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Open Reduction and Internal Fixation of Distal Humerus Fractures
Open Reduction and Internal Fixation of Distal Humerus Fractures Danny P. Goel, MD, FRCSC, Jeffrey M. Pike, MD, FRCSC, and George S. Athwal, MD, FRCSC Distal humerus fractures are common and represent 2% of all fractures and approximately 30% of those affecting the humerus. The management of distal humerus fractures is complicated by the complex 3-dimensional anatomy of the elbow, the limited bone stock for internal fixation, and often comminuted and osteopenic nature of the articular segment. Surgical treatment should be conducted in a systematic manner to minimize complications. Using the principles of anatomic articular reconstruction with stable fixation to allow early range to motion, good to satisfactory outcomes can be expected in most patients. Oper Tech Orthop 20:24-33 © 2010 Elsevier Inc. All rights reserved. KEYWORDS distal humerus fracture, open reduction and internal fixation, supracondylar, intracondylar, fracture
F
ractures of the distal humerus represent challenging problems to the modern orthopaedic surgeon. Important factors to consider are the 3-dimensional geometry, limited peri-articular bone stock for internal fixation, intra-articular comminution, and the need for early mobilization. The increasing incidence of this fracture in the elderly patient in association with poor bone quality and comminution has introduced a significant challenge to the reconstructive surgeon. Historically, distal humeral fractures (DHF) were treated nonoperatively1 due to the poor results of surgery. Surgery was complicated by high infection rates and poor fixation due to rudimentary implants. Although nonoperative care may be appropriate in some situations, the modern literature strongly supports open reduction and internal fixation (ORIF) of intra-articular distal humerus fractures.2-10 The surgical goals are to obtain anatomic restoration of the articular surface and recreation of joint alignment with stable internal fixation, secure enough to allow early range of motion. This review will focus on the surgical anatomy, the mechanism of injury, classification systems, surgical exposures, and fixation techniques relevant to the operative management of distal humerus fractures.
Hand and Upper Limb Centre, St. Joseph’s Health Care, University of Western Ontario, London, Canada. Address reprint requests to George S. Athwal, MD, FRCSC, Hand and Upper Limb Centre, St. Joseph’s Health Care, University of Western Ontario, 268 Grosvenor St, London, Canada N6A 4L6. E-mail: gathwal@ uwo.ca
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1048-6666/10/$-see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1053/j.oto.2009.09.010
Anatomical Considerations A single synovial joint encompasses 3 separate articulations; ulnohumeral, proximal radioulnar, and radiocapitellar. These articulations permit elbow flexion-extension, pronation-supination, and to a minimal extent varus– valgus.11 Anatomic restoration of these multiple articulations ideally should allow loads of 0.3 to 0.5 times body weight12 or substantially more load as observed in a simple push-up.13 An understanding of the bony and ligamentous anatomy is important to avoid iatrogenic complications. The distal humerus can be thought of as a 2 column structure supporting the articular segment. The distal portion of the lateral column (capitellum) projects anteriorly approximately 35 to 40 degrees. The medial column terminates at the medial epicondyle and, in contrast, does not curve anterior. The anatomy of the trochlea is analogous to that of a spool with distal articular segment oriented at 4 to 8 degrees of valgus relative to the long axis of the humerus. Furthermore, this distal articular segment is internally rotated 3 to 4 degrees relative to the trans-epicondylar axis.14 Understanding the ligamentous anatomy is critical during exposure and plate application to avoid iatrogenic injury. The anterior bundle of the medial collateral ligament, a primary elbow stabilizer, originates on the anteroinferior aspect of the medial epicondyle and inserts onto the sublime tubercle of the ulna. The medial column and medial epicondyle, therefore, can accommodate plate placement without impinging on the MCL origin. The lateral ulnar collateral ligament, the primary lateral stabilizer, origi-
Distal humerus fractures nates and inserts on the lateral epicondyle and crista supinatoris, respectively. Identification and protection of the lateral collateral ligament origin allows visualization of the posterior aspect of the radiocapitellar joint and safe lateral plate application.15,16
Epidemiology/Mechanism of Injury Distal humerus fractures represent 2% of all fractures and approximately 30% of those involving the humerus.17 A population-based study examining all patients presenting to a single center identified a bimodal distribution with peak occurrences in young males (12-19 years) and elderly females (⬎80 years). Robinson et al18 identified an incidence of 5.7 of 100,000 in the population per year with a nearly equivalent male-to-female ratio.18 Palvanen19 retrospectively reviewed the Finnish National Hospital Discharge Register for surgically treated distal humerus fractures between 1970 and 1995. Over 25-year period, the incidence of distal humerus fractures among patients greater than 60 years of age nearly tripled (11-30%). Furthermore, the incidence in 2030 was projected to be 52 of 100, 000.19 This equates to an absolute value of 440 fractures per year within this single Finnish population.19 Motorized vehicles and extreme sports contribute to the severity and incidence of distal humerus fractures in the young. By contrast, elderly patients generally present following a low-energy ground level fall.
Fracture Classification Commonly mentioned classification systems for distal humerus fractures include the Riseborough and Radin,1 Jupiter and Mehne,20 and the AO/OTA (orthopedic trauma association)comprehensive classification.21 In 1969, Riseborough and Radin1 described intra-articular distal humerus fractures as T-shaped intercondylar, and classified them on the basis of rotation, displacement, and comminution of segments. The AO/OTA classification is an alphanumeric system dividing fractures according to degree of articular involvement. The humerus is labeled as 1 and as 3 (which identifies the distal segment of all long bones). This is further subgrouped into A (articular), B (partial articular), and C (complete articular). Each subgroup can be further classified on the basis of the fracture line and comminution where 1 represents minimal fragmentation and 3 severe comminution. The Jupiter and Mehne20 classification attempted to resolve the limitations of previous classifications through an anatomic and treatment-based system. They divided their system into intra-articular, extra-articular (intracapsular), and extracapsular fractures. The intracapsular fractures are subdivided into A-D as single column, bicolumnar, and capitellar and trochlear involvement.20 In addition to being the official classification of the OTA, it is the authors’ opinion that the AO/OTA classification is more intuitive and ubiquitous. To date, the AO/ OTA classification has demonstrated the highest inter- and
25 intraobserver reliability while also being the most inclusive of fracture types.22
Imaging Standard anteroposterior and lateral radiographs are sufficient for classification and preoperative planning. Computed tomography with 3-dimensional reconstructions, although not required for all cases, can improve fracture identification and classification. Doornberg et al23 examined the utility of 3-dimensional computed tomography in the evaluation of distal humerus fractures. They found improved inter- and intraobserver reliability within the Jupiter/Mehne20 and AO/OTA classifications. Interestingly, 3-dimensional images improved the reliability, but not the accuracy, of fracture identification and classification.
Surgical Exposures The selection of a surgical approach for the management of distal humerus fractures is dependent on several factors. These include the surgeon’s experience and preferences, fracture pattern, degree of articular involvement, associated soft tissue injury, rehabilitation protocols, and whether intraoperative conversion to arthroplasty is contemplated. The ideal approach for each individual fracture should provide adequate visualization to allow anatomic reduction and the application of internal fixation to maintain elbow stability with minimization of soft tissue and bone disruption to permit early motion. Several surgical approaches will be discussed with their strengths and limitations highlighted. Approaches to the distal humerus can be categorized into olecranon osteotomies, triceps sparing (triceps-on), triceps splitting, and triceps reflecting (triceps-off). Visualization of the distal humerus articular segment varies with each approach. The triceps splitting, triceps reflecting, and olecranon osteotomy expose 35%, 46%, and 57% of the distal articular segment, respectively.24 A thorough review of elbow anatomy and detailed approaches has been previously documented.25 However, for this review we will highlight some important issues surrounding each approach.
Olecranon Osteotomy With several modifications of MacAusland’s26 original description, the olecranon osteotomy is the authors’ most commonly used approach for management of complex intra-articular DHF, as it affords the best visualization of the articular segment. The outcomes after this approach, however, can be complicated by malunion, nonunion, and hardware concerns.24 Hewins et al27 describe the steps required to minimize postoperative complications after the creation of an olecranon osteotomy. These include precontouring and fixation of a 3.5 mm reconstruction plate to the olecranon with screws directed ulnarly to avoid the proximal radio-ulnar joint, identification of the bare spot through medial and min-
D.P. Goel, J.M. Pike, and G.S. Athwal
26 imal lateral dissection and maintenance of subchondral bone before completion of osteotomy.27 Triceps weakness after olecranon osteotomy when compared with the contralateral limb has been shown,27 however, when compared with a triceps splitting approach, no discernible weakness was identified.28 Coles et al28 reported their 6 year follow-up results of patients undergoing an olecranon osteotomy. In their retrospective review, 46 patients were surgically treated with intramedullary screw supplemented with dorsal ulnar wiring and 24 patients with plate fixation. They reported no nonunions, 1 delayed union, 2 hardware revisions, and 13 hardware removals. Most hardware removals (11 patients) were associated with a secondary procedure (capsular release for stiffness).28
Triceps Sparing (Triceps-On) or Bilaterotricipital Approach Alonso-Llames29 described the bilaterotricipital approach for the treatment of pediatric supracondylar fractures. This approach avoids any disruption of the extensor mechanism insertion on the olecranon using surgical windows along the medial and lateral sides of the triceps (Fig. 1). The main advantages of this approach are the avoidance of an osteotomy and maintenance of triceps integrity to allow early active motion. An additional advantage of this approach is that it allows easy intraoperative conversion to a total elbow arthroplasty (TEA) if stable ORIF is deemed unlikely. Distal extension of the lateral window into the Boyd approach assists with intra-articular exposure. The main disadvantage of this approach is the limited visualization of the articular segment.
This approach is best reserved for extra-articular fractures or simple intra-articular fractures with minimal comminution (Fig. 2).
Triceps Splitting Campbell30 described the triceps splitting approach for exposure of the distal humerus in 1932. It involves a distal midline triceps tendon split with equal portions of the triceps tendon and its insertion on the olecranon reflected medially and laterally. Wilkinson and Stanley24 in their comparative study of posterior elbow approaches reported that only 35% of the distal humerus articular segment could be visualized with the triceps split, which does limit its usefulness. McKee et al31 compared the olecranon osteotomy to the triceps split for DHF and found no difference in functional outcomes at follow-up.
Bryan-Morrey Approach The Bryan-Morrey32 approach is used commonly for TEA and can also be used for fixation of distal humerus fractures. This exposure permits good exposure of the distal humerus by reflecting the triceps tendon and its insertion from medial to lateral. The reflected triceps tendon maintains its attachment to the ulnar periosteum and anconeus thereby preserving its length. The main advantage of this approach is that it avoids the complications associated with an olecranon osteotomy. Reported disadvantages include complications, such as failure of the extensor mechanism repair and extensor weakness.
Figure 1 The bilaterotricipital approach (triceps-on) described by Alonso-Llames29 allows bi-column plating of the distal humerus. The main advantage of this approach is that it does not disrupt the extensor mechanism. The main disadvantage is the limited visualization of the articular surface. Lateral (A) and medial (B) plates applied through the bilaterotricipital approach.
Distal humerus fractures
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Figure 2 The bilaterotricipital approach may be used for fixation of trans-condylar and simple intra-articular fractures. Radiographs (A, B) of an AO/OTA type C1 fracture fixated with precontoured parallel plates (C, D).
Triceps Reflecting Anconeus Pedicle The triceps reflecting anconeus pedicle approach, as its name implies, reflects the anconeus and entire triceps insertion proximally without violating the olecranon.33 This exposure preserves the innervation of the anconeus muscle, therefore, maintaining its role as a dynamic varus and posterolateral stabilizer.33 The main advantage of this approach is that it avoids the complications inherent with the olecranon osteotomy. The main disadvantage is the possibility of triceps
weakness or repair dehiscence. In the authors’ practice, this approach is used rarely.
Management Non-operative Non-operative care in the management of distal humerus fractures was recommended as 1969 by Riseborough and Radin.1 Brown and Morgan,34 in 1971, treated 10 intra-artic-
28 ular distal humerus fractures nonoperatively with early mobilization and noted an arc of motion of 100 degrees in most of their patients. This “bag of bones” treatment has been posed as a reasonable treatment option in select patients.35 Non-surgical care of distal humerus fractures may be considered in those patients medically unfit for surgery, with low functional demands or neurological impairment. Although nonoperative care may be recommended in certain special situations, most patients have superior functional outcomes after operative treatment.2-10
Operative Management To appreciate current trends in distal humerus fracture management, an understanding of implant biomechanics is required, including plate configuration and fixation type. Although percutaneous Kirschner wire fixation has been regarded as the treatment of choice for pediatric supracondylar fractures,36,37 it is not recommended for distal humerus fractures in the adult population. Plate fixation with screws is the most acceptable form of treatment in adults, however, several factors are important when considering plate configuration. These factors include the type of fracture, the quality of the bone, the modulus of the implant and the location of the implant on the bone. The modulus of elasticity of the implant has been mentioned as being less important than the actual configuration of the plating system.38 Several different plating configurations exist, as plates may be applied orthogonally (90/90), in a parallel fashion or both (triple plating). Controversy exists on which plating configuration is ideal. To date, no one type of plating configuration has demonstrated clinical superiority in a comparative study. Plate Types Several different plate types have been used in the past, presently 3 general options exist, 3.5 mm standard straight plates that are intraoperatively contoured, fracture specific precontoured plates, and precontoured locking plates. Thinner plates (one-third tubular) or screw-only fixation are not recommended. The use of locking plates in other fractures, such as fractures of the proximal tibia,39 distal femur40,41 and unstable distal radius fractures,42 has obviated the need for bicolumnar fixation. In distal humerus fractures, however, this does not hold true. Tejwani et al43 evaluated single column locked plate fixation compared with double column reconstruction plates and found the latter to be more resistant to loads. Schuster et al44 evaluated a similar construct with 3 different plate configurations [reconstruction plate, locking compression plate, Synthes, GmbH, Solothurn, Switzerland] and the anatomically precontoured distal humerus plate (DHP, Synthes GmbH, Solothurn, Switzerland). They observed no difference in stiffness testing in extension or flexion. However, as bone mineral density decreased, the number of hardware failures increased in the reconstruction plate, whereas none were observed in the DHP. Although not stated, this study may suggest the value of precontoured locking constructs in the management of osteoporotic fractures.44 The lack of specific recommendations regarding optimal plate type and configuration is inherent in the literature.
D.P. Goel, J.M. Pike, and G.S. Athwal However, adherence to a principle-based approach with emphasis on articular reduction and double column rigid fixation to the metaphyseal segment is highly recommended.45 Fixation Approach. A principle-based approach to the management of distal humerus fractures is recommended. This form of treatment relies on 2 basic principles: articular reconstruction followed by column reconstruction. Articulator Reconstruction. The principles of peri-articular fracture fixation include restoration of the articular segment, column realignment and rigid fixation to allow for early mobilization. Preliminary fixation of the articular segment may be performed with Kirschner wires (K-wires) (Fig. 3). Several K-wires may be required for temporary fixation, therefore, they should be placed strategically taking in to consideration final plate and screw position. The main fragments of the articular segment can be fixated by 2 methods. The first method involves the placement of a central spool screw down the axis of the trochlea to fixate the 2 main fragments. Another method involves provisional fixation of the articular segment with K-wires followed by definitive fixation with screws placed through medial and lateral plates applied in a parallel manner (Fig. 4). In cases with articular comminution, the comminuted minor fragments can be fixated to the major fragments with threaded K-wires, headless compression screws or bioabsorbable pins. Coronal shear fractures of the capitellum, trochlea, or both may occur in association with distal humerus fractures. These coronal shear fragments can be visualized by internally rotating each condyle. This allows fixation of the coronal shear fracture and than subsequent fixation of the primary sagittal plane articular fracture. In situations where articular segments are absent, a principle-based approach is once again important. Restoration of joint range of motion is primarily dependent on the medial and lateral ridges of the trochlea. Therefore, loss of the midportion of the trochlea or the posterior articular surface, although important, is not entirely necessary for stability. Column Reconstruction Once the articular segment has been provisionally fixed, it must be rigidly linked to the humeral diaphysis. Provisional fixation of the articular segment to the diaphysis may be performed with K-wires inserted retrograde from distal to proximal. As mentioned, several different plating techniques exist, including orthogonal plating (90:90), parallel plating, and triple plating. All 3 techniques have been supported clinically and none have demonstrated clinical superiority. Following surgery the elbow is placed through a range-ofmotion to ensure there is no impingement, hardware prominence or instability. Intraoperative fluoroscopy is also recommended to ensure all hardware is extra-articular. Plating Technique Orthogonal Plating (90:90). The AO group has recommended an orthogonal (perpendicular or 90/90) plate configuration to maximize stability and allow early mobilization.5,46 Once preliminary distal articular fixation has been
Distal humerus fractures
Figure 3 A systematic approach is recommended for open reduction and internal fixation of distal humerus fractures. After exposure of the distal humerus, the articular fracture is provisionally stabilized with 2 or 3 traversing K-wires (A). Definitive fixation of the articular fracture may be conducted by a central trochlear axis screw (B) or by screws placed through plates. After stabilization of the articular segment, it must be linked to the humeral shaft. Once again, K-wires may be used to provisionally reduce the articular segment to the diaphysis (C). Definitive fixation is obtained by bi-column plating done in the orthogonal or parallel fashion (D, E).
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D.P. Goel, J.M. Pike, and G.S. Athwal
30
Figure 4 Open reduction and internal fixation of an AO/OTA type C3 fracture with a triple plating technique through an olecranon osteotomy (A). The comminuted articular segment was fixed with 2 screws placed through the axis of the trochlea (arrow). Another technique for articular fixation is to provisionally stabilize with K-wires that are exchanged for screws placed through the plates (B).
achieved, plate application follows. The key component of the posterolateral plate involves distal application without contacting the posterior articular cartilage of the capitellum. Medial column fixation involves placement of a sagittal plate along the supracondylar ridge that curves around the medial epicondyle. The proximal lengths of the plates should be variable to avoid the formation of a stress riser in the humeral diaphysis. The sequence of fixation should be tailored to each fracture configuration. Initial stabilization of large fracture fragments permits easier reduction of more comminuted segments. Parallel Plating. This plating technique also involves bicolumn fixation, however, the plates are applied in a parallel fashion rather than orthogonally. In comparison with posterolateral plating, the lateral plate is applied along the supracondylar ridge in the sagittal plain and is contoured in a “J” distally to accommodate the anterior angulation of the lateral epicondyle. The position of the plates is not directly medial or lateral, rather they are offset dorsally.47 Once plate application and provisional fixation is complete, medial and lateral proximal cortical screws are inserted to hold the plate. This is followed by the insertion of distal articular screws through the plate complying with the surgical technique of Sanchez-Sotelo et al.47 An attempt is made to place each screw through a hole within the plate, involve as many articular segments as possible and engage the condyle on the contralateral side.47 Compression with a large reduction clamp across the articular segment obviates the need for lag screws. In situations of distal bone loss, articular compression is not advised as it may shorten the mediolateral width of
the trochlea. Final compression across the supracondylar fracture site can be obtained by large reduction forceps from the contralateral articular side to the ipsilateral diaphyseal side. This is performed when an eccentric screw is placed in to the plate to allow dynamic compression. The remaining screw holes are then filled and an attempt is made to place 4 to 6 screws across the articular segment. Triple Plating. Triple plating is a combination of the above techniques. It is used in cases with severe comminution where additional fixation is required. Typically, the third plate is placed laterally to provide additional support for the lateral column. In special circumstances with severe metaphyseal bone loss, strategies, such as bridge plating, bone grafting, or supracondylar shortening ostectomy may be used.14,47 Arthroplasty. TEA may be considered in the management of DHF. TEA has been successfully used in distal humerus fractures in the elderly patients, patients with rheumatoid arthritis,48 and in cases with significant non-reconstructible articular loss, or nonunion following failed fixation.49,50 Distal humerus hemiarthroplasty is gaining favor. Unlike TEA, collateral ligament stability is essential in the setting of distal humeral hemiarthroplasty. Indications include severely comminuted articular fractures with either a low transcondylar fracture line distal to the collateral origins or simple condylar fractures that can be plated to effectively stabilize the epicondyle.51 In contrast to TEA where olecranon osteotomy is relatively contraindicated, this approach provides excellent exposure for addressing condylar fixation and access to the
Distal humerus fractures humeral medullary canal in preparation for the implant. If osteotomy is undertaken for potential fixation and stable fixation is unachievable, conversion to hemiarthroplasty is relatively straightforward. The technical strategies for this procedure have been previously documented.52
Outcomes Due to the heterogeneous nature of DHF management, the literature must be reviewed with caution. Reports must be evaluated for plate orientation, plate types, and patient characteristics as all these factors contribute to the outcomes of the specific treatment. As such, the reported outcomes following DHF fixation have been variable. Doornberg et al53 have presented the longest follow up on patients after DHF fixation. There were 30 patients followed between 12 and 30 years (average 19 years). The average age at surgery was 35 years, and fixation type varied with regards to plate type and configuration. They noted ⬎80% satisfaction overall with an average flexion/extension arc of 10 to 140 degrees and an average prosupination arc of 40 to 90. Although 40% of patients were lost to follow up, this study supports the longterm positive outcomes in young patients suffering from DHF. Similar outcomes have been reported by other retrospective series. McKee et al9 demonstrates improved functional outcome scores in patients after DHF fixation when examining the DASH and SF-36. Range of motion was similar as above with an average flexion contracture of 25 degrees (arc of 108 degrees). A study by Greiner et al54 evaluated 14 patients with distal humerus fractures treated with one particular implant (locking compression plate Synthes). At 3 months, all patients achieved bony union whereas at 10 months significant improvements in functional outcomes were noted. The average age of these patients was 55 years at the time of surgery. Overall, stable, painless functional range of motion was achieved in most patients.
Complications Ulnar Neuropathy One of the most common complications following DHF fixation involves the ulnar nerve. The incidence of ulnar neuropathy in the literature has been reported between 7-15%. Ulnar neuropathy following ORIF of DHF has been mentioned in the literature between 7% and 15%.5 The management of the ulnar nerve during surgical approaches to the distal humerus remains controversial. Ulnar nerve transposition has been recommended by some,55 but not by others.56 Throckmorton et al57 contend the most biomechanically stable construct combined with DHP position mandates ulnar nerve transposition. Gofton et al58 have supported this contention as they noted no objective ulnar nerve findings in their series of DHFs after transposition. The authors routinely expose and subcutaneously transpose the ulnar nerve in the management of distal humerus fractures.
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Contracture The elbow reacts poorly to any form of trauma and prolonged immobilization leads to stiffness. Almost all patients following fixation of distal humerus fractures develop some stiffness, yet only a small portion ultimately require secondary surgery. Functional range of motion is defined between 30 and 130 degrees of elbow motion, or an arc of 100 degrees. A range of motion less than that would be considered nonfunctional may benefit from surgical intervention. Studies have quoted approximately 15-20% of patients undergoing DHF fixation will have less than 100 degrees of motion.8,59,60 More recent literature has demonstrated a decrease in this number likely secondary to more stable forms of fixation and an overall improved understanding of these fractures and the postoperative management. The authors begin early range of motion in the setting of stable fixation. However, where fracture stability is in question, prolonged mobilization may be necessary with discussion surrounding delayed contracture release.
Heterotopic Ossification Hastings and Graham61 have defined a classification scheme for heterotopic ossification (HO) around the elbow. The extent of HO can be minimal to complete ankylosis requiring surgical excision. The rate of HO has also been variably reported between 0% and 50%.62,63 Gofton et al59 have reported a lower incidence among patients prophylactically treated with indomethacin. They found only 2 of 11 treated with indomethacin developed grade 1 HO, whereas 5 of 12 untreated patients produced heterotopic bone. A delay in treatment greater than 48 hours has been reported by Ilahi et al64 to significantly increase the development of HO in patients following DHF.
Conclusions The complex geometry of the distal humerus compounded with the increasing number of fractures in the elderly patients will continually challenge orthopaedic surgeons. Advancements have been made in imaging, surgical techniques, and fracture specific implants, however, time will determine whether patient outcomes have been improved and complications decreased. The management of distal humerus fractures should be approached in a systematic way, understanding the fracture type, its natural history, using the principles of fracture care and incorporating patient-related factors. The goals of treatment are an approach that provides adequate exposure, anatomic reduction of the joint, stable fixation to allow for early rehabilitation, and the minimization of complications.
References 1. Riseborough EJ, Radin EL: Intercondylar T fractures of the humerus in the adult. A comparison of operative and non-operative treatment in twenty-nine cases. J Bone Joint Surg Am 51:130-141, 1969 2. Aitken GK, Rorabeck CH: Distal humeral fractures in the adult. Clin Orthop Relat Res 207:191-197, 1986
32 3. Caja VL, Moroni A, Vendemia V, et al: Surgical treatment of bicondylar fractures of the distal humerus. Injury 25:433-438, 1994 4. Gabel GT, Hanson G, Bennett JB, et al: Intraarticular fractures of the distal humerus in the adult. Clin Orthop Relat Res 216:99-108, 1987 5. Helfet DL, Schmeling GJ: Bicondylar intraarticular fractures of the distal humerus in adults. Clin Orthop Relat Res 292:26-36, 1993 6. John H, Rosso R, Neff U, et al: Distal humerus fractures in patients over 75 years of age. Long-term results of osteosynthesis [in German]. Helv Chir Acta 60:219-224, 1993 7. John H, Rosso R, Neff U, et al: Operative treatment of distal humeral fractures in the elderly. J Bone Joint Surg Br 76:793-796, 1994 8. Jupiter JB, Neff U, Holzach P, et al: Intercondylar fractures of the humerus. An operative approach. J Bone Joint Surg Am 67:226-239, 1985 9. McKee MD, Wilson TL, Winston L, et al: Functional outcome following surgical treatment of intra-articular distal humeral fractures through a posterior approach. J Bone Joint Surg Am 82-A:1701-1707, 2000 10. Waddell JP, Hatch J, Richards R: Supracondylar fractures of the humerus—Results of surgical treatment. J Trauma 28:1615-1621, 1988 11. An K, Morrey BF: Biomechanics of the elbow, in Morrey BF (ed): The Elbow and Its Disorders, (ed 1). Philadelphia, PA, WB Saunders, 1993, pp 53-72 12. An KN, Kwak BM, Chao EY, et al: Determination of muscle and joint forces: A new technique to solve the indeterminate problem. J Biomech Eng 106:364-367, 1984 13. An KN, Chao EY, Morrey BF, et al: Intersegmental elbow joint load during pushup. Biomed Sci Instrum 28:69-74, 1992 14. McCarty LP, Ring D, Jupiter JB: Management of distal humerus fractures. Am J Orthop 34:430-438, 2005 15. Dunning CE, Zarzour ZD, Patterson SD, et al: Ligamentous stabilizers against posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 83-A:1823-1828, 2001 16. Armstrong AD, Dunning CE, Faber KJ, et al: Single-strand ligament reconstruction of the medial collateral ligament restores valgus elbow stability. J Shoulder Elbow Surg 11:65-71, 2002 17. Rose SH, Melton LJ III, Morrey BF, et al: Epidemiologic features of humeral fractures. Clin Orthop Relat Res 168:24-30, 1982 18. Robinson CM, Hill RM, Jacobs N, et al: Adult distal humeral metaphyseal fractures: Epidemiology and results of treatment. J Orthop Trauma 17:38-47, 2003 19. Palvanen M, Kannus P, Niemi S, et al: Secular trends in the osteoporotic fractures of the distal humerus in elderly women. Eur J Epidemiol 14:159-164, 1998 20. Jupiter JB, Mehne DK: Fractures of the distal humerus. Orthopedics 15:825-833, 1992 21. Muller ME, Nazarian N, Koch P, et al: The Comprehensive Classification of Fractures in Long Bones. Berlin, Springer-Verlag, 1990 22. Davies MB, Stanley D: A clinically applicable fracture classification for distal humeral fractures. J Shoulder Elbow Surg 15:602-608, 2006 23. Doornberg J, Lindenhovius A, Kloen P, et al: Two and three-dimensional computed tomography for the classification and management of distal humeral fractures. Evaluation of reliability and diagnostic accuracy. J Bone Joint Surg Am 88:1795-1801, 2006 24. Wilkinson JM, Stanley D: Posterior surgical approaches to the elbow: A comparative anatomic study. J Shoulder Elbow Surg 10:380-382, 2001 25. Pollock JW, Athwal GS, Steinmann SP: Surgical exposures for distal humerus fractures: A review. Clin Anat 21:757-768, 2008 26. MacAusland WA: Anklylosis of the elbow: With report of four cases treated by arthroplasty. JAMA 64:312-318, 1915 27. Hewins EA, Gofton WT, Dubberly J, et al: Plate fixation of olecranon osteotomies. J Orthop Trauma 21:58-62, 2007 28. Coles CP, Barei DP, Nork SE, et al: The olecranon osteotomy: A six-year experience in the treatment of intraarticular fractures of the distal humerus. J Orthop Trauma 20:164-171, 2006 29. Alonso-Llames M: Bilaterotricipital approach to the elbow. Its application in the osteosynthesis of supracondylar fractures of the humerus in children. Acta Orthop Scand 43:479-490, 1972
D.P. Goel, J.M. Pike, and G.S. Athwal 30. Campbell WC: Incision for exposure of the elbow joint. Am J Surg 15:65-67, 1932 31. McKee MD, Kim J, Kebaish K, et al: Functional outcome after open supracondylar fractures of the humerus. The effect of the surgical approach. J Bone Joint Surg Br 82:646-651, 2000 32. Bryan RS, Morrey BF: Extensive posterior exposure of the elbow. A triceps-sparing approach. Clin Orthop Relat Res 166:188-192, 1982 33. O’Driscoll SW: The triceps-reflecting anconeus pedicle (TRAP) approach for distal humeral fractures and nonunions. Orthop Clin North Am 31:91-101, 2000 34. Brown RF, Morgan RG: Intercondylar T-shaped fractures of the humerus. Results in ten cases treated by early mobilisation. J Bone Joint Surg Br 53:425-428, 1971 35. Eastwood W: The T-shaped fracture of the lower end of the humerus. J Bone Joint Surg Am 19:364-369, 1937 36. Jones KG: Percutaneous pin fixation of fractures of the lower end of the humerus. Clin Orthop Relat Res 50:53-69, 1967 37. Jones KG: Percutaneous pin fixation of transcondylar fractures of the humerus in children. Med Trial Tech Q 16:15-23, 1969 38. Gautier E, Perren SM, Cordey J: Effect of plate position relative to bending direction on the rigidity of a plate osteosynthesis. A theoretical analysis. Injury 31:C14-C20, 2000 (suppl 3) 39. Cole PA, Zlowodzki M, Kregor PJ: Treatment of proximal tibia fractures using the less invasive stabilization system: Surgical experience and early clinical results in 77 fractures. J Orthop Trauma 18:528-535, 2004 40. Zlowodzki M, Williamson S, Cole PA, et al: Biomechanical evaluation of the less invasive stabilization system, angled blade plate, and retrograde intramedullary nail for the internal fixation of distal femur fractures. J Orthop Trauma 18:494-502, 2004 41. Zlowodzki M, Williamson S, Zardiackas LD, et al: Biomechanical evaluation of the less invasive stabilization system and the 95-degree angled blade plate for the internal fixation of distal femur fractures in human cadaveric bones with high bone mineral density. J Trauma 60:836-840, 2006 42. Liporace FA, Kubiak EN, Jeong GK, et al: A biomechanical comparison of two volar locked plates in a dorsally unstable distal radius fracture model. J Trauma 61:668-672, 2006 43. Tejwani NC, Murthy A, Park J, et al: Fixation of extra-articular distal humerus fractures using one locking plate versus two reconstruction plates: A laboratory study. J Trauma 66:795-799, 2009 44. Schuster I, Korner J, Arzdorf M, et al: Mechanical comparison in cadaver specimens of three different 90-degree double-plate osteosyntheses for simulated C2-type distal humerus fractures with varying bone densities. J Orthop Trauma 22:113-120, 2008 45. Schemitsch EH, Tencer AF, Henley MB: Biomechanical evaluation of methods of internal fixation of the distal humerus. J Orthop Trauma 8:468-475, 1994 46. Rüedi T, Buckley RE, Moran C: AO Principles of Fracture Management, (ed 2). New York, Thieme Verlag, 2007 47. Sanchez-Sotelo J, Torchia ME, O’Driscoll SW: Complex distal humeral fractures: Internal fixation with a principle based parallel plate technique. Surgical technique. J Bone Joint Surg Am 90:31-46, 2008 48. Jost B, Adams RA, Morrey BF: Management of acute distal humeral fractures in patients with rheumatoid arthritis. A case series. J Bone Joint Surg Am 90:2197-2205, 2008 49. Cil A, Veillette CJ, Sanchez-Sotelo J, et al: Linked elbow replacement: A salvage procedure for distal humeral nonunion. J Bone Joint Surg Am 90:1939-1950, 2008 50. LaPorte DM, Murphy MS, Moore JR: Distal humerus nonunion after failed internal fixation: Reconstruction with total elbow arthroplasty. Am J Orthop 37:531-534, 2008 51. Adolfsson L, Hammer R: Elbow hemiarthroplasty for acute reconstruction of intraarticular distal humerus fractures: A preliminary report involving 4 patients. Acta Orthop 77:785-787, 2006 52. Athwal GS, Goetz TJ, Pollock JW, et al: Prosthetic replacement for distal humerus fractures. Orthop Clin North Am 39:201-212, 2008 53. Doornberg JN, van Duijn PJ, Linzel D, et al: Surgical treatment of intra-
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54.
55.
56. 57. 58.
articular fractures of the distal part of the humerus. Functional outcome after twelve to thirty years. J Bone Joint Surg Am 89:1524-1532, 2007 Greiner S, Haas NP, Bail HJ: Outcome after open reduction and angular stable internal fixation for supra-intercondylar fractures of the distal humerus: Preliminary results with the LCP distal humerus system. Arch Orthop Trauma Surg 128:723-729, 2008 Wang KC, Shih HN, Hsu KY, et al: Intercondylar fractures of the distal humerus: Routine anterior subcutaneous transposition of the ulnar nerve in a posterior operative approach. J Trauma 36:770-773, 1994 Gupta R, Khanchandani P: Intercondylar fractures of the distal humerus in adults: A critical analysis of 55 cases. Injury 33:511-515, 2002 Throckmorton TW, Zarkadas PC, Steinmann SP: Distal humerus fractures. Hand Clin 23:457-469, 2007 Gofton WT, Macdermid JC, Patterson SD, et al: Functional outcome of AO type C distal humeral fractures. J Hand Surg (Am) 28:294-308, 2003
33 59. Horne G: Supracondylar fractures of the humerus in adults. J Trauma 20:71-74, 1980 60. Jeshrani MK, Bencivenga A: The management of intra-articular fractures at the lower end of the humerus. East Afr Med J 55:393-398, 1978 61. Hastings H II, Graham TJ: The classification and treatment of heterotopic ossification about the elbow and forearm. Hand Clin 10:417-437, 1994 62. Eralp L, Kocaoglu M, Sar C, et al: Surgical treatment of distal intraarticular humeral fractures in adults. Int Orthop 25:46-50, 2001 63. Kundel K, Braun W, Wieberneit J, et al: Intraarticular distal humerus fractures. Factors affecting functional outcome. Clin Orthop Relat Res 332:200-208, 1996 64. Ilahi OA, Strausser DW, Gabel GT: Post-traumatic heterotopic ossification about the elbow. Orthopedics 21:265-268, 1998
F
ractures of the distal humerus represent challenging problems to the modern orthopaedic surgeon. Important factors to consider are the 3-dimensional geometry, limited peri-articular bone stock for internal fixation, intra-articular comminution, and the need for early mobilization. The increasing incidence of this fracture in the elderly patient in association with poor bone quality and comminution has introduced a significant challenge to the reconstructive surgeon. Historically, distal humeral fractures (DHF) were treated nonoperatively1 due to the poor results of surgery. Surgery was complicated by high infection rates and poor fixation due to rudimentary implants. Although nonoperative care may be appropriate in some situations, the modern literature strongly supports open reduction and internal fixation (ORIF) of intra-articular distal humerus fractures.2-10 The surgical goals are to obtain anatomic restoration of the articular surface and recreation of joint alignment with stable internal fixation, secure enough to allow early range of motion. This review will focus on the surgical anatomy, the mechanism of injury, classification systems, surgical exposures, and fixation techniques relevant to the operative management of distal humerus fractures.
Hand and Upper Limb Centre, St. Joseph’s Health Care, University of Western Ontario, London, Canada. Address reprint requests to George S. Athwal, MD, FRCSC, Hand and Upper Limb Centre, St. Joseph’s Health Care, University of Western Ontario, 268 Grosvenor St, London, Canada N6A 4L6. E-mail: gathwal@ uwo.ca
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1048-6666/10/$-see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1053/j.oto.2009.09.010
Anatomical Considerations A single synovial joint encompasses 3 separate articulations; ulnohumeral, proximal radioulnar, and radiocapitellar. These articulations permit elbow flexion-extension, pronation-supination, and to a minimal extent varus– valgus.11 Anatomic restoration of these multiple articulations ideally should allow loads of 0.3 to 0.5 times body weight12 or substantially more load as observed in a simple push-up.13 An understanding of the bony and ligamentous anatomy is important to avoid iatrogenic complications. The distal humerus can be thought of as a 2 column structure supporting the articular segment. The distal portion of the lateral column (capitellum) projects anteriorly approximately 35 to 40 degrees. The medial column terminates at the medial epicondyle and, in contrast, does not curve anterior. The anatomy of the trochlea is analogous to that of a spool with distal articular segment oriented at 4 to 8 degrees of valgus relative to the long axis of the humerus. Furthermore, this distal articular segment is internally rotated 3 to 4 degrees relative to the trans-epicondylar axis.14 Understanding the ligamentous anatomy is critical during exposure and plate application to avoid iatrogenic injury. The anterior bundle of the medial collateral ligament, a primary elbow stabilizer, originates on the anteroinferior aspect of the medial epicondyle and inserts onto the sublime tubercle of the ulna. The medial column and medial epicondyle, therefore, can accommodate plate placement without impinging on the MCL origin. The lateral ulnar collateral ligament, the primary lateral stabilizer, origi-
Distal humerus fractures nates and inserts on the lateral epicondyle and crista supinatoris, respectively. Identification and protection of the lateral collateral ligament origin allows visualization of the posterior aspect of the radiocapitellar joint and safe lateral plate application.15,16
Epidemiology/Mechanism of Injury Distal humerus fractures represent 2% of all fractures and approximately 30% of those involving the humerus.17 A population-based study examining all patients presenting to a single center identified a bimodal distribution with peak occurrences in young males (12-19 years) and elderly females (⬎80 years). Robinson et al18 identified an incidence of 5.7 of 100,000 in the population per year with a nearly equivalent male-to-female ratio.18 Palvanen19 retrospectively reviewed the Finnish National Hospital Discharge Register for surgically treated distal humerus fractures between 1970 and 1995. Over 25-year period, the incidence of distal humerus fractures among patients greater than 60 years of age nearly tripled (11-30%). Furthermore, the incidence in 2030 was projected to be 52 of 100, 000.19 This equates to an absolute value of 440 fractures per year within this single Finnish population.19 Motorized vehicles and extreme sports contribute to the severity and incidence of distal humerus fractures in the young. By contrast, elderly patients generally present following a low-energy ground level fall.
Fracture Classification Commonly mentioned classification systems for distal humerus fractures include the Riseborough and Radin,1 Jupiter and Mehne,20 and the AO/OTA (orthopedic trauma association)comprehensive classification.21 In 1969, Riseborough and Radin1 described intra-articular distal humerus fractures as T-shaped intercondylar, and classified them on the basis of rotation, displacement, and comminution of segments. The AO/OTA classification is an alphanumeric system dividing fractures according to degree of articular involvement. The humerus is labeled as 1 and as 3 (which identifies the distal segment of all long bones). This is further subgrouped into A (articular), B (partial articular), and C (complete articular). Each subgroup can be further classified on the basis of the fracture line and comminution where 1 represents minimal fragmentation and 3 severe comminution. The Jupiter and Mehne20 classification attempted to resolve the limitations of previous classifications through an anatomic and treatment-based system. They divided their system into intra-articular, extra-articular (intracapsular), and extracapsular fractures. The intracapsular fractures are subdivided into A-D as single column, bicolumnar, and capitellar and trochlear involvement.20 In addition to being the official classification of the OTA, it is the authors’ opinion that the AO/OTA classification is more intuitive and ubiquitous. To date, the AO/ OTA classification has demonstrated the highest inter- and
25 intraobserver reliability while also being the most inclusive of fracture types.22
Imaging Standard anteroposterior and lateral radiographs are sufficient for classification and preoperative planning. Computed tomography with 3-dimensional reconstructions, although not required for all cases, can improve fracture identification and classification. Doornberg et al23 examined the utility of 3-dimensional computed tomography in the evaluation of distal humerus fractures. They found improved inter- and intraobserver reliability within the Jupiter/Mehne20 and AO/OTA classifications. Interestingly, 3-dimensional images improved the reliability, but not the accuracy, of fracture identification and classification.
Surgical Exposures The selection of a surgical approach for the management of distal humerus fractures is dependent on several factors. These include the surgeon’s experience and preferences, fracture pattern, degree of articular involvement, associated soft tissue injury, rehabilitation protocols, and whether intraoperative conversion to arthroplasty is contemplated. The ideal approach for each individual fracture should provide adequate visualization to allow anatomic reduction and the application of internal fixation to maintain elbow stability with minimization of soft tissue and bone disruption to permit early motion. Several surgical approaches will be discussed with their strengths and limitations highlighted. Approaches to the distal humerus can be categorized into olecranon osteotomies, triceps sparing (triceps-on), triceps splitting, and triceps reflecting (triceps-off). Visualization of the distal humerus articular segment varies with each approach. The triceps splitting, triceps reflecting, and olecranon osteotomy expose 35%, 46%, and 57% of the distal articular segment, respectively.24 A thorough review of elbow anatomy and detailed approaches has been previously documented.25 However, for this review we will highlight some important issues surrounding each approach.
Olecranon Osteotomy With several modifications of MacAusland’s26 original description, the olecranon osteotomy is the authors’ most commonly used approach for management of complex intra-articular DHF, as it affords the best visualization of the articular segment. The outcomes after this approach, however, can be complicated by malunion, nonunion, and hardware concerns.24 Hewins et al27 describe the steps required to minimize postoperative complications after the creation of an olecranon osteotomy. These include precontouring and fixation of a 3.5 mm reconstruction plate to the olecranon with screws directed ulnarly to avoid the proximal radio-ulnar joint, identification of the bare spot through medial and min-
D.P. Goel, J.M. Pike, and G.S. Athwal
26 imal lateral dissection and maintenance of subchondral bone before completion of osteotomy.27 Triceps weakness after olecranon osteotomy when compared with the contralateral limb has been shown,27 however, when compared with a triceps splitting approach, no discernible weakness was identified.28 Coles et al28 reported their 6 year follow-up results of patients undergoing an olecranon osteotomy. In their retrospective review, 46 patients were surgically treated with intramedullary screw supplemented with dorsal ulnar wiring and 24 patients with plate fixation. They reported no nonunions, 1 delayed union, 2 hardware revisions, and 13 hardware removals. Most hardware removals (11 patients) were associated with a secondary procedure (capsular release for stiffness).28
Triceps Sparing (Triceps-On) or Bilaterotricipital Approach Alonso-Llames29 described the bilaterotricipital approach for the treatment of pediatric supracondylar fractures. This approach avoids any disruption of the extensor mechanism insertion on the olecranon using surgical windows along the medial and lateral sides of the triceps (Fig. 1). The main advantages of this approach are the avoidance of an osteotomy and maintenance of triceps integrity to allow early active motion. An additional advantage of this approach is that it allows easy intraoperative conversion to a total elbow arthroplasty (TEA) if stable ORIF is deemed unlikely. Distal extension of the lateral window into the Boyd approach assists with intra-articular exposure. The main disadvantage of this approach is the limited visualization of the articular segment.
This approach is best reserved for extra-articular fractures or simple intra-articular fractures with minimal comminution (Fig. 2).
Triceps Splitting Campbell30 described the triceps splitting approach for exposure of the distal humerus in 1932. It involves a distal midline triceps tendon split with equal portions of the triceps tendon and its insertion on the olecranon reflected medially and laterally. Wilkinson and Stanley24 in their comparative study of posterior elbow approaches reported that only 35% of the distal humerus articular segment could be visualized with the triceps split, which does limit its usefulness. McKee et al31 compared the olecranon osteotomy to the triceps split for DHF and found no difference in functional outcomes at follow-up.
Bryan-Morrey Approach The Bryan-Morrey32 approach is used commonly for TEA and can also be used for fixation of distal humerus fractures. This exposure permits good exposure of the distal humerus by reflecting the triceps tendon and its insertion from medial to lateral. The reflected triceps tendon maintains its attachment to the ulnar periosteum and anconeus thereby preserving its length. The main advantage of this approach is that it avoids the complications associated with an olecranon osteotomy. Reported disadvantages include complications, such as failure of the extensor mechanism repair and extensor weakness.
Figure 1 The bilaterotricipital approach (triceps-on) described by Alonso-Llames29 allows bi-column plating of the distal humerus. The main advantage of this approach is that it does not disrupt the extensor mechanism. The main disadvantage is the limited visualization of the articular surface. Lateral (A) and medial (B) plates applied through the bilaterotricipital approach.
Distal humerus fractures
27
Figure 2 The bilaterotricipital approach may be used for fixation of trans-condylar and simple intra-articular fractures. Radiographs (A, B) of an AO/OTA type C1 fracture fixated with precontoured parallel plates (C, D).
Triceps Reflecting Anconeus Pedicle The triceps reflecting anconeus pedicle approach, as its name implies, reflects the anconeus and entire triceps insertion proximally without violating the olecranon.33 This exposure preserves the innervation of the anconeus muscle, therefore, maintaining its role as a dynamic varus and posterolateral stabilizer.33 The main advantage of this approach is that it avoids the complications inherent with the olecranon osteotomy. The main disadvantage is the possibility of triceps
weakness or repair dehiscence. In the authors’ practice, this approach is used rarely.
Management Non-operative Non-operative care in the management of distal humerus fractures was recommended as 1969 by Riseborough and Radin.1 Brown and Morgan,34 in 1971, treated 10 intra-artic-
28 ular distal humerus fractures nonoperatively with early mobilization and noted an arc of motion of 100 degrees in most of their patients. This “bag of bones” treatment has been posed as a reasonable treatment option in select patients.35 Non-surgical care of distal humerus fractures may be considered in those patients medically unfit for surgery, with low functional demands or neurological impairment. Although nonoperative care may be recommended in certain special situations, most patients have superior functional outcomes after operative treatment.2-10
Operative Management To appreciate current trends in distal humerus fracture management, an understanding of implant biomechanics is required, including plate configuration and fixation type. Although percutaneous Kirschner wire fixation has been regarded as the treatment of choice for pediatric supracondylar fractures,36,37 it is not recommended for distal humerus fractures in the adult population. Plate fixation with screws is the most acceptable form of treatment in adults, however, several factors are important when considering plate configuration. These factors include the type of fracture, the quality of the bone, the modulus of the implant and the location of the implant on the bone. The modulus of elasticity of the implant has been mentioned as being less important than the actual configuration of the plating system.38 Several different plating configurations exist, as plates may be applied orthogonally (90/90), in a parallel fashion or both (triple plating). Controversy exists on which plating configuration is ideal. To date, no one type of plating configuration has demonstrated clinical superiority in a comparative study. Plate Types Several different plate types have been used in the past, presently 3 general options exist, 3.5 mm standard straight plates that are intraoperatively contoured, fracture specific precontoured plates, and precontoured locking plates. Thinner plates (one-third tubular) or screw-only fixation are not recommended. The use of locking plates in other fractures, such as fractures of the proximal tibia,39 distal femur40,41 and unstable distal radius fractures,42 has obviated the need for bicolumnar fixation. In distal humerus fractures, however, this does not hold true. Tejwani et al43 evaluated single column locked plate fixation compared with double column reconstruction plates and found the latter to be more resistant to loads. Schuster et al44 evaluated a similar construct with 3 different plate configurations [reconstruction plate, locking compression plate, Synthes, GmbH, Solothurn, Switzerland] and the anatomically precontoured distal humerus plate (DHP, Synthes GmbH, Solothurn, Switzerland). They observed no difference in stiffness testing in extension or flexion. However, as bone mineral density decreased, the number of hardware failures increased in the reconstruction plate, whereas none were observed in the DHP. Although not stated, this study may suggest the value of precontoured locking constructs in the management of osteoporotic fractures.44 The lack of specific recommendations regarding optimal plate type and configuration is inherent in the literature.
D.P. Goel, J.M. Pike, and G.S. Athwal However, adherence to a principle-based approach with emphasis on articular reduction and double column rigid fixation to the metaphyseal segment is highly recommended.45 Fixation Approach. A principle-based approach to the management of distal humerus fractures is recommended. This form of treatment relies on 2 basic principles: articular reconstruction followed by column reconstruction. Articulator Reconstruction. The principles of peri-articular fracture fixation include restoration of the articular segment, column realignment and rigid fixation to allow for early mobilization. Preliminary fixation of the articular segment may be performed with Kirschner wires (K-wires) (Fig. 3). Several K-wires may be required for temporary fixation, therefore, they should be placed strategically taking in to consideration final plate and screw position. The main fragments of the articular segment can be fixated by 2 methods. The first method involves the placement of a central spool screw down the axis of the trochlea to fixate the 2 main fragments. Another method involves provisional fixation of the articular segment with K-wires followed by definitive fixation with screws placed through medial and lateral plates applied in a parallel manner (Fig. 4). In cases with articular comminution, the comminuted minor fragments can be fixated to the major fragments with threaded K-wires, headless compression screws or bioabsorbable pins. Coronal shear fractures of the capitellum, trochlea, or both may occur in association with distal humerus fractures. These coronal shear fragments can be visualized by internally rotating each condyle. This allows fixation of the coronal shear fracture and than subsequent fixation of the primary sagittal plane articular fracture. In situations where articular segments are absent, a principle-based approach is once again important. Restoration of joint range of motion is primarily dependent on the medial and lateral ridges of the trochlea. Therefore, loss of the midportion of the trochlea or the posterior articular surface, although important, is not entirely necessary for stability. Column Reconstruction Once the articular segment has been provisionally fixed, it must be rigidly linked to the humeral diaphysis. Provisional fixation of the articular segment to the diaphysis may be performed with K-wires inserted retrograde from distal to proximal. As mentioned, several different plating techniques exist, including orthogonal plating (90:90), parallel plating, and triple plating. All 3 techniques have been supported clinically and none have demonstrated clinical superiority. Following surgery the elbow is placed through a range-ofmotion to ensure there is no impingement, hardware prominence or instability. Intraoperative fluoroscopy is also recommended to ensure all hardware is extra-articular. Plating Technique Orthogonal Plating (90:90). The AO group has recommended an orthogonal (perpendicular or 90/90) plate configuration to maximize stability and allow early mobilization.5,46 Once preliminary distal articular fixation has been
Distal humerus fractures
Figure 3 A systematic approach is recommended for open reduction and internal fixation of distal humerus fractures. After exposure of the distal humerus, the articular fracture is provisionally stabilized with 2 or 3 traversing K-wires (A). Definitive fixation of the articular fracture may be conducted by a central trochlear axis screw (B) or by screws placed through plates. After stabilization of the articular segment, it must be linked to the humeral shaft. Once again, K-wires may be used to provisionally reduce the articular segment to the diaphysis (C). Definitive fixation is obtained by bi-column plating done in the orthogonal or parallel fashion (D, E).
29
D.P. Goel, J.M. Pike, and G.S. Athwal
30
Figure 4 Open reduction and internal fixation of an AO/OTA type C3 fracture with a triple plating technique through an olecranon osteotomy (A). The comminuted articular segment was fixed with 2 screws placed through the axis of the trochlea (arrow). Another technique for articular fixation is to provisionally stabilize with K-wires that are exchanged for screws placed through the plates (B).
achieved, plate application follows. The key component of the posterolateral plate involves distal application without contacting the posterior articular cartilage of the capitellum. Medial column fixation involves placement of a sagittal plate along the supracondylar ridge that curves around the medial epicondyle. The proximal lengths of the plates should be variable to avoid the formation of a stress riser in the humeral diaphysis. The sequence of fixation should be tailored to each fracture configuration. Initial stabilization of large fracture fragments permits easier reduction of more comminuted segments. Parallel Plating. This plating technique also involves bicolumn fixation, however, the plates are applied in a parallel fashion rather than orthogonally. In comparison with posterolateral plating, the lateral plate is applied along the supracondylar ridge in the sagittal plain and is contoured in a “J” distally to accommodate the anterior angulation of the lateral epicondyle. The position of the plates is not directly medial or lateral, rather they are offset dorsally.47 Once plate application and provisional fixation is complete, medial and lateral proximal cortical screws are inserted to hold the plate. This is followed by the insertion of distal articular screws through the plate complying with the surgical technique of Sanchez-Sotelo et al.47 An attempt is made to place each screw through a hole within the plate, involve as many articular segments as possible and engage the condyle on the contralateral side.47 Compression with a large reduction clamp across the articular segment obviates the need for lag screws. In situations of distal bone loss, articular compression is not advised as it may shorten the mediolateral width of
the trochlea. Final compression across the supracondylar fracture site can be obtained by large reduction forceps from the contralateral articular side to the ipsilateral diaphyseal side. This is performed when an eccentric screw is placed in to the plate to allow dynamic compression. The remaining screw holes are then filled and an attempt is made to place 4 to 6 screws across the articular segment. Triple Plating. Triple plating is a combination of the above techniques. It is used in cases with severe comminution where additional fixation is required. Typically, the third plate is placed laterally to provide additional support for the lateral column. In special circumstances with severe metaphyseal bone loss, strategies, such as bridge plating, bone grafting, or supracondylar shortening ostectomy may be used.14,47 Arthroplasty. TEA may be considered in the management of DHF. TEA has been successfully used in distal humerus fractures in the elderly patients, patients with rheumatoid arthritis,48 and in cases with significant non-reconstructible articular loss, or nonunion following failed fixation.49,50 Distal humerus hemiarthroplasty is gaining favor. Unlike TEA, collateral ligament stability is essential in the setting of distal humeral hemiarthroplasty. Indications include severely comminuted articular fractures with either a low transcondylar fracture line distal to the collateral origins or simple condylar fractures that can be plated to effectively stabilize the epicondyle.51 In contrast to TEA where olecranon osteotomy is relatively contraindicated, this approach provides excellent exposure for addressing condylar fixation and access to the
Distal humerus fractures humeral medullary canal in preparation for the implant. If osteotomy is undertaken for potential fixation and stable fixation is unachievable, conversion to hemiarthroplasty is relatively straightforward. The technical strategies for this procedure have been previously documented.52
Outcomes Due to the heterogeneous nature of DHF management, the literature must be reviewed with caution. Reports must be evaluated for plate orientation, plate types, and patient characteristics as all these factors contribute to the outcomes of the specific treatment. As such, the reported outcomes following DHF fixation have been variable. Doornberg et al53 have presented the longest follow up on patients after DHF fixation. There were 30 patients followed between 12 and 30 years (average 19 years). The average age at surgery was 35 years, and fixation type varied with regards to plate type and configuration. They noted ⬎80% satisfaction overall with an average flexion/extension arc of 10 to 140 degrees and an average prosupination arc of 40 to 90. Although 40% of patients were lost to follow up, this study supports the longterm positive outcomes in young patients suffering from DHF. Similar outcomes have been reported by other retrospective series. McKee et al9 demonstrates improved functional outcome scores in patients after DHF fixation when examining the DASH and SF-36. Range of motion was similar as above with an average flexion contracture of 25 degrees (arc of 108 degrees). A study by Greiner et al54 evaluated 14 patients with distal humerus fractures treated with one particular implant (locking compression plate Synthes). At 3 months, all patients achieved bony union whereas at 10 months significant improvements in functional outcomes were noted. The average age of these patients was 55 years at the time of surgery. Overall, stable, painless functional range of motion was achieved in most patients.
Complications Ulnar Neuropathy One of the most common complications following DHF fixation involves the ulnar nerve. The incidence of ulnar neuropathy in the literature has been reported between 7-15%. Ulnar neuropathy following ORIF of DHF has been mentioned in the literature between 7% and 15%.5 The management of the ulnar nerve during surgical approaches to the distal humerus remains controversial. Ulnar nerve transposition has been recommended by some,55 but not by others.56 Throckmorton et al57 contend the most biomechanically stable construct combined with DHP position mandates ulnar nerve transposition. Gofton et al58 have supported this contention as they noted no objective ulnar nerve findings in their series of DHFs after transposition. The authors routinely expose and subcutaneously transpose the ulnar nerve in the management of distal humerus fractures.
31
Contracture The elbow reacts poorly to any form of trauma and prolonged immobilization leads to stiffness. Almost all patients following fixation of distal humerus fractures develop some stiffness, yet only a small portion ultimately require secondary surgery. Functional range of motion is defined between 30 and 130 degrees of elbow motion, or an arc of 100 degrees. A range of motion less than that would be considered nonfunctional may benefit from surgical intervention. Studies have quoted approximately 15-20% of patients undergoing DHF fixation will have less than 100 degrees of motion.8,59,60 More recent literature has demonstrated a decrease in this number likely secondary to more stable forms of fixation and an overall improved understanding of these fractures and the postoperative management. The authors begin early range of motion in the setting of stable fixation. However, where fracture stability is in question, prolonged mobilization may be necessary with discussion surrounding delayed contracture release.
Heterotopic Ossification Hastings and Graham61 have defined a classification scheme for heterotopic ossification (HO) around the elbow. The extent of HO can be minimal to complete ankylosis requiring surgical excision. The rate of HO has also been variably reported between 0% and 50%.62,63 Gofton et al59 have reported a lower incidence among patients prophylactically treated with indomethacin. They found only 2 of 11 treated with indomethacin developed grade 1 HO, whereas 5 of 12 untreated patients produced heterotopic bone. A delay in treatment greater than 48 hours has been reported by Ilahi et al64 to significantly increase the development of HO in patients following DHF.
Conclusions The complex geometry of the distal humerus compounded with the increasing number of fractures in the elderly patients will continually challenge orthopaedic surgeons. Advancements have been made in imaging, surgical techniques, and fracture specific implants, however, time will determine whether patient outcomes have been improved and complications decreased. The management of distal humerus fractures should be approached in a systematic way, understanding the fracture type, its natural history, using the principles of fracture care and incorporating patient-related factors. The goals of treatment are an approach that provides adequate exposure, anatomic reduction of the joint, stable fixation to allow for early rehabilitation, and the minimization of complications.
References 1. Riseborough EJ, Radin EL: Intercondylar T fractures of the humerus in the adult. A comparison of operative and non-operative treatment in twenty-nine cases. J Bone Joint Surg Am 51:130-141, 1969 2. Aitken GK, Rorabeck CH: Distal humeral fractures in the adult. Clin Orthop Relat Res 207:191-197, 1986
32 3. Caja VL, Moroni A, Vendemia V, et al: Surgical treatment of bicondylar fractures of the distal humerus. Injury 25:433-438, 1994 4. Gabel GT, Hanson G, Bennett JB, et al: Intraarticular fractures of the distal humerus in the adult. Clin Orthop Relat Res 216:99-108, 1987 5. Helfet DL, Schmeling GJ: Bicondylar intraarticular fractures of the distal humerus in adults. Clin Orthop Relat Res 292:26-36, 1993 6. John H, Rosso R, Neff U, et al: Distal humerus fractures in patients over 75 years of age. Long-term results of osteosynthesis [in German]. Helv Chir Acta 60:219-224, 1993 7. John H, Rosso R, Neff U, et al: Operative treatment of distal humeral fractures in the elderly. J Bone Joint Surg Br 76:793-796, 1994 8. Jupiter JB, Neff U, Holzach P, et al: Intercondylar fractures of the humerus. An operative approach. J Bone Joint Surg Am 67:226-239, 1985 9. McKee MD, Wilson TL, Winston L, et al: Functional outcome following surgical treatment of intra-articular distal humeral fractures through a posterior approach. J Bone Joint Surg Am 82-A:1701-1707, 2000 10. Waddell JP, Hatch J, Richards R: Supracondylar fractures of the humerus—Results of surgical treatment. J Trauma 28:1615-1621, 1988 11. An K, Morrey BF: Biomechanics of the elbow, in Morrey BF (ed): The Elbow and Its Disorders, (ed 1). Philadelphia, PA, WB Saunders, 1993, pp 53-72 12. An KN, Kwak BM, Chao EY, et al: Determination of muscle and joint forces: A new technique to solve the indeterminate problem. J Biomech Eng 106:364-367, 1984 13. An KN, Chao EY, Morrey BF, et al: Intersegmental elbow joint load during pushup. Biomed Sci Instrum 28:69-74, 1992 14. McCarty LP, Ring D, Jupiter JB: Management of distal humerus fractures. Am J Orthop 34:430-438, 2005 15. Dunning CE, Zarzour ZD, Patterson SD, et al: Ligamentous stabilizers against posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 83-A:1823-1828, 2001 16. Armstrong AD, Dunning CE, Faber KJ, et al: Single-strand ligament reconstruction of the medial collateral ligament restores valgus elbow stability. J Shoulder Elbow Surg 11:65-71, 2002 17. Rose SH, Melton LJ III, Morrey BF, et al: Epidemiologic features of humeral fractures. Clin Orthop Relat Res 168:24-30, 1982 18. Robinson CM, Hill RM, Jacobs N, et al: Adult distal humeral metaphyseal fractures: Epidemiology and results of treatment. J Orthop Trauma 17:38-47, 2003 19. Palvanen M, Kannus P, Niemi S, et al: Secular trends in the osteoporotic fractures of the distal humerus in elderly women. Eur J Epidemiol 14:159-164, 1998 20. Jupiter JB, Mehne DK: Fractures of the distal humerus. Orthopedics 15:825-833, 1992 21. Muller ME, Nazarian N, Koch P, et al: The Comprehensive Classification of Fractures in Long Bones. Berlin, Springer-Verlag, 1990 22. Davies MB, Stanley D: A clinically applicable fracture classification for distal humeral fractures. J Shoulder Elbow Surg 15:602-608, 2006 23. Doornberg J, Lindenhovius A, Kloen P, et al: Two and three-dimensional computed tomography for the classification and management of distal humeral fractures. Evaluation of reliability and diagnostic accuracy. J Bone Joint Surg Am 88:1795-1801, 2006 24. Wilkinson JM, Stanley D: Posterior surgical approaches to the elbow: A comparative anatomic study. J Shoulder Elbow Surg 10:380-382, 2001 25. Pollock JW, Athwal GS, Steinmann SP: Surgical exposures for distal humerus fractures: A review. Clin Anat 21:757-768, 2008 26. MacAusland WA: Anklylosis of the elbow: With report of four cases treated by arthroplasty. JAMA 64:312-318, 1915 27. Hewins EA, Gofton WT, Dubberly J, et al: Plate fixation of olecranon osteotomies. J Orthop Trauma 21:58-62, 2007 28. Coles CP, Barei DP, Nork SE, et al: The olecranon osteotomy: A six-year experience in the treatment of intraarticular fractures of the distal humerus. J Orthop Trauma 20:164-171, 2006 29. Alonso-Llames M: Bilaterotricipital approach to the elbow. Its application in the osteosynthesis of supracondylar fractures of the humerus in children. Acta Orthop Scand 43:479-490, 1972
D.P. Goel, J.M. Pike, and G.S. Athwal 30. Campbell WC: Incision for exposure of the elbow joint. Am J Surg 15:65-67, 1932 31. McKee MD, Kim J, Kebaish K, et al: Functional outcome after open supracondylar fractures of the humerus. The effect of the surgical approach. J Bone Joint Surg Br 82:646-651, 2000 32. Bryan RS, Morrey BF: Extensive posterior exposure of the elbow. A triceps-sparing approach. Clin Orthop Relat Res 166:188-192, 1982 33. O’Driscoll SW: The triceps-reflecting anconeus pedicle (TRAP) approach for distal humeral fractures and nonunions. Orthop Clin North Am 31:91-101, 2000 34. Brown RF, Morgan RG: Intercondylar T-shaped fractures of the humerus. Results in ten cases treated by early mobilisation. J Bone Joint Surg Br 53:425-428, 1971 35. Eastwood W: The T-shaped fracture of the lower end of the humerus. J Bone Joint Surg Am 19:364-369, 1937 36. Jones KG: Percutaneous pin fixation of fractures of the lower end of the humerus. Clin Orthop Relat Res 50:53-69, 1967 37. Jones KG: Percutaneous pin fixation of transcondylar fractures of the humerus in children. Med Trial Tech Q 16:15-23, 1969 38. Gautier E, Perren SM, Cordey J: Effect of plate position relative to bending direction on the rigidity of a plate osteosynthesis. A theoretical analysis. Injury 31:C14-C20, 2000 (suppl 3) 39. Cole PA, Zlowodzki M, Kregor PJ: Treatment of proximal tibia fractures using the less invasive stabilization system: Surgical experience and early clinical results in 77 fractures. J Orthop Trauma 18:528-535, 2004 40. Zlowodzki M, Williamson S, Cole PA, et al: Biomechanical evaluation of the less invasive stabilization system, angled blade plate, and retrograde intramedullary nail for the internal fixation of distal femur fractures. J Orthop Trauma 18:494-502, 2004 41. Zlowodzki M, Williamson S, Zardiackas LD, et al: Biomechanical evaluation of the less invasive stabilization system and the 95-degree angled blade plate for the internal fixation of distal femur fractures in human cadaveric bones with high bone mineral density. J Trauma 60:836-840, 2006 42. Liporace FA, Kubiak EN, Jeong GK, et al: A biomechanical comparison of two volar locked plates in a dorsally unstable distal radius fracture model. J Trauma 61:668-672, 2006 43. Tejwani NC, Murthy A, Park J, et al: Fixation of extra-articular distal humerus fractures using one locking plate versus two reconstruction plates: A laboratory study. J Trauma 66:795-799, 2009 44. Schuster I, Korner J, Arzdorf M, et al: Mechanical comparison in cadaver specimens of three different 90-degree double-plate osteosyntheses for simulated C2-type distal humerus fractures with varying bone densities. J Orthop Trauma 22:113-120, 2008 45. Schemitsch EH, Tencer AF, Henley MB: Biomechanical evaluation of methods of internal fixation of the distal humerus. J Orthop Trauma 8:468-475, 1994 46. Rüedi T, Buckley RE, Moran C: AO Principles of Fracture Management, (ed 2). New York, Thieme Verlag, 2007 47. Sanchez-Sotelo J, Torchia ME, O’Driscoll SW: Complex distal humeral fractures: Internal fixation with a principle based parallel plate technique. Surgical technique. J Bone Joint Surg Am 90:31-46, 2008 48. Jost B, Adams RA, Morrey BF: Management of acute distal humeral fractures in patients with rheumatoid arthritis. A case series. J Bone Joint Surg Am 90:2197-2205, 2008 49. Cil A, Veillette CJ, Sanchez-Sotelo J, et al: Linked elbow replacement: A salvage procedure for distal humeral nonunion. J Bone Joint Surg Am 90:1939-1950, 2008 50. LaPorte DM, Murphy MS, Moore JR: Distal humerus nonunion after failed internal fixation: Reconstruction with total elbow arthroplasty. Am J Orthop 37:531-534, 2008 51. Adolfsson L, Hammer R: Elbow hemiarthroplasty for acute reconstruction of intraarticular distal humerus fractures: A preliminary report involving 4 patients. Acta Orthop 77:785-787, 2006 52. Athwal GS, Goetz TJ, Pollock JW, et al: Prosthetic replacement for distal humerus fractures. Orthop Clin North Am 39:201-212, 2008 53. Doornberg JN, van Duijn PJ, Linzel D, et al: Surgical treatment of intra-
Distal humerus fractures
54.
55.
56. 57. 58.
articular fractures of the distal part of the humerus. Functional outcome after twelve to thirty years. J Bone Joint Surg Am 89:1524-1532, 2007 Greiner S, Haas NP, Bail HJ: Outcome after open reduction and angular stable internal fixation for supra-intercondylar fractures of the distal humerus: Preliminary results with the LCP distal humerus system. Arch Orthop Trauma Surg 128:723-729, 2008 Wang KC, Shih HN, Hsu KY, et al: Intercondylar fractures of the distal humerus: Routine anterior subcutaneous transposition of the ulnar nerve in a posterior operative approach. J Trauma 36:770-773, 1994 Gupta R, Khanchandani P: Intercondylar fractures of the distal humerus in adults: A critical analysis of 55 cases. Injury 33:511-515, 2002 Throckmorton TW, Zarkadas PC, Steinmann SP: Distal humerus fractures. Hand Clin 23:457-469, 2007 Gofton WT, Macdermid JC, Patterson SD, et al: Functional outcome of AO type C distal humeral fractures. J Hand Surg (Am) 28:294-308, 2003
33 59. Horne G: Supracondylar fractures of the humerus in adults. J Trauma 20:71-74, 1980 60. Jeshrani MK, Bencivenga A: The management of intra-articular fractures at the lower end of the humerus. East Afr Med J 55:393-398, 1978 61. Hastings H II, Graham TJ: The classification and treatment of heterotopic ossification about the elbow and forearm. Hand Clin 10:417-437, 1994 62. Eralp L, Kocaoglu M, Sar C, et al: Surgical treatment of distal intraarticular humeral fractures in adults. Int Orthop 25:46-50, 2001 63. Kundel K, Braun W, Wieberneit J, et al: Intraarticular distal humerus fractures. Factors affecting functional outcome. Clin Orthop Relat Res 332:200-208, 1996 64. Ilahi OA, Strausser DW, Gabel GT: Post-traumatic heterotopic ossification about the elbow. Orthopedics 21:265-268, 1998