Strategic approach to O'Driscoll type 2 anteromedial coronoid facet fracture

The Challenge of Trans-Ulnar Basal Coronoid Fracture-Dislocations: A Surgical Strategy Based on the Pattern of Coronoid Fracture

Backgroud

The rarity and complexity of trans-ulnar basal coronoid fracture-dislocations pose significant challenges in treatment. This study aimed to categorize these fractures based on coronoid fracture patterns and propose tailored surgical approaches for each type. Additionally, we evaluated the functional and radiological outcomes among the patients managed using our treatment algorithm.

Methods

A total of 19 patients who underwent open reduction and internal fixation for trans-ulnar basal coronoid fracture-dislocations between March 2018 and October 2022 were enrolled in this study. These patients were classified based on the coronoid fracture patterns associated with olecranon fractures: type 1 involved anteromedial facet (AMF) fractures, type 2 encompassed coronoid base and body fractures, and type 3 involved a combination of types 1 and 2. We made a midline longitudinal dorsal incision to facilitate the provisional fixation of the olecranon fragment to the distal metaphysis using a locking plate. Subsequently, we employed the over-the-top (type 1) and Taylor-Scham (type 3) approaches for direct coronoid process fixation with buttress plating. Type 2 fractures were approached via medial fascial exposure from the posterior ulnar cortex or through the olecranon fractures, and subsequently fixed with miniplates and screws. Bony union and joint articulation were assessed via plain radiographs, and functional outcomes were evaluated using range of motion and the Mayo Elbow Performance Score.

Results

Among the 19 patients, 3 had type 1 fractures, 14 had type 2 fractures, and 2 had type 3 fractures. All fractures exhibited solid osseous union without subluxation or dislocation. The average flexion and extension arc was 119.47° ± 20.88°, with a mean flexion of 127.37° ± 13.37° and an average flexion contracture of 7.89° ± 10.04°. The average Mayo Elbow Performance Score was 82.63 ± 12.51 points. Qualitatively, patient outcomes were excellent in 5 patients, good in 9, and fair in 5.

Conclusions

Most of our patients presented with easily approachable coronoid base and body fractures. However, in AMF fractures of the coronoid process, a direct medial approach is required for buttress plating. We believe our study helps provide useful guidelines for making appropriate decisions in trans-ulnar basal coronoid fracture-dislocations.

Surgical outcomes and complication rates of arthroscopic-assisted fixation versus open fixation for coronoid fractures: A systematic review and meta-analysis

Background

Coronoid fractures often occur with complex elbow dislocations, accounting for 15% of elbow fractures. The effectiveness of open reduction internal fixation (ORIF) versus arthroscopic-assisted reduction internal fixation (ARIF) surgeries for coronoid fractures remains uncertain. This study aimed to compare the outcomes of these two surgical approaches in treating varus posteromedial injuries.

Methods

This study was conducted and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The study protocol was registered with PROSPERO. The primary outcomes assessed in this study were the functional outcomes measured by the Mayo Elbow Performance Score (MEPS) and the complications associated with each surgical approach.

Results

Analysis of the data from 759 patients included in this study revealed that the mean postoperative MEPS score was higher in the ARIF group compared to the ORIF group (97.5 Vs. 90.7), with the mean improvement in MEPS was 16.6 points (19 for ORIF and 14.3 for ARIF). The complication rate in the ORIF group was 24.6%, while the ARIF group reported a complication rate of 6%.

Conclusion

This study suggests that ARIF surgery can yield comparable and promising outcomes to ORIF surgery for coronoid fractures.

Level of evidence

IV.

Three-dimensional quantitative study and functional outcome analysis of coronoid fracture in different elbow injury patterns

BACKGROUND

Coronoid fractures are often part of a complex fracture-dislocation of the elbow. For an optimum prognosis, it is important to understand the characteristics of coronoid fractures in different elbow injury patterns. Significant differences in these characteristics have been observed in various studies, but these previous studies have suffered from limitations, such as insufficient quantification and unknown prognostic differences among different injury patterns. Therefore, we aimed to quantitatively analyze coronoid fracture characteristics and functional outcomes in different elbow injury patterns using three-dimensional computed tomography.

METHODS

All patients with coronoid fractures surgically treated at our hospital between January and December 2017 were categorized into 3 groups according to elbow injury pattern: posterolateral rotational instability (PLRI), varus posteromedial rotational instability (VPMRI), and olecranon fracture-dislocation (OFD). 3D models were reconstructed using Mimics 17.0, and the total volume and number of coronoid fragments were measured. The coronoid process edge was classified into different anatomical regions, and each region was assigned a number to quantify the distribution of fracture lines. At the last follow-up, the range of motion, visual analog scale, Mayo Elbow Performance Score, complications and reoperations were recorded.

RESULTS

The 92 patients enrolled had an average age of 42 ± 15 years and a male-to-female ratio of 66:26. The median total volume in PLRI patients was less than that in VPMRI patients [431 (132, 818) mm3 vs. 1125 (746, 1421) mm3, adjusted P < .001] and OFD patients [431 (132, 818) mm3 vs. 2565 (381, 4076) mm3, adjusted P = .001]. The median number of coronoid fragments in PLRI patients was also less than that in VPMRI patients [1 (1, 2) vs. 2 (1, 3), adjusted P = .043]. Most of the PCFL-Rs (79%) were located around the volar edge of the lesser sigmoid notch. Compared with that of PLRI, the PCFL-Us of the VPMRI and OFD tended to be located on the more ulnodorsal side of the coronoid process edge. The median ROM [110 (90, 133), P = .001] and the median Mayo Elbow Performance Score [85 (68, 95), P = .038] of patients with OFD were significantly less than those of patients with the other 2 patterns. The incidence of elbow stiffness (56%, 5/9, P = .001) and implant-related irritation (44%, 4/9, P < .001) in the OFD group was significantly higher than that in the other 2 groups.

CONCLUSION

Coronoid fractures differ significantly in fragment volume, comminution severity, and fracture line distribution among different elbow injury patterns. OFD has the worst functional outcomes among complex elbow injury patterns.

Medial elbow approaches for coronoid fractures: risk to the ulnar nerve

Background

Coronoid fractures often require open reduction internal fixation (ORIF) to restore elbow stability. The flexor pronator split, flexor carpi ulnaris (FCU) split, and Taylor and Scham (T&S) approaches are frequently used medial approaches to access the coronoid. The ulnar nerve can be released or transposed when performing these exposures. The optimal medial surgical approach and management of the ulnar nerve has not been clearly defined. The purpose of this study was to compare postoperative ulnar nerve complications in coronoid fractures undergoing ORIF following a medial surgical approach and ulnar nerve release or transposition.

Methods

A retrospective review of 91 patients with coronoid fractures treated with ORIF using a medial approach from 2004 to 2022 was performed at three academic medical centers. Patients ≥ 18 years of age who sustained coronoid fractures with or without associated injuries were included. Patient charts and perioperative imaging were reviewed. Patient demographics, fracture classification, associated injuries, surgical approaches, ulnar nerve management, and postoperative complications were recorded. Primary outcomes assessed were signs and symptoms of postoperative ulnar nerve neuropathy.

Results

The mean age of the cohort was 45 ± 16 years, 71% were males, with a mean length of follow-up of 16 ± 22 months. Of the 91 coronoid fractures, 69 were anteromedials, eight were tips, and 14 were basal types. The incidence of preoperative ulnar neuropathy was 5% (n = 5). The incidence of postoperative ulnar neuropathy was 33% (n = 30) of which 55% (n = 16) completely resolved by final follow-up. The rate of postoperative ulnar neuropathy was not significantly different between in situ release 30% (n = 9) or transposition of the ulnar nerve 34% (n = 20), (P = .64). There was a significantly higher rate of postoperative resolution with transposition (70%) versus in situ release (22%), (P = .045). The rate of postoperative ulnar neuropathy was not significantly different between the FCU, T&S, or flexor pronator split approaches, (P = .331). Finally, the rate of neuropathy resolution was not significantly different between medial approaches (P = .46).

Conclusion

There was no statistical difference in the incidence of postoperative ulnar nerve complications with ulnar nerve transposition or in situ release following coronoid fixation. However, transposing the nerve resulted in a higher rate of neuropathy resolution. While the incidence of postoperative ulnar nerve dysfunction is high following coronoid fixation when using a medial surgical approach, it was similar with the FCU, T&S, and flexor pronator split approaches. Larger cohorts and randomized clinical trials are needed to confirm these findings.

Internal brace augmentation in elbow varus posteromedial rotatory instability (VPMRI) allows early rehabilitation and prevents stiffness

PURPOSE

Varus posteromedial rotatory instability (VPMRI) involves anteromedial coronoid fracture (AMCF), lateral ulnar collateral ligament (LUCL), and medial collateral ligament (MCL) injury. There is no general consensus regarding the surgical treatment, but most surgeons recommend internal fixation of the coronoid along with primary ligament repair. This methodology involves postoperative immobilization to allow ligament healing, occasionally associated with stiffness. Augmentation of one/or both collateral ligaments using a non-absorbable suture tape as an internal brace in VPMRI cases was the subject of the presented study. This method allows brace-free initiation of full elbow range of motion while protecting bony and soft tissue healing.

METHODS

17 patients (13 males and four females) with VPMRI were treated in the center from 2017 to 2021 with internal brace augmentation of collateral ligament along with ORIF (Open reduction & internal fixation)/ reconstruction of the coronoid fragment. All patients were actively mobilized early after surgery. Patients who completed a minimum follow up of 24 months were included in the study. Clinical examination findings at follow-up assessment included ROM (range of motion) recording and instability testing, including special instability tests such as moving valgus stress test, lateral pivot shift test, Posterolateral rotatory drawer test, and gravity-assisted varus stress test. Disabilities of arm, shoulder and hand (DASH) score, Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), Visual Analogue Score (VAS), and SEV (Simple Elbow values) were assessed and noted at follow-up.

RESULTS

At 43 months of mean follow-up, none of the patients had significant postoperative contracture, and none had any clinically apparent signs of instability or suffered subluxation or re-dislocation. Postoperative radiographs showed complete fracture/graft healing with no signs of subluxation in all patients. The mean range of motion of the patients was 6.20 (1.00-11.30) to 139.10 (136.20-142.00), with a mean Oxford elbow score (OES) of 42.0 (39.9-44.7). The mean DASH (Disability of Arm, Shoulder & Hand) score was 11.4 (6.7-16.1), the mean MEPS (Mayo Elbow Performance Score) was 91.2 (86.3-96.0), the mean Visual Analogue Score (VAS) score was 0.6 (0.1-1.2), and the mean Simple Elbow value (SEV) was 85.4% (81.1-89.8%).

CONCLUSION

Internal brace augmentation with a non-absorbable suture tape in the setting of VPMRI is a safe and helpful adjunct to coronoid repair/reconstruction and primary ligament repair and allows early mobilization and recovery of elbow stability and range of motion.

Outcomes and complications after treatment for anteromedial facet fracture of the coronoid process: A systematic review

BACKGROUND

Fracture of the anteromedial facet (AMF) of the coronoid process is associated with varus posteromedial rotatory instability (VPMRI). However, there is still controversy regarding the optimal treatment for AMF fracture. The purpose of this study is to report on a systematic review of the outcomes and complications after treatment for AMF fracture.

METHODS

This study was conducted using electronic databases, PubMed, EMBASE and Scopus. Studies reporting outcome scores and complications were included. Studies that did not utilize O'Driscoll classification for AMF fractures were excluded. Through conduct of a thorough review of included studies, definite VPMRI were identified and cases involving other injury mechanisms were excluded.

RESULTS

Fifteen articles reporting on 246 patients were included. According to O'Driscoll classification, 6.2% of cases were anteromedial subtype I, 73.7% were subtype II, and 20.1% were subtype III. Two-hundred sixteen patients (87.8%) were treated surgically and 30 patients (12.2%) were treated conservatively. Lateral collateral ligament (LCL) injuries were 76.2% (157/206) and medial collateral ligament injuries were 16.9% (33/195). Among 216 cases who underwent surgical treatment, depending on the fragment size, displacement, and instability, coronoid fixation was performed in 189 cases and LCL repair alone was performed in 27 cases. The mean final Mayo Elbow Performance Score was 92.1 and the Broberg & Morrey score was 89.5. The overall complication and reoperation rates were 17.7% (41/232) and 12.9% (26/202).

CONCLUSIONS

Both surgical and conservative treatment for AMF fractures resulted in satisfactory final clinical outcomes. However, high complication and reoperation rates were observed.

Coronoid height index: a reliable and reproducible technique for quantifying coronoid bone loss in elbow instability

Background

Coronoid fracture size is one important factor in decision-making on surgical vs. nonsurgical management. There is currently no reliable, standardized technique to measure coronoid fracture size or bone loss. Hence, decision-making remains arbitrary, and recommendations made in the literature are unreliable. The aim of the study was to develop and assess a simple, reliable computed tomography (CT)-based technique that allows measurement of apical and anteromedial facet (AMF) coronoid height and bone loss. To achieve this, we sought to understand normal coronoid height across a large patient cohort, and whether the new technique was sensitive at detecting bone loss in patients with a fracture.

Methods

163 CT scans were manually formatted in the plane of the proximal ulna. A best fit circle was drawn in the greater sigmoid notch on the sagittal section. The coronoid coverage height (CCH) was defined as the distance (in mm) measured at 90° from the greater sigmoid notch floor to a line between the olecranon and coronoid tips (or fracture base in fractured coronoids), bisecting the center of the circle. The coronoid height index (CHI) was calculated as a % by dividing the CCH by the diameter of the circle. The measurements were performed at the coronoid apex and the center of the AMF in 108 intact coronoids to understand normative values and 55 fractured coronoids to assess the sensitivity of the technique at detecting bone loss. Measurements were independently performed by two investigators, and interobserver reliability was assessed with weighted Cohen's kappa (ĸ) and intraclass correlation coefficient.

Results

For intact coronoids, the mean CCH was 11.4 ± 1.4 mm at the apex and 11.6 ± 1.3 mm at the AMF. The mean CHI was 56.7 ± 4.9% at the apex and 41.1 ± 3.6% at the AMF. For fractured coronoids, the mean CCH and CHI were significantly lower (P < .001) at both the apical (9.7 ± 1.4 mm, 45.8% ± 6.5%) and AMF (9.8 ± 1.6 mm, 33.9% ± 6.5%) positions, confirming that the technique was capable of detecting coronoid bone loss. While the CCH (a metric measurement) was significantly higher in men than in women (P < .001), the CHI (a proportion) demonstrated no significant difference at both the apex (P = .06) and AMF (P = .91). Interobserver reliability was good to excellent across all parameters.

Conclusion

CHI is a reliable CT-based technique to assess coronoid height and bone loss that is independent of patient size and can be used for clinical and research purposes.

Pure varus posteromedial rotatory instability of the elbow: Radiographic findings, treatment, and outcomes

INTRODUCTION

Although varus posteromedial rotatory instability (VPMRI) is a subtle elbow injury that involves anteromedial coronoid facet (AMCF) fracture and ligamentous injuries, treatment options and outcomes of VPMRI remains controversial. The aim of this study was to investigate radiographic findings, treatments, and outcomes of a large series of VPMRI.

METHODS

We retrospectively reviewed 91 pure VPMRI cases with AMCF fracture (O'Driscoll classification anteromedial type) which were treated at 6 hospitals. Clinical and radiographic outcomes were investigated with a mean follow-up period of 46.8 months using the Mayo elbow performance score (MEPS), and the Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH) score, and serial plain radiographs.

RESULTS

In AMCF fracture, there were 4 cases of subtype 1, 67 cases of subtype 2, and 20 cases of subtype 3. On MRI, complete tears of lateral collateral ligament and medial collateral ligament were observed in 83.1 % (59/71 cases) and 33.8 % (24/71 cases). Operative treatment was performed in 68 cases (74.7 %) including both side fixation in 40 cases (58.8 %), medial side fixation only in 17 cases (25.0 %), and lateral side fixation only in 11 cases (16.2 %). Nonoperative treatment was performed in 23 cases (25.3 %). The mean final MEPS and Quick-DASH scores were 93.7 and 7.9. The overall complication and reoperation rates were 22.0 % and 15.4 %. No significant differences regarding final clinical scores and range of motions were observed between the operative group and the nonoperative group, but significant differences were observed regarding number (p = 0.019) and displacement (p = 0.002) of coronoid fragment, and complication rate (p < 0.001) between the two groups.

CONCLUSION

Depending on the pattern of coronoid fragment and the degree of ligamentous injuries, operative treatment of unstable VPMRI using various fixation techniques including coronoid fixation and ligament repair yielded satisfactory final clinical outcomes. However, surgeons should be aware of the high complication and reoperation rates after operative treatment. Stable VPMRI with AMCF fracture involving minimal displacement or small number of fragments can be treated nonoperatively.

A Feasibility Study on Using Hanging Arm Test to Assess Elbow Stability During Surgical Treatment for Varus Posteromedial Rotatory Instability

Objectives

The aim of this study to investigate the safety and effectiveness of performing the hanging arm test during surgical treatment for elbow varus posteromedial rotatory instability (VPMRI) to assess elbow stability and determine whether to repair the lateral ulnar collateral ligament (LUCL).

Methods

In a retrospective study from August 2014 to March 2019, 27 patients with VPMRI who had a negative result in the hanging arm test after fixation of coronoid fracture were selected. Intraoperative bleeding, operative time, elbow range of motion (ROM), and complications were recorded. Elbow function was evaluated with the Mayo elbow performance score (MEPS) and the disabilities of the arm, shoulder, and hand (DASH) score.

Results

The operation time was 85.9 ± 11.06 min (range 65-110). The intraoperative blood loss was 70.7 ± 9.31 ml (range 60-100). At the last follow-up, the elbow joint averaged 73.8° ± 2.931° in pronation, 78.9° ± 2.941° in supination, 7.2° ± 3.207° in extension, and 123.3° ± 6.651° in flexion. The MEPS score was 90.7 ± 4.36 (range 74-95), and the DASH score was 9.8 ± 2.58 (range 6.67-13.3). One patient presented with symptoms of ulnar nerve entrapment 2 months after operation and was treated with ulnar nerve release. The symptom of numbness went away completely 1 week after operation. No complications such as wound infection, arthritis, or chronic instability of the elbow were found in the other patients.

Conclusion

Our findings suggest that not all VPMRI patients need the LUCL to be repaired, and the hanging arm test is a safe and reliable method to assess whether to repair the LUCL in the treatment of elbow VPMRI.

Level of evidence

Level IV; Retrospective studies.

Considerable variation in current coronoid height and fracture measurement techniques: a systematic review

BACKGROUND

Coronoid fractures usually occur in the presence of a significant osseoligamentous injury to the elbow. Fracture size and location correlate with degree of instability and many authors have attempted to analyze the effect of fracture variation on decision making and outcome. There remains no standardized technique for measuring coronoid height or fracture size. The aim of this study was to appraise the literature regarding techniques for coronoid height measurement in order to understand variation.

METHODS

Preferred Reporting Items of Systematic Reviews and Meta-Analyses guidelines were followed. A search was performed to identify studies with either a description of coronoid height, fracture size, or bone loss using the terms (Coronoid) AND (Measurement) OR (Size) OR (Height). Articles were shortlisted by screening for topic relevance based on title, abstract and, if required, full-text review. Exclusion criteria were non-English articles, those on nonhuman species or parts other than the ulna coronoid process, and studies that included patients with pre-existing elbow pathology. Shortlisted articles were grouped based on study type, imaging modality, measurement technique, and measurement parameter as well as its location along the coronoid.

RESULTS

Thirty out of the initially identified 494 articles met the inclusion criteria. Twenty-one articles were clinical studies, 8 were cadaveric studies, and 1 combined patients as well as cadavers. A variety of imaging modalities (plain radiographs, 2-dimensional computed tomography [CT], 3-dimensional CT, magnetic resonance imaging or a combination of these) were used with CT scan (either 2-dimensional images or 3-dimensional reconstructions or both) being the most common modality used by 21 studies. Measurement technique also varied from uniplanar linear measurements in 15 studies to multiplanar area and volumetric measurements in 6 studies to techniques describing various angles and indices as an indirect measure of coronoid height in 8 studies. Across the 30 shortlisted studies, 19 different measurement techniques were identified. Fifteen studies measured normal coronoid height while the other 15 measured intact coronoid and/or fracture fragment height. The location of this measurement was also variable between studies with measurements at the apex of the coronoid in 24/30 (80%) of studies. Measurement accuracy was assessed by only 1 study. A total of 12/30 (40%) studies reported on the interobserver and intraobserver reliability of their measurement technique.

CONCLUSION

The systemic review demonstrated considerable variability between studies that report coronoid height or fracture size measurements. This variability makes comparison of coronoid height or fracture measurements and recommendations based on these between studies unreliable. There is need for development of a consistent, easy to use, and reproducible technique for coronoid height and bone loss.

"How the Wrightington classification of traumatic elbow instability can simplify the algorithm for treatment"

There are numerous injury patterns of elbow-fracture dislocation that can lead to confusion about the best surgical management. The Wrightington classification aims to provide a simple categorization based on the injury to the coronoid process and the three column concept of the elbow osseous stability that describes a medial column consisting of the anteromedial coronoid facet and sublime tubercle, the middlecolumn is the anterolateral coronoid facet, and the lateral column is the radial head and lateral ligament complex with a fulcrum for varus/valgus stability between the two coronoid facets. Injuries are classified as type A (anteromedial facet/medial-column), B (bifacet/ medial and middle-columns), B+ (bifacet with radial head/all three columns), C (combined radial head and anterolateral facet/middle and lateral-columns), D (distal to coronoid where coronoid is in continuity with olecranon process), and D+ (distal to coronoid with radial head fracture). With each bony injury pattern, we can anticipate which soft tissue constraints are likely to be involved and the importance of their repair to restore stability, and thereby develop algorithms for management. The Wrightington classification has been shown to be reliable and valid. A consecutive series of 60 patients with elbow-fracture dislocation managed according to the surgical algorithms of the Wrightington classification have been reported to have excellent outcomes with a median Mayo Elbow Performance Score of 100 (interquartile 85-100) and flexion/extension arc of movement of 123° (interquartile 101°-130°). In conclusion, the Wrightington classification of elbow-fracture dislocation is a comprehensive, reliable, and valid classification with treatment algorithms that are associated with good functional outcomes.

Coronoid fractures and traumatic elbow instability

The coronoid process is key to concentric elbow alignment. Malalignment can contribute to post-traumatic osteoarthritis. The aim of treatment is to keep the joint aligned while the collateral ligaments and fractures heal. The injury pattern is apparent in the shape and size of the coronoid fracture fragments: (1) coronoid tip fractures associated with terrible triad (TT) injuries; (2) anteromedial facet fractures with posteromedial varus rotational type injuries; and (3) large coronoid base fractures with anterior (trans-) or posterior olecranon fracture dislocations. Each injury pattern is associated with specific ligamentous injuries and fracture characteristics useful in planning treatment. The tip fractures associated with TT injuries are repaired with suture fixation or screw fixation in addition to repair or replacement of the radial head fracture and reattachment of the lateral collateral ligament origin. Anteromedial facet fractures are usually repaired with a medial buttress plate. If the elbow is concentrically located on computed tomography and the patient can avoid varus stress for a month, TT and anteromedial facet injuries can be treated nonoperatively. Base fractures are associated with olecranon fractures and can usually be fixed with screws through the posterior plate or with an additional medial plate. If the surgery makes elbow subluxation or dislocation unlikely, and the fracture fixation is secure, elbow motion and stretching can commence within a week when the patient is comfortable.

Conservative versus surgical management of isolated O'Driscoll II coronoid fracture: A systematic review

PURPOSE

The purpose of this systematic review is to summarize the current literature on conservative and surgical management of isolated O'Driscoll II coronoid fracture.

STUDY DESIGN

Systematic review.

METHODS

We systematically searched Medline, Embase, Google Scholar, and Web of Science databases for published studies by complying with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and using the keywords "isolated coronoid fracture," "O'Driscoll type 2 coronoid fracture," "anteromedial coronoid fracture," "anteromedial facet coronoid fracture," "posteromedial rotatory instability," and "varus posteromedial rotatory instability." Patients were divided into conservative treatment and surgical treatment groups. Oxford Centre for Evidence-Based Medicine and Methodological Index for Non-Randomized Studies were assessed to determine each article's quality. The primary outcomes of the present reviews were the Mayo elbow performance score (MEPS) and the disabilities of the arm, shoulder, and hand (DASH) score, and the secondary outcomes were associated with complications and reoperations. Eligible trials were independently chosen by two review authors, and a third reviewer resolved all disagreements.

RESULTS

The search yielded 458 records, among which 446 articles were of relevance, and 12 were included. In the final review, 138 patients were evaluated-98 (71%) who received surgical treatment and 40 (29%) who received conservative treatment. The mean MEPS score and the DASH score of surgical treatment were 91 and 8, respectively; 69.8% of patients had excellent scores, and 27.0% had good scores. The mean MEPS score and the DASH score of conservative treatment were 92 and 12, respectively; 70.6% of patients had excellent scores, and 23.5% had good scores.

CONCLUSIONS

In select cases, conservative treatment can achieve good results in the treatment of isolated O'Driscoll II coronoid fracture when a stricter indication is followed. However, there is insufficient evidence to recommend the appropriate treatment for a particular fracture subtype, and there is a need for more high-quality randomized controlled trials to determine which treatment is superior.

Anteromedial coronoid facet fractures and associated ligament lesions: A case series

INTRODUCTION

Varus posteromedial rotational injury mechanisms lead to fractures of the coronoids process' anteromedial facet. As these fractures are often unstable, rapid fracture treatment is vital to prevent progressive osteoarthritis.

MATERIALS AND METHODS

Twelve patients with a fracture of the anteromedial facet treated surgically were enrolled in the study. Computed tomography images were used to classify the fractures according to the system by O'Driscoll et al. Clinical follow-up included each patient's medical record, surgical treatment algorithm, all complications encountered during the follow-up period, Disabilities of the arm, shoulder, and hand score, subjective elbow value, and pain.

RESULTS

A total of 8 men (66.7%) and 4 women (33.3%) were treated surgically and followed-up after a mean period of 45 ± 23 months. The mean DASH score was 11.9 ± 12.9 points. One patient complained of transient neuropathy in the innervation area of the ulnar nerve, however, this existed already pre-operatively and resolved after less than three months.

CONCLUSIONS

The presented patient cohort shows that AMF fracture of the coronoid process are unstable lesions according to the bony instability and the frequently ruptured collateral ligament complexes which need to be addressed. The MCL seems to be affected more frequently than previously appreciated.

LEVEL OF EVIDENCE

Level IV; Case Series; Treatment Study.

Coronoid fixation and lateral collateral ligament repair in varus posteromedial rotatory instability of the elbow

Background

Varus posteromedial rotatory instability is a relatively rare elbow injury, that has been infrequently reported in published literature. We intended to evaluate the outcomes of surgical management of this rare injury with anteromedial coronoid fixation, and, in selected patients, lateral ulnar collateral ligament (LUCL) repair.

Methods

Between 2017 and 2020, we identified 12 patients with anteromedial coronoid fractures, and a varus posteromedial rotatory instability, who underwent surgery for fixation of the coronoid fracture, with or without LCL repair. All the included patients were either O'Driscoll subtype 2-2, or subtype 2-3. All the 12 patients were followed up for a minimum of 24 months, and their functional outcomes assessed using the Mayo Elbow Performance Score (MEPS).

Results

The mean MEPS recorded in our study was 92.08, and the mean range of elbow flexion achieved was 124.2°. The mean flexion contracture in our patients was 5.83°. Three of our twelve patients (25%) suffered from elbow stiffness even at final follow-up. The results were graded as Excellent in eight, Good in three, and Fair in one patient.

Conclusion

Coronoid fractures and LUCL disruptions associated with varus posteromedial rotatory instability can be reliably managed by employing a protocol that combines radiographic parameters, as well as intra-operative assessments of stability. While surgical intervention successfully restored stability, there is a learning curve to the management of these injuries and complications are not uncommon, particularly elbow stiffness. Hence, in addition to surgical fixation, emphasis should also be placed on intensive post-operative rehabilitation to improve outcomes.

Results of arthroscopically assisted reduction and fixation of anteromedial facet coronoid fractures at short-term follow-up

BACKGROUND

Varus posteromedial rotatory instability is a typical pattern of elbow injury that involves fracture of the anteromedial facet (AMF) of the coronoid, as well as injuries to the lateral ligament complex and the posterior bundle of the medial collateral ligament. Some authors support the idea that subtype II AMF coronoid fractures require fixation to restore elbow stability, but this topic is still an issue in the literature. The purpose of this study was to assess the clinical and radiologic outcomes of arthroscopically assisted reduction and internal fixation (ARIF) of AMF fractures.

METHODS

This retrospective single-center trial evaluated consecutive patients who underwent ARIF of isolated subtype II AMF coronoid fractures between 2014 and 2020. At the final follow-up, the patients were examined for elbow range of motion, stability, and pain. Injury and post-treatment radiographs were reviewed to assess fracture healing and heterotopic ossification.

RESULTS

A total of 32 patients (21 male and 11 female patients) with a median age of 47 ± 16 years were included. The average follow-up period was 28 ± 12.4 months. Coronoid process fractures were fixed by cannulated screws in 26 cases (81.25%); in 2 of these cases, additional Kirschner wires were used. Two Kirschner wires were used in 1 case (3.12%), and in the remaining 5 cases (15.62%), osteosuture was used. The lateral ulnar collateral ligament was injured in 27 cases (84.4%) and was always repaired. Other associated lesions were medial collateral ligament injury, osteochondral lesion, and radial head fracture. There were no surgical complications. At the final follow-up, the average Mayo Elbow Performance Score was 98.4 ± 2.7 and the mean Oxford Elbow Score was 47.3 ± 1.4. No cases of nonunion were detected on radiographic assessment.

CONCLUSIONS

Although technically demanding, ARIF has several potential advantages in comparison to open surgery: less scarring, a decreased risk of infection, and less postoperative pain.

Classification of coronoid process fractures: A pending question

Ulna coronoid fracture is a complicated elbow injury. Comprehensive classification of coronoid fracture can assist diagnosis, guide treatment, and improve prognosis. Existing coronoid fracture classifications are insufficient to interpret all fracture patterns. The coronoid fracture classification is associated with elbow-specific trauma patterns. Coronoid fractures are often associated with other elbow injuries, commonly with radial head fractures, which makes the clinical strategies inconsistent and prognosis poor. The current fracture classifications do not contain information about combined injuries. Preservation of ulnohumeral joint contact after trauma is critical to elbow mechanical and kinematic stability. Important fracture types for treatment include terrible-triad injuries and anteromedial facet fractures. Open reduction and internal fixation of these two fractures should be conducted when marked displacement of the fragment, elbow instability under stress, and complicated associated injuries. The current surgical tactics based on classifications are still controversial.

The radiological findings in complex elbow fracture-dislocation injuries

Elbow fracture-dislocation is a complex injury which can lead to significant bony and soft tissue damage. Surgical intervention is guided towards restoring joint stability, allowing early mobilization and preventing long-term joint stiffness. The most common types are posterolateral, posteromedial, Monteggia type (and variants), and anterior trans-olecranon fracture-dislocations. Posterolateral fracture-dislocation is characterized by a radial head fracture (± anterolateral coronoid fracture) and typically capsuloligamentous disruption (lateral collateral ligaments injury is the most common). A posterolateral fracture-dislocation with radial head and coronoid anterolateral facet fractures is termed a terrible triad injury. In posteromedial fracture-dislocation, there is a fracture of the anteromedial facet of the coronoid, typically with proximal avulsion of the lateral collateral ligaments (± injury to the posterior bundle of the ulnar collateral ligament). Monteggia fracture-dislocation injuries demonstrate proximal ulnar fracture (with possible involvement of the olecranon and the coronoid) and radial head dislocation. These can be divided into apex anterior or apex posterior variants. The latter are commonly associated with radial head fractures and lateral ligamentous injury, and have a worse prognosis. In trans-olecranon fracture-dislocation, there is significant disruption of the greater sigmoid notch and the olecranon, with various involvement of the coronoid and the proximal ulna. The article describes the radiological findings and outlines the management principles in complex elbow fracture-dislocation injuries.

Repair Versus Non-Repair of Lateral Ulnar Collateral Ligament in Elbow Varus Posteromedial Rotatory Instability Treatment: A Comparative Study

OBJECTIVE

To compare the effects of repairing and not repairing the lateral ulnar collateral ligament (LUCL) when surgically treating elbow varus posteromedial rotatory instability (PMRI).

METHODS

In this retrospective study spanning June 2014 to February 2019, 24 patients with elbow PMRI who were treated surgically were assigned to group RL (Repair LUCL) or group NL (Non-repair LUCL) depending on whether the LUCL was repaired. Hospitalization time, operation time, intraoperative blood loss, and related complications were reviewed. The elbow range of motion (ROM), the visual analog scale (VAS), the Mayo elbow performance score (MEPS), and the disabilities of the arm, shoulder, and hand (DASH) score were used for functional assessment.

RESULTS

Among the 24 patients with PMRI, 15 were assigned to group RL and nine were assigned to group NL. The mean blood loss (184.66 ± 20.3 vs 207.33 ± 19.447, P < 0.001), the operation time (98.88 ± 12.693 min vs 184.66 ± 20.3 min, P < 0.001) were significantly lower in group RL compared to group NL. There were no significant differences between the two groups in time until surgery and follow-up time (6.66 ± 1.838 vs 6.11 ± 1.900 days, 25.53 ± 2.099 vs 26.11 ± 2.891 months, P = 0.577, P = 0.486). All of the patients achieved bone union. The elbow flexion-extension ROM (122.00° ± 3.162°vs 121.11° ± 3.333° at 12 months, P = 0.520) and pronation-supination ROM (154.53° ± 3.335° vs 155.55° ± 4.639° at 12 months, P = 0.537). Both groups achieved similar results in MEPS score (90.53 ± 2.695 vs 89.77 ± 3.865, P = 0.578) and DASH (9.77 ± 1.897 vs 9.99 ± 1.550, P = 0.772) score at the final follow-up. And the MEPS score revealed excellent results (87% in group RL, 89% in group NL).The VAS scores decreased significantly in group RL (from 6.13 ± 0.990 to 1.93 ± 0.593) and group NL (from 5.77 ± 1.481 to 1.88 ± 0.781), and no significant differences in preoperative or final follow-up were observed between the two groups (P = 0.487, P = 0.876). Complications observed in group NL with one patient occurred cubital tunnel syndrome 3 months after the operation, the patient underwent ulnar nerve simple neurolysis and the symptoms were relieved after 3 weeks.

CONCLUSION

For patients with elbow PMRI, satisfactory functional outcomes can be yielded with non-repair of the LUCL as long as the stable elbow joint is performed during operation.

Dislocations of the elbow - An instructional review

Dislocations of the elbow require recognition of the injury pattern followed by adequate treatment to allow early mobilisation. Not every injury requires surgery but if surgery is undertaken all structures providing stability should be addressed, including fractures, medial and lateral ligament insertion and the radial head. The current concepts of biomechanical modelling are addressed and surgical implications discussed.

The three-column concept of elbow joint stability and the Wrightington elbow fracture-dislocation classification, emphasizing the role of cross-sectional imaging

Elbow fracture-dislocation is a complex injury with a combination of osseous and soft tissue disruption. Different classification systems have been used to describe the injury pattern and help guide the management. The article describes the important cross-sectional findings in complex elbow fracture-dislocation injuries based on the relatively new Wrightington classification. This includes the various elements and patterns seen in elbow fracture-dislocations providing a simple and comprehensive system to classify these injuries and help guide the surgical management. The article also describes the three-column concept of elbow joint stability, dividing the elbow joint osseous structures into lateral, middle and medial columns. Detailed radiological assessment of the fractures pattern is vital to understand the mechanism of injury, allowing clinicians to predict the associated capsuloligamentous injury and help guide the management decisions. The Wrightington elbow fracture-dislocation classification categorizes the injuries according to the ulnar coronoid process and radial head fractures. Type A is an anteromedial coronoid fracture. Type B is a bifacet or basal coronoid fracture, with B + indicating associated radial head fracture. Type C is a combined anterolateral facet and radial head or comminuted radial head fractures. Type D is a diaphyseal ulnar fracture, with D + indicating associated radial head fracture.

Clinical comparison of the over-the-top and flexor carpi ulnaris split approaches for the treatment of anteromedial facet fracture of the coronoid process

BACKGROUND

The flexor carpi ulnaris (FCU)-split approach and the over-the-top approach have been used frequently for the fixation of anteromedial facet (AMF) fractures of the coronoid process. Clinical studies have not compared functional recovery and complication rates associated with these approaches. This study aimed to compare the clinical effectiveness of the over-the-top and FCU-split approaches for the treatment of AMF fractures of the coronoid process.

METHODS

Thirty-two patients who underwent surgery for AMF fractures between January 2013 and August 2019 were divided into the FCU-split and over-the-top groups. The FCU-split approach was used from January 2013 to March 2016, and the over-the-top approach was used from April 2016 to August 2019. Bony union, radiographic signs of osteoarthritis (Broberg and Morrey classification), and development of heterotopic ossification were evaluated. Postoperative pain score (visual analog scale at 2 days after the operation), surgical time (minutes), range of motion of the elbow, elbow function (Mayo Elbow Performance Score [MEPS]), and the presence of postoperative ulnar neuropathy were also compared between the 2 groups.

RESULTS

The FCU-split and over-the-top approaches were performed in 15 and 17 patients, respectively. The mean age was 46 ± 13 years (range, 22-67 years), and the mean follow-up duration was 19± 6.7 months (range, 13-38 months). All coronoid fractures had a solid osseous union during the follow-up, and no subluxation or dislocation was observed in the 2 groups. The occurrence of heterotopic ossification and the grade of post-traumatic arthritis did not differ significantly between the groups (all P > .05). There were also no significant differences between the groups in terms of postoperative pain score, range of motion, and MEPS (all P > .05). However, the surgical time was shorter for the over-the-top approach than that for the FCU-split approach (79± 23 vs. 101 ± 14, P = .008), and the surgical time was significantly associated with the fracture classification and surgical approach (P = .001 and .003, respectively). In addition, postoperative ulnar neuropathy occurred less with the over-the-top approach than with the FCU-spilt approach (5.9% vs. 46%, P = .013).

CONCLUSION

Both the FCU-split and over-the-top approaches were appropriate for performing the buttress plate fixation for AMF fractures of the coronoid process and for restoring the elbow stability. The fixation of AMF fractures through the over-the-top approach was technically easier and had less incidence of postoperative ulnar neuropathy.

Morphological characteristics of fractures of the anteromedial facet of the coronoid in posteromedial rotatory instability of the elbow: a three-dimensional CT remodeling study

BACKGROUND

Fractures of the anteromedial facet of the coronoid in posteromedial rotatory instability of the elbow are classified into 3 subtypes based on their location. The purpose of this study was to analyze the fracture morphology of anteromedial facet fractures in their 3 subtypes (anteromedial rim, anteromedial rim + tip, and anteromedial rim + sublime tubercle [±tip]).

METHODS

Three-dimensional computed tomography remodeling was used to evaluate anteromedial facet fractures in a consecutive series of 40 patients, all of whom were affected by posteromedial rotatory instability of the elbow. Characteristics of the fractures, including the number of fragments, size of fragments, plane of the fracture line, and involvement of the sublime tubercle and radial notch, were measured for each subtype of the anteromedial facet fractures.

RESULTS

Each subtype had a typical fracture pattern and distinct size. The fracture subtype 1 showed a single-fragment fracture, subtype 2 showed either a single- or dual-fragment fracture, and subtype 3 showed either a dual- or triple-fragment fracture. The angle between the fracture line and the coronal plane was greatest in subtype 3 fractures. The surface area of the fragment was largest in subtype 3 fractures. The percentages of articular involvement of the sublime tubercle were 0% in subtype 1, 47% in subtype 2, and 79% in subtype 3. The percentages of articular involvement of the radial notch were 0% in subtype 1, 7% in subtype 2, and 8% in subtype 3.

CONCLUSION

Analysis with quantitative 3-dimensional computed tomography showed the characteristic morphology of each subtype of anteromedial facet fracture. Subtype 1 comprised 1 fragment with the smallest fragment size. Subtype 2 was a single- or dual-fragment fracture, the size of which should be considered in the treatment plan. Subtype 3 was a large fragment comprising the sublime tubercle. Our findings are significant because they highlight unique fracture morphology that may help surgeons to distinguish one fracture subtype from another in clinical practice.

Posteromedial rotatory instability of the elbow: What the radiologist needs to know

Varus posteromedial rotatory instability of the elbow joint is a relatively new subject described for the first time in 2003. It occurs secondary to axial loading of the elbow with varus force and internal rotation of the forearm. There is usually a specific pattern of osseous and soft tissue injuries that can be recognized on imaging. This includes an anteromedial coronoid fracture and avulsion of the lateral collateral ligament complex from its humeral attachment. Ulnar collateral ligament complex injury is also reported, particularly its posterior bundle which plays an important role in posteromedial elbow joint stability. There is high incidence of early osteoarthritis secondary to the resultant varus instability and increased contact pressure at the ulnohumeral joint. Surgical fixation of the coronoid fracture and ligamentous reconstruction maybe indicated to prevent this recurrent instability. The article reviews the key radiological features of posteromedial rotatory instability with multiple examples from different imaging modalities. The relevant anatomy of the elbow joint stabilising structures will be illustrated, in particular the coronoid process anatomy and the O'Driscoll classification for coronoid process fractures. Radiologists should be familiar with the imaging findings of posteromedial rotatory instability.

Management of anteromedial coronoid fractures according to a protocol focused on instability assessment provides good outcomes with infrequent need for coronoid fixation

BACKGROUND

Anteromedial coronoid fractures (AMCFs) are associated with persistent elbow instability and post-traumatic arthritis if managed incorrectly. It is unclear exactly which AMCFs require surgical intervention and how to make this decision. The aims of this study were to report outcomes of AMCFs managed using a protocol based on reproduction of instability using radiographic and clinical testing and to ascertain a threshold size of AMCF associated with instability.

METHODS

Forty-three AMCFs were studied. Thirty-two patients formed the primary study group (group A). All were treated using a protocol in which the decision to perform coronoid fixation was based on the presence of radiographic or clinical evidence of instability. Functional outcomes (Oxford Elbow Score), radiographic outcomes, complications, and reoperations were collected, and a receiver operating characteristic curve analysis was performed to assess the optimal coronoid fracture height to recommend coronoid fixation. The results were compared with a historical group of 11 patients with AMCFs not treated according to the protocol (group B).

RESULTS

Of the patients, 23 had an isolated AMCF and 20 had a concurrent radial head injury. Complete nonoperative treatment of the elbow was performed in 16 patients (37%) (11 of 32 [34%] in group A vs. 5 of 11 [45%] in group B, P = .46). In 10 patients (23%), only repair of the lateral collateral ligament was performed (9 in group A and 1 in group B), whereas 8 patients (19%) underwent repair of the lateral collateral ligament and radial head fixation or replacement (6 in group A and 2 in group B). Acute coronoid fixation was performed in 9 patients (21%) (6 in group A and 3 in group B). At a mean follow-up of 20 months (range, 12-56 months), group A showed a significantly better Oxford Elbow Score (42 vs. 31, P = .02), lower complication rate (3 of 32 [9%] vs. 8 of 11 [72%], P < .001), and lower reoperation rate (1 of 32 [3%] vs. 6 of 11 [54%], P < .001) than group B. Persistent instability was found in 6 patients in group B and none in group A. The receiver operating characteristic curve analysis demonstrated 6.5 mm to be the optimal AMCF size for surgery to prevent persistent instability.

CONCLUSION

Patients treated according to a protocol in which preoperative reproduction of instability determined the degree of surgical intervention had good clinical and radiographic outcomes. Our study demonstrated that AMCFs > 6.5 mm are likely to be more unstable and require intervention. If these principles are followed, a specifically defined subset of AMCFs can be treated nonsurgically without adverse outcomes.

The treatment of anteromedial coronoid facet fractures: a systematic review

BACKGROUND

Fractures of the anteromedial facet (AMF) of the coronoid process are caused by a varus posteromedial rotational injury force, leading to instability in the ulnohumeral joint. AMF fractures are usually accompanied by avulsion of the lateral ulnar collateral ligament (LUCL). O'Driscoll's description and classification of AMF coronoid fractures has increased awareness and interest in this injury, but the optimal treatment has yet to be decided.

METHODS

We systematically reviewed the available literature searching electronic databases, MEDLINE using the PubMed interface and Embase. The primary objective was to determine outcome scores but also complication and revision rates depending on the fracture and its therapy in order to gain a more comprehensive picture. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were applied.

RESULTS

Initially, 304 publications were identified. Finally, 10 studies were left for inclusion, all of them retrospective in design, comprising 128 patients; the majority of them were male (75.7%). A total of 114 patients (89.1%) were treated surgically and 14 patients (10.9%) were treated conservatively. Among the surgically treated patients, 70.2% were treated with LUCL refixation. The average Mayo Elbow Performance Score of the surgically treated patients was 91.5 points. The average Mayo Elbow Performance Score of the conservatively treated patients was 91.4 points. A total of 10 patients (7.8%) required reoperation.

CONCLUSION

Surgery of AMF fractures leads to a satisfactory functional outcome in the vast majority of patients independent of the subtype. An algorithm for LUCL fixation is still pending. Conservative treatment may be considered under strict preconditions, especially for nondisplaced subtype 1 and 2 fractures, as these fractures show satisfactory functional outcomes when treated nonoperatively.

Treatment of elbow instability: state of the art

The elbow is a congruent joint with a high degree of inherent stability, provided by osseous and soft-tissue constraints; however, when substantial lesions of these stabilising structures happen, instability of the elbow occurs. Significant improvements in surgical elbow instability diagnosis and treatment have been recently introduced both for acute and chronic cases. Specific stress tests, recently introduced in the clinical practice, and different imaging techniques, both static and dynamic, allow assessment of the elbow stabilisers and detection of the instability direction and mechanism even in subtle forms. Many surgical techniques have been standardised and surgical instruments and devices, specifically dedicated to elbow instability treatment, have been developed. Specific rehabilitation protocols have been designed to protect the healing of the elbow stabilisers while minimising elbow stiffness. However, despite the progress, surgical treatments can be challenging even for expert surgeons and the rate of persistent instability, post-traumatic arthritis, stiffness and pain can be still high especially in most demanding cases. The biology of the soft-tissue healing remains one of the most important aspects for future investigation. If future research will help to understand, correct or modulate the biological response of soft-tissue healing, our confidence in elbow instability management and the reproducibility of our treatment will tremendously improve. In this paper, the state of the art of the current knowledge of elbow instability is presented, specifically focusing on modern surgical techniques used to solve instability, with repair or reconstruction of the damaged elbow stabilisers.

[Treatment of ulnar coronoid process fracture via a modified anteromedial approach]

OBJECTIVE

To investigate the effectiveness of a modified anteromedial approach in the treatment of ulnar coronoid process fracture.

METHODS

Between February 2017 and July 2018, 15 patients with ulna coronoid process fracture were reviewed. There were 9 males and 6 females, with an average age of 42.3 years (range, 24-60 years). The causes of injury included falling in 10 cases and traffic accidents in 5 cases, all cases were closed injury. According to the O'Driscoll classification, there were 4 cases of type Ⅰ, 6 cases of type Ⅱ, and 5 cases of type Ⅲ. The time from injury to operation was 2-8 days (mean, 3.7 days). All fractures were treated via a modified anteromedial approach between the pronator teres and the flexor carpi radialis plus with partial incision of flexor tendon aponeurosis. The fracture healing, muscle strength of forearm, postoperative complications were observed. At last follow-up, the elbow mobility were measured, the function of elbow was evaluated by Mayo elbow performance score (MEPS).

RESULTS

All cases were followed up 10-18 months (mean, 13.3 months). Fracture union was achieved in all patients with a mean time of 10 weeks (range, 8-14 weeks). No obvious decrease of hand grip strength, nerve injury, and infection occurred. One patient had slight heterotopic ossification without special treatment. At last follow-up, all patients had stable elbows with good flexion-extension and varus-valgus stability, the mean flexion was 123.3° (range, 100°-140°), mean extension loss compared with that before operation was 6.7° (range, 0°-20°), mean pronation was 76.0° (range, 60°-85°), and mean supination was 75.8° (range, 55°-90°). The MEPS score was 65-100 (mean, 90.3) with the result of excellent in 10 cases, good in 4 cases, and fair in 1 case.

CONCLUSION

The treatment of ulnar coronoid process fracture via the modified anteromedial approach provides excellent exposure, minimal invasion, fewer complications, and satisfactory prognosis, which is conducive to elbow joint function recovery.

Soft tissue injury patterns in posteromedial rotatory instability with dislocation compared with posteromedial dislocation of the elbow joint

BACKGROUND

We sought to determine injury mechanisms and soft tissue injury patterns of dislocation caused by posteromedial rotatory instability (PMRI) and simple posteromedial (PM) dislocation of the elbow joint that appear similar on simple radiographs.

METHODS

In this retrospective case-series study, we reviewed 13 patients with PMRI dislocation and 10 patients with simple PM dislocation. Three-dimensional computed tomography and magnetic resonance imaging were performed in both groups. The ulnar collateral ligament, lateral collateral ligament complex (LCLC), overlying extensor muscle, and locus of bone contusion were identified. The direction of dislocation was categorized into the pure-posterior or PM type by simple radiographs.

RESULTS

The LCLC was completely ruptured in both groups. A completely torn ulnar collateral ligament was observed in 3 patients (23%) in the PMRI dislocation group and 9 patients (90%) in the simple PM dislocation group (P = .005). Regarding injury patterns of the LCLC and overlying extensor muscle, the distraction type was found in 10 patients (77%) and the stripping type was found in 3 patients (23%) in the PMRI dislocation group, whereas all patients (100%) in the simple PM dislocation group had the distraction type (P = .103). Bone contusion was observed at the posterolateral olecranon in 2 patients (15%) in the PMRI dislocation group and at the PM olecranon in 4 patients (40%), posterolateral olecranon in 1 (10%), posterior olecranon in 1 (10%), and PM-posterolateral olecranon in 1 (10%) in the simple PM dislocation group (P = .008). In the PMRI dislocation group, 7 patients (54%) had the PM type and 6 (46%) had the pure-posterior type.

CONCLUSIONS

Simple PM and PMRI dislocations of the elbow joint might have different soft tissue injury characteristics because of different injury mechanisms.

Functional outcomes after treatments for different types of isolated ulnar coronoid fracture: A protocol for systematic review

BACKGROUND

Optimal treatments for ulnar coronoid fracture have yet to be determined. We aimed to systematically review treatment efficacy assessed by functional outcomes of patients with isolated ulnar coronoid fracture.

METHODS

Medline, Cochrane Library, EMBASE, and Google Scholar were searched for studies reporting quantitative outcomes data after surgical treatment for isolated ulnar coronoid fractures up to July 16, 2019. Functional outcomes determined using disabilities of the arm, shoulder and hand score; Mayo elbow performance score (MEPS); and range of motion were systematically reviewed.

RESULTS

Six studies with a total of 65 patients with isolated coronoid fracture who had received surgical treatment were included. All studies were of good quality according to a modified Delphi checklist. Most patients had Type II fractures based on Regan-Morrey or O'Driscoll classification. Disabilities of the arm, shoulder and hand scores were reported by 2 studies (mean range 5-17). Four studies reported MEPS (mean range 89-98). One study reported Broberg-Morrey scores, in which 93% patients achieved excellent or good outcomes. Five studies reported range of motion, with mean flexion ranging from 122 to 137 and mean extension ranging from 4.0 to 21 degrees. Quantitative analyses revealed that lateral, medial, or posterior approaches in treating Type II fractures are associated with higher postoperative MEPS and flexion scores than the anteromedial approach.

CONCLUSIONS

Treatment efficacy assessed by functional outcomes for isolated ulnar coronoid fractures is overall satisfactory. Whether lateral, medial, or posterior approaches lead to more favorable outcomes than the anteromedial approach is inconclusive. Further prospective studies are warranted.

[Plate osteosynthesis of the coronoid process of the ulna]

OBJECTIVE

The aim of surgical treatment is reconstruction of the coronoid process' bony anatomy.

INDICATIONS

Large shear fractures of the coronoid process (Regan-Morrey type II-III, O'Driscoll "tip" subtype 2 and "basal" subtype 1-2) and fractures of the anteromedial facet (O'Driscoll "anteromedial" subtype 1-3) can occur isolated or as part of the "terrible triad" injuries to the elbow. Due to the resulting instability of these injuries, surgical reconstruction is generally indicated.

CONTRAINDICATIONS

In case of major accompanying soft tissue injuries to the elbow or an elbow infection, primary operative treatment using anatomical plate osteosynthesis is contraindicated.

SURGICAL TECHNIQUE

Plate osteosynthesis of the coronoid process is performed through a medial approach (Hotchkiss or M. flexor carpi ulnaris split). After repositioning of the fracture fragments, a preformed anatomical plate can be fixed to the coronoid process.

POSTOPERATIVE MANAGEMENT

The arm is immobilized in an over-the-elbow cast until the wounds are dried. Afterwards, the elbow should preferably be treated functionally without varus or valgus stress.

RESULTS

Between January 2015 and July 2018, a total of 11 patients underwent osteosynthesis of the coronoid using anatomically preformed plate osteosynthesis. After a mean follow-up of 10.7 months, the mean Mayo Elbow Performance Score showed an excellent result with 78.89 points. The Quick Disabilities of Arm, Shoulder and Hand (Q-DASH) score showed a median of 18.64 points with a mean functional arc of 118°.

Buttress plate fixation of coronoid process fractures via a medial approach

PURPOSE

To assess the clinical and radiographic outcomes of coronoid process fractures surgically managed with buttress plate fixation via a medial approach.

METHODS

A retrospective review of all coronoid fractures surgically fixed in our institution using a buttress plate technique via a medial approach between June 2012 and April 2015 by the senior author was performed. These fractures were all sizeable fractures contributing to persistent elbow instability in terrible triad or varus posteromedial rotatory instability injury patterns. A prospective telephone questionnaire was conducted to assess patient outcomes using the disabilities of the arm, shoulder and hand (DASH) score and Mayo hlbow performance score (MEPS).

RESULTS

Twelve patients were included in the study, comprising 10 males and 2 females with an average age of 39 years (range, 19-72 years). Mean follow-up was 16 months (range, 4-18 months). The average time to radiographic union was 4 months (range, 3-7 months). Range of motion measurements at final follow-up were obtained in 11 out of 12 patients, with one patient defaulting follow-up. All 11 patients displayed a functional elbow range of motion of at least 30°-130°, with an average arc of motion of 130° (range, 110° -140°), mean elbow flexion of 134° (range, 110° -140°) and mean flexion contracture of 3° (range, 0° -20°). The mean DASH score was 16 (range, 2.5-43.8) and the mean MEPS was 75 (range, 65-100). Complications observed included one patient with a superficial wound infection which resolved with a course of oral antibiotics and one patient with radiographic evidence of heterotopic ossification which was conservatively managed. No residual elbow instability was observed and no reoperations were performed.

CONCLUSION

Buttress plate fixation via a medial approach of coronoid process fractures that contribute to persistent elbow instability represents a reliable method of treatment that produces satisfactory and predictable outcomes.

Most coronoid fractures and fracture-dislocations with no radial head involvement can be treated nonsurgically with elbow immobilization

HYPOTHESIS

Conservative treatment of isolated coronoid fractures and fracture-dislocations focused on soft-tissue healing can provide good clinical results in the majority of patients. Our aims were (1) to evaluate the outcome of a conservative treatment protocol designed for isolated coronoid fractures with or without associated elbow dislocations (ICFs) and (2) to characterize the fractures with a dedicated image analysis protocol.

METHODS

Of 38 consecutive patients sustaining acute ICFs, 28 were treated nonsurgically after meeting specific inclusion criteria, prospectively followed up, and clinically evaluated at least 1 year after sustaining their injuries. All cases underwent elbow computed tomography scans with tri-plane and 3-dimensional reconstructions according to a specific protocol referenced to the proximal ulna.

RESULTS

The study included 15 male and 13 female patients, with a mean follow-up period of 32 ± 14 months (range, 12-61 months). An associated dislocation was presented in 8 (29%). Mean extension and flexion were 2° ± 8° (range, -10° to 30°) and 139° ± 11° (range, 110°-155°), respectively. Mean pronation and supination were 74° ± 3° (range, 60°-75°) and 83° ± 9° (range, 40°-85°), respectively. Of the patients, 78% rated their elbow as being normal or nearly normal. The mean Mayo Elbow Performance Score was 95 ± 9 (range, 70-100). The mean Disabilities of the Arm, Shoulder and Hand score was 7 ± 13 (range, 0-57). The mean coronoid fracture height was 5.7 ± 1.2 mm (range, 3.7-7.9 mm). The mean percentage of coronoid height fractured was 33% ± 6% (range, 23%-43%). Mean fracture displacement was 2.7 ± 2 mm (range, 1-9 mm). Of the fractures, 23 (82%) were located at the anteromedial coronoid.

CONCLUSION

An ICF with a perfectly reduced ulnohumeral joint, a competent sublime tubercle, and a fractured coronoid height up to 50% can be treated without surgery with excellent or good results in more than 90% of cases regardless of the location of the fracture in the coronoid or the type of soft tissue-associated disruptions.

Insertional anatomy of the anterior medial collateral ligament on the sublime tubercle of the elbow

BACKGROUND

Acute injuries to the anterior medial collateral ligament (AMCL) can occur due to valgus trauma or during other dislocating events to the elbow. AMCL lesions are often associated with bony lesions, such as radial head fractures or fractures of the coronoid process. We analyzed the insertion of the AMCL on the sublime tubercle in relation to surrounding osseous structures. We aimed to increase the understanding of the involvement of the AMCL in bony lesions to the sublime tubercle.

METHODS

We investigated 86 elbows from 43 embalmed human specimens. We measured the most ventral extensions of the AMCL at the sublime tubercle in relation to a clearly defined and reproducible landmark. We used as our landmark a horizontal line (baseline) originating on the lesser sigmoid notch in a right angle to the ulnar ridge.

RESULTS

The mean distance of the coronoid process tip to the baseline was 4.0 mm (standard deviation [SD], 1.3 mm; range, 1.4-6.7 mm). The mean distance of the ventral extension of the AMCL to the horizontal line was 3.7 mm (SD, 2.6 mm; range: 9.4-2.2 mm). The mean horizontal distance between the ventral aspect of the AMCL and the coronoid tip was 13.7 mm (SD, 2.5 mm; range, 7.7-20.5 mm).

CONCLUSIONS

We present a detailed description of the insertional anatomy of the AMCL at the sublime tubercle. These values could be helpful for classifications of coronoid fractures and to estimate the involvement of the AMCL in fractures of the sublime tubercle.

Posteromedial rotatory incongruity of the elbow: a computational kinematics study

BACKGROUND

Our objective was to analyze the effect of different anteromedial coronoid fracture patterns with different combinations of ligamentous repairs. We hypothesized that smaller fractures would be sufficiently treated with ligamentous repair alone but that larger fragments would require a combination of ligament and bony repair versus reconstruction.

METHODS

Two multibody models were created from cadaveric specimens in the ADAMS program. Four different conditions were simulated: (1) no fracture, (2) O'Driscoll anteromedial subtype I (2.5-mm) fracture, (3) subtype II 2.5-mm fracture, and (4) subtype II 5-mm fracture. In each of these conditions, 3 ligament repairs were studied: lateral ulnar collateral ligament (LUCL), posterior bundle of the medial collateral ligament (pMCL), and both LUCL and pMCL. For each condition, kinematics and articular contact areas were calculated.

RESULTS

LUCL repair alone increases whereas pMCL repair decreases internal rotation of the ulna relative to all tested posteromedial rotatory instability conditions; their rotational effects are summative when both ligaments are repaired. With a subtype I fracture and both pMCL and LUCL injuries, repairing the LUCL alone corrects angulation whereas rotational stability is satisfactory through the arc from 0° to 90°. In a subtype II 2.5-mm fracture, isolated repair of the LUCL or pMCL is not capable of restoring rotation or angulation. For a subtype II 5-mm fracture, no combination of ligamentous repairs could restore rotation or angulation.

CONCLUSIONS

This study suggests that LUCL repair alone is sufficient to restore kinematics for small subtype I fractures for an arc avoiding deep flexion; whereas nearly normal kinematics throughout the arc of motion can be achieved if the pMCL is also repaired. Larger anteromedial coronoid fractures should ideally have fragments fixed in addition to ligament repairs.

Varus Posteromedial Rotatory Instability of the Elbow: Injury Pattern and Surgical Experience of 27 Acute Consecutive Surgical Patients

OBJECTIVES

To identify associated injuries that occur in varus posteromedial rotatory instability (VPMRI) of the elbow and present their surgical management.

DESIGN

Level II retrospective study.

SETTING

Tertiary referral center.

PATIENT/PARTICIPANTS

Twenty-seven patients with VPMRI injuries treated surgically over an 8-year period.

INTERVENTION

Open reduction and internal fixation of anteromedial coronoid facet fracture, lateral collateral ligament repair, and associated injured soft-tissue repairs.

MAIN OUTCOME MEASURED

Radiographic classification, associated medial and lateral bony and soft-tissue injuries, surgical fixation method, and complications were recorded.

RESULTS

According to the O'Driscoll classification, there were 15 (55%) type 2-2, 11 (41%) type 2-3, and 1 (4%) type 3-1 fractures. Lateral and medial collateral ligament tears were found in 100% and 63%, respectively. Common extensor and flexor origin injuries occurred in 19 (70%) and 2 (7%) elbows, respectively. A marginal radial head fracture was found in 1 patient. Most patients were treated with a combination of fixation methods. Complications occurred in 7 (26%) patients.

CONCLUSIONS

This study documents both associated findings and surgical fixation methods. In all cases, the lateral collateral ligament was disrupted, often in association with an injured common extensor origin. Medial collateral ligament injuries are commonly involved. Radial head fractures are rarely associated. The surgeon should have a high index of suspicion if an isolated coronoid fracture is encountered. Clinical and functional outcome scores are needed in future studies to further inform treatment of VPMRI of the elbow.

LEVEL OF EVIDENCE

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

The role of the posterior bundle of the medial collateral ligament in posteromedial rotatory instability of the elbow

Aims

The aim of this study was to evaluate two hypotheses. First, that disruption of posterior bundle of the medial collateral ligament (PMCL) has to occur for the elbow to subluxate in cases of posteromedial rotatory instability (PMRI) and second, that ulnohumeral contact pressures increase after disruption of the PMCL.

Materials and Methods

Six human cadaveric elbows were prepared on a custom-designed apparatus which allowed muscle loading and passive elbow motion under gravitational varus. Joint contact pressures were measured sequentially in the intact elbow (INTACT), followed by an anteromedial subtype two coronoid fracture (COR), a lateral collateral ligament (LCL) tear (COR + LCL), and a PMCL tear (COR + LCL + PMCL).

Results

There was no subluxation or joint incongruity in the INTACT, COR, and COR + LCL specimens. All specimens in the COR + LCL + PMCL group subluxated under gravity-varus loads. The mean articular contact pressure of the COR + LCL group was significantly higher than those in the INTACT and the COR groups. The mean articular contact pressure of the COR + LCL + PMCL group was significantly higher than that of the INTACT group, but not higher than that of the COR + LCL group.

Conclusion

In the presence of an anteromedial fracture and disruption of the LCL, the posterior bundle of the MCL has to be disrupted for gross subluxation of the elbow to occur. However, elevated joint contact pressures are seen after an anteromedial fracture and LCL disruption even in the absence of such subluxation. Cite this article: Bone Joint J 2018;100-B:1060–5.

Anteromedial fractures of the ulnar coronoid process: correlation between surgical outcomes and radiographic findings

BACKGROUND

This study aimed to report the radiographic findings and surgical outcomes of anteromedial facet (AMF) fracture of the ulnar coronoid process and to suggest an optimal approach.

METHODS

In this retrospective study, 20 consecutive patients with unilateral AMF fracture of coronoid process were surgically treated and divided into two groups without (group A) and with (group B) additional proximal ulnar fractures in equal case number. Time from injury to surgery averaged 4.38 ± 2.56 weeks. Mayo Elbow Performance Score (MEPS) and Shortened Disability of the Arm and Shoulder and Hand (quickDASH) score were used for functional evaluation. Cohen kappa coefficient (kappa) analysis was used to determine interobserver reliability on a radiographic reading.

RESULTS

All cases had a mean follow-up of 2.3 years. MEPS at 2 years averaged 87.75 ± 12.51; quickDASH, 7.05 ± 6.19. A significantly higher MEPS was found in subtype 3 than in subtype 2 (p = 0.036) and in group B than in group A (p = 0.020). Significantly lower quickDASH cores were found in group B than in group A (p = 0.011). Kappa analysis showed moderate agreement in the O'Driscoll classification (kappa = 0.56) and substantial agreement in categorization of the additional proximal ulnar fractures (kappa = 0.76).

CONCLUSIONS

Additional proximal ulnar lesions were considered an integral part of varus posteromedial rotatory instability and required further categorization in the management of AMF fractures. Significantly better functional outcomes were achieved when those lesions were fully addressed.

Articular Contact Area and Pressure in Posteromedial Rotatory Instability of the Elbow

BACKGROUND

Joint incongruity in posteromedial rotatory instability (PMRI) has been theorized to determine early articular degenerative changes. Our hypothesis was that the articular contact area and contact pressure differ significantly between an intact elbow and an elbow affected by PMRI.

METHODS

Seven cadaveric elbows were tested under gravity varus stress using a custom-made machine designed to simulate muscle loads and allow passive elbow flexion (0° to 90°). The mean contact area and contact pressure data were collected and processed using the Tekscan sensor and software. After testing the intact specimen (intact elbow), a PMRI injury was simulated (PMRI elbow) and the specimen was tested again.

RESULTS

The PMRI elbows were characterized by initial joint subluxation and significantly elevated articular contact pressure. Both worsened, corresponding with a reduction in contact area, as the elbow was flexed from 0° until the joint subluxation and incongruity spontaneously reduced (at a mean [and standard error] of 60° ± 5° of flexion), at which point the mean contact pressure decreased from 870 ± 50 kPa (pre-reduction) to 440 ± 40 kPa (post-reduction) (p < 0.001) and the mean contact area increased from 80 ± 8 mm to 150 ± 58 mm (p < 0.001). This reduction of the subluxation was also followed by a shift of the contact area from the coronoid fracture edge toward the lower portion of the coronoid. At the flexion angle at which the PMRI elbows reduced, both the contact area and the contact pressure of the intact elbows differed significantly from those of the PMRI elbows, both before and after the elbow reduction (p < 0.001).

CONCLUSIONS

The reduction in contact area and increased contact pressures due to joint subluxation and incongruity could explain the progressive arthritis seen in some elbows affected by PMRI.

CLINICAL RELEVANCE

This biomechanical study suggests that the early degenerative changes associated with PMRI reported in the literature could be subsequent to joint incongruity and an increase in contact pressure between the coronoid fracture surface and the trochlea.

Complex Elbow Dislocations and the "Terrible Triad" Injury

Background:

The elbow is the second most commonly dislocated joint in adults and up to 20% of dislocations are associated with a fracture. These injuries can be categorised into groups according to their mechanism and the structures injured.

Methods:

This review includes a literature search of the current evidence and personal experiences of the authors in managing these injuries.

Results:

All injuries are initially managed with closed reduction of the ulno-humeral joint and splinting before clinical examination and radiological evaluation. Dislocations with radial head fractures should be treated by restoring stability, with treatment choice depending on the type and size of radial head fracture. Terrible triad injuries necessitate operative treatment in almost all cases. Traditionally the LCL, MCL, coronoid and radial head were reconstructed, but there is recent evidence to support repairing of the coronoid and MCL only if the elbow is unstable after reconstruction of lateral structures. Surgical treatment of terrible triad injuries carries a high risk of complications with an average reoperation rate of 22%. Varus posteromedial rotational instability fracture-dislocations have only recently been described as having the potential to cause severe long-term problems. Cadaveric studies have reinforced the need to obtain post-reduction CT scans as the size of the coronoid fragment influences the long-term stability of the elbow. Anterior dislocation with olecranon fracture has the same treatment aims as other complex dislocations with the added need to restore the extensor mechanism.

Conclusion:

Complex elbow dislocations are injuries with significant risk of long-term disability. There are several case-series in the literature but few studies with sufficient patient numbers to provide evidence over level IV.

Role of the lateral collateral ligament in posteromedial rotatory instability of the elbow

BACKGROUND

Posteromedial rotatory instability (PMRI) of the elbow consists of an anteromedial coronoid fracture with lateral collateral ligament (LCL) and posterior bundle of the medial collateral ligament (PMCL) tears. We hypothesized that the LCL tear is required for elbow subluxation/joint incongruity and that an elbow affected by an anteromedial subtype 2 coronoid fracture and a PMCL tear exhibits contact pressures different from both an intact elbow and an elbow affected by PMRI.

MATERIALS AND METHODS

Six cadaveric elbows were tested under gravity varus stress using a custom-made machine designed to simulate muscle loads and to passively flex the elbow from 0° to 90° and measure joint contact pressures. After testing of the intact specimen (INTACT-elbow), an anteromedial subtype 2 coronoid fracture with a PMCL tear (COR+PMCL-elbow) and a PMRI injury (PMRI-elbow), after adding an LCL tear, were tested. The highest values of mean contact pressure were used for the comparison among the 3 groups.

RESULTS

Neither subluxation nor joint incongruity was observed in the COR+PMCL-elbow. The addition of an LCL detachment consistently caused subluxation and joint incongruity. Mean contact pressures were higher in the COR+PMCL-elbow compared with the INTACT-elbow (P < .03) but lower than in the PMRI-elbow (P < .001).

CONCLUSIONS

The LCL lesion in PMRI is necessary for elbow subluxation and causes marked elevations in contact pressures. Even without subluxation, the COR+PMCL-elbow showed higher contact pressures compared with the INTACT-elbow. Treatment of PMRI should be directed toward prevention of joint incongruity, whether by surgical or nonsurgical means, to prevent high articular contact pressures.

[Biomechanical effect of anteromedial coronoid facet fracture and lateral collateral ligament complex injury on posteromedial rotational stability of elbow]

Objective

To investigate the effect of anteromedial coronoid facet fracture and lateral collateral ligament complex (LCLC) injury on the posteromedial rotational stability of the elbow joint.

Methods

The double elbows were obtained from 4 fresh adult male cadaveric specimens. Complete elbow joint (group A, n=8), simple LCLC injury (group B, n=4), simple anteromedial coronoid facet fracture (group C, n=4), and LCLC injury combined with anteromedial coronoid facet fracture (group D, n=8). The torque value was calculated according to the load-displacement curve.

Results

There was no complete dislocation of the elbow during the experiment. The torque values of groups A, B, C, and D were (10.286±0.166), (5.775±0.124), (6.566±0.139), and (3.004±0.063) N·m respectively, showing significant differences between groups ( P<0.05).

Conclusion

Simple LCLC injury, simple anteromedial coronoid facet fracture, and combined both injury will affect the posteromedial rotational stability of the elbow.

Isolated ligamentous injury can cause posteromedial elbow instability: a cadaveric study

BACKGROUND

Elbow posteromedial rotatory instability (PMRI) is known to occur with fracture of the anteromedial coronoid and injury to the posterior bundle of the medial ulnar collateral ligament (pMUCL). However, whether instability results from isolated pMUCL injury remains unclear. The purpose of this study was to quantify displacement about the ulnohumeral joint to evaluate whether isolated sectioning of the pMUCL results in elbow PMRI.

METHODS

Nine cadaveric elbows underwent movements simulating PMRI by application of axial compression with varus and internal rotation moments. Gapping values at both the proximal and distal aspects of the medial ulnohumeral joint were then recorded for "intact" and "pMUCL-sectioned" elbows at positions of 30°, 60°, and 90° of flexion.

RESULTS

After pMUCL transection, torsion increased by 2.6° ± 0.7° (P = .054) at 30° and 4.5° ± 1.2° (P = .039) at 60° of flexion. Proximal ulnohumeral joint gapping also increased at 30° (1.4 ± 0.4 mm; P = .039), 60° (1.5 ± 0.6 mm; P = .039), and 90° (1.5 ± 0.7 mm; P = .017), respectively. No increases in distal ulnohumeral gapping occurred at any angle of flexion.

DISCUSSION

Sectioning of the pMUCL results in significant increases in torsion and displacement about the proximal ulnohumeral joint. Our findings demonstrate that elbow PMRI can occur secondary to isolated ligamentous injury. Clinicians mindful of this previously unrecognized role of the pMUCL as a stabilizer may wish to consider methods of restoring pMUCL integrity when treating medial elbow instability.

Selected anteromedial coronoid fractures can be treated nonoperatively

BACKGROUND

Surgical fixation is currently recommended for unstable anteromedial coronoid fractures, but the role of nonoperative management is not well defined. Our purpose was to report the functional and radiographic outcomes of select patients managed nonoperatively.

METHODS

Between 2006 and 2012, 10 patients with anteromedial coronoid fractures underwent nonoperative treatment. Outcomes assessed included elbow range of motion (ROM), stability, strength, radiographs, and 3 functional questionnaires, including the Patient-Rated Elbow Evaluation, Disabilities of Arm, Shoulder and Hand, and Mayo Elbow Performance Index.

RESULTS

There were 9 anteromedial subtype 2 coronoid fractures and 1 subtype 3. Mean fragment size was 5 mm, with a mean displacement of 3 mm for the subtype 2 fractures. The subtype 3 fracture was 9 mm in size with 1 mm of maximal gap displacement. At a mean follow-up of 50 months (range, 12-83 months), the average ROM of the affected elbow was 137° ± 8° of flexion, 2° ± 5° of extension, 88° ± 5° of pronation, and 86° ± 10° of supination. The mean Patient-Rated Elbow Evaluation score was 9 ± 13, Mayo Elbow Performance Index score was 94 ± 8, and the Disabilities of Arm, Shoulder and Hand score was 7 ± 9. All patients had bony union without radiographic arthrosis. There were no cases of recurrent instability or delayed surgical intervention.

CONCLUSIONS

Current indications for nonoperative management, based on the results of this study, include fractures that are small, minimally displaced, and most importantly, demonstrate no evidence of elbow subluxation. The elbow joint must be congruent and demonstrate a stable ROM to a minimum of 30° of extension. For selected anteromedial coronoid fractures, nonoperative management is an option that can lead to good clinical and radiographic outcomes.

Treatment of complex elbow fracture-dislocations

Successful management of complex elbow fracture-dislocations requires, in part, recognition of the overall injury pattern, which can aid in the identification of concomitant bony and soft tissue injuries. Trans-olecranon fracture-dislocations are best treated surgically with stable anatomic restoration of the trochlear notch. Terrible triad elbow injuries are believed to be caused by a valgus posterolateral force. Although select terrible triad injuries can be managed non-operatively, the majority of injuries are treated with stable surgical repair to allow early elbow motion. Unlike terrible triads, varus posteromedial forces are theorized to cause anteromedial coronoid fractures. These are usually associated with LCL disruptions, but do not have concomitant MCL or radial head injuries. A subset of anteromedial coronoid fractures can also be managed non-operatively. Internal fixation is recommended for injuries associated with large fracture fragments or elbow instability preventing early motion.

Coronoid Fractures

Fractures of the coronoid process of the ulna are usually part of a more complex injury. The type of coronoid fracture corresponds with a specific pattern of injury with known pitfalls and recommended treatments. Tip fractures usually correspond with dislocation of the elbow and fracture of the radial head (the so-called terrible triad of the elbow because it is prone to redislocation, subluxation, and arthrosis) and are best repaired with a suture passed through drill holes along with repair or replacement of the fractured radial head and reattachment of the lateral collateral ligament to the lateral epicondyle. Anteromedial fractures are usually part of a subluxation injury and are best addressed with a medial buttress plate and reattachment of the lateral collateral ligament. Large basilar coronoid fractures are usually part of an olecranon fracture-dislocation and are usually repaired with 1 or 2 plates and screws. Tenuous fixation is protected with temporary external fixation or cross-pinning of the joint because healing of the coronoid with concentric elbow alignment is critical.

LEVEL OF EVIDENCE

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

Drop sign of the elbow joint after surgical stabilization of an unstable simple posterolateral dislocation: natural course and contributing factors

BACKGROUND

We performed this study to investigate the natural course and factors affecting the incidence of drop sign immediately after stabilization of an unstable posterolateral (PL) dislocation of the elbow.

METHODS

Twenty-three patients who underwent a stabilization procedure for persistent instability after closed reduction of PL dislocation of the elbow were enrolled. The natural course was evaluated with simple radiographs taken at regular intervals after the operation. Primary repair of medial or lateral ligaments and overlying muscles, degree of adjacent muscle injury, and type of anesthesia were analyzed to determine their relationship to postoperative drop sign. Functional outcomes were evaluated by the Disabilities of the Arm, Shoulder, and Hand score and Mayo Elbow Performance Score.

RESULTS

A postoperative drop sign was observed in 4 cases (17%) and resolved within 1 week after the operation. There was no significant relationship between preoperative factors and drop sign except method of anesthesia. All drop signs were found in patients who had received a regional block (P = .006). There were no statistically significant differences in functional outcome between the drop sign group and the non-drop sign group.

CONCLUSIONS

A postoperative drop sign was observed in 17% of patients who underwent a surgical stabilization procedure for an unstable PL elbow dislocation; this sign spontaneously disappeared in all 4 patients within 1 week of the operation. The drop sign was possibly caused by delayed return of muscle tone. A postoperative drop sign did not indicate the need to perform an additional stabilization procedure, nor did it affect postoperative functional outcome.