If you don't remember your password, you can reset it by entering your email address and clicking the Reset Password button. You will then receive an email that contains a secure link for resetting your password
If the address matches a valid account an email will be sent to __email__ with instructions for resetting your password
Address correspondence to Michael R. Hausman, M.D., Department of Orthopaedic Surgery, Mount Sinai Hospital, 5 E 98th St, Ninth Floor, Box 1188, New York, NY 10029, U.S.A.
Malunions are a well-recognized complication of pediatric supracondylar humeral fractures. Results of corrective osteotomies vary, and complication rates have been reported to be as high as 40%. Considering the high rate of complications for malunion correction, we investigated the feasibility of arthroscopy. We present a technique for arthroscopic supracondylar osteotomy and percutaneous pinning. There are many advantages of an arthroscopic approach to malunion correction, including extension-type deformity correction, safe access to the anterior humerus, and minimal dissection and scarring; any intracapsular contracture can be addressed as well. Elbow arthroscopy appears to be a viable option in the pediatric orthopaedic surgeon's armamentarium.
Technique Video
See video under supplementary data.
Supracondylar humeral fractures are common in children aged younger than 10 years.
Considering the high rate of complications for supracondylar humeral malunions, we investigated the feasibility of using arthroscopy. In addition, the complex bony anatomy of the elbow and close proximity of vital neurovascular structures make exposure challenging and, often, limited. Further complicating exposure is the need to avoid damaging the ligaments, which could potentially exacerbate the injury. We present a technique for arthroscopic supracondylar osteotomy and percutaneous pinning.
Indications
The principal surgical indication for this technique is a supracondylar humeral malunion that results in loss of functional motion (Table 1). In addition to addressing bony malunion, this approach affords the surgeon the opportunity to address any intracapsular contracture concomitantly.
Table 1Indications, Contraindications, Tips, and Pitfalls
Indications
Supracondylar humeral malunion with loss of functional motion
Intracapsular contracture
Contraindications
Poor exposure for any reason
Ulnar nerve transposition
Inexperienced elbow arthroscopist
Tips
Start by obtaining perfect radiographs.
Use an adjustable shoulder positioner to easily position the arm in space.
Insufflate the capsule before establishing the portals.
Do not make the portals using stab incisions.
Keep infusion pressures below 20 mm Hg.
Start with the camera in the proximal anteromedial portal.
If performing a contracture release, keep in mind that an in situ ulnar nerve release is generally necessary.
Pitfalls
Poor preoperative osteotomy planning
Failure to examine for a preoperative flexion contracture
Contraindications for this technique revolve around exposure. If arthroscopy does not improve exposure, the procedure should be abandoned in favor of a traditional open osteotomy. In addition, this approach demands an experienced elbow arthroscopist comfortable with pediatric elbow arthroscopy. Lastly, if there has been prior ulnar nerve transposition, we find that elbow arthroscopy is generally contraindicated.
Preoperative Planning
Preoperative planning is necessary to determine the requisite dimensions of the osteotomy and degree of correction. Therefore it is important to obtain good-quality preoperative radiographs. The radiographs must comprise true lateral and true anteroposterior views. Then, using elementary trigonometry and compensating for the magnification factor of the radiographs, we select our osteotomy site and plan for the amount of correction necessary to provide the patient with a functional range of motion. We use the techniques detailed by Kim et al.
to determine the preoperative angles and degree of malrotation. The humerus-elbow-wrist angle is measured on the anteroposterior radiograph as described previously to assess the varus and valgus angles.
Rotational deformity is estimated by physical examination. Again, as described by Kim et al., we determine the extent of internal rotation deformity. Lastly, we determine whether a true flexion contracture exists. When it does, we always prepare for a concomitant arthroscopic contracture release. We also routinely obtain a magnetic resonance imaging scan of the elbow. This allows us to evaluate for a physeal or cartilaginous injury that may require further intervention at the time of surgery. In addition, in concert with stress radiographs, the magnetic resonance imaging scan allows us to evaluate the stability of the ligamentous complexes.
Technique
Figure 1 and Video 1 illustrate the case of an extension malunion in an 8-year-old child, in which the patient had 10° to 100° of preoperative motion. Non-depolarizing general anesthesia and a scalene block are generally used during this technique. We place a nonsterile tourniquet high on the arm, out of the operative field. We routinely position elbow arthroscopy patients in the supine position, using an adjustable shoulder positioner, such as the McConnell arm holder (McConnell Orthopedic Manufacturing, Greenville, TX) (Fig 2). This allows the patient's arm to be placed either across the chest or at the patient's side, conferring multiple advantages: the ability to move the arm in space, easy access for fluoroscopy, easy elevation of the arm to minimize bleeding, and application of longitudinal traction of the arm. The posterior compartment is accessed with the patient's arm across his or her chest, and the anterior compartment is accessed with the shoulder abducted 90° and the humerus parallel to the floor.
Fig 1Preoperative radiographs of extension malunion of distal humerus. The anterior humeral line does not intersect the capitellum.
Fig 2Our preferred patient positioning for elbow arthroscopy: supine with a McConnell arm positioner. (A) Position for access to posterior compartment. (B) Position for anterior elbow access.
Critical landmarks including the ulnar nerve, medial and lateral epicondyles, radiocapitellar joint, and olecranon are marked. Just as in adult elbow arthroscopy, the pediatric elbow is highly constrained with extensive surrounding neurovascular structures. There is even less margin for error than in the adult elbow. Therefore the pediatric elbow joint is insufflated with 8 mL of saline solution to distend the capsule and displace the critical neurovascular structures away from the joint. As in adults, all portals are established with the elbow in 90° of flexion to minimize the proximity of the neurovascular structures. Portals are made close to the capsular insertion on the supracondylar ridge to prevent entrapping capsular tissue between the portals and the humerus, which would decrease joint volume and compromise exposure. Lastly, we only incise the skin: No stab incisions are used. This is followed by blunt dissection through the subcutaneous tissue down to the level of the capsule. This helps to minimize the risk to the surrounding structures by displacing them out of the proposed path before trocar insertion. All trocars are blunt tipped. During arthroscopy, infusion pressures below 20 mm Hg are used. This permits extension of the working time without distending the elbow.
A proximal anteromedial portal is created using a blunt-trocar technique. This portal is often used as a starting point in elbow arthroscopy and offers an optimal view of the entire anterior compartment. It is made 2 cm proximal and 1 cm anterior to the medial epicondyle to avoid injury to the ulnar nerve (Fig 2). When making the portal, the surgeon should use a blunt trocar to pierce the brachialis muscle. The trocar should be slid along the anterior surface of the humerus, aiming toward the radial head. During this portal placement, the structure most at risk is the medial antebrachial cutaneous nerve. A 2.7-mm camera is then inserted through this portal, and the remaining distal, proximal, and anterolateral portals are created under direct vision (Fig 3).
Fig 3Commonly used portals. (A) The lateral portals include the proximal anterolateral portal, 2 cm proximal and 1 cm anterior to the lateral epicondyle; the anterior radiocapitellar portal, directly anterior to the radiocapitellar joint (and closest to the radial nerve); and the posterior radiocapitellar, or soft-spot, portal. (B) Medially, the proximal anteromedial portal, 2 cm proximal and anterior to the medial epicondyle, is most widely used. An additional anteromedial portal can be placed 1 cm distal to the proximal anteromedial portal, but its insertion is more difficult because of the more fibrous common flexor origin tendon in the more distal position. (C) Posteriorly, the trans-triceps portal is supplemented with proximal and distal posterolateral portals for retractors and working instruments. Additional portals can be safely placed along the posterior radioulnar interval.
Next, a 3.5-mm shaver is used to perform the initial debridement, with care taken to direct the instrument away from the capsule and radial nerve. The shaver is then used to clear the anterior humerus of scar tissue and adherent capsule (Video 1).
Once proper visualization is achieved, the joint is inspected to determine whether an arthroscopic osteotomy would achieve the desired effect. For example, when the elbow is flexed to approximately 115°, if the radial head is no longer articulating with the capitellum, then an osteotomy could correct this malalignment (Video 1).
Next, the anterior apex of the deformity is visualized through the arthroscope and marked with a 1.6-mm Kirschner wire. A mini C-arm is brought into position to confirm that the K-wire marks the optimal site of the osteotomy, corresponding to the position previously determined using a template. Then, a 4-mm burr is used to create a transverse, anterior trough across the distal humerus at the supracondylar level (Fig 4). The instruments are exchanged between the medial and lateral portals to facilitate the bone cut, with care taken to leave the posterior cortex intact.
Fig 4Intraoperative radiographs showing arthroscopic osteotomy with 3.5-mm burr. (A) Positioning of burr and arthroscopic instruments. (B) Initiation of osteotomy in anterior humeral cortex. (C) Progression of osteotomy. (D) Completion of osteotomy with correction of extension malunion.
Once sufficient bone has been removed to perform a closing-wedge osteotomy, the distal fragment is flexed forward and the line of the anterior humeral cortex is aligned to match the contralateral elbow. Three 2-mm K-wires are then inserted under radiographic control, two lateral and one medial, with care taken to avoid the ulnar nerve (Fig 5 A and B).
Fig 5(A, B) Intraoperative radiographs after fixation of osteotomy with K-wires. The extension malunion has been corrected, and the anterior humeral line now intersects the capitellum. (C, D) Radiographs at 1-year follow-up. The osteotomy site has healed, and the malunion correction has been maintained.
At this point, elbow flexion and extension are analyzed. If the preoperative examination showed a flexion contracture, then an arthroscopic contracture release is performed. Of note, we routinely perform an in situ ulnar nerve release when we perform a flexion contracture release. If there was no true flexion contracture noted preoperatively but the patient is still lacking extension during surgery, then a contracture release is performed. It is important to explain to the patient preoperatively that this possibility may exist and to obtain consent accordingly.
At the conclusion of surgery, the elbow is flexed and extended to examine the carrying angle and radiographic verification of the alignment achieved is performed. The portals are closed with interrupted No. 6-0 plain gut sutures. The pins are trimmed to the appropriate length, and the arm is placed in a well-padded, long-arm plaster cast with the elbow flexed 90° and the wrist in neutral position. The cast is not bivalved.
Postoperative Rehabilitation Protocol
In the setting of a planned osteotomy, there is still a potential risk of compartment syndrome, just as in a primary supracondylar fracture. In addition, we do not bivalve our casts. Therefore, postoperatively, we admit our patients for observation and pain control and normally discharge them home on postoperative day 1. This affords us the opportunity to bivalve the cast, if necessary, or even remove it.
At 2 weeks, a cast check is performed and radiographs are obtained to verify that the reduction and fixation have been maintained. The cast and pins are removed at 4 weeks, when early bridging callus is seen on radiographs. Only limited use is permitted for another 2 weeks, but the patient is not braced. We allow full active range of motion but no passive range of motion. At 6 weeks, we obtain repeat radiographs. At this point, it is typical that patients can achieve full functional flexion but extension is severely limited. Thus, we routinely provide instructions regarding range of motion and a prescription for specialized occupational therapy. While attempting to regain motion, patients are followed up every 2 weeks or more often. By the 12-month follow-up, patients typically have full extension and flexion (Fig 5 C and D).
Discussion
Children aged younger than 10 years, particularly those aged between 5 and 8 years, are commonly affected by supracondylar fractures of the humerus.
The distal humeral physis contributes 20% of growth to the humerus, limiting the remodeling potential in malunion cases. The 2 most common deformities are cubitus varus (extension-type injuries) and cubitus valgus (flexion-type injuries). Most of the literature regarding malunion after supracondylar fracture addresses cubitus varus deformity. The incidence of cubitus varus has been reported to be as high as 60% in type III fractures.
Cubitus varus is truly a 3-dimensional deformity, which also consists of internal rotation and extension. Many authors believe that cubitus varus deformity is primarily a cosmetic, rather than a functional, disability.
However, studies have suggested that (1) there may be an increased incidence of lateral condyle fractures; (2) a snapping medial triceps over the malunited medial epicondyle can be painful; (3) tardy ulnar nerve syndrome can occur; and (4) tardy posterolateral rotatory instability can occur, eventually leading to degenerative changes in the elbow.
We report a method of deformity correction using elbow arthroscopy with good results. Elbow arthroscopy is commonly used in cases of elbow contracture, and often, bony resection is performed to improve range of motion. Other studies have validated the use of elbow arthroscopy in the pediatric population. Micheli et al.
have reported the safety and diagnostic and therapeutic benefits of elbow arthroscopy in athletically active pediatric patients. Of their 49 patients, none had nerve injury, infection, or postoperative loss of motion. They were able to show that elbow arthroscopy can be performed safely and effectively in the pediatric population by experienced small-joint arthroscopists.
Advantages and Risks
There are many advantages to an arthroscopic approach, including extension-type deformity correction, safe access to the anterior humerus, and minimal dissection and scarring; any intracapsular contracture can be addressed as well. Moreover, arthroscopic procedures, in general, seem less painful to and better tolerated by patients. Although we have not encountered any complications with this technique, potential risks include pin-site infection, osteotomy nonunion, loss of reduction with resultant malunion, stiffness, and neurovascular injury during the arthroscopy.
Limitations
There are limitations of this approach. If it does not improve exposure, the procedure should be abandoned in favor of a traditional open osteotomy. Special attention is required if correction of a cubitus varus deformity mandates an asymmetrical osteotomy. Correction may result in ulnar nerve neurapraxia, and prophylactic in situ ulnar nerve release may be indicated. In addition, this approach requires an experienced elbow arthroscopist comfortable with pediatric elbow arthroscopy.
Regarding our technique, further cases are needed to evaluate the utility of such an approach for other malunion deformities, but elbow arthroscopy appears to be a viable option in the surgeon's armamentarium for pediatric supracondylar malunion correction.
Technique for arthroscopic supracondylar osteotomy and percutaneous pinning presented through an illustrative case of a child with an extension deformity corrected by a closing-wedge osteotomy. Indications, contraindications, tips, and tricks are discussed. Twelve-month follow-up is provided.
References
Otsuka N.Y.
Kasser J.R.
Supracondylar fractures of the humerus in children.
00009-2&id=gr1.jpg){kind=link}
00009-2&id=gr2.jpg){kind=link}
00009-2&id=gr3.jpg){kind=link}
00009-2&id=gr4.jpg){kind=link}
00009-2&id=gr5.jpg){kind=link}