Can acute correction with simultaneous hemiepiphysiodesis of lateral proximal tibia physis prevent recurrence in neglected infantile Blount's disease?

PURPOSE: The treatment of infantile Blount's disease usually includes surgical correction, but high recurrence is still a problem regardless of the procedure. We conducted a cross-sectional study of severely neglected infantile Blount's disease treated with acute correction and simultaneous hemiepiphysiodesis of lateral proximal tibia physis. In this study, we aimed to observe the complication and recurrence. METHODS: This research is an analytical study with a cross-sectional design using retrospective data collection and total sampling. The subjects were patients with neglected infantile Blount's disease treated from 2018 to 2023 in our institution. Follow-up was conducted in 6, 12, 24, and 36 months. RESULTS: A total of 25 legs from twenty patients were recorded. We observed three legs (12.0%) had recurrence. No neurovascular complications and infections were observed. All subjects had significant postoperative improvement of TFA (mean 6.8 ± 0.730 valgus), Drennan angle, MPTA, MTPD, JLCA, and ligamentous laxity grading (p < 0.001). Lower than 5° postoperative valgus overcorrections and preoperative physeal bar were significant factors in patients with recurrence (p = 0.020 and p = 0.010). There was no significant increase in leg-length discrepancy during follow-up (p = 0.052). There were no significant differences between age, BMI, preoperative TFA, pre- and postoperative Drennan angle, MPTA, MTPD, JLCA, Langenskiöld stages, and length of follow-up in patients with recurrence and not. CONCLUSION: Acute correction with simultaneous hemiepiphysiodesis of lateral proximal tibia physis is an effective technique to prevent deformity recurrence in neglected infantile Blount's disease, provided that the postoperative TFA is more than 5° of valgus and no evidence of physeal bar in the preoperative radiograph.

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.

Impact of Proximal Tibial Varus Anatomy on Survivorship After Medial Unicondylar Knee Arthroplasty.

BACKGROUND: Precise indications for medial unicondylar knee arthroplasty (UKA) continue to be defined. It is unclear if patients who have proximal tibia vara should be considered candidates for UKA. The purpose of this study was to evaluate the impact of proximal tibial varus alignment on outcomes after UKA. METHODS: A retrospective review identified 2,416 patients (3,029 knees) who underwent mobile-bearing medial UKA with 2-year minimum follow-up or revision. Preoperative radiographs were evaluated, and medial proximal tibial angle (mPTA) was measured. Patients were grouped into two groups as follows: mPTA <80 degrees and mPTA ≥80 degrees. Analyses were performed on the impact of mPTA on clinical outcomes, all-cause revisions, and tibial failures. RESULTS: At a mean follow-up of 5 years (range, 0.5 years to 12.8 years), there was not a statistically significant difference in clinical outcomes nor increased risk for all-cause revision or tibial failure in patients who had an mPTA <80°. Mean mPTA in patients who had tibial failures was 82.5° and not significantly different than those who did not have a tibial failure (82.9°) (P = .289). Tibial failure rate in knees with an mPTA <80° was 2.2% and not significantly different than knees with an mPTA ≥80° at 1.4% (P = .211). The all-cause revision rate in knees with an mPTA <80° was 5.8% and was not significantly different than knees with an mPTA ≥80° at 4.9% (P = .492). CONCLUSION: Patients who have tibia vara are not at increased risk for tibial related or all-cause failure in medial UKA. This data may allow surgeons to increase their indications for medial UKA.

Predicting Success of Deformity Correction With Tension Band Plating in Early-Onset Tibia Vara.

BACKGROUND: Angular deformity correction with tension band plating has not been as successful in early-onset tibia vara (EOTV) as it has been in other conditions. Our hypothesis is that perioperative factors can predict the success of lateral tibial tension band plating (LTTBP) in patients with EOTV. METHODS: A retrospective review was performed at 7 centers evaluating radiographic outcomes of LTTBP in patients with EOTV (onset <7 y of age). Single-event tibial LTTBP outcome was assessed through medial proximal tibial angle (MPTA). The final limb alignment following comprehensive limb growth modulation (CLGM), which could include multiple procedures, was assessed by mechanical axis zone (MAZone), mechanical tibio-femoral angle (mTFA), and mechanical axis deviation (MAD). Preoperative age, weight, deformity severity, medial physeal slope, and Langenskiöld classification +/- modification were investigated as predictors of outcome. Success was defined as the correction or overcorrection to normal age-adjusted alignment. The minimum follow-up was 2 years except when deformity correction, skeletal maturity, or additional surgery occurred. RESULTS: Fifty-two patients with 80 limbs underwent 115 tibial LTTBP procedures at a mean age of 5.3 y, including 78 primary, 21 implant revisions, and 15 reimplantations for recurrence. Tibial LTTBP resulted in a mean change of +8.6 o in MPTA and corrected 53% of tibias. CLGM resulted in MAD correction for 54% of limbs.Univariate analysis showed that success was best predicted by preoperative age, weight, MPTA, and MAD. Multivariate analysis identified that preoperative-MPTA/MAD and preoperative-weight<70 kg were predictive of MPTA and MAD correction, respectively. The probability of success tables are presented for reference. CONCLUSION: Successful correction of MPTA to age-adjusted norms following a single-event LTTBP occurred in 53% of tibias and was best predicted by preoperative-MPTA and preoperative body weight <70 kg. Comprehensive growth modulation corrected limbs in 54%. The probability of correction to age-adjusted MAD is best estimated by preoperative-MAZone 1 or 2 (MAD ≤40 mm). Limbs with preoperative-MAD>80 mm improved, but ultimately all failed to correct completely with CLGM. Osteotomy may need to be considered with these severe deformities. While modified Langenskiöld classification and medial physeal slope have been shown to predict the outcome of osteotomy, they were not predictive for LTTBP. Change in MPTA was common after physeal untethering. LEVEL OF EVIDENCE: Level-III.

Dysplasia Epiphysealis Hemimelica in the Lower Extremity.

BACKGROUND: Because of the rarity of dysplasia epiphysealis hemimelica (DEH), little is known about the relationship between disease classification and clinical symptoms or patient outcomes. This studies therefore aims to characterize DEH of the lower extremity and correlate radiographic classification to presenting symptomatology and need for surgical intervention. METHODS: A multi-center, retrospective review of all patients with DEH of the lower extremity over a 47-year period was conducted. Demographic data, presenting complaints, treatments, and symptoms at final follow-up were recorded. Radiographs were reviewed to classify lesions using the Universal Classification System for Osteochondromas (UCSO) and document the presence of solitary or multiple lesions within the involved joint. Correlative statistics were used to determine whether presenting complaints, lesion location or radiographic classification predicted the need for surgery or a pain-free outcome. RESULTS: Twenty-eight patients met inclusion criteria with an average age at presentation of 7.8 years. The ankle was the most commonly affected joint with 20/28 patients (71%) having lesions of the talus, distal tibia, or distal fibula. Patients with chief complaints of pain were more likely to undergo surgery than those with complaints of a mass or deformity ( P =0.03). Ankle lesions were more likely to be managed operatively than those of the hip or knee ( P =0.018) and all 12 patients with talar lesions underwent surgery. Neither the number of lesions nor lesion classification was predictive of surgical intervention or a pain-free outcome after surgery. Patients presenting with pain were more likely to have a pain-free outcome (11/14 patients) after surgery ( P =0.023) whereas all patients presenting with deformity who underwent surgery had pain at final follow-up. CONCLUSIONS: Although no single radiographic characteristic of DEH was predictive of surgical intervention or outcome, painful lesions of the ankle, and lesions of the talus were more likely to be managed operatively. Although surgery does not always result in a pain-free outcome, the operative management of painful lesions was more likely to provide a pain-free outcome than surgery for deformity or a mass.

Guided Growth Procedures: Broken Tension Band Implants in Patients With Blount Disease.

BACKGROUND: Tension band plate and screw implants (TBI) are frequently used for temporary hemiepiphyseodeses to manage angular deformity in growing children. The reported implant breakage rate, when TBI is used for deformities in patients with Blount disease, is much higher than when used in other diagnoses. Our hypothesis is that perioperative factors can identify risks for TBI breakage. METHODS: A retrospective case-control study was performed of 246 TBI procedures in 113 patients with Blount disease at 8 tertiary pediatric orthopaedic centers from 2008 to 2018. Patient demographics, age at diagnosis, weight, body mass index (BMI), radiographic deformity severity measures, location, and types of implants were studied. The outcome of implant breakage was compared with these perioperative factors using univariate logistic regression with Bonferroni correction for multiplicity to significance tests. RESULTS: There were 30 broken implants (12%), failing at mean 1.6 years following implantation. Most failures involved the metaphyseal screws. Increased BMI was associated with increased implant breakage. Increased varus deformity was directly associated with greater implant breakage and may be a more important factor in failure for those below 7 years compared with those 8 years or above at diagnosis. There was a 50% breakage rate for TBI with solid 3.5 mm screws in Blount disease with onset 8 years or above of age. No demographic or implant factors were found to be significant. CONCLUSIONS: Breakage of TBI was associated with increased BMI and varus deformity in patients with Blount disease. Larger studies are required to determine the relative contribution and limits of each parameter. Solid 3.5 mm screws should be used with caution in TBI for late-onset Blount disease. LEVEL OF EVIDENCE: Level III.

Guided Growth for Varus Deformity Following Early Tibial Osteotomy in Infantile Tibia Vara-A Multi-Center Study.

BACKGROUND: Despite early osteotomy, many patients with infantile tibia vara (ITV) have persistent or recurrent varus deformity and disordered growth at the medial proximal tibial physis. Our hypothesis was that lateral tibial tension band plating (LTTBP) could guide correction. METHODS: A retrospective review at 6 centers of 15 patients (16 extremities) was performed of LTTBP for varus deformity following early osteotomy in ITV, diagnosed≤4years of age. Correction of deformity parameters on digital standing anteroposterior lower extremity radiographs determined outcome. RESULTS: Twenty-two LTTBP procedures were performed at mean age of 7.5 years, including 4 revisions for implant failure and 2 reimplantations for recurrence. Single event LLTBP, improved the medial proximal tibial angle with a mean change of 13.4 degrees (0.39 degrees/month). Eleven limbs had preoperative mechanical lateral distal femoral angle (mLDFA)>90 degrees. While n degree femoral procedures were performed, at study end, 11 femurs had mechanical lateral distal femoral angle≤90°. Pretreatment, 13 extremities had mechanical axis zone (MAZone) III varus (81%) and 3 had MAZone II varus (19%). LTTBP's were able to initially correct 13 limbs to MAZone I or valgus but 4 limbs rebounded to MAZone II varus after implant removal. Final limb alignment, after all surgeries and rebound, included 9 in MAZone I, 5 in MAZone II varus and 2 in MAZone III varus. Average follow-up was 3.0 years at mean 10.7 years of age. Fifteen procedures resulted in improvement in MAZone and 7 had no change. On average, those that improved were younger (7.3 vs. 8.0 y), weighed less (45.5 kg with body mass index 26.5 kg/m 2 vs. 67.8 kg and body mass index 35.7 kg/m 2 ), had lower mechanical axis deviation (37.1 mm vs. 43.9 mm), lower medial physeal slope (61.7 vs. 68.7 degrees) and had a higher percentage of open triradiate phases (87 vs. 57%). CONCLUSIONS: LTTBP for residual varus, after initial osteotomy in ITV, resulted in 81% of limbs initially achieving MAZone I or valgus with implant failure revisions and femoral remodeling. Rebound after implant removal reduced the corrected rate to 56%. Ninety-four percent avoided osteotomy during the study period. LEVEL OF EVIDENCE: IV.

A comparative study of surgical outcomes between anterior cervical discectomy with fusion and selective laminoplasty for cervical spondylotic myelopathy.

BACKGROUND: Few studies have directly compared anterior and posterior surgical approaches in cervical spondylotic myelopathy (CSM) patients with short-segment disease. We aimed to examine and compare surgical outcomes of anterior cervical discectomy with fusion (ACDF) and selective laminoplasty (S-LAMP) in CSM patients with 1- or 2-level disease. METHODS: Forty-six patients, who received surgeries for CSM, were prospectively investigated; 24 underwent ACDF and 22 underwent S-LAMP. Average follow-up was 3.5 years. The following pre- and postoperative radiographic measurements were recorded: (1) C2-7 angle, (2) local angle (lordotic Cobb angle at operative level), (3) cervical sagittal vertical axis (SVA) (center of gravity of the head-C7 SVA), and (4) C7 slope. Outcomes were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score), neck pain visual analog scale, and neck disability index (NDI). RESULTS: There were no significant differences in patient demographics between the two groups. Postoperatively, C2-7 angle, local angle, cervical SVA, C7 slope, C-JOA score, and neck pain and NDI scores were not significantly different between the two groups; however, the recovery rate of the C-JOA score was superior in the ACDF group (57.5%) compared to the S-LAMP group (42.1%). The recovery rate of the C-JOA score in the local lordosis subgroup (local angle ≥ 0°) showed no significant difference between the two surgical groups. However, in the local kyphosis subgroup (local angle < 0°), C-JOA score recovery rate was worse after S-LAMP (20.4%) than ACDF (57.9%); local angle also worsened postoperatively after S-LAMP. CONCLUSIONS: In patients with local lordosis at the segments of cervical spondylosis and spinal cord compression, S-LAMP showed equivalent surgical outcomes (neurological recovery, neck pain and NDI scores, and cervical alignment) to ACDF. However, in patients with local kyphosis, S-LAMP worsened the kyphosis and resulted in worse neurological recovery.

Posterior Open-wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-free, J-shaped Iliac Crest Bone Graft in Atraumatic Posterior Instability with Pathologic Glenoid Retroversion and Dysplasia: A Preliminary Report.

BACKGROUND: Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery. QUESTIONS/PURPOSES: In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up? METHODS: Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid. All seven patients had a follow-up examination at a minimum of 2 years. The median (range) age at surgery was 27 years (16 to 45) and the median follow-up was 2.3 years (2 to 3). Apprehension was assessed by a positive posterior apprehension and/or posterior jerk test. Patient-reported shoulder scores were obtained and included the subjective shoulder value, obtained by chart review (and scored with 100% representing a normal shoulder; minimum clinically important difference [MCID] 12%), and the Constant pain scale score (with 15 points representing no pain; MCID 1.5 points). Radiographic measurements included glenohumeral arthropathy and posterior humeral head subluxation, bone graft union, correction of glenoid retroversion and glenoid concavity depth, as well as augmentation of glenoid surface area. All endpoints were assessed by individuals not involved in patient care. RESULTS: In four of seven patients, posterior apprehension was positive, but none reported resubluxation. The preoperative subjective shoulder value (median [range] 40% [30% to 80%]) and Constant pain scale score (median 7 points [3 to 13]) were improved at latest follow-up (median subjective shoulder value 90% [70% to 100%]; p = 0.02; median Constant pain scale score 15 points [10 to 15]; p = 0.03). Posterior glenoid cartilage erosion was present in four patients (all four had Walch Type B1 glenoids) preoperatively and showed no progression until the final follow-up examination. The median (range) humeral head subluxation index decreased from 69% (54% to 85%) preoperatively to 55% (46% to 67%) postoperatively (p = 0.02), and in two of four patients with preoperative humeral head subluxation (> 65% subluxation), it was reversed to a centered humeral head. CT images showed union in all implant-free, J-shaped iliac crest bone grafts. The median preoperative retroversion was corrected from 16° (15° to 25°) to 0° postoperatively (-5° to 6°; p = 0.02), the median glenoid concavity depth was reconstructed from 0.3 mm (-0.7 to 1.6) preoperatively to 1.2 mm (1.1 to 3.1) postoperatively (p = 0.02), and the median preoperative glenoid surface area was increased by 20% (p = 0.02). No intraoperative or postoperative complications were recorded, and no reoperation was performed or is planned. CONCLUSION: In this small, retrospective series of patients treated by experienced shoulder surgeons, a posterior J-bone graft procedure was able to reconstruct posterior glenoid morphology, correct glenoid retroversion, and improve posterior shoulder instability associated with pathologic glenoid retroversion and dysplasia, although four of seven patients had persistent posterior apprehension. Although no patients in this small series experienced complications, the size and complexity of this procedure make it likely that as more patients have it, some will develop complications; future studies will need to characterize the frequency and severity of those complications, and we recommend that this procedure be done only by experienced shoulder surgeons. The early results in these seven patients justify further study of this procedure for the proposed indication, but longer term follow-up is necessary to continue to assess whether it is advantageous to combine the reconstruction of posterior glenoid concavity with correction of pathological glenoid retroversion and increasing glenoid surface compared with traditional surgical techniques such as the posterior opening wedge osteotomy or simple posterior bone block procedures. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Dysplasia epiphysealis hemimelica of the radial head: a rare case report.

BACKGROUND: Dysplasia epiphysealis hemimelica (DEH) is a rare benign overgrowth generally affecting the epiphyses and short bones of the lower limbs. DEH in the elbow joint is extremely rare, and to date, only three cases of DEH have been reported in the radial head. CASE PRESENTATION: In this study, we report a case of DEH located in the radial head of the right elbow of a 10-year-old boy, which was presented with elbow pain and limited range of motion. In clinical examination, an asymmetrical enlargement was observed over the elbow. The lesion was resected surgically, and the patient's symptoms resolved afterward. The histologic analysis of the lesion confirmed the diagnosis of DEH. CONCLUSION: This report highlights the role of DEH in the differential diagnosis of elbow pathologies, particularly its differentiation from osteochondroma.

The Medial Elevation Osteotomy for Late-presenting and Recurrent Infantile Blount Disease.

BACKGROUND: Late-presenting or recurrent infantile Blount disease (IBD) is characterized by knee instability because of medial tibial plateau depression, multiplanar proximal tibial deformity, and potential distal femoral deformity. The surgical treatment strategy includes medial elevation osteotomy to stabilize the knee, together with proximal tibial osteotomy to correct alignment, and lateral epiphysiodesis to prevent a recurrence. This study's primary aim was to describe the clinical outcomes of medial elevation osteotomy for the management of late-presenting and recurrent IBD. METHODS: The authors reviewed the records of 48 children (64 limbs) who had medial elevation osteotomies and lateral epiphysiodesis, combined with proximal tibial realignment in 78% (50/64) of cases in the same setting. IBD was bilateral in 33% (16/48), 77% (37/48) were female individuals, and 42% (20/48) were obese. RESULTS: The mean age at surgery was 8.6 years (SD, 1.6; range, 5.8 to 12.8). The mean preoperative tibiofemoral angle (TFA) was 28±11 degrees (8 to 55 degrees), and the mean angle of depression of the medial plateau (ADMP) was 49±8 degrees (26 to 65 degrees). Distal femoral valgus was present in 27% (17/62) and varus in 10% (6/62) children. At a median follow-up of 3.2 years (range, 1 to 6.2 y), the median TFA was 1-degree valgus (interquartile range, 7-degree varus to 5-degree valgus), whereas the ADMP was corrected to 25±8 degrees (8 to 45 degrees). Obesity was associated with more severe deformity as measured by TFA (P<0.001) but did not affect the extent of medial plateau depression (P=0.113). The good or excellent alignment was achieved in 75% (47/63) limbs. Obesity was associated with an increased risk of recurrence [odds ratio (OR), 5.21; 95% CI, 1.26-21.63; P=0.023]. Age at the surgery or previous surgery was not associated with recurrence (OR, 1.29; 95% CI, 0.88-1.88; P=0.195 and OR, 1.22; 95% CI, 0.36-4.17; P=0.746). Obesity and residual instability were associated with an increased risk of poor alignment at the latest follow-up (OR, 3.24; 95% CI, 1.02-10.31; P=0.047 and OR, 1.21; 95% CI, 1.05-1.40; P=0.008). CONCLUSION: Late-presenting or recurrent IBD is a surgical challenge. Obesity is associated with more severe deformity. Medial elevation osteotomy combined with lateral proximal tibial epiphysiodesis and metaphyseal tibial realignment osteotomy will result in restoration of lower limb alignment in a high proportion of cases. The recurrent deformity may be the result of failed epiphysiodesis. Obesity and residual instability are associated with an increased risk of poor alignment. Although complications are rare, surgical measures to decrease risk should be followed. LEVEL OF EVIDENCE: Level IV.

Trochlear Morphology Development: Study of Normal Pediatric Knee MRIs.

INTRODUCTION: Trochlear dysplasia is a known risk factor for patellar dislocations yet normal trochlea development is not well described. This study will define the articular cartilage (AC) and subchondral trochlear morphology development in pediatric patients using magnetic resonance imaging (MRI) evaluation. METHODS: A retrospective knee MRI review included patients aged 3 to 16 years with nonpatellofemoral-related diagnoses. International classification of diseases-9/International classification of diseases-10 codes were used to identify eligible study patients. Measurements of the trochlea were made on the basis of previously established methods using the axial MRI just distal to the physis at the deepest portion of the trochlear groove. Three linear [lateral trochlear height (LTH), medial trochlear height (MTH), and central trochlear height (CTH)] and 3 angular [sulcus angle (SA), lateral trochlear slope (LTS), and medial trochlear slope (MTS)] were made at AC and subchondral bone (SCB). The 12 measurements were made independently by 2 study authors. Inter-rater reliability was assessed using an interclass correlation coefficient for absolute agreement to the average of the scores. Trochlea measurements were summarized across age quartiles defined as first quartile (age, 5.1 to 8.3 y), second quartile (8.3 to 11.5 y), third quartile (11.5 to 14.3 y), fourth quartile (14.3to 16.9 y). Associations between age and trochlea measures were assessed using linear regression with Huber-White-adjusted SEs to account for clustering from a small number of patients (N=16) with >1 MRI. RESULTS: In total, 246 knee MRIs from 230 patients were included in this study; 113 patients (51%) were female, whereas 117 (49%) were male. A total of 116 MRIs (47%) were of the left knee and 130 (53%) were right knee. The average patient age was 11.4±3.4 years. Inter-rater agreement was high across all measures with interclass correlation coefficient values >0.7. Mean values for measurements are presented by age quartiles. LTH, MTH, and CTH showed a linear increase with age (range, 2 to 2.6 cm/y; P<0.001). SA, LTS, MTS measured at AC showed no change with age (P>0.05); however, LTS and MTS measured at SCB showed significant increases with age (0.6 and 0.9 degrees/y; P<0.001), whereas SA showed a decrease with age (-1.4 degrees/y; P<0.001). There were no significant differences found in the age associations by laterality, left versus right. There were no sex differences in the age associations for SA, LTS (P>0.05); however, for MTH, LTH, and CTH, males were found to have a significantly greater growth rate (P<0.001). CONCLUSIONS: This study found an increase in AC and SCB MTH, LTH, and CTH over time, as well as an increase in SCB LTS and MTS, with a decrease in SA. However, AC of the LTS and SA remained constant, with no significant change throughout growth. This normative data indicate that the LTS and SA of AC are predictors of final trochlea shape in normal development. Final trochlear morphologic development is nearly complete around age 12 years, with no significant changes occurring thereafter.

Predictive Factors for Recurrence in Infantile Blount Disease Treated With Tibial Osteotomy.

BACKGROUND: This study aimed to determine the recurrence rate in infantile Blount disease (IBD) in a cohort of patients treated with a tibial osteotomy; and also to identify which factors were associated with recurrence. METHODS: We reviewed the records of 20 patients, under the age of 7 years, with IBD (35 involved extremities) treated by proximal tibial realignment osteotomy to physiological valgus at a single institution over 4 years. We then analyzed the data to determine the rate of recurrence and identify the risk factors for recurrence. RESULTS: The mean age of the included patients was 4.2 years (range, 2 to 6 y). We observed a recurrence rate of 40% (n=14) at a mean follow-up of 42 months (range, 21 to 72 mo). Knee instability [odds ratios OR, 6.6; 95% confidence interval (CI), 2.0-22.2], Langenskiöld stage (OR, 6.3; 95% CI, 2.0-19.4), and severity of the deformity, as measured by medial physeal slope (MPS) (OR, 1.2; 95% CI, 1.1-1.4), were associated with recurrence. On multiple logistic regression analysis, MPS remained the most relevant predictor of recurrence. Receiver operating curve analysis showed that an MPS ≥60 degrees predicted recurrence with a sensitivity of 79% and specificity of 95% (area under the curve=0.925). Postoperatively, increased varus alignment on weight-bearing as measured by the tibio-femoral angle was indicative of knee instability and associated with increased odds of recurrence (OR, 1.5; 95% CI, 1.1-1.9; P=0.004). CONCLUSIONS: We observed a recurrence rate of 40% in children with IBD under 7 years treated with acute correction to a tibio-femoral angle of 5 to 10 degrees valgus through a dome proximal tibial osteotomy. Knee instability, Langenskiöld stage, and MPS were associated with recurrence. Cases with an MPS ≥60 degrees seem to be particularly at risk for recurrence. Further research is needed to validate these findings. LEVEL OF EVIDENCE: Level IV.

Extracorporal noninvasive acute retraction of STRYDE® for continued lengthening in cases with limited nail stroke: a technical less invasive solution to reload the STRYDE®.

With STRYDE® nails (NuVasive Specialized Orthopedics, San Diego, CA), lengthening nails for full weight-bearing during callus distraction have been available CE-certified since February 2019 in Europe. At present only antegrade femur nails and tibia nails with various lengths and diameters are available. Due to a mismatch of bone length and realizable (implantable) nail length e.g., in cases of skeletal dysplasia or achondroplastic dwarfism, it may happen that a desired lengthening of 6-8 cm cannot be realized because of a nail stroke from only 5 cm. Retrograde usage of antegrade piriformis nails is technically possible as an individual (off label use) procedure since so far no retrograde implants are available. A new method of surgical intervention for retraction of the STRYDE nails at the end of the nail stroke with ongoing callus distraction in patients with bilateral femoral extension under anesthesia with extracorporeal use of the fast distractor device is described in detail. It is safe and with low risk for a reload of a capacity of 3-4 cm for antegrade and retrograde femoral implantation situation for the patient. The acute reload of the STRYDE nail stroke for further distraction is possible without skin incision or invasive soft tissue approaches. Application of the fast distractor extracorporeal within a few minutes is described in detail. The intervention is technically reproducible and can be performed for the proximal femur with antegrade STRYDE nails as well as for the distal femur with retrograde STRYDE nails in adult patients.

Trevor's disease of the distal radioulnar joint in two children with achondroplasia.

Two children with achondroplasia who developed an abnormal bony outgrowth at the distal radioulnar joint (DRUJ), indistinguishable from an osteochondroma on histology, but the radiographic appearance, location, and asymmetry suggested the rare diagnosis of dysplasia epiphysealis hemimelica (DEH or "Trevor's disease"). One child experienced symptomatic relief with surgical excision and one was observed clinically due to lack of significant symptoms. These are the first presented cases of DEH in achondroplasia, both affecting the DRUJ. Due to the infrequency of DEH, more research is needed to better understand the potential connection to achondroplasia. For management, we suggest shared surgical decision making based on symptoms.

TKA in the treatment of bilateral dysplasia epiphysealis hemimelica (Trevor's Disease) of the knee in a 50-year-old man: a case report.

BACKGROUND: Dysplasia epiphysealis hemimelica (DEH), also known as Trevor's disease, is a rare skeletal developmental disorder affecting the epiphyses in pediatric patients. DEH is characterized by an asymmetric osteochondral overgrowth arising from either the medial or lateral portion of an epiphysis and usually occurs in the joints of lower limbs, most commonly in the knees and ankles. However, bilateral involvement in an adult is extremely rare, and total knee arthroplasty (TKA) for a patient with DEH has been reported only once before. CASE PRESENTATION: Here, we present a case of bilateral DEH of the knees that caused varus deformity and dysfunction of the lower limbs in a 50-year-old man. TKA was performed for treatment, and the patient had satisfactory function with no angular knee deformity and a normal range of motion after 1 year of follow-up. CONCLUSIONS: The patient in this case exhibited its specific clinical and radiological features of late-term DEH and TKA was proved to be an appropriate procedure for treating the severe deformity caused by this rare disease.

Tension Band Plate (TBP)-guided Hemiepiphysiodesis in Blount Disease: 10-Year Single-center Experience With a Systematic Review of Literature.

BACKGROUND: Primary treatment for Blount disease has changed in the last decade from osteotomies or staples to tension band plate (TBP)-guided hemiepiphysiodesis. However, implant-related issues have been frequently reported with Blount cases. The purpose of our study is to evaluate the surgical failure rates of TBP in Blount disease and characterize predictors for failure. METHODS: We performed an Institutional Review Board-approved retrospective chart-review of pediatric patients with Blount disease to evaluate the results of TBP from 2008 to 2017 and a systematic literature review. Blount cases defined as pathologic tibia-vara with HKA (hip-knee-ankle) axis and MDA (metaphyseal-diaphyseal angle) deviations ≥11 degrees were included in the analysis. Surgical failure was categorized as mechanical and functional failure. We studied both patient and implant-related characteristics and compared our results with a systematic review. RESULTS: In 61 limbs of 40 patients with mean follow-up of 38 months, we found 41% (25/61) overall surgical failure rate and 11% (7/61) mechanical failure rate corresponding to 11% to 100% (range) and 0% to 50% (range) in 8 other studies. Statistical comparison between our surgical failure and nonfailure groups showed significant differences in deformity (P=0.001), plate material (P=0.042), and obesity (P=0.044) in univariate analysis. The odds of surgical failure increased by 1.2 times with severe deformity and 5.9 times with titanium TBP in the multivariate analysis after individual risk-factor adjustment. All 7 mechanical failures involved breakage of cannulated screws on the metaphyseal side. CONCLUSIONS: Most of the studies have reported high failure rates of TBP in Blount cases. Besides patient-related risk factors like obesity and deformity, titanium TBP seems to be an independent risk factor for failure. Solid screws were protective for mechanical failure, but not for functional failure. In conclusion, efficacy of TBP still needs to be proven in Blount disease and implant design may warrant reassessment. LEVEL OF EVIDENCE: Level III-retrospective comparative study with a systematic review.

Blount Disease and Obstructive Sleep Apnea: An Under-recognized Association?

BACKGROUND: Obesity is strongly associated with both Blount disease and obstructive sleep apnea (OSA). Obesity increases risks for anesthetic and postoperative complications, and OSA can further exacerbate these risks. Since children with Blount disease might have both conditions, we sought to determine the perioperative complications and the prevalence of OSA among these children. METHODS: Patients younger than 18 years undergoing corrective surgery for Blount disease were identified from 2 sources as follows: a retrospective review of records at a single institution and querying of the Kids' Inpatient Database, a nationally representative database. RESULTS: At our institution, the prevalence of OSA among patients surgically treated for Blount disease was 23% (42/184). Blount patients were obese (100%), and predominately African American (89%), and male (68%). Patients were treated for OSA before surgery, and 2 patients (1%) had postoperative hypoxemia. In contrast, of 1059 cases of Blount disease from the Kids' Inpatient Database, 3% were diagnosed with OSA. In total, 4.4% of all the Blount children experienced complications, including hypoxemia, respiratory insufficiency, atelectasis, and arrhythmias. Complications were associated with 4.3 additional days of hospitalization (P<0.0001) and 39% additional hospital charges (P=0.002). CONCLUSIONS: Data from the national database showed a low rate of OSA prevalence but high respiratory and OSA-associated complications, perhaps indicating that OSA may be underdiagnosed in children with Blount disease. Affected patients, especially ones with untreated OSA, sustain increased surgical morbidity. A high index of suspicion and preoperative planning helps alleviate the burden of OSA among these patients. LEVEL OF EVIDENCE: Level III-case-control study.

Hemiepiphyseodesis for Juvenile and Adolescent Tibia Vara Utilizing Percutaneous Transphyseal Screws.

BACKGROUND: In juvenile and adolescent tibia vara patients with sufficient growth remaining, implant-controlled hemiepiphyseodesis, or guided growth, can be used to correct deformity. Recent reports have described hardware failure of certain hemiepiphyseodesis implants in overweight patients with tibia vara. We describe our experience using transphyseal screws to correct deformity in this patient population. METHODS: A retrospective chart and radiograph review was conducted on all juvenile and adolescent tibia vara patients who underwent lateral proximal tibial hemiepiphyseodesis using a single transphyseal screw. Charts were queried for preoperative and postoperative mechanical axis deviation, medial proximal tibial angle, lateral distal femoral angle, and postoperative complications or need for further surgery. RESULTS: In total, 14 affected limbs in 9 patients (6 males) who underwent lateral proximal tibial transphyseal screw hemiepiphyseodesis were considered. Average chronologic age at implantation was 10.4 years and average body mass index was 31.7 kg/m. At average 23-month follow-up, the average mechanical axis deviation improved from 46 to 0 mm (P<0.001), and the average medial proximal tibial angle improved from 81 to 92 degrees (P<0.001). No limbs underwent further surgery to correct residual deformity. There were no complications or instances of implant failure associated with the transphyseal screws. CONCLUSIONS: Hemiepiphyseodesis using transphyseal screws is an effective technique to correct deformity in juvenile and adolescent tibia vara patients with sufficient growth remaining. This method can be used safely with few complications and with minimal risk of mechanical failure, even in overweight patients. LEVEL OF EVIDENCE: Level IV-therapeutic.