Anteromedial coronoid facet fractures

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.

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.

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.

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.

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.

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.

Direct anterior approach for mini plate fixation of Regan-Morrey type II comminuted ulnar coronoid process fracture

BACKGROUND

The goal of this study was to evaluate the clinical effect of Regan-Morrey type II comminuted coronoid process fracture treated with mini plate through the direct anterior approach (DAA).

METHODS

Ten patients who underwent open reduction and internal fixation (ORIF) with mini plate through the DAA between February 2013 and August 2016 was included. There were three women and seven men, with an average age of 34.4 ± 7.5 years. At the final follow-up, the Mayo Elbow Performance Index (MEPS), Visual Analogue Scale (VAS) score, Disability of the Arm, Shoulder, and Hand (DASH) score, and the elbow range of motion were noted.

RESULTS

The mean follow-up was 26.3 ± 2.2 (range 24-31) months. The mean elbow arc of motion was 118.5° with a mean arc of extension of 4° ± 5.2° and flexion of 122.5° ± 7.2°.The mean forearm pronation was 72° ± 7.2°, and the mean supination was 68° ± 6.3° with a mean forearm rotation arc of 140°. The average postoperative score according to the MEPS was 91 ± 5.7 points (range 80-100 points), and all patients achieved satisfactory scores (8 excellent and 2 good). The final average VAS score was 0.6 ± 1 (range 0-3). The final average DASH score was 4.0 ± 1.6 (range 2.3-7.4). None of the patients complained about elbow instability that required secondary surgery. No complications of infection, joint incongruency, fracture nonunion, median nerve palsy, or implant failure were reported.

CONCLUSIONS

ORIF with mini plate through the DAA for the treatment of the type II comminuted coronoid process fractures can achieve satisfactory outcomes.

Chronic complex persistent elbow instability: a consecutive and prospective case series and review of recent literature

BACKGROUND

Chronic complex persistent elbow instability (CCPEI) is a condition that even expert elbow surgeons find challenging to treat. The results of the few studies that have dealt with the treatment of this condition are conflicting. We describe the surgical results of a consecutive prospective series of patients with CCPEI and provide a review of the recent literature.

METHODS

We assessed 21 patients with previous failed surgical or conservative treatment, with a terrible-triad injury in 13, Monteggia-like lesion in 6, humeral shear fracture-dislocation in 1, and radial head fracture-dislocation in 1. Overall, 21 open débridement procedures, 15 ulnar nerve transpositions, 6 ulnar in situ neurolysis procedures, 7 total elbow arthroplasties, 8 radial head arthroplasties, 1 radial head resection with humeroradial anconeus interpositional arthroplasty, 4 coronoid graft reconstructions, 14 ligament retensioning procedures, 3 ulnar nonunion treatments, and 2 ulnar osteotomies were performed. Two dynamic external fixators were applied. The Mayo Elbow Performance Score, quick Disabilities of the Arm, Shoulder and Hand score, and modified American Shoulder and Elbow Surgeons score were used preoperatively and postoperatively.

RESULTS

The mean follow-up period was 29.4 months. A significant improvement was found between preoperative and postoperative clinical scores and range-of-motion values. The reintervention and major complication rates were 19% and 23%, respectively. Arthritic evolution was observed in 71% of the cases.

CONCLUSIONS

CCPEI is a challenging condition with an uncertain prognosis. The variability in patients' pathoanatomic conditions requires customized surgical treatment aimed at elbow stabilizer reconstruction when the ulnohumeral joint is preserved or aimed at joint replacement in case of severe articular degeneration. The time interval between the initial trauma and index surgical procedure significantly affects the feasibility of reconstructive procedures.

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.

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.

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.

How should anteromedial coronoid facet fracture be managed? A surgical strategy based on O'Driscoll classification and ligament injury

BACKGROUND

Despite an improved understanding of coronoid anteromedial facet (AMF) fractures, the optimal treatment protocol and technique have not yet been established. The goals of the study were to describe the characteristics of AMF fractures, to suggest a surgical strategy, and to report the outcomes after treatment according to this protocol.

METHODS

This was a retrospective study of 19 patients with AMF fractures between 2010 and 2012. Eight patients were excluded because of secondary olecranon fracture, radial head fracture, and elbow dislocation, leaving 11 patients with isolated AMF fracture in the study cohort. There were 7 men and 4 women, with an average age of 42 years (range, 29-62 years). Fracture classification, injury pattern, and accompanying collateral ligament injury were analyzed. O'Driscoll subtype 1 fractures were treated with lateral collateral ligament (LCL) repair; O'Driscoll subtype 2 and subtype 3 fractures were treated with buttress plating and LCL repair. Plain radiographs were used to evaluate union, arthritic change, and joint articulation. Functional outcomes were evaluated with range of motion and the Mayo Elbow Performance Score.

RESULTS

Two patients had O'Driscoll anteromedial subtype 1 fracture, 4 patients had subtype 2, and 5 patients had subtype 3. Two patients with subtype 1 fracture had associated posterior dislocation; 9 patients with subtype 2 or subtype 3 had associated varus posteromedial injury. All 11 patients had associated LCL injury, and 6 patients had associated medial collateral ligament injury. The mean range of motion was 128°, and the average Mayo Elbow Performance Score was 89 points. Qualitatively, patient outcomes were scored excellent in 4 patients, good in 6 patients, and fair in 1 patient.

CONCLUSION

AMF fractures are almost always accompanied by collateral ligament injuries. Thus, our surgical strategies, which include collateral ligament repair, are able to stabilize and result in favorable clinical outcomes. On the basis of our results, we recommend LCL repair alone for subtype 1 fractures and buttress plating and LCL repair for subtype 2 and subtype 3 fractures.

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

BACKGROUND

The purpose of this study was to suggest a strategic approach to the management of anteromedial coronoid facet (AMCF) fracture that is related to posteromedial rotational instability of the elbow through investigation of the surgical outcome of diverse combinations, including internal fixation of AMCF fractures and repair of collateral ligament injury.

METHODS

The study enrolled 18 patients. On the basis of the size of the coronoid fracture and the degree of the soft tissue injuries that were evaluated with computed tomography, magnetic resonance imaging, and varus stress test under anesthesia, these fractures were managed differently. Functional outcomes were evaluated with the visual analog scale score, modified Mayo Elbow Performance Score, and Disabilities of the Arm, Shoulder and Hand score. Plain radiographs were used to evaluate the degree of arthrosis.

RESULTS

There were 2 cases of O'Driscoll type 2, subtype 1 fractures; 14 cases of type 2, subtype 2 fractures; and 2 cases of type 2, subtype 3 fractures. Seven cases were managed with only AMCF fracture fixation, 4 cases with only lateral ulnar collateral ligament (LUCL) repair, 6 cases with concomitant repair of the LUCL and AMCF fracture, and 1 case with a conservative method. There were no significant differences among O'Driscoll types and among the subgroups of type 2-2 (P > .05). When the elbow showed instability on the varus stress test after AMCF fracture fixation, the soft tissue injuries of the lateral elbow were more severe (P =. 015). Arthrosis was not correlated with the patient's symptoms (P > .05).

CONCLUSION

AMCF fracture can be treated by only AMCF fracture fixation, only LUCL repair, or a combination of these techniques, depending on the size of the AMCF fracture fragment and the degree of the lateral soft tissue injuries.

Non surgically managed anteromedial coronoid fractures in posteromedial rotatory instability: three cases with 2 years follow-up

Varus posteromedial rotatory instability refers to one of the complex elbow fracture-dislocation caused by anteromedial coronoid fracture with disruption of lateral collateral ligament (LCL). Recent clinical and biomechanical studies have demonstrated that this unstable complex injury resulted in incongruence of joint, which could lead to early posttraumatic arthritis. With reports of poor result after conservative treatment, surgical treatment including anteromedial fixation and LCL repair has been strongly recommended to achieve stable joint. This case series describes three patients with anteromedial coronoid fracture who were managed conservatively with excellent outcomes. This report suggests that anteromedial coronoid fracture associated with posteromedial rotatory instability might be treated using conservative treatment in selective cases when anteromedial coronoid fracture is minimally displaced and there is no evidence of elbow subluxation.