Limb lengthening and deformity correction of congenital and acquired deformities in children using the Taylor Spatial Frame.

Background and purpose - Hexapod ring fixators such as the Taylor Spatial Frame (TSF) have shown good outcomes. However, there have only been a few studies comparing the use of TSF with various etiologies of the deformity. We compared the use of TSF in congenital and acquired deformities in children. Patients and methods - We reviewed 213 lower extremity reconstructive procedures with the TSF in 192 patients who were operated between October 2000 and October 2015. 128 procedures (67 proximal tibiae, 51 distal femora, and 10 distal tibiae) in 117 children (median age 14 (4-18) years; 59 girls) fulfilled the inclusion criteria. 89 procedures were done in children with congenital deformities (group C) and 39 were done in children with acquired deformities (group A). Outcome parameters were lengthening and alignment achieved, lengthening index, complications, and analysis of residual deformity in a subgroup of patients. Results - Mean lengthening achieved was 3.9 (1.0-7.0) cm in group C and 3.7 (1.0-8.0) cm in group A (p = 0.5). Deformity parameters were corrected to satisfaction in all but 3 patients, who needed further surgery for complete deformity correction. However, minor residual deformity was common in one-third of the patients. The mean lengthening index was 2.2 (0.8-10) months/cm in group C and 2.0 (0.8-6) months/cm in group A (p = 0.7). Isolated analysis of all tibial and femoral lengthenings showed similar lengthening indices between groups. Complication rates and the need for secondary surgery were much greater in the group with congenital deformities. Interpretation - The TSF is an excellent tool for the correction of complex deformities in children. There were similar lengthening indices in the 2 groups. However, congenital deformities showed a high rate of complications, and should therefore be addressed with care.

Temporomandibular joint involvement in childhood arthritis: comparison of ultrasonography-assessed capsular width and MRI-assessed synovitis.

OBJECTIVES: Ultrasonography is an effective, low-cost, low-threshold and convenient diagnostic tool in childhood arthritis, but its value in temporomandibular joint (TMJ) involvement is not clear. The purpose of our study was to explore the reliability of ultrasonography to assess TMJ inflammation using contrast-enhanced MRI as reference standard, in order to deduce cut-off values for TMJ capsular width to detect enhanced synovial thickening (synovitis). METHODS: 124 ultrasonography and MRI examinations in 55 patients [mean age 12.4 ± 3.5 years (±standard deviation)], the majority obtained within 1 day, were scored for subcondylar and condylar capsular width (ultrasonography images) and amount of synovitis (MR images). The correlations of these findings were calculated. A receiver operating characteristic (ROC) curve analysis, with MRI findings as reference standard, was obtained. RESULTS: The correlation between ultrasonography-assessed capsular width and MRI-assessed amount of synovitis was moderate both at the subcondylar and condylar level [Spearman's rho (ρ): 0.483; p < 0.001 and 0.347; p < 0.001 respectively]. The ROC curve indicated the best discriminatory ability at the subcondylar level with an area under the curve of 0.77 (95% confidence interval 0.69-0.85) and a cut-off value of 1.2 mm (sensitivity 72%, specificity 70%) for the capsular width. CONCLUSIONS: A moderate correlation between ultrasonography-assessed capsular width and MRI-assessed synovitis was found in childhood arthritis with the best discriminatory ability at the subcondylar level. This indicates that ultrasonography may be a valuable diagnostic tool in the initial assessment of TMJ inflammation.

Good long-term outcome of the untreated contralateral hip in unilateral slipped capital femoral epiphysis : Forty hips with a mean follow-up of 41 years.

PURPOSE: There is no consensus regarding prophylactic fixation of the contralateral hip in slipped capital femoral epiphysis (SCFE). In order to further study this question, we evaluated the long-term natural history of untreated contralateral hips. METHODS: Forty patients treated for unilateral SCFE without evidence of subsequent contralateral slip during adolescence were reviewed with a mean follow-up of 36 years (range 21-50 years). The deformity after SCFE may demonstrate radiographic signs of cam-type femoroacetabular impingement. We, therefore, measured α-angles in the contralateral hips on anteroposterior (AP) and frog-leg lateral radiographs. The angles were compared with those of a control group of adults without SCFE. Five years after the radiographic examination, with a mean follow-up of 41 years, all patients were evaluated by telephone interview. As range of motion and deformity could not be examined, a modified Harris hip score (HHS) (maximum score of 91 points) was used. A modified HHS <76 points and/or radiographic osteoarthritis (OA) was classified as a poor long-term outcome. RESULTS: The mean value of the AP α-angle was significantly higher in the contralateral hips in SCFE patients than in the control group (55° vs. 46°), while the mean value of the lateral α-angle was not. Abnormally high values for one or both α-angles were found in 16 contralateral hips (40 %), of which five patients had abnormal values for both α-angles and were considered to have had an asymptomatic contralateral slip. Five patients (13 %) had a poor outcome in the contralateral hip, of which three patients (8 %) had OA. There was a significant association between hips with both α-angles that were abnormal and poor outcome. CONCLUSIONS: Since the natural history showed good long-term radiographic and clinical outcome in 35 of 40 patients and only three had OA, we conclude that routine prophylactic fixation of the contralateral hip is not indicated.

Fifty-year follow-up of late-detected hip dislocation: clinical and radiographic outcomes for seventy-one patients treated with traction to obtain gradual closed reduction.

BACKGROUND: There is little knowledge concerning outcomes for middle-aged adults who were treated for late-detected developmental dislocation of the hip. The aims of this retrospective study were to evaluate the fifty-year clinical and radiographic results after closed reduction and to identify prognostic factors. METHODS: Seventy-one patients (ninety hips) with late-detected hip dislocation treated between 1958 and 1962 were assessed clinically and radiographically. The primary treatment was skin traction to obtain a gradual closed reduction. The mean age of the patients at the time of the long-term radiographic examination was 51.6 years (range, forty-four to fifty-five years). RESULTS: A stable reduction was achieved in eighty-three hips. The mean age at reduction was 1.7 years (range, 0.3 to 5.4 years). Traction failed in six patients (seven hips [8%]), for whom an open reduction was necessary. Twenty-six patients (thirty hips) underwent late surgical procedures because of residual hip dysplasia. A good long-term clinical outcome (a Harris hip score of ≥85 points) after closed reduction was assessed for fifty-two (63%) of the hips. A satisfactory radiographic outcome (no osteoarthritis) was found for fifty-six (67%) of the hips. Osteoarthritis had developed in twenty-seven (33%) of the hips, of which nineteen had undergone total hip replacement, performed at a mean patient age of 43.7 years (range, thirty-one to fifty-four years). Risk factors for osteoarthritis were an older age at the time of reduction, osteonecrosis of the femoral head, residual subluxation, a high acetabular index during childhood, and a classification of Severin grades III or IV at skeletal maturity. A survival analysis showed a reduction in "surviving" hips (no total hip replacement) from 99% at a patient age of thirty years to 74% at the age of fifty-two years. CONCLUSIONS: With a mean follow-up of fifty years, the clinical and radiographic outcomes after gradual closed reduction by skin traction were satisfactory in approximately two-thirds of eighty-three hips. The most important independent risk factors for a poor long-term outcome were an age of eighteen months or older at the time of reduction, residual subluxation, and osteonecrosis.

Acetabular component anteversion in primary and revision total hip arthroplasty: an observational study.

PURPOSE: In a prospective manner to evaluate the range of acetabular component anteversion actually achieved by the use of a cup positioner in cementless revision and primary THA. METHODS: We operated 71 patients with cementless primary THA, and 26 patients with cementless acetabular revision surgery. We aimed to obtain cup anteversion of 10 to 30° with an impactor-positioner. In all cases we used elevated liners and a ceramic head with diameter 28. At 3 months postoperatively the component versions were measured using CT with the patient in supine position. RESULTS: The acetabular component version in the primary hips ranged from 28° of retroversion to 42° of anteversion with a mean of 17.4 ± 14.0°, while the cup version in the revision hips ranged from 4° of retroversion to 32° of anteversion with a mean of 15.0 ± 9.6°(p=0.427). The anteversion of 40 (56%) of the primary acetabular components were within the target zone of 10 to 30°, while 19 (27%) were below the target zone and and 12 (17%) were above the target range. The anteversion of 19 (73%) of the revision acetabular components were within the target zone, while 6 (23%) were below the target zone and 1 (4%) were above the target range. The differences in distribution between the primary and revision operations were not significant (p=0.183). CONCLUSIONS: The intraoperative estimation of acetabular anteversion by free hand technique in many cases was not within the intended range of 10 to 30° in either primary or revision THA and with no differences between the two series.

Negative correlation between extent of physeal ablation after percutaneous permanent physiodesis and postoperative growth: volume computer tomography and radiostereometric analysis of 37 physes in 27 patients.

BACKGROUND AND PURPOSE: Percutaneous physiodesis in the knee region is a well-established method for treating leg-length inequality. Longitudinal growth in the physis is believed to stop almost immediately after the operation. The extent of physis ablation required has never been investigated by any kind of tomography in humans. Using radiostereometric analysis (RSA), we determined when definite growth arrest occurred after surgery. We also studied the correlation between the extent of physis ablation and postoperative growth. Finally, we assessed any bone bridging across the physis. METHODS: 6, 12, and 30 weeks after surgery, we used RSA to measure longitudinal growth in 27 patients (37 physes) with a mean age of 13 years. CT scanning of the knee region was performed 12 weeks after surgery to measure the percentage of the ablated physis and to determine the distribution of bone bridges across the physis. RESULTS: RSA showed that growth rate was reduced to less than half of the expected rate after 6 weeks. During the next 6 weeks, the growth ceased completely. CT scans revealed a large variation in the extent of ablated physes (17-69%). In the ablated areas, tissues of various densities were mixed with mature bone. Bridges were found both laterally and medially across the physes in all of the patients. There was a negative correlation between the extent of ablation and total postoperative growth (rho = -0.37, p = 0.03). INTERPRETATION: Growth across the physis is effectively stopped by percutaneous physiodesis. RSA is well-suited for observation of this phenomenon. Volume CT scanning can be used to detect bone bridges that cross the physis and to calculate the extent of physis ablation.

Radiographic evaluation of osteoarthritis of the hip: an inter-observer study of 61 hips treated for late-detected developmental hip dislocation.

BACKGROUND AND PURPOSE: Different methods have been used to classify osteoarthritis (OA) of the hip. We evaluated the reliability of different classifications in order to find which grading system is most appropriate for use in clinical practice. PATIENTS AND METHODS: 49 patients (61 affected hips) with late-detected developmental dislocation of the hip (DDH) were studied. The mean age at follow-up was 45 (32-49) years. 3 classifications of OA were compared. The gradings by Kellgren and Lawrence (1957) (K&L) and Croft et al. (1990) are global visual assessments based on osteophytes, cysts, subchondral sclerosis, and narrowing of the joint space. The third classification is based on narrowing in the upper, weight-bearing part of the joint and defines as OA a minimum joint space width (JSW) of less than 2.0 mm at the narrowest part. 2 experienced observers, one radiologist and one orthopedic surgeon, assessed and measured the radiographs. RESULTS: Minimum JSW (< 2.0 mm in 9 hips) gave the best inter-observer agreement (kappa value = 0.87). Using the K&L grading, inter-observer agreement was moderate (kappa = 0.55), but kappa increased when the number of categories was reduced from 5 to 3 (no OA, mild OA, and severe OA). The Croft classification gave similar agreement as the K&L grading. The intra-observer agreement was better than inter-observer agreement, irrespective of the grading system. There was a good accordance between the minimum JSW and the 2 other methods. INTERPRETATION: Joint space narrowing using a minimum JSW of < 2.0 mm as criterion for OA was the simplest and most reproducible classification in long-term follow-up of patients with DDH. A classification based on global visual assessment can be used in addition if only hips with severe OA are included.

Reliability of radiographic parameters in adults with hip dysplasia.

OBJECTIVE: To assess the reliability of radiographic measurements in adults previously treated for developmental dysplasia of the hip (DDH) and to clarify whether these parameters differ according to position of the patient (supine versus standing). MATERIALS AND METHODS: Fifty-one patients (41 females and 10 males) with 63 affected hips were included in the study. The mean follow-up period was 45 (44-49) years in the patients who had not undergone total hip replacement (THR). Anteroposterior radiographs of the pelvis were taken with the patient in the supine and in the standing position. Measurements used for residual hip dysplasia were center-edge (CE) angle and migration percentage (MP). The joint space width (JSW) was measured at three or four locations of the upper, weight-bearing part of the joint, and the shortest distance was termed the minimum joint space width (minJSW). One radiologist and one orthopaedic surgeon, each with more than 30 years of experience, independently measured the radiographic parameters. RESULTS: The limits of agreement (LOA) of the CE angle (mean interobserver difference ± 2SD) were within the range -8 to 7°. The LOA of the MP were in the range -8 to 8% and of the minJSW -0.6 to 1.1 mm. The mean differences in CE angle between supine and standing radiographs (supine - standing) ranged from -1.1 to 0.0° and the mean differences in MP between supine and standing positions were below 1%. The mean positional differences in minJSW were below 0.1 mm and were not statistically significant. CONCLUSION: The interobserver variations with regard to CE angle, MP, and minJSW were moderate, indicating that these are reliable measurements in clinical practice. Femoral head coverage and JSW did not significantly differ between supine and weight-bearing positions.

No difference in long-term trunk muscle strength, cross-sectional area, and density in patients with chronic low back pain 7 to 11 years after lumbar fusion versus cognitive intervention and exercises.

BACKGROUND CONTEXT: Reduced muscle strength and density observed at 1 year after lumbar fusion may deteriorate more in the long term. PURPOSE: To compare the long-term effect of lumbar fusion and cognitive intervention and exercises on muscle strength, cross-sectional area, density, and self-rated function in patients with chronic low back pain (CLBP) and disc degeneration. STUDY DESIGN: Randomized controlled study with a follow-up examination at 8.5 years (range, 7-11 years). PATIENTS AND METHODS: Patients with CLBP and disc degeneration randomized to either instrumented posterolateral fusion of one or both of the two lower lumbar levels or a 3-week cognitive intervention and exercise program were included. Isokinetic muscle strength was measured by a Cybex 6000 (Cybex-Lumex, Inc., Ronkonkoma, NY, USA). All patients had previous experience with the test procedure. The back extension (E) flexion (F) muscles were tested, and the E/F ratios were calculated. Cross-sectional area and density of the back muscles were measured at the L3-L4 segment by computed tomography. Patients rated their function by the General Function Score. OUTCOME MEASURES: Trunk muscle strength, cross-sectional area, density, and self-rated function. RESULTS: Fifty-five patients (90%) were included at long-term follow-up. There were no significant differences in cross-sectional area, density, muscle strength, or self-rated function between the two groups. The cognitive intervention and exercise group increased trunk muscle extension significantly (p<.05), and both groups performed significantly better on trunk muscle flexion tests (p<.01) at long-term follow-up. On average, self-rated function improved by 56%, cross-sectional area was reduced by 8.5%, and muscle density was reduced by 27%. CONCLUSION: Although this study did not assess the morphology of muscles likely damaged by surgery, trunk muscle strength and cross-sectional area above the surgical levels are not different between those who had lumbar fusion or cognitive intervention and exercises at 7- to 11-year follow-up.

Subsidence of callotasis zone in distraction osteogenesis after external fixator removal, measured by RSA.

BACKGROUND AND PURPOSE: In clinical practice, achieved lengthening of a callotasis zone should be maintained after the external fixator has been removed. The common understanding has been that the regenerated bone may subside. To investigate this, we used high-resolution radiostereometric analysis (RSA) with accurate measurement of the lengthening zone. PATIENTS AND METHODS: We assessed the longitudinal subsidence of a callotasis zone after removal of the external fixator in distraction osteogenesis in 16 patients who underwent 17 segmental lengthening operations on the tibia (n = 9) or femur (n = 8). Median lengthening was 32 (6-80) mm. RSA was performed at the end of the consolidation period before the external fixation device was removed, and this was later repeated at a median time of 11 (4-32) weeks after frame removal. RESULTS: A minimal median longitudinal change of 0.01 (-0.28 to 0.60) mm across the lengthening zone occurred in uncomplicated cases. INTERPRETATION: Our results indicate that no subsidence of clinical interest occurs after external frame removal.

Long-term results of HA coated threaded versus HA coated hemispheric press fit cups: 287 hips followed for 11 to 16 years.

INTRODUCTION: There are many studies on the short and medium term results of hydroxyapatite (HA) coated acetabular components, but information on survival in the longer run is sparse. In this paper, we report 11 to 16 years follow up results of HA coated threaded versus HA coated hemispherical press fit cups. PATIENTS AND METHODS: During the years 1988-1993, we performed 323 primary total hip replacements in 276 patients with an HA coated acetabular component. In 128 cases we used a HA coated threaded cup, and in 195 cases a HA coated hemispherical press fit cup was inserted. There were 189 women and 87 men aged 15-79 (mean 48) years. During follow-up, 14 patients died and 21 patients would not come for the follow-up examination as they were doing quite well with their prostheses. These patients were censored at their last control examination. This left 241 patients (287 hips) followed for 11 to 16 (mean 13) years after the operation. RESULTS: During the follow-up period 48 press fit cups and 9 threaded cups were revised, none because of infection. Survival analyses indicated a cumulative survival of the threaded HA coated cup of 0.91 (95% CI: 0.86-0.97) at 16 years with one patient at risk. The cumulative survival of the HA coated press fit cup was 0.74 (0.69-0.80) at 15 years with no patient at risk. The difference is significant (P = 0.0002). Wear and age was significantly associated with revision (P < 0.0001 and 0.0002, respectively), and wear was significantly (P < 0.0001) associated with osteolysis. CONCLUSION: These results indicate that HA coated threaded cups provide satisfactory bony interlock to resist force loads in the long run whereas the HA coated hemispherical press fit cups do not.

Excellent results with femoral revision surgery using an extensively hydroxyapatite-coated stem: 59 patients followed for 10-16 years.

BACKGROUND: The outcome of femoral component revision with either cemented or proximally coated stems has been disappointing, but revision with extensively coated stems has been promising. We report long-term outcome of a grit-blasted titanium stem entirely plasma sprayed with hydroxyapatite (HA), in femoral revision surgery. PATIENTS AND METHODS: During 1988 to 1993, we performed 66 femoral revisions in 65 patients (49 women) aged mean 58 (28-86) years. 3 patients died before the 10-year follow-up and 4 did not come for the follow-up examination because they had no hip problems, as confirmed by telephone and by a written reply. 1 of these, however, was previously controlled at 10 years. Thus, 59 patients (60 hips) were followed by clinical and radiographic analysis for 10-16 years after femoral stem revision. RESULTS: 1 stem was re-revised due to mechanical failure, and none were revised because of infection. We noticed a low degree of proximal bone loss and a low incidence of distal bone hypertrophy. These observations indicate no significant net transfer of stress proximally to distally, and a somewhat physiological weight distribution from the stem to the femoral bone. The bone changes confirmed a well-fixed femoral component in asymptomatic patients. INTERPRETATION: Our findings indicate good long-term results with a fully HA-coated stem in femoral revision surgery.

Excellent results of HA coating on a grit-blasted stem: 245 patients followed for 8-12 years.

We report the outcome of a grit-blasted titanium stem designed for press-fit insertion and entirely plasma sprayed with HA. During the years 1988-1993, we performed 323 primary total hip replacements in 276 patients (189 women) with a HA-coated prosthesis. Their mean age was 48 (15-79) years. During the follow-up, 12 patients died. 19 other patients did not attend the follow-up examination, but had no major symptoms according to telephone interviews and written replies. Thus, 245 patients (291 hips) were followed for a mean of 10 (8-12) years with radiographic and clinical examinations. Only 1 stem was revised due to mechanical failure. None were revised because of infection. Osteolysis was significantly associated with wear, and wear was significantly associated with the size of the femoral head. We found a small amount of proximal bone loss (37/291) and a low incidence of distal hypertrophy of the bone (23/291). These observations indicate an essentially physiological weight distribution from the stem to the femoral bone. The changes in the bone confirmed that the femoral component was well fixed in asymptomatic patients. To conclude, we found excellent 8-12-year results with a fully HA-coated femoral prosthesis designed for press-fit insertion.

Failure of HA coating on a gritblasted acetabular cup: 155 patients followed for 7-10 years.

We report the outcome of 191 acetabular gritblasted titanium cups with a hemispherical design for press-fit insertion and coated with hydroxyapatite. The prosthesis was made of gritblasted titanium entirely coated with hydroxyapatite. 155 patients aged 15-78 years were operated on during the years 1991-1993 and followed for 7-10 years. During this period, 39 cups were revised because of mechanical loosening, a further 9 had radiolucent lines and 2 focal osteolysis. None of these 11 patients had clinical symptoms. Failure was associated with age, wear and radiolucency/osteolysis. At revision, we found that the soft tissues were discolored, and that most of the coating had disappeared. This design of hydroxyapatite-coated cups has a high rate of debonding and failure.