Indication according to the algorithm
Biological age: young patients with high demands
Chief complaint: weakness; weakness for flexion > weakness for external rotation
Pattern of irreparable RCT: A, C, D
Strengths and weaknesses
+ Long-term data available showing sustained improvement even after 12 years. Great excursion of the latissimus muscle, no graft needed, low implant costs (2–3 anchors).
− Technically challenging, treatment outcome dependent on the integrity of the teres minor and subscapularis muscle, partially open procedure, latissimus function out of phase (internal rotator, vertical force vector).
Risk factors for poor outcome: shoulder stiffness, irreparable subscapularis tear, teres minor atrophy, pseudoparalysis, high critical shoulder angle, previous rotator cuff surgeries.
The pioneering description of LDT for chronic posterosuperior RCTs was presented by Gerber in 1988 .
The latissimus dorsi acts as a powerful internal rotator, adductor, and extensor of the humerus in the glenohumeral joint. The force vector is significantly more vertical than the lower trapezius portion due to its natural course. However, the latissimus dorsi muscle exhibits such good excursion that the tendon can be inserted directly at the superolateral facet of the greater tuberosity. The transfer restores the force couple of the rotator cuff, allowing centering of the humeral head during deltoid activation.
The procedure was first described as an open procedure in a lateral decubitus position . Nowadays, the majority of the procedure is arthroscopically assisted, with the patient in the beach chair position and the tendon being harvested openly through a skin incision along the posterior axillary fold . The all-arthroscopic technique has also been described, although it has not yet become widely performed . The advantages of the arthroscopically assisted approach are the ability to supply the subscapularis tendon, perform a partial repair of the posterosuperior rotator cuff tendons if possible, sparing of the deltoid muscle, and less scarring.
There are several descriptions of arthroscopically assisted LDT. A particularly illustrative presentation of the single surgical steps can be viewed on VuMedi. link: https://www.vumedi.com/share/a5eb4a01-32d6-4aac-a300-3b099041e440/.
Herein, the authors focus on the pearls and pitfalls of the technique:
In beach chair positioning, an arm holder can be attached ipsilaterally. With maximum flexion and internal rotation of the arm, the posterior axial fold, which corresponds to the latissimus dorsi muscle and tendon, is stretched to the maximum. In this position, the skin incision and harvest of the tendon from the humerus should be performed.
The latissimus tendon is wide and long, and the teres major tendon is short. The layer between the latissimus tendon and muscle belly must be clearly separated before tendon release. Tendon release can be performed either openly via the axilla or arthroscopically.
The latissimus muscle has a very high excursion if the muscular release is performed adequately. The muscle belly should be released posteriorly and far distally. Anteriorly, attention must be paid to the nerve pedicle, which enters the muscle anteriorly about 14 cm distal to the tendinous attachment.
The layer between the deltoid muscle and the posterior cuff muscles (infraspinatus and teres minor) should be dissected wide open, both from intraarticularly and via the open approach posteriorly to allow the tendon transfer to glide freely.
Fixation of the tendon.
The anteromedial and anterolateral tagging sutures are fixed anteriorly at the superolateral aspect of the greater tuberosity via knotless anchors. The fixation is facilitated if the respective sutures are shuttled out through a separate anteromedial and anterolateral portal. A third anchor might be needed at the posterior aspect or the greater tuberosity to avoid windshield whipper effect of the tendon.
Patient compliance is important and should be assessed preoperatively. Postoperative immobilization in a 30-degree abduction pad for 6–8 weeks. Passive and active assistive exercise therapy after 8 weeks, gentle strengthening after 12 weeks, and transition to full weightbearing after 16 weeks.
A major strength of LDT as a treatment option is that it is the only therapeutic option for the treatment of IPRCT for which long-term results are available [10, 16]. In the study by Gerber et al., with a mean follow-up of 12 years (minimum follow-up of 10 years), it was shown that shoulder function (Constant score % pre- vs. postoperative: 56 vs 80%) and patient satisfaction (subjective shoulder value from preoperative 29 to postoperative 70%) of 44 patients with 46 operated shoulders were sustainably improved over this long period . Mid-term results of the newer arthroscopically assisted technique are also available and do not differ significantly from the open technique . Long-term failure rates range from 10%  to 14%  and 30% .
Over the years, the following risk factors for poor outcome have been identified: fatty atrophy of the teres minor muscle, preoperative pseudoparalysis, excessively high critical shoulder angle, irreparable subscapularis tear, shoulder stiffness, and previous rotator cuff procedures.