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

Short- to midterm outcomes of 139 pyrocarbon monopolar radial head arthroplasties

BACKGROUND

The MoPyc radial head arthroplasty (RHA) is a monopolar implant with a pyrocarbon head that obtains rigid fixation via controlled expansion of the titanium stem. The aim of this study was to evaluate the short-term to midterm outcomes of MoPyc RHA.

MATERIALS AND METHODS

Between 2002 and 2021, 139 MoPyc RHA were implanted in 139 patients with a RH fracture. The mean follow-up was 5.9 years ± 3.5 (range 1-16). Range of motion, mean Mayo Elbow Performance Score (MEPS), Quick Disabilities of the Arm, Shoulder and Hand score, visual analog scale (VAS), radiographic outcome, and reason for failure were recorded.

RESULTS

The mean MEP, Quick Disabilities of the Arm, Shoulder and Hand, and VAS scores were 89.1 ± 2.2 (range, 45-100), 17.5 ± 16.7 (range, 0-78), and 0.8 ± 1.6 (range, 0-50), respectively. Stress shielding (SS) and osteolysis around the stem were identified in 92 (66%) and 20 (14%) patients. A total of 47 (29%) patients experienced at least 1 complication and 29 (21%) of them required re-intervention. Persistent stiffness (n = 12; 9%) was the most common complication. No painful loosening was noted. Osteolysis around the stem, presence of an autoexpanding stem, and overstuffing were associated with a lower MEPS and an increase in VAS (P < .05). SS was associated with an increase in MEPS (adjusted beta coefficients= 6.92; P < .001) and lower VAS (adjusted beta coefficients= -0.69; P = .016). The autoexpending stem increased the likelihood of SS after RHA (adjusted odds ratio = 1.49; P = .001).

CONCLUSIONS

A well-fixed MoPyc RHA provided satisfactory short to midterm outcomes, without painful loosening. However, the autoexpanding stem system was associated with poorer functional outcomes and increased the likelihood of SS.

Stress shielding following radial head arthroplasty: the impact of preoperative bone quality

BACKGROUND

We sought to assess if the medullary diameter to cortical width ratio (MD:CW), canal flair index (CFI), and canal fill (CF) of the proximal radius were associated with the presence of stress shielding (SS) after a MoPyC radial head arthroplasty.

MATERIALS AND METHODS

We conducted a retrospective, international, multicenter (4 centers) study. A total of 100 radial head arthroplasties in 64 women and 36 men with a mean age of 58.40 years ± 14.90 (range, 25.00-91.00) were included. Radiographic measurements, including MD:CW, CFI, CF, and postoperative SS were captured at a mean follow-up of 3.9 years ± 2.8 (range, 0.5-11).

RESULTS

SS was identified in 60 patients. Mean preoperative MD:CW, CFI, and CF were 0.55 ± 0.09, 1.05 ± 0.18, and 0.79 ± 0.11, respectively. The presence of SS was significantly associated with MD:CW (adjusted odds ratio = 13.66; P = .001), and expansion of the stem (adjusted odds ratio = 3.78; P = .001). The amount of the SS was significantly correlated with expansion of the stem (aβ 4.58; P < .001).

CONCLUSIONS

Our study found that MD:CW was an independent risk factor of SS after MoPyc radial head arthroplasty. Autoexpansion of the MoPyc stem significantly increased the risk of SS and its extent. Further studies involving multiple implants designs are needed to confirm the preliminary observations presented in the current study.

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

INTRODUCTION

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

HYPOTHESIS

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

METHODS

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

RESULTS

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

DISCUSSION

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

LEVEL OF EVIDENCE

II; Systematic review.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pyrocarbon unipolar radial head prosthesis: clinical and radiologic outcomes at long-term follow-up

BACKGROUND

Several studies have already reported good short-term results with a pyrocarbon unipolar radial head prosthesis (Pyc-uRHP). The aim was to evaluate the evolution from mid- to long-term clinical and radiographic outcomes of a Pyc-uRHP.

METHODS

This was a retrospective, single-center study. We followed up all the patients who underwent Pyc-uRHP surgery in our original study at 2 years of follow-up (52 patients), reaching a minimum of 7 years of clinical and radiologic follow-up. This study included 26 patients who underwent a clinical examination assessing mobility, the Mayo Elbow Performance Score, and the visual analog scale score and radiologic evaluation with anteroposterior and profile radiographs at a mean follow-up of 110 months (range, 78-162 months). The radiologic study analyzed signs of proximal osteolysis, stem loosening, capitellar wear, and humeroulnar osteoarthritis.

RESULTS

No patients required revision. Eight patients required reoperation: coronoid screw removal in 1 and arthrolysis for stiffness in 7. The mean time to reoperation was 11 months. The mean Mayo Elbow Performance Score at last follow-up was 96 ± 9 (of 100), with a pain score of 42 ± 7 (of 45), mobility score of 19 ± 2 (of 20), stability score of 10 (of 10), and function score of 25 (of 25). Comparison with clinical data from the mid-term delay did not reveal any significant difference. All patients presented with proximal osteolysis around the neck but without progression. No stem loosening was noted. The rates of humeroulnar osteoarthritis (12% at mid-term vs. 80% at last follow-up, P < .0001) and capitellar lesions (34% at mid-term vs. 80% at last follow-up, P = .001) increased significantly.

CONCLUSION

We have shown that a Pyc-uRHP at 9 years' follow-up provided stable and satisfactory clinical results. Osteolysis of the radial neck was always present but it did not evolve, and no stem loosening was noted. Finally, we have shown a clear worsening of radiologic humeroulnar osteoarthritis and capitellar lesions that remained asymptomatic.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III Retrospective comparative treatment study.

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.

Evaluation of two different types of radial head prosthesis in practical use. Using either Evolve® or MoPyC® radial head prosthesis in the treatment of comminuted radial head fractures

The aim of this retrospective study was to undertake a comparative evaluation of the Evolve^® modular metallic radial head implant prosthesis and the MoPyC^® pyrocarbon prosthesis in acute care. Seventyfive patients having a comminuted radial head fracture with an Evolve^® prosthesis (=G1) and 11 with a MoPyC^® prosthesis (=G2) were available for a follow-up. Postoperative patient outcomes were evaluated according to a standardized follow-up protocol which included the Morrey rating system. Assessment criteria were range of motion (ROM), functional scores, and rate of complications. G1 showed a mean Morrey score of 86 points. Four direct prosthesis complications were observed in this group (n=75). The average achieved Morrey score in G2 was 84 points. In this group (n=11), 2 direct prosthesis complications were diagnosed. The average range of motion did not differ greatly between both groups. Radial head replacement with either prosthesis yielded sufficient to satisfactory results in a mid-term perspective regarding the range of motion and function of the elbow joint when performed in carefully selected patients. The Evolve^® Prothesis appears to show a slightly lower rate of complication by way of a similar functional outcome.

Surgical treatment of the radial head is critical to the outcome of Monteggia-like lesions

Aims

The aim of this study was to evaluate the outcome of Monteggia-like lesions at midterm follow-up and to determine whether the surgical treatment of the radial head influences the clinical and radiological results.

Patients and Methods

A total of 78 patients with a Monteggia-like lesion, including 44 women and 34 men with a mean age of 54.7 years (19 to 80), were available for assessment after a mean 4.6 years (2 to 9.2). The outcome was assessed using the Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), Mayo Modified Wrist Score (MMWS), and The Disabilities of the Arm, Shoulder and Hand (DASH) score. Radiographs were analyzed for all patients. A total of 12 Mason type I, 16 type II, and 36 type III fractures were included. Surgical treatment consisted of screw fixation for all type II and reconstructable type III fractures, while radial head arthroplasty (RHA) or excision was performed if reconstruction was not possible.

Results

The mean MEPS was 88.9 (40 to 100), mean OES was 40.1 (25 to 48), mean MMWS was 88.1 (50 to 100), mean DASH score was 14.7 (0 to 60.2), and mean movement was 114° (sd 27) in extension/flexion and 155° (sd 37) in pronation/supination. Mason III fractures, particularly those with an associated coronoid fracture treated with RHA, had a significantly poorer outcome. Suboptimal results were also identified in patients who had degenerative changes or heterotopic ossification on their latest radiograph. In contrast, all patients with successful radial head reconstruction or excision had a good outcome.

Conclusion

Good outcomes can be achieved in Monteggia-like lesions with Mason II and III fractures, when reconstruction is possible. Otherwise, RHA is a reliable option with satisfactory outcomes, especially in patients with ligamenteous instability. Whether the radial head should be excised remains debatable, although good results were achieved in patients with ligamentous stability and in those with complications after RHA. Cite this article: Bone Joint J 2019;101-B:1512–1519

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

BACKGROUND

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

QUESTIONS/PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level IV, therapeutic study.