[Medium- to long-term follow-up after anterior cruciate ligament rupture and repair in healing response technique].

BACKGROUND: Healing response (HR) is an all-arthroscopic technique for treatment of acute proximal anterior cruciate ligament (ACL) tears within 6 weeks after injury. By means of arthroscopically controlled microfracture holes in the native femoral attachment and perforations of the ACL itself the exit of stem cells and growth factors is induced and the ligament can heal into its native attachment zone. The purpose of the study was to document medium- to long-term results after 5 years or longer following the healing response (HR) procedure. The aim of our study was to show that HR is a treatment option for acute proximal ACL tears.

MATERIAL AND METHODS: Between 2004 and 2007 126 patients were treated in healing response technique in our hospital. Patients with a complete proximal ACL tear and operation within 6 weeks of initial injury were included in this study. Patients who had complex knee injuries with multidirectional instability, ACL rerupture, contralateral ACL reconstruction, contralateral ACL rupture or knee replacement and cartilage repair procedures (AMIC, MACT, OATS) were excluded. 43 (23 women/20 men; mean age at time of surgery 36.6 years ± 11.6; range: 16 to 66 years) of 89 eligible patients received clinical follow-up up to 8 years after surgery (mean: 6.3 years). Lysholm score, Tegner activity score, a modified IKDC-2000 knee examination form and an individually created questionnaire were used for evaluation. Furthermore, range of motion, muscle circumference of the lower limb and the anterior tibial translation were measured with a KT-1000 arthrometer™ (MEDmetric® Corporation, San Diego, USA).

RESULTS: 15.1 % of all patients showed a primary insufficiency after HR. 24.6 % of the 126 patients required subsequent ACL reconstruction up to the time of data collection. The 43 patients who received clinical follow-up showed a mean Lysholm score of 92 ± 8.9 points. 72 % reached their original level of activity in the Tegner activity score. According to the IKDC evaluation system 90.7 % of all patients were grade A. 93 % did not show muscles atrophies of the lower limb. There were no limitations in range of motion. Mean side-to-side difference in the KT-1000 manual-maximum displacement test measurements was 1.3 mm ± 1.6 mm. 97.7 % patients had a normal or nearly normal knee function and 86 % rated the overall treatment as good to very good.

CONCLUSION: Patients with good clinical results 6 to 12 weeks after HR show even in the medium- to long-term follow-up good clinical outcomes as well as objective stability. In selected cases HR is an alternative treatment option for acute, proximal ACL ruptures. When indicating an HR procedure, it should be taken into consideration that up to 15 % of all patients could have a primary insufficiency.