Realignment Procedures Research Articles

Microfracture for medium size to large knee chondral defects has limited long-term efficacy: A systematic review.

To evaluate clinical and radiographic outcomes, return to sport, failure rate, operations and complications in patients undergoing microfracture of the knee, including the femoral condyle, tibial plateau, patella and trochlea, at a mean 10-year or greater follow-up. A literature search was performed by querying SCOPUS, PubMed, Medline and the Cochrane Central Register for Controlled Trials from database inception through May 2023 according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Inclusion criteria were level I-IV human studies reporting on outcomes, reoperations and complications following microfracture of the knee at a mean 10-year or greater follow-up. Biomechanical and epidemiological studies, including patients undergoing concomitant realignment procedures, and studies with patients under 18 years old were excluded. Data regarding failure, as defined by each study, as well as reoperations were gathered. Study quality was assessed via the Methodological Index for Nonrandomized Studies criteria. Nine studies from 2003 to 2018, consisting of 727 patients (mean age 38.9 ± 8.1 years; range 25.8-47.6) undergoing microfracture for chondral defects in the knee were identified. Mean follow-up ranged from 10 to 17 years. Males composed 56.5% of patients, with a mean defect size ranging from 2.3 to 4.01 cm2. Based on radiographs at follow-up, osteoarthritis progression occurred in 40%-48% of patients. Magnetic Resonance Observation of Cartilage Repair Tissue scores were low. Patient-reported outcome measures showed significant improvement in postoperative scores at final follow-up. Return-to-sport rate ranged from 17.2% to 20%. Longitudinal analysis revealed declining clinical outcomes and return-to-sport rates from short- and mid- to long-term follow-up. There was high variability in failure definition and reoperations, with 2.9%-41% of patients requiring total knee arthroplasty. At a mean 10-year or greater follow-up, microfracture for chondral defects of the knee 2-4 cm2 in size demonstrated a high rate of osteoarthritis progression with poor healing of the chondral defect and low overall return-to-sport rates. Failure and reoperation rates ranged from 2.9% to 41%, with declining outcomes from short- and mid- to long-term follow-up. The advantages of microfracture relating to availability, complexity, and cost should be weighed against concerns about long-term success, particularly with medium-size and larger lesions. Level IV systematic review.

Management of patellar and trochlear cartilage lesions with matrix-induced autologous chondrocyte implantation in conjunction with patellofemoral realignment procedures improves patient-reported outcomes and magnetic resonance image appearance

ObjectivesThe aim of this study is to evaluate the relationship between the achievement of clinically significant improvement in patient-reported outcome measures (PROMs) and the postoperative magnetic resonance image (MRI) appearance of matrix-associated chondrocyte implantation (MACI), in conjunction with patellofemoral realignment procedures, for the treatment of grade-IV chondral defects about the patellofemoral joint. MethodsA retrospective review of patients undergoing MACI for grade-IV chondral defects of the patella or trochlea by a single sports-medicine-fellowship-trained surgeon from 2017 to 2020 was performed. Concomitant realignment procedures, including tibial tubercle osteotomy and medial patellofemoral ligament reconstruction, were also performed as needed. Patients with preoperative and minimum 1-year postoperative PROMs and postoperative knee MRI were included. MRI scans were obtained at 6.3 (interquartile range: 5.8, 7.5) months postoperatively. A fellowship-trained musculoskeletal radiologist assigned a Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score (range: 0–100, with 100 equating to complete graft healing) to each MRI. Achievement of the minimal clinically important difference (MCID) for International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Score—Quality of Life, and Kujala scores were determined for each patient. Paired t-tests or Wilcoxon rank-sum tests were used to evaluate for an association between achievement of the MCID for each PROM and MOCART score. The average follow-up time and time from surgery to PROMs were 2.7 ​± ​1.5 years and 1.7 ​± ​0.66 years, respectively. ResultsThirty patients were included. There was a significant improvement in all PROMs from preoperative to postoperative (p ​< ​0.001). More than two-thirds of patients achieved the MCID for each PROM. Patients who achieved the MCID for IKDC had significantly higher MOCART scores (66.5 ​± ​16.2) than those who did not meet the MCID for IKDC (50.6 ​± ​23.6, p ​= ​0.043). ConclusionMACI for the treatment of patellofemoral chondral injuries is associated with clinically significant improvement in PROMs at short-term follow-up. Clinically significant improvements in IKDC scores are associated with a more mature MRI appearance of the autologous chondrocyte implantation graft on postoperative MRI, as indicated by higher MOCART scores. Level of evidenceIV—Case Series.

Joint Preservation Surgery Using Supramalleolar Osteotomy Combined with Posterior Tibial Tendon Release and Lateral Ligament Augmentation in Advanced Varus Ankle Arthritis.

Background: Recent studies utilizing weight-bearing computed tomography have identified abnormal internal rotation of the talus in advanced varus ankle arthritis (VAA) with a large talar tilt (TT), influenced by the posterior tibial tendon (PTT). This study aimed to evaluate the clinical and radiographic results of supramalleolar osteotomy (SMO) combined with PTT release and lateral ligament augmentation for VAA with a large TT. Methods: From January 2015 to September 2018, 15 patients with VAA and a large TT (greater than 5°) underwent SMO combined with PTT release. Clinical results, including visual analog scale (VAS) for pain, American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, and ankle osteoarthritis scale (AOS), were assessed. Radiographic results were assessed with various parameters, including medial distal tibial angle (MDTA), anterior distal tibial angle (ADTA), talar tilt (TT), talus center migration (TCM), Meary angle, hindfoot alignment angle (HAA), and hindfoot moment arm (HMA) on foot and ankle weight-bearing radiographs. Clinical and radiographic results were evaluated preoperatively and at the last follow-up. Results: VAS, AOFAS ankle-hindfoot score, and AOS improved significantly from 7.5, 54.4, and 72.6 preoperatively to 3.1, 82.5, and 34.5 postoperatively, respectively. All radiographic parameters exhibited significant changes postoperatively, with the exception of the Meary angle, which demonstrated no significant change. Four patients exhibited improvement in radiographic stage postoperatively; however, average radiographic stage did not significantly improve postoperatively in all patients. One patient progressed to end-stage arthritis postoperatively, necessitating additional ankle arthrodesis. Conclusions: In conclusion, lengthening and lateral ligament augmentation combined with bony realignment procedures may be a reasonable option for treating VAA with a large TT greater that 5°.

Isolated Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Regardless of Tibial Tubercle–Trochlear Groove Distance and Patellar Height: Minimum 5-Year Outcomes

Background: It remains unclear which subset of patients with recurrent patellofemoral instability would benefit from a concomitant bony realignment procedure in addition to a medial patellofemoral ligament (MPFL) reconstruction. Purpose: To provide midterm results for patients who underwent an isolated MPFL reconstruction as part of an ongoing prospective trial. Study Design: Case series; Level of evidence, 4. Methods: Patients with recurrent patellar instability were prospectively enrolled in an institutional registry beginning in March 2014. Exclusion criteria included history of a previous surgery for patellar instability, an off-loadable (inferior/lateral) chondral defect, anterior knee pain ≥50% of their chief complaint, and a “jumping J” sign. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of their bony anatomic characteristics. Patient-reported outcome measures (PROMs), episodes of recurrent instability, and ability to return to sport were obtained annually. Radiographic measurements of baseline radiographs and MRI were obtained at baseline. Results: A total of 138 patients underwent isolated MPFL reconstruction between March 2014 and December 2019. The mean radiographic measurements were tibial tubercle–trochlear groove, 15.1 ± 4.9 mm; Caton-Deschamps index, 1.14 ± 0.16; patellar trochlear index, 46.9% ± 15.1%; trochlear depth index, 2.5 ± 1.2 mm; tibial tubercle to lateral trochlear ridge, −8.4 ± 5.7 mm; and patellar tendon to lateral trochlear ridge, 5.7 ± 6.2 mm. Trochlear dysplasia, defined as a trochlear depth index <3 mm, was present in 79/125 (63%) patients. A total of 50 patients reached ≥5 years, of whom 40 (80%) completed follow-up PROMs. A total of 119 patients reached ≥2 years, of whom 89 (75%) completed follow-up PROMs. Six patients (5%) reported recurrent instability with a mean time of 2.97 years after surgery. All PROMs improved over time except for the Pediatric Functional Activity Brief Scale (Pedi-FABS), which had no change. At 2 years, the mean changes from baseline for Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life subscale (QOL), Pedi-FABS, International Knee Documentation Committee (IKDC) score, KOOS Physical Function Short Form (PS), and Kujala score were 42.1, 0.6, 35.1, –23.5, and 32.3, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .999. At 5 years, the mean changes from baseline for KOOS-QOL, Pedi-FABS, IKDC, KOOS-PS, and Kujala score were 42.6, –2.8, 32.6, –21.5, and 31.6, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .453. In total, 89% of patients returned to sport with a mean of 9.1 months. Conclusion: Midterm outcomes for patients who underwent isolated MPFL reconstruction were favorable and were maintained at 5 years. Outcomes for the expanded cohort of patients with a minimum 2-year follow-up support previously published results.

Poster 289: Impact of Graft Selection on Clinical Outcomes following Isolated MPFL Reconstruction in Adolescent and Young Adult Athletes

Objectives: Patellofemoral instability (PFI) commonly requires surgical intervention in adolescent and young adult athletes. However, the clinical impact of graft selection, which may vary amongst surgeons, has not been well studied. The purpose of this study was therefore to compare clinical outcomes, including recurrent instability reoperations and complications, of medial patellofemoral ligament reconstruction (MPFLR), based on graft type. Methods: Electronic medical records of patients who underwent primary MPFLR surgery for PFI over a 10-year period between 2010 and 2019 at a single center were retrospectively reviewed. Collected data included demographic, clinical, and radiologic parameters of instability and post-operative clinical outcomes. Exclusion criteria included concomitant extensor realignment procedures (tibial tubercle osteotomy, patellar tendon transfer procedures) and factors that would alter routine surgical indications or technical approaches, such as fixed or syndromic PFI, osteochondral shear fractures undergoing fixation or &gt;1 cm in diameter, and prior ipsilateral knee surgery. Results: One-hundred and one patients (average age 15.2 years, 63% female), underwent primary isolated MPFLR with an average follow up time of 2.87 years. There were no significant differences in demographic and radiographic parameters between autograft and allograft, other than more semitendinosus grafts, increased number of pre-op dislocation events, and higher sulcus angle in autograft (Table 1). The autograft group had a higher rate of recurrent instability (41% vs 14%, p = 0.01) but no significant difference in return to sport, complications, and reoperations (Table 2). Reoperations for recurrent instability were performed in 9% of all patients (Table 3). Subgroup analysis of allograft tendon type demonstrated more dislocations and recurrent instability in gracilis than semitendinosus, though these differences were not statistically significant, and there was no difference in recurrent instability surgery or complications (Table 4). Conclusions: In adolescent and young adult athletes undergoing isolated primary MPFLR for PFI, allograft may be associated with decreased rates of recurrent instability compared to autograft. While trends towards higher recurrent instability were detected with gracilis allograft, compared to semitendinosus allograft, the precise role of allograft tendon type would benefit from future studies with larger sample size to better elucidate its impact on clinical outcomes.

Contemporary utilization of three-column osteotomy techniques in a prospective complex spinal deformity multicenter database: implications on full-body alignment and perioperative course.

Research has focused on the increased correction from a three-column osteotomy (3CO) during adult spinal deformity (ASD) surgery. However, an in-depth analysis on the performance of a 3CO in a cohort of complex spinal deformity cases has not been described. This is a retrospective study on a prospectively enrolled, complex ASD database. This study aimed to determine if three-column osteotomies demonstrate superior benefit in correction of complex sagittal deformity at the cost of increased perioperative complications. Surgical complex adult spinal deformity patients were included and grouped into thoracolumbar 3COs compared to those who did not have a 3CO (No 3CO) (remaining cohort). Rigid deformity was defined as ΔLL less than 33% from standing to supine. Severe deformity was defined as global (SVA > 70mm) or C7-PL > 70mm, or lumbopelvic (PI-LL > 30°). Means comparison tests assessed correction by 3CO grade/location. Multivariate analysis controlling for baseline deformity evaluated outcomes up to six weeks compared to No 3CO. 648 patients were included (Mean age 61 ± 14.6years, BMI 27.55 ± 5.8kg/m2, levels fused: 12.6 ± 3.8). 126 underwent 3CO, a 20% higher usage than historical cohorts. 3COs were older, frail, and more likely to undergo revision (OR 5.2, 95% CI [2.6-10.6]; p < .001). 3COs were more likely to present with both severe global/lumbopelvic deformity (OR 4), 62.4% being rigid. 3COs had greater use of secondary rods (OR 4st) and incurred 4 times greater risk for: massive blood loss (> 3500mL), longer LOS, SICU admission, perioperative wound and spine-related complications, and neurologic complications when performed below L3. 3COs had similar HRQL benefit, but higher perioperative opioid use. Mean segmental correction increased by grade (G3-21; G4-24; G5-27) and was 4 × greater than low-grade osteotomies, especially below L3 (OR 12). 3COs achieved 2 × greater spinopelvic correction. Higher grades properly distributed lordosis 50% of the time except L5. Pelvic compensation and non-response were relieved more often with increasing grade, with greater correction in all lower extremity parameters (p < .01). Due to the increased rate of complications, 3COs trended toward higher perioperative cost ($42,806 vs. $40,046, p = .086). Three-column osteotomy usage in contemporary complex spinal deformities is generally limited to more disabled individuals undergoing the most severe sagittal and coronal realignment procedures. While there is an increased perioperative cost and prolongation of length of stay with usage, these techniques represent the most powerful realignment techniques available with a dramatic impact on normalization at operative levels and reciprocal changes.

Three-Dimensional Imaging of the Patellofemoral Joint Improves Understanding of Trochlear Anatomy and Pathology and Planning of Realignment

Three-dimensional (3D) modeling using digital or printed models provides a unique perspective that caters to cognitive spatial ability in a way that can add to our understanding and mental representations of human anatomy. This is particularly useful in the setting of trochlear dysplasia, where the morphology of the groove can exhibit substantial variability and complexity. Using 3D reformatted images and models, a pragmatic understanding of how morphology influences patellofemoral pathology can be gleaned. Further, this perspective facilitates cognition of what patellar tracking may look like after realignment procedures. Using 3D modeling, concepts such as patella alta, trochlear depth, lateralization of the patellar entry point, trochlear curvature, and the presence of a proximal trochlear spur can help afford a better understanding of how trochlear anatomy may influence tracking while also providing insight as to the ideal tracking path. The use of 3D has recently emerged as a useful tool in multiple surgical subspecialties, particularly in situations involving surgical planning or complex anatomy. Given the complexity and variation in trochlear morphology in patients with trochlear dysplasia who develop either patellar instability or focal overloading, 3D modeling is well-suited to provide a perspective that can add to our understanding of trochlear dysplasia, and potentially even how we diagnose and treat it. Level of EvidenceLevel V, expert opinion.

Improvement in Clinical and Radiographic Outcomes After Isolated Realignment Surgery in Patients With Large Cystic Osteochondral Lesion of the Talar Shoulder and Concurrent Malalignment.

Malalignment has been suggested as a predisposing factor for the development of osteochondral lesions of the talus (OLTs). To evaluate the clinical and radiographic outcomes of realignment surgery in patients with a large cystic OLT of the talar shoulder and concurrent malalignment of the foot and ankle. Case series; Level of evidence, 4. The authors reviewed consecutive patients with large cystic OLTs (diameter, >10 mm) of the talar shoulder and concurrent malalignment of the foot and ankle who underwent realignment surgery between September 2013 and April 2021. The type of realignment procedure was determined based on patient symptoms and findings on plain radiographs and weightbearing computed tomography. Clinical improvement was assessed using pre- and postoperative Foot Function Index (FFI) scores and the visual analog scale (VAS) for pain. The OLT location was categorized according to Raikin zone, and the OLT area and volume were measured and compared pre- and postoperatively. The comparative analysis was performed using the Wilcoxon signed-rank test. In total, 27 ankles in 27 patients (mean age, 34.4 ± 11.9 years) were included in the analysis. There were 25 patients with a medial lesion (zone 4 [n = 19], zone 7 [n = 5], and zone 1 [n = 1]), and 2 patients with a lateral lesion (zone 6). Despite OLT location, patients' symptoms varied; 15 (55.6%) patients reported both medial- and lateral-sided pain, 10 (37%) reported lateral-sided pain, and 2 (7%) reported medial-sided pain. Supramalleolar osteotomy was performed in 18 patients, while foot and hindfoot correction without supramalleolar osteotomy was performed in 9 patients. Postoperatively, both the median FFI (from 44.4 [interquartile range (IQR), 35.7-52.2] to 9.1 [IQR, 5.2-13.9]) and median VAS pain score (from 6 [IQR, 5-6] to 1 [IQR, 1-2]) improved significantly (P < .0001 for both), and the median lesion size (from 25.8 mm2 [IQR, 19.3-45.2 mm2] to 13.8 mm2 [IQR, 6.8-26.5 mm2]) and median volume (from 2226.8 mm3 [IQR, 1311-3104 mm3] to 1326.5 mm3 [IQR, 714-2100 mm3]) decreased significantly (P < .0001 for both). During the mean follow-up of 4.1 ± 2.1 years, no subsequent surgery for OLT was necessary. The results suggest that realignment procedures can improve the symptoms and radiographic profile of OLTs in patients with large cystic OLTs of the talar shoulder and malalignment of the foot and ankle.

Peroneal tendon injuries

The peroneal tendons work to both evert the foot and stabilize the hindfoot on plantarflexion and push off. The tendons are frequently injured as part of sprains and soft tissue injuries to the ankle joint, but diagnosis and treatment are often delayed. Athletes participating in activities with repetitive ankle motion, particularly those involving cutting and twisting movements, as well as those with certain anatomical features, are prone to peroneal tendon injury. Often synovitis and low-grade tendinopathy of the peroneal tendons can be managed with physiotherapy and bracing. Large longitudinal tears, rupture, and subluxation or dislocation of the tendons from the retromalleolar groove are more likely to be treated operatively, although pre-surgical rehabilitation will still be useful in chronic cases. Other surgical procedures can be combined as part of an effective treatment plan such as ankle arthroscopy, ligament stabilization and realignment procedures such as a lateralizing calcaneal osteotomy and Barouk–Rippstein–Toullec first metatarsal elevation osteotomy for non-neurogenic cavus. Persistent weakness in the peroneal tendons post injury may contribute to worsening hindfoot varus deformity: in turn, this leads to further stress on peroneus brevis which can lead to its rupture and consequently further deformity if untreated.

A MEDIUM-TERM REVIEW OF THE OUTCOMES OF TALAR OSTEOCHONDRAL LESIONS TREATED WITH MATRIX-ASSOCIATED STEM CELL TRANSPLANTATION

IntroductionOsteochondral lesions (OCLs) of the talus are a challenging and increasingly recognized problem in chronic ankle pain. Many novel techniques exist to attempt to treat this challenging entity. Difficulties associated with treating OCLs include lesion location, size, chronicity, and problems associated with potential graft harvest sites. Matrix associated stem cell transplantation (MAST) is one such treatment described for larger lesions &gt;15mm2 or failed alternative therapies. This cohort study describes a medium-term review of the outcomes of talar lesions treated with MAST.MethodsA review of all patients treated with MAST by a single surgeon was conducted. Preoperative radiographs, MRIs and FAOS outcome questionnaire scores were conducted. Intraoperative classification was undertaken to correlate with imaging. Postoperative outcomes included FAOS scores, return to sport, revision surgery/failure of treatment and progression to arthritis/fusion surgery.Results58 MAST procedures in 57 patients were identified in this cohort. The mean follow up was 5 years. There were 20 females and37males, with a mean age of 37 years (SD 9.1). 22 patients had lateral OCLS were and 35 patients had medial OCLs. Of this cohort 32patients had previous surgery and 25 had this procedure as a primary event. 15 patients had one failed previous surgery, 9 patients had two, four patients had three previous surgeries and three patients had four previous surgeries. 12 patients had corrective or realignment procedures at the time of surgery. In terms of complications 3 patients of this cohort went on to have an ankle fusion and two of these had medial malleolar metal work taken out prior to this, 5 patients had additional procedures for arthrofibrotic debridements, 1 patient had a repeat MAST procedure, 1 additional patients had removal of medial malleolar osteotomy screws for pain at the osteotomy site, there were 2 wound complications one related to the ankle and one related to pain at the iliac crest donor site.ConclusionMAST has demonstrated positive results in lesions which prove challenging to treat, even in a “ failed microfracture” cohort.RCT still lacking in field of orthobiologics for MAST. Longer term follow up required to evaluate durability.

Spontaneous Radiographic Improvement of a Large Cystic Osteochondral Lesion of the Talar Shoulder Following Realignment Surgery for Symptomatic Improvement

Category: Sports; Ankle Introduction/Purpose: Treating patients with a large cystic osteochondral lesion of the talar shoulder and concurrent radiographic evidence of foot and ankle malalignment is a clinical challenge. Differentiating the origin of pain in such a situation is not always straightforward, and surgical treatment for both conditions at the same time can complicate the surgery. It has been suggested that unaddressed malalignment can lead to an unfavorable result after osteochondral lesion of the talus (OLT) surgery, but the isolated effect of realignment surgery on OLT patients has not been elucidated. Therefore, the purpose of this study was to evaluate the outcomes of realignment surgery for symptomatic relief in patients with a large cystic OLT of the talar shoulder with concurrent malalignment of the foot and ankle. Methods: This retrospective study reviewed 27 patients (mean age: 34.4 years) with large cystic OLTs (&gt;10mm in diameter) of the talar shoulder who underwent realignment surgery. Patients were excluded if they had plain radiographs suggestive of degenerative ankle arthritis, or less than 2 years of follow-up. Patients' symptoms prior to surgery were categorized by location and character. The types of realignment procedure were determined by a senior surgeon based on the patients' symptoms and radiographic findings from plain x-rays and weightbearing computed tomography. None of the included patients underwent any type of cartilage repair or replacement procedures during the realignment surgery. Clinical improvement was assessed using the foot function index (FFI) and visual analogue scale (VAS). The location of the OLTs was categorized into 9-Raikin zones, and the size of the OLTs was measured and compared pre- and postoperatively using previously described methods. Results: There were 25 patients with a medial lesion (zone 4 [n=19]; zone 7 [n=5]; zone 1 [n=1]) and two with a lateral lesion (zone 6). Despite the location of the OLT, patients' symptoms varied, with 13 experiencing diffuse medial and lateral pain, 13 experiencing lateral pain, and 1 experiencing anteromedial pain as their primary location of pain. Supramalleolar osteotomy (SMO) was performed in 18 patients (medial open-wedge [n=17] and dome-type [n=1]), while hindfoot correction without SMO was done in 9 patients. Postoperatively, both the FFI and VAS scores significantly improved. The mean preoperative size of cystic lesion was 32.9mm3 (range, 12.6-79.6), and there was a significant decrease in size to 16.3mm3 (range, 0-40.1) postoperatively. During the follow-up period, no subsequent surgery for OLT was necessary. Conclusion: We found that the main location of pain does not always match with the location of OLT in this selected cohort. Our study results suggest that realignment procedures can improve symptoms and contribute to a decrease in size of the osteochondral lesion in patients who demonstrate a large cystic OLT of the talar shoulder and malalignment of the foot and ankle at the same time. Addressing malalignment primarily in such patients can potentially minimize the risk of morbidities or complications associated with procedures involving replacement surgery for the large cystic OLTs of the talar shoulder.

Lower Limb Alignment in Patients with Primary Valgus Ankle Arthritis: A Comparative Analysis with Patients with Varus Ankle Arthritis and Controls

Category: Ankle Arthritis; Ankle Introduction/Purpose: A comprehensive analysis of lower limb alignment may be a critical component of successful ankle joint preservation surgery. Although it is widely recognized that the combined effect of lower limb orientation and ankle and hindfoot alignment plays a fundamental role in ankle arthritis, supramalleolar/lower limb alignment has received less attention in valgus ankle arthritis. This study aims to analyze the lower limb alignment of patients with valgus ankle arthritis with primary origin, compared to those with varus ankle arthritis and normal controls. We hypothesize that patients with valgus ankle arthritis will exhibit the opposite pattern of lower limb alignment to those with varus ankle arthritis: valgus mechanical axis, valgus distal tibial plafond, and valgus hindfoot alignment. Methods: A retrospective radiographic analysis was conducted on 61 patients (62 ankles, mean age: 59.2 years) with valgus ankle arthritis with primary origin was performed. Preoperative weightbearing radiographs were used to measure seven radiographic parameters: Talar tilt angle, medial distal tibial angle (MDTA), talar center migration (TCM), anterior distal tibial angle (ADTA), talo-first metatarsal (Meary’s) angle, hindfoot moment arm (HMA), and mechanical axis deviation (MAD). For comparative radiographic analysis, a varus arthritis group with primary origin (n=55, mean age: 59.7 years) and a control group (n=58, mean age: 29.3 years) were included. Subgroup analyses of lower limb alignment were performed in the valgus arthritis group based on the MDTA (greater or less than 90 degrees, subgroup analysis 1) and Meary's angle (greater or less than -20 degrees, subgroup analysis 2). Results: The valgus group had a significantly lower mean MDTA than the control group (p &lt; 0.0001, Figure 1), indicating a varus distal tibial plafond in comparison to the control group. Meary's angle and HMA were significantly lower in the valgus group compared to the varus group (p &lt; 0.05 and p&lt; 0.0001, respectively). On whole limb radiographs, the valgus group showed a greater MAD than the control group (p &lt; 0.05), indicating a varus lower limb alignment. However, there was no significant difference in MAD between the valgus and varus groups (p=0.7031). Subgroup analysis 1 revealed that the MAD was varus- angulated regardless of the MDTA. Subgroup analysis 2 showed that both groups had comparable MDTA (p=0.8504); however, patients with a lower Meary’s angle had a significantly greater MAD. Conclusion: Our findings indicate that a significant proportion of ankles with primary valgus arthritis have a varus tibial plafond and a varus lower limb mechanical axis, which contradicts our current understanding. The similar lower limb and distal tibia orientation and different foot and hindfoot alignment between the valgus and varus group suggest that foot and hindfoot alignment may play an important role in the development of both types of arthritis. This study adds to our understanding of primary valgus ankle arthritis and suggests that lower limb alignment should be analyzed and considered throughout valgus ankle arthritis realignment procedures.

Comparing pinning in situ andcapital realignment procedures forsevere, stable slipped capital femoral epiphysis: a systematic review.

In severe, stable slipped capital femoral epiphysis, it is unclear whether pinning in situ (PIS) or capital realignment procedures (CRPs) are superior. Our primary aim was to compare patient-reported outcome measures (PROMs) following each strategy. Secondary aims were to compare rates of femoral head avascular necrosis (AVN) and complications. MEDLINE, Embase and Cochrane databases were searched according to an agreed strategy. Narrative review articles, case reports, letters to the editor and articles not written in English were excluded. The risk of bias was assessed using the Newcastle-Ottawa Scale. Of the 132 citations identified, 127 were excluded following de-duplication and application of the exclusion criteria. Three observational studies comparing PIS with CRP and two case series considering CRP alone were identified. One article was considered fair quality, and four articles were considered poor. In total, 198 hips from five studies were included (66 PIS, 132 CRP). PIS was associated with moderate-good functional outcomes, and CRP with good-high outcomes. Two comparative studies reported significantly better PROMs following CRP. AVN was reported in 1.5% following PIS and 10.6% following CRP. Regarding other complications, chondrolysis occurred in 3.0% following PIS and 2.4% following CRP. Femoroacetabular impingement rates were markedly higher following PIS (60.6% versus 2.3%). Reoperation rates were also greater following PIS (34.5% versus 13.3%). PIS tends to be associated with favourable AVN rates, but CRP with favourable PROMs and complication rates. However, comparisons were drawn from heterogeneous studies lacking long-term follow-up. Further high-quality research is required.

Derotational Hybrid Closed-Wedge High Tibial Osteotomy for Knee Osteoarthritis With Patellar Subluxation Caused by Tibial Torsional Deformity

Patellar subluxation and recurrent dislocation are commonly treated with medial patellofemoral ligament reconstruction, and patients with predisposing factors for these problems often require additional bony realignment procedures. However, these procedures mainly address problems in the axial plane, and patients with medial-compartmental knee osteoarthritis may require further realignment in the coronal plane. In this Technical Note article, we introduce our technique for derotational hybrid closed-wedge high tibial osteotomy. Using this technique, simultaneous 3-dimensional realignment in the axial, coronal, and sagittal planes can be achieved in patients with medial compartmental knee osteoarthritis and patellar subluxation caused by a tibial torsional deformity. The indications for the technique and the preoperative planning assessments involving a static torsional deformity analysis on computed tomography images and a dynamic gait analysis by our walking-on-paper method are presented. This is followed by a detailed description of the surgical procedure, together with consideration of the pearls and pitfalls of the procedure. A video of the surgery performed in a representative case with medial knee osteoarthritis and patellar subluxation in the right knee owing to an outward tibial torsion deformity is also provided.

Spatio-Temporal Coherence of mmWave/THz Channel Characteristics and Their Forecasting Using Video Frame Prediction Techniques

Channel state information in millimeter wave (mmWave) and terahertz (THz) communications systems is vital for various tasks ranging from planning the optimal locations of BSs to efficient beam tracking mechanisms to handover design. Due to the use of large-scale phased antenna arrays and high sensitivity to environmental geometry and materials, precise propagation models for these bands are obtained via ray-tracing modeling. However, the propagation conditions in mmWave/THz systems may theoretically change at very small distances, that is, 1 mm–1 μm, which requires extreme computational effort for modeling. In this paper, we first will assess the effective correlation distances in mmWave/THz systems for different outdoor scenarios, user mobility patterns, and line-of-sight (LoS) and non-LoS (nLoS) conditions. As the metrics of interest, we utilize the angle of arrival/departure (AoA/AoD) and path loss of the first few strongest rays. Then, to reduce the computational efforts required for the ray-tracing procedure, we propose a methodology for the extrapolation and interpolation of these metrics based on the convolutional long short-term memory (ConvLSTM) model. The proposed methodology is based on a special representation of the channel state information in a form suitable for state-of-the-art video enhancement machine learning (ML) techniques, which allows for the use of their powerful prediction capabilities. To assess the prediction performance of the ConvLSTM model, we utilize precision and recall as the main metrics of interest. Our numerical results demonstrate that the channel state correlation in AoA/AoD parameters is preserved up until approximately 0.3–0.6 m, which is 300–600 times larger than the wavelength at 300 GHz. The use of a ConvLSTM model allows us to accurately predict AoA and AoD angles up to the 0.6 m distance with AoA being characterized by a higher mean squared error (MSE). Our results can be utilized to speed up ray-tracing simulations by selecting the grid step size, resulting in the desired trade-off between modeling accuracy and computational time. Additionally, it can also be utilized to improve beam tracking in mmWave/THz systems via a selection of the time step between beam realignment procedures.

The Surgical Correction of Cavovarus Deformity in Charcot-Marie-Tooth Disease.

Charcot-Marie-Tooth (CMT) disease is the most commonly inherited neuropathy. CMT disease is a motor-sensory neuropathy with multiple genotypes. By comparison, the phenotypic expression is more uniform, with two main presentations. Most patients who need surgical care have progressive cavovarus foot deformity, with muscle imbalance causing a nonplantigrade foot, soft-tissue contractures, and abnormal bone morphology. Surgical treatment can be life-changing for these patients, allowing them to walk potentially brace free with more endurance and less pain. Early realignment procedures may reduce progression of joint arthritis. A minority of patients have diffuse paralysis below the knee. These patients are best treated with ground-reaction ankle-foot orthoses. This review article is based on the senior author's extensive experience with CMT, along with the limited evidenced-based literature.

Young Age and Concomitant or Prior Bony Realignment Procedures are Associated with Decreased Risk of Failure of Osteochondral Allograft Transplantation in the Knee: A Nationwide Database Study.

Osteochondral allograft (OCA) transplantation is a restorative surgical option for large, full-thickness chondral or osteochondral defects in the knee. Variability in outcomes reporting has led to a broad range of graft survival rates. Using rate of salvage surgery following OCA as a failure metric, the purpose of this study was to analyze the incidence and risk factors for failure in a nationwide cohort. The M151Ortho PearlDiver database was queried for patients aged 20 to 59 who underwent primary OCA between 2010 and 2020. Patients with prior cartilage procedures or arthroplasty were excluded. Kaplan-Meier survival analysis was performed to characterize cumulative rate of salvage surgery, defined as any patient subsequently undergoing revision OCA, autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), unicompartmental knee arthroplasty (UKA), or total knee arthroplasty (TKA). Multivariable logistic regression was used to determine the effect of several variables on odds of salvage surgery. Around 6,391 patients met inclusion criteria. Cumulative 5-year salvage rate was 1.71%, with 68.8% in the first 2 years. Age 20 to 29 and concomitant or prior bony realignment procedures were associated with significantly decreased rate of salvage surgery (age-adjusted odds ratio [aOR] = 0.49, 95% confidence interval [CI], 0.24-0.99, P = 0.046; realignment-aOR = 0.24, 95% CI, 0.04-0.75, P = 0.046). In the largest OCA cohort studied to date, less than 2% of patients required salvage surgery. Young age and bony realignment were protective. These findings suggest that OCA in the knee is a durable cartilage-restoration procedure, especially in young patients with corrected alignment.

Poster 269: 4-in-1 Quadricepsplasty for Habitual and Fixed Lateral Patellar Dislocation in Children

Poster 269: 4-in-1 Quadricepsplasty for Habitual and Fixed Lateral Patellar Dislocation in Children

Allograft Anterior Cruciate Ligament Reconstruction in Adolescent Patients May Result in Acceptable Graft Failure Rate in Nonpivoting Sports Athletes.

Studies have demonstrated that pediatric patients have an increased risk of failure with allograft anterior cruciate ligament reconstruction (ACLR); however, there is no study investigating whether allograft ACLR may be safe in older adolescent patients who are not returning to competitive pivoting sports (ie, low risk). The purpose of this study was to assess outcomes for low-risk older adolescents selected for allograft ACLR. We performed a retrospective chart review of patients younger than 18 years who received a bone-patellar-tendon-bone allograft or autograft ACLR by a single orthopaedic surgeon from 2012 to 2020. Patients were offered allograft ACLR if they did not intend to return to pivoting sports for 1 year. The autograft cohort was matched 1:1 based on age, sex, and follow-up. Patients were excluded for skeletal immaturity, multiligamentous injury, prior ipsilateral ACLR, or concomitant realignment procedure. Patients were contacted to obtain patient-reported outcomes at ≥2 years follow-up, including single assessment numerical evaluation, surgery satisfaction, pain scores, Tegner Activity Scale, and the Lysholm Knee Scoring Scale. Parametric and nonparametric tests were used as appropriate. Of the 68 allografts, 40 (59%) met inclusion and 28 (70%) were contacted. Among the 456 autografts, 40 (8.7%) were matched and 26 (65%) were contacted. Two allograft patients (2/40; 5%) failed at a median (interquartile range) follow-up of 36 (12, 60) months. There were 0/40 failures in the autograft cohort and 13/456 (2.9%) among the overall autografts; neither were significantly different from the allograft failure rate (both P > 0.05). Two (5.0%) patients in the autograft cohort required manipulation under anesthesia and arthroscopic lysis of adhesions. There were no significant differences between cohorts for single assessment numerical evaluation, Lysholm, Tegner, pain, and satisfaction scores (all P > 0.05). Although ACL allograft failure rates remain nearly two times higher than autograft failure rates in older adolescents, our study suggests that careful patient selection can potentially bring this failure rate down to an acceptable level. Level III; retrospective matched cohort study.

Effects of Lateral Opening-Wedge Distal Femoral Osteotomy on Meniscal Allograft Transplantation: A Biomechanical Evaluation

Background: Lateral meniscal deficiency with valgus malalignment increases the rate of lateral compartment osteoarthritis. Lateral meniscal allograft transplantation (LMAT) with a concomitant varus-producing opening-wedge distal femoral osteotomy (DFO) is an option yet to be evaluated biomechanically. Purpose/Hypothesis: The purpose of this study was to clarify the biomechanical effects of the realignment procedure in the setting of LMAT. We hypothesized that (1) given the dependence of the lateral compartment on the lateral meniscus, a DFO and increasing degrees of varus would be insufficient to restore lateral compartment pressures to normal from a lateral meniscus-deficient state, and that (2) LMAT would restore lateral compartment pressures to the intact state while DFO would decrease lateral compartment pressures for any given state of the meniscus. Study Design: Controlled laboratory study. Methods: Ten cadaveric knees underwent opening-wedge varus-producing DFO secured by an external fixator. Anatomic alignment was standardized to 6° of mechanical valgus, and each joint was tested in full extension. Submeniscal placement of thin film pressure sensors allowed for the recording of contact pressure, peak contact pressure, and contact area. The specimens were loaded on a biaxial dynamic testing machine with loading angles between 9° valgus and 6° varus of mechanical alignment. Conditions tested included intact meniscus, meniscal deficiency, and meniscal transplantation. Results: Isolated varus-producing DFO to 6° in the meniscus-deficient state failed to restore joint pressures and contact areas to the intact state, with significant changes in mean contact pressure (175%), mean peak contact pressure (135%), and contact area (–41%) (all P &lt; .05 vs intact), while LMAT restored all outcome measures (all P &gt; .05 compared with intact). After LMAT, every additional 1° of DFO correction contributed to a decrease in the mean contact pressure, peak pressure, and contact area of 5.6% (–0.0479 N/mm2), 5.9% (–0.154 N/mm2), and 1.4% (–6.99 mm2) for the lateral compartment and 7.3% (+0.034 N/mm2), 12.6% (+0.160 N/mm2), and 4.3% (+20.53 mm2) for the medial compartment, respectively. Conclusion: Isolated DFO was inadequate to restore load distribution in meniscus-deficient knees, while concomitant LMAT restored near normal forces and improved the lateral compartment biomechanical profile. Clinical Relevance Our findings support the concomitant use of LMAT and varus-producing DFO in the setting of lateral meniscal deficiency with valgus malalignment. This study provides tools for the orthopaedic surgeon to individualize the correction for each patient.