Abstract
Purpose
We aimed to compare radiological and clinical results between patients diagnosed with Intraosseous ganglion cysts of the lunate (IGCL)-treated arthroscopic dorsal ligamento capsulodesis (ADLC) with or without grafting.
Methods
26 patients who underwent wrist arthroscopy with the diagnosis of intraosseous ganglion cysts of the lunate were included in the study. The patients in the series were divided into two groups according to the surgery they underwent: patients who underwent isolated ADLC in group A and ADLC with autografting in group B. The wrist range of motion, patient satisfaction, Visual Analogue Scale (VAS) and the Mayo Wrist Score (MWS) were used for clinical and functional results.
Results
Group A consisted of 12 (7 females - 5 males), Group B consisted of 14 (9 females - 5 males). The mean age was 33,1 years in Group A (range 22-49), and 32,3 years in Group B (range 21-47). The VAS, Mayo Wrist Score, wrist range of motion, and the level of patient satisfaction were similar in the two groups. In Group A, the postoperative mean cyst diameter (CD) was 4.2 (range: 1.3 – 7.3 mm), comparable to the mean cyst diameters before surgery. In Group B, trabeculation was observed in 13 patients, and CD was not calculated. Only one patient in Group B had a 3.5 mm (preoperative 3.6 mm) cyst, attributed to graft lysis.
Conclusion
As we have observed scapholunate instability at different stages in this case series diagnosed with IGCL, we believe that the source of pain is related to instability and treatment should focus on the existing instability. This hypothesis is supported by our obtaining similar results when comparing only ADCLs for instability, which were chosen according to our clinical experience, with those who underwent ADCLs with bone grafting.
Keywords
Introduction
Intraosseous ganglion cysts of the lunate (IGCL) are uncommon benign conditions with an unclear etiology. Schajowicz et al. classified these cysts into Type I (intraosseous, idiopathic) and Type II (juxta-articular, penetrating). 1 While these cysts are typically asymptomatic and are often incidentally discovered on radiographs obtained for other purposes, they can occasionally lead to symptoms. 2 The origins of wrist ganglion cysts have long captivated researchers, with a prominent focus on carpal instability attributed to intrinsic (scapholunate-lunotriquetral) or extrinsic (capsular) damage or laxity of carpal ligaments. Mechanical stress and repetitive minor trauma contribute to intraosseous myxoid degeneration, involving the migration of unidentified local factors from ligaments into the carpal bone.1,2 Despite the historical prevalence of this perspective, there is a notable scarcity of studies addressing open or arthroscopic curettage and grafting of the cyst, as well as investigations into the diagnosis and treatment of potential instability. 3 Existing literature reports failure rates ranging from 8 to 40% following surgery, often without a clear explanation.4–7 We posit that one contributing factor to these failures is the oversight of etiological treatment.
In this retrospective study, our objective was to assess and compare radiological and clinical outcomes in patients diagnosed with IGCL undergoing arthroscopic dorsal ligamento capsulodesis (ADLC) treatment, with or without autograft grafting.
Methods
We conducted a retrospective review of patient databases from a singular tertiary institution, encompassing the years 2015 to 2023 focusing on those who underwent arthroscopic wrist surgery with a diagnosis of IGCL. The analysis included a thorough examination of medical records and radiological data. Prior to data collection, ethical approval was obtained from the Institutional Review Board, and all participants provided informed consent. Inclusion criteria encompassed patients who had previously undergone unsuccessful conservative treatments, a follow-up period exceeding 12 months and were subsequently diagnosed through magnetic resonance imaging. Conservative treatment including activity modification, wrist splinting (night or full time), avoidance of heavy movements that would cause wrist pain for 3 months, and NSAID medication during painful periods. Exercises to strengthen the muscles around the wrist and increase ROM were performed in the presence of a hand specialist physiotherapist. At the end of 3 months, patients who responded positively to conservative treatment were extended to 6 months, while patients who did not respond were offered surgery. Type I (intraosseous, idiopathic) cysts, cyst volume greater than 50% of lunate volume on CT, cyst in other carpal bones, diagnosis of bilateral IGCL, ulnar localized cyst in lunate, cysts developing secondary to diseases such as rheumatologic, arthrosis, infection, patients who had previously been operated with open surgery, or had missing records were excluded from the study.
Patients did not experience pain at rest, but they reported discomfort and functional limitations during routine daily activities. General wrist pain was exacerbated by passive wrist movements, particularly during extension.
The patient cohort was stratified into two groups based on the type of surgery they received: Group A comprised patients who underwent isolated ADLC, while Group B consisted of those who underwent ADLC with autografting.
Surgical technique
Portals for working and viewing included 1-2, 3-4, 6R, midcarpal radial (MCR), and midcarpal ulnar (MCU). A 2.4-mm, 30-degree arthroscope (Arthrex, Naples, FL, USA) visualized the radiocarpal joint, focusing on the radioscapholunate joint level and the scapholunate (SL) ligament complex, including the Testut and Kuenz ligaments.
In Group A, midcarpal joint imaging was done without exposing the cyst. The SL and LT joints were examined using a 3-mm hook probe through the MCR portal (Figure 1). SL ligament tears were classified using Geissler and EWAS classifications.6,7 Dorsal ligamentocapsulodesis was performed using Mathoulin’s technique
4
for isolated SL tears. For additional LT tears, combined SL-LT dorsal ligamentocapsulodesis by Ozcelik et al.
5
was used. A 3/0 PDS suture was threaded through an 18-gauge needle outside the joint. Using the radiocarpal 3-4 portal, the needle with suture was inserted into the midcarpal joint, passing through the dorsal wrist capsule and SL ligament’s dorsal fragment attached to the scaphoid’s dorsal horn. A second needle followed the same process (Figure 1(C)). Both sutures were retrieved from the MCR portal using a hemostat, passing through the dorsal wrist capsule, and knotted. In cases without an LT tear, finger traps were removed, and proximal traction positioned the knot on the SL ligament. A second knot was tied while the wrist was extended. For LT tears, the process was mirrored using the 6R portal, passing through the dorsal wrist capsule and LT ligament’s dorsal fragment attached to the lunate’s dorsal horn (Figure 2). A knot was tied between the sutures’ distal ends. After removing finger traps, proximal traction positioned the knot on both SL and LT ligaments (Figure 3). A second knot was tied at the SL and LT ligaments while the wrist was extended Figures 4–6. (a) Intraosseous cyst of the lunate bone (yellow arrow) (b) Remove the sutures from the radiocarpal portal to the midcarpal portal to preserve the dorsal portion of the ligament through the midcarpal portal. (c) The two proximal ends of the knot thread are released (blue and green arrows) and the distal portion of the knot thread removed at the midcarpal joint is sutured (brown arrow). (a) While the optic is in the 3-4 portal, the sutures are passed through the 6R radial portal to the U-MCU portal. (b) The two proximal ends of the knot thread are released (blue and green arrows) and the distal portion of the knot thread removed at the midcarpal joint is sutured (brown arrow). (a) Placement of distal sutures on the SL (purple arrow) and LT (blue arrow) ligaments. (b) Place the suture dorsal to the ligament by connecting the distal sutures. (c) Placement of proximal sutures on the SL (purple arrow) and LT (blue arrow) ligaments. (d) proximal localization of the knot and capsulodesis of the capsule to the ligament after sutures are connected proximally. A-B: Shaver debridement of the estimated localization of the cyst opening into the joint. C: The lunate cyst was evaluated under needle guidance. Debridement of the cyst interior with Burr under fluoroscopic control. Arthroscopic view of lunat cyst.
In Group B, cancellous bone graft was removed from the olecranon using a Jamshidi trocar. After radiocarpal joint evaluation similar to Group A, 1-2 process portals were opened to view the SL joint and cyst from the opposite side. The juxta-osseous cyst was accessed through the SL joint’s membranous part. Shaver-burr assisted debridement was performed and a biopsy taken with arthroscopic forceps. A dry environment was preferred to prevent graft falling into the wrist joint during grafting. The cyst was filled with trocar-assisted cancellous bone grafts from the same portal. All subsequent dorsal ligamentocapsulodesis procedures continued as dry arthroscopy, following the same steps as in Group A.
Postoperative management
The wrist was postoperatively placed in a short arm cast at slightly extension, allowing metacarpophalangeal joint motion for 3 weeks. Then, a 3-week full-time prefabricated wrist splint was used. After a total of 6 weeks of wrist immobilization, a similar rehabilitation program was applied by a physiotherapist specializing in hand rehabilitation. After passive ROM exercises of the wrist were started for a week, active ROM was then progressively allowed. To give the ligaments the time to heal without being stretched out, forced flexion was specifically prevented for the first 3 months. Strengthening exercises were performed 3 months postoperatively.
Radiological assessment
The presence of cyst was detected by wrist posteroanterior (PA) and lateral radiological and computed tomography (CT) evaluation. The diameter of the cyst (CD) on PA X-ray was accepted as the diameter of the largest transverse distance between the sclerotic areas. Diameter of lunate (LD) was measured using the “measured from the baseline on the lunate which runs from the ulnar tip of the distal facet to the radial tip of this facet” method.
8
The CD/LD ratio was determined as a percentage (Figure 7). Contrast-enhanced magnetic resonance imaging (MRI) was also used to better understand the intraosseous configuration of the cyst, to make the differential diagnosis from other pathologies in the carpal bones, and to recognize additional soft-tissue pathologies. Cyst volume (CV) in CT was measured with the most published and reliable method, the Cavalieri principle and the planimetry technique.
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Lunatum reference volume (LV) was accepted as 1362 mm3 in women and 2252 mm3 in men.
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CV/LV was determined as a percentage. All CT and MRI scans were examined by a radiologist who specialized in musculoskeletal radiology. Cyst diameter was determined according to lunatum diameter.
Clinical outcome measures
Both flexion-extension degrees of the patients were measured comparatively with a universal standard goniometer. Hand grip strength was examined preoperatively and at the final follow-up with a Jamar hand dynamometer (Sammons Preston, Bolingbrook, IL, USA). The level of patient satisfaction with the surgery was rated as very disappointing, disappointed, somewhat satisfied, satisfied, or very satisfied. The return of the patients to their previous occupations or the change of profession due to this complaint was questioned. Intra or postoperative complications were recorded. The functional outcome measure was determined by The Mayo Wrist Score (MWS) 11 and Visual Analogue Scale (VAS). The return of the patients to their previous occupations or the change of profession due to this complaint was questioned. Intra or postoperative complications were recorded.
Statistical analysis
IBM Statistical Package for the Social Sciences (SPSS) for Windows 28.0 was used for the analysis of the study data. The normality of distribution was tested using the Shapiro-Wilk test. A paired t test was performed to assess the variation in VAS scores and MWS score. An independent t test or Man-Whitney U test was performed to compare age, radiological parameters. Fisher’s exact test was performed for the categorical data between the two groups. The level of significance was set at 5%, where p < .05 was considered statistically significant.
Result
Demographic data of patients.
Min: Minimum, Max: Maximum; SD: Standard deviation.
Comparison of radiological parameters between the groups.
Min: Minimum, Max: Maximum; SD: Standard deviation.
All patients in both groups exhibited synovitis of varying degrees in the radiocarpal joint, resulting in synovitis-induced swelling of the SL ligament and a convex configuration between the carpal bones. In both groups, four patients exhibited evidence of synovitis and swelling in the LT ligament. In Group B, the cyst was curetted from the intermediate portion of the SL, and a yellowish viscous gelatinous material was observed in all patients. A biopsy was subsequently obtained.
Intraoperative arthroscopic findings.
In Group B, SL ligament tears were graded as follows: grade I in two patients, grade II in seven, and grade III in five. For LT tears (four patients), grades were as follows: grade I in two patients, grade II in two, and grade III in one. According to the EWAS classification, SL ligament tears in Group B were stage I in one patient, stage II in seven, stage III-A in one, stage III-B in one, and stage III-C in four. SL rupture was categorized as partial in nine patients and total in four.
The mean surgical time was 29.4 minutes (range: 24-37) in Group A and 72.2 minutes (range: 63-88) in Group B (p < .001).
Clinical and functional results of both groups.
Min: Minimum, Max: Maximum; SD: Standard deviation.
Only one patient in group B had paresthesia that resolved spontaneously within 3 months, corresponding to the dorsal radial sensory branch.
Discussion
There is no consensus in the treatment modality of lunate cyst. Prior to advances in wrist arthroscopy, symptomatic IGCLs were curetted and grafted using a dorsal or volar open approach. 3 According to arthroscopic methods, this approach has disadvantages such as wrist stiffness, scarring, vascular disorders of the lunate and carpal instability due to SL ligament injury, and high rates of recurrence (40%) and complications (14%) have been reported. 3 Ashwood et al reported a retrospective review of the case series of eight patients (mean follow-up 45 months), they observed favourable changes in ROM, grip strength, pain and functional outcomes, and they encountered no recurrence or complications. 12 In the following years, similar results were reported with similar methods, but none of these studies provided data on ligament laxity or carpal instability.12–15 In order not to create a new defect on the cartilage surface, Bhatia et al. opened a 3.2 mm bone tunnel from the lunatum dorsal nonarticular surface and reached the cyst with a direct cystoscopic approach. 16 With similar concerns, Prenaud et al. described a new technique in which they directly reach the cyst by passing the intermediate portion of the SL ligament. 17 Both authors presented their methods only as surgical techniques and did not conduct studies on clinical and radiological results.
While failure rates of up to 30% have been reported in soft tissue ganglia treated with the arthroscopic approach, there is no literature yet showing the failure rate because the number of intraosseous ganglia treated with a similar approach is quite low. 18 The largest series in this area was published by Edward et al. who observed SL and LT instability at different stages with an arthroscopic examination in all their 55 soft tissue ganglion cyst patient series. 19 Ribau el at. Suggested that SL laxity may play a role in the etiology of soft tissue ganglion, even if there is no tear in the Geissler classification, and ADLC procedure may provide potential benefit for this laxity. 20 In that study, they compared the result of isolated ganglion excision and ganglion excision with ADLC procedure. They found that the clinical results to be similar, but lower recurrence was observed in cases with ADLC. There is only one study that draws attention to occult wrist instability in patients with intraosseous ganglia located in the carpal bones 20 Zhao et al. applied arthroscopic thermal shrinkage by detecting SL instability between stages I and II in all his series of 14 cases (only 5 of them are inside the lunate). 21 He reported good functional results and no recurrence or complication. We performed standard radiocarpal and midcarpal joint arthroscopy in all our symptomatic patients diagnosed with IGCL with the hypothesis of carpal instability-intraosseous ganglion cyst association, which needs further investigation. We detected SL-LT instability at different stages in all patients in both groups and performed isolated SL or combined SL-LT ADLC. However, the application of a similar technique for the LT joint is a newer application with good results.22,23
Uriburu et al. reported that cysts should be grafted and that strong axial loads on the wrist with bone grafting may cause pathological fractures in the lunate, making the treatment even more difficult. 24 In these cysts, grafting is usually performed with autograft or allograft by opening a window from the contralateral iliac wing or ipsilateral radius with an osteotomy. 3 In the group in which we used grafts in our study, we obtained cancellous bone grafts from olecranon. It has been proven that this technique causes less donor site morbidity compared to open techniques. 25 Most of the previously described IGCL treatment modalities report that the cyst should be grafted. 3 There is limited literature information about grafting diameter. In the discussion part of the technical note published by Bhatia, maintenance of structural cortical integrity avoids the necessity of bone graft supplementation in most cases, but this opinion is subjective and did not present its results. 15 Zhao et al. reported that it would not be necessary if the cyst diameter is less than half of the carpal bone. 21 It is not clearly understood which cysts were grafted and which ones were not grafted in the 5 lunate cyst groups of the 9-case study that presented good results. Since there was no comparison between the groups with and without grafting in both studies, the difference between clinical results is not understood.
Different evaluation methods such as cyst diameter, cyst volume, and cyst index have been defined for the size of intraosseous cysts in the literature. 9 The detection of a cyst that can cause a pathological fracture by evaluating all these factors together can only be understood with a sense clinical approach. Before 2018, they were not grafting some cysts with a pure sense clinical decision taken by the senior author with the thought that opening a cartilage window for cyst grafting would cause additional morbidity on the lunate cartilage surface. In our series, with a mean cyst diameter (CD/LD%) of 29% in the non-graft group and 30% in the graft group, no clinical or functional difference was found between the two groups.
In the radiological comparison of the two groups, we observed that the presence of the cyst persisted in the non-grafted group, but the CD/LD ratio did not change. In the transplanted group, trabeculation was observed in 11 patients, while the presence of the cyst (same size as the preoperative CD) persisted in one patient. Although these results suggest that grafting is radiologically superior, we believe that some cysts do not require grafting, with some advantages such as the same clinical results, no window opening on the lunate cartilage surface to reach the cyst, shorter operative time, no additional costs such as allografts or donor site morbidity, and elimination of the fear of grafts placed in the cyst falling back into the joint space.
Of course, we are aware that our hypothesis may be somewhat controversial. The patient group in question attributes the pain they experience to the lunate cyst at the time of initial presentation. However, our hypothesis is that the underlying cause is instability, with the cyst representing a consequence of this instability. Similarly, a study conducted by Ayik and colleagues. 26 Investigated the efficacy of treating instability without excising occult soft-tissue ganglia. It is our contention that the source of pain is related to instability, and that treatment should therefore focus on the existing instability.
The limitation of our study are its retrospective character and the lack of randomization. Final controls of the patients were made with plain X-ray only, not with MRI or CT. Another limitation is that while medium-long-term results are presented in Group A, short-mid-term results are presented in Group B. More patient numbers and longer-term results will make our study more valuable.
Conclusion
In patients with symptomatic IGCL unresponsive to conservative treatment, our approach extends beyond mere curettage-grafting of the cyst. It necessitates a thorough evaluation of both the radiocarpal and midcarpal joints, addressing any identified carpal instabilities. As we have observed scapholunate instability at different stages in this case series diagnosed with IGCL, we believe that the source of pain is related to instability and treatment should focus on the existing instability. This hypothesis is supported by our obtaining similar results when comparing only ADCLs for instability, which were chosen according to our clinical experience, with those who underwent ADCLs with bone grafting.
Footnotes
Authors contribution
Ö.A. Conceptualization, Methodology and Writing- Original draft preparation S.B. Data curation; Formal analysis, critical revision A.E.P. Data curation, Formal analysis; İ.B.Ö. Supervision and Critical revision;
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
