The distal radioulnar joint (DRUJ) is important for normal function and load bearing of the forearm. A number of surgical procedures have been developed to try to treat painful DRUJ disorders; however, these alter forearm biomechanics and can cause painful ulna stump impingement.
The use of DRUJ arthroplasties is increasing in the treatment of DRUJ disorders in primary, revision, and salvage settings. We have undertaken a systematic review of the literature looking at their use. This has been performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Papers were assessed for outcomes, implant survival, and methodological quality.
Nineteen papers assessed ulna head replacements. The implant survival rate was 92% at a mean follow-up of 74 months. Twenty papers assessed total DRUJ replacements; all but two used the Aptis prosthesis. These implants had a survival rate of 96% at a mean of 47 months. There were two studies that assessed partial ulna head replacements. No implant revisions were reported in these two small papers. Complications were low with all implant types.
These results are similar to those in a systematic review we previously undertook. Although these data are impressive, this systematic review demonstrates that implant arthroplasty for the DRUJ has produced acceptable results but is mostly only reported in small numbers of patients. These procedures are a good salvage option in patients with ongoing DRUJ symptoms and appear to provide good longevity. More research is still needed to further evaluate these implants in larger numbers and over the longer term.
Key wordsdistal radioulnar joint – arthroplasty – outcomes – ulna head replacement – distal radioulnar joint replacement
31 Systematic Review of Distal Radioulnar Joint (DRUJ) Arthroplasty
The distal radioulnar joint (DRUJ) is important for normal function and load bearing of the forearm. 1 The DRUJ is important for forearm pronation and supination. It also bears weight; when holding a weight in an extended arm, forces are transferred across the DRUJ, sharing the load across the forearm bones.
The DRUJ can be affected by a number of pathologies, including trauma and following osteo- or rheumatoid arthritis. A number of surgical procedures have been developed for treating painful DRUJ disorders. These include: the Sauvé-Kapandji procedure, Darrach resection, or various hemiresection interposition procedures (Bower’s, Watson, etc.). 2 , 3 , 4 , 5
Any procedure that excises part of the distal ulna will alter forearm biomechanics as the load transfer that normally occurs from the radius to ulna at the DRUJ when carrying a weight is no longer possible. 6 As the forearm is suspended from the ulna because this is the bone fixed at the elbow, both the ulna and radius are unstable following its resection, and painful ulna stump impingement can occur. 5 This may be a particular problem in younger, more active patients who wish to undertake heavier manual activities. Patients with these problems will develop pain in the distal forearm with activity and often with forearm rotation.
Due to the disabling nature of these symptoms, attempts have been made to replace the excised portion of bone, primarily the ulnar head, with implants to restore more forearm stability. Initial attempts with silicone implants were unsuccessful. 7 , 8 , 9 Recently, hard-bearing DRUJ implant arthroplasties have been developed. These fall into two broad groups: isolated replacements of the ulna head (complete or partial), 10 and implants that replace the entire DRUJ articulation. 11
The use of these implants is increasing. We had previously undertaken one systematic review assessing outcomes 12 ; further results have been published. We, therefore, undertook an updated systematic review to assess the outcomes of DRUJ replacement.
31.2.1 Inclusion Criteria
We performed this systematic review in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, although without formally registering the review. 13 Articles were included in this review using the following criteria:
Patients had undergone an implant arthroplasty of the DRUJ joint either to the ulna head or a complete DRUJ replacement.
Studies had to include a minimum of four implants in four wrists.
The ranges of movement, pain, strength, complications, or failure rates were reported as outcomes.
A minimum follow-up of at least 1 year.
31.2.2 Exclusion Criteria
The exclusion criteria were:
Case reports of fewer than four cases.
Studies of nonimplant arthroplasties.
Follow-up less than 1 year.
Soft, i.e., silicone arthroplasties, as they are no longer used.
31.2.3 Literature Search
The literature review was performed using Medline, with the most recent literature search being performed on May 27, 2019. The PubMed database was searched using the following search criteria: ((Distal radioulnar joint) OR (DRUJ) OR (Distal radio ulnar joint) OR (Ulna head)) AND ((Arthroplasty) OR (replacement) OR (implant) OR (prosthesis) OR (ulnar head replacement)). MEDLINE and Embase were also searched using similar strategies. The Cochrane database was also searched.
The abstracts of these articles were then reviewed to select appropriate papers, and these papers were then obtained. If during the review of these papers, further papers were identified from the referenced literature then those papers were also obtained. We tabulated the results based on implant type to assist analysis.
31.2.4 Outcome Measures
We assessed the studies for the following outcome parameters: numbers of implants; mean follow-up; Patient-Rated Wrist Evaluation (PRWE) or Disability of the Arm, Shoulder, and Hand (DASH) scores; pain scores; ranges of movement; grip strength; complications; and survivorship. If individual patient data were presented within a paper then the mean values were calculated manually as part of the review.
31.2.5 Assessment of the Level of Evidence
We used a design classification of levels, developed by Jovell and Navarro-Rubio, to characterize the quality and consistency of the studies. 14 Using this taxonomy, we determined the quality of the evidence for the included studies and generated the strength of recommendation.
31.2.6 Assessment of Methodological Quality
Both reviewers independently assessed the methodological quality of the reported studies using the Coleman methodology. 15 If there were any discrepancies then a further discussion was undertaken until a consensus score was achieved for each study.
31.2.7 Assessment of Survivorship
Implant survivorship is important when comparing different types of implant. Reported survivorship or specific implant failures were recorded for the studies.
31.3.1 Studies Identified
The final database search produced 902 records, of which 417 were duplicates. We also identified ten records from other sources but these were all duplicate entries. This left 485 records to be screened; 433 were excluded as they did not meet the inclusion criteria, leaving 52 full text studies to review. The studies by De Smet and Peeters 16 and Garcia-Elias 17 were excluded as they have few patients (three), and three more studies were removed as they involved the use of silicone prostheses. A further study by Cooney and Berger 18 was excluded as the results were the same as those published in another paper published by the same authors at the same time. 10 The other studies were excluded as the abstracts were not clear initially and on review of the full text they were found to be review articles. Hence, a total of 41 studies were included in the final analysis (Fig. 31.1).
31.3.2 Implant Types
During the course of the literature search, three main types of implant were identified: ulnar head replacements; partial ulnar head replacements; and total DRUJ replacements. We will consider each in turn.
Ulnar Head Replacement
There were 19 studies that reported 430 uniquely implanted ulnar head replacements (Table 31.1, Table 31.2, and Table 31.3). One study by van Schoonhoven et al is a long-term follow-up study of patients reported in a previously identified study. 19 The study by Willis et al 20 originates from the same unit of that of Berger et al 10 ; it is not clear whether this is a new series of patients or whether this is a longer follow-up of the previously reported series. We have attempted to contact the authors to clarify this but without success. We have included this paper in our analysis and tables.
The implants used were predominantly the Herbert (KLS Martin Group) or the Avanta uHead (Small Bone Innovations) designs. Other implants (First Choice Ulnar Head replacement, Integra) were also used. In one study the implant was not stated. 30 We attempted to contact the authors directly for clarification but without success. In six of the studies, a mixture of implants was used. One of these studies included the results of both ulnar head replacement and partial ulnar head replacement without separating the results by partial and total implant type. 35 When assessing these papers, it was not always possible to identify separate results for each individual implant as they were reported as one dataset. 29 , 31 , 32 , 33 , 35 , 36
There is considerable heterogeneity within the study populations. The study groups included patients with rheumatoid arthritis, other forms of inflammatory arthritis disease, primary osteoarthritis, posttraumatic arthritis, and patients who had had previous surgery, i.e., salvage procedures. For studies with a homogenous patient group, the most common indication was for failed prior resection arthroplasty.
Details of the reported results are variable. While some studies present detailed results of postoperative ranges of movement, grip strength, pain and function scores, 15 of the studies did not report one or more of these parameters. A number of the papers used their own outcome parameters. All of the papers stated that the majority of patients were happy with the results and described the outcomes as good.
The reported complication rates in these series are low (Table 31.4). These include residual instability of the distal ulna, infection, implant loosening, bone resorption, tendon rupture, and implant failure. Only two papers reported implant survival rates; these are stated as 83% at 6 years of follow-up using the Avanta implant and 90% at 15 years of follow-up using a mixture of implant types. 27 , 33 Overall 34 implant failures (removal or revision) were reported, giving an implant survival rate of 92% at a mean follow-up of 74 (range 17–132) months.
Total DRUJ Replacement
We identified 20 studies with a total of 448 implants (Table 31.5 and Table 31.6). All but two of these studies used the Aptis implant (Aptis Medical); the others used a prototype implant. Seven of the studies using the Aptis implant originate from the unit of the implant designer. It is stated that the senior author in one of these papers has treated more than 231 patients with this prosthesis. 11 , 37 , 38 We contacted Dr. Scheker directly to clarify how many of these papers report individual cases and how many were duplicates. He confirmed that the only paper in this series that includes previously published patients is that of Rampazzo et al. 39 Therefore, this paper has been excluded from the survival analysis. There are other papers with crossover of patients; however, these did not meet the inclusion criteria for the review as they had too few implants, etc.
There is a considerable range of indications for total DRUJ replacement in these studies. While the majority had undergone previous surgery, there were some patients who had undergone primary DRUJ replacement and two papers where the indications were not stated. In those papers where there is a single indication for surgery this was most commonly salvage surgery following previous ulnar head excision.
The reported results are again variable. Only four of the papers report ranges of movement in all planes of movement, grip strength, pain and function scores. One paper uses its own scoring system. All papers report satisfactory or good outcomes with good patient satisfaction.
The reported complication rates are low. Complications include: infection (deep and superficial); heterotopic bone formation; tendonitis; bone resorption; implant fracture; screw irritation; loosening; and stress responses in the bones (Table 31.7). Twenty-five implant failures are reported in these studies; seven of these were in the series of prototype implants reported by Schuurman. 54 There were no implant failures in the paper using the Stability implant (Small Bone Innovations). 53 In the papers using the Aptis implants (381 implants), there were 16 revisions, i.e., an implant survival rate of 95.8% at a mean of 47.1 months (range 24–75 mo).