Minimum four-year clinical outcomes after on-table reconstruction technique for Dubberley type III in coronal shear fractures of the capitellum and trochlea: a report of 10 patients.

PURPOSE: Comminuted coronal shear fractures of the distal humerus represent rare injuries and are difficult to treat, especially comminuted capitellum and trochlear fractures (Dubberley Type III). The on-table reconstruction technique of comminuted articular fractures may be an option, although it has not been reported in the coronal shear fracture of the distal humerus. The aim of the present case series is to determine the functional and radiological outcomes of on-table reconstructed Dubberley III fractures. METHODS: A retrospective review was conducted of 10 patients with Dubberley type III fractures in coronal shear fractures of the capitellum and trochlea who underwent an 'on-table' reconstruction technique between January 2009 and October 2019. All patients were evaluated using the disabilities of the arm, shoulder, and hand (DASH) score, American Shoulder and Elbow Surgeons(ASES) score, Mayo Elbow Score Performance Index (MEPI) score and at least 4 years later. RESULTS: All cases achieved union. At the final follow-up, the mean range of elbow motion was 11.5°of flexion contracture and 131.9° of further flexion. The mean DASH score was 21.2 (5.7) points (range 13.3-32.5). The mean ASES score was 88.6 ± 7.4 (range, 77 to 100). The mean MEPI score was 87 (10) points (range 70-100). In complication, partial osteonecrosis of capitellum is developed in one patient. One patient had heterotopic ossification without functional impairment. CONCLUSION: The on-table reconstruction technique can be a reliable option in the surgical treatment of complex distal humerus fractures. This technique allows anatomical reduction of comminuted capitellum and trochlea, with a low risk of avascular necrosis over 4 years of follow-up. LEVEL OF EVIDENCE: Level IV, retrospective case series.

A Comparison of Treatment of OCD Lesions of the Capitellum With Osteochondral Autograft and Allograft Transplantation.

Osteochondritis dissecans (OCD) of the capitellum occurs relatively infrequently but can be found in young overhead-throwing athletes, most commonly in baseball players and gymnasts. Although non-operative management can effectively treat stable lesions, unstable lesions can lead to debilitating symptoms of the elbow and diminished quality of life without surgical intervention. This article reviews methods of treating OCD of the capitellum categorized by stability, size, and patient characteristics, and seeks to familiarize the reader with the appropriate selection of osteochondral allograft versus autograft in treating large, unstable lesions. We complement this review with 3 case examples, each using either an osteochondral autograft or allograft, and discuss the decision-making methodology used in each case.

Current concepts: pathology in the overhead athlete's lateral elbow.

The lateral elbow is subjected to increasing compressive force in response to repetitive valgus stress. Alterations or deficiencies in overhead mechanics and the kinetic chain may predispose an athlete to injury. Evaluation includes a focused elbow physical examination and imaging, supplemented by a robust screening of core strength, balance, and mechanics of the kinetic chain. Treatment of osteochondritis dissecans, a common lateral elbow pathology, varies based on stability of the lesion, with variable, but often positive outcomes. Proper pitching mechanics, kinetic chain integrity, and workload management provide potential opportunities for prevention.

Optimal Screw Orientation for Fixation of Coronal Shear Fractures: A Biomechanical Comparison.

OBJECTIVE: Coronal shear fractures of the capitellum are rare injuries which can be challenging to treat. The aim of this study was to compare the biomechanical properties of different internal screw fixation techniques for Dubberley type IA fractures of the capitellum. METHODS: In this biomechanical study, Dubberley type IA fractures of the capitellum were created in 30 human fresh-frozen humeri. The specimens were then divided into three groups: fixation was either performed with 3 x 3.0 mm headless cannulated compression screws (HCCSs) in anteroposterior (AP) orientation (AP group), 3 x 3.0 mm HCCSs in posteroanterior (PA) orientation (PA group) or with 2 x 3.0 mm HCCSs in PA orientation and 1 x 3.0 mm HCCS in lateral orientation (LAT group). Displacement under cyclic loading and ultimate load-to-failure were evaluated in all specimens. RESULTS: There was no significant difference in fragment displacement after 2000 cycles between AP and PA groups (0.8 ± 0.5 mm vs. 0.8 ± 0.6 mm; p = 0.987) or PA and LAT groups (0.8 ± 0.6 mm vs. 0.8 ± 0.3 mm; p = 0.966). LAT group showed the highest load-to-failure (548 ± 250 N) without reaching statistically significant difference to AP group (388 ± 173 N; p = 0.101). There was also no significant difference between AP and PA groups (388 ± 173 N vs. 422 ± 114 N; p = 0.649). CONCLUSIONS: Variations in screw placement had no statistically significant influence on cyclic displacement or load-to-failure in Dubberley Type IA fractures. However, fracture fixation in two planes - both the coronal and the sagittal plane - by adding a screw in a lateral to medial direction may be beneficial to increase primary stability.

Surgical approaches to the capitellum: a comparative anatomic study.

BACKGROUND: Osteochondritis dissecans (OCD) of the humeral capitellum is an important cause of elbow disability in young athletes. Large and unstable lesions sometimes require joint reconstruction with osteochondral autograft. Several approaches have been described to expose the capitellum for the purpose of treating OCD. The posterior anconeus-splitting approach and the lateral approach with or without release of the lateral ligamentous complex are the most frequently used for this indication. The surface accessible by these approaches has not been widely studied. This study compared the extent of the articular surface of the capitellum that could be exposed with the Kocher approach (without ligament release) vs. the posterior anconeus-splitting approach. A secondary outcome was the measurement of any additional area that could be reached with lateral ulnar collateral ligament release (Wrightington approach). METHODS: The 3 approaches were performed on 8 adult cadaveric elbows: first, the Kocher approach; then, the anconeus-splitting approach; and finally, the Wrightington approach. The visible articular surface was marked out after completion of each approach. RESULTS: The mean articular surface of the capitellum was 708 mm2 (range, 573-830 mm2). The mean visible articular surface was 49% (range, 43%-60%) of the total surface with the Kocher approach, 74% (range, 61%-90%) with the posterior anconeus-splitting approach, and 93% (range, 91%-97%) with the Wrightington approach. Although the Kocher approach provided access to the anterior part of the capitellum, the anconeus-splitting approach showed adequate exposure to the posterior three-quarters of the articular surface and overlapped the most posterior part of the Kocher approach. A combination of the 2 lateral ulnar collateral ligament-preserving approaches allowed access to 100% of the joint surface. CONCLUSION: Most OCD lesions are located in the posterior area of the capitellum and can therefore be reached with the anconeus-splitting approach. When OCD lesions are located anteriorly, the Kocher approach without ligament release is efficient. A combination of these 2 approaches enabled the entirety of the joint surface to be viewed.

Magnetic Resonance Imaging Assessment of Cartilage Appearance Following Marrow Stimulation of Osteochondritis Dissecans of the Humeral Capitellum.

PURPOSE: Osteochondritis dissecans (OCD) of the capitellum is often treated by marrow stimulation techniques with good long-term outcomes. Magnetic resonance imaging (MRI) can be used to characterize the healing of cartilage repair tissue. However, no formal system exists for assessment of cartilage healing after marrow stimulation in capitellar OCD. The aims of this study were to describe the postoperative MRI appearance of capitellar repair cartilage after debridement and marrow stimulation for capitellar OCD and assess differences between symptomatic and asymptomatic patients. METHODS: This was a retrospective study of patients with capitellar OCD who underwent arthroscopic debridement and marrow stimulation and had a postoperative MRI to assess healing. The classification system developed by Marlovits and colleagues (Magnetic Resonance Observation of Cartilage Repair Tissue) was used to quantitatively profile the cartilage repair tissue in comparison to adjacent "normal" cartilage. Study participants completed an online survey to correlate outcomes with cartilage appearance. RESULTS: Eleven patients who underwent MRI for routine evaluation (asymptomatic), and 18 who underwent MRI for symptoms were identified. Overall, 59% of defects were completely filled, and in 83%, the cartilage surface had ulcerations or fibrillations. The cartilage variables were similar between symptomatic and asymptomatic patients. Capitellar subchondral bone edema was observed on the MRI of every patient who underwent a reoperation and was present in only 62% of those who did not. Clinical scores did not correlate with MRI cartilage findings, but the small sample size limited conclusions regarding clinical outcomes related to postoperative cartilage features seen on MRI. CONCLUSIONS: This detailed assessment of cartilage appearance by MRI after marrow stimulation for capitellar OCD demonstrated that incomplete cartilage fill was common in both symptomatic and asymptomatic patients. Those requiring a second surgery were more likely to demonstrate subchondral bone edema. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Rate of Complications After Capitellum Fracture Fixation: A Systematic Review and Meta-Analysis.

PURPOSE: This systematic review aimed to determine the incidence of complications following surgical fixation of an acute capitellum fracture. We secondarily aimed to compare the complication rate between anterior-to-posterior (A-P) versus posterior-to-anterior (P-A) screw insertion. METHODS: PubMed, EMBASE, and Scopus were searched to identify studies on surgical fixation of capitellum fractures in skeletally mature patients. The main outcome was the rate of complication after fracture fixation. Subgroup analysis was performed to assess the impact of the fixation technique on the outcomes after surgery. An inverse variance method using random or fixed effects models was used to perform a meta-analysis based on the degree of heterogeneity between studies. Study heterogeneity was evaluated using Q statistics to calculate the I2 index. RESULTS: We included 42 studies in the final analysis. The most reported complications after surgical fixation of capitellum fractures included elbow pain (21%), radiocapitellar arthritis (19%), hardware removal (17%), and heterotopic ossification (13%). When groups were stratified based on the direction of screw insertion, the mean rate of avascular necrosis was higher in the P-A direction (29% vs 11%). In comparison, the rate of revision fixation (2.9% vs 6.7%) and heterotopic ossification (7.3% vs 22%) were higher in the A-P direction. Transient posterior interosseous nerve palsy was reported in four patients in four studies, of whom three patients had A-P screw fixation. CONCLUSION: Fixation of a displaced capitellum fracture is recommended when possible. However, patients should be counseled about the potential risk of complications and chances of undergoing an unplanned surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Capitellum Osteochondral Allograft Transplantation for Osteochondritis Dissecans of the Elbow.

Reconstruction of unstable osteochondritis dissecans lesions of the capitellum using fresh osteochondral allograft transplantation from the capitellum has the advantages of restoring hyaline cartilage, matching the native radius of curvature, and avoiding the donor-site morbidity encountered with osteochondral autograft transfer. This technical note describes the indications and contraindications, pertinent anatomy, and surgical technique of open osteochondral allograft transplantation using fresh distal humerus allograft for the treatment of unstable osteochondritis dissecans lesions of the capitellum.

A Quantitative Analysis of Subchondral Bone Density Around Osteochondritis Dissecans Lesions of the Capitellum.

PURPOSE: In capitellar osteochondritis dissecans (OCD), unstable lesions generally demonstrate signs of subchondral sclerosis. We postulate that OCD lesions have abnormal subchondral bone density. We aimed to quantify the subchondral bone thickness around OCD lesions using conventional computed tomography (CT) imaging. METHODS: This retrospective study included 15 patients with capitellar OCD (OCD group) and 12 patients with an unaffected radio-capitellar joint (control group). We constructed 3-dimensional humerus models using CT data and quantified the bone density with colored contour mapping to determine the subchondral bone thickness. We measured the thickness relative to the condylar height at the centroid and lateral, medial, superior, and inferior edge points of the OCD lesion, and compared the findings between the groups. We then correlated the CT measurements with the magnetic resonance imaging measurements. RESULTS: Subchondral bone thickness at the centroid and lateral, medial, superior, and inferior edges in the OCD group was significantly higher than that in the control group. Correlation analyses revealed that the magnetic resonance imaging measurements highly correlated with the CT subchondral bone measurements. CONCLUSIONS: We found that there is a zone of increased subchondral bone thickness around OCD lesions that should be considered during drilling, microfracture, or other reconstruction methods. We observed a high correlation with low errors between the measurements taken from conventional CT images and the measurements from magnetic resonance imaging, suggesting that both modalities are useful in clinical decision making. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Anatomic study of an anterior portal for percutaneous internal fixation of capitellum fractures.

BACKGROUND: Fractures of the capitellum are uncommon and difficult to treat surgically. Capitellar open reduction-internal fixation uses a lateral open approach with posterior-to-anterior or anterior-to-posterior screw fixation. We investigated the use of an anterior portal for placement of anterior-to-posterior screw fixation through cadaveric measurement of the anatomic relationships from an anteriorly to posteriorly placed Kirschner wire (K-wire) to anterior elbow structures and calculated the percentage of articular surface accessed from the anterior portal. METHODS: Eight fresh-frozen cadaveric elbows without radiographic or cutaneous evidence of prior trauma or surgery were used for this study. An arthroscopic proximal anteromedial portal was cannulized, and the radiocapitellar joint was evaluated. A single 1-cm portal was placed 1 cm distal to the elbow flexion crease and based lateral to the biceps tendon. The location of the portal was confirmed with a spinal needle, and blunt dissection with a hemostat was performed down to capsular tissue and for arthrotomy. A spinal needle sheath was threaded over a blunt switching stick and served as a cannula for placement of a 0.062 K-wire. Articular mapping was performed with cartilage scraping by the K-wire; the K-wire was then placed at the perceived center along the proximal-to-distal and radial-to-ulnar axis of the capitellum. Fluoroscopic confirmation of the wire's location was performed. Under loupe magnification, anatomic dissection was performed and the shortest distance measurements were recorded with digital calipers from the K-wire to the dissected structures. Capitellar articular measurements were recorded, in addition to the articular area defined by the K-wire. Data analysis was performed, and the average distance and standard deviation (in millimeters) were calculated. For structures that were pierced by or touching the K-wire, the distance was recorded as 0.1 mm. RESULTS: The average distance from the K-wire to the radial, lateral antebrachial cutaneous, and median nerves was 1.8 mm, 11.5 mm, and 28.0 mm, respectively. The average distance from the median cubital vein and biceps tendon was 3.7 mm and 13.4 mm, respectively. The pin track pierced the brachioradialis and supinator muscles in all but 1 specimen. The average capitellar articular surface marked was 39.1% of the calculated articular footprint of the capitellum. CONCLUSIONS: The anterior portal to the capitellum is directly adjacent to the radial nerve and lateral antebrachial cutaneous nerve, where each is susceptible to injury. We recommend blunt dissection and insertion of a cannula to allow drilling and placement of internal fixation in a relatively safe manner with respect to neurovascular structures.

Biomechanical stability of complex coronal plane fracture fixation of the capitellum.

INTRODUCTION: Coronal plane fractures of the distal humerus are relatively rare and can be challenging to treat due to their complexity and intra-articular nature. There is no gold standard for surgical management of these complex fractures. The purpose of this study was to compare the biomechanical stability and strength of two different internal fixation techniques for complex coronal plane fractures of the capitellum with posterior comminution. MATERIALS AND METHODS: Fourteen fresh frozen, age- and gender-matched cadaveric elbows were 3D-navigated osteotomized simulating a Dubberley type IIB fracture. Specimens were randomized into one of two treatment groups and stabilized with an anterior antiglide plate with additional anteroposterior cannulated headless compression screws (group antiGP + HCS) or a posterolateral distal humerus locking plate with lateral extension (group PLP). Cyclic testing was performed with 75 N over 2000 cycles and ultimately until construct failure. Data were analyzed for displacement, construct stiffness, and ultimate load to failure. RESULTS: There was no significant difference in displacement during 2000 cycles (p = 0.291), stiffness (310 vs. 347 N/mm; p = 0.612) or ultimate load to failure (649 ± 351 vs. 887 ± 187 N; p = 0.140) between the two groups. CONCLUSIONS: Posterolateral distal humerus locking plate achieves equal biomechanical fixation strength as an anterior antiglide plate with additional anteroposterior cannulated headless compression screws for fracture fixation of complex coronal plane fractures of the capitellum. These results support the use of a posterolateral distal humerus locking plate considering the clinical advantages of less invasive surgery and extraarticular metalware. LEVEL OF EVIDENCE: Biomechanical study.

Outcomes of Osteochondral Autograft Transplantation in Pediatric Patients With Osteochondritis Dissecans of the Capitellum.

PURPOSE: To assess the outcomes of osteochondral autograft transplantations in the treatment of osteochondritis dissecans of the capitellum in the pediatric population. METHODS: Between 2011 and 2016, 15 patients who had undergone osteochondral autograft transplantation at a mean age of 13.7 years at surgery were identified. The donor site was from the superolateral, non-weight-bearing surface of the lateral femoral condyle of the ipsilateral knee. RESULTS: Mean follow-up was 29.5 months, with no patients lost to follow-up. Mean arc of motion increased significantly from 121.9° preoperatively to 139.1° postoperatively. All 9 elite athletes returned to sports at an elite level: 7 returned to the same level of competition in the same sport, 1 retired from gymnastics due to multiple injuries but began diving at an elite level, and 1 retired from baseball unrelated to elbow symptoms but continued hockey at the same level. Of the 4 recreational athletes, all returned to sport. There were no intraoperative complications. The symptoms resolved completely in all but 2 patients, who improved over their preoperative condition. The donor site knee pain resolved in all patients at an average of 2.3 months. Postoperative imaging demonstrated the healing and incorporation of the plug in all patients. CONCLUSIONS: In the treatment of osteochondritis dissecans of the capitellum, osteochondral autograft transplantation demonstrates excellent clinical and radiographic outcomes, with minimal short-term donor site morbidity and a high level of return to the sport. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Early Improvement in Patient-Reported Outcome Scores After Operative Treatment of Osteochondritis Dissecans of the Humeral Capitellum.

PURPOSE: Outcome measures that lack sensitivity for the detection of clinical changes early after surgery for capitellar osteochondritis dissecans (OCD) make it difficult to determine the optimal treatment for these defects. We sought to evaluate the early responsiveness of patient-reported outcomes measurement information system (PROMIS) scores in a cohort of patients operatively treated for capitellar OCD. METHODS: Four PROMIS questionnaires (mobility, upper extremity [UE], pain interference, and peer relations) were electronically administered to patients treated for capitellar OCD at a single tertiary academic medical center between January 1, 2015, and July 1, 2018. The questionnaires were administered at the initial preoperative outpatient clinic visit as well as at the 2-week, 6-week, and final return-to-play (RTP) visits. RESULTS: Twenty-nine patients (31 elbows, mean age 12.9 years) with available preoperative and postoperative PROMIS data were included. The mean final follow-up period was 26 weeks. Compared with that before surgery, there was a significant improvement in the mobility, pain interference, and UE scores at 6 weeks following surgery. The scores improved most significantly by 6 weeks, reached a relative plateau, and remained significantly improved through the RTP visit thereafter. Patients with preoperative, intra-articular loose bodies scored significantly better than those without them during the 6-week and RTP visits. Patients with lesions >1 cm2, compared with those with lesions ≤1 cm2, demonstrated greater improvement in the UE scores during the RTP visit. CONCLUSIONS: In patients undergoing operative treatment for capitellar OCD, a significant improvement in the PROMIS domains of mobility, pain interference, and UE can be expected early in the postoperative period, with majority of patients reaching their greatest improvement in scores by 6 weeks following surgery. CLINICAL RELEVANCE: This is important information for preoperative counseling. In addition, this information is helpful in confirming that PROMIS scores are responsive in the detection of changes in outcomes during the early postoperative period in this population.

Magnetic Resonance Imaging in Osteochondritis Dissecans of the Humeral Capitellum: Preoperative Assessment of Lesion Size and Lateral Wall Integrity.

PURPOSE: Magnetic resonance imaging (MRI) is a helpful tool in the evaluation of osteochondritis dissecans (OCD) of the humeral capitellum. The relationship between MRI appearance and clinically relevant intraoperative findings is incompletely understood. The goal of this study was to evaluate capitellar OCD lesions via preoperative MRI and to determine its accuracy in predicting lesion characteristics including lesion size and capitellar lateral wall integrity. METHODS: Patients surgically treated for capitellar OCD between January 2010 and June 2018 were reviewed. Preoperative MRI images were assessed by a musculoskeletal radiologist with documentation of lesion size, location, violation of the lateral wall, and stage, in accordance with previously established criteria. These data were compared with intraoperative findings. Involvement of the lateral wall of the capitellum was defined using 2 methods: (1) subchondral edema or articular cartilage disruption in the lateral third of the capitellum (lateral third method) or (2) disruption of the proximal-distal subchondral line along the lateral border of the capitellum descending vertically before the subchondral bone turns horizontally to form the radiocapitellar articulation (capitellar lateral wall sign method). Diagnostic test characteristics were compared for both methods. RESULTS: We reviewed the preoperative MRIs of 33 elbows with capitellar OCD and found no significant difference in mean lesion size between preoperative MRI (1.12 cm2) and intraoperative measurement (1.08 cm2). For detection of lateral wall integrity, preoperative MRI evaluation using the capitellar lateral wall sign method had an accuracy of 93%, sensitivity of 80%, specificity of 96%, positive predictive value of 80%, and negative predictive value of 96%. CONCLUSIONS: Preoperative MRI is a valid predictor of lesion size. The capitellar lateral wall sign method is highly accurate in the identification of lateral wall involvement, which may influence preoperative planning. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

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.

Performance of Patient-Reported Outcomes Measurement Information System (PROMIS) scores compared with legacy metrics in evaluating outcomes after surgical treatment for osteochondritis dissecans of the humeral capitellum.

BACKGROUND: Patient-Reported Outcomes Measurement Information System (PROMIS) scores have not previously been used to measure long-term outcomes in operatively treated capitellar osteochondritis dissecans (OCD) patients. The aims of our study were to (1) assess patients' long-term outcomes using PROMIS scores, (2) compare the performance of PROMIS with other validated elbow legacy metrics, and (3) evaluate ceiling and floor effects in these outcome measures in patients undergoing surgical treatment for capitellar OCD. METHODS: We evaluated demographic characteristics, procedure details, preoperative PROMIS scores, and associated sports information in surgically treated pediatric capitellar OCD patients. An online survey was sent to the study participants, including the Kerlan-Jobe Orthopaedic Clinic (KJOC) shoulder and elbow score, the quick Disabilities of the Arm, Shoulder and Hand questionnaire, and the Liverpool Elbow Score patient-answered questionnaire, as well as the Mobility, Pain Interference, and Upper Extremity questionnaires from the PROMIS pediatrics bank. Correlations were evaluated between outcome measures. Ceiling and floor effects were evaluated for each outcome measure. RESULTS: Completed surveys were obtained for 57 patients (59 elbows). The mean patient age at surgery was 14 years (range, 10-18 years). The mean follow-up time was 6 years (standard deviation, 5 years; range, 1-18 years). The mean PROMIS Mobility score improved from 41.2 preoperatively to 55.2 postoperatively (P < .001). The mean Pain Interference score decreased from 46.9 preoperatively to 38 postoperatively (P < .001). The mean Upper Extremity score improved from 42.7 preoperatively to 53.2 postoperatively (P < .001). Significant correlations were observed between all legacy metrics and postoperative PROMIS scores (|r| > 0.54, P < .001). Ceiling or floor effects were seen in all legacy metrics and PROMIS scores. The KJOC score was least affected by ceiling or floor effects. CONCLUSION: There is a strong correlation between PROMIS scores and legacy measures evaluating outcomes after surgical management of capitellar OCD. However, large ceiling and floor effects were present in all measures, likely owing to the favorable clinical results. The KJOC score was limited the least by ceiling and floor effects.

Biomechanical stability of simple coronal shear fracture fixation of the capitellum.

BACKGROUND: Coronal shear fractures of the capitellum are rare, and their surgical management is challenging, without a defined gold standard. The purpose of this study was to compare the biomechanical stability of 3 different internal fixation techniques for simple coronal shear fractures of the capitellum without posterior comminution. METHODS: Dubberley type IA fractures of the capitellum were created in 18 cadaveric elbows, which were age and sex matched to the following 3 internal fixation groups: (1) two anteroposterior cannulated headless compression screws (HCSs), (2) two anteroposterior HCSs with an additional anterior antiglide plate (antiGP), and (3) a posterolateral distal humeral locking plate (LP). All fixation techniques were cyclically loaded with 75 N over 2000 cycles and ultimately until construct failure. Data were analyzed for displacement, construct stiffness, and ultimate load to failure. RESULTS: Fragment displacement under cyclic loading with 2000 cycles did not show a significant difference (P = .886) between the 3 groups. The HCS group showed the highest stiffness compared with the HCS-antiGP and LP groups (602 N/mm vs. 540 N/mm vs. 462 N/mm, P = .417), without reaching a statistically significant difference. Ultimate load to failure was also not significantly different on comparison of all 3 groups (P = .297). CONCLUSIONS: Simple coronal shear fractures of the capitellum are biomechanically equally stabilized by HCSs compared with HCSs with an additional antiGP or a posterolateral distal humeral LP. In view of the advantages of less (invasive) metalware, the clinical use of 2 isolated anteroposterior HCSs appears reasonable.

Surgical tips and tricks for coronal shear fractures of the elbow.

INTRODUCTION: Coronal shear fractures of the distal humerus represent an uncommon lesion and could be burdened by high complications. This complex lesion requires an accurate reduction and surgical fixation for a better outcome. Different techniques have been described, however no standard protocol have been proposed. Purpose of this retrospective study, is to evaluate the clinical and radiological outcome with posterior cannulated self-tapping headless screws followed by an early-active-motion protocol and to outline the surgical tips and tricks for different fracture patterns. MATERIALS AND METHODS: From 2013 to 2019, a consecutive series of 24 patients with coronal shear fracture undergoing ORIF were included in the study. Fractures were classified according to Dubberley's classification. Cannulated self-tapping headless screws were used to fix the fragments. When necessary, additional cannulated half-threaded screws on the lateral edge of the humerus were used, as well as bone chips and fibrin sealant on severe comminution. All patients underwent an assisted early-active-motion rehabilitation protocol. Mean follow-up was 30 months; patients underwent standard X-rays and clinical outcome assessment with range of motion, Broberg and Morrey score and MEPI score. RESULTS: Surgical fixation with headless screw guaranteed complete healing of all shear fractures examined, no loss of reduction were reported. ROM assessment showed good results with an average arc of 113.1°. Excellent to good Broberg-Morrey and MEPI score were reported. No cases of avascular necrosis nor post-traumatic osteoarthritis resulted in our series. Complications occurred in 16.6% of the patients. CONCLUSION: Coronal shear fracture represents a challenging injury to treat. Anatomical reduction and the use of cannulated self-tapping headless screws from posterior provide a stable fixation, high union rates and good elbow function, with a low cartilage damage and risks of necrosis over 2 years of follow-up. LEVEL OF EVIDENCE: Therapeutic III.

Osteochondritis Dissecans of the Elbow in Children: MRI Findings of Instability.

OBJECTIVE. The purpose of this study was to investigate the performance of MRI criteria for predicting instability of osteochondritis dissecans (OCD) lesions of the elbow in children. MATERIALS AND METHODS. This retrospective study included 41 children with 43 OCD lesions of the elbow who underwent an MRI examination between April 1, 2010, and May 31, 2018. Two radiologists blinded to clinical outcomes reviewed MRI studies to determine the presence or absence of joint effusion, osteochondral defect, intraarticular body, overlying cartilage changes, subchondral bone disruption, rim of high signal intensity on T2-weighted images, cysts, marginal sclerosis, and perilesional bone marrow edema. The stability of OCD lesions was determined with clinical follow-up and surgical findings as reference standards. Mann-Whitney U, chi-square, Fisher exact, and Cochran-Armitage tests were used to compare MRI findings between stable and unstable OCD lesions. RESULTS. There were 20 stable and 23 unstable OCD lesions. An osteochondral defect (p = 0.01), intraarticular body (p < 0.001), overlying cartilage changes (p = 0.001), subchondral bone plate disruption (p = 0.02), and hyperintense rim (p = 0.01) were significantly more common in unstable than stable OCD lesions. However, only osteochondral defect and intraarticular body were 100% specific for OCD instability. There was no significant difference between stable and unstable OCD lesions in the presence of joint effusion (p = 0.10), cysts (p = 0.45), marginal sclerosis (p = 0.70), or perilesional bone marrow edema (p = 1.00). CONCLUSION. MRI findings of OCD instability of the elbow include an osteochondral defect, intraarticular body, overlying cartilage changes, subchondral bone disruption, and rim of high signal intensity on T2-weighted MR images.

Radiocapitellar arthroplasty: a consecutive case series with 2 to 6 years' follow-up.

BACKGROUND: The aim of this study was to analyze indications, outcomes, and complications in patients treated with radiocapitellar arthroplasty. METHODS: This prospective analysis of clinical and radiographic results included 16 elbows in 15 patients. RESULTS: This study included 4 men and 11 women (mean age, 51.9 years; age range, 32-65 years). The mean follow-up period was 3.4 years (range, 2-6 years). The indications were post-traumatic (n = 10) and primary radiohumeral osteoarthritis (n = 6). A mean of 2 surgical procedures (range, 0-4) had been performed before radiocapitellar arthroplasty. The mean Mayo Elbow Performance Score significantly improved from 46 points to 85 points (P < .01). The arc of motion improved from 106° to 117° (P = .27). Radiographic ulnohumeral degeneration progressed in 40% of cases but was not symptomatic in any. Subsequent surgery was required in 5 elbows (31%). Revision of the radial head component was necessary in 4 patients (25%). In 3 patients this was a result of loosening of the stem. The radial component was subsequently removed because of persistent pain in 1. Radiographic loosening not requiring revision was found in 2 patients. CONCLUSION: The overall Mayo Elbow Performance Score was good to excellent after radiocapitellar arthroplasty. Both the revision and reoperation rates were high, and one should consider this before performing this procedure. Loosening of the radial head component was a problem. An improved fixation technique or an adaptation of the design is needed before this type of surgery can be recommended as a standard procedure.