User login
Acute Shortening Versus Bridging Plate for Highly Comminuted Olecranon Fractures
Take-Home Points
- The ulnohumeral joint can tolerate substantial articular surface loss without compromising stability.
- Consider BP as an alternative to AS in unreconstructable olecranon fractures.
- Both BP and AS of olecranon fractures maintain elbow stability.
- BP has the advantage of maintaining elbow range of motion.
Olecranon fractures constitute about 10% of all forearm fractures.1 Many are low-energy fractures in osteoporotic bone in the elderly.1,2 Unstable fractures require operative fixation in which the goal is restoration of articular congruity and stability.3 Various fixation methods are used to treat unstable olecranon fractures, and outcomes are good overall.3-21 However, severely comminuted olecranon fractures, especially in osteoporotic bone, pose a unique challenge, where reconstruction may not be feasible.9 Although the articular surface can be reconstructed in most cases, reconstruction is not feasible with severe comminution or low bone mineral density. When articular congruity is no longer possible, the primary goal of fixation becomes elbow stability. Postoperative stability is linked to favorable outcomes, as it allows patients to engage in early range-of-motion (ROM) exercises, which improves joint function.5,21,22
When treating these severely comminuted olecranon fractures, surgeons have 2 options: bridge plating (BP) and acute shortening (AS). In BP, a plate is used to restore the length of the olecranon. The plate is spanned over the comminuted segment with fixation at proximal and distal pieces but without open reduction of the comminuted pieces.8 This process may be performed with or without bone grafting.21 Although any bony defect between the proximal and distal pieces may be filled, there is now a gap in articular congruity within the sigmoid notch. One concern with this fixation method is that joint stability is lost when this gap becomes too large. Surgeons therefore may decide to forgo BP and perform AS instead, as long as the coronoid is intact.21 In AS, often referred to as olecranon excision, comminuted fragments are removed and the triceps muscle advanced distally. AS constructs, often reserved for older, less active patients, yield acceptable results in this population.5 However, the long-term effects of AS in young, active patients are unclear, and biomechanical studies suggest reduced triceps muscle strength.23
Surgeons have had no studies guiding them in deciding which construct to use, BP or AS, in severely comminuted olecranon fractures in which the articular surface cannot be reconstructed.
We conducted a biomechanical study to determine the percentage loss of articular surface at which a BP construct becomes significantly clinically unstable. We also compared BP stability and AS stability for each percentage loss of articular surface and compared initial elbow ROM with the 2 methods. We hypothesized that, at a certain percentage loss of articular congruity, the BP construct would become too unstable and would require conversion to the AS construct.
Materials and Methods
Specimen Preparation
Eight fresh-frozen paired cadaveric upper limbs (2 male, 2 female; mean age, 61.8 years; age range, 56-74 years) were obtained from donors with no history of elbow trauma or prior surgery. Specimens were stored at –20°C, thawed to room temperature before testing, and, using clinical and radiographic evaluation, screened for abnormalities.
Each specimen was positioned with the arm draped in the lateral decubitus position, as in typical olecranon fracture surgery. A standard posterior approach to the olecranon was made with a midline posterior longitudinal skin incision. Subcutaneous flaps were developed, and the subcutaneous border of the proximal olecranon was exposed, preserving the medial and lateral collateral ligaments as well as the extensor mechanism. Baseline maximum flexion and extension of the elbow as well as olecranon length were measured with fluoroscopy (BV Pulsera, Philips) and ImageJ software (National Institutes of Health).
To ensure reproducible anatomical reduction during plating, a 3.5-mm 4-hole nonlocking periarticular anatomically contoured plate (Zimmer Biomet) was applied posteriorly to the intact olecranon through a longitudinal slit in the distal triceps tendon. The plate was predrilled to house 4 nonlocking screws, 2 proximal and 2 distal.
Fracture Generation and Testing of Fixation Constructs
Analysis
ImageJ software was used to analyze the C-arm radiographs. Measurements were divided into 4 groups of joint surface loss caused by the resections: 0% to 20%, 20% to 40%, 40% to 60%, and >60%. Differences in ROM between the BP and AS constructs were analyzed with a Wilcoxon signed rank test with statistical significance set at P < .05 (Prism 6; GraphPad Software).
Results
As many as 6 serial resections were made before the proximal fragment of the olecranon was judged too small to be secured to a plate with at least 2 screws. Only 7 specimens were large enough for the fifth cut, and only 4 were large enough for the sixth cut. After the final resection, mean loss of olecranon length was 77.3% (range, 63.7%-88%; median, 80.6%). All elbow specimens remained stable to manual valgus and varus testing in full extension, 30° of flexion, and full flexion in both supination and pronation. There was no medial or lateral opening of the ulnohumeral joint on fluoroscopy throughout testing, for either the BP or the AS constructs. There was no anterior or posterior subluxation throughout the entire ROM.
Discussion
Our goal in this study was to determine the maximum articular surface loss that can be tolerated before a BP construct becomes unstable. This finding applies to situations in which the degree of comminution makes reconstruction of the articular surface impossible. Contrary to our hypothesis, the ulnohumeral joint remained stable despite extensive loss of congruity within the sigmoid notch. In 1 specimen, the joint remained stable at 88% loss of olecranon. However, the 2 constructs had different ROM results: ROM was significantly lower at more resections with AS but remained unchanged from baseline with BP.
Dorsal plating has become standard treatment for comminuted olecranon fractures, and many studies, both clinical and biomechanical, have reported favorable results, good functional outcomes, and acceptable ROM.3,7,10,13,18-20,25 However, the multiple studies on the use of various plates in comminuted olecranon fractures did not address whether articular congruity was maintained during reductions or how much articular surface was reconstructed. Although we may reasonably assume larger studies included cases with some unmeasured loss of articular congruity, it is difficult to directly compare our findings with those of other studies. In addition, it is possible those studies did not include fractures that were deemed unfit for BP (because of very severe comminution) and underwent AS instead. Only 1 case series has focused on BP without complete articular reconstruction.8 The cases in that series had good outcomes with good stability—consistent with our finding of extreme comminution in a worst-case scenario.
Complete elbow stability after AS is consistent with findings in the literature.4,6,12,14,16 As AS is reserved for severely comminuted fractures and bone resections,21,23,26 our findings can be compared with the earlier findings. In AS, either the proximal pieces or the intermediate pieces are removed to create a smaller but congruent articular surface, with less concern for nonunion.21 When the proximal piece is removed, the triceps muscle is advanced to the ulnar shaft, creating a slinglike structure for the trochlea.4,11,16,23 When the intermediate piece is removed, the proximal piece is advanced to the shaft along with the triceps.12,14,27 In either technique, the triceps muscle is advanced distally, potentially affecting its extensibility and moment arm.23
Although small in numbers, case series and retrospective reviews have found that AS has good outcomes,4,14,16 whereas our study found significantly decreased ROM. A few patients in these studies lost ROM or triceps strength,12,14,16 but the cause, AS or fracture severity, is unclear. It is possible only 0% to 20% of the olecranon was resected in those cases, whereas our study found no significant change in ROM. It is also possible that cadaveric muscles do not stretch as well as muscles in vivo. Biomechanical studies have demonstrated changes in triceps stretch and strength,23,26 but perhaps these changes are subclinical or overcome with therapy and time.12,14 There are no data regarding whether patients who undergo AS (vs another fixation method) need more physical therapy. In extreme resection, some reduction in ROM is expected.13
The ulnohumeral joint is a primary static stabilizer of the elbow joint.28-30 Recent studies on the role of the ulnohumeral joint in elbow stability have focused mainly on the coronoid process in the setting of dislocation.28,29,31,32 According to these studies, 50% of the coronoid must remain intact for the elbow to be stable when all other stabilizers are intact.32 In our study, resections preserved the coronoid and the ligamentous stabilizers of the elbow. It is therefore possible that the elbow joint remained stable despite the considerable articular surface loss. Although the term ulnohumeral joint refers to both the coronoid and the remaining articular surface, our findings support the coronoid as a primary stabilizer and the remaining articular surface as a secondary static stabilizer.
This study had several limitations. First, its fractures were simulated by serial resection of only the middle portion of the olecranon. In reality, comminution could extend farther proximally or distally and involve the surrounding tissues, which help stabilize the elbow. However, our focus was on loss of articular surface and stability, so keeping surrounding structures intact avoided confounding factors that could contribute to stability. A second possible limitation is that the implant used here may be different from the implant used in a clinical setting. However, our focus was not on fixation quality, and stability alone should not be affected by plate type. Third, stability was measured not quantitatively but instead subjectively under manual stress and fluoroscopy. We chose this method because it mimics what happens during surgery and is the clinical standard for stability assessment.24 Fourth, soft-tissue properties of the cadaver models used in this biomechanical study may differ from soft-tissue properties in vivo. This study could not evaluate possible long-term complications, such as posttraumatic arthritis and heterotopic ossification.5,10 There are no long-term studies comparing BP and other olecranon fixation methods in terms of postoperative elbow arthritis.
Conclusion
The ulnohumeral joint can tolerate substantial articular surface loss without compromising stability. As a result, in the management of highly comminuted olecranon fractures, BP may be considered before AS is performed. Quality and amount of intact proximal bone, rather than degree of comminution, may be more important factors in deciding which fixation method to use.
This biomechanical study is the first to focus on olecranon fracture BP without complete reconstruction of the articular surface. When treating a highly comminuted olecranon fracture that has an unreconstructible articular surface, surgeons may consider BP with or without bone graft, as well as AS. Our study findings suggest that, though both constructs maintain elbow stability, BP may have the advantage of maintaining ROM too. BP can avoid effects on triceps and elbow ROM, which may be more important in younger, more active patients. Clinical correlates are needed to validate these findings, as overall outcomes may be affected by concurrent fractures and injuries to surrounding structures.
1. Court-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury. 2006;37(8):691-697.
2. Duckworth AD, Clement ND, Aitken SA, Court-Brown CM, McQueen MM. The epidemiology of fractures of the proximal ulna. Injury. 2012;43(3):343-346.
3. Bailey CS, MacDermid J, Patterson SD, King GJ. Outcome of plate fixation of olecranon fractures. J Orthop Trauma. 2001;15(8):542-548.
4. Adler S, Fay GF, Macausland WR Jr. Treatment of olecranon fractures. Indications for excision of the olecranon fragment and repair of the triceps tendon. J Trauma. 1962;2:597-602.
5. Baecher N, Edwards S. Olecranon fractures. J Hand Surg Am. 2013;38(3):593-604.
6. Bell TH, Ferreira LM, McDonald CP, Johnson JA, King GJW. Contribution of the olecranon to elbow stability: an in vitro biomechanical study. J Bone Joint Surg Am. 2010;92(4):949-957.
7. Buijze G, Kloen P. Clinical evaluation of locking compression plate fixation for comminuted olecranon fractures. J Bone Joint Surg Am. 2009;91(10):2416-2420.
8. Cervera-Irimia J, Tomé-Bermejo F, Gómez-Bermejo MA, Holgado-Moreno E, Stratenwerth EG. Treatment of comminuted olecranon fractures with olecranon plate and structural iliac crest graft. Acta Orthop Belg. 2012;78(6):703-707.
9. Edwards SG, Martin BD, Fu RH, et al. Comparison of olecranon plate fixation in osteoporotic bone: do current technologies and designs make a difference? J Orthop Trauma. 2011;25(5):306-311.
10. Erturer RE, Sever C, Sonmez MM, Ozcelik IB, Akman S, Ozturk I. Results of open reduction and plate osteosynthesis in comminuted fracture of the olecranon. J Shoulder Elbow Surg. 2011;20(3):449-454.
11. Estourgie RJ, Tinnemans JG. Treatment of grossly comminuted fractures of the olecranon by excision. Neth J Surg. 1982;34(3):127-129.
12. Fern ED, Brown JN. Olecranon advancement osteotomy in the management of severely comminuted olecranon fractures. Injury. 1993;24(4):267-269.
13. Gordon MJ, Budoff JE, Yeh ML, Luo ZP, Noble PC. Comminuted olecranon fractures: a comparison of plating methods. J Shoulder Elbow Surg. 2006;15(1):94-99.
14. Iannuzzi N, Dahners L. Excision and advancement in the treatment of comminuted olecranon fractures. J Orthop Trauma. 2009;23(3):226-228.
15. Ikeda M, Fukushima Y, Kobayashi Y, Oka Y. Comminuted fractures of the olecranon. Management by bone graft from the iliac crest and multiple tension-band wiring. J Bone Joint Surg Br. 2001;83(6):805-808.
16. McKeever FM, Buck RM. Fracture of the olecranon process of the ulna; treatment by excision of fragment and repair of triceps tendon. JAMA. 1947;135(1):1-5.
17. Rommens PM, Küchle R, Schneider RU, Reuter M. Olecranon fractures in adults: factors influencing outcome. Injury. 2004;35(11):1149-1157.
18. Siebenlist S, Torsiglieri T, Kraus T, Burghardt RD, Stöckle U, Lucke M. Comminuted fractures of the proximal ulna—preliminary results with an anatomically preshaped locking compression plate (LCP) system. Injury. 2010;41(12):1306-1311.
19. Tarallo L, Mugnai R, Adani R, Capra F, Zambianchi F, Catani F. Simple and comminuted displaced olecranon fractures: a clinical comparison between tension band wiring and plate fixation techniques. Arch Orthop Trauma Surg. 2014;134(8):1107-1114.
20. Wang Y, Tao R, Xu H, Cao Y, Zhou Z, Xu S. Mid-term outcomes of contoured plating for comminuted fractures of the olecranon. Orthop Surg. 2011;3(3):176-180.
21. Newman SD, Mauffrey C, Krikler S. Olecranon fractures. Injury. 2009;40(6):575-581.
22. Boyer MI, Galatz LM, Borrelli J, Axelrod TS, Ricci WM. Intra-articular fractures of the upper extremity: new concepts in surgical treatment. Instr Course Lect. 2003;52:591-605.
23. Didonna ML, Fernandez JJ, Lim TH, Hastings H, Cohen MS. Partial olecranon excision: the relationship between triceps insertion site and extension strength of the elbow. J Hand Surg Am. 2003;28(1):117-122.
24. Trumble T, Cornwall R, Budoff J. Core Knowledge in Orthopaedics: Hand, Elbow, and Shoulder. Philadelphia, PA: Mosby; 2006.
25. Simpson NS, Goodman LA, Jupiter JB. Contoured LCDC plating of the proximal ulna. Injury. 1996;27(6):411-417.
26. Ferreira LM, Bell TH, Johnson JA, King GJ. The effect of triceps repair techniques following olecranon excision on elbow stability and extension strength: an in vitro biomechanical study. J Orthop Trauma. 2011;25(7):420-424.
27. Colton CL. Fractures of the olecranon in adults: classification and management. Injury. 1973;5(2):121-129.
28. Hull JR, Owen JR, Fern SE, Wayne JS, Boardman ND 3rd. Role of the coronoid process in varus osteoarticular stability of the elbow. J Shoulder Elbow Surg. 2005;14(4):441-446.
29. Morrey BF, An KN. Stability of the elbow: osseous constraints. J Shoulder Elbow Surg. 2005;14(1 suppl S):174S-178S.
30. Williams G, Ramsey M, Wiesel S. Operative Techniques in Shoulder and Elbow Surgery. Philadelphia, PA: Lippincott Williams & Wilkins; 2011.
31. Schneeberger AG, Sadowski MM, Jacob HA. Coronoid process and radial head as posterolateral rotatory stabilizers of the elbow. J Bone Joint Surg Am. 2004;86(5):975-982.
32. Closkey RF, Goode JR, Kirschenbaum D, Cody RP. The role of the coronoid process in elbow stability. A biomechanical analysis of axial loading. J Bone Joint Surg Am. 2000;82(12):1749-1753.
Take-Home Points
- The ulnohumeral joint can tolerate substantial articular surface loss without compromising stability.
- Consider BP as an alternative to AS in unreconstructable olecranon fractures.
- Both BP and AS of olecranon fractures maintain elbow stability.
- BP has the advantage of maintaining elbow range of motion.
Olecranon fractures constitute about 10% of all forearm fractures.1 Many are low-energy fractures in osteoporotic bone in the elderly.1,2 Unstable fractures require operative fixation in which the goal is restoration of articular congruity and stability.3 Various fixation methods are used to treat unstable olecranon fractures, and outcomes are good overall.3-21 However, severely comminuted olecranon fractures, especially in osteoporotic bone, pose a unique challenge, where reconstruction may not be feasible.9 Although the articular surface can be reconstructed in most cases, reconstruction is not feasible with severe comminution or low bone mineral density. When articular congruity is no longer possible, the primary goal of fixation becomes elbow stability. Postoperative stability is linked to favorable outcomes, as it allows patients to engage in early range-of-motion (ROM) exercises, which improves joint function.5,21,22
When treating these severely comminuted olecranon fractures, surgeons have 2 options: bridge plating (BP) and acute shortening (AS). In BP, a plate is used to restore the length of the olecranon. The plate is spanned over the comminuted segment with fixation at proximal and distal pieces but without open reduction of the comminuted pieces.8 This process may be performed with or without bone grafting.21 Although any bony defect between the proximal and distal pieces may be filled, there is now a gap in articular congruity within the sigmoid notch. One concern with this fixation method is that joint stability is lost when this gap becomes too large. Surgeons therefore may decide to forgo BP and perform AS instead, as long as the coronoid is intact.21 In AS, often referred to as olecranon excision, comminuted fragments are removed and the triceps muscle advanced distally. AS constructs, often reserved for older, less active patients, yield acceptable results in this population.5 However, the long-term effects of AS in young, active patients are unclear, and biomechanical studies suggest reduced triceps muscle strength.23
Surgeons have had no studies guiding them in deciding which construct to use, BP or AS, in severely comminuted olecranon fractures in which the articular surface cannot be reconstructed.
We conducted a biomechanical study to determine the percentage loss of articular surface at which a BP construct becomes significantly clinically unstable. We also compared BP stability and AS stability for each percentage loss of articular surface and compared initial elbow ROM with the 2 methods. We hypothesized that, at a certain percentage loss of articular congruity, the BP construct would become too unstable and would require conversion to the AS construct.
Materials and Methods
Specimen Preparation
Eight fresh-frozen paired cadaveric upper limbs (2 male, 2 female; mean age, 61.8 years; age range, 56-74 years) were obtained from donors with no history of elbow trauma or prior surgery. Specimens were stored at –20°C, thawed to room temperature before testing, and, using clinical and radiographic evaluation, screened for abnormalities.
Each specimen was positioned with the arm draped in the lateral decubitus position, as in typical olecranon fracture surgery. A standard posterior approach to the olecranon was made with a midline posterior longitudinal skin incision. Subcutaneous flaps were developed, and the subcutaneous border of the proximal olecranon was exposed, preserving the medial and lateral collateral ligaments as well as the extensor mechanism. Baseline maximum flexion and extension of the elbow as well as olecranon length were measured with fluoroscopy (BV Pulsera, Philips) and ImageJ software (National Institutes of Health).
To ensure reproducible anatomical reduction during plating, a 3.5-mm 4-hole nonlocking periarticular anatomically contoured plate (Zimmer Biomet) was applied posteriorly to the intact olecranon through a longitudinal slit in the distal triceps tendon. The plate was predrilled to house 4 nonlocking screws, 2 proximal and 2 distal.
Fracture Generation and Testing of Fixation Constructs
Analysis
ImageJ software was used to analyze the C-arm radiographs. Measurements were divided into 4 groups of joint surface loss caused by the resections: 0% to 20%, 20% to 40%, 40% to 60%, and >60%. Differences in ROM between the BP and AS constructs were analyzed with a Wilcoxon signed rank test with statistical significance set at P < .05 (Prism 6; GraphPad Software).
Results
As many as 6 serial resections were made before the proximal fragment of the olecranon was judged too small to be secured to a plate with at least 2 screws. Only 7 specimens were large enough for the fifth cut, and only 4 were large enough for the sixth cut. After the final resection, mean loss of olecranon length was 77.3% (range, 63.7%-88%; median, 80.6%). All elbow specimens remained stable to manual valgus and varus testing in full extension, 30° of flexion, and full flexion in both supination and pronation. There was no medial or lateral opening of the ulnohumeral joint on fluoroscopy throughout testing, for either the BP or the AS constructs. There was no anterior or posterior subluxation throughout the entire ROM.
Discussion
Our goal in this study was to determine the maximum articular surface loss that can be tolerated before a BP construct becomes unstable. This finding applies to situations in which the degree of comminution makes reconstruction of the articular surface impossible. Contrary to our hypothesis, the ulnohumeral joint remained stable despite extensive loss of congruity within the sigmoid notch. In 1 specimen, the joint remained stable at 88% loss of olecranon. However, the 2 constructs had different ROM results: ROM was significantly lower at more resections with AS but remained unchanged from baseline with BP.
Dorsal plating has become standard treatment for comminuted olecranon fractures, and many studies, both clinical and biomechanical, have reported favorable results, good functional outcomes, and acceptable ROM.3,7,10,13,18-20,25 However, the multiple studies on the use of various plates in comminuted olecranon fractures did not address whether articular congruity was maintained during reductions or how much articular surface was reconstructed. Although we may reasonably assume larger studies included cases with some unmeasured loss of articular congruity, it is difficult to directly compare our findings with those of other studies. In addition, it is possible those studies did not include fractures that were deemed unfit for BP (because of very severe comminution) and underwent AS instead. Only 1 case series has focused on BP without complete articular reconstruction.8 The cases in that series had good outcomes with good stability—consistent with our finding of extreme comminution in a worst-case scenario.
Complete elbow stability after AS is consistent with findings in the literature.4,6,12,14,16 As AS is reserved for severely comminuted fractures and bone resections,21,23,26 our findings can be compared with the earlier findings. In AS, either the proximal pieces or the intermediate pieces are removed to create a smaller but congruent articular surface, with less concern for nonunion.21 When the proximal piece is removed, the triceps muscle is advanced to the ulnar shaft, creating a slinglike structure for the trochlea.4,11,16,23 When the intermediate piece is removed, the proximal piece is advanced to the shaft along with the triceps.12,14,27 In either technique, the triceps muscle is advanced distally, potentially affecting its extensibility and moment arm.23
Although small in numbers, case series and retrospective reviews have found that AS has good outcomes,4,14,16 whereas our study found significantly decreased ROM. A few patients in these studies lost ROM or triceps strength,12,14,16 but the cause, AS or fracture severity, is unclear. It is possible only 0% to 20% of the olecranon was resected in those cases, whereas our study found no significant change in ROM. It is also possible that cadaveric muscles do not stretch as well as muscles in vivo. Biomechanical studies have demonstrated changes in triceps stretch and strength,23,26 but perhaps these changes are subclinical or overcome with therapy and time.12,14 There are no data regarding whether patients who undergo AS (vs another fixation method) need more physical therapy. In extreme resection, some reduction in ROM is expected.13
The ulnohumeral joint is a primary static stabilizer of the elbow joint.28-30 Recent studies on the role of the ulnohumeral joint in elbow stability have focused mainly on the coronoid process in the setting of dislocation.28,29,31,32 According to these studies, 50% of the coronoid must remain intact for the elbow to be stable when all other stabilizers are intact.32 In our study, resections preserved the coronoid and the ligamentous stabilizers of the elbow. It is therefore possible that the elbow joint remained stable despite the considerable articular surface loss. Although the term ulnohumeral joint refers to both the coronoid and the remaining articular surface, our findings support the coronoid as a primary stabilizer and the remaining articular surface as a secondary static stabilizer.
This study had several limitations. First, its fractures were simulated by serial resection of only the middle portion of the olecranon. In reality, comminution could extend farther proximally or distally and involve the surrounding tissues, which help stabilize the elbow. However, our focus was on loss of articular surface and stability, so keeping surrounding structures intact avoided confounding factors that could contribute to stability. A second possible limitation is that the implant used here may be different from the implant used in a clinical setting. However, our focus was not on fixation quality, and stability alone should not be affected by plate type. Third, stability was measured not quantitatively but instead subjectively under manual stress and fluoroscopy. We chose this method because it mimics what happens during surgery and is the clinical standard for stability assessment.24 Fourth, soft-tissue properties of the cadaver models used in this biomechanical study may differ from soft-tissue properties in vivo. This study could not evaluate possible long-term complications, such as posttraumatic arthritis and heterotopic ossification.5,10 There are no long-term studies comparing BP and other olecranon fixation methods in terms of postoperative elbow arthritis.
Conclusion
The ulnohumeral joint can tolerate substantial articular surface loss without compromising stability. As a result, in the management of highly comminuted olecranon fractures, BP may be considered before AS is performed. Quality and amount of intact proximal bone, rather than degree of comminution, may be more important factors in deciding which fixation method to use.
This biomechanical study is the first to focus on olecranon fracture BP without complete reconstruction of the articular surface. When treating a highly comminuted olecranon fracture that has an unreconstructible articular surface, surgeons may consider BP with or without bone graft, as well as AS. Our study findings suggest that, though both constructs maintain elbow stability, BP may have the advantage of maintaining ROM too. BP can avoid effects on triceps and elbow ROM, which may be more important in younger, more active patients. Clinical correlates are needed to validate these findings, as overall outcomes may be affected by concurrent fractures and injuries to surrounding structures.
Take-Home Points
- The ulnohumeral joint can tolerate substantial articular surface loss without compromising stability.
- Consider BP as an alternative to AS in unreconstructable olecranon fractures.
- Both BP and AS of olecranon fractures maintain elbow stability.
- BP has the advantage of maintaining elbow range of motion.
Olecranon fractures constitute about 10% of all forearm fractures.1 Many are low-energy fractures in osteoporotic bone in the elderly.1,2 Unstable fractures require operative fixation in which the goal is restoration of articular congruity and stability.3 Various fixation methods are used to treat unstable olecranon fractures, and outcomes are good overall.3-21 However, severely comminuted olecranon fractures, especially in osteoporotic bone, pose a unique challenge, where reconstruction may not be feasible.9 Although the articular surface can be reconstructed in most cases, reconstruction is not feasible with severe comminution or low bone mineral density. When articular congruity is no longer possible, the primary goal of fixation becomes elbow stability. Postoperative stability is linked to favorable outcomes, as it allows patients to engage in early range-of-motion (ROM) exercises, which improves joint function.5,21,22
When treating these severely comminuted olecranon fractures, surgeons have 2 options: bridge plating (BP) and acute shortening (AS). In BP, a plate is used to restore the length of the olecranon. The plate is spanned over the comminuted segment with fixation at proximal and distal pieces but without open reduction of the comminuted pieces.8 This process may be performed with or without bone grafting.21 Although any bony defect between the proximal and distal pieces may be filled, there is now a gap in articular congruity within the sigmoid notch. One concern with this fixation method is that joint stability is lost when this gap becomes too large. Surgeons therefore may decide to forgo BP and perform AS instead, as long as the coronoid is intact.21 In AS, often referred to as olecranon excision, comminuted fragments are removed and the triceps muscle advanced distally. AS constructs, often reserved for older, less active patients, yield acceptable results in this population.5 However, the long-term effects of AS in young, active patients are unclear, and biomechanical studies suggest reduced triceps muscle strength.23
Surgeons have had no studies guiding them in deciding which construct to use, BP or AS, in severely comminuted olecranon fractures in which the articular surface cannot be reconstructed.
We conducted a biomechanical study to determine the percentage loss of articular surface at which a BP construct becomes significantly clinically unstable. We also compared BP stability and AS stability for each percentage loss of articular surface and compared initial elbow ROM with the 2 methods. We hypothesized that, at a certain percentage loss of articular congruity, the BP construct would become too unstable and would require conversion to the AS construct.
Materials and Methods
Specimen Preparation
Eight fresh-frozen paired cadaveric upper limbs (2 male, 2 female; mean age, 61.8 years; age range, 56-74 years) were obtained from donors with no history of elbow trauma or prior surgery. Specimens were stored at –20°C, thawed to room temperature before testing, and, using clinical and radiographic evaluation, screened for abnormalities.
Each specimen was positioned with the arm draped in the lateral decubitus position, as in typical olecranon fracture surgery. A standard posterior approach to the olecranon was made with a midline posterior longitudinal skin incision. Subcutaneous flaps were developed, and the subcutaneous border of the proximal olecranon was exposed, preserving the medial and lateral collateral ligaments as well as the extensor mechanism. Baseline maximum flexion and extension of the elbow as well as olecranon length were measured with fluoroscopy (BV Pulsera, Philips) and ImageJ software (National Institutes of Health).
To ensure reproducible anatomical reduction during plating, a 3.5-mm 4-hole nonlocking periarticular anatomically contoured plate (Zimmer Biomet) was applied posteriorly to the intact olecranon through a longitudinal slit in the distal triceps tendon. The plate was predrilled to house 4 nonlocking screws, 2 proximal and 2 distal.
Fracture Generation and Testing of Fixation Constructs
Analysis
ImageJ software was used to analyze the C-arm radiographs. Measurements were divided into 4 groups of joint surface loss caused by the resections: 0% to 20%, 20% to 40%, 40% to 60%, and >60%. Differences in ROM between the BP and AS constructs were analyzed with a Wilcoxon signed rank test with statistical significance set at P < .05 (Prism 6; GraphPad Software).
Results
As many as 6 serial resections were made before the proximal fragment of the olecranon was judged too small to be secured to a plate with at least 2 screws. Only 7 specimens were large enough for the fifth cut, and only 4 were large enough for the sixth cut. After the final resection, mean loss of olecranon length was 77.3% (range, 63.7%-88%; median, 80.6%). All elbow specimens remained stable to manual valgus and varus testing in full extension, 30° of flexion, and full flexion in both supination and pronation. There was no medial or lateral opening of the ulnohumeral joint on fluoroscopy throughout testing, for either the BP or the AS constructs. There was no anterior or posterior subluxation throughout the entire ROM.
Discussion
Our goal in this study was to determine the maximum articular surface loss that can be tolerated before a BP construct becomes unstable. This finding applies to situations in which the degree of comminution makes reconstruction of the articular surface impossible. Contrary to our hypothesis, the ulnohumeral joint remained stable despite extensive loss of congruity within the sigmoid notch. In 1 specimen, the joint remained stable at 88% loss of olecranon. However, the 2 constructs had different ROM results: ROM was significantly lower at more resections with AS but remained unchanged from baseline with BP.
Dorsal plating has become standard treatment for comminuted olecranon fractures, and many studies, both clinical and biomechanical, have reported favorable results, good functional outcomes, and acceptable ROM.3,7,10,13,18-20,25 However, the multiple studies on the use of various plates in comminuted olecranon fractures did not address whether articular congruity was maintained during reductions or how much articular surface was reconstructed. Although we may reasonably assume larger studies included cases with some unmeasured loss of articular congruity, it is difficult to directly compare our findings with those of other studies. In addition, it is possible those studies did not include fractures that were deemed unfit for BP (because of very severe comminution) and underwent AS instead. Only 1 case series has focused on BP without complete articular reconstruction.8 The cases in that series had good outcomes with good stability—consistent with our finding of extreme comminution in a worst-case scenario.
Complete elbow stability after AS is consistent with findings in the literature.4,6,12,14,16 As AS is reserved for severely comminuted fractures and bone resections,21,23,26 our findings can be compared with the earlier findings. In AS, either the proximal pieces or the intermediate pieces are removed to create a smaller but congruent articular surface, with less concern for nonunion.21 When the proximal piece is removed, the triceps muscle is advanced to the ulnar shaft, creating a slinglike structure for the trochlea.4,11,16,23 When the intermediate piece is removed, the proximal piece is advanced to the shaft along with the triceps.12,14,27 In either technique, the triceps muscle is advanced distally, potentially affecting its extensibility and moment arm.23
Although small in numbers, case series and retrospective reviews have found that AS has good outcomes,4,14,16 whereas our study found significantly decreased ROM. A few patients in these studies lost ROM or triceps strength,12,14,16 but the cause, AS or fracture severity, is unclear. It is possible only 0% to 20% of the olecranon was resected in those cases, whereas our study found no significant change in ROM. It is also possible that cadaveric muscles do not stretch as well as muscles in vivo. Biomechanical studies have demonstrated changes in triceps stretch and strength,23,26 but perhaps these changes are subclinical or overcome with therapy and time.12,14 There are no data regarding whether patients who undergo AS (vs another fixation method) need more physical therapy. In extreme resection, some reduction in ROM is expected.13
The ulnohumeral joint is a primary static stabilizer of the elbow joint.28-30 Recent studies on the role of the ulnohumeral joint in elbow stability have focused mainly on the coronoid process in the setting of dislocation.28,29,31,32 According to these studies, 50% of the coronoid must remain intact for the elbow to be stable when all other stabilizers are intact.32 In our study, resections preserved the coronoid and the ligamentous stabilizers of the elbow. It is therefore possible that the elbow joint remained stable despite the considerable articular surface loss. Although the term ulnohumeral joint refers to both the coronoid and the remaining articular surface, our findings support the coronoid as a primary stabilizer and the remaining articular surface as a secondary static stabilizer.
This study had several limitations. First, its fractures were simulated by serial resection of only the middle portion of the olecranon. In reality, comminution could extend farther proximally or distally and involve the surrounding tissues, which help stabilize the elbow. However, our focus was on loss of articular surface and stability, so keeping surrounding structures intact avoided confounding factors that could contribute to stability. A second possible limitation is that the implant used here may be different from the implant used in a clinical setting. However, our focus was not on fixation quality, and stability alone should not be affected by plate type. Third, stability was measured not quantitatively but instead subjectively under manual stress and fluoroscopy. We chose this method because it mimics what happens during surgery and is the clinical standard for stability assessment.24 Fourth, soft-tissue properties of the cadaver models used in this biomechanical study may differ from soft-tissue properties in vivo. This study could not evaluate possible long-term complications, such as posttraumatic arthritis and heterotopic ossification.5,10 There are no long-term studies comparing BP and other olecranon fixation methods in terms of postoperative elbow arthritis.
Conclusion
The ulnohumeral joint can tolerate substantial articular surface loss without compromising stability. As a result, in the management of highly comminuted olecranon fractures, BP may be considered before AS is performed. Quality and amount of intact proximal bone, rather than degree of comminution, may be more important factors in deciding which fixation method to use.
This biomechanical study is the first to focus on olecranon fracture BP without complete reconstruction of the articular surface. When treating a highly comminuted olecranon fracture that has an unreconstructible articular surface, surgeons may consider BP with or without bone graft, as well as AS. Our study findings suggest that, though both constructs maintain elbow stability, BP may have the advantage of maintaining ROM too. BP can avoid effects on triceps and elbow ROM, which may be more important in younger, more active patients. Clinical correlates are needed to validate these findings, as overall outcomes may be affected by concurrent fractures and injuries to surrounding structures.
1. Court-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury. 2006;37(8):691-697.
2. Duckworth AD, Clement ND, Aitken SA, Court-Brown CM, McQueen MM. The epidemiology of fractures of the proximal ulna. Injury. 2012;43(3):343-346.
3. Bailey CS, MacDermid J, Patterson SD, King GJ. Outcome of plate fixation of olecranon fractures. J Orthop Trauma. 2001;15(8):542-548.
4. Adler S, Fay GF, Macausland WR Jr. Treatment of olecranon fractures. Indications for excision of the olecranon fragment and repair of the triceps tendon. J Trauma. 1962;2:597-602.
5. Baecher N, Edwards S. Olecranon fractures. J Hand Surg Am. 2013;38(3):593-604.
6. Bell TH, Ferreira LM, McDonald CP, Johnson JA, King GJW. Contribution of the olecranon to elbow stability: an in vitro biomechanical study. J Bone Joint Surg Am. 2010;92(4):949-957.
7. Buijze G, Kloen P. Clinical evaluation of locking compression plate fixation for comminuted olecranon fractures. J Bone Joint Surg Am. 2009;91(10):2416-2420.
8. Cervera-Irimia J, Tomé-Bermejo F, Gómez-Bermejo MA, Holgado-Moreno E, Stratenwerth EG. Treatment of comminuted olecranon fractures with olecranon plate and structural iliac crest graft. Acta Orthop Belg. 2012;78(6):703-707.
9. Edwards SG, Martin BD, Fu RH, et al. Comparison of olecranon plate fixation in osteoporotic bone: do current technologies and designs make a difference? J Orthop Trauma. 2011;25(5):306-311.
10. Erturer RE, Sever C, Sonmez MM, Ozcelik IB, Akman S, Ozturk I. Results of open reduction and plate osteosynthesis in comminuted fracture of the olecranon. J Shoulder Elbow Surg. 2011;20(3):449-454.
11. Estourgie RJ, Tinnemans JG. Treatment of grossly comminuted fractures of the olecranon by excision. Neth J Surg. 1982;34(3):127-129.
12. Fern ED, Brown JN. Olecranon advancement osteotomy in the management of severely comminuted olecranon fractures. Injury. 1993;24(4):267-269.
13. Gordon MJ, Budoff JE, Yeh ML, Luo ZP, Noble PC. Comminuted olecranon fractures: a comparison of plating methods. J Shoulder Elbow Surg. 2006;15(1):94-99.
14. Iannuzzi N, Dahners L. Excision and advancement in the treatment of comminuted olecranon fractures. J Orthop Trauma. 2009;23(3):226-228.
15. Ikeda M, Fukushima Y, Kobayashi Y, Oka Y. Comminuted fractures of the olecranon. Management by bone graft from the iliac crest and multiple tension-band wiring. J Bone Joint Surg Br. 2001;83(6):805-808.
16. McKeever FM, Buck RM. Fracture of the olecranon process of the ulna; treatment by excision of fragment and repair of triceps tendon. JAMA. 1947;135(1):1-5.
17. Rommens PM, Küchle R, Schneider RU, Reuter M. Olecranon fractures in adults: factors influencing outcome. Injury. 2004;35(11):1149-1157.
18. Siebenlist S, Torsiglieri T, Kraus T, Burghardt RD, Stöckle U, Lucke M. Comminuted fractures of the proximal ulna—preliminary results with an anatomically preshaped locking compression plate (LCP) system. Injury. 2010;41(12):1306-1311.
19. Tarallo L, Mugnai R, Adani R, Capra F, Zambianchi F, Catani F. Simple and comminuted displaced olecranon fractures: a clinical comparison between tension band wiring and plate fixation techniques. Arch Orthop Trauma Surg. 2014;134(8):1107-1114.
20. Wang Y, Tao R, Xu H, Cao Y, Zhou Z, Xu S. Mid-term outcomes of contoured plating for comminuted fractures of the olecranon. Orthop Surg. 2011;3(3):176-180.
21. Newman SD, Mauffrey C, Krikler S. Olecranon fractures. Injury. 2009;40(6):575-581.
22. Boyer MI, Galatz LM, Borrelli J, Axelrod TS, Ricci WM. Intra-articular fractures of the upper extremity: new concepts in surgical treatment. Instr Course Lect. 2003;52:591-605.
23. Didonna ML, Fernandez JJ, Lim TH, Hastings H, Cohen MS. Partial olecranon excision: the relationship between triceps insertion site and extension strength of the elbow. J Hand Surg Am. 2003;28(1):117-122.
24. Trumble T, Cornwall R, Budoff J. Core Knowledge in Orthopaedics: Hand, Elbow, and Shoulder. Philadelphia, PA: Mosby; 2006.
25. Simpson NS, Goodman LA, Jupiter JB. Contoured LCDC plating of the proximal ulna. Injury. 1996;27(6):411-417.
26. Ferreira LM, Bell TH, Johnson JA, King GJ. The effect of triceps repair techniques following olecranon excision on elbow stability and extension strength: an in vitro biomechanical study. J Orthop Trauma. 2011;25(7):420-424.
27. Colton CL. Fractures of the olecranon in adults: classification and management. Injury. 1973;5(2):121-129.
28. Hull JR, Owen JR, Fern SE, Wayne JS, Boardman ND 3rd. Role of the coronoid process in varus osteoarticular stability of the elbow. J Shoulder Elbow Surg. 2005;14(4):441-446.
29. Morrey BF, An KN. Stability of the elbow: osseous constraints. J Shoulder Elbow Surg. 2005;14(1 suppl S):174S-178S.
30. Williams G, Ramsey M, Wiesel S. Operative Techniques in Shoulder and Elbow Surgery. Philadelphia, PA: Lippincott Williams & Wilkins; 2011.
31. Schneeberger AG, Sadowski MM, Jacob HA. Coronoid process and radial head as posterolateral rotatory stabilizers of the elbow. J Bone Joint Surg Am. 2004;86(5):975-982.
32. Closkey RF, Goode JR, Kirschenbaum D, Cody RP. The role of the coronoid process in elbow stability. A biomechanical analysis of axial loading. J Bone Joint Surg Am. 2000;82(12):1749-1753.
1. Court-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury. 2006;37(8):691-697.
2. Duckworth AD, Clement ND, Aitken SA, Court-Brown CM, McQueen MM. The epidemiology of fractures of the proximal ulna. Injury. 2012;43(3):343-346.
3. Bailey CS, MacDermid J, Patterson SD, King GJ. Outcome of plate fixation of olecranon fractures. J Orthop Trauma. 2001;15(8):542-548.
4. Adler S, Fay GF, Macausland WR Jr. Treatment of olecranon fractures. Indications for excision of the olecranon fragment and repair of the triceps tendon. J Trauma. 1962;2:597-602.
5. Baecher N, Edwards S. Olecranon fractures. J Hand Surg Am. 2013;38(3):593-604.
6. Bell TH, Ferreira LM, McDonald CP, Johnson JA, King GJW. Contribution of the olecranon to elbow stability: an in vitro biomechanical study. J Bone Joint Surg Am. 2010;92(4):949-957.
7. Buijze G, Kloen P. Clinical evaluation of locking compression plate fixation for comminuted olecranon fractures. J Bone Joint Surg Am. 2009;91(10):2416-2420.
8. Cervera-Irimia J, Tomé-Bermejo F, Gómez-Bermejo MA, Holgado-Moreno E, Stratenwerth EG. Treatment of comminuted olecranon fractures with olecranon plate and structural iliac crest graft. Acta Orthop Belg. 2012;78(6):703-707.
9. Edwards SG, Martin BD, Fu RH, et al. Comparison of olecranon plate fixation in osteoporotic bone: do current technologies and designs make a difference? J Orthop Trauma. 2011;25(5):306-311.
10. Erturer RE, Sever C, Sonmez MM, Ozcelik IB, Akman S, Ozturk I. Results of open reduction and plate osteosynthesis in comminuted fracture of the olecranon. J Shoulder Elbow Surg. 2011;20(3):449-454.
11. Estourgie RJ, Tinnemans JG. Treatment of grossly comminuted fractures of the olecranon by excision. Neth J Surg. 1982;34(3):127-129.
12. Fern ED, Brown JN. Olecranon advancement osteotomy in the management of severely comminuted olecranon fractures. Injury. 1993;24(4):267-269.
13. Gordon MJ, Budoff JE, Yeh ML, Luo ZP, Noble PC. Comminuted olecranon fractures: a comparison of plating methods. J Shoulder Elbow Surg. 2006;15(1):94-99.
14. Iannuzzi N, Dahners L. Excision and advancement in the treatment of comminuted olecranon fractures. J Orthop Trauma. 2009;23(3):226-228.
15. Ikeda M, Fukushima Y, Kobayashi Y, Oka Y. Comminuted fractures of the olecranon. Management by bone graft from the iliac crest and multiple tension-band wiring. J Bone Joint Surg Br. 2001;83(6):805-808.
16. McKeever FM, Buck RM. Fracture of the olecranon process of the ulna; treatment by excision of fragment and repair of triceps tendon. JAMA. 1947;135(1):1-5.
17. Rommens PM, Küchle R, Schneider RU, Reuter M. Olecranon fractures in adults: factors influencing outcome. Injury. 2004;35(11):1149-1157.
18. Siebenlist S, Torsiglieri T, Kraus T, Burghardt RD, Stöckle U, Lucke M. Comminuted fractures of the proximal ulna—preliminary results with an anatomically preshaped locking compression plate (LCP) system. Injury. 2010;41(12):1306-1311.
19. Tarallo L, Mugnai R, Adani R, Capra F, Zambianchi F, Catani F. Simple and comminuted displaced olecranon fractures: a clinical comparison between tension band wiring and plate fixation techniques. Arch Orthop Trauma Surg. 2014;134(8):1107-1114.
20. Wang Y, Tao R, Xu H, Cao Y, Zhou Z, Xu S. Mid-term outcomes of contoured plating for comminuted fractures of the olecranon. Orthop Surg. 2011;3(3):176-180.
21. Newman SD, Mauffrey C, Krikler S. Olecranon fractures. Injury. 2009;40(6):575-581.
22. Boyer MI, Galatz LM, Borrelli J, Axelrod TS, Ricci WM. Intra-articular fractures of the upper extremity: new concepts in surgical treatment. Instr Course Lect. 2003;52:591-605.
23. Didonna ML, Fernandez JJ, Lim TH, Hastings H, Cohen MS. Partial olecranon excision: the relationship between triceps insertion site and extension strength of the elbow. J Hand Surg Am. 2003;28(1):117-122.
24. Trumble T, Cornwall R, Budoff J. Core Knowledge in Orthopaedics: Hand, Elbow, and Shoulder. Philadelphia, PA: Mosby; 2006.
25. Simpson NS, Goodman LA, Jupiter JB. Contoured LCDC plating of the proximal ulna. Injury. 1996;27(6):411-417.
26. Ferreira LM, Bell TH, Johnson JA, King GJ. The effect of triceps repair techniques following olecranon excision on elbow stability and extension strength: an in vitro biomechanical study. J Orthop Trauma. 2011;25(7):420-424.
27. Colton CL. Fractures of the olecranon in adults: classification and management. Injury. 1973;5(2):121-129.
28. Hull JR, Owen JR, Fern SE, Wayne JS, Boardman ND 3rd. Role of the coronoid process in varus osteoarticular stability of the elbow. J Shoulder Elbow Surg. 2005;14(4):441-446.
29. Morrey BF, An KN. Stability of the elbow: osseous constraints. J Shoulder Elbow Surg. 2005;14(1 suppl S):174S-178S.
30. Williams G, Ramsey M, Wiesel S. Operative Techniques in Shoulder and Elbow Surgery. Philadelphia, PA: Lippincott Williams & Wilkins; 2011.
31. Schneeberger AG, Sadowski MM, Jacob HA. Coronoid process and radial head as posterolateral rotatory stabilizers of the elbow. J Bone Joint Surg Am. 2004;86(5):975-982.
32. Closkey RF, Goode JR, Kirschenbaum D, Cody RP. The role of the coronoid process in elbow stability. A biomechanical analysis of axial loading. J Bone Joint Surg Am. 2000;82(12):1749-1753.
