Clinical Outcomes of Arthroscopic Ligament-Sparing Dorsal Capsulodesis for Partial Scapholunate Ligament Tear

Abstract

Introduction  Various wrist arthroscopy techniques can be used in the management of scapholunate ligament (SLL) partial tears but their success has not been proven. Arthroscopic techniques including thermal shrinkage are becoming more popular in the management of partial SLL injuries. We hypothesized that arthroscopic ligament-sparing capsular tightening yields reliable and satisfactory results for the management of partial SLL tears.

Methods  A prospective cohort study was conducted on adult (age ≥18 years) patients with chronic partial SLL tears. All patients failed a trial of conservative management consisting of scapholunate strengthening exercises. Patients underwent an arthroscopic dorsal capsular tightening of the radiocarpal joint capsule radial to the origin of the dorsal radiocarpal ligament and proximal to the dorsal intercarpal ligament by either thermal shrinkage or dorsal capsule abrasion. Demographic data, radiological outcomes, patient-rated outcome measures and objective measures of wrist range of motion (ROM), and grip and pinch strength were recorded. Postoperative outcome scores were collected at 3, 6, 12, and 24 months. Data are reported as median and interquartile range, and comparisons were drawn between baseline and last follow-up. Clinical outcome data were analyzed using a linear mixed model method, while radiographic outcomes were assessed with nonparametric analysis with p  < 0.05 indicating statistical significance.

Results  Twenty-three wrists (22 patients) underwent SLL treatment by thermal capsular shrinkage (19 wrists) or dorsal capsular abrasion (4 wrists). Median age at surgery was 41 years (range: 32–48) and median follow-up time was 12 months (range: 3–24). Pain significantly decreased from 62 (45–76) to 18 (7–41) and satisfaction significantly increased from 2 (0–24) to 86 (52–92). Patient-Rated Wrist and Hand Evaluation and Quick Disabilities of the Arm, Shoulder, and Hand significantly improved from 68 (38–78) to 34 (13–49) and from 48 (27–55) to 36 (4–58), respectively. Median grip and tip pinch strength significantly increased at final review. Range of movement and lateral pinch strength were satisfactory and maintained. Four patients required further surgery for ongoing pain or reinjury. All were successfully managed with partial wrist fusion or wrist denervation.

Conclusion  Arthroscopic ligament-sparing dorsal capsular tightening is a safe and effective treatment for partial SLL tears. Dorsal capsular tightening demonstrates good pain relief and patient satisfaction while improving patient-reported outcomes, grip strength, and maintaining ROM. Longer term studies are required to determine the longevity of these results.

The management of chronic scapholunate ligament (SLL) tears remains controversial, ¹ particularly for partial SLL tears where few treatment options have been described. Acute tears can be managed with immobilization, closed or arthroscopic reduction and percutaneous pinning, or direct ligament repair. ^{2 3} In chronic SLL tears, these options are often not feasible due to ligament attenuation often requiring reconstruction depending on the severity of the SLL injury.

Multiple arthroscopic techniques have been described for SLL injuries ranging from debridement, ⁴ arthroscopy with percutaneous pinning, ⁵ capsulodesis, ⁶ and ligament reconstruction. ^{7 8} In partial SLL injuries, arthroscopic radiofrequency thermal shrinkage has been used to treat partial or dynamic SLL instabilities. ^{9 10}

Through denaturing collagen and promoting fibroblast activity, thermal shrinkage acts to contract structures that are made of collagen. ¹¹ The orthopaedic application of thermal shrinkage was initially described for arthroscopic stabilization of glenohumeral instability and treatment of anterior cruciate ligament laxity. ^{12 13 14} However, the use of thermal shrinkage in both joints had issues with failure secondary to challenges with immobilization, ^{15 16} recurrence, ¹³ and chondrolysis, ¹⁷ limiting the technique's usage. Due to the feasibility of postoperative immobilization, the technique was trialed in smaller joints such as the ankle and wrist including SLL injuries. While results have varied for other pathology, ^{18 19 20} the management of partial SLL injuries with thermal shrinkage has demonstrated good results. ^{9 10 21 22 23 24}

Previously described thermal shrinkage procedures for chronic partial SLL tear focus on treatment of the SLL itself, ^{9 22 23 24} with capsule and/or extrinsic ligaments tightening. ^{10 21} However, thermal shrinkage of the ligament would produce denervation of the ligament ²⁵ which can negatively impact wrist proprioception. ^{26 27} To avoid SLL denervation, we utilize an arthroscopic thermal shrinkage technique that simulates a Blatt capsulodesis to prevent scaphoid flexion and dorsal intercalated segment instability deformity. Utilizing this technique also preserves the extrinsic ligamentous connection to the proximal row. Herein, we describe the technique and present the short-term outcomes of a novel arthroscopic dorsal capsulodesis.

Methods

A prospective cohort study was conducted from 2012 to 2020. Adult patients (age ≥18 years) diagnosed with chronic partial SLL tears were recruited for the study. Partial SLL tears were diagnosed by a combination of clinical and radiographic examination, with confirmation of findings on arthroscopic evaluation. On arthroscopy, partial injuries were defined as Geissler grade III or less. All patients failed a trial of conservative management consisting of scapholunate (SL) strengthening exercises for at least 3 months. ²⁸ Patients were excluded from the study if a complete tear of SLL was demonstrated or evidence of arthritis was found on arthroscopy.

Surgical Technique

All procedures were completed under general anesthesia with tourniquet. After placing the wrist in traction, a diagnostic arthroscopy of the radiocarpal and midcarpal joints was performed. All arthroscopic procedures were initially performed using dry arthroscopy; however, saline was used during thermal shrinkage. Once the diagnosis was confirmed by arthroscopy, management of the SLL proceeded. Debridement of synovitis was performed in the radiocarpal and midcarpal joints as warranted. If a complete tear (Geissler grade IV) or evidence of SL collapse was found, the procedure was changed to debridement, ligament reconstruction, or salvage operation as indicated.

For both dorsal capsule abrasion and thermal shrinkage, the 1-2, 3-4, and 6-R portals are required. The scope was placed in the 6-R portal, while the 1-2 portal was used as the working portal. A trocar was placed in the 3–4 portal to delineate the ulnar most point of capsular tightening. A wand was introduced into the 1–2 portal for thermal shrinkage, and the dorsal capsule was thermally shrunk in an area between the dorsal intercarpal (DIC) ligament and dorsal radiocarpal (DRC) ligament ( Fig. 1 ). Thermal shrinkage in this area would provide scaphoid extension while preserving the dorsal extrinsic ligament attachments to the proximal row. Dorsal capsular abrasion was used when an unexpected SL lesion was identified and the thermal probe was not available. For the dorsal capsular abrasion, the same technique was employed utilizing a chondrotome for the abrasion. The dorsal capsule underwent thermal shrinkage or dorsal abrasion until bleeding tissue was produced. K-wires were not placed at this time as it would interfere with the postoperative rehabilitation plan. Furthermore, since the primary target of the procedure was the dorsal capsular ligaments, there would be little benefit in SL pinning. The portals were closed with Steri-Strips. The arm was dressed and placed in a short arm volar slab.

Fig. 1.

Diagram indicating area of arthroscopic dorsal capsular treatment. Using the 6-R portal for the scope and a radiofrequency ablator in the 1-2 portal the dorsal capsule is abraded. The area of treatment is between the dorsal intercarpal and dorsal radiocarpal ligaments to prevent disruption of their carpal connections. A trocar can be placed in the 3/4 portal to indicate the ulnar most part of the debridement.

Rehabilitation

Patients were changed to a thermoplastic splint on the first postoperative day for a duration of 4 weeks, removing for strictly controlled range of motion (ROM). Patients were allowed gentle active ROM from 0 degree to 30 degrees of extension. No flexion beyond neutral was allowed. At 6 weeks, an SLL protective strengthening program was commenced. ²⁸ Unrestricted activity was allowed at 12 weeks postsurgery.

Outcomes

The primary clinical outcomes assessed were pain and satisfaction as measured on a 100-mm visual analog scale. Secondary outcomes included:

Clinical Data

• ROM measured with a universal goniometer

• Grip and pinch strength measured on a mechanical strength gauge

• Scaphoid shift test

• Complications and rates of reoperation or salvage.

Patient-Reported Outcomes

• Function using:

  • - Patient-Rated Wrist and Hand Evaluation (PRWHE)

  • - Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH)

• Perceived change in function and symptoms using a global rating of change (GRC) scale.

All outcomes were assessed preoperatively, then at 3, 6, 12, and 24 months after surgery. Radiographic outcomes including SL gap on static and clenched views, SL angle, capitolunate (CL) angle, and radiolunate (RL) angle were assessed preoperatively and at last available follow-up.

Statistical Analysis

Demographic and outcome data are presented as median and interquartile range (IQR) or frequency and percentage for continuous and ordinal data, respectively. Each clinical outcome was compared with each study time point using a linear mixed model method. Radiographic outcomes were assessed with the nonparametric Wilcoxon's signed-rank test. Significance was defined as p  < 0.05 for all statistical analysis.

Results

Demographics

Twenty-three wrists in 22 eligible patients were recruited for the study ( Table 1 ). Patients were predominately male with a median age of 41 years (32–48 years). The time from injury to surgery ranged from 5 months to 7 years postinitial injury. Geissler grade II injuries were the most frequent severity of injury found on arthroscopy representing 68% of patients. The median follow-up of the group was 12 months (range 3–24 months).

Table 1. Patient demographics.

N	Age median (IQR)	Gender (M:F)	Injured hand (R:L)	Interval from injury to surgery	Arthroscopic Geissler grade of SLL injury	Procedure	Follow-up median (IQR)
23	41 (32–48)	13:10	17:6	18 (10–24)	II—20 III—3	Thermal—19 Abrasion—4	12 (6–24)

Abbreviations: IQR, interquartile range; SLL, scapholunate ligament.

Patient Pain and Satisfaction

Pain with normal activity significantly improved over the course of follow-up from a preoperative value of 62 (45–76) to 18 (7–41) at 2-year follow-up ( p  < 0.001). Pain at rest (22 [4–50] to 4 [2–28], p  = 0.035) and worst pain (83 [74–90] to 63 [54–76], p  = 0.006) also significantly improved over the course of follow-up. Night pain improved but did not reach statistical significance over the follow-up period ( p  = 0.06). Patient-reported satisfaction significantly improved from 2 (0–24) to 86 (52–92) over the course of the study ( p  < 0.0001). Fig. 2 illustrates pain relief and patient satisfaction across pre- and postoperative study intervals.

Fig. 2.

Visual analog scale (VAS) of patient pain and satisfaction at pre- and postoperative intervals. p  < 0.0001.

Range of Motion and Strength

Patients in our series maintained ROM in all planes at 2-year follow-up ( Table 2 ). Grip strength (28 [15–47] to 29.84 [24.5–48.5], p  = 0.045) and key pinch (4.5 [2.9–5.4] to 5 [3–8.8], p  = 0.043) were significantly improved at 2-year follow-up. Lateral pinch was unchanged from preoperative values at final follow-up. The scaphoid shift test significantly improved in the postoperative period (6 positive vs. 0 positive; p  = 0.011).

Table 2. Range of motion and grip strength data.

	Preoperative	3 mo	6 mo	12 mo	24 mo	p -Value
Range of motion
Flexion	62 (45–82)	57 (45–72)	56 (50–70)	65 (51–78)	63 (43–77)	0.79
Extension	60 (46–77)	65 (58–70)	65 (58–70)	71 (55–75)	81 (53–85)	0.23
Radial deviation	15 (12–20)	20 (12–23)	20 (16–24)	18 (14–20)	14 (11–23)	0.08
Ulnar deviation	30 (24–40)	30 (28–32)	30 (25–36)	32 (30–40)	31 (24–37)	0.84
Supination	85 (75–90)	88 (84–90)	89 (86–90)	85 (80–90)	90 (88–90)	0.44
Pronation	85 (77–90)	85 (75–90)	85 (80–90)	90 (83–90)	90 (85–92)	0.38
Grip strength
Grip strength (kg)	28 (15–47)	38 (25–43)	33 (24–48)	35 (27–44)	30 (25–49)	0.045
Tip-to-tip pinch (kg)	4.5 (2.9–5.4)	4.6 (3.6–5.1)	5 (4–6.8)	5 (3–6.5)	5 (3–8.8)	0.043
Lateral pinch (kg)	6.3 (4–9)	7.5 (5–8.5)	6.5 (5.5–8.3)	6.5 (4.8–8.5)	7 (5–8.5)	0.42

Note: Bold indicates a statistically significant change ( p <0.05)

Functional Outcomes

The PRWHE total score, PRWHE pain score, and PRWHE function score all significantly improved over the study ( Fig. 3 ). The PRWHE total score improved from 68 (37.5–78) to 34 (13–49) ( p  < 0.0001). Similarly, the PRWHE pain score improved from 36 (24–40) to 24 (12–27) ( p  < 0.0001) and the PRWHE function improved from 32 (14–38) to 14 (3–26) ( p  = 0.0001). The QuickDASH total score also improved over the follow-up period from 47.73 (27.27–54.55) to 36.37 (4.55–57.96) ( p  = 0.041). At latest follow-up, median GRC scores were 4 (“moderately better”) for both symptoms (IQR 3–7) and function (IQR 2–6), compared with presurgery.

Fig. 3.

Patient-Rated Wrist and Hand Evaluation (PRWHE) and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) at pre- and postoperative intervals.

Radiographic Outcomes

SL gap was maintained at a median of 2 mm but with a lower IQR in the postoperative group which made the difference statistically significant ( p  = 0.046). SL gap on clenched fist views demonstrated an improvement from 3 (2–4) to 2 (2–3), but this was not statistically significant ( p  = 0.15). There was a trend toward improved RL angle (from 13 [7–18] to 7 [3–22]), but this failed to reach statistical significance ( p  = 0.41). There was no significant difference in preoperative/postoperative SL angle (from 56 [50–63] to 57 [51–64] [ p  = 0.66]) and CL angle (from 20 [12–22] to 19 [11–27] [ p  = 0.77]).

Complications and Salvage

There were no immediate complications from surgery; however, four patients required a further procedure ( Table 3 ). One patient required a partial wrist fusion for an injury postoperatively. Three patients had ongoing pain postprocedure. Two of these patients required a partial wrist fusion and one was managed with a wrist denervation. All patients who required a partial wrist fusion were treated with an RL fusion with excision of the scaphoid and triquetrum. The partial wrist fusions were performed between 7 and 19 months after the procedure, while the wrist denervation was performed at ∼2 years. Of the four patients requiring salvage, two were Geissler grade II (2/15, 13%) and two were Geissler grade III (2/5, 40%).

Table 3. Complications and salvage procedures.

	Description	Total
Immediate postoperative complications	n/a	0
Patients requiring salvage procedure	Total	4
	Geissler grade II	2
	Geissler grade III	2
Salvage procedure (median time to salvage)	RSL fusion (14 mo)	3
	Denervation (21 mo)	1

Abbreviation: RSL, radioscapholunate.

Discussion

The management of chronic partial SLL tears remains variable. ²⁹ Thermal shrinkage was initially described for knee and shoulder pathology. ^{12 14} However, the technique has fallen out of favor due to complications of chondrolysis and recurrent instability. Arthroscopic thermal shrinkage techniques for partial SLL tears have not demonstrated issues with chondrolysis and recurrence, perhaps due to the possibility of more effective postoperative immobilization.

Our series of patients demonstrated improved pain and patient-reported outcomes with high patient satisfaction and maintenance of ROM and carpal alignment. These results appear to be consistent with previous reports in the literature. Burn et al ²¹ demonstrated improved QuickDASH while maintaining ROM in nine patients over a minimum of 5 years follow-up, the longest follow-up to date. In a series of 19 wrists, Shih and Lee ²⁴ demonstrated high patient satisfaction while preserving ROM and improving grip strength with other studies finding similar results. ^{9 23} Overall need for salvage procedure was low in other studies of thermal shrinkage.

The presence of a higher arthroscopic grade of SL tear was found to be associated with a higher rate of salvage procedures, with 40% of patients with grade III SL tears requiring salvage compared with 5% in grades I and II SL tears. The higher rate of conversion to salvage procedures in grade III tears indicates that this procedure may be best suited for grades I and II SL tears.

The surgical technique was designed to replicate a Blatt capsulodesis by thermally shrinking the dorsal radial capsule which offers multiple advantages. Thermal shrinkage of the dorsal radial capsule will cause the scaphoid to extend, contributing to restoration of normal carpal alignment as the dorsal capsule contracts. By completing the procedure arthroscopically, scarring to the rest of the dorsal capsule and dorsal ligaments is minimized, potentially improving ROM. Patients in our series demonstrated maintained ROM which can be lost in other forms of open capsulodesis procedures. ^{30 31}

The section of dorsal capsule that undergoes thermal shrinkage is bordered by the DIC and DRC. By only treating the window of capsule between the two ligaments, the ligamentous attachments of the DIC and DRC to the proximal row are preserved. The proximal row connections of these ligaments play an important role in maintaining carpal alignment, ³² and it is crucial to leave these attachments intact in SLL repair and reconstruction.

This technique avoids thermal shrinkage of the SLL itself to maintain any residual innervation to the ligament. Thermal shrinkage of the SLL and dorsal capsule would cause a denervation of the treatment area. ²⁵ While this may have a role in the analgesic effect of the procedure, it would also affect the proprioceptive nerve fibers of the joint. ^{26 27} Maintaining joint proprioception has an important role in the rehabilitation of SLL injuries. ³³ By not thermally shrinking the SLL, these fibers should be preserved, particularly the densely innervated volar portion of the ligament. ³⁴ The significant pain relief demonstrated by our series highlights that the pain relief from thermal shrinkage is not purely from a joint and ligament denervation process.

There are several limitations to the study. There were several patients lost to follow-up particularly for the later follow-ups which could have impacted results. Additionally, a study follow-up period of 2 years may be insufficient to fully capture patients who may require a salvage procedure.

Conclusion

Partial tears of SLL can be effectively managed with arthroscopic treatment of the dorsoradial capsule. Both arthroscopic dorsal capsular abrasion and thermal shrinkage can offer a reliable method of improving function and relieving pain with minimal comorbidity in Geissler grade I or II partial SL injuries.

Funding Statement

Funding The authors received no financial support for the research, authorship, and/or publication of the article. The Brisbane Hand and Upper Limb Research Institute receives institutional support and fellowship support from Newclip Technics, Johnson & Johnson (DePuy Synthes), Exactech, Integra LifeSciences, and LMT Surgical.