Efficacy and Safety of "Sleeper Plate" in Temporary Hemiepiphysiodesis and the Observation of "Tethering"

Does the Sleeper Plate Application for Temporary Epiphysiodesis Make Life Easier or Complicated? Increased Risk of Tethering

BACKGROUND

The present study aims to investigate the frequency of recurrence and tethering effect after only metaphyseal screw removal (sleeper plate technique) compared with the conventional complete plate removal in the treatment of lower extremity deformities with guided growth surgery.

METHODS

Seventy-two patients (107 limbs) treated by an 8-plate hemiepiphysiodesis technique around the knee joint were evaluated. After the desired correction, only metaphyseal screw was removed (sleeper plate group) in 35 limbs (25 patients), whereas both screws and plate were removed (plate removal group) in 72 limbs (47 patients). An increase of 5 degrees or more in joint orientation angles in the direction of the initial deformity was considered as recurrence. The rate of rebound, tethering, and maintenance of correction in groups was analyzed at the latest follow-up (mean of 49 mo).

RESULTS

The mean age of the patients was 97 months (range: 80 to 129 mo) at the time of index surgery. After a mean of 49 months (range: 16 to 86), 17 (48.5%) limbs maintained the desired stable correction in the sleeper plate group compared with 59 stable limbs (72.2%) in the plate removal group ( P <0.001). There was no statistically significant difference regarding recurrence between the sleeper plate group and the plate removal group (34.3% vs. 27.8%, respectively) ( P =0.216). Reinsertion of the metaphyseal screw was possible 8/12 limbs, and the remaining 4 limbs underwent further surgeries. There were 6 limbs (17.3%) of tethering in the sleeper plate group, and 4/6 limbs required further corrective surgeries. The remaining 2 limbs with slight tethering did not require further surgeries.

CONCLUSIONS

Removing only metaphyseal screw increases the risk of tethering. In addition, reinsertion of the screw may not be possible in all cases due to bony growth, and further corrective surgeries may be necessary. Close follow-up is required if the sleeper plate technique is to be applied.

LEVEL OF EVIDENCE

Level III.

The Perils of Sleeper Plates in Multiple Hereditary Exostosis: Tibial Deformity Overcorrection Due to Tether at Empty Metaphyseal Hole

BACKGROUND

Hemi-epiphysiodesis is the mainstay of treatment for angular deformities at the knee in children with multiple hereditary exostosis (MHE). Upon deformity correction, the metaphyseal screw may be removed from the hemi-epiphysiodesis plate, the sleeper plate technique, with anticipated reimplantation of the metaphyseal screw should the original deformity recur. The aim of the present study is to compare the incidence of complications with the sleeper plate technique with complete plate removal in an MHE cohort.

METHODS

Patients under the age of 18 with MHE who underwent hemi-epiphysiodesis of the proximal tibia and/or distal femur between February 1, 2016, and February 6, 2022 with a minimum 2-year follow-up or follow-up to skeletal maturity were identified via ICD-10 codes. Patient charts and radiographic images were reviewed to assess for the bone(s) treated, the use of sleeper plates, and whether any complication occurred, including overcorrection from bony ingrowth at the empty holes or deformity recurrence.

RESULTS

In 13 patients, 19 knees underwent hemi-epiphysiodesis at 30 sites; 13 distal femoral and 17 proximal tibial. Of 30 plates, 18 (60%) were removed completely upon deformity correction and 3 (10%) did not require removal due to skeletal maturity. Four of 13 (30.8%) femoral plates and 5 of 17 (29.4%) tibial plates were left as sleeper plates. All 5 tibial sleeper plates developed bony ingrowth into the empty metaphyseal screw hole, which led to unintended progressive deformity overcorrection. In the majority of cases, the deformity was addressed by the removal of the plate and exophytic bone and hemi-epiphysiodesis on the other side of the affected proximal tibia with subsequent resolution of the deformity.

CONCLUSIONS

All tibial sleeper plates developed bony ingrowth into the screwless metaphyseal hole. The bony ingrowth functioned as a tether, resulting in progressive deformity overcorrection. Sleeper plates should be avoided at the proximal tibia in patients with MHE, and extreme caution should be exercised when considering this technique at the distal femur or other sites.

LEVELS OF EVIDENCE

Level III-retrospective comparative study.

Growth modulation for angular knee deformities: a practical guideline

PURPOSE OF REVIEW

This study aimed to review the established concepts and advances related to growth modulation for treating knee angular deformities. Although they are considered well tolerated procedures, careful indications and accurate techniques are necessary to ensure good results.

RECENT FINDINGS

In addition to general clinical and radiographic evaluations, new tools such as two-dimensional low-dose radiography and gait analysis have been used to clarify angular and torsional combinations and the impact of mild angulations on the knee joint. Temporary epiphysiodesis is commonly the choice, and it can be performed with different implants such as staples, tension band plates (TBP), percutaneous transphyseal screws (PETS), sutures, and screws.

SUMMARY

Considering its principles, TBP has been preferred for younger children. Cost can be a limitation, and research for alternative implants such as screws and nonabsorbable sutures indicate they might be an alternative in the future. In adolescents, PETS becomes an attractive alternative; however, its reversible character has been controversial, and further studies are needed to establish limits in younger patients.