Radial head prosthesis: results overview

Self-assessment of Elbow Mobility as a Reliable Method in the Postoperative Follow-up Examination of Radial Head Fractures

Sufficient follow-up of fractures is often difficult, due to age-related, health-related or geographical reasons. Self-assessment of the patient's functional outcome could be an alternative to a personal medical examination. There is a lack of validated questionnaires to record these parameters for elbow injuries. The aim of the study was to validate the patient's self-assessment of the range of motion following surgical treatment of complex radial head fractures.50 patients (42% women) with a mean age of 49.7 ± 13.8 years (range 25-82 years) with a surgically treated radial head fracture (Mason III or IV) were examined, 39.6 ± 23.3 months postoperatively. The fracture was treated with radial head reconstruction (60%) or radial head prosthesis (40%). The follow-up examination included the assessment of elbow mobility using a questionnaire (Elbow Motion Assessment Score) and physical examination using a goniometer. In addition, quality of life was assessed using the SF-36 Health Survey. The agreement of the mobility was recorded as a percentage using Spearman's correlation.Exact agreement between examiner and patient was achieved at 54% in flexion, 40% in extension, 86% in pronation and 54% in supination. The median deviations in agreement were 10° in extension and flexion and 20° in pronation and supination. The correlations were r = 0.550 (flexion), r = 0.841 (extension), r = 0.808 (pronation) and r = 0.754 (supination). Patients who agreed with the examiner on the movements achieved a higher score in the SF-36 Health Survey than patients who did not agree with the examiner (50.5 to 54.1 vs. 40.0 to 45.5).The survey of the range of motion by the patient using a questionnaire showed a high level of agreement with the measurement by an objective examiner. Such self-assessment can therefore be seen as a suitable, cost-effective alternative in the follow-up examination of surgically treated radial head fractures.

Modern Treatment of Supracondylar Humeral Fractures in Children

Supracondylar humeral fractures are the most common type of elbow fractures in children. The treatment methods vary depending on the type of fracture (Gartland classification), which can be conservative or surgical. There is no clear consensus or guidelines to dictate the treatment of complicated supracondylar humeral fractures (Gartland types II and III). Gartland type II and III fractures are most frequently treated with closed reduction and percutaneous Kirchner-wire pinning or open reduction with K-wire pinning, depending on the degree of displacement and the orthopedic surgeon's preference. Most studies recommend avoiding open reduction because of prolonged hospitalization and higher rates of complications. Orthopedic surgeons have different opinions regarding the Kirschner pin placement technique. Studies suggest that only lateral pinning is safe and effective, but medial and lateral pinning is proven to give more stability; there is always a risk of iatrogenic ulnar nerve damage during surgery. Modern treatment of supracondylar humeral fracture in children should focus on minimally invasive techniques and avoid open reduction, when possible, to ensure the best outcome for the patients. This scoping review's purpose is to gather the available information on the topic in one place and to underline the lack of clear protocols.

Radial neck osteolysis after radial head replacement: Functional impact and risk factors

INTRODUCTION

Onset of radial neck osteolysis (RNO) has been reported after radial head replacement (RHR), but data are sparse regarding impact and risk factors. We therefore conducted a retrospective study, 1) to quantify RNO after RHR, 2) to assess clinical and radiological impact, and 3) to identify risk factors.

HYPOTHESIS

RNO prevalence is high, but functional impact is limited.

MATERIAL AND METHOD

A single-center retrospective study included all patients undergoing RHR for acute radial head fracture between 2008 and 2017: 53 patients, with a mean age of 53.8±15.7 years [range, 21-85 years]. At a minimum 2 years' follow-up, patients were assessed clinically on joint range of motion and Mayo Elbow Performance Score (MEPS) and radiologically on standard radiographs. Associations between RNO and various parameters were assessed.

RESULTS

At a mean 46.7±19.8 months' follow-up [range, 24-84 months], RNO was found in 54.7% of cases (29/53), with mean 4.0 ±2.8mm distal extension [range, 1.2-13.4mm], corresponding to 13.4±7.3% of stem height [range, 2.7-27.7%]. RNO at last follow-up was not significantly associated with reduced flexion-extension (121.9° versus 114.0°; p=0.11), pronation-supination (152.6° versus 138.3°; p=0.25) or MEPS (84.7 versus 84.8; p=0.97), or with higher rates of postoperative complications (11/29 (37.9%) versus 7/24 (29.2%); p=0.782) or surgical revision (11/29 (37.9%) versus 10/24 (41.7%); p=0.503). RNO was significantly associated with cementless fixation (19/29 (65.5%) versus 7/24 (29.2%); p=0.01), unipolar prosthesis (21/29 (72.4%) versus 7/24 (29.2%); p=0.002), high filling-ratio, whether proximal (88% versus 77%; p=0.002), middle (84% versus 75%; p=0.007) or distal (69% versus 59%; p=0.032), and shorter radial stem (33.2mm versus 46.3mm; p=0.011). No demographic parameters showed significant association with RNO at last follow-up.

CONCLUSION

RNO was frequent after RHR, but without clinical or radiological impact in the present series. The risk factors identified here argue for involvement of stress shielding.

LEVEL OF EVIDENCE

IV, cohort study.

Does stress shielding after radial head arthroplasty affect functional outcomes?

BACKGROUND

Various complications related to the prosthesis, such as implant loosening and stress shielding phenomenon, could develop after prosthetic replacement of the radial head. Stress shielding is known to occur around rigidly fixed implants. The purpose of this study was to evaluate the clinical influence and causative factors of the stress shielding phenomenon after radial head arthroplasty (RHA).

METHODS

Clinical records and radiographs of 56 patients with unreconstructable radial head fractures who received radial head replacement between 2009 and 2019 were reviewed. Exclusion criteria were infection, loosening, and follow-up of less than 24 months. After exclusion, 35 patients were enrolled. Patients were divided into two groups: an anatomical press-fit group (Anatomical Radial Head System; Acumed, Hillsboro, OR, USA) and a round bipolar cemented group (RHS; Tornier, Montbonnot Saint-Martin, France). Stress shielding around the prosthesis was assessed in the serial radiological examination. Clinical results were assessed using Mayo elbow performance score (MEPS), Quick Disabilities of the Arm, Shoulder, and Hand (q-DASH) score, range of motion (flexion-extension arc and pronation-supination arc), and visual analog scale score (VAS). Correlations between stress shielding phenomenon and demographic data and functional results were analyzed.

RESULTS

At an average follow-up of 43.06 (± 14.6) months, 14 (40%) out of 35 fixed stems demonstrated stress shielding. Our results showed that the rate of stress shielding was significantly higher in cases with a bilateral ligament injury and in the anatomical press-fit group (p = 0.028 and p = 0.0091, respectively). However, stress shielding around prostheses did not affect the clinical results (p > 0.05).

CONCLUSION

The stress shielding phenomenon around radial head prosthesis may vary according to prosthetic design and severity of ligament injuries. Stress shielding does not affect the mid-term outcomes in the treatment of acute fractures of the radial head.

LEVEL OF EVIDENCE III

Retrospective Cohort Comparison; Treatment Study.

Clinical long-term results of radial head arthroplasty in comminuted radial head fractures

Modern radial head prostheses have recently become more common in the treatment of comminuted radial head fractures. The goal of this study was to evaluate how well the EVOLVE^® modular metallic radial head implant prosthetic restores the functional range of motion and stability of the elbow. 30 patients with comminuted radial head fractures received an arthroplasty with an EVOLVE^® prosthesis in our institution. 20 of those patients were available for long-term follow-up (mean > 10 years). The outcomes were assessed on the basis of pain, motion, and strength. The overall outcome was scored with functional rating scores. According to the Broberg-Morrey elbow evaluation score, after a mean follow-up period of 10.2 years, ten (50.0%) patients were rated as very good, four (20.0%) as good, six (30.0%) as satisfactory, and none as poor. In the long-term results the Broberg-Morrey score increased from 79 (in short-term results) to 89 points. The Disabilities of the Arm, Shoulder, and Hand (DASH) outcome measure questionnaire showed an average of 16.2 points. Initially, patients had an extension deficit of 20°, which was reduced to 5° at the latest follow-up. In our long-term results, an improvement in the function of the elbow was observed after arthroplasty using a metallic modular radial head implant. Comminuted radial head fractures with elbow instability can be treated effectively with the EVOLVE^® radial head prosthesis, which restores stability in acute treatment. Our long-term results after 10.2 years demonstrate good functional outcome and low major complication rate. IV.

Fracture Pattern Influences Radial Head Replacement Size Determination Among Experienced Elbow Surgeons

BACKGROUND

Correct sizing is challenging in radial head replacement and no consensus exists on the implant's optimal height and width to avoid elbow stiffness and instability. Studies exists, suggesting how to appropriately choose the implant size, but the manner by which the fracture pattern influences the surgeons' operative choices was not investigated.

METHODS

The radial heads of four fresh-frozen cadaveric specimens were excised, measured, and fractured to simulate four patterns: three fragments (A); four fragments (B); comminuted (C); comminuted with bone loss (D). Nine examiners were asked to indicate first the maximum diameter of the radial heads with the help of dedicated sizing dishes and then the appropriate implant size with trial implants. Accuracy and precision were determined. A coefficient of variation was calculated and agreement was evaluated with the Bland-Altman method.

RESULTS

Accuracy and precision of radial head diameter estimation with dedicated sizing dish were 96.73% and 93.64%, (best pattern, D; worst, C). Accuracy and precision of radial head diameter estimation with trial implants were 99.71% and 90.66% (best pattern, A; worst, D). Frequent modifications occurred between the initial radial head size proposal based on the sizing dish and the radial head size chosen after use of the trial implants (47.2%).

CONCLUSIONS

Diameter estimation of radial heads with dedicated sizing dishes may be underestimated in comminuted fractures; when bone loss is present, this may lead to an overestimation, especially when using trial implants. Care is essential to determine the optimal size of the implant and to avoid overlenghtening and oversizing, which can be responsible for implant failure.

LEVEL OF EVIDENCE

Basic Science Study.

CLINICAL RELEVANCE

Knowledge of the manner by which the fracture pattern influences radial head replacement size estimation can help preventing overlenghtening and oversizing during this procedure.

Acute Joint Blockage due to Abrasion-Related Dislocation of a Silastic Radial Head Prosthesis: A Histological Examination after 14 Years of Durability

The implantation of a radial head prosthesis can take place as a therapeutic option after radial head fracture. There are various implants for this purpose. Many studies and case reports about silastic radial head prosthesis implantation describe foreign body reactions with accompanying synovitis and poor functional results. A few studies have investigated the reason for the material failure and the accompanying synovitis. The case report presented shows an unusually long durability of an in situ 14-year silastic radial head prosthesis. 14 years after implantation, a previously full-time working and healthy patient presented himself with a dislocation of the silastic radial head prosthesis and atraumatic joint blockage of the right elbow triggered by a negligible movement. The prosthesis was removed surgically. We found a macroscopic foreign body reaction intraoperatively. In a histopathological examination, with hematoxylin and eosin staining (HE) in 40x and 100x magnification, we have seen an aseptic inflammatory response to foreign bodies with activated epithelial cells and multinucleated giant cells with intracytoplasmic foreign material. Due to these problems, the silastic radial head prosthesis is no longer used today. However, there are still patients with the implanted silastic radial head prosthesis, which should therefore be checked regularly. A metal prosthesis also does not seem to be an optimal alternative due to cartilage wear and loss of ROM. The choice of prosthesis material should be selected carefully and patient-specific in radial head prosthetics according of the results presented.

Therapeutic Effect of Resection, Prosthetic Replacement and Open Reduction and Internal Fixation for the Treatment of Mason Type III Radial Head Fracture

Aim of the Study: Mason type III radial head fractures are a source of concern due to the severe injury and poor recovery. At present, radial head resection, open reduction and internal fixation (ORIF), and prosthetic replacement are three common treatment methods for these fractures. The clinical efficacy and postoperative complications are controversial, which makes it difficult for physicians to determine the most appropriate regimen. Herein, this present prospective, non-randomized, parallel-controlled study was conducted to compare the therapeutic effects and identify the most effective treatment method for Mason type III radial head fracture. Materials and Methods: We assessed patients with Mason type III radial head fracture treated with resection, prosthetic replacement, and ORIF to compare preoperative and postoperative pain condition, elbow joint function, curative effect, and complication rate. A visual analog scale was used to score pain. The elbow joint function was observed using the Broberg-Morrey elbow joint score. Results: No significant differences were found in patient demographics among the resection, prosthetic replacement, and ORIF groups. The prosthetic replacement and ORIF procedures were more complex and had higher technical requirements. Prosthetic replacement and ORIF enabled higher elbow joint scores and lower pain scores than resection. Excellent and good ratings were highest and complication rates were lowest in the prosthetic replacement group, followed by the ORIF group. Conclusion: Our results showed that prosthetic replacement is more effective than ORIF and radial head resection in relieving pain, functional recovery and reducing complications in the treatment of Mason type III radial head fractures.

Radial Head Resection versus Arthroplasty in Unrepairable Comminuted Fractures Mason Type III and Type IV: A Systematic Review

Unrepairable comminuted fractures of the radial head Mason type III or type IV have poor outcomes when treated by open reduction and internal fixation. Radial head resection has been proposed as good option for surgical treatment, while in the last decades, the development of technology and design in radial head prosthesis has increased efficacy in prosthetic replacement. The present review was conducted to determine the best surgical treatment for comminuted radial head when ORIF is not possible. Better outcomes are reported for radial head arthroplasty in terms of elbow stability, range of motion, pain, and fewer complications compared to radial head excision. Nevertheless, radial head resection still can be considered an option of treatment in isolated radial head fractures with no associated ligament injuries lesion of ligaments or in case of older patients with low demanding function.