Double-limb graft MPFL reconstruction yielded superior outcomes to single-limb graft
Compared with single-limb grafting, double-limb graft medial patellofemoral ligament reconstruction yielded superior clinical and patient-reported outcomes for the treatment of recurrent patellar dislocation, results showed.
Researchers at West China Hospital in Chengdu, China, used PubMed, Embase, Web of Science and Cochrane Library databases to perform a meta-analysis of four randomized controlled trials and three cohort studies (n = 451 patients) that compared single-limb and double-limb graft MPFL reconstructions. Outcome measures included postoperative recurrent patellar instability, anterior patella-related pain, patellar lateral shift rate, Kujala score, Tegner score and IKDC score, according to the study.
Overall, both single-limb and double-limb graft MPFL reconstructions improved joint stability and functional scores from preoperatively to postoperatively. However, researchers found double-limb graft MPFL reconstruction exhibited superior outcomes for recurrent instability, anterior patella-related pain and patellar lateral shift rate compared with single-limb grafting. Postoperative instability was found in 4.4% of the single-limb group and 0% of the double-limb group. The single-limb group had a 10.68% reduction in the patellar lateral shift rate, while the double-limb group had a 12.24% reduction in the patellar lateral shift rate.
Functional recovery scores also favored double-limb graft reconstruction, according to the study. The double-limb group had significantly better Kujala score improvement (weighted mean difference [WMD] = –3.53), superior Tegner score improvement (WMD = –0.55) and better IKDC score improvement (WMD = –4.8) compared with the single-limb group. Lysholm scores were similar between the groups, researchers noted.
“Regarding complications, [double-limb] DL graft reconstruction has a theoretically higher risk of patellar fracture. However, there was no statistically significant difference between the techniques in the rates of patellar fracture (0.44% in the [single-limb] SL group and 0.83% in the DL group),” the researchers wrote in the study.
“This meta-analysis supported our hypothesis that DL graft MPFL reconstruction can yield superior clinical outcomes than SL graft MPFL reconstruction for recurrent patellar dislocations,” they concluded.
“The amount of high-quality evidence is insufficient, so this conclusion should be interpreted with caution,” they added.
Perspective
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MPFL reconstruction has become the most common surgical stabilization procedure for recurrent patellar instability in the absence of significant patella alta or severe trochlea dysplasia. Pang and colleagues performed a meta-analysis of clinical studies looking at single-limb vs. double-limb MPFL reconstruction techniques. They included four randomized clinical trials and three cohort studies for a total of 451 patients. The authors concluded that double-limb MPFL reconstruction provided better results across a range of outcomes measures.
Although there are multiple MPFL reconstruction techniques, a double-limb graft with two fixation points on the patella and one fixation point on the femur is the most common technique used. The MPFL has a broad insertion on the superior third of the patella medial border and a narrow insertion on the femur in the saddle between the medial epicondyle and the adductor tubercle. It makes intuitive sense that double-limb grafting works better than single-limb grafting, and this study suggests that is true. Possible etiologies for this include broader recreation of the patella insertion footprint, increased biomechanical strength or increased collagen. Although the literature on MPFL reconstruction is still far less than that of ACL reconstruction, it is nice to see more MPFL reconstruction studies that examine technique.
Perspective
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Double-limb grafting is a legitimate approach to medial patellofemoral complex reconstruction. In 2019, my colleagues and I published a technique which avoids the second drill hole by using medial quadriceps tendon femoral ligament (MQTFL) reconstruction for the upper limb. However, as it has been said about ACL reconstruction of two bands, now two limbs must be correctly tensioned. I have seen more problems from MPFL reconstructions that are too tight than problems from ones that are too loose. So, I remain a strong advocate of single-band MQTFL reconstruction as it has a very high success rate with no drill holes and no fracture risk. It’s also easier to tension, which reduces the risk for problems. Meanwhile, I applaud the authors for their excellent technical precision.
Reference:
Joseph SM, et al. Arthroscopy Techniques. 2019; doi:10.1016/j.eats.2018.09.002.
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