Capitellar excision and hemiarthroplasty affects elbow kinematics and stability

The patient-specific implant created with 3D printing technology in treatment of a severe open distal humerus fracture with complete loss of the lateral column

The open distal humeral fracture associated with the major loss of the articular surface and bony structure is a challenging problem for orthopedic surgeons. In this case report, we describe a case of complete missing lateral column of the distal humerus with severe articular destruction of capitellum and lateral trochlear ridge which was treated with the patient-specific implant created with three-dimensional printing technology. Apart from anatomic replacement of the articular surface, the lateral collateral ligament complex and extensor muscle which are the key soft tissue stabilizers of elbow were repaired by reattaching their bony origins to the impacted iliac crest bone graft inside the implant. Due to the favorable result at 2-year follow-up, this modality is a potentially viable surgical option in treating of the severe open distal humeral fracture associated with entire lateral condylar damage.

Reconstruction of Capitellar Defect using Freeze-dried Cadaveric Allograft - A Case Report

Introduction:

Elbow instability following non-reconstructible capitellum fracture could be a source of severe pain and discomfort. There are limited treatment options to address this which include either a total elbow replacement or radiocapitellar replacement. However, these can be challenging in elderly patient with low bone stock. We present such a case in a patient who was managed with reconstruction of capitellum using freeze-dried cadaveric allograft.

Case Presentation:

A 64-year-old Caucasian female sustained a comminuted capitellar fracture. She was taken to theater for fixation of fracture, however, in view of severe communition, it was found to be non-reconstructible and hence had to be excised. She continued to have symptoms of pain and instability. She was treated with freeze-dried allograft from cadaveric bone to reconstruct the capitellum. Five months following surgery, she had no pain and achieved functional range of motion. At her final follow-up at 2 years, she remained asymptomatic and had full range of motion at elbow joint.

Conclusion:

Capitellum reconstruction using allograft showed excellent result in short term in our patient. Ours is the first case report of using an allograft to reconstruct capitellum following severely comminuted, non-reconstructible capitellum fracture following trauma in elderly patient with osteoporotic bone.

[Chronic bony instability of the elbow joint]

The high stability of the elbow joint is provided by the congruent articular surfaces in combination with soft tissue stabilizers. The main osseous contributor of elbow stability is the coronoid, which is therefore referred to as a primary stabilizer. The radial head as a secondary stabilizer together with the medial collateral ligament assures valgus stability and together with the coronoid it assures posterolateral stability. Insufficiency of the osseous stabilizers may lead to difficulties in the treatment of chronic dislocation and complex instability. Thereby reconstruction of the osseous constraints of the elbow joint is not performed in isolation from addressing insufficient soft-tissue stabilizers. Bony stabilizers and reconstructional procedures are discussed in this review.

Radiocapitellar prosthetic arthroplasty in traumatic and post-traumatic complex lesions of the elbow

Radiocapitellar prosthetic arthroplasty is a fascinating new option in the treatment of complex lesions of the elbow. The device has been developed in order to treat primitive and post-traumatic radiocapitellar degenerative arthritis, while preserving the ulnohumeral joint of the elbow. Compared to a radial head resection, it avoids valgus and axial instability of the elbow and forearm preventing ulnohumeral degeneration. Seven patients have been reviewed with a mean of follow-up of 40 months. Two of them presented with an acute trauma and five of them with a post-traumatic degenerative arthritis involving the radial compartment of the elbow. The patients' evaluation was performed using DASH and Mayo elbow performance score (MEPS). Implant overstuffing, loosening and degenerative changes of the ulnohumeral joint have been monitored with X-ray controls. All patients presented with a marked improvement in elbow function, no signs of overstuffing or ulnohumeral degeneration were observed. Two patients developed a clinically asymptomatic aseptic loosening of the radial press-fit stem. The radiocapitellar prosthetic arthroplasty shows convincing results in the treatment of symptomatic radiocapitellar degenerative arthritis. It has also been effective in acute trauma scenarios in the presence of major osteoarticular wearing or loss of the entire radiocapitellar joint.

Capitellum Fracture Fragment Excision: a Case Series

BACKGROUND

Fractures of the capitellum are rare injuries, and few studies have reported the results of fragment excision.

QUESTIONS/PURPOSES

The purpose of this study was to determine range of motion and short-term clinical outcomes for patients treated with capitellum excision.

METHODS

A retrospective review was performed to identify all patients with an isolated capitellum fracture who underwent excision as definitive treatment at our institutions. Mechanism of injury, associated elbow injuries, type of capitellum fracture, complications, and postoperative outcomes including final elbow range of motion (ROM), elbow instability, and Disabilities of the Arm, Shoulder and Hand (DASH) score were recorded.

RESULTS

Four patients met the inclusion and exclusion criteria of this study. All patients were female with an average age of 69 years (range 42-85). Based on the Bryan and Morrey classification system, three (75%) fractures were classified as type I and one (25%) fracture as type III. The average clinical follow-up was 11 months. Final examination demonstrated a mean elbow range of motion from 14° (range 0-30) of extension to 143° (range 130-160) of flexion. All patients had full forearm rotation, and there was no clinical evidence of elbow instability. The average DASH score was 18.3 (12.5-24.2) at final follow-up.

CONCLUSION

Excision of the capitellum, much like excision of the radial head, results in acceptable short-term outcome scores and elbow range of motion in patients with fractures that are not amenable to open reduction and internal fixation.

Radiocapitellar prosthetic arthroplasty: a report of 6 cases and review of the literature

BACKGROUND

Radiocapitellar prosthetic arthroplasty has recently been introduced to treat isolated degenerative arthritis of the radiocapitellar joint. Although this procedure is conceptually attractive and sound in situations in which radial head resection is inadequate, clinical experience is still limited. Its role in the treatment of isolated radiocapitellar degenerative arthritis in the ligamentous-intact elbow and forearm is not yet defined. Our purpose was to report the short-term results of 6 patients who were treated by radiocapitellar prosthetic arthroplasty for isolated radiocapitellar degenerative arthritis in the ligamentous-intact elbow, as well as to provide a review of the literature.

METHODS

Six patients were treated by radiocapitellar prosthetic arthroplasty for isolated degenerative arthritis of the radiocapitellar joint in the ligamentous-intact elbow. Their medical records were reviewed, and each patient was seen in the office. The mean follow-up period was 50 months (range, 30-64 months).

RESULTS

The implant survival rate was 100%. Pain improved in all patients and all patients were satisfied. The mean flexion-extension arc increased from 98° (range, 75°-115°) to 110° (range, 105°-120°) (P = .17), and the mean pronation-supination arc increased from 133° (range, 75°-115°) to 143° (range, 120°-170°) (P = .34). The mean Disabilities of the Arm, Shoulder and Hand score was 24.3 (range, 6.7-52.5). According to the Mayo Elbow Performance Score, there were 3 excellent and 3 good results.

CONCLUSION

The short-term follow-up results of radiocapitellar prosthetic arthroplasty for isolated radiocapitellar degenerative arthritis in the ligamentous-intact elbow and forearm seem favorable.

LEVEL OF EVIDENCE

Level IV, case series, treatment study.

The effect of distal humeral hemiarthroplasty on articular contact of the elbow

BACKGROUND

Hemiarthroplasty is a treatment option for selected distal humerus fractures. The purpose of this study was to determine the effect of distal humeral hemiarthroplasty and implant size on elbow articular contact. We hypothesized that implants of varying sizes produce different contact patterns compared with the native elbow.

METHODS

Eight cadaveric arms were tested in an elbow simulator and the kinematics recorded. Three-dimensional reconstructions of bones and cartilage were generated from computed-tomography images to determine contact patterns. The native articulation was compared to optimal, oversized, and undersized implants (Latitude Anatomic Hemiarthroplasty). Changes in contact patterns relative to the native articulation were measured using total contact area and contact patch agreement scores, defined as the sum of distance between contact patches×area, indicating how well contact patches agree with the native contact pattern.

FINDINGS

The native articulation had significantly lower ulnohumeral contact patch agreement scores compared to all tested implants (P<0.05). Mean ulnohumeral and radiocapitellar contact area decreased an average 44% (P=0.03) and 4% (P=0.07) following placement of an optimally sized implant. There was no effect of implant size on contact area or contact patch agreement score (P>0.05).

INTERPRETATION

Shape differences of elbow implants relative to the native joint may be responsible for altered contact patterns and could be improved with design modifications. These changes may predispose the elbow to arthritis. The lack of influence of implant size suggests that implant shape and materials may be more important than implant sizing during surgery.

Capitellum excision: Mechanical implications and clinical consequences

Controversy exists regarding the optimal treatment of isolated fractures of the capitellum that are not amenable to open reduction and internal fixation. Excision of the capitellum could result in instability of the elbow, though only limited the clinical or laboratory evidence exists to support this outcome. The aim of our study was to determine if capitellum excision leads to significant instability by measuring the relative change in varus-valgus displacement of the elbow. The varus-valgus displacement was recorded in 11 cadaveric elbows before and after isolated excision of the capitellum. Specimens were testing in varus-loaded and valgus-loaded positions with and without a 1 kg weight on the forearm. The varus-valgus displacement at the elbow was measured using a 3D motion capture system. Capitellum excision did not significantly change varus-valgus displacements in either the adducted, varus, or valgus position of the elbow (p = 0.80, p = 0.28, p = 0.51). Furthermore, the addition of the 1 kg external functional load to the forearm did not produce a significant change in the varus and valgus loaded positions (p = 0.16, p = 0.36). Our results demonstrate that excision of the capitellum in the setting of intact ligamentous structures does not result in significant instability in either the adducted varus loaded or valgus loaded positions of the elbow.

Posterior fixation of type IV humeral capitellum fractures with fully threaded screws in adolescents

PURPOSE

Humeral capitellum fractures comprise approximately 1% of all elbow fractures. In this study, we examined the clinical, radiographic, and functional outcomes following operative stabilization of Bryan and Morrey type IV fractures of the capitellum in adolescents. We applied headless cannulated screws in a posteroanterior direction without damaging the articular cartilage surface of the fractures.

METHODS

Eight adolescent patients (six male, two female) with a mean age of 15 ± 2.1 years (range 13-18 years) were treated for type IV (McKee) humerus capitellum fractures. In the preoperative radiological evaluation, anteroposterior and lateral radiographs and computed tomography (CT) images were performed. A lateral surgical approach was used, and cannulated fully threaded headless screws were applied in a posteroanterior direction as fixation materials in the fracture reduction. The Mayo Elbow Performance Score was used in the evaluation of elbow joint functions.

RESULTS

Patients were followed up for a mean of 24.6 months. Fracture union was achieved at a mean of 5 ± 0.92 weeks (range 4-6 weeks). The mean elbow extension flexion arc was 135° ± 13.47° (range 110°-150º) and the mean pronation supination arc was 156° ± 4.43° (150°-160°). In one patient, there was nonconformity in the humerus trochlea and in another patient, there was keloid formation on the surgical scar. All patients attained excellent results according to the Mayo Elbow Performance Score.

CONCLUSIONS

In the treatment of type IV capitellum fractures in adolescents, open reduction with a lateral surgical approach and fixation using posteroanterior directed, cannulated, fully threaded, headless screws is a reliable method to achieve a pain-free functional elbow joint.

Elbow kinematics after radiocapitellar arthroplasty

PURPOSE

Radiocapitellar arthroplasty has been proposed as a reconstructive option for combined radial head and capitellar deficiency. The purpose of this study was to assess the impact of radiocapitellar replacement on elbow kinematics. We hypothesized that with the medial collateral ligament (MCL) intact, radiocapitellar arthroplasty would replicate normal kinematics, and that a radiocapitellar arthroplasty would more closely approximate normal kinematics than an elbow with a deficient lateral column or with a deficient MCL.

METHODS

We tested 7 cadaveric arms in an upper extremity joint simulator. Each arm underwent computed tomographic scanning to aid implant size selection and computer-assisted implant insertion. We obtained kinematic data using an electromagnetic tracking system during elbow flexion. The capitellar and radial head implants were placed through an extended lateral epicondylar osteotomy. We sectioned the anterior bundle of the MCL, leaving the flexor-pronator mass intact. Outcomes of interest were varus-valgus and rotational kinematics of the ulnohumeral joint.

RESULTS

The radiocapitellar arthroplasty showed no difference in kinematics compared with the postosteotomy control. The MCL-deficient elbow showed more valgus angulation and more external ulnar rotation than the control or radiocapitellar arthroplasty in the pronated, valgus loaded position. The deficient lateral column demonstrated increased external ulnar rotation kinematics during active elbow flexion.

CONCLUSIONS

Radiocapitellar arthroplasty can restore normal elbow kinematics with the MCL intact. If the MCL is deficient, radiocapitellar arthroplasty does not restore normal kinematics.

CLINICAL RELEVANCE

Radiocapitellar arthroplasty should be considered in cases of lateral column deficiency because it maintains normal elbow kinematics during active motion. Whereas radiocapitellar arthroplasty improves the stability of the MCL-deficient elbow with deficiency of the lateral column, reconstruction of the MCL may further improve normal kinematics.