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1 Metadata of the chapter that will be visualized online Chapter Title Copyright Year 2013 Copyright Holder The Knee in Cerebral Palsy Springer-Verlag Berlin Heidelberg Corresponding Author Family Name Strobl Particle Given Name Walter Michael Suffix Division/Department Head of Clinic for Pediatric Orthopaedic & Neuroorthopaedic Surgery Organization/University Orthopaedic Hospital Rummelsberg City Schwarzenbruck Postcode State Nuremberg Country Germany Author Family Name Grill Particle Given Name Franz Suffix Division/Department Head of Pediatric Orthopaedic Department Organization/University Orthopaedic Hospital City Vienna State Speising Country Austria Abstract The knee joint should not be regarded as an isolated problem in cerebral palsy. Its function is dependent on the two-joint muscles hamstrings, rectus femoris, and gastrocnemius and it is closely connected to hip and ankle joint biomechanics. Therefore all knee joint disorders in cerebral palsy patients should be regarded as multi-level problems. Main clinical findings of the knee in cerebral palsy are crouch gait and stiff-knee gait, flexion and extension deformities, and disorders of the femoropatellar alignment. For successful treatment the pathologic mechanisms have to be fully understood. Special examination tools and therapy options are applied to gain satisfying long-term results. Goal is improvement of quality of life like pain free mobility for social integration. Keywords (separated by - ) Cerebral palsy - Clinical tests - Diagnosis, classification and evaluation - Knee - Natural history - Outcome measurement - Pathology - Special

2 investigations-film, gait analysis, EMG - Surgical correction of deformities - Therapeutic Options-conservative-casting, orthoses, physical therapy

3 Date:5/8/13 Time:06:22:07 Page Number: 1 1 The Knee in Cerebral Palsy 2 Walter Michael Strobl and Franz Grill 3 Contents 4 Introduction Pathology of the Knee in Cerebral Palsy Pre-Requisites for Normal Development Natural History Crouch Gait Fixed Knee Flexion Deformity Seating Problems Pathological Fracture Jump-Knee Gait Pattern Anterior Knee Pain: Pathology of Patello-Femoral 14 Joint Degenerative Arthritis Diagnostics and Evaluation GMFCS DLA-Daily Living Activities, Social Environment Sensory System and Cognitive Function Musculoskeletal and Motor System Radiographs Videofilms D-Gait Analysis Dynamic Electromyography Therapeutical Options Principles Physical Therapy Orthoses for Positioning and Guiding Growth Orthoses for Improving Function... 7 Ankle-Foot Orthoses (AFO)... 7 Serial Casting... 8 Systemic Drugs Local Drugs... 8 Botulinum Toxin A... 8 Surgical Treatment... 9 Surgical Procedures Outcome Measurements and Studies Short-Term Long-Term References W.M. Strobl (*) Head of Clinic for Pediatric Orthopaedic & Neuroorthopaedic Surgery, Orthopaedic Hospital Rummelsberg, Schwarzenbruck, Nuremberg, Germany walter.strobl@sana.de F. Grill Head of Pediatric Orthopaedic Department, Orthopaedic Hospital, Vienna, Speising, Austria Franz.grill@oss.at G. Bentley (ed.), Surgical Orthopaedics and Traumatology, DOI / _68, # Springer-Verlag Berlin Heidelberg

4 Date:5/8/13 Time:06:22:08 Page Number: 2 2 W.M. Strobl and F. Grill 41 Abstract 42 The knee joint should not be regarded as an 43 isolated problem in cerebral palsy. Its function 44 is dependent on the two-joint muscles ham- 45 strings, rectus femoris, and gastrocnemius and 46 it is closely connected to hip and ankle joint 47 biomechanics. Therefore all knee joint disor- 48 ders in cerebral palsy patients should be 49 regarded as multi-level problems. Main clini- 50 cal findings of the knee in cerebral palsy are 51 crouch gait and stiff-knee gait, flexion and 52 extension deformities, and disorders of the 53 femoropatellar alignment. For successful 54 treatment the pathologic mechanisms have to 55 be fully understood. Special examination tools 56 and therapy options are applied to gain satis- 57 fying long-term results. Goal is improvement 58 of quality of life like pain free mobility for 59 social integration. 60 Keywords 61 Cerebral palsy Clinical tests Diagnosis, 62 classification and evaluation Knee Natural 63 history Outcome measurement Pathology 64 Special investigations-film, gait analysis, 65 EMG Surgical correction of deformities 66 Therapeutic Options-conservative-casting, 67 orthoses, physical therapy spasticity usually starts during the second year and increases by the fourth year of life. Motor development improves gradually and most of the children will be able to walk freely between 3 and 7 years. Independent walking ability is subject to the primary neurological deficit, spasticity, associated sensory deficits, disorders of balance and motor symmetry, and to secondary muscle shortening, contractures, and bone and joint deformities. Clinical features include typical deformities of the lower limbs. Weakness as well as spasticity due to lack of selective neuronal control causes functional impairment and additional mechanisms of compensation, retardation of motor development, secondary deformities of muscles and soft tissues due to a failure of muscle growth, instability and dislocation of joints, early osteoarthritis, and pain. The main problems of the knee in cerebral palsy are crouch gait and stiff-knee gait, flexion and extension deformities, and disorders of the patello-femoral alignment. For successful treatment the pathologic mechanisms have to be fully understood. Special examination tools and therapy options are applied to gain satisfying longterm results. The goal is improvement of quality of life especially pain-free mobility for social integration Introduction 69 The knee joint should not be regarded as an 70 isolated problem in cerebral palsy. Its function 71 is dependent on the two-joint muscles ham- 72 strings, rectus femoris, and gastrocnemius and it 73 is closely connected to hip and ankle joint bio- 74 mechanics. Therefore all knee joint disorders in 75 cerebral palsy patients should be regarded as 76 multi-level problems. 77 Cerebral palsy is amongst the most frequent 78 disorders of the growing motor system. Spastic 79 diplegia is the most common form of cerebral 80 palsy. Prematurity is associated with the disease 81 in more than 60 %. After a period of muscular 82 hypotonia and delayed motor development, Pathology of the Knee in Cerebral Palsy Pre-Requisites for Normal Development Form follows function: normal development of the knee joint, leg biomechanics, standing and walking is dependent on physiological use, weight-bearing, muscular power and balance due to voluntary gross and fine motor function of the whole lower extremity. Pre-requisites of normal knee function are the daily use of a full range of motion, standing by a slight combined hyperextension and rotation of the joint, and energy cost-efficient walking

5 Date:5/8/13 Time:06:22:08 Page Number: 3 The Knee in Cerebral Palsy Voluntary motor control plays an important role 127 in normal muscular and power development. 128 Recent research has shown that the ability to 129 extend the knee during swing is dependent on the 130 selective voluntary motor control. Stance limb 131 muscle strength appears not to be the limiting 132 factor for achieving adequate knee extension [19]. 133 Natural History 134 As regards the motor system, cerebral palsy may 135 be defined as a disorder of selective neuronal con- 136 trol of muscles. Weakness as well as spasticity due 137 to this lack of control causes functional impair- 138 ment and additional mechanisms of compensation, 139 retardation of motor development, secondary 140 deformities of muscles and soft tissues due to 141 a failure of muscle growth, instability and disloca- 142 tion of joints, early osteoarthritis, and pain. 143 This means developing a vicious cycle of pri- 144 mary, secondary and tertiary deformities. 145 As children grow older, knee flexion in stance 146 and popliteal angle are increasing and gait veloc- 147 ity is decreasing. In a recent study Gannotti [17] 148 could find evidence for weak but significant rela- 149 tionships between these parameters, especially 150 for GMFCS II children. 151 Flexion deformity of the knee may be 152 primary, caused by spasticity and shortening of 153 the hamstrings. It may be secondary to compensate 154 for equinus deformity of the ankle and flexion 155 deformity of the hip. Or it may be functional to 156 lower the centre of gravity to achieve balance as it 157 is seen in patients with triceps surae weakness 158 following Achilles tendon lengthening [63]. Moderate crouch with anterior pelvic tilt Moderate crouch with equinus Severe crouch Age, range of motion, strength, selective motor control, and spasticity were significantly different between the clusters. So the authors recommend this classification for treatment decision-making and outcome assessment. Fixed Knee Flexion Deformity Structural shortening of muscles and contracture of the posterior knee joint capsule are insidious problems which may complicate the management of patients with cerebral palsy. These problems interfere with transfer standing and energy cost-efficient walking. Secondary pain may ensue as a result of fragmentation of the patella and tibial tubercle. Furthermore flexion deformities of hips and lumbar lordosis as well as pseudo-equinus of the ankles may develop. Seating Problems Short hamstrings interfere with normal sitting posture. The pelvis is tilted posteriorly causing progressive severe thoracic kyphosis and potential pulmonary dysfunction. Positioning and seating may be compromised. Pelvic asymmetry and progressive hip dislocation may be caused by untreated severe knee flexion contractures in GMFCS IV and V patients Crouch Gait 160 By k-means cluster analysis Rozumalski and 161 Schwartz [54] found five different clusters 162 among children with excessive knee flexion at 163 initial contact. They labelled these clusters in 164 order of increasing gait pathology: 165 Mild crouch with mild equinus 166 Moderate crouch Pathological Fracture Supracondylar femoral fractures are common and supposed to be under-diagnosed. Known predisposing factors are knee flexion deformity, lack of physical activity and sunlight exposure, anticonvulsant drugs and malnutrition. In epileptic patients fractures are six times more frequent than in the general population [65]

6 Date:5/8/13 Time:06:22:08 Page Number: 4 4 W.M. Strobl and F. Grill 205 Jump-Knee Gait Pattern 206 This gait pattern is defined by excessive knee 207 flexion at initial contact followed by rapid knee 208 extension to full knee extension in mid-stance. 209 Surgeons should bear in mind that after hamstring 210 lengthening excessive knee hyperextension may 211 occur in these patients. 212 Stiff-knee gait is the common gait pattern in 213 patients with rectus femoris spasticity. High 214 energy consumption reduces walking range and 215 mobility in daily life. 216 Rectus femoris spasticity and shortening 217 causes reduced range of motion of the knee 218 joint. Reduction of ROM in swing phase influ- 219 ences step length and biomechanical function of 220 bilateral hip and ankle joints as well as pathology 221 of the patello-femoral joint. 222 Anterior Knee Pain: Pathology of 223 Patello-Femoral Joint 224 Children with cerebral palsy who walk with 225 flexed knees develop a proximal displacement 226 of the patella ( Patella alta ). Cartilage degener- 227 ation may cause disabling pain in older patients. 228 Patella deformation is common in patients with 229 crouch gait. Clinical tenderness and fragmenta- 230 tion of the distal pole of the patella in radiographs 231 develops due to the constant pull of the patellar 232 tendon. 233 Patella alta alone, inferior pole fractures and 234 dislocations can commonly cause anterior knee 235 pain. Gait analysis and evaluation of the 236 rotational mal-alignment of the femur and 237 tibia should be recommended to detect 238 pathology for prevention of future functional 239 deterioration [56]. 240 Degenerative Arthritis 241 Flexion contractures of more than 20 induce 242 severe disabling degenerative arthritis in adults. 243 Many of these patients have been asymptom- 244 atic until the age of years [5] Diagnostics and Evaluation GMFCS The Gross Motor Classification System helps to distinguish CP patients according to their gross motor function abilities: Level I: free walking, level II: walking with aids, level III: walking with the support of walkers, level IV: transfer standing and walking with support, level V: positioning lacking head control. DLA-Daily Living Activities, Social Environment Knowledge about the patient s social integration and daily activities and skills are important for decision-making in deciding whether therapy programmes, casts, splints, drugs, or surgical procedures will be the appropriate means to reach the defined goal of functional improvement. According to the systemic approach the specialist will bring into consideration as many factors as possible. Sensory System and Cognitive Function The clinical examination of a CP patient consists of gathering information about basic neurogenic functions like sensory and proprioceptive function, equilibrium, vision, hearing, cognitive and communication abilities. Musculoskeletal and Motor System Observation of the individual walking pattern, active and passive joint mobility, ROM and measurement of muscle length are documented. Axial bone deformities, capsular joint contractures, structural and dynamic shortening of muscles have to be distinguished

7 Date:5/8/13 Time:06:22:09 Page Number: 5 The Knee in Cerebral Palsy Sliding of the patella in the patellar-femoral 281 groove has to be examined by full flexion and 282 extension of the knee. 283 Different patterns of crouch gait may be clas- 284 sified (see Pathology of Crouch Gait ). 285 Muscle spasticity is documented according to 286 the Ashworth scale [50]. 287 Muscle strength is measured according to the 288 Medical Research Council Scale [26]. 289 Length and spasticity of the hamstrings is 290 evaluated by measuring the popliteal angle test. 291 To palpate the hamstrings and get a better esti- 292 mate of shortening, the hip is flexed to 90 and 293 then the knee is extended to the limit permitted 294 by the hamstrings. The angle between the tibia 295 and the vertical line is measured or estimated it 296 is the popliteal angle. Ten Berge [64] did not see 297 any differences in reliability between visual esti- 298 mation and goniometric measurement. 20 is 299 considered to be normal. A recent study did not 300 find any change between examination in the 301 clinic versus under anaesthesia [39]. 302 Length and spasticity of the rectus femoris is 303 examined by the Duncan-Ely test in prone posi- 304 tion flexing the knee to the buttocks. The exam- 305 iner slowly flexes the child s knee on one side of 306 his or her body. If there is a rectus femoris con- 307 tracture the pelvis slowly rises off the examina- 308 tion table as the knee is flexed. This reaction is the 309 result of the rectus femoris crossing both the hip 310 and the knee joint. In addition to testing contrac- 311 ture, the test also can examine the rectus muscle 312 for spasticity but the quadriceps stretch has been 313 shown to elicit a reflexive iliopsoas firing that 314 may also cause hip flexion [11]. 315 The amount of a flexion contracture of the 316 knee joint is measured while the limb lies flat on 317 the table. If firm pressure on the anterior aspect of 318 the knee fails to extend the joint to 0 a contracture 319 of the posterior capsular in addition to the ham- 320 string shortening is likely. 321 Length of gastrocnemius and soleus is evalu- 322 ated by the Silverskjöld test. Passive ankle 323 dorsiflexion is estimated with (soleus) and with- 324 out (gastrocnemius) knee flexion. McMulkin 325 et al. [39] described a significant change of 326 dorsiflexion angle between examinations in the clinic versus under anesthesia in children younger than 11 years. Radiographs In CP patients radiographic evaluation of the femur, tibia and patella are routinely used to diagnose patellar abnormalities, axial deformities, disturbances of growth-plates, disorders of the border area between bone and cartilage, to exclude pathological fractures especially of the supracondylar femur region. Additional investigations of the knee in CP are made by MR or CT scan. Videofilms The evaluation of films with slow motion functions helps to differentiate functional gait disorders. Furthermore films play an important role in the documentation of the treatment and rehabilitation process and should belong to the routine equipment of a cerebral palsy clinic. 3D-Gait Analysis The role of gait analysis in the management of CP patients is controversial. In the evaluation of knee problems in cerebral palsy patients concerning decision-making for surgery the authors recommend its routine clinical use. Clinical gait analysis helps to distinguish ambulatory children with CP who would benefit from surgery from those in whom non-operative management is appropriate [22, 23]. It is useful in defining indications for surgery that is clinically proposed, and for excluding or delaying surgery that is clinically proposed [36]. Dynamic Electromyography Dynamic EMG datas give insight in the function of muscles during the gait cycle. Spastic muscle activities around the knee as cause of reduced

8 Date:5/8/13 Time:06:22:09 Page Number: 6 6 W.M. Strobl and F. Grill 362 stance phase stability or swing phase mobility 363 may be identified. Its routine use eases the com- 364 position of therapy programs and the indication 365 for surgical procedures. 366 Therapeutical Options 367 Principles 368 Weakness, as well as spasticity due to lack of 369 selective neuronal control, causes functional 370 impairment and additional mechanisms of com- 371 pensation, retardation of motor development, sec- 372 ondary deformities of muscles and soft tissues due 373 to a failure of muscle growth, subluxation/disloca- 374 tion of joints, early osteoarthritis, and pain. 375 Prevention of this vicious cycle of primary, 376 secondary and tertiary deformities may be 377 defined as the main goal of caring for children 378 and young adults with spasticity. 379 Early detection of a progressive knee flexion 380 contracture is crucial in qualified Orthopaedic 381 screening programmes for CP patients. Optimal 382 function of the knee joint is one of the most 383 important pre-requisites for life-time transfer 384 standing and walking with adequate energy 385 consumption. 386 By clinical Orthopaedic examination an 387 exact differentiation of conditions with increased 388 muscle tone or reduced ROM has to be 389 performed: 390 Reduced muscle tone may need stabilizing 391 treatment like orthoses 392 Normal tone will not need treatment 393 Increased muscle tone may be treated by phys- 394 ical means like warmth, massage, continuous 395 active or passive movement 396 Spasticity (typical clinical diagnosis) is the 397 indication for treatment by BTX (Botulinum 398 Toxin A) 399 Dynamic shortening of muscles may be 400 treated by stretching exercises or/and casts in 401 combination with BTX 402 Structural shortening of muscles is to be 403 treated only by surgical intra-muscular or apo- 404 neurotic lengthening in combination with 405 exercises, casts and orthoses Capsular contractures may need additional osseous procedures Bone and joint deformities will need combined soft tissue and osseous reconstructional surgery followed by activating long-term rehabilitation. Quality of life of children and adults with cerebral palsy can be improved by support of their daily living motor activities. Regular joint movement, weight bearing, improvement of motor control and strength-training are the main methods. Increased muscle tone may be reduced by physical exercises, by individually-adapted orthoses, especially ankle-foot-orthoses (AFO), walkers, and sometimes wheelchairs for long distances, by manual therapy, serial casting and in certain cases by systemic drugs or by multiplestage surgical procedures. Operative treatment is indicated when conservative measurement is failing to reduce spasticity and orthoses are not able to counteract weakness in order to improve motor development and maturing of personality. In the past, the first surgical procedures have commonly become necessary between 3 and 5 years. Careful multi-level surgery procedures like adductor release, hamstring release, and gastrocnemius-lengthening have been performed at that age, sometimes done at the right age to reach independent walking. Until today studies confirm that surgical intervention in selected young children can result in improvements in gait and function in the short to mid-term compared with non-operative management [23]. Today these procedures are still indicated, but by injections of Botulinum Toxin in this age group surgery may be delayed to early puberty. So a decreasing number of children are in need of repeated muscle releases during their growth. Usually a one multi-level procedure including rotational deformities is performed to improve walking, to get better motor symmetry and to reduce energy consumption in daily locomotion (see Fig. 1). In the long run, quality of life for adults with cerebral palsy is determined by self-assured mobility for adequate social integration and pain-free walking or at least transfer standing

9 Date:5/8/13 Time:06:22:09 Page Number: 7 The Knee in Cerebral Palsy 7 approaches to determine the causes of weakness are needed to identify those individuals who are most likely to benefit from strengthening [8] Orthoses for Positioning and Guiding Growth Fig. 1 Indication for functional improvement: active and passive ROM, muscular shortening, spasticity, power, selective control, function during stance phase and swing phase have all to be evaluated Knee-Ankle-Foot Orthoses (KAFO) By supporting physical stretching exercises KAFOs may prevent knee flexion deformities and increase knee extension in stance. They can be temporarily used as day or night splints. Cartilage nutrition and patient s compliance may be improved by the use of elastic joints which allow defined motion of spastic hamstrings or biceps femoris muscles. Stable undisplaced supracondylar femoral fractures are treated with a KAFO (Knee-anklefoot Orthosis). Callus formation and stability for early mobilization is commonly observed 3 4 weeks after the event without progressive deformities up to an older 455 age. All of them will be in need of specialized 456 physical therapy and rehabilitation programs 457 [10, 12, 20, 46, 58]. 458 Physical Therapy 459 Reduction of muscle tone and spasticity may be 460 obtained by application of warm temperature, mas- 461 sage, reflex therapy, osteopathic handling, and 462 continuous active and passive movement therapy. 463 Physical stretching exercises are improving 464 dynamic shortening of spastic muscles and reduc- 465 ing spasticity. 466 The effect of electrical stimuation is contro- 467 versial. Combined with passive stretching it is 468 described to be marginally more effective than 469 passive stretching alone [31]. 470 Strength training may improve walking 471 function and alignment in patients for whom 472 weakness is a major contributor to their gait 473 deficits. Due to the variability of outcomes in 474 several strengthening studies in CP, analytical Orthoses for Improving Function Orthopaedic shoes may improve knee extension in stance. Studies indicate the potential clinical utility of tuning using wedges to correct knee hyperextension during the stance phase [28]. Ankle-Foot Orthoses (AFO) AFOs improve toe-walking in children with CP. Studies comparing different kinds of dynamic orthoses describe improvement of gait pattern but only small differences between the configurations of the orthoses [66]. Hinged and dynamic AFOs are equally effective for improving ankle kinematics and kinetics in GMFCS level I children [57]. In quadriplegic children the use of an AFO results in a significant decrease in energy cost of walking compared with barefoot walking. It is related to both a faster and more efficient walking pattern. The improvements in efficiency are

10 Date:5/8/13 Time:06:22:09 Page Number: 8 8 W.M. Strobl and F. Grill 514 reflected in changes of stance and swing 515 phase knee motion towards a typical normal 516 range [6]. 517 The floor-reaction ankle-foot orthosis is 518 commonly prescribed for CP children who 519 walk with excessive knee flexion and ankle 520 dorsiflexion during the stance phase of gait. It 521 is effective in restricting sagittal plane ankle 522 motion during stance. Best outcomes are 523 reported in subjects with knee and hip flexion 524 contracture of less than 10. Contractures of 525 more than 15 should be considered as contra- 526 indications [52, 53]. 527 Serial Casting 528 Application of short-leg casts is regarded as 529 a simple, safe, cost-effective, and well- 530 established procedure to reduce spasticity and 531 improve walking. The tonic stretch reflex of spas- 532 tic muscles is used as treatment principle. 533 Dynamic lengthening of both gastrocnemius 534 heads improves knee extension in stance. Casts 535 are applied for about 4 weeks. Shortened muscles 536 are gradually stretched by serial casts which are 537 applied one or two times per week. Special pad- 538 ding is necessary to avoid skin breakdown. Pro- 539 ducing iatrogenic flatfoot- or clubfoot 540 deformities have to be prevented by casting in 541 slight overcorrection of the hindfoot. Serial casts 542 can be applied even in children with mental sub- 543 normality having all three major joints involved 544 bilaterally. In contrary to more sophisticated 545 orthoses this procedure is also commonly used 546 in developmental projects because of its 547 described advantages. 548 Systemic Drugs 549 The centrally effective antispastic drug Baclofen 550 is used as systemic tone-reducing agent. Stiff- 551 knee gait as part of general spasticity is reported 552 and experienced to be improved significantly. 553 Application of higher dosages may cause side- 554 effects like fatigue and reduction of the patients 555 vigilance. Local Drugs Neurotoxins like phenol and botulinum toxin A are applied directly to the nerve or muscle in order to reduce spasticity and muscular imbalance and to improve the potential underlying voluntary motor activity. Botulinum Toxin A Principles: Today BTX A is suggested to be one of the most powerful and useful tools in reducing spasticity. Repeated injections have a long-term effect on gross motor function in children with CP. In spite of this fact, Molenaers has already been pointing out that BTX-A injections cannot be viewed in isolation, as they are only one aspect of an integrated approach to the multi-disciplinary treatment, and there is still uncertainty about their use in children with CP (Goldstein). On the one hand uncertainty about usage, on the other high effectivity and demand for BTX may lead to a dangerous combination leading to uncritical overuse of this new treatment tool. Over the past years discussions at Orthopaedic and Paediatric seminars and congresses showed that a considerable number of BTX users are still forgetting to use physical exercises, individually adapted orthoses, positioning devices, walking splints, serial casting, systemic drugs or surgery for reducing tone and improving muscle function (Heinen). First limitations of BTX treatment have been reported in some studies: Glanzmann found that in children with spastic equinus deformity casting demonstrated a significantly more robust impact on ROM than BTX-A alone. Kay stated that serial casting alone is preferable for the treatment of fixed equinus contractures. Concerning the treatment of progressive hip dislocations there is a significant difference between children with CP treated by multi-level soft-tissue-surgery and those treated by series of BTX-injections of the same muscles. They suppose the anti-spastic effect of BTX has not been as continuous as surgical tone reduction. Improvement of knee function: Crouch gait and stiff-knee gait may be improved by multi

11 Date:5/8/13 Time:06:22:10 Page Number: 9 The Knee in Cerebral Palsy level BTX-injections applied to hamstrings, 601 rectus femoris and gastrocnemius muscles. 602 Significant effects of BTX-treatment are reported 603 in those cases where common treatment methods 604 like physical exercises, individually adapted 605 orthoses, positioning devices, walkers, serial 606 casting, systemic drugs or multi-level-surgery 607 are supported by the local tone reducing agents. 608 Non-combined BTX-treatment has been sig- 609 nificantly successful in ambulant patients with 610 adequate motor control and power of hip and 611 knee muscles. 612 Using BTX as only an additional agent 613 supporting combined treatment methods has the 614 advantage of elongated intervals between injec- 615 tions. In some children one single injection opens 616 the door to new possibilities of sensorimotor devel- 617 opment and injection of hamstrings and rectus may 618 be the key to free walking. Individually defined 619 trigger-muscles seem to play an important role. 620 Adverse effects: Weakness, speech disorders, 621 pain or swelling were seen temporarily after BTX 622 A injections. All side effects disappeared after 623 a few days (Cosgrove, Koman, Wissel). Until 624 now reported single severe cardiopulmonary 625 complications and lethal cases cannot be clearly 626 causally related to the application of BTX. Long- 627 term side-effects have not been described in the 628 treatment of cerebral palsy, however long-term 629 studies are lacking. Outcome studies about long- 630 term results show contrary results. On the one 631 hand the beneficial anti-spastic effect of BTX 632 A maintained after repeated treatment cycles 633 (Bakheit), on the other, recent studies show 634 decreasing therapeutic effects and structural 635 changes of the injected muscles. 636 BTX in Current Treatment Plans: Asan 637 additional agent BTX A is able to fortify the effect 638 of conservative treatment options. BTX-A injec- 639 tions should not be viewed in isolation, as they are 640 onlyoneaspectofanintegratedapproachtothe 641 multidisciplinary treatment of children with CP. 642 We consider the careful selection of patients and 643 the establishment of a goal-orientated treatment 644 plan by a multi-disciplinary team approach, as 645 the most important steps of this method. Pre- 646 requisites are exact statomotoric and dynamic 647 physical examinations, and standardized movement analysis. 3D-gait analysis, and dynamic electromyography should be reserved for those cases where functional improvement of gait is the goal of BTX A-treatment. Further investigations have to be made to define clearly the limitations of BTX-treatment. It should not be regarded as an exclusive treatment, and other conservative methods and/or surgical interventions should be used whenever they prove to be superior [2 4, 7, 14, 18, 24, 25, 27, 30, 33, 34, 37, 40, 41, 43, 45, 47, 60, 62, 68]. Surgical Treatment Principles Surgery in cerebral palsy needs specialized knowledge and experience. Functional problems have to be detected as early as possible, they have to be analysed, pathologies have to be understood and addressed at the right age by the optimal surgical method in a well-dosed manner. The Paediatric Orthopaedic surgeon Mercer Rang used to emphasise the point: the indication is more important than the incision. Surgeons have to be aware of post-operative complications like nerve palsy especially in noncommunicative and non-ambulatory adolescents, persistent pain especially in cognitive disabled individuals, temporarily or persisting increased spasticity, skin breakdown at the heel especially in patients with sensory and/or communicative deficits, deformity recurrence, persistent muscle weakness in spite of training programmes, necessity for walking aids and delay in the rehabilitation process. Optimal post-operative pain control eases spasticity and avoids the vicious spasm-pain-cycle. Immobilization always has to include adequate padding of risk sites for skin breakdown such as heels, ankle joint, patella, and the dorsal proximal femur region. Vigilance in patients with epidural pain control to avoid nerve palsies following excessive knee extension and hip flexion is warranted. In the case of symptoms immediate knee flexion is necessary to avoid persistent motor and sensory deficits

12 Date:5/8/13 Time:06:22:10 Page Number: W.M. Strobl and F. Grill 693 Despite the normalization of ROM after sur- 694 gery there is an early post-operative period of 695 functional gait deterioration which has to be con- 696 sidered. Early mobilization and strength training 697 needs perfect team work and interdisciplinary 698 management between surgeons, rehabilitation 699 specialists, physical and occupational therapists, 700 and orthopaedic technologists. 701 Surgical Procedures 702 Intramuscular medial hamstring lengthening 703 Clinical problem: hamstring spasticity 704 causes a dynamic knee flexion deformity 705 which is an indication for this procedure. 706 This prohibits knee extension during the 707 stance phase of gait and interferes with 708 efficient ambulation. Progressive struc- 709 tural shortening produces severe crouch 710 gait, an indication for surgery. Reducing 711 knee pain, improving function and inde- 712 pendence may be expected. A jump-knee 713 gait pattern (see Pathology of the 714 Knee ) should be regarded as contra- 715 indication [1]. 716 Treatment principles: to reduce energy con- 717 sumption and improve upright posture sur- 718 gical lengthening of the hamstrings 719 corrects the dynamic knee flexion defor- 720 mity. Intra-muscular lengthening allows 721 controlled weakening and preserving the 722 function of the muscles. This procedure 723 has commonly replaced the Egger s trans- 724 fer of the hamstrings to the femoral 725 condyles. Only a slight effect on internal 726 hip rotation can be expected by the proce- 727 dure [38]. 728 Diagnostics and evaluation: GMFCS, daily liv- 729 ing activities, ROM, spasticity according to 730 Ashworth scale, muscle strength according 731 to Oxford scale, radiographs, 3D gait anal- 732 ysis, dynamic electromyography. Because 733 of the poor inter-observer reliability of the 734 popliteal angle measurement, this should 735 not be the only variable in clinical deci- 736 sion-making [64]. Surgical technique: patient in supine position, longitudinal incision 5 cm in length over the myotendinous region of hamstrings, sharp dissection of the gracilis, semitendinosus, and semimembranosus tendon within the muscular portion of the muscles, allowing the tendons to slide distally; no sutures are required to repair the tendons (see Fig. 2). Complication: nerve palsy especially in noncommunicative, non-ambulatory adolescents and adults, deformity recurrence, increase of anterior pelvic tilt, knee hyperextension/genu recurvatum Percutaneous medial hamstring tenotomies In selected patients this minimally- invasive technique may be superior to open lengthening and several studies describe the short- and long-term outcome to be sufficient. Intra-muscular biceps femoris lengthening Clinical problem: Severe structural shortening of hamstrings commonly are associated with structural shortening of biceps femoris. The surgeon has to be aware of protecting the peroneal nerve. Tenotomy of hamstring and biceps femoris muscles Clinical problem: non-walking patients, severe shortening of muscles interfering with seating and positioning, progressive wind-swept deformity and hip dislocation due to additional adductor and abductor deformity Complication: high risk of nerve palsy especially in non-communicative, nonambulatory adolescents and adults Proximal tenotomy of hamstring muscles Seymour and Sharrard described this highly effective release of hamstrings from their origin on the ischial tuberosity. The sciatic nerve and posterior femoral cutaneous nerve have to be identified and retracted. The authors recommend this procedure in cases of severe recurrence or shortening of hamstrings combined with functional disabling posterior pelvic tilt

13 Date:5/8/13 Time:06:22:10 Page Number: 11 The Knee in Cerebral Palsy 11 Fig. 2 Medial hamstring lengthening: circular cutting of muscular fascia of semitendinosus and semimembranosus muscles effects intramuscular lengthening; z-lengthening is performed of the tendon of gracilis 784 Distal transfer of rectus femoris muscle 785 Clinical problem: rectus femoris spasticity 786 causes reduced knee flexion during the 787 swing phase. This prohibits adequate step 788 length and interferes with efficient ambula- 789 tion resulting in a stiff-legged gait. To 790 achieve adequate limb clearance compen- 791 satory circumduction of the involved limb 792 or pathologic pelvic movement is 793 necessary. 794 Diagnostics and evaluation: GMFCS (caution 795 in level IV patients), daily living activities, 796 ROM, spasticity according to Ashworth 797 scale, hip and knee muscle strength 798 according to Oxford scale, and knee flexion 799 velocity at toe-off by 3D gait analysis, 800 dynamic electromyography 801 Surgical technique: longitudinal or transverse 802 (recommended by the authors) 3 cm prox- 803 imal to the proximal patellar pole, prepara- 804 tion of the rectus tendon. It should be free 805 of adherent tissue for cm dependent 806 on the patient s muscle size; tenotomy proximal of the patella. As regards transfer site several muscles are regarded as producing equal results: semitendinosus, sartorius, and gracilis [42]. Popliteal skin incision, preparation of the gracilis muscle (recommended) by the use of a tendon stripper, it should be free of adherent tissue for cm. After creating a lacuna in the intramuscular septum the distal rectus and proximal gracilis are sutured in a limb position of 30 knee flexion. The flat and broad rectus tendon may form a cylinder around the thinner and round gracilis tendon. After suture, function is proved by full knee flexion and extension (see Fig. 3). Release of rectus femoris muscle Clinical problem: rectus femoris spasticity causing reduced knee flexion during the swing phase. For the pathological mechanism also see distal transfer of rectus femoris muscle. Diagnostics and evaluation: GMFCS, daily living activities, ROM, spasticity

14 Date:5/8/13 Time:06:22:11 Page Number: W.M. Strobl and F. Grill Fig. 3 Distal transfer of the rectus femoris muscle: The cut and transferred gracilis or semitendinosus tendon is sutured to the rectus tendon while positioning the knee joint in 30 flexion 830 according to Ashworth scale, hip and knee 831 muscle strength (Oxford scale), 3D gait 832 analysis, dynamic electromyography 833 Surgical technique: both techniques for prox- 834 imal as well as for distal release are 835 described. The approach for distal rectus 836 release is the same as for transfer. For full 837 elimination of rectus function resection of 838 the muscle or at least of its tendinous part is 839 necessary. 840 Proximal release: Rectus femoris tendon is 841 prepared distal to its origin to the inferior 842 iliac spine after a 4 cm skin incision and 843 medial retraction of the sartorius. For total 844 release a tenotomy is performed and for 845 tone-reducing lengthening, intra-muscular 846 tendinous fibres are cut. Muscle length is 847 achieved by flexing the knee in hip exten- 848 sion and slight abduction (see Fig. 4). 849 Distal release of rectus femoris and vastus 850 intermedius muscles have been described for 851 cases of severe functionally-disabling spastic- 852 ity of both muscles. 853 Isolated lengthening of gastrocnemius fascia 854 Clinical problem: gastrocnemius spasticity 855 and muscle shortening without soleus 856 Treatment principle: improving range of 857 motion and reducing spasticity whilst pre- 858 serving as much muscle strength as possi- 859 ble in push-off 860 Surgical technique: longitudinal skin incision 861 over the myotendinous region of the calf, 862 aponeurotic release of gastrocnemius fibres Fig. 4 Proximal lengthening of rectus femoris muscle: The tendon is prepared distal to its origin from the anterior inferior iliac spine, the sartorius muscle is retracted medially, and intramuscular tendinous fibres are cut. Muscle length is checked by flexing the knee in hip extension and slight abduction according to Strayer or Vulpius (See Fig. 5). Release of medial and lateral long heads of gastrocnemius Clinical problem: severe gastrocnemius shortening and knee joint contracture. Treatment principle: improving range of motion and in ambulant patients reducing energy consumption when weight-bearing. Surgical technique: medial and lateral longitudinal skin incisions over the popliteal region, preservation of neurovascular structures, tenotomies of all identified gastrocnemius fibres at their origin from the distal dorsal femur. Optionally perform combined hamstring and knee joint capsular release from the same surgical approach. Posterior capsular release of the knee joint

15 Date:5/8/13 Time:06:22:11 Page Number: 13 The Knee in Cerebral Palsy 13 Fig. 5 Isolated lengthening of gastrocnemius muscle: longitudinal skin incision over the myotendinous region of the calf, aponeurotic release by cutting the fibres only of the gastrocnemius muscle 882 Clinical problem: fixed knee flexion deformity 883 in patients with free hip extension and 884 ankle dorsiflexion. 885 Surgical technique: prone position, two longi- 886 tudinal or one s-shape skin incision over the 887 popliteal region, hamstring and biceps 888 femoris lengthening, preparation and 889 retraction of neurovascular bundle, reces- 890 sion of medial and lateral long heads of 891 gastrocnemius, full posterior capsulotomy 892 of the knee joint. Check full knee extension 893 in hip extension and dorsiflexion of ankles. 894 Complications: high risk of neurovascular 895 damage, under-correction, deformity 896 recurrence, increase of anterior pelvic tilt. 897 Distal supracondylar femoral extension 898 osteotomy 899 Clinical problem: fixed knee flexion deformity 900 Surgical technique: as part of multi-level sur- 901 gery on lower limbs 902 Unstable displaced supracondylar femur frac- 903 tures may be corrected and stabilized by 904 this method. The authors prefer this proce- 905 dure to closed or open reduction for 906 avoiding neurovascular damage (see 907 Fig. 6). 908 Complications: undercorrection, mal-union, 909 deformity recurrence, neurovascular Fig. 6 Distal supracondylar femoral extension osteotomy: After hamstring lengthening a dorsal wedge of the femur is removed for shortening in order to prevent neurovascular damage, and possible under-correction, and deformity recurrence; medial or lateral fixation by plate damage, post-operative necessity for walking aids, increase of anterior pelvic tilt. Patellar tendon advancement Clinical problem: persistent crouch gait in adolescents and young adults, quadriceps insufficiency due to quadriceps spasticity and structural shortening, patella alta, and elongated patellar tendon. Surgical technique: distal patellar tendon advancement is performed by plication of the patella tendon only or capturing the patella by a wire suture, pulling it distally and fixing it in its normal position (see Fig. 7). Frame distraction Clinical problem: fixed knee flexion deformity, gradual correction as surgical alternative to posterior capsulotomy or supracondylar extension osteotomy. Complications: high risk of neurovascular damage, recurrence after frame removal, loss of fixation, pathological supracondylar femur fracture. Guided-growth by temporary hemiepiphyseodesis of anterior distal femoral growth-plate [32]

16 Date:5/8/13 Time:06:22:12 Page Number: W.M. Strobl and F. Grill Surgical technique: dissection of selected nerve roots by the neurosurgically-trained surgeon. Complication: uncontrollable weakness Outcome Measurements and Studies 971 Short-Term 972 Fig. 7 Patellar tendon advancement: before closure of growth-plates, plication of the patella tendon, after growth-arrest, distal transfer of a cm tibial wedge and additional capturing of the patella by a wiresutue, pulling it distally and fixing it in its normal position 936 Clinical problem: fixed knee flexion defor- 937 mity, gradual correction by this minor sur- 938 gical alternative to posterior capsulotomy 939 or supracondylar extension osteotomy. 940 Surgical technique: identifying site of the 941 anterior distal femoral growth-plate by 942 image intensifier in sagittal and frontal 943 planes, temporarily fixation of the growth- 944 plate by two staples or eight-plates, no 945 post-operative immobilization. Hardware 946 has to be removed after full correction. 947 Complication: reduced knee range of motion, 948 hardware migration, too slow a correction. 949 Selective Dorsal Rhizotomy (SDR) 950 Clinical problem: hamstring spasticity causes 951 a dynamic knee flexion deformity. This 952 prohibits knee extension during the stance 953 phase of gait and interferes with efficient 954 ambulation. Rectus femoris spasticity pro- 955 duces stiff-knee walking. 956 Treatment principles: reduction of spasticity 957 may correct the dynamic knee flexion and 958 stiff-knee deformity by decreasing energy 959 consumption and improving upright 960 posture. 961 Diagnostics and evaluation: GMFCS, daily 962 living activities, ROM, spasticity 963 according to Ashworth scale, muscle 964 strength according to Oxford scale, radio- 965 graphs, 3D gait analysis, dynamic 966 electromyography Studies comparing different kinds of dynamic orthoses describe improvement of gait pattern but only small differences between the configurations of the orthoses [66]. Hinged and dynamic AFOs are equally effective for improving ankle kinematics and kinetics in GMFCS level I children [57]. In hemiplegic children hinged AFOs slightly decrease proximal muscle activity (according to the change from toe gait to heel-toe gait), improve stride length, decrease cadence, improve walking speed, increase hip flexion, improve kinematics in loading response phase at the knee, and reduce excessive ankle plantarflexion [53]. In quadriplegic children the use of an AFO results in a significant decrease in energy cost of walking compared with barefoot walking [6]. Electrical stimulation combined with passive stretching is described to be marginally more effective than passive stretching alone [31]. Serial casting is regarded as simple effective procedure for reducing spasticity and improving gait pattern. Significant improvement in gait analysis is noticed in range of motion around hip, knee ankle which continues for months, advancing the child s gross motor development. Several studies show that combined hamstring release and rectus transfer may obtain a significant improvement of static parameters, time-distance parameters, knee and ankle kinematics in children with crouch gait. Gough [23] described surgical intervention in selected young children which resulted in improvements in gait and function in the short to mid-term compared with non-operative management

17 Date:5/8/13 Time:06:22:12 Page Number: 15 The Knee in Cerebral Palsy Westwell [67] found encouraging results of 1012 combined multi-level Orthopaedic interventions 1013 also in adolescents and young adults with CP Pre- and post-operative gait evaluation showed 1015 an improved knee extension at initial contact 1016 following hamstring lengthenings and an 1017 improved peak knee flexion in swing following 1018 rectus femoris transfers Lovejoy [38] could find only a slight effect of 1020 hamstring lengthening on hip rotation. Patients 1021 did not improve enough to change from internal 1022 to external rotation at the hip; rotation 1023 osteotomies had to be recommended Karol [29] stated the high risk of nerve palsy 1025 which occurred in almost 10 % of patients under going hamstring lengthening. Although the 1027 greatest risk was in non-communicatible and 1028 non-ambulatory adolescents, younger ambula tory patients developed palsies as well. Resolu tion of symptoms occurred in 82 % of patients Concerning rectus femoris transfers Reinbolt 1032 [48] tried to establish a predictive model to deter mine whether or not knee motion will improve 1034 after surgery with greater than 80 % accuracy Correct prediction has been possible by 1036 a combination of hip power, knee power, and 1037 knee flexion velocity at toe-off. Rethlefsen [49] 1038 reports that GMFCS has been predictive of out come. Level IV patients may not benefit from 1040 distal rectus transfer because of increased post operative crouch Muthusamy [42] recommends the procedure 1043 regardless of the transfer site. He did not find 1044 significant kinematic and kinetic differences 1045 between transfers to semitendinosus, sartorius, 1046 and gracilis Outcome studies confirm distal femur exten sion osteotomy as an effective procedure in 1049 increasing knee extension in the stance phase Some authors [9] indicate potential risks for 1051 a post-operative increase in anterior pelvic tilt, 1052 deformity recurrence, and necessity for walking 1053 aids Recent studies state that inclusion of patellar 1055 tendon advancement is necessary to achieve opti mal results in the surgical management of 1057 a persistent crouch gait exhibited by adolescents 1058 and young adults. When this procedure is done alone or in combination with a distal femoral extension osteotomy, knee function can be restored to values within typical limits, with gains in community function [44, 59]. Saraph [55] found that gait function continues to change over 3 years of post-operatively. He recommends evaluation of gait improvement surgery at a minimum of 3 years post-operatively to give the most predictive outcome. Long-Term BTX-A injections have a long-term effect on gross motor function in children with CP even though the effect on muscle tone is short-term. Fattal-Valevski [15] reports that the effect appears to decline with repeated injections. Children who demonstrated faster postoperative gait velocity 4 years or more after multi-level surgery were younger at the time of initial evaluation, had undergone fewer surgical procedures, had faster post-operative gait velocity, used ankle-foot orthoses post-operatively, and had increased hip extension ROM post-operatively in a multi-variate approach study [16]. Five years post-operatively multi-level surgery for children and adolescents with severe crouch gait has been effective for relieving stress on the knee extensor mechanism, reducing knee pain, and improving function and independence [51]. In his long-term evaluation of isolated gastrocnemius fascia lengthening Galli [13] found improved ankle and knee kinematics and limb function without producing functional muscle weakness over time. Gordon [21] described short- and long-term outcome of the minimally-invasive percutaneous medial hamstring lengthening to be sufficient. Twenty years after selective dorsal rhizotomy patients showed improved locomotor function compared with their pre-operative status [35]. Knee joint disorders in cerebral palsy patients should be regarded as multi-level problems. They have to be addressed according to the results of biomechanical analysis, considering age, Gross Motor Function Level, and corresponding lifetime goals of the patient. Therefore especially in

18 Date:5/8/13 Time:06:22:13 Page Number: W.M. Strobl and F. Grill LIVING WITH CP Pain, musculoskeletal deformities LIFE TIME GOALS Severe CP seating device PT standing orthosis BoNT soft tissue surgery hip reconstr. surgery knee reconstr. surgery foot Reconst. surgery painfree positioning transferstanding transferwalking assisted walking Mild walking Improving surgery CP Walking ability Free walking years Fig. 8 Algorithm for therapy in children with cerebral palsy: Typical start time for therapeutic indications depending on age, Gross Motor Function Level, and corresponding life-time goals 1104 children with cerebral palsy the typical start time 1105 for therapeutic indications may be described by 1106 an algorithm for therapy as seen in Fig. 8 [61] References Adolfsen SE, et al. Kinematic and kinetic outcomes after 1109 identical multilevel soft tissue surgery in children with 1110 cerebral palsy. J Pediatr Orthop. 2007;27(6): Bakheit AM, et al. The beneficial antispasticity effect 1112 of botulinum toxin type A maintained after repeated 1113 treatment cycles. J Neurol Neurosurg Psychol ;75(11): Barnes MP. Upper motor neurone syndrome and the 1116 spasticity. Cambridge: Cambridge University Press; Barwood S, et al. Analgesic effects of botulinum toxin 1119 A: a randomized, placebo-controlled clinical trial. Dev 1120 Med Child Neurol. 2000;42: Bleck EE. Orthopaedic management in cerebral palsy Oxford/Lipincott/Philadelphia: Mac Keith Press; Brehm MA, et al. Effect of ankle-foot orthoses on 1124 walking efficiency and gait in children with cerebral 1125 palsy. J Rehabil Med. 2008;40(7): Cosgrove AP, et al. Botulinum toxin in the management of the lower limb in cerebral palsy. Dev Med Child Neurol. 1994;36: Damiano DL, et al. Can strength training predictably improve gait kinematics? A pilot study on the effects of hip and knee extensor strengthening on lowerextremity alignment in cerebral palsy. Phys Ther De Morais Filho MC, et al. Treatment of fixed knee flexion deformity and crouch gait using distal femur extension osteotomy in cerebral palsy. J Child Orthop. 2008;2(1): Döderlein L. Infantile cerebralparese. W urzburg: Steinkopff; Dormans JP, Pellegrino L. Caring for children with cerebral palsy. A team approach. Baltimore: Paul Brookes; Gage JR. Gait analysis in cerebral palsy. London: Mac Keith Press; Galli M, et al. Long-term evaluation of isolated gastrocnemius fascia lengthening in children with cerebral palsy using gait analysis. J Pediatr Orthop B. 2009;18(5): Fattal-Valevski A, et al. Parameters for predicting favourable responses to botulinum toxin in children with cerebral palsy. J Child Neurol. 2002; 17(4):