[Teenagers with torticollis]. / Tieners met een torticollis.

Teenagers with torticollis In this article we describe three cases of children with torticollis. A 17-year-old patient who appears to have Klippel-Feil syndrome and is treated conservatively. An 11-year-old-patient with torticollis, present since a fall two days earlier and attributed to a subluxation of C1-C2. Ultimately, she had to be treated surgically with an atlantoaxial spondylodesis and has made a good recovery. Finally, a 15-year-old who presents with torticollis which has been present from early childhood. The diagnosis neglected congenital muscular torticollis is made. Because of increasing discomfort she is treated surgically with release of the sternocleidomastoideus. Postoperative, the patient has fewer symptoms. Physicians should be aware of different causes when there is persistent torticollis. Furthermore, children presenting with posttraumatic torticollis require a strict follow-up because atlanto-axial subluxation can lead to permanent deformity.

Malunion of the distal radius in children: accurate prediction of the expected remodeling.

PURPOSE: Malunions of fractures in children have a natural tendency to remodel. However, quantitative data of this well-known process are scarce. The extent of the correction depends inter alia on the type of bone and the location of the deformity and growth remaining. The aim of this study was to quantify the remodeling process of distal radius malunions in children to allow better future prediction. METHODS: Data were derived from two published patient series. Analysis included 63 malunions of distal radius fractures in 62 children (38 boys), with a mean age of 8.5 years (range 2-14.5 years). RESULTS: The mean initial dorsovolar angulation was 25º [standard deviation (SD) 7.8°], remodeling time 22 (SD 18) months, and angulation at follow-up 6.7° (SD 5.8°). Based on these findings, the remodeling process can be described as an exponential function with angulation (A 0) as a factor and the remodeling time (RT) as a negative exponent of e (R (2) = 0.47). The function allows accurate prediction of the expected correction in over 76 % of the malunions. From this model, a formula was derived for calculation of the time needed for complete remodeling, but this formula lacked precision when compared to findings in the literature and needs to be validated. CONCLUSIONS: The remodeling of distal radius malunions can be described as an exponential function with starting speed dependent on the initial angulation. The current model proves to be more accurate than models described previously in the literature. These findings allow for better patient information and optimal planning of eventual surgical intervention. The postulated model could serve as a basis for the description of correction of other malunions by adaptation of the coefficients in this model.

Rheological characterization of the nucleus pulposus and dense collagen scaffolds intended for functional replacement.

Lumbar discectomy is an effective therapy for neurological decompression in patients suffering from sciatica due to a herniated nucleus pulposus (NP). However, high numbers of patients suffering from persisting postoperative low back pain have resulted in many strategies targeting the regeneration of the NP. For successful regeneration, the stiffness of scaffolds is increasingly recognized as a potent mechanical cue for the differentiation and biosynthetic response of (stem) cells. The aim of the current study is to characterize the viscoelastic properties of the NP and to develop dense collagen scaffolds with similar properties. The scaffolds consisted of highly dense (0.5%-12%) type I collagen matrices, prepared by plastic compression. The complex modulus of the NP was 22 kPa (at 10 rad s(-1)), which should agree with a scaffold with a collagen concentration of 23%. The loss tangent, indicative of energy dissipation, is higher for the NP (0.28) than for the scaffolds (0.12) and was not dependent of the collagen density. Gamma sterilization of the scaffolds increased the shear moduli but also resulted in more brittle behavior and a reduced swelling capacity. In conclusion, by tuning the collagen density, we can approach the stiffness of the NP. Therefore, dense collagen is a promising candidate for tissue engineering of the NP that deserves further study, such as the addition of other proteins.

[Diagnostic image (350). A woman with a swollen knee. Clear cell sarcoma]. / Diagnose in beeld (350). Een vrouw met een gezwollen knie. Heldercellig sarcoom.

A 31-year-old woman presented with a slowly growing mass anterior from the right patella, due to a clear cell sarcoma.

[Three previously healthy persons with a stress fracture]. / Drie tevoren gezonde personen met een vermoeidheidsfractuur.

A 42-year-old man presented with a one-month history of pain in his left knee, due to a fracture of the left medial tibia plateau, following a footrace. A 24-year-old man, also a jogger, had had increasing pain in his right lower leg for 4 months, which turned out to be due to a fracture of the posteromedial border of the tibia at the insertion of the flexor digitorum longus muscle. A 35-year-old woman presented with pain in her left foot and ankle that was due to a march fracture of the second metatarsal bone after over 5 hours of intermittent use of the clutch in a traffic jam. In all 3 patients, temporary cessation of the causative activity was sufficient for complete recovery after 3 months. Stress fractures are easily missed on X-rays. Treatment is conservative and consists of the elimination of causative factors to allow adequate healing. In selected cases, a splint or brace may be indicated. Furthermore, certain high risk and displaced fractures should be considered for surgical fixation. Return to the causative activity should be gradual with attention being paid to other potential risk factors.

Basilar impression in osteogenesis imperfecta: can it be treated with halo traction and posterior fusion?

Basilar impression (BI) and hydrocephalus complicating osteogenesis imperfecta (OI) is usually treated by anterior transoral decompression and posterior fixation. Nevertheless, it may be questioned if posterior fusion following axial halo traction is adequate in patients with symptomatic BI complicating OI. We report on a case with progressive symptomatic hydrocephalus and BI complicating OI that was successfully treated by halo traction followed by posterior occipitocervical fusion. However, after a symptom free interval of 2 years the patient suffered from recurrence of symptomatic hydrocephalus needing additional ventriculoperitoneal (VP) shunt placement. In conclusion, posterior fusion without additional VP shunt placement may not be effective in the long term for ameliorating symptoms and signs and halting progressive hydrocephalus in BI complicating OI.

[Three patients with a Spitz naevus that later turned out to be a melanoma]. / Drie patiënten met op Spitz-naevus gelijkende afwijkingen die later een melanoom bleken te zijn.

A melanocytic lesion was removed from each of three patients: 2 men aged 37 and 65 and 1 woman aged 45. The preferred diagnosis was 'Spitz naevus'. Subsequently, all three developed regional (sub)cutaneous and/or lymph node metastases, indicating that the lesions were melanomas. The histopathological distinction between Spitz naevus and melanoma is often very difficult. Classical Spitz naevi can be diagnosed correctly only if the entire lesion is available for histological examination. Incompletely removed lesions should be re-excised for further examination. Some melanomas resemble Spitz naevi, but can be recognised on the basis of well-defined histological indicators of malignancy. Some melanocytic lesions, however, cannot be categorised with confidence as being either benign (Spitz naevus) or malignant (spitzoid melanoma). Thus, a group of lesions with inconclusive histology remains and has been designated as 'atypical Spitz tumour' or 'Spitz tumour of uncertain malignant potential'. Generally, such lesions are best treated as melanomas.