Summary

In a large prospective cohort study comparing anterior cruciate ligament reconstruction using a quadriceps tendon (QT), semitendinosus-gracilis, or bone-patellar tendon-bone (BPTB) graft, only two re-ruptures occurred (1 BPTB, 1 QT), and no differences between grafts were found with respect to function, quality of life, or activity based on patient reported outcomes at 1-year post-operative.

Abstract

Introduction

The purpose of this study was to compare re-rupture rates, quality of life, and functional outcomes between patients undergoing anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB), semi-tendinosis-gracilis (STG), or quadriceps tendon (QT) graft at 1-year post-operative.

Methods

This was a prospective cohort study of 297 patients comparing ACLR using one of three grafts, BPTB, STG, or QT, with 99 patients in each group. Patients were >13 years old, skeletally mature, and from one centre. Those with previous ACLR surgery on either leg were excluded. ACL re-rupture was the primary outcome. Secondary outcomes included patient-reported outcome measures (PROMS), specifically ACL-QOL, Marx Activity Rating Scale, SANE score, and Tegner Activity score, as well as peak concentric flexion and extension torques as measured on a dynamometer, and presented as limb symmetry indices, affected/unaffected limb. Annual data collection is ongoing to 5-years post-operative. To characterize early stages of recovery, 1-year post-operative results are presented here.

Results

Two-hundred and ninety-nine patients were consented and 294 participated beyond baseline (97 BPTB, 98 STG, and 99 QT). Mean (SD) age in the QT group was significantly younger (25.1±7.9 years) than BPTB (28.0±8.6) and STG (29.4±9.2) and the proportion of males and females was approximately 50% for all groups (p=0.900). Only two ACL re-ruptures were reported by 1-year post-operative, one in the BPTB group and one in the QT group, and no contralateral ruptures were reported. There were no differences between groups in post-operative mean ACL-QOL (range 67.8-73.7; p=0.132) or SANE scores (range 80.7-81.8%; p=0.858). Differences in Marx Activity Scores were tending towards significance between groups with the lowest mean score in the STG group (6.1±4.5) compared to 7.5±4.7 and 7.6±4.5 for BPTB and QT, respectively (p=0.067). There were no differences between groups with respect to Tegner Activity score with mean values ranging from 5.4 to 5.9 (p=0.232). Patients’ 1-year Tegner scores were, on average, 1.8 to 2.2 levels lower than the level they recalled being at pre-injury, and these values did not differ between groups. With regard to strength, the knee extension limb symmetry index was lower in the QT group at 65.1±16.4% compared to 72.0±19.1% for BPTB (p<0.001) and 77.4±20.1% for STG (p<0.001). The knee flexion limb symmetry index was significantly lower in the STG group at 86.5±13.4% compared to 95.5±15.2% for BPTB (p=0.003) and 96.3±14.4% for QT (p=0.005).

Conclusions

At 1-year post-operative, only two re-ruptures were reported (1 in BPTB and 1 in QT). No differences between graft types with respect to function, quality of life, or activity level, as measured by PROMS, were found. More substantial deficits in knee extension strength were identified in those with a QT graft, and in knee flexion strength in those with an STG graft. It is notable that strength deficits, especially in knee extension, were evident at 1-year regardless of graft, which should be considered when clearing patients for return to full activity. Data collection will continue over the next four years to more definitively understand how different graft types impact patient outcomes.