Anterior Cruciate Ligament Reconstruction with a Bone-Patellar Tendon-Bone Autograft

Abstract

Polven eturistisiteen korjausleikkaus lumpiojännesiirteellä. 5-9-vuotistulokset 101 potilaalla.

Polven eturistiside on tärkein polven tukevuuteen vaikuttava rakenne. Eturistiside voi vaurioitua esim. urheillessa, jos polveen kohdistuu vääntövamma. Jos vaurioitunutta eturistisidettä ei korjata, on seurauksena polven löysyys, pettämisen tunne ja pitkällä aikavälillä myös polven nivelpintojen rikkoutuminen. Nämä muutokset aiheuttavat polveen kipua ja estävät potilasta liikkumasta samalla lailla kuin ennen. Elämänlaatu siis huononee, jos vaurioitunutta eturistisidettä ei saada kunnolla korjattua.

Tämän tutkimuksen tarkoituksena oli selvittää lumpiojännesiirteellä tehdyn eturistisidekorjauksen pitkäaikaistulokset 101 potilaalla, jotka tutkittiin keskimäärin 7 vuotta korjausleikkauksen jälkeen. Leikkaustulos oli hyvä 80 % potilaista kansainvälisen polvipisteytyksen mukaan arvioituna. Leikattu polvi oli tukeva 98 % potilaista. Sillä ei ollut juurikaan merkitystä, oliko korjausleikkaus tehty heti vamman jälkeen tai vasta myöhemmin. Myöskään se, oliko polvessa muita vammoja (nivelkierukka- tai muita nivelsidevammoja) leikkaushetkellä, ei näyttänyt vaikuttavan lopputulokseen. Noin puolella potilaista oli leikkauksen jälkeen polven etuosan kipua (polvillaan olo oli vaikeaa) ja polvilumpion alaista nivelrikkoa. Polven etuosan kipuun eniten vaikuttava tekijä oli polven ojennusvoiman heikkous; mitä heikompi etureisi oli, sitä enemmän polven etuosassa oli kipua. Polvilumpion alaiseen nivelrikkoon vaikuttivat sekä lumpiojänteen lyhentyminen leikkauksen jälkeen, että eturistisidesiirteen paikka. Jos uusi korjattu eturistiside oli anatomisesti väärässä paikassa, oli myös polvilumpion alainen nivelrikkoriski suurempi kuin anatomisesti oikealla paikalla olevalla siirteellä. Tutkimuksessa kehitimme myös uuden menetelmän, jolla arvioida eturistisidesiirteen paikkaa leikkauksen jälkeen. Uusi menetelmämme näytti olevan parempi kuin aikaisemmat menetelmät, koska se pyrtyi ottamaan huomioon siirteen paikan kokonaisuutena, eikä vain joko siirteen ala- tai yläosaa, kuten aikaisemmat menetelmät.

Anterior Cruciate Ligament Reconstruction with a Bone-Patellar Tendon-Bone Autograft. A Five- to Nine-Year Follow-up of 101 Patients.

The purpose of this study series was to present a long-term result of the anterior cruciate ligament (ACL) reconstruction with a bone-patellar tendon-bone (BTB) autograft with special emphasis on the timing of the reconstruction, and postoperative problems, such as anterior knee pain and patellofemoral osteoarthritis. We also introduced a new method to evaluate the graft placement. In addition, we compared the long-term results of the reconstruction in patients with isolated tear of the ACL to those with an ACL rupture with accompanying injuries. The basic population of the study consisted of the 144 patients who underwent an ACL reconstruction (using the BTB autograft and miniarthrotomy technique) in the Tampere University Hospital between January 1989 and December 1991. Of these 144 patients, 130 (90%) patients could be contacted and interviewed with a questionnaire and 101 (70%) patients (70 men and 31 women) were able to attend the follow-up examination. The mean age of the patients at the time of the operation was 30.5 years (range, 15-61 years). The mean delay between the injury and the reconstruction was 1.7 years (range, 0-20 years), and the mean follow-up time was 6.9 years (range 4.6-8.8 years).

Clinical, functional and radiographic evaluation of the patients was performed using the standard knee ligament evaluation form of the International Knee Documentation Committee (IKDC), and the Lysholm and the Marshall knee scores. Also, the isokinetic muscle torque was measured, and the lengths of the patellar tendon and patella were measured from the lateral radiograph before the reconstruction and at the follow-up. In addition, the lateral radiograph of the knee was used in assessing the tunnels of the graft. The femoral tunnel placement was expressed as a percentage of the entire length of the femoral condyle from posterior-to-anterior along the Blumensaat`s line. The tibial tunnel placement was expressed as a percentage of the anterior-to-posterior length of the tibial plateau. To evaluate both the femoral and tibial tunnel placements simultaneously, we summed up the percentages of the femoral and the tibial tunnel placements thus ending up to a parameter called 'the sum score of the graft placement'.

According to the IKDC rating scale, 80 % of the patients had normal or nearly normal final outcome. The mean (standard deviation) Lysholm score (max. 100 points) was 82 (18) and the mean Marshall score (max. 50 points) was 42 (5), and 98% of the patients had normal or nearly normal stability in the operated knee, as compared to contralateral knee. In none of these outcome parametres, there were significant differences between the early (within 6 weeks after the injury) and late reconstruction (more than 3 months after the injury) groups. However, patients with early reconstruction had less degenerative changes in the tibiofemoral joint, were subjectively more satisfied to the result, and could return to the pre-injury level of sports activities more often than the patients in the late reconstruction group.

About half of the patients had anterior knee pain, as classified by the IKDC. In the logistic regression analysis of predicting factors (forward-stepping), knee extension torque deficit of the operated limb was the only factor that showed significant association with anterior knee pain. Subjectively, the patients without anterior knee pain were more often satisfied with the overall outcome than the patients with anterior knee pain.

Also, the Lysholm and Marshall knee scores and the final outcome in the IKDC rating scale were significantly better in patients without than with anterior knee pain. Also, about half of the patients had patellofemoral osteoarthritis, and the shortening of the patellar tendon correlated to the severity of the patellofemoral osteoarthritis so that greatest shortenings were seen in patients with the most severe osteoarthritic changes. According to the IKDC, Lysholm and Marshall knee rating scales, the patients with patellofemoral osteoarthritis had worse final outcome than the patients without patellofemoral osteoarthritis. The correlation between the sum score of the graft placement and the Lysholm knee score was significant (r= -0.244, p= 0.015), the same concerned the correlation between the sum score of the graft placement and the Marshall knee score (r= -0.244, p= 0.015). This indicated that the sum score of the graft placement was smaller (biomechanically more optimal) in patients with good Lysholm and Marshall knee scores than in patients with poorer knee scores. The sum score of the graft placement was also smaller in patients without patellofemoral osteoarthritis than in patients with patellofemoral osteoarthritis (p=0.033).

The differences between patients with an isolated ACL tear and those with an ACL tear with accompanying injuries were quite small. The final evaluation by the IKDC, and the Lysholm and the Marshall knee scores were similar in both groups, although there were significantly more often subsequent knee operations in the injured knee in the patients with accompanying knee injuries than in the patients with an isolated tear. In conclusion, the stability of the knee was good after an ACL reconstruction with a BTB autograft, and therefore the tibiofemoral osteoarthritis was rare in both patients with early and late reconstruction, as well as those with an isolated tear of the ACL or with an ACL tear with accompanying injuries. However, about half of the patients had anterior knee pain and patellofemoral osteoarthritis with a significant extension strength deficit of the knee. Together these changes impaired the final outcome of the patients. It seems that harvesting of the middle part of the patellar tendon with traditional open technique, and with the closure of the defect with sutures in the patellar tendon, damage the extensor mechanism of the knee by shortening the patellar tendon thus leading to the degenerative changes of the patellofemoral joint. However, the graft placement had also significant correlation to the patellofemoral osteoarthritis, so that the patients with an incorrect placement of the graft had more patellofemoral osteoarthritis than the patients with a good graft placement.