Posterolateral Rotatory Instability of the Elbow: Our Approach

Posterolateral Rotatory Instability of the Elbow: Our Approach

Posterolateral Rotatory Instability of the Elbow: Our Approach Jason A. Stein, MD, and Anand M. Murthi, MD Lateral collateral ligament injuries can be...

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Posterolateral Rotatory Instability of the Elbow: Our Approach Jason A. Stein, MD, and Anand M. Murthi, MD Lateral collateral ligament injuries can be difficult to diagnose and treat. They typically occur because of major trauma but can also be mistaken for more benign causes of elbow pain. In recent years, our understanding of elbow anatomy has allowed us to better diagnose and treat this complex problem. Oper Tech Orthop 19:251-257 © 2009 Elsevier Inc. All rights reserved. KEYWORDS lateral collateral ligament, posterolateral rotatory instability, lateral collateral ligament reconstruction

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ateral collateral ligament (LCL) injuries most often occur after significant elbow trauma. Simple elbow dislocations can also lead to chronic LCL attenuation, and complex fracture dislocations often lead to LCL disruption and elbow instability. Alternately, chronic, indolent LCL attenuation is much more challenging to diagnose. Patients may have received multiple corticosteroid injections,1 may have undergone multiple lateral-sided surgical procedures, or may even have a cubitus varus deformity after supracondylar distal humerus fracture.2 The more subtle injuries often lead to posterolateral rotatory instability (PLRI). Unfortunately, such causes are often overlooked, and many patients suffer for years and seek multiple opinions until they are properly diagnosed. The LCL is composed of 4 major components (Fig. 1). The lateral ulnar collateral ligament (LUCL) inserts distally into the supinator crest of the ulna.3 The annular ligament hooks around the radial neck and stabilizes the proximal radioulnar joint. The radial collateral ligament proper lies anterior to the LUCL. The final component of the LCL is the accessory LCL. In addition to the LCL, the capsule acts as a static stabilizer, especially with the elbow in extension, and the anconeus and extensors act as dynamic stabilizers. If the LCL complex is injured, PLRI can occur. PLRI typically occurs with the elbow in supination and extension with a valgus load. This then causes compression at the radiocapitellar joint without restraint. When compression occurs, the ulnohumeral joint may rotate, causing the radial head to Shoulder and Elbow Surgery, Department of Orthopaedics, University of Maryland, Baltimore, MD. Address reprint requests to Anand M. Murthi, MD, Department of Orthopaedics, University of Maryland, 2200 Kernan Dr, Baltimore MD 21207. E-mail: [email protected]

1048-6666/09/$-see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1053/j.oto.2009.09.014

subluxate or dislocate posteriorly. It is not clear whether an isolated injury to the LUCL is sufficient to cause PLRI, or whether more extensive damage is needed.4 Diagnosis is often the most challenging aspect of elbow surgery, and PLRI is no exception to the rule. Symptoms range from mild mechanical clicking or popping to frank elbow dislocation. Patients may report previous trauma, may have experienced only mild lateral epicondylitis-type symptoms, or may have undergone previous surgery. Elderly patients usually have mild symptoms, whereas younger patients often report histories of traumatic elbow dislocation.4 Physical examination findings can be difficult to elicit in the clinic, while the patient is conscious, because of guarding. Often, the final diagnosis must be made during an examination with the aid of fluoroscopy and the patient under anesthesia. A classic test described in published reports is the supine lateral pivot shift test.3 The patient is placed supine on the examining table, and the elbow is placed in slight flexion and full supination while the examiner applies a valgus load. The radial head can be palpated in its subluxated position. As the elbow is flexed, the radial head locates and the examiner feels it “clunk” back into place. The lateral pivot shift test can also be conducted with the patient in a prone position. Patients are unable to complete push-ups with their forearm in supination compared with pronation. The chair push-up test forces a patient to push themselves up from a chair with their forearm in supination. Pain as the elbow extends is a positive test result. The same position can be elicited by asking patients to flex the elbow as they slide their arm on a tabletop. One can also try to elicit a drawer sign. With the patient supine on the table, bring the arm over the patient’s head and supinate it. Place your index finger under the radial head and thumb over it. If the examiner can feel the radial head sub251

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Figure 1 (A) The lateral ulnar collateral ligament, radial collateral ligament proper, annular ligament, and accessory lateral collateral ligament (LCL) comprise the LCL complex. (B) Supinator crest is an important landmark for the insertion of LCL.

luxate with a posteriorly directed force, it is a positive test result. Imaging studies can also be helpful. However, standard anteroposterior and lateral view radiographs may appear normal. Occasionally, a small avulsion fracture of the lateral epicondyle or degenerative changes of the radiocapitellar joint are revealed. Stress radiographs can be helpful and are best obtained using fluoroscopy. The examiner can perform the pivot shift test. With fluoroscopy, the first sign is posterior migration of the radial head and widening of the ulnohumeral joint. Magnetic resonance imaging arthrograms may identify injuries to the LCL complex but can be difficult to interpret (Fig. 2). Elbow arthroscopy has become more commonplace. We do not advocate performing diagnostic arthroscopy as a routine test, but a pivot shift test can be conducted during the surgery and the radial head will subluxate posteriorly. A “drive through” sign indicates when the camera can easily

pass through the ulnohumeral joint from the posterolateral portal. Unless the surgeon is attempting to perform arthroscopic reefing of the LCL, which is beyond the scope of this article, these signs are useful only if one wants to rule out LCL deficiency while performing other arthroscopic procedures, such as arthroscopic extensor carpi radialis brevis release. If LCL injury is identified early (such as in association with simple elbow dislocation), nonoperative treatment can be attempted. Using a hinged elbow brace in pronation for 4-6 weeks can prevent chronic instability in some patients.5 Patients with mild symptoms might benefit from a neoprene sleeve and physical therapy exercises to strengthen their extensors to improve dynamic stability. If a patient does require operative treatment, several options can be considered. Acute injuries of the LCL can often be repaired, whereas chronic injuries require reconstruction. We discuss several techniques in this study. The Kocher interval, between the extensor carpi ulnaris (ECU) and anco-

Figure 2 (A) Anteroposterior view stress radiograph of the elbow shows posterolateral rotatory instability with complete elbow dislocation. (B) Coronal view oblique magnetic resonance arthrogram shows lateral collateral ligament disruption from its humeral insertion (arrow).

Posterolateral rotatory instability of the elbow

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Figure 3 Patients are positioned supine on an arm table with sterile tourniquet. Lateral or posterior incision can be used. Forearm is pronated to protect posterior interosseus nerve.

Figure 5 Skin flaps are raised. Kocher interval, which lies between extensor carpi ulnaris (ECU) and anconeus (A) is shown.

neus, is typically used for all surgical techniques, and most surgeons are familiar with the approach. A laterally based skin incision may also be used. In some situations in which both lateral and medial procedures need to be performed or the surgeon is concerned that the patient may require total elbow arthroplasty in the future, a posterior incision can be used and a lateral skin flap raised anterolaterally until the Kocher interval is reached. This allows future operations without concern for narrow skin bridges. Typically, the patient is placed supine with an arm board. A nonsterile or sterile tourniquet is used, depending on the extent of the operation. The arm is held in pronation during a major part of the surgery to protect the posterior interosseus nerve (Fig. 3). A 6- to 10-cm incision is made from just proximal to the lateral epicondyle to just distal to the supinator crest of the ulna (Fig. 4). Full-thickness skin flaps are raised, and the fascia of the anconeus and the ECU is identified. Typically, a

raphe exists between the two muscles and a fat streak (Fig. 5). The interval between the two muscles needs to be carefully developed and followed down to the LCL complex. The interval is exposed proximally until the lateral epicondyle and 2 cm of the supracondylar ridge are exposed (Fig. 6).

Figure 4 Lateral-based incision is made over Kocher interval. Incision starts at supracondylar ridge (SR) and travels over lateral epicondyle and radial head (RH), terminating at ulnar crest.

Direct Repair If the patient has incurred an acute injury, the LCL complex can usually be identified and repaired directly. The Kocher interval is used as described previously, and the LCL complex can usually be identified at that point. The LCL complex typically avulses off its insertion into the humerus but can also avulse from the ulna. Once identified, the complex can be reattached to its anatomic sites with bone tunnels or suture anchors and a running, locked Krackow suture. Time should be taken to carefully repair the extensor origin and close the interval between the anconeus and the ECU (Fig. 7).

Figure 6 Remainder of lateral collateral ligament is held by forceps. Joint can be visualized through Kocher interval.

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Figure 9 Fascial band is split into 2 arms of equal width. Figure 7 Illustration shows direct repair of lateral collateral ligament to its humeral insertion through bone tunnels.

Split Anconeus Fascia Transfer: Our Preferred Technique The split anconeus fascia transfer technique was developed as an alternative to the yoke and docking techniques, which are discussed later. The split anconeus fascia transfer technique is our choice if the anconeus fascia is still intact. The advantages of this technique are that it uses local autograft, is biomechanically strong, and minimizes the number of bone tunnels needed, thus decreasing the risk of fracture.6,7 After performing the above-described procedure, expose the anconeus fascia and the distal extent of the triceps fascia (Fig. 8). The graft will be 8 cm long and 1 cm thick starting from its ulnar insertion. It is better to take a longer graft to ensure that it will reach the isometric point of the humeral insertion. Detach the band proximally, and raise the fascial flap off the anconeus muscle. Leave the ulnar attachment intact and split the graft lengthwise (Fig. 9). Pass both bands

Figure 8 A 1.0 ⫻ 8 cm band is mobilized off the underlying anconeus muscle. Ulnar insertion of fascial band (U) is left intact as an anchor.

under the anconeus muscle and bring them into the Kocher interval. Make a small slit distal to the annular ligament and pass the more anterior band of fascia through the slit (Fig. 10). Identify the isometric point of the lateral epicondyle by holding both bands up against the epicondyle and ranging the elbow (Fig. 11). Once the point has been identified, mark both the isometric point on the bone and the lengths of the fascial bands. Add approximately 5-10 mm of length, cut the excess length, and place Krackow stitches with nonabsorbable braided sutures into the bands, which will be used later to secure and tension them through bone tunnels. Use a 5-mm round burr to create a hole into which the dock will be grafted. The hole should be approximately 1.5 cm deep. This depth will allow proper tensioning of the graft and good incorporation of the graft into the bone. Drill 2 holes, 1 anterior and 1 posterior, with a 1-mm side-cutting burr. The 2 holes should have at least a 1-cm bone bridge and should enter the docking hole as deeply as possible to allow proper tensioning. Using a suture passer, the anterior suture from each fascial band is brought through the anterior hole

Figure 10 Anterior band is passed under annular ligament (AL).

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Figure 11 Both bands are then held against lateral epicondyle while the elbow is ranged to identify isometric point.

and the posterior sutures are brought out the posterior hole (Fig. 12). Using different sutures of different colors makes it easier to identify the bands. Place the arm in 40° of flexion and in full pronation, and apply a valgus stress while tensioning the graft. Pull the grafts into the docking tunnel, and tie the sutures over the bone bridge on the supracondylar ridge (Fig. 13). Repair the extensor origin and the Kocher interval. The old attenuated LCL can also be incorporated into the closure to add bulk to the reconstruction.

Revisions In cases with no anconeus fascia, one must obtain a graft, either autograft or allograft (palmaris longus, hamstring, plantaris, etc.), and perform a more conventional reconstruction. The classic technique for this is the yoke technique, but, when possible, we prefer the docking technique, which requires fewer bone tunnels.

Figure 12 Suture passers are used to pass free ends of Krackow sutures through bone tunnels.

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Figure 13 Both fascial bands (arrow) are pulled and locked into isometric tunnel. Grafts are tensioned with elbow at 40° of flexion, full pronation, and valgus stress.

Yoke Technique With the yoke technique, the Kocher approach is performed as described earlier. The lateral epicondyle and the supinator crest of the ulna are exposed. Using a 5-mm burr, 2 holes are made in the ulna. The first is drilled near the supinator crest and the other is drilled 1.25 cm proximal to that, near the insertion of the annular ligament. Care must be taken to avoid breaking the cortical bone bridge while connecting the 2 holes (Fig. 14). Pass a suture through the tunnel that has been created between the holes, and tie it to itself. Hold the free end of the suture against the lateral epicondyle, and range the elbow to find and mark the isometric point. The isometric hole is made at the isometric point and should be wide enough to accept a 3-ply graft. Two more holes are made that connect into the isometric hole, 1 anterior and 1

Figure 14 Illustration shows correct placement of ulnar tunnel. Note that direction of tunnel is perpendicular to direction of isometric point.

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Docking Technique The docking technique is a combination of the split anconeus fascia transfer technique and the yoke technique. A graft needs to be obtained, and the same Kocher approach is used as described previously. Two ulnar holes are made, as with the yoke technique, and a tunnel is created between them. The graft is then pulled through the tunnel. The isometric point of the lateral epicondyle is identified, and tunnel preparation is performed as for the split anconeus transfer: 1 central hole at the isometric point with 2 small holes more proximally for suture passage. The graft is measured and cut so that approximately 5-10 mm of graft will pass into the isometric hole from each end, and Krackow sutures are placed into both ends. The anterior and posterior sutures are passed through the anterior and posterior holes, respectively. The sutures are tied and the graft tensioned as for the split anconeus fascial reconstruction. The wound is then closed as described earlier.

Postoperative Care

Figure 15 (A) First the graft is passed from 1 to 2, with enough graft to reach the isometric point. The end is then sutured to itself, creating the “yoke” stitch. The free end is then passed from 3 to 4. The free ends of the suture used to secure the “yoke stitch” are passed from 3 to 5. The graft is then passed back through the isometric point from 5 to 3. (B) If there is enough graft, it can then be passed from 1 to 2 and then secured. If it is too short, it can be sutured to itself after tensioning.

posterior, on the supracondylar ridge. A bone bridge of at least 1 cm is left intact between the 2 holes. The graft is passed through the ulnar tunnels. Leave the posterior end of the graft long and the anterior end just long enough to reach the isometric point. Suture the anterior end to the posterior graft at the isometric point. This is the “yoke” stitch. The long end is then pulled through the isometric point and out through the posterior hole in the humerus. It is passed over the supracondylar ridge, into the anterior hole, and again out from the isometric point. If length allows, it is again passed through the ulnar tunnel from proximal to distal. If it cannot reach, it can be sutured to itself after tensioning (Fig. 15). As explained earlier, tension the graft with the arm in 40° of flexion, in full pronation, and with a valgus load applied. If the graft is loose, the anterior and posterior bands can be sutured to each other to increase tension. The wound is then closed as described previously.

Immediately after surgery, patients are placed into a posterior splint with the elbow flexed to 40° in pronation to take tension off the graft. We typically replace the splint with a brace 1 week after surgery. From 0 to 3 weeks, the elbow is immobilized and hand and wrist isometrics are allowed. From 3 to 6 weeks, active assisted range of motion is allowed from 20° to 120° in pronation. Flexor and pronator isometrics are initiated. From 6 to 12 weeks, full motion is allowed, including supination. We also allow unrestricted strengthening of the flexors, pronator, and extensors. For 3-6 months, varus stresses to the elbow and ballistic movements should still be avoided. Terminal elbow stretching and resistive exercises as tolerated are allowed. At 6 months, patients are released to activity as tolerated.

Conclusions LCL injuries are difficult to diagnose and treat. When proper diagnosis has been made, ligament reconstructions can be extremely successful. We follow a simple algorithm to determine the best way to treat each patient’s unique pathologic condition. Surgeons should therefore be familiar with multiple techniques. The split anconeus fascia transfer is our technique of choice but is not applicable in all situations.

References 1. Kalainov DM, Cohen MS: Posterolateral rotatory instability of the elbow in association with lateral epicondylitis: A report of three cases. J Bone Joint Surg Am 87:1120-1125, 2005 2. O’Driscoll SW, Spinner RJ, McKee MD, et al: Tardy posterolateral rotatory instability of the elbow due to cubitus varus. J Bone Joint Surg Am 83:1358-1369, 2001 3. O’Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 73:440-446, 1991

Posterolateral rotatory instability of the elbow 4. Nestor BJ, O’Driscoll SW, Morrey BF: Ligamentous reconstruction for posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 74:1235-1241, 1992 5. Cohen MS, Hastings H II: Acute elbow dislocation: Evaluation and management. J Am Acad Orthop Surg 6:15-23, 1998 6. Chebli CA, Murthi AM: Lateral collateral ligament complex: Anatomic and biomechanical testing. Presented at the 73rd Annual Meeting and

257 Scientific Program of the American Academy of Orthopaedic Surgeons, March 2006, Chicago, IL 7. Chebli CA, Murthi AM: Split anconeus fascia transfer for reconstruction of the elbow lateral collateral ligament complex: Anatomic and biomechanical testing. Presented at the 22nd Open Meeting of the American Shoulder and Elbow Surgeons, March 2006, Chicago, IL