Pediatric fractures following implant removal: A systematic review

The fate of hemiepiphysiodesis implants left in place after skeletal maturity in patients with idiopathic genu valgum

Hemiepiphysiodesis using tension band plate and screws is a frequently used technique for the correction of lower extremity angular deformities. These implants are often left in place if patients have corrected their alignment on reaching skeletal maturity. There is little information regarding the rate of and reasons for subsequent removal of these deep implants. This retrospective case-control study included patients treated with hemiepiphysiodesis with tension band plate and screws at the distal femur and/or proximal tibia for idiopathic genu valgum and reached skeletal maturity with implants retained. Electronic medical records and radiographs were reviewed for patient characteristics and the need for subsequent removal of implants. Those who had implants removed were compared to those with implants not removed using Student's t-test for continuous variables and chi-square for categorical variables. Forty-six patients met inclusion criteria. Twenty-five of 46 patients (54%) underwent subsequent removal of deep implants, and all cases were due to symptoms related to the plate and screws. Factors associated with removal of deep implants included multiple vs. single rounds of hemiepiphysiodesis (76% vs. 43%, P = 0.02) and plates at the distal medial femur alone (P = 0.004). There were no differences between groups regarding sex, age at hemiepiphysiodesis, height, weight, and BMI. In conclusion, after skeletal maturity, there was a 54% rate of removal of symptomatic hemiepiphysiodesis implants. Factors associated with implant removal include repeat hemiepiphysiodesis and isolated distal medial femur plate position. This information can be used to guide patient and provider expectations as patients transition to adulthood.

Metal implants in children

Background

Metal implants are increasingly used in children for trauma and deformity correction. This review outlines the current knowledge on the types of metals used and explores reasons for removal and the potential for long-term health issues of metal implants.

Methods

The literature pertaining to these aspects was studied and summarised in this review.

Results

Types of metals used have evolved as well as the development of children-specific implants. Improvements in deformity correction are measurable with likely improved outcomes and reduced health costs. Indications for metal implant removal following successful treatment remain ill-defined; however, the risks of removal are known with a minimum 6% complication rate. Health costs could be reduced by around 6% by judicious decisions to leave metal in place. Implant removal should only be encouraged in the presence of infection, mechanical failure or symptoms that are truly attributable to the implant. In the domain of spinal implants, there is evidence of significant metal ion release, most notably titanium which remains elevated to many times baseline levels beyond 2 years. The detection of titanium at low levels requires special techniques. The long-term health effects on patients and/or their offspring are not well defined, although well described in animal models.

Conclusion

The risks of metal removal are significant. Clinicians need to be aware of potential health risks in the use of metal implants and the potential for covert toxicity effects in children especially with their long life ahead. There is a need for greater awareness of metal alloy composition and implant design to minimise risks.

Level of evidence

Level V.

No Value Found With Routine Early Postoperative Radiographs after Implant Removal in Pediatric Patients

BACKGROUND

Implants are routinely removed in pediatric patients. Fracture through the prior implant site is a common worry after implant removal. Early post-implant removal radiographs are routinely used to evaluate the prior implant removal sites and to assess when a patient may return to normal activities. To our knowledge, the value of early, routine postoperative radiographs after elective implant removal in pediatric patients has not been studied.

METHODS

A retrospective patient cohort of pediatric patients who had implant removal from an extremity from 2017 to 2019 was used in this study. Data were collected for patient demographics, implant site, reason for primary surgery, complications, number of postoperative radiographs, radiation exposure, cost of imaging, and whether the postoperative plan was changed by imaging.

RESULTS

Two hundred ninety patients were included in the study. Postoperative plans were changed only in 0.69% of patients (n = 2) because of abnormal 2-week radiographs and 1.72% (n = 5) because of abnormal 6-week radiographs. However, the event's proportion difference (change of management) was not statically significant ( P = 0.182) between those who had a radiograph obtained and those who did not. The mean follow-up time was 16 months. The mean number of postoperative radiographs obtained was 3.74, the mean cost per radiograph was $103, and the mean postoperative radiation exposure was 1.34 mSv. No fractures were observed after implant removal.

DISCUSSION

A retrospective review of the value of early, postoperative radiographs after routine orthopaedic implant removal found that postoperative radiographs at 2 and 6 weeks did not change the postoperative plan for most of the patients. Postoperative radiographs have an average cost of $103, and radiation exposure equal to approximately 6 months of natural background radiation.

LEVEL OF EVIDENCE

Level III.

Comparison of three fixation methods in paediatric metaphyseal-diaphysis junction fracture of the distal radius: a retrospective study in two centres

Background

The distal radial metaphyseal-diaphysis junction fractures (DRMDJ) have various treatment methods and are easily lead to complications. This study aims to compare the anterograde elastic stable intramedullary nailing (ESIN-A), retrograde K-wire fixation (KW-R), and retrograde precision-shaping elastic intramedullary nailing (ESIN-RPS) for the treatment of pediatric DRMDJ fractures.

Materials and methods

A total of 113 patients with DRMDJ fractures (36 in the ESIN-A group, 52 in the KW-R group, and 25 in the ESIN-RPS group) from two centres were retrospectively analysed. Perioperative operation time, intraoperative bleeding, fluoroscopy times, alignment rate and angulation on radiography were compared among the three groups. Forearm rotation, healing, wrist function, and complications were compared at the last follow-up.

Results

The mean operation times of the three groups were as follows: KW-R (72 ± 13 min) > ESIN-A (65 ± 18 min) > ESIN-RPS (52 ± 11 min), with a significant difference (P < 0.01). The incision length and intraoperative blood loss of ESIN-A (1.8 ± 0.2 cm; 8.3 ± 3.7 ml) were significantly higher than ESIN-RPS (1.4 ± 0.8 cm; 5.5 ± 2.7 ml) (P < 0.05), respectively. The postoperative alignment rate on the anteroposterior (AP) and the lateral plane of ESIN-RPS (93.1 ± 4.4%; 95.01 ± 2.8%) was significantly greater than that of KW-R (82.1 ± 6.8%; 88.5 ± 4.5%) and ESIN-A (79.2 ± 5.2%; 83.2 ± 2.5%) (P < 0.01). The residual angulation of ESIN-RPS (3.3 ± 1.2°; 2.9 ± 0.8°) was significantly greater than that for ESIN-A (5.1 ± 1.7°; 4.9 ± 2.1°) and KW-R (6.6 ± 2.8°; 7.5 ± 1.6°) (P < 0.05). The excellent and good ratio of ESIN-RPS (95.8%) was significantly higher than that of ESIN-A (86.5%) and KW-R (86.1%) according to the Gartland-Werley standard. There was a significant difference in delayed union between the KW-R and ESIN-A (P < 0.05). Additionally, there were two cases of radial nerve injury in the ESIN-A group, one case of tendon rupture in the ESIN-RPS group, and one case of tendon rupture in the KW-R group. The ESIN-RPS group had significantly fewer complications than the KW-R group (P < 0.05). The ESIN-A group also had significantly fewer complications than the KW-R group (P < 0.05).

Conclusion

Compared with ESIN-A and KW-R, ESIN-RPS has the advantages of a shorter operation time, less intraoperative blood loss, less radiation, better alignment, and fewer complications. The ESIN-RPS was suggested as an optimal choice for paediatric DRMDJ fractures.