ORTHOPAEDIC SURGERY FOR THE LOWER LIMBS IN CHILDREN WITH CEREBRAL PALSY

Transcription

1 ORTHOPAEDIC SURGERY FOR THE LOWER LIMBS IN CHILDREN WITH CEREBRAL PALSY Robert M. Kay, M.D. Vice Chief, Children s Orthopaedic Center Children s Hospital Los Angeles Professor, Orthopaedic Surgery Keck- University of Southern California School of Medicine GENERAL I. Treatment a. Goals i. Maximize function ii. Delay/avoid surgery when possible b. Optimizing outcome requires optimizing biomechanical alignment in all planes i. Remember: all joints affect all other joints in all planes c. Non- surgical treatments i. Bracing ii. Stretching iii. Botulinum toxin (off label indication) iv. Bracing d. Operative intervention i. The decision is more important than the incision - - Mercer Rang ii. Typical indications 1. Age: 7 10 years 2. Wait until child has plateaued for 6-8 months 3. Non- operative interventions will not suffice to address the problems iii. Single event multilevel surgery (SEMLS), addressing all bone and soft tissues at one time, is the standard of care 1. Gait analysis is performed pre- op, when available a. Optimizes outcome b. Decreases rate of reoperation 1. All significantly affected planes and levels should be addressed with SEMLS. 2. Pre- operative decision- making is the most important determinant of surgical outcome. 3. Pre- operative gait analysis decreases rates of reoperation and cost in children with CP.

2 SOFT TISSUE PROBLEMS I. Hip flexion contractures a. As with other contractures, static and dynamic measures often not well correlated i. 50% with HFC > 10, do not walk with excessive hip flexion (Rethlefsen et al. J Pediatr Orthop 2010) b. Main problem is crouch, though crouch is often seen in the absence of hip flexion contracture (HFC) c. Consider surgery (psoas recession) if HFC >10 degrees and significant hip flexion in stance i. May do this through adductor incision if adductors require lengthening 1. Many patients who walk with excessive hip flexion do not have HFC. 2. Many with HFC do not have severe hip flexion during gait. II. Hip adduction contractures a. Problems i. Scissoring ii. Troubles with diapering & hygiene b. Differentiate between dynamic scissoring and fixed contracture c. When surgery necessary, the adductor longus is typically tightest. i. Try to avoid lengthening brevis and magnus. (These rarely need lengthening, especially in ambulatory children) ii. Obturator neurectomy should be avoided (to avoid frog positioning of hips) PEARL: Obturator neurectomy has risk of causing abduction contractures, and does not decrease the risk of recurrent subluxation when combined with bony procedures III. Knee problems a. Hamstring contracture/knee contractures i. Flexion contractures are much more common than extension contractures (exception: near drowning survivors) ii. Problems 1. Crouch 2. Difficulty sitting is rare for knee flexion contracture < 90, but common with knee extension contracture iii. Treatment 1. Conservative: stretching, knee immobilizers, botulinum toxin 2. Surgery a. Hamstring lengthening (HSL) i. Avoid overlengthening (results in recurvatum) ii. Recurvatum more common with medial/lateral lengthening than isolated medial lengthening 2

3 b. Guided growth (anterior hemiepiphysiodesis of distal femur) for knee contractures if > ~ 2 years of remaining growth c. Distal femoral extension osteotomy (for more severe deformities and/or less growth remaining) i. Better results when combined with patellar tendon advancement (PTA) 3. Peri- op issues a. Neuropraxia risk increased with epidural anesthesia b. Do NOT check a popliteal angle intra- op 1. Overlengthening of hamstrings is an under- appreciated problem and results in genu recurvatum and stiff- knee gait. 2. Lateral hamstrings often do not require lengthening, particularly before adolescents. 3. Consider bone surgery for recurrent and/or severe contractures b. Stiff- knee gait i. Interferes with foot clearance in swing phase ii. Often due to rectus spasticity iii. Consider surgery (distal rectus femoris transfer) if following criteria are met: 1. Excursion from stance to swing < EMG shows rectus is overactive in swing phase 3. GMFCS I and II IV. Ankle/Foot problems a. Equinus i. Important to make sure: 1. Whether equinus is dynamic or due to static contracture 2. Be sure that toe- walking is due to equinus and not knee and/or hip flexion a. Toe- walking in AFO s is a tip- off that knee/hip are issues ii. Avoid surgery whenever possible (by using stretching, braces, serial casting ) 1. Heelcords are better a little tight than a little loose 2. Calcaneus gait more common with age (even without previous heelcord surgery) 3. Calcaneus reported in up to 30-40% of patients following heelcord surgery a. Rate much lower with gastroc recession than TAL 1. Toe- walking in AFO s implicates the hamstrings. 2. Heelcords are better a little too tight than too loose. 3

4 b. Varus i. Contributors 1. Anterior tibialis ~ 1/3 of cases 2. Posterior tibialis ~ 1/3 3. Anterior & Posterior tibialis ~ 1/3 ii. Differentiate between flexible and rigid deformities iii. Surgery 1. Balance soft tissues 2. Bony surgery also needed for rigid deformity 1. Anterior tibialis is a significant contributor to varus feet in children with CP, contrary to traditional teaching. 2. Always balance soft tissues, regardless of whether deformity is flexible or rigid c. Valgus i. Differentiate pes valgus from ankle valgus 1. Clinical exam 2. X- ray, if suspicious of ankle valgus ii. Often associated with tight gastrocnemius and peroneals iii. If surgery indicated, calcaneal osteotomies preserve hindfoot motion (either calcaneal lengthening or slide) iv. Talonavicular fusion may be needed for significant midfoot breaks PEARL: 1. Make sure that valgus is from the foot and not the ankle (standing AP ankle x- ray may be needed). 2. If the valgus is from the ankle, address the tibia with hemiepiphysiodesis or osteotomy. SOFT TISSUE PROBLEMS I. Lever arm dysfunction a. Problematic in children with CP due to lack of typical balance, strength and coordination b. Surgery may be needed to address lever arm dysfunction due to torsional deformity, foot deformity and/or hip subluxation 4

5 From: Rethlefsen SA, Kay RM. J Pediatr Orthop II. Long bone torsion (femur and/or tibia) a. Consider osteotomy if torsion persists and interferes with function b. Femoral osteotomy i. Comparable results for proximal and distal osteotomies ii. Proximal osteotomy indicated if: 1. Coxa valga 2. Hip subluxation iii. Surgical correction should be 1.5 2:1 of what is deemed clinically c. Tibial osteotomy i. Distal osteotomy is much safer than proximal osteotomy ii. Fibular osteotomy is not needed for rotational correction iii. Surgical correction should be 1:1 PEARLS 1. Bony malalignment is more problematic in children with CP due to limitations in balance, strength and coordination. 2. Proximal and distal femoral osteotomies have equivalent results. 3. Tibial osteotomies are best done distally. 5

6 4. Surgical correction should be 1.5 2:1 for femoral osteotomies and 1:1 for tibial osteotomies. REFERENCES 1. 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): Gage, J. R.: Specific Problems of the Hips, Knees and Ankles. In The Treatment of Gait Problems in Cerebral Palsy, pp Edited by Gage, J. R., , London Mac Keith Press, 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): 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.; 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): 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.; 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): Pirpiris, M.; Trivett, A.; Baker, R.; Rodda, J.; Nattrass, G. R.; and Graham, H. K.: Femoral derotation osteotomy in spastic diplegia. Proximal or distal? J Bone Joint Surg Br. 2003, 85(2):

7 14. Ryan, D. D.; Rethlefsen, S. A.; Skaggs, D. L.; and Kay, R. M.: Results of tibial rotational osteotomy without concomitant fibular osteotomy in children with cerebral palsy. J Pediatr Orthop. 2005, 25(1): Tinney A.; Thomason P.; Sangeux M.; Khot A.; and Graham HK: The transverse Vulpius gastrocnemuius recession for equinus gait in children with cerebral palsy. Bone Jt J. 2015, 97B(4) 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.; 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):