Incidence and risk factors for lateral hinge fractures in medial opening wedge high tibial osteotomy and medial opening wedge distal tibial tuberosity osteotomy.

BACKGROUND: The aims of this study were (1) to compare the incidence of lateral hinge fractures (LHFs) in medial opening-wedge high tibial osteotomy (OWHTO) and medial opening-wedge distal tibial tuberosity osteotomy (DTO), and (2) to investigate the risk factors for LHFs. The incidence of LHFs was hypothesized to be higher in the DTO group than the OWHTO group. The DTO procedure is also a risk factor for LHFs. METHODS: A total of 167 knees that underwent OWHTO (n = 65) and DTO (n = 102) were subjected to propensity score matching for the comparison of the groups. The matched variables were sex, preoperative hip-knee-ankle (HKA) angle, and preoperative medial proximal tibial angle. Forty-one matched pairs were enrolled for comparative analysis. Logistic regression analysis was performed to investigate risk factors for LHFs. RESULTS: The incidence of LHFs was not significantly different between the groups (34.1% vs. 26.8%, respectively; p = 0.631). Logistic regression analysis showed that age (odds ratio: 1.074, 95% confidence interval (CI): 1.020-1.131, p = 0.007), BMI (odds ratio: 1.150, 95% CI: 1.049-1.260, p = 0.003), and preoperative HKA angle (odds ratio: 1.150, 95% CI: 1.049-1.260, p = 0.035) were significant risk factors for LHFs. The difference in surgical technique between OWHTO and DTO was not a risk factor for LHFs (p = 0.204). CONCLUSIONS: The incidence of LHFs is similar in DTOs and OWHTOs, and the DTO procedure is not a risk factor for LHFs. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Can radiological findings detect neuropathic pain in patients with osteoarthritis of the knee undergoing surgery?

OBJECTIVES: The mechanism underlying neuropathic pain (NP) in osteoarthritis (OA) of the knee is not completely understood. This study aimed to investigate whether possible NP in patients with knee OA undergoing knee surgery is associated with specific radiological findings. METHODS: This study included 197 patients who underwent knee surgery for symptomatic knee OA. Clinical evaluation was performed using the Central Sensitization Inventory (CSI), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and PainDETECT questionnaire. Radiological evaluation was performed using the hip-knee-ankle (HKA) angle, posterior tibial slope (PTS), varus and valgus laxities, and magnetic resonance imaging OA Knee Score (MOAKS). Radiological findings were compared between patients with possible and unlikely NP. Logistic regression analysis was performed to identify the predictive factors for NP. RESULTS: There were 163 and 34 patients with unlikely NP and with possible NP, respectively. The percentage of patients with CSI score ≥ 40 was significantly higher in the possible NP group than in the unlikely NP group (17.6% vs. 6.1%). Patients with possible NP had worse WOMAC scores than patients with unlikely NP. There were no significant positive associations between the possible NP and radiological findings in knee OA. Regression analysis showed no predictive factors for possible NP. CONCLUSIONS: Possible NP is not associated with specific radiological findings in knee OA. Patients with possible NP may mediate CS and experience more severe symptoms, including decreased knee function and lower quality of life, than patients with unlikely NP.

Functional Impairment of Hip Joint and Activities of Daily Living Failure in Patients with Multiple Hereditary Exostoses.

Objective: In this study, we focused on the hip joints and examined pain and functional impairment, and their relationship with anatomical characteristics in MHE patients. Methods: Patients with MHE followed up in our hospital from January 2020 to December 2020 were enrolled. Clinical hip functional outcomes were evaluated using the Japanese Orthopedic Association (JOA) hip score and hip range of motion (ROM). Proximal femur geometric measurements were evaluated using radiography. Results: A total of 39 patients (78 hips) with a median age of 25.6 years and average JOA score of 94.0 ± 10.5 were included. Eight patients felt pain in their hip joints. The average ROM score was 18.2 ± 2.5, and 47.4% of the patients with MHE had ROM limitation. The average score of ability to walk was 19.6 ± 1.8, and three patients had some problems with walking. The average ADL score was 18.2 ± 2.5, and 51.3% of patients with MHE had some failures in ADL. The hip flexion and internal rotation were markedly restricted compared with the normal values. When patients were grouped according to their ADL scores, we found that the ADL failure group had a significantly lower ROM score than the no ADL failure group (p < 0.0001), and there were significant differences between the groups in terms of femoral neck widening (p = 0.0001). Conclusions: We found that half of MHE patients had some failures in their ADL due to hip functional impairment. The study results also suggest that femoral neck widening affected ADL failure and ROM limitation.

Thinner tuberosity osteotomy is more resistant to axial load in medial open-wedge distal tuberosity proximal tibial osteotomy: A biomechanical study.

BACKGROUND: The purpose of this study was to investigate axial load resistance of the tibia depending on the thickness of tibial tuberosity osteotomy in medial open-wedge distal tuberosity proximal tibial osteotomy (OWDTO). The hypothesis is that a thin tibial tuberosity osteotomy shows high axial load resistance of the tibia. METHODS: The OWDTO model was constructed from imitation bones of the tibia. Distal tibial tuberosity osteotomy was performed with thicknesses of 7, 14, and 21 mm (n = 5 for each group). Cyclic axial-load fatigue tests were performed to investigate the strain at five measurement points on the OWDTO model. An axial-load failure test was also performed to investigate the maximum strain for failure. RESULTS: The 7-mm OWDTO model showed a significantly lower stain range than the 14-mm model at the middle part of the lateral hinge (P = 0.0263, mean difference: -852.6 µÎµ), posterior part (P = 0.0465, mean difference: -1040.0 µÎµ), posterior tibial cortex (P < 0.0001, mean difference: -583.4 µÎµ), and plate (P = 0.0029, mean difference: -121.6 µÎµ). There were no significant differences in the strain at the tibial tuberosity between the groups. The axial load for complete failure was significantly higher in the 7-mm model than in the 21-mm model (P = 0.0010, mean difference: 2577.0 N). The failure points were at the lateral hinges. CONCLUSIONS: Thinner distal tibial tuberosity osteotomy is more resistant to axial load and may be recommended for the prevention of tibial and lateral hinge fractures after OWDTO.

Reduced dynamic loads due to hip dislocation induce acetabular cartilage degeneration by IL-6 and MMP3 via the STAT3/periostin/NF-κB axis.

Developmental dysplasia of the hip (DDH) is characterized by anatomical abnormalities of the hip joint, ranging from mild acetabular dysplasia to hip subluxation and eventually dislocation. The mechanism underlying the cartilage degeneration of the hip joints exposed to reduced dynamic loads due to hip dislocation remains unknown. We established a rodent hip dislocation (disarticulation; DA) model of DDH (DA-DDH rats and mice) by swaddling. Expression levels of periostin (Postn) and catabolic factors, such as interleukin-6 (IL-6) and matrix metalloproteinase 3 (Mmp3), increased and those of chondrogenic markers decreased in the acetabular cartilage of the DA-DDH models. Postn induced IL-6 and Mmp3 expression in chondrocytes through integrin αVß3, focal adhesion kinase, Src, and nuclear factor-κB (NF-κB) signaling. The microgravity environment created by a random positioning machine induced Postn expression in chondrocytes through signal transducer and activator of transcription 3 (STAT3) signaling. IL-6 stimulated Postn expression via STAT3 signaling. Furthermore, cartilage degeneration was suppressed in the acetabulum of Postn-/- DA-DDH mice compared with that in the acetabulum of wild type DA-DDH mice. In summary, reduced dynamic loads due to hip dislocation induced acetabular cartilage degeneration via IL-6 and MMP3 through STAT3/periostin/NF-κB signaling in the rodent DA-DDH models.

Relationship between histological changes of the anterior cruciate ligament and knee function in osteoarthritis patients.

BACKGROUND: The function of the anterior cruciate ligament (ACL) in osteoarthritis (OA) of the knee remains to be elucidated. The purpose of this study is to evaluate histological changes of the ACL in end-stage knee OA and to clarify the relationship between histological changes in the ACL and knee function. HYPOTHESIS: The hypothesis in this study was that ACL degeneration in knee OA is associated with decreased knee function. PATIENTS AND METHODS: Eighty-two ACL specimens from 65 patients who underwent primary total knee arthroplasty (TKA) were investigated. The correlation between histological changes of the ACL (myxoid changes, chondroid metaplasia, total collagen degeneration, microcyst formation, vascular proliferation, and inflammatory cell infiltration) and knee function (range of motion, anterior tibial translation test, knee extension muscle strength, one-leg standing time, and functional reach test) were investigated. Age, body mass index, joint space narrowing, osteophyte formation, lower extremity alignment, and knee medial/lateral instability were also evaluated. RESULTS: Myxoid change in the ACLs was significantly negatively correlated with one-leg standing time. Chondroid metaplasia was not correlated with knee function. Collagen degeneration in the ACL was significantly negatively correlated with knee flexion angle and one-leg standing time. In addition, a negative correlation between microcyst formation and knee flexion angle was noted. Osteophyte formation, particularly lateral femoral intercondylar osteophytes, was correlated with myxoid changes. The other parameters did not correlate with ACL histological changes. DISCUSSION: Myxoid changes in the ACL were shown to correlate with knee function. The osteophyte score, particularly as related to lateral femoral intercondylar osteophytes, correlated with the severity of myxoid changes in the ACL in knee OA. Precise ACL evaluation should be included in the indications for ACL-retaining surgeries because ACL degeneration may be related to decreased knee function after surgery. LEVEL OF EVIDENCE: IV, Diagnostic case series.

Extra-articular factors of the femur and tibia affecting knee balance in mechanically aligned total knee arthroplasty.

PURPOSE: Although the joint gap distance and compartment loading of the knee are different parameters for obtaining balanced knees in patients with total knee arthroplasty (TKA), the extent to which a balanced knee is achieved in patients with mechanically aligned TKA (MA-TKA) is unclear. This study aimed to investigate the anatomical factors that affect the ligament balancing in MA-TKA according to a gap balancing technique by measured resection technique. METHODS: The relationship between compartment loading, gap distance, and lower limb alignment was analysed in forty-three patients who underwent navigation-assisted MA-TKA with the minimum soft-tissue release. Radiographic parameters included hip-knee-ankle (HKA) angle, femorotibial angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle, posterior tibial slope, varus and valgus joint line convergence angle, femoral valgus angle, femoral shaft curve, and tibial shaft curve (TSC). RESULTS: The postoperative HKA angle was 0.4±1.5°, with one coronal alignment outlier (2.3%). The gap distance showed four unbalanced knees for extension (9.3%) and flexion (9.3%), whereas the compartment loading identified 17 unbalanced knees (39.5%) at extension, 8 (18.6%) at 45° flexion, 7 (16.2%) at 90° flexion, and 10 (23.2%) at full flexion in MA-TKA. Mediolateral differentials of compartment loading correlated with femoral valgus angle (0°, 45°, and 90° flexion), mLDFA (45° and 90° flexion), and TSC (45° and 90° flexion). Femoral valgus angle and TSC were risk factors of the mediolateral differentials of compartment loading. CONCLUSION: Extra-articular factors of femoral valgus angle, mLDFA, and TSC were associated with the mediolateral imbalance of compartmental loading, suggesting there is a limit to obtaining balanced knees in MA-TKA due to these unadjustable extra-articular factors. LEVEL OF EVIDENCE: IV, therapeutic case series.

Repair of Osteochondritis Dissecans of the Lateral Femoral Condyle by a Trochlea Osteochondral Autograft: A Case Report.

CASE: A 17-year-old adolescent boy with large deep osteochondritis dissecans (OCD) of the right lateral femoral condyle was treated with ipsilateral trochlea osteochondral autograft transplantation combined with iliac cancellous bone grafting to the donor site of the lateral trochlea. Both autografts were fused 3 months after surgery. It was radiographically confirmed that the OCD lesion was successfully reconstructed. CONCLUSION: This procedure is an alternative surgical option for large and deep OCDs. It offers sufficient loading strength to the joint and adequate reconstruction of the congruent joint surface and can be performed at any regular facility.

Medial proximal tibial angle at the posterior tibial plateau represents the pre-arthritic constitutional medial proximal tibial angle in anterior cruciate ligament-intact, advanced osteoarthritis of the knee.

PURPOSE: In kinematically aligned total knee arthroplasty (TKA), it is necessary to infer the pre-arthritic constitutional medial proximal tibial angle (MPTA) in advanced osteoarthritis (OA) of the knee with bone loss. The aim of this study was to investigate whether MPTA at the posterior tibial plateau represents the pre-arthritic constitutional MPTA in anterior cruciate ligament (ACL)-intact, advanced OA knees. It was hypothesized that MPTA at the posterior tibial plateau represents the pre-arthritic constitutional MPTA of ACL-intact, advanced knee OA. METHODS: One hundred varus, anterior cruciate ligament (ACL)-intact, advanced OA knees were analysed. The hip-knee-ankle (HKA) angle and MPTA were assessed on computed radiography (CR) and MPTAs at the anterior, middle, and posterior part of the tibial plateau were assessed on computed tomography (CT) images. The association between these parameters was also analysed. RESULTS: CR images showed an HKA angle of 172.4 ± 4.1° and MPTA of 84.3 ± 2.5°. CT images showed different MPTAs in the three regions, ranging from 83.9 ± 2.4° to 85.9 ± 2.8°. The middle MPTA was the lowest at 83.9 ± 2.4°. HKA angle correlated with the middle MPTA (r = 0.3355, 95% confidence interval [CI] 0.1489-0.4991, p = 0.0006) and ΔMPTA (Middle-Posterior) (r = 0.5128, 95% CI 0.3518-0.6443, p < 0.0001). CONCLUSION: The MPTA at the posterior tibial plateau represents the pre-arthritic constitutional MPTA in ACL-intact, advanced OA knees. LEVEL OF EVIDENCE: III, retrospective cohort study.

Destructive Arthropathy of the Interphalangeal Joint Following Revascularization After Degloving Hand Injury: A Case Report.

It is difficult to achieve satisfactory results in the treatment of advanced degloving injury, which is one of the most challenging injuries in hand surgery. In this report, we present a case of marked destructive arthropathy of the interphalangeal joint that developed following revascularization after degloving hand injury. A 37-year-old, right-handed female manual worker sustained a degloving injury of her fingers, including the dorsal hand. We performed revascularization and secondary surgery, which included tenolysis and a tendon graft, to obtain functional improvement. These 2 procedures provided significant improvement in the active range of motion of the respective fingers. However, the patient complained of postoperative pain in the proximal interphalangeal joint. X-ray revealed destructive changes in the interphalangeal joint, which advanced progressively. Destructive changes in the interphalangeal joint following advanced degloving injury should be recognized as a potential complication that could be a limitation of functional restoration. Follow-up X-ray examination is necessary, even in cases with no fracture of the phalanges at the time of injury. In the management of degloving injury, patients should be informed of the potential risk of destructive arthropathy, which could result in restricted motion with pain.

Fracture of the tibial tubercle does not affect clinical outcomes in medial opening wedge high tibial osteotomy with distal tibial tubercle osteotomy.

PURPOSE: To investigate whether tibial tubercle fracture affected clinical outcomes and bony union in medial opening wedge high tibial osteotomy with distal tibial tubercle osteotomy (DTO) and to determine the anatomical risk factors for tibial tubercle fracture. MATERIALS AND METHODS: All patients who underwent DTO were retrospectively reviewed, and 104 successive patients were included. The Knee Society Score and complications including tibial tubercle fracture were recorded. On radiographs and computed tomography scans, the length, thickness, width, height, and bony union of the osteotomized tibial tubercle and the posterior tibial slope were statistically analysed. RESULTS: Fracture of the tibial tubercle occurred intraoperatively in 11 patients (10.6%) and in the postoperative period in 1 (1.0%). The case of postoperative fracture showed non-union. There was no significant difference in the Knee Society Score between the non-fracture and fracture groups. There were significant differences in the posterior tibial slope and the height of the tibial tubercle between the groups (p < 0.0001 for each comparison). The logistic regression analysis showed that the height of the tibial tubercle was associated with a higher risk of the fracture of the tibial tubercle (p < 0.01; OR, 1.548; 95% CI, 1.149-2.085). However, there were no significant differences in the bony union rate of the tibial tubercle at 6 months after surgery between the groups. CONCLUSIONS: Tibial tubercle fracture did not affect the clinical outcome and bony union in spite of the relatively high occurrence rate. Anatomical risk factors for the fractures was a lower tibial tubercle position. LEVEL OF EVIDENCE: Level IV.

Preoperative prognostic factors associated with poor early recovery after trapeziectomy with ligament reconstruction and tendon interposition arthroplasty for thumb carpometacarpal osteoarthritis.

BACKGROUND: Trapeziectomy with ligament reconstruction and tendon interposition (LRTI) is performed for treating thumb carpometacarpal osteoarthritis. However, patients occasionally experience delayed postoperative recovery. Although several prognostic factors associated with long-term outcomes have been identified, the factors associated with delayed recovery after trapeziectomy with LRTI have not been identified. HYPOTHESIS: When we define major disability in the early postoperative period at 3 months after LRTI surgery as delayed recovery, some preoperative factors can influence with delayed recovery. Moreover, delayed recovery can influence the long-term therapeutic outcome. PATIENTS AND METHODS: Thirty thumbs that underwent trapeziectomy with LRTI (mean follow-up period, 29.3 months) were retrospectively analyzed. Major disability was defined by both DASH and Hand20 scores≥35 after surgery, and patients were divided into groups 1 (major disability; n=9) and 2 (no major disability; n=21) according to the scores at 3 months after surgery. Preoperative data, including age, sex, preoperative symptom duration, dominant hand surgery, concurrent surgery with LRTI, previous orthopedic surgery, employment, stage of osteoarthritis, thickness of the trapezium, metacarpophalangeal hyperextension deformity, DASH score, Hand20 score, visual analogue scale (VAS) scores for pain, grip strength, pinch strength, and range of motion of the thumb were compared between groups to identify the factors indicating a poor prognosis at 3 months after surgery. We also compared the clinical outcomes at the 12-month and final follow-up. RESULTS: Dominant hand surgery, previous orthopedic surgery, and preoperative poor DASH score were significantly more frequent in group 1, while the other factors did not show significant intergroup differences. Moreover, group 1 showed significantly poorer DASH score, grip and pinch strength, and active flexion of the thumb metacarpal joint at both the 12-month and final follow-up. This group also showed significantly poorer Hand20 and VAS scores at the final follow-up. DISCUSSION: Dominant hand surgery, previous orthopedic surgery, and preoperative poor DASH score were associated with poor recovery at 3 months after trapeziectomy with LRTI. Moreover, major disability at 3 months after surgery influenced poor clinical outcomes at the 12-month and final follow-ups. These data could be useful for counseling patients regarding the expected recovery duration and outcomes after LRTI surgery. LEVEL OF EVIDENCE: IV; retrospective therapeutic study.

Endothelial cell-specific reduction of heparan sulfate suppresses glioma growth in mice.

PURPOSE: Heparan sulfate (HS) is one of the factors that has been suggested to be associated with angiogenesis and invasion of glioblastoma (GBM), an aggressive and fast-growing brain tumor. However, it remains unclear how HS of endothelial cells is involved in angiogenesis in glioblastoma and its prognosis. Thus, we investigated the effect of endothelial cell HS on GBM development. METHODS: We generated endothelial cell-specific knockout of Ext1, a gene encoding a glycosyltransferase and essential for HS synthesis, and murine GL261 glioblastoma cells were orthotopically transplanted. Two weeks after transplantation, we examined the tumor progression and underlying mechanisms. RESULTS: The endothelial cell-specific Ext1 knockout (Ext1 CKO ) mice exhibited reduced HS expression specifically in the vascular endothelium of the brain capillaries compared with the control wild-type (WT) mice. GBM growth was significantly suppressed in Ext1 CKO mice compared with that in WT mice. After GBM transplantation, the survival rate was significantly higher in Ext1 CKO mice than in WT mice. We investigated how the effect of fibroblast growth factor 2 (FGF2), which is known as an angiogenesis-promoting factor, differs between Ext1 CKO and WT mice by using an in vivo Matrigel assay and demonstrated that endothelial cell-specific HS reduction attenuated the effect of FGF2 on angiogenesis. CONCLUSIONS: HS reduction in the vascular endothelium of the brain suppressed GBM growth and neovascularization in mice. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12672-021-00444-3.

Collateral Ligament Reconstruction of a Distal Interphalangeal Joint with Chronic Instability: A Case Report.

CASE: A 33-year-old man presented with a painful instability of the distal interphalangeal (DIP) joint of the little finger after recurrent sports-related traumatic injuries. Stress testing and radiography demonstrated the instability of the ulnar collateral ligament. We performed an ulnar collateral ligament reconstruction of the DIP joint using the palmaris longus tendon. One year after surgery, the patient reported a painless and stable DIP joint with good functional outcome. CONCLUSION: This procedure could be a viable treatment option for active, high-demand patients experiencing chronic symptomatic instability of the DIP joint because of a longstanding tear of the collateral ligament.

Osteochondral Peg Fixation for Chondral Fragment of the Knee in Adolescent Patients: A Report of Two Cases.

INTRODUCTION: Purely chondral injuries of the knee are relatively rare, and no consensus exists on the appropriate treatment in such cases. We describe two adolescent patients with chondral injury of the knee who were successfully treated by osteochondral peg fixation. Patients, Concerns, and Clinical Findings. In case 1, a 14-year-old boy presented with complaints of right knee pain after landing on his leg while playing basketball. Radiography and computerized tomography revealed no abnormalities. However, magnetic resonance imaging revealed a chondral defect in his lateral femoral condyle and a loose chondral fragment measuring 6.5 cm2. In case 2, a 12-year-old boy presented with complaints of left knee pain after a rotational injury while playing baseball. Similar to case 1, magnetic resonance imaging revealed a chondral defect in his lateral femoral condyle and a loose chondral fragment measuring 3.0 cm2. Primary Diagnosis, Interventions, and Outcomes. The two patients were treated by surgical fixation using osteochondral pegs, which were harvested from the femoral condyle. After a year, postoperative computerized tomography and magnetic resonance imaging showed union of the chondral fragment with the osteochondral pegs and surrounding tissue. In both cases, the Lysholm score was 100 points at the final follow-up more than 2 years after surgery. CONCLUSION: The findings reported herein suggest that osteochondral peg fixation is a feasible treatment option for chondral injury of the knee, with satisfactory outcomes.

Corrective Surgery for a Forearm Deformity in a Middle-Aged Patient with Multiple Hereditary Exostoses: A Case Report.

CASE: A 48-year-old man underwent corrective surgery for a deformity of the left forearm because of multiple hereditary exostoses (MHE). The patient had no complaint of pain, the appearance of his forearm improved, and acceptable range of motion of the wrist and forearm were maintained at 14-month follow-up. CONCLUSION: The esthetic forearm deformity in the middle-aged patient with MHE was successfully improved without sacrificing function. Although there is little evidence of forearm corrective surgeries for adult patients with MHE, this report could expand surgical indications for them.