Is partial excision of the radial head safe and effective in all-arthroscopic treatment of terrible triad fractures?

Hyung Gyu Cho; Gyeong Hoon Lim; Min Su Joo; Jae Won Kim; Jun Ho Park; Jeong Woo Kim

doi:10.5397/cise.2024.00703

Clin Shoulder Elb > Volume 27(4); 2024 > Article

Cho, Lim, Joo, Kim, Park, and Kim: Is partial excision of the radial head safe and effective in all-arthroscopic treatment of terrible triad fractures?

Original Article

Clinics in Shoulder and Elbow 2024; 27(4): 454-463.

Published online: November 5, 2024

DOI: https://doi.org/10.5397/cise.2024.00703

Is partial excision of the radial head safe and effective in all-arthroscopic treatment of terrible triad fractures?

Hyung Gyu Cho^1,^*

, Gyeong Hoon Lim^2,^*

, Min Su Joo³

, Jae Won Kim¹

, Jun Ho Park¹

, Jeong Woo Kim¹

¹Department of Orthopedic Surgery, Wonkwang University Hospital, Iksan, Korea

²Department of Orthopedic Surgery, Saint Carollo Hospital, Suncheon, Korea

³Department of Orthopedic Surgery, Design Hospital, Jeonju, Korea

Corresponding author: Jeong Woo Kim Department of Orthopedic Surgery, Wonkwang University Hospital, 895 Muwang-ro, Iksan 54538, Korea
Tel: +82-63-859-1360, Fax: +82-63-852-9329, Email: serina@wonkwang.ac.kr

^*These authors contributed equally to this study as co-first authors.

Received: September 10, 2024 Revised: September 22, 2024 Accepted: September 24, 2024

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

Our study aimed to evaluate the clinical and radiologic results of all-arthroscopic treatment of terrible triad injuries followed-up for a minimum of 5 years and investigate how arthroscopic partial excision for radial head fractures affects the results at the final follow-up.

Methods

We retrospectively reviewed consecutive patients with terrible triad injuries who underwent all-arthroscopic treatment between January 2011 and June 2018. In group I, we performed conservative or arthroscopic fixation of stable radial head fractures, while in group II, arthroscopic partial excision of unstable radial head fractures involving <30%–50% of the articular surface area was performed. Clinical outcomes were measured by visual analog scale score and assessment of instability, range of motion (ROM), and Mayo Elbow Performance Score. Radiological outcomes were evaluated using x-rays, and the integrity of the repaired lateral collateral ligament complex was confirmed through magnetic resonance imaging.

Results

Thirty-two patients with an average age of 49.5±16.2 years met the inclusion criteria and were followed-up for a mean of 82.7±22.2 months. Twenty patients were assigned to group I and 12 patients to group II. Clinical outcomes showed no significant differences between the two groups at the final follow-up (P>0.05). On radiological evaluation, more heterotopic ossifications were found in the radial head excision group (group II, 66.7% vs. group I, 35%; P=0.02); however, there was no significant difference in ROM between the two groups (P>0.05).

Conclusions

In all-arthroscopic treatment of terrible triad injuries, arthroscopic partial excision of the radial head did not seem to have a significant impact on elbow joint stability.

Level of evidence

III.

Key Words: Elbow injury; Radial head; Arthroscopic surgical procedure; Arthroscopy

INTRODUCTION

Terrible triad injury of the elbow refers to the simultaneous occurrence of ulnohumeral joint dislocation, radial head fracture, and coronoid process fracture. Originally described by Hotchkiss in 1996 [1], this injury is more challenging to treat and has a poorer prognosis than a simple dislocation. However, arthroscopic management has been proposed as a safe and effective approach to reduce complications such as capsular fibrosis and the resulting stiffness commonly observed after surgery for terrible triad injury. Arthroscopic treatment of terrible triad injury offers advantages over traditional open surgery, including improved visualization, better wound healing, and preservation of critical soft-tissue structures [2,3]. Several previous studies have investigated arthroscopic treatment for terrible triad injuries [4-7], and Lee et al. [8] reported satisfactory clinical outcomes in 24 patients who underwent arthroscopy.

In the management of radial head fractures with comminution in terrible triad injuries, partial excision of the radial head has been suggested as a viable option because of the difficulty in restoring severely comminuted radial heads [9,10]. Yang et al. [11] compared the outcomes of arthroscopic partial excision of the radial head and conservative treatment in cases of elbow fracture-dislocation with comminuted radial head fractures involving <50% of the articular surface. They reported favorable clinical results at an average follow-up of 28 months, and concluded that arthroscopic partial excision is an acceptable treatment option. However, considering the role of the radial head in elbow joint stability, there have been few long-term follow-up studies on the effects of partial radial head excision on elbow joint stability and degenerative changes.

This study aimed to analyze the effects of radial head partial excision in all-arthroscopic treatment of terrible triad injuries. We hypothesized that there would be no significant differences in clinical outcomes, including stability and joint degeneration, between the group undergoing arthroscopic treatment for terrible triad injuries with radial head excision (in cases involving <30–50% of the articular surface’s unstable fracture fragments) and those undergoing stable conservative treatment or fixation.

METHODS

This study was approved by the Institutional Review Board of Wonkwang University Hospital (No. WKUHIRB 2023-06-018). The need for informed consent was waived due to the retrospective design of the study.

Patient Selection

We conducted a retrospective review of consecutive patients with terrible triad injuries who underwent all-arthroscopic treatment between January 2011 and June 2018. Inclusion criteria were as follows: (1) patients who underwent all-arthroscopic treatment for terrible triad injury and (2) patients with a follow-up period of at least 5 years. Exclusion criteria were as follows: (1) patients with other fractures of the ipsilateral upper extremity; (2) patients with a previous fracture in an injured region; (3) patients who underwent open reduction and internal fixation (ORIF) of the radial head, neck, or radial head replacement; (4) patients with open injuries; (5) patients with concomitant neurovascular injuries; and (6) patients aged <18 years.

Surgical Technique for All-Arthroscopic Treatment

All arthroscopic treatments for terrible triad injuries were performed under the following conditions: incongruently reduced ulnohumeral and radiocapitellar joints on lateral radiographs after manual reduction (positive drop arm sign), incarcerated bone fragments in the elbow joint, and cases requiring flexion of >30° for elbow stability. Details of the treatment algorithm are summarized in Fig. 1.

All surgeries were performed by a senior surgeon within 1 week of injury. Surgeries were performed with a tourniquet applied around the upper arm, and the patients in the lateral decubitus position, with both general anesthesia and a brachial plexus block. Normal saline was injected through the lateral soft-spot portal (in a triangle formed by the olecranon, radial head, and lateral epicondyle) to distend the joint space, followed by diagnostic arthroscopy through the proximal anteromedial viewing portal (2 cm anterior and 2 cm distal to the medial epicondyle) to assess the extent of joint damage. We also used the proximal anterolateral, anterolateral, and radial head portals as working portals.

Lateral Collateral Ligament Complex Repair and Coronoid Process Fracture

Subsequently, we aimed to restore elbow stability by performing an all-arthroscopic treatment for combined coronoid process fractures, anterior capsular avulsions, and lateral collateral ligament (LCL) complex injuries. The surgical technique for the LCL complex and coronoid process was based on the description of Lee et al. [8].

To repair the LCL complex, a radial head portal was created as a new working portal. This portal was located 0.5 cm posterior to a point 1–1.5 cm distal to the lateral epicondyle, and just above the radial head with the elbow in 90o of flexion. A spinal needle was inserted through the radial head portal and passed through the LCL complex stump. A polydioxanone suture (Ethicon) was passed through the spinal needle, and a FiberWire (Arthrex) was attached to the polydioxanone suture for the shuttle relay. This process was repeated to create a Mason-Allen stitch. Using a spinal needle, a portal was created above the Footprint, and the LCL complex was secured to the footprint using FiberWire. A knotless anchor suture (Reelx STT; Stryker or PopLok; CONMED) was used to fix the FiberWire to the LCL complex footprint at the humeral attachment site.

Treatment of coronoid process fractures was based on fragment size. For cases in which the fragment was sufficiently large for Kirschner-wire passage, we used 2–3 multiple Kirschner wires for fixation. For smaller fragments, Ethibond (Ethicon) was used to suture the anterior capsule around the coronoid process for reduction. Using a 2.7-mm drill bit on the ulna, we created two holes in the direction of the fracture site through which Ethibond was passed to perform a pull-out suture.

Radial Head Fracture

Management of radial head fractures was determined based on preoperative three-dimensional computed tomography and intraoperative arthroscopic findings (Fig. 1). Radial head fractures with articular surface displacement of <2–4 mm were treated conservatively. Arthroscopic fixation was achieved with a headless screw or Kirschner wire if the radial head fracture was displaced by >2–4 mm; however, arthroscopic reduction was possible with the probe (Fig. 2). If the radial head was completely displaced and arthroscopic reduction was not possible, arthroscopic partial excision or open surgery was performed, depending on the degree of articular surface involvement. Arthroscopic partial excision was performed for radial head fractures involving <30%–50% of the articular surface (Fig. 3). Cases with involvement of ≥50% of the radial head underwent ORIF or radial head replacement, depending on the degree of comminution, and these patients were excluded from this study.

Patient Groups

Based on the surgical intervention performed on the radial head, patients were classified into two groups. Group I comprised patients who underwent conservative treatment or arthroscopic fixation for radial head fractures. This group was used as the control group because the integrity of the radiocapitellar joint was maintained. Patients who underwent arthroscopic partial excision were assigned to group II.

Postoperative Management

Immediately after surgery, the elbow was immobilized with a splint at 90° flexion for 2–3 days. Subsequently, the splint was replaced with an elbow hinged brace, and passive range of motion (ROM) exercises were performed with a 30° extension block for up to 4 weeks postoperatively. After 4 weeks, full ROM was allowed, and outpatient follow-ups were conducted at 6 weeks, 3 months, 6 months, 12 months, and 2 years. Additional follow-up examinations were also performed. Light muscle exercises were initiated at 6 weeks postoperatively, and full activity was allowed at 3 months postoperatively.

Clinical and Radiologic Evaluation

Outpatient follow-ups were conducted at 6 weeks, 3 months, 6 months, 12 months, 2 years, and annually thereafter. Visual analog scale (VAS), Mayo Elbow Performance Score (MEPS), and ROM were assessed at each follow-up visit after 3 months, and the posterolateral pivot shift test and varus & valgus stress tests were administered at each follow-up visit after 2 years. Postoperative complications were assessed at each follow-up. Elbow ROM was measured during flexion, extension, supination, and pronation using a manual goniometer.

Radiological evaluation included standard anteroposterior and lateral radiographs of the elbow obtained in a neutral forearm position. Radiographs were used to assess bone union, varus or valgus deformities, heterotopic ossification (HO), and radiocapitellar and ulnohumeral arthroses. The occurrence of HO was assessed using the Hastings classification system [12]. Elbow joint arthrosis was evaluated using the Broberg-Morrey classification system [13]. The integrity of the repaired LCL complex was confirmed using magnetic resonance imaging at 6 months postoperatively and simple radiography during outpatient visits. For patients who had difficulty with follow-up, owing to distance to the hospital or personal reasons, clinical evaluations were conducted by directly visiting the patient, and radiological evaluations were performed using data obtained from nearby hospitals.

Statistical Analysis

Statistical analyses were performed using SPSS for Windows version 12.0 (SPSS Inc.). Statistical comparisons of the two groups were performed using Student t-test for normal data and the Mann-Whitney test for non-normal continuous data, whereas the chi-square test was used for categorical data. The occurrence of elbow arthritis and HO was compared between the two groups using the chi-square test.

RESULTS

Between January 2011 and June 2018, 50 patients with terrible triad injuries underwent surgery. Among these 50 patients, 18 were excluded: four had combined fractures in the injured limb, nine underwent ORIF or radial head replacement, and five were lost to follow-up for various reasons. Thus, 32 patients were included in this retrospective comparative cohort study. Of these, 23 patients were male, mean age was 49.5±16.2 years (range, 18–72 years), and mean follow-up duration was 82.7±22.2 months (range, 60–126 months). There were six cases of radial head fixation and 14 cases of conservative treatment of the radial head in group I, totaling 20 patients, while group II comprised 12 patients who underwent radial head partial excision. Patient characteristics, comorbidities, and mechanisms of injury are described in Table 1.

Clinical and Radiologic Evaluations

There were no significant differences in VAS, MEPS, or ROM between the two groups at the final follow-up (P>0.05). Based on radiological evaluation, the drop sign of the elbow joint improved after surgery in all patients, and bone union was achieved in all radial head fractures in group I. Elbow joint arthritis was observed in group I as follows: grade 1 in five cases and grade 2 in two cases (total of seven cases). In group II, there were two cases of grade 1, one case of grade 2, and one case of grade 3 (total of four cases) arthritis. There were no significant differences in the occurrence of elbow joint arthritis between the two groups (P=0.92). HO was observed in seven gases in group I (35%), all of which were classified as class I, and eight cases in group II (66.7%), of which seven were class I and one was class IIA. Patients in group II had a significantly higher occurrence of HO than patients in group I (P=0.02) (Fig. 4). Details of the clinical and radiological evaluations are presented in Table 2.

Complications

There were no major complications, such as elbow joint instability or neurovascular injury, in either group. Non-union of the coracoid process occurred in four cases (three and one in groups I and II, respectively), but did not lead to instability or other clinical symptoms. One patient experienced pin-site irritation due to fixation of the coronoid fracture; however, their symptoms resolved after pin removal. In group II, one patient experienced worsening pain and ROM, leading to total elbow arthroplasty at 5 years after the follow-up. However, in this case, the patient had been treated for rheumatoid arthritis for a long time, and the underlying disease may have contributed to worsening of symptoms (Fig. 5).

DISCUSSION

In this study, we found no significant difference in the incidence of arthritis when comparing patients with and without partial excision of the radial head. The incidence of HO was significantly higher in the radial head excision group; however, there were no significant differences in ROM or clinical outcomes between the two groups at the final follow-up. These findings suggest that partial excision of the radial head does not affect stability or cause degenerative changes in the elbow joint. Thus, our hypothesis was supported: after stability is achieved through repair of the LCL complex and coronoid process or anterior capsule, partial excision of the radial head can be a time- and cost-effective option, especially when the size of the radial head fragment is <30%–50%.

This study is meaningful in that, unlike previous studies, we assessed clinical and radiological outcomes for a minimum of 5 years after all-arthroscopic treatment in patients with terrible triad injury. In particular, it is noteworthy that we confirmed that stability can be maintained even after excision of up to 50% of the radial head in terrible triad injuries, not isolated radial head fractures, provided that coronoid fractures and LCL complex injuries are treated appropriately.

The radial head is crucial for elbow stability, and fixation or replacement is recommended for fractures [14-16]. However, open surgery carries the risk of neurovascular injury and complications, such as postoperative stiffness. To avoid such complications, various studies have reported the advantages of arthroscopic procedures for joint injuries, not only in chronic elbow pathology but also in acute elbow trauma [4-7]. Lee et al. [8] treated 24 patients with terrible triad injuries using all-arthroscopy and reported 15 excellent and 9 good elbow performance outcomes in their study. In that study, groups with and without radial head partial excision were compared after all-arthroscopic treatment for LCL complex and coronoid fractures. The excision group, at 6.9 years of follow-up, showed good stability and satisfactory clinical results.

In the present study, the incidence of HO was significantly higher in patients who underwent partial radial head excision. However, in all but one case, minor HO within the collateral ligament was observed, and both groups demonstrated good ROM without significant differences. One patient had class IIA HO, causing limited ROM (5–110 in extension-flexion), but the patient’s clinical score, including pain score, was good; therefore, the patient opted not to undergo additional surgical procedures, such as arthroscopic debridement. HO is a well-known complication of joint injuries, occurring in 2%–56% of cases [17,18]. Factors, such as genetic predisposition, trauma severity, associated nerve injury, surgical approach, and hematoma formation contribute to the risk of developing HO [19-25]. Bauer et al. [26] reported that the interval from injury to surgery and duration of postoperative joint immobilization increased the risk of HO. As this study involved all arthroscopic procedures, surgeries were conducted within 7 days of injury, and immobilization was maintained for only 2–3 days followed by passive ROM exercises with a hinged brace. Most radial head fractures in terrible triad injuries result from a shearing force between the radial head and humeral capitellum, causing anterior radial head or entire joint surface fractures [27]. Therefore, the severity of the trauma may increase the shearing force applied to the radial head, thereby increasing the risk of HO after surgery.

This study had some limitations. First, it included a relatively small number of patients. Second, this was a retrospective study, and the choice of surgical method was subjectively determined by a single surgeon. Therefore, additional randomized studies are required in the future. Third, because we performed arthroscopic treatment in cases that met the specific conditions of terrible triad injuries, it is not appropriate to generalize the results of this study to all patients with terrible triad injuries. However, we believe that if arthroscopic treatment is performed in cases where it is available, various complications related to open surgery (e.g., infections, soft tissue problems, and long recovery times) can be reduced. Finally, although HO was significantly higher in the group that underwent radial head excision, further studies are necessary to determine whether long-term follow-up reveals changes in ROM or arthritic changes associated with the increased incidence of HO.

CONCLUSIONS

After elbow joint stability is achieved by repairing the LCL complex and coronoid process in all-arthroscopic treatment for terrible triad injuries, arthroscopic partial excision of the radial head, involving <30%–50% of the articular surface, does not have a significant negative impact on elbow joint stability.

NOTES

Author contributions

Conceptualization: HGC, GHL, MSJ, JWK. Data curation: HGC, JWK, JHP. Formal analysis: HGC, GHL, MSJ. Investigation: GHL, MSJ. Methodology: HGC, GHL, MSJ, JWK. Project administration: JWK. Supervision: JWK. Validation: HGC, GHL, MSJ, JWK. Visualization: HGC, JWK, JHP. Writing – original draft: HGC, GHL. Writing – review & editing: HGC, MSJ, JWK.

Conflict of interest

None.

Funding

None.

Data availability

Contact the corresponding author for data availability.

Acknowledgments

None.

Fig. 1.

Surgical algorithm and technique for all-arthroscopic treatment. In group I, patients with articular surface displacement of less than 2 mm were treated conservatively, and arthroscopic fixation was achieved with a headless screw or Kirschner-wire if the radial head fracture was stable and reducible with probe. In group II, patients with comminuted or unstable displaced radial head fractures involving less than 30%–50% of the articular surface underwent arthroscopic fragment excision. Cases with involvement of 50% or more underwent open reduction and internal fixation (ORIF) or radial head replacement. LUCL: Lateral ulnar collateral ligament.

Fig. 2.

(A) Preoperative three-dimensional computed tomography image. (B) Arthroscopic finding of radial head fracture (left elbow). (C) Arthroscopic finding of radial head fracture after arthroscopic reduction with probe. (D) Arthroscopic finding of secured fixation with a headless screw.

Fig. 3.

(A) Preoperative three-dimensional computed tomography image. (B) Arthroscopic finding of comminuted radial head fracture (right elbow). (C) Arthroscopic finding of radial head fracture after excision of fracture fragments.

Fig. 4.

A 61-year-old man who had radial head partial excision, anterior capsular repair for coronoid process fracture, and lateral collateral ligament complex repair with knotless anchor. (A-C) Preoperative anteroposterior (A) and lateral (B) radiographs and three-dimensional computed tomography image (C) of the right elbow, (D) fracture fragment partially excised during the procedure. (E, F) Initial anteroposterior (E) and lateral (F) radiographs taken at the time of the procedure. (G, H) Anteroposterior (G) and lateral (H) radiographs, taken 6 years postoperatively, showing multiple instances of heterotopic ossification.

Fig. 5.

A 63-year-old woman with Sjögren's syndrome and rheumatoid arthritis (RA) who had radial head partial excision, anterior capsular repair for coronoid process fracture, and lateral collateral ligament complex repair with a knotless anchor. After 5 years of follow-up, total elbow arthroplasty (TEA) was performed due to worsening of RA. (A, B) Preoperative anteroposterior (A) and lateral (B) radiographs of the left elbow. (C, D) Initial anteroposterior (C) and lateral (D) radiographs after surgery. (E, F) Anteroposterior (E) and lateral (F) radiographs, taken 5 years postoperatively, showing severe arthritic change due to worsening of RA. (G, H) Anteroposterior (G) and lateral (H) radiographs after TEA.

Table 1.

Demographics of the two groups

Variable	Group I (n=20)	Group II (n = 12)	P-value
Age (yr)	51.4±15.9	46.3±16.8	0.40
Male sex	15 (75.0)	8 (66.6)	0.61
Follow-up (mo)	82.5±22.9	83.0±22.1	0.87
Dominance	14 (70.0)	7 (58.3)	0.43
Injury mechanism			0.09
Fall from height	5 (25.0)	3 (25.0)
Slip down	14 (70.0)	6 (50.0)
Passenger TA	1 (5.0)	3 (25.0)
Radial head fracture (Maison classification)			0.007
I	15 (75.0)	0
II	5 (25.0)	11 (91.7)
III	0	1 (8.3)
Coronoid process fracture (Regan & Morrey classification)			0.11
I	5 (25.0)	4 (33.3)
II	15 (75.0)	8 (66.7)
III	0	0

Values are presented as mean±standard deviation or number (%).

TA: traffic accident.

Table 2.

Comparison of radiologic outcomes between two groups at final follow-up

Variable	Group I (n=20)	Group II (n=12)	P-value
VAS	1.4±0.6	1.6±1.0	0.48
MEPS	93±8.0 (80–100)	91.2±10.0 (70–100)	0.48
Range of motion (^o)
Flexion	133.2±3.5 (100–140)	130.8±10.8 (100–140)	0.07
Extension	3.7±5.0 (0–15)	3.3±7.2 (0–25)	0.09
Supination	85±5.2 (70–90)	81.5±4.8 (65–90)	0.40
Pronation	83.7±3.4 (75–90)	86.5±2.8 (80–90)	0.25
Ulnohumeral & radiocapitellar arthritis	7 (35)	4 (33.3)	0.92
Grade 1	5 (25)	2 (16.7)
Grade 2	2 (10)	1 (8.3)
Grade 3	0	1 (8.3)
Heterotopic ossification	7 (35)	8 (66.7)	0.02
Class I	7 (35)	7 (58.3)
Class IIA	0	1 (8.3)
Class IIB	0	0
Class IIC	0	0
Class III	0	0
Abnormal radiocapitellar alignment	0	0	-

Values are presented as mean±SD, mean±SD (range), or number (%).

VAS: visual analog scale, MEPS: Mayo Elbow Performance Score, SD: standard deviation.

REFERENCES

1. Hotchkiss RN. Fractures and dislocations of the elbow. In: Rockwood CA, Green DP, Bucholz RW, Heckman JD, eds. Rockwood and Green’s fractures in adults. 4th ed. Lippincott-Raven; 1996. p. 929–1024.

2. Savoie FH, Field LD, Gurley DJ. Arthroscopic and open radial ulnohumeral ligament reconstruction for posterolateral rotatory instability of the elbow. Hand Clin 2009;25:323–9.

3. Valencia M, Foruria AM. The role of arthroscopy in the management of adult elbow trauma. J Exp Orthop 2023;10:144.

4. Michels F, Pouliart N, Handelberg F. Arthroscopic management of Mason type 2 radial head fractures. Knee Surg Sports Traumatol Arthrosc 2007;15:1244–50.

5. Lee JM, Yi Y, Kim JW. Arthroscopically assisted surgery for coronoid fractures. Orthopedics 2015;38:742–6.

6. Kim JW, Yi Y, Kim TK, et al. Arthroscopic lateral collateral ligament repair. J Bone Joint Surg Am 2016;98:1268–76.

7. Fink Barnes LA, Parsons BO, Hausman M. Arthroscopic management of elbow fractures. Hand Clin 2015;31:651–61.

8. Lee SH, Lim KH, Kim JW. Case series of all-arthroscopic treatment for terrible triad of the elbow: indications and clinical outcomes. Arthroscopy 2020;36:431–40.

9. Faldini C, Nanni M, Leonetti D, et al. Early radial head excision for displaced and comminuted radial head fractures: considerations and concerns at long-term follow-up. J Orthop Trauma 2012;26:236–40.

10. Wijeratna M, Bailey KA, Pace A, Tytherleigh-Strong G, Van Rensburg L, Kent M. Arthroscopic radial head excision in managing elbow trauma. Int Orthop 2012;36:2507–12.

11. Yang HS, Kim JW, Lee SH, Yoo BM. Comminuted radial head fracture in all-arthroscopic repair of elbow fracture-dislocation: is partial excision of the radial head an acceptable treatment option. Clin Shoulder Elb 2018;21:234–9.

12. Hastings H, Graham TJ. The classification and treatment of heterotopic ossification about the elbow and forearm. Hand Clin 1994;10:417–37.

13. Broberg MA, Morrey BF. Results of delayed excision of the radial head after fracture. J Bone Joint Surg Am 1986;68:669–74.

14. Jensen SL, Olsen BS, Søjbjerg JO. Elbow joint kinematics after excision of the radial head. J Shoulder Elbow Surg 1999;8:238–41.

15. Beingessner DM, Dunning CE, Gordon KD, Johnson JA, King GJ. The effect of radial head excision and arthroplasty on elbow kinematics and stability. J Bone Joint Surg Am 2004;86:1730–9.

16. Charalambous CP, Stanley JK, Siddique I, Powell E, Ramamurthy C, Gagey O. Radial head fracture in the medial collateral ligament deficient elbow; biomechanical comparison of fixation, replacement and excision in human cadavers. Injury 2006;37:849–53.

17. Ilahi OA, Strausser DW, Gabel GT. Post-traumatic heterotopic ossification about the elbow. Orthopedics 1998;21:265–8.

18. Keschner MT, Paksima N. The stiff elbow. Bull NYU Hosp Jt Dis 2007;65:24–8.

19. Citta-Pietrolungo TJ, Alexander MA, Steg NL. Early detection of heterotopic ossification in young patients with traumatic brain injury. Arch Phys Med Rehabil 1992;73:258–62.

20. Cohen RB, Hahn GV, Tabas JA, et al. The natural history of heterotopic ossification in patients who have fibrodysplasia ossificans progressiva: a study of forty-four patients. J Bone Joint Surg Am 1993;75:215–9.

21. Failla JM, Amadio PC, Morrey BF, Beckenbaugh RD. Proximal radioulnar synostosis after repair of distal biceps brachii rupture by the two-incision technique: report of four cases. Clin Orthop Relat Res 1990;(253):133–6.

22. Gardner RJ, Yun K, Craw SM. Familial ectopic ossification. J Med Genet 1988;25:113–7.

23. Garland DE, Shimoyama ST, Lugo C, Barras D, Gilgoff I. Spinal cord insults and heterotopic ossification in the pediatric population. Clin Orthop Relat Res 1989;(245):303–10.

24. Riegler HF, Harris CM. Heterotopic bone formation after total hip arthroplasty. Clin Orthop Relat Res 1976;(117):209–16.

25. Sawyer JR, Myers MA, Rosier RN, Puzas JE. Heterotopic ossification: clinical and cellular aspects. Calcif Tissue Int 1991;49:208–15.

26. Bauer AS, Lawson BK, Bliss RL, Dyer GS. Risk factors for posttraumatic heterotopic ossification of the elbow: case-control study. J Hand Surg Am 2012;37:1422–9.

27. Johnston GW. A follow-up of one hundred cases of fracture of the head of the radius with a review of the literature. Ulster Med J 1962;31:51–6.