Accuracy of Patient-Specific Instrument for Cylindrical Axis Implementation in Kinematically Aligned Total Knee Arthroplasty

Background@#In kinematically aligned total knee arthroplasty (KA-TKA), the cylindrical axis (CA) is very important in restoring the native joint line and kinematics of the pre-arthritic knee. This study aimed to determine the accuracy of patient-specific instrument (PSI) for restoring the CA for femoral bone resection in KA-TKA. @*Methods@#Thirty KA-TKAs were performed using a computed tomography (CT)-based PSI system. Data from preoperative CT were reconstructed into three-dimensional (3D) models using 3D-planning software. The CA was created by connecting the centers of each virtual sphere to the medial and lateral femoral condyles using computer software. Femoral bone resection of the distal and posterior condyles was performed parallel to the sagittal planes of the CA. The thickness of the CA-referenced bone resection was determined based on the thickness necessary for the respective regions of the femoral component. The PSI was manufactured to locate the guide pin for a conventional cutting block. The accuracy of PSI for KA-TKA was evaluated as the absolute error between the preoperatively predicted thickness and the intraoperative measurements in each of the four regions, as well as the difference in error between distal-medial (DM) and posterior-medial (PM) and between distal-lateral (DL) and posterior-lateral (PL). @*Results@#The differences in thickness of bone cut in the DM, DL, PM, and PL were 0.79 ± 0.39 mm (range, –1.20 to 1.50), 0.70 ± 0.42 mm (range, –1.50 to 1.50), 0.80 ± 0.46 mm (range, –0.80 to 1.50), and 0.75 ± 0.47 mm (range, –2.10 to 1.40), respectively. There was no significant difference in the thickness error between DM and PM (p = 0.959) and between DL and PL (p = 0.812). @*Conclusions@#In KA-TKA, PSI was effective for accurate femoral bone resection based on virtually planned thickness.

Kinematically Aligned Total Knee Arthroplasty with Patient-Specific Instrument

Kinematically aligned total knee arthroplasty (TKA) is a new alignment technique. Kinematic alignment corrects arthritic deformity to the patient's constitutional alignment in order to position the femoral and tibial components, as well as to restore the knee's natural tibial-femoral articular surface, alignment, and natural laxity. Kinematic knee motion moves around a single flexion-extension axis of the distal femur, passing through the center of cylindrically shaped posterior femoral condyles. Since it can be difficult to locate cylindrical axis with conventional instrument, patient-specific instrument (PSI) is used to align the kinematic axes. PSI was recently introduced as a new technology with the goal of improving the accuracy of operative technique, avoiding practical issues related to the complexity of navigation and robotic system, such as the costs and higher number of personnel required. There are several limitations to implement the kinematically aligned TKA with the implant for mechanical alignment. Therefore, it is important to design an implant with the optimal shape for restoring natural knee kinematics that might improve patient-reported satisfaction and function.

Is Full-Length Intramedullary Nail Necessary for Atypical Subtrochanteric Femoral Fracture Associated with Bisphosphonate?

Background@#American Society for Bone and Mineral Research recommend the use of intramedullary reconstruction of full length-nail for atypical subtrochanteric femoral fracture (ASFF). However, there is no study on the incidence of the ipsilateral femoral fracture after index operation of ASFF, and full-length nail has disadvantage as iatrogenic fracture and leg length discrepancy (LLD). The aim of this study was to investigate the incidence of ipsilateral secondary fracture after using partial-length nail, and to compare the outcomes on surgery of ASFF between partial length-nails and full length-nails. @*Methods@#Forty-five consecutive fractures with ASFFs which had undergone intramedullary fixation using cephalomedullary nail between 2011 and 2018 were enrolled. The 45 cases were grouped based on nail length into the partial-length nail group (n=26) and the full-length nail group (n=19). Ipsilateral secondary fracture, time to union, intra-operative iatrogenic fracture, metal failure, LLD, operative duration, and post-operative 24-hr blood loss were investigated. @*Results@#There was no ipsilateral secondary fracture after index operation. There were no statistically significant differences between the partial-length nail and full-length nail groups in the time to union, LLD, and post-operative 24-hr blood loss (P=0.427, 0.478, and 0.228, respectively). Operative duration showed statistically significant difference between 2 groups (P=0.034). Metal failure were occurred in 1 (3%) case of the partial-length nail group and 2 (10%) cases of the full-length nail group. Iatrogenic fractures during nail insertion occurred in 2 (7%) cases of the partial-length-nail group and 3 cases (15%) of the full-length nail group. @*Conclusions@#Although large scale studies are required, our study indicate that full-length nails are not usually required for the treatment of ASFF.

Atypical femoral neck fracture after prolonged bisphosphonate therapy

Of the drugs developed to prevent and treat osteoporosis, bisphosphonate has played a very important role in preventing osteoporotic fractures. However, case reports describing atypical femoral fractures in patients using long-term bisphosphonates have emerged. The majority of atypical femur fractures occurs in the lateral aspect of the subtrochanteric or femur diaphysis, which is explained by accumulation of tensile stress in these areas. Although the superior cortex of the femur neck withstands maximum tensile stress, to our knowledge, there have been only two reports (three cases) of atypical femoral neck fracture. In addition, none of those case reports revealed detailed pathology related to suppressed bone turnover rate. We encountered an incomplete femoral neck fracture and diagnosed it as “atypical” on the basis of the patient’s lack of trauma and medication history and pathological findings. For patients with groin pain, minimal or no trauma, and a history of long-term bisphosphonate use, an atypical femoral neck fracture should be considered.

Regional Distribution of Stress on the Distal Femur in Advanced Osteoarthritis

BACKGROUND: The aim of this study was to analyze regional differences in the stress distribution within the distal femur in advanced osteoarthritis (OA). METHODS: Distal femoral specimens with primary OA were obtained from 10 female donor cadavers (mean age, 65 years; range, 53–79). As controls, distal femurs without OA were obtained from 10 age- and sex-matched female cadavers (mean age, 67 years; range, 58–81). The articular surface of the distal femur was divided into anterior, middle, and posterior regions on each condyle. Mechanical properties and microstructure were assessed for each region with micro-computed tomography and finite element model analysis. RESULTS: The control group showed differences in stress distribution among 6 regions on the distal femur (P=0.037), but there was no regional difference in stress distribution among 6 regions on the distal femur in the advanced OA group (P=0.179). CONCLUSIONS: Regional stress distribution in the distal femur was different between advanced OA and normal groups. There were no regional differences in stress distribution in the advanced OA group. Altered loading patterns, bone remodeling, and chemical composition will affect stress distribution.

The Learning Curve for Biplane Medial Open Wedge High Tibial Osteotomy in 100 Consecutive Cases Assessed Using the Cumulative Summation Method

PURPOSE: The purpose of this study was to investigate whether surgical experience could improve surgical competency in medial open wedge high tibial osteotomy (MOWHTO). MATERIALS AND METHODS: One hundred consecutive cases of MOWHTO were performed with preoperative planning using the Miniaci method. Surgical errors were defined as under- or overcorrection, excessive posterior slope change, or the presence of a lateral hinge fracture. Each of these treatment failures was separately evaluated using the cumulative summation test for learning curve (LC-CUSUM). RESULTS: The LC-CUSUM showed competency in prevention of undercorrection, excessive posterior slope change, and lateral hinge fracture after 27, 47, and 42 procedures, respectively. However, the LC-CUSUM did not signal achievement of competency in prevention of overcorrection after 100 procedures. Furthermore, the failure rate for overcorrection showed an increasing tendency as surgical experience increased. CONCLUSIONS: Surgical experience may improve the surgeon’s competency in prevention of undercorrection, excessive posterior slope change, and lateral hinge fracture. However, it may not help reduce the incidence of overcorrection even after performance of 100 cases of MOWHTO over a period of 6 years.

Clinical Results of Complex Subtrochanteric Femoral Fractures with Long Cephalomedullary Hip Nail / 대한고관절학회지

PURPOSE: Good results of the cephalomedullary nails have been reported in proximal femoral fractures recently. Based on length of nails and shape of screws fixed in a femoral head for proximal fragment fixation, the proper nail length was in dispute. The purpose of this study was to evaluate the clinical and radiological results of a long cephalomedullary hip nail for the treatment of comminuted subtrochanteric femoral fractures. MATERIALS AND METHODS: Twenty-one consecutive patients with severe subtrochanteric femoral fractures who had undergone intramedullary fixation using long-PFNA II between March 2010 and March 2013 were followed-up for over 12 months. Their mean age was 64.8 years old (range, 43-85 years). Sixteen of 22 cases were high energy trauma. According to Seinsheimer's classification, 5 cases were type IV and 16 cases were type V. For radiological assessment, time to union, change of neck-shaft angle, sliding length, tip-apex distance (TAD) and leg length discrepancy (LLD) were measured. For clinical evaluation, a modified Koval index was investigated. RESULTS: Mean operation time was 96 minutes. An average decrease of neck-shaft angle was 4.5°. The average sliding length of the helical blade was 4.2 mm. Average LLD was 3.0 mm, and TAD was 23.0 mm. Mean modified Koval index score at final follow-up was 4.6 points. All the 21 subtrochanteric fractures healed uneventfully on an average of 24.2 weeks (range, 18-30 weeks). CONCLUSION: Long cephalomedullary hip nail provides excellent clinical and radiological outcomes in the comminuted subtrochanteric fracture.

The Efficacy of Low Molecular Weight Heparin for the Prevention of Venous Thromboembolism after Hip Fracture Surgery in Korean Patients

PURPOSE: The aim of this study was to investigate the efficacy of low-molecular-weight heparin (LMWH) for the prevention of venous thromboembolism in Korean patients who underwent hip fracture surgery (HFS). MATERIALS AND METHODS: Prospectively, a total 181 cases were classified into the LMWH user group (116 cases) and LMWH non-user group (65 cases). Each group was sub-classified according to fracture types as follows: 81 cases of intertrochanteric fracture (group A: 49, group B: 32) and 100 cases of neck fracture (group C: 67, group D: 33). We compared the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) according to LMWH use. RESULTS: Of the 181 cases, four DVTs were found in the LMWH user groups (1 in group A, and 3 in group C). One case of PE was found in LMWH non-user group D. The incidences of DVT and PE showed no statistically significant differences between the LMWH user and non-user groups (p=0.298 and 0.359, respectively). In subgroup analysis, no statistically significant differences were found between groups A and B and between groups C and D. CONCLUSION: The administration of LMWH was not effective in the prevention of venous thromboembolism and PE in the Korean patients who underwent HFS.

Comparison of the Chemical Composition of Subchondral Trabecular Bone of Medial Femoral Condyle between with Advanced Osteoarthritis and without Osteoarthritis

BACKGROUND: The purpose of this study is to investigate differences of chemical composition between subchondral bone in advanced osteoarthritic (OA) and non-OA distal femur. METHODS: Twenty femurs were harvested, respectively. The subchondral trabeculae were obtained from the middle of medial articular surface of distal femurs. A 10 mm diameter cylindrical saw was used to harvest. Raman spectroscopy, a non-destructive technique, was employed to determine the chemical information of the trabecular bones in the human distal femurs. RESULTS: The maximum intensity of the phosphate peak was 2,376.51+/-954.6 for the non-OA group and 1,936.3+/-831.75 for the OA group. The maximum intensity of the phosphate peak observed between the two groups was significantly different (P=0.017). The maximum intensity of the amide I peak were 474.17+/-253.42 for the nonOA group and 261.91+/-205.61 for the OA group. The maximum intensity of the amide I peak were significantly different between the two groups (P=0.042). Also, among other chemical and matrix components (Hydroxyproline,Carbonate, Amide IIIdisordered;ordered, and CH2), the spectrums showed similar significant differences in the intensity (P=0.027, P=0.014, P=0.012; P=0.038, P=0.029). Area integration were performed to determine disorder in collagen's secondary structure via amide III (alpha helix/random coil). The value of the alpha helix to random coil band area are significantly different (P=0.021) and result showing that there was a trend toward higher collagen maturity for the nonosteoarthritic bone specimens. CONCLUSIONS: The result suggested that OA may affect the chemical compositions of trabecular bone, and such distinctive chemical information may be.

Acute Rupture of Flexor Tendons as a Complication of Distal Radius Fracture / 대한정형외과학회잡지

Acute rupture of flexor tendons following distal radius fracture is very rare. We experienced four cases of acute rupture of flexor tendons that were treated surgically. Injured tendons included flexor pollicis longus, flexor carpi radialis, palmaris longus and third flexor digitorum profundus. A severely displaced fracture with a volar spike of the distal radius was detected on plain radiographs in all cases. Ruptures of flexor pollicis longus and third flexor digitorum profundus were diagnosed on preoperative examination but ruptures of other tendons were identified during the operation. Repairs of fractures and ruptured tendons were performed simultaneously and good functional outcomes were achieved.

Isolated Posterior Malleolar Fracture of Ankle Occurring with Total Knee Arthroplasty in Severe Osteoporotic Patient / 대한골다공증학회지

There are numerous reports of fractures associated with total knee arthroplasty. But, to our knowledge, isolated posterior malleolus fracture associated with TKR has not previously been reported. Here, we report a case of isolated posterior malleolar fracture that occurred with total knee arthroplasty. The patient was informed that data concerning the case would be submitted for publication.

Changes in Bone Mineral Density of Both Proximal Femurs after Total Knee Arthroplasty

BACKGROUND: This study investigated the effects of total knee arthroplasty (TKA) on bone mineral density (BMD) of the proximal femur in patients who underwent the procedure. METHODS: Forty-eight patients scheduled to undergo unilateral TKA because of primary knee osteoarthritis were included in this study, which was conducted at a medical center between October 2006 and October 2009. In these 48 patients, 96 hips were evaluated. Measurement of BMD was performed preoperatively and one month, three months, six months, and one year after unilateral TKA. Repeated measured analysis of variance and paired t-tests for comparison of two repeated samples were used to compare differences between time points (preoperation, one, three, six, and 12 months) and between the operative and nonoperative sides. RESULTS: Preoperatively, BMD of the femoral neck, trochanter, and total hip on the operative side were lower than on the nonoperative side; however, there was no statistical difference. BMD of both femoral neck areas was significantly lower than preoperative BMD at one month and three months after TKA. BMD of both trochanter areas was significantly lower than preoperative BMD at one month and three months after TKA. BMD of both total hips was significantly lower than preoperative BMD at three months after TKA. However, no statistical differences of changes in BMD were observed between the operative and nonoperative sides at each measurement time. CONCLUSIONS: According to our results, TKA was found to affect both proximal femurs during the acute period. However, TKA did not affect a change in BMD of the proximal femur during one year postoperative.

Focal Myositis around Hip Joint: 3 Cases Report / 대한고관절학회지

Focal myositis, a benign myositis which mostly occurs at lower extremity, is a disease that is spontaneously improved by conservative treatments such as bed rest and administration of nonsteroidal anti-inflammatory drug. Focal myositis is known to occur mostly at lower extremity, but we could not find a report of occurrence around hip. Therefore, authors attempt to report clinical progression along with the literature review.

The Effects of Timing of Tourniquet Release on Blood Loss in Navigation Assisted Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The aim of this study is to evaluate the effects of timing of tourniquet release on blood loss in navigation assisted total knee arthroplasty. MATERIALS AND METHODS: A total of 63 consecutive patients, who underwent navigation assisted total knee arthroplasty, were divided into two groups; 31 patients (31 knees, group I) were operated with tourniquet release after wound closure and applied compression dressing, and another 32 patients (32 knees, group II) were operated with tourniquet release and hemostasis before implantation of the polyethylene insert. We examined hemoglobin concentration and hematocrit at three points in time, preoperatively, 24 hours and 48 hours postoperatively. We compared the two groups of patients in terms of total blood loss, postoperative drained blood loss, hidden blood loss, visible blood loss and operation time. RESULTS: There were no significant differences between the two groups in the hemoglobin concentration at 24 hours and 48 hours postoperatively (p=0.371, p=0.247), and hematocrit at 24 hours and 48 hours postoperatively (p=0.428, p=0.125). No statistically significant differences between the two groups in the postoperative drained blood loss (p=0.381) and total blood loss (p=0.126) were found. We found statistically significant differences in the visible blood loss (p=0.023), hidden blood loss (p=0.045) and operation time (p=0.005). CONCLUSION: The releasing time of tourniquet have no effect on the actual total blood loss, and postoperative drained blood loss in navigation assisted total knee arthroplasty. We concluded that compared with intraoperative tourniquet release, postoperative tourniquet release are useful for making the broader operation field and less operation time.

The Incidence of Osteoporosis and the Related Factors Among Injured Sites in Above 50 Year-old Patients with Fractures Caused by Low-energy Trauma / 대한골다공증학회지

OBJECTIVES: To compare the incidence of osteoporosis and the related factors among fracture sites in above 50 year-old patients with fractures caused by low-energy trauma. MATERIALS AND METHODS: Seven hundred and fourteen patients with fracture from low energy trauma were evaluated retrospectively. By the Dual-energy x-ray absorptionmetry, we measured bone mineral density (BMD) at lumbar spine and proximal femur, and compared the incidence of osteoporosis, age, sex, body mass index (BMI), previous fracture history, past osteoporosis medication history according to each fracture sites. RESULTS: BMD was decreased according to increasing age with statistical significance (P<0.001). Sex has no significant difference according to fracture site (P=0.141). Average age of patients with osteoporotic fracture was 73.8, 72.8, 66.3, 73.4, 78.3 years old according to fracture site as T-spine, L-spine, distal radius, proximal humerus and proximal femur, respectively. There was significant difference among groups (P<0.001). Average BMI related with osteoporotic fracture site was 22.9 kg/m2, 22.7 kg/m2, 23.4 kg/m2, 23.0 kg/m2, 21.7 kg/m2, respectively and it showed significant difference among groups (P<0.001). Average bone mass and T-score related with osteoporotic fracture site was 0.587 g/cm2 (-3.5), 0.614 g/cm2 (-3.1), 0.647 g/cm2 (-2.6), 0.597 g/cm2 (-3.1), 0.554 g/cm2 (-3.5), with significant difference among groups (P<0.001). Previous fracture history had no significant difference among groups (P=0.078). Previous osteoporosis medication history had significant difference among the groups (P<0.001). CONCLUSIONS: In low-energy traumatic fracture, age, BMI and previous osteoporosis medication history are significantly related factors with BMD and osteoporotic fracture. Early diagnosis of osteoporosis and osteoporotic medication use is effective for decrease incidence of low-energy osteoporotic fracture.

Comparison of the Radiologic Outcomes following the Kinds of Implants in Treating Unstable Osteoporotic Intertrochanteric Fracture / 대한골다공증학회지

OBJECTIVES: To determine whether kinds of implants would influence on the radiologic outcomes in the treatment of unstable osteoporotic intertrochanteric fractures. MATERIALS AND METHODS: In this retrospective study, radiologic outcomes of 151 patients with unstable osteoporotic intertrochanteric fractures undergoing surgical treatments were compared based on the types of fixation implants as follows : PFNA (53 cases, group I), gamma nail 3(31 cases, group II), CHS with TSP (43 cases, group III), and helical blade type LCP-DHS with TSP (24 cases, group IV). On the follow-up radiographs after operations, we assessed differences of bone union durations, neck-shaft ankle changes, lag screw or helical blade slippages, and varus alpha angle changes among the study groups. RESULTS: All the radiologic outcomes evaluated in this study were not significantly different among the study groups. The average bone union durations of the group I, II, III and IV were 17.7, 18.0, 18.2, and 17.8 weeks, respectively (P=0.429). The average variation of neck-shaft angle of the group I, II, III and IV were 3.6degrees, 3.1degrees, 3.7degrees and 2.9degrees, respectively (P=0.273). The average lag screw or blade slippage of the group I, II, III and IV were 5.1 mm, 3.3 mm, 3.6 mm and 2.7 mm, respectively (P=0.154). The average variation of varus alpha of the group I, II, III and IV were 5.3degrees, 4.7degrees, 4.1degrees and 4.6masculine, respectively (P=0.894). CONCLUSIONS: This study indicates that four typical types of fixation implants for treating unstable osteoporotic intertrochanteric fractures would not lead to differences in postoperative radiological outcomes.

Changes in the Microstructural and Mechanical Properties in the Medial Condyle of Human Distal Femur in Advanced Osteoarthritis / 대한골다공증학회지

OBJECTIVES: The purpose of this study is to analyze and compare the micro-structural and mechanical properties of subchondral trabecular bone of non-osteoarthritic and osteoarthritic distal femur using micro-images based on finite element analysis. MATERIALS AND METHODS: Twenty distal femurs were harvested from 10 cadavers. The subchondral trabeculae were obtained from the middle of the articular surface of the medial femoral condyle of distal femurs. A total of 20 specimens were scanned using the micro-CT system. Micro-CT images were converted to micro-finite element model using the mesh technique, and micro-finite element analysis was then performed for assessment of the mechanical properties. RESULTS: According to the results, trabecular bone of osteoarthritic distal femur showed a decrease in trabecular thickness, bone volume fraction, structure model index, and yield stress and an increase in trabecular separation and structure model index. CONCLUSIONS: Results of bone morphometry index and strength showed greater deterioration of microstructure and decreased mechanical strength in subchondral trabeculae of the osteoarthritic group.

Acute Gluteal Compartment Syndrome without Gluteal Hematoma: A Case Report / 대한고관절학회지

Acute gluteal compartment syndrome (AGCS) is a rare condition associated with trauma, drug abuse, alcohol intoxication, prolonged immobilization, hip arthroplasty and epidural anesthesia. We report the case of a 42-year-old woman presenting severe buttock pain following decreased lower extremity motor function after an incident whereby she rolled down a flight of stairs. We performed fasciotomy of the gluteal fascia in order to provide relief from acute gluteal compartment syndrome. At the 2 month follow up visit her sensory and motor function had improved. Acute gluteal compartment syndrome is a rare condition which can result in misdiagnosis or delayed diagnosis. Careful consideration is needed for patients suffering severe buttock pain.

Acute Gluteal Compartment Syndrome without Gluteal Hematoma: A Case Report / 대한고관절학회지

Acute gluteal compartment syndrome (AGCS) is a rare condition associated with trauma, drug abuse, alcohol intoxication, prolonged immobilization, hip arthroplasty and epidural anesthesia. We report the case of a 42-year-old woman presenting severe buttock pain following decreased lower extremity motor function after an incident whereby she rolled down a flight of stairs. We performed fasciotomy of the gluteal fascia in order to provide relief from acute gluteal compartment syndrome. At the 2 month follow up visit her sensory and motor function had improved. Acute gluteal compartment syndrome is a rare condition which can result in misdiagnosis or delayed diagnosis. Careful consideration is needed for patients suffering severe buttock pain.

Result of Total Knee Arthroplasty in Pre-operative Adreanal Insufficiency Patients / 대한정형외과연구학회지

PURPOSE: The purpose of this study is to investigate to effect of adrenal insufficiency on the results of TKA. MATERIALS AND METHODS: A total of 89 patients (89 knees) treated with TKA from March, 2008 to October, 2008 were enrolled in this study. Levels of serum cortisol and adrenocorticotropic hormone (ACTH) were checked preoperatively. Hydrocortisone 50~75 mg was injected to adrenal insufficient group at 7:00 AM and 4:00 PM on operative day and the following day. We evaluated the range of motion, the knee society knee score and function score at preoperatively and 2 years follow up, and compared the results between non-adrenal insufficiency group (NAI) and adrenal insufficiency group (AI). RESULTS: Cortisol and ACTH levels were reduced in 36 of 89 patients. All of 36 patients of low cortisol level do not stimulated in ACTH stimulation test. In the adrenal insufficiency group the knee society score (KSS) improved from 49.8 to 86.8 and the knee society functional score (KSFS) from 42.6 to 89.5 at 2 years follow-up. In the control group KSS rose from 51.9 to 84.3 and KSFS from 49.4 to 88.6 during the same period. In adrenal insufficient patients, there were no postoperative complication to include mortality, infection, periprosthetic fracture except skin lesions during operation or postoperatively. There was a case of rupture of quadriceps tendon on the 10th postoperative day which was treated with primary repair. CONCLUSION: Based on our study, there was no increased operative and postoperative complications except skin lesions and 1 case quadricepse tendon rupture in patients with adrenal insufficiency group.