Objective To explore the clinical,radiological,and arthroscopic outcomes of anterior cru-ciate ligament(ACL)reconstruction combined with posterior tibial slope(PTS)reducing osteotomy in patients with increased PTS and excessive anterior tibial subluxation(ATS)due to primary ACL inju-ry.Methods This retrospective study included patients who underwent ACL reconstruction between 2016 and 2022 in our department.The inclusion criteria were PTS≥15° and ATS≥6 mm,and all pa-tients received ACL reconstruction combined with PTS reducing osteotomy with a follow-up of more than 2 years.Before and after the operation,they were assessed KT-1000 side-to-side difference(KT SSD),pivot shift grade,Lachman test,anterior tibial subluxation of the medial and lateral compart-ments(ASMC and ASLC),magnetic resonance imaging(MRI),and arthroscopic findings of associat-ed injuries.Moreover,graft laxity was defined as graft laxity observed on MRI or arthroscopy,KT SSD>3 mm,or pivot>1+,while graft failure was defined as graft rupture on MRI or arthroscopy,KT SSD>5 mm,or pivot>2+.Meanwhile,clinical outcomes were compared preoperatively and post-operatively,and graft status and associated injuries were described.Results A total of 30 patients were included,with an average age of 31 years,and 23%of female.The inter-observer reliability for mea-surements of PTS and ATS was greater than 0.80.Compared to preoperative values,postoperative PTS(18.2° vs.6.8°,P<0.001),KT SSD(7.8 mm vs.1.2 mm,P<0.001),ASLC(7.5 mm vs.4.5 mm,P=0.002),and ASMC(5.0 mm vs.2.7 mm,P=0.034),all showed significant improvements.In addi-tion,the proportion of patients with postoperative pivot grade of 2+to 3+(73.3%vs.6.7%,P<0.001)and Lachman grades Ⅱ-Ⅲ(70%vs.3.3%,P<0.001)reduced significantly.At the last follow-up,the incidence of graft laxity was 20%,and that of the graft failure was 13.3%.Among all pa-tients,1 patient(3.3%)had graft roof impingement or cyclops lesion,and 3(10%)suffered from concomitant cartilage injury,with 4(13.3%)undergoing intercondylar notchplasty due to intercondylar notch hyperplasia.However,no complications related to osteotomy,such as infection,non-union,or fixation failure,were observed.Conclusion Over a follow-up period of at least 2 years,for primary ACL injury patients with steep PTS and excessive ATS,combined ACL reconstruction with PTS reduc-ing osteotomy improves knee stability,but significantly reduces PTS,the incidence of severe pivot grade,anterior tibial subluxation in both medial and lateral compartments,and delays the occurrence of graft laxity and failure.

Objective To explore the clinical,radiological,and arthroscopic outcomes of anterior cru-ciate ligament(ACL)reconstruction combined with posterior tibial slope(PTS)reducing osteotomy in patients with increased PTS and excessive anterior tibial subluxation(ATS)due to primary ACL inju-ry.Methods This retrospective study included patients who underwent ACL reconstruction between 2016 and 2022 in our department.The inclusion criteria were PTS≥15° and ATS≥6 mm,and all pa-tients received ACL reconstruction combined with PTS reducing osteotomy with a follow-up of more than 2 years.Before and after the operation,they were assessed KT-1000 side-to-side difference(KT SSD),pivot shift grade,Lachman test,anterior tibial subluxation of the medial and lateral compart-ments(ASMC and ASLC),magnetic resonance imaging(MRI),and arthroscopic findings of associat-ed injuries.Moreover,graft laxity was defined as graft laxity observed on MRI or arthroscopy,KT SSD>3 mm,or pivot>1+,while graft failure was defined as graft rupture on MRI or arthroscopy,KT SSD>5 mm,or pivot>2+.Meanwhile,clinical outcomes were compared preoperatively and post-operatively,and graft status and associated injuries were described.Results A total of 30 patients were included,with an average age of 31 years,and 23%of female.The inter-observer reliability for mea-surements of PTS and ATS was greater than 0.80.Compared to preoperative values,postoperative PTS(18.2° vs.6.8°,P<0.001),KT SSD(7.8 mm vs.1.2 mm,P<0.001),ASLC(7.5 mm vs.4.5 mm,P=0.002),and ASMC(5.0 mm vs.2.7 mm,P=0.034),all showed significant improvements.In addi-tion,the proportion of patients with postoperative pivot grade of 2+to 3+(73.3%vs.6.7%,P<0.001)and Lachman grades Ⅱ-Ⅲ(70%vs.3.3%,P<0.001)reduced significantly.At the last follow-up,the incidence of graft laxity was 20%,and that of the graft failure was 13.3%.Among all pa-tients,1 patient(3.3%)had graft roof impingement or cyclops lesion,and 3(10%)suffered from concomitant cartilage injury,with 4(13.3%)undergoing intercondylar notchplasty due to intercondylar notch hyperplasia.However,no complications related to osteotomy,such as infection,non-union,or fixation failure,were observed.Conclusion Over a follow-up period of at least 2 years,for primary ACL injury patients with steep PTS and excessive ATS,combined ACL reconstruction with PTS reduc-ing osteotomy improves knee stability,but significantly reduces PTS,the incidence of severe pivot grade,anterior tibial subluxation in both medial and lateral compartments,and delays the occurrence of graft laxity and failure.