Tendonopathy Does Not Predict Rotator Cuff Healing

Abstract

Objectives:Numerous studies have identified risk factors which may decrease the chance of successful rotator cuff healing after surgery. Surgeons may also rely on intraoperative tendon quality to predict healing. There is no data that correlates how the gross tendon morphology and the degree of tendonopathy may impact patient outcome or post-operative tendon healing. The purposes of this study were to 1) compare the gross appearance of the supraspinatus tendon during arthroscopic rotator cuff repair with its histological degree of tendonopathy using the Bonar scoring system, and 2) to determine if either histological appearance or gross appearance correlated with Goutallier grade of fatty infiltration, or post-operative repair integrity. Our hypothesis was that there would be a statistical correlation between gross appearance and histological Bonar score, and that gross appearance would correlate with Goutallier grade and rate of healing.Methods:Demographic data from 105 patients undergoing (supraspinatus) rotator cuff repair were obtained. During surgery, the supraspinatus tendon was rated on thickness, fraying, and stiffness. Tendon tissue was also recovered for histological analysis based on the Bonar scoring system. Post-operative ASES and SST scores, as well as ultrasound assessment of healing, were obtained. Statistical analysis based on demographic data was carried out. Correlation between gross appearance of the supraspinatus tendon and rotator cuff histology (Bonar score) was determined. Correlation of gross appearance with Goutallier grade of fatty infiltration, and with post-operative repair integrity was also determined.Results:Gross appearance of torn rotator cuff tendon tissue did not correlate with histological appearance. Neither hisological score nor gross appearance correlated with demographic data, Goutallier grade, or post-operative repair status. Goutallier grade and vascularity were weakly correlated (rho=0.22, p=0.03)Conclusion:The degree of tendonopathy (Bonar Score) did not correlate with morphological appearance of the rotator cuff tendon, and neither of these parameters correlated with rotator cuff healing or patient outcome. Unlike fatty infiltration, or Goutallier scores, which evaluate the degree of muscle disease, this study suggests that the degree of tendonopathy may not be predictive of suboptimal outcomes. In light of these results, abnormal gross tendon appearance should not impact repair effort or technique.Figure 1:Frequency of total Bonar score among patient populationFigure 2:Hematoxylin and Eosin stained tissue (10x magnification)Table 1:Frequency and percentage rates of Gross Tendon CharacteristicsGross Tendon Characteristics ThicknessFrayingStiffness <50%ofnormalnormal≥ 50%ofnoimalFravingwithfibrillationDelaminatedNofrayingretractedbutmobilizedwith easerecoilednon-retractedtearsFrequency311737343417382619Percentage36%20%44%40%40%20%45%31%22%At the time of surgery a full thickness tear of the supraspinatus was confirmed and AP size of tear was measured using a calibrated probe. The surgeon graded the gross appearance of the supraspinatus tendon using the following system: Thickness (normal, > 50%, < 50%), Fraying (none, fibrillations, delaminated), and Stiffness (not retracted, mobilizes with ease, recoils).Table 2:Bonar and patient demographic correlations AgeGenderRepair StatusGoutallierThicknessFrayingStiffness rho p value rho p value rho p value rho p value rho p value rho p value rho p value Tenocytes 0.040.69-0.20.060.070.510.110.320.030.77-0.060.620.020.83 Ground Substance 0.50.630.010.95-0.130.250.050.660.030.740.080.450.130.24 Collagen -0.070.550.080.46-0.260.260.150.170.040.720.10.34-0.270.01 Vascularity 00.97-0.030.79-0.020.830.220.030.060.560.130.230.080.46 Total Score 0.010.92-0.090.39-0.060.580.190.080.060.610.090.420.020.88Repair Status (intact vs. torn), Goutallier (Stages 0 to 4), Thickness (normal, < 50%. ≤ 50%), Fraying (none, fibrillations, delaminated), Stiffness (not retracted, mobilizes with ease, recoils)The average Bonar score was 7.5 ±2.7 with a range of 3 to 12. Comparison of the four categories of Bonar as well as the total score with gross appearance of the supraspinatus tendon (thickness, fraying, and stiffness), demographic variables (age, gender, etc.), postoperative repair status (intact vs. torn) and outcome scores, and pre-operative fatty infiltration (Goutallier)Table 3:Frequency and percentage rates of Bonar scoring of supraspinatus tendon biopsy Bonar Grade 0 Bonar Grade 1 Bonar Grade 2 Bonar Grade 3 Frequency Percentage Frequency Percentage Frequency Percentage Frequency Percentage Tenocytes 22%1922%2732%3744% Ground Substance 00%1922%2833%3845% Collagen 11%2327%3137%3035% Vascularity 4857%78%89%2226%Bonar scoring uses a 4 point system where 0 = normal tendon appearance, 1= slightly abnormal tendon appearance (10-20% of the whole tissue), 2 = a relatively abnormal appearance (20-% of the whole tissue) and 3 = markedly abnormal tendon appearance. The total score for each tendon can range from 0 (normal tendon) to 12 (most abnormal appearance). Each tendon was evaluated for 4 different variables: (1) tenocyte; (2) ground substance or GAG; (3) collagen alignment and (4) vascularity as described by Maffulli et al.