USE OF GAIT ANALYSIS IN SURGICAL TREATMENT PLANNING FOR PATIENTS WITH CEREBRAL PALSY

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1 USE OF GAIT ANALYSIS IN SURGICAL TREATMENT PLANNING FOR PATIENTS WITH CEREBRAL PALSY Robert M. Kay, M.D. Vice Chief, Children s Orthopaedic Center Children s Hospital Los Angeles Professor, Department of Orthopaedic Surgery Keck-University of Southern California School of Medicine GAIT ANALYSIS a. Objective b. Multilevel and multiplanar II. Impact a. Improved problem identification b. Recommendations vary based on threshold for recommending interventions (e.g. rotational osteotomies) c. Facilitates planning for SEMLS (single event multilevel surgery) III. Outcomes a. Decreased reoperation rate b. Improved outcomes if data are utilized TOE WALKING I. Main causes a. Ankle equinus b. Knee flexion II. Equinus a. Reported in 61% of children with CP presenting to gait lab b. Observers tend to overestimate equinus visually (i.e. we tend to see equinus which is not truly present, which can lead to unnecessary/harmful surgery without gait analysis) c. Poor correlation between static equinus contracture and ankle dorsiflexion in stance i. People with contractures can stretch them out under body weight ii. Others without contractures can have significant dynamic equinus d. Important to make sure: i. Whether equinus is dynamic or due to static contracture ii. Be sure that toe-walking is due to equinus and not due to knee and/or hip flexion (Toe-walking in AFO s is a tip-off that knee/hip are problems) e. Avoid surgery whenever possible (by using stretching, braces, serial casting ) i. Heelcords are better a little tight than a little loose ii. Calcaneus reported in up to 30-36% of patients following Achilles lengthening surgery f. Surgery i. Silfverskiöld test to determine whether both soleus and gastrocnemius are both tight 1. If cannot dorsiflex adequately with knee flexed, then soleus is also tight PEARLS: 1. Toe-walking in AFO s implicates the hamstrings (and/or hip flexors). 2. Heelcords are better a little too tight than too loose. 3. Excessive dorsiflexion is common after heelcord surgery.

2 PES VARUS a. Compromises stability in stance b. Common gait deviation in CP i. Much more common in unilateral CP II. Contributors a. Anterior tibialis ~ 1/3 of cases b. Posterior tibialis ~ 1/3 c. Anterior & Posterior tibialis ~ 1/3 i. Differentiate between flexible and rigid deformities ii. Surgery 1. Balance soft tissues 2. Bony surgery also needed for rigid deformity III. Surgery a. Soft tissue i. Anterior tibialis: Split anterior tibial tendon transfer (SPLATT) ii. Posterior tibialis: Split transfer or lengthening b. Osseous (if deformity rigid) i. Calcaneal osteotomy (Dwyer) PEARLS: 1. Anterior tibialis is a significant contributor to varus feet in children with CP, contrary to traditional teaching. 2. Soft tissues need to be balanced to minimize the risk of recurrence. 3. Calcaneal osteotomy needed for rigid deformity. LEVER ARM DYSFUNCTION a. Moment = Force x Distance ( Lever arm is the perpendicular distance from force to the center of rotation) b. Lever arm dysfunction can be caused by a number of abnormalities (e.g. a short lever, nonrigid lever, malrotated lever ) 2

3 Images from Rethlefsen SA, Kay RM: Transverse plane gait problems in children with CP. J Pediatr Orthop 33: , 2013 c. Lever arm is not a significant problem in typically developing children due to typical balance, strength and coordination II. Examples in CP a. GRF ends up behind knee in children with CP due to crouch and lever arm dysfunction i. Long bone torsion ii. Pes valgus b. Short lever for hip abductors c. Unstable fulcrum for hip abductors due to subluxating hip III. Treatment a. Restore lever arms to maximize function in children with CP i. Operative long bone osteotomies, pes valgus correction, hip stabilization ii. Non-operative braces in pes valgus PEARL: Bony malalignment is more problematic in children with CP (or other neuromuscular disorders) due to limitations in balance, strength and coordination. INTOEING a. Results in lever arm dysfunction b. Causes in CP i. Femoral torsion ii. Tibial torsion iii. Varus foot common in bilateral, rare in unilateral CP iv. Internal pelvic rotation v. Metatarsus adductus II. Gait analysis a. Look at both knee progression angle (KPA) and foot progression angle (FPA) b. If KPA is internal, there is a problem above the knee (hip and/or pelvic internal rotation) 3

4 c. If KPA is neutral, hip rotation is likely OK, though sometimes may be neutral if pelvic rotation and hip rotation are in opposite directions d. If FPA is more internal than KPA, there is a problem below the knee (usually tibial torsion and/or varus foot) III. Treatment a. Non-operative i. Twister cables, etc. do NOT change natural history of transverse plane alignment of the legs 1. Twister cables can buy time while awaiting surgery b. Operative i. Long bone osteotomy 1. Femoral osteotomy a. Comparable results for proximal and distal osteotomies i. Distal osteotomy 1. Smaller incision 2. Less dissection 3. Can remove pins in office 1 month post-op ii. Proximal osteotomy 1. indicated for hip subluxation or skeletal maturity 2. More rigid fixation, but later surgery to remove plate b. Surgical correction should be 1.5 2:1 of what is deemed necessary clinically. ii. Tibial osteotomy 1. Distal osteotomy is much safer than proximal osteotomy a. Can remove pins in office 3-4 weeks post-op 2. Fibular osteotomy is almost never needed for rotational osteotomy 3. Surgical correction should be 1:1 of what is deemed necessary clinically. iii. Varus foot correction (see pes varus section) PEARLS: 1. Femoral osteotomies have comparable results when done proximally or distally, whereas tibial osteotomies are best done distally. 2. Surgical correction should be 1.5 2:1 for femoral osteotomies and 1:1 for tibial osteotomies. CROUCH GAIT a. Common in CP b. Frequency increases with age II. Treatment a. Non-operative i. Hamstring stretching/quad strengthening ii. Knee immobilizers iii. Botulinum toxin (typically combine with knee immobilizers at night) b. Operative contracture/knee contractures i. Surgery 1. Hamstring lengthening a. Avoid overlengthening (results in recurvatum and stiff-knee in swing and is hard to overcome) b. Recurvatum more common with medial/lateral lengthening than with isolated lateral lengthening (24% vs 6% in one study) c. Results worse with revision HSL 4

5 d. Neuropraxia in up to 10% of patients i. Risk increased with epidural anesthesia ii. Do NOT check a popliteal angle intra-op to minimize tension on peroneal nerve 2. Guided growth a. Consider in adolescents with knee flexion contractures 10-15⁰ and open growth plates 3. Distal femoral extension osteotomy (typically with patellar tendon shortening/advancement) i. Consider in adolescents with flexion contractures 20⁰ ii. May be done before or after skeletal maturity iii. Results are best in conjunction with patellar tendon shortening/advancement surgery PEARLS: 1. Overlengthening of hamstrings is an under-appreciated problem with aggressive hamstring lengthening, and results in recurvatum and stiff-knee gait. 2. Lateral hamstrings often do not require lengthening, particularly in pre-adolescents. 3. Results of repeat hamstring lengthening are inferior to primary surgery. 4. Results of distal femoral extension osteotomies are better when combined with soft tissue surgery to address patella alta. SELECTED REFERENCES Borton, D. C.; Walker, K.; Pirpiris, M.; Nattrass, G. R.; and Graham, H. K.: Isolated calf lengthening in cerebral palsy. Outcome analysis of risk factors. J Bone Joint Surg Br. 2001, 83(3): Chambers, H.; Lauer, A.; Kaufman, K.; Cardelia, J. M.; and Sutherland, D.: Prediction of outcome after rectus femoris surgery in cerebral palsy: the role of cocontraction of the rectus femoris and vastus lateralis. J Pediatr Orthop. 1998, 18(6): DeLuca, P. A.; Davis, R. B., 3rd; Ounpuu, S.; Rose, S.; and Sirkin, R.: Alterations in surgical decision making in patients with cerebral palsy based on three-dimensional gait analysis. J Pediatr Orthop. 1997, 17(5): Dietz, F. R.; Albright, J. C.; and Dolan, L.: Medium-term follow-up of Achilles tendon lengthening in the treatment of ankle equinus in cerebral palsy. Iowa Orthop J. 2006, 26: Dreher, T.; Buccoliero, T.; Wolf, S. I.; Heitzmann, D.; Gantz, S.; Braatz, F.; and Wenz, W.: Long-term results after gastrocnemius-soleus intramuscular aponeurotic recession as a part of multilevel surgery in spastic diplegic cerebral palsy. J Bone Joint Surg Am. 2012, 94(7): Dreher, T.; Vegvari, D.; Wolf, S. I.; Geisbusch, A.; Gantz, S.; Wenz, W.; and Braatz, F.: Development of knee function after hamstring lengthening as a part of multilevel surgery in children with spastic diplegia: a longterm outcome study. J Bone Joint Surg Am. 2012, 94(2): Firth, G. B.; Passmore, E.; Sangeux, M.; Thomason, P.; Rodda, J.; Donath, S.; Selber, P.; and Graham, H. K.: Multilevel surgery for equinus gait in children with spastic diplegic cerebral palsy: medium-term follow-up with gait analysis. J Bone Joint Surg Am. 2013, 95(10): Gage, J. R.: Surgical treatment of knee dysfunction in cerebral palsy. Clin Orthop Relat Res. 1990(253): Gage, J. R.; Perry, J.; Hicks, R. R.; Koop, S.; and Werntz, J. R.: Rectus femoris transfer to improve knee function of children with cerebral palsy. Dev Med Child Neurol. 1987, 29(2): Gage, J. R., and Schwartz, M.: Pathological Gait and Lever-Arm Dysfunction. In The Treatment of Gait Problems in Cerebral Palsy, pp Edited by Gage, J. R., , London, Mac Keith Press, Graham, H. K.: Classifying cerebral palsy. J Pediatr Orthop. 2005, 25(1): Huh, K.; Rethlefsen, S. A.; Wren, T. A.; and Kay, R. M.: Development of calcaneal gait without prior triceps surae lengthening: an examination of predictive factors. J Pediatr Orthop. 2010, 30(3):

6 13. Kay, R. M.; Dennis, S.; Rethlefsen, S.; Reynolds, R. A.; Skaggs, D. L.; and Tolo, V. T.: The effect of preoperative gait analysis on orthopaedic decision making. Clin Orthop Relat Res. 2000(372): Kay, R. M.; Dennis, S.; Rethlefsen, S.; Skaggs, D. L.; and Tolo, V. T.: Impact of postoperative gait analysis on orthopaedic care. Clin Orthop Relat Res. 2000(374): Kay, R. M.; Rethlefsen, S. A.; Fern-Buneo, A.; Wren, T. A.; and Skaggs, D. L.: Botulinum toxin as an adjunct to serial casting treatment in children with cerebral palsy. J Bone Joint Surg Am. 2004, 86-A(11): Kay, R. M.; Rethlefsen, S. A.; Hale, J. M.; Skaggs, D. L.; and Tolo, V. T.: Comparison of proximal and distal rotational femoral osteotomy in children with cerebral palsy. J Pediatr Orthop. 2003, 23(2): Kay, R. M.; Rethlefsen, S. A.; Ryan, J. A.; and Wren, T. A.: Outcome of gastrocnemius recession and tendoachilles lengthening in ambulatory children with cerebral palsy. J Pediatr Orthop B. 2004, 13(2): Kay, R. M.; Rethlefsen, S. A.; Skaggs, D.; and Leet, A.: Outcome of medial versus combined medial and lateral hamstring lengthening surgery in cerebral palsy. J Pediatr Orthop. 2002, 22(2): Kerr Graham, H., and Selber, P.: Local and distant effects of isolated calf muscle lengthening in children with cerebral palsy and equinus gait. Lofterod B, Terjesen T. Journal of Children's Orthopaedics 2008;1: J Child Orthop. 2008, 2(4): Klatt, J., and Stevens, P. M.: Guided growth for fixed knee flexion deformity. J Pediatr Orthop. 2008, 28(6): Michlitsch, M. G.; Rethlefsen, S. A.; and Kay, R. M.: The contributions of anterior and posterior tibialis dysfunction to varus foot deformity in patients with cerebral palsy. J Bone Joint Surg Am. 2006, 88(8): Novacheck, T. F.; Stout, J. L.; Gage, J. R.; and Schwartz, M. H.: Distal femoral extension osteotomy and patellar tendon advancement to treat persistent crouch gait in cerebral palsy. Surgical technique. J Bone Joint Surg Am. 2009, 91 Suppl 2: Ounpuu, S.; DeLuca, P.; Davis, R.; and Romness, M.: Long-term effects of femoral derotation osteotomies: an evaluation using three-dimensional gait analysis. J Pediatr Orthop. 2002, 22(2): Ounpuu, S.; Muik, E.; Davis, R. B., 3rd; Gage, J. R.; and DeLuca, P. A.: Rectus femoris surgery in children with cerebral palsy. Part II: A comparison between the effect of transfer and release of the distal rectus femoris on knee motion. J Pediatr Orthop. 1993, 13(3): Ounpuu, S.; Muik, E.; Davis, R. B., 3rd; Gage, J. R.; and DeLuca, P. A.: Rectus femoris surgery in children with cerebral palsy. Part I: The effect of rectus femoris transfer location on knee motion. J Pediatr Orthop. 1993, 13(3): Rethlefsen, S.; Tolo, V. T.; Reynolds, R. A.; and Kay, R.: Outcome of hamstring lengthening and distal rectus femoris transfer surgery. J Pediatr Orthop B. 1999, 8(2): Rethlefsen, S. A.; Kam, G.; Wren, T. A.; and Kay, R. M.: Predictors of outcome of distal rectus femoris transfer surgery in ambulatory children with cerebral palsy. J Pediatr Orthop B. 2009, 18(2): Rethlefsen, S. A., and Kay, R. M.: "Kinematic and kinetic evaluation of the ankle joint before and after tendo Achilles lengthening in patients with spastic diplegia". J Pediatr Orthop. 2008, 28(3): Rethlefsen, S. A., and Kay, R. M.: Transverse plane gait problems in children with cerebral palsy. J Pediatr Orthop. 2013, 33(4): Rethlefsen, S. A.; Yasmeh, S.; Wren, T. A.; and Kay, R. M.: Repeat hamstring lengthening for crouch gait in children with cerebral palsy. J Pediatr Orthop. 2013, 33(5): Sangeorzan, B. J.; Mosca, V.; and Hansen, S. T., Jr.: Effect of calcaneal lengthening on relationships among the hindfoot, midfoot, and forefoot. Foot Ankle. 1993, 14(3): Saraph, V.; Zwick, E. B.; Auner, C.; Schneider, F.; Steinwender, G.; and Linhart, W.: Gait improvement surgery in diplegic children: how long do the improvements last? J Pediatr Orthop. 2005, 25(3): Segal, L. S.; Thomas, S. E.; Mazur, J. M.; and Mauterer, M.: Calcaneal gait in spastic diplegia after heel cord lengthening: a study with gait analysis. J Pediatr Orthop. 1989, 9(6): Skaggs, D. L.; Rethlefsen, S. A.; Kay, R. M.; Dennis, S. W.; Reynolds, R. A.; and Tolo, V. T.: Variability in gait analysis interpretation. J Pediatr Orthop. 2000, 20(6): Stevens, P. M., and Novais, E. N.: Multilevel guided growth for hip and knee varus secondary to chondrodysplasia. J Pediatr Orthop. 2012, 32(6): Stout, J. L.; Gage, J. R.; Schwartz, M. H.; and Novacheck, T. F.: Distal femoral extension osteotomy and patellar tendon advancement to treat persistent crouch gait in cerebral palsy. J Bone Joint Surg Am. 2008, 90(11):

7 37. Sutherland, D. H.; Santi, M.; and Abel, M. F.: Treatment of stiff-knee gait in cerebral palsy: a comparison by gait analysis of distal rectus femoris transfer versus proximal rectus release. J Pediatr Orthop. 1990, 10(4): Thomason, P.; Baker, R.; Dodd, K.; Taylor, N.; Selber, P.; Wolfe, R.; and Graham, H. K.: Single-event multilevel surgery in children with spastic diplegia: a pilot randomized controlled trial. J Bone Joint Surg Am. 2011, 93(5): Thomason, P.; Selber, P.; and Graham, H. K.: Single Event Multilevel Surgery in children with bilateral spastic cerebral palsy: a 5 year prospective cohort study. Gait Posture. 2013, 37(1): Westwell, M.; Ounpuu, S.; and DeLuca, P.: Effects of orthopedic intervention in adolescents and young adults with cerebral palsy. Gait Posture. 2009, 30(2): Wren, T. A.; Cheatwood, A. P.; Rethlefsen, S. A.; Hara, R.; Perez, F. J.; and Kay, R. M.: Achilles tendon length and medial gastrocnemius architecture in children with cerebral palsy and equinus gait. J Pediatr Orthop. 2010, 30(5): Wren, T. A.; Do, K. P.; Hara, R.; Dorey, F. J.; Kay, R. M.; and Otsuka, N. Y.: Gillette Gait Index as a gait analysis summary measure: comparison with qualitative visual assessments of overall gait. J Pediatr Orthop. 2007, 27(7): Wren, T. A.; Do, K. P.; and Kay, R. M.: Gastrocnemius and soleus lengths in cerebral palsy equinus gait-- differences between children with and without static contracture and effects of gastrocnemius recession. J Biomech. 2004, 37(9): Wren, T. A.; Elihu, K. J.; Mansour, S.; Rethlefsen, S. A.; Ryan, D. D.; Smith, M. L.; and Kay, R. M.: Differences in implementation of gait analysis recommendations based on affiliation with a gait laboratory. Gait Posture. 2013, 37(2): Wren, T. A.; Gorton, G. E., 3rd; Ounpuu, S.; and Tucker, C. A.: Efficacy of clinical gait analysis: A systematic review. Gait Posture. 2011, 34(2): Wren, T. A.; Kalisvaart, M. M.; Ghatan, C. E.; Rethlefsen, S. A.; Hara, R.; Sheng, M.; Chan, L. S.; and Kay, R. M.: Effects of preoperative gait analysis on costs and amount of surgery. J Pediatr Orthop. 2009, 29(6): Wren, T. A.; Lening, C.; Rethlefsen, S. A.; and Kay, R. M.: Impact of gait analysis on correction of excessive hip internal rotation in ambulatory children with cerebral palsy: a randomized controlled trial. Dev Med Child Neurol Wren, T. A. et al.: Outcomes of lower extremity orthopedic surgery in ambulatory children with cerebral palsy with and without gait analysis: Results of a randomized controlled trial. Gait Posture. 2013, 38(2): Wren, T. A.; Rethlefsen, S.; and Kay, R. M.: Prevalence of specific gait abnormalities in children with cerebral palsy: influence of cerebral palsy subtype, age, and previous surgery. J Pediatr Orthop. 2005, 25(1): Wren, T. A.; Rethlefsen, S. A.; Healy, B. S.; Do, K. P.; Dennis, S. W.; and Kay, R. M.: Reliability and validity of visual assessments of gait using a modified physician rating scale for crouch and foot contact. J Pediatr Orthop. 2005, 25(5): Wren, T. A.; Woolf, K.; and Kay, R. M.: How closely do surgeons follow gait analysis recommendations and why? J Pediatr Orthop B. 2005, 14(3):