Purpose of the study: Duplication of the thumb is the most common congenital anomaly of the first ray. The characteristic feature of type IV is the diversity of the clinical forms and the presence of certain complex forms particularly difficult to treat (Hung IVD). We propose a new procedure for reconstruction of IVD type thumb duplication.

Material and method: This new procedure was used for thumb reconstruction in two boys with type IVD thumb duplication. Mean age at surgery was 10 months. Surgical technique. The future incisions were traced with a central skin resection removing the most hypoplastic nail entirely (generally the radial nail). At the bone level, a longitudinal osteotomy of the proximal phalanges was made over the entire length to remove the central part and obtain a width for the first phalanx comparable to that of the contralateral thumb. An oblique osteotomy was cut in the base of the distal phalanx of the ulnar hemithumb with resection of a radial corner. The same type of osteotomy was performed at the base of the distal phalanx of the radial hemithumb, but with preservation of the radial corner and resection of the rest of the radial thumb. The proximal hemiphalanges were sutured as were the bases of the distal phalanges. This produced automatic realignment and stabilisation of the interphalangeal joint without an ungueal intervention.

Results: The three children were reviewed at 24, 18 and 12 months. The Horii score was good in all cases.

Discussion: Type IVD duplications of the thumb are difficult to treat and may leave serious sequelae. Our technique is based on the principle of a central resection of the proximal phalanges associated with partial resection of the base of the distal phalanges. This enables realignment and stabilisation of the interphalangeal joint while avoiding the problem of ungueal dystrophy since only one nail is preserved. Our preliminary results are encouraging but must be confirmed with a longer term study.

Purpose of the study: For symptomatic discoid meniscus, the treatment of choice in children is arthroscopic meniscoplasty. The treatment of associated meniscal lesions remains a subject of debate. The purpose of our work was to evaluate our results with arthroscopic meniscoplasty associated with meniscal repair as needed and the findings of the systematic postoperative MRI.

Material and methods: This was a retrospective series of patients treated by one operator. There were 23 discoid menisci (21 patients) treated from 2004 to 2007 with arthroscopic meniscoplasty followed by a complementary procedure depending on the residual meniscus: abstention if there was no associated lesion, suture or reinsertion for reparable lesions, partial meniscectomy for non-reparable lesions. The Lysholm and Tegner scores, plain x-rays, and MRI were obtained systematically.

Results: Mean age at surgery was 9.8 years. The Watanabe classification was I:9, II:9, III:5. Arthroscopy revealed 15 lesions, including 11 longitudinal tears. Meniscoplasty was performed in 9 cases alone, associated with partial meniscectomy in 6 and with repair in 8 (5 cases of disinsertion and 3 tears). Mean follow-up was 37.1 months. The mean postoperative Lysholm was 87.9, the Tegner 5.9. Outcome was considered satisfactory or very satisfactory by 90% of patients. MRI failed to reveal any signs of chondral degeneration or meniscal tear. There were however four cases of high intensity intra-meniscal signals and one meniscal cyst. Mean measurements of the residual meniscus were: anterior segment 8.6 mm thickness and 2.6 mm height; middle segment 5.5 and 2.3 mm; posterior segment 5.8 and 3.0 mm. One case of osteochondritis of the lateral condyle was noted postoperatively.

Discussion: To our knowledge, there is no other study evaluating the outcome of discoid meniscus surgery with postoperative MRI. There have been few reports concerning meniscoplasty then repair. This approach spares meniscal tissue, essential for children. We obtained good clinical results and patient satisfaction. At the MRI, the residual meniscus had a morphology close to normal. There were no signs of tears. The high intensity signals occurred in patients with good outcome.

Conclusion: Arthroscopic meniscoplasty associated with repair or partial meniscectomy as needed appears to be a good therapeutic solution for discoid meniscus in children.

Purpose of the study: Surgical strategies for high-grade spondylolisthesis are controversial. The main subject of debate concerns the indications for reduction or in situ fusion. We present mid-term results obtained in a series of patients with high-grade spondylolisthesis treated by posterior reduction and fusion.

Material and methods: Sixteen patient who had undergone surgery for spondylolisthesis of the superior isthmus > 50% were reviewed. Mean age was 12 years (range 9–16 years). Preoperatively, all patients were symptomatic with lumbalgia, truncated radicular pain, and gait anomalies. Surgical treatment consisted in a single posterior approach, L5 laminectomy, curettage of the L5-S1 disc combined with excision of the S1 dome, L4-S1 instrumented reduction, anterior L5-S1 and posterolateral L4S1 arthrodesis. Postoperative immobilization was achieved with a resin lumbar cast with crural stabilization for three months then a lumbar orthesis for three months. Clinical and radiographic outcome was assessed at 44 months on average (range 10–260 months).

Results: Clinically, 14 patients were pain free and had resumed their former activities. One patient complained of intermittent pain. No improvement was observed in one patient. Radiographic results were: displacement 78% (range 52–100%) preoperatively and 30% (8–95%) at last follow-up. The L5S1 displacement angle was 14° kyphosis (range 8–30°) preoperatively and 9° lordosis (range 3–12°) at last follow-up excepting one case with complications. The pelvic incidence was 85° (range 65–100°) preoperatively and 74° (range 50–90°) at last follow-up. Complications: There was one early infection treated by wash-out debridement and antibiotics without removing implants. Disassembly of the implanted material in one patient with a poor clinical result led to complete recurrence and lumbosacral kyphosis. Sacral screw fracture was diagnosed in six patients on average one year after surgery but without any progression or recurrence of the displacement. There were no neurological complications.

Discussion and conclusion: Posterior reduction enables restoration of a good sagittal balance. More than the reduction, it is particularly important to restore the lumbosacral junction in a lordosis position to guarantee long-term stability. This technique is a difficult surgical challenge and raises the risk of recurrence and potential neurological complications.