Distal Radioulnar Joint Stability Research Articles

Operative Stabilization of Distal Radius Fractures Presenting With Ulnar Head Subluxation/Dislocation Addresses Distal Radioulnar Joint Instability Without Further Stabilization Procedures.

To determine the prevalence of ulnar head subluxation/dislocation in distal radius fracture and to discuss management, surgical outcomes, and relevant anatomy. Urban tertiary care hospital. Two hundred seventy-one patients with displaced distal radius fractures undergoing surgical management were reviewed to determine the incidence of ulnar head subluxation or dislocation using the Mino criteria defined by Mino et al. Postoperative computed tomography and radiographs were assessed for sigmoid notch and distal radioulnar joint (DRUJ) reduction and fracture healing. Range of motion, functional limitation, and pain were documented at final outcome. Of the 271 cases, there were 8 cases of prereduction DRUJ subluxation/dislocation, including 2 frank dislocations and 6 subluxations (2.95%). All were treated with open reduction and internal fixation (ORIF) of the distal radius with a volar locked plate. In addition, 1 patient underwent ORIF of an associated distal ulnar shaft fracture and another, who had a grade 1 open fracture over the distal ulna, underwent open TFCC repair. The remaining 6 patients had closed reduction of the DRUJ without further stabilizing procedures. All had stable DRUJ joints following ORIF, both intra-operatively and at final follow-up. All ulnar heads were located within the DRUJ on post-op computed tomography; using the more sensitive radioulnar ratio there was residual ulnar head subluxation in 5/8 patients. Range of motion and functional outcome were excellent at an average of 133 weeks postoperatively. The DRUJ was stable at long-term follow-up in all patients. Ulnar head subluxation/dislocation is an uncommon injury in the setting of distal radius fracture. When present, it can usually be treated effectively with operative stabilization of the distal radius fracture without further stabilizing procedures. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Stabilization of the Distal Radioulnar Joint with or without Triangular Fibrocartilage Complex Tear by an External Wrist Band Brace: A Cadaveric Study.

The purpose of this study was to investigate whether a watch-shaped external wrist band brace improves distal radioulnar joint (DRUJ) stability. Seven fresh cadaveric arms were used. Using a customized testing system, volar and dorsal translation forces were applied to the radius externally while the ulna was fixed. The test was performed with the forearm in neutral, 60° pronated, and 60° supinated positions, once without the brace and once with the brace applied. In each condition, the amount of translation was measured. Then, the triangular fibrocartilage complex (TFCC) was detached from the ulnar styloid process and the fovea ulnaris, and the same tests were performed again. Detachment of the TFCC significantly increased volar and dorsal translations in all forearm rotations compared to the intact condition (p < 0.05), except for the pronated dorsal translation of the radius (p = 0.091). Brace application significantly reduced volar and dorsal translations in all forearm rotations both in intact specimens and in TFCC-detached specimens (p < 0.05), except for pronated volar and dorsal translations in TFCC-detached specimens (p = 0.101 and p = 0.131, respectively). With the brace applied, the TFCC-detached specimens showed no significant difference in volar or dorsal translation in all forearm rotations compared to the intact specimens (p > 0.05). The external wrist band brace improved DRUJ stability in both normal and TFCC-torn wrists and reduced the DRUJ instability caused by TFCC tear to a near-normal level.

Open Foveal Repair of the Triangular Fibrocartilage Complex Tears Associated with Symptomatic Ulnar Styloid Non-union.

Background: Symptomatic ulnar styloid non-union can be treated by excision of the ulnar styloid fragment. For combined triangular fibrocartilage complex (TFCC) tears, several repair techniques such as arthroscopic repair, open repair to the fracture site or reconstruction using a tendon graft have been introduced. This study reports the technique and outcomes of open foveal repair of the TFCC with excision of the ulnar styloid fragment in patients with symptomatic ulnar styloid non-union and distal radioulnar joint (DRUJ) instability. Methods: Consecutive patients with symptomatic ulnar styloid non-union with TFCC tears and DRUJ instability who underwent excision of the ulnar styloid fragment and open foveal repair of the TFCC were retrospectively reviewed. After excising the ulnar styloid fragment, a capsular window was created between the triquetrum and TFCC, followed by attaching the TFCC to the fovea using three sutures through a bone tunnel from the ulnar cortex to the fovea. Additional ulnar shortening osteotomies were performed in patients with positive ulnar variance and ulnar impaction test. The outcomes were evaluated in terms of DRUJ stability and the Quick Disabilities of the Arm, Shoulder and Hand (DASH) scores. Results: In total, 21 patients with a mean age of 40 were enrolled in the study. All patients demonstrated DRUJ stability at a mean follow-up duration of 14 months. The mean Quick DASH score significantly improved from 18.9 ± 11.7 to 2.5 ± 4.1 (p < 0.05). Eleven patients underwent combined ulnar shortening osteotomies, and no difference in the Quick DASH score was found between patients who underwent ulnar shortening osteotomy and those who did not. Conclusions: This study demonstrates that open foveal repair of the TFCC with ulnar styloid fragment excision is an effective strategy to surgically treat patients with symptomatic ulnar styloid non-union with TFCC tear and DRUJ instability. Level of Evidence: Level III (Therapeutic).

Mid- to long-term functional results after Bowers' hemiresection interposition arthroplasty of the distal radio-ulnar joint

Bowers' hemiresection interposition arthroplasty of the distal radio-ulnar joint has been performed for decades, mainly for the treatment of osteoarthritis of the distal radio-ulnar joint. However, long-term test results are sparse. Evaluation of a homogeneous patient population following a mid- to long-term postoperative follow-up interval after hemiresection interposition arthroplasty. Twenty-five patients were evaluated 77.2 (±34.6) months after surgical therapy with regard to range of motion, grip strength and pain level. The subjective and objective scores DASH (Disabilities of Arm, Shoulder, and Hand) and MMWS (modified Mayo Wrist Score) were collected. Wrist mobility is not worse than 10.4° in relation to all directions of wrist movement compared with the healthy opposite side. Coarse grip strength is reduced by an average of 5.8 kg compared with the opposite side. The pain level decreased on average from 8.2 preoperatively to 1.8 postoperatively. Postoperatively, 22 patients (88 %) had a stable distal radio-ulnar joint. At the time of follow-up DASH averaged 26.7 (±21.4) and the MMWS averaged 78 (±15.7). Hemiresection interposition arthroplasty is areliable and safe surgical technique with good subjective and functional outcomes in the mid- to long-term.

FUNCTIONAL OUTCOME OF TREATING GIANT CELL TUMOUR OF DISTAL ULNA WITH WIDE EXCISION AND WRIST RECONSTRUCTION WITH ILIAC CREST BONE GRAFT

Background: Giant cell tumours of bone are aggressive, potentially malignant lesions. Juxta articular giant cell tumours of lower end ulna are rare and present a special problem of reconstruction after tumour excision. Out of the various treatment procedures described, use of iliac crest bone graft for wrist reconstruction after wide resection of the tumour is done with satisfactory functional results. Methods: Six patients with a mean age of 21 years, with proven giant cell tumours of distal end ulna were treated with wide excision and reconstruction with tricortical iliac crest graft. Wrist reconstruction and xation of graft was done with 4.o mm cancellous screws and K wire. The distal stump of resected ulna was stabilised by Extensor carpi ulnaris tendon slip. Results: The follow up ranges from 3 years (mean 30 months). At last, follow up, the mean MSTS was 71 and mean grip strength improved from 28 kg. to 37 kg. with an attainment of mean grip strength of 80% as compared with the contra lateral hand and a fair range of movements. There was no incidence of recurrence, any malignant transformation, loss of function, neurovascular decit. There were no cases with any infection or wound dehiscence. Conclusions: Distal ulna can be replaced with xation iliac crest bone graft provided it is attached to the triangular bro cartilage and ulnar collateral ligament which results in restoration of the anatomy and stability of distal radioulnar joint respectively. The distal resected stump of the ulna should be stabilised with ECU by tenodesis to prevent impingement which gave a good result in our cases.

Essex-Lopresti Lesions and Longitudinal Radioulnar Instability: A Narrative Review.

An Essex-Lopresti injury (ELI) is classically described as a radial head fracture with a concomitant interosseous ligament complex (IOC) injury. However, multiple injury patterns may be present, and an interosseous membrane (IOM) injury should be evaluated for in any axial load injury through the forearm. ELI may result in longitudinal radioulnar instability (LRUI). Diagnosis of an IOC injury can be difficult. Evaluation begins with standard wrist and elbow radiographs and is supplemented with radiographs and intraoperative maneuvers to assess for proximal radial migration. Magnetic resonance imaging and ultrasonography may be useful in the acute setting, although indications and the clinical importance of the findings remain unclear. Surgical management of an acute ELI is focused on restoration of radial length and temporary distal radioulnar joint (DRUJ) stabilization. Radial head excision in the acute setting should be approached with caution because proximal migration may not be present acutely but may develop over time. The indication for acute IOM repair and reconstruction remains unclear. Surgical management of a chronic ELI is focused on restoration of radial length, wrist leveling, and treatment of degenerative changes (either at the radiocapitellar joint or the DRUJ). Reconstruction of the central band can restore forearm load transfer and produce favorable functional outcomes, but its indications continue to be debated.

Radius distraction during volar plating of distal radius fractures may improve distal radioulnar joint stability at minimum 3-year follow-up: a retrospective case series study

BackgroundThe surgical technique of radius distraction for stabilization of distal radioulnar joint (DRUJ) if intraoperative DRUJ instability was found after the fixation of distal radius fracture has been previously described, but this surgical technique lacks clinical and radiographic effect in minimal 3 years follow-up. We therefore evaluated the clinical outcome and radiographic results of radius distraction in minimal 3 years follow-up as long-term evaluation.MethodsWe reviewed the case series of distal radius fracture with concomitant DRUJ instability receiving radius distraction from the senior author over a 5-year period (January 1st, 2013, to June 30th, 2017) retrospectively. Radius distraction during volar plating was performed by moving the volar plate distally via compression screw loosening/fastening to achieve firm endpoint on the dorsopalmar stress test. The evaluations of radiographic, including bone union time and ulnar variance, and clinical outcomes, including grading of DRUJ instability, NRS of wrist pain, DASH score, MMWS score, and range of motion of operated wrist at final follow-up, were performed at clinic as minimum 3-year follow-up; a total 34 patients had been evaluated.ResultsAt minimal post-operative 36 months follow-up, all cases demonstrated acceptable wrist range of motion with stable DRUJs, low NRS of wrist pain (0.6, SD 0.7), and satisfactory DASH score (mean 9.1, SD 6.2) and MMWS score (mean 87, SD 10). There were no cases suffering from nonunion of distal radius. The mean ulnar variance of injured wrist and uninjured wrist were -1.2 mm and 0.2 mm, respectively (SD 1.0 and 0.6) with significant statistical difference.ConclusionsRadius distraction during volar fixation of distal radius fracture should be considered if DRUJ instability was found by the dorsopalmar stress test intraoperatively, and the long-term DRUJ stability could be achieved by maintenance of normal-to-negative ulnar variance, with decreased wrist pain and satisfactory function outcome.Level of EvidenceTherapeutic Level IV

Midterm Results of Arthroscopy-Assisted “Tent Form” Triangular Fibrocartilage Complex Repair With Dorsal Distal Radioulnar Joint Capsule Imbrication for Posttraumatic Chronic Distal Radioulnar Joint Instability

To evaluate the outcomes of "tent form" triangular fibrocartilage complex (TFCC) repair combined with dorsal distal radioulnar joint (DRUJ) capsule imbrication for posttraumatic chronic DRUJ instability. All patients treated with arthroscopic "tent form" TFCC repair and DRUJ capsule imbrication from 2016 to 2019 were retrospectively reviewed. The inclusion criteria were symptomatic chronic DRUJ instability for >6 months and dorsal DRUJ subluxation on magnetic resonance imaging. The Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, grip strength, Modified Mayo Wrist Score, range of motion, and distal radioulnar joint stability were assessed for a minimum of 2 years postoperatively. Thirty-eight patients were included in the final analysis. The average follow-up duration was 35.6 months (range, 24-48 months). The 24-month postoperative grip strengths and 3-dimensional motions of wrist were not significantly different from that of the nonoperated wrist. Compared with their preoperative status, Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, and Modified Mayo Wrist Score indicated the significant improvement with P values of .001, .001, and .002, respectively. In chronic DRUJ instability with a loosening dorsal capsule, "tent form" TFCC transcapsular repair combined with DRUJ capsule imbrication restored the integrity of TFCC and dorsal DRUJ capsule and achieved a promising outcome. We recommend this procedure as an option of treatment for patients with posttraumatic chronic DRUJ instability. IV, case series.

Anatomical repair of Atzei-EWAS type 2 triangular fibrocartilage complex injury under wrist arthroscopy

To explore the effectiveness of anatomical repair of Atzei-EWAS type 2 triangular fibrocartilage complex (TFCC) injury under wrist arthroscopy. Between March 2018 and March 2020, 16 patients with Atzei-EWAS type 2 TFCC injury were admitted, and the TFCCs were anatomically repaired with a three-dimensional suture with a thread anchor under wrist arthroscopy. There were 10 males and 6 females with an average of 40.2 years (range, 22-54 years). The disease duration ranged from 2 to 9 months (mean, 6.4 months). Preoperative grip strength of the affected limb was (20.06±3.38) kg, wrist range of motion in flexion and extension was (117.19±7.74)°, radial-ulnar deviation was (31.25±5.32)°, forearm rotation range of motion was (137.19±14.83)°, visual analogue scale (VAS) score was 5.6±1.2. At last follow-up, the effectiveness was evaluated by the grip strength of the affected limb, the range of motion of the wrist joint, the VAS score, and the modified Mayo wrist score. All incisions healed by first intention. One case had paralysis of the dorsal branch of the ulnar nerve after operation, and no other complications occurred in other cases. All patients were followed up 12-18 months (mean, 14.5 months). The distal radioulnar joint stability of all patients recovered. At last follow-up, the grip strength of the affected limb was (24.88±3.26) kg, the range of motion in flexion and extension was (146.59±6.49)°, radial-ulnar deviation was (39.38±6.55)°, and forearm rotation range of motion was (152.50±11.55)°, which were significantly higher than those before operation ( P<0.05); the VAS score was 0.9±0.8, which was significantly lower than that before operation ( t=21.029, P=0.000). The modified Mayo wrist score was rated as excellent in 10 cases, good in 5 cases, and fair in 1 case. The excellent and good rate was 93.8%. MRI results showed that TFCC healed in all cases. For Atzei-EWAS type 2 TFCC injury, anatomical repair under wrist arthroscopy can restore the anatomical structure of TFCC, effectively relieve wrist pain, improve function, and obtain good effectiveness.

The reliability of clinical assessment of distal radioulnar joint instability.

Accurate assessment of distal radioulnar joint (DRUJ) stability is increasingly recognized as an important part of clinical examination of the wrist. The ability of 30 specialist UK hand surgeons to clinically determine the stability of four volunteers' wrists was assessed. Volunteers' wrist stability had previously been confirmed with a validated measurement rig. Use of the wrist ballottement test as the primary examination technique yielded a positive predictive value of 81%, a negative predictive value of 55%, a specificity of 94% and a sensitivity of only 24%, for the detection of DRUJ instability. No correlation between background speciality (orthopaedic versus plastic surgery), nor years of clinical experience was found. Clinical assessment of DRUJ instability among experienced clinicians appears unreliable and instability is typically under recognized. Previous research to date using this clinical assessment method as a parameter of success is therefore brought into question.Level of evidence: IV.

Triangular Fibrocartilage Complex Repair/Reconstruction.

The triangular fibrocartilage complex (TFCC) is an intricate structure that plays an important role in providing distal radioulnar joint stability and load transmission at the ulnar wrist. Understanding this structure is critical for creating treatment plans based on patient history, physical examination, and imaging. Arthroscopic, arthroscopic-assisted, and open surgical treatment options exist for tears meeting distinct surgical criteria that are discussed in this article. Although long-term comparative outcomes studies are limited, long-term retrospective outcome studies of TFCC repair and reconstructive techniques demonstrate improvement in pain, stability, range of motion, and disability.

Distal radius fracture with concomitant ulnar styloid fracture: does distal radioulnar joint stability depend on the location of the ulnar styloid fracture?

Studies are conflicting regarding the relationship between ulnar styloid fracture (USF) location and distal radioulnar joint (DRUJ) instability in patients with distal radius fracture (DRF) and concomitant USF. The objective of this study was to determine the association of USF location with TFCC foveal tear and factors associated with DRUJ instability in patients with both DRF and USF. Fifty-four patients with both DRF and USF who had wrist MRI examination before surgery were analyzed. USF location (tip or base) and TFCC foveal insertion status (intact, partial tear, or complete tear or avulsion with fractured fragment) were evaluated. DRUJ stability was assessed intra-operatively after fixation of the radius. Factors potentially associated with DRUJ instability, such as age, gender, USF location, USF fragment gap, radioulnar distance, radial shortening, and TFCC foveal tear, were analyzed. Among 54 patients, 37 (69%) and 17 (31%) had USF at the base and the tip, respectively. In patients with base fractures, TFCC foveal insertion was found to be disrupted in 89% (33/37) patients (complete tear in 11 and partial tear in 22) but intact in 11% (4/37). On the contrary, in patients with tip fractures, the insertion was found to be disrupted in 88% (15/17) patients (complete tear in 2 and partial tear in 13) but intact in 12% (2/17). After fixation of the radius, total 52% (28/54) patients showed DRUJ instability. Especially, DRUJ instability was found in 57% (21/37) of ulna styloid process base fracture patients and 41% (7/17) of ulna styloid process tip fracture patients. In univariate analysis, complete tear of TFCC foveal insertion and wider USF fragment distance were associated with DRUJ instability. Tears of TFCC foveal insertion are common in patients with DRF and concomitant ulnar styloid base fractures. Based on the findings of this study, tear of TFCC foveal insertion seems to be also common in patients with DRF and concomitant ulnar styloid tip fractures. And also, DRUJ instability seems to be associated with a TFCC foveal tear independent of USF location.

Clinical evaluation of a wrist sensorimotor rehabilitation program for triangular fibrocartilage complex injuries.

Triangular fibrocartilage complex (TFCC) injuries are associated with distal radioulnar joint (DRUJ) instability and impaired wrist proprioception. Sensorimotor training of extensor carpi ulnaris (ECU) and pronator quadratus (PQ) can enhance DRUJ stability. With limited evidence on effectiveness of TFCC sensorimotor rehabilitation, this study aimed to evaluate the effects and feasibility of a novel wrist sensorimotor rehabilitation program (WSRP) for TFCC injuries. Patients diagnosed with TFCC injuries were recruited from May 2018 to January 2020 at an outpatient hand clinic in Singapore General Hospital. There are four stages in WSRP: (1) pain control, (2) muscle re-education and joint awareness, (3) neuromuscular rehabilitation, and (4) movement normalization and function. WSRP also incorporated dart throwing motion and proprioceptive neuromuscular facilitation. Outcome measures included grip strength measured with grip dynamometer, numerical pain rating scale, joint position sense (JPS) measurement, weight bearing measured with the 'push-off' test, and wrist function reported on the Patient Rated Wrist Hand Evaluation. Ten patients completed the WSRP. Mean changes were compared with minimal clinically important differences (MCID) for outcomes. All patients achieved MCID on pain, 70% of patients achieved MCID on grip strength, weight bearing and wrist function. Paired t-tests and Cohen's D for outcome measures were calculated. There were large effect sizes of 2.47, 1.35, and 2.81 for function, grip strength and pain respectively, and moderate effect sizes of 0.72 and 0.39 for axial loading and JPS respectively. WSRP presents a potential treatment approach in TFCC rehabilitation. There is a need for future prospective clinical trials with control groups.

Clinical Assessment for Distal Radioulnar Joint Instability in Patients with Distal End Radius Fracture

Background: Distal radioulnar joint (DRUJ) instability is an important cause of ulnar-sided wrist pain in distal radius fractures. By this study, it was tried to identify clinical factors associated with DRUJ instability in distal radius fractures. Materials and Methods: We prospectively reviewed all 87 patients who underwent surgery for unstable, unilateral distal radius fractures in a tertiary trauma center. Assessment of DRUJ instability was examined preoperatively, during surgery, and immediate postoperatively. Patients with clinical DRUJ instability were followed up at 6 weeks, 3 months, and 6 months, with clinical assessment of the DRUJ instability whether symptomatic or not. Results: Preoperative DRUJ instability was found in 23 patients as checked by the distal ulna ballottement test. Of these 23 patients, postoperative DRUJ instability was found in 9 patients and persisted as symptomatic DRUJ instability with ulnar-sided wrist pain till the last follow-up. Conclusion: Every distal radius fracture should be seen with the suspicion of associated DRUJ instability and the stability of DRUJ be thoroughly checked intraoperatively and postoperatively for better wrist function and better outcome after the union of distal radius fracture.

Clinical relationship between distal interosseous membrane thickness measured through magnetic resonance imaging and distal radioulnar joint stability: A retrospective study

Cadaveric studies suggest that a thick part of the distal interosseous membrane (DIOM), known as the distal oblique bundle (DOB), contributes to the distal radioulnar joint (DRUJ)'s stability. We hypothesized that the DIOM thickness, measured through magnetic resonance imaging (MRI), has a clinically significant association with DRUJ stability. We retrospectively reviewed patients, from February 2018 to April 2019, who underwent wrist MRI examination with physical examination for DRUJ stability. We evaluated the correlation between their MRI findings (i.e., triangular fibrocartilage complex [TFCC] tears and presence of the DOB) and DRUJ instability. Out of 85 patients with an average age of 42 years, 45 (53%) had foveal TFCC tears, 29 (34%) had a DOB, and 38 patients (45%) had clinical DRUJ instability. Patients with DRUJ instability had a significantly higher incidence of foveal TFCC tears (30/38, vs 15/47, p < 0.001), while DOB was absent (36/38 vs. 20/47, p < 0.001). Among 45 patients with foveal TFCC tears, only 1 out of 13 patients with a DOB had DRUJ instability, whereas 29 out of 32 patients without a DOB had DRUJ instability (p < 0.001). The odds ratio for DRUJ instability was 11.7 (95% CI 2.9-47.5, p=0.001) for foveal TFCC tear and 54.2 (95% CI 8.2-358.2, p < 0.001) for the absent DOB. Clinical DRUJ instability was less common when the DOB is present in patients with foveal TFCC tears, which supports DOB's role as a secondary DRUJ stabilizer.

The rein-type arthroscopic capsular suture for triangular fibrocartilage complex foveal tears: midterm results for 90 patients.

We describe an arthroscopic rein-type capsular suture that approximates the triangular fibrocartilage complex to the anatomical footprint, and report the results at a minimum 12month follow-up. The procedure involves two 3-0 polydioxanone horizontal mattress sutures inserted 1.5 cm proximal to the 6-R and 6-U portals to obtain purchase on the dorsal and anterior radioulnar ligaments, respectively. The two sutures work as a rein to approximate the triangular fibrocartilage complex to the fovea. Ninety patients with Type IB triangular fibrocartilage complex injuries were included retrospectively. The 12-month postoperative Modified Mayo Wrist scores, Disabilities of Arm, Shoulder and Hand scores and visual analogue scale for pain showed significant improvements on preoperative values. Postoperative range of wrist motion, grip strength and ultrasound assessment of the distal radioulnar joint stability were comparable with the normal wrist. The patients had high satisfaction scores for surgery. There were minor complications of knot irritation. No revision surgery for distal radioulnar joint instability was required. It is an effective and technically simple procedure that provides a foveal footprint contact for the triangular fibrocartilage complex.Level of evidence: IV.

Should We Repair the Pronator Quadratus in a Distal Radius Fracture with an Ulnar Styloid Base Fracture? A Biomechanical Study.

Background Merits of repairing the pronator quadratus (PQ) to restore distal radioulnar joint (DRUJ) stability after a volar approach remain controversial. Distal radius fractures are often associated with ulnar styloid fractures (USF). When involving the fovea, this USF can lead to a DRUJ instability. The PQ repair may be key in reducing this DRUJ instability. Methods This study aims to assess the biomechanical role of PQ repair in a cadaveric model of USF. In 17 forearm specimens, a USF including the fovea was executed. Positional changes of the DRUJ in forearm rotation and dorso-palmar (DP) translation were measured with variable loads (0, 2.5, and 5N) applied to the PQ origin. Results Forearm rotation and DP-translation decreased significantly with PQ loading of 5N, changing on average by 5 degrees and 0.6 mm, respectively. Conclusion We found a significant decrease in forearm rotation and DP-translation comparing a fully loaded PQ to an unloaded PQ in our cadaveric model.

Experience with Diagnosis and Management of Distal Radioulnar Joint Instability.

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.

Effect of Ulnar Head Offset on Distal Radioulnar Joint Stability

A complete ulnar head replacement may be indicated in cases of distal radial ulnar joint (DRUJ) dysfunction to address bony pathology in lieu of using a constrained total DRUJ prosthesis. Complete ulnar head implants are simple, but they may be unstable if soft tissue tension is not adequately restored. We hypothesized that incorporating an increased offset in the complete ulnar head replacement would lead to increased tension on the distal oblique interosseous ligament, increased contact force at the DRUJ, and improved joint stability. Using a specially designed jig, we measured instability by comparing displacement under load (stiffness) of the DRUJ in 10 cadaveric specimens under 4 different conditions: (1) intact, (2) native head after excision of the triangular fibrocartilage complex, (3) replacement of the ulnar head with a standard offset ulnar head, and (4) replacement of the ulnar head with an increased offset ulnar head. No soft tissue repair was done. We measured anteroposterior displacement under load with maximum translation of 10 mm or maximum loads of 50 N. We tested all specimens with the forearm positioned in neutral, supination, and pronation. Excising the triangular fibrocartilage complex decreased the average stiffness of the DRUJ to 46% of the intact state, creating a simulated state of DRUJ instability. Replacing the ulnar head with the standard offset head increased average stiffness to 54% of the intact state. Increasing the ulnar head offset with the simulated total ulnar head replacement increased average stiffness to 77% of the intact state. An increased offset ulnar head replacement improves DRUJ stability compared with a standard anatomic offset ulnar head replacement. Understanding DRUJ morphology and offset is important in the treatment of DRUJ arthritis and instability.

Fixing ulnar Styloid Fracture with Stable Distal Radioulnar Joint: A Randomized Clinical Trial.

The association between ulnar styloid fracture and distal radius fracture is common while the necessity of ulnar styloid fixation is still controversial. We have aimed to elucidate the effect of ulnar styloid fracture fixation on final outcome of distal radius fracture treatment. In a two-arm randomized clinical trial, patients with Fernandez type I distal radius fracture associated with ulnar styloid fracture in the base were divided into two groups of fixed (group A) and unfixed (group B) ulnar styloid fracture. They were followed up for 12 months using pain visual analogue scale (VAS), quick form of the Disabilities of the Arm, Shoulder, and Hand (DASH) score questionnaire, and Mayo performance score as well as wrist range of motion and grip strength evaluation. Quick DASH score was 35.4±14.0 in group A and 30.5±5.82 in group B (P=0.027) at 3-month follow-up and 29.8±18.2 in group A and 18.3±8.40 in group B At 6-month follow-up (P= 0.001). VAS score for pain was declined 4.46±2.17 and 3.64±0.96 after 6 months (P= 0.339) and 4.00±1.73 and 2.50±0.81 after 12 months (P= 0.352) in groups A and B, respectively. The mean Mayo wrist scores were measured as 59.3 and 57.8 in group A and B three months after the fracture, respectively (P= 0.504). We found no significant difference in the wrist range of motion and grip strength between two groups after three months (P>0.05). According to our findings, ulnar styloid fixation using pin and wire have an adverse effect on distal radius fixation outcomes.