Lateral ulnar collateral ligament reconstruction of the elbow using a triceps tendon autograft—a technical note

The online version of this article (https:// doi.org/10.1007/s11678-022-007219) contains the video: “Triceps tendon harvesting for lateral ulnar collateral ligament reconstruction of the elbow”. You will find the video at the end of the article as “Supplementarymaterial.” Video by courtesy of C.J. Pucher, F. Lanzerath, M. Hackl, and L.P. Müller, Department of Trauma, Hand and Elbow Surgery, University Hospital of Cologne, Germany; all rights reserved 2022.


Background
Lateral collateral ligament (LCL) reconstruction is particularly important in patients with recurrent posterolateral rotatory instability (PLRI) of the elbow. Caused by traumatic or atraumatic insufficiency of the LCL complex, this pathology represents the most common form of elbow instability [1]. Patients complain of lateral-sided elbow pain accompanied by mechanical symptoms such as clicking, locking, or instabilities [2]. As the lateral ulnar collateral ligament (LUCL) represents the primary constraint against PLRI, LUCL reconstruction is mandatory for its surgical treatment [1]. However, the following technique utilizing a triceps tendon autograft has several advantages including simple graft harvest, preservation of still-intact LCL fibers, minimal release of the common extensor tendon, and anatomical LUCL reconstruction.
Accordingly, the purpose of this Technical Note is to provide a detailed description of how to perform triceps tendon harvesting for LUCL reconstruction. Special attention is paid to the surgical steps of graft harvesting und preparation, as this procedure may also be used for medial ligament reconstruction with only slight modification.

Graft harvesting
In the present technique, the patient is placed inthelateral positionwiththeupper arm flexed at 90°and supported in a tray and the elbow joint hanging freely.
Before the skin incision, all bony landmarks should be marked including the medial and lateral epicondyle, the olecranon, and the radial head. A 5 cm posterior incision is made proximal to the olecranon tip. After careful preparation through the skin and subcutaneous tissue, the triceps tendon aponeurosis is visualized. Since the ulnar nerve is potentially at risk during graft harvesting, we located it at the medial edge of the triceps tendon and exposed its course proximal to the cubital tunnel. However, visualizing of the ulnar nerve is not necessary in every case.
For LUCL reconstruction, a strip of 7 cm length and 5 mm width can be dissected from the ulnar third of the superficial triceps tendon aponeurosis (. Fig. 1a). For medial ligament reconstruction, a length of 5 cm is generally sufficient. Since the strip should not be detached directly from its bony insertion on the olecranon tip, a lip of 5 mm is left on the bone. While still in situs, a modified Krackow suture with a no. 2 nonabsorbable thread is placed on the distal end of the graft (. Fig. 1b). Then, the strip can be detached proximally, and the resulting defect is closed with a running locked stich.

LUCL reconstruction
Ulnar side For the subsequent LUCL reconstruction, the arm should be transferred to a side table with the elbow joint resting on its ulnar side and flexed 90°. A 7 cm incision is made from the lateral epicondyle Kocher's interval between the anconeus and the extensor carpi ulnaris muscles is identified. The fascia is sharply incised at the level of the supinator crest. This is followed by blunt dissection down to the capsule. It is crucial to protect the lateral capsule since the ligament will ultimately be reconstructed in an extra-articular position.
On the ulnar side, the graft is anchored using a cortical button technique. Therefore, the free threads attached to the triceps strip are passed through an endobutton in standard fashion. After the base of the annular ligament at the dorsoradial edge of the ulna has been accessed, the insertion of the LUCL at the supinator crest is identified and confirmed radiologically. At this point, the bone is reamed monocortically with a 3.2-mm drill bit so the button can be inserted intramedullary and flipped (. Fig. 2a). The graft is pulled to the bone via the sutures, knotted, and checked for stability. Repair-site gapping should be avoided as it may cause poor tendon-tobone healing. The remaining ulnar sutures can be preserved and used as a ligament bracing for additional stability (. Fig. 2b).

Humeral side
Once the ulnar fixation is completed, attention is turned to the humeral side. To avoid damage to the remaining fibers of the LCL complex, the capsule is incised in line with the LUCL, just anterior to the posterior margin of the common extensor tendon. The graft and remaining threads are tunneled between the fascia, the anconeus muscle, and the capsule toward the isometric center (. Fig. 2b). The material should not come into direct contact with bone or cartilage structures, as this may cause crepitation and pain in the postoperative course.
An appropriately positioned humeral attachment side should provide an isometric reconstruction that maintains the same tension throughout the full range of motion (ROM). After the humeral isometry point at the lateral epicondyle has been identified and confirmed using the remaining ulnar sutures, the graft should be shortened to the optimal length. It is provided with a second no. 2 nonabsorbable suture at the proximal end and secured in the isometric center with a knotless suture anchor (. Fig. 2c). Finally, additional ligament bracing can be carried out by knotting the remaining humeral and ulnar sutures.
To avoid overtightening a further stability and mobility test should be performed before the fascia is closed from distal to proximal. Subcutaneous and skin sutures follow.

Postoperative care
Postoperatively, a ROM orthosis with a flexion/extension setting of 90-10-0°is recommended for 4 weeks and an additional 2 weeks without ROM restriction. The ROM may be practiced with the splint in place from the beginning of physiotherapy [3]. In particular, overhead ROM exercises in the supine position can be helpful to restore mobility and stability.

Discussion
Reconstruction of the LUCL remains the primary therapy for symptomatic PLRI. Sanchez-Sotelo et al. reported satisfactory results in 86% of patients in a retrospective follow-up investigation at a mean of 6 years (2-15 years) after reconstruction with a similar procedure [4]. These results have been confirmed in several other small case series and a systematic review by Badhrinarayanan et al. [5]. Although different techniques for graft harvesting and LUCL reconstruction have not been adequately evaluated and compared in the literature, we believe that the surgical procedure described in this technical note has some distinct advantages: These include no reported graft side morbidity (as shown in a systematic review by Hagemeijer et al. [6]), isometric ligament reconstruction, minimal release of the Fig. 2 8 Lateral view of a left donor elbow:1 extensor carpi ulnaris muscle, 2 anconeus muscle, 3 LUCLinsertion at the supinatorcrest,4commonextensortendon,5remainingulnarsutures,6remaininghumeralsutures. aInsertionoftheloadedcortical button through the monocortical thrill hole at the ulnar isometry center on the supinator crest.b Graft tunneling between the fascia, the anconeus muscle, and the capsule toward the lateral epicondyle.c Humeral fixation of the augmented graft on the humeral isometry center using a suture anchor common extensor origin, preservation of preexisting LUCL fibers, and a high rate of restored elbow stability. Recently, a similar procedure with a minimally invasive approach was described by Voss and Greiner [7]. In this paper, however, we opted for a modified Kocher approach for a better overview when shuttling the graft. We also used the remaining sutures for an additional ligament bracing.
A potential disadvantage of this approach is the need for accurate anatomical knowledge and technical precision for isometric ligament reconstruction using a suture anchor for humeral graft fixation.  For this article no studies with human participants or animals were performed by any of the authors. All studies mentioned were in accordance with the ethical standards indicated in each case.

Christoph-Johannes Pucher
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