Many options exist for reconstruction of the posterior elbow/olecranon area following wound formation. Careful early wound management is crucial to ensure successful outcomes following reconstruction. Local and regional options are preferred methods for soft tissue coverage in this region. Common flap options include the reversed lateral arm flap, the radial forearm flap, posterior interosseous artery flap, brachioradialis muscle flap, flexor carpi ulnaris flap, and the latissimus flap. The advantages and disadvantages of these flap options are discussed in this review.
Key points
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Aggressive wound preparation is crucial to ensure success with reconstructive techniques.
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Early considerations for protection of the ulnar nerve may prevent injury with repeat surgery.
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A Doppler Allen examination before radial forearm flap harvest will help minimize donor site morbidity following flap harvest.
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The reversed lateral arm flap provides versatile and reliable soft tissue coverage for the posterior elbow region.
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Local perforator-based propeller flap options can be successfully used with limited donor site morbidity.
Introduction
Advances in upper extremity soft tissue reconstruction have been paralleled by the precise description and characterization of soft tissue vascular anatomy. The number and variety of wound management and coverage options have increased, allowing surgeons to tailor their treatment plans to the requirements of each clinical scenario.
Reconstructive Principles
The soft tissue envelope of the posterior elbow is a common site of wound complications because of a confluence of issues. Its location and prominence make it an area at risk in high-energy trauma. Surgical treatment of complex elbow fractures commonly uses the posterior approach for extensile access to the medial and lateral aspects of the joint, leaving the olecranon at risk for wound dehiscence and potential hardware exposure. Infectious or inflammatory olecranon bursitis also risk tissue breakdown in this difficult location. Finally, the anatomic location of this tissue over the apex of a joint capable of more than 130° of flexion exposes these wounds to tension and motion, further inhibiting healing and risking dehiscence. The reasons that put this location at risk of chronic wound development also make the prospect of success with local wound care unlikely. Local debridement and dressing changes may commonly succeed in decreasing the size of the wound but may fail to achieve final and stable closure.
Failure of local wound care is followed by consideration given to local skin flap advancement or rotation flaps. In assessing areas adjacent to a wound, mobility and pliability are often related to the chronicity of the wound. Long-standing wounds have varying degrees of inflammation and loss of tissue elasticity. These conditions make local tissue rearrangement and local flap options less feasible. Attempts at local skin advancement are performed with postoperative extension splinting to minimize tissue tension. These efforts are limited by the concern for creation or exacerbation of elbow stiffness with prolonged immobilization. If these conservative measures fail, more involved flap coverage is considered.
With pedicled transfer options, understanding the type and extent of previous surgeries/injuries may limit available flap options. A prior lateral approach to a humerus fracture, for example, will compromise vascular supply to the lateral arm flap and eliminate this option for reconstruction. Similarly, radial artery damage can compromise the vascularity for a pedicled radial forearm flap. The need for evaluation of the integrity of the superficial arch of the hand is heightened in the setting of concomitant more distal injury to the hand if radial forearm flap harvest is being considered.
Preoperative Considerations
Preoperative considerations before olecranon coverage are many and are related to the complexity and extent of the wound.
The status of the underlying bone will alter surgical plans significantly. In the setting of chronic atraumatic olecranon wounds, superficial osteomyelitis is anticipated and saucerization of the exposed and contaminated bone is required before flap elevation and closure. Posterior elbow wounds encountered after fracture management are more complex. Consideration must be given to removal of exposed hardware and debridement of exposed fractures. This can be considerably complicated if the fracture is not yet healed and current fixation is considered ideal or irreplaceable. In these settings, contaminated hardware may be preserved after debridement and irrigation in pursuit of delaying hardware removal until fracture union is achieved. In these difficult settings, the risk of loss of fracture fixation must be weighed against the risks of temporary preservation of contaminated implants.
The complexity and intra-articular involvement of underlying fractures may make the anticipation of stiffness a near certainty, and should alert the reconstructive surgeon to the possibility of future surgeries in the same field. Elbow capsulectomy, for example, may be significantly easier if performed through a matured fasciocutaneous flap than a less pliable and mobile muscle flap.
The ulnar nerve should always be given consideration in preoperative planning for posterior elbow coverage. If the nerve has not been previously transposed, the surgeon should consider transposition if the wound debridement or flap elevation will expose the nerve and leave the cubital tunnel at risk for scarring or compression. If a future capsulectomy requiring medial column dissection is anticipated, ulnar nerve transposition may also be helpful in avoiding future nerve injury.
The vascular status of the various flaps described herein is not routinely assessed with preoperative studies with the exception of the radial forearm flap. If the radial forearm flap is planned as the primary or backup procedure, a careful Allen test is performed to ensure that the perfusion to the hand would not be compromised with absence of the radial artery inflow. The authors perform this in the office with the use of a surface Doppler probe. This does not provide quantitative measurements and must be interpreted critically to determine if radial forearm flap harvest is safe. The authors require that the quality and intensity of the Doppler signal audible on the volar pads of the digits (with particular attention given to the thumb) remain unchanged after manual compression of the radial artery at the wrist.
Finally, consideration should be given to the size and location of the wound anticipated after debridement with the elbow in full flexion. A fibrotic infected wound assessed before debridement with the elbow extended may greatly underestimate the size and location of tissue required.
Flap Options and Techniques
Various muscle, fasciocutaneous, and cutaneous flaps have been described as coverage options for posterior elbow wounds. The most common flaps used for this area include the reversed lateral arm, latissimus dorsi, brachioradialis, flexor carpi ulnaris, radial forearm, and local perforator-based cutaneous flaps. These flap types are discussed and advantages and limitations of each type of flap are highlighted.
Lateral arm flap
Anatomy
The lateral arm flap is a versatile flap used for pedicled transfer to the posterior elbow region. The vascular anatomy permits this flap to be used as an antegrade or retrograde (“reversed”) pedicled flap. This septofasciocutaneous flap is based on the posterior branch of the radial collateral artery (PRCA), which arises from the profunda brachial artery. This vessel courses along the periosteum of the lateral column of the humerus and is elevated with the lateral intermuscular septum and overlying skin. The cutaneous vessels originating from the PRCA are focused in the distal lateral arm, where 2 to 5 branches supply the lateral arm skin. An antegrade flap will provide perfusion distal to the lateral epicondyle, permitting the “extended lateral arm flap” harvest to include the proximal dorsal forearm skin ( Fig. 1 ).
The PRCA communicates with the radial recurrent artery of the proximal forearm as well as with the recurrent branch of the posterior interosseous system. These interconnections permit retrograde harvest of the same angiosome. This retrograde configuration is the most commonly used flap design for coverage of olecranon wounds.
Technique
Retrograde lateral arm flaps are designed by drawing a line between the deltoid insertion and the lateral epicondyle, indicating the location of the lateral intermuscular septum. A longitudinal ellipse is drawn with its proximal apex at the spiral groove. Distally the surgeon has 2 choices. The ellipse may be completed at the level of the lateral epicondyle, creating an island flap based on the septum and wide subcutaneous leash of vessels coursing proximally. If this option is selected, the flap may be tunneled subcutaneously into the wound ( Figs. 2 and 3 ). Alternatively, the surgeon may choose to incompletely incise the proximal ellipse to preserve a skin bridge to the proximal forearm. In this setting, the lateral arm skin is serving as a rotation flap on this vascular pedicle. These rotation flaps should be purposefully designed to incorporate the lateral wound edge as the posterior margin of the flap to permit insetting of the adjacent skin ( Fig. 4 ). With either of these retrograde flap designs, the proximal PRCA is ligated at the spiral groove to allow mobilization of the distally based pedicle and skin. Flap width and length are variable, but a width of approximately 6 cm will allow for primary closure of the donor site and obviate the need for skin grafting.
Less commonly, the lateral arm flap may be used as an antegrade flap, which is the “extended” design incorporating the proximal dorsal forearm skin. This may be attempted if the wound does not extend significantly distal to the olecranon and the wound margin is used as the posterior margin of the flap. Because the forearm skin envelope is not as redundant as the brachium, a skin graft may be needed for closure of a portion of the donor site.
Outcomes
Tung and colleagues evaluated 7 patients who underwent reversed lateral arm flap for posterior elbow defects and found that complete healing with restoration of full range of motion occurred in all patients. They found that nearly half of patients had forearm parasthesias or scarring issues. Similarly, Prantl and colleagues evaluated 8 patients who had a distally based lateral arm flap. All flaps survived; one complication related to wound breakdown occurred. Hamdi and Coessens evaluated the donor site morbidity of patients who underwent lateral arm and extended lateral arm flaps. They found that subjective patient satisfaction was rated as high and minimal elbow functional change from the contralateral side occurred. In addition, they found an average area of decreased sensation of 45 cm 2 in the posterior lateral aspect of the forearm.
Radial forearm flap
Anatomy
Radial forearm flaps have been used for a wide array of reconstructive procedures as pedicled and as free tissue transfers. The popularity of this flap is based on its ease of dissection, long pedicle, and thin, pliable skin segment. The axis of this flap runs along the length of the radial artery, from the middle of the antecubital fossa to the radial styloid. In the forearm, the radial artery delivers 2 clusters of skin perforators: one in the proximal forearm, and the other in the distal forearm, with the largest skin perforators located within 2 cm of the radial styloid ( Fig. 5 ). This septocutaneous flap has large-caliber vessels, allowing for a robust blood supply with skin perforators in the septum between the flexor carpi radialis (FCR) and brachioradialis (BR).
Technique
The skin paddle taken with this flap is centered on the axis of the radial artery. One must ensure that the pedicle length is adequate to allow for tunneling and rotation of the flap to the posterior elbow area. The axis of rotation is as proximal as the midpoint of the antecubital fossa. Flap elevation begins on either the ulnar or radial side with dissection toward the radial vessels. Retraction of the FCR and BR will aid in visualization and inclusion of the intermuscular septum and the main vascular pedicle within the flap. Great care should be taken to ensure that the dissection is in the subfascial plane of the BR and FCR muscles to ensure preservation of the septal vessels. During dissection of the radial side of the flap, great care should be taken to preserve and protect the dorsal sensory branch of the radial nerve (DSBRN), as it emerges from the dorsal margin of the BR and branches distally.
As an antegrade pedicled flap, division of the radial artery is mandatory to allow for rotation. Once this is performed, proximal pedicle dissection proceeds until sufficient pedicle length is achieved. The donor site usually requires a skin graft for closure ( Figs. 6 and 7 ).
Outcomes
The clinical consequence of a single-vessel hand as a result of radial artery harvest has recently been questioned because of the potential long-term consequences. Long-term studies indicate that flow dynamics in the remaining ulnar artery following radial artery harvest may accelerate atherosclerotic changes. Similarly, Suominen and colleagues found increased peak velocity in the remaining ulnar artery. In addition, they found an 11.9% decrease in grip strength and an impaired thermoregulatory system of the donor hand. While the clinical relevance of these findings are debated, the radial forearm flap remains a commonly used flap for posterior elbow wound coverage.
Jones and colleagues evaluated outcomes following elbow coverage with pedicled radial forearm flaps. On evaluating the donor site of 56 patients, the study described 100% split-thickness skin graft take for donor site closure. In addition, there were no complaints of cold intolerance, dissatisfaction of the appearance, or dysesthesias. Key steps mentioned to improve donor site morbidity include limiting radial extension of the flap to the radial border of the forearm to minimize exposure of the radial sensory branch, advancing skin flaps to close the wound slightly to decrease the amount of skin graft needed, and using nonmeshed skin graft with few fenestrations.
Brachioradialis flap
Anatomy
The BR muscle aids in forearm flexion with an origin of attachment on the lateral supracondylar ridge of the humerus and an insertion on the styloid process of the radius. The dominant blood supply to this muscle is the radial recurrent artery arriving in the proximal portion of the muscle as a proximal branch of the radial artery, or it can have direct connections from the radial artery or brachial artery. The radial nerve is in close proximity to the arterial supply on the underside of the muscle.
Technique
To isolate this muscle, an incision is designed over the proximal radial forearm. The distal tendon is divided at the musculotendinous junction, taking great care to identify and protect the DSBRN. Division of the tendon will allow for expeditious dissection proximally to the level of the dominant pedicle. The dominant vascular pedicle marks the pivot point of the muscle flap. Tunneling the muscle toward the posterior elbow will allow the flap to reach the upper elbow and posterior elbow regions. Skin grafting over the muscle is necessary to complete the wound closure. Negative pressure wound therapy is usually initiated over the grafted area to ensure graft take and limit shearing forces.
Outcomes
BR transfer for posterior elbow wounds allows for an additional advantage of distal tendon transfer. This component can allow for collateral ligament and/or joint stabilization. But, when muscle flaps are disinserted, there is potential for some degree of functional loss. Few studies have reported the donor site morbidity of BR harvest. A recent functional study indicates that the BR primary function is to serve as an elbow stabilizer during elbow flexion tasks. In addition, secondary function was found in pronation activity. When harvested, some loss of pronation may be expected when moving from full supination, but limited morbidity when the forearm is in neutral positions.
A cutaneous portion can be included with this muscle flap. Leversedge and colleagues found that consistent perfusion was located in the cutaneous portion directly above the muscle belly. They found that no cutaneous perfusion was found 1 cm distal to the musculotendinous junction. Including a cutaneous portion may eliminate the need for skin grafting.
Flexor carpi ulnaris
Anatomy
The flexor carpi ulnaris (FCU) is located superficially on the ulnar aspect of the forearm. Two proximal heads (ulnar and humeral) are separated by the ulnar nerve and posterior ulnar recurrent artery. This muscle functions to flex and ulnar-deviate the wrist with attachment at the pisiform. The dominant blood supply is the posterior ulnar recurrent artery and arrives on the deep surface of the muscle close to the origin. Deep along the length of the muscle courses the ulnar neurovascular bundle.
Technique
The incision for harvesting of this flap lies along the axis of a line drawn from the medial epicondyle and the pisiform. The muscle is the most superficial and ulnar of the forearm muscles and the musculotendinous junction is approximately 7 cm from the wrist. Division at this level will allow for quick proximal dissection to the level of the dominant pedicle, which is located approximately 6 cm distal to the olecranon tip and provides the most reliable perfusion to the muscle belly ( Figs. 8–11 ).
Outcomes
Several variations of the FCU flap exist. As a musculocutaneous flap, durable cutaneous paddle can contribute to durability over the olecranon. Skin perfusion is appreciated along the entire aspect of the muscle. An ellipse of skin can be harvested centered over the muscle. In addition, donor site functional deficits can be minimized with the use of a split FCU flap. The 2 proximal heads of the FCU can be differentially split using a flap based on the ulnar head for wound coverage. This portion of the muscle contributes to 75% of the width of the entire muscle. Using this method, limited donor site morbidity results because a large portion of the muscle is left intact.
Latissimus flap
Anatomy
The latissimus muscle is a large, flat muscle extending from the humerus to multiple attachments along the posterior aspect of the thorax and abdomen. The muscle is responsible for adduction, extension, and medial rotation of the humerus. The thoracodorsal vessels, the main blood supply to this flap, are located in an optimal position for pedicled transfer to the chest, arm, and elbow regions. This muscle flap can be taken with a cutaneous paddle centered over the anterior aspect of the muscle, where the abundance of skin perforators exists. This skin segment may be helpful if the wound extends to the posterior brachium. The skin paddle will not reach the olecranon region reliably.
Technique
For muscle flap harvest, a curvilinear incision centered on the oblique axis in line with the humerus attachment provides ample exposure to all aspects of the muscle. Rapid dissection of the muscle from distal to proximal must ensure that the lumbar fascia remains intact and the rhomboids are not accidentally harvested with the muscle. Once in the axilla, care is taken to avoid injury to the thoracodorsal vessels. Subcutaneous tunneling permits this muscle flap to reach the elbow region. Skin grafting is required for coverage of the muscle at the olecranon level.
Outcomes
The wide, large dimensions of this muscle allow for its use in larger defects of the posterior elbow. Donor site morbidity associated with latissimus harvest has been reported to be tolerably low with compensation by other shoulder girdle muscles in short-term evaluation. A recent long-term study suggests joint instability and decreased strength in an average follow-up period of 92 months.
In clinical use, Sajjad and colleagues evaluated 28 patients who underwent pedicled latissimus flaps for extensive soft tissue defects around the elbow. Of the patients,10% had partial flap loss, but all patients went on to heal completely. Stevanovic and colleagues evaluated 16 patients who underwent latissimus flaps for elbow defects of 100 cm 2 . Three patients had partial flap necrosis. The study recommended cautious use of the latissimus flap for wounds 8 cm distal to the olecranon to ensure successful reconstruction.
These caveats were echoed by Choudry and colleagues in a review of 99 cases of soft tissue coverage of posterior elbow wounds. The use of the latissimus dorsi pedicled flap was prone to complication, particularly when the wound extended distal to the olecranon.
Local fasciocutaneous flaps
Anatomy
The precise characterization of perforator anatomy in the area of the elbow has allowed design of cutaneous and fasciocutaneous flaps that can provide adequate soft tissue coverage of posterior elbow wounds. Skin-perforating vessels emerging from the radial artery allow for design of cutaneous flaps. In the distal arm, the radial collateral artery forms a vascular network with the posterior and anterior radial collateral arteries. In the same manner and location of the lateral arm flap, propeller-based flaps can be designed and pivoted off of single skin perforators. A thorough understanding of the vascular connections in the distal arm is necessary to design these flaps. In addition, a handheld Doppler is crucial to isolating these perforating vessels.
Distally, the radial artery has a proximal cluster of skin perforators located in the proximal one-third of the forearm. Located on an axis of the radial artery from the mid-antecubital fossa to the radial styloid, this proximal cluster of vessels serves as potential pedicles for propeller-type flaps. In addition, subcutaneous linking vessels to nearby skin perfusing vessels allow large cutaneous skin paddles to survive off single isolated perforators.
The posterior interosseous artery (PIA) can provide perfusion to a forearm-based fasciocutaneous flap that can be used for soft tissue coverage of the elbow. The PIA emerges from the ulnar artery and lies between the extensor carpi ulnaris and extensor digiti minimi. Cutaneous perforators are found in the middle-third of the forearm.
Technique
Propeller flaps based on the proximal cluster of radial artery perforators are carefully designed because the pivot point may have variability depending on the location of the dominant perforator. A long and narrow cutaneous island design can allow for primary closure of the defect site.
Elevation begins distally and proceeds proximally with examination of each radial artery perforator. Subfascial or suprafascial dissection can be performed as linking vessels travel within the subcutaneous tissues. During proximal dissection, adequate size perforators are kept until a comparison with neighboring perforators can be performed. Once an adequate sized perforator is selected, the flap is “islandized” completely. This will allow for rotation radially toward the posterior elbow region. Inset is complete by either de-epithelializing the flap and tunneling or excising intervening skin to allow for inset. The donor site can be closed if the resulting defect is narrow enough to allow for tension-free closure.
The PIA flap is centered on a line from the lateral epicondyle of the humerus to the distal radial ulnar joint. The middle and distal thirds of this line form the transverse axis of this flap ( Figs. 12 and 13 ). Care must be taken to avoid injury to the dorsal branch of the ulnar nerve distally and the posterior interosseous nerve proximally ( Figs. 14–16 ).
