Reconstruction of forearm deformity by distraction osteogenesis in children with relative shortening of the ulna due to multiple cartilaginous exostosis.

BACKGROUND: In patients with multiple cartilaginous exostosis, distal ulnar osteochondromas frequently cause forearm deformities, with relative ulnar shortening, wrist joint deviation, and varus bowing. Progressive deformation often leads to pain, functional impairment, and cosmetic problems. Surgical ulnar lengthening is necessary to restore the carpal balance. The results of fixator-controlled ulnar lengthening were investigated in this study, using appropriate clinical and radiologic parameters and focusing on medium-term functional and structural outcomes. METHODS: Twelve children (3 boys, 9 girls; mean age 9.8 y) with multiple cartilaginous exostosis-induced ulnar shortening treated with fixator-controlled ulnar callotasis were evaluated retrospectively based on clinical and radiographic examinations preoperatively, after fixator removal, and at a follow-up investigation. Subjective symptoms and objective joint function were assessed clinically, whereas the extent of ulnar shortening, radial articular angle, carpal slip, and radial head dislocation were determined radiographically. RESULTS: The average follow-up period was 24.6 months. The mean ulnar shortening and radial articular angle improved significantly, from 14.3 mm or 38.7 degrees preoperatively to 1.7 mm or 25.6 degrees after fixator removal and showed a slight but significant increase to 5.2 mm or 30.1 degrees at the follow-up. Carpal slip and radial head dislocation remained unchanged. With the exception of radial abduction, no notable functional advancement was observed. One unintended ulnar overlengthening with a subsequent ulnocarpal impaction syndrome, one premature callus consolidation, and two fixator dislocations were noted. CONCLUSIONS: In agreement with literature reports, carpal balance can be restored over the medium term. However, mild recurrences of ulnar shortening and radial malformation were observed during further development. To prevent deformity progression in immature patients, surgery should be carried out early. The optimal timing of surgery needs to be calculated precisely to take advantage of the high remodeling potential and an acceptable degree of recurrent deformity. Ulnar lengthening is necessary, but overcorrection is inadvisable due to possible ulnocarpal impaction syndrome. As significant remodeling effects on the radius were observed, simultaneous radial correction procedures are not recommended a priori.

The postoperative patella height: a comparison of additive and subtractive high tibial osteotomy in correcting the genu varum.

INTRODUCTION: Intraligamentary correctional operations like a high tibial osteotomy were performed in genua valga to prevent later medial gonarthrosis especially in younger patients. An unwanted effect of this method seems to be the inferiorization of the patella. This is feared because of the complications in case of subsequent alloarthroplasty. Besides the classical Coventry method as a subtractive osteotomy the hemicallotasis has been established as a sustainable additive procedure. This means a gradual open wedge correction using an external fixateur. OBJECTIVE: The aim of this study was to determine the position of the patella pre- and postoperatively and in follow-ups with subtractive versus additive intraligamentary high tibial osteotomies on the basis of five radiological parameters. It was expected that an additive osteotomy leads to an inferiorized patella position whereas a subtractive osteotomy leads postoperative to a higher position of the tibia. METHOD: Between 1990 and 2001, 54 patients (61 legs) had undergone an operation due to a genu varum either by the subtractive osteotomy (n = 30) according to Coventry's method or the additive gradually hemicallotasis (n = 31) with an external fixator. RESULTS: In coherence with the Coventry's osteotomy a significant inferiorization of the postoperative patella position with all five radiological parameters was observed, the hemicallotasis showed no operation-related significant alteration of the patella height. Instancing the Insall-Salvati Index there were four (12.9%) preoperative and three (9.7%) postoperative patella baja positions detected. Along with the subtractive osteotomy there were 5 preoperative patellae baja (16.7%) and 11 postoperative patellae baja (36.7%) positions. Furthermore a significant interrelation was noticed between the extent of the correctional angle and the postoperative alteration of the patella. CONCLUSION: The results are surprising, contrary was expected. First this can be explained by its gradual, additive correctional property in contrast to the spontaneous correction by the conventional method according to Coventry, second by the postoperative treatment, which allows an early mobilization and active remedial gymnastics, provided an impact resistant osteosynthesis by a fixateur externe is given. In the case of the additive hemicallotasis an intraligamentary osteotomy is recommended. Technically expensive step cuts in order to osteotomize below the tuberositas tibiae are not necessary. Due to the low quota of complications and the small operative expense the continuous distraction is preferential to ad hoc correction. A postoperative patella baja position has not to be afraid in hemicallotasis.

Estimation of patient dose and associated radiogenic risks from limb lengthening.

UNLABELLED: Limb-lengthening procedures include a series of radiographic examinations to follow the lengthening process and callus formation. We quantified ionizing radiation exposure during lengthening treatment and estimated the risks associated with this exposure in 53 patients undergoing lengthening procedures. Field size and tube voltage of all radiographs and fluoroscopy time during surgery were recorded. According to conversion factor tables of organ doses, the cumulative organ dose was estimated. Location of lengthening, age, complications during lengthening procedure, range of lengthening, healing index, and other factors affecting the duration of the lengthening procedures were analyzed. Average lengthening was 4.8 cm (range, 3.0-12.5 cm). The average cumulative organ dose for a straight lengthening procedure was 3.1 mSv (range, 0.2-12.5 mSv). The average organ dose per centimeter of lengthening was 0.7 mSv/cm (range, 0.03-5.9 mSv/cm). Doses for patients with tibial lengthening (0.3 mSv/cm) were less than doses for patients with femoral lengthening (1.1 mSv/cm). Age, complications, range of lengthening, and healing index did not influence the dosage of radiation per centimeter lengthening. We judge the average patient's exposure during a limb-lengthening procedure as tolerable, but femur lengthening results in a higher cumulative organ dose. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.