Plate-assisted Lengthening of the Femur and Tibia in Pediatric Patients

The need for state-of-the-art orthopedic surgical technology in low- to middle income countries : The case of distraction epiphyseolysis for limb lengthening in children with fibular hemimelia in Uzbekistan

INTRODUCTION

Amongst low- to middle income countries (LMIC), outdated and poorly documented orthopedic interventions may pose patients at risk for complications, serious adverse events (SAE) and unsatisfactory results, contradicting the World Health Organization's (WHO) Safe Surgery mandates. Use cases of conditions managed inadequately in LMIC environments are necessary to increase awareness of stakeholders and overcome deficiencies in collaboration with high-income countries (HIC).

MATERIALS AND METHODS

Methodological and clinical experts from the BG Kliniken and the Charité, Berlin, Germany, were invited to investigate established processes for musculoskeletal disorders and injuries in Tashkent, Uzbekistan. Congenital lower leg discrepancy due to fibular hemimelia was recognized as an illustrative example to prove the effectiveness of local treatment guidelines, still relying on distraction epiphyseolysis (chondrodiatasis) via an Ilizarov frame. Routine data from hospital records, images and outpatient follow-up examinations were compared to estimates from a review of studies of limb-lengthening by other techniques.

RESULTS

Data from 16 of 49 immature patients (10 males, 6 females, mean age at surgery, 4.2 ± 2.3 years) undergoing chondrodiatasis between 2017 and 2021 showed a mean limb elongation of 2.4 (95% confidence interval [CI], 1.9 to 2.9) cm after a median follow-up of 29 (range, 24 to 36) months. While no complications or SAE were noted, findings are compatible with a risk of 21% under an upper 97.5% confidence limit for null events. No reproducible classification of hemimelia, surgical or general complications, assessment of functional outcomes or health-related quality of life were available. The pooled average length gain from 21 studies on different other interventions with osteotomy enrolling 458 limbs was 5.1 (95% CI, 5.0 to 5.3) cm.

CONCLUSIONS OF THE USE CASE

Limb lengthening for hereditary fibular hemimelia in Uzbekistan revealed rather obsolete surgical algorithms, inadequate documentation, and unreliable outcome assessment. Resource limitations notwithstanding, knowledge transfer, implementation of current procedures and hardware, and international collaboration is vital to improve quality of care in this scenario and for the benefit of LMIC in general.

The results of femoral lengthening using domestic unilateral external fixation and then plating: the first case series in Vietnam

Introduction and importance

This study aimed to assess the results of femoral lengthening using an external fixator and then plating.

Case presentation

This prospective case series study enrolled 11 patients who underwent femoral lengthening and then plating (LATP) between January 2019 and April 2023. The average age of patients was 14.45 ± 7.54 years. One patient with a femur was lengthened and plated, and one tibia was lengthened over a nail simultaneously. The average femoral lengthening was 8.41 ± 1.35 cm.

Clinical discussion

The femoral healing result was excellent in seven femurs and good in four femurs; the functional outcome was excellent in five patients and good in six patients. Pin-track infection occurred in all patients. A limited range of motion of knee flexion occurred in eight patients. Femoral varus and procurvatum deviation occurred during distraction in four and two patients. Femoral LATP was considered an attractive alternative to intramedullary lengthening nails in a low-income country.

Conclusion

Our research suggests that femoral LATP was an effective method. However, the most common complications were pin-site infection and extensive knee contracture. Further research should be done with a larger sample size and longer follow-up time.

Level of evidence

Level IV-prospective observational case series study.

Antegrade femoral lengthening and simultaneous hemiepiphysiodesis for congenital femoral deficiency

Purpose

Congenital femoral deficiency is characterized by limb length discrepancy and genu valgum. Lengthening of the femur along its anatomic axis increases valgus alignment by medial knee translation. Pairing limb lengthening with simultaneous medial distal femoral hemiepiphysiodesis can simultaneously correct two limb deformities.

Methods

All skeletally immature patients with congenital femoral deficiency who underwent antegrade femoral lengthening and concomitant guided growth over a 4-year period were reviewed. Length and alignment data were quantified during lengthening, consolidation, and for 1 year after guided growth implants were removed or the patient reached skeletal maturity. Digital simulation was performed for all lengthenings to assess the mechanical alignment that would have been achieved had lengthening been performed without medial distal femoral hemiepiphysiodesis.

Results

Nine patients (five males, four females, mean age = 12.3 ± 1.9 years) underwent 10 antegrade intramedullary femoral lengthenings with simultaneous medial distal femoral hemiepiphysiodesis. All had improvement in valgus alignment (average improvement in mechanical axis deviation was 18 ± 11 mm, average change in limb alignment was 6 ± 5°). In simulated lengthenings without guided growth, all limbs would have experienced increased lateral mechanical axis deviation of 5 ± 3 mm. The hemiepiphysiodesis implant and lengthening device were explanted simultaneously in 7 of 10 lengthenings.

Conclusion

Simultaneous medial distal femoral hemiepiphysiodesis with antegrade femoral lengthening for ongenital femoral deficiency can minimize the number of surgical episodes for the skeletally immature patient. The lengthening device and guided growth construct can be removed simultaneously in a majority of cases, saving children one or two additional surgical treatments.

Motorized Plate Lengthening of the Femur in Children: A Preliminary Report

BACKGROUND

Limb lengthening by distraction osteogenesis can be performed with motorized internal devices, but intramedullary implants risk avascular necrosis of the femoral head in young children. A method of internal limb lengthening using a motorized expandable plate has been developed and preliminary results are presented.

METHODS

Seven skeletally immature patients (ages 2.7 to 9.7 y) with congenital femoral deficiencies underwent femoral lengthening with the use of a magnetic expandable plate. Surgical details, lengthening parameters, Limb Lengthening and Reconstruction Society-Angular deformity, Infection, Motion index, and complications were reviewed and classified according to the modified Clavien-Dindo system.

RESULTS

An average lengthening was 4.1 cm (range, 3.3 to 4.4 cm) comprising 18% of initial femoral segment length (range, 14% to 21%). The average lengthening phase was 50.2 days (range, 40 to 57 d) and weight-bearing was initiated at an average of 13 weeks from surgery (range, 8 to 18 wk). Limb deformities and length discrepancies were of moderate complexity, with an Limb Lengthening and Reconstruction Society-Angular deformity, Infection, Motion score of 6.57 (range, 6 to 7). Complication rates were comparable to previously reported methods of femoral lengthening. One patient underwent reoperation for patellar instability and 1 patient experienced radiographic hip subluxation which was observed. Small magnitude varus was observed in regenerate in 3 of 7 cases, none requiring treatment. Preoperative planning consisted of careful localization of the corticotomy site, acute deformity correction at the lengthening site in 3 cases, and implant orientation.

CONCLUSIONS

Limb lengthening with motorized internal plates is feasible for young children with congenital femoral deficiency for whom intramedullary lengthening is unsafe or if external fixation is to be avoided. However, the fundamental principles of distraction osteogenesis and risks of lengthening for congenital discrepancies remain unchanged. Specific considerations herein include: careful planning of implant length and positioning, adjacent joint protection with adjunctive means, and mitigating deformity of the regenerate during distraction.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Tibial Lengthening along Submuscular Plate with Simultaneous Acute Tibial Deformity Correction by High-Energy Osteotomy: A Comparative Study

Submuscular plating and osteotomy using power saw have shown the benefits in certain situations of limb lengthening. However, no previous studies combining both procedures have been conducted for acute tibial deformity correction and limb lengthening. Nineteen cases were enrolled in this study. Ten patients received tibial lengthening with acute knee angular deformity correction using high-energy osteotomy (Group 1), and nine patients received tibial lengthening only with osteotomy using multiple drills and osteotome (Group 2). Radiographic parameters retrieved before and after the operation included leg-length discrepancy, tibial length, length gained, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), and mechanical axis deviation (MAD). There were significant differences between groups in terms of external fixator index (EFI) (p = 0.013) and healing index (HI) (p = 0.014), but no significance in the length gained (p = 0.356). The latest postoperative mLDFA (p = 0.315), MPTA (p = 0.497), and MAD (p = 0.211) of Group 1 were not distinguishable from Group 2. The functional outcomes were excellent, and there were no permanent complications. Despite showing a longer healing time, this alternative lengthening procedure which combines fixator-assisted plate lengthening in the tibia with simultaneous surgical intervention of acute tibial deformity correction using an oscillating saw is appropriate for patients with leg-length discrepancy and angular deformity of the tibia.

Extramedullary Motorized Lengthening of the Femur in Young Children

BACKGROUND

Limb lengthening by distraction osteogenesis is now achievable via motorized intramedullary devices, mitigating many complications of lengthening by external fixation. In young patients, antegrade intramedullary nailing of the femur risks avascular necrosis of the femoral head. A method of extramedullary placement of a motorized expandable intramedullary nail has been employed by the senior author to safely achieve femoral lengthening without the use of an external fixator in young patients.

METHODS

Eleven skeletally immature patients with lower limb length discrepancy were reviewed who underwent extramedullary placement of a magnetic, expandable intramedullary nail for lengthening of the femur. Surgical details, lengthening parameters, and complications were reviewed and classified according to the modified Clavien-Dindo Classification.

RESULTS

Average lengthening was 32.3 mm (range: 27 to 40 mm) comprising an average 14.8% of femoral segment length. The average lengthening duration was 6.3 weeks, and average full weight-bearing began at 12.6 weeks. All but 1 patient underwent early removal of the device at an average of 4.5 months, and 5 had immediate plating of the femur. Complications rates were comparable to other methods of femoral lengthening, including varus or procurvatum through the regenerate, and unplanned reoperation in 3 of 11 cases. Preoperative considerations included careful planning of implant length due to short femoral segments and protection of the knee joint from contracture or iatrogenic instability.

CONCLUSIONS

Extramedullary placement of a magnetic expandable intramedullary lengthening nail can achieve lengthening of the femur without the use of external fixation. Considerations with this technique include careful planning of implant length relative to trochanteric-physeal distance, protection against knee subluxation during lengthening, and mitigating deformity of the regenerate. Off-label, extramedullary use of these devices can be considered to decrease the burdens of external fixation in young children. The technique begs the advent of future all-internal technology specifically designed for safe limb lengthening in this age group.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

What's New in Pediatric Limb Lengthening and Deformity Correction?

Over the past 5 years, published literature regarding treatment of pediatric limb deformity and limb length discrepancy demonstrates much interest in better understanding, categorizing and treating these challenging problems. Many studies explore expanding and refining indications for traditional treatment methods like guided growth techniques. Other studies have evaluated the results of new techniques such as lengthening via mechanized intramedullary nails. Additionally, series comparing older and newer techniques such as lengthening with external devices versus mechanized nails are becoming increasingly available.

Lengthening of the Humerus Using a Motorized Lengthening Nail: A Retrospective Comparative Series

BACKGROUND

Lengthening of the humerus has traditionally been accomplished by the use of external fixation. Intramedullary motorized lengthening nails are now frequently used for lower limb lengthening, and this technology is slowly being adopted for use in the humerus.

METHODS

A retrospective, single-surgeon experience of pediatric humeral lengthenings was performed. The time period surveyed included use of external fixation (EF) for lengthening, and the use of a motorized nail (MN) for lengthening. The primary outcome measures were lengthening magnitude achieved, duration of lengthening, frequency and type of complications encountered, or further procedures required, during each lengthening.

RESULTS

From 1999 to 2018, 13 humeral lengthenings were performed in 9 patients. Six lengthenings were performed using the MN technique and 7 using the EF technique. The average absolute lengthening achieved was 8.5±1.3 cm in the EF group and 6.6±2.3 cm in the MN group. The duration of lengthening averaged 114 days in the MN group and 103 days in the EF group. The average duration of EF time was 215 days. Two patients underwent an initial EF lengthening of a humerus and then underwent a second lengthening using the MN technique. Two of 6 (33%) MN lengthenings and 3 of 7 (43%) EF lengthenings experienced complications during treatment. Two patients in the MN group underwent planned reversal and redeployment of their motorized nails to attain the planned lengthening magnitude.

CONCLUSIONS

Humeral lengthening using motorized intramedullary nails is a safe technique that mitigates some of the complications of EF including pin site infection. It is well tolerated by patients. For lengthenings of a large magnitude, reversal and reuse of MN can be considered.

The role of external fixation in paediatric limb lengthening and deformity correction

Limb deformity and shortening remains a common presenting complaint in paediatric orthopaedics. The ability to restore length, alignment with consistent bone formation allows standardised treatment in these difficult conditions. The use of an external fixator produces a stable construct which allows manipulation of the bone segments, with a controlled rate and rhythm. Deformity analysis permits the surgeon to plan osteotomy levels and frame application to produce accurate correction. Complications, especially in congenital conditions remain an issue and modification of the treatment is required to try and reduce their incidence. New types of fixators, the latest being hexapod frames, have increased the versatility in deformity correction. The aim of this paper is to review the use of external fixators in elective paediatric orthopaedics and highlight the latest changes in technique and application for the limb reconstruction surgeon.

Posteromedial bowing of the tibia: a benign condition or a case for limb reconstruction?

PURPOSE

To review the initial deformity and subsequent remodelling in posteromedial bowing of the tibia and the outcome of limb reconstruction in this condition.

PATIENTS AND METHODS

In all, 38 patients with posteromedial bowing of the tibia presenting between 2000 and 2016 were identified. Mean follow-up from presentation was 78 months. A total of 17 patients underwent lengthening and deformity correction surgery, whilst three further patients are awaiting lengthening and deformity correction procedures.

RESULTS

The greatest correction of deformity occurred in the first year of life, but after the age of four years, remodelling was limited. The absolute leg-length discrepancy (LLD) increased throughout growth with a mean 14.3% discrepancy in tibial length. In the lengthening group, mean length gained per episode was 45 mm (35 to 60). Mean duration in frame was 192 days, with a mean healing index of 42.4 days/cm. Significantly higher rates of recurrence in LLD were seen in those undergoing lengthening under the age of ten years (p = 0.046). Four contralateral epiphysiodeses were also performed.

CONCLUSION

Posteromedial bowing of the tibia improves spontaneously during the first years of life, but in 20/38 (53%) patients, limb reconstruction was indicated for significant residual deformity and/or worsening LLD. For larger discrepancies and persistent deformity, limb reconstruction with a hexapod external fixator should be considered as part of the treatment options.

LEVEL OF EVIDENCE

Level IV (Case series).

Distal femoral flexion deformity from growth disturbance treated with a two-level osteotomy and internal lengthening nail

Salter Harris fractures of the distal femur can lead to growth disturbance with resulting leg length inequality and knee deformity. We have looked at a case series (3) of patients who presented with a distal femur flexion malunion and shortening treated with a distal femoral osteotomy and plating and a proximal femoral osteotomy with a magnetic internal lengthening nail. Does a two-level osteotomy and internal fixation approach provide a reliable result both radiographically and functionally? The average knee extension loss was 12°, LLD 47 mm, PDFA 65°, MAD 2 mm. The patients were treated with an acute, posterior, opening wedge osteotomy of the distal femur stabilized with a lateral plate and screws and grafted with cancellous chips and putty. A second osteotomy was made proximally in the femur percutaneously, and the internal lengthening nail was inserted. Lengthening was done at approximately 1 mm/day. The average extension gain was 12°; amount of lengthening at the proximal site was 40 mm, LLD was 3 mm. The average PDFA was 81°, and MAD 3 mm. There were no complications. Functional results were excellent. Bone healing index was 24 days/cm. The average distance from the distal osteotomy to the joint line was 57 mm. The technique of two-level femur osteotomy stabilized with a plate and lengthening nail yielded excellent results with acceptable correction of deformity, full knee extension, and improved function. There were no complications including implant failure, infection, need for blood transfusion, knee stiffness, nonunion, compartment syndrome, or malunion.

Lower extremity growth and deformity

The pediatric lower extremity has well known growth patterns. When deformities or growth disturbances occur, there are several methods to measure and predict the resulting discrepancy, including the Green-Anderson, Moseley, and Multiplier methods. Many techniques exist to correct leg length discrepancy and deformity such and temporary epiphysiodesis, permanent epiphysiodesis, external fixators, and internal lengthening devices. All of these methods have numerous complications and limitations; however, with careful planning and patient selection, length and alignment can be improved with high patient satisfaction.