Deformity Correction: Do Osteochondral Lesion of the Talus and Tibia Change After Realignment Surgery?

Malalignment of the lower limb, distal tibia, foot, and hindfoot can all contribute to altered biomechanics in the ankle joint, resulting in increased focal pressure. The development of some osteochondral lesions of the ankle joint may share a similar pathophysiology, where eccentric loading to the talus or tibia within the ankle joint can lead to cartilage injury or adaptive changes. While the association between malalignment and the development of osteochondral lesions of the ankle joint may seem intuitive, the impact of realignment procedures on these lesions and patient symptoms remains a relatively underexplored topic in the literature. A comprehensive understanding of the potential role of realignment surgery in managing osteochondral lesions of the talus and tibia is crucial for advancing our knowledge of this challenging pathologic condition.

Intramedullary nailing of femoral shaft fractures: an analysis of rotational malunions using 3D EOS.

PURPOSE: Rotational malalignment and leg length discrepancy after intramedullary nailing of femoral shaft are frequent. This study has three objectives: evaluate the rate of femoral rotational malalignment and leg length discrepancy using EOS imaging after antegrade intramedullary nailing of femoral shaft fracture, find a relevant clinical examination to detect malrotation and identified risk factors. METHODS: We performed a retrospective single-centre study between January 2014 and January 2022. Fifty-eight patients were clinically and radiographically assessed at a minimum of three months. RESULTS: The femoral rotation of the operated side was significantly greater by a mean of 15.4° in internal rotation compared to the healthy side. There was no statically significant difference for the femoral length (p = 0.08). CONCLUSION: When using EOS stereography following antegrade intramedullary nailing of post-traumatic diaphyseal femur fractures, a statistically significant difference of more than 15.4° in internal rotation was found for femoral rotation on the operated side compared to the healthy side.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [B. Poirot] Last name [Seynaeve]. Also, kindly confirm the details in the metadata are correct.The last name of the first author was corrected : Given name = B. and last name = Poirot Seynaeve The details in matadata are correct LEVEL OF EVIDENCE: III.

Flouroscopic Control of Tibial Torsion After Intramedullary Nailing: A Technical Trick.

SUMMARY: After intramedullary nailing of tibia shaft fractures, torsional malalignment greater than 10 degrees occur in up to 41% of operated legs. The reason is the difficult clinical assessment of rotation intraoperatively, the large variation in absolute torsion of the tibia, and the absence of established reliable methods to fluoroscopically evaluate tibial rotation and compare with the contralateral side. We present here a fast and low-tech intraoperative method on how to achieve identical tibial torsion of the operated and noninjured side. The method can be used for tibia shaft and metaphyseal fractures and only requires a normal C-arm fluoroscope with 2 monitors. First, a true lateral image of the knee on the noninjured side with the femoral condyles aligned is obtained. Second, with the leg and the C-arm rotation and tilt fixed, the fluoroscope is moved parallel to the patient axis and a lateral ankle image is obtained and saved. The fibula position relative to the tibia at the level of the Volkmann tubercle on the lateral view defines the torsion of the tibia. The sequence described above is repeated on the operated side after implantation of the nail before proximal locking. On the operated side, the fibula position relative to the tibia should be identical to the noninjured side before proximal locking takes place. Otherwise, a rotational malalignment is present and must be corrected. The comparison between operated and noninjured side is easy on a fluoroscope with 2 monitors. The complete examination takes a few minutes and has minor additional radiation exposure. We performed the intraoperative torsion control in 10 patients and performed a postoperative low-dose Computer Tomography-control of the torsion of both legs and found the rotational deformity to be less than 10 degrees in all patients.

False malalignment after computer-navigated total knee arthroplasty.

BACKGROUND: Although computer navigation has improved component alignment in total knee arthroplasty (TKA), radiographic outliers are reported with a wide range in literature even using this technique. We hypothesized that the postoperative malalignment after computer-navigated TKA was partially derived from the inherent problems with two-dimensional (2D) measurement such as inaccuracies in measurement due to the knee position during the radiographic examination and the direction of the X-ray beam. We therefore conducted this study to determine how often knees with malalignment on 2D imaging were truly mal-aligned on three-dimensional (3D) reconstructed imaging. METHODS: Sixty-two computer-navigated primary TKAs performed in 47 patients were included in this study. In all cases, a weight-bearing long-leg radiograph was obtained after TKA. 3D measurements were performed for outliers 2° or more in coronal alignment of the femoral or tibial component. RESULTS: For the 18 femoral mal-aligned components on 2D imaging, eight (44.4%) were not truly mal-aligned on 3D imaging (P = 0.0014). For the eight tibial mal-aligned components on 2D imaging, all knees (100%) were not truly mal-aligned on 3D imaging (P < 0.0001). CONCLUSIONS: A considerable number of the false malalignments were included on 2D measurement. Postoperative component alignment in the computer-navigated TKA might be much better than previously reported.

Tibial component coverage affects tibial bone resorption and patient-reported outcome measures for patients following total knee arthroplasty.

PURPOSE: The aim of this study is to investigate the prognostic value of tibial component coverage (over-hang and under-hang) and the alignment of total knee arthroplasty (TKA) components 1 week after surgery. We select patient-reported outcome measures (PROMS) (the Knee Society score (KSS score) and the Western Ontario and McMaster Universities Osteoarthritis Index-pain score (WOMAC pain score)) and tibial bone resorption (TBR) 2 years after surgery as the end points. METHODS: The study retrospectively analyzed 109 patients undergoing TKA (fixed-bearing prosthesis with asymmetrical tibial tray) from January 2014 to December 2017 in Huashan Hospital. By using standard long-leg X-rays, anteroposterior (AP) and lateral X-rays of the knee, tibial component coverage (under-hang or over-hang), AP tibial-femoral anatomical angle (AP-TFA), AP femoral angle (AP-FA), AP tibial angle (AP-TA), and lateral tibial angle (L-TA) were measured at 1 week after surgery, while TBR was measured through postoperative 1-week and 2-year AP and lateral radiographs of the knee on three sides (medial side, lateral side on AP radiograph, and anterior side on lateral radiograph). The Pearson correlation analysis, simple linear regression, multiple linear regression, the Student's t test, and one-way ANOVA together with Tukey's post hoc test (or Games-Howell post hoc test) were used in the analyses. RESULTS: Tibial under-hang was more likely to appear in our patients following TKA (42%, medially, 39%, laterally, and 25%, anteriorly). In multivariate linear regression analysis of TBR, tibial under-hang (negative value) 1 week after surgery was positively correlated with TBR 2 years later on the medial (p = 0.003) and lateral (p = 0.026) side. Tibial over-hang (positive value) 1 week after surgery on the medial side was found negatively related with KSS score (p = 0.004) and positively related with WOMAC pain score (p = 0.036) 2 years later in multivariate linear regression analysis of PROMS. Both scores were better in the anatomically sized group than in the mild over-hang group (or severe over-hang) (p < 0.001). However, no significant relationship was found between the alignment of TKA components at 1 week after surgery and the end points (TBR and PROMS) 2 years later. CONCLUSION: Under-hang of the tibial component on both the medial and lateral sides can increase the risk of TBR 2 years later. Over-hang of tibial component on the medial side decreases the PROMS (KSS score and WOMAC pain score) 2 years later. An appropriate size of tibial component during TKA is extremely important for patient's prognosis, while the alignment of components might not be as important.

Difference in the early postoperative change of the joint line convergence angle between opening wedge and closed wedge high tibial osteotomies.

BACKGROUND: The purpose of this study was to investigate the correction error associated with soft tissue balance in high tibial osteotomy (HTO) and the difference between opening wedge HTO (OWHTO) and closed wedge HTO (CWHTO). METHODS: A total of 170 knees of 130 patients (85 knees of 68 patients in OWHTO and 85 knees of 62 patients in CWHTO) were evaluated. Anteroposterior radiographs of the knee and full-length leg were taken preoperatively, immediately under general anesthesia postoperatively, 2 days, and 1 and 12 months postoperatively. The femorotibial angle (FTA), joint line convergence angle (JLCA), and medial proximal tibial angle (MPTA) were measured. RESULTS: The postoperative FTA was decreased from 170.5 ± 2.1° at 0 day to 168.6 ± 2.2° at 2 days in OWHTO (P < 0.05), whereas it was not changed from 168.7 ± 2.4° at 0 day to 168.1 ± 2.8° at 2 days in CWHTO. The JLCA was 4.8 ± 1.8° preoperatively, 4.2 ± 1.9° at 0 day, 2.2 ± 1.8° at 2 days (P < 0.05 vs 0 day), 2.6 ± 1.7° at 1 month, and 2.7 ± 1.6° at 12 months in OWHTO, and 7.1 ± 3.2° preoperatively, 4.1 ± 2.4° at 0 day (P < 0.05 vs preoperative), 3.4 ± 2.5° at 2 days, 3.9 ± 2.3° at 1 month, and 4.2 ± 2.6° at 12 months in CWHTO. Multiple regression analysis showed that preoperative factors affecting change of the JLCA from preoperative to postoperative 1 month were the correction angle in OWHTO (P = 0.001) and the preoperative standing JLCA in OWHTO (P < 0.001) and CWHTO (P < 0.001). CONCLUSIONS: A significant decrease of the JLCA occurred immediately after osteotomy under anesthesia in CWHTO, whereas in OWHTO there was no decrease under anesthesia, but it decreased several days postoperatively.

Does new instrument for Oxford unicompartmental knee arthroplasty improve short-term clinical outcome and component alignment? A meta-analysis.

BACKGROUND: The Microplasty (MP) instrumentation designed for the Phase III Oxford mobile-bearing unicompartmental knee arthroplasty (UKA) system is considered a better option to achieve more accurate component positioning and alignment. In the present study, we focused on short-term clinical and radiological outcomes to determine whether the MP instrumentation can reduce the short-term revision rate and occurrence of outliers of metallic components. METHODS: The literature in PubMed, Embase, the Cochrane Library, and Web of Science was searched up to May 2020. Studies were scrutinized by two independent authors, and the revision rate, complication spectrum, and radiological assessment with outlier rates were specifically analyzed. RevMan 5.3 was used for the statistical analysis. RESULTS: Seven studies were included in the meta-analysis. Four studies reported both clinical and radiological outcomes, two reported only radiological outcomes, and one reported only clinical outcomes. The pooled analysis showed that the revision rate in the MP instrumentation group was 0.866 per 100 component years, while that in the control group was 1.124 (odds ratio, 0.77; p < 0.05). The subgroup analysis of the bearing dislocation rate showed a significantly greater reduction in the Korean population than in the populations of other countries (p < 0.05). The radiological assessment showed that the alignment of the femoral component was significantly improved (p < 0.05), while that of the tibial component was not (p > 0.05). CONCLUSION: The newly developed MP instrumentation for Oxford UKA significantly reduced the revision rate of this treatment. The positioning of the femoral component was also proven to be better by radiological assessments.

Cavovarus: Fifth Metatarsal Fractures and Revision Open Reduction Internal Fixation.

Proximal fifth metatarsal fractures, specifically zones 2 and 3, are often treated surgically to lower risk of nonunion and shorten recovery and rehabilitation period. However, even with the advancement of surgical strategies, techniques, and implants, nonunions remain a challenge. One notable risk factor for a primary or recurrent Jones fracture is the cavovarus foot. If this is identified and a recurrent fifth metatarsal base fracture occurs, the surgeon should strongly consider addressing the malalignment in addition to revision open reduction internal fixation. This article provides guidelines for treatment of a recurrent fracture or nonunion with a concomitant cavovarus foot deformity.

Can accuracy of component alignment be improved with Oxford UKA Microplasty® instrumentation?

BACKGROUND: One factor in the long-term survivorship of unicompartmental knee arthroplasty is the accuracy of implantation. In addition to implant designs, the instrumentation has also evolved in the last three decades to improve the reproducibility of implant placement. There have been limited studies comparing mobile bearing unicompartmental knee arthroplasty with contemporary instrumentation and fixed bearing unicompartmental knee arthroplasty with conventional instrumentation. This study aims to determine whether the Microplasty instrumentation in Oxford unicompartmental knee arthroplasty allows the surgeon to implant the components more precisely and accurately. METHODS: A total of 150 patients (194 knees) were included between April 2013 and June 2019. Coronal and sagittal alignment of the tibial and femoral components was measured on postoperative radiographs. Component axial rotational alignment was measured on postoperative computer tomography. The knee rotation angle was the difference between the femoral and tibial axial rotation. A rotational mismatch was defined as a knee rotation angle of > 10°. Statistical analysis was performed using Student t test and Mann-Whitney nonparametric test. A p value < 0.05 was considered statistically significant in each analysis. RESULTS: Between April 2013 to June 2019, 112 patients (150 knees) received Oxford unicompartmental knee arthroplasty, one patient (2 knees) had Journey unicompartmental knee arthroplasty, and 37 patients (42 knees) received Zimmer unicompartmental knee arthroplasty. All femoral components in the Oxford group were implanted within the reference range, compared with 36.6% in the fixed bearing group (p < 0.001). 88.3% of Oxford knees had tibial component falling within the reference range, whereas 56.1% of knees in the fixed bearing group fell within the reference range (p < 0.001). 97.5% of Oxford knees had tibial slope that fell within reference range, whereas 53.7% fell within range for fixed bearing group (p < 0.001). Femorotibial rotational mismatch of more than 10° was noted in 13.8% in Oxford group and 20.5% in fixed bearing group (p = 0.04). CONCLUSION: In conclusion, Microplasty instrumentation for Oxford mobile bearing unicompartmental knee arthroplasty is more accurate and precise compared to conventional fixed bearing unicompartmental knee arthroplasty in sagittal, coronal, and axial alignment. Prospective studies with long-term follow-up are warranted to investigate the clinical implications.

Cervical sagittal alignment in adolescent high dysplastic developmental spondylolisthesis: how does the cervical spine respond to the reduction of spondylolisthesis?

BACKGROUND: Although pelvic and related parameters have been well stated in lumbar developmental spondylolisthesis, cervical sagittal alignment in these patients is poorly studied, especially in high dysplastic developmental spondylolisthesis (HDDS). The purpose of this study is to investigate the sagittal alignment of the cervical spine in HDDS and how the cervical spine responds to reduction of spondylolisthesis. METHODS: Thirty-three adolescent patients with lumbar developmental spondylolisthesis who received preoperative and postoperative whole-spine x-rays were reviewed. They were divided into the HDDS group (n = 24, 13.0 ± 2.2 years old) and the low dysplastic developmental spondylolisthesis (LDDS) group (n = 9, 15.6 ± 1.9 years old). Spinal and pelvic sagittal parameters, including cervical lordosis (CL), were measured and compared between groups. In the HDDS group, the postoperative parameters were measured and compared with those before surgery. RESULTS: HDDS group had a higher proportion of cervical kyphosis (70.8% vs. 22.2%, P = 0.019), and there was a significant difference in CL between the two groups (- 8.5° ± 16.1° vs. 10.5° ± 11.8°, P = 0.003). CL was correlated with the Dubousset's lumbosacral angle (Dub-LSA), pelvic tilt (PT), and thoracic kyphosis (TK). In the HDDS group, CL in patients with a kyphotic cervical spine was significantly improved after reduction of spondylolisthesis (- 16.4° ± 5.9° vs. - 3.6° ± 9.9°, P < 0.001). In the HDDS group, 46% (6/13) of the patients with postoperative Dub-LSA < 90° still had sagittal imbalance (sagittal vertical axis, [SVA] > 5 cm), while no sagittal imbalance was observed in patients with postoperative Dub-LSA > 90° (46% [6/13] vs. 0% [0/11], P = 0.016). CONCLUSIONS: HDDS can lead to cervical kyphosis through a series of compensatory mechanisms. Reduction of spondylolisthesis and correction of lumbosacral kyphosis may correct the cervical kyphosis and normalize the overall spinal sagittal profile. Correction of Dub-LSA to above 90° might be used as an objective to better improve the sagittal alignment of the spine.

[The past, present and future of the control of axial alignment of the lower extremity in high tibial osteotomy].

High tibial osteotomy(HTO) is an effective method for the treatment of knee osteoarthritis by transferring the weight bearing line to the lateral tibial plateau, which can significantly reduce the pressure and cartilage lesion of medial knee compartment.However, under- and over-correction of weight bearing line can lead to early postoperative failure.It is necessary to define the standard of axis correction, make correct preoperative plan, ensure the accuracy of operation and consider the risk factors of under- and over-correction of axis.With the advent of the era of intelligent medicine, the application of patient-specific instrumentation technology based on three dimention printing and navigation technology will help to achieve the precise control of axial alignment in high tibial osteotomy.

[Early clinical effects of total knee arthroplasty with kinematic alignment assisted by patient-specific instrumentation].

Objective: To examine the clinical effects of the treatment of knee osteoarthritis patients with kinematic alignment technique of total knee replacement (KA-TKA) assisted by patient-specific instrumentation (PSI). Methods: The clinical data of 14 patients with knee osteoarthritis treated with unilateral KA-TKA assisted by PSI at Department of Orthopaedic Surgery, Beijing Chaoyang Hospital Affiliated to Capital Medical University from May 2018 to August 2019 were analyzed retrospectively. There were 6 males and 8 females, aged 66.6 years (range: 56 to 79 years), 9 left knees and 5 right knees. The operation time, soft tissue release and extra varus or valgus osteotomy were recorded. The data of osteotomy blocks were measured and compared with the corresponding position of the prostheses. The hip knee ankle angle (HKA), the mechanical distal femoral lateral angle (mLDFA) and the proximal tibial medial angle (MPTA) were measured before and 3 months after the operation. The knee joint functional score (KS-F) , knee joint clinical score (KS-C) and the Western Ontario McMaster (WOMAC) Osteoarthritis Index were recorded and compared by paired t test or Wilcoxon non-parametric test. Results: The operation time was (81.8±16.9) minutes (range: 60 to 115 minutes), 2 cases were manually increased varus osteotomy by 2 mm and 1 patient received lateral retinaculum release. There was no extra medial or lateral soft tissue release. Intraoperative measurement of the resection showed that the femoral side mismatch was within 2 mm. The medial and lateral condyle, the medial and lateral posterior condyles were relatively overcut by 0.50 mm, 0.21 mm, 0.93 mm, and 0.71 mm, respectively. The tibial side mismatch was within 1.5 mm, the medial and lateral plateau were relatively undercut by 0.43 mm and 0.32 mm. HKA was corrected from (8.8±5.6) ° to (1.6±4.3) ° (t=20.723, P=0.000) .KS-C improved from 28.21±13.47 preoperative to 78.07±8.01 postoperative (t=-16.570, P=0.000); KS-F improved from 41.00±15.25 preoperative to 84.93±10.85 postoperative (t=-14.675, P=0.000).WOMAC Osteoarthritis Index decreased from 53.5 (25.75) (M(Q(R))) preoperative to 5.5 (5.25) postoperative (Z=-3.297, P=0.001) .No statistically significant difference was found in mLDFA and MPTA before and after surgery. No significant patellofemoral complication was recorded during follow-up time. Conclusions: PSI assisted TKA resection has high accuracy. KA-TKA aims to restore the native anatomy of the knee joint, only corrects the malalignment of lower extremities caused by articular cartilage wear, with less interference to soft tissues, easy to obtain satisfactory knee joint laxity and has a promising early clinical effect.

Revision of Malaligned Lapidus and Nonunited Lapidus.

"Lapidus arthrodesis is becoming more of a common procedure for treatment of hallux valgus deformities. Like other procedures, complications are possible. The common complications associated with Lapidus arthrodesis procedures include nonunion and malunion. Malunion is typically broken down into recurrence, elevated first ray, shortened first ray, or plantarflexed first ray. This article discusses these common complications after Lapidus arthrodesis.

Correction of Genu Valgum in Patients With Congenital Fibular Deficiency.

BACKGROUND: Patients with congenital fibular deficiency often develop genu valgum secondary to lateral femoral condylar hypoplasia. Guided growth strategies are often performed to correct limb alignment when adequate skeletal growth remains. METHODS: A retrospective review of patients with postaxial hypoplasia of the lower extremity managed with an amputation strategy and who had a guided growth procedure for coronal plane limb malalignment during their course of treatment was performed. Clinical and radiographic data, including measures of coronal plane deformity and alignment, type of amputation, subsequent operative procedures, and complications were recorded. RESULTS: Seventeen patients (20 extremities) met study inclusion criteria (mean follow-up 8.8 y). Foot ablation and hemiepiphysiodesis for valgus deformity of the knee was performed in all extremities. The average age at the time of initial hemiepiphysiodesis was 11.2 years at an average of 8.8 years from the initial amputation procedure. The mean preoperative mechanical axis deviation was 26.5 mm, which was corrected to a mean mechanical axis deviation of 7.0 mm. Fifteen (75%) of the extremities had correction of the deformity to neutral alignment after the initial procedure. Lack of correction occurred in 3 extremities, and overcorrection occurred in 2 extremities. Additional procedures were required in 5 extremities for rebound valgus deformity after hardware removal. CONCLUSIONS: In patients with postaxial hypoplasia, regular monitoring of the residual limb for growth-related changes must occur to ensure optimal function and prosthetic fit. Timing of the guided growth procedure is critical, as younger patients may be more likely to experience rebound deformity. Families and patients should be made aware that growth might be unpredictable in this population with risks of both overcorrection and undercorrection. LEVEL OF EVIDENCE: Level IV-case series.

Congenital Pseudarthrosis of the Fibula: Controlling Ankle Valgus in a Heterogenous Condition.

BACKGROUND: Congenital pseudarthrosis of the fibula (CPF) is a rare disorder characterized by a deficiency in the continuity of the fibula and can lead to progressive ankle valgus malalignment. An existing classification system for CPF is imperfect and may contribute to heterogeneity in reporting and discrepancy of outcomes in the literature. METHODS: Fifteen patients with CPF treated at our institution between 1995 and 2017 were retrospectively identified. Only patients with dysplasia leading to spontaneous fracture or pseudarthrosis were included in this series. The median age at presentation was 2.5 years (range: 3 mo to 13.4 y). The median duration of follow-up from the initial presentation was 11.8 years (range: 2.0 to 24 y). Chart review and serial radiographs were analyzed to assess natural history and outcomes following surgery. RESULTS: The coexistence of tibial dysplasia in CPF is very common. Patients were classified into 3 groups based on the degree of tibial involvement-group 1: no evidence of tibial dysplasia, group 2: mild tibial dysplasia, and group 3: significant tibial dysplasia. Age at presentation and age at which fibular fracture occurred were progressively younger with a greater degree of tibial involvement (P<0.05). In the absence of surgical intervention, group 1 patients did not undergo progressive ankle valgus (defined as the valgus change in tibiotalar angle by ≥4 degrees), whereas all patients in groups 2 and 3 did (P<0.001). Fibular osteosynthesis was performed in 6 patients, with union seen only in group 1 patients. Ten patients underwent distal tibiofibular fusion, with no cases of nonunion seen. Distal tibiofibular fusion with or without medial distal tibial hemiepiphysiodesis halted the progression of ankle valgus in 8 of the 10 patients. Further progression of ankle valgus occurred only in patients who did not undergo concurrent medial distal tibial hemiepiphysiodesis and with considerable wedging of the distal tibial epiphysis at the time of fusion. CONCLUSIONS: Tibial dysplasia and CPF are intimately related. Grouping patients on this basis may help guide natural history and treatment and may explain discrepancies in findings in the literature. Fibular osteosynthesis, distal tibiofibular fusion, and medial distal tibial hemiepiphysiodesis may all have an important role in the treatment of CPF. LEVEL OF EVIDENCE: Level IV-case series.

High thoracic kyphosis: impact on total thoracic kyphosis and cervical alignment in patients with adolescent idiopathic scoliosis.

PURPOSE: To evaluate the impact of proximal thoracic segment (T1-T5) on global thoracic kyphosis, as well as its influence on cervical alignment (lordotic, kyphotic or straight) in patients with adolescent idiopathic scoliosis (AIS). METHODS: We conducted a retrospective study of 80 patients with AIS. The inclusion criteria were patients between 10 and 18 years of age with a posteroanterior (PA) and lateral full-length radiographs, excluding those subjected to surgery, orthotic treatment, with other spinal disease or with poor X-ray quality. The parameters evaluated were age, sex, pelvic incidence (PI), sacral slop (SS), pelvic tilt (PT), global sagittal balance (GSB), scoliotic curvatures (differentiated according to primary curve, lumbar modifier and sagittal modifier), cervical spine alignment, thoracic sagittal Cobb angle between T1 and T5, T5 and T12 and between T1 and T12. RESULTS: In patients with AIS, the proximal sagittal thoracic Cobb segment, contrary to the distal, demonstrated a significant positive correlation with cervical spine alignment (p < 0.05). As there is an increase in proximal thoracic angle, there is an increase in cervical lordosis. We also demonstrated that the correlation between an increase in scoliotic curvature and a decrease in kyphosis only occurred in the distal thoracic segment (T5-T12). Relative to the spinopelvic parameters, the PI was not related with the dorsal kyphosis or shape of the cervical spine. CONCLUSIONS: In AIS, proximal (T1-T5) and distal (T5-T12) thoracic kyphosis have different contributions on the global thoracic sagittal curvature and in the phenomenon of hypokyphosis. On the other hand, only the proximal segment is significantly related to the shape of the cervical spine. LEVEL OF EVIDENCE: IV.

Postoperative sagittal alignment of congenital thoracolumbar to lumbar kyphosis or kyphoscoliosis: a minimum 10-year follow-up study.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To elucidate the postoperative course of sagittal alignment in patients with congenital thoracolumbar to lumbar kyphosis or kyphoscoliosis. Acquisition of acceptable sagittal alignment is essential to treat spinal deformity. Little evidence exists regarding long-term surgical outcomes on sagittal alignment in congenital kyphosis or kyphoscoliosis. METHODS: Sixteen consecutive patients (mean age 10.5 ± 3.5 years) with congenital kyphosis or kyphoscoliosis who underwent vertebra resection and osteotomy with instrumentation by single posterior or combined anterior and posterior approach were included. Preoperative radiographs identified kyphosis in 3 patients and kyphoscoliosis in 13 patients. All patients had clinical and radiologic follow-up for > 10 years (mean 16.3 ± 4.0 years). RESULTS: Segmental kyphosis was significantly improved from 33.9° ± 20.1° to 14.9° ± 17.6° by surgery and was finally maintained at 16.8° ± 22.2° and sagittal vertical axis (SVA) of 13.1 ± 33.7 mm at preoperation and 18.3 ± 22.1 mm at postoperation significantly increased to 26.8 ± 45.7 mm during follow-up. Of the 16 patients, 5 (31%) were identified as those with SVA > 40 mm, and SVA increases > 30 mm during follow-up. In patients with sagittal malalignment, radiographs demonstrated decreased lumbar lordosis at the lower foundation from 28.8° ± 39.0° to 17.0° ± 17.6°, significant increased pelvic tilt from 25.8° ± 5.4° to 37.4° ± 7.4° during follow-up (p < 0.05), and larger residual segmental kyphosis than those in the 11 patients without sagittal malalignment with statistical significance. Of the five cases, progression of local kyphosis (one case) and sagittal decompensation, including decreased lumbar lordosis with disc degeneration (four cases), increased pelvic tilt (three cases), or proximal junctional kyphosis (two cases), were observed. CONCLUSION: Based on this > 10-year follow-up study, residual kyphosis and sagittal decompensation are revealed to be risk factors for postoperative sagittal malalignment in patients with congenital thoracolumbar to lumbar kyphosis or kyphoscoliosis. LEVEL OF EVIDENCE: Level IV, case series.

Do spacer blocks accurately estimate deformity correction and gap balance in total knee arthroplasty? A prospective study with computer navigation.

BACKGROUND: Spacer blocks are used commonly in knee arthroplasty to estimate gaps and ligament balance. Their use continues along with modern technology despite dearth of literature regarding their accuracy and reliability. This prospective study aims to determine the difference in values of gap and balance measurements between spacers and trials in computer assisted TKA. METHODS: 50 patients with moderate varus deformity of <20° undergoing primary TKA were recruited for this prospective study. After navigation assisted cuts and requisite ligament release, gaps and balance were recorded in extension and 90° flexion with spacer block followed by implant trials. RESULTS: There were 33 females and 17 males with average BMI of 28.2 ±â€¯5kg/m2. The average preoperative flexion deformity was 6.5°â€¯±â€¯4.4° and varus deformity was 8.2°â€¯±â€¯3.8°. Average difference of deformity in sagittal plane in extension between spacer and trial was 6.2° which was statistically significant (p = 0.001) implying that knee achieves more extension with spacer blocks as compared to trials because the blocks do not have posterior offset of the condyles. However, there was no difference between values of soft tissue balance and coronal plane correction between spacer blocks and trials in extension and 90° flexion (p > 0.05). CONCLUSION: Spacer blocks do not estimate extension space accurately with knee achieving 6.2 more flexion with trials as compared to spacer blocks when assessed for sagittal plane correction in extension. Spacer blocks should pass in easily in extension to avoid any flexion deformity when the actual trials are inserted.

Preliminary experience with an image-free handheld robot for total knee arthroplasty: 77 cases compared with a matched control group.

BACKGROUND: Achieving an optimal limb alignment is an important factor affecting the long-term survival of total knee arthroplasty (TKA). This is the first study to look at the limb alignment and orientation of components in TKA using a novel image-free handheld robotic sculpting system. METHODS: This case-controlled study retrospectively compared limb and component alignment of 77 TKAs performed with a robot (Robot-group) with a matched control group of patients who received conventional alignment with intramedular rods (Control group). Alignment and component positioning was measured on full-leg weight-bearing and standard lateral X-rays by two independent observers. The image-free handheld robotic sculpting system calculated the planned and achieved mechanical axis (MA). Outliers were defined as > 3° deviation from planned alignment. RESULTS: Mean MA was 180.1° (SD = 1.9) in the Robot-group, compared to the Control group with a mean MA of 179.1° (SD = 3.1, p = 0.028). We observed 5 outliers (6%) in the Robot-group and 14 outliers (18%, p = 0.051) in the Control group. Fraction of outliers of the frontal tibial component was 0% in the Robot-group versus 8% in the Control group (p = 0.038). There were no other statistical differences regarding the implant positioning between both groups. CONCLUSION: The Robot-group showed significantly less outliers compared to the conventional technique. Whether these differences are clinically relevant is questionable and should be investigated on the long term. Randomized controlled trials with larger patient series will be needed in the future to confirm our preliminary results.

Prevalence of Rotational Malalignment After Intramedullary Nailing of Tibial Shaft Fractures: Can We Reliably Use the Contralateral Uninjured Side as the Reference Standard?

BACKGROUND: Intramedullary (IM) nailing is the treatment of choice for most tibial shaft fractures. However, an iatrogenic pitfall may be rotational malalignment. The aims of this retrospective analysis were to determine (1) the prevalence of rotational malalignment using postoperative computed tomography (CT) as the reference standard; (2) the average baseline tibial torsion of uninjured limbs; and (3) based on that normal torsion, whether the contralateral, uninjured limb can be reliably used as the reference standard. METHODS: The study included 154 patients (71% male and 29% female) with a median age of 37 years. All patients were treated for a unilateral tibial shaft fracture with an IM nail and underwent low-dose bilateral postoperative CT to assess rotational malalignment. RESULTS: More than one-third of the patients (n = 55; 36%) had postoperative rotational malalignment of ≥10°. Right-sided tibial shaft fractures were significantly more likely to display external rotational malalignment whereas left-sided fractures were predisposed to internal rotational malalignment. The uninjured right tibiae were an average of 4° more externally rotated than the left (mean rotation and standard deviation, 41.1° ± 8.0° [right] versus 37.0° ± 8.2° [left]; p < 0.01). Applying this 4° correction to our cohort not only reduced the prevalence of rotational malalignment (n = 45; 29%), it also equalized the distribution of internal and external rotational malalignment between the left and right tibiae. CONCLUSIONS: This study confirms a high prevalence of rotational malalignment following IM nailing of tibial shaft fractures (36%). There was a preexisting 4° left-right difference in tibial torsion, which sheds a different light on previous studies and current clinical practice and could have important implications for the diagnosis and management of tibial rotational malalignment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.