Summary

Central transpatellar tendon portal used for ACL reconstruction does not lead to significant complications, disadvantages and radiological alteration in comparison with ACL reconstruction with standard portals.

Abstract

Objectives: during knee arthroscopy several portals can be used to address specific lesions and carry out different tasks. The use of a central transpatellar tendon portal (CTTP) as a view portal for anterior cruciate ligament (ACL) reconstruction allow a perfect visualization of the femoral foot print. Some studies have been published about possible poor outcomes using this portal for meniscal repair or meniscectomy. To the best of our knowledge no studies evaluated clinical and radiological outcomes after ACL reconstruction using this portal. Our hypothesis was that the use of central trans-patellar portal does not led to clinical or radiological alterations after ACL reconstruction in comparison with reconstruction through standard portals.

Methods

patients operated by 4 experienced surgeons with an anteromedial portal ACL reconstruction technique were revised. Two of them always performed CTTP as view portal, the other two performed an accessory anteromedial portal. Exclusion criteria were: 1) reconstruction with patellar or quadriceps tendon 2) previous knee surgery 3) history of anterior knee pain 4) multi-ligament reconstruction 5) cartilage treatment of both patella and trochlea, meniscal transplantation or high tibial osteotomies performed at the same surgical time 6) lacking of preoperative and/or postoperative clinical or radiological evaluations. The following parameters were evaluated: postoperative anterior knee pain, postoperative infection, patellar tendon rupture, quadriceps muscle tropism, MRI signal of patellar tendon and infrapatellar fat pad, patellar height. The latter was evaluated by radiological indexes: Caton-Deschamps (CDI), Insall-Salvati (ISI), Modified Insall-Salvati (MISI).

Results

84 patients were reviewed with a mean follow-up of 42 months. In 43 cases was performed a CTTP (group 1), in 41 was performed an accessory anteromedial portal (group 2). Mean post-operative values in group 1 were: CDI 1,02 ISI 1,04 MISI 1,73 (mean pre-operative: CDI 1,06 ISI 1,05 and MISI 1,8). Mean post-operative values in group 2 were: CDI 1,05 ISI 1,06 MISI 1,72 (mean pre-operative: CDI 1,08 ISI 1,06 and MISI 1,79). No significant differences were observed between mean preoperative and postoperative CDI, ISI and MISI both in group 1 and 2. No patients in group 1 developed a postoperative patella baja. In two cases the CTTP was performed in patients with a preoperative CDI < of 0,8 and no complications occurred. At the latest follow-up, no patients had pain or tenderness at the patellar tendon. In 5 patients we found alterations in MRI signal of the patellar tendon at latest MRI follow up. Two of them were in group 1 and three of them in group 2. Seven patients developed postoperative anterior knee pain. Four of them were in group 1 and three of them in group 2. Only one patient developed both MRI alteration at patellar tendon and anterior knee pain, this patient belongs to group 2. No infections or patellar ruptures were observed. At last follow up four patients had persistent quadricipital hypotrophy, two of them were in group 1 and two in group 2.

Conclusion

CTTP used for ACL reconstruction does not lead to significant complications, disadvantages and radiological alteration in comparison with ACL reconstruction with standard portals.