The effect of radial head excision and arthroplasty on elbow kinematics and stability

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

PURPOSE

To report preliminary clinical results and safety of 3D-printed patient-specific titanium radial head (RH) prosthesis in treatment of the irreparable RH fractures.

MATERIAL AND METHODS

This multi-centric prospective study included 10 patients (6 men and four women, mean age 41 years (range, 25-64 years)). Three cases were classified as Mason type III and 7 cases as type IV. Patients were assessed preoperatively, intraoperatively, and at 1, 6, 12, 24, 36, and 48 weeks postoperatively. Range of motion (ROM), visual analog scale (VAS) score, Disabilities of the Arm, Shoulder and Hand (DASH) score, Mayo Elbow Performance Score (MEPS), radiology imaging, and laboratory blood and urine testing were evaluated.

RESULTS

The prostheses were implanted utilizing cemented stems in 5 patients and cementless stems in 5 patients. Intraoperatively, well congruency of a prosthesis with capitellum and radial notch of ulna was observed in all cases. All patients had improvement of ROM, VAS score, DASH score, and MEPS during the postoperative follow-ups. At the final follow-up, mean elbow extension was 6.5° (range, 0°-30°), flexion 145° (range, 125°-150°), supination 79° (range, 70°-80°), and pronation 73.5° (range, 45°-80°). Mean VAS score was 0.3 (range, 0-3), DASH score was 12.35 (range, 1.7-23.3), and MEPS was 99.5 (range, 95-100). Postoperative radiographs demonstrated heterotopic ossification in 2 cases, periprosthetic radiolucency in 2 cases, and proximal radial neck resorption in 2 cases. No one had the evidence of capitellar erosion, implant failure, malpositioning, overstuffing, or symptomatic stem loosening. There was no significant alteration of laboratory results or adverse events related to the 3D-printed prosthesis implantation.

CONCLUSION

The preliminary results demonstrated that implantation of the 3D-printed patient-specific titanium RH prosthesis is safe and may be a potential treatment option for irreparable RH fracture.

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.

Ulnohumeral joint static cartilage compression is affected by radial head implant size

INTRODUCTION

Radiocapitellar joint arthroplasty is a commonly performed procedure, which often leads to early failure or instability. Few studies assess the effect of radiocapitellar joint arthroplasty on the ulnohumeral joint. We hypothesized that static forces of contact (compressing cartilage, or cartilage relaxation contact force) would reveal the effect of varying radial head implant size and elbow position on the ulnohumeral joint.

METHODS

A minimally-invasive method of measuring cartilage relaxation contact force was utilized in 10 fresh-frozen human cadaveric specimens that did not require significant dissection or intraarticular sensor placement. Specimens were rigidly fixed in various positions of elbow flexion and forearm pronosupination with increasing radial head implant lengths. Uniaxial distracting forces were applied and displacement was repeatedly measured with resultant best-fit polynomial curves to determine inflections corresponding to the force required to overcome static cartilage relaxation as in previous work.

FINDINGS

Baseline mean (intra-cadaver) cartilage relaxation contact force was 11.8 N (standard error of the mean = 0.3) at 90° of elbow flexion and neutral rotation. There was little variation within specimens (Intraclass correlation coefficient > 0.94). Cartilage relaxation contact force increased at the ulnohumeral joint with radial head implant overstuffing (> 4 mm, P < 0.05) and elbow flexion (120°, P < 0.001). Pronosupination altered cartilage relaxation contact force in an implant-length independent manner (P < 0.05).

INTERPRETATION

Radiocapitellar joint arthroplasty implant length and elbow joint position independently contribute to increased cartilage relaxation contact force at the ulnohumeral joint. This further supports attempts at anatomic reconstruction of the radiocapitellar joint to prevent pathologic ulnohumeral joint loading.

Silicone radial head prostheses revisited: do they have a role in today's practice? A systematic review of literature on clinical outcomes

BACKGROUND

Silicone radial head prostheses (SRHP) are considered obsolete due to reports of frequent failure and destructive silicone-induced synovitis. Considering the good outcomes of modern non-radial silicone joint implants, the extent of scientific evidence for this negative view is unclear. The aim of this research was to systematically analyze the clinical evidence on complications and outcomes of SRHP and how SRHP compare to both non-SRHP and silicone prostheses of other joints.

METHODS

A systematic literature review was conducted through the Cochrane, PubMed, and Embase databases.

RESULTS

Eight cohort studies were included, consisting of 142 patients and follow-up periods ranging from 23 months to 8 years. Average patient satisfaction was 86%, range of 71%-100%, and 58 complications were seen, but no cases of synovitis. These outcomes were in line with non-SRHP. Four case series with 11 cases of synovitis were found, all due to implant fractures years to decades after implantation. Six systematic reviews of currently used non-radial silicone joint implants showed excellent outcomes with low complication rates.

CONCLUSIONS

Since SRHP have satisfactory clinical results and an acceptable complication rate when selecting a patient group in suitable condition for surgical indications, it is considered that SRHP can still be chosen as a potential surgical treatment method in current clinical practice.

Does Proximal Hamate Graft for Proximal Scaphoid Reconstruction Restore Native Wrist Kinematics?

BACKGROUND

The objective of this study was to determine whether reconstruction of the proximal pole of the scaphoid with a proximal hamate graft restores native carpal kinematics.

METHODS

A cadaveric study was designed assessing wrist kinematic after proximal hamate graft for proximal pole of the scaphoid nonunion. Wireless sensors were mounted to the carpus using a custom pin and suture anchor system to 8 cadavers. A wrist simulator was used to move the wrist through a cyclical motion about the flexion/extension and radial/ulnar deviation axes. Each specimen was tested under a series of 3 conditions: (1) a native state, "Intact"; (2) fractured scaphoid proximal pole, "Fracture"; and (3) post-reconstruction of the proximal pole of the scaphoid using a proximal hamate graft, "Graft."

RESULTS

The fracture condition resulted in a statistically significant change in scapholunate kinematics across the entire arc of motion relative to the intact condition. Reconstruction with proximal hamate grafts restored scapholunate kinematics close to the intact state in both flexion/extension and radial/ulnar deviation axes. The lunocapitate flexion during wrist flexion was significantly different after the hamate graft reconstruction.

CONCLUSIONS

Proximal hamate to scaphoid transfer resulted in restoration of near normal carpal kinematics to the intact state.

Anatomic Monopolar Press-fit Radial Head Arthroplasty; High Rate of Loosening at Mid-Term Follow Up

Introduction

Radial head arthroplasty (RHA) is used for the management of unstable or unreconstructable injuries of the radial head. Our aim was to investigate clinical and radiographic outcomes in patients treated with the Acumed anatomic radial head press-fit system for trauma.

Methods

Clinical and radiographic assessment of RHAs undertaken for trauma with minimum 2-year follow-up.

Results

16 consecutive patients, mean age 53 (21-82) and 66 month ± 27 (26-122) clinical follow-up were included. There were marked radiographic changes with 11/16 showing periprosthetic lucent lines and 13/16 showing subcollar osteolysis. Radiographic changes occurred early post-surgery. Stem loosening was associated with larger cantilever quotients (0.47 vs 0.38, p  =  0.004). Overall survivability was 81.2%, with 3 RHAs removed. Clinical outcomes for the retained RHAs were acceptable with mean flexion 134°, extension deficit of 10°, pronation of 82°, and supination of 73°. Mean VAS scores were 8.5 ±  14.4, QuickDASH 13.8 ±  18.9, Mayo Elbow Performance Scores were 91.5 ±  12.5 with no poor scores.

Conclusion

Mid-term clinical functional outcomes following the Acumed anatomic RHA are acceptable in most cases. However, in view of the extensive periprosthetic lucencies and surgical removal due to loosening, patients should be cautioned when consented for implantation of the prosthesis, especially if a large collar is anticipated.

Impact of radiocapitellar interposition arthroplasty on ulnohumeral joint biomechanics

BACKGROUND

Radial head excision (RHE) has been shown to increase contact pressures within the ulnohumeral joint. Radiocapitellar interposition arthroplasty (RCIA) with the use of a soft tissue graft is an alternative for the treatment of isolated radiocapitellar arthritis or with failure of radial head replacement. We investigated contact pressures and contact area within the ulnohumeral joint after RHE compared to RCIA with dermal autograft.

METHODS

Six fresh-frozen cadaver elbows were tested on a custom dynamic elbow frame. A pressure sensor was inserted into the intact elbow joint, and mean contact pressure, peak contact pressure, contact area, and force within the ulnohumeral joint were recorded at 0°, 30°, 60°, 90°, and 120° of flexion as a valgus load was applied to the elbow. The radial head was then excised and specimens were retested. Finally, a dermal graft matched to the size of the resected radial head was inserted in the radiocapitellar space and the specimens were tested a third time.

RESULTS

At 90° of flexion, contact pressure within the ulnohumeral joint was significantly lower with RCIA compared with RHE (110.8 kPa vs 216.8 kPa; P = .013). The mean peak contact pressure was also significantly lower with RCIA compared with RHE at 90° (279.4 vs 626.7 kPa; P = .025). No statistically significant differences were seen in mean contact area or force between the 3 testing conditions at any flexion position.

CONCLUSION

RCIA with a dermal graft reduced contact pressures within the ulnohumeral joint compared to RHE at 90° of flexion without a significant change in contact area or contact force.

Clinical study of suture anchors in the treatment of radial head fractures

BACKGROUND

This study aimed to analyze and study the clinical effect of suture anchors in the treatment of radial head fractures (RHFs).

METHODS

A total of 11 patients (five male and six female) with RHFs who were treated from March 2016 to June 2021 were included in this study. They were 17-61 (average 38.5) years old. In terms of the Johnston-Mason classification, two cases were type II, seven cases were type III, and two cases were type IV. All patients were treated with open reduction and anchor internal fixation.

RESULTS

All 11 patients were followed up, all incisions healed by first intention, and the duration of follow-up was 14-20 months. The average operation time was 40 ± 15 min. The clinical healing time was 4-6 (average 5) weeks. No patients had any complications, such as traumatic arthritis, malunion, nerve injury, joint stiffness, or incision infection. The clinical effects were evaluated according to the Mayo Elbow Performance Score. The scores of all 11 cases were 90-95, all excellent.

CONCLUSION

The application of suture anchor internal fixation in the treatment of RHFs has the advantages of accurate reduction, no need for a secondary operation to remove the fixation materials, less trauma, fewer complications, good fracture healing, and good recovery of elbow extension, flexion, and rotation functions.

Revision of Failed Radial Head Arthroplasty

BACKGROUND

Revision of radial head arthroplasty (RHA) may be indicated in cases of prosthesis loosening and malposition. Inherent difficulties in revision surgery include poor bone stock and disrupted soft tissue envelope. Although cases of RHA used for revision of failed RHA are rare, there is reasonable expectation for increasing frequency of these cases due to the increasing incidence of primary RHA. Furthermore, there is an increasing demand for postoperative recovery of function; thus, surgeons may consider revising a failed RHA to a new RHA. We report on series of failed RHA which were revised to a new radial head prosthesis.

METHODS

A retrospective review was performed at multiple institutions for a single radial head prosthesis used for revision of a failed radial head prosthesis. Clinical and radiographic outcomes were collected with a minimum of 1 year of follow-up.

RESULTS

Across 11 patients at a mean follow-up of 45.1 months, the mean Mayo Elbow Performance Score was 81.7; mean Disabilities of the Arm, Shoulder, and Hand scores were 24.4; and mean Visual Analog Scale for pain was 0.6. Radiographic analysis yielded no evidence of capitellar wear or stem loosening.

CONCLUSION

A radial head prosthesis can produce satisfactory results when used for revision of a failed prosthesis. Inherent difficulties in revision surgery include the potential for reduced bone stock and a disrupted soft tissue envelope. Elements of prosthesis design which may contribute to effectively managing revision surgery include a long stem with in-growth surface and prosthetic head alignment to the axis of forearm rotation.

The comparative performance of radial head prostheses in patients younger than and older than 50 years: a systematic review

Background

Patient age may play a role in the surgeon's decision between radial head arthroplasty (RHA) and open reduction internal fixation in radial head fracture treatment. Though large sample reports have detailed outcomes of radial head replacement for a mean age younger than 50 years, the age ranges are widely distributed. Patient outcomes are not uniform across a broad age distribution. Therefore, treatment decisions should be evaluated within the confines of a narrower age bracket. An understanding of clinical outcomes for radial head replacement in younger adults will provide value for guiding treatment decisions. We performed a systematic review comparing the clinical outcomes for radial head replacement in patients younger and older than 50 years of age. Further analysis compared outcomes between RHA performed as a primary procedure and as a secondary procedure in patients younger and older than 50 years of age.

Methods

PubMed was queried for articles which delineated individual patient data for age, surgical treatment, and appropriate outcome metrics. Articles were grouped based on patient age of under 50 and over 50 years and within those age groups, based on the arthroplasty being performed as a primary or as a secondary procedure.

Results

There were no significant differences between the under 50 and the over 50 groups for Mayo Elbow Performance Score (P = .79) and for implant revision/removal (P = .32). In the under 50 group, RHA done as a primary procedure had significantly higher (P = .001) mean Mayo Elbow Performance Score than RHA done as a secondary procedure. In the over 50 group, relative risk was 2.39 (95% confidence interval, 2.12-2.69) for implant revision/removal (P = .11) when comparing primary and secondary procedures.

Discussion

At a mean follow-up of 48 months, RHA in patients under the age of 50 years had satisfactory outcomes which were comparable to outcomes in patients over the age of 50 years. Across both age groups, arthroplasty performed as a primary procedure demonstrated superior outcomes compared to arthroplasty performed as a secondary procedure. Our findings provide guidance to surgeons who face a multifaceted decision when encountering younger adult patients with radial head fracture patterns that may not be amenable to fixation. Awareness of the age-specific performance of radial head implants is an important component of the decision for surgical treatment.

Clinical Results of Surgical Treatment for Comminuted Radial Head and Neck Fracture: Headless Compression Screws Versus Plate Fixation

Background

We surgically treated comminuted radial head and neck fractures using headless compression screws, including multiple screws for the radial head and a single oblique screw for the radial neck. This study aimed to compare the clinical and radiological results for comminuted radial head and neck fractures between surgery using headless compression screws with a single oblique screw for the radial neck, our new procedure, and a plate system precontoured to the proximal radius.

Methods

This retrospective study included 23 patients (11 and 12 in the screw and plate groups, respectively). The fractures were type 3 according to the Mason-Johnston classification modified by Broberg and Morrey. Clinical outcomes analyzed included the motion range of the elbow and forearm, Mayo Elbow Performance Score, and radiological assessments. In addition, postoperative complications were also investigated. The average follow-up was 18 months.

Results

The bone union was achieved in all the patients, and there were no significant differences in clinical outcomes and radiological assessments except forearm supination (p = 0.02). Furthermore, additional surgical procedures were performed in one and five patients in the screw and plate groups, respectively (p = 0.16). Posterior nerve palsy was observed in two patients in the plate group. Complications were observed in one and six patients in the screw and plate groups, respectively (p = 0.07).

Conclusion

Both surgical procedures achieved good clinical and radiological outcomes with bone and ligament injury repair. The screw group had a greater range of forearm supination than the plate group.

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

PURPOSE

Comminuted radial head fractures are commonly treated by surgical resection or replacement with a prosthesis. A potential problem with radial head replacement is overlengthening of the radial neck ("overstuffing" of the radial head), which has been shown to affect both ulnohumeral kinematics and radiocapitellar pressures. We hypothesized that an overstuffed radial head prosthesis increases capitellar pressure and reduces coronoid pressure.

METHODS

Seven human cadaveric elbows were prepared on a custom-designed apparatus simulating stabilizing muscle loads, and passively flexed from 0° to 90° under gravity valgus torque while joint contact pressures were measured. Each elbow was tested sequentially with different neck lengths, starting with the intact specimen followed by insertion of understuffed (-2 mm), standard-height (0 mm), and overstuffed (+2 mm) radial head prostheses in neutral forearm rotation, 40° pronation, and 40° supination positions, respectively.

RESULTS

Capitellar mean contact pressures significantly increased after insertion of an overstuffed radial head prosthesis. In valgus position with neutral forearm rotation, capitellar mean contact pressure on the joint with an intact radial head averaged 227 ± 70 kPa. Insertion of understuffed, standard-height, and overstuffed radial head prostheses changed the mean contact pressures to 152 ± 76 kPa, 212 ± 68 kPa, and 491 ± 168 kPa, respectively. The overstuffed radial head group had significantly lower whole coronoid mean contact pressures (153 ± 56 kPa) compared with the intact (390 ± 138 kPa) and standard-height (376 ± 191 kPa) radial head groups.

CONCLUSIONS

An increase in radial prosthesis height significantly increases capitellar contact pressures and reduces coronoid contact pressures.

CLINICAL RELEVANCE

Restoration of the anatomic radial head height is critical when performing radial head arthroplasty to maintain normal joint biomechanics. Elevated capitellar contact pressures can potentially lead to pain and early degenerative changes.

Does stress shielding after radial head arthroplasty affect functional outcomes?

BACKGROUND

Various complications related to the prosthesis, such as implant loosening and stress shielding phenomenon, could develop after prosthetic replacement of the radial head. Stress shielding is known to occur around rigidly fixed implants. The purpose of this study was to evaluate the clinical influence and causative factors of the stress shielding phenomenon after radial head arthroplasty (RHA).

METHODS

Clinical records and radiographs of 56 patients with unreconstructable radial head fractures who received radial head replacement between 2009 and 2019 were reviewed. Exclusion criteria were infection, loosening, and follow-up of less than 24 months. After exclusion, 35 patients were enrolled. Patients were divided into two groups: an anatomical press-fit group (Anatomical Radial Head System; Acumed, Hillsboro, OR, USA) and a round bipolar cemented group (RHS; Tornier, Montbonnot Saint-Martin, France). Stress shielding around the prosthesis was assessed in the serial radiological examination. Clinical results were assessed using Mayo elbow performance score (MEPS), Quick Disabilities of the Arm, Shoulder, and Hand (q-DASH) score, range of motion (flexion-extension arc and pronation-supination arc), and visual analog scale score (VAS). Correlations between stress shielding phenomenon and demographic data and functional results were analyzed.

RESULTS

At an average follow-up of 43.06 (± 14.6) months, 14 (40%) out of 35 fixed stems demonstrated stress shielding. Our results showed that the rate of stress shielding was significantly higher in cases with a bilateral ligament injury and in the anatomical press-fit group (p = 0.028 and p = 0.0091, respectively). However, stress shielding around prostheses did not affect the clinical results (p > 0.05).

CONCLUSION

The stress shielding phenomenon around radial head prosthesis may vary according to prosthetic design and severity of ligament injuries. Stress shielding does not affect the mid-term outcomes in the treatment of acute fractures of the radial head.

LEVEL OF EVIDENCE III

Retrospective Cohort Comparison; Treatment Study.

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.

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.

Does Radial Head Resection Impair Hand and Wrist Function? A Long-Term Follow-Up

OBJECTIVE

To evaluate the long-term outcome in patients after radial head resection surgery for isolated Mason type III radial head fractures.

DESIGN

An observational retrospective case series.

SETTING

A Hand and Upper-Extremity Surgery Unit in a tertiary care center.

PATIENTS

Data were collected from files of patients who were operated between the years 1980 and 2020. Of 352 patients who underwent surgery for radial head fractures, 25 patients were eligible and were enrolled in the study.

INTERVENTION

All participants underwent radial head resection surgery and a follow-up clinical and radiographic evaluation by 2 senior orthopaedic surgeons.

OUTCOME MEASUREMENTS

Objective evaluation included active range of motion of the elbow and wrist joints, ulnohumeral angle, key pinch and grip measurements, and radiographic imaging of elbow and wrist joints. Subjective evaluation included visual analog scale measurements, disability of arm shoulder and hand questionnaire, Mayo wrist score, Michigan hand outcome, and Oxford elbow score.

RESULTS

The mean follow-up was 18 years. Mean elbow range of motion and mean grip strength were lower in the operated hand, as compared to the contralateral hand. Mean proximal radial migration was 1.6 mm. Mean results of visual analog scale, disability of arm shoulder and hand, Mayo wrist score, Michigan hand outcome, and Oxford elbow score indicated good functional outcome and high patient satisfaction.

CONCLUSIONS

In our study population, long-term functional outcomes after radial head resection were encouraging. Thus, this procedure may be considered as a surgical alternative when radial head reconstruction or replacement fails.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.

Correlations Between Radial Head Diameters and Humeral Articular Dimensions: Bilateral MRI Morphometric Analysis on 39 Healthy Subjects

PURPOSE

Choosing the correct size of head component in radial head arthroplasty is often challenging, particularly in comminuted fractures, deformities, and revision surgery. The main aim of this study was to investigate possible correlations between radial head diameters and the morphometric parameters of the articular distal humerus in order to find mathematical equations that may be used to infer radial head dimensions indirectly.

METHODS

We performed bilateral elbow magnetic resonance imaging on 39 healthy young subjects, comprising 19 women and 20 men, with a mean age of 28 years (range, 21-32 years). The following measurements, which included cartilage thickness, were calculated on the axial plane: maximum (Dmax) and minimum (Dmin) radial head diameters, capitellum width, capitellum to lateral trochlear ridge width (CAP-TROCHridge), humeral articular width (HUMwidth), capitellum radius of curvature, and lateral, medial, and total trochlear width. The anteroposterior diameters of the capitellum, trochlear sulci, and lateral and medial trochlear ridges were measured on the sagittal plane.

RESULTS

CAP-TROCHridge and HUMwidth were found to be the parameters most strongly correlated with the radial head diameters. Four mathematical equations that allowed Dmax and Dmin to be calculated with an average residual error less than 1 mm, were obtained. The intraclass coefficient was greater than 0.95 for all the measurements.

CONCLUSIONS

Radial head diameters can be accurately inferred from 2 humeral dimensions by magnetic resonance imaging. The HUMwidth, which is not influenced by cartilage thickness, may be useful for planning with preoperative imaging because it can also be calculated by computed tomography scan, whereas CAP-TROCHridge, which is influenced by cartilage thickness, might be useful for direct intraoperative measurement.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Effect of incremental increase in radial neck height on coronoid and capitellar contact pressures

BACKGROUND

Over-lengthening of the radial neck has been shown to affect ulnohumeral kinematics and has been proposed to affect radiocapitellar pressures. We hypothesized that an incremental increase in radial neck height increases the capitellar contact pressure and reduces the coronoid contact pressure. Knowledge of the effects of over-lengthening is clinically important in preventing pain and degenerative changes due to overstuffing.

METHODS

Six human cadaveric elbows were prepared on a custom-designed apparatus simulating muscle loads and passive flexion from 0° to 90° under gravity valgus torque while measuring joint contact pressures in this biomechanical study. Each elbow was tested sequentially starting with the intact specimen followed by insertion of a radial head prosthesis with 0, +2, and +4 mm of radial neck height, respectively.

RESULTS

Capitellar mean contact pressures significantly increased after insertion of +2 and +4 mm radial head prostheses (p < 0.03). The capitellar mean contact pressure with a 0 mm radial head prosthesis was 97 KPa. Insertion of +2 mm and +4 mm radial heads increased mean contact pressures to 391 KPa (p = 0.001) and 619 KPa (p = 0.001), respectively, with 90° of elbow flexion.

DISCUSSION

Increasing radial prosthesis height by 2 mm significantly increases capitellar contact pressures and reduces coronoid contact pressures.

Evaluation of Four-Dimensional Computed Tomography as a Technique for Quantifying Carpal Motion

Delayed diagnosis of dynamic carpal instability often occurs because early changes in bone alignment and movement are difficult to detect and manifest mainly during a dynamic/functional task. Current diagnostic tools are only able to examine the carpal bones under static or sequential-static conditions. Four-dimensional (three dimensions + time) computed tomography (4DCT) enables quantification of carpal mechanics through 3D volume sequences of the wrist in motion. A comprehensive understanding of carpal mechanics is needed to define normal function and structure and provide targets for treatment of carpal injuries. In this study, measurements of scaphoid translation and joint congruency were taken by creating models from the CT scans of the carpals in extreme frames of motion, registering those models to the neutral position, transforming the models into a local coordinate system, and using software to calculate the joint surface areas (JSA). Results indicated that the centroid of the scaphoid translated 6.4 ± 1.3 mm and extended from extreme radial to extreme ulnar deviation. Results are consistent with the literature. An additional study was performed to measure the responsiveness of the 4DCT technique presented. Bone models from each frame of motion for radio ulnar deviation (RUD) and flexion extension (FE) were created and distinct differences between their JSA were measured qualitatively and quantitatively. The results show that there was statistically significantly different JSA within carpal joints between RUD and FE. These studies provide the first step in developing the methodology when using 4DCT scanning to measure subtle abnormalities in the wrist.

The Radial Floating Cup radial head prosthesis to treat radial head fractures: functional and radiographic results after more than 12 years of mean follow-up

INTRODUCTION

This study was performed to evaluate the long-term clinical and radiographic results of patients presenting with a radial head fracture who were treated surgically with a Judet Radial Floating Cup 2 (RFC 2) radial head prosthesis.

MATERIALS AND METHODS

This was a retrospective, monocentric, observational, multi-operator, and continuous study performed between July 1997 and June 2009 on the treatment of radial head fracture using an RFC 2 radial head prosthesis. The primary efficacy endpoint was the functional status of the operated elbow, evaluated using the Disability of Arm-Shoulder-Hand (Quick-DASH) score and the Mayo Elbow Performance Index (MEPI). The secondary endpoints were mobility and stability of the operated elbow, residual pain and grip strength, nature and rate of complications, as well as possible radiographic abnormalities during follow-up.

RESULTS

Twenty-two patients were treated with the RFC 2 for radial head fractures over the study period. Three (13.6%) were lost to follow-up, including one death. Of the remaining 19 patients, three RFCs had to be removed (15.8%). The final analysis involved 16 patients. The mean follow-up was 144 months (range 109-225 months; standard deviation [SD] = 49.9 months) or 12 years. The average Quick-DASH score was 23.01/100 (range 0-50; SD = 7.8) and three cases were rated as having "excellent" results according to the MEPI (18.7%), nine cases were rated as having "good" results in (56.2%), and four cases were rated as having "average" results (25%). The average mobility values were: 132° of flexion (range 120°-150°; SD = 11), 14.5° of extension deficit (range 0°-40°; SD = 5), 84.4° of pronation (range 20°-90°; SD = 8°), and 67.7° of supination (range 25°-85°; SD = 10). All patients had a stable elbow. The average grip strength on the affected side thus corresponded to 79% (range 44-100%; SD = 8.3%) of the grip strength on the healthy side. Four patients (25%) developed complications: three cases of algodystrophic syndrome (18.7%) and one case of early dislocation (6.2%). Radiographic evaluation revealed that there was a periprosthetic radio-lucencies in eight patients (50%), periarticular ossifications in 12 patients (75%), and lysis of the capitulum in two patients. There was no significant difference in MEPI ratings between patients with and without a periprosthetic radio-lucencies (P = 0.8018).

CONCLUSIONS

Our results indicated that using the RFC 2 prosthesis to surgically treat radial head fractures provides good long-term functional results, including satisfactory mobility and stability.

Optimal Prosthesis Sizing for Radial Head Arthroplasty: A Review of Current Evidence and Guidelines

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Radial head arthroplasty is a viable surgical option when a radial head fracture cannot be reconstructed. Radial head arthroplasty provides a load-bearing articular structure against the capitellum in unstable fractured elbows.

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Studies have emphasized the importance of choosing the correct implant size to replicate the native radial head anatomy, citing various consequences of improperly sized radial head prostheses. Overstuffing of the radiocapitellar joint, or lengthening of the radius, has been extensively studied because of its detrimental effects on elbow biomechanics, but other types of improper sizing also have negative consequences.

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In the setting of severe fracture-dislocation or revision surgery, anatomic landmarks that are useful for prosthesis sizing often are missing. Various methods have been described to provide guidance for the accurate sizing of a prosthetic radial head; a retrieved radial head, the proximal edge of the lesser sigmoid notch, the radiocapitellar synovial fold, and the ulnohumeral joint space all represent useful references.

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Intraoperative radiographic examination is an important step while assessing implant size, including the height of the prosthetic radial head.

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Since no single method is perfect on its own, the surgeon should combine as many reference measures as possible, both before and during the procedure, for accurate prosthesis sizing in order to achieve successful outcomes.

Factors influencing the mid-term radiological and functional outcomes of 41 post-fracture bipolar radial head arthroplasty cases at a mean follow-up of 87 months

INTRODUCTION

When treating comminuted radial head fractures that cannot be adequately fixed, the next option is arthroplasty (radial head replacement). We hypothesized that the radiological and functional outcomes of bipolar mobile cup radial head arthroplasty is not influenced by the length of follow-up but instead by the correct positioning of the implant intraoperatively and by the presence of associated bone or ligament injuries.

PATIENTS AND METHODS

Between May 1998 and December 2016, 82 cases of radial head arthroplasty were performed at our hospital. The mean age of patients at the time of arthroplasty was 53 years (22-81). Ligament or bone injuries complicated the radial head fractures in 70% of patients.

RESULTS

For the final assessment, 41 patients were reviewed and included in the statistical analysis with a mean of 82 months (12-228). The mean MEPS at the final assessment was 88.7 (61-100). There were 23 excellent, 9 good, 9 average and 0 poor results. The average DASH score was 18.7 (0-55). The average VAS for pain was 1.0 (0-5). Five patients (12%) required surgical revision, including one implant change. Our statistical analysis found no relationship between follow-up time and functional outcomes. The appearance of periprosthetic radiolucent lines was not affected by the length of follow-up. Associated bone or ligament injuries significantly increased the probability of periprosthetic radiolucent lines, humeroulnar joint degeneration and decentering of the implanted cup. Radiological evidence of a suspended implant was associated with significantly worse functional outcomes.

CONCLUSION

This study confirms the long-term stability of the clinical outcomes of radial head arthroplasty. There was no relationship between worsening radiological appearance of the implant and the clinical outcomes. It is critical that this implant not be oversized or suspended, as this can trigger premature capitellar erosion and painful stiffness of the operated elbow.

LEVEL OF EVIDENCE

IV; systematic retrospective analysis.

Epidemiology and Treatment of Radial Head Fractures: A Database Analysis of Over 70,000 Inpatient Cases

PURPOSE

We aimed to study the epidemiology of radial head fractures within a single national registry database while analyzing trends in available treatments.

METHODS

A retrospective analysis of data from 2007 to 2016 provided by a national inpatient database registry was performed using the International Classification of Diseases code for radial head fractures and associated German Procedure Classification (OPS) codes. All surgical interventions were evaluated according to fracture type, patient sex and age, and distribution differences over the last decade to detect changes in the treatment trends. The number of major revision procedures was identified and the revision burden for each procedure calculated.

RESULTS

Overall, 70,118 radial head fractures were included, with the annual number rising over 20% during this period. Women were significantly older than men (peak incidence, 55-64 years vs 30-39 years) and more frequently injured (women-to-men, 1.3:1). Surgical interventions increased during the study period, with locking plate fixation of comminuted fractures and radial head arthroplasty (RHA) becoming increasingly performed while radial head resections decreased. The revision burden differed significantly between the fixation techniques, with an increased occurrence of RHA revision procedures more recently.

CONCLUSIONS

The data show a higher number and incidence of surgical procedures, especially for comminuted radial head fractures over the study period. Open reduction and internal fixation remains the most frequently used option, with the use of new fixation devices (eg, locking plates) increasing. The use of RHA more than doubled over the past 10 years while the number of radial head resections decreased.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Reoperation Rates and Costs of Radial Head Arthroplasty Versus Open Reduction and Internal Fixation of Radial Head and Neck Fractures: A Retrospective Database Study

Background: We conducted a retrospective study to compare reoperation/conversion rates and costs between open reduction and internal fixation (ORIF) and radial head arthroplasty (RHA) in patients with radial head/neck fractures. Methods: We examined the Humana Orthopedic data sets using the PearlDiver Application from January 2007 to June 2016 to identify patients with radial head and neck fractures with and without a concurrent elbow dislocation. Time to revision surgery, odds ratios, and survival curves for reoperations/conversions were calculated comparing ORIF and RHA. Results: A total of 7520 patients were identified who had undergone either ORIF or RHA. Overall, ORIF patients were less likely to undergo a conversion procedure (2.76% vs 7.03%) but more likely to undergo any reoperation (21.36% vs 17.63%) with a higher average cost ($19 688.46 vs $11 626.64). Patients who underwent ORIF without a concurrent elbow dislocation were also less likely to undergo a conversion procedure (2.12% vs 7.24%) but more likely to undergo any reoperation (20.22% vs 16.99%) with a higher average cost ($19 420.21 vs $11 123.61). Patients who underwent ORIF with a concurrent elbow dislocation were more likely to undergo both a conversion procedure (15.86% vs 6.39%) and any reoperation (44.98% vs 19.63%) with a higher average cost per patient ($24 999.62 vs $13 192.00). The average time to reoperation/conversion surgery was less than a year for all patient groups. Conclusions: Overall reoperation rates are high in patients undergoing operative treatment of radial head and neck fractures. RHA is less expensive and has fewer reoperations/conversions in short-term follow-up when compared with ORIF in radial head/neck fracture dislocations of the elbow.

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.

Neurologic complications after surgical management of complex elbow trauma requiring radial head replacement

BACKGROUND

Radial head arthroplasty (RHA) has become a successful procedure for addressing acute unreconstructible radial head fractures that compromise elbow stability in complex elbow trauma. The purpose of this study was to investigate the incidence of and risk factors for the development of neurologic complications after surgical treatment of complex elbow fractures that require an RHA.

METHODS

Sixty-two patients with an unreconstructible radial head fracture and complex elbow instability treated with RHA were included. There were 33 men and 29 women, with a mean age of 54 years (range, 22-87 years). The average follow-up period was 5.2 years (range, 3-16 years). All patients were neurologically intact before surgery. The arthroplasty was implanted through a Kocher approach in 55 cases, whereas a Kaplan approach was used in 7. An uncemented smooth stem arthroplasty (Evolve) was used in 27 patients, and an anatomic ingrowth system (Anatomic Radial Head), in 35. At the time of surgery, 23 patients underwent fixation of a coronoid fracture and 15 underwent plating of the proximal ulna. All patients were clinically examined immediately after surgery and during follow-up to detect any degree of neurologic deficit. Radial and ulnar nerve injuries were classified according to the Hirachi and McGowan classifications, respectively. Functional outcomes were evaluated with the Mayo Elbow Performance Score.

RESULTS

A complete posterior interosseous nerve palsy occurred postoperatively in 2 patients. Hand function had completely recovered in both at 2 months after surgery without sequelae. Nine patients complained of ulnar nerve symptoms (immediately after surgery in 6 and as delayed ulnar neuropathy in 3). Most patients with ulnar nerve deficits had undergone additional surgical procedures to address ulnar fractures. Among patients with ulnar neuropathies, only 3 complained of mild sensory symptoms at the latest follow-up. No significant differences in range of motion and Mayo Elbow Performance Score were found between patients with and without neurologic complications. Associated olecranon or coronoid fixation and a prolonged tourniquet time were identified as risk factors for neurologic complications.

CONCLUSION

This study shows that the incidence of neurologic complications associated with the surgical treatment of complex elbow fractures requiring implantation of a radial head prosthesis may be underestimated in the literature. Inappropriate retraction in the anterior aspect of the radial neck, a prolonged ischemia time, and concomitant coronoid or olecranon fracture fixation represent the main risk factors for the development of this complication. Although the great majority of patients have full recovery of their nerve function, they should be advised on the risk of this stressful complication.

Indications and outcomes of radial head excision: A systematic review

BACKGROUND

Radial head excision has historically been a common surgical procedure for the operative management of radial head fractures and post-traumatic conditions. With recent advances in other surgical techniques, controversy exists regarding its indications. This review evaluates the indications and outcomes of radial head excision in traumatic and non-traumatic elbow pathology.

METHODS

Multiple databases were searched for studies involving radial head excision. Screening and data abstraction were conducted in duplicate. Only studies reporting outcomes for radial head excision were included.

RESULTS

Twenty-seven studies with 774 radial head excision patients were included. The most common indications involved acute excision of comminuted radial head fractures (n = 347) and rheumatoid arthritis (n = 201). Post-operative functional scores after acute excision were reported to be good to excellent. In the chronic setting of rheumatoid disease, radial head excision resulted in improved range of motion, although pain was not effectively relieved.

DISCUSSION

Outcomes of radial head excision for acute fracture are good to excellent; however, it should not be performed when concurrent or ligamentous injuries are present. Although some studies compared excision to open reduction and internal fixation or replacement, more data are needed to make proper conclusions. The strength of these conclusions is limited by the quality of included literature.

Elbow Biomechanics: Bony and Dynamic Stabilizers

The elbow positions the hand in a stable manner relative to the trunk while allowing flexion and extension as well as forearm rotation at varying shoulder positions. Its ability to perform this task without joint subluxation is accomplished through a combination of bony congruency, ligamentous restraint, and dynamic stabilization. This article reviews the bony and dynamic contributors to elbow stability and kinematics. Bony stability is conferred through the morphology of the humeroulnar, humeroradial, and radioulnar joints. Depending on the arm position relative to the trunk and the degree of elbow flexion, the bony contribution will vary. Dynamic elbow stabilizers confer stability through the activation of various muscles that cross the elbow. These forces help resist valgus and varus forces and may also increase bony stability by generating compressive forces. The goal of this article is to review the literature surrounding the biomechanics of bony and dynamic stabilizers of the elbow while drawing clinically relevant biomechanical observations.

Reliability of dynamic fluoroscopy for medial elbow stability in the presence of radial head resection

Background

The aim of this study was to examine whether dynamic fluoroscopy is reliable for assessment of medial elbow stability in the presence of radial head resection and different stages of medial collateral ligament (MCL) dissection in a cadaveric elbow model.

Materials and methods

Six intact elbow specimens were measured for joint angulation while applying valgus stress in four examination conditions (Examiner 1, Examiner 2, 1 Nm, 2 Nm) in four different elbow positions (fully pronated or supinated at 0° of elbow extension and 30° of elbow flexion). The elbow specimens were examined for valgus stress in three stages: (1) intact, (2) after radial head resection, and (3) after subsequent dissection of the complete MCL. Anteroposterior radiographs of the elbow were made at each stage to determine joint angulation. Intraclass correlation coefficients (ICCs) were calculated.

Results

In intact elbows, mean joint angulation ranged from 2.2° ± 2.0 (1 Nm) to 5.2° ± 2.3 (Examiner 1). Radial head resection did not increase joint angulation during valgus stress, regardless of joint position and examination condition (Examiner 1: 5.5°; Examiner 2: 5.0°; 1 Nm: 2.6°, 2 Nm: 3.9°). Additional dissection of the MCL led to significantly higher joint angulation during measurements with the standardized torques (1 Nm: 12.4°; 2 Nm: 23.3°). Very good to excellent ICCs for joint angulation between Examiner 1 and Examiner 2 (0.861 to 0.959) were found.

Conclusion

Dynamic fluoroscopy is a reliable diagnostic tool for determining medial elbow stability in the presence of radial head resection and different stages of MCL dissection.

Open Reduction and Internal Fixation Versus Radial Head Arthroplasty for Mason III Radial Head Fractures: Appraising the Current Literature Evidence

Fractures of the radial head are common and account for one-third of elbow fractures. Management has evolved over the past few decades as have the techniques and implants used to treat them. However, no standardized treatment protocol exists because of the complexity with which these fractures may present. The complex, unstable, displaced, and multi-fragmentary fractures, also known as Mason type III fractures, remain one of the most challenging fractures to treat, especially if associated with other elbow injuries. There are various surgical treatment options available, including open reduction and internal fixation or radial head arthroplasty. The purpose of this study was to systematically review the current literature that assessed open reduction and internal fixation compare to radial head replacement to identify the best surgical treatment protocol for the management of Mason type III radial head fracture. All published clinical trials claiming to evaluate or cited elsewhere as being authoritative regarding the surgical treatment of radial head fractures were identified and evaluated. Studies in foreign languages (not in English) were excluded. Based on two randomized controlled trials, this review showed some weak evidence that arthroplasty results in better functional elbow outcomes and lower complication rates as compared to open reduction and internal fixation. There is a scarcity of good quality comparative studies and multicenter randomized controlled trials should be considered.

Proximal radioulnar translocations in adults: a tertiary centre study

We present three cases of proximal radioulnar translocation in adults. Although rare, it is most commonly seen in paediatric cases. There have been three previously documented cases in adults, all requiring surgery and associated with ulnohumeral dislocations. Two of our cases required operative intervention, whilst one was reduced closed and did not require stabilisation. Furthermore, we have for the first time shown that proximal radioulnar translocations can occur in isolation in adults without an ulnohumeral dislocation. LEVEL OF EVIDENCE: Level IV.

Indications and Clinical Results of Radial Head Replacement: Has Anything Changed?

Radial head fractures are common injuries comprising 1/3 of the fractures about the elbow. As a secondary valgus stabilizer of the elbow, radial head fractures can compromise elbow stability leading to long-term pain, dysfunction, and degenerative change. Furthermore, radial head fractures can be accompanied by associated injuries including ligamentous lesions that can further exacerbate elbow instability, leading to long-term sequelae. As fixation principles and technology have evolved, so has the ability to render surgical treatment for these fractures. In general, minimally displaced and some displaced fractures may be treated nonoperatively with early motion. Fractures with a block to rotation and displaced fragments with 3 or fewer fragments may be treated with open reduction and internal fixation. Comminuted fractures or those with greater than 3 fragments may be successfully treated with radial head replacement. Associated elbow instability will also influence treatment decisions.

Surgical revision of radial head fractures: a multicenter retrospective analysis of 466 cases

BACKGROUND

Radial head fractures lead to persisting disability in a considerable number of cases. This study aimed to investigate their most common revision causes and procedures.

METHODS

This multicenter retrospective study reviewed the cases of 466 adult patients who had undergone surgical revision after operative or nonoperative treatment of a radial head fracture. The initial diagnosis was a Mason type I fracture in 13.0%, Mason type II fracture in 14.6%, Mason type III fracture in 22.8%, Mason type IV fracture in 20.9%, terrible-triad injury in 12.8%, Monteggia-like lesion in 13.1%, and Essex-Lopresti lesion in 2.0%. Initial treatment was nonoperative in 30.2%, open reduction and internal fixation (ORIF) in 44.9%, radial head arthroplasty in 16.6%, radial head resection in 3.7%, sole treatment of concomitant injuries in 2.6%, and fragment excision in 2.0%. Up to 3 revision causes and procedures were recorded per case.

RESULTS

The most common complications were stiffness (67.4%), instability (36.5%), painful osteoarthritis (29.2%), ORIF related (14.8%), nonunion or necrosis (9.2%), radial head arthroplasty related (7.5%), ulnar neuropathy (6.0%), and infection (2.6%). Revision procedures frequently included arthrolysis (42.1%), arthroplasty (24.9%), implant removal (23.6%), ligament repair or reconstruction (23.0%), débridement (14.2%), repeated ORIF (8.2%), and/or radial head resection (7.7%). Mason type I or II fractures were primarily revised because of stiffness and painful osteoarthritis. Complications after Mason type III fractures were predominantly ORIF related. Fracture-dislocations showed a wide range of complications, with instability and stiffness comprising the most common causes of revision.

CONCLUSIONS

The complications of radial head fractures are characteristic to their classification. Knowledge of these findings might guide surgeons in treating these injuries and may help counsel patients accordingly.

Surgical treatment of radial head isolated Mason III fractures

INTRODUCTION

In this retrospective study we have analyzed a consecutive series of patients affected by isolated radial head Mason III fractures and treated with bone resection or prosthesis.

PATIENTS AND METHODS

This study includes 24 patients affected by fractures mentioned above and treated between July 2009 and November 2015. 15 patients (average age 48 y.o.) have been treated with prosthesis. The remaining 9 (average age 573) have been treated with a capitellectomy instead. From a clinical point of view, we have evaluated the patients according to main performance indicators such as range of motion, pain, instability and Mayo Elbow Performance Score as parameters.

RESULTS

We have found similar results in both group, with an average MEPS value of 95 in the prosthesis group and 966 in the radial head resection group. The range of motion was similar too: between 1,3° and 1203° in the first group and between 4,4° and 120° in the second one. No significant complication has detected in any patient.

DISCUSSION

According to most recent literature, it is not precisely defined how to treat isolated Mason III fractures, contrary to what is defined in more complex pattern, in which prosthesis are now evaluated as the best indication. Due to radial head limited contribution to elbow stability, in absence of other bony or ligamentous lesions both capitellectomy and prosthesis can be good treatment in this kind of fracture.

CONCLUSION

According to our experience and to the most recent literature, we recommend prosthesis in patient younger than 50 y.o., high demanding or manual worker, while in other cases we think that radial head resection can be the treatment of choice.

Functional Outcome of Elbow Kinematics in Radial Head Excision Versus Radial Head Replacement: A Comparative Study

BACKGROUND:

Radial head fractures are quite common with incidence 1.5-4% of all adult fractures. The treatment for these fractures depends upon age, type of injury and whether the physics is closed or not.

AIM:

Comparison between radial head excision versus radial head replacement based on mayo elbow scoring in comminuted radial head fractures.

MATERIAL AND METHODS:

We did a prospective comparative study comprising 32 patients between age 22-60 years with Mason type II/III radial head fractures at Sir J.J Group of Hospitals, Mumbai. The patients were randomised using the admission day of the week placing 17 patients in the arthroplasty group and 15 patients in the excision group. The patients were followed up for 18-24 months (average 20 months) postoperatively. Results were analysed by the Mayo’s elbow performance score at 6 months and 18 months and were statistically evaluated by unpaired t-test.

RESULTS:

At 6 months, radial head arthroplasty gave excellent results in 2 patients, good in 5 patients and fair in 8 patients. In excision, there were 5 patients with excellent results at 6 months, 7 with good results and 2 with fair results. At 18 months, of the 17 patients who had undergone head arthroplasty, 2 had excellent results, and the same number had poor results. 7 (46.7%) of the 15 cases who had undergone radial head excision had excellent results. Good results were obtained in 7 cases of each. There was 6 cases (35.3%) of radial head arthroplasty which fell into the fair group. As per Mayo’s score at 6 months follow up, mean and standard deviation (SD) of the scores in arthroplasty was 68.82 and 18.66 respectively & for excision, it was 85.66 and 10.66. At 18 months follow up, it was 75 and 14.89 for arthroplasty & 90.66 and 7.98 for excision. The difference between the results was statistically significant (p < 0.01).

CONCLUSION:

Our study shows that long and short-term results of radial head excision are better as compared to arthroplasty in comminuted radial head fractures based on mayo elbow scoring, particularly for dominant upper limbs.

Comparison of the biomechanics of radial head prostheses with dynamic loading in the radiocapitellar joint

We used eight fresh cadaveric elbows to evaluate the biomechanical characteristics of the native radial head, an anatomic radial head prosthesis, and a non-anatomic radial head prosthesis using a dynamic model. The biceps, brachialis, and triceps were attached to pneumatic actuators loaded to mimic muscle force. The radiocapitellar contact pressure and area were measured in real time, and the associated curves were depicted simultaneously. No significant differences in the contact area or associated curves were found between native radial head and the anatomic radial head prosthesis. The contact pressure and associated curve for the anatomic radial head prosthesis were better than those for the non-anatomic radial head prosthesis. We conclude from this study that the contact pressure and area of the elbow with anatomic radial head prosthesis are similar to those of the native radial head. The anatomic radial head prosthesis appears to be more suitable in clinical use.

Outcome following excision of the radial head in children with open physes for impaired elbow motion

BACKGROUND

Only few reports have described the outcome of pediatric patients following radial head resection. Therefore, the aim of the present study was to assess clinical and radiologic outcome of patients with open physes following resection of the radial head.

MATERIALS AND METHODS

Skeletally immature patients treated with resection of the radial head were included. Range of motion (ROM) of the elbow joint was compared with preoperative values. Grip strength, pronation and supination strength, and carrier angle were compared with the unaffected side. Radiographs were assessed for signs of arthrosis, radial migration, and perifocal ossification. Disabilities of the Arm, Shoulder and Hand and Mayo Elbow Performance scores were obtained.

RESULTS

The study included 7 patients (mean age, 11 years), 5 with post-traumatic and 2 with congenitally impaired elbow joint motion. Mean follow-up was 47 months. Pronation/supination ROM improved significantly (P = .018). Extension/flexion ROM did not improve significantly (P = .122). Although grip strength (P = .027) and pronation strength (P = .028) of the affected side were significantly lower compared with the contralateral side, supination strength did not differ significantly (P = .176). The carrying angle was increased in 3 patients. Significant radial migration occurred (mean, 3 mm; standard deviation [SD], 3 mm; P = .018). Arthrosis was found in 3 patients. The mean Disabilities of the Arm, Shoulder and Hand score was 16.1 (range 8.8-30.8; SD, 10.1) and mean Mayo Elbow Performance Score was 88 (range, 70-100; SD, 12).

CONCLUSIONS

Radial head excision may be considered for selected patients with open physes in cases of severe impairment of pronation/supination. However, sequelae such as radial migration, arthrosis, and elevation of the carrying angle should be expected.

Shoulder and Elbow Fractures in Athletes

PURPOSE OF REVIEW

The purposes of this review are to discuss the management of shoulder and elbow fractures in athletes to optimize the return to sport and to highlight treatment impact on the return to play.

RECENT FINDINGS

Fractures of the shoulder and elbow can have profound implications in an athlete career. Recent technique of fractures management trended toward to preserve soft tissue which is critical for an early recovery in athletic population. Arthroscopy presents a strong interest for the treatment of intra-articular fracture, and minimally invasive approach as developed in humeral shaft fracture can be considered to avoid soft tissue damage. Non-articular, stable, and minimally displaced fractures are mainly treated conservatively. However, we encourage a more aggressive approach in shoulder and elbow injuries in the athletes including minimally invasive and stable fixation to preserve vascularity and muscle environment.

WITHDRAWN: Surgical treatment of radial head isolated Mason III fractures

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Injury, 50(2) 2019 382–385, https://doi.org/https://doi.org/10.1016/j.injury.2018.11.044. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

The effect of radial head prosthesis diameter on posterolateral rotatory instability of the elbow

BACKGROUND

The purpose of this study is to investigate how different diameters of radial head replacement affect posterolateral translation with a valgus and supination force. We hypothesized that there would be less posterolateral rotatory translation with larger implant diameter.

METHODS

Eleven cadaveric arms were stressed at 30 and 60° of flexion with a consistent supination and valgus stress force under five conditions: native radial head, radial head excision, and with 3 sizes of radial head prosthesis. Displacement of the radial head posteriorly in relation to the capitellum on radiographs was measured. Displacement was expressed as a percentage relative to the average of the maximum and minimum native radial head diameters.

FINDINGS

The native radial heads had average minimum and maximum diameters of 23.3 mm and 25.2 mm, respectively. The angle of testing did not significantly change translation of the radial head. There was increased posterior translation relative to native head as the radial head sizes decreased from 24 mm to 20 mm and with excision of the radial head. Compared to the native head, the differences in displacement were statistically significant for the 20 mm radial head, but not for the 22 mm or 24 mm replacements. Radial head translation significantly increased after radial head excision.

INTERPRETATIONS

This cadaveric study illustrates that patients treated with radial head excision and radial head prosthesis with undersized diameters have increased posterior translation with a valgus and supination stress. The larger the radial head prosthesis (closer to native radial head), the more closely it approximated the amount of translation of the native radial head.

Comminuted Radial Head Fracture in All-arthroscopic Repair of Elbow Fracture-dislocation: Is Partial Excision of the Radial Head an Acceptable Treatment Option?

Background

In elbow fracture-dislocation, partial excision of the comminuted radial head fracture that is not amenable to fixation remains controversial considering the accompanying symptoms. This study was undertaken to evaluate the results of radial head partial excision when the comminuted radial head fracture involved <50% of the articular surface in all-arthroscopic repair of elbow fracture-dislocation.

Methods

Patients were divided into two groups based on the condition of the radial head fracture. In Group A, the patients had a radial head comminuted fracture involving <50% of the articular surface, and underwent arthroscopic partial excision. Group B was the non-excision group comprising patients with stable and non-displacement fractures. Follow-up consultations were conducted at 6 weeks and at 3, 6, 12, and 24 months after surgery.

Results

In all, 19 patients (Group A: 11; Group B: 8) met the inclusion criteria and were enrolled in the study. At the final follow-up, all 19 patients showed complete resolution of elbow instability. No significant differences were observed in the range of motion, visual analogue scale score, and Mayo elbow performance score between groups. Radiological findings did not show any complications of the radiocapitellar joint. However, nonunion of the coracoid fracture was observed in 3 patients (Group A: 1; Group B: 2), without any accompanying instability and clinical symptoms.

Conclusions

Considering that the final outcome is coronoid fracture fixation and lateral collateral ligament complex repair for restoring elbow stability, arthroscopic partial excision for radial head comminuted fractures involving <50% of articular surface is an effective and acceptable treatment for elbow fracture-dislocation.

Capitellar erosion after radial head arthroplasty: A comparative biomechanical study of operated radial head fractures on cadaveric specimens

BACKGROUND

We asked whether open reduction and internal fixation (ORIF) or radial head arthroplasty (RHA), common techniques used for the confrontation of displaced or comminuted radial head fractures, are correlated with cartilage wear of the capitulum.

HYPOTHESIS

We hypothesized that neither ORIF nor RHA are correlated with capitellar cartilage wear.

MATERIAL AND METHODS

On 5 cadaveric elbow specimens, osteotomies were employed to simulate radial head comminuted fractures followed with ORIF by Herbert screws. Radial heads were also excised from other 5 cadaveric elbow specimens and were replaced by metallic monopolar implants. Finally, 2 elbows were not operated and used as a control group. Custom-made rotary machines, working unstoppably, generated 700,000 pronation and supination forearm movements at a 110° arc of motion. The elbow joints were examined with pre- and postoperative magnetic resonance imaging (MRI) scans and the articular surfaces of the capitula were resected and sent for histopathology study.

RESULTS

In the 2 cadaveric elbows of the control group and the 4 elbows treated with ORIF, no cartilage damage was found. The fifth one displayed cartilage fissures, which were, classified according to International Cartilage Repair Society (ICRS) grading system as grade I cartilage damage. On the contrary, all 5 elbows treated with RHA sustained complete cartilage loss, exposure of the subchondral bone and were classified as ICRS grade IV cartilage damage.

DISCUSSION

Our study suggests that metallic monopolar RHA after a displaced or comminuted radial head fracture carries a high risk of rapidly evolving cartilage loss of the capitulum.

Complications after radial head arthroplasty: a comparison between short-stemmed bipolar and monopolar long-stemmed osteointegrative rigidly fixed prostheses

INTRODUCTION

To date, only a few studies have compared radial head prostheses (RHP) and their different anchoring principles. The aim of this study was to characterize concomitant injuries, necessary adjuvant procedures, complications, and radiological findings after implantation of two different types of RHP.

METHODS

Sixty-six patients with radial head fractures were treated with MoPyC (Tornier/France, 50 mm stem, monopolar) or SBI rHead prostheses (Small Bone Innovations/USA, 22-mm stem, bipolar) and followed up over 42 months (16-64 months). Primary objective was the detection of different loosening and explantation rates. In addition to the revision rate and the reasons for revision, we also used radiological findings to assess the dynamics of lysis phenomena.

RESULTS

Thirty-five patients (mean age 48 years; 22-73 years) were treated with the MoPyC, and 31 patients (mean age 47 years, 19-69 years) with the rHead prosthesis. Of these, 98% had a Mason 3 or 4 type of radial head fracture, and 94% showed concomitant injuries, which were addressed in 89% of cases by adjuvant procedures. The surgical revision rate was 20% (rHead 23%; MoPyC 18%). Significantly more of the rHead prostheses had to be explanted compared to MoPyC prostheses because of painful loosening (16% vs. 3%; p = 0.029). Predictors of subsequent loosening were significant radiolucent lines in the RHP over the first six months and an increase in width by two and a half times within the first 50 days after implantation.

CONCLUSION

Complex radial head fractures are frequent and difficult to treat. The monopolar long-stemmed prosthesis showed significantly lower rates of painful loosening and explanation rates than the bipolar short-stemmed prosthesis.

The radiocapitellar synovial fold: a lateral anatomic landmark for sizing radial head arthroplasty

BACKGROUND

Successful radial head arthroplasty relies on reproduction of anatomy. We hypothesized that the radiocapitellar synovial fold could serve as a reference point in radial head prosthesis sizing. Our study aimed to define the relationship between the synovial fold and the radial head in elbows with and without lateral ulnar collateral ligament (LUCL) injury.

MATERIALS AND METHODS

We performed magnetic resonance imaging evaluation of 34 elbows to determine the normal relationship between the radiocapitellar synovial fold and the radial head. Next, we used cadaveric dissections to evaluate the anatomic relationships with the LUCL intact and disrupted, as well as in the setting of sizing with a radial head prosthesis. The fold-to-radial head distance (FRHD) was measured on all images and analyzed to determine the relationship of the synovial fold and radial head.

RESULTS

The FRHD in cadavers with an intact LUCL and native radial head measured an average of 1.5 mm proximal to the radial head. With the LUCL disrupted and a native radial head, the FRHD measured an average of 1.2 mm proximal to the radial head. The mean difference between the groups was 0.5 mm (P = .031), suggesting that the fold migrated distally in the cadavers with a disrupted LUCL.

CONCLUSION

The radiocapitellar synovial fold may be a helpful landmark for radial head sizing. The synovial fold is always just proximal to the articular surface of the radial head. Using this information, the surgeon can prevent overlengthening as the implant should not be placed proximal to the fold.

Mid-term results of alumina ceramic unlinked total elbow arthroplasty with cement fixation for patients with rheumatoid arthritis

Aims

The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA).

Patients and Methods

We retrospectively reviewed 87 elbows, in 75 patients with RA, which was replaced using a cemented JACE total elbow arthroplasty (TEA) between August 2003 and December 2012, with a follow-up of 96%. There were 72 women and three men, with a mean age of 62 years (35 to 79). The mean follow-up was nine years (2 to 14). The clinical condition of each elbow before and after surgery was assessed using the Mayo Elbow Performance Index (MEPI, 0 to 100 points). Radiographic loosening was defined as a progressive radiolucent line of >1 mm that was completely circumferential around the prosthesis.

Results

The mean MEPI scores significantly improved from 40 (10 to 75) points preoperatively to 95 (30 to 100) points at final follow-up (p < 0.0001). Complications were noted in ten elbows (ten patients; 11%). Two had an intraoperative humeral fracture which was treated by fixation and united. One had a postoperative fracture of the olecranon which united with conservative treatment and one had a radial neuropathy which resolved. Further surgery was required for one with a dislocation, three with an ulnar neuropathy and one with a postoperative humeral fracture. Revision with removal of the components was performed in one elbow due to deep infection. There was no radiographic evidence of loosening around the components.With any revision surgery or revision with implant removal as the endpoint, the rates of survival up to 14 years were 93% (95% confidence interval (CI), 83.9 to 96.6) and 99% (95% CI 91.9 to 99.8), respectively, as determined by Kaplan-Meier analysis.

Conclusion

With the appropriate indications, the mid-term clinical performance of the cemented JACE TEA is reliable and comparable to other established TEAs in the management of the elbow in patients with RA.

Cite this article: Bone Joint J 2018;100-B:1066–73.

Operative Management of Unstable Radial Head Fractures in a Young Active Population

BACKGROUND

Radial head and neck fractures are the most common elbow fracture in the general adult population; however, the optimal treatment for radial head fractures remains a topic of ongoing clinical controversy. The purpose of this study was to determine the rate of return to function, complications, and reoperation following operative management of unstable radial head fractures in a young, active patient population with intense upper extremity demands.

METHODS

A military health care database was queried for all US military servicemembers undergoing open reduction with internal fixation (ORIF; Current Procedural Terminology [CPT] code: 24665) and radial head arthroplasty (RHA; CPT code: 24666) between 2010 and 2015. All patients with minimum 2-year follow-up were included. Univariate and chi-square analyses were performed to evaluate the association between potential risk factors and the primary outcome measures.

RESULTS

A total of 67 ORIF (n = 69 elbows) and 10 RHA patients were included. The average age was 31 ± 8.0 years. At mean follow-up of 3.5 ± 1.1 years, 90% of patients overall were able to return to active military service, 96% of which with unrestricted upper extremity function. Nearly one-third (31.2%) of patients developed at least 1 postoperative complication. RHA has higher overall complication rates (70% vs 48%) when compared with ORIF, but this finding did not reach statistical significance ( P = .073). However, RHA had significantly higher rates of implant failure (20% vs 2.9%, P = .0498). Seventeen (21%) individuals required reoperation, 5 of which (6.3%) were revision procedures. Dislocation, coronoid fracture, and concomitant ligamentous repair portended a significantly increased risk of sustaining 1 or more complications ( P < .05), while dislocation and requirement for ligamentous repair independently predicted revision surgery ( P < .05).

CONCLUSIONS

Arthroplasty and ORIF are both viable options for treating unstable radial head fractures in a young, athletic population, offering comparable return to function despite increased complications with RHA.