Kinematics of Ulnar Head Arthroplasty

Ulnar-Sided Wrist Pain: Systematic Clinical Approach and Principles of Treatment

Abstract

The source of ulnar-sided wrist pain is difficult to determine because the history and physical examination findings of various illnesses frequently coincide, and are multifactorial. Pain on the ulnar side of the wrist can be identified on the basis of the tissue from which it arises. Knowledge of the anatomy of the ulnar side of the wrist is required for correct diagnosis, as in numerous diagnostic tests. Given the complex nature of disease diagnosis, various methods have been proposed. This article discusses systematic methods for obtaining a patient's medical history, physical examination, and treatment principles to assist surgeons in determining the source of common ulnar-sided wrist pain.

Level of Evidence

D.

Association between radioulnar impingement and salvage surgical procedures of the distal radioulnar joint: influence of confounding variables

We conducted an ambispective cohort study to assess the association between symptomatic radioulnar impingement syndrome (SRUIS) and distal radioulnar joint (DRUJ) salvage surgery to examine the influence of confounders on the final effect. The outcome variable was the incidence of SRUIS and the exposure variable was the surgical procedure. Seventy-two patients with median age of 48 years (IQR 25-78) were examined using bivariate and logistic regression multivariate analyses, and confounders were analysed in 15 multivariate models. Overall, SRUIS occurred in 21 patients (29%). Bivariate analysis showed a significant association between SRUIS and type of surgical procedure, observed in 71% after Sauvé-Kapandji, 50% after Bowers and 15% after Darrach procedure. When adjusted for age, aetiology and previous surgery, the significant association disappeared. Confounding is an important factor when accounting for SRUIS after DRUJ salvage surgery. The risk of SRUIS did not depend on the procedure, but rather on patient's age, aetiology and previous surgery.Level of evidence: II.

Salvage of Painful Porous Coated Stem Ulnar Head Prosthesis With Semiconstrained Distal Radioulnar Joint Arthroplasty

PURPOSE

To determine the functional outcome and complications after conversion from a painful and unstable ulnar head prosthesis to a semiconstrained distal radioulnar joint arthroplasty.

METHODS

We conducted a retrospective review of 11 ulnar head prostheses in 10 patients with porous coated stems that were revised to semiconstrained prostheses. The median age of the patients was 47 years. The median number of wrist surgeries prior to conversion was 4 (range, 1-9). The median time from the ulnar head implant to the revision surgery was 47 months. Pre- and postoperative pain levels were recorded. Mayo Wrist Scores were calculated. Grip strength, range of motion, and complications and reoperations were recorded.

RESULTS

All patients reported moderate or severe pain before surgery, whereas 3 patients reported moderate pain after surgery. The Mayo Wrist Score improved considerably from a median of 50 before surgery to 65 after surgery. The grip strength and forearm pronation-supination showed no change following surgery. The median wrist flexion-extension range improved considerably. Follow-up was a median of 64 (range, 15-132) months after revision surgery. Removal of the ulnar head implant was described as difficult by the surgeons, except in 1 case where the implant was loose. Resection of bone from the distal ulna was often necessary. One patient needed a reoperation requiring prosthesis removal for aseptic loosening of the stem 5 years after revision. There were 2 nondisplaced periprosthetic fractures successfully treated with cast immobilization and 2 additional minor complications, 1 postoperative stitch abscess, and 1 extensor carpi ulnaris tendinitis.

CONCLUSIONS

Conversion from an ulnar head implant to a semiconstrained prosthesis provided improved pain scores and function with a low reoperation rate in this patient series. Removal of an ulnar head prosthesis can be technically challenging, but it can be performed leaving enough bone stock for immediate implantation of a semiconstrained implant.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Biomechanical evaluation of intraosseous distal radioulnar joint prosthesis: A prosthesis designed based on Sauvé-Kapandji procedure

INTRODUCTION

To avoid the DRUJ surgical procedures disadvantages, a new intraosseous distal radioulnar prosthesis designed on Sauvé-Kapandji procedure has been introduced. Stability of the prosthesis and biomechanics are to be evaluated in this article.

MATERIALS AND METHODS

On a cadaveric study, during placement of the prosthesis, biometry of the bones, prosthesis stability (in axial and lateral tractions, wrist pronation and supination, and squeeze test), wrist range of motion before and after implantation, and radiographic evaluation were done on 16 cadavers.

RESULTS

Range of motion of the wrist joint before and after the insertion of the prosthesis, had no significant difference in all six directions. Stability of the prosthesis, when rotational pronation force was exerted, was greater than when rotational supination force was exerted. The prosthesis showed significant stability against longitudinal traction forces in a way that no prosthesis dislocation was observed up to 150N forces. Stability of the prosthesis was investigated when lateral force was applied to different wrist positions. The most stable position of the prosthesis was in the case of lateral traction forces in supination where no case of dislocation was observed.

CONCLUSIONS

The intraosseous distal radioulnar prosthesis demonstrated stable structure with no effect on wrist range of motion.

LEVEL OF EVIDENCE

IV.

Distal Radioulnar oint Prosthesis

The distal radioulnar joint (DRUJ) prostheses have been available for many years and despite their superior outcomes compared to conventional DRUJ reconstructions in both short and long-term follow-ups, they have not become as popular as common hip and knee prostheses. In the current review article, at the first step, we discussed the applied anatomy and biomechanics of the DRUJ, and secondly, we classified DRUJ prostheses according to available literature, and reviewed different types of prostheses with their outcomes. Finally we proposed simple guidelines to help the surgeon to choose the appropriate DRUJ prosthesis.

Non-constrained implant arthroplasty for the distal radioulnar joint

A variety of surgical techniques are used to treat the arthritic distal radioulnar joint, which is influenced by aetiology and previous procedures. Four types of ulnar head arthroplasty exist: total ulnar head, partial ulnar head, unlinked total distal radioulnar joint, and linked distal radioulnar joint. Although long-term outcome studies are sparse, short-term clinical and biomechanical studies have shown encouraging results, leading to expanded indications. Based on our experience and a literature review, patients are advised that pain is improved but minor pain is common after strenuous activity. Ulnar neck resorption is common, however, implant loosening is rare. Sigmoid notch erosion is concerning, but appears to stabilize and not affect outcome. A partial ulnar head replacement that retains bony architecture and soft tissue restraints may have benefit over a total ulnar head in appropriate patients. If appropriate selection criteria are met, ulnar head replacement typically produces reliable results, with low revision.

Osseous Anatomy of the Distal Radioulnar Joint: An Assessment Using 3-Dimensional Modeling and Clinical Implications

PURPOSE

Using a novel technique, we assess and describe the distal radioulnar joint (DRUJ) anatomy. The purpose of this study was to provide the anatomic dimensions of the DRUJ and to evaluate contralateral symmetry.

METHODS

Computed tomography images of 100 cadaveric forearms were obtained. Three-dimensional models of the radius and ulna were generated and evaluated using 3-dimensional modeling software. Measurements of the radius of curvature of the sigmoid notch (SN) and ulnar head (UH), as well as the length of the SN and volar and dorsal lips were performed in the axial and coronal sequences. In addition, mid-coronal angular measurements were made of the SN and UH to quantify the obliquity of the DRUJ. All coronal measurements were performed with the forearm set to neutral rotation.

RESULTS

The average ulnar variance was -0.9 ± 1.8 mm. The radius of curvature of the UH (8.2 ± 1.3 mm) was markedly smaller than that of the SN (18.2 ± 8.5 mm). The length of the SN in coronal sequences increased from volar to dorsal by 65%. The mid-coronal angle (DRUJ obliquity) of the SN and UH measured 6.0 ± 9.9° and 18.0 ± 9.9°, respectively. A direct inverse correlation was demonstrated in the obliquity of the DRUJ and ulnar variance. All anatomic measurements were similar when comparing bilateral specimens.

CONCLUSIONS

The SN length tends to increase in size from volar to dorsal. Bilateral specimens from the same individual demonstrate similarities and can be cautiously used for comparison.

CLINICAL RELEVANCE

The relationships and measurements demonstrated in this study can be a guide when considering reconstructive procedures or dealing with complex fractures involving the DRUJ.

Anatomic Relationships of the Distal and Proximal Radioulnar Joints Articulating Surface Areas and of the Radius and Ulna Bone Volumes - Implications for Biomechanical Studies of the Distal and Proximal Radioulnar Joints and Forearm Bones

Background

Previous work from this laboratory has evidenced the biomechanical role of forearm osseoligamentous structures in load transfer of applied forces. It has shown that forces transmitted across the distal radioulnar joint (DRUJ) and proximal radioulnar joint (PRUJ) are similar, though not identical, under axial loading conditions. The purpose of the study was to assess the articulating surface areas of the radioulnar joints and the volumes of the forearm bones addressing the hypothesis that there may be anatomic adaptations that reflect the biomechanical function of the integrated forearm unit.

Methods

The articulating surface areas of PRUJ and DRUJ were assessed using a laser scanner in 24 cadaver forearms. The articulating joint surfaces were additionally delineated from standardized photographs assessed by three observers. The surface areas of matched pairs of joints were compared on the null hypothesis that these were the same within a given forearm specimen. An additional 44 pairs of matched forearm bone volumes were measured using water displacement technique and again compared through statistical analysis (paired sample t-test and Bland–Altman analysis).

Results

The findings of this study are that the articulating surface areas of the DRUJ and PRUJ as well as the bone volumes are significantly different and, yet, strongly correlated. The paired sample t-test showed a significant difference between the surface areas of the DRUJ and PRUJ (p < 0.05). The PRUJ articulating surface area was marginally larger than the DRUJ with a PRUJ:DRUJ ratio of 1.02. Paired sample t-test showed a significant difference between the two bone volumes (p < 0.01) with a radius to ulna bone volume ratio of 0.81. When the olecranon was disregarded, radius volume was on average of 4% greater than ulna volume.

Conclusion

This study demonstrates and defines the anatomical relationships between the two forearm bones and their articulating joints when matched for specimen. The data obtained are consistent with the theory of integrated forearm function generated from published biomechanical studies.

Arthroplasty of the distal ulna distal in managing patients with post-traumatic disorders of the distal radioulnar joint: measurement of quality of life

Objective

To measure the quality of life and clinical–functional results from patients diagnosed with osteoarthrosis of the distal radioulnar joint who underwent surgical treatment using the technique of total arthroplasty of the ulna, with a total or partial Ascension^® prosthesis of the distal ulna.

Methods

Ten patients were evaluated after 12 months of follow-up subsequent to total or partial arthroplasty of the distal ulna. All of them presented post-traumatic osteoarthrosis and/or chronic symptomatic instability of the distal radioulnar joint. The study was prospective. Seven patients had previously undergone wrist procedures (two cases with Darrach, three with Sauvé–Kapandji and two with ligament reconstruction of the fibrocartilage complex) and three presented fractures of the distal ulna that evolved with pain, instability and osteoarthrosis of the distal radioulnar joint. The following were assessed: quality of life (DASH scale); percentage degree of palm grip strength (kgf) and pronosupination range of motion in relation to the unaffected side; pain (VAS); return to work; subjective evaluation of radiography; and complications.

Results

The patients presented a mean range of motion of 174.5° (normal side: 180°). Quality of life was analyzed by applying the DASH questionnaire and the mean value found was 5.9. The mean pain score using the VAS was 2.3. The mean degree of palm grip strength (kgf) was 50.7, which represented 90.7% of the strength on the unaffected side. The complication rate was 10%: this patient presented slight dorsal instability of the ulna and persistent pain, and did not return to work. This patient is still being followed up in the outpatient clinic and occupational therapy sector, with little improvement. He does not wish to undergo a new procedure. The mean length of follow-up was 16.8 months, with a minimum of 10 and maximum of 36 months.

Conclusion

This concept is subject to the test of time. Implantation of a prosthesis is a very interesting addition to the surgical arsenal for those who are specialists in hand surgery. Arthroplasty of the distal ulna is a safe and effective method with clinical–functional and quality-of-life improvements for patients and presents a low complication rate.

Ulnar Head Replacement: 21 Cases; Mean Follow-Up, 7.5 Years

PURPOSE

To report clinical and radiographic outcomes for the Herbert ulnar head prosthesis after a mean of 7.5 years (range, 2.0-12.5 years).

METHODS

We performed 22 Herbert ulnar head prosthesis arthroplasties between 2000 and 2011. Five were primary procedures, and the remaining 17 were done after an average of 2 (range, 1-5) previous operations. The mean age at surgery was 55 years (range, 31-74 years). Follow-up including clinical examination, standardized questionnaires, and radiographic examination was done after mean 7.5 years (range, 2.0-12.5 years) in 21 cases. We used the Disabilities of the Arm, Shoulder, and Hand questionnaire, the Patient-Rated Wrist Evaluation questionnaire, and the Mayo wrist score questionnaire. Pain and satisfaction were evaluated with a 10-cm visual analog scale (VAS). Measurements of range of motion and strength for grip were recorded.

RESULTS

Wrist range of motion was not affected by the arthroplasty except for supination, which significantly improved from 55° to 70°. At follow-up, grip strength averaged 25 kg (range, 10-48 kg) in the operated wrists and 31 kg (range, 8-74 kg) on the contralateral side. Visual analog scale-pain averaged 2.9 (range, 0-8.7) during activity and 1.7 (range, 0-7) at rest. Satisfaction VAS was 8.9 (range, 4.3-10). Five patients had VAS-pain above 5 during activity, and 1 patient was dissatisfied and regretted having undergone arthroplasty. Mean outcomes were 27 (range, 5-50) for Disabilities of the Arm, Shoulder, and Hand measure, 31 (range, 0-90) for the Patient-Rated Wrist Evaluation score, and 71 (range, 30-90) for the Mayo wrist score. One patient was reoperated with capsuloplasty 9 months after the arthroplasty owing to recurrence of painful instability. Full stability was not achieved but the pain resolved. None of the implants showed any radiographic signs of loosening.

CONCLUSIONS

The Herbert ulnar head prosthesis was a safe method of treatment and provided satisfactory midterm results for selected cases of distal radioulnar joint disorders.

CLINICAL RELEVANCE

Increased knowledge of performance for ulnar head implant arthroplasty may aid surgical decision making for distal radioulnar joint disorders.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Functional Outcomes of the Aptis-Scheker Distal Radioulnar Joint Replacement in Patients Under 40 Years Old

PURPOSE

To study the functional results after Aptis-Scheker distal radioulnar joint (DRUJ) replacement in young patients.

METHODS

We performed a retrospective study selecting all patients under age 40 years, with a clinical and radiological follow-up longer than 2 years, who underwent DRUJ replacement. Patients' charts were reviewed and age at surgery, profession, hobbies, comorbidities, diagnosis, previous procedures, and complications were recorded. Preoperative and postoperative Disabilities of Arm, Shoulder, and Hand and Patient-Rated Wrist Evaluation scores, visual analog scale score, grip strength, lifting capacity, and wrist range of motion were recorded. Functional results and characteristics of the patients were correlated with linear regression. A Kaplan-Meier curve was plotted.

RESULTS

We performed 46 arthroplasties. Average patient age was 32 years. Forty-one arthroplasties were performed for pain and 5 for pain and instability. Average follow-up was 61 months. Thirty-seven patients underwent multiple procedures before DRUJ replacement (1.7 ± 1.2 procedures). Extensor carpi ulnaris release with implant coverage using a local adipofascial flap (5) or dermal-fat graft (4) was the most common procedure performed after implantation of the prosthesis. Thirty surgeries were undertaken to address complications after DRUJ replacement in 15 wrists. A total of 36 procedures not related to DRUJ replacement were performed in 15 wrists after the arthroplasty. Grip, lifting, Disabilities of Arm, Shoulder, and Hand and Patient-Rated Wrist Evaluation scores, visual analog scale score, and supination showed statistically significant improvement after surgery. Functional results were comparable in patients who received the implant with either a standard or extended stem. Patient age and number of the previous procedures did not correlate with functional results. The 5-year survival of the implant was 96%.

CONCLUSIONS

In this group of young patients, the implant improved the functional status of the extremity. The most frequent complication was extensor carpi ulnaris tendonitis, which was addressed by interposition of an adipofascial flap.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Total joint arthroplasty of the distal radioulnar joint for rheumatoid arthritis

PURPOSE

To evaluate the clinical and radiological results of primary total distal radioulnar joint (DRUJ) replacement as well as reconstruction following ulnar head excision in patients with rheumatoid arthritis (RA).

METHODS

Seventeen patients with RA underwent 19 total DRUJ replacement between 2005 and 2011. Mean age at the time of the surgery was 57 years. Mean follow-up was 39 months (range, 12-79 mo). Pain level was evaluated using a visual analog scale (VAS). Pronation and supination were recorded before and after surgery. A patient satisfaction survey was used, as well as postoperative Disabilities of the Arm, Shoulder, and Hand (DASH) and Patient-Related Wrist Evaluation (PRWE) scores. Ulnar translocation of the carpus was assessed radiographically, and the presence or absence of radiolucent zones around the implant were recorded.

RESULTS

The preoperative average VAS score for the 19 joints was 7.3. Pain decreased after surgery to 2.2. Pronation improved from 56° before surgery to 78° afterward, a 39% improvement. Supination improved from 57° before surgery to 71° afterward, a 27% improvement. Final scores were 24 for the DASH and 24 for the PRWE. Fifteen patients reported substantial pain relief. All patients were satisfied with their surgical result.

CONCLUSIONS

The results of this study suggest that total replacement of the DRUJ is of benefit to the patient with RA. Pronation was significantly increased and supination was increased but did not approach significance. Improvement in VAS score suggests that pain was decreased.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Instability of the distal radioulnar joint

The distal radioulnar joint is a complex structure necessary for forearm motion and force transmission across the wrist. Anatomic and biomechanical advances have revealed broad contributions to distal radioulnar joint stability and refined our understanding of the forces acting across it. Instability often co-occurs with other modes of pathology, such as arthrosis or malunion; and appropriate diagnosis and treatment require a comprehensive understanding of all contributing factors. Distal radioulnar joint instability can be broadly categorized as primary, post-traumatic or post-surgical. Treatment strategies include percutaneous, arthroscopic, soft-tissue, osteotomy and arthroplasty techniques. The purpose of this article is to review distal radioulnar joint instability and its management.

The biomechanical stability of salvage procedures for distal radioulnar joint arthritis

PURPOSE

To test distal forearm stability after 3 surgical procedures for distal radioulnar joint (DRUJ) arthritis.

METHODS

We tested 11 cadaver limbs with the DRUJ intact, after distal ulna-matched hemiresection, after Darrach distal ulna resection, and after unlinked total DRUJ arthroplasty. We evaluated distal forearm stability in neutral rotation, full pronation, and full supination in unweighted and 1-kg-weighted conditions. We measured dorsal/palmar translation and convergence/divergence of the distal radius relative to the ulna.

RESULTS

Under neutral rotation, whether weighted or unweighted, matched hemiresection and Darrach specimens demonstrated significant radioulnar convergence relative to intact specimens. Weighted and unweighted, DRUJ arthroplasty demonstrated similar radioulnar convergence to intact. Weighted and unweighted, only Darrach specimens showed significant radius-palmar translation compared with intact, hemiresected, and DRUJ arthroplasty. In pronation, no testing scenario, either weighted or unweighted, demonstrated statistically significant radioulnar convergence relative to intact state. In unweighted pronation, palmar translation of the radius was significantly different from the intact state for all surgical scenarios and the Darrach was significantly worse than the other procedures. In weighted pronation, palmar translation of the radius was significantly different from the intact state for all surgical scenarios and the matched hemiresection was significantly better than the other procedures. In supination, weighted and unweighted, Darrach specimens had significant radioulnar convergence relative to intact. Either weighted or unweighted, the hemiresection and arthroplasty groups demonstrated similar radioulnar convergence relative to intact. Unweighted, all scenarios demonstrated similar dorsal translation of the radius. Weighted, the Darrach group showed significant radius-dorsal translation relative to intact specimens.

CONCLUSIONS

For tested procedures, DRUJ arthroplasty overall was biomechanically superior to the other conditions except that we found greater stability in the hemiresected group in weighted pronation.

CLINICAL RELEVANCE

Knowledge of baseline biomechanical characteristics of DRUJ arthritis procedures will aid surgical decision-making and patient counseling.

Indications and early to mid-term results of ulnar head replacement

INTRODUCTION

The aim of this study was to explore the indications and show the early to mid-term results of ulnar head replacement for the treatment of pathological conditions of the distal radioulnar joint.

METHODS

Our study group comprised 52 patients with a mean age of 64 years who had 56 ulnar head replacements. Seven were implanted to salvage an unstable deletive procedure; the rest were for primary treatment of osteoarthritis, rheumatoid arthritis and trauma. Concomitant procedures along with the ulnar head replacement included wrist arthrodesis, joint replacement and tendon transfers.

RESULTS

The follow-up duration ranged from 1 year to 11 years (mean: 60 months, median: 60 months). In almost all of the patients, pain improved with a median visual analogue scale score of 2 (mean: 2.2, range: 0-8) and a median DASH (Disabilities of the Arm, Shoulder and Hand) score of 12.5 (mean: 17.9, range: 0-56). Of the 52 patients, 47 reported they would have the same procedure again.

CONCLUSIONS

Ulnar head replacement appears to be a reliable and effective procedure solving several pathological problems of the distal radioulnar joint. We present a large patient group with a short to medium-term follow-up duration.

Objective outcomes following semi-constrained total distal radioulnar joint arthroplasty

A dysfunctional distal radioulnar joint (DRUJ) can significantly compromise an individual's forearm rotation, grip, and weight bearing at the hand and wrist. This retrospective study reports surgeon- and therapist-collected objective wrist function and subjective pain scores of 10 patients who received the Scheker total DRUJ prosthesis. A review of these patients' medical records was performed to collect preoperative measurements of wrist range of motion (ROM), grip strength, and pain scores (0-10 scale). The degree of pronation, supination, flexion, extension, radial deviation, and ulnar deviation were the outcome measures used to evaluate wrist ROM. Postoperative measurements were collected at a follow up of 5 ± 1.1 years in our clinic (minimum follow-up of 2yrs). Mean final wrist flexion and extension were 32.1 ± 22.8° and 44.8 ± 13.9°, respectively. Mean final supination and pronation were 72.5 ± 14.4° and 69.5 ± 14.6°, respectively. Average grip strength was 54.9 ± 23.7 lbs. The mean pain score was 3.6 ± 3.1. Although there were no statistically significant changes in any of these outcome measures, the Scheker prosthesis improved wrist ROM (with the exception of wrist flexion) and decreased pain. Grip strength decreased by less than 1 lb but was still higher than the postoperative grip strength measurements in the literature for this prosthesis. Because of the self-stabilizing nature of this prosthesis and the satisfactory functional outcomes from this study and other studies, the Scheker prosthesis is still a viable option for DRUJ pathology that is refractory to nonimplant arthroplasties. This is a therapeutic level IV study.

Prosthetic arthroplasty of the distal radioulnar joint: historical perspective and 24-year follow-up

This is a report of the first prosthetic hemiarthroplasty and full arthroplasty, designed and implanted for the distal radioulnar joint in 1988. Two case reports are presented, with follow-up of 24 years. Experience and problems in the design of both a hemiarthroplasty and total prosthetic arthroplasty are described, in the hope that future developments may avoid past failures.

Preliminary experience with a new total distal radioulnar joint replacement

This study reports the intermediate-term results of four patients from a series eight patients who have had an insertion of a new complete distal radioulnar joint (DRUJ) prosthesis. A retrospective review was performed for all patients who underwent DRUJ joint replacement with the STABILITY Sigmoid Notch Total DRUJ System between the years of 2003 and 2008. To be included in this report, all patients had to have more than 24 months of follow-up and hand examination by the senior author. From the eight patients with this procedure, four patients met the inclusion criteria. These included one patient with painful posttraumatic arthritis, two patients with failed hemiarthroplasty, and one patient with a failed Sauvé-Kapandji procedure. Mean age at the time of surgery was 42.5 years (range: 35 to 51 years) and mean follow-up was 46 months (range: 36 to 66 months). Preoperative and postoperative assessment included range of motion, grip strength, visual analog pain scale, patient satisfaction, and radiographic evaluation. There was a successful replacement of the DRUJ in all four patients. Final range of motion showed mean pronation of 80 degrees (range: 60 to 90 degrees) and mean supination of 64 degrees (range: 45 to 90 degrees). Final grip strength on the operated extremity was 25.5 kg and averaged 73% of contralateral side. This was an improvement from preoperative grip strength of 14.5 kg visual analog pain scale decreased from 8 to 2.5 following surgery (scale: 1 to 10). Patient satisfaction was 100%. One patient returned to manual labor, one patient returned to office work, and two patients remained off work. Postoperative radiographs depict appropriate alignment of the DRUJ, and there have been no cases of subluxation or dislocation. Implant survival has been 100%. Total DRUJ joint replacement with sigmoid notch resurfacing and distal ulna replacement is an alternative to ulnar head resection in cases of DRUJ arthritis. Total DRUJ arthroplasty with this resurfacing design may provide a means of decreasing pain and restoring DRUJ stability and motion following severe trauma, failed hemiarthroplasty, or failed Sauvé-Kapandji procedure. More experience is needed with this implant to confirm these initial encouraging results. The level of evidence for this study is IV (therapeutic, case series).

Functional and radiographic outcomes following distal ulna implant arthroplasty

PURPOSE

To determine the outcome of ulnar head endoprostheses in the treatment of distal radioulnar joint instability, arthrosis, or both.

METHODS

We conducted a retrospective review of 47 patients to analyze the outcome of a single ulnar head replacement over a 10-year period. All patients reported pain or instability at the distal radioulnar joint. Standardized assessments included a patient-rated pain score, forearm range of motion, grip strength, and Mayo wrist score. We examined preoperative and postoperative radiographs for final implant position, loosening, and osteolysis.

RESULTS

We observed 47 patients for a median of 56 months (minimum, 16 mo). There was a statistically significant decrease in pain scores from 4.6 to 2.2 and improvement in the mean Mayo wrist score from 14 to 69 points after surgery. There was no significant improvement in forearm rotation and wrist function. Kaplan-Meier analysis demonstrated 83% survival at 6 years. A total of 14 patients (30%) required additional surgical procedures after primary arthroplasty. Risk factors for failure included history of previous surgery, use of an extended collar, lucency greater than 2 mm around the implant stem, and pedestal formation at the tip of the implant.

CONCLUSIONS

Distal ulna implant arthroplasty reduces pain and improves function in patients with distal radioulnar joint instability, arthrosis, or both.

Distal ulna giant cell tumor resection with reconstruction using distal ulna prosthesis and brachioradialis wrap soft tissue stabilization

This is a surgical technique report concerning the treatment of a 32-year-old male who had a giant cell tumor of distal ulna with suspected metastatic disease to the lungs. Three curettage procedures and a Darrach procedure were performed at an outlying facility. Upon the fourth reoccurrence, the patient was referred to our facility. It was established that the patient needed a distal ulna en bloc resection. To accommodate his activity requirements, reconstruction of the sigmoid notch and distal ulna was undertaken using a prosthesis. Soft tissue stabilization of the prosthesis was a challenge due to his previous procedures. This was accomplished using a brachioradialis tendon wrap.

Ulnar head implant arthroplasty: an intermediate term review of 1 surgeon's experience

Ulnar head arthroplasty has been an emerging alternative for salvage of resection arthroplasty at the distal radioulnar joint (DRUJ) since the early 1990s. Recently, it has been offered for initially treating painful arthrosis or instability of the DRUJ. This follow-up study reports a surgeon's experience treating DRUJ disorders with ulnar head arthroplasty. Twenty-two wrists in 20 patients (11 females, 9 males), 6 with no prior wrist procedures were treated between 1995 and 2006 for painful DRUJ disorders with either Herbert-Martin (Martin Medizin-Technik, Tuttingen, Germany) or Avanta (Small Bone Innovations, New York, NY) head prosthesis. Follow-up averaged 54.3 months. A standardized telephone survey determined preoperative /postoperative verbal analog pain scores and a modified Mayo Wrist Score (delineating poor, fair, good, or excellent outcomes). Data suggest that ulnar head implant arthroplasty is a reasonable treatment option for DRUJ-related pain, loss of function, or salvage of failed distal ulna resection procedures. The analog pain score statistically significant decreased by 1.68 points when comparing preoperative to postoperative scores. Average Modified Mayo Wrist Scores were good, independent of whether the procedure was primary or salvaged. No significant difference was seen between the primary or salvage group modified Mayo Wrist Scores. Whereas averaged modified Mayo scores for both the primary and salvage groups were in the good category, prostheses used as primary procedures may be associated with fewer poor or fair outcomes. Two good and 1 excellent outcome of 3 wrists requiring revision procedures suggest that even with revision of the implant arthroplasty, satisfactory results may be expected.

Comparison of the native ulnar head and a partial ulnar head resurfacing implant

PURPOSE

To assess the match in size and shape between the native ulnar head and a partial ulnar head implant in cadaver specimens.

METHODS

Ten fresh-frozen cadaver arms (6 male, 4 female, age range 79-91 years) with no history of previous distal radioulnar joint surgery were used. Radiographic measurements before and after implantation were used to compare ulnar head articular height, width, offset, and ulnar variance. Head diameter was measured using photographs of the resected ulnar heads.

RESULTS

The partial ulnar head implant consistently reproduced the natural anatomic size and shape for all variables except ulnar head height and ulnar variance. Head height was greater with the implant, but the additional height extended proximally into the distal radioulnar joint synovial recess, which is unlikely to have adverse affects. Ulnar variance match was technique dependent, with a tendency to place the implant in more neutral variance when positive variance was present before surgery.

CONCLUSIONS

Our study demonstrated that a partial ulnar head implant, which replaces the articular surfaces, can closely re-create the ulnar head anatomy. By virtue of restoring the anatomy without an extensive dissection, the clinical results should be expected to at least match the functional results of total head replacement, reduce the rehabilitation, and possibly reduce the risk of joint instability.

Reconstruction of the distal ulna: instability, impaction, impingement, and arthrosis

A number of afflictions may affect the distal radioulnar joint that can lead to severe pain, disuse, dysfunction, and disability. The disorders that affect this small anatomic region are complex, have multifactorial etiologies, and can sometimes present difficult diagnostic and treatment options. This article presents an overview of recent developments in the diagnosis and treatment of a variety of conditions that affect the joint and surrounding bone and soft tissues.

Case report: revision of failed Sauvé-Kapandji procedure with an ulnar head prosthesis

The Sauvé-Kapandji procedure has been developed in order to solve distal radioulnar joint (DRUJ) disorders. Postoperative results are variable. Complications such as painful ulnar stump, ulnar instability and loss of grip strength have often been described. We report the case of a painful ulnar stump instability resulting from a Sauvé-Kapandji procedure. After several attempted salvage procedures, a custom-made Herbert distal ulnar head prosthesis was implanted. Long-term results showed complete pain relief, improvement of the range of motion and satisfactory grip strength recovery. Our findings confirm that the Herbert custom-made ulnar head prosthesis appear to be a reliable salvage solution for failed Sauvé-Kapandji procedures.

Distal ulnar implant arthroplasty as a definitive treatment of a recurrent giant-cell tumor

Giant-cell tumors of the distal ulna are frequently recurrent and difficult to treat. A Darrach-type resection can lead to functional impairments of the wrist and hand. A case of a 42-year-old man, who underwent a distal ulna arthroplasty for recurrent giant-cell tumor of the distal ulna, is presented. The patient had two previous operations in an attempt to curette the cavity, either alone or filled with allograft bone chips. En bloc resection and distal ulnar implant arthroplasty provided a good functional outcome without any evidence of tumor recurrence at a 2-year follow-up evaluation.

Osteoarthritis of the wrist

Osteoarthritis of the wrist is one of the most common conditions encountered by hand surgeons. It may result from a nonunited or malunited fracture of the scaphoid or distal radius; disruption of the intercarpal, radiocarpal, radioulnar, or ulnocarpal ligaments; avascular necrosis of the carpus; or a developmental abnormality. Whatever the cause, subsequent abnormal joint loading produces a spectrum of symptoms, from mild swelling to considerable pain and limitations of motion as the involved joints degenerate. A meticulous clinical and radiographic evaluation is required so that the pain-generating articulation(s) can be identified and eliminated. This article reviews common causes of wrist osteoarthritis and their surgical treatment alternatives.

Hemiarthroplasty of the distal ulna with an eccentric prosthesis

Replacement arthroplasty of the ulnar head is indicated primarily for stiffness and pain as a consequence of rheumatoid, degenerative, and posttraumatic arthritis of the distal radioulnar joint. It is also successfully used in the setting of previous failed excisional arthroplasty of the distal ulna. A distal ulnar hemiarthroplasty, which anatomically recreates the native ulnar head by employing an eccentric design, is discussed. The surgical technique includes a dorsal approach and careful repair of the soft tissue stabilizers.

Eclypse: partial ulnar head replacement for the isolated distal radio-ulnar joint arthrosis

Eclypse is a pyrocarbon spacer that has been developed to substitute the articular portion of the damaged ulnar head in patients with an isolated distal radioulnar joint degenerative arthritis. The spacer can be inserted without significantly detaching the foveal insertion of the triangular fibrocartilage and preserving intact the extensor carpi ulnaris sheath. The goal of the implant is to maintain adequate separation of the 2 forearm bones throughout the entire range of pronosupination. After surgery, the joint stability is supported by the joint physiological stabilizers such as the triangular fibrocartilage and extensor carpi ulnaris muscle. To avoid dislocation of the implant at the extremes of forearm rotation, a titanium stem is implanted into the ulnar distal metaphysis with a distal peg inserted in a cylindrical hole in the center of the spacer. The loose fitting of the peg into the spacer allows some proximodistal translation and slight axial rotation of the implant, enough to adjust its position to the always-changing space between the distal ulna and the sigmoid notch concavity. Preliminary results in 3 patients are very encouraging, with minimal discomfort at the extremes of motion and a mean pronation of 65 degrees and supination of 70 degrees. At an average 11 months' follow-up, all patients were able to lift up to 4 kg of load throughout the entire range of forearm rotation without yielding.

Treatment of failed Sauvé-Kapandji procedures with a spherical ulnar head prosthesis

Radioulnar convergence is a painful complication after a Sauvé-Kapandji procedure, with a reported incidence of 13% to 39%. We evaluated 10 patients with painful radioulnar convergence treated with a spherical ulnar head prosthesis proximal to the radioulnar fusion mass. At a mean follow-up of 2.6 years, patients were evaluated clinically and radiographically to determine whether an ulnar head replacement could restore forearm stability, prevent radioulnar convergence, and reduce pain. Postoperatively, no patient had subjective complaints of radioulnar convergence or clinical signs of distal ulnar instability. Pain had improved in all patients. Grip strength, expressed as a percentage of the uninjured hand, improved on average from 27% to 55%. Range of motion improved in seven patients, worsened in two and remained the same in one. Nine of 10 patients returned to their previous occupation with an average working capacity of 76%. The prosthesis was stable radiographically in all patients. Complications included two fractures of the radioulnar fusion mass and the development of painful periprosthetic calcifications in one patient. Placement of a spherical ulnar head prosthesis after a Sauvé-Kapandji procedure provides adequate early results for patients with painful radioulnar convergence.

LEVEL OF EVIDENCE

Therapeutic study, level IV (case series).

Design and implementation of an instrumented ulnar head prosthesis to measure loads in vitro

The development of a novel instrumented implant for ulnar head replacement is presented in this study. This implant was instrumented with strain gauges to quantify bending moments about the anatomic axes of the distal ulna, and subsequently the distal radioulnar joint (DRUJ) reaction force magnitude. The implant was surgically inserted in seven cadaveric upper extremities, which were subsequently mounted in a custom joint simulator. Simulated active unresisted pronation and supination motion trials were conducted using computer-controlled pneumatic actuators to simulate forearm musculature. Passive (unloaded) trials were also conducted. The reaction force across the DRUJ ranged from 2 to 10 N in magnitude during this unresisted motion. Increased bending moment magnitudes were measured when the forearm was positioned in supination compared to pronation. The magnitude of joint bending moments showed a consistent pattern with forearm position, regardless of simulated active or passive rotation, or supination and pronation motion trials. This result illustrates that the primary influence on joint load is likely the position and contact with the radial articulation. This study of DRUJ loading should be useful for biomechanical modeling, implant design considerations and improved knowledge of articular mechanics.