The main finding of our study is that both procedures lead to improvements in clinical outcome with a low complication rate and a high rate of healing. No signifcant difference in clinical outcome was demonstrated between these two procedures for articular-sided partial rotator cuff tear repair.
Articular PT-RCTs with a thickness of greater than 50% can be repaired by tear completion repair and the in situ transtendon procedure. Tear completion repair is a relatively straightforward method for restoration of the tendon footprint with satisfactory clinical outcomes and high levels of patient satisfaction. Some authors advocated tear completion repair because it allowed better access to the tendon footprint and tended to be more convenient to secure tendon fixation.6 Furthermore, after the removal of degenerative tissue, it could obtain an advantageous healing microenvironment that is akin to an acute full-thickness tear.1, 15 Gereli et al found the completion repair technique exhibited increased healing characteristics compared with the in situ technique in spite of the concerns of detaching the intact tendon.9 The reason for this finding might be the refreshing effect of debridement at the chronic degenerated tendon that could improve the healing response.9 Although this technique achieved good clinical outcomes, it cannot to anatomically repair the lesion and restore native length–tension match after surgery.8, 13 Therefore, some authors raised its concerns of biological and mechanical flaws, which could reduce tendon integrity potential and result in functional disabilities overtime.
In contrast, the transtendon repair made it possible to better restore the rotator cuff footprint anatomically and maintain the tendon integrity as preserving the bursal-side rotator cuff tendon.1 Cadaveric study has demonstrated that transtendon repair technique creates smaller gap formation and higher ultimate tensile loads than tear completion repair technique.10, 23 Meanwhile, some studies have found that transtendon repair is an effective treatment for articular PT-RCTs with significantly improved functional scores and pain relief.3, 8, 24, 25 Despite complete integrity, slower shoulder functional improvements during the recovery period and higher occurrence rate of postoperative shoulder stiffness after transtendon repair have been reported. 11, 14, 21 Jordan R W et al reviewed the incidence of post-operative stiffness of articular PT-RCTs using transtendon repair or tear completion repair.14 The included case series demonstranted a higher rate of stiffness in the transtendon repair group (range 0 to 18% compared to 0 to 2.8% after completion and repair). Furthermore, the shoulder discomfort after the transtendon repair technique might was caused by unbalance the tension of the remaining torn cuff because of a retracted articular rotator cuff layer and overtightening the bursal portion of the cuff.4, 12, 25 This altered tensioning on both sides of rotator cuff tendons may be the cause of the shoulder stiffness. Although various modifications of transtendon repair techniques have been introduced to avoid overconstraining the joint and tendon overstrain, improved arthroscopic instruments and transtendon repair techniques are needed to reduce risks of postoperative morbidity.25 On the other hand, the remaining cuff tissue has already showed histopathological degeneration and would be a painful nidus causing early postoperative pain.9, 27 Yamakado, Kotaro has taken biopsy specimens of the residual tendon in 30 consecutive patients with articular-side PT-RCTs.27 Samples were histopathologically examined and graded by use of a modified semiquantitative scale. The study showed that degenerative changes were evident in 28 of 30 cases (93%) and over 90% of the macroscopically intact residual tendon showed moderate histopathologic degeneration. But no difference was found between the 2 repair techniques with respect to VAS score in the present study. Further studies are required to determine the effect of remaining cuff tissue on early postoperative recovery and long-term clinical outcome. These findings together suggest that the biomechanical advantage of preserving the tendon integrity with transtendon repair does not provide better functional results and healing rates compared with tear completion repair.
The limitations of this study include a relatively small number of studies. Despite the small sample size, we included only level- II studies. Hence, these studies represent high-level evidence on a large number of patients. The preliminary results presented in this study would help to clarify technical characteristics of both repair techniques. In addition, the heterogeneity of imaging modality may represent a weakness of the study. There is a lack of standardized evaluation method for accurate assessment of tendon thickness. According to previous report, ultrasound and MRI have good and similar diagnostic accuracy for detection of rotator cuff tears, and they has been widely performed to evaluate the rotator cuff integrity.18