Experience with Diagnosis and Management of Distal Radioulnar Joint Instability

Abstract

Objective  The aim of this study is to review our cumulative experience with diagnosis and treatment of distal radioulnar joint (DRUJ) instability and to present our treatment algorithm.

Materials and Methods  Retrospective review identified 112 patients who had 126 episodes of care for DRUJ instability at a single institution over a 21-year period. Those diagnosed acutely or subacutely were treated with immobilization of the wrist and elbow for 6 weeks, while those with chronic instability had anatomic reconstruction of the dorsal and palmar radioulnar ligaments with tendon autograft or an alternative arthroscopic treatment with our thermal annealing technique. Short-term treatment failures and surgical complications were recorded. Nonparametric statistical tests were used to analyze key long-term outcome measures including ulnar wrist pain and DRUJ stability indicated by the dorsopalmar stress test.

Results  At mean 7-year follow-up, eight patients in the acute-injury cohort had statistically significant improvements in wrist pain and DRUJ instability ( p  < 0.001). In both the 22-patient anatomic reconstruction cohort and the 37-patient arthroscopically treated group, there were also statistically significant improvements in wrist pain and DRUJ stability ( p  < 0.001) at mean 9-year follow-up. The majority of patients in all three groups was satisfied with treatment outcome, though some required secondary procedures.

Conclusion  Early clinical diagnosis of DRUJ instability using the dorsopalmar stress test provides an opportunity for effective nonsurgical treatment. For chronic presentation, we recommend our arthroscopic thermal annealing technique for mild or moderate instability and open anatomic reconstruction of the radioulnar ligaments for severe instability.

Level of Evidence  This is a Level IV, therapeutic study.

Distal radioulnar joint (DRUJ) instability is a clinical syndrome of ulnar-sided wrist pain caused by abnormal motion of the ulna with respect to the radius under routine loading conditions of daily activities. Usually, the sequela of wrist trauma, most cases are isolated soft tissue injuries caused by partial or complete disruption of the DRUJ ligamentous stabilizers, though some may result from radius fracture with or without ulna fracture. After the causative wrist trauma, the direction and severity of instability are determined by the extent to which the primary and secondary DRUJ stabilizers are disrupted.

The triangular fibrocartilage complex (TFCC), which includes the marginal dorsal and palmar radioulnar ligaments, the triangular-shaped central articular disk, the palmar ulnocarpal ligaments, and the extensor carpi ulnaris (ECU) subsheath, stabilizes the DRUJ during forearm rotation. Cadaveric studies have shown that the deep fibers of the radioulnar ligaments arising from the well-vascularized ulnar fovea are the primary stabilizers of the DRUJ, whereas the superficial fibers originating from the ulnar styloid base are secondary stabilizers. ^{1 2} Secondary static stabilizers also include the DRUJ capsule, ³ the distal oblique bundle of the interosseous membrane, ^{4 5} and the ulnocarpal ligaments by virtue of their attachments to the palmar radioulnar ligament, ulnar fovea, and styloid. ⁶ Secondary dynamic stabilizers include the ECU tendon and subsheath ⁷ and the pronator quadratus. ⁸ The avascular TFCC articular disk has no influence on DRUJ stability and may be excised with impunity provided that the marginal radioulnar ligaments are not violated. ⁹

The purpose of this study is to present our experience with the diagnosis and management of DRUJ instability. Outcomes of our treatment cohorts have been reported in detail elsewhere. ^{10 11 12} In this study, the goals are to provide the demographic profile and clinical features of our entire patient cohort, to summarize our long-term key outcome measures of wrist pain and DRUJ stability, to determine overall patient satisfaction, and to identify treatment failures, adverse events, and the need for secondary procedures. Our approach to these patients is summarized in a new treatment algorithm providing management guidelines based on the acuity and severity of the instability.

Materials and Methods

This is a retrospective study of patients with DRUJ instability treated from September 1995 to December 2016 by two of us (B.F.H. and H.A.M.), who are fellowship-trained orthopaedic hand surgeons. The research protocol was approved by the University of Kansas School of Medicine Institutional Review Board and all study participants provided informed consent. Patients with wrist pain and instability were identified by searching electronic databases at Advanced Orthopaedic Associates for the International Classification of Diseases codes corresponding to these diagnoses.

Diagnosis

The diagnosis of DRUJ instability was made on clinical grounds, predicated on a positive dorsopalmar stress test ¹³ which replicated the patient's ulnar-sided wrist pain. Increased laxity when dorsal-directed stress was applied to the distal ulna with the forearm pronated indicated incompetence of the deep palmar radioulnar ligament. Conversely, increased laxity on palmar-directed stress with the forearm supinated indicated incompetence of the deep dorsal radioulnar ligament. Mild-to-moderate laxity corresponded to 2 to 4 mm of ulnar translation on the dorsopalmar stress test, whereas laxity ≥5 mm demonstrated severe DRUJ instability. Therefore, this provocation was used to assess not only the direction but also the severity of the instability. The clinical diagnosis was supported by other positive physical findings including ulnar fovea sign, ¹⁴ piano key sign, ¹⁵ and ulnocarpal stress test. ¹⁶ In this study, wrist magnetic resonance imaging was not routinely used to assess TFCC integrity.

Inclusion and Exclusion Criteria

Patients from the screened pool of candidates were included in the study if they were treated for acute or subacute post-traumatic DRUJ instability with 6 weeks of immobilization or if they received surgical treatment for chronic instability. Those included were judged to have clinically significant DRUJ instability on physical examination from presumed complete or near complete TFCC foveal detachment.

Patients who were noncompliant or declined recommended treatment and those who were treated with benign neglect for minimal symptoms were excluded. Among the surgical cohort, patients with prior wrist reconstruction unrelated to the DRUJ or preexisting wrist and/or DRUJ arthrosis and those who underwent nonanatomic DRUJ stabilization were also excluded. The demographics and clinical characteristics of the resulting patient cohort are reported herein. The subgroups analyzed for long-term therapeutic outcomes were determined by the additional exclusion of patients who did not have a minimum 2-year post-treatment follow-up.

Treatment Protocols

Nonsurgical treatment in the form of 6 weeks of immobilization in a single sugar-tong orthosis comprised of 4-inch plaster was offered to all patients with DRUJ instability who presented within 10 weeks of the causative wrist injury. ¹⁰ Those who declined this protocol or were noncompliant with the recommended treatment received symptomatic care.

Since 1998, arthroscopic thermal annealing of the secondary capsuloligamentous DRUJ stabilizers was offered to those presenting with chronic DRUJ instability as an alternative to open surgical treatment. ¹¹ Under 10 to 15 lb (5–7 kg) of vertical wrist traction, radiocarpal inspection with a 2.9 mm 30-degree arthroscope was accomplished through the 3–4 viewing portal. Through the 6R portal, thermal energy was delivered by the Vulcan Micro TAC-S monopolar radiofrequency probe (Smith & Nephew, Inc., Andover, MA) to target tissues, including the superficial dorsal and palmar radioulnar, short radiolunate, ulnolunate, and ulnotriquetral ligaments and the dorsoulnar wrist capsule. Using a smooth paintbrush motion in the axial plane, two to four passes of the electrothermal probe over the stretched palmar ligaments and peripheral TFCC were made until soft tissue contraction and ulnocarpal joint narrowing were observed. Importantly, the wrist was vented through the 6U outflow portal during the application of heat energy to control the fluid temperature and avoid thermal injury to the articular cartilage. Arthroscopy of the DRUJ was not required.

Open anatomic reconstruction of the distal radioulnar ligaments with free tendon graft was offered to all patients with chronic DRUJ instability early in our series and to those who failed thermal annealing or who had severe instability later in the series. Most in this subgroup were reconstructed prior to 2005 by using the Sanders technique. ^{12 17} Thereafter, our preferred method for open reconstruction, particularly for those with severe instability, was the Adams-Berger technique. ^{18 19 20}

All three protocols included immobilizing both the wrist and elbow in neutral forearm rotation for 6 weeks using a single sugar-tong orthosis, as primary treatment following acute or subacute injuries or as a key feature of postoperative care after arthroscopic or open surgery. Thereafter, patients were managed in a removable short-arm orthosis for 2 to 4 weeks and began physician-directed wrist extension and flexion while avoiding radial or ulnar deviation and forearm rotation. Heavy lifting and sports activity were restricted for 6 months. No formal hand therapy was required.

Outcome Assessments

Demographic and clinical data were abstracted from the medical records of the study cohort and managed in an electronic database system. The key outcome parameters were wrist pain, wrist range of motion, and DRUJ stability as determined by the dorsopalmar stress test. ¹³ Short-term outcomes were assessed by changes in wrist pain and DRUJ instability found in the medical record and by the need for a secondary treatment. Treatment failure was defined as no meaningful clinical improvement or worsening of symptoms 3 months after immobilization for acute or subacute instability or 6 months after surgical intervention for chronic instability. Postoperative complications were also documented.

Longer-term outcomes were derived from study of the patient-volunteers who enrolled in our research protocol. Minimum 2-year post-treatment and recalled pretreatment wrist pain were quantified on a 0 to 10 visual analog scale (VAS). Wrist range of motion was measured with a handheld goniometer and grip strength was determined with a Jamar dynamometer (Model 0030J4, Therapeutic Equipment Corp., Clifton, NJ). Stability of the DRUJ was assessed by one of us (B.F.H.) using the dorsopalmar stress test. The modified Mayo Wrist Score ²¹ was used as an outcome measure with scores in the 91 to 100 range rated as excellent, 80 to 90 as good, 65 to 79 as fair, and 0 to 64 as poor.

Statistical Analyses

Standard descriptive statistics included measures of central tendency (mean, median), variance (standard deviation, range), and occurrence frequencies. Nonparametric statistical tests were applied to compare pretreatment and post-treatment measures. The sign exact test, Wilcoxon's signed-ranks exact test, and the McNemar Chi-square exact test were used to analyze the matched-pairs ordinal data for wrist pain, wrist range of motion, and DRUJ instability. For all analyses, we selected p <0.05 for a two-tailed test as the level of statistical significance.

Results

Our comprehensive review of DRUJ instability over a 21-year period revealed that 112 distinct patients had 126 episodes of care distributed among 3 treatment protocols as shown in Fig. 1 . Only 19 patients (17%) presented acutely or subacutely and received nonsurgical treatment. One of those failed immobilization and required secondary thermal annealing, while another with bilateral instability had nonoperative treatment on one wrist and thermal stabilization on the opposite side.

Fig. 1.

Distribution of patients and cases among the three treatment protocols. In total, 19 patients were treated nonsurgically, 65 patients (67 wrists) had arthroscopic thermal annealing, and 38 patients (40 wrists) had anatomic reconstruction of the distal radioulnar joint. There were 112 distinct patients and 126 episodes of care.

Of those treated surgically for chronic instability, 65 patients (67 wrists) had arthroscopic thermal shrinkage, one having treatment on both wrists at separate times and another having revision treatment after wrist reinjury. Eight patients who had arthroscopic thermal treatment required later open anatomic reconstruction. Thirty-eight patients (40 wrists) had anatomic reconstruction of the distal radioulnar ligaments with two requiring revision procedures.

The demographic and clinical findings of those studied are shown in Table 1 . Most patients were women and some had underlying generalized ligamentous laxity. The two most common mechanisms of injury were fall on the outstretched hand and forced wrist rotation. Nearly, all patients had ulnar-sided wrist pain which was reproduced by the dorsopalmar stress test and some had painful popping or subluxation of the DRUJ with wrist loading. Wrist pain was also elicited with ulnar foveal, ¹⁴ piano key, ¹⁵ or ulnocarpal stress ¹⁶ provocations in the majority for whom those tests were recorded.

Table 1. Demographics and clinical features.

Characteristics	Values
Premorbid injury a	103 (92%)
Age at injury (y) b	31 (14), 30 (11–77)
Age at presentation (y) b	33 (12), 32 (12–77)
Male, female a	33 (29.5%), 79 (70.5%)
Hand dominance, right a	99 (88%)
Symptomatic side, right a	67 (60%)
Mechanism of injury a
Fall on outstretched hand	42 (37.5%)
Rotational (lifting or twisting)	31 (27.7%)
Blunt trauma	13 (11.6%)
Repetitive trauma	10 (8.9%)
Distal radius fracture	7 (6.3%)
No known injury	9 (8.0%)
Workers' compensation claim	48 of 108 (44%)
Ulnar-sided wrist symptoms a
Wrist pain	110 of 111 (99%)
Wrist painful popping	22 of 111 (20%)
DRUJ instability provocative signs a
Dorsopalmar stress test	109 of 111 (98%)
Ulnocarpal stress test	57 of 93 (61%)
Piano key sign	39 of 73 (53%)
Ulnar fovea sign	40 of 76 (53%)

Abbreviation: DRUJ, distal radioulnar joint.

^aData shown are number of patients (% of total).

^bData shown are mean (standard deviation), median (range) in 112 patients.

The patient and case distribution, time from injury to treatment, and length of long-term follow-up are indicated for each treatment cohort in Table 2 . Ten patients received treatment under two separate protocols. Of the 112 patients treated for DRUJ instability, 65 were enrolled in our study, 10 declined to participate, 34 were lost to follow-up, 2 required DRUJ arthroplasty for arthrosis, and 1 was deceased.

Table 2. Patient/case distribution, time to treatment, and length of follow-up by treatment protocol.

Treatment protocol	Entire cohort (patients/cases)	Long-term cohort (pts/cases)	Time to treatment	Follow-up duration
Nonsurgical/Immobilization	19/19	8/8
Acute (<6 wk postinjury) 10	16/16	8/8	15 (11, 5–36) d	7 (3, 3–12) y
Subacute (6–13 wk postinjury)	3/3	0/0
Arthroscopically treated	65/67	37/37	13 (11, 3–53) mo	9 (5, 2–19) y
Thermal annealing only 11	60/62	33/33
Thermal annealing w/TFCC repair	5/5	4/4
Open DRUJ reconstruction	38/40	22/22	16 (3–189) mo	9 (5, 2–21) y
Sanders technique 12	30/31	19/19
Adams-Berger technique	8/9	3/3

Abbreviations: DRUJ, distal radioulnar joint; TFCC, triangular fibrocartilage complex.

Note: Data shown are patient/case counts and mean (standard deviation, range) or median (range) for time values. There are 112 distinct patients. Two patients appear in both the nonsurgical and arthroscopically treated groups and eight are counted in both the arthroscopically treated and open reconstruction cohorts.

Nonsurgical Treatment Outcomes

Eight patients who were immobilized within 6 weeks of wrist trauma were evaluated at a mean 7 years postinjury ( Table 3 ). This acute-injury cohort had statistically significant improvement in wrist pain on VAS. All had a negative dorsopalmar stress test, indicating statistically significant improvement in DRUJ stability. All were satisfied with the clinical outcome. The modified Mayo Wrist scores were stratified as 3 excellent, 5 good, 0 fair, and 0 poor.

Table 3. Long-term clinical outcome measures of nonsurgically treated cohort ( n  = 8) .

Symptom or physical sign	Number of patients	Pretreatment values	Post-treatment values	p -Value
Ulnar-sided wrist pain severity (VAS rating) a	6	8 (6–9)	0 (0–1)	0.031
DRUJ instability on dorsopalmar stress test b	8	8 wrists +	0 wrists +	0.008

Abbreviations: DRUJ, distal radioulnar joint; VAS, visual analog scale.

Note: Bold values indicate a significant difference for a two-tailed test ( p  < 0.05). Data shown are median (range) for pain or patient counts for dorsopalmar stress test.

^aWilcoxon signed-ranks exact test.

^bMcNemar Chi-square exact test.

When the short-term outcomes were included, 11 of 16 patients in this group were overall improved, leading to the recommendation for immobilization in those with acute post-traumatic DRUJ instability. ¹⁰ In the subacute group at short-term follow-up, one patient had symptom resolution, the second had partial improvement, and the third failed to improve.

Arthroscopic Thermal Annealing Outcomes

At an average of 9 years after surgery, the 37-patient cohort treated with our thermal annealing technique ¹¹ had statistically significant improvement in wrist pain on VAS and DRUJ stability to dorsal stress with the forearm pronated and palmar stress in supination ( Table 4 ). Wrist range of motion was not significantly changed. Outcomes based on the modified Mayo Wrist Score were stratified as 5 excellent, 15 good, 10 fair, and 1 poor. In total, 34 of 37 patients were satisfied with the outcome and 35 of 37 stated that they would recommend the procedure.

Table 4. Long-term clinical outcome measures of arthroscopically treated cohort ( n  = 37) .

Symptom or physical sign	Number of patients	Preoperative values	Postoperative values	p -Value
Ulnar-sided wrist pain severity (VAS rating) a	37	8 (2–10)	0 (0–7)	<0.001
Wrist range of motion (degrees)
Dorsiflexion b	19	70 (55–85)	68 (54–82)	0.371
Palmar flexion b	19	73 (45–90)	68 (47–86)	0.089
DRUJ instability on dorsopalmar stress test
Dorsal stress w/forearm pronated c	29	26 wrists +	5 wrists +	<0.001
Palmar stress w/forearm supinated c	27	22 wrists +	3 wrists +	<0.001

Abbreviations: DRUJ, distal radioulnar joint; VAS, visual analog scale.

Note: Bold values indicate a significant difference for a two-tailed test ( p  < 0.05). Data shown are median (range) for pain and wrist range of motion or patient counts for dorsopalmar stress test.

^aSign exact test.

^bWilcoxon signed-ranks exact test.

^cMcNemar Chi-square exact test.

Based on physical and arthroscopy findings, all patients were judged to have partial or complete disruption of the TFCC foveal attachment with poor healing potential (Aztei-Luchetti ²² Class 4 lesions). Four patients with marginal TFCC tears in addition to foveal detachment underwent repair of superficial dorsal radioulnar ligament to the capsule by arthroscopic suture technique to enhance thermal annealing efficacy. In 75% of cases, there were partial tears of the ulnolunate and ulnotriquetral ligaments, which were targeted during the thermal shrinkage.

Anatomic Reconstruction Outcomes

At mean 9-year postoperative assessment of 22 patients, the DRUJ was stable on dorsopalmar stress test in all but one patient and ulnar-sided wrist pain was also significantly improved ( Table 5 ). The Sanders technique ^{12 17} was used to reconstruct 19 wrists and the Adams-Berger method ^{18 19 20} was employed in three cases. Wrist extension and flexion were not significantly changed. Outcomes based on the modified Mayo Wrist Score were rated as 3 excellent, 13 good, 5 fair, and 1 poor. In total, 19 of 21 patients were satisfied with the result and 20 of 21 would recommend the operation.

Table 5. Long-term clinical outcome measures of open reconstruction cohort ( n  = 22) .

Symptom or physical sign	Number of patients	Preoperative values	Postoperative values	p -Value
Ulnar-sided wrist pain severity (VAS rating) a	19	8 (4–10)	1 (0–5)	<0.001
Wrist range of motion (degrees)
Dorsiflexion b	13	65 (55–80)	65 (50–78)	0.412
Palmar flexion b	13	75 (38–82)	67 (47–76)	0.132
DRUJ instability on dorsopalmar stress test
Dorsal stress w/forearm pronated c	22	18 wrists +	1 wrist +	<0.001
Palmar stress w/forearm supinated c	22	19 wrists +	1 wrist +	<0.001

Abbreviations: DRUJ, distal radioulnar joint; VAS, visual analog scale.

Note: Bold values indicate a significant difference for a two-tailed test ( p  < 0.05). Data shown are median (range) for pain and wrist range of motion or patient counts for dorsopalmar stress test.

^aSign exact test.

^bWilcoxon signed-ranks exact test.

^cMcNemar Chi-square exact test.

Complications

Major adverse events, including treatment failures and wrist reinjuries, are summarized by treatment cohort in Table 6 . Two patients failed nonsurgical treatment, one in the acute group and another in the subacute group. The acute-injury failure improved with arthroscopic thermal annealing, while the subacute-injury failure declined further treatment. There were 12 major adverse events among the 67 wrists treated with the arthroscopic thermal technique for an 18% complication rate. In this cohort, no adverse effects were related to the application of thermal energy in the wrist. In the open reconstruction cohort, there were eight major adverse events in 40 wrists for a 20% complication rate. Most of those who incurred such a surgical complication achieved a satisfactory outcome with a secondary procedure.

Table 6. Major adverse events, treatment failures, and wrist reinjuries ( n  = 126) .

Cohort/Adverse event	Secondary procedure	Outcome
Nonsurgical/immobilization ( n  = 19)
Acute injury cohort, 1 of 16 failed	Arthroscopic thermal annealing	Improved
Subacute injury cohort, 1 of 3 failed	Declined further treatment	Unchanged
Arthroscopic thermal annealing ( n  = 67)
Procedure failure (9)	Adams-Berger reconstruction (3)	3 of 3 improved
	Sanders reconstruction (3)	2 of 3 improved
	Unknown procedure done elsewhere (1)	Improved
	Declined further treatment (2)	Unchanged
Wrist reinjury by fall mechanism (2)	Revision thermal annealing by request	Improved
	Adams-Berger reconstruction	Improved
Ulnocarpal abutment syndrome (1)	Distal ulna open wafer shortening	Improved
Open anatomic reconstruction ( n  = 40)
Sanders failed from DRUJ arthrosis (2)	HIA	Improved
	HIA (failed) and then ulnar head arthroplasty	Improved
Sanders graft ruptured by fall reinjury (1)	Revision Sanders failed from second fall reinjury	No further treatment
Sanders graft ruptured during therapy (1)	Declined further treatment	Unchanged
Adams-Berger graft ruptured w/lifting (1)	Revision Adams-Berger w/allograft tendon	Improved
Superficial radial dysesthesia (1)	Superficial radial nerve decompression	Improved
Extensor tenosynovitis, suture granuloma (1)	Extensor digiti minimi tenosynovectomy	Improved

Abbreviations: DRUJ, distal radioulnar joint; HIA, hemiresection interposition arthroplasty.

Discussion

Our study demonstrated that patients with acute post-traumatic DRUJ instability may improve with prompt immobilization and activity modification and that those with chronic instability may be treated effectively with arthroscopic thermal shrinkage of the secondary DRUJ stabilizers or with open anatomic reconstruction of the radioulnar ligaments. At long-term follow-up, statistically significant improvements in wrist pain and DRUJ stability were observed in all three treatment cohorts. Our preferred treatment algorithm based on this cumulative experience is shown in Fig. 2 .

Fig. 2.

Treatment algorithm for post-traumatic DRUJ instability as a function of injury acuity and degree of instability based on the dorsopalmar stress test. DRUJ, distal radioulnar joint; MRA, magnetic resonance arthrography; TFCC, triangular fibrocartilage complex.

Patients presenting within 6 weeks of the causative wrist trauma are immobilized in a single sugar-tong orthosis continuously for 6 weeks with the expectation that about two-thirds will heal the TFCC tear and not require surgical treatment. Since similar favorable outcomes from conservative treatment were reported in 45 of 72 patients (63%) with documented TFCC tears but without DRUJ instability, ²³ early nonsurgical treatment for these tears may be efficacious regardless of instability. Surgeons should expect that some patients may not tolerate above-elbow immobilization and others may not comply with activity restrictions. In addition, for those presenting with DRUJ instability more than 6 weeks postinjury, nonoperative treatment may not be worthwhile.

When patients present subacutely between 6 weeks and 6 months following trauma or have persistent symptoms after immobilization, we now recommend magnetic resonance arthrography to elucidate the TFCC pathoanatomy and to assess DRUJ subluxation on the axial images. ²⁴ Wrist arthroscopy is indicated to classify the TFCC tear ^{22 25} and to determine if the lesion is amenable to repair. Some surgeons may choose to re-anchor the deep fibers of the radioulnar ligaments to the ulnar fovea by arthroscopic or open technique so long as the soft tissue is well vascularized and will permit suture purchase. However, owing to uncertainty regarding TFCC reparability in this scenario, we prefer arthroscopic thermal shrinkage of the secondary DRUJ stabilizers, since the technique is simple and effective, particularly for mild to moderate instability, and does not preclude secondary open anatomic reconstruction in the event of an unsatisfactory outcome.

With chronic presentation 3 months or more post-trauma, the examiner is usually better able to assess the direction and severity of the DRUJ laxity with the dorsopalmar stress test. Mild to moderate (2–4 mm) laxity to dorsal-directed stress with the forearm pronated and/or to palmar-directed stress with the forearm supinated is treated with our thermal annealing technique with or without arthroscopic capsular repair of a peripheral TFCC tear. Severe (≥5 mm) laxity or persistent symptoms 6 months after thermal annealing are indications for open anatomic reconstruction with the Adams-Berger technique, ^{18 19 20} unless retained hardware interferes with establishing the required bone tunnel in the radius in which case the Sanders technique is employed. ^{12 17} Recurrent DRUJ instability after either open method is addressed with a revision Adams-Berger reconstruction.

Atzei-Luchetti ²² Class 2 or 3 TFCC disruptions may not heal following transosseous foveal repair in all cases, resulting in persistent DRUJ instability and suggesting that the tear may actually have been a Class 4 lesion. Anderson et al ²⁶ found that 8 of 39 patients (21%) treated with open TFCC foveal reattachment failed within 2 years, leading the authors to conclude that TFCC repair alone may not adequately address instability. Nakamura et al ²⁷ reported that 7 of 24 patients (29%) in their series had moderate-to-severe postoperative DRUJ instability with the failures occurring in cases done 7 months or more postinjury. However, later studies from Italy ^{28 29} showed proportionally fewer cases of residual instability (∼8–10%) perhaps because the surgical technique incorporated a two-strand suture anchor at the ulnar fovea, permitting a more secure repair of both dorsal and palmar radioulnar ligaments across a larger repair footprint at the fovea. Recent study of 80 one-anchor, two-suture TFCC foveal repairs demonstrated excellent 2-year outcomes, even in the subgroup done more than a year post-trauma and only two patients in this series had residual instability. ³⁰

Owing to concerns about suboptimal outcomes from TFCC repairs in our practice, patients in this study were offered arthroscopic thermal annealing of the secondary DRUJ stabilizers for chronic instability, regardless of severity, as an alternative to open treatment. ¹¹ Targeting the superficial radioulnar and ulnocarpal ligaments as well as the dorsoulnar wrist capsule with heat energy using a radiofrequency probe produces contraction of those structures and observable narrowing of the ulnocarpal joint. Postoperative immobilization permits soft tissue healing in the contracted position, thereby increasing tension in the secondary DRUJ stabilizers which, though stretched or partially torn, remain somewhat in continuity. Increased tension in the ulnocarpal ligaments is similar to that observed in an ulnar shortening osteotomy, ³¹ and the effect on the capsule is equivalent to an open capsular imbrication, ³² both of which indirectly stabilize the DRUJ. In addition to these mechanical effects, the efficacy of the thermal technique may be related to partial wrist denervation induced by the heat energy. ³³

Although 9 of 67 patients (13%) in the thermal cohort were treatment failures, most of these had moderately severe instability, suggesting that limiting the indications for thermal shrinkage to those with mild-to-moderate instability may reduce the number of treatment failures. On a percentage basis, revision surgery required for the treatment failure in this subgroup compares favorably with revisions mandated after failed TFCC repairs in other series. ^{26 27 28 29} When treatment failure occurs in patients with ulnar positive variance ≥2 mm, concomitant ulnar shortening should be strongly considered during revision DRUJ stabilization.

The limitations of our retrospective case series include an incomplete medical database, lack of a control group for comparison, patient recall bias regarding preoperative pain severity, and investigator detection bias during outcome examinations. On the positive side, this study represents the largest series of patients with DRUJ instability and provides the longest duration follow-up in the literature.

Conclusion

DRUJ instability is an infrequent and under-recognized cause of post-traumatic ulnar wrist pain. Early clinical diagnosis by means of the dorsopalmar stress test provides the opportunity for continuous above-elbow immobilization which is successful in about two-thirds of cases. However, delayed diagnosis for 6 weeks or more post-trauma usually mandates surgical treatment. At long-term follow-up, our study found statistically significant improvements in wrist pain and DRUJ stability with nonsurgical treatment following acute injuries and with our arthroscopic thermal annealing technique or open anatomic reconstruction methods for chronic injuries. These favorable outcomes confirm the effectiveness of our treatment protocols and indicate that our treatment algorithm may be a useful management tool for these patients.

Funding Statement

Funding Partial funding for use of Research Electronic Data Capture (REDCap) was by Clinical and Translational Science Award UL1TR002366 from the National Center for Advancing Translational Sciences at the National Institutes of Health.