Using 3D Printing Technology to Design Split-Piece Sleeve Prosthesis in the Revision Surgery of Tumor-Type Total Elbow Prosthetic Fractures: A Case Report.

BACKGROUND: Revision of tumor-type prosthetic fractures is very challenging in clinical work. Traditional repair methods may not be able to meet the needs of complex cases or cause greater bone damage. Therefore, more effective and reliable solutions need to be found. CASE PRESENTATION: This study presents a novel revision technique for managing fractures of tumor-type total elbow prostheses. A 57-year-old female patient was diagnosed with a left distal humeral bone tumor accompanied by pathological fracture and underwent customized tumor-type total elbow prosthesis arthroplasty. After 5 years, she experienced pain and encountered difficulty in flexing the left elbow while lifting heavy objects. The X-ray examination revealed a fracture of the distal humeral prosthesis. As a response, the elbow joint was initially explored, and the damaged component of the prosthesis was extracted. Subsequently, we utilized 3D printing technology to design a split-piece sleeve prosthesis and effectively restored the fractured left distal humerus implant. During the 2-year follow-up, The X-ray demonstrated satisfactory positioning of the prosthesis, which remained securely affixed without any indications of loosening. The Mayo Elbow Performance Score (MEPS) reached 80 points, the Musculoskeletal Tumor Society (MSTS) attained a score of 28 points, and the range of motion of the elbow was measured between 25° and 110°, revealing favorable functional outcomes. CONCLUSION: The utilization of a 3D printed split-piece sleeve prosthesis presents a viable clinical treatment strategy for addressing fractures in tumor-type elbow prostheses.

Long-terms outcomes of radial head arthroplasty using a bipolar prosthesis.

BACKGROUND: In acute treatment of radial head fractures, a radial head prosthesis can be considered if open reduction and internal fixation are not technically feasible. METHODS: We reviewed the data of 27 consecutive bipolar Judet radial head prostheses implanted in patients with unreconstructable radial head fractures and no other concomitant fractures (coronoid or olecranon factures). The lesions of the lateral collateral ligament were rated according to the McKee classification. Twenty-three patients with more than ten-year follow-up participated in this retrospective study All patients underwent assessments for pain, range of motion and stability using the Mayo Elbow Performance Score, the QuickDash questionnaire and a Visual Analogue Scale for pain. Radiography assessment was performed to determine the correct setting of the implant, presence of periprosthetic loosening, prosthetic disassembly, heterotopic ossification, capitellum and ulnohumeral degenerative changes. RESULTS: Mean follow-up was 149 months (± 12.2). Mean range of motion in flexion-extension was 111° (± 10.55), mean extension was 18° (± 14.32) and mean flexion was 130° (± 11.4). Mean arc of motion in supination-pronation was 150° (± 12.26). The mean Mayo Elbow Performance Score was 88, the mean QuickDash score was 7.3; 86% of the patients were satisfied. Seven patients (26%) required secondary surgery. The most frequent complication was heterotopic ossification, which had negative consequences on the functional result. CONCLUSIONS: Bipolar radial head prostheses are an option for acute treatment of isolated unreconstructable radial head fractures. During follow-up, three patients required implant revision and removal; the capitellum surface presented severe degenerative changes and the prosthesis was not replaced. Another complication was the risk of implant dislocation, in relation to implant design, incorrect positioning of the radial head stem or else to inadequate reconstruction of the lateral collateral ligament. Further work is needed to establish the long-term follow-up results of Judet implants in complex elbow fractures.

Complications of antibiotic cement spacers used for elbow infections.

BACKGROUND: Antibiotic cement spacers have been widely used in the treatment of joint infections. There are no commercially available antibiotic spacers for the elbow. Instead, they are typically fashioned by the surgeon at the time of surgery using cement alone or a combination of cement with sutures, Steinmann pins, external fixator components, or elbow arthroplasty components. There is no consensus regarding the ideal elbow antibiotic spacer and no previous studies have examined the complications associated with these handmade implants in relation to their unique structural design. METHODS: We retrospectively reviewed 55 patients who had 78 static antibiotic cement spacers implanted between January 1998 and February 2021 as part of a 2-stage treatment plan for infection of an elbow arthroplasty, other elbow surgery, or primary elbow infection. Several antibiotic spacer structures were used during the study period. For analysis purposes, the spacers were classified into linked and unlinked spacers based on whether there was a linking mechanism between the humerus and the ulna. Complications related to these spacers that occurred either during the implantation, between implantation and removal, or during removal were recorded and analyzed from chart review and follow-up x rays. Reoperations due to spacer-related complications were also recorded. RESULTS: Among the 55 patients (78 spacers), there were 23 complications, including 17 minor and 6 major complications. The most common complication of unlinked spacers (intramedullary [IM] dowels, beads and cap spacer) was spacer displacement. Other complications included IM dowel fracture and difficulty locating beads during spacer removal. The major complications of linked cement spacers included two periprosthetic humerus fractures after internal external fixator cement spacers and re-operation due to breakage and displacement of one bushing cement spacer. The major complications of unlinked cement spacers included two reoperations due to IM dowel displacement and one reoperation due to displacement of beads. Among patients who had removal of all components and those with native joints, there was no statistically significant difference between internal external fixator cement spacers and unlinked cement spacers in minor complication rates (30% vs. 16%, P = .16), major complication rates (7% vs. 8%, P = .85) and reoperation rates (0% vs. 8%, P = .12). CONCLUSIONS: Static handmade antibiotic elbow spacers have unique complications related to their structural designs. The most common complication of linked and nonlinked cement spacers were failure of the linking mechanism and displacement, respectively. Surgeons should keep in mind the possible complications of different structures of cement spacers when choosing 1 antibiotic spacer structure over another.

Radial head replacement with the 3D-printed patient-specific titanium prosthesis: Preliminary results of a multi-centric prospective study.

PURPOSE: To report preliminary clinical results and safety of 3D-printed patient-specific titanium radial head (RH) prosthesis in treatment of the irreparable RH fractures. MATERIAL AND METHODS: This multi-centric prospective study included 10 patients (6 men and four women, mean age 41 years (range, 25-64 years)). Three cases were classified as Mason type III and 7 cases as type IV. Patients were assessed preoperatively, intraoperatively, and at 1, 6, 12, 24, 36, and 48 weeks postoperatively. Range of motion (ROM), visual analog scale (VAS) score, Disabilities of the Arm, Shoulder and Hand (DASH) score, Mayo Elbow Performance Score (MEPS), radiology imaging, and laboratory blood and urine testing were evaluated. RESULTS: The prostheses were implanted utilizing cemented stems in 5 patients and cementless stems in 5 patients. Intraoperatively, well congruency of a prosthesis with capitellum and radial notch of ulna was observed in all cases. All patients had improvement of ROM, VAS score, DASH score, and MEPS during the postoperative follow-ups. At the final follow-up, mean elbow extension was 6.5° (range, 0°-30°), flexion 145° (range, 125°-150°), supination 79° (range, 70°-80°), and pronation 73.5° (range, 45°-80°). Mean VAS score was 0.3 (range, 0-3), DASH score was 12.35 (range, 1.7-23.3), and MEPS was 99.5 (range, 95-100). Postoperative radiographs demonstrated heterotopic ossification in 2 cases, periprosthetic radiolucency in 2 cases, and proximal radial neck resorption in 2 cases. No one had the evidence of capitellar erosion, implant failure, malpositioning, overstuffing, or symptomatic stem loosening. There was no significant alteration of laboratory results or adverse events related to the 3D-printed prosthesis implantation. CONCLUSION: The preliminary results demonstrated that implantation of the 3D-printed patient-specific titanium RH prosthesis is safe and may be a potential treatment option for irreparable RH fracture.

High failure rate of 2-stage revision for the infected total elbow arthroplasty: a single institution's experience.

BACKGROUND: Despite 2-stage revision being a common treatment for elbow prosthetic joint infection (PJI), failure rates are high. The purpose of this study was to report on a single institution's experience with 2-stage revisions for elbow PJI and determine risk factors for failed eradication of infection. The secondary purpose was to determine risk factors for needing allograft bone at the second stage of revision in the setting of compromised bone stock. METHODS: We retrospectively analyzed all 2-stage revision total elbow arthroplasties (TEAs) performed for infection at a single institution between 2006 and 2020. Data collected included demographics and treatment course prior to, during, and after 2-stage revision. Radiographs obtained after explantation and operative reports were reviewed to evaluate for partial component retention and incomplete cement removal. The primary outcome was failed eradication of infection, defined as the need for repeat surgery to treat infection after the second-stage revision. The secondary outcome was the use of allograft for compromised bone stock during the second-stage revision. Risk factors for both outcomes were determined. RESULTS: Nineteen patients were included. Seven patients (37%) had either the humeral or ulnar component retained during the first stage, and 10 (53%) had incomplete removal of cement in either the humerus or ulna. Nine patients (47%) had allograft strut used during reimplantation and reconstruction. Nine patients (47%) failed to eradicate the infection after 2-stage revision. Demographic data were similar between the repeat-infection and nonrepeat-infection groups. Six patients (60%) with retained cement failed compared with 3 patients (33%) with full cement removal (P = .370). Two patients (29%) with a retained component failed compared to 7 patients (58%) with full component removal (P = .350). Allograft was used less frequently when a well-fixed component or cement was retained, with no patients with a retained component needing allograft compared to 9 with complete component removal (P = .003). Three patients (30%) with retained cement needed allograft, compared with 6 patients (67%) who had complete cement removal (P = .179). CONCLUSION: Nearly half of the patients failed to eradicate infection after 2-stage revision. The data did not demonstrate a clear association between retained cement or implants and risk of recurrent infection. Allograft was used less frequently when a component and cement were retained, possibly serving as a proxy for decreased bone loss during the first stage of revision. Therefore, the unclear benefit of removing well-fixed components and cement need to be carefully considered as it likely leads to compromised bone stock that complicates the second stage of revision.

Total Arthroplasty in Complex Elbow Injury / Artroplastia total na lesão complexa do cotovelo

Abstract The authors present an atypical case of a left elbow complex fracture with extensive loss of bone and muscle tissue. The patient was submitted to several surgical procedures, which resulted in a total arthroplasty of the left elbow with triceps reconstruction using a semitendinosus muscle tendon graft.

Resumo Os autores apresentam um caso atípico de fratura complexa do cotovelo esquerdo com perda extensa de tecido ósseo e muscular. O paciente foi submetido a diversos procedimentos cirúrgicos, que resultaram em uma artroplastia total do cotovelo esquerdo associada à reconstrução do tríceps com enxerto do tendão do músculo semitendíneo.

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 SystemTM 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.

Study of a constrained finite element elbow prosthesis: the influence of the implant placement.

BACKGROUND: The functional results of total elbow arthroplasty (TEA) are controversial and the medium- to long-term revision rates are relatively high. The aim of the present study was to analyze the stresses of TEA in its classic configuration, identify the areas of greatest stress in the prosthesis-bone-cement interface, and evaluate the most wearing working conditions. MATERIALS AND METHODS: By means of a reverse engineering process and using a 3D laser scanner, CAD (computer-aided drafting) models of a constrained elbow prosthesis were acquired. These CAD models were developed and their elastic properties, resistance, and stresses were studied through finite element analysis (finite element method-FEM). The obtained 3D elbow-prosthesis model was then evaluated in cyclic flexion-extension movements (> 10 million cycles). We highlighted the configuration of the angle at which the highest stresses and the areas most at risk of implant mobilization develop. Finally, we performed a quantitative study of the stress state after varying the positioning of the stem of the ulnar component in the sagittal plane by ± 3°. RESULTS: The greatest von Mises stress state in the bone component for the 90° working configuration was 3.1635 MPa, which occurred in the most proximal portion of the humeral blade and in the proximal middle third of the shaft. At the ulnar level, peaks of 4.1763 MPa were recorded at the proximal coronoid/metaepiphysis level. The minimum elastic resistance and therefore the greatest stress states were recorded in the bone region at the apex of the ulnar stem (0.001967 MPa). The results of the analysis for the working configurations at 0° and 145° showed significant reductions in the stress states for both prosthetic components; similarly, varying the positioning of the ulnar component at 90° (- 3° in the sagittal plane, 0° in the frontal plane) resulted in better working conditions with a greater resulting developed force and a lower stress peak in the ulnar cement. CONCLUSION: The areas of greatest stress occur in specific regions of the ulnar and humeral components at the bone-cement-prosthesis interface. The heaviest configuration in terms of stresses was when the elbow was flexed at 90°. Variations in the positioning in the sagittal plane can mechanically affect the movement, possibly resulting in longer survival of the implant.

Testing of Novel Total Elbow Prostheses Using Active Motion Experimental Setup.

PURPOSE: The goal of this study was to test a novel uncemented and unconstrained total elbow arthroplasty (Kaufmann total elbow) design that is stabilized through a ligament reconstruction. METHODS: We quantified the implant stability after 25,000 cycles, which represents the time between implantation and when ligament and bone healing has occurred. We used an active motion experimental setup that applies tendon loads via pneumatic cylinders and reproduces the forearm-originating dynamic stabilizers of the elbow. The novel total elbow arthroplasty was actuated for 5,000 full flexion-extension cycles at 5 different shoulder positions. Four Sawbones and 4 cadaver elbows were employed. Angular laxity and implant stability were recorded prior to testing and after each 5,000-loading cycle. RESULTS: Four Sawbones and 4 cadaver elbows were implanted with the uncemented total elbow arthroplasty and did not demonstrate fixation failure or substantial laxity after 25,000 cycles of loading imparted at different shoulder positions. CONCLUSIONS: Our findings demonstrate that the Kaufmann total elbow replacement implanted into cadaver and Sawbones specimens did not exhibit fixation failure or excessive laxity after 25,000 cycles. CLINICAL RELEVANCE: An uncemented, nonmechanically linked total elbow arthroplasty that gains component fixation using intramedullary screws and employs a ligament reconstruction to stabilize the elbow has the potential to be a valuable management option, particularly in younger patients.

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.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: An increase in radial prosthesis height significantly increases capitellar contact pressures and reduces coronoid contact pressures. CLINICAL RELEVANCE: 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.

Modified Masquelet Technique Assisting 3D Printed Elbow Prosthesis for Open Elbow Fracture with Severe Bone Defect: A Case Report and Technique Note.

BACKGROUND: Internal fixation for severe open articular bone defects is sometimes ineffective or dangerous. In the emergency stage, radical debridement and infection prevention are demanded to provide a good tissue base and the space-occupying effect to provide enough necessary space to avoid soft-tissue contraction for the reconstruction. In addition, the 3D printing technology makes individual limb reconstruction a reality. CASE PRESENTATION: Here, we present a 31-year-old patient with an open fracture and severe bone defect of his left elbow caused by traffic accident, classified as Gustilo-Anderson IIIB. We adopted aggressive debridement and insertion of polymethyl methacrylate (PMMA) to prevent the infection and temporarily construct the bone defect in the emergency stage. Secondly, the total elbow arthroplasty was performed using a unique three-dimensional (3D) printed prosthesis to reconstruct the elbow joint. During the follow-up, the elbow movement function was satisfactory. CONCLUSIONS: The modified Masquelet technique assisting 3D printing of personalized elbow joint makes the satisfactory functional reconstruction for open high-energy injuries come true. It could be promoted for the similar surgery of other open joints fractures with severe bone defects.

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).

Patient- and Procedure-Specific Variables Associated With Removal or Revision of Radial Head Arthroplasty.

Introduction The purpose of this retrospective review was to identify risk factors associated with removal or revision following radial head arthroplasty. Methods Patients undergoing primary radial head arthroplasty between 2009 and 2015 with a minimum follow-up of 1 year were identified. Descriptive and bivariate statistics were used to analyze the characteristics of patients requiring implant removal or revision and multivariable analysis was performed to calculate hazard ratios. Results There were 312 patients included in the final cohort with a median follow-up of 3.8 years. Thirty-five patients (11.2%) underwent prosthesis removal or revision. There was an increased percentage of implants removed or revised in patients under age 40, with surgery performed for chronic indications compared to acute trauma, and with the use of press-fit stems compared to polished. Discussion It appears younger patient age, chronic surgical indications, and certain aspects of prosthesis design may influence rates of removal or revision.

[Radial head prosthesis for acute fractures]. / Radiuskopfprothese bei akuten Frakturen ­ wann und welche?

Non-reconstructible radial head fractures with concomitant injuries and resultant instability of the elbow are often treated by implantation of a radial head prosthesis. Various prosthetic designs and implantation techniques are available. Several pitfalls have to be respected during implantation. This article provides tips and tricks for successful implantation and aftercare and gives an overview of long-term outcomes and revision rates.

[Elbow prosthesis after acute fractures : Indications and technique]. / Ellenbogenprothese nach akuten Frakturen : Indikation und Technik.

Good to very good clinical results can be achieved in older patients with the implantation of a total elbow prosthesis in cases of distal humeral fractures by taking the morphological features of the fractures, the bone quality as well as the individual patient requirements and variables into account. The most commonly used design is the cemented semiconstrained linked total elbow endoprosthesis. The unlinked prosthesis design and hemiarthroplasty require intact or adequately reconstructable musculoligamentous structures or condyles and a preserved or replaced radial head. The recommended weight limit after total elbow prosthesis as well as potential intraoperative and postoperative complications must be considered and discussed with the patients. A secondary total elbow arthroplasty is also possible after primary conservative treatment approaches, e.g., in the case of contraindicated surgery in the fracture situation, persistent pain and functional restrictions. This article provides an overview of the technique and the appropriate indications.

Coonrad-Morrey total elbow arthroplasty implications in young patients with post-traumatic sequelae.

BACKGROUND: We aimed to evaluate the clinical and radiological results of total elbow arthroplasty (TEA) performed for trauma sequelae in patients <45 years of age. METHODS: This retrospective study included 63 patients aged <45 years who underwent TEA between 2005 and 2017 for previous elbow injuries. The average follow-up period was 5.23 years (range, 2-13 years). The clinical analysis included limb function according to the Mayo Elbow Performance Score, Oxford Elbow Score, and range of motion. The degree of radiolucency was determined using plain radiographic images. RESULTS: The average amplitude of elbow flexion/extension increased from 49.1 ± 36.7 to 98.7 ± 28.2 (P < .01), and the average amplitude of elbow pronation/supination increased from 87.2 ± 52.3 to 118.7 ± 26.3 (P = .02). Functional results improved from 21.4 ± 13.1 to 67.3 ± 14.5 (P < .01) on the Mayo scale, and those measured according to the Oxford scale improved from 15.4% ± 7.0% to 28.0% ± 10.6% (P < .01). Complications were observed in 16 (32.7%) patients. Among them, 10 patients (20.4%) required revision elbow arthroplasty with replacement of implant components. The overall 5-year implant survival rate was 79.4% (95% confidence interval: 63.4-91.2), and the 10-year survival rate was 77.5% (95% confidence interval: 59.3-88.2). CONCLUSION: TEA allows restoration of the full range of motion in the elbow joint and significantly improves limb function in most cases. However, the low survival rate of implants and high incidence of complications do not permit TEA to become a routine intervention for treating post-traumatic consequences in young patients.

The load transfer effect of monopolar and bipolar radial head prosthesis designs on capitellar cartilage: A comparative biomechanical cadaver study.

OBJECTIVE: The aim of this study was to determine whether bipolar radial head arthroplasty may transfer less load to the capitellum than monopolar radial head arthroplasty and native radial heads. METHODS: Six human elbow joints were obtained from six fresh frozen cadavers (3 males, 3 females; mean age = 78 years, age range = 66-80). None of the elbow joints had a previous osseous injury, a chondral defect, osteoarthritis, or instability. In group 1, load transfer of the native radial head was measured in each specimen under 100 N of compression force using a custom-made load cell at 0°, 30°, 60°, 90°, and 120° flexion of the elbow in supination, neutral rotation, and pronation, respectively. After excision of the radial heads, the same testing protocol was first applied for monopolar radial head arthroplasty (Group 2) and then for bipolar radial head arthroplasty (Group 3). RESULTS: The mean load transfer on the capitellum was significantly higher in each forearm rotation and all angles of the elbow flexion in the arthroplasty groups than the native radial head group. Mean load transfer values of bipolar prostheses were between the values of native radial heads and monopolar prostheses in all positions. Bipolar prostheses showed similar load transfer characteristics compared to those of the native radial head in supination at 60° flexion; in neutral rotation at 0°, 30°, 60°, and 120° flexion; and in pronation at 90° and 120° flexion. CONCLUSION: The results of this study have revealed that bipolar radial head arthroplasty transfers similar loading as the native radial head on the capitellum in certain forearm positions and at elbow flexion angles. No significant differences could be found between load transfer values of bipolar head design and monopolar head design except in the pronation at full extension.

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.

Silicone radial head prostheses: the clinical course and treatment of failure-a case series.

INTRODUCTION: Silicone radial head prostheses (SRHP) have a reputation of acceptable initial function but failure in the medium to long term as a result of the disintegration of the silicone material. Damaged SRHP can result in a silicone-induced synovitis and destruction of the joint. Early removal of damaged SRHP may prevent joint destruction. Literature is scarce; there are no studies describing early symptoms associated with clinical failure of SRHP and very few studies on appropriate treatment of destructed SRHP. The aim of this study was to describe the clinical course of failing SRHP and to provide practical guidance for treatment. METHODS: Fifteen consecutive cases of failed SRHP, operated between 2005 and 2020, were retrospectively reviewed, using patient logs, radiographic results, and a questionnaire. Relevant data concerning pre- and postoperative complaints, function, and surgical details were gathered. Using the questionnaire, retrospective and current patient reported outcomes including Single Assessment Numeric Evaluation (SANE) scores, pain, instability, and range of motion were analyzed. RESULTS: The average time between implantation of the SRHP until outpatient presentation was 16 years. The average recalled SANE score before start of complaints was 8.6 out of 10 points. In 4 patients, the onset of complaints was preceded by a trauma. Five patients had symptoms for more than a year, and 9 patients for several months. Progressive pain in the elbow and/or wrist and mechanical symptoms were early and prominent symptoms of failure. Clinical signs of synovitis were frequently present. The majority of patients had a slow but progressive onset of complaints over several months before presentation. Twelve of 15 cases of failed SRHP were surgically treated. Fragmentation of the implant, osteoarthritis, and synovitis were found in all surgically treated cases. Both surgical removal and synovectomy alone, and revision to a new radial head prosthesis resulted in good medium-term outcomes with a mean SANE score of 7.3 points at 8.4 years of follow-up. Postoperative extension lags and mild instability were frequently mentioned as a reason for reimplantation of a metallic radial head implant and removal of the radial head alone, respectively. CONCLUSION: Both patients and physicians should be aware of early symptoms of a failing SRHP. Adequate recognition, radiographic evaluation, and early intervention may favor outcomes of failing SRHP. Surgical removal is easy to perform. In selected cases, revision of the radial head prosthesis may be considered. Both of these treatment strategies resulted in satisfying outcomes.