Cozen's deformity: resolved by guided growth

The Fate of Overcorrection After Hemiepiphysiodesis in Valgus Deformities Around the Knee

BACKGROUND

Tension band plating is widely used in the surgical treatment of coronal plane deformities around the knee. The rebound phenomenon after implant removal is a common complication of this technique. Overcorrection of joint orientation angles is a method to minimize the effect of the rebound phenomenon. This study aims to investigate the natural course of overcorrected joint orientation angles after plate removal in patients with genu valgum deformity.

METHODS

Patients who underwent hemiepiphysiodesis with tension band plating due to genu valgum deformity between 2010 and 2019 were retrospectively analyzed. Mechanical lateral distal femoral angles (mLDFA) and mechanical medial proximal tibial angles were calculated before plate application, before implant removal, and at the last follow-up. At the implant removal, mLDFA>90 degrees and mechanical medial proximal tibial angles <85 degrees were accepted as overcorrected.

RESULTS

Seventy-two segments from 45 patients were included. For femoral valgus deformities (n=59), the mean mLDFAs at index surgery, implant removal, and the last follow-up were 79.8±3.9 degrees, 95.5±3.7 degrees, and 87.3±5.1 degrees, respectively. In the more and less than 10 degrees rebound groups, the median age of patients at index surgery were 66 and 101 months (P=0.04), the mLDFA during implant removal were 97.8 degrees and 94.4 degrees (P=0.005), and the mean amount of correction in mLDFA was 17 degrees and 13 degrees (P=0.001), respectively. At the last follow-up, joint orientation angles were found to be still overcorrected in 16 (22%), within normal limits in 36 (50%), and undercorrected in 20 (28%) segments. Ten (13%) segments required additional surgery due to residual deformity.

CONCLUSIONS

Overcorrection with tension band plating is an effective modality in the treatment of genu valgum deformity. Rebound after plate removal increases as the age at index surgery decreases and the amount of conscious overcorrection increases. Most segments return to normal joint orientation angle limits after overcorrection. We recommend a mean of 5 degrees routine overcorrection in patients with genu valgum deformity to overcome the rebound phenomenon and to make future interventions easier if ever needed.

LEVEL OF EVIDENCE

Level III.

Coronal plane deformity around the knee in the skeletally immature population: A review of principles of evaluation and treatment

Coronal plane deformity around the knee, also known as genu varum or genu valgum, is a common finding in clinical practice for pediatricians and orthopedists. These deformities can be physiological or pathological. If untreated, pathological deformities can lead to abnormal joint loading and a consequent risk of premature osteoarthritis. The aim of this review is to provide a framework for the diagnosis and management of genu varum and genu valgum in skeletally immature patients.

[Epiphysiodesis and hemiepiphysiodesis : Physeal arrest and guided growth for the lower extremity]

The principals of growth arrest by epiphysiodesis and growth guidance by hemiepiphysiodesis are effective and powerful surgical techniques in pediatric orthopedics. These procedures can be used to correct leg length discrepancies as well as sagittal, coronal and oblique deformities. A differentiation is made between temporary and permanent techniques. The most significant advantage is that these techniques are minimally invasive and have low complication rates compared to acute osteotomy and gradual deformity correction. For optimal outcome an exact preoperative planning is needed to ensure accurate timing of the procedure, especially when permanent epiphysiodesis techniques are used. Although epiphysiodesis and hemiepiphysiodesis around the pediatric knee are most frequently used and can be considered the gold standard treatment of coronal plane deformities and leg length discrepancies, novel techniques for the hip and ankle are increasingly being performed. The successful clinical results with low complications support the broad use of hemiepiphysiodesis and epiphysiodesis for a variety of indications in the growing skeleton with deformities and leg length differences.

Guided Growth for Tibial Recurvatum

Aim and objective

Sagittal guided growth of the distal anterior femur has been shown to be effective for the correction of fixed knee flexion deformity that is encountered in clinical practice. The opposite deformity, namely genu recurvatum, is comparatively uncommon in children. The most common aetiology is post-traumatic. Acute correction by means of osteotomy has significant associated risks. Our objective was to determine whether a posterior 8-plate would suffice in correcting tibial recurvatum and obviate the need for an osteotomy.

Materials and methods

We included a total of five deformities, three boys (one bilateral) and one girl, managed by means of tethering of the posterior proximal tibial physis with a tension band plate. Standard radiographs obtained preoperatively and at follow-up included a standing anteroposterior (AP) of the legs noting limb lengths and the mechanical axis. We also obtained standing lateral views of each knee in maximal extension to measure and compare the posterior proximal tibial angle (PPTA).

Results

The same-day surgery was well tolerated and there were no surgical or post-operative complications. The preoperative PPTA ranged from 106° to 117° and averaged 84° at follow-up. Correction occurred in an average of 20 months (range of 18–24 months). The patient with bilateral recurvatum due to Hurler's syndrome developed unilateral recurrent recurvatum culminating in percutaneous reinsertion of the metaphyseal screw. For each patient, knee hyperextension and associated pseudo-laxity resolved and limb lengths remained equal at follow-up.

Conclusion

Children with progressive genu recurvatum typically present with an insidious onset of symptoms. Guided growth of the posterior proximal tibia is a safe and effective means of correcting the deformity; osteotomy was avoided in this series.

Level of evidence

III – retrospective case series – no controls.

How to cite this article

Stevens P, Stephens A, Rothberg D. Guided Growth for Tibial Recurvatum. Strategies Trauma Limb Reconstr 2021;16(3):172–175.

Rapidly acquired valgus deformity of the knee after osteochondroma resection in multiple hereditary exostoses pediatric patients: A report of two cases

Patients with multiple hereditary exostoses (MHE) often develop leg length discrepancies and limb alignment deformity around the knee as part of the natural course of the disease. Limb alignment deformity occurring post-resection of an osteochondroma has been described in one case report and only pertaining to the proximal medial tibia location. Here we describe the case of 2 patients with MHE, a 7-year-old female who underwent resection of distal femur and proximal tibia osteochondromas and a 9-year-old female who had a distal femur osteochondroma resected. Both patients developed rapidly progressive valgus knee deformity requiring surgical intervention. Excision of osteochondromas near the physis of a skeletally immature patient can cause overgrowth from the involved side of the growth plate resulting in a rapidly progressing unilateral coronal plane deformity. Surgeons should be aware of this potential complication and closely follow growing patients with serial alignment radiographs and counsel the family regarding the potential of acquired limb deformity and subsequent surgeries.

Cozen's Phenomenon After Repair of a Medial Collateral Ligament Periosteal Avulsion in a Pediatric Athlete: A Case Report

CASE

A 13-year-old boy sustained an acute, grade III medial collateral ligament (MCL) distal periosteal avulsion injury while playing noncontact football. Treatment consisted of diagnostic knee arthroscopy with open physeal-sparing MCL repair. At approximately 1-year follow-up, new development of genu valgum in the operative extremity was noted. After 8 months of nonoperative treatment with deformity progression, the patient underwent correction with proximal medial tibial hemiepiphysiodesis.

CONCLUSION

Although Cozen's phenomenon commonly occurs after a proximal metaphyseal tibial fracture in children aged 2 to 7 years, it can occur as a rare complication of MCL injury/repair and remains a possible outcome in skeletally immature patients.

Growth modulation with tension-band plates for the correction of paediatric lower limb angular deformity: current concepts and indications for a rational use

Growth modulation (GM) with tension-band plates (TBPs) by tethering part of the growth plate is an established technique for the correction of angular deformities in children, and it has increasingly supplanted more invasive osteotomies.Growth modulation with TBPs is a safe and effective method to correct a variety of deformities in skeletally immature patients with idiopathic and pathological physes. The most common indication is a persistent deformity in the coronal plane of the knee exceeding 10°, with anterior and/or lateral joint pain, patellofemoral instability, gait disturbance, or cosmetic concerns. GM has also shown good results in patients with fixed flexion deformity of the knee and ankle valgus.This paper reviews the history of the procedure, current indications, and recent advances underlying physeal manipulation with TBPs. Cite this article: EFORT Open Rev 2021;6:658-668. DOI: 10.1302/2058-5241.6.200098.

Does Cozen's phenomenon warrant surgical intervention?

PURPOSE

Proximal tibial metaphyseal fractures can be complicated by a late valgus deformity, referred to as Cozen's phenomenon. We studied children with such fractures to determine whether the child's age at the time of injury influenced the development of Cozen's as well as the occurrence of elongation. In addition, we explored whether the deformity resolved at long-term follow-up.

METHODS

We conducted a retrospective study of 33 patients (six months to 14 years old). Mean follow-up was 8.8 years (3 to 25). We measured angulation of the fractured limb post-treatment, at maximum deformity and final follow-up, as well as elongation and compared them with the uninjured limb.

RESULTS

Three of the fractures were treated surgically whereas the rest, nonoperatively. In all, 15 out of 33 fractures developed late valgus deformity between eight and 19 months (mean time 12.5 months). A total of 24 fractures developed elongation. We found no association of either of these with age. Angulation increased to a statistically significant level, from post-treatment to maximum deformity, and then decreased at final follow-up, leaving no statistically significant difference from the initial measurement. The difference in valgus between fractured and uninjured limb increased to a statistically significant level from post-treatment to maximum deformity and then decreased, leaving an excess from the initial measurement.

CONCLUSION

In almost half the patients, late valgus deformity developed within two years post-fracture and corrected to the initial post-treatment angles. Patients should be warned of this possibility and reassured of its natural resolution.

LEVEL OF EVIDENCE

IV.