Intraoperative visualization of the posterolateral ulnohumeral joint space is reliable to indicate overlengthening in radial head arthroplasty.

INTRODUCTION: Avoiding overlengthening in radial head arthroplasty (RHA) is essential for the prognosis of the elbow joint. An overlengthening from 2 mm is visible due to widening of the anterolateral ulnohumeral joint space but intraoperatively, this particular joint space is difficult to visualize. The commonly used Kocher approach allows visualization of the posterolateral joint space without additional instruments or further surgical release of the already unstable elbow. The aim of our study was to investigate whether the visualization of the posterolateral joint space is also a reliable method to indicate overlengthening in RHA. MATERIAL AND METHODS: RHA was performed in five human cadaveric specimens with the forearm, wrist, and hand intact. The lateral ligament complex was detached and an anatomic transosseous refixation was performed. Six stages of implantation heights were documented: native joint (1), RHA at the anatomic height (2), + 2 mm (3), + 4 mm (4), + 6 mm (5) and - 2 mm (6). Macroscopic measurement and digital image analysis of the posterolateral and anterolateral ulnohumeral joint spaces were performed. RESULTS: All stages of overlengthening showed a significant increase in posterolateral and anterolateral joint space widening (p < 0.05). The posterior and anterior joint space showed excellent intraclass correlation. CONCLUSION: Visualization of the posterolateral aspect of the ulnohumeral joint space is a reliable indicator for overlengthening in RHA without further compromising an already unstable elbow. Correlation to the findings of the anterolateral ulnohumeral joint space in different implants leads to the assumption that visualization of either the anterior or posterior ulnohumeral joint space is universally applicable to determine overlengthening in RHA, regardless of the type of the radial head implant.

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

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Risk of radial head arthroplasty revision is correlated with radial head diameter: a multicenter analysis of 405 cases.

BACKGROUND: Radial head arthroplasty (RHA) is commonly used for the treatment of comminuted radial head fractures. Indications as well as implant types continue to evolve. RHA has had good outcomes with midterm longevity. The literature is limited to small case series with varying implant types, and larger studies are needed to determine the optimal implant type and radial head diameter. METHODS: A retrospective analysis of RHA cases performed by 75 surgeons at 14 medical centers in an integrated health care system between 2006 and 2017 was completed. Patient demographics, comorbidities, implant type and head diameter, and indications for revision were recorded. Patients' in-person clinical visit data were recorded. Patients were also contacted via telephone at a minimum of 2 years to obtain abbreviated Disabilities of the Arm, Shoulder, and Hand questionnaire and Oxford scores. Implant survivorship was also captured within our integrated system. RESULTS: 405 cases met our inclusion criteria. Mean age was 51.5 ± 15.5 years (range 16-88 years) and more common in females (62%). Chart review and telephone follow-up was performed at a mean of 68.9 ± 31.5 months (range 24-146 months). Our study found that revision rate was positively correlated with increasing radial head diameter. A 26-mm head had 7.7 odds of revision compared to a size 18-mm head (95% confidence interval 1.2-150.1). More than 95% of revision cases were performed within the first 36 months of the index procedure. Obese patients had a significantly lower mean postoperative Oxford score (35.5) compared to controls (38.3) (P = .02). There was a significantly higher overall reoperation rate for terrible triad (18.4%) vs. isolated injuries (10.4%) (P = .04). There was no difference between Acumed Anatomic and Evolve radial head implants in overall reoperation, implant revision, postoperative range of motion, or patient-reported outcomes. CONCLUSIONS: Risk of revision is directly correlated with implanted radial head diameter. There were no differences in outcomes and complications between the 2 main implants used. Individuals who did not undergo a revision by 3 years' time tend to retain the implant. Terrible triad injuries had a higher all-cause reoperation rate than isolated radial head fractures, but no difference in the rate of RHA revision. These data reinforce the practice of downsizing radial head implant diameter.

Correlation between radiographic findings and clinical failure in monopolar radial head replacement.

INTRODUCTION: The purpose of this study is to analyze the mid-term outcomes of a modular monopolar type of radial head arthroplasty in the treatment of complex fractures associated with acute elbow joint instability. We postulated that radiographic changes are related to the development of clinical complications. MATERIALS AND METHODS: We evaluated at last follow-up 26 radial head arthroplasties in 26 consecutive patients who were followed for at least one and a half year. All patients had suffered radial head fractures (Mason III) in the context of unstable elbow injuries. Definitive treatment of the radial fracture was performed with modular and monopolar prosthesis which was inserted as a press fit. All patients were evaluated preoperatively and postoperatively. The evaluation included a clinical examination and a protocolized imaging study (standard X-Rays and CT) of the elbow. We analyzed the incidence of: heterotopic ossifications, secondary radiocapitellar joint osteoarthritis, hardware loosening, hardware disengagement, and joint infection. Diagnosis of clinical failure of the implant was defined as the time to the second surgery due to major complications related to the prosthesis, such as persistent lateral side pain or elbow stiffness and any kind of implant instability or dislocation. RESULTS: The implant-specific reoperation rate was 15% (four reoperations). The need for the second surgery was statistically associated with heterotopic ossifications, radiocapitellar osteoarthritis and cortical resorption around radial neck (p = 0.054, p = 0.033, and p = 0.019, respectively), being periprosthetic osteolysis the most likely factor related to failure, and radial pain the main symptom leading to surgical revision. CONCLUSIONS: Our study shows a positive association between radiographic findings and patient symptoms for postoperative complications after radial head arthroplasty. Failed radial head replacements may lead to reoperation mainly due to pain, and this can be distinguished from other causes of pain in elbow region based on its radial location. Radiological loosening was prevalent in this group of failed replacement.

[Combined convergent elbow dislocation with posterior luxation of the humeroulnar joint and radial head comminuted fracture in adults]. / Kombinierte konvergente Ellenbogenluxation mit posteriorer Luxation des Humeroulnargelenks und Radiuskopftrümmerfraktur beim Erwachsenen.

Transposition of the proximal radioulnar joint, so-called convergent elbow dislocation, is an extremely rare injury whereby the proximal radius crosses over the proximal ulnar and converges medially. This injury can occur in isolation or even less frequently in association with a posterior humeroulnar dislocation. Open reduction is almost always necessary. The diagnosis is frequently delayed as the injury is easily overlooked. In the literature, 13 cases in children and 2 in adults have so far been described. This is the first report of a combined elbow dislocation (posterior and convergent) with an initially diagnosed and definitively treated comminuted radial head fracture in adults.

Maximizing outcomes in the treatment of radial head fractures.

The radial head plays a critical role in the stability of the elbow joint and its range of motion. Injuries may occur across a spectrum of severity, ranging from low energy non-displaced fractures to high energy comminuted fractures. Multiple classification systems exist to help characterize radial head fractures and their associated injuries, as well as to guide treatment strategies. Depending on the type of fracture, non-operative management may be possible if early range of motion is initiated. Other options include open reduction and internal fixation or excision followed by arthroplasty. A lateral approach is typically used for adequate surgical exposure. Controversy still remains regarding operative management of more severe fractures, but studies have shown good outcomes after radial head replacement for these fractures. We will review the current treatments available for radial head fractures, highlighting gaps in knowledge, as well as providing recommendations for the care of these injuries.Level of evidence: Level V.

Rare implant-specific complications of the MoPyC radial head prosthesis.

BACKGROUND: According to currently available data, the clinical short-term results of the MoPyC radial head prosthesis (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) seem favorable. However, we have encountered several implant-specific complications in recent years. Hence, this case series reports rare complications after radial head arthroplasty with the MoPyC prosthesis to make surgeons aware of their existence and to provide information about the underlying cause and possible salvage strategies. METHODS: A retrospective chart review from 2011 to 2016 was conducted to identify all adult patients with a minimum 2-year follow-up who underwent or were referred after radial head arthroplasty with the MoPyC radial head prosthesis and experienced implant-related complications. RESULTS: Five patients with 7 implant-related complications were found. One patient experienced breakage of the pyrocarbon head. In another patient, breakage of the stem and-after revision surgery-partial breakage were observed. Disassembly of the prosthesis was seen in 1 case. Extensive periprosthetic stress shielding was seen in 3 patients resulting in symptomatic loosening (1), periprosthetic radial neck fracture (1), and stem migration (1). CONCLUSIONS: Whereas clinical short-term results of the MoPyC radial head prosthesis are satisfactory, rare implant-related complications can occur. Surgeons should be aware of these complications as they may lead to a poor outcome.

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

BACKGROUND: When necessary, radial head integrity after a fracture can be re-created by the use of a radial head arthroplasty if the radial head is judged irreparable. The purpose of this study was to compare the clinical and radiographic outcomes of metal modular radial head replacements with a smooth vs. a porous stem. METHODS: A retrospective cohort study of radial head replacements performed in the first 4 weeks after a trauma in an adult patient at our institution between 2000 and 2014 was completed. Patients were divided into 2 groups: a porous stem group (ExploR; Biomet Orthopedics, Warsaw, IN, USA) and a smooth stem group (EVOLVE; Wright Medical Group, Memphis, TN, USA). Primary outcomes were the Disabilities of the Arm, Shoulder, and Hand and Mayo Elbow Performance Index scores. Secondary outcomes were the visual analog scale score for pain, range of motion, grip strength, and radiographic evaluations. RESULTS: Of the 80 eligible patients, 57 agreed to participate (porous stem group, 36; smooth stem group, 21). Demographic data were similar between the 2 groups. Average follow-up was 6.3 years. Average Disabilities of the Arm, Shoulder, and Hand and Mayo Elbow Performance Index scores were similar between the 2 groups. Porous implants were more prone to osteolysis (64.3% vs. 23.5%; P = .01) and were associated with a greater loss of elbow flexion (6° vs. 1°; P = .02). The porous stem group showed a tendency toward more overstuffing (24.0% vs. 5.9%; P = .21). CONCLUSION: Our results reveal that outcomes between smooth and porous stem metal modular radial head implants are equivalent. However, the smooth stem implant may represent the preferred option as it is associated with a lower rate of complications.

Surgical treatment of Monteggia variant fracture dislocations of the elbow in adults: surgical technique and clinical outcomes.

PURPOSE: Monteggia variant defined as Monteggia fracture dislocation with radial head or neck fracture, coronoid fracture, ulnohumeral joint dislocation or combination of these injuries. The aim of this study was to evaluate clinical outcomes of surgical treatment of Monteggia variant fracture dislocations with focus on the operative technique and management of associated radial head fractures. METHODS: Between January 2008 and January 2014, 22 patients (7 men, 15 women) with a mean age of 58.9 years (45-77 years) and unilateral Monteggia variant were included. The mean follow-up was 4.1 years (2.2-6.6 years). Patients underwent clinical and functional assessment using the Mayo Elbow Performance Index and the Oxford Elbow Score. RESULTS: Eighteen patients had radial head fractures; in five patients the fracture fragment involved less than one-third of the radial head and the fragment was excised, in four patients the radial head fracture was fixed with headless screws and in nine patients the radial head was replaced. At review the mean Mayo Elbow Performance Index was 76.6 (20-100) and the Oxford Elbow Score 35 (4-48). CONCLUSIONS: Our experience suggests that satisfactory outcomes can be obtained in the treatment of the complex Monteggia variant fracture dislocations by recognising the injury pattern and addressing all components of the injury in order to achieve elbow stability.

Intraoperative fluoroscopic assessment of proper prosthetic radial head height.

BACKGROUND: Selecting a properly sized radial head prosthesis is imperative during radial head replacement. Although there has been much emphasis on avoiding overlengthening of the radius, little has been studied about how to avoid shortening. The purpose of this study was to characterize how a radial head replacement appears on intraoperative fluoroscopy depending on the height of the prosthetic radial head. METHODS: Articular cartilage thickness of the radial head was measured in 9 cadaveric elbows. Radial head replacement was performed in each specimen with 4 different prosthetic head heights: 4 mm and 2 mm shortening, anatomic, and 2 mm overlengthening. Anteroposterior fluoroscopic images were obtained for each head height, and the prosthetic radial head height was measured at 3 forearm positions (supination, neutral, and pronation) using the subchondral bone of the lateral edge of the coronoid at the reference point. RESULTS: The mean cartilage thickness of the radial head was 1.3 ± 0.4 mm. The prosthetic radial head appeared 2.2 ± 0.4 mm more proximal than the subchondral bone of the coronoid lateral edge in anteroposterior radiographs when the articular surface of the prosthesis was completely even with the coronoid articular surface. Unlike the native radial head, a prosthetic radial head showed a significant change of height with different forearm rotation (P < .001). DISCUSSION: This study found that a perfectly anatomic radial head replacement appears overlengthened by approximately 2 mm in intraoperative radiographs. This finding can be useful in guiding the appropriate height of a prosthetic radial head.

The effect of prosthetic radial head geometry on the distribution and magnitude of radiocapitellar joint contact pressures.

PURPOSE: To determine if radiocapitellar contact pressures would be elevated with nonanatomical (circular) prostheses over those mimicking native anatomy and if such pressures would be related to the depth and contour of the articular dish and to the pattern of prosthetic articulation against the lateral trochlear ridge. METHODS: Three commercially available circular radial head designs were compared with an anatomical radial head and 2 modified anatomical prototype radial head designs in 10 cadaveric specimens. Each prosthesis and specimen combination was loaded in neutral rotation and maximal extension with a custom testing apparatus while measuring contact areas and pressures using thin-film pressure sensors. RESULTS: Anatomical radial head prototype 2 had similar radiocapitellar contact areas and mean pressures as the native radial head; all other designs showed significant decreases in contact area and increased mean pressures. Peak contact pressures were also measured and were significantly elevated with all prostheses tested. Anatomical designs are statistically more likely to mimic normal contact with the lateral trochlear ridge and its adjacent sulcus than circular prostheses. They are also significantly less likely to have contact pressures above the 5 MPa threshold that is thought to be harmful to cartilage. The depth of the articular dish had a significant effect on contact area and pressure. CONCLUSIONS: Commercially available radial head prostheses demonstrated reduced radiocapitellar contact areas and elevated contact pressures during compressive loading. These were significantly greater with symmetrical circular prostheses than with asymmetrical elliptical designs. The prosthesis that best mimicked native contact behavior was the anatomical radial head prototype 2 owing to its design for articulating with the capitellum, the lateral trochlear ridge, and the sulcus between. CLINICAL RELEVANCE: Because radial head prostheses have the potential to cause capitellar erosion or arthritic change, those with lower contact pressures may lead to fewer such complications.

The effect of fracture comminution on the reliability and accuracy of radial head sizing.

BACKGROUND: Radial head implant sizing can be based on the maximum head diameter (D-MAX), the minimum head diameter (D-MIN), or the articular dish diameter (D-DISH). The purpose of this study was to assess the reliability of the different radial head sizing techniques and to investigate the effect of radial head fracture comminution on measurement accuracy. METHODS: Ten observers measured 11 cadaveric radial heads with 3 radial head features (D-MAX, D-MIN, and D-DISH diameter). Radial heads were then fractured into 2, 3, and 4 parts, and the measurements were repeated. Variability was assessed by intraclass correlation. The measurements were compared with the intact state to assess the effect of radial head fracture comminution on sizing accuracy. RESULTS: D-MAX and D-MIN measurements were the most reliable among all observers (intraclass correlation coefficients, 0.980, 0.973). The D-DISH measurement was less reliable (intraclass correlation coefficient, 0.643). Radial head comminution did not significantly affect the reliability of any measurement (P > .2). Fracture comminution, however, significantly affected measurement accuracy with D-MAX and D-DISH. With fracture comminution, D-MAX underestimated radial head diameter (-0.4 ± 0.3 mm; P < .001), whereas D-DISH overestimated diameter (+0.5 ± 0.4 mm; P < .001). Comminution did not significantly affect D-MIN (-0.1 ± 0.3 mm; P = .13). DISCUSSION: The D-MAX and D-MIN measurements were more reliable than D-DISH for diameter sizing of intact and comminuted radial heads. Overall, increasing comminution did not significantly affect measurement reliability. However, the accuracy of the D-MIN technique was least affected by comminution, suggesting that D-MIN should be used in selecting the diameter of a radial head implant.

Chronic Essex-Lopresti injuries: an alternative treatment method.

BACKGROUND: Currently, no technique has met general acceptance for the restoration of forearm longitudinal stability in chronic Essex-Lopresti injuries. The purpose of this study is to present an alternative treatment method for chronic Essex-Lopresti lesions by radial head replacement and ulnar shortening osteotomy. METHODS: Seven patients with a mean age of 42.4 years were included in the study. Five patients had a staged approach, and 2 underwent both procedures simultaneously. The pain level was assessed with the use of a visual analog scale. Elbow, forearm, and wrist range of motion was evaluated. The Mayo Elbow Performance Score and Mayo Wrist Score were used to assess the postoperative outcomes. RESULTS: The mean follow-up time was 33 months. The mean pain level was reduced from 8.4 points preoperatively to 3.3 points postoperatively (P < .05). The elbow arc of motion was increased on average from 79° preoperatively to 121° postoperatively (P < .05). Forearm rotation improved from 76° preoperatively to 119° postoperatively (P < .05). The wrist arc of motion improved from 94° preoperatively to 114° postoperatively (P < .05). The mean postoperative Mayo Elbow Performance Score and Mayo Wrist Score were 82 points and 71 points, respectively. The mean ulnar variance was reduced from +8 mm to +3.5 mm postoperatively. CONCLUSION: This study shows that radial head replacement in combination with ulnar shortening osteotomy can be used as an alternative reconstructive procedure in the case of a complex chronic Essex-Lopresti injury. This combination of known procedures yields predictable and satisfactory outcomes and a low complication rate. LEVEL OF EVIDENCE: Level IV, case series, treatment study.

Selecting the diameter of a radial head implant: an assessment of local landmarks.

INTRODUCTION: Little information exists on radial head implant diameter sizing methods. When the native head is absent due to extensive comminution or previous excision, the lesser sigmoid notch may be a useful landmark for sizing. We evaluated the reliability of native radial head measurements, and the lesser sigmoid notch, as landmarks for radial head implant diameter sizing. METHODS: We examined 27 fresh frozen ulnae and their corresponding radial heads. The maximum, minimum, and dish diameters of the radial heads were measured. A radial head implant diameter was selected based on the congruency of the trial implants with the radius of curvature of the lesser sigmoid notch. Intraobserver and interobserver reliability for all measurements and implant selection were assessed using intraclass correlation coefficients (ICC). Correlations between the native radial head measurements and the selected radial head implant diameter or the lesser sigmoid notch radius of curvature were assessed using the Pearson correlation coefficient (PCC). RESULTS: Radial head diameter measurements demonstrated strong to excellent intraobserver (ICC ≥ 0.75) and interobserver reliability (ICC ≥ 0.82). The lesser sigmoid notch sizing method showed poor interobserver reliability (ICC = 0.34). Only a moderate correlation was found between the native radial head and the lesser sigmoid notch (PCC ≤ 0.80) or the selected radial head implant size (PCC ≤ 0.59). CONCLUSION: Radial head diameter measurements showed excellent reliability, suggesting that the excised radial head, when available, should be used to select the implant diameter. The reliability of using the lesser sigmoid notch for sizing the diameter of radial head implants was only moderate, suggesting this is an unreliable landmark for implant diameter sizing.

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

INTRODUCTION: Onset of radial neck osteolysis (RNO) has been reported after radial head replacement (RHR), but data are sparse regarding impact and risk factors. We therefore conducted a retrospective study, 1) to quantify RNO after RHR, 2) to assess clinical and radiological impact, and 3) to identify risk factors. HYPOTHESIS: RNO prevalence is high, but functional impact is limited. MATERIAL AND METHOD: A single-center retrospective study included all patients undergoing RHR for acute radial head fracture between 2008 and 2017: 53 patients, with a mean age of 53.8±15.7 years [range, 21-85 years]. At a minimum 2 years' follow-up, patients were assessed clinically on joint range of motion and Mayo Elbow Performance Score (MEPS) and radiologically on standard radiographs. Associations between RNO and various parameters were assessed. RESULTS: At a mean 46.7±19.8 months' follow-up [range, 24-84 months], RNO was found in 54.7% of cases (29/53), with mean 4.0 ±2.8mm distal extension [range, 1.2-13.4mm], corresponding to 13.4±7.3% of stem height [range, 2.7-27.7%]. RNO at last follow-up was not significantly associated with reduced flexion-extension (121.9° versus 114.0°; p=0.11), pronation-supination (152.6° versus 138.3°; p=0.25) or MEPS (84.7 versus 84.8; p=0.97), or with higher rates of postoperative complications (11/29 (37.9%) versus 7/24 (29.2%); p=0.782) or surgical revision (11/29 (37.9%) versus 10/24 (41.7%); p=0.503). RNO was significantly associated with cementless fixation (19/29 (65.5%) versus 7/24 (29.2%); p=0.01), unipolar prosthesis (21/29 (72.4%) versus 7/24 (29.2%); p=0.002), high filling-ratio, whether proximal (88% versus 77%; p=0.002), middle (84% versus 75%; p=0.007) or distal (69% versus 59%; p=0.032), and shorter radial stem (33.2mm versus 46.3mm; p=0.011). No demographic parameters showed significant association with RNO at last follow-up. CONCLUSION: RNO was frequent after RHR, but without clinical or radiological impact in the present series. The risk factors identified here argue for involvement of stress shielding. LEVEL OF EVIDENCE: IV, cohort study.

Radial head replacement - A comprehensive review.

Background: Radial head fractures represent 1-4% of all adult fractures and 1/3rd of elbow fractures (Kaas et al., 2010). Radial head is an important secondary stabilier of the elbow. The aim of the treatment of radial head fractures is to achieve stability and good functional outcome. Radial head replacement (RHR) is indicated when robust reconstruction and fixation of the fracture fragments is not possible. Methods: This article explores history and evolution, anatomical considerations, biomechanics, implant designs, indications, surgical outcomes and controversies in radial head replacement based on current evidence. Results: There is a wide range of RHR designs available without conclusive evidence to support the superiority of one design over the other. Ranges of motion, functional outcomes and complication were comparable among different designs with a high incidence of complications reported in many studies. Conclusion: RHR remains a good option in unreconstructible radial head fractures, with potential to regain excellent function. It is imperative to continue with the quest to innovate and improve on current designs, to reduce complications in the long term.

Early to midterm radiographic loosening of the press fit radial head prosthesis.

BACKGROUND: Radiographic loosening is frequently seen around the radial head (RH) implant. The hypothesis of this study was that radiographic loosening will be more frequent in patients in which the RH prosthesis was implanted due to elbow trauma leading to instability that required lateral collateral ligament repair (LCL). MATERIALS AND METHODS: A retrospective review of the patients who had RH implantation between 2012 and 2019 was performed. Evaluation included evidence of radiographic loosening, stress shielding, formation of heterotopic ossification, and rate of removal of the implant. Range of motion of the elbow at the latest follow up was also recorded. RESULTS: At a mean follow up of 18 months (range 1.4 - 80) eight out of 25 patients had radiographic loosening around the implant. The radial head implant was removed in 8 patients (in 3 due to painful radiographic loosening, in 4 due pain without radiographic loosening and in 1 due to infection). Radiographic loosening around the RH implant had no association with LCL repair (p=0.18) or future removal of implant (p=0.18) or the diagnosis of Monteggia lesion (p=0.68). In addition, removal of the RH implant had no association with prior LCL repair (p=0.60) or the diagnosis of Monteggia lesion (p=0.15). Stress shielding was seen in 5 patients and was of no clinical significance. Heterotopic ossification was seen in 12 patients and was classified as Class I in 3, IIA in 3, IIC in 6, according to the Hastings Classification. The average flexion-extension arc was 23° to 130°, and average pronation-supination was 76° to 69°. CONCLUSION: One third of the patients had radiographic loosening around the RH implant at a mean follow up of 18 months. Pain with or without radiographic loosening were the main reasons for removal of the implant. No associations were found between the development of radiographic loosening and LCL repair at the time of RH replacement. Limitations of this study are: (a) the retrospective design (b). the small sample size and the possibility of a type II statistical error.

The changing epidemiology of radial head replacement over a 22-year period in Scotland.

BACKGROUND: Radial head replacement is used to confer joint stability in the management of acute unstable elbow fractures and dislocations associated with instability. We determined the annual incidence of radial head replacement over a 22-year period in a defined population. MATERIALS AND METHODS: Hospital episode statistics were collected prospectively at a national level. This database was retrospectively examined to determine the annual incidence of radial head replacement over the study period in adults over 16 years of age. RESULTS: A total of 615 radial head replacements were performed over the 22 years studied. The overall incidence was 0.65/100,000/year (95% confidence interval, CI, 0.50-0.71). The average adult population during the period was 4,270,593. There was a steady and statistically significant increase in the incidence of radial head replacement over the study period (r 2 = 0.816; p < 0.0001). This incidence was significantly greater in women than men (odds ratio 1.46, 95% CI 1.25-1.72; p < 0.001). The peak incidence in men was 0.87/100,000 population/year in the fifth decade of life while in women the peak incidence was in the seventh decade of life (1.38/100,000 population/year). CONCLUSION: The incidence of radial head replacement has increased steadily over 22 years. We hypothesise that this represents an evolving understanding of the role of radial head replacement in acute trauma in the context of emerging literature during the study period.

Retrospective review of pyrocarbon radial head replacement.

Background: Radial head arthroplasty is the preferred surgical management for complex, unreconstructable radial head fractures. There has been increasing use of pyrocarbon prostheses, with potential tribology and modulus advantages over metallic counterparts. This study aims to assess clinical and radiological outcomes for radial head replacement after trauma using a modular, uncemented pyrocarbon prosthesis. Materials and Methods: Between September 2009 and March 2020, a consecutive series of 22 trauma cases were available for review. Patients underwent radial head arthroplasty using a pyrocarbon prosthesis (Ascension Modular Radial Head System, Austin, TX). Recorded outcomes included clinical assessment, radiological evaluation, and patient-reported outcome measures specific to elbow function. Results: Twenty-two patients (7 male, 15 female) with an average age of 51 years (range 21-64) were analyzed with a minimum 12 months of follow-up. All patients had complex radial head fractures, categorized as a Mason 3 or 4 injury. At follow-up, mean elbow range of motion included flexion 130° (range 100°-150°), extension 19° (0-50°), pronation 73° (30°-90°), and supination 70° (10°-90°). The mean Mayo Elbow Performance Index score was 83 (55-100), and Disabilities of the Arm, Shoulder and Hand score was 22 (2.5-60). Radiological evaluation showed 14 patients with asymptomatic proximal neck resorption and two patients with radiological stem loosening. In total, 3 of 22 implants were revised-2 were excised, and 1 revised to a long stem for traumatic implant fracture. Conclusion: Pyrocarbon radial head arthroplasty provided reliable functional results for patients after unreconstructable radial head fracture. The unique potential for fracture of the prosthesis should be considered in long-term follow-up, with appropriate activity advice to patients.

[Short-term effectiveness of free radial head reconstruction of coronoid process combined with artificial radial head replacement in treatment of complex terrible triad of elbow].

OBJECTIVE: To investigate the short-term effectiveness of free radial head reconstruction of coronoid process, artificial radial head replacement, and ulna olecranon internal fixation in the treatment of the complex terrible triad of the elbow. METHODS: Retrospective analysis was made on the clinical data of 12 patients with complex terrible triad of the elbow treated with free radial head reconstruction of coronoid process, artificial radial head replacement, and ulna olecranon internal fixation between April 2011 and April 2018. There were 8 males and 4 females with an average age of 44.5 years (range, 26-62 years). The causes of injury included 5 cases of traffic accident, 7 cases of falling from hight. The Regan-Morrey classification of ulnar coronoid process fractures was type Ⅲ; Mason classification of radial head fractures was type Ⅲ in 7 cases and type Ⅳ in 5 cases. The time from injury to operation was 5-14 days, with an average of 6.0 days. The operation time, intraoperative blood loss, and complications were recorded. After operation, X-ray film of elbow joint was reexamined, fracture healing condition was observed, and fracture healing time was recorded. The flexion, extension, and rotation of the elbow joints on the healthy and affected sides were recorded and measured. The elbow function was evaluated according to Mayo elbow function score. RESULTS: The operation time was 90-140 minutes (mean, 110 minutes); the intraoperative blood loss was 100-300 mL (mean, 150 mL). None of the patients had vascular injury during the operation. One patient developed numbness in the ulnar nerve innervation area and recovered completely after symptomatic treatment for 1 week. All the 12 patients were followed up 12-22 months, with an average of 16 months. At last follow-up, the fracture healed completely, 1 patient developed ectopic ossification of elbow joint, and 2 patients developed traumatic arthritis of elbow joint. No internal fixation-related complications occurred. There was no significant difference in the range of motion of elbow flexion, extension, pronation, and supination between the affected and healthy sides ( P>0.05). The median Mayo elbow function score was 96, and the interquartile range was (94, 97), and the excellent and good rate was 91.7%. CONCLUSION: For patients with complex terrible triad of the elbow with ulna coronoid process fractures of Regan-Morrey type Ⅲ and radial head fractures of Mason type Ⅲ, Ⅳ combined with ulna olecranon fractures, the free radial head reconstruction, artificial radial head replacement, and ulna olecranon internal fixation, through active rehabilitation function exercise after operation, can achieve more satisfactory short-term effectiveness.