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

Reported outcome measures in complex fracture elbow dislocations: a systematic review

BACKGROUND

Complex elbow fracture dislocations, dislocation with fracture of one or several surrounding bony stabilizers, are difficult to manage and associated with poor outcomes. While many studies have explored treatment strategies but a lack of standardization of patient-reported outcome measures (PROMs) makes cross-study comparison difficult. In this systematic review, we aim to describe what injury patterns, measured outcomes, and associated complications are reported in the complex elbow fracture dislocation literature to provide outcome reporting recommendations that will facilitate improved future cross-study comparison.

METHODS

A systematic review was performed per Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify articles published between 2010 and 2022 reporting on adult patients who had a complex elbow fracture dislocation. Pathologic fractures were excluded. A bias assessment using the methodological index for nonrandomized studies criteria was conducted. For each article, patient demographics, injury pattern, outcome measures, and complications were recorded.

RESULTS

Ninety-one studies reporting on 3664 elbows (3654 patients) with an elbow fracture and dislocation (weighted mean age 44 years, follow-up of 30 months, 41% female) were evaluated. Of these, the injury pattern was described in 3378 elbows and included 2951 (87%) terrible triad injuries and 72 (2%) transolecranon fracture-dislocations. The three most commonly reported classification systems were: Mason classification for radial head fractures, Regan and Morrey coronoid classification for coronoid fractures, and O'Driscoll classification for coronoid fractures. Range of motion was reported in 87 (96%) studies with most reporting flexion (n = 70), extension (n = 62), pronation (n = 68), or supination (n = 67). Strength was reported in 11 (12%) studies. PROMs were reported in 83 (91%) studies with an average of 2.6 outcomes per study. There were 14 outcome scores including the Mayo Elbow Performance Score (n = 69 [83%]), the Disabilities of Arm, Shoulder and Hand (DASH) score (n = 28 [34%]), the visual analog scale for pain (n = 27 [33%]), QuickDASH score (n = 13 [15.7%]), and Oxford Elbow score (n = 5 [6.0%]). No significance was found between the number of PROMs used per article and the year of publication (P = .313), study type (P = .689), complex fracture pattern (P = .211), or number of elbows included (P = .152).

CONCLUSION

There is great heterogeneity in reported PROMs in the complex elbow fracture dislocation literature. Although there is no gold standard PROM for assessing complex elbow fracture dislocations, we recommend the use of at least the Mayo Elbow Performance Score and DASH outcomes measures as well as visual analog scale pain rating scale in future studies to facilitate cross-study comparisons.

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.

[Terrible triad injuries]

The complex injury pattern of a posterior elbow dislocation with concomitant radial head and coronoid fractures is usually referred to as a terrible triad injury. Due to the concomitant compromise of several osteoligamentous structures of the elbow joint relevant for stability, these injuries pose a particularly major challenge to the treating trauma surgeons. For this reason, a careful preoperative analysis of all relevant injury components is mandatory in order to make an adequate treatment decision. In most cases, surgical treatment addressing all elements relevant for stability is necessary to achieve a stable and congruent elbow joint. Only this enables early functional follow-up treatment and minimizes the complication rate. Delayed or even insufficient treatment with persistent (sub)dislocation must be avoided at all costs, otherwise there is a high risk of serious posttraumatic functional disorders of the elbow with rapid progression of osteoarthritis.

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 Arthroplasty for Fracture: Implant Survivorship and Outcomes at Mean Follow-up of 8 Years

PURPOSE

The purpose of this study was to evaluate implant survivorship and clinical outcomes following radial head arthroplasty for fracture at long-term follow-ups.

METHODS

A retrospective analysis was conducted on adult patients who underwent primary uncemented radial head arthroplasty for radial head or neck fractures between 2012 and 2015. Medical records were reviewed to collect information regarding demographics, injury characteristics, reoperations, and revisions requiring implant removal. A bivariate analysis was conducted to identify potential risk factors for reoperation. A Kaplan-Meier curve was created to determine implant survival rates. Eligible patients were contacted to confirm any reoperations and obtain Quick Disability of the Arm, Shoulder, and Hand scores at long-term follow-ups.

RESULTS

A total of 89 patients were eligible for analysis and assessed at a mean of 97 months after surgery (range, 81-128). Reoperation rate was 16% (14 of 89 patients), including 5% of patients requiring implant removal or revision. However, 93% of reoperations occurred within the first 12 months of the index surgery. Fracture dislocations of the elbow had a higher rate of reoperation. A Kaplan-Meier curve demonstrated an implant survival rate of 96% at 10-year follow-up. Of the patients who responded, the mean Quick Disability of the Arm, Shoulder, and Hand score was 8.7 ± 10.3, with none requiring additional reoperations or revisions. There were otherwise similar outcome scores among patients requiring reoperation versus those who did not.

CONCLUSIONS

Although radial head arthroplasty for fractures has a high potential for reoperation within the first year, survival rates with uncemented implants remain high at 10 years, and patients report excellent Quick Disability of the Arm, Shoulder, and Hand scores at long-term follow-ups, despite any need for reoperation. Fractures with associated elbow dislocation may be at a higher risk for reoperation, and it is important to provide this prognostic information to patients who are likely to require arthroplasty for more extensive injuries.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Early aseptic loosening of a press-fit radial head prosthesis - A case series of 6 patients

OBJECTIVE

Radial head arthroplasty (RHA) is the principal treatment option for comminuted radial head (RH) fractures. Here, we present six cases of failed RHA using a modular monopolar press-fit RHA that was subsequently withdrawn from the market because it was associated with a high incidence of loosening.

METHODS

We retrospectively collected data from six patients who had received Radial Head Prothesis System^TM at our centre between July 2015 and June 2016. The average follow-up was 40 months.

RESULTS

Aseptic loosening of the stem affected five (83%) of the six RHA. Four of these were symptomatic and RHA removal was performed. For these patients, the pain subsided and their elbow range of motion (ROM) improved.

CONCLUSION

While the ideal design for an RHA is still debatable, RHA is an efficient treatment option that restores elbow stability and function after a comminuted RH fracture. Importantly, removal of the prosthesis is an effective remedy following RHA associated elbow pain and decreased ROM.

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.

A systematic review and meta-analysis on different stem fixation methods of radial head prostheses during long-term follow-up

Background: Radial head arthroplasty (RHA) is typically performed for non-reconstructible radial head fractures with or without valgus stability. The fixation methods can be divided into cemented rigid fixation, such as screw fixation, and uncemented micromovement fixation, including smooth stem, press-fit, expanded device, in-growth stem, and grit-blasted stem fixations. Different fixation methods may impact long-term clinical outcomes and cause complications. This study aimed to compare the long-term follow-up outcomes of cemented and uncemented radial head prostheses. Methods: A computerized literature search was performed in the PubMed/MEDLINE, Embase, Cochrane Library, and Web of Science databases for studies on radial head prostheses, replacement, and arthroplasty published from inception to April 2022. The prostheses fixation method was divided into cemented and uncemented fixation groups. The outcomes of interest included the participant characteristics, prostheses types, clinical outcomes, reoperation rates, and complication rates during long-term follow-up. Results: A total of 57 studies involving 2050 patients who underwent RHA were included in our analysis. Cemented fixation was used in 23 of these studies, uncemented fixation in 35 studies, and both cemented and uncemented fixations in one study. Both fixation groups showed significantly improved clinical outcomes after treatment. In particular, both the reoperation and complication rates were lower in the uncemented fixation group (12% and 22%, respectively) than that in the cemented fixation group (20% and 29%, respectively). Among the studies, uncemented monopolar fixation had the lowest reoperation rate (14%), while cemented monopolar fixation had the highest reoperation rate (36%). Regarding complication rates, uncemented bipolar fixation yielded the lowest rate (12%), while cemented bipolar fixation yielded the highest rate (34%). The range of motion and clinical outcome scores were good in both groups. Conclusion: Uncemented radial head prostheses had lower reoperation and complication rates than cemented prostheses. In particular, uncemented monopolar prostheses may yield the lowest reoperation rate, while uncemented bipolar prostheses may yield the lowest overall complication rate.

Essex-Lopresti Lesions and Longitudinal Radioulnar Instability: A Narrative Review

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An Essex-Lopresti injury (ELI) is classically described as a radial head fracture with a concomitant interosseous ligament complex (IOC) injury. However, multiple injury patterns may be present, and an interosseous membrane (IOM) injury should be evaluated for in any axial load injury through the forearm. ELI may result in longitudinal radioulnar instability (LRUI).

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Diagnosis of an IOC injury can be difficult. Evaluation begins with standard wrist and elbow radiographs and is supplemented with radiographs and intraoperative maneuvers to assess for proximal radial migration. Magnetic resonance imaging and ultrasonography may be useful in the acute setting, although indications and the clinical importance of the findings remain unclear.

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Surgical management of an acute ELI is focused on restoration of radial length and temporary distal radioulnar joint (DRUJ) stabilization. Radial head excision in the acute setting should be approached with caution because proximal migration may not be present acutely but may develop over time. The indication for acute IOM repair and reconstruction remains unclear.

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Surgical management of a chronic ELI is focused on restoration of radial length, wrist leveling, and treatment of degenerative changes (either at the radiocapitellar joint or the DRUJ). Reconstruction of the central band can restore forearm load transfer and produce favorable functional outcomes, but its indications continue to be debated.

Efficacy and safety of monopolar versus bipolar radial head arthroplasty: a systematic review and meta-analysis

BACKGROUND

Radial head replacement is the main line of treating complex unstable elbow injuries. Radial head prostheses are either monopolar or bipolar. The difference between both designs in patients' clinical outcomes and postoperative complications is not yet clear. So, a systematic review and meta-analysis was conducted to evaluate the efficacy and safety of monopolar vs. bipolar implants.

MATERIALS AND METHODS

PubMed, EMBASE, Cochrane, and Scopus were searched to identify studies comparing monopolar and bipolar implants. Data on clinical outcomes, postoperative complications, revision, and removal rates were extracted.

RESULTS

Nine studies met our inclusion criteria, with a total of 591 patients (365 monopolar and 226 bipolar). Both prostheses achieved similar ranges of motion; Mayo Elbow Performance Score; Disabilities of the Arm, Shoulder, and Hand score; and visual analog scale for pain. Incidence of postoperative complications was also similar between both designs. Revision and removal rates were 24%, 8% and 29%, 14% for monopolar and bipolar implants, respectively, but no statistically significant difference could be detected.

CONCLUSIONS

No significant difference was found between monopolar and bipolar radial head prostheses in terms of efficacy and safety. Therefore, high-quality randomized controlled trials are required to determine the superiority of one design over the other.

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.

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.

Prognostic factors for traumatic elbow osteoarthritis after terrible triad surgery, and functional impact

INTRODUCTION

Terrible triad (TT) of the elbow almost always requires surgery to prevent progression to chronic instability and more or less inevitable osteoarthritis. Progression toward osteoarthritis after well-conducted surgery and associated risk factors have been little reported. We performed a retrospective study: (1) to assess rates of post-traumatic elbow osteoarthritis after surgical treatment of TT; (2) to assess functional impact; and (3) to identify prognostic factors.

HYPOTHESIS

Prevalence of osteoarthritis after surgical treatment of TT is high, impairing functional results.

MATERIAL AND METHOD

A single-center retrospective study included 53 patients, with a mean age of 50±17.8 years (range, 21-84 years), undergoing surgery for acute TT in our department. All received clinical examination with ranges of motion and Mayo Elbow Performance Index (MEPI) and radiographic assessment at a minimum 1 year's follow-up. Osteoarthritis at last follow-up was assessed on elbow X-ray in the humero-ulnar and radio-condylar compartments on the Broberg-Morrey classification. Functional impact on range of motion and MEPI and prognostic factors were assessed on Student test or ANOVA and Chi² or Fisher test.

RESULTS

Prevalence of Broberg-Morrey grade 2 or 3 osteoarthritis was 45.3% (24/53) in the humero-ulnar compartment and 50% (25/50) in the radio-condylar compartment. Humero-ulnar osteoarthritis impaired MEPI (76.3 points with versus 88.4 points without; p=0.003), flexion-extension (102.3° versus 115.2°; p=0.043) and pronation-supination (138.8° versus 159.3°; p=0.006). Radio-condylar osteoarthritis had no significant impact on MEPI (81.4 points with and 84.4 points without; p=0.47), flexion-extension (104.8° and 113°; p=0.23) or pronation-supination (141.8° and 156.4°; p=0.2). Humero-ulnar osteoarthritis at last follow-up was associated with dislocation or subluxation on immediate postoperative lateral view (45.8% with versus 10.3% without; p=0.004) and at last follow-up (20.8% versus 3.4%; p=0.047) and with postoperative complications (54.2% and 27.6%; p=0.049). Radio-condylar osteoarthritis at last follow-up was associated with radial head replacement rather than internal fixation (respectively, 92% and 48%; p=0.0007) and excessively high radial head implant positioning (47.8% versus 0%; p=0.023).

CONCLUSION

Prevalence of traumatic osteoarthritis after TT surgery was high, at 45.3% in the humero-ulnar compartment and 50% in the radio-condylar compartment, with clinical impact in humero-ulnar involvement.

LEVEL OF EVIDENCE

IV; cohort study without control group.

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.