|Year : 2020 | Volume
| Issue : 2 | Page : 153-158
Limb lengthening in down syndrome
Christopher A Iobst
Department of Orthopedic Surgery, Nationwide Children's Hospital, Columbus, OH, USA
|Date of Submission||13-Oct-2020|
|Date of Decision||09-Dec-2020|
|Date of Acceptance||10-Dec-2020|
|Date of Web Publication||31-Dec-2020|
Dr. Christopher A Iobst
Department of Orthopedic Surgery, Nationwide Children's Hospital, 700 Children's Drive Suite A2630, Columbus, Ohio 43205-2696
Source of Support: None, Conflict of Interest: None
Introduction: The average life expectancy for Down syndrome patients has markedly improved. Musculoskeletal disorders occur in 20%–27% of patients with Down syndrome, with hip or knee instability among the most common presentations. Leg length discrepancy has rarely been reported in Down syndrome but can occur as the result of previous lower extremity surgery. This case report presents our experience with the first documented use of an intramedullary lengthening nail to correct a 4.5 cm iatrogenic leg length discrepancy in a skeletally mature Down syndrome patient. Materials and Methods: A single patient surgically treated for leg length discrepancy was followed over a 1-year period and retrospectively reviewed. Results: An 17-year-old male with Down syndrome presented with a 4.5 cm leg length discrepancy secondary to a previously attempted hip fusion. He had been treated with a shoe lift but had difficulty walking with the lift and resorted to toe walking whenever the lift was not being used. His mother, who was his full-time caregiver, was interested in surgical options for permanently correcting his discrepancy. After long discussions over multiple visits covering the risks and benefits of the various choices, the decision to proceed with lengthening of the short limb using a retrograde femoral intramedullary lengthening nail was made. Distraction osteogenesis of 4.5 cm with full consolidation was achieved in this patient without complications. He was able to return to full independent ambulation without a lift by 4 months. Conclusion: Limb lengthening requires a detailed postoperative protocol that may appear to be difficult for a Down syndrome patient with cognitive developmental delay to manage. However, this report documents that if the patient has a reliable caregiver and close postoperative monitoring is maintained, a successful outcome is possible. This represents the first published case of limb lengthening in a Down syndrome patient.
Keywords: Down syndrome, leg length discrepancy, limb lengthening
|How to cite this article:|
Iobst CA. Limb lengthening in down syndrome. J Limb Lengthen Reconstr 2020;6:153-8
| Introduction|| |
Down syndrome, first described by John Langdon Down, in 1866, is considered the most common chromosomal abnormality in humans. With the marked improvement in life expectancy for individuals with Down syndrome, many actively engage in employment and sports.,,, Since musculoskeletal disorders occur in 20%–27% of patients with Down syndrome, orthopedic management strategies should aim to preserve long term function., Hip instability due to capsular laxity, increased external rotation, and acetabular dysplasia can be a particularly difficult problem., While recent hip reconstruction methods have demonstrated improved results, hip fusion is still sometimes necessary as a salvage procedure.
Limb length inequality has not been noted to be a common finding in patients with Down syndrome. However, iatrogenic leg length discrepancy can occur, especially after unilateral hip procedures. Large discrepancies are possible if the proximal femoral physis is affected at a young age or in cases where a hip fusion is required. Since the postoperative course for limb lengthening can be complicated, especially when using an external fixator, conservative management with shoe lifts has been the most common management recommendation in these patients. This report represents the first documented case of limb lengthening in a Down syndrome patient using an intramedullary lengthening nail. Informed consent was obtained for publication of the details of the case.
| Case Report|| |
The patient was a 17-year-old male with Down syndrome who presented with a leg length discrepancy. His previous orthopedic history was significant for a right innominate pelvic osteotomy at the age of 10 years for whole head involvement Perthes disease followed by a right proximal femoral varus osteotomy at the age of 11 years. Unfortunately, he developed marked right degenerative disease to the hip, causing pain that interfered with his ability to ambulate. He underwent a hip fusion at the age of 15 years. The hip was placed in 10° of flexion with slight abduction and neutral rotation by the surgeon.
He initially presented to our center for limb lengthening and reconstruction at the age of 17 years. At that time, his leg length discrepancy was being managed by a 3 cm lift under his right shoe. His mother stated that he was walking on his right toe whenever he was not wearing the lift. She was concerned that his gait was getting worse with time.
On physical examination, he was a very pleasant young man and was able to follow commands without difficulty. He was able to walk independently up and down the clinic hallway but demonstrated a toe–toe type of gait on the right with a plantigrade foot position on the left. He was also demonstrating accentuated lumbar lordosis with his gait, most likely secondary to his stiff right hip. In a supine position, he demonstrated approximately 0–30° of hip flexion. He had essentially no rotation or abduction/adduction of the right hip. The right knee was ligamentous stable and had full flexion and extension. Despite his toe walking, the right foot could be dorsiflexed to neutral without difficulty. No genu varum or genu valgum was appreciated clinically.
Standing radiographs were obtained with a 5 cm block under his right foot [Figure 1]. This size block slightly overcorrected his deformity, giving him a 4.5 cm length discrepancy with the left lower extremity longer than the right. He had symmetric mechanic axis lines passing just medial to neutral on each limb. He was skeletally mature. The discrepancy was primarily involving the right femur, as expected. Dedicated anteroposterior and lateral views of the right femur demonstrated no additional deformity in the femoral diaphysis or distal metaphysis. The anterior hip fusion plate was noted to be broken which explained his small amount of hip flexion on physical examination.
|Figure 1: Preoperative standing anteroposterior bilateral lower extremity radiograph with a 5 cm block under the right foot. His mechanical axis of each limb is slightly medial to neutral. Hardware from previous right hip fusion surgery is visible|
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Several long discussions with the patient's mother, who was the primary caregiver, ensued to outline the management options. She preferred to discontinue the shoe lift since he had so much trouble walking with it. She was concerned about the option of shortening the left femur since this was his good limb and it could potentially make him weaker. The potential risks and benefits of lengthening his right femur using a retrograde intramedullary lengthening nail were discussed at length. The benefits included restoring his original femoral length, providing a permanent correction of his leg lengths, restoring bone stock for his planned revision hip surgery, and avoiding an external fixator in a patient with cognitive developmental delay. The major concern of the lengthening option was the calculated risk involved in expecting a patient with cognitive developmental delay to comply with the required postoperative protocol. While he was a docile and obedient young man, he had moderate cognitive impairment and required consistent supervision. It was understood that lengthening would require weekly follow-up appointments during the distraction phase and daily range of motion exercises. We discussed that the lengthening would be slowed or stopped if there was any issue with bone formation or loss of knee joint range of motion. He would need to sleep in a dynamic knee extension brace to help maintain knee extension during the lengthening. It was also explained that the patient would have a limited weight-bearing for approximately 4 months. Based on his docile and obedient personality, his mother felt comfortable that he would follow directions. She would also be available full time to supervise him during the postoperative course. After careful consideration of the different choices, his mother elected to proceed with the retrograde femoral lengthening. Based on his preoperative radiographs and physical examination, the plan was to insert the nail in a neutral position without performing any acute corrections. Since intramedullary nails lengthen along the anatomic axis, his slightly medial preoperative mechanical axis line was expected to move toward neutral. To limit the amount of surgery to the limb at one time, the revision of the hip hardware was to wait until after the lengthening process was completed.
A standard intramedullary lengthening nail surgical procedure was performed involving the following steps: (1) the templated nail length is measured on the skin with the radiographic ruler to make sure it is appropriate; (2) the proximal extent of reaming and the proposed osteoplasty site (distal femoral metaphysis) are marked on the skin; (3) the venting holes are percutaneously drilled at the proposed osteoplasty site; (4) a medial parapatellar approach to the knee joint is performed with the knee flexed over a bump; (5) the guide wire and entry reamer are inserted into the distal femur under fluoroscopic guidance; (6) the ball-tipped guide wire is passed into the center of the femoral canal and advanced just past the marked proximal extent of reaming; (7) the canal is reamed 2 mm over the diameter of the chosen nail size; (8) the ball-tipped guide wire is removed and the nail is inserted by hand up to the venting holes; (9) the percutaneous osteoplasty is finished by connecting the drill holes using an osteotome (confirm it is complete); (10) pass the nail to the appropriate depth proximally and distally by hand (A 190 × 8.5 retrograde universal Precice femoral nail was inserted in this patient); (11) insert the proximal and distal interlocking pegs making sure the rotation is correct [Figure 2]; (12) mark the location of the magnet on the skin; (13) test the nail function by lengthening 1 mm acutely; (14) irrigate and close the incisions; and (15) prior to awakening from general anesthesia, a suprainguinal fascia iliaca peripheral nerve catheter was placed by the regional anesthesia team.
|Figure 2: Intraoperative anteroposterior femur fluoroscopy image demonstrating the metaphyseal osteotomy and intramedullary lengthening nail placement|
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After surgery, he was admitted overnight to the orthopedic inpatient unit. The following morning, he participated in physical therapy where mobilization and gait training were reviewed. Because he was comfortable and had passed his physical therapy requirements, he was discharged home later that same day with his portable nerve catheter unit. His dynamic knee extension brace was delivered while in the hospital for immediate home use 12–16 h/day. His discharge instructions included (1) touch-down weight-bearing only with the assistance of a walker and (2) daily range of motion and strengthening exercises for his right lower extremity.
He returned to the clinic on postoperative day #5 where his nerve catheter and surgical dressings were removed, he received physical therapy, and the family was educated on the use of the external remote controller. He began lengthening sessions at home the following day for a total latency period of 6 days. His initial rate and rhythm for the distraction were set at 1 mm/day divided into four 0.25 mm increments. He was seen in the office on a weekly basis throughout the distraction phase (7 weeks). At each visit, he had a physical examination and standard orthogonal radiographs of the right femur and he received a physical therapy session to review his weight-bearing restrictions and his daily range of motion exercises. The radiographs demonstrated consistently excellent regenerate bone formation such that we did not need to adjust his rate and rhythm during the entire distraction phase. He did not require any narcotic pain medication throughout the duration of his recovery and only occasionally needed acetaminophen. He was able to comply with the touch-down weight-bearing restrictions throughout his distraction phase while independently ambulating with a walker. He maintained his knee range of motion from 0° to 90° throughout the distraction phase until the last visit (week 7) when it was noted to have decreased to 10°–70°. At that point, he had achieved his lengthening goal (4.5 cm) and he entered the consolidation phase [Figure 3]a and [Figure 3]b. His right knee range of motion gradually improved back to the full 0°–135° arc over the next 3 months. During the consolidation phase, he had monthly radiographs to assess the healing of the regeneration. Based on those evaluations, his weight-bearing was gradually increased from touchdown to partial to as tolerated over the next 3 months. At 4 months after surgery, he was walking fully weight-bearing and considered to be fully consolidated [Figure 4]a and [Figure 4]b. During gait, he was able to maintain a plantigrade foot and no longer required a shoe lift. He was able to compete in swimming at the special olympics 6 months after surgery [Figure 5]a and [Figure 5]b. Radiographs at 1 year after surgery demonstrated a level pelvis, neutral mechanical axis, and fully consolidated regenerate bone [Figure 6]. He was scheduled for nail removal at that time.
|Figure 3: (a) Anteroposterior radiograph of the femur at the end of distraction. (b) Lateral radiograph of the femur at the end of distraction|
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|Figure 4: (a) Anteroposterior radiograph of the femur 4 months after surgery. (b) Lateral radiograph of the femur 4 months after surgery. Based on the healing of the regeneration, he was released to full weight-bearing at this time|
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|Figure 5: (a) Anteroposterior radiograph of the femur 6 months after surgery. (b) Lateral radiograph of the femur 6 months after surgery. He was released to sports activities (Special Olympics) at this time|
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|Figure 6: Standing anteroposterior bilateral lower extremity radiograph 12 months after surgery. The pelvis is balanced without a shoe lift and his mechanical axis has been corrected to neutral|
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| Discussion|| |
Modern intramedullary limb lengthening nails have revolutionized the field of limb lengthening. Since the entire process can occur internally with this technique, patients find the experience to be more comfortable than lengthening with an external fixator. In addition, the absence of pins and wires traversing the soft-tissue envelope allows patients to maintain range of motion easier and avoid the nuisance of pin site infections. Recent publications have demonstrated the accuracy and reliability of lengthening with the current intramedullary lengthening nails.,,,,, As experience with the devices has increased, the indications for use have gradually expanded. Surgeons have successfully utilized intramedullary lengthening nails in patients with a variety of conditions including Ollier's disease, osteogenesis imperfecta, fibrous dysplasia, and bone cysts.,,
To our knowledge, limb lengthening in Down syndrome has never been described in the literature. The only known report of distraction osteogenesis in Down syndrome involves cases of mandibular distraction for obstructive sleep apnea. Lower extremity orthopedic surgery for patients with Down syndrome, however, has been well described in the literature.,,,,, Reconstruction for hip or patella instability are among the most commonly reported lower limb surgeries in Down syndrome patients. Historically, Down syndrome patients were primarily managed conservatively since it was thought that the need for mobility was less essential than the general population due to their short life expectancy and lifestyle limitations. More recent studies have debunked that assumption and report significant increases in life expectancy and activity levels for Down syndrome patients.,,, Mobility, in addition to active participation in sports, is recognized as a major predictor of survival.
Despite the associated cognitive developmental delay, successful outcomes in Down syndrome patients have been observed in orthopedic procedures, such as total hip arthroplasty, that require postoperative weight-bearing restrictions and physical therapy. Consequently, we felt comfortable to discuss the process of limb lengthening with this patient and his family. Limb lengthening was an appropriate option given the substantial difficulties he was having ambulating with the large shoe lift and the need to toe walk without the lift. He was also going to need further hip surgery due to his ipsilateral failed hip fusion. Establishing more equalized limb lengths would decrease the stress placed on any subsequent attempt at hip fusion and would provide increased femoral bone stock for potential future conversion to a total hip arthroplasty.
We felt that there were several advantages to using an intramedullary lengthening nail rather than an external fixator in this at-risk patient. The intramedullary lengthening nail would simplify his postoperative course by avoiding the discomfort and positioning difficulties inherent in wearing a fixator on the femur. Since the nail would be an internal device, it would make it easier for him to balance and ambulate with the walker and to participate in a daily range of motion exercises. The nail would also eliminate the concern for pin site infections that could complicate a future conversion to a total hip arthroplasty. There was also concern that he might try to self-adjust the distraction mechanism on the frame and create problems with maintaining a consistent lengthening rate and rhythm. Finally, since he had a stable knee, full knee range of motion, and no patellar instability issues, the internal femoral lengthening did not require any additional preparatory surgery.
While there is risk in attempting an intramedullary limb lengthening for a Down syndrome patient, this case demonstrates that it can be accomplished safely with the appropriate precautions in place. Our patient had an available full-time caregiver to supervise and assist with his postoperative regimen. Under his caregiver's direction, he was able to comply with the recommended weight-bearing restrictions and maintain an adequate range of motion during distraction. Weekly clinic visits during the distraction phase allowed close monitoring of his progress. He was able to achieve his lengthening goal of 4.5 cm. During the consolidation period, he was able to gradually increase his weight-bearing and regain full range of motion of his right knee. Radiographically, the regenerated bone formed and consolidated appropriately and without complication allowing him to return to full weight-bearing at 4 months. By lengthening along the anatomic axis, correction of his preoperative medial deviation of the mechanical axis to a neutral mechanical axis occurred. By 6 months after surgery, he was back to participating in the Special Olympics and being Honored at Tim Tebow's Night to Shine. His family was impressed with how smooth the lengthening process transpired and they were thrilled with his final result.
In summary, this case report represents the first documented case of limb lengthening in a Down syndrome patient. With a careful patient selection, distraction osteogenesis using an intramedullary lengthening nail can expect to have a successful outcome similar to a non-Down syndrome patient.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Caird MS, Wills BP, Dormans JP. Down syndrome in children: The role of the orthopedic surgeon. J Am Acad Orthop Surg 2006;14:610-9.
Mik G, Gholve PA, Scher DM, Widmann RF, Green DW. Down syndrome: Orthopedic issues. Curr Opin Pediatr 2008;20:30-6.
Eyman RK, Call TL. Life expectancy of persons with Down syndrome. Am J Ment Retard 1991;95:603-12.
Yang Q, Rasmussen SA, Friedman JM. Mortality associated with Down's syndrome in the USA from 1983 to 1997: A population based study. Lancet 2002;359:1019-25.
Winell J, Burke SW. Sports participation of children with down syndrome. Orthop Clin North Am 2003;34:439-43.
Diamond LS, Lynne D, Sigman B. Orthopedic disorders in patients with Down's syndrome. Orthop Clin North Am 1981;12:57-71.
Abousamra O, Bayhan IA, Rogers KJ, Miller F. Hip instability in Down syndrome: A Focus on acetabular retroversion. J Pediatr Orthop 2016;36:499-504.
Landge V, Shabtai L, Gesheff M, Specht SC, Herzenberg JE. Patient satisfaction after limb lengthening with internal and external devices. J Surg Orthop Adv 2015;24:174-9.
Szymczuk VL, Hammouda AI, Gesheff MG, Standard SC, Herzenberg JE. Lengthening with monolateral external fixation versus magnetically motorized intramedullary nail in congenital femoral deficiency. J Pediatr Orthop 2019;39:458-65.
Kirane YM, Fragomen AT, Rozbruch SR. Precision of the PRECICE internal bone lengthening nail. Clin Orthop Relat Res 2014;472:3869-78.
Paley D, Harris M, Debiparshad K, Prince D. Limb lengthening by implantable limb lengthening devices. Tech Orthop 2014;29:72-85.
Baumgart R, Betz A, Schweiberer L. A fully implantable motorized intramedullary nail for limb lengthening and bone transport. Clin Orthop Relat Res 1997;343:135-43.
Singh S, Lahiri A, Iqbal M. The results of limb lengthening by callus distraction using an extending intramedullary nail (Fitbone) in non-traumatic disorders. J Bone Joint Surg Br 2006;88:938-42.
Krieg AH, Lenze U, Speth BM, Hasler CC. Intramedullary leg lengthening with a motorized nail. Acta Orthop 2011;82:344-50.
Dinçyürek H, Kocaoğlu M, Eralp IL, Bilen FE, Dikmen G, Eren I, et al.
Functional results of lower extremity lengthening by motorized intramedullary nails. Acta Orthop Traumatol Turc 2012;46:42-9.
Acan AE, Basci O, Havitcioglu H. Aneurysmal bone cyst healing response with intramedullary lengthening nail. Acta Orthop Traumatol Turc 2018;52:232-5.
Baumgart R, Burklein D, Hinterwimmer S, Thaller P, Mutschler W. The management of leg length discrepancy in Ollier's disease with a fully implantable lengthening nail. J Bone Joint Surg Br 2005;87:1000-4.
Karakoyun O, Sokucu S, Erol MF, Kucukkaya M, Kabukcuoglu YS. Use of a magnetic bone nail for lengthening of the femur and tibia. J Orthop Surg 2016;24:374-8.
Miloro M. Mandibular distraction osteogenesis for pediatric airway management. J Oral Maxillofac Surg 2010;68:1512-23.
Orozco M, Abousamra O, Chen BP, Rogers KJ, Sees JP, Miller F. Knee deformities in children with Down syndrome: A focus on knee malalignment. J Pediatr Orthop 2018;38:266-73.
Perotti LR, Abousamra O, del Pilar Duque Orozco M, Rogers KJ, Sees JP, Miller F. Foot and ankle de-fomities in children with Down syndrome. J Child Orthop 2018;12:218-26.
Kosashvili Y, Taylor D, Backstein, D, Safir O, Gross A, Lakstein D. Total hip arthroplasty in patients with Down syndrome. Orthopedics 2010;33:629.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]