Radial Head Replacement Research Articles

Pathophysiology of longitudinal forearm instability (Essex-Lopresti syndrome) and implications for treatment.

Longitudinal forearm instability, or Essex-Lopresti syndrome, associates radial head fracture and rupture of the structures uniting the 2 bones, mainly the interosseous membrane and triangular fibrocartilage complex adjacent to the distal radioulnar joint. It is often overlooked at first, and should be screened for in case of comminuted radial head fracture without elbow dislocation or instability. Treatment should be prompt, within 4 weeks of trauma, to avoid soft-tissue retraction and hopefully allow healing. This interval is anecdotal, without firm evidence, but matches observations regularly reported in the literature [1]. In the acute phase, treatment consists in rigid, usually unipolar, radial head replacement, protected healing of the interosseous membrane by a TightRope suture button between the bones, radioulnar pinning and triangular fibrocartilage complex suture, followed by 6 weeks' immobilization. Progression is usually favorable. Chronic forms, beyond 4 weeks, when soft-tissue healing is impossible, require interosseous membrane reconstruction. In case of radiocarpal impingement due to ascension of the radius, ulnar shortening osteotomy must be associated. Medium-term results in such cases are much less certain. As a last resort, the "one-bone forearm" is a solution.

Outcome of radial head and neck fractures with radial head replacement

Outcome of radial head and neck fractures with radial head replacement

Replacement of radial head versus reconstruction terrible triad elbow injury

The extraordinarily congruous nature of the joint and the interaction between the articular surfaces and soft-tissue stabilisers are the two factors that contribute to the stability of a normal elbow. A profoundly unstable elbow is the outcome of TTIE, which is characterised by the loss of the anterior coronoid buttress, the posterolateral stabilisation of the lateral ulnar collateral ligament (LUCL), and the valgus buttress of the radial head. This study aims to compare and evaluate the outcomes of patients who received radial head reconstruction (REC) or replacement (REP) following a TTIE in order to see if there are any changes in patient outcomes between the two treatment groups.

Radial Head Replacement: Management of Elbow and Forearm Instability after Comminuted Radial Head Fractures Associated with Elbow Dislocation

This manuscript aims to identify an indication algorithm for the surgical treatment of radial head fractures associated with elbow dislocation. The study compares the mid-term functional outcomes of patients with multifragment radial head fracture treated by resection with the outcomes of patients treated with radial head replacement. The cohort of 34 patients who sustained a radial head fracture at the mean age of 42.5 years (age range 20-81 years) was broken down into two groups by type of surgery. The EXT group consists of 20 patients with the radial head fracture treated by radial head resection. The END group includes 14 patients treated with the radial head replacement. In all patients, the radial head fracture was associated with elbow dislocation (type IV fracture according to the Mason-Johnston classification). The modified Kocher's surgical approach was used in all patients of both the groups. In the EXT group, resection of the fragmented radial head was performed. In the END group, the ExploR® Modular Radial Head System (Zimmer, Biomet, USA) was used, consisting of a CoCr (cobalt chromium) alloy head and a titanium stem. The pain and the range of motion of the elbow and forearm were evaluated after the completion of the outpatient rehabilitation (the mean follow-up period was 2.4 years). Simultaneously, the elbow joint stability was assessed. Radiographs were taken to detect heterotopic ossifications, proximalization of the radius, and any signs of prosthesis loosening. The frequency of reoperations was followed-up. The MEPS (Mayo Elbow Performance Score) was calculated. In the EXT group, the mean elbow flexion was 117.5° and the mean pronation/supination was 166.9°. In 50% of patients, the MEPS obtained was greater than 90 points, which means an excellent functional outcome. In 1 patient (5%), recurrent elbow dislocation occurred which was the reason for revision surgery (elbow transfixation with the Kirschner wires and medial collateral ligament suture). Revision surgery was also performed in 2 patients (10%) in whom not all the radial head fragments were removed. Moreover, also observed was elbow joint instability (2 patients) and temporary radial nerve paralysis (1 patient). In 1 case discrete proximalization of the radius developed. The patients in the END group showed the mean elbow flexion of 112° and the mean pronation/supination of 135°. The MEPS obtained from 69% of patients was greater than 90 points, which means an excellent outcome. The pain under load was reported by 3 patients (21%). In 5 patients (35%), the X-rays showed radiolucent zone around the stem of the prosthesis. Neither revision surgery, nor prosthesis removal has been performed yet in any patient. No instability, neurological complications or infections have been reported. In both EXT and END group heterotopic ossifications have developed in 4 patients. Radial head replacement compared to the radial head resection in the management of multifragment fractures associated with elbow dislocations increase the elbow and forearm stability. The group of patients with an implanted radial head prosthesis shows a higher percentage of patients achieving excellent functional outcome than the group of patients with radial head resection. radial head, elbow, fracture, dislocation, resection, prosthesis.

Antibiotic-loaded spacer arthroplasty in a terrible triad injury with unreconstructable radial head fracture: a case report

BackgroundRadial head arthroplasty is a viable option in cases with terrible triad injuries of elbow, wherein the radial head sustains significant comminution that precludes reconstruction. Nevertheless, this alternative is not recommended for individuals with poor elbow skin conditions, accompanied neuropsychiatric disorders, or low patient compliance. This case report presents a patient with bilateral terrible triad injury, along with the aforementioned conditions. The report outlines the treatment challenges of such a case and proposes potential solutions.Case presentationA 37-year-old Persian male patient presenting with a bilateral terrible triad fracture–dislocation and a history of psychoactive substance abuse, was admitted to our emergency department. The patient underwent radial head replacement using a cement spacer containing antibiotics, due to the comminuted radial head in the presence of a contaminated wound on the left elbow. The fracture of the right side was successfully fixed. Subsequent to discharge, the patient did not attend any follow-up appointments. After a period of 6 months, he was admitted to the psychiatric ward and orthopedic consultation was requested to evaluate the patient.ConclusionIn acute terrible triad injuries with unreconstructable radial head fractures where arthroplasty with metallic prostheses may not be suitable due to contaminated wounds, unstable psychiatric condition, and low patient cooperation, temporary orthopedic cement spacers can maintain elbow biomechanics, stability, and sterility.

Radial head replacement for acute complex elbow instability: a long-term comparative cohort study of 2 implant designs.

Radial head fractures not amenable to reconstruction should be treated by radial head replacement (RHR) when there is associated elbow or forearm instability. There are multiple RHR designs with different philosophies, but 2 of the most commonly used implants include the anatomic press-fit radial head system and the loose-fit metallic spacer. There is little information available specifically comparing the long-term clinical and radiographic outcomes of these 2 systems. The objective of this study was to compare the long-term clinical and radiologic outcomes of 2 RHR designs in the context of complex acute elbow instability. Ninety-five patients with an average age of 54 years (range, 21-87 years) underwent an acute RHR (46 press-fit Acumed anatomic and 49 loose-fit Evolve metallic spacer) and were prospectively followed for an average of 61 months (range, 24-157 months). There were 34 terrible triads; 36 isolated RH fractures with medial, lateral, or longitudinal instability; and 25 RH fractures associated with a proximal ulnar fracture. Clinical outcome and disability were evaluated with the Mayo Elbow Performance Score (MEPS), the Oxford Elbow Score, and the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Pain and satisfaction were assessed using a visual analog scale. Radiographic analysis included presence of loosening, bone loss, and overstuffing related to the RHR. Eight patients with an anatomic RHR (2 with overstuffing, 3 for stiffness, and 3 with loose implants) and 1 patient with a spacer (with stiffness) required implant removal. There were no significant differences between spacer RHR and anatomic RHR in arc of motion (120° vs. 113°, P=.14), pain relief (1 vs. 1.7, P=.135), MEPS (94 vs. 88; P=.07), Oxford Elbow Score (42.3 vs. 42.2, P=.4), or DASH score (12.2 vs. 14.4, P=.5). However, patients with a spacer RHR were significantly more satisfied (9 vs. 7.7; P=.004) than those with an anatomic implant. Radiographically, 19 anatomic implants had significant proximal bone loss and 10 showed complete lucent lines around the stem. Lucent lines were common around the spacer RHR. These radiographic changes were not always related to worse clinical outcomes. Both the anatomic and spacer RHR designs can provide good clinical long-term outcomes. However, patients with a spacer showed a higher degree of satisfaction and those with an anatomic press-fit RHR had a higher revision rate, with radiographic changes that warrant continued follow-up.

Do Pyrocarbon Radial Head Replacements Offer Satisfactory Clinical and Radiological Outcomes? A Systematic Review

Do Pyrocarbon Radial Head Replacements Offer Satisfactory Clinical and Radiological Outcomes? A Systematic Review

Impact of Radiocapitellar Interposition Arthroplasty on Ulnohumeral Joint Biomechanics.

Radial head excision has been shown to increase contact pressures within the ulnohumeral joint. Radiocapitellar interposition arthroplasty with the use of a soft tissue graft is an alternative for the treatment of isolated radiocapitellar arthritis or with failure of radial head replacement. We investigated contact pressures and contact area within the ulnohumeral joint after radial head excision (RHE) compared to radiocapitellar interposition arthroplasty with dermal autograft (RCIA). Six fresh-frozen cadaver elbows were tested on a custom dynamic elbow frame. A pressure sensor was inserted into the intact elbow joint, and mean contact pressure, peak contact pressure, contact area, and force within the ulnohumeral joint were recorded at 0°, 30°, 60°, 90°, and 120° of flexion as a valgus load was applied to the elbow. The radial head was then excised and specimens were retested. Finally, a dermal graft matched to the size of the resected radial head was inserted in the radiocapitellar space and the specimens were tested a third time. At 90° of flexion, contact pressure within the ulnohumeral joint was significantly lower with RCIA compared with RHE (110.8 kPa vs. 216.8 kPa.; P = 0.013). Mean peak contact pressure was also significantly lower with RCIA compared with RHE at 90° (279.4 vs. 626.7 kPa; P =0.025). No statistically significant differences were seen in mean contact area or force between the three testing conditions at any flexion position. RCIA with a dermal graft reduced contact pressures within the ulnohumeral joint compared to radial head excision at 90° of flexion without a significant change in contact area or contact force.

A clinico-radiological study of radial head replacement vs excision in comminuted radial head fractures

A clinico-radiological study of radial head replacement vs excision in comminuted radial head fractures

A comparative study of outcome of radial head fracture treated with radial head replacement and radial head excision alone

: Radial head fractures are the most common fractures of the elbow with an estimated incidence of 2.5 to 2.9/10,000 people/ year. The incidence of radial head fractures is reported to be between 1.7 to 5.4 percent of all fractures. : This study aims to assess the clinical outcome of excision arthroplasty and prosthesis replacement in treatment of comminuted radial head fractures. : Patients with radial head fracture presenting to orthopaedics department and emergency room were included for the study. Excision arthroplasty was performed in 25 patients and replacement arthroplasty was performed in 25 patients. The functional outcome of both the procedure were compared using DASH, MEPS and Broberg and morrey scoring system. : Based on the DASH score Replacement group showed good improvement at the end of the 6 month follow-up with the mean score of 15.9 (P=0.042). Based on the MEPS score the mean MEPS score showed replacement group had a good improvement at the end of 6 month follow-up with the mean score of 15.9 (P=0.042). : From this study we concluded, radial head replacement is a reasonable option for unreconstructable radial head fractures. Radial head replacement can achieve effective radiocapitellar contact that will improve the stability in valgus, posterolateral, and axial loading of the forearm. This treatment option has satisfactory short- and mid-term results even with other combined elbow injuries.

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.

Effect of Radiocapitellar Joint Over/Under Stuffing on Elbow Joint Contact Pressure

Comminuted radial head fractures are commonly treated by surgical resection or replacement with a prosthesis. A potential problem with radial head replacement is overlengthening of the radial neck ("overstuffing" of the radial head), which has been shown to affect both ulnohumeral kinematics and radiocapitellar pressures. We hypothesized that an overstuffed radial head prosthesis increases capitellar pressure and reduces coronoid pressure. Seven human cadaveric elbows were prepared on a custom-designed apparatus simulating stabilizing muscle loads, and passively flexed from 0° to 90° under gravity valgus torque while joint contact pressures were measured. Each elbow was tested sequentially with different neck lengths, starting with the intact specimen followed by insertion of understuffed (-2 mm), standard-height (0 mm), and overstuffed (+2 mm) radial head prostheses in neutral forearm rotation, 40° pronation, and 40° supination positions, respectively. Capitellar mean contact pressures significantly increased after insertion of an overstuffed radial head prosthesis. In valgus position with neutral forearm rotation, capitellar mean contact pressure on the joint with an intact radial head averaged 227 ± 70 kPa. Insertion of understuffed, standard-height, and overstuffed radial head prostheses changed the mean contact pressures to 152 ± 76 kPa, 212 ± 68 kPa, and 491 ± 168 kPa, respectively. The overstuffed radial head group had significantly lower whole coronoid mean contact pressures (153 ± 56 kPa) compared with the intact (390 ± 138 kPa) and standard-height (376 ± 191 kPa) radial head groups. An increase in radial prosthesis height significantly increases capitellar contact pressures and reduces coronoid contact pressures. Restoration of the anatomic radial head height is critical when performing radial head arthroplasty to maintain normal joint biomechanics. Elevated capitellar contact pressures can potentially lead to pain and early degenerative changes.

Anthropometric Study of Proximal Radius in Below-Average Height Thai Women and Its Correlation with Commercially Available Radial Head Prostheses.

Background: Most radial head prostheses were designed in Western countries based on the anatomical characteristics of Western populations. We hypothesised that these prostheses are too large for below-average height Thai women. The objective of this study is to evaluate the anthropometric parameters of the proximal radius in such a population and its correlation with commercially available prostheses. Methods: Dominant elbows of 124 Thai women whose height was <155 cm were studied. Using the standard anteroposterior and lateral radiographic images, the head diameter and thickness, the distance between the articular surface and radial tuberosity, the narrowest intra-medullary canal diameter and the narrowest outer diameter of the radial neck were measured. Correlations between body height and each radiographic parameter were assessed using the Pearson correlation coefficient (PCC). The specifications of the commercial metallic radial head implants were reviewed and used to evaluate the relevant radiographic parameters. Results: Mean of the minimum and maximum head diameter was 18.54 ± 1.11 mm and 19.13 ± 1.17 mm, respectively; the thickness was 7.43 ± 0.69 mm, the distance between the articular surface and tuberosity was 19.05 ± 1.45 mm, the intra-medullary canal diameter was 7.63 ± 1.2 mm and the outer diameter of the radial neck was 11.13 ± 1.26 mm. There is a poor correlation between the participant's height and each parameter (PCC ≤ 0.50). In 24.2% of the participants, the smallest size of prosthetic designs with a head diameter of 20 mm is larger than +2 mm in reference to minor diameter. The minimum prosthetic head thickness is greater than the average value of the participants in 12 out of 15 designs. One participant has an outer neck diameter smaller than the smallest stem diameter of three designs. Conclusions: Surgeons must be aware that commercially available radial head replacement implants may be too large for below-average height Thai women. Level of Evidence: Level IV (Prognostic).

Radial head replacement using personalized 3D printed porous tantalum prosthesis

Fractures of the radial head account for 33% of elbow fractures. More and more studies have found that the radial head plays an important role in the normal function of the elbow joint, and many complications will occur after resection of the radial head. Accurate treatment of radial head fractures is crucially important. At this stage, commercialized radial head prosthesis of fixed size is commonly used in radial head replacement, but the mismatch of prosthesis and material problems have resulted in many complications. The three-dimensional (3D) printed porous tantalum has good biocompatibility, is conducive to bone ingrowth, has ideal elastic modulus, and can be prepared into a highly porous material that can be designed to match the radial head according to each patient's personalized anatomical structure. The purpose of this study was to investigate the elbow joint function, complications and prosthesis conditions after radial head replacement using 3D printed porous tantalum. Seven patients with comminuted fracture of radial head in our Center received radial head replacement using 3D printed porous tantalum. Patients were followed on the elbow joint function, range of motion (ROM), elbow radiographs, postoperative complications, and bone condition of tantalum metal. quality situation. Follow-up data showed that the patients had less postoperative pain, improved elbow function and ROM, and bone ingrowth in the tantalum prosthesis. The 3D printing porous tantalum can be applied to hip replacement, knee replacement, and other patients with irregular bone defects such as bone tumor, bone deformity, etc., which has the potential to realize personalized and precise treatment.

Outcomes of Posterior Monteggia Variant Fractures Repaired Through a Trans-Olecranon Approach

To evaluate the clinical and radiographic outcomes and complications following surgical treatment of adult posterior Monteggia fracture variants in which coexisting radial head and coronoid fractures were addressed through a single extensile posterior trans-olecranon approach. We performed a retrospective review from January 1, 2010, to January 1, 2021, of all adult patients who underwent fixation of posterior Monteggia variant fractures with coexisting radial head and/or coronoid fractures through a trans-olecranon approach by a single surgeon. Patient records were reviewed for postoperative complications and radiographic outcomes. All patients were contacted to participate in a repeat clinical examination and functional assessment. Thirteen patients met the inclusion criteria, of which 7 agreed to participate. Final follow-up was conducted at an average of 49 months postoperatively. Six patients had a coexisting radial head fracture, 1 had a radial neck fracture, and all 7 patients had a coronoid fracture. All 7 coronoid fractures were repaired, 2 patients had internal fixation of the radial head, and 5 had radial head replacement. Four patients underwent reoperation. There were no cases of infection or heterotopic ossification, and all patients achieved radiographic bony union. The average final range of motion was 13°-133° flexion-extension (range: 0°-30° extension to 125°-145° flexion), 76° pronation (range: 70°-90°) and 72° supination (range: 60°-90°). The average Mayo Elbow Performance Score was 86 (range: 70-100), average Visual Analog Scale score was 1.4 (range: 0-3), and average Disabilities of the Arm, Shoulder, and Hand score was 9.8 (range: 0.83-35.83). Use of a single extensile trans-olecranon exposure offers reliable visualization and access to all bony structures requiring repair while minimizing soft tissue disruption. Patients treated with this trans-olecranon surgical approach demonstrate satisfactory clinical and radiographic outcomes with low rates of heterotopic ossification, nonunion, and infection. Therapeutic IV.

Prevention of radial head instability by augmentation of annular ligament with local triceps tendon sheath autograft in radial head Fixation or Replacement: A case series

Prevention of radial head instability by augmentation of annular ligament with local triceps tendon sheath autograft in radial head Fixation or Replacement: A case series

Does stress shielding after radial head arthroplasty affect functional outcomes?

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). 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 24months. 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. 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). 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. Retrospective Cohort Comparison; Treatment Study.

Radial neck osteolysis after radial head replacement: Functional impact and risk factors

IntroductionOnset 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. HypothesisRNO prevalence is high, but functional impact is limited. Material and methodA 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. ResultsAt 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. ConclusionRNO 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 evidenceIV, cohort study.

Replacement of radial head

Replacement of radial head

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

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. 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. 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. 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.