Cardiff School of Engineering

Coursework Cover Sheet

Personal Details

Student No: 1056984

Family Name: Divecha First Name: Hiren

Personal Tutor: Prof Sam Evans Discipline: MMM

Module Details

Module Name: Surgical Practice Module No: ENT547

Coursework Title: Weekend 2 Coursework - Shoulder

Lecturer:

Submission Deadline: 10/1/2012

Declaration

I hereby declare that, except where I have made clear and full reference to the work of others, this submission, and all the material (e.g. text, pictures, diagrams) contained in it, is my own work, has not previously been submitted for assessment, and I have not knowingly allowed it to be copied by another student. In the case of group projects, the contribution of group members has been appropriately quantified. I understand that deceiving, or attempting to deceive, examiners by passing off the work of another as my own is plagiarism. I also understand that plagiarising another's work, or knowingly allowing another student to plagiarise from my work, is against University Regulations and that doing so will result in loss of marks and disciplinary proceedings. I understand and agree that the University’s plagiarism software ‘Turnitin’ may be used to check the originality of the submitted coursework. Signed: …..…………………………………….………... Date: ……………………

Coursework 2 – Midshaft Clavicle

Fractures & ACJ Dislocations

Hiren Maganlal Divecha

Candidate Number: 1056984

ENT547 – Surgical Practice

Word count – 3402

Contents

1. Classify clavicle shaft fractures ....................................................................................................1

2. Discuss management of midshaft clavicle fractures with reference to biomechanics ...................3

a) Undisplaced ............................................................................................................................3

b) Displaced.................................................................................................................................3

3. Classify ACJ injuries .....................................................................................................................6

4. Critique this classification ............................................................................................................7

5. Describe the biomechanics of ACJ stabilisers ...............................................................................8

a) Static stabilisers.......................................................................................................................8

b) Dynamic stabilisers ..................................................................................................................9

6. Describe treatment options for Type IV/V ACJ injuries. Give biomechanical advantages/

disadvantages of these options ......................................................................................................... 10

7. With respect to ACJ injuries, review the literature and discuss treatment options for all groups 12

a) Type I/ II ................................................................................................................................ 12

b) Type III .................................................................................................................................. 12

c) Types IV/ V/ VI....................................................................................................................... 13

8. How would you have a Type III injury treated if it was your shoulder? How would you manage an

elite rugby player with the same acute injury? .................................................................................. 15

9. References ................................................................................................................................ 16

1

1. Classify clavicle shaft fractures

One of the earliest clavicle fracture classifications was described by Allman (Allman, 1967) and simply

grouped the fractures according to location and in descending order of incidence:

Group 1 – middle 1/3rd

Group 2 – distal to coraco-clavicular ligaments (non-union common)

Group 3 – proximal 1/3rd

Most modern classifications are based on this, but subdivide each group further. Craig’s (1990) and

Robinson’s (1998) classifications are commonly used (table 1) and take into account fracture

location, displacement, stability and joint involvement. This may make the day to day use of such

systems a bit more difficult, but including these variables allows for some guidance as to the risk of

delayed/ non-union (and of post-traumatic OA in the case of intra-articular involvement). In a

comparison of prognostic value in predicting delayed/ non-union between 5 classification systems,

O’Neill et al (2011) found that Craig’s classification had the greatest prognostic value for lateral third

fractures whilst Robinson’s classification had the greatest prognostic value for middle third fractures.

2

Robinson Craig

Type 1 (medial 1/5)

a1. Undisplaced - Extra-articular

Group I (mid. 1/3)

a2. Undisplaced - Intra-articular b1. Displaced - Extra-articular b2. Displaced - Intra-articular

Type 2 (mid. 3/5)

Group II (dist. 1/3)

Type1: Minimal displacement (inter-ligamentous)

a1. Cortical alignment - Undisplaced Type 2: Displacement secondary to fracture medial to ligaments

a2. Cortical alignment - Angulated a. Conoid and trapezoid attached

b. Conoid torn, trapezoid attached

b1. Displaced - Simple, wedge Type 3: Intra-articular

b2- Displaced - Multifrag, segmental Type 4: Ligaments attached to periosteal sleeve, displacement of prox. frag.

Type 5: Comminuted, ligaments attached to comminuted inf. frag.

Type 3 (lateral 1/5)

a1. Undisplaced - Extra-articular

Group III (prox. 1/3)

Type1: Minimal displacement

a2. Undisplaced - Intra-articular Type 2: Significant displacement (ligaments ruptured)

Type 3: Intra-articular

b1. Displaced - Extra-articular Type 4: Epiphyseal separation (paediatric)

b2. Displaced - Intra-articular Type 5: Comminuted

Table 1: Outline of Robinson's and Craig's classification systems of clavicle fractures

3

2. Discuss management of midshaft clavicle fractures with reference

to biomechanics

The goal of treatment of these injuries is to restore shoulder function to (near) normal levels.

a) Undisplaced

Undisplaced midshaft clavicular fractures can be treated non-operatively (Khan, et al., 2009). Initially,

patients are immobilised in a sling for 2-4 weeks followed by physiotherapy and active motion

thereafter. Depending on radiographic signs of union, full mobilisation can begin at 6 weeks and

contact sports at 3 months (Khan, et al., 2009) (Preston & Egol, 2009). A figure of eight bandaging

technique used to be employed, however this has not been found to affect fracture healing outcome

and can be associated with patient discomfort, axillary pressure sores and neurovascular

compromise (Andersen, et al., 1987) (Stanley, et al., 1988). In a large systematic review, the non-

union rate with non-operative treatment in undisplaced fractures was reported at 5.9% (increasing to

15% in displaced fractures) (Zlowodzki, et al., 2005).

b) Displaced

Historically, displaced clavicular shaft fractures were treated non-operatively. Amongst reasons for

this was the reported increased non-union rates following attempted ORIF (Neer, 1968) (Rowe,

1968)). More recent studies (McKee, et al., 2006) including a large prospective randomised trial by

the Canadian Orthopaedic Trauma Society (2007), have shown lower non-union rates and better

functional outcomes following ORIF for displaced midshaft clavicular fractures. Indications for

operative intervention include:

1. Open fracture/ overlying skin compromise

2. High energy injuries with more than 2 cm displacement (increased non-union risk) 16

4

3. Associated neurovascular compromise/ injury may necessitate exploration and repair followed

by fracture fixation

Relative indications include:

1. Polytrauma

2. Floating shoulder injury

3. Symptomatic mal/ non-union

Other studies have shown that non-union rates may be as high as 20% in displaced and comminuted

fractures after nonsurgical treatment and that strength and endurance deficits are more common in

these cases.36,52 These reports, in combination with a more prognostic classification system, have

led many authors to recommend acute surgical fixation for these fracture subtypes.53

Historically, K-wires and threaded pins (e.g.: Knowles pins) have been used to stabilise these fracture

types. These methods have been associated with significant complication rates, non-union and in

particular the risk of pin migration into nearby vital structures (Grassi, et al., 2001). Osteosynthesis of

midshaft clavicular fractures can be achieved with plate or intramedullary pin fixation.

Plate fixation allows for accurate reduction and absolute fracture stability through rigid fixation.

This allows early mobilisation. Use of anatomically contoured plates obviates the need for

removal of prominent hardware, usually.

Antegrade or retrograde IM pin fixation allows for relative stability but benefits from better

cosmesis and less periosteal stripping. As they are not locked, they have little rotational stability

(Golish, et al., 2008) (Renfree, et al., 2010).

Renfree et al (2010) compared IM pins with unicortically locked plates and bicortically non-locked

plates in synthetic clavicle fracture models under cantilever and 3-point bending. They concluded

that both plate constructs provided similar rigid fixation (added advantage of unicortical screws –

5

avoid plunging into underlying neurovascular structures). The IM pin was less stiff (greater

displacements) and provided little rotational stiffness. Interestingly, a clinical comparison of union

rates and functional outcomes between plate and IM fixation has reported similar good results with

no differences in complication rates (Liu, et al., 2010). A clinical comparison between locked and non-

locked plates by Cho et al (2010) similar times to union and functional outcome scores between the 2

groups, with less evidence of screw loosening in the locked group.

It remains apparent that good results may be achieved operatively, but the ideal fixation device

remains uncertain. Future work should be directed at clinically based, comparative/ controlled,

functional outcome related research in this area. An example of this is the multicentre randomised

controlled trial in progress in the UK (Longo, et al., 2011).

6

3. Classify ACJ injuries

Acromio-clavicular joint injures were originally classified by Tossy et al in 1963 (1963) and later by

Allman in 1967 (1967) into three groups. This was then expanded in 1989 to 6 groups by Williams et

al (1989) to describe the Rockwood classification (table 2), which remains in current use:

Type AC Lig CC Ligs Delto-trapezial fascia Instability Radiographic CC distance

I Sprained Intact Intact None Normal (1.1-1.3 cm)

II Torn Sprained Intact AP <25%

III Torn Torn Intact AP and vertical 25-100%

IV Torn Torn Torn Unstable (posterior displacement

into trapezius)

V Torn Torn Torn Unstable 100-300%

VI Torn Intact Torn Decreased

Table 2: Rockwood classification of ACJ injuries (AC – acromio-clavicular; CC – coraco-clavicular). Adapted from (Simovitch, et al., 2009)

Physeal separations of the distal clavicle and fractures of the base of the coracoid (CC ligaments

remain intact and attached) may be falsely described as Type III injuries. In Type IV injuries, it is

important to exclude a concomitant anterior dislocation of the sterno-clavicular joint. In Type V

injuries, the delto-trapezial fascia tears and the resulting increase in CC separation is large. The

weight of the arm results in the scapula being pulled downwards and anteriorly (unopposed pull of

serratus anterior). Type VI injuries are rare and are seen in high-energy polytrauma scenarios. The

distal clavicle dislocates inferiorly into a subacromial or subcoracoid position (can result in brachial

plexus or vascular compression/ injury). Mechanism – hyperabduction and external rotation of the

arm combined with retraction of the scapula).

7

4. Critique this classification

The Rockwood classification system defines injuries to the ACJ by increasing soft tissue damage

(table 2). Structures fail in sequence (AC ligaments, CC ligaments, delto-trapezial fascia) with

resulting increased disruption and instability of the ACJ. The classification system stratifies injuries

according to increasing energy and can therefore guide treatment (generally non-operative for Types

I-III; operative for some type III and all Types IV-VI). However, a diagnosis based on a single, static

sagittal radiograph may result in over-/under-estimation of the extent of the injury. For this reason,

attempts have been made to correlate radiographic classification with USS, MRI and intra-operative

findings.

Heers and Hedtmann (2005) found that USS was 80% sensitive and 100% specific for diagnosing

deltoid/ trapezial detachment and fascial disruption (intra-operatively confirmed). Interestingly, 9/31

Type III and 2/28 type II injuries were found to have damage to deltoid/ trapezius insertions or to the

delto-trapezial fascia. Nemec et al (2011) found that MRI findings were concordant with the

radiographic Rockwood type in 52% however, 36% were reclassified into a less severe type and 11%

into a more severe type. Additional ligamentous injuries were found in 25%.

Thus, whilst the Rockwood classification remains the main classification in use for ACJ injuries and is

easily used/ reproducible, investigative adjuncts such as USS and MRI may be useful in delineating

the extent of soft tissue damage, which is not apparent on static radiography. This may be

particularly important in Type III injuries in aiding the management decisions. Outcomes in both

conservative and operative treatment are mixed in this group and this could be due to poorer results

seen in those patients who have been conservatively managed that actually had more severe soft

tissue damage than appreciated radiographically.

8

5. Describe the biomechanics of ACJ stabilisers

The ACJ is a diarthrodial joint formed between the lateral end of the clavicle and the medial end of

the acromion. A fibrocartilaginous intra-articular disc may be found, though this degenerates by the

fourth decade. The clavicle rotates approximately 5° to 8° relative to the acromion because of

synchronous scapula-clavicular motion (Flatlow, 1993), which is probably why shoulder elevation

remains normal after CCJ arthrodesis. The ACJ stabilisers can be grouped into static and dynamic.

a) Static stabilisers

These include the following – ACJ capsule (thin, minimal contribution), AC ligaments, CC ligaments.

Fukuda et al (1986) studied the contribution of each structure to the overall stability of the ACJ. The

AC ligamentous complex is comprised of anterior, superior, posterior and inferior ligaments. The

posterior and superior AC ligaments are the strongest and provide the majority of stability in the AP

plane. Excision of more than 1 cm of distal clavicle results in increased posterior translation of the

clavicle (Branch, et al., 1996) (Corteen & Teitge, 2005).

The CC ligaments are comprised of the medial conoid ligament and the lateral trapezoid ligament.

The conoid ligament is the main vertical constraint, whilst the trapezoid resists compressive axial

loading of the ACJ (Fukuda, et al., 1986). Interestingly, the contributions to stability of these

structures differs with increasing loads (figure 1) – thus the AC ligaments are more important at small

loads whereas the conoid provided greater stability at larger loads.

9

Figure 1: Relative contributions of structures to ACJ vertical stability with increasing load (taken from pg 438 (Fukuda, et al., 1986))

b) Dynamic stabilisers

The anterior deltoid and trapezius muscles insert via the delto-trapezial fascia into the acromion/

superior AC ligament and provide dynamic stability to the ACJ and repair of these structures should

be considered as part of the reconstructive process (Lizaur, et al., 1994).

10

6. Describe treatment options for Type IV/V ACJ injuries. Give

biomechanical advantages/ disadvantages of these options

Generally, Type IV/ V injuries require surgical management to reduce and stabilise the ACJ. The goals

of treatment are to reduce the ACJ, pain free movement and to restore strength to (near) normal.

There are numerous procedures in use that can be broadly grouped into primary fixation, CC interval

fixation and anatomic CC reconstructions (ACCR). Some surgeons will combine procedures in an

attempt to augment repairs performed.

Primary fixation involves an open reduction of the joint, which is then stabilised by either K-wires,

Steinmann pins or a hook-plate (passed under the acromion). The ligamentous structures are allowed

to heal primarily whilst the joint is held reduced. The problems with these methods include loss of

reduction, hardware migration, ACJ OA and secondary metalwork removal (Lemos & Tolo, 2003).

CC interval fixation can also be performed to hold the clavicle reduced whilst the ligaments heal.

Older methods involved a CC screw (such as the Bosworth and Rockwood screws) whilst newer

methods employ the use of synthetic loops (suture material, tape) placed around the coracoid

process and clavicle. Disadvantages of these methods include breakage, fracture of coracoid/

clavicle, foreign body reaction, clavicle osteolysis and cut-out/ loss of reduction (Stewart & Ahmad,

2004). If screws are used, secondary hardware removal is also required. The use of tight-rope/ endo-

button devices has also been described (Walz, et al., 2008). This cadaveric study found the

reconstructed ACJ had greater loads to failure and less displacement than the native ACJ. Potential

complications include failure of the button device, fracture and loss of reduction.

Ligament reconstruction techniques seem to give the best biomechanical results in restoring/

maintaining ACJ reduction and providing a strong enough fixation to allow early mobilisation and

11

return to function. Furthermore, they provide a scaffold for revascularisation to occur. Disadvantages

include donor site morbidity.

The Weaver Dunn procedure describes transfer of the CA ligament to the distal clavicle (with

excision of the distal end of the clavicle). This technique has been extensively modified since its

description. Suture loops (CC) can be used to strengthen the construct. However, this still only

provides 25% of the strength of the intact CC complex with significant translations compared to

the normal ACJ (Harris, et al., 2000)

A similar procedure has been described using the lateral half of the conjoined tendon that is

harvested distally (left attached to coracoid) and then attached to the distal clavicle to hold it

reduced. This has been found to be stronger than using the CA ligament (which may be of

variable quality) (Jiang, et al., 2007)

ACCR using semitendinosus (or anterior tibialis) autograft can be used in a double bundled

fashion to anatomically recreate both components of the CC ligament. The graft is passed

through a coracoid bone tunnel, crossed into a figure-of-eight, secured with interference screws

in 2 separate clavicular bone tunnels, the anterior limb of the graft is sutured over the repaired

ACJ and the repair augmented with a suture loop. Mazzocca et al (2006) performed a cadaveric

comparison of this technique to a modified Weaver-Dunn repair (with suture loop augmentation)

and to an arthroscopic CC screw fixation (with suture loop augmentation). They reported that

only the anatomic double bundled repair provided AP and superior stability similar to the intact

ACJ.

12

7. With respect to ACJ injuries, review the literature and discuss

treatment options for all groups

a) Type I/ II

These injuries are treated conservatively: analgesia, rest in broad arm sling for 1-3 weeks, ROM/

strengthening exercises thereafter and return to activity when a pain-free ROM is achieved (usually

3-6 weeks). This may be extended to delay return to heavy manual work or contact sports until 8

weeks. Surgical intervention in these injuries is not supported although there are associated

mid/long-term complications. Minor symptoms (clicking, mild pain) may be found in 30% of Type I

and 42% of Type II injuries; severe symptoms (pain, limitation of activity) can be found in 9% of Type I

and 23% of Type II injuries (Bergfeld, et al., 1978). The same study reported the presence of

radiographic ACJ OA in 50%. Moushine et al (2003) reported that 27% of Type I/ II injuries treated

conservatively developed chronic ACJ symptoms (at mean of 6 months) requiring later surgery.

b) Type III

The majority of Type III injuries should probably be treated conservatively given the findings of

equivalent satisfaction (87%-conservative; 88%-operative), return to activity, pain relief, ROM and

strength in the meta-analysis of conservative vs. operative management by Phillips et al (1998).

Furthermore, surgically treated patients will have potential complications. Wojtys & Nelson (1991) et

al found a statistically insignificant reduction in strength and endurance in labourers and athletes

with conservative management. Although they concluded that adequate strength could be recovered

with conservative treatment, they felt that patients involved in activities requiring high-level

shoulder function might benefit from surgical intervention. This view is held by other authors

(Simovitch, et al., 2009), though the lack of conclusive evidence is noted. Furthermore, the risk of

late sequale (distal clavicle osteolysis, persistent pain/ instability and ACJ OA) should be discussed

13

with patients during the decision making process as surgery may be required later for these

complications.

An adequate structured rehabilitation programme (focus on strengthening deltoid, trapezius,

sternocleidomastoid, subclavius, rotator cuff and periscapular stabilizers (Simovitch, et al., 2009)) is

essential to proper conservative management of these injuries. Glick et al (1977) found no residual

pain in professional and competitive amateur athletes managed in this fashion.

The patients that do not do well with conservative treatment may represent a group with greater

soft tissue injury (than is appreciated by a single static radiograph) and therefore greater instability

that would do better with surgical intervention. This is an area that needs more clinically directed,

outcome-based research to define the role of acute imaging in guiding acute treatment of these

injuries.

c) Types IV/ V/ VI

These can be grouped together as they all require surgical intervention, along with some acute type

III injuries. There are numerous methods in use in the surgical management of these injuries (see

Question 6 for an overview of specific surgical methods and table 3). Ultimately, the aims of

treatment should be to reduce and stabilise the ACJ to allow pain-free ROM and return to (near)

normal strength. Jari et al (2004) suggest that methods that preserve the ACJ articulation are

preferable as they reduce the joint contact forces. What is apparent is that, biomechanically, ACCR

methods most closely recreate the normal CC ligament strength and stability. However, long-term

comparative/ controlled clinical results are lacking in the literature.

14

Study Methodology Outcome

(Mazzocca, et al., 2006) Modified Weaver-Dunn procedure vs.

arthroscopic suture fixation vs. ACCR

(semitendinosus)

Comparable vertical stability and load to failure

ACCR had least AP translation

(Jari, et al., 2004) CA ligament transfer vs. CC sling vs. Rockwood

screw

Largest vertical translations with after the CA ligament transfer (>300%)

Largest posterior translations with CC sling (330%)

Rockwood screw most rigid construct, but results in increased joint forces

(Costic, et al., 2004) Intact ACJ vs. ACCR (semitendinosus) Stiffness and ultimate load to failure of the ACCR was significantly lower than in the

normal ACJ with clinically insignificant elongation following cyclic loading

(Deshmukh, et al., 2004) Weaver-Dunn vs. augmented Weaver-Dunn

procedure

Greater load to failure in augmented Weaver-Dunn (319N vs. 177N) and less instability

No significant difference between suture anchor choice for the augmentation

(Lee, et al., 2003) CA ligament transfer vs. CC Mersilene tape sling

vs. ACCR (semitendinosus, gracilis, long toe

extensors)

CA ligament transfer weakest, Mersilene tape better initial strength

ACCR superior to both (similar ultimate load to failure among different grafts)

(Wilson, et al., 2005) Weaver-Dunn vs. Weaver-Dunn augmented

with CC suture anchor fixation

Augmented Weaver-Dunn better approximated normal ACJ stability

(Harris, et al., 2000) CA ligament transfer vs. CC sling vs. 2 CC suture

anchors vs. unicortical Bosworth screw vs.

bicortical Bosworth screw

CA ligament transfer weakest. CC slings had high tensile strength but elongated at failure.

Bicortical CC screws provided the highest tensile strength and stiffness

Table 3: Summary of ACJ reconstruction methods (adapted from pg 216-7 in (Simovitch, et al., 2009))

15

8. How would you have a Type III injury treated if it was your

shoulder? How would you manage an elite rugby player with the

same acute injury?

I would manage my shoulder and an elite rugby player with an acute Type III ACJ injury the same

way. Whilst I am not a professional level athlete, my chosen career path (orthopaedic surgery)

dictates that I maintain acceptable health and manual dexterity given the skilled (often fine/

precision work) nature of surgery. Anything less than near-normal restoration of ACJ function could

potentially affect my ability to operate as a surgeon now and in the future (in terms of late

complications such as on-going pain/ instability and ACJ OA).

I would have the injury fully assessed using USS (or MRI) to determine the extent of soft tissue

damage (including disruption of delto-trapezial fascia and deltoid/ trapezius muscle detachments)

that would require surgical repair. Given the current evidence (Simovitch, et al., 2009) (which

unfortunately is based on small case series and controlled laboratory studies), I would support the

use of an anatomic double-bundle autograft (semitendinosus) reconstruction of the CC ligaments

with repair + superior augmentation of the ACJ followed by an appropriate early mobilisation

physiotherapy programme (pendular/ passive ROM till 8 weeks to allow graft maturation, active

ROM thereafter). I would not allow resisted training to begin until after 3 months. In the case of an

elite rugby player, I would anticipate a return to full contact by 6 months.

16

9. References

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Surg, 49(4), pp. 774-84.

Andersen, K., Jensen, P. & Lauritzen, J., 1987. Treatment of clavicular fractures. Figure-of-eigth

bandage versus a simple sling. Acta Orthop Scand, Volume 58, pp. 71-4.

Bergfeld, J. A., Andrish, J. T. & Clancy, W. G., 1978. Evaluation of the acromioclavicular joint following

first- and second- degree sprains. Am J Sports Med, Volume 6, pp. 153-9.

Branch, T. P. et al., 1996. The role of acromioclavicular ligaments and the effect of distal clavicle

resection. Am J Sports Med, 24(3), pp. 293-7.

Cho, C.-H.et al., 2010. Operative treatment of clavicle midshaft fractures: Comparison between

reconstruction plate and reconstruction locking compression plate. Clin Orthop Surg, Volume 2, pp.

154-9.

Corteen, D. P. & Teitge, R. A., 2005. Stabilisation of the clavicle after distal resection: A biomechanical

study. Am J Sports Med, Volume 33, pp. 61-7.

Costic, R. S., Labriola, J. E., Rodosky, M. W. & Debski, R. E., 2004. Biomechanical rationale for

development of anatomical reconstructions of coracoclavicular ligaments after complete

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Craig, E., 1990. Fractures of the clavicle. In: C. A. Rockwood & F. A. Matsen, eds. The Shoulder.

Philadelphia: Saunders, pp. 380-3.

Deshmukh, A. V., Wilson, D. R., Zilberfarb, J. L. & Perlmutter, G. S., 2004. Stability of

acromioclavicular joint reconstruction: Biomechanical testing of various surgical techniques in a

cadaveric model. Am J Sports Med, Volume 32, pp. 1492-8.

Flatlow, E. L., 1993. The biomechanics of the acromioclavicular, sternoclavicular and scapulothoracic

joints. Instr Course Lect, Volume 42, pp. 237-45.

17

Fukuda, K. et al., 1986. Biomechanical study of the ligamentous system of the acromiclavicular joint. J

Bone Joint Surg Am, Volume 68, pp. 434-40.

Glick, J. M., Milburn, L. J., Haggerty, J. F. & Nishimoto, D., 1977. Dislocated acromioclavicular joint:

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Grassi, F., Tajana, M. & D'Angelo, F., 2001. Management of midclavicular fractures: comparison

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18

Liu, H. H. et al., 2010. Comparison of plates versus intramedullary nails for fixation of displaced

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