HTO Complication M. Moghtadaei MD Associate Professor Iran University of Medical Sciences

Complication MOW,LCW,Dome,… –Over/Under correction –Joint line obliquity –Fracture –Nonunion –PF complications –Peroneal Nerve Palsy –Compartment Syndrome –Infection –Thromboembolism

COMPLICATION % ( 15.2 % ) smaller osteotomy gap size lower complication rate 10 mm is the threshold for most authors Nelissen EM, Langelaan EJ, Nelissen RGHH (2010) Int Orthop 34:217–223 Miller BS, Downie B, McDonough EB, Wojtys EM (2009) Arthroscopy 25:639–646

Over/Under correction Medial compartment load : 0 degree  70% 4 degree valgus  50% 6 degree valgus  40% recommended alignment degree valgus or mechanical axis pass through % lateral to the midpoint of the knee

Over/Under correction Overcorrection to a valgus position might negatively influence the patients’ sport-specific and leisure activity levels 33

Recurrence of deformity Long-term studies –clinical success deteriorates with time –60% of patients at 10 years follow up Overcorrection

FRACTURES Medial or lateral cortex the proximal fragment may be destabilized Fractures must be appropriately reduced and stabilized

FRACTURES In articular surface is more severe complication because of resultant articular incongruity During both LCW and MOW

FRACTURES apex of osteotomy within 10 mm of the far cortex Leaving the proximal fragment at least 15mm thick gradual closure or opening of the osteotomy permits stress relaxation of the intact far cortex 15 mm 10 mm

FRACTURES

drill hole at the apex of the osteotomy increases the amount of correction obtained before cortical fracture Kessler OC, Jacob HA, Romero J: Clin Orthop 2002;395:

fluoroscopy

NONUNION % ( 2.2 % )

a better understanding of PFJ pressures and forces is important in long-term results Patellofemoral effect

Increased contact pressures an important factor in degeneration of articular cartilage Outerbridge RE.. J Bone Joint Surg Br. 1961;43: Skyhar MJ, Warren RF, Ortiz GJ, Schwartz E, Otis JC. J Bone Joint Surg Am. 1993;75:

effects of HTO on PFJ –contact pressure –alteration of patellar height –PFJ tracking Stoffel K, Willers C, Korshid O, Kuster M. KneeSurg Sports Traumatol Arthrosc. 2007;15: Gaasbeek RD, Sonneveld H, van Heerwaarden RJ, Jacobs WC,Wymenga AB. Knee.2004;11: Kaper BP, Bourne RB, Rorabeck CH, Macdonald SJ. J Arthroplasty. 2001;16: Tigani D, Ferrari D, Trentani P, Barbanti-Brodano G, Trentani F. Int Orthop. 2001;24: Wright JM, Heavrin B, Begg M, Sakyrd G, Sterett W. Am J Knee Surg. 2001;14: Moghtadaei M. et al, IRCMJ, 2014 Patellofemoral effect

Contact Pressure MOW higher pressures in PFJ at different flexion angles increasing contact pressures with increasing angle of correction with MOW Huberti HH, Hayes WC. J Bone Joint Surg Am.1984;66: Singerman R, Davy DT, Goldberg VM. J Biomech.1994;27:

Contact Pressure increased pressure further degeneration in an already painful, degenerative joint unsatisfactory clinical scores due to unresolved pain knowing how an HTO affects retropatellar pressures is a crucial step in decision making

Contact Pressure in symptomatic PF arthritis –HTO is abandoned in favor of TKA –combined with anterior (Maquet) or anteromedial (Fulkerson) transfer of the tibial tubercle Am J of Sport Med.;2013 Jan;41(1):80-6

Patellar Height LCW high incidence of patella baja A common misconception –patella baja because of rearrangement in osseous architecture following wedge removal results from contracture of patellar tendon Cast immobilization can be eliminated by rigid IF and aggressive mobilization Scuderi GR,Windsor RE, Insall JN: J Bone Joint Surg Am 1989;71: Westrich GH, Peters LE, Haas SB, Buly RL, Windsor RE: Clin Orthop 1998;354:

Patellar Height changes in osseous architecture after LCW increase patellar height Wright JM, Heavrin B, Begg M, Sakyrd G, Sterett W: Am J Knee Surg2001;14:

Patellar Height MOW lowers patellar height by raising the TFJ line 64% incidence of patella baja raises concerns regarding potential adverse impact on PF biomechanics Wright JM, Heavrin B, Begg M, Sakyrd G, Sterett W: Am J Knee Surg2001;14:

Patellar Height Multiple studies documented patella infera following a MOW HTO increased retropatellar pressure and contact forces risk of knee pain and reduced ROM Gaasbeek RD, Sonneveld H, van Heerwaarden RJ, Jacobs WC,Wymenga AB. Knee.2004;11: Scuderi GR,Windsor RE, Insall JN: J Bone Joint Surg Am 1989;71: Stoffel K, Willers C, Korshid O, Kuster M. KneeSurg Sports Traumatol Arthrosc. 2007;15: Kaper BP, Bourne RB, Rorabeck CH, Macdonald SJ. J Arthroplasty. 2001;16: Stoffel K, Willers C, Korshid O, Kuster M. KneeSurg Sports Traumatol Arthrosc. 2007;15:

importance of considering PF arthritis and degeneration when an HTO is attempted

minimal disturbance of the patellar height minimally increased retropatellar pressures Stoffel K, Willers C, Korshid O, Kuster M. KneeSurg Sports Traumatol Arthrosc. 2007;15:

PFJ Tracking After MOW HTO –patella was lowered and tibia slope increased –patellar tilt and shift do not significantly change Yang JH, Lee SH, Nathawat KS,Jeon SH, Oh KJ. Knee ;2013 Mar;20(2):128-32

PFJ Tracking 43 patients open wedge HTO CT Scan –Congruence Angle,TT-TG before and after surgery Not significantly different(P > 0.05) Moghtadaei M. et al, IRCMJ, 2014

INFECTION 0.8 % % Superficial deep debridement and antibiotics If septic implant removal and use of external fixator

THROMBOEMBOLIC EVENTS DVT : % = joint replacement Thromboprophylaxis similar to Knee arthroplasty

NERVE INJURY Peroneal % Fibular osteotomy in LCW Postop may be related to increased pressure in anterior compartment

Vascular Injury must monitor for vascular injury –letting down the tourniquet if necessary a vascular surgeon must be available Some injuries may be detected postoperatively –Pseudoaneurysm

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