Salvage procedures of distal radioulnar joint (DRUJ) arthritis after distal radius fractures (DRFs) can be divided in resection arthroplasties and implant arthroplasties.
Corrective osteotomy, ulnar shortening, ligament—reinsertion or reconstruction should be considered before reconstruction of the joint.
Specific indications for the different reconstructive procedures after DRFs have not been established, and the scientific evidence for any treatment is weak.
Decision on what operative treatment to choose for DRUJ osteoarthritis is primarily based on factors related to; patient demands, especially on loading of the forearm, DRUJ morphology, and stability provided by constraining soft tissues.
A 64-year-old female with osteoporosis presents at your clinic. She has retired since a few years after knee arthroplasties, but is still living an active lifestyle, including a wish to continue playing golf.
A year earlier she was treated at a nearby hospital with external fixation and pinning for a distal radius fracture (DRF) ( Fig. 1 ). Upon initial consultation, she complains of ulnar-sided wrist pain while lifting or moving her arm.
Her grip strength is reduced by 50%, compared to the uninjured side, but range of motion is less affected, with a pronosupination of 130 degrees ( Table 1 ).
|VAS S||VAS R||VAS A||DASH||PRWE||ROM S°||ROM P°||Grip (kg)||Lift N (kg)||Lift S (kg)||Lift P (kg)||Torque S (N m)||Torque P (N m)|
She experiences pain on palpation and compression of the DRUJ as well as on resisted forearm rotation. There is a minor instability on the shear test of the DRUJ in fully pronated position. Radiographs reveal ulnocarpal impaction, because of radial shortening, and a 10 degree dorsal tilt compared to the uninjured wrist ( Fig. 1 C and D).
What treatment will you suggest to this patient?
Importance of the Problem
Involvement of the sigmoid notch of the distal radio ulnar joint (DRUJ) is known to be as high as 80% in intraarticular distal radius fractures (DRF). How many of these injuries that actually progresses to symptomatic OA and disability is not known, however data from Cooney et al. in the 70s show a prevalence of DRUJ osteoarthritis in Colles’ fractures of 5%. Diagnostic modalities and treatment techniques has changed considerably since then, and the frequency of DRUJ involvement in DRF may also be underestimated, as it has been shown that displacement of the sigmoid notch of intraarticular fractures is often missed with plain radiographs. Nevertheless, it seems like involvement of the sigmoid notch with DRF does not necessarily lead to development of OA, and a poor result. Vitale et al. hypothesize that the DRUJ may be a more tolerant joint for articular injury and malalignment than the radiocarpal joint.
Not only involvement of the sigmoid notch, but also direct injury to the joint surfaces, will cause joint degeneration. It is likely that associated ligament injuries, or a combination of ligamentous injuries and fracture later on will lead to OA. Therefore, depending on how the OA developed different treatment modalities need to be considered when the joint is reconstructed.
Patients that are affected by DRUJ arthritis may suffer from substantial physical morbidity with; disabling ulnar-sided wrist pain, decreased ability to load the wrist in all static positions, as well as during forearm rotation. Conservative treatment with pronosupination locking splints may offer some relief, but is a poor option as restriction of forearm movements is not well tolerated. Selective denervation of the DRUJ is rarely performed and current literature is sparse for this treatment. Other surgical treatments for disabling DRUJ arthritis range from simple low-cost resection arthroplasties to complex and expensive implant arthroplasties. The paucity of data—not only on the prevalence of symptomatic DRUJ OA following DRF—is even more striking when it comes to comparing treatment modalities.
What is the optimal surgical treatment for a patient with a painful osteoarthritic DRUJ after a DRF?
To sort out what treatment option is best for the individual patient, some critical factors need to be addressed. Most importantly, the patient’s functional demands and expectations, specifically regarding the ability to bear load, needs to be assessed. This is often, but not necessarily, related to the patient’s age. Previous multiple surgeries will usually affect the outcome in a negative way, why they need to be taken into consideration. DRUJ characteristics, the localization of the OA, any remaining malalignment, and signs of ligamentous injuries are other key elements that need to be identified.
If a bony deformity remains, it should usually be treated first. Not only does a corrected malalignment reduce symptoms and potentially prevent further deterioration of the DRUJ, but also enable a better starting point for later salvage procedures if needed. Corrective osteotomy of the radius is usually first considered, but an ulnar shortening might be sufficient in certain cases, such as when there is a positive ulnar variance and a suitable type of joint geometry.
Second to addressing malunion is determining if there is a concomitant ligamentous injury that can be fixed, or needs to be accounted for when the treatment strategy is decided upon. In general, surgery to repair or reconstruct ligaments can be done simultaneously to a corrective osteotomy, but many times it is better left to a later point when the outcome of the osteotomy can be evaluated.
If the primary procedures to correct for malunion or joint instability fail, or in case of a remaining severe DRUJ arthritis, salvage procedures are to be considered.
For many decades, the only surgical intervention that could be offered for an arthritic DRUJ was some kind of resection arthroplasty. Functionally, the main drawback of resection arthroplasties is the loss of solid support to the loaded hand and wrist which will affect the ability to grip and lift. As the ulnar head is removed also the separation of the distal radius and ulna is lost, sometimes causing painful dynamic impingement of the bones. Only solid DRUJ prostheses have the possibility to solve this problem, as the distal ulnar buttress is restored. This treatment option became available in the late 90s, primarily as salvage procedures for failed resection arthroplasties. Biomechanical studies which show superior properties compared to resection arthroplasties and with favorable clinical results, that seems to last, has made the joint replacements gain approval with increased popularity. In most institutions though, resection arthroplasty, with or without soft tissue stabilization of the ulnar stump remains as standard treatment of care for the osteoarthritic DRUJ.
Surgical Treatment Options
When doing our literature search, we have not found any reports on outcomes of selective denervation of the DRUJ, although the anatomical prerequisites are described.
DRUJ Resection Arthroplasties
The easiest way to remove an arthritic DRUJ surface is through simple complete ulnar head resection, popularized as the Darrach procedure. There is a great disparity in the published long-term results after Darrach’s procedure, and the majority of the literature is on patients with rheumatoid arthritis. Most studies recognize the risk for mechanical impingement, and a loss of grip strength up to 50%, and several studies have shown that only about 50% of posttraumatic patients are satisfied with the results of the procedure, especially in slightly younger age groups ( Fig. 2 ).
Some recent reports show reasonably good pain relief in the long term, but data on outcome after treatment secondary to DRF is scarce.
A magnitude of technical modifications of the procedure has been described, including, whether or not the styloid should be spared, if there should be an extraperiosteal or intraperiosteal resection or whether or not the distal ulna should be stabilized or not.
Partial Ulnar Head Resection/Hemiresection Interposition Technique (Bowers Procedure or HIT)
The technique is designed to preserve ulnocarpal ligamentous structures, and thereby theoretically provide a more stable distal ulnar end. Although there is some evidence supporting this assumption, based primarily on in vitro studies (see below—“ Complications to Resection Arthroplasties ” section), clinical follow-up show marginally better stabilizing effects of the ulnar head compared to unsupported S-K and Darrach´s procedures. The main benefit compared to Darrach’s procedure is the increase in grip strength, and ability to return to work.
There is no consensus on what capsular interposition flap should be used for optimal results. A modified approach to the initial procedure has been advocated by Bain et al., where a more robust, single ulnar compound capsular flap is used. The ECU is mobilized within its sheath to a more dorsal position, possibly acting as a dynamic stabilizer to the distal ulna.
The main difference from the HIT-procedure lies in the reshaping of the distal ulna over a 5 cm length, with no need for interposition of tissue in the articular space.
The distal ulna is shaped to match the distal curvature of the radius, with the aim to decrease the risk for impingement. Also, the ligamentous insertions of the distal ulna are relieved to produce a broad noncontact area to radius throughput full pronation and supination.
There is very little, or no, literature supporting this procedure for posttraumatic osteoarthritis after DRF, however it is likely that the results would be similar to the Darrach’s procedure.
This procedure combines DRUJ arthrodesis with a segmental resection of the distal ulna, resulting in a pseudarthrosis which allows forearm rotation.
The procedure is designed to remove the arthritic surfaces while maintaining ulnar support for the carpus as well as, for instance, the extensor carpi ulnaris tendon sheath. Thereby, the S-K procedure reduces the risk of carpal translation and permits the function of soft tissue constraints to work in a more native way. This maintains a more normal translation of forces from the hand to the forearm and is likely the reason for the consistent increase in grip strength that is seen in several studies, and the high rate of return to work.
Complications to Resection Arthroplasties
The main complication after partial- or complete resection of the distal ulna is associated with loss of the buttress function of the ulnar head. Typically, this leads to unpredictable results, because of stump instability and ensuing pathological motion in the medio-lateral and dorso-palmar planes. Most commonly this instability causes radio-ulnar convergence and impingement of the radial metaphysis to the fixed ulnar shaft. In vitro studies comparing radio-ulnar convergence between Darrach procedures and HIT procedures consistently show smaller amounts of displacement in the HIT group compared to the Darrach group. Similarly, Minami et al. showed a high ratio of instability of the ulnar stump in Darrach and S-K group, but not to the same extent after HIT procedure, or after ECU tendon stabilization of the S-K patients.
In reality, the increased convergence seen radiologically, typically presents as a “click,” or mild pain at the ulnar stump, which only requires additional surgery in a smaller number of patients.
Various stabilization procedures have been promoted to overcome the problems with radio-ulnar convergence. Slips from the extensor carpi ulnaris tendon, the flexor carpi ulnaris tendon, or both have been used to stabilize the shaft of the ulna.
Other common complications after resection arthroplasty include hardware problems and symptoms of the dorsal sensory branch of the ulnar nerve. Hardware problems that require removal in the S-K group is as common as 6%–16%.
DRUJ Implant Arthroplasties
Partial Ulnar Head Prosthesis
There are currently two partial ulnar head prostheses (Partial-UHPs) in the market. In this concept, only the articular portion of the ulnar head is substituted while part of the TFCC and other soft tissue restraints are left intact. This is an attractive solution which may lower the risk for postoperative instability-related complications compared to a total UHP. Unfortunately, there are only a few reports about these implants which cannot be ground for comparison. Therefore, it is, at the moment, not possible to make valid distinctions on when this type of implant should be preferred over the total UHPs ( Fig. 3 ).
Total Ulnar Head Prosthesis
There are several designs of total ulnar head prostheses (Total-UHPs). All are modular designs, based on a solid metal ulnar stem. The first and most well documented implant is commonly used with a ceramic head while others use metal heads. Some metal heads include the opportunity to reattach the TFCC but if this of clinical importance is debated and not proven. As total ulnar head implants prevent firm attachment of ligaments, they are heavily dependent on the stability provided by the remaining soft tissue envelope. The shape of the sigmoid notch and the contact area on the ulnar side of the radius is also important. Rigorous preoperative assessment, preferably using a CT scan, is therefore usually of great value. Any remaining malalignment of the distal radius after a previous DRF should also be recognized as this may force the UHP out of position.
Outcome after total UHP is generally good, with significant improvement in pain as seen in several studies. Additionally, low complication rates are seen, with survival rates up to 83% at 6 years and 90% at 15 years follow-up.
Although complications related to instability are a major concern regarding total UHPs, it is not directly correlated to failure or impairment. In a recent systematic review, Calcagni and Giesen also reported a high frequency of radiographic instability, while at the same time concluding that clinically relevant instability seems to be rare.
Symptomatic instability of the distal ulna can usually be avoided by careful patient selection and soft tissue handling. Minor preoperative DRUJ instability can be managed by appropriate sizing of the ulnar head and additionally sometimes by contouring of the sigmoid notch and the adjacent area during the procedure. Gross instability, or persistent instability after multiple procedures, are however considered relative contraindications to UHP.
Total Distal Radioulnar Joint Prosthesis
The total DRUJ implant is of a linked design with components that are fixed both to the ulna and the radius. It replaces not only the joint, but also the TFCC and other stabilizing soft tissues. Controversy exists if it should be classified as a constrained prosthesis, or possibly semiconstrained because of its large degree of freedom of motion.
The total DRUJ prosthesis available today appears to be the most commonly used of all implants and it is the most well documented on the market. The general impression is that this implant provides satisfactory results even in the most complicated cases but high complication rates have been reported. As many of the complications occur early, and appear to be avoidable, it is likely that these complications are related to the fact that this type of arthroplasty is technically demanding.
Gross instability, for any reason, in addition to DRUJ arthritis is the main indication for the total DRUJ implant. It is especially useful after previous multiple failed procedures and after failed implant arthroplasties. Malunions in the distal—radius or ulna, osteoporosis, as well as possible future need for a total wrist replacement, are relative contraindications.
Finding the Evidence
The search was made in Cochrane, Medline, and Embase ( Fig. 4 ) electronic databases. We based the search on following terms; Distal radioulnar joint, DRUJ, implant, arthroplasty, denervation, resection, replacement, prosthesis, and salvage.