Pyrocarbon radial head arthroplasty offers satisfactory clinical and radiological outcomes with low revision rate: A systematic review

INTRODUCTION

Pyrocarbon promises to be an optimal material choice for radial head arthroplasty (RHA) due to an elastic modulus comparable to the radial diaphysis and thus providing higher biocompatibility. Primary objective was to determine the complications and revision rates related to the usage of these prostheses. The secondary objective was to assess the clinical and radiological outcomes of Pyrocarbon RHAs.

HYPOTHESIS

Pyrocarbon RHAs have good clinical and radiological outcomes with low complications and revisions.

METHODS

Ovid MEDLINE and Embase databases were used to search for studies on outcomes and complications of the RHAs using Pyrocarbon radial head prostheses. The systematic review was designed in accordance with the PRISMA guidelines and included studies were appraised using the MINORS tool. Complications and RHA revision rates were assessed. Functional outcomes were reviewed using PROMs (like MEPI, DASH and BMS), post-op range of motion (using goniometer) and grip strength (using the dynamometer). Postoperative radiological outcomes like peri-prosthetic lucency, radial neck osteolysis, radio-capitellar congruence, capitellar erosion, overstuffing/understuffing and osteoarthritis were reported using radiographs.

RESULTS

A total of 12 studies cumulatively reporting 353 patients who underwent Pyrocarbon RHAs were included in the review. The mean age of patients across the studies ranged from 47 to 54 years of which 50.5% were males. The majority of radial head replacements were done for acute trauma (87.5%) with the remainder done for arthritis (1.7%) and trauma sequelae (10.8%). Mean follow-up period in the selected studies ranged from 18 to 110 months with minimum follow-up across all studies being 12 months. Modular Pyrocarbon (MoPyC, Tornier™) was the implant of choice in ten studies while two studies used the Ascension Pyrocarbon radial head (Ascension Orthopaedics™). Ten studies demonstrated mean MEPI ranging from 75.5 to 96. Mean extension deficit ranged from 6 to 19 degrees, mean flexion from 120 to 140 degrees, mean pronation from 71 to 87 degrees and mean supination from 63 to 85 degrees. Relative grip strength ranged from 69 to 96% of the contralateral limb. Revisions due to implant-related reasons (intra-prosthetic dissociation, prosthetic fracture, peri-prosthetic loosening, radio-capitellar subluxation and understuffed/overstuffed elbow) was 6.8% (24/353). Radial stress shielding and peri-prosthetic lucency was reported in 10 to 100% of patients across different studies but symptomatic implant loosening leading to revision remained rare (2%, 7/353). Radio-capitellar congruence was reported in 81% to 100% cases while capitellar erosion ranged from 0% to 89%. Pyrocarbon implants specific complications included head-neck intra-prosthetic decoupling (1.1%) and pyrocarbon head fractures (0.9%). In total, 5.7% cases underwent re-surgery due to non-RHA related reasons.

DISCUSSION

The pyrocarbon RHA shows good functional outcome, range of motion and low revision rates. This aligns with the working hypothesis of this review. However, pyrocarbon radial head implants have implant-specific complications like pyrocarbon radial head fractures and intra-prosthetic decoupling between stem and head. Despite promising in vitro biomechanical properties, capitellar wear is still a common finding with pyrocarbon RHAs. Despite these factors, pyrocarbon radial head implants are a viable option for radial head arthroplasty.

LEVEL OF EVIDENCE

II; Systematic review.

Midterm outcomes of a short-cemented bipolar radial head arthroplasty, in a cohort of 56 cases with minimum 2-years follow-up

BACKGROUND

Radial head prostheses are used in comminuted radial head fractures for elbow stabilisation when reduction and internal fixation is not possible. Several implant designs exist, but no large series exist about a short-cemented and bipolar implant.

HYPOTHESIS

The hypothesis was that this prosthesis design shows good clinical, functional, and radiological results, with acceptable rate of complications.

STUDY DESIGN

This retrospective study included the prostheses with bipolar design and short-cemented stem (Evolutive™), with a minimum 2-years follow-up.

MATERIALS AND METHODS

All prosthesis implanted in our Traumatology Center were included, with minimum 2-years follow-up. The evaluation consisted of a clinical and functional evaluation, associated with an independent radiographic assessment. All complications were listed, as long as rate and reasons for implant removal.

RESULTS

Fifty-six implants were studied with a mean follow-up of 64.9months (24 to 119). Fifty-three cases were acute injuries with 16% isolated radial head fractures and 76% complex elbow injury such as ulno-humeral, radio-ulnar or longitudinal forearm instability. Fifty (89%) implants were still in place at last follow-up. The main reason for implant removal was during arthrolysis procedure. Ranges of motion were: 126° in flexion, 9° of extension loss, 76° of pronation and 79° of supination. Mean Mayo Elbow Performance Index was 84.1 with 72% of excellent or good results, and the median quick-DASH was rated 18.2. Radiographic evaluation found 12% significant ulno-humeral arthtitis, 64% capitellar osteopenia and 12% loosening. We recorded 5% of implant-related complications.

DISCUSSION

The short-cemented stem bipolar radial head prosthesis presents clinical and functional results similar to other radial head prosthesis with low incidence of elbow arthritis, when treating both isolated radial head fracture or complexes elbow injury. This implant should therefore be valid for treating comminuted radial head fractures in all types of traumatological injuries.

LEVEL OF EVIDENCE

IV; Retrospective cohort study.

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.

Intraoperative visualization of the posterolateral ulnohumeral joint space is reliable to indicate overlengthening in radial head arthroplasty

INTRODUCTION

Avoiding overlengthening in radial head arthroplasty (RHA) is essential for the prognosis of the elbow joint. An overlengthening from 2 mm is visible due to widening of the anterolateral ulnohumeral joint space but intraoperatively, this particular joint space is difficult to visualize. The commonly used Kocher approach allows visualization of the posterolateral joint space without additional instruments or further surgical release of the already unstable elbow. The aim of our study was to investigate whether the visualization of the posterolateral joint space is also a reliable method to indicate overlengthening in RHA.

MATERIAL AND METHODS

RHA was performed in five human cadaveric specimens with the forearm, wrist, and hand intact. The lateral ligament complex was detached and an anatomic transosseous refixation was performed. Six stages of implantation heights were documented: native joint (1), RHA at the anatomic height (2), + 2 mm (3), + 4 mm (4), + 6 mm (5) and - 2 mm (6). Macroscopic measurement and digital image analysis of the posterolateral and anterolateral ulnohumeral joint spaces were performed.

RESULTS

All stages of overlengthening showed a significant increase in posterolateral and anterolateral joint space widening (p < 0.05). The posterior and anterior joint space showed excellent intraclass correlation.

CONCLUSION

Visualization of the posterolateral aspect of the ulnohumeral joint space is a reliable indicator for overlengthening in RHA without further compromising an already unstable elbow. Correlation to the findings of the anterolateral ulnohumeral joint space in different implants leads to the assumption that visualization of either the anterior or posterior ulnohumeral joint space is universally applicable to determine overlengthening in RHA, regardless of the type of the radial head implant.

Radiographic and clinical comparisons between loose-fit and press-fit stems in monopolar radial head arthroplasty for comminuted radial head fractures

PURPOSE

Few clinical studies have compared the operative outcomes between loose- and press-fit stems in radial head arthroplasty (RHA). We aimed to evaluate the radiographic and clinical results of the two radial head implant concepts.

METHODS

In this retrospective multicenter study, 32 patients (24 women and 8 men) with a mean age of 63.1 years who underwent RHA for comminuted radial head fractures were reviewed between 2005 and 2021. Seventeen patients underwent RHA with a loose-fit stem (L-group), whereas the remaining fifteen patients underwent RHA with a press-fit stem (P-group). The mean follow-up period was 40.1 ± 9.9 months, with the minimum follow-up duration of 12 months. The radiographic findings were evaluated for periprosthetic osteolysis; furthermore, clinical outcomes were analyzed to measure the range of motion of the elbow. The rate of reoperations and prosthesis removal were also reviewed.

RESULTS

The general characteristics of the patients were similar in the two groups. The rate of periprosthetic osteolysis was 17.6% in the L-group, whereas it was 53.3% in the P-group. The mean elbow flexions were 128° and 133° in the L- and P-groups, respectively. The mean elbow extensions were -12° and -9° in the L- and P-groups, respectively. The rate of reoperation was 23.5% in the L-group and 15.2% in the P-group. One patient in the L-group had the prosthesis removed because of surgical site infection, whereas one patient in the P-group had the prosthesis removed owing to painful loosening.

CONCLUSIONS

No significant differences in the clinical outcomes and reoperation rate were observed between the two radial head implant concepts in this study. However, osteolysis occurred more frequently in the P-group. Although patients with periprosthetic osteolysis are currently asymptomatic, they should be carefully followed up for the symptoms in the long term.

90-day outcomes and factors for complications following radial head arthroplasty for Mason Type III and IV radial head fractures

PURPOSE

The aim of this study is to evaluate 90-day outcomes and complications following radial head arthroplasty (RHA) for Mason Type III and IV radial head fractures (RHFs) and determine factors predisposing patients to early complications and revision surgery.

METHODS

Patients undergoing RHA for Mason Type III and IV RHFs were identified retrospectively from an institutional database. Postoperative complications, reoperations, elbow range of motion, radiographs and concomitant injuries on the ipsilateral upper extremity were reviewed. Additionally, injuries were sub-classified as low-energy trauma (LET) or high-energy trauma (HET). Univariate logistic regression was performed to evaluate the risk for complications using patient factors not limited to the presence of concomitant ligamentous or bony injuries. P values < 0.05 were considered statistically significant.

RESULTS

Seventy four patients were included in our study with an average follow-up time of 12.7 months. Complications within 90-days of operation occurred in 8.1% of patients: heterotopic ossification (4.1%), superficial wound dehiscence (2.7%), and posterior interosseous nerve palsy (1.4%). No patients required readmission or revision surgery in the 90-day postoperative period. Univariate regression analysis did not demonstrate a significant association between diabetes, ASA status, HET versus LET, or the presence of concomitant injury. Concomitant injuries were found in 92% of patients.

CONCLUSION

Radial head arthroplasty for RHFs demonstrates a low complication rate in the short-term. Diabetes, ASA class, high versus low energy trauma, and presence of concomitant injury were not found to be associated with higher complication rates in the 90-day postoperative period.

LEVEL OF EVIDENCE

Level of evidence IV, retrospective case series.

Ulnohumeral joint static cartilage compression is affected by radial head implant size

INTRODUCTION

Radiocapitellar joint arthroplasty is a commonly performed procedure, which often leads to early failure or instability. Few studies assess the effect of radiocapitellar joint arthroplasty on the ulnohumeral joint. We hypothesized that static forces of contact (compressing cartilage, or cartilage relaxation contact force) would reveal the effect of varying radial head implant size and elbow position on the ulnohumeral joint.

METHODS

A minimally-invasive method of measuring cartilage relaxation contact force was utilized in 10 fresh-frozen human cadaveric specimens that did not require significant dissection or intraarticular sensor placement. Specimens were rigidly fixed in various positions of elbow flexion and forearm pronosupination with increasing radial head implant lengths. Uniaxial distracting forces were applied and displacement was repeatedly measured with resultant best-fit polynomial curves to determine inflections corresponding to the force required to overcome static cartilage relaxation as in previous work.

FINDINGS

Baseline mean (intra-cadaver) cartilage relaxation contact force was 11.8 N (standard error of the mean = 0.3) at 90° of elbow flexion and neutral rotation. There was little variation within specimens (Intraclass correlation coefficient > 0.94). Cartilage relaxation contact force increased at the ulnohumeral joint with radial head implant overstuffing (> 4 mm, P < 0.05) and elbow flexion (120°, P < 0.001). Pronosupination altered cartilage relaxation contact force in an implant-length independent manner (P < 0.05).

INTERPRETATION

Radiocapitellar joint arthroplasty implant length and elbow joint position independently contribute to increased cartilage relaxation contact force at the ulnohumeral joint. This further supports attempts at anatomic reconstruction of the radiocapitellar joint to prevent pathologic ulnohumeral joint loading.

Open Reduction Internal Fixation of Simple Versus Comminuted Radial Head Fractures: Comparison of Clinical Outcomes

PURPOSE

Current teaching suggests that modified Mason type III and IV fractures of the radial head involving more than 3 fragments should be treated with radial head arthroplasty. The purpose of this study was to compare the outcome of simple (2 or fewer intra-articular pieces) versus comminuted (3 or more intra-articular pieces) radial head fractures treated with open reduction internal fixation (ORIF).

METHODS

This was a retrospective review of 35 patients with modified Mason type III and IV fractures treated with ORIF. For the purpose of our study, simple fractures were defined as having 2 or fewer intra-articular fragments. Comminuted fractures were defined as having 3 or more intra-articular fragments. The primary outcomes were Broberg and Morrey rating system and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores. Reoperation rates and complications were also noted.

RESULTS

Thirty-five patients were evaluated, with a mean follow-up of 39.3 months. Thirteen patients had radial head fractures consisting of 2 or fewer intra-articular fragments. Twenty-two patients had radial head fractures consisting of 3 or more intra-articular fragments. Ages and follow-up times were similar in the 2 groups. Similar QuickDASH and Broberg and Morrey scores were seen when evaluating subgroups of 2, 3, and 4 fragment fractures. One patient from each group underwent revision surgery for symptomatic hardware.

CONCLUSIONS

In our series, we found similar clinical outcome scores and reoperation rates between simple and comminuted radial head fractures treated with ORIF. Fractures with more than 3 intra-articular fragments can be considered for ORIF.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Mid-term outcome following radial head arthroplasty in acute trauma: risk factors for poor outcome

BACKGROUND

The aims of this study were to evaluate the outcomes of a single type of radial head implant in a large cohort of patients at mid-term follow-up and to determine the associated risk factors for inferior functional outcomes.

METHODS

We performed a retrospective follow-up assessment of 65 patients (33 women and 32 men; mean age, 53.3 years [range, 22-81 years]) who underwent radial head arthroplasty (RHA) for acute trauma between 2012 and 2018, after a minimum follow-up period of 3 years. The Mayo Elbow Performance Score, Oxford Elbow Score, Disabilities of the Arm, Shoulder and Hand score, and Mayo Modified Wrist Score were evaluated, and all available radiographs were analyzed. All complications and revision procedures were assessed. Bivariate and multivariate regression analyses were performed to identify potential risk factors for a poor outcome following RHA.

RESULTS

After an average follow-up period of 4.1 years (range, 3-9.4 years), the mean Mayo Elbow Performance Score was 77.2 (standard deviation [SD], 18.9); mean Oxford Elbow Score, 32.0 (SD, 10.6); mean Mayo Modified Wrist Score, 74.6 (SD, 13.7); and mean Disabilities of the Arm, Shoulder and Hand score, 29.0 (SD, 21.2). Average range of motion measured 10° (SD, 15°) in extension, 125° (SD, 14°) in flexion, 81° (SD, 14°) in pronation, and 63° (SD, 24°) in supination. The overall complication and reoperation rates were 38.5% and 30.8%, respectively, with severe elbow stiffness being the most common reason for revision. Patient age >50 years, the use of an external fixator, the presence of accompanying medial collateral ligament injuries, and the development of higher-grade osteoarthritis were associated with a poor outcome.

CONCLUSION

Satisfactory medium-term outcomes can be achieved using a monopolar, long-stemmed RHA in patients with acute trauma. However, complication and revision rates are high, frequently leading to inferior outcome scores. Additionally, a higher patient age, the use of an external fixator, the presence of accompanying medial collateral ligament injuries, and the occurrence of higher-grade osteoarthritis were associated with a poor outcome; these factors should raise awareness by the treating trauma surgeon.

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.

Mason type III fractures of the radial head: ORIF, resection or prosthetic replacement?

PURPOSE

This study focused on a comparison of mid-term clinical, functional and radiographic outcomes of adults treated by open reduction and internal fixation (ORIF), radial head prosthesis (RHP) and resection (RHR).

METHODS

The retrospective evaluation concerned 47 surgically treated patients after a mean follow-up of 53 months. All patients were grouped according to the surgical procedure performed: 15 in the RHP group, 16 in the ORIF group and 16 in the RHR group. At the follow-up, outcome assessment was based on radiographs, range of motion (ROM) and functional rating scores.

RESULTS

Patients treated by RHR had significantly higher mean age and shorter operation time than other two groups. Compared to ROM, flexion, extension and pronation were significantly worse in patients treated by ORIF than those in the RHP group and the RHR group. Supination was significantly better in the RHP group. However, no statistical differences were observed in functional rating scores among the three groups. Regarding complications, instability was the only cause of revision surgery in the RHP group and the RHR group. On the other hand, the ORIF group revision rate was 50% and secondary displacement was the most frequent cause of failure.

CONCLUSION

The ORIF group did not show good results with greater elbow stiffness and higher revision rate than the other two techniques. RHR may be suitable for elderly patients with lower functional demands as it reported good clinical results and reduced operation time.

Current concepts in the management of radial head fractures: a national survey and review of the literature

INTRODUCTION

This study aims to report on current practice in the management of radial head fractures (RHFs) in the United Kingdom and to review the literature to identify areas for future investigation.

METHODS

A 12-question online survey was sent to 500 surgeon members of the British Elbow and Shoulder Society in 2021. Questions focused on clinical assessment, indications for surgical treatment and willingness to participate in future studies. Descriptive statistical analysis summarised the responses.

RESULTS

The response rate was 20.4% (n = 102). For minimally displaced RHFs, non-operative management with immediate mobilisation was reported by 90.2% (n = 92) as opposed to 9.8% (n = 10) for initial immobilisation in plaster or brace. The most cited indication for radial head arthroplasty as opposed to fixation was increased patient age or low functional demand in 69.9% of responses (n = 71). In total, 41.2% (n = 42) indicated the need for a future randomised controlled trial (RCT) concerning the management of RHF. Only five RCTs were returned by the literature review.

DISCUSSION

There is considerable variability in the management of RHF among an experienced cohort of surgeons. With the interest declared by the participating surgeons, there is a call for a well-designed sufficiently powered RCT.

[Radial head arthropolasty in unreconstructable comminuted fractures of the radial head: Long-term results and factors influencing the outcome]

BACKGROUND

Radial head arthroplasty is recognized as the gold standard in the treatment of patients with unreconstructable radial head fractures.

OBJECTIVE

The aim of this retrospective study was to investigate the long-term results after prosthetic replacement of the radial head and in a subgroup analysis to identify factors which influence the outcome.

MATERIAL AND METHODS

A total of 48 patients with unreconstructable fractures of the radial head and neck were treated by cementless radial head arthroplasty between 05/2008 and 10/2018 (30 bipolar prosthesis type rHead Recon, 18 monopolar prosthesis type MoPyc). After a mean follow-up of 4.6 years 39 patients were assessed clinically and radiologically.

RESULTS

The median MEP score was 95 points. Compared to the uninjured side the median range of motion was reduced by 10° for extension/flexion as well as for pronation/supination. In 36 of 39 cases an osseous integration of the prosthesis could be documented. One prosthesis had to be removed after 23 months because of painful loosening. Overlengthening was present in 11 cases (28%), 25 patients (64%) had subcollar bone resorption with a stable osteointegrated stem. Nonbridging heterotopic ossification was observed in 15 patients (38%), 16 patients (41%) showed posttraumatic arthrosis. Patients with sustained elbow dislocation had a significantly worse function in the MEP score and tended to develop an arthrosis more frequently. Ulnohumeral joint degeneration was significantly increased when overlengthening was present.

CONCLUSION

Radial head arthroplasty is an effective treatment option for unreconstructable fractures of the radial head and can provide good to excellent mid-term to long-term results. Sustained elbow dislocation as well as overlengthening of the prosthesis had a negative impact on the clinical outcome.

After failed radial head arthroplasty, what are the options? Risk factors and results of revisions in a multicenter study

Introduction

Few multicenter studies have analyzed the outcome of revision surgery of radial head arthroplasties (RHA) in the medium term follow up. The objective is twofold: to determine the factors associated with revision of RHAs and to analyze the results of revision with 2 surgical techniques: isolated removal of the RHA or revision with a new RHA (R-RHA).

Hypothesis

There are associated factors of RHA revision and RHA revision results in satisfactory clinical and functional outcomes.

Methods

Twenty-eight patients were included in this multicenter retrospective study, with all surgical indications for initial RHA being traumatic/post-traumatic. The mean age was 47 ± 13 years with a mean follow-up of 70 ± 48 months. This series included two groups: the isolated RHA removal group (n = 17) and the revision RHA with new radial head prosthesis (R-RHA) group (n = 11). Evaluation was clinical and radiological with univariate and multivariate analysis.

Results

Two factors associated with RHA revision were identified: a pre-existing capitellar lesion (p = 0.047) and a RHA placed for a secondary indication (<0.001). Revision for all 28 patients resulted in improved pain (pre-op Visual Analog Scale 4.7 ± 3 vs. post-op 1.57 ± 2.2, p < 0.001), mobilities (pre-op flexion 118 ± 20 vs. post-op 130 ± 13, p = 0.03; pre-op extension -30 ± 21 vs post-op -20 ± 15, p = 0.025; pre-op pronation 59 ± 12 vs post-op 72 ± 17, p = 0.04; pre-op supination 48 ± 2 vs post-op 65 ± 22, p = 0.027) and functional scores. Mobility and pain control were, for stable elbows, satisfactory in the isolated removal group. When the initial or revision indication was instability, the DASH (Disabilities of the Arm, Shoulder and Hand = 10 ± 5) and MEPS (Mayo Elbow Performance score = 85 ± 16) scores were satisfactory in the R-RHA group.

Discussion

In the case of a radial head fracture, RHA is a satisfactory first-line solution without pre-existing capitellar injury, its results being much weaker in the case of ORIF failure and fracture sequelae. In case of RHA revision, isolated removal or R-RHA adapted according to the pre-operative radio-clinical exam.

Level of evidence

IV.

Radial head replacement - A comprehensive review

Background

Radial head fractures represent 1-4% of all adult fractures and 1/3rd of elbow fractures (Kaas et al., 2010). Radial head is an important secondary stabilier of the elbow. The aim of the treatment of radial head fractures is to achieve stability and good functional outcome. Radial head replacement (RHR) is indicated when robust reconstruction and fixation of the fracture fragments is not possible.

Methods

This article explores history and evolution, anatomical considerations, biomechanics, implant designs, indications, surgical outcomes and controversies in radial head replacement based on current evidence.

Results

There is a wide range of RHR designs available without conclusive evidence to support the superiority of one design over the other. Ranges of motion, functional outcomes and complication were comparable among different designs with a high incidence of complications reported in many studies.

Conclusion

RHR remains a good option in unreconstructible radial head fractures, with potential to regain excellent function. It is imperative to continue with the quest to innovate and improve on current designs, to reduce complications in the long term.

The comparative performance of radial head prostheses in patients younger than and older than 50 years: a systematic review

Background

Patient age may play a role in the surgeon's decision between radial head arthroplasty (RHA) and open reduction internal fixation in radial head fracture treatment. Though large sample reports have detailed outcomes of radial head replacement for a mean age younger than 50 years, the age ranges are widely distributed. Patient outcomes are not uniform across a broad age distribution. Therefore, treatment decisions should be evaluated within the confines of a narrower age bracket. An understanding of clinical outcomes for radial head replacement in younger adults will provide value for guiding treatment decisions. We performed a systematic review comparing the clinical outcomes for radial head replacement in patients younger and older than 50 years of age. Further analysis compared outcomes between RHA performed as a primary procedure and as a secondary procedure in patients younger and older than 50 years of age.

Methods

PubMed was queried for articles which delineated individual patient data for age, surgical treatment, and appropriate outcome metrics. Articles were grouped based on patient age of under 50 and over 50 years and within those age groups, based on the arthroplasty being performed as a primary or as a secondary procedure.

Results

There were no significant differences between the under 50 and the over 50 groups for Mayo Elbow Performance Score (P = .79) and for implant revision/removal (P = .32). In the under 50 group, RHA done as a primary procedure had significantly higher (P = .001) mean Mayo Elbow Performance Score than RHA done as a secondary procedure. In the over 50 group, relative risk was 2.39 (95% confidence interval, 2.12-2.69) for implant revision/removal (P = .11) when comparing primary and secondary procedures.

Discussion

At a mean follow-up of 48 months, RHA in patients under the age of 50 years had satisfactory outcomes which were comparable to outcomes in patients over the age of 50 years. Across both age groups, arthroplasty performed as a primary procedure demonstrated superior outcomes compared to arthroplasty performed as a secondary procedure. Our findings provide guidance to surgeons who face a multifaceted decision when encountering younger adult patients with radial head fracture patterns that may not be amenable to fixation. Awareness of the age-specific performance of radial head implants is an important component of the decision for surgical treatment.

Acute versus delayed radial head arthroplasty for the treatment of radial head fractures

BACKGROUND

Radial head arthroplasty (RHA) is an important tool in the acute treatment of comminuted radial head and neck fractures. RHA is also performed in a delayed manner after failed open reduction and internal fixation, for fracture malunion or nonunion, and other chronic post-traumatic elbow disorders where restoration of the lateral column of the elbow is considered necessary. The relative efficacy and longevity of acute vs. delayed RHA is unknown. We sought to compare clinical, radiographic, and patient-reported outcomes between these groups.

METHODS

We identified patients ≥18 years old who underwent an RHA between 2000 and 2018 and then extracted 135 total elbows with a mean follow-up of 2.3 years that sustained isolated radial head fractures (30%), terrible triad injuries (66%), or Essex-Lopresti injuries (4%). The acute cohort (RHA: <12 weeks) contained 101 elbows that underwent surgery at a mean of 0.6 weeks (range, 0 days to 7 weeks, 96% <2 weeks) from injury, whereas the delayed cohort (RHA: 12 weeks to 2 years) contained 34 elbows that underwent surgery at a mean of 36 weeks (range, 14-82 weeks) from injury. Patients in the acute group had a higher percentage of terrible triad injuries (75% vs. 40%, P < .001) and Mason 3 fractures (98% vs. 45%, P < .001).

RESULTS

At the final follow-up, 13 of 101 patients in the acute cohort (13%) and 7 of 34 patients in the delayed cohort (21%) required implant revision or resection. A total of 25 patients (25%) in the acute cohort and 12 patients (35%) in the delayed cohort required a reoperation. Kaplan-Meier 2-year survival estimates free of implant resection or revision (90% acute, 86% delayed) and reoperation (76% acute, 70% delayed) were similar between groups. In patients with 5-year follow-up, there was an increased rate of revision or resection in the delayed group (30% vs. 13%). Two-year survival estimates free of radiographic loosening were 80% in the acute cohort vs. 57% in the delayed cohort (P = .04). Mayo Elbow Performance Score at 2 years demonstrated mean scores of 83 and 79 in the acute and delayed groups, respectively, with 71% of the acute cohort and 64% of the delayed cohort achieving good or excellent scores.

CONCLUSIONS

Our results demonstrated that although 2-year Kaplan-Meier survival free of revision or resection estimates and reoperation rates was equivalent between the groups, the delayed group experienced worse Mayo Elbow Performance Score outcomes, a higher revision or resection rate at 5 years, and an increased rate of radiographic loosening.

Elbow arthroplasty research methods, outcome domains, and instruments used in clinical outcome studies : a scoping review

AIMS

Arthroplasties of the elbow, including total elbow arthroplasty, radial head arthroplasty, distal humeral hemiarthroplasty, and radiocapitellar arthroplasty, are rarely undertaken. This scoping review aims to outline the current research in this area to inform the development of future research.

METHODS

A scoping review was undertaken adhering to the Joanna Briggs Institute guidelines using Medline, Embase, CENTRAL, and trial registries, limited to studies published between 1 January 1990 and 7 February 2021. Endnote software was used for screening and selection, and included randomized trials, non-randomized controlled trials, prospective and retrospective cohort studies, case-control studies, analytical cross-sectional studies, and case series of ten or more patients reporting the clinical outcomes of elbow arthroplasty. The results are presented as the number of types of studies, sample size, length of follow-up, clinical outcome domains and instruments used, sources of funding, and a narrative review.

RESULTS

A total of 362 studies met the inclusion criteria. Most were of total elbow arthroplasty (246; 68%), followed by radial head arthroplasty (100; 28%), distal humeral hemiarthroplasty (11; 3%), and radiocapitellar arthroplasty (5; 1%). Most were retrospective (326; 90%) and observational (315; 87%). The median sample size for all types of implant across all studies was 36 (interquartile range (IQR) 21 to 75). The median length of follow-up for all studies was 56 months (IQR 36 to 81). A total of 583 unique outcome descriptors were used and were categorized into 18 domains. A total of 105 instruments were used to measure 39 outcomes.

CONCLUSION

We found that most of the literature dealing with elbow arthroplasty consists of retrospective observational studies with small sample sizes and short follow-up. Many outcomes have been used with many different instruments for their measurement, indicating a need to define a core set of outcomes and instruments for future research in this area.Cite this article: Bone Joint J 2022;104-B(10):1148-1155.

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.

Radial head arthroplasty: a descriptive study of 970 patients in an integrated health care system

BACKGROUND

Radial head arthroplasty (RHA) is commonly performed for isolated comminuted radial head fractures and in conjunction with traumatic elbow instability. However, there is a paucity of literature directly describing the characteristics and outcomes of patients who undergo RHA in a community-based setting. We describe a cohort of 970 RHA performed in the California regions of a US integrated health care system over a 9-year period. Patient demographics, implant selection, 90-day acute postoperative events, and cumulative reoperation/revision rates are included.

METHODS

Patients aged ≥18 years who underwent primary RHA were identified (2009-2017). Patient characteristics and demographics, including age, body mass index, gender, diabetes status, American Society of Anesthesiologists (ASA) classification, primary diagnosis, and concomitant procedures were described. Crude cumulative revision and reoperation probabilities were calculated as 1 minus the Kaplan-Meier estimator, with follow-up time calculated as the time from the index RHA to revision/reoperation date for those with the outcome of interest and time from index RHA to censoring date (eg, date of death, health care termination, study end date [March 31, 2018]) for those without the outcome. Ninety-day postoperative incidence of emergency department (ED) visit, readmission, and mortality was calculated as the number of patients with the event of interest over the number of patients at risk.

RESULTS

A total of 970 patients underwent primary unilateral RHA by 205 surgeons during the study period. Annual procedure volume increased from 53 procedures in 2009 to 157 procedures in 2017. More patients were female, without diabetes, and had an ASA classification of 1 or 2. Fracture was the predominant indication for RHA (98.4%) and more than half (54.3%) had concomitant procedures performed. Most implants were press fit (63.2%) over loose fit, and >90% were monopolar. Three-year cumulative revision and reoperation probabilities following RHA were 6.5% (95% confidence interval [CI] = 5.0%-8.5%) and 8.2% (95% CI = 6.5%-10.3%), respectively. Revisions and reoperations tended to occur within the first postoperative year. Of the 970 RHA patients, 83 (8.5%) had a 90-day ED visit, 58 (6.0%) had a 90-day readmission, and 1 (0.1%) died within a 90-day postoperative period.

CONCLUSION

This large cohort of RHA patients provides information about the practice of RHA at large and in the community. Surgeons are performing more RHA over time and choosing press fit stems more often. Revisions and reoperations tended to occur early. Readmission and ED visits were low but not negligible, with pain being the most common reason for ED visit.

30-Day outcomes analysis of surgical management of radial head fractures comparing radial head arthroplasty to open reduction internal fixation

INTRODUCTION

Radial head arthroplasty and open reduction internal fixation are two commonly utilized treatment options for radial head fractures. The purpose of this study is to assess the incidence of and risk factors for short-term complications following radial head arthroplasty and open reduction internal fixation of radial head fractures.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients that underwent radial head arthroplasty or open reduction internal fixation for radial head fractures between January 1st, 2015 and December 31st, 2017. The incidence of various 30-day complications, including unplanned readmission, reoperation, non-home discharge, mortality, surgical/medical complications, and extended length-of-stay were compared between the two propensity matched groups. Multivariate logistic regression was used to identify independent risk factors for various short-term complications.

RESULTS

After propensity matching, a total of 435 patients were included in our analysis. 250 patients underwent radial head arthroplasty, and 185 patients underwent open reduction internal fixation. Arthroplasty treated patients had a significantly longer mean total operative time (p = .031) and length-of-stay (p = .003). No significant 30-day complications differences were found for unplanned readmission, reoperation, non-home discharge, mortality, surgical complications or medical complications. Independent risk factors for any complications of both procedures included a history of chronic obstructive pulmonary disease and American Society of Anesthesiologists class III. Significant risk factors for length-of-stay greater than two days included a history of bleeding disorder and American Society of Anesthesiologists class III.

CONCLUSION

Our study revealed there were no significant differences in 30-day perioperative surgical or medical complications from either surgical treatment of radial head fractures; however, radial head arthroplasty treated patients were met with a significantly longer length-of-stay and longer duration of operating time. We also identified risk factors that were independently associated with higher rates of complications regardless of treatment type.

Long-term outcomes of radial head arthroplasty for radial head fractures-a systematic review at minimum 8-year follow-up

BACKGROUND

The purpose of this study was to systematically review the literature to evaluate the functional outcomes, radiologic outcomes, and revision rates following radial head arthroplasty (RHA) at a minimum of 8 years follow-up.

METHODS

Two independent reviewers performed a literature search using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using PubMed, Embase, and Web of Science databases. Only studies reporting on outcomes of RHA with a minimum of mean 8 years' follow-up were considered for inclusion.

RESULTS

Our search found 10 studies including 432 elbows (51% males), with average age of 50 years (15-93) and mean follow-up of 117 months (98-145) met our inclusion criteria. At final follow-up, the mean Mayo Elbow Performance Score and Quick Disabilities of the Arm, Shoulder, and Hand questionnaire score were 83 (45-100) and 17 (0-63) respectively, and 86% of patients reported having no or minimal pain. The overall dislocation, subluxation, ulnar neuritis, and infection rates were 2%, 4%, 3%, and 3%, respectively. The rates of radiologic loosening, radiolucency, degenerative change, and heterotopic ossification were 9%, 46%, 27%, and 38%, respectively. The overall surgical revision rates were 20%, with 3%, 15%, and 5% requiring RHA implant revision, removal of metal or implants, and arthrolysis, respectively.

CONCLUSION

Our systematic review established that RHA results in satisfactory clinical outcomes and modest complication and revision rates at long-term follow-up, despite high levels of radiologic degenerative changes over the same period.

Long-term outcome and survival rate of monopolar radial head replacement

BACKGROUND

The purposes of this study were (1) to report functional outcomes; (2) to assess complications, revisions, and survival rate; and (3) to assess differences in functional outcomes between removed and retained radial head arthroplasties (RHAs), early and delayed treatment, and type of RHA used at long-term follow-up after monopolar RHA for unreconstructible radial head fractures or their sequelae.

METHODS

Seventy-eight patients (mean age, 59.2 years) who were at least 6 years postoperatively after monopolar RHA for unreconstructible RHFs or their sequelae were included. The Mayo Elbow Performance Score (MEPS); Quick Disability of the Arm, Shoulder, and Hand (QuickDASH) score; visual analog scale; postoperative satisfaction (1-6, 6 = highly unsatisfied); range of motion; complications; and revisions were assessed. Radiographic findings were reported. Kaplan-Meier survival analysis was performed. Subgroups (RHA type, early vs. delayed surgery, RHA removed vs. retained) were compared.

RESULTS

At a median clinical follow-up of 9.5 years (range: 6.0-28.4 years), median MEPS was 80.0 (interquartile range [IQR]: 60.0-97.5), median QuickDASH was 22.0 (IQR: 4.6-42.6), median visual analog scale was 1 (IQR: 0-4), median postoperative satisfaction was 2 (IQR: 1-3), and median arc of extension/flexion was 110° (IQR: 80°-130°). Radiographic follow-up was available for 48 patients at a median of 7.0 years (range: 2.0-15.0 years). Heterotopic ossifications were seen in 14 (29.2%), moderate-to-severe capitellar osteopenia/abrasion in 3 (6.1%), moderate-to-severe ulnohumeral degeneration in 3 (6.1%), and periprosthetic radiolucencies in 17 (35.4%) patients. Twenty-nine patients (37.2%) had complications and 20 patients (25.6%) underwent RHA exchange or removal. Kaplan-Meier analysis with failure defined as RHA exchange or removal demonstrated survival of 75.1% (95% confidence interval: 63.7-83.3) at 18 years. The highest annual failure rate was observed in the first year in which the RHAs of 7 patients (9%) were exchanged or removed. No significant differences were detected between type of RHA in MEPS (Mathys: 82.5 [75.0-100] vs. Evolve: 80.0 [60.0-95.0]; P = .341) and QuickDASH (Mathys: 12.5 [0-34.4] vs. Evolve: 26.7 [6.9-46.2]; P = .112). Early surgery (≤3 weeks) yielded significantly superior MEPS (80.0 [70.0-100.0] vs. 52.5 [30.0-83.8]; P = .014) and QuickDASH (18.6 [1.5-32.6] vs. 46.2 [31.5-75.6]; P = .002) compared with delayed surgery (>3 weeks). Patients with retained RHAs had significantly better MEPS (80.0 [67.5-100] vs. 70.0 [32.5-82.5]; P = .016) and QuickDASH (18.1 [1.7-31.9] vs. 49.1 [22.1-73.8]; P = .007) compared with patients with removed RHAs.

CONCLUSIONS

Long-term outcomes for RHA are satisfactory; however, there is a high complication and revision rate, resulting in implant survival of 75.1% at 18 years with the highest annual failure rate observed in the first postoperative year.

Mid-term clinical outcome comparison of long-stemmed monopolar osseointegrated and short-stemmed bipolar radial head prostheses

INTRODUCTION

Comparative data to guide implant choice for radial head replacements are lacking. Here, we compared the clinical results achieved using two different types of radial head prostheses.

METHODS

Data from patients with comminuted radial head fractures (n = 66), who underwent radial head arthroplasty with either short-stemmed bipolar (n = 31, Group 1: rHead Small Bone Innovations/USA) or monopolar long-stemmed osseointegrated rigidly fixed (n = 35, Group 2: MoPyC Tornier/France) prostheses, were retrospectively reviewed. Patients were followed-up for an average of 42 months (16-64 months). Range of elbow motion, elbow stability, grip strength, and visual analog scale (VAS) pain were measured, and functional outcome assessed using the Mayo Elbow Performance Score, the Disability of Arm, Shoulder and Hand questionnaire, and the Broberg-Morrey Score. Complications were analyzed and revision surgeries recorded.

RESULTS

Most patients achieved good/excellent results for all assessed outcome variables, with no significant differences between the two implant groups; however, regardless of the prosthesis type, a mean extension deficit of 18.5° ± 1.7° remained at latest follow-up. Although complication and surgical revision rates were comparable (bipolar, 23%; monopolar, 18%), significantly more bipolar prostheses were explanted because of painful loosening (16% vs. 3%; p = 0.029).

CONCLUSION

Good to excellent mid-term results for radial head arthroplasty of comminuted radial head fractures can be achieved using both a bipolar and a monopolar radial head implant; however, the monopolar implant may be preferable, as it had a lower rate of painful loosening. Extension deficit occurs regularly.

LEVEL OF EVIDENCE

Level III Retrospective comparative treatment study.

Post-traumatic elbow osteoarthritis after radial head arthroplasty: Prevalence and risk factors

BACKGROUND

One of the treatment options for comminuted radial head fractures is radial head arthroplasty (RHA), especially when the elbow is also dislocated. While the clinical outcomes of RHA have been well documented, the incidence of post-traumatic osteoarthritis after RHA and its risk factors are not well known.

OBJECTIVE

To determine the incidence of post-traumatic elbow osteoarthritis (humeroulnar and humeroradial joints) after RHA and identify its risk factors.

METHODS

All patients who underwent RHA at our hospital between 2008 and 2016 were included retrospectively. The inclusion criteria were primary RHA, recent radial head fracture (isolated or associated with elbow dislocation), minimum 1 year of follow-up, clinical and radiographic examination at final assessment. The exclusion criteria were pre-existing elbow osteoarthritis, RHA revision, multiple fractures of the ipsilateral upper limb or polytrauma. The final assessment consisted of a clinical examination [joint range of motion (ROM) and Mayo Elbow Performance Score (MEPS)] and standard radiographs. The correlation between the incidence and severity of osteoarthritis and various risk factors was determined.

RESULTS

Seventy-three patients were included in the analysis with a mean age of 56 years (21-85). The injuries consisted of 41 terrible triad, 15 isolated radial head fractures, 11 Monteggia fractures and 6 transolecranon fracture-dislocations. The mean follow-up was 3.4 years (1-10.9). At the final assessment, osteoarthritis was visible in the humeroulnar compartment in 56% of cases and in the humeroradial compartment in 72% of cases. There was a statistical correlation between the presence of humeroulnar osteoarthritis at the final assessment and ROM in flexion-extension (p=0.003), MEPS (p<0.001), duration of immobilization (p=0.03) and presence of posterior subluxation on immediate postoperative radiographs (p=0.012). The correlation between humeroradial osteoarthritis at the final assessment and ROM in flexion-extension (p=0.0054), RHA implant position (p<0.01), and unipolar configuration (p=0.027) was statistically significant.

CONCLUSION

In our study, elbow osteoarthritis incidence after RHA was 56% in the humeroulnar joint and 72% in the humeroradial joint. RHA implant placement, posterior subluxation immediately postoperative and the duration of immobilization were significantly corelated with osteoarthritis.

LEVEL OF EVIDENCE

IV; case series without control group.

Does shape and size of the stems affect the stress-shielding around press-fit radial head arthroplasty?

AIMS

It has been hypothesized that proximal radial neck resorption (PRNR) following press-fit radial head arthroplasty (RHA) is due to stress-shielding. We compared two different press-fit stems by means of radiographs to investigate whether the shape and size of the stems are correlated with the degree of PRNR.

METHODS

The radiographs of 52 RHAs were analyzed both at 14 days postoperatively and after two years. A cylindrical stem and a conical stem were implanted in 22 patients (group 1) and 30 patients (group 2), respectively. The PRNR was measured in the four quadrants of the radial neck and the degree of stem filling was calculated by analyzing the ratio between the prosthetic stem diameter (PSD) and the medullary canal diameter (MCD) at the proximal portion of the stem (level A), halfway along the stem length (level B), and distally at the stem tip (level C).

RESULTS

Overall, 50 of the 52 patients displayed PRNR. The mean PRNR observed was 3.9 mm (0 to 7.4). The degree of endomedullary stem filling at levels A, B, and C was 96%, 90%, and 68% in group 1, and 96%, 72%, and 57%, in group 2, with differences being significant at levels B (p < 0.001) and C (p < 0.001). No significant correlations emerged between the severity of PRNR and the three stem/canal ratios either within each group or between the groups.

CONCLUSION

PRNR in press-fit RHA appears to be independent of the shape and size of the stems. Other causes besides stem design should be investigated to explain completely this phenomenon. Cite this article: Bone Joint J 2021;103-B(3):530-535.

Surgical treatment of the radial head is crucial for the outcome in terrible triad injuries of the elbow

AIMS

To evaluate the outcomes of terrible triad injuries (TTIs) in mid-term follow-up and determine whether surgical treatment of the radial head influences clinical and radiological outcomes.

METHODS

Follow-up assessment of 88 patients with TTI (48 women, 40 men; mean age 57 years (18 to 82)) was performed after a mean of 4.5 years (2.0 to 9.4). The Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), and Disabilities of the Arm, Shoulder and Hand (DASH) score were evaluated. Radiographs of all patients were analyzed. Fracture types included 13 Mason type I, 16 type II, and 59 type III. Surgical treatment consisted of open reduction and internal fixation (ORIF) in all type II and reconstructable type III fractures, while radial head arthroplasty (RHA) was performed if reconstruction was not possible.

RESULTS

At follow-up the mean MEPS was 87.1 (20 to 100); mean OES, 36.9 (6 to 48); and mean DASH score, 18.6 (0 to 90). Mean movement was 118° (30° to 150°) for extension to flexion and 162° (90° to 180°) for pronation to supination. The overall reoperation rate was 24%, with nine ORIF, ten RHA, and two patients without treatment to the radial head needing surgical revision. When treated with RHA, Mason type III fractures exhibited significantly inferior outcomes. Suboptimal results were also identified in patients with degenerative or heterotopic changes on their latest radiograph. In contrast, more favourable outcomes were detected in patients with successful radial head reconstruction after Mason type III fractures.

CONCLUSION

Using a standardized protocol, sufficient elbow stability and good outcomes can be achieved in most TTIs. Although some bias in treatment allocation, with more severe injuries assigned to RHA, cannot be completely omitted, treatment of radial head fractures may have an independent effect on outcome, as patients subjected to RHA showed significantly inferior results compared to those subjected to reconstruction, in terms of elbow function, incidence of arthrosis, and postoperative complications. As RHA showed no apparent advantage in Mason type III injuries between the two treatment groups, we recommend reconstruction, providing stable fixation can be achieved. Cite this article: Bone Joint J 2020;102-B(12):1620-1628.

Functional outcomes evaluation after radial head arthoplasty in DR. Syaiful Anwar General Hospital: Case series

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Three case of radial head fracture treated with radial head arthroplasty.

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Evaluation of the functional outcomes after operative treatment of radial head arthroplasty.

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Functional outcomes assessment with active and passive range of motion.

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Satisfying result on pain and a fair result on functional outcome on patient follow-up.

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Good follow up is important to minimize the complications of radial head arthroplasty.

Introduction

Radial head arthroplasty (RHA) has become one of the mainstay surgical treatment for radial head fracture in certain conditions. Many previous studies compared the superiority of either open reduction and internal fixation (ORIF) and RHA with inconclusive result. Our case series aim to evaluate the functional outcome of the patients treated with RHA in our institution.

Presentation of case

We evaluated three patients who had RHA in 2018 and 2019. The function of flexion, extension, supination and pronation of the elbow was evaluated. The range of motion (ROM) was assessed in both active and passive way.

Discussion

An abundant of literatures stated that RHA result is superior than radial head resection and ORIF. Our case series present a satisfying result on pain and a fair result on functional outcome from the range of motion (ROM) evaluation on patient follow-up.

Conclusion

A good follow up for post-operative care plays an important role in management of RHA to minimize the rate of complications. In this case series, the functional outcomes after RHA is good, but a larger number of patient and longer follow up duration is needed for a better analysis.

Neurologic complications after surgical management of complex elbow trauma requiring radial head replacement

BACKGROUND

Radial head arthroplasty (RHA) has become a successful procedure for addressing acute unreconstructible radial head fractures that compromise elbow stability in complex elbow trauma. The purpose of this study was to investigate the incidence of and risk factors for the development of neurologic complications after surgical treatment of complex elbow fractures that require an RHA.

METHODS

Sixty-two patients with an unreconstructible radial head fracture and complex elbow instability treated with RHA were included. There were 33 men and 29 women, with a mean age of 54 years (range, 22-87 years). The average follow-up period was 5.2 years (range, 3-16 years). All patients were neurologically intact before surgery. The arthroplasty was implanted through a Kocher approach in 55 cases, whereas a Kaplan approach was used in 7. An uncemented smooth stem arthroplasty (Evolve) was used in 27 patients, and an anatomic ingrowth system (Anatomic Radial Head), in 35. At the time of surgery, 23 patients underwent fixation of a coronoid fracture and 15 underwent plating of the proximal ulna. All patients were clinically examined immediately after surgery and during follow-up to detect any degree of neurologic deficit. Radial and ulnar nerve injuries were classified according to the Hirachi and McGowan classifications, respectively. Functional outcomes were evaluated with the Mayo Elbow Performance Score.

RESULTS

A complete posterior interosseous nerve palsy occurred postoperatively in 2 patients. Hand function had completely recovered in both at 2 months after surgery without sequelae. Nine patients complained of ulnar nerve symptoms (immediately after surgery in 6 and as delayed ulnar neuropathy in 3). Most patients with ulnar nerve deficits had undergone additional surgical procedures to address ulnar fractures. Among patients with ulnar neuropathies, only 3 complained of mild sensory symptoms at the latest follow-up. No significant differences in range of motion and Mayo Elbow Performance Score were found between patients with and without neurologic complications. Associated olecranon or coronoid fixation and a prolonged tourniquet time were identified as risk factors for neurologic complications.

CONCLUSION

This study shows that the incidence of neurologic complications associated with the surgical treatment of complex elbow fractures requiring implantation of a radial head prosthesis may be underestimated in the literature. Inappropriate retraction in the anterior aspect of the radial neck, a prolonged ischemia time, and concomitant coronoid or olecranon fracture fixation represent the main risk factors for the development of this complication. Although the great majority of patients have full recovery of their nerve function, they should be advised on the risk of this stressful complication.

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.

A retrospective comparative cohort study of radial head arthroplasty versus resection in complex elbow dislocations

INTRODUCTION

The management of radial head fractures for the treatment of complex elbow dislocations remains controversial. Until the publication of recent therapeutic algorithms, different actions have been carried out, including resection or arthroplasty of the radial head. This study aims to compare the clinical and radiological results of these two techniques.

MATERIALS AND METHODS

A retrospective study was conducted between the years 2001 and 2016 in complex elbow dislocations associating comminuted fractures of the radial head (Mason type IV) for two cohorts: 20 patients who received a radial head prosthesis against 12 patients treated with resection. At the end of the follow-up, two functional valuation scales were applied: Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand score (DASH). Radiological study included the presence of post-traumatic osteoarthritis and heterotopic ossifications in both groups; and specific complications in the group of patients treated with an arthroplasty.

RESULTS

The average age of the sample was 52.2 years in the prosthesis group, and 58.5 for the resection group, with a mean follow-up of 83.8 and 163 months respectively. No statistically significant differences were found in the mean values of the MEPS scale between the two groups (p = 0.5). The mean DASH score was significantly higher in the resection group (29.8 versus 10.3 with p = 0.006). A significantly higher rate of reinterventions and heterotopic ossifications was documented in the group of patients treated with radial head excision. The rate of specific radiological complications in the prosthesis group was 45%.

CONCLUSIONS

Although radial head resection could be a valid treatment in this group of patients, radial head arthroplasty would remain as the main option for the treatment of these lesions.

LEVEL OF EVIDENCE

Level IV; Case Series; Treatment Study.

Comparison of bipolar and monopolar radial head prostheses in elbow fracture-dislocation

INTRODUCTION

The role of bipolar radial head prostheses (RHP) in elbow fracture-dislocation is controversial, with some reports of poorer stabilization than with monopolar designs. The aim of the present study was to compare mono- versus bi-polar RHPs in elbow fracture-dislocation. The study hypothesis was that mono- and bi-polar RHPs do not differ in clinical and radiological results, complications or revision rates.

MATERIAL AND METHODS

A single-center retrospective study included 58 patients, with a mean age of 55 years (range, 21-84 years). All received RHP for elbow dislocation with association: terrible triad, Monteggia fracture-dislocation, transolecranal dislocation or divergent dislocation. Two groups were compared: Mono-RHP, with monopolar prosthesis (n=40), and Bi-RHP, with bipolar prosthesis (n=18). All patients underwent clinical and radiological examination at last follow-up.

RESULTS

Mean follow-up was 42.7 months (range, 12-131 months). There were no significant (p>0.05) inter-group differences in range of motion or Mayo Elbow Performance Score. Mono- versus bi-polar design did not correlate with onset of complications (p=0.89), surgical revision (p=0.71), persistent or recurrent instability (p=0.59), or ulnohumeral (p=0.62) or capitulum (p=0.159) osteoarthritis at last follow-up.

DISCUSSION AND CONCLUSION

No differences were found between mono- and bi-polar RHPs in the treatment of elbow fracture-dislocation. Clinical and radiographic results were similar, as were complications and revision rates. The literature is inconclusive, reporting contradictory conclusions. We see no contraindications to bipolar RHPs in elbow dislocation with association, notably terrible triad injury.

LEVEL OF EVIDENCE

III, Retrospective case-control study.

Ex situ reconstruction of comminuted radial head fractures: is it truly worth a try?

INTRODUCTION

Complex radial head fractures are difficult to treat. In cases where stable fixation cannot be achieved, radial head resection or primary arthroplasty are frequently performed. Ex situ reconstruction of comminuted fractures may also be an option. This technique has widely been neglected in the literature, and only two small case series report satisfactory results. The aim of the present case series was to determine the functional and radiological outcomes of ex situ reconstructed Mason III and Mason IV fractures. We expect that the on-table reconstruction of comminuted radial head fractures will lead to bony union with no avascular necrosis in the postoperative course, which will demonstrate that this operative procedure is a reasonable option.

PATIENTS AND METHODS

Two Mason type III and seven Mason type IV fractures (including four Monteggia-like lesions) were reconstructed ex situ. The mean age of the patients was 47 years (range 22-64). The clinical examination included RoM tests, elbow stability tests, and a neurological examination. The functional outcome was assessed with the MEPS and DASH score. The radiographic examination included a.p. and lateral views of the elbow to detect non-unions, inadequacy or loss of reduction, radial head necrosis, heterotopic ossifications and signs of posttraumatic arthritis.

RESULTS

The mean follow-up time was 39 months (range 11-64). The mean MEPS was 82 points (range 15-100), and the mean DASH score was 20 points (range 0-85). All ex situ-reconstructed radial heads survived, and no signs of avascular necrosis were observed. Bony union was achieved in all but one patient who presented with an asymptomatic non-union. Signs of posttraumatic arthritis were found in all patients. With regard to the radial head, neither secondary resection nor arthroplasty had to be performed. All patients returned to their pre-injury occupations.

CONCLUSION

Ex situ radial head reconstruction can be a reliable option in the surgical treatment of complex radial head fractures associated with severe elbow trauma. Even in the midterm follow-up, no signs of avascular necrosis were observed. Modern implants may even extend the indications for reconstruction in such cases.

LEVEL OF EVIDENCE

Level IV-retrospective cohort study.

Ipsilateral proximal and distal radius fractures with unstable elbow joint: Which should we address first?

Simultaneous ipsilateral fractures involving radial head and distal end of radius are uncommon. We present our thoughts on which fracture should be addressed first. A 68-year-old lady sustained an ipsilateral fracture of the right radial head and distal end of radius following a fall. Clinically her right elbow was posteriorly dislocated and right wrist was deformed. Plain radiographs showed an intraarticular fracture of the distal end of radius and a comminution radial head fracture with a proximally migrated radius. Magnetic resonance imaging (MRI) showed no significant ligament injuries. We addressed her distal radius first with an anatomical locking plate followed by her radial head with a radial head replacement. Our rationale to treat the distal end radius: first was to obtain a correct alignment of Lister's tubercle and correct the distal radius height. Lister's tubercle was used to guide for the correct rotation of the radial head prosthesis. Correcting the distal end fracture radial height helped us with length selection of the radial head prosthesis and address the proximally migrated radial shaft and neck. Postoperative radiographs showed an acceptable reduction. The Cooney score was 75 at 3 months postoperatively, which was equivalent to a fair functional outcome.

Radial head arthroplasty for radial head fractures: a clinical and radiological comparison of monopolar and bipolar radial head arthroplasty at a mean follow-up of 6 years

PURPOSE

The purpose of this study was to compare clinical and radiographic outcomes of bipolar and monopolar radial head arthroplasty in treatment of radial head fracture at a mean follow-up of 6 years.

METHODS

A retrospective multicentre cohort study of 30 patients treated for unreconstructable radial head fractures. Patients were treated either with a cemented bipolar or an uncemented monopolar radial head arthroplasty. All patients included were evaluated with patient-rated outcome questionnaire, physical examination, and radiographic evaluation at a mean of 6 years (range, 2-12 years) postoperatively.

RESULTS

There was no statistical difference in QuickDASH between the bipolar or monopolar groups. The majority of patients had no to little pain during rest. Neither flexion nor extension of the injured arm was significantly affected by the type of prosthesis. None of the patients in the bipolar group had any secondary surgery at the time of follow-up. In the monopolar group, four patients required removal of the arthroplasty. Signs of ulnohumeral degenerative changes were seen in the majority of patients in both groups (55% in the monopolar group, 92% in the bipolar group).

CONCLUSION

In this retrospective cohort study comparing a bipolar and a monopolar radial head arthroplasty for treatment of radial head fractures, we found comparable functional outcome but more revision procedures in the monopolar group at a mean follow-up of 6 years.

Capitellar erosion after radial head arthroplasty: A comparative biomechanical study of operated radial head fractures on cadaveric specimens

BACKGROUND

We asked whether open reduction and internal fixation (ORIF) or radial head arthroplasty (RHA), common techniques used for the confrontation of displaced or comminuted radial head fractures, are correlated with cartilage wear of the capitulum.

HYPOTHESIS

We hypothesized that neither ORIF nor RHA are correlated with capitellar cartilage wear.

MATERIAL AND METHODS

On 5 cadaveric elbow specimens, osteotomies were employed to simulate radial head comminuted fractures followed with ORIF by Herbert screws. Radial heads were also excised from other 5 cadaveric elbow specimens and were replaced by metallic monopolar implants. Finally, 2 elbows were not operated and used as a control group. Custom-made rotary machines, working unstoppably, generated 700,000 pronation and supination forearm movements at a 110° arc of motion. The elbow joints were examined with pre- and postoperative magnetic resonance imaging (MRI) scans and the articular surfaces of the capitula were resected and sent for histopathology study.

RESULTS

In the 2 cadaveric elbows of the control group and the 4 elbows treated with ORIF, no cartilage damage was found. The fifth one displayed cartilage fissures, which were, classified according to International Cartilage Repair Society (ICRS) grading system as grade I cartilage damage. On the contrary, all 5 elbows treated with RHA sustained complete cartilage loss, exposure of the subchondral bone and were classified as ICRS grade IV cartilage damage.

DISCUSSION

Our study suggests that metallic monopolar RHA after a displaced or comminuted radial head fracture carries a high risk of rapidly evolving cartilage loss of the capitulum.

Short to midterm outcomes of one hundred and seventy one MoPyC radial head prostheses: meta-analysis

BACKGROUND

The MoPyC implant is an uncemented long-stemmed radial head prosthesis that obtains primary press-fit fixation via controlled expansion of the stem. Current literature regarding MoPyC implants appears promising; however, sample sizes in these studies are small. Our primary objective was to evaluate the short- to midterm clinical outcomes of a large sample of the MoPyC prostheses. The secondary objective was to determine the reasons for failure of the MoPyC devices.

METHODS

Four electronic databases were queried for literature published between January 2000 and March 2017. Articles describing clinical and radiographic outcomes as well as reasons for reoperation were included. A meta-analysis was performed to obtain range of motion, mean Mayo Elbow Performance score (MEPS), radiographic outcome, and reason for failure.

RESULTS

A total of five articles describing 171 patients (82 males) with MoPyC implants were included. Mean patient age and follow-up were 52 years (18-79) and 3.1 years (1-9), respectively. Midterm clinical results were good or excellent (MEPS > 74) in 157 patients. Overall complication rate was low (n = 22), while periprosthetic osteolysis was reported in 78 patients. Nineteen patients returned to the operating room, with implant revision being required in ten patients. The two primary reasons for failure were (intra-)prosthetic dislocation (n = 8) followed by stiffness (n = 7); no painful loosening was described.

CONCLUSION

Short- to midterm outcomes of MoPyC prostheses are satisfactory and complications associated are low. The use of stem auto-expansion as a mode of obtaining primary fixation in radial head arthroplasty appears to be an effective solution for reducing the risk of painful loosening.

Results after radial head arthroplasty in unstable fractures

BACKGROUND

Whereas most radial head fractures are stable injuries, they sometimes occur as part of complex injury patterns with associated elbow instability. Radial head arthroplasty has been favored in patients with unreconstructable radial head fractures and unstable elbow injuries. The purpose of this study was to review radiographic outcomes, functional outcomes, and complications after radial head arthroplasty for radial head fracture in unstable elbow injuries.

METHODS

This study was a retrospective review of radial head fractures treated with radial head arthroplasty by a single surgeon during a 15-year period. Demographics of the patients, injury details, operative reports, radiographic and clinical outcomes, and any complications were recorded. Patients were divided into stable and unstable elbow injury groups.

RESULTS

A total of 68 patients were included. There were 50 unstable fractures that were compared with 18 stable fractures. Patients with unstable radial head fractures with associated elbow dislocation achieved mean flexion and mean forearm rotational arc of motion similar to that of patients with stable radial head fractures. However, supination loss was greater in the unstable group than in the stable fracture group, with a mean difference of 10°. Radiographic outcomes and complication rates did not differ between injury groups. There was no observed decrease in implant longevity in patients with unstable elbow injuries.

CONCLUSIONS

Radial head arthroplasty is an effective option for treatment of unstable elbow injuries, with recovery of functional elbow range of motion and no difference in complication rate or implant survivorship compared with those patients with stable injuries.

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 prosthesis: surgical tips and tricks

Radial head prostheses (RHP) have been developed to decrease the complications rate following a radial head resection surgery. The aim of the RHP is to replicate the physiological radiocapitellar tracking, reproducing the mechanical function of the native radial head: to stabilize the elbow and to shear the forces passing through the elbow along with the other stabilizers. The currently used RHP models try to achieve this target with three different prosthesis' strategies: (a) loose fit stem, (b) bipolar radial head or (c) anatomical radial head. Even if the radial head fixation is the preferred technique in every possible case and the resection can be still considered a possible option, in the last years there has been a growing worldwide consensus in using the radial head replacement in patients with unfixable radial head fractures, especially if associated with complex elbow instability. However, complications after a RHP are not uncommon, and their rate is raising as long as the implants number are increasing. The main difficulties are due to the implantation technique that needs to be performed with the same attention and precision used for the replacement of all the other joints, and to the concurrent treatment of the associated lesions. A personalized postoperative rehabilitation program is essential for obtaining good results and decreasing the complications rate. Concern exists for the young age of the patients that often require a RHP: personal experience and literature analysis suggest that if the clinical and radiographic results are positive after a 6-12-month follow-up, good outcomes can be also expected at a medium- or long-term follow-up.

Trends in Management of Radial Head and Olecranon Fractures

Background:

Advancement in surgical techniques and implants has improved the ability to manage radial head and olecranon fractures. However, trends in management of these fractures are largely unstudied.

Objective:

This purpose of this study is to evaluate management trends for these common fractures.

Methods:

A retrospective review of a comprehensive Humana database was performed using Pearl Diver supercomputer (Warsaw, IN, USA) for radial head and neck (RHNF) and olecranon fractures (OF) between 2007 and 2014. Treatment methods including open reduction internal fixation (ORIF), radial head arthroplasty (RHA), and non-operative treatment were reviewed. Total reported incidence of office visits and utilization of each treatment modality were investigated. Sub-analysis with stratification by age 15-74 and greater than 75-years was performed for OF.

Results:

A total of 10,609 OF and 20,400 RHNF were identified between 2007 and 2014. A significant trend increase in the annual incidence of RHNF (266 cases/year, p<0.001) and OF (133.9 cases/year, p=0.001) was observed. A significant trend increase in annual percent utilization of RHA (0.22% per year, p=0.011) and a significant trend decrease in the annual percent utilization of ORIF (-1.0% per year, p=0.004) and non-operative management (-0.53% per year, p=0.046) was observed for RHNF. A significant trend increase was observed in percent utilization (0.40% per year, p=0.022) for OF non-operative management, especially in patients over 75 years (66% per year, p=0.034).

Conclusion:

The percentage of patients being treated with RHA is increasing. Non-operative management of OF has increased, specifically in the patients who are over 75 years.

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.

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.

Validation of the contralateral side as reference for selecting radial head implant sizes

Purpose

In arthroplasty of comminuted radial head fractures, the contralateral radial head diameter can be used as reference for implant selection. However, potential bilateral asymmetry may result in a mismatch of the implant with the native bone. Therefore, our purpose was to evaluate anatomical right-to-left differences of radial head diameters. We also compared conventional two-dimensional (2D) with three-dimensional (3D) measurements.

Methods

We used bilateral CT-scans from 25 intact proximal radius pairs of right-handed adult subjects to obtain 50 3D radial head models. After contralateral matching, diameters were calculated using a 3D-based method using an automated circle-fit in standardized cross-sections at the widest level midway through the radial head. The 3D-based diameters were compared to orthogonal line measurements in standard axial CT-slices.

Results

Three-dimensional analysis yielded a radial head diameter of 23.0 ± 1.7 mm. The dominant right side was significantly wider, with right-to-left differences of 0.2 ± 0.4 mm, with a maximum of 0.9 mm. The 2D-based diameter was 22.9 ± 1.7 mm, which was 0.1 ± 0.3 mm smaller compared to corresponding 3D-based diameter.

Conclusions

In healthy radial heads, the diameter was biased to the dominant right side, but individual differences were not larger than 1 mm. Compared to implant designs, in which diameter increments are usually 2 mm, this right-bias is not clinically relevant, as it would not affect implant selection. Therefore, the contralateral side can be considered a suitable reference. In clinical practice, the surgeon could estimate this diameter using standard axial CT slices, since its difference with the 3D-based evaluation was also relatively small compared to implant sizing increments.

Radial head implant diameter: A biomechanical assessment of the forgotten dimension

BACKGROUND

The effect of radial head implant length has been a subject of controversy, with the impact on clinical outcomes and forearm biomechanics being extensively studied. However, the impact of radial head diameter on forearm load transfer has not been examined. This study examined the influence of radial head implant diameter on forearm load transfer as measured by interosseous membrane tension and radiocapitellar joint contact characteristics.

METHODS

An upper extremity simulator was utilized to study five cadaveric specimens with three different radial head implant diameters (-2mm, anatomically sized, +2mm). A load sensing device was woven into the fibers of the central band of the interosseous membrane to quantify its tension. An inter-positional pressure measurement sensor was used to quantify radiocapitellar joint contact force and area. Axial loads of 160N were applied to the forearm during forearm rotation with the elbow at 90° of flexion.

FINDINGS

Changes to the radial head diameter did not change radiocapitellar contact force or area (P=0.4 and P=0.5 respectively). There was a linear relationship between radial head diameter and interosseous membrane tension; increasing radial head diameter increases the interosseous membrane tension (P=0.01).

INTERPRETATION

Although radial head diameter was not found to alter radiocapitellar contact area or force, the interosseous membrane tension was impacted. After radial head arthroplasty, an increase in radial head implant diameter increases the interosseous membrane tension, with a potential for increased pain and stiffness. There is also a potential for increased proximal radioulnar joint contact pressures; resulting in stem loosening or radio-ulnar pain.

Radial head, radiocapitellar and total elbow arthroplasties: a review of recent literature

The outcome of prosthetic elbow surgery is continually evolving. We thoroughly reviewed the literature on this issue to analyse the indications, outcomes and complications of the numerous types of implants currently in use. Radial head replacement is recommended in comminuted fractures of the radial head and in post-traumatic conditions. Medium- and long-term results prove to be satisfactory in the majority of cases, with no evidence to indicate that some prostheses (monopolar vs. bipolar; cemented vs. press-fit) are more effective than others; nonetheless, the bipolar-cemented implant was found to be associated with a lower revision rate than other prostheses. Unicompartmental arthroplasty has recently been used for the treatment of osteoarthritis and rheumatoid arthritis when the lateral compartment is prevalently involved; the results reported to date have been encouraging, although further studies are warranted to confirm the validity of these implants. Total elbow arthroplasty is performed in a range of conditions, including distal humerus fractures in the elderly and elbow arthritis. In the former condition, linked elbow replacement yields excellent results with few complications and a low revision rate. In elbow arthritis, total elbow arthroplasty is indicated when patients suffer from disabling pain, stiffness and/or instability that prevent them from performing daily activities. Unlinked elbow arthroplasty, which is used above all in rheumatoid arthritis, also yields satisfactory results, although the risk of instability persists. The use of linked elbow arthroplasty, which yields similar results but lower revision rates, has consequently increased. Lastly, the results yielded by linked elbow prosthesis in post-traumatic conditions are good, although not quite as good as those obtained in rheumatoid arthritis. Early mechanical failure may occur in younger and more active patients after elbow arthroplasty. However, the careful selection of patients who are prepared to accept functional limitations imposed by elbow implants will enable indications for elbow arthroplasty to be extended to young subjects, particularly when no other therapeutic options are available.

The bicipital tuberosity and distal radius are unreliable landmarks for radial head implant alignment

BACKGROUND

As more anatomic asymmetric radial head implants emerge, it is necessary to determine the optimal landmarks to ensure correct rotational orientation. The bicipital tuberosity and distal radius are possible bony landmarks that can be used for rotational alignment of asymmetric prostheses; however, they have not been validated. The purpose of this study was to evaluate the reliability of the bicipital tuberosity and distal radius as rotational landmarks for orientation of asymmetric radial head prostheses.

METHODS

Measurements were made from computer tomography scans of 50 elbows in order to determine the rotational relationships between the radial head, bicipital tuberosity, biceps tendon footprint, and distal radius.

RESULTS

The maximum radial head diameter was oriented 65° ± 28° from the bicipital tuberosity, 119° ± 38° from the biceps tendon footprint, 82° ± 29° from the radial styloid, and 76° ± 28° from the volar surface of the distal radius. All of these landmarks had a significantly greater variance than a proposed acceptable clinical tolerance of 10° (P < .001).

CONCLUSION

The results demonstrate that the measured landmarks show no consistent rotational relationship with the maximum diameter of the radial head. In order to maximize the utility of more anatomic asymmetric radial head implant systems, further studies are necessary to identify more reliable rotational landmarks to ensure optimal implant positioning.

Clinical and radiographic comparisons of two different radial head implant designs

BACKGROUND

There is little comparative data to guide implant choice for radial head replacements. The purpose of this study was to evaluate the clinical and radiographic results between patients who received a smooth-stemmed bipolar radial head implant and patients who received an in-growth monopolar prosthesis.

METHODS

Twenty-seven patients requiring a metallic radial head implant in the management of acute or chronic elbow trauma were evaluated. Fourteen patients received a smooth-stemmed bipolar prosthesis and 13 patients received a press-fit monopolar prosthesis. Patients returned for follow-up at an average of 33 months (range, 18-57). Outcome assessments included joint motion, elbow stability, grip strength, pain, the Mayo Elbow Performance Index, and the Disability of Arm, Shoulder and Hand questionnaire. Radiographs were reviewed for joint congruence, ectopic bone, periprosthetic osteolysis, degenerative arthritis, and capitellar wear, and selected patients were tested for inflammatory markers and metal ion levels.

RESULTS

The differences between patient groups for elbow flexion and forearm pronation averaged 10° or less. There were no other pertinent differences between groups for standardized patient and examiner-determined outcomes. There was a trend for ectopic bone to develop more commonly around the smooth-stemmed implants, while periprosthetic osteolysis was more pronounced in cases with the press-fit design. Inflammatory markers were normal, and metal ion levels did not exceed values reported for a well-functioning hip arthroplasty.

CONCLUSION

Outcomes at short- to mid-term follow-up were similar with either implant design. Loosening of a press-fit prosthesis may lead to extensive osteolysis, but of undetermined clinical consequence.