The goals of rotator cuff repair remain the same whether the repair is performed in an arthroscopic or open fashion. These goals include pain relief, improved function, and possibly prevention of rotator cuff arthropathy. Although arthroscopic rotator cuff repair is widely performed by orthopaedic surgeons, the optimal technique for maximization of tendon-healing and clinical outcome has yet to be definitively established. Despite well-documented excellent short-term clinical outcomes obtained with arthroscopic single-row rotator cuff repair, reports of relatively high rates of recurrent tearing have led to an interest in so-called “footprint restoration” in hopes of improving the healing rate and long-term outcome of rotator cuff repair1.
Double-row repair has been shown in multiple biomechanical studies to be superior to single-row repair with regard to footprint restoration, tensile strength, gap formation, and the number of cycles to failure2-4. However, no study has definitively demonstrated improved clinical outcome with use of double-row repair. Recently, Denard et al. retrospectively reviewed the results of arthroscopic repair of massive rotator cuff tears using single-row and double-row techniques at a minimum of five years, and better long-term functional outcome and an improved subjective result were noted when a double-row repair was performed5. However, a recent meta-analysis of Level-I and II prospective comparative studies by Dehaan et al. showed only a trend toward a better functional outcome and a lower retear rate for double-row repair; no significant differences were found between the two techniques1.
One of the difficulties that arise in interpreting the results of such studies is that the specific technique may vary widely among so-called “single-row” and “double-row” repairs with regard to the number of anchors, number of sutures, and specific suture configuration. It is important to establish that one is comparing “apples to apples” when attempting to form conclusions regarding the effect of surgical technique on outcome.
Lapner and colleagues should be commended for carrying out a methodologically sound Level-I study comparing single and double-row rotator cuff repair. They performed a multicenter randomized controlled trial that used validated outcome measures including the Western Ontario Rotator Cuff Index (WORC), which is a disease-specific quality of life measure for rotator cuff disease, as well as the American Shoulder and Elbow Surgeons (ASES) score and the Constant score. Shoulder strength in forward elevation was also documented. Similar, although not identical, techniques for single and double-row repair were utilized at the two institutions at which the study was performed. It should be noted that the single-row repair included double-loaded anchors placed along the lateral edge of the footprint. Mattress or inverted-mattress sutures were used. The double-row repair included two rows of double-loaded suture anchors placed along the medial and lateral aspects of the footprint. The medial-row anchor sutures were not tied or linked to the lateral anchors, and thus this was not a so-called “transosseous-equivalent” repair. Massive rotator cuff tears that included fatty infiltration of grade 3 or greater and/or superior subluxation of the humeral head with an acromiohumeral distance of <7 mm were excluded.
The authors found that the rate of healing in the double-row group was not significantly different from that in the single-row group in the univariate analysis. Additionally, no statistically significant differences were observed between the groups for the WORC, Constant, ASES, or strength scores. However, multivariate analysis adjusting for age, sagittal tear size, number of anchors, and baseline outcome scores indicated that smaller initial coronal tear size and double-row fixation were associated with higher healing rates.
Limitations of this study are those common to any such trial and include a loss of follow-up of 19% as well as the potential for selection bias because the surgeon determined the final eligibility of each patient on the basis of intraoperative findings. Additionally, two different surgeons performed the procedure, and some latitude was allowed with regard to the surgical technique. Finally, the imaging modality utilized to determine healing varied according to center, being either magnetic resonance imaging or ultrasonography. Despite these limitations, the study provides further evidence of a potential benefit involving the tendon-healing rate for double-row compared with single-row repair constructs. One might assume that statistically significant improvement in the healing rate will translate into improved clinical and functional outcomes over the long term; however, this has not been clearly established. It is important to note that the potential drawbacks of double-row repair include increased cost and increased technical difficulty of the repair. Additionally, the optimal pressure for maximizing tendon-to-bone healing at the footprint is undetermined, and it has been suggested that some double-row techniques might even compromise healing by decreasing vascularization of the tendon at the footprint6.
In summary, the optimal technique for arthroscopic rotator cuff repair remains controversial. The evidence appears to be mounting that footprint restoration, which is most readily achieved with a double-row repair construct, is likely to improve the rate of healing. Thus far it has not been definitively shown that the use of a double-row construct for arthroscopic rotator cuff repair leads to significant improvement in clinical and functional outcomes at early follow-up. Larger prospective controlled trials with longer follow-up are needed to definitively determine the optimal surgical technique and in turn maximize longer-term outcomes.