Return to Sports Activity After Microfracture for Osteochondral Lesion of the Talus in Skeletally Immature Children.

BACKGROUND: Osteochondral lesions of the talus (OLTs) are among the common sports-related injuries. However, there are few reports on the return to sports after OLT surgery in skeletally immature children. This study was performed to evaluate the return to sports after microfracture for OLTs in skeletally immature children. METHODS: This study involved 17 ankles of 16 patients (mean age, 13.2 years; range, 10-16 years) with open tibial epiphyses on magnetic resonance imaging (MRI) who underwent microfracture for OLTs <10 mm in diameter and confirmation of lesion instability under arthroscopy. Nine of 17 ankles had additional lateral ankle ligament stabilization. All patients were participating in some form of sports. The Japanese Society for Surgery of the Foot (JSSF) score, Ankle Activity Score (AAS), return to sports rate, lesion size, grade of subchondral bone marrow edema, and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score on MRI were evaluated after microfracture. The mean postoperative follow-up period was 53.5 months. RESULTS: The mean JSSF score significantly improved from 76.1 points preoperatively to 94.9 points at the final follow-up (P < .01). The mean AAS showed no change from preoperative state to final follow-up. The return to sports rate was 100%. The lesion size significantly decreased from 76.3 to 56.7 mm2 in area (P = .02) and from 283.2 to 185.6 mm3 in volume (P = .05). The bone marrow edema grade decreased in 8 of 17 ankles. The total MOCART score showed a significant improvement from 6 months to 1 year postoperatively (P = .05). CONCLUSION: All skeletally immature children who underwent microfracture for OLTs in this study were able to return to sports activity and showed improvements in clinical scores and MRI parameters. Microfracture may be considered an effective first-line treatment for OLTs <10 mm in diameter in skeletally immature athletes. LEVEL OF EVIDENCE: Level IV, retrospective case-control study.

Soft Tissue Stabilization of the Hinge Position for Lateral Closing-Wedge Distal Femoral Osteotomy: An Anatomic Study.

Background: Soft tissue plays an important role in stabilizing the hinge point for osteotomy around the knee. However, insufficient data are available on the anatomic features of the soft tissue around the hinge position for lateral closing-wedge distal femoral osteotomy (LCWDFO). Purpose: To (1) anatomically analyze the soft tissue around the hinge position for LCWDFO, (2) histologically analyze the soft tissue based on the anatomic analysis results, and (3) radiologically define the appropriate hinge point to prevent unstable hinge fracture based on the results of the anatomic and histological analyses. Study Design: Descriptive laboratory study. Methods: In 20 cadaveric knees (age, 82.7 ± 7.8 years; range, 60-96 years), the soft tissue of the distal medial side of the femur was anatomically analyzed. The thicknesses of the periosteum and direct insertion of the adductor tendon (AT) were histologically examined and measured using an electron microscope. The thickness of the periosteum was visualized graphically, and the graph of the periosteum and radiograph of the knee were overlaid using image editing software. The appropriate hinge position was determined based on the periosteal thickness and attachment of the AT. Results: The mean thickness of the periosteum of the metaphysis was 352.7 ± 58.6 µm (range, 213.6-503.4 µm). The overlaid graph and radiograph revealed that the thickness of the periosteum changed at the part corresponding to the transition between the diaphyseal and metaphyseal ends of the femur. The mean width of the AT attached to the distal medial femur from the adductor tubercle toward the distal direction was 7.9 ± 1.3 mm (range, 6.3-9.7 mm). Conclusion: Results indicated that the periosteum and AT support the hinge for LCWDFO within the area surrounded by the apex of the adductor tubercle and the upper border of the posterior part of the lateral femoral condyle. Clinical Relevance: When the hinge point is located within the area surrounded by the apex of the adductor tubercle and the upper border of the posterior part of the lateral femoral condyle, these soft tissues work as stabilizers, and there is no risk of cutting into the joint space.

Radiologic foot alignment and clinical outcome after percutaneous drilling for symptomatic accessory navicular in skeletally immature children.

Various surgical treatments are available for a symptomatic AN, including percutaneous drilling (PD). PD is reportedly effective for ANs in skeletally immature children. However, no reports have described the foot alignment after PD in skeletally immature children. This study was performed to compare the radiographic parameters between the preoperative period and the final follow-up after PD for symptomatic ANs in skeletally immature children. From October 2013 to December 2020, PD was performed on 13 feet in 10 skeletally immature children. The patients comprised 5 boys and 5 girls with a mean age at surgery of 11.9 years. The mean follow-up period was 14.8 months. We measured 5 radiographic findings preoperatively and at the final follow-up: calcaneal pitch angle (CPA), talocalcaneal angle (TCA), talonavicular coverage angle (TNCA), anteroposterior talo-first metatarsal angle (ATMA), and lateral talo-first metatarsal angle (LTMA). Ten feet were assessed as excellent, 1 as fair, and 2 as poor. Ten unions (76.9%) were achieved among the 13 feet. The mean CPA improved from 16.4 ±â€…4.1 degrees preoperatively to 18.2 ±â€…3.4 degrees at the final follow-up, the TCA improved from 43.0 ±â€…3.7 to 45.2 ±â€…4.4 degrees, and the TNCA improved from 19.9 ±â€…4.4 to 15.4 ±â€…5.0 degrees (P < .05). The ATMA and LTMA were not significantly different between the preoperative period and final follow-up. We found that PD for symptomatic ANs in skeletally immature children was effective treatment, and some radiographic parameters showed significant differences between the preoperative period and final follow-up.

Pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee.

BACKGROUND: In recent years, the involvement of the compensation ability of the subtalar joint in lower extremity alignment has been reported. We previously showed that hindfoot alignment angle (HAA) is an indicator of compensation ability of the subtalar joint. The abnormal compensation ability of the subtalar joint was defined by the mobility of the subtalar joint, and evaluation of the mobility of the subtalar joint may help to further clarify the pathophysiology of abnormal compensation ability of the subtalar joint. This study was performed to evaluate the mobility of the subtalar joint and clarify the pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee. METHODS: Seventy-two knees of 72 patients aged ≥40 years with varus knee were included in this study. Preoperative radiographs were used for measurement of this study parameters. Based on our previous study, we defined HAA of ≥15.9°as abnormal compensation ability of the subtalar joint. The patients were divided into an abnormal group (A-group) and normal group (N-group). All measurement parameters were compared between the groups, and correlations between the HAA and each measurement parameter were analyzed. RESULTS: The weight-bearing hindfoot angle (WBHA) (p < 0.001) and non-weight-bearing hindfoot angle (non-WBHA) (p = 0.003), were significantly greater in the A-group than in the N-group. Conversely, the ratio of change in hindfoot alignment (p = 0.006), were significantly smaller in the A-group than in the N-group. The HAA was positively correlated with WBHA (r = 0.66) and non-WBHA (r = 0.43) and negatively correlated with the ratio of change in hindfoot alignment (r = -0.32). CONCLUSIONS: The pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee is thought to involve a state of increased valgus of hindfoot alignment and an inability to move into normal hindfoot alignment. LEVEL OF EVIDENCE: Level Ⅲ, retrospective study.

Passive Ankle Plantarflexion Position and Skin Surface Blood Flow Adjacent to the Achilles Tendon.

BACKGROUND: Open repair of the Achilles tendon carries a risk of wound complications and infection. The Achilles tendon is covered by a thin layer of skin and subcutaneous tissue, which has a fragile blood supply. The full plantarflexion position may cause sustained blanching of the skin above the Achilles tendon. However, no reports have described the in vivo blood flow (BF) changes at the skin surface with ankle position. This study aimed to use laser Doppler flowmetry to evaluate the in vivo BF at the skin surface and thereby clarify the changes in BF with ankle position. METHODS: The study cohort comprised 30 feet in 15 participants with no history of Achilles tendon rupture. Laser Doppler flowmetry was used to measure the BF at the skin surface above the medial Achilles tendon in the natural plantarflexion (NP) and full plantarflexion (FP) positions. RESULTS: In the NP and FP positions, the BF at 5 cm proximal to the calcaneal insertion (frequent site of Achilles tendon rupture) was 1.50 ± 0.32 and 0.97 ± 0.28 mL/min/100 g, respectively (P < .0001). CONCLUSION: The BF at the skin surface adjacent to the medial Achilles tendon at 5 cm proximal to the calcaneal insertion was significantly less in the FP position than the NP position.

Effect of plantar fascia-specific stretching and Achilles tendon stretching on shear wave elasticity of the plantar fascia in healthy subjects.

BACKGROUND: The effect of stretching on the mechanical properties of the plantar fascia (PF) remain unclear. This study was performed to determine the effect of PF-specific stretching (PFSS) and Achilles tendon stretching (ATS) on the viscoelastic properties of the PF with shear wave elastography (SWE). METHODS: We recruited 14 participants (8 men, 6 women) with no history of PF disorders or painful episodes. The mean age of the participants was 30.9 ± 4.8 (range, 25-41) years. All participants performed sustained PFSS (sPFSS) on one foot and intermittent PFSS (iPFSS) on the other foot. Two weeks later, all participants performed sustained ATS (sATS) on one foot and intermittent ATS (iATS) on the other foot. SWE measurements were performed immediately after each stretching. RESULTS: The PF elasticity immediately before stretching ranged from 133.8 kPa to 144.7 kPa. The PF elasticity after stretching ranged from 158.9 kPa to 215.8 kPa. There was a significant increase in PF elasticity after sPFSS, iPFSS, sATS, and iATS (P < .01). The elasticity after sATS was greater than that after iATS (P = .03). In contrast, there were no differences in PF elasticity after stretching between sPFSS and iPFSS (P = .13), sPFSS and sATS (P = .17), or iPFSS and iATS (P = .50). CONCLUSIONS: PF elasticity increased after stretching regardless of the frequency and type of PFSS and ATS. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Femoral nerve status during the anterolateral approach for total hip arthroplasty: Motor-evoked potential analysis and an influencing factor.

BACKGROUND: Femoral nerve palsy is an uncommon but serious complication during the anterolateral approach for total hip arthroplasty. One of the reported reasons for femoral nerve palsy is retractor-induced intraoperative damage after retractor placement on the anterior wall of the acetabulum. The present study aimed to clarify the femoral nerve status during anterolateral approach total hip arthroplasty using motor-evoked potential analysis and to identify risk factors influencing the nerve status. METHODS: From June 2019 to September 2020, 32 hips in 31 patients underwent primary total hip arthroplasty via the anterolateral approach. The integrity of the femoral nerve was tested by the motor-evoked potential at three time points: preoperatively as a control (first period), immediately after retractor placement on the anterior wall of the acetabulum (second period), and after the procedure (third period). In the second period, the hips were divided into the following two groups: a <50% femoral nerve amplitude group and a ≥50% group. The iliopsoas muscle volume was evaluated by measuring the muscle cross-sectional area on preoperative computed tomography images, and compared between the two groups. RESULTS: The mean amplitude of the femoral nerve was significantly reduced from 100% in the first period to 35% in the second period (p < 0.01), but then significantly recovered to 54% in the third period (p < 0.01). In 26 (81%) hips, the femoral nerve amplitude was <50% in the second period. The muscle cross-sectional area of the iliopsoas muscle in the <50% group was significantly smaller than that in the ≥50% group (p < 0.05). CONCLUSIONS: The mean amplitude of the femoral nerve was significantly reduced to 35% in the second period, and the iliopsoas muscle volume was considered to influence this femoral nerve status.

Influence of hindfoot alignment on postoperative lower limb alignment in medial opening wedge high tibial osteotomy.

INTRODUCTION: We have experienced unexpected under-correction after medial opening wedge high tibial osteotomy (MOWHTO). Although the tibia was corrected accurately, the postoperative mechanical axis (MA) was less than 57%. The purpose of this study was to evaluate the relationship between hindfoot alignment and postoperative lower limb alignment, and to reveal whether hindfoot alignment affects lower limb alignment after MOWHTO. Our hypothesis was that hindfoot alignment influences the postoperative MA in MOWHTO. MATERIALS AND METHODS: This study was a retrospective comparative study. The study cohort comprised 43 knees in 43 patients who underwent MOWHTO and had standing long-leg anteroposterior view and hindfoot alignment view radiographs taken preoperatively and at 3 months postoperatively. To evaluate the hindfoot alignment, the absolute value of the ankle joint line orientation relative to the ground was added to the absolute value of the hindfoot angle. We defined a postoperative MA of 57-67% as acceptable correction (A group) and a MA of < 56% as under-correction (U group). The two groups were analyzed to identify factors that affected postoperative limb alignment. RESULTS: The preoperative hindfoot alignment angle was significantly larger in the U group than the A group. The preoperative hindfoot alignment angle was a significant predictive factor of the postoperative MA, and the cut-off value that distinguished under-correction from acceptable correction was 15.9 degrees. CONCLUSION: Abnormal hindfoot alignment is one of the causes of under-correction after MOWHTO. Attention should be paid to the preoperative ankle joint line orientation relative to the ground and hindfoot angle. If the preoperative hindfoot alignment angle is ≥ 15.9 degrees, surgeons should reconsider the operative procedure and correction angle. LEVEL OF EVIDENCE: Therapeutic level III, retrospective study.

Ankle bone morphology affects the size of non-trauma related osteochondral lesions of the talus in skeletally immature children.

BACKGROUND: This study aimed to elucidate the relationship between ankle morphology and the size of non-trauma related osteochondral lesions of the talus (OLT), because approximately half the OLT found in children is of unknown origin. METHODS: 34 ankles in 30 skeletally immature children with OLTs who underwent preoperative magnetic resonance imaging (MRI) were evaluated. Parameters measured included area of the OLT, tibial axis-medial malleolus angle (TMM), malleolar width (MalW), and talar surface angle (TSA; defined as the angle between the line perpendicular to the mid-diaphysis of the tibia and the talar joint surface; medial inclination, positive). The ankles were divided into two groups: the trauma group had a history of injury and the idiopathic group had no history of injury. The correlation between lesion area and MRI parameters were evaluated in each group. RESULTS: Thirteen ankles in 13 patients comprised the trauma group, while 21 ankles in 17 patients were in the idiopathic group. Of the 17 patients in the idiopathic group, four had bilateral OLT. In the trauma group, MalW was significantly correlated with the area (r = 0.827, P = 0.0001). In the idiopathic group, TMM and MalW were significantly correlated with the area (r = 0.608, P = 0.003 and r = 0.566, P = 0.008). TSA was positively correlated with area in the idiopathic group (r = 0.516, P = 0.017), but negatively correlated with area in the trauma group (r = -0.609, P = 0.027). The other parameters showed no significant correlation. CONCLUSIONS: The size of non-trauma related OLTs may have been affected by an ankle morphology showing poor bone conformity, such as an open medial malleolus and inclined talar joint surface. In addition, the evaluation of the contralateral ankle joint may be crucial when patients with OLT have no specific history of trauma.

Effect of the posterior sagging control device to the posterior tibial translation during posterior-stabilized total knee arthroplasty with modified gap technique.

PURPOSE: In modern total knee arthroplasty (TKA), flexion and extension gaps between the femur and tibia are equilibrated before implanting the final components. Uncontrolled intraoperative posterior tibial translation (PTT) could cause an artifactual widening of the flexion gap, which could lead surgeons to alter the femoral component size. We designed an intraoperative posterior sagging control device to prevent intraoperative PTT. In this study, we investigated whether the use of this device could prevent artifactual widening of the flexion gap. METHODS: Twenty-five patients, 21 women and four men, aged 74.2 years, were enrolled in this prospective study. All patients underwent postero-stabilized TKA using a navigation system. Intraoperative PTT, flexion and extension gaps with or without using the posterior sagging control device were measured with navigation system. These measurements were compared with or without the posterior sagging control device and after the final implantation also. RESULTS: There were significant differences between the measurements performed with or without the posterior sagging control device when compared to the post-implantation measurements. The use of the device reduced the number of patients with a >3 mm increase in flexion gap from 7 (28%) to 1 (4%). CONCLUSION: This study suggests that the posterior sagging control device prevents PTT and artificial flexion gap widening. This could prevent an unnecessary increase in component size.

Soft tissue stabilization of the hinge position in medial closed wedge distal femoral osteotomy: an anatomical study.

BACKGROUND: Soft tissue has an important role in stabilizing the hinge point of medial closed wedge distal femoral osteotomy (MCWDFO). However, there are conflicting data on the soft tissue anatomy around the hinge point of MCWDFO and, therefore, further anatomical data are needed. The purposes of the study were to: 1) anatomically analyze the soft tissue around the hinge point of MCWDFO; 2) radiologically define the appropriate hinge point to prevent an unstable hinge fracture based on the result of the anatomical analysis; and 3) histologically analyze the soft tissue based on the result of the anatomical analysis. METHODS: In 20 cadaveric knees, the capsule attachment of the distal lateral side of the femur was marked with a radiopaque ball bearing. A digital planning tool was used to calculate the area of the marked capsule attachment around the ideal hinge point of MCWDFO on radiographs. The soft tissue around the hinge point was histologically examined and the periosteal thickness was measured and visualized graphically. The graph and radiograph were overlayed using image editing software, and the appropriate hinge position was determined based on the periosteal thickness. RESULTS: As a result, the periosteal thickness of the distal lateral femur tended to rapidly decrease from the metaphyseal region toward the diaphyseal region. The overlayed graph and radiograph revealed that the periosteal thickness changed in the region corresponding to the apex of the turning point of the femoral metaphysis in all cases. CONCLUSIONS: In conclusion, the periosteum might support the hinge of MCWDFO within the area surrounded by the apex of the turning point of the femoral metaphysis and the upper border of the posterior part of the lateral femoral condyle.

Clinical outcomes of hybrid closed wedge high tibial osteotomy for advanced osteoarthritis of the knee compared with total knee arthroplasty.

PURPOSE: To evaluate clinical outcomes between hybrid closed wedge high tibial osteotomy (HCWHTO) and total knee arthroplasty (TKA) for advanced medial compartmental osteoarthritis of the knee (advanced knee OA). METHODS: In more than grade 3 OA based on the Kellgren-Lawrence classification, when patients' age was less than 60 years or activity level was more than level 5 based on the UCLA activity score, 22 knees (18 patients) underwent HCWHTO. The other 22 knees (18 patients) that underwent TKA were evaluated retrospectively. Muscle strength was evaluated preoperatively and at 1 year postoperatively. The visual analogue scale (VAS) and Japanese version of the Knee injury and Osteoarthritis Outcome Score (J-KOOS) were used to evaluate clinical outcomes preoperatively and at a mean 66-months follow-up. RESULTS: All postoperative muscle strength measures improved to preoperative equivalent levels in the HCWHTO group; they were significantly higher in the HCWHTO group than in the TKA group (p < .05). The VAS score and total J-KOOS significantly improved in both groups (HCWHTO, p = .001; TKA, p = .040); there were no significant differences in the scores between the groups at the final follow-up. Hybrid closed wedge HTO significantly improved the activities of daily living and sport/recreation scores, whereas TKA did not at the final follow-up. CONCLUSIONS: In advanced knee OA, HCWHTO led to improved muscle strength, and its midterm clinical outcomes were equivalent to those of TKA. To postpone or even to avoid TKA, HCWHTO is considered an appropriate treatment for young and high-activity patients with advanced knee OA. LEVEL OF EVIDENCE: Therapeutic Level III.

Changes in patellar baja progress until 3 months after medial open-wedge high tibial osteotomy.

PURPOSE: The purpose of this study was to evaluate sequential patellar height changes as well as the factors leading to these changes after medial open-wedge high tibial osteotomy (MOWHTO). METHODS: The study cohort constituted 37 knees from 36 patients who underwent MOWHTO for varus knee. The Caton-Deschamps index (CDI) for patellar height was measured preoperatively and at 2 weeks and 3, 6, and 12 months postoperatively. The factors related to sequential changes in patellar height were evaluated. RESULTS: Significant differences were observed between preoperative CDI and postoperative CDI at all time points (p < .05). Two-week postoperative CDI and postoperative CDI at 3,6,12-months was also significantly different (p < .05). The only significant factor for the change in patellar height between preoperative CDI and postoperative CDI at 2-weeks and 12-months was the change in the Δ medial proximal tibial angle (ΔMPTA) (postoperative MPTA-preoperative MPTA). We could not identify the factor that affected the change in patellar height change from 2-weeks postoperatively. CONCLUSION: The change in patellar height continued sequentially until at least 3 months postoperatively. ΔMPTA was associated with the change in patellar height at 2 weeks postoperatively compared with preoperatively; however, no factors associated with the change in patellar height from 2 weeks postoperatively to 3, 6, and 12-months postoperatively were identified.

Evaluation of the hindfoot alignment before and after total knee arthroplasty.

Background: Open wedge high tibial osteotomy (OWHTO) and total knee arthroplasty (TKA) alter the ankle joint line obliquity (AJLO) to be more horizontal relative to the ground and aligns the valgus subtalar joint (SJ) neutrally. A previous study of the hindfoot alignment angle (HAA) showed that lower limb alignment after OWHTO becomes under-corrected because of abnormal compensation by the SJ. However, because TKA can exclude effects of femorotibial joint instability, analysis of a post-TKA cohort enables a more accurate evaluation of SJ compensation than analysis of a post-OWHTO cohort. In the present study, we performed radiographic evaluations before and after TKA to analyze SJ compensation. Methods: Lower limb and hindfoot alignment were measured on plain radiographs in 46 patients (48 knees) who underwent TKA in our department. The patients were divided into Group A (postoperative AJLO within ±1°) and Group B (postoperative AJLO greater than ±1°), and various parameters were compared between the groups. The preoperative HAA that resulted in an abnormal postoperative AJLO was investigated. Results: Group A had a significantly smaller preoperative HAA (p = 0.03) and postoperative HAA (p < 0.01) than Group B. Differences in the preoperative HAA between the two groups showed a cut-off value of 9.06°. Conclusion: Patients with an HAA of more than 9.06° are likely to have abnormal hindfoot compensation.

Acute Anterior Dislocation in a Total Knee Arthroplasty Patient With a History of Sarcoma Resection.

Dislocation after total knee arthroplasty (TKA) is a rare complication, and few cases of anterior dislocation have been reported. Furthermore, there are no reports of early postoperative dislocation. A 72-year-old woman who had previously undergone resection of the posterior thigh muscle group for liposarcoma of the thigh underwent TKA for knee osteoarthritis. However, anterior dislocation was observed at 1 week postoperatively. We considered that the cause of the early anterior dislocation was previous resection of the posterior soft tissues of the knee joint. This case is a rare report of early anterior postoperative dislocation after TKA.

Femoral morphology affects postoperative alignment of the lower extremities in hybrid closed-wedge high tibial osteotomy.

INTRODUCTION: This study aimed to determine correction error predictors of lower extremitiy alignment after hybrid closed-wedge high tibial osteotomy (HCWHTO). MATERIALS AND METHODS: From 2011 to 2015, 102 knees in 75 patients with medial compartment knee osteoarthritis of the knee and varus knee deformities who underwent HCWHTO were evaluated in this retrospective study with a minimum 2-year follow-up. Preoperative radiological parameters including weight-bearing line ratio (WBL ratio), mechanical leg axis angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and JLCA under varus or valgus stress were measured. The knees were divided into the following three groups based on the WBL ratio on average 54 months after procedure: acceptable (WBL crossing the tibial plateau between 50 and 70%), under-correction (< 50%), and overcorrection (> 70%). A multiple regression analysis was performed to evaluate predictors that could influence postoperative WBL ratio and cut-off values of predictive preoperative factors was analysed. RESULTS: Significant differences in pre- and postoperative WBL ratios and mechanical leg axis angles were found. Preoperative mLDFA in the under-correction group (89.4° ± 2.1°) was significantly higher than that in the overcorrection group (87.4° ± 2.2°) (p = 0.015), while other preoperative parameters revealed no significant differences. The postoperative MPTA in the under-correction group (92.1° ± 3.7°) was significantly lower than that in the other two groups (p = 0.005 and p = 0.0001, respectively), while there was no significant change between the acceptable (94.6° ± 3.4°) and the overcorrection (96.7° ± 3.2°) groups. Multiple regression analysis revealed that mLDFA (ß = - 0.316; p = 0.010) had a significant impact on postoperative WBLR. The cut-off value for under-correction of mLDFA was 89.5°and sensitivity and specificity were 53.6 and 71.6%, respectively (p = 0.014). CONCLUSIONS: Preoperative mLDFA is significantly associated with postoperative alignment in HCWHTO. While postoperative MPTA is important, disregarding the preoperative mLDFA may bears a high risk of malcorrection. Varus alignment of the knee with larger mLDFA may be an indication for not only HCWHTO, but also for distal femoral osteotomy.

Risk factors for recurrence of hallux valgus deformity after minimally invasive distal linear metatarsal osteotomy.

BACKGROUND: Recurrence of hallux valgus deformity is a complication following surgical treatment of hallux valgus. This study was performed to identify risk factors for recurrence of hallux valgus deformity after minimally invasive distal linear metatarsal osteotomy (DLMO). METHODS: Sixty-seven patients (100 feet) with mild to severe hallux valgus who underwent DLMO from 2007 to 2018 were retrospectively investigated. Their average age at the time of surgery was 54 years (range, 18-88 years). The average follow-up duration was 46 months. The feet were divided into two groups: with and without recurrence. A multivariate analysis was performed to identify the risk factors for recurrence of deformity based on preoperative and 3-month postoperative radiographic parameters. RESULTS: Recurrence of deformity was found in 18 (18%) of the 100 feet at the final follow-up. The preoperative hallux valgus angle and 3-month postoperative hallux valgus angle, intermetatarsal angle, round sign positivity, and sesamoid position grade were significantly greater in the recurrence group than in the non-recurrence group. The logistic regression analysis revealed that a 3-month postoperative hallux valgus angle of ≥13.5°, positive round sign, and grade ≥2 sesamoid position were significantly associated with recurrence of deformity. CONCLUSIONS: The present findings can help to identify patients at higher risk of recurrence of hallux valgus deformity after DLMO and to modify their surgical procedures.

Straight Form of Calcaneofibular Ligament as a Three-Dimensional Magnetic Resonance Imaging Sign in Diagnosis of Calcaneofibular Ligament and Anterior Talofibular Ligament Inferior Fascicle Injury.

The present study was performed to investigate the morphological characteristics of the calcaneofibular ligament (CFL) and evaluate its relationship to the anterior talofibular ligament (ATFL) in patients with lateral ankle ligament injury using 3-dimensional magnetic resonance imaging (3D-MRI). This retrospective study involved 35 patients with lateral ankle ligament injury and 24 patients without a history of ankle trauma and a bone abnormality as controls. Reconstructed 3D-MRI was used to classify the form of the CFL as curved, wavy, or straight. The presence/absence of continuity between the fibula and CFL was evaluated in the 35 patients with injury, who were divided into 2 groups (continuity and discontinuity groups). The number of fascicles in the ATFL and the continuity between the distal end of the fibula and the proximal end of the ATFL were then evaluated. Among the patients with injury, 54.3% had the curve type of CFL, 34.3% had the wave type, and 11.4% had the straight type. In the control group, 62.5% had the curve type, 37.5% had the wave type, and none had the straight type. Continuity between the fibula and CFL was seen in 88.6%, and discontinuity was seen in 11.4%. Additionally, 85.7% had double fascicles in the ATFL. Inferior fascicle discontinuity between the ATFL and fibula was found in 13.3% with a double-fascicle ATFL; in all of these patients, the form of the CFL was straight and exhibited inferior fascicle discontinuity. The straight form of CFL could be a 3D-MRI sign in the diagnosis of CFL and ATFL inferior fascicle injury.

Reliability of various diastasis measurement methods on weightbearing radiographs in patients with subtle Lisfranc injuries.

OBJECTIVE: This study aimed to evaluate the reliability of the diastasis measurements between the medial cuneiform and the second metatarsal on weightbearing radiography. MATERIALS AND METHODS: We retrospectively examined 18 patients who underwent open surgery for subtle Lisfranc injuries. Preoperative weightbearing radiography of the affected and unaffected feet was evaluated in all patients. The diastasis between the medial cuneiform and the second metatarsal was measured in both feet using the following four methods: diastasis between parallel lines, distal point diastasis, middle point diastasis, and proximal point diastasis. Intraclass correlation coefficients with consistency of agreement were calculated to evaluate inter- and intraobserver reliability. RESULTS: The intra- and interobserver reliabilities of all four methods were good. Intraclass correlation coefficients for intraobserver reliability ranged from 0.87 to 0.93. Those for interobserver reliability ranged from 0.81 to 0.91. CONCLUSIONS: The reliabilities of the diastasis measurement methods between the medial cuneiform and the second metatarsal on weightbearing radiography were good. Measuring the diastasis between the medial cuneiform and the second metatarsal on weightbearing radiography is useful in evaluating subtle injuries when uniform measurement methods are used.