ORIGINAL ARTICLE
Neurological Complications After Supracondylar Femoral Osteotomy in Cerebral Palsy Muharrem I˙nan, MD,* I˙lker Abdullah Sarıkaya, MD,w Enis Yıldırım, MD,z and Mehmet Fatih Gu¨ven, MD*
Background: Knee flexion contracture in children with cerebral palsy (CP) is very common and functional impairment leads to a crouch gait. Correction of the knee flexion contracture and improvement of the gait pattern by supracondylar femoral extension osteotomy seems to be a more effective method than distal hamstring procedures in long-standing severe crouch. Only a small number of publications reported the neurological complications of this surgical technique. This study was planned to identify the risk factors leading to neurological complications after supracondylar femoral extension osteotomy in patients with CP. Methods: Supracondylar femoral osteotomies performed for a primary diagnosis of CP with rigid knee flexion deformity of 10 to 30 degrees were included in the study. Supracondylar femoral extension osteotomy was performed in 28 patients (total: 48 cases). Neurological complication was not detected in 43 cases (group 1) and detected in 5 cases (group 2). Previous surgical operation, concomitant operations on the same extremity, application of a brace or long leg cast after operation, preoperative and postoperative popliteal angle, amount of correction, radiologic correction, tourniquet time, level of malnutrition, and emotional state were reviewed. Results: There were 18 boys and 10 girls. The mean age was 12 ± 4 years in group 1 and 13 ± 1 years in group 2. Except 6 patients, all patients had concomitant operations (38 cases in group 1 and 4 cases in group 2). Postoperatively, long leg cast was used in 38 cases and brace in 10 cases. In group 1 mean correction was 23 ± 3.8 degrees and in group 2 it was 19 ± 5.7 degrees. Conclusions: Correlation was not found between the incidence of neurological complications and amount of correction and deformity. After supracondylar femoral extension osteotomy, all patients must be suspected of neurological complication, and measures taken to alleviate the stretch at once if nerve palsy is diagnosed.
From the *Department of Orthopedics and Traumatology, Istanbul University Cerrahpasa Medical Faculty, Istanbul; wDepartment of Orthopedics and Traumatology, Mus¸ State Hospital, Mus¸; and zDepartment of Orthopedics and Traumatology, S¸ırnak State Hospital, S¸ırnak, Turkey. None of the authors received financial support for this study. The authors declare no conflicts of interest. Reprints: I˙lker Abdullah Sarıkaya, MD, Unimed Center, Ferah sok. No: 22 P.C.: 34365 Fulya mh., Sisli, Istanbul, Turkey. E-mail: [email protected]. Copyright r 2014 Wolters Kluwer Health, Inc. All rights reserved.
290 | www.pedorthopaedics.com
Level of Evidence: Level IV. Key Words: supracondylar femoral osteotomy, nerve palsy, neurological complication, cerebral palsy, extension osteotomy, knee flexion contracture (J Pediatr Orthop 2015;35:290–295)
K
nee flexion contracture in children with cerebral palsy (CP) is very common, and functional impairment leads to a crouch gait characterized by a shorter step length and the inability to extend the knee at the swing phase of the gait.1–3 In cases with a severe long-standing crouch, complete correction of the gait pattern cannot be obtained by mere distal hamstring procedures.4,5 In such cases, the correction of the knee flexion contracture and improvement of the gait pattern by supracondylar femoral extension osteotomy seems to be a more effective method.6–8 The use of supracondylar femoral extension osteotomy has shown good results for the treatment of crouch gait. Stout et al7 reported an average of a 15 to 20degree improvement in the total range of knee motion. In 1 group of patients, the supracondylar femoral extension osteotomy allowed enough improvement in the knee flexion contracture, but may lead to some neurological complications.9,10 The lateral surgical exposure of the supracondylar femur or the presence of the posterior bony prominence includes the risk of damaging the neurovascular structures; however, in some patients, the tightening of the neurological structures within the popliteal fossa may occur as a complication of the osteotomy. Nonetheless, only a small number of publications reported the neurological complications of this surgical technique,7,11–13 and in our opinion, the determination of risk factors causing neurological complications after osteotomy may affect the treatment strategy of the knee flexion contracture. This subject has been addressed to identify the risk factors leading to neurological complications after supracondylar femoral extension osteotomy in patients with CP.
METHODS This study included patients operated for knee flexion contracture between 2011 and 2013 who were J Pediatr Orthop
Volume 35, Number 3, April/May 2015
J Pediatr Orthop
Volume 35, Number 3, April/May 2015
Nerve Palsy After Femoral Ostetomy in Cerebral Palsy
reviewed retrospectively after institutional review board approval. Inclusion criteria included patients with a primary diagnosis of CP with rigid knee flexion deformity of 10 to 30 degrees and those who underwent supracondylar femoral osteotomy. Exclusion criteria included patients who had neurological deficiency before the surgery, osteotomies performed primarily for varus or valgus deformities and previous femur fractures. Supracondylar femoral extension osteotomy was performed in 28 patients. The osteotomy was performed bilaterally in 19 patients and unilaterally in 10 patients (total: 48 cases). Neurological complication was not detected in 43 cases (group 1) and detected in 5 cases (group 2), which is reported in Table 1. Patients were classified by the Gross Motor Function Classification System level: 17 patients were classified as level 3, and 11 patients were classified as level 4. The supracondylar femoral extension osteotomy was performed by a single senior surgeon (M.I.), under general anesthesia, and intravenous prophylactic antibiotics were routinely administered. A lateral approach to the distal part of the femur, posterior to the vastus lateralis, was used for the supracondylar femoral extension osteotomy. The periosteum was elevated. An anteriorly based triangular wedge of bone that matched the degree of contracture was removed with an oscillating saw, leaving the posterior cortex intact. The wedge was closed by extending the knee. LCP pediatric condylar 120-degree plate (TST, Istanbul, Turkey) was used to secure osteotomy. The wound was closed. Postoperative immobilization was discussed perioperatively: The knee was immobilized with a brace in slight flexion only for the children with stable fixation and good bony quality. For children whose bones were osteoporotic and achieved stabilization was not enough for early mobilization, the knee was immobilized with a long leg cast. Postoperatively the hip was positioned in extension and hip flexion was limited routinely to avoid sciatic nerve stretch. We used postoperatively intravenous patient-controlled analgesia.
Previous surgical operation, concomitant operations on the same extremity, application of a brace or long leg cast after operation, preoperative and postoperative popliteal angle, amount of correction, and tourniquet time were reviewed. Neurological examination was done preoperatively, postoperatively, and at followup. Examination was performed at time to diagnosis, treatment, and time to recovery in group 2. Radiological data were obtained from preoperative and postoperative antero-posterior and lateral knee radiographs. The amount of correction was measured by using the difference between the preoperative and postoperative physeal posterior distal femoral angles. The physeal posterior distal femoral angle is formed by intersecting the femoral anatomic axis and distal femoral physeal line in the sagittal plane (Fig. 1). Malnutrition was evaluated according to Gomez classification.14 Gomez defined categories of malnutrition: mild, moderate, and severe. The degrees were based on weight below a specified percentage of desired body weight for that age. If a child’s weight is between the 75th and 90th percentile, it is defined as mild malnutrition. If a child’s weight is between the 60th and 74th percentile, it is defined as moderate malnutrition. If a child’s weight is below the 60th percentile of weight for that age, it is defined as severe malnutrition. The emotional states of the children who complained of neurological complications were measured using the State-Trait Anxiety Inventory for Children (STAIC).15 The STAIC consists of two 20-item scales that measure anxiety levels in children. One is the STAIC-S, which asks the subjects to describe how they feel at the present time. The STAIC-T asks the subjects to describe how they generally feel. The total score ranges from 20 to 80 for the 20 questions in each scale. Children with limited communication skills were excluded from the emotional state questionnaire. The correlations were evaluated statistically using SPSS 15 (SPSS Inc., Chicago, IL). The Mann-Whitney
TABLE 1. Clinical Information About Group 2 Patient Age No Patient (y)
Preoperative GMFCS Level
Preoperative Popliteal Amount of Angle Correction
1
AB
13.3
4
35
2
OO
14.6
3
58
3
SCT
13.1
4
32
4
BR
14.1
3
60
5
BU
15.1
3
60
—
Concomitant Surgery PLHT, PMHT, SFEO-O
Tourniquet Previous Operations Time (min)
Supracondylar femoral extension osteotomy 22 (Fig. 2) PA, PMHT, transfer of the tendon of the None posterior tibial muscle for pes cavovarus 11 Plate extraction from supracondylar Supracondylar femur, PLHT femoral osteotomy 19 PA, iliopsoas tenotomy, lateral column Achilloplasty lengthening 24 PLHT, PMHT, patellar tendon None advancement, SFEO-O
— 22 48 60 29
GMFCS indicates Gross Motor Function Classification System; PA, percutaneous achilloplasty; PLHT, percutaneous lateral hamstring tenotomy; PMHT, percutaneous medial hamstring tenotomy; SFEO-O, supracondylar femoral extension osteotomy on the other femur.
Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
www.pedorthopaedics.com |
291
I˙nan et al
J Pediatr Orthop
FIGURE 1. Measurement of the physeal posterior distal femoral angle (pPDFA).
U test was used to compare the differences between the means of the 2 groups. The Fisher exact test was used to compare the categorical variables between the 2 groups and the Pearson test was used for correlation analysis. A P value of 50 degrees we performed hamstring tenotomy. Although the difference was not statistically significant, we determined that more frequent concomitant achilloplasties and hamstring tenotomies were performed in group 2. It should be kept in mind that concomitant achilloplasty and hamstring tenotomy may cause excessive stretching of the neurological structures. Some authors recommend immobilization of the knee at 20 to 30 degrees of flexion in a splint to avoid stretching the neurological structures.11 In our group, 4 of 5 patients who had neurological complication had long leg cast after osteotomy. We strongly suggest using brace in slight flexion after osteotomy. If long leg cast is preferred because of osteoporosis, neurological investigation should be cautiously done. The CPN is a branch of the sciatic nerve, usually arising at the junction of the upper two thirds and lower third of the posterior compartment of the thigh. Asirvatham et al11 proposed that there is no correlation between the incidence of neurological complications and the severity of deformity. Herzenberg et al18 suggested that acute correction of long-standing severe knee flexion contractures is contraindicated in neurologically intact patients, for fear of stretching the sciatic nerve and its branches. Likewise, Stout et al7 suggested that the amount of knee flexion contracture may correlate with nerve palsy, and recommended operating on up to 30-degree knee flexion contractures in CP. We determined a preoperative 46-degree average popliteal angle in group 2, but 53 degrees in group 1. We also found no correlation between the incidence of neurological complications and the severity of deformity. We believed that the CPN was completely under tension, but identification of sensorial impairment was difficult because of understanding difficulties of the patients and this extensive stretch. We identified only in case 1 the CPN with surgical exploration and were able to describe the pathologic involvement level. We analyzed the effect of the amount of correction on neurological complications: 23 degrees of correction was determined in the group 2 and 19 degrees in group 1. In all cases, full passive knee extension was achievable upon intraoperative examination at the end of the surgical procedure. We found no correlation between the incidence of neurological complications and amount of correction. The importance of the posterior bony prominence on neurological structures was emphasized in that it might be a risk factor for nerve palsy. We combined a supracondylar wedge osteotomy with femoral shortening in an intact posterior cortex to minimize stretching injury to the neurological structures. We also detected that Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
J Pediatr Orthop
Volume 35, Number 3, April/May 2015
posterior bony prominence was the cause of hyperesthesia in patient number 3. An intact posterior cortex can be accepted as an obstacle against hyperextension deformity and possible nerve injury. The STAIC was used to evaluate the anxiety level of some children in this study. We observed that a high level of postoperative anxiety is also correlated with difficulty in the recovery of neurological complications. In addition, we observed that malnutrition is an important obstacle to the recovery of neurological complications. Vitamin B12 metabolism can be affected by malnutrition like all systems in an organism. Leishear et al19 reported that deficient B12 status is associated with worse sensory and motor nerve function. Several studies have shown an association between peripheral neuropathy or poor peripheral nerve function and vitamin B12 deficiency.20 Malnutrition can affect the neurological recovery through the vitamin B12 metabolism. In conclusion, after supracondylar femoral extension osteotomy, all patients must be suspected of neurological complication, and measures must be taken to alleviate the stretch at once if nerve palsy is diagnosed. A long leg cast causes obviously high risk for neurological complications. If a neurological complication is detected any brace or cast should be removed, and flexion of the knee should be increased immediately. Posterior bony prominence can cause nerve entrapment and should be controlled intraoperatively and resection is mandatory if it occurs. REFERENCES 1. Lotman DB. Knee flexion deformity and patella alta in spastic cerebral palsy. Dev Med Child Neurol. 1976;18:315–319. 2. Beals RK. Treatment of knee contracture in cerebral palsy by hamstring lengthening, posterior capsulotomy, and quadriceps mechanism shortening. Dev Med Child Neurol. 2001;43: 802–805. 3. Rodda JM, Graham HK, Nattrass GR, et al. Correction of severe crouch gait in patients with spastic diplegia with use of multilevel orthopaedic surgery. J Bone Joint Surg Am. 2006;88:2653–2664. 4. Rutz E, Gaston MS, Camathias C, et al. Distal femoral osteotomy using the LCP pediatric condylar 90-degree plate in patients with neuromuscular disorders. J Pediatr Orthop. 2012;32: 295–300.
Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
Nerve Palsy After Femoral Ostetomy in Cerebral Palsy
5. Joseph B, Reddy K, Varghese RA, et al. Management of severe crouch gait in children and adolescents with cerebral palsy. J Pediatr Orthop. 2010;30:832–839. 6. Healy MT, Schwartz MH, Stout JL, et al. Is simultaneous hamstring lengthening necessary when performing distal femoral extension osteotomy and patellar tendon advancement? Gait Posture. 2011; 33:1–5. 7. Stout JL, Gage JR, Schwartz MH, et al. Distal femoral extension osteotomy and patellar tendon advancement to treat persistent crouch gait in cerebral palsy. J Bone Joint Surg Am. 2008;90: 2470–2484. 8. Novacheck TF, Stout JL, Gage JR, et al. 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):271–286. 9. Zimmerman MH, Smith CF, Oppenheim WL. Supracondylar femoral extension osteotomies in the treatment of fixed flexion deformity of the knee. Clin Orthop Relat Res. 1982;171:87–93. 10. Gage JR. Surgical treatment of knee dysfunction in cerebral palsy. Clin Orthop Relat Res. 1990;253:45–54. 11. Asirvatham R, Mukherjee A, Agarwal S, et al. Supracondylar femoral extension osteotomy: its complications. J Pediatr Orthop. 1993;13:642–645. 12. Bain AM. Treatment of flexion contracture of the knee following poliomyelitis. J Trop Med Hyg. 1966;69:285–290. 13. Leong JCY, Alade CO, Fang D. Supracondylar femoral osteotomy for knee flexion contracture resulting from poliomyelitis. J Bone Joint Surg Br. 1982;64:198–201. 14. Go´mez F, Ramos Galvan R, Frenk S, et al. Mortality in second and third degree malnutrition. 1956. Bull World Health Organ. 2000;78: 1275–1280. 15. Spielberger CD, Gorsuch RL, Lushene RE. Manual for State–Trait Anxiety Inventory (STAI). Palo Alto, CA: Consulting Psychologists Press; 1970. 16. Miller F. Surgical techniques. In: Miller F, ed. Cerebral Palsy. New York: Springer; 2005:865–1024. 17. Mortazavi SM, Heidari P, Esfandiari H, et al. Trapezoid supracondylar femoral extension osteotomy for knee flexion contractures in patients with haemophilia. Haemophilia. 2008;14:85–90. 18. Herzenberg JE, Davis JR, Paley D, et al. Mechanical distraction for treatment of severe knee flexion contractures. Clin Orthop Relat Res. 1994;301:80–88. 19. Leishear K, Boudreau RM, Studenski SA, et al. Health, Aging and Body Composition Study. Relationship between vitamin B12 and sensory and motor peripheral nerve function in older adults. J Am Geriatr Soc. 2012;60:1057–1063. 20. Strotmeyer ES, de Rekeneire N, Schwartz AV, et al. The relationship of reduced peripheral nerve function and diabetes with physical performance in older white and black adults: the Health, Aging, and Body Composition (Health ABC) study. Diabetes Care. 2008;31: 1767–1772.
www.pedorthopaedics.com |
295
Neurological Complications After Supracondylar Femoral Osteotomy in Cerebral Palsy Muharrem I˙nan, MD,* I˙lker Abdullah Sarıkaya, MD,w Enis Yıldırım, MD,z and Mehmet Fatih Gu¨ven, MD*
Background: Knee flexion contracture in children with cerebral palsy (CP) is very common and functional impairment leads to a crouch gait. Correction of the knee flexion contracture and improvement of the gait pattern by supracondylar femoral extension osteotomy seems to be a more effective method than distal hamstring procedures in long-standing severe crouch. Only a small number of publications reported the neurological complications of this surgical technique. This study was planned to identify the risk factors leading to neurological complications after supracondylar femoral extension osteotomy in patients with CP. Methods: Supracondylar femoral osteotomies performed for a primary diagnosis of CP with rigid knee flexion deformity of 10 to 30 degrees were included in the study. Supracondylar femoral extension osteotomy was performed in 28 patients (total: 48 cases). Neurological complication was not detected in 43 cases (group 1) and detected in 5 cases (group 2). Previous surgical operation, concomitant operations on the same extremity, application of a brace or long leg cast after operation, preoperative and postoperative popliteal angle, amount of correction, radiologic correction, tourniquet time, level of malnutrition, and emotional state were reviewed. Results: There were 18 boys and 10 girls. The mean age was 12 ± 4 years in group 1 and 13 ± 1 years in group 2. Except 6 patients, all patients had concomitant operations (38 cases in group 1 and 4 cases in group 2). Postoperatively, long leg cast was used in 38 cases and brace in 10 cases. In group 1 mean correction was 23 ± 3.8 degrees and in group 2 it was 19 ± 5.7 degrees. Conclusions: Correlation was not found between the incidence of neurological complications and amount of correction and deformity. After supracondylar femoral extension osteotomy, all patients must be suspected of neurological complication, and measures taken to alleviate the stretch at once if nerve palsy is diagnosed.
From the *Department of Orthopedics and Traumatology, Istanbul University Cerrahpasa Medical Faculty, Istanbul; wDepartment of Orthopedics and Traumatology, Mus¸ State Hospital, Mus¸; and zDepartment of Orthopedics and Traumatology, S¸ırnak State Hospital, S¸ırnak, Turkey. None of the authors received financial support for this study. The authors declare no conflicts of interest. Reprints: I˙lker Abdullah Sarıkaya, MD, Unimed Center, Ferah sok. No: 22 P.C.: 34365 Fulya mh., Sisli, Istanbul, Turkey. E-mail: [email protected]. Copyright r 2014 Wolters Kluwer Health, Inc. All rights reserved.
290 | www.pedorthopaedics.com
Level of Evidence: Level IV. Key Words: supracondylar femoral osteotomy, nerve palsy, neurological complication, cerebral palsy, extension osteotomy, knee flexion contracture (J Pediatr Orthop 2015;35:290–295)
K
nee flexion contracture in children with cerebral palsy (CP) is very common, and functional impairment leads to a crouch gait characterized by a shorter step length and the inability to extend the knee at the swing phase of the gait.1–3 In cases with a severe long-standing crouch, complete correction of the gait pattern cannot be obtained by mere distal hamstring procedures.4,5 In such cases, the correction of the knee flexion contracture and improvement of the gait pattern by supracondylar femoral extension osteotomy seems to be a more effective method.6–8 The use of supracondylar femoral extension osteotomy has shown good results for the treatment of crouch gait. Stout et al7 reported an average of a 15 to 20degree improvement in the total range of knee motion. In 1 group of patients, the supracondylar femoral extension osteotomy allowed enough improvement in the knee flexion contracture, but may lead to some neurological complications.9,10 The lateral surgical exposure of the supracondylar femur or the presence of the posterior bony prominence includes the risk of damaging the neurovascular structures; however, in some patients, the tightening of the neurological structures within the popliteal fossa may occur as a complication of the osteotomy. Nonetheless, only a small number of publications reported the neurological complications of this surgical technique,7,11–13 and in our opinion, the determination of risk factors causing neurological complications after osteotomy may affect the treatment strategy of the knee flexion contracture. This subject has been addressed to identify the risk factors leading to neurological complications after supracondylar femoral extension osteotomy in patients with CP.
METHODS This study included patients operated for knee flexion contracture between 2011 and 2013 who were J Pediatr Orthop
Volume 35, Number 3, April/May 2015
J Pediatr Orthop
Volume 35, Number 3, April/May 2015
Nerve Palsy After Femoral Ostetomy in Cerebral Palsy
reviewed retrospectively after institutional review board approval. Inclusion criteria included patients with a primary diagnosis of CP with rigid knee flexion deformity of 10 to 30 degrees and those who underwent supracondylar femoral osteotomy. Exclusion criteria included patients who had neurological deficiency before the surgery, osteotomies performed primarily for varus or valgus deformities and previous femur fractures. Supracondylar femoral extension osteotomy was performed in 28 patients. The osteotomy was performed bilaterally in 19 patients and unilaterally in 10 patients (total: 48 cases). Neurological complication was not detected in 43 cases (group 1) and detected in 5 cases (group 2), which is reported in Table 1. Patients were classified by the Gross Motor Function Classification System level: 17 patients were classified as level 3, and 11 patients were classified as level 4. The supracondylar femoral extension osteotomy was performed by a single senior surgeon (M.I.), under general anesthesia, and intravenous prophylactic antibiotics were routinely administered. A lateral approach to the distal part of the femur, posterior to the vastus lateralis, was used for the supracondylar femoral extension osteotomy. The periosteum was elevated. An anteriorly based triangular wedge of bone that matched the degree of contracture was removed with an oscillating saw, leaving the posterior cortex intact. The wedge was closed by extending the knee. LCP pediatric condylar 120-degree plate (TST, Istanbul, Turkey) was used to secure osteotomy. The wound was closed. Postoperative immobilization was discussed perioperatively: The knee was immobilized with a brace in slight flexion only for the children with stable fixation and good bony quality. For children whose bones were osteoporotic and achieved stabilization was not enough for early mobilization, the knee was immobilized with a long leg cast. Postoperatively the hip was positioned in extension and hip flexion was limited routinely to avoid sciatic nerve stretch. We used postoperatively intravenous patient-controlled analgesia.
Previous surgical operation, concomitant operations on the same extremity, application of a brace or long leg cast after operation, preoperative and postoperative popliteal angle, amount of correction, and tourniquet time were reviewed. Neurological examination was done preoperatively, postoperatively, and at followup. Examination was performed at time to diagnosis, treatment, and time to recovery in group 2. Radiological data were obtained from preoperative and postoperative antero-posterior and lateral knee radiographs. The amount of correction was measured by using the difference between the preoperative and postoperative physeal posterior distal femoral angles. The physeal posterior distal femoral angle is formed by intersecting the femoral anatomic axis and distal femoral physeal line in the sagittal plane (Fig. 1). Malnutrition was evaluated according to Gomez classification.14 Gomez defined categories of malnutrition: mild, moderate, and severe. The degrees were based on weight below a specified percentage of desired body weight for that age. If a child’s weight is between the 75th and 90th percentile, it is defined as mild malnutrition. If a child’s weight is between the 60th and 74th percentile, it is defined as moderate malnutrition. If a child’s weight is below the 60th percentile of weight for that age, it is defined as severe malnutrition. The emotional states of the children who complained of neurological complications were measured using the State-Trait Anxiety Inventory for Children (STAIC).15 The STAIC consists of two 20-item scales that measure anxiety levels in children. One is the STAIC-S, which asks the subjects to describe how they feel at the present time. The STAIC-T asks the subjects to describe how they generally feel. The total score ranges from 20 to 80 for the 20 questions in each scale. Children with limited communication skills were excluded from the emotional state questionnaire. The correlations were evaluated statistically using SPSS 15 (SPSS Inc., Chicago, IL). The Mann-Whitney
TABLE 1. Clinical Information About Group 2 Patient Age No Patient (y)
Preoperative GMFCS Level
Preoperative Popliteal Amount of Angle Correction
1
AB
13.3
4
35
2
OO
14.6
3
58
3
SCT
13.1
4
32
4
BR
14.1
3
60
5
BU
15.1
3
60
—
Concomitant Surgery PLHT, PMHT, SFEO-O
Tourniquet Previous Operations Time (min)
Supracondylar femoral extension osteotomy 22 (Fig. 2) PA, PMHT, transfer of the tendon of the None posterior tibial muscle for pes cavovarus 11 Plate extraction from supracondylar Supracondylar femur, PLHT femoral osteotomy 19 PA, iliopsoas tenotomy, lateral column Achilloplasty lengthening 24 PLHT, PMHT, patellar tendon None advancement, SFEO-O
— 22 48 60 29
GMFCS indicates Gross Motor Function Classification System; PA, percutaneous achilloplasty; PLHT, percutaneous lateral hamstring tenotomy; PMHT, percutaneous medial hamstring tenotomy; SFEO-O, supracondylar femoral extension osteotomy on the other femur.
Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
www.pedorthopaedics.com |
291
I˙nan et al
J Pediatr Orthop
FIGURE 1. Measurement of the physeal posterior distal femoral angle (pPDFA).
U test was used to compare the differences between the means of the 2 groups. The Fisher exact test was used to compare the categorical variables between the 2 groups and the Pearson test was used for correlation analysis. A P value of 50 degrees we performed hamstring tenotomy. Although the difference was not statistically significant, we determined that more frequent concomitant achilloplasties and hamstring tenotomies were performed in group 2. It should be kept in mind that concomitant achilloplasty and hamstring tenotomy may cause excessive stretching of the neurological structures. Some authors recommend immobilization of the knee at 20 to 30 degrees of flexion in a splint to avoid stretching the neurological structures.11 In our group, 4 of 5 patients who had neurological complication had long leg cast after osteotomy. We strongly suggest using brace in slight flexion after osteotomy. If long leg cast is preferred because of osteoporosis, neurological investigation should be cautiously done. The CPN is a branch of the sciatic nerve, usually arising at the junction of the upper two thirds and lower third of the posterior compartment of the thigh. Asirvatham et al11 proposed that there is no correlation between the incidence of neurological complications and the severity of deformity. Herzenberg et al18 suggested that acute correction of long-standing severe knee flexion contractures is contraindicated in neurologically intact patients, for fear of stretching the sciatic nerve and its branches. Likewise, Stout et al7 suggested that the amount of knee flexion contracture may correlate with nerve palsy, and recommended operating on up to 30-degree knee flexion contractures in CP. We determined a preoperative 46-degree average popliteal angle in group 2, but 53 degrees in group 1. We also found no correlation between the incidence of neurological complications and the severity of deformity. We believed that the CPN was completely under tension, but identification of sensorial impairment was difficult because of understanding difficulties of the patients and this extensive stretch. We identified only in case 1 the CPN with surgical exploration and were able to describe the pathologic involvement level. We analyzed the effect of the amount of correction on neurological complications: 23 degrees of correction was determined in the group 2 and 19 degrees in group 1. In all cases, full passive knee extension was achievable upon intraoperative examination at the end of the surgical procedure. We found no correlation between the incidence of neurological complications and amount of correction. The importance of the posterior bony prominence on neurological structures was emphasized in that it might be a risk factor for nerve palsy. We combined a supracondylar wedge osteotomy with femoral shortening in an intact posterior cortex to minimize stretching injury to the neurological structures. We also detected that Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
J Pediatr Orthop
Volume 35, Number 3, April/May 2015
posterior bony prominence was the cause of hyperesthesia in patient number 3. An intact posterior cortex can be accepted as an obstacle against hyperextension deformity and possible nerve injury. The STAIC was used to evaluate the anxiety level of some children in this study. We observed that a high level of postoperative anxiety is also correlated with difficulty in the recovery of neurological complications. In addition, we observed that malnutrition is an important obstacle to the recovery of neurological complications. Vitamin B12 metabolism can be affected by malnutrition like all systems in an organism. Leishear et al19 reported that deficient B12 status is associated with worse sensory and motor nerve function. Several studies have shown an association between peripheral neuropathy or poor peripheral nerve function and vitamin B12 deficiency.20 Malnutrition can affect the neurological recovery through the vitamin B12 metabolism. In conclusion, after supracondylar femoral extension osteotomy, all patients must be suspected of neurological complication, and measures must be taken to alleviate the stretch at once if nerve palsy is diagnosed. A long leg cast causes obviously high risk for neurological complications. If a neurological complication is detected any brace or cast should be removed, and flexion of the knee should be increased immediately. Posterior bony prominence can cause nerve entrapment and should be controlled intraoperatively and resection is mandatory if it occurs. REFERENCES 1. Lotman DB. Knee flexion deformity and patella alta in spastic cerebral palsy. Dev Med Child Neurol. 1976;18:315–319. 2. Beals RK. Treatment of knee contracture in cerebral palsy by hamstring lengthening, posterior capsulotomy, and quadriceps mechanism shortening. Dev Med Child Neurol. 2001;43: 802–805. 3. Rodda JM, Graham HK, Nattrass GR, et al. Correction of severe crouch gait in patients with spastic diplegia with use of multilevel orthopaedic surgery. J Bone Joint Surg Am. 2006;88:2653–2664. 4. Rutz E, Gaston MS, Camathias C, et al. Distal femoral osteotomy using the LCP pediatric condylar 90-degree plate in patients with neuromuscular disorders. J Pediatr Orthop. 2012;32: 295–300.
Copyright
r
2014 Wolters Kluwer Health, Inc. All rights reserved.
Nerve Palsy After Femoral Ostetomy in Cerebral Palsy
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