Osseous valgus alignment and posteromedial ligament complex deficiency lead to increased ACL graft forces
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To biomechanically investigate the influence of osseous valgus alignment, with and without deficiency of the posteromedial ligament complex (PMC), on ACL-graft forces under axial load.
ACL reconstruction was performed on ten cadaveric knee joints. A lateral distal femur osteotomy was then done to adjust for three different alignment conditions according to the position, where the axial weight bearing line (WBL) dissected the tibial plateau (% from medial to lateral): 50%, 85% and 115%. Each alignment was tested with the PMC intact, deficient and reconstructed. Axial loads of 400 N were applied in 15° of knee flexion and changes of ACL-graft forces and dynamic valgus angle (DVA) were recorded.
In the PMC intact state, lateralization of the WBL to 85% and to 115% led to significantly increased ACL graft forces (85%: p = 0.010; 115%: p < 0.001) and DVAs (85%: p = 0.027; 115%: p = 0.027). Dissection of the PMC led to a significant increase of ACL graft forces and DVAs at 85% and 115% valgus alignment (p < 0.001) only.
In comparison to valgus aligned knees with additional PMC deficiency, ligament reconstruction alone was able to significantly decrease ACL graft forces (p < 0.001) and DVAs (p < 0.001). However, alignment correction alone was significantly more effective in reducing ACL graft forces (p < 0.001) and DVAs (p = 0.010).
Osseous valgus alignment led to significantly increased forces on ACL grafts under axial joint compression, which was even further enhanced, when the PMC was deficient. In the valgus aligned and PMC deficient knee, correction to a straight leg axis was significantly more effective in decreasing forces on the ACL graft than reconstruction of the PMC. In patients with valgus alignment and combined injuries of the ACL and PMC, a correction osteotomy to a straight leg axis as well as reconstruction of the PMC should be considered to protect the reconstructed ACL.
KeywordsKnee Valgus Anterior cruciate ligament Instability Medial collateral ligament
All authors contributed to the conception and design of the study. JM, AO, MM and EO were responsible for acquisition of data. JM, CK and FBI contributed to analysis and interpretation of data. All authors were responsible for drafting or revising the article and approved the final version of this manuscript.
The University of Connecticut Health Center/UConn Musculoskeletal Institute has received direct funding and material support from Arthrex (Naples, Fl, USA). The company had no influence on study design, data collection or interpretation of the results or the final manuscript.
Compliance with ethical standards
Conflict of interest
F.B.I. receives funding and study support by Arthrex and speaker fees by medi. A.B.I. is consultant for Arthrosurface and medi and receives royalties from Arthrex and Arthrosurface. R.A.A. receives educational funding by Arthrex and Don-Joy, is consultant for Biorez and has stock options with Biorez. K.B. is consultant for Arthrex. All other authors declare that they have no conflicts of interest.
All specimens were obtained from Science Care (Phoenix, AZ, USA). The study was reported via Human Research Determination Form to the institutional review board (IRB) of the University of Connecticut, Farmington, CT, USA (IRB JM-18-3). It was documented that de-identified specimens do not constitute human subjects research, and no further IRB approval was required.
- 3.Ellsasser JC, Reynolds FC, Omohundro JR (1974) The non-operative treatment of collateral ligament injuries of the knee in professional football players. An analysis of seventy-four injuries treated non-operatively and twenty-four injuries treated surgically. J Bone Jt Surg Am 56:1185–1190CrossRefGoogle Scholar
- 7.Grassi A, Ardern CL, Marcheggiani Muccioli GM, Neri MP, Marcacci M, Zaffagnini S (2016) Does revision ACL reconstruction measure up to primary surgery? A meta-analysis comparing patient-reported and clinician-reported outcomes, and radiographic results. Br J Sports Med 50:716–724CrossRefGoogle Scholar
- 13.Imhoff FB, Mehl J, Comer BJ, Obopilwe E, Cote MP, Feucht MJ et al (2019) Slope-reducing tibial osteotomy decreases ACL-graft forces and anterior tibial translation under axial load. Knee Surg Sports Traumatol Arthrosc 28:019–05360Google Scholar
- 16.LaPrade RF, Engebretsen AH, Ly TV, Johansen S, Wentorf FA, Engebretsen L (2007) The anatomy of the medial part of the knee. J Bone Jt Surg Am 89:2000–2010Google Scholar
- 21.Paley D, Herzenberg JE, Tetsworth K, McKie J, Bhave A (1994) Deformity planning for frontal and sagittal plane corrective osteotomies. Orthop Clin N Am 25:425–465Google Scholar