Radial Head Fractures

Introduction

Radial head fractures are seen in 20% of elbow fractures. It may involve the radial head, radial neck or both. It may either be an isolated injury or associated with other fractures or ligamentous injury. Treatment depends on the type of fracture, amount of displacement, comminution and associated injuries. Previously radial head excision was a popular treatment, now it is being replaced by open reduction and internal fixation or radial head replacement. The assessment of these common fractures and treatment have evolved with better understanding of the anatomy and biomechanics of radial head and the development of evidence based guidelines.

Anatomy

Proximal radius consists of the radial head and the neck. The proximal surface of radial head is concave and articulates with the convex articular surface of capitellum. Radial head articulates with the capitellum of humerus. The rim of the radial head articulated with the lesser sigmoid notch of ulna. The radial head is elliptical in shape and the long axis is perpendicular to the lesser sigmoid notch in the  position of neutral rotation of the forearm. The radial head is variably offset 60 to 280 from the long axis of the radius with the average of 16.80. The mean diameter of the radial head is 22+/-3 mm. The mean radial neck-shaft angle is 7°+/-3°

Stability to the radial head is provided by the lateral collateral ligament complex and the annular ligament. Posterolateral rotatory stability of the elbow is provided by the lateral ulnar collateral ligament and it should be protected during surgery. Lateral ulnar collateral ligament is attached to the lateral epicondyle of humerus proximally and to the ulna distally, behind the posterior attachment of annular ligament on the crista supinatoris. Annular ligament is composed of superior and inferior oblique bands. The axial stability of forearm is provided by the radio-capitellar articulation, interosseous ligament and the ligaments of the distal radioulnar ligament.

Biomechanics

The functions of the radial head are the following.

  1. Motion at the elbow and forearm by articulation with capitellum and lesser sigmoid notch.
  2. Secondary stabilizer of elbow against valgus instability. Primary stabilizer is the medial collateral ligament.
  3. Axial stability of forearm along with interosseous ligament and the ligaments of the distal radioulnar joint.
  4. Transmits 60% of load across the elbow. Load is more in the extended and pronated  position of elbow than in flexion.

Mechanism of Injury

Typically occur from a fall on the outstretched hand. Axial loading along with valgus force is thought to be important in the development of comminuted fractures. Failure of the lateral collateral ligament complex and subluxation of radial head can lead to shear fractures involving the anterolateral part of radial head. Fractures of the anterolateral lip of radius are the most common radial head fracture pattern.

Epidemiology

Proximal radius fracture is the most common elbow fracture. It accounts for about 5% of all fractures and 20% of elbow fractures. It may be an intra-articular radial head fracture or an extra-articular fracture of the radial neck. Radial head fractures are 7 times more frequent than the radial neck fractures. The incidence in male and females is equal but the injury in males is comparatively more severe. It may be an isolated injury, but about one third are associated with other fractures or ligament injuries. About 10% of those with undisplaced fractures, 50% of those with displaced fractures and three fourth of those with comminuted fractures are associated with other elbow injuries.  About 10% will have a coronoid fracture and 15-20% will have associated dislocation.

Clinical Features

Clinical features depend on the severity of injury and the associated injury. Patients with undisplaced fracture and no associated injuries often have only minimal symptoms. More serious injuries present with pain on the lateral aspect of elbow. Those with associated injuries or dislocation present with severe pain, deformity, swelling and severe restriction of elbow and forearm movements.

Carefully look for ecchymosis and swelling of medial and lateral aspects of elbow indicating ligamentous injury.  Palpate the distal humerus, medial and lateral aspects of elbow, radial head, olecranon, radial shaft, ulnar diaphysis, interosseous membrane, distal radioulnar joint, lower end of radius and the ulnar styloid. Tenderness over the forearm and ulnar styloid should alert about the possibility of an Essex Lopresti lesion. Assess the elbow movement and forearm rotation. If there is any restriction, aspirate the joint to reduce intra-articular pressure, inject local anesthetic agent and reassess the range of movement. Mechanical block to motion is an indication for surgery. Gentle assessment of the medio-lateral stability of elbow is a must as it may lead to fracture displacement. Assess the shoulder and wrist for any injury. Rule out vascular compromise, nerve injury and compartment syndrome.

Imaging

Antero-posterior, lateral and oblique vies of the elbow should be taken with the beam centered over the radio-capitellar joint. X-rays of shoulder and forearm with wrist should be taken to rule out associated injuries. Ulna variance should be assessed to rule out axial instability on bilateral wrist x-rays taken in neutral rotation. X-rays should be carefully evaluated for associated lateral column injuries, dislocation and periarticular injuries. Identify the number, location and size or fracture fragments, assess the magnitude of displacement. Complex injuries and displaced fractures should be further assessed by CT scans. CT with 3D reconstruction is an excellent method for the evaluation of complex injuries. If ligamentous injury is suspected then MRI scan is warranted. Ultrasound scan of the forearm is helpful in detection of interosseous ligament injury.

Classification

Mason classification

Type I – Partial head fractures without displacement

Type II – Partial head fractures with displacement

Type III – Comminuted fractures involving the whole head

Type IV – Radial head fracture associated with an elbow dislocation (Added by Johnston).

Broberg and Morrey modification is inclusion of radial neck fractures and definition of displaced fractures as fracture displacement >2mm and fragment size >30% of the articular surface.

Mason Classification as Modified by Hotchkiss by adding treatment recommendations

I – Minimal fracture displacement, no mechanical block to forearm rotation, intra-articular displacement less than 2 mm are treated by nonoperative treatment.

II –  Fracture displaced more than 2 mm or angulated, possible mechanical block to forearm rotation are treated by open reduction and internal fixation.

III – Severely comminuted fracture, with mechanical block to motion are treated by radial head arthroplasty.

IV – Radial fracture with associated elbow dislocation.

Mayo Extended Classification

Type I – Non-displaced.

Type II – Displaced more than 2 mm.

Type III- Comminuted,  non-reconstructible  radial  head.

The Mayo extended classification then adds a suffix to the fracture type to show any associated lesion.

Suffix

‘c’ – Associated coronoid fracture. ‘C’ – If operative treatment was done.

‘o’ – Associated olecranon fractures. ‘O’ – If operative treatment was done.

‘m’ for medial collateral ligament (MCL) injury. ‘M’ – If operative repair was done.

‘l’  for  the  lateral  collateral  ligament  (LCL) injury. ‘L’ – If operative repair was done.

‘d’ for longitudinal distal radio-ulnar joint (DRUJ)  dissociation. ‘D’ – If operative treatment done.

‘X’ added for radial head excision.

‘F’ if radial head was fixed and

‘A’ if arthroplasty was done.

Mayo Extended Classification

  Mayo Classification

Management

The factors that determine the treatment are the following.

A. Radial head fracture configuration

1.   Partial or completely articular

2.   Fragment size –  <33% or more

3.   Comminution – ❤ or more fragments

4.   Impaction

5.   Displacement – <2mm or more

6.   Radial neck involvement

B. Radiocapitellar alignment

C. Associated fractures and ligamentous injury

D. Block to elbow and forearm range of movement

E. Elbow or forearm instability

F. Bone quality

Indications for surgery

  1. Displacement more than 2mm
  2. Restriction of range of movement
  3. Elbow or forearm instability
  4. Open fractures
  5. Polytrauma

Guidelines

  • Fragment size if less than 33% of the radial head can be excised. If more than 33% it should be fixed
  • Comminution with more than 3 fragments is associated with poor outcome with ORIF. Either excise or replace
  • More than 2 mm displacement is considered to be an indication for surgery
  • Associated fractures of capitellum, coronoid, olecranon and distal radius need surgery
  • Block to elbow movement or forearm rotation is an indication for surgery
  • Elbow and forearm instability is an indication for surgery

In fracture-dislocations of elbow; fixation/reconstruction is essential to restore coronal plane stability of elbow, to reduce the reliance on ulnar collateral ligament and to prevent proximal migration of radius. The options available for treatment are non-operative treatment, fragment excision, radial head excision, arthroscopic assisted reduction and fixation, open reduction and internal fixation and radial head replacement.

Nonoperative treatment

Indicated in undisplaced fractures and in minimally displaced (<2mm) fractures involving <33% of the head with no mechanical block to movement. Aspirate the joint under aseptic precautions, give a cuff & collar sling and start active ROM within 2-3 days once pain subsides. Avoid weight lifting and strenuous activities for 4-6 weeks. Take an x-ray at 2 weeks to rule out displacement. After 6 weeks usually functional ROM is attained, if not physiotherapy is given. Delayed excision may be needed if there are persistent pain and limitation of range of motion.

Surgical approaches

Anterior Henry approach and posterior Thomson approach allow exposure of proximal radius and the posterior interosseous nerve. Kocher approach between anconeus and extensor carpi ulnaris (ECU) is the most commonly used approach for radial head surgery. A major disadvantage of Kocher approach is inability to expose the posterior interosseous nerve (PIN). The PIN runs between the 2 heads of the supinator in close proximity to the radial neck. It is about 3.8 cm distal to the articular surface in pronation. To protect the PIN, the following steps should be taken.

  1. The forearm should be kept in full pronation during the procedure.
  2. Identify the interval between the ECU and anconeus by recognizing the fan-shaped direction of the fibers of anconeus, which are horizontal proximally and vertical distally.
  3. The supinator muscle should be released from its posterior edge close to the ulna.

Steps in the surgery are as following.

1)      Anesthesia

a)      Regional anesthesia

b)      General anesthesia

2)      Position

a)      Supine position with the arm on arm board and a pillow over the interscapular area.

b)      Lateral position with arm supported over a bolster

3)      Incision

a)      Lateral incision centered over the lateral epicondyle

b)      Posterior midline incision in presence of other elbow injuries raising a full thickness flap

4)      Deep dissection

a)      Kocher approach

i)       Useful for exposure of lateral and posterior parts of the radial head.

ii)      Uses the interval between the anconeus and extensor carpi ulnaris (ECU).

iii)     Interval between ECU and anconeus identified by diverging direction of muscle fibers, fat pad and small perforators.

iv)     Elevate the ECU anteriorly off the lateral ligament complex and incise the annular ligament in the midlateral plane to avoid injury to lateral ulnar collateral ligament (LUCL). It is better to do a Z capsulotomy for better repair after plate fixation or arthroplasty.

v)      Do not elevate the anconeus posteriorly to protect the LUCL.

vi)     Often the LCL is ruptured and the radial head can be exposed through that gap. LCL should be repaired at the end of the procedure.

vii)   If needed LCL may be released and reattached at the end of the procedure.

b)      Kaplan approach

i)       Useful for exposure of lateral and posterior parts of the radial head.

ii)      Uses the interval between the extensor carpi radialis and extensor carpi ulnaris (ECU).

iii)     Elevate the ECU posteriorly off the lateral ligament complex and incise the annular ligament in the midlateral plane to avoid injury to lateral ulnar collateral ligament (LUCL).

iv)     Chance of posterior interosseous nerve palsy is reduced by keeping the forearm pronated.

c)      Hotchkiss Approach

i)       Exposure through the fibers of extensor digitorum communis.

ii)      Useful for exposure of anterolateral lesions.

iii)     Radial head exposed through the fibers of EDC.

iv)     Higher chance of posterior interosseous nerve palsy, which is avoided by keeping the forearm pronated.

Open reduction and internal fixation

About 2700 of proximal radius articulates with the lesser sigmoid notch; any protruding implants in this region will cause impingement and restriction of movement. Implants that project above the articular surface should be placed in the safe zone described by Smith and Hotchkiss. It is the posterolateral quadrant of the radial head which doesn’t articulate with the lesser sigmoid notch. It is the area of head that corresponds to the area between the radial styloid and Lister’s tubercle of distal radius. Safe zone is identified by the following method.

  • Keep the forearm in neutral rotation.
  • Mark the mid-lateral point of the radial head.
  • 450 arc anterior and posterior to the mid-lateral point is the safe zone.

Fixation may be done for Mason II and selected Mason III fractures. The implants used for fixation in Mason II fractures may be conventional bone screws (2.7 mm/2.0 mm/1.5 mm), variable pitch headless compression screws small threaded Kirschner wires and absorbable pins or screws. Mason III fractures need fixation by low profile mini-fragment plate and screws, small fragment T or L plates, cross-cannulated screws or pre-contoured anatomic radial head locking plates. In comminuted fractures, it is important to avoid excessive compression by screws.

Radial head arthroplasty

In presence of severe comminution with >3 fragments, fixation may not be possible and radial head excision is done. After excision elbow and forearm stability is tested. If stable, simple excision is sufficient. Arthroplasty is indicated in presence of forearm and/or elbow instability in fractures involving >30% of the radial head which cannot be satisfactorily reduced and stably fixed.

Aim of arthroplasty is to restore the radial head height, size and radial head-neck offset to achieve radiocapitellar and axial stability of forearm. Correct sizing is essential to prevent restriction of movement due to overstuffing and instability due to under-sizing. The resected head can be used as a template for sizing. During trials, the diameter, thickness, congruency and tracking should be assessed to estimate the proper fit. Normally when the forearm is in neutral rotation, the level superior edge of articular surface of lesser sigmoid notch and the radial head will be at the same level. Under C-arm the alignment of DRUJ, ulnar variance and symmetry of lateral and medial aspects of the ulnohumeral joint should be assessed for proper sizing.

Radial head prostheses are currently available in a number of options. It may be unipolar or bipolar, cemented or uncemented and monoblock or modular. It may be round or elliptical (Anatomic).  Anatomic radial head prosthesis has an elliptical shape and it should be inserted with the long axis perpendicular to the lesser sigmoid notch, while keeping the forearm in neutral rotation.

Radial head excision

Radial head excision may be partial or total. Partial excision of >25% of radial head should be avoided. It may be required in presence of significantly comminuted and displaced fractures which cannot be reconstructed. But simple excision should be done only if the elbow and the forearm are stable. Hence after excision the stability of the forearm should be assessed and if unstable the radial head should be replaced. It may be associated with pain, instability, cubitus valgus, proximal migration of radius, DRUJ symptoms, weakness of grip and ulnohumeral arthritis.

Postoperative care

Long arm splint is given for 7-10 days. Abduction of shoulder avoided for 6 weeks if lateral collateral ligament was repaired. Once sutures are removed active assisted mobilization is started. Strengthening exercises started once there is radiological evidence of union.

Outcome

Outcome depends on the type of fracture and the associated lesions. 85% to 95% good results have been reported in undisplaced fractures managed nonoperatively with early motion. In displaced fractures, surgical treatment provides significantly better results than nonoperative treatment. Radial head prosthesis restores stability when the stability is compromised, but some loss of motion and strength is common and long term results are not yet known. In type III fractures, the results of radial head arthroplasty are superior to ORIF.

Complications

Most common complication is restriction of range of movement. Degeneration of radiohumeral articulation is also common. Secondary displacement of type I fractures can occur. Nonunion is rare. Posterior interosseous nerve palsy can occur, but usually recovers. Surgical site infection may require implant removal and debridement. Heterotopic ossification can occur. Capitellar erosion may occur after radial head replacement. Instability can occur after radial head excision. Loosening, overstuffing and radial head subluxation may be seen after radial head replacement.

Future Directions

From the outcome studies the importance of associated fractures and ligamentous injury is now clearly understood. But present methods of assessment of instability are nonspecific and inaccurate. With more specific and precise methods to assess instability and clearer cut guidelines for treatment will make the treatment more evidence based and reproducible.

With better understanding of anatomy of proximal radius and identification of the three dimensional pathoanatomy of common fracture patterns, development of fracture specific implants are likely to provide better methods of fixation. Anatomic radial head prosthesis is already available, but their advantages over the conventional designs need long term studies.

Summary

Radial head is essential for valgus stability of elbow, axial stability of forearm and for load transfer across the elbow. Radial head fractures are the commonest of elbow fractures.  They are often associated with ligamentous injury and other periarticular fractures which have significant influence over the outcome. In presence of elbow and forearm instability, the radial head should either be fixed or replaced.

Further Reading

1)      Mason ML. Some observations on fractures of the head of the radius with a review of one hundred cases. Br J Surg. 1954 Sep;42(172):123-32.

2)      Broberg MA, Morrey BF. Results of treatment of fracture-dislocations of the elbow. Clin Orthop Relat Res. 1987 Mar;(216):109-19.

3)      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 Jun 1;31:51-6.

4)      Hotchkiss RN. Displaced fractures of the radial head: internal fixation or excision? J Am Acad Orthop Surg 1997;5(1):1–10.

5)      O’Driscoll SW, Bell DF, Morrey BF. Posterolateral rotatory instability of the elbow. J Bone Joint Surg. Am 1991;73(3):440–6.

6)      Tornetta P 3rd, Hochwald N, Bono C, Grossman M. Anatomy of the posterior interosseous nerve in relation to fixation of the radial head. Clin Orthop Relat Res.1997 Dec;(345):215-8.

7)      Schimizzi A, MacLennan A, Meier KM, Chia B, Catalano LW 3rd, Glickel SZ. Defining a safe zone of dissection during the extensor digitorum communis splitting approach to the proximal radius and forearm: an anatomic study. J Hand Surg Am. 2009 Sep;34(7):1252-5.

8)      Soyer AD, Nowotarski PJ, Kelso TB, et al. Optimal position for plate fixation of complex fractures of the proximal radius: a cadaver study. J Orthop Trauma 1998;12(4):291–3.

9)      Smith GR, Hotchkiss RN. Radial head and neck fractures: anatomic guidelines for proper placement of internal fixation. J Shoulder Elbow Surg. 1996 Mar-Apr; 5(2 Pt 1):113-7.

10)   Smith AM, Morrey BF, Steinmann SP. Low profile fixation of radial head and neck fractures: surgical technique and clinical experience. J Orthop Trauma 2007;21(10):718–24

11)   Yishai Rosenblatt, George S. Athwal, Kenneth J. Faber. Current Recommendations for the Treatment of Radial Head Fractures. Orthop Clin N Am 39 (2008) 173–185.

12)   Van Glabbeek F, Van Riet R, Verstreken J. Current concepts in the treatment of radial head fractures in the adult. A clinical and biomechanical approach. Acta Orthop Belg 2001;67(5):430–41.

13)   van Riet RP, Van Glabbeek F, Morrey BF. Radial head fracture. In: Morrey BF, editor. The elbow and its disorders. 4th ed. Philadelphia, PA: Saunders Elsevier; 2009. p. 359–81.

14)   James T. Monica, Chaitanya S. Mudgal. Radial Head Arthroplasty. Hand Clin 26 (2010) 403–410

Scaphoid Fractures and Nonunions

Epidemiology

  • Account for 3-4% of all fractures.
  • Second most common fracture of the upper limb after distal radius fractures.
  • Most commonly missed fracture in the body.
  • Highest incidence seen between 20-30 years of age.
  • Male female ratio is 2:1.

Anatomy

  • Got its name from the Greek word “skaphe” which means boat.
  • 4 Parts
    • Tubercle
    • Distal pole
    • Waist
    • Proximal pole
  • 80% covered by articular cartilage. Its implications are that 1, articular cartilage may be damaged by screw insertion, 2, Absence of periosteum results in minimal callus and 3, poor blood supply predisposes to osteonecrosis.
  • Tubercle of scaphoid is overlaid by flexor carpi radialis (FCR)
  • Male scaphoid is longer. Hence longer and larger screws may be required in males.
  • Trabecular density is maximum at the proximal pole and thinnest at the waist. Waist is the commonest site of fracture.
  • Blood vessels enter through the dorsal ridge and tuberosity. 70-80% of blood supply enters through the dorsal ridge.
  • Scaphoid links the proximal and the distal carpal rows.
  • There is significant intercarpal motion between scaphoid and lunate, which questions the validity of present kinematic models of carpal motion.
  • Scaphocapitate and scaphotrapezial ligaments control the movements of the distal pole.

Imaging

  • X-rays needed for diagnosis are PA view, Lateral view, Semipronated oblique view, Semisupinated oblique view and AP in ulnar deviation.
  • Intrascaphoid angle is measured by first drawing a line connecting the widest part of proximal and distal poles, then draw lines perpendicular to it. The angle formed by their intersection is the intrascaphoid angle.
  • Normal intrascaphoid angle is 400 in the coronal plane and in the sagittal plane it is 300.
  • Intrascaphoid angle more than 350 indicates humpback deformity.
  • Normal height length ratio is greater than 0.65.
  • Sensitivity of CT for detection of an undisplaced fracture is 89% and specificity is 91%.
  • MRI is the most sensitive and specific investigation for detection of occult fractures.
  • Normal scapholunate interval is 9mm at 7years of age and 3mm at 15 years of age.

Classification

Russe Classification

  • Horizontal Oblique
  • Transverse
  • Vertical Oblique

Herbert & Fisher Classification

A. Stable Acute Fractures

A1- Tuberosity fractures

A2- Incomplete waist fractures

B. Unstable Acute Fractures

B1- Oblique fractures of distal third

B2- Displaced waist fractures

B3- Proximal pole fractures

B4- Trans-scaphoid Perilunate instability

B5- Comminuted fractures

C. Delayed union (After 6 weeks of immobilization)

D. Established nonunions

D1- Fibrous nonunions

D2- Sclerotic

Distal pole fractures can be of 2 types

  1. Avulsion fractures of the volar radial lip
  2. Impaction fracture of the volar half

Management

Management depends on the fracture pattern, reduction and bone quality. It also depends on the patient’s occupation and the need to return to work early. Those who need to return to work early are currently treated by percutaneous screw fixation.

General guidelines

  • Undisplaced distal pole fractures are treated by 4-6 weeks of immobilization.
  • Undisplaced waist fractures are treated by immobilization and percutaneous screw fixation.
  • Undisplaced waist fractures are treated by 6 weeks of long arm scaphoid cast followed by 6 weeks of short arm scaphoid cast.
  • Displaced fractures are treated by internal fixation by screws.

Indications for surgery

  • Displaced fractures.
  • Unstable fractures.
  • Associated carpal injury.
  • Associated distal radius fracture.
  • More than 3-4 weeks delay in initial presentation.
  • Undisplaced fractures in those who want early return to work. Some authors have reported high incidence of complications with percutaneous fixation.

Definition of displaced and unstable fractures

According to Cooney

  • More than 1 mm displacement.
  • More than 100 angular displacement.
  • Fracture comminution.
  • Radiolunate angle more than 150.
  • Scapholunate angle more than 600.
  • Intrascaphoid angle more than 350.

Approaches to scaphoid fixation

  • The approach to fix may be dorsal or volar.
  • These approaches may be open, mini-open or percutaneous.
  • Proximal pole fractures need dorsal approach and distal third fractures are approached volar.
  • Waist fractures may be approached dorsal or volar.
  • Volar approaches need osteotomy of the volar radial lip of trapezium to expose the entry point; hence dorsal approach is becoming more popular.
  • Dorsal approaches carry the risk of damage to blood supply entering the scaphoid through the dorsal ridge.
  • Current best practice for the treatment of displaced acute scaphoid fractures is by percutaneous approach

Indications for open approach

  • Scaphoid nonunions
  • Irreducible fractures
  • Comminuted fractures.

Volar open approach

  • Incision from a point 2 cm proximal to the scaphoid tuberosity in line with FCR and distally in line with thumb metacarpal.
  • Open the sheath of FCR and retract the tendon medially.
  • Avoid dissection on the ulnar side of FCR to avoid injury to palmar branch of median nerve.
  • Incise the dorsal sheath of FCR.
  • Superficial branch of radial artery may need cauterization.
  • Incise the capsule between long Radiolunate ligament and radioscaphocapitate ligaments.
  • Avoid dissection on the radial side of scaphoid.

Volar percutaneous approach (Haddad and Goddard)

  • Supine position with thumb suspended in Chinese finger trap.
  • Under C Arm identify and mark scaphotrapeziotrapezoid (STT) joint.
  • Reduce the fracture under C arm control.
  • Make a longitudinal stab incision 1 cm distal to STT joint.
  • Put the guide wire towards the centre of proximal pole and aim towards the Lister’s tubercle

Dorsal open approach

  • 3-4 cm incision proximally and distally in line with the III metacarpal.
  • Plane of dissection is between 3rd and 4th extensor compartments.
  • Retract Extensor pollicis longus (EPL), Extensor carpi radialis longus (ECRL) and Extensor carpi radialis brevis (ECRB) radially and extensor digitorum communis (EDC) medially.
  • T shaped capsulotomy done. Transverse limb at the dorsal edge of distal radius and vertical limb radial to the dorsal intercarpal ligament.
  • Avoid accidental injury to the dorsal part of scapholunate interosseous ligament (SLIL).
  • Avoid injury to blood vessels entering the scaphoid through the dorsal ridge.

Dorsal percutaneous approach (Slade technique)

  • Supine position with the hand on a hand table with C Arm.
  • Reduce the fracture.
  • Forearm pronated.
  • With image guidance mark scapholunate interval.
  • Pronate and flex the wrist to 450 till the scaphoid is seen as a circle with overlap of proximal and distal poles.
  • Make a stab incision oven the centre of the circle.
  • Bluntly dissect with a haemostat up to the bone.
  • Use a 14G IV cannula as a tissue protector during guide wire insertion.
  • Drive the K wire through the centre of the circle.
  • Starting point is 3 mm radial to the attachment of proximal membranous portion of the SLIL.
  • Aim towards a point 5 mm distal to the scaphoid tuberosity.
  • Withdraw the K wire through the volar exit point till the tip of the K wire is at the radiocarpal joint. This is to prevent breakage of wire during imaging to confirm central position of the K wire.
  • Confirm position by AP, lateral and 300 pronated lateral views.
  • Once position is confirmed, drive back the wire out through the dorsal skin so that part of the guide wire is outside both on the volar and dorsal side. This is to have control on both ends of the guide wire in case of breakage.

Dorsal Mini-open Technique

  • 1 cm long incision just to the Lister’s tubercle.
  • Open the sheath of both EPL and EDC.
  • Retract EPL radially and EDC medially.
  • Open the capsule and identify the starting point for guide wire.
  • Prevents injury to extensor tendons and other soft tissue.

Reduction of displaced fractures.

  • Longitudinal traction is given over the index and middle fingers to distract the fracture site and reduce.
  • Percutaneously K wires may be inserted into the proximal and distal fragments to act as joysticks.
  • To achieve reduction, use the joysticks to flex the proximal pole and the distal pole is extended and supinated.

Screw fixation of scaphoid

  • The key to success in screw fixation is placement of the guide wire in the central axis of scaphoid.
  • The guide wire should be in the middle third of the proximal pole in the AP and lateral views.
  • Central placement of the screw provides greater stiffness, greater resistance to displacement and greater load to failure.
  • Another wire should be inserted to prevent rotation during screw insertion in such a way that it will not interfere with the screw placement.
  • Screw should be 2-3 mm below the articular surface.
  • Screw should be 4 mm less than the measured length of scaphoid.
  • Guide wire should be adequately reamed to prevent distraction during screw insertion.
  • Reaming should stop 2 mm from the articular surface.
  • If central screw placement doesn’t provide adequate stability, then it should be augmented with a K wire.

Scaphoid Nonunions

  • Incidence of nonunion range from 5-10% in waist fractures.
  • Scaphoid compression test is done by axial compression of thumb, pain is suggestive of injury.
  • Union is indicated by progressive obliteration of fracture site and also by the development of trabeculae that cross the fracture site on serial x-rays. In case of doubt regarding union, CT scan may be useful.

Predisposing factors for nonunion.

  • Displacement more than 1 mm
  • Fracture of proximal pole
  • Vertical oblique pattern
  • Comminuted fractures
  • Associated carpal injuries
  • Delayed diagnosis
  • Inadequate immobilization
  • Osteonecrosis
  • Smoking

Bone defects in nonunion.

  • Proximal fractures have small crescentric defects
  • Distal nonunions have large triangular defects with humpback deformity
  • Humpback deformity is flexion of the distal fragment and extension of proximal fragment with associated shortening of scaphoid.
  • Extension of proximal fragment leads to extension of lunate leading to dorsal intercalated segment instability.
  • Its development depends on the position of fracture line in relation to the apex of the dorsal ridge of scaphoid.
  • Dorsal component of SLIL and dorsal intercarpal ligament are attached to the dorsal ridge
  • If the fracture is distal to the dorsal ridge; humpback deformity may occur. If proximal; attaché ligaments prevent humpback deformity.
  • Humpback deformity needs volar approach and corticocancellous wedge graft to correct the shortening and deformity. ( Fernadez technique)
  • Problem with Fernandez technique is the difficulty in screw insertion with the graft in situ.
  • Stark technique is volar approach, forceful dorsiflexion to correct the humpback deformity, cancellous grafting to maintain the correction and K wire fixation.

Geissler and Slade classification of scaphoid nonunions.

i. 4-12 week delayed presentation

ii. Fibrous union – Minimal gap, no cyst, no sclerosis

iii. Minimal sclerosis with <1 mm bone resorption

iv. Cyst formation and sclerosis with 1-5 mm bone resorption, no deformity

v. Deformity and/or cyst formation, > 5 mm bone resorption, cyst formation

vi. With radiocarpal and/or midcarpal arthritis

Special circumstances

  • Proximal pole nonunion
  • Osteonecrosis
  • Associated carpal instability

Management of nonunion depends on the duration, carpal alignment, bone loss, presence or absence of humpback deformity, carpal collapse, osteonecrosis and previous surgery.

Matte-Russe technique- Creation of a egg shaped cavity in the proximal and distal fragments and filling with cancellous graft.

Modified Matte- Russe technique- Creation of a trough and placement of two corticocancellous graft with their cortical surface facing each other.

Vascularised bone graft (VBG)

Indications

  • Proximal pole osteonecrosis
  • Displaced acute proximal pole fractures
  • Failed nonvascularised bone graft

Contraindications

  • Radiocarpal and midcarpal arthritis.
  • Damage to radial artery, I dorsal metacarpal artery or dorsal carpal arch.
  • Previous surgery on the dorsum of wrist.
  • Smokers.

Types of VBG

Pedicled based on

  • 1,2 intercompartmental supraretinacular artery (Zaidemberg).
  • Volar carpal artery (Kuhlmann).
  • Capsular VBG based on 4th extrracompartmental artery of dorsal carpal arch.
  • Vascularised thumb metacarpal graft (Bertelli).

Free VBG

  • Free iliac crest
  • Free fibula

Copyright -Dr Rajesh Purushothaman, Associate Professor of Orthopaedics, Kozhikode, Kerala, India.
Contact me at learning.orthopaedics@gmail.com