Sauve-Kapandji Remains a Viable Option for Distal Radioulnar Joint Dysfunction

Abstract

Introduction

Dysfunction of the distal radioulnar joint (DRUJ) can be significantly debilitating. The Sauve-Kapandji (S-K) procedure can be indicated to address multiple etiologies of DRUJ dysfunction. The purpose of this study was to review our institution’s results performing the S-K procedure for DRUJ dysfunction in terms of clinical and radiographic outcomes, as well as complications and reoperations.

Methods

A retrospective review of S-K procedures performed at 2 institutions between 1998 and 2017 with a minimum of 1-year follow-up was performed. Preoperative and postoperative visual analog scale (VAS) pain, grip strength, and wrist range of motion were reviewed. Radiographs were reviewed for DRUJ healing, carpal translation, and radiocarpal degenerative changes.

Results

The cohort included 35 patients. The mean age was 51 years. The mean follow-up was 49.5 months. The postoperative range of motion was unchanged in regard to pronation, supination, and wrist extension. There was a decrease in wrist flexion from 43 degrees to 34 degrees. Successful union was noted in 100% of the wrists. There was 1 case (2.8%) of progressive ulnar translation and 4 major complications (11.3%).

Conclusion

The S-K procedure has several theoretical benefits compared to other procedures for DRUJ dysfunction with results of this study demonstrating excellent pain relief, improved postoperative grip strength, retained wrist pronation, supination, and extension, high rate of successful arthrodesis and low rate of major complications.

Level of Evidence

Level IV

Introduction

Dysfunction of the distal radioulnar joint (DRUJ) can be significantly debilitating. Various surgical treatment options exist with no clear superiority of any procedure reported in the literature.^1-3 These options include resection arthroplasty, interposition arthroplasty, ulnar head arthroplasty, creation of a one-bone forearm, and the Sauve-Kapandji (S-K) procedure, which involves an osteotomy and resection of the distal ulna proximal to the articular surface with arthrodesis of the DRUJ.^1-5 The S-K procedure provides several theoretical advantages, including maintenance of the ulnar support of the carpus, the ability to shorten the ulna if needed, preserving normal force transmission through the wrist, and a relatively short period of immobilization.^1-3,6,7

The S-K procedure can be indicated to address multiple etiologies of DRUJ dysfunction including rheumatoid arthritis, osteoarthritis, posttraumatic arthritis, and congenital malformations and several studies have shown promising results.^2,4,6,8-14 However, these are limited by small sample sizes and short follow-up duration. Specifically, several studies have reported a reliable rate of pain relief, improved patient functional scores, and a relatively low rate of complication.^{2,4,6,8,10,11,14,15} Nonetheless, these studies often have small sample sizes and report varying outcomes, limiting the ability to perform a reliable systematic analysis to guide surgeon understanding and treatment algorithms.

The purpose of this study was to review our institution’s results performing the S-K procedure for DRUJ dysfunction in terms of clinical and radiographic outcomes, as well as complications and reoperations.

Materials and Methods

Following institutional review board approval, a retrospective review of patients who underwent S-K procedure at 2 institutions (Mayo Clinic Rochester and Mayo Clinic Arizona) involving multiple surgeons from 1998 to 2017 was performed. The medical record was reviewed to determine patient demographics, procedural details, preoperative and postoperative hand clinical data, and complications. Clinical exam was correlated with x-ray imaging to confirm the diagnosis of DRUJ arthritis rather than ulnar impaction or triangular fibrocartilage complex injury. Magnetic resonance imaging (MRI) was not routinely performed. Pain was evaluated using the visual analog scale (VAS) during each clinic visit. ¹⁶ Range of motion and grip strength data were measured by orthopedic surgery residents, fellows, and consultants including wrist flexion/extension, radial and ulnar deviation, forearm supination, and pronation. Grip strength was recorded using a dynamometer in kilograms (Jamar, Cambridge, Massachusetts). Radiographs were reviewed for DRUJ arthrodesis site union, progressive postoperative ulnar carpal translation, and radiocarpal degenerative changes at time of final follow-up. Ulnar carpal translation was assessed using the “lunate uncovering index.” ¹⁷ An increase of > 10% on final follow-up radiograph versus the preoperative radiograph was considered progressive ulnar carpal translation. Any complications were noted and analyzed.

Statistical Analysis

Descriptive statistics were used to summarize the data and outcome measures. Nominal variables were compared with contingency analysis using chi-squared test, or a student 2-tailed unequal variance t test was used to compare nominal and continuous variables and outcomes. The α level was set to 0.05. All statistical analyses were conducted using JMP, Version 13.0.0 (SAS Institute Inc., Cary, North Carolina), 1989 to 2007.

Surgical Technique

A longitudinal incision is utilized over the dorsal-ulnar aspect of the wrist. The extensor retinaculum is exposed and approached through the fifth compartment. The extensor digiti minimi is retracted to allow access to the distal radioulnar joint capsule. The capsule is split and raised via an “L-shaped” flap. This will provide visualization of the DRUJ.

The arthritis is debrided from the joint by removing sclerotic bone at the sigmoid notch as well as the ulnar head. This can be achieved with curettes, ronguers, and in some instances, high speed burrs. Contouring the sigmoid notch to the ulnar head will help maximize bony contact and set the ulnar head in a reduced position.

Resection of the ulna proximal to the ulnar head is performed. One centimeter or less is resected proximal to the ulnar head using an oscillating saw (Figure 1). It can later be used as bone graft with or without supplemental allograft at the arthrodesis site.

Figure 1.

One centimeter or less of ulna proximal to the ulnar head is resected.

The ulnar head and radius are then provisionally pinned. The guide-pin is inserted from the ulnar aspect of the ulna into the radius. Fluoroscopy will ensure: (1) appropriate position of the ulnar head with respect to opposition and reduction at the sigmoid notch; and (2) neutral ulnar variance. Upon confirmation of the alignment and bony contact, a 3.5 or 3.0 mm partially threaded cannulated screw with a washer is inserted over the guide-pin (Figure 2). If room allows, a second screw can be inserted. Alternatively, a threaded 0.062 or 0.054 k-wire can supplement the fixation. See Figures 3 and 4 for preoperative versus 9 months postoperative image.

Figure 2.

Two partially threaded, cannulated screws are used to fixate the ulnar head.

Figure 3.

Preoperative AP radiograph demonstrating DRUJ arthritis.

Note. AP = Anterior Posterior; DRUJ = Dysfunction of the distal radioulnar joint.

Figure 4.

Nine-month postoperative AP radiograph status post S-K procedure.

Note. AP = Anterior Posterior; SK = Sauve-Kapandji.

The proximal ulnar stump is evaluated to ensure that there are no prominent of sharp edges. If so, they should be smoothed down. The ulna can be stabilized with local soft tissues, such as the pronator or wrist extensor/flexor tendons. Plication of the dorsal capsule can be performed while reducing the ulnar stump positioned volarly. Given that multiple surgeons at 2 different institutions were involved in the surgical cohort, distal ulnar stabilization methods were heterogeneous, however. Although plication of the dorsal capsule was common, some surgeons did perform stabilizations including extensor carpi ulnaris/flexor carpi ulnaris, pronator, or brachioradialis. The retinaculum of the fifth compartment is re-approximated with the extensor digiti quinti reduced inside it. Following skin closure, the forearm is placed in a sugar tong splint for approximately 2 weeks and then transitioned to a Muenster cast for 2 to 4 weeks to allow for scarring and protect the fusion mass. Radiographs were reviewed to ensure stable alignment and early callus formation. Thereafter, the patient can be placed in a removable Muenster splint and begin a therapy program. This consists of therapy focusing on active wrist motion and forearm pronation and supination. Once the patient achieves 45 degrees of pronation and supination, the Muenster splint is discontinued besides for comfort. After 4 to 6 weeks (or approximately 10-12 weeks postoperatively), the patient may begin strengthening and progress activities over the next 2 to 4 weeks.

Results

Patient Demographics

Thirty-five patients underwent the S-K procedure during this time with 1-year follow-up. The mean age at time of surgery was 51 years (range = 17-78), and the cohort included 30 females and 5 males. The mean follow-up was 49.5 months (range = 12-217). The indication for surgery was inflammatory arthritis in 22 wrists, posttraumatic osteoarthrosis in 5 wrists, osteoarthritis in 4 wrists, and congenital malformation in 4 wrists.

Clinical Outcomes

At final follow-up, the mean pain scores improved significantly from 6.5 preoperatively to 1.3 postoperatively (P < .001). There was complete resolution in pain in 64% of patients, and 91% of patients experienced pain relief, with only 9% having no pain relief or increased pain after surgery.

Mean grip strength improved from 9 kg (range = 2-20) preoperatively to 13 kg (range = 3-25.5) postoperatively (P = .004). Preoperative versus postoperative range of motion was improved in regard to pronation (70.3 degrees-78.3 degrees, P = .72), supination (49.8 degrees-60 degrees, P = .69), and wrist extension (38.6 degrees-39 degrees, P = .74), but these did not reach statistical significance. There was, however, a decrease in wrist flexion at final follow-up from 43 degrees preoperatively to 34 degrees postoperatively (P = .01). See Table 1 for a summary of clinical outcomes.

Table 1.

Outcomes of S-K Procedure.

Outcome measure	Preoperative	Postoperative	P value
Visual analog score	6.5	1.3	<.001
Grip strength, kg	9	13	.004
Pronation, degrees	70.3	78.3	.72
Supination, degrees	49.8	60	.69
Wrist extension, degrees	38.6	39	.74
Wrist flexion, degrees	43	34	.01

Note. Significant P values in bold. S-K = Sauve-Kapandji.

Radiographic Analysis

When assessing the arthrodesis radiographically, successful union was noted in 100% of the wrists. One patient (2.8%) had progressive ulnar carpal translation compared to preoperatively at final radiographic follow-up with a 20% increase in lunate uncovering index in this patient postoperatively. No cases of radial carpal translation were noted. Radiocarpal degenerative changes were noted preoperatively in 20 of the 35 wrists (57%).

Complications and Reoperations

In the cohort, there were a total of 12 complications (34%) (Table 2). Complications included 1 pin tract infection, 7 instances of painful/prominent hardware, 1 case of painful heterotopic ossification formation, 1 case of continued DRUJ pain, and 2 cases of ulnar stump instability/pain. Given than the pin tract infection and prominent/painful hardware were deemed “minor” complications, the major complication rate was 11.3%.

Table 2.

Complications and Resulting Treatment Following S-K Procedure.

Complication	Amount	Treatment
Pin tract infection	1	Hardware removal, antibiotics
Painful/prominent hardware	7	Hardware removal
Painful HO	1	HO excision, indomethacin
Continued DRUJ pain	2	RIA with Achilles allograft
Ulnar instability	1	Distal ulna stabilization

Note. HO = heterotopic ossification; S-K = Sauve-Kapandji; DRUJ = distal radioulnar joint; RIA = resection interposition arthroplasty.

The case of pin tract infection resolved with hardware removal and oral antibiotics. All cases of painful or prominent hardware resolved uneventfully with hardware (screw) removal. The case of painful heterotopic ossification resolved with heterotopic ossification excision and indomethacin administration. The case of continued DRUJ pain was revised using resection interposition arthroplasty utilizing an Achilles tendon allograft (Sotereanos procedure). This patient had continued ulnar sided wrist pain localized to the region of the DRUJ. The patient had no clinical ulnar stump instability and based on radiographic assessment, there was no evidence of nonunion. The S-K arthrodesis site was also noted to be united under direct visualization intraoperatively. After a year of failed nonoperative management, the S-K site was osteotomized and the remnant distal ulna removed with an interposition between the radius and ulnar stump using an Achilles tendon allograft. Her pain improved after this. The first patient with ulnar stump instability was treated with a distal ulnar stump stabilization utilizing the brachioradialis. The second patient had ulnar stump pain which was treated with interposition/stabilization of the ulnar stump using GraftJacket (Wright Medical, Memphis, TN) between the radius and ulnar stump. The latter 2 patients had resolution of their symptoms following stabilization.

Discussion

Clinical Outcome

This study demonstrates that the S-K procedure reliably improves VAS pain scores for patients with DRUJ pathology at final follow-up. Mean pain scores showed statistically significant improvements and 64% of patients were pain free after surgery with 91% showing some improvement in pain. This was similar to other studies in the literature that further legitimize the pain relief achieved with the SK procedure.^3,6,10,13,14

Additionally, grip strength demonstrated statistically significant improvements after the S-K procedure. Improvement in grip strength was confirmed in several other studies^11,13,14,18 and is an important functional confirmation of pain relief and DRUJ stability.

The only statistically significant change in range of motion after the S-K procedure was a decrease in wrist flexion. Interestingly, this was not often noted in other studies.^{6,11,13,14,18} The decrease in flexion noted in our study may be due to the significant dorsal capsular plication that is performed to increase stability of the construct. Many other studies have demonstrated increases in supination following the S-K procedure.^3,6,11,13,14 Although this study did demonstrate an increase in supination from 49.8 degrees to 60 degrees, this did not reach statistical significance. This was likely due to the relatively small sample size. Pronation and wrist extension were maintained after the procedure and were not statistically different.

Therefore, when counseling a patient with DRUJ pathology regarding the anticipated clinical outcomes, the patient can expect reliable pain relief, improved grip strength, and maintained range of motion with possible improvement in supination. This would theoretically lead to improved function of the extremity, and this has been reported in multiple prior series.^2,4,6

Radiographic Outcome

Radiographic analysis in this study demonstrated 100% union rate of the arthrodesis site. This is echoed in other studies^4,6,11,13,14 and likely contributes to the overall success of the procedure. Only 1 patient demonstrated progressive ulnar carpal translation postoperatively. This does make logical sense given that 1 advantage of the S-K procedure is that the ulnocarpal ligamentous complex is retained compared to the Darrah which is disrupted. There have been mixed results in the literature when examining ulnar carpal translation after the S-K procedure. Ota et al ¹⁹ analyzed ulnar carpal translation in S-K patients and suggested that decreased radioulnar wrist width may be a contributing factor to ulnar translation. Giberson-Chen et al ⁶ showed statistically significant McMurtry’s translation index when comparing preoperative values versus postoperative values. However, the index was 0.3 preoperatively and 0.2 postoperatively with a standard deviation of 0.1, which makes this of questionable clinical significance. Other studies^7,15 did not show any significant ulnar carpal translation following the S-K procedure. Lastly, our study found that 57% of patients had radiocarpal arthritis at final follow-up. Future studies analyzing the impact of ulnar carpal translation and radiocarpal arthritis on the outcomes of the S-K for DRUJ pathology would be beneficial when counseling patients.

Complication/Reoperation Rate

This study demonstrated a 34% overall complication rate. However, 8 of the 12 complications (66.67%) were relatively minor complications with 7 being prominent hardware and 1 being a pin tract infection that all resolved with hardware removal. The 23% rate of hardware removal was higher than in the 7% cited in Giberson-Chen et al’s ⁶ study in which the authors used headless compression screws. A further direction of study may be to compare the cost-benefit analysis of utilizing headless compression screws versus standard screws with or without K-wires with an expected need for further hardware removal. The 34% overall complication rate was higher than in some studies^6-8,13-15,20 but lower than the highest reported rate (58%), which also utilized standard screws. ⁴

The major complication rate was 11.3%, which is more consistent with the current published literature as above. These included 1 (2.8%) case of painful heterotopic ossification, continued DRUJ pain in 1 (2.8%) patient, and 2 (5.7%) cases of ulnar stump instability/pain. Although uncommon, this continued DRUJ pain was salvaged with ulnar arthrodesis site osteotomy, resection of distal ulnar head, and interposition arthroplasty using an Achilles allograft (Sotereanos procedure). ⁵ The ulnar stump instability cases were resolved with an ulnar stump stabilization utilizing the brachioradialis and 1 interposition/stabilization utilizing GraftJacket.

Study Limitations

The limitations of our study are the retrospective nature of the study design, the heterogeneous population of DRUJ pathologies, and the small cohort of patients. However, the number of patients in this study (35) is relatively large compared to the current S-K literature. Although the mean follow-up of 49.5 months was helpful to translate clinical outcomes to mid- to long-term outcomes, it would be helpful to have 5- and 10-year results. Although there are multiple pathologies addressed in this cohort, this study supports the pragmatic utility of the S-K procedure in treatment of all DRUJ pathologies.

Conclusion

Overall, the S-K procedure remains a viable treatment option for DRUJ dysfunction with results of this study demonstrating excellent pain relief, improved postoperative grip strength, retained wrist pronation, supination and extension, high rate of successful arthrodesis, and low rate of major complications.