Duk Yong Lee

Effect of tibial lengthening on the gastrocnemius muscle: A histopathologic and morphometric study in rabbits

We observed the changes of the gastrocnemius muscle in relation to the percentage of lengthening of the rabbits tibia by callotasis. 75 rabbits were separated into 3 lengthening groups, 10, 20, and 30 percent lengthening, respectively. Histopathologic observations, based on the fiber size variation, internalization of the nuclei, degeneration, regeneration, and endomysial fibrosis of muscle fibers, revealed that substantial changes occurred in the latter groups. Histomorphometrically, the decrease in the mean size of Types I and II muscle fibers was observed in all lengthening groups, but there was no significant change in the proportion of the muscle fiber types in any of the lengthening groups.

Surgical treatment of the severe sequelae of infantile septic arthritis of the hip.

We retrospectively reviewed 45 hips in 43 patients with severe sequelae of infantile septic arthritis of the hip to compare the efficacy of various hip reconstructive and salvage surgeries, and to propose an algorithmic treatment protocol for the different types. Ten hips were classified as Choi Type IIIA, three as Type IIIB, 14 as Type IVA, and 18 as Type IVB sequelae. A total of 78 hip surgeries and 18 limb-length equalizations (three contralateral femoral epiphysiodesis and 15 ipsilateral femoral and/or tibial lengthenings) were done. The first surgical reconstructions were done at an average age of 5.9 years (range, 1.1–14.8 years), with a 9.5-year average followup. Type IIIA hips had better functional results than the other types. In Type III hips, early realignment osteotomy of the proximal femur or bone-grafting of the pseudarthrosis was indicated. In Type IVB hips, satisfactory results were observed in only five of 10 hips treated by trochanteric arthroplasty compared with satisfactory results in all four hips treated by Ilizarov’s hip reconstruction osteotomy. The latter operation seems to be better indicated in older patients with Type IVB hips, or with Type IVA hips in which previous reconstructive surgery was unsuccessful. Level of Evidence: Prognostic study, Level II-1 (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.

ASSESSMENT OF COMPLEX HIP DEFORMITY USING THREE-DIMENSIONAL CT IMAGE

We used three-dimensional computed tomography (CT) to define the bony configuration of the acetabulum and the proximal femur and their relationship to complicated and/or neglected congenital hip dislocations and Legg-Calvé-Perthes disease. Three-dimensional CT was useful for preoperative planning and postoperative evaluation of hips with complex deformities, which were often difficult to assess by means of plain radiographs or conventional two-dimensional CT. The coverage of the femoral head under the acetabular roof and the severity of the hip dysplasia could be assessed easily with three dimensional CT, and acetabular and femoral torsion could be measured.

Longitudinal growth of the rabbit tibia after callotasis

We investigated the effect of bone lengthening by callotasis on longitudinal growth of the tibia in rabbits. Ninety-nine five-week-old immature rabbits were divided into five groups according to the percentage of lengthening: group I, 10%; group II, 20%; group III, 30%; group IV, 40%; and group V, sham operation without lengthening. Corticotomy was performed at the proximal metaphysis of the left tibia and the right tibia was used as a control. The lengthening rate was 0.25 mm twice daily. Radiological, histomorphometric, and immunohistochemical studies were done on animals killed at the time of corticotomy, at the completion of lengthening, and thereafter every two weeks until 12 weeks. Tibial lengthening did not cause retardation of growth when the bone was lengthened by up to 20%. When the bone was lengthened by 30% or more, growth retardation was evident, and persisted until skeletal maturity.

Fixed pelvic obliquity after poliomyelitis : Classification and management

We classified fixed pelvic obliquity in patients after poliomyelitis into two major types according to the level of the pelvis relative to the short leg. Each type was then divided into four subtypes according to the direction and severity of the scoliosis. In 46 patients with type-I deformity the pelvis was lower and in nine with type II it was higher on the short-leg side. Subtype-A deformity was a straight spine with a compensatory angulation at the lower lumbar level, mainly at L4-L5, subtype B was a mild scoliosis with the convexity to the short-leg side, subtype C was a mild scoliosis with the convexity opposite the short-leg side, and subtype D was a moderate to severe paralytic scoliosis with the convexity to the short-leg side in type I and to the opposite side in type II. A combination of surgical procedures improved the obliquity in most patients. These included lumbodorsal fasciotomy, abductor fasciotomy and stabilisation of the hip by triple innominate osteotomy with or without transiliac lengthening. In patients with type ID or type IID appropriate spinal fusion was usually necessary.

Changes in somatosensory-evoked potentials in limb lengthening. An experimental study on rabbits' tibiae.

To assess the influence of the rate and amount of distraction on the electrophysiologic function of the peripheral nerve during limb lengthening, somatosensory-evoked potential (SSEP) studies were performed on the hindlimbs of 96 rabbits. In Group I, the tibiae were lengthened 0.35 mm per day; in Group II, 0.7 mm per day; in Group III, 1.05 mm per day; and in Group IV, 1.4 mm per day. The studies were done preoperatively and then postoperatively, until six weeks in Group I, five weeks in Group II, four weeks in Group III, and three weeks in Group IV. As lengthening proceeded, the P1 (the first major positive peak) latency gradually increased, whereas the amplitude decreased. Significant amplitude changes were observed at six-weeks postsurgery in Group I, three weeks in Group II, two weeks in Group III, and one week in Group IV. Significant changes in P1 latency were observed at four weeks postsurgery in Group II, three weeks in Group III, and two weeks in Group IV. Greater percentage increases in tibial length corresponded to more marked changes in P1 latency and amplitude. The SSEP monitoring may serve as an effective tool for early detection of neurologic dysfunction during limb lengthening.

Optimum ratio of distraction in double level tibial lengthening.

The authors reviewed 43 double level tibial lengthenings by Ilizarov technique in 34 consecutive patients (6-31 years old), and investigated the factors affecting regenerate bone healing to determine the optimum ratio of distraction rate or magnitude of lengthening at the proximal and distal osteotomy sites. Length gain averaged 6.1 cm (range, 2.5-12.3 cm), equivalent to a 28% increase of the segment. The variables investigated included age, gender, concomitant deformity correction, etiology, and the amount of length gain. The healing index averaged 1.8 months per centimeter proximally and 2.8 months per centimeter distally. Age and the amount of length gain affected the healing index at proximal and distal lengthening sites. However, the proximal to distal healing index ratio, which averaged 0.72, was not affected by any parameters investigated. This study suggests that to minimize external fixation treatment time, the distraction rate, or amount of length gain, of the distal osteotomy site should be approximately 3/4 that of the proximal site in the double level tibial lengthening.

Fixed Pelvic Obliquity After Poliomyelitis: Classification And Management

We classified fixed pelvic obliquity in patients after poliomyelitis into two major types according to the level of the pelvis relative to the short leg. Each type was then divided into four subtypes according to the direction and severity of the scoliosis. In 46 patients with type-I deformity the pelvis was lower and in nine with type II it was higher on the short-leg side. Subtype-A deformity was a straight spine with a compensatory angulation at the lower lumbar level, mainly at L4-L5, subtype B was a mild scoliosis with the convexity to the short-leg side, subtype C was a mild scoliosis with the convexity opposite the short-leg side, and subtype D was a moderate to severe paralytic scoliosis with the convexity to the short-leg side in type I and to the opposite side in type II. A combination of surgical procedures improved the obliquity in most patients. These included lumbodorsal fasciotomy, abductor fasciotomy and stabilisation of the hip by triple innominate osteotomy with or without transiliac lengthening. In patients with type ID or type IID appropriate spinal fusion was usually necessary.

Triple innominate osteotomy for hip stabilisation and transiliac leg lengthening after poliomyelitis

We reviewed our experience with a modified triple innominate osteotomy for hip instability and limb shortening due to poliomyelitis in 62 adolescent and adult patients, treated from 1973 to 1990. Their ages at surgery ranged from 12 years to 35 years (average 22.3). At a mean follow-up of 4 years (2 to 18) 59 of the patients (95.2%) had substantial improvement in hip stability, and all but one had radiological improvement as determined by the acetabular angle, centre-edge angle and acetabulum-head quotient. In 59 cases in which transiliac limb lengthening was attempted, the mean gain was 1.7 cm (0.6 to 3.0). When the abductor muscles had been partially paralysed, the operation produced an appreciable increase in power in 12 of the 39 hips examined.

Fibrodysplasia Ossificans Progressiva

Fibrodysplasia ossificans progressiva(FOP)는 연조직의 진행성 이소성 골경화를 특징으로 한다. 상염색체 우성 유전을 따르지만 대부분의 FOP 환자는 ACVR1 유전자의 새로운 돌연변이로 인해 나타난다. 아주 작은 외상조차도 연조직의 영구적인 골경화를 유발할 수 있기 때문에 일반적인 치과치료에 의해서도 합병증이 생길 수 있다. FOP 환자의 치과치료 시 전달마취, 과도한 근육의 스트레칭, 생검 등은 모두 금기이다. 현재까지 알려진 FOP의 효과적인 치료법은 없다. FOP는 유병률이 매우 낮으며 초기에는 오진되는 경우가 많아 부적절한 처치로 인해 증상을 더욱 악화시키는 경우가 많다. 따라서 조기진단 및 합병증 발생을 줄이기 위한 예방적 조치가 가장 중요하다. 본 증례는 서울대학교병원 소아정형외과에서 특발성 FOP로 진단을 받고 하악 좌, 우측 유중절치의 만기잔존을 주소로 소아치과에 의뢰된 8세 1개월의 남아에서 증상의 악화없이 치과치료를 시행하였기에 이와 관련하여 FOP환자의 특징적 소견 및 치과치료 시 고려사항을 고찰하기 위함이다. 【Fibrodysplasia ossificans progressiva(FOP) is characterized by episodes of permanent heterotopic ossifications of soft tissues throughout the body. FOP is inherited in an autosomal dominant pattern, but most cases result from new mutations in the ACVR1 gene. Even minimal trauma can cause permanent ossifications of soft tissues and give rise to complications following routine dental care. Dental block anesthesia, severe stretching of the jaw and biopsies are all contraindicated in children with FOP. There is no effective treatment. Since the prevalence of FOP is very low and most patients with FOP are misdiagnosed during childhood, they undergo dangerous and unnecessary treatment that can lead to permanent harm. For patients with FOP, early diagnosis and prevention of complications are most important. This study aims at contemplating the characteristic features and consideration factors for the dental treatment of FOP patients in relation to the case of an eight years-and-one month old boy who was referred to Pediatric Dentistry due to prolonged retention of mandibular right and left deciduous central incisors after being diagnosed with sporadic FOP at Pediatric Orthopaedics, Seoul National University Hospital, and received dental treatment without the exacerbation of the FOP symptoms.】