Isolated anterior dislocation of the radial head (case report)

We report the case of an isolated post traumatic radial head dislocation in a 5 year old child. Clinical examination and the X ray results allow the diagnosis which can be unnoticed. The reduction by external maneuvers avoids the surgical treatment which remains the gold standard for chronic dislocation.

Operative treatment of Mason Type III radial head fractures - A comparative analysis using PROMIS

Objectives

The purpose of this study is to evaluate the outcomes of operatively treated Mason Type III radial head fractures. Additionally, this project seeks to assess efficacy of PROMIS in evaluating post-operative outcomes for this patient population.

Methods

A total of 143 patients who underwent operative treated Mason Type III radial head fractures were analyzed retrospectively. PROMIS physical function (PF), PROMIS upper extremity (UE), PROMIS pain interference (PI), demographic variables, and range of motion were collected and analyzed over 12-month follow-up.

Results

Radial head arthroplasty (RHA) was performed on 89 patients, open reduction and internal fixation (ORIF) was performed on 47 patients, and radial head excision was performed on 7 patients. Among the RHA patients, PROMIS PF, PI and UE demonstrated a change of -1.33 (p < 0.05), -1.48 (p < 0.05), and 2.23 (p < 0.05) respectively from injury to 12-months. Among the ORIF patients, PROMIS PF, PI and UE demonstrated a change of 3.22 (p < 0.05), -1.56 (p < 0.05), and 2.09 (p < 0.05) respectively from injury to 12-months. At the pre-operative and 12-month visits, the RHA group demonstrated lower PROMIS PF scores 34.75 vs 38.02 (p < 0.05) and 33.42 vs 41.24 (p < 0.05) respectively. Ther was no difference in PROMIS PI, UE, or elbow range of motion between the two groups at 6- or 12-month follow-up (p > 0.05).

Conclusion

Comparing the RHA and ORIF groups, there was no difference in PROMIS PI or UE scores nor was there a clinically significant improvement at the 6- or 12-month mark. The ORIF group demonstrated improved PROMIS PF at all follow-up periods and did show a clinically significant improvement. Patient Acceptable Symptom State (PASS) correlated only with PROMIS UE at 6- and 12- months for both groups.

Irreducible anteromedial radial head dislocation without fracture caused by transposed biceps tendon in an adult: A case report and literature review

Irreducible anteromedial radial head dislocation (IARHD) caused by transposed biceps tendon is rare. Delayed diagnosis and surgical failure often occur. A 46-year-old fisherman presented with 10 days history of painful swelling and restricted movement of his right elbow due to strangulation injury by a fishing boat cable. On examination, the images of the right elbow reveals in a "semi-extended and pronated" elastic fixation position. Radiography and 3-dimensional reconstruction CT reveals an isolated anteromedial radial head dislocation with extreme protonation of the radius and the bicipital tuberosity towards the posterior aspect of the elbow joint, and MRI shows biceps tendon wrapping around the radial neck, similar to umbilical cord wrapping seen in newborns. The Henry approach was applied for the first time to reduce the biceps tendon. The patient achieved a good functional recovery at 26 months, which represents the first reported case of IARHD without fracture caused by biceps tendon in an adult. In treatment of IARHD, attention should be paid to the phenomenon of biceps tendon transposition. Careful clinical examination, comprehensive imaging modalities, and appropriate surgical approach are the keys to successful management.

Early range of motion results in good elbow function following conservative treatment of non-displaced radial head fractures

INTRODUCTION

The aim of this study was to evaluate the range of motion (ROM), elbow function and predictors for good elbow function after conservative treatment of non-displaced radial head fractures.

MATERIAL AND METHODS

All patients with non-displaced radial head fractures (displacement < 2 mm), that were diagnosed between January 1st 2017 and December 31st 2021 in a level I trauma center, were included in this retrospective case series and the charts were evaluated for ROM and elbow function. Elbow function was categorized as "good" or "bad" depending on the ROM measured defined by Morrey et al. Overall, 73 patients (33 male, 40 female) with an average age of 38 years (+/- 13 years) could be included.

RESULTS

Conservative treatment had good clinical results for ROM and elbow function. After 6 weeks mean flexion was 131° (SD 13°), extension 8° (SD 7°), Pronation 83° (SD 11°) and Supination 83° (SD 13). Patients with a good elbow function after one week showed a good elbow function after completing the treatment.

CONCLUSIONS

A clinical assessment after one week should always be performed and the study showed that it is a good predictor for good elbow function. In cases of bad elbow function further controls should be considered.

Partial articular fractures of the radial head: How to understand them using computed tomography

BACKGROUND

The optimal treatment for different types of displaced partial articular radial head fractures is still debatable. Fractures involving the articulating portion of the radial head can be defined also as bi-articular and are often underestimated. Moreover, the complete loss of periosteal contact between fracture fragments is a marker of instability. Available classifications do not emphasize these aspects. The purpose of the present study is to describe two assessment methods to identify fractures involving the articulating portion of the radial head and complete loss of periosteal contact with the help of 2D-3D CT scan. The second purpose is to propose a classification of the displaced partial articular radial head fractures basing on these two assessment methods.

HYPOTHESIS

We hypothesize that the proposed classification is reliable.

PATIENTS AND METHODS

By observing the position of the bicipital tuberosity with respect to the ulna in reference to the coronal plane in the 3D-CT scan and by observing the location of the fracture fragment in the 2D axial scan, it is possible to understand if a displaced partial articular fracture involves the articulating portion of the radial head. Also, it is possible to understand the presence or absence of a complete loss of periosteal contact between the two fracture fragments by observing the coronal and sagittal 2D-CT scans. We identified 20 displaced partial articular radial head fractures on a series of 149 patients with radial head fractures. Following the above-described assessment methods, these 20 fractures were classified in three subgroups. Also, seven evaluators were asked to use these assessment methods to classify these 20 fractures in the three subgroups, in order to evaluate inter- and intra-observer agreement.

RESULTS

Eight fractures involved the non-articulating portion of the radial head with complete loss of periosteal contact, eight involved the non-articulating portion of the radial head without complete loss of periosteal contact, and four involved the articulating portion of the radial head with or without complete loss of periosteal contact. The kappa for intra-observer reliability ranged from 0.46 to 0.84. The average kappa for inter-observer reliability was 0.570 (range: 0.526 to 0.676). The Kendall's coefficient for inter-observer concordance was 0.673.

DISCUSSION

Prognostically, displaced partial fractures of the articulating portion of the radial head could differ from the other types, regardless of whether or not there is a complete loss of periosteal contact. Underestimating this fracture pattern can lead to poor results due to risk of forearm rotation blockage. Moreover, underestimating complete loss of periosteal contact in displaced partial fractures of the non-articulating portion of the radial head could lead to poor results. The described evaluation methods have moderate reliability, but can represent, along with other described methods, a good starting point to better understand and treat these insidious fractures.

LEVEL OF EVIDENCE

III; retrospective study.

Does the polarity of radial head arthroplasty affect functional outcomes?: a systematic review and meta-analysis

Background

Radial head arthroplasty allows a high degree of customizability, and implant polarity has emerged as an important variable. The purpose of this meta-analysis was to evaluate differences in functional and clinical outcomes between patients receiving monopolar and bipolar radial head prosthetic implants.

Methods

A systematic review and meta-analysis were employed, and 65 articles were identified in three databases. Twelve articles contained non-English or insufficient text and were consequently excluded, and 20 others did not contain sufficient data or follow-up. The remaining 33 articles were qualitatively and quantitatively reviewed.

Results

In total, 33 populations were identified, with 809 unduplicated patients: 565 with monopolar and 244 with bipolar implants. In these respective patients, the mean follow-up was 40.2 and 56.9 months. Average Mayo Elbow Performance Score were 86.7 and 87.4 (P=0.80), respectively; average Disability of the Arm, Shoulder, and Hand scores were 17.9 and 14.7 (P=0.47), and average final flexion/extension arcs were 119.4° and 118.7° (P=0.48). Revision rates were 4.07% and 6.56%, while complication rates were 19.65% and 20.08% in the respective monopolar and bipolar patients. These increased relative risks associated with bipolar implants were not significant.

Conclusions

Radial head implant polarity does not appear to affect functional outcomes. While bipolar prosthetic design may increase the risks of revision and complications, the increases were not significant.

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

INTRODUCTION

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

MATERIAL & METHOD

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

RESULTS

Stress shielding was identified in 60 patients. Mean preoperative MD:CW, CFI, and CF were 0.55 ±0.09, 1.05 ±0.18 and 0.79±0.11, respectively. The presence of SS was significantly associated with MD:CW (aOR=13.66; p=0.001), and expansion of the stem (aOR=3.78; p=0.001). The amount of the SS was significantly correlated with expansion of the stem (aβ 4.58; p<0.001).

CONCLUSIONS

Our study found that MD:CW was an independent risk factor of SS after Mopyc RHA. Patients with longer and larger diameter (auto-expansion) Mopyc stems were also at significantly increased risk of SS. Further studies involving multiple implants designs are needed to confirm the preliminary observations presented in the current study.

Added Transverse Screw in Tripod Construct Increases Stiffness in Mason III Radial Head Fractures: A Finite Element Analysis

BACKGROUND

The tripod screw configuration has been shown to offer similar stiffness characteristics to a laterally placed plate. However, concern has been raised that the construct may be prone to failure in scenarios where the screw intersects at the fracture line. We performed a finite element analysis to assess potentially ideal and unideal screw placements in the tripod construct among Mason III radial head fractures.

METHODS

A 3-dimensional proximal radius model was developed using a computed tomography scan of an adult male radius. The fracture site was simulated with a uniform gap in transverse and sagittal planes creating a Mason Type III fracture pattern comprising 3 fragments. Three configurations were modelled with varying screw intersection points in relation to the radial neck fracture line. A fourth configuration comprising an added transverse interfragmentary screw was also modelled. Loading scenarios included axial and shear forces to simulate physiological conditions. Von mises stress and displacement were used as outcomes for analysis.

RESULTS

Some variation can be seen among the tripod configurations, with a marginal tendency for reduced implant stress and greater stiffness when screw intersection is further from the neck fracture region. The construct with an added transverse interfragmentary screws demonstrated greater stiffness (2269N/mm) than an equivalent tripod construct comprising three screws (612N/mm).

CONCLUSION

The results from this study demonstrate biomechanical similarity between tripod screw constructs including where screws intersect at the radial neck fracture line. An added fourth screw, positioned transversely across fragments increased construct stiffness in our model.

Anterior radial head subluxation in primary elbow osteoarthritis

PURPOSE

To investigate elbows with primary osteoarthritis (OA) for the presence of anterior radial head subluxation.

METHODS

A total of 71 patients with elbow osteoarthritis and 45 with lateral epicondylitis were initially identified. The baseline characteristics and preoperative elbow X-rays of consecutive patients that had been clinically confirmed with elbow OA or lateral epicondylitis between March 2011 and January 2020 were then retrospectively reviewed. The radiocapitellar ratio (RCR; the ratio of the displacement of the radial head about the diameter of the capitulum) was calculated using lateral views. These RCR values were compared between the OA and lateral epicondylitis cases.

RESULT

A significant increase was detected in RCR values between patients in elbow OA and the control group (13.2% (± 10.6) vs -1.2% (± 6.8), P<0.001). Based on receiver operating characteristic curves, RCR values had an excellent area under the curve (0.89) for the detection of elbow OA (Youden index, 0.69; sensitivity, 89%; specificity, 80%). Based on the ROC curve, the cutoff value of RCR was 0.04. Patients with RCR ≥ 0.04 had a significantly higher proportion of cases with elbow OA (risk ratio, 31.50 [95% CI, 11.17-88.82]) than those with RCR ˂ 0.04 (P ˂ 0.001).

CONCLUSION

Radial head subluxation is a radiographic finding associated with elbow OA and RCR ≥ 0.04 could be used as an aetiological factor for elbow OA diagnosis.

Open reduction and internal fixation of modified Mason type III/IV radial head fractures with more than three fragments: an analysis of the clinical outcome and reoperation rate

PURPOSE

It is generally accepted that a radial head fracture (RHF) with more than three parts is not suitable for repair; therefore, most authors suggest straightforward radial head arthroplasty (RHA). With up to 20% risk for reoperation after RHA, improvement in reduction and fixation techniques may represent a valuable alternative before further extending the indications for arthroplasty. To determine the functional results and radiological failure rate after osteosynthesis of multi-fragmentary RHF with more than three articular fragments. We specifically determined (1) the one-year Broberg and Morrey functional elbow score, (2) duration of fracture healing, (3) complication rate, and (4) number of patients converted to RHA.

METHODS

This study is a retrospective single-center case series. All patients who underwent primary osteosynthesis for RHF between 2012 and 2019 were included. Nine patients with an average age of 52 years had an average clinical and/or radiological follow-up of 49 months.

RESULTS

The preoperative imaging identified nine fractures with four fragments. Three patients underwent osteosynthesis with plates and screws, whereas six patients underwent osteosynthesis with only screws. The mean Broberg and Morrey score was 95 points. Overall, eight of the nine patients had satisfactory results. All patients retained their radial heads and showed radiological fracture healing. Only two patients presented with low-grade complications requiring no further surgery.

CONCLUSION

Our study showed that osteosynthesis of RHF with up to four fragments can achieve good functional results with a low complication rate and seems to be a valid alternative to RHA.

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

BACKGROUND

Radial 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 PRESENTATION

A 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.

CONCLUSION

In 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.

Terrible triad injury of the elbow: a spectrum of theories

For more than one century, understanding the injury mechanism leading to the terrible triad of the elbow (TTE) was a significant challenge for surgeons. We aimed to summarize: (1) the history of the treatment of TTE and (2) the increasing scientific knowledge that supported its evolution. Five electronic databases were searched between 1920 and 2022. Results were reported as a comprehensive review of the relevant literature. Between 1940 and 1980, surgical exploration allowed observation of complex elbow instability involving both radial head, coronoid process, and ligament(s) injuries. In 1966, Osborne introduced the concept of posterolateral rotatory instability as the first mechanism injury to explain the complex elbow instability. From 1980 to 1995, a biomechanical revolution by American pioneers critically improved our understanding of elbow instability. After 1992, a few unifying theories and surgical protocols were provided, but those have divided the surgeons' population. The formalization of the TTE treatment allowed avoiding of terrible short-term outcomes. However, post-traumatic osteoarthritis (PTOA) at long-term follow-up is still an issue. No consensual surgical protocol for the treatment of TTE has been widely accepted. While the outcomes of the TTE have been improved, the rate of PTOA at long-term follow-up is still high regardless of the treatments. The terrible triad has given way to the subtle triad with persistent microinstability of the elbow. The next challenge for elbow surgeons is to diagnose and fix this persistent subclinical instability after surgery in order to prevent the onset of PTOA.

[Terrible triad injuries]

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

Delayed dislocation of the radial head associated with malunion of distal radial fracture: A case report

BACKGROUND

Traumatic radial head dislocation (RHD) is a well-described injury in the pediatric population. It is usually associated with an injury to the ulna in Monteggia fracture-dislocation, although it can occur as an isolated injury. Traumatic RHD with ipsilateral radial shaft fracture has rarely been reported. Delayed RHD secondary to the malunion of an isolated radial shaft fracture is extremely rare.

CASE SUMMARY

We report a 9-year-old boy with limited pronation of the right elbow. The patient was diagnosed with delayed RHD associated with the malunion of a distal radial fracture. Since the annular ligament was disrupted with forearm rotation causing subluxation of the radial head, a modified double-strip Bell Tawse procedure was performed to reconstruct the annular ligament without corrective osteotomy for the malunited site. Four years after surgery, the angulation deformity of the distal radius was corrected with the restoration of the normal curvature of the radius. There was no recurrence of RHD.

CONCLUSION

Annular ligament reconstruction without corrective osteotomy could reduce RHD and restore the normal curve of the radial shaft in children with delayed dislocation of the radial head associated with malunion of the radial shaft. Annular reconstruction using double triceps tendon strips might be useful for maintaining a more stable reduction by augmenting anterolateral parts.

Short- to Mid-term Results of Patient-Specific Polymethylmethacrylate Radial Head Prosthesis in Complex Radial Head Fractures Using 3-Dimensional Mold System

Background: We used antibiotic-impregnated polymethylmethacrylate (PMMA) bone cement to make a patient-specific radial head prosthesis (RHP) by applying the 3-dimensional (3D) designing technique in patients with Mason types 3 and 4 radial head fractures. The aim of this study is to report the short- to mid-term outcomes of this procedure. Methods: This is a prospective study of all patients who underwent a patient-specific PMMA bone cement RHP at our institute over a 1-year period from May 2017 to June 2018. The outcome measures included range of motion, grip strength, visual analogue scale (VAS) for pain at rest and at activity, disabilities of arm, shoulder and hand (DASH) score and Mayo elbow performance index (MEPI). Radiographs of the elbow ere obtained at final follow-up and any complications were also recorded. Results: Our study included eight patients with a mean follow-up of 18 months (13-20 months). The mean arc of extension-flexion and supination-pronation of the operated side was 86% and 96% of the unaffected side, respectively. Mean grip strength was 86% of the unaffected side. The mean VAS for pain at rest was 0 and during activity was 2 out of 10. The mean DASH score was 8 out of 100 (0-22), showing minimal disability and ability to cope with most living activities. MEPI showed four excellent, three good and one fair result. One patient complained of proximal forearm pain that appeared 1 year after surgery. No patient complained of ulnar nerve symptoms requiring intervention. No RHP was removed during the follow-up. Conclusions: PMMA RHP can be used safely as an alternative to metal prostheses to restore valgus and axial stability of the forearm. The use of 3D printing optimised the design and surgical technique of radial head arthroplasty, and we need further studies to assess the long-term follow-ups. Level of Evidence: Level IV (Therapeutic).

Recognition of the pattern of complex fractures of the elbow using 3D-printed models

AIMS

This study aimed to answer the following questions: do 3D-printed models lead to a more accurate recognition of the pattern of complex fractures of the elbow?; do 3D-printed models lead to a more reliable recognition of the pattern of these injuries?; and do junior surgeons benefit more from 3D-printed models than senior surgeons?

METHODS

A total of 15 orthopaedic trauma surgeons (seven juniors, eight seniors) evaluated 20 complex elbow fractures for their overall pattern (i.e. varus posterior medial rotational injury, terrible triad injury, radial head fracture with posterolateral dislocation, anterior (trans-)olecranon fracture-dislocation, posterior (trans-)olecranon fracture-dislocation) and their specific characteristics. First, fractures were assessed based on radiographs and 2D and 3D CT scans; and in a subsequent round, one month later, with additional 3D-printed models. Diagnostic accuracy (acc) and inter-surgeon reliability (κ) were determined for each assessment.

RESULTS

Accuracy significantly improved with 3D-printed models for the whole group on pattern recognition (acc_2D/3D = 0.62 vs acc_3Dprint= 0.69; Δacc = 0.07 (95% confidence interval (CI) 0.00 to 0.14); p = 0.025). A significant improvement was also seen in reliability for pattern recognition with the additional 3D-printed models (κ_2D/3D = 0.41 (moderate) vs κ_3Dprint = 0.59 (moderate); Δκ = 0.18 (95% CI 0.14 to 0.22); p ≤ 0.001). Accuracy was comparable between junior and senior surgeons with the 3D-printed model (acc_junior = 0.70 vs acc_senior = 0.68; Δacc = -0.02 (95% CI -0.17 to 0.13); p = 0.904). Reliability was also comparable between junior and senior surgeons without the 3D-printed model (κ_junior = 0.39 (fair) vs κ_senior = 0.43 (moderate); Δκ = 0.03 (95% CI -0.03 to 0.10); p = 0.318). However, junior surgeons showed greater improvement regarding reliability than seniors with 3D-printed models (κ_junior = 0.65 (substantial) vs κ_senior = 0.54 (moderate); Δκ = 0.11 (95% CI 0.04 to 0.18); p = 0.002).

CONCLUSION

The use of 3D-printed models significantly improved the accuracy and reliability of recognizing the pattern of complex fractures of the elbow. However, the current long printing time and non-reusable materials could limit the usefulness of 3D-printed models in clinical practice. They could be suitable as a reusable tool for teaching residents.Cite this article: Bone Joint J 2023;105-B(1):56-63.

Terrible triad injury of the elbow: a historical perspective

PURPOSE

The aims of this study are to summarize (1) the history of terrible triad injury (TTi) treatment and (2) the clinical and biomechanical data that engendered its evolution.

METHODS

A literature search was performed using five electronic databases. Results were discussed as a chronologic review of the relevant literature between 1920 and 2022.

RESULTS

In 1962, Osborne was the first to describe a link between elbow dislocation, radial head fracture, and lateral collateral ligament complex injury via a novel mechanism: posterolateral rotatory instability (PLRI). Given that untreated elbow instability leads to post-traumatic osteoarthritis (PTOA), there has been increasing interest in elbow biomechanics since the 1980s. Data from studies in that period revolutionized the approach to elbow instability. The authors demonstrated that TTi could occur via a PLRI mechanism with a disruption of the lateral collateral ulnar ligament and a functionally competent anterior medial collateral ligament (aMCL). Since the 1990s, due to the difficulty in identifying its pathoanatomic features, some began to speculate about a sequence of injuries and mechanisms leading to TTi. However, the clinical literature has largely been unable to reproduce in vitro findings describing the pathomechanics of TTi. Some aspects of treatment remain controversial including systematic coronoid and aMCL repair.

CONCLUSION

Despite a growing body of biomechanics data, there is no widely accepted surgical protocol for the treatment of TTi. Functional outcomes among patients have greatly improved. Better diagnosis and treatment of infra-clinical instability after a TTi may be an important stepping stone to prevent the onset of moderate/severe PTOA.

Autologous replacement of the head of the radius-proximal fibula versus second metatarsal base: an anatomic feasibility study

INTRODUCTION

This study investigated the anatomic feasibility of a new surgical therapy option for radial head arthrosis using an autologous vascularized bone graft of the second metatarsal and proximal fibula to recreate the proximal radiohumeral joint.

MATERIALS AND METHODS

Upper and lower extremities of eleven body donors were evaluated using CT prior to anatomic dissection. Several distinct anatomic parameters were measured on the ipsi- and contralateral radial and fibular head and the second metatarsal base: bone diameter, articular surface diameter, head height, metaphyseal (neck) diameter, articular surface radius, total articular surface area, and angulation of the articular surfaces (facet). Each dissection phase was photographed in a standardized fashion and all measurements were repeated by direct caliper-measurements.

RESULTS

When comparing the proximal radius and fibula to search for anatomic similarities, similar values were found in the maximum articular surface diameter and minimum and maximum measures of the neck diameter. Comparing the proximal radius and the second metatarsal, statistically similar values were found in the maximum neck diameter performing direct measurements and CT evaluation, the maximum head diameter in CT evaluation and the articular facet angulation.

CONCLUSIONS

Neither the proximal fibula nor the base of the second metatarsal are ideal bone grafts for replacement of the head of the radius. The base of the second metatarsal might be a bit more suitable as a potential donor since the angulation of the proximal articular facet is similar to that of the radius.

LEVEL OF EVIDENCE

Level IV, anatomic study.

Terrible triad of the elbow and associated variants: a systematic review

Background

The terrible triad of the elbow (TTE) is a complex injury consisting of simultaneous elbow dislocation or subluxation, radial head fracture, and coronoid fracture. During the initial assessment of a TTE, the typical severity of presenting pain, swelling, and limited range of motion may limit the ability to perform a thorough physical examination and thus divert a clinician's attention away from additional injuries to the ipsilateral upper extremity. Therefore, the purpose of this study was to review the literature for reported cases of concomitant ipsilateral upper extremity injuries associated with a TTE and discuss various strategies to increase clinician awareness to avoid underdiagnosis and missed diagnoses.

Methods

A systematic review of five databases in four languages (English, Spanish, French, and Portuguese), from inception to May 2021, was conducted. Articles describing a TTE with a concomitant osseous, chondral, ligamentous, or musculotendinous injury occurring on the ipsilateral upper extremity were included. The patients were divided into two groups, those presenting with a classic TTE and concomitant ipsilateral upper extremity injury (group 1) and those in whom a TTE variant was described (group 2). A TTE variant was defined as a combination of osseous and/or chondral injuries to the elbow other than the classic description of TTE, in which at least two of the three classical elements of a TTE (elbow dislocation, coronoid fracture, and radial head fracture) were present in addition to other unique elbow osteoarticular injury.

Results

Nineteen articles met inclusion criteria and were further analyzed. A total of 27 patients were analyzed, 23 from group 1 and 4 from group 2. Overall, 33 concomitant injuries were documented in group 1, the most common being an olecranon fracture (27.3%), followed by Essex-Lopresti injury, triceps tendon avulsion, and carpal fracture-dislocation with 4 (12.1%) cases each. Group 2 had four patients, all of whom presented with a unique variant of the classically described TTE.

Conclusion

Despite a characteristic radiographic appearance of the classic TTE, additional injuries of the ipsilateral extremity or variants of the classic TTE may be easily missed, especially in cases resulting from high-energy mechanisms of injury. By analyzing the available data on associated injuries and variants that may occur with a TTE, we hope to increase awareness so that clinicians may recognize these less common but more complex injury patterns.

Clinical long-term results of radial head arthroplasty in comminuted radial head fractures

Modern radial head prostheses have recently become more common in the treatment of comminuted radial head fractures. The goal of this study was to evaluate how well the EVOLVE^® modular metallic radial head implant prosthetic restores the functional range of motion and stability of the elbow. 30 patients with comminuted radial head fractures received an arthroplasty with an EVOLVE^® prosthesis in our institution. 20 of those patients were available for long-term follow-up (mean > 10 years). The outcomes were assessed on the basis of pain, motion, and strength. The overall outcome was scored with functional rating scores. According to the Broberg-Morrey elbow evaluation score, after a mean follow-up period of 10.2 years, ten (50.0%) patients were rated as very good, four (20.0%) as good, six (30.0%) as satisfactory, and none as poor. In the long-term results the Broberg-Morrey score increased from 79 (in short-term results) to 89 points. The Disabilities of the Arm, Shoulder, and Hand (DASH) outcome measure questionnaire showed an average of 16.2 points. Initially, patients had an extension deficit of 20°, which was reduced to 5° at the latest follow-up. In our long-term results, an improvement in the function of the elbow was observed after arthroplasty using a metallic modular radial head implant. Comminuted radial head fractures with elbow instability can be treated effectively with the EVOLVE^® radial head prosthesis, which restores stability in acute treatment. Our long-term results after 10.2 years demonstrate good functional outcome and low major complication rate. IV.

Diagnosis, treatment and complications of radial head and neck fractures in the pediatric patient

Radial head and neck fractures represent up to 14% of all pediatric elbow fractures and can be a difficult challenge in the pediatric patient. In up to 39% of proximal radius fractures, there is a concomitant fracture, which can easily be overlooked on the initial standard radiographs. The treatment options for proximal radius fractures in children range from non-surgical treatment, such as immobilization alone and closed reduction followed by immobilization, to more invasive options, including closed reduction with percutaneous pinning and open reduction with internal fixation. The choice of treatment depends on the degree of angulation and displacement of the fracture and the age of the patient; an angulation of less than 30 degrees and translation of less than 50% is generally accepted, whereas a higher degree of displacement is considered an indication for surgical intervention. Fractures with limited displacement and non-surgical treatment generally result in superior outcomes in terms of patient-reported outcome measures, range of motion and complications compared to severely displaced fractures requiring surgical intervention. With proper management, good to excellent results are achieved in most cases, and long-term sequelae are rare. However, severe complications do occur, including radio-ulnar synostosis, osteonecrosis, rotational impairment, and premature physeal closure with a malformation of the radial head as a result, especially after more invasive procedures. Adequate follow-up is therefore warranted.

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.

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.

Use of an external fixator during one-step surgical management of missed chronic Monteggia injuries

The incidence of untreated Monteggia fracture-dislocations is not insignificant. But there is no consensus as to the surgical indication and best surgical technique to use. Single-stage reduction of the radial head through an elbow arthrotomy and ulnar osteotomy is a complex surgical procedure that requires stabilization of the ulnar segments during every step of the intervention. Here, we describe the possibility of using an external fixator intraoperatively to facilitate the various steps of the procedure: (1) gradual distraction and angulation of the osteotomy site to allow thorough excision of any interposed capsular tissue, (2) stable hold on the ulnar fragments independent of the surgical assistant, which allows the stability of the radial head reduction to be tested in pronation and supination and (3) facilitation of plate fixation at the ulnar osteotomy site. LEVEL OF EVIDENCE: IV; case series.

A registry study on radial head arthroplasties in the Netherlands: Indications, types and short-term survival

BACKGROUND

This study aims to use the Dutch Arthroplasty Register data to report an overview of the contemporary indications and implant designs, and report the short-term survival of radial head arthroplasty.

METHODS

From the Dutch Arthroplasty Register, data on patient demographics, surgery and revision were extracted for radial head arthroplasties performed from January 2014 to December 2019. Implant survival was calculated using the Kaplan-Meier method.

RESULTS

Two hundred fifty-eight arthroplasties were included with a median follow-up of 2.2 years. The most common indication was a fracture of the radial head (178, 69%). One hundred thirty-nine (68%) of the prostheses were of bipolar design, and the most commonly used implant type was the Radial Head System (Tornier; 134, 51%). Of the 258 included radial head arthroplasties, 16 were revised at a median of six months after surgery. Reason for revision was predominantly aseptic loosening (9). The overall implant survival was 95.8% after one year, 90.5% after three years and 89.5% after five years.

DISCUSSION

For radial head arthroplasties, acute trauma is the most common indication and Radial Head System the most commonly used implant. The implant survival is 89.5% after five years.

Regional differences in the three-dimensional bone microstructure of the radial head: implications for observed fracture patterns

INTRODUCTION

A characterization of the internal bone microstructure of the radial head could provide a better understanding of commonly occurring fracture patterns frequently involving the (antero)lateral quadrant, for which a clear explanation is still lacking. The aim of this study is to describe the radial head bone microstructure using micro-computed tomography (micro-CT) and to relate it to gross morphology, function and possible fracture patterns.

MATERIALS AND METHODS

Dry cadaveric human radii were scanned by micro-CT (17 μm/pixel, isotropic). The trabecular bone microstructure was quantified on axial image stacks in four quadrants: the anterolateral (AL), posterolateral (PL), posteromedial (PM) and anteromedial (AM) quadrant.

RESULTS

The AL and PL quadrants displayed the significantly lowest bone volume fraction and trabecular number (BV/TV range 12.3-25.1%, Tb.N range 0.73-1.16 mm^-1) and highest trabecular separation (Tb.Sp range 0.59-0.82 mm), compared to the PM and AM quadrants (BV/TV range 19.9-36.9%, Tb.N range 0.96-1.61 mm^-1, Tb.Sp range 0.45-0.74 mm) (p = 0.03).

CONCLUSIONS

Our microstructural results suggest that the lateral side is the "weaker side", exhibiting lower bone volume faction, less trabeculae and higher trabecular separation, compared to the medial side. As the forearm is pronated during most falls, the underlying bone microstructure could explain commonly observed fracture patterns of the radial head, particularly more often involving the AL quadrant. If screw fixation in radial head fractures is considered, surgeons should take advantage of the "stronger" bone microstructure of the medial side of the radial head, should the fracture line allow this.

The effect of hemiarthroplasty implant modulus on contact mechanics: an experimental investigation

BACKGROUND

Hemiarthroplasties cause damage to the cartilage that they articulate against, which is a major limitation to their use. This study investigated the use of lower-stiffness materials to determine whether they improve hemiarthroplasty contact mechanics and thus reduce the risk of cartilage damage.

METHODS

Eleven fresh-frozen cadaveric upper extremities were disarticulated and fixed in a custom-built jig that applied a static load of 50 N to the radiocapitellar joint. Flexion angles of 0°, 45°, 90°, and 135° were tested with radial head implants made of cobalt-chrome (CoCr) and ultrahigh-molecular-weight polyethylene (UHMWPE) compared with the native radial head. A Tekscan thin-film sensor was used to measure the contact area and contact pressure between the radius and capitellum.

RESULTS

UHMWPE and CoCr were too stiff in the application of hemiarthroplasty, resulting in lower contact areas and higher contact pressures relative to the native joint. The native contact area was, on average, 42 ± 20 mm² larger than that of UHMWPE (P < .001) and 55 ± 24 mm² larger than that of CoCr (P < .001). UHMWPE had a contact area 13 ± 10 mm² greater than that of CoCr (P = .014).

DISCUSSION AND CONCLUSION

This study shows that even though UHMWPE has a stiffness several times lower than CoCr, the use of this material in hemiarthroplasty led to only a minor improvement in contact mechanics. Neither implant restored contact similar to the native articulation. Investigations into new materials to improve the contact mechanics of hemiarthroplasty should focus on materials with a lower stiffness than UHMWPE.

A hybrid technique combining intramedullary pinning with extramedullary plate fixation in unstable and comminuted radial head fractures following on-table reconstruction

Background

Management of comminuted radial fractures remains controversial. Currently, the emergence of on-table reconstruction technique has made fixation in comminuted radial head fractures more viable. However, the present study reported an intro-operative unstable displacement from the reconstructed radial head to the neck during plate fixation, characterized by a poor radiocapitellar contact and incongruity between the radial head and neck. A hybrid technique combining with intramedullary pining was performed in our study to restore the normal alignment and maintain the stability of fixation. Therefore, the purpose of this article aimed to prove the feasibility of unstable comminuted radial head fractures treated with the extramedullary plate and intramedullary pinning fixation using titanium elastic nails.

Methods

The clinical, functional and radiographic outcomes of the groups were compared during follow-up. The radiographic examination was conducted to evaluate the status of bone union, heterotopic ossification and post-traumatic arthritis. The functional assessment was performed to evaluate clinical effects, which included measurements of range of motion (ROM) in the elbow, Visual Analog Scale (VAS) score, Elbow Self-Assessment score (ESAS), Mayo Elbow Performance score (MEPS), and Disabilities of the Arm, Shoulder, and Hand (DASH)Outcome Measure score.

Results

Thirteen patients with unstable fractures were participated with an average follow-up of (38.6 ± 4.5) months for the experimental group and (32.0 ± 6.3) months for the control group, respectively. The functional outcomes in the experimental group, including MEPS and DASH, were significantly superior to the control group. However, no significant difference was observed in the elbow ROM and VAS score between two groups. In the last follow-up, one patient with post-traumatic arthritis rated as grades 1 and two with heterotopic ossifications were observed in the experimental group. In the control group, degenerative changes were observed in three cases (grade 1 in two cases and grade 2 in one case) and heterotopic ossifications rated as grade I were found in two patients.

Conclusion

Collectively, intramedullary pinning with extramedullary plate fixation is feasible in unstable comminuted radial head fractures, which can be considered as a remedial surgery for on-table reconstruction technique.

Radial head fractures

Radial head fractures are the commonest fractures in the elbow. They are often associated with other injuries: ligamentous, cartilaginous or other fractures. Associated injuries are important determinant of the management of the radial head fracture. These should be carefully looked for, diagnosed and treated. The original Mason classification for this fracture has been modified to include the associated injuries and their treatment. CT scan is a helpful diagnostic tool and should be used if available. Radial head fractures can be treated either conservatively or operatively (by excision, open reduction and internal fixation or prosthetic replacement). Undisplaced or minimally displaced fractures should be treated non-operatively. Internal fixation by headless cannulated screws is the preferred treatment for displaced fractures. It provides satisfactory biomechanical stability, can be done through a smaller incision, has less complications and lesser requirement of later removal of screws. Small number of fractures with comminution of neck would require plate fixation. Unfixable fractures in elderly can be treated by excision while such fractures in younger population or associated with significant soft tissue or bony injuries would require prosthetic replacement.

nonoperative treatment for Mason type 2 radial head fractures: a randomized controlled trial

BACKGROUND

The optimal treatment of isolated displaced partial articular radial head fractures remains controversial. The aim of this randomized controlled trial was to compare the functional outcome of operative treatment with nonoperative treatment in adults with an isolated Mason type 2 radial head fractures.

METHODS

In this multicenter randomized controlled trial, patients from 18 years of age with an isolated partial articular fracture of the radial head were randomly assigned to operative treatment by means of open reduction and screw fixation or nonoperative treatment with a pressure bandage. The primary outcome was function assessed with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Questionnaires and clinical follow-up was conducted at admission and at 3, 6, and 12 months.

RESULTS

In total, 45 patients were randomized, 23 patients to open reduction and screw fixation and 22 patients to nonoperative treatment with a pressure bandage. At 3, 6, and 12 months, patients treated operatively had similar functional outcomes compared to patients treated nonoperatively (DASH score at 12 months: 0.0 [0.0-4.2] vs. 1.7 [0.0-8.5]; P = .076).

CONCLUSIONS

Nonoperatively treated adults with an isolated Mason type 2 radial head fracture have similar functional results after 1 year compared with operatively treated patients. In addition, complication rates were low for both operative and nonoperative treatment.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level III Retrospective comparative treatment study.

Outcomes of press-fit radial head arthroplasty following complex radial head fractures

INTRODUCTION

Press-fit radial head arthroplasty (RHA) is increasingly popular in treating complex radial head fractures. This study assessed the outcome of RHA, including the outcome following re-operation, and explored potentially influencing factors.

HYPOTHESIS

Complex radial head fractures treated with press-fit radial head prosthesis would have a favourable outcome.

MATERIAL AND METHODS

Data on all consecutive patients treated with anatomic press-fit RHA from February 2002 to February 2015 were analysed. Post-surgery clinical and X-rays assessments included a post-discharge evaluation of function. Standardised methods implemented include the assessment of range of motion (ROM), the Mayo Elbow Performance Score (MEPS) and subjective satisfaction scales.

RESULTS

Forty-five patients were recruited and 71% were classified in Mason IV and 62.2% had the "terrible triad". Re-operation was performed in 26.7% and prosthesis removal in 15.6%. Mean follow-up was 140.8 months (95% CI 117.7-164) and prosthesis survival was 69.5% at 24 months. Mean MEPS before re-operations was 86.3±15.9. Pain and/or instability were the most common reasons for re-operation, and re-operations were significantly more frequent in patients having one or more "associated injuries" (p=0.05), but not the terrible triad; and in patients with radiological "loosening" signs (p<0.01). Subjective scores were relatively good in most patients, although the functionality perceived in the re-operation with implant removal group was rather low.

DISCUSSION

Several studies of complex radial head fractures treated with press-fit radial head prosthesis have also shown favourable results, but the patients in such studies generally had less severe lesions. Moreover, differently from previous reports, this study with a long follow-up has included a younger population with high functionality requirements. Pain and/or instability, as observed in several previous reports, were the most common reasons for re-operation, but contrary to the expectation, the terrible triad was not associated with unfavourable outcome.

CONCLUSION

Treatment of complex fractures with press-fit radial head prosthesis, including re-operation with implant removal yields satisfactory results. Most scores of functional and subjective outcome improved following the re-intervention and most patients returned to their usual occupation.

LEVEL OF EVIDENCE

Level IV; case series; treatment study.

Dysplasia epiphysealis hemimelica of the radial head: a rare case report

Background

Dysplasia epiphysealis hemimelica (DEH) is a rare benign overgrowth generally affecting the epiphyses and short bones of the lower limbs. DEH in the elbow joint is extremely rare, and to date, only three cases of DEH have been reported in the radial head.

Case presentation

In this study, we report a case of DEH located in the radial head of the right elbow of a 10-year-old boy, which was presented with elbow pain and limited range of motion. In clinical examination, an asymmetrical enlargement was observed over the elbow. The lesion was resected surgically, and the patient’s symptoms resolved afterward. The histologic analysis of the lesion confirmed the diagnosis of DEH.

Conclusion

This report highlights the role of DEH in the differential diagnosis of elbow pathologies, particularly its differentiation from osteochondroma.

Surgical treatment of terrible triad of the elbow

Terrible triad of the elbow associates posterior dislocation, radial head fracture and coronoid process fracture. It is a complex trauma, associating severe bone and ligament lesions, with high more-or-less long-term risk of residual instability, stiffness, pain and osteoarthritis. During the last 20 years, pathologic, biomechanical and clinical knowledge has greatly progressed. Prevention of these severe complications requires initial understanding of the lesion mechanism and precise analysis of all lesions. Surgery aims to restore perfect stability by sequential anatomic repair, enabling early mobilization to prevent onset of stiffness. The aims of the present paper were to summarize the anatomic and pathophysiological bases, highlight the crucial importance of the humeroradial column and lateral collateral ligament, and to determine the importance of the coronoid process. Some aspects of treatment are controversial: systematic medial collateral ligament repair, or use of an articulated external fixator. Finally, we propose a simple algorithm to guide repair.

Precision of computed tomography and cartilage-reproducing image reconstruction method in generating digital model for potential use in 3D printing of patient-specific radial head prosthesis: a human cadaver study

Background

A prosthetic replacement is a standard treatment for an irreparable radial head fracture; however, the surface mismatch of the commercially available designs is concerned for the long-term cartilage wear. The patient-specific implant created from 3D printing technology could be favorable in replicating the normal anatomy and possibly reduce such sequela. Our study aimed to assess the precision of the computed tomography (CT) and cartilage-reproducing image reconstruction method (CIRM) in generating digital models for potentially use in manufacturing the patient-specific prosthesis from 3D printing.

Methods

Eight intact  elbows (3 right and 5 left) from 7 formalin-embalmed cadavers (4 males and 3 females) with mean age of 83 years (range, 79–94 years) were used for this study. Computerized 3D models were generated from CT, and CIRM. The cartilage-reproducing image reconstruction method has compensated the cartilage profile based on the distance between the subchondral surfaces of the radial head and surrounding bones in CT images. The models of actual radial head geometry used as the gold standard was generated from CT arthrography (CTA). All models of each specimen were matched by registering the surface area of radial neck along with the tuberosity. The difference of head diameter, head thickness, and articular disc depth among three models was evaluated and analyzed by Friedman ANOVA and multiple comparison test using Bonferroni method for statistical correction. A p-value of less than 0.01 was considered statistically  significant. The difference of overall 3D geometry was measured with the root mean square of adjacent point pairs.

Results

The analysis displayed the difference of diameter, thickness, and disc depth across the models (p< 0.01). Pairwise comparisons revealed statistically significant difference of all parameters between CTA models and CT models (p< 0.01) whereas no difference was found between CTA models and CIRM models. The mean difference of overall 3D geometry between CTA models and CT models was 0.51±0.24 mm, and between CTA models and CIRM models was 0.24±0.10 mm.

Conclusions

CIRM demonstrated encouraging results in reestablish the normal anatomy and could be potentially used in production process of 3D printed patient-specific radial head prosthesis.

Overlengthening of the radial column in radial head replacement: a review of the literature and presentation of a classification system

BACKGROUND

Radial head arthroplasty is a common procedure in elbow surgery. It has been shown to be of benefit for the patients, but there also are relevant complications that should be prevented if possible. One significant complication is overlengthening of the radial head prosthesis. In overlengthening, the head of the prosthesis overextends the physiological level of the native radial head and leads to overcompression in the radiohumeral joint. Rapid erosion and arthritic changes may then impede the clinical outcome. The incidence of overlengthening is not precisely known, but estimations range to up to 20% of all implanted prostheses.

METHODS

The present review discusses the available body of literature on overlengthening and lines out a classification system that may be used to guide treatment algorithms. The classification is based on the personal experiences of the author during their clinical practice.

RESULTS

In low-grade overlengthening (type I) conservative treatment can be an option. In Types II-IV usually revision surgery is needed. Depending on the state of the capitulum and joint stability, it is possible re-implant a prosthesis, or rely on implant removal alone.

DISCUSSION

The present review aimed at shedding light into overlengthening as a complication radial head replacement and to help identify and treat it.

A Monteggia variant associated with unusual fracture of radial head in a young child: A case report

•

Monteggia fracture is rare among children and its treatment may be challenging.

•

Early recognition of unusual Monteggia variant patterns is crucial to avoid delay in treatment.

•

Adherence to the principles of surgical management in unstable variants is encouraged.

Introduction

Monteggia fracture and its variants are not common among children but may be challenging and lead to serious complications if not treated in acute stage. The different types of associated growth plate fractures of proximal radius are not yet clearly defined in any variant classifications.

Presentation of case

A 6-year-old girl was brought to the emergency room after a fall on the left elbow. The plain radiographs showed unstable fracture of proximal ulna with a laterally displaced and comminuted radial head fracture. The patient was treated surgically as a case of a Monteggia variant. The case has been re-evaluated twenty months following the surgery and did not show any radiological signs of growth disturbance nor residual deformity.

Discussion

The presented Monteggia variant is rare in terms of associated unique intra-articular fracture of proximal radius. The successful management of the case is based on adhering to the principles of treatment of Monteggia fractures.

Conclusion

Early recognition of unusual Monteggia variant patterns is crucial to avoid delay in treatment. Adherence to the principles of surgical management in unstable variants is encouraged.

Surgical treatment of the radial head is crucial for the outcome in terrible triad injuries of the elbow

AIMS

To evaluate the outcomes of terrible triad injuries (TTIs) in mid-term follow-up and determine whether surgical treatment of the radial head influences clinical and radiological outcomes.

METHODS

Follow-up assessment of 88 patients with TTI (48 women, 40 men; mean age 57 years (18 to 82)) was performed after a mean of 4.5 years (2.0 to 9.4). The Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), and Disabilities of the Arm, Shoulder and Hand (DASH) score were evaluated. Radiographs of all patients were analyzed. Fracture types included 13 Mason type I, 16 type II, and 59 type III. Surgical treatment consisted of open reduction and internal fixation (ORIF) in all type II and reconstructable type III fractures, while radial head arthroplasty (RHA) was performed if reconstruction was not possible.

RESULTS

At follow-up the mean MEPS was 87.1 (20 to 100); mean OES, 36.9 (6 to 48); and mean DASH score, 18.6 (0 to 90). Mean movement was 118° (30° to 150°) for extension to flexion and 162° (90° to 180°) for pronation to supination. The overall reoperation rate was 24%, with nine ORIF, ten RHA, and two patients without treatment to the radial head needing surgical revision. When treated with RHA, Mason type III fractures exhibited significantly inferior outcomes. Suboptimal results were also identified in patients with degenerative or heterotopic changes on their latest radiograph. In contrast, more favourable outcomes were detected in patients with successful radial head reconstruction after Mason type III fractures.

CONCLUSION

Using a standardized protocol, sufficient elbow stability and good outcomes can be achieved in most TTIs. Although some bias in treatment allocation, with more severe injuries assigned to RHA, cannot be completely omitted, treatment of radial head fractures may have an independent effect on outcome, as patients subjected to RHA showed significantly inferior results compared to those subjected to reconstruction, in terms of elbow function, incidence of arthrosis, and postoperative complications. As RHA showed no apparent advantage in Mason type III injuries between the two treatment groups, we recommend reconstruction, providing stable fixation can be achieved. Cite this article: Bone Joint J 2020;102-B(12):1620-1628.

Elbow Fracture-Dislocations: Determining Treatment Strategies

Elbow dislocations represent common injuries. A quarter of these injuries involve at least 1 fracture. The sequel of elbow fracture-dislocations can be fraught with complications, including recurrent instability, posttraumatic arthritis, elbow contracture, and poor functional results. The 3 main patterns of injury are valgus posterolateral rotatory instability, varus posteromedial rotatory instability, and transolecranon fracture-dislocation. This article discusses each pattern individually, including the anatomy, the typical injury pattern, and treatment strategies. It also discusses common complications that can occur.

Management of Monteggia Injuries in the Adult

Monteggia fracture-dislocation of the elbow is a fracture of the proximal ulna with associated dislocation of the radial head or radial neck fracture. In adults, this injury is managed with open reduction and internal fixation of the ulna fracture. Care should be taken to ensure anatomic reduction of the proximal ulna. If radial head dislocation or subluxation persists, reduction of the ulna should be reassessed. Rarely, interposed soft tissue may block radial head reduction, and requires removal. Complications include hardware prominence, stiffness, infection, heterotopic ossification, nerve injury, malunion or nonunion of the ulna, radioulnar synostosis, and persistent radial head instability.

Stabilization of the radial head with the palmaris longus or the gracilis tendon: an anatomical feasibility study

PURPOSE

The proximal radioulnar joint (PRUJ) and the radiocapitellar joint may be destabilized after trauma. Different techniques for stabilization of PRUJ have been proposed, but none of them can stabilize the radiocapitellar joint at the same time. We propose a ligamentoplasty to stabilize the radial head at these two joints by reconstructing the radial head annular ligament and the lateral collateral ulnar ligament (LCUL) with a single graft (palmaris longus or gracilis tendon of the knee).

METHODS

Fifteen cadaveric upper limbs were used to compare the stabilization obtained by performing our ligamentoplasty with the palmaris longus or the gracilis tendon. For each technique, the stabilization obtained was evaluated by measuring the displacement of the radial head in the anterior, lateral and posterior directions when a force of 1 N was applied in maximum supination, neutral rotation and maximum pronation. We also evaluated whether this technique could damage the ulnar nerve or the posterior interosseous nerve by dissecting them and whether it could limit the range of rotation of the forearm.

RESULTS

Our ligamentoplasty enables to restore PRUJ stability equivalent to the intact ligament condition. The palmaris longus was inconstant (13/15) and too short to allow concomitant reconstruction of the LCUL (except in one case). No nerve damage was found during the dissection, and the range of rotation of the forearm was not limited by the ligamentoplasty. We also report a clinical case with an excellent result and without complications.

CONCLUSION

This ligamentoplasty we have described makes it possible to stabilize the radial head with respect to the radial notch of the ulna and with respect to the capitellum of the humerus. The gracilis tendon is more suitable than the palmaris longus because of its constant presence and length. A clinical series is now necessary to better evaluate this technique.

Positioning of longest axis of the radial head in neutral forearm rotation

INTRODUCTION

The radial head has an ellipsoid shape so that a longest and a shortest axis can be defined. The aim of this study is to evaluate the position of the longest axis of the radial head (LARH) in relation to proximal radioulnar joint (PRUJ) and to the forearm in neutral position using 3D computed tomography (CT).

MATERIALS AND METHODS

3D CT reconstructions of the distal humerus, the radius and the ulna of 27 healthy volunteers (average age 27.65 ± 9.25; 24 males, 3 females) were created. First an evaluation of the elliptic form of the radial head and the location of its longest axis was performed. Next, three planes were defined: the PRUJ plane, the forearm plane and a neutral plane. Based on the angle between the forearm plane and the neutral plane, the rotation of the scanned forearm was measured. Taking this rotation into account, the position of the LARH compared to PRUJ plane and forearm plane in neutral position is recalculated.

RESULTS

The shape of the radial head is determined to be non-circular based on this study population (p < .001). In neutral position, the angle between the LARH and the forearm plane is 5.28° (SD: 15.09) and between the LARH and the PRUJ is 33.46° (SD: 13.91).

CONCLUSIONS

The position of the LARH is found to be approximately perpendicular to the forearm plane when the forearm is in neutral position and perpendicular to the PRUJ plane when the forearm is on average in 30° of pronation.

Results of radial head resection after Mason type 3 or 4 fracture of the elbow

Background

Resection of the radial head is a surgical indication for comminuted radial head fracture in which internal fixation is inaccessible. Some complications from the surgery can alter the function of the patient's elbow. The objective of this study was to assess functional outcome of the elbow after resection of the radial head.

Methods

A retrospective longitudinal study was performed with patients who underwent radial head resection between 2008 and 2018. Elbow function was assessed by the Mayo Elbow Performance Index (MEPI) for 11 patients comprising three women and eight men. The mean follow-up was 47.6 months. The mean age was 41±10.3 years.

Results

Nine patients had a stable and painless elbow. The mean extension-flexion arc was 97.73°±16.03°. The mean values of pronation and supination were 76.8° and 74.5°, respectively. The mean MEPI score was 83.2 points, and restoration of overall function was achieved in 81% of the cases. Poor function was noted in one in 10 that presented with a terrible triad.

Conclusions

Resection of the radial head restored elbow functionality at a rate of 81%, which was a good outcome for patients.

Fracture Pattern Influences Radial Head Replacement Size Determination Among Experienced Elbow Surgeons

BACKGROUND

Correct sizing is challenging in radial head replacement and no consensus exists on the implant's optimal height and width to avoid elbow stiffness and instability. Studies exists, suggesting how to appropriately choose the implant size, but the manner by which the fracture pattern influences the surgeons' operative choices was not investigated.

METHODS

The radial heads of four fresh-frozen cadaveric specimens were excised, measured, and fractured to simulate four patterns: three fragments (A); four fragments (B); comminuted (C); comminuted with bone loss (D). Nine examiners were asked to indicate first the maximum diameter of the radial heads with the help of dedicated sizing dishes and then the appropriate implant size with trial implants. Accuracy and precision were determined. A coefficient of variation was calculated and agreement was evaluated with the Bland-Altman method.

RESULTS

Accuracy and precision of radial head diameter estimation with dedicated sizing dish were 96.73% and 93.64%, (best pattern, D; worst, C). Accuracy and precision of radial head diameter estimation with trial implants were 99.71% and 90.66% (best pattern, A; worst, D). Frequent modifications occurred between the initial radial head size proposal based on the sizing dish and the radial head size chosen after use of the trial implants (47.2%).

CONCLUSIONS

Diameter estimation of radial heads with dedicated sizing dishes may be underestimated in comminuted fractures; when bone loss is present, this may lead to an overestimation, especially when using trial implants. Care is essential to determine the optimal size of the implant and to avoid overlenghtening and oversizing, which can be responsible for implant failure.

LEVEL OF EVIDENCE

Basic Science Study.

CLINICAL RELEVANCE

Knowledge of the manner by which the fracture pattern influences radial head replacement size estimation can help preventing overlenghtening and oversizing during this procedure.

Acute radial head replacement with bipolar prostheses: midterm results

In irreparable radial head fractures, especially if primary stabilizers of the elbow are damaged, the prosthetic replacement prevents instability and stiffness. Concerns have arisen over the use of bipolar press-fit prostheses due to the frequent finding of osteolysis and the risk of instability if compared to monopolar implants. Our aim was to assess midterm clinical and radiological outcomes of bipolar implants and the influence of osteolysis on proximal pain. Seventeen patients with irreparable fractures of the radial head, treated in acute with the same prosthetic model (rHEAD recon SBI/Stryker) between January 2015 and December 2018, were enrolled. Clinical assessment was performed using MEPS and DASH scores; a radiographic study was done to identify heterotopic ossifications and periprosthetic osteolysis. Outcomes at the last follow-up, according to MEPS, were excellent in 10 cases, good in 5 and fair in 2; none of the patients had severe pain or instability. In 3 cases, it was necessary to remove the implant, mainly because of early loosening. Radiological findings of osteolysis were detected in 9 cases, but no statistical correlation was found with MEPS and proximal pain. The use of bipolar implants is reliable if an accurate repair of ligament tears is performed and provides a good stability. Nevertheless, the risk of early aseptic loosening in uncemented implants is not negligible, and the follow-up of the patient must be strict. Late osteolysis does not seem to have clinical relevance, but further prospective studies are necessary to clarify this topic.

Mid-term outcomes of surgical management of complex, isolated radial head fractures: a multicentre collaboration

OBJECTIVES

The available literature discussing optimal surgical management of Mason II and III radial head (RH) fractures without concomitant bone or ligamentous injuries is limited. We aim to help determine the appropriate management of these functionally significant injuries.

DESIGN

We present our retrospective cohort study of outcomes of surgically managed isolated, displaced RH fractures SETTING: Study from three trauma centres.

PATIENTS/PARTICIPANTS

Adults who underwent surgical treatment for isolated displaced RH fractures.

INTERVENTION

RH open reduction internal fixation (ORIF), replacement or excision MAIN OUTCOME MEASUREMENTS: Elbow range of motion (ROM), pain and function using Oxford Elbow Score (OES), Mayo Elbow Performance Score (MEPS), Patient-Rated Elbow Evaluation (PREE) and QuickDASH (QD).

RESULTS

Of 46 patients included (mean age 47 years and mean follow-up 48 months), 12 type II fractures were treated with ORIF and 34 type III injuries had ORIF (16), replacement (12) or resection (6). ROM was comparable in all groups, with mean arcs of flexion-extension of 131° and pronation-supination of 147°. Mean visual analogue score for pain was 1.3 in those treated with ORIF compared to 1.9 with arthroplasty and 2.5 with excision. Mean functional scores were 41, 92, 14 and 14 for OES, MEPS, PREE and QD, respectively. Complication rates were 39% for ORIF, 33% for arthroplasty and 33% for resection. Overall re-operation rate was 13%.

CONCLUSIONS

Functional outcome is similar in all groups of surgically treated patients with isolated, displaced RH fractures. Complication rates are higher than that reported previously in the literature but with low re-operation rates.

LEVEL OF EVIDENCE

IV.

Using either Evolve® or MoPyC® radial head prosthesis in the treatment of comminuted radial head fractures

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

Radial Head Fixation vs Replacement in Terrible Triad: Preliminary Results of a Prospective Cohort Study with Patient Reported Outcome

INTRODUCTION

The combination of posterior elbow dislocation, radial head fracture, and coronoid fracture has been named "terrible triad" as this injury is difficult to treat and yield poor outcomes. Some studies compared the results of radial head fixation to replacement in isolated radial head fractures, very few reports have tried to compare both treatment modalities in the setting of a terrible triad injury.The aim of this study was to compare the functional outcome of radial head fixation vs replacement in terrible triad injuries of the elbow.

METHODS

A single-center, prospective cohort study was conducted at an academic Level 1 Trauma Center from April 2016 to April 2019.A total of 30 patients with terrible triad injury of the elbow were enrolled. The primary outcome was the Quick Disability of Arm, Shoulder and Hand (Quick-DASH) at 1 year. The secondary outcomes were to report the Mayo Elbow Performance Score (MEPS) at 1 year and elbow range of motion.

RESULTS

At final follow up for each patient (13.4 ± 1.2 months) The Quick-DASH score at 1 year for fixation group was 5 ± 2.3, for the replacement group it was 7.1 ± 7.1. The MEPS at 1 year for fixation group was 93.6 ± 8.4, for the replacement group it was 90.9 ± 9.4.Loss of elbow extension at 1 year for fixation group was 17.1° ± 10.7°, for replacement group it was 18.75° ± 11.5°.

CONCLUSION

A systematic approach to address the bony and soft tissue components of terrible triad elbow injury is crucial to obtain satisfactory outcome. Our study shows that radial head repair and replacement, in the setting of terrible triad injury, yields comparable results.

LEVEL OF EVIDENCE

Level II, Therapeutic study.

Presentation and Management of Displaced Lateral Condylar Mass Fractures With Ipsilateral Displaced Olecranon Fractures in Two Pediatric Cases

CASES

Two pediatric patients, aged 4 and 6-years-old, presented to a level one children's hospital with displaced lateral condylar mass (LCM) and ipsilateral displaced olecranon fractures after falling directly on to the affected extremity. Both patients underwent surgical fixation of the fractures, one of whom was found to have a laterally dislocated radial head intra-operatively. While one of the patients underwent open reduction internal fixation (ORIF) of both the LCM and olecranon fractures, the other patient underwent ORIF of the LCM and closed reduction percutaneous pinning (CRPP) of the olecranon fracture.

CONCLUSIONS

Both patients were treated immediately upon presentation. They went on to full recovery with well-healed fractures and return of function to the affected extremity. Appropriate surgical management with ORIF versus CRPP may depend on displacement of the fractures and/or involvement of the radial head. Due to the rarity of this fracture combination, it can be difficult to identify in the acute setting. Most complications arise when the LCM-olecranon fractures go untreated. Therefore, it is imperative to have a high suspicion for multiple injuries at the elbow when a pediatric patient presents with elbow pain and swelling after a fall.

The effect of stem fit on the radiocapitellar contact mechanics of a metallic axisymmetric radial head hemiarthroplasty: is loose fit better than rigidly fixed?

BACKGROUND

Radial head hemiarthroplasty is commonly used to manage comminuted displaced fractures. Regarding implant fixation, current designs vary, with some prostheses aiming to achieve a tight "fixed" fit and others using a smooth stem with an over-reamed "loose" fit. The purpose of this study was to evaluate the effect of radial head hemiarthroplasty stem fit on radiocapitellar contact using a finite element model that simulated both fixed (size-for-size) and loose (1-, 2-, and 3-mm over-reamed) stem fits. It was hypothesized that a loose stem fit would improve radiocapitellar contact mechanics, with an increased contact area and decreased contact stress, by allowing the implant to find its "optimal" position with respect to the capitellum.

METHODS

Finite element models of the elbow were produced to compare the effects of stem fit on radiocapitellar contact of a metallic axisymmetric radial head implant. Radiocapitellar contact mechanics (contact area and maximum contact stress) were computed for 0°, 45°, 90°, and 135° of elbow flexion with the forearm in neutral rotation, pronation, and supination.

RESULTS

The data suggest that the loose smooth stem radial head implant may be functioning like a bipolar implant in optimizing radiocapitellar contact. Over-reaming of 3 mm produced a larger amount of stress concentration on the capitellum, suggesting there may be a limit to how loose a smooth stem implant should be implanted.

CONCLUSIONS

The loose 1 to 2 mm over-reamed stem provided optimal contact mechanics of the metallic axisymmetric radial head implant compared with the fixed stem.