Radial head fractures

Fractures of the radial head are extremely common injuries. The radial head not only forms an important part of elbow anatomy, taking part in flexion-extension and pronation-supination but also acts as an anti-glide force for the radial shaft which slides proximally following fractures or excision which may cause chronic symptoms and disability. In-vitro studies also confirm that the radial head is an important contributor to valgus stability.

Fractures of the radial head are extremely common injuries. The radial head not only forms an important part of elbow anatomy, taking part in flexion-extension and pronation-supination but also acts as an anti-glide force for the radial shaft which slides proximally following fractures or excision which may cause chronic symptoms and disability. In-vitro studies also confirm that the radial head is an important contributor to valgus stability.

Epidemiology
Radial head and neck fractures are common and are co-incident in about 30 percent of all elbow injuries. They represent between 1.5 percent and 5 percent of all adult fractures. Though radial head fractures occur throughout adulthood the average age of presentation is around 44 years. Radial fractures are overall uncommon in children yet fractures of the radial neck occur more frequently than adults.

Aetiology

• Usually caused by a fall on the outstretched hand causing direct longitudinal forces to act on the redial head and neck impacting against the capitellum.
• Radial head fractures associated with elbow dislocation
• Direct impact or assault on the lateral aspect of the elbow is the third most common cause

Clinical picture

• Pain on the lateral aspect of the elbow
• Bruising on the lateral aspect of the elbow and forearm
• The patient is reluctant to move the elbow due to associated painful haemarthrosis.
• Motion elicits crepitus palpated by the examiners thumb placed over the radial head
• The forearm and wrist should be examined carefully. It is common to get forearm tenderness along its length due to bruising or tear of the interosseous membrane.
• The wrist should be examined for tenderness caused from distal wrist sprain (distal radio-ulnar joint sprain or subluxation) secondary to interosseous membrane rupture or strain, causing the radius to slide proximally.
• Also look for tenderness and bruising medially as the medial collateral ligament may be ruptures in severe valgus force acting on the elbow joint.

Investigations

• Digital radiographs are invaluable in diagnosing radial head fractures. The antero-posterior and the lateral views are sufficient to diagnose a majority these fractures.
• Look for a fat pad sign if a fracture is suspected without showing up on the radiographs. In such cases oblique views or radiocapitellar views can be done. The radio-capitellar view is taken with the forearm in neutral rotation with the x-ray tube angled 45 degrees superiorly.
• If in doubt or to delineate the fracture further, fluoroscopy can be performed or a CT scan with magnification and 3-D reconstruction gives the best results.
• Radiographs and CT scans usually also pick up subtle compact fractures of the capitellum or the coronoid process of the ulna.
• Examination under anaesthesia is sometimes invaluable to note severe crepitus or a mechanical block to rotations.

Classification or Staging
The Schatzker and Tile classification describes 3 types of radial head fractures:

Type I: Split wedge fractures. These can be displaced or undisplaced
Type II: Impaction fractures. In this pattern part of the head and neck remains intact. The portion involved in the fracture is tilted and impacted.
Type III: Severely comminuted fractures

The Schatzker classification provided a fairly pointer towards management and has limited role in predicting outcomes.

The Mason classification of fractures of the radial head:

Type I: Undisplaced segmental fractures
Type II: Displaced segmental fractures
Type III: Comminuted fractures of the head
Type IV: Any of the above types with posterior dislocation of the elbow

The Mason Classification is purely radiological and has been found insufficient to guide treatment or predict outcomes.

The AO classification describes patterns as:

1. Simple (21-B2.1)
2. Multifragmentary without depression (21-B2.2)
3. Multifragmentary with depression (21-B2.3)

The AO classification is good for coding across a variety of situations yet has proved unpopular in actual practice due to its complexity and inter-observer variability.

Main Principles of Treatment:

• Preservation of motion of the elbow
• Preservation of the anatomic radial head insofar as possible.
• A painful haemarthrosis occasionally precludes a full proper examination. Aspiration of the haemarthrosis through the “safe triangle” (formed by the lateral epicondyle, the radial head and the olecranon) and injection of local anesthetic is sufficient to give significant relief for examination.
• In absence of bony block, early active range of motion exercises to regain maximum motion is undertaken
• If there is a bony block to rotation, surgery is indicated to remove the block.

Indications for Surgical Treatment:

• Major loose intra-articular fragments
• Displaced fractures causing mechanical block to rotation
• Displaced fractures and/or associated fractures like fracture of the olecranon or coronoid, or rupture of the ulnar collateral ligament or any such combination.
• Fractures associated with injury to the interosseous membrane and the distal radio-ulnar joint

Treatment according to Masons classification
Type I Mason fractures

• In the past treated by immobilisation for 2-4 weeks
• Sling immobilisation in the acute phase with analgesia and active motion as early as tolerated is the preferred mode of treatment.
• Early motion may actually mould certain incongruous surfaces without significant risk of displacement.
• Local aspiration and instillation of local anaesthetic in the joint may reduce pain and encourage active motion. This however does not change final long term outcomes!
• Minimal loss of extension is common up to 10 degrees and the patient should be warned about this in the first instance. Loss of rotations can be as much as 20 degrees.
• Rarely some patients with Type I fractures do poorly either due to displacement or an affliction with a type of Reflex Sympathetic Dystrophy or a fracture of the capitellum which was initially missed.

Type II Mason fractures

• Type II fractures should ideally be examined under anesthesia to determine mechanical block if any, to rotation
• In the absence of a mechanical block, the treatment is similar to Type I fractures. Analgesia with sling immobilisation in the initial stage followed by early active motion. If these fractures subsequently undergo displacement then an excision may be required at 2-3 weeks especially if a mechanical block develops.
• With a mechanical block in the elderly patient, immediate surgery with excision is a viable option.
• With a mechanical block in the younger patient, open reduction and internal fixation is advocated.
• If the surgeon is unsure of the presence of a mechanical block, the patient should be reassessed at one weekly interval till rotations improve or a block develops.
• Herbert screws and now, biodegradable screws are being used for fixations.

Type III fractures

• Early excision with immediate motion was recommended in the past
• Current opinion suggests sling immobilisation and early active motion as soon as pain is relieved.
• If there is associated fracture of the coronoid or elbow instability due to an injured medial collateral ligament, current literature recommends excision and replacement with a prosthesis
• Metallic head prosthesis are preferred to silastic as silastic implants have been associated with material failure and particle synovitis with early failure.

Type IV Fracture-dislocations

• The ulna must be primarily reduced and stability restored to the radio-humeral articulation.
• The medial collateral ligament is examined for stability. If the elbow is unstable in the first 30 degrees of flexion, a medial collateral ligament repair or reconstruction is necessary.
• If the head fracture is a Mason type II an ORIF is necessary
• If the radial head needs to be excised replacement is considered.

Implant Options for ORIF

• Mini fragment plates and 2 mm/2.7 mm screws.
• Herbert screws
• Fixed angle locking plates are now used for comminuted fractures of the radial head.
• Bone allograft may be necessary in segmental fractures with bony compaction or bone loss during exposure.
• Designed for fractures where the radial head is salvageable but traditional fixation is inadequate, the Mayo Clinic Congruent Radial Head Plate may be an option

Radial head replacement
Main Indications for a radial head replacement are

• Type III / IV fractures and fracture-dislocations
• Large displaced coronoid fractures which make the elbow unstable.
• Concurrent injury to the distal radio-ulnar joint.

The silicone Radial Head prosthesis was used in the past and can be used as temporary spacer but has largely been abandoned since it:

• Cannot withstand the high pressures in Essex-Lopresti type injuries
• Has a high failure rate associated with fracture of the prosthesis, silicone synovitis, loosening and pain, which persist even after the prosthesis is excised.

Metallic Radial Head prosthesis

• Polished cobalt-chromium, vitallium, titanium or pyrocarbon make
• The Swanson titanium head prosthesis is available in five sizes
• These are press fit implants or can be cemented
• The cobalt-chromium prosthesis available from Wright medical technologies have up to 15 sizes and also have a bipolar-type function to give movement between the implant-bone interface and the radio-capitellar joint.
• Prosthesis with collars are available for cases with loss of radial neck.

Recent articles demonstrating outcomes from various interventions:
1. Open Reduction and Internal Fixation Compared With Excision for Unstable Displaced Fractures of the Radial Head. Lindenhovius AL, Felsch Q et al. J Hand Surg [Am]. 2007 May – June;32(5):630-636.

PURPOSE: To determine if excision of the radial head for treatment of an unstable, displaced fracture is associated with a higher rate of early complications or late arthrosis as compared with open reduction and internal fixation (ORIF). METHODS: Unstable, displaced fractures of the radial head treated with either excision (15 patients) or ORIF (13 patients) were compared. Implants were removed routinely during the study period. Three patients had instability after radial head excision: 2 were treated in a cast and 1 had temporary pinning of the ulnohumeral joint. Two patients in the ORIF cohort had failure of fixation that subsequently was treated with radial head excision: 1 had early hardware loosening and 1 developed a nonunion. RESULTS: At the 1-year follow-up evaluation there were no significant differences in the flexion or rotation arc. An average of 17 years after injury there was no significant difference in the flexion arc or rotation arc. One result was rated as unsatisfactory in each cohort according to the Mayo Elbow Performing Index. The average Disabilities of the Arm, Shoulder, and Hand (DASH) score was 5 points in the ORIF cohort and 15 points in the excision cohort. Eight patients in the excision cohort had arthrosis (5 mild, 2 moderate, 1 severe) compared with 2 patients in the ORIF cohort (1 mild, 1 moderate). CONCLUSIONS: Open reduction and internal fixation of an unstable, displaced fracture of the radial head occasionally fails, but it seems to reduce the risk of subsequent elbow dislocation and to protect against long-term arthrosis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

2. Reconstruction of Mason type-III and type-IV radial head fractures with a new fixation device: 23 patients followed 1-4 years. Koslowsky TC, Mader K et al. Acta Orthop. 2007 Feb;78(1):151-6.

BACKGROUND: Treatment options in radial head fractures of Mason types III and IV range from open reduction and internal fixation (ORIF) to radial head resection with or without prosthetic replacement. PATIENTS: In a prospective study, the radiographic and clinical outcome was evaluated in 23 patients (age median 51 years) with 23 complex radial head fractures median 2 (1-4) years after ORIF using a new fixation device (FFS; Orthofix). 14 Mason type-III fractures with 2 concomitant olecranon fractures and 1 ulnar nerve lesion, and 11 type-IV fractures with 2 olecranon fractures and 2 fractures of the coronoid process were treated. 2 patients were lost to follow-up. In 7 cases of joint instability, an elbow fixator with motion capacity was applied after ORIF of the radial head. RESULTS: No radial head resection was necessary. No secondary dislocations or nonunion occurred. The Morrey elbow score was excellent in 8 and good in 4 Mason type-III fractures and excellent in 5, good in 3, and fair in 3 Mason type-IV fractures. INTERPRETATION: Reconstruction of comminuted radial head fractures can be performed with this device and radial head resection can be avoided.

3. Open reduction and internal fixation of fractures of the radial head. Ring D, Quintero J, Jupiter JB. J Bone Joint Surg Am.2002 Oct;84-A(10):1811-5.

BACKGROUND: The purpose of this retrospective study was to analyze the functional results following open reduction and internal fixation of fractures of the radial head and to determine which fracture patterns are most amenable to this treatment. METHODS: Fifty-six patients in whom an intra-articular fracture of the radial head had been treated with open reduction and internal fixation were evaluated at an average of forty-eight months after injury. Thirty patients had a Mason Type-2 (partial articular) fracture, and twenty-six had a Mason Type-3 (complete articular) fracture. Twenty-seven of the fifty-six fractures were associated with a fracture-dislocation of the forearm or elbow or an injury of the medial collateral ligament. Fifteen of the thirty Type-2 fractures were comminuted. Fourteen of the twenty-six Type-3 fractures consisted of more than three fragments, and twelve consisted of two or three fragments. The result at the final evaluation was judged to be unsatisfactory when there was early failure of fixation or nonunion requiring a second operation to excise the radial head, <100 degrees of forearm rotation, or a fair or poor rating according to the system of Broberg and Morrey. RESULTS: The result was unsatisfactory for four of the fifteen patients with a comminuted Mason Type-2 fracture of the radial head; all four fractures had been associated with a fracture-dislocation of the forearm or elbow, and all four patients recovered <100 degrees of forearm rotation. Thirteen of the fourteen patients with a Mason Type-3 comminuted fracture with more than three articular fragments had an unsatisfactory result. In contrast, all fifteen patients with an isolated, noncomminuted Type-2 fracture had a satisfactory result. Of the twelve patients with a Type-3 fracture that split the radial head into two or three simple fragments, none had early failure, one had nonunion, and all had an arc of forearm rotation of > or =100 degrees. CONCLUSIONS: Although current implants and techniques for internal fixation of small articular fractures have made it possible to repair most fractures of the radial head, our data suggest that open reduction and internal fixation is best reserved for minimally comminuted fractures with three or fewer articular fragments. Associated fracture-dislocation of the elbow or forearm may also compromise the long-term result of radial head repair, especially with regard to restoration of forearm rotation.

4. Open reduction and internal fixation of comminuted fractures of the radial head using low-profile mini-plates. Ikeda M, Yamashina Y, Kamimoto M, Oka Y. J Bone Joint Surg Br. 2003 Sep;85(7):1040-4.

Between 1996 and 2000, we treated ten patients with severely comminuted fractures of the radial head using low-profile mini-plates. Their mean age was 42 years (24 to 71). Three fractures were Mason type III and seven were Mason-Johnston type IV. At a mean follow-up of 28.5 months (15 to 44), all fractures had united. The plates were removed in nine patients. No patient had difficulty with daily activities or symptoms of instability of the elbow. The mean range of flexion of the elbow was from 7 degrees to 135 degrees, with 74 degrees of supination and 85 degrees of pronation. According to the Broberg and Morrey functional elbow index, the mean score was 90.7 points (73 to 100), and the outcome was excellent in three patients, good in six and fair in one. These results compare favourably with those reported previously. The technique is applicable to severely comminuted fractures of the radial head which otherwise would require excision.

5. Management of Mason type-III radial head fractures with a titanium prosthesis, ligament repair, and early mobilization. Surgical technique. Bain GI, Ashwood N, Baird R, Unni R. J Bone Joint Surg Am. 2005 Mar; 87 Suppl 1(Pt 1):136-47.

BACKGROUND: Radial head fractures often occur in association with other elbow fractures and soft-tissue injuries. Radial head replacement is indicated for irreparable radial head fractures associated with elbow instability. The purpose of this study was to analyze the results after treatment of such injuries with a titanium radial head prosthesis, repair of torn collateral ligaments, and early mobilisation of the elbow. MATERIALS: Sixteen patients with sixteen Mason type-III radial head fractures and collateral ligament injury were treated with use of a titanium radial head prosthesis over a five-year period at the Royal Adelaide Hospital and Modbury Public Hospital in South Australia. The surgery was performed acutely in ten patients and was delayed an average of thirty-seven days (range, fifteen to seventy-nine days) in six. All patients were followed clinically and radiographically for a mean of 2.8 years (range, 1.2 to 4.3 years). RESULTS: Eight patients had an excellent result; five, a good result; and three, a fair result, according to the Mayo Elbow Performance Score. The three fair results occurred in patients with delayed surgery. The mean flexion contracture was 15 degrees (range, 0 degrees to 42 degrees ), with an average loss of 10 degrees (range, 0 degrees to 25 degrees ) of full flexion compared with that of the contralateral elbow. Both pronation and supination decreased an average of 12 degrees (range, 0 degrees to 45 degrees ) compared with that of the contralateral forearm. CONCLUSIONS: The results of treatment of Mason type-III radial head fractures with a monoblock titanium radial head prosthesis and soft-tissue reconstruction are satisfactory. Early mobilisation of the elbow is important for the restoration of elbow range of motion and function.

6. Vitallium radial head prosthesis for acute and chronic elbow fractures and fracture-dislocations involving the radial head. Chapman CB, Su BW, Sinicropi SM, Bruno R, Strauch RJ, Rosenwasser MP. J Shoulder Elbow Surg. 2006 Jul-Aug;15(4):463-73.

This retrospective study aims to evaluate the radiographic, functional, and patient-derived outcomes of 16 patients who each received a Vitallium radial head prosthesis for unreconstructable acute fractures of the radial head, as well as previously treated fractures of the radial head associated with residual instability, pain, and stiffness. Follow-up averaged 33 months. A trend toward greater disability and poorer motion was noted in the delayed treatment group compared with the acute replacement group. Overall, the results were excellent in 5 patients, good in 10, and poor in 1, as determined by the Mayo Elbow Performance Score. All elbows were stable at follow-up, and no patient reported wrist pain. Four required further operative treatment of their elbow injuries. Metallic radial head arthroplasty yields satisfactory results in acute unreconstructable radial head fractures or as a salvage procedure for previously treated radial head fractures.

Tips/Tricks to treat radial head fractures:

1. Careful evaluation of the fracture configuration using radiographs, CT scanning and fluoroscopy
2. Herbert screws are preferred to bulky implants ensuring that the screws are countersunk to ensure that neither the tip nor the tail are protruding out of the rim which may limit rotation
3. For more comminuted fractures consider prosthetic arthroplasty
4. Make the osteotomy cut for the prosthesis perpendicular to the radial shaft with the elbow in extension and the forearm supinated
5. Silastic implants are no longer preferred due to complications
6. Titanium, cobalt-chrome or vitallium implants are preferred and choice may be dependent on availability
7. Counsel the patient on the short-term and the long-term outcomes of arthroplasty based on evidence available to date
8. Allograft arthroplasty is under trial and as of yet unavailable nor FDA-approved for these injuries

Recommended further reading:

1. Morrey BF. Radial head fracture. In: Morrey BF, ed. The Elbow and its Disorders. 3rd ed. Philadelphia, Pa: WB Saunders; 2000:341-364.
2. Mason ML. Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg. 1954; 42:123-132.
3. Pan WT, Born CT, DeLong WG Jr. Fractures and dislocations involving the elbow joint. In: Dee R, ed. Principles of Orthopaedic Practice. 2nd ed. New York, NY: McGraw-Hill; 1997:411-421.
4. Morrey BF. Current concepts in the treatment of fractures of the radial head, the olecranon, and the coronoid. Instr Course Lect. 1995; 77:316-327.
5. Sharpe F, Kuschner SH. Radial head fractures. In: Baker CL Jr, Plancher KD, eds. Operative Treatment of Elbow Injuries. New York, NY: Springer-Verlag Inc; 2001:207-223.
6. Amis AA, Miller JH. The mechanisms of elbow fractures: an investigation using impact tests in vitro. Injury. 1995; 26:163-168.
7. Schatzker J. Fractures of the radial head. In: Schatzker J, Tile M, eds. The Rationale of Operative Fracture Care. 2nd ed. Germany: Springer-Verlag; 1996:131-135.
8. Davidson PA, Moseley JB Jr, Tullos HS. Radial head fracture. A potentially complex injury. Clin Orthop Relat Res. 1993; 297:224-230.
9. 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; 31:51-56.
10. Morgan SJ, Groshen SL, Itamura JM, Shankwiler J, Brien WW, Kuschner SH. Reliability evaluation of classifying radial head fractures by the system of Mason. Bull Hosp Jt Dis. 1997; 56:95-98.

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