11]. Liu et al. [9] suggested that repairs involving bone tunnels achieve better outcomes compared with alternative methods. Non-bone tunnel repairs have good applicability in specific patient populations. Yu et al. [20]reported a non-bone tunnel extracorporeal transosseous repair method involving a transverse drill hole below the ulnar styloid, passing a suture needle with a thread through the joint capsule from outside the ulna into the ulnar fovea, and suturing, knotting, and fixing at the TFCC residual edge. This technique, avoiding the establishment of an intra-articular bone tunnel in the ulnar joint cavity, is deemed suitable for cases of TFCC deep ligament avulsion in individuals under 14 years old with unclosed epiphyses [20]. Park et al. [16], using a C-loop aiming device, positioned a 1.1-mm Kirschner wire accurately into the center of the torn injury, expanded it with a hollow drill to create a 4-mm diameter tunnel, and completed a double-line cruciate fixation in a single channel. They believe that larger bone tunnels are more conducive to achieving a sufficiently wide and safe suture, allowing more freedom in using the suture guide needle for wide-span stitching. Atzei et al. [12]reported a technique involving arthroscopy through the DRUJ route, opening a direct central pit route (DF) about 1 cm proximal to the conventional 6U route, guiding the anchor directly into the central pit through arthroscopy, and fixing the TFCC by passing the sutures through the volar and dorsal edges after fixation. A modified arthroscopic ulnar tunnel technique for foveal TFCC showed favorable results in 44 patients [21].

The dual-bone tunnel repair technique employed in this study has advantages over previous methods. Notably, it effectively minimizes the risk of cutting the TFCC during repair due to a narrow suture span, ensuring stability and safety in repairing TFCC Palmer IB-type injuries. Furthermore, there is no need to use a hollow drill to expand the bone tunnels, reducing the risk of injury to the ulnar styloid and decreasing the likelihood of iatrogenic fractures. Additionally, drilling more tunnels in the central pit provides more bleeding surfaces, contributing to better TFCC repair [22]. The current study utilized a Pushlock anchor for suturing to the ulna, thereby avoiding skin irritation attributable to suture knotting [15]. The TFCC suture points used in the reported method are located near the ulnar side tip of the TFCC and the midpoint of the ulnar fovea of the ulna, based on data from Matsumoto et al. [23], indicating that when the suture points are in this area, there is minimal relative displacement of the stitches during forearm pronation and supination. This allows for the successful attachment of the TFCC to equidistant points in the central pit. The challenge lies in accurately locating the center of the distal ulnar head during the procedure.

The area of TFCC attachment on the ulna is approximately 34 mm², with its proximal stabilizing structures primarily composed of the deep and superficial layers of the TFCC. The deep layer attaches bluntly in the central fovea, while the superficial layer attaches sharply around the ulnar styloid process [23, 24]. Xu et al. [25] observed that the dorsal superficial and volar deep layers of the distal radioulnar ligament (DRUL) are tense during wrist pronation, while the volar superficial and dorsal deep layers are tense during supination. During wrist extension, the volar deep layer of the DRUL and the ulnocapitate ligament (UCL) become tense [26]. This suggests that excessive rotation and extension of the wrist joint may lead to ligament injuries at different locations. Moreover, when DRUJ instability is combined with TFCC injury, the pressure within the wrist joint increases significantly, particularly during extension and supination [27]. Injuries to the ulnar edge of the DRUL correspond to TFCC Palmer type IB injuries, affecting the stability of the DRUJ. For TFCC injuries with a stable DRUJ, both conservative and arthroscopic treatments can yield similar results [28]. Using a wrist brace can enhance the weight-bearing capacity of the wrist joint in traumatic TFCC injuries associated with DRUJ instability [29]. On the other hand, when the DRUJ is unstable, surgical repair is necessary. A previous study showed that there were no significant differences in wrist joint function recovery during follow-up after surgical repair within 6 months or more than 1 year after injury, indicating that even if a TFCC injury persists for over 1 year, surgical repair remains an effective treatment method [30]. This could explain the favorable outcomes observed in the present study despite several patients having injury-to-surgery intervals greater than 6 months.

The main risks associated with arthroscopic repair and reconstruction of TFCC insertion points include pain, joint stiffness, damage to the DBUN, and injury to the extensor tendons of the little finger. During postoperative long-arm cast fixation, the surgical scar on the ulnar side of the wrist joint may adhere to deeper structures, leading to pain or stiffness in the wrist joint [16]. Transient nerve dysfunction of the DBUN usually recovers spontaneously within 3–4 months, but complete nerve transection and the formation of neuromas can result in long-term effects [31]. Bayoumy et al. [32]examined the management of TFCC tears using the arthroscopic outside-in repair technique; two of their 37 patients showed complications, including one case of dorsal ulnar nerve neurapraxia and one case of weakness in the extension of the little finger. In a study by Zhao et al. [11], none of the patients had complications after the management of TFCC injuries using an outside-in transfer all-inside repair, including skin problems, DBUN injury, and injury of the extensor carpi ulnaris tendon. Gvozdenovic et al. [21] reported the use of a modified arthroscopic ulnar tunnel technique for foveal TFCC in 44 patients; five patients reported mild postoperative pain, one reported moderate pain, and two reported irritations at the ulna. In the present study, no severe postoperative complications occurred in the 45 patients. One patient displayed redness and swelling at the incision site, which resolved spontaneously. Another patient had symptoms of dorsal branch injury of the ulnar nerve, which healed over 2 months with oral neurotrophic medications. Therefore, although the sample size was too small to encounter some rarer complications, the present study suggests a low rate of complications after the dual-bone tunnel repair for TFCC Palmer type IB injuries.

This study has some limitations, including a relatively small sample size and an insufficient follow-up duration. Furthermore, the retrospective design limited the data to information available in patient records, and the exclusion of patients with incomplete datasets introduced a potential selection bias. In addition, the absence of a control group in the case series led to comparisons solely between preoperative and postoperative conditions. To mitigate these limitations, further research should explore opportunities to enhance the study by expanding the sample size, extending the follow-up duration, and incorporating more clinical factors.

Conclusion

In conclusion, arthroscopic repair using a dual-bone tunnel repair for TFCC Palmer type IB injuries showed favorable results. It may alleviate wrist joint pain, restore DRUJ stability, improve wrist joint function, and lower the incidence of postoperative complications. This approach showed the advantages of minimal trauma and rapid recovery. Its clinical value and potential for widespread application should be further explored.