Prosthetic replacement for coronoid deficiency: report of three cases

Intra-osteal fixation of comminuted coronoid process fracture with mini plate for the treatment of complex elbow fracture

Complex elbow fractures featuring a comminuted coronoid process are infrequent and pose considerable treatment challenges. The optimal strategy for maximizing recovery of elbow function through osteosynthesis remains a subject of ongoing debate among surgeons. We applied the principle of internal fixation by implementing intra-osteal fixation with a mini plate, which facilitated the successful restoration of exceptional elbow function in the patient. This approach adeptly managed the complexity of the coronoid process fracture, encompassing its fragmentation and associated injuries, thereby demonstrating its feasibility and efficacy in achieving favorable clinical outcomes. This article investigates the viability of this surgical technique for managing such complex fractures.

Locking plate fixation in comminuted coronoid fractures with partial loss of the articular cartilage - Of basal-1 type according to the O'Driscoll classification

BACKGROUND

We have attempted to restore the arc of motion by considering trochlear-coronoid articulation as a complete circle during fixation of the coronoid, even for comminuted coronoid fractures with partial loss of articular cartilage (CCFPLAC), using various kinds of locking plates. Herein, we report the radiological and clinical outcomes after fixation of the basal-1 type of CCFPLAC (O'Driscoll classification) using our method.

METHODS

Thirty-one patients diagnosed with CCFPLAC were admitted between January 2012 and December 2020. Sixteen of these patients met the inclusion/exclusion criteria and were enrolled in this study. Surgically, the lost area (defect of articular cartilage) was never compressed or minimized, but the original height and shape of the coronoid were preserved as is. Provisionally, a few K-wires were used to maintain the original shape and position of the CCFPLAC, and various kinds of locking plates/screws were used to fix the fragment anatomically and firmly. If needed, the plate was bent to ensure stable compression of the coronoid according to its size. In a few cases, locking plates were adjusted by cutting extra screw holes.

RESULTS

Among the 16 patients, the mean age was 46.2 years, and the male:female ratio was 10:6. The mean follow-up period was 3.63 years. 8, 6, and 2 patients were designated as group 1 (isolated CCFPLAC), 2 [CCFPLAC in type 4 (terrible triad) injury), and 3 (CCFPLAC in type 5 posterior olecranon fracture-dislocations), respectively. Complete union was achieved after a mean of 8.94 weeks. The mean flexion-extension and pronation-supination arcs were 127.19 ± 4.46° and 135.31.59 ± 8.06°, respectively, which were significantly different from those on the contralateral (normal) side (p < 0.001); however, the arcs were within the functional ranges for ordinary daily living. Additionally, the functional status was satisfactory in all patients. However, Mayo Elbow Performance Score and the degree of arthritis were statistically poor in group 2.

CONCLUSIONS

CCFPLAC of the basal-1 type (O'Driscoll classification) can be treated satisfactorily if already designed and widely distributed locking plates are properly manipulated to maintain the original geometry of the coronoid according to the individual joint characteristics.

LEVEL OF EVIDENCE

Level IV, Retrospective case series.

Finite element analysis of a customized coronoid prosthesis for traumatic coronoid deficiency

BACKGROUND

Traumatic coronoid deficiency with persistent elbow instability is a challenging condition. Autologous bone graft reconstruction is often associated with a range of additional clinical problems and the outcome is often unpredictable. The purpose of this study was to design a prosthetic device that can reconstruct coronoid deficiency of any height and to evaluate its mechanical properties using finite element analysis.

MATERIALS AND METHODS

A customized coronoid prosthesis was designed based on image registration, automatic measurement, and computer-aided design. After pilot study and sample size calculation, image data collected from 6 patients who underwent bilateral complete upper extremity CT scans were reconstructed. The test was divided into 3 groups: coronoid intact, prosthesis and autograft. Regan-Morrey type II and autologous olecranon osteotomy models were established. The prosthesis and autogenous olecranon were assembled to the coronoid base. Stress was applied axially along the proximal humeral diaphysis and implant micromotion and contact mechanics of the humeroulnar joint were measured at 30°, 45°, 60° and 90° of joint flexion respectively.

RESULTS

At all flexion angles, the maximum stress on the coronoid articular surface was significantly reduced in the prosthesis and autograft groups, with the reduction being more significant in the latter (P < .001). With increasing flexion, the maximum stress at the coronoid articular surface increased significantly after autograft reconstruction (7.2 to 68 MPa, P < .001), whereas the humeroulnar joint obtained a similar contact mechanics pattern to that of the control group after prosthetic reconstruction. As the flexion angle increased, the relative micromotion of both the prosthesis and autograft increased significantly (0.5-1.6 vs. 0.2-1.2, Pmeasure time < 0.001, Pgroups < 0.001). Contact pressure and center-of-force paths of the humeroulnar joint experience abrupt stress changes at approximately 60° of flexion.

CONCLUSION

The contact stress pattern in the humeroulnar joint is similar in prosthesis and intact coronoid groups. Autograft reconstruction increases contact stresses at the articular surface and alters the joint center-of-force path. The "stress surge phenomenon" in the humeroulnar joint surface before and after 60° of flexion may be one of the mechanisms of traumatic elbow degeneration.

Coronoid Fracture Reconstruction with Ipsilateral Olecranon Osteoarticular Autograft in the Acute Setting: A Case Report

CASE

An 18-year-old male polytrauma patient sustained a high-energy posterior fracture dislocation of his left elbow associated with a comminuted and irreparable O'Driscoll type 2 subtype 3 anteromedial facet coronoid fracture. He underwent early coronoid reconstruction using ipsilateral olecranon osteoarticular autograft with incorporation of the sublime tubercle attachment of the medial collateral ligament and repair of the lateral ulnar collateral ligament. A 3-year follow-up revealed a functional, painless, congruent, and stable elbow.

CONCLUSION

Early reconstruction of a highly comminuted coronoid fracture may be a useful salvage option for the polytrauma patient, thereby avoiding complications associated with late reconstruction of posttraumatic elbow instability.

Finite element analysis of coronoid prostheses with different fixation methods in the treatment of comminuted coronoid process fracture

BACKGROUND

Comminuted fractures of the coronoid process significantly compromise the stability and function of the elbow joint. Reconstruction of the coronoid process with a prosthesis has been suggested as an alternative to restore the architecture. The purpose of this study was to investigate the strength and stability of various methods for the fixation of a coronoid prosthesis by finite element analysis.

MATERIALS AND METHODS

A coronoid prosthesis was designed based on the morphological information from computed tomography images acquired from 64 subjects in whom the top 40% of the coronoid process height was replaced. Four methods for the fixation of the prosthesis were suggested: (1) a double 2.0-mm fixation bolt, anterior to posterior; (2) a double 2.5-mm fixation bolt, anterior to posterior; (3) a single 4.0-mm fixation bolt, posterior to anterior; (4) a single 4.5-mm fixation bolt, posterior to anterior. The integrated prosthesis-bone constructs were analyzed via the finite element analysis of 10 simulated proximal ulna models with loading applied along the axis of the humerus and with three different elbow flexion angles (30°, 90°, and 130°). The maximum principal stress and the total deformation were quantified and compared.

RESULTS

A coronoid prosthesis was developed. The maximum principal stress of the fixation bolts occurred around the neck of the fixation bolt. For a comparison of the strengths of the four fixation methods, the maximum principal stress was the lowest for fixation using a single 4.5-mm fixation bolt. The value of the maximum principal stress significantly decreased with increased elbow flexion angle for all fixation methods. The maximum deformation of the fixation bolts occurred at the head of the fixation bolt. For a comparison of the maximum deformations in the four fixation methods, the maximum deformation was the lowest for fixation using a single 4.5-mm fixation bolt. The value of the maximum deformation significantly decreased with increased elbow flexion angle for all fixation methods.

CONCLUSIONS

The present study suggested that fixation of a coronoid prosthesis with a single 4.5-mm fixation bolt from posterior to anterior is an excellent option in terms of the strength and stability. Level of Evidence Experimental study.

A Novel Suture-Preset Spring Plate System (SSPS) for Comminuted Coronoid Process Fracture in the Elbow

OBJECTIVE

This study is aimed to investigate the clinical outcomes of a novel SSPS for fixation of the comminuted coronoid fracture.

METHODS

A retrospective study was carried out in the patients with comminuted fractures of the coronoid treated by SPSS fixation between January 2014 and December 2018. A total of 17 patients (17 sides) was included in our study, including 11 male and six female, with a mean age range from 18 to 60. All cases started to functional rehabilitation immediately after the operation. Clinical outcomes were evaluated both radiographically and functionally at the follow-up visit, including the elbow instability, range of motion and Mayo elbow performance score (MEPS).

RESULTS

According to the O'Driscoll classification system, there was two side of type 1.2, two of type 2.1, four of type 2.2, three of type 2.3, two of 3.1 and four of type 3.2. The surgery was carried out by Kocher and anteromedial approach in 12 patients, posterior and anteromedial approach in four, anterior approach in one. The average operation time and intraoperative blood loss was 129.41±43.87 min and 115.29±104.65 ml. The median follow-up time was 9 months (range, 6 to 15 months). The mean flexion, extension, pronation and supination motion was 138.76±8.67 degrees, 20.00±13.58, 82.94±5.32and 74.12±14.39 respectively at final follow up. The mean MEPS score was 89.76±8.46, including 11 excellent, 3 good and 3 fair result. The mean VAS score was 1.94±0.97. The mean union time of coronoid fractures was 2.77±0.31 months according to the established standard of healing. There were no significant differences in clinical outcomes among groups according to the O'Driscoll classification (P > .05) and ligament repair strategy (P > .05). No patient underwent instability or dislocation of the elbow during follow up. There were two cases with mild ulnar nerve symptoms which recovered totally at follow up. Meanwhile, there were three cases with heterotopic ossification of the elbow.

CONCLUSION

Our findings demonstrated that the SSPS can provide a reliable fixation for the comminuted coronoid fracture with satisfactory clinical outcomes.

[Coronoid reconstruction with autologous iliac crest bone graft in chronic elbow instability through a medial approach]

OBJECTIVE

Neutralizing a posteromedial rotatory instability (PMRI) caused by coronoid deficiency by restoration of the humeroulnar joint surface with an autologous iliac crest bone graft.

INDICATIONS

Surgery is indicated in patients with chronic deficiency of the anteromedial facet of the coronoid with subsequent PMRI.

CONTRAINDICATIONS

Coronoid reconstruction is not recommended in patients with advanced osteoarthritis of the elbow caused by subluxation of the humeroulnar joint. General contraindications like acute infection, pregnancy and lack of operability should also be taken into account.

SURGICAL TECHNIQUE

First, a medial approach is established and the base of the coronoid is prepared. Afterwards an autologous iliac crest bone graft is placed onto the defect and secured by screws or a plate. In addition, a reconstruction of the anterior bundle of the medial collateral ligament with an autologous tendon graft is performed.

POSTOPERATIVE MANAGEMENT

An elbow orthesis is worn for 6 weeks after surgery to avoid valgus or varus stress. There is no restriction in range of motion. A continuous passive motion elbow chair supports the patient in regaining elbow mobility.

RESULTS

Between 2015 and 2017, we treated 10 patients suffering from chronic coronoid defects with coronoid reconstruction. Eight of the patients were available for follow-up 86 weeks after surgery. The mean age was 41.4 years. In all patients, elbow range of motion and patient-related outcome measures were improved after surgery. Plain radiographs illustrated correct centering of the elbow joint. One patient had to undergo elbow arthroplasty and was excluded. Coronoid reconstruction with an autologous iliac crest bone graft restored humeroulnar joint congruency and improved satisfaction in patients suffering from chronic coronoid deficiency.

Reconstruction of the coronoid process with the olecranon tip for chronic elbow dislocation in children: A rare case report and literature review

The coronoid process of the ulna, as a key part of the elbow joint, plays an important role in maintaining elbow joint stability. Reconstruction of the coronoid process is necessary in both acute and chronic coronoid defects to restore elbow stability and avoid early joint degeneration. The olecranon tip may be a useful autologous osteochondral graft for reconstructing the same shape of the ulna coronoid process. The purpose of this report was to verify if reconstruction of the coronoid process with the olecranon tip can restore elbow stability and kinematics. Here, we report a 13-year-old boy who had undergone Kirschner-wire fixation for a left supracondylar fracture of the left humerus 9 years previously. After that, the right elbow dislocation and varus deformity gradually appeared. Imaging revealed posterolateral dislocation of the left elbow due to the absence of the coronoid process of the ulna. We reconstructed the ulnar coronoid process by intercepting the ipsilateral olecranon tip. After 22 months of follow-up, the range of motion of the left elbow joint was normal, and the cubitus varus deformity disappeared. The results of this report suggest that olecranon tip autografts are suitable to replace transverse coronoid defects. Given the patient's satisfactory clinical results, this reconstruction technique is safe and effective for the treatment of chronic elbow instability due to coronoid process defects of the ulna.

Computed tomography analysis of the relationship between the coronoid and the radial head

BACKGROUND

The coronoid process is an important stabilizer of the elbow, and its anatomy has been extensively studied. However, data documenting the relationship of the coronoid relative to the radial head (RH) are limited. The latter is a good landmark for the surgeon when débriding or reconstructing the coronoid. This imaging-based study quantified the anatomic relationship between the coronoid and the proximal radius and ulna.

METHODS

We investigated 80 cadaveric upper extremities (18 paired elbows) by 3-dimensional digital analysis of computed tomography data. After construction of a standardized coordinate system, the relationships between the coronoid, the anterior-most point of the RH, the deepest point of the articular surface of the RH, the top of the lesser sigmoid notch, and the deepest point of the guiding ridge of the trochlear notch were analyzed.

RESULTS

The mean height of the tip of the coronoid was 36 ± 4 mm (range, 26-43 mm). The mean height of the anterior-most point of the RH was 40 ± 4 mm (range, 28-47 mm). The mean distance between the tip of the coronoid and the anterior-most point of the RH was 4.5 ± 1 mm (range, 2-10 mm). For paired elbows, the heights of the tip of the coronoid and the anterior-most point of the RH were similar between sides.

CONCLUSION

This study described the relationship between the coronoid and RH. This information should prove useful when reconstructing a coronoid from a medial approach in the case of an intact RH. The difference in radiographic height between the tip of the coronoid and anterior RH in the normal elbow averages 5 mm. However, when we account for the normal cartilage thickness of the RH and coronoid, a 3- to 6-mm difference in height would be seen at surgery depending on whether the cartilage of the coronoid process is intact or removed. The distance between the tip of the coronoid and the anterior-most point of the RH is similar to the size of shavers used when débriding osteophytes during arthroscopy.

Coronoid process reconstruction with a distal clavicle autograft: an in silico analysis of fitting accuracy

BACKGROUND

The coronoid process plays a vital role in preserving elbow stability. In cases of acute or chronic deficiency of the coronoid process, reconstruction is warranted to restore stability and to avoid early joint degeneration. The distal clavicle might be a useful osteochondral autograft for coronoid reconstruction with low donor-site morbidity. This study evaluated the fitting accuracy of the distal clavicle as an autograft for coronoid process reconstruction.

METHODS

One hundred upper-extremity computed tomography scans of 85 body donors were available for this study (mean age, 69 ± 17 years; 46 male and 39 female donors; 15 bilateral specimens). Standardized 40% transverse defects of the coronoid process were digitally created; the distal clavicles were digitally harvested and placed onto the defects by a best-fit technique in 2 different orientations using commercially available software: (1) with the superior aspect of the articular surface of the graft oriented toward the coronoid tip and (2) with the inferior aspect of the articular surface of the graft oriented toward the coronoid tip. The fitting accuracy of the grafts to the native coronoid process was evaluated from lateral to medial using custom code.

RESULTS

Regardless of the orientation of the graft, the distal clavicle provided a good fit in the central portion of the coronoid process. In the lateral and medial aspects of the defect, however, the fitting accuracy of the graft declined significantly (P ≤ .044). No significant differences were observed between ipsilateral and contralateral grafts (P ≥ .199). The intrarater reliability was excellent.

CONCLUSION

The results of this study suggest that a distal clavicle autograft may be suitable to replace a transverse defect of the coronoid process; however, it may not fully reconstruct the anteromedial and anterolateral aspects of the coronoid.

Reconstruction of coronoid process of the ulna: a literature review

As a pivotal part of the elbow joint structure, the coronoid process of the ulna plays a vital role in maintaining elbow joint stability. Loss of coronoid process height causes instability of the elbow joint depending on the fracture characteristics and size. The diagnosis and treatment of coronoid process fractures has gained widespread attention from orthopedic surgeons. Nevertheless, few reports have described reconstruction of coronoid process fractures and defects that affect elbow joint stability. Treatment of elbow joint instability induced by coronoid process defects is challenging because most cases are complicated by other elbow joint injuries. Moreover, the clinical efficacy remains unclear. The present narrative review was performed to examine the research progress on reconstruction of the coronoid process. The findings of this review provide evidence for clinical repair and reconstruction of coronoid process defects and contribute to the published literature on this topic.

Prediction of the Size of the Fragment in Comminuted Coronoid Fracture Using the Contralateral Side: An Analysis of Similarity of Bilateral Ulnar Coronoid Morphology

OBJECTIVE

To evaluate the morphological similarity of bilateral coronoid process.

METHODS

A total of 128 sets of computed tomography images of bilateral coronoid process from patients between January 2015 and December 2016 were acquired for three-dimensional reconstruction to generate a coronoid process model. The patients were aged between 31.4 ± 9.3 years. The upper 40% of the coronoid process was trimmed as targeted fragment for morphological analysis. The height, length, width as well as the radius of the medial and lateral facet of the targeted fragment were compared in terms of laterality, age, and gender. To evaluate the similarity of the articular surface of the coronoid process, a local coordinate was created and coordinate transformation algorithm was developed to realign the bilateral coronoid process for the following matching. Then Delaunay triangulation was introduced for calculation of the area of the articular surface. After matching of articular surface of the upper 40% of bilateral coronoid process, the overlapping area of the articular surface was quantified to assess the similarity in morphology and compared in regard to age and gender.

RESULTS

In this study, the height of the target fragment was 12.40 ± 2.74 mm, which was 12.62 ± 2.06 mm for male patients and 12.13 ± 3.76 mm for female patients (t = 0.94, P = 0.35). The height of the target fragment was 12.79 ± 1.76 mm for patients >40 years and 13.23 ± 3.16 mm for patients <40 years (t = 1.11, P = 0.27). The height of the target fragment of left and right coronoid process was 12.26 ± 3.40 mm and 12.74 ± 2.79 mm (t = 1.15, P = 0.25). The length of the target fragment was 23.81 ± 2.67 mm, which was 23.86 ± 2.11 mm for male patients and 23.76 ± 2.85 mm for female patients (t = 0.23, P = 0.82). The length of the target fragment was 22.92 ± 1.96 mm for patients >40 years and 23.23 ± 2.14 mm for patients <40 years (t = 0.76, P = 0.45). The length of the target fragment of left and right coronoid process was 22.52 ± 2.89 mm and 21.66 ± 3.01 mm, respectively (t = 1.00, P = 0.32). The width of the target fragment was 23.12 ± 1.92 mm on average, which was 23.06 ± 1.54 mm for male patients and 23.19 ± 2.82 mm for female patients (t = 0.33, P = 0.74). The width of the target fragment was 24.82 ± 2.23 mm for patients >40 years and 23.46 ± 3.38 mm for patients <40 years (t = 1.56, P = 0.12). The width of target fragment of left and right coronoid process was 24.42 ± 2.22 mm and 24.47 ± 2.69 mm, respectively (t = 1.31, P = 0.19). The radius of medial facet was 6.44 ± 1.01 mm, which was 6.41 ± 1.39 mm for male patients and 6.47 ± 0.95 mm for female patients (t = 0.28, P = 0.78). The radius of medial facet was 6.82 ± 1.28 mm for patients >40 years and 6.46 ± 0.94 mm for patients <40 years (t = 1.31, P = 0.19). The radius of medial facet of left and right coronoid process was 6.43 ± 1.24 mm and 6.64 ± 1.34 mm (t = 1.60, P = 0.11). The radius of lateral facet was 11.84 ± 3.71 mm, which was 11.61 ± 4.24 mm for male patients and 12.11 ± 3.09 mm for female patients (t = 0.74, P = 0.46). The radius of medial facet was 11.82 ± 3.28 mm for patients >40 years and 12.46 ± 3.94 mm for patients <40 years (t = 1.02, P = 0.31). The radius of lateral facet of left and right coronoid process was 11.97 ± 5.31 mm and 10.29 ± 3.29 mm, respectively (t = 1.70, P = 0.09). The covering percentage of the articular surface of the upper 40% of bilateral coronoid process was 87% ± 12% with the covering percentage as 85.3% ± 14.2% for male patients and 90.0% ± 11.2% for female patients (t = 0.75, P = 0.41). The covering percentage was 88.2% ± 11.7% for patients >40 years and it was 87.4% ± 13.2% for patients <40 years (t = 0.98, P = 0.33).

CONCLUSIONS

The present study suggested that bilateral coronoid process shares high similarity in terms of 3D structure and articular surface morphology, which suggested that the osseous architecture of the coronoid process with comminuted fracture could be predicted by the morphological information of the contralateral side.

Prospective Blinded Evaluation of Patient-Physician Agreement Using the Summary Outcome Determination (SOD) Score

OBJECTIVE

To determine whether the Summary Outcome Determination (SOD) score demonstrates a high level of physician-patient agreement in a prospective setting with multiple raters.

PATIENTS AND METHODS

For this study, 100 patients who were being evaluated at various intervals following shoulder or elbow surgery were prospectively enrolled from May 30, 2017, through August 31, 2017. The patients' attending physicians and a member of their team (physician assistant, resident, fellow, medical student) assigned categorical and numerical SOD scores while blinded to the scores given by each other. All scores were analyzed among raters, assessing internal consistencies, agreement, and reliability.

RESULTS

The mean follow-up (interval between surgery and completion of the survey) was 31 months, with a range of 1 to 220 months. The intraclass correlation coefficient for patient and physician numerical scores was excellent at 0.82. The weighted κ value for categorical scores was 0.64. Bland-Altman analysis revealed low average discrepancy at 0.6 with a 95% CI of -3.3 to 4.5. The Cronbach α value was 0.94, indicating strong internal validity. The categorical physician-patient agreement occurred within one category 96% of the time.

CONCLUSION

This study found that the SOD score has strong agreement with excellent intraclass correlation coefficient and weighted κ values, indicating substantial agreement, reproducibility (shown by low average error), and strong internal validity. With promising results in the prospective setting, the SOD score was found to be an easy to use outcome measure with reliable agreement between patient and physician. This score has potential to be a metric revealing the "value" of a specific surgical intervention.

Management of the Posttraumatic Coronoid-Deficient Elbow

Posttraumatic coronoid deficiency is one of the most challenging scenarios even for the most experienced elbow surgeon. Surgical options can be grouped into soft tissue reconstructions, autogenous corticocancellous bone graft reconstructions, osteochondral reconstructions, and prosthetic replacement. However, the literature is inconclusive with limited cases, short follow-up, and no conclusive clinical comparative studies of these techniques. This article provides a review of the current surgical options, and we offer the senior author's (S.W.O.) perspective after years of experience with many of these techniques.

The shape match of the olecranon tip for reconstruction of the coronoid process: influence of side and osteotomy angle

BACKGROUND

The integrity of the coronoid process is critical to maintaining elbow stability. Unreconstructible fractures and chronic coronoid deficiency are challenging clinical problems with no clear solution. The purposes of this study were to investigate the shape match of the ipsilateral and contralateral olecranon tips as graft options and to determine the influence of the osteotomy angle on fitment.

METHODS

Nineteen paired cadaveric elbow joints were investigated by 3-dimensional digital analysis of computed tomography DICOM (Digital Imaging and Communications in Medicine) data. After construction of an ulnar coordinate system, the ipsilateral and contralateral olecranon tips were digitally harvested at 10°, 20°, 30°, 40°, 50°, and 60° osteotomy angles. In an overlay analysis, we compared the shape match of the ipsilateral and contralateral grafts and the different angles.

RESULTS

The ipsilateral grafts showed an average mismatch of 1.8 mm (standard deviation, 1.38 mm), whereas the contralateral grafts had a significantly lower (P < .001) mean mismatch of 1.3 mm (standard deviation, 0.95 mm). The 50° osteotomy plane showed the best shape match in comparison with the native coronoid-in both the ipsilateral and contralateral grafts. Evaluation of the intraclass correlation coefficient was calculated at r = 0.944, showing high repeatability of the measurements.

CONCLUSIONS

The contralateral olecranon tip graft showed significantly better shape matching to the native coronoid than the ipsilateral olecranon graft. Specifically, the contralateral graft more closely matched the biomechanically critical anteromedial coronoid facet. Finally, both the contralateral and ipsilateral olecranon grafts had better shape matching with the native coronoid when osteotomy was performed at higher angles, specifically 50°.

Long-term outcome of custom triflange outrigger ulnar component in revision total elbow arthroplasty

BACKGROUND

Patients missing the distal humeral condyles are prone to premature bushing wear after total elbow arthroplasty. A midterm study has demonstrated that a custom triflange outrigger ulnar component was successful in preventing this. The aim of this study was to determine whether these results remained stable over time.

MATERIALS AND METHODS

The outcomes of 6 patients who underwent revision of a loose ulnar component using a custom triflange outrigger component were reviewed in this retrospective case study. The average patient age at the time of revision was 51. The average number of prior operations was 2 (range, 1-3). The mean follow-up was 15 years (range, 10-18 years).

RESULTS

At final follow-up, the mean range of extension-flexion was 35° to 135°, and pronation-supination was 65° to 63°. The average Mayo Elbow Performance Score improved to 75 of 100. Four implants were still in place with no radiolucencies or osteolysis. Three patients required revision surgery for broken humeral stems. Two required conversion to another total elbow arthroplasty system after 18 and 14 years for humeral component loosening.

CONCLUSIONS

These components lasted an average of 4 times longer than the original ulnar components. In our experience, periarticular osteolysis caused by polyethylene wear creates a region of unsupported stem and a stress riser at the junction with the remaining well-supported stem and causes component stem fractures. The concept of an outrigger type of hinge might be useful for active patients requiring an elbow prosthesis in the setting of deficient condyles.

[Elbow dislocation fractures]

The treatment of complex elbow dislocation fractures is a challenge to both the treating surgeon as well as to the patient due to the complex bony and soft tissue anatomy of the joint. In order to establish an expedient treatment algorithm, all osseous and ligamentous injuries need to be thoroughly assessed. Furthermore, a detailed knowledge of the joint-stabilizing structures, practicable surgical approaches as well as the possible techniques for fracture fixation and/or arthroplasty are essential to facilitate early rehabilitation of the elbow and avoid injury-related complications. Any unnecessary delay in treatment of this complex injury can result in posttraumatic functional disorders, recurrent instability and secondary arthrosis. In conclusion, the goals of surgical treatment must be the correct restoration of the joint anatomy and stability as the prerequisites for any successful treatment of elbow fracture dislocations in order to enable early motion of the joint.