Long-term Outcomes of Surgically Treated Congenital Dislocation of the Knee.

BACKGROUND: Congenital dislocation of the knee (CDK) may be idiopathic or associated with another condition, such as Larsen syndrome or arthrogryposis. Surgical reduction of type-3 dislocation may require quadricepsplasty (QP) or femoral diaphyseal shortening (FS). Because it is unknown which treatment is more effective, we evaluated long-term outcomes using patient-reported questionnaires and gait analysis, comparing results by surgery type and underlying diagnosis. METHODS: Twelve patients (mean age, 19 mo) were treated surgically for CDK from 1985 to 2015 and studied 9 to 30 years postoperatively. Three participants had idiopathic CDK, 5 had Larsen syndrome, and 4 had arthrogryposis. Eleven knees underwent QP and 7 underwent FS. Participants were evaluated in our movement science laboratory and completed patient-reported outcome questionnaires. Data were compared with healthy, age-matched control values at the same visit. RESULTS: Surgically treated knees had less flexion during swing ( P <0.01), less overall motion ( P <0.01), greater coronal instability ( P <0.04), and slower gait ( P <0.01) compared with controls. QP knees had more instability in midstance ( P =0.03) and less flexion during gait compared with FS knees, less sagittal power generation than controls ( P <0.01), and trended toward lower scores on Knee Injury and Osteoarthritis Outcome and Lysholm Knee Questionnaires than FS patients did. The idiopathic group had the gait most similar to that of controls, followed by the Larsen syndrome group and then the arthrogryposis group. The idiopathic group also had a better UCLA Activity Score ( P =0.03) than the arthrogryposis group did. CONCLUSIONS: Surgical treatment of type-3 CDK will not likely restore normal knee function, suggesting teratologic joint abnormality. In this small series, FS produced better gait mechanics and patient-reported outcomes compared with QP. Not surprisingly, patients with idiopathic CDK had better outcomes than those with a syndromic diagnosis, likely related to having only a single joint affected. LEVEL OF EVIDENCE: Level III.

Interference screw versus suture button fixation for tibialis anterior tendon transfer: a biomechanical analysis.

Tibialis anterior tendon (TAT) transfer to the lateral cuneiform is commonly utilized to treat dynamic supination for relapsed clubfoot deformity. Traditional suture button fixation (SBF) may lead to skin necrosis at the button/skin interface. While interference screw fixation (ISF) would mitigate this concern, this fixation method has not been investigated in clubfoot patients. This study aims to investigate the performance of ISF versus SBF for TAT transfer in a cadaveric model. Ten matched pairs of cadaveric feet were obtained. One of each matched specimen underwent TAT transfer to the lateral cuneiform using ISF and the other underwent TAT transfer using SBF. For each ISF specimen, the tension of the transferred TAT required to bring the ankle to neutral was measured. This tension was then applied to both matched specimens using an MTS machine. Tension dissipation was measured after a 20-minute interval. In specimens with SBF, a load cell was positioned between the plantar skin and suture button to determine plantar skin pressure at the time of initial tension application. Average tension necessary to achieve neutral dorsiflexion was 49.4 N. Average tension dissipation after 20 min was significantly less in the IFS group (20 N versus 23.6 N, P = 0.02). No fixation failures occurred in either group. Average plantar foot skin pressure was 196.5 mmHg at initial tension application, exceeding thresholds for tissue ischemia. ISF allows for tendon tensioning at forces beyond those expected to result in skin necrosis with SBF with less dissipation of tension over time.

Clinical and Radiographic Assessment of Adult Function After Blount Disease in Childhood: An Exercise in Futility.

BACKGROUND: Few studies evaluate long-term function of patients with Blount disease. We sought to document patient radiographic and functional status 20 to 30 years after sugical treatment for infantile or adolescent Blount disease. METHODS: We reviewed the medical records and radiographs of patients operated at our institution for Blount disease between 1985 and 1995. Over a 4-year period, we recruited subjects for an IRB-approved call-back study. RESULTS: One hundred five patients were eligible for the call-back study. Thirty-one (30%) had a criminal record, 18 of sufficient gravity to preclude invitation to return. Of the remaining 87, 40 (46%) could not be contacted. Of 47 with valid contact information, 10 (21%) were reported as deceased (although this could not be objectively confirmed), 20 (43%) did not respond or failed to show for assessment, and 1 (2%) declined to participate. 16 subjects returned at average age 36, 22 to 31 years post-index surgery. Body mass index (BMI) averaged 45.8 (range 23.9 to 67.6). Physical Score correlated most strongly and inversely with BMI ( P <0.01). Satisfaction with life correlated strongly and inversely with mechanical axis deviation ( P =0.02) and radiographic osteoarthritis of the knee ( P =0.02), but not BMI. There also was no correlation between severity of radiographic osteoarthritis and mechanical axis deviation ( P =0.46) or BMI ( P =0.52). CONCLUSIONS: The small fraction of patients returning for evalutation minimize clinical conclusions that can be drawn from this study, despite an intensive 4-year effort to conduct it. Management of obesity and other socioeconomic characteristics are likely the most important aspects of treatment of patients with Blount disease. Our primary conclusion is that meaningful long-term functional studies of pediatric orthopaedic conditions will not be answered by retrospective call-back studies, and must be conducted within prospective registries and regular longitudinal follow-up. LEVEL OF EVIDENCE: III-Case-controlled study.

The Ponseti Method for the Treatment of Clubfeet Associated With Down Syndrome: A Single-institution 18-year Experience.

BACKGROUND: Although the Ponseti method has been used with great success in a variety of nonidiopathic clubfoot deformities, the efficacy of this treatment in clubfeet associated with Down syndrome remains unreported. The purpose of this study is, therefore, to compare treatment characteristics and outcomes of clubfoot patients with Down syndrome to those with idiopathic clubfoot treated with the Ponseti method. METHODS: An Institutional Review Board-approved, retrospective review of prospectively gathered data were performed at a single pediatric hospital over an 18-year period. Patients with either idiopathic clubfeet or clubfeet associated with Down syndrome who were less than 1 year of age at the outset of treatment were treated by the Ponseti method, and had a minimum of 2 year's follow-up were included. Initial Dimeglio score, number of casts, need for heel cord tenotomy, recurrence, and need for further surgery were recorded. Outcomes were classified using the Richards classification system: "good" (plantigrade foot +/- heel cord tenotomy), "fair" (need for a limited procedure), or "poor" (need for a full posteromedial release). RESULTS: Twenty clubfeet in 13 patients with Down syndrome and 320 idiopathic clubfeet in 215 patients were identified. Average follow-up was 73 months for the Down syndrome cohort and 62 months for the idiopathic cohort. Down syndrome patients presented for treatment at a significantly older age (61 vs. 16 d, P =0.00) and with significantly lower average initial Dimeglio scores than the idiopathic cohort (11.3 vs. 13.4, P =0.02). Heel cord tenotomy was performed in 80% of the Down syndrome cohort and 79% of the idiopathic cohort ( P =1.00). Recurrence rates were higher in the Down syndrome cohort (60%) compared with the idiopathic group (37%), but this difference was not statistically significant ( P =0.06). Need for later surgical procedures was similar between the 2 cohorts, though recurrences in the Down syndrome group were significantly less likely to require intra-articular surgery (8.3% vs. 65.5%, P =0.00). Clinical outcomes were 95% "good," 0% "fair," and 5% "poor" in the Down syndrome cohort and 69% "good," 27% "fair," and 4% "poor" in the idiopathic cohort ( P =0.01). CONCLUSIONS: Despite the milder deformity and an older age at presentation, clubfeet associated with Down syndrome have similar rates of recurrence and may have better clinical outcomes when compared with their idiopathic counterparts. When deformities do relapse in Down syndrome patients, significantly less intra-articular surgery is required than for idiopathic clubfeet. LEVEL OF EVIDENCE: Level III.

Lateral Cuneiform Ossification and Tibialis Anterior Tendon Width in Children Ages 3 to 6: Implications for Interference Screw Fixation of Tibialis Anterior Tendon Transfers in Children.

BACKGROUND: While the transfer of the tibialis anterior tendon (TAT) to the lateral cuneiform (LC) following serial casting has been used for nearly 60 years to treat relapsed clubfoot deformity, modern methods of tendon fixation remain largely unstudied. Interference screw fixation represents an alternative strategy that obviates concerns of plantar foot skin pressure-induced necrosis and proper tendon tensioning associated with button suspensory fixation. A better understanding of LC morphology in young children is a necessary first step in assessing the viability of this fixation technique. Therefore, the purpose of this investigation is to define LC morphology and TAT width in children aged 3 to 6 years. METHODS: A retrospective radiographic review of 40 healthy pediatric feet aged 3 to 6 years who had either magnetic resonance imaging or computed tomography scans was performed at a single pediatric hospital. The length, width, and height of only the ossified portion of the LC were measured digitally using sagittal, coronal, and axial imaging. In addition, the maximal cross-sectional diameter of the TAT was measured at the level of the tibiotalar joint. RESULTS: The average ossified LC width ranged from 8.5 mm in the 3-year-old cohort to 10.3 mm in 6-year-old children. Analysis of variance testing revealed no statistically significant difference in width between age groups. Average ossified LC length ranged from 13.5 mm in the 3-year-old cohort to 18.3 mm in 6-year-old children with statistically significant increases in age groups separated by 2 or more years. Significant differences in LC height, volume, and TAT diameter were demonstrated after analysis of variance testing. The TAT to ossified LC width ratio ranged from 44% to 53% across age groups. CONCLUSIONS: The dimensions of the LC ossification center are large enough to allow interference screw fixation in children 3 to 6 years of age. Further studies are needed to investigate interference screw fixation performance in the pediatric clubfoot population. LEVEL OF EVIDENCE: Level IV.

The Ponseti Method for the Treatment of Clubfeet Associated With Amniotic Band Syndrome: A Single Institution 20-Year Experience.

BACKGROUND: Amniotic band syndrome (ABS) is a congenital disorder resulting in fibrous bands that can cause limb anomalies, amputations, and deformities. Clubfoot has been reported in up to 50% of patients with ABS. The purpose of this study is to compare treatment characteristics and outcomes of clubfoot patients with ABS to those with idiopathic clubfoot treated with the Ponseti method. METHODS: An Institution Review Board (IRB) approved retrospective review of prospectively gathered data was performed at a single pediatric hospital over a 20-year period. Patients with either idiopathic clubfeet or clubfeet associated with concomitant ABS who were <1 year of age and treated by the Ponseti method were included. Initial Dimeglio score, number of casts, need for heel cord tenotomy, recurrence, and need for further surgery were recorded. Outcomes were classified as "good" (plantigrade foot±heel cord tenotomy), "fair" (need for a limited procedure), or "poor" (need for a full posteromedial release). RESULTS: Forty-three clubfeet in 32 patients with ABS, and 320 idiopathic clubfeet in 215 patients were identified. Average age at last follow up was not different between ABS and idiopathic cohorts (7.4 vs. 5.2 y, P=0.233). Average Dimeglio score was lower in the ABS cohort (12.3 vs. 13.7, P=0.006). Recurrence rate was significantly higher in the ABS (62.8%) compared with idiopathic cohort (37.2%) (P=0.001). Clinical outcomes were significantly better in the idiopathic cohort (69.4% "good", 26.9% "fair", 3.8% "poor") compared with the ABS cohort (41.9% "good", 34.9% "fair", and 23.3% "poor") (P<0.001). Within the ABS cohort, no significant differences in clinical outcomes were found based upon location, severity, or presence of an ipsilateral lower extremity band. CONCLUSION: Clubfeet associated with ABS have higher rates of recurrence, a greater need for later surgery, and worse clinical outcomes than idiopathic clubfeet. This information may prove helpful in counseling parents of infants with ABS associated clubfeet. LEVEL OF EVIDENCE: Level III.