Outcomes of bipolar radial head prosthesis to treat complex radial head fractures in 22 patients with a mean follow-up of 50 months

Demographics, Indications, and Revision Rates for Radial Head Arthroplasty: Analysis of Data from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

Population-level data from national arthroplasty registries enable the use and outcomes of arthroplasty procedures to be monitored over time. This study aimed to describe the demographics, indications, and outcomes (up to 15 years) for radial head arthroplasty (RHA) procedures in Australia, as well as the factors associated with an increased likelihood of revision.

METHODS

Individual-level deidentified data on demographics and surgery characteristics, including revision surgery, were obtained from the Australian Orthopaedic Association National Joint Replacement Registry for all primary isolated RHA procedures that had been performed from 2007 to 2021. The probability of prosthesis survival was determined using Kaplan-Meier estimates. Cox proportional hazards models were used to calculate hazard ratios (HRs) for revision.

RESULTS

A total of 3,457 primary RHAs were performed during the study period (mean follow-up, 5.6 years; range, 0 to 15 years). The mean age at the time of RHA was 53 years, with female predominance (n = 2,009, 58%). The most common indication for RHA was fracture or dislocation (n = 3,166, 92%), followed by osteoarthritis (n = 232, 7%). The radial head prostheses that were most commonly used were monopolar (n = 3,378, 98%) with a modular design (n = 3,442, 99.6%) and cementless fixation (n = 3,387, 98%). Both metallic and nonmetallic prostheses were used (52% and 48%, respectively). Of the total cohort, 160 revisions (5%) were performed during the 15-year period; most revisions occurred in the first 5 years. The most common revision indication was prosthesis loosening (n = 62, 39%), and 54% of the revisions (n = 87) involved a change of the radial component. In multivariable analysis, primary procedures for osteoarthritis (HR, 1.65; 95% confidence interval [CI], 1.01 to 2.70) or "other" indications (e.g., inflammatory arthritis, osteonecrosis, or tumor) were revised more frequently (HR, 3.68; 95% CI, 1.14 to 11.91) than procedures for fracture or dislocation. Procedures with nonmetallic prostheses had higher rates of revision (HR, 1.61; 95% CI, 1.17 to 2.22) than those with metallic prostheses.

CONCLUSIONS

Trauma remained the most prevalent indication for RHA in Australia from 2007 to 2021. Encouragingly, revision rates were low, most notably for RHA that had been performed for fracture or dislocation. The likelihood of revision was highest for RHA procedures performed for osteoarthritis and for an indication other than osteoarthritis or trauma. Nonmetallic prostheses had a higher rate of revision than metallic prostheses.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

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.

[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.

Clinical and radiological outcome of Mason-Johnston types III and IV radial head fractures treated by an on-table reconstruction

Background

Only few methods treating comminuted radial head fractures have been established providing sufficient joint reconstruction, restoring radial length and enabling early joint mobilization. When an anatomical reconstruction using open reduction and internal fixation is not possible, radial head resection or primary arthroplasty is often conducted. An “Ex situ/on-table” reconstruction is widely disregarded but can be an option. The purpose of this study was to evaluate the functional and radiological outcome of comminuted radial head fractures treated with an “on-table” reconstruction and internal fixation using a low profile plate.

Methods

Fourteen patients who sustained a radial head fracture (9 Mason-Johnston type III and 5 Mason-Johnston type IV) and were treated with an “on-table” reconstruction between 2010 and 2020 were evaluated retrospectively. The patients mean age was 41.3 years (range 21–69). The clinical evaluation included active range of motion, grip strength, pain level and elbow stability. The functional outcome was assessed using the Disability of Arm, Shoulder and the Hand (DASH) score, Mayo Elbow Performance Index (MEPI), Broberg and Morrey score. The radiological examination included a.p. and lateral views of the injured elbow to evaluate nonunions, loss of reduction, joint alignment, avascular radial head necrosis, heterotopic ossifications and posttraumatic osteoarthritis.

Results

The inclusion rate was 74% with a mean follow-up of 50 months (range 16–128). The mean elbow flexion of the injured side was 126° (range110–145°) with an average extension loss of 8° (range 0–40°). Pronation was 65° (15–90°) and supination 66° (5–90°). The mean MEPI was 87 points (range 45–100). The mean DASH score was 13 points (range 1–88). According to the Broberg and Morrey functional scoring system, the average score was 92 points (range 88–100). Complete bone union was achieved in 9 cases, partial union in 4 cases and nonunion in one case. There were no signs of avascular necrosis of the radial head. Signs of post-traumatic osteoarthritis were seen in 11 cases. Five patients needed an implant removal due to a radio-ulnar impingement and one patient a revision surgery due to the nonunion and implant breakage.

Conclusions

An on-table (ex situ) reconstruction of the radial head is a reliable option with a good clinical outcome and low complication rate in the surgical treatment of comminuted radial head fractures. It can restore joint alignment and maintain radial length. The risk for avascular necrosis is neglectable, and the bone healing rate is high.

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.

A registry study on radial head arthroplasties in the Netherlands: Indications, types and short-term survival

BACKGROUND

This study aims to use the Dutch Arthroplasty Register data to report an overview of the contemporary indications and implant designs, and report the short-term survival of radial head arthroplasty.

METHODS

From the Dutch Arthroplasty Register, data on patient demographics, surgery and revision were extracted for radial head arthroplasties performed from January 2014 to December 2019. Implant survival was calculated using the Kaplan-Meier method.

RESULTS

Two hundred fifty-eight arthroplasties were included with a median follow-up of 2.2 years. The most common indication was a fracture of the radial head (178, 69%). One hundred thirty-nine (68%) of the prostheses were of bipolar design, and the most commonly used implant type was the Radial Head System (Tornier; 134, 51%). Of the 258 included radial head arthroplasties, 16 were revised at a median of six months after surgery. Reason for revision was predominantly aseptic loosening (9). The overall implant survival was 95.8% after one year, 90.5% after three years and 89.5% after five years.

DISCUSSION

For radial head arthroplasties, acute trauma is the most common indication and Radial Head System the most commonly used implant. The implant survival is 89.5% after five years.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Factors influencing the mid-term radiological and functional outcomes of 41 post-fracture bipolar radial head arthroplasty cases at a mean follow-up of 87 months

INTRODUCTION

When treating comminuted radial head fractures that cannot be adequately fixed, the next option is arthroplasty (radial head replacement). We hypothesized that the radiological and functional outcomes of bipolar mobile cup radial head arthroplasty is not influenced by the length of follow-up but instead by the correct positioning of the implant intraoperatively and by the presence of associated bone or ligament injuries.

PATIENTS AND METHODS

Between May 1998 and December 2016, 82 cases of radial head arthroplasty were performed at our hospital. The mean age of patients at the time of arthroplasty was 53 years (22-81). Ligament or bone injuries complicated the radial head fractures in 70% of patients.

RESULTS

For the final assessment, 41 patients were reviewed and included in the statistical analysis with a mean of 82 months (12-228). The mean MEPS at the final assessment was 88.7 (61-100). There were 23 excellent, 9 good, 9 average and 0 poor results. The average DASH score was 18.7 (0-55). The average VAS for pain was 1.0 (0-5). Five patients (12%) required surgical revision, including one implant change. Our statistical analysis found no relationship between follow-up time and functional outcomes. The appearance of periprosthetic radiolucent lines was not affected by the length of follow-up. Associated bone or ligament injuries significantly increased the probability of periprosthetic radiolucent lines, humeroulnar joint degeneration and decentering of the implanted cup. Radiological evidence of a suspended implant was associated with significantly worse functional outcomes.

CONCLUSION

This study confirms the long-term stability of the clinical outcomes of radial head arthroplasty. There was no relationship between worsening radiological appearance of the implant and the clinical outcomes. It is critical that this implant not be oversized or suspended, as this can trigger premature capitellar erosion and painful stiffness of the operated elbow.

LEVEL OF EVIDENCE

IV; systematic retrospective analysis.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Surgical treatment of terrible triad of the elbow

Terrible triad of the elbow associates posterior dislocation, radial head fracture and coronoid process fracture. It is a complex trauma, associating severe bone and ligament lesions, with high more-or-less long-term risk of residual instability, stiffness, pain and osteoarthritis. During the last 20 years, pathologic, biomechanical and clinical knowledge has greatly progressed. Prevention of these severe complications requires initial understanding of the lesion mechanism and precise analysis of all lesions. Surgery aims to restore perfect stability by sequential anatomic repair, enabling early mobilization to prevent onset of stiffness. The aims of the present paper were to summarize the anatomic and pathophysiological bases, highlight the crucial importance of the humeroradial column and lateral collateral ligament, and to determine the importance of the coronoid process. Some aspects of treatment are controversial: systematic medial collateral ligament repair, or use of an articulated external fixator. Finally, we propose a simple algorithm to guide repair.

Simultaneous ipsilateral distal radius and radial head fractures: Two case reports of radius bipolar fracture

RATIONALE

Distal radius fracture with simultaneous ipsilateral radial head fracture is a very rare pattern of injury. This type of injury is referred to as 'radius bipolar fracture'. Treatments for this injury pattern can be challenging because both the wrist and elbow need to be considered. There are currently no guidelines for the treatment of this specific type of injury. We report two cases of this unusual pattern of injury treated in our hospital.

PATIENT CONCERNS

Case 1 was a 78-year-old female patient and case 2 was a 19-year-old female patient who visited our emergency department with left elbow and wrist pain after slipping and falling.

DIAGNOSIS

Plain radiography and computed tomography revealed radius bipolar fracture. Case 1 had an AO type C3 distal radius fracture, a Mason type III radial head fracture. Case 2 had an AO type B2 undisplaced distal radius fracture and a Mason type III radial head fracture.

INTERVENTIONS

In case 1, open reduction and internal fixation (ORIF) was performed for the distal radius fracture and radial head replacement arthroplasty for the radial head fracture. In case 2, distal radius fracture was treated conservatively and ORIF was performed for the radial head fracture.

OUTCOMES

Bony union as achieved in both cases. At 1-year follow-up, case 1 showed slight limited range of motion of the wrist. Case 2 showed no radius shortening and full range of motion of the wrist and elbow. The Quick disabilities of the arm, shoulder and hand score was 18 and 16, respectively.

LESSONS

After this type of injury, the radius length can be changed, and as a result, ulnar variance can be affected. When radial head replaced is considered, it would be better to operate on the wrist first, and then perform radial head replacement. In this way, radiocapitellar overstuffing or instability can be prevented. However, if ORIF is planned for proximal radius fracture, either the proximal or distal radius can be fixed first. Surgeons should try to preserve radial length during treatment to optimize patient outcomes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Acute radial head replacement with bipolar prostheses: midterm results

In irreparable radial head fractures, especially if primary stabilizers of the elbow are damaged, the prosthetic replacement prevents instability and stiffness. Concerns have arisen over the use of bipolar press-fit prostheses due to the frequent finding of osteolysis and the risk of instability if compared to monopolar implants. Our aim was to assess midterm clinical and radiological outcomes of bipolar implants and the influence of osteolysis on proximal pain. Seventeen patients with irreparable fractures of the radial head, treated in acute with the same prosthetic model (rHEAD recon SBI/Stryker) between January 2015 and December 2018, were enrolled. Clinical assessment was performed using MEPS and DASH scores; a radiographic study was done to identify heterotopic ossifications and periprosthetic osteolysis. Outcomes at the last follow-up, according to MEPS, were excellent in 10 cases, good in 5 and fair in 2; none of the patients had severe pain or instability. In 3 cases, it was necessary to remove the implant, mainly because of early loosening. Radiological findings of osteolysis were detected in 9 cases, but no statistical correlation was found with MEPS and proximal pain. The use of bipolar implants is reliable if an accurate repair of ligament tears is performed and provides a good stability. Nevertheless, the risk of early aseptic loosening in uncemented implants is not negligible, and the follow-up of the patient must be strict. Late osteolysis does not seem to have clinical relevance, but further prospective studies are necessary to clarify this topic.

Management of the failed radial head arthroplasty

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

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

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

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

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

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

Relationship between the tilt angle of bipolar radial head prostheses and radiological radiocapitellar instability

OBJECTIVE

This study aimed to radiologically assess the relationship between the tilt angle of the bipolar radial head prostheses and radiocapitellar instability.

METHODS

In this radiological study, 28 consecutive patients (13 females and 15 males: mean age=47 years and age range=23-77 years) who underwent cemented bipolar radial head arthroplasty (Judet CRF II) because of comminuted radial head fracture with elbow instability were retrospectively reviewed.

RESULTS

There was excellent intra- and interobserver reliability for the measurements of the tilt angle and the radiocapitellar distance. ICC for interobserver reliability of the tilt angle was 0.93, and ICC for intraobserver reliability for the 2 observers was 0.96 and 0.97, respectively. ICC for interobserver reliability of the radiocapitellar distance was 0.87, and ICC for intraobserver reliability for the 2 observers was 0.91 and 0.93, respectively. The mean tilt angle was 17.6° (range=1°-35°), and the mean radiocapitellar distance was 8 mm (range=1-17 mm). Pearson's correlation revealed a strong significant positive correlation between the tilt angle and the radiocapitellar distance (r=0.77 and p<0.001).

CONCLUSION

Evidence from this study has demonstrated a strong positive correlation between the tilt angle of bipolar radial head prostheses and radiocapitellar instability. The tilt angle can be used as an indicator of radiocapitellar joint instability following bipolar radial head prostheses.

LEVEL OF EVIDENCE

Level IV, Diagnostic study.

Radial head fractures

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

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.

Radial head arthroplasty: fixed-stem implants are not all equal-a systematic review and meta-analysis

Background

Numerous fixed-stem implants exist for radial head arthroplasty; therefore, we conducted a systematic review to compare the safety and efficacy of different types of fixed-stem implants.

Methods

We conducted a literature search, updated from a previous systematic review, to identify studies evaluating a fixed-stem radial head arthroplasty implant for any indication. We extracted data on revision rates, specific complications, and functional scores. We pooled results across studies using a random-effects method, using proportions for dichotomous data and mean values for functional scores. We analyzed outcomes by indication and specific implant.

Results

We included 31 studies. Studies included patients with radial head fractures only, terrible-triad injuries, or Essex-Lopresti injuries or included a heterogeneous population. We identified 15 different fixed-stem implants. The results of our analysis revealed that patients with terrible-triad injuries may be at an increased risk of revision and instability and patients with Essex-Lopresti injuries may be at an increased risk of arthritis, capitellar erosion, and osteolysis. After removing these outliers and pooling the results by specific device, we observed variability across devices in the rates of revision, arthritis, capitellar erosion, instability, and osteolysis, as well as in functional scores.

Conclusion

Differences were seen across different implants in revision rates, certain complications, and functional scores. This study highlighted that these devices should be evaluated within the context of the patient population under examination, as patients with Essex-Lopresti or terrible-triad injuries may demonstrate worse outcomes relative to those with a fracture only.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Computed Tomography Analysis of the Radial Notch of the Ulna

PURPOSE

The anatomy of the radial head and capitellum has been extensively studied; however, the anatomy of the radial notch of the ulna (RNU) has received little attention. This imaging-based anatomic study characterizes the morphology of the RNU.

METHODS

Ninety-eight cadaveric arms (57 male, 72 ± 14 y) were imaged with computed tomography, and 3-dimensional reconstructions of the proximal ulna were constructed. The anteroposterior and proximal-distal dimensions of the RNU as well as the radius of curvature at standardized levels were measured in 2-mm increments. The orientation of the RNU was also determined.

RESULTS

The proximal-distal and anteroposterior dimensions of the RNU were 12 ± 2 mm (range, 7-16 mm) and 18 ± 3 mm (range, 12-24 mm), respectively. The average radius of curvature of the RNU was 15 ± 0 mm (range, 15-16 mm). The radius of curvature did not change significantly when comparing the proximal and distal aspect of the RNU. The RNU was rotated 33° ± 2° (range, 31° to 38°) externally relative to the transverse plane of the ulna. The average depth of the RNU at its deepest point was 2.2 ± 0.4 mm (range, 1.5-2.7 mm). The depth decreased from proximal to distal, being most shallow distally. The depth changed by an increase of the radius of curvature, as well as by rotation in the frontal plane.

CONCLUSIONS

The RNU anatomy was variable, generally extending laterally from proximal to distal. This suggests that a radial head implant should taper from proximal to distal to optimize contact at the RNU.

CLINICAL RELEVANCE

The present study investigates the detailed anatomy of the radial notch of the ulna using computed tomography scans. The data might help improve the design of prosthetic components.

Surgical treatment of radial head isolated Mason III fractures

INTRODUCTION

In this retrospective study we have analyzed a consecutive series of patients affected by isolated radial head Mason III fractures and treated with bone resection or prosthesis.

PATIENTS AND METHODS

This study includes 24 patients affected by fractures mentioned above and treated between July 2009 and November 2015. 15 patients (average age 48 y.o.) have been treated with prosthesis. The remaining 9 (average age 573) have been treated with a capitellectomy instead. From a clinical point of view, we have evaluated the patients according to main performance indicators such as range of motion, pain, instability and Mayo Elbow Performance Score as parameters.

RESULTS

We have found similar results in both group, with an average MEPS value of 95 in the prosthesis group and 966 in the radial head resection group. The range of motion was similar too: between 1,3° and 1203° in the first group and between 4,4° and 120° in the second one. No significant complication has detected in any patient.

DISCUSSION

According to most recent literature, it is not precisely defined how to treat isolated Mason III fractures, contrary to what is defined in more complex pattern, in which prosthesis are now evaluated as the best indication. Due to radial head limited contribution to elbow stability, in absence of other bony or ligamentous lesions both capitellectomy and prosthesis can be good treatment in this kind of fracture.

CONCLUSION

According to our experience and to the most recent literature, we recommend prosthesis in patient younger than 50 y.o., high demanding or manual worker, while in other cases we think that radial head resection can be the treatment of choice.

Primary cemented bipolar radial head prostheses for acute elbow injuries with comminuted radial head fractures: mid-term results of 37 patients

BACKGROUND

Radial head arthroplasty represents a widely accepted treatment for elbow injuries with non-reconstructible radial head fractures. The aim of this retrospective multicenter study was to assess mid-term results of patients with clearly defined elbow injuries including type III fractures of the radial head according to Mason's classification type III after primary arthroplasty using a cemented bipolar design.

MATERIALS AND METHODS

In 45 cases a primary cemented bipolar arthroplasty of the radial head was implanted for elbow injuries combined with an acute Mason type III radial head fracture. In all patients associated fractures were detected with preoperative CT scans and ligamentous injuries were evaluated and both were addressed intraoperatively based on a standardized algorithm. Patients with associated injuries other than coronoid fractures and collateral ligament tears were excluded from this study to obtain a more homogenous sample. Clinical and radiological assessment was performed on thirty-seven patients at an average of 5.6 years postoperatively.

RESULTS

DASH Score, functional rating index of Broberg and Morrey, Mayo Elbow Performance Score, and Mayo Modified Wrist Score confirmed good-to-excellent results in most of the patients. Compared to the unaffected arm range of motion and grip strength were slightly reduced. No elbow instability or loosening of the prosthesis, and minor degenerative changes were detected in a few cases.

CONCLUSION

Primary cemented bipolar arthroplasty for type III fractures according to Mason's classification in an elbow injury pattern only including associated coronoid fractures and/or ligamentous tears resulted in good-to-excellent mid-term results. These results suggest that primary bipolar radial head arthroplasty combined with distinct treatment of all associated injuries provides good functional outcomes concerning range of motion, elbow stability, and strength in this cohort. However, the associated injuries may influence clinical and radiological outcome and need to be detected, classified, and treated carefully.

WITHDRAWN: Surgical treatment of radial head isolated Mason III fractures

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Injury, 50(2) 2019 382–385, https://doi.org/https://doi.org/10.1016/j.injury.2018.11.044. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

IV retrospective case series.

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.

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

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

Clinical and Radiographic Outcomes of Unipolar and Bipolar Radial Head Prosthesis in Patients with Radial Head Fracture: A Systemic Review and Meta-Analysis

PURPOSE

To compare clinical outcomes of unipolar and bipolar radial head prosthesis in the treatment of patients with radial head fracture.

MATERIALS AND METHODS

Medline, Cochrane, EMBASE, Google Scholar databases were searched until April 18, 2016 using the following search terms: radial head fracture, elbow fracture, radial head arthroplasty, implants, prosthesis, unipolar, bipolar, cemented, and press-fit. Randomized controlled trials, retrospective, and cohort studies were included.

RESULTS

The Mayo elbow performance score (MEPS), disabilities of the arm, shoulder, and hand (DASH) score, radiologic assessment, ROM, and grip strength following elbow replacement were similar between prosthetic devices. The pooled mean excellent/good ranking of MEPS was 0.78 for unipolar and 0.73 for bipolar radial head arthroplasty, and the pooled mean MEPS was 86.9 and 79.9, respectively. DASH scores for unipolar and bipolar prosthesis were 19.0 and 16.3, respectively. Range of motion outcomes were similar between groups, with both groups have comparable risk of flexion arc, flexion, extension deficit, rotation arc, pronation, and supination (p values <0.001 for both unipolar and bipolar prosthesis). However, bipolar radial head prosthesis was associated with an increased chance of heterotopic ossification and lucency (p values ≤0.049) while unipolar prosthesis was not (p values ≥0.088). Both groups had risk for development of capitellar osteopenia or erosion/wear (p values ≤0.039).

CONCLUSION

Unipolar and bipolar radial head prostheses were similar with respect to clinical outcomes. Additional comparative studies are necessary to further compare different radial head prostheses used to treat radial head fracture.

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.

Effect of Concomitant Elbow Injuries on the Outcomes of Radial Head Arthroplasty: A Cohort Comparison

OBJECTIVES

To compare physical impairments and patient-reported outcomes in patients after simple and complex elbow injuries who were treated with radial head arthroplasty.

DESIGN

Prospective.

SETTING

Quaternary upper extremity referral hospital.

PATIENTS/PARTICIPANTS

148 patients with isolated elbow trauma and no previous injury to the elbow were prospectively enrolled after radial head arthroplasty for an acute unreconstructable fracture. Injury patterns were classified as simple or complex based on the presence or absence of associated elbow fractures and/or dislocation.

INTERVENTION

Radial head arthroplasty.

MAIN OUTCOME MEASUREMENTS

Patient-Rated Elbow Evaluation (PREE), Disability of the Arm, Shoulder, and Hand, range of motion (ROM), and Biodex measurements.

RESULTS

At a minimum 1-year follow-up PREE and Disability of the Arm, Shoulder, and Hand, and ROM and strength values were similar. Forty-four patients evaluated at a mean of 7 years demonstrated no effect of injury pattern on clinical outcomes at any time point. Continued statistical improvements in PREE, supination ROM, and flexion ROM at medium term compared with earlier follow-up were observed. Eight patients required secondary surgery, 2 in the simple injury group and 6 complex injury patients.

CONCLUSIONS

Concomitant elbow injuries do not affect the longer term outcomes of patients with unreconstructable radial head fractures requiring radial head arthroplasty. Patient outcomes continued to improve beyond 2 years of follow-up.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Tight-fitting radial head prosthesis: does stem size help prevent painful loosening?

INTRODUCTION

The most common reason for removal of well-fixed radial head prostheses is painful loosening. We hypothesised that short-stemmed prostheses, used for radial head arthroplasty, are not associated with an increased risk of implant loosening.

METHODS

From 2002 to 2014, 65 patients were enrolled in a retrospective single-centre study. The radial head prostheses were classified as having either a long (30-mm) or short (16- to 22-mm) stem. The long-stemmed implants comprised 30 GUEPAR® DePuy Synthes (West Chester, PA, USA) and 20 Evolutive® Aston Medical (Saint-Etienne, France) devices; the short-stemmed implants comprised nine RECON and six STANDARD rHead® SBI-Stryker (Morrisville, PA, USA) devices. At last follow-up, clinical (range of motion, Disabilities of the Arm, Shoulder, and Hand score, Mayo Elbow Performance score) and radiographic (osteolysis) outcomes were assessed.

RESULTS

At a mean follow-up of 76.78 months (24-141), the rate of painful loosening [6 (40%) vs 8 (16%), p = 0.047] and osteolysis [12 (80%) vs 23 (46%), p = 0.02] were significantly higher in patients with short-stemmed versus long-stemmed implants. Despite the significant difference in loosening between stems as groups, individual stem length was not determined.

CONCLUSIONS

Tight-fitting implants with short stems are more prone to painful loosening.

Mid-term outcomes of 77 modular radial head prostheses

AIMS

Radial head arthroplasty (RHA) may be used in the treatment of non-reconstructable radial head fractures. The aim of this study was to evaluate the mid-term clinical and radiographic results of RHA.

PATIENTS AND METHODS

Between 2002 and 2014, 77 RHAs were implanted in 54 men and 23 women with either acute injuries (54) or with traumatic sequelae (23) of a fracture of the radial head. Four designs of RHA were used, including the Guepar (Small Bone Innovations (SBi)/Stryker; 36), Evolutive (Aston Medical; 24), rHead RECON (SBi/Stryker; ten) or rHead STANDARD (SBi/Stryker; 7) prostheses. The mean follow-up was 74.0 months (standard deviation (sd) 38.6; 24 to 141). The indication for further surgery, range of movement, mean Mayo Elbow Performance (MEP) score, quick Disabilities of the Arm, Shoulder and Hand (quickDASH) score, osteolysis and positioning of the implant were also assessed according to the design, and acute or delayed use.

RESULTS

The mean MEP and quickDASH scores were 90.2 (sd 14; 45 to 100), and 14.0 points (sd 12; 1.2 to 52.5), respectively. There were no significant differences between RHA performed in acute or delayed fashion. There were 30 re-operations (19 with, and 11 without removal of the implant) during the first three post-operative years. Painful loosening was the primary indication for removal in 14 patients. Short-stemmed prostheses (16 mm to 22 mm in length) were also associated with an increased risk of painful loosening (odds ratio 3.54 (1.02 to 12.2), p = 0.045). Radiocapitellar instability was the primary indication for re-operation with retention of the implant (5). The overall survival of the RHA, free from re-operation, was 60.8% (sd 5.7%) at ten years.

CONCLUSION

Bipolar and press-fit RHA gives unsatisfactory mid-term outcomes in the treatment of acute fractures of the radial head or their sequelae. The outcome may vary according to the design of the implant. The rate of re-operation during the first three years is predictive of the long-term survival in tight-fitting RHAs. Cite this article: Bone Joint J 2017;99-B1197-1203.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

MATERIAL AND METHODS

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

RESULTS

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

DISCUSSION

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

LEVEL OF EVIDENCE

Therapeutic IV.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III Prognostic.

Radial head replacement in adults with recent fractures

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

One-year results of cemented bipolar radial head prostheses for comminuted radial head fractures

INTRODUCTION

Comminuted radial head fractures (Mason type III) continue to pose a challenge to orthopedic surgeons. When internal fixation is not possible, radial head arthroplasty has been advocated as the treatment of choice. The purpose of this retrospective study was to evaluate clinical and radiological short-term results of patients with Mason type III radial head fractures treated with a cemented bipolar radial prosthesis.

METHODS

Twelve patients received cemented bipolar radial head hemiarthroplasty for comminuted radial head fractures. In all patients a CT scan was obtained prior to surgical treatment to assess all associated injuries. Postoperatively an early motion protocol was applied. All patients were evaluated clinically and radiologically at an average of 12.7 months.

RESULTS

According to the Mayo Modified Wrist Score, the Mayo Elbow Performance Score, the functional rating index of Broberg and Morrey, and the DASH Score good to excellent results were obtained. Grip strength and range of motion were almost at the level of the unaffected contralateral side. Patient satisfaction was high, no instability or signs of loosening of the implant, and only mild signs of osteoarthritis were seen.

CONCLUSION

Overall good to excellent short-term results for primary arthroplasty for comminuted radial head fractures were observed. These encouraging results warrant the conduction of further studies with long-term follow-up and more cases to see if these short-term results can be maintained over time.

Complications of radial head prostheses

Radial head prostheses are indicated for treatment of complex radial head fractures not amenable for fixation. After the initial experience with silastic implants, metallic or pyrocarbon arthroplasty have been used for 20 years. Little is known about complications related to these implants. Main complications are related to loosening whether they are cemented or not cemented. Hypotheses have been proposed like inadequate stem design, insufficient cement technique, stress shielding, and foreign body reactions secondary to polyethylene wear. Pain and stiffness are other common complications often related to oversized radial head component or overstuffing of the joint with excessive lengthening of the radius. Instability can be another complication in the context of more complex trauma with lateral collateral ligament complex lesion and coronoid fracture. Fixation of the coronoid fracture, reinsertion of the lateral collateral ligament complex, and the use of monobloc radial head prosthesis are recommended to stabilize the joint. Finally, osteoarthritis is common with follow-up.