A case report

Correction of cubitus varus (gunstock) deformity in 12-year-old adolescent child with lateral closing wedge osteotomy & recon LCP fixation

Senthilrajan Angamuthu

Consultant Orthopaedic Surgeon, Kauvery Hospital, Salem, India

Background

Malunited supracondylar humerus fracture in children usually results in cubitus varus deformity. Cubitus varus deformity is less common in present time because of the availability image intensifier for fracture reduction and fixation. Cubitus varus deformity is nothing but outward angulation of elbow with supinated forearm. In addition to the varus deformity in coronal plane, there will be hyperextension on sagittal plane and the internal rotation on the horizontal plane. Due to the poor ability of distal humeral epiphysis to correct the deformity, it will persist into adulthood without any improvement. Though the cubitus varus deformity will not affect an elbow movement in most of the time, the unsightly appearance causes psychological stress to the child and parents, but also delay the daily life and learning of adolescents to a certain extent [1].

Various type of osteotomies is defined for standard non-progressive cubitus varus deformity. The optimal timing of corrective osteotomy is not well established in the literature. Early correction of deformity avoids the psychological stress of the long-standing unsightly appearance to the young child and parents. It also avoids the delayed bio-mechanical and functional disturbances to the affected elbow [3].

Modified French osteotomy is commonly used method for the correction of cubitus varus deformity. Fixation of the osteotomy with k-wires, figure of 8 wiring with cortical screws were found to be insufficient in holding the distal fragment in skeletally matured children above 8 years, which subsequently leads to lose of fixation and correction, the suboptimal fixation in children above 8 years delay the rehabilitation and early return of activity [2].

Case Presentation

Our patient a male 12 years of age, presented to the outpatient department with complaints of unsightly appearance of right elbow. According to the patient, he sustained injury to his right elbow one year back after he fell down at his home while playing. He was taken to orthopaedician where he was treated with closed reduction and posterior splinting, subsequent follow-up at 4th-week post-injury they noticed the minimal fracture displacement and he was advised to continue the same management for two more weeks and then started on physiotherapy to improve the range of movement. The patient and his parents noticed angulation of the right elbow subsequently without affecting the functional range of movement (Figs. 1 and 2) On examination right side bow elbow with near normal range of movement. Pre-operative assessment done with antero-posterior and lateral radiograph with elbow in full extension and forearm in supination. The humerus-elbow-wrist angle was measured on both sides (Figs. 3 and 4).

Fig 1.

Fig 2.

Fig. 4. Pre-operative evaluation of varus angle.

He was planned for Lateral based closing wedge osteotomy to correct the cubitus varus deformity. Preoperative work-up, he had 20^o of varus deformity, opposite normal limb valgus angle was 9^o (Figs. 3-6).

Fig. 3.

Fig. 4.

Fig. 5.

Fig. 6.

Patient in supine position through lateral approach right distal humerus was exposed, Desired wedge of bone was marked with K-wire and checked under C-arm. Desired 26 mm wedge of bone taken without breaching the medial cortex and periosteum (Figs. 7-10).

Fig. 7.

Fig. 8.

Fig. 9.

Fig. 10.

Fig. 11.

Figs. 9 and 10. Osteotomy site – Medial cortex and perioateal sleeve were carefully preserved.

Both sagittal and coronal plane deformity was corrected by closing the osteotomy site by breaking the medial cortex and external rotation of the distal fragment without breaching the medial periosteal sleeve. The osteotomy site was fixed with 4,-hole LCP.

Fig. 12.

Fig. 13.

Fig. 14.

Figs. 11-13. Osteotomy closed and fixed with 4 Hole recon LCP.

Postoperative elbow was supported with a posterior splint for 3 weeks, and he was on Indomethacin 75 mg OD.

Fig. 15.

Fig. 16.

Fig. 17.

Fig. 18.

Figs. 14-17. Functional outcome at the end of 6 week.

Postoperative rehabilitation was started after 3 weeks, he was gained his full range of motion at the end of 6 weeks from surgery (Figs. 14-17).

Discussion

Lateral close wedge (LCW) osteotomy is the easiest and safest, and inherently stable method of correction. The type of fixation of osteotomy is conducive to achieving a good result. Unstable, non-rigid fixation leads to slip of the fragments and loss of correction. Various methods of fixation are: use of two screws and figure of eight tension band wire attached to them, plate fixation, cross K-wire fixation, staples; few surgeons use no fixation. The fixation by crossed K-wires frequently leads to loosening of the fixation with recurrence of deformity, pin tract infection, skin slough, nerve palsy, and rarely brachial artery aneurysm.

This modification reported by us to stabilize lateral closed wedge osteotomy for the cubitus varus deformity has certain advantages. We have used a 4-hole Low profile locking plate with screws at the osteotomy site which gives us more control on the proximal and distal fragments which avoids the fracture of the medial cortex after closing the osteotomy. In addition, per-operative clinical evaluation gives better control of translation, rotation, and angulations. Thus, this method of fixation reduces the chance of the recurrence of the deformity. We respected the periosteum by not stripping it too much, thus giving the osteotomy a more biological environment for fast healing. Experience has shown that the biological determinants of fracture healing are as important as the mechanical and must be respected.

Conclusion

We believe that the early correction of cubitus varus deformity in an adolescent child and early return to his/her routine activity avoid unnecessary stress to the child and to his/her parents. The method of fixation should be simple reliable, acceptable, and strong enough to withstand early rehabilitation. We believe that the recon locking plate fixation of a modified French osteotomy in older children (above 8 years) provided stable fixation.

References

Solfelt DA, Hill BW, Anderson CP, et al. Supracondylar osteotomy for the treatment of cubitus varus in children: a systematic review. Bone Joint J. 2014;96-B(5):691-700.
Kasirajan S, Govindasamy R, Krishna Lokayah S. Functional outcome of modified French osteotomy fixed with recon-locking compression plate in older children. Clin Orthop Trauma. 2021;16:202-7.
Azzam W, Catagni MA, Ayoub MA, et al. Early correction of malunited supracondylar humerus fractures in young children. Injury. 2020;51(11):2574-80.

Dr. A. Senthilrajan

Consultant Orthopaedic Surgeon