The treatment of old ulnar dislocations or subluxations of the humeral joint that have been injured for more than 2 weeks is very difficult. Professor NealC.Chen from Minnesota, USA, summarized this type of injury and proposed corresponding treatment principles by analyzing the available literature, and his findings were published in JBJS in August 2014, which are translated in full below.
Key points
I. The existence of multiple types of traumatic elbow instability is helpful to help physicians recognize which tissue structures are damaged.
Patients with persistent dislocations or subluxations that occur 2 weeks after injury have poor motor function recovery and are more likely to have adverse complications
The main goal of treatment is to restore the stability of the humeral ulnar joint and restore the motor function of the elbow joint.
Contracture and scarring of soft tissues, poor joint alignment, fracture malunion, damage to the articular cartilage surfaces and ulnar nerve pathology can all cause limited motion and pain in the elbow joint.
V. Biomechanical and clinical studies support the use of radial head replacement and/or ulnar coronoid reconstruction for the treatment of patients with bone defects
For elbow fractures that have been injured for more than 2 weeks in combination with a dislocation or subluxation of the humeral ulnar joint, both initial treatment and revision surgery can be difficult. Our knowledge of this injury comes from case reports, expert opinions, and several other bulk studies reporting heterotopic ossification, elbow stiffness, and ulnar neuropathy as complications of traumatic elbow instability and its complications. The main purpose of this article is to summarize this type of injury in a general way and propose the corresponding treatment principles through the available literature.
Primary injury
Regardless of the duration of the injury, it is important to understand the original type of injury in order to identify the site of injury and potential risk. There are six main types of acute traumatic elbow instability.
Identifying the type of elbow instability
The ulnar coronoid fracture mass and its morphology on radiographs or/and CT films are the most important factors in determining traumatic elbow instability. Three types of ulnar coronoid fractures have been proposed: type 1, a transverse fracture of the coronoid tip; type 2, an anteromedial fracture of the ulnar coronoid; and type 3, a fracture of the base of the ulnar coronoid.Adams et al. found another type of ulnar coronoid fracture, an oblique anterolateral fracture, in the presence of elbow terror triad.Doomberg and Ring demonstrated that the morphology of ulnar coronoid fractures is closely related to the type of fracture instability. Type 1 fractures are more likely to occur in elbow terror triad; type 2 fractures predict medial rotational instability after elbow inversion, while type 3 injuries are closely associated with ulnar hawk fractures and elbow dislocation.
Overall outcome
Elbow fractures injured for more than 2 weeks in combination with old humeral ulnar subluxation or dislocation are very rare. The very few retrospective cases have reported inconsistent outcomes in terms of elbow range of motion and elbow joint scores. The following points are critical to note when reading the literature: (1) The available literature reports cases spanning more than 30 years and their treatments are evolving. (2) The nature of fractures in cases reported in the literature is not consistent. (3) In many cases the patients required revision surgery for treatment. (4) The literature has been published at different times, and the methods of functional efficacy assessment have been changing.
The mean duration of follow-up in case reports ranged from 1.5 to 5 years, and the number of patients included ranged from 5 to 21. Most patients had undergone surgical treatment. The mean range of elbow extension was 22° to 35°, the mean range of flexion was 111° to 129°, the mean range of posterior rotation was 43° to 76°, and the mean range of anterior rotation was 57° to 76°. Physician-assessed Mayo elbow function scores (MEPS) averaged 64 to 84 and could be considered efficacious or good. Two case reports used patient self-assessed DASH scores of 15 and 23, respectively. all studies found mild traumatic arthritic manifestations on follow-up radiographs in the majority of patients.
A number of elements are provided in the literature for understanding these clinical findings. Age, elbow mobility, and pain were the main predictors of MEPS, Broberg-Morrey score, and American Shoulder and Elbow Surgeon Score (ASES). The number of previous surgeries, elbow mobility, pain, ulnar neuropathy, and the DASH score, in turn, were strongly correlated. There is no evidence of significant differences in outcomes between fracture types.
Factors affecting outcome
Time from injury to treatment
The length of time between initial injury and definitive treatment significantly influences clinical outcomes. 21 old elbow fractures-dislocations involving the ulnar coronoid process were treated surgically by Papandea et al. 13 patients (62%) had satisfactory outcomes with MEPS scores >74. Only one of these 13 patients underwent reconstructive surgery more than 7 weeks after the initial injury. S?rensen and S?jbjerg also found that MEPS scores were significantly higher in patients who were treated within less than 6 weeks of injury.
Shortening the delayed waiting time also had a significant effect on outcome, and Lindenhovius et al. compared patients with elbow terror triad who were treated within two weeks of injury with those treated more than two weeks later, and those treated within two weeks had significantly better elbow flexion and extension mobility than those treated more than two weeks later.
Based on the above evidence, we consider an injury within two weeks to be acute and an injury two weeks or more to be nonacute. We recommend that surgery should be performed within five days for acute injuries and within two weeks for both would be ideal, however, in our experience, delayed surgery in the management of these injuries is often justifiable. If definitive treatment cannot be completed within two weeks, joint repositioning should be accomplished if possible and temporary fixation of the humeral ulnar joint with an external brace or crossed kyphosis pin fixation should be performed.
Types of elbow instability
Acute simple instability
Most elbow dislocations are not associated with fractures, but there is usually varying degrees of injury to the medial and lateral elbow ligament complexes of the flexor digitorum brevis and extensor tendons in the supracondylar region of the humerus. The majority of simple acute elbow dislocations are stable after repositioning, with ligamentous damage repaired, good functional recovery, and active flexion and extension of the elbow joint. This treatment concept has been successfully applied to acute traumatic elbow instability in combination with fractures, with the idea that ligament repair can be achieved after dislocation of the elbow joint. For example, in the triad of elbow terror, repair of the lateral ligament complex is required to maintain elbow repositioning, but repair of the medial ligament injury is usually not required. In patients with pseudodislocation or mild subluxation of the humeral ulnar joint after manipulation or surgical treatment, stable elbow joints can be achieved with active elbow flexion and extension exercises, but care should be taken to avoid inversion stress for 4 weeks.
Long-term instability
The same treatment philosophy of concentric repositioning and early exercise applies to patients with a subluxation or dislocation of the humeral ulnar joint (simple instability in the non-acute phase) who have been injured for more than 2 weeks. Even months after injury, it is still sufficient to maintain concentric stability of the elbow joint without the use of tendon graft repair reconstruction.Mahaisavariya et al. treated a total of 72 patients in this category using incisional repositioning crossed kyphotic pin fixation for 2 to 3 weeks, without intraoperative ligament repair or reconstruction, with a mean flexion arc of 82° and a mean flexion contracture deformity of 40° at an average of 48 months postoperatively. Jupiter and Ring reported five patients with missed simple dislocations of the elbow that were fixed using an incisional repositioning, hinged external fixator to refix the lateral ligamentous origin to the lateral epicondyle of the humerus. At a mean of 38 months postoperatively, the elbow joint was stable with a mean flexion arc of 123° and a mean flexion contracture of 13°.
Previously, elbow dislocations with injuries less than 4 months old would be repositioned by manipulation under anesthesia and immobilized in a cast. For old dislocations, treatment also includes partial elbow osteotomy, fascioplasty, and incisional repositioning triceps lengthening. These treatments usually improve elbow flexion and extension mobility, but still leave a legacy of flexion contracture. An important finding in all of the above case reports is that the joint space in old dislocations is filled with hyperplastic tissue that must be removed to reposition the joint.
Recurrent elbow dislocations usually result from failure of the lateral ligament complex of the elbow to heal over the lateral humeral epicondyle and are classified as lateral rotational instability requiring re-suturing or reconstruction of the lateral ligament complex. Several authors have used tendon graft reconstruction of the ligament to manage persistent subluxation or dislocation of the elbow after trauma. papandrea repaired and reconstructed the lateral ligament complex of the elbow in 5 of his 21 case studies. two of the 13 patients treated by Ring also repaired and reconstructed the lateral ligament complex, but the indications and advantages of tendon graft reconstruction are not clear. Malone et al. repaired and reconstructed the medial elbow ligament to avoid external brace fixation due to medial ligament instability at the time of heterotopic ossification removal surgery.
Complications
A dislocation or subluxation of less than two weeks can lead to alterations in the soft tissue architecture of the elbow, and the repair and reconstruction of bony structures such as the radial head or ulnar coronoid fracture alone is often insufficient to restore maintenance of elbow alignment. According to available studies in the literature, temporary fixation using crossed kerf pins or external brace fixation can help maintain joint alignment.
There is no consensus on which modality of adjunctive fixation is the best method of temporary stabilization. A hinged external fixation brace can maintain elbow joint alignment and facilitate soft tissue healing over the humeral condyle and fracture or implant healing, but the device is difficult to manipulate. The use of static external fixation for 3 to 4 weeks is also sufficient to maintain joint stability, but neither type of external fixator is easy to dress and colleagues have adverse complications, such as: nail tract infection, screw fracture, and radial nerve injury.
Immobilization of the elbow joint with a cast or external fixator, especially if there is a large gap between the humerus and ulna. Fixation of the elbow joint with crossed kyphosis pins for 3 to 4 weeks can be good to maintain repositioning, but requires upper extremity cast immobilization to protect the kyphosis pins, as well as the risk of infectious arthritis and kyphosis pin fracture. Temporary bridging plate fixation has also been used successfully to maintain joint stability.
Contracture and stiffness
For trauma after restoration of the humero-ulnar relationship, mobility of the elbow joint can be improved by incision or arthroscopic release after repair and healing of the bony pontine structures. In many case reports heterotopic osteotomy can be successful. Radiotherapy is considered an adjunct to heterotopic osteotomy; however, in acute fractures, the use of radiotherapy to prevent heterotopic osteosynthesis increases the incidence of fracture nonunion.S. rensen and S. jbjerg used oral anti-inflammatory pain for three weeks to prevent heterotopic osteosynthesis; however, other studies have not used other preventive medications. We do not use prophylactic treatment for heterotopic ossification when performing heterotomy for old elbow subluxation or dislocation.
In an injury such as elbow subluxation or dislocation, contracture, heterotopic ossification, and elbow instability may coexist. It is important to note that these factors can prevent repositioning of the humeral ulnar joint. Furthermore, removal of heterotopic ossification or contracture release surgery may potentially lead to later instability of the elbow joint.
Articular Injuries
Almost all patients with traumatic old elbow subluxation or dislocation will present with traumatic arthritis. However, the imaging presentation and clinical symptoms do not always match. Moreover, the consistency of different orthopedic surgeons using the Broberg-Morrey method to assess elbow arthritis is not ideal.
In general, most healthy and active patients can tolerate cartilage damage after elbow surgery. If complete articular surface defects are present in this group of patients, they can be managed with arthroplasty, but some patients will have residual elbow pain and instability. Some patients with articular cartilage damage and severe arthritis can also be treated with total elbow replacement surgery.
Ulnar neuropathy
Ulnar nerve lesions can have a negative impact on the postoperative elbow fracture, and Mckee et al. performed an ulnar nerve release procedure in conjunction with revision treatment of 20 failed elbows. Preoperatively, 10 patients had McGowan grade III ulnar nerve changes (paralysis of one or more intrinsic muscles). After revision elbow surgery with ulnar nerve release, seven of the 10 patients improved to grade I (no significant loss of muscle strength) and the other three recovered to grade II (loss of muscle strength but not paralysis).
Antuna et al. similarly concluded that ulnar neuropathy affects the efficacy of brachio-ulnar joint replacement surgery for primary osteoarthritis. Of the 45 patients (46 elbows) followed up to date, 13 had postoperative ulnar nerve symptoms, and six of these patients did not have ulnar nerve symptoms before surgery. The authors suggested that ulnar nerve decompression should be performed preoperatively if elbow flexion° <100°. However, there is no consensus on this approach, and it is also unclear whether it is applicable to trauma patients. In the treatment of patients with old brachio-ulnar subluxation or dislocation, regardless of the degree of elbow contracture, we usually perform ulnar nerve release and transfer surgery.
Insufficient bone mass
Old elbow subluxations and dislocations usually have insufficient bone mass in the radial head and ulnar coronoid process. The displaced humeral glides and humeral tuberosities compress the cartilage causing wear and tear of the cartilage and bone in the radial head and ulnar coronoid process.
Radial head
There is evidence of partial injury to the medial and lateral ligaments of the elbow joint in all elbow dislocations. However, in the presence of old subluxation or dislocation of the elbow joint, some degree of damage to the ligamentous tissues can be assumed, and Morrey et al. suggest that the radial head may help maintain elbow stability when the medial ligaments are not sufficient to do so. Therefore, in order to maintain elbow valgus stability the radial head should be preserved or replaced to promote repair of the medial ligament or other soft tissue structures of the elbow at normal length.
After the fracture has healed, repair or arthroplasty is performed depending on the radial head or radial neck fracture comminution. A two-part radial head or neck fracture can be repaired and reconstructed, but a radial head prosthesis should be performed if there is a nonunion or deformity of the healing elbow joint that is unstable.
Experimental biomechanical studies have shown that unipolar prostheses are more stable than bipolar radial head prostheses. Some case reports have shown satisfactory medium to long-term outcomes with either unipolar or bipolar prostheses. The bipolar prosthesis design leads to late osteolysis, whereas the unipolar prosthesis shows some humeral microcephaly and radiolucent shadowing of the radial neck region.
Ulnar coronoid process
Biomechanical experiments have been performed in an attempt to model the effects of ulnar coronoid injury, and Closkey et al. reported that when >50% of the ulnar coronoid was removed, the ulna was significantly displaced posteriorly relative to the humerus at a load of 100 N compared to a control group. Our understanding of elbow instability is evolving and the effects of rotational stresses are being considered for application to biomechanical models. schneeberger et al. found that removal of the radial head, lateral ulnar collateral ligament and 30% of the ulnar coronoid was not sufficient to cause humeral ulnar joint dislocation under posterior external rotation loading. Stabilization of the elbow joint could be restored by radial head replacement and lateral ulnar collateral ligament repair. However, when 50% of the ulnar coronoid is removed, radial head replacement, lateral ulnar collateral ligament repair, and reconstruction of the ulnar coronoid are required to restore elbow stability, and Pollock et al. found that repair of the lateral ligament to the lateral humeral condyle did not restore elbow stability if the anteromedial bone mass of the ulnar coronoid was >5 mm.
To repair the ulnar coronoid process, several modalities of bone grafting have been reported, including: a removed radial head, iliac crest, ulnar hawk tip, and allograft bone. Along with ulnar coronoid reconstruction surgery, other procedures are required, including: external fixation of the hinged elbow joint, radial head removal or replacement, and ligament repair or reconstruction.Papandrea et al. reported four cases of ulnar coronoid reconstruction surgery, using radial head graft in two cases, allograft radial head in one patient, and ulnar hawkbone graft in one patient. At a mean follow-up of 5 years after surgery, the mean MEPS score was 45 (range 35-65). 2 patients had surgical failure due to resorption of the grafted bone.
Riet et al. reported 6 cases of ulnar coronoid graft repair and reconstruction with a mean follow-up of 54 months, showing excellent results in 1 patient, good in 1, fair in 2, and poor in 2 according to the MEPS score. 5 patients had the graft fused to the ulna, while 1 was resorbed. 100). four patients with elbow terror triad had excellent postoperative outcomes, while the other four patients with ulnar hawk fractures and posterior dislocation of the elbow had 1 good and 3 poor outcomes, implying that the outcome of ulnar coronoid reconstruction may be related to the type of original elbow instability and the size of the ulnar coronoid defect.
Treatment
Although the type of injury leading to old dislocation or subluxation of the elbow joint varies greatly. Preoperative details of the mechanism of injury, previous surgery including implants, location of the ulnar nerve, and current symptoms are needed. Imaging findings, including CT and 3D reconstruction after radiographs and pressed metal shadows, are carefully evaluated. Internal fixations placed during previous surgery may need to be removed.
The treatment process for old elbow fractures with subluxation or dislocation. Consideration needs to be given to the fracture of the radial head and ulnar coronoid at the time of the initial injury and the time interval between injuries ORIF = incisional reduction and internal fixation
The surgeon needs to be prepared to remove the radial head implant (prosthesis) and know whether it is cemented or pressure-matched and whether the prosthetic bone bed is sparse. If the ulnar coronoid has also been fixed, appropriate screws and internal fixation removal instruments need to be prepared. Mark the location of the heterotopic ossification. The surgical incision should be combined with the previous incision and accommodate the pre-existing vascular-tip flap. The ulnar nerve is identified and protected intraoperatively throughout, usually requiring its transfer subcutaneously. Intraoperative use of a nerve stimulator can be helpful in this group of patients. Although the ideal approach is to preserve the ligamentous attachment point on the bone during exposure, intraoperative exposure of the ligamentous attachment point on the humeral condyle through the ligamentous gap is usually required to complete the surgical exposure. If an elbow contracture is present, the joint capsule is retracted from the humerus or a capsular release is performed to reposition the elbow joint.
Once access to the joint is confirmed, due to prolonged dislocation, a layer of hyperplastic tissue will cover the articular cartilage surface and will need to be removed to confirm the original self-cartilage. After completion of the humeral ulnar joint repositioning, the bony structures are treated. If the radial head cannot be repaired and reconstructed, the radial head will be removed for prosthetic replacement and, if necessary, the ulnar coronoid process can be reconstructed with the removed radial head. Preparation of the radial neck, if a previously operated radial head prosthesis is present, usually requires removal of the prosthesis to facilitate visualization of the ulnar coronoid process and the anterolateral structures of the elbow joint, followed by repositioning. If repair and reconstruction of the ulnar coronoid process is required, the radial head can be used for reconstruction, and in the unlikely event that the radial head is not sufficiently bony, bone graft reconstruction using the iliac crest, ulnar eminence, or allograft bone can also be performed.
When using a hinged external fixator it is necessary to drill a gristle pin transversely into the distal humerus. The ligamentous tissue of the reconstructed elbow joint is then repaired. To reposition the elbow joint, a transverse Kirschner pin through the humerus and ulna can be used to assist in the repositioning if needed. At this point, efforts should be made to repair all ligamentous tissues under appropriate soft tissue tension. Placement of an attached hinged external fixation or static external fixation brace. If there is concern about elbow instability despite placement of an external fixator, the humerus and ulna can be cross-fixed with Cremaster pins and left in place for 3 to 4 weeks.
Future research directions
Future studies need to collect data from multicenter studies and focus on the following specific questions.
(1) Which is more advantageous, static or dynamic external fixation fixation?
(2) Does the use of tendon grafts really make sense?
(3) What is the best method of ulnar coronoid reconstruction? In addition, new treatment techniques are being developed that may have an impact in the future when dealing with old or subluxed elbow dislocations, but further evaluation is needed.