Radial head arthroplasty with a modular metal spacer to treat acute traumatic elbow instability

Does the polarity of radial head arthroplasty affect functional outcomes? A systematic review and meta-analysis

BACKGROUND

Radial head arthroplasty allows a high degree of customizability, and implant polarity has emerged as an important variable. The purpose of this meta-analysis was to evaluate differences in functional and clinical outcomes between patients receiving monopolar and bipolar radial head prosthetic implants.

METHODS

A systematic review and meta-analysis were employed, and 65 articles were identified in three databases. Twelve articles contained non-English or insufficient text and were consequently excluded, and 20 others did not contain sufficient data or follow-up. The remaining 33 articles were qualitatively and quantitatively reviewed.

RESULTS

In total, 33 populations were identified, with 809 unduplicated patients: 565 with monopolar and 244 with bipolar implants. In these respective patients, the mean follow-up was 40.2 and 56.9 months. Average Mayo Elbow Performance Score were 86.7 and 87.4 (P=0.80), respectively; average Disability of the Arm, Shoulder, and Hand scores were 17.9 and 14.7 (P=0.47), and average final flexion/extension arcs were 119.4° and 118.7° (P=0.48). Revision rates were 4.07% and 6.56%, while complication rates were 19.65% and 20.08% in the respective monopolar and bipolar patients. These increased relative risks associated with bipolar implants were not significant.

CONCLUSIONS

Radial head implant polarity does not appear to affect functional outcomes. While bipolar prosthetic design may increase the risks of revision and complications, the increases were not significant. Level of evidence: IV.

Automated Determination of Morphometric Parameters of the Human Radius Based on the Results of Its Computed Tomography

A fundamentally new software method for automated measurement of morphometric parameters of computed tomographic image of the human radius has been designed. The parameters obtained by manual morphometry of computed tomograms using the RadiAnt DICOM Viewer software were compared with the results of the software product developed by us. The relative error in the measurement of morphometric parameters was about 10%. In the future, the presented software method of automated determination of morphometric parameters of the bone will enable modeling of individual prosthesis of the head of the radius based on the results of computed tomograms with consideration of the structural features of the human radius.

Radial head replacement with the 3D-printed patient-specific titanium prosthesis: Preliminary results of a multi-centric prospective study

PURPOSE

To report preliminary clinical results and safety of 3D-printed patient-specific titanium radial head (RH) prosthesis in treatment of the irreparable RH fractures.

MATERIAL AND METHODS

This multi-centric prospective study included 10 patients (6 men and four women, mean age 41 years (range, 25-64 years)). Three cases were classified as Mason type III and 7 cases as type IV. Patients were assessed preoperatively, intraoperatively, and at 1, 6, 12, 24, 36, and 48 weeks postoperatively. Range of motion (ROM), visual analog scale (VAS) score, Disabilities of the Arm, Shoulder and Hand (DASH) score, Mayo Elbow Performance Score (MEPS), radiology imaging, and laboratory blood and urine testing were evaluated.

RESULTS

The prostheses were implanted utilizing cemented stems in 5 patients and cementless stems in 5 patients. Intraoperatively, well congruency of a prosthesis with capitellum and radial notch of ulna was observed in all cases. All patients had improvement of ROM, VAS score, DASH score, and MEPS during the postoperative follow-ups. At the final follow-up, mean elbow extension was 6.5° (range, 0°-30°), flexion 145° (range, 125°-150°), supination 79° (range, 70°-80°), and pronation 73.5° (range, 45°-80°). Mean VAS score was 0.3 (range, 0-3), DASH score was 12.35 (range, 1.7-23.3), and MEPS was 99.5 (range, 95-100). Postoperative radiographs demonstrated heterotopic ossification in 2 cases, periprosthetic radiolucency in 2 cases, and proximal radial neck resorption in 2 cases. No one had the evidence of capitellar erosion, implant failure, malpositioning, overstuffing, or symptomatic stem loosening. There was no significant alteration of laboratory results or adverse events related to the 3D-printed prosthesis implantation.

CONCLUSION

The preliminary results demonstrated that implantation of the 3D-printed patient-specific titanium RH prosthesis is safe and may be a potential treatment option for irreparable RH fracture.

Variation in radial head fracture treatment recommendations in terrible triad injuries is not influenced by viewing two-dimensional computed tomography

BACKGROUND

We analyzed association between viewing two-dimensional computed tomography (2D CT) images in addition to radiographs with radial head treatment recommendations after accounting for patient and surgeon factors in a survey-based experiment.

METHODS

One hundred and fifty-four surgeons reviewed 15 patient scenarios with terrible triad fracture dislocations of the elbow. Surgeons were randomized to view either radiographs only or radiographs and 2D CT images. The scenarios randomized patient age, hand dominance, and occupation. For each scenario, surgeons were asked if they would recommend fixation or arthroplasty of the radial head. Multi-level logistic regression analysis identified variables associated with radial head treatment recommendations.

RESULTS

Reviewing 2D CT images in addition to radiographs had no statistical association with treatment recommendations. A higher likelihood of recommending prosthetic arthroplasty was associated with older patient age, patient occupation not requiring manual labor, surgeon practice location in the United States, practicing for five years or less, and the subspecialties "trauma" and "shoulder and elbow."

CONCLUSIONS

The results of this study suggest that in terrible triad injuries, the imaging appearance of radial head fractures has no measurable influence on treatment recommendations. Personal surgeon factors and patient demographic characteristics may have a larger role in surgical decision making. Level of evidence: Level III, therapeutic case-control 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.

Patient and Surgeon Factors Associated With Prosthetic Replacement Rather Than With Open Reduction and Internal Fixation of a Radial Head Fracture

Background: The decision between radial head arthroplasty and open reduction internal fixation in the context of a terrible triad elbow fracture-dislocation is debated. This study investigated both surgeon and patient factors associated with surgeons' recommendations to use arthroplasty. Methods: One hundred fifty-two surgeon members of the Science of Variation Group participated. Surgeons were asked to complete an online survey that included surgeon demographics and 16 patient scenarios. The patient scenarios were randomized using 2 patient variables and 2 anatomical variables. Multilevel logistic mixed regression analysis was performed to identify surgeon and patient variables associated with recommendations for radial head arthroplasty. Results: We found that radial head replacement was recommended in 38% of the scenarios. Scenarios with older patients, with fractures of the whole head, and those involving 3 fracture fragments were independently associated with radial head replacement. Conclusion: We found that most surgeons recommended radial head fracture fixation rather than arthroplasty. Surgeons were more likely to recommend fixation for younger patients with partial articular fractures or with fractures with 3 or fewer fracture fragments. It seems that surgeons are uneasy about using a prosthesis in a young active patient.

The Unsalvageable Radial Head in Patients Aged 30 Years and Younger

PURPOSE

Concern exists regarding the use of radial head arthroplasty (RHA) in younger patients. This study assessed clinical, functional, and radiographic outcomes of RHA in patients aged 30 years and younger.

METHODS

A retrospective review identified 26 elbows that underwent a smooth stem modular RHA in patients aged 30 years and younger at a median follow-up of 3.3 years clinically and 2.9 years radiographically. The mean age was 24 ± 5 years. Indications were acute trauma in 13 patients and chronic pathologies in the remaining 13, and these 2 groups were evaluated separately. Patients underwent clinical, functional, and radiographic evaluation.

RESULTS

Average arc of motion was 137° ± 16° in the cohort with acute trauma and 120° ± 24° in the cohort with chronic pathologies. Mean Patient-Rated Elbow Evaluation scores were 23 ± 18 (acute) and 31 ± 19 (chronic). Mean Quick Disabilities of the Arm, Shoulder, and Hand scores were 18 ± 15 (acute) and 23 ± 20 (chronic). Average Mayo Elbow Performance Index scores were 90 ± 9 (acute) and 80 ± 13 (chronic). Severe capitellar erosion was present in 1 patient (4%) in the cohort with chronic pathologies. Radiographic stem lucency was seen in all cases with 10 of these (38%) graded as severe. Moderate-to-severe ulnohumeral arthritis developed in 4 patients (15%), 3 of whom were in the chronic reconstruction group. Two patients (8%) required reoperation, 1 for persistent instability and 1 for stiffness, both in the cohort with chronic pathologies.

CONCLUSIONS

For acute trauma and challenging chronic conditions involving the radial head in patients aged 30 years and younger, a smooth stem modular RHA is an option. Although reoperation rates based on this series are low, osteoarthritis is common when used for posttraumatic conditions and severe radiographic stem lucency was seen in greater than one-third of patients. These concerning features warrant close follow-up, and further long-term outcomes are needed.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Correlations Between Radial Head Diameters and Humeral Articular Dimensions: Bilateral MRI Morphometric Analysis on 39 Healthy Subjects

PURPOSE

Choosing the correct size of head component in radial head arthroplasty is often challenging, particularly in comminuted fractures, deformities, and revision surgery. The main aim of this study was to investigate possible correlations between radial head diameters and the morphometric parameters of the articular distal humerus in order to find mathematical equations that may be used to infer radial head dimensions indirectly.

METHODS

We performed bilateral elbow magnetic resonance imaging on 39 healthy young subjects, comprising 19 women and 20 men, with a mean age of 28 years (range, 21-32 years). The following measurements, which included cartilage thickness, were calculated on the axial plane: maximum (Dmax) and minimum (Dmin) radial head diameters, capitellum width, capitellum to lateral trochlear ridge width (CAP-TROCHridge), humeral articular width (HUMwidth), capitellum radius of curvature, and lateral, medial, and total trochlear width. The anteroposterior diameters of the capitellum, trochlear sulci, and lateral and medial trochlear ridges were measured on the sagittal plane.

RESULTS

CAP-TROCHridge and HUMwidth were found to be the parameters most strongly correlated with the radial head diameters. Four mathematical equations that allowed Dmax and Dmin to be calculated with an average residual error less than 1 mm, were obtained. The intraclass coefficient was greater than 0.95 for all the measurements.

CONCLUSIONS

Radial head diameters can be accurately inferred from 2 humeral dimensions by magnetic resonance imaging. The HUMwidth, which is not influenced by cartilage thickness, may be useful for planning with preoperative imaging because it can also be calculated by computed tomography scan, whereas CAP-TROCHridge, which is influenced by cartilage thickness, might be useful for direct intraoperative measurement.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

The Radial Floating Cup radial head prosthesis to treat radial head fractures: functional and radiographic results after more than 12 years of mean follow-up

INTRODUCTION

This study was performed to evaluate the long-term clinical and radiographic results of patients presenting with a radial head fracture who were treated surgically with a Judet Radial Floating Cup 2 (RFC 2) radial head prosthesis.

MATERIALS AND METHODS

This was a retrospective, monocentric, observational, multi-operator, and continuous study performed between July 1997 and June 2009 on the treatment of radial head fracture using an RFC 2 radial head prosthesis. The primary efficacy endpoint was the functional status of the operated elbow, evaluated using the Disability of Arm-Shoulder-Hand (Quick-DASH) score and the Mayo Elbow Performance Index (MEPI). The secondary endpoints were mobility and stability of the operated elbow, residual pain and grip strength, nature and rate of complications, as well as possible radiographic abnormalities during follow-up.

RESULTS

Twenty-two patients were treated with the RFC 2 for radial head fractures over the study period. Three (13.6%) were lost to follow-up, including one death. Of the remaining 19 patients, three RFCs had to be removed (15.8%). The final analysis involved 16 patients. The mean follow-up was 144 months (range 109-225 months; standard deviation [SD] = 49.9 months) or 12 years. The average Quick-DASH score was 23.01/100 (range 0-50; SD = 7.8) and three cases were rated as having "excellent" results according to the MEPI (18.7%), nine cases were rated as having "good" results in (56.2%), and four cases were rated as having "average" results (25%). The average mobility values were: 132° of flexion (range 120°-150°; SD = 11), 14.5° of extension deficit (range 0°-40°; SD = 5), 84.4° of pronation (range 20°-90°; SD = 8°), and 67.7° of supination (range 25°-85°; SD = 10). All patients had a stable elbow. The average grip strength on the affected side thus corresponded to 79% (range 44-100%; SD = 8.3%) of the grip strength on the healthy side. Four patients (25%) developed complications: three cases of algodystrophic syndrome (18.7%) and one case of early dislocation (6.2%). Radiographic evaluation revealed that there was a periprosthetic radio-lucencies in eight patients (50%), periarticular ossifications in 12 patients (75%), and lysis of the capitulum in two patients. There was no significant difference in MEPI ratings between patients with and without a periprosthetic radio-lucencies (P = 0.8018).

CONCLUSIONS

Our results indicated that using the RFC 2 prosthesis to surgically treat radial head fractures provides good long-term functional results, including satisfactory mobility and stability.

Midterm outcomes of 146 EVOLVE Proline modular radial head prostheses: a systematic review

INTRODUCTION

The EVOLVE implant (Wright Medical Technology, Arlington, TN, USA) is a modular loose-fitting radial head prosthesis. The primary objective was to synthesize all available literature investigating the midterm clinical outcomes of the EVOLVE implant.

MATERIALS AND METHODS

An electronic literature search in Pubmed/Medline, Scopus, EMBASE, and Cochrane library was performed querying for studies published in 2000-2017. Articles describing clinical and radiographical outcomes as well as reoperation were included. Outcomes of interest included range of motion, Mayo Elbow Performance Score, Disabilities of the Arm Shoulder and Hand, radiographic outcome, and reason for reoperation.

RESULTS

A total of five articles consisting of 146 patients with EVOLVE implants were included. Mean patient age was 57.4 years (range 22-84), and 43.8% were males (n = 64). Mean follow-up was 4.8 years (range 1-14). Mean Mayo Elbow Performance Score and Disabilities of the Arm Shoulder and Hand score were 87.6 (range 30-100) and 18.9 (range 0-82), respectively. Midterm clinical results were good or excellent (Mayo Elbow Performance Score > 74) in 94 patients. Reoperation was observed in 12 patients, with implant revision required in 2 patients. The primary reason for reoperation was persistent stiffness (n = 9).

CONCLUSION

Midterm outcomes of EVOLVE radial head prosthesis are satisfactory, and associated complication rates are low. Loose-fit implant method appears to be a reliable approach to avoid failure of radial head prosthesis by painful loosening.

Epidemiology and Treatment of Radial Head Fractures: A Database Analysis of Over 70,000 Inpatient Cases

PURPOSE

We aimed to study the epidemiology of radial head fractures within a single national registry database while analyzing trends in available treatments.

METHODS

A retrospective analysis of data from 2007 to 2016 provided by a national inpatient database registry was performed using the International Classification of Diseases code for radial head fractures and associated German Procedure Classification (OPS) codes. All surgical interventions were evaluated according to fracture type, patient sex and age, and distribution differences over the last decade to detect changes in the treatment trends. The number of major revision procedures was identified and the revision burden for each procedure calculated.

RESULTS

Overall, 70,118 radial head fractures were included, with the annual number rising over 20% during this period. Women were significantly older than men (peak incidence, 55-64 years vs 30-39 years) and more frequently injured (women-to-men, 1.3:1). Surgical interventions increased during the study period, with locking plate fixation of comminuted fractures and radial head arthroplasty (RHA) becoming increasingly performed while radial head resections decreased. The revision burden differed significantly between the fixation techniques, with an increased occurrence of RHA revision procedures more recently.

CONCLUSIONS

The data show a higher number and incidence of surgical procedures, especially for comminuted radial head fractures over the study period. Open reduction and internal fixation remains the most frequently used option, with the use of new fixation devices (eg, locking plates) increasing. The use of RHA more than doubled over the past 10 years while the number of radial head resections decreased.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Overlengthening of the radial column in radial head replacement: a review of the literature and presentation of a classification system

BACKGROUND

Radial head arthroplasty is a common procedure in elbow surgery. It has been shown to be of benefit for the patients, but there also are relevant complications that should be prevented if possible. One significant complication is overlengthening of the radial head prosthesis. In overlengthening, the head of the prosthesis overextends the physiological level of the native radial head and leads to overcompression in the radiohumeral joint. Rapid erosion and arthritic changes may then impede the clinical outcome. The incidence of overlengthening is not precisely known, but estimations range to up to 20% of all implanted prostheses.

METHODS

The present review discusses the available body of literature on overlengthening and lines out a classification system that may be used to guide treatment algorithms. The classification is based on the personal experiences of the author during their clinical practice.

RESULTS

In low-grade overlengthening (type I) conservative treatment can be an option. In Types II-IV usually revision surgery is needed. Depending on the state of the capitulum and joint stability, it is possible re-implant a prosthesis, or rely on implant removal alone.

DISCUSSION

The present review aimed at shedding light into overlengthening as a complication radial head replacement and to help identify and treat it.

In vitro comparison of wear characteristics of PyroCarbon and metal on bone: Shoulder hemiarthroplasty

BACKGROUND

There are concerns regarding glenoid erosion with metal shoulder hemiarthroplasty. PyroCarbon may offer an alternative because of favorable wear characteristics and preservation of the glenoid. The purpose of this study was to assess in vitro bone wear characteristics of PyroCarbon relative to cobalt chromium alloy hemiarthroplasty in a shoulder wear simulator.

METHODS

Wear of PyroCarbon and cobalt chromium prostheses articulating with bone were characterized by means of bone wear penetration rate, changes to surface roughness, and wear particle analysis.

RESULTS

PyroCarbon prostheses produced significantly less damage to bone and were less damaged by the bone than cobalt chromium prostheses. Cobalt chromium testing was halted at approximately 320,000 cycles because the bone was consumed. Wear testing of PyroCarbon specimens continued through five million cycles. Linearized bone penetration rate, bone volume loss rate, and surface roughness for cobalt chromium test specimens were 30 times greater than for PyroCarbon.

CONCLUSIONS

Results demonstrate significantly less damage to bone in simulated shoulder function testing for PyroCarbon hemiarthroplasty implants relative to conventional cobalt chromium implants. Our study supports use of PyroCarbon in humeral head hemiarthroplasty as a viable alternative to conventional metal hemiarthroplasty. Further investigation of PyroCarbon performance in clinical settings is warranted.

Management of the failed radial head arthroplasty

Primary radial head arthroplasty (RHA) produces good or excellent results in approximately 85% of patients. However, complications are not uncommon and have been described in up to 23% of cases.

The number of RHA is increasing, and consequently the absolute number of complications is expected to rise as well. The decision on whether to revise or remove the prosthesis seems more likely to depend on the preference of the surgeon or the hospital, rather than on objectifying problems with the prosthesis.

The current article presents an algorithm for the work-up and treatment of most complications that can occur following RHA.

Five subgroups of problems were identified: osteoarthritis, stiffness, instability, infection and implant-related issues.

In short, the preferred treatment depends mainly on the chondral condition and stability of the elbow joint.

Cite this article: EFORT Open Rev 2020;5:398-407. DOI: 10.1302/2058-5241.5.190055

Radial head fractures

The shape and size of the radial head is highly variable but correlates to the contralateral side. The radial head is a secondary stabilizer to valgus stress and provides lateral stability. The modified Mason-Hotchkiss classification is the most commonly used and describes three types, depending on the number of fragments and their displacement. Type 1 fractures are typically treated conservatively. Surgical reduction and fixation are recommended for type 2 fractures, if there is a mechanical block to motion. This can be done arthroscopically or open. Controversy exists for two-part fractures with >2 mm and <5 mm displacement, without a mechanical bloc as good results have been published with conservative treatment. Type 3 fractures are often treated with radial head replacement. Although radial head resection is also an option as long-term results have been shown to be favourable. Radial head arthroplasty is recommended in type 3 fractures with ligamentous injury or proximal ulna fractures. Failure of primary radial head replacement may be due to several factors. Identification of the cause of failure is essential. Failed radial head arthroplasty can be treated by implant removal alone, interposition arthroplasty, revision radial head replacement either as a single stage or two-stage procedure.

Radial Head Arthroplasty, Excision and Osteosynthesis in Complex Elbow Fracture-Dislocations in Young Adults: What is Preferred?

OBJECTIVE

Complex elbow fractures are common injuries in young adults. Results in recent studies with various operative treatment protocols are equivocal. We compared the results of radial head arthroplasty, excision with osteosynthesis in such injuries at two follow-ups 1 year apart.

METHODS

Thirty-five patients of complex elbow fracture-dislocations including, posterior/anterior olecranon dislocation of elbow, terrible triad injury, anteromedial facet of coronoid fracture, Type IV Monteggia fracture-dislocation and unclassified elbow dislocation were enrolled. They were managed operatively by standardized protocol similar to McKee et al. radial head reconstruction with miniplates, lag screws or non-operative treatment for undisplaced fractures. Arthroplasty of radial head with cemented prosthesis + LCL repair with suture anchor/transosseous tunnel was done. Coronoid and olecranon fixation was always performed. Patients were evaluated as follows: Q-DASH score, MEPI, pain according to VAS, range of motion, complications and radiographic findings and fracture union, and elbow instability.

RESULTS

The mean length of follow-up among the patients was 18 months. There were statistically significant differences between the DASH score/MEPS between radial head excision and replacement/reconstruction. Instability was significantly reduced in those with LCL reconstruction. Excising the comminuted radial head without replacement had the worst outcome. Best PROM was reported in patients with osteosynthesis.

CONCLUSION

Provided a standard protocol is applied, radial head osteosynthesis has preferable outcomes in terms of patient-related outcomes as compared to arthroplasty, although not statistically significant. Radial head excision though has acceptable outcomes but there is a restriction of movements especially flexion-extension. Acceptable rate of complications major or minor warrants need of secondary surgical procedures or a staged treatment.

Open Reduction and Internal Fixation Versus Radial Head Arthroplasty for Mason III Radial Head Fractures: Appraising the Current Literature Evidence

Fractures of the radial head are common and account for one-third of elbow fractures. Management has evolved over the past few decades as have the techniques and implants used to treat them. However, no standardized treatment protocol exists because of the complexity with which these fractures may present. The complex, unstable, displaced, and multi-fragmentary fractures, also known as Mason type III fractures, remain one of the most challenging fractures to treat, especially if associated with other elbow injuries. There are various surgical treatment options available, including open reduction and internal fixation or radial head arthroplasty. The purpose of this study was to systematically review the current literature that assessed open reduction and internal fixation compare to radial head replacement to identify the best surgical treatment protocol for the management of Mason type III radial head fracture. All published clinical trials claiming to evaluate or cited elsewhere as being authoritative regarding the surgical treatment of radial head fractures were identified and evaluated. Studies in foreign languages (not in English) were excluded. Based on two randomized controlled trials, this review showed some weak evidence that arthroplasty results in better functional elbow outcomes and lower complication rates as compared to open reduction and internal fixation. There is a scarcity of good quality comparative studies and multicenter randomized controlled trials should be considered.

Elbow Biomechanics, Radiocapitellar Joint Pressure, and Interosseous Membrane Strain Before and After Radial Head Arthroplasty

Complex radial head fracture and elbow instability can be treated with radial head arthroplasty. Good clinical results have been described after this surgical treatment. However, the revision and complication rate reported in the literature is concerning. This might be due to altered kinematics after radial head arthroplasty. Eight human native elbows were examined with dynamic radiostereometric analysis and compared with a radial head arthroplasty. Translations of the radial head in the x-, y-, and z-directions relative to the humerus and the ulna were measured. The radiocapitellar joint pressure was measured using a pressure sensor. The tension within the interosseous membrane was measured using a custom-made strain gauge. After radial head arthroplasty, the radial head was displaced approximately 1.8  mm medially and 1.4  mm distally at the starting point. During unloaded flexion motion the difference in all translations between the native radial head and the radial head arthroplasty was less than 1 mm (95% confidence interval [CI]  ±  0.5 mm) (p = 0.001). With loading the difference was less than 1.5  mm (95% CI  ± 1.5  mm) (p = 0.001). The mean difference in radiocapitellar joint contact pressure was less than 0.30 MPa (95% CI ± 0.40 MPa) (p = 0.001) during unloaded flexion motion. There were only submillimetre kinematic changes and small changes in joint pressure and interosseous membrane tension after the insertion of a radial head arthroplasty in an experimental setting. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:510-522, 2020.

Why does radial head arthroplasty fail today? A systematic review of recent literature

Since the introduction of the radial head prosthesis (RHP) in 1941, many designs have been introduced. It is not clear whether prosthesis design parameters are related to early failure. The aim of this systematic review is to report on failure modes and to explore the association between implant design and early failure.A search was conducted to identify studies reporting on failed primary RHP. The results are clustered per type of RHP based on: material, fixation technique, modularity, and polarity. Chi-square tests are used to compare reasons for failure between the groups.Thirty-four articles are included involving 152 failed radial head arthroplasties (RHAs) in 152 patients. Eighteen different types of RHPs have been used.The most frequent reasons for revision surgery after RHA are (aseptic) loosening (30%), elbow stiffness (20%) and/or persisting pain (17%). Failure occurs after an average of 34 months (range, 0-348 months; median, 14 months).Press-fit prostheses fail at a higher ratio because of symptomatic loosening than intentionally loose-fit prostheses and prostheses that are fixed with an expandable stem (p < 0.01).Because of the many different types of RHP used to date and the limited numbers and evidence on early failure of RHA, the current data provide no evidence for a specific RHP design. Cite this article: EFORT Open Rev 2019;4:659-667. DOI: 10.1302/2058-5241.4.180099.

Correlation between radiographic findings and clinical failure in monopolar radial head replacement

INTRODUCTION

The purpose of this study is to analyze the mid-term outcomes of a modular monopolar type of radial head arthroplasty in the treatment of complex fractures associated with acute elbow joint instability. We postulated that radiographic changes are related to the development of clinical complications.

MATERIALS AND METHODS

We evaluated at last follow-up 26 radial head arthroplasties in 26 consecutive patients who were followed for at least one and a half year. All patients had suffered radial head fractures (Mason III) in the context of unstable elbow injuries. Definitive treatment of the radial fracture was performed with modular and monopolar prosthesis which was inserted as a press fit. All patients were evaluated preoperatively and postoperatively. The evaluation included a clinical examination and a protocolized imaging study (standard X-Rays and CT) of the elbow. We analyzed the incidence of: heterotopic ossifications, secondary radiocapitellar joint osteoarthritis, hardware loosening, hardware disengagement, and joint infection. Diagnosis of clinical failure of the implant was defined as the time to the second surgery due to major complications related to the prosthesis, such as persistent lateral side pain or elbow stiffness and any kind of implant instability or dislocation.

RESULTS

The implant-specific reoperation rate was 15% (four reoperations). The need for the second surgery was statistically associated with heterotopic ossifications, radiocapitellar osteoarthritis and cortical resorption around radial neck (p = 0.054, p = 0.033, and p = 0.019, respectively), being periprosthetic osteolysis the most likely factor related to failure, and radial pain the main symptom leading to surgical revision.

CONCLUSIONS

Our study shows a positive association between radiographic findings and patient symptoms for postoperative complications after radial head arthroplasty. Failed radial head replacements may lead to reoperation mainly due to pain, and this can be distinguished from other causes of pain in elbow region based on its radial location. Radiological loosening was prevalent in this group of failed replacement.

Preserving the radial head in comminuted Mason type III fractures without fixation to the radial shaft: a mid-term clinical and radiographic follow-up study

BACKGROUND

The treatment of multifragment Mason type III fractures is challenging. Open reduction-internal fixation (ORIF), radial head arthroplasty, and in some cases, even radial head resection are the current options; however, each of these treatment methods is associated with characteristic benefits and complications. We present our experience with a radial head salvage procedure in comminuted radial head fractures irrespective of concomitant injuries, which are not accompanied by typical ORIF-related complications.

METHODS

The first group comprised 29 patients with multifragment Mason type III fractures treated surgically with biological radial head spacers (group S). The fragments were reduced and fixated in an extracorporeal manner, and the reconstructed radial head was placed in its anatomic position without fixation to the shaft. The second group comprised 12 patients treated with conventional ORIF using mini-fragment plates (group P).

RESULTS

Thirty patients were enrolled to undergo clinical and radiographic follow-up at an average of 76 months (range, 12-152 months). In group S, nonunion at the head-neck junction developed in 70% of the cases; however, the overall Mayo Elbow Performance Index averaged 94.8, which was superior to the average Mayo Elbow Performance Index of 83.1 in group P. Radiographic evaluation showed development of osteoarthritic changes in 75% of patients in group S and 62.5% in group P. None of the patients had wrist-joint pain.

CONCLUSIONS

Preserving the native radial head in comminuted Mason type III fractures without fixation to the radial shaft is a reliable option. Excellent functional results can be expected; however, the development of osteoarthritis cannot be impeded.

Metallic Press-fit Radial Head Replacement for Radial Head Fractures

This study evaluated the clinical and radiographic results of patients who sustained nonreconstructible radial head fractures that subsequently were treated with a metallic press-fit radial head prosthesis (RHP). Nine patients with comminuted radial head fractures were treated with a metallic press-fit RHP; mean follow-up was 38.7 months. The radial head fracture was acute in 6 patients (group A) and chronic in 3 patients (group B). Functional evaluation was assessed using the Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) Questionnaire. Radiographs were assessed for loosening, radiocapitellar alignment, osteolysis of the radial neck, lucency, periarticular ossifications, and ulnohumeral degeneration. Average flexion and flexion contracture were 133° and 5°, respectively. Average supination and pronation angles were 70° and 73°, respectively. Mean MEPS was 90 (range, 70-100), and elbow performance was excellent in 4 patients, good in 4 patients, and fair in 1 patient. Mean DASH score was 21.9 (range, 0-61). Flexion contracture, forearm rotation arc, and MEPS score were better and the complication rate was lower in group A compared with group B. Centering of the stem was observed on both anteroposterior and lateral radiographs in 6 patients. Lucent lines around the prostheses, stress shielding under the neck of the radius, and ectopic ossification occurred in 5 patients. Three patients had osteoarthritis. Elbow stiffness and ulnar impaction syndrome occurred in 2 patients but only after placement of a secondary RHP. Satisfactory outcomes were obtained using a metallic press-fit RHP for nonreconstructible radial head fractures. [Orthopedics. 2019; 42(6):e545-e551.].

High Risk of Further Surgery After Radial Head Replacement for Unstable Fractures: Longer-term Outcomes at a Minimum Follow-up of 8 Years

BACKGROUND

The evidence for treating acute, unreconstructable radial head fractures in unstable elbows with radial head replacement predominantly consists of short- to mid-term follow-up studies with a heterogenous mix of implants and operative techniques. Data on longer-term patient-reported outcomes after radial head replacement is lacking.

QUESTIONS/PURPOSES

(1) What proportion of patients undergo revision or implant removal after radial head replacement? (2) At a minimum of 8 years follow-up, what are the patient-reported outcomes (QuickDASH, Oxford Elbow Score, and EuroQol-5D)? (3) What factors are associated with a superior long-term patient-reported outcome, according to the QuickDASH?

METHODS

Between September 1994 and September 2010, we surgically treated 157 patients for acute radial head fractures. We excluded patients where the radial head was excised (n = 21), internally fixed (n = 15), or replaced as a secondary procedure after failed internal fixation (n = 2). A total of 119 patients who underwent radial head replacement surgery for an acute unreconstructable fracture were included, with a mean age of 50 years (range 15 to 93 ± 19 years), and 53% of patients (63) were women. All but two implants were uncemented, loose-fitting, monopolar prostheses, of which 86% (102) were metallic and 14% (17) were silastic. Implants were only cemented if they appeared unstable within the proximal radius. Silastic implants were used in the earlier series and replaced by metallic implants starting in 2000. We reviewed electronic records to document postoperative complications and prosthesis revision and removal. A member of the local research team (THC, CDC) who was not previously involved in patient care contacted patients to confirm complications, reoperations and to obtain long-term patient-reported outcomes scores. Nineteen patients had died at the point of outcome score collection. Of the remaining 100 patients, 80 were contacted (67% of total cohort), at a median of 11 years (range 8 to 24 years) after injury. The primary outcome measure was the QuickDASH score.

RESULTS

Of 119 patients, 25% (30) underwent reoperation, with three patients undergoing revision and 27 patients undergoing prosthesis removal at a median of 7 months (range 0 to 125 months). Twenty-one of 30 procedures (70%) occurred within 1 year after implantation. Kaplan-Meier survivorship analysis demonstrated a cumulative implant survival rate of 71%. In the 80 patients contacted, the mean QuickDASH score was 13 ± 14, the mean Oxford Elbow Score was 43 ± 6, and the median EuroQol-5D score was 0.8 (-0.3 to 1.0). After controlling for covariates, we found that prothesis revision or removal (p = 0.466) and prosthesis type (p = 0.553) were not associated with patient-reported outcome, according to the QuickDASH.

CONCLUSIONS

The management of acute unreconstructable fractures of the radial head in unstable elbow injuries with radial head replacement has a high risk of reoperation. Patients must be counselled regarding this risk of secondary intervention, of which the peak risk appears to be within 1 year after implantation. Despite this, patients report low disability according to the QuickDASH at a minimum follow-up of 8 years.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Midterm outcome of partial radial head replacement with a contoured iliac crest bone graft in complex elbow dislocation

PURPOSE

To report the midterm outcome of a novel reconstructive technique using a contoured iliac crest bone graft for partial radial head replacement in the treatment of complex elbow dislocation.

MATERIAL AND METHODS

Between January 2008 and December 2013, 10 patients (5 women, 5 men; mean age, 43.8 years; mean follow-up duration, 65.9 months) with complex elbow dislocation who underwent the partial radial head replacement with the contoured bone graft were included in the study. The irreparable radial head defects averaged 49% of the articular surface (range, 36-60%). The fracture involved the entire head in four patients and partial head in six patients.

RESULTS

At the final follow-up, the mean elbow extension was 8°, flexion 143°, supination 76.5°, and pronation 73°. The mean Mayo elbow performance index was 93.2 points and the Broberg-Morrey functional rating score was 94.1 points, with seven excellent cases, two good cases, and one fair case. Radiographic union was achieved in all but one, at an average time of 6.89 weeks (range, 6-10 weeks). The final radiographs demonstrated no evidence of degenerative change in eight patients, mild arthritis in one patient, and moderate arthritis in one patient.

CONCLUSION

This technique is a viable option in the treatment of the large radial head defect in complex elbow dislocation when more than 40% of the original head is still available for incorporation.

Validation of a Simple Overlay Device to Assess Radial Head Implant Length

PURPOSE

A simple overlay device (SOD) was developed to measure radial head implant length. The purpose of this study was to determine the accuracy and reliability of this device for measuring experimental radial head implant length.

METHODS

Five fresh frozen cadavers were implanted with sequentially longer implants, adjusted by neck length (0, 2, 4, and 8 mm). Fluoroscopic images were obtained in 4 forearm positions: anteroposterior in supination in full extension, anteroposterior in pronation in full extension, supinated in 45° of flexion, and neutral in 45° of flexion. The SOD measurements (made by 2 observers) were compared with the native original radial head (control) to assess implant length. In addition, gapping of the ulnohumeral joint space was measured for comparison purposes.

RESULTS

The measured radial head and neck lengths for the specimens were 33, 39, 31, 34, and 42 mm. The difference between the actual radial head and neck lengths and those measured with the SOD template averaged less than 2 mm for all 4 collar sizes, except in 1 measurement in which the bicipital tuberosity could not be visualized. The median intraclass correlation coefficients for observer 1 compared with the SOD were 0.94 to 0.99. The median intraclass correlation coefficients between observers were 0.88 to 0.95. For both observers, elbow position, collar height, and the 2 variables combined did not significantly affect the SOD values. The other method that was evaluated, that of measurement of the ulnohumeral joint space, had higher interobserver variability versus the SOD, and allowed detection of lengthening of over 4 mm.

CONCLUSIONS

The SOD is a reliable method for simply assessing radial head length with radiographs and can accurately detect 2 mm or more of proximal radial lengthening.

CLINICAL RELEVANCE

The SOD is a simple and accurate method that can help to optimize radial head sizing.

Complications after radial head arthroplasty: a comparison between short-stemmed bipolar and monopolar long-stemmed osteointegrative rigidly fixed prostheses

INTRODUCTION

To date, only a few studies have compared radial head prostheses (RHP) and their different anchoring principles. The aim of this study was to characterize concomitant injuries, necessary adjuvant procedures, complications, and radiological findings after implantation of two different types of RHP.

METHODS

Sixty-six patients with radial head fractures were treated with MoPyC (Tornier/France, 50 mm stem, monopolar) or SBI rHead prostheses (Small Bone Innovations/USA, 22-mm stem, bipolar) and followed up over 42 months (16-64 months). Primary objective was the detection of different loosening and explantation rates. In addition to the revision rate and the reasons for revision, we also used radiological findings to assess the dynamics of lysis phenomena.

RESULTS

Thirty-five patients (mean age 48 years; 22-73 years) were treated with the MoPyC, and 31 patients (mean age 47 years, 19-69 years) with the rHead prosthesis. Of these, 98% had a Mason 3 or 4 type of radial head fracture, and 94% showed concomitant injuries, which were addressed in 89% of cases by adjuvant procedures. The surgical revision rate was 20% (rHead 23%; MoPyC 18%). Significantly more of the rHead prostheses had to be explanted compared to MoPyC prostheses because of painful loosening (16% vs. 3%; p = 0.029). Predictors of subsequent loosening were significant radiolucent lines in the RHP over the first six months and an increase in width by two and a half times within the first 50 days after implantation.

CONCLUSION

Complex radial head fractures are frequent and difficult to treat. The monopolar long-stemmed prosthesis showed significantly lower rates of painful loosening and explanation rates than the bipolar short-stemmed prosthesis.

Pyrocarbon arthroplasty in acute unreconstructable radial head fractures: mid-term to long term results

BACKGROUND

The aim of this study is to describe the mid-term radiological findings appearing in patients with a pyrocarbon radial head prosthesis, and to correlate them to patient symptoms.

MATERIALS AND METHODS

We review 18 patients who underwent radial head implantation of the MoPyC prosthesis between 2004 and 2015, due to unreconstructible radial head fractures. The clinical outcomes were assessed with Mayo Elbow Performance Score (MEPS). Range of motion, pain, and elbow radiological assessments were recorded. A non-parametric, statistical analysis was carried out to assess the radiological findings with the clinical outcomes.

RESULTS

We have found that after a mean follow-up of 6.5 years (2-11 years), patients have recovered a median flexion arch of 113°, therefore 77% are classed as satisfactory outcomes and the average MEPS score is 89.5. The presence of periprosthetic changes on X-ray is highly frequent-we found radiolucent lines in 38% of cases, radial neck re-absorption in 83%, and arthrosic changes in 78%. However, the differences found when correlating these changes with the clinical results have not been statistically significant (p > 0.05).

CONCLUSIONS

Satisfactory outcomes can be expected midterm when using pyrocarbon prostheses in around 75% of the cases. We consider radial neck re-absorption to be a sign of good stem osteointegration, whereas progressive radiolucencies and loss of the ballooning of the stem legs are signs of bad prognosis in our series.

LEVEL OF EVIDENCE

IV retrospective case series.

Long-term outcomes of modular metal prosthesis replacement in patients with irreparable radial head fractures

BACKGROUND

The purposes of this study were to investigate the long-term outcomes of radial head replacement and to analyze the relationship between functional outcomes and periprosthetic radiolucency.

METHODS

We retrospectively reviewed 32 patients who underwent unilateral radial head replacement between 2004 and 2011. Data on patient characteristics including age, gender, injury complexity, associated trauma, injury chronicity, and number of surgeries were collected and analyzed. Of these patients, 14 had terrible triad injury, 14 valgus-type injuries, 3 Monteggia fracture, and 1 concomitant distal humerus fracture. Clinical survey was performed at 7 to 15 years after replacement surgery. The Mayo Elbow Performance Score (MEPS) and shortened Disabilities of the Arm, Shoulder, and Hand (quickDASH) score were used for functional evaluation. Residual elbow or forearm pain was evaluated using visual analog scale (VAS). Radiographs were reviewed by orthopedic and radiologic specialists, and periprosthetic radiolucency was measured based on the diameter of radial head prosthesis.

RESULTS

The 32 patients returned for follow-up at an average of 8.94 years. None underwent prosthesis revision or removal. MEPS averaged 83.4; good or excellent results were achieved in 26 patients. QuickDASH scores averaged 11.7. Significantly better MEPS (p = 0.023) and quickDASH scores (p = 0.026) were noted when replacement surgery served as the primary surgery instead of late salvage. VAS scores averaged 1.25, with residual pain noted in 24 elbows (75%). Periprosthetic radiolucency was noted in 21 patients (66%) with a mean thickness of 3.53 mm. The difference in functional outcomes was not significant between patients with and without radiolucency, with p values of 0.127 for MEPS and 0.135 for quickDASH scores. Spearman correlation analysis showed low correlation between the measured width of radiolucency and VAS scores (r = 0.143).

CONCLUSION

Sustained, encouraging clinical outcomes were reported in the present study. Although periprosthetic radiolucency did not correlate with functional or pain scores, surgical optimization and meticulous survey were warranted.

Radial head replacement with a bipolar system: an average 10-year follow-up

BACKGROUND

We report the long-term results of a cohort of patients after radial head replacement with a bipolar design and a smooth cementless stem at a mean follow-up of 10.4 years.

METHODS

Of 17 possible patients from a previous minimum 2-year follow-up study, 16 were available for review. Patients were assessed using clinical and radiographic examination and with standardized outcome measures. Range of motion, stability, and radiographic evaluation of implant loosening and joint degeneration were assessed. Comparisons were performed using the Wilcoxon signed rank test for unequal groups.

RESULTS

The average follow-up was 10.5 years (range, 8.5-12 years). The median visual analog scale was 1 (range, 0-5), Minnesota Elbow Performance Index was 93 (range, 70-100), and the Disabilities of the Arm, Shoulder and Hand was 7.5 (range, 0-53). Range of motion was decreased on the operative side compared with the nonoperative side for flexion/extension (P = .005) and pronation/supination (P = .015). Grip strength was decreased on the affected side (P = .045). No patients had elbow instability. Significant arthritic changes developed in 2 patients at the ulnohumeral joint. The median cantilever quotient was 0.4 (range, 0.30-0.50). Osteolysis in zones 1 to 7 was found in all but 2 patients. The median stem radiolucency was 0.5 mm (range, 0.2-0.9 mm). No reoperations occurred since our previous report. Implant survival in this cohort was 97%.

CONCLUSION

Bipolar radial head prosthesis with a smooth cementless stem effectively restores elbow stability and function after comminuted radial head fractures with or without concomitant elbow instability. Our study demonstrates excellent long-term implant survival.

Radial Head Fractures

Background:

Radial head fractures are common elbow injuries in adults and are frequently associated with additional soft tissue and bone injuries.

Methods:

A literature search was performed and the authors’ personal experiences are reported.

Results:

Mason type I fractures are treated non-operatively with splinting and early mobilisation. The management of Mason type II injuries is less clear with evidence supporting both non-operative treatment and internal fixation. The degree of intra-articular displacement and angulation acceptable for non-operative management has yet to be conclusively defined. Similarly the treatment of type III and IV fractures remain controversial. Traditional radial head excision is associated with valgus instability and should be considered only for patients with low functional demands. Comparative studies have shown improved results from internal fixation over excision. Internal fixation should only be attempted when anatomic reduction and initiation of early motion can be achieved. Authors have reported that results from fixation are poorer and complication rates are higher if more than three fragments are present. Radial head arthroplasty aims to reconstruct the native head and is indicated when internal fixation is not feasible and in the presence of complex elbow injuries. Overstuffing of the radiocapitellar joint is a frequent technical fault and has significant adverse effects on elbow biomechanics. Modular design improves the surgeon’s ability to reconstruct the native joint. Two randomised controlled trials have shown improved clinical outcomes and lower complication rate following arthroplasty when compared to internal fixation.

Conclusion:

We have presented details regarding the treatment of various types of radial head fractures - further evidence, however, is still required to provide clarity over the role of these different management strategies.

The Rate of Radial Head Prosthesis Removal or Revision: A Systematic Review and Meta-Analysis

PURPOSE

We conducted a meta-analysis and systematic review with the primary objective to determine the overall incidence of radial head prosthesis removal or revision. Our secondary objectives addressed the incidence of removal or revision based on the type of prosthesis fixation (cemented, uncemented smooth stem, uncemented press-fit), material (metal, Vitallium, titanium, pyrocarbon), and design (short vs long stem and monopolar vs bipolar), and the reasons for prosthetic removal or revision.

METHODS

We included 30 studies with a total of 1,017 patients out of whom 77 prostheses were removed and 45 prostheses were revised.

RESULTS

The pooled rate of radial head prosthesis removal or revision was 10.0% (95% confidence interval, 7.3%-13.6%) with a mean follow-up of 38 months. Subgroup analysis showed that the incidence of removal/revision was lowest with the cemented fixation, longer-stem, Vitallium material, and bipolar prosthesis. More than half of the prostheses were removed/revised for excision of the heterotopic ossification (47%) and for the treatment of stiffness and limitation of motion (42%). Other reasons recorded were pain (19%), loosening (16%), overstuffing (13%), instability (12%), infection (8%), and prosthesis disassembly (4%).

CONCLUSIONS

The current data show that the highest incidence of removal/revision occurred within 2 years after implantation. There was no major difference in the incidence of removal/revision among different designs and materials. Implant removal was often performed as part of a procedure to manage elbow stiffness and heterotopic ossification at the surgeon's preference, not necessarily because the implant was malfunctioning. It appears that most radial head arthroplasties have an acceptable and comparable mid-term longevity; however, it is unclear whether long-term longevity will differ between devices.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

The minimum follow-up required for radial head arthroplasty: a meta-analysis

AIMS

The primary aim of this study was to define the standard minimum follow-up required to produce a reliable estimate of the rate of re-operation after radial head arthroplasty (RHA). The secondary objective was to define the leading reasons for re-operation.

MATERIALS AND METHODS

Four electronic databases, between January 2000 and March 2017 were searched. Articles reporting reasons for re-operation (Group I) and results (Group II) after RHA were included. In Group I, a meta-analysis was performed to obtain the standard minimum follow-up, the mean time to re-operation and the reason for failure. In Group II, the minimum follow-up for each study was compared with the standard minimum follow-up.

RESULTS

A total of 40 studies were analysed: three were Group I and included 80 implants and 37 were Group II and included 1192 implants. In Group I, the mean time to re-operation was 1.37 years (0 to 11.25), the standard minimum follow-up was 3.25 years; painful loosening was the main indication for re-operation. In Group II, 33 Group II articles (89.2%) reported a minimum follow-up of < 3.25 years.

CONCLUSION

The literature does not provide a reliable estimate of the rate of re-operation after RHA. The reproducibility of results would be improved by using a minimum follow-up of three years combined with a consensus of the definition of the reasons for failure after RHA. Cite this article: Bone Joint J 2017;99-B:1561-70.

Radial Head Arthroplasty in the Active Duty Military Service Member With Minimum 2-Year Follow-Up

PURPOSE

Radial head arthroplasty (RHA) is a viable treatment for complex radial head fracture. Whereas elbow stability and function is typically restored at short- to mid-term follow-up, the outcome in higher-demand populations is not well defined. We sought to characterize the functional and occupational outcomes following RHA in an active duty military population with intense upper extremity demands.

METHODS

We retrospectively reviewed the records of all U.S. military service members undergoing primary RHA from 2010 and 2013 with a minimum of 2-year follow-up. Patient-based, injury-related, and surgical variables were extracted from the military-wide electronic medical record. Functional and occupational outcomes including pain, and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire were recorded. The primary outcomes of interest were the rate and level of return to upper extremity activity. Secondary outcome measures included return to duty, complications, and revision surgery.

RESULTS

Nineteen patients were included with average age 31 years and median 37 months' follow-up. Ten were Mason III, 6 were part of a terrible triad injury, and the remainder were fracture-dislocations. At an average follow-up of 3.7 years, 15 patients returned to active military duty, and 9 resumed their regular upper extremity military function. At the time of final follow-up, the average DASH score was 13. Seven patients returned to their usual level of sport and exercise, 6 at a reduced level, and 6 did not resume physical exercises secondary to pain or stiffness. Sixteen adverse outcomes among 14 patients included symptomatic heterotopic ossification (5 of 19) and neurological sequelae (4 of 19). Three elected to have a revision procedure at an average of 13 months for heterotopic ossification or loosening.

CONCLUSIONS

Among active patients with radial head fractures treated with RHA, three-quarters will return to active duty military service, push-ups, and sport; however, half may report an adverse outcome unrelated to the prosthesis and only about half of patients will return to their preinjury level of function.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Retrospective cohort study on radial head replacements comparing results between smooth and porous stem designs

BACKGROUND

When necessary, radial head integrity after a fracture can be re-created by the use of a radial head arthroplasty if the radial head is judged irreparable. The purpose of this study was to compare the clinical and radiographic outcomes of metal modular radial head replacements with a smooth vs. a porous stem.

METHODS

A retrospective cohort study of radial head replacements performed in the first 4 weeks after a trauma in an adult patient at our institution between 2000 and 2014 was completed. Patients were divided into 2 groups: a porous stem group (ExploR; Biomet Orthopedics, Warsaw, IN, USA) and a smooth stem group (EVOLVE; Wright Medical Group, Memphis, TN, USA). Primary outcomes were the Disabilities of the Arm, Shoulder, and Hand and Mayo Elbow Performance Index scores. Secondary outcomes were the visual analog scale score for pain, range of motion, grip strength, and radiographic evaluations.

RESULTS

Of the 80 eligible patients, 57 agreed to participate (porous stem group, 36; smooth stem group, 21). Demographic data were similar between the 2 groups. Average follow-up was 6.3 years. Average Disabilities of the Arm, Shoulder, and Hand and Mayo Elbow Performance Index scores were similar between the 2 groups. Porous implants were more prone to osteolysis (64.3% vs. 23.5%; P = .01) and were associated with a greater loss of elbow flexion (6° vs. 1°; P = .02). The porous stem group showed a tendency toward more overstuffing (24.0% vs. 5.9%; P = .21).

CONCLUSION

Our results reveal that outcomes between smooth and porous stem metal modular radial head implants are equivalent. However, the smooth stem implant may represent the preferred option as it is associated with a lower rate of complications.

A radial head prosthesis appears to be unnecessary in Mason-IV fracture dislocation

Background and purpose - Previous reports on elbow injuries with concomitant comminute radial head fracture are difficult to interpret, since they include an array of different soft-tissue and bony injuries around the elbow. We focused on Mason-IV fracture dislocations of the elbow and retrospectively reviewed 2 treatment options: radial head resection or replacement with a radial head arthroplasty, both in combination with lateral ligament repair. Patients and methods - In Linköping, 18 consecutive patients with Mason-IV fracture dislocation and with a median age of 56 (19-79) years were treated with a radial head arthroplasty. In Malmö, 14 consecutive patients with a median age of 50 (29-70) years were treated for the same injury with radial head resection. With a follow-up of at least 2 years (Linköping: median 58 months; Malmö: median 108 months), the outcome was assessed using the Mayo elbow performance score (MEPS), the Disabilities of Arm, Shoulder, and Hand questionnaire (DASH), range of movement, instability, and plain radiographs. Results - There was no statistically significant difference between the groups regarding MEPS, DASH, or range of motion. The rate of additional surgery was higher in patients treated with arthroplasty. Ulno-humeral osteoarthritis was more pronounced in the group treated with radial head resection, but the follow-up time was longer in these patients. Functional results and range of motion tally well with previous reports on similar injuries. Interpretation - Functional results did not improve by using a press-fit radial head arthroplasty in Mason-IV fracture dislocation of the elbow. Secondary osteoarthritis after resection of the radial head is a concern, but it did not affect the functional outcome during the follow-up time.

Mason type III radial head fractures treated by anatomic radial head arthroplasty: Is this a safe treatment option?

BACKGROUND

Radial head fractures make up approximately 3% of all fractures and they are the most common elbow fracture in adults. Replacement through arthroplasty is the recommended treatment in the context of unstable elbow injury and comminuted radial head fracture. The midterm clinical, functional, and radiographic results in patients treated with anatomic radial head arthroplasty for a Mason type III radial head fracture are presented.

MATERIAL AND METHODS

We performed a retrospective search of our facility's prospective trauma database to identify all skeletally mature patients who were treated by primary radial head replacement or open reduction and internal fixation following an acute radial head fracture. Inclusion criteria were Mason type III fractures and anatomic radial head arthroplasty (RHA). All the patients included were evaluated using a standard postoperative protocol including clinical and radiographic evaluation at 1, 3 and 12 months of follow-up. All the patients were reviewed clinically at an average of 30 months' follow-up.

RESULTS

Forty-one subjects (32 Mason type III and 9 Mason IV fractures) were treated with anatomic RHA (Acumed, Hillsboro, OR, USA). Of these, two patients (1 Mason type III and 1 Mason type IV) were excluded from the analysis because severe cognitive impairment. Moreover, we decided to exclude the subjects with a Mason type IV fracture to obtain a more homogeneous sample. Therefore, 31 patients with a Mason type III fracture were included in this study. Based on the Mayo Elbow Performance Score, excellent results were obtained in 24 (77%) patients, good in 3 (10%) and fair in 4 (13%) patients. Heterotopic ossification was reported in 8 patients (26% of cases). The final elbow flexion-extension range of motion was of 112°, with a mean flexion of 125°. The final forearm rotational range of motion was 134° with a mean pronation of 68° and a mean supination of 66°.

DISCUSSION

Anatomic radial head replacement leads to a good functional recovery, even in the presence of severe instability, such as coronoid fractures and LUCL injury. However, patients should be informed of the high number of adverse events (mainly heterotopic ossification) following this treatment.

LEVEL OF EVIDENCE

Therapeutic IV.

Outcomes of Concomitant Fractures of the Radial Head and Capitellum: The "Kissing Lesion"

BACKGROUND

Radial head compression against the capitellum may cause concomitant fracture of the capitellum. The purpose of this study was to investigate if radial head fracture type is associated with a concomitant fracture of the capitellum.

PATIENTS AND METHODS

Data were identified from five area hospitals. We retrieved records of patients older than 18 years of age who underwent treatment for concomitant capitellum fracture and radial head fracture between January 2002 and January 2013. Patients with olecranon fractures or trochlea fractures were excluded.

RESULTS

A total of 10 patients with a radial head fracture and a concomitant capitellum fracture were included. Based on the operative reports, nine radial head fractures were classified as Hotchkiss modification of the Mason classification type II, and one was classified as type I. Based on the available radiographs and computed tomography, three capitellum fractures were type I, and seven were type II according to the Grantham classification.

CONCLUSION

Surgeons have to be alert to capitellar damage in case of a Hotchkiss type II radial head fracture.

LEVEL OF EVIDENCE

This is a level IV, therapeutic, retrospective study.

[Primary radial head arthroplasty in trauma : Complications]

Radial head fractures are common injuries in elbow trauma. Non-displaced fractures are best treated conservatively. Simple but displaced fractures require anatomic reduction and fixation, typically using screws. The treatment course for complex fractures with multiple fragments is still being debated, as results are less predictable. Radial head resection is not advised if concomitant injuries of the coronoid process or the collateral ligaments with instability are present. Favorable outcomes following open reduction and fixation using plates were reported recently. However, complication rates are very high. Radial head replacement is a valuable tool in treating complex fractures of the radial head with predominantly good and excellent results. Patients who suffer radial head fractures are typically of a younger age, resulting in high functional demands. Certainly, unspecific and specific complications related to radial head arthroplasty were reported in up to 40 % of cases in an acute fracture setting. This article highlights common complications in radial head arthroplasty and aims to present strategies to avoid them.

The clinical implications of heterotopic ossification in patients treated with radial head replacement for trauma: A case series and review of the literature

Radial head arthroplasty (RHA) is an acceptable treatment for comminuted radial head fractures (RHF). Fourteen patients with no postop HO prophylaxis were treated with RHA for comminuted RHF. A 50% incidence in HO was seen following RHA with a statistically increased risk (p ≤ 0.05) of reoperation compared to those without HO. Decreased ROM was seen on the affected side (p ≤ 0.05); patients without HO showed no statistical difference (p ≥ 0.05) in ROM or grip strength. HO following RHA increases patient risk for reoperation and decreases ROM. We recommend HO prophylaxis with NSAIDs and/or radiotherapy if no direct patient contraindications are found.

Factors associated with removal of a radial head prosthesis placed for acute trauma

PURPOSE

This study tests the hypothesis that there are no factors associated with removal or revision of a radial head prosthesis. A secondary analysis addressed the time to removal or revision.

METHODS

We reviewed the database of two large hospitals from 2000 to 2014 and identified 278 patients that had radial head replacement after an acute fracture or fracture dislocation of the elbow: 19 had removal and 3 had revision of the radial head implant within the study period. Explanatory variables including demographics, the type of injury, prosthesis type, surgeon, medical centre, and associated injuries were evaluated. Survival analysis using Kaplan-Meier curves evaluated time to removal/revision.

RESULTS

After adjustment for potential confounders using Cox regression multivariable analysis, hospital was the only factor independently associated with removal or revision (Hazard ratio=2.4, Confidence interval: 1.03-5.8, P value=0.043). The highest proportion of removal/revision was during the first year after implantation and decreased by half each year over the second to fourth years. The most common reason for removal of the prosthesis was to facilitate removal of heterotopic ossification (the majority with proximal radioulnar synostosis) rather than technical error or problems with the prostheses.

CONCLUSION

These findings suggest that the decision to remove a radial head prosthesis may depend more on surgeon or hospital preferences than on objective problems with the prosthesis. Until clarified by additional study, removal of a prosthesis should not be considered an objective outcome in research. In addition, patients offered removal of a radial head prosthesis, might get the opinion of more than one surgeon at more than one hospital before deciding whether or not to proceed.

LEVEL OF EVIDENCE

Level III Prognostic.

Outcomes and radiographic findings of anatomic press-fit radial head arthroplasty

BACKGROUND

Radial head arthroplasty (RHA) is a popular method of treatment for complex fractures of the radial head. The purpose of this study was to investigate patient outcomes and radiographic findings associated with a single anatomic monopolar press-fit radial head system commonly used for the treatment of radial head fractures.

METHODS

A retrospective review of prospectively collected data was performed for a consecutive series of patients treated with a press-fit anatomically designed RHA between November 2007 and April 2014. The most recent radiographs were evaluated for loosening, stress shielding, and instability. Postoperative motion and outcomes were reported at most recent follow-up.

RESULTS

At an average follow-up of 30 months, 6 of the 15 patients (40%) demonstrated radiographic loosening. Six of the 9 patients (67%) without loosening demonstrated stress shielding (average, 6 mm). Functional outcome scores included a mean American Shoulder and Elbow Surgeons score of 70, Mayo Elbow Performance Score of 85, visual analog scale score for pain of 2, visual analog scale score for function of 7, and Single Assessment Numeric Evaluation score of 75. Average flexion-extension arc was 14° to 138°, and average pronation-supination was 75° to 74°. All 6 of the patients with radiographic loosening had undergone RHA with an associated ligamentous injury repair. Satisfaction among patients was high as no patient reported an unsatisfactory outcome.

CONCLUSIONS

The use of an anatomic, press-fit monopolar RHA in the management of acute complex radial head fractures has yielded excellent clinical outcomes despite high rates of radiographic loosening and stress shielding. Press-fit RHA in the setting of ligamentous injury warrants further investigation because of a high rate of implant loosening observed.

Outcomes Following Radial Head Arthroplasty

Most current series of radial head arthroplasty include small numbers of patients with short- to medium-term follow-up and significant heterogeneity in patients, treatments, and outcome measures. The purpose of this systematic review was to review outcomes for radial head arthroplasty based on injury chronicity, injury pattern, and type of implant used. The authors systematically searched electronic databases for studies containing radial head arthroplasty or radial head replacement and identified 19 studies for inclusion in the analysis. For each included study, a composite mean was obtained for Mayo Elbow Performance Score (MEPS) and range of motion. Outcomes were said to differ significantly if their confidence intervals did not overlap. The MEPS for acute treatment (90) was higher than that for delayed treatment (81). There was no difference in the pooled MEPS between the isolated (89) and complex injury pattern (87) groups or implant material. There was no difference in range of motion between the acute and delayed or isolated and complex groups, but the average degree of pronation was higher in patients treated with titanium implants (76°) compared with cobalt chromium implants (66°). This systematic review suggests that outcomes are improved following acute arthroplasty for treatment of radial head fractures compared with delayed treatment, based on MEPS. The lack of other significant differences detected is likely due to the significant heterogeneity and inadequate power in current studies. Further prospective studies isolating the different variables will be needed to determine their true effect on outcomes. [Orthopedics. 2016; 39(3):153-160.].

Is the distal radioulnar variance useful for identification of radial head prosthesis overlengthening? A cadaver study

BACKGROUND

Overlengthening by radial head prosthetic replacement leads to insufficient functionality and increased capitellar wear. It has been shown that in monopolar prostheses, the radial overlengthening by an overstuffed prosthesis leads to significant differences in the distal radioulnar variance at the wrist. This study evaluated ipsilateral ulnar variance as a predictor for overlengthening after implantation of a multipolar prosthesis.

METHODS

The radial heads of seven fresh frozen upper extremities were resected and a multipolar radial head prosthesis was implanted. Thereafter, the native radioulnar variance at the wrist was documented via fluoroscopy. The alignment of the distal radioulnar joint in neutral, pronated and supinated rotational positions of the forearm was recorded fluoroscopically, and digital image analysis was performed regarding radioulnar shifting.

RESULTS

Statistical analysis of the difference between native height and the manipulated states did not show consistent significant differences with stepwise overlengthening of +1.5, +3, +4.5 and +6 mm and with respect to rotational position of the forearm (p > 0.05). Interclass correlation coefficients showed excellent interobserver reliability (ICC 96%), as did tests for intraobserver reliability (ICC 98-99%).

CONCLUSIONS

No consistent influence of overlengthening on the alignment of the radius and ulna at the distal radioulnar joint was found after sequential overlengthening with a multipolar prosthesis. Maybe the ligamentous structures of the forearm prevent significant longitudinal dislocation of the radius, as the multipolar prosthesis gives way by at the radiocapitellar joint. According to the data of the present study, the ipsilateral wrist is not useful in diagnosing overlengthening of the radial column in multipolar prosthetic replacement of the radial head-in contrast to the reported results with monopolar prostheses.

Outcome of Radial Head Arthroplasty in Comminuted Radial Head Fractures: Short and Midterm Results

Background:

Comminuted radial head fractures are often associated with secondary injuries and elbow instability.

Objectives:

The aim of this retrospective study was to evaluate how well the modular metallic radial head implant EVOLVE® prosthesis restores functional range of motion (ROM) and stability of the elbow in acute care.

Patients and Methods:

Eighty-five patients with comminuted radial head fractures and associated injuries received treatment with an EVOLVE® prosthesis between May 2001 and November 2009. Seventy-five patients were available for follow-up. On average, patients were followed for 41.5 months (33.0: 4.0 - 93.0). Outcome assessment was done on the basis of pain, ROM, strength, radiographic findings, and functional rating scores such as Broberg and Morrey, the Mayo elbow performance index (MEPI), and disabilities of the arm, shoulder and hand (DASH). Our study is currently the largest analysis of clinical outcome of a modular radial head replacement in the literature.

Results:

Overall, there were 2 (2.7%) Mason II fractures, 21 (28%) Mason III fractures, and 52 (69.3%) Mason IV fractures. Arbeitsgemeinschaft fur osteosynthesefragen (AO) classification was also determined. Of the 85 patients in our study, 75 were available for follow-up. Follow-up averaged 41.5 months (range, 4 - 93 months). Average scores for the cohort were as follows: Morrey, 85.7 (median 90.2; range 44.4 - 100); MEPI, 83.3 (85.0; 40.0 - 100); and DASH 26.1 points (22.5; 0.0 - 75.8). Mean flexion/extension in the affected joint was 125.7°/16.5°/0° in comparison to the noninjured side 138.5°/0°/1.2°. Mean pronation/supination was 70.5°/0°/67.1° in comparison to the noninjured side 83.6°/0°/84.3°. Handgrip strength of the injured compared to the non-injured arm was 78.8%. The following complications were also documented: 58 patients had periprosthetic radioluceny shown to be neither clinically significant nor relevant according to evaluated scores; 26 patients had moderate or severe periarticular ossification, and scored substantially worse according to MEPI and Morrey. Four patients required revisional surgery due to loosening of the prosthesis and chronic pain. In addition, one patient required a neurolysis of the ulnaris nerve, one developed a neobursa, and one had extensive swelling and blistering. The time interval between injury and treatment appeared to have an effect on results. Thirty-five patients were treated within the first 5 days after accident and showed better results than the 40 patients who were treated after 5 days.

Conclusions:

Comminuted radial head fractures with elbow instability can be treated well with a modular radial head prosthesis, which restores stability in acute treatment. The modular radial head arthroplasty used in this study showed promising findings in short to midterm results.

Radial head replacement in adults with recent fractures

Radial head fractures are fairly common (20% of all traumatic elbow injuries). Non-operative treatment is indicated in non-displaced fractures, and direct stable internal fixation allowing early elbow mobilisation in most other cases. For severely comminuted fractures precluding stable fixation, replacement of the radial head was introduced in the 1970s as a better alternative to simple radial head resection, which can induce instability of the elbow and/or forearm, most notably in patients who have complex fractures with concomitant lesions to other structures. With contemporary implants (modular or monoblock, with or without a mobile cup), mechanical stability is close to that provided by the native radial head, although appropriate treatment of concomitant lesions remains crucial (e.g., re-attachment of the radial collateral ligament, or distal radio-ulnar stabilisation in patients with Essex-Lopresti fracture). The key technical points are selection of implant size and determination of the optimal implantation height. The two most common complications are capitellar overloading due to excessively high implantation of the prosthetic head, which causes stiffness and pain, and loosening of the stem. These complications may require removal of the implant at a distance from the injury. Studies have demonstrated satisfactory clinical outcomes in 60% to 80% of cases.

Identification of overlengthening after replacement of the radial head with a bipolar prosthesis

INTRODUCTION

Overlengthening of the radial column leads to insufficient functionality and increased capitellar wear. Methods to detect or prevent overlengthening have been described for monopolar prostheses. The aim of this study was to evaluate whether one such method described by Athwal et al. is also applicable for a bipolar prosthesis.

MATERIALS AND METHODS

The radial heads of six fresh frozen upper extremities were resected. A bipolar radial head prosthesis was implanted in each, and the effects of sequential overlengthening on the alignment of the radiocapitellar and ulnohumeral joint line were recorded by fluoroscopic images. Digital image analysis and estimation of overlengthening followed according to the method described by Athwal et al.

RESULTS

Statistical analysis of the estimated and actual differences between the native state and bipolar replacement of the radial head with stepwise overlengthening of 1.5, 3, 4.5, and 6 mm showed a specificity of 86 % but consistently underestimated the amount of overlengthening with a sensitivity of only 61 %.

DISCUSSION

The method described by Athwal et al. for the identification of overlengthening by a monopolar prosthesis was not found to be reliable for ruling out or quantifying overlengthening of the tested bipolar prosthesis. However, the use of the method to detect (rule in) overlengthening may be acceptable in certain circumstances. A reliable method for postoperative quantification of overlengthening by bipolar prostheses has still to be found.