Anterior Closed Wedge High Tibial Osteotomy for Slope Correction in Anterior Cruciate Ligament Insufficiency: A Preliminary Report of 100 Cases at a 2-Year Follow-up

Clinical RelevanceIn recent years, an increased posterior tibial slope has been identified as a nonmodifiable risk factor for anterior cruciate ligament (ACL) injury and increased failure rates after ACL reconstruction (ACLR). To date, the literature consists of clinical case series on slope reducing high tibial osteotomies and reports promising clinical results. However, higher case numbers are still lacking. The goal of the present series of anterior-closed-wedge high tibial osteotomies (ACW-HTO) was to analyze patient-reported outcome measures (PROMs) at a minimum of 2 years. It was hypothesized that an ACW-HTO with secondary ACLR after failed ACL surgery improves clinical outcome as compared with the pre-osteotomy state or can even give sufficient stability to avoid the need for revision ACLR.Material and methodsOne hundred consecutive cases with an ACW-HTO operated between February 2019 and December 2022 were included in 2 surgical centers (57 cases radiographic/51 cases with PROMs Sozialstiftung Bamberg and 43 cases radiographic/35 cases with PROMs Sporthopaedicum Berlin, Germany). The pre-injury (before first injury), the preoperative (before ACW-HTO), and the final postoperative conditions were documented using PROMs.ResultsThe mean follow-up was 36 months (SD ±11, range 24-82), the follow-up rate for the PROMs was 85%. The mean preoperative slope of 14.6° (SD ±2.4°; range 11°-28°), measured according to the method of Dejour and Bonnin, was corrected to a mean of 6.8° (SD ±2.0°; range 0°-12°), P < 0.0001. No relevant complications were noted and no recurrent ACL graft failure was reported within the full follow-up period. Twenty-one patients had not received a revision ACLR after ACW-HTO at final follow-up due to sufficient stability. Prior to the first ACL injury, the mean Tegner activity scale was 7.3 points (SD ±1.7; 3-10) and mean Lysholm score revealed 98 points (SD ±4; range 79-100). Prior to ACW-HTO Tegner Scale was significantly reduced to 3.3 points (SD ±1.8; range 0-9) (P < 0.0001) and Lysholm score revealed 57 points (SD ±28; range 14-94) (P < 0.0001) as compared with the pre-injury level. At final follow-up, mean Tegner activity scale changed to 4.8 points (SD ±1.9; range 0-9), which significantly improved as compared with the pre-osteotomy stage (P < 0.0001). Of 85 patients, 18 achieved their pre-injury Tegner activity level, 2 even reached a level higher than the preoperative level. So the return to pre-injury activity level is 21%. The Lysholm score significantly improved to 83 points. (SD ±18; range 24-100) (P < 0.0001) as compared with the pre-osteotomy stage.ConclusionThe present case series presents the largest published series after ACW-HTO and secondary ACLR. Clinical and radiographic results underline that this procedure is safe and significantly increases the patient's ability to participate in light sports and activities of daily living due to an improved stability. An important fact is that 21% of patients after ACW-HTO have not needed a revision ACLR due to an improvement of stability after the osteotomy.