|Year : 2017 | Volume
| Issue : 1 | Page : 12-16
Supracondylar “V” osteotomy for postrachitic genu valgum in children: A case series
Anil Agarwal, Abbas Shaharyar
Department of Paediatric Orthopaedics, Chacha Nehru Bal Chikitsalaya, New Delhi, India
|Date of Web Publication||29-May-2017|
4/103, East End Apartments, Mayur Vihar Phase-1 Extension, New Delhi - 110 096
Source of Support: None, Conflict of Interest: None
Objectives: Among the various options available for correction of genu valgum deformities, supracondylar “V” osteotomy is a sparsely used technique. We used the technique for correction of postrachitic deformity in late childhood and adolescence and report the outcome achieved. Patients and Methods: Our operative criteria were age range between 10 and 12 years, a normal metabolic profile, and genu valgum deformity with a standing radiological tibiofemoral angle ≥15°. Patients who had gross collateral ligament instability, any restriction of knee range of motion, genu recurvatum, predominant tibial deformity component, epiphyseal irregularities, active metabolic disease were excluded from the study. Correction was undertaken using “V” osteotomy technique described by Aglietti et al. and was stabilized by two Kirschner wires. Functional outcome was assessed using Böstman et al. score. Results: Seventeen limbs in nine patients with a mean age of 11 years were operated. All the genu valgum deformities were postrachitic but with healed status. Mean follow-up of patients was 24.8 months. Preoperative radiological tibio-femoral angle had a mean value of 20.2° which improved to a mean of 3.05° postoperatively. Knee score was excellent in 88.8%, good in 11.1%. All patients recovered full range of knee motion within 6 weeks after removal of the cast. Two main complications were deep infection and partial slippage of lower femoral physis in one case each. Conclusions: Supracondylar “V” osteotomy is a viable option for the correction of postrachitic genu valgum deformity in older children and adolescents with limited residual physeal growth not amenable to growth modulation procedures.
Keywords: Adolescence, children, deformity, genu valgum, osteotomy
|How to cite this article:|
Agarwal A, Shaharyar A. Supracondylar “V” osteotomy for postrachitic genu valgum in children: A case series. J Orthop Traumatol Rehabil 2017;9:12-6
|How to cite this URL:|
Agarwal A, Shaharyar A. Supracondylar “V” osteotomy for postrachitic genu valgum in children: A case series. J Orthop Traumatol Rehabil [serial online] 2017 [cited 2018 Jun 23];9:12-6. Available from: http://www.jotr.in/text.asp?2017/9/1/12/207166
| Introduction|| |
Postrachitic genu valgum is a common deformity seen in late childhood in low-income countries. The deformity usually originates from distal femur; although, they may well have other components as well., When the valgus deformity is significant, it needs to be corrected surgically. For a child, especially females, with less time remaining for physeal closure, growth modulation is usually not a predictable option. The other common procedures described in the literature for this age group are supracondylar opening or closing wedge/dome osteotomy or distraction osteosynthesis using monolateral and ring external fixators.,,, The options listed pose shortcomings such as prolonged immobilization, use of bulky, and costly implants violating a potentially viable physeal plate and risk of knee stiffness., Aglietti et al. originally described a distal femoral wedgeless “V” osteotomy for genu valgum deformity secondary to lateral compartment osteoarthritis in adults. The technique involves correction by an inherently stable wedgeless extraarticular osteotomy based on medial penetration of a “V-shaped proximal fragment. Its use has been gradually extended for correction of genu valgum deformity in adolescents and young adults., We herein describe our experience with this relatively lesser known osteotomy for correction of genu valgum deformities in postrachitic children.
| Patients and Methods|| |
We retrospectively studied 17 limbs with genu valgum sequelae deformities secondary to healed rickets. These were operated using the Aglietti's “V” osteotomy during a span of 2 years (2012–2013). Patient and guardian consent was obtained for reporting the results and clinical photographs. Our operative criteria were age range between 10 and 12 years, a normal metabolic profile (postrachitic treatment), and genu valgum deformity with a standing radiological tibiofemoral angle ≥15°. Patients who had gross collateral ligament instability, any restriction of knee range of motion, genu recurvatum, predominant tibial deformity component, epiphyseal irregularities (e.g., multiple epiphyseal dysplasia, and septic sequelae), still active metabolic disease (e.g., rickets, osteomalacia, etc.) were excluded from the study. For radiological evaluation, both pre- and post-operatively, we used standing anteroposterior and lateral radiographs of both knees including whole thigh and leg. Radiological tibiofemoral angle was calculated by measuring the angle formed between the anatomical axis of tibia and femur (by drawing the longitudinal axis midway between tibial and femoral diaphyseal cortices). During follow-up, we used knee score as mentioned by Bostman et al. to assess the functional outcome [Table 1]. A score between 28 and 30 was considered as excellent. A score between 20 and 27 was classified as good and a score below 20 unsatisfactory.
The patients are operated under general or spinal anesthesia with tourniquet control [Figure 1]. Patient is placed supine on the operating table with knee flexed to 60° to ease access to the medial aspect of knee. Ankle and foot are also cleaned and painted and care is taken not to cover them with drapes so that alignment of lower limb could be easily determined intraoperatively.
|Figure 1: (a) Intra-operative photograph showing “V” marked over adductor tubercle. The longer anterior arm is placed at right angles to shorter posterior arm. The shorter posterior arm is advantageous as the posterior cortex is stronger than anterior cortex and better resists the backward rotatory pull of gastrocnemius, (b) the proximal “V” fragment (arrow) wedges into the distal metaphyseal bone providing inherent stability, (c) the bone graft obtained from nibbling of proximal “V” fragment is added to posterior and lateral parts of osteotomy after fixation with Kirschner wires|
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A medial longitudinal incision of about 6–8 cm (starting 2 cm from medial joint line of knee overlying adductor tubercle) is given over medial aspect of distal thigh. Deep fascia is exposed and incised. Vastus medialis is identified and elevated anteriorly from the edge. Periosteum overlying the distal medial femoral metaphysis is incised vertically and elevated subperiosteally to expose the metaphysis. After identifying the adductor tubercle, a “V” is marked with the apex over it. Both the limbs of “V” are at right angle to each other [Figure 1]a. The posterior limb is made shorter than anterior limb to counter the backward rotator forces imposed by the pull of the gastrocnemius. With an oscillating saw, an incomplete osteotomy sparing the lateral femoral cortex is made over the marked “V.” The uncut lateral cortex is then cut carefully using a hand-held osteotome to avoid disruption of the lateral periosteum and soft tissue injury. A small part of the bone from the medial cortex (anterior and posteriorly from proximal femoral fragment) is nibbled using a fine-tipped bone nibbler along the osteotomized border and preserved. This is important as it allows the narrower proximal femoral diaphyseal side to penetrate the relatively wider distal metaphysis after correction [Figure 1]b. Once the osteotomy is completed, deformity is corrected with a manual varus force with knee in full extension. Through medial penetration and crushing of cancellous bone, correction of the coronal plane deformity is achieved. The knee alignment achieved can be confirmed under image intensifier and changes made with gentle pressure over proximal thigh and leg region, if required. The osteotomy site is then fixed with two thick Kirschner wires from medial femoral condyle crossing the osteotomy site and engaging the lateral cortex of the proximal fragment. Bone graft (bone nibbled out from proximal edge) is packed over the posterior aspect of osteotomy site [Figure 1]c. Wound is closed in layers. A high groin above knee cast is applied with knee in full extension.
Patient is allowed to sit from the 2nd postoperative day and can initiate static knee strengthening exercises as soon as pain subsides. Partial weight bearing can be initiated at 3 weeks in the cast. After 6 weeks, both wires and plaster cast are removed and active knee joint range of motion exercise initiated. A radiograph is obtained at this time to look for union at osteotomy site and for evaluation of the achieved correction. Further evaluation of the knee range of motion and osteotomy healing is performed at 4 weeks intervals as the child progressively recovers full weight bearing.
| Results|| |
We operated 17 limbs in nine patients (females eight and male one) with a mean age of 11 years. All the genu valgum deformities were postrachitic but with healed status. One patient has unilateral deformity whereas eight had bilateral genu valgum deformity [Table 2]. The bilateral deformities were operated simultaneously. Mean follow-up of patients was 24.8 months (range; 20–32 months). Preoperative radiological tibio-femoral angle had a mean value of 20.2° (range; 15°–30°) which improved to a mean of 3.05° (range; 0°–5°) postoperatively [Figure 2]. Eight patients out of 9 (88.8%) had an excellent outcome with a knee score ≥28. One patient (11.1%) had good functional outcome and had a lesser knee score of 27. None of the patients had an unsatisfactory knee score. All patients recovered full range of knee motion within 6 weeks after removal of cast. The main complications noted were deep infection in one case and partial slippage of lower femoral physis in other. The partial slippage of epiphysis was probably due to the application of excessive force to achieve correction of deformity intraoperatively. Being a minimal slippage (<20%), it was managed conservatively. This male patient went on to achieve full range of motion of knee and excellent limb alignment in subsequent follow-ups [Figure 3]. The deep infection was controlled by debridement and intravenous antibiotics. No other complications such as failure of correction, nonunion of the osteotomy site, shortening, and knee stiffness were noted in any limb.
|Figure 2: (a) Clinical photograph showing bilateral genu valgum deformity at left knee (b) radiograph showing the bilateral genu deformity with tibiofemoral angle 30° and 20° right and left side, respectively (c) correction after “V” osteotomy (d) full range of motion was achieved as early as 9 weeks postoperatively (e) radiograph showing the corrected limb alignment with final tibiofemoral angle 5° both sides|
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|Figure 3: Complication-epiphyseal slip (a) left side genu valgum 20° (b) epiphyseal slip noted postoperatively (c) was managed conservatively in a cast. Radiographs showing healed status and tibiofemoral angle of 5° (d and e) patient achieved good clinical correction and range of motion at knee|
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| Discussion|| |
The prevalence of nutritional rickets is estimated to be as high as 10%–40% among children in several low-income Asian countries. With a high incidence of rickets, postrachitic deformities are a common presentation in outpatient department. The child is usually brought for treatment at the time when deformity rapidly worsens following pubertal growth. The management involves treatment of rickets and subsequent surgical correction of healed postrachitic deformities, if required.
Since the remaining physeal growth is limited (lower femoral epiphysis can fuse with diaphysis by age 14 or earlier in Asian females), growth modulation may not a reliable modality of treatment in these patients. In our personal experience, the postrachitic treatment physeal growth is somewhat unpredictable and has a tendency to fuse early. To correct a valgus deformity at knee in this age group, various techniques of distal femoral osteotomy has been described in the literature. A supracondylar linear femoral osteotomy involves crushing of the medial cortex. This technique requires prolong immobilization in spica cast with subsequent risk of knee stiffness. An intercondylar osteotomy with screw fixation was also described, but it was not widely accepted as this procedure is intra-articular and requires prolonged period of nonweight bearing. The most widely practiced method for correction of valgus deformity is supracondylar closing wedge osteotomy, with rigid internal fixation through blade plate or screw plate, but it has many disadvantages such as large exposure, implant and surgical cost, use of plate does not permit subsequent adjustment of alignment and need of a second surgery for implant removal. The dome osteotomy also has some limitations, use of special instruments, periosteal stripping, instability, requirement of implant, and the excessive translation required at the osteotomy site may limit the full correction of the deformity. Smaller series using monolateral and ring external fixators for correction are also described in literature. Main disadvantages with these fixator techniques are frequent pin site infections, difficulty in ambulation and daily activities and knee stiffness. High implant cost and need for frequent clinic visits are other limiting factors in low-income countries.
Supracondylar “V” osteotomy was first described by Aglietti et al. They used this procedure for correction of valgus deformity secondary to lateral compartment osteoarthritis of the knee (age group; 52–77 years) [Table 3]. Gupta et al. used this technique in adolescents and adults (age group; 15–23 years). They used buttress “L” plate to fix the osteotomy site and were able to achieve correction in all patients with 95.6% having an excellent functional outcome. Similarly, Agarwal in his case series (age group, 12–16 years) used staples for fixation and achieved correction in all cases. The study group included a much younger age group (10–12 years) and used minimal implants (external Kirschner wires). In our series, 88.8% of cases had an excellent outcome, 11.1% of patients had good functional outcome, whereas none of the patients had an unsatisfactory knee score [Table 3]. The distinct advantages of technique are: it is quick to perform with operating time <35 min, simultaneous deformity correction can be performed in both limbs if desired, no bleeding when done under a tourniquet, cancellous bone graft from proximal “V” fragment available for enhancement and early union at osteotomy site, minor changes in alignment possible since fixation with Kirschner wires is nonrigid, limited period of immobilization in above knee cast (6 weeks) and no second surgery under anesthesia for removal of implant. The apex of “V” embedded in the metaphyseal bone gives an additional inherent stability to the osteotomy. The osteotomy is an extra-articular procedure and requires smaller exposure. As knee joint is not opened, there were no incidences of stiffness, intraarticular infection and adhesion formation. Osteotomy site unites in approximately 6 weeks and it does not usually cause problem in range of motion of knee joint.
|Table 3: Aglietti's supracondylar “V” osteotomy: Comparison of various series|
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A peculiar complication we encountered was slippage of distal femoral epiphysis probably resulting from the use of excessive intraoperative force to crush distal metaphyseal cancellous bone with the “V” proximal fragment. We realized later from postoperative radiographs that our osteotomy was not extending to lateral cortex and thus incomplete in that particular case. The force exerted was thus transferred to physeal plate which yielded and slipped. Being a minor slip, this complication was managed conservatively with good outcome.
Based on age at operation and duration of follow up, all the nine children have not reached overall skeletal maturity on the last follow up. Effect of physeal plate growth disturbance may further progress after the last follow up in some children and therefore, follow up is required till skeletal maturity.
| Conclusion|| |
Aglietti's supracondylar “V” osteotomy is a relatively simple, low cost and viable deformity correction procedure. Simultaneous deformity correction in both limbs in single stage, minimum implants, and faster recovery of knee range of motion make it a useful procedure for use in health-care facilities in low-income countries. We advocate this technique for the correction of postrachitic genu valgum deformity in older children and adolescents with limited residual physeal growth not amenable to growth modulation procedures.
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Conflicts of interest
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3]