Acute Achilles tendon rupture is one of the most common sports injuries affecting 18 per 100.000 population, and its operative repair has been gaining ground since the mid-1900s. Traditionally, surgical open repair has provided improved functional outcomes, reduced rerupture rates, and quicker recovery and return to activities at the expense of increased wound complications of infection and skin necrosis in comparison to nonoperative management. Ma and Griffith in 1977 introduced the percutaneous approach, and over the following decades, multiple improved techniques, and modifications thereof, have been described with comparable outcomes to the open repair.
The current study aims to provide updated evidence comparing the open and minimally invasive (MIS) through a comprehensive search of literature published in English, Spanish, Portuguese, and German while avoiding limitations of previous studies such as heterogeneous study designs and a small number of included studies.
LEVEL OF EVIDENCE: I, meta-analysis of RCTs
Following the PRISMA guidelines, two independent team members searched several databases to identify randomized controlled trials comparing open and MIS Achilles tendon repairs. The primary outcomes were (1) Sural nerve injury, (2) Skin complications, (3) Infection (deep/superficial) whereas the secondary outcomes were (1) AOFAS/ATRS score, (2) surgical time, (3) re-rupture (4) adhesions (5) ankle range of motion.
Ten RCTs qualified for the meta-analysis with a Total of 522 patients. 260 (49.8%) patients had open repair while 262 (50.2%) had MIS repair. The mean surgical time was 51 and 29.7 minute for open and MIS repair, respectively with statistically significant difference (MD= 21.13, 95%CI= 15.50-26.75, p< 0.001; I2= 15%). The pooled mean total complication rate was 15.5% (0-36.4%) in open repair and 10.4% (0-45.5%) in MIS repair, with non-significant difference (RR= 1.50, 95%CI= 0.87-2.57, p= 0.14; I2=40%). The mean re-rupture rate was 2.5% (0-6.8%) in open repair vs. 1.53% (0-4.6%) with MIS repair, with non-significant statistical difference (RR= 1.56, 95%CI= 0.42-5.70, p= 0.50; I2=0%). No cases of sural nerve injury were reported in the open repair group. The mean sural nerve injury was 3.4% (0-7.3%) in the MIS repair group, that was statistically significant (RR= 0.16, 95%CI= 0.03-0.46, p= 0.02; I2=0%). The mean overall deep infection rate reported in the open group was 1.4% (0-5%) while no deep infection was reported in MIS, with no statistically significant difference (RR= 3.24, 95%CI= 0.48 to 20.54, p= 0.23; I2=0%). The mean overall superficial infection rate was 6.04% (0-18.2%) and 0.40% (0-4.5%) for open and MIS repairs, respectively, with statistically significant difference (RR= 5.70, 95%CI= 1.80-18.02, p< 0.001; I2=0%). Average postoperative American Orthopedic Foot and Ankle Society (AOFAS) score was 94.8 and 95.7 for open and MIS repair, respectively with non-significant difference (MD=-0.73, 95%CI=-1.70-0.25, p=0.14; I2= 0%, p< 0.001). There were no significant differences between open and MIS repair groups in skin necrosis and dehiscence rate, adhesions rate, or keloid scar rate.
Open Achilles tendon repair is associated with longer surgical time, higher risk of superficial infection and ankle stiffness, while MIS repair is associated with greater risk of temporary sural nerve palsy. Re-rupture rate and functional outcomes are mostly equivalent. We found MIS to be a safe and reliable technique, however, high quality standardized RCTs are still needed before recommending MIS as the gold standard for the management of Achilles tendon rupture.