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Periprosthetic humeral fractures in shoulder arthroplasty
Author's Accepted Manuscript
Periprosthetic Humeral Fractures in Shoulder Arthroplasty James M. Gregory MD, Jason Hsu MD, Leesa M. Galatz MD
www.elsevier.com/locate/enganabound
PII: DOI: Reference:
S1045-4527(14)00045-5 http://dx.doi.org/10.1053/j.sart.2014.02.009 YSART50584
To appear in: Semin Arthro
Cite this article as: James M. Gregory MD, Jason Hsu MD, Leesa M. Galatz MD, Periprosthetic Humeral Fractures in Shoulder Arthroplasty, Semin Arthro , http://dx.doi.org/10.1053/j.sart.2014.02.009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Periprosthetic Humeral Fractures in Shoulder Arthroplasty James M. Gregory, MD; Jason Hsu, MD; Leesa M. Galatz, MD From the Shoulder and Elbow Service, Department of Orthopaedics, Washington University School of Medicine, Saint Louis, Missouri James Gregory Jason Hsu Leesa Galatz Reprint requests: Leesa Galatz – [email protected] Washington University Orthopaedics 660 S. Euclid Ave., Campus Box 8233 St. Louis, MO 63110
Abstract
Periprosthetic fractures associated with shoulder arthroplasty are uncommon, but can
be very difficult to treat. Treatment options depend on the timing of the fracture, the type of fracture, and the stability of the implant. Understanding these characteristics of periprosthetic fractures helps the practicing surgeon to avoid them, and also to determine how best to manage them when they do occur.
Despite the success of shoulder arthroplasty, periprosthetic fractures are a recognized
complication. Based on large case series, they have been estimated to occur in anatomic total shoulder arthroplasty with an incidence of between 1.5% and 2.4%.1‐3 Rates of fracture associated with reverse shoulder arthroplasty have not been as well described. Although multiple classification systems have been developed4,5, all are based on relatively small series, and are either of limited clinical relevance, or are insufficient to help guide treatment decisions. Instead, the three most essential characteristics that one needs to consider are the location of the fracture, the timing of the fracture, and the stability of the components. By understanding these characteristics, surgeons can be aware of the types of periprosthetic fractures associated with shoulder arthroplasty, how to avoid them, and how to manage them when they do occur.
Risk factors for periprosthetic fractures include age, rheumatoid arthritis, female sex,
osteopenia and excessive surgical manipulation2,6. Essentially, anything that decreases bone
quality is a risk factor for fracture. They can occur either intra‐operatively, or as a late complication. Intra‐operative fractures are primarily the result of poor surgical exposure or overzealous manipulation of the arm. A key to preventing these fractures is appropriate surgical positioning. Ensuring that the shoulder is off the edge of the bed allows extension and external rotation of the arm without undo force (Figure 1). Additionally, inadequate soft tissue releases or humeral head resection limit exposure and may cause errors in humeral preparation. Care must be taken to release the entire inferior capsule, the capsule on the undersurface of the subscapularis, and the rotator interval to allow appropriate retraction of these tissues. The entry point into the humeral canal may vary slightly, but typically is lateral to the center of rotation of the humeral head, posterior to the biceps groove (Figure 2). Failure to find an appropriate starting point or inadequate exposure may lead to reaming in a more varus position which risks lateral cortex perforation. Finally, when placing the humeral stem, care must be taken to avoid over‐sizing. Stems and trials in reverse shoulder arthroplasty, in particular, have a proximal flare that may cause a fracture if they are aggressively impacted without appropriate reaming. For post‐operative fractures, the same patient‐specific risks apply. In addition, creation of a stress‐riser substantially increases fracture risk. This may result from cortical perforation, endosteal notching, or even ipsilateral shoulder and elbow arthroplasties. Stem loosening or osteolysis creates cortical defects which may predispose to fracture as well.
Two major classification systems have been described for periprosthetic fractures. The
classification by Ianotti and Williams is primarily based on location (Table 1).4 Wright and
Cofield developed a classification system that is also based on location is relation to the tip of the humeral implant (Table 2).5 However, these systems have not been validated, and do not take into account the stability of prosthesis which is clearly important for decision making. The inter‐observer reliability of the Wright and Cofield classification was recently evaluated and found to be poor.7 Therefore, decision making cannot be based entirely on classification, and instead must rely on critical evaluation of the timing of the fracture, the location of the fracture, and the stability of the stem.
For those fractures that occur intra‐operatively, the key principle is ensuring that the
arm is stable at the completion of the case. Management should not be delayed until a later date. The location of the fracture is the primary guide to decision making. Fractures that occur around the tuberosities do not typically compromise stability of the stem. They can usually be fixed with heavy suture or wire (Figure 3). Even in the setting of reverse arthroplasty, in which the rotator cuff is not as critical, it is usually beneficial to reduce and fix tuberosity fractures. Fractures that involve the metaphysis must be bypassed with a long‐stem prosthesis that extends distal to the fracture at least two cortical diameters. A cerclage wire may also be helpful to reinforce the repair. Care must be taken to ensure that component version is correct, because the proximal segment may move independently from the elbow. Finally, fractures that occur at or distal to the tip of the stem should either be bypassed with a long‐ stem prosthesis or fixed by extramedullary plating (Figure 4).
A fracture may also present as a late complication. When these fractures occur in the
post‐operative setting, in addition to the location of the fracture, determination of stem
stability is key to surgical planning. Sperling et al and Sanchez‐Sotelo et al have previously identified radiographic signs of loosening that help pre‐operative identification of stem stability. 8,9
These signs are present in either cemented or uncemented stems, and are best noted on
sequential radiographs. They include ≥2mm of radiolucency present in three or more humeral zones, or evidence of subsidence or tilt. Use of these radiographic signs to identify loose humeral stems has been found to be very accurate.7 Once determination of stem stability has been made, the decision making simplifies. If the stem is loose, it needs to be revised. If the stem is stable, and the fracture is stable, then the fracture may be able to be treated non‐ operatively. Tuberosity fractures are managed in the same fashion as intra‐operative tuberosity fractures – securing the fragment with sutures or wires. Metaphyseal fractures require revision if the stem is loose, with supplementation by cerclage wires or plate fixation if needed. Diaphyseal fractures with a loose humeral stem are managed in a similar fashion. If a diaphyseal fractures occurs at or distal to the tip of a stable stem, then it may be managed non‐ operatively with a cast brace. Unstable diaphyseal fractures, or those the fail non‐operative treatment can be managed with hybrid plates and supplemental cortical strut allograft if needed for poor bone quality.10 (Figure 5) The average time to union for these surgically treated diaphyseal fractures has ranged from 5 to 7 months, and healing rates have approached 97‐100%.10,11
Again, for those fractures with a stable prosthesis and a stable fracture pattern, a trial of
non‐operative treatment with a cast brace is recommended (Figure 6). Long spiral or oblique fractures are particularly favorable for non‐operative treatment, as the strain at the fracture site is spread out over a much larger surface area. Risk factors for failure of non‐operative
treatment include smoking, poor bone quality, distraction at the fracture site, or inadequate immobilization. If the fractures do not heal by 3 months, then fixation may be considered pending discussion with the patient. Additionally, some patients develop skin breakdown from the cast brace. In our practice, this indicates an unstable fracture that is unable to be adequately stabilized by the cast brace, and would lead us towards operative intervention. Care must be taken in patients who present with stiff shoulders as well. In this case, the forces from arm motion will be transmitted directly through the fracture site instead of the glenohumeral joint, and may predispose to failure of treatment with functional bracing.
In summary, although the risk of periprosthetic fractures can be minimized with proper
attention to surgical technique, they do still occur. Timing of the fracture, location of the fracture, and stability of the stem are the major factors influencing management decisions. Intra‐operative fractures should be managed at the time of surgery according to their location. Tuberosity fractures can be fixed with wires, metaphyseal fractures can be bypassed with a stem, and diaphyseal fractures can either be bypassed, or fixed with a plate or cerclage wires. Management of post‐operative fractures depends on stem stability. Loose stems must be revised. Fractures in which the humeral stem is stable can either be managed non‐operatively in a stable fracture pattern, or fixed with hybrid plates in an unstable fracture pattern.
References 1. Athwal GS, Sperling JW, Rispoli DM, Cofield RH. Periprosthetic humeral fractures during shoulder arthroplasty. J Bone Joint Surg Am. 2009;91(3):594‐603.
2. Boyd AD,Jr, Thornhill TS, Barnes CL. Fractures adjacent to humeral prostheses. J Bone Joint Surg Am. 1992;74(10):1498‐1504.
3. Worland RL, Kim DY, Arredondo J. Periprosthetic humeral fractures: Management and classification. J Shoulder Elbow Surg. 1999;8(6):590‐594.
4. Williams GR,Jr, Iannotti JP. Management of periprosthetic fractures: The shoulder. J Arthroplasty. 2002;17(4 Suppl 1):14‐16.
5. Wright TW, Cofield RH. Humeral fractures after shoulder arthroplasty. J Bone Joint Surg Am. 1995;77(9):1340‐1346.
6. Campbell JT, Moore RS, Iannotti JP, Norris TR, Williams GR. Periprosthetic humeral fractures: Mechanisms of fracture and treatment options. J Shoulder Elbow Surg. 1998;7(4):406‐413.
7. Cheung E, Willis M, Walker M, Clark R, Frankle MA. Complications in reverse total shoulder arthroplasty. J Am Acad Orthop Surg. 2011;19(7):439‐449.
8. Sperling JW, Cofield RH, O'Driscoll SW, Torchia ME, Rowland CM. Radiographic assessment of ingrowth total shoulder arthroplasty. J Shoulder Elbow Surg. 2000;9(6):507‐513.
9. Sanchez‐Sotelo J, O'Driscoll SW, Torchia ME, Cofield RH, Rowland CM. Radiographic assessment of cemented humeral components in shoulder arthroplasty. J Shoulder Elbow Surg. 2001;10(6):526‐531.
10. Andersen JR, Williams CD, Cain R, Mighell M, Frankle M. Surgically treated humeral shaft fractures following shoulder arthroplasty. J Bone Joint Surg Am. 2013;95(1):9‐18.
11. Mineo GV, Accetta R, Franceschini M, Pedrotti Dell'Acqua G, Calori GM, Meersseman A. Management of shoulder periprosthetic fractures: Our institutional experience and review of the literature. Injury. 2013;44 Suppl 1:S82‐5.
Figures
Figure 1. Appropriate patient positioning includes ensuring that shoulder is positioned off of the bed so that the arm is free to extend and externally rotate. In this case, the shoulder pad on the operating table is removable (black arrow).
Figure 2. When reaming, care is taken to identify a start point on the lateral aspect of the humeral head to ensure that the reamer is not introduced in a varus position.
Figure 3. Anteroposterior radiograph of the right shoulder demonstrates an intra‐operative tuberosity fracture that was secured with cerclage wires.
Figure 4. Post‐operative radiograph of the right humerus demonstrates an intra‐operative diaphyseal fracture that was treated with lag screws and a lateral plate.
Figure 5. (A) Radiograph of the left humerus shows a traumatic diaphyseal fracture distal to a well‐fixed humeral component. (B) Given the poor quality of the bone at the fracture site, the fracture was treated with open reduction and internal fixation
Figure 6. Two views of the right shoulder demonstrate a traumatic diaphyseal fracture distal to a well‐fixed reverse shoulder arthroplasty. It is being treated with a cast brace. The oblique fracture line and stable component makes non‐operative treatment favorable. On an unrelated note, disengagement of the glenosphere is observed.
Table 1. Iannotti and Williams classification of periprosthetic fractures Region Location of Fracture 1 2 3 4
Tuberosity Metaphyseal fracture Proximal diaphysis Diaphysis distal to tip of stem
Table 2. Wright and Cofield classification of periprosthetic fractures Type A B C
Location of Fracture
Begins at tip of humeral stem and extends proximally Begins at tip of humeral stem and extends distally Completely distal to tip of humeral stem
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5A
Fig. 5B
Fig. 6A
Fig. 6B
Periprosthetic Humeral Fractures in Shoulder Arthroplasty James M. Gregory MD, Jason Hsu MD, Leesa M. Galatz MD
www.elsevier.com/locate/enganabound
PII: DOI: Reference:
S1045-4527(14)00045-5 http://dx.doi.org/10.1053/j.sart.2014.02.009 YSART50584
To appear in: Semin Arthro
Cite this article as: James M. Gregory MD, Jason Hsu MD, Leesa M. Galatz MD, Periprosthetic Humeral Fractures in Shoulder Arthroplasty, Semin Arthro , http://dx.doi.org/10.1053/j.sart.2014.02.009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Periprosthetic Humeral Fractures in Shoulder Arthroplasty James M. Gregory, MD; Jason Hsu, MD; Leesa M. Galatz, MD From the Shoulder and Elbow Service, Department of Orthopaedics, Washington University School of Medicine, Saint Louis, Missouri James Gregory Jason Hsu Leesa Galatz Reprint requests: Leesa Galatz – [email protected] Washington University Orthopaedics 660 S. Euclid Ave., Campus Box 8233 St. Louis, MO 63110
Abstract
Periprosthetic fractures associated with shoulder arthroplasty are uncommon, but can
be very difficult to treat. Treatment options depend on the timing of the fracture, the type of fracture, and the stability of the implant. Understanding these characteristics of periprosthetic fractures helps the practicing surgeon to avoid them, and also to determine how best to manage them when they do occur.
Despite the success of shoulder arthroplasty, periprosthetic fractures are a recognized
complication. Based on large case series, they have been estimated to occur in anatomic total shoulder arthroplasty with an incidence of between 1.5% and 2.4%.1‐3 Rates of fracture associated with reverse shoulder arthroplasty have not been as well described. Although multiple classification systems have been developed4,5, all are based on relatively small series, and are either of limited clinical relevance, or are insufficient to help guide treatment decisions. Instead, the three most essential characteristics that one needs to consider are the location of the fracture, the timing of the fracture, and the stability of the components. By understanding these characteristics, surgeons can be aware of the types of periprosthetic fractures associated with shoulder arthroplasty, how to avoid them, and how to manage them when they do occur.
Risk factors for periprosthetic fractures include age, rheumatoid arthritis, female sex,
osteopenia and excessive surgical manipulation2,6. Essentially, anything that decreases bone
quality is a risk factor for fracture. They can occur either intra‐operatively, or as a late complication. Intra‐operative fractures are primarily the result of poor surgical exposure or overzealous manipulation of the arm. A key to preventing these fractures is appropriate surgical positioning. Ensuring that the shoulder is off the edge of the bed allows extension and external rotation of the arm without undo force (Figure 1). Additionally, inadequate soft tissue releases or humeral head resection limit exposure and may cause errors in humeral preparation. Care must be taken to release the entire inferior capsule, the capsule on the undersurface of the subscapularis, and the rotator interval to allow appropriate retraction of these tissues. The entry point into the humeral canal may vary slightly, but typically is lateral to the center of rotation of the humeral head, posterior to the biceps groove (Figure 2). Failure to find an appropriate starting point or inadequate exposure may lead to reaming in a more varus position which risks lateral cortex perforation. Finally, when placing the humeral stem, care must be taken to avoid over‐sizing. Stems and trials in reverse shoulder arthroplasty, in particular, have a proximal flare that may cause a fracture if they are aggressively impacted without appropriate reaming. For post‐operative fractures, the same patient‐specific risks apply. In addition, creation of a stress‐riser substantially increases fracture risk. This may result from cortical perforation, endosteal notching, or even ipsilateral shoulder and elbow arthroplasties. Stem loosening or osteolysis creates cortical defects which may predispose to fracture as well.
Two major classification systems have been described for periprosthetic fractures. The
classification by Ianotti and Williams is primarily based on location (Table 1).4 Wright and
Cofield developed a classification system that is also based on location is relation to the tip of the humeral implant (Table 2).5 However, these systems have not been validated, and do not take into account the stability of prosthesis which is clearly important for decision making. The inter‐observer reliability of the Wright and Cofield classification was recently evaluated and found to be poor.7 Therefore, decision making cannot be based entirely on classification, and instead must rely on critical evaluation of the timing of the fracture, the location of the fracture, and the stability of the stem.
For those fractures that occur intra‐operatively, the key principle is ensuring that the
arm is stable at the completion of the case. Management should not be delayed until a later date. The location of the fracture is the primary guide to decision making. Fractures that occur around the tuberosities do not typically compromise stability of the stem. They can usually be fixed with heavy suture or wire (Figure 3). Even in the setting of reverse arthroplasty, in which the rotator cuff is not as critical, it is usually beneficial to reduce and fix tuberosity fractures. Fractures that involve the metaphysis must be bypassed with a long‐stem prosthesis that extends distal to the fracture at least two cortical diameters. A cerclage wire may also be helpful to reinforce the repair. Care must be taken to ensure that component version is correct, because the proximal segment may move independently from the elbow. Finally, fractures that occur at or distal to the tip of the stem should either be bypassed with a long‐ stem prosthesis or fixed by extramedullary plating (Figure 4).
A fracture may also present as a late complication. When these fractures occur in the
post‐operative setting, in addition to the location of the fracture, determination of stem
stability is key to surgical planning. Sperling et al and Sanchez‐Sotelo et al have previously identified radiographic signs of loosening that help pre‐operative identification of stem stability. 8,9
These signs are present in either cemented or uncemented stems, and are best noted on
sequential radiographs. They include ≥2mm of radiolucency present in three or more humeral zones, or evidence of subsidence or tilt. Use of these radiographic signs to identify loose humeral stems has been found to be very accurate.7 Once determination of stem stability has been made, the decision making simplifies. If the stem is loose, it needs to be revised. If the stem is stable, and the fracture is stable, then the fracture may be able to be treated non‐ operatively. Tuberosity fractures are managed in the same fashion as intra‐operative tuberosity fractures – securing the fragment with sutures or wires. Metaphyseal fractures require revision if the stem is loose, with supplementation by cerclage wires or plate fixation if needed. Diaphyseal fractures with a loose humeral stem are managed in a similar fashion. If a diaphyseal fractures occurs at or distal to the tip of a stable stem, then it may be managed non‐ operatively with a cast brace. Unstable diaphyseal fractures, or those the fail non‐operative treatment can be managed with hybrid plates and supplemental cortical strut allograft if needed for poor bone quality.10 (Figure 5) The average time to union for these surgically treated diaphyseal fractures has ranged from 5 to 7 months, and healing rates have approached 97‐100%.10,11
Again, for those fractures with a stable prosthesis and a stable fracture pattern, a trial of
non‐operative treatment with a cast brace is recommended (Figure 6). Long spiral or oblique fractures are particularly favorable for non‐operative treatment, as the strain at the fracture site is spread out over a much larger surface area. Risk factors for failure of non‐operative
treatment include smoking, poor bone quality, distraction at the fracture site, or inadequate immobilization. If the fractures do not heal by 3 months, then fixation may be considered pending discussion with the patient. Additionally, some patients develop skin breakdown from the cast brace. In our practice, this indicates an unstable fracture that is unable to be adequately stabilized by the cast brace, and would lead us towards operative intervention. Care must be taken in patients who present with stiff shoulders as well. In this case, the forces from arm motion will be transmitted directly through the fracture site instead of the glenohumeral joint, and may predispose to failure of treatment with functional bracing.
In summary, although the risk of periprosthetic fractures can be minimized with proper
attention to surgical technique, they do still occur. Timing of the fracture, location of the fracture, and stability of the stem are the major factors influencing management decisions. Intra‐operative fractures should be managed at the time of surgery according to their location. Tuberosity fractures can be fixed with wires, metaphyseal fractures can be bypassed with a stem, and diaphyseal fractures can either be bypassed, or fixed with a plate or cerclage wires. Management of post‐operative fractures depends on stem stability. Loose stems must be revised. Fractures in which the humeral stem is stable can either be managed non‐operatively in a stable fracture pattern, or fixed with hybrid plates in an unstable fracture pattern.
References 1. Athwal GS, Sperling JW, Rispoli DM, Cofield RH. Periprosthetic humeral fractures during shoulder arthroplasty. J Bone Joint Surg Am. 2009;91(3):594‐603.
2. Boyd AD,Jr, Thornhill TS, Barnes CL. Fractures adjacent to humeral prostheses. J Bone Joint Surg Am. 1992;74(10):1498‐1504.
3. Worland RL, Kim DY, Arredondo J. Periprosthetic humeral fractures: Management and classification. J Shoulder Elbow Surg. 1999;8(6):590‐594.
4. Williams GR,Jr, Iannotti JP. Management of periprosthetic fractures: The shoulder. J Arthroplasty. 2002;17(4 Suppl 1):14‐16.
5. Wright TW, Cofield RH. Humeral fractures after shoulder arthroplasty. J Bone Joint Surg Am. 1995;77(9):1340‐1346.
6. Campbell JT, Moore RS, Iannotti JP, Norris TR, Williams GR. Periprosthetic humeral fractures: Mechanisms of fracture and treatment options. J Shoulder Elbow Surg. 1998;7(4):406‐413.
7. Cheung E, Willis M, Walker M, Clark R, Frankle MA. Complications in reverse total shoulder arthroplasty. J Am Acad Orthop Surg. 2011;19(7):439‐449.
8. Sperling JW, Cofield RH, O'Driscoll SW, Torchia ME, Rowland CM. Radiographic assessment of ingrowth total shoulder arthroplasty. J Shoulder Elbow Surg. 2000;9(6):507‐513.
9. Sanchez‐Sotelo J, O'Driscoll SW, Torchia ME, Cofield RH, Rowland CM. Radiographic assessment of cemented humeral components in shoulder arthroplasty. J Shoulder Elbow Surg. 2001;10(6):526‐531.
10. Andersen JR, Williams CD, Cain R, Mighell M, Frankle M. Surgically treated humeral shaft fractures following shoulder arthroplasty. J Bone Joint Surg Am. 2013;95(1):9‐18.
11. Mineo GV, Accetta R, Franceschini M, Pedrotti Dell'Acqua G, Calori GM, Meersseman A. Management of shoulder periprosthetic fractures: Our institutional experience and review of the literature. Injury. 2013;44 Suppl 1:S82‐5.
Figures
Figure 1. Appropriate patient positioning includes ensuring that shoulder is positioned off of the bed so that the arm is free to extend and externally rotate. In this case, the shoulder pad on the operating table is removable (black arrow).
Figure 2. When reaming, care is taken to identify a start point on the lateral aspect of the humeral head to ensure that the reamer is not introduced in a varus position.
Figure 3. Anteroposterior radiograph of the right shoulder demonstrates an intra‐operative tuberosity fracture that was secured with cerclage wires.
Figure 4. Post‐operative radiograph of the right humerus demonstrates an intra‐operative diaphyseal fracture that was treated with lag screws and a lateral plate.
Figure 5. (A) Radiograph of the left humerus shows a traumatic diaphyseal fracture distal to a well‐fixed humeral component. (B) Given the poor quality of the bone at the fracture site, the fracture was treated with open reduction and internal fixation
Figure 6. Two views of the right shoulder demonstrate a traumatic diaphyseal fracture distal to a well‐fixed reverse shoulder arthroplasty. It is being treated with a cast brace. The oblique fracture line and stable component makes non‐operative treatment favorable. On an unrelated note, disengagement of the glenosphere is observed.
Table 1. Iannotti and Williams classification of periprosthetic fractures Region Location of Fracture 1 2 3 4
Tuberosity Metaphyseal fracture Proximal diaphysis Diaphysis distal to tip of stem
Table 2. Wright and Cofield classification of periprosthetic fractures Type A B C
Location of Fracture
Begins at tip of humeral stem and extends proximally Begins at tip of humeral stem and extends distally Completely distal to tip of humeral stem
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5A
Fig. 5B
Fig. 6A
Fig. 6B