Development of a clinical prediction rule for mobility status at discharge in patients with total knee arthroplasty: Using a decision tree model.

BACKGROUND: Total knee arthroplasty (TKA) is an effective treatment to improve mobility in patients with severe knee osteoarthritis. However, some patients continue to have poor mobility after surgery. The preoperative identification of patients with poor mobility after TKA allows for better treatment selection and appropriate goal setting. The purpose of this study was to develop a clinical prediction rule (CPR) to predict mobility after TKA. METHODS: This study included patients undergoing primary TKA. Predictors of outcome included patient characteristics, physical function, and psychological factors, which were measured preoperatively. The outcome measure was the Timed Up and Go test, which was measured at discharge. Patients with a score of ≥11 s were considered having a low-level of mobility. The classification and regression tree methodology of decision tree analysis was used for developing a CPR. RESULTS: Of the 101 cases (mean age, 72.2 years; 71.3 % female), 26 (25.7 %) were classified as low-mobility. Predictors were the modified Gait Efficacy Scale, age, knee pain on the operated side, knee extension range of motion on the non-operated side, and Somatic Focus, a subscale of the Tampa Scale for Kinesiophobia (short version). The model had a sensitivity of 50.0 %, a specificity of 98.7 %, a positive predictive value of 92.9 %, a positive likelihood ratio of 37.5, and an area under the receiver operating characteristic curve of 0.853. CONCLUSION: We have developed a CPR that, with some accuracy, predicts the mobility outcomes of patients after TKA. This CPR may be useful for predicting postoperative mobility and clinical goal setting.

Tendoscopic peroneal retinaculum repair for recurrent peroneal tendon dislocation enables earlier return to sports than the open procedure.

PURPOSE: The purpose of this study was to evaluate whether tendoscopic peroneal retinaculum repair for patients with recurrent peroneal tendon dislocation (RPTD) is more useful than an open procedure. METHODS: Twenty-five patients with RPTD were retrospectively reviewed. Twelve patients (13 ankles) with RPTD underwent the open procedure (Group A) between 2008 and 2014, and 13 patients (14 ankles) underwent the tendoscopic procedure (Group B) between 2014 and 2017. Evaluation parameters included clinical results [the Japanese Society for Surgery of the Foot (JSSF) ankle-hind foot scale], operation time, complications, return to sports, and recurrence. RESULTS: Postoperative JSSF ankle/hindfoot scale scores were significantly better than the pre-surgical scores in both groups. The mean operation time was significantly longer in Group B than in Group A (75.7 ± 20.5 vs 38.4 ± 10.5 min). There was one recurrence in Group A, but none in Group B. Group A had no complications, and Group B had one wound infection. Group B, excluding the case of infection, could return to sports earlier than Group A, excluding the recurrent case (13.4 ± 1.5 vs 12.2 ± 0.6 weeks). CONCLUSIONS: This tendoscopic procedure needs longer operation time and is more technically demanding, but it is a useful procedure, because it is less invasive and can accelerate return to sports. LEVEL OF EVIDENCE: III.

Does hallux valgus impair physical function?

BACKGROUND: The relationships between radiographic hallux valgus (HV) and various physical functions independent of knee osteoarthritis (KOA) were examined among residents of a mountain village in Japan. METHODS: Study participants were recruited from mountain village residents aged ≥50 years. Participants' height, weight, and body mass index (BMI) were measured, and baseline data, including age, sex, and foot pain, were obtained using interviews and questionnaires. Radiography of the feet and knees was performed to assess the presence of HV (HV angle ≥20°) and KOA (Kellgren-Lawrence grade ≥ II). Grip strength, 6-m walk at usual and maximum speeds, single-leg stance time, and stand up from a chair time were evaluated as physical function performance tests. Plantar pressure patterns were also examined. RESULTS: Moderate-severe HV (HV angle ≥30 degrees), impaired grip strength and maximum walking speed, and painful HV reduced usual and maximum walking speeds independent of KOA. Hallux plantar pressure decreased according to the HV angle. Hallux plantar pressure was significantly lower in painful HV than in the no HV feet or painless HV. CONCLUSIONS: Moderate-severe HV deformity and HV-related pain impaired physical function independent of KOA. By controlling the pain and severe deformity of HV by treatments such as surgery, the physical function of HV patients might be improved.

Prevalence of hallux valgus and risk factors among Japanese community dwellers.

BACKGROUND: To investigate the prevalence and severity of radiographically detected hallux valgus (HV) as well as associated risk factors among Japanese residents of Miyagawa, a mountain village located in the center of Mie Prefecture. METHODS: The height, weight and body mass index (BMI) of 403 participants (male n = 135, female n = 268) recruited from among the residents of Miyagawa Village, Japan aged ≥65 years were measured, and baseline data, including age, sex and medical history were obtained from interviews and questionnaires. Knee osteoarthritis (KOA) was determined from radiographs of the feet and knees, and osteoporosis was determined by measuring bone mineral density. Hallux valgus, defined as angulation of the big toe at the first metatarsophalangeal joint of >20°, was classified as: mild (20°-30°), moderate (30°-40°) or severe (>40°). Risk factors for HV were calculated using multivariate logistic regression analysis that included age, sex, obesity (BMI ≥25), KOA, osteoporosis, Heberden's nodes and low back pain as variables. RESULTS: The overall prevalence of definite radiographic HV was 22.8 % (184/806), and mild, moderate and severe HV was found in 66.3, 27.2 and 6.5 % of the participants, respectively. Hallux valgus was found in at least one foot in 120 (29.8 %) of the participants and the prevalence significantly differed between females with and without HV and KOA (odds ratios: 2.54 and 1.71, respectively). CONCLUSIONS: The prevalence of definite radiographic HV was 29.8 %. Female sex and KOA were significantly associated with increased risk for radiographic HV.

Soluble Neural-cadherin as a novel biomarker for malignant bone and soft tissue tumors.

BACKGROUND: Neural-cadherin (N-cadherin) is one of the most important molecules involved in tissue morphogenesis, wound healing, and the maintenance of tissue integrity. Recently, the cleavage of N-cadherin has become a focus of attention in the field of cancer biology. Cadherin and their ectodomain proteolytic shedding play important roles during cancer progression. The aims of this study are to investigate the serum soluble N-cadherin (sN-CAD) levels in patients with malignant bone and soft tissue tumors, and to evaluate the prognostic significance of the sN-CAD levels. METHODS: We examined the level of serum sN-CAD using an ELISA in 80 malignant bone and soft tissue tumors (bone sarcoma, n = 23; soft tissue sarcoma, n = 50; metastatic cancer, n = 7) and 87 normal controls. The mean age of the patients was 51 years (range, 10-85 years) and the mean follow-up period was 43 months (range, 1-115 months). RESULTS: The median serum sN-CAD level was 1,267 ng/ml (range, 135-2,860 ng/ml) in all patients. The mean serum sN-CAD level was 1,269 ng/ml (range, 360-2,860 ng/ml) in sarcoma patients, otherwise 1,246 ng/ml (range, 135-2,140 ng/ml) in cancer patients. The sN-CAD levels in patient were higher than those found in the controls, who had a median serum level of 108 ng/ml (range, 0-540 ng/ml). The patients with tumors larger than 5 cm had higher serum sN-CAD levels than the patients with tumors smaller than 5 cm. The histological grade in the patients with higher serum sN-CAD levels was higher than that in the patients with lower serum sN-CAD levels. A univariate analysis demonstrated that the patients with higher serum sN-CAD levels showed a worse disease-free survival rate, local recurrence-free survival rate, metastasis-free survival rate, and overall survival rate compared to those with lower serum sN-CAD levels. In the multivariate analysis, sN-CAD was an independent factor predicting disease-free survival. CONCLUSIONS: sN-CAD is a biomarker for malignant bone and soft tissue tumors, and a potentially valuable pre-therapeutic prognostic factor in patients with bone and soft tissue sarcoma.

Anatomic Features of Patients With Recurrent Peroneal Tendon Dislocation.

BACKGROUND: There are several anatomic variations of the peroneal muscles and lateral malleolus of the ankle that may play an important role in the onset of peroneal tendon dislocation. PURPOSE: To investigate the anatomic variations of the retromalleolar groove and peroneal muscles in patients with and without recurrent peroneal tendon dislocation using magnetic resonance imaging (MRI) and computed tomography (CT). STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 30 patients (30 ankles) with recurrent peroneal tendon dislocation who underwent both MRI and CT before surgery (PD group) and 30 age- and sex-matched patients (control [CN] group) who underwent MRI and CT were included in this study. The imaging was reviewed at the level of the tibial plafond (TP level) and at the center slice between the TP and the fibular tip (CS level). The appearance of a malleolar groove (convex, concave, or flat) and the posterior tilting angle of the fibula were assessed on CT images. The appearance of accessory peroneal muscles, height of the peroneus brevis muscle belly, and volume of the peroneal muscle and tendons were assessed on MRI scans. RESULTS: There were no differences in the appearance of the malleolar groove, posterior tilting angle of the fibula, or accessory peroneal muscles at the TP and CS levels between the PD and CN groups. The peroneal muscle ratio was significantly higher in the PD group than in the CN group at the TP and CS levels (both P < .001). The height of the peroneus brevis muscle belly was significantly lower in the PD group than in the CN group (P = .001). CONCLUSION: A low-lying muscle belly of the peroneus brevis and a larger muscle volume in the retromalleolar space were significantly associated with peroneal tendon dislocation. Retromalleolar bony morphology was not associated with peroneal tendon dislocation.

Knotless Tendoscopic Peroneal Retinaculum Repair Technique for Recurrent Peroneal Tendon Dislocation.

Peroneal tendon dislocation (PTD) is sometimes diagnosed as a sports-related injury, of which many cases lead to recurrent PTD (RPTD). Superior retinaculum repair is the major operative treatment of RPTD. The technique described herein comprises 8 steps: (1) Standard tendoscopic examination, (2) debridement of the pseudo-pouch base, (3) first anchor insertion, (4) suture relay, (5) second anchor insertion and suture relay, (6) third anchor insertion and suture relay, (7) suture tightening, and (8) suture bridge. Although this tendoscopic peroneal retinaculum repair technique is complicated, expensive, and requires a longer operation time, it incorporates a double-row suture bridge. Therefore, it has a wider contact surface between the superior retinaculum repair and fibula bone and tighter fixation than does a single-row technique. Moreover, our technique is knotless and thereby avoids knot-related complications. Tendoscopy has additional advantages in terms of less postoperative pain, fewer complications, and better cosmesis. In conclusion, this knotless tendoscopic peroneal retinaculum repair technique for RPTD is a patient-friendly surgery compared with previous procedures.

Repair of Acute Patellar Tendon Rupture Using an Internal Brace Technique.

Acute patellar tendon rupture is a serious injury, resulting in the disruption of the knee extensor mechanism. Many authors recommend augmented repairs of patellar tendon ruptures to allow early active rehabilitation. An internal brace technique, which is a ligament augmentation using high-strength suture tape and knotless anchors, has been used as augmentation for the primary tendon or ligament injury. A case of acute patellar tendon rupture in a Judo player, who was successfully treated with primary repair and augmentation using an internal brace technique, is presented. In this case, the patient regained full function of the knee and returned to full sports activities postoperatively. An internal brace technique provides biomechanical stability of the repaired tendon without donor site morbidity and could be an effective procedure for the treatment of acute patellar tendon rupture.

Arthroscopic Internal Brace Augmentation With Arthroscopic Modified Broström Operation for Chronic Ankle Instability.

Lateral ankle sprains are very common injuries that sometimes lead to chronic lateral ankle instability. The modified Broström operation is the gold standard procedure for treatment of chronic lateral ankle instability. Currently, this operation is performed arthroscopically. Broström repair depends on the quality of the remnant ligament. In cases with an insufficient remnant ligament, Gould augmentation or reconstruction using the gracilis tendon is generally performed. Recently, tape augmentation (internal brace) also has been used to support an insufficient ligament. This article introduces arthroscopic tape augmentation with arthroscopic modified Broström operation. This technique consists of creation of a talar anchor hole and fibular anchor hole, reattachment of the remnant ligament to the fibula with tape, and tape fixation to the talus. This technique uses only one knotless anchor screwed to the fibula for both the modified Broström operation and fixation of the tape. This technique is relatively simple and produces similar results as an open procedure.

The cleavage of N-cadherin is essential for chondrocyte differentiation.

The aggregation of chondroprogenitor mesenchymal cells into precartilage condensation represents one of the earliest events in chondrogenesis. N-cadherin is a key cell adhesion molecule implicated in chondrogenic differentiation. Recently, ADAM10-mediated cleavage of N-cadherin has been reported to play an important role in cell adhesion, migration, development and signaling. However, the significance of N-cadherin cleavage in chondrocyte differentiation has not been determined. In the present study, we found that the protein turnover of N-cadherin is accelerated during the early phase of chondrogenic differentiation in ATDC5 cells. Therefore, we generated the subclones of ATDC5 cells overexpressing wild-type N-cadherin, and two types of subclones overexpressing a cleavage-defective N-cadherin mutant, and examined the response of these cells to insulin stimulation. The ATDC5 cells overexpressing cleavage-defective mutants severely prevented the formation of cartilage aggregates, proteoglycan production and the induction of chondrocyte marker gene expression, such as type II collagen, aggrecan and type X collagen. These results suggested that the cleavage of N-cadherin is essential for chondrocyte differentiation.

Fibulin-3 negatively regulates chondrocyte differentiation.

Fibulin-3 is a member of the fibulin family that has been newly recognized as extracellular matrix proteins. We assessed the effects of fibulin-3 overexpression on chondrocyte differentiation using the clonal murine cell line ATDC5. The ATDC5-FBLN3 stably expressing fibulin-3 protein was spindle-shaped cell compared to the ATDC5-mock with plump cell. The cell growth in the ATDC5-FBLN3 was accelerated in comparison to that in the ATDC5-mock. The ATDC5-FBLN3 was not stained by Alcian blue, nor was there any cartilage aggregate formed after the induction of chondrogenic differentiation. The expression of type II collagen, aggrecan, and type X collagen was completely suppressed in ATDC5-FBLN3 even after the induction of differentiation. The overexpression of fibulin-3 reduced the expression of Sox5 and Sox6, while it maintained the expression of Sox9. These findings suggest that fibulin-3 may play an important role as a negative regulator of chondrocyte differentiation.

Spontaneous Osteonecrosis of the Tarsal Navicular: A Report of Two Cases.

Spontaneous osteonecrosis of the tarsal navicular, called the Mueller-Weiss syndrome, is an uncommon disease. Patients who are resistant to conservative treatment require operative treatment. However, there is no established operative treatment. Two cases of spontaneous osteonecrosis of the tarsal navicular with double (talonavicular and naviculocuneiform joints) arthrodeses with different locking plates are presented. Removal of necrotic areas from the tarsal navicular and replacement with autologous bone graft procured from the iliac crest followed by arthrodesis using a locking plate were performed. Case 1 was fixed with an LCP Distal Radius Plate (SYNTHES) and 6 2.4 mm locking screws. Case 2 was fixed with a Cervical Spine Locking Plate Variable Angle (SYNTHES) and 4 4.0 mm locking screws. Case 2 achieved solid fusion of the talonavicular-cuneiform joints, but case 1 resulted in nonunion of the talonavicular joint. This difference in internal fixation strength might have caused the difference in the results. Performance of double arthrodeses from the medial aspect using a locking plate is a reasonable operative procedure to treat spontaneous osteonecrosis of the tarsal navicular. Strong primary fixation using a thick plate with large-thread screws was important to obtain joint fusions.

A bizarre parosteal osteochondromatous proliferation at the sesamoid bone of the hallux: A case report.

A bizarre parosteal osteochondromatous proliferation (BPOP) is a rare, benign, osseous tumor that presents as an exophytic cortical growth consisting of bone, cartilage, and fibrous tissue. However, the identification of BPOP by preoperative imaging along with appropriate diagnosis and treatment without recurrence is challenging, particularly for BPOPs that rarely develop in certain parts of the body. Herein, we report a rare case involving a BPOP at the sesamoid bone of the hallux that was first suspected on preoperative computed tomography imaging. There has been no recurrence 3 years after surgical resection.

Endoscopic All-inside Repair of the Flexor Hallucis Longus Tendon in Posterior Ankle Impingement Patients.

Longitudinal flexor hallucis longus (FHL) tendon tears are sometimes complicated by posterior ankle impingement syndrome (PAIS), especially in ballet dancers. In recent years, PAIS has been treated endoscopically, but it is difficult to suture FHL tendon tears endoscopically. In this report, we describe how to suture the FHL tendon endoscopically with the Meniscal Viper Repair system (Arthrex, Naples, FL). Without our endoscopic technique, when a patient is found to have a longitudinal tear of the FHL under endoscopy, we must choose to either neglect the tear or convert to an open repair. Open tendon suture techniques have reportedly had relatively good results but require a longer skin incision than endoscopic surgery for PAIS. Compared with the open repair, the advantages of our technique include earlier recovery, less pain, a lower rate of soft tissue complications, and improved healing through better preservation of the blood supply. This technique is an attractive and useful option because it is an easy and safe method for longitudinal FHL tendon tears.

Extraskeletal myxoid chondrosarcoma arising from the clavicle.

This report presents an extremely rare case of extraskeletal myxoid chondrosarcoma (EMC) arising from the clavicular periosteum. To the best of our knowledge, this may be the first detailed report of its clinicopathological findings. The patient was a 48-year-old man. Plain radiography and CT did not demonstrate any osteolytic lesion or periosteal reaction in the right clavicle. However, MRI showed an isosignal-intensity mass on T1-weighted images and a homogeneous high signal intensity lesion on T2-weighted images. The histological findings of the widely resected tumor were consistent with the diagnosis of extraskeletal myxoid chondrosarcoma. Preoperative diagnosis of extraskeletal myxoid chondrosarcoma at an unusual location, as in this case, is difficult not only with imaging examinations alone, but sometimes even after histological examination of biopsy specimens.

Ultrasound Guidance in Performing a Tendoscopic Surgery to Treat Posterior Tibial Tendinitis: A Useful Tool?

A 25-year-old man with a pronation-external rotation type of fracture was surgically treated using a fibular plate. Five years later, he underwent resection of bone hyperplasia because of the ankle pain and limitation of range of motion. Thereafter, the left ankle became intermittently painful, which persisted for about one year. He presented at the age of 43 with persistent ankle pain. Physical and image analysis findings indicated a diagnosis of posttraumatic posterior tibial tendinitis, which we surgically treated using tendoscopy. Endoscopic findings showed tenosynovitis and fibrillation on the tendon surface. We cleaned and removed the synovium surrounding the tendon and deepened the posterior tibial tendon groove to allow sufficient space for the posterior tibial tendon. Full weight-bearing ambulation was permitted one day after surgery and he returned to his occupation in the construction industry six weeks after surgery. The medial aspect of the ankle was free of pain and symptoms at a review two years after surgery. Although tendoscopic surgery for stage 1 posterior tibial tendon dysfunction has been reported, tendoscopic surgery to treat posttraumatic posterior tibial tendinitis has not. Our experience with this patient showed that tendoscopic surgery is useful not only for stage 1 posterior tibial dysfunction, but also for posttraumatic posterior tibial tendinitis.

Tendoscopic Double-Row Suture Bridge Peroneal Retinaculum Repair for Recurrent Dislocation of Peroneal Tendons in the Ankle.

Traumatic dislocation of peroneal tendons in the ankle is an uncommon lesion that mainly affects young adults. Unfortunately, most cases lead to recurrent dislocation of the peroneal tendons of the ankle (RPTD). Therefore, most cases need operative treatment. One of the most common operative procedures is superior peroneal retinaculum (SPR) repair. Recently, surgery for RPTD has been achieved with less invasive arthroscopic procedures. In this article, tendoscopic surgery for RPTD using a double-row suture bridge technique is introduced. This technique consists of debridement of the lateral aspect of the fibula under an intrasheath pseudo-cavity, suture anchor insertion into the fibular ridge, and reattachment of the SPR to the fibula using a knotless anchor screwed into the lateral aspect of the fibula. This technique mimics the double-row suture bridge technique for rotator cuff tear repair. The double-row suture bridge technique requires more surgical steps than the single-row technique, but it provides a wider bone-SPR contact surface and tighter fixation than the single-row technique. This procedure is an attractive option because it is less invasive and has achieved results similar to open procedures.

Entrapment of Common Peroneal Nerve by Surgical Suture following Distal Biceps Femoris Tendon Repair.

We describe entrapment of the common peroneal nerve by a suture after surgical repair of the distal biceps femoris tendon. Complete rupture of the distal biceps femoris tendon of a 16-year-old male athlete was surgically repaired. Postoperative common peroneal nerve palsy was evident, but conservative treatment did not cause any neurological improvement. Reexploration revealed that the common peroneal nerve was entrapped by the surgical suture. Complete removal of the suture and external neurolysis significantly improved the palsy. The common peroneal nerve is prone to damage as a result of its close proximity to the biceps femoris tendon and it should be identified during surgical repair of a ruptured distal biceps femoris tendon.

Transverse Stress Fracture of the Proximal Patella: A Case Report.

Among stress fractures associated with sports activities, patellar stress fracture is rare. Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella. We describe an extremely rare case of transverse stress fracture of proximal patella in a 9-year-old athlete.A 9-year old boy, who participated in sports (sprints and Kendo) presented with left knee pain without any external injury. In plain radiographs, a fracture line was observed in the proximal 1/3 of the left patella, and a patella stress fracture was diagnosed. For treatment, because 7 months of conservative therapy showed no improvement, internal fixation was carried out using Acutrak screws, and bone union was thus achieved. Three months after the operation, he was able to return to his previous level of athletic sports activity.Regarding the mechanism of onset, it is believed that the causes are longitudinal traction force and patellofemoral contact pressure. On the other hand, the contact region of the patella with the femur changes with the flexion angle of the knee. In the current case, the fracture occurred at a site where the patella was in contact with the femur at a flexion angle of >90°, so it is believed that it occurred as a clinical condition from being subjected to repeated longitudinal traction force and patellofemoral contact pressure at a flexion angle of >90°, during the sports activities of sprints and Kendo. The nonunion of the transverse stress fracture of his proximal patella was successfully treated with internal fixation using Acutrak screws.

Double-Layered Lateral Meniscus Accompanied by Meniscocapsular Separation.

We report an extremely rare case of double-layered lateral meniscus accompanied by meniscocapsular separation. The upper accessory meniscus was connected with the posterior horn and middle segment of the lower normal meniscus and was more mobile than the lower normal meniscus. A meniscocapsular separation was evident at the overlapping middle segment. Clinical symptoms were significantly improved by the resection of the upper accessory meniscus and the repair of the meniscocapsular separation. Careful arthroscopic analysis of other associated pathologies together with this rare abnormality was needed to achieve clinical improvement.